summaryrefslogtreecommitdiff
path: root/gcc/ada/expander.adb
blob: 23d2aef834b72c5aaad54495fe18c27dd284a8ac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                             E X P A N D E R                              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2010, 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 3,  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 COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- 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 Debug_A;   use Debug_A;
with Errout;    use Errout;
with Exp_Aggr;  use Exp_Aggr;
with Exp_Attr;  use Exp_Attr;
with Exp_Ch2;   use Exp_Ch2;
with Exp_Ch3;   use Exp_Ch3;
with Exp_Ch4;   use Exp_Ch4;
with Exp_Ch5;   use Exp_Ch5;
with Exp_Ch6;   use Exp_Ch6;
with Exp_Ch7;   use Exp_Ch7;
with Exp_Ch8;   use Exp_Ch8;
with Exp_Ch9;   use Exp_Ch9;
with Exp_Ch11;  use Exp_Ch11;
with Exp_Ch12;  use Exp_Ch12;
with Exp_Ch13;  use Exp_Ch13;
with Exp_Prag;  use Exp_Prag;
with Opt;       use Opt;
with Rtsfind;   use Rtsfind;
with Sem;       use Sem;
with Sem_Ch8;   use Sem_Ch8;
with Sem_Util;  use Sem_Util;
with Sinfo;     use Sinfo;
with Table;

package body Expander is

   ----------------
   -- Local Data --
   ----------------

   --  The following table is used to save values of the Expander_Active flag
   --  when they are saved by Expander_Mode_Save_And_Set. We use an extendible
   --  table (which is a bit of overkill) because it is easier than figuring
   --  out a maximum value or bothering with range checks!

   package Expander_Flags is new Table.Table (
     Table_Component_Type => Boolean,
     Table_Index_Type     => Int,
     Table_Low_Bound      => 0,
     Table_Initial        => 32,
     Table_Increment      => 200,
     Table_Name           => "Expander_Flags");

   ------------
   -- Expand --
   ------------

   procedure Expand (N : Node_Id) is
   begin
      --  If we were analyzing a default expression (or other spec expression)
      --  the Full_Analysis flag must be off. If we are in expansion mode then
      --  we must be performing a full analysis. If we are analyzing a generic
      --  then Expansion must be off.

      pragma Assert
        (not (Full_Analysis and then In_Spec_Expression)
          and then (Full_Analysis or else not Expander_Active)
          and then not (Inside_A_Generic and then Expander_Active));

      --  There are three reasons for the Expander_Active flag to be false
      --
      --  The first is when are not generating code. In this mode the
      --  Full_Analysis flag indicates whether we are performing a complete
      --  analysis, in which case Full_Analysis = True or a pre-analysis in
      --  which case Full_Analysis = False. See the spec of Sem for more
      --  info on this.
      --
      --  The second reason for the Expander_Active flag to be False is that
      --  we are performing a pre-analysis. During pre-analysis all expansion
      --  activity is turned off to make sure nodes are semantically decorated
      --  but no extra nodes are generated. This is for instance needed for
      --  the first pass of aggregate semantic processing. Note that in this
      --  case the Full_Analysis flag is set to False because the node will
      --  subsequently be re-analyzed with expansion on (see the spec of sem).

      --  Finally, expansion is turned off in a regular compilation if there
      --  are serious errors. In that case there will be no further expansion,
      --  but one cleanup action may be required: if a transient scope was
      --  created (e.g. for a function that returns an unconstrained type) the
      --  scope may still be on the stack, and must be removed explicitly,
      --  given that the expansion actions that would normally process it will
      --  not take place. This prevents cascaded errors due to stack mismatch.

      if not Expander_Active then
         Set_Analyzed (N, Full_Analysis);

         if Serious_Errors_Detected > 0
           and then Scope_Is_Transient
         then
            Scope_Stack.Table
             (Scope_Stack.Last).Actions_To_Be_Wrapped_Before := No_List;
            Scope_Stack.Table
             (Scope_Stack.Last).Actions_To_Be_Wrapped_After  := No_List;

            Pop_Scope;
         end if;

         return;

      else
         Debug_A_Entry ("expanding  ", N);

         --  Processing depends on node kind. For full details on the expansion
         --  activity required in each case, see bodies of corresponding expand
         --  routines.

         begin
            case Nkind (N) is

               when N_Abort_Statement =>
                  Expand_N_Abort_Statement (N);

               when N_Accept_Statement =>
                  Expand_N_Accept_Statement (N);

               when N_Aggregate =>
                  Expand_N_Aggregate (N);

               when N_Allocator =>
                  Expand_N_Allocator (N);

               when N_And_Then =>
                  Expand_N_And_Then (N);

               when N_Assignment_Statement =>
                  Expand_N_Assignment_Statement (N);

               when N_Asynchronous_Select =>
                  Expand_N_Asynchronous_Select (N);

               when N_Attribute_Definition_Clause =>
                  Expand_N_Attribute_Definition_Clause (N);

               when N_Attribute_Reference =>
                  Expand_N_Attribute_Reference (N);

               when N_Block_Statement =>
                  Expand_N_Block_Statement (N);

               when N_Case_Expression =>
                  Expand_N_Case_Expression (N);

               when N_Case_Statement =>
                  Expand_N_Case_Statement (N);

               when N_Conditional_Entry_Call =>
                  Expand_N_Conditional_Entry_Call (N);

               when N_Conditional_Expression =>
                  Expand_N_Conditional_Expression (N);

               when N_Delay_Relative_Statement =>
                  Expand_N_Delay_Relative_Statement (N);

               when N_Delay_Until_Statement =>
                  Expand_N_Delay_Until_Statement (N);

               when N_Entry_Body =>
                  Expand_N_Entry_Body (N);

               when N_Entry_Call_Statement =>
                  Expand_N_Entry_Call_Statement (N);

               when N_Entry_Declaration =>
                  Expand_N_Entry_Declaration (N);

               when N_Exception_Declaration =>
                  Expand_N_Exception_Declaration (N);

               when N_Exception_Renaming_Declaration =>
                  Expand_N_Exception_Renaming_Declaration (N);

               when N_Exit_Statement =>
                  Expand_N_Exit_Statement (N);

               when N_Expanded_Name =>
                  Expand_N_Expanded_Name (N);

               when N_Explicit_Dereference =>
                  Expand_N_Explicit_Dereference (N);

               when N_Extended_Return_Statement =>
                  Expand_N_Extended_Return_Statement (N);

               when N_Extension_Aggregate =>
                  Expand_N_Extension_Aggregate (N);

               when N_Freeze_Entity =>
                  Expand_N_Freeze_Entity (N);

               when N_Full_Type_Declaration =>
                  Expand_N_Full_Type_Declaration (N);

               when N_Function_Call =>
                  Expand_N_Function_Call (N);

               when N_Generic_Instantiation =>
                  Expand_N_Generic_Instantiation (N);

               when N_Goto_Statement =>
                  Expand_N_Goto_Statement (N);

               when N_Handled_Sequence_Of_Statements =>
                  Expand_N_Handled_Sequence_Of_Statements (N);

               when N_Identifier =>
                  Expand_N_Identifier (N);

               when N_Indexed_Component =>
                  Expand_N_Indexed_Component (N);

               when N_If_Statement =>
                  Expand_N_If_Statement (N);

               when N_In =>
                  Expand_N_In (N);

               when N_Loop_Statement =>
                  Expand_N_Loop_Statement (N);

               when N_Not_In =>
                  Expand_N_Not_In (N);

               when N_Null =>
                  Expand_N_Null (N);

               when N_Object_Declaration =>
                  Expand_N_Object_Declaration (N);

               when N_Object_Renaming_Declaration =>
                  Expand_N_Object_Renaming_Declaration (N);

               when N_Op_Add =>
                  Expand_N_Op_Add (N);

               when N_Op_Abs =>
                  Expand_N_Op_Abs (N);

               when N_Op_And =>
                  Expand_N_Op_And (N);

               when N_Op_Concat =>
                  Expand_N_Op_Concat (N);

               when N_Op_Divide =>
                  Expand_N_Op_Divide (N);

               when N_Op_Eq =>
                  Expand_N_Op_Eq (N);

               when N_Op_Expon =>
                  Expand_N_Op_Expon (N);

               when N_Op_Ge =>
                  Expand_N_Op_Ge (N);

               when N_Op_Gt =>
                  Expand_N_Op_Gt (N);

               when N_Op_Le =>
                  Expand_N_Op_Le (N);

               when N_Op_Lt =>
                  Expand_N_Op_Lt (N);

               when N_Op_Minus =>
                  Expand_N_Op_Minus (N);

               when N_Op_Mod =>
                  Expand_N_Op_Mod (N);

               when N_Op_Multiply =>
                  Expand_N_Op_Multiply (N);

               when N_Op_Ne =>
                  Expand_N_Op_Ne (N);

               when N_Op_Not =>
                  Expand_N_Op_Not (N);

               when N_Op_Or =>
                  Expand_N_Op_Or (N);

               when N_Op_Plus =>
                  Expand_N_Op_Plus (N);

               when N_Op_Rem =>
                  Expand_N_Op_Rem (N);

               when N_Op_Rotate_Left =>
                  Expand_N_Op_Rotate_Left (N);

               when N_Op_Rotate_Right =>
                  Expand_N_Op_Rotate_Right (N);

               when N_Op_Shift_Left =>
                  Expand_N_Op_Shift_Left (N);

               when N_Op_Shift_Right =>
                  Expand_N_Op_Shift_Right (N);

               when N_Op_Shift_Right_Arithmetic =>
                  Expand_N_Op_Shift_Right_Arithmetic (N);

               when N_Op_Subtract =>
                  Expand_N_Op_Subtract (N);

               when N_Op_Xor =>
                  Expand_N_Op_Xor (N);

               when N_Or_Else =>
                  Expand_N_Or_Else (N);

               when N_Package_Body =>
                  Expand_N_Package_Body (N);

               when N_Package_Declaration =>
                  Expand_N_Package_Declaration (N);

               when N_Package_Renaming_Declaration =>
                  Expand_N_Package_Renaming_Declaration (N);

               when N_Subprogram_Renaming_Declaration =>
                  Expand_N_Subprogram_Renaming_Declaration (N);

               when N_Pragma =>
                  Expand_N_Pragma (N);

               when N_Procedure_Call_Statement =>
                  Expand_N_Procedure_Call_Statement (N);

               when N_Protected_Type_Declaration =>
                  Expand_N_Protected_Type_Declaration (N);

               when N_Protected_Body =>
                  Expand_N_Protected_Body (N);

               when N_Qualified_Expression =>
                  Expand_N_Qualified_Expression (N);

               when N_Quantified_Expression  =>
                  Expand_N_Quantified_Expression (N);

               when N_Raise_Statement =>
                  Expand_N_Raise_Statement (N);

               when N_Raise_Constraint_Error =>
                  Expand_N_Raise_Constraint_Error (N);

               when N_Raise_Program_Error =>
                  Expand_N_Raise_Program_Error (N);

               when N_Raise_Storage_Error =>
                  Expand_N_Raise_Storage_Error (N);

               when N_Real_Literal =>
                  Expand_N_Real_Literal (N);

               when N_Record_Representation_Clause =>
                  Expand_N_Record_Representation_Clause (N);

               when N_Requeue_Statement =>
                  Expand_N_Requeue_Statement (N);

