aboutsummaryrefslogtreecommitdiff
path: root/gas/cond.c
blob: 71680a5abcad2e89cfa9d5ff5db29e75cf0d415c (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
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
/* cond.c - conditional assembly pseudo-ops, and .include
   Copyright (C) 1990-2018 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GAS is distributed in the hope that it will be useful,
   but WITHOUT 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
   along with GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

#include "as.h"
#include "sb.h"
#include "macro.h"

#include "obstack.h"

/* This is allocated to grow and shrink as .ifdef/.endif pairs are
   scanned.  */
struct obstack cond_obstack;

struct file_line
{
  const char *file;
  unsigned int line;
};

/* We push one of these structures for each .if, and pop it at the
   .endif.  */

struct conditional_frame
{
  /* The source file & line number of the "if".  */
  struct file_line if_file_line;
  /* The source file & line of the "else".  */
  struct file_line else_file_line;
  /* The previous conditional.  */
  struct conditional_frame *previous_cframe;
  /* Have we seen an else yet?  */
  int else_seen;
  /* Whether we are currently ignoring input.  */
  int ignoring;
  /* Whether a conditional at a higher level is ignoring input.
     Set also when a branch of an "if .. elseif .." tree has matched
     to prevent further matches.  */
  int dead_tree;
  /* Macro nesting level at which this conditional was created.  */
  int macro_nest;
};

static void initialize_cframe (struct conditional_frame *cframe);
static char *get_mri_string (int, int *);

static struct conditional_frame *current_cframe = NULL;

/* Performs the .ifdef (test_defined == 1) and
   the .ifndef (test_defined == 0) pseudo op.  */

void
s_ifdef (int test_defined)
{
  /* Points to name of symbol.  */
  char *name;
  /* Points to symbol.  */
  symbolS *symbolP;
  struct conditional_frame cframe;
  char c;

  /* Leading whitespace is part of operand.  */
  SKIP_WHITESPACE ();
  name = input_line_pointer;

  if (!is_name_beginner (*name) && *name != '"')
    {
      as_bad (_("invalid identifier for \".ifdef\""));
      obstack_1grow (&cond_obstack, 0);
      ignore_rest_of_line ();
      return;
    }

  c = get_symbol_name (& name);
  symbolP = symbol_find (name);
  (void) restore_line_pointer (c);

  initialize_cframe (&cframe);

  if (cframe.dead_tree)
    cframe.ignoring = 1;
  else
    {
      int is_defined;

      /* Use the same definition of 'defined' as .equiv so that a symbol
	 which has been referenced but not yet given a value/address is
	 considered to be undefined.  */
      is_defined =
	symbolP != NULL
	&& (S_IS_DEFINED (symbolP) || symbol_equated_p (symbolP))
	&& S_GET_SEGMENT (symbolP) != reg_section;

      cframe.ignoring = ! (test_defined ^ is_defined);
    }

  current_cframe =
    (struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
  memcpy (current_cframe, &cframe, sizeof cframe);

  if (LISTING_SKIP_COND ()
      && cframe.ignoring
      && (cframe.previous_cframe == NULL
	  || ! cframe.previous_cframe->ignoring))
    listing_list (2);

  demand_empty_rest_of_line ();
}

void
s_if (int arg)
{
  expressionS operand;
  struct conditional_frame cframe;
  int t;
  char *stop = NULL;
  char stopc = 0;

  if (flag_mri)
    stop = mri_comment_field (&stopc);

  /* Leading whitespace is part of operand.  */
  SKIP_WHITESPACE ();

  if (current_cframe != NULL && current_cframe->ignoring)
    {
      operand.X_add_number = 0;
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;
    }
  else
    {
      expression_and_evaluate (&operand);
      if (operand.X_op != O_constant)
	as_bad (_("non-constant expression in \".if\" statement"));
    }

  switch ((operatorT) arg)
    {
    case O_eq: t = operand.X_add_number == 0; break;
    case O_ne: t = operand.X_add_number != 0; break;
    case O_lt: t = operand.X_add_number < 0; break;
    case O_le: t = operand.X_add_number <= 0; break;
    case O_ge: t = operand.X_add_number >= 0; break;
    case O_gt: t = operand.X_add_number > 0; break;
    default:
      abort ();
      return;
    }

  /* If the above error is signaled, this will dispatch
     using an undefined result.  No big deal.  */
  initialize_cframe (&cframe);
  cframe.ignoring = cframe.dead_tree || ! t;
  current_cframe =
    (struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
  memcpy (current_cframe, & cframe, sizeof cframe);

  if (LISTING_SKIP_COND ()
      && cframe.ignoring
      && (cframe.previous_cframe == NULL
	  || ! cframe.previous_cframe->ignoring))
    listing_list (2);

  if (flag_mri)
    mri_comment_end (stop, stopc);

  demand_empty_rest_of_line ();
}

/* Performs the .ifb (test_blank == 1) and
   the .ifnb (test_blank == 0) pseudo op.  */

void
s_ifb (int test_blank)
{
  struct conditional_frame cframe;

  initialize_cframe (&cframe);

  if (cframe.dead_tree)
    cframe.ignoring = 1;
  else
    {
      int is_eol;

