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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Exp_Ch3; use Exp_Ch3;
31 with Exp_Ch6; use Exp_Ch6;
32 with Exp_Imgv; use Exp_Imgv;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
35 with Namet; use Namet;
36 with Nlists; use Nlists;
37 with Nmake; use Nmake;
38 with Rtsfind; use Rtsfind;
40 with Sem_Ch7; use Sem_Ch7;
41 with Sem_Ch8; use Sem_Ch8;
42 with Sem_Eval; use Sem_Eval;
43 with Sem_Util; use Sem_Util;
44 with Sinfo; use Sinfo;
45 with Snames; use Snames;
46 with Stand; use Stand;
47 with Tbuild; use Tbuild;
48 with Uintp; use Uintp;
50 package body Exp_Ch13 is
52 ------------------------------------------
53 -- Expand_N_Attribute_Definition_Clause --
54 ------------------------------------------
56 -- Expansion action depends on attribute involved
58 procedure Expand_N_Attribute_Definition_Clause (N : Node_Id) is
59 Loc : constant Source_Ptr := Sloc (N);
60 Exp : constant Node_Id := Expression (N);
65 Ent := Entity (Name (N));
68 Ent := Underlying_Type (Ent);
71 case Get_Attribute_Id (Chars (N)) is
77 when Attribute_Address =>
79 -- If there is an initialization which did not come from the
80 -- source program, then it is an artifact of our expansion, and we
81 -- suppress it. The case we are most concerned about here is the
82 -- initialization of a packed array to all false, which seems
83 -- inappropriate for variable to which an address clause is
84 -- applied. The expression may itself have been rewritten if the
85 -- type is packed array, so we need to examine whether the
86 -- original node is in the source. An exception though is the case
87 -- of an access variable which is default initialized to null, and
88 -- such initialization is retained.
90 -- Furthermore, if the initialization is the equivalent aggregate
91 -- of the type initialization procedure, it replaces an implicit
92 -- call to the init proc, and must be respected. Note that for
93 -- packed types we do not build equivalent aggregates.
96 Decl : constant Node_Id := Declaration_Node (Ent);
97 Typ : constant Entity_Id := Etype (Ent);
100 if Nkind (Decl) = N_Object_Declaration
101 and then Present (Expression (Decl))
102 and then Nkind (Expression (Decl)) /= N_Null
104 not Comes_From_Source (Original_Node (Expression (Decl)))
106 if Present (Base_Init_Proc (Typ))
108 Present (Static_Initialization (Base_Init_Proc (Typ)))
112 Set_Expression (Decl, Empty);
121 when Attribute_Alignment =>
123 -- As required by Gigi, we guarantee that the operand is an
124 -- integer literal (this simplifies things in Gigi).
126 if Nkind (Exp) /= N_Integer_Literal then
128 (Exp, Make_Integer_Literal (Loc, Expr_Value (Exp)));
135 when Attribute_Storage_Size =>
137 -- If the type is a task type, then assign the value of the
138 -- storage size to the Size variable associated with the task.
139 -- task_typeZ := expression
141 if Ekind (Ent) = E_Task_Type then
143 Make_Assignment_Statement (Loc,
144 Name => New_Reference_To (Storage_Size_Variable (Ent), Loc),
146 Convert_To (RTE (RE_Size_Type), Expression (N))));
148 -- For Storage_Size for an access type, create a variable to hold
149 -- the value of the specified size with name typeV and expand an
150 -- assignment statement to initialze this value.
152 elsif Is_Access_Type (Ent) then
153 V := Make_Defining_Identifier (Loc,
154 New_External_Name (Chars (Ent), 'V'));
157 Make_Object_Declaration (Loc,
158 Defining_Identifier => V,
160 New_Reference_To (RTE (RE_Storage_Offset), Loc),
162 Convert_To (RTE (RE_Storage_Offset), Expression (N))));
164 Set_Storage_Size_Variable (Ent, Entity_Id (V));
167 -- Other attributes require no expansion
173 end Expand_N_Attribute_Definition_Clause;
175 ----------------------------
176 -- Expand_N_Freeze_Entity --
177 ----------------------------
179 procedure Expand_N_Freeze_Entity (N : Node_Id) is
180 E : constant Entity_Id := Entity (N);
183 In_Other_Scope : Boolean;
184 In_Outer_Scope : Boolean;
186 Delete : Boolean := False;
189 -- Processing for objects with address clauses
191 if Is_Object (E) and then Present (Address_Clause (E)) then
192 Apply_Address_Clause_Check (E, N);
195 -- Only other items requiring any front end action are types and
198 elsif not Is_Type (E) and then not Is_Subprogram (E) then
202 -- Here E is a type or a subprogram
204 E_Scope := Scope (E);
206 -- This is an error protection against previous errors
212 -- If we are freezing entities defined in protected types, they belong
213 -- in the enclosing scope, given that the original type has been
214 -- expanded away. The same is true for entities in task types, in
215 -- particular the parameter records of entries (Entities in bodies are
216 -- all frozen within the body). If we are in the task body, this is a
219 if Ekind (E_Scope) = E_Protected_Type
220 or else (Ekind (E_Scope) = E_Task_Type
221 and then not Has_Completion (E_Scope))
223 E_Scope := Scope (E_Scope);
227 while S /= Standard_Standard and then S /= E_Scope loop
231 In_Other_Scope := not (S = E_Scope);
232 In_Outer_Scope := (not In_Other_Scope) and then (S /= Current_Scope);
234 -- If the entity being frozen is defined in a scope that is not
235 -- currently on the scope stack, we must establish the proper
236 -- visibility before freezing the entity and related subprograms.
238 if In_Other_Scope then
239 Push_Scope (E_Scope);
240 Install_Visible_Declarations (E_Scope);
242 if Ekind (E_Scope) = E_Package or else
243 Ekind (E_Scope) = E_Generic_Package or else
244 Is_Protected_Type (E_Scope) or else
245 Is_Task_Type (E_Scope)
247 Install_Private_Declarations (E_Scope);
250 -- If the entity is in an outer scope, then that scope needs to
251 -- temporarily become the current scope so that operations created
252 -- during type freezing will be declared in the right scope and
253 -- can properly override any corresponding inherited operations.
255 elsif In_Outer_Scope then
256 Push_Scope (E_Scope);
259 -- If type, freeze the type
262 Delete := Freeze_Type (N);
264 -- And for enumeration type, build the enumeration tables
266 if Is_Enumeration_Type (E) then
267 Build_Enumeration_Image_Tables (E, N);
270 -- If subprogram, freeze the subprogram
272 elsif Is_Subprogram (E) then
273 Freeze_Subprogram (N);
275 -- Ada 2005 (AI-251): Remove the freezing node associated with the
276 -- entities internally used by the frontend to register primitives
277 -- covering abstract interfaces. The call to Freeze_Subprogram has
278 -- already expanded the code that fills the corresponding entry in
279 -- its secondary dispatch table and therefore the code generator
280 -- has nothing else to do with this freezing node.
282 Delete := Present (Abstract_Interface_Alias (E));
285 -- Analyze actions generated by freezing. The init_proc contains source
286 -- expressions that may raise Constraint_Error, and the assignment
287 -- procedure for complex types needs checks on individual component
288 -- assignments, but all other freezing actions should be compiled with
291 if Present (Actions (N)) then
292 Decl := First (Actions (N));
293 while Present (Decl) loop
294 if Nkind (Decl) = N_Subprogram_Body
295 and then (Is_Init_Proc (Defining_Entity (Decl))
297 Chars (Defining_Entity (Decl)) = Name_uAssign)
301 -- A subprogram body created for a renaming_as_body completes
302 -- a previous declaration, which may be in a different scope.
303 -- Establish the proper scope before analysis.
305 elsif Nkind (Decl) = N_Subprogram_Body
306 and then Present (Corresponding_Spec (Decl))
307 and then Scope (Corresponding_Spec (Decl)) /= Current_Scope
309 Push_Scope (Scope (Corresponding_Spec (Decl)));
310 Analyze (Decl, Suppress => All_Checks);
314 Analyze (Decl, Suppress => All_Checks);
321 -- If we are to delete this N_Freeze_Entity, do so by rewriting so that
322 -- a loop on all nodes being inserted will work propertly.
325 Rewrite (N, Make_Null_Statement (Sloc (N)));
328 if In_Other_Scope then
329 if Ekind (Current_Scope) = E_Package then
330 End_Package_Scope (E_Scope);
335 elsif In_Outer_Scope then
338 end Expand_N_Freeze_Entity;
340 -------------------------------------------
341 -- Expand_N_Record_Representation_Clause --
342 -------------------------------------------
344 -- The only expansion required is for the case of a mod clause present,
345 -- which is removed, and translated into an alignment representation
346 -- clause inserted immediately after the record rep clause with any
347 -- initial pragmas inserted at the start of the component clause list.
349 procedure Expand_N_Record_Representation_Clause (N : Node_Id) is
350 Loc : constant Source_Ptr := Sloc (N);
351 Rectype : constant Entity_Id := Entity (Identifier (N));
358 if Present (Mod_Clause (N)) then
359 Mod_Val := Expr_Value (Expression (Mod_Clause (N)));
360 Citems := Pragmas_Before (Mod_Clause (N));
362 if Present (Citems) then
363 Append_List_To (Citems, Component_Clauses (N));
364 Set_Component_Clauses (N, Citems);
368 Make_Attribute_Definition_Clause (Loc,
369 Name => New_Reference_To (Base_Type (Rectype), Loc),
370 Chars => Name_Alignment,
371 Expression => Make_Integer_Literal (Loc, Mod_Val));
373 Set_From_At_Mod (AtM_Nod);
374 Insert_After (N, AtM_Nod);
375 Set_Mod_Clause (N, Empty);
378 -- If the record representation clause has no components, then
379 -- completely remove it. Note that we also have to remove
380 -- ourself from the Rep Item list.
382 if Is_Empty_List (Component_Clauses (N)) then
383 if First_Rep_Item (Rectype) = N then
384 Set_First_Rep_Item (Rectype, Next_Rep_Item (N));
386 Repitem := First_Rep_Item (Rectype);
387 while Present (Next_Rep_Item (Repitem)) loop
388 if Next_Rep_Item (Repitem) = N then
389 Set_Next_Rep_Item (Repitem, Next_Rep_Item (N));
393 Next_Rep_Item (Repitem);
398 Make_Null_Statement (Loc));
400 end Expand_N_Record_Representation_Clause;