xref: /dragonfly/contrib/binutils-2.34/bfd/stabs.c (revision 0de61e28)
1 /* Stabs in sections linking support.
2    Copyright (C) 1996-2020 Free Software Foundation, Inc.
3    Written by Ian Lance Taylor, Cygnus Support.
4 
5    This file is part of BFD, the Binary File Descriptor library.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software
19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20    MA 02110-1301, USA.  */
21 
22 
23 /* This file contains support for linking stabs in sections, as used
24    on COFF and ELF.  */
25 
26 #include "sysdep.h"
27 #include "bfd.h"
28 #include "libbfd.h"
29 #include "aout/stab_gnu.h"
30 #include "safe-ctype.h"
31 
32 /* Stabs entries use a 12 byte format:
33      4 byte string table index
34      1 byte stab type
35      1 byte stab other field
36      2 byte stab desc field
37      4 byte stab value
38    FIXME: This will have to change for a 64 bit object format.
39 
40    The stabs symbols are divided into compilation units.  For the
41    first entry in each unit, the type of 0, the value is the length of
42    the string table for this unit, and the desc field is the number of
43    stabs symbols for this unit.  */
44 
45 #define STRDXOFF  0
46 #define TYPEOFF   4
47 #define OTHEROFF  5
48 #define DESCOFF   6
49 #define VALOFF    8
50 #define STABSIZE  12
51 
52 /* A linked list of totals that we have found for a particular header
53    file.  A total is a unique identifier for a particular BINCL...EINCL
54    sequence of STABs that can be used to identify duplicate sequences.
55    It consists of three fields, 'sum_chars' which is the sum of all the
56    STABS characters; 'num_chars' which is the number of these charactes
57    and 'symb' which is a buffer of all the symbols in the sequence.  This
58    buffer is only checked as a last resort.  */
59 
60 struct stab_link_includes_totals
61 {
62   struct stab_link_includes_totals *next;
63   bfd_vma sum_chars;  /* Accumulated sum of STABS characters.  */
64   bfd_vma num_chars;  /* Number of STABS characters.  */
65   const char* symb;   /* The STABS characters themselves.  */
66 };
67 
68 /* An entry in the header file hash table.  */
69 
70 struct stab_link_includes_entry
71 {
72   struct bfd_hash_entry root;
73   /* List of totals we have found for this file.  */
74   struct stab_link_includes_totals *totals;
75 };
76 
77 /* This structure is used to hold a list of N_BINCL symbols, some of
78    which might be converted into N_EXCL symbols.  */
79 
80 struct stab_excl_list
81 {
82   /* The next symbol to convert.  */
83   struct stab_excl_list *next;
84   /* The offset to this symbol in the section contents.  */
85   bfd_size_type offset;
86   /* The value to use for the symbol.  */
87   bfd_vma val;
88   /* The type of this symbol (N_BINCL or N_EXCL).  */
89   int type;
90 };
91 
92 /* This structure is stored with each .stab section.  */
93 
94 struct stab_section_info
95 {
96   /* This is a linked list of N_BINCL symbols which should be
97      converted into N_EXCL symbols.  */
98   struct stab_excl_list *excls;
99 
100   /* This is used to map input stab offsets within their sections
101      to output stab offsets, to take into account stabs that have
102      been deleted.  If it is NULL, the output offsets are the same
103      as the input offsets, because no stabs have been deleted from
104      this section.  Otherwise the i'th entry is the number of
105      bytes of stabs that have been deleted prior to the i'th
