1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Exp_Ch3; use Exp_Ch3;
30 with Exp_Ch6; use Exp_Ch6;
31 with Exp_Imgv; use Exp_Imgv;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
37 with Rtsfind; use Rtsfind;
39 with Sem_Ch7; use Sem_Ch7;
40 with Sem_Ch8; use Sem_Ch8;
41 with Sem_Eval; use Sem_Eval;
42 with Sem_Util; use Sem_Util;
43 with Sinfo; use Sinfo;
44 with Snames; use Snames;
45 with Stand; use Stand;
46 with Tbuild; use Tbuild;
47 with Uintp; use Uintp;
49 package body Exp_Ch13 is
51 ------------------------------------------
52 -- Expand_N_Attribute_Definition_Clause --
53 ------------------------------------------
55 -- Expansion action depends on attribute involved
57 procedure Expand_N_Attribute_Definition_Clause (N : Node_Id) is
58 Loc : constant Source_Ptr := Sloc (N);
59 Exp : constant Node_Id := Expression (N);
64 Ent := Entity (Name (N));
67 Ent := Underlying_Type (Ent);
70 case Get_Attribute_Id (Chars (N)) is
76 when Attribute_Address =>
78 -- If there is an initialization which did not come from the
79 -- source program, then it is an artifact of our expansion, and we
80 -- suppress it. The case we are most concerned about here is the
81 -- initialization of a packed array to all false, which seems
82 -- inappropriate for variable to which an address clause is
83 -- applied. The expression may itself have been rewritten if the
84 -- type is packed array, so we need to examine whether the
85 -- original node is in the source. An exception though is the case
86 -- of an access variable which is default initialized to null, and
87 -- such initialization is retained.
89 -- Furthermore, if the initialization is the equivalent aggregate
90 -- of the type initialization procedure, it replaces an implicit
91 -- call to the init proc, and must be respected. Note that for
92 -- packed types we do not build equivalent aggregates.
95 Decl : constant Node_Id := Declaration_Node (Ent);
96 Typ : constant Entity_Id := Etype (Ent);
98 if Nkind (Decl) = N_Object_Declaration
99 and then Present (Expression (Decl))
100 and then Nkind (Expression (Decl)) /= N_Null
102 not Comes_From_Source (Original_Node (Expression (Decl)))
104 if Present (Base_Init_Proc (Typ))
106 Present (Static_Initialization (Base_Init_Proc (Typ)))
110 Set_Expression (Decl, Empty);
119 when Attribute_Alignment =>
121 -- As required by Gigi, we guarantee that the operand is an
122 -- integer literal (this simplifies things in Gigi).
124 if Nkind (Exp) /= N_Integer_Literal then
126 (Exp, Make_Integer_Literal (Loc, Expr_Value (Exp)));
133 when Attribute_Storage_Size =>
135 -- If the type is a task type, then assign the value of the
136 -- storage size to the Size variable associated with the task.
137 -- task_typeZ := expression
139 if Ekind (Ent) = E_Task_Type then
141 Make_Assignment_Statement (Loc,
142 Name => New_Reference_To (Storage_Size_Variable (Ent), Loc),
144 Convert_To (RTE (RE_Size_Type), Expression (N))));
146 -- For Storage_Size for an access type, create a variable to hold
147 -- the value of the specified size with name typeV and expand an
148 -- assignment statement to initialze this value.
150 elsif Is_Access_Type (Ent) then
151 V := Make_Defining_Identifier (Loc,
152 New_External_Name (Chars (Ent), 'V'));
155 Make_Object_Declaration (Loc,
156 Defining_Identifier => V,
158 New_Reference_To (RTE (RE_Storage_Offset), Loc),
160 Convert_To (RTE (RE_Storage_Offset), Expression (N))));
162 Set_Storage_Size_Variable (Ent, Entity_Id (V));
165 -- Other attributes require no expansion
171 end Expand_N_Attribute_Definition_Clause;
173 ----------------------------
174 -- Expand_N_Freeze_Entity --
175 ----------------------------
177 procedure Expand_N_Freeze_Entity (N : Node_Id) is
178 E : constant Entity_Id := Entity (N);
181 In_Other_Scope : Boolean;
182 In_Outer_Scope : Boolean;
184 Delete : Boolean := False;
187 -- Processing for objects with address clauses
189 if Is_Object (E) and then Present (Address_Clause (E)) then
190 Apply_Address_Clause_Check (E, N);
193 -- Only other items requiring any front end action are types and
196 elsif not Is_Type (E) and then not Is_Subprogram (E) then
200 -- Here E is a type or a subprogram
202 E_Scope := Scope (E);
204 -- This is an error protection against previous errors
210 -- If we are freezing entities defined in protected types, they belong
211 -- in the enclosing scope, given that the original type has been
212 -- expanded away. The same is true for entities in task types, in
213 -- particular the parameter records of entries (Entities in bodies are
214 -- all frozen within the body). If we are in the task body, this is a
217 if Ekind (E_Scope) = E_Protected_Type
218 or else (Ekind (E_Scope) = E_Task_Type
219 and then not Has_Completion (E_Scope))
221 E_Scope := Scope (E_Scope);
225 while S /= Standard_Standard and then S /= E_Scope loop
229 In_Other_Scope := not (S = E_Scope);
230 In_Outer_Scope := (not In_Other_Scope) and then (S /= Current_Scope);
232 -- If the entity being frozen is defined in a scope that is not
233 -- currently on the scope stack, we must establish the proper
234 -- visibility before freezing the entity and related subprograms.
