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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 3 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2022, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Checks; use Checks;
with Contracts; use Contracts;
with Debug; use Debug;
with Elists; use Elists;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Errout; use Errout;
with Eval_Fat; use Eval_Fat;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch9; use Exp_Ch9;
with Exp_Disp; use Exp_Disp;
with Exp_Dist; use Exp_Dist;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Expander; use Expander;
with Freeze; use Freeze;
with Ghost; use Ghost;
with Itypes; use Itypes;
with Layout; use Layout;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Case; use Sem_Case;
with Sem_Cat; use Sem_Cat;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch10; use Sem_Ch10;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Elab; use Sem_Elab;
with Sem_Elim; use Sem_Elim;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Res; use Sem_Res;
with Sem_Smem; use Sem_Smem;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Sinput; use Sinput;
with Snames; use Snames;
with Strub; use Strub;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
with Warnsw; use Warnsw;
package body Sem_Ch3 is
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
-- Ada 2005 (AI-251): Add the tag components corresponding to all the
-- abstract interface types implemented by a record type or a derived
-- record type.
procedure Build_Access_Subprogram_Wrapper (Decl : Node_Id);
-- When an access-to-subprogram type has pre/postconditions, we build a
-- subprogram that includes these contracts and is invoked by an indirect
-- call through the corresponding access type.
procedure Build_Derived_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True);
-- Create and decorate a Derived_Type given the Parent_Type entity. N is
-- the N_Full_Type_Declaration node containing the derived type definition.
-- Parent_Type is the entity for the parent type in the derived type
-- definition and Derived_Type the actual derived type. Is_Completion must
-- be set to False if Derived_Type is the N_Defining_Identifier node in N
-- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the
-- completion of a private type declaration. If Is_Completion is set to
-- True, N is the completion of a private type declaration and Derived_Type
-- is different from the defining identifier inside N (i.e. Derived_Type /=
-- Defining_Identifier (N)). Derive_Subps indicates whether the parent
-- subprograms should be derived. The only case where this parameter is
-- False is when Build_Derived_Type is recursively called to process an
-- implicit derived full type for a type derived from a private type (in
-- that case the subprograms must only be derived for the private view of
-- the type).
--
-- ??? These flags need a bit of re-examination and re-documentation:
-- ??? are they both necessary (both seem related to the recursion)?
procedure Build_Derived_Access_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived access type,
-- create an implicit base if the parent type is constrained or if the
-- subtype indication has a constraint.
procedure Build_Derived_Array_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived array type,
-- create an implicit base if the parent type is constrained or if the
-- subtype indication has a constraint.
procedure Build_Derived_Concurrent_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived task or
-- protected type, inherit entries and protected subprograms, check
-- legality of discriminant constraints if any.
procedure Build_Derived_Enumeration_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
-- type, we must create a new list of literals. Types derived from
-- Character and [Wide_]Wide_Character are special-cased.
procedure Build_Derived_Numeric_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For numeric types, create
-- an anonymous base type, and propagate constraint to subtype if needed.
procedure Build_Derived_Private_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True);
-- Subsidiary procedure to Build_Derived_Type. This procedure is complex
-- because the parent may or may not have a completion, and the derivation
-- may itself be a completion.
procedure Build_Derived_Record_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Derive_Subps : Boolean := True);
-- Subsidiary procedure used for tagged and untagged record types
-- by Build_Derived_Type and Analyze_Private_Extension_Declaration.
-- All parameters are as in Build_Derived_Type except that N, in
-- addition to being an N_Full_Type_Declaration node, can also be an
-- N_Private_Extension_Declaration node. See the definition of this routine
-- for much more info. Derive_Subps indicates whether subprograms should be
-- derived from the parent type. The only case where Derive_Subps is False
-- is for an implicit derived full type for a type derived from a private
-- type (see Build_Derived_Type).
procedure Build_Discriminal (Discrim : Entity_Id);
-- Create the discriminal corresponding to discriminant Discrim, that is
-- the parameter corresponding to Discrim to be used in initialization
-- procedures for the type where Discrim is a discriminant. Discriminals
-- are not used during semantic analysis, and are not fully defined
-- entities until expansion. Thus they are not given a scope until
-- initialization procedures are built.
function Build_Discriminant_Constraints
(T : Entity_Id;
Def : Node_Id;
Derived_Def : Boolean := False) return Elist_Id;
-- Validate discriminant constraints and return the list of the constraints
-- in order of discriminant declarations, where T is the discriminated
-- unconstrained type. Def is the N_Subtype_Indication node where the
-- discriminants constraints for T are specified. Derived_Def is True
-- when building the discriminant constraints in a derived type definition
-- of the form "type D (...) is new T (xxx)". In this case T is the parent
-- type and Def is the constraint "(xxx)" on T and this routine sets the
-- Corresponding_Discriminant field of the discriminants in the derived
-- type D to point to the corresponding discriminants in the parent type T.
procedure Build_Discriminated_Subtype
(T : Entity_Id;
Def_Id : Entity_Id;
Elist : Elist_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False);
-- Subsidiary procedure to Constrain_Discriminated_Type and to
-- Process_Incomplete_Dependents. Given
--
-- T (a possibly discriminated base type)
-- Def_Id (a very partially built subtype for T),
--
-- the call completes Def_Id to be the appropriate E_*_Subtype.
--
-- The Elist is the list of discriminant constraints if any (it is set
-- to No_Elist if T is not a discriminated type, and to an empty list if
-- T has discriminants but there are no discriminant constraints). The
-- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
-- The For_Access says whether or not this subtype is really constraining
-- an access type.
function Build_Scalar_Bound
(Bound : Node_Id;
Par_T : Entity_Id;
Der_T : Entity_Id) return Node_Id;
-- The bounds of a derived scalar type are conversions of the bounds of
-- the parent type. Optimize the representation if the bounds are literals.
-- Needs a more complete spec--what are the parameters exactly, and what
-- exactly is the returned value, and how is Bound affected???
procedure Check_Access_Discriminant_Requires_Limited
(D : Node_Id;
Loc : Node_Id);
-- Check the restriction that the type to which an access discriminant
-- belongs must be a concurrent type or a descendant of a type with
-- the reserved word 'limited' in its declaration.
procedure Check_Anonymous_Access_Component
(Typ_Decl : Node_Id;
Typ : Entity_Id;
Prev : Entity_Id;
Comp_Def : Node_Id;
Access_Def : Node_Id);
-- Ada 2005 AI-382: an access component in a record definition can refer to
-- the enclosing record, in which case it denotes the type itself, and not
-- the current instance of the type. We create an anonymous access type for
-- the component, and flag it as an access to a component, so accessibility
-- checks are properly performed on it. The declaration of the access type
-- is placed ahead of that of the record to prevent order-of-elaboration
-- circularity issues in Gigi. We create an incomplete type for the record
-- declaration, which is the designated type of the anonymous access.
procedure Check_Anonymous_Access_Components
(Typ_Decl : Node_Id;
Typ : Entity_Id;
Prev : Entity_Id;
Comp_List : Node_Id);
-- Call Check_Anonymous_Access_Component on Comp_List
procedure Check_Constraining_Discriminant (New_Disc, Old_Disc : Entity_Id);
-- Check that, if a new discriminant is used in a constraint defining the
-- parent subtype of a derivation, its subtype is statically compatible
-- with the subtype of the corresponding parent discriminant (RM 3.7(15)).
procedure Check_Delta_Expression (E : Node_Id);
-- Check that the expression represented by E is suitable for use as a
-- delta expression, i.e. it is of real type and is static.
procedure Check_Digits_Expression (E : Node_Id);
-- Check that the expression represented by E is suitable for use as a
-- digits expression, i.e. it is of integer type, positive and static.
procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
-- Validate the initialization of an object declaration. T is the required
-- type, and Exp is the initialization expression.
procedure Check_Interfaces (N : Node_Id; Def : Node_Id);
-- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
procedure Check_Or_Process_Discriminants
(N : Node_Id;
T : Entity_Id;
Prev : Entity_Id := Empty);
-- If N is the full declaration of the completion T of an incomplete or
-- private type, check its discriminants (which are already known to be
-- conformant with those of the partial view, see Find_Type_Name),
-- otherwise process them. Prev is the entity of the partial declaration,
-- if any.
procedure Check_Real_Bound (Bound : Node_Id);
-- Check given bound for being of real type and static. If not, post an
-- appropriate message, and rewrite the bound with the real literal zero.
procedure Constant_Redeclaration
(Id : Entity_Id;
N : Node_Id;
T : out Entity_Id);
-- Various checks on legality of full declaration of deferred constant.
-- Id is the entity for the redeclaration, N is the N_Object_Declaration,
-- node. The caller has not yet set any attributes of this entity.
function Contain_Interface
(Iface : Entity_Id;
Ifaces : Elist_Id) return Boolean;
-- Ada 2005: Determine whether Iface is present in the list Ifaces
procedure Convert_Scalar_Bounds
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Loc : Source_Ptr);
-- For derived scalar types, convert the bounds in the type definition to
-- the derived type, and complete their analysis. Given a constraint of the
-- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
-- T'Base, the parent_type. The bounds of the derived type (the anonymous
-- base) are copies of Lo and Hi. Finally, the bounds of the derived
-- subtype are conversions of those bounds to the derived_type, so that
-- their typing is consistent.
procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
-- Copies attributes from array base type T2 to array base type T1. Copies
-- only attributes that apply to base types, but not subtypes.
procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
-- Copies attributes from array subtype T2 to array subtype T1. Copies
-- attributes that apply to both subtypes and base types.
procedure Create_Constrained_Components
(Subt : Entity_Id;
Decl_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id);
-- Build the list of entities for a constrained discriminated record
-- subtype. If a component depends on a discriminant, replace its subtype
-- using the discriminant values in the discriminant constraint. Subt
-- is the defining identifier for the subtype whose list of constrained
-- entities we will create. Decl_Node is the type declaration node where
-- we will attach all the itypes created. Typ is the base discriminated
-- type for the subtype Subt. Constraints is the list of discriminant
-- constraints for Typ.
function Constrain_Component_Type
(Comp : Entity_Id;
Constrained_Typ : Entity_Id;
Related_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id) return Entity_Id;
-- Given a discriminated base type Typ, a list of discriminant constraints,
-- Constraints, for Typ and a component Comp of Typ, create and return the
-- type corresponding to Etype (Comp) where all discriminant references
-- are replaced with the corresponding constraint. If Etype (Comp) contains
-- no discriminant references then it is returned as-is. Constrained_Typ
-- is the final constrained subtype to which the constrained component
-- belongs. Related_Node is the node where we attach all created itypes.
procedure Constrain_Access
(Def_Id : in out Entity_Id;
S : Node_Id;
Related_Nod : Node_Id);
-- Apply a list of constraints to an access type. If Def_Id is empty, it is
-- an anonymous type created for a subtype indication. In that case it is
-- created in the procedure and attached to Related_Nod.
procedure Constrain_Array
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character);
-- Apply a list of index constraints to an unconstrained array type. The
-- first parameter is the entity for the resulting subtype. A value of
-- Empty for Def_Id indicates that an implicit type must be created, but
-- creation is delayed (and must be done by this procedure) because other
-- subsidiary implicit types must be created first (which is why Def_Id
-- is an in/out parameter). The second parameter is a subtype indication
-- node for the constrained array to be created (e.g. something of the
-- form string (1 .. 10)). Related_Nod gives the place where this type
-- has to be inserted in the tree. The Related_Id and Suffix parameters
-- are used to build the associated Implicit type name.
procedure Constrain_Concurrent
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character);
-- Apply list of discriminant constraints to an unconstrained concurrent
-- type.
--
-- SI is the N_Subtype_Indication node containing the constraint and
-- the unconstrained type to constrain.
--
-- Def_Id is the entity for the resulting constrained subtype. A value
-- of Empty for Def_Id indicates that an implicit type must be created,
-- but creation is delayed (and must be done by this procedure) because
-- other subsidiary implicit types must be created first (which is why
-- Def_Id is an in/out parameter).
--
-- Related_Nod gives the place where this type has to be inserted
-- in the tree.
--
-- The last two arguments are used to create its external name if needed.
function Constrain_Corresponding_Record
(Prot_Subt : Entity_Id;
Corr_Rec : Entity_Id;
Related_Nod : Node_Id) return Entity_Id;
-- When constraining a protected type or task type with discriminants,
-- constrain the corresponding record with the same discriminant values.
procedure Constrain_Decimal (Def_Id : Entity_Id; S : Node_Id);
-- Constrain a decimal fixed point type with a digits constraint and/or a
-- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
procedure Constrain_Discriminated_Type
(Def_Id : Entity_Id;
S : Node_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False);
-- Process discriminant constraints of composite type. Verify that values
-- have been provided for all discriminants, that the original type is
-- unconstrained, and that the types of the supplied expressions match
-- the discriminant types. The first three parameters are like in routine
-- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
-- of For_Access.
procedure Constrain_Enumeration (Def_Id : Entity_Id; S : Node_Id);
-- Constrain an enumeration type with a range constraint. This is identical
-- to Constrain_Integer, but for the Ekind of the resulting subtype.
procedure Constrain_Float (Def_Id : Entity_Id; S : Node_Id);
-- Constrain a floating point type with either a digits constraint
-- and/or a range constraint, building a E_Floating_Point_Subtype.
procedure Constrain_Index
(Index : Node_Id;
S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character;
Suffix_Index : Pos);
-- Process an index constraint S in a constrained array declaration. The
-- constraint can be a subtype name, or a range with or without an explicit
-- subtype mark. The index is the corresponding index of the unconstrained
-- array. The Related_Id and Suffix parameters are used to build the
-- associated Implicit type name.
procedure Constrain_Integer (Def_Id : Entity_Id; S : Node_Id);
-- Build subtype of a signed or modular integer type
procedure Constrain_Ordinary_Fixed (Def_Id : Entity_Id; S : Node_Id);
-- Constrain an ordinary fixed point type with a range constraint, and
-- build an E_Ordinary_Fixed_Point_Subtype entity.
procedure Copy_And_Swap (Priv, Full : Entity_Id);
-- Copy the Priv entity into the entity of its full declaration then swap
-- the two entities in such a manner that the former private type is now
-- seen as a full type.
procedure Decimal_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id);
-- Create a new decimal fixed point type, and apply the constraint to
-- obtain a subtype of this new type.
procedure Complete_Private_Subtype
(Priv : Entity_Id;
Full : Entity_Id;
Full_Base : Entity_Id;
Related_Nod : Node_Id);
-- Complete the implicit full view of a private subtype by setting the
-- appropriate semantic fields. If the full view of the parent is a record
-- type, build constrained components of subtype.
procedure Derive_Progenitor_Subprograms
(Parent_Type : Entity_Id;
Tagged_Type : Entity_Id);
-- Ada 2005 (AI-251): To complete type derivation, collect the primitive
-- operations of progenitors of Tagged_Type, and replace the subsidiary
-- subtypes with Tagged_Type, to build the specs of the inherited interface
-- primitives. The derived primitives are aliased to those of the
-- interface. This routine takes care also of transferring to the full view
-- subprograms associated with the partial view of Tagged_Type that cover
-- interface primitives.
procedure Derived_Standard_Character
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
-- derivations from types Standard.Character and Standard.Wide_Character.
procedure Derived_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Is_Completion : Boolean);
-- Process a derived type declaration. Build_Derived_Type is invoked
-- to process the actual derived type definition. Parameters N and
-- Is_Completion have the same meaning as in Build_Derived_Type.
-- T is the N_Defining_Identifier for the entity defined in the
-- N_Full_Type_Declaration node N, that is T is the derived type.
procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Insert each literal in symbol table, as an overloadable identifier. Each
-- enumeration type is mapped into a sequence of integers, and each literal
-- is defined as a constant with integer value. If any of the literals are
-- character literals, the type is a character type, which means that
-- strings are legal aggregates for arrays of components of the type.
function Expand_To_Stored_Constraint
(Typ : Entity_Id;
Constraint : Elist_Id) return Elist_Id;
-- Given a constraint (i.e. a list of expressions) on the discriminants of
-- Typ, expand it into a constraint on the stored discriminants and return
-- the new list of expressions constraining the stored discriminants.
function Find_Type_Of_Object
(Obj_Def : Node_Id;
Related_Nod : Node_Id) return Entity_Id;
-- Get type entity for object referenced by Obj_Def, attaching the implicit
-- types generated to Related_Nod.
procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create a new float and apply the constraint to obtain subtype of it
function Has_Range_Constraint (N : Node_Id) return Boolean;
-- Given an N_Subtype_Indication node N, return True if a range constraint
-- is present, either directly, or as part of a digits or delta constraint.
-- In addition, a digits constraint in the decimal case returns True, since
-- it establishes a default range if no explicit range is present.
function Inherit_Components
(N : Node_Id;
Parent_Base : Entity_Id;
Derived_Base : Entity_Id;
Is_Tagged : Boolean;
Inherit_Discr : Boolean;
Discs : Elist_Id) return Elist_Id;
-- Called from Build_Derived_Record_Type to inherit the components of
-- Parent_Base (a base type) into the Derived_Base (the derived base type).
-- For more information on derived types and component inheritance please
-- consult the comment above the body of Build_Derived_Record_Type.
--
-- N is the original derived type declaration
--
-- Is_Tagged is set if we are dealing with tagged types
--
-- If Inherit_Discr is set, Derived_Base inherits its discriminants from
-- Parent_Base, otherwise no discriminants are inherited.
--
-- Discs gives the list of constraints that apply to Parent_Base in the
-- derived type declaration. If Discs is set to No_Elist, then we have
-- the following situation:
--
-- type Parent (D1..Dn : ..) is [tagged] record ...;
-- type Derived is new Parent [with ...];
--
-- which gets treated as
--
-- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
--
-- For untagged types the returned value is an association list. The list
-- starts from the association (Parent_Base => Derived_Base), and then it
-- contains a sequence of the associations of the form
--
-- (Old_Component => New_Component),
--
-- where Old_Component is the Entity_Id of a component in Parent_Base and
-- New_Component is the Entity_Id of the corresponding component in
-- Derived_Base. For untagged records, this association list is needed when
-- copying the record declaration for the derived base. In the tagged case
-- the value returned is irrelevant.
function Is_EVF_Procedure (Subp : Entity_Id) return Boolean;
-- Subsidiary to Check_Abstract_Overriding and Derive_Subprogram.
-- Determine whether subprogram Subp is a procedure subject to pragma
-- Extensions_Visible with value False and has at least one controlling
-- parameter of mode OUT.
function Is_Private_Primitive (Prim : Entity_Id) return Boolean;
-- Subsidiary to Check_Abstract_Overriding and Derive_Subprogram.
-- When applied to a primitive subprogram Prim, returns True if Prim is
-- declared as a private operation within a package or generic package,
-- and returns False otherwise.
function Is_Valid_Constraint_Kind
(T_Kind : Type_Kind;
Constraint_Kind : Node_Kind) return Boolean;
-- Returns True if it is legal to apply the given kind of constraint to the
-- given kind of type (index constraint to an array type, for example).
procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create new modular type. Verify that modulus is in bounds
procedure New_Concatenation_Op (Typ : Entity_Id);
-- Create an abbreviated declaration for an operator in order to
-- materialize concatenation on array types.
procedure Ordinary_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id);
-- Create a new ordinary fixed point type, and apply the constraint to
-- obtain subtype of it.
procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id);
-- Wrapper on Preanalyze_Spec_Expression for default expressions, so that
-- In_Default_Expr can be properly adjusted.
procedure Prepare_Private_Subtype_Completion
(Id : Entity_Id;
Related_Nod : Node_Id);
-- Id is a subtype of some private type. Creates the full declaration
-- associated with Id whenever possible, i.e. when the full declaration
-- of the base type is already known. Records each subtype into
-- Private_Dependents of the base type.
procedure Process_Incomplete_Dependents
(N : Node_Id;
Full_T : Entity_Id;
Inc_T : Entity_Id);
-- Process all entities that depend on an incomplete type. There include
-- subtypes, subprogram types that mention the incomplete type in their
-- profiles, and subprogram with access parameters that designate the
-- incomplete type.
-- Inc_T is the defining identifier of an incomplete type declaration, its
-- Ekind is E_Incomplete_Type.
--
-- N is the corresponding N_Full_Type_Declaration for Inc_T.
--
-- Full_T is N's defining identifier.
--
-- Subtypes of incomplete types with discriminants are completed when the
-- parent type is. This is simpler than private subtypes, because they can
-- only appear in the same scope, and there is no need to exchange views.
-- Similarly, access_to_subprogram types may have a parameter or a return
-- type that is an incomplete type, and that must be replaced with the
-- full type.
--
-- If the full type is tagged, subprogram with access parameters that
-- designated the incomplete may be primitive operations of the full type,
-- and have to be processed accordingly.
procedure Process_Real_Range_Specification (Def : Node_Id);
-- Given the type definition for a real type, this procedure processes and
-- checks the real range specification of this type definition if one is
-- present. If errors are found, error messages are posted, and the
-- Real_Range_Specification of Def is reset to Empty.
procedure Record_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Prev : Entity_Id);
-- Process a record type declaration (for both untagged and tagged
-- records). Parameters T and N are exactly like in procedure
-- Derived_Type_Declaration, except that no flag Is_Completion is needed
-- for this routine. If this is the completion of an incomplete type
-- declaration, Prev is the entity of the incomplete declaration, used for
-- cross-referencing. Otherwise Prev = T.
procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
-- This routine is used to process the actual record type definition (both
-- for untagged and tagged records). Def is a record type definition node.
-- This procedure analyzes the components in this record type definition.
-- Prev_T is the entity for the enclosing record type. It is provided so
-- that its Has_Task flag can be set if any of the component have Has_Task
-- set. If the declaration is the completion of an incomplete type
-- declaration, Prev_T is the original incomplete type, whose full view is
-- the record type.
procedure Replace_Discriminants (Typ : Entity_Id; Decl : Node_Id);
-- Subsidiary to Build_Derived_Record_Type. For untagged record types, we
-- first create the list of components for the derived type from that of
-- the parent by means of Inherit_Components and then build a copy of the
-- declaration tree of the parent with the help of the mapping returned by
-- Inherit_Components, which will for example be used to validate record
-- representation clauses given for the derived type. If the parent type
-- is private and has discriminants, the ancestor discriminants used in the
-- inheritance are that of the private declaration, whereas the ancestor
-- discriminants present in the declaration tree of the parent are that of
-- the full declaration; as a consequence, the remapping done during the
-- copy will leave the references to the ancestor discriminants unchanged
-- in the declaration tree and they need to be fixed up. If the derived
-- type has a known discriminant part, then the remapping done during the
-- copy will only create references to the stored discriminants and they
-- need to be replaced with references to the non-stored discriminants.
procedure Set_Fixed_Range
(E : Entity_Id;
Loc : Source_Ptr;
Lo : Ureal;
Hi : Ureal);
-- Build a range node with the given bounds and set it as the Scalar_Range
-- of the given fixed-point type entity. Loc is the source location used
-- for the constructed range. See body for further details.
procedure Set_Scalar_Range_For_Subtype
(Def_Id : Entity_Id;
R : Node_Id;
Subt : Entity_Id);
-- This routine is used to set the scalar range field for a subtype given
-- Def_Id, the entity for the subtype, and R, the range expression for the
-- scalar range. Subt provides the parent subtype to be used to analyze,
-- resolve, and check the given range.
procedure Set_Default_SSO (T : Entity_Id);
-- T is the entity for an array or record being declared. This procedure
-- sets the flags SSO_Set_Low_By_Default/SSO_Set_High_By_Default according
-- to the setting of Opt.Default_SSO.
procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create a new signed integer entity, and apply the constraint to obtain
-- the required first named subtype of this type.
procedure Set_Stored_Constraint_From_Discriminant_Constraint
(E : Entity_Id);
-- E is some record type. This routine computes E's Stored_Constraint
-- from its Discriminant_Constraint.
procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
-- Check that an entity in a list of progenitors is an interface,
-- emit error otherwise.
-----------------------
-- Access_Definition --
-----------------------
function Access_Definition
(Related_Nod : Node_Id;
N : Node_Id) return Entity_Id
is
Anon_Type : Entity_Id;
Anon_Scope : Entity_Id;
Desig_Type : Entity_Id;
Enclosing_Prot_Type : Entity_Id := Empty;
begin
if Is_Entry (Current_Scope)
and then Is_Task_Type (Etype (Scope (Current_Scope)))
then
Error_Msg_N ("task entries cannot have access parameters", N);
return Empty;
end if;
-- Ada 2005: For an object declaration the corresponding anonymous
-- type is declared in the current scope.
-- If the access definition is the return type of another access to
-- function, scope is the current one, because it is the one of the
-- current type declaration, except for the pathological case below.
if Nkind (Related_Nod) in
N_Object_Declaration | N_Access_Function_Definition
then
Anon_Scope := Current_Scope;
-- A pathological case: function returning access functions that
-- return access functions, etc. Each anonymous access type created
-- is in the enclosing scope of the outermost function.
declare
Par : Node_Id;
begin
Par := Related_Nod;
while Nkind (Par) in
N_Access_Function_Definition | N_Access_Definition
loop
Par := Parent (Par);
end loop;
if Nkind (Par) = N_Function_Specification then
Anon_Scope := Scope (Defining_Entity (Par));
end if;
end;
-- For the anonymous function result case, retrieve the scope of the
-- function specification's associated entity rather than using the
-- current scope. The current scope will be the function itself if the
-- formal part is currently being analyzed, but will be the parent scope
-- in the case of a parameterless function, and we always want to use
-- the function's parent scope. Finally, if the function is a child
-- unit, we must traverse the tree to retrieve the proper entity.
elsif Nkind (Related_Nod) = N_Function_Specification
and then Nkind (Parent (N)) /= N_Parameter_Specification
then
-- If the current scope is a protected type, the anonymous access
-- is associated with one of the protected operations, and must
-- be available in the scope that encloses the protected declaration.
-- Otherwise the type is in the scope enclosing the subprogram.
-- If the function has formals, the return type of a subprogram
-- declaration is analyzed in the scope of the subprogram (see
-- Process_Formals) and thus the protected type, if present, is
-- the scope of the current function scope.
if Ekind (Current_Scope) = E_Protected_Type then
Enclosing_Prot_Type := Current_Scope;
elsif Ekind (Current_Scope) = E_Function
and then Ekind (Scope (Current_Scope)) = E_Protected_Type
then
Enclosing_Prot_Type := Scope (Current_Scope);
end if;
if Present (Enclosing_Prot_Type) then
Anon_Scope := Scope (Enclosing_Prot_Type);
else
Anon_Scope := Scope (Defining_Entity (Related_Nod));
end if;
-- For an access type definition, if the current scope is a child
-- unit it is the scope of the type.
elsif Is_Compilation_Unit (Current_Scope) then
Anon_Scope := Current_Scope;
-- For access formals, access components, and access discriminants, the
-- scope is that of the enclosing declaration,
else
Anon_Scope := Scope (Current_Scope);
end if;
Anon_Type :=
Create_Itype
(E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
if All_Present (N)
and then Ada_Version >= Ada_2005
then
Error_Msg_N ("ALL not permitted for anonymous access types", N);
end if;
-- Ada 2005 (AI-254): In case of anonymous access to subprograms call
-- the corresponding semantic routine
if Present (Access_To_Subprogram_Definition (N)) then
Access_Subprogram_Declaration
(T_Name => Anon_Type,
T_Def => Access_To_Subprogram_Definition (N));
if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
Mutate_Ekind
(Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
else
Mutate_Ekind (Anon_Type, E_Anonymous_Access_Subprogram_Type);
end if;
-- If the anonymous access is associated with a protected operation,
-- create a reference to it after the enclosing protected definition
-- because the itype will be used in the subsequent bodies.
-- If the anonymous access itself is protected, a full type
-- declaratiton will be created for it, so that the equivalent
-- record type can be constructed. For further details, see
-- Replace_Anonymous_Access_To_Protected-Subprogram.
if Ekind (Current_Scope) = E_Protected_Type
and then not Protected_Present (Access_To_Subprogram_Definition (N))
then
Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
end if;
return Anon_Type;
end if;
Find_Type (Subtype_Mark (N));
Desig_Type := Entity (Subtype_Mark (N));
Set_Directly_Designated_Type (Anon_Type, Desig_Type);
Set_Etype (Anon_Type, Anon_Type);
-- Make sure the anonymous access type has size and alignment fields
-- set, as required by gigi. This is necessary in the case of the
-- Task_Body_Procedure.
if not Has_Private_Component (Desig_Type) then
Layout_Type (Anon_Type);
end if;
-- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
-- from Ada 95 semantics. In Ada 2005, anonymous access must specify if
-- the null value is allowed. In Ada 95 the null value is never allowed.
if Ada_Version >= Ada_2005 then
Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
else
Set_Can_Never_Be_Null (Anon_Type, True);
end if;
-- The anonymous access type is as public as the discriminated type or
-- subprogram that defines it. It is imported (for back-end purposes)
-- if the designated type is.
Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
-- Ada 2005 (AI-231): Propagate the access-constant attribute
Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
-- The context is either a subprogram declaration, object declaration,
-- or an access discriminant, in a private or a full type declaration.
-- In the case of a subprogram, if the designated type is incomplete,
-- the operation will be a primitive operation of the full type, to be
-- updated subsequently. If the type is imported through a limited_with
-- clause, the subprogram is not a primitive operation of the type
-- (which is declared elsewhere in some other scope).
if Ekind (Desig_Type) = E_Incomplete_Type
and then not From_Limited_With (Desig_Type)
and then Is_Overloadable (Current_Scope)
then
Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
Set_Has_Delayed_Freeze (Current_Scope);
end if;
-- If the designated type is limited and class-wide, the object might
-- contain tasks, so we create a Master entity for the declaration. This
-- must be done before expansion of the full declaration, because the
-- declaration may include an expression that is an allocator, whose
-- expansion needs the proper Master for the created tasks.
if Expander_Active
and then Nkind (Related_Nod) = N_Object_Declaration
then
if Is_Limited_Record (Desig_Type)
and then Is_Class_Wide_Type (Desig_Type)
then
Build_Class_Wide_Master (Anon_Type);
-- Similarly, if the type is an anonymous access that designates
-- tasks, create a master entity for it in the current context.
elsif Has_Task (Desig_Type)
and then Comes_From_Source (Related_Nod)
then
Build_Master_Entity (Defining_Identifier (Related_Nod));
Build_Master_Renaming (Anon_Type);
end if;
end if;
-- For a private component of a protected type, it is imperative that
-- the back-end elaborate the type immediately after the protected
-- declaration, because this type will be used in the declarations
-- created for the component within each protected body, so we must
-- create an itype reference for it now.
if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
-- Similarly, if the access definition is the return result of a
-- function, create an itype reference for it because it will be used
-- within the function body. For a regular function that is not a
-- compilation unit, insert reference after the declaration. For a
-- protected operation, insert it after the enclosing protected type
-- declaration. In either case, do not create a reference for a type
-- obtained through a limited_with clause, because this would introduce
-- semantic dependencies.
-- Similarly, do not create a reference if the designated type is a
-- generic formal, because no use of it will reach the backend.
elsif Nkind (Related_Nod) = N_Function_Specification
and then not From_Limited_With (Desig_Type)
and then not Is_Generic_Type (Desig_Type)
then
if Present (Enclosing_Prot_Type) then
Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
elsif Is_List_Member (Parent (Related_Nod))
and then Nkind (Parent (N)) /= N_Parameter_Specification
then
Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
end if;
-- Finally, create an itype reference for an object declaration of an
-- anonymous access type. This is strictly necessary only for deferred
-- constants, but in any case will avoid out-of-scope problems in the
-- back-end.
elsif Nkind (Related_Nod) = N_Object_Declaration then
Build_Itype_Reference (Anon_Type, Related_Nod);
end if;
return Anon_Type;
end Access_Definition;
-----------------------------------
-- Access_Subprogram_Declaration --
-----------------------------------
procedure Access_Subprogram_Declaration
(T_Name : Entity_Id;
T_Def : Node_Id)
is
procedure Check_For_Premature_Usage (Def : Node_Id);
-- Check that type T_Name is not used, directly or recursively, as a
-- parameter or a return type in Def. Def is either a subtype, an
-- access_definition, or an access_to_subprogram_definition.
-------------------------------
-- Check_For_Premature_Usage --
-------------------------------
procedure Check_For_Premature_Usage (Def : Node_Id) is
Param : Node_Id;
begin
-- Check for a subtype mark
if Nkind (Def) in N_Has_Etype then
if Etype (Def) = T_Name then
Error_Msg_N
("type& cannot be used before the end of its declaration",
Def);
end if;
-- If this is not a subtype, then this is an access_definition
elsif Nkind (Def) = N_Access_Definition then
if Present (Access_To_Subprogram_Definition (Def)) then
Check_For_Premature_Usage
(Access_To_Subprogram_Definition (Def));
else
Check_For_Premature_Usage (Subtype_Mark (Def));
end if;
-- The only cases left are N_Access_Function_Definition and
-- N_Access_Procedure_Definition.
else
if Present (Parameter_Specifications (Def)) then
Param := First (Parameter_Specifications (Def));
while Present (Param) loop
Check_For_Premature_Usage (Parameter_Type (Param));
Next (Param);
end loop;
end if;
if Nkind (Def) = N_Access_Function_Definition then
Check_For_Premature_Usage (Result_Definition (Def));
end if;
end if;
end Check_For_Premature_Usage;
-- Local variables
Formals : constant List_Id := Parameter_Specifications (T_Def);
Formal : Entity_Id;
D_Ityp : Node_Id;
Desig_Type : constant Entity_Id :=
Create_Itype (E_Subprogram_Type, Parent (T_Def));
-- Start of processing for Access_Subprogram_Declaration
begin
-- Associate the Itype node with the inner full-type declaration or
-- subprogram spec or entry body. This is required to handle nested
-- anonymous declarations. For example:
-- procedure P
-- (X : access procedure
-- (Y : access procedure
-- (Z : access T)))
D_Ityp := Associated_Node_For_Itype (Desig_Type);
while Nkind (D_Ityp) not in N_Full_Type_Declaration
| N_Private_Type_Declaration
| N_Private_Extension_Declaration
| N_Procedure_Specification
| N_Function_Specification
| N_Entry_Body
| N_Object_Declaration
| N_Object_Renaming_Declaration
| N_Formal_Object_Declaration
| N_Formal_Type_Declaration
| N_Task_Type_Declaration
| N_Protected_Type_Declaration
loop
D_Ityp := Parent (D_Ityp);
pragma Assert (D_Ityp /= Empty);
end loop;
Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
if Nkind (D_Ityp) in N_Procedure_Specification | N_Function_Specification
then
Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
elsif Nkind (D_Ityp) in N_Full_Type_Declaration
| N_Object_Declaration
| N_Object_Renaming_Declaration
| N_Formal_Type_Declaration
then
Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
end if;
if Nkind (T_Def) = N_Access_Function_Definition then
if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
declare
Acc : constant Node_Id := Result_Definition (T_Def);
begin
if Present (Access_To_Subprogram_Definition (Acc))
and then
Protected_Present (Access_To_Subprogram_Definition (Acc))
then
Set_Etype
(Desig_Type,
Replace_Anonymous_Access_To_Protected_Subprogram
(T_Def));
else
Set_Etype
(Desig_Type,
Access_Definition (T_Def, Result_Definition (T_Def)));
end if;
end;
else
Analyze (Result_Definition (T_Def));
declare
Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
begin
-- If a null exclusion is imposed on the result type, then
-- create a null-excluding itype (an access subtype) and use
-- it as the function's Etype.
if Is_Access_Type (Typ)
and then Null_Exclusion_In_Return_Present (T_Def)
then
Set_Etype (Desig_Type,
Create_Null_Excluding_Itype
(T => Typ,
Related_Nod => T_Def,
Scope_Id => Current_Scope));
else
if From_Limited_With (Typ) then
-- AI05-151: Incomplete types are allowed in all basic
-- declarations, including access to subprograms.
if Ada_Version >= Ada_2012 then
null;
else
Error_Msg_NE
("illegal use of incomplete type&",
Result_Definition (T_Def), Typ);
end if;
elsif Ekind (Current_Scope) = E_Package
and then In_Private_Part (Current_Scope)
then
if Ekind (Typ) = E_Incomplete_Type then
Append_Elmt (Desig_Type, Private_Dependents (Typ));
elsif Is_Class_Wide_Type (Typ)
and then Ekind (Etype (Typ)) = E_Incomplete_Type
then
Append_Elmt
(Desig_Type, Private_Dependents (Etype (Typ)));
end if;
end if;
Set_Etype (Desig_Type, Typ);
end if;
end;
end if;
if not Is_Type (Etype (Desig_Type)) then
Error_Msg_N
("expect type in function specification",
Result_Definition (T_Def));
end if;
else
Set_Etype (Desig_Type, Standard_Void_Type);
end if;
if Present (Formals) then
Push_Scope (Desig_Type);
-- Some special tests here. These special tests can be removed
-- if and when Itypes always have proper parent pointers to their
-- declarations???
-- Special test 1) Link defining_identifier of formals. Required by
-- First_Formal to provide its functionality.
declare
F : Node_Id;
begin
F := First (Formals);
while Present (F) loop
if No (Parent (Defining_Identifier (F))) then
Set_Parent (Defining_Identifier (F), F);
end if;
Next (F);
end loop;
end;
Process_Formals (Formals, Parent (T_Def));
-- Special test 2) End_Scope requires that the parent pointer be set
-- to something reasonable, but Itypes don't have parent pointers. So
-- we set it and then unset it ???
Set_Parent (Desig_Type, T_Name);
End_Scope;
Set_Parent (Desig_Type, Empty);
end if;
-- Check for premature usage of the type being defined
Check_For_Premature_Usage (T_Def);
-- The return type and/or any parameter type may be incomplete. Mark the
-- subprogram_type as depending on the incomplete type, so that it can
-- be updated when the full type declaration is seen. This only applies
-- to incomplete types declared in some enclosing scope, not to limited
-- views from other packages.
-- Prior to Ada 2012, access to functions can only have in_parameters.
if Present (Formals) then
Formal := First_Formal (Desig_Type);
while Present (Formal) loop
if Ekind (Formal) /= E_In_Parameter
and then Nkind (T_Def) = N_Access_Function_Definition
and then Ada_Version < Ada_2012
then
Error_Msg_N ("functions can only have IN parameters", Formal);
end if;
if Ekind (Etype (Formal)) = E_Incomplete_Type
and then In_Open_Scopes (Scope (Etype (Formal)))
then
Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
Set_Has_Delayed_Freeze (Desig_Type);
end if;
Next_Formal (Formal);
end loop;
end if;
-- Check whether an indirect call without actuals may be possible. This
-- is used when resolving calls whose result is then indexed.
May_Need_Actuals (Desig_Type);
-- If the return type is incomplete, this is legal as long as the type
-- is declared in the current scope and will be completed in it (rather
-- than being part of limited view).
if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
and then not Has_Delayed_Freeze (Desig_Type)
and then In_Open_Scopes (Scope (Etype (Desig_Type)))
then
Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
Set_Has_Delayed_Freeze (Desig_Type);
end if;
Check_Delayed_Subprogram (Desig_Type);
if Protected_Present (T_Def) then
Mutate_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
Set_Convention (Desig_Type, Convention_Protected);
else
Mutate_Ekind (T_Name, E_Access_Subprogram_Type);
end if;
Set_Can_Use_Internal_Rep (T_Name,
not Always_Compatible_Rep_On_Target);
Set_Etype (T_Name, T_Name);
Reinit_Size_Align (T_Name);
Set_Directly_Designated_Type (T_Name, Desig_Type);
-- If the access_to_subprogram is not declared at the library level,
-- it can only point to subprograms that are at the same or deeper
-- accessibility level. The corresponding subprogram type might
-- require an activation record when compiling for C.
Set_Needs_Activation_Record (Desig_Type,
not Is_Library_Level_Entity (T_Name));
Generate_Reference_To_Formals (T_Name);
-- Ada 2005 (AI-231): Propagate the null-excluding attribute
Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
Check_Restriction (No_Access_Subprograms, T_Def);
-- Addition of extra formals must be delayed till the freeze point so
-- that we know the convention.
end Access_Subprogram_Declaration;
----------------------------
-- Access_Type_Declaration --
----------------------------
procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
procedure Setup_Access_Type (Desig_Typ : Entity_Id);
-- After type declaration is analysed with T being an incomplete type,
-- this routine will mutate the kind of T to the appropriate access type
-- and set its directly designated type to Desig_Typ.
-----------------------
-- Setup_Access_Type --
-----------------------
procedure Setup_Access_Type (Desig_Typ : Entity_Id) is
begin
if All_Present (Def) or else Constant_Present (Def) then
Mutate_Ekind (T, E_General_Access_Type);
else
Mutate_Ekind (T, E_Access_Type);
end if;
Set_Directly_Designated_Type (T, Desig_Typ);
end Setup_Access_Type;
-- Local variables
P : constant Node_Id := Parent (Def);
S : constant Node_Id := Subtype_Indication (Def);
Full_Desig : Entity_Id;
-- Start of processing for Access_Type_Declaration
begin
-- Check for permissible use of incomplete type
if Nkind (S) /= N_Subtype_Indication then
Analyze (S);
if Nkind (S) in N_Has_Entity
and then Present (Entity (S))
and then Ekind (Root_Type (Entity (S))) = E_Incomplete_Type
then
Setup_Access_Type (Desig_Typ => Entity (S));
-- If the designated type is a limited view, we cannot tell if
-- the full view contains tasks, and there is no way to handle
-- that full view in a client. We create a master entity for the
-- scope, which will be used when a client determines that one
-- is needed.
if From_Limited_With (Entity (S))
and then not Is_Class_Wide_Type (Entity (S))
then
Build_Master_Entity (T);
Build_Master_Renaming (T);
end if;
else
Setup_Access_Type (Desig_Typ => Process_Subtype (S, P, T, 'P'));
end if;
-- If the access definition is of the form: ACCESS NOT NULL ..
-- the subtype indication must be of an access type. Create
-- a null-excluding subtype of it.
if Null_Excluding_Subtype (Def) then
if not Is_Access_Type (Entity (S)) then
Error_Msg_N ("null exclusion must apply to access type", Def);
else
declare
Loc : constant Source_Ptr := Sloc (S);
Decl : Node_Id;
Nam : constant Entity_Id := Make_Temporary (Loc, 'S');
begin
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Nam,
Subtype_Indication =>
New_Occurrence_Of (Entity (S), Loc));
Set_Null_Exclusion_Present (Decl);
Insert_Before (Parent (Def), Decl);
Analyze (Decl);
Set_Entity (S, Nam);
end;
end if;
end if;
else
Setup_Access_Type (Desig_Typ => Process_Subtype (S, P, T, 'P'));
end if;
if not Error_Posted (T) then
Full_Desig := Designated_Type (T);
if Base_Type (Full_Desig) = T then
Error_Msg_N ("access type cannot designate itself", S);
-- In Ada 2005, the type may have a limited view through some unit in
-- its own context, allowing the following circularity that cannot be
-- detected earlier.
elsif Is_Class_Wide_Type (Full_Desig) and then Etype (Full_Desig) = T
then
Error_Msg_N
("access type cannot designate its own class-wide type", S);
-- Clean up indication of tagged status to prevent cascaded errors
Set_Is_Tagged_Type (T, False);
end if;
Set_Etype (T, T);
-- For SPARK, check that the designated type is compatible with
-- respect to volatility with the access type.
if SPARK_Mode /= Off
and then Comes_From_Source (T)
then
-- ??? UNIMPLEMENTED
-- In the case where the designated type is incomplete at this
-- point, performing this check here is harmless but the check
-- will need to be repeated when the designated type is complete.
-- The preceding call to Comes_From_Source is needed because the
-- FE sometimes introduces implicitly declared access types. See,
-- for example, the expansion of nested_po.ads in OA28-015.
Check_Volatility_Compatibility
(Full_Desig, T, "designated type", "access type",
Srcpos_Bearer => T);
end if;
end if;
-- If the type has appeared already in a with_type clause, it is frozen
-- and the pointer size is already set. Else, initialize.
if not From_Limited_With (T) then
Reinit_Size_Align (T);
end if;
-- Note that Has_Task is always false, since the access type itself
-- is not a task type. See Einfo for more description on this point.
-- Exactly the same consideration applies to Has_Controlled_Component
-- and to Has_Protected.
Set_Has_Task (T, False);
Set_Has_Protected (T, False);
Set_Has_Timing_Event (T, False);
Set_Has_Controlled_Component (T, False);
-- Initialize field Finalization_Master explicitly to Empty, to avoid
-- problems where an incomplete view of this entity has been previously
-- established by a limited with and an overlaid version of this field
-- (Stored_Constraint) was initialized for the incomplete view.
-- This reset is performed in most cases except where the access type
-- has been created for the purposes of allocating or deallocating a
-- build-in-place object. Such access types have explicitly set pools
-- and finalization masters.
if No (Associated_Storage_Pool (T)) then
Set_Finalization_Master (T, Empty);
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
-- attributes
Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
Set_Is_Access_Constant (T, Constant_Present (Def));
end Access_Type_Declaration;
----------------------------------
-- Add_Interface_Tag_Components --
----------------------------------
procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
L : List_Id;
Last_Tag : Node_Id;
procedure Add_Tag (Iface : Entity_Id);
-- Add tag for one of the progenitor interfaces
-------------
-- Add_Tag --
-------------
procedure Add_Tag (Iface : Entity_Id) is
Decl : Node_Id;
Def : Node_Id;
Tag : Entity_Id;
Offset : Entity_Id;
begin
pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface));
-- This is a reasonable place to propagate predicates
if Has_Predicates (Iface) then
Set_Has_Predicates (Typ);
end if;
Def :=
Make_Component_Definition (Loc,
Aliased_Present => True,
Subtype_Indication =>
New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
Tag := Make_Temporary (Loc, 'V');
Decl :=
Make_Component_Declaration (Loc,
Defining_Identifier => Tag,
Component_Definition => Def);
Analyze_Component_Declaration (Decl);
Set_Analyzed (Decl);
Mutate_Ekind (Tag, E_Component);
Set_Is_Tag (Tag);
Set_Is_Aliased (Tag);
Set_Is_Independent (Tag);
Set_Related_Type (Tag, Iface);
Reinit_Component_Location (Tag);
pragma Assert (Is_Frozen (Iface));
Set_DT_Entry_Count (Tag,
DT_Entry_Count (First_Entity (Iface)));
if No (Last_Tag) then
Prepend (Decl, L);
else
Insert_After (Last_Tag, Decl);
end if;
Last_Tag := Decl;
-- If the ancestor has discriminants we need to give special support
-- to store the offset_to_top value of the secondary dispatch tables.
-- For this purpose we add a supplementary component just after the
-- field that contains the tag associated with each secondary DT.
if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then
Def :=
Make_Component_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
Offset := Make_Temporary (Loc, 'V');
Decl :=
Make_Component_Declaration (Loc,
Defining_Identifier => Offset,
Component_Definition => Def);
Analyze_Component_Declaration (Decl);
Set_Analyzed (Decl);
Mutate_Ekind (Offset, E_Component);
Set_Is_Aliased (Offset);
Set_Is_Independent (Offset);
Set_Related_Type (Offset, Iface);
Reinit_Component_Location (Offset);
Insert_After (Last_Tag, Decl);
Last_Tag := Decl;
end if;
end Add_Tag;
-- Local variables
Elmt : Elmt_Id;
Ext : Node_Id;
Comp : Node_Id;
-- Start of processing for Add_Interface_Tag_Components
begin
if not RTE_Available (RE_Interface_Tag) then
Error_Msg_N
("(Ada 2005) interface types not supported by this run-time!", N);
return;
end if;
if Ekind (Typ) /= E_Record_Type
or else (Is_Concurrent_Record_Type (Typ)
and then Is_Empty_List (Abstract_Interface_List (Typ)))
or else (not Is_Concurrent_Record_Type (Typ)
and then No (Interfaces (Typ))
and then Is_Empty_Elmt_List (Interfaces (Typ)))
then
return;
end if;
-- Find the current last tag
if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
Ext := Record_Extension_Part (Type_Definition (N));
else
pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
Ext := Type_Definition (N);
end if;
Last_Tag := Empty;
if not (Present (Component_List (Ext))) then
Set_Null_Present (Ext, False);
L := New_List;
Set_Component_List (Ext,
Make_Component_List (Loc,
Component_Items => L,
Null_Present => False));
else
if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
L := Component_Items
(Component_List
(Record_Extension_Part
(Type_Definition (N))));
else
L := Component_Items
(Component_List
(Type_Definition (N)));
end if;
-- Find the last tag component
Comp := First (L);
while Present (Comp) loop
if Nkind (Comp) = N_Component_Declaration
and then Is_Tag (Defining_Identifier (Comp))
then
Last_Tag := Comp;
end if;
Next (Comp);
end loop;
end if;
-- At this point L references the list of components and Last_Tag
-- references the current last tag (if any). Now we add the tag
-- corresponding with all the interfaces that are not implemented
-- by the parent.
if Present (Interfaces (Typ)) then
Elmt := First_Elmt (Interfaces (Typ));
while Present (Elmt) loop
Add_Tag (Node (Elmt));
Next_Elmt (Elmt);
end loop;
end if;
end Add_Interface_Tag_Components;
-------------------------------------
-- Add_Internal_Interface_Entities --
-------------------------------------
procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
Elmt : Elmt_Id;
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
Iface_Prim : Entity_Id;
Ifaces_List : Elist_Id;
New_Subp : Entity_Id := Empty;
Prim : Entity_Id;
Restore_Scope : Boolean := False;
begin
pragma Assert (Ada_Version >= Ada_2005
and then Is_Record_Type (Tagged_Type)
and then Is_Tagged_Type (Tagged_Type)
and then Has_Interfaces (Tagged_Type)
and then not Is_Interface (Tagged_Type));
-- Ensure that the internal entities are added to the scope of the type
if Scope (Tagged_Type) /= Current_Scope then
Push_Scope (Scope (Tagged_Type));
Restore_Scope := True;
end if;
Collect_Interfaces (Tagged_Type, Ifaces_List);
Iface_Elmt := First_Elmt (Ifaces_List);
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
-- Originally we excluded here from this processing interfaces that
-- are parents of Tagged_Type because their primitives are located
-- in the primary dispatch table (and hence no auxiliary internal
-- entities are required to handle secondary dispatch tables in such
-- case). However, these auxiliary entities are also required to
-- handle derivations of interfaces in formals of generics (see
-- Derive_Subprograms).
Elmt := First_Elmt (Primitive_Operations (Iface));
while Present (Elmt) loop
Iface_Prim := Node (Elmt);
if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
Prim :=
Find_Primitive_Covering_Interface
(Tagged_Type => Tagged_Type,
Iface_Prim => Iface_Prim);
if No (Prim) and then Serious_Errors_Detected > 0 then
goto Continue;
end if;
pragma Assert (Present (Prim));
-- Ada 2012 (AI05-0197): If the name of the covering primitive
-- differs from the name of the interface primitive then it is
-- a private primitive inherited from a parent type. In such
-- case, given that Tagged_Type covers the interface, the
-- inherited private primitive becomes visible. For such
-- purpose we add a new entity that renames the inherited
-- private primitive.
if Chars (Prim) /= Chars (Iface_Prim) then
pragma Assert (Has_Suffix (Prim, 'P'));
Derive_Subprogram
(New_Subp => New_Subp,
Parent_Subp => Iface_Prim,
Derived_Type => Tagged_Type,
Parent_Type => Iface);
Set_Alias (New_Subp, Prim);
Set_Is_Abstract_Subprogram
(New_Subp, Is_Abstract_Subprogram (Prim));
end if;
Derive_Subprogram
(New_Subp => New_Subp,
Parent_Subp => Iface_Prim,
Derived_Type => Tagged_Type,
Parent_Type => Iface);
declare
Anc : Entity_Id;
begin
if Is_Inherited_Operation (Prim)
and then Present (Alias (Prim))
then
Anc := Alias (Prim);
else
Anc := Overridden_Operation (Prim);
end if;
-- Apply legality checks in RM 6.1.1 (10-13) concerning
-- nonconforming preconditions in both an ancestor and
-- a progenitor operation.
-- If the operation is a primitive wrapper it is an explicit
-- (overriding) operqtion and all is fine.
if Present (Anc)
and then Has_Non_Trivial_Precondition (Anc)
and then Has_Non_Trivial_Precondition (Iface_Prim)
then
if Is_Abstract_Subprogram (Prim)
or else
(Ekind (Prim) = E_Procedure
and then Nkind (Parent (Prim)) =
N_Procedure_Specification
and then Null_Present (Parent (Prim)))
or else Is_Primitive_Wrapper (Prim)
then
null;
-- The operation is inherited and must be overridden
elsif not Comes_From_Source (Prim) then
Error_Msg_NE
("&inherits non-conforming preconditions and must "
& "be overridden (RM 6.1.1 (10-16))",
Parent (Tagged_Type), Prim);
end if;
end if;
end;
-- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
-- associated with interface types. These entities are
-- only registered in the list of primitives of its
-- corresponding tagged type because they are only used
-- to fill the contents of the secondary dispatch tables.
-- Therefore they are removed from the homonym chains.
Set_Is_Hidden (New_Subp);
Set_Is_Internal (New_Subp);
Set_Alias (New_Subp, Prim);
Set_Is_Abstract_Subprogram
(New_Subp, Is_Abstract_Subprogram (Prim));
Set_Interface_Alias (New_Subp, Iface_Prim);
-- If the returned type is an interface then propagate it to
-- the returned type. Needed by the thunk to generate the code
-- which displaces "this" to reference the corresponding
-- secondary dispatch table in the returned object.
if Is_Interface (Etype (Iface_Prim)) then
Set_Etype (New_Subp, Etype (Iface_Prim));
end if;
-- Internal entities associated with interface types are only
-- registered in the list of primitives of the tagged type.
-- They are only used to fill the contents of the secondary
-- dispatch tables. Therefore they are not needed in the
-- homonym chains.
Remove_Homonym (New_Subp);
-- Hidden entities associated with interfaces must have set
-- the Has_Delay_Freeze attribute to ensure that, in case
-- of locally defined tagged types (or compiling with static
-- dispatch tables generation disabled) the corresponding
-- entry of the secondary dispatch table is filled when such
-- an entity is frozen.
Set_Has_Delayed_Freeze (New_Subp);
end if;
<<Continue>>
Next_Elmt (Elmt);
end loop;
Next_Elmt (Iface_Elmt);
end loop;
if Restore_Scope then
Pop_Scope;
end if;
end Add_Internal_Interface_Entities;
-----------------------------------
-- Analyze_Component_Declaration --
-----------------------------------
procedure Analyze_Component_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (Component_Definition (N));
Id : constant Entity_Id := Defining_Identifier (N);
E : constant Node_Id := Expression (N);
Typ : constant Node_Id :=
Subtype_Indication (Component_Definition (N));
T : Entity_Id;
P : Entity_Id;
function Contains_POC (Constr : Node_Id) return Boolean;
-- Determines whether a constraint uses the discriminant of a record
-- type thus becoming a per-object constraint (POC).
function Is_Known_Limited (Typ : Entity_Id) return Boolean;
-- Typ is the type of the current component, check whether this type is
-- a limited type. Used to validate declaration against that of
-- enclosing record.
------------------
-- Contains_POC --
------------------
function Contains_POC (Constr : Node_Id) return Boolean is
begin
-- Prevent cascaded errors
if Error_Posted (Constr) then
return False;
end if;
case Nkind (Constr) is
when N_Attribute_Reference =>
return Attribute_Name (Constr) = Name_Access
and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
when N_Discriminant_Association =>
return Denotes_Discriminant (Expression (Constr));
when N_Identifier =>
return Denotes_Discriminant (Constr);
when N_Index_Or_Discriminant_Constraint =>
declare
IDC : Node_Id;
begin
IDC := First (Constraints (Constr));
while Present (IDC) loop
-- One per-object constraint is sufficient
if Contains_POC (IDC) then
return True;
end if;
Next (IDC);
end loop;
return False;
end;
when N_Range =>
return Denotes_Discriminant (Low_Bound (Constr))
or else
Denotes_Discriminant (High_Bound (Constr));
when N_Range_Constraint =>
return Denotes_Discriminant (Range_Expression (Constr));
when others =>
return False;
end case;
end Contains_POC;
----------------------
-- Is_Known_Limited --
----------------------
function Is_Known_Limited (Typ : Entity_Id) return Boolean is
P : constant Entity_Id := Etype (Typ);
R : constant Entity_Id := Root_Type (Typ);
begin
if Is_Limited_Record (Typ) then
return True;
-- If the root type is limited (and not a limited interface) so is
-- the current type.
elsif Is_Limited_Record (R)
and then (not Is_Interface (R) or else not Is_Limited_Interface (R))
then
return True;
-- Else the type may have a limited interface progenitor, but a
-- limited record parent that is not an interface.
elsif R /= P
and then Is_Limited_Record (P)
and then not Is_Interface (P)
then
return True;
else
return False;
end if;
end Is_Known_Limited;
-- Start of processing for Analyze_Component_Declaration
begin
Generate_Definition (Id);
Enter_Name (Id);
if Present (Typ) then
T := Find_Type_Of_Object
(Subtype_Indication (Component_Definition (N)), N);
-- Ada 2005 (AI-230): Access Definition case
else
pragma Assert (Present
(Access_Definition (Component_Definition (N))));
T := Access_Definition
(Related_Nod => N,
N => Access_Definition (Component_Definition (N)));
Set_Is_Local_Anonymous_Access (T);
-- Ada 2005 (AI-254)
if Present (Access_To_Subprogram_Definition
(Access_Definition (Component_Definition (N))))
and then Protected_Present (Access_To_Subprogram_Definition
(Access_Definition
(Component_Definition (N))))
then
T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
end if;
end if;
-- If the subtype is a constrained subtype of the enclosing record,
-- (which must have a partial view) the back-end does not properly
-- handle the recursion. Rewrite the component declaration with an
-- explicit subtype indication, which is acceptable to Gigi. We can copy
-- the tree directly because side effects have already been removed from
-- discriminant constraints.
if Ekind (T) = E_Access_Subtype
and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
and then Comes_From_Source (T)
and then Nkind (Parent (T)) = N_Subtype_Declaration
and then Etype (Directly_Designated_Type (T)) = Current_Scope
then
Rewrite
(Subtype_Indication (Component_Definition (N)),
New_Copy_Tree (Subtype_Indication (Parent (T))));
T := Find_Type_Of_Object
(Subtype_Indication (Component_Definition (N)), N);
end if;
-- If the component declaration includes a default expression, then we
-- check that the component is not of a limited type (RM 3.7(5)),
-- and do the special preanalysis of the expression (see section on
-- "Handling of Default and Per-Object Expressions" in the spec of
-- package Sem).
if Present (E) then
Preanalyze_Default_Expression (E, T);
Check_Initialization (T, E);
if Ada_Version >= Ada_2005
and then Ekind (T) = E_Anonymous_Access_Type
and then Etype (E) /= Any_Type
then
-- Check RM 3.9.2(9): "if the expected type for an expression is
-- an anonymous access-to-specific tagged type, then the object
-- designated by the expression shall not be dynamically tagged
-- unless it is a controlling operand in a call on a dispatching
-- operation"
if Is_Tagged_Type (Directly_Designated_Type (T))
and then
Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
and then
Ekind (Directly_Designated_Type (Etype (E))) =
E_Class_Wide_Type
then
Error_Msg_N
("access to specific tagged type required (RM 3.9.2(9))", E);
end if;
-- (Ada 2005: AI-230): Accessibility check for anonymous
-- components
if Type_Access_Level (Etype (E)) >
Deepest_Type_Access_Level (T)
then
Error_Msg_N
("expression has deeper access level than component " &
"(RM 3.10.2 (12.2))", E);
end if;
-- The initialization expression is a reference to an access
-- discriminant. The type of the discriminant is always deeper
-- than any access type.
if Ekind (Etype (E)) = E_Anonymous_Access_Type
and then Is_Entity_Name (E)
and then Ekind (Entity (E)) = E_In_Parameter
and then Present (Discriminal_Link (Entity (E)))
then
Error_Msg_N
("discriminant has deeper accessibility level than target",
E);
end if;
end if;
end if;
-- The parent type may be a private view with unknown discriminants,
-- and thus unconstrained. Regular components must be constrained.
if not Is_Definite_Subtype (T)
and then Chars (Id) /= Name_uParent
then
if Is_Class_Wide_Type (T) then
Error_Msg_N
("class-wide subtype with unknown discriminants" &
" in component declaration",
Subtype_Indication (Component_Definition (N)));
else
Error_Msg_N
("unconstrained subtype in component declaration",
Subtype_Indication (Component_Definition (N)));
end if;
-- Components cannot be abstract, except for the special case of
-- the _Parent field (case of extending an abstract tagged type)
elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then
Error_Msg_N ("type of a component cannot be abstract", N);
end if;
Set_Etype (Id, T);
if Aliased_Present (Component_Definition (N)) then
Set_Is_Aliased (Id);
-- AI12-001: All aliased objects are considered to be specified as
-- independently addressable (RM C.6(8.1/4)).
Set_Is_Independent (Id);
end if;
-- The component declaration may have a per-object constraint, set
-- the appropriate flag in the defining identifier of the subtype.
if Present (Subtype_Indication (Component_Definition (N))) then
declare
Sindic : constant Node_Id :=
Subtype_Indication (Component_Definition (N));
begin
if Nkind (Sindic) = N_Subtype_Indication
and then Present (Constraint (Sindic))
and then Contains_POC (Constraint (Sindic))
then
Set_Has_Per_Object_Constraint (Id);
end if;
end;
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
-- out some static checks.
if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then
Null_Exclusion_Static_Checks (N);
end if;
-- If this component is private (or depends on a private type), flag the
-- record type to indicate that some operations are not available.
P := Private_Component (T);
if Present (P) then
-- Check for circular definitions
if P = Any_Type then
Set_Etype (Id, Any_Type);
-- There is a gap in the visibility of operations only if the
-- component type is not defined in the scope of the record type.
elsif Scope (P) = Scope (Current_Scope) then
null;
elsif Is_Limited_Type (P) then
Set_Is_Limited_Composite (Current_Scope);
else
Set_Is_Private_Composite (Current_Scope);
end if;
end if;
if P /= Any_Type
and then Is_Limited_Type (T)
and then Chars (Id) /= Name_uParent
and then Is_Tagged_Type (Current_Scope)
then
if Is_Derived_Type (Current_Scope)
and then not Is_Known_Limited (Current_Scope)
then
Error_Msg_N
("extension of nonlimited type cannot have limited components",
N);
if Is_Interface (Root_Type (Current_Scope)) then
Error_Msg_N
("\limitedness is not inherited from limited interface", N);
Error_Msg_N ("\add LIMITED to type indication", N);
end if;
Explain_Limited_Type (T, N);
Set_Etype (Id, Any_Type);
Set_Is_Limited_Composite (Current_Scope, False);
elsif not Is_Derived_Type (Current_Scope)
and then not Is_Limited_Record (Current_Scope)
and then not Is_Concurrent_Type (Current_Scope)
then
Error_Msg_N
("nonlimited tagged type cannot have limited components", N);
Explain_Limited_Type (T, N);
Set_Etype (Id, Any_Type);
Set_Is_Limited_Composite (Current_Scope, False);
end if;
end if;
-- When possible, build the default subtype
if Build_Default_Subtype_OK (T) then
declare
Act_T : constant Entity_Id := Build_Default_Subtype (T, N);
begin
Set_Etype (Id, Act_T);
-- Rewrite component definition to use the constrained subtype
Rewrite (Component_Definition (N),
Make_Component_Definition (Loc,
Subtype_Indication => New_Occurrence_Of (Act_T, Loc)));
end;
end if;
Set_Original_Record_Component (Id, Id);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
Analyze_Dimension (N);
end Analyze_Component_Declaration;
--------------------------
-- Analyze_Declarations --
--------------------------
procedure Analyze_Declarations (L : List_Id) is
Decl : Node_Id;
procedure Adjust_Decl;
-- Adjust Decl not to include implicit label declarations, since these
-- have strange Sloc values that result in elaboration check problems.
-- (They have the sloc of the label as found in the source, and that
-- is ahead of the current declarative part).
procedure Build_Assertion_Bodies (Decls : List_Id; Context : Node_Id);
-- Create the subprogram bodies which verify the run-time semantics of
-- the pragmas listed below for each elibigle type found in declarative
-- list Decls. The pragmas are:
--
-- Default_Initial_Condition
-- Invariant
-- Type_Invariant
--
-- Context denotes the owner of the declarative list.
procedure Check_Entry_Contracts;
-- Perform a preanalysis of the pre- and postconditions of an entry
-- declaration. This must be done before full resolution and creation
-- of the parameter block, etc. to catch illegal uses within the
-- contract expression. Full analysis of the expression is done when
-- the contract is processed.
function Contains_Lib_Incomplete_Type (Pkg : Entity_Id) return Boolean;
-- Check if a nested package has entities within it that rely on library
-- level private types where the full view has not been completed for
-- the purposes of checking if it is acceptable to freeze an expression
-- function at the point of declaration.
procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id);
-- Determine whether Body_Decl denotes the body of a late controlled
-- primitive (either Initialize, Adjust or Finalize). If this is the
-- case, add a proper spec if the body lacks one. The spec is inserted
-- before Body_Decl and immediately analyzed.
procedure Remove_Partial_Visible_Refinements (Spec_Id : Entity_Id);
-- Spec_Id is the entity of a package that may define abstract states,
-- and in the case of a child unit, whose ancestors may define abstract
-- states. If the states have partial visible refinement, remove the
-- partial visibility of each constituent at the end of the package
-- spec and body declarations.
procedure Remove_Visible_Refinements (Spec_Id : Entity_Id);
-- Spec_Id is the entity of a package that may define abstract states.
-- If the states have visible refinement, remove the visibility of each
-- constituent at the end of the package body declaration.
procedure Resolve_Aspects;
-- Utility to resolve the expressions of aspects at the end of a list of
-- declarations, or before a declaration that freezes previous entities,
-- such as in a subprogram body.
-----------------
-- Adjust_Decl --
-----------------
procedure Adjust_Decl is
begin
while Present (Prev (Decl))
and then Nkind (Decl) = N_Implicit_Label_Declaration
loop
Prev (Decl);
end loop;
end Adjust_Decl;
----------------------------
-- Build_Assertion_Bodies --
----------------------------
procedure Build_Assertion_Bodies (Decls : List_Id; Context : Node_Id) is
procedure Build_Assertion_Bodies_For_Type (Typ : Entity_Id);
-- Create the subprogram bodies which verify the run-time semantics
-- of the pragmas listed below for type Typ. The pragmas are:
--
-- Default_Initial_Condition
-- Invariant
-- Type_Invariant
-------------------------------------
-- Build_Assertion_Bodies_For_Type --
-------------------------------------
procedure Build_Assertion_Bodies_For_Type (Typ : Entity_Id) is
begin
if Nkind (Context) = N_Package_Specification then
-- Preanalyze and resolve the class-wide invariants of an
-- interface at the end of whichever declarative part has the
-- interface type. Note that an interface may be declared in
-- any non-package declarative part, but reaching the end of
-- such a declarative part will always freeze the type and
-- generate the invariant procedure (see Freeze_Type).
if Is_Interface (Typ) then
-- Interfaces are treated as the partial view of a private
-- type, in order to achieve uniformity with the general
-- case. As a result, an interface receives only a "partial"
-- invariant procedure, which is never called.
if Has_Own_Invariants (Typ) then
Build_Invariant_Procedure_Body
(Typ => Typ,
Partial_Invariant => True);
end if;
elsif Decls = Visible_Declarations (Context) then
-- Preanalyze and resolve the invariants of a private type
-- at the end of the visible declarations to catch potential
-- errors. Inherited class-wide invariants are not included
-- because they have already been resolved.
if Ekind (Typ) in E_Limited_Private_Type
| E_Private_Type
| E_Record_Type_With_Private
and then Has_Own_Invariants (Typ)
then
Build_Invariant_Procedure_Body
(Typ => Typ,
Partial_Invariant => True);
end if;
-- Preanalyze and resolve the Default_Initial_Condition
-- assertion expression at the end of the declarations to
-- catch any errors.
if Ekind (Typ) in E_Limited_Private_Type
| E_Private_Type
| E_Record_Type_With_Private
and then Has_Own_DIC (Typ)
then
Build_DIC_Procedure_Body
(Typ => Typ,
Partial_DIC => True);
end if;
elsif Decls = Private_Declarations (Context) then
-- Preanalyze and resolve the invariants of a private type's
-- full view at the end of the private declarations to catch
-- potential errors.
if (not Is_Private_Type (Typ)
or else Present (Underlying_Full_View (Typ)))
and then Has_Private_Declaration (Typ)
and then Has_Invariants (Typ)
then
Build_Invariant_Procedure_Body (Typ);
end if;
if (not Is_Private_Type (Typ)
or else Present (Underlying_Full_View (Typ)))
and then Has_Private_Declaration (Typ)
and then Has_DIC (Typ)
then
Build_DIC_Procedure_Body (Typ);
end if;
end if;
end if;
end Build_Assertion_Bodies_For_Type;
-- Local variables
Decl : Node_Id;
Decl_Id : Entity_Id;
-- Start of processing for Build_Assertion_Bodies
begin
Decl := First (Decls);
while Present (Decl) loop
if Is_Declaration (Decl) then
Decl_Id := Defining_Entity (Decl);
if Is_Type (Decl_Id) then
Build_Assertion_Bodies_For_Type (Decl_Id);
end if;
end if;
Next (Decl);
end loop;
end Build_Assertion_Bodies;
---------------------------
-- Check_Entry_Contracts --
---------------------------
procedure Check_Entry_Contracts is
ASN : Node_Id;
Ent : Entity_Id;
Exp : Node_Id;
begin
Ent := First_Entity (Current_Scope);
while Present (Ent) loop
-- This only concerns entries with pre/postconditions
if Ekind (Ent) = E_Entry
and then Present (Contract (Ent))
and then Present (Pre_Post_Conditions (Contract (Ent)))
then
ASN := Pre_Post_Conditions (Contract (Ent));
Push_Scope (Ent);
Install_Formals (Ent);
-- Pre/postconditions are rewritten as Check pragmas. Analysis
-- is performed on a copy of the pragma expression, to prevent
-- modifying the original expression.
while Present (ASN) loop
if Nkind (ASN) = N_Pragma then
Exp :=
New_Copy_Tree
(Expression
(First (Pragma_Argument_Associations (ASN))));
Set_Parent (Exp, ASN);
Preanalyze_Assert_Expression (Exp, Standard_Boolean);
end if;
ASN := Next_Pragma (ASN);
end loop;
End_Scope;
end if;
Next_Entity (Ent);
end loop;
end Check_Entry_Contracts;
----------------------------------
-- Contains_Lib_Incomplete_Type --
----------------------------------
function Contains_Lib_Incomplete_Type (Pkg : Entity_Id) return Boolean is
Curr : Entity_Id;
begin
-- Avoid looking through scopes that do not meet the precondition of
-- Pkg not being within a library unit spec.
if not Is_Compilation_Unit (Pkg)
and then not Is_Generic_Instance (Pkg)
and then not In_Package_Body (Enclosing_Lib_Unit_Entity (Pkg))
then
-- Loop through all entities in the current scope to identify
-- an entity that depends on a private type.
Curr := First_Entity (Pkg);
loop
if Nkind (Curr) in N_Entity
and then Depends_On_Private (Curr)
then
return True;
end if;
exit when Last_Entity (Current_Scope) = Curr;
Next_Entity (Curr);
end loop;
end if;
return False;
end Contains_Lib_Incomplete_Type;
--------------------------------------
-- Handle_Late_Controlled_Primitive --
--------------------------------------
procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id) is
Body_Spec : constant Node_Id := Specification (Body_Decl);
Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
Loc : constant Source_Ptr := Sloc (Body_Id);
Params : constant List_Id :=
Parameter_Specifications (Body_Spec);
Spec : Node_Id;
Spec_Id : Entity_Id;
Typ : Node_Id;
begin
-- Consider only procedure bodies whose name matches one of the three
-- controlled primitives.
if Nkind (Body_Spec) /= N_Procedure_Specification
or else Chars (Body_Id) not in Name_Adjust
| Name_Finalize
| Name_Initialize
then
return;
-- A controlled primitive must have exactly one formal which is not
-- an anonymous access type.
elsif List_Length (Params) /= 1 then
return;
end if;
Typ := Parameter_Type (First (Params));
if Nkind (Typ) = N_Access_Definition then
return;
end if;
Find_Type (Typ);
-- The type of the formal must be derived from [Limited_]Controlled
if not Is_Controlled (Entity (Typ)) then
return;
end if;
-- Check whether a specification exists for this body. We do not
-- analyze the spec of the body in full, because it will be analyzed
-- again when the body is properly analyzed, and we cannot create
-- duplicate entries in the formals chain. We look for an explicit
-- specification because the body may be an overriding operation and
-- an inherited spec may be present.
Spec_Id := Current_Entity (Body_Id);
while Present (Spec_Id) loop
if Ekind (Spec_Id) in E_Procedure | E_Generic_Procedure
and then Scope (Spec_Id) = Current_Scope
and then Present (First_Formal (Spec_Id))
and then No (Next_Formal (First_Formal (Spec_Id)))
and then Etype (First_Formal (Spec_Id)) = Entity (Typ)
and then Comes_From_Source (Spec_Id)
then
return;
end if;
Spec_Id := Homonym (Spec_Id);
end loop;
-- At this point the body is known to be a late controlled primitive.
-- Generate a matching spec and insert it before the body. Note the
-- use of Copy_Separate_Tree - we want an entirely separate semantic
-- tree in this case.
Spec := Copy_Separate_Tree (Body_Spec);
-- Ensure that the subprogram declaration does not inherit the null
-- indicator from the body as we now have a proper spec/body pair.
Set_Null_Present (Spec, False);
-- Ensure that the freeze node is inserted after the declaration of
-- the primitive since its expansion will freeze the primitive.
Decl := Make_Subprogram_Declaration (Loc, Specification => Spec);
Insert_Before_And_Analyze (Body_Decl, Decl);
end Handle_Late_Controlled_Primitive;
----------------------------------------
-- Remove_Partial_Visible_Refinements --
----------------------------------------
procedure Remove_Partial_Visible_Refinements (Spec_Id : Entity_Id) is
State_Elmt : Elmt_Id;
begin
if Present (Abstract_States (Spec_Id)) then
State_Elmt := First_Elmt (Abstract_States (Spec_Id));
while Present (State_Elmt) loop
Set_Has_Partial_Visible_Refinement (Node (State_Elmt), False);
Next_Elmt (State_Elmt);
end loop;
end if;
-- For a child unit, also hide the partial state refinement from
-- ancestor packages.
if Is_Child_Unit (Spec_Id) then
Remove_Partial_Visible_Refinements (Scope (Spec_Id));
end if;
end Remove_Partial_Visible_Refinements;
--------------------------------
-- Remove_Visible_Refinements --
--------------------------------
procedure Remove_Visible_Refinements (Spec_Id : Entity_Id) is
State_Elmt : Elmt_Id;
begin
if Present (Abstract_States (Spec_Id)) then
State_Elmt := First_Elmt (Abstract_States (Spec_Id));
while Present (State_Elmt) loop
Set_Has_Visible_Refinement (Node (State_Elmt), False);
Next_Elmt (State_Elmt);
end loop;
end if;
end Remove_Visible_Refinements;
---------------------
-- Resolve_Aspects --
---------------------
procedure Resolve_Aspects is
E : Entity_Id;
begin
E := First_Entity (Current_Scope);
while Present (E) loop
Resolve_Aspect_Expressions (E);
-- Now that the aspect expressions have been resolved, if this is
-- at the end of the visible declarations, we can set the flag
-- Known_To_Have_Preelab_Init properly on types declared in the
-- visible part, which is needed for checking whether full types
-- in the private part satisfy the Preelaborable_Initialization
-- aspect of the partial view. We can't wait for the creation of
-- the pragma by Analyze_Aspects_At_Freeze_Point, because the
-- freeze point may occur after the end of the package declaration
-- (in the case of nested packages).
if Is_Type (E)
and then L = Visible_Declarations (Parent (L))
and then Has_Aspect (E, Aspect_Preelaborable_Initialization)
then
declare
ASN : constant Node_Id :=
Find_Aspect (E, Aspect_Preelaborable_Initialization);
Expr : constant Node_Id := Expression (ASN);
begin
-- Set Known_To_Have_Preelab_Init to True if aspect has no
-- expression, or if the expression is True (or was folded
-- to True), or if the expression is a conjunction of one or
-- more Preelaborable_Initialization attributes applied to
-- formal types and wasn't folded to False. (Note that
-- Is_Conjunction_Of_Formal_Preelab_Init_Attributes goes to
-- Original_Node if needed, hence test for Standard_False.)
if No (Expr)
or else (Is_Entity_Name (Expr)
and then Entity (Expr) = Standard_True)
or else
(Is_Conjunction_Of_Formal_Preelab_Init_Attributes (Expr)
and then
not (Is_Entity_Name (Expr)
and then Entity (Expr) = Standard_False))
then
Set_Known_To_Have_Preelab_Init (E);
end if;
end;
end if;
Next_Entity (E);
end loop;
end Resolve_Aspects;
-- Local variables
Context : Node_Id := Empty;
Ctrl_Typ : Entity_Id := Empty;
Freeze_From : Entity_Id := Empty;
Next_Decl : Node_Id;
-- Start of processing for Analyze_Declarations
begin
Decl := First (L);
while Present (Decl) loop
-- Complete analysis of declaration
Analyze (Decl);
Next_Decl := Next (Decl);
if No (Freeze_From) then
Freeze_From := First_Entity (Current_Scope);
end if;
-- Remember if the declaration we just processed is the full type
-- declaration of a controlled type (to handle late overriding of
-- initialize, adjust or finalize).
if Nkind (Decl) = N_Full_Type_Declaration
and then Is_Controlled (Defining_Identifier (Decl))
then
Ctrl_Typ := Defining_Identifier (Decl);
end if;
-- At the end of a declarative part, freeze remaining entities
-- declared in it. The end of the visible declarations of package
-- specification is not the end of a declarative part if private
-- declarations are present. The end of a package declaration is a
-- freezing point only if it a library package. A task definition or
-- protected type definition is not a freeze point either. Finally,
-- we do not freeze entities in generic scopes, because there is no
-- code generated for them and freeze nodes will be generated for
-- the instance.
-- The end of a package instantiation is not a freeze point, but
-- for now we make it one, because the generic body is inserted
-- (currently) immediately after. Generic instantiations will not
-- be a freeze point once delayed freezing of bodies is implemented.
-- (This is needed in any case for early instantiations ???).
if No (Next_Decl) then
if Nkind (Parent (L)) = N_Component_List then
null;
elsif Nkind (Parent (L)) in
N_Protected_Definition | N_Task_Definition
then
Check_Entry_Contracts;
elsif Nkind (Parent (L)) /= N_Package_Specification then
if Nkind (Parent (L)) = N_Package_Body then
Freeze_From := First_Entity (Current_Scope);
end if;
-- There may have been several freezing points previously,
-- for example object declarations or subprogram bodies, but
-- at the end of a declarative part we check freezing from
-- the beginning, even though entities may already be frozen,
-- in order to perform visibility checks on delayed aspects.
Adjust_Decl;
-- If the current scope is a generic subprogram body. Skip the
-- generic formal parameters that are not frozen here.
if Is_Subprogram (Current_Scope)
and then Nkind (Unit_Declaration_Node (Current_Scope)) =
N_Generic_Subprogram_Declaration
and then Present (First_Entity (Current_Scope))
then
while Is_Generic_Formal (Freeze_From) loop
Next_Entity (Freeze_From);
end loop;
Freeze_All (Freeze_From, Decl);
Freeze_From := Last_Entity (Current_Scope);
else
-- For declarations in a subprogram body there is no issue
-- with name resolution in aspect specifications.
Freeze_All (First_Entity (Current_Scope), Decl);
Freeze_From := Last_Entity (Current_Scope);
end if;
-- Current scope is a package specification
elsif Scope (Current_Scope) /= Standard_Standard
and then not Is_Child_Unit (Current_Scope)
and then No (Generic_Parent (Parent (L)))
then
-- ARM rule 13.1.1(11/3): usage names in aspect definitions are
-- resolved at the end of the immediately enclosing declaration
-- list (AI05-0183-1).
Resolve_Aspects;
elsif L /= Visible_Declarations (Parent (L))
or else Is_Empty_List (Private_Declarations (Parent (L)))
then
Adjust_Decl;
-- End of a package declaration
-- This is a freeze point because it is the end of a
-- compilation unit.
Freeze_All (First_Entity (Current_Scope), Decl);
Freeze_From := Last_Entity (Current_Scope);
-- At the end of the visible declarations the expressions in
-- aspects of all entities declared so far must be resolved.
-- The entities themselves might be frozen later, and the
-- generated pragmas and attribute definition clauses analyzed
-- in full at that point, but name resolution must take place
-- now.
-- In addition to being the proper semantics, this is mandatory
-- within generic units, because global name capture requires
-- those expressions to be analyzed, given that the generated
-- pragmas do not appear in the original generic tree.
elsif Serious_Errors_Detected = 0 then
Resolve_Aspects;
end if;
-- If next node is a body then freeze all types before the body.
-- An exception occurs for some expander-generated bodies. If these
-- are generated at places where in general language rules would not
-- allow a freeze point, then we assume that the expander has
-- explicitly checked that all required types are properly frozen,
-- and we do not cause general freezing here. This special circuit
-- is used when the encountered body is marked as having already
-- been analyzed.
-- In all other cases (bodies that come from source, and expander
-- generated bodies that have not been analyzed yet), freeze all
-- types now. Note that in the latter case, the expander must take
-- care to attach the bodies at a proper place in the tree so as to
-- not cause unwanted freezing at that point.
-- It is also necessary to check for a case where both an expression
-- function is used and the current scope depends on an incomplete
-- private type from a library unit, otherwise premature freezing of
-- the private type will occur.
elsif not Analyzed (Next_Decl) and then Is_Body (Next_Decl)
and then ((Nkind (Next_Decl) /= N_Subprogram_Body
or else not Was_Expression_Function (Next_Decl))
or else (not Is_Ignored_Ghost_Entity (Current_Scope)
and then not Contains_Lib_Incomplete_Type
(Current_Scope)))
then
-- When a controlled type is frozen, the expander generates stream
-- and controlled-type support routines. If the freeze is caused
-- by the stand-alone body of Initialize, Adjust, or Finalize, the
-- expander will end up using the wrong version of these routines,
-- as the body has not been processed yet. To remedy this, detect
-- a late controlled primitive and create a proper spec for it.
-- This ensures that the primitive will override its inherited
-- counterpart before the freeze takes place.
-- If the declaration we just processed is a body, do not attempt
-- to examine Next_Decl as the late primitive idiom can only apply
-- to the first encountered body.
-- ??? A cleaner approach may be possible and/or this solution
-- could be extended to general-purpose late primitives.
if Present (Ctrl_Typ) then
-- No need to continue searching for late body overriding if
-- the controlled type is already frozen.
if Is_Frozen (Ctrl_Typ) then
Ctrl_Typ := Empty;
elsif Nkind (Next_Decl) = N_Subprogram_Body then
Handle_Late_Controlled_Primitive (Next_Decl);
end if;
end if;
Adjust_Decl;
-- The generated body of an expression function does not freeze,
-- unless it is a completion, in which case only the expression
-- itself freezes. This is handled when the body itself is
-- analyzed (see Freeze_Expr_Types, sem_ch6.adb).
Freeze_All (Freeze_From, Decl);
Freeze_From := Last_Entity (Current_Scope);
end if;
Decl := Next_Decl;
end loop;
-- Post-freezing actions
if Present (L) then
Context := Parent (L);
-- Certain contract annotations have forward visibility semantics and
-- must be analyzed after all declarative items have been processed.
-- This timing ensures that entities referenced by such contracts are
-- visible.
-- Analyze the contract of an immediately enclosing package spec or
-- body first because other contracts may depend on its information.
if Nkind (Context) = N_Package_Body then
Analyze_Package_Body_Contract (Defining_Entity (Context));
elsif Nkind (Context) = N_Package_Specification then
Analyze_Package_Contract (Defining_Entity (Context));
end if;
-- Analyze the contracts of various constructs in the declarative
-- list.
Analyze_Contracts (L);
if Nkind (Context) = N_Package_Body then
-- Ensure that all abstract states and objects declared in the
-- state space of a package body are utilized as constituents.
Check_Unused_Body_States (Defining_Entity (Context));
-- State refinements are visible up to the end of the package body
-- declarations. Hide the state refinements from visibility to
-- restore the original state conditions.
Remove_Visible_Refinements (Corresponding_Spec (Context));
Remove_Partial_Visible_Refinements (Corresponding_Spec (Context));
elsif Nkind (Context) = N_Package_Specification then
-- Partial state refinements are visible up to the end of the
-- package spec declarations. Hide the partial state refinements
-- from visibility to restore the original state conditions.
Remove_Partial_Visible_Refinements (Defining_Entity (Context));
end if;
-- Verify that all abstract states found in any package declared in
-- the input declarative list have proper refinements. The check is
-- performed only when the context denotes a block, entry, package,
-- protected, subprogram, or task body (SPARK RM 7.2.2(3)).
Check_State_Refinements (Context);
-- Create the subprogram bodies which verify the run-time semantics
-- of pragmas Default_Initial_Condition and [Type_]Invariant for all
-- types within the current declarative list. This ensures that all
-- assertion expressions are preanalyzed and resolved at the end of
-- the declarative part. Note that the resolution happens even when
-- freezing does not take place.
Build_Assertion_Bodies (L, Context);
end if;
end Analyze_Declarations;
-----------------------------------
-- Analyze_Full_Type_Declaration --
-----------------------------------
procedure Analyze_Full_Type_Declaration (N : Node_Id) is
Def : constant Node_Id := Type_Definition (N);
Def_Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
Prev : Entity_Id;
Is_Remote : constant Boolean :=
(Is_Remote_Types (Current_Scope)
or else Is_Remote_Call_Interface (Current_Scope))
and then not (In_Private_Part (Current_Scope)
or else In_Package_Body (Current_Scope));
procedure Check_Nonoverridable_Aspects;
-- Apply the rule in RM 13.1.1(18.4/4) on iterator aspects that cannot
-- be overridden, and can only be confirmed on derivation.
procedure Check_Ops_From_Incomplete_Type;
-- If there is a tagged incomplete partial view of the type, traverse
-- the primitives of the incomplete view and change the type of any
-- controlling formals and result to indicate the full view. The
-- primitives will be added to the full type's primitive operations
-- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
-- is called from Process_Incomplete_Dependents).
----------------------------------
-- Check_Nonoverridable_Aspects --
----------------------------------
procedure Check_Nonoverridable_Aspects is
function Get_Aspect_Spec
(Specs : List_Id;
Aspect_Name : Name_Id) return Node_Id;
-- Check whether a list of aspect specifications includes an entry
-- for a specific aspect. The list is either that of a partial or
-- a full view.
---------------------
-- Get_Aspect_Spec --
---------------------
function Get_Aspect_Spec
(Specs : List_Id;
Aspect_Name : Name_Id) return Node_Id
is
Spec : Node_Id;
begin
Spec := First (Specs);
while Present (Spec) loop
if Chars (Identifier (Spec)) = Aspect_Name then
return Spec;
end if;
Next (Spec);
end loop;
return Empty;
end Get_Aspect_Spec;
-- Local variables
Prev_Aspects : constant List_Id :=
Aspect_Specifications (Parent (Def_Id));
Par_Type : Entity_Id;
Prev_Aspect : Node_Id;
-- Start of processing for Check_Nonoverridable_Aspects
begin
-- Get parent type of derived type. Note that Prev is the entity in
-- the partial declaration, but its contents are now those of full
-- view, while Def_Id reflects the partial view.
if Is_Private_Type (Def_Id) then
Par_Type := Etype (Full_View (Def_Id));
else
Par_Type := Etype (Def_Id);
end if;
-- If there is an inherited Implicit_Dereference, verify that it is
-- made explicit in the partial view.
if Has_Discriminants (Base_Type (Par_Type))
and then Nkind (Parent (Prev)) = N_Full_Type_Declaration
and then Present (Discriminant_Specifications (Parent (Prev)))
and then Present (Get_Reference_Discriminant (Par_Type))
then
Prev_Aspect :=
Get_Aspect_Spec (Prev_Aspects, Name_Implicit_Dereference);
if No (Prev_Aspect)
and then Present
(Discriminant_Specifications
(Original_Node (Parent (Prev))))
then
Error_Msg_N
("type does not inherit implicit dereference", Prev);
else
-- If one of the views has the aspect specified, verify that it
-- is consistent with that of the parent.
declare
Cur_Discr : constant Entity_Id :=
Get_Reference_Discriminant (Prev);
Par_Discr : constant Entity_Id :=
Get_Reference_Discriminant (Par_Type);
begin
if Corresponding_Discriminant (Cur_Discr) /= Par_Discr then
Error_Msg_N
("aspect inconsistent with that of parent", N);
end if;
-- Check that specification in partial view matches the
-- inherited aspect. Compare names directly because aspect
-- expression may not be analyzed.
if Present (Prev_Aspect)
and then Nkind (Expression (Prev_Aspect)) = N_Identifier
and then Chars (Expression (Prev_Aspect)) /=
Chars (Cur_Discr)
then
Error_Msg_N
("aspect inconsistent with that of parent", N);
end if;
end;
end if;
end if;
-- What about other nonoverridable aspects???
end Check_Nonoverridable_Aspects;
------------------------------------
-- Check_Ops_From_Incomplete_Type --
------------------------------------
procedure Check_Ops_From_Incomplete_Type is
Elmt : Elmt_Id;
Formal : Entity_Id;
Op : Entity_Id;
begin
if Prev /= T
and then Ekind (Prev) = E_Incomplete_Type
and then Is_Tagged_Type (Prev)
and then Is_Tagged_Type (T)
and then Present (Primitive_Operations (Prev))
then
Elmt := First_Elmt (Primitive_Operations (Prev));
while Present (Elmt) loop
Op := Node (Elmt);
Formal := First_Formal (Op);
while Present (Formal) loop
if Etype (Formal) = Prev then
Set_Etype (Formal, T);
end if;
Next_Formal (Formal);
end loop;
if Etype (Op) = Prev then
Set_Etype (Op, T);
end if;
Next_Elmt (Elmt);
end loop;
end if;
end Check_Ops_From_Incomplete_Type;
-- Start of processing for Analyze_Full_Type_Declaration
begin
Prev := Find_Type_Name (N);
-- The full view, if present, now points to the current type. If there
-- is an incomplete partial view, set a link to it, to simplify the
-- retrieval of primitive operations of the type.
-- Ada 2005 (AI-50217): If the type was previously decorated when
-- imported through a LIMITED WITH clause, it appears as incomplete
-- but has no full view.
if Ekind (Prev) = E_Incomplete_Type
and then Present (Full_View (Prev))
then
T := Full_View (Prev);
Set_Incomplete_View (N, Prev);
else
T := Prev;
end if;
Set_Is_Pure (T, Is_Pure (Current_Scope));
-- We set the flag Is_First_Subtype here. It is needed to set the
-- corresponding flag for the Implicit class-wide-type created
-- during tagged types processing.
Set_Is_First_Subtype (T, True);
-- Only composite types other than array types are allowed to have
-- discriminants.
case Nkind (Def) is
-- For derived types, the rule will be checked once we've figured
-- out the parent type.
when N_Derived_Type_Definition =>
null;
-- For record types, discriminants are allowed.
when N_Record_Definition =>
null;
when others =>
if Present (Discriminant_Specifications (N)) then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier
(First (Discriminant_Specifications (N))));
end if;
end case;
-- Elaborate the type definition according to kind, and generate
-- subsidiary (implicit) subtypes where needed. We skip this if it was
-- already done (this happens during the reanalysis that follows a call
-- to the high level optimizer).
if not Analyzed (T) then
Set_Analyzed (T);
-- Set the SPARK mode from the current context
Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (T);
case Nkind (Def) is
when N_Access_To_Subprogram_Definition =>
Access_Subprogram_Declaration (T, Def);
-- If this is a remote access to subprogram, we must create the
-- equivalent fat pointer type, and related subprograms.
if Is_Remote then
Process_Remote_AST_Declaration (N);
end if;
-- Validate categorization rule against access type declaration
-- usually a violation in Pure unit, Shared_Passive unit.
Validate_Access_Type_Declaration (T, N);
-- If the type has contracts, we create the corresponding
-- wrapper at once, before analyzing the aspect specifications,
-- so that pre/postconditions can be handled directly on the
-- generated wrapper.
if Ada_Version >= Ada_2022
and then Present (Aspect_Specifications (N))
then
Build_Access_Subprogram_Wrapper (N);
end if;
when N_Access_To_Object_Definition =>
Access_Type_Declaration (T, Def);
-- Validate categorization rule against access type declaration
-- usually a violation in Pure unit, Shared_Passive unit.
Validate_Access_Type_Declaration (T, N);
-- If we are in a Remote_Call_Interface package and define a
-- RACW, then calling stubs and specific stream attributes
-- must be added.
if Is_Remote
and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
then
Add_RACW_Features (Def_Id);
end if;
when N_Array_Type_Definition =>
Array_Type_Declaration (T, Def);
when N_Derived_Type_Definition =>
Derived_Type_Declaration (T, N, T /= Def_Id);
-- Inherit predicates from parent, and protect against illegal
-- derivations.
if Is_Type (T) and then Has_Predicates (T) then
Set_Has_Predicates (Def_Id);
end if;
-- Save the scenario for examination by the ABE Processing
-- phase.
Record_Elaboration_Scenario (N);
when N_Enumeration_Type_Definition =>
Enumeration_Type_Declaration (T, Def);
when N_Floating_Point_Definition =>
Floating_Point_Type_Declaration (T, Def);
when N_Decimal_Fixed_Point_Definition =>
Decimal_Fixed_Point_Type_Declaration (T, Def);
when N_Ordinary_Fixed_Point_Definition =>
Ordinary_Fixed_Point_Type_Declaration (T, Def);
when N_Signed_Integer_Type_Definition =>
Signed_Integer_Type_Declaration (T, Def);
when N_Modular_Type_Definition =>
Modular_Type_Declaration (T, Def);
when N_Record_Definition =>
Record_Type_Declaration (T, N, Prev);
-- If declaration has a parse error, nothing to elaborate.
when N_Error =>
null;
when others =>
raise Program_Error;
end case;
end if;
if Etype (T) = Any_Type then
return;
end if;
-- Set the primitives list of the full type and its base type when
-- needed. T may be E_Void in cases of earlier errors, and in that
-- case we bypass this.
if Ekind (T) /= E_Void then
if not Present (Direct_Primitive_Operations (T)) then
if Etype (T) = T then
Set_Direct_Primitive_Operations (T, New_Elmt_List);
-- If Etype of T is the base type (as opposed to a parent type)
-- and already has an associated list of primitive operations,
-- then set T's primitive list to the base type's list. Otherwise,
-- create a new empty primitives list and share the list between
-- T and its base type. The lists need to be shared in common.
elsif Etype (T) = Base_Type (T) then
if not Present (Direct_Primitive_Operations (Base_Type (T)))
then
Set_Direct_Primitive_Operations
(Base_Type (T), New_Elmt_List);
end if;
Set_Direct_Primitive_Operations
(T, Direct_Primitive_Operations (Base_Type (T)));
-- Case where the Etype is a parent type, so we need a new
-- primitives list for T.
else
Set_Direct_Primitive_Operations (T, New_Elmt_List);
end if;
-- If T already has a Direct_Primitive_Operations list but its
-- base type doesn't then set the base type's list to T's list.
elsif not Present (Direct_Primitive_Operations (Base_Type (T))) then
Set_Direct_Primitive_Operations
(Base_Type (T), Direct_Primitive_Operations (T));
end if;
end if;
-- Some common processing for all types
Set_Depends_On_Private (T, Has_Private_Component (T));
Check_Ops_From_Incomplete_Type;
-- Both the declared entity, and its anonymous base type if one was
-- created, need freeze nodes allocated.
declare
B : constant Entity_Id := Base_Type (T);
begin
-- In the case where the base type differs from the first subtype, we
-- pre-allocate a freeze node, and set the proper link to the first
-- subtype. Freeze_Entity will use this preallocated freeze node when
-- it freezes the entity.
-- This does not apply if the base type is a generic type, whose
-- declaration is independent of the current derived definition.
if B /= T and then not Is_Generic_Type (B) then
Ensure_Freeze_Node (B);
Set_First_Subtype_Link (Freeze_Node (B), T);
end if;
-- A type that is imported through a limited_with clause cannot
-- generate any code, and thus need not be frozen. However, an access
-- type with an imported designated type needs a finalization list,
-- which may be referenced in some other package that has non-limited
-- visibility on the designated type. Thus we must create the
-- finalization list at the point the access type is frozen, to
-- prevent unsatisfied references at link time.
if not From_Limited_With (T) or else Is_Access_Type (T) then
Set_Has_Delayed_Freeze (T);
end if;
end;
-- Case where T is the full declaration of some private type which has
-- been swapped in Defining_Identifier (N).
if T /= Def_Id and then Is_Private_Type (Def_Id) then
Process_Full_View (N, T, Def_Id);
-- Record the reference. The form of this is a little strange, since
-- the full declaration has been swapped in. So the first parameter
-- here represents the entity to which a reference is made which is
-- the "real" entity, i.e. the one swapped in, and the second
-- parameter provides the reference location.
-- Also, we want to kill Has_Pragma_Unreferenced temporarily here
-- since we don't want a complaint about the full type being an
-- unwanted reference to the private type
declare
B : constant Boolean := Has_Pragma_Unreferenced (T);
begin
Set_Has_Pragma_Unreferenced (T, False);
Generate_Reference (T, T, 'c');
Set_Has_Pragma_Unreferenced (T, B);
end;
Set_Completion_Referenced (Def_Id);
-- For completion of incomplete type, process incomplete dependents
-- and always mark the full type as referenced (it is the incomplete
-- type that we get for any real reference).
elsif Ekind (Prev) = E_Incomplete_Type then
Process_Incomplete_Dependents (N, T, Prev);
Generate_Reference (Prev, Def_Id, 'c');
Set_Completion_Referenced (Def_Id);
-- If not private type or incomplete type completion, this is a real
-- definition of a new entity, so record it.
else
Generate_Definition (Def_Id);
end if;
-- Propagate any pending access types whose finalization masters need to
-- be fully initialized from the partial to the full view. Guard against
-- an illegal full view that remains unanalyzed.
if Is_Type (Def_Id) and then Is_Incomplete_Or_Private_Type (Prev) then
Set_Pending_Access_Types (Def_Id, Pending_Access_Types (Prev));
end if;
if Chars (Scope (Def_Id)) = Name_System
and then Chars (Def_Id) = Name_Address
and then In_Predefined_Unit (N)
then
Set_Is_Descendant_Of_Address (Def_Id);
Set_Is_Descendant_Of_Address (Base_Type (Def_Id));
Set_Is_Descendant_Of_Address (Prev);
end if;
Set_Optimize_Alignment_Flags (Def_Id);
Check_Eliminated (Def_Id);
-- If the declaration is a completion and aspects are present, apply
-- them to the entity for the type which is currently the partial
-- view, but which is the one that will be frozen.
if Has_Aspects (N) then
-- In most cases the partial view is a private type, and both views
-- appear in different declarative parts. In the unusual case where
-- the partial view is incomplete, perform the analysis on the
-- full view, to prevent freezing anomalies with the corresponding
-- class-wide type, which otherwise might be frozen before the
-- dispatch table is built.
if Prev /= Def_Id
and then Ekind (Prev) /= E_Incomplete_Type
then
Analyze_Aspect_Specifications (N, Prev);
-- Normal case
else
Analyze_Aspect_Specifications (N, Def_Id);
end if;
end if;
if Is_Derived_Type (Prev)
and then Def_Id /= Prev
then
Check_Nonoverridable_Aspects;
end if;
-- Check for tagged type declaration at library level
if Is_Tagged_Type (T)
and then not Is_Library_Level_Entity (T)
then
Check_Restriction (No_Local_Tagged_Types, T);
end if;
end Analyze_Full_Type_Declaration;
----------------------------------
-- Analyze_Incomplete_Type_Decl --
----------------------------------
procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
F : constant Boolean := Is_Pure (Current_Scope);
T : Entity_Id;
begin
Generate_Definition (Defining_Identifier (N));
-- Process an incomplete declaration. The identifier must not have been
-- declared already in the scope. However, an incomplete declaration may
-- appear in the private part of a package, for a private type that has
-- already been declared.
-- In this case, the discriminants (if any) must match
T := Find_Type_Name (N);
Mutate_Ekind (T, E_Incomplete_Type);
Set_Etype (T, T);
Set_Is_First_Subtype (T);
Reinit_Size_Align (T);
-- Set the SPARK mode from the current context
Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (T);
-- Ada 2005 (AI-326): Minimum decoration to give support to tagged
-- incomplete types.
if Tagged_Present (N) then
Set_Is_Tagged_Type (T, True);
Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
Make_Class_Wide_Type (T);
end if;
-- Initialize the list of primitive operations to an empty list,
-- to cover tagged types as well as untagged types. For untagged
-- types this is used either to analyze the call as legal when
-- Core_Extensions_Allowed is True, or to issue a better error message
-- otherwise.
Set_Direct_Primitive_Operations (T, New_Elmt_List);
Set_Stored_Constraint (T, No_Elist);
if Present (Discriminant_Specifications (N)) then
Push_Scope (T);
Process_Discriminants (N);
End_Scope;
end if;
-- If the type has discriminants, nontrivial subtypes may be declared
-- before the full view of the type. The full views of those subtypes
-- will be built after the full view of the type.
Set_Private_Dependents (T, New_Elmt_List);
Set_Is_Pure (T, F);
end Analyze_Incomplete_Type_Decl;
-----------------------------------
-- Analyze_Interface_Declaration --
-----------------------------------
procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
CW : constant Entity_Id := Class_Wide_Type (T);
begin
Set_Is_Tagged_Type (T);
Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
Set_Is_Limited_Record (T, Limited_Present (Def)
or else Task_Present (Def)
or else Protected_Present (Def)
or else Synchronized_Present (Def));
-- Type is abstract if full declaration carries keyword, or if previous
-- partial view did.
Set_Is_Abstract_Type (T);
Set_Is_Interface (T);
-- Type is a limited interface if it includes the keyword limited, task,
-- protected, or synchronized.
Set_Is_Limited_Interface
(T, Limited_Present (Def)
or else Protected_Present (Def)
or else Synchronized_Present (Def)
or else Task_Present (Def));
Set_Interfaces (T, New_Elmt_List);
Set_Direct_Primitive_Operations (T, New_Elmt_List);
-- Complete the decoration of the class-wide entity if it was already
-- built (i.e. during the creation of the limited view)
if Present (CW) then
Set_Is_Interface (CW);
Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
end if;
-- Check runtime support for synchronized interfaces
if Is_Concurrent_Interface (T)
and then not RTE_Available (RE_Select_Specific_Data)
then
Error_Msg_CRT ("synchronized interfaces", T);
end if;
end Analyze_Interface_Declaration;
-----------------------------
-- Analyze_Itype_Reference --
-----------------------------
-- Nothing to do. This node is placed in the tree only for the benefit of
-- back end processing, and has no effect on the semantic processing.
procedure Analyze_Itype_Reference (N : Node_Id) is
begin
pragma Assert (Is_Itype (Itype (N)));
null;
end Analyze_Itype_Reference;
--------------------------------
-- Analyze_Number_Declaration --
--------------------------------
procedure Analyze_Number_Declaration (N : Node_Id) is
E : constant Node_Id := Expression (N);
Id : constant Entity_Id := Defining_Identifier (N);
Index : Interp_Index;
It : Interp;
T : Entity_Id;
begin
Generate_Definition (Id);
Enter_Name (Id);
-- This is an optimization of a common case of an integer literal
if Nkind (E) = N_Integer_Literal then
Set_Is_Static_Expression (E, True);
Set_Etype (E, Universal_Integer);
Set_Etype (Id, Universal_Integer);
Mutate_Ekind (Id, E_Named_Integer);
Set_Is_Frozen (Id, True);
Set_Debug_Info_Needed (Id);
return;
end if;
Set_Is_Pure (Id, Is_Pure (Current_Scope));
-- Process expression, replacing error by integer zero, to avoid
-- cascaded errors or aborts further along in the processing
-- Replace Error by integer zero, which seems least likely to cause
-- cascaded errors.
if E = Error then
Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
Set_Error_Posted (E);
end if;
Analyze (E);
-- Verify that the expression is static and numeric. If
-- the expression is overloaded, we apply the preference
-- rule that favors root numeric types.
if not Is_Overloaded (E) then
T := Etype (E);
if Has_Dynamic_Predicate_Aspect (T) then
Error_Msg_N
("subtype has dynamic predicate, "
& "not allowed in number declaration", N);
end if;
else
T := Any_Type;
Get_First_Interp (E, Index, It);
while Present (It.Typ) loop
if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ))
and then (Scope (Base_Type (It.Typ))) = Standard_Standard
then
if T = Any_Type then
T := It.Typ;
elsif Is_Universal_Numeric_Type (It.Typ) then
-- Choose universal interpretation over any other
T := It.Typ;
exit;
end if;
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
if Is_Integer_Type (T) then
Resolve (E, T);
Set_Etype (Id, Universal_Integer);
Mutate_Ekind (Id, E_Named_Integer);
elsif Is_Real_Type (T) then
-- Because the real value is converted to universal_real, this is a
-- legal context for a universal fixed expression.
if T = Universal_Fixed then
declare
Loc : constant Source_Ptr := Sloc (N);
Conv : constant Node_Id := Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (Universal_Real, Loc),
Expression => Relocate_Node (E));
begin
Rewrite (E, Conv);
Analyze (E);
end;
elsif T = Any_Fixed then
Error_Msg_N ("illegal context for mixed mode operation", E);
-- Expression is of the form : universal_fixed * integer. Try to
-- resolve as universal_real.
T := Universal_Real;
Set_Etype (E, T);
end if;
Resolve (E, T);
Set_Etype (Id, Universal_Real);
Mutate_Ekind (Id, E_Named_Real);
else
Wrong_Type (E, Any_Numeric);
Resolve (E, T);
Set_Etype (Id, T);
Mutate_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
return;
end if;
if Nkind (E) in N_Integer_Literal | N_Real_Literal then
Set_Etype (E, Etype (Id));
end if;
if not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used in number declaration!", E);
Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
Set_Etype (E, Any_Type);
end if;
Analyze_Dimension (N);
end Analyze_Number_Declaration;
--------------------------------
-- Analyze_Object_Declaration --
--------------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Analyze_Object_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Id : constant Entity_Id := Defining_Identifier (N);
Next_Decl : constant Node_Id := Next (N);
Act_T : Entity_Id;
T : Entity_Id;
E : Node_Id := Expression (N);
-- E is set to Expression (N) throughout this routine. When Expression
-- (N) is modified, E is changed accordingly.
procedure Check_Dynamic_Object (Typ : Entity_Id);
-- A library-level object with nonstatic discriminant constraints may
-- require dynamic allocation. The declaration is illegal if the
-- profile includes the restriction No_Implicit_Heap_Allocations.
procedure Check_For_Null_Excluding_Components
(Obj_Typ : Entity_Id;
Obj_Decl : Node_Id);
-- Verify that each null-excluding component of object declaration
-- Obj_Decl carrying type Obj_Typ has explicit initialization. Emit
-- a compile-time warning if this is not the case.
function Count_Tasks (T : Entity_Id) return Uint;
-- This function is called when a non-generic library level object of a
-- task type is declared. Its function is to count the static number of
-- tasks declared within the type (it is only called if Has_Task is set
-- for T). As a side effect, if an array of tasks with nonstatic bounds
-- or a variant record type is encountered, Check_Restriction is called
-- indicating the count is unknown.
function Delayed_Aspect_Present return Boolean;
-- If the declaration has an expression that is an aggregate, and it
-- has aspects that require delayed analysis, the resolution of the
-- aggregate must be deferred to the freeze point of the object. This
-- special processing was created for address clauses, but it must
-- also apply to address aspects. This must be done before the aspect
-- specifications are analyzed because we must handle the aggregate
-- before the analysis of the object declaration is complete.
-- Any other relevant delayed aspects on object declarations ???
--------------------------
-- Check_Dynamic_Object --
--------------------------
procedure Check_Dynamic_Object (Typ : Entity_Id) is
Comp : Entity_Id;
Obj_Type : Entity_Id;
begin
Obj_Type := Typ;
if Is_Private_Type (Obj_Type)
and then Present (Full_View (Obj_Type))
then
Obj_Type := Full_View (Obj_Type);
end if;
if Known_Static_Esize (Obj_Type) then
return;
end if;
if Restriction_Active (No_Implicit_Heap_Allocations)
and then Expander_Active
and then Has_Discriminants (Obj_Type)
then
Comp := First_Component (Obj_Type);
while Present (Comp) loop
if Known_Static_Esize (Etype (Comp))
or else Size_Known_At_Compile_Time (Etype (Comp))
then
null;
elsif Is_Record_Type (Etype (Comp)) then
Check_Dynamic_Object (Etype (Comp));
elsif not Discriminated_Size (Comp)
and then Comes_From_Source (Comp)
then
Error_Msg_NE
("component& of non-static size will violate restriction "
& "No_Implicit_Heap_Allocation?", N, Comp);
end if;
Next_Component (Comp);
end loop;
end if;
end Check_Dynamic_Object;
-----------------------------------------
-- Check_For_Null_Excluding_Components --
-----------------------------------------
procedure Check_For_Null_Excluding_Components
(Obj_Typ : Entity_Id;
Obj_Decl : Node_Id)
is
procedure Check_Component
(Comp_Typ : Entity_Id;
Comp_Decl : Node_Id := Empty;
Array_Comp : Boolean := False);
-- Apply a compile-time null-exclusion check on a component denoted
-- by its declaration Comp_Decl and type Comp_Typ, and all of its
-- subcomponents (if any).
---------------------
-- Check_Component --
---------------------
procedure Check_Component
(Comp_Typ : Entity_Id;
Comp_Decl : Node_Id := Empty;
Array_Comp : Boolean := False)
is
Comp : Entity_Id;
T : Entity_Id;
begin
-- Do not consider internally-generated components or those that
-- are already initialized.
if Present (Comp_Decl)
and then (not Comes_From_Source (Comp_Decl)
or else Present (Expression (Comp_Decl)))
then
return;
end if;
if Is_Incomplete_Or_Private_Type (Comp_Typ)
and then Present (Full_View (Comp_Typ))
then
T := Full_View (Comp_Typ);
else
T := Comp_Typ;
end if;
-- Verify a component of a null-excluding access type
if Is_Access_Type (T)
and then Can_Never_Be_Null (T)
then
if Comp_Decl = Obj_Decl then
Null_Exclusion_Static_Checks
(N => Obj_Decl,
Comp => Empty,
Array_Comp => Array_Comp);
else
Null_Exclusion_Static_Checks
(N => Obj_Decl,
Comp => Comp_Decl,
Array_Comp => Array_Comp);
end if;
-- Check array components
elsif Is_Array_Type (T) then
-- There is no suitable component when the object is of an
-- array type. However, a namable component may appear at some
-- point during the recursive inspection, but not at the top
-- level. At the top level just indicate array component case.
if Comp_Decl = Obj_Decl then
Check_Component (Component_Type (T), Array_Comp => True);
else
Check_Component (Component_Type (T), Comp_Decl);
end if;
-- Verify all components of type T
-- Note: No checks are performed on types with discriminants due
-- to complexities involving variants. ???
elsif (Is_Concurrent_Type (T)
or else Is_Incomplete_Or_Private_Type (T)
or else Is_Record_Type (T))
and then not Has_Discriminants (T)
then
Comp := First_Component (T);
while Present (Comp) loop
Check_Component (Etype (Comp), Parent (Comp));
Next_Component (Comp);
end loop;
end if;
end Check_Component;
-- Start processing for Check_For_Null_Excluding_Components
begin
Check_Component (Obj_Typ, Obj_Decl);
end Check_For_Null_Excluding_Components;
-----------------
-- Count_Tasks --
-----------------
function Count_Tasks (T : Entity_Id) return Uint is
C : Entity_Id;
X : Node_Id;
V : Uint;
begin
if Is_Task_Type (T) then
return Uint_1;
elsif Is_Record_Type (T) then
if Has_Discriminants (T) then
Check_Restriction (Max_Tasks, N);
return Uint_0;
else
V := Uint_0;
C := First_Component (T);
while Present (C) loop
V := V + Count_Tasks (Etype (C));
Next_Component (C);
end loop;
return V;
end if;
elsif Is_Array_Type (T) then
X := First_Index (T);
V := Count_Tasks (Component_Type (T));
while Present (X) loop
C := Etype (X);
if not Is_OK_Static_Subtype (C) then
Check_Restriction (Max_Tasks, N);
return Uint_0;
else
V := V * (UI_Max (Uint_0,
Expr_Value (Type_High_Bound (C)) -
Expr_Value (Type_Low_Bound (C)) + Uint_1));
end if;
Next_Index (X);
end loop;
return V;
else
return Uint_0;
end if;
end Count_Tasks;
----------------------------
-- Delayed_Aspect_Present --
----------------------------
function Delayed_Aspect_Present return Boolean is
A : Node_Id;
A_Id : Aspect_Id;
begin
if Present (Aspect_Specifications (N)) then
A := First (Aspect_Specifications (N));
while Present (A) loop
A_Id := Get_Aspect_Id (Chars (Identifier (A)));
if A_Id = Aspect_Address then
-- Set flag on object entity, for later processing at
-- the freeze point.
Set_Has_Delayed_Aspects (Id);
return True;
end if;
Next (A);
end loop;
end if;
return False;
end Delayed_Aspect_Present;
-- Local variables
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Prev_Entity : Entity_Id := Empty;
Related_Id : Entity_Id;
-- Start of processing for Analyze_Object_Declaration
begin
-- There are three kinds of implicit types generated by an
-- object declaration:
-- 1. Those generated by the original Object Definition
-- 2. Those generated by the Expression
-- 3. Those used to constrain the Object Definition with the
-- expression constraints when the definition is unconstrained.
-- They must be generated in this order to avoid order of elaboration
-- issues. Thus the first step (after entering the name) is to analyze
-- the object definition.
if Constant_Present (N) then
Prev_Entity := Current_Entity_In_Scope (Id);
if Present (Prev_Entity)
and then
-- If the homograph is an implicit subprogram, it is overridden
-- by the current declaration.
((Is_Overloadable (Prev_Entity)
and then Is_Inherited_Operation (Prev_Entity))
-- The current object is a discriminal generated for an entry
-- family index. Even though the index is a constant, in this
-- particular context there is no true constant redeclaration.
-- Enter_Name will handle the visibility.
or else
(Is_Discriminal (Id)
and then Ekind (Discriminal_Link (Id)) =
E_Entry_Index_Parameter)
-- The current object is the renaming for a generic declared
-- within the instance.
or else
(Ekind (Prev_Entity) = E_Package
and then Nkind (Parent (Prev_Entity)) =
N_Package_Renaming_Declaration
and then not Comes_From_Source (Prev_Entity)
and then
Is_Generic_Instance (Renamed_Entity (Prev_Entity)))
-- The entity may be a homonym of a private component of the
-- enclosing protected object, for which we create a local
-- renaming declaration. The declaration is legal, even if
-- useless when it just captures that component.
or else
(Ekind (Scope (Current_Scope)) = E_Protected_Type
and then Nkind (Parent (Prev_Entity)) =
N_Object_Renaming_Declaration))
then
Prev_Entity := Empty;
end if;
end if;
if Present (Prev_Entity) then
-- The object declaration is Ghost when it completes a deferred Ghost
-- constant.
Mark_And_Set_Ghost_Completion (N, Prev_Entity);
Constant_Redeclaration (Id, N, T);
Generate_Reference (Prev_Entity, Id, 'c');
Set_Completion_Referenced (Id);
if Error_Posted (N) then
-- Type mismatch or illegal redeclaration; do not analyze
-- expression to avoid cascaded errors.
T := Find_Type_Of_Object (Object_Definition (N), N);
Set_Etype (Id, T);
Mutate_Ekind (Id, E_Variable);
goto Leave;
end if;
-- In the normal case, enter identifier at the start to catch premature
-- usage in the initialization expression.
else
Generate_Definition (Id);
Enter_Name (Id);
Mark_Coextensions (N, Object_Definition (N));
T := Find_Type_Of_Object (Object_Definition (N), N);
if Nkind (Object_Definition (N)) = N_Access_Definition
and then Present
(Access_To_Subprogram_Definition (Object_Definition (N)))
and then Protected_Present
(Access_To_Subprogram_Definition (Object_Definition (N)))
then
T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
end if;
if Error_Posted (Id) then
Set_Etype (Id, T);
Mutate_Ekind (Id, E_Variable);
goto Leave;
end if;
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
-- out some static checks.
if Ada_Version >= Ada_2005 then
-- In case of aggregates we must also take care of the correct
-- initialization of nested aggregates bug this is done at the
-- point of the analysis of the aggregate (see sem_aggr.adb) ???
if Can_Never_Be_Null (T) then
if Present (Expression (N))
and then Nkind (Expression (N)) = N_Aggregate
then
null;
elsif Comes_From_Source (Id) then
declare
Save_Typ : constant Entity_Id := Etype (Id);
begin
Set_Etype (Id, T); -- Temp. decoration for static checks
Null_Exclusion_Static_Checks (N);
Set_Etype (Id, Save_Typ);
end;
end if;
-- We might be dealing with an object of a composite type containing
-- null-excluding components without an aggregate, so we must verify
-- that such components have default initialization.
else
Check_For_Null_Excluding_Components (T, N);
end if;
end if;
-- Object is marked pure if it is in a pure scope
Set_Is_Pure (Id, Is_Pure (Current_Scope));
-- If deferred constant, make sure context is appropriate. We detect
-- a deferred constant as a constant declaration with no expression.
-- A deferred constant can appear in a package body if its completion
-- is by means of an interface pragma.
if Constant_Present (N) and then No (E) then
-- A deferred constant may appear in the declarative part of the
-- following constructs:
-- blocks
-- entry bodies
-- extended return statements
-- package specs
-- package bodies
-- subprogram bodies
-- task bodies
-- When declared inside a package spec, a deferred constant must be
-- completed by a full constant declaration or pragma Import. In all
-- other cases, the only proper completion is pragma Import. Extended
-- return statements are flagged as invalid contexts because they do
-- not have a declarative part and so cannot accommodate the pragma.
if Ekind (Current_Scope) = E_Return_Statement then
Error_Msg_N
("invalid context for deferred constant declaration (RM 7.4)",
N);
Error_Msg_N
("\declaration requires an initialization expression",
N);
Set_Constant_Present (N, False);
-- In Ada 83, deferred constant must be of private type
elsif not Is_Private_Type (T) then
if Ada_Version = Ada_83 and then Comes_From_Source (N) then
Error_Msg_N
("(Ada 83) deferred constant must be private type", N);
end if;
end if;
-- If not a deferred constant, then the object declaration freezes
-- its type, unless the object is of an anonymous type and has delayed
-- aspects. In that case the type is frozen when the object itself is.
else
Check_Fully_Declared (T, N);
if Has_Delayed_Aspects (Id)
and then Is_Array_Type (T)
and then Is_Itype (T)
then
Set_Has_Delayed_Freeze (T);
else
Freeze_Before (N, T);
end if;
end if;
-- If the object was created by a constrained array definition, then
-- set the link in both the anonymous base type and anonymous subtype
-- that are built to represent the array type to point to the object.
if Nkind (Object_Definition (Declaration_Node (Id))) =
N_Constrained_Array_Definition
then
Set_Related_Array_Object (T, Id);
Set_Related_Array_Object (Base_Type (T), Id);
end if;
-- Check for protected objects not at library level
if Has_Protected (T) and then not Is_Library_Level_Entity (Id) then
Check_Restriction (No_Local_Protected_Objects, Id);
end if;
-- Check for violation of No_Local_Timing_Events
if Has_Timing_Event (T) and then not Is_Library_Level_Entity (Id) then
Check_Restriction (No_Local_Timing_Events, Id);
end if;
-- The actual subtype of the object is the nominal subtype, unless
-- the nominal one is unconstrained and obtained from the expression.
Act_T := T;
if Is_Library_Level_Entity (Id) then
Check_Dynamic_Object (T);
end if;
-- Process initialization expression if present and not in error
if Present (E) and then E /= Error then
-- Generate an error in case of CPP class-wide object initialization.
-- Required because otherwise the expansion of the class-wide
-- assignment would try to use 'size to initialize the object
-- (primitive that is not available in CPP tagged types).
if Is_Class_Wide_Type (Act_T)
and then
(Is_CPP_Class (Root_Type (Etype (Act_T)))
or else
(Present (Full_View (Root_Type (Etype (Act_T))))
and then
Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
then
Error_Msg_N
("predefined assignment not available for 'C'P'P tagged types",
E);
end if;
Mark_Coextensions (N, E);
Analyze (E);
-- In case of errors detected in the analysis of the expression,
-- decorate it with the expected type to avoid cascaded errors.
if No (Etype (E)) then
Set_Etype (E, T);
end if;
-- If an initialization expression is present, then we set the
-- Is_True_Constant flag. It will be reset if this is a variable
-- and it is indeed modified.
Set_Is_True_Constant (Id, True);
-- If we are analyzing a constant declaration, set its completion
-- flag after analyzing and resolving the expression.
if Constant_Present (N) then
Set_Has_Completion (Id);
end if;
-- Set type and resolve (type may be overridden later on). Note:
-- Ekind (Id) must still be E_Void at this point so that incorrect
-- early usage within E is properly diagnosed.
Set_Etype (Id, T);
-- If the expression is an aggregate we must look ahead to detect
-- the possible presence of an address clause, and defer resolution
-- and expansion of the aggregate to the freeze point of the entity.
-- This is not always legal because the aggregate may contain other
-- references that need freezing, e.g. references to other entities
-- with address clauses. In any case, when compiling with -gnatI the
-- presence of the address clause must be ignored.
if Comes_From_Source (N)
and then Expander_Active
and then Nkind (E) = N_Aggregate
and then
((Present (Following_Address_Clause (N))
and then not Ignore_Rep_Clauses)
or else Delayed_Aspect_Present)
then
Set_Etype (E, T);
-- If the aggregate is limited it will be built in place, and its
-- expansion is deferred until the object declaration is expanded.
-- This is also required when generating C code to ensure that an
-- object with an alignment or address clause can be initialized
-- by means of component by component assignments.
if Is_Limited_Type (T) or else Modify_Tree_For_C then
Set_Expansion_Delayed (E);
end if;
else
-- If the expression is a formal that is a "subprogram pointer"
-- this is illegal in accessibility terms (see RM 3.10.2 (13.1/2)
-- and AARM 3.10.2 (13.b/2)). Add an explicit conversion to force
-- the corresponding check, as is done for assignments.
if Is_Entity_Name (E)
and then Present (Entity (E))
and then Is_Formal (Entity (E))
and then
Ekind (Etype (Entity (E))) = E_Anonymous_Access_Subprogram_Type
and then Ekind (T) /= E_Anonymous_Access_Subprogram_Type
then
Rewrite (E, Convert_To (T, Relocate_Node (E)));
end if;
Resolve (E, T);
end if;
-- No further action needed if E is a call to an inlined function
-- which returns an unconstrained type and it has been expanded into
-- a procedure call. In that case N has been replaced by an object
-- declaration without initializing expression and it has been
-- analyzed (see Expand_Inlined_Call).
if Back_End_Inlining
and then Expander_Active
and then Nkind (E) = N_Function_Call
and then Nkind (Name (E)) in N_Has_Entity
and then Is_Inlined (Entity (Name (E)))
and then not Is_Constrained (Etype (E))
and then Analyzed (N)
and then No (Expression (N))
then
goto Leave;
end if;
-- If E is null and has been replaced by an N_Raise_Constraint_Error
-- node (which was marked already-analyzed), we need to set the type
-- to something else than Universal_Access to keep gigi happy.
if Etype (E) = Universal_Access then
Set_Etype (E, T);
end if;
-- If the object is an access to variable, the initialization
-- expression cannot be an access to constant.
if Is_Access_Type (T)
and then not Is_Access_Constant (T)
and then Is_Access_Type (Etype (E))
and then Is_Access_Constant (Etype (E))
then
Error_Msg_N
("access to variable cannot be initialized with an "
& "access-to-constant expression", E);
end if;
if not Assignment_OK (N) then
Check_Initialization (T, E);
end if;
Check_Unset_Reference (E);
-- If this is a variable, then set current value. If this is a
-- declared constant of a scalar type with a static expression,
-- indicate that it is always valid.
if not Constant_Present (N) then
if Compile_Time_Known_Value (E) then
Set_Current_Value (Id, E);
end if;
elsif Is_Scalar_Type (T) and then Is_OK_Static_Expression (E) then
Set_Is_Known_Valid (Id);
-- If it is a constant initialized with a valid nonstatic entity,
-- the constant is known valid as well, and can inherit the subtype
-- of the entity if it is a subtype of the given type. This info
-- is preserved on the actual subtype of the constant.
elsif Is_Scalar_Type (T)
and then Is_Entity_Name (E)
and then Is_Known_Valid (Entity (E))
and then In_Subrange_Of (Etype (Entity (E)), T)
then
Set_Is_Known_Valid (Id);
Mutate_Ekind (Id, E_Constant);
Set_Actual_Subtype (Id, Etype (Entity (E)));
end if;
-- Deal with setting of null flags
if Is_Access_Type (T) then
if Known_Non_Null (E) then
Set_Is_Known_Non_Null (Id, True);
elsif Known_Null (E) and then not Can_Never_Be_Null (Id) then
Set_Is_Known_Null (Id, True);
end if;
end if;
-- Check incorrect use of dynamically tagged expressions
if Is_Tagged_Type (T) then
Check_Dynamically_Tagged_Expression
(Expr => E,
Typ => T,
Related_Nod => N);
end if;
Apply_Scalar_Range_Check (E, T);
Apply_Static_Length_Check (E, T);
-- A formal parameter of a specific tagged type whose related
-- subprogram is subject to pragma Extensions_Visible with value
-- "False" cannot be implicitly converted to a class-wide type by
-- means of an initialization expression (SPARK RM 6.1.7(3)). Do
-- not consider internally generated expressions.
if Is_Class_Wide_Type (T)
and then Comes_From_Source (E)
and then Is_EVF_Expression (E)
then
Error_Msg_N
("formal parameter cannot be implicitly converted to "
& "class-wide type when Extensions_Visible is False", E);
end if;
end if;
-- If the No_Streams restriction is set, check that the type of the
-- object is not, and does not contain, any subtype derived from
-- Ada.Streams.Root_Stream_Type. Note that we guard the call to
-- Has_Stream just for efficiency reasons. There is no point in
-- spending time on a Has_Stream check if the restriction is not set.
if Restriction_Check_Required (No_Streams) then
if Has_Stream (T) then
Check_Restriction (No_Streams, N);
end if;
end if;
-- Deal with predicate check before we start to do major rewriting. It
-- is OK to initialize and then check the initialized value, since the
-- object goes out of scope if we get a predicate failure. Note that we
-- do this in the analyzer and not the expander because the analyzer
-- does some substantial rewriting in some cases.
-- We need a predicate check if the type has predicates that are not
-- ignored, and if either there is an initializing expression, or for
-- default initialization when we have at least one case of an explicit
-- default initial value (including via a Default_Value or
-- Default_Component_Value aspect, see AI12-0301) and then this is not
-- an internal declaration whose initialization comes later (as for an
-- aggregate expansion) or a deferred constant.
-- If expression is an aggregate it may be expanded into assignments
-- and the declaration itself is marked with No_Initialization, but
-- the predicate still applies.
if not Suppress_Assignment_Checks (N)
and then (Predicate_Enabled (T) or else Has_Static_Predicate (T))
and then
(not No_Initialization (N)
or else (Present (E) and then Nkind (E) = N_Aggregate))
and then
(Present (E)
or else
Is_Partially_Initialized_Type (T, Include_Implicit => False))
and then not (Constant_Present (N) and then No (E))
then
-- If the type has a static predicate and the expression is known at
-- compile time, see if the expression satisfies the predicate.
-- In the case of a static expression, this must be done even if
-- the predicate is not enabled (as per static expression rules).
if Present (E) then
Check_Expression_Against_Static_Predicate (E, T);
end if;
-- Do not perform further predicate-related checks unless
-- predicates are enabled for the subtype.
if not Predicate_Enabled (T) then
null;
-- If the type is a null record and there is no explicit initial
-- expression, no predicate check applies.
elsif No (E) and then Is_Null_Record_Type (T) then
null;
-- Do not generate a predicate check if the initialization expression
-- is a type conversion whose target subtype statically matches the
-- object's subtype because the conversion has been subjected to the
-- same check. This is a small optimization which avoids redundant
-- checks.
elsif Present (E)
and then Nkind (E) in N_Type_Conversion
and then Subtypes_Statically_Match (Etype (Subtype_Mark (E)), T)
then
null;
else
-- The check must be inserted after the expanded aggregate
-- expansion code, if any.
declare
Check : constant Node_Id :=
Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc));
begin
if No (Next_Decl) then
Append_To (List_Containing (N), Check);
else
Insert_Before (Next_Decl, Check);
end if;
end;
end if;
end if;
-- Case of unconstrained type
if not Is_Definite_Subtype (T) then
-- Nothing to do in deferred constant case
if Constant_Present (N) and then No (E) then
null;
-- Case of no initialization present
elsif No (E) then
if No_Initialization (N) then
null;
elsif Is_Class_Wide_Type (T) then
Error_Msg_N
("initialization required in class-wide declaration", N);
else
Error_Msg_N
("unconstrained subtype not allowed (need initialization)",
Object_Definition (N));
if Is_Record_Type (T) and then Has_Discriminants (T) then
Error_Msg_N
("\provide initial value or explicit discriminant values",
Object_Definition (N));
Error_Msg_NE
("\or give default discriminant values for type&",
Object_Definition (N), T);
elsif Is_Array_Type (T) then
Error_Msg_N
("\provide initial value or explicit array bounds",
Object_Definition (N));
end if;
end if;
-- Case of initialization present but in error. Set initial
-- expression as absent (but do not make above complaints).
elsif E = Error then
Set_Expression (N, Empty);
E := Empty;
-- Case of initialization present
else
-- Unconstrained variables not allowed in Ada 83
if Ada_Version = Ada_83
and then not Constant_Present (N)
and then Comes_From_Source (Object_Definition (N))
then
Error_Msg_N
("(Ada 83) unconstrained variable not allowed",
Object_Definition (N));
end if;
-- Now we constrain the variable from the initializing expression
-- If the expression is an aggregate, it has been expanded into
-- individual assignments. Retrieve the actual type from the
-- expanded construct.
if Is_Array_Type (T)
and then No_Initialization (N)
and then Nkind (Original_Node (E)) = N_Aggregate
then
Act_T := Etype (E);
-- In case of class-wide interface object declarations we delay
-- the generation of the equivalent record type declarations until
-- its expansion because there are cases in they are not required.
elsif Is_Interface (T) then
null;
-- If the type is an unchecked union, no subtype can be built from
-- the expression. Rewrite declaration as a renaming, which the
-- back-end can handle properly. This is a rather unusual case,
-- because most unchecked_union declarations have default values
-- for discriminants and are thus not indefinite.
elsif Is_Unchecked_Union (T) then
if Constant_Present (N) or else Nkind (E) = N_Function_Call then
Mutate_Ekind (Id, E_Constant);
else
Mutate_Ekind (Id, E_Variable);
end if;
-- If the expression is an aggregate it contains the required
-- discriminant values but it has not been resolved yet, so do
-- it now, and treat it as the initial expression of an object
-- declaration, rather than a renaming.
if Nkind (E) = N_Aggregate then
Analyze_And_Resolve (E, T);
else
Rewrite (N,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Id,
Subtype_Mark => New_Occurrence_Of (T, Loc),
Name => E));
Set_Renamed_Object (Id, E);
Freeze_Before (N, T);
Set_Is_Frozen (Id);
goto Leave;
end if;
else
-- Ensure that the generated subtype has a unique external name
-- when the related object is public. This guarantees that the
-- subtype and its bounds will not be affected by switches or
-- pragmas that may offset the internal counter due to extra
-- generated code.
if Is_Public (Id) then
Related_Id := Id;
else
Related_Id := Empty;
end if;
-- If the object has an unconstrained array subtype with fixed
-- lower bound, then sliding to that bound may be needed.
if Is_Fixed_Lower_Bound_Array_Subtype (T) then
Expand_Sliding_Conversion (E, T);
end if;
if In_Spec_Expression and then In_Declare_Expr > 0 then
-- It is too early to be doing expansion-ish things,
-- so exit early. But we have to set Ekind (Id) now so
-- that subsequent uses of this entity are not rejected
-- via the same mechanism that (correctly) rejects
-- "X : Integer := X;".
if Constant_Present (N) then
Mutate_Ekind (Id, E_Constant);
Set_Is_True_Constant (Id);
else
Mutate_Ekind (Id, E_Variable);
if Present (E) then
Set_Has_Initial_Value (Id);
end if;
end if;
goto Leave;
end if;
Expand_Subtype_From_Expr
(N => N,
Unc_Type => T,
Subtype_Indic => Object_Definition (N),
Exp => E,
Related_Id => Related_Id);
Act_T := Find_Type_Of_Object (Object_Definition (N), N);
end if;
if Act_T /= T then
declare
Full_View_Present : constant Boolean :=
Is_Private_Type (Act_T)
and then Present (Full_View (Act_T));
-- Propagate attributes to full view when needed
begin
Set_Is_Constr_Subt_For_U_Nominal (Act_T);
if Full_View_Present then
Set_Is_Constr_Subt_For_U_Nominal (Full_View (Act_T));
end if;
if Aliased_Present (N) then
Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
if Full_View_Present then
Set_Is_Constr_Subt_For_UN_Aliased (Full_View (Act_T));
end if;
end if;
Freeze_Before (N, Act_T);
end;
end if;
Freeze_Before (N, T);
end if;
elsif Is_Array_Type (T)
and then No_Initialization (N)
and then (Nkind (Original_Node (E)) = N_Aggregate
or else (Nkind (Original_Node (E)) = N_Qualified_Expression
and then Nkind (Original_Node (Expression
(Original_Node (E)))) = N_Aggregate))
then
if not Is_Entity_Name (Object_Definition (N)) then
Act_T := Etype (E);
Check_Compile_Time_Size (Act_T);
end if;
-- When the given object definition and the aggregate are specified
-- independently, and their lengths might differ do a length check.
-- This cannot happen if the aggregate is of the form (others =>...)
if Nkind (E) = N_Raise_Constraint_Error then
-- Aggregate is statically illegal. Place back in declaration
Set_Expression (N, E);
Set_No_Initialization (N, False);
elsif T = Etype (E) then
null;
elsif Nkind (E) = N_Aggregate
and then Present (Component_Associations (E))
and then Present (Choice_List (First (Component_Associations (E))))
and then
Nkind (First (Choice_List (First (Component_Associations (E))))) =
N_Others_Choice
then
null;
else
Apply_Length_Check (E, T);
end if;
-- When possible, build the default subtype
elsif Build_Default_Subtype_OK (T) then
if No (E) then
Act_T := Build_Default_Subtype (T, N);
else
-- Ada 2005: A limited object may be initialized by means of an
-- aggregate. If the type has default discriminants it has an
-- unconstrained nominal type, Its actual subtype will be obtained
-- from the aggregate, and not from the default discriminants.
Act_T := Etype (E);
end if;
Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
elsif Nkind (E) = N_Function_Call
and then Constant_Present (N)
and then Has_Unconstrained_Elements (Etype (E))
then
-- The back-end has problems with constants of a discriminated type
-- with defaults, if the initial value is a function call. We
-- generate an intermediate temporary that will receive a reference
-- to the result of the call. The initialization expression then
-- becomes a dereference of that temporary.
Remove_Side_Effects (E);
-- If this is a constant declaration of an unconstrained type and
-- the initialization is an aggregate, we can use the subtype of the
-- aggregate for the declared entity because it is immutable.
elsif not Is_Constrained (T)
and then Has_Discriminants (T)
and then Constant_Present (N)
and then not Has_Unchecked_Union (T)
and then Nkind (E) = N_Aggregate
then
Act_T := Etype (E);
end if;
-- Check No_Wide_Characters restriction
Check_Wide_Character_Restriction (T, Object_Definition (N));
-- Indicate this is not set in source. Certainly true for constants, and
-- true for variables so far (will be reset for a variable if and when
-- we encounter a modification in the source).
Set_Never_Set_In_Source (Id);
-- Now establish the proper kind and type of the object
if Ekind (Id) = E_Void then
Reinit_Field_To_Zero (Id, F_Next_Inlined_Subprogram);
end if;
if Constant_Present (N) then
Mutate_Ekind (Id, E_Constant);
Set_Is_True_Constant (Id);
else
Mutate_Ekind (Id, E_Variable);
-- A variable is set as shared passive if it appears in a shared
-- passive package, and is at the outer level. This is not done for
-- entities generated during expansion, because those are always
-- manipulated locally.
if Is_Shared_Passive (Current_Scope)
and then Is_Library_Level_Entity (Id)
and then Comes_From_Source (Id)
then
Set_Is_Shared_Passive (Id);
Check_Shared_Var (Id, T, N);
end if;
-- Set Has_Initial_Value if initializing expression present. Note
-- that if there is no initializing expression, we leave the state
-- of this flag unchanged (usually it will be False, but notably in
-- the case of exception choice variables, it will already be true).
if Present (E) then
Set_Has_Initial_Value (Id);
end if;
end if;
-- Set the SPARK mode from the current context (may be overwritten later
-- with explicit pragma).
Set_SPARK_Pragma (Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Id);
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => Id,
Checks => True,
Warnings => True);
-- Initialize alignment and size and capture alignment setting
Reinit_Alignment (Id);
Reinit_Esize (Id);
Set_Optimize_Alignment_Flags (Id);
-- Deal with aliased case
if Aliased_Present (N) then
Set_Is_Aliased (Id);
-- AI12-001: All aliased objects are considered to be specified as
-- independently addressable (RM C.6(8.1/4)).
Set_Is_Independent (Id);
-- If the object is aliased and the type is unconstrained with
-- defaulted discriminants and there is no expression, then the
-- object is constrained by the defaults, so it is worthwhile
-- building the corresponding subtype.
-- Ada 2005 (AI-363): If the aliased object is discriminated and
-- unconstrained, then only establish an actual subtype if the
-- nominal subtype is indefinite. In definite cases the object is
-- unconstrained in Ada 2005.
if No (E)
and then Is_Record_Type (T)
and then not Is_Constrained (T)
and then Has_Discriminants (T)
and then (Ada_Version < Ada_2005
or else not Is_Definite_Subtype (T))
then
Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
end if;
end if;
-- Now we can set the type of the object
Set_Etype (Id, Act_T);
-- Non-constant object is marked to be treated as volatile if type is
-- volatile and we clear the Current_Value setting that may have been
-- set above. Doing so for constants isn't required and might interfere
-- with possible uses of the object as a static expression in contexts
-- incompatible with volatility (e.g. as a case-statement alternative).
if Ekind (Id) /= E_Constant and then Treat_As_Volatile (Etype (Id)) then
Set_Treat_As_Volatile (Id);
Set_Current_Value (Id, Empty);
end if;
-- Deal with controlled types
if Has_Controlled_Component (Etype (Id))
or else Is_Controlled (Etype (Id))
then
if not Is_Library_Level_Entity (Id) then
Check_Restriction (No_Nested_Finalization, N);
else
Validate_Controlled_Object (Id);
end if;
end if;
if Has_Task (Etype (Id)) then
Check_Restriction (No_Tasking, N);
-- Deal with counting max tasks
-- Nothing to do if inside a generic
if Inside_A_Generic then
null;
-- If library level entity, then count tasks
elsif Is_Library_Level_Entity (Id) then
Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
-- If not library level entity, then indicate we don't know max
-- tasks and also check task hierarchy restriction and blocking
-- operation (since starting a task is definitely blocking).
else
Check_Restriction (Max_Tasks, N);
Check_Restriction (No_Task_Hierarchy, N);
Check_Potentially_Blocking_Operation (N);
end if;
-- A rather specialized test. If we see two tasks being declared
-- of the same type in the same object declaration, and the task
-- has an entry with an address clause, we know that program error
-- will be raised at run time since we can't have two tasks with
-- entries at the same address.
if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
declare
E : Entity_Id;
begin
E := First_Entity (Etype (Id));
while Present (E) loop
if Ekind (E) = E_Entry
and then Present (Get_Attribute_Definition_Clause
(E, Attribute_Address))
then
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N
("more than one task with same entry address<<", N);
Error_Msg_N ("\Program_Error [<<", N);
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Duplicated_Entry_Address));
exit;
end if;
Next_Entity (E);
end loop;
end;
end if;
end if;
-- Some simple constant-propagation: if the expression is a constant
-- string initialized with a literal, share the literal. This avoids
-- a run-time copy.
if Present (E)
and then Is_Entity_Name (E)
and then Ekind (Entity (E)) = E_Constant
and then Base_Type (Etype (E)) = Standard_String
then
declare
Val : constant Node_Id := Constant_Value (Entity (E));
begin
if Present (Val) and then Nkind (Val) = N_String_Literal then
Rewrite (E, New_Copy (Val));
end if;
end;
end if;
if Present (Prev_Entity)
and then Is_Frozen (Prev_Entity)
and then not Error_Posted (Id)
then
Error_Msg_N ("full constant declaration appears too late", N);
end if;
Check_Eliminated (Id);
-- Deal with setting In_Private_Part flag if in private part
if Ekind (Scope (Id)) = E_Package
and then In_Private_Part (Scope (Id))
then
Set_In_Private_Part (Id);
end if;
<<Leave>>
-- Initialize the refined state of a variable here because this is a
-- common destination for legal and illegal object declarations.
if Ekind (Id) = E_Variable then
Set_Encapsulating_State (Id, Empty);
end if;
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
Analyze_Dimension (N);
-- Verify whether the object declaration introduces an illegal hidden
-- state within a package subject to a null abstract state.
if Ekind (Id) = E_Variable then
Check_No_Hidden_State (Id);
end if;
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Analyze_Object_Declaration;
---------------------------
-- Analyze_Others_Choice --
---------------------------
-- Nothing to do for the others choice node itself, the semantic analysis
-- of the others choice will occur as part of the processing of the parent
procedure Analyze_Others_Choice (N : Node_Id) is
pragma Warnings (Off, N);
begin
null;
end Analyze_Others_Choice;
-------------------------------------------
-- Analyze_Private_Extension_Declaration --
-------------------------------------------
procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
Indic : constant Node_Id := Subtype_Indication (N);
T : constant Entity_Id := Defining_Identifier (N);
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
Parent_Base : Entity_Id;
Parent_Type : Entity_Id;
begin
-- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
if Is_Non_Empty_List (Interface_List (N)) then
declare
Intf : Node_Id;
T : Entity_Id;
begin
Intf := First (Interface_List (N));
while Present (Intf) loop
T := Find_Type_Of_Subtype_Indic (Intf);
Diagnose_Interface (Intf, T);
Next (Intf);
end loop;
end;
end if;
Generate_Definition (T);
-- For other than Ada 2012, just enter the name in the current scope
if Ada_Version < Ada_2012 then
Enter_Name (T);
-- Ada 2012 (AI05-0162): Enter the name in the current scope handling
-- case of private type that completes an incomplete type.
else
declare
Prev : Entity_Id;
begin
Prev := Find_Type_Name (N);
pragma Assert (Prev = T
or else (Ekind (Prev) = E_Incomplete_Type
and then Present (Full_View (Prev))
and then Full_View (Prev) = T));
end;
end if;
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
Parent_Base := Base_Type (Parent_Type);
if Parent_Type = Any_Type or else Etype (Parent_Type) = Any_Type then
Mutate_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
goto Leave;
elsif not Is_Tagged_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must be a tagged type", Indic);
goto Leave;
elsif Ekind (Parent_Type) in E_Void | E_Incomplete_Type then
Error_Msg_N ("premature derivation of incomplete type", Indic);
goto Leave;
elsif Is_Concurrent_Type (Parent_Type) then
Error_Msg_N
("parent type of a private extension cannot be a synchronized "
& "tagged type (RM 3.9.1 (3/1))", N);
Set_Etype (T, Any_Type);
Mutate_Ekind (T, E_Limited_Private_Type);
Set_Private_Dependents (T, New_Elmt_List);
Set_Error_Posted (T);
goto Leave;
end if;
Check_Wide_Character_Restriction (Parent_Type, Indic);
-- Perhaps the parent type should be changed to the class-wide type's
-- specific type in this case to prevent cascading errors ???
if Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must not be a class-wide type", Indic);
goto Leave;
end if;
if (not Is_Package_Or_Generic_Package (Current_Scope)
and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
or else In_Private_Part (Current_Scope)
then
Error_Msg_N ("invalid context for private extension", N);
end if;
-- Set common attributes
Set_Is_Pure (T, Is_Pure (Current_Scope));
Set_Scope (T, Current_Scope);
Mutate_Ekind (T, E_Record_Type_With_Private);
Reinit_Size_Align (T);
Set_Default_SSO (T);
Set_No_Reordering (T, No_Component_Reordering);
Set_Etype (T, Parent_Base);
Propagate_Concurrent_Flags (T, Parent_Base);
Set_Convention (T, Convention (Parent_Type));
Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
Set_Is_First_Subtype (T);
Make_Class_Wide_Type (T);
-- Set the SPARK mode from the current context
Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (T);
if Unknown_Discriminants_Present (N) then
Set_Discriminant_Constraint (T, No_Elist);
end if;
Build_Derived_Record_Type (N, Parent_Type, T);
-- A private extension inherits the Default_Initial_Condition pragma
-- coming from any parent type within the derivation chain.
if Has_DIC (Parent_Type) then
Set_Has_Inherited_DIC (T);
end if;
-- A private extension inherits any class-wide invariants coming from a
-- parent type or an interface. Note that the invariant procedure of the
-- parent type should not be inherited because the private extension may
-- define invariants of its own.
if Has_Inherited_Invariants (Parent_Type)
or else Has_Inheritable_Invariants (Parent_Type)
then
Set_Has_Inherited_Invariants (T);
elsif Present (Interfaces (T)) then
Iface_Elmt := First_Elmt (Interfaces (T));
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
if Has_Inheritable_Invariants (Iface) then
Set_Has_Inherited_Invariants (T);
exit;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
-- Ada 2005 (AI-443): Synchronized private extension or a rewritten
-- synchronized formal derived type.
if Ada_Version >= Ada_2005 and then Synchronized_Present (N) then
Set_Is_Limited_Record (T);
-- Formal derived type case
if Is_Generic_Type (T) then
-- The parent must be a tagged limited type or a synchronized
-- interface.
if (not Is_Tagged_Type (Parent_Type)
or else not Is_Limited_Type (Parent_Type))
and then
(not Is_Interface (Parent_Type)
or else not Is_Synchronized_Interface (Parent_Type))
then
Error_Msg_NE
("parent type of & must be tagged limited or synchronized",
N, T);
end if;
-- The progenitors (if any) must be limited or synchronized
-- interfaces.
if Present (Interfaces (T)) then
Iface_Elmt := First_Elmt (Interfaces (T));
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
if not Is_Limited_Interface (Iface)
and then not Is_Synchronized_Interface (Iface)
then
Error_Msg_NE
("progenitor & must be limited or synchronized",
N, Iface);
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
-- Regular derived extension, the parent must be a limited or
-- synchronized interface.
else
if not Is_Interface (Parent_Type)
or else (not Is_Limited_Interface (Parent_Type)
and then not Is_Synchronized_Interface (Parent_Type))
then
Error_Msg_NE
("parent type of & must be limited interface", N, T);
end if;
end if;
-- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
-- extension with a synchronized parent must be explicitly declared
-- synchronized, because the full view will be a synchronized type.
-- This must be checked before the check for limited types below,
-- to ensure that types declared limited are not allowed to extend
-- synchronized interfaces.
elsif Is_Interface (Parent_Type)
and then Is_Synchronized_Interface (Parent_Type)
and then not Synchronized_Present (N)
then
Error_Msg_NE
("private extension of& must be explicitly synchronized",
N, Parent_Type);
elsif Limited_Present (N) then
Set_Is_Limited_Record (T);
if not Is_Limited_Type (Parent_Type)
and then
(not Is_Interface (Parent_Type)
or else not Is_Limited_Interface (Parent_Type))
then
Error_Msg_NE ("parent type& of limited extension must be limited",
N, Parent_Type);
end if;
end if;
-- Remember that its parent type has a private extension. Used to warn
-- on public primitives of the parent type defined after its private
-- extensions (see Check_Dispatching_Operation).
Set_Has_Private_Extension (Parent_Type);
<<Leave>>
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, T);
end if;
end Analyze_Private_Extension_Declaration;
---------------------------------
-- Analyze_Subtype_Declaration --
---------------------------------
procedure Analyze_Subtype_Declaration
(N : Node_Id;
Skip : Boolean := False)
is
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
begin
Generate_Definition (Id);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
Reinit_Size_Align (Id);
-- The following guard condition on Enter_Name is to handle cases where
-- the defining identifier has already been entered into the scope but
-- the declaration as a whole needs to be analyzed.
-- This case in particular happens for derived enumeration types. The
-- derived enumeration type is processed as an inserted enumeration type
-- declaration followed by a rewritten subtype declaration. The defining
-- identifier, however, is entered into the name scope very early in the
-- processing of the original type declaration and therefore needs to be
-- avoided here, when the created subtype declaration is analyzed. (See
-- Build_Derived_Types)
-- This also happens when the full view of a private type is derived
-- type with constraints. In this case the entity has been introduced
-- in the private declaration.
-- Finally this happens in some complex cases when validity checks are
-- enabled, where the same subtype declaration may be analyzed twice.
-- This can happen if the subtype is created by the preanalysis of
-- an attribute that gives the range of a loop statement, and the loop
-- itself appears within an if_statement that will be rewritten during
-- expansion.
if Skip
or else (Present (Etype (Id))
and then (Is_Private_Type (Etype (Id))
or else Is_Task_Type (Etype (Id))
or else Is_Rewrite_Substitution (N)))
then
null;
elsif Current_Entity (Id) = Id then
null;
else
Enter_Name (Id);
end if;
T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
-- Class-wide equivalent types of records with unknown discriminants
-- involve the generation of an itype which serves as the private view
-- of a constrained record subtype. In such cases the base type of the
-- current subtype we are processing is the private itype. Use the full
-- of the private itype when decorating various attributes.
if Is_Itype (T)
and then Is_Private_Type (T)
and then Present (Full_View (T))
then
T := Full_View (T);
end if;
-- Inherit common attributes
Set_Is_Volatile (Id, Is_Volatile (T));
Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
Set_Convention (Id, Convention (T));
-- If ancestor has predicates then so does the subtype, and in addition
-- we must delay the freeze to properly arrange predicate inheritance.
-- The Ancestor_Type test is really unpleasant, there seem to be cases
-- in which T = ID, so the above tests and assignments do nothing???
if Has_Predicates (T)
or else (Present (Ancestor_Subtype (T))
and then Has_Predicates (Ancestor_Subtype (T)))
then
Set_Has_Predicates (Id);
Set_Has_Delayed_Freeze (Id);
-- Generated subtypes inherit the predicate function from the parent
-- (no aspects to examine on the generated declaration).
if not Comes_From_Source (N) then
Mutate_Ekind (Id, Ekind (T));
if Present (Predicate_Function (Id)) then
null;
elsif Present (Predicate_Function (T)) then
Set_Predicate_Function (Id, Predicate_Function (T));
elsif Present (Ancestor_Subtype (T))
and then Present (Predicate_Function (Ancestor_Subtype (T)))
then
Set_Predicate_Function (Id,
Predicate_Function (Ancestor_Subtype (T)));
end if;
end if;
end if;
-- In the case where there is no constraint given in the subtype
-- indication, Process_Subtype just returns the Subtype_Mark, so its
-- semantic attributes must be established here.
if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
Set_Etype (Id, Base_Type (T));
case Ekind (T) is
when Array_Kind =>
Mutate_Ekind (Id, E_Array_Subtype);
Copy_Array_Subtype_Attributes (Id, T);
Set_Packed_Array_Impl_Type (Id, Packed_Array_Impl_Type (T));
when Decimal_Fixed_Point_Kind =>
Mutate_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
Set_Digits_Value (Id, Digits_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Scale_Value (Id, Scale_Value (T));
Set_Small_Value (Id, Small_Value (T));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Known_Valid (Id, Is_Known_Valid (T));
Copy_RM_Size (To => Id, From => T);
when Enumeration_Kind =>
Mutate_Ekind (Id, E_Enumeration_Subtype);
Set_First_Literal (Id, First_Literal (Base_Type (T)));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Character_Type (Id, Is_Character_Type (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Known_Valid (Id, Is_Known_Valid (T));
Copy_RM_Size (To => Id, From => T);
when Ordinary_Fixed_Point_Kind =>
Mutate_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Small_Value (Id, Small_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Known_Valid (Id, Is_Known_Valid (T));
Copy_RM_Size (To => Id, From => T);
when Float_Kind =>
Mutate_Ekind (Id, E_Floating_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Digits_Value (Id, Digits_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
-- If the floating point type has dimensions, these will be
-- inherited subsequently when Analyze_Dimensions is called.
when Signed_Integer_Kind =>
Mutate_Ekind (Id, E_Signed_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Known_Valid (Id, Is_Known_Valid (T));
Copy_RM_Size (To => Id, From => T);
when Modular_Integer_Kind =>
Mutate_Ekind (Id, E_Modular_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Known_Valid (Id, Is_Known_Valid (T));
Copy_RM_Size (To => Id, From => T);
when Class_Wide_Kind =>
Mutate_Ekind (Id, E_Class_Wide_Subtype);
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
Set_Cloned_Subtype (Id, T);
Set_Is_Tagged_Type (Id, True);
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Unknown_Discriminants
(Id, True);
Set_No_Tagged_Streams_Pragma
(Id, No_Tagged_Streams_Pragma (T));
if Ekind (T) = E_Class_Wide_Subtype then
Set_Equivalent_Type (Id, Equivalent_Type (T));
end if;
when E_Record_Subtype
| E_Record_Type
=>
Mutate_Ekind (Id, E_Record_Subtype);
-- Subtype declarations introduced for formal type parameters
-- in generic instantiations should inherit the Size value of
-- the type they rename.
if Present (Generic_Parent_Type (N)) then
Copy_RM_Size (To => Id, From => T);
end if;
if Ekind (T) = E_Record_Subtype
and then Present (Cloned_Subtype (T))
then
Set_Cloned_Subtype (Id, Cloned_Subtype (T));
else
Set_Cloned_Subtype (Id, T);
end if;
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Implicit_Dereference
(Id, Has_Implicit_Dereference (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
elsif Has_Unknown_Discriminants (Id) then
Set_Discriminant_Constraint (Id, No_Elist);
end if;
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id, True);
Set_No_Tagged_Streams_Pragma
(Id, No_Tagged_Streams_Pragma (T));
Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
Set_Direct_Primitive_Operations
(Id, Direct_Primitive_Operations (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
if Is_Interface (T) then
Set_Is_Interface (Id);
Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
end if;
end if;
when Private_Kind =>
Mutate_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Private_Dependents (Id, New_Elmt_List);
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Implicit_Dereference
(Id, Has_Implicit_Dereference (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
Set_Known_To_Have_Preelab_Init
(Id, Known_To_Have_Preelab_Init (T));
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id);
Set_No_Tagged_Streams_Pragma (Id,
No_Tagged_Streams_Pragma (T));
Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
Set_Direct_Primitive_Operations (Id,
Direct_Primitive_Operations (T));
end if;
-- In general the attributes of the subtype of a private type
-- are the attributes of the partial view of parent. However,
-- the full view may be a discriminated type, and the subtype
-- must share the discriminant constraint to generate correct
-- calls to initialization procedures.
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
elsif Present (Full_View (T))
and then Has_Discriminants (Full_View (T))
then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (Full_View (T)));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
-- This would seem semantically correct, but apparently
-- generates spurious errors about missing components ???
-- Set_Has_Discriminants (Id);
end if;
Prepare_Private_Subtype_Completion (Id, N);
-- If this is the subtype of a constrained private type with
-- discriminants that has got a full view and we also have
-- built a completion just above, show that the completion
-- is a clone of the full view to the back-end.
if Has_Discriminants (T)
and then not Has_Unknown_Discriminants (T)
and then not Is_Empty_Elmt_List (Discriminant_Constraint (T))
and then Present (Full_View (T))
and then Present (Full_View (Id))
then
Set_Cloned_Subtype (Full_View (Id), Full_View (T));
end if;
when Access_Kind =>
Mutate_Ekind (Id, E_Access_Subtype);
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Access_Constant
(Id, Is_Access_Constant (T));
Set_Directly_Designated_Type
(Id, Designated_Type (T));
Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
-- A Pure library_item must not contain the declaration of a
-- named access type, except within a subprogram, generic
-- subprogram, task unit, or protected unit, or if it has
-- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
if Comes_From_Source (Id)
and then In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
and then not No_Pool_Assigned (Id)
then
Error_Msg_N
("named access types not allowed in pure unit", N);
end if;
when Concurrent_Kind =>
Mutate_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Corresponding_Record_Type (Id,
Corresponding_Record_Type (T));
Set_First_Entity (Id, First_Entity (T));
Set_First_Private_Entity (Id, First_Private_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
Set_Last_Entity (Id, Last_Entity (T));
if Is_Tagged_Type (T) then
Set_No_Tagged_Streams_Pragma
(Id, No_Tagged_Streams_Pragma (T));
end if;
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
end if;
when Incomplete_Kind =>
if Ada_Version >= Ada_2005 then
-- In Ada 2005 an incomplete type can be explicitly tagged:
-- propagate indication. Note that we also have to include
-- subtypes for Ada 2012 extended use of incomplete types.
Mutate_Ekind (Id, E_Incomplete_Subtype);
Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
Set_Private_Dependents (Id, New_Elmt_List);
if Is_Tagged_Type (Id) then
Set_No_Tagged_Streams_Pragma
(Id, No_Tagged_Streams_Pragma (T));
end if;
-- For tagged types, or when prefixed-call syntax is allowed
-- for untagged types, initialize the list of primitive
-- operations to an empty list.
if Is_Tagged_Type (Id)
or else Core_Extensions_Allowed
then
Set_Direct_Primitive_Operations (Id, New_Elmt_List);
end if;
-- Ada 2005 (AI-412): Decorate an incomplete subtype of an
-- incomplete type visible through a limited with clause.
if From_Limited_With (T)
and then Present (Non_Limited_View (T))
then
Set_From_Limited_With (Id);
Set_Non_Limited_View (Id, Non_Limited_View (T));
-- Ada 2005 (AI-412): Add the regular incomplete subtype
-- to the private dependents of the original incomplete
-- type for future transformation.
else
Append_Elmt (Id, Private_Dependents (T));
end if;
-- If the subtype name denotes an incomplete type an error
-- was already reported by Process_Subtype.
else
Set_Etype (Id, Any_Type);
end if;
when others =>
raise Program_Error;
end case;
-- If there is no constraint in the subtype indication, the
-- declared entity inherits predicates from the parent.
Inherit_Predicate_Flags (Id, T);
end if;
if Etype (Id) = Any_Type then
goto Leave;
end if;
-- When prefixed calls are enabled for untagged types, the subtype
-- shares the primitive operations of its base type. Do this even
-- when Extensions_Allowed is False to issue better error messages.
Set_Direct_Primitive_Operations
(Id, Direct_Primitive_Operations (Base_Type (T)));
-- Some common processing on all types
Set_Size_Info (Id, T);
Set_First_Rep_Item (Id, First_Rep_Item (T));
-- If the parent type is a generic actual, so is the subtype. This may
-- happen in a nested instance. Why Comes_From_Source test???
if not Comes_From_Source (N) then
Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T));
end if;
-- If this is a subtype declaration for an actual in an instance,
-- inherit static and dynamic predicates if any.
-- If declaration has no aspect specifications, inherit predicate
-- info as well. Unclear how to handle the case of both specified
-- and inherited predicates ??? Other inherited aspects, such as
-- invariants, should be OK, but the combination with later pragmas
-- may also require special merging.
if Has_Predicates (T)
and then Present (Predicate_Function (T))
and then
((In_Instance and then not Comes_From_Source (N))
or else No (Aspect_Specifications (N)))
then
-- Inherit Subprograms_For_Type from the full view, if present
if Present (Full_View (T))
and then Present (Subprograms_For_Type (Full_View (T)))
then
Set_Subprograms_For_Type
(Id, Subprograms_For_Type (Full_View (T)));
else
Set_Subprograms_For_Type (Id, Subprograms_For_Type (T));
end if;
-- If the current declaration created both a private and a full view,
-- then propagate Predicate_Function to the latter as well.
if Present (Full_View (Id))
and then No (Predicate_Function (Full_View (Id)))
then
Set_Subprograms_For_Type
(Full_View (Id), Subprograms_For_Type (Id));
end if;
if Has_Static_Predicate (T) then
Set_Has_Static_Predicate (Id);
Set_Static_Discrete_Predicate (Id, Static_Discrete_Predicate (T));
end if;
end if;
-- If the base type is a scalar type, or else if there is no
-- constraint, the atomic flag is inherited by the subtype.
-- Ditto for the Independent aspect.
if Is_Scalar_Type (Id)
or else Is_Entity_Name (Subtype_Indication (N))
then
Set_Is_Atomic (Id, Is_Atomic (T));
Set_Is_Independent (Id, Is_Independent (T));
end if;
-- Remaining processing depends on characteristics of base type
T := Etype (Id);
Set_Is_Immediately_Visible (Id, True);
Set_Depends_On_Private (Id, Has_Private_Component (T));
Set_Is_Descendant_Of_Address (Id, Is_Descendant_Of_Address (T));
if Is_Interface (T) then
Set_Is_Interface (Id);
Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
end if;
if Present (Generic_Parent_Type (N))
and then
(Nkind (Parent (Generic_Parent_Type (N))) /=
N_Formal_Type_Declaration
or else Nkind (Formal_Type_Definition
(Parent (Generic_Parent_Type (N)))) /=
N_Formal_Private_Type_Definition)
then
if Is_Tagged_Type (Id) then
-- If this is a generic actual subtype for a synchronized type,
-- the primitive operations are those of the corresponding record
-- for which there is a separate subtype declaration.
if Is_Concurrent_Type (Id) then
null;
elsif Is_Class_Wide_Type (Id) then
Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
else
Derive_Subprograms (Generic_Parent_Type (N), Id, T);
end if;
elsif Scope (Etype (Id)) /= Standard_Standard then
Derive_Subprograms (Generic_Parent_Type (N), Id);
end if;
end if;
if Is_Private_Type (T) and then Present (Full_View (T)) then
Conditional_Delay (Id, Full_View (T));
-- The subtypes of components or subcomponents of protected types
-- do not need freeze nodes, which would otherwise appear in the
-- wrong scope (before the freeze node for the protected type). The
-- proper subtypes are those of the subcomponents of the corresponding
-- record.
elsif Ekind (Scope (Id)) /= E_Protected_Type
and then Present (Scope (Scope (Id))) -- error defense
and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
then
Conditional_Delay (Id, T);
end if;
-- If we have a subtype of an incomplete type whose full type is a
-- derived numeric type, we need to have a freeze node for the subtype.
-- Otherwise gigi will complain while computing the (static) bounds of
-- the subtype.
if Is_Itype (T)
and then Is_Elementary_Type (Id)
and then Etype (Id) /= Id
then
declare
Partial : constant Entity_Id :=
Incomplete_Or_Partial_View (First_Subtype (Id));
begin
if Present (Partial)
and then Ekind (Partial) = E_Incomplete_Type
then
Set_Has_Delayed_Freeze (Id);
end if;
end;
end if;
-- Check that Constraint_Error is raised for a scalar subtype indication
-- when the lower or upper bound of a non-null range lies outside the
-- range of the type mark. Likewise for an array subtype, but check the
-- compatibility for each index.
if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
declare
Indic_Typ : constant Entity_Id :=
Underlying_Type (Etype (Subtype_Mark (Subtype_Indication (N))));
Subt_Index : Node_Id;
Target_Index : Node_Id;
begin
if Is_Scalar_Type (Etype (Id))
and then Scalar_Range (Id) /= Scalar_Range (Indic_Typ)
then
Apply_Range_Check (Scalar_Range (Id), Indic_Typ);
elsif Is_Array_Type (Etype (Id))
and then Present (First_Index (Id))
then
Subt_Index := First_Index (Id);
Target_Index := First_Index (Indic_Typ);
while Present (Subt_Index) loop
if ((Nkind (Subt_Index) in N_Expanded_Name | N_Identifier
and then Is_Scalar_Type (Entity (Subt_Index)))
or else Nkind (Subt_Index) = N_Subtype_Indication)
and then
Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
then
Apply_Range_Check
(Scalar_Range (Etype (Subt_Index)),
Etype (Target_Index),
Insert_Node => N);
end if;
Next_Index (Subt_Index);
Next_Index (Target_Index);
end loop;
end if;
end;
end if;
Set_Optimize_Alignment_Flags (Id);
Check_Eliminated (Id);
<<Leave>>
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
Analyze_Dimension (N);
-- Check No_Dynamic_Sized_Objects restriction, which disallows subtype
-- indications on composite types where the constraints are dynamic.
-- Note that object declarations and aggregates generate implicit
-- subtype declarations, which this covers. One special case is that the
-- implicitly generated "=" for discriminated types includes an
-- offending subtype declaration, which is harmless, so we ignore it
-- here.
if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
declare
Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
begin
if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint
and then not (Is_Internal (Id)
and then Is_TSS (Scope (Id),
TSS_Composite_Equality))
and then not Within_Init_Proc
and then not All_Composite_Constraints_Static (Cstr)
then
Check_Restriction (No_Dynamic_Sized_Objects, Cstr);
end if;
end;
end if;
end Analyze_Subtype_Declaration;
--------------------------------
-- Analyze_Subtype_Indication --
--------------------------------
procedure Analyze_Subtype_Indication (N : Node_Id) is
T : constant Entity_Id := Subtype_Mark (N);
R : constant Node_Id := Range_Expression (Constraint (N));
begin
Analyze (T);
if R = Error then
Set_Error_Posted (R);
Set_Error_Posted (T);
else
Analyze (R);
Set_Etype (N, Etype (R));
Resolve (R, Entity (T));
end if;
end Analyze_Subtype_Indication;
--------------------------
-- Analyze_Variant_Part --
--------------------------
procedure Analyze_Variant_Part (N : Node_Id) is
Discr_Name : Node_Id;
Discr_Type : Entity_Id;
procedure Process_Variant (A : Node_Id);
-- Analyze declarations for a single variant
package Analyze_Variant_Choices is
new Generic_Analyze_Choices (Process_Variant);
use Analyze_Variant_Choices;
---------------------
-- Process_Variant --
---------------------
procedure Process_Variant (A : Node_Id) is
CL : constant Node_Id := Component_List (A);
begin
if not Null_Present (CL) then
Analyze_Declarations (Component_Items (CL));
if Present (Variant_Part (CL)) then
Analyze (Variant_Part (CL));
end if;
end if;
end Process_Variant;
-- Start of processing for Analyze_Variant_Part
begin
Discr_Name := Name (N);
Analyze (Discr_Name);
-- If Discr_Name bad, get out (prevent cascaded errors)
if Etype (Discr_Name) = Any_Type then
return;
end if;
-- Check invalid discriminant in variant part
if Ekind (Entity (Discr_Name)) /= E_Discriminant then
Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
end if;
Discr_Type := Etype (Entity (Discr_Name));
if not Is_Discrete_Type (Discr_Type) then
Error_Msg_N
("discriminant in a variant part must be of a discrete type",
Name (N));
return;
end if;
-- Now analyze the choices, which also analyzes the declarations that
-- are associated with each choice.
Analyze_Choices (Variants (N), Discr_Type);
-- Note: we used to instantiate and call Check_Choices here to check
-- that the choices covered the discriminant, but it's too early to do
-- that because of statically predicated subtypes, whose analysis may
-- be deferred to their freeze point which may be as late as the freeze
-- point of the containing record. So this call is now to be found in
-- Freeze_Record_Declaration.
end Analyze_Variant_Part;
----------------------------
-- Array_Type_Declaration --
----------------------------
procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
Component_Def : constant Node_Id := Component_Definition (Def);
Component_Typ : constant Node_Id := Subtype_Indication (Component_Def);
P : constant Node_Id := Parent (Def);
Element_Type : Entity_Id;
Implicit_Base : Entity_Id;
Index : Node_Id;
Nb_Index : Pos;
Priv : Entity_Id;
Related_Id : Entity_Id;
Has_FLB_Index : Boolean := False;
begin
if Nkind (Def) = N_Constrained_Array_Definition then
Index := First (Discrete_Subtype_Definitions (Def));
else
Index := First (Subtype_Marks (Def));
end if;
-- Find proper names for the implicit types which may be public. In case
-- of anonymous arrays we use the name of the first object of that type
-- as prefix.
if No (T) then
Related_Id := Defining_Identifier (P);
else
Related_Id := T;
end if;
Nb_Index := 1;
while Present (Index) loop
Analyze (Index);
-- Test for odd case of trying to index a type by the type itself
if Is_Entity_Name (Index) and then Entity (Index) = T then
Error_Msg_N ("type& cannot be indexed by itself", Index);
Set_Entity (Index, Standard_Boolean);
Set_Etype (Index, Standard_Boolean);
end if;
-- Add a subtype declaration for each index of private array type
-- declaration whose type is also private. For example:
-- package Pkg is
-- type Index is private;
-- private
-- type Table is array (Index) of ...
-- end;
-- This is currently required by the expander for the internally
-- generated equality subprogram of records with variant parts in
-- which the type of some component is such a private type. And it
-- also helps semantic analysis in peculiar cases where the array
-- type is referenced from an instance but not the index directly.
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Has_Private_Declaration (Etype (Index))
and then Scope (Etype (Index)) = Current_Scope
then
declare
Loc : constant Source_Ptr := Sloc (Def);
Decl : Node_Id;
New_E : Entity_Id;
begin
New_E := Make_Temporary (Loc, 'T');
Set_Is_Internal (New_E);
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => New_E,
Subtype_Indication =>
New_Occurrence_Of (Etype (Index), Loc));
Insert_Before (Parent (Def), Decl);
Analyze (Decl);
Set_Etype (Index, New_E);
-- If the index is a range or a subtype indication it carries
-- no entity. Example:
-- package Pkg is
-- type T is private;
-- private
-- type T is new Natural;
-- Table : array (T(1) .. T(10)) of Boolean;
-- end Pkg;
-- Otherwise the type of the reference is its entity.
if Is_Entity_Name (Index) then
Set_Entity (Index, New_E);
end if;
end;
end if;
Make_Index (Index, P, Related_Id, Nb_Index);
-- In the case where we have an unconstrained array with an index
-- given by a subtype_indication, this is necessarily a "fixed lower
-- bound" index. We change the upper bound of that index to the upper
-- bound of the index's subtype (denoted by the subtype_mark), since
-- that upper bound was originally set by the parser to be the same
-- as the lower bound. In truth, that upper bound corresponds to
-- a box ("<>"), and could be set to Empty, but it's convenient to
-- set it to the upper bound to avoid needing to add special tests
-- in various places for an Empty upper bound, and in any case that
-- accurately characterizes the index's range of values.
if Nkind (Def) = N_Unconstrained_Array_Definition
and then Nkind (Index) = N_Subtype_Indication
then
declare
Index_Subtype_High_Bound : constant Entity_Id :=
Type_High_Bound (Entity (Subtype_Mark (Index)));
begin
Set_High_Bound (Range_Expression (Constraint (Index)),
Index_Subtype_High_Bound);
-- Record that the array type has one or more indexes with
-- a fixed lower bound.
Has_FLB_Index := True;
-- Mark the index as belonging to an array type with a fixed
-- lower bound.
Set_Is_Fixed_Lower_Bound_Index_Subtype (Etype (Index));
end;
end if;
-- Check error of subtype with predicate for index type
Bad_Predicated_Subtype_Use
("subtype& has predicate, not allowed as index subtype",
Index, Etype (Index));
-- Move to next index
Next (Index);
Nb_Index := Nb_Index + 1;
end loop;
-- Process subtype indication if one is present
if Present (Component_Typ) then
Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
Set_Etype (Component_Typ, Element_Type);
-- Ada 2005 (AI-230): Access Definition case
else pragma Assert (Present (Access_Definition (Component_Def)));
-- Indicate that the anonymous access type is created by the
-- array type declaration.
Element_Type := Access_Definition
(Related_Nod => P,
N => Access_Definition (Component_Def));
Set_Is_Local_Anonymous_Access (Element_Type);
-- Propagate the parent. This field is needed if we have to generate
-- the master_id associated with an anonymous access to task type
-- component (see Expand_N_Full_Type_Declaration.Build_Master)
Copy_Parent (To => Element_Type, From => T);
-- Ada 2005 (AI-230): In case of components that are anonymous access
-- types the level of accessibility depends on the enclosing type
-- declaration
Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
-- Ada 2005 (AI-254)
declare
CD : constant Node_Id :=
Access_To_Subprogram_Definition
(Access_Definition (Component_Def));
begin
if Present (CD) and then Protected_Present (CD) then
Element_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram (Def);
end if;
end;
end if;
-- Constrained array case
if No (T) then
-- We might be creating more than one itype with the same Related_Id,
-- e.g. for an array object definition and its initial value. Give
-- them unique suffixes, because GNATprove require distinct types to
-- have different names.
T := Create_Itype (E_Void, P, Related_Id, 'T', Suffix_Index => -1);
end if;
if Nkind (Def) = N_Constrained_Array_Definition then
if Ekind (T) in Incomplete_Or_Private_Kind then
Reinit_Field_To_Zero (T, F_Stored_Constraint);
else
pragma Assert (Ekind (T) = E_Void);
end if;
-- Establish Implicit_Base as unconstrained base type
Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
Set_Scope (Implicit_Base, Current_Scope);
Set_Has_Delayed_Freeze (Implicit_Base);
Set_Default_SSO (Implicit_Base);
-- The constrained array type is a subtype of the unconstrained one
Mutate_Ekind (T, E_Array_Subtype);
Reinit_Size_Align (T);
Set_Etype (T, Implicit_Base);
Set_Scope (T, Current_Scope);
Set_Is_Constrained (T);
Set_First_Index (T,
First (Discrete_Subtype_Definitions (Def)));
Set_Has_Delayed_Freeze (T);
-- Complete setup of implicit base type
pragma Assert (not Known_Component_Size (Implicit_Base));
Set_Component_Type (Implicit_Base, Element_Type);
Set_Finalize_Storage_Only
(Implicit_Base,
Finalize_Storage_Only (Element_Type));
Set_First_Index (Implicit_Base, First_Index (T));
Set_Has_Controlled_Component
(Implicit_Base,
Has_Controlled_Component (Element_Type)
or else Is_Controlled (Element_Type));
Set_Packed_Array_Impl_Type
(Implicit_Base, Empty);
Propagate_Concurrent_Flags (Implicit_Base, Element_Type);
-- Unconstrained array case
else pragma Assert (Nkind (Def) = N_Unconstrained_Array_Definition);
if Ekind (T) in Incomplete_Or_Private_Kind then
Reinit_Field_To_Zero (T, F_Stored_Constraint);
else
pragma Assert (Ekind (T) = E_Void);
end if;
Mutate_Ekind (T, E_Array_Type);
Reinit_Size_Align (T);
Set_Etype (T, T);
Set_Scope (T, Current_Scope);
pragma Assert (not Known_Component_Size (T));
Set_Is_Constrained (T, False);
Set_Is_Fixed_Lower_Bound_Array_Subtype
(T, Has_FLB_Index);
Set_First_Index (T, First (Subtype_Marks (Def)));
Set_Has_Delayed_Freeze (T, True);
Propagate_Concurrent_Flags (T, Element_Type);
Set_Has_Controlled_Component (T, Has_Controlled_Component
(Element_Type)
or else
Is_Controlled (Element_Type));
Set_Finalize_Storage_Only (T, Finalize_Storage_Only
(Element_Type));
Set_Default_SSO (T);
end if;
-- Common attributes for both cases
Set_Component_Type (Base_Type (T), Element_Type);
Set_Packed_Array_Impl_Type (T, Empty);
if Aliased_Present (Component_Definition (Def)) then
Set_Has_Aliased_Components (Etype (T));
-- AI12-001: All aliased objects are considered to be specified as
-- independently addressable (RM C.6(8.1/4)).
Set_Has_Independent_Components (Etype (T));
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
-- array type to ensure that objects of this type are initialized.
if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (Element_Type) then
Set_Can_Never_Be_Null (T);
if Null_Exclusion_Present (Component_Definition (Def))
-- No need to check itypes because in their case this check was
-- done at their point of creation
and then not Is_Itype (Element_Type)
then
Error_Msg_N
("`NOT NULL` not allowed (null already excluded)",
Subtype_Indication (Component_Definition (Def)));
end if;
end if;
Priv := Private_Component (Element_Type);
if Present (Priv) then
-- Check for circular definitions
if Priv = Any_Type then
Set_Component_Type (Etype (T), Any_Type);
-- There is a gap in the visibility of operations on the composite
-- type only if the component type is defined in a different scope.
elsif Scope (Priv) = Current_Scope then
null;
elsif Is_Limited_Type (Priv) then
Set_Is_Limited_Composite (Etype (T));
Set_Is_Limited_Composite (T);
else
Set_Is_Private_Composite (Etype (T));
Set_Is_Private_Composite (T);
end if;
end if;
-- A syntax error in the declaration itself may lead to an empty index
-- list, in which case do a minimal patch.
if No (First_Index (T)) then
Error_Msg_N ("missing index definition in array type declaration", T);
declare
Indexes : constant List_Id :=
New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
begin
Set_Discrete_Subtype_Definitions (Def, Indexes);
Set_First_Index (T, First (Indexes));
return;
end;
end if;
-- Create a concatenation operator for the new type. Internal array
-- types created for packed entities do not need such, they are
-- compatible with the user-defined type.
if Number_Dimensions (T) = 1
and then not Is_Packed_Array_Impl_Type (T)
then
New_Concatenation_Op (T);
end if;
-- In the case of an unconstrained array the parser has already verified
-- that all the indexes are unconstrained but we still need to make sure
-- that the element type is constrained.
if not Is_Definite_Subtype (Element_Type) then
Error_Msg_N
("unconstrained element type in array declaration",
Subtype_Indication (Component_Def));
elsif Is_Abstract_Type (Element_Type) then
Error_Msg_N
("the type of a component cannot be abstract",
Subtype_Indication (Component_Def));
end if;
-- There may be an invariant declared for the component type, but
-- the construction of the component invariant checking procedure
-- takes place during expansion.
end Array_Type_Declaration;
------------------------------------------------------
-- Replace_Anonymous_Access_To_Protected_Subprogram --
------------------------------------------------------
function Replace_Anonymous_Access_To_Protected_Subprogram
(N : Node_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (N);
Curr_Scope : constant Scope_Stack_Entry :=
Scope_Stack.Table (Scope_Stack.Last);
Anon : constant Entity_Id := Make_Temporary (Loc, 'S');
Acc : Node_Id;
-- Access definition in declaration
Comp : Node_Id;
-- Object definition or formal definition with an access definition
Decl : Node_Id;
-- Declaration of anonymous access to subprogram type
Spec : Node_Id;
-- Original specification in access to subprogram
P : Node_Id;
begin
Set_Is_Internal (Anon);
case Nkind (N) is
when N_Constrained_Array_Definition
| N_Component_Declaration
| N_Unconstrained_Array_Definition
=>
Comp := Component_Definition (N);
Acc := Access_Definition (Comp);
when N_Discriminant_Specification =>
Comp := Discriminant_Type (N);
Acc := Comp;
when N_Parameter_Specification =>
Comp := Parameter_Type (N);
Acc := Comp;
when N_Access_Function_Definition =>
Comp := Result_Definition (N);
Acc := Comp;
when N_Object_Declaration =>
Comp := Object_Definition (N);
Acc := Comp;
when N_Function_Specification =>
Comp := Result_Definition (N);
Acc := Comp;
when others =>
raise Program_Error;
end case;
Spec := Access_To_Subprogram_Definition (Acc);
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Anon,
Type_Definition => Copy_Separate_Tree (Spec));
Mark_Rewrite_Insertion (Decl);
-- Insert the new declaration in the nearest enclosing scope. If the
-- parent is a body and N is its return type, the declaration belongs
-- in the enclosing scope. Likewise if N is the type of a parameter.
P := Parent (N);
if Nkind (N) = N_Function_Specification
and then Nkind (P) = N_Subprogram_Body
then
P := Parent (P);
elsif Nkind (N) = N_Parameter_Specification
and then Nkind (P) in N_Subprogram_Specification
and then Nkind (Parent (P)) = N_Subprogram_Body
then
P := Parent (Parent (P));
end if;
while Present (P) and then not Has_Declarations (P) loop
P := Parent (P);
end loop;
pragma Assert (Present (P));
if Nkind (P) = N_Package_Specification then
Prepend (Decl, Visible_Declarations (P));
else
Prepend (Decl, Declarations (P));
end if;
-- Replace the anonymous type with an occurrence of the new declaration.
-- In all cases the rewritten node does not have the null-exclusion
-- attribute because (if present) it was already inherited by the
-- anonymous entity (Anon). Thus, in case of components we do not
-- inherit this attribute.
if Nkind (N) = N_Parameter_Specification then
Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
Set_Etype (Defining_Identifier (N), Anon);
Set_Null_Exclusion_Present (N, False);
elsif Nkind (N) = N_Object_Declaration then
Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
Set_Etype (Defining_Identifier (N), Anon);
elsif Nkind (N) = N_Access_Function_Definition then
Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
elsif Nkind (N) = N_Function_Specification then
Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
Set_Etype (Defining_Unit_Name (N), Anon);
else
Rewrite (Comp,
Make_Component_Definition (Loc,
Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
end if;
Mark_Rewrite_Insertion (Comp);
if Nkind (N) in N_Object_Declaration | N_Access_Function_Definition
or else (Nkind (Parent (N)) = N_Full_Type_Declaration
and then not Is_Type (Current_Scope))
then
-- Declaration can be analyzed in the current scope.
Analyze (Decl);
else
-- Temporarily remove the current scope (record or subprogram) from
-- the stack to add the new declarations to the enclosing scope.
-- The anonymous entity is an Itype with the proper attributes.
Scope_Stack.Decrement_Last;
Analyze (Decl);
Set_Is_Itype (Anon);
Set_Associated_Node_For_Itype (Anon, N);
Scope_Stack.Append (Curr_Scope);
end if;
Mutate_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
return Anon;
end Replace_Anonymous_Access_To_Protected_Subprogram;
-------------------------------------
-- Build_Access_Subprogram_Wrapper --
-------------------------------------
procedure Build_Access_Subprogram_Wrapper (Decl : Node_Id) is
Loc : constant Source_Ptr := Sloc (Decl);
Id : constant Entity_Id := Defining_Identifier (Decl);
Type_Def : constant Node_Id := Type_Definition (Decl);
Specs : constant List_Id :=
Parameter_Specifications (Type_Def);
Profile : constant List_Id := New_List;
Subp : constant Entity_Id := Make_Temporary (Loc, 'A');
Contracts : constant List_Id := New_List;
Form_P : Node_Id;
New_P : Node_Id;
New_Decl : Node_Id;
Spec : Node_Id;
procedure Replace_Type_Name (Expr : Node_Id);
-- In the expressions for contract aspects, replace occurrences of the
-- access type with the name of the subprogram entity, as needed, e.g.
-- for 'Result. Aspects that are not contracts, e.g. Size or Alignment)
-- remain on the original access type declaration. What about expanded
-- names denoting formals, whose prefix in source is the type name ???
-----------------------
-- Replace_Type_Name --
-----------------------
procedure Replace_Type_Name (Expr : Node_Id) is
function Process (N : Node_Id) return Traverse_Result;
function Process (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Attribute_Reference
and then Is_Entity_Name (Prefix (N))
and then Chars (Prefix (N)) = Chars (Id)
then
Set_Prefix (N, Make_Identifier (Sloc (N), Chars (Subp)));
end if;
return OK;
end Process;
procedure Traverse is new Traverse_Proc (Process);
begin
Traverse (Expr);
end Replace_Type_Name;
begin
if Ekind (Id) in E_Access_Subprogram_Type
| E_Access_Protected_Subprogram_Type
| E_Anonymous_Access_Protected_Subprogram_Type
| E_Anonymous_Access_Subprogram_Type
then
null;
else
Error_Msg_N
("illegal pre/postcondition on access type", Decl);
return;
end if;
declare
Asp : Node_Id;
A_Id : Aspect_Id;
Cond : Node_Id;
Expr : Node_Id;
begin
Asp := First (Aspect_Specifications (Decl));
while Present (Asp) loop
A_Id := Get_Aspect_Id (Chars (Identifier (Asp)));
if A_Id = Aspect_Pre or else A_Id = Aspect_Post then
Cond := Asp;
Expr := Expression (Cond);
Replace_Type_Name (Expr);
Next (Asp);
Remove (Cond);
Append (Cond, Contracts);
else
Next (Asp);
end if;
end loop;
end;
-- If there are no contract aspects, no need for a wrapper.
if Is_Empty_List (Contracts) then
return;
end if;
Form_P := First (Specs);
while Present (Form_P) loop
New_P := New_Copy_Tree (Form_P);
Set_Defining_Identifier (New_P,
Make_Defining_Identifier
(Loc, Chars (Defining_Identifier (Form_P))));
Append (New_P, Profile);
Next (Form_P);
end loop;
-- Add to parameter specifications the access parameter that is passed
-- in from an indirect call.
Append (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Temporary (Loc, 'P'),
Parameter_Type => New_Occurrence_Of (Id, Loc)),
Profile);
if Nkind (Type_Def) = N_Access_Procedure_Definition then
Spec :=
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Subp,
Parameter_Specifications => Profile);
Mutate_Ekind (Subp, E_Procedure);
else
Spec :=
Make_Function_Specification (Loc,
Defining_Unit_Name => Subp,
Parameter_Specifications => Profile,
Result_Definition =>
New_Copy_Tree
(Result_Definition (Type_Definition (Decl))));
Mutate_Ekind (Subp, E_Function);
end if;
New_Decl :=
Make_Subprogram_Declaration (Loc, Specification => Spec);
Set_Aspect_Specifications (New_Decl, Contracts);
Set_Is_Wrapper (Subp);
-- The wrapper is declared in the freezing actions to facilitate its
-- identification and thus avoid handling it as a primitive operation
-- of a tagged type (see Is_Access_To_Subprogram_Wrapper); otherwise it
-- may be handled as a dispatching operation and erroneously registered
-- in a dispatch table.
if not GNATprove_Mode then
Append_Freeze_Action (Id, New_Decl);
-- Under GNATprove mode there is no such problem but we do not declare
-- it in the freezing actions since they are not analyzed under this
-- mode.
else
Insert_After (Decl, New_Decl);
end if;
Set_Access_Subprogram_Wrapper (Designated_Type (Id), Subp);
Build_Access_Subprogram_Wrapper_Body (Decl, New_Decl);
end Build_Access_Subprogram_Wrapper;
-------------------------------
-- Build_Derived_Access_Type --
-------------------------------
procedure Build_Derived_Access_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
S : constant Node_Id := Subtype_Indication (Type_Definition (N));
Desig_Type : Entity_Id;
Discr : Entity_Id;
Discr_Con_Elist : Elist_Id;
Discr_Con_El : Elmt_Id;
Subt : Entity_Id;
begin
-- Set the designated type so it is available in case this is an access
-- to a self-referential type, e.g. a standard list type with a next
-- pointer. Will be reset after subtype is built.
Set_Directly_Designated_Type
(Derived_Type, Designated_Type (Parent_Type));
Subt := Process_Subtype (S, N);
if Nkind (S) /= N_Subtype_Indication
and then Subt /= Base_Type (Subt)
then
Mutate_Ekind (Derived_Type, E_Access_Subtype);
end if;
if Ekind (Derived_Type) = E_Access_Subtype then
declare
Pbase : constant Entity_Id := Base_Type (Parent_Type);
Ibase : constant Entity_Id :=
Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
Svg_Chars : constant Name_Id := Chars (Ibase);
Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
Svg_Prev_E : constant Entity_Id := Prev_Entity (Ibase);
begin
Copy_Node (Pbase, Ibase);
-- Restore Itype status after Copy_Node
Set_Is_Itype (Ibase);
Set_Associated_Node_For_Itype (Ibase, N);
Set_Chars (Ibase, Svg_Chars);
Set_Prev_Entity (Ibase, Svg_Prev_E);
Set_Next_Entity (Ibase, Svg_Next_E);
Set_Sloc (Ibase, Sloc (Derived_Type));
Set_Scope (Ibase, Scope (Derived_Type));
Set_Freeze_Node (Ibase, Empty);
Set_Is_Frozen (Ibase, False);
Set_Comes_From_Source (Ibase, False);
Set_Is_First_Subtype (Ibase, False);
Set_Etype (Ibase, Pbase);
Set_Etype (Derived_Type, Ibase);
end;
end if;
Set_Directly_Designated_Type
(Derived_Type, Designated_Type (Subt));
Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
Set_Size_Info (Derived_Type, Parent_Type);
Copy_RM_Size (To => Derived_Type, From => Parent_Type);
Set_Depends_On_Private (Derived_Type,
Has_Private_Component (Derived_Type));
Conditional_Delay (Derived_Type, Subt);
if Is_Access_Subprogram_Type (Derived_Type)
and then Is_Base_Type (Derived_Type)
then
Set_Can_Use_Internal_Rep
(Derived_Type, Can_Use_Internal_Rep (Parent_Type));
end if;
-- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify
-- that it is not redundant.
if Null_Exclusion_Present (Type_Definition (N)) then
Set_Can_Never_Be_Null (Derived_Type);
elsif Can_Never_Be_Null (Parent_Type) then
Set_Can_Never_Be_Null (Derived_Type);
end if;
-- Note: we do not copy the Storage_Size_Variable, since we always go to
-- the root type for this information.
-- Apply range checks to discriminants for derived record case
-- ??? THIS CODE SHOULD NOT BE HERE REALLY.
Desig_Type := Designated_Type (Derived_Type);
if Is_Composite_Type (Desig_Type)
and then (not Is_Array_Type (Desig_Type))
and then Has_Discriminants (Desig_Type)
and then Base_Type (Desig_Type) /= Desig_Type
then
Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
Discr_Con_El := First_Elmt (Discr_Con_Elist);
Discr := First_Discriminant (Base_Type (Desig_Type));
while Present (Discr_Con_El) loop
Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
Next_Elmt (Discr_Con_El);
Next_Discriminant (Discr);
end loop;
end if;
end Build_Derived_Access_Type;
------------------------------
-- Build_Derived_Array_Type --
------------------------------
procedure Build_Derived_Array_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : Entity_Id := Empty;
New_Indic : Node_Id;
procedure Make_Implicit_Base;
-- If the parent subtype is constrained, the derived type is a subtype
-- of an implicit base type derived from the parent base.
------------------------
-- Make_Implicit_Base --
------------------------
procedure Make_Implicit_Base is
begin
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Mutate_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Etype (Implicit_Base, Parent_Base);
Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
Set_Has_Delayed_Freeze (Implicit_Base, True);
end Make_Implicit_Base;
-- Start of processing for Build_Derived_Array_Type
begin
if not Is_Constrained (Parent_Type) then
if Nkind (Indic) /= N_Subtype_Indication then
Mutate_Ekind (Derived_Type, E_Array_Type);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
Set_Has_Delayed_Freeze (Derived_Type, True);
else
Make_Implicit_Base;
Set_Etype (Derived_Type, Implicit_Base);
New_Indic :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
Constraint => Constraint (Indic)));
Rewrite (N, New_Indic);
Analyze (N);
end if;
else
if Nkind (Indic) /= N_Subtype_Indication then
Make_Implicit_Base;
Mutate_Ekind (Derived_Type, Ekind (Parent_Type));
Set_Etype (Derived_Type, Implicit_Base);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
else
Error_Msg_N ("illegal constraint on constrained type", Indic);
end if;
end if;
-- If parent type is not a derived type itself, and is declared in
-- closed scope (e.g. a subprogram), then we must explicitly introduce
-- the new type's concatenation operator since Derive_Subprograms
-- will not inherit the parent's operator. If the parent type is
-- unconstrained, the operator is of the unconstrained base type.
if Number_Dimensions (Parent_Type) = 1
and then not Is_Limited_Type (Parent_Type)
and then not Is_Derived_Type (Parent_Type)
and then not Is_Package_Or_Generic_Package
(Scope (Base_Type (Parent_Type)))
then
if not Is_Constrained (Parent_Type)
and then Is_Constrained (Derived_Type)
then
New_Concatenation_Op (Implicit_Base);
else
New_Concatenation_Op (Derived_Type);
end if;
end if;
end Build_Derived_Array_Type;
-----------------------------------
-- Build_Derived_Concurrent_Type --
-----------------------------------
procedure Build_Derived_Concurrent_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
Corr_Decl : Node_Id := Empty;
Corr_Decl_Needed : Boolean;
-- If the derived type has fewer discriminants than its parent, the
-- corresponding record is also a derived type, in order to account for
-- the bound discriminants. We create a full type declaration for it in
-- this case.
Constraint_Present : constant Boolean :=
Nkind (Indic) = N_Subtype_Indication;
D_Constraint : Node_Id;
New_Constraint : Elist_Id := No_Elist;
Old_Disc : Entity_Id;
New_Disc : Entity_Id;
New_N : Node_Id;
begin
Set_Stored_Constraint (Derived_Type, No_Elist);
Corr_Decl_Needed := False;
Old_Disc := Empty;
if Present (Discriminant_Specifications (N))
and then Constraint_Present
then
Old_Disc := First_Discriminant (Parent_Type);
New_Disc := First (Discriminant_Specifications (N));
while Present (New_Disc) and then Present (Old_Disc) loop
Next_Discriminant (Old_Disc);
Next (New_Disc);
end loop;
end if;
if Present (Old_Disc) and then Expander_Active then
-- The new type has fewer discriminants, so we need to create a new
-- corresponding record, which is derived from the corresponding
-- record of the parent, and has a stored constraint that captures
-- the values of the discriminant constraints. The corresponding
-- record is needed only if expander is active and code generation is
-- enabled.
-- The type declaration for the derived corresponding record has the
-- same discriminant part and constraints as the current declaration.
-- Copy the unanalyzed tree to build declaration.
Corr_Decl_Needed := True;
New_N := Copy_Separate_Tree (N);
Corr_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Corr_Record,
Discriminant_Specifications =>
Discriminant_Specifications (New_N),
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of
(Corresponding_Record_Type (Parent_Type), Loc),
Constraint =>
Constraint
(Subtype_Indication (Type_Definition (New_N))))));
end if;
-- Copy Storage_Size and Relative_Deadline variables if task case
if Is_Task_Type (Parent_Type) then
Set_Storage_Size_Variable (Derived_Type,
Storage_Size_Variable (Parent_Type));
Set_Relative_Deadline_Variable (Derived_Type,
Relative_Deadline_Variable (Parent_Type));
end if;
if Present (Discriminant_Specifications (N)) then
Push_Scope (Derived_Type);
Check_Or_Process_Discriminants (N, Derived_Type);
if Constraint_Present then
New_Constraint :=
Expand_To_Stored_Constraint
(Parent_Type,
Build_Discriminant_Constraints
(Parent_Type, Indic, True));
end if;
End_Scope;
elsif Constraint_Present then
-- Build an unconstrained derived type and rewrite the derived type
-- as a subtype of this new base type.
declare
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
New_Base : Entity_Id;
New_Decl : Node_Id;
New_Indic : Node_Id;
begin
New_Base :=
Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
New_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => New_Base,
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Abstract_Present => Abstract_Present (Def),
Limited_Present => Limited_Present (Def),
Subtype_Indication =>
New_Occurrence_Of (Parent_Base, Loc)));
Mark_Rewrite_Insertion (New_Decl);
Insert_Before (N, New_Decl);
Analyze (New_Decl);
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint => Relocate_Node (Constraint (Indic)));
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication => New_Indic));
Analyze (N);
return;
end;
end if;
-- By default, operations and private data are inherited from parent.
-- However, in the presence of bound discriminants, a new corresponding
-- record will be created, see below.
Set_Has_Discriminants
(Derived_Type, Has_Discriminants (Parent_Type));
Set_Corresponding_Record_Type
(Derived_Type, Corresponding_Record_Type (Parent_Type));
-- Is_Constrained is set according the parent subtype, but is set to
-- False if the derived type is declared with new discriminants.
Set_Is_Constrained
(Derived_Type,
(Is_Constrained (Parent_Type) or else Constraint_Present)
and then not Present (Discriminant_Specifications (N)));
if Constraint_Present then
if not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", N);
elsif Present (Discriminant_Specifications (N)) then
-- Verify that new discriminants are used to constrain old ones
D_Constraint := First (Constraints (Constraint (Indic)));
Old_Disc := First_Discriminant (Parent_Type);
while Present (D_Constraint) loop
if Nkind (D_Constraint) /= N_Discriminant_Association then
-- Positional constraint. If it is a reference to a new
-- discriminant, it constrains the corresponding old one.
if Nkind (D_Constraint) = N_Identifier then
New_Disc := First_Discriminant (Derived_Type);
while Present (New_Disc) loop
exit when Chars (New_Disc) = Chars (D_Constraint);
Next_Discriminant (New_Disc);
end loop;
if Present (New_Disc) then
Set_Corresponding_Discriminant (New_Disc, Old_Disc);
end if;
end if;
Next_Discriminant (Old_Disc);
-- if this is a named constraint, search by name for the old
-- discriminants constrained by the new one.
elsif Nkind (Expression (D_Constraint)) = N_Identifier then
-- Find new discriminant with that name
New_Disc := First_Discriminant (Derived_Type);
while Present (New_Disc) loop
exit when
Chars (New_Disc) = Chars (Expression (D_Constraint));
Next_Discriminant (New_Disc);
end loop;
if Present (New_Disc) then
-- Verify that new discriminant renames some discriminant
-- of the parent type, and associate the new discriminant
-- with one or more old ones that it renames.
declare
Selector : Node_Id;
begin
Selector := First (Selector_Names (D_Constraint));
while Present (Selector) loop
Old_Disc := First_Discriminant (Parent_Type);
while Present (Old_Disc) loop
exit when Chars (Old_Disc) = Chars (Selector);
Next_Discriminant (Old_Disc);
end loop;
if Present (Old_Disc) then
Set_Corresponding_Discriminant
(New_Disc, Old_Disc);
end if;
Next (Selector);
end loop;
end;
end if;
end if;
Next (D_Constraint);
end loop;
New_Disc := First_Discriminant (Derived_Type);
while Present (New_Disc) loop
if No (Corresponding_Discriminant (New_Disc)) then
Error_Msg_NE
("new discriminant& must constrain old one", N, New_Disc);
-- If a new discriminant is used in the constraint, then its
-- subtype must be statically compatible with the subtype of
-- the parent discriminant (RM 3.7(15)).
else
Check_Constraining_Discriminant
(New_Disc, Corresponding_Discriminant (New_Disc));
end if;
Next_Discriminant (New_Disc);
end loop;
end if;
elsif Present (Discriminant_Specifications (N)) then
Error_Msg_N
("missing discriminant constraint in untagged derivation", N);
end if;
-- The entity chain of the derived type includes the new discriminants
-- but shares operations with the parent.
if Present (Discriminant_Specifications (N)) then
Old_Disc := First_Discriminant (Parent_Type);
while Present (Old_Disc) loop
if No (Next_Entity (Old_Disc))
or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
then
Link_Entities
(Last_Entity (Derived_Type), Next_Entity (Old_Disc));
exit;
end if;
Next_Discriminant (Old_Disc);
end loop;
else
Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
if Has_Discriminants (Parent_Type) then
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
Set_Discriminant_Constraint (
Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
Set_Has_Completion (Derived_Type);
if Corr_Decl_Needed then
Set_Stored_Constraint (Derived_Type, New_Constraint);
Insert_After (N, Corr_Decl);
Analyze (Corr_Decl);
Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
end if;
end Build_Derived_Concurrent_Type;
------------------------------------
-- Build_Derived_Enumeration_Type --
------------------------------------
procedure Build_Derived_Enumeration_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
function Bound_Belongs_To_Type (B : Node_Id) return Boolean;
-- When the type declaration includes a constraint, we generate
-- a subtype declaration of an anonymous base type, with the constraint
-- given in the original type declaration. Conceptually, the bounds
-- are converted to the new base type, and this conversion freezes
-- (prematurely) that base type, when the bounds are simply literals.
-- As a result, a representation clause for the derived type is then
-- rejected or ignored. This procedure recognizes the simple case of
-- literal bounds, which allows us to indicate that the conversions
-- are not freeze points, and the subsequent representation clause
-- can be accepted.
-- A similar approach might be used to resolve the long-standing
-- problem of premature freezing of derived numeric types ???
function Bound_Belongs_To_Type (B : Node_Id) return Boolean is
begin
return Nkind (B) = N_Type_Conversion
and then Is_Entity_Name (Expression (B))
and then Ekind (Entity (Expression (B))) = E_Enumeration_Literal;
end Bound_Belongs_To_Type;
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Implicit_Base : Entity_Id;
Literal : Entity_Id;
New_Lit : Entity_Id;
Literals_List : List_Id;
Type_Decl : Node_Id;
Hi, Lo : Node_Id;
Rang_Expr : Node_Id;
begin
-- Since types Standard.Character and Standard.[Wide_]Wide_Character do
-- not have explicit literals lists we need to process types derived
-- from them specially. This is handled by Derived_Standard_Character.
-- If the parent type is a generic type, there are no literals either,
-- and we construct the same skeletal representation as for the generic
-- parent type.
if Is_Standard_Character_Type (Parent_Type) then
Derived_Standard_Character (N, Parent_Type, Derived_Type);
elsif Is_Generic_Type (Root_Type (Parent_Type)) then
declare
Lo : Node_Id;
Hi : Node_Id;
begin
if Nkind (Indic) /= N_Subtype_Indication then
Lo :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Occurrence_Of (Derived_Type, Loc));
Set_Etype (Lo, Derived_Type);
Hi :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Occurrence_Of (Derived_Type, Loc));
Set_Etype (Hi, Derived_Type);
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
else
-- Analyze subtype indication and verify compatibility
-- with parent type.
if Base_Type (Process_Subtype (Indic, N)) /=
Base_Type (Parent_Type)
then
Error_Msg_N
("illegal constraint for formal discrete type", N);
end if;
end if;
end;
else
-- If a constraint is present, analyze the bounds to catch
-- premature usage of the derived literals.
if Nkind (Indic) = N_Subtype_Indication
and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
then
Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
Analyze (High_Bound (Range_Expression (Constraint (Indic))));
end if;
-- Create an implicit base type for the derived type even if there
-- is no constraint attached to it, since this seems closer to the
-- Ada semantics. Use an Itype like for the implicit base type of
-- other kinds of derived type, but build a full type declaration
-- for it so as to analyze the new literals properly. Then build a
-- subtype declaration tree which applies the constraint (if any)
-- and have it replace the derived type declaration.
Literal := First_Literal (Parent_Type);
Literals_List := New_List;
while Present (Literal)
and then Ekind (Literal) = E_Enumeration_Literal
loop
-- Literals of the derived type have the same representation as
-- those of the parent type, but this representation can be
-- overridden by an explicit representation clause. Indicate
-- that there is no explicit representation given yet. These
-- derived literals are implicit operations of the new type,
-- and can be overridden by explicit ones.
if Nkind (Literal) = N_Defining_Character_Literal then
New_Lit :=
Make_Defining_Character_Literal (Loc, Chars (Literal));
else
New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
end if;
Mutate_Ekind (New_Lit, E_Enumeration_Literal);
Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
Set_Enumeration_Rep_Expr (New_Lit, Empty);
Set_Alias (New_Lit, Literal);
Set_Is_Known_Valid (New_Lit, True);
Append (New_Lit, Literals_List);
Next_Literal (Literal);
end loop;
Implicit_Base :=
Create_Itype (E_Enumeration_Type, N, Derived_Type, 'B');
-- Indicate the proper nature of the derived type. This must be done
-- before analysis of the literals, to recognize cases when a literal
-- may be hidden by a previous explicit function definition (cf.
-- c83031a).
Mutate_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Type_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Implicit_Base,
Type_Definition =>
Make_Enumeration_Type_Definition (Loc, Literals_List));
-- Do not insert the declarationn, just analyze it in the context
Set_Parent (Type_Decl, Parent (N));
Analyze (Type_Decl);
-- The anonymous base now has a full declaration, but this base
-- is not a first subtype.
Set_Is_First_Subtype (Implicit_Base, False);
-- After the implicit base is analyzed its Etype needs to be changed
-- to reflect the fact that it is derived from the parent type which
-- was ignored during analysis. We also set the size at this point.
Set_Etype (Implicit_Base, Parent_Type);
Set_Size_Info (Implicit_Base, Parent_Type);
Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
-- Copy other flags from parent type
Set_Has_Non_Standard_Rep
(Implicit_Base, Has_Non_Standard_Rep
(Parent_Type));
Set_Has_Pragma_Ordered
(Implicit_Base, Has_Pragma_Ordered
(Parent_Type));
Set_Has_Delayed_Freeze (Implicit_Base);
-- Process the subtype indication including a validation check on the
-- constraint, if any. If a constraint is given, its bounds must be
-- implicitly converted to the new type.
if Nkind (Indic) = N_Subtype_Indication then
declare
R : constant Node_Id :=
Range_Expression (Constraint (Indic));
begin
if Nkind (R) = N_Range then
Hi := Build_Scalar_Bound
(High_Bound (R), Parent_Type, Implicit_Base);
Lo := Build_Scalar_Bound
(Low_Bound (R), Parent_Type, Implicit_Base);
else
-- Constraint is a Range attribute. Replace with explicit
-- mention of the bounds of the prefix, which must be a
-- subtype.
Analyze (Prefix (R));
Hi :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
Lo :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
end if;
end;
else
Hi :=
Build_Scalar_Bound
(Type_High_Bound (Parent_Type),
Parent_Type, Implicit_Base);
Lo :=
Build_Scalar_Bound
(Type_Low_Bound (Parent_Type),
Parent_Type, Implicit_Base);
end if;
Rang_Expr :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
-- If we constructed a default range for the case where no range
-- was given, then the expressions in the range must not freeze
-- since they do not correspond to expressions in the source.
-- However, if the type inherits predicates the expressions will
-- be elaborated earlier and must freeze.
if (Nkind (Indic) /= N_Subtype_Indication
or else
(Bound_Belongs_To_Type (Lo) and then Bound_Belongs_To_Type (Hi)))
and then not Has_Predicates (Derived_Type)
then
Set_Must_Not_Freeze (Lo);
Set_Must_Not_Freeze (Hi);
Set_Must_Not_Freeze (Rang_Expr);
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
Constraint =>
Make_Range_Constraint (Loc,
Range_Expression => Rang_Expr))));
Analyze (N);
-- Propagate the aspects from the original type declaration to the
-- declaration of the implicit base.
Move_Aspects (From => Original_Node (N), To => Type_Decl);
-- Apply a range check. Since this range expression doesn't have an
-- Etype, we have to specifically pass the Source_Typ parameter. Is
-- this right???
if Nkind (Indic) = N_Subtype_Indication then
Apply_Range_Check
(Range_Expression (Constraint (Indic)), Parent_Type,
Source_Typ => Entity (Subtype_Mark (Indic)));
end if;
end if;
end Build_Derived_Enumeration_Type;
--------------------------------
-- Build_Derived_Numeric_Type --
--------------------------------
procedure Build_Derived_Numeric_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
No_Constraint : constant Boolean := Nkind (Indic) /=
N_Subtype_Indication;
Implicit_Base : Entity_Id;
Lo : Node_Id;
Hi : Node_Id;
begin
-- Process the subtype indication including a validation check on
-- the constraint if any.
Discard_Node (Process_Subtype (Indic, N));
-- Introduce an implicit base type for the derived type even if there
-- is no constraint attached to it, since this seems closer to the Ada
-- semantics.
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Set_Etype (Implicit_Base, Parent_Base);
Mutate_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Size_Info (Implicit_Base, Parent_Base);
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
Set_Parent (Implicit_Base, Parent (Derived_Type));
Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
Set_Is_Volatile (Implicit_Base, Is_Volatile (Parent_Base));
-- Set RM Size for discrete type or decimal fixed-point type
-- Ordinary fixed-point is excluded, why???
if Is_Discrete_Type (Parent_Base)
or else Is_Decimal_Fixed_Point_Type (Parent_Base)
then
Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
end if;
Set_Has_Delayed_Freeze (Implicit_Base);
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
if Has_Infinities (Parent_Base) then
Set_Includes_Infinities (Scalar_Range (Implicit_Base));
end if;
-- The Derived_Type, which is the entity of the declaration, is a
-- subtype of the implicit base. Its Ekind is a subtype, even in the
-- absence of an explicit constraint.
Set_Etype (Derived_Type, Implicit_Base);
-- If we did not have a constraint, then the Ekind is set from the
-- parent type (otherwise Process_Subtype has set the bounds)
if No_Constraint then
Mutate_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
end if;
-- If we did not have a range constraint, then set the range from the
-- parent type. Otherwise, the Process_Subtype call has set the bounds.
if No_Constraint or else not Has_Range_Constraint (Indic) then
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
if Has_Infinities (Parent_Type) then
Set_Includes_Infinities (Scalar_Range (Derived_Type));
end if;
Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
end if;
Set_Is_Descendant_Of_Address (Derived_Type,
Is_Descendant_Of_Address (Parent_Type));
Set_Is_Descendant_Of_Address (Implicit_Base,
Is_Descendant_Of_Address (Parent_Type));
-- Set remaining type-specific fields, depending on numeric type
if Is_Modular_Integer_Type (Parent_Type) then
Set_Modulus (Implicit_Base, Modulus (Parent_Base));
Set_Non_Binary_Modulus
(Implicit_Base, Non_Binary_Modulus (Parent_Base));
Set_Is_Known_Valid
(Implicit_Base, Is_Known_Valid (Parent_Base));
elsif Is_Floating_Point_Type (Parent_Type) then
-- Digits of base type is always copied from the digits value of
-- the parent base type, but the digits of the derived type will
-- already have been set if there was a constraint present.
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
end if;
elsif Is_Fixed_Point_Type (Parent_Type) then
-- Small of base type and derived type are always copied from the
-- parent base type, since smalls never change. The delta of the
-- base type is also copied from the parent base type. However the
-- delta of the derived type will have been set already if a
-- constraint was present.
Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
if No_Constraint then
Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
end if;
-- The scale and machine radix in the decimal case are always
-- copied from the parent base type.
if Is_Decimal_Fixed_Point_Type (Parent_Type) then
Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
Set_Machine_Radix_10
(Derived_Type, Machine_Radix_10 (Parent_Base));
Set_Machine_Radix_10
(Implicit_Base, Machine_Radix_10 (Parent_Base));
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
else
-- the analysis of the subtype_indication sets the
-- digits value of the derived type.
null;
end if;
end if;
end if;
if Is_Integer_Type (Parent_Type) then
Set_Has_Shift_Operator
(Implicit_Base, Has_Shift_Operator (Parent_Type));
end if;
-- The type of the bounds is that of the parent type, and they
-- must be converted to the derived type.