106      stab.  */
107   bfd_size_type *cumulative_skips;
108 
109   /* This is an array of string indices.  For each stab symbol, we
110      store the string index here.  If a stab symbol should not be
111      included in the final output, the string index is -1.  */
112   bfd_size_type stridxs[1];
113 };
114 
115 
116 /* The function to create a new entry in the header file hash table.  */
117 
118 static struct bfd_hash_entry *
119 stab_link_includes_newfunc (struct bfd_hash_entry *entry,
120 			    struct bfd_hash_table *table,
121 			    const char *string)
122 {
123   struct stab_link_includes_entry *ret =
124     (struct stab_link_includes_entry *) entry;
125 
126   /* Allocate the structure if it has not already been allocated by a
127      subclass.  */
128   if (ret == NULL)
129     ret = (struct stab_link_includes_entry *)
130 	bfd_hash_allocate (table, sizeof (struct stab_link_includes_entry));
131   if (ret == NULL)
132     return NULL;
133 
134   /* Call the allocation method of the superclass.  */
135   ret = ((struct stab_link_includes_entry *)
136 	 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
137   if (ret)
138     /* Set local fields.  */
139     ret->totals = NULL;
140 
141   return (struct bfd_hash_entry *) ret;
142 }
143 
144 /* This function is called for each input file from the add_symbols
145    pass of the linker.  */
146 
147 bfd_boolean
148 _bfd_link_section_stabs (bfd *abfd,
149 			 struct stab_info *sinfo,
150 			 asection *stabsec,
151 			 asection *stabstrsec,
152 			 void * *psecinfo,
153 			 bfd_size_type *pstring_offset)
154 {
155   bfd_boolean first;
156   bfd_size_type count, amt;
157   struct stab_section_info *secinfo;
158   bfd_byte *stabbuf = NULL;
159   bfd_byte *stabstrbuf = NULL;
160   bfd_byte *sym, *symend;
161   bfd_size_type stroff, next_stroff, skip;
162   bfd_size_type *pstridx;
163 
164   if (stabsec->size == 0
165       || stabstrsec->size == 0)
166     /* This file does not contain stabs debugging information.  */
167     return TRUE;
168 
169   if (stabsec->size % STABSIZE != 0)
170     /* Something is wrong with the format of these stab symbols.
171        Don't try to optimize them.  */
172     return TRUE;
173 
174   if ((stabstrsec->flags & SEC_RELOC) != 0)
175     /* We shouldn't see relocations in the strings, and we aren't
176        prepared to handle them.  */
177     return TRUE;
178 
179   if (bfd_is_abs_section (stabsec->output_section)
180       || bfd_is_abs_section (stabstrsec->output_section))
181     /* At least one of the sections is being discarded from the
182        link, so we should just ignore them.  */
183     return TRUE;
184 
185   first = FALSE;
186 
187   if (sinfo->stabstr == NULL)
188     {
189       flagword flags;
190 
191       /* Initialize the stabs information we need to keep track of.  */
192       first = TRUE;
193       sinfo->strings = _bfd_stringtab_init ();
194       if (sinfo->strings == NULL)
195 	goto error_return;
196       /* Make sure the first byte is zero.  */
197       (void) _bfd_stringtab_add (sinfo->strings, "", TRUE, TRUE);
198       if (! bfd_hash_table_init (&sinfo->includes,
199 				 stab_link_includes_newfunc,
200 				 sizeof (struct stab_link_includes_entry)))
201 	goto error_return;
202       flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING
203 	       | SEC_LINKER_CREATED);
204       sinfo->stabstr = bfd_make_section_anyway_with_flags (abfd, ".stabstr",
205 							   flags);
206       if (sinfo->stabstr == NULL)
