1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Einfo; use Einfo;
32 with Exp_Ch3; use Exp_Ch3;
33 with Exp_Ch6; use Exp_Ch6;
34 with Exp_Imgv; use Exp_Imgv;
35 with Exp_Util; use Exp_Util;
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 Stringt; use Stringt;
48 with Tbuild; use Tbuild;
49 with Uintp; use Uintp;
51 package body Exp_Ch13 is
53 ------------------------------------------
54 -- Expand_N_Attribute_Definition_Clause --
55 ------------------------------------------
57 -- Expansion action depends on attribute involved
59 procedure Expand_N_Attribute_Definition_Clause (N : Node_Id) is
60 Loc : constant Source_Ptr := Sloc (N);
61 Exp : constant Node_Id := Expression (N);
66 Ent := Entity (Name (N));
69 Ent := Underlying_Type (Ent);
72 case Get_Attribute_Id (Chars (N)) is
78 when Attribute_Address =>
80 -- If there is an initialization which did not come from
81 -- the source program, then it is an artifact of our
82 -- expansion, and we suppress it. The case we are most
83 -- concerned about here is the initialization of a packed
84 -- array to all false, which seems inappropriate for a
85 -- variable to which an address clause is applied. The
86 -- expression may itself have been rewritten if the type is a
87 -- packed array, so we need to examine whether the original
88 -- node is in the source.
91 Decl : constant Node_Id := Declaration_Node (Ent);
94 if Nkind (Decl) = N_Object_Declaration
95 and then Present (Expression (Decl))
97 not Comes_From_Source (Original_Node (Expression (Decl)))
99 Set_Expression (Decl, Empty);
107 when Attribute_Alignment =>
109 -- As required by Gigi, we guarantee that the operand is an
110 -- integer literal (this simplifies things in Gigi).
112 if Nkind (Exp) /= N_Integer_Literal then
114 (Exp, Make_Integer_Literal (Loc, Expr_Value (Exp)));
121 -- For the rep clause "for x'external_tag use y" generate:
123 -- xV : constant string := y;
124 -- Set_External_Tag (x'tag, xV'Address);
125 -- Register_Tag (x'tag);
127 -- note that register_tag has been delayed up to now because
128 -- the external_tag must be set before resistering.
130 when Attribute_External_Tag => External_Tag : declare
132 Old_Val : String_Id := Strval (Expr_Value_S (Exp));
136 -- Create a new nul terminated string if it is not already
138 if String_Length (Old_Val) > 0
139 and then Get_String_Char (Old_Val, String_Length (Old_Val)) = 0
143 Start_String (Old_Val);
144 Store_String_Char (Get_Char_Code (ASCII.NUL));
145 New_Val := End_String;
149 Make_Defining_Identifier (Loc,
150 New_External_Name (Chars (Ent), 'A'));
153 Make_Object_Declaration (Loc,
154 Defining_Identifier => E,
155 Constant_Present => True,
157 New_Reference_To (Standard_String, Loc),
159 Make_String_Literal (Loc, Strval => New_Val)));
161 Insert_Actions (N, New_List (
162 Make_Procedure_Call_Statement (Loc,
163 Name => New_Reference_To (RTE (RE_Set_External_Tag), Loc),
164 Parameter_Associations => New_List (
165 Make_Attribute_Reference (Loc,
166 Attribute_Name => Name_Tag,
167 Prefix => New_Occurrence_Of (Ent, Loc)),
169 Make_Attribute_Reference (Loc,
170 Attribute_Name => Name_Address,
171 Prefix => New_Occurrence_Of (E, Loc)))),
173 Make_Procedure_Call_Statement (Loc,
174 Name => New_Reference_To (RTE (RE_Register_Tag), Loc),
175 Parameter_Associations => New_List (
176 Make_Attribute_Reference (Loc,
177 Attribute_Name => Name_Tag,
178 Prefix => New_Occurrence_Of (Ent, Loc))))));
185 when Attribute_Storage_Size =>
187 -- If the type is a task type, then assign the value of the
188 -- storage size to the Size variable associated with the task.
189 -- task_typeZ := expression
191 if Ekind (Ent) = E_Task_Type then
193 Make_Assignment_Statement (Loc,
194 Name => New_Reference_To (Storage_Size_Variable (Ent), Loc),
196 Convert_To (RTE (RE_Size_Type), Expression (N))));
198 -- For Storage_Size for an access type, create a variable to hold
199 -- the value of the specified size with name typeV and expand an
200 -- assignment statement to initialze this value.
202 elsif Is_Access_Type (Ent) then
204 V := Make_Defining_Identifier (Loc,
205 New_External_Name (Chars (Ent), 'V'));
208 Make_Object_Declaration (Loc,
209 Defining_Identifier => V,
211 New_Reference_To (RTE (RE_Storage_Offset), Loc),
213 Convert_To (RTE (RE_Storage_Offset), Expression (N))));
215 Set_Storage_Size_Variable (Ent, Entity_Id (V));
218 -- Other attributes require no expansion
225 end Expand_N_Attribute_Definition_Clause;
227 ----------------------------
228 -- Expand_N_Freeze_Entity --
229 ----------------------------
231 procedure Expand_N_Freeze_Entity (N : Node_Id) is
232 E : constant Entity_Id := Entity (N);
235 In_Other_Scope : Boolean;
236 In_Outer_Scope : Boolean;
240 -- For object, with address clause, check alignment is OK
242 if Is_Object (E) then
243 Apply_Alignment_Check (E, N);
245 -- Only other items requiring any front end action are
246 -- types and subprograms.
