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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 3 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, 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 Debug; use Debug;
with Elists; use Elists;
with Einfo; use Einfo;
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 Fname; use Fname;
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 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_Elim; use Sem_Elim;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Prag; use Sem_Prag;
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 Sinput; use Sinput;
with Snames; use Snames;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
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 Analyze_Object_Contract (Obj_Id : Entity_Id);
-- Analyze all delayed pragmas chained on the contract of object Obj_Id as
-- if they appeared at the end of the declarative region. The pragmas to be
-- considered are:
-- Async_Readers
-- Async_Writers
-- Effective_Reads
-- Effective_Writes
-- Part_Of
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. That is its sole purpose is the designated type of an
-- access type -- in which case a Private_Subtype Is_For_Access_Subtype
-- is built to avoid freezing T when the access subtype is frozen.
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 Build_Underlying_Full_View
(N : Node_Id;
Typ : Entity_Id;
Par : Entity_Id);
-- If the completion of a private type is itself derived from a private
-- type, or if the full view of a private subtype is itself private, the
-- back-end has no way to compute the actual size of this type. We build
-- an internal subtype declaration of the proper parent type to convey
-- this information. This extra mechanism is needed because a full
-- view cannot itself have a full view (it would get clobbered during
-- view exchanges).
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_Components
(Typ_Decl : Node_Id;
Typ : Entity_Id;
Prev : Entity_Id;
Comp_List : 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_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 : Node_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 : Node_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 : Node_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 : Nat);
-- 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 : Node_Id; S : Node_Id);
-- Build subtype of a signed or modular integer type
procedure Constrain_Ordinary_Fixed (Def_Id : Node_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.
procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id);
-- Propagate static and dynamic predicate flags from a parent to the
-- subtype in a subtype declaration with and without constraints.
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_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 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 Propagate_Default_Init_Cond_Attributes
(From_Typ : Entity_Id;
To_Typ : Entity_Id;
Parent_To_Derivation : Boolean := False;
Private_To_Full_View : Boolean := False);
-- Subsidiary to routines Build_Derived_Type and Process_Full_View. Inherit
-- all attributes related to pragma Default_Initial_Condition from From_Typ
-- to To_Typ. Flag Parent_To_Derivation should be set when the context is
-- the creation of a derived type. Flag Private_To_Full_View should be set
-- when processing both views of a private type.
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_Components (Typ : Entity_Id; Decl : Node_Id);
-- Subsidiary to Build_Derived_Record_Type. For untagged records, we
-- build a copy of the declaration tree of the parent, and we create
-- independently the list of components for the derived type. Semantic
-- information uses the component entities, but record representation
-- clauses are validated on the declaration tree. This procedure replaces
-- discriminants and components in the declaration with those that have
-- been created by Inherit_Components.
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
Check_SPARK_05_Restriction ("access type is not allowed", N);
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_In (Related_Nod, 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_In (Par, 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 is 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
-- Compiler runtime units are compiled in Ada 2005 mode when building
-- the runtime library but must also be compilable in Ada 95 mode
-- (when bootstrapping the compiler).
Check_Compiler_Unit ("anonymous access to subprogram", N);
Access_Subprogram_Declaration
(T_Name => Anon_Type,
T_Def => Access_To_Subprogram_Definition (N));
if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
Set_Ekind
(Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
else
Set_Ekind (Anon_Type, E_Anonymous_Access_Subprogram_Type);
end if;
Set_Can_Use_Internal_Rep
(Anon_Type, not Always_Compatible_Rep_On_Target);
-- 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;
-- Ada 2005: If the designated type is an interface that may contain
-- tasks, 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 Nkind (Related_Nod) = N_Object_Declaration and then Expander_Active
then
if Is_Interface (Desig_Type) and then Is_Limited_Record (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 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));
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
Check_SPARK_05_Restriction ("access type is not allowed", T_Def);
-- 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 not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
N_Private_Type_Declaration,
N_Private_Extension_Declaration,
N_Procedure_Specification,
N_Function_Specification,
N_Entry_Body)
or else
Nkind_In (D_Ityp, 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_In (D_Ityp, N_Procedure_Specification,
N_Function_Specification)
then
Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
elsif Nkind_In (D_Ityp, 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);
-- In ASIS mode, the access_to_subprogram may be analyzed twice,
-- when it is part of an unconstrained type and subtype expansion
-- is disabled. To avoid back-end problems with shared profiles,
-- use previous subprogram type as the designated type, and then
-- remove scope added above.