207 	goto error_return;
208     }
209 
210   /* Initialize the information we are going to store for this .stab
211      section.  */
212   count = stabsec->size / STABSIZE;
213 
214   amt = sizeof (struct stab_section_info);
215   amt += (count - 1) * sizeof (bfd_size_type);
216   *psecinfo = bfd_alloc (abfd, amt);
217   if (*psecinfo == NULL)
218     goto error_return;
219 
220   secinfo = (struct stab_section_info *) *psecinfo;
221   secinfo->excls = NULL;
222   stabsec->rawsize = stabsec->size;
223   secinfo->cumulative_skips = NULL;
224   memset (secinfo->stridxs, 0, (size_t) count * sizeof (bfd_size_type));
225 
226   /* Read the stabs information from abfd.  */
227   if (!bfd_malloc_and_get_section (abfd, stabsec, &stabbuf)
228       || !bfd_malloc_and_get_section (abfd, stabstrsec, &stabstrbuf))
229     goto error_return;
230 
231   /* Look through the stabs symbols, work out the new string indices,
232      and identify N_BINCL symbols which can be eliminated.  */
233   stroff = 0;
234   /* The stabs sections can be split when
235      -split-by-reloc/-split-by-file is used.  We must keep track of
236      each stab section's place in the single concatenated string
237      table.  */
238   next_stroff = pstring_offset ? *pstring_offset : 0;
239   skip = 0;
240 
241   symend = stabbuf + stabsec->size;
242   for (sym = stabbuf, pstridx = secinfo->stridxs;
243        sym < symend;
244        sym += STABSIZE, ++pstridx)
245     {
246       bfd_size_type symstroff;
247       int type;
248       const char *string;
249 
250       if (*pstridx != 0)
251 	/* This symbol has already been handled by an N_BINCL pass.  */
252 	continue;
253 
254       type = sym[TYPEOFF];
255 
256       if (type == 0)
257 	{
258 	  /* Special type 0 stabs indicate the offset to the next
259 	     string table.  We only copy the very first one.  */
260 	  stroff = next_stroff;
261 	  next_stroff += bfd_get_32 (abfd, sym + 8);
262 	  if (pstring_offset)
263 	    *pstring_offset = next_stroff;
264 	  if (! first)
265 	    {
266 	      *pstridx = (bfd_size_type) -1;
267 	      ++skip;
268 	      continue;
269 	    }
270 	  first = FALSE;
271 	}
272 
273       /* Store the string in the hash table, and record the index.  */
274       symstroff = stroff + bfd_get_32 (abfd, sym + STRDXOFF);
275       if (symstroff >= stabstrsec->size)
276 	{
277 	  _bfd_error_handler
278 	    /* xgettext:c-format */
279 	    (_("%pB(%pA+%#lx): stabs entry has invalid string index"),
280 	     abfd, stabsec, (long) (sym - stabbuf));
281 	  bfd_set_error (bfd_error_bad_value);
282 	  goto error_return;
283 	}
284       string = (char *) stabstrbuf + symstroff;
285       *pstridx = _bfd_stringtab_add (sinfo->strings, string, TRUE, TRUE);
286 
287       /* An N_BINCL symbol indicates the start of the stabs entries
288 	 for a header file.  We need to scan ahead to the next N_EINCL
289 	 symbol, ignoring nesting, adding up all the characters in the
290 	 symbol names, not including the file numbers in types (the
291 	 first number after an open parenthesis).  */
292       if (type == (int) N_BINCL)
293 	{
294 	  bfd_vma sum_chars;
295 	  bfd_vma num_chars;
296 	  bfd_vma buf_len = 0;
297 	  char * symb;
298 	  char * symb_rover;
299 	  int nest;
300 	  bfd_byte * incl_sym;
301 	  struct stab_link_includes_entry * incl_entry;
302 	  struct stab_link_includes_totals * t;
303 	  struct stab_excl_list * ne;
304 
305 	  symb = symb_rover = NULL;
306 	  sum_chars = num_chars = 0;