               when N_Simple_Return_Statement =>
                  Expand_N_Simple_Return_Statement (N);

               when N_Selected_Component =>
                  Expand_N_Selected_Component (N);

               when N_Selective_Accept =>
                  Expand_N_Selective_Accept (N);

               when N_Single_Task_Declaration =>
                  Expand_N_Single_Task_Declaration (N);

               when N_Slice =>
                  Expand_N_Slice (N);

               when N_Subtype_Indication =>
                  Expand_N_Subtype_Indication (N);

               when N_Subprogram_Body =>
                  Expand_N_Subprogram_Body (N);

               when N_Subprogram_Body_Stub =>
                  Expand_N_Subprogram_Body_Stub (N);

               when N_Subprogram_Declaration =>
                  Expand_N_Subprogram_Declaration (N);

               when N_Subprogram_Info =>
                  Expand_N_Subprogram_Info (N);

               when N_Task_Body =>
                  Expand_N_Task_Body (N);

               when N_Task_Type_Declaration =>
                  Expand_N_Task_Type_Declaration (N);

               when N_Timed_Entry_Call =>
                  Expand_N_Timed_Entry_Call (N);

               when N_Type_Conversion =>
                  Expand_N_Type_Conversion (N);

               when N_Unchecked_Expression =>
                  Expand_N_Unchecked_Expression (N);

               when N_Unchecked_Type_Conversion =>
                  Expand_N_Unchecked_Type_Conversion (N);

               when N_Variant_Part =>
                  Expand_N_Variant_Part (N);

               --  For all other node kinds, no expansion activity is required

               when others => null;

            end case;

         exception
            when RE_Not_Available =>
               return;
         end;

         --  Set result as analyzed and then do a possible transient wrap. The
         --  transient wrap must be done after the Analyzed flag is set on, so
         --  that we do not get a recursive attempt to expand the node N.

         Set_Analyzed (N);

         --  Deal with transient scopes

         if Scope_Is_Transient and then N = Node_To_Be_Wrapped then

            case Nkind (N) is
               when N_Statement_Other_Than_Procedure_Call |
                    N_Procedure_Call_Statement            =>
                  Wrap_Transient_Statement (N);

               when N_Object_Declaration          |
                    N_Object_Renaming_Declaration |
                    N_Subtype_Declaration         =>
                  Wrap_Transient_Declaration (N);

               when others => Wrap_Transient_Expression (N);
            end case;
         end if;

         Debug_A_Exit ("expanding  ", N, "  (done)");
      end if;
   end Expand;

   ---------------------------
   -- Expander_Mode_Restore --
   ---------------------------

   procedure Expander_Mode_Restore is
   begin
      --  Not active (has no effect) in ASIS mode (see comments in spec of
      --  Expander_Mode_Save_And_Set).

      if ASIS_Mode then
         return;
      end if;

      --  Otherwise restore the flag

      Expander_Active := Expander_Flags.Table (Expander_Flags.Last);
      Expander_Flags.Decrement_Last;

      --  Keep expander off if serious errors detected. In this case we do not
      --  need expansion, and continued expansion may cause cascaded errors or
      --  compiler bombs.

      if Serious_Errors_Detected /= 0 then
         Expander_Active := False;
      end if;
   end Expander_Mode_Restore;

   --------------------------------
   -- Expander_Mode_Save_And_Set --
   --------------------------------

   procedure Expander_Mode_Save_And_Set (Status : Boolean) is
   begin
      --  Not active (has no effect) in ASIS mode (see comments in spec of
      --  Expander_Mode_Save_And_Set).

      if ASIS_Mode then
         return;
      end if;

      --  Otherwise save and set the flag

      Expander_Flags.Increment_Last;
      Expander_Flags.Table (Expander_Flags.Last) := Expander_Active;
      Expander_Active := Status;
   end Expander_Mode_Save_And_Set;

end Expander;