if ASIS_Mode and then Present (Scope (Defining_Identifier (F)))
then
Set_Etype (T_Name, T_Name);
Init_Size_Align (T_Name);
Set_Directly_Designated_Type (T_Name,
Scope (Defining_Identifier (F)));
End_Scope;
return;
end if;
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
Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
Set_Convention (Desig_Type, Convention_Protected);
else
Set_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);
Init_Size_Align (T_Name);
Set_Directly_Designated_Type (T_Name, Desig_Type);
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);
end Access_Subprogram_Declaration;
----------------------------
-- Access_Type_Declaration --
----------------------------
procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
P : constant Node_Id := Parent (Def);
S : constant Node_Id := Subtype_Indication (Def);
Full_Desig : Entity_Id;
begin
Check_SPARK_05_Restriction ("access type is not allowed", Def);
-- Check for permissible use of incomplete type
if Nkind (S) /= N_Subtype_Indication then
Analyze (S);
if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
Set_Directly_Designated_Type (T, 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
Set_Ekind (T, E_Access_Type);
Build_Master_Entity (T);
Build_Master_Renaming (T);
end if;
else
Set_Directly_Designated_Type (T, 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
Set_Directly_Designated_Type (T,
Process_Subtype (S, P, T, 'P'));
end if;
if All_Present (Def) or Constant_Present (Def) then
Set_Ekind (T, E_General_Access_Type);
else
Set_Ekind (T, E_Access_Type);
end if;
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 classwide type", S);
-- Clean up indication of tagged status to prevent cascaded errors
Set_Is_Tagged_Type (T, False);
end if;
Set_Etype (T, T);
-- 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
Init_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_Controlled_Component (T, False);
Set_Has_Protected (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);
Set_Ekind (Tag, E_Component);
Set_Is_Tag (Tag);
Set_Is_Aliased (Tag);
Set_Related_Type (Tag, Iface);
Init_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);
Set_Ekind (Offset, E_Component);
Set_Is_Aliased (Offset);
Set_Related_Type (Offset, Iface);
Init_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
("(Ada 2005) interface types not supported by this run-time!",
Sloc (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);
-- 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
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.
elsif R /= P and then Is_Limited_Record (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);
if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
Check_SPARK_05_Restriction ("subtype mark required", Typ);
end if;
-- 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
Check_SPARK_05_Restriction ("default expression is not allowed", E);
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 Is_Indefinite_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);
Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
-- 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;
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 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 immedately analyzed.
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 declarations.