307 	  nest = 0;
308 
309 	  for (incl_sym = sym + STABSIZE;
310 	       incl_sym < symend;
311 	       incl_sym += STABSIZE)
312 	    {
313 	      int incl_type;
314 
315 	      incl_type = incl_sym[TYPEOFF];
316 	      if (incl_type == 0)
317 		break;
318 	      else if (incl_type == (int) N_EXCL)
319 		continue;
320 	      else if (incl_type == (int) N_EINCL)
321 		{
322 		  if (nest == 0)
323 		    break;
324 		  --nest;
325 		}
326 	      else if (incl_type == (int) N_BINCL)
327 		++nest;
328 	      else if (nest == 0)
329 		{
330 		  const char *str;
331 
332 		  str = ((char *) stabstrbuf
333 			 + stroff
334 			 + bfd_get_32 (abfd, incl_sym + STRDXOFF));
335 		  for (; *str != '\0'; str++)
336 		    {
337 		      if (num_chars >= buf_len)
338 			{
339 			  buf_len += 32 * 1024;
340 			  symb = (char *) bfd_realloc_or_free (symb, buf_len);
341 			  if (symb == NULL)
342 			    goto error_return;
343 			  symb_rover = symb + num_chars;
344 			}
345 		      * symb_rover ++ = * str;
346 		      sum_chars += *str;
347 		      num_chars ++;
348 		      if (*str == '(')
349 			{
350 			  /* Skip the file number.  */
351 			  ++str;
352 			  while (ISDIGIT (*str))
353 			    ++str;
354 			  --str;
355 			}
356 		    }
357 		}
358 	    }
359 
360 	  BFD_ASSERT (num_chars == (bfd_vma) (symb_rover - symb));
361 
362 	  /* If we have already included a header file with the same
363 	     value, then replaced this one with an N_EXCL symbol.  */
364 	  incl_entry = (struct stab_link_includes_entry * )
365 	    bfd_hash_lookup (&sinfo->includes, string, TRUE, TRUE);
366 	  if (incl_entry == NULL)
367 	    goto error_return;
368 
369 	  for (t = incl_entry->totals; t != NULL; t = t->next)
370 	    if (t->sum_chars == sum_chars
371 		&& t->num_chars == num_chars
372 		&& memcmp (t->symb, symb, num_chars) == 0)
373 	      break;
374 
375 	  /* Record this symbol, so that we can set the value
376 	     correctly.  */
377 	  amt = sizeof *ne;
378 	  ne = (struct stab_excl_list *) bfd_alloc (abfd, amt);
379 	  if (ne == NULL)
380 	    goto error_return;
381 	  ne->offset = sym - stabbuf;
382 	  ne->val = sum_chars;
383 	  ne->type = (int) N_BINCL;
384 	  ne->next = secinfo->excls;
385 	  secinfo->excls = ne;
386 
387 	  if (t == NULL)
388 	    {
389 	      /* This is the first time we have seen this header file
390 		 with this set of stabs strings.  */
391 	      t = (struct stab_link_includes_totals *)
392 		  bfd_hash_allocate (&sinfo->includes, sizeof *t);
393 	      if (t == NULL)
394 		goto error_return;
395 	      t->sum_chars = sum_chars;
396 	      t->num_chars = num_chars;
397 	      /* Trim data down.  */
398 	      t->symb = symb = (char *) bfd_realloc_or_free (symb, num_chars);
399 	      t->next = incl_entry->totals;
400 	      incl_entry->totals = t;
401 	    }
402 	  else
403 	    {
404 	      bfd_size_type *incl_pstridx;
405 
406 	      /* We have seen this header file before.  Tell the final
407 		 pass to change the type to N_EXCL.  */
408 	      ne->type = (int) N_EXCL;
409 
410 	      /* Free off superfluous symbols.  */
411 	      free (symb);
412 
413 	      /* Mark the skipped symbols.  */
414 
415 	      nest = 0;
416 	      for (incl_sym = sym + STABSIZE, incl_pstridx = pstridx + 1;
417 		   incl_sym < symend;
418 		   incl_sym += STABSIZE, ++incl_pstridx)
419 		{
420 		  int incl_type;
421 
422 		  incl_type = incl_sym[TYPEOFF];
423 
424 		  if (incl_type == (int) N_EINCL)
425 		    {
426 		      if (nest == 0)
427 			{
428 			  *incl_pstridx = (bfd_size_type) -1;
429 			  ++skip;
430 			  break;
431 			}
432 		      --nest;
433 		    }
434 		  else if (incl_type == (int) N_BINCL)
435 		    ++nest;
436 		  else if (incl_type == (int) N_EXCL)
437 		    /* Keep existing exclusion marks.  */
438 		    continue;
439 		  else if (nest == 0)
440 		    {
441 		      *incl_pstridx = (bfd_size_type) -1;
442 		      ++skip;
443 		    }
444 		}
445 	    }
446 	}
447     }
448 
449   free (stabbuf);
450   stabbuf = NULL;
451   free (stabstrbuf);
452   stabstrbuf = NULL;
453 
454   /* We need to set the section sizes such that the linker will
455      compute the output section sizes correctly.  We set the .stab
456      size to not include the entries we don't want.  We set
457      SEC_EXCLUDE for the .stabstr section, so that it will be dropped
458      from the link.  We record the size of the strtab in the first
459      .stabstr section we saw, and make sure we don't set SEC_EXCLUDE
460      for that section.  */
461   stabsec->size = (count - skip) * STABSIZE;
462   if (stabsec->size == 0)
463     stabsec->flags |= SEC_EXCLUDE | SEC_KEEP;
464   stabstrsec->flags |= SEC_EXCLUDE | SEC_KEEP;
465   sinfo->stabstr->size = _bfd_stringtab_size (sinfo->strings);
466 
467   /* Calculate the `cumulative_skips' array now that stabs have been
468      deleted for this section.  */
469 
470   if (skip != 0)
471     {
472       bfd_size_type i, offset;
473       bfd_size_type *pskips;
474 
475       amt = count * sizeof (bfd_size_type);
476       secinfo->cumulative_skips = (bfd_size_type *) bfd_alloc (abfd, amt);
477       if (secinfo->cumulative_skips == NULL)
478 	goto error_return;
479 
480       pskips = secinfo->cumulative_skips;
481       pstridx = secinfo->stridxs;
482       offset = 0;
483 
484       for (i = 0; i < count; i++, pskips++, pstridx++)
485 	{
486 	  *pskips = offset;
487 	  if (*pstridx == (bfd_size_type) -1)
488 	    offset += STABSIZE;
489 	}
490 
491       BFD_ASSERT (offset != 0);
492     }
493 
494   return TRUE;
495 
496  error_return:
497   if (stabbuf != NULL)
498     free (stabbuf);
499   if (stabstrbuf != NULL)
500     free (stabstrbuf);
501   return FALSE;
502 }
503 
504 /* This function is called for each input file before the stab
505    section is relocated.  It discards stab entries for discarded
506    functions and variables.  The function returns TRUE iff
507    any entries have been deleted.
508 */
509 
510 bfd_boolean
511 _bfd_discard_section_stabs (bfd *abfd,
512 			    asection *stabsec,
513 			    void * psecinfo,
514 			    bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
515 			    void * cookie)
516 {
517   bfd_size_type count, amt;
518   struct stab_section_info *secinfo;
519   bfd_byte *stabbuf = NULL;
520   bfd_byte *sym, *symend;
521   bfd_size_type skip;
522   bfd_size_type *pstridx;
523   int deleting;
524 
525   if (stabsec->size == 0)
526     /* This file does not contain stabs debugging information.  */
527     return FALSE;
528 
529   if (stabsec->size % STABSIZE != 0)
530     /* Something is wrong with the format of these stab symbols.
531        Don't try to optimize them.  */
532     return FALSE;
533 
534   if ((stabsec->output_section != NULL
535        && bfd_is_abs_section (stabsec->output_section)))
536     /* At least one of the sections is being discarded from the
537        link, so we should just ignore them.  */
538     return FALSE;
539 
540   /* We should have initialized our data in _bfd_link_section_stabs.