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
end Build_Derived_Numeric_Type;
--------------------------------
-- Build_Derived_Private_Type --
--------------------------------
procedure Build_Derived_Private_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (N);
Par_Base : constant Entity_Id := Base_Type (Parent_Type);
Par_Scope : constant Entity_Id := Scope (Par_Base);
Full_N : constant Node_Id := New_Copy_Tree (N);
Full_Der : Entity_Id := New_Copy (Derived_Type);
Full_P : Entity_Id;
function Available_Full_View (Typ : Entity_Id) return Entity_Id;
-- Return the Full_View or Underlying_Full_View of Typ, whichever is
-- present (they cannot be both present for the same type), or Empty.
procedure Build_Full_Derivation;
-- Build full derivation, i.e. derive from the full view
procedure Copy_And_Build;
-- Copy derived type declaration, replace parent with its full view,
-- and build derivation
-------------------------
-- Available_Full_View --
-------------------------
function Available_Full_View (Typ : Entity_Id) return Entity_Id is
begin
if Present (Full_View (Typ)) then
return Full_View (Typ);
elsif Present (Underlying_Full_View (Typ)) then
-- We should be called on a type with an underlying full view
-- only by means of the recursive call made in Copy_And_Build
-- through the first call to Build_Derived_Type, or else if
-- the parent scope is being analyzed because we are deriving
-- a completion.
pragma Assert (Is_Completion or else In_Private_Part (Par_Scope));
return Underlying_Full_View (Typ);
else
return Empty;
end if;
end Available_Full_View;
---------------------------
-- Build_Full_Derivation --
---------------------------
procedure Build_Full_Derivation is
begin
-- If parent scope is not open, install the declarations
if not In_Open_Scopes (Par_Scope) then
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Copy_And_Build;
Uninstall_Declarations (Par_Scope);
-- If parent scope is open and in another unit, and parent has a
-- completion, then the derivation is taking place in the visible
-- part of a child unit. In that case retrieve the full view of
-- the parent momentarily.
elsif not In_Same_Source_Unit (N, Parent_Type)
and then Present (Full_View (Parent_Type))
then
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
-- Otherwise it is a local derivation
else
Copy_And_Build;
end if;
end Build_Full_Derivation;
--------------------
-- Copy_And_Build --
--------------------
procedure Copy_And_Build is
Full_Parent : Entity_Id := Parent_Type;
begin
-- If the parent is itself derived from another private type,
-- installing the private declarations has not affected its
-- privacy status, so use its own full view explicitly.
if Is_Private_Type (Full_Parent)
and then Present (Full_View (Full_Parent))
then
Full_Parent := Full_View (Full_Parent);
end if;
-- If the full view is itself derived from another private type
-- and has got an underlying full view, and this is done for a
-- completion, i.e. to build the underlying full view of the type,
-- then use this underlying full view. We cannot do that if this
-- is not a completion, i.e. to build the full view of the type,
-- because this would break the privacy of the parent type, except
-- if the parent scope is being analyzed because we are deriving a
-- completion.
if Is_Private_Type (Full_Parent)
and then Present (Underlying_Full_View (Full_Parent))
and then (Is_Completion or else In_Private_Part (Par_Scope))
then
Full_Parent := Underlying_Full_View (Full_Parent);
end if;
-- For private, record, concurrent, access and almost all enumeration
-- types, the derivation from the full view requires a fully-fledged
-- declaration. In the other cases, just use an itype.
if Is_Private_Type (Full_Parent)
or else Is_Record_Type (Full_Parent)
or else Is_Concurrent_Type (Full_Parent)
or else Is_Access_Type (Full_Parent)
or else
(Is_Enumeration_Type (Full_Parent)
and then not Is_Standard_Character_Type (Full_Parent)
and then not Is_Generic_Type (Root_Type (Full_Parent)))
then
-- Copy and adjust declaration to provide a completion for what
-- is originally a private declaration. Indicate that full view
-- is internally generated.
Set_Comes_From_Source (Full_N, False);
Set_Comes_From_Source (Full_Der, False);
Set_Parent (Full_Der, Full_N);
Set_Defining_Identifier (Full_N, Full_Der);
-- If there are no constraints, adjust the subtype mark
if Nkind (Subtype_Indication (Type_Definition (Full_N))) /=
N_Subtype_Indication
then
Set_Subtype_Indication
(Type_Definition (Full_N),
New_Occurrence_Of (Full_Parent, Sloc (Full_N)));
end if;
Insert_After (N, Full_N);
-- Build full view of derived type from full view of parent which
-- is now installed. Subprograms have been derived on the partial
-- view, the completion does not derive them anew.
if Is_Record_Type (Full_Parent) then
-- If parent type is tagged, the completion inherits the proper
-- primitive operations.
if Is_Tagged_Type (Parent_Type) then
Build_Derived_Record_Type
(Full_N, Full_Parent, Full_Der, Derive_Subps);
else
Build_Derived_Record_Type
(Full_N, Full_Parent, Full_Der, Derive_Subps => False);
end if;
else
-- If the parent type is private, this is not a completion and
-- we build the full derivation recursively as a completion.
Build_Derived_Type
(Full_N, Full_Parent, Full_Der,
Is_Completion => Is_Private_Type (Full_Parent),
Derive_Subps => False);
end if;
-- The full declaration has been introduced into the tree and
-- processed in the step above. It should not be analyzed again
-- (when encountered later in the current list of declarations)
-- to prevent spurious name conflicts. The full entity remains
-- invisible.
Set_Analyzed (Full_N);
else
Full_Der :=
Make_Defining_Identifier (Sloc (Derived_Type),
Chars => Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, N);
Build_Derived_Type
(N, Full_Parent, Full_Der,
Is_Completion => False, Derive_Subps => False);
end if;
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Scope (Full_Der, Scope (Derived_Type));
Set_Is_First_Subtype (Full_Der, Is_First_Subtype (Derived_Type));
Set_Has_Size_Clause (Full_Der, False);
Set_Has_Alignment_Clause (Full_Der, False);
Set_Has_Delayed_Freeze (Full_Der);
Set_Is_Frozen (Full_Der, False);
Set_Freeze_Node (Full_Der, Empty);
Set_Depends_On_Private (Full_Der, Has_Private_Component (Full_Der));
Set_Is_Public (Full_Der, Is_Public (Derived_Type));
-- The convention on the base type may be set in the private part
-- and not propagated to the subtype until later, so we obtain the
-- convention from the base type of the parent.
Set_Convention (Full_Der, Convention (Base_Type (Full_Parent)));
end Copy_And_Build;
-- Start of processing for Build_Derived_Private_Type
begin
if Is_Tagged_Type (Parent_Type) then
Full_P := Full_View (Parent_Type);
-- A type extension of a type with unknown discriminants is an
-- indefinite type that the back-end cannot handle directly.
-- We treat it as a private type, and build a completion that is
-- derived from the full view of the parent, and hopefully has
-- known discriminants.
-- If the full view of the parent type has an underlying record view,
-- use it to generate the underlying record view of this derived type
-- (required for chains of derivations with unknown discriminants).
-- Minor optimization: we avoid the generation of useless underlying
-- record view entities if the private type declaration has unknown
-- discriminants but its corresponding full view has no
-- discriminants.
if Has_Unknown_Discriminants (Parent_Type)
and then Present (Full_P)
and then (Has_Discriminants (Full_P)
or else Present (Underlying_Record_View (Full_P)))
and then not In_Open_Scopes (Par_Scope)
and then Expander_Active
then
declare
Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
New_Ext : constant Node_Id :=
Copy_Separate_Tree
(Record_Extension_Part (Type_Definition (N)));
Decl : Node_Id;
begin
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
-- Build anonymous completion, as a derivation from the full
-- view of the parent. This is not a completion in the usual
-- sense, because the current type is not private.
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Full_Der,
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Subtype_Indication =>
New_Copy_Tree
(Subtype_Indication (Type_Definition (N))),
Record_Extension_Part => New_Ext));
-- If the parent type has an underlying record view, use it
-- here to build the new underlying record view.
if Present (Underlying_Record_View (Full_P)) then
pragma Assert
(Nkind (Subtype_Indication (Type_Definition (Decl)))
= N_Identifier);
Set_Entity (Subtype_Indication (Type_Definition (Decl)),
Underlying_Record_View (Full_P));
end if;
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Insert_Before (N, Decl);
-- Mark entity as an underlying record view before analysis,
-- to avoid generating the list of its primitive operations
-- (which is not really required for this entity) and thus
-- prevent spurious errors associated with missing overriding
-- of abstract primitives (overridden only for Derived_Type).
Mutate_Ekind (Full_Der, E_Record_Type);
Set_Is_Underlying_Record_View (Full_Der);
Set_Default_SSO (Full_Der);
Set_No_Reordering (Full_Der, No_Component_Reordering);
Analyze (Decl);
pragma Assert (Has_Discriminants (Full_Der)
and then not Has_Unknown_Discriminants (Full_Der));
Uninstall_Declarations (Par_Scope);
-- Freeze the underlying record view, to prevent generation of
-- useless dispatching information, which is simply shared with
-- the real derived type.
Set_Is_Frozen (Full_Der);
-- If the derived type has access discriminants, create
-- references to their anonymous types now, to prevent
-- back-end problems when their first use is in generated
-- bodies of primitives.
declare
E : Entity_Id;
begin
E := First_Entity (Full_Der);
while Present (E) loop
if Ekind (E) = E_Discriminant
and then Ekind (Etype (E)) = E_Anonymous_Access_Type
then
Build_Itype_Reference (Etype (E), Decl);
end if;
Next_Entity (E);
end loop;
end;
-- Set up links between real entity and underlying record view
Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
end;
-- If discriminants are known, build derived record
else
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
end if;
return;
elsif Has_Discriminants (Parent_Type) then
-- Build partial view of derived type from partial view of parent.
-- This must be done before building the full derivation because the
-- second derivation will modify the discriminants of the first and
-- the discriminants are chained with the rest of the components in
-- the full derivation.
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
-- Build the full derivation if this is not the anonymous derived
-- base type created by Build_Derived_Record_Type in the constrained
-- case (see point 5. of its head comment) since we build it for the
-- derived subtype.
if Present (Available_Full_View (Parent_Type))
and then not Is_Itype (Derived_Type)
then
declare
Der_Base : constant Entity_Id := Base_Type (Derived_Type);
Discr : Entity_Id;
Last_Discr : Entity_Id;
begin
-- If this is not a completion, construct the implicit full
-- view by deriving from the full view of the parent type.
-- But if this is a completion, the derived private type
-- being built is a full view and the full derivation can
-- only be its underlying full view.
Build_Full_Derivation;
if not Is_Completion then
Set_Full_View (Derived_Type, Full_Der);
else
Set_Underlying_Full_View (Derived_Type, Full_Der);
Set_Is_Underlying_Full_View (Full_Der);
end if;
if not Is_Base_Type (Derived_Type) then
Set_Full_View (Der_Base, Base_Type (Full_Der));
end if;
-- Copy the discriminant list from full view to the partial
-- view (base type and its subtype). Gigi requires that the
-- partial and full views have the same discriminants.
-- Note that since the partial view points to discriminants
-- in the full view, their scope will be that of the full
-- view. This might cause some front end problems and need
-- adjustment???
Discr := First_Discriminant (Base_Type (Full_Der));
Set_First_Entity (Der_Base, Discr);
loop
Last_Discr := Discr;
Next_Discriminant (Discr);
exit when No (Discr);
end loop;
Set_Last_Entity (Der_Base, Last_Discr);
Set_First_Entity (Derived_Type, First_Entity (Der_Base));
Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
end;
end if;
elsif Present (Available_Full_View (Parent_Type))
and then Has_Discriminants (Available_Full_View (Parent_Type))
then
if Has_Unknown_Discriminants (Parent_Type)
and then Nkind (Subtype_Indication (Type_Definition (N))) =
N_Subtype_Indication
then
Error_Msg_N
("cannot constrain type with unknown discriminants",
Subtype_Indication (Type_Definition (N)));
return;
end if;
-- If this is not a completion, construct the implicit full view by
-- deriving from the full view of the parent type. But if this is a
-- completion, the derived private type being built is a full view
-- and the full derivation can only be its underlying full view.
Build_Full_Derivation;
if not Is_Completion then
Set_Full_View (Derived_Type, Full_Der);
else
Set_Underlying_Full_View (Derived_Type, Full_Der);
Set_Is_Underlying_Full_View (Full_Der);
end if;
-- In any case, the primitive operations are inherited from the
-- parent type, not from the internal full view.
Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
if Derive_Subps then
-- Initialize the list of primitive operations to an empty list,
-- to cover tagged types as well as untagged types. For untagged
-- types this is used either to analyze the call as legal when
-- Extensions_Allowed is True, or to issue a better error message
-- otherwise.
Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
Set_Stored_Constraint (Derived_Type, No_Elist);
Set_Is_Constrained
(Derived_Type, Is_Constrained (Available_Full_View (Parent_Type)));
else
-- Untagged type, No discriminants on either view
if Nkind (Subtype_Indication (Type_Definition (N))) =
N_Subtype_Indication
then
Error_Msg_N
("illegal constraint on type without discriminants", N);
end if;
if Present (Discriminant_Specifications (N))
and then Present (Available_Full_View (Parent_Type))
and then not Is_Tagged_Type (Available_Full_View (Parent_Type))
then
Error_Msg_N ("cannot add discriminants to untagged type", N);
end if;
Set_Stored_Constraint (Derived_Type, No_Elist);
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
Set_Is_Controlled_Active
(Derived_Type, Is_Controlled_Active (Parent_Type));
Set_Disable_Controlled
(Derived_Type, Disable_Controlled (Parent_Type));
Set_Has_Controlled_Component
(Derived_Type, Has_Controlled_Component (Parent_Type));
-- Direct controlled types do not inherit Finalize_Storage_Only flag
if not Is_Controlled (Parent_Type) then
Set_Finalize_Storage_Only
(Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
end if;
-- If this is not a completion, construct the implicit full view by
-- deriving from the full view of the parent type. But if this is a
-- completion, the derived private type being built is a full view
-- and the full derivation can only be its underlying full view.
-- ??? If the parent type is untagged private and its completion is
-- tagged, this mechanism will not work because we cannot derive from
-- the tagged full view unless we have an extension.
if Present (Available_Full_View (Parent_Type))
and then not Is_Tagged_Type (Available_Full_View (Parent_Type))
and then not Error_Posted (N)
then
Build_Full_Derivation;
if not Is_Completion then
Set_Full_View (Derived_Type, Full_Der);
else
Set_Underlying_Full_View (Derived_Type, Full_Der);
Set_Is_Underlying_Full_View (Full_Der);
end if;
end if;
end if;
Set_Has_Unknown_Discriminants (Derived_Type,
Has_Unknown_Discriminants (Parent_Type));
if Is_Private_Type (Derived_Type) then
Set_Private_Dependents (Derived_Type, New_Elmt_List);
end if;
-- If the parent base type is in scope, add the derived type to its
-- list of private dependents, because its full view may become
-- visible subsequently (in a nested private part, a body, or in a
-- further child unit).
if Is_Private_Type (Par_Base) and then In_Open_Scopes (Par_Scope) then
Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
-- Check for unusual case where a type completed by a private
-- derivation occurs within a package nested in a child unit, and
-- the parent is declared in an ancestor.
if Is_Child_Unit (Scope (Current_Scope))
and then Is_Completion
and then In_Private_Part (Current_Scope)
and then Scope (Parent_Type) /= Current_Scope
-- Note that if the parent has a completion in the private part,
-- (which is itself a derivation from some other private type)
-- it is that completion that is visible, there is no full view
-- available, and no special processing is needed.
and then Present (Full_View (Parent_Type))
then
-- In this case, the full view of the parent type will become
-- visible in the body of the enclosing child, and only then will
-- the current type be possibly non-private. Build an underlying
-- full view that will be installed when the enclosing child body
-- is compiled.
if Present (Underlying_Full_View (Derived_Type)) then
Full_Der := Underlying_Full_View (Derived_Type);
else
Build_Full_Derivation;
Set_Underlying_Full_View (Derived_Type, Full_Der);
Set_Is_Underlying_Full_View (Full_Der);
end if;
-- The full view will be used to swap entities on entry/exit to
-- the body, and must appear in the entity list for the package.
Append_Entity (Full_Der, Scope (Derived_Type));
end if;
end if;
end Build_Derived_Private_Type;
-------------------------------
-- Build_Derived_Record_Type --
-------------------------------
-- 1. INTRODUCTION
-- Ideally we would like to use the same model of type derivation for
-- tagged and untagged record types. Unfortunately this is not quite
-- possible because the semantics of representation clauses is different
-- for tagged and untagged records under inheritance. Consider the
-- following:
-- type R (...) is [tagged] record ... end record;
-- type T (...) is new R (...) [with ...];
-- The representation clauses for T can specify a completely different
-- record layout from R's. Hence the same component can be placed in two
-- very different positions in objects of type T and R. If R and T are
-- tagged types, representation clauses for T can only specify the layout
-- of non inherited components, thus components that are common in R and T
-- have the same position in objects of type R and T.
-- This has two implications. The first is that the entire tree for R's
-- declaration needs to be copied for T in the untagged case, so that T
-- can be viewed as a record type of its own with its own representation
-- clauses. The second implication is the way we handle discriminants.
-- Specifically, in the untagged case we need a way to communicate to Gigi
-- what are the real discriminants in the record, while for the semantics
-- we need to consider those introduced by the user to rename the
-- discriminants in the parent type. This is handled by introducing the
-- notion of stored discriminants. See below for more.
-- Fortunately the way regular components are inherited can be handled in
-- the same way in tagged and untagged types.
-- To complicate things a bit more the private view of a private extension
-- cannot be handled in the same way as the full view (for one thing the
-- semantic rules are somewhat different). We will explain what differs
-- below.
-- 2. DISCRIMINANTS UNDER INHERITANCE
-- The semantic rules governing the discriminants of derived types are
-- quite subtle.
-- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
-- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
-- If parent type has discriminants, then the discriminants that are
-- declared in the derived type are [3.4 (11)]:
-- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
-- there is one;
-- o Otherwise, each discriminant of the parent type (implicitly declared
-- in the same order with the same specifications). In this case, the
-- discriminants are said to be "inherited", or if unknown in the parent
-- are also unknown in the derived type.
-- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
-- o The parent subtype must be constrained;
-- o If the parent type is not a tagged type, then each discriminant of
-- the derived type must be used in the constraint defining a parent
-- subtype. [Implementation note: This ensures that the new discriminant
-- can share storage with an existing discriminant.]
-- For the derived type each discriminant of the parent type is either
-- inherited, constrained to equal some new discriminant of the derived
-- type, or constrained to the value of an expression.
-- When inherited or constrained to equal some new discriminant, the
-- parent discriminant and the discriminant of the derived type are said
-- to "correspond".
-- If a discriminant of the parent type is constrained to a specific value
-- in the derived type definition, then the discriminant is said to be
-- "specified" by that derived type definition.
-- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
-- We have spoken about stored discriminants in point 1 (introduction)
-- above. There are two sorts of stored discriminants: implicit and
-- explicit. As long as the derived type inherits the same discriminants as
-- the root record type, stored discriminants are the same as regular
-- discriminants, and are said to be implicit. However, if any discriminant
-- in the root type was renamed in the derived type, then the derived
-- type will contain explicit stored discriminants. Explicit stored
-- discriminants are discriminants in addition to the semantically visible
-- discriminants defined for the derived type. Stored discriminants are
-- used by Gigi to figure out what are the physical discriminants in
-- objects of the derived type (see precise definition in einfo.ads).
-- As an example, consider the following:
-- type R (D1, D2, D3 : Int) is record ... end record;
-- type T1 is new R;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
-- type T3 is new T2;
-- type T4 (Y : Int) is new T3 (Y, 99);
-- The following table summarizes the discriminants and stored
-- discriminants in R and T1 through T4:
-- Type Discrim Stored Discrim Comment
-- R (D1, D2, D3) (D1, D2, D3) Stored discrims implicit in R
-- T1 (D1, D2, D3) (D1, D2, D3) Stored discrims implicit in T1
-- T2 (X1, X2) (D1, D2, D3) Stored discrims EXPLICIT in T2
-- T3 (X1, X2) (D1, D2, D3) Stored discrims EXPLICIT in T3
-- T4 (Y) (D1, D2, D3) Stored discrims EXPLICIT in T4
-- Field Corresponding_Discriminant (abbreviated CD below) allows us to
-- find the corresponding discriminant in the parent type, while
-- Original_Record_Component (abbreviated ORC below) the actual physical
-- component that is renamed. Finally the field Is_Completely_Hidden
-- (abbreviated ICH below) is set for all explicit stored discriminants
-- (see einfo.ads for more info). For the above example this gives:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R itself no
-- D2 in T1 D2 in R itself no
-- D3 in T1 D3 in R itself no
-- X1 in T2 D3 in T1 D3 in T2 no
-- X2 in T2 D1 in T1 D1 in T2 no
-- D1 in T2 empty itself yes
-- D2 in T2 empty itself yes
-- D3 in T2 empty itself yes
-- X1 in T3 X1 in T2 D3 in T3 no
-- X2 in T3 X2 in T2 D1 in T3 no
-- D1 in T3 empty itself yes
-- D2 in T3 empty itself yes
-- D3 in T3 empty itself yes
-- Y in T4 X1 in T3 D3 in T4 no
-- D1 in T4 empty itself yes
-- D2 in T4 empty itself yes
-- D3 in T4 empty itself yes
-- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
-- Type derivation for tagged types is fairly straightforward. If no
-- discriminants are specified by the derived type, these are inherited
-- from the parent. No explicit stored discriminants are ever necessary.
-- The only manipulation that is done to the tree is that of adding a
-- _parent field with parent type and constrained to the same constraint
-- specified for the parent in the derived type definition. For instance:
-- type R (D1, D2, D3 : Int) is tagged record ... end record;
-- type T1 is new R with null record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
-- are changed into:
-- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
-- _parent : R (D1, D2, D3);
-- end record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
-- _parent : T1 (X2, 88, X1);
-- end record;
-- The discriminants actually present in R, T1 and T2 as well as their CD,
-- ORC and ICH fields are:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R D1 in R no
-- D2 in T1 D2 in R D2 in R no
-- D3 in T1 D3 in R D3 in R no
-- X1 in T2 D3 in T1 D3 in R no
-- X2 in T2 D1 in T1 D1 in R no
-- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
--
-- Regardless of whether we dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
--
-- type T is new R (...) [with ...];
-- or
-- subtype S is R (...);
-- type T is new S [with ...];
-- into
-- type BT is new R [with ...];
-- subtype T is BT (...);
--
-- That is, the base derived type is constrained only if it has no
-- discriminants. The reason for doing this is that GNAT's semantic model
-- assumes that a base type with discriminants is unconstrained.
--
-- Note that, strictly speaking, the above transformation is not always
-- correct. Consider for instance the following excerpt from ACVC b34011a:
--
-- procedure B34011A is
-- type REC (D : integer := 0) is record
-- I : Integer;
-- end record;
-- package P is
-- type T6 is new Rec;
-- function F return T6;
-- end P;
-- use P;
-- package Q6 is
-- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
-- end Q6;
--
-- The definition of Q6.U is illegal. However transforming Q6.U into
-- type BaseU is new T6;
-- subtype U is BaseU (Q6.F.I)
-- turns U into a legal subtype, which is incorrect. To avoid this problem
-- we always analyze the constraint (in this case (Q6.F.I)) before applying
-- the transformation described above.
-- There is another instance where the above transformation is incorrect.
-- Consider:
-- package Pack is
-- type Base (D : Integer) is tagged null record;
-- procedure P (X : Base);
-- type Der is new Base (2) with null record;
-- procedure P (X : Der);
-- end Pack;
-- Then the above transformation turns this into
-- type Der_Base is new Base with null record;
-- -- procedure P (X : Base) is implicitly inherited here
-- -- as procedure P (X : Der_Base).
-- subtype Der is Der_Base (2);
-- procedure P (X : Der);
-- -- The overriding of P (X : Der_Base) is illegal since we
-- -- have a parameter conformance problem.
-- To get around this problem, after having semantically processed Der_Base
-- and the rewritten subtype declaration for Der, we copy Der_Base field
-- Discriminant_Constraint from Der so that when parameter conformance is
-- checked when P is overridden, no semantic errors are flagged.
-- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
-- Regardless of whether we are dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
-- type R (D1, .., Dn : ...) is [tagged] record ...;
-- type T is new R [with ...];
-- into
-- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
-- The reason for such transformation is that it allows us to implement a
-- very clean form of component inheritance as explained below.
-- Note that this transformation is not achieved by direct tree rewriting
-- and manipulation, but rather by redoing the semantic actions that the
-- above transformation will entail. This is done directly in routine
-- Inherit_Components.
-- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
-- In both tagged and untagged derived types, regular non discriminant
-- components are inherited in the derived type from the parent type. In
-- the absence of discriminants component, inheritance is straightforward
-- as components can simply be copied from the parent.
-- If the parent has discriminants, inheriting components constrained with
-- these discriminants requires caution. Consider the following example:
-- type R (D1, D2 : Positive) is [tagged] record
-- S : String (D1 .. D2);
-- end record;
-- type T1 is new R [with null record];
-- type T2 (X : positive) is new R (1, X) [with null record];
-- As explained in 6. above, T1 is rewritten as
-- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
-- which makes the treatment for T1 and T2 identical.
-- What we want when inheriting S, is that references to D1 and D2 in R are
-- replaced with references to their correct constraints, i.e. D1 and D2 in
-- T1 and 1 and X in T2. So all R's discriminant references are replaced
-- with either discriminant references in the derived type or expressions.
-- This replacement is achieved as follows: before inheriting R's
-- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
-- created in the scope of T1 (resp. scope of T2) so that discriminants D1
-- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
-- For T2, for instance, this has the effect of replacing String (D1 .. D2)
-- by String (1 .. X).
-- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
-- We explain here the rules governing private type extensions relevant to
-- type derivation. These rules are explained on the following example:
-- type D [(...)] is new A [(...)] with private; <-- partial view
-- type D [(...)] is new P [(...)] with null record; <-- full view
-- Type A is called the ancestor subtype of the private extension.
-- Type P is the parent type of the full view of the private extension. It
-- must be A or a type derived from A.
-- The rules concerning the discriminants of private type extensions are
-- [7.3(10-13)]:
-- o If a private extension inherits known discriminants from the ancestor
-- subtype, then the full view must also inherit its discriminants from
-- the ancestor subtype and the parent subtype of the full view must be
-- constrained if and only if the ancestor subtype is constrained.
-- o If a partial view has unknown discriminants, then the full view may
-- define a definite or an indefinite subtype, with or without
-- discriminants.
-- o If a partial view has neither known nor unknown discriminants, then
-- the full view must define a definite subtype.
-- o If the ancestor subtype of a private extension has constrained
-- discriminants, then the parent subtype of the full view must impose a
-- statically matching constraint on those discriminants.
-- This means that only the following forms of private extensions are
-- allowed:
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- If A has no discriminants than P has no discriminants, otherwise P must
-- inherit A's discriminants.
-- type D is new A (...) with private; <-- partial view
-- type D is new P (:::) with null record; <-- full view
-- P must inherit A's discriminants and (...) and (:::) must statically
-- match.
-- subtype A is R (...);
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- P must have inherited R's discriminants and must be derived from A or
-- any of its subtypes.
-- type D (..) is new A with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- No specific constraints on P's discriminants or constraint (:::).
-- Note that A can be unconstrained, but the parent subtype P must either
-- be constrained or (:::) must be present.
-- type D (..) is new A [(...)] with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- P's constraints on A's discriminants must statically match those
-- imposed by (...).
-- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
-- The full view of a private extension is handled exactly as described
-- above. The model chose for the private view of a private extension is
-- the same for what concerns discriminants (i.e. they receive the same
-- treatment as in the tagged case). However, the private view of the
-- private extension always inherits the components of the parent base,
-- without replacing any discriminant reference. Strictly speaking this is
-- incorrect. However, Gigi never uses this view to generate code so this
-- is a purely semantic issue. In theory, a set of transformations similar
-- to those given in 5. and 6. above could be applied to private views of
-- private extensions to have the same model of component inheritance as
-- for non private extensions. However, this is not done because it would
-- further complicate private type processing. Semantically speaking, this
-- leaves us in an uncomfortable situation. As an example consider:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type T is new R (1) with null record;
-- end;
-- This is transformed into:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type BaseT is new R with null record;
-- subtype T is BaseT (1);
-- end;
-- (strictly speaking the above is incorrect Ada)
-- From the semantic standpoint the private view of private extension T
-- should be flagged as constrained since one can clearly have
--
-- Obj : T;
--
-- in a unit withing Pack. However, when deriving subprograms for the
-- private view of private extension T, T must be seen as unconstrained
-- since T has discriminants (this is a constraint of the current
-- subprogram derivation model). Thus, when processing the private view of
-- a private extension such as T, we first mark T as unconstrained, we
-- process it, we perform program derivation and just before returning from
-- Build_Derived_Record_Type we mark T as constrained.
-- ??? Are there are other uncomfortable cases that we will have to
-- deal with.
-- 10. RECORD_TYPE_WITH_PRIVATE complications
-- Types that are derived from a visible record type and have a private
-- extension present other peculiarities. They behave mostly like private
-- types, but if they have primitive operations defined, these will not
-- have the proper signatures for further inheritance, because other
-- primitive operations will use the implicit base that we define for
-- private derivations below. This affect subprogram inheritance (see
-- Derive_Subprograms for details). We also derive the implicit base from
-- the base type of the full view, so that the implicit base is a record
-- type and not another private type, This avoids infinite loops.
procedure Build_Derived_Record_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Derive_Subps : Boolean := True)
is
Discriminant_Specs : constant Boolean :=
Present (Discriminant_Specifications (N));
Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
Loc : constant Source_Ptr := Sloc (N);
Private_Extension : constant Boolean :=
Nkind (N) = N_Private_Extension_Declaration;
Assoc_List : Elist_Id;
Constraint_Present : Boolean;
Constrs : Elist_Id;
Discrim : Entity_Id;
Indic : Node_Id;
Inherit_Discrims : Boolean := False;
Last_Discrim : Entity_Id;
New_Base : Entity_Id;
New_Decl : Node_Id;
New_Discrs : Elist_Id;
New_Indic : Node_Id;
Parent_Base : Entity_Id;
Save_Etype : Entity_Id;
Save_Discr_Constr : Elist_Id;
Save_Next_Entity : Entity_Id;
Type_Def : Node_Id;
Discs : Elist_Id := New_Elmt_List;
-- An empty Discs list means that there were no constraints in the
-- subtype indication or that there was an error processing it.
procedure Check_Generic_Ancestors;
-- In Ada 2005 (AI-344), the restriction that a derived tagged type
-- cannot be declared at a deeper level than its parent type is
-- removed. The check on derivation within a generic body is also
-- relaxed, but there's a restriction that a derived tagged type
-- cannot be declared in a generic body if it's derived directly
-- or indirectly from a formal type of that generic. This applies
-- to progenitors as well.
-----------------------------
-- Check_Generic_Ancestors --
-----------------------------
procedure Check_Generic_Ancestors is
Ancestor_Type : Entity_Id;
Intf_List : List_Id;
Intf_Name : Node_Id;
procedure Check_Ancestor;
-- For parent and progenitors.
--------------------
-- Check_Ancestor --
--------------------
procedure Check_Ancestor is
begin
-- If the derived type does have a formal type as an ancestor
-- then it's an error if the derived type is declared within
-- the body of the generic unit that declares the formal type
-- in its generic formal part. It's sufficient to check whether
-- the ancestor type is declared inside the same generic body
-- as the derived type (such as within a nested generic spec),
-- in which case the derivation is legal. If the formal type is
-- declared outside of that generic body, then it's certain
-- that the derived type is declared within the generic body
-- of the generic unit declaring the formal type.
if Is_Generic_Type (Ancestor_Type)
and then Enclosing_Generic_Body (Ancestor_Type) /=
Enclosing_Generic_Body (Derived_Type)
then
Error_Msg_NE
("ancestor type& is formal type of enclosing"
& " generic unit (RM 3.9.1 (4/2))",
Indic, Ancestor_Type);
end if;
end Check_Ancestor;
begin
if Nkind (N) = N_Private_Extension_Declaration then
Intf_List := Interface_List (N);
else
Intf_List := Interface_List (Type_Definition (N));
end if;
if Present (Enclosing_Generic_Body (Derived_Type)) then
Ancestor_Type := Parent_Type;
while not Is_Generic_Type (Ancestor_Type)
and then Etype (Ancestor_Type) /= Ancestor_Type
loop
Ancestor_Type := Etype (Ancestor_Type);
end loop;
Check_Ancestor;
if Present (Intf_List) then
Intf_Name := First (Intf_List);
while Present (Intf_Name) loop
Ancestor_Type := Entity (Intf_Name);
Check_Ancestor;
Next (Intf_Name);
end loop;
end if;
end if;
end Check_Generic_Ancestors;
-- Start of processing for Build_Derived_Record_Type
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Present (Full_View (Parent_Type))
and then Has_Discriminants (Parent_Type)
then
Parent_Base := Base_Type (Full_View (Parent_Type));
else
Parent_Base := Base_Type (Parent_Type);
end if;
-- If the parent type is declared as a subtype of another private
-- type with inherited discriminants, its generated base type is
-- itself a record subtype. To further inherit the constraint we
-- need to use its own base to have an unconstrained type on which
-- to apply the inherited constraint.
if Ekind (Parent_Base) = E_Record_Subtype then
Parent_Base := Base_Type (Parent_Base);
end if;
-- AI05-0115: if this is a derivation from a private type in some
-- other scope that may lead to invisible components for the derived
-- type, mark it accordingly.
if Is_Private_Type (Parent_Type) then
if Scope (Parent_Base) = Scope (Derived_Type) then
null;
elsif In_Open_Scopes (Scope (Parent_Base))
and then In_Private_Part (Scope (Parent_Base))
then
null;
else
Set_Has_Private_Ancestor (Derived_Type);
end if;
else
Set_Has_Private_Ancestor
(Derived_Type, Has_Private_Ancestor (Parent_Type));
end if;
-- Before we start the previously documented transformations, here is
-- little fix for size and alignment of tagged types. Normally when we
-- derive type D from type P, we copy the size and alignment of P as the
-- default for D, and in the absence of explicit representation clauses
-- for D, the size and alignment are indeed the same as the parent.
-- But this is wrong for tagged types, since fields may be added, and
-- the default size may need to be larger, and the default alignment may
-- need to be larger.
-- We therefore reset the size and alignment fields in the tagged case.
-- Note that the size and alignment will in any case be at least as
-- large as the parent type (since the derived type has a copy of the
-- parent type in the _parent field)
-- The type is also marked as being tagged here, which is needed when
-- processing components with a self-referential anonymous access type
-- in the call to Check_Anonymous_Access_Components below. Note that
-- this flag is also set later on for completeness.
if Is_Tagged then
Set_Is_Tagged_Type (Derived_Type);
Reinit_Size_Align (Derived_Type);
end if;
-- STEP 0a: figure out what kind of derived type declaration we have
if Private_Extension then
Type_Def := N;
Mutate_Ekind (Derived_Type, E_Record_Type_With_Private);
Set_Default_SSO (Derived_Type);
Set_No_Reordering (Derived_Type, No_Component_Reordering);
else
Type_Def := Type_Definition (N);
-- Ekind (Parent_Base) is not necessarily E_Record_Type since
-- Parent_Base can be a private type or private extension. However,
-- for tagged types with an extension the newly added fields are
-- visible and hence the Derived_Type is always an E_Record_Type.
-- (except that the parent may have its own private fields).
-- For untagged types we preserve the Ekind of the Parent_Base.
if Present (Record_Extension_Part (Type_Def)) then
Mutate_Ekind (Derived_Type, E_Record_Type);
Set_Default_SSO (Derived_Type);
Set_No_Reordering (Derived_Type, No_Component_Reordering);
-- Create internal access types for components with anonymous
-- access types.
if Ada_Version >= Ada_2005 then
Check_Anonymous_Access_Components
(N, Derived_Type, Derived_Type,
Component_List (Record_Extension_Part (Type_Def)));
end if;
else
Mutate_Ekind (Derived_Type, Ekind (Parent_Base));
end if;
end if;
-- Indic can either be an N_Identifier if the subtype indication
-- contains no constraint or an N_Subtype_Indication if the subtype
-- indication has a constraint. In either case it can include an
-- interface list.
Indic := Subtype_Indication (Type_Def);
Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
-- Check that the type has visible discriminants. The type may be
-- a private type with unknown discriminants whose full view has
-- discriminants which are invisible.
if Constraint_Present then
if not Has_Discriminants (Parent_Base)
or else
(Has_Unknown_Discriminants (Parent_Base)
and then Is_Private_Type (Parent_Base))
then
Error_Msg_N
("invalid constraint: type has no discriminant",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
elsif Is_Constrained (Parent_Type) then
Error_Msg_N
("invalid constraint: parent type is already constrained",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
end if;
end if;
-- STEP 0b: If needed, apply transformation given in point 5. above
if not Private_Extension
and then Has_Discriminants (Parent_Type)
and then not Discriminant_Specs
and then (Is_Constrained (Parent_Type) or else Constraint_Present)
then
-- First, we must analyze the constraint (see comment in point 5.)
-- The constraint may come from the subtype indication of the full
-- declaration.
if Constraint_Present then
New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
-- If there is no explicit constraint, there might be one that is
-- inherited from a constrained parent type. In that case verify that
-- it conforms to the constraint in the partial view. In perverse
-- cases the parent subtypes of the partial and full view can have
-- different constraints.
elsif Present (Stored_Constraint (Parent_Type)) then
New_Discrs := Stored_Constraint (Parent_Type);
else
New_Discrs := No_Elist;
end if;
if Has_Discriminants (Derived_Type)
and then Has_Private_Declaration (Derived_Type)
and then Present (Discriminant_Constraint (Derived_Type))
and then Present (New_Discrs)
then
-- Verify that constraints of the full view statically match
-- those given in the partial view.
declare
C1, C2 : Elmt_Id;
begin
C1 := First_Elmt (New_Discrs);
C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
while Present (C1) and then Present (C2) loop
if Fully_Conformant_Expressions (Node (C1), Node (C2))
or else
(Is_OK_Static_Expression (Node (C1))
and then Is_OK_Static_Expression (Node (C2))
and then
Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
then
null;
else
if Constraint_Present then
Error_Msg_N
("constraint not conformant to previous declaration",
Node (C1));
else
Error_Msg_N
("constraint of full view is incompatible "
& "with partial view", N);
end if;
end if;
Next_Elmt (C1);
Next_Elmt (C2);
end loop;
end;
end if;
-- Insert and analyze the declaration for the unconstrained base type
New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
New_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => New_Base,
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Abstract_Present => Abstract_Present (Type_Def),
Limited_Present => Limited_Present (Type_Def),
Subtype_Indication =>
New_Occurrence_Of (Parent_Base, Loc),
Record_Extension_Part =>
Relocate_Node (Record_Extension_Part (Type_Def)),
Interface_List => Interface_List (Type_Def)));
Set_Parent (New_Decl, Parent (N));
Mark_Rewrite_Insertion (New_Decl);
Insert_Before (N, New_Decl);
-- In the extension case, make sure ancestor is frozen appropriately
-- (see also non-discriminated case below).
if Present (Record_Extension_Part (Type_Def))
or else Is_Interface (Parent_Base)
then
Freeze_Before (New_Decl, Parent_Type);
end if;
-- Note that this call passes False for the Derive_Subps parameter
-- because subprogram derivation is deferred until after creating
-- the subtype (see below).
Build_Derived_Type
(New_Decl, Parent_Base, New_Base,
Is_Completion => False, Derive_Subps => False);
-- ??? This needs re-examination to determine whether the
-- above call can simply be replaced by a call to Analyze.
Set_Analyzed (New_Decl);
-- Insert and analyze the declaration for the constrained subtype
if Constraint_Present then
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint => Relocate_Node (Constraint (Indic)));
else
declare
Constr_List : constant List_Id := New_List;
C : Elmt_Id;
Expr : Node_Id;
begin
C := First_Elmt (Discriminant_Constraint (Parent_Type));
while Present (C) loop
Expr := Node (C);
-- It is safe here to call New_Copy_Tree since we called
-- Force_Evaluation on each constraint previously
-- in Build_Discriminant_Constraints.
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (C);
end loop;
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
end;
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication => New_Indic));
Analyze (N);
-- Derivation of subprograms must be delayed until the full subtype
-- has been established, to ensure proper overriding of subprograms
-- inherited by full types. If the derivations occurred as part of
-- the call to Build_Derived_Type above, then the check for type
-- conformance would fail because earlier primitive subprograms
-- could still refer to the full type prior the change to the new
-- subtype and hence would not match the new base type created here.
-- Subprograms are not derived, however, when Derive_Subps is False
-- (since otherwise there could be redundant derivations).
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
-- For tagged types the Discriminant_Constraint of the new base itype
-- is inherited from the first subtype so that no subtype conformance
-- problem arise when the first subtype overrides primitive
-- operations inherited by the implicit base type.
if Is_Tagged then
Set_Discriminant_Constraint
(New_Base, Discriminant_Constraint (Derived_Type));
end if;
return;
end if;
-- If we get here Derived_Type will have no discriminants or it will be
-- a discriminated unconstrained base type.
-- STEP 1a: perform preliminary actions/checks for derived tagged types
if Is_Tagged then
-- The parent type is frozen for non-private extensions (RM 13.14(7))
-- The declaration of a specific descendant of an interface type
-- freezes the interface type (RM 13.14).
if not Private_Extension or else Is_Interface (Parent_Base) then
Freeze_Before (N, Parent_Type);
end if;
if Ada_Version >= Ada_2005 then
Check_Generic_Ancestors;
elsif Type_Access_Level (Derived_Type) /=
Type_Access_Level (Parent_Type)
and then not Is_Generic_Type (Derived_Type)
then
if Is_Controlled (Parent_Type) then
Error_Msg_N
("controlled type must be declared at the library level",
Indic);
else
Error_Msg_N
("type extension at deeper accessibility level than parent",
Indic);
end if;
else
declare
GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
begin
if Present (GB)
and then GB /= Enclosing_Generic_Body (Parent_Base)
then
Error_Msg_NE
("parent type of& must not be outside generic body"
& " (RM 3.9.1(4))",
Indic, Derived_Type);
end if;
end;
end if;
end if;
-- Ada 2005 (AI-251)
if Ada_Version >= Ada_2005 and then Is_Tagged then
-- "The declaration of a specific descendant of an interface type
-- freezes the interface type" (RM 13.14).
declare
Iface : Node_Id;
begin
Iface := First (Interface_List (Type_Def));
while Present (Iface) loop
Freeze_Before (N, Etype (Iface));
Next (Iface);
end loop;
end;
end if;
-- STEP 1b : preliminary cleanup of the full view of private types
-- If the type is already marked as having discriminants, then it's the
-- completion of a private type or private extension and we need to
-- retain the discriminants from the partial view if the current
-- declaration has Discriminant_Specifications so that we can verify
-- conformance. However, we must remove any existing components that
-- were inherited from the parent (and attached in Copy_And_Swap)
-- because the full type inherits all appropriate components anyway, and
-- we do not want the partial view's components interfering.
if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
Discrim := First_Discriminant (Derived_Type);
loop
Last_Discrim := Discrim;
Next_Discriminant (Discrim);
exit when No (Discrim);
end loop;
Set_Last_Entity (Derived_Type, Last_Discrim);
-- In all other cases wipe out the list of inherited components (even
-- inherited discriminants), it will be properly rebuilt here.
else
Set_First_Entity (Derived_Type, Empty);
Set_Last_Entity (Derived_Type, Empty);
end if;
-- STEP 1c: Initialize some flags for the Derived_Type
-- The following flags must be initialized here so that
-- Process_Discriminants can check that discriminants of tagged types do
-- not have a default initial value and that access discriminants are
-- only specified for limited records. For completeness, these flags are
-- also initialized along with all the other flags below.
-- AI-419: Limitedness is not inherited from an interface parent, so to
-- be limited in that case the type must be explicitly declared as
-- limited. However, task and protected interfaces are always limited.
if Limited_Present (Type_Def) then
Set_Is_Limited_Record (Derived_Type);
elsif Is_Limited_Record (Parent_Type)
or else (Present (Full_View (Parent_Type))
and then Is_Limited_Record (Full_View (Parent_Type)))
then
if not Is_Interface (Parent_Type)
or else Is_Concurrent_Interface (Parent_Type)
then
Set_Is_Limited_Record (Derived_Type);
end if;
end if;
-- STEP 2a: process discriminants of derived type if any
Push_Scope (Derived_Type);
if Discriminant_Specs then
Set_Has_Unknown_Discriminants (Derived_Type, False);
-- The following call initializes fields Has_Discriminants and
-- Discriminant_Constraint, unless we are processing the completion
-- of a private type declaration.
Check_Or_Process_Discriminants (N, Derived_Type);
-- For untagged types, the constraint on the Parent_Type must be
-- present and is used to rename the discriminants.
if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", Indic);
elsif not Is_Tagged and then not Constraint_Present then
Error_Msg_N
("discriminant constraint needed for derived untagged records",
Indic);
-- Otherwise the parent subtype must be constrained unless we have a
-- private extension.
elsif not Constraint_Present
and then not Private_Extension
and then not Is_Constrained (Parent_Type)
then
Error_Msg_N
("unconstrained type not allowed in this context", Indic);
elsif Constraint_Present then
-- The following call sets the field Corresponding_Discriminant
-- for the discriminants in the Derived_Type.
Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
-- For untagged types all new discriminants must rename
-- discriminants in the parent. For private extensions new
-- discriminants cannot rename old ones (implied by [7.3(13)]).
Discrim := First_Discriminant (Derived_Type);
while Present (Discrim) loop
if not Is_Tagged
and then No (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("new discriminants must constrain old ones", Discrim);
elsif Private_Extension
and then Present (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("only static constraints allowed for parent"
& " discriminants in the partial view", Indic);
exit;
end if;
-- If a new discriminant is used in the constraint, then its
-- subtype must be statically compatible with the subtype of
-- the parent discriminant (RM 3.7(15)).
if Present (Corresponding_Discriminant (Discrim)) then
Check_Constraining_Discriminant
(Discrim, Corresponding_Discriminant (Discrim));
end if;
Next_Discriminant (Discrim);
end loop;
-- Check whether the constraints of the full view statically
-- match those imposed by the parent subtype [7.3(13)].
if Present (Stored_Constraint (Derived_Type)) then
declare
C1, C2 : Elmt_Id;
begin
C1 := First_Elmt (Discs);
C2 := First_Elmt (Stored_Constraint (Derived_Type));
while Present (C1) and then Present (C2) loop
if not
Fully_Conformant_Expressions (Node (C1), Node (C2))
then
Error_Msg_N
("not conformant with previous declaration",
Node (C1));
end if;
Next_Elmt (C1);
Next_Elmt (C2);
end loop;
end;
end if;
end if;
-- STEP 2b: No new discriminants, inherit discriminants if any
else
if Private_Extension then
Set_Has_Unknown_Discriminants
(Derived_Type,
Has_Unknown_Discriminants (Parent_Type)
or else Unknown_Discriminants_Present (N));
-- The partial view of the parent may have unknown discriminants,
-- but if the full view has discriminants and the parent type is
-- in scope they must be inherited.
elsif Has_Unknown_Discriminants (Parent_Type)
and then
(not Has_Discriminants (Parent_Type)
or else not In_Open_Scopes (Scope (Parent_Base)))
then
Set_Has_Unknown_Discriminants (Derived_Type);
end if;
if not Has_Unknown_Discriminants (Derived_Type)
and then not Has_Unknown_Discriminants (Parent_Base)
and then Has_Discriminants (Parent_Type)
then
Inherit_Discrims := True;
Set_Has_Discriminants
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Base));
end if;
-- The following test is true for private types (remember
-- transformation 5. is not applied to those) and in an error
-- situation.
if Constraint_Present then
Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
end if;
-- For now mark a new derived type as constrained only if it has no
-- discriminants. At the end of Build_Derived_Record_Type we properly
-- set this flag in the case of private extensions. See comments in
-- point 9. just before body of Build_Derived_Record_Type.
Set_Is_Constrained
(Derived_Type,
not (Inherit_Discrims
or else Has_Unknown_Discriminants (Derived_Type)));
end if;
-- STEP 3: initialize fields of derived type
Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
Set_Stored_Constraint (Derived_Type, No_Elist);
-- Ada 2005 (AI-251): Private type-declarations can implement interfaces
-- but cannot be interfaces
if not Private_Extension
and then Ekind (Derived_Type) /= E_Private_Type
and then Ekind (Derived_Type) /= E_Limited_Private_Type
then
if Interface_Present (Type_Def) then
Analyze_Interface_Declaration (Derived_Type, Type_Def);
end if;
Set_Interfaces (Derived_Type, No_Elist);
end if;
-- Fields inherited from the Parent_Type
Set_Has_Specified_Layout
(Derived_Type, Has_Specified_Layout (Parent_Type));
Set_Is_Limited_Composite
(Derived_Type, Is_Limited_Composite (Parent_Type));
Set_Is_Private_Composite
(Derived_Type, Is_Private_Composite (Parent_Type));
if Is_Tagged_Type (Parent_Type) then
Set_No_Tagged_Streams_Pragma
(Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
end if;
-- Fields inherited from the Parent_Base
Set_Has_Controlled_Component
(Derived_Type, Has_Controlled_Component (Parent_Base));
Set_Has_Non_Standard_Rep
(Derived_Type, Has_Non_Standard_Rep (Parent_Base));
Set_Has_Primitive_Operations
(Derived_Type, Has_Primitive_Operations (Parent_Base));
-- Set fields for private derived types
if Is_Private_Type (Derived_Type) then
Set_Depends_On_Private (Derived_Type, True);
Set_Private_Dependents (Derived_Type, New_Elmt_List);
end if;
-- Inherit fields for non-private types. If this is the completion of a
-- derivation from a private type, the parent itself is private and the
-- attributes come from its full view, which must be present.
if Is_Record_Type (Derived_Type) then
declare
Parent_Full : Entity_Id;
begin
if Is_Private_Type (Parent_Base)
and then not Is_Record_Type (Parent_Base)
then
Parent_Full := Full_View (Parent_Base);
else
Parent_Full := Parent_Base;
end if;
Set_Component_Alignment
(Derived_Type, Component_Alignment (Parent_Full));
Set_C_Pass_By_Copy
(Derived_Type, C_Pass_By_Copy (Parent_Full));
Set_Has_Complex_Representation
(Derived_Type, Has_Complex_Representation (Parent_Full));
-- For untagged types, inherit the layout by default to avoid
-- costly changes of representation for type conversions.
if not Is_Tagged then
Set_Is_Packed (Derived_Type, Is_Packed (Parent_Full));
Set_No_Reordering (Derived_Type, No_Reordering (Parent_Full));
end if;
end;
end if;
-- Initialize the list of primitive operations to an empty list,
-- to cover tagged types as well as untagged types. For untagged
-- types this is used either to analyze the call as legal when
-- Extensions_Allowed is True, or to issue a better error message
-- otherwise.
Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
-- Set fields for tagged types
if Is_Tagged then
-- All tagged types defined in Ada.Finalization are controlled
if Chars (Scope (Derived_Type)) = Name_Finalization
and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
then
Set_Is_Controlled_Active (Derived_Type);
else
Set_Is_Controlled_Active
(Derived_Type, Is_Controlled_Active (Parent_Base));
end if;
-- Minor optimization: there is no need to generate the class-wide
-- entity associated with an underlying record view.
if not Is_Underlying_Record_View (Derived_Type) then
Make_Class_Wide_Type (Derived_Type);
end if;
Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def));
if Has_Discriminants (Derived_Type)
and then Constraint_Present
then
Set_Stored_Constraint
(Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
end if;
if Ada_Version >= Ada_2005 then
declare
Ifaces_List : Elist_Id;
begin
-- Checks rules 3.9.4 (13/2 and 14/2)
if Comes_From_Source (Derived_Type)
and then not Is_Private_Type (Derived_Type)
and then Is_Interface (Parent_Type)
and then not Is_Interface (Derived_Type)
then
if Is_Task_Interface (Parent_Type) then
Error_Msg_N
("(Ada 2005) task type required (RM 3.9.4 (13.2))",
Derived_Type);
elsif Is_Protected_Interface (Parent_Type) then
Error_Msg_N
("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
Derived_Type);
end if;
end if;
-- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
Check_Interfaces (N, Type_Def);
-- Ada 2005 (AI-251): Collect the list of progenitors that are
-- not already in the parents.
Collect_Interfaces
(T => Derived_Type,
Ifaces_List => Ifaces_List,
Exclude_Parents => True);
Set_Interfaces (Derived_Type, Ifaces_List);
-- If the derived type is the anonymous type created for
-- a declaration whose parent has a constraint, propagate
-- the interface list to the source type. This must be done
-- prior to the completion of the analysis of the source type
-- because the components in the extension may contain current
-- instances whose legality depends on some ancestor.
if Is_Itype (Derived_Type) then
declare
Def : constant Node_Id :=
Associated_Node_For_Itype (Derived_Type);
begin
if Present (Def)
and then Nkind (Def) = N_Full_Type_Declaration
then
Set_Interfaces
(Defining_Identifier (Def), Ifaces_List);
end if;
end;
end if;
-- A type extension is automatically Ghost when one of its
-- progenitors is Ghost (SPARK RM 6.9(9)). This property is
-- also inherited when the parent type is Ghost, but this is
-- done in Build_Derived_Type as the mechanism also handles
-- untagged derivations.
if Implements_Ghost_Interface (Derived_Type) then
Set_Is_Ghost_Entity (Derived_Type);
end if;
end;
end if;
end if;
-- STEP 4: Inherit components from the parent base and constrain them.
-- Apply the second transformation described in point 6. above.
if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
or else not Has_Discriminants (Parent_Type)
or else not Is_Constrained (Parent_Type)
then
Constrs := Discs;
else
Constrs := Discriminant_Constraint (Parent_Type);
end if;
Assoc_List :=
Inherit_Components
(N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
-- STEP 5a: Copy the parent record declaration for untagged types
Set_Has_Implicit_Dereference
(Derived_Type, Has_Implicit_Dereference (Parent_Type));
if not Is_Tagged then
-- Discriminant_Constraint (Derived_Type) has been properly
-- constructed. Save it and temporarily set it to Empty because we
-- do not want the call to New_Copy_Tree below to mess this list.
if Has_Discriminants (Derived_Type) then
Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
Set_Discriminant_Constraint (Derived_Type, No_Elist);
else
Save_Discr_Constr := No_Elist;
end if;
-- Save the Etype field of Derived_Type. It is correctly set now,
-- but the call to New_Copy tree may remap it to point to itself,
-- which is not what we want. Ditto for the Next_Entity field.
Save_Etype := Etype (Derived_Type);
Save_Next_Entity := Next_Entity (Derived_Type);
-- Assoc_List maps all stored discriminants in the Parent_Base to
-- stored discriminants in the Derived_Type. It is fundamental that
-- no types or itypes with discriminants other than the stored
-- discriminants appear in the entities declared inside
-- Derived_Type, since the back end cannot deal with it.
New_Decl :=
New_Copy_Tree
(Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
Copy_Dimensions_Of_Components (Derived_Type);
-- Restore the fields saved prior to the New_Copy_Tree call
-- and compute the stored constraint.
Set_Etype (Derived_Type, Save_Etype);
Link_Entities (Derived_Type, Save_Next_Entity);
if Has_Discriminants (Derived_Type) then
Set_Discriminant_Constraint
(Derived_Type, Save_Discr_Constr);
Set_Stored_Constraint
(Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
Replace_Discriminants (Derived_Type, New_Decl);
end if;
-- Insert the new derived type declaration
Rewrite (N, New_Decl);
-- STEP 5b: Complete the processing for record extensions in generics
-- There is no completion for record extensions declared in the
-- parameter part of a generic, so we need to complete processing for
-- these generic record extensions here. The Record_Type_Definition call
-- will change the Ekind of the components from E_Void to E_Component.
elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
Record_Type_Definition (Empty, Derived_Type);
-- STEP 5c: Process the record extension for non private tagged types
elsif not Private_Extension then
Expand_Record_Extension (Derived_Type, Type_Def);
-- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
-- implemented interfaces if we are in expansion mode
if Expander_Active
and then Has_Interfaces (Derived_Type)
then
Add_Interface_Tag_Components (N, Derived_Type);
end if;
-- Analyze the record extension
Record_Type_Definition
(Record_Extension_Part (Type_Def), Derived_Type);
end if;
End_Scope;
-- Nothing else to do if there is an error in the derivation.
-- An unusual case: the full view may be derived from a type in an
-- instance, when the partial view was used illegally as an actual
-- in that instance, leading to a circular definition.
if Etype (Derived_Type) = Any_Type
or else Etype (Parent_Type) = Derived_Type
then
return;
end if;
-- Set delayed freeze and then derive subprograms, we need to do
-- this in this order so that derived subprograms inherit the
-- derived freeze if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
-- If we have a private extension which defines a constrained derived
-- type mark as constrained here after we have derived subprograms. See
-- comment on point 9. just above the body of Build_Derived_Record_Type.
if Private_Extension and then Inherit_Discrims then
if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
Set_Is_Constrained (Derived_Type, True);
Set_Discriminant_Constraint (Derived_Type, Discs);
elsif Is_Constrained (Parent_Type) then
Set_Is_Constrained
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
-- Update the class-wide type, which shares the now-completed entity
-- list with its specific type. In case of underlying record views,
-- we do not generate the corresponding class wide entity.
if Is_Tagged
and then not Is_Underlying_Record_View (Derived_Type)
then
Set_First_Entity
(Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
Set_Last_Entity
(Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
end if;
Check_Function_Writable_Actuals (N);
end Build_Derived_Record_Type;
------------------------
-- Build_Derived_Type --
------------------------
procedure Build_Derived_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
begin
-- Set common attributes
if Ekind (Derived_Type) in Incomplete_Or_Private_Kind
and then Ekind (Parent_Base) in Modular_Integer_Kind | Array_Kind
then
Reinit_Field_To_Zero (Derived_Type, F_Stored_Constraint);
end if;
Set_Scope (Derived_Type, Current_Scope);
Set_Etype (Derived_Type, Parent_Base);
Mutate_Ekind (Derived_Type, Ekind (Parent_Base));
Propagate_Concurrent_Flags (Derived_Type, Parent_Base);
Set_Size_Info (Derived_Type, Parent_Type);
Copy_RM_Size (To => Derived_Type, From => Parent_Type);
Set_Is_Controlled_Active
(Derived_Type, Is_Controlled_Active (Parent_Type));
Set_Disable_Controlled (Derived_Type, Disable_Controlled (Parent_Type));
Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
Set_Is_Volatile (Derived_Type, Is_Volatile (Parent_Type));
if Is_Tagged_Type (Derived_Type) then
Set_No_Tagged_Streams_Pragma
(Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
end if;
-- If the parent has primitive routines and may have not-seen-yet aspect
-- specifications (e.g., a Pack pragma), then set the derived type link
-- in order to later diagnose "early derivation" issues. If in different
-- compilation units, then "early derivation" cannot be an issue (and we
-- don't like interunit references that go in the opposite direction of
-- semantic dependencies).
if Has_Primitive_Operations (Parent_Type)
and then Enclosing_Comp_Unit_Node (Parent_Type) =
Enclosing_Comp_Unit_Node (Derived_Type)
then
Set_Derived_Type_Link (Parent_Base, Derived_Type);
end if;
-- If the parent type is a private subtype, the convention on the base
-- type may be set in the private part, and not propagated to the
-- subtype until later, so we obtain the convention from the base type.
Set_Convention (Derived_Type, Convention (Parent_Base));
if Is_Tagged_Type (Derived_Type)
and then Present (Class_Wide_Type (Derived_Type))
then
Set_Convention (Class_Wide_Type (Derived_Type),
Convention (Class_Wide_Type (Parent_Base)));
end if;
-- Set SSO default for record or array type
if (Is_Array_Type (Derived_Type) or else Is_Record_Type (Derived_Type))
and then Is_Base_Type (Derived_Type)
then
Set_Default_SSO (Derived_Type);
end if;
-- A derived type inherits the Default_Initial_Condition pragma coming
-- from any parent type within the derivation chain.
if Has_DIC (Parent_Type) then
Set_Has_Inherited_DIC (Derived_Type);
end if;
-- A derived type inherits any class-wide invariants coming from a
-- parent type or an interface. Note that the invariant procedure of
-- the parent type should not be inherited because the derived type may
-- define invariants of its own.
if not Is_Interface (Derived_Type) then
if Has_Inherited_Invariants (Parent_Type)
or else Has_Inheritable_Invariants (Parent_Type)
then
Set_Has_Inherited_Invariants (Derived_Type);
elsif Is_Concurrent_Type (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
declare
Iface : Entity_Id;
Ifaces : Elist_Id;
Iface_Elmt : Elmt_Id;
begin
Collect_Interfaces
(T => Derived_Type,
Ifaces_List => Ifaces,
Exclude_Parents => True);
if Present (Ifaces) then
Iface_Elmt := First_Elmt (Ifaces);
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
if Has_Inheritable_Invariants (Iface) then
Set_Has_Inherited_Invariants (Derived_Type);
exit;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
end;
end if;
end if;
-- We similarly inherit predicates. Note that for scalar derived types
-- the predicate is inherited from the first subtype, and not from its
-- (anonymous) base type.
if Has_Predicates (Parent_Type)
or else Has_Predicates (First_Subtype (Parent_Type))
then
Set_Has_Predicates (Derived_Type);
end if;
-- The derived type inherits representation clauses from the parent
-- type, and from any interfaces.
Inherit_Rep_Item_Chain (Derived_Type, Parent_Type);
declare
Iface : Node_Id := First (Abstract_Interface_List (Derived_Type));
begin
while Present (Iface) loop
Inherit_Rep_Item_Chain (Derived_Type, Entity (Iface));
Next (Iface);
end loop;
end;
-- If the parent type has delayed rep aspects, then mark the derived
-- type as possibly inheriting a delayed rep aspect.
if Has_Delayed_Rep_Aspects (Parent_Type) then
Set_May_Inherit_Delayed_Rep_Aspects (Derived_Type);
end if;
-- A derived type becomes Ghost when its parent type is also Ghost
-- (SPARK RM 6.9(9)). Note that the Ghost-related attributes are not
-- directly inherited because the Ghost policy in effect may differ.
if Is_Ghost_Entity (Parent_Type) then
Set_Is_Ghost_Entity (Derived_Type);
end if;
-- Type dependent processing
case Ekind (Parent_Type) is
when Numeric_Kind =>
Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
when Array_Kind =>
Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
when Class_Wide_Kind
| E_Record_Subtype
| E_Record_Type
=>
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
return;
when Enumeration_Kind =>
Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
when Access_Kind =>
Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
when Incomplete_Or_Private_Kind =>
Build_Derived_Private_Type
(N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
-- For discriminated types, the derivation includes deriving
-- primitive operations. For others it is done below.
if Is_Tagged_Type (Parent_Type)
or else Has_Discriminants (Parent_Type)
or else (Present (Full_View (Parent_Type))
and then Has_Discriminants (Full_View (Parent_Type)))
then
return;
end if;
when Concurrent_Kind =>
Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
when others =>
raise Program_Error;
end case;
-- Nothing more to do if some error occurred
if Etype (Derived_Type) = Any_Type then
return;
end if;
-- If not already set, initialize the derived type's list of primitive
-- operations to an empty element list.
if not Present (Direct_Primitive_Operations (Derived_Type)) then
Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
-- If Etype of the derived type is the base type (as opposed to
-- a parent type) and doesn't have an associated list of primitive
-- operations, then set the base type's primitive list to the
-- derived type's list. The lists need to be shared in common
-- between the two.
if Etype (Derived_Type) = Base_Type (Derived_Type)
and then
not Present (Direct_Primitive_Operations (Etype (Derived_Type)))
then
Set_Direct_Primitive_Operations
(Etype (Derived_Type),
Direct_Primitive_Operations (Derived_Type));
end if;
end if;
-- Set delayed freeze and then derive subprograms, we need to do this
-- in this order so that derived subprograms inherit the derived freeze
-- if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
Set_Has_Primitive_Operations
(Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
end Build_Derived_Type;
-----------------------
-- Build_Discriminal --
-----------------------
procedure Build_Discriminal (Discrim : Entity_Id) is
D_Minal : Entity_Id;
CR_Disc : Entity_Id;
begin
-- A discriminal has the same name as the discriminant
D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
Mutate_Ekind (D_Minal, E_In_Parameter);
Set_Mechanism (D_Minal, Default_Mechanism);
Set_Etype (D_Minal, Etype (Discrim));
Set_Scope (D_Minal, Current_Scope);
Set_Parent (D_Minal, Parent (Discrim));
Set_Discriminal (Discrim, D_Minal);
Set_Discriminal_Link (D_Minal, Discrim);
-- For task types, build at once the discriminants of the corresponding
-- record, which are needed if discriminants are used in entry defaults
-- and in family bounds.
if Is_Concurrent_Type (Current_Scope)
or else
Is_Limited_Type (Current_Scope)
then
CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
Mutate_Ekind (CR_Disc, E_In_Parameter);
Set_Mechanism (CR_Disc, Default_Mechanism);
Set_Etype (CR_Disc, Etype (Discrim));
Set_Scope (CR_Disc, Current_Scope);
Set_Discriminal_Link (CR_Disc, Discrim);
Set_CR_Discriminant (Discrim, CR_Disc);
end if;
end Build_Discriminal;
------------------------------------
-- Build_Discriminant_Constraints --
------------------------------------
function Build_Discriminant_Constraints
(T : Entity_Id;
Def : Node_Id;
Derived_Def : Boolean := False) return Elist_Id
is
C : constant Node_Id := Constraint (Def);
Nb_Discr : constant Nat := Number_Discriminants (T);
Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
-- Saves the expression corresponding to a given discriminant in T
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
-- Return the Position number within array Discr_Expr of a discriminant
-- D within the discriminant list of the discriminated type T.
procedure Process_Discriminant_Expression
(Expr : Node_Id;
D : Entity_Id);
-- If this is a discriminant constraint on a partial view, do not
-- generate an overflow check on the discriminant expression. The check
-- will be generated when constraining the full view. Otherwise the
-- backend creates duplicate symbols for the temporaries corresponding
-- to the expressions to be checked, causing spurious assembler errors.
------------------
-- Pos_Of_Discr --
------------------
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
Disc : Entity_Id;
begin
Disc := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Disc = D then
return J;
end if;
Next_Discriminant (Disc);
end loop;
-- Note: Since this function is called on discriminants that are
-- known to belong to the discriminated type, falling through the
-- loop with no match signals an internal compiler error.
raise Program_Error;
end Pos_Of_Discr;
-------------------------------------
-- Process_Discriminant_Expression --
-------------------------------------
procedure Process_Discriminant_Expression
(Expr : Node_Id;
D : Entity_Id)
is
BDT : constant Entity_Id := Base_Type (Etype (D));
begin
-- If this is a discriminant constraint on a partial view, do
-- not generate an overflow on the discriminant expression. The
-- check will be generated when constraining the full view.
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check);
else
Analyze_And_Resolve (Expr, BDT);
end if;
end Process_Discriminant_Expression;
-- Declarations local to Build_Discriminant_Constraints
Discr : Entity_Id;
E : Entity_Id;
Elist : constant Elist_Id := New_Elmt_List;
Constr : Node_Id;
Expr : Node_Id;
Id : Node_Id;
Position : Nat;
Found : Boolean;
Discrim_Present : Boolean := False;
-- Start of processing for Build_Discriminant_Constraints
begin
-- The following loop will process positional associations only.
-- For a positional association, the (single) discriminant is
-- implicitly specified by position, in textual order (RM 3.7.2).
Discr := First_Discriminant (T);
Constr := First (Constraints (C));
for D in Discr_Expr'Range loop
exit when Nkind (Constr) = N_Discriminant_Association;
if No (Constr) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
elsif Nkind (Constr) = N_Range
or else (Nkind (Constr) = N_Attribute_Reference
and then Attribute_Name (Constr) = Name_Range)
then
Error_Msg_N
("a range is not a valid discriminant constraint", Constr);
Discr_Expr (D) := Error;
elsif Nkind (Constr) = N_Subtype_Indication then
Error_Msg_N
("a subtype indication is not a valid discriminant constraint",
Constr);
Discr_Expr (D) := Error;
else
Process_Discriminant_Expression (Constr, Discr);
Discr_Expr (D) := Constr;
end if;
Next_Discriminant (Discr);
Next (Constr);
end loop;
if No (Discr) and then Present (Constr) then
Error_Msg_N ("too many discriminants given in constraint", Constr);
return New_Elmt_List;
end if;
-- Named associations can be given in any order, but if both positional
-- and named associations are used in the same discriminant constraint,
-- then positional associations must occur first, at their normal
-- position. Hence once a named association is used, the rest of the
-- discriminant constraint must use only named associations.
while Present (Constr) loop
-- Positional association forbidden after a named association
if Nkind (Constr) /= N_Discriminant_Association then
Error_Msg_N ("positional association follows named one", Constr);
return New_Elmt_List;
-- Otherwise it is a named association
else
-- E records the type of the discriminants in the named
-- association. All the discriminants specified in the same name
-- association must have the same type.
E := Empty;
-- Search the list of discriminants in T to see if the simple name
-- given in the constraint matches any of them.
Id := First (Selector_Names (Constr));
while Present (Id) loop
Found := False;
-- If Original_Discriminant is present, we are processing a
-- generic instantiation and this is an instance node. We need
-- to find the name of the corresponding discriminant in the
-- actual record type T and not the name of the discriminant in
-- the generic formal. Example:
-- generic
-- type G (D : int) is private;
-- package P is
-- subtype W is G (D => 1);
-- end package;
-- type Rec (X : int) is record ... end record;
-- package Q is new P (G => Rec);
-- At the point of the instantiation, formal type G is Rec
-- and therefore when reanalyzing "subtype W is G (D => 1);"
-- which really looks like "subtype W is Rec (D => 1);" at
-- the point of instantiation, we want to find the discriminant
-- that corresponds to D in Rec, i.e. X.
if Present (Original_Discriminant (Id))
and then In_Instance
then
Discr := Find_Corresponding_Discriminant (Id, T);
Found := True;
else
Discr := First_Discriminant (T);
while Present (Discr) loop
if Chars (Discr) = Chars (Id) then
Found := True;
exit;
end if;
Next_Discriminant (Discr);
end loop;
if not Found then
Error_Msg_N ("& does not match any discriminant", Id);
return New_Elmt_List;
-- If the parent type is a generic formal, preserve the
-- name of the discriminant for subsequent instances.
-- see comment at the beginning of this if statement.
elsif Is_Generic_Type (Root_Type (T)) then
Set_Original_Discriminant (Id, Discr);
end if;
end if;
Position := Pos_Of_Discr (T, Discr);
if Present (Discr_Expr (Position)) then
Error_Msg_N ("duplicate constraint for discriminant&", Id);
else
-- Each discriminant specified in the same named association
-- must be associated with a separate copy of the
-- corresponding expression.
if Present (Next (Id)) then
Expr := New_Copy_Tree (Expression (Constr));
Set_Parent (Expr, Parent (Expression (Constr)));
else
Expr := Expression (Constr);
end if;
Discr_Expr (Position) := Expr;
Process_Discriminant_Expression (Expr, Discr);
end if;
-- A discriminant association with more than one discriminant
-- name is only allowed if the named discriminants are all of
-- the same type (RM 3.7.1(8)).
if E = Empty then
E := Base_Type (Etype (Discr));
elsif Base_Type (Etype (Discr)) /= E then
Error_Msg_N
("all discriminants in an association " &
"must have the same type", Id);
end if;
Next (Id);
end loop;
end if;
Next (Constr);
end loop;
-- A discriminant constraint must provide exactly one value for each
-- discriminant of the type (RM 3.7.1(8)).
for J in Discr_Expr'Range loop
if No (Discr_Expr (J)) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
end if;
end loop;
-- Determine if there are discriminant expressions in the constraint
for J in Discr_Expr'Range loop
if Denotes_Discriminant
(Discr_Expr (J), Check_Concurrent => True)
then
Discrim_Present := True;
exit;
end if;
end loop;
-- Build an element list consisting of the expressions given in the
-- discriminant constraint and apply the appropriate checks. The list
-- is constructed after resolving any named discriminant associations
-- and therefore the expressions appear in the textual order of the
-- discriminants.
Discr := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Discr_Expr (J) /= Error then
Append_Elmt (Discr_Expr (J), Elist);
-- If any of the discriminant constraints is given by a
-- discriminant and we are in a derived type declaration we
-- have a discriminant renaming. Establish link between new
-- and old discriminant. The new discriminant has an implicit
-- dereference if the old one does.
if Denotes_Discriminant (Discr_Expr (J)) then
if Derived_Def then
declare
New_Discr : constant Entity_Id := Entity (Discr_Expr (J));
begin
Set_Corresponding_Discriminant (New_Discr, Discr);
Set_Has_Implicit_Dereference (New_Discr,
Has_Implicit_Dereference (Discr));
end;
end if;
-- Force the evaluation of non-discriminant expressions.
-- If we have found a discriminant in the constraint 3.4(26)
-- and 3.8(18) demand that no range checks are performed are
-- after evaluation. If the constraint is for a component
-- definition that has a per-object constraint, expressions are
-- evaluated but not checked either. In all other cases perform
-- a range check.
else
if Discrim_Present then
null;
elsif Parent_Kind (Parent (Def)) = N_Component_Declaration
and then Has_Per_Object_Constraint
(Defining_Identifier (Parent (Parent (Def))))
then
null;
elsif Is_Access_Type (Etype (Discr)) then
Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
else
Apply_Range_Check (Discr_Expr (J), Etype (Discr));
end if;
-- If the value of the discriminant may be visible in
-- another unit or child unit, create an external name
-- for it. We use the name of the object or component
-- that carries the discriminated subtype. The code
-- below may generate external symbols for the discriminant
-- expression when not strictly needed, which is harmless.
if Expander_Active
and then Comes_From_Source (Def)
and then not Is_Subprogram (Current_Scope)
then
declare
Id : Entity_Id := Empty;
begin
if Nkind (Parent (Def)) = N_Object_Declaration then
Id := Defining_Identifier (Parent (Def));
elsif Nkind (Parent (Def)) = N_Component_Definition
and then
Nkind (Parent (Parent (Def)))
= N_Component_Declaration
then
Id := Defining_Identifier (Parent (Parent (Def)));
end if;
if Present (Id) then
Force_Evaluation (
Discr_Expr (J),
Related_Id => Id,
Discr_Number => J);
else
Force_Evaluation (Discr_Expr (J));
end if;
end;
else
Force_Evaluation (Discr_Expr (J));
end if;
end if;
-- Check that the designated type of an access discriminant's
-- expression is not a class-wide type unless the discriminant's
-- designated type is also class-wide.
if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
and then not Is_Class_Wide_Type
(Designated_Type (Etype (Discr)))
and then Etype (Discr_Expr (J)) /= Any_Type
and then Is_Class_Wide_Type
(Designated_Type (Etype (Discr_Expr (J))))
then
Wrong_Type (Discr_Expr (J), Etype (Discr));
elsif Is_Access_Type (Etype (Discr))
and then not Is_Access_Constant (Etype (Discr))
and then Is_Access_Type (Etype (Discr_Expr (J)))
and then Is_Access_Constant (Etype (Discr_Expr (J)))
then
Error_Msg_NE
("constraint for discriminant& must be access to variable",
Def, Discr);
end if;
end if;
Next_Discriminant (Discr);
end loop;
return Elist;
end Build_Discriminant_Constraints;
---------------------------------
-- Build_Discriminated_Subtype --
---------------------------------
procedure Build_Discriminated_Subtype
(T : Entity_Id;
Def_Id : Entity_Id;
Elist : Elist_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
Has_Discrs : constant Boolean := Has_Discriminants (T);
Constrained : constant Boolean :=
(Has_Discrs
and then not Is_Empty_Elmt_List (Elist)
and then not Is_Class_Wide_Type (T))
or else Is_Constrained (T);
begin
if Ekind (T) = E_Record_Type then
Mutate_Ekind (Def_Id, E_Record_Subtype);
-- Inherit preelaboration flag from base, for types for which it
-- may have been set: records, private types, protected types.
Set_Known_To_Have_Preelab_Init
(Def_Id, Known_To_Have_Preelab_Init (T));
elsif Ekind (T) = E_Task_Type then
Mutate_Ekind (Def_Id, E_Task_Subtype);
elsif Ekind (T) = E_Protected_Type then
Mutate_Ekind (Def_Id, E_Protected_Subtype);
Set_Known_To_Have_Preelab_Init
(Def_Id, Known_To_Have_Preelab_Init (T));
elsif Is_Private_Type (T) then
Mutate_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
Set_Known_To_Have_Preelab_Init
(Def_Id, Known_To_Have_Preelab_Init (T));
-- Private subtypes may have private dependents
Set_Private_Dependents (Def_Id, New_Elmt_List);
elsif Is_Class_Wide_Type (T) then
Mutate_Ekind (Def_Id, E_Class_Wide_Subtype);
else
-- Incomplete type. Attach subtype to list of dependents, to be
-- completed with full view of parent type, unless is it the
-- designated subtype of a record component within an init_proc.
-- This last case arises for a component of an access type whose
-- designated type is incomplete (e.g. a Taft Amendment type).
-- The designated subtype is within an inner scope, and needs no
-- elaboration, because only the access type is needed in the
-- initialization procedure.
if Ekind (T) = E_Incomplete_Type then
Mutate_Ekind (Def_Id, E_Incomplete_Subtype);
else
Mutate_Ekind (Def_Id, Ekind (T));
end if;
if For_Access and then Within_Init_Proc then
null;
else
Append_Elmt (Def_Id, Private_Dependents (T));
end if;
end if;
Set_Etype (Def_Id, T);
Reinit_Size_Align (Def_Id);
Set_Has_Discriminants (Def_Id, Has_Discrs);
Set_Is_Constrained (Def_Id, Constrained);
Set_First_Entity (Def_Id, First_Entity (T));
Set_Last_Entity (Def_Id, Last_Entity (T));
Set_Has_Implicit_Dereference
(Def_Id, Has_Implicit_Dereference (T));
Set_Has_Pragma_Unreferenced_Objects
(Def_Id, Has_Pragma_Unreferenced_Objects (T));
-- If the subtype is the completion of a private declaration, there may
-- have been representation clauses for the partial view, and they must
-- be preserved. Build_Derived_Type chains the inherited clauses with
-- the ones appearing on the extension. If this comes from a subtype
-- declaration, all clauses are inherited.
if No (First_Rep_Item (Def_Id)) then
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
end if;
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Def_Id);
Set_No_Tagged_Streams_Pragma (Def_Id, No_Tagged_Streams_Pragma (T));
Make_Class_Wide_Type (Def_Id);
end if;
Set_Stored_Constraint (Def_Id, No_Elist);
if Has_Discrs then
Set_Discriminant_Constraint (Def_Id, Elist);
Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
end if;
if Is_Tagged_Type (T) then
-- Ada 2005 (AI-251): In case of concurrent types we inherit the
-- concurrent record type (which has the list of primitive
-- operations).
if Ada_Version >= Ada_2005
and then Is_Concurrent_Type (T)
then
Set_Corresponding_Record_Type (Def_Id,
Corresponding_Record_Type (T));
else
Set_Direct_Primitive_Operations (Def_Id,
Direct_Primitive_Operations (T));
end if;
Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T));
end if;
-- Subtypes introduced by component declarations do not need to be
-- marked as delayed, and do not get freeze nodes, because the semantics
-- verifies that the parents of the subtypes are frozen before the
-- enclosing record is frozen.
if not Is_Type (Scope (Def_Id)) then
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Conditional_Delay (Def_Id, Full_View (T));
else
Conditional_Delay (Def_Id, T);
end if;
end if;
if Is_Record_Type (T) then
Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
if Has_Discrs
and then not Is_Empty_Elmt_List (Elist)
and then not For_Access
then
Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
elsif not Is_Private_Type (T) then
Set_Cloned_Subtype (Def_Id, T);
end if;
end if;
end Build_Discriminated_Subtype;
---------------------------
-- Build_Itype_Reference --
---------------------------
procedure Build_Itype_Reference
(Ityp : Entity_Id;
Nod : Node_Id)
is
IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
begin
-- Itype references are only created for use by the back-end
if Inside_A_Generic then
return;
else
Set_Itype (IR, Ityp);
-- If Nod is a library unit entity, then Insert_After won't work,
-- because Nod is not a member of any list. Therefore, we use
-- Add_Global_Declaration in this case. This can happen if we have a
-- build-in-place library function, child unit or not.
if (Nkind (Nod) in N_Entity and then Is_Compilation_Unit (Nod))
or else (Nkind (Nod) in
N_Defining_Program_Unit_Name | N_Subprogram_Declaration
and then Is_Compilation_Unit (Defining_Entity (Nod)))
then
Add_Global_Declaration (IR);
else
Insert_After (Nod, IR);
end if;
end if;
end Build_Itype_Reference;
------------------------
-- Build_Scalar_Bound --
------------------------
function Build_Scalar_Bound
(Bound : Node_Id;
Par_T : Entity_Id;
Der_T : Entity_Id) return Node_Id
is
New_Bound : Entity_Id;
begin
-- Note: not clear why this is needed, how can the original bound
-- be unanalyzed at this point? and if it is, what business do we
-- have messing around with it? and why is the base type of the
-- parent type the right type for the resolution. It probably is
-- not. It is OK for the new bound we are creating, but not for
-- the old one??? Still if it never happens, no problem.
Analyze_And_Resolve (Bound, Base_Type (Par_T));
if Nkind (Bound) in N_Integer_Literal | N_Real_Literal then
New_Bound := New_Copy (Bound);
Set_Etype (New_Bound, Der_T);
Set_Analyzed (New_Bound);
elsif Is_Entity_Name (Bound) then
New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
-- The following is almost certainly wrong. What business do we have
-- relocating a node (Bound) that is presumably still attached to
-- the tree elsewhere???
else
New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
end if;
Set_Etype (New_Bound, Der_T);
return New_Bound;
end Build_Scalar_Bound;
-------------------------------
-- Check_Abstract_Overriding --
-------------------------------
procedure Check_Abstract_Overriding (T : Entity_Id) is
Alias_Subp : Entity_Id;
Elmt : Elmt_Id;
Op_List : Elist_Id;
Subp : Entity_Id;
Type_Def : Node_Id;
procedure Check_Pragma_Implemented (Subp : Entity_Id);
-- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
-- which has pragma Implemented already set. Check whether Subp's entity
-- kind conforms to the implementation kind of the overridden routine.
procedure Check_Pragma_Implemented
(Subp : Entity_Id;
Iface_Subp : Entity_Id);
-- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
-- Iface_Subp and both entities have pragma Implemented already set on
-- them. Check whether the two implementation kinds are conforming.
procedure Inherit_Pragma_Implemented
(Subp : Entity_Id;
Iface_Subp : Entity_Id);
-- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
-- subprogram Iface_Subp which has been marked by pragma Implemented.
-- Propagate the implementation kind of Iface_Subp to Subp.
------------------------------
-- Check_Pragma_Implemented --
------------------------------
procedure Check_Pragma_Implemented (Subp : Entity_Id) is
Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
Subp_Alias : constant Entity_Id := Alias (Subp);
Contr_Typ : Entity_Id;
Impl_Subp : Entity_Id;
begin
-- Subp must have an alias since it is a hidden entity used to link
-- an interface subprogram to its overriding counterpart.
pragma Assert (Present (Subp_Alias));
-- Handle aliases to synchronized wrappers
Impl_Subp := Subp_Alias;
if Is_Primitive_Wrapper (Impl_Subp) then
Impl_Subp := Wrapped_Entity (Impl_Subp);
end if;
-- Extract the type of the controlling formal
Contr_Typ := Etype (First_Formal (Subp_Alias));
if Is_Concurrent_Record_Type (Contr_Typ) then
Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
end if;
-- An interface subprogram whose implementation kind is By_Entry must
-- be implemented by an entry.
if Impl_Kind = Name_By_Entry
and then Ekind (Impl_Subp) /= E_Entry
then
Error_Msg_Node_2 := Iface_Alias;
Error_Msg_NE
("type & must implement abstract subprogram & with an entry",
Subp_Alias, Contr_Typ);
elsif Impl_Kind = Name_By_Protected_Procedure then
-- An interface subprogram whose implementation kind is By_
-- Protected_Procedure cannot be implemented by a primitive
-- procedure of a task type.
if Ekind (Contr_Typ) /= E_Protected_Type then
Error_Msg_Node_2 := Contr_Typ;
Error_Msg_NE
("interface subprogram & cannot be implemented by a "
& "primitive procedure of task type &",
Subp_Alias, Iface_Alias);
-- An interface subprogram whose implementation kind is By_
-- Protected_Procedure must be implemented by a procedure.
elsif Ekind (Impl_Subp) /= E_Procedure then
Error_Msg_Node_2 := Iface_Alias;
Error_Msg_NE
("type & must implement abstract subprogram & with a "
& "procedure", Subp_Alias, Contr_Typ);
elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
and then Implementation_Kind (Impl_Subp) /= Impl_Kind
then
Error_Msg_Name_1 := Impl_Kind;
Error_Msg_N
("overriding operation& must have synchronization%",
Subp_Alias);
end if;
-- If primitive has Optional synchronization, overriding operation
-- must match if it has an explicit synchronization.
elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
and then Implementation_Kind (Impl_Subp) /= Impl_Kind
then
Error_Msg_Name_1 := Impl_Kind;
Error_Msg_N
("overriding operation& must have synchronization%", Subp_Alias);
end if;
end Check_Pragma_Implemented;
------------------------------
-- Check_Pragma_Implemented --
------------------------------
procedure Check_Pragma_Implemented
(Subp : Entity_Id;
Iface_Subp : Entity_Id)
is
Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
begin
-- Ada 2012 (AI05-0030): The implementation kinds of an overridden
-- and overriding subprogram are different. In general this is an
-- error except when the implementation kind of the overridden
-- subprograms is By_Any or Optional.
if Iface_Kind /= Subp_Kind
and then Iface_Kind /= Name_By_Any
and then Iface_Kind /= Name_Optional
then
if Iface_Kind = Name_By_Entry then
Error_Msg_N
("incompatible implementation kind, overridden subprogram " &
"is marked By_Entry", Subp);
else
Error_Msg_N
("incompatible implementation kind, overridden subprogram " &
"is marked By_Protected_Procedure", Subp);
end if;
end if;
end Check_Pragma_Implemented;
--------------------------------
-- Inherit_Pragma_Implemented --
--------------------------------
procedure Inherit_Pragma_Implemented
(Subp : Entity_Id;
Iface_Subp : Entity_Id)
is
Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
Loc : constant Source_Ptr := Sloc (Subp);
Impl_Prag : Node_Id;
begin
-- Since the implementation kind is stored as a representation item
-- rather than a flag, create a pragma node.
Impl_Prag :=
Make_Pragma (Loc,
Chars => Name_Implemented,
Pragma_Argument_Associations => New_List (
Make_Pragma_Argument_Association (Loc,
Expression => New_Occurrence_Of (Subp, Loc)),
Make_Pragma_Argument_Association (Loc,
Expression => Make_Identifier (Loc, Iface_Kind))));
-- The pragma doesn't need to be analyzed because it is internally
-- built. It is safe to directly register it as a rep item since we
-- are only interested in the characters of the implementation kind.
Record_Rep_Item (Subp, Impl_Prag);
end Inherit_Pragma_Implemented;
-- Start of processing for Check_Abstract_Overriding
begin
Op_List := Primitive_Operations (T);
-- Loop to check primitive operations
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
Alias_Subp := Alias (Subp);
-- If the parent type is untagged, then no overriding error checks
-- are needed (such as in the case of an implicit full type for
-- a derived type whose parent is an untagged private type with
-- a tagged full type).
if not Is_Tagged_Type (Etype (T)) then
null;
-- Inherited subprograms are identified by the fact that they do not
-- come from source, and the associated source location is the
-- location of the first subtype of the derived type.
-- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
-- subprograms that "require overriding".
-- Special exception, do not complain about failure to override the
-- stream routines _Input and _Output, as well as the primitive
-- operations used in dispatching selects since we always provide
-- automatic overridings for these subprograms.
-- The partial view of T may have been a private extension, for
-- which inherited functions dispatching on result are abstract.
-- If the full view is a null extension, there is no need for
-- overriding in Ada 2005, but wrappers need to be built for them
-- (see exp_ch3, Build_Controlling_Function_Wrappers).
elsif Is_Null_Extension (T)
and then Has_Controlling_Result (Subp)
and then Ada_Version >= Ada_2005
and then Present (Alias_Subp)
and then not Comes_From_Source (Subp)
and then not Is_Abstract_Subprogram (Alias_Subp)
and then not Is_Access_Type (Etype (Subp))
then
null;
-- Ada 2005 (AI-251): Internal entities of interfaces need no
-- processing because this check is done with the aliased
-- entity
elsif Present (Interface_Alias (Subp)) then
null;
-- AI12-0042: Test for rule in 7.3.2(6.1/4), that requires overriding
-- of a visible private primitive inherited from an ancestor with
-- the aspect Type_Invariant'Class, unless the inherited primitive
-- is abstract.
elsif not Is_Abstract_Subprogram (Subp)
and then not Comes_From_Source (Subp) -- An inherited subprogram
and then Requires_Overriding (Subp)
and then Present (Alias_Subp)
and then Has_Invariants (Etype (T))
and then Present (Get_Pragma (Etype (T), Pragma_Invariant))
and then Class_Present (Get_Pragma (Etype (T), Pragma_Invariant))
and then Is_Private_Primitive (Alias_Subp)
then
Error_Msg_NE
("inherited private primitive & must be overridden", T, Subp);
Error_Msg_N
("\because ancestor type has 'Type_'Invariant''Class " &
"(RM 7.3.2(6.1))", T);
elsif (Is_Abstract_Subprogram (Subp)
or else Requires_Overriding (Subp)
or else
(Has_Controlling_Result (Subp)
and then Present (Alias_Subp)
and then not Comes_From_Source (Subp)
and then Sloc (Subp) = Sloc (First_Subtype (T))))
and then not Is_TSS (Subp, TSS_Stream_Input)
and then not Is_TSS (Subp, TSS_Stream_Output)
and then not Is_Abstract_Type (T)
and then not Is_Predefined_Interface_Primitive (Subp)
-- Ada 2005 (AI-251): Do not consider hidden entities associated
-- with abstract interface types because the check will be done
-- with the aliased entity (otherwise we generate a duplicated
-- error message).
and then No (Interface_Alias (Subp))
then
if Present (Alias_Subp) then
-- Only perform the check for a derived subprogram when the
-- type has an explicit record extension. This avoids incorrect
-- flagging of abstract subprograms for the case of a type
-- without an extension that is derived from a formal type
-- with a tagged actual (can occur within a private part).
-- Ada 2005 (AI-391): In the case of an inherited function with
-- a controlling result of the type, the rule does not apply if
-- the type is a null extension (unless the parent function
-- itself is abstract, in which case the function must still be
-- be overridden). The expander will generate an overriding
-- wrapper function calling the parent subprogram (see
-- Exp_Ch3.Make_Controlling_Wrapper_Functions).
Type_Def := Type_Definition (Parent (T));
if Nkind (Type_Def) = N_Derived_Type_Definition
and then Present (Record_Extension_Part (Type_Def))
and then
(Ada_Version < Ada_2005
or else not Is_Null_Extension (T)
or else Ekind (Subp) = E_Procedure
or else not Has_Controlling_Result (Subp)
or else Is_Abstract_Subprogram (Alias_Subp)
or else Requires_Overriding (Subp)
or else Is_Access_Type (Etype (Subp)))
then
-- Avoid reporting error in case of abstract predefined
-- primitive inherited from interface type because the
-- body of internally generated predefined primitives
-- of tagged types are generated later by Freeze_Type
if Is_Interface (Root_Type (T))
and then Is_Abstract_Subprogram (Subp)
and then Is_Predefined_Dispatching_Operation (Subp)
and then not Comes_From_Source (Ultimate_Alias (Subp))
then
null;
-- A null extension is not obliged to override an inherited
-- procedure subject to pragma Extensions_Visible with value
-- False and at least one controlling OUT parameter
-- (SPARK RM 6.1.7(6)).
elsif Is_Null_Extension (T)
and then Is_EVF_Procedure (Subp)
then
null;
-- Subprogram renamings cannot be overridden
elsif Comes_From_Source (Subp)
and then Present (Alias (Subp))
then
null;
-- Skip reporting the error on Ada 2022 only subprograms
-- that require overriding if we are not in Ada 2022 mode.
elsif Ada_Version < Ada_2022
and then Requires_Overriding (Subp)
and then Is_Ada_2022_Only (Ultimate_Alias (Subp))
then
null;
else
Error_Msg_NE
("type must be declared abstract or & overridden",
T, Subp);
-- Traverse the whole chain of aliased subprograms to
-- complete the error notification. This is especially
-- useful for traceability of the chain of entities when
-- the subprogram corresponds with an interface
-- subprogram (which may be defined in another package).
if Present (Alias_Subp) then
declare
E : Entity_Id;
begin
E := Subp;
while Present (Alias (E)) loop
-- Avoid reporting redundant errors on entities
-- inherited from interfaces
if Sloc (E) /= Sloc (T) then
Error_Msg_Sloc := Sloc (E);
Error_Msg_NE
("\& has been inherited #", T, Subp);
end if;
E := Alias (E);
end loop;
Error_Msg_Sloc := Sloc (E);
-- AI05-0068: report if there is an overriding
-- non-abstract subprogram that is invisible.
if Is_Hidden (E)
and then not Is_Abstract_Subprogram (E)
then
Error_Msg_NE
("\& subprogram# is not visible",
T, Subp);
-- Clarify the case where a non-null extension must
-- override inherited procedure subject to pragma
-- Extensions_Visible with value False and at least
-- one controlling OUT param.
elsif Is_EVF_Procedure (E) then
Error_Msg_NE
("\& # is subject to Extensions_Visible False",
T, Subp);
else
Error_Msg_NE
("\& has been inherited from subprogram #",
T, Subp);
end if;
end;
end if;
end if;
-- Ada 2005 (AI-345): Protected or task type implementing
-- abstract interfaces.
elsif Is_Concurrent_Record_Type (T)
and then Present (Interfaces (T))
then
-- There is no need to check here RM 9.4(11.9/3) since we
-- are processing the corresponding record type and the
-- mode of the overriding subprograms was verified by
-- Check_Conformance when the corresponding concurrent
-- type declaration was analyzed.
Error_Msg_NE
("interface subprogram & must be overridden", T, Subp);
-- Examine primitive operations of synchronized type to find
-- homonyms that have the wrong profile.
declare
Prim : Entity_Id;
begin
Prim := First_Entity (Corresponding_Concurrent_Type (T));
while Present (Prim) loop
if Chars (Prim) = Chars (Subp) then
Error_Msg_NE
("profile is not type conformant with prefixed "
& "view profile of inherited operation&",
Prim, Subp);
end if;
Next_Entity (Prim);
end loop;
end;
end if;
else
Error_Msg_Node_2 := T;
Error_Msg_N
("abstract subprogram& not allowed for type&", Subp);
-- Also post unconditional warning on the type (unconditional
-- so that if there are more than one of these cases, we get
-- them all, and not just the first one).
Error_Msg_Node_2 := Subp;
Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
end if;
-- A subprogram subject to pragma Extensions_Visible with value
-- "True" cannot override a subprogram subject to the same pragma
-- with value "False" (SPARK RM 6.1.7(5)).
elsif Extensions_Visible_Status (Subp) = Extensions_Visible_True
and then Present (Overridden_Operation (Subp))
and then Extensions_Visible_Status (Overridden_Operation (Subp)) =
Extensions_Visible_False
then
Error_Msg_Sloc := Sloc (Overridden_Operation (Subp));
Error_Msg_N
("subprogram & with Extensions_Visible True cannot override "
& "subprogram # with Extensions_Visible False", Subp);
end if;
-- Ada 2012 (AI05-0030): Perform checks related to pragma Implemented
-- Subp is an expander-generated procedure which maps an interface
-- alias to a protected wrapper. The interface alias is flagged by
-- pragma Implemented. Ensure that Subp is a procedure when the
-- implementation kind is By_Protected_Procedure or an entry when
-- By_Entry.
if Ada_Version >= Ada_2012
and then Is_Hidden (Subp)
and then Present (Interface_Alias (Subp))
and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
then
Check_Pragma_Implemented (Subp);
end if;
-- Subp is an interface primitive which overrides another interface
-- primitive marked with pragma Implemented.
if Ada_Version >= Ada_2012
and then Present (Overridden_Operation (Subp))
and then Has_Rep_Pragma
(Overridden_Operation (Subp), Name_Implemented)
then
-- If the overriding routine is also marked by Implemented, check
-- that the two implementation kinds are conforming.
if Has_Rep_Pragma (Subp, Name_Implemented) then
Check_Pragma_Implemented
(Subp => Subp,
Iface_Subp => Overridden_Operation (Subp));
-- Otherwise the overriding routine inherits the implementation
-- kind from the overridden subprogram.
else
Inherit_Pragma_Implemented
(Subp => Subp,
Iface_Subp => Overridden_Operation (Subp));
end if;
end if;
-- Ada 2005 (AI95-0414) and Ada 2022 (AI12-0269): Diagnose failure to
-- match No_Return in parent, but do it unconditionally in Ada 95 too
-- for procedures, since this is our pragma.
if Present (Overridden_Operation (Subp))
and then No_Return (Overridden_Operation (Subp))
then
-- If the subprogram is a renaming, check that the renamed
-- subprogram is No_Return.
if Present (Renamed_Or_Alias (Subp)) then
if not No_Return (Renamed_Or_Alias (Subp)) then
Error_Msg_NE ("subprogram & must be No_Return",
Subp,
Renamed_Or_Alias (Subp));
Error_Msg_N ("\since renaming & overrides No_Return "
& "subprogram (RM 6.5.1(6/2))",
Subp);
end if;
-- Make sure that the subprogram itself is No_Return.
elsif not No_Return (Subp) then
Error_Msg_N ("overriding subprogram & must be No_Return", Subp);
Error_Msg_N
("\since overridden subprogram is No_Return (RM 6.5.1(6/2))",
Subp);
end if;
end if;
-- If the operation is a wrapper for a synchronized primitive, it
-- may be called indirectly through a dispatching select. We assume
-- that it will be referenced elsewhere indirectly, and suppress
-- warnings about an unused entity.
if Is_Primitive_Wrapper (Subp)
and then Present (Wrapped_Entity (Subp))
then
Set_Referenced (Wrapped_Entity (Subp));
end if;
Next_Elmt (Elmt);
end loop;
end Check_Abstract_Overriding;
------------------------------------------------
-- Check_Access_Discriminant_Requires_Limited --
------------------------------------------------
procedure Check_Access_Discriminant_Requires_Limited
(D : Node_Id;
Loc : Node_Id)
is
begin
-- A discriminant_specification for an access discriminant shall appear
-- only in the declaration for a task or protected type, or for a type
-- with the reserved word 'limited' in its definition or in one of its
-- ancestors (RM 3.7(10)).
-- AI-0063: The proper condition is that type must be immutably limited,
-- or else be a partial view.
if Nkind (Discriminant_Type (D)) = N_Access_Definition then
if Is_Limited_View (Current_Scope)
or else
(Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
and then Limited_Present (Parent (Current_Scope)))
then
null;
else
Error_Msg_N
("access discriminants allowed only for limited types", Loc);
end if;
end if;
end Check_Access_Discriminant_Requires_Limited;
-----------------------------------
-- Check_Aliased_Component_Types --
-----------------------------------
procedure Check_Aliased_Component_Types (T : Entity_Id) is
C : Entity_Id;
begin
-- ??? Also need to check components of record extensions, but not
-- components of protected types (which are always limited).
-- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
-- types to be unconstrained. This is safe because it is illegal to
-- create access subtypes to such types with explicit discriminant
-- constraints.
if not Is_Limited_Type (T) then
if Ekind (T) = E_Record_Type then
C := First_Component (T);
while Present (C) loop
if Is_Aliased (C)
and then Has_Discriminants (Etype (C))
and then not Is_Constrained (Etype (C))
and then not In_Instance_Body
and then Ada_Version < Ada_2005
then
Error_Msg_N
("aliased component must be constrained (RM 3.6(11))",
C);
end if;
Next_Component (C);
end loop;
elsif Ekind (T) = E_Array_Type then
if Has_Aliased_Components (T)
and then Has_Discriminants (Component_Type (T))
and then not Is_Constrained (Component_Type (T))
and then not In_Instance_Body
and then Ada_Version < Ada_2005
then
Error_Msg_N
("aliased component type must be constrained (RM 3.6(11))",
T);
end if;
end if;
end if;
end Check_Aliased_Component_Types;
--------------------------------------
-- Check_Anonymous_Access_Component --
--------------------------------------
procedure Check_Anonymous_Access_Component
(Typ_Decl : Node_Id;
Typ : Entity_Id;
Prev : Entity_Id;
Comp_Def : Node_Id;
Access_Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Comp_Def);
Anon_Access : Entity_Id;
Acc_Def : Node_Id;
Decl : Node_Id;
Type_Def : Node_Id;
procedure Build_Incomplete_Type_Declaration;
-- If the record type contains components that include an access to the
-- current record, then create an incomplete type declaration for the
-- record, to be used as the designated type of the anonymous access.
-- This is done only once, and only if there is no previous partial
-- view of the type.
function Designates_T (Subt : Node_Id) return Boolean;
-- Check whether a node designates the enclosing record type, or 'Class
-- of that type
function Mentions_T (Acc_Def : Node_Id) return Boolean;
-- Check whether an access definition includes a reference to
-- the enclosing record type. The reference can be a subtype mark
-- in the access definition itself, a 'Class attribute reference, or
-- recursively a reference appearing in a parameter specification
-- or result definition of an access_to_subprogram definition.
--------------------------------------
-- Build_Incomplete_Type_Declaration --
--------------------------------------
procedure Build_Incomplete_Type_Declaration is
Decl : Node_Id;
Inc_T : Entity_Id;
H : Entity_Id;
-- Is_Tagged indicates whether the type is tagged. It is tagged if
-- it's "is new ... with record" or else "is tagged record ...".
Typ_Def : constant Node_Id :=
(if Nkind (Typ_Decl) = N_Full_Type_Declaration
then Type_Definition (Typ_Decl) else Empty);
Is_Tagged : constant Boolean :=
Present (Typ_Def)
and then
((Nkind (Typ_Def) = N_Derived_Type_Definition
and then
Present (Record_Extension_Part (Typ_Def)))
or else
(Nkind (Typ_Def) = N_Record_Definition
and then Tagged_Present (Typ_Def)));
begin
-- If there is a previous partial view, no need to create a new one
-- If the partial view, given by Prev, is incomplete, If Prev is
-- a private declaration, full declaration is flagged accordingly.
if Prev /= Typ then
if Is_Tagged then
Make_Class_Wide_Type (Prev);
Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
Set_Etype (Class_Wide_Type (Typ), Typ);
end if;
return;
elsif Has_Private_Declaration (Typ) then
-- If we refer to T'Class inside T, and T is the completion of a
-- private type, then make sure the class-wide type exists.
if Is_Tagged then
Make_Class_Wide_Type (Typ);
end if;
return;
-- If there was a previous anonymous access type, the incomplete
-- type declaration will have been created already.
elsif Present (Current_Entity (Typ))
and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
and then Full_View (Current_Entity (Typ)) = Typ
then
if Is_Tagged
and then Comes_From_Source (Current_Entity (Typ))
and then not Is_Tagged_Type (Current_Entity (Typ))
then
Make_Class_Wide_Type (Typ);
Error_Msg_N
("incomplete view of tagged type should be declared tagged??",
Parent (Current_Entity (Typ)));
end if;
return;
else
Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
-- Type has already been inserted into the current scope. Remove
-- it, and add incomplete declaration for type, so that subsequent
-- anonymous access types can use it. The entity is unchained from
-- the homonym list and from immediate visibility. After analysis,
-- the entity in the incomplete declaration becomes immediately
-- visible in the record declaration that follows.
H := Current_Entity (Typ);
if H = Typ then
Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
else
while Present (Homonym (H)) and then Homonym (H) /= Typ loop
H := Homonym (Typ);
end loop;
Set_Homonym (H, Homonym (Typ));
end if;
Insert_Before (Typ_Decl, Decl);
Analyze (Decl);
Set_Full_View (Inc_T, Typ);
Set_Incomplete_View (Typ_Decl, Inc_T);
-- If the type is tagged, create a common class-wide type for
-- both views, and set the Etype of the class-wide type to the
-- full view.
if Is_Tagged then
Make_Class_Wide_Type (Inc_T);
Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
Set_Etype (Class_Wide_Type (Typ), Typ);
end if;
-- If the scope is a package with a limited view, create a shadow
-- entity for the incomplete type like Build_Limited_Views, so as
-- to make it possible for Remove_Limited_With_Unit to reinstall
-- this incomplete type as the visible entity.
if Ekind (Scope (Inc_T)) = E_Package
and then Present (Limited_View (Scope (Inc_T)))
then
declare
Shadow : constant Entity_Id := Make_Temporary (Loc, 'Z');
begin
-- This is modeled on Build_Shadow_Entity
Set_Chars (Shadow, Chars (Inc_T));
Set_Parent (Shadow, Decl);
Decorate_Type (Shadow, Scope (Inc_T), Is_Tagged);
Set_Is_Internal (Shadow);
Set_From_Limited_With (Shadow);
Set_Non_Limited_View (Shadow, Inc_T);
Set_Private_Dependents (Shadow, New_Elmt_List);
if Is_Tagged then
Set_Non_Limited_View
(Class_Wide_Type (Shadow), Class_Wide_Type (Inc_T));
end if;
Append_Entity (Shadow, Limited_View (Scope (Inc_T)));
end;
end if;
end if;
end Build_Incomplete_Type_Declaration;
------------------
-- Designates_T --
------------------
function Designates_T (Subt : Node_Id) return Boolean is
Type_Id : constant Name_Id := Chars (Typ);
function Names_T (Nam : Node_Id) return Boolean;
-- The record type has not been introduced in the current scope
-- yet, so we must examine the name of the type itself, either
-- an identifier T, or an expanded name of the form P.T, where
-- P denotes the current scope.
-------------
-- Names_T --
-------------
function Names_T (Nam : Node_Id) return Boolean is
begin
if Nkind (Nam) = N_Identifier then
return Chars (Nam) = Type_Id;
elsif Nkind (Nam) = N_Selected_Component then
if Chars (Selector_Name (Nam)) = Type_Id then
if Nkind (Prefix (Nam)) = N_Identifier then
return Chars (Prefix (Nam)) = Chars (Current_Scope);
elsif Nkind (Prefix (Nam)) = N_Selected_Component then
return Chars (Selector_Name (Prefix (Nam))) =
Chars (Current_Scope);
else
return False;
end if;
else
return False;
end if;
else
return False;
end if;
end Names_T;
-- Start of processing for Designates_T
begin
if Nkind (Subt) = N_Identifier then
return Chars (Subt) = Type_Id;
-- Reference can be through an expanded name which has not been
-- analyzed yet, and which designates enclosing scopes.
elsif Nkind (Subt) = N_Selected_Component then
if Names_T (Subt) then
return True;
-- Otherwise it must denote an entity that is already visible.
-- The access definition may name a subtype of the enclosing
-- type, if there is a previous incomplete declaration for it.
else
Find_Selected_Component (Subt);
return
Is_Entity_Name (Subt)
and then Scope (Entity (Subt)) = Current_Scope
and then
(Chars (Base_Type (Entity (Subt))) = Type_Id
or else
(Is_Class_Wide_Type (Entity (Subt))
and then
Chars (Etype (Base_Type (Entity (Subt)))) =
Type_Id));
end if;
-- A reference to the current type may appear as the prefix of
-- a 'Class attribute.
elsif Nkind (Subt) = N_Attribute_Reference
and then Attribute_Name (Subt) = Name_Class
then
return Names_T (Prefix (Subt));
else
return False;
end if;
end Designates_T;
----------------
-- Mentions_T --
----------------
function Mentions_T (Acc_Def : Node_Id) return Boolean is
Param_Spec : Node_Id;
Acc_Subprg : constant Node_Id :=
Access_To_Subprogram_Definition (Acc_Def);
begin
if No (Acc_Subprg) then
return Designates_T (Subtype_Mark (Acc_Def));
end if;
-- Component is an access_to_subprogram: examine its formals,
-- and result definition in the case of an access_to_function.
Param_Spec := First (Parameter_Specifications (Acc_Subprg));
while Present (Param_Spec) loop
if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
and then Mentions_T (Parameter_Type (Param_Spec))
then
return True;
elsif Designates_T (Parameter_Type (Param_Spec)) then
return True;
end if;
Next (Param_Spec);
end loop;
if Nkind (Acc_Subprg) = N_Access_Function_Definition then
if Nkind (Result_Definition (Acc_Subprg)) =
N_Access_Definition
then
return Mentions_T (Result_Definition (Acc_Subprg));
else
return Designates_T (Result_Definition (Acc_Subprg));
end if;
end if;
return False;
end Mentions_T;
-- Start of processing for Check_Anonymous_Access_Component
begin
if Present (Access_Def) and then Mentions_T (Access_Def) then
Acc_Def := Access_To_Subprogram_Definition (Access_Def);
Build_Incomplete_Type_Declaration;
Anon_Access := Make_Temporary (Loc, 'S');
-- Create a declaration for the anonymous access type: either
-- an access_to_object or an access_to_subprogram.
if Present (Acc_Def) then
if Nkind (Acc_Def) = N_Access_Function_Definition then
Type_Def :=
Make_Access_Function_Definition (Loc,
Parameter_Specifications =>
Parameter_Specifications (Acc_Def),
Result_Definition => Result_Definition (Acc_Def));
else
Type_Def :=
Make_Access_Procedure_Definition (Loc,
Parameter_Specifications =>
Parameter_Specifications (Acc_Def));
end if;
else
Type_Def :=
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
Relocate_Node (Subtype_Mark (Access_Def)));
Set_Constant_Present (Type_Def, Constant_Present (Access_Def));
Set_All_Present (Type_Def, All_Present (Access_Def));
end if;
Set_Null_Exclusion_Present
(Type_Def, Null_Exclusion_Present (Access_Def));
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Anon_Access,
Type_Definition => Type_Def);
Insert_Before (Typ_Decl, Decl);
Analyze (Decl);
-- At first sight we could add here the extra formals of an access to
-- subprogram; however, it must delayed till the freeze point so that
-- we know the convention.
if Nkind (Comp_Def) = N_Component_Definition then
Rewrite (Comp_Def,
Make_Component_Definition (Loc,
Subtype_Indication => New_Occurrence_Of (Anon_Access, Loc)));
else
pragma Assert (Nkind (Comp_Def) = N_Discriminant_Specification);
Rewrite (Comp_Def,
Make_Discriminant_Specification (Loc,
Defining_Identifier => Defining_Identifier (Comp_Def),
Discriminant_Type => New_Occurrence_Of (Anon_Access, Loc)));
end if;
if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
Mutate_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
else
Mutate_Ekind (Anon_Access, E_Anonymous_Access_Type);
end if;
Set_Is_Local_Anonymous_Access (Anon_Access);
end if;
end Check_Anonymous_Access_Component;
---------------------------------------
-- Check_Anonymous_Access_Components --
---------------------------------------
procedure Check_Anonymous_Access_Components
(Typ_Decl : Node_Id;
Typ : Entity_Id;
Prev : Entity_Id;
Comp_List : Node_Id)
is
Comp : Node_Id;
begin
if No (Comp_List) then
return;
end if;
Comp := First (Component_Items (Comp_List));
while Present (Comp) loop
if Nkind (Comp) = N_Component_Declaration then
Check_Anonymous_Access_Component
(Typ_Decl, Typ, Prev,
Component_Definition (Comp),
Access_Definition (Component_Definition (Comp)));
end if;
Next (Comp);
end loop;
if Present (Variant_Part (Comp_List)) then
declare
V : Node_Id;
begin
V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
while Present (V) loop
Check_Anonymous_Access_Components
(Typ_Decl, Typ, Prev, Component_List (V));
Next_Non_Pragma (V);
end loop;
end;
end if;
end Check_Anonymous_Access_Components;
----------------------
-- Check_Completion --
----------------------
procedure Check_Completion (Body_Id : Node_Id := Empty) is
E : Entity_Id;
procedure Post_Error;
-- Post error message for lack of completion for entity E
----------------
-- Post_Error --
----------------
procedure Post_Error is
procedure Missing_Body;
-- Output missing body message
------------------
-- Missing_Body --
------------------
procedure Missing_Body is
begin
-- Spec is in same unit, so we can post on spec
if In_Same_Source_Unit (Body_Id, E) then
Error_Msg_N ("missing body for &", E);
-- Spec is in a separate unit, so we have to post on the body
else
Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
end if;
end Missing_Body;
-- Start of processing for Post_Error
begin
if not Comes_From_Source (E) then
if Ekind (E) in E_Task_Type | E_Protected_Type then
-- It may be an anonymous protected type created for a
-- single variable. Post error on variable, if present.
declare
Var : Entity_Id;
begin
Var := First_Entity (Current_Scope);
while Present (Var) loop
exit when Etype (Var) = E
and then Comes_From_Source (Var);
Next_Entity (Var);
end loop;
if Present (Var) then
E := Var;
end if;
end;
end if;
end if;
-- If a generated entity has no completion, then either previous
-- semantic errors have disabled the expansion phase, or else we had
-- missing subunits, or else we are compiling without expansion,
-- or else something is very wrong.
if not Comes_From_Source (E) then
pragma Assert
(Serious_Errors_Detected > 0
or else Configurable_Run_Time_Violations > 0
or else Subunits_Missing
or else not Expander_Active);
return;
-- Here for source entity
else
-- Here if no body to post the error message, so we post the error
-- on the declaration that has no completion. This is not really
-- the right place to post it, think about this later ???
if No (Body_Id) then
if Is_Type (E) then
Error_Msg_NE
("missing full declaration for }", Parent (E), E);
else
Error_Msg_NE ("missing body for &", Parent (E), E);
end if;
-- Package body has no completion for a declaration that appears
-- in the corresponding spec. Post error on the body, with a
-- reference to the non-completed declaration.
else
Error_Msg_Sloc := Sloc (E);
if Is_Type (E) then
Error_Msg_NE ("missing full declaration for }!", Body_Id, E);
elsif Is_Overloadable (E)
and then Current_Entity_In_Scope (E) /= E
then
-- It may be that the completion is mistyped and appears as
-- a distinct overloading of the entity.
declare
Candidate : constant Entity_Id :=
Current_Entity_In_Scope (E);
Decl : constant Node_Id :=
Unit_Declaration_Node (Candidate);
begin
if Is_Overloadable (Candidate)
and then Ekind (Candidate) = Ekind (E)
and then Nkind (Decl) = N_Subprogram_Body
and then Acts_As_Spec (Decl)
then
Check_Type_Conformant (Candidate, E);
else
Missing_Body;
end if;
end;
else
Missing_Body;
end if;
end if;
end if;
end Post_Error;
-- Local variables
Pack_Id : constant Entity_Id := Current_Scope;
-- Start of processing for Check_Completion
begin
E := First_Entity (Pack_Id);
while Present (E) loop
if Is_Intrinsic_Subprogram (E) then
null;
-- The following situation requires special handling: a child unit
-- that appears in the context clause of the body of its parent:
-- procedure Parent.Child (...);
-- with Parent.Child;
-- package body Parent is
-- Here Parent.Child appears as a local entity, but should not be
-- flagged as requiring completion, because it is a compilation
-- unit.
-- Ignore missing completion for a subprogram that does not come from
-- source (including the _Call primitive operation of RAS types,
-- which has to have the flag Comes_From_Source for other purposes):
-- we assume that the expander will provide the missing completion.
-- In case of previous errors, other expansion actions that provide
-- bodies for null procedures with not be invoked, so inhibit message
-- in those cases.
-- Note that E_Operator is not in the list that follows, because
-- this kind is reserved for predefined operators, that are
-- intrinsic and do not need completion.
elsif Ekind (E) in E_Function
| E_Procedure
| E_Generic_Function
| E_Generic_Procedure
then
if Has_Completion (E) then
null;
elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
null;
elsif Is_Subprogram (E)
and then (not Comes_From_Source (E)
or else Chars (E) = Name_uCall)
then
null;
elsif
Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
then
null;
elsif Nkind (Parent (E)) = N_Procedure_Specification
and then Null_Present (Parent (E))
and then Serious_Errors_Detected > 0
then
null;
else
Post_Error;
end if;
elsif Is_Entry (E) then
if not Has_Completion (E)
and then Ekind (Scope (E)) = E_Protected_Type
then
Post_Error;
end if;
elsif Is_Package_Or_Generic_Package (E) then
if Unit_Requires_Body (E) then
if not Has_Completion (E)
and then Nkind (Parent (Unit_Declaration_Node (E))) /=
N_Compilation_Unit
then
Post_Error;
end if;
elsif not Is_Child_Unit (E) then
May_Need_Implicit_Body (E);
end if;
-- A formal incomplete type (Ada 2012) does not require a completion;
-- other incomplete type declarations do.
elsif Ekind (E) = E_Incomplete_Type then
if No (Underlying_Type (E))
and then not Is_Generic_Type (E)
then
Post_Error;
end if;
elsif Ekind (E) in E_Task_Type | E_Protected_Type then
if not Has_Completion (E) then
Post_Error;
end if;
-- A single task declared in the current scope is a constant, verify
-- that the body of its anonymous type is in the same scope. If the
-- task is defined elsewhere, this may be a renaming declaration for
-- which no completion is needed.
elsif Ekind (E) = E_Constant then
if Ekind (Etype (E)) = E_Task_Type
and then not Has_Completion (Etype (E))
and then Scope (Etype (E)) = Current_Scope
then
Post_Error;
end if;
elsif Ekind (E) = E_Record_Type then
if Is_Tagged_Type (E) then
Check_Abstract_Overriding (E);
Check_Conventions (E);
end if;
Check_Aliased_Component_Types (E);
elsif Ekind (E) = E_Array_Type then
Check_Aliased_Component_Types (E);
end if;
Next_Entity (E);
end loop;
end Check_Completion;
-------------------------------------
-- Check_Constraining_Discriminant --
-------------------------------------
procedure Check_Constraining_Discriminant (New_Disc, Old_Disc : Entity_Id)
is
New_Type : constant Entity_Id := Etype (New_Disc);
Old_Type : Entity_Id;
begin
-- If the record type contains an array constrained by the discriminant
-- but with some different bound, the compiler tries to create a smaller
-- range for the discriminant type (see exp_ch3.Adjust_Discriminants).
-- In this case, where the discriminant type is a scalar type, the check
-- must use the original discriminant type in the parent declaration.
if Is_Scalar_Type (New_Type) then
Old_Type := Entity (Discriminant_Type (Parent (Old_Disc)));
else
Old_Type := Etype (Old_Disc);
end if;
if not Subtypes_Statically_Compatible (New_Type, Old_Type) then
Error_Msg_N
("subtype must be statically compatible with parent discriminant",
New_Disc);
if not Predicates_Compatible (New_Type, Old_Type) then
Error_Msg_N
("\subtype predicate is not compatible with parent discriminant",
New_Disc);
end if;
end if;
end Check_Constraining_Discriminant;
------------------------------------
-- Check_CPP_Type_Has_No_Defaults --
------------------------------------
procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
Clist : Node_Id;
Comp : Node_Id;
begin
-- Obtain the component list
if Nkind (Tdef) = N_Record_Definition then
Clist := Component_List (Tdef);
else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
Clist := Component_List (Record_Extension_Part (Tdef));
end if;
-- Check all components to ensure no default expressions
if Present (Clist) then
Comp := First (Component_Items (Clist));
while Present (Comp) loop
if Present (Expression (Comp)) then
Error_Msg_N
("component of imported 'C'P'P type cannot have "
& "default expression", Expression (Comp));
end if;
Next (Comp);
end loop;
end if;
end Check_CPP_Type_Has_No_Defaults;
----------------------------
-- Check_Delta_Expression --
----------------------------
procedure Check_Delta_Expression (E : Node_Id) is
begin
if not (Is_Real_Type (Etype (E))) then
Wrong_Type (E, Any_Real);
elsif not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used for delta value!", E);
elsif not UR_Is_Positive (Expr_Value_R (E)) then
Error_Msg_N ("delta expression must be positive", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the real 0.1, which should prevent further errors.
Rewrite (E,
Make_Real_Literal (Sloc (E), Ureal_Tenth));
Analyze_And_Resolve (E, Standard_Float);
end Check_Delta_Expression;
-----------------------------
-- Check_Digits_Expression --
-----------------------------
procedure Check_Digits_Expression (E : Node_Id) is
begin
if not (Is_Integer_Type (Etype (E))) then
Wrong_Type (E, Any_Integer);
elsif not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used for digits value!", E);
elsif Expr_Value (E) <= 0 then
Error_Msg_N ("digits value must be greater than zero", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the integer 1, which should prevent further errors.
Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
Analyze_And_Resolve (E, Standard_Integer);
end Check_Digits_Expression;
--------------------------
-- Check_Initialization --
--------------------------
procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
begin
-- Special processing for limited types
if Is_Limited_Type (T)
and then not In_Instance
and then not In_Inlined_Body
then
if not OK_For_Limited_Init (T, Exp) then
-- In GNAT mode, this is just a warning, to allow it to be evilly
-- turned off. Otherwise it is a real error.
if GNAT_Mode then
Error_Msg_N
("??cannot initialize entities of limited type!", Exp);
elsif Ada_Version < Ada_2005 then
-- The side effect removal machinery may generate illegal Ada
-- code to avoid the usage of access types and 'reference in
-- SPARK mode. Since this is legal code with respect to theorem
-- proving, do not emit the error.
if GNATprove_Mode
and then Nkind (Exp) = N_Function_Call
and then Nkind (Parent (Exp)) = N_Object_Declaration
and then not Comes_From_Source
(Defining_Identifier (Parent (Exp)))
then
null;
else
Error_Msg_N
("cannot initialize entities of limited type", Exp);
Explain_Limited_Type (T, Exp);
end if;
else
-- Specialize error message according to kind of illegal
-- initial expression. We check the Original_Node to cover
-- cases where the initialization expression of an object
-- declaration generated by the compiler has been rewritten
-- (such as for dispatching calls).
if Nkind (Original_Node (Exp)) = N_Type_Conversion
and then
Nkind (Expression (Original_Node (Exp))) = N_Function_Call
then
-- No error for internally-generated object declarations,
-- which can come from build-in-place assignment statements.
if Nkind (Parent (Exp)) = N_Object_Declaration
and then not Comes_From_Source
(Defining_Identifier (Parent (Exp)))
then
null;
else
Error_Msg_N
("illegal context for call to function with limited "
& "result", Exp);
end if;
else
Error_Msg_N
("initialization of limited object requires aggregate or "
& "function call", Exp);
end if;
end if;
end if;
end if;
-- In gnatc or gnatprove mode, make sure set Do_Range_Check flag gets
-- set unless we can be sure that no range check is required.
if not Expander_Active
and then Is_Scalar_Type (T)
and then not Is_In_Range (Exp, T, Assume_Valid => True)
then
Set_Do_Range_Check (Exp);
end if;
end Check_Initialization;
----------------------
-- Check_Interfaces --
----------------------
procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
Iface : Node_Id;
Iface_Def : Node_Id;
Iface_Typ : Entity_Id;
Parent_Node : Node_Id;
Is_Task : Boolean := False;
-- Set True if parent type or any progenitor is a task interface
Is_Protected : Boolean := False;
-- Set True if parent type or any progenitor is a protected interface
procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
-- Check that a progenitor is compatible with declaration. If an error
-- message is output, it is posted on Error_Node.
------------------
-- Check_Ifaces --
------------------
procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
Iface_Id : constant Entity_Id :=
Defining_Identifier (Parent (Iface_Def));
Type_Def : Node_Id;
begin
if Nkind (N) = N_Private_Extension_Declaration then
Type_Def := N;
else
Type_Def := Type_Definition (N);
end if;
if Is_Task_Interface (Iface_Id) then
Is_Task := True;
elsif Is_Protected_Interface (Iface_Id) then
Is_Protected := True;
end if;
if Is_Synchronized_Interface (Iface_Id) then
-- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
-- extension derived from a synchronized interface must explicitly
-- be declared synchronized, because the full view will be a
-- synchronized type.
if Nkind (N) = N_Private_Extension_Declaration then
if not Synchronized_Present (N) then
Error_Msg_NE
("private extension of& must be explicitly synchronized",
N, Iface_Id);
end if;
-- However, by 3.9.4(16/2), a full type that is a record extension
-- is never allowed to derive from a synchronized interface (note
-- that interfaces must be excluded from this check, because those
-- are represented by derived type definitions in some cases).
elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
and then not Interface_Present (Type_Definition (N))
then
Error_Msg_N ("record extension cannot derive from synchronized "
& "interface", Error_Node);
end if;
end if;
-- Check that the characteristics of the progenitor are compatible
-- with the explicit qualifier in the declaration.
-- The check only applies to qualifiers that come from source.
-- Limited_Present also appears in the declaration of corresponding
-- records, and the check does not apply to them.
if Limited_Present (Type_Def)
and then not
Is_Concurrent_Record_Type (Defining_Identifier (N))
then
if Is_Limited_Interface (Parent_Type)
and then not Is_Limited_Interface (Iface_Id)
then
Error_Msg_NE
("progenitor & must be limited interface",
Error_Node, Iface_Id);
elsif
(Task_Present (Iface_Def)
or else Protected_Present (Iface_Def)
or else Synchronized_Present (Iface_Def))
and then Nkind (N) /= N_Private_Extension_Declaration
and then not Error_Posted (N)
then
Error_Msg_NE
("progenitor & must be limited interface",
Error_Node, Iface_Id);
end if;
-- Protected interfaces can only inherit from limited, synchronized
-- or protected interfaces.
elsif Nkind (N) = N_Full_Type_Declaration
and then Protected_Present (Type_Def)
then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
or else Protected_Present (Iface_Def)
then
null;
elsif Task_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
& "from task interface", Error_Node);
else
Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
& "from non-limited interface", Error_Node);
end if;
-- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
-- limited and synchronized.
elsif Synchronized_Present (Type_Def) then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
then
null;
elsif Protected_Present (Iface_Def)
and then Nkind (N) /= N_Private_Extension_Declaration
then
Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
& "from protected interface", Error_Node);
elsif Task_Present (Iface_Def)
and then Nkind (N) /= N_Private_Extension_Declaration
then
Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
& "from task interface", Error_Node);
elsif not Is_Limited_Interface (Iface_Id) then
Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
& "from non-limited interface", Error_Node);
end if;
-- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
-- synchronized or task interfaces.
elsif Nkind (N) = N_Full_Type_Declaration
and then Task_Present (Type_Def)
then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
or else Task_Present (Iface_Def)
then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
& "protected interface", Error_Node);
else
Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
& "non-limited interface", Error_Node);
end if;
end if;
end Check_Ifaces;
-- Start of processing for Check_Interfaces
begin
if Is_Interface (Parent_Type) then
if Is_Task_Interface (Parent_Type) then
Is_Task := True;
elsif Is_Protected_Interface (Parent_Type) then
Is_Protected := True;
end if;
end if;
if Nkind (N) = N_Private_Extension_Declaration then
-- Check that progenitors are compatible with declaration
Iface := First (Interface_List (Def));
while Present (Iface) loop
Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
Parent_Node := Parent (Base_Type (Iface_Typ));
Iface_Def := Type_Definition (Parent_Node);
if not Is_Interface (Iface_Typ) then
Diagnose_Interface (Iface, Iface_Typ);
else
Check_Ifaces (Iface_Def, Iface);
end if;
Next (Iface);
end loop;
if Is_Task and Is_Protected then
Error_Msg_N
("type cannot derive from task and protected interface", N);
end if;
return;
end if;
-- Full type declaration of derived type.
-- Check compatibility with parent if it is interface type
if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
and then Is_Interface (Parent_Type)
then
Parent_Node := Parent (Parent_Type);
-- More detailed checks for interface varieties
Check_Ifaces
(Iface_Def => Type_Definition (Parent_Node),
Error_Node => Subtype_Indication (Type_Definition (N)));
end if;
Iface := First (Interface_List (Def));
while Present (Iface) loop
Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
Parent_Node := Parent (Base_Type (Iface_Typ));
Iface_Def := Type_Definition (Parent_Node);
if not Is_Interface (Iface_Typ) then
Diagnose_Interface (Iface, Iface_Typ);
else
-- "The declaration of a specific descendant of an interface
-- type freezes the interface type" RM 13.14
Freeze_Before (N, Iface_Typ);
Check_Ifaces (Iface_Def, Error_Node => Iface);
end if;
Next (Iface);
end loop;
if Is_Task and Is_Protected then
Error_Msg_N
("type cannot derive from task and protected interface", N);
end if;
end Check_Interfaces;
------------------------------------
-- Check_Or_Process_Discriminants --
------------------------------------
-- If an incomplete or private type declaration was already given for the
-- type, the discriminants may have already been processed if they were
-- present on the incomplete declaration. In this case a full conformance
-- check has been performed in Find_Type_Name, and we then recheck here
-- some properties that can't be checked on the partial view alone.
-- Otherwise we call Process_Discriminants.
procedure Check_Or_Process_Discriminants
(N : Node_Id;
T : Entity_Id;
Prev : Entity_Id := Empty)
is
begin
if Has_Discriminants (T) then
-- Discriminants are already set on T if they were already present
-- on the partial view. Make them visible to component declarations.
declare
D : Entity_Id;
-- Discriminant on T (full view) referencing expr on partial view
Prev_D : Entity_Id;
-- Entity of corresponding discriminant on partial view
New_D : Node_Id;
-- Discriminant specification for full view, expression is
-- the syntactic copy on full view (which has been checked for
-- conformance with partial view), only used here to post error
-- message.
begin
D := First_Discriminant (T);
New_D := First (Discriminant_Specifications (N));
while Present (D) loop
Prev_D := Current_Entity (D);
Set_Current_Entity (D);
Set_Is_Immediately_Visible (D);
Set_Homonym (D, Prev_D);
-- Handle the case where there is an untagged partial view and
-- the full view is tagged: must disallow discriminants with
-- defaults, unless compiling for Ada 2012, which allows a
-- limited tagged type to have defaulted discriminants (see
-- AI05-0214). However, suppress error here if it was already
-- reported on the default expression of the partial view.
if Is_Tagged_Type (T)
and then Present (Expression (Parent (D)))
and then (not Is_Limited_Type (Current_Scope)
or else Ada_Version < Ada_2012)
and then not Error_Posted (Expression (Parent (D)))
then
if Ada_Version >= Ada_2012 then
Error_Msg_N
("discriminants of nonlimited tagged type cannot have "
& "defaults",
Expression (New_D));
else
Error_Msg_N
("discriminants of tagged type cannot have defaults",
Expression (New_D));
end if;
end if;
-- Ada 2005 (AI-230): Access discriminant allowed in
-- non-limited record types.
if Ada_Version < Ada_2005 then
-- This restriction gets applied to the full type here. It
-- has already been applied earlier to the partial view.
Check_Access_Discriminant_Requires_Limited (Parent (D), N);
end if;
Next_Discriminant (D);
Next (New_D);
end loop;
end;
elsif Present (Discriminant_Specifications (N)) then
Process_Discriminants (N, Prev);
end if;
end Check_Or_Process_Discriminants;
----------------------
-- Check_Real_Bound --
----------------------
procedure Check_Real_Bound (Bound : Node_Id) is
begin
if not Is_Real_Type (Etype (Bound)) then
Error_Msg_N
("bound in real type definition must be of real type", Bound);
elsif not Is_OK_Static_Expression (Bound) then
Flag_Non_Static_Expr
("non-static expression used for real type bound!", Bound);
else
return;
end if;
Rewrite
(Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
Analyze (Bound);
Resolve (Bound, Standard_Float);
end Check_Real_Bound;
------------------------------
-- Complete_Private_Subtype --
------------------------------
procedure Complete_Private_Subtype
(Priv : Entity_Id;
Full : Entity_Id;
Full_Base : Entity_Id;
Related_Nod : Node_Id)
is
Save_Next_Entity : Entity_Id;
Save_Homonym : Entity_Id;
begin
-- Set semantic attributes for (implicit) private subtype completion.
-- If the full type has no discriminants, then it is a copy of the
-- full view of the base. Otherwise, it is a subtype of the base with
-- a possible discriminant constraint. Save and restore the original
-- Next_Entity field of full to ensure that the calls to Copy_Node do
-- not corrupt the entity chain.
Save_Next_Entity := Next_Entity (Full);
Save_Homonym := Homonym (Priv);
if Is_Private_Type (Full_Base)
or else Is_Record_Type (Full_Base)
or else Is_Concurrent_Type (Full_Base)
then
Copy_Node (Priv, Full);
-- Note that the Etype of the full view is the same as the Etype of
-- the partial view. In this fashion, the subtype has access to the
-- correct view of the parent.
Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
Set_Has_Unknown_Discriminants
(Full, Has_Unknown_Discriminants (Full_Base));
Set_First_Entity (Full, First_Entity (Full_Base));
Set_Last_Entity (Full, Last_Entity (Full_Base));
-- If the underlying base type is constrained, we know that the
-- full view of the subtype is constrained as well (the converse
-- is not necessarily true).
if Is_Constrained (Full_Base) then
Set_Is_Constrained (Full);
end if;
else
Copy_Node (Full_Base, Full);
-- The following subtlety with the Etype of the full view needs to be
-- taken into account here. One could think that it must naturally be
-- set to the base type of the full base:
-- Set_Etype (Full, Base_Type (Full_Base));
-- so that the full view becomes a subtype of the full base when the
-- latter is a base type, which must for example happen when the full
-- base is declared as derived type. That's also correct if the full
-- base is declared as an array type, or a floating-point type, or a
-- fixed-point type, or a signed integer type, as these declarations
-- create an implicit base type and a first subtype so the Etype of
-- the full views must be the implicit base type. But that's wrong
-- if the full base is declared as an access type, or an enumeration
-- type, or a modular integer type, as these declarations directly
-- create a base type, i.e. with Etype pointing to itself. Moreover
-- the full base being declared in the private part, i.e. when the
-- views are swapped, the end result is that the Etype of the full
-- base is set to its private view in this case and that we need to
-- propagate this setting to the full view in order for the subtype
-- to be compatible with the base type.
if Is_Base_Type (Full_Base)
and then (Is_Derived_Type (Full_Base)
or else Ekind (Full_Base) in Array_Kind
or else Ekind (Full_Base) in Fixed_Point_Kind
or else Ekind (Full_Base) in Float_Kind
or else Ekind (Full_Base) in Signed_Integer_Kind)
then
Set_Etype (Full, Full_Base);
end if;
Set_Chars (Full, Chars (Priv));
Set_Sloc (Full, Sloc (Priv));
Conditional_Delay (Full, Priv);
end if;
Link_Entities (Full, Save_Next_Entity);
Set_Homonym (Full, Save_Homonym);
Set_Associated_Node_For_Itype (Full, Related_Nod);
if Ekind (Full) in Incomplete_Or_Private_Kind then
Reinit_Field_To_Zero (Full, F_Private_Dependents);
end if;
-- Set common attributes for all subtypes: kind, convention, etc.
Mutate_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
Set_Convention (Full, Convention (Full_Base));
Set_Is_First_Subtype (Full, False);
Set_Scope (Full, Scope (Priv));
Set_Size_Info (Full, Full_Base);
Copy_RM_Size (To => Full, From => Full_Base);
Set_Is_Itype (Full);
-- A subtype of a private-type-without-discriminants, whose full-view
-- has discriminants with default expressions, is not constrained.
if not Has_Discriminants (Priv) then
Set_Is_Constrained (Full, Is_Constrained (Full_Base));
if Has_Discriminants (Full_Base) then
Set_Discriminant_Constraint
(Full, Discriminant_Constraint (Full_Base));
-- The partial view may have been indefinite, the full view
-- might not be.
Set_Has_Unknown_Discriminants
(Full, Has_Unknown_Discriminants (Full_Base));
end if;
end if;
Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
Set_Depends_On_Private (Full, Has_Private_Component (Full));
-- Freeze the private subtype entity if its parent is delayed, and not
-- already frozen. We skip this processing if the type is an anonymous
-- subtype of a record component, or is the corresponding record of a
-- protected type, since these are processed when the enclosing type
-- is frozen. If the parent type is declared in a nested package then
-- the freezing of the private and full views also happens later.
if not Is_Type (Scope (Full)) then
if Is_Itype (Priv)
and then In_Same_Source_Unit (Full, Full_Base)
and then Scope (Full_Base) /= Scope (Full)
then
Set_Has_Delayed_Freeze (Full);
Set_Has_Delayed_Freeze (Priv);
else
Set_Has_Delayed_Freeze (Full,
Has_Delayed_Freeze (Full_Base)
and then not Is_Frozen (Full_Base));
end if;
end if;
Set_Freeze_Node (Full, Empty);
Set_Is_Frozen (Full, False);
if Has_Discriminants (Full) then
Set_Stored_Constraint_From_Discriminant_Constraint (Full);
Set_Stored_Constraint (Priv, Stored_Constraint (Full));
if Has_Unknown_Discriminants (Full) then
Set_Discriminant_Constraint (Full, No_Elist);
end if;
end if;
if Ekind (Full_Base) = E_Record_Type
and then Has_Discriminants (Full_Base)
and then Has_Discriminants (Priv) -- might not, if errors
and then not Has_Unknown_Discriminants (Priv)
and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
then
Create_Constrained_Components
(Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
-- If the full base is itself derived from private, build a congruent
-- subtype of its underlying full view, for use by the back end.
elsif Is_Private_Type (Full_Base)
and then Present (Underlying_Full_View (Full_Base))
then
declare
Underlying_Full_Base : constant Entity_Id
:= Underlying_Full_View (Full_Base);
Underlying_Full : constant Entity_Id
:= Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
begin
Set_Is_Itype (Underlying_Full);
Set_Associated_Node_For_Itype (Underlying_Full, Related_Nod);
Complete_Private_Subtype
(Priv, Underlying_Full, Underlying_Full_Base, Related_Nod);
Set_Underlying_Full_View (Full, Underlying_Full);
Set_Is_Underlying_Full_View (Underlying_Full);
end;
elsif Is_Record_Type (Full_Base) then
-- Show Full is simply a renaming of Full_Base
Set_Cloned_Subtype (Full, Full_Base);
Set_Is_Limited_Record (Full, Is_Limited_Record (Full_Base));
-- Propagate predicates
Propagate_Predicate_Attributes (Full, Full_Base);
end if;
-- It is unsafe to share the bounds of a scalar type, because the Itype
-- is elaborated on demand, and if a bound is nonstatic, then different
-- orders of elaboration in different units will lead to different
-- external symbols.
if Is_Scalar_Type (Full_Base) then
Set_Scalar_Range (Full,
Make_Range (Sloc (Related_Nod),
Low_Bound =>
Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
High_Bound =>
Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
-- This completion inherits the bounds of the full parent, but if
-- the parent is an unconstrained floating point type, so is the
-- completion.
if Is_Floating_Point_Type (Full_Base) then
Set_Includes_Infinities
(Scalar_Range (Full), Has_Infinities (Full_Base));
end if;
end if;
-- ??? It seems that a lot of fields are missing that should be copied
-- from Full_Base to Full. Here are some that are introduced in a
-- non-disruptive way but a cleanup is necessary.
if Is_Tagged_Type (Full_Base) then
Set_Is_Tagged_Type (Full);
Set_Is_Limited_Record (Full, Is_Limited_Record (Full_Base));
Set_Direct_Primitive_Operations
(Full, Direct_Primitive_Operations (Full_Base));
Set_No_Tagged_Streams_Pragma
(Full, No_Tagged_Streams_Pragma (Full_Base));
if Is_Interface (Full_Base) then
Set_Is_Interface (Full);
Set_Is_Limited_Interface (Full, Is_Limited_Interface (Full_Base));
end if;
-- Inherit class_wide type of full_base in case the partial view was
-- not tagged. Otherwise it has already been created when the private
-- subtype was analyzed.
if No (Class_Wide_Type (Full)) then
Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
end if;
-- If this is a subtype of a protected or task type, constrain its
-- corresponding record, unless this is a subtype without constraints,
-- i.e. a simple renaming as with an actual subtype in an instance.
elsif Is_Concurrent_Type (Full_Base) then
if Has_Discriminants (Full)
and then Present (Corresponding_Record_Type (Full_Base))
and then
not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
then
Set_Corresponding_Record_Type (Full,
Constrain_Corresponding_Record
(Full, Corresponding_Record_Type (Full_Base), Related_Nod));
else
Set_Corresponding_Record_Type (Full,
Corresponding_Record_Type (Full_Base));
end if;
end if;
-- Link rep item chain, and also setting of Has_Predicates from private
-- subtype to full subtype, since we will need these on the full subtype
-- to create the predicate function. Note that the full subtype may
-- already have rep items, inherited from the full view of the base
-- type, so we must be sure not to overwrite these entries.
declare
Append : Boolean;
Item : Node_Id;
Next_Item : Node_Id;
Priv_Item : Node_Id;
begin
Item := First_Rep_Item (Full);
Priv_Item := First_Rep_Item (Priv);
-- If no existing rep items on full type, we can just link directly
-- to the list of items on the private type, if any exist.. Same if
-- the rep items are only those inherited from the base
if (No (Item)
or else Nkind (Item) /= N_Aspect_Specification
or else Entity (Item) = Full_Base)
and then Present (First_Rep_Item (Priv))
then
Set_First_Rep_Item (Full, Priv_Item);
-- Otherwise, search to the end of items currently linked to the full
-- subtype and append the private items to the end. However, if Priv
-- and Full already have the same list of rep items, then the append
-- is not done, as that would create a circularity.
