aboutsummaryrefslogtreecommitdiff
path: root/gas/subsegs.c
blob: bdf28688bd122b464e6ecd950eaf14005e2ac8fd (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
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
/* subsegs.c - subsegments -
   Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 1997
   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 2, 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, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

/*
 * Segments & sub-segments.
 */

#include "as.h"

#include "subsegs.h"
#include "obstack.h"

frchainS *frchain_root, *frchain_now;

static struct obstack frchains;

#ifndef BFD_ASSEMBLER
#ifdef MANY_SEGMENTS
segment_info_type segment_info[SEG_MAXIMUM_ORDINAL];

#else
/* Commented in "subsegs.h". */
frchainS *data0_frchainP, *bss0_frchainP;

#endif /* MANY_SEGMENTS */
char const *const seg_name[] =
{
  "absolute",
#ifdef MANY_SEGMENTS
  "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9",
  "e10", "e11", "e12", "e13", "e14", "e15", "e16", "e17", "e18", "e19",
  "e20", "e21", "e22", "e23", "e24", "e25", "e26", "e27", "e28", "e29",
  "e30", "e31", "e32", "e33", "e34", "e35", "e36", "e37", "e38", "e39",
#else
  "text",
  "data",
  "bss",
#endif /* MANY_SEGMENTS */
  "unknown",
  "ASSEMBLER-INTERNAL-LOGIC-ERROR!",
  "expr",
  "debug",
  "transfert vector preload",
  "transfert vector postload",
  "register",
  "",
};				/* Used by error reporters, dumpers etc. */
#else /* BFD_ASSEMBLER */

/* Gas segment information for bfd_abs_section_ptr and
   bfd_und_section_ptr.  */
static segment_info_type *abs_seg_info;
static segment_info_type *und_seg_info;

#endif /* BFD_ASSEMBLER */

static void subseg_set_rest PARAMS ((segT, subsegT));

static fragS dummy_frag;

static frchainS absolute_frchain;

void
subsegs_begin ()
{
  /* Check table(s) seg_name[], seg_N_TYPE[] is in correct order */
#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
  know (SEG_ABSOLUTE == 0);
  know (SEG_TEXT == 1);
  know (SEG_DATA == 2);
  know (SEG_BSS == 3);
  know (SEG_UNKNOWN == 4);
  know (SEG_GOOF == 5);
  know (SEG_EXPR == 6);
  know (SEG_DEBUG == 7);
  know (SEG_NTV == 8);
  know (SEG_PTV == 9);
  know (SEG_REGISTER == 10);
  know (SEG_MAXIMUM_ORDINAL == SEG_REGISTER);
#endif

  obstack_begin (&frchains, chunksize);
#if __GNUC__ >= 2
  obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1;
#endif

  frchain_root = NULL;
  frchain_now = NULL;		/* Warn new_subseg() that we are booting. */

  frag_now = &dummy_frag;

#ifndef BFD_ASSEMBLER
  now_subseg = 42;		/* Lie for 1st call to subseg_new. */
#ifdef MANY_SEGMENTS
  {
    int i;
    for (i = SEG_E0; i < SEG_UNKNOWN; i++)
      {
	subseg_set (i, 0);
	segment_info[i].frchainP = frchain_now;
      }
  }
#else
  subseg_set (SEG_DATA, 0);	/* .data 0 */
  data0_frchainP = frchain_now;

  subseg_set (SEG_BSS, 0);
  bss0_frchainP = frchain_now;

#endif /* ! MANY_SEGMENTS */
#endif /* ! BFD_ASSEMBLER */

  absolute_frchain.frch_seg = absolute_section;
  absolute_frchain.frch_subseg = 0;
#ifdef BFD_ASSEMBLER
  absolute_frchain.fix_root = absolute_frchain.fix_tail = 0;
#endif
  absolute_frchain.frch_frag_now = &zero_address_frag;
  absolute_frchain.frch_root = absolute_frchain.frch_last = &zero_address_frag;
}