-----------------
-- 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;
--------------------------------------
-- 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 not Nam_In (Chars (Body_Id), 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_In (Spec_Id, 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);
Insert_Before_And_Analyze (Body_Decl,
Make_Subprogram_Declaration (Loc, Specification => Spec));
end Handle_Late_Controlled_Primitive;
--------------------------------
-- 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;
-- Local variables
Context : Node_Id;
Freeze_From : Entity_Id := Empty;
Next_Decl : Node_Id;
Spec_Id : Entity_Id;
Body_Seen : Boolean := False;
-- Flag set when the first body [stub] is encountered
In_Package_Body : Boolean := False;
-- Flag set when the current declaration list belongs to a package body
-- Start of processing for Analyze_Declarations
begin
if Restriction_Check_Required (SPARK_05) then
Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
end if;
Decl := First (L);
while Present (Decl) loop
-- Package spec cannot contain a package declaration in SPARK
if Nkind (Decl) = N_Package_Declaration
and then Nkind (Parent (L)) = N_Package_Specification
then
Check_SPARK_05_Restriction
("package specification cannot contain a package declaration",
Decl);
end if;
-- Complete analysis of declaration
Analyze (Decl);
Next_Decl := Next (Decl);
if No (Freeze_From) then
Freeze_From := First_Entity (Current_Scope);
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_In (Parent (L), N_Component_List,
N_Task_Definition,
N_Protected_Definition)
then
null;
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;
Freeze_All (First_Entity (Current_Scope), Decl);
Freeze_From := Last_Entity (Current_Scope);
elsif Scope (Current_Scope) /= Standard_Standard
and then not Is_Child_Unit (Current_Scope)
and then No (Generic_Parent (Parent (L)))
then
null;
elsif L /= Visible_Declarations (Parent (L))
or else No (Private_Declarations (Parent (L)))
or else Is_Empty_List (Private_Declarations (Parent (L)))
then
Adjust_Decl;
Freeze_All (First_Entity (Current_Scope), Decl);
Freeze_From := Last_Entity (Current_Scope);
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.
elsif not Analyzed (Next_Decl) and then Is_Body (Next_Decl) 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 and 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.
-- The spec of the late primitive is not generated in ASIS mode to
-- ensure a consistent list of primitives that indicates the true
-- semantic structure of the program (which is not relevant when
-- generating executable code.
-- ??? a cleaner approach may be possible and/or this solution
-- could be extended to general-purpose late primitives, TBD.
if not ASIS_Mode and then not Body_Seen and then not Is_Body (Decl)
then
Body_Seen := True;
if Nkind (Next_Decl) = N_Subprogram_Body then
Handle_Late_Controlled_Primitive (Next_Decl);
end if;
end if;
Adjust_Decl;
Freeze_All (Freeze_From, Decl);
Freeze_From := Last_Entity (Current_Scope);
end if;
Decl := Next_Decl;
end loop;
-- Analyze the contracts of packages and their bodies
if Present (L) then
Context := Parent (L);
if Nkind (Context) = N_Package_Specification then
-- When a package has private declarations, its contract must be
-- analyzed at the end of the said declarations. This way both the
-- analysis and freeze actions are properly synchronized in case
-- of private type use within the contract.
if L = Private_Declarations (Context) then
Analyze_Package_Contract (Defining_Entity (Context));
-- Build the bodies of the default initial condition procedures
-- for all types subject to pragma Default_Initial_Condition.
-- From a purely Ada stand point, this is a freezing activity,
-- however freezing is not available under GNATprove_Mode. To
-- accomodate both scenarios, the bodies are build at the end
-- of private declaration analysis.
Build_Default_Init_Cond_Procedure_Bodies (L);
-- Otherwise the contract is analyzed at the end of the visible
-- declarations.
elsif L = Visible_Declarations (Context)
and then No (Private_Declarations (Context))
then
Analyze_Package_Contract (Defining_Entity (Context));
end if;
elsif Nkind (Context) = N_Package_Body then
In_Package_Body := True;
Spec_Id := Corresponding_Spec (Context);
Analyze_Package_Body_Contract (Defining_Entity (Context));
end if;
end if;
-- Analyze the contracts of subprogram declarations, subprogram bodies
-- and variables now due to the delayed visibility requirements of their
-- aspects.
Decl := First (L);
while Present (Decl) loop
if Nkind (Decl) = N_Object_Declaration then
Analyze_Object_Contract (Defining_Entity (Decl));
elsif Nkind_In (Decl, N_Abstract_Subprogram_Declaration,
N_Generic_Subprogram_Declaration,
N_Subprogram_Declaration)
then
Analyze_Subprogram_Contract (Defining_Entity (Decl));
elsif Nkind (Decl) = N_Subprogram_Body then
Analyze_Subprogram_Body_Contract (Defining_Entity (Decl));
elsif Nkind (Decl) = N_Subprogram_Body_Stub then
Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl));
end if;
Next (Decl);
end loop;
-- State refinements are visible upto the end the of the package body
-- declarations. Hide the refinements from visibility to restore the
-- original state conditions.
if In_Package_Body then
Remove_Visible_Refinements (Spec_Id);
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_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_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)
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 type declaration may be subject to pragma Ghost with policy
-- Ignore. Set the mode now to ensure that any nodes generated during
-- analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N, Prev);
-- 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, Parent (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, unless we are in
-- SPARK.
when N_Record_Definition =>
if Present (Discriminant_Specifications (N)) then
Check_SPARK_05_Restriction
("discriminant type is not allowed",
Defining_Identifier
(First (Discriminant_Specifications (N))));
end if;
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);
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);
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);
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;
-- Controlled type is not allowed in SPARK
if Is_Visibly_Controlled (T) then
Check_SPARK_05_Restriction ("controlled type is not allowed", N);
end if;
-- A type declared within a Ghost region is automatically Ghost
-- (SPARK RM 6.9(2)).
if Comes_From_Source (T) and then Ghost_Mode > None then
Set_Is_Ghost_Entity (T);
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 Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))
then
Set_Is_Descendent_Of_Address (Def_Id);
Set_Is_Descendent_Of_Address (Base_Type (Def_Id));
Set_Is_Descendent_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;
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
Check_SPARK_05_Restriction ("incomplete type is not allowed", N);
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);
Set_Ekind (T, E_Incomplete_Type);
Init_Size_Align (T);
Set_Is_First_Subtype (T, True);
Set_Etype (T, T);
-- An incomplete type declared within a Ghost region is automatically
-- Ghost (SPARK RM 6.9(2)).
if Ghost_Mode > None then
Set_Is_Ghost_Entity (T);
end if;
-- 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);
Set_Direct_Primitive_Operations (T, New_Elmt_List);
end if;
Push_Scope (T);
Set_Stored_Constraint (T, No_Elist);
if Present (Discriminant_Specifications (N)) then
Process_Discriminants (N);
end if;
End_Scope;
-- If the type has discriminants, non-trivial 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 VM_Target = No_VM
and then (Is_Task_Interface (T)
or else Is_Protected_Interface (T)
or else Is_Synchronized_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
Id : constant Entity_Id := Defining_Identifier (N);
E : constant Node_Id := Expression (N);
T : Entity_Id;
Index : Interp_Index;
It : Interp;
begin
-- The number declaration may be subject to pragma Ghost with policy
-- Ignore. Set the mode now to ensure that any nodes generated during
-- analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
Generate_Definition (Id);
Enter_Name (Id);
-- A number declared within a Ghost region is automatically Ghost
-- (SPARK RM 6.9(2)).
if Ghost_Mode > None then
Set_Is_Ghost_Entity (Id);
end if;
-- 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);
Set_Ekind (Id, E_Named_Integer);
Set_Is_Frozen (Id, True);
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 It.Typ = Universal_Real
or else
It.Typ = Universal_Integer
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);
Set_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);
Set_Ekind (Id, E_Named_Real);
else
Wrong_Type (E, Any_Numeric);
Resolve (E, T);
Set_Etype (Id, T);
Set_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
return;
end if;
if Nkind_In (E, 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;
end Analyze_Number_Declaration;
-----------------------------
-- Analyze_Object_Contract --
-----------------------------
procedure Analyze_Object_Contract (Obj_Id : Entity_Id) is
Obj_Typ : constant Entity_Id := Etype (Obj_Id);
AR_Val : Boolean := False;
AW_Val : Boolean := False;
ER_Val : Boolean := False;
EW_Val : Boolean := False;
Prag : Node_Id;
Seen : Boolean := False;
begin
-- The loop parameter in an element iterator over a formal container
-- is declared with an object declaration but no contracts apply.
