Google Git
Sign in
gnu / gcc / 82b61df521d17a96f60e56ede06a55a8894b1c2e / . / gcc / ada / sem_ch3.adb
blob: 1a43f9ee7f3463a3ba5f708d5b7a829f28cbed2b [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 3 --
-- --
-- B o d y --
-- --
-- $Revision$
-- --
-- Copyright (C) 1992-2001, 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
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_Dist; use Exp_Dist;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
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 Rtsfind; use Rtsfind;
with Sem; use Sem;
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_Ch13; use Sem_Ch13;
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_Res; use Sem_Res;
with Sem_Smem; use Sem_Smem;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
package body Sem_Ch3 is
-----------------------
-- Local Subprograms --
-----------------------
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 (ie 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 pro-
-- tected 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_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);
-- Substidiary 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 to Build_Derived_Type and
-- Analyze_Private_Extension_Declaration used for tagged and untagged
-- record types. 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).
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:
-- (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 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. 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 if we are 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;
Loc : Source_Ptr)
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_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_Incomplete (T : Entity_Id);
-- Called to verify that an incomplete type is not used prematurely
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_Or_Process_Discriminants (N : Node_Id; T : Entity_Id);
-- If T is the full declaration of an incomplete or private type, check
-- the conformance of the discriminants, otherwise process them.
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.
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.
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
(Compon_Type : 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 constraint
-- Constraints for Typ and the type of a component of Typ, Compon_Type,
-- create and return the type corresponding to Compon_type where all
-- discriminant references are replaced with the corresponding
-- constraint. If no discriminant references occurr in Compon_Typ then
-- return it as is. Constrained_Typ is the final constrained subtype to
-- which the constrained Compon_Type belongs. Related_Node is the node
-- where we will attach all the itypes created.
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). 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;
Related_Id : Entity_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;
Related_Nod : 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_Discrimated_Subtype for an explanation
-- of For_Access.
procedure Constrain_Enumeration
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : 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;
Related_Nod : 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 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;
Related_Nod : Node_Id);
-- Build subtype of a signed or modular integer type.
procedure Constrain_Ordinary_Fixed
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : 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 (Privat, Full : Entity_Id);
-- Copy the Privat 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 Copy_Private_To_Full (Priv, Full : Entity_Id);
-- Initialize the full view declaration with the relevant fields
-- from the private view.
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 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. This routine will invoke
-- Build_Derived_Type 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.
function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
-- Given a subtype indication S (which is really an N_Subtype_Indication
-- node or a plain N_Identifier), find the type of the subtype mark.
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.
procedure Expand_Others_Choice
(Case_Table : Choice_Table_Type;
Others_Choice : Node_Id;
Choice_Type : Entity_Id);
-- In the case of a variant part of a record type that has an OTHERS
-- choice, this procedure expands the OTHERS into the actual choices
-- that it represents. This new list of choice nodes is attached to
-- the OTHERS node via the Others_Discrete_Choices field. The Case_Table
-- contains all choices that have been given explicitly in the variant.
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 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 and is
-- a power of two (implementation restriction).
procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id);
-- Create an abbreviated declaration for an operator in order to
-- materialize minimally operators on derived 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 Record_Type_Declaration (T : Entity_Id; N : Node_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.
procedure Record_Type_Definition (Def : Node_Id; 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. 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.
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;
Related_Nod : Node_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 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.
-----------------------
-- Access_Definition --
-----------------------
function Access_Definition
(Related_Nod : Node_Id;
N : Node_Id)
return Entity_Id
is
Anon_Type : constant Entity_Id :=
Create_Itype (E_Anonymous_Access_Type, Related_Nod,
Scope_Id => Scope (Current_Scope));
Desig_Type : Entity_Id;
begin
if Is_Entry (Current_Scope)
and then Is_Task_Type (Etype (Scope (Current_Scope)))
then
Error_Msg_N ("task entries cannot have access parameters", N);
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);
Init_Size_Align (Anon_Type);
Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
-- 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)));
Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
-- The context is either a subprogram 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 Ekind (Desig_Type) = E_Incomplete_Type
and then Is_Overloadable (Current_Scope)
then
Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
Set_Has_Delayed_Freeze (Current_Scope);
end if;
return Anon_Type;
end Access_Definition;
-----------------------------------
-- Access_Subprogram_Declaration --
-----------------------------------
procedure Access_Subprogram_Declaration
(T_Name : Entity_Id;
T_Def : Node_Id)
is
Formals : constant List_Id := Parameter_Specifications (T_Def);
Formal : Entity_Id;
Desig_Type : constant Entity_Id :=
Create_Itype (E_Subprogram_Type, Parent (T_Def));
begin
if Nkind (T_Def) = N_Access_Function_Definition then
Analyze (Subtype_Mark (T_Def));
Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def)));
else
Set_Etype (Desig_Type, Standard_Void_Type);
end if;
if Present (Formals) then
New_Scope (Desig_Type);
Process_Formals (Desig_Type, Formals, Parent (T_Def));
-- A bit of a kludge here, 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 ???
-- If and when Itypes have proper parent pointers to their
-- declarations, this kludge can be removed.
Set_Parent (Desig_Type, T_Name);
End_Scope;
Set_Parent (Desig_Type, Empty);
end if;
-- 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.
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
then
Error_Msg_N ("functions can only have IN parameters", Formal);
end if;
if Ekind (Etype (Formal)) = E_Incomplete_Type then
Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
Set_Has_Delayed_Freeze (Desig_Type);
end if;
Next_Formal (Formal);
end loop;
end if;
if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
and then not Has_Delayed_Freeze (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_Etype (T_Name, T_Name);
Init_Size_Align (T_Name);
Set_Directly_Designated_Type (T_Name, Desig_Type);
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
S : constant Node_Id := Subtype_Indication (Def);
P : constant Node_Id := Parent (Def);
begin
-- 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));
else
Set_Directly_Designated_Type (T,
Process_Subtype (S, P, T, 'P'));
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;
if Base_Type (Designated_Type (T)) = T then
Error_Msg_N ("access type cannot designate itself", S);
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_With_Type (T) then
Init_Size_Align (T);
end if;
Set_Is_Access_Constant (T, Constant_Present (Def));
-- If designated type is an imported tagged type, indicate that the
-- access type is also imported, and therefore restricted in its use.
-- The access type may already be imported, so keep setting otherwise.
if From_With_Type (Designated_Type (T)) then
Set_From_With_Type (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.
Set_Has_Task (T, False);
Set_Has_Controlled_Component (T, False);
end Access_Type_Declaration;
-----------------------------------
-- Analyze_Component_Declaration --
-----------------------------------
procedure Analyze_Component_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
P : Entity_Id;
begin
Generate_Definition (Id);
Enter_Name (Id);
T := Find_Type_Of_Object (Subtype_Indication (N), N);
-- 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 Expressions" in the spec of package Sem).
if Present (Expression (N)) then
Analyze_Default_Expression (Expression (N), T);
Check_Initialization (T, Expression (N));
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
Error_Msg_N
("unconstrained subtype in component declaration",
Subtype_Indication (N));
-- Components cannot be abstract, except for the special case of
-- the _Parent field (case of extending an abstract tagged type)
elsif Is_Abstract (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 (N));
-- If the 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_Limited_Record (Root_Type (Current_Scope))
then
Error_Msg_N
("extension of nonlimited type cannot have limited components",
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)
then
Error_Msg_N ("nonlimited type cannot have limited components", N);
Set_Etype (Id, Any_Type);
Set_Is_Limited_Composite (Current_Scope, False);
end if;
end if;
Set_Original_Record_Component (Id, Id);
end Analyze_Component_Declaration;
--------------------------
-- Analyze_Declarations --
--------------------------
procedure Analyze_Declarations (L : List_Id) is
D : Node_Id;
Next_Node : Node_Id;
Freeze_From : Entity_Id := Empty;
procedure Adjust_D;
-- Adjust D not to include implicit label declarations, since these
-- have strange Sloc values that result in elaboration check problems.
procedure Adjust_D is
begin
while Present (Prev (D))
and then Nkind (D) = N_Implicit_Label_Declaration
loop
Prev (D);
end loop;
end Adjust_D;
-- Start of processing for Analyze_Declarations
begin
D := First (L);
while Present (D) loop
-- Complete analysis of declaration
Analyze (D);
Next_Node := Next (D);
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 a
-- 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_Node) then
if Nkind (Parent (L)) = N_Component_List
or else Nkind (Parent (L)) = N_Task_Definition
or else Nkind (Parent (L)) = 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;
Adjust_D;
Freeze_All (Freeze_From, D);
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_D;
Freeze_All (Freeze_From, D);
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 expander generated bodies, which can
-- be recognized by their already being analyzed. The expander
-- ensures that all types needed by these bodies have been frozen
-- but it is not necessary to freeze all types (and would be wrong
-- since it would not correspond to an RM defined freeze point).
elsif not Analyzed (Next_Node)
and then (Nkind (Next_Node) = N_Subprogram_Body
or else Nkind (Next_Node) = N_Entry_Body
or else Nkind (Next_Node) = N_Package_Body
or else Nkind (Next_Node) = N_Protected_Body
or else Nkind (Next_Node) = N_Task_Body
or else Nkind (Next_Node) in N_Body_Stub)
then
Adjust_D;
Freeze_All (Freeze_From, D);
Freeze_From := Last_Entity (Current_Scope);
end if;
D := Next_Node;
end loop;
end Analyze_Declarations;
--------------------------------
-- Analyze_Default_Expression --
--------------------------------
procedure Analyze_Default_Expression (N : Node_Id; T : Entity_Id) is
Save_In_Default_Expression : constant Boolean := In_Default_Expression;
begin
In_Default_Expression := True;
Pre_Analyze_And_Resolve (N, T);
In_Default_Expression := Save_In_Default_Expression;
end Analyze_Default_Expression;
----------------------------------
-- Analyze_Incomplete_Type_Decl --
----------------------------------
procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
F : constant Boolean := Is_Pure (Current_Scope);
T : Entity_Id;
begin
Generate_Definition (Defining_Identifier (N));
-- Process an incomplete declaration. The identifier must not have been
-- declared already in the scope. However, an incomplete declaration may
-- appear in the private part of a package, for a private type that has
-- already been declared.
-- In this case, the discriminants (if any) must match.
T := Find_Type_Name (N);
Set_Ekind (T, E_Incomplete_Type);
Init_Size_Align (T);
Set_Is_First_Subtype (T, True);
Set_Etype (T, T);
New_Scope (T);
Set_Girder_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
-- 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_Itype_Reference --
-----------------------------
-- Nothing to do. This node is placed in the tree only for the benefit
-- of Gigi 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
Generate_Definition (Id);
Enter_Name (Id);
-- This is an optimization of a common case of an integer literal
if Nkind (E) = N_Integer_Literal then
Set_Is_Static_Expression (E, True);
Set_Etype (E, Universal_Integer);
Set_Etype (Id, Universal_Integer);
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);
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_Not_Source_Assigned (Id, True);
Set_Is_True_Constant (Id, True);
return;
end if;
if Nkind (E) = N_Integer_Literal
or else Nkind (E) = N_Real_Literal
then
Set_Etype (E, Etype (Id));
end if;
if not Is_OK_Static_Expression (E) then
Error_Msg_N ("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_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 Build_Default_Subtype return Entity_Id;
-- If the object is limited or aliased, and if the type is unconstrained
-- and there is no expression, the discriminants cannot be modified and
-- the subtype of the object is constrained by the defaults, so it is
-- worthile building the corresponding subtype.
---------------------------
-- Build_Default_Subtype --
---------------------------
function Build_Default_Subtype return Entity_Id is
Act : Entity_Id;
Constraints : List_Id := New_List;
Decl : Node_Id;
Disc : Entity_Id;
begin
Disc := First_Discriminant (T);
if No (Discriminant_Default_Value (Disc)) then
return T; -- previous error.
end if;
Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
while Present (Disc) loop
Append (
New_Copy_Tree (
Discriminant_Default_Value (Disc)), Constraints);
Next_Discriminant (Disc);
end loop;
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Act,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (T, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint
(Loc, Constraints)));
Insert_Before (N, Decl);
Analyze (Decl);
return Act;
end Build_Default_Subtype;
-- Start of processing for Analyze_Object_Declaration
begin
-- There are three kinds of implicit types generated by an
-- object declaration:
-- 1. Those for generated by the original Object Definition
-- 2. Those generated by the Expression
-- 3. Those used to constrained the Object Definition with the
-- expression constraints when it 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 homograph is an implicit subprogram, it is overridden by the
-- current declaration.
if Present (Prev_Entity)
and then Is_Overloadable (Prev_Entity)
and then Is_Inherited_Operation (Prev_Entity)
then
Prev_Entity := Empty;
end if;
end if;
if Present (Prev_Entity) then
Constant_Redeclaration (Id, N, T);
Generate_Reference (Prev_Entity, Id, 'c');
-- If in main unit, set as referenced, so we do not complain about
-- the full declaration being an unreferenced entity.
if In_Extended_Main_Source_Unit (Id) then
Set_Referenced (Id);
end if;
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);
return;
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);
T := Find_Type_Of_Object (Object_Definition (N), N);
if Error_Posted (Id) then
Set_Etype (Id, T);
Set_Ekind (Id, E_Variable);
return;
end if;
end if;
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.
if Constant_Present (N)
and then No (E)
then
if not Is_Package (Current_Scope)
or else In_Private_Part (Current_Scope)
then
Error_Msg_N
("invalid context for deferred constant declaration", 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_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 object declaration freezes its type
else
Check_Fully_Declared (T, N);
Freeze_Before (N, T);
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
if Has_Interrupt_Handler (T) 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;
-- Process initialization expression if present and not in error
if Present (E) and then E /= Error then
Analyze (E);
if not Assignment_OK (N) then
Check_Initialization (T, E);
end if;
Resolve (E, T);
-- Check for library level object that will require implicit
-- heap allocation.
if Is_Array_Type (T)
and then not Size_Known_At_Compile_Time (T)
and then Is_Library_Level_Entity (Id)
then
-- String literals are always allowed
if T = Standard_String
and then Nkind (E) = N_String_Literal
then
null;
-- Otherwise we do not allow this since it may cause an
-- implicit heap allocation.
else
Check_Restriction
(No_Implicit_Heap_Allocations, Object_Definition (N));
end if;
end if;
-- Check incorrect use of dynamically tagged expressions. Note
-- the use of Is_Tagged_Type (T) which seems redundant but is in
-- fact important to avoid spurious errors due to expanded code
-- for dispatching functions over an anonymous access type
if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
and then Is_Tagged_Type (T)
and then not Is_Class_Wide_Type (T)
then
Error_Msg_N ("dynamically tagged expression not allowed!", E);
end if;
Apply_Scalar_Range_Check (E, T);
Apply_Static_Length_Check (E, T);
end if;
-- Abstract type is never permitted for a variable or constant.
-- Note: we inhibit this check for objects that do not come from
-- source because there is at least one case (the expansion of
-- x'class'input where x is abstract) where we legitimately
-- generate an abstract object.
if Is_Abstract (T) and then Comes_From_Source (N) then
Error_Msg_N ("type of object cannot be abstract",
Object_Definition (N));
if Is_CPP_Class (T) then
Error_Msg_NE ("\} may need a cpp_constructor",
Object_Definition (N), T);
end if;
-- Case of unconstrained type
elsif Is_Indefinite_Subtype (T) then
-- Nothing to do in deferred constant case
if Constant_Present (N) and then No (E) then
null;
-- Case of no initialization present
elsif No (E) then
if No_Initialization (N) then
null;
elsif Is_Class_Wide_Type (T) then
Error_Msg_N
("initialization required in class-wide declaration ", N);
else
Error_Msg_N
("unconstrained subtype not allowed (need initialization)",
Object_Definition (N));
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
-- Not allowed in Ada 83
if not Constant_Present (N) then
if 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);
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);
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;
elsif (Is_Limited_Record (T)
or else Is_Concurrent_Type (T))
and then not Is_Constrained (T)
and then Has_Discriminants (T)
then
Act_T := Build_Default_Subtype;
Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
elsif not Is_Constrained (T)
and then Has_Discriminants (T)
and then Constant_Present (N)
and then Nkind (E) = N_Function_Call
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 for the result of the call.
-- It is unclear why this should make it acceptable to gcc. ???
Remove_Side_Effects (E);
end if;
if T = Standard_Wide_Character
or else Root_Type (T) = Standard_Wide_String
then
Check_Restriction (No_Wide_Characters, Object_Definition (N));
end if;
-- Now establish the proper kind and type of the object
if Constant_Present (N) then
Set_Ekind (Id, E_Constant);
Set_Not_Source_Assigned (Id, True);
Set_Is_True_Constant (Id, True);
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;
-- If an initializing expression is present, then the variable
-- is potentially a true constant if no further assignments are
-- present. The code generator can use this for optimization.
-- The flag will be reset if there are any assignments. We only
-- set this flag for non library level entities, since for any
-- library level entities, assignments could exist in other units.
if Present (E) then
if not Is_Library_Level_Entity (Id) then
-- For now we omit this, because it seems to cause some
-- problems. In particular, if you uncomment this out, then
-- test case 4427-002 will fail for unclear reasons ???
if False then
Set_Is_True_Constant (Id);
end if;
end if;
-- Case of no initializing expression present. If the type is not
-- fully initialized, then we set Not_Source_Assigned, since this
-- is a case of a potentially uninitialized object. Note that we
-- do not consider access variables to be fully initialized for
-- this purpose, since it still seems dubious if someone declares
-- an access variable and never assigns to it.
else
if Is_Access_Type (T)
or else not Is_Fully_Initialized_Type (T)
then
Set_Not_Source_Assigned (Id);
end if;
end if;
end if;
Init_Alignment (Id);
Init_Esize (Id);
if Aliased_Present (N) then
Set_Is_Aliased (Id);
if No (E)
and then Is_Record_Type (T)
and then not Is_Constrained (T)
and then Has_Discriminants (T)
then
Set_Actual_Subtype (Id, Build_Default_Subtype);
end if;
end if;
Set_Etype (Id, Act_T);
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;
-- Generate a warning when an initialization causes an obvious
-- ABE violation. If the init expression is a simple aggregate
-- there shouldn't be any initialize/adjust call generated. This
-- will be true as soon as aggregates are built in place when
-- possible. ??? at the moment we do not generate warnings for
-- temporaries created for those aggregates although a
-- Program_Error might be generated if compiled with -gnato
if Is_Controlled (Etype (Id))
and then Comes_From_Source (Id)
then
declare
BT : constant Entity_Id := Base_Type (Etype (Id));
Implicit_Call : Entity_Id;
function Is_Aggr (N : Node_Id) return Boolean;
-- Check that N is an aggregate
function Is_Aggr (N : Node_Id) return Boolean is
begin
case Nkind (Original_Node (N)) is
when N_Aggregate | N_Extension_Aggregate =>
return True;
when N_Qualified_Expression |
N_Type_Conversion |
N_Unchecked_Type_Conversion =>
return Is_Aggr (Expression (Original_Node (N)));
when others =>
return False;
end case;
end Is_Aggr;
begin
-- If no underlying type, we already are in an error situation
-- don't try to add a warning since we do not have access
-- prim-op list.
if No (Underlying_Type (BT)) then
Implicit_Call := Empty;
-- A generic type does not have usable primitive operators.
-- Initialization calls are built for instances.
elsif Is_Generic_Type (BT) then
Implicit_Call := Empty;
-- if the init expression is not an aggregate, an adjust
-- call will be generated
elsif Present (E) and then not Is_Aggr (E) then
Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
-- if no init expression and we are not in the deferred
-- constant case, an Initialize call will be generated
elsif No (E) and then not Constant_Present (N) then
Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
else
Implicit_Call := Empty;
end if;
end;
end if;
end if;
if Has_Task (Etype (Id)) then
if not Is_Library_Level_Entity (Id) then
Check_Restriction (No_Task_Hierarchy, N);
Check_Potentially_Blocking_Operation (N);
end if;
end if;
-- Some simple constant-propagation: if the expression is a constant
-- string initialized with a literal, share the literal. This avoids
-- a run-time copy.
if Present (E)
and then Is_Entity_Name (E)
and then Ekind (Entity (E)) = E_Constant
and then Base_Type (Etype (E)) = Standard_String
then
declare
Val : constant Node_Id := Constant_Value (Entity (E));
begin
if Present (Val)
and then Nkind (Val) = N_String_Literal
then
Rewrite (E, New_Copy (Val));
end if;
end;
end if;
-- Another optimization: if the nominal subtype is unconstrained and
-- the expression is a function call that returns and unconstrained
-- type, rewrite the declararation as a renaming of the result of the
-- call. The exceptions below are cases where the copy is expected,
-- either by the back end (Aliased case) or by the semantics, as for
-- initializing controlled types or copying tags for classwide types.
if Present (E)
and then Nkind (E) = N_Explicit_Dereference
and then Nkind (Original_Node (E)) = N_Function_Call
and then not Is_Library_Level_Entity (Id)
and then not Is_Constrained (T)
and then not Is_Aliased (Id)
and then not Is_Class_Wide_Type (T)
and then not Is_Controlled (T)
and then not Has_Controlled_Component (Base_Type (T))
and then Expander_Active
then
Rewrite (N,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Id,
Subtype_Mark => New_Occurrence_Of
(Base_Type (Etype (Id)), Loc),
Name => E));
Set_Renamed_Object (Id, E);
end if;
if Present (Prev_Entity)
and then Is_Frozen (Prev_Entity)
and then not Error_Posted (Id)
then
Error_Msg_N ("full constant declaration appears too late", N);
end if;
Check_Eliminated (Id);
end Analyze_Object_Declaration;
---------------------------
-- Analyze_Others_Choice --
---------------------------
-- Nothing to do for the others choice node itself, the semantic analysis
-- of the others choice will occur as part of the processing of the parent
procedure Analyze_Others_Choice (N : Node_Id) is
begin
null;
end Analyze_Others_Choice;
-------------------------------------------
-- Analyze_Private_Extension_Declaration --
-------------------------------------------
procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
T : Entity_Id := Defining_Identifier (N);
Indic : constant Node_Id := Subtype_Indication (N);
Parent_Type : Entity_Id;
Parent_Base : Entity_Id;
begin
Generate_Definition (T);
Enter_Name (T);
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
Parent_Base := Base_Type (Parent_Type);
if Parent_Type = Any_Type
or else Etype (Parent_Type) = Any_Type
then
Set_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
return;
elsif not Is_Tagged_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must be a tagged type ", Indic);
return;
elsif Ekind (Parent_Type) = E_Void
or else Ekind (Parent_Type) = E_Incomplete_Type
then
Error_Msg_N ("premature derivation of incomplete type", Indic);
return;
end if;
-- Perhaps the parent type should be changed to the class-wide type's
-- specific type in this case to prevent cascading errors ???
if Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must not be a class-wide type", Indic);
return;
end if;
if (not Is_Package (Current_Scope)
and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
or else In_Private_Part (Current_Scope)
then
Error_Msg_N ("invalid context for private extension", N);
end if;
-- Set common attributes
Set_Is_Pure (T, Is_Pure (Current_Scope));
Set_Scope (T, Current_Scope);
Set_Ekind (T, E_Record_Type_With_Private);
Init_Size_Align (T);
Set_Etype (T, Parent_Base);
Set_Has_Task (T, Has_Task (Parent_Base));
Set_Convention (T, Convention (Parent_Type));
Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
Set_Is_First_Subtype (T);
Make_Class_Wide_Type (T);
Build_Derived_Record_Type (N, Parent_Type, T);
end Analyze_Private_Extension_Declaration;
---------------------------------
-- Analyze_Subtype_Declaration --
---------------------------------
procedure Analyze_Subtype_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
R_Checks : Check_Result;
begin
Generate_Definition (Id);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
Init_Size_Align (Id);
-- The following guard condition on Enter_Name is to handle cases
-- where the defining identifier has already been entered into the
-- scope but the declaration as a whole needs to be analyzed.
-- This case in particular happens for derived enumeration types.
-- The derived enumeration type is processed as an inserted enumeration
-- type declaration followed by a rewritten subtype declaration. The
-- defining identifier, however, is entered into the name scope very
-- early in the processing of the original type declaration and
-- therefore needs to be avoided here, when the created subtype
-- declaration is analyzed. (See Build_Derived_Types)
-- This also happens when the full view of a private type is a
-- derived type with constraints. In this case the entity has been
-- introduced in the private declaration.
if Present (Etype (Id))
and then (Is_Private_Type (Etype (Id))
or else Is_Task_Type (Etype (Id))
or else Is_Rewrite_Substitution (N))
then
null;
else
Enter_Name (Id);
end if;
T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
-- Inherit common attributes
Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
Set_Is_Volatile (Id, Is_Volatile (T));
Set_Is_Atomic (Id, Is_Atomic (T));
-- In the case where there is no constraint given in the subtype
-- indication, Process_Subtype just returns the Subtype_Mark,
-- so its semantic attributes must be established here.
if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
Set_Etype (Id, Base_Type (T));
case Ekind (T) is
when Array_Kind =>
Set_Ekind (Id, E_Array_Subtype);
-- Shouldn't we call Copy_Array_Subtype_Attributes here???
Set_First_Index (Id, First_Index (T));
Set_Is_Aliased (Id, Is_Aliased (T));
Set_Is_Constrained (Id, Is_Constrained (T));
when Decimal_Fixed_Point_Kind =>
Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
Set_Digits_Value (Id, Digits_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Scale_Value (Id, Scale_Value (T));
Set_Small_Value (Id, Small_Value (T));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Enumeration_Kind =>
Set_Ekind (Id, E_Enumeration_Subtype);
Set_First_Literal (Id, First_Literal (Base_Type (T)));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Character_Type (Id, Is_Character_Type (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Ordinary_Fixed_Point_Kind =>
Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Small_Value (Id, Small_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Float_Kind =>
Set_Ekind (Id, E_Floating_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Digits_Value (Id, Digits_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
when Signed_Integer_Kind =>
Set_Ekind (Id, E_Signed_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Modular_Integer_Kind =>
Set_Ekind (Id, E_Modular_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Class_Wide_Kind =>
Set_Ekind (Id, E_Class_Wide_Subtype);
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
Set_Cloned_Subtype (Id, T);
Set_Is_Tagged_Type (Id, True);
Set_Has_Unknown_Discriminants
(Id, True);
if Ekind (T) = E_Class_Wide_Subtype then
Set_Equivalent_Type (Id, Equivalent_Type (T));
end if;
when E_Record_Type | E_Record_Subtype =>
Set_Ekind (Id, E_Record_Subtype);
if Ekind (T) = E_Record_Subtype
and then Present (Cloned_Subtype (T))
then
Set_Cloned_Subtype (Id, Cloned_Subtype (T));
else
Set_Cloned_Subtype (Id, T);
end if;
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Girder_Constraint_From_Discriminant_Constraint (Id);
elsif Has_Unknown_Discriminants (Id) then
Set_Discriminant_Constraint (Id, No_Elist);
end if;
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id);
Set_Is_Abstract (Id, Is_Abstract (T));
Set_Primitive_Operations
(Id, Primitive_Operations (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
end if;
when Private_Kind =>
Set_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Private_Dependents (Id, New_Elmt_List);
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id);
Set_Is_Abstract (Id, Is_Abstract (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
end if;
-- In general the attributes of the subtype of a private
-- type are the attributes of the partial view of parent.
-- However, the full view may be a discriminated type,
-- and the subtype must share the discriminant constraint
-- to generate correct calls to initialization procedures.
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Girder_Constraint_From_Discriminant_Constraint (Id);
elsif Present (Full_View (T))
and then Has_Discriminants (Full_View (T))
then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (Full_View (T)));
Set_Girder_Constraint_From_Discriminant_Constraint (Id);
-- This would seem semantically correct, but apparently
-- confuses the back-end (4412-009). To be explained ???
-- Set_Has_Discriminants (Id);
end if;
Prepare_Private_Subtype_Completion (Id, N);
when Access_Kind =>
Set_Ekind (Id, E_Access_Subtype);
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Access_Constant
(Id, Is_Access_Constant (T));
Set_Directly_Designated_Type
(Id, Designated_Type (T));
-- A Pure library_item must not contain the declaration of a
-- named access type, except within a subprogram, generic
-- subprogram, task unit, or protected unit (RM 10.2.1(16)).
if Comes_From_Source (Id)
and then In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
then
Error_Msg_N
("named access types not allowed in pure unit", N);
end if;
when Concurrent_Kind =>
Set_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Corresponding_Record_Type (Id,
Corresponding_Record_Type (T));
Set_First_Entity (Id, First_Entity (T));
Set_First_Private_Entity (Id, First_Private_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Last_Entity (Id, Last_Entity (T));
if Has_Discriminants (T) then
Set_Discriminant_Constraint (Id,
Discriminant_Constraint (T));
Set_Girder_Constraint_From_Discriminant_Constraint (Id);
end if;
-- If the subtype name denotes an incomplete type
-- an error was already reported by Process_Subtype.
when E_Incomplete_Type =>
Set_Etype (Id, Any_Type);
when others =>
raise Program_Error;
end case;
end if;
if Etype (Id) = Any_Type then
return;
end if;
-- Some common processing on all types
Set_Size_Info (Id, T);
Set_First_Rep_Item (Id, First_Rep_Item (T));
T := Etype (Id);
Set_Is_Immediately_Visible (Id, True);
Set_Depends_On_Private (Id, Has_Private_Component (T));
if Present (Generic_Parent_Type (N))
and then
(Nkind
(Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
or else Nkind
(Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
/= N_Formal_Private_Type_Definition)
then
if Is_Tagged_Type (Id) then
if Is_Class_Wide_Type (Id) then
Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
else
Derive_Subprograms (Generic_Parent_Type (N), Id, T);
end if;
elsif Scope (Etype (Id)) /= Standard_Standard then
Derive_Subprograms (Generic_Parent_Type (N), Id);
end if;
end if;
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Conditional_Delay (Id, Full_View (T));
-- The subtypes of components or subcomponents of protected types
-- do not need freeze nodes, which would otherwise appear in the
-- wrong scope (before the freeze node for the protected type). The
-- proper subtypes are those of the subcomponents of the corresponding
-- record.
elsif Ekind (Scope (Id)) /= E_Protected_Type
and then Present (Scope (Scope (Id))) -- error defense!
and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
then
Conditional_Delay (Id, T);
end if;
-- Check that constraint_error is raised for a scalar subtype
-- indication when the lower or upper bound of a non-null range
-- lies outside the range of the type mark.
if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
if Is_Scalar_Type (Etype (Id))
and then Scalar_Range (Id) /=
Scalar_Range (Etype (Subtype_Mark
(Subtype_Indication (N))))
then
Apply_Range_Check
(Scalar_Range (Id),
Etype (Subtype_Mark (Subtype_Indication (N))));
elsif Is_Array_Type (Etype (Id))
and then Present (First_Index (Id))
then
-- This really should be a subprogram that finds the indications
-- to check???
if ((Nkind (First_Index (Id)) = N_Identifier
and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
or else Nkind (First_Index (Id)) = N_Subtype_Indication)
and then
Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
then
declare
Target_Typ : Entity_Id :=
Etype
(First_Index
(Etype (Subtype_Mark (Subtype_Indication (N)))));
begin
R_Checks :=
Range_Check
(Scalar_Range (Etype (First_Index (Id))),
Target_Typ,
Etype (First_Index (Id)),
Defining_Identifier (N));
Insert_Range_Checks
(R_Checks,
N,
Target_Typ,
Sloc (Defining_Identifier (N)));
end;
end if;
end if;
end if;
Check_Eliminated (Id);
end Analyze_Subtype_Declaration;
--------------------------------
-- Analyze_Subtype_Indication --
--------------------------------
procedure Analyze_Subtype_Indication (N : Node_Id) is
T : constant Entity_Id := Subtype_Mark (N);
R : constant Node_Id := Range_Expression (Constraint (N));
begin
Analyze (T);
if R /= Error then
Analyze (R);
Set_Etype (N, Etype (R));
else
Set_Error_Posted (R);
Set_Error_Posted (T);
end if;
end Analyze_Subtype_Indication;
------------------------------
-- Analyze_Type_Declaration --
------------------------------
procedure Analyze_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;
begin
Prev := Find_Type_Name (N);
if Ekind (Prev) = E_Incomplete_Type then
T := Full_View (Prev);
else
T := Prev;
end if;
Set_Is_Pure (T, Is_Pure (Current_Scope));
-- We set the flag Is_First_Subtype here. It is needed to set the
-- corresponding flag for the Implicit class-wide-type created
-- during tagged types processing.
Set_Is_First_Subtype (T, True);
-- Only composite types other than array types are allowed to have
-- discriminants.
case Nkind (Def) is
-- For derived types, the rule will be checked once we've figured
-- out the parent type.
when N_Derived_Type_Definition =>
null;
-- For record types, discriminants are allowed.
when N_Record_Definition =>
null;
when others =>
if Present (Discriminant_Specifications (N)) then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier
(First (Discriminant_Specifications (N))));
end if;
end case;
-- Elaborate the type definition according to kind, and generate
-- susbsidiary (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_Types (Current_Scope)
or else Is_Remote_Call_Interface (Current_Scope)
then
Validate_Remote_Access_To_Subprogram_Type (N);
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, Read and Write attribute must be added.
if (Is_Remote_Call_Interface (Current_Scope)
or else Is_Remote_Types (Current_Scope))
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);
when others =>
raise Program_Error;
end case;
end if;
if Etype (T) = Any_Type then
return;
end if;
-- Some common processing for all types
Set_Depends_On_Private (T, Has_Private_Component (T));
-- 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 is different 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.
if B /= T then
Ensure_Freeze_Node (B);
Set_First_Subtype_Link (Freeze_Node (B), T);
end if;
if not From_With_Type (T) then
Set_Has_Delayed_Freeze (T);
end if;
end;
-- Case of 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.
Generate_Reference (T, T, 'c');
-- If in main unit, set as referenced, so we do not complain about
-- the full declaration being an unreferenced entity.
if In_Extended_Main_Source_Unit (Def_Id) then
Set_Referenced (Def_Id);
end if;
-- 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');
-- If in main unit, set as referenced, so we do not complain about
-- the full declaration being an unreferenced entity.
if In_Extended_Main_Source_Unit (Def_Id) then
Set_Referenced (Def_Id);
end if;
-- 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;
Check_Eliminated (Def_Id);
end Analyze_Type_Declaration;
--------------------------
-- Analyze_Variant_Part --
--------------------------
procedure Analyze_Variant_Part (N : Node_Id) is
procedure Non_Static_Choice_Error (Choice : Node_Id);
-- Error routine invoked by the generic instantiation below when
-- the variant part has a non static choice.
procedure Process_Declarations (Variant : Node_Id);
-- Analyzes all the declarations associated with a Variant.
-- Needed by the generic instantiation below.
package Variant_Choices_Processing is new
Generic_Choices_Processing
(Get_Alternatives => Variants,
Get_Choices => Discrete_Choices,
Process_Empty_Choice => No_OP,
Process_Non_Static_Choice => Non_Static_Choice_Error,
Process_Associated_Node => Process_Declarations);
use Variant_Choices_Processing;
-- Instantiation of the generic choice processing package.
-----------------------------
-- Non_Static_Choice_Error --
-----------------------------
procedure Non_Static_Choice_Error (Choice : Node_Id) is
begin
Error_Msg_N ("choice given in variant part is not static", Choice);
end Non_Static_Choice_Error;
--------------------------
-- Process_Declarations --
--------------------------
procedure Process_Declarations (Variant : Node_Id) is
begin
if not Null_Present (Component_List (Variant)) then
Analyze_Declarations (Component_Items (Component_List (Variant)));
if Present (Variant_Part (Component_List (Variant))) then
Analyze (Variant_Part (Component_List (Variant)));
end if;
end if;
end Process_Declarations;
-- Variables local to Analyze_Case_Statement.
Others_Choice : Node_Id;
Discr_Name : Node_Id;
Discr_Type : Entity_Id;
Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
Last_Choice : Nat;
Dont_Care : Boolean;
Others_Present : Boolean := False;
-- Start of processing for Analyze_Variant_Part
begin
Discr_Name := Name (N);
Analyze (Discr_Name);
if Ekind (Entity (Discr_Name)) /= E_Discriminant then
Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
end if;
Discr_Type := Etype (Entity (Discr_Name));
if not Is_Discrete_Type (Discr_Type) then
Error_Msg_N
("discriminant in a variant part must be of a discrete type",
Name (N));
return;
end if;
-- Call the instantiated Analyze_Choices which does the rest of the work
Analyze_Choices
(N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
if Others_Present then
-- Fill in Others_Discrete_Choices field of the OTHERS choice
Others_Choice := First (Discrete_Choices (Last (Variants (N))));
Expand_Others_Choice
(Case_Table (1 .. Last_Choice), Others_Choice, Discr_Type);
end if;
end Analyze_Variant_Part;
----------------------------
-- Array_Type_Declaration --
----------------------------
procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
Component_Def : constant Node_Id := Subtype_Indication (Def);
Element_Type : Entity_Id;
Implicit_Base : Entity_Id;
Index : Node_Id;
Related_Id : Entity_Id := Empty;
Nb_Index : Nat;
P : constant Node_Id := Parent (Def);
Priv : Entity_Id;
begin
if Nkind (Def) = N_Constrained_Array_Definition then
Index := First (Discrete_Subtype_Definitions (Def));
-- Find proper names for the implicit types which may be public.
-- in case of anonymous arrays we use the name of the first object
-- of that type as prefix.
if No (T) then
Related_Id := Defining_Identifier (P);
else
Related_Id := T;
end if;
else
Index := First (Subtype_Marks (Def));
end if;
Nb_Index := 1;
while Present (Index) loop
Analyze (Index);
Make_Index (Index, P, Related_Id, Nb_Index);
Next_Index (Index);
Nb_Index := Nb_Index + 1;
end loop;
Element_Type := Process_Subtype (Component_Def, P, Related_Id, 'C');
-- Constrained array case
if No (T) then
T := Create_Itype (E_Void, P, Related_Id, 'T');
end if;
if Nkind (Def) = N_Constrained_Array_Definition then
-- Establish Implicit_Base as unconstrained base type
Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
Init_Size_Align (Implicit_Base);
Set_Etype (Implicit_Base, Implicit_Base);
Set_Scope (Implicit_Base, Current_Scope);
Set_Has_Delayed_Freeze (Implicit_Base);
-- The constrained array type is a subtype of the unconstrained one
Set_Ekind (T, E_Array_Subtype);
Init_Size_Align (T);
Set_Etype (T, Implicit_Base);
Set_Scope (T, Current_Scope);
Set_Is_Constrained (T, True);
Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
Set_Has_Delayed_Freeze (T);
-- Complete setup of implicit base type
Set_First_Index (Implicit_Base, First_Index (T));
Set_Component_Type (Implicit_Base, Element_Type);
Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
Set_Component_Size (Implicit_Base, Uint_0);
Set_Has_Controlled_Component (Implicit_Base,
Has_Controlled_Component (Element_Type)
or else Is_Controlled (Element_Type));
Set_Finalize_Storage_Only (Implicit_Base,
Finalize_Storage_Only (Element_Type));
-- Unconstrained array case
else
Set_Ekind (T, E_Array_Type);
Init_Size_Align (T);
Set_Etype (T, T);
Set_Scope (T, Current_Scope);
Set_Component_Size (T, Uint_0);
Set_Is_Constrained (T, False);
Set_First_Index (T, First (Subtype_Marks (Def)));
Set_Has_Delayed_Freeze (T, True);
Set_Has_Task (T, Has_Task (Element_Type));
Set_Has_Controlled_Component (T,
Has_Controlled_Component (Element_Type)
or else Is_Controlled (Element_Type));
Set_Finalize_Storage_Only (T,
Finalize_Storage_Only (Element_Type));
end if;
Set_Component_Type (T, Element_Type);
if Aliased_Present (Def) then
Set_Has_Aliased_Components (Etype (T));
end if;
Priv := Private_Component (Element_Type);
if Present (Priv) then
-- Check for circular definitions.
if Priv = Any_Type then
Set_Component_Type (T, Any_Type);
Set_Component_Type (Etype (T), Any_Type);
-- There is a gap in the visiblity of operations on the composite
-- type only if the component type is defined in a different scope.
elsif Scope (Priv) = Current_Scope then
null;
elsif Is_Limited_Type (Priv) then
Set_Is_Limited_Composite (Etype (T));
Set_Is_Limited_Composite (T);
else
Set_Is_Private_Composite (Etype (T));
Set_Is_Private_Composite (T);
end if;
end if;
-- Create a concatenation operator for the new type. Internal
-- array types created for packed entities do not need such, they
-- are compatible with the user-defined type.
if Number_Dimensions (T) = 1
and then not Is_Packed_Array_Type (T)
then
New_Binary_Operator (Name_Op_Concat, T);
end if;
-- In the case of an unconstrained array the parser has already
-- verified that all the indices are unconstrained but we still
-- need to make sure that the element type is constrained.
if Is_Indefinite_Subtype (Element_Type) then
Error_Msg_N
("unconstrained element type in array declaration ",
Component_Def);
elsif Is_Abstract (Element_Type) then
Error_Msg_N ("The type of a component cannot be abstract ",
Component_Def);
end if;
end Array_Type_Declaration;
-------------------------------
-- Build_Derived_Access_Type --
-------------------------------
procedure Build_Derived_Access_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
S : constant Node_Id := Subtype_Indication (Type_Definition (N));
Desig_Type : Entity_Id;
Discr : Entity_Id;
Discr_Con_Elist : Elist_Id;
Discr_Con_El : Elmt_Id;
Subt : Entity_Id;
begin
-- Set the designated type so it is available in case this is
-- an access to a self-referential type, e.g. a standard list
-- type with a next pointer. Will be reset after subtype is built.
Set_Directly_Designated_Type (Derived_Type,
Designated_Type (Parent_Type));
Subt := Process_Subtype (S, N);
if Nkind (S) /= N_Subtype_Indication
and then Subt /= Base_Type (Subt)
then
Set_Ekind (Derived_Type, E_Access_Subtype);
end if;
if Ekind (Derived_Type) = E_Access_Subtype then
declare
Pbase : constant Entity_Id := Base_Type (Parent_Type);
Ibase : constant Entity_Id :=
Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
Svg_Chars : constant Name_Id := Chars (Ibase);
Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
begin
Copy_Node (Pbase, Ibase);
Set_Chars (Ibase, Svg_Chars);
Set_Next_Entity (Ibase, Svg_Next_E);
Set_Sloc (Ibase, Sloc (Derived_Type));
Set_Scope (Ibase, Scope (Derived_Type));
Set_Freeze_Node (Ibase, Empty);
Set_Is_Frozen (Ibase, False);
Set_Etype (Ibase, Pbase);
Set_Etype (Derived_Type, Ibase);
end;
end if;
Set_Directly_Designated_Type
(Derived_Type, Designated_Type (Subt));
Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
Set_Size_Info (Derived_Type, Parent_Type);
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
Set_Depends_On_Private (Derived_Type,
Has_Private_Component (Derived_Type));
Conditional_Delay (Derived_Type, Subt);
-- Note: we do not copy the Storage_Size_Variable, since
-- we always go to the root type for this information.
-- Apply range checks to discriminants for derived record case
-- ??? THIS CODE SHOULD NOT BE HERE REALLY.
Desig_Type := Designated_Type (Derived_Type);
if Is_Composite_Type (Desig_Type)
and then (not Is_Array_Type (Desig_Type))
and then Has_Discriminants (Desig_Type)
and then Base_Type (Desig_Type) /= Desig_Type
then
Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
Discr_Con_El := First_Elmt (Discr_Con_Elist);
Discr := First_Discriminant (Base_Type (Desig_Type));
while Present (Discr_Con_El) loop
Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
Next_Elmt (Discr_Con_El);
Next_Discriminant (Discr);
end loop;
end if;
end Build_Derived_Access_Type;
------------------------------
-- Build_Derived_Array_Type --
------------------------------
procedure Build_Derived_Array_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : Entity_Id;
New_Indic : Node_Id;
procedure Make_Implicit_Base;
-- If the parent subtype is constrained, the derived type is a
-- subtype of an implicit base type derived from the parent base.
------------------------
-- Make_Implicit_Base --
------------------------
procedure Make_Implicit_Base is
begin
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Set_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Etype (Implicit_Base, Parent_Base);
Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
Set_Has_Delayed_Freeze (Implicit_Base, True);
end Make_Implicit_Base;
-- Start of processing for Build_Derived_Array_Type
begin
if not Is_Constrained (Parent_Type) then
if Nkind (Indic) /= N_Subtype_Indication then
Set_Ekind (Derived_Type, E_Array_Type);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
Set_Has_Delayed_Freeze (Derived_Type, True);
else
Make_Implicit_Base;
Set_Etype (Derived_Type, Implicit_Base);
New_Indic :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
Constraint => Constraint (Indic)));
Rewrite (N, New_Indic);
Analyze (N);
end if;
else
if Nkind (Indic) /= N_Subtype_Indication then
Make_Implicit_Base;
Set_Ekind (Derived_Type, Ekind (Parent_Type));
Set_Etype (Derived_Type, Implicit_Base);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
else
Error_Msg_N ("illegal constraint on constrained type", Indic);
end if;
end if;
-- If the parent type is not a derived type itself, and is
-- declared in a closed scope (e.g., a subprogram), then we
-- need to explicitly introduce the new type's concatenation
-- operator since Derive_Subprograms will not inherit the
-- parent's operator.
if Number_Dimensions (Parent_Type) = 1
and then not Is_Limited_Type (Parent_Type)
and then not Is_Derived_Type (Parent_Type)
and then not Is_Package (Scope (Base_Type (Parent_Type)))
then
New_Binary_Operator (Name_Op_Concat, Derived_Type);
end if;
end Build_Derived_Array_Type;
-----------------------------------
-- Build_Derived_Concurrent_Type --
-----------------------------------
procedure Build_Derived_Concurrent_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
D_Constraint : Node_Id;
Disc_Spec : Node_Id;
Old_Disc : Entity_Id;
New_Disc : Entity_Id;
Constraint_Present : constant Boolean :=
Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication;
begin
Set_Girder_Constraint (Derived_Type, No_Elist);
if Is_Task_Type (Parent_Type) then
Set_Storage_Size_Variable (Derived_Type,
Storage_Size_Variable (Parent_Type));
end if;
if Present (Discriminant_Specifications (N)) then
New_Scope (Derived_Type);
Check_Or_Process_Discriminants (N, Derived_Type);
End_Scope;
elsif Constraint_Present then
-- Build constrained subtype and derive from it
declare
Loc : constant Source_Ptr := Sloc (N);
Anon : Entity_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Derived_Type), 'T'));
Decl : Node_Id;
begin
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Anon,
Subtype_Indication =>
New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
Insert_Before (N, Decl);
Rewrite (Subtype_Indication (Type_Definition (N)),
New_Occurrence_Of (Anon, Loc));
Analyze (Decl);
Set_Analyzed (Derived_Type, False);
Analyze (N);
return;
end;
end if;
-- All attributes are inherited from parent. In particular,
-- entries and the corresponding record type are the same.
-- Discriminants may be renamed, and must be treated separately.
Set_Has_Discriminants
(Derived_Type, Has_Discriminants (Parent_Type));
Set_Corresponding_Record_Type
(Derived_Type, Corresponding_Record_Type (Parent_Type));
if Constraint_Present then
if not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", N);
elsif Present (Discriminant_Specifications (N)) then
-- Verify that new discriminants are used to constrain
-- the old ones.
Old_Disc := First_Discriminant (Parent_Type);
New_Disc := First_Discriminant (Derived_Type);
Disc_Spec := First (Discriminant_Specifications (N));
D_Constraint :=
First
(Constraints
(Constraint (Subtype_Indication (Type_Definition (N)))));
while Present (Old_Disc) and then Present (Disc_Spec) loop
if Nkind (Discriminant_Type (Disc_Spec)) /=
N_Access_Definition
then
Analyze (Discriminant_Type (Disc_Spec));
if not Subtypes_Statically_Compatible (
Etype (Discriminant_Type (Disc_Spec)),
Etype (Old_Disc))
then
Error_Msg_N
("not statically compatible with parent discriminant",
Discriminant_Type (Disc_Spec));
end if;
end if;
if Nkind (D_Constraint) = N_Identifier
and then Chars (D_Constraint) /=
Chars (Defining_Identifier (Disc_Spec))
then
Error_Msg_N ("new discriminants must constrain old ones",
D_Constraint);
else
Set_Corresponding_Discriminant (New_Disc, Old_Disc);
end if;
Next_Discriminant (Old_Disc);
Next_Discriminant (New_Disc);
Next (Disc_Spec);
end loop;
if Present (Old_Disc) or else Present (Disc_Spec) then
Error_Msg_N ("discriminant mismatch in derivation", N);
end if;
end if;
elsif Present (Discriminant_Specifications (N)) then
Error_Msg_N
("missing discriminant constraint in untagged derivation",
N);
end if;
if Present (Discriminant_Specifications (N)) then
Old_Disc := First_Discriminant (Parent_Type);
while Present (Old_Disc) loop
if No (Next_Entity (Old_Disc))
or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
then
Set_Next_Entity (Last_Entity (Derived_Type),
Next_Entity (Old_Disc));
exit;
end if;
Next_Discriminant (Old_Disc);
end loop;
else
Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
if Has_Discriminants (Parent_Type) then
Set_Discriminant_Constraint (
Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
Set_Has_Completion (Derived_Type);
end Build_Derived_Concurrent_Type;
------------------------------------
-- Build_Derived_Enumeration_Type --
------------------------------------
procedure Build_Derived_Enumeration_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Implicit_Base : Entity_Id;
Literal : Entity_Id;
New_Lit : Entity_Id;
Literals_List : List_Id;
Type_Decl : Node_Id;
Hi, Lo : Node_Id;
Rang_Expr : Node_Id;
begin
-- Since types Standard.Character and Standard.Wide_Character do
-- not have explicit literals lists we need to process types derived
-- from them specially. This is handled by Derived_Standard_Character.
-- If the parent type is a generic type, there are no literals either,
-- and we construct the same skeletal representation as for the generic
-- parent type.
if Root_Type (Parent_Type) = Standard_Character
or else Root_Type (Parent_Type) = Standard_Wide_Character
then
Derived_Standard_Character (N, Parent_Type, Derived_Type);
elsif Is_Generic_Type (Root_Type (Parent_Type)) then
declare
Lo : Node_Id;
Hi : Node_Id;
begin
Lo :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Derived_Type, Loc));
Set_Etype (Lo, Derived_Type);
Hi :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Derived_Type, Loc));
Set_Etype (Hi, Derived_Type);
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
end;
else
-- If a constraint is present, analyze the bounds to catch
-- premature usage of the derived literals.
if Nkind (Indic) = N_Subtype_Indication
and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
then
Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
Analyze (High_Bound (Range_Expression (Constraint (Indic))));
end if;
-- Introduce an implicit base type for the derived type even
-- if there is no constraint attached to it, since this seems
-- closer to the Ada semantics. Build a full type declaration
-- tree for the derived type using the implicit base type as
-- the defining identifier. The build a subtype declaration
-- tree which applies the constraint (if any) have it replace
-- the derived type declaration.
Literal := First_Literal (Parent_Type);
Literals_List := New_List;
while Present (Literal)
and then Ekind (Literal) = E_Enumeration_Literal
loop
-- Literals of the derived type have the same representation as
-- those of the parent type, but this representation can be
-- overridden by an explicit representation clause. Indicate
-- that there is no explicit representation given yet. These
-- derived literals are implicit operations of the new type,
-- and can be overriden by explicit ones.
if Nkind (Literal) = N_Defining_Character_Literal then
New_Lit :=
Make_Defining_Character_Literal (Loc, Chars (Literal));
else
New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
end if;
Set_Ekind (New_Lit, E_Enumeration_Literal);
Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
Set_Enumeration_Rep_Expr (New_Lit, Empty);
Set_Alias (New_Lit, Literal);
Set_Is_Known_Valid (New_Lit, True);
Append (New_Lit, Literals_List);
Next_Literal (Literal);
end loop;
Implicit_Base :=
Make_Defining_Identifier (Sloc (Derived_Type),
New_External_Name (Chars (Derived_Type), 'B'));
-- Indicate the proper nature of the derived type. This must
-- be done before analysis of the literals, to recognize cases
-- when a literal may be hidden by a previous explicit function
-- definition (cf. c83031a).
Set_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Type_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Implicit_Base,
Discriminant_Specifications => No_List,
Type_Definition =>
Make_Enumeration_Type_Definition (Loc, Literals_List));
Mark_Rewrite_Insertion (Type_Decl);
Insert_Before (N, Type_Decl);
Analyze (Type_Decl);
-- After the implicit base is analyzed its Etype needs to be
-- changed to reflect the fact that it is derived from the
-- parent type which was ignored during analysis. We also set
-- the size at this point.
Set_Etype (Implicit_Base, Parent_Type);
Set_Size_Info (Implicit_Base, Parent_Type);
Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
Set_Has_Non_Standard_Rep
(Implicit_Base, Has_Non_Standard_Rep
(Parent_Type));
Set_Has_Delayed_Freeze (Implicit_Base);
-- Process the subtype indication including a validation check
-- on the constraint, if any. If a constraint is given, its bounds
-- must be implicitly converted to the new type.
if Nkind (Indic) = N_Subtype_Indication then
declare
R : constant Node_Id :=
Range_Expression (Constraint (Indic));
begin
if Nkind (R) = N_Range then
Hi := Build_Scalar_Bound
(High_Bound (R), Parent_Type, Implicit_Base, Loc);
Lo := Build_Scalar_Bound
(Low_Bound (R), Parent_Type, Implicit_Base, Loc);
else
-- Constraint is a Range attribute. Replace with the
-- explicit mention of the bounds of the prefix, which
-- must be a subtype.
Analyze (Prefix (R));
Hi :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
Lo :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
end if;
end;
else
Hi :=
Build_Scalar_Bound
(Type_High_Bound (Parent_Type),
Parent_Type, Implicit_Base, Loc);
Lo :=
Build_Scalar_Bound
(Type_Low_Bound (Parent_Type),
Parent_Type, Implicit_Base, Loc);
end if;
Rang_Expr :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
-- If we constructed a default range for the case where no range
-- was given, then the expressions in the range must not freeze
-- since they do not correspond to expressions in the source.
if Nkind (Indic) /= N_Subtype_Indication then
Set_Must_Not_Freeze (Lo);
Set_Must_Not_Freeze (Hi);
Set_Must_Not_Freeze (Rang_Expr);
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
Constraint =>
Make_Range_Constraint (Loc,
Range_Expression => Rang_Expr))));
Analyze (N);
-- If pragma Discard_Names applies on the first subtype
-- of the parent type, then it must be applied on this
-- subtype as well.
if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
Set_Discard_Names (Derived_Type);
end if;
-- Apply a range check. Since this range expression doesn't
-- have an Etype, we have to specifically pass the Source_Typ
-- parameter. Is this right???
if Nkind (Indic) = N_Subtype_Indication then
Apply_Range_Check (Range_Expression (Constraint (Indic)),
Parent_Type,
Source_Typ => Entity (Subtype_Mark (Indic)));
end if;
end if;
end Build_Derived_Enumeration_Type;
--------------------------------
-- Build_Derived_Numeric_Type --
--------------------------------
procedure Build_Derived_Numeric_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
No_Constraint : constant Boolean := Nkind (Indic) /=
N_Subtype_Indication;
Implicit_Base : Entity_Id;
Lo : Node_Id;
Hi : Node_Id;
T : Entity_Id;
begin
-- Process the subtype indication including a validation check on
-- the constraint if any.
T := Process_Subtype (Indic, N);
-- Introduce an implicit base type for the derived type even if
-- there is no constraint attached to it, since this seems closer
-- to the Ada semantics.
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Set_Etype (Implicit_Base, Parent_Base);
Set_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Size_Info (Implicit_Base, Parent_Base);
Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
Set_Parent (Implicit_Base, Parent (Derived_Type));
if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
end if;
Set_Has_Delayed_Freeze (Implicit_Base);
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
if Has_Infinities (Parent_Base) then
Set_Includes_Infinities (Scalar_Range (Implicit_Base));
end if;
-- The Derived_Type, which is the entity of the declaration, is
-- a subtype of the implicit base. Its Ekind is a subtype, even
-- in the absence of an explicit constraint.
Set_Etype (Derived_Type, Implicit_Base);
-- If we did not have a constraint, then the Ekind is set from the
-- parent type (otherwise Process_Subtype has set the bounds)
if No_Constraint then
Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
end if;
-- If we did not have a range constraint, then set the range
-- from the parent type. Otherwise, the call to Process_Subtype
-- has set the bounds.
if No_Constraint
or else not Has_Range_Constraint (Indic)
then
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
if Has_Infinities (Parent_Type) then
Set_Includes_Infinities (Scalar_Range (Derived_Type));
end if;
end if;
-- Set remaining type-specific fields, depending on numeric type
if Is_Modular_Integer_Type (Parent_Type) then
Set_Modulus (Implicit_Base, Modulus (Parent_Base));
Set_Non_Binary_Modulus
(Implicit_Base, Non_Binary_Modulus (Parent_Base));
elsif Is_Floating_Point_Type (Parent_Type) then
-- Digits of base type is always copied from the digits value of
-- the parent base type, but the digits of the derived type will
-- already have been set if there was a constraint present.
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
end if;
elsif Is_Fixed_Point_Type (Parent_Type) then
-- Small of base type and derived type are always copied from
-- the parent base type, since smalls never change. The delta
-- of the base type is also copied from the parent base type.
-- However the delta of the derived type will have been set
-- already if a constraint was present.
Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
if No_Constraint then
Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
end if;
-- The scale and machine radix in the decimal case are always
-- copied from the parent base type.
if Is_Decimal_Fixed_Point_Type (Parent_Type) then
Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
Set_Machine_Radix_10
(Derived_Type, Machine_Radix_10 (Parent_Base));
Set_Machine_Radix_10
(Implicit_Base, Machine_Radix_10 (Parent_Base));
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
else
-- the analysis of the subtype_indication sets the
-- digits value of the derived type.
null;
end if;
end if;
end if;
-- The type of the bounds is that of the parent type, and they
-- must be converted to the derived type.
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
-- The implicit_base should be frozen when the derived type is frozen,
-- but note that it is used in the conversions of the bounds. For
-- fixed types we delay the determination of the bounds until the proper
-- freezing point. For other numeric types this is rejected by GCC, for
-- reasons that are currently unclear (???), so we choose to freeze the
-- implicit base now. In the case of integers and floating point types
-- this is harmless because subsequent representation clauses cannot
-- affect anything, but it is still baffling that we cannot use the
-- same mechanism for all derived numeric types.
if Is_Fixed_Point_Type (Parent_Type) then
Conditional_Delay (Implicit_Base, Parent_Type);
else
Freeze_Before (N, Implicit_Base);
end if;
end Build_Derived_Numeric_Type;
--------------------------------
-- Build_Derived_Private_Type --
--------------------------------
procedure Build_Derived_Private_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Der_Base : Entity_Id;
Discr : Entity_Id;
Full_Decl : Node_Id := Empty;
Full_Der : Entity_Id;
Full_P : Entity_Id;
Last_Discr : Entity_Id;
Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
Swapped : Boolean := False;
procedure Copy_And_Build;
-- Copy derived type declaration, replace parent with its full view,
-- and analyze new declaration.
procedure Copy_And_Build is
Full_N : Node_Id;
begin
if Ekind (Parent_Type) in Record_Kind
or else (Ekind (Parent_Type) in Enumeration_Kind
and then Root_Type (Parent_Type) /= Standard_Character
and then Root_Type (Parent_Type) /= Standard_Wide_Character
and then not Is_Generic_Type (Root_Type (Parent_Type)))
then
Full_N := New_Copy_Tree (N);
Insert_After (N, Full_N);
Build_Derived_Type (
Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
else
Build_Derived_Type (
N, Parent_Type, Full_Der, True, Derive_Subps => False);
end if;
end Copy_And_Build;
-- Start of processing for Build_Derived_Private_Type
begin
if Is_Tagged_Type (Parent_Type) then
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
return;
elsif Has_Discriminants (Parent_Type) then
if Present (Full_View (Parent_Type)) then
if not Is_Completion then
-- Copy declaration for subsequent analysis.
Full_Decl := New_Copy_Tree (N);
Full_Der := New_Copy (Derived_Type);
Insert_After (N, Full_Decl);
else
-- If this is a completion, the full view being built is
-- itself private. We build a subtype of the parent with
-- the same constraints as this full view, to convey to the
-- back end the constrained components and the size of this
-- subtype. If the parent is constrained, its full view can
-- serve as the underlying full view of the derived type.
if No (Discriminant_Specifications (N)) then
if Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication
then
Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
elsif Is_Constrained (Full_View (Parent_Type)) then
Set_Underlying_Full_View (Derived_Type,
Full_View (Parent_Type));
end if;
else
-- If there are new discriminants, the parent subtype is
-- constrained by them, but it is not clear how to build
-- the underlying_full_view in this case ???
null;
end if;
end if;
end if;
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
if Present (Full_View (Parent_Type))
and then not Is_Completion
then
if not In_Open_Scopes (Par_Scope)
or else not In_Same_Source_Unit (N, Parent_Type)
then
-- Swap partial and full views temporarily
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Swapped := True;
end if;
-- Subprograms have been derived on the private view,
-- the completion does not derive them anew.
Build_Derived_Record_Type
(Full_Decl, Parent_Type, Full_Der, False);
if Swapped then
Uninstall_Declarations (Par_Scope);
if In_Open_Scopes (Par_Scope) then
Install_Visible_Declarations (Par_Scope);
end if;
end if;
Der_Base := Base_Type (Derived_Type);
Set_Full_View (Derived_Type, Full_Der);
Set_Full_View (Der_Base, Base_Type (Full_Der));
-- Copy the discriminant list from full view to
-- the partial views (base type and its subtype).
-- Gigi requires that the partial and full views
-- have the same discriminants.
-- ??? Note that since the partial view is pointing
-- to discriminants in the full view, their scope
-- will be that of the full view. This might
-- cause some front end problems and need
-- adustment?
Discr := First_Discriminant (Base_Type (Full_Der));
Set_First_Entity (Der_Base, Discr);
loop
Last_Discr := Discr;
Next_Discriminant (Discr);
exit when No (Discr);
end loop;
Set_Last_Entity (Der_Base, Last_Discr);
Set_First_Entity (Derived_Type, First_Entity (Der_Base));
Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
else
-- If this is a completion, the derived type stays private
-- and there is no need to create a further full view, except
-- in the unusual case when the derivation is nested within a
-- child unit, see below.
null;
end if;
elsif Present (Full_View (Parent_Type))
and then Has_Discriminants (Full_View (Parent_Type))
then
if Has_Unknown_Discriminants (Parent_Type)
and then Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication
then
Error_Msg_N
("cannot constrain type with unknown discriminants",
Subtype_Indication (Type_Definition (N)));
return;
end if;
-- Inherit the discriminants of the full view, but
-- keep the proper parent type.
-- ??? this looks wrong, we are replacing (and thus,
-- erasing) the partial view!
-- In any case, the primitive operations are inherited from
-- the parent type, not from the internal full view.
Build_Derived_Record_Type
(N, Full_View (Parent_Type), Derived_Type,
Derive_Subps => False);
Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
else
-- Untagged type, No discriminants on either view.
if Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication
then
Error_Msg_N
("illegal constraint on type without discriminants", N);
end if;
if Present (Discriminant_Specifications (N))
and then Present (Full_View (Parent_Type))
and then not Is_Tagged_Type (Full_View (Parent_Type))
then
Error_Msg_N
("cannot add discriminants to untagged type", N);
end if;
Set_Girder_Constraint (Derived_Type, No_Elist);
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
Set_Has_Controlled_Component (Derived_Type,
Has_Controlled_Component (Parent_Type));
-- Direct controlled types do not inherit the Finalize_Storage_Only
-- flag.
if not Is_Controlled (Parent_Type) then
Set_Finalize_Storage_Only (Derived_Type,
Finalize_Storage_Only (Parent_Type));
end if;
-- Construct the implicit full view by deriving from full
-- view of the parent type. In order to get proper visiblity,
-- we install the parent scope and its declarations.
-- ??? if the parent is untagged private and its
-- completion is tagged, this mechanism will not
-- work because we cannot derive from the tagged
-- full view unless we have an extension
if Present (Full_View (Parent_Type))
and then not Is_Tagged_Type (Full_View (Parent_Type))
and then not Is_Completion
then
Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, Parent (Derived_Type));
Set_Full_View (Derived_Type, Full_Der);
if not In_Open_Scopes (Par_Scope) then
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Copy_And_Build;
Uninstall_Declarations (Par_Scope);
-- If parent scope is open and in another unit, and
-- parent has a completion, then the derivation is taking
-- place in the visible part of a child unit. In that
-- case retrieve the full view of the parent momentarily.
elsif not In_Same_Source_Unit (N, Parent_Type) then
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
-- Otherwise it is a local derivation.
else
Copy_And_Build;
end if;
Set_Scope (Full_Der, Current_Scope);
Set_Is_First_Subtype (Full_Der,
Is_First_Subtype (Derived_Type));
Set_Has_Size_Clause (Full_Der, False);
Set_Has_Alignment_Clause (Full_Der, False);
Set_Next_Entity (Full_Der, Empty);
Set_Has_Delayed_Freeze (Full_Der);
Set_Is_Frozen (Full_Der, False);
Set_Freeze_Node (Full_Der, Empty);
Set_Depends_On_Private (Full_Der,
Has_Private_Component (Full_Der));
Set_Public_Status (Full_Der);
end if;
end if;
Set_Has_Unknown_Discriminants (Derived_Type,
Has_Unknown_Discriminants (Parent_Type));
if Is_Private_Type (Derived_Type) then
Set_Private_Dependents (Derived_Type, New_Elmt_List);
end if;
if Is_Private_Type (Parent_Type)
and then Base_Type (Parent_Type) = Parent_Type
and then In_Open_Scopes (Scope (Parent_Type))
then
Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
if Is_Child_Unit (Scope (Current_Scope))
and then Is_Completion
and then In_Private_Part (Current_Scope)
and then Scope (Parent_Type) /= Current_Scope
then
-- This is the unusual case where a type completed by a private
-- derivation occurs within a package nested in a child unit,
-- and the parent is declared in an ancestor. In this case, the
-- full view of the parent type will become visible in the body
-- of the enclosing child, and only then will the current type
-- be possibly non-private. We build a underlying full view that
-- will be installed when the enclosing child body is compiled.
declare
IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
begin
Full_Der :=
Make_Defining_Identifier (Sloc (Derived_Type),
Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Itype (IR, Full_Der);
Insert_After (N, IR);
-- The full view will be used to swap entities on entry/exit
-- to the body, and must appear in the entity list for the
-- package.
Append_Entity (Full_Der, Scope (Derived_Type));
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, Parent (Derived_Type));
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
Set_Underlying_Full_View (Derived_Type, Full_Der);
end;
end if;
end if;
end Build_Derived_Private_Type;
-------------------------------
-- Build_Derived_Record_Type --
-------------------------------
-- 1. INTRODUCTION.