--
-- The partial view may have a predicate and the rep item lists of
-- both views agree when inherited from the same ancestor. In that
-- case, simply propagate the list from one view to the other.
-- A more complex analysis needed here ???
elsif Present (Priv_Item)
and then Item = Next_Rep_Item (Priv_Item)
then
Set_First_Rep_Item (Full, Priv_Item);
elsif Item /= Priv_Item then
Append := True;
loop
Next_Item := Next_Rep_Item (Item);
exit when No (Next_Item);
Item := Next_Item;
-- If the private view has aspect specifications, the full view
-- inherits them. Since these aspects may already have been
-- attached to the full view during derivation, do not append
-- them if already present.
if Item = First_Rep_Item (Priv) then
Append := False;
exit;
end if;
end loop;
-- And link the private type items at the end of the chain
if Append then
Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
end if;
end if;
end;
-- Make sure Has_Predicates is set on full type if it is set on the
-- private type. Note that it may already be set on the full type and
-- if so, we don't want to unset it. Similarly, propagate information
-- about delayed aspects, because the corresponding pragmas must be
-- analyzed when one of the views is frozen. This last step is needed
-- in particular when the full type is a scalar type for which an
-- anonymous base type is constructed.
-- The predicate functions are generated either at the freeze point
-- of the type or at the end of the visible part, and we must avoid
-- generating them twice.
Propagate_Predicate_Attributes (Full, Priv);
if Has_Delayed_Aspects (Priv) then
Set_Has_Delayed_Aspects (Full);
end if;
end Complete_Private_Subtype;
----------------------------
-- Constant_Redeclaration --
----------------------------
procedure Constant_Redeclaration
(Id : Entity_Id;
N : Node_Id;
T : out Entity_Id)
is
Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
Obj_Def : constant Node_Id := Object_Definition (N);
New_T : Entity_Id;
procedure Check_Possible_Deferred_Completion
(Prev_Id : Entity_Id;
Curr_Obj_Def : Node_Id);
-- Determine whether the two object definitions describe the partial
-- and the full view of a constrained deferred constant. Generate
-- a subtype for the full view and verify that it statically matches
-- the subtype of the partial view.
procedure Check_Recursive_Declaration (Typ : Entity_Id);
-- If deferred constant is an access type initialized with an allocator,
-- check whether there is an illegal recursion in the definition,
-- through a default value of some record subcomponent. This is normally
-- detected when generating init procs, but requires this additional
-- mechanism when expansion is disabled.
----------------------------------------
-- Check_Possible_Deferred_Completion --
----------------------------------------
procedure Check_Possible_Deferred_Completion
(Prev_Id : Entity_Id;
Curr_Obj_Def : Node_Id)
is
Curr_Typ : Entity_Id;
Prev_Typ : constant Entity_Id := Etype (Prev_Id);
Anon_Acc : constant Boolean := Is_Anonymous_Access_Type (Prev_Typ);
Mismatch : Boolean := False;
begin
if Anon_Acc then
null;
elsif Nkind (Curr_Obj_Def) = N_Subtype_Indication then
declare
Loc : constant Source_Ptr := Sloc (N);
Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
Decl : constant Node_Id :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication =>
Relocate_Node (Curr_Obj_Def));
begin
Insert_Before_And_Analyze (N, Decl);
Set_Etype (Id, Def_Id);
Curr_Typ := Def_Id;
end;
else
Curr_Typ := Etype (Curr_Obj_Def);
end if;
if Anon_Acc then
if Nkind (Curr_Obj_Def) /= N_Access_Definition then
Mismatch := True;
elsif Has_Null_Exclusion (Prev_Typ)
and then not Null_Exclusion_Present (Curr_Obj_Def)
then
Mismatch := True;
end if;
-- ??? Another check needed: mismatch if disagreement
-- between designated types/profiles .
else
Mismatch :=
Is_Constrained (Prev_Typ)
and then not Subtypes_Statically_Match (Prev_Typ, Curr_Typ);
end if;
if Mismatch then
Error_Msg_Sloc := Sloc (Prev_Id);
Error_Msg_N ("subtype does not statically match deferred "
& "declaration #", N);
end if;
end Check_Possible_Deferred_Completion;
---------------------------------
-- Check_Recursive_Declaration --
---------------------------------
procedure Check_Recursive_Declaration (Typ : Entity_Id) is
Comp : Entity_Id;
begin
if Is_Record_Type (Typ) then
Comp := First_Component (Typ);
while Present (Comp) loop
if Comes_From_Source (Comp) then
if Present (Expression (Parent (Comp)))
and then Is_Entity_Name (Expression (Parent (Comp)))
and then Entity (Expression (Parent (Comp))) = Prev
then
Error_Msg_Sloc := Sloc (Parent (Comp));
Error_Msg_NE
("illegal circularity with declaration for & #",
N, Comp);
return;
elsif Is_Record_Type (Etype (Comp)) then
Check_Recursive_Declaration (Etype (Comp));
end if;
end if;
Next_Component (Comp);
end loop;
end if;
end Check_Recursive_Declaration;
-- Start of processing for Constant_Redeclaration
begin
if Nkind (Parent (Prev)) = N_Object_Declaration then
if Nkind (Object_Definition
(Parent (Prev))) = N_Subtype_Indication
then
-- Find type of new declaration. The constraints of the two
-- views must match statically, but there is no point in
-- creating an itype for the full view.
if Nkind (Obj_Def) = N_Subtype_Indication then
Find_Type (Subtype_Mark (Obj_Def));
New_T := Entity (Subtype_Mark (Obj_Def));
else
Find_Type (Obj_Def);
New_T := Entity (Obj_Def);
end if;
T := Etype (Prev);
else
-- The full view may impose a constraint, even if the partial
-- view does not, so construct the subtype.
New_T := Find_Type_Of_Object (Obj_Def, N);
T := New_T;
end if;
else
-- Current declaration is illegal, diagnosed below in Enter_Name
T := Empty;
New_T := Any_Type;
end if;
-- If previous full declaration or a renaming declaration exists, or if
-- a homograph is present, let Enter_Name handle it, either with an
-- error or with the removal of an overridden implicit subprogram.
-- The previous one is a full declaration if it has an expression
-- (which in the case of an aggregate is indicated by the Init flag).
if Ekind (Prev) /= E_Constant
or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
or else Present (Expression (Parent (Prev)))
or else Has_Init_Expression (Parent (Prev))
or else Present (Full_View (Prev))
then
Enter_Name (Id);
-- Verify that types of both declarations match, or else that both types
-- are anonymous access types whose designated subtypes statically match
-- (as allowed in Ada 2005 by AI-385).
elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
and then
(Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
or else Is_Access_Constant (Etype (New_T)) /=
Is_Access_Constant (Etype (Prev))
or else Can_Never_Be_Null (Etype (New_T)) /=
Can_Never_Be_Null (Etype (Prev))
or else Null_Exclusion_Present (Parent (Prev)) /=
Null_Exclusion_Present (Parent (Id))
or else not Subtypes_Statically_Match
(Designated_Type (Etype (Prev)),
Designated_Type (Etype (New_T))))
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("type does not match declaration#", N);
Set_Full_View (Prev, Id);
Set_Etype (Id, Any_Type);
-- A deferred constant whose type is an anonymous array is always
-- illegal (unless imported). A detailed error message might be
-- helpful for Ada beginners.
if Nkind (Object_Definition (Parent (Prev)))
= N_Constrained_Array_Definition
and then Nkind (Object_Definition (N))
= N_Constrained_Array_Definition
then
Error_Msg_N ("\each anonymous array is a distinct type", N);
Error_Msg_N ("a deferred constant must have a named type",
Object_Definition (Parent (Prev)));
end if;
elsif
Null_Exclusion_Present (Parent (Prev))
and then not Null_Exclusion_Present (N)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("null-exclusion does not match declaration#", N);
Set_Full_View (Prev, Id);
Set_Etype (Id, Any_Type);
-- If so, process the full constant declaration
else
-- RM 7.4 (6): If the subtype defined by the subtype_indication in
-- the deferred declaration is constrained, then the subtype defined
-- by the subtype_indication in the full declaration shall match it
-- statically.
Check_Possible_Deferred_Completion
(Prev_Id => Prev,
Curr_Obj_Def => Obj_Def);
Set_Full_View (Prev, Id);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
Append_Entity (Id, Current_Scope);
-- Check ALIASED present if present before (RM 7.4(7))
if Is_Aliased (Prev)
and then not Aliased_Present (N)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("ALIASED required (see declaration #)", N);
end if;
-- Check that placement is in private part and that the incomplete
-- declaration appeared in the visible part.
if Ekind (Current_Scope) = E_Package
and then not In_Private_Part (Current_Scope)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N
("full constant for declaration # must be in private part", N);
elsif Ekind (Current_Scope) = E_Package
and then
List_Containing (Parent (Prev)) /=
Visible_Declarations (Package_Specification (Current_Scope))
then
Error_Msg_N
("deferred constant must be declared in visible part",
Parent (Prev));
end if;
if Is_Access_Type (T)
and then Nkind (Expression (N)) = N_Allocator
then
Check_Recursive_Declaration (Designated_Type (T));
end if;
-- A deferred constant is a visible entity. If type has invariants,
-- verify that the initial value satisfies them. This is not done in
-- GNATprove mode, as GNATprove handles invariant checks itself.
if Has_Invariants (T)
and then Present (Invariant_Procedure (T))
and then not GNATprove_Mode
then
Insert_After (N,
Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N))));
end if;
end if;
end Constant_Redeclaration;
----------------------
-- Constrain_Access --
----------------------
procedure Constrain_Access
(Def_Id : in out Entity_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
Desig_Type : constant Entity_Id := Designated_Type (T);
Desig_Subtype : Entity_Id;
Constraint_OK : Boolean := True;
begin
if Is_Array_Type (Desig_Type) then
Desig_Subtype := Create_Itype (E_Void, Related_Nod);
Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
elsif (Is_Record_Type (Desig_Type)
or else Is_Incomplete_Or_Private_Type (Desig_Type))
and then not Is_Constrained (Desig_Type)
then
-- If this is a constrained access definition for a record
-- component, we leave the type as an unconstrained access,
-- and mark the component so that its actual type is built
-- at a point of use (e.g., an assignment statement). This
-- is handled in Sem_Util.Build_Actual_Subtype_Of_Component.
if Desig_Type = Current_Scope
and then No (Def_Id)
then
Desig_Subtype :=
Create_Itype
(E_Void, Related_Nod, Scope_Id => Scope (Desig_Type));
Mutate_Ekind (Desig_Subtype, E_Record_Subtype);
Def_Id := Entity (Subtype_Mark (S));
-- We indicate that the component has a per-object constraint
-- for treatment at a point of use, even though the constraint
-- may be independent of discriminants of the enclosing type.
if Nkind (Related_Nod) = N_Component_Declaration then
Set_Has_Per_Object_Constraint
(Defining_Identifier (Related_Nod));
end if;
-- This call added to ensure that the constraint is analyzed
-- (needed for a B test). Note that we still return early from
-- this procedure to avoid recursive processing.
Constrain_Discriminated_Type
(Desig_Subtype, S, Related_Nod, For_Access => True);
return;
end if;
-- Enforce rule that the constraint is illegal if there is an
-- unconstrained view of the designated type. This means that the
-- partial view (either a private type declaration or a derivation
-- from a private type) has no discriminants. (Defect Report
-- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
-- Rule updated for Ada 2005: The private type is said to have
-- a constrained partial view, given that objects of the type
-- can be declared. Furthermore, the rule applies to all access
-- types, unlike the rule concerning default discriminants (see
-- RM 3.7.1(7/3))
if (Ekind (T) = E_General_Access_Type or else Ada_Version >= Ada_2005)
and then Has_Private_Declaration (Desig_Type)
and then In_Open_Scopes (Scope (Desig_Type))
and then Has_Discriminants (Desig_Type)
then
declare
Pack : constant Node_Id :=
Unit_Declaration_Node (Scope (Desig_Type));
Decls : List_Id;
Decl : Node_Id;
begin
if Nkind (Pack) = N_Package_Declaration then
Decls := Visible_Declarations (Specification (Pack));
Decl := First (Decls);
while Present (Decl) loop
if (Nkind (Decl) = N_Private_Type_Declaration
and then Chars (Defining_Identifier (Decl)) =
Chars (Desig_Type))
or else
(Nkind (Decl) = N_Full_Type_Declaration
and then
Chars (Defining_Identifier (Decl)) =
Chars (Desig_Type)
and then Is_Derived_Type (Desig_Type)
and then
Has_Private_Declaration (Etype (Desig_Type)))
then
if No (Discriminant_Specifications (Decl)) then
Error_Msg_N
("cannot constrain access type if designated "
& "type has constrained partial view", S);
end if;
exit;
end if;
Next (Decl);
end loop;
end if;
end;
end if;
Desig_Subtype := Create_Itype (E_Void, Related_Nod);
Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
For_Access => True);
elsif Is_Concurrent_Type (Desig_Type)
and then not Is_Constrained (Desig_Type)
then
Desig_Subtype := Create_Itype (E_Void, Related_Nod);
Constrain_Concurrent (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
else
Error_Msg_N ("invalid constraint on access type", S);
-- We simply ignore an invalid constraint
Desig_Subtype := Desig_Type;
Constraint_OK := False;
end if;
if No (Def_Id) then
Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
else
Mutate_Ekind (Def_Id, E_Access_Subtype);
end if;
if Constraint_OK then
Set_Etype (Def_Id, Base_Type (T));
if Is_Private_Type (Desig_Type) then
Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
end if;
else
Set_Etype (Def_Id, Any_Type);
end if;
Set_Size_Info (Def_Id, T);
Set_Is_Constrained (Def_Id, Constraint_OK);
Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
Set_Can_Never_Be_Null (Def_Id, Can_Never_Be_Null (T));
Conditional_Delay (Def_Id, T);
-- AI-363 : Subtypes of general access types whose designated types have
-- default discriminants are disallowed. In instances, the rule has to
-- be checked against the actual, of which T is the subtype. In a
-- generic body, the rule is checked assuming that the actual type has
-- defaulted discriminants.
if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
if Ekind (Base_Type (T)) = E_General_Access_Type
and then Has_Defaulted_Discriminants (Desig_Type)
then
if Ada_Version < Ada_2005 then
Error_Msg_N
("access subtype of general access type would not " &
"be allowed in Ada 2005?y?", S);
else
Error_Msg_N
("access subtype of general access type not allowed", S);
end if;
Error_Msg_N ("\discriminants have defaults", S);
elsif Is_Access_Type (T)
and then Is_Generic_Type (Desig_Type)
and then Has_Discriminants (Desig_Type)
and then In_Package_Body (Current_Scope)
then
if Ada_Version < Ada_2005 then
Error_Msg_N
("access subtype would not be allowed in generic body "
& "in Ada 2005?y?", S);
else
Error_Msg_N
("access subtype not allowed in generic body", S);
end if;
Error_Msg_N
("\designated type is a discriminated formal", S);
end if;
end if;
end Constrain_Access;
---------------------
-- Constrain_Array --
---------------------
procedure Constrain_Array
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
C : constant Node_Id := Constraint (SI);
Number_Of_Constraints : Nat := 0;
Index : Node_Id;
S, T : Entity_Id;
Constraint_OK : Boolean := True;
Is_FLB_Array_Subtype : Boolean := False;
begin
T := Entity (Subtype_Mark (SI));
if Is_Access_Type (T) then
T := Designated_Type (T);
end if;
T := Underlying_Type (T);
-- If an index constraint follows a subtype mark in a subtype indication
-- then the type or subtype denoted by the subtype mark must not already
-- impose an index constraint. The subtype mark must denote either an
-- unconstrained array type or an access type whose designated type
-- is such an array type... (RM 3.6.1)
if Is_Constrained (T) then
Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
Constraint_OK := False;
else
S := First (Constraints (C));
while Present (S) loop
Number_Of_Constraints := Number_Of_Constraints + 1;
Next (S);
end loop;
-- In either case, the index constraint must provide a discrete
-- range for each index of the array type and the type of each
-- discrete range must be the same as that of the corresponding
-- index. (RM 3.6.1)
if Number_Of_Constraints /= Number_Dimensions (T) then
Error_Msg_NE ("incorrect number of index constraints for }", C, T);
Constraint_OK := False;
else
S := First (Constraints (C));
Index := First_Index (T);
Analyze (Index);
-- Apply constraints to each index type
for J in 1 .. Number_Of_Constraints loop
Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
-- If the subtype of the index has been set to indicate that
-- it has a fixed lower bound, then record that the subtype's
-- entity will need to be marked as being a fixed-lower-bound
-- array subtype.
if S = First (Constraints (C)) then
Is_FLB_Array_Subtype :=
Is_Fixed_Lower_Bound_Index_Subtype (Etype (S));
-- If the parent subtype (or should this be Etype of that?)
-- is an FLB array subtype, we flag an error, because we
-- don't currently allow subtypes of such subtypes to
-- specify a fixed lower bound for any of their indexes,
-- even if the index of the parent subtype is a "range <>"
-- index.
if Is_FLB_Array_Subtype
and then Is_Fixed_Lower_Bound_Array_Subtype (T)
then
Error_Msg_NE
("index with fixed lower bound not allowed for subtype "
& "of fixed-lower-bound }", S, T);
Is_FLB_Array_Subtype := False;
end if;
elsif Is_FLB_Array_Subtype
and then not Is_Fixed_Lower_Bound_Index_Subtype (Etype (S))
then
Error_Msg_NE
("constrained index not allowed for fixed-lower-bound "
& "subtype of}", S, T);
elsif not Is_FLB_Array_Subtype
and then Is_Fixed_Lower_Bound_Index_Subtype (Etype (S))
then
Error_Msg_NE
("index with fixed lower bound not allowed for "
& "constrained subtype of}", S, T);
end if;
Next (Index);
Next (S);
end loop;
end if;
end if;
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
Set_Parent (Def_Id, Related_Nod);
else
Mutate_Ekind (Def_Id, E_Array_Subtype);
end if;
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Etype (Def_Id, Base_Type (T));
if Constraint_OK then
Set_First_Index (Def_Id, First (Constraints (C)));
else
Set_First_Index (Def_Id, First_Index (T));
end if;
Set_Is_Constrained (Def_Id, not Is_FLB_Array_Subtype);
Set_Is_Fixed_Lower_Bound_Array_Subtype
(Def_Id, Is_FLB_Array_Subtype);
Set_Is_Aliased (Def_Id, Is_Aliased (T));
Set_Is_Independent (Def_Id, Is_Independent (T));
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
-- A subtype does not inherit the Packed_Array_Impl_Type of is parent.
-- We need to initialize the attribute because if Def_Id is previously
-- analyzed through a limited_with clause, it will have the attributes
-- of an incomplete type, one of which is an Elist that overlaps the
-- Packed_Array_Impl_Type field.
Set_Packed_Array_Impl_Type (Def_Id, Empty);
-- Build a freeze node if parent still needs one. Also make sure that
-- the Depends_On_Private status is set because the subtype will need
-- reprocessing at the time the base type does, and also we must set a
-- conditional delay.
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
Conditional_Delay (Def_Id, T);
end Constrain_Array;
------------------------------
-- Constrain_Component_Type --
------------------------------
function Constrain_Component_Type
(Comp : Entity_Id;
Constrained_Typ : Entity_Id;
Related_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (Constrained_Typ);
Compon_Type : constant Entity_Id := Etype (Comp);
function Build_Constrained_Array_Type
(Old_Type : Entity_Id) return Entity_Id;
-- If Old_Type is an array type, one of whose indexes is constrained
-- by a discriminant, build an Itype whose constraint replaces the
-- discriminant with its value in the constraint.
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id) return Entity_Id;
-- Ditto for record components. Handle the case where the constraint
-- is a conversion of the discriminant value, introduced during
-- expansion.
function Build_Constrained_Access_Type
(Old_Type : Entity_Id) return Entity_Id;
-- Ditto for access types. Makes use of previous two functions, to
-- constrain designated type.
function Is_Discriminant (Expr : Node_Id) return Boolean;
-- Returns True if Expr is a discriminant
function Get_Discr_Value (Discr_Expr : Node_Id) return Node_Id;
-- Find the value of a discriminant named by Discr_Expr in Constraints
-----------------------------------
-- Build_Constrained_Access_Type --
-----------------------------------
function Build_Constrained_Access_Type
(Old_Type : Entity_Id) return Entity_Id
is
Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
Itype : Entity_Id;
Desig_Subtype : Entity_Id;
Scop : Entity_Id;
begin
-- If the original access type was not embedded in the enclosing
-- type definition, there is no need to produce a new access
-- subtype. In fact every access type with an explicit constraint
-- generates an itype whose scope is the enclosing record.
if not Is_Type (Scope (Old_Type)) then
return Old_Type;
elsif Is_Array_Type (Desig_Type) then
Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
elsif Has_Discriminants (Desig_Type) then
-- This may be an access type to an enclosing record type for
-- which we are constructing the constrained components. Return
-- the enclosing record subtype. This is not always correct,
-- but avoids infinite recursion. ???
Desig_Subtype := Any_Type;
for J in reverse 0 .. Scope_Stack.Last loop
Scop := Scope_Stack.Table (J).Entity;
if Is_Type (Scop)
and then Base_Type (Scop) = Base_Type (Desig_Type)
then
Desig_Subtype := Scop;
end if;
exit when not Is_Type (Scop);
end loop;
if Desig_Subtype = Any_Type then
Desig_Subtype :=
Build_Constrained_Discriminated_Type (Desig_Type);
end if;
else
return Old_Type;
end if;
if Desig_Subtype /= Desig_Type then
-- The Related_Node better be here or else we won't be able
-- to attach new itypes to a node in the tree.
pragma Assert (Present (Related_Node));
Itype := Create_Itype (E_Access_Subtype, Related_Node);
Set_Etype (Itype, Base_Type (Old_Type));
Set_Size_Info (Itype, (Old_Type));
Set_Directly_Designated_Type (Itype, Desig_Subtype);
Set_Depends_On_Private (Itype, Has_Private_Component
(Old_Type));
Set_Is_Access_Constant (Itype, Is_Access_Constant
(Old_Type));
-- The new itype needs freezing when it depends on a not frozen
-- type and the enclosing subtype needs freezing.
if Has_Delayed_Freeze (Constrained_Typ)
and then not Is_Frozen (Constrained_Typ)
then
Conditional_Delay (Itype, Base_Type (Old_Type));
end if;
return Itype;
else
return Old_Type;
end if;
end Build_Constrained_Access_Type;
----------------------------------
-- Build_Constrained_Array_Type --
----------------------------------
function Build_Constrained_Array_Type
(Old_Type : Entity_Id) return Entity_Id
is
Lo_Expr : Node_Id;
Hi_Expr : Node_Id;
Old_Index : Node_Id;
Range_Node : Node_Id;
Constr_List : List_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr)
or else
Is_Discriminant (Hi_Expr)
then
Need_To_Create_Itype := True;
exit;
end if;
Next_Index (Old_Index);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr) then
Lo_Expr := Get_Discr_Value (Lo_Expr);
end if;
if Is_Discriminant (Hi_Expr) then
Hi_Expr := Get_Discr_Value (Hi_Expr);
end if;
Range_Node :=
Make_Range
(Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
Append (Range_Node, To => Constr_List);
Next_Index (Old_Index);
end loop;
return Build_Subtype (Related_Node, Loc, Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Array_Type;
------------------------------------------
-- Build_Constrained_Discriminated_Type --
------------------------------------------
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id) return Entity_Id
is
Expr : Node_Id;
Constr_List : List_Id;
Old_Constraint : Elmt_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Need_To_Create_Itype := True;
exit;
-- After expansion of discriminated task types, the value
-- of the discriminant may be converted to a run-time type
-- for restricted run-times. Propagate the value of the
-- discriminant as well, so that e.g. the secondary stack
-- component has a static constraint. Necessary for LLVM.
elsif Nkind (Expr) = N_Type_Conversion
and then Is_Discriminant (Expression (Expr))
then
Need_To_Create_Itype := True;
exit;
end if;
Next_Elmt (Old_Constraint);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Expr := Get_Discr_Value (Expr);
elsif Nkind (Expr) = N_Type_Conversion
and then Is_Discriminant (Expression (Expr))
then
Expr := New_Copy_Tree (Expr);
Set_Expression (Expr, Get_Discr_Value (Expression (Expr)));
end if;
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (Old_Constraint);
end loop;
return Build_Subtype (Related_Node, Loc, Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Discriminated_Type;
---------------------
-- Get_Discr_Value --
---------------------
function Get_Discr_Value (Discr_Expr : Node_Id) return Node_Id is
Discr_Id : constant Entity_Id := Entity (Discr_Expr);
-- Entity of a discriminant that appear as a standalone expression in
-- the constraint of a component.
D : Entity_Id;
E : Elmt_Id;
begin
-- The discriminant may be declared for the type, in which case we
-- find it by iterating over the list of discriminants. If the
-- discriminant is inherited from a parent type, it appears as the
-- corresponding discriminant of the current type. This will be the
-- case when constraining an inherited component whose constraint is
-- given by a discriminant of the parent.
D := First_Discriminant (Typ);
E := First_Elmt (Constraints);
while Present (D) loop
if D = Discr_Id
or else D = CR_Discriminant (Discr_Id)
or else Corresponding_Discriminant (D) = Discr_Id
then
return New_Copy_Tree (Node (E));
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
-- The Corresponding_Discriminant mechanism is incomplete, because
-- the correspondence between new and old discriminants is not one
-- to one: one new discriminant can constrain several old ones. In
-- that case, scan sequentially the stored_constraint, the list of
-- discriminants of the parents, and the constraints.
-- Previous code checked for the present of the Stored_Constraint
-- list for the derived type, but did not use it at all. Should it
-- be present when the component is a discriminated task type?
if Is_Derived_Type (Typ)
and then Scope (Discr_Id) = Etype (Typ)
then
D := First_Discriminant (Etype (Typ));
E := First_Elmt (Constraints);
while Present (D) loop
if D = Discr_Id then
return New_Copy_Tree (Node (E));
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end if;
-- Something is wrong if we did not find the value
raise Program_Error;
end Get_Discr_Value;
---------------------
-- Is_Discriminant --
---------------------
function Is_Discriminant (Expr : Node_Id) return Boolean is
Discrim_Scope : Entity_Id;
begin
if Denotes_Discriminant (Expr) then
Discrim_Scope := Scope (Entity (Expr));
-- Either we have a reference to one of Typ's discriminants,
pragma Assert (Discrim_Scope = Typ
-- or to the discriminants of the parent type, in the case
-- of a derivation of a tagged type with variants.
or else Discrim_Scope = Etype (Typ)
or else Full_View (Discrim_Scope) = Etype (Typ)
-- or same as above for the case where the discriminants
-- were declared in Typ's private view.
or else (Is_Private_Type (Discrim_Scope)
and then Chars (Discrim_Scope) = Chars (Typ))
-- or else we are deriving from the full view and the
-- discriminant is declared in the private entity.
or else (Is_Private_Type (Typ)
and then Chars (Discrim_Scope) = Chars (Typ))
-- Or we are constrained the corresponding record of a
-- synchronized type that completes a private declaration.
or else (Is_Concurrent_Record_Type (Typ)
and then
Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
-- or we have a class-wide type, in which case make sure the
-- discriminant found belongs to the root type.
or else (Is_Class_Wide_Type (Typ)
and then Etype (Typ) = Discrim_Scope));
return True;
end if;
-- In all other cases we have something wrong
return False;
end Is_Discriminant;
-- Start of processing for Constrain_Component_Type
begin
if Nkind (Parent (Comp)) = N_Component_Declaration
and then Comes_From_Source (Parent (Comp))
and then Comes_From_Source
(Subtype_Indication (Component_Definition (Parent (Comp))))
and then
Is_Entity_Name
(Subtype_Indication (Component_Definition (Parent (Comp))))
then
return Compon_Type;
elsif Is_Array_Type (Compon_Type) then
return Build_Constrained_Array_Type (Compon_Type);
elsif Has_Discriminants (Compon_Type) then
return Build_Constrained_Discriminated_Type (Compon_Type);
elsif Is_Access_Type (Compon_Type) then
return Build_Constrained_Access_Type (Compon_Type);
else
return Compon_Type;
end if;
end Constrain_Component_Type;
--------------------------
-- Constrain_Concurrent --
--------------------------
-- For concurrent types, the associated record value type carries the same
-- discriminants, so when we constrain a concurrent type, we must constrain
-- the corresponding record type as well.
procedure Constrain_Concurrent
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
-- Retrieve Base_Type to ensure getting to the concurrent type in the
-- case of a private subtype (needed when only doing semantic analysis).
T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI)));
T_Val : Entity_Id;
begin
if Is_Access_Type (T_Ent) then
T_Ent := Designated_Type (T_Ent);
end if;
T_Val := Corresponding_Record_Type (T_Ent);
if Present (T_Val) then
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
-- Elaborate itype now, as it may be used in a subsequent
-- synchronized operation in another scope.
if Nkind (Related_Nod) = N_Full_Type_Declaration then
Build_Itype_Reference (Def_Id, Related_Nod);
end if;
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
Set_First_Private_Entity (Def_Id, First_Private_Entity (T_Ent));
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Corresponding_Record_Type (Def_Id,
Constrain_Corresponding_Record (Def_Id, T_Val, Related_Nod));
else
-- If there is no associated record, expansion is disabled and this
-- is a generic context. Create a subtype in any case, so that
-- semantic analysis can proceed.
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
end if;
end Constrain_Concurrent;
------------------------------------
-- Constrain_Corresponding_Record --
------------------------------------
function Constrain_Corresponding_Record
(Prot_Subt : Entity_Id;
Corr_Rec : Entity_Id;
Related_Nod : Node_Id) return Entity_Id
is
T_Sub : constant Entity_Id :=
Create_Itype
(Ekind => E_Record_Subtype,
Related_Nod => Related_Nod,
Related_Id => Corr_Rec,
Suffix => 'C',
Suffix_Index => -1);
begin
Set_Etype (T_Sub, Corr_Rec);
Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
Set_Is_Tagged_Type (T_Sub, Is_Tagged_Type (Corr_Rec));
Set_Is_Constrained (T_Sub, True);
Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
if Has_Discriminants (Prot_Subt) then -- False only if errors.
Set_Discriminant_Constraint
(T_Sub, Discriminant_Constraint (Prot_Subt));
Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
Create_Constrained_Components
(T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
end if;
Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
Conditional_Delay (T_Sub, Corr_Rec);
else
-- This is a component subtype: it will be frozen in the context of
-- the enclosing record's init_proc, so that discriminant references
-- are resolved to discriminals. (Note: we used to skip freezing
-- altogether in that case, which caused errors downstream for
-- components of a bit packed array type).
Set_Has_Delayed_Freeze (T_Sub);
end if;
return T_Sub;
end Constrain_Corresponding_Record;
-----------------------
-- Constrain_Decimal --
-----------------------
procedure Constrain_Decimal (Def_Id : Entity_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
Loc : constant Source_Ptr := Sloc (C);
Range_Expr : Node_Id;
Digits_Expr : Node_Id;
Digits_Val : Uint;
Bound_Val : Ureal;
begin
Mutate_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
if Nkind (C) = N_Range_Constraint then
Range_Expr := Range_Expression (C);
Digits_Val := Digits_Value (T);
else
pragma Assert (Nkind (C) = N_Digits_Constraint);
Digits_Expr := Digits_Expression (C);
Analyze_And_Resolve (Digits_Expr, Any_Integer);
Check_Digits_Expression (Digits_Expr);
Digits_Val := Expr_Value (Digits_Expr);
if Digits_Val > Digits_Value (T) then
Error_Msg_N
("digits expression is incompatible with subtype", C);
Digits_Val := Digits_Value (T);
end if;
if Present (Range_Constraint (C)) then
Range_Expr := Range_Expression (Range_Constraint (C));
else
Range_Expr := Empty;
end if;
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Delta_Value (Def_Id, Delta_Value (T));
Set_Scale_Value (Def_Id, Scale_Value (T));
Set_Small_Value (Def_Id, Small_Value (T));
Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
Set_Digits_Value (Def_Id, Digits_Val);
-- Manufacture range from given digits value if no range present
if No (Range_Expr) then
Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
Range_Expr :=
Make_Range (Loc,
Low_Bound =>
Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
High_Bound =>
Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
end if;
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Decimal;
----------------------------------
-- Constrain_Discriminated_Type --
----------------------------------
procedure Constrain_Discriminated_Type
(Def_Id : Entity_Id;
S : Node_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
E : Entity_Id := Entity (Subtype_Mark (S));
T : Entity_Id;
procedure Fixup_Bad_Constraint;
-- Called after finding a bad constraint, and after having posted an
-- appropriate error message. The goal is to leave type Def_Id in as
-- reasonable state as possible.
--------------------------
-- Fixup_Bad_Constraint --
--------------------------
procedure Fixup_Bad_Constraint is
begin
-- Set a reasonable Ekind for the entity, including incomplete types.
Mutate_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
-- Set Etype to the known type, to reduce chances of cascaded errors
Set_Etype (Def_Id, E);
Set_Error_Posted (Def_Id);
end Fixup_Bad_Constraint;
-- Local variables
C : Node_Id;
Constr : Elist_Id := New_Elmt_List;
-- Start of processing for Constrain_Discriminated_Type
begin
C := Constraint (S);
-- A discriminant constraint is only allowed in a subtype indication,
-- after a subtype mark. This subtype mark must denote either a type
-- with discriminants, or an access type whose designated type is a
-- type with discriminants. A discriminant constraint specifies the
-- values of these discriminants (RM 3.7.2(5)).
T := Base_Type (Entity (Subtype_Mark (S)));
if Is_Access_Type (T) then
T := Designated_Type (T);
end if;
-- In an instance it may be necessary to retrieve the full view of a
-- type with unknown discriminants, or a full view with defaulted
-- discriminants. In other contexts the constraint is illegal.
if In_Instance
and then Is_Private_Type (T)
and then Present (Full_View (T))
and then
(Has_Unknown_Discriminants (T)
or else
(not Has_Discriminants (T)
and then Has_Defaulted_Discriminants (Full_View (T))))
then
T := Full_View (T);
E := Full_View (E);
end if;
-- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal. Avoid
-- generating an error for access-to-incomplete subtypes.
if Ada_Version >= Ada_2005
and then Ekind (T) = E_Incomplete_Type
and then Nkind (Parent (S)) = N_Subtype_Declaration
and then not Is_Itype (Def_Id)
then
-- A little sanity check: emit an error message if the type has
-- discriminants to begin with. Type T may be a regular incomplete
-- type or imported via a limited with clause.
if Has_Discriminants (T)
or else (From_Limited_With (T)
and then Present (Non_Limited_View (T))
and then Nkind (Parent (Non_Limited_View (T))) =
N_Full_Type_Declaration
and then Present (Discriminant_Specifications
(Parent (Non_Limited_View (T)))))
then
Error_Msg_N
("(Ada 2005) incomplete subtype may not be constrained", C);
else
Error_Msg_N ("invalid constraint: type has no discriminant", C);
end if;
Fixup_Bad_Constraint;
return;
-- Check that the type has visible discriminants. The type may be
-- a private type with unknown discriminants whose full view has
-- discriminants which are invisible.
elsif not Has_Discriminants (T)
or else
(Has_Unknown_Discriminants (T)
and then Is_Private_Type (T))
then
Error_Msg_N ("invalid constraint: type has no discriminant", C);
Fixup_Bad_Constraint;
return;
elsif Is_Constrained (E)
or else (Ekind (E) = E_Class_Wide_Subtype
and then Present (Discriminant_Constraint (E)))
then
Error_Msg_N ("type is already constrained", Subtype_Mark (S));
Fixup_Bad_Constraint;
return;
end if;
-- T may be an unconstrained subtype (e.g. a generic actual). Constraint
-- applies to the base type.
T := Base_Type (T);
Constr := Build_Discriminant_Constraints (T, S);
-- If the list returned was empty we had an error in building the
-- discriminant constraint. We have also already signalled an error
-- in the incomplete type case
if Is_Empty_Elmt_List (Constr) then
Fixup_Bad_Constraint;
return;
end if;
Build_Discriminated_Subtype (T, Def_Id, Constr, Related_Nod, For_Access);
end Constrain_Discriminated_Type;
---------------------------
-- Constrain_Enumeration --
---------------------------
procedure Constrain_Enumeration (Def_Id : Entity_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Mutate_Ekind (Def_Id, E_Enumeration_Subtype);
Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
-- Inherit the chain of representation items instead of replacing it
-- because Build_Derived_Enumeration_Type rewrites the declaration of
-- the derived type as a subtype declaration and the former needs to
-- preserve existing representation items (see Build_Derived_Type).
Inherit_Rep_Item_Chain (Def_Id, T);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Enumeration;
----------------------
-- Constrain_Float --
----------------------
procedure Constrain_Float (Def_Id : Entity_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Mutate_Ekind (Def_Id, E_Floating_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
-- Process the constraint
C := Constraint (S);
-- Digits constraint present
if Nkind (C) = N_Digits_Constraint then
Check_Restriction (No_Obsolescent_Features, C);
if Warn_On_Obsolescent_Feature then
Error_Msg_N
("subtype digits constraint is an " &
"obsolescent feature (RM J.3(8))?j?", C);
end if;
D := Digits_Expression (C);
Analyze_And_Resolve (D, Any_Integer);
Check_Digits_Expression (D);
Set_Digits_Value (Def_Id, Expr_Value (D));
-- Check that digits value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this.
if Digits_Value (Def_Id) > Digits_Value (T) then
Error_Msg_Uint_1 := Digits_Value (T);
Error_Msg_N ("??digits value is too large, maximum is ^", D);
Rais :=
Make_Raise_Constraint_Error (Sloc (D),
Reason => CE_Range_Check_Failed);
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No digits constraint present
else
Set_Digits_Value (Def_Id, Digits_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Is_Constrained (Def_Id);
end Constrain_Float;
---------------------
-- Constrain_Index --
---------------------
procedure Constrain_Index
(Index : Node_Id;
S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character;
Suffix_Index : Pos)
is
Def_Id : Entity_Id;
R : Node_Id := Empty;
T : constant Entity_Id := Etype (Index);
Is_FLB_Index : Boolean := False;
begin
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Nkind (S) = N_Range
or else
(Nkind (S) = N_Attribute_Reference
and then Attribute_Name (S) = Name_Range)
then
-- A Range attribute will be transformed into N_Range by Resolve
-- If a range has an Empty upper bound, then remember that for later
-- setting of the index subtype's Is_Fixed_Lower_Bound_Index_Subtype
-- flag, and also set the upper bound of the range to the index
-- subtype's upper bound rather than leaving it Empty. In truth,
-- that upper bound corresponds to a box ("<>"), but it's convenient
-- to set it to the upper bound to avoid needing to add special tests
-- in various places for an Empty upper bound, and in any case it
-- accurately characterizes the index's range of values.
if Nkind (S) = N_Range and then No (High_Bound (S)) then
Is_FLB_Index := True;
Set_High_Bound (S, Type_High_Bound (T));
end if;
R := S;
Process_Range_Expr_In_Decl (R, T);
if not Error_Posted (S)
and then
(Nkind (S) /= N_Range
or else not Covers (T, (Etype (Low_Bound (S))))
or else not Covers (T, (Etype (High_Bound (S)))))
then
if Base_Type (T) /= Any_Type
and then Etype (Low_Bound (S)) /= Any_Type
and then Etype (High_Bound (S)) /= Any_Type
then
Error_Msg_N ("range expected", S);
end if;
end if;
elsif Nkind (S) = N_Subtype_Indication then
-- The parser has verified that this is a discrete indication
Resolve_Discrete_Subtype_Indication (S, T);
Bad_Predicated_Subtype_Use
("subtype& has predicate, not allowed in index constraint",
S, Entity (Subtype_Mark (S)));
R := Range_Expression (Constraint (S));
-- Capture values of bounds and generate temporaries for them if
-- needed, since checks may cause duplication of the expressions
-- which must not be reevaluated.
-- The forced evaluation removes side effects from expressions, which
-- should occur also in GNATprove mode. Otherwise, we end up with
-- unexpected insertions of actions at places where this is not
-- supposed to occur, e.g. on default parameters of a call.
if Expander_Active or GNATprove_Mode then
Force_Evaluation
(Low_Bound (R), Related_Id => Def_Id, Is_Low_Bound => True);
Force_Evaluation
(High_Bound (R), Related_Id => Def_Id, Is_High_Bound => True);
end if;
elsif Nkind (S) = N_Discriminant_Association then
-- Syntactically valid in subtype indication
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
-- Subtype_Mark case, no anonymous subtypes to construct
else
Analyze (S);
if Is_Entity_Name (S) then
if not Is_Type (Entity (S)) then
Error_Msg_N ("expect subtype mark for index constraint", S);
elsif Base_Type (Entity (S)) /= Base_Type (T) then
Wrong_Type (S, Base_Type (T));
-- Check error of subtype with predicate in index constraint
else
Bad_Predicated_Subtype_Use
("subtype& has predicate, not allowed in index constraint",
S, Entity (S));
end if;
return;
else
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
end if;
end if;
-- Complete construction of the Itype
if Is_Modular_Integer_Type (T) then
Mutate_Ekind (Def_Id, E_Modular_Integer_Subtype);
elsif Is_Integer_Type (T) then
Mutate_Ekind (Def_Id, E_Signed_Integer_Subtype);
else
Mutate_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_First_Literal (Def_Id, First_Literal (T));
end if;
Set_Size_Info (Def_Id, (T));
Copy_RM_Size (To => Def_Id, From => T);
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
-- If this is a range for a fixed-lower-bound subtype, then set the
-- index itype's low bound to the FLB and the index itype's upper bound
-- to the high bound of the parent array type's index subtype. Also,
-- mark the itype as an FLB index subtype.
if Nkind (S) = N_Range and then Is_FLB_Index then
Set_Scalar_Range
(Def_Id,
Make_Range (Sloc (S),
Low_Bound => Low_Bound (S),
High_Bound => Type_High_Bound (T)));
Set_Is_Fixed_Lower_Bound_Index_Subtype (Def_Id);
else
Set_Scalar_Range (Def_Id, R);
end if;
Set_Etype (S, Def_Id);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Index;
-----------------------
-- Constrain_Integer --
-----------------------
procedure Constrain_Integer (Def_Id : Entity_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
if Is_Modular_Integer_Type (T) then
Mutate_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Mutate_Ekind (Def_Id, E_Signed_Integer_Subtype);
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Discrete_RM_Size (Def_Id);
end Constrain_Integer;
------------------------------
-- Constrain_Ordinary_Fixed --
------------------------------
procedure Constrain_Ordinary_Fixed (Def_Id : Entity_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Mutate_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Small_Value (Def_Id, Small_Value (T));
-- Process the constraint
C := Constraint (S);
-- Delta constraint present
if Nkind (C) = N_Delta_Constraint then
Check_Restriction (No_Obsolescent_Features, C);
if Warn_On_Obsolescent_Feature then
Error_Msg_S
("subtype delta constraint is an " &
"obsolescent feature (RM J.3(7))?j?");
end if;
D := Delta_Expression (C);
Analyze_And_Resolve (D, Any_Real);
Check_Delta_Expression (D);
Set_Delta_Value (Def_Id, Expr_Value_R (D));
-- Check that delta value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this.
if Delta_Value (Def_Id) < Delta_Value (T) then
Error_Msg_N ("??delta value is too small", D);
Rais :=
Make_Raise_Constraint_Error (Sloc (D),
Reason => CE_Range_Check_Failed);
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No delta constraint present
else
Set_Delta_Value (Def_Id, Delta_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Ordinary_Fixed;
-----------------------
-- Contain_Interface --
-----------------------
function Contain_Interface
(Iface : Entity_Id;
Ifaces : Elist_Id) return Boolean
is
Iface_Elmt : Elmt_Id;
begin
if Present (Ifaces) then
Iface_Elmt := First_Elmt (Ifaces);
while Present (Iface_Elmt) loop
if Node (Iface_Elmt) = Iface then
return True;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
return False;
end Contain_Interface;
---------------------------
-- Convert_Scalar_Bounds --
---------------------------
procedure Convert_Scalar_Bounds
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Loc : Source_Ptr)
is
Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
Lo : Node_Id;
Hi : Node_Id;
Rng : Node_Id;
begin
-- Defend against previous errors
if No (Scalar_Range (Derived_Type)) then
Check_Error_Detected;
return;
end if;
Lo := Build_Scalar_Bound
(Type_Low_Bound (Derived_Type),
Parent_Type, Implicit_Base);
Hi := Build_Scalar_Bound
(Type_High_Bound (Derived_Type),
Parent_Type, Implicit_Base);
Rng :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
Set_Parent (Rng, N);
Set_Scalar_Range (Derived_Type, Rng);
-- Analyze the bounds
Analyze_And_Resolve (Lo, Implicit_Base);
Analyze_And_Resolve (Hi, Implicit_Base);
-- Analyze the range itself, except that we do not analyze it if
-- the bounds are real literals, and we have a fixed-point type.
-- The reason for this is that we delay setting the bounds in this
-- case till we know the final Small and Size values (see circuit
-- in Freeze.Freeze_Fixed_Point_Type for further details).
if Is_Fixed_Point_Type (Parent_Type)
and then Nkind (Lo) = N_Real_Literal
and then Nkind (Hi) = N_Real_Literal
then
return;
-- Here we do the analysis of the range
-- Note: we do this manually, since if we do a normal Analyze and
-- Resolve call, there are problems with the conversions used for
-- the derived type range.
else
Set_Etype (Rng, Implicit_Base);
Set_Analyzed (Rng, True);
end if;
end Convert_Scalar_Bounds;
-------------------
-- Copy_And_Swap --
-------------------
procedure Copy_And_Swap (Priv, Full : Entity_Id) is
begin
-- Initialize new full declaration entity by copying the pertinent
-- fields of the corresponding private declaration entity.
-- We temporarily set Ekind to a value appropriate for a type to
-- avoid assert failures in Einfo from checking for setting type
-- attributes on something that is not a type. Ekind (Priv) is an
-- appropriate choice, since it allowed the attributes to be set
-- in the first place. This Ekind value will be modified later.
Mutate_Ekind (Full, Ekind (Priv));
-- Also set Etype temporarily to Any_Type, again, in the absence
-- of errors, it will be properly reset, and if there are errors,
-- then we want a value of Any_Type to remain.
Set_Etype (Full, Any_Type);
-- Now start copying attributes
Set_Has_Discriminants (Full, Has_Discriminants (Priv));
if Has_Discriminants (Full) then
Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
Set_Stored_Constraint (Full, Stored_Constraint (Priv));
end if;
Set_First_Rep_Item (Full, First_Rep_Item (Priv));
Set_Homonym (Full, Homonym (Priv));
Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
Set_Is_Public (Full, Is_Public (Priv));
Set_Is_Pure (Full, Is_Pure (Priv));
Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
Set_Has_Pragma_Unreferenced_Objects
(Full, Has_Pragma_Unreferenced_Objects
(Priv));
Conditional_Delay (Full, Priv);
if Is_Tagged_Type (Full) then
Set_Direct_Primitive_Operations
(Full, Direct_Primitive_Operations (Priv));
Set_No_Tagged_Streams_Pragma
(Full, No_Tagged_Streams_Pragma (Priv));
if Is_Base_Type (Priv) then
Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
end if;
end if;
Set_Is_Volatile (Full, Is_Volatile (Priv));
Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
Set_Scope (Full, Scope (Priv));
Set_Prev_Entity (Full, Prev_Entity (Priv));
Set_Next_Entity (Full, Next_Entity (Priv));
Set_First_Entity (Full, First_Entity (Priv));
Set_Last_Entity (Full, Last_Entity (Priv));
-- If access types have been recorded for later handling, keep them in
-- the full view so that they get handled when the full view freeze
-- node is expanded.
if Present (Freeze_Node (Priv))
and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
then
Ensure_Freeze_Node (Full);
Set_Access_Types_To_Process
(Freeze_Node (Full),
Access_Types_To_Process (Freeze_Node (Priv)));
end if;
-- Swap the two entities. Now Private is the full type entity and Full
-- is the private one. They will be swapped back at the end of the
-- private part. This swapping ensures that the entity that is visible
-- in the private part is the full declaration.
Exchange_Entities (Priv, Full);
Append_Entity (Full, Scope (Full));
end Copy_And_Swap;
-------------------------------------
-- Copy_Array_Base_Type_Attributes --
-------------------------------------
procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
begin
Set_Component_Alignment (T1, Component_Alignment (T2));
Set_Component_Type (T1, Component_Type (T2));
Set_Component_Size (T1, Component_Size (T2));
Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
Propagate_Concurrent_Flags (T1, T2);
Set_Is_Packed (T1, Is_Packed (T2));
Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
Set_Has_Independent_Components (T1, Has_Independent_Components (T2));
Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
end Copy_Array_Base_Type_Attributes;
-----------------------------------
-- Copy_Array_Subtype_Attributes --
-----------------------------------
-- Note that we used to copy Packed_Array_Impl_Type too here, but we now
-- let it be recreated during freezing for the sake of better debug info.
procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
begin
Set_Size_Info (T1, T2);
Set_First_Index (T1, First_Index (T2));
Set_Is_Aliased (T1, Is_Aliased (T2));
Set_Is_Atomic (T1, Is_Atomic (T2));
Set_Is_Independent (T1, Is_Independent (T2));
Set_Is_Volatile (T1, Is_Volatile (T2));
Set_Is_Volatile_Full_Access (T1, Is_Volatile_Full_Access (T2));
Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
Set_Is_Constrained (T1, Is_Constrained (T2));
Set_Depends_On_Private (T1, Has_Private_Component (T2));
Inherit_Rep_Item_Chain (T1, T2);
Set_Convention (T1, Convention (T2));
Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
end Copy_Array_Subtype_Attributes;
-----------------------------------
-- Create_Constrained_Components --
-----------------------------------
procedure Create_Constrained_Components
(Subt : Entity_Id;
Decl_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id)
is
Loc : constant Source_Ptr := Sloc (Subt);
Comp_List : constant Elist_Id := New_Elmt_List;
Parent_Type : constant Entity_Id := Etype (Typ);
Assoc_List : constant List_Id := New_List;
Discr_Val : Elmt_Id;
Errors : Boolean;
New_C : Entity_Id;
Old_C : Entity_Id;
Is_Static : Boolean := True;
Is_Compile_Time_Known : Boolean := True;
procedure Collect_Fixed_Components (Typ : Entity_Id);
-- Collect parent type components that do not appear in a variant part
procedure Create_All_Components;
-- Iterate over Comp_List to create the components of the subtype
function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
-- Creates a new component from Old_Compon, copying all the fields from
-- it, including its Etype, inserts the new component in the Subt entity
-- chain and returns the new component.
function Is_Variant_Record (T : Entity_Id) return Boolean;
-- If true, and discriminants are static, collect only components from
-- variants selected by discriminant values.
------------------------------
-- Collect_Fixed_Components --
------------------------------
procedure Collect_Fixed_Components (Typ : Entity_Id) is
begin
-- Build association list for discriminants, and find components of the
-- variant part selected by the values of the discriminants.
Old_C := First_Discriminant (Typ);
Discr_Val := First_Elmt (Constraints);
while Present (Old_C) loop
Append_To (Assoc_List,
Make_Component_Association (Loc,
Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
Expression => New_Copy (Node (Discr_Val))));
Next_Elmt (Discr_Val);
Next_Discriminant (Old_C);
end loop;
-- The tag and the possible parent component are unconditionally in
-- the subtype.
if Is_Tagged_Type (Typ) or else Has_Controlled_Component (Typ) then
Old_C := First_Component (Typ);
while Present (Old_C) loop
if Chars (Old_C) in Name_uTag | Name_uParent then
Append_Elmt (Old_C, Comp_List);
end if;
Next_Component (Old_C);
end loop;
end if;
end Collect_Fixed_Components;
---------------------------
-- Create_All_Components --
---------------------------
procedure Create_All_Components is
Comp : Elmt_Id;
begin
Comp := First_Elmt (Comp_List);
while Present (Comp) loop
Old_C := Node (Comp);
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Elmt (Comp);
end loop;
end Create_All_Components;
----------------------
-- Create_Component --
----------------------
function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
New_Compon : constant Entity_Id := New_Copy (Old_Compon);
begin
if Ekind (Old_Compon) = E_Discriminant
and then Is_Completely_Hidden (Old_Compon)
then
-- This is a shadow discriminant created for a discriminant of
-- the parent type, which needs to be present in the subtype.
-- Give the shadow discriminant an internal name that cannot
-- conflict with that of visible components.
Set_Chars (New_Compon, New_Internal_Name ('C'));
end if;
-- Set the parent so we have a proper link for freezing etc. This is
-- not a real parent pointer, since of course our parent does not own
-- up to us and reference us, we are an illegitimate child of the
-- original parent.
Set_Parent (New_Compon, Parent (Old_Compon));
-- We do not want this node marked as Comes_From_Source, since
-- otherwise it would get first class status and a separate cross-
-- reference line would be generated. Illegitimate children do not
-- rate such recognition.
Set_Comes_From_Source (New_Compon, False);
-- But it is a real entity, and a birth certificate must be properly
-- registered by entering it into the entity list, and setting its
-- scope to the given subtype. This turns out to be useful for the
-- LLVM code generator, but that scope is not used otherwise.
Enter_Name (New_Compon);
Set_Scope (New_Compon, Subt);
return New_Compon;
end Create_Component;
-----------------------
-- Is_Variant_Record --
-----------------------
function Is_Variant_Record (T : Entity_Id) return Boolean is
begin
return Nkind (Parent (T)) = N_Full_Type_Declaration
and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
and then Present (Component_List (Type_Definition (Parent (T))))
and then
Present
(Variant_Part (Component_List (Type_Definition (Parent (T)))));
end Is_Variant_Record;
-- Start of processing for Create_Constrained_Components
begin
pragma Assert (Subt /= Base_Type (Subt));
pragma Assert (Typ = Base_Type (Typ));
Set_First_Entity (Subt, Empty);
Set_Last_Entity (Subt, Empty);
-- Check whether constraint is fully static, in which case we can
-- optimize the list of components.
Discr_Val := First_Elmt (Constraints);
while Present (Discr_Val) loop
if not Is_OK_Static_Expression (Node (Discr_Val)) then
Is_Static := False;
if not Compile_Time_Known_Value (Node (Discr_Val)) then
Is_Compile_Time_Known := False;
exit;
end if;
end if;
Next_Elmt (Discr_Val);
end loop;
Set_Has_Static_Discriminants (Subt, Is_Static);
Push_Scope (Subt);
-- Inherit the discriminants of the parent type
Add_Discriminants : declare
Num_Disc : Nat;
Num_Stor : Nat;
begin
Num_Disc := 0;
Old_C := First_Discriminant (Typ);
while Present (Old_C) loop
Num_Disc := Num_Disc + 1;
New_C := Create_Component (Old_C);
Set_Is_Public (New_C, Is_Public (Subt));
Next_Discriminant (Old_C);
end loop;
-- For an untagged derived subtype, the number of discriminants may
-- be smaller than the number of inherited discriminants, because
-- several of them may be renamed by a single new discriminant or
-- constrained. In this case, add the hidden discriminants back into
-- the subtype, because they need to be present if the optimizer of
-- the GCC 4.x back-end decides to break apart assignments between
-- objects using the parent view into member-wise assignments.
Num_Stor := 0;
if Is_Derived_Type (Typ)
and then not Is_Tagged_Type (Typ)
then
Old_C := First_Stored_Discriminant (Typ);
while Present (Old_C) loop
Num_Stor := Num_Stor + 1;
Next_Stored_Discriminant (Old_C);
end loop;
end if;
if Num_Stor > Num_Disc then
-- Find out multiple uses of new discriminants, and add hidden
-- components for the extra renamed discriminants. We recognize
-- multiple uses through the Corresponding_Discriminant of a
-- new discriminant: if it constrains several old discriminants,
-- this field points to the last one in the parent type. The
-- stored discriminants of the derived type have the same name
-- as those of the parent.
declare
Constr : Elmt_Id;
New_Discr : Entity_Id;
Old_Discr : Entity_Id;
begin
Constr := First_Elmt (Stored_Constraint (Typ));
Old_Discr := First_Stored_Discriminant (Typ);
while Present (Constr) loop
if Is_Entity_Name (Node (Constr))
and then Ekind (Entity (Node (Constr))) = E_Discriminant
then
New_Discr := Entity (Node (Constr));
if Chars (Corresponding_Discriminant (New_Discr)) /=
Chars (Old_Discr)
then
-- The new discriminant has been used to rename a
-- subsequent old discriminant. Introduce a shadow
-- component for the current old discriminant.
New_C := Create_Component (Old_Discr);
Set_Original_Record_Component (New_C, Old_Discr);
end if;
else
-- The constraint has eliminated the old discriminant.
-- Introduce a shadow component.
New_C := Create_Component (Old_Discr);
Set_Original_Record_Component (New_C, Old_Discr);
end if;
Next_Elmt (Constr);
Next_Stored_Discriminant (Old_Discr);
end loop;
end;
end if;
end Add_Discriminants;
if Is_Compile_Time_Known
and then Is_Variant_Record (Typ)
then
Collect_Fixed_Components (Typ);
Gather_Components
(Typ,
Component_List (Type_Definition (Parent (Typ))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors,
Allow_Compile_Time => True);
pragma Assert (not Errors or else Serious_Errors_Detected > 0);
Create_All_Components;
-- If the subtype declaration is created for a tagged type derivation
-- with constraints, we retrieve the record definition of the parent
-- type to select the components of the proper variant.
elsif Is_Compile_Time_Known
and then Is_Tagged_Type (Typ)
and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
and then
Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
and then Is_Variant_Record (Parent_Type)
then
Collect_Fixed_Components (Typ);
Gather_Components
(Typ,
Component_List (Type_Definition (Parent (Parent_Type))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors,
Allow_Compile_Time => True);
-- Note: previously there was a check at this point that no errors
-- were detected. As a consequence of AI05-220 there may be an error
-- if an inherited discriminant that controls a variant has a non-
-- static constraint.
-- If the tagged derivation has a type extension, collect all the
-- new relevant components therein via Gather_Components.
if Present (Record_Extension_Part (Type_Definition (Parent (Typ))))
then
Gather_Components
(Typ,
Component_List
(Record_Extension_Part (Type_Definition (Parent (Typ)))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors,
Allow_Compile_Time => True,
Include_Interface_Tag => True);
end if;
Create_All_Components;
else
-- If discriminants are not static, or if this is a multi-level type
-- extension, we have to include all components of the parent type.
Old_C := First_Component (Typ);
while Present (Old_C) loop
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Component (Old_C);
end loop;
end if;
End_Scope;
end Create_Constrained_Components;
------------------------------------------
-- Decimal_Fixed_Point_Type_Declaration --
------------------------------------------
procedure Decimal_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Digs_Expr : constant Node_Id := Digits_Expression (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
Max_Digits : constant Nat :=
(if System_Max_Integer_Size = 128 then 38 else 18);
-- Maximum number of digits that can be represented in an integer
Implicit_Base : Entity_Id;
Digs_Val : Uint;
Delta_Val : Ureal;
Scale_Val : Uint;
Bound_Val : Ureal;
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Universal_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
-- Check delta is power of 10, and determine scale value from it
declare
Val : Ureal;
begin
Scale_Val := Uint_0;
Val := Delta_Val;
if Val < Ureal_1 then
while Val < Ureal_1 loop
Val := Val * Ureal_10;
Scale_Val := Scale_Val + 1;
end loop;
if Scale_Val > Max_Digits then
Error_Msg_Uint_1 := UI_From_Int (Max_Digits);
Error_Msg_N ("scale exceeds maximum value of ^", Def);
Scale_Val := UI_From_Int (Max_Digits);
end if;
else
while Val > Ureal_1 loop
Val := Val / Ureal_10;
Scale_Val := Scale_Val - 1;
end loop;
if Scale_Val < -Max_Digits then
Error_Msg_Uint_1 := UI_From_Int (-Max_Digits);
Error_Msg_N ("scale is less than minimum value of ^", Def);
Scale_Val := UI_From_Int (-Max_Digits);
end if;
end if;
if Val /= Ureal_1 then
Error_Msg_N ("delta expression must be a power of 10", Def);
Delta_Val := Ureal_10 ** (-Scale_Val);
end if;
end;
-- Set delta, scale and small (small = delta for decimal type)
Set_Delta_Value (Implicit_Base, Delta_Val);
Set_Scale_Value (Implicit_Base, Scale_Val);
Set_Small_Value (Implicit_Base, Delta_Val);
-- Analyze and process digits expression
Analyze_And_Resolve (Digs_Expr, Any_Integer);
Check_Digits_Expression (Digs_Expr);
Digs_Val := Expr_Value (Digs_Expr);
if Digs_Val > Max_Digits then
Error_Msg_Uint_1 := UI_From_Int (Max_Digits);
Error_Msg_N ("digits value out of range, maximum is ^", Digs_Expr);
Digs_Val := UI_From_Int (Max_Digits);
end if;
Set_Digits_Value (Implicit_Base, Digs_Val);
Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
-- Set range of base type from digits value for now. This will be
-- expanded to represent the true underlying base range by Freeze.
Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
-- Note: We leave Esize unset for now, size will be set at freeze
-- time. We have to do this for ordinary fixed-point, because the size
-- depends on the specified small, and we might as well do the same for
-- decimal fixed-point.
pragma Assert (not Known_Esize (Implicit_Base));
-- If there are bounds given in the declaration use them as the
-- bounds of the first named subtype.
if Present (Real_Range_Specification (Def)) then
declare
RRS : constant Node_Id := Real_Range_Specification (Def);
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
Low_Val : Ureal;
High_Val : Ureal;
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val < (-Bound_Val) then
Error_Msg_N
("range low bound too small for digits value", Low);
Low_Val := -Bound_Val;
end if;
if High_Val > Bound_Val then
Error_Msg_N
("range high bound too large for digits value", High);
High_Val := Bound_Val;
end if;
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
end;
-- If no explicit range, use range that corresponds to given
-- digits value. This will end up as the final range for the
-- first subtype.
else
Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
end if;
-- Complete entity for first subtype. The inheritance of the rep item
-- chain ensures that SPARK-related pragmas are not clobbered when the
-- decimal fixed point type acts as a full view of a private type.
Mutate_Ekind (T, E_Decimal_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, Implicit_Base);
Inherit_Rep_Item_Chain (T, Implicit_Base);
Set_Digits_Value (T, Digs_Val);
Set_Delta_Value (T, Delta_Val);
Set_Small_Value (T, Delta_Val);
Set_Scale_Value (T, Scale_Val);
Set_Is_Constrained (T);
end Decimal_Fixed_Point_Type_Declaration;
-----------------------------------
-- Derive_Progenitor_Subprograms --
-----------------------------------
procedure Derive_Progenitor_Subprograms
(Parent_Type : Entity_Id;
Tagged_Type : Entity_Id)
is
E : Entity_Id;
Elmt : Elmt_Id;
Iface : Entity_Id;
Iface_Alias : Entity_Id;
Iface_Elmt : Elmt_Id;
Iface_Subp : Entity_Id;
New_Subp : Entity_Id := Empty;
Prim_Elmt : Elmt_Id;
Subp : Entity_Id;
Typ : Entity_Id;
begin
pragma Assert (Ada_Version >= Ada_2005
and then Is_Record_Type (Tagged_Type)
and then Is_Tagged_Type (Tagged_Type)
and then Has_Interfaces (Tagged_Type));
-- Step 1: Transfer to the full-view primitives associated with the
-- partial-view that cover interface primitives. Conceptually this
-- work should be done later by Process_Full_View; done here to
-- simplify its implementation at later stages. It can be safely
-- done here because interfaces must be visible in the partial and
-- private view (RM 7.3(7.3/2)).
-- Small optimization: This work is only required if the parent may
-- have entities whose Alias attribute reference an interface primitive.
-- Such a situation may occur if the parent is an abstract type and the
-- primitive has not been yet overridden or if the parent is a generic
-- formal type covering interfaces.
-- If the tagged type is not abstract, it cannot have abstract
-- primitives (the only entities in the list of primitives of
-- non-abstract tagged types that can reference abstract primitives
-- through its Alias attribute are the internal entities that have
-- attribute Interface_Alias, and these entities are generated later
-- by Add_Internal_Interface_Entities).
if In_Private_Part (Current_Scope)
and then (Is_Abstract_Type (Parent_Type)
or else
Is_Generic_Type (Parent_Type))
then
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
while Present (Elmt) loop
Subp := Node (Elmt);
-- At this stage it is not possible to have entities in the list
-- of primitives that have attribute Interface_Alias.
pragma Assert (No (Interface_Alias (Subp)));
Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
if Is_Interface (Typ) then
E := Find_Primitive_Covering_Interface
(Tagged_Type => Tagged_Type,
Iface_Prim => Subp);
if Present (E)
and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
then
Replace_Elmt (Elmt, E);
Remove_Homonym (Subp);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end if;
-- Step 2: Add primitives of progenitors that are not implemented by
-- parents of Tagged_Type.
if Present (Interfaces (Base_Type (Tagged_Type))) then
Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
while Present (Prim_Elmt) loop
Iface_Subp := Node (Prim_Elmt);
Iface_Alias := Ultimate_Alias (Iface_Subp);
-- Exclude derivation of predefined primitives except those
-- that come from source, or are inherited from one that comes
-- from source. Required to catch declarations of equality
-- operators of interfaces. For example:
-- type Iface is interface;
-- function "=" (Left, Right : Iface) return Boolean;
if not Is_Predefined_Dispatching_Operation (Iface_Subp)
or else Comes_From_Source (Iface_Alias)
then
E :=
Find_Primitive_Covering_Interface
(Tagged_Type => Tagged_Type,
Iface_Prim => Iface_Subp);
-- If not found we derive a new primitive leaving its alias
-- attribute referencing the interface primitive.
if No (E) then
Derive_Subprogram
(New_Subp, Iface_Subp, Tagged_Type, Iface);
-- Ada 2012 (AI05-0197): If the covering primitive's name
-- differs from the name of the interface primitive then it
-- is a private primitive inherited from a parent type. In
-- such case, given that Tagged_Type covers the interface,
-- the inherited private primitive becomes visible. For such
-- purpose we add a new entity that renames the inherited
-- private primitive.
elsif Chars (E) /= Chars (Iface_Subp) then
pragma Assert (Has_Suffix (E, 'P'));
Derive_Subprogram
(New_Subp, Iface_Subp, Tagged_Type, Iface);
Set_Alias (New_Subp, E);
Set_Is_Abstract_Subprogram (New_Subp,
Is_Abstract_Subprogram (E));
-- Propagate to the full view interface entities associated
-- with the partial view.
elsif In_Private_Part (Current_Scope)
and then Present (Alias (E))
and then Alias (E) = Iface_Subp
and then
List_Containing (Parent (E)) /=
Private_Declarations
(Specification
(Unit_Declaration_Node (Current_Scope)))
then
Append_Elmt (E, Primitive_Operations (Tagged_Type));
end if;
end if;
Next_Elmt (Prim_Elmt);
end loop;
Next_Elmt (Iface_Elmt);
end loop;
end if;
end Derive_Progenitor_Subprograms;
-----------------------
-- Derive_Subprogram --
-----------------------
procedure Derive_Subprogram
(New_Subp : out Entity_Id;
Parent_Subp : Entity_Id;
Derived_Type : Entity_Id;
Parent_Type : Entity_Id;
Actual_Subp : Entity_Id := Empty)
is
Formal : Entity_Id;
-- Formal parameter of parent primitive operation
Formal_Of_Actual : Entity_Id;
-- Formal parameter of actual operation, when the derivation is to
-- create a renaming for a primitive operation of an actual in an
-- instantiation.
New_Formal : Entity_Id;
-- Formal of inherited operation
Visible_Subp : Entity_Id := Parent_Subp;
function Is_Private_Overriding return Boolean;
-- If Subp is a private overriding of a visible operation, the inherited
-- operation derives from the overridden op (even though its body is the
-- overriding one) and the inherited operation is visible now. See
-- sem_disp to see the full details of the handling of the overridden
-- subprogram, which is removed from the list of primitive operations of
-- the type. The overridden subprogram is saved locally in Visible_Subp,
-- and used to diagnose abstract operations that need overriding in the
-- derived type.
procedure Replace_Type (Id, New_Id : Entity_Id);
-- When the type is an anonymous access type, create a new access type
-- designating the derived type.
procedure Set_Derived_Name;
-- This procedure sets the appropriate Chars name for New_Subp. This
-- is normally just a copy of the parent name. An exception arises for
-- type support subprograms, where the name is changed to reflect the
-- name of the derived type, e.g. if type foo is derived from type bar,
-- then a procedure barDA is derived with a name fooDA.
---------------------------
-- Is_Private_Overriding --
---------------------------
function Is_Private_Overriding return Boolean is
Prev : Entity_Id;
begin
-- If the parent is not a dispatching operation there is no
-- need to investigate overridings
if not Is_Dispatching_Operation (Parent_Subp) then
return False;
end if;
-- The visible operation that is overridden is a homonym of the
-- parent subprogram. We scan the homonym chain to find the one
-- whose alias is the subprogram we are deriving.