248 elsif not Is_Type (E) and then not Is_Subprogram (E) then
252 -- Here E is a type or a subprogram
254 E_Scope := Scope (E);
256 -- If we are freezing entities defined in protected types, they
257 -- belong in the enclosing scope, given that the original type
258 -- has been expanded away. The same is true for entities in task types,
259 -- in particular the parameter records of entries (Entities in bodies
260 -- are all frozen within the body). If we are in the task body, this
261 -- is a proper scope.
263 if Ekind (E_Scope) = E_Protected_Type
264 or else (Ekind (E_Scope) = E_Task_Type
265 and then not Has_Completion (E_Scope))
267 E_Scope := Scope (E_Scope);
271 while S /= Standard_Standard and then S /= E_Scope loop
275 In_Other_Scope := not (S = E_Scope);
276 In_Outer_Scope := (not In_Other_Scope) and then (S /= Current_Scope);
278 -- If the entity being frozen is defined in a scope that is not
279 -- currently on the scope stack, we must establish the proper
280 -- visibility before freezing the entity and related subprograms.
282 if In_Other_Scope then
284 Install_Visible_Declarations (E_Scope);
286 if Ekind (E_Scope) = E_Package or else
287 Ekind (E_Scope) = E_Generic_Package or else
288 Is_Protected_Type (E_Scope) or else
289 Is_Task_Type (E_Scope)
291 Install_Private_Declarations (E_Scope);
294 -- If the entity is in an outer scope, then that scope needs to
295 -- temporarily become the current scope so that operations created
296 -- during type freezing will be declared in the right scope and
297 -- can properly override any corresponding inherited operations.
299 elsif In_Outer_Scope then
303 -- If type, freeze the type
308 -- And for enumeration type, build the enumeration tables
310 if Is_Enumeration_Type (E) then
311 Build_Enumeration_Image_Tables (E, N);
314 -- If subprogram, freeze the subprogram
316 elsif Is_Subprogram (E) then
317 Freeze_Subprogram (N);
320 -- Analyze actions generated by freezing. The init_proc contains
321 -- source expressions that may raise constraint_error, and the
322 -- assignment procedure for complex types needs checks on individual
323 -- component assignments, but all other freezing actions should be
324 -- compiled with all checks off.
326 if Present (Actions (N)) then
327 Decl := First (Actions (N));
329 while Present (Decl) loop
331 if Nkind (Decl) = N_Subprogram_Body
332 and then (Chars (Defining_Entity (Decl)) = Name_uInit_Proc
333 or else Chars (Defining_Entity (Decl)) = Name_uAssign)
337 -- A subprogram body created for a renaming_as_body completes
338 -- a previous declaration, which may be in a different scope.
339 -- Establish the proper scope before analysis.
341 elsif Nkind (Decl) = N_Subprogram_Body
342 and then Present (Corresponding_Spec (Decl))
343 and then Scope (Corresponding_Spec (Decl)) /= Current_Scope
345 New_Scope (Scope (Corresponding_Spec (Decl)));
346 Analyze (Decl, Suppress => All_Checks);
350 Analyze (Decl, Suppress => All_Checks);
357 if In_Other_Scope then
358 if Ekind (Current_Scope) = E_Package then
359 End_Package_Scope (E_Scope);
364 elsif In_Outer_Scope then
367 end Expand_N_Freeze_Entity;
369 -------------------------------------------
370 -- Expand_N_Record_Representation_Clause --
371 -------------------------------------------
373 -- The only expansion required is for the case of a mod clause present,
374 -- which is removed, and translated into an alignment representation
375 -- clause inserted immediately after the record rep clause with any
376 -- initial pragmas inserted at the start of the component clause list.
378 procedure Expand_N_Record_Representation_Clause (N : Node_Id) is
379 Loc : constant Source_Ptr := Sloc (N);
380 Rectype : constant Entity_Id := Entity (Identifier (N));
387 if Present (Mod_Clause (N)) then
388 Mod_Val := Expr_Value (Expression (Mod_Clause (N)));
389 Citems := Pragmas_Before (Mod_Clause (N));
391 if Present (Citems) then
392 Append_List_To (Citems, Component_Clauses (N));
393 Set_Component_Clauses (N, Citems);
397 Make_Attribute_Definition_Clause (Loc,
398 Name => New_Reference_To (Base_Type (Rectype), Loc),
399 Chars => Name_Alignment,
400 Expression => Make_Integer_Literal (Loc, Mod_Val));
402 Set_From_At_Mod (AtM_Nod);
403 Insert_After (N, AtM_Nod);
404 Set_Mod_Clause (N, Empty);
407 -- If the record representation clause has no components, then
408 -- completely remove it. Note that we also have to remove
409 -- ourself from the Rep Item list.
411 if Is_Empty_List (Component_Clauses (N)) then
412 if First_Rep_Item (Rectype) = N then
413 Set_First_Rep_Item (Rectype, Next_Rep_Item (N));
415 Repitem := First_Rep_Item (Rectype);
416 while Present (Next_Rep_Item (Repitem)) loop
417 if Next_Rep_Item (Repitem) = N then
418 Set_Next_Rep_Item (Repitem, Next_Rep_Item (N));
422 Next_Rep_Item (Repitem);
427 Make_Null_Statement (Loc));
429 end Expand_N_Record_Representation_Clause;