-- Ideally we would like to use the same model of type derivation for
-- tagged and untagged record types. Unfortunately this is not quite
-- possible because the semantics of representation clauses is different
-- for tagged and untagged records under inheritance. Consider the
-- following:
-- type R (...) is [tagged] record ... end record;
-- type T (...) is new R (...) [with ...];
-- The representation clauses of T can specify a completely different
-- record layout from R's. Hence a same component can be placed in two very
-- different positions in objects of type T and R. If R and T are tagged
-- types, representation clauses for T can only specify the layout of non
-- inherited components, thus components that are common in R and T have
-- the same position in objects of type R or T.
-- This has two implications. The first is that the entire tree for R's
-- declaration needs to be copied for T in the untagged case, so that
-- T can be viewd as a record type of its own with its own derivation
-- clauses. The second implication is the way we handle discriminants.
-- Specifically, in the untagged case we need a way to communicate to Gigi
-- what are the real discriminants in the record, while for the semantics
-- we need to consider those introduced by the user to rename the
-- discriminants in the parent type. This is handled by introducing the
-- notion of girder discriminants. See below for more.
-- Fortunately the way regular components are inherited can be handled in
-- the same way in tagged and untagged types.
-- To complicate things a bit more the private view of a private extension
-- cannot be handled in the same way as the full view (for one thing the
-- semantic rules are somewhat different). We will explain what differs
-- below.
-- 2. DISCRIMINANTS UNDER INHERITANCE.
-- The semantic rules governing the discriminants of derived types are
-- quite subtle.
-- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
-- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
-- If parent type has discriminants, then the discriminants that are
-- declared in the derived type are [3.4 (11)]:
-- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
-- there is one;
-- o Otherwise, each discriminant of the parent type (implicitly
-- declared in the same order with the same specifications). In this
-- case, the discriminants are said to be "inherited", or if unknown in
-- the parent are also unknown in the derived type.
-- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
-- o The parent subtype shall be constrained;
-- o If the parent type is not a tagged type, then each discriminant of
-- the derived type shall be used in the constraint defining a parent
-- subtype [Implementation note: this ensures that the new discriminant
-- can share storage with an existing discriminant.].
-- For the derived type each discriminant of the parent type is either
-- inherited, constrained to equal some new discriminant of the derived
-- type, or constrained to the value of an expression.
-- When inherited or constrained to equal some new discriminant, the
-- parent discriminant and the discriminant of the derived type are said
-- to "correspond".
-- If a discriminant of the parent type is constrained to a specific value
-- in the derived type definition, then the discriminant is said to be
-- "specified" by that derived type definition.
-- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
-- We have spoken about girder discriminants in the point 1 (introduction)
-- above. There are two sort of girder discriminants: implicit and
-- explicit. As long as the derived type inherits the same discriminants as
-- the root record type, girder discriminants are the same as regular
-- discriminants, and are said to be implicit. However, if any discriminant
-- in the root type was renamed in the derived type, then the derived
-- type will contain explicit girder discriminants. Explicit girder
-- discriminants are discriminants in addition to the semantically visible
-- discriminants defined for the derived type. Girder discriminants are
-- used by Gigi to figure out what are the physical discriminants in
-- objects of the derived type (see precise definition in einfo.ads).
-- As an example, consider the following:
-- type R (D1, D2, D3 : Int) is record ... end record;
-- type T1 is new R;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
-- type T3 is new T2;
-- type T4 (Y : Int) is new T3 (Y, 99);
-- The following table summarizes the discriminants and girder
-- discriminants in R and T1 through T4.
-- Type Discrim Girder Discrim Comment
-- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
-- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
-- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
-- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
-- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
-- Field Corresponding_Discriminant (abbreviated CD below) allows to find
-- the corresponding discriminant in the parent type, while
-- Original_Record_Component (abbreviated ORC below), the actual physical
-- component that is renamed. Finally the field Is_Completely_Hidden
-- (abbreaviated ICH below) is set for all explicit girder discriminants
-- (see einfo.ads for more info). For the above example this gives:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R itself no
-- D2 in T1 D2 in R itself no
-- D3 in T1 D3 in R itself no
-- X1 in T2 D3 in T1 D3 in T2 no
-- X2 in T2 D1 in T1 D1 in T2 no
-- D1 in T2 empty itself yes
-- D2 in T2 empty itself yes
-- D3 in T2 empty itself yes
-- X1 in T3 X1 in T2 D3 in T3 no
-- X2 in T3 X2 in T2 D1 in T3 no
-- D1 in T3 empty itself yes
-- D2 in T3 empty itself yes
-- D3 in T3 empty itself yes
-- Y in T4 X1 in T3 D3 in T3 no
-- D1 in T3 empty itself yes
-- D2 in T3 empty itself yes
-- D3 in T3 empty itself yes
-- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
-- Type derivation for tagged types is fairly straightforward. if no
-- discriminants are specified by the derived type, these are inherited
-- from the parent. No explicit girder discriminants are ever necessary.
-- The only manipulation that is done to the tree is that of adding a
-- _parent field with parent type and constrained to the same constraint
-- specified for the parent in the derived type definition. For instance:
-- type R (D1, D2, D3 : Int) is tagged record ... end record;
-- type T1 is new R with null record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
-- are changed into :
-- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
-- _parent : R (D1, D2, D3);
-- end record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
-- _parent : T1 (X2, 88, X1);
-- end record;
-- The discriminants actually present in R, T1 and T2 as well as their CD,
-- ORC and ICH fields are:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R D1 in R no
-- D2 in T1 D2 in R D2 in R no
-- D3 in T1 D3 in R D3 in R no
-- X1 in T2 D3 in T1 D3 in R no
-- X2 in T2 D1 in T1 D1 in R no
-- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
--
-- Regardless of whether we dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
--
-- type T is new R (...) [with ...];
-- or
-- subtype S is R (...);
-- type T is new S [with ...];
-- into
-- type BT is new R [with ...];
-- subtype T is BT (...);
--
-- That is, the base derived type is constrained only if it has no
-- discriminants. The reason for doing this is that GNAT's semantic model
-- assumes that a base type with discriminants is unconstrained.
--
-- Note that, strictly speaking, the above transformation is not always
-- correct. Consider for instance the following exercpt from ACVC b34011a:
--
-- procedure B34011A is
-- type REC (D : integer := 0) is record
-- I : Integer;
-- end record;
-- package P is
-- type T6 is new Rec;
-- function F return T6;
-- end P;
-- use P;
-- package Q6 is
-- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
-- end Q6;
--
-- The definition of Q6.U is illegal. However transforming Q6.U into
-- type BaseU is new T6;
-- subtype U is BaseU (Q6.F.I)
-- turns U into a legal subtype, which is incorrect. To avoid this problem
-- we always analyze the constraint (in this case (Q6.F.I)) before applying
-- the transformation described above.
-- There is another instance where the above transformation is incorrect.
-- Consider:
-- package Pack is
-- type Base (D : Integer) is tagged null record;
-- procedure P (X : Base);
-- type Der is new Base (2) with null record;
-- procedure P (X : Der);
-- end Pack;
-- Then the above transformation turns this into
-- type Der_Base is new Base with null record;
-- -- procedure P (X : Base) is implicitly inherited here
-- -- as procedure P (X : Der_Base).
-- subtype Der is Der_Base (2);
-- procedure P (X : Der);
-- -- The overriding of P (X : Der_Base) is illegal since we
-- -- have a parameter conformance problem.
-- To get around this problem, after having semantically processed Der_Base
-- and the rewritten subtype declaration for Der, we copy Der_Base field
-- Discriminant_Constraint from Der so that when parameter conformance is
-- checked when P is overridden, no sematic errors are flagged.
-- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
-- Regardless of the fact that we dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
-- type R (D1, .., Dn : ...) is [tagged] record ...;
-- type T is new R [with ...];
-- into
-- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
-- The reason for such transformation is that it allows us to implement a
-- very clean form of component inheritance as explained below.
-- Note that this transformation is not achieved by direct tree rewriting
-- and manipulation, but rather by redoing the semantic actions that the
-- above transformation will entail. This is done directly in routine
-- Inherit_Components.
-- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
-- In both tagged and untagged derived types, regular non discriminant
-- components are inherited in the derived type from the parent type. In
-- the absence of discriminants component, inheritance is straightforward
-- as components can simply be copied from the parent.
-- If the parent has discriminants, inheriting components constrained with
-- these discriminants requires caution. Consider the following example:
-- type R (D1, D2 : Positive) is [tagged] record
-- S : String (D1 .. D2);
-- end record;
-- type T1 is new R [with null record];
-- type T2 (X : positive) is new R (1, X) [with null record];
-- As explained in 6. above, T1 is rewritten as
-- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
-- which makes the treatment for T1 and T2 identical.
-- What we want when inheriting S, is that references to D1 and D2 in R are
-- replaced with references to their correct constraints, ie D1 and D2 in
-- T1 and 1 and X in T2. So all R's discriminant references are replaced
-- with either discriminant references in the derived type or expressions.
-- This replacement is acheived as follows: before inheriting R's
-- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
-- created in the scope of T1 (resp. scope of T2) so that discriminants D1
-- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
-- For T2, for instance, this has the effect of replacing String (D1 .. D2)
-- by String (1 .. X).
-- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
-- We explain here the rules governing private type extensions relevant to
-- type derivation. These rules are explained on the following example:
-- type D [(...)] is new A [(...)] with private; <-- partial view
-- type D [(...)] is new P [(...)] with null record; <-- full view
-- Type A is called the ancestor subtype of the private extension.
-- Type P is the parent type of the full view of the private extension. It
-- must be A or a type derived from A.
-- The rules concerning the discriminants of private type extensions are
-- [7.3(10-13)]:
-- o If a private extension inherits known discriminants from the ancestor
-- subtype, then the full view shall also inherit its discriminants from
-- the ancestor subtype and the parent subtype of the full view shall be
-- constrained if and only if the ancestor subtype is constrained.
-- o If a partial view has unknown discriminants, then the full view may
-- define a definite or an indefinite subtype, with or without
-- discriminants.
-- o If a partial view has neither known nor unknown discriminants, then
-- the full view shall define a definite subtype.
-- o If the ancestor subtype of a private extension has constrained
-- discrimiants, then the parent subtype of the full view shall impose a
-- statically matching constraint on those discriminants.
-- This means that only the following forms of private extensions are
-- allowed:
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- If A has no discriminants than P has no discriminants, otherwise P must
-- inherit A's discriminants.
-- type D is new A (...) with private; <-- partial view
-- type D is new P (:::) with null record; <-- full view
-- P must inherit A's discriminants and (...) and (:::) must statically
-- match.
-- subtype A is R (...);
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- P must have inherited R's discriminants and must be derived from A or
-- any of its subtypes.
-- type D (..) is new A with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- No specific constraints on P's discriminants or constraint (:::).
-- Note that A can be unconstrained, but the parent subtype P must either
-- be constrained or (:::) must be present.
-- type D (..) is new A [(...)] with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- P's constraints on A's discriminants must statically match those
-- imposed by (...).
-- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
-- The full view of a private extension is handled exactly as described
-- above. The model chose for the private view of a private extension
-- is the same for what concerns discriminants (ie they receive the same
-- treatment as in the tagged case). However, the private view of the
-- private extension always inherits the components of the parent base,
-- without replacing any discriminant reference. Strictly speacking this
-- is incorrect. However, Gigi never uses this view to generate code so
-- this is a purely semantic issue. In theory, a set of transformations
-- similar to those given in 5. and 6. above could be applied to private
-- views of private extensions to have the same model of component
-- inheritance as for non private extensions. However, this is not done
-- because it would further complicate private type processing.
-- Semantically speaking, this leaves us in an uncomfortable
-- situation. As an example consider:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type T is new R (1) with null record;
-- end;
-- This is transformed into:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type BaseT is new R with null record;
-- subtype T is BaseT (1);
-- end;
-- (strictly speaking the above is incorrect Ada).
-- From the semantic standpoint the private view of private extension T
-- should be flagged as constrained since one can clearly have
--
-- Obj : T;
--
-- in a unit withing Pack. However, when deriving subprograms for the
-- private view of private extension T, T must be seen as unconstrained
-- since T has discriminants (this is a constraint of the current
-- subprogram derivation model). Thus, when processing the private view of
-- a private extension such as T, we first mark T as unconstrained, we
-- process it, we perform program derivation and just before returning from
-- Build_Derived_Record_Type we mark T as constrained.
-- ??? Are there are other unconfortable cases that we will have to
-- deal with.
-- 10. RECORD_TYPE_WITH_PRIVATE complications.
-- Types that are derived from a visible record type and have a private
-- extension present other peculiarities. They behave mostly like private
-- types, but if they have primitive operations defined, these will not
-- have the proper signatures for further inheritance, because other
-- primitive operations will use the implicit base that we define for
-- private derivations below. This affect subprogram inheritance (see
-- Derive_Subprograms for details). We also derive the implicit base from
-- the base type of the full view, so that the implicit base is a record
-- type and not another private type, This avoids infinite loops.
procedure Build_Derived_Record_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Derive_Subps : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (N);
Parent_Base : Entity_Id;
Type_Def : Node_Id;
Indic : Node_Id;
Discrim : Entity_Id;
Last_Discrim : Entity_Id;
Constrs : Elist_Id;
Discs : Elist_Id := New_Elmt_List;
-- An empty Discs list means that there were no constraints in the
-- subtype indication or that there was an error processing it.
Assoc_List : Elist_Id;
New_Discrs : Elist_Id;
New_Base : Entity_Id;
New_Decl : Node_Id;
New_Indic : Node_Id;
Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
Discriminant_Specs : constant Boolean
:= Present (Discriminant_Specifications (N));
Private_Extension : constant Boolean
:= (Nkind (N) = N_Private_Extension_Declaration);
Constraint_Present : Boolean;
Inherit_Discrims : Boolean := False;
Save_Etype : Entity_Id;
Save_Discr_Constr : Elist_Id;
Save_Next_Entity : Entity_Id;
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Present (Full_View (Parent_Type))
and then Has_Discriminants (Parent_Type)
then
Parent_Base := Base_Type (Full_View (Parent_Type));
else
Parent_Base := Base_Type (Parent_Type);
end if;
-- Before we start the previously documented transformations, here is
-- a little fix for size and alignment of tagged types. Normally when
-- we derive type D from type P, we copy the size and alignment of P
-- as the default for D, and in the absence of explicit representation
-- clauses for D, the size and alignment are indeed the same as the
-- parent.
-- But this is wrong for tagged types, since fields may be added,
-- and the default size may need to be larger, and the default
-- alignment may need to be larger.
-- We therefore reset the size and alignment fields in the tagged
-- case. Note that the size and alignment will in any case be at
-- least as large as the parent type (since the derived type has
-- a copy of the parent type in the _parent field)
if Is_Tagged then
Init_Size_Align (Derived_Type);
end if;
-- STEP 0a: figure out what kind of derived type declaration we have.
if Private_Extension then
Type_Def := N;
Set_Ekind (Derived_Type, E_Record_Type_With_Private);
else
Type_Def := Type_Definition (N);
-- Ekind (Parent_Base) in not necessarily E_Record_Type since
-- Parent_Base can be a private type or private extension. However,
-- for tagged types with an extension the newly added fields are
-- visible and hence the Derived_Type is always an E_Record_Type.
-- (except that the parent may have its own private fields).
-- For untagged types we preserve the Ekind of the Parent_Base.
if Present (Record_Extension_Part (Type_Def)) then
Set_Ekind (Derived_Type, E_Record_Type);
else
Set_Ekind (Derived_Type, Ekind (Parent_Base));
end if;
end if;
-- Indic can either be an N_Identifier if the subtype indication
-- contains no constraint or an N_Subtype_Indication if the subtype
-- indication has a constraint.
Indic := Subtype_Indication (Type_Def);
Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
if Constraint_Present then
if not Has_Discriminants (Parent_Base) then
Error_Msg_N
("invalid constraint: type has no discriminant",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
elsif Is_Constrained (Parent_Type) then
Error_Msg_N
("invalid constraint: parent type is already constrained",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
end if;
end if;
-- STEP 0b: If needed, apply transformation given in point 5. above.
if not Private_Extension
and then Has_Discriminants (Parent_Type)
and then not Discriminant_Specs
and then (Is_Constrained (Parent_Type) or else Constraint_Present)
then
-- First, we must analyze the constraint (see comment in point 5.).
if Constraint_Present then
New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
if Has_Discriminants (Derived_Type)
and then Has_Private_Declaration (Derived_Type)
and then Present (Discriminant_Constraint (Derived_Type))
then
-- Verify that constraints of the full view conform to those
-- given in partial view.
declare
C1, C2 : Elmt_Id;
begin
C1 := First_Elmt (New_Discrs);
C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
while Present (C1) and then Present (C2) loop
if not
Fully_Conformant_Expressions (Node (C1), Node (C2))
then
Error_Msg_N (
"constraint not conformant to previous declaration",
Node (C1));
end if;
Next_Elmt (C1);
Next_Elmt (C2);
end loop;
end;
end if;
end if;
-- Insert and analyze the declaration for the unconstrained base type
New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
New_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => New_Base,
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Abstract_Present => Abstract_Present (Type_Def),
Subtype_Indication =>
New_Occurrence_Of (Parent_Base, Loc),
Record_Extension_Part =>
Relocate_Node (Record_Extension_Part (Type_Def))));
Set_Parent (New_Decl, Parent (N));
Mark_Rewrite_Insertion (New_Decl);
Insert_Before (N, New_Decl);
-- Note that this call passes False for the Derive_Subps
-- parameter because subprogram derivation is deferred until
-- after creating the subtype (see below).
Build_Derived_Type
(New_Decl, Parent_Base, New_Base,
Is_Completion => True, Derive_Subps => False);
-- ??? This needs re-examination to determine whether the
-- above call can simply be replaced by a call to Analyze.
Set_Analyzed (New_Decl);
-- Insert and analyze the declaration for the constrained subtype
if Constraint_Present then
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint => Relocate_Node (Constraint (Indic)));
else
declare
Expr : Node_Id;
Constr_List : List_Id := New_List;
C : Elmt_Id;
begin
C := First_Elmt (Discriminant_Constraint (Parent_Type));
while Present (C) loop
Expr := Node (C);
-- It is safe here to call New_Copy_Tree since
-- Force_Evaluation was called on each constraint in
-- Build_Discriminant_Constraints.
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (C);
end loop;
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
end;
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication => New_Indic));
Analyze (N);
-- Derivation of subprograms must be delayed until the
-- full subtype has been established to ensure proper
-- overriding of subprograms inherited by full types.
-- If the derivations occurred as part of the call to
-- Build_Derived_Type above, then the check for type
-- conformance would fail because earlier primitive
-- subprograms could still refer to the full type prior
-- the change to the new subtype and hence wouldn't
-- match the new base type created here.
Derive_Subprograms (Parent_Type, Derived_Type);
-- For tagged types the Discriminant_Constraint of the new base itype
-- is inherited from the first subtype so that no subtype conformance
-- problem arise when the first subtype overrides primitive
-- operations inherited by the implicit base type.
if Is_Tagged then
Set_Discriminant_Constraint
(New_Base, Discriminant_Constraint (Derived_Type));
end if;
return;
end if;
-- If we get here Derived_Type will have no discriminants or it will be
-- a discriminated unconstrained base type.
-- STEP 1a: perform preliminary actions/checks for derived tagged types
if Is_Tagged then
-- The parent type is frozen for non-private extensions (RM 13.14(7))
if not Private_Extension then
Freeze_Before (N, Parent_Type);
end if;
if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
and then not Is_Generic_Type (Derived_Type)
then
if Is_Controlled (Parent_Type) then
Error_Msg_N
("controlled type must be declared at the library level",
Indic);
else
Error_Msg_N
("type extension at deeper accessibility level than parent",
Indic);
end if;
else
declare
GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
begin
if Present (GB)
and then GB /= Enclosing_Generic_Body (Parent_Base)
then
Error_Msg_N
("parent type must not be outside generic body",
Indic);
end if;
end;
end if;
end if;
-- STEP 1b : preliminary cleanup of the full view of private types
-- If the type is already marked as having discriminants, then it's the
-- completion of a private type or private extension and we need to
-- retain the discriminants from the partial view if the current
-- declaration has Discriminant_Specifications so that we can verify
-- conformance. However, we must remove any existing components that
-- were inherited from the parent (and attached in Copy_Private_To_Full)
-- because the full type inherits all appropriate components anyway, and
-- we don't want the partial view's components interfering.
if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
Discrim := First_Discriminant (Derived_Type);
loop
Last_Discrim := Discrim;
Next_Discriminant (Discrim);
exit when No (Discrim);
end loop;
Set_Last_Entity (Derived_Type, Last_Discrim);
-- In all other cases wipe out the list of inherited components (even
-- inherited discriminants), it will be properly rebuilt here.
else
Set_First_Entity (Derived_Type, Empty);
Set_Last_Entity (Derived_Type, Empty);
end if;
-- STEP 1c: Initialize some flags for the Derived_Type
-- The following flags must be initialized here so that
-- Process_Discriminants can check that discriminants of tagged types
-- do not have a default initial value and that access discriminants
-- are only specified for limited records. For completeness, these
-- flags are also initialized along with all the other flags below.
Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
-- STEP 2a: process discriminants of derived type if any.
New_Scope (Derived_Type);
if Discriminant_Specs then
Set_Has_Unknown_Discriminants (Derived_Type, False);
-- The following call initializes fields Has_Discriminants and
-- Discriminant_Constraint, unless we are processing the completion
-- of a private type declaration.
Check_Or_Process_Discriminants (N, Derived_Type);
-- For non-tagged types the constraint on the Parent_Type must be
-- present and is used to rename the discriminants.
if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", Indic);
elsif not Is_Tagged and then not Constraint_Present then
Error_Msg_N
("discriminant constraint needed for derived untagged records",
Indic);
-- Otherwise the parent subtype must be constrained unless we have a
-- private extension.
elsif not Constraint_Present
and then not Private_Extension
and then not Is_Constrained (Parent_Type)
then
Error_Msg_N
("unconstrained type not allowed in this context", Indic);
elsif Constraint_Present then
-- The following call sets the field Corresponding_Discriminant
-- for the discriminants in the Derived_Type.
Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
-- For untagged types all new discriminants must rename
-- discriminants in the parent. For private extensions new
-- discriminants cannot rename old ones (implied by [7.3(13)]).
Discrim := First_Discriminant (Derived_Type);
while Present (Discrim) loop
if not Is_Tagged
and then not Present (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("new discriminants must constrain old ones", Discrim);
elsif Private_Extension
and then Present (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("Only static constraints allowed for parent"
& " discriminants in the partial view", Indic);
exit;
end if;
-- If a new discriminant is used in the constraint,
-- then its subtype must be statically compatible
-- with the parent discriminant's subtype (3.7(15)).
if Present (Corresponding_Discriminant (Discrim))
and then
not Subtypes_Statically_Compatible
(Etype (Discrim),
Etype (Corresponding_Discriminant (Discrim)))
then
Error_Msg_N
("subtype must be compatible with parent discriminant",
Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
end if;
-- STEP 2b: No new discriminants, inherit discriminants if any
else
if Private_Extension then
Set_Has_Unknown_Discriminants
(Derived_Type, Has_Unknown_Discriminants (Parent_Type)
or else Unknown_Discriminants_Present (N));
else
Set_Has_Unknown_Discriminants
(Derived_Type, Has_Unknown_Discriminants (Parent_Type));
end if;
if not Has_Unknown_Discriminants (Derived_Type)
and then Has_Discriminants (Parent_Type)
then
Inherit_Discrims := True;
Set_Has_Discriminants
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Base));
end if;
-- The following test is true for private types (remember
-- transformation 5. is not applied to those) and in an error
-- situation.
if Constraint_Present then
Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
end if;
-- For now mark a new derived type as cosntrained only if it has no
-- discriminants. At the end of Build_Derived_Record_Type we properly
-- set this flag in the case of private extensions. See comments in
-- point 9. just before body of Build_Derived_Record_Type.
Set_Is_Constrained
(Derived_Type,
not (Inherit_Discrims
or else Has_Unknown_Discriminants (Derived_Type)));
end if;
-- STEP 3: initialize fields of derived type.
Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
Set_Girder_Constraint (Derived_Type, No_Elist);
-- Fields inherited from the Parent_Type
Set_Discard_Names
(Derived_Type, Einfo.Discard_Names (Parent_Type));
Set_Has_Specified_Layout
(Derived_Type, Has_Specified_Layout (Parent_Type));
Set_Is_Limited_Composite
(Derived_Type, Is_Limited_Composite (Parent_Type));
Set_Is_Limited_Record
(Derived_Type, Is_Limited_Record (Parent_Type));
Set_Is_Private_Composite
(Derived_Type, Is_Private_Composite (Parent_Type));
-- Fields inherited from the Parent_Base
Set_Has_Controlled_Component
(Derived_Type, Has_Controlled_Component (Parent_Base));
Set_Has_Non_Standard_Rep
(Derived_Type, Has_Non_Standard_Rep (Parent_Base));
Set_Has_Primitive_Operations
(Derived_Type, Has_Primitive_Operations (Parent_Base));
-- Direct controlled types do not inherit the Finalize_Storage_Only
-- flag.
if not Is_Controlled (Parent_Type) then
Set_Finalize_Storage_Only (Derived_Type,
Finalize_Storage_Only (Parent_Type));
end if;
-- Set fields for private derived types.
if Is_Private_Type (Derived_Type) then
Set_Depends_On_Private (Derived_Type, True);
Set_Private_Dependents (Derived_Type, New_Elmt_List);
-- Inherit fields from non private record types. If this is the
-- completion of a derivation from a private type, the parent itself
-- is private, and the attributes come from its full view, which must
-- be present.
else
if Is_Private_Type (Parent_Base)
and then not Is_Record_Type (Parent_Base)
then
Set_Component_Alignment
(Derived_Type, Component_Alignment (Full_View (Parent_Base)));
Set_C_Pass_By_Copy
(Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
else
Set_Component_Alignment
(Derived_Type, Component_Alignment (Parent_Base));
Set_C_Pass_By_Copy
(Derived_Type, C_Pass_By_Copy (Parent_Base));
end if;
end if;
-- Set fields for tagged types.
if Is_Tagged then
Set_Primitive_Operations (Derived_Type, New_Elmt_List);
-- All tagged types defined in Ada.Finalization are controlled
if Chars (Scope (Derived_Type)) = Name_Finalization
and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
then
Set_Is_Controlled (Derived_Type);
else
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
end if;
Make_Class_Wide_Type (Derived_Type);
Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
if Has_Discriminants (Derived_Type)
and then Constraint_Present
then
Set_Girder_Constraint
(Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
end if;
else
Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
Set_Has_Non_Standard_Rep
(Derived_Type, Has_Non_Standard_Rep (Parent_Base));
end if;
-- STEP 4: Inherit components from the parent base and constrain them.
-- Apply the second transformation described in point 6. above.
if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
or else not Has_Discriminants (Parent_Type)
or else not Is_Constrained (Parent_Type)
then
Constrs := Discs;
else
Constrs := Discriminant_Constraint (Parent_Type);
end if;
Assoc_List := Inherit_Components (N,
Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
-- STEP 5a: Copy the parent record declaration for untagged types
if not Is_Tagged then
-- Discriminant_Constraint (Derived_Type) has been properly
-- constructed. Save it and temporarily set it to Empty because we do
-- not want the call to New_Copy_Tree below to mess this list.
if Has_Discriminants (Derived_Type) then
Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
Set_Discriminant_Constraint (Derived_Type, No_Elist);
else
Save_Discr_Constr := No_Elist;
end if;
-- Save the Etype field of Derived_Type. It is correctly set now, but
-- the call to New_Copy tree may remap it to point to itself, which
-- is not what we want. Ditto for the Next_Entity field.
Save_Etype := Etype (Derived_Type);
Save_Next_Entity := Next_Entity (Derived_Type);
-- Assoc_List maps all girder discriminants in the Parent_Base to
-- girder discriminants in the Derived_Type. It is fundamental that
-- no types or itypes with discriminants other than the girder
-- discriminants appear in the entities declared inside
-- Derived_Type. Gigi won't like it.
New_Decl :=
New_Copy_Tree
(Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
-- Restore the fields saved prior to the New_Copy_Tree call
-- and compute the girder constraint.
Set_Etype (Derived_Type, Save_Etype);
Set_Next_Entity (Derived_Type, Save_Next_Entity);
if Has_Discriminants (Derived_Type) then
Set_Discriminant_Constraint
(Derived_Type, Save_Discr_Constr);
Set_Girder_Constraint
(Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
end if;
-- Insert the new derived type declaration
Rewrite (N, New_Decl);
-- STEP 5b: Complete the processing for record extensions in generics
-- There is no completion for record extensions declared in the
-- parameter part of a generic, so we need to complete processing for
-- these generic record extensions here. The call to
-- Record_Type_Definition will change the Ekind of the components
-- from E_Void to E_Component.
elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
Record_Type_Definition (Empty, Derived_Type);
-- STEP 5c: Process the record extension for non private tagged types.
elsif not Private_Extension then
-- Add the _parent field in the derived type.
Expand_Derived_Record (Derived_Type, Type_Def);
-- Analyze the record extension
Record_Type_Definition
(Record_Extension_Part (Type_Def), Derived_Type);
end if;
End_Scope;
if Etype (Derived_Type) = Any_Type then
return;
end if;
-- Set delayed freeze and then derive subprograms, we need to do
-- this in this order so that derived subprograms inherit the
-- derived freeze if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
-- If we have a private extension which defines a constrained derived
-- type mark as constrained here after we have derived subprograms. See
-- comment on point 9. just above the body of Build_Derived_Record_Type.
if Private_Extension and then Inherit_Discrims then
if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
Set_Is_Constrained (Derived_Type, True);
Set_Discriminant_Constraint (Derived_Type, Discs);
elsif Is_Constrained (Parent_Type) then
Set_Is_Constrained
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
end Build_Derived_Record_Type;
------------------------
-- Build_Derived_Type --
------------------------
procedure Build_Derived_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
begin
-- Set common attributes
Set_Scope (Derived_Type, Current_Scope);
Set_Ekind (Derived_Type, Ekind (Parent_Base));
Set_Etype (Derived_Type, Parent_Base);
Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
Set_Size_Info (Derived_Type, Parent_Type);
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
Set_Convention (Derived_Type, Convention (Parent_Type));
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
case Ekind (Parent_Type) is
when Numeric_Kind =>
Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
when Array_Kind =>
Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
when E_Record_Type
| E_Record_Subtype
| Class_Wide_Kind =>
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
return;
when Enumeration_Kind =>
Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
when Access_Kind =>
Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
when Incomplete_Or_Private_Kind =>
Build_Derived_Private_Type
(N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
-- For discriminated types, the derivation includes deriving
-- primitive operations. For others it is done below.
if Is_Tagged_Type (Parent_Type)
or else Has_Discriminants (Parent_Type)
or else (Present (Full_View (Parent_Type))
and then Has_Discriminants (Full_View (Parent_Type)))
then
return;
end if;
when Concurrent_Kind =>
Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
when others =>
raise Program_Error;
end case;
if Etype (Derived_Type) = Any_Type then
return;
end if;
-- Set delayed freeze and then derive subprograms, we need to do
-- this in this order so that derived subprograms inherit the
-- derived freeze if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
Set_Has_Primitive_Operations
(Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
end Build_Derived_Type;
-----------------------
-- Build_Discriminal --
-----------------------
procedure Build_Discriminal (Discrim : Entity_Id) is
D_Minal : Entity_Id;
CR_Disc : Entity_Id;
begin
-- A discriminal has the same names as the discriminant.
D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
Set_Ekind (D_Minal, E_In_Parameter);
Set_Mechanism (D_Minal, Default_Mechanism);
Set_Etype (D_Minal, Etype (Discrim));
Set_Discriminal (Discrim, D_Minal);
Set_Discriminal_Link (D_Minal, Discrim);
-- For task types, build at once the discriminants of the corresponding
-- record, which are needed if discriminants are used in entry defaults
-- and in family bounds.
if Is_Concurrent_Type (Current_Scope)
or else Is_Limited_Type (Current_Scope)
then
CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
Set_Ekind (CR_Disc, E_In_Parameter);
Set_Mechanism (CR_Disc, Default_Mechanism);
Set_Etype (CR_Disc, Etype (Discrim));
Set_CR_Discriminant (Discrim, CR_Disc);
end if;
end Build_Discriminal;
------------------------------------
-- Build_Discriminant_Constraints --
------------------------------------
function Build_Discriminant_Constraints
(T : Entity_Id;
Def : Node_Id;
Derived_Def : Boolean := False)
return Elist_Id
is
C : constant Node_Id := Constraint (Def);
Nb_Discr : constant Nat := Number_Discriminants (T);
Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
-- Saves the expression corresponding to a given discriminant in T.
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
-- Return the Position number within array Discr_Expr of a discriminant
-- D within the discriminant list of the discriminated type T.
------------------
-- Pos_Of_Discr --
------------------
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
Disc : Entity_Id;
begin
Disc := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Disc = D then
return J;
end if;
Next_Discriminant (Disc);
end loop;
-- Note: Since this function is called on discriminants that are
-- known to belong to the discriminated type, falling through the
-- loop with no match signals an internal compiler error.
raise Program_Error;
end Pos_Of_Discr;
-- Variables local to Build_Discriminant_Constraints
Discr : Entity_Id;
E : Entity_Id;
Elist : Elist_Id := New_Elmt_List;
Constr : Node_Id;
Expr : Node_Id;
Id : Node_Id;
Position : Nat;
Found : Boolean;
Discrim_Present : Boolean := False;
-- Start of processing for Build_Discriminant_Constraints
begin
-- The following loop will process positional associations only.
-- For a positional association, the (single) discriminant is
-- implicitly specified by position, in textual order (RM 3.7.2).