Prev := Current_Entity (Parent_Subp);
while Present (Prev) loop
if Ekind (Prev) = Ekind (Parent_Subp)
and then Alias (Prev) = Parent_Subp
and then Scope (Parent_Subp) = Scope (Prev)
and then not Is_Hidden (Prev)
then
Visible_Subp := Prev;
return True;
end if;
Prev := Homonym (Prev);
end loop;
return False;
end Is_Private_Overriding;
------------------
-- Replace_Type --
------------------
procedure Replace_Type (Id, New_Id : Entity_Id) is
Id_Type : constant Entity_Id := Etype (Id);
Acc_Type : Entity_Id;
Par : constant Node_Id := Parent (Derived_Type);
begin
-- When the type is an anonymous access type, create a new access
-- type designating the derived type. This itype must be elaborated
-- at the point of the derivation, not on subsequent calls that may
-- be out of the proper scope for Gigi, so we insert a reference to
-- it after the derivation.
if Ekind (Id_Type) = E_Anonymous_Access_Type then
declare
Desig_Typ : Entity_Id := Designated_Type (Id_Type);
begin
if Ekind (Desig_Typ) = E_Record_Type_With_Private
and then Present (Full_View (Desig_Typ))
and then not Is_Private_Type (Parent_Type)
then
Desig_Typ := Full_View (Desig_Typ);
end if;
if Base_Type (Desig_Typ) = Base_Type (Parent_Type)
-- Ada 2005 (AI-251): Handle also derivations of abstract
-- interface primitives.
or else (Is_Interface (Desig_Typ)
and then not Is_Class_Wide_Type (Desig_Typ))
then
Acc_Type := New_Copy (Id_Type);
Set_Etype (Acc_Type, Acc_Type);
Set_Scope (Acc_Type, New_Subp);
-- Set size of anonymous access type. If we have an access
-- to an unconstrained array, this is a fat pointer, so it
-- is sizes at twice addtress size.
if Is_Array_Type (Desig_Typ)
and then not Is_Constrained (Desig_Typ)
then
Init_Size (Acc_Type, 2 * System_Address_Size);
-- Other cases use a thin pointer
else
Init_Size (Acc_Type, System_Address_Size);
end if;
-- Set remaining characterstics of anonymous access type
Reinit_Alignment (Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Derived_Type);
Set_Etype (New_Id, Acc_Type);
Set_Scope (New_Id, New_Subp);
-- Create a reference to it
Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
else
Set_Etype (New_Id, Id_Type);
end if;
end;
-- In Ada2012, a formal may have an incomplete type but the type
-- derivation that inherits the primitive follows the full view.
elsif Base_Type (Id_Type) = Base_Type (Parent_Type)
or else
(Ekind (Id_Type) = E_Record_Type_With_Private
and then Present (Full_View (Id_Type))
and then
Base_Type (Full_View (Id_Type)) = Base_Type (Parent_Type))
or else
(Ada_Version >= Ada_2012
and then Ekind (Id_Type) = E_Incomplete_Type
and then Full_View (Id_Type) = Parent_Type)
then
-- Constraint checks on formals are generated during expansion,
-- based on the signature of the original subprogram. The bounds
-- of the derived type are not relevant, and thus we can use
-- the base type for the formals. However, the return type may be
-- used in a context that requires that the proper static bounds
-- be used (a case statement, for example) and for those cases
-- we must use the derived type (first subtype), not its base.
-- If the derived_type_definition has no constraints, we know that
-- the derived type has the same constraints as the first subtype
-- of the parent, and we can also use it rather than its base,
-- which can lead to more efficient code.
if Etype (Id) = Parent_Type then
if Is_Scalar_Type (Parent_Type)
and then
Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
then
Set_Etype (New_Id, Derived_Type);
elsif Nkind (Par) = N_Full_Type_Declaration
and then
Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
and then
Is_Entity_Name
(Subtype_Indication (Type_Definition (Par)))
then
Set_Etype (New_Id, Derived_Type);
else
Set_Etype (New_Id, Base_Type (Derived_Type));
end if;
else
Set_Etype (New_Id, Base_Type (Derived_Type));
end if;
else
Set_Etype (New_Id, Etype (Id));
end if;
end Replace_Type;
----------------------
-- Set_Derived_Name --
----------------------
procedure Set_Derived_Name is
Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
begin
if Nm = TSS_Null then
Set_Chars (New_Subp, Chars (Parent_Subp));
else
Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
end if;
end Set_Derived_Name;
-- Start of processing for Derive_Subprogram
begin
New_Subp := New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
Mutate_Ekind (New_Subp, Ekind (Parent_Subp));
-- Check whether the inherited subprogram is a private operation that
-- should be inherited but not yet made visible. Such subprograms can
-- become visible at a later point (e.g., the private part of a public
-- child unit) via Declare_Inherited_Private_Subprograms. If the
-- following predicate is true, then this is not such a private
-- operation and the subprogram simply inherits the name of the parent
-- subprogram. Note the special check for the names of controlled
-- operations, which are currently exempted from being inherited with
-- a hidden name because they must be findable for generation of
-- implicit run-time calls.
if not Is_Hidden (Parent_Subp)
or else Is_Internal (Parent_Subp)
or else Is_Private_Overriding
or else Is_Internal_Name (Chars (Parent_Subp))
or else (Is_Controlled (Parent_Type)
and then Chars (Parent_Subp) in Name_Adjust
| Name_Finalize
| Name_Initialize)
then
Set_Derived_Name;
-- An inherited dispatching equality will be overridden by an internally
-- generated one, or by an explicit one, so preserve its name and thus
-- its entry in the dispatch table. Otherwise, if Parent_Subp is a
-- private operation it may become invisible if the full view has
-- progenitors, and the dispatch table will be malformed.
-- We check that the type is limited to handle the anomalous declaration
-- of Limited_Controlled, which is derived from a non-limited type, and
-- which is handled specially elsewhere as well.
elsif Chars (Parent_Subp) = Name_Op_Eq
and then Is_Dispatching_Operation (Parent_Subp)
and then Etype (Parent_Subp) = Standard_Boolean
and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
and then
Etype (First_Formal (Parent_Subp)) =
Etype (Next_Formal (First_Formal (Parent_Subp)))
then
Set_Derived_Name;
-- If parent is hidden, this can be a regular derivation if the
-- parent is immediately visible in a non-instantiating context,
-- or if we are in the private part of an instance. This test
-- should still be refined ???
-- The test for In_Instance_Not_Visible avoids inheriting the derived
-- operation as a non-visible operation in cases where the parent
-- subprogram might not be visible now, but was visible within the
-- original generic, so it would be wrong to make the inherited
-- subprogram non-visible now. (Not clear if this test is fully
-- correct; are there any cases where we should declare the inherited
-- operation as not visible to avoid it being overridden, e.g., when
-- the parent type is a generic actual with private primitives ???)
-- (they should be treated the same as other private inherited
-- subprograms, but it's not clear how to do this cleanly). ???
elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
and then Is_Immediately_Visible (Parent_Subp)
and then not In_Instance)
or else In_Instance_Not_Visible
then
Set_Derived_Name;
-- Ada 2005 (AI-251): Regular derivation if the parent subprogram
-- overrides an interface primitive because interface primitives
-- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
elsif Ada_Version >= Ada_2005
and then Is_Dispatching_Operation (Parent_Subp)
and then Present (Covered_Interface_Op (Parent_Subp))
then
Set_Derived_Name;
-- Otherwise, the type is inheriting a private operation, so enter it
-- with a special name so it can't be overridden. See also below, where
-- we check for this case, and if so avoid setting Requires_Overriding.
else
Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
end if;
Set_Parent (New_Subp, Parent (Derived_Type));
if Present (Actual_Subp) then
Replace_Type (Actual_Subp, New_Subp);
else
Replace_Type (Parent_Subp, New_Subp);
end if;
Conditional_Delay (New_Subp, Parent_Subp);
-- If we are creating a renaming for a primitive operation of an
-- actual of a generic derived type, we must examine the signature
-- of the actual primitive, not that of the generic formal, which for
-- example may be an interface. However the name and initial value
-- of the inherited operation are those of the formal primitive.
Formal := First_Formal (Parent_Subp);
if Present (Actual_Subp) then
Formal_Of_Actual := First_Formal (Actual_Subp);
else
Formal_Of_Actual := Empty;
end if;
while Present (Formal) loop
New_Formal := New_Copy (Formal);
-- Extra formals are not inherited from a limited interface parent
-- since limitedness is not inherited in such case (AI-419) and this
-- affects the extra formals.
if Is_Limited_Interface (Parent_Type) then
Set_Extra_Formal (New_Formal, Empty);
Set_Extra_Accessibility (New_Formal, Empty);
end if;
-- Normally we do not go copying parents, but in the case of
-- formals, we need to link up to the declaration (which is the
-- parameter specification), and it is fine to link up to the
-- original formal's parameter specification in this case.
Set_Parent (New_Formal, Parent (Formal));
Append_Entity (New_Formal, New_Subp);
if Present (Formal_Of_Actual) then
Replace_Type (Formal_Of_Actual, New_Formal);
Next_Formal (Formal_Of_Actual);
else
Replace_Type (Formal, New_Formal);
end if;
Next_Formal (Formal);
end loop;
-- Extra formals are shared between the parent subprogram and this
-- internal entity built by Derive_Subprogram (implicit in the above
-- copy of formals), unless the parent type is a limited interface type;
-- hence we must inherit also the reference to the first extra formal.
-- When the parent type is an interface, the extra formals will be added
-- when the tagged type is frozen (see Expand_Freeze_Record_Type).
if not Is_Limited_Interface (Parent_Type) then
Set_Extra_Formals (New_Subp, Extra_Formals (Parent_Subp));
if Ekind (New_Subp) = E_Function then
Set_Extra_Accessibility_Of_Result (New_Subp,
Extra_Accessibility_Of_Result (Parent_Subp));
end if;
end if;
-- If this derivation corresponds to a tagged generic actual, then
-- primitive operations rename those of the actual. Otherwise the
-- primitive operations rename those of the parent type, If the parent
-- renames an intrinsic operator, so does the new subprogram. We except
-- concatenation, which is always properly typed, and does not get
-- expanded as other intrinsic operations.
if No (Actual_Subp) then
if Is_Intrinsic_Subprogram (Parent_Subp) then
Set_Is_Intrinsic_Subprogram (New_Subp);
if Present (Alias (Parent_Subp))
and then Chars (Parent_Subp) /= Name_Op_Concat
then
Set_Alias (New_Subp, Alias (Parent_Subp));
else
Set_Alias (New_Subp, Parent_Subp);
end if;
else
Set_Alias (New_Subp, Parent_Subp);
end if;
else
Set_Alias (New_Subp, Actual_Subp);
end if;
Copy_Strub_Mode (New_Subp, Alias (New_Subp));
-- Derived subprograms of a tagged type must inherit the convention
-- of the parent subprogram (a requirement of AI95-117). Derived
-- subprograms of untagged types simply get convention Ada by default.
-- If the derived type is a tagged generic formal type with unknown
-- discriminants, its convention is intrinsic (RM 6.3.1 (8)).
-- However, if the type is derived from a generic formal, the further
-- inherited subprogram has the convention of the non-generic ancestor.
-- Otherwise there would be no way to override the operation.
-- (This is subject to forthcoming ARG discussions).
if Is_Tagged_Type (Derived_Type) then
if Is_Generic_Type (Derived_Type)
and then Has_Unknown_Discriminants (Derived_Type)
then
Set_Convention (New_Subp, Convention_Intrinsic);
else
if Is_Generic_Type (Parent_Type)
and then Has_Unknown_Discriminants (Parent_Type)
then
Set_Convention (New_Subp, Convention (Alias (Parent_Subp)));
else
Set_Convention (New_Subp, Convention (Parent_Subp));
end if;
end if;
end if;
-- Predefined controlled operations retain their name even if the parent
-- is hidden (see above), but they are not primitive operations if the
-- ancestor is not visible, for example if the parent is a private
-- extension completed with a controlled extension. Note that a full
-- type that is controlled can break privacy: the flag Is_Controlled is
-- set on both views of the type.
if Is_Controlled (Parent_Type)
and then Chars (Parent_Subp) in Name_Initialize
| Name_Adjust
| Name_Finalize
and then Is_Hidden (Parent_Subp)
and then not Is_Visibly_Controlled (Parent_Type)
then
Set_Is_Hidden (New_Subp);
end if;
Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
if Ekind (Parent_Subp) = E_Procedure then
Set_Is_Valued_Procedure
(New_Subp, Is_Valued_Procedure (Parent_Subp));
else
Set_Has_Controlling_Result
(New_Subp, Has_Controlling_Result (Parent_Subp));
end if;
-- No_Return must be inherited properly. If this is overridden in the
-- case of a dispatching operation, then the check is made later in
-- Check_Abstract_Overriding that the overriding operation is also
-- No_Return (no such check is required for the nondispatching case).
Set_No_Return (New_Subp, No_Return (Parent_Subp));
-- If the parent subprogram is marked as Ghost, then so is the derived
-- subprogram. The ghost policy for the derived subprogram is set from
-- the effective ghost policy at the point of derived type declaration.
if Is_Ghost_Entity (Parent_Subp) then
Set_Is_Ghost_Entity (New_Subp);
end if;
-- A derived function with a controlling result is abstract. If the
-- Derived_Type is a nonabstract formal generic derived type, then
-- inherited operations are not abstract: the required check is done at
-- instantiation time. If the derivation is for a generic actual, the
-- function is not abstract unless the actual is.
if Is_Generic_Type (Derived_Type)
and then not Is_Abstract_Type (Derived_Type)
then
null;
-- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
-- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2). Note
-- that functions with controlling access results of record extensions
-- with a null extension part require overriding (AI95-00391/06).
-- Ada 2022 (AI12-0042): Similarly, set those properties for
-- implementing the rule of RM 7.3.2(6.1/4).
-- A subprogram subject to pragma Extensions_Visible with value False
-- requires overriding if the subprogram has at least one controlling
-- OUT parameter (SPARK RM 6.1.7(6)).
elsif Ada_Version >= Ada_2005
and then (Is_Abstract_Subprogram (Alias (New_Subp))
or else (Is_Tagged_Type (Derived_Type)
and then Etype (New_Subp) = Derived_Type
and then not Is_Null_Extension (Derived_Type))
or else (Is_Tagged_Type (Derived_Type)
and then Ekind (Etype (New_Subp)) =
E_Anonymous_Access_Type
and then Designated_Type (Etype (New_Subp)) =
Derived_Type)
or else (Comes_From_Source (Alias (New_Subp))
and then Is_EVF_Procedure (Alias (New_Subp)))
-- AI12-0042: Set Requires_Overriding when a type extension
-- inherits a private operation that is visible at the
-- point of extension (Has_Private_Ancestor is False) from
-- an ancestor that has Type_Invariant'Class, and when the
-- type extension is in a visible part (the latter as
-- clarified by AI12-0382).
or else
(not Has_Private_Ancestor (Derived_Type)
and then Has_Invariants (Parent_Type)
and then
Present (Get_Pragma (Parent_Type, Pragma_Invariant))
and then
Class_Present
(Get_Pragma (Parent_Type, Pragma_Invariant))
and then Is_Private_Primitive (Parent_Subp)
and then In_Visible_Part (Scope (Derived_Type))))
and then No (Actual_Subp)
then
if not Is_Tagged_Type (Derived_Type)
or else Is_Abstract_Type (Derived_Type)
or else Is_Abstract_Subprogram (Alias (New_Subp))
then
Set_Is_Abstract_Subprogram (New_Subp);
-- If the Chars of the new subprogram is different from that of the
-- parent's one, it means that we entered it with a special name so
-- it can't be overridden (see above). In that case we had better not
-- *require* it to be overridden. This is the case where the parent
-- type inherited the operation privately, so there's no danger of
-- dangling dispatching.
elsif Chars (New_Subp) = Chars (Alias (New_Subp)) then
Set_Requires_Overriding (New_Subp);
end if;
elsif Ada_Version < Ada_2005
and then (Is_Abstract_Subprogram (Alias (New_Subp))
or else (Is_Tagged_Type (Derived_Type)
and then Etype (New_Subp) = Derived_Type
and then No (Actual_Subp)))
then
Set_Is_Abstract_Subprogram (New_Subp);
-- AI05-0097 : an inherited operation that dispatches on result is
-- abstract if the derived type is abstract, even if the parent type
-- is concrete and the derived type is a null extension.
elsif Has_Controlling_Result (Alias (New_Subp))
and then Is_Abstract_Type (Etype (New_Subp))
then
Set_Is_Abstract_Subprogram (New_Subp);
-- Finally, if the parent type is abstract we must verify that all
-- inherited operations are either non-abstract or overridden, or that
-- the derived type itself is abstract (this check is performed at the
-- end of a package declaration, in Check_Abstract_Overriding). A
-- private overriding in the parent type will not be visible in the
-- derivation if we are not in an inner package or in a child unit of
-- the parent type, in which case the abstractness of the inherited
-- operation is carried to the new subprogram.
elsif Is_Abstract_Type (Parent_Type)
and then not In_Open_Scopes (Scope (Parent_Type))
and then Is_Private_Overriding
and then Is_Abstract_Subprogram (Visible_Subp)
then
if No (Actual_Subp) then
Set_Alias (New_Subp, Visible_Subp);
Set_Is_Abstract_Subprogram (New_Subp, True);
else
-- If this is a derivation for an instance of a formal derived
-- type, abstractness comes from the primitive operation of the
-- actual, not from the operation inherited from the ancestor.
Set_Is_Abstract_Subprogram
(New_Subp, Is_Abstract_Subprogram (Actual_Subp));
end if;
end if;
New_Overloaded_Entity (New_Subp, Derived_Type);
-- Ada RM 6.1.1 (15): If a subprogram inherits nonconforming class-wide
-- preconditions and the derived type is abstract, the derived operation
-- is abstract as well if parent subprogram is not abstract or null.
if Is_Abstract_Type (Derived_Type)
and then Has_Non_Trivial_Precondition (Parent_Subp)
and then Present (Interfaces (Derived_Type))
then
-- Add useful attributes of subprogram before the freeze point,
-- in case freezing is delayed or there are previous errors.
Set_Is_Dispatching_Operation (New_Subp);
declare
Iface_Prim : constant Entity_Id := Covered_Interface_Op (New_Subp);
begin
if Present (Iface_Prim)
and then Has_Non_Trivial_Precondition (Iface_Prim)
then
Set_Is_Abstract_Subprogram (New_Subp);
end if;
end;
end if;
-- Check for case of a derived subprogram for the instantiation of a
-- formal derived tagged type, if so mark the subprogram as dispatching
-- and inherit the dispatching attributes of the actual subprogram. The
-- derived subprogram is effectively renaming of the actual subprogram,
-- so it needs to have the same attributes as the actual.
if Present (Actual_Subp)
and then Is_Dispatching_Operation (Actual_Subp)
then
Set_Is_Dispatching_Operation (New_Subp);
if Present (DTC_Entity (Actual_Subp)) then
Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
Set_DT_Position_Value (New_Subp, DT_Position (Actual_Subp));
end if;
end if;
-- Indicate that a derived subprogram does not require a body and that
-- it does not require processing of default expressions.
Set_Has_Completion (New_Subp);
Set_Default_Expressions_Processed (New_Subp);
if Ekind (New_Subp) = E_Function then
Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
Set_Returns_By_Ref (New_Subp, Returns_By_Ref (Parent_Subp));
end if;
-- Ada 2022 (AI12-0279): If a Yield aspect is specified True for a
-- primitive subprogram S of a type T, then the aspect is inherited
-- by the corresponding primitive subprogram of each descendant of T.
if Is_Tagged_Type (Derived_Type)
and then Is_Dispatching_Operation (New_Subp)
and then Has_Yield_Aspect (Alias (New_Subp))
then
Set_Has_Yield_Aspect (New_Subp, Has_Yield_Aspect (Alias (New_Subp)));
end if;
Set_Is_Ada_2022_Only (New_Subp, Is_Ada_2022_Only (Parent_Subp));
end Derive_Subprogram;
------------------------
-- Derive_Subprograms --
------------------------
procedure Derive_Subprograms
(Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Generic_Actual : Entity_Id := Empty)
is
Op_List : constant Elist_Id :=
Collect_Primitive_Operations (Parent_Type);
function Check_Derived_Type return Boolean;
-- Check that all the entities derived from Parent_Type are found in
-- the list of primitives of Derived_Type exactly in the same order.
procedure Derive_Interface_Subprogram
(New_Subp : out Entity_Id;
Subp : Entity_Id;
Actual_Subp : Entity_Id);
-- Derive New_Subp from the ultimate alias of the parent subprogram Subp
-- (which is an interface primitive). If Generic_Actual is present then
-- Actual_Subp is the actual subprogram corresponding with the generic
-- subprogram Subp.
------------------------
-- Check_Derived_Type --
------------------------
function Check_Derived_Type return Boolean is
E : Entity_Id;
Derived_Elmt : Elmt_Id;
Derived_Op : Entity_Id;
Derived_Ops : Elist_Id;
Parent_Elmt : Elmt_Id;
Parent_Op : Entity_Id;
begin
-- Traverse list of entities in the current scope searching for
-- an incomplete type whose full-view is derived type.
E := First_Entity (Scope (Derived_Type));
while Present (E) and then E /= Derived_Type loop
if Ekind (E) = E_Incomplete_Type
and then Present (Full_View (E))
and then Full_View (E) = Derived_Type
then
-- Disable this test if Derived_Type completes an incomplete
-- type because in such case more primitives can be added
-- later to the list of primitives of Derived_Type by routine
-- Process_Incomplete_Dependents.
return True;
end if;
Next_Entity (E);
end loop;
Derived_Ops := Collect_Primitive_Operations (Derived_Type);
Derived_Elmt := First_Elmt (Derived_Ops);
Parent_Elmt := First_Elmt (Op_List);
while Present (Parent_Elmt) loop
Parent_Op := Node (Parent_Elmt);
Derived_Op := Node (Derived_Elmt);
-- At this early stage Derived_Type has no entities with attribute
-- Interface_Alias. In addition, such primitives are always
-- located at the end of the list of primitives of Parent_Type.
-- Therefore, if found we can safely stop processing pending
-- entities.
exit when Present (Interface_Alias (Parent_Op));
-- Handle hidden entities
if not Is_Predefined_Dispatching_Operation (Parent_Op)
and then Is_Hidden (Parent_Op)
then
if Present (Derived_Op)
and then Primitive_Names_Match (Parent_Op, Derived_Op)
then
Next_Elmt (Derived_Elmt);
end if;
else
if No (Derived_Op)
or else Ekind (Parent_Op) /= Ekind (Derived_Op)
or else not Primitive_Names_Match (Parent_Op, Derived_Op)
then
return False;
end if;
Next_Elmt (Derived_Elmt);
end if;
Next_Elmt (Parent_Elmt);
end loop;
return True;
end Check_Derived_Type;
---------------------------------
-- Derive_Interface_Subprogram --
---------------------------------
procedure Derive_Interface_Subprogram
(New_Subp : out Entity_Id;
Subp : Entity_Id;
Actual_Subp : Entity_Id)
is
Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
begin
pragma Assert (Is_Interface (Iface_Type));
Derive_Subprogram
(New_Subp => New_Subp,
Parent_Subp => Iface_Subp,
Derived_Type => Derived_Type,
Parent_Type => Iface_Type,
Actual_Subp => Actual_Subp);
-- Given that this new interface entity corresponds with a primitive
-- of the parent that was not overridden we must leave it associated
-- with its parent primitive to ensure that it will share the same
-- dispatch table slot when overridden. We must set the Alias to Subp
-- (instead of Iface_Subp), and we must fix Is_Abstract_Subprogram
-- (in case we inherited Subp from Iface_Type via a nonabstract
-- generic formal type).
if No (Actual_Subp) then
Set_Alias (New_Subp, Subp);
declare
T : Entity_Id := Find_Dispatching_Type (Subp);
begin
while Etype (T) /= T loop
if Is_Generic_Type (T) and then not Is_Abstract_Type (T) then
Set_Is_Abstract_Subprogram (New_Subp, False);
exit;
end if;
T := Etype (T);
end loop;
end;
-- For instantiations this is not needed since the previous call to
-- Derive_Subprogram leaves the entity well decorated.
else
pragma Assert (Alias (New_Subp) = Actual_Subp);
null;
end if;
end Derive_Interface_Subprogram;
-- Local variables
Alias_Subp : Entity_Id;
Act_List : Elist_Id;
Act_Elmt : Elmt_Id;
Act_Subp : Entity_Id := Empty;
Elmt : Elmt_Id;
Need_Search : Boolean := False;
New_Subp : Entity_Id;
Parent_Base : Entity_Id;
Subp : Entity_Id;
-- Start of processing for Derive_Subprograms
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Has_Discriminants (Parent_Type)
and then Present (Full_View (Parent_Type))
then
Parent_Base := Full_View (Parent_Type);
else
Parent_Base := Parent_Type;
end if;
if Present (Generic_Actual) then
Act_List := Collect_Primitive_Operations (Generic_Actual);
Act_Elmt := First_Elmt (Act_List);
else
Act_List := No_Elist;
Act_Elmt := No_Elmt;
end if;
-- Derive primitives inherited from the parent. Note that if the generic
-- actual is present, this is not really a type derivation, it is a
-- completion within an instance.
-- Case 1: Derived_Type does not implement interfaces
if not Is_Tagged_Type (Derived_Type)
or else (not Has_Interfaces (Derived_Type)
and then not (Present (Generic_Actual)
and then Has_Interfaces (Generic_Actual)))
then
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
-- Literals are derived earlier in the process of building the
-- derived type, and are skipped here.
if Ekind (Subp) = E_Enumeration_Literal then
null;
-- The actual is a direct descendant and the common primitive
-- operations appear in the same order.
-- If the generic parent type is present, the derived type is an
-- instance of a formal derived type, and within the instance its
-- operations are those of the actual. We derive from the formal
-- type but make the inherited operations aliases of the
-- corresponding operations of the actual.
else
pragma Assert (No (Node (Act_Elmt))
or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
and then
Type_Conformant
(Subp, Node (Act_Elmt),
Skip_Controlling_Formals => True)));
Derive_Subprogram
(New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
if Present (Act_Elmt) then
Next_Elmt (Act_Elmt);
end if;
end if;
Next_Elmt (Elmt);
end loop;
-- Case 2: Derived_Type implements interfaces
else
-- If the parent type has no predefined primitives we remove
-- predefined primitives from the list of primitives of generic
-- actual to simplify the complexity of this algorithm.
if Present (Generic_Actual) then
declare
Has_Predefined_Primitives : Boolean := False;
begin
-- Check if the parent type has predefined primitives
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
if Is_Predefined_Dispatching_Operation (Subp)
and then not Comes_From_Source (Ultimate_Alias (Subp))
then
Has_Predefined_Primitives := True;
exit;
end if;
Next_Elmt (Elmt);
end loop;
-- Remove predefined primitives of Generic_Actual. We must use
-- an auxiliary list because in case of tagged types the value
-- returned by Collect_Primitive_Operations is the value stored
-- in its Primitive_Operations attribute (and we don't want to
-- modify its current contents).
if not Has_Predefined_Primitives then
declare
Aux_List : constant Elist_Id := New_Elmt_List;
begin
Elmt := First_Elmt (Act_List);
while Present (Elmt) loop
Subp := Node (Elmt);
if not Is_Predefined_Dispatching_Operation (Subp)
or else Comes_From_Source (Subp)
then
Append_Elmt (Subp, Aux_List);
end if;
Next_Elmt (Elmt);
end loop;
Act_List := Aux_List;
end;
end if;
Act_Elmt := First_Elmt (Act_List);
Act_Subp := Node (Act_Elmt);
end;
end if;
-- Stage 1: If the generic actual is not present we derive the
-- primitives inherited from the parent type. If the generic parent
-- type is present, the derived type is an instance of a formal
-- derived type, and within the instance its operations are those of
-- the actual. We derive from the formal type but make the inherited
-- operations aliases of the corresponding operations of the actual.
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
Alias_Subp := Ultimate_Alias (Subp);
-- Do not derive internal entities of the parent that link
-- interface primitives with their covering primitive. These
-- entities will be added to this type when frozen.
if Present (Interface_Alias (Subp)) then
goto Continue;
end if;
-- If the generic actual is present find the corresponding
-- operation in the generic actual. If the parent type is a
-- direct ancestor of the derived type then, even if it is an
-- interface, the operations are inherited from the primary
-- dispatch table and are in the proper order. If we detect here
-- that primitives are not in the same order we traverse the list
-- of primitive operations of the actual to find the one that
-- implements the interface primitive.
if Need_Search
or else
(Present (Generic_Actual)
and then Present (Act_Subp)
and then not
(Primitive_Names_Match (Subp, Act_Subp)
and then
Type_Conformant (Subp, Act_Subp,
Skip_Controlling_Formals => True)))
then
pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
Use_Full_View => True));
-- Remember that we need searching for all pending primitives
Need_Search := True;
-- Handle entities associated with interface primitives
if Present (Alias_Subp)
and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
and then not Is_Predefined_Dispatching_Operation (Subp)
then
-- Search for the primitive in the homonym chain
Act_Subp :=
Find_Primitive_Covering_Interface
(Tagged_Type => Generic_Actual,
Iface_Prim => Alias_Subp);
-- Previous search may not locate primitives covering
-- interfaces defined in generics units or instantiations.
-- (it fails if the covering primitive has formals whose
-- type is also defined in generics or instantiations).
-- In such case we search in the list of primitives of the
-- generic actual for the internal entity that links the
-- interface primitive and the covering primitive.
if No (Act_Subp)
and then Is_Generic_Type (Parent_Type)
then
-- This code has been designed to handle only generic
-- formals that implement interfaces that are defined
-- in a generic unit or instantiation. If this code is
-- needed for other cases we must review it because
-- (given that it relies on Original_Location to locate
-- the primitive of Generic_Actual that covers the
-- interface) it could leave linked through attribute
-- Alias entities of unrelated instantiations).
pragma Assert
(Is_Generic_Unit
(Scope (Find_Dispatching_Type (Alias_Subp)))
or else
Instantiation_Location
(Sloc (Find_Dispatching_Type (Alias_Subp)))
/= No_Location);
declare
Iface_Prim_Loc : constant Source_Ptr :=
Original_Location (Sloc (Alias_Subp));
Elmt : Elmt_Id;
Prim : Entity_Id;
begin
Elmt :=
First_Elmt (Primitive_Operations (Generic_Actual));
Search : while Present (Elmt) loop
Prim := Node (Elmt);
if Present (Interface_Alias (Prim))
and then Original_Location
(Sloc (Interface_Alias (Prim))) =
Iface_Prim_Loc
then
Act_Subp := Alias (Prim);
exit Search;
end if;
Next_Elmt (Elmt);
end loop Search;
end;
end if;
pragma Assert (Present (Act_Subp)
or else Is_Abstract_Type (Generic_Actual)
or else Serious_Errors_Detected > 0);
-- Handle predefined primitives plus the rest of user-defined
-- primitives
else
Act_Elmt := First_Elmt (Act_List);
while Present (Act_Elmt) loop
Act_Subp := Node (Act_Elmt);
exit when Primitive_Names_Match (Subp, Act_Subp)
and then Type_Conformant
(Subp, Act_Subp,
Skip_Controlling_Formals => True)
and then No (Interface_Alias (Act_Subp));
Next_Elmt (Act_Elmt);
end loop;
if No (Act_Elmt) then
Act_Subp := Empty;
end if;
end if;
end if;
-- Case 1: If the parent is a limited interface then it has the
-- predefined primitives of synchronized interfaces. However, the
-- actual type may be a non-limited type and hence it does not
-- have such primitives.
if Present (Generic_Actual)
and then No (Act_Subp)
and then Is_Limited_Interface (Parent_Base)
and then Is_Predefined_Interface_Primitive (Subp)
then
null;
-- Case 2: Inherit entities associated with interfaces that were
-- not covered by the parent type. We exclude here null interface
-- primitives because they do not need special management.
-- We also exclude interface operations that are renamings. If the
-- subprogram is an explicit renaming of an interface primitive,
-- it is a regular primitive operation, and the presence of its
-- alias is not relevant: it has to be derived like any other
-- primitive.
elsif Present (Alias (Subp))
and then Nkind (Unit_Declaration_Node (Subp)) /=
N_Subprogram_Renaming_Declaration
and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
and then not
(Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
and then Null_Present (Parent (Alias_Subp)))
then
-- If this is an abstract private type then we transfer the
-- derivation of the interface primitive from the partial view
-- to the full view. This is safe because all the interfaces
-- must be visible in the partial view. Done to avoid adding
-- a new interface derivation to the private part of the
-- enclosing package; otherwise this new derivation would be
-- decorated as hidden when the analysis of the enclosing
-- package completes.
if Is_Abstract_Type (Derived_Type)
and then In_Private_Part (Current_Scope)
and then Has_Private_Declaration (Derived_Type)
then
declare
Partial_View : Entity_Id;
Elmt : Elmt_Id;
Ent : Entity_Id;
begin
Partial_View := First_Entity (Current_Scope);
loop
exit when No (Partial_View)
or else (Has_Private_Declaration (Partial_View)
and then
Full_View (Partial_View) = Derived_Type);
Next_Entity (Partial_View);
end loop;
-- If the partial view was not found then the source code
-- has errors and the derivation is not needed.
if Present (Partial_View) then
Elmt :=
First_Elmt (Primitive_Operations (Partial_View));
while Present (Elmt) loop
Ent := Node (Elmt);
if Present (Alias (Ent))
and then Ultimate_Alias (Ent) = Alias (Subp)
then
Append_Elmt
(Ent, Primitive_Operations (Derived_Type));
exit;
end if;
Next_Elmt (Elmt);
end loop;
-- If the interface primitive was not found in the
-- partial view then this interface primitive was
-- overridden. We add a derivation to activate in
-- Derive_Progenitor_Subprograms the machinery to
-- search for it.
if No (Elmt) then
Derive_Interface_Subprogram
(New_Subp => New_Subp,
Subp => Subp,
Actual_Subp => Act_Subp);
end if;
end if;
end;
else
Derive_Interface_Subprogram
(New_Subp => New_Subp,
Subp => Subp,
Actual_Subp => Act_Subp);
end if;
-- Case 3: Common derivation
else
Derive_Subprogram
(New_Subp => New_Subp,
Parent_Subp => Subp,
Derived_Type => Derived_Type,
Parent_Type => Parent_Base,
Actual_Subp => Act_Subp);
end if;
-- No need to update Act_Elm if we must search for the
-- corresponding operation in the generic actual
if not Need_Search
and then Present (Act_Elmt)
then
Next_Elmt (Act_Elmt);
Act_Subp := Node (Act_Elmt);
end if;
<<Continue>>
Next_Elmt (Elmt);
end loop;
-- Inherit additional operations from progenitors. If the derived
-- type is a generic actual, there are not new primitive operations
-- for the type because it has those of the actual, and therefore
-- nothing needs to be done. The renamings generated above are not
-- primitive operations, and their purpose is simply to make the
-- proper operations visible within an instantiation.
if No (Generic_Actual) then
Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
end if;
end if;
-- Final check: Direct descendants must have their primitives in the
-- same order. We exclude from this test untagged types and instances
-- of formal derived types. We skip this test if we have already
-- reported serious errors in the sources.
pragma Assert (not Is_Tagged_Type (Derived_Type)
or else Present (Generic_Actual)
or else Serious_Errors_Detected > 0
or else Check_Derived_Type);
end Derive_Subprograms;
--------------------------------
-- Derived_Standard_Character --
--------------------------------
procedure Derived_Standard_Character
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : constant Entity_Id :=
Create_Itype
(E_Enumeration_Type, N, Derived_Type, 'B');
Lo : Node_Id;
Hi : Node_Id;
begin
Discard_Node (Process_Subtype (Indic, N));
Set_Etype (Implicit_Base, Parent_Base);
Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
Set_Is_Character_Type (Implicit_Base, True);
Set_Has_Delayed_Freeze (Implicit_Base);
-- The bounds of the implicit base are the bounds of the parent base.
-- Note that their type is the parent base.
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
Mutate_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Set_Size_Info (Derived_Type, Parent_Type);
if not Known_RM_Size (Derived_Type) then
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
end if;
Set_Is_Character_Type (Derived_Type, True);
if Nkind (Indic) /= N_Subtype_Indication then
-- If no explicit constraint, the bounds are those
-- of the parent type.
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
end if;
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
end Derived_Standard_Character;
------------------------------
-- Derived_Type_Declaration --
------------------------------
procedure Derived_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Is_Completion : Boolean)
is
Parent_Type : Entity_Id;
function Comes_From_Generic (Typ : Entity_Id) return Boolean;
-- Check whether the parent type is a generic formal, or derives
-- directly or indirectly from one.
------------------------
-- Comes_From_Generic --
------------------------
function Comes_From_Generic (Typ : Entity_Id) return Boolean is
begin
if Is_Generic_Type (Typ) then
return True;
elsif Is_Generic_Type (Root_Type (Parent_Type)) then
return True;
elsif Is_Private_Type (Typ)
and then Present (Full_View (Typ))
and then Is_Generic_Type (Root_Type (Full_View (Typ)))
then
return True;
elsif Is_Generic_Actual_Type (Typ) then
return True;
else
return False;
end if;
end Comes_From_Generic;
-- Local variables
Def : constant Node_Id := Type_Definition (N);
Iface_Def : Node_Id;
Indic : constant Node_Id := Subtype_Indication (Def);
Extension : constant Node_Id := Record_Extension_Part (Def);
Parent_Node : Node_Id;
Taggd : Boolean;
-- Start of processing for Derived_Type_Declaration
begin
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
if SPARK_Mode = On
and then Is_Tagged_Type (Parent_Type)
then
declare
Partial_View : constant Entity_Id :=
Incomplete_Or_Partial_View (Parent_Type);
begin
-- If the partial view was not found then the parent type is not
-- a private type. Otherwise check if the partial view is a tagged
-- private type.
if Present (Partial_View)
and then Is_Private_Type (Partial_View)
and then not Is_Tagged_Type (Partial_View)
then
Error_Msg_NE
("cannot derive from & declared as untagged private "
& "(SPARK RM 3.4(1))", N, Partial_View);
end if;
end;
end if;
-- Ada 2005 (AI-251): In case of interface derivation check that the
-- parent is also an interface.
if Interface_Present (Def) then
if not Is_Interface (Parent_Type) then
Diagnose_Interface (Indic, Parent_Type);
else
Parent_Node := Parent (Base_Type (Parent_Type));
Iface_Def := Type_Definition (Parent_Node);
-- Ada 2005 (AI-251): Limited interfaces can only inherit from
-- other limited interfaces.
if Limited_Present (Def) then
if Limited_Present (Iface_Def) then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a protected "
& "interface", N, Parent_Type);
elsif Synchronized_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a synchronized "
& "interface", N, Parent_Type);
elsif Task_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a task interface",
N, Parent_Type);
else
Error_Msg_N
("(Ada 2005) limited interface cannot inherit from "
& "non-limited interface", Indic);
end if;
-- Ada 2005 (AI-345): Non-limited interfaces can only inherit
-- from non-limited or limited interfaces.
elsif not Protected_Present (Def)
and then not Synchronized_Present (Def)
and then not Task_Present (Def)
then
if Limited_Present (Iface_Def) then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a protected "
& "interface", N, Parent_Type);
elsif Synchronized_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a synchronized "
& "interface", N, Parent_Type);
elsif Task_Present (Iface_Def) then
Error_Msg_NE
("descendant of & must be declared as a task interface",
N, Parent_Type);
else
null;
end if;
end if;
end if;
end if;
if Is_Tagged_Type (Parent_Type)
and then Is_Concurrent_Type (Parent_Type)
and then not Is_Interface (Parent_Type)
then
Error_Msg_N
("parent type of a record extension cannot be a synchronized "
& "tagged type (RM 3.9.1 (3/1))", N);
Set_Etype (T, Any_Type);
return;
end if;
-- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
-- interfaces
if Is_Tagged_Type (Parent_Type)
and then Is_Non_Empty_List (Interface_List (Def))
then
declare
Intf : Node_Id;
T : Entity_Id;
begin
Intf := First (Interface_List (Def));
while Present (Intf) loop
T := Find_Type_Of_Subtype_Indic (Intf);
if not Is_Interface (T) then
Diagnose_Interface (Intf, T);
-- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
-- a limited type from having a nonlimited progenitor.
elsif (Limited_Present (Def)
or else (not Is_Interface (Parent_Type)
and then Is_Limited_Type (Parent_Type)))
and then not Is_Limited_Interface (T)
then
Error_Msg_NE
("progenitor interface& of limited type must be limited",
N, T);
end if;
Next (Intf);
end loop;
end;
-- Check consistency of any nonoverridable aspects that are
-- inherited from multiple sources.
Check_Inherited_Nonoverridable_Aspects
(Inheritor => T,
Interface_List => Interface_List (Def),
Parent_Type => Parent_Type);
end if;
if Parent_Type = Any_Type
or else Etype (Parent_Type) = Any_Type
or else (Is_Class_Wide_Type (Parent_Type)
and then Etype (Parent_Type) = T)
then
-- If Parent_Type is undefined or illegal, make new type into a
-- subtype of Any_Type, and set a few attributes to prevent cascaded
-- errors. If this is a self-definition, emit error now.
if T = Parent_Type or else T = Etype (Parent_Type) then
Error_Msg_N ("type cannot be used in its own definition", Indic);
end if;
Mutate_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
Set_Scalar_Range (T, Scalar_Range (Any_Type));
-- Initialize the list of primitive operations to an empty list,
-- to cover tagged types as well as untagged types. For untagged
-- types this is used either to analyze the call as legal when
-- Extensions_Allowed is True, or to issue a better error message
-- otherwise.
Set_Direct_Primitive_Operations (T, New_Elmt_List);
return;
end if;
-- Ada 2005 (AI-251): The case in which the parent of the full-view is
-- an interface is special because the list of interfaces in the full
-- view can be given in any order. For example:
-- type A is interface;
-- type B is interface and A;
-- type D is new B with private;
-- private
-- type D is new A and B with null record; -- 1 --
-- In this case we perform the following transformation of -1-:
-- type D is new B and A with null record;
-- If the parent of the full-view covers the parent of the partial-view
-- we have two possible cases:
-- 1) They have the same parent
-- 2) The parent of the full-view implements some further interfaces
-- In both cases we do not need to perform the transformation. In the
-- first case the source program is correct and the transformation is
-- not needed; in the second case the source program does not fulfill
-- the no-hidden interfaces rule (AI-396) and the error will be reported
-- later.
-- This transformation not only simplifies the rest of the analysis of
-- this type declaration but also simplifies the correct generation of
-- the object layout to the expander.
if In_Private_Part (Current_Scope)
and then Is_Interface (Parent_Type)
then
declare
Partial_View : Entity_Id;
Partial_View_Parent : Entity_Id;
function Reorder_Interfaces return Boolean;
-- Look for an interface in the full view's interface list that
-- matches the parent type of the partial view, and when found,
-- rewrite the full view's parent with the partial view's parent,
-- append the full view's original parent to the interface list,
-- recursively call Derived_Type_Definition on the full type, and
-- return True. If a match is not found, return False.
------------------------
-- Reorder_Interfaces --
------------------------
function Reorder_Interfaces return Boolean is
Iface : Node_Id;
New_Iface : Node_Id;
begin
Iface := First (Interface_List (Def));
while Present (Iface) loop
if Etype (Iface) = Etype (Partial_View) then
Rewrite (Subtype_Indication (Def),
New_Copy (Subtype_Indication (Parent (Partial_View))));
New_Iface :=
Make_Identifier (Sloc (N), Chars (Parent_Type));
Rewrite (Iface, New_Iface);
-- Analyze the transformed code
Derived_Type_Declaration (T, N, Is_Completion);
return True;
end if;
Next (Iface);
end loop;
return False;
end Reorder_Interfaces;
begin
-- Look for the associated private type declaration
Partial_View := Incomplete_Or_Partial_View (T);
-- If the partial view was not found then the source code has
-- errors and the transformation is not needed.
if Present (Partial_View) then
Partial_View_Parent := Etype (Partial_View);
-- If the parent of the full-view covers the parent of the
-- partial-view we have nothing else to do.
if Interface_Present_In_Ancestor
(Parent_Type, Partial_View_Parent)
then
null;
-- Traverse the list of interfaces of the full view to look
-- for the parent of the partial view and reorder the
-- interfaces to match the order in the partial view,
-- if needed.
else
if Reorder_Interfaces then
-- Having the interfaces listed in any order is legal.
-- However, the compiler does not properly handle
-- different orders between partial and full views in
-- generic units. We give a warning about the order
-- mismatch, so the user can work around this problem.
Error_Msg_N ("??full declaration does not respect " &
"partial declaration order", T);
Error_Msg_N ("\??consider reordering", T);
return;
end if;
end if;
end if;
end;
end if;
-- Only composite types other than array types are allowed to have
-- discriminants.
if Present (Discriminant_Specifications (N)) then
if (Is_Elementary_Type (Parent_Type)
or else
Is_Array_Type (Parent_Type))
and then not Error_Posted (N)
then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier (First (Discriminant_Specifications (N))));
-- Unset Has_Discriminants flag to prevent cascaded errors, but
-- only if we are not already processing a malformed syntax tree.
if Is_Type (T) then
Set_Has_Discriminants (T, False);
end if;
end if;
end if;
-- In Ada 83, a derived type defined in a package specification cannot
-- be used for further derivation until the end of its visible part.
-- Note that derivation in the private part of the package is allowed.
if Ada_Version = Ada_83
and then Is_Derived_Type (Parent_Type)
and then In_Visible_Part (Scope (Parent_Type))
then
if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
Error_Msg_N
("(Ada 83) premature use of type for derivation", Indic);
end if;
end if;
-- Check for early use of incomplete or private type
if Ekind (Parent_Type) in E_Void | E_Incomplete_Type then
Error_Msg_N ("premature derivation of incomplete type", Indic);
return;
elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
and then not Comes_From_Generic (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
-- The ancestor type of a formal type can be incomplete, in which
-- case only the operations of the partial view are available in the
-- generic. Subsequent checks may be required when the full view is
-- analyzed to verify that a derivation from a tagged type has an
-- extension.
if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
null;
elsif No (Underlying_Type (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
Error_Msg_N
("premature derivation of derived or private type", Indic);
-- Flag the type itself as being in error, this prevents some
-- nasty problems with subsequent uses of the malformed type.
Set_Error_Posted (T);
-- Check that within the immediate scope of an untagged partial
-- view it's illegal to derive from the partial view if the
-- full view is tagged. (7.3(7))
-- We verify that the Parent_Type is a partial view by checking
-- that it is not a Full_Type_Declaration (i.e. a private type or
-- private extension declaration), to distinguish a partial view
-- from a derivation from a private type which also appears as
-- E_Private_Type. If the parent base type is not declared in an
-- enclosing scope there is no need to check.
elsif Present (Full_View (Parent_Type))
and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
and then not Is_Tagged_Type (Parent_Type)
and then Is_Tagged_Type (Full_View (Parent_Type))
and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
then
Error_Msg_N
("premature derivation from type with tagged full view",
Indic);
end if;
end if;
-- Check that form of derivation is appropriate
Taggd := Is_Tagged_Type (Parent_Type);
-- Set the parent type to the class-wide type's specific type in this
-- case to prevent cascading errors
if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N ("parent type must not be a class-wide type", Indic);
Set_Etype (T, Etype (Parent_Type));
return;
end if;
if Present (Extension) and then not Taggd then
Error_Msg_N
("type derived from untagged type cannot have extension", Indic);
elsif No (Extension) and then Taggd then
-- If this declaration is within a private part (or body) of a
-- generic instantiation then the derivation is allowed (the parent
-- type can only appear tagged in this case if it's a generic actual
-- type, since it would otherwise have been rejected in the analysis
-- of the generic template).
if not Is_Generic_Actual_Type (Parent_Type)
or else In_Visible_Part (Scope (Parent_Type))
then
if Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N
("parent type must not be a class-wide type", Indic);
-- Use specific type to prevent cascaded errors.
Parent_Type := Etype (Parent_Type);
else
Error_Msg_N
("type derived from tagged type must have extension", Indic);
end if;
end if;
end if;
-- AI-443: Synchronized formal derived types require a private
-- extension. There is no point in checking the ancestor type or
-- the progenitors since the construct is wrong to begin with.
if Ada_Version >= Ada_2005
and then Is_Generic_Type (T)
and then Present (Original_Node (N))
then
declare
Decl : constant Node_Id := Original_Node (N);
begin
if Nkind (Decl) = N_Formal_Type_Declaration
and then Nkind (Formal_Type_Definition (Decl)) =
N_Formal_Derived_Type_Definition
and then Synchronized_Present (Formal_Type_Definition (Decl))
and then No (Extension)
-- Avoid emitting a duplicate error message
and then not Error_Posted (Indic)
then
Error_Msg_N
("synchronized derived type must have extension", N);
end if;
end;
end if;
if Null_Exclusion_Present (Def)
and then not Is_Access_Type (Parent_Type)
then
Error_Msg_N ("null exclusion can only apply to an access type", N);
end if;
Check_Wide_Character_Restriction (Parent_Type, Indic);
-- Avoid deriving parent primitives of underlying record views
Build_Derived_Type (N, Parent_Type, T, Is_Completion,
Derive_Subps => not Is_Underlying_Record_View (T));
-- AI-419: The parent type of an explicitly limited derived type must
-- be a limited type or a limited interface.
if Limited_Present (Def) then
Set_Is_Limited_Record (T);
if Is_Interface (T) then
Set_Is_Limited_Interface (T);
end if;
if not Is_Limited_Type (Parent_Type)
and then
(not Is_Interface (Parent_Type)
or else not Is_Limited_Interface (Parent_Type))
then
-- AI05-0096: a derivation in the private part of an instance is
-- legal if the generic formal is untagged limited, and the actual
-- is non-limited.
if Is_Generic_Actual_Type (Parent_Type)
and then In_Private_Part (Current_Scope)
and then
not Is_Tagged_Type
(Generic_Parent_Type (Parent (Parent_Type)))
then
null;
else
Error_Msg_NE
("parent type& of limited type must be limited",
N, Parent_Type);
end if;
end if;
end if;
end Derived_Type_Declaration;
------------------------
-- Diagnose_Interface --
------------------------
procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
begin
if not Is_Interface (E) and then E /= Any_Type then
Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
end if;
end Diagnose_Interface;
----------------------------------
-- Enumeration_Type_Declaration --
----------------------------------
procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Ev : Uint;
L : Node_Id;
R_Node : Node_Id;
B_Node : Node_Id;
begin
-- Create identifier node representing lower bound
B_Node := New_Node (N_Identifier, Sloc (Def));
L := First (Literals (Def));
Set_Chars (B_Node, Chars (L));
Set_Entity (B_Node, L);
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
R_Node := New_Node (N_Range, Sloc (Def));
Set_Low_Bound (R_Node, B_Node);
Mutate_Ekind (T, E_Enumeration_Type);
Set_First_Literal (T, L);
Set_Etype (T, T);
Set_Is_Constrained (T);
Ev := Uint_0;
-- Loop through literals of enumeration type setting pos and rep values
-- except that if the Ekind is already set, then it means the literal
-- was already constructed (case of a derived type declaration and we
-- should not disturb the Pos and Rep values.
while Present (L) loop
if Ekind (L) /= E_Enumeration_Literal then
Mutate_Ekind (L, E_Enumeration_Literal);
Set_Enumeration_Pos (L, Ev);
Set_Enumeration_Rep (L, Ev);
Set_Is_Known_Valid (L, True);
end if;
Set_Etype (L, T);
New_Overloaded_Entity (L);
Generate_Definition (L);
Set_Convention (L, Convention_Intrinsic);
-- Case of character literal
if Nkind (L) = N_Defining_Character_Literal then
Set_Is_Character_Type (T, True);
-- Check violation of No_Wide_Characters
if Restriction_Check_Required (No_Wide_Characters) then
Get_Name_String (Chars (L));
if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
Check_Restriction (No_Wide_Characters, L);
end if;
end if;
end if;
Ev := Ev + 1;
Next (L);
end loop;
-- Now create a node representing upper bound
B_Node := New_Node (N_Identifier, Sloc (Def));
Set_Chars (B_Node, Chars (Last (Literals (Def))));
Set_Entity (B_Node, Last (Literals (Def)));
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
Set_High_Bound (R_Node, B_Node);
-- Initialize various fields of the type. Some of this information
-- may be overwritten later through rep. clauses.
Set_Scalar_Range (T, R_Node);
Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
Set_Enum_Esize (T);
Set_Enum_Pos_To_Rep (T, Empty);
-- Set Discard_Names if configuration pragma set, or if there is
-- a parameterless pragma in the current declarative region
if Global_Discard_Names or else Discard_Names (Scope (T)) then
Set_Discard_Names (T);
end if;
-- Process end label if there is one
if Present (Def) then
Process_End_Label (Def, 'e', T);
end if;
end Enumeration_Type_Declaration;
---------------------------------
-- Expand_To_Stored_Constraint --
---------------------------------
function Expand_To_Stored_Constraint
(Typ : Entity_Id;
Constraint : Elist_Id) return Elist_Id
is
Explicitly_Discriminated_Type : Entity_Id;
Expansion : Elist_Id;
Discriminant : Entity_Id;
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
-- Find the nearest type that actually specifies discriminants
---------------------------------
-- Type_With_Explicit_Discrims --
---------------------------------
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
Typ : constant E := Base_Type (Id);
begin
if Ekind (Typ) in Incomplete_Or_Private_Kind then
if Present (Full_View (Typ)) then
return Type_With_Explicit_Discrims (Full_View (Typ));
end if;
else
if Has_Discriminants (Typ) then
return Typ;
end if;
end if;
if Etype (Typ) = Typ then
return Empty;
elsif Has_Discriminants (Typ) then
return Typ;
else
return Type_With_Explicit_Discrims (Etype (Typ));
end if;
end Type_With_Explicit_Discrims;
-- Start of processing for Expand_To_Stored_Constraint
begin
if No (Constraint) or else Is_Empty_Elmt_List (Constraint) then
return No_Elist;
end if;
Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
if No (Explicitly_Discriminated_Type) then
return No_Elist;
end if;
Expansion := New_Elmt_List;
Discriminant :=
First_Stored_Discriminant (Explicitly_Discriminated_Type);
while Present (Discriminant) loop
Append_Elmt
(Get_Discriminant_Value
(Discriminant, Explicitly_Discriminated_Type, Constraint),
To => Expansion);
Next_Stored_Discriminant (Discriminant);
end loop;
return Expansion;
end Expand_To_Stored_Constraint;
---------------------------
-- Find_Hidden_Interface --
---------------------------
function Find_Hidden_Interface
(Src : Elist_Id;
Dest : Elist_Id) return Entity_Id
is
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
begin
if Present (Src) and then Present (Dest) then
Iface_Elmt := First_Elmt (Src);
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
if Is_Interface (Iface)
and then not Contain_Interface (Iface, Dest)
then
return Iface;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
return Empty;
end Find_Hidden_Interface;
--------------------
-- Find_Type_Name --
--------------------
function Find_Type_Name (N : Node_Id) return Entity_Id is
Id : constant Entity_Id := Defining_Identifier (N);
New_Id : Entity_Id;
Prev : Entity_Id;
Prev_Par : Node_Id;
procedure Check_Duplicate_Aspects;
-- Check that aspects specified in a completion have not been specified
-- already in the partial view.
procedure Tag_Mismatch;
-- Diagnose a tagged partial view whose full view is untagged. We post
-- the message on the full view, with a reference to the previous
-- partial view. The partial view can be private or incomplete, and
-- these are handled in a different manner, so we determine the position
-- of the error message from the respective slocs of both.
-----------------------------
-- Check_Duplicate_Aspects --
-----------------------------
procedure Check_Duplicate_Aspects is
function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id;
-- Return the corresponding aspect of the partial view which matches
-- the aspect id of Asp. Return Empty is no such aspect exists.
-----------------------------
-- Get_Partial_View_Aspect --
-----------------------------
function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id is
Asp_Id : constant Aspect_Id := Get_Aspect_Id (Asp);
Prev_Asps : constant List_Id := Aspect_Specifications (Prev_Par);
Prev_Asp : Node_Id;
begin
if Present (Prev_Asps) then
Prev_Asp := First (Prev_Asps);
while Present (Prev_Asp) loop
if Get_Aspect_Id (Prev_Asp) = Asp_Id then
return Prev_Asp;
end if;
Next (Prev_Asp);
end loop;
end if;
return Empty;
end Get_Partial_View_Aspect;
-- Local variables
Full_Asps : constant List_Id := Aspect_Specifications (N);
Full_Asp : Node_Id;
Part_Asp : Node_Id;
-- Start of processing for Check_Duplicate_Aspects
begin
if Present (Full_Asps) then
Full_Asp := First (Full_Asps);
while Present (Full_Asp) loop
Part_Asp := Get_Partial_View_Aspect (Full_Asp);
-- An aspect and its class-wide counterpart are two distinct
-- aspects and may apply to both views of an entity.
if Present (Part_Asp)
and then Class_Present (Part_Asp) = Class_Present (Full_Asp)
then
Error_Msg_N
("aspect already specified in private declaration",
Full_Asp);
Remove (Full_Asp);
return;
end if;
if Has_Discriminants (Prev)
and then not Has_Unknown_Discriminants (Prev)
and then Get_Aspect_Id (Full_Asp) =
Aspect_Implicit_Dereference
then
Error_Msg_N
("cannot specify aspect if partial view has known "
& "discriminants", Full_Asp);
end if;
Next (Full_Asp);
end loop;
end if;
end Check_Duplicate_Aspects;
------------------
-- Tag_Mismatch --
------------------
procedure Tag_Mismatch is
begin
if Sloc (Prev) < Sloc (Id) then
if Ada_Version >= Ada_2012
and then Nkind (N) = N_Private_Type_Declaration
then
Error_Msg_NE
("declaration of private } must be a tagged type", Id, Prev);
else
Error_Msg_NE
("full declaration of } must be a tagged type", Id, Prev);
end if;
else
if Ada_Version >= Ada_2012
and then Nkind (N) = N_Private_Type_Declaration
then
Error_Msg_NE
("declaration of private } must be a tagged type", Prev, Id);
else
Error_Msg_NE
("full declaration of } must be a tagged type", Prev, Id);
end if;
end if;
end Tag_Mismatch;
-- Start of processing for Find_Type_Name
begin
-- Find incomplete declaration, if one was given
Prev := Current_Entity_In_Scope (Id);
-- New type declaration
if No (Prev) then
Enter_Name (Id);
return Id;
-- Previous declaration exists
else
Prev_Par := Parent (Prev);
-- Error if not incomplete/private case except if previous
-- declaration is implicit, etc. Enter_Name will emit error if
-- appropriate.
if not Is_Incomplete_Or_Private_Type (Prev) then
Enter_Name (Id);
New_Id := Id;
-- Check invalid completion of private or incomplete type
elsif Nkind (N) not in N_Full_Type_Declaration
| N_Task_Type_Declaration
| N_Protected_Type_Declaration
and then
(Ada_Version < Ada_2012
or else not Is_Incomplete_Type (Prev)
or else Nkind (N) not in N_Private_Type_Declaration
| N_Private_Extension_Declaration)
then
-- Completion must be a full type declarations (RM 7.3(4))
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_NE ("invalid completion of }", Id, Prev);
-- Set scope of Id to avoid cascaded errors. Entity is never
-- examined again, except when saving globals in generics.
Set_Scope (Id, Current_Scope);
New_Id := Id;
-- If this is a repeated incomplete declaration, no further
-- checks are possible.
if Nkind (N) = N_Incomplete_Type_Declaration then
return Prev;
end if;
-- Case of full declaration of incomplete type
elsif Ekind (Prev) = E_Incomplete_Type
and then (Ada_Version < Ada_2012
or else No (Full_View (Prev))
or else not Is_Private_Type (Full_View (Prev)))
then
-- Indicate that the incomplete declaration has a matching full
-- declaration. The defining occurrence of the incomplete
-- declaration remains the visible one, and the procedure
-- Get_Full_View dereferences it whenever the type is used.
if Present (Full_View (Prev)) then
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
end if;
Set_Full_View (Prev, Id);
Append_Entity (Id, Current_Scope);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
New_Id := Prev;
-- If the incomplete view is tagged, a class_wide type has been
-- created already. Use it for the private type as well, in order
-- to prevent multiple incompatible class-wide types that may be
-- created for self-referential anonymous access components.
if Is_Tagged_Type (Prev)
and then Present (Class_Wide_Type (Prev))
then
Mutate_Ekind (Id, Ekind (Prev)); -- will be reset later
Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
-- Type of the class-wide type is the current Id. Previously
-- this was not done for private declarations because of order-
-- of-elaboration issues in the back end, but gigi now handles
-- this properly.
Set_Etype (Class_Wide_Type (Id), Id);
end if;
-- Case of full declaration of private type
else
-- If the private type was a completion of an incomplete type then
-- update Prev to reference the private type
if Ada_Version >= Ada_2012
and then Ekind (Prev) = E_Incomplete_Type
and then Present (Full_View (Prev))
and then Is_Private_Type (Full_View (Prev))
then
Prev := Full_View (Prev);
Prev_Par := Parent (Prev);
end if;
if Nkind (N) = N_Full_Type_Declaration
and then Nkind (Type_Definition (N)) in
N_Record_Definition | N_Derived_Type_Definition
and then Interface_Present (Type_Definition (N))
then
Error_Msg_N
("completion of private type cannot be an interface", N);
end if;
if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
if Etype (Prev) /= Prev then
-- Prev is a private subtype or a derived type, and needs
-- no completion.
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
New_Id := Id;
elsif Ekind (Prev) = E_Private_Type
and then Nkind (N) in N_Task_Type_Declaration
| N_Protected_Type_Declaration
then
Error_Msg_N
("completion of nonlimited type cannot be limited", N);
elsif Ekind (Prev) = E_Record_Type_With_Private
and then Nkind (N) in N_Task_Type_Declaration
| N_Protected_Type_Declaration
then
if not Is_Limited_Record (Prev) then
Error_Msg_N
("completion of nonlimited type cannot be limited", N);
elsif No (Interface_List (N)) then
Error_Msg_N
("completion of tagged private type must be tagged",
N);
end if;
end if;
-- Ada 2005 (AI-251): Private extension declaration of a task
-- type or a protected type. This case arises when covering
-- interface types.
elsif Nkind (N) in N_Task_Type_Declaration
| N_Protected_Type_Declaration
then
null;
elsif Nkind (N) /= N_Full_Type_Declaration
or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
then
Error_Msg_N
("full view of private extension must be an extension", N);
elsif not (Abstract_Present (Parent (Prev)))
and then Abstract_Present (Type_Definition (N))
then
Error_Msg_N
("full view of non-abstract extension cannot be abstract", N);
end if;
if not In_Private_Part (Current_Scope) then
Error_Msg_N
("declaration of full view must appear in private part", N);
end if;
if Ada_Version >= Ada_2012 then
Check_Duplicate_Aspects;
end if;
Copy_And_Swap (Prev, Id);
Set_Has_Private_Declaration (Prev);
Set_Has_Private_Declaration (Id);
-- AI12-0133: Indicate whether we have a partial view with
-- unknown discriminants, in which case initialization of objects
-- of the type do not receive an invariant check.
Set_Partial_View_Has_Unknown_Discr
(Prev, Has_Unknown_Discriminants (Id));
-- Preserve aspect and iterator flags that may have been set on
-- the partial view.
Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id));
-- If no error, propagate freeze_node from private to full view.
-- It may have been generated for an early operational item.
if Present (Freeze_Node (Id))
and then Serious_Errors_Detected = 0
and then No (Full_View (Id))
then
Set_Freeze_Node (Prev, Freeze_Node (Id));
Set_Freeze_Node (Id, Empty);
Set_First_Rep_Item (Prev, First_Rep_Item (Id));
end if;
Set_Full_View (Id, Prev);
New_Id := Prev;
end if;
-- Verify that full declaration conforms to partial one
if Is_Incomplete_Or_Private_Type (Prev)
and then Present (Discriminant_Specifications (Prev_Par))
then
if Present (Discriminant_Specifications (N)) then
if Ekind (Prev) = E_Incomplete_Type then
Check_Discriminant_Conformance (N, Prev, Prev);
else
Check_Discriminant_Conformance (N, Prev, Id);
end if;
else
Error_Msg_N
("missing discriminants in full type declaration", N);
-- To avoid cascaded errors on subsequent use, share the
-- discriminants of the partial view.
Set_Discriminant_Specifications (N,
Discriminant_Specifications (Prev_Par));
end if;
end if;
-- A prior untagged partial view can have an associated class-wide
-- type due to use of the class attribute, and in this case the full
-- type must also be tagged. This Ada 95 usage is deprecated in favor
-- of incomplete tagged declarations, but we check for it.
if Is_Type (Prev)
and then (Is_Tagged_Type (Prev)
or else Present (Class_Wide_Type (Prev)))
then
-- Ada 2012 (AI05-0162): A private type may be the completion of
-- an incomplete type.
if Ada_Version >= Ada_2012
and then Is_Incomplete_Type (Prev)
and then Nkind (N) in N_Private_Type_Declaration
| N_Private_Extension_Declaration
then
-- No need to check private extensions since they are tagged
if Nkind (N) = N_Private_Type_Declaration
and then not Tagged_Present (N)
then
Tag_Mismatch;
end if;
-- The full declaration is either a tagged type (including
-- a synchronized type that implements interfaces) or a
-- type extension, otherwise this is an error.
elsif Nkind (N) in N_Task_Type_Declaration
| N_Protected_Type_Declaration
then
if No (Interface_List (N)) and then not Error_Posted (N) then
Tag_Mismatch;
end if;
elsif Nkind (Type_Definition (N)) = N_Record_Definition then
-- Indicate that the previous declaration (tagged incomplete
-- or private declaration) requires the same on the full one.
if not Tagged_Present (Type_Definition (N)) then
Tag_Mismatch;
Set_Is_Tagged_Type (Id);
end if;
elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
if No (Record_Extension_Part (Type_Definition (N))) then
Error_Msg_NE
("full declaration of } must be a record extension",
Prev, Id);
-- Set some attributes to produce a usable full view
Set_Is_Tagged_Type (Id);
end if;
else
Tag_Mismatch;
end if;
end if;
if Present (Prev)
and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
and then Present (Premature_Use (Parent (Prev)))
then
Error_Msg_Sloc := Sloc (N);
Error_Msg_N
("\full declaration #", Premature_Use (Parent (Prev)));
end if;
return New_Id;
end if;
end Find_Type_Name;
-------------------------
-- Find_Type_Of_Object --
-------------------------
function Find_Type_Of_Object
(Obj_Def : Node_Id;
Related_Nod : Node_Id) return Entity_Id
is
Def_Kind : constant Node_Kind := Nkind (Obj_Def);
P : Node_Id := Parent (Obj_Def);
T : Entity_Id;
Nam : Name_Id;
begin
-- If the parent is a component_definition node we climb to the
-- component_declaration node.
if Nkind (P) = N_Component_Definition then
P := Parent (P);
end if;
-- Case of an anonymous array subtype
if Def_Kind in N_Array_Type_Definition then
T := Empty;
Array_Type_Declaration (T, Obj_Def);
-- Create an explicit subtype whenever possible
elsif Nkind (P) /= N_Component_Declaration
and then Def_Kind = N_Subtype_Indication
then
-- Base name of subtype on object name, which will be unique in
-- the current scope.
-- If this is a duplicate declaration, return base type, to avoid
-- generating duplicate anonymous types.
if Error_Posted (P) then
Analyze (Subtype_Mark (Obj_Def));
return Entity (Subtype_Mark (Obj_Def));
end if;
Nam :=
New_External_Name
(Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
T := Make_Defining_Identifier (Sloc (P), Nam);
-- If In_Spec_Expression, for example within a pre/postcondition,
-- provide enough information for use of the subtype without
-- depending on full analysis and freezing, which will happen when
-- building the corresponding subprogram.
if In_Spec_Expression then
Analyze (Subtype_Mark (Obj_Def));
declare
Base_T : constant Entity_Id := Entity (Subtype_Mark (Obj_Def));
Decl : constant Node_Id :=
Make_Subtype_Declaration (Sloc (P),
Defining_Identifier => T,
Subtype_Indication => Relocate_Node (Obj_Def));
begin
Set_Etype (T, Base_T);
Mutate_Ekind (T, Subtype_Kind (Ekind (Base_T)));
Set_Parent (T, Obj_Def);
if Ekind (T) = E_Array_Subtype then
Set_First_Index (T, First_Index (Base_T));
Set_Is_Constrained (T);
elsif Ekind (T) = E_Record_Subtype then
Set_First_Entity (T, First_Entity (Base_T));
Set_Has_Discriminants (T, Has_Discriminants (Base_T));
Set_Is_Constrained (T);
end if;
Insert_Before (Related_Nod, Decl);
end;
return T;
end if;
-- When generating code, insert subtype declaration ahead of
-- declaration that generated it.
Insert_Action (Obj_Def,
Make_Subtype_Declaration (Sloc (P),
Defining_Identifier => T,
Subtype_Indication => Relocate_Node (Obj_Def)));
-- This subtype may need freezing, and this will not be done
-- automatically if the object declaration is not in declarative
-- part. Since this is an object declaration, the type cannot always
-- be frozen here. Deferred constants do not freeze their type
-- (which often enough will be private).
if Nkind (P) = N_Object_Declaration
and then Constant_Present (P)
and then No (Expression (P))
then
null;
-- Here we freeze the base type of object type to catch premature use
-- of discriminated private type without a full view.
else
Insert_Actions (Obj_Def, Freeze_Entity (Base_Type (T), P));
end if;
-- Ada 2005 AI-406: the object definition in an object declaration
-- can be an access definition.
elsif Def_Kind = N_Access_Definition then
T := Access_Definition (Related_Nod, Obj_Def);
Set_Is_Local_Anonymous_Access
(T, Ada_Version < Ada_2012
or else Nkind (P) /= N_Object_Declaration
or else Is_Library_Level_Entity (Defining_Identifier (P)));
-- Otherwise, the object definition is just a subtype_mark
else
T := Process_Subtype (Obj_Def, Related_Nod);
end if;
return T;
end Find_Type_Of_Object;
--------------------------------
-- Find_Type_Of_Subtype_Indic --
--------------------------------
function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
Typ : Entity_Id;
begin
-- Case of subtype mark with a constraint
if Nkind (S) = N_Subtype_Indication then
Find_Type (Subtype_Mark (S));
Typ := Entity (Subtype_Mark (S));
if not
Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
then
Error_Msg_N
("incorrect constraint for this kind of type", Constraint (S));
Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
end if;
-- Otherwise we have a subtype mark without a constraint
elsif Error_Posted (S) then
Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
return Any_Type;
else
Find_Type (S);
Typ := Entity (S);
end if;
return Typ;
end Find_Type_Of_Subtype_Indic;
-------------------------------------
-- Floating_Point_Type_Declaration --
-------------------------------------
procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Digs : constant Node_Id := Digits_Expression (Def);
Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
Digs_Val : Uint;
Base_Typ : Entity_Id;
Implicit_Base : Entity_Id;
function Can_Derive_From (E : Entity_Id) return Boolean;
-- Find if given digits value, and possibly a specified range, allows
-- derivation from specified type
procedure Convert_Bound (B : Node_Id);
-- If specified, the bounds must be static but may be of different
-- types. They must be converted into machine numbers of the base type,
-- in accordance with RM 4.9(38).
function Find_Base_Type return Entity_Id;
-- Find a predefined base type that Def can derive from, or generate
-- an error and substitute Long_Long_Float if none exists.