541      If there was some bizarre error reading the string sections, though,
542      we might not have.  Bail rather than asserting.  */
543   if (psecinfo == NULL)
544     return FALSE;
545 
546   count = stabsec->rawsize / STABSIZE;
547   secinfo = (struct stab_section_info *) psecinfo;
548 
549   /* Read the stabs information from abfd.  */
550   if (!bfd_malloc_and_get_section (abfd, stabsec, &stabbuf))
551     goto error_return;
552 
553   /* Look through the stabs symbols and discard any information for
554      discarded functions.  */
555   skip = 0;
556   deleting = -1;
557 
558   symend = stabbuf + stabsec->rawsize;
559   for (sym = stabbuf, pstridx = secinfo->stridxs;
560        sym < symend;
561        sym += STABSIZE, ++pstridx)
562     {
563       int type;
564 
565       if (*pstridx == (bfd_size_type) -1)
566 	/* This stab was deleted in a previous pass.  */
567 	continue;
568 
569       type = sym[TYPEOFF];
570 
571       if (type == (int) N_FUN)
572 	{
573 	  int strx = bfd_get_32 (abfd, sym + STRDXOFF);
574 
575 	  if (strx == 0)
576 	    {
577 	      if (deleting)
578 		{
579 		  skip++;
580 		  *pstridx = -1;
581 		}
582 	      deleting = -1;
583 	      continue;
584 	    }
585 	  deleting = 0;
586 	  if ((*reloc_symbol_deleted_p) (sym + VALOFF - stabbuf, cookie))
587 	    deleting = 1;
588 	}
589 
590       if (deleting == 1)
591 	{
592 	  *pstridx = -1;
593 	  skip++;
594 	}
595       else if (deleting == -1)
596 	{
597 	  /* Outside of a function.  Check for deleted variables.  */
598 	  if (type == (int) N_STSYM || type == (int) N_LCSYM)
599 	    if ((*reloc_symbol_deleted_p) (sym + VALOFF - stabbuf, cookie))
600 	      {
601 		*pstridx = -1;
602 		skip ++;
603 	      }
604 	  /* We should also check for N_GSYM entries which reference a
605 	     deleted global, but those are less harmful to debuggers
606 	     and would require parsing the stab strings.  */
607 	}
608     }
609 
610   free (stabbuf);
611   stabbuf = NULL;
612 
613   /* Shrink the stabsec as needed.  */
614   stabsec->size -= skip * STABSIZE;
615   if (stabsec->size == 0)
616     stabsec->flags |= SEC_EXCLUDE | SEC_KEEP;
617 
618   /* Recalculate the `cumulative_skips' array now that stabs have been
619      deleted for this section.  */
620 
621   if (skip != 0)
622     {
623       bfd_size_type i, offset;
624       bfd_size_type *pskips;
625 
626       if (secinfo->cumulative_skips == NULL)
627 	{
628 	  amt = count * sizeof (bfd_size_type);
629 	  secinfo->cumulative_skips = (bfd_size_type *) bfd_alloc (abfd, amt);
630 	  if (secinfo->cumulative_skips == NULL)
631 	    goto error_return;
632 	}
633 
634       pskips = secinfo->cumulative_skips;
635       pstridx = secinfo->stridxs;
636       offset = 0;
637 
638       for (i = 0; i < count; i++, pskips++, pstridx++)
639 	{
640 	  *pskips = offset;
641 	  if (*pstridx == (bfd_size_type) -1)
642 	    offset += STABSIZE;
643 	}
644 
645       BFD_ASSERT (offset != 0);
646     }
647 
648   return skip > 0;
649 
650  error_return:
651   if (stabbuf != NULL)
652     free (stabbuf);
653   return FALSE;
654 }
655 
656 /* Write out the stab section.  This is called with the relocated
657    contents.  */
658 
659 bfd_boolean
660 _bfd_write_section_stabs (bfd *output_bfd,
661 			  struct stab_info *sinfo,
662 			  asection *stabsec,
663 			  void * *psecinfo,
664 			  bfd_byte *contents)
665 {
666   struct stab_section_info *secinfo;
667   struct stab_excl_list *e;
668   bfd_byte *sym, *tosym, *symend;
669   bfd_size_type *pstridx;
670 
671   secinfo = (struct stab_section_info *) *psecinfo;
672 
673   if (secinfo == NULL)