Discr := First_Discriminant (T);
Constr := First (Constraints (C));
for D in Discr_Expr'Range loop
exit when Nkind (Constr) = N_Discriminant_Association;
if No (Constr) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
elsif Nkind (Constr) = N_Range
or else (Nkind (Constr) = N_Attribute_Reference
and then
Attribute_Name (Constr) = Name_Range)
then
Error_Msg_N
("a range is not a valid discriminant constraint", Constr);
Discr_Expr (D) := Error;
else
Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
Discr_Expr (D) := Constr;
end if;
Next_Discriminant (Discr);
Next (Constr);
end loop;
if No (Discr) and then Present (Constr) then
Error_Msg_N ("too many discriminants given in constraint", Constr);
return New_Elmt_List;
end if;
-- Named associations can be given in any order, but if both positional
-- and named associations are used in the same discriminant constraint,
-- then positional associations must occur first, at their normal
-- position. Hence once a named association is used, the rest of the
-- discriminant constraint must use only named associations.
while Present (Constr) loop
-- Positional association forbidden after a named association.
if Nkind (Constr) /= N_Discriminant_Association then
Error_Msg_N ("positional association follows named one", Constr);
return New_Elmt_List;
-- Otherwise it is a named association
else
-- E records the type of the discriminants in the named
-- association. All the discriminants specified in the same name
-- association must have the same type.
E := Empty;
-- Search the list of discriminants in T to see if the simple name
-- given in the constraint matches any of them.
Id := First (Selector_Names (Constr));
while Present (Id) loop
Found := False;
-- If Original_Discriminant is present, we are processing a
-- generic instantiation and this is an instance node. We need
-- to find the name of the corresponding discriminant in the
-- actual record type T and not the name of the discriminant in
-- the generic formal. Example:
--
-- generic
-- type G (D : int) is private;
-- package P is
-- subtype W is G (D => 1);
-- end package;
-- type Rec (X : int) is record ... end record;
-- package Q is new P (G => Rec);
--
-- At the point of the instantiation, formal type G is Rec
-- and therefore when reanalyzing "subtype W is G (D => 1);"
-- which really looks like "subtype W is Rec (D => 1);" at
-- the point of instantiation, we want to find the discriminant
-- that corresponds to D in Rec, ie X.
if Present (Original_Discriminant (Id)) then
Discr := Find_Corresponding_Discriminant (Id, T);
Found := True;
else
Discr := First_Discriminant (T);
while Present (Discr) loop
if Chars (Discr) = Chars (Id) then
Found := True;
exit;
end if;
Next_Discriminant (Discr);
end loop;
if not Found then
Error_Msg_N ("& does not match any discriminant", Id);
return New_Elmt_List;
-- The following is only useful for the benefit of generic
-- instances but it does not interfere with other
-- processing for the non-generic case so we do it in all
-- cases (for generics this statement is executed when
-- processing the generic definition, see comment at the
-- begining of this if statement).
else
Set_Original_Discriminant (Id, Discr);
end if;
end if;
Position := Pos_Of_Discr (T, Discr);
if Present (Discr_Expr (Position)) then
Error_Msg_N ("duplicate constraint for discriminant&", Id);
else
-- Each discriminant specified in the same named association
-- must be associated with a separate copy of the
-- corresponding expression.
if Present (Next (Id)) then
Expr := New_Copy_Tree (Expression (Constr));
Set_Parent (Expr, Parent (Expression (Constr)));
else
Expr := Expression (Constr);
end if;
Discr_Expr (Position) := Expr;
Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
end if;
-- A discriminant association with more than one discriminant
-- name is only allowed if the named discriminants are all of
-- the same type (RM 3.7.1(8)).
if E = Empty then
E := Base_Type (Etype (Discr));
elsif Base_Type (Etype (Discr)) /= E then
Error_Msg_N
("all discriminants in an association " &
"must have the same type", Id);
end if;
Next (Id);
end loop;
end if;
Next (Constr);
end loop;
-- A discriminant constraint must provide exactly one value for each
-- discriminant of the type (RM 3.7.1(8)).
for J in Discr_Expr'Range loop
if No (Discr_Expr (J)) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
end if;
end loop;
-- Determine if there are discriminant expressions in the constraint.
for J in Discr_Expr'Range loop
if Denotes_Discriminant (Discr_Expr (J)) then
Discrim_Present := True;
end if;
end loop;
-- Build an element list consisting of the expressions given in the
-- discriminant constraint and apply the appropriate range
-- checks. The list is constructed after resolving any named
-- discriminant associations and therefore the expressions appear in
-- the textual order of the discriminants.
Discr := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Discr_Expr (J) /= Error then
Append_Elmt (Discr_Expr (J), Elist);
-- If any of the discriminant constraints is given by a
-- discriminant and we are in a derived type declaration we
-- have a discriminant renaming. Establish link between new
-- and old discriminant.
if Denotes_Discriminant (Discr_Expr (J)) then
if Derived_Def then
Set_Corresponding_Discriminant
(Entity (Discr_Expr (J)), Discr);
end if;
-- Force the evaluation of non-discriminant expressions.
-- If we have found a discriminant in the constraint 3.4(26)
-- and 3.8(18) demand that no range checks are performed are
-- after evaluation. In all other cases perform a range check.
else
if not Discrim_Present then
Apply_Range_Check (Discr_Expr (J), Etype (Discr));
end if;
Force_Evaluation (Discr_Expr (J));
end if;
-- Check that the designated type of an access discriminant's
-- expression is not a class-wide type unless the discriminant's
-- designated type is also class-wide.
if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
and then not Is_Class_Wide_Type
(Designated_Type (Etype (Discr)))
and then Etype (Discr_Expr (J)) /= Any_Type
and then Is_Class_Wide_Type
(Designated_Type (Etype (Discr_Expr (J))))
then
Wrong_Type (Discr_Expr (J), Etype (Discr));
end if;
end if;
Next_Discriminant (Discr);
end loop;
return Elist;
end Build_Discriminant_Constraints;
---------------------------------
-- Build_Discriminated_Subtype --
---------------------------------
procedure Build_Discriminated_Subtype
(T : Entity_Id;
Def_Id : Entity_Id;
Elist : Elist_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
Has_Discrs : constant Boolean := Has_Discriminants (T);
Constrained : constant Boolean
:= (Has_Discrs and then not Is_Empty_Elmt_List (Elist))
or else Is_Constrained (T);
begin
if Ekind (T) = E_Record_Type then
if For_Access then
Set_Ekind (Def_Id, E_Private_Subtype);
Set_Is_For_Access_Subtype (Def_Id, True);
else
Set_Ekind (Def_Id, E_Record_Subtype);
end if;
elsif Ekind (T) = E_Task_Type then
Set_Ekind (Def_Id, E_Task_Subtype);
elsif Ekind (T) = E_Protected_Type then
Set_Ekind (Def_Id, E_Protected_Subtype);
elsif Is_Private_Type (T) then
Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
elsif Is_Class_Wide_Type (T) then
Set_Ekind (Def_Id, E_Class_Wide_Subtype);
else
-- Incomplete type. Attach subtype to list of dependents, to be
-- completed with full view of parent type.
Set_Ekind (Def_Id, Ekind (T));
Append_Elmt (Def_Id, Private_Dependents (T));
end if;
Set_Etype (Def_Id, T);
Init_Size_Align (Def_Id);
Set_Has_Discriminants (Def_Id, Has_Discrs);
Set_Is_Constrained (Def_Id, Constrained);
Set_First_Entity (Def_Id, First_Entity (T));
Set_Last_Entity (Def_Id, Last_Entity (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Def_Id);
Make_Class_Wide_Type (Def_Id);
end if;
Set_Girder_Constraint (Def_Id, No_Elist);
if Has_Discrs then
Set_Discriminant_Constraint (Def_Id, Elist);
Set_Girder_Constraint_From_Discriminant_Constraint (Def_Id);
end if;
if Is_Tagged_Type (T) then
Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
Set_Is_Abstract (Def_Id, Is_Abstract (T));
end if;
-- Subtypes introduced by component declarations do not need to be
-- marked as delayed, and do not get freeze nodes, because the semantics
-- verifies that the parents of the subtypes are frozen before the
-- enclosing record is frozen.
if not Is_Type (Scope (Def_Id)) then
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Conditional_Delay (Def_Id, Full_View (T));
else
Conditional_Delay (Def_Id, T);
end if;
end if;
if Is_Record_Type (T) then
Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
if Has_Discrs
and then not Is_Empty_Elmt_List (Elist)
and then not For_Access
then
Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
elsif not For_Access then
Set_Cloned_Subtype (Def_Id, T);
end if;
end if;
end Build_Discriminated_Subtype;
------------------------
-- Build_Scalar_Bound --
------------------------
function Build_Scalar_Bound
(Bound : Node_Id;
Par_T : Entity_Id;
Der_T : Entity_Id;
Loc : Source_Ptr)
return Node_Id
is
New_Bound : Entity_Id;
begin
-- Note: not clear why this is needed, how can the original bound
-- be unanalyzed at this point? and if it is, what business do we
-- have messing around with it? and why is the base type of the
-- parent type the right type for the resolution. It probably is
-- not! It is OK for the new bound we are creating, but not for
-- the old one??? Still if it never happens, no problem!
Analyze_And_Resolve (Bound, Base_Type (Par_T));
if Nkind (Bound) = N_Integer_Literal
or else Nkind (Bound) = N_Real_Literal
then
New_Bound := New_Copy (Bound);
Set_Etype (New_Bound, Der_T);
Set_Analyzed (New_Bound);
elsif Is_Entity_Name (Bound) then
New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
-- The following is almost certainly wrong. What business do we have
-- relocating a node (Bound) that is presumably still attached to
-- the tree elsewhere???
else
New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
end if;
Set_Etype (New_Bound, Der_T);
return New_Bound;
end Build_Scalar_Bound;
--------------------------------
-- Build_Underlying_Full_View --
--------------------------------
procedure Build_Underlying_Full_View
(N : Node_Id;
Typ : Entity_Id;
Par : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Subt : constant Entity_Id :=
Make_Defining_Identifier
(Loc, New_External_Name (Chars (Typ), 'S'));
Constr : Node_Id;
Indic : Node_Id;
C : Node_Id;
Id : Node_Id;
begin
if Nkind (N) = N_Full_Type_Declaration then
Constr := Constraint (Subtype_Indication (Type_Definition (N)));
-- ??? ??? is this assert right, I assume so otherwise Constr
-- would not be defined below (this used to be an elsif)
else pragma Assert (Nkind (N) = N_Subtype_Declaration);
Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
end if;
-- If the constraint has discriminant associations, the discriminant
-- entity is already set, but it denotes a discriminant of the new
-- type, not the original parent, so it must be found anew.
C := First (Constraints (Constr));
while Present (C) loop
if Nkind (C) = N_Discriminant_Association then
Id := First (Selector_Names (C));
while Present (Id) loop
Set_Original_Discriminant (Id, Empty);
Next (Id);
end loop;
end if;
Next (C);
end loop;
Indic := Make_Subtype_Declaration (Loc,
Defining_Identifier => Subt,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Par, Loc),
Constraint => New_Copy_Tree (Constr)));
Insert_Before (N, Indic);
Analyze (Indic);
Set_Underlying_Full_View (Typ, Full_View (Subt));
end Build_Underlying_Full_View;
-------------------------------
-- Check_Abstract_Overriding --
-------------------------------
procedure Check_Abstract_Overriding (T : Entity_Id) is
Op_List : Elist_Id;
Elmt : Elmt_Id;
Subp : Entity_Id;
Type_Def : Node_Id;
begin
Op_List := Primitive_Operations (T);
-- Loop to check primitive operations
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
-- Special exception, do not complain about failure to
-- override _Input and _Output, since we always provide
-- automatic overridings for these subprograms.
if Is_Abstract (Subp)
and then Chars (Subp) /= Name_uInput
and then Chars (Subp) /= Name_uOutput
and then not Is_Abstract (T)
then
if Present (Alias (Subp)) then
-- Only perform the check for a derived subprogram when
-- the type has an explicit record extension. This avoids
-- incorrectly flagging abstract subprograms for the case
-- of a type without an extension derived from a formal type
-- with a tagged actual (can occur within a private part).
Type_Def := Type_Definition (Parent (T));
if Nkind (Type_Def) = N_Derived_Type_Definition
and then Present (Record_Extension_Part (Type_Def))
then
Error_Msg_NE
("type must be declared abstract or & overridden",
T, Subp);
end if;
else
Error_Msg_NE
("abstract subprogram not allowed for type&",
Subp, T);
Error_Msg_NE
("nonabstract type has abstract subprogram&",
T, Subp);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end Check_Abstract_Overriding;
------------------------------------------------
-- Check_Access_Discriminant_Requires_Limited --
------------------------------------------------
procedure Check_Access_Discriminant_Requires_Limited
(D : Node_Id;
Loc : Node_Id)
is
begin
-- A discriminant_specification for an access discriminant
-- shall appear only in the declaration for a task or protected
-- type, or for a type with the reserved word 'limited' in
-- its definition or in one of its ancestors. (RM 3.7(10))
if Nkind (Discriminant_Type (D)) = N_Access_Definition
and then not Is_Concurrent_Type (Current_Scope)
and then not Is_Concurrent_Record_Type (Current_Scope)
and then not Is_Limited_Record (Current_Scope)
and then Ekind (Current_Scope) /= E_Limited_Private_Type
then
Error_Msg_N
("access discriminants allowed only for limited types", Loc);
end if;
end Check_Access_Discriminant_Requires_Limited;
-----------------------------------
-- Check_Aliased_Component_Types --
-----------------------------------
procedure Check_Aliased_Component_Types (T : Entity_Id) is
C : Entity_Id;
begin
-- ??? Also need to check components of record extensions,
-- but not components of protected types (which are always
-- limited).
if not Is_Limited_Type (T) then
if Ekind (T) = E_Record_Type then
C := First_Component (T);
while Present (C) loop
if Is_Aliased (C)
and then Has_Discriminants (Etype (C))
and then not Is_Constrained (Etype (C))
and then not In_Instance
then
Error_Msg_N
("aliased component must be constrained ('R'M 3.6(11))",
C);
end if;
Next_Component (C);
end loop;
elsif Ekind (T) = E_Array_Type then
if Has_Aliased_Components (T)
and then Has_Discriminants (Component_Type (T))
and then not Is_Constrained (Component_Type (T))
and then not In_Instance
then
Error_Msg_N
("aliased component type must be constrained ('R'M 3.6(11))",
T);
end if;
end if;
end if;
end Check_Aliased_Component_Types;
----------------------
-- Check_Completion --
----------------------
procedure Check_Completion (Body_Id : Node_Id := Empty) is
E : Entity_Id;
procedure Post_Error;
-- Post error message for lack of completion for entity E
procedure Post_Error is
begin
if not Comes_From_Source (E) then
if (Ekind (E) = E_Task_Type
or else Ekind (E) = E_Protected_Type)
then
-- It may be an anonymous protected type created for a
-- single variable. Post error on variable, if present.
declare
Var : Entity_Id;
begin
Var := First_Entity (Current_Scope);
while Present (Var) loop
exit when Etype (Var) = E
and then Comes_From_Source (Var);
Next_Entity (Var);
end loop;
if Present (Var) then
E := Var;
end if;
end;
end if;
end if;
-- If a generated entity has no completion, then either previous
-- semantic errors have disabled the expansion phase, or else
-- we had missing subunits, or else we are compiling without expan-
-- sion, or else something is very wrong.
if not Comes_From_Source (E) then
pragma Assert
(Errors_Detected > 0
or else Subunits_Missing
or else not Expander_Active);
return;
-- Here for source entity
else
-- Here if no body to post the error message, so we post the error
-- on the declaration that has no completion. This is not really
-- the right place to post it, think about this later ???
if No (Body_Id) then
if Is_Type (E) then
Error_Msg_NE
("missing full declaration for }", Parent (E), E);
else
Error_Msg_NE
("missing body for &", Parent (E), E);
end if;
-- Package body has no completion for a declaration that appears
-- in the corresponding spec. Post error on the body, with a
-- reference to the non-completed declaration.
else
Error_Msg_Sloc := Sloc (E);
if Is_Type (E) then
Error_Msg_NE
("missing full declaration for }!", Body_Id, E);
elsif Is_Overloadable (E)
and then Current_Entity_In_Scope (E) /= E
then
-- It may be that the completion is mistyped and appears
-- as a distinct overloading of the entity.
declare
Candidate : Entity_Id := Current_Entity_In_Scope (E);
Decl : Node_Id := Unit_Declaration_Node (Candidate);
begin
if Is_Overloadable (Candidate)
and then Ekind (Candidate) = Ekind (E)
and then Nkind (Decl) = N_Subprogram_Body
and then Acts_As_Spec (Decl)
then
Check_Type_Conformant (Candidate, E);
else
Error_Msg_NE ("missing body for & declared#!",
Body_Id, E);
end if;
end;
else
Error_Msg_NE ("missing body for & declared#!",
Body_Id, E);
end if;
end if;
end if;
end Post_Error;
-- Start processing for Check_Completion
begin
E := First_Entity (Current_Scope);
while Present (E) loop
if Is_Intrinsic_Subprogram (E) then
null;
-- The following situation requires special handling: a child
-- unit that appears in the context clause of the body of its
-- parent:
-- procedure Parent.Child (...);
--
-- with Parent.Child;
-- package body Parent is
-- Here Parent.Child appears as a local entity, but should not
-- be flagged as requiring completion, because it is a
-- compilation unit.
elsif Ekind (E) = E_Function
or else Ekind (E) = E_Procedure
or else Ekind (E) = E_Generic_Function
or else Ekind (E) = E_Generic_Procedure
then
if not Has_Completion (E)
and then not Is_Abstract (E)
and then Nkind (Parent (Unit_Declaration_Node (E))) /=
N_Compilation_Unit
and then Chars (E) /= Name_uSize
then
Post_Error;
end if;
elsif Is_Entry (E) then
if not Has_Completion (E) and then
(Ekind (Scope (E)) = E_Protected_Object
or else Ekind (Scope (E)) = E_Protected_Type)
then
Post_Error;
end if;
elsif Is_Package (E) then
if Unit_Requires_Body (E) then
if not Has_Completion (E)
and then Nkind (Parent (Unit_Declaration_Node (E))) /=
N_Compilation_Unit
then
Post_Error;
end if;
elsif not Is_Child_Unit (E) then
May_Need_Implicit_Body (E);
end if;
elsif Ekind (E) = E_Incomplete_Type
and then No (Underlying_Type (E))
then
Post_Error;
elsif (Ekind (E) = E_Task_Type or else
Ekind (E) = E_Protected_Type)
and then not Has_Completion (E)
then
Post_Error;
elsif Ekind (E) = E_Constant
and then Ekind (Etype (E)) = E_Task_Type
and then not Has_Completion (Etype (E))
then
Post_Error;
elsif Ekind (E) = E_Protected_Object
and then not Has_Completion (Etype (E))
then
Post_Error;
elsif Ekind (E) = E_Record_Type then
if Is_Tagged_Type (E) then
Check_Abstract_Overriding (E);
end if;
Check_Aliased_Component_Types (E);
elsif Ekind (E) = E_Array_Type then
Check_Aliased_Component_Types (E);
end if;
Next_Entity (E);
end loop;
end Check_Completion;
----------------------------
-- Check_Delta_Expression --
----------------------------
procedure Check_Delta_Expression (E : Node_Id) is
begin
if not (Is_Real_Type (Etype (E))) then
Wrong_Type (E, Any_Real);
elsif not Is_OK_Static_Expression (E) then
Error_Msg_N ("non-static expression used for delta value", E);
elsif not UR_Is_Positive (Expr_Value_R (E)) then
Error_Msg_N ("delta expression must be positive", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the real 0.1, which should prevent further errors.
Rewrite (E,
Make_Real_Literal (Sloc (E), Ureal_Tenth));
Analyze_And_Resolve (E, Standard_Float);
end Check_Delta_Expression;
-----------------------------
-- Check_Digits_Expression --
-----------------------------
procedure Check_Digits_Expression (E : Node_Id) is
begin
if not (Is_Integer_Type (Etype (E))) then
Wrong_Type (E, Any_Integer);
elsif not Is_OK_Static_Expression (E) then
Error_Msg_N ("non-static expression used for digits value", E);
elsif Expr_Value (E) <= 0 then
Error_Msg_N ("digits value must be greater than zero", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the integer 1, which should prevent further errors.
Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
Analyze_And_Resolve (E, Standard_Integer);
end Check_Digits_Expression;
----------------------
-- Check_Incomplete --
----------------------
procedure Check_Incomplete (T : Entity_Id) is
begin
if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
Error_Msg_N ("invalid use of type before its full declaration", T);
end if;
end Check_Incomplete;
--------------------------
-- Check_Initialization --
--------------------------
procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
begin
if (Is_Limited_Type (T)
or else Is_Limited_Composite (T))
and then not In_Instance
then
Error_Msg_N
("cannot initialize entities of limited type", Exp);
end if;
end Check_Initialization;
------------------------------------
-- Check_Or_Process_Discriminants --
------------------------------------
-- If an incomplete or private type declaration was already given for
-- the type, the discriminants may have already been processed if they
-- were present on the incomplete declaration. In this case a full
-- conformance check is performed otherwise just process them.
procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id) is
begin
if Has_Discriminants (T) then
-- Make the discriminants visible to component declarations.
declare
D : Entity_Id := First_Discriminant (T);
Prev : Entity_Id;
begin
while Present (D) loop
Prev := Current_Entity (D);
Set_Current_Entity (D);
Set_Is_Immediately_Visible (D);
Set_Homonym (D, Prev);
-- This restriction gets applied to the full type here; it
-- has already been applied earlier to the partial view
Check_Access_Discriminant_Requires_Limited (Parent (D), N);
Next_Discriminant (D);
end loop;
end;
elsif Present (Discriminant_Specifications (N)) then
Process_Discriminants (N);
end if;
end Check_Or_Process_Discriminants;
----------------------
-- Check_Real_Bound --
----------------------
procedure Check_Real_Bound (Bound : Node_Id) is
begin
if not Is_Real_Type (Etype (Bound)) then
Error_Msg_N
("bound in real type definition must be of real type", Bound);
elsif not Is_OK_Static_Expression (Bound) then
Error_Msg_N
("non-static expression used for real type bound", Bound);
else
return;
end if;
Rewrite
(Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
Analyze (Bound);
Resolve (Bound, Standard_Float);
end Check_Real_Bound;
------------------------------
-- Complete_Private_Subtype --
------------------------------
procedure Complete_Private_Subtype
(Priv : Entity_Id;
Full : Entity_Id;
Full_Base : Entity_Id;
Related_Nod : Node_Id)
is
Save_Next_Entity : Entity_Id;
Save_Homonym : Entity_Id;
begin
-- Set semantic attributes for (implicit) private subtype completion.
-- If the full type has no discriminants, then it is a copy of the full
-- view of the base. Otherwise, it is a subtype of the base with a
-- possible discriminant constraint. Save and restore the original
-- Next_Entity field of full to ensure that the calls to Copy_Node
-- do not corrupt the entity chain.
-- Note that the type of the full view is the same entity as the
-- type of the partial view. In this fashion, the subtype has
-- access to the correct view of the parent.
Save_Next_Entity := Next_Entity (Full);
Save_Homonym := Homonym (Priv);
case Ekind (Full_Base) is
when E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
Private_Kind |
Task_Kind |
Protected_Kind =>
Copy_Node (Priv, Full);
Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
Set_First_Entity (Full, First_Entity (Full_Base));
Set_Last_Entity (Full, Last_Entity (Full_Base));
when others =>
Copy_Node (Full_Base, Full);
Set_Chars (Full, Chars (Priv));
Conditional_Delay (Full, Priv);
Set_Sloc (Full, Sloc (Priv));
end case;
Set_Next_Entity (Full, Save_Next_Entity);
Set_Homonym (Full, Save_Homonym);
Set_Associated_Node_For_Itype (Full, Related_Nod);
-- Set common attributes for all subtypes.
Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
-- The Etype of the full view is inconsistent. Gigi needs to see the
-- structural full view, which is what the current scheme gives:
-- the Etype of the full view is the etype of the full base. However,
-- if the full base is a derived type, the full view then looks like
-- a subtype of the parent, not a subtype of the full base. If instead
-- we write:
-- Set_Etype (Full, Full_Base);
-- then we get inconsistencies in the front-end (confusion between
-- views). Several outstanding bugs are related to this.
Set_Is_First_Subtype (Full, False);
Set_Scope (Full, Scope (Priv));
Set_Size_Info (Full, Full_Base);
Set_RM_Size (Full, RM_Size (Full_Base));
Set_Is_Itype (Full);
-- A subtype of a private-type-without-discriminants, whose full-view
-- has discriminants with default expressions, is not constrained!
if not Has_Discriminants (Priv) then
Set_Is_Constrained (Full, Is_Constrained (Full_Base));
end if;
Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
Set_Depends_On_Private (Full, Has_Private_Component (Full));
-- Freeze the private subtype entity if its parent is delayed,
-- and not already frozen. We skip this processing if the type
-- is an anonymous subtype of a record component, or is the
-- corresponding record of a protected type, since ???
if not Is_Type (Scope (Full)) then
Set_Has_Delayed_Freeze (Full,
Has_Delayed_Freeze (Full_Base)
and then (not Is_Frozen (Full_Base)));
end if;
Set_Freeze_Node (Full, Empty);
Set_Is_Frozen (Full, False);
Set_Full_View (Priv, Full);
if Has_Discriminants (Full) then
Set_Girder_Constraint_From_Discriminant_Constraint (Full);
Set_Girder_Constraint (Priv, Girder_Constraint (Full));
if Has_Unknown_Discriminants (Full) then
Set_Discriminant_Constraint (Full, No_Elist);
end if;
end if;
if Ekind (Full_Base) = E_Record_Type
and then Has_Discriminants (Full_Base)
and then Has_Discriminants (Priv) -- might not, if errors
and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
then
Create_Constrained_Components
(Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
-- If the full base is itself derived from private, build a congruent
-- subtype of its underlying type, for use by the back end.
elsif Ekind (Full_Base) in Private_Kind
and then Is_Derived_Type (Full_Base)
and then Has_Discriminants (Full_Base)
and then
Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
then
Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
elsif Is_Record_Type (Full_Base) then
-- Show Full is simply a renaming of Full_Base.
Set_Cloned_Subtype (Full, Full_Base);
end if;
-- It is usafe to share to bounds of a scalar type, because the
-- Itype is elaborated on demand, and if a bound is non-static
-- then different orders of elaboration in different units will
-- lead to different external symbols.
if Is_Scalar_Type (Full_Base) then
Set_Scalar_Range (Full,
Make_Range (Sloc (Related_Nod),
Low_Bound => Duplicate_Subexpr (Type_Low_Bound (Full_Base)),
High_Bound => Duplicate_Subexpr (Type_High_Bound (Full_Base))));
end if;
-- ??? It seems that a lot of fields are missing that should be
-- copied from Full_Base to Full. Here are some that are introduced
-- in a non-disruptive way but a cleanup is necessary.
if Is_Tagged_Type (Full_Base) then
Set_Is_Tagged_Type (Full);
Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
elsif Is_Concurrent_Type (Full_Base) then
if Has_Discriminants (Full)
and then Present (Corresponding_Record_Type (Full_Base))
then
Set_Corresponding_Record_Type (Full,
Constrain_Corresponding_Record
(Full, Corresponding_Record_Type (Full_Base),
Related_Nod, Full_Base));
else
Set_Corresponding_Record_Type (Full,
Corresponding_Record_Type (Full_Base));
end if;
end if;
end Complete_Private_Subtype;
----------------------------
-- Constant_Redeclaration --
----------------------------
procedure Constant_Redeclaration
(Id : Entity_Id;
N : Node_Id;
T : out Entity_Id)
is
Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
Obj_Def : constant Node_Id := Object_Definition (N);
New_T : Entity_Id;
begin
if Nkind (Parent (Prev)) = N_Object_Declaration then
if Nkind (Object_Definition
(Parent (Prev))) = N_Subtype_Indication
then
-- Find type of new declaration. The constraints of the two
-- views must match statically, but there is no point in
-- creating an itype for the full view.
if Nkind (Obj_Def) = N_Subtype_Indication then
Find_Type (Subtype_Mark (Obj_Def));
New_T := Entity (Subtype_Mark (Obj_Def));
else
Find_Type (Obj_Def);
New_T := Entity (Obj_Def);
end if;
T := Etype (Prev);
else
-- The full view may impose a constraint, even if the partial
-- view does not, so construct the subtype.
New_T := Find_Type_Of_Object (Obj_Def, N);
T := New_T;
end if;
else
-- Current declaration is illegal, diagnosed below in Enter_Name.
T := Empty;
New_T := Any_Type;
end if;
-- If previous full declaration exists, or if a homograph is present,
-- let Enter_Name handle it, either with an error, or with the removal
-- of an overridden implicit subprogram.
if Ekind (Prev) /= E_Constant
or else Present (Expression (Parent (Prev)))
then
Enter_Name (Id);
-- Verify that types of both declarations match.
elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("type does not match declaration#", N);
Set_Full_View (Prev, Id);
Set_Etype (Id, Any_Type);
-- If so, process the full constant declaration
else
Set_Full_View (Prev, Id);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
Append_Entity (Id, Current_Scope);
-- Check ALIASED present if present before (RM 7.4(7))
if Is_Aliased (Prev)
and then not Aliased_Present (N)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("ALIASED required (see declaration#)", N);
end if;
-- Check that placement is in private part
if Ekind (Current_Scope) = E_Package
and then not In_Private_Part (Current_Scope)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("full constant for declaration#"
& " must be in private part", N);
end if;
end if;
end Constant_Redeclaration;
----------------------
-- Constrain_Access --
----------------------
procedure Constrain_Access
(Def_Id : in out Entity_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
Desig_Type : constant Entity_Id := Designated_Type (T);
Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
Constraint_OK : Boolean := True;
begin
if Is_Array_Type (Desig_Type) then
Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
elsif (Is_Record_Type (Desig_Type)
or else Is_Incomplete_Or_Private_Type (Desig_Type))
and then not Is_Constrained (Desig_Type)
then
-- ??? The following code is a temporary kludge to ignore
-- discriminant constraint on access type if
-- it is constraining the current record. Avoid creating the
-- implicit subtype of the record we are currently compiling
-- since right now, we cannot handle these.
-- For now, just return the access type itself.
if Desig_Type = Current_Scope
and then No (Def_Id)
then
Set_Ekind (Desig_Subtype, E_Record_Subtype);
Def_Id := Entity (Subtype_Mark (S));
-- This call added to ensure that the constraint is
-- analyzed (needed for a B test). Note that we
-- still return early from this procedure to avoid
-- recursive processing. ???
Constrain_Discriminated_Type
(Desig_Subtype, S, Related_Nod, For_Access => True);
return;
end if;
Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
For_Access => True);
elsif (Is_Task_Type (Desig_Type)
or else Is_Protected_Type (Desig_Type))
and then not Is_Constrained (Desig_Type)
then
Constrain_Concurrent
(Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
else
Error_Msg_N ("invalid constraint on access type", S);
Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
Constraint_OK := False;
end if;
if No (Def_Id) then
Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
else
Set_Ekind (Def_Id, E_Access_Subtype);
end if;
if Constraint_OK then
Set_Etype (Def_Id, Base_Type (T));
if Is_Private_Type (Desig_Type) then
Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
end if;
else
Set_Etype (Def_Id, Any_Type);
end if;
Set_Size_Info (Def_Id, T);
Set_Is_Constrained (Def_Id, Constraint_OK);
Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
-- Itypes created for constrained record components do not receive
-- a freeze node, they are elaborated when first seen.
if not Is_Record_Type (Current_Scope) then
Conditional_Delay (Def_Id, T);
end if;
end Constrain_Access;
---------------------
-- Constrain_Array --
---------------------
procedure Constrain_Array
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
C : constant Node_Id := Constraint (SI);
Number_Of_Constraints : Nat := 0;
Index : Node_Id;
S, T : Entity_Id;
Constraint_OK : Boolean := True;
begin
T := Entity (Subtype_Mark (SI));
if Ekind (T) in Access_Kind then
T := Designated_Type (T);
end if;
-- If an index constraint follows a subtype mark in a subtype indication
-- then the type or subtype denoted by the subtype mark must not already
-- impose an index constraint. The subtype mark must denote either an
-- unconstrained array type or an access type whose designated type
-- is such an array type... (RM 3.6.1)
if Is_Constrained (T) then
Error_Msg_N
("array type is already constrained", Subtype_Mark (SI));
Constraint_OK := False;
else
S := First (Constraints (C));
while Present (S) loop
Number_Of_Constraints := Number_Of_Constraints + 1;
Next (S);
end loop;
-- In either case, the index constraint must provide a discrete
-- range for each index of the array type and the type of each
-- discrete range must be the same as that of the corresponding
-- index. (RM 3.6.1)
if Number_Of_Constraints /= Number_Dimensions (T) then
Error_Msg_NE ("incorrect number of index constraints for }", C, T);
Constraint_OK := False;
else
S := First (Constraints (C));
Index := First_Index (T);
Analyze (Index);
-- Apply constraints to each index type
for J in 1 .. Number_Of_Constraints loop
Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
Next (Index);
Next (S);
end loop;
end if;
end if;
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
else
Set_Ekind (Def_Id, E_Array_Subtype);
end if;
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Etype (Def_Id, Base_Type (T));
if Constraint_OK then
Set_First_Index (Def_Id, First (Constraints (C)));
end if;
Set_Component_Type (Def_Id, Component_Type (T));
Set_Is_Constrained (Def_Id, True);
Set_Is_Aliased (Def_Id, Is_Aliased (T));
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
-- If the subtype is not that of a record component, build a freeze
-- node if parent still needs one.
-- If the subtype is not that of a record component, make sure
-- that the Depends_On_Private status is set (explanation ???)
-- and also that a conditional delay is set.
if not Is_Type (Scope (Def_Id)) then
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
Conditional_Delay (Def_Id, T);
end if;
end Constrain_Array;
------------------------------
-- Constrain_Component_Type --
------------------------------
function Constrain_Component_Type
(Compon_Type : Entity_Id;
Constrained_Typ : Entity_Id;
Related_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id)
return Entity_Id
is
Loc : constant Source_Ptr := Sloc (Constrained_Typ);
function Build_Constrained_Array_Type
(Old_Type : Entity_Id)
return Entity_Id;
-- If Old_Type is an array type, one of whose indices is
-- constrained by a discriminant, build an Itype whose constraint
-- replaces the discriminant with its value in the constraint.
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id)
return Entity_Id;
-- Ditto for record components.
function Build_Constrained_Access_Type
(Old_Type : Entity_Id)
return Entity_Id;
-- Ditto for access types. Makes use of previous two functions, to
-- constrain designated type.
function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
-- T is an array or discriminated type, C is a list of constraints
-- that apply to T. This routine builds the constrained subtype.
function Is_Discriminant (Expr : Node_Id) return Boolean;
-- Returns True if Expr is a discriminant.
function Get_Value (Discrim : Entity_Id) return Node_Id;
-- Find the value of discriminant Discrim in Constraint.
-----------------------------------
-- Build_Constrained_Access_Type --
-----------------------------------
function Build_Constrained_Access_Type
(Old_Type : Entity_Id)
return Entity_Id
is
Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
Itype : Entity_Id;
Desig_Subtype : Entity_Id;
Scop : Entity_Id;
begin
-- if the original access type was not embedded in the enclosing
-- type definition, there is no need to produce a new access
-- subtype. In fact every access type with an explicit constraint
-- generates an itype whose scope is the enclosing record.
if not Is_Type (Scope (Old_Type)) then
return Old_Type;
elsif Is_Array_Type (Desig_Type) then
Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
elsif Has_Discriminants (Desig_Type) then
-- This may be an access type to an enclosing record type for
-- which we are constructing the constrained components. Return
-- the enclosing record subtype. This is not always correct,
-- but avoids infinite recursion. ???
Desig_Subtype := Any_Type;
for J in reverse 0 .. Scope_Stack.Last loop
Scop := Scope_Stack.Table (J).Entity;
if Is_Type (Scop)
and then Base_Type (Scop) = Base_Type (Desig_Type)
then
Desig_Subtype := Scop;
end if;
exit when not Is_Type (Scop);
end loop;
if Desig_Subtype = Any_Type then
Desig_Subtype :=
Build_Constrained_Discriminated_Type (Desig_Type);
end if;
else
return Old_Type;
end if;
if Desig_Subtype /= Desig_Type then
-- The Related_Node better be here or else we won't be able
-- to attach new itypes to a node in the tree.
pragma Assert (Present (Related_Node));
Itype := Create_Itype (E_Access_Subtype, Related_Node);
Set_Etype (Itype, Base_Type (Old_Type));
Set_Size_Info (Itype, (Old_Type));
Set_Directly_Designated_Type (Itype, Desig_Subtype);
Set_Depends_On_Private (Itype, Has_Private_Component
(Old_Type));
Set_Is_Access_Constant (Itype, Is_Access_Constant
(Old_Type));
-- The new itype needs freezing when it depends on a not frozen
-- type and the enclosing subtype needs freezing.
if Has_Delayed_Freeze (Constrained_Typ)
and then not Is_Frozen (Constrained_Typ)
then
Conditional_Delay (Itype, Base_Type (Old_Type));
end if;
return Itype;
else
return Old_Type;
end if;
end Build_Constrained_Access_Type;
----------------------------------
-- Build_Constrained_Array_Type --
----------------------------------
function Build_Constrained_Array_Type
(Old_Type : Entity_Id)
return Entity_Id
is
Lo_Expr : Node_Id;
Hi_Expr : Node_Id;
Old_Index : Node_Id;
Range_Node : Node_Id;
Constr_List : List_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr)
or else Is_Discriminant (Hi_Expr)
then
Need_To_Create_Itype := True;
end if;
Next_Index (Old_Index);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr) then
Lo_Expr := Get_Value (Lo_Expr);
end if;
if Is_Discriminant (Hi_Expr) then
Hi_Expr := Get_Value (Hi_Expr);
end if;
Range_Node :=
Make_Range
(Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
Append (Range_Node, To => Constr_List);
Next_Index (Old_Index);
end loop;
return Build_Subtype (Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Array_Type;
------------------------------------------
-- Build_Constrained_Discriminated_Type --
------------------------------------------
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id)
return Entity_Id
is
Expr : Node_Id;
Constr_List : List_Id;
Old_Constraint : Elmt_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Need_To_Create_Itype := True;
end if;
Next_Elmt (Old_Constraint);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Expr := Get_Value (Expr);
end if;
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (Old_Constraint);
end loop;
return Build_Subtype (Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Discriminated_Type;
-------------------
-- Build_Subtype --
-------------------
function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
Indic : Node_Id;
Subtyp_Decl : Node_Id;
Def_Id : Entity_Id;
Btyp : Entity_Id := Base_Type (T);
begin
-- The Related_Node better be here or else we won't be able
-- to attach new itypes to a node in the tree.
pragma Assert (Present (Related_Node));
-- If the view of the component's type is incomplete or private
-- with unknown discriminants, then the constraint must be applied
-- to the full type.
if Has_Unknown_Discriminants (Btyp)
and then Present (Underlying_Type (Btyp))
then
Btyp := Underlying_Type (Btyp);
end if;
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
Def_Id := Create_Itype (Ekind (T), Related_Node);
Subtyp_Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Indic);
Set_Parent (Subtyp_Decl, Parent (Related_Node));
-- Itypes must be analyzed with checks off (see itypes.ads).
Analyze (Subtyp_Decl, Suppress => All_Checks);
return Def_Id;
end Build_Subtype;
---------------
-- Get_Value --
---------------
function Get_Value (Discrim : Entity_Id) return Node_Id is
D : Entity_Id := First_Discriminant (Typ);
E : Elmt_Id := First_Elmt (Constraints);
begin
while Present (D) loop
-- If we are constraining the subtype of a derived tagged type,
-- recover the discriminant of the parent, which appears in
-- the constraint of an inherited component.
if D = Entity (Discrim)
or else Corresponding_Discriminant (D) = Entity (Discrim)
then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
-- Something is wrong if we did not find the value
raise Program_Error;
end Get_Value;
---------------------
-- Is_Discriminant --
---------------------
function Is_Discriminant (Expr : Node_Id) return Boolean is
Discrim_Scope : Entity_Id;
begin
if Denotes_Discriminant (Expr) then
Discrim_Scope := Scope (Entity (Expr));
-- Either we have a reference to one of Typ's discriminants,
pragma Assert (Discrim_Scope = Typ
-- or to the discriminants of the parent type, in the case
-- of a derivation of a tagged type with variants.
or else Discrim_Scope = Etype (Typ)
or else Full_View (Discrim_Scope) = Etype (Typ)
-- or same as above for the case where the discriminants
-- were declared in Typ's private view.
or else (Is_Private_Type (Discrim_Scope)
and then Chars (Discrim_Scope) = Chars (Typ))
-- or else we are deriving from the full view and the
-- discriminant is declared in the private entity.
or else (Is_Private_Type (Typ)
and then Chars (Discrim_Scope) = Chars (Typ))
-- or we have a class-wide type, in which case make sure the
-- discriminant found belongs to the root type.
or else (Is_Class_Wide_Type (Typ)
and then Etype (Typ) = Discrim_Scope));
return True;
end if;
-- In all other cases we have something wrong.
return False;
end Is_Discriminant;
-- Start of processing for Constrain_Component_Type
begin
if Is_Array_Type (Compon_Type) then
return Build_Constrained_Array_Type (Compon_Type);
elsif Has_Discriminants (Compon_Type) then
return Build_Constrained_Discriminated_Type (Compon_Type);
elsif Is_Access_Type (Compon_Type) then
return Build_Constrained_Access_Type (Compon_Type);
end if;
return Compon_Type;
end Constrain_Component_Type;
--------------------------
-- Constrain_Concurrent --
--------------------------
-- For concurrent types, the associated record value type carries the same
-- discriminants, so when we constrain a concurrent type, we must constrain
-- the value type as well.
procedure Constrain_Concurrent
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
T_Val : Entity_Id;
begin
if Ekind (T_Ent) in Access_Kind then
T_Ent := Designated_Type (T_Ent);
end if;
T_Val := Corresponding_Record_Type (T_Ent);
if Present (T_Val) then
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Corresponding_Record_Type (Def_Id,
Constrain_Corresponding_Record
(Def_Id, T_Val, Related_Nod, Related_Id));
else
-- If there is no associated record, expansion is disabled and this
-- is a generic context. Create a subtype in any case, so that
-- semantic analysis can proceed.
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
end if;
end Constrain_Concurrent;
------------------------------------
-- Constrain_Corresponding_Record --
------------------------------------
function Constrain_Corresponding_Record
(Prot_Subt : Entity_Id;
Corr_Rec : Entity_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id)
return Entity_Id
is
T_Sub : constant Entity_Id
:= Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
begin
Set_Etype (T_Sub, Corr_Rec);
Init_Size_Align (T_Sub);
Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
Set_Is_Constrained (T_Sub, True);
Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
Conditional_Delay (T_Sub, Corr_Rec);
if Has_Discriminants (Prot_Subt) then -- False only if errors.
Set_Discriminant_Constraint (T_Sub,
Discriminant_Constraint (Prot_Subt));
Set_Girder_Constraint_From_Discriminant_Constraint (T_Sub);
Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
Discriminant_Constraint (T_Sub));
end if;
Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
return T_Sub;
end Constrain_Corresponding_Record;
-----------------------
-- Constrain_Decimal --
-----------------------
procedure Constrain_Decimal
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
Loc : constant Source_Ptr := Sloc (C);
Range_Expr : Node_Id;
Digits_Expr : Node_Id;
Digits_Val : Uint;
Bound_Val : Ureal;
begin
Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
if Nkind (C) = N_Range_Constraint then
Range_Expr := Range_Expression (C);
Digits_Val := Digits_Value (T);
else
pragma Assert (Nkind (C) = N_Digits_Constraint);
Digits_Expr := Digits_Expression (C);
Analyze_And_Resolve (Digits_Expr, Any_Integer);
Check_Digits_Expression (Digits_Expr);
Digits_Val := Expr_Value (Digits_Expr);
if Digits_Val > Digits_Value (T) then
Error_Msg_N
("digits expression is incompatible with subtype", C);
Digits_Val := Digits_Value (T);
end if;
if Present (Range_Constraint (C)) then
Range_Expr := Range_Expression (Range_Constraint (C));
else
Range_Expr := Empty;
end if;
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Delta_Value (Def_Id, Delta_Value (T));
Set_Scale_Value (Def_Id, Scale_Value (T));
Set_Small_Value (Def_Id, Small_Value (T));
Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
Set_Digits_Value (Def_Id, Digits_Val);
-- Manufacture range from given digits value if no range present
if No (Range_Expr) then
Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
Range_Expr :=
Make_Range (Loc,
Low_Bound =>
Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
High_Bound =>
Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
end if;
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T, Related_Nod);
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Decimal;
----------------------------------
-- Constrain_Discriminated_Type --
----------------------------------
procedure Constrain_Discriminated_Type
(Def_Id : Entity_Id;
S : Node_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
T : Entity_Id;
C : Node_Id;
Elist : Elist_Id := New_Elmt_List;
procedure Fixup_Bad_Constraint;
-- This is called after finding a bad constraint, and after having
-- posted an appropriate error message. The mission is to leave the
-- entity T in as reasonable state as possible!
procedure Fixup_Bad_Constraint is
begin
-- Set a reasonable Ekind for the entity. For an incomplete type,
-- we can't do much, but for other types, we can set the proper
-- corresponding subtype kind.
if Ekind (T) = E_Incomplete_Type then
Set_Ekind (Def_Id, Ekind (T));
else
Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
end if;
Set_Etype (Def_Id, Any_Type);
Set_Error_Posted (Def_Id);
end Fixup_Bad_Constraint;
-- Start of processing for Constrain_Discriminated_Type
begin
C := Constraint (S);
-- A discriminant constraint is only allowed in a subtype indication,
-- after a subtype mark. This subtype mark must denote either a type
-- with discriminants, or an access type whose designated type is a
-- type with discriminants. A discriminant constraint specifies the
-- values of these discriminants (RM 3.7.2(5)).
T := Base_Type (Entity (Subtype_Mark (S)));
if Ekind (T) in Access_Kind then
T := Designated_Type (T);
end if;
if not Has_Discriminants (T) then
Error_Msg_N ("invalid constraint: type has no discriminant", C);
Fixup_Bad_Constraint;
return;
elsif Is_Constrained (Entity (Subtype_Mark (S))) then
Error_Msg_N ("type is already constrained", Subtype_Mark (S));
Fixup_Bad_Constraint;
return;
end if;
-- T may be an unconstrained subtype (e.g. a generic actual).
-- Constraint applies to the base type.
T := Base_Type (T);
Elist := Build_Discriminant_Constraints (T, S);
-- If the list returned was empty we had an error in building the
-- discriminant constraint. We have also already signalled an error
-- in the incomplete type case
if Is_Empty_Elmt_List (Elist) then
Fixup_Bad_Constraint;
return;
end if;
Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
end Constrain_Discriminated_Type;
---------------------------
-- Constrain_Enumeration --
---------------------------
procedure Constrain_Enumeration
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_Scalar_Range_For_Subtype
(Def_Id, Range_Expression (C), T, Related_Nod);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Enumeration;
----------------------
-- Constrain_Float --
----------------------
procedure Constrain_Float
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Set_Ekind (Def_Id, E_Floating_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
-- Process the constraint
C := Constraint (S);
-- Digits constraint present
if Nkind (C) = N_Digits_Constraint then
D := Digits_Expression (C);
Analyze_And_Resolve (D, Any_Integer);
Check_Digits_Expression (D);
Set_Digits_Value (Def_Id, Expr_Value (D));
-- Check that digits value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this!
if Digits_Value (Def_Id) > Digits_Value (T) then
Error_Msg_Uint_1 := Digits_Value (T);
Error_Msg_N ("?digits value is too large, maximum is ^", D);
Rais := Make_Raise_Constraint_Error (Sloc (D));
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No digits constraint present
else
Set_Digits_Value (Def_Id, Digits_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype
(Def_Id, Range_Expression (C), T, Related_Nod);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Is_Constrained (Def_Id);
end Constrain_Float;
---------------------
-- Constrain_Index --
---------------------
procedure Constrain_Index
(Index : Node_Id;
S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character;
Suffix_Index : Nat)
is
Def_Id : Entity_Id;
R : Node_Id := Empty;
Checks_Off : Boolean := False;
T : constant Entity_Id := Etype (Index);
begin
if Nkind (S) = N_Range
or else Nkind (S) = N_Attribute_Reference
then
-- A Range attribute will transformed into N_Range by Resolve.
Analyze (S);
Set_Etype (S, T);
R := S;
-- ??? Why on earth do we turn checks of in this very specific case ?
-- From the revision history: (Constrain_Index): Call
-- Process_Range_Expr_In_Decl with range checking off for range
-- bounds that are attributes. This avoids some horrible
-- constraint error checks.
if Nkind (R) = N_Range
and then Nkind (Low_Bound (R)) = N_Attribute_Reference
and then Nkind (High_Bound (R)) = N_Attribute_Reference
then
Checks_Off := True;
end if;
Process_Range_Expr_In_Decl
(R, T, Related_Nod, Empty_List, Checks_Off);
if not Error_Posted (S)
and then
(Nkind (S) /= N_Range
or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
then
if Base_Type (T) /= Any_Type
and then Etype (Low_Bound (S)) /= Any_Type
and then Etype (High_Bound (S)) /= Any_Type
then
Error_Msg_N ("range expected", S);
end if;
end if;
elsif Nkind (S) = N_Subtype_Indication then
-- the parser has verified that this is a discrete indication.
Resolve_Discrete_Subtype_Indication (S, T);
R := Range_Expression (Constraint (S));
elsif Nkind (S) = N_Discriminant_Association then
-- syntactically valid in subtype indication.
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
-- Subtype_Mark case, no anonymous subtypes to construct
else
Analyze (S);
if Is_Entity_Name (S) then
if not Is_Type (Entity (S)) then
Error_Msg_N ("expect subtype mark for index constraint", S);
elsif Base_Type (Entity (S)) /= Base_Type (T) then
Wrong_Type (S, Base_Type (T));
end if;
return;
else
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
end if;
end if;
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
elsif Is_Integer_Type (T) then
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
end if;
Set_Size_Info (Def_Id, (T));
Set_RM_Size (Def_Id, RM_Size (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Scalar_Range (Def_Id, R);
Set_Etype (S, Def_Id);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Index;
-----------------------
-- Constrain_Integer --
-----------------------
procedure Constrain_Integer
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Set_Scalar_Range_For_Subtype
(Def_Id, Range_Expression (C), T, Related_Nod);
if Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Discrete_RM_Size (Def_Id);
end Constrain_Integer;
------------------------------
-- Constrain_Ordinary_Fixed --
------------------------------
procedure Constrain_Ordinary_Fixed
(Def_Id : Node_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Small_Value (Def_Id, Small_Value (T));
-- Process the constraint
C := Constraint (S);
-- Delta constraint present
if Nkind (C) = N_Delta_Constraint then
D := Delta_Expression (C);
Analyze_And_Resolve (D, Any_Real);
Check_Delta_Expression (D);
Set_Delta_Value (Def_Id, Expr_Value_R (D));
-- Check that delta value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this!
if Delta_Value (Def_Id) < Delta_Value (T) then
Error_Msg_N ("?delta value is too small", D);
Rais := Make_Raise_Constraint_Error (Sloc (D));
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No delta constraint present
else
Set_Delta_Value (Def_Id, Delta_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype
(Def_Id, Range_Expression (C), T, Related_Nod);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Ordinary_Fixed;
---------------------------
-- Convert_Scalar_Bounds --
---------------------------
procedure Convert_Scalar_Bounds
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Loc : Source_Ptr)
is
Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
Lo : Node_Id;
Hi : Node_Id;
Rng : Node_Id;
begin
Lo := Build_Scalar_Bound
(Type_Low_Bound (Derived_Type),
Parent_Type, Implicit_Base, Loc);
Hi := Build_Scalar_Bound
(Type_High_Bound (Derived_Type),
Parent_Type, Implicit_Base, Loc);
Rng :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
Set_Parent (Rng, N);
Set_Scalar_Range (Derived_Type, Rng);
-- Analyze the bounds
Analyze_And_Resolve (Lo, Implicit_Base);
Analyze_And_Resolve (Hi, Implicit_Base);
-- Analyze the range itself, except that we do not analyze it if
-- the bounds are real literals, and we have a fixed-point type.
-- The reason for this is that we delay setting the bounds in this
-- case till we know the final Small and Size values (see circuit
-- in Freeze.Freeze_Fixed_Point_Type for further details).
if Is_Fixed_Point_Type (Parent_Type)
and then Nkind (Lo) = N_Real_Literal
and then Nkind (Hi) = N_Real_Literal
then
return;
-- Here we do the analysis of the range.
-- Note: we do this manually, since if we do a normal Analyze and
-- Resolve call, there are problems with the conversions used for
-- the derived type range.
else
Set_Etype (Rng, Implicit_Base);
Set_Analyzed (Rng, True);
end if;
end Convert_Scalar_Bounds;
-------------------
-- Copy_And_Swap --
-------------------
procedure Copy_And_Swap (Privat, Full : Entity_Id) is
begin
-- Initialize new full declaration entity by copying the pertinent
-- fields of the corresponding private declaration entity.
Copy_Private_To_Full (Privat, Full);
-- Swap the two entities. Now Privat is the full type entity and
-- Full is the private one. They will be swapped back at the end
-- of the private part. This swapping ensures that the entity that
-- is visible in the private part is the full declaration.
Exchange_Entities (Privat, Full);
Append_Entity (Full, Scope (Full));
end Copy_And_Swap;
-------------------------------------
-- Copy_Array_Base_Type_Attributes --
-------------------------------------
procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
begin
Set_Component_Alignment (T1, Component_Alignment (T2));
Set_Component_Type (T1, Component_Type (T2));
Set_Component_Size (T1, Component_Size (T2));
Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
Set_Has_Task (T1, Has_Task (T2));
Set_Is_Packed (T1, Is_Packed (T2));
Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
end Copy_Array_Base_Type_Attributes;
-----------------------------------
-- Copy_Array_Subtype_Attributes --
-----------------------------------
procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
begin
Set_Size_Info (T1, T2);
Set_First_Index (T1, First_Index (T2));
Set_Is_Aliased (T1, Is_Aliased (T2));
Set_Is_Atomic (T1, Is_Atomic (T2));
Set_Is_Volatile (T1, Is_Volatile (T2));
Set_Is_Constrained (T1, Is_Constrained (T2));
Set_Depends_On_Private (T1, Has_Private_Component (T2));
Set_First_Rep_Item (T1, First_Rep_Item (T2));
Set_Convention (T1, Convention (T2));
Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
end Copy_Array_Subtype_Attributes;
--------------------------
-- Copy_Private_To_Full --
--------------------------
procedure Copy_Private_To_Full (Priv, Full : Entity_Id) is
begin
-- We temporarily set Ekind to a value appropriate for a type to
-- avoid assert failures in Einfo from checking for setting type
-- attributes on something that is not a type. Ekind (Priv) is an
-- appropriate choice, since it allowed the attributes to be set
-- in the first place. This Ekind value will be modified later.
Set_Ekind (Full, Ekind (Priv));
-- Also set Etype temporarily to Any_Type, again, in the absence
-- of errors, it will be properly reset, and if there are errors,
-- then we want a value of Any_Type to remain.
Set_Etype (Full, Any_Type);
-- Now start copying attributes
Set_Has_Discriminants (Full, Has_Discriminants (Priv));
if Has_Discriminants (Full) then
Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
Set_Girder_Constraint (Full, Girder_Constraint (Priv));
end if;
Set_Homonym (Full, Homonym (Priv));
Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
Set_Is_Public (Full, Is_Public (Priv));
Set_Is_Pure (Full, Is_Pure (Priv));
Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
Conditional_Delay (Full, Priv);
if Is_Tagged_Type (Full) then
Set_Primitive_Operations (Full, Primitive_Operations (Priv));
if Priv = Base_Type (Priv) then
Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
end if;
end if;
Set_Is_Volatile (Full, Is_Volatile (Priv));
Set_Scope (Full, Scope (Priv));
Set_Next_Entity (Full, Next_Entity (Priv));
Set_First_Entity (Full, First_Entity (Priv));
Set_Last_Entity (Full, Last_Entity (Priv));
-- If access types have been recorded for later handling, keep them
-- in the full view so that they get handled when the full view freeze
-- node is expanded.
if Present (Freeze_Node (Priv))
and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
then
Ensure_Freeze_Node (Full);
Set_Access_Types_To_Process (Freeze_Node (Full),
Access_Types_To_Process (Freeze_Node (Priv)));
end if;
end Copy_Private_To_Full;
-----------------------------------
-- Create_Constrained_Components --
-----------------------------------
procedure Create_Constrained_Components
(Subt : Entity_Id;
Decl_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id)
is
Loc : constant Source_Ptr := Sloc (Subt);
Assoc_List : List_Id := New_List;
Comp_List : Elist_Id := New_Elmt_List;
Discr_Val : Elmt_Id;
Errors : Boolean;
New_C : Entity_Id;
Old_C : Entity_Id;
Is_Static : Boolean := True;
Parent_Type : constant Entity_Id := Etype (Typ);
procedure Collect_Fixed_Components (Typ : Entity_Id);
-- Collect components of parent type that do not appear in a variant
-- part.
procedure Create_All_Components;
-- Iterate over Comp_List to create the components of the subtype.
function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
-- Creates a new component from Old_Compon, coppying all the fields from
-- it, including its Etype, inserts the new component in the Subt entity
-- chain and returns the new component.
function Is_Variant_Record (T : Entity_Id) return Boolean;
-- If true, and discriminants are static, collect only components from
-- variants selected by discriminant values.
------------------------------
-- Collect_Fixed_Components --
------------------------------
procedure Collect_Fixed_Components (Typ : Entity_Id) is
begin
-- Build association list for discriminants, and find components of
-- the variant part selected by the values of the discriminants.
Old_C := First_Discriminant (Typ);
Discr_Val := First_Elmt (Constraints);
while Present (Old_C) loop
Append_To (Assoc_List,
Make_Component_Association (Loc,
Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
Expression => New_Copy (Node (Discr_Val))));
Next_Elmt (Discr_Val);
Next_Discriminant (Old_C);
end loop;
-- The tag, and the possible parent and controller components
-- are unconditionally in the subtype.
if Is_Tagged_Type (Typ)
or else Has_Controlled_Component (Typ)
then
Old_C := First_Component (Typ);
while Present (Old_C) loop
if Chars ((Old_C)) = Name_uTag
or else Chars ((Old_C)) = Name_uParent
or else Chars ((Old_C)) = Name_uController
then
Append_Elmt (Old_C, Comp_List);
end if;
Next_Component (Old_C);
end loop;
end if;
end Collect_Fixed_Components;
---------------------------
-- Create_All_Components --
---------------------------
procedure Create_All_Components is
Comp : Elmt_Id;
begin
Comp := First_Elmt (Comp_List);
while Present (Comp) loop
Old_C := Node (Comp);
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Elmt (Comp);
end loop;
end Create_All_Components;
----------------------
-- Create_Component --
----------------------
function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
New_Compon : Entity_Id := New_Copy (Old_Compon);
begin
-- Set the parent so we have a proper link for freezing etc. This
-- is not a real parent pointer, since of course our parent does
-- not own up to us and reference us, we are an illegitimate
-- child of the original parent!
Set_Parent (New_Compon, Parent (Old_Compon));
-- We do not want this node marked as Comes_From_Source, since
-- otherwise it would get first class status and a separate
-- cross-reference line would be generated. Illegitimate
-- children do not rate such recognition.
Set_Comes_From_Source (New_Compon, False);
-- But it is a real entity, and a birth certificate must be
-- properly registered by entering it into the entity list.
Enter_Name (New_Compon);
return New_Compon;
end Create_Component;
-----------------------
-- Is_Variant_Record --
-----------------------
function Is_Variant_Record (T : Entity_Id) return Boolean is
begin
return Nkind (Parent (T)) = N_Full_Type_Declaration
and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
and then Present (Component_List (Type_Definition (Parent (T))))
and then Present (
Variant_Part (Component_List (Type_Definition (Parent (T)))));
end Is_Variant_Record;
-- Start of processing for Create_Constrained_Components
begin
pragma Assert (Subt /= Base_Type (Subt));
pragma Assert (Typ = Base_Type (Typ));
Set_First_Entity (Subt, Empty);
Set_Last_Entity (Subt, Empty);
-- Check whether constraint is fully static, in which case we can
-- optimize the list of components.
Discr_Val := First_Elmt (Constraints);
while Present (Discr_Val) loop
if not Is_OK_Static_Expression (Node (Discr_Val)) then
Is_Static := False;
exit;
end if;
Next_Elmt (Discr_Val);
end loop;
New_Scope (Subt);
-- Inherit the discriminants of the parent type.
Old_C := First_Discriminant (Typ);
while Present (Old_C) loop
New_C := Create_Component (Old_C);
Set_Is_Public (New_C, Is_Public (Subt));
Next_Discriminant (Old_C);
end loop;
if Is_Static
and then Is_Variant_Record (Typ)
then
Collect_Fixed_Components (Typ);
Gather_Components (
Typ,
Component_List (Type_Definition (Parent (Typ))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors);
pragma Assert (not Errors);
Create_All_Components;
-- If the subtype declaration is created for a tagged type derivation
-- with constraints, we retrieve the record definition of the parent
-- type to select the components of the proper variant.
elsif Is_Static
and then Is_Tagged_Type (Typ)
and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
and then
Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
and then Is_Variant_Record (Parent_Type)
then
Collect_Fixed_Components (Typ);
Gather_Components (
Typ,
Component_List (Type_Definition (Parent (Parent_Type))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors);
pragma Assert (not Errors);
-- If the tagged derivation has a type extension, collect all the
-- new components therein.
if Present (
Record_Extension_Part (Type_Definition (Parent (Typ))))
then
Old_C := First_Component (Typ);
while Present (Old_C) loop
if Original_Record_Component (Old_C) = Old_C
and then Chars (Old_C) /= Name_uTag
and then Chars (Old_C) /= Name_uParent
and then Chars (Old_C) /= Name_uController
then
Append_Elmt (Old_C, Comp_List);
end if;
Next_Component (Old_C);
end loop;
end if;
Create_All_Components;
else
-- If the discriminants are not static, or if this is a multi-level
-- type extension, we have to include all the components of the
-- parent type.
Old_C := First_Component (Typ);
while Present (Old_C) loop
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Component (Old_C);
end loop;
end if;
End_Scope;
end Create_Constrained_Components;
------------------------------------------
-- Decimal_Fixed_Point_Type_Declaration --
------------------------------------------
procedure Decimal_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Digs_Expr : constant Node_Id := Digits_Expression (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
Implicit_Base : Entity_Id;
Digs_Val : Uint;
Delta_Val : Ureal;
Scale_Val : Uint;
Bound_Val : Ureal;
-- Start of processing for Decimal_Fixed_Point_Type_Declaration
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Universal_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
-- Check delta is power of 10, and determine scale value from it
declare
Val : Ureal := Delta_Val;
begin
Scale_Val := Uint_0;
if Val < Ureal_1 then
while Val < Ureal_1 loop
Val := Val * Ureal_10;
Scale_Val := Scale_Val + 1;
end loop;
if Scale_Val > 18 then
Error_Msg_N ("scale exceeds maximum value of 18", Def);
Scale_Val := UI_From_Int (+18);
end if;
else
while Val > Ureal_1 loop
Val := Val / Ureal_10;
Scale_Val := Scale_Val - 1;
end loop;
if Scale_Val < -18 then
Error_Msg_N ("scale is less than minimum value of -18", Def);
Scale_Val := UI_From_Int (-18);
end if;
end if;
if Val /= Ureal_1 then
Error_Msg_N ("delta expression must be a power of 10", Def);
Delta_Val := Ureal_10 ** (-Scale_Val);
end if;
end;
-- Set delta, scale and small (small = delta for decimal type)
Set_Delta_Value (Implicit_Base, Delta_Val);
Set_Scale_Value (Implicit_Base, Scale_Val);
Set_Small_Value (Implicit_Base, Delta_Val);
-- Analyze and process digits expression
Analyze_And_Resolve (Digs_Expr, Any_Integer);
Check_Digits_Expression (Digs_Expr);
Digs_Val := Expr_Value (Digs_Expr);
if Digs_Val > 18 then
Digs_Val := UI_From_Int (+18);
Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
end if;
Set_Digits_Value (Implicit_Base, Digs_Val);
Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
-- Set range of base type from digits value for now. This will be
-- expanded to represent the true underlying base range by Freeze.
Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
-- Set size to zero for now, size will be set at freeze time. We have
-- to do this for ordinary fixed-point, because the size depends on
-- the specified small, and we might as well do the same for decimal
-- fixed-point.
Init_Size_Align (Implicit_Base);
-- Complete entity for first subtype
Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, Implicit_Base);
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Digits_Value (T, Digs_Val);
Set_Delta_Value (T, Delta_Val);
Set_Small_Value (T, Delta_Val);
Set_Scale_Value (T, Scale_Val);
Set_Is_Constrained (T);
-- If there are bounds given in the declaration use them as the
-- bounds of the first named subtype.
if Present (Real_Range_Specification (Def)) then
declare
RRS : constant Node_Id := Real_Range_Specification (Def);
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
Low_Val : Ureal;
High_Val : Ureal;
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val < (-Bound_Val) then
Error_Msg_N
("range low bound too small for digits value", Low);
Low_Val := -Bound_Val;
end if;
if High_Val > Bound_Val then
Error_Msg_N
("range high bound too large for digits value", High);
High_Val := Bound_Val;
end if;
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
end;
-- If no explicit range, use range that corresponds to given
-- digits value. This will end up as the final range for the
-- first subtype.
else
Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
end if;
end Decimal_Fixed_Point_Type_Declaration;
-----------------------
-- Derive_Subprogram --
-----------------------
procedure Derive_Subprogram
(New_Subp : in out Entity_Id;
Parent_Subp : Entity_Id;
Derived_Type : Entity_Id;
Parent_Type : Entity_Id;
Actual_Subp : Entity_Id := Empty)
is
Formal : Entity_Id;
New_Formal : Entity_Id;
Same_Subt : constant Boolean :=
Is_Scalar_Type (Parent_Type)
and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
function Is_Private_Overriding return Boolean;
-- If Subp is a private overriding of a visible operation, the in-
-- herited operation derives from the overridden op (even though
-- its body is the overriding one) and the inherited operation is
-- visible now. See sem_disp to see the details of the handling of
-- the overridden subprogram, which is removed from the list of
-- primitive operations of the type.
procedure Replace_Type (Id, New_Id : Entity_Id);
-- When the type is an anonymous access type, create a new access type
-- designating the derived type.
---------------------------
-- Is_Private_Overriding --
---------------------------
function Is_Private_Overriding return Boolean is
Prev : Entity_Id;
begin
Prev := Homonym (Parent_Subp);
-- The visible operation that is overriden is a homonym of
-- the parent subprogram. We scan the homonym chain to find
-- the one whose alias is the subprogram we are deriving.
while Present (Prev) loop
if Is_Dispatching_Operation (Parent_Subp)
and then Present (Prev)
and then Ekind (Prev) = Ekind (Parent_Subp)
and then Alias (Prev) = Parent_Subp
and then Scope (Parent_Subp) = Scope (Prev)
and then not Is_Hidden (Prev)
then
return True;
end if;
Prev := Homonym (Prev);
end loop;
return False;
end Is_Private_Overriding;
------------------
-- Replace_Type --
------------------
procedure Replace_Type (Id, New_Id : Entity_Id) is
Acc_Type : Entity_Id;
IR : Node_Id;
begin
-- When the type is an anonymous access type, create a new access
-- type designating the derived type. This itype must be elaborated
-- at the point of the derivation, not on subsequent calls that may
-- be out of the proper scope for Gigi, so we insert a reference to
-- it after the derivation.
if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
declare
Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
begin
if Ekind (Desig_Typ) = E_Record_Type_With_Private
and then Present (Full_View (Desig_Typ))
and then not Is_Private_Type (Parent_Type)
then
Desig_Typ := Full_View (Desig_Typ);
end if;
if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
Acc_Type := New_Copy (Etype (Id));
Set_Etype (Acc_Type, Acc_Type);
Set_Scope (Acc_Type, New_Subp);
-- Compute size of anonymous access type.
if Is_Array_Type (Desig_Typ)
and then not Is_Constrained (Desig_Typ)
then
Init_Size (Acc_Type, 2 * System_Address_Size);
else
Init_Size (Acc_Type, System_Address_Size);
end if;
Init_Alignment (Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Derived_Type);
Set_Etype (New_Id, Acc_Type);
Set_Scope (New_Id, New_Subp);
-- Create a reference to it.
IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
Set_Itype (IR, Acc_Type);
Insert_After (Parent (Derived_Type), IR);
else
Set_Etype (New_Id, Etype (Id));
end if;
end;
elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
or else
(Ekind (Etype (Id)) = E_Record_Type_With_Private
and then Present (Full_View (Etype (Id)))
and then Base_Type (Full_View (Etype (Id))) =
Base_Type (Parent_Type))
then
-- Constraint checks on formals are generated during expansion,
-- based on the signature of the original subprogram. The bounds
-- of the derived type are not relevant, and thus we can use
-- the base type for the formals. However, the return type may be
-- used in a context that requires that the proper static bounds
-- be used (a case statement, for example) and for those cases
-- we must use the derived type (first subtype), not its base.
if Etype (Id) = Parent_Type
and then Same_Subt
then
Set_Etype (New_Id, Derived_Type);
else
Set_Etype (New_Id, Base_Type (Derived_Type));
end if;
else
Set_Etype (New_Id, Etype (Id));
end if;
end Replace_Type;
-- Start of processing for Derive_Subprogram
begin
New_Subp :=
New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
Set_Ekind (New_Subp, Ekind (Parent_Subp));
-- Check whether the inherited subprogram is a private operation that
-- should be inherited but not yet made visible. Such subprograms can
-- become visible at a later point (e.g., the private part of a public
-- child unit) via Declare_Inherited_Private_Subprograms. If the
-- following predicate is true, then this is not such a private
-- operation and the subprogram simply inherits the name of the parent
-- subprogram. Note the special check for the names of controlled
-- operations, which are currently exempted from being inherited with
-- a hidden name because they must be findable for generation of
-- implicit run-time calls.
if not Is_Hidden (Parent_Subp)
or else Is_Internal (Parent_Subp)
or else Is_Private_Overriding
or else Is_Internal_Name (Chars (Parent_Subp))
or else Chars (Parent_Subp) = Name_Initialize
or else Chars (Parent_Subp) = Name_Adjust
or else Chars (Parent_Subp) = Name_Finalize
then
Set_Chars (New_Subp, Chars (Parent_Subp));
-- If parent is hidden, this can be a regular derivation if the
-- parent is immediately visible in a non-instantiating context,
-- or if we are in the private part of an instance. This test
-- should still be refined ???
-- The test for In_Instance_Not_Visible avoids inheriting the
-- derived operation as a non-visible operation in cases where
-- the parent subprogram might not be visible now, but was
-- visible within the original generic, so it would be wrong
-- to make the inherited subprogram non-visible now. (Not
-- clear if this test is fully correct; are there any cases
-- where we should declare the inherited operation as not
-- visible to avoid it being overridden, e.g., when the
-- parent type is a generic actual with private primitives ???)
-- (they should be treated the same as other private inherited
-- subprograms, but it's not clear how to do this cleanly). ???
elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
and then Is_Immediately_Visible (Parent_Subp)
and then not In_Instance)
or else In_Instance_Not_Visible
then
Set_Chars (New_Subp, Chars (Parent_Subp));
-- The type is inheriting a private operation, so enter
-- it with a special name so it can't be overridden.
else
Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
end if;
Set_Parent (New_Subp, Parent (Derived_Type));
Replace_Type (Parent_Subp, New_Subp);
Conditional_Delay (New_Subp, Parent_Subp);
Formal := First_Formal (Parent_Subp);
while Present (Formal) loop
New_Formal := New_Copy (Formal);
-- Normally we do not go copying parents, but in the case of
-- formals, we need to link up to the declaration (which is
-- the parameter specification), and it is fine to link up to
-- the original formal's parameter specification in this case.
Set_Parent (New_Formal, Parent (Formal));
Append_Entity (New_Formal, New_Subp);
Replace_Type (Formal, New_Formal);
Next_Formal (Formal);
end loop;
-- If this derivation corresponds to a tagged generic actual, then
-- primitive operations rename those of the actual. Otherwise the
-- primitive operations rename those of the parent type.
if No (Actual_Subp) then
Set_Alias (New_Subp, Parent_Subp);
Set_Is_Intrinsic_Subprogram (New_Subp,
Is_Intrinsic_Subprogram (Parent_Subp));
else
Set_Alias (New_Subp, Actual_Subp);
end if;
-- Derived subprograms of a tagged type must inherit the convention
-- of the parent subprogram (a requirement of AI-117). Derived
-- subprograms of untagged types simply get convention Ada by default.
if Is_Tagged_Type (Derived_Type) then
Set_Convention (New_Subp, Convention (Parent_Subp));
end if;
Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
if Ekind (Parent_Subp) = E_Procedure then
Set_Is_Valued_Procedure
(New_Subp, Is_Valued_Procedure (Parent_Subp));
end if;
New_Overloaded_Entity (New_Subp, Derived_Type);
-- Check for case of a derived subprogram for the instantiation
-- of a formal derived tagged type, so mark the subprogram as
-- dispatching and inherit the dispatching attributes of the
-- parent subprogram. The derived subprogram is effectively a
-- renaming of the actual subprogram, so it needs to have the
-- same attributes as the actual.
if Present (Actual_Subp)
and then Is_Dispatching_Operation (Parent_Subp)
then
Set_Is_Dispatching_Operation (New_Subp);
if Present (DTC_Entity (Parent_Subp)) then
Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
end if;
end if;
-- Indicate that a derived subprogram does not require a body
-- and that it does not require processing of default expressions.
Set_Has_Completion (New_Subp);
Set_Default_Expressions_Processed (New_Subp);
-- A derived function with a controlling result is abstract.
-- If the Derived_Type is a nonabstract formal generic derived
-- type, then inherited operations are not abstract: check is
-- done at instantiation time. If the derivation is for a generic
-- actual, the function is not abstract unless the actual is.
if Is_Generic_Type (Derived_Type)
and then not Is_Abstract (Derived_Type)
then
null;
elsif Is_Abstract (Alias (New_Subp))
or else (Is_Tagged_Type (Derived_Type)
and then Etype (New_Subp) = Derived_Type
and then No (Actual_Subp))
then
Set_Is_Abstract (New_Subp);
end if;
if Ekind (New_Subp) = E_Function then
Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
end if;
end Derive_Subprogram;
------------------------
-- Derive_Subprograms --
------------------------
procedure Derive_Subprograms
(Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Generic_Actual : Entity_Id := Empty)
is
Op_List : Elist_Id := Collect_Primitive_Operations (Parent_Type);
Act_List : Elist_Id;
Act_Elmt : Elmt_Id;
Elmt : Elmt_Id;
Subp : Entity_Id;
New_Subp : Entity_Id := Empty;
Parent_Base : Entity_Id;
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Has_Discriminants (Parent_Type)
and then Present (Full_View (Parent_Type))
then
Parent_Base := Full_View (Parent_Type);
else
Parent_Base := Parent_Type;
end if;
Elmt := First_Elmt (Op_List);
if Present (Generic_Actual) then
Act_List := Collect_Primitive_Operations (Generic_Actual);
Act_Elmt := First_Elmt (Act_List);
else
Act_Elmt := No_Elmt;
end if;
-- Literals are derived earlier in the process of building the
-- derived type, and are skipped here.
while Present (Elmt) loop
Subp := Node (Elmt);
if Ekind (Subp) /= E_Enumeration_Literal then
if No (Generic_Actual) then
Derive_Subprogram
(New_Subp, Subp, Derived_Type, Parent_Base);
else
Derive_Subprogram (New_Subp, Subp,
Derived_Type, Parent_Base, Node (Act_Elmt));
Next_Elmt (Act_Elmt);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end Derive_Subprograms;
--------------------------------
-- Derived_Standard_Character --
--------------------------------
procedure Derived_Standard_Character
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : constant Entity_Id :=
Create_Itype
(E_Enumeration_Type, N, Derived_Type, 'B');
Lo : Node_Id;
Hi : Node_Id;
T : Entity_Id;
begin
T := Process_Subtype (Indic, N);
Set_Etype (Implicit_Base, Parent_Base);
Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
Set_Is_Character_Type (Implicit_Base, True);
Set_Has_Delayed_Freeze (Implicit_Base);
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
Conditional_Delay (Derived_Type, Parent_Type);
Set_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Set_Size_Info (Derived_Type, Parent_Type);
if Unknown_RM_Size (Derived_Type) then
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
end if;
Set_Is_Character_Type (Derived_Type, True);
if Nkind (Indic) /= N_Subtype_Indication then
Set_Scalar_Range (Derived_Type, Scalar_Range (Implicit_Base));
end if;
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
-- Because the implicit base is used in the conversion of the bounds,
-- we have to freeze it now. This is similar to what is done for
-- numeric types, and it equally suspicious, but otherwise a non-
-- static bound will have a reference to an unfrozen type, which is
-- rejected by Gigi (???).
Freeze_Before (N, Implicit_Base);
end Derived_Standard_Character;
------------------------------
-- Derived_Type_Declaration --
------------------------------
procedure Derived_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Is_Completion : Boolean)
is
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Extension : constant Node_Id := Record_Extension_Part (Def);
Parent_Type : Entity_Id;
Parent_Scope : Entity_Id;
Taggd : Boolean;
begin
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
if Parent_Type = Any_Type
or else Etype (Parent_Type) = Any_Type
or else (Is_Class_Wide_Type (Parent_Type)
and then Etype (Parent_Type) = T)
then
-- If Parent_Type is undefined or illegal, make new type into
-- a subtype of Any_Type, and set a few attributes to prevent
-- cascaded errors. If this is a self-definition, emit error now.
if T = Parent_Type
or else T = Etype (Parent_Type)
then
Error_Msg_N ("type cannot be used in its own definition", Indic);
end if;
Set_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
Set_Scalar_Range (T, Scalar_Range (Any_Type));
if Is_Tagged_Type (T) then
Set_Primitive_Operations (T, New_Elmt_List);
end if;
return;
elsif Is_Unchecked_Union (Parent_Type) then
Error_Msg_N ("cannot derive from Unchecked_Union type", N);
end if;
-- Only composite types other than array types are allowed to have
-- discriminants.
if Present (Discriminant_Specifications (N))
and then (Is_Elementary_Type (Parent_Type)
or else Is_Array_Type (Parent_Type))
and then not Error_Posted (N)
then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier (First (Discriminant_Specifications (N))));
Set_Has_Discriminants (T, False);
end if;
-- In Ada 83, a derived type defined in a package specification cannot
-- be used for further derivation until the end of its visible part.
-- Note that derivation in the private part of the package is allowed.
if Ada_83
and then Is_Derived_Type (Parent_Type)
and then In_Visible_Part (Scope (Parent_Type))
then
if Ada_83 and then Comes_From_Source (Indic) then
Error_Msg_N
("(Ada 83): premature use of type for derivation", Indic);
end if;
end if;
-- Check for early use of incomplete or private type
if Ekind (Parent_Type) = E_Void
or else Ekind (Parent_Type) = E_Incomplete_Type
then
Error_Msg_N ("premature derivation of incomplete type", Indic);
return;
elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
and then not Is_Generic_Type (Parent_Type)
and then not Is_Generic_Type (Root_Type (Parent_Type))
and then not Is_Generic_Actual_Type (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
-- The ancestor type of a formal type can be incomplete, in which
-- case only the operations of the partial view are available in
-- the generic. Subsequent checks may be required when the full
-- view is analyzed, to verify that derivation from a tagged type
-- has an extension.
if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
null;
elsif No (Underlying_Type (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
Error_Msg_N
("premature derivation of derived or private type", Indic);
-- Flag the type itself as being in error, this prevents some
-- nasty problems with people looking at the malformed type.
Set_Error_Posted (T);
-- Check that within the immediate scope of an untagged partial
-- view it's illegal to derive from the partial view if the
-- full view is tagged. (7.3(7))
-- We verify that the Parent_Type is a partial view by checking
-- that it is not a Full_Type_Declaration (i.e. a private type or
-- private extension declaration), to distinguish a partial view
-- from a derivation from a private type which also appears as
-- E_Private_Type.
elsif Present (Full_View (Parent_Type))
and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
and then not Is_Tagged_Type (Parent_Type)
and then Is_Tagged_Type (Full_View (Parent_Type))
then
Parent_Scope := Scope (T);
while Present (Parent_Scope)
and then Parent_Scope /= Standard_Standard
loop
if Parent_Scope = Scope (Parent_Type) then
Error_Msg_N
("premature derivation from type with tagged full view",
Indic);
end if;
Parent_Scope := Scope (Parent_Scope);
end loop;
end if;
end if;
-- Check that form of derivation is appropriate
Taggd := Is_Tagged_Type (Parent_Type);
-- Perhaps the parent type should be changed to the class-wide type's
-- specific type in this case to prevent cascading errors ???
if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N ("parent type must not be a class-wide type", Indic);
return;
end if;
if Present (Extension) and then not Taggd then
Error_Msg_N
("type derived from untagged type cannot have extension", Indic);
elsif No (Extension) and then Taggd then
-- If this is within a private part (or body) of a generic
-- instantiation then the derivation is allowed (the parent
-- type can only appear tagged in this case if it's a generic
-- actual type, since it would otherwise have been rejected
-- in the analysis of the generic template).
if not Is_Generic_Actual_Type (Parent_Type)
or else In_Visible_Part (Scope (Parent_Type))
then
Error_Msg_N
("type derived from tagged type must have extension", Indic);
end if;
end if;
Build_Derived_Type (N, Parent_Type, T, Is_Completion);
end Derived_Type_Declaration;
----------------------------------
-- Enumeration_Type_Declaration --
----------------------------------
procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Ev : Uint;
L : Node_Id;
R_Node : Node_Id;
B_Node : Node_Id;
begin
-- Create identifier node representing lower bound
B_Node := New_Node (N_Identifier, Sloc (Def));
L := First (Literals (Def));
Set_Chars (B_Node, Chars (L));
Set_Entity (B_Node, L);
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
R_Node := New_Node (N_Range, Sloc (Def));
Set_Low_Bound (R_Node, B_Node);
Set_Ekind (T, E_Enumeration_Type);
Set_First_Literal (T, L);
Set_Etype (T, T);
Set_Is_Constrained (T);
Ev := Uint_0;
-- Loop through literals of enumeration type setting pos and rep values
-- except that if the Ekind is already set, then it means that the
-- literal was already constructed (case of a derived type declaration
-- and we should not disturb the Pos and Rep values.
while Present (L) loop
if Ekind (L) /= E_Enumeration_Literal then
Set_Ekind (L, E_Enumeration_Literal);
Set_Enumeration_Pos (L, Ev);
Set_Enumeration_Rep (L, Ev);
Set_Is_Known_Valid (L, True);
end if;
Set_Etype (L, T);
New_Overloaded_Entity (L);
Generate_Definition (L);
Set_Convention (L, Convention_Intrinsic);
if Nkind (L) = N_Defining_Character_Literal then
Set_Is_Character_Type (T, True);
end if;
Ev := Ev + 1;
Next (L);
end loop;
-- Now create a node representing upper bound
B_Node := New_Node (N_Identifier, Sloc (Def));
Set_Chars (B_Node, Chars (Last (Literals (Def))));
Set_Entity (B_Node, Last (Literals (Def)));
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
Set_High_Bound (R_Node, B_Node);
Set_Scalar_Range (T, R_Node);
Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
Set_Enum_Esize (T);
-- Set Discard_Names if configuration pragma setg, or if there is
-- a parameterless pragma in the current declarative region
if Global_Discard_Names
or else Discard_Names (Scope (T))
then
Set_Discard_Names (T);
end if;
end Enumeration_Type_Declaration;
--------------------------
-- Expand_Others_Choice --
--------------------------
procedure Expand_Others_Choice
(Case_Table : Choice_Table_Type;
Others_Choice : Node_Id;
Choice_Type : Entity_Id)
is
Choice : Node_Id;
Choice_List : List_Id := New_List;
Exp_Lo : Node_Id;
Exp_Hi : Node_Id;
Hi : Uint;
Lo : Uint;
Loc : Source_Ptr := Sloc (Others_Choice);
Previous_Hi : Uint;
function Build_Choice (Value1, Value2 : Uint) return Node_Id;
-- Builds a node representing the missing choices given by the
-- Value1 and Value2. A N_Range node is built if there is more than
-- one literal value missing. Otherwise a single N_Integer_Literal,
-- N_Identifier or N_Character_Literal is built depending on what
-- Choice_Type is.
function Lit_Of (Value : Uint) return Node_Id;
-- Returns the Node_Id for the enumeration literal corresponding to the
-- position given by Value within the enumeration type Choice_Type.
------------------
-- Build_Choice --
------------------
function Build_Choice (Value1, Value2 : Uint) return Node_Id is
Lit_Node : Node_Id;
Lo, Hi : Node_Id;
begin
-- If there is only one choice value missing between Value1 and
-- Value2, build an integer or enumeration literal to represent it.
if (Value2 - Value1) = 0 then
if Is_Integer_Type (Choice_Type) then
Lit_Node := Make_Integer_Literal (Loc, Value1);
Set_Etype (Lit_Node, Choice_Type);
else
Lit_Node := Lit_Of (Value1);
end if;
-- Otherwise is more that one choice value that is missing between
-- Value1 and Value2, therefore build a N_Range node of either
-- integer or enumeration literals.
else
if Is_Integer_Type (Choice_Type) then
Lo := Make_Integer_Literal (Loc, Value1);
Set_Etype (Lo, Choice_Type);
Hi := Make_Integer_Literal (Loc, Value2);
Set_Etype (Hi, Choice_Type);
Lit_Node :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
else
Lit_Node :=
Make_Range (Loc,
Low_Bound => Lit_Of (Value1),
High_Bound => Lit_Of (Value2));
end if;
end if;
return Lit_Node;
end Build_Choice;
------------
-- Lit_Of --
------------
function Lit_Of (Value : Uint) return Node_Id is
Lit : Entity_Id;
begin
-- In the case where the literal is of type Character, there needs
-- to be some special handling since there is no explicit chain
-- of literals to search. Instead, a N_Character_Literal node
-- is created with the appropriate Char_Code and Chars fields.
if Root_Type (Choice_Type) = Standard_Character then
Set_Character_Literal_Name (Char_Code (UI_To_Int (Value)));
Lit := New_Node (N_Character_Literal, Loc);
Set_Chars (Lit, Name_Find);
Set_Char_Literal_Value (Lit, Char_Code (UI_To_Int (Value)));
Set_Etype (Lit, Choice_Type);
Set_Is_Static_Expression (Lit, True);
return Lit;
-- Otherwise, iterate through the literals list of Choice_Type
-- "Value" number of times until the desired literal is reached
-- and then return an occurrence of it.
else
Lit := First_Literal (Choice_Type);
for J in 1 .. UI_To_Int (Value) loop
Next_Literal (Lit);
end loop;
return New_Occurrence_Of (Lit, Loc);
end if;
end Lit_Of;
-- Start of processing for Expand_Others_Choice
begin
if Case_Table'Length = 0 then
-- Pathological case: only an others case is present.
-- The others case covers the full range of the type.
if Is_Static_Subtype (Choice_Type) then
Choice := New_Occurrence_Of (Choice_Type, Loc);
else
Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc);
end if;
Set_Others_Discrete_Choices (Others_Choice, New_List (Choice));
return;
end if;
-- Establish the bound values for the variant depending upon whether
-- the type of the discriminant name is static or not.
if Is_OK_Static_Subtype (Choice_Type) then
Exp_Lo := Type_Low_Bound (Choice_Type);
Exp_Hi := Type_High_Bound (Choice_Type);
else
Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type));
Exp_Hi := Type_High_Bound (Base_Type (Choice_Type));
end if;
Lo := Expr_Value (Case_Table (Case_Table'First).Lo);
Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
Previous_Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
-- Build the node for any missing choices that are smaller than any
-- explicit choices given in the variant.
if Expr_Value (Exp_Lo) < Lo then
Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List);
end if;
-- Build the nodes representing any missing choices that lie between
-- the explicit ones given in the variant.
for J in Case_Table'First + 1 .. Case_Table'Last loop
Lo := Expr_Value (Case_Table (J).Lo);
Hi := Expr_Value (Case_Table (J).Hi);
if Lo /= (Previous_Hi + 1) then
Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1));
end if;
Previous_Hi := Hi;
end loop;
-- Build the node for any missing choices that are greater than any
-- explicit choices given in the variant.
if Expr_Value (Exp_Hi) > Hi then
Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List);
end if;
Set_Others_Discrete_Choices (Others_Choice, Choice_List);
end Expand_Others_Choice;
---------------------------------
-- Expand_To_Girder_Constraint --
---------------------------------
function Expand_To_Girder_Constraint
(Typ : Entity_Id;
Constraint : Elist_Id)
return Elist_Id
is
Explicitly_Discriminated_Type : Entity_Id;
Expansion : Elist_Id;
Discriminant : Entity_Id;
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
-- Find the nearest type that actually specifies discriminants.
---------------------------------
-- Type_With_Explicit_Discrims --
---------------------------------
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
Typ : constant E := Base_Type (Id);
begin
if Ekind (Typ) in Incomplete_Or_Private_Kind then
if Present (Full_View (Typ)) then
return Type_With_Explicit_Discrims (Full_View (Typ));
end if;
else
if Has_Discriminants (Typ) then
return Typ;
end if;
end if;
if Etype (Typ) = Typ then
return Empty;
elsif Has_Discriminants (Typ) then
return Typ;
else
return Type_With_Explicit_Discrims (Etype (Typ));
end if;
end Type_With_Explicit_Discrims;
-- Start of processing for Expand_To_Girder_Constraint
begin
if No (Constraint)
or else Is_Empty_Elmt_List (Constraint)
then
return No_Elist;
end if;
Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
if No (Explicitly_Discriminated_Type) then
return No_Elist;
end if;
Expansion := New_Elmt_List;
Discriminant :=
First_Girder_Discriminant (Explicitly_Discriminated_Type);
while Present (Discriminant) loop
Append_Elmt (
Get_Discriminant_Value (
Discriminant, Explicitly_Discriminated_Type, Constraint),
Expansion);
Next_Girder_Discriminant (Discriminant);
end loop;
return Expansion;
end Expand_To_Girder_Constraint;
--------------------
-- Find_Type_Name --
--------------------
function Find_Type_Name (N : Node_Id) return Entity_Id is
Id : constant Entity_Id := Defining_Identifier (N);
Prev : Entity_Id;
New_Id : Entity_Id;
Prev_Par : Node_Id;
begin
-- Find incomplete declaration, if some was given.
Prev := Current_Entity_In_Scope (Id);
if Present (Prev) then
-- Previous declaration exists. Error if not incomplete/private case
-- except if previous declaration is implicit, etc. Enter_Name will
-- emit error if appropriate.
Prev_Par := Parent (Prev);
if not Is_Incomplete_Or_Private_Type (Prev) then
Enter_Name (Id);
New_Id := Id;
elsif Nkind (N) /= N_Full_Type_Declaration
and then Nkind (N) /= N_Task_Type_Declaration
and then Nkind (N) /= N_Protected_Type_Declaration
then
-- Completion must be a full type declarations (RM 7.3(4))
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_NE ("invalid completion of }", Id, Prev);
-- Set scope of Id to avoid cascaded errors. Entity is never
-- examined again, except when saving globals in generics.
Set_Scope (Id, Current_Scope);
New_Id := Id;
-- Case of full declaration of incomplete type
elsif Ekind (Prev) = E_Incomplete_Type then
-- Indicate that the incomplete declaration has a matching
-- full declaration. The defining occurrence of the incomplete
-- declaration remains the visible one, and the procedure
-- Get_Full_View dereferences it whenever the type is used.
if Present (Full_View (Prev)) then
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
end if;
Set_Full_View (Prev, Id);
Append_Entity (Id, Current_Scope);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
New_Id := Prev;
-- Case of full declaration of private type
else
if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
if Etype (Prev) /= Prev then
-- Prev is a private subtype or a derived type, and needs
-- no completion.
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
New_Id := Id;
elsif Ekind (Prev) = E_Private_Type
and then
(Nkind (N) = N_Task_Type_Declaration
or else Nkind (N) = N_Protected_Type_Declaration)
then
Error_Msg_N
("completion of nonlimited type cannot be limited", N);
end if;
elsif Nkind (N) /= N_Full_Type_Declaration
or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
then
Error_Msg_N ("full view of private extension must be"
& " an extension", N);
elsif not (Abstract_Present (Parent (Prev)))
and then Abstract_Present (Type_Definition (N))
then
Error_Msg_N ("full view of non-abstract extension cannot"
& " be abstract", N);
end if;
if not In_Private_Part (Current_Scope) then
Error_Msg_N
("declaration of full view must appear in private part", N);
end if;
Copy_And_Swap (Prev, Id);
Set_Full_View (Id, Prev);
Set_Has_Private_Declaration (Prev);
Set_Has_Private_Declaration (Id);
New_Id := Prev;
end if;
-- Verify that full declaration conforms to incomplete one
if Is_Incomplete_Or_Private_Type (Prev)
and then Present (Discriminant_Specifications (Prev_Par))
then
if Present (Discriminant_Specifications (N)) then
if Ekind (Prev) = E_Incomplete_Type then
Check_Discriminant_Conformance (N, Prev, Prev);
else
Check_Discriminant_Conformance (N, Prev, Id);
end if;
else
Error_Msg_N
("missing discriminants in full type declaration", N);
-- To avoid cascaded errors on subsequent use, share the
-- discriminants of the partial view.
Set_Discriminant_Specifications (N,
Discriminant_Specifications (Prev_Par));
end if;
end if;
-- A prior untagged private type can have an associated
-- class-wide type due to use of the class attribute,
-- and in this case also the full type is required to
-- be tagged.
if Is_Type (Prev)
and then (Is_Tagged_Type (Prev)
or else Present (Class_Wide_Type (Prev)))
then
-- The full declaration is either a tagged record or an
-- extension otherwise this is an error
if Nkind (Type_Definition (N)) = N_Record_Definition then
if not Tagged_Present (Type_Definition (N)) then
Error_Msg_NE
("full declaration of } must be tagged", Prev, Id);
Set_Is_Tagged_Type (Id);
Set_Primitive_Operations (Id, New_Elmt_List);
end if;
elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
if No (Record_Extension_Part (Type_Definition (N))) then
Error_Msg_NE (
"full declaration of } must be a record extension",
Prev, Id);
Set_Is_Tagged_Type (Id);
Set_Primitive_Operations (Id, New_Elmt_List);
end if;
else
Error_Msg_NE
("full declaration of } must be a tagged type", Prev, Id);
end if;
end if;
return New_Id;
else
-- New type declaration
Enter_Name (Id);
return Id;
end if;
end Find_Type_Name;
-------------------------
-- Find_Type_Of_Object --
-------------------------
function Find_Type_Of_Object
(Obj_Def : Node_Id;
Related_Nod : Node_Id)
return Entity_Id
is
Def_Kind : constant Node_Kind := Nkind (Obj_Def);
P : constant Node_Id := Parent (Obj_Def);
T : Entity_Id;
Nam : Name_Id;
begin
-- Case of an anonymous array subtype
if Def_Kind = N_Constrained_Array_Definition
or else Def_Kind = N_Unconstrained_Array_Definition
then
T := Empty;
Array_Type_Declaration (T, Obj_Def);
-- Create an explicit subtype whenever possible.
elsif Nkind (P) /= N_Component_Declaration
and then Def_Kind = N_Subtype_Indication
then
-- Base name of subtype on object name, which will be unique in
-- the current scope.
-- If this is a duplicate declaration, return base type, to avoid
-- generating duplicate anonymous types.
if Error_Posted (P) then
Analyze (Subtype_Mark (Obj_Def));
return Entity (Subtype_Mark (Obj_Def));
end if;
Nam :=
New_External_Name
(Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
T := Make_Defining_Identifier (Sloc (P), Nam);
Insert_Action (Obj_Def,
Make_Subtype_Declaration (Sloc (P),
Defining_Identifier => T,
Subtype_Indication => Relocate_Node (Obj_Def)));
-- This subtype may need freezing and it will not be done
-- automatically if the object declaration is not in a
-- declarative part. Since this is an object declaration, the
-- type cannot always be frozen here. Deferred constants do not
-- freeze their type (which often enough will be private).
if Nkind (P) = N_Object_Declaration
and then Constant_Present (P)
and then No (Expression (P))
then
null;
else
Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
end if;
else
T := Process_Subtype (Obj_Def, Related_Nod);
end if;
return T;
end Find_Type_Of_Object;
--------------------------------
-- Find_Type_Of_Subtype_Indic --
--------------------------------
function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
Typ : Entity_Id;
begin
-- Case of subtype mark with a constraint
if Nkind (S) = N_Subtype_Indication then
Find_Type (Subtype_Mark (S));
Typ := Entity (Subtype_Mark (S));
if not
Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
then
Error_Msg_N
("incorrect constraint for this kind of type", Constraint (S));
Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
end if;
-- Otherwise we have a subtype mark without a constraint
elsif Error_Posted (S) then
Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
return Any_Type;
else
Find_Type (S);
Typ := Entity (S);
end if;
if Typ = Standard_Wide_Character
or else Typ = Standard_Wide_String
then
Check_Restriction (No_Wide_Characters, S);
end if;
return Typ;
end Find_Type_Of_Subtype_Indic;
-------------------------------------
-- Floating_Point_Type_Declaration --
-------------------------------------
procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Digs : constant Node_Id := Digits_Expression (Def);
Digs_Val : Uint;
Base_Typ : Entity_Id;
Implicit_Base : Entity_Id;
Bound : Node_Id;
function Can_Derive_From (E : Entity_Id) return Boolean;
-- Find if given digits value allows derivation from specified type
function Can_Derive_From (E : Entity_Id) return Boolean is
Spec : constant Entity_Id := Real_Range_Specification (Def);
begin
if Digs_Val > Digits_Value (E) then
return False;
end if;
if Present (Spec) then
if Expr_Value_R (Type_Low_Bound (E)) >
Expr_Value_R (Low_Bound (Spec))
then
return False;
end if;
if Expr_Value_R (Type_High_Bound (E)) <
Expr_Value_R (High_Bound (Spec))
then
return False;
end if;
end if;
return True;
end Can_Derive_From;
-- Start of processing for Floating_Point_Type_Declaration
begin
Check_Restriction (No_Floating_Point, Def);
-- Create an implicit base type
Implicit_Base :=
Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
-- Analyze and verify digits value
Analyze_And_Resolve (Digs, Any_Integer);
Check_Digits_Expression (Digs);
Digs_Val := Expr_Value (Digs);
-- Process possible range spec and find correct type to derive from
Process_Real_Range_Specification (Def);
if Can_Derive_From (Standard_Short_Float) then
Base_Typ := Standard_Short_Float;
elsif Can_Derive_From (Standard_Float) then
Base_Typ := Standard_Float;
elsif Can_Derive_From (Standard_Long_Float) then
Base_Typ := Standard_Long_Float;
elsif Can_Derive_From (Standard_Long_Long_Float) then
Base_Typ := Standard_Long_Long_Float;
-- If we can't derive from any existing type, use long long float
-- and give appropriate message explaining the problem.
else
Base_Typ := Standard_Long_Long_Float;
if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
Error_Msg_N ("digits value out of range, maximum is ^", Digs);
else
Error_Msg_N
("range too large for any predefined type",
Real_Range_Specification (Def));
end if;
end if;
-- If there are bounds given in the declaration use them as the bounds
-- of the type, otherwise use the bounds of the predefined base type
-- that was chosen based on the Digits value.
if Present (Real_Range_Specification (Def)) then
Set_Scalar_Range (T, Real_Range_Specification (Def));
Set_Is_Constrained (T);
-- The bounds of this range must be converted to machine numbers
-- in accordance with RM 4.9(38).
Bound := Type_Low_Bound (T);
if Nkind (Bound) = N_Real_Literal then
Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
Set_Is_Machine_Number (Bound);
end if;
Bound := Type_High_Bound (T);
if Nkind (Bound) = N_Real_Literal then
Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
Set_Is_Machine_Number (Bound);
end if;
else
Set_Scalar_Range (T, Scalar_Range (Base_Typ));
end if;
-- Complete definition of implicit base and declared first subtype
Set_Etype (Implicit_Base, Base_Typ);
Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
Set_Size_Info (Implicit_Base, (Base_Typ));
Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
Set_Ekind (T, E_Floating_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, (Implicit_Base));
Set_RM_Size (T, RM_Size (Implicit_Base));
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Digits_Value (T, Digs_Val);
end Floating_Point_Type_Declaration;
----------------------------
-- Get_Discriminant_Value --
----------------------------
-- This is the situation...
-- There is a non-derived type
-- type T0 (Dx, Dy, Dz...)
-- There are zero or more levels of derivation, with each
-- derivation either purely inheriting the discriminants, or
-- defining its own.