---------------------
-- Can_Derive_From --
---------------------
function Can_Derive_From (E : Entity_Id) return Boolean is
Spec : constant Entity_Id := Real_Range_Specification (Def);
begin
-- Check specified "digits" constraint
if Digs_Val > Digits_Value (E) then
return False;
end if;
-- Check for matching range, if specified
if Present (Spec) then
if Expr_Value_R (Type_Low_Bound (E)) >
Expr_Value_R (Low_Bound (Spec))
then
return False;
end if;
if Expr_Value_R (Type_High_Bound (E)) <
Expr_Value_R (High_Bound (Spec))
then
return False;
end if;
end if;
return True;
end Can_Derive_From;
-------------------
-- Convert_Bound --
--------------------
procedure Convert_Bound (B : Node_Id) is
begin
-- If the bound is not a literal it can only be static if it is
-- a static constant, possibly of a specified type.
if Is_Entity_Name (B)
and then Ekind (Entity (B)) = E_Constant
then
Rewrite (B, Constant_Value (Entity (B)));
end if;
if Nkind (B) = N_Real_Literal then
Set_Realval (B, Machine (Base_Typ, Realval (B), Round, B));
Set_Is_Machine_Number (B);
Set_Etype (B, Base_Typ);
end if;
end Convert_Bound;
--------------------
-- Find_Base_Type --
--------------------
function Find_Base_Type return Entity_Id is
Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
begin
-- Iterate over the predefined types in order, returning the first
-- one that Def can derive from.
while Present (Choice) loop
if Can_Derive_From (Node (Choice)) then
return Node (Choice);
end if;
Next_Elmt (Choice);
end loop;
-- If we can't derive from any existing type, use Long_Long_Float
-- and give appropriate message explaining the problem.
if Digs_Val > Max_Digs_Val then
-- It might be the case that there is a type with the requested
-- range, just not the combination of digits and range.
Error_Msg_N
("no predefined type has requested range and precision",
Real_Range_Specification (Def));
else
Error_Msg_N
("range too large for any predefined type",
Real_Range_Specification (Def));
end if;
return Standard_Long_Long_Float;
end Find_Base_Type;
-- Start of processing for Floating_Point_Type_Declaration
begin
Check_Restriction (No_Floating_Point, Def);
-- Create an implicit base type
Implicit_Base :=
Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
-- Analyze and verify digits value
Analyze_And_Resolve (Digs, Any_Integer);
Check_Digits_Expression (Digs);
Digs_Val := Expr_Value (Digs);
-- Process possible range spec and find correct type to derive from
Process_Real_Range_Specification (Def);
-- Check that requested number of digits is not too high.
if Digs_Val > Max_Digs_Val then
-- The check for Max_Base_Digits may be somewhat expensive, as it
-- requires reading System, so only do it when necessary.
declare
Max_Base_Digits : constant Uint :=
Expr_Value
(Expression
(Parent (RTE (RE_Max_Base_Digits))));
begin
if Digs_Val > Max_Base_Digits then
Error_Msg_Uint_1 := Max_Base_Digits;
Error_Msg_N ("digits value out of range, maximum is ^", Digs);
elsif No (Real_Range_Specification (Def)) then
Error_Msg_Uint_1 := Max_Digs_Val;
Error_Msg_N ("types with more than ^ digits need range spec "
& "(RM 3.5.7(6))", Digs);
end if;
end;
end if;
-- Find a suitable type to derive from or complain and use a substitute
Base_Typ := Find_Base_Type;
-- If there are bounds given in the declaration use them as the bounds
-- of the type, otherwise use the bounds of the predefined base type
-- that was chosen based on the Digits value.
if Present (Real_Range_Specification (Def)) then
Set_Scalar_Range (T, Real_Range_Specification (Def));
Set_Is_Constrained (T);
Convert_Bound (Type_Low_Bound (T));
Convert_Bound (Type_High_Bound (T));
else
Set_Scalar_Range (T, Scalar_Range (Base_Typ));
end if;
-- Complete definition of implicit base and declared first subtype. The
-- inheritance of the rep item chain ensures that SPARK-related pragmas
-- are not clobbered when the floating point type acts as a full view of
-- a private type.
Set_Etype (Implicit_Base, Base_Typ);
Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
Set_Size_Info (Implicit_Base, Base_Typ);
Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ));
Mutate_Ekind (T, E_Floating_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, Implicit_Base);
Set_RM_Size (T, RM_Size (Implicit_Base));
Inherit_Rep_Item_Chain (T, Implicit_Base);
if Digs_Val >= Uint_1 then
Set_Digits_Value (T, Digs_Val);
else
pragma Assert (Serious_Errors_Detected > 0); null;
end if;
end Floating_Point_Type_Declaration;
----------------------------
-- Get_Discriminant_Value --
----------------------------
-- This is the situation:
-- There is a non-derived type
-- type T0 (Dx, Dy, Dz...)
-- There are zero or more levels of derivation, with each derivation
-- either purely inheriting the discriminants, or defining its own.
-- type Ti is new Ti-1
-- or
-- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
-- or
-- subtype Ti is ...
-- The subtype issue is avoided by the use of Original_Record_Component,
-- and the fact that derived subtypes also derive the constraints.
-- This chain leads back from
-- Typ_For_Constraint
-- Typ_For_Constraint has discriminants, and the value for each
-- discriminant is given by its corresponding Elmt of Constraints.
-- Discriminant is some discriminant in this hierarchy
-- We need to return its value
-- We do this by recursively searching each level, and looking for
-- Discriminant. Once we get to the bottom, we start backing up
-- returning the value for it which may in turn be a discriminant
-- further up, so on the backup we continue the substitution.
function Get_Discriminant_Value
(Discriminant : Entity_Id;
Typ_For_Constraint : Entity_Id;
Constraint : Elist_Id) return Node_Id
is
function Root_Corresponding_Discriminant
(Discr : Entity_Id) return Entity_Id;
-- Given a discriminant, traverse the chain of inherited discriminants
-- and return the topmost discriminant.
function Search_Derivation_Levels
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
-- This is the routine that performs the recursive search of levels
-- as described above.
-------------------------------------
-- Root_Corresponding_Discriminant --
-------------------------------------
function Root_Corresponding_Discriminant
(Discr : Entity_Id) return Entity_Id
is
D : Entity_Id;
begin
D := Discr;
while Present (Corresponding_Discriminant (D)) loop
D := Corresponding_Discriminant (D);
end loop;
return D;
end Root_Corresponding_Discriminant;
------------------------------
-- Search_Derivation_Levels --
------------------------------
function Search_Derivation_Levels
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
is
Assoc : Elmt_Id;
Disc : Entity_Id;
Result : Node_Or_Entity_Id;
Result_Entity : Node_Id;
begin
-- If inappropriate type, return Error, this happens only in
-- cascaded error situations, and we want to avoid a blow up.
if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
return Error;
end if;
-- Look deeper if possible. Use Stored_Constraints only for
-- untagged types. For tagged types use the given constraint.
-- This asymmetry needs explanation???
if not Stored_Discrim_Values
and then Present (Stored_Constraint (Ti))
and then not Is_Tagged_Type (Ti)
then
Result :=
Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
else
declare
Td : Entity_Id := Etype (Ti);
begin
-- If the parent type is private, the full view may include
-- renamed discriminants, and it is those stored values that
-- may be needed (the partial view never has more information
-- than the full view).
if Is_Private_Type (Td) and then Present (Full_View (Td)) then
Td := Full_View (Td);
end if;
if Td = Ti then
Result := Discriminant;
else
if Present (Stored_Constraint (Ti)) then
Result :=
Search_Derivation_Levels
(Td, Stored_Constraint (Ti), True);
else
Result :=
Search_Derivation_Levels
(Td, Discrim_Values, Stored_Discrim_Values);
end if;
end if;
end;
end if;
-- Extra underlying places to search, if not found above. For
-- concurrent types, the relevant discriminant appears in the
-- corresponding record. For a type derived from a private type
-- without discriminant, the full view inherits the discriminants
-- of the full view of the parent.
if Result = Discriminant then
if Is_Concurrent_Type (Ti)
and then Present (Corresponding_Record_Type (Ti))
then
Result :=
Search_Derivation_Levels (
Corresponding_Record_Type (Ti),
Discrim_Values,
Stored_Discrim_Values);
elsif Is_Private_Type (Ti)
and then not Has_Discriminants (Ti)
and then Present (Full_View (Ti))
and then Etype (Full_View (Ti)) /= Ti
then
Result :=
Search_Derivation_Levels (
Full_View (Ti),
Discrim_Values,
Stored_Discrim_Values);
end if;
end if;
-- If Result is not a (reference to a) discriminant, return it,
-- otherwise set Result_Entity to the discriminant.
if Nkind (Result) = N_Defining_Identifier then
pragma Assert (Result = Discriminant);
Result_Entity := Result;
else
if not Denotes_Discriminant (Result) then
return Result;
end if;
Result_Entity := Entity (Result);
end if;
-- See if this level of derivation actually has discriminants because
-- tagged derivations can add them, hence the lower levels need not
-- have any.
if not Has_Discriminants (Ti) then
return Result;
end if;
-- Scan Ti's discriminants for Result_Entity, and return its
-- corresponding value, if any.
Result_Entity := Original_Record_Component (Result_Entity);
Assoc := First_Elmt (Discrim_Values);
if Stored_Discrim_Values then
Disc := First_Stored_Discriminant (Ti);
else
Disc := First_Discriminant (Ti);
end if;
while Present (Disc) loop
-- If no further associations return the discriminant, value will
-- be found on the second pass.
if No (Assoc) then
return Result;
end if;
if Original_Record_Component (Disc) = Result_Entity then
return Node (Assoc);
end if;
Next_Elmt (Assoc);
if Stored_Discrim_Values then
Next_Stored_Discriminant (Disc);
else
Next_Discriminant (Disc);
end if;
end loop;
-- Could not find it
return Result;
end Search_Derivation_Levels;
-- Local Variables
Result : Node_Or_Entity_Id;
-- Start of processing for Get_Discriminant_Value
begin
-- ??? This routine is a gigantic mess and will be deleted. For the
-- time being just test for the trivial case before calling recurse.
-- We are now celebrating the 20th anniversary of this comment!
if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
declare
D : Entity_Id;
E : Elmt_Id;
begin
D := First_Discriminant (Typ_For_Constraint);
E := First_Elmt (Constraint);
while Present (D) loop
if Chars (D) = Chars (Discriminant) then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
Result := Search_Derivation_Levels
(Typ_For_Constraint, Constraint, False);
-- ??? hack to disappear when this routine is gone
if Nkind (Result) = N_Defining_Identifier then
declare
D : Entity_Id;
E : Elmt_Id;
begin
D := First_Discriminant (Typ_For_Constraint);
E := First_Elmt (Constraint);
while Present (D) loop
if Root_Corresponding_Discriminant (D) = Discriminant then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
pragma Assert (Nkind (Result) /= N_Defining_Identifier);
return Result;
end Get_Discriminant_Value;
--------------------------
-- Has_Range_Constraint --
--------------------------
function Has_Range_Constraint (N : Node_Id) return Boolean is
C : constant Node_Id := Constraint (N);
begin
if Nkind (C) = N_Range_Constraint then
return True;
elsif Nkind (C) = N_Digits_Constraint then
return
Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
or else Present (Range_Constraint (C));
elsif Nkind (C) = N_Delta_Constraint then
return Present (Range_Constraint (C));
else
return False;
end if;
end Has_Range_Constraint;
------------------------
-- Inherit_Components --
------------------------
function Inherit_Components
(N : Node_Id;
Parent_Base : Entity_Id;
Derived_Base : Entity_Id;
Is_Tagged : Boolean;
Inherit_Discr : Boolean;
Discs : Elist_Id) return Elist_Id
is
Assoc_List : constant Elist_Id := New_Elmt_List;
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Stored_Discrim : Boolean := False);
-- Inherits component Old_C from Parent_Base to the Derived_Base. If
-- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
-- True, Old_C is a stored discriminant. If they are both false then
-- Old_C is a regular component.
-----------------------
-- Inherit_Component --
-----------------------
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Stored_Discrim : Boolean := False)
is
procedure Set_Anonymous_Type (Id : Entity_Id);
-- Id denotes the entity of an access discriminant or anonymous
-- access component. Set the type of Id to either the same type of
-- Old_C or create a new one depending on whether the parent and
-- the child types are in the same scope.
------------------------
-- Set_Anonymous_Type --
------------------------
procedure Set_Anonymous_Type (Id : Entity_Id) is
Old_Typ : constant Entity_Id := Etype (Old_C);
begin
if Scope (Parent_Base) = Scope (Derived_Base) then
Set_Etype (Id, Old_Typ);
-- The parent and the derived type are in two different scopes.
-- Reuse the type of the original discriminant / component by
-- copying it in order to preserve all attributes.
else
declare
Typ : constant Entity_Id := New_Copy (Old_Typ);
begin
Set_Etype (Id, Typ);
-- Since we do not generate component declarations for
-- inherited components, associate the itype with the
-- derived type.
Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
Set_Scope (Typ, Derived_Base);
end;
end if;
end Set_Anonymous_Type;
-- Local variables and constants
New_C : constant Entity_Id := New_Copy (Old_C);
Corr_Discrim : Entity_Id;
Discrim : Entity_Id;
-- Start of processing for Inherit_Component
begin
pragma Assert (not Is_Tagged or not Stored_Discrim);
Set_Parent (New_C, Parent (Old_C));
-- Regular discriminants and components must be inserted in the scope
-- of the Derived_Base. Do it here.
if not Stored_Discrim then
Enter_Name (New_C);
end if;
-- For tagged types the Original_Record_Component must point to
-- whatever this field was pointing to in the parent type. This has
-- already been achieved by the call to New_Copy above.
if not Is_Tagged then
Set_Original_Record_Component (New_C, New_C);
Set_Corresponding_Record_Component (New_C, Old_C);
end if;
-- Set the proper type of an access discriminant
if Ekind (New_C) = E_Discriminant
and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
then
Set_Anonymous_Type (New_C);
end if;
-- If we have inherited a component then see if its Etype contains
-- references to Parent_Base discriminants. In this case, replace
-- these references with the constraints given in Discs. We do not
-- do this for the partial view of private types because this is
-- not needed (only the components of the full view will be used
-- for code generation) and cause problem. We also avoid this
-- transformation in some error situations.
if Ekind (New_C) = E_Component then
-- Set the proper type of an anonymous access component
if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
Set_Anonymous_Type (New_C);
elsif (Is_Private_Type (Derived_Base)
and then not Is_Generic_Type (Derived_Base))
or else (Is_Empty_Elmt_List (Discs)
and then not Expander_Active)
then
Set_Etype (New_C, Etype (Old_C));
else
-- The current component introduces a circularity of the
-- following kind:
-- limited with Pack_2;
-- package Pack_1 is
-- type T_1 is tagged record
-- Comp : access Pack_2.T_2;
-- ...
-- end record;
-- end Pack_1;
-- with Pack_1;
-- package Pack_2 is
-- type T_2 is new Pack_1.T_1 with ...;
-- end Pack_2;
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Derived_Base, N, Parent_Base, Discs));
end if;
end if;
-- In derived tagged types it is illegal to reference a non
-- discriminant component in the parent type. To catch this, mark
-- these components with an Ekind of E_Void. This will be reset in
-- Record_Type_Definition after processing the record extension of
-- the derived type.
-- If the declaration is a private extension, there is no further
-- record extension to process, and the components retain their
-- current kind, because they are visible at this point.
if Is_Tagged and then Ekind (New_C) = E_Component
and then Nkind (N) /= N_Private_Extension_Declaration
then
Mutate_Ekind (New_C, E_Void);
end if;
if Plain_Discrim then
Set_Corresponding_Discriminant (New_C, Old_C);
Build_Discriminal (New_C);
-- If we are explicitly inheriting a stored discriminant it will be
-- completely hidden.
elsif Stored_Discrim then
Set_Corresponding_Discriminant (New_C, Empty);
Set_Discriminal (New_C, Empty);
Set_Is_Completely_Hidden (New_C);
-- Set the Original_Record_Component of each discriminant in the
-- derived base to point to the corresponding stored that we just
-- created.
Discrim := First_Discriminant (Derived_Base);
while Present (Discrim) loop
Corr_Discrim := Corresponding_Discriminant (Discrim);
-- Corr_Discrim could be missing in an error situation
if Present (Corr_Discrim)
and then Original_Record_Component (Corr_Discrim) = Old_C
then
Set_Original_Record_Component (Discrim, New_C);
Set_Corresponding_Record_Component (Discrim, Empty);
end if;
Next_Discriminant (Discrim);
end loop;
Append_Entity (New_C, Derived_Base);
end if;
if not Is_Tagged then
Append_Elmt (Old_C, Assoc_List);
Append_Elmt (New_C, Assoc_List);
end if;
end Inherit_Component;
-- Variables local to Inherit_Component
Loc : constant Source_Ptr := Sloc (N);
Parent_Discrim : Entity_Id;
Stored_Discrim : Entity_Id;
D : Entity_Id;
Component : Entity_Id;
-- Start of processing for Inherit_Components
begin
if not Is_Tagged then
Append_Elmt (Parent_Base, Assoc_List);
Append_Elmt (Derived_Base, Assoc_List);
end if;
-- Inherit parent discriminants if needed
if Inherit_Discr then
Parent_Discrim := First_Discriminant (Parent_Base);
while Present (Parent_Discrim) loop
Inherit_Component (Parent_Discrim, Plain_Discrim => True);
Next_Discriminant (Parent_Discrim);
end loop;
end if;
-- Create explicit stored discrims for untagged types when necessary
if not Has_Unknown_Discriminants (Derived_Base)
and then Has_Discriminants (Parent_Base)
and then not Is_Tagged
and then
(not Inherit_Discr
or else First_Discriminant (Parent_Base) /=
First_Stored_Discriminant (Parent_Base))
then
Stored_Discrim := First_Stored_Discriminant (Parent_Base);
while Present (Stored_Discrim) loop
Inherit_Component (Stored_Discrim, Stored_Discrim => True);
Next_Stored_Discriminant (Stored_Discrim);
end loop;
end if;
-- See if we can apply the second transformation for derived types, as
-- explained in point 6. in the comments above Build_Derived_Record_Type
-- This is achieved by appending Derived_Base discriminants into Discs,
-- which has the side effect of returning a non empty Discs list to the
-- caller of Inherit_Components, which is what we want. This must be
-- done for private derived types if there are explicit stored
-- discriminants, to ensure that we can retrieve the values of the
-- constraints provided in the ancestors.
if Inherit_Discr
and then Is_Empty_Elmt_List (Discs)
and then Present (First_Discriminant (Derived_Base))
and then
(not Is_Private_Type (Derived_Base)
or else Is_Completely_Hidden
(First_Stored_Discriminant (Derived_Base))
or else Is_Generic_Type (Derived_Base))
then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Append_Elmt (New_Occurrence_Of (D, Loc), Discs);
Next_Discriminant (D);
end loop;
end if;
-- Finally, inherit non-discriminant components unless they are not
-- visible because defined or inherited from the full view of the
-- parent. Don't inherit the _parent field of the parent type.
Component := First_Entity (Parent_Base);
while Present (Component) loop
-- Ada 2005 (AI-251): Do not inherit components associated with
-- secondary tags of the parent.
if Ekind (Component) = E_Component
and then Present (Related_Type (Component))
then
null;
elsif Ekind (Component) /= E_Component
or else Chars (Component) = Name_uParent
then
null;
-- If the derived type is within the parent type's declarative
-- region, then the components can still be inherited even though
-- they aren't visible at this point. This can occur for cases
-- such as within public child units where the components must
-- become visible upon entering the child unit's private part.
elsif not Is_Visible_Component (Component)
and then not In_Open_Scopes (Scope (Parent_Base))
then
null;
elsif Ekind (Derived_Base) in E_Private_Type | E_Limited_Private_Type
then
null;
else
Inherit_Component (Component);
end if;
Next_Entity (Component);
end loop;
-- For tagged derived types, inherited discriminants cannot be used in
-- component declarations of the record extension part. To achieve this
-- we mark the inherited discriminants as not visible.
if Is_Tagged and then Inherit_Discr then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Set_Is_Immediately_Visible (D, False);
Next_Discriminant (D);
end loop;
end if;
return Assoc_List;
end Inherit_Components;
----------------------
-- Is_EVF_Procedure --
----------------------
function Is_EVF_Procedure (Subp : Entity_Id) return Boolean is
Formal : Entity_Id;
begin
-- Examine the formals of an Extensions_Visible False procedure looking
-- for a controlling OUT parameter.
if Ekind (Subp) = E_Procedure
and then Extensions_Visible_Status (Subp) = Extensions_Visible_False
then
Formal := First_Formal (Subp);
while Present (Formal) loop
if Ekind (Formal) = E_Out_Parameter
and then Is_Controlling_Formal (Formal)
then
return True;
end if;
Next_Formal (Formal);
end loop;
end if;
return False;
end Is_EVF_Procedure;
--------------------------
-- Is_Private_Primitive --
--------------------------
function Is_Private_Primitive (Prim : Entity_Id) return Boolean is
Prim_Scope : constant Entity_Id := Scope (Prim);
Priv_Entity : Entity_Id;
begin
if Is_Package_Or_Generic_Package (Prim_Scope) then
Priv_Entity := First_Private_Entity (Prim_Scope);
while Present (Priv_Entity) loop
if Priv_Entity = Prim then
return True;
end if;
Next_Entity (Priv_Entity);
end loop;
end if;
return False;
end Is_Private_Primitive;
------------------------------
-- Is_Valid_Constraint_Kind --
------------------------------
function Is_Valid_Constraint_Kind
(T_Kind : Type_Kind;
Constraint_Kind : Node_Kind) return Boolean
is
begin
case T_Kind is
when Enumeration_Kind
| Integer_Kind
=>
return Constraint_Kind = N_Range_Constraint;
when Decimal_Fixed_Point_Kind =>
return Constraint_Kind in N_Digits_Constraint | N_Range_Constraint;
when Ordinary_Fixed_Point_Kind =>
return Constraint_Kind in N_Delta_Constraint | N_Range_Constraint;
when Float_Kind =>
return Constraint_Kind in N_Digits_Constraint | N_Range_Constraint;
when Access_Kind
| Array_Kind
| Class_Wide_Kind
| Concurrent_Kind
| Private_Kind
| E_Incomplete_Type
| E_Record_Subtype
| E_Record_Type
=>
return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
when others =>
return True; -- Error will be detected later
end case;
end Is_Valid_Constraint_Kind;
--------------------------
-- Is_Visible_Component --
--------------------------
function Is_Visible_Component
(C : Entity_Id;
N : Node_Id := Empty) return Boolean
is
Original_Comp : Entity_Id := Empty;
Original_Type : Entity_Id;
Type_Scope : Entity_Id;
function Is_Local_Type (Typ : Entity_Id) return Boolean;
-- Check whether parent type of inherited component is declared locally,
-- possibly within a nested package or instance. The current scope is
-- the derived record itself.
-------------------
-- Is_Local_Type --
-------------------
function Is_Local_Type (Typ : Entity_Id) return Boolean is
begin
return Scope_Within (Inner => Typ, Outer => Scope (Current_Scope));
end Is_Local_Type;
-- Start of processing for Is_Visible_Component
begin
if Ekind (C) in E_Component | E_Discriminant then
Original_Comp := Original_Record_Component (C);
end if;
if No (Original_Comp) then
-- Premature usage, or previous error
return False;
else
Original_Type := Scope (Original_Comp);
Type_Scope := Scope (Base_Type (Scope (C)));
end if;
-- This test only concerns tagged types
if not Is_Tagged_Type (Original_Type) then
-- Check if this is a renamed discriminant (hidden either by the
-- derived type or by some ancestor), unless we are analyzing code
-- generated by the expander since it may reference such components
-- (for example see the expansion of Deep_Adjust).
if Ekind (C) = E_Discriminant and then Present (N) then
return
not Comes_From_Source (N)
or else not Is_Completely_Hidden (C);
else
return True;
end if;
-- If it is _Parent or _Tag, there is no visibility issue
elsif not Comes_From_Source (Original_Comp) then
return True;
-- Discriminants are visible unless the (private) type has unknown
-- discriminants. If the discriminant reference is inserted for a
-- discriminant check on a full view it is also visible.
elsif Ekind (Original_Comp) = E_Discriminant
and then
(not Has_Unknown_Discriminants (Original_Type)
or else (Present (N)
and then Nkind (N) = N_Selected_Component
and then Nkind (Prefix (N)) = N_Type_Conversion
and then not Comes_From_Source (Prefix (N))))
then
return True;
-- If the component has been declared in an ancestor which is currently
-- a private type, then it is not visible. The same applies if the
-- component's containing type is not in an open scope and the original
-- component's enclosing type is a visible full view of a private type
-- (which can occur in cases where an attempt is being made to reference
-- a component in a sibling package that is inherited from a visible
-- component of a type in an ancestor package; the component in the
-- sibling package should not be visible even though the component it
-- inherited from is visible), but instance bodies are not subject to
-- this second case since they have the Has_Private_View mechanism to
-- ensure proper visibility. This does not apply however in the case
-- where the scope of the type is a private child unit, or when the
-- parent comes from a local package in which the ancestor is currently
-- visible. The latter suppression of visibility is needed for cases
-- that are tested in B730006.
elsif Is_Private_Type (Original_Type)
or else
(not Is_Private_Descendant (Type_Scope)
and then not In_Open_Scopes (Type_Scope)
and then Has_Private_Declaration (Original_Type)
and then not In_Instance_Body)
then
-- If the type derives from an entity in a formal package, there
-- are no additional visible components.
if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
N_Formal_Package_Declaration
then
return False;
-- if we are not in the private part of the current package, there
-- are no additional visible components.
elsif Ekind (Scope (Current_Scope)) = E_Package
and then not In_Private_Part (Scope (Current_Scope))
then
return False;
else
return
Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
and then In_Open_Scopes (Scope (Original_Type))
and then Is_Local_Type (Type_Scope);
end if;
-- There is another weird way in which a component may be invisible when
-- the private and the full view are not derived from the same ancestor.
-- Here is an example :
-- type A1 is tagged record F1 : integer; end record;
-- type A2 is new A1 with record F2 : integer; end record;
-- type T is new A1 with private;
-- private
-- type T is new A2 with null record;
-- In this case, the full view of T inherits F1 and F2 but the private
-- view inherits only F1
else
declare
Ancestor : Entity_Id := Scope (C);
begin
loop
if Ancestor = Original_Type then
return True;
-- The ancestor may have a partial view of the original type,
-- but if the full view is in scope, as in a child body, the
-- component is visible.
elsif In_Private_Part (Scope (Original_Type))
and then Full_View (Ancestor) = Original_Type
then
return True;
elsif Ancestor = Etype (Ancestor) then
-- No further ancestors to examine
return False;
end if;
Ancestor := Etype (Ancestor);
end loop;
end;
end if;
end Is_Visible_Component;
--------------------------
-- Make_Class_Wide_Type --
--------------------------
procedure Make_Class_Wide_Type (T : Entity_Id) is
CW_Type : Entity_Id;
CW_Name : Name_Id;
Next_E : Entity_Id;
Prev_E : Entity_Id;
begin
if Present (Class_Wide_Type (T)) then
-- The class-wide type is a partially decorated entity created for a
-- unanalyzed tagged type referenced through a limited with clause.
-- When the tagged type is analyzed, its class-wide type needs to be
-- redecorated. Note that we reuse the entity created by Decorate_
-- Tagged_Type in order to preserve all links.
if Materialize_Entity (Class_Wide_Type (T)) then
CW_Type := Class_Wide_Type (T);
Set_Materialize_Entity (CW_Type, False);
-- The class wide type can have been defined by the partial view, in
-- which case everything is already done.
else
return;
end if;
-- Default case, we need to create a new class-wide type
else
CW_Type :=
New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
end if;
-- Inherit root type characteristics
CW_Name := Chars (CW_Type);
Next_E := Next_Entity (CW_Type);
Prev_E := Prev_Entity (CW_Type);
Copy_Node (T, CW_Type);
Set_Comes_From_Source (CW_Type, False);
Set_Chars (CW_Type, CW_Name);
Set_Parent (CW_Type, Parent (T));
Set_Prev_Entity (CW_Type, Prev_E);
Set_Next_Entity (CW_Type, Next_E);
-- Ensure we have a new freeze node for the class-wide type. The partial
-- view may have freeze action of its own, requiring a proper freeze
-- node, and the same freeze node cannot be shared between the two
-- types.
Set_Has_Delayed_Freeze (CW_Type);
Set_Freeze_Node (CW_Type, Empty);
-- Customize the class-wide type: It has no prim. op., it cannot be
-- abstract, its Etype points back to the specific root type, and it
-- cannot have any invariants.
if Ekind (CW_Type) in Incomplete_Or_Private_Kind then
Reinit_Field_To_Zero (CW_Type, F_Private_Dependents);
elsif Ekind (CW_Type) in Concurrent_Kind then
Reinit_Field_To_Zero (CW_Type, F_First_Private_Entity);
Reinit_Field_To_Zero (CW_Type, F_Scope_Depth_Value);
if Ekind (CW_Type) in Task_Kind then
Reinit_Field_To_Zero (CW_Type, F_Is_Elaboration_Checks_OK_Id);
Reinit_Field_To_Zero (CW_Type, F_Is_Elaboration_Warnings_OK_Id);
end if;
if Ekind (CW_Type) in E_Task_Type | E_Protected_Type then
Reinit_Field_To_Zero (CW_Type, F_SPARK_Aux_Pragma_Inherited);
end if;
end if;
Mutate_Ekind (CW_Type, E_Class_Wide_Type);
Set_Is_Tagged_Type (CW_Type, True);
Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
Set_Is_Abstract_Type (CW_Type, False);
Set_Is_Constrained (CW_Type, False);
Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
Set_Default_SSO (CW_Type);
Set_Has_Inheritable_Invariants (CW_Type, False);
Set_Has_Inherited_Invariants (CW_Type, False);
Set_Has_Own_Invariants (CW_Type, False);
if Ekind (T) = E_Class_Wide_Subtype then
Set_Etype (CW_Type, Etype (Base_Type (T)));
else
Set_Etype (CW_Type, T);
end if;
Set_No_Tagged_Streams_Pragma (CW_Type, No_Tagged_Streams);
-- If this is the class_wide type of a constrained subtype, it does
-- not have discriminants.
Set_Has_Discriminants (CW_Type,
Has_Discriminants (T) and then not Is_Constrained (T));
Set_Has_Unknown_Discriminants (CW_Type, True);
Set_Class_Wide_Type (T, CW_Type);
Set_Equivalent_Type (CW_Type, Empty);
-- The class-wide type of a class-wide type is itself (RM 3.9(14))
Set_Class_Wide_Type (CW_Type, CW_Type);
end Make_Class_Wide_Type;
----------------
-- Make_Index --
----------------
procedure Make_Index
(N : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix_Index : Pos := 1)
is
R : Node_Id;
T : Entity_Id;
Def_Id : Entity_Id := Empty;
Found : Boolean := False;
begin
-- For a discrete range used in a constrained array definition and
-- defined by a range, an implicit conversion to the predefined type
-- INTEGER is assumed if each bound is either a numeric literal, a named
-- number, or an attribute, and the type of both bounds (prior to the
-- implicit conversion) is the type universal_integer. Otherwise, both
-- bounds must be of the same discrete type, other than universal
-- integer; this type must be determinable independently of the
-- context, but using the fact that the type must be discrete and that
-- both bounds must have the same type.
-- Character literals also have a universal type in the absence of
-- of additional context, and are resolved to Standard_Character.
if Nkind (N) = N_Range then
-- The index is given by a range constraint. The bounds are known
-- to be of a consistent type.
if not Is_Overloaded (N) then
T := Etype (N);
-- For universal bounds, choose the specific predefined type
if T = Universal_Integer then
T := Standard_Integer;
elsif T = Any_Character then
Ambiguous_Character (Low_Bound (N));
T := Standard_Character;
end if;
-- The node may be overloaded because some user-defined operators
-- are available, but if a universal interpretation exists it is
-- also the selected one.
elsif Universal_Interpretation (N) = Universal_Integer then
T := Standard_Integer;
else
T := Any_Type;
declare
Ind : Interp_Index;
It : Interp;
begin
Get_First_Interp (N, Ind, It);
while Present (It.Typ) loop
if Is_Discrete_Type (It.Typ) then
if Found
and then not Covers (It.Typ, T)
and then not Covers (T, It.Typ)
then
Error_Msg_N ("ambiguous bounds in discrete range", N);
exit;
else
T := It.Typ;
Found := True;
end if;
end if;
Get_Next_Interp (Ind, It);
end loop;
if T = Any_Type then
Error_Msg_N ("discrete type required for range", N);
Set_Etype (N, Any_Type);
return;
elsif T = Universal_Integer then
T := Standard_Integer;
end if;
end;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", N);
Set_Etype (N, Any_Type);
return;
end if;
-- If the range bounds are "T'First .. T'Last" where T is a name of a
-- discrete type, then use T as the type of the index.
if Nkind (Low_Bound (N)) = N_Attribute_Reference
and then Attribute_Name (Low_Bound (N)) = Name_First
and then Is_Entity_Name (Prefix (Low_Bound (N)))
and then Is_Discrete_Type (Entity (Prefix (Low_Bound (N))))
and then Nkind (High_Bound (N)) = N_Attribute_Reference
and then Attribute_Name (High_Bound (N)) = Name_Last
and then Is_Entity_Name (Prefix (High_Bound (N)))
and then Entity (Prefix (High_Bound (N))) = Def_Id
then
Def_Id := Entity (Prefix (Low_Bound (N)));
end if;
R := N;
Process_Range_Expr_In_Decl (R, T);
elsif Nkind (N) = N_Subtype_Indication then
-- The index is given by a subtype with a range constraint
T := Base_Type (Entity (Subtype_Mark (N)));
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", N);
Set_Etype (N, Any_Type);
return;
end if;
R := Range_Expression (Constraint (N));
Resolve (R, T);
Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (N)));
elsif Nkind (N) = N_Attribute_Reference then
-- Catch beginner's error (use of attribute other than 'Range)
if Attribute_Name (N) /= Name_Range then
Error_Msg_N ("expect attribute ''Range", N);
Set_Etype (N, Any_Type);
return;
end if;
-- If the node denotes the range of a type mark, that is also the
-- resulting type, and we do not need to create an Itype for it.
if Is_Entity_Name (Prefix (N))
and then Comes_From_Source (N)
and then Is_Discrete_Type (Entity (Prefix (N)))
then
Def_Id := Entity (Prefix (N));
end if;
Analyze_And_Resolve (N);
T := Etype (N);
R := N;
-- If none of the above, must be a subtype. We convert this to a
-- range attribute reference because in the case of declared first
-- named subtypes, the types in the range reference can be different
-- from the type of the entity. A range attribute normalizes the
-- reference and obtains the correct types for the bounds.
-- This transformation is in the nature of an expansion, is only
-- done if expansion is active. In particular, it is not done on
-- formal generic types, because we need to retain the name of the
-- original index for instantiation purposes.
else
if not Is_Entity_Name (N) or else not Is_Type (Entity (N)) then
Error_Msg_N ("invalid subtype mark in discrete range", N);
Set_Etype (N, Any_Integer);
return;
else
-- The type mark may be that of an incomplete type. It is only
-- now that we can get the full view, previous analysis does
-- not look specifically for a type mark.
Set_Entity (N, Get_Full_View (Entity (N)));
Set_Etype (N, Entity (N));
Def_Id := Entity (N);
if not Is_Discrete_Type (Def_Id) then
Error_Msg_N ("discrete type required for index", N);
Set_Etype (N, Any_Type);
return;
end if;
end if;
if Expander_Active then
Rewrite (N,
Make_Attribute_Reference (Sloc (N),
Attribute_Name => Name_Range,
Prefix => Relocate_Node (N)));
-- The original was a subtype mark that does not freeze. This
-- means that the rewritten version must not freeze either.
Set_Must_Not_Freeze (N);
Set_Must_Not_Freeze (Prefix (N));
Analyze_And_Resolve (N);
T := Etype (N);
R := N;
-- If expander is inactive, type is legal, nothing else to construct
else
return;
end if;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", N);
Set_Etype (N, Any_Type);
return;
elsif T = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- We will now create the appropriate Itype to describe the range, but
-- first a check. If we originally had a subtype, then we just label
-- the range with this subtype. Not only is there no need to construct
-- a new subtype, but it is wrong to do so for two reasons:
-- 1. A legality concern, if we have a subtype, it must not freeze,
-- and the Itype would cause freezing incorrectly
-- 2. An efficiency concern, if we created an Itype, it would not be
-- recognized as the same type for the purposes of eliminating
-- checks in some circumstances.
-- We signal this case by setting the subtype entity in Def_Id
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Is_Signed_Integer_Type (T) then
Mutate_Ekind (Def_Id, E_Signed_Integer_Subtype);
elsif Is_Modular_Integer_Type (T) then
Mutate_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Mutate_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_First_Literal (Def_Id, First_Literal (T));
end if;
Set_Size_Info (Def_Id, (T));
Set_RM_Size (Def_Id, RM_Size (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Scalar_Range (Def_Id, R);
Conditional_Delay (Def_Id, T);
-- In the subtype indication case inherit properties of the parent
if Nkind (N) = N_Subtype_Indication then
-- It is enough to inherit predicate flags and not the predicate
-- functions, because predicates on an index type are illegal
-- anyway and the flags are enough to detect them.
Inherit_Predicate_Flags (Def_Id, Entity (Subtype_Mark (N)));
-- If the immediate parent of the new subtype is nonstatic, then
-- the subtype we create is nonstatic as well, even if its bounds
-- are static.
if not Is_OK_Static_Subtype (Entity (Subtype_Mark (N))) then
Set_Is_Non_Static_Subtype (Def_Id);
end if;
end if;
Set_Parent (Def_Id, N);
end if;
-- Final step is to label the index with this constructed type
Set_Etype (N, Def_Id);
end Make_Index;
------------------------------
-- Modular_Type_Declaration --
------------------------------
procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Mod_Expr : constant Node_Id := Expression (Def);
M_Val : Uint;
procedure Set_Modular_Size (Bits : Int);
-- Sets RM_Size to Bits, and Esize to normal word size above this
----------------------
-- Set_Modular_Size --
----------------------
procedure Set_Modular_Size (Bits : Int) is
Siz : Int;
begin
Set_RM_Size (T, UI_From_Int (Bits));
if Bits < System_Max_Binary_Modulus_Power then
Siz := 8;
while Siz < 128 loop
exit when Bits <= Siz;
Siz := Siz * 2;
end loop;
Set_Esize (T, UI_From_Int (Siz));
else
Set_Esize (T, UI_From_Int (System_Max_Binary_Modulus_Power));
end if;
if not Non_Binary_Modulus (T) and then Esize (T) = RM_Size (T) then
Set_Is_Known_Valid (T);
end if;
end Set_Modular_Size;
-- Start of processing for Modular_Type_Declaration
begin
-- If the mod expression is (exactly) 2 * literal, where literal is
-- 128 or less, then almost certainly the * was meant to be **. Warn.
if Warn_On_Suspicious_Modulus_Value
and then Nkind (Mod_Expr) = N_Op_Multiply
and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
and then Intval (Right_Opnd (Mod_Expr)) <= Uint_128
then
Error_Msg_N
("suspicious MOD value, was '*'* intended'??.m?", Mod_Expr);
end if;
-- Proceed with analysis of mod expression
Analyze_And_Resolve (Mod_Expr, Any_Integer);
if Ekind (T) in Incomplete_Or_Private_Kind then
Reinit_Field_To_Zero (T, F_Stored_Constraint);
end if;
Set_Etype (T, T);
Mutate_Ekind (T, E_Modular_Integer_Type);
Reinit_Alignment (T);
Set_Is_Constrained (T);
if not Is_OK_Static_Expression (Mod_Expr) then
Flag_Non_Static_Expr
("non-static expression used for modular type bound!", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
else
M_Val := Expr_Value (Mod_Expr);
end if;
if M_Val < 1 then
Error_Msg_N ("modulus value must be positive", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
end if;
if M_Val > 2 ** Standard_Long_Integer_Size then
Check_Restriction (No_Long_Long_Integers, Mod_Expr);
end if;
Set_Modulus (T, M_Val);
-- Create bounds for the modular type based on the modulus given in
-- the type declaration and then analyze and resolve those bounds.
Set_Scalar_Range (T,
Make_Range (Sloc (Mod_Expr),
Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0),
High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
-- Properly analyze the literals for the range. We do this manually
-- because we can't go calling Resolve, since we are resolving these
-- bounds with the type, and this type is certainly not complete yet.
Set_Etype (Low_Bound (Scalar_Range (T)), T);
Set_Etype (High_Bound (Scalar_Range (T)), T);
Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
-- Loop through powers of two to find number of bits required
for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
-- Binary case
if M_Val = 2 ** Bits then
Set_Modular_Size (Bits);
return;
-- Nonbinary case
elsif M_Val < 2 ** Bits then
Set_Non_Binary_Modulus (T);
if Bits > System_Max_Nonbinary_Modulus_Power then
Error_Msg_Uint_1 :=
UI_From_Int (System_Max_Nonbinary_Modulus_Power);
Error_Msg_F
("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
return;
else
-- In the nonbinary case, set size as per RM 13.3(55)
Set_Modular_Size (Bits);
return;
end if;
end if;
end loop;
-- If we fall through, then the size exceed System.Max_Binary_Modulus
-- so we just signal an error and set the maximum size.
Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
Reinit_Alignment (T);
end Modular_Type_Declaration;
--------------------------
-- New_Concatenation_Op --
--------------------------
procedure New_Concatenation_Op (Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Typ);
Op : Entity_Id;
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
-- Create abbreviated declaration for the formal of a predefined
-- Operator 'Op' of type 'Typ'
--------------------
-- Make_Op_Formal --
--------------------
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
Formal : Entity_Id;
begin
Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
Set_Etype (Formal, Typ);
Set_Mechanism (Formal, Default_Mechanism);
return Formal;
end Make_Op_Formal;
-- Start of processing for New_Concatenation_Op
begin
Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
Mutate_Ekind (Op, E_Operator);
Set_Scope (Op, Current_Scope);
Set_Etype (Op, Typ);
Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
Set_Is_Immediately_Visible (Op);
Set_Is_Intrinsic_Subprogram (Op);
Set_Has_Completion (Op);
Append_Entity (Op, Current_Scope);
Set_Name_Entity_Id (Name_Op_Concat, Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
end New_Concatenation_Op;
-------------------------
-- OK_For_Limited_Init --
-------------------------
-- ???Check all calls of this, and compare the conditions under which it's
-- called.
function OK_For_Limited_Init
(Typ : Entity_Id;
Exp : Node_Id) return Boolean
is
begin
return Is_CPP_Constructor_Call (Exp)
or else (Ada_Version >= Ada_2005
and then not Debug_Flag_Dot_L
and then OK_For_Limited_Init_In_05 (Typ, Exp));
end OK_For_Limited_Init;
-------------------------------
-- OK_For_Limited_Init_In_05 --
-------------------------------
function OK_For_Limited_Init_In_05
(Typ : Entity_Id;
Exp : Node_Id) return Boolean
is
begin
-- An object of a limited interface type can be initialized with any
-- expression of a nonlimited descendant type. However this does not
-- apply if this is a view conversion of some other expression. This
-- is checked below.
if Is_Class_Wide_Type (Typ)
and then Is_Limited_Interface (Typ)
and then not Is_Limited_Type (Etype (Exp))
and then Nkind (Exp) /= N_Type_Conversion
then
return True;
end if;
-- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
-- case of limited aggregates (including extension aggregates), and
-- function calls. The function call may have been given in prefixed
-- notation, in which case the original node is an indexed component.
-- If the function is parameterless, the original node was an explicit
-- dereference. The function may also be parameterless, in which case
-- the source node is just an identifier.
-- A branch of a conditional expression may have been removed if the
-- condition is statically known. This happens during expansion, and
-- thus will not happen if previous errors were encountered. The check
-- will have been performed on the chosen branch, which replaces the
-- original conditional expression.
if No (Exp) then
return True;
end if;
case Nkind (Original_Node (Exp)) is
when N_Aggregate
| N_Delta_Aggregate
| N_Extension_Aggregate
| N_Function_Call
| N_Op
=>
return True;
when N_Identifier =>
return Present (Entity (Original_Node (Exp)))
and then Ekind (Entity (Original_Node (Exp))) = E_Function;
when N_Qualified_Expression =>
return
OK_For_Limited_Init_In_05
(Typ, Expression (Original_Node (Exp)));
-- Ada 2005 (AI-251): If a class-wide interface object is initialized
-- with a function call, the expander has rewritten the call into an
-- N_Type_Conversion node to force displacement of the pointer to
-- reference the component containing the secondary dispatch table.
-- Otherwise a type conversion is not a legal context.
-- A return statement for a build-in-place function returning a
-- synchronized type also introduces an unchecked conversion.
when N_Type_Conversion
| N_Unchecked_Type_Conversion
=>
return not Comes_From_Source (Exp)
and then
-- If the conversion has been rewritten, check Original_Node;
-- otherwise, check the expression of the compiler-generated
-- conversion (which is a conversion that we want to ignore
-- for purposes of the limited-initialization restrictions).
(if Is_Rewrite_Substitution (Exp)
then OK_For_Limited_Init_In_05 (Typ, Original_Node (Exp))
else OK_For_Limited_Init_In_05 (Typ, Expression (Exp)));
when N_Explicit_Dereference
| N_Indexed_Component
| N_Selected_Component
=>
return Nkind (Exp) = N_Function_Call;
-- A use of 'Input is a function call, hence allowed. Normally the
-- attribute will be changed to a call, but the attribute by itself
-- can occur with -gnatc.
when N_Attribute_Reference =>
return Attribute_Name (Original_Node (Exp)) = Name_Input;
-- "return raise ..." is OK
when N_Raise_Expression =>
return True;
-- For a case expression, all dependent expressions must be legal
when N_Case_Expression =>
declare
Alt : Node_Id;
begin
Alt := First (Alternatives (Original_Node (Exp)));
while Present (Alt) loop
if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
return False;
end if;
Next (Alt);
end loop;
return True;
end;
-- For an if expression, all dependent expressions must be legal
when N_If_Expression =>
declare
Then_Expr : constant Node_Id :=
Next (First (Expressions (Original_Node (Exp))));
Else_Expr : constant Node_Id := Next (Then_Expr);
begin
return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
and then
OK_For_Limited_Init_In_05 (Typ, Else_Expr);
end;
when others =>
return False;
end case;
end OK_For_Limited_Init_In_05;
-------------------------------------------
-- Ordinary_Fixed_Point_Type_Declaration --
-------------------------------------------
procedure Ordinary_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
RRS : constant Node_Id := Real_Range_Specification (Def);
Implicit_Base : Entity_Id;
Delta_Val : Ureal;
Small_Val : Ureal;
Low_Val : Ureal;
High_Val : Ureal;
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Any_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
Set_Delta_Value (Implicit_Base, Delta_Val);
-- Compute default small from given delta, which is the largest power
-- of two that does not exceed the given delta value.
declare
Tmp : Ureal;
Scale : Int;
begin
Tmp := Ureal_1;
Scale := 0;
if Delta_Val < Ureal_1 then
while Delta_Val < Tmp loop
Tmp := Tmp / Ureal_2;
Scale := Scale + 1;
end loop;
else
loop
Tmp := Tmp * Ureal_2;
exit when Tmp > Delta_Val;
Scale := Scale - 1;
end loop;
end if;
Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
end;
Set_Small_Value (Implicit_Base, Small_Val);
-- If no range was given, set a dummy range
if RRS <= Empty_Or_Error then
Low_Val := -Small_Val;
High_Val := Small_Val;
-- Otherwise analyze and process given range
else
declare
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
-- Obtain and set the range
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val > High_Val then
Error_Msg_NE ("??fixed point type& has null range", Def, T);
end if;
end;
end if;
-- The range for both the implicit base and the declared first subtype
-- cannot be set yet, so we use the special routine Set_Fixed_Range to
-- set a temporary range in place. Note that the bounds of the base
-- type will be widened to be symmetrical and to fill the available
-- bits when the type is frozen.
-- We could do this with all discrete types, and probably should, but
-- we absolutely have to do it for fixed-point, since the end-points
-- of the range and the size are determined by the small value, which
-- could be reset before the freeze point.
Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
-- Complete definition of first subtype. The inheritance of the rep item
-- chain ensures that SPARK-related pragmas are not clobbered when the
-- ordinary fixed point type acts as a full view of a private type.
Mutate_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Reinit_Size_Align (T);
Inherit_Rep_Item_Chain (T, Implicit_Base);
Set_Small_Value (T, Small_Val);
Set_Delta_Value (T, Delta_Val);
Set_Is_Constrained (T);
end Ordinary_Fixed_Point_Type_Declaration;
----------------------------------
-- Preanalyze_Assert_Expression --
----------------------------------
procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is
begin
In_Assertion_Expr := In_Assertion_Expr + 1;
Preanalyze_Spec_Expression (N, T);
In_Assertion_Expr := In_Assertion_Expr - 1;
end Preanalyze_Assert_Expression;
-- ??? The variant below explicitly saves and restores all the flags,
-- because it is impossible to compose the existing variety of
-- Analyze/Resolve (and their wrappers, e.g. Preanalyze_Spec_Expression)
-- to achieve the desired semantics.
procedure Preanalyze_Assert_Expression (N : Node_Id) is
Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
Save_Must_Not_Freeze : constant Boolean := Must_Not_Freeze (N);
Save_Full_Analysis : constant Boolean := Full_Analysis;
begin
In_Assertion_Expr := In_Assertion_Expr + 1;
In_Spec_Expression := True;
Set_Must_Not_Freeze (N);
Inside_Preanalysis_Without_Freezing :=
Inside_Preanalysis_Without_Freezing + 1;
Full_Analysis := False;
Expander_Mode_Save_And_Set (False);
if GNATprove_Mode then
Analyze_And_Resolve (N);
else
Analyze_And_Resolve (N, Suppress => All_Checks);
end if;
Expander_Mode_Restore;
Full_Analysis := Save_Full_Analysis;
Inside_Preanalysis_Without_Freezing :=
Inside_Preanalysis_Without_Freezing - 1;
Set_Must_Not_Freeze (N, Save_Must_Not_Freeze);
In_Spec_Expression := Save_In_Spec_Expression;
In_Assertion_Expr := In_Assertion_Expr - 1;
end Preanalyze_Assert_Expression;
-----------------------------------
-- Preanalyze_Default_Expression --
-----------------------------------
procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id) is
Save_In_Default_Expr : constant Boolean := In_Default_Expr;
Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
begin
In_Default_Expr := True;
In_Spec_Expression := True;
Preanalyze_With_Freezing_And_Resolve (N, T);
In_Default_Expr := Save_In_Default_Expr;
In_Spec_Expression := Save_In_Spec_Expression;
end Preanalyze_Default_Expression;
--------------------------------
-- Preanalyze_Spec_Expression --
--------------------------------
procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
begin
In_Spec_Expression := True;
Preanalyze_And_Resolve (N, T);
In_Spec_Expression := Save_In_Spec_Expression;
end Preanalyze_Spec_Expression;
----------------------------------------
-- Prepare_Private_Subtype_Completion --
----------------------------------------
procedure Prepare_Private_Subtype_Completion
(Id : Entity_Id;
Related_Nod : Node_Id)
is
Id_B : constant Entity_Id := Base_Type (Id);
Full_B : constant Entity_Id := Full_View (Id_B);
Full : Entity_Id;
begin
if Present (Full_B) then
-- The Base_Type is already completed, we can complete the subtype
-- now. We have to create a new entity with the same name, Thus we
-- can't use Create_Itype.
Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
Set_Is_Itype (Full);
Set_Associated_Node_For_Itype (Full, Related_Nod);
Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
Set_Full_View (Id, Full);
end if;
-- The parent subtype may be private, but the base might not, in some
-- nested instances. In that case, the subtype does not need to be
-- exchanged. It would still be nice to make private subtypes and their
-- bases consistent at all times ???
if Is_Private_Type (Id_B) then
Append_Elmt (Id, Private_Dependents (Id_B));
end if;
end Prepare_Private_Subtype_Completion;
---------------------------
-- Process_Discriminants --
---------------------------
procedure Process_Discriminants
(N : Node_Id;
Prev : Entity_Id := Empty)
is
Elist : constant Elist_Id := New_Elmt_List;
Id : Node_Id;
Discr : Node_Id;
Discr_Number : Uint;
Discr_Type : Entity_Id;
Default_Present : Boolean := False;
Default_Not_Present : Boolean := False;
begin
-- A composite type other than an array type can have discriminants.
-- On entry, the current scope is the composite type.
-- The discriminants are initially entered into the scope of the type
-- via Enter_Name with the default Ekind of E_Void to prevent premature
-- use, as explained at the end of this procedure.
Discr := First (Discriminant_Specifications (N));
while Present (Discr) loop
Enter_Name (Defining_Identifier (Discr));
-- For navigation purposes we add a reference to the discriminant
-- in the entity for the type. If the current declaration is a
-- completion, place references on the partial view. Otherwise the
-- type is the current scope.
if Present (Prev) then
-- The references go on the partial view, if present. If the
-- partial view has discriminants, the references have been
-- generated already.
if not Has_Discriminants (Prev) then
Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
end if;
else
Generate_Reference
(Current_Scope, Defining_Identifier (Discr), 'd');
end if;
if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
Check_Anonymous_Access_Component
(Typ_Decl => N,
Typ => Defining_Identifier (N),
Prev => Prev,
Comp_Def => Discr,
Access_Def => Discriminant_Type (Discr));
-- if Check_Anonymous_Access_Component replaced Discr then
-- its Original_Node points to the old Discr and the access type
-- for Discr_Type has already been created.
if Is_Rewrite_Substitution (Discr) then
Discr_Type := Etype (Discriminant_Type (Discr));
else
Discr_Type :=
Access_Definition (Discr, Discriminant_Type (Discr));
-- Ada 2005 (AI-254)
if Present (Access_To_Subprogram_Definition
(Discriminant_Type (Discr)))
and then Protected_Present (Access_To_Subprogram_Definition
(Discriminant_Type (Discr)))
then
Discr_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram (Discr);
end if;
end if;
else
Find_Type (Discriminant_Type (Discr));
Discr_Type := Etype (Discriminant_Type (Discr));
if Error_Posted (Discriminant_Type (Discr)) then
Discr_Type := Any_Type;
end if;
end if;
-- Handling of discriminants that are access types
if Is_Access_Type (Discr_Type) then
-- Ada 2005 (AI-230): Access discriminant allowed in non-
-- limited record types
if Ada_Version < Ada_2005 then
Check_Access_Discriminant_Requires_Limited
(Discr, Discriminant_Type (Discr));
end if;
if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
Error_Msg_N
("(Ada 83) access discriminant not allowed", Discr);
end if;
-- If not access type, must be a discrete type
elsif not Is_Discrete_Type (Discr_Type) then
Error_Msg_N
("discriminants must have a discrete or access type",
Discriminant_Type (Discr));
end if;
Set_Etype (Defining_Identifier (Discr), Discr_Type);
-- If a discriminant specification includes the assignment compound
-- delimiter followed by an expression, the expression is the default
-- expression of the discriminant; the default expression must be of
-- the type of the discriminant. (RM 3.7.1) Since this expression is
-- a default expression, we do the special preanalysis, since this
-- expression does not freeze (see section "Handling of Default and
-- Per-Object Expressions" in spec of package Sem).
if Present (Expression (Discr)) then
Preanalyze_Default_Expression (Expression (Discr), Discr_Type);
-- Legaity checks
if Nkind (N) = N_Formal_Type_Declaration then
Error_Msg_N
("discriminant defaults not allowed for formal type",
Expression (Discr));
-- Flag an error for a tagged type with defaulted discriminants,
-- excluding limited tagged types when compiling for Ada 2012
-- (see AI05-0214).
elsif Is_Tagged_Type (Current_Scope)
and then (not Is_Limited_Type (Current_Scope)
or else Ada_Version < Ada_2012)
and then Comes_From_Source (N)
then
-- Note: see similar test in Check_Or_Process_Discriminants, to
-- handle the (illegal) case of the completion of an untagged
-- view with discriminants with defaults by a tagged full view.
-- We skip the check if Discr does not come from source, to
-- account for the case of an untagged derived type providing
-- defaults for a renamed discriminant from a private untagged
-- ancestor with a tagged full view (ACATS B460006).
if Ada_Version >= Ada_2012 then
Error_Msg_N
("discriminants of nonlimited tagged type cannot have"
& " defaults",
Expression (Discr));
else
Error_Msg_N
("discriminants of tagged type cannot have defaults",
Expression (Discr));
end if;
else
Default_Present := True;
Append_Elmt (Expression (Discr), Elist);
-- Tag the defining identifiers for the discriminants with
-- their corresponding default expressions from the tree.
Set_Discriminant_Default_Value
(Defining_Identifier (Discr), Expression (Discr));
end if;
-- In gnatc or GNATprove mode, make sure set Do_Range_Check flag
-- gets set unless we can be sure that no range check is required.
if not Expander_Active
and then not
Is_In_Range
(Expression (Discr), Discr_Type, Assume_Valid => True)
then
Set_Do_Range_Check (Expression (Discr));
end if;
-- No default discriminant value given
else
Default_Not_Present := True;
end if;
-- Ada 2005 (AI-231): Create an Itype that is a duplicate of
-- Discr_Type but with the null-exclusion attribute
if Ada_Version >= Ada_2005 then
-- Ada 2005 (AI-231): Static checks
if Can_Never_Be_Null (Discr_Type) then
Null_Exclusion_Static_Checks (Discr);
elsif Is_Access_Type (Discr_Type)
and then Null_Exclusion_Present (Discr)
-- No need to check itypes because in their case this check
-- was done at their point of creation
and then not Is_Itype (Discr_Type)
then
if Can_Never_Be_Null (Discr_Type) then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)",
Discr,
Discr_Type);
end if;
Set_Etype (Defining_Identifier (Discr),
Create_Null_Excluding_Itype
(T => Discr_Type,
Related_Nod => Discr));
-- Check for improper null exclusion if the type is otherwise
-- legal for a discriminant.
elsif Null_Exclusion_Present (Discr)
and then Is_Discrete_Type (Discr_Type)
then
Error_Msg_N
("null exclusion can only apply to an access type", Discr);
end if;
-- Ada 2005 (AI-402): access discriminants of nonlimited types
-- can't have defaults. Synchronized types, or types that are
-- explicitly limited are fine, but special tests apply to derived
-- types in generics: in a generic body we have to assume the
-- worst, and therefore defaults are not allowed if the parent is
-- a generic formal private type (see ACATS B370001).
if Is_Access_Type (Discr_Type) and then Default_Present then
if Ekind (Discr_Type) /= E_Anonymous_Access_Type
or else Is_Limited_Record (Current_Scope)
or else Is_Concurrent_Type (Current_Scope)
or else Is_Concurrent_Record_Type (Current_Scope)
or else Ekind (Current_Scope) = E_Limited_Private_Type
then
if not Is_Derived_Type (Current_Scope)
or else not Is_Generic_Type (Etype (Current_Scope))
or else not In_Package_Body (Scope (Etype (Current_Scope)))
or else Limited_Present
(Type_Definition (Parent (Current_Scope)))
then
null;
else
Error_Msg_N
("access discriminants of nonlimited types cannot "
& "have defaults", Expression (Discr));
end if;
elsif Present (Expression (Discr)) then
Error_Msg_N
("(Ada 2005) access discriminants of nonlimited types "
& "cannot have defaults", Expression (Discr));
end if;
end if;
end if;
-- A discriminant cannot be effectively volatile (SPARK RM 7.1.3(4)).
-- This check is relevant only when SPARK_Mode is on as it is not a
-- standard Ada legality rule. The only way for a discriminant to be
-- effectively volatile is to have an effectively volatile type, so
-- we check this directly, because the Ekind of Discr might not be
-- set yet (to help preventing cascaded errors on derived types).
if SPARK_Mode = On
and then Is_Effectively_Volatile (Discr_Type)
then
Error_Msg_N ("discriminant cannot be volatile", Discr);
end if;
Next (Discr);
end loop;
-- An element list consisting of the default expressions of the
-- discriminants is constructed in the above loop and used to set
-- the Discriminant_Constraint attribute for the type. If an object
-- is declared of this (record or task) type without any explicit
-- discriminant constraint given, this element list will form the
-- actual parameters for the corresponding initialization procedure
-- for the type.
Set_Discriminant_Constraint (Current_Scope, Elist);
Set_Stored_Constraint (Current_Scope, No_Elist);
-- Default expressions must be provided either for all or for none
-- of the discriminants of a discriminant part. (RM 3.7.1)
if Default_Present and then Default_Not_Present then
Error_Msg_N
("incomplete specification of defaults for discriminants", N);
end if;
-- The use of the name of a discriminant is not allowed in default
-- expressions of a discriminant part if the specification of the
-- discriminant is itself given in the discriminant part. (RM 3.7.1)
-- To detect this, the discriminant names are entered initially with an
-- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
-- attempt to use a void entity (for example in an expression that is
-- type-checked) produces the error message: premature usage. Now after
-- completing the semantic analysis of the discriminant part, we can set
-- the Ekind of all the discriminants appropriately.
Discr := First (Discriminant_Specifications (N));
Discr_Number := Uint_1;
while Present (Discr) loop
Id := Defining_Identifier (Discr);
if Ekind (Id) = E_In_Parameter then
Reinit_Field_To_Zero (Id, F_Discriminal_Link);
end if;
Mutate_Ekind (Id, E_Discriminant);
Reinit_Component_Location (Id);
Reinit_Esize (Id);
Set_Discriminant_Number (Id, Discr_Number);
-- Make sure this is always set, even in illegal programs
Set_Corresponding_Discriminant (Id, Empty);
-- Initialize the Original_Record_Component to the entity itself.
-- Inherit_Components will propagate the right value to
-- discriminants in derived record types.
Set_Original_Record_Component (Id, Id);
-- Create the discriminal for the discriminant
Build_Discriminal (Id);
Next (Discr);
Discr_Number := Discr_Number + 1;
end loop;
Set_Has_Discriminants (Current_Scope);
end Process_Discriminants;
-----------------------
-- Process_Full_View --
-----------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
procedure Collect_Implemented_Interfaces
(Typ : Entity_Id;
Ifaces : Elist_Id);
-- Ada 2005: Gather all the interfaces that Typ directly or
-- inherently implements. Duplicate entries are not added to
-- the list Ifaces.
------------------------------------
-- Collect_Implemented_Interfaces --
------------------------------------
procedure Collect_Implemented_Interfaces
(Typ : Entity_Id;
Ifaces : Elist_Id)
is
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
begin
-- Abstract interfaces are only associated with tagged record types
if not Is_Tagged_Type (Typ) or else not Is_Record_Type (Typ) then
return;
end if;
-- Recursively climb to the ancestors
if Etype (Typ) /= Typ
-- Protect the frontend against wrong cyclic declarations like:
-- type B is new A with private;
-- type C is new A with private;
-- private
-- type B is new C with null record;
-- type C is new B with null record;
and then Etype (Typ) /= Priv_T
and then Etype (Typ) /= Full_T
then
-- Keep separate the management of private type declarations
if Ekind (Typ) = E_Record_Type_With_Private then
-- Handle the following illegal usage:
-- type Private_Type is tagged private;
-- private
-- type Private_Type is new Type_Implementing_Iface;
if Present (Full_View (Typ))
and then Etype (Typ) /= Full_View (Typ)
then
if Is_Interface (Etype (Typ)) then
Append_Unique_Elmt (Etype (Typ), Ifaces);
end if;
Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
end if;
-- Non-private types
else
if Is_Interface (Etype (Typ)) then
Append_Unique_Elmt (Etype (Typ), Ifaces);
end if;
Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
end if;
end if;
-- Handle entities in the list of abstract interfaces
if Present (Interfaces (Typ)) then
Iface_Elmt := First_Elmt (Interfaces (Typ));
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
pragma Assert (Is_Interface (Iface));
if not Contain_Interface (Iface, Ifaces) then
Append_Elmt (Iface, Ifaces);
Collect_Implemented_Interfaces (Iface, Ifaces);
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
end Collect_Implemented_Interfaces;
-- Local variables
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Full_Indic : Node_Id;
Full_Parent : Entity_Id;
Priv_Parent : Entity_Id;
-- Start of processing for Process_Full_View
begin
Mark_And_Set_Ghost_Completion (N, Priv_T);
-- First some sanity checks that must be done after semantic
-- decoration of the full view and thus cannot be placed with other
-- similar checks in Find_Type_Name
if not Is_Limited_Type (Priv_T)
and then (Is_Limited_Type (Full_T)
or else Is_Limited_Composite (Full_T))
then
if In_Instance then
null;
else
Error_Msg_N
("completion of nonlimited type cannot be limited", Full_T);
Explain_Limited_Type (Full_T, Full_T);
end if;
elsif Is_Abstract_Type (Full_T)
and then not Is_Abstract_Type (Priv_T)
then
Error_Msg_N
("completion of nonabstract type cannot be abstract", Full_T);
elsif Is_Tagged_Type (Priv_T)
and then Is_Limited_Type (Priv_T)
and then not Is_Limited_Type (Full_T)
then
-- If pragma CPP_Class was applied to the private declaration
-- propagate the limitedness to the full-view
if Is_CPP_Class (Priv_T) then
Set_Is_Limited_Record (Full_T);
-- GNAT allow its own definition of Limited_Controlled to disobey
-- this rule in order in ease the implementation. This test is safe
-- because Root_Controlled is defined in a child of System that
-- normal programs are not supposed to use.
elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then
Set_Is_Limited_Composite (Full_T);
else
Error_Msg_N
("completion of limited tagged type must be limited", Full_T);
end if;
elsif Is_Generic_Type (Priv_T) then
Error_Msg_N ("generic type cannot have a completion", Full_T);
end if;
-- Check that ancestor interfaces of private and full views are
-- consistent. We omit this check for synchronized types because
-- they are performed on the corresponding record type when frozen.
if Ada_Version >= Ada_2005
and then Is_Tagged_Type (Priv_T)
and then Is_Tagged_Type (Full_T)
and then not Is_Concurrent_Type (Full_T)
then
declare
Iface : Entity_Id;
Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
begin
Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
-- Ada 2005 (AI-251): The partial view shall be a descendant of
-- an interface type if and only if the full type is descendant
-- of the interface type (AARM 7.3 (7.3/2)).
Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
if Present (Iface) then
Error_Msg_NE
("interface in partial view& not implemented by full type "
& "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
end if;
Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
if Present (Iface) then
Error_Msg_NE
("interface & not implemented by partial view "
& "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
end if;
end;
end if;
if Is_Tagged_Type (Priv_T)
and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
and then Is_Derived_Type (Full_T)
then
Priv_Parent := Etype (Priv_T);
-- The full view of a private extension may have been transformed
-- into an unconstrained derived type declaration and a subtype
-- declaration (see build_derived_record_type for details).
if Nkind (N) = N_Subtype_Declaration then
Full_Indic := Subtype_Indication (N);
Full_Parent := Etype (Base_Type (Full_T));
else
Full_Indic := Subtype_Indication (Type_Definition (N));
Full_Parent := Etype (Full_T);
end if;
-- Check that the parent type of the full type is a descendant of
-- the ancestor subtype given in the private extension. If either
-- entity has an Etype equal to Any_Type then we had some previous
-- error situation [7.3(8)].
if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
goto Leave;
-- Ada 2005 (AI-251): Interfaces in the full type can be given in
-- any order. Therefore we don't have to check that its parent must
-- be a descendant of the parent of the private type declaration.
elsif Is_Interface (Priv_Parent)
and then Is_Interface (Full_Parent)
then
null;
-- Ada 2005 (AI-251): If the parent of the private type declaration
-- is an interface there is no need to check that it is an ancestor
-- of the associated full type declaration. The required tests for
-- this case are performed by Build_Derived_Record_Type.
elsif not Is_Interface (Base_Type (Priv_Parent))
and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
then
Error_Msg_N
("parent of full type must descend from parent of private "
& "extension", Full_Indic);
-- First check a formal restriction, and then proceed with checking
-- Ada rules. Since the formal restriction is not a serious error, we
-- don't prevent further error detection for this check, hence the
-- ELSE.
else
-- Check the rules of 7.3(10): if the private extension inherits
-- known discriminants, then the full type must also inherit those
-- discriminants from the same (ancestor) type, and the parent
-- subtype of the full type must be constrained if and only if
-- the ancestor subtype of the private extension is constrained.
if No (Discriminant_Specifications (Parent (Priv_T)))
and then not Has_Unknown_Discriminants (Priv_T)
and then Has_Discriminants (Base_Type (Priv_Parent))
then
declare
Priv_Indic : constant Node_Id :=
Subtype_Indication (Parent (Priv_T));
Priv_Constr : constant Boolean :=
Is_Constrained (Priv_Parent)
or else
Nkind (Priv_Indic) = N_Subtype_Indication
or else
Is_Constrained (Entity (Priv_Indic));
Full_Constr : constant Boolean :=
Is_Constrained (Full_Parent)
or else
Nkind (Full_Indic) = N_Subtype_Indication
or else
Is_Constrained (Entity (Full_Indic));
Priv_Discr : Entity_Id;
Full_Discr : Entity_Id;
begin
Priv_Discr := First_Discriminant (Priv_Parent);
Full_Discr := First_Discriminant (Full_Parent);
while Present (Priv_Discr) and then Present (Full_Discr) loop
if Original_Record_Component (Priv_Discr) =
Original_Record_Component (Full_Discr)
or else
Corresponding_Discriminant (Priv_Discr) =
Corresponding_Discriminant (Full_Discr)
then
null;
else
exit;
end if;
Next_Discriminant (Priv_Discr);
Next_Discriminant (Full_Discr);
end loop;
if Present (Priv_Discr) or else Present (Full_Discr) then
Error_Msg_N
("full view must inherit discriminants of the parent "
& "type used in the private extension", Full_Indic);
elsif Priv_Constr and then not Full_Constr then
Error_Msg_N
("parent subtype of full type must be constrained",
Full_Indic);
elsif Full_Constr and then not Priv_Constr then
Error_Msg_N
("parent subtype of full type must be unconstrained",
Full_Indic);
end if;
end;
-- Check the rules of 7.3(12): if a partial view has neither
-- known or unknown discriminants, then the full type
-- declaration shall define a definite subtype.
elsif not Has_Unknown_Discriminants (Priv_T)
and then not Has_Discriminants (Priv_T)
and then not Is_Constrained (Full_T)
then
Error_Msg_N
("full view must define a constrained type if partial view "
& "has no discriminants", Full_T);
end if;
-- Do we implement the following properly???
-- If the ancestor subtype of a private extension has constrained
-- discriminants, then the parent subtype of the full view shall
-- impose a statically matching constraint on those discriminants
-- [7.3(13)].
end if;
else
-- For untagged types, verify that a type without discriminants is
-- not completed with an unconstrained type. A separate error message
-- is produced if the full type has defaulted discriminants.
if Is_Definite_Subtype (Priv_T)
and then not Is_Definite_Subtype (Full_T)
then
Error_Msg_Sloc := Sloc (Parent (Priv_T));
Error_Msg_NE
("full view of& not compatible with declaration#",
Full_T, Priv_T);
if not Is_Tagged_Type (Full_T) then
Error_Msg_N
("\one is constrained, the other unconstrained", Full_T);
end if;
end if;
end if;
-- AI-419: verify that the use of "limited" is consistent
declare
Orig_Decl : constant Node_Id := Original_Node (N);
begin
if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration