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-- --
-- --
-- E X P _ C H 1 3 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2003, 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. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch6; use Exp_Ch6;
with Exp_Imgv; use Exp_Imgv;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Eval; use Sem_Eval;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Exp_Ch13 is
procedure Expand_External_Tag_Definition (N : Node_Id);
-- The code to assign and register an external tag must be elaborated
-- after the dispatch table has been created, so the expansion of the
-- attribute definition node is delayed until after the type is frozen.
-- Expand_N_Attribute_Definition_Clause --
-- Expansion action depends on attribute involved
procedure Expand_N_Attribute_Definition_Clause (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Exp : constant Node_Id := Expression (N);
Ent : Entity_Id;
V : Node_Id;
Ent := Entity (Name (N));
if Is_Type (Ent) then
Ent := Underlying_Type (Ent);
end if;
case Get_Attribute_Id (Chars (N)) is
-- Address --
when Attribute_Address =>
-- If there is an initialization which did not come from
-- the source program, then it is an artifact of our
-- expansion, and we suppress it. The case we are most
-- concerned about here is the initialization of a packed
-- array to all false, which seems inappropriate for a
-- variable to which an address clause is applied. The
-- expression may itself have been rewritten if the type is a
-- packed array, so we need to examine whether the original
-- node is in the source.
Decl : constant Node_Id := Declaration_Node (Ent);
if Nkind (Decl) = N_Object_Declaration
and then Present (Expression (Decl))
and then
not Comes_From_Source (Original_Node (Expression (Decl)))
Set_Expression (Decl, Empty);
end if;
-- Alignment --
when Attribute_Alignment =>
-- As required by Gigi, we guarantee that the operand is an
-- integer literal (this simplifies things in Gigi).
if Nkind (Exp) /= N_Integer_Literal then
(Exp, Make_Integer_Literal (Loc, Expr_Value (Exp)));
end if;
-- Storage_Size --
when Attribute_Storage_Size =>
-- If the type is a task type, then assign the value of the
-- storage size to the Size variable associated with the task.
-- task_typeZ := expression
if Ekind (Ent) = E_Task_Type then
Insert_Action (N,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Storage_Size_Variable (Ent), Loc),
Expression =>
Convert_To (RTE (RE_Size_Type), Expression (N))));
-- For Storage_Size for an access type, create a variable to hold
-- the value of the specified size with name typeV and expand an
-- assignment statement to initialze this value.
elsif Is_Access_Type (Ent) then
V := Make_Defining_Identifier (Loc,
New_External_Name (Chars (Ent), 'V'));
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => V,
Object_Definition =>
New_Reference_To (RTE (RE_Storage_Offset), Loc),
Expression =>
Convert_To (RTE (RE_Storage_Offset), Expression (N))));
Set_Storage_Size_Variable (Ent, Entity_Id (V));
end if;
-- Other attributes require no expansion
when others =>
end case;
end Expand_N_Attribute_Definition_Clause;
-- Expand_External_Tag_Definition --
procedure Expand_External_Tag_Definition (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Entity_Id := Entity (Name (N));
Old_Val : constant String_Id := Strval (Expr_Value_S (Expression (N)));
New_Val : String_Id;
E : Entity_Id;
-- For the rep clause "for x'external_tag use y" generate:
-- xV : constant string := y;
-- Set_External_Tag (x'tag, xV'Address);
-- Register_Tag (x'tag);
-- note that register_tag has been delayed up to now because
-- the external_tag must be set before registering.
-- Create a new nul terminated string if it is not already
if String_Length (Old_Val) > 0
and then Get_String_Char (Old_Val, String_Length (Old_Val)) = 0
New_Val := Old_Val;
Start_String (Old_Val);
Store_String_Char (Get_Char_Code (ASCII.NUL));
New_Val := End_String;
end if;
E :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Ent), 'A'));
-- The generated actions must be elaborated at the subsequent
-- freeze point, not at the point of the attribute definition.
Append_Freeze_Action (Ent,
Make_Object_Declaration (Loc,
Defining_Identifier => E,
Constant_Present => True,
Object_Definition =>
New_Reference_To (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc, Strval => New_Val)));
Append_Freeze_Actions (Ent, New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Set_External_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Tag,
Prefix => New_Occurrence_Of (Ent, Loc)),
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Occurrence_Of (E, Loc)))),
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Register_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Tag,
Prefix => New_Occurrence_Of (Ent, Loc))))));
end Expand_External_Tag_Definition;
-- Expand_N_Freeze_Entity --
procedure Expand_N_Freeze_Entity (N : Node_Id) is
E : constant Entity_Id := Entity (N);
E_Scope : Entity_Id;
S : Entity_Id;
In_Other_Scope : Boolean;
In_Outer_Scope : Boolean;
Decl : Node_Id;
-- For object, with address clause, check alignment is OK
if Is_Object (E) then
Apply_Alignment_Check (E, N);
-- Only other items requiring any front end action are
-- types and subprograms.
elsif not Is_Type (E) and then not Is_Subprogram (E) then
end if;
-- Here E is a type or a subprogram
E_Scope := Scope (E);
-- This is an error protection against previous errors
if No (E_Scope) then
end if;
-- If we are freezing entities defined in protected types, they
-- belong in the enclosing scope, given that the original type
-- has been expanded away. The same is true for entities in task types,
-- in particular the parameter records of entries (Entities in bodies
-- are all frozen within the body). If we are in the task body, this
-- is a proper scope.
if Ekind (E_Scope) = E_Protected_Type
or else (Ekind (E_Scope) = E_Task_Type
and then not Has_Completion (E_Scope))
E_Scope := Scope (E_Scope);
end if;
S := Current_Scope;
while S /= Standard_Standard and then S /= E_Scope loop
S := Scope (S);
end loop;
In_Other_Scope := not (S = E_Scope);
In_Outer_Scope := (not In_Other_Scope) and then (S /= Current_Scope);
-- If the entity being frozen is defined in a scope that is not
-- currently on the scope stack, we must establish the proper
-- visibility before freezing the entity and related subprograms.
if In_Other_Scope then
New_Scope (E_Scope);
Install_Visible_Declarations (E_Scope);
if Ekind (E_Scope) = E_Package or else
Ekind (E_Scope) = E_Generic_Package or else
Is_Protected_Type (E_Scope) or else
Is_Task_Type (E_Scope)
Install_Private_Declarations (E_Scope);
end if;
-- If the entity is in an outer scope, then that scope needs to
-- temporarily become the current scope so that operations created
-- during type freezing will be declared in the right scope and
-- can properly override any corresponding inherited operations.
elsif In_Outer_Scope then
New_Scope (E_Scope);
end if;
-- If type, freeze the type
if Is_Type (E) then
Freeze_Type (N);
-- And for enumeration type, build the enumeration tables
if Is_Enumeration_Type (E) then
Build_Enumeration_Image_Tables (E, N);
elsif Is_Tagged_Type (E)
and then Is_First_Subtype (E)
-- Check for a definition of External_Tag, whose expansion must
-- be delayed until the dispatch table is built. The clause
-- is considered only if it applies to this specific tagged
-- type, as opposed to one of its ancestors.
Def : constant Node_Id :=
(E, Attribute_External_Tag);
if Present (Def) and then Entity (Name (Def)) = E then
Expand_External_Tag_Definition (Def);
end if;
end if;
-- If subprogram, freeze the subprogram
elsif Is_Subprogram (E) then
Freeze_Subprogram (N);
end if;
-- Analyze actions generated by freezing. The init_proc contains
-- source expressions that may raise constraint_error, and the
-- assignment procedure for complex types needs checks on individual
-- component assignments, but all other freezing actions should be
-- compiled with all checks off.
if Present (Actions (N)) then
Decl := First (Actions (N));
while Present (Decl) loop
if Nkind (Decl) = N_Subprogram_Body
and then (Is_Init_Proc (Defining_Entity (Decl))
or else
Chars (Defining_Entity (Decl)) = Name_uAssign)
Analyze (Decl);
-- A subprogram body created for a renaming_as_body completes
-- a previous declaration, which may be in a different scope.
-- Establish the proper scope before analysis.
elsif Nkind (Decl) = N_Subprogram_Body
and then Present (Corresponding_Spec (Decl))
and then Scope (Corresponding_Spec (Decl)) /= Current_Scope
New_Scope (Scope (Corresponding_Spec (Decl)));
Analyze (Decl, Suppress => All_Checks);
Analyze (Decl, Suppress => All_Checks);
end if;
Next (Decl);
end loop;
end if;
if In_Other_Scope then
if Ekind (Current_Scope) = E_Package then
End_Package_Scope (E_Scope);
end if;
elsif In_Outer_Scope then
end if;
end Expand_N_Freeze_Entity;
-- Expand_N_Record_Representation_Clause --
-- The only expansion required is for the case of a mod clause present,
-- which is removed, and translated into an alignment representation
-- clause inserted immediately after the record rep clause with any
-- initial pragmas inserted at the start of the component clause list.
procedure Expand_N_Record_Representation_Clause (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Rectype : constant Entity_Id := Entity (Identifier (N));
Mod_Val : Uint;
Citems : List_Id;
Repitem : Node_Id;
AtM_Nod : Node_Id;
if Present (Mod_Clause (N)) then
Mod_Val := Expr_Value (Expression (Mod_Clause (N)));
Citems := Pragmas_Before (Mod_Clause (N));
if Present (Citems) then
Append_List_To (Citems, Component_Clauses (N));
Set_Component_Clauses (N, Citems);
end if;
AtM_Nod :=
Make_Attribute_Definition_Clause (Loc,
Name => New_Reference_To (Base_Type (Rectype), Loc),
Chars => Name_Alignment,
Expression => Make_Integer_Literal (Loc, Mod_Val));
Set_From_At_Mod (AtM_Nod);
Insert_After (N, AtM_Nod);
Set_Mod_Clause (N, Empty);
end if;
-- If the record representation clause has no components, then
-- completely remove it. Note that we also have to remove
-- ourself from the Rep Item list.
if Is_Empty_List (Component_Clauses (N)) then
if First_Rep_Item (Rectype) = N then
Set_First_Rep_Item (Rectype, Next_Rep_Item (N));
Repitem := First_Rep_Item (Rectype);
while Present (Next_Rep_Item (Repitem)) loop
if Next_Rep_Item (Repitem) = N then
Set_Next_Rep_Item (Repitem, Next_Rep_Item (N));
end if;
Next_Rep_Item (Repitem);
end loop;
end if;
Rewrite (N,
Make_Null_Statement (Loc));
end if;
end Expand_N_Record_Representation_Clause;
end Exp_Ch13;