674     return bfd_set_section_contents (output_bfd, stabsec->output_section,
675 				     contents, stabsec->output_offset,
676 				     stabsec->size);
677 
678   /* Handle each N_BINCL entry.  */
679   for (e = secinfo->excls; e != NULL; e = e->next)
680     {
681       bfd_byte *excl_sym;
682 
683       BFD_ASSERT (e->offset < stabsec->rawsize);
684       excl_sym = contents + e->offset;
685       bfd_put_32 (output_bfd, e->val, excl_sym + VALOFF);
686       excl_sym[TYPEOFF] = e->type;
687     }
688 
689   /* Copy over all the stabs symbols, omitting the ones we don't want,
690      and correcting the string indices for those we do want.  */
691   tosym = contents;
692   symend = contents + stabsec->rawsize;
693   for (sym = contents, pstridx = secinfo->stridxs;
694        sym < symend;
695        sym += STABSIZE, ++pstridx)
696     {
697       if (*pstridx != (bfd_size_type) -1)
698 	{
699 	  if (tosym != sym)
700 	    memcpy (tosym, sym, STABSIZE);
701 	  bfd_put_32 (output_bfd, *pstridx, tosym + STRDXOFF);
702 
703 	  if (sym[TYPEOFF] == 0)
704 	    {
705 	      /* This is the header symbol for the stabs section.  We
706 		 don't really need one, since we have merged all the
707 		 input stabs sections into one, but we generate one
708 		 for the benefit of readers which expect to see one.  */
709 	      BFD_ASSERT (sym == contents);
710 	      bfd_put_32 (output_bfd, _bfd_stringtab_size (sinfo->strings),
711 			  tosym + VALOFF);
712 	      bfd_put_16 (output_bfd,
713 			  stabsec->output_section->size / STABSIZE - 1,
714 			  tosym + DESCOFF);
715 	    }
716 
717 	  tosym += STABSIZE;
718 	}
719     }
720 
721   BFD_ASSERT ((bfd_size_type) (tosym - contents) == stabsec->size);
722 
723   return bfd_set_section_contents (output_bfd, stabsec->output_section,
724 				   contents, (file_ptr) stabsec->output_offset,
725 				   stabsec->size);
726 }
727 
728 /* Write out the .stabstr section.  */
729 
730 bfd_boolean
731 _bfd_write_stab_strings (bfd *output_bfd, struct stab_info *sinfo)
732 {
733   if (bfd_is_abs_section (sinfo->stabstr->output_section))
734     /* The section was discarded from the link.  */
735     return TRUE;
736 
737   BFD_ASSERT ((sinfo->stabstr->output_offset
738 	       + _bfd_stringtab_size (sinfo->strings))
739 	      <= sinfo->stabstr->output_section->size);
740 
741   if (bfd_seek (output_bfd,
742 		(file_ptr) (sinfo->stabstr->output_section->filepos
743 			    + sinfo->stabstr->output_offset),
744 		SEEK_SET) != 0)
745     return FALSE;
746 
747   if (! _bfd_stringtab_emit (output_bfd, sinfo->strings))
748     return FALSE;
749 
750   /* We no longer need the stabs information.  */
751   _bfd_stringtab_free (sinfo->strings);
752   bfd_hash_table_free (&sinfo->includes);
753 
754   return TRUE;
755 }
756 
757 /* Adjust an address in the .stab section.  Given OFFSET within
758    STABSEC, this returns the new offset in the adjusted stab section,
759    or -1 if the address refers to a stab which has been removed.  */
760 
761 bfd_vma
762 _bfd_stab_section_offset (asection *stabsec,
763 			  void * psecinfo,
764 			  bfd_vma offset)
765 {
766   struct stab_section_info *secinfo;
767 
768   secinfo = (struct stab_section_info *) psecinfo;
769 
770   if (secinfo == NULL)
771     return offset;
772 
773   if (offset >= stabsec->rawsize)
774     return offset - stabsec->rawsize + stabsec->size;
775 
776   if (secinfo->cumulative_skips)
777     {
778       bfd_vma i;
779 
780       i = offset / STABSIZE;
781 
782       if (secinfo->stridxs [i] == (bfd_size_type) -1)
783 	return (bfd_vma) -1;
784 
785       return offset - secinfo->cumulative_skips [i];
786     }
787 
788   return offset;
789 }
790