236 if In_Other_Scope then
237 Push_Scope (E_Scope);
238 Install_Visible_Declarations (E_Scope);
240 if Ekind (E_Scope) = E_Package or else
241 Ekind (E_Scope) = E_Generic_Package or else
242 Is_Protected_Type (E_Scope) or else
243 Is_Task_Type (E_Scope)
245 Install_Private_Declarations (E_Scope);
248 -- If the entity is in an outer scope, then that scope needs to
249 -- temporarily become the current scope so that operations created
250 -- during type freezing will be declared in the right scope and
251 -- can properly override any corresponding inherited operations.
253 elsif In_Outer_Scope then
254 Push_Scope (E_Scope);
257 -- If type, freeze the type
260 Delete := Freeze_Type (N);
262 -- And for enumeration type, build the enumeration tables
264 if Is_Enumeration_Type (E) then
265 Build_Enumeration_Image_Tables (E, N);
268 -- If subprogram, freeze the subprogram
270 elsif Is_Subprogram (E) then
271 Freeze_Subprogram (N);
273 -- Ada 2005 (AI-251): Remove the freezing node associated with the
274 -- entities internally used by the frontend to register primitives
275 -- covering abstract interfaces. The call to Freeze_Subprogram has
276 -- already expanded the code that fills the corresponding entry in
277 -- its secondary dispatch table and therefore the code generator
278 -- has nothing else to do with this freezing node.
280 Delete := Present (Abstract_Interface_Alias (E));
283 -- Analyze actions generated by freezing. The init_proc contains source
284 -- expressions that may raise Constraint_Error, and the assignment
285 -- procedure for complex types needs checks on individual component
286 -- assignments, but all other freezing actions should be compiled with
289 if Present (Actions (N)) then
290 Decl := First (Actions (N));
291 while Present (Decl) loop
292 if Nkind (Decl) = N_Subprogram_Body
293 and then (Is_Init_Proc (Defining_Entity (Decl))
295 Chars (Defining_Entity (Decl)) = Name_uAssign)
299 -- A subprogram body created for a renaming_as_body completes
300 -- a previous declaration, which may be in a different scope.
301 -- Establish the proper scope before analysis.
303 elsif Nkind (Decl) = N_Subprogram_Body
304 and then Present (Corresponding_Spec (Decl))
305 and then Scope (Corresponding_Spec (Decl)) /= Current_Scope
307 Push_Scope (Scope (Corresponding_Spec (Decl)));
308 Analyze (Decl, Suppress => All_Checks);
312 Analyze (Decl, Suppress => All_Checks);
319 -- If we are to delete this N_Freeze_Entity, do so by rewriting so that
320 -- a loop on all nodes being inserted will work propertly.
323 Rewrite (N, Make_Null_Statement (Sloc (N)));
326 if In_Other_Scope then
327 if Ekind (Current_Scope) = E_Package then
328 End_Package_Scope (E_Scope);
333 elsif In_Outer_Scope then
336 end Expand_N_Freeze_Entity;
338 -------------------------------------------
339 -- Expand_N_Record_Representation_Clause --
340 -------------------------------------------
342 -- The only expansion required is for the case of a mod clause present,
343 -- which is removed, and translated into an alignment representation
344 -- clause inserted immediately after the record rep clause with any
345 -- initial pragmas inserted at the start of the component clause list.
347 procedure Expand_N_Record_Representation_Clause (N : Node_Id) is
348 Loc : constant Source_Ptr := Sloc (N);
349 Rectype : constant Entity_Id := Entity (Identifier (N));
356 if Present (Mod_Clause (N)) then
357 Mod_Val := Expr_Value (Expression (Mod_Clause (N)));
358 Citems := Pragmas_Before (Mod_Clause (N));
360 if Present (Citems) then
361 Append_List_To (Citems, Component_Clauses (N));
362 Set_Component_Clauses (N, Citems);
366 Make_Attribute_Definition_Clause (Loc,
367 Name => New_Reference_To (Base_Type (Rectype), Loc),
368 Chars => Name_Alignment,
369 Expression => Make_Integer_Literal (Loc, Mod_Val));
371 Set_From_At_Mod (AtM_Nod);
372 Insert_After (N, AtM_Nod);
373 Set_Mod_Clause (N, Empty);
376 -- If the record representation clause has no components, then
377 -- completely remove it. Note that we also have to remove
378 -- ourself from the Rep Item list.
380 if Is_Empty_List (Component_Clauses (N)) then
381 if First_Rep_Item (Rectype) = N then
382 Set_First_Rep_Item (Rectype, Next_Rep_Item (N));
384 Repitem := First_Rep_Item (Rectype);
385 while Present (Next_Rep_Item (Repitem)) loop
386 if Next_Rep_Item (Repitem) = N then
387 Set_Next_Rep_Item (Repitem, Next_Rep_Item (N));
391 Next_Rep_Item (Repitem);
396 Make_Null_Statement (Loc));
398 end Expand_N_Record_Representation_Clause;