      SKIP_WHITESPACE ();
      is_eol = is_end_of_line[(unsigned char) *input_line_pointer];
      cframe.ignoring = (test_blank == !is_eol);
    }

  current_cframe =
    (struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
  memcpy (current_cframe, &cframe, sizeof cframe);

  if (LISTING_SKIP_COND ()
      && cframe.ignoring
      && (cframe.previous_cframe == NULL
	  || ! cframe.previous_cframe->ignoring))
    listing_list (2);

  ignore_rest_of_line ();
}

/* Get a string for the MRI IFC or IFNC pseudo-ops.  */

static char *
get_mri_string (int terminator, int *len)
{
  char *ret;
  char *s;

  SKIP_WHITESPACE ();
  s = ret = input_line_pointer;
  if (*input_line_pointer == '\'')
    {
      ++s;
      ++input_line_pointer;
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	{
	  *s++ = *input_line_pointer++;
	  if (s[-1] == '\'')
	    {
	      if (*input_line_pointer != '\'')
		break;
	      ++input_line_pointer;
	    }
	}
      SKIP_WHITESPACE ();
    }
  else
    {
      while (*input_line_pointer != terminator
	     && ! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;
      s = input_line_pointer;
      while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
	--s;
    }

  *len = s - ret;
  return ret;
}

/* The MRI IFC and IFNC pseudo-ops.  */

void
s_ifc (int arg)
{
  char *stop = NULL;
  char stopc = 0;
  char *s1, *s2;
  int len1, len2;
  int res;
  struct conditional_frame cframe;

  if (flag_mri)
    stop = mri_comment_field (&stopc);

  s1 = get_mri_string (',', &len1);

  if (*input_line_pointer != ',')
    as_bad (_("bad format for ifc or ifnc"));
  else
    ++input_line_pointer;

  s2 = get_mri_string (';', &len2);

  res = len1 == len2 && strncmp (s1, s2, len1) == 0;

  initialize_cframe (&cframe);
  cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
  current_cframe =
    (struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
  memcpy (current_cframe, &cframe, sizeof cframe);
  
 if (LISTING_SKIP_COND ()
      && cframe.ignoring
      && (cframe.previous_cframe == NULL
	  || ! cframe.previous_cframe->ignoring))
    listing_list (2);

  if (flag_mri)
    mri_comment_end (stop, stopc);

  demand_empty_rest_of_line ();
}

void
s_elseif (int arg)
{
  if (current_cframe == NULL)
    {
      as_bad (_("\".elseif\" without matching \".if\""));
    }
  else if (current_cframe->else_seen)
    {
      as_bad (_("\".elseif\" after \".else\""));
      as_bad_where (current_cframe->else_file_line.file,
		    current_cframe->else_file_line.line,
		    _("here is the previous \".else\""));
      as_bad_where (current_cframe->if_file_line.file,
		    current_cframe->if_file_line.line,
		    _("here is the previous \".if\""));
    }
  else
    {
      current_cframe->else_file_line.file
       	= as_where (&current_cframe->else_file_line.line);

      current_cframe->dead_tree |= !current_cframe->ignoring;
      current_cframe->ignoring = current_cframe->dead_tree;
    }

  if (current_cframe == NULL || current_cframe->ignoring)
    {
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;

      if (current_cframe == NULL)
	return;
    }
  else
    {
      expressionS operand;
      int t;

      /* Leading whitespace is part of operand.  */
      SKIP_WHITESPACE ();

      expression_and_evaluate (&operand);
      if (operand.X_op != O_constant)
	as_bad (_("non-constant expression in \".elseif\" statement"));

      switch ((operatorT) arg)
	{
	case O_eq: t = operand.X_add_number == 0; break;
	case O_ne: t = operand.X_add_number != 0; break;
	case O_lt: t = operand.X_add_number < 0; break;
	case O_le: t = operand.X_add_number <= 0; break;
	case O_ge: t = operand.X_add_number >= 0; break;
	case O_gt: t = operand.X_add_number > 0; break;
	default:
	  abort ();
	  return;
	}

      current_cframe->ignoring = current_cframe->dead_tree || ! t;
    }

  if (LISTING_SKIP_COND ()
      && (current_cframe->previous_cframe == NULL
	  || ! current_cframe->previous_cframe->ignoring))
    {
      if (! current_cframe->ignoring)
	listing_list (1);
      else
	listing_list (2);
    }

  demand_empty_rest_of_line ();
}

void
s_endif (int arg ATTRIBUTE_UNUSED)
{
  struct conditional_frame *hold;

  if (current_cframe == NULL)
    {
      as_bad (_("\".endif\" without \".if\""));
    }
  else
    {
      if (LISTING_SKIP_COND ()
	  && current_cframe->ignoring
	  && (current_cframe->previous_cframe == NULL
	      || ! current_cframe->previous_cframe->ignoring))
	listing_list (1);

      hold = current_cframe;
      current_cframe = current_cframe->previous_cframe;
      obstack_free (&cond_obstack, hold);
    }				/* if one pop too many */

  if (flag_mri)
    {
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;
    }

  demand_empty_rest_of_line ();
}

void
s_else (int arg ATTRIBUTE_UNUSED)
{
  if (current_cframe == NULL)
    {
      as_bad (_("\".else\" without matching \".if\""));
    }
  else if (current_cframe->else_seen)
    {
      as_bad (_("duplicate \".else\""));
      as_bad_where (current_cframe->else_file_line.file,
		    current_cframe->else_file_line.line,
		    _("here is the previous \".else\""));
      as_bad_where (current_cframe->if_file_line.file,
		    current_cframe->if_file_line.line,
		    _("here is the previous \".if\""));
    }
  else
    {
      current_cframe->else_file_line.file
       	= as_where (&current_cframe->else_file_line.line);

      current_cframe->ignoring =
	current_cframe->dead_tree | !current_cframe->ignoring;

      if (LISTING_SKIP_COND ()
	  && (current_cframe->previous_cframe == NULL
	      || ! current_cframe->previous_cframe->ignoring))
	{
	  if (! current_cframe->ignoring)
	    listing_list (1);
	  else
	    listing_list (2);
	}

      current_cframe->else_seen = 1;
    }

  if (flag_mri)
    {
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;
    }

  demand_empty_rest_of_line ();
}

void
s_ifeqs (int arg)
{
  char *s1, *s2;
  int len1, len2;
  int res;
  struct conditional_frame cframe;

  s1 = demand_copy_C_string (&len1);

  SKIP_WHITESPACE ();
  if (*input_line_pointer != ',')
    {
      as_bad (_(".ifeqs syntax error"));
      ignore_rest_of_line ();
      return;
    }

  ++input_line_pointer;

  s2 = demand_copy_C_string (&len2);

  res = len1 == len2 && strncmp (s1, s2, len1) == 0;

  initialize_cframe (&cframe);
  cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
  current_cframe =
    (struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
  memcpy (current_cframe, &cframe, sizeof cframe);

  if (LISTING_SKIP_COND ()
      && cframe.ignoring
      && (cframe.previous_cframe == NULL
	  || ! cframe.previous_cframe->ignoring))
    listing_list (2);

  demand_empty_rest_of_line ();
}

int
ignore_input (void)
{
  char *s;

  s = input_line_pointer;

  if (NO_PSEUDO_DOT || flag_m68k_mri)
    {
      if (s[-1] != '.')
	--s;
    }
  else
    {
      if (s[-1] != '.')
	return (current_cframe != NULL) && (current_cframe->ignoring);
    }

  /* We cannot ignore certain pseudo ops.  */
  if (((s[0] == 'i'
	|| s[0] == 'I')
       && (!strncasecmp (s, "if", 2)
	   || !strncasecmp (s, "ifdef", 5)
	   || !strncasecmp (s, "ifndef", 6)))
      || ((s[0] == 'e'
	   || s[0] == 'E')
	  && (!strncasecmp (s, "else", 4)
	      || !strncasecmp (s, "endif", 5)
	      || !strncasecmp (s, "endc", 4))))
    return 0;

  return (current_cframe != NULL) && (current_cframe->ignoring);
}

static void
initialize_cframe (struct conditional_frame *cframe)
{
  memset (cframe, 0, sizeof (*cframe));
  cframe->if_file_line.file
	    = as_where (&cframe->if_file_line.line);
  cframe->previous_cframe = current_cframe;
  cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
  cframe->macro_nest = macro_nest;
}

/* Give an error if a conditional is unterminated inside a macro or
   the assembly as a whole.  If NEST is non negative, we are being
   called because of the end of a macro expansion.  If NEST is
   negative, we are being called at the of the input files.  */

void
cond_finish_check (int nest)
{
  if (current_cframe != NULL && current_cframe->macro_nest >= nest)
    {
      if (nest >= 0)
	as_bad (_("end of macro inside conditional"));
      else
	as_bad (_("end of file inside conditional"));

      as_bad_where (current_cframe->if_file_line.file,
		    current_cframe->if_file_line.line,
		    _("here is the start of the unterminated conditional"));
      if (current_cframe->else_seen)
	as_bad_where (current_cframe->else_file_line.file,
		      current_cframe->else_file_line.line,
		      _("here is the \"else\" of the unterminated conditional"));
    }
}

/* This function is called when we exit out of a macro.  We assume
   that any conditionals which began within the macro are correctly
   nested, and just pop them off the stack.  */

void
cond_exit_macro (int nest)
{
  while (current_cframe != NULL && current_cframe->macro_nest >= nest)
    {
      struct conditional_frame *hold;

      hold = current_cframe;
      current_cframe = current_cframe->previous_cframe;
      obstack_free (&cond_obstack, hold);
    }
}