/*
 *			subseg_change()
 *
 * Change the subsegment we are in, BUT DO NOT MAKE A NEW FRAG for the
 * subsegment. If we are already in the correct subsegment, change nothing.
 * This is used eg as a worker for subseg_set [which does make a new frag_now]
 * and for changing segments after we have read the source. We construct eg
 * fixSs even after the source file is read, so we do have to keep the
 * segment context correct.
 */
void
subseg_change (seg, subseg)
     register segT seg;
     register int subseg;
{
  now_seg = seg;
  now_subseg = subseg;

  if (now_seg == absolute_section)
    return;

#ifdef BFD_ASSEMBLER
  {
    segment_info_type *seginfo;
    seginfo = (segment_info_type *) bfd_get_section_userdata (stdoutput, seg);
    if (! seginfo)
      {
	seginfo = (segment_info_type *) xmalloc (sizeof (*seginfo));
	memset ((PTR) seginfo, 0, sizeof (*seginfo));
	seginfo->fix_root = NULL;
	seginfo->fix_tail = NULL;
	seginfo->bfd_section = seg;
	seginfo->sym = 0;
	if (seg == bfd_abs_section_ptr)
	  abs_seg_info = seginfo;
	else if (seg == bfd_und_section_ptr)
	  und_seg_info = seginfo;
	else
	  bfd_set_section_userdata (stdoutput, seg, (PTR) seginfo);
      }
  }
#else
#ifdef MANY_SEGMENTS
  seg_fix_rootP = &segment_info[seg].fix_root;
  seg_fix_tailP = &segment_info[seg].fix_tail;
#else
  if (seg == SEG_DATA)
    {
      seg_fix_rootP = &data_fix_root;
      seg_fix_tailP = &data_fix_tail;
    }
  else if (seg == SEG_TEXT)
    {
      seg_fix_rootP = &text_fix_root;
      seg_fix_tailP = &text_fix_tail;
    }
  else
    {
      know (seg == SEG_BSS);
      seg_fix_rootP = &bss_fix_root;
      seg_fix_tailP = &bss_fix_tail;
    }

#endif
#endif
}

static void
subseg_set_rest (seg, subseg)
     segT seg;
     subsegT subseg;
{
  register frchainS *frcP;	/* crawl frchain chain */
  register frchainS **lastPP;	/* address of last pointer */
  frchainS *newP;		/* address of new frchain */

  mri_common_symbol = NULL;

  if (frag_now && frchain_now)
    frchain_now->frch_frag_now = frag_now;

  assert (frchain_now == 0
	  || now_seg == undefined_section
	  || now_seg == absolute_section
	  || frchain_now->frch_last == frag_now);

  subseg_change (seg, (int) subseg);

  if (seg == absolute_section)
    {
      frchain_now = &absolute_frchain;
      frag_now = &zero_address_frag;
      return;
    }

  assert (frchain_now == 0
	  || now_seg == undefined_section
	  || frchain_now->frch_last == frag_now);

  /*
   * Attempt to find or make a frchain for that sub seg.
   * Crawl along chain of frchainSs, begins @ frchain_root.
   * If we need to make a frchainS, link it into correct
   * position of chain rooted in frchain_root.
   */
  for (frcP = *(lastPP = &frchain_root);
       frcP && frcP->frch_seg <= seg;
       frcP = *(lastPP = &frcP->frch_next))
    {
      if (frcP->frch_seg == seg
	  && frcP->frch_subseg >= subseg)
	{
	  break;
	}
    }
  /*
   * frcP:		Address of the 1st frchainS in correct segment with
   *		frch_subseg >= subseg.
   *		We want to either use this frchainS, or we want
   *		to insert a new frchainS just before it.
   *
   *		If frcP==NULL, then we are at the end of the chain
   *		of frchainS-s. A NULL frcP means we fell off the end
   *		of the chain looking for a
   *		frch_subseg >= subseg, so we
   *		must make a new frchainS.
   *
   *		If we ever maintain a pointer to
   *		the last frchainS in the chain, we change that pointer
   *		ONLY when frcP==NULL.
   *
   * lastPP:	Address of the pointer with value frcP;
   *		Never NULL.
   *		May point to frchain_root.
   *
   */
  if (!frcP
      || (frcP->frch_seg > seg
	  || frcP->frch_subseg > subseg))	/* Kinky logic only works with 2 segments. */
    {
      /*
       * This should be the only code that creates a frchainS.
       */
      newP = (frchainS *) obstack_alloc (&frchains, sizeof (frchainS));
      newP->frch_subseg = subseg;
      newP->frch_seg = seg;
#ifdef BFD_ASSEMBLER
      newP->fix_root = NULL;
      newP->fix_tail = NULL;
#endif
      obstack_begin (&newP->frch_obstack, chunksize);
#if __GNUC__ >= 2
      obstack_alignment_mask (&newP->frch_obstack) = __alignof__ (fragS) - 1;
#endif
      newP->frch_frag_now = frag_alloc (&newP->frch_obstack);
      newP->frch_frag_now->fr_type = rs_fill;

      newP->frch_root = newP->frch_last = newP->frch_frag_now;

      *lastPP = newP;
      newP->frch_next = frcP;	/* perhaps NULL */

#ifdef BFD_ASSEMBLER
      {
	segment_info_type *seginfo;
	seginfo = seg_info (seg);
	if (seginfo && seginfo->frchainP == frcP)
	  seginfo->frchainP = newP;
      }
#endif
      
      frcP = newP;
    }
  /*
   * Here with frcP pointing to the frchainS for subseg.
   */
  frchain_now = frcP;
  frag_now = frcP->frch_frag_now;

  assert (frchain_now->frch_last == frag_now);
}

/*
 *			subseg_set(segT, subsegT)
 *
 * If you attempt to change to the current subsegment, nothing happens.
 *
 * In:	segT, subsegT code for new subsegment.
 *	frag_now -> incomplete frag for current subsegment.
 *	If frag_now==NULL, then there is no old, incomplete frag, so
 *	the old frag is not closed off.
 *
 * Out:	now_subseg, now_seg updated.
 *	Frchain_now points to the (possibly new) struct frchain for this
 *	sub-segment.
 *	Frchain_root updated if needed.
 */

#ifndef BFD_ASSEMBLER

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  int i;

  for (i = 0; i < (int) SEG_MAXIMUM_ORDINAL; i++)
    {
      const char *s;

      s = segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#ifdef obj_segment_name
      s = obj_segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#endif
    }

#ifdef obj_add_segment
  {
    segT new_seg;
    new_seg = obj_add_segment (segname);
    subseg_set (new_seg, subseg);
    return new_seg;
  }
#else
  as_bad (_("Attempt to switch to nonexistent segment \"%s\""), segname);
  return now_seg;
#endif
}

void
subseg_set (seg, subseg)	/* begin assembly for a new sub-segment */
     register segT seg;		/* SEG_DATA or SEG_TEXT */
     register subsegT subseg;
{
#ifndef MANY_SEGMENTS
  know (seg == SEG_DATA
	|| seg == SEG_TEXT
	|| seg == SEG_BSS
	|| seg == SEG_ABSOLUTE);
#endif

  if (seg != now_seg || subseg != now_subseg)
    {				/* we just changed sub-segments */
      subseg_set_rest (seg, subseg);
    }
  mri_common_symbol = NULL;
}

#else /* BFD_ASSEMBLER */

segT
subseg_get (segname, force_new)
     const char *segname;
     int force_new;
{
  segT secptr;
  segment_info_type *seginfo;
  const char *now_seg_name = (now_seg
			      ? bfd_get_section_name (stdoutput, now_seg)
			      : 0);

  if (!force_new
      && now_seg_name
      && (now_seg_name == segname
	  || !strcmp (now_seg_name, segname)))
    return now_seg;

  if (!force_new)
    secptr = bfd_make_section_old_way (stdoutput, segname);
  else
    secptr = bfd_make_section_anyway (stdoutput, segname);

  seginfo = seg_info (secptr);
  if (! seginfo)
    {
      /* Check whether output_section is set first because secptr may
         be bfd_abs_section_ptr.  */
      if (secptr->output_section != secptr)
	secptr->output_section = secptr;
      seginfo = (segment_info_type *) xmalloc (sizeof (*seginfo));
      memset ((PTR) seginfo, 0, sizeof (*seginfo));
      seginfo->fix_root = NULL;
      seginfo->fix_tail = NULL;
      seginfo->bfd_section = secptr;
      if (secptr == bfd_abs_section_ptr)
	abs_seg_info = seginfo;
      else if (secptr == bfd_und_section_ptr)
	und_seg_info = seginfo;
      else
	bfd_set_section_userdata (stdoutput, secptr, (PTR) seginfo);
      seginfo->frchainP = NULL;
      seginfo->lineno_list_head = seginfo->lineno_list_tail = NULL;
      seginfo->sym = NULL;
      seginfo->dot = NULL;
    }
  return secptr;
}