-- type Ti is new Ti-1
-- or
-- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
-- or
-- subtype Ti is ...
-- The subtype issue is avoided by the use of
-- Original_Record_Component, and the fact that derived subtypes
-- also derive the constraits.
-- This chain leads back from
-- Typ_For_Constraint
-- Typ_For_Constraint has discriminants, and the value for each
-- discriminant is given by its corresponding Elmt of Constraints.
-- Discriminant is some discriminant in this hierarchy.
-- We need to return its value.
-- We do this by recursively searching each level, and looking for
-- Discriminant. Once we get to the bottom, we start backing up
-- returning the value for it which may in turn be a discriminant
-- further up, so on the backup we continue the substitution.
function Get_Discriminant_Value
(Discriminant : Entity_Id;
Typ_For_Constraint : Entity_Id;
Constraint : Elist_Id)
return Node_Id
is
function Recurse
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Girder_Discrim_Values : Boolean)
return Node_Or_Entity_Id;
-- This is the routine that performs the recursive search of levels
-- as described above.
function Recurse
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Girder_Discrim_Values : Boolean)
return Node_Or_Entity_Id
is
Assoc : Elmt_Id;
Disc : Entity_Id;
Result : Node_Or_Entity_Id;
Result_Entity : Node_Id;
begin
-- If inappropriate type, return Error, this happens only in
-- cascaded error situations, and we want to avoid a blow up.
if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
return Error;
end if;
-- Look deeper if possible. Use Girder_Constraints only for
-- untagged types. For tagged types use the given constraint.
-- This asymmetry needs explanation???
if not Girder_Discrim_Values
and then Present (Girder_Constraint (Ti))
and then not Is_Tagged_Type (Ti)
then
Result := Recurse (Ti, Girder_Constraint (Ti), True);
else
declare
Td : Entity_Id := Etype (Ti);
begin
if Td = Ti then
Result := Discriminant;
else
if Present (Girder_Constraint (Ti)) then
Result :=
Recurse (Td, Girder_Constraint (Ti), True);
else
Result :=
Recurse (Td, Discrim_Values, Girder_Discrim_Values);
end if;
end if;
end;
end if;
-- Extra underlying places to search, if not found above. For
-- concurrent types, the relevant discriminant appears in the
-- corresponding record. For a type derived from a private type
-- without discriminant, the full view inherits the discriminants
-- of the full view of the parent.
if Result = Discriminant then
if Is_Concurrent_Type (Ti)
and then Present (Corresponding_Record_Type (Ti))
then
Result :=
Recurse (
Corresponding_Record_Type (Ti),
Discrim_Values,
Girder_Discrim_Values);
elsif Is_Private_Type (Ti)
and then not Has_Discriminants (Ti)
and then Present (Full_View (Ti))
and then Etype (Full_View (Ti)) /= Ti
then
Result :=
Recurse (
Full_View (Ti),
Discrim_Values,
Girder_Discrim_Values);
end if;
end if;
-- If Result is not a (reference to a) discriminant,
-- return it, otherwise set Result_Entity to the discriminant.
if Nkind (Result) = N_Defining_Identifier then
pragma Assert (Result = Discriminant);
Result_Entity := Result;
else
if not Denotes_Discriminant (Result) then
return Result;
end if;
Result_Entity := Entity (Result);
end if;
-- See if this level of derivation actually has discriminants
-- because tagged derivations can add them, hence the lower
-- levels need not have any.
if not Has_Discriminants (Ti) then
return Result;
end if;
-- Scan Ti's discriminants for Result_Entity,
-- and return its corresponding value, if any.
Result_Entity := Original_Record_Component (Result_Entity);
Assoc := First_Elmt (Discrim_Values);
if Girder_Discrim_Values then
Disc := First_Girder_Discriminant (Ti);
else
Disc := First_Discriminant (Ti);
end if;
while Present (Disc) loop
pragma Assert (Present (Assoc));
if Original_Record_Component (Disc) = Result_Entity then
return Node (Assoc);
end if;
Next_Elmt (Assoc);
if Girder_Discrim_Values then
Next_Girder_Discriminant (Disc);
else
Next_Discriminant (Disc);
end if;
end loop;
-- Could not find it
--
return Result;
end Recurse;
Result : Node_Or_Entity_Id;
-- Start of processing for Get_Discriminant_Value
begin
-- ??? this routine is a gigantic mess and will be deleted.
-- for the time being just test for the trivial case before calling
-- recurse.
if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
declare
D : Entity_Id := First_Discriminant (Typ_For_Constraint);
E : Elmt_Id := First_Elmt (Constraint);
begin
while Present (D) loop
if Chars (D) = Chars (Discriminant) then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
Result := Recurse (Typ_For_Constraint, Constraint, False);
-- ??? hack to disappear when this routine is gone
if Nkind (Result) = N_Defining_Identifier then
declare
D : Entity_Id := First_Discriminant (Typ_For_Constraint);
E : Elmt_Id := First_Elmt (Constraint);
begin
while Present (D) loop
if Corresponding_Discriminant (D) = Discriminant then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
pragma Assert (Nkind (Result) /= N_Defining_Identifier);
return Result;
end Get_Discriminant_Value;
--------------------------
-- Has_Range_Constraint --
--------------------------
function Has_Range_Constraint (N : Node_Id) return Boolean is
C : constant Node_Id := Constraint (N);
begin
if Nkind (C) = N_Range_Constraint then
return True;
elsif Nkind (C) = N_Digits_Constraint then
return
Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
or else
Present (Range_Constraint (C));
elsif Nkind (C) = N_Delta_Constraint then
return Present (Range_Constraint (C));
else
return False;
end if;
end Has_Range_Constraint;
------------------------
-- Inherit_Components --
------------------------
function Inherit_Components
(N : Node_Id;
Parent_Base : Entity_Id;
Derived_Base : Entity_Id;
Is_Tagged : Boolean;
Inherit_Discr : Boolean;
Discs : Elist_Id)
return Elist_Id
is
Assoc_List : Elist_Id := New_Elmt_List;
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Girder_Discrim : Boolean := False);
-- Inherits component Old_C from Parent_Base to the Derived_Base.
-- If Plain_Discrim is True, Old_C is a discriminant.
-- If Girder_Discrim is True, Old_C is a girder discriminant.
-- If they are both false then Old_C is a regular component.
-----------------------
-- Inherit_Component --
-----------------------
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Girder_Discrim : Boolean := False)
is
New_C : Entity_Id := New_Copy (Old_C);
Discrim : Entity_Id;
Corr_Discrim : Entity_Id;
begin
pragma Assert (not Is_Tagged or else not Girder_Discrim);
Set_Parent (New_C, Parent (Old_C));
-- Regular discriminants and components must be inserted
-- in the scope of the Derived_Base. Do it here.
if not Girder_Discrim then
Enter_Name (New_C);
end if;
-- For tagged types the Original_Record_Component must point to
-- whatever this field was pointing to in the parent type. This has
-- already been achieved by the call to New_Copy above.
if not Is_Tagged then
Set_Original_Record_Component (New_C, New_C);
end if;
-- If we have inherited a component then see if its Etype contains
-- references to Parent_Base discriminants. In this case, replace
-- these references with the constraints given in Discs. We do not
-- do this for the partial view of private types because this is
-- not needed (only the components of the full view will be used
-- for code generation) and cause problem. We also avoid this
-- transformation in some error situations.
if Ekind (New_C) = E_Component then
if (Is_Private_Type (Derived_Base)
and then not Is_Generic_Type (Derived_Base))
or else (Is_Empty_Elmt_List (Discs)
and then not Expander_Active)
then
Set_Etype (New_C, Etype (Old_C));
else
Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
Derived_Base, N, Parent_Base, Discs));
end if;
end if;
-- In derived tagged types it is illegal to reference a non
-- discriminant component in the parent type. To catch this, mark
-- these components with an Ekind of E_Void. This will be reset in
-- Record_Type_Definition after processing the record extension of
-- the derived type.
if Is_Tagged and then Ekind (New_C) = E_Component then
Set_Ekind (New_C, E_Void);
end if;
if Plain_Discrim then
Set_Corresponding_Discriminant (New_C, Old_C);
Build_Discriminal (New_C);
-- If we are explicitly inheriting a girder discriminant it will be
-- completely hidden.
elsif Girder_Discrim then
Set_Corresponding_Discriminant (New_C, Empty);
Set_Discriminal (New_C, Empty);
Set_Is_Completely_Hidden (New_C);
-- Set the Original_Record_Component of each discriminant in the
-- derived base to point to the corresponding girder that we just
-- created.
Discrim := First_Discriminant (Derived_Base);
while Present (Discrim) loop
Corr_Discrim := Corresponding_Discriminant (Discrim);
-- Corr_Discrimm could be missing in an error situation.
if Present (Corr_Discrim)
and then Original_Record_Component (Corr_Discrim) = Old_C
then
Set_Original_Record_Component (Discrim, New_C);
end if;
Next_Discriminant (Discrim);
end loop;
Append_Entity (New_C, Derived_Base);
end if;
if not Is_Tagged then
Append_Elmt (Old_C, Assoc_List);
Append_Elmt (New_C, Assoc_List);
end if;
end Inherit_Component;
-- Variables local to Inherit_Components.
Loc : constant Source_Ptr := Sloc (N);
Parent_Discrim : Entity_Id;
Girder_Discrim : Entity_Id;
D : Entity_Id;
Component : Entity_Id;
-- Start of processing for Inherit_Components
begin
if not Is_Tagged then
Append_Elmt (Parent_Base, Assoc_List);
Append_Elmt (Derived_Base, Assoc_List);
end if;
-- Inherit parent discriminants if needed.
if Inherit_Discr then
Parent_Discrim := First_Discriminant (Parent_Base);
while Present (Parent_Discrim) loop
Inherit_Component (Parent_Discrim, Plain_Discrim => True);
Next_Discriminant (Parent_Discrim);
end loop;
end if;
-- Create explicit girder discrims for untagged types when necessary.
if not Has_Unknown_Discriminants (Derived_Base)
and then Has_Discriminants (Parent_Base)
and then not Is_Tagged
and then
(not Inherit_Discr
or else First_Discriminant (Parent_Base) /=
First_Girder_Discriminant (Parent_Base))
then
Girder_Discrim := First_Girder_Discriminant (Parent_Base);
while Present (Girder_Discrim) loop
Inherit_Component (Girder_Discrim, Girder_Discrim => True);
Next_Girder_Discriminant (Girder_Discrim);
end loop;
end if;
-- See if we can apply the second transformation for derived types, as
-- explained in point 6. in the comments above Build_Derived_Record_Type
-- This is achieved by appending Derived_Base discriminants into
-- Discs, which has the side effect of returning a non empty Discs
-- list to the caller of Inherit_Components, which is what we want.
if Inherit_Discr
and then Is_Empty_Elmt_List (Discs)
and then (not Is_Private_Type (Derived_Base)
or Is_Generic_Type (Derived_Base))
then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Append_Elmt (New_Reference_To (D, Loc), Discs);
Next_Discriminant (D);
end loop;
end if;
-- Finally, inherit non-discriminant components unless they are not
-- visible because defined or inherited from the full view of the
-- parent. Don't inherit the _parent field of the parent type.
Component := First_Entity (Parent_Base);
while Present (Component) loop
if Ekind (Component) /= E_Component
or else Chars (Component) = Name_uParent
then
null;
-- If the derived type is within the parent type's declarative
-- region, then the components can still be inherited even though
-- they aren't visible at this point. This can occur for cases
-- such as within public child units where the components must
-- become visible upon entering the child unit's private part.
elsif not Is_Visible_Component (Component)
and then not In_Open_Scopes (Scope (Parent_Base))
then
null;
elsif Ekind (Derived_Base) = E_Private_Type
or else Ekind (Derived_Base) = E_Limited_Private_Type
then
null;
else
Inherit_Component (Component);
end if;
Next_Entity (Component);
end loop;
-- For tagged derived types, inherited discriminants cannot be used in
-- component declarations of the record extension part. To achieve this
-- we mark the inherited discriminants as not visible.
if Is_Tagged and then Inherit_Discr then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Set_Is_Immediately_Visible (D, False);
Next_Discriminant (D);
end loop;
end if;
return Assoc_List;
end Inherit_Components;
------------------------------
-- Is_Valid_Constraint_Kind --
------------------------------
function Is_Valid_Constraint_Kind
(T_Kind : Type_Kind;
Constraint_Kind : Node_Kind)
return Boolean
is
begin
case T_Kind is
when Enumeration_Kind |
Integer_Kind =>
return Constraint_Kind = N_Range_Constraint;
when Decimal_Fixed_Point_Kind =>
return
Constraint_Kind = N_Digits_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Ordinary_Fixed_Point_Kind =>
return
Constraint_Kind = N_Delta_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Float_Kind =>
return
Constraint_Kind = N_Digits_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Access_Kind |
Array_Kind |
E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
E_Incomplete_Type |
Private_Kind |
Concurrent_Kind =>
return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
when others =>
return True; -- Error will be detected later.
end case;
end Is_Valid_Constraint_Kind;
--------------------------
-- Is_Visible_Component --
--------------------------
function Is_Visible_Component (C : Entity_Id) return Boolean is
Original_Comp : constant Entity_Id := Original_Record_Component (C);
Original_Scope : Entity_Id;
begin
if No (Original_Comp) then
-- Premature usage, or previous error
return False;
else
Original_Scope := Scope (Original_Comp);
end if;
-- This test only concern tagged types
if not Is_Tagged_Type (Original_Scope) then
return True;
-- If it is _Parent or _Tag, there is no visiblity issue
elsif not Comes_From_Source (Original_Comp) then
return True;
-- If we are in the body of an instantiation, the component is
-- visible even when the parent type (possibly defined in an
-- enclosing unit or in a parent unit) might not.
elsif In_Instance_Body then
return True;
-- Discriminants are always visible.
elsif Ekind (Original_Comp) = E_Discriminant
and then not Has_Unknown_Discriminants (Original_Scope)
then
return True;
-- If the component has been declared in an ancestor which is
-- currently a private type, then it is not visible. The same
-- applies if the component's containing type is not in an
-- open scope and the original component's enclosing type
-- is a visible full type of a private type (which can occur
-- in cases where an attempt is being made to reference a
-- component in a sibling package that is inherited from
-- a visible component of a type in an ancestor package;
-- the component in the sibling package should not be
-- visible even though the component it inherited from
-- is visible). This does not apply however in the case
-- where the scope of the type is a private child unit.
-- The latter suppression of visibility is needed for cases
-- that are tested in B730006.
elsif (Ekind (Original_Comp) /= E_Discriminant
or else Has_Unknown_Discriminants (Original_Scope))
and then
(Is_Private_Type (Original_Scope)
or else
(not Is_Private_Descendant (Scope (Base_Type (Scope (C))))
and then not In_Open_Scopes (Scope (Base_Type (Scope (C))))
and then Has_Private_Declaration (Original_Scope)))
then
return False;
-- There is another weird way in which a component may be invisible
-- when the private and the full view are not derived from the same
-- ancestor. Here is an example :
-- type A1 is tagged record F1 : integer; end record;
-- type A2 is new A1 with record F2 : integer; end record;
-- type T is new A1 with private;
-- private
-- type T is new A2 with private;
-- In this case, the full view of T inherits F1 and F2 but the
-- private view inherits only F1
else
declare
Ancestor : Entity_Id := Scope (C);
begin
loop
if Ancestor = Original_Scope then
return True;
elsif Ancestor = Etype (Ancestor) then
return False;
end if;
Ancestor := Etype (Ancestor);
end loop;
return True;
end;
end if;
end Is_Visible_Component;
--------------------------
-- Make_Class_Wide_Type --
--------------------------
procedure Make_Class_Wide_Type (T : Entity_Id) is
CW_Type : Entity_Id;
CW_Name : Name_Id;
Next_E : Entity_Id;
begin
-- The class wide type can have been defined by the partial view in
-- which case everything is already done
if Present (Class_Wide_Type (T)) then
return;
end if;
CW_Type :=
New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
-- Inherit root type characteristics
CW_Name := Chars (CW_Type);
Next_E := Next_Entity (CW_Type);
Copy_Node (T, CW_Type);
Set_Comes_From_Source (CW_Type, False);
Set_Chars (CW_Type, CW_Name);
Set_Parent (CW_Type, Parent (T));
Set_Next_Entity (CW_Type, Next_E);
Set_Has_Delayed_Freeze (CW_Type);
-- Customize the class-wide type: It has no prim. op., it cannot be
-- abstract and its Etype points back to the root type
Set_Ekind (CW_Type, E_Class_Wide_Type);
Set_Is_Tagged_Type (CW_Type, True);
Set_Primitive_Operations (CW_Type, New_Elmt_List);
Set_Is_Abstract (CW_Type, False);
Set_Etype (CW_Type, T);
Set_Is_Constrained (CW_Type, False);
Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
Init_Size_Align (CW_Type);
-- If this is the class_wide type of a constrained subtype, it does
-- not have discriminants.
Set_Has_Discriminants (CW_Type,
Has_Discriminants (T) and then not Is_Constrained (T));
Set_Has_Unknown_Discriminants (CW_Type, True);
Set_Class_Wide_Type (T, CW_Type);
Set_Equivalent_Type (CW_Type, Empty);
-- The class-wide type of a class-wide type is itself (RM 3.9(14))
Set_Class_Wide_Type (CW_Type, CW_Type);
end Make_Class_Wide_Type;
----------------
-- Make_Index --
----------------
procedure Make_Index
(I : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix_Index : Nat := 1)
is
R : Node_Id;
T : Entity_Id;
Def_Id : Entity_Id := Empty;
Found : Boolean := False;
begin
-- For a discrete range used in a constrained array definition and
-- defined by a range, an implicit conversion to the predefined type
-- INTEGER is assumed if each bound is either a numeric literal, a named
-- number, or an attribute, and the type of both bounds (prior to the
-- implicit conversion) is the type universal_integer. Otherwise, both
-- bounds must be of the same discrete type, other than universal
-- integer; this type must be determinable independently of the
-- context, but using the fact that the type must be discrete and that
-- both bounds must have the same type.
-- Character literals also have a universal type in the absence of
-- of additional context, and are resolved to Standard_Character.
if Nkind (I) = N_Range then
-- The index is given by a range constraint. The bounds are known
-- to be of a consistent type.
if not Is_Overloaded (I) then
T := Etype (I);
-- If the bounds are universal, choose the specific predefined
-- type.
if T = Universal_Integer then
T := Standard_Integer;
elsif T = Any_Character then
if not Ada_83 then
Error_Msg_N
("ambiguous character literals (could be Wide_Character)",
I);
end if;
T := Standard_Character;
end if;
else
T := Any_Type;
declare
Ind : Interp_Index;
It : Interp;
begin
Get_First_Interp (I, Ind, It);
while Present (It.Typ) loop
if Is_Discrete_Type (It.Typ) then
if Found
and then not Covers (It.Typ, T)
and then not Covers (T, It.Typ)
then
Error_Msg_N ("ambiguous bounds in discrete range", I);
exit;
else
T := It.Typ;
Found := True;
end if;
end if;
Get_Next_Interp (Ind, It);
end loop;
if T = Any_Type then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
elsif T = Universal_Integer then
T := Standard_Integer;
end if;
end;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
end if;
R := I;
Process_Range_Expr_In_Decl (R, T, Related_Nod);
elsif Nkind (I) = N_Subtype_Indication then
-- The index is given by a subtype with a range constraint.
T := Base_Type (Entity (Subtype_Mark (I)));
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
end if;
R := Range_Expression (Constraint (I));
Resolve (R, T);
Process_Range_Expr_In_Decl (R,
Entity (Subtype_Mark (I)), Related_Nod);
elsif Nkind (I) = N_Attribute_Reference then
-- The parser guarantees that the attribute is a RANGE attribute
Analyze_And_Resolve (I);
T := Etype (I);
R := I;
-- If none of the above, must be a subtype. We convert this to a
-- range attribute reference because in the case of declared first
-- named subtypes, the types in the range reference can be different
-- from the type of the entity. A range attribute normalizes the
-- reference and obtains the correct types for the bounds.
-- This transformation is in the nature of an expansion, is only
-- done if expansion is active. In particular, it is not done on
-- formal generic types, because we need to retain the name of the
-- original index for instantiation purposes.
else
if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
Error_Msg_N ("invalid subtype mark in discrete range ", I);
Set_Etype (I, Any_Integer);
return;
else
-- The type mark may be that of an incomplete type. It is only
-- now that we can get the full view, previous analysis does
-- not look specifically for a type mark.
Set_Entity (I, Get_Full_View (Entity (I)));
Set_Etype (I, Entity (I));
Def_Id := Entity (I);
if not Is_Discrete_Type (Def_Id) then
Error_Msg_N ("discrete type required for index", I);
Set_Etype (I, Any_Type);
return;
end if;
end if;
if Expander_Active then
Rewrite (I,
Make_Attribute_Reference (Sloc (I),
Attribute_Name => Name_Range,
Prefix => Relocate_Node (I)));
-- The original was a subtype mark that does not freeze. This
-- means that the rewritten version must not freeze either.
Set_Must_Not_Freeze (I);
Set_Must_Not_Freeze (Prefix (I));
-- Is order critical??? if so, document why, if not
-- use Analyze_And_Resolve
Analyze (I);
T := Etype (I);
Resolve (I, T);
R := I;
else
-- Type is legal, nothing else to construct.
return;
end if;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
elsif T = Any_Type then
Set_Etype (I, Any_Type);
return;
end if;
-- We will now create the appropriate Itype to describe the
-- range, but first a check. If we originally had a subtype,
-- then we just label the range with this subtype. Not only
-- is there no need to construct a new subtype, but it is wrong
-- to do so for two reasons:
-- 1. A legality concern, if we have a subtype, it must not
-- freeze, and the Itype would cause freezing incorrectly
-- 2. An efficiency concern, if we created an Itype, it would
-- not be recognized as the same type for the purposes of
-- eliminating checks in some circumstances.
-- We signal this case by setting the subtype entity in Def_Id.
-- It would be nice to also do this optimization for the cases
-- of X'Range and also the explicit range X'First .. X'Last,
-- but that is not done yet (it is just an efficiency concern) ???
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Is_Signed_Integer_Type (T) then
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
elsif Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
end if;
Set_Size_Info (Def_Id, (T));
Set_RM_Size (Def_Id, RM_Size (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Scalar_Range (Def_Id, R);
Conditional_Delay (Def_Id, T);
-- In the subtype indication case, if the immediate parent of the
-- new subtype is non-static, then the subtype we create is non-
-- static, even if its bounds are static.
if Nkind (I) = N_Subtype_Indication
and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
then
Set_Is_Non_Static_Subtype (Def_Id);
end if;
end if;
-- Final step is to label the index with this constructed type
Set_Etype (I, Def_Id);
end Make_Index;
------------------------------
-- Modular_Type_Declaration --
------------------------------
procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Mod_Expr : constant Node_Id := Expression (Def);
M_Val : Uint;
procedure Set_Modular_Size (Bits : Int);
-- Sets RM_Size to Bits, and Esize to normal word size above this
procedure Set_Modular_Size (Bits : Int) is
begin
Set_RM_Size (T, UI_From_Int (Bits));
if Bits <= 8 then
Init_Esize (T, 8);
elsif Bits <= 16 then
Init_Esize (T, 16);
elsif Bits <= 32 then
Init_Esize (T, 32);
else
Init_Esize (T, System_Max_Binary_Modulus_Power);
end if;
end Set_Modular_Size;
-- Start of processing for Modular_Type_Declaration
begin
Analyze_And_Resolve (Mod_Expr, Any_Integer);
Set_Etype (T, T);
Set_Ekind (T, E_Modular_Integer_Type);
Init_Alignment (T);
Set_Is_Constrained (T);
if not Is_OK_Static_Expression (Mod_Expr) then
Error_Msg_N
("non-static expression used for modular type bound", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
else
M_Val := Expr_Value (Mod_Expr);
end if;
if M_Val < 1 then
Error_Msg_N ("modulus value must be positive", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
end if;
Set_Modulus (T, M_Val);
-- Create bounds for the modular type based on the modulus given in
-- the type declaration and then analyze and resolve those bounds.
Set_Scalar_Range (T,
Make_Range (Sloc (Mod_Expr),
Low_Bound =>
Make_Integer_Literal (Sloc (Mod_Expr), 0),
High_Bound =>
Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
-- Properly analyze the literals for the range. We do this manually
-- because we can't go calling Resolve, since we are resolving these
-- bounds with the type, and this type is certainly not complete yet!
Set_Etype (Low_Bound (Scalar_Range (T)), T);
Set_Etype (High_Bound (Scalar_Range (T)), T);
Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
-- Loop through powers of two to find number of bits required
for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
-- Binary case
if M_Val = 2 ** Bits then
Set_Modular_Size (Bits);
return;
-- Non-binary case
elsif M_Val < 2 ** Bits then
Set_Non_Binary_Modulus (T);
if Bits > System_Max_Nonbinary_Modulus_Power then
Error_Msg_Uint_1 :=
UI_From_Int (System_Max_Nonbinary_Modulus_Power);
Error_Msg_N
("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
return;
else
-- In the non-binary case, set size as per RM 13.3(55).
Set_Modular_Size (Bits);
return;
end if;
end if;
end loop;
-- If we fall through, then the size exceed System.Max_Binary_Modulus
-- so we just signal an error and set the maximum size.
Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
Init_Alignment (T);
end Modular_Type_Declaration;
-------------------------
-- New_Binary_Operator --
-------------------------
procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Typ);
Op : Entity_Id;
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
-- Create abbreviated declaration for the formal of a predefined
-- Operator 'Op' of type 'Typ'
--------------------
-- Make_Op_Formal --
--------------------
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
Formal : Entity_Id;
begin
Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
Set_Etype (Formal, Typ);
Set_Mechanism (Formal, Default_Mechanism);
return Formal;
end Make_Op_Formal;
-- Start of processing for New_Binary_Operator
begin
Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
Set_Ekind (Op, E_Operator);
Set_Scope (Op, Current_Scope);
Set_Etype (Op, Typ);
Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
Set_Is_Immediately_Visible (Op);
Set_Is_Intrinsic_Subprogram (Op);
Set_Has_Completion (Op);
Append_Entity (Op, Current_Scope);
Set_Name_Entity_Id (Op_Name, Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
end New_Binary_Operator;
-------------------------------------------
-- Ordinary_Fixed_Point_Type_Declaration --
-------------------------------------------
procedure Ordinary_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
RRS : constant Node_Id := Real_Range_Specification (Def);
Implicit_Base : Entity_Id;
Delta_Val : Ureal;
Small_Val : Ureal;
Low_Val : Ureal;
High_Val : Ureal;
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Any_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
Set_Delta_Value (Implicit_Base, Delta_Val);
-- Compute default small from given delta, which is the largest
-- power of two that does not exceed the given delta value.
declare
Tmp : Ureal := Ureal_1;
Scale : Int := 0;
begin
if Delta_Val < Ureal_1 then
while Delta_Val < Tmp loop
Tmp := Tmp / Ureal_2;
Scale := Scale + 1;
end loop;
else
loop
Tmp := Tmp * Ureal_2;
exit when Tmp > Delta_Val;
Scale := Scale - 1;
end loop;
end if;
Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
end;
Set_Small_Value (Implicit_Base, Small_Val);
-- If no range was given, set a dummy range
if RRS <= Empty_Or_Error then
Low_Val := -Small_Val;
High_Val := Small_Val;
-- Otherwise analyze and process given range
else
declare
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
-- Obtain and set the range
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val > High_Val then
Error_Msg_NE ("?fixed point type& has null range", Def, T);
end if;
end;
end if;
-- The range for both the implicit base and the declared first
-- subtype cannot be set yet, so we use the special routine
-- Set_Fixed_Range to set a temporary range in place. Note that
-- the bounds of the base type will be widened to be symmetrical
-- and to fill the available bits when the type is frozen.
-- We could do this with all discrete types, and probably should, but
-- we absolutely have to do it for fixed-point, since the end-points
-- of the range and the size are determined by the small value, which
-- could be reset before the freeze point.
Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
Init_Size_Align (Implicit_Base);
-- Complete definition of first subtype
Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Init_Size_Align (T);
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Small_Value (T, Small_Val);
Set_Delta_Value (T, Delta_Val);
Set_Is_Constrained (T);
end Ordinary_Fixed_Point_Type_Declaration;
----------------------------------------
-- Prepare_Private_Subtype_Completion --
----------------------------------------
procedure Prepare_Private_Subtype_Completion
(Id : Entity_Id;
Related_Nod : Node_Id)
is
Id_B : constant Entity_Id := Base_Type (Id);
Full_B : constant Entity_Id := Full_View (Id_B);
Full : Entity_Id;
begin
if Present (Full_B) then
-- The Base_Type is already completed, we can complete the
-- subtype now. We have to create a new entity with the same name,
-- Thus we can't use Create_Itype.
-- This is messy, should be fixed ???
Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
Set_Is_Itype (Full);
Set_Associated_Node_For_Itype (Full, Related_Nod);
Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
end if;
-- The parent subtype may be private, but the base might not, in some
-- nested instances. In that case, the subtype does not need to be
-- exchanged. It would still be nice to make private subtypes and their
-- bases consistent at all times ???
if Is_Private_Type (Id_B) then
Append_Elmt (Id, Private_Dependents (Id_B));
end if;
end Prepare_Private_Subtype_Completion;
---------------------------
-- Process_Discriminants --
---------------------------
procedure Process_Discriminants (N : Node_Id) is
Id : Node_Id;
Discr : Node_Id;
Discr_Number : Uint;
Discr_Type : Entity_Id;
Default_Present : Boolean := False;
Default_Not_Present : Boolean := False;
Elist : Elist_Id := New_Elmt_List;
begin
-- A composite type other than an array type can have discriminants.
-- Discriminants of non-limited types must have a discrete type.
-- On entry, the current scope is the composite type.
-- The discriminants are initially entered into the scope of the type
-- via Enter_Name with the default Ekind of E_Void to prevent premature
-- use, as explained at the end of this procedure.
Discr := First (Discriminant_Specifications (N));
while Present (Discr) loop
Enter_Name (Defining_Identifier (Discr));
if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
else
Find_Type (Discriminant_Type (Discr));
Discr_Type := Etype (Discriminant_Type (Discr));
if Error_Posted (Discriminant_Type (Discr)) then
Discr_Type := Any_Type;
end if;
end if;
if Is_Access_Type (Discr_Type) then
Check_Access_Discriminant_Requires_Limited
(Discr, Discriminant_Type (Discr));
if Ada_83 and then Comes_From_Source (Discr) then
Error_Msg_N
("(Ada 83) access discriminant not allowed", Discr);
end if;
elsif not Is_Discrete_Type (Discr_Type) then
Error_Msg_N ("discriminants must have a discrete or access type",
Discriminant_Type (Discr));
end if;
Set_Etype (Defining_Identifier (Discr), Discr_Type);
-- If a discriminant specification includes the assignment compound
-- delimiter followed by an expression, the expression is the default
-- expression of the discriminant; the default expression must be of
-- the type of the discriminant. (RM 3.7.1) Since this expression is
-- a default expression, we do the special preanalysis, since this
-- expression does not freeze (see "Handling of Default Expressions"
-- in spec of package Sem).
if Present (Expression (Discr)) then
Analyze_Default_Expression (Expression (Discr), Discr_Type);
if Nkind (N) = N_Formal_Type_Declaration then
Error_Msg_N
("discriminant defaults not allowed for formal type",
Expression (Discr));
elsif Is_Tagged_Type (Current_Scope) then
Error_Msg_N
("discriminants of tagged type cannot have defaults",
Expression (Discr));
else
Default_Present := True;
Append_Elmt (Expression (Discr), Elist);
-- Tag the defining identifiers for the discriminants with
-- their corresponding default expressions from the tree.
Set_Discriminant_Default_Value
(Defining_Identifier (Discr), Expression (Discr));
end if;
else
Default_Not_Present := True;
end if;
Next (Discr);
end loop;
-- An element list consisting of the default expressions of the
-- discriminants is constructed in the above loop and used to set
-- the Discriminant_Constraint attribute for the type. If an object
-- is declared of this (record or task) type without any explicit
-- discriminant constraint given, this element list will form the
-- actual parameters for the corresponding initialization procedure
-- for the type.
Set_Discriminant_Constraint (Current_Scope, Elist);
Set_Girder_Constraint (Current_Scope, No_Elist);
-- Default expressions must be provided either for all or for none
-- of the discriminants of a discriminant part. (RM 3.7.1)
if Default_Present and then Default_Not_Present then
Error_Msg_N
("incomplete specification of defaults for discriminants", N);
end if;
-- The use of the name of a discriminant is not allowed in default
-- expressions of a discriminant part if the specification of the
-- discriminant is itself given in the discriminant part. (RM 3.7.1)
-- To detect this, the discriminant names are entered initially with an
-- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
-- attempt to use a void entity (for example in an expression that is
-- type-checked) produces the error message: premature usage. Now after
-- completing the semantic analysis of the discriminant part, we can set
-- the Ekind of all the discriminants appropriately.
Discr := First (Discriminant_Specifications (N));
Discr_Number := Uint_1;
while Present (Discr) loop
Id := Defining_Identifier (Discr);
Set_Ekind (Id, E_Discriminant);
Init_Component_Location (Id);
Init_Esize (Id);
Set_Discriminant_Number (Id, Discr_Number);
-- Make sure this is always set, even in illegal programs
Set_Corresponding_Discriminant (Id, Empty);
-- Initialize the Original_Record_Component to the entity itself.
-- Inherit_Components will propagate the right value to
-- discriminants in derived record types.
Set_Original_Record_Component (Id, Id);
-- Create the discriminal for the discriminant.
Build_Discriminal (Id);
Next (Discr);
Discr_Number := Discr_Number + 1;
end loop;
Set_Has_Discriminants (Current_Scope);
end Process_Discriminants;
-----------------------
-- Process_Full_View --
-----------------------
procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
Priv_Parent : Entity_Id;
Full_Parent : Entity_Id;
Full_Indic : Node_Id;
begin
-- First some sanity checks that must be done after semantic
-- decoration of the full view and thus cannot be placed with other
-- similar checks in Find_Type_Name
if not Is_Limited_Type (Priv_T)
and then (Is_Limited_Type (Full_T)
or else Is_Limited_Composite (Full_T))
then
Error_Msg_N
("completion of nonlimited type cannot be limited", Full_T);
elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
Error_Msg_N
("completion of nonabstract type cannot be abstract", Full_T);
elsif Is_Tagged_Type (Priv_T)
and then Is_Limited_Type (Priv_T)
and then not Is_Limited_Type (Full_T)
then
-- GNAT allow its own definition of Limited_Controlled to disobey
-- this rule in order in ease the implementation. The next test is
-- safe because Root_Controlled is defined in a private system child
if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
Set_Is_Limited_Composite (Full_T);
else
Error_Msg_N
("completion of limited tagged type must be limited", Full_T);
end if;
elsif Is_Generic_Type (Priv_T) then
Error_Msg_N ("generic type cannot have a completion", Full_T);
end if;
if Is_Tagged_Type (Priv_T)
and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
and then Is_Derived_Type (Full_T)
then
Priv_Parent := Etype (Priv_T);
-- The full view of a private extension may have been transformed
-- into an unconstrained derived type declaration and a subtype
-- declaration (see build_derived_record_type for details).
if Nkind (N) = N_Subtype_Declaration then
Full_Indic := Subtype_Indication (N);
Full_Parent := Etype (Base_Type (Full_T));
else
Full_Indic := Subtype_Indication (Type_Definition (N));
Full_Parent := Etype (Full_T);
end if;
-- Check that the parent type of the full type is a descendant of
-- the ancestor subtype given in the private extension. If either
-- entity has an Etype equal to Any_Type then we had some previous
-- error situation [7.3(8)].
if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
return;
elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
Error_Msg_N
("parent of full type must descend from parent"
& " of private extension", Full_Indic);
-- Check the rules of 7.3(10): if the private extension inherits
-- known discriminants, then the full type must also inherit those
-- discriminants from the same (ancestor) type, and the parent
-- subtype of the full type must be constrained if and only if
-- the ancestor subtype of the private extension is constrained.
elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
and then not Has_Unknown_Discriminants (Priv_T)
and then Has_Discriminants (Base_Type (Priv_Parent))
then
declare
Priv_Indic : constant Node_Id :=
Subtype_Indication (Parent (Priv_T));
Priv_Constr : constant Boolean :=
Is_Constrained (Priv_Parent)
or else
Nkind (Priv_Indic) = N_Subtype_Indication
or else Is_Constrained (Entity (Priv_Indic));
Full_Constr : constant Boolean :=
Is_Constrained (Full_Parent)
or else
Nkind (Full_Indic) = N_Subtype_Indication
or else Is_Constrained (Entity (Full_Indic));
Priv_Discr : Entity_Id;
Full_Discr : Entity_Id;
begin
Priv_Discr := First_Discriminant (Priv_Parent);
Full_Discr := First_Discriminant (Full_Parent);
while Present (Priv_Discr) and then Present (Full_Discr) loop
if Original_Record_Component (Priv_Discr) =
Original_Record_Component (Full_Discr)
or else
Corresponding_Discriminant (Priv_Discr) =
Corresponding_Discriminant (Full_Discr)
then
null;
else
exit;
end if;
Next_Discriminant (Priv_Discr);
Next_Discriminant (Full_Discr);
end loop;
if Present (Priv_Discr) or else Present (Full_Discr) then
Error_Msg_N
("full view must inherit discriminants of the parent type"
& " used in the private extension", Full_Indic);
elsif Priv_Constr and then not Full_Constr then
Error_Msg_N
("parent subtype of full type must be constrained",
Full_Indic);
elsif Full_Constr and then not Priv_Constr then
Error_Msg_N
("parent subtype of full type must be unconstrained",
Full_Indic);
end if;
end;
-- Check the rules of 7.3(12): if a partial view has neither known
-- or unknown discriminants, then the full type declaration shall
-- define a definite subtype.
elsif not Has_Unknown_Discriminants (Priv_T)
and then not Has_Discriminants (Priv_T)
and then not Is_Constrained (Full_T)
then
Error_Msg_N
("full view must define a constrained type if partial view"
& " has no discriminants", Full_T);
end if;
-- ??????? Do we implement the following properly ?????
-- If the ancestor subtype of a private extension has constrained
-- discriminants, then the parent subtype of the full view shall
-- impose a statically matching constraint on those discriminants
-- [7.3(13)].
else
-- For untagged types, verify that a type without discriminants
-- is not completed with an unconstrained type.
if not Is_Indefinite_Subtype (Priv_T)
and then Is_Indefinite_Subtype (Full_T)
then
Error_Msg_N ("full view of type must be definite subtype", Full_T);
end if;
end if;
-- Create a full declaration for all its subtypes recorded in
-- Private_Dependents and swap them similarly to the base type.
-- These are subtypes that have been define before the full
-- declaration of the private type. We also swap the entry in
-- Private_Dependents list so we can properly restore the
-- private view on exit from the scope.
declare
Priv_Elmt : Elmt_Id;
Priv : Entity_Id;
Full : Entity_Id;
begin
Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
while Present (Priv_Elmt) loop
Priv := Node (Priv_Elmt);
if Ekind (Priv) = E_Private_Subtype
or else Ekind (Priv) = E_Limited_Private_Subtype
or else Ekind (Priv) = E_Record_Subtype_With_Private
then
Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
Set_Is_Itype (Full);
Set_Parent (Full, Parent (Priv));
Set_Associated_Node_For_Itype (Full, N);
-- Now we need to complete the private subtype, but since the
-- base type has already been swapped, we must also swap the
-- subtypes (and thus, reverse the arguments in the call to
-- Complete_Private_Subtype).
Copy_And_Swap (Priv, Full);
Complete_Private_Subtype (Full, Priv, Full_T, N);
Replace_Elmt (Priv_Elmt, Full);
end if;
Next_Elmt (Priv_Elmt);
end loop;
end;
-- If the private view was tagged, copy the new Primitive
-- operations from the private view to the full view.
if Is_Tagged_Type (Full_T) then
declare
Priv_List : Elist_Id;
Full_List : constant Elist_Id := Primitive_Operations (Full_T);
P1, P2 : Elmt_Id;
Prim : Entity_Id;
D_Type : Entity_Id;
begin
if Is_Tagged_Type (Priv_T) then
Priv_List := Primitive_Operations (Priv_T);
P1 := First_Elmt (Priv_List);
while Present (P1) loop
Prim := Node (P1);
-- Transfer explicit primitives, not those inherited from
-- parent of partial view, which will be re-inherited on
-- the full view.
if Comes_From_Source (Prim) then
P2 := First_Elmt (Full_List);
while Present (P2) and then Node (P2) /= Prim loop
Next_Elmt (P2);
end loop;
-- If not found, that is a new one
if No (P2) then
Append_Elmt (Prim, Full_List);
end if;
end if;
Next_Elmt (P1);
end loop;
else
-- In this case the partial view is untagged, so here we
-- locate all of the earlier primitives that need to be
-- treated as dispatching (those that appear between the
-- two views). Note that these additional operations must
-- all be new operations (any earlier operations that
-- override inherited operations of the full view will
-- already have been inserted in the primitives list and
-- marked as dispatching by Check_Operation_From_Private_View.
-- Note that implicit "/=" operators are excluded from being
-- added to the primitives list since they shouldn't be
-- treated as dispatching (tagged "/=" is handled specially).
Prim := Next_Entity (Full_T);
while Present (Prim) and then Prim /= Priv_T loop
if (Ekind (Prim) = E_Procedure
or else Ekind (Prim) = E_Function)
then
D_Type := Find_Dispatching_Type (Prim);
if D_Type = Full_T
and then (Chars (Prim) /= Name_Op_Ne
or else Comes_From_Source (Prim))
then
Check_Controlling_Formals (Full_T, Prim);
if not Is_Dispatching_Operation (Prim) then
Append_Elmt (Prim, Full_List);
Set_Is_Dispatching_Operation (Prim, True);
Set_DT_Position (Prim, No_Uint);
end if;
elsif Is_Dispatching_Operation (Prim)
and then D_Type /= Full_T
then
-- Verify that it is not otherwise controlled by
-- a formal or a return value ot type T.
Check_Controlling_Formals (D_Type, Prim);
end if;
end if;
Next_Entity (Prim);
end loop;
end if;
-- For the tagged case, the two views can share the same
-- Primitive Operation list and the same class wide type.
-- Update attributes of the class-wide type which depend on
-- the full declaration.
if Is_Tagged_Type (Priv_T) then
Set_Primitive_Operations (Priv_T, Full_List);
Set_Class_Wide_Type
(Base_Type (Full_T), Class_Wide_Type (Priv_T));
-- Any other attributes should be propagated to C_W ???
Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
end if;
end;
end if;
end Process_Full_View;
-----------------------------------
-- Process_Incomplete_Dependents --
-----------------------------------
procedure Process_Incomplete_Dependents
(N : Node_Id;
Full_T : Entity_Id;
Inc_T : Entity_Id)
is
Inc_Elmt : Elmt_Id;
Priv_Dep : Entity_Id;
New_Subt : Entity_Id;
Disc_Constraint : Elist_Id;
begin
if No (Private_Dependents (Inc_T)) then
return;
else
Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
-- Itypes that may be generated by the completion of an incomplete
-- subtype are not used by the back-end and not attached to the tree.
-- They are created only for constraint-checking purposes.
end if;
while Present (Inc_Elmt) loop
Priv_Dep := Node (Inc_Elmt);
if Ekind (Priv_Dep) = E_Subprogram_Type then
-- An Access_To_Subprogram type may have a return type or a
-- parameter type that is incomplete. Replace with the full view.
if Etype (Priv_Dep) = Inc_T then
Set_Etype (Priv_Dep, Full_T);
end if;
declare
Formal : Entity_Id;
begin
Formal := First_Formal (Priv_Dep);
while Present (Formal) loop
if Etype (Formal) = Inc_T then
Set_Etype (Formal, Full_T);
end if;
Next_Formal (Formal);
end loop;
end;
elsif Is_Overloadable (Priv_Dep) then
if Is_Tagged_Type (Full_T) then
-- Subprogram has an access parameter whose designated type
-- was incomplete. Reexamine declaration now, because it may
-- be a primitive operation of the full type.
Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
Set_Is_Dispatching_Operation (Priv_Dep);
Check_Controlling_Formals (Full_T, Priv_Dep);
end if;
elsif Ekind (Priv_Dep) = E_Subprogram_Body then
-- Can happen during processing of a body before the completion
-- of a TA type. Ignore, because spec is also on dependent list.
return;
-- Dependent is a subtype
else
-- We build a new subtype indication using the full view of the
-- incomplete parent. The discriminant constraints have been
-- elaborated already at the point of the subtype declaration.
New_Subt := Create_Itype (E_Void, N);
if Has_Discriminants (Full_T) then
Disc_Constraint := Discriminant_Constraint (Priv_Dep);
else
Disc_Constraint := No_Elist;
end if;
Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
Set_Full_View (Priv_Dep, New_Subt);
end if;
Next_Elmt (Inc_Elmt);
end loop;
end Process_Incomplete_Dependents;
--------------------------------
-- Process_Range_Expr_In_Decl --
--------------------------------
procedure Process_Range_Expr_In_Decl
(R : Node_Id;
T : Entity_Id;
Related_Nod : Node_Id;
Check_List : List_Id := Empty_List;
R_Check_Off : Boolean := False)
is
Lo, Hi : Node_Id;
R_Checks : Check_Result;
Type_Decl : Node_Id;
Def_Id : Entity_Id;
begin
Analyze_And_Resolve (R, Base_Type (T));
if Nkind (R) = N_Range then
Lo := Low_Bound (R);
Hi := High_Bound (R);
-- If there were errors in the declaration, try and patch up some
-- common mistakes in the bounds. The cases handled are literals
-- which are Integer where the expected type is Real and vice versa.
-- These corrections allow the compilation process to proceed further
-- along since some basic assumptions of the format of the bounds
-- are guaranteed.
if Etype (R) = Any_Type then
if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
Rewrite (Lo,
Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
Rewrite (Hi,
Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
Rewrite (Lo,
Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
Rewrite (Hi,
Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
end if;
Set_Etype (Lo, T);
Set_Etype (Hi, T);
end if;
-- If the bounds of the range have been mistakenly given as
-- string literals (perhaps in place of character literals),
-- then an error has already been reported, but we rewrite
-- the string literal as a bound of the range's type to
-- avoid blowups in later processing that looks at static
-- values.
if Nkind (Lo) = N_String_Literal then
Rewrite (Lo,
Make_Attribute_Reference (Sloc (Lo),
Attribute_Name => Name_First,
Prefix => New_Reference_To (T, Sloc (Lo))));
Analyze_And_Resolve (Lo);
end if;
if Nkind (Hi) = N_String_Literal then
Rewrite (Hi,
Make_Attribute_Reference (Sloc (Hi),
Attribute_Name => Name_First,
Prefix => New_Reference_To (T, Sloc (Hi))));
Analyze_And_Resolve (Hi);
end if;
-- If bounds aren't scalar at this point then exit, avoiding
-- problems with further processing of the range in this procedure.
if not Is_Scalar_Type (Etype (Lo)) then
return;
end if;
-- Resolve (actually Sem_Eval) has checked that the bounds are in
-- then range of the base type. Here we check whether the bounds
-- are in the range of the subtype itself. Note that if the bounds
-- represent the null range the Constraint_Error exception should
-- not be raised.
-- ??? The following code should be cleaned up as follows
-- 1. The Is_Null_Range (Lo, Hi) test should disapper since it
-- is done in the call to Range_Check (R, T); below
-- 2. The use of R_Check_Off should be investigated and possibly
-- removed, this would clean up things a bit.
if Is_Null_Range (Lo, Hi) then
null;
else
-- We use a flag here instead of suppressing checks on the
-- type because the type we check against isn't necessarily the
-- place where we put the check.
if not R_Check_Off then
R_Checks := Range_Check (R, T);
Type_Decl := Parent (R);
-- Look up tree to find an appropriate insertion point.
-- This seems really junk code, and very brittle, couldn't
-- we just use an insert actions call of some kind ???
while Present (Type_Decl) and then not
(Nkind (Type_Decl) = N_Full_Type_Declaration
or else
Nkind (Type_Decl) = N_Subtype_Declaration
or else
Nkind (Type_Decl) = N_Loop_Statement
or else
Nkind (Type_Decl) = N_Task_Type_Declaration
or else
Nkind (Type_Decl) = N_Single_Task_Declaration
or else
Nkind (Type_Decl) = N_Protected_Type_Declaration
or else
Nkind (Type_Decl) = N_Single_Protected_Declaration)
loop
Type_Decl := Parent (Type_Decl);
end loop;
-- Why would Type_Decl not be present??? Without this test,
-- short regression tests fail.
if Present (Type_Decl) then
if Nkind (Type_Decl) = N_Loop_Statement then
declare
Indic : Node_Id := Parent (R);
begin
while Present (Indic) and then not
(Nkind (Indic) = N_Subtype_Indication)
loop
Indic := Parent (Indic);
end loop;
if Present (Indic) then
Def_Id := Etype (Subtype_Mark (Indic));
Insert_Range_Checks
(R_Checks,
Type_Decl,
Def_Id,
Sloc (Type_Decl),
R,
Do_Before => True);
end if;
end;
else
Def_Id := Defining_Identifier (Type_Decl);
if (Ekind (Def_Id) = E_Record_Type
and then Depends_On_Discriminant (R))
or else
(Ekind (Def_Id) = E_Protected_Type
and then Has_Discriminants (Def_Id))
then
Append_Range_Checks
(R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
else
Insert_Range_Checks
(R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
end if;
end if;
end if;
end if;
end if;
end if;
Get_Index_Bounds (R, Lo, Hi);
if Expander_Active then
Force_Evaluation (Lo);
Force_Evaluation (Hi);
end if;
end Process_Range_Expr_In_Decl;
--------------------------------------
-- Process_Real_Range_Specification --
--------------------------------------
procedure Process_Real_Range_Specification (Def : Node_Id) is
Spec : constant Node_Id := Real_Range_Specification (Def);
Lo : Node_Id;
Hi : Node_Id;
Err : Boolean := False;
procedure Analyze_Bound (N : Node_Id);
-- Analyze and check one bound
procedure Analyze_Bound (N : Node_Id) is
begin
Analyze_And_Resolve (N, Any_Real);
if not Is_OK_Static_Expression (N) then
Error_Msg_N
("bound in real type definition is not static", N);
Err := True;
end if;
end Analyze_Bound;
begin
if Present (Spec) then
Lo := Low_Bound (Spec);
Hi := High_Bound (Spec);
Analyze_Bound (Lo);
Analyze_Bound (Hi);
-- If error, clear away junk range specification
if Err then
Set_Real_Range_Specification (Def, Empty);
end if;
end if;
end Process_Real_Range_Specification;
---------------------
-- Process_Subtype --
---------------------
function Process_Subtype
(S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix : Character := ' ')
return Entity_Id
is
P : Node_Id;
Def_Id : Entity_Id;
Full_View_Id : Entity_Id;
Subtype_Mark_Id : Entity_Id;
N_Dynamic_Ityp : Node_Id := Empty;
begin
-- Case of constraint present, so that we have an N_Subtype_Indication
-- node (this node is created only if constraints are present).
if Nkind (S) = N_Subtype_Indication then
Find_Type (Subtype_Mark (S));
if Nkind (Parent (S)) /= N_Access_To_Object_Definition
and then not
(Nkind (Parent (S)) = N_Subtype_Declaration
and then
Is_Itype (Defining_Identifier (Parent (S))))
then
Check_Incomplete (Subtype_Mark (S));
end if;
P := Parent (S);
Subtype_Mark_Id := Entity (Subtype_Mark (S));
if Is_Unchecked_Union (Subtype_Mark_Id)
and then Comes_From_Source (Related_Nod)
then
Error_Msg_N
("cannot create subtype of Unchecked_Union", Related_Nod);
end if;
-- Explicit subtype declaration case
if Nkind (P) = N_Subtype_Declaration then
Def_Id := Defining_Identifier (P);
-- Explicit derived type definition case
elsif Nkind (P) = N_Derived_Type_Definition then
Def_Id := Defining_Identifier (Parent (P));
-- Implicit case, the Def_Id must be created as an implicit type.
-- The one exception arises in the case of concurrent types,
-- array and access types, where other subsidiary implicit types
-- may be created and must appear before the main implicit type.
-- In these cases we leave Def_Id set to Empty as a signal that
-- Create_Itype has not yet been called to create Def_Id.
else
if Is_Array_Type (Subtype_Mark_Id)
or else Is_Concurrent_Type (Subtype_Mark_Id)
or else Is_Access_Type (Subtype_Mark_Id)
then
Def_Id := Empty;
-- For the other cases, we create a new unattached Itype,
-- and set the indication to ensure it gets attached later.
else
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
N_Dynamic_Ityp := Related_Nod;
end if;
-- If the kind of constraint is invalid for this kind of type,
-- then give an error, and then pretend no constraint was given.
if not Is_Valid_Constraint_Kind
(Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
then
Error_Msg_N
("incorrect constraint for this kind of type", Constraint (S));
Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
-- Make recursive call, having got rid of the bogus constraint
return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
end if;
-- Remaining processing depends on type
case Ekind (Subtype_Mark_Id) is
when Access_Kind =>
Constrain_Access (Def_Id, S, Related_Nod);
when Array_Kind =>
Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
when Decimal_Fixed_Point_Kind =>
Constrain_Decimal (Def_Id, S, N_Dynamic_Ityp);
when Enumeration_Kind =>
Constrain_Enumeration (Def_Id, S, N_Dynamic_Ityp);
when Ordinary_Fixed_Point_Kind =>
Constrain_Ordinary_Fixed (Def_Id, S, N_Dynamic_Ityp);
when Float_Kind =>
Constrain_Float (Def_Id, S, N_Dynamic_Ityp);
when Integer_Kind =>
Constrain_Integer (Def_Id, S, N_Dynamic_Ityp);
when E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
E_Incomplete_Type =>
Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
when Private_Kind =>
Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
Set_Private_Dependents (Def_Id, New_Elmt_List);
-- In case of an invalid constraint prevent further processing
-- since the type constructed is missing expected fields.
if Etype (Def_Id) = Any_Type then
return Def_Id;
end if;
-- If the full view is that of a task with discriminants,
-- we must constrain both the concurrent type and its
-- corresponding record type. Otherwise we will just propagate
-- the constraint to the full view, if available.
if Present (Full_View (Subtype_Mark_Id))
and then Has_Discriminants (Subtype_Mark_Id)
and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
then
Full_View_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
Constrain_Concurrent (Full_View_Id, S,
Related_Nod, Related_Id, Suffix);
Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
Set_Full_View (Def_Id, Full_View_Id);
else
Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
end if;
when Concurrent_Kind =>
Constrain_Concurrent (Def_Id, S,
Related_Nod, Related_Id, Suffix);
when others =>
Error_Msg_N ("invalid subtype mark in subtype indication", S);
end case;
-- Size and Convention are always inherited from the base type
Set_Size_Info (Def_Id, (Subtype_Mark_Id));
Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
return Def_Id;
-- Case of no constraints present
else
Find_Type (S);
Check_Incomplete (S);
return Entity (S);
end if;
end Process_Subtype;
-----------------------------
-- Record_Type_Declaration --
-----------------------------
procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id) is
Def : constant Node_Id := Type_Definition (N);
Range_Checks_Suppressed_Flag : Boolean := False;
Is_Tagged : Boolean;
Tag_Comp : Entity_Id;
begin
-- The flag Is_Tagged_Type might have already been set by Find_Type_Name
-- if it detected an error for declaration T. This arises in the case of
-- private tagged types where the full view omits the word tagged.
Is_Tagged := Tagged_Present (Def)
or else (Errors_Detected > 0 and then Is_Tagged_Type (T));
-- Records constitute a scope for the component declarations within.
-- The scope is created prior to the processing of these declarations.
-- Discriminants are processed first, so that they are visible when
-- processing the other components. The Ekind of the record type itself
-- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
-- Enter record scope
New_Scope (T);
-- These flags must be initialized before calling Process_Discriminants
-- because this routine makes use of them.
Set_Is_Tagged_Type (T, Is_Tagged);
Set_Is_Limited_Record (T, Limited_Present (Def));
-- Type is abstract if full declaration carries keyword, or if
-- previous partial view did.
Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
Set_Ekind (T, E_Record_Type);
Set_Etype (T, T);
Init_Size_Align (T);
Set_Girder_Constraint (T, No_Elist);
-- If an incomplete or private type declaration was already given for
-- the type, then this scope already exists, and the discriminants have
-- been declared within. We must verify that the full declaration
-- matches the incomplete one.
Check_Or_Process_Discriminants (N, T);
Set_Is_Constrained (T, not Has_Discriminants (T));
Set_Has_Delayed_Freeze (T, True);
-- For tagged types add a manually analyzed component corresponding
-- to the component _tag, the corresponding piece of tree will be
-- expanded as part of the freezing actions if it is not a CPP_Class.
if Is_Tagged then
-- Do not add the tag unless we are in expansion mode.
if Expander_Active then
Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
Enter_Name (Tag_Comp);
Set_Is_Tag (Tag_Comp);
Set_Ekind (Tag_Comp, E_Component);
Set_Etype (Tag_Comp, RTE (RE_Tag));
Set_DT_Entry_Count (Tag_Comp, No_Uint);
Set_Original_Record_Component (Tag_Comp, Tag_Comp);
Init_Component_Location (Tag_Comp);
end if;
Make_Class_Wide_Type (T);
Set_Primitive_Operations (T, New_Elmt_List);
end if;
-- We must suppress range checks when processing the components
-- of a record in the presence of discriminants, since we don't
-- want spurious checks to be generated during their analysis, but
-- must reset the Suppress_Range_Checks flags after having procesed
-- the record definition.
if Has_Discriminants (T) and then not Suppress_Range_Checks (T) then
Set_Suppress_Range_Checks (T, True);
Range_Checks_Suppressed_Flag := True;
end if;
Record_Type_Definition (Def, T);
if Range_Checks_Suppressed_Flag then
Set_Suppress_Range_Checks (T, False);
Range_Checks_Suppressed_Flag := False;
end if;
-- Exit from record scope
End_Scope;
end Record_Type_Declaration;
----------------------------
-- Record_Type_Definition --
----------------------------
procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id) is
Component : Entity_Id;
Ctrl_Components : Boolean := False;
Final_Storage_Only : Boolean := not Is_Controlled (T);
begin
-- If the component list of a record type is defined by the reserved
-- word null and there is no discriminant part, then the record type has
-- no components and all records of the type are null records (RM 3.7)
-- This procedure is also called to process the extension part of a
-- record extension, in which case the current scope may have inherited
-- components.
if No (Def)
or else No (Component_List (Def))
or else Null_Present (Component_List (Def))
then
null;
else
Analyze_Declarations (Component_Items (Component_List (Def)));
if Present (Variant_Part (Component_List (Def))) then
Analyze (Variant_Part (Component_List (Def)));
end if;
end if;
-- After completing the semantic analysis of the record definition,
-- record components, both new and inherited, are accessible. Set
-- their kind accordingly.
Component := First_Entity (Current_Scope);
while Present (Component) loop
if Ekind (Component) = E_Void then
Set_Ekind (Component, E_Component);
Init_Component_Location (Component);
end if;
if Has_Task (Etype (Component)) then
Set_Has_Task (T);
end if;
if Ekind (Component) /= E_Component then
null;
elsif Has_Controlled_Component (Etype (Component))
or else (Chars (Component) /= Name_uParent
and then Is_Controlled (Etype (Component)))
then
Set_Has_Controlled_Component (T, True);
Final_Storage_Only := Final_Storage_Only
and then Finalize_Storage_Only (Etype (Component));
Ctrl_Components := True;
end if;
Next_Entity (Component);
end loop;
-- A type is Finalize_Storage_Only only if all its controlled
-- components are so.
if Ctrl_Components then
Set_Finalize_Storage_Only (T, Final_Storage_Only);
end if;
if Present (Def) then
Process_End_Label (Def, 'e');
end if;
end Record_Type_Definition;
---------------------
-- Set_Fixed_Range --
---------------------
-- The range for fixed-point types is complicated by the fact that we
-- do not know the exact end points at the time of the declaration. This
-- is true for three reasons:
-- A size clause may affect the fudging of the end-points
-- A small clause may affect the values of the end-points
-- We try to include the end-points if it does not affect the size
-- This means that the actual end-points must be established at the
-- point when the type is frozen. Meanwhile, we first narrow the range
-- as permitted (so that it will fit if necessary in a small specified
-- size), and then build a range subtree with these narrowed bounds.
-- Set_Fixed_Range constructs the range from real literal values, and
-- sets the range as the Scalar_Range of the given fixed-point type
-- entity.
-- The parent of this range is set to point to the entity so that it
-- is properly hooked into the tree (unlike normal Scalar_Range entries
-- for other scalar types, which are just pointers to the range in the
-- original tree, this would otherwise be an orphan).
-- The tree is left unanalyzed. When the type is frozen, the processing
-- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
-- analyzed, and uses this as an indication that it should complete
-- work on the range (it will know the final small and size values).
procedure Set_Fixed_Range
(E : Entity_Id;
Loc : Source_Ptr;
Lo : Ureal;
Hi : Ureal)
is
S : constant Node_Id :=
Make_Range (Loc,
Low_Bound => Make_Real_Literal (Loc, Lo),
High_Bound => Make_Real_Literal (Loc, Hi));
begin
Set_Scalar_Range (E, S);
Set_Parent (S, E);
end Set_Fixed_Range;
--------------------------------------------------------
-- Set_Girder_Constraint_From_Discriminant_Constraint --
--------------------------------------------------------
procedure Set_Girder_Constraint_From_Discriminant_Constraint
(E : Entity_Id)
is
begin
-- Make sure set if encountered during
-- Expand_To_Girder_Constraint
Set_Girder_Constraint (E, No_Elist);
-- Give it the right value
if Is_Constrained (E) and then Has_Discriminants (E) then
Set_Girder_Constraint (E,
Expand_To_Girder_Constraint (E, Discriminant_Constraint (E)));
end if;
end Set_Girder_Constraint_From_Discriminant_Constraint;
----------------------------------
-- Set_Scalar_Range_For_Subtype --
----------------------------------
procedure Set_Scalar_Range_For_Subtype
(Def_Id : Entity_Id;
R : Node_Id;
Subt : Entity_Id;
Related_Nod : Node_Id)
is
Kind : constant Entity_Kind := Ekind (Def_Id);
begin
Set_Scalar_Range (Def_Id, R);
-- We need to link the range into the tree before resolving it so
-- that types that are referenced, including importantly the subtype
-- itself, are properly frozen (Freeze_Expression requires that the
-- expression be properly linked into the tree). Of course if it is
-- already linked in, then we do not disturb the current link.
if No (Parent (R)) then
Set_Parent (R, Def_Id);
end if;
-- Reset the kind of the subtype during analysis of the range, to
-- catch possible premature use in the bounds themselves.
Set_Ekind (Def_Id, E_Void);
Process_Range_Expr_In_Decl (R, Subt, Related_Nod);
Set_Ekind (Def_Id, Kind);
end Set_Scalar_Range_For_Subtype;
-------------------------------------
-- Signed_Integer_Type_Declaration --
-------------------------------------
procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Implicit_Base : Entity_Id;
Base_Typ : Entity_Id;
Lo_Val : Uint;
Hi_Val : Uint;
Errs : Boolean := False;
Lo : Node_Id;
Hi : Node_Id;
function Can_Derive_From (E : Entity_Id) return Boolean;
-- Determine whether given bounds allow derivation from specified type
procedure Check_Bound (Expr : Node_Id);
-- Check bound to make sure it is integral and static. If not, post
-- appropriate error message and set Errs flag
function Can_Derive_From (E : Entity_Id) return Boolean is
Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
Hi : constant Uint := Expr_Value (Type_High_Bound (E));
begin
-- Note we check both bounds against both end values, to deal with
-- strange types like ones with a range of 0 .. -12341234.
return Lo <= Lo_Val and then Lo_Val <= Hi
and then
Lo <= Hi_Val and then Hi_Val <= Hi;
end Can_Derive_From;
procedure Check_Bound (Expr : Node_Id) is
begin
-- If a range constraint is used as an integer type definition, each
-- bound of the range must be defined by a static expression of some
-- integer type, but the two bounds need not have the same integer
-- type (Negative bounds are allowed.) (RM 3.5.4)
if not Is_Integer_Type (Etype (Expr)) then
Error_Msg_N
("integer type definition bounds must be of integer type", Expr);
Errs := True;
elsif not Is_OK_Static_Expression (Expr) then
Error_Msg_N
("non-static expression used for integer type bound", Expr);
Errs := True;
-- The bounds are folded into literals, and we set their type to be
-- universal, to avoid typing difficulties: we cannot set the type
-- of the literal to the new type, because this would be a forward
-- reference for the back end, and if the original type is user-
-- defined this can lead to spurious semantic errors (e.g. 2928-003).
else
if Is_Entity_Name (Expr) then
Fold_Uint (Expr, Expr_Value (Expr));
end if;
Set_Etype (Expr, Universal_Integer);
end if;
end Check_Bound;
-- Start of processing for Signed_Integer_Type_Declaration
begin
-- Create an anonymous base type
Implicit_Base :=
Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
-- Analyze and check the bounds, they can be of any integer type
Lo := Low_Bound (Def);
Hi := High_Bound (Def);
-- Arbitrarily use Integer as the type if either bound had an error
if Hi = Error or else Lo = Error then
Base_Typ := Any_Integer;
Set_Error_Posted (T, True);
-- Here both bounds are OK expressions
else
Analyze_And_Resolve (Lo, Any_Integer);
Analyze_And_Resolve (Hi, Any_Integer);
Check_Bound (Lo);
Check_Bound (Hi);
if Errs then
Hi := Type_High_Bound (Standard_Long_Long_Integer);
Lo := Type_Low_Bound (Standard_Long_Long_Integer);
end if;
-- Find type to derive from
Lo_Val := Expr_Value (Lo);
Hi_Val := Expr_Value (Hi);
if Can_Derive_From (Standard_Short_Short_Integer) then
Base_Typ := Base_Type (Standard_Short_Short_Integer);
elsif Can_Derive_From (Standard_Short_Integer) then
Base_Typ := Base_Type (Standard_Short_Integer);
elsif Can_Derive_From (Standard_Integer) then
Base_Typ := Base_Type (Standard_Integer);
elsif Can_Derive_From (Standard_Long_Integer) then
Base_Typ := Base_Type (Standard_Long_Integer);
elsif Can_Derive_From (Standard_Long_Long_Integer) then
Base_Typ := Base_Type (Standard_Long_Long_Integer);
else
Base_Typ := Base_Type (Standard_Long_Long_Integer);
Error_Msg_N ("integer type definition bounds out of range", Def);
Hi := Type_High_Bound (Standard_Long_Long_Integer);
Lo := Type_Low_Bound (Standard_Long_Long_Integer);
end if;
end if;
-- Complete both implicit base and declared first subtype entities
Set_Etype (Implicit_Base, Base_Typ);
Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
Set_Size_Info (Implicit_Base, (Base_Typ));
Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
Set_Ekind (T, E_Signed_Integer_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, (Implicit_Base));
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Scalar_Range (T, Def);
Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
Set_Is_Constrained (T);
end Signed_Integer_Type_Declaration;
end Sem_Ch3;