if Ekind (Obj_Id) = E_Loop_Parameter then
return;
end if;
if Ekind (Obj_Id) = E_Constant then
-- A constant cannot be effectively volatile. This check is only
-- relevant with SPARK_Mode on as it is not a standard Ada legality
-- rule. Do not flag internally-generated constants that map generic
-- formals to actuals in instantiations (SPARK RM 7.1.3(6)).
if SPARK_Mode = On
and then Is_Effectively_Volatile (Obj_Id)
and then No (Corresponding_Generic_Association (Parent (Obj_Id)))
-- Don't give this for internally generated entities (such as the
-- FIRST and LAST temporaries generated for bounds).
and then Comes_From_Source (Obj_Id)
then
Error_Msg_N ("constant cannot be volatile", Obj_Id);
end if;
else pragma Assert (Ekind (Obj_Id) = E_Variable);
-- The following checks are only relevant when SPARK_Mode is on as
-- they are not standard Ada legality rules. Internally generated
-- temporaries are ignored.
if SPARK_Mode = On and then Comes_From_Source (Obj_Id) then
if Is_Effectively_Volatile (Obj_Id) then
-- The declaration of an effectively volatile object must
-- appear at the library level (SPARK RM 7.1.3(7), C.6(6)).
if not Is_Library_Level_Entity (Obj_Id) then
Error_Msg_N
("volatile variable & must be declared at library level",
Obj_Id);
-- An object of a discriminated type cannot be effectively
-- volatile (SPARK RM C.6(4)).
elsif Has_Discriminants (Obj_Typ) then
Error_Msg_N
("discriminated object & cannot be volatile", Obj_Id);
-- An object of a tagged type cannot be effectively volatile
-- (SPARK RM C.6(5)).
elsif Is_Tagged_Type (Obj_Typ) then
Error_Msg_N ("tagged object & cannot be volatile", Obj_Id);
end if;
-- The object is not effectively volatile
else
-- A non-effectively volatile object cannot have effectively
-- volatile components (SPARK RM 7.1.3(7)).
if not Is_Effectively_Volatile (Obj_Id)
and then Has_Volatile_Component (Obj_Typ)
then
Error_Msg_N
("non-volatile object & cannot have volatile components",
Obj_Id);
end if;
end if;
end if;
if Is_Ghost_Entity (Obj_Id) then
-- A Ghost object cannot be effectively volatile (SPARK RM 6.9(8))
if Is_Effectively_Volatile (Obj_Id) then
Error_Msg_N ("ghost variable & cannot be volatile", Obj_Id);
-- A Ghost object cannot be imported or exported (SPARK RM 6.9(8))
elsif Is_Imported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be imported", Obj_Id);
elsif Is_Exported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be exported", Obj_Id);
end if;
end if;
-- Analyze all external properties
Prag := Get_Pragma (Obj_Id, Pragma_Async_Readers);
if Present (Prag) then
Analyze_External_Property_In_Decl_Part (Prag, AR_Val);
Seen := True;
end if;
Prag := Get_Pragma (Obj_Id, Pragma_Async_Writers);
if Present (Prag) then
Analyze_External_Property_In_Decl_Part (Prag, AW_Val);
Seen := True;
end if;
Prag := Get_Pragma (Obj_Id, Pragma_Effective_Reads);
if Present (Prag) then
Analyze_External_Property_In_Decl_Part (Prag, ER_Val);
Seen := True;
end if;
Prag := Get_Pragma (Obj_Id, Pragma_Effective_Writes);
if Present (Prag) then
Analyze_External_Property_In_Decl_Part (Prag, EW_Val);
Seen := True;
end if;
-- Verify the mutual interaction of the various external properties
if Seen then
Check_External_Properties (Obj_Id, AR_Val, AW_Val, ER_Val, EW_Val);
end if;
-- Check whether the lack of indicator Part_Of agrees with the
-- placement of the variable with respect to the state space.
Prag := Get_Pragma (Obj_Id, Pragma_Part_Of);
if No (Prag) then
Check_Missing_Part_Of (Obj_Id);
end if;
end if;
-- A ghost object cannot be imported or exported (SPARK RM 6.9(8))
if Is_Ghost_Entity (Obj_Id) then
if Is_Exported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be exported", Obj_Id);
elsif Is_Imported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be imported", Obj_Id);
end if;
end if;
end Analyze_Object_Contract;
--------------------------------
-- Analyze_Object_Declaration --
--------------------------------
procedure Analyze_Object_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
Act_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.
Prev_Entity : Entity_Id := Empty;
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_Tasks is set
-- for T). As a side effect, if an array of tasks with non-static bounds
-- or a variant record type is encountered, Check_Restrictions is called
-- indicating the count is unknown.
-----------------
-- 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;
-- 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))))
then
Prev_Entity := Empty;
end if;
end if;
-- The object declaration may be subject to pragma Ghost with policy
-- Ignore. Set the mode now to ensure that any nodes generated during
-- analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N, Prev_Entity);
if Present (Prev_Entity) then
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);
Set_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);
Set_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 and then Can_Never_Be_Null (T) 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 Present (Expression (N))
and then Nkind (Expression (N)) = N_Aggregate
then
null;
else
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;
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;
-- Special checks for protected objects not at library level
if Is_Protected_Type (T)
and then not Is_Library_Level_Entity (Id)
then
Check_Restriction (No_Local_Protected_Objects, Id);
-- Protected objects with interrupt handlers must be at library level
-- Ada 2005: This test is not needed (and the corresponding clause
-- in the RM is removed) because accessibility checks are sufficient
-- to make handlers not at the library level illegal.
-- AI05-0303: The AI is in fact a binding interpretation, and thus
-- applies to the '95 version of the language as well.
if Has_Interrupt_Handler (T) and then Ada_Version < Ada_95 then
Error_Msg_N
("interrupt object can only be declared at library level", Id);
end if;
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;
-- These checks should be performed before the initialization expression
-- is considered, so that the Object_Definition node is still the same
-- as in source code.
-- In SPARK, the nominal subtype is always given by a subtype mark
-- and must not be unconstrained. (The only exception to this is the
-- acceptance of declarations of constants of type String.)
if not Nkind_In (Object_Definition (N), N_Expanded_Name, N_Identifier)
then
Check_SPARK_05_Restriction
("subtype mark required", Object_Definition (N));
elsif Is_Array_Type (T)
and then not Is_Constrained (T)
and then T /= Standard_String
then
Check_SPARK_05_Restriction
("subtype mark of constrained type expected",
Object_Definition (N));
end if;
-- There are no aliased objects in SPARK
if Aliased_Present (N) then
Check_SPARK_05_Restriction ("aliased object is not allowed", N);
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.
if Comes_From_Source (N)
and then Expander_Active
and then Nkind (E) = N_Aggregate
and then Present (Following_Address_Clause (N))
then
Set_Etype (E, T);
else
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
return;
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 other than Any_Access in order to keep gigi happy.
if Etype (E) = Any_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);
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);
if Nkind (Original_Node (N)) = N_Object_Declaration
and then Comes_From_Source (Original_Node (N))
-- Only call test if needed
and then Restriction_Check_Required (SPARK_05)
and then not Is_SPARK_05_Initialization_Expr (Original_Node (E))
then
Check_SPARK_05_Restriction
("initialization expression is not appropriate", E);
end if;
-- 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)).
if Is_Class_Wide_Type (T) and then Is_EVF_Expression (E) then
Error_Msg_N
("formal parameter with Extensions_Visible False cannot be "
& "implicitly converted to class-wide type", 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, 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
-- and then this is not an internal declaration whose initialization
-- comes later (as for an aggregate expansion).
if not Suppress_Assignment_Checks (N)
and then Present (Predicate_Function (T))
and then not No_Initialization (N)
and then
(Present (E)
or else
Is_Partially_Initialized_Type (T, Include_Implicit => False))
then
-- If the type has a static predicate and the expression is known at
-- compile time, see if the expression satisfies the predicate.
if Present (E) then
Check_Expression_Against_Static_Predicate (E, T);
end if;
Insert_After (N,
Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
end if;
-- Case of unconstrained type
if Is_Indefinite_Subtype (T) then
-- In SPARK, a declaration of unconstrained type is allowed
-- only for constants of type string.
if Is_String_Type (T) and then not Constant_Present (N) then
Check_SPARK_05_Restriction
("declaration of object of unconstrained type not allowed", N);
end if;
-- 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
-- Check restrictions in Ada 83
if not Constant_Present (N) then
-- Unconstrained variables not allowed in Ada 83 mode
if Ada_Version = Ada_83
and then Comes_From_Source (Object_Definition (N))
then
Error_Msg_N
("(Ada 83) unconstrained variable not allowed",
Object_Definition (N));
end if;
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;
-- In GNATprove mode, Expand_Subtype_From_Expr does nothing. Thus,
-- we should prevent the generation of another Itype with the
-- same name as the one already generated, or we end up with
-- two identical types in GNATprove.
elsif GNATprove_Mode 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
Set_Ekind (Id, E_Constant);
else
Set_Ekind (Id, E_Variable);
end if;
-- An object declared within a Ghost region is automatically
-- Ghost (SPARK RM 6.9(2)).
if Comes_From_Source (Id) and then Ghost_Mode > None then
Set_Is_Ghost_Entity (Id);
-- The Ghost policy in effect at the point of declaration
-- and at the point of completion must match
-- (SPARK RM 6.9(15)).
if Present (Prev_Entity)
and then Is_Ghost_Entity (Prev_Entity)
then
Check_Ghost_Completion (Prev_Entity, Id);
end if;
end if;
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);
return;
else
Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
Act_T := Find_Type_Of_Object (Object_Definition (N), N);
end if;
Set_Is_Constr_Subt_For_U_Nominal (Act_T);
if Aliased_Present (N) then
Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
end if;
Freeze_Before (N, Act_T);
Freeze_Before (N, T);
end if;
elsif Is_Array_Type (T)
and then No_Initialization (N)
and then Nkind (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);
if Aliased_Present (N) then
Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
end if;
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 not Is_Constrained (T) then
null;
elsif 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 (Choices (First (Component_Associations (E))))
and then Nkind (First
(Choices (First (Component_Associations (E))))) = N_Others_Choice
then
null;
else
Apply_Length_Check (E, T);
end if;
-- If the type is limited 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.
elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
and then not Is_Constrained (T)
and then Has_Discriminants (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 Constant_Present (N) then
Set_Ekind (Id, E_Constant);
Set_Is_True_Constant (Id);
else
Set_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;
-- Initialize alignment and size and capture alignment setting
Init_Alignment (Id);
Init_Esize (Id);
Set_Optimize_Alignment_Flags (Id);
-- An object declared within a Ghost region is automatically Ghost
-- (SPARK RM 6.9(2)).
if Comes_From_Source (Id)
and then (Ghost_Mode > None
or else (Present (Prev_Entity)
and then Is_Ghost_Entity (Prev_Entity)))
then
Set_Is_Ghost_Entity (Id);
-- The Ghost policy in effect at the point of declaration and at the
-- point of completion must match (SPARK RM 6.9(16)).
if Present (Prev_Entity) and then Is_Ghost_Entity (Prev_Entity) then
Check_Ghost_Completion (Prev_Entity, Id);
end if;
end if;
-- Deal with aliased case
if Aliased_Present (N) then
Set_Is_Aliased (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 Is_Indefinite_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,