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 0);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

/* Like subseg_new, except a new section is always created, even if
   a section with that name already exists.  */
segT
subseg_force_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 1);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

void
subseg_set (secptr, subseg)
     segT secptr;
     subsegT subseg;
{
  if (! (secptr == now_seg && subseg == now_subseg))
    subseg_set_rest (secptr, subseg);
  mri_common_symbol = NULL;
}

#ifndef obj_sec_sym_ok_for_reloc
#define obj_sec_sym_ok_for_reloc(SEC)	0
#endif

/* Get the gas information we are storing for a section.  */

segment_info_type *
seg_info (sec)
     segT sec;
{
  if (sec == bfd_abs_section_ptr)
    return abs_seg_info;
  else if (sec == bfd_und_section_ptr)
    return und_seg_info;
  else
    return (segment_info_type *) bfd_get_section_userdata (stdoutput, sec);
}

symbolS *
section_symbol (sec)
     segT sec;
{
  segment_info_type *seginfo = seg_info (sec);
  symbolS *s;

  if (seginfo == 0)
    abort ();
  if (seginfo->sym)
    return seginfo->sym;

#ifndef EMIT_SECTION_SYMBOLS
#define EMIT_SECTION_SYMBOLS 1
#endif

  if (! EMIT_SECTION_SYMBOLS
#ifdef BFD_ASSEMBLER
      || symbol_table_frozen
#endif
      )
    {
      /* Here we know it won't be going into the symbol table.  */
      s = symbol_create (sec->name, sec, 0, &zero_address_frag);
    }
  else
    {
      s = symbol_find_base (sec->name, 0);
      if (s == NULL)
	s = symbol_new (sec->name, sec, 0, &zero_address_frag);
      else
	{
	  if (S_GET_SEGMENT (s) == undefined_section)
	    {
	      S_SET_SEGMENT (s, sec);
	      s->sy_frag = &zero_address_frag;
	    }
	}
    }

  S_CLEAR_EXTERNAL (s);

  /* Use the BFD section symbol, if possible.  */
  if (obj_sec_sym_ok_for_reloc (sec))
    s->bsym = sec->symbol;

  seginfo->sym = s;
  return s;
}

#endif /* BFD_ASSEMBLER */

void
subsegs_print_statistics (file)
     FILE *file;
{
  frchainS *frchp;
  fprintf (file, "frag chains:\n");
  for (frchp = frchain_root; frchp; frchp = frchp->frch_next)
    {
      int count = 0;
      fragS *fragp;

      /* If frch_subseg is non-zero, it's probably been chained onto
	 the end of a previous subsection.  Don't count it again.  */
      if (frchp->frch_subseg != 0)
	continue;

      /* Skip gas-internal sections.  */
      if (segment_name (frchp->frch_seg)[0] == '*')
	continue;

      for (fragp = frchp->frch_root; fragp; fragp = fragp->fr_next)
	{
#if 0
	  switch (fragp->fr_type)
	    {
	    case rs_fill:
	      fprintf (file, "f"); break;
	    case rs_align:
	      fprintf (file, "a"); break;
	    case rs_align_code:
	      fprintf (file, "c"); break;
	    case rs_org:
	      fprintf (file, "o"); break;
	    case rs_machine_dependent:
	      fprintf (file, "m"); break;
	    case rs_space:
	      fprintf (file, "s"); break;
	    case 0:
	      fprintf (file, "0"); break;
	    default:
	      fprintf (file, "?"); break;
	    }
#endif
	  count++;
	}
      fprintf (file, "\n");
      fprintf (file, "\t%p %-10s\t%10d frags\n", frchp,
	       segment_name (frchp->frch_seg), count);
    }
}

/* end of subsegs.c */