bfd/stabs.c

   1 /* Stabs in sections linking support.
   2    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   3    2006, 2007 Free Software Foundation, Inc.
   4    Written by Ian Lance Taylor, Cygnus Support.
   5
   6    This file is part of BFD, the Binary File Descriptor library.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23
  24 /* This file contains support for linking stabs in sections, as used
  25    on COFF and ELF.  */
  26
  27 #include "sysdep.h"
  28 #include "bfd.h"
  29 #include "libbfd.h"
  30 #include "aout/stab_gnu.h"
  31 #include "safe-ctype.h"
  32
  33 /* Stabs entries use a 12 byte format:
  34      4 byte string table index
  35      1 byte stab type
  36      1 byte stab other field
  37      2 byte stab desc field
  38      4 byte stab value
  39    FIXME: This will have to change for a 64 bit object format.
  40
  41    The stabs symbols are divided into compilation units.  For the
  42    first entry in each unit, the type of 0, the value is the length of
  43    the string table for this unit, and the desc field is the number of
  44    stabs symbols for this unit.  */
  45
  46 #define STRDXOFF  0
  47 #define TYPEOFF   4
  48 #define OTHEROFF  5
  49 #define DESCOFF   6
  50 #define VALOFF    8
  51 #define STABSIZE  12
  52
  53 /* A linked list of totals that we have found for a particular header
  54    file.  A total is a unique identifier for a particular BINCL...EINCL
  55    sequence of STABs that can be used to identify duplicate sequences.
  56    It consists of three fields, 'sum_chars' which is the sum of all the
  57    STABS characters; 'num_chars' which is the number of these charactes
  58    and 'symb' which is a buffer of all the symbols in the sequence.  This
  59    buffer is only checked as a last resort.  */
  60
  61 struct stab_link_includes_totals
  62 {
  63   struct stab_link_includes_totals *next;
  64   bfd_vma sum_chars;  /* Accumulated sum of STABS characters.  */
  65   bfd_vma num_chars;  /* Number of STABS characters.  */
  66   const char* symb;   /* The STABS characters themselves.  */
  67 };
  68
  69 /* An entry in the header file hash table.  */
  70
  71 struct stab_link_includes_entry
  72 {
  73   struct bfd_hash_entry root;
  74   /* List of totals we have found for this file.  */
  75   struct stab_link_includes_totals *totals;
  76 };
  77
  78 /* This structure is used to hold a list of N_BINCL symbols, some of
  79    which might be converted into N_EXCL symbols.  */
  80
  81 struct stab_excl_list
  82 {
  83   /* The next symbol to convert.  */
  84   struct stab_excl_list *next;
  85   /* The offset to this symbol in the section contents.  */
  86   bfd_size_type offset;
  87   /* The value to use for the symbol.  */
  88   bfd_vma val;
  89   /* The type of this symbol (N_BINCL or N_EXCL).  */
  90   int type;
  91 };
  92
  93 /* This structure is stored with each .stab section.  */
  94
  95 struct stab_section_info
  96 {
  97   /* This is a linked list of N_BINCL symbols which should be
  98      converted into N_EXCL symbols.  */
  99   struct stab_excl_list *excls;
 100
 101   /* This is used to map input stab offsets within their sections
 102      to output stab offsets, to take into account stabs that have
 103      been deleted.  If it is NULL, the output offsets are the same
 104      as the input offsets, because no stabs have been deleted from
 105      this section.  Otherwise the i'th entry is the number of
 106      bytes of stabs that have been deleted prior to the i'th
 107      stab.  */
 108   bfd_size_type *cumulative_skips;
 109
 110   /* This is an array of string indices.  For each stab symbol, we
 111      store the string index here.  If a stab symbol should not be
 112      included in the final output, the string index is -1.  */
 113   bfd_size_type stridxs[1];
 114 };
 115
 116 \f
 117 /* The function to create a new entry in the header file hash table.  */
 118
 119 static struct bfd_hash_entry *
 120 stab_link_includes_newfunc (struct bfd_hash_entry *entry,
 121                             struct bfd_hash_table *table,
 122                             const char *string)
 123 {
 124   struct stab_link_includes_entry *ret =
 125     (struct stab_link_includes_entry *) entry;
 126
 127   /* Allocate the structure if it has not already been allocated by a
 128      subclass.  */
 129   if (ret == NULL)
 130     ret = bfd_hash_allocate (table,
 131                              sizeof (struct stab_link_includes_entry));
 132   if (ret == NULL)
 133     return NULL;
 134
 135   /* Call the allocation method of the superclass.  */
 136   ret = ((struct stab_link_includes_entry *)
 137          bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
 138   if (ret)
 139     /* Set local fields.  */
 140     ret->totals = NULL;
 141
 142   return (struct bfd_hash_entry *) ret;
 143 }
 144 \f
 145 /* This function is called for each input file from the add_symbols
 146    pass of the linker.  */
 147
 148 bfd_boolean
 149 _bfd_link_section_stabs (bfd *abfd,
 150                          struct stab_info *sinfo,
 151                          asection *stabsec,
 152                          asection *stabstrsec,
 153                          void * *psecinfo,
 154                          bfd_size_type *pstring_offset)
 155 {
 156   bfd_boolean first;
 157   bfd_size_type count, amt;
 158   struct stab_section_info *secinfo;
 159   bfd_byte *stabbuf = NULL;
 160   bfd_byte *stabstrbuf = NULL;
 161   bfd_byte *sym, *symend;
 162   bfd_size_type stroff, next_stroff, skip;
 163   bfd_size_type *pstridx;
 164
 165   if (stabsec->size == 0
 166       || stabstrsec->size == 0)
 167     /* This file does not contain stabs debugging information.  */
 168     return TRUE;
 169
 170   if (stabsec->size % STABSIZE != 0)
 171     /* Something is wrong with the format of these stab symbols.
 172        Don't try to optimize them.  */
 173     return TRUE;
 174
 175   if ((stabstrsec->flags & SEC_RELOC) != 0)
 176     /* We shouldn't see relocations in the strings, and we aren't
 177        prepared to handle them.  */
 178     return TRUE;
 179
 180   if (bfd_is_abs_section (stabsec->output_section)
 181       || bfd_is_abs_section (stabstrsec->output_section))
 182     /* At least one of the sections is being discarded from the
 183        link, so we should just ignore them.  */
 184     return TRUE;
 185
 186   first = FALSE;
 187
 188   if (sinfo->stabstr == NULL)
 189     {
 190       flagword flags;
 191
 192       /* Initialize the stabs information we need to keep track of.  */
 193       first = TRUE;
 194       sinfo->strings = _bfd_stringtab_init ();
 195       if (sinfo->strings == NULL)
 196         goto error_return;
 197       /* Make sure the first byte is zero.  */
 198       (void) _bfd_stringtab_add (sinfo->strings, "", TRUE, TRUE);
 199       if (! bfd_hash_table_init (&sinfo->includes,
 200                                  stab_link_includes_newfunc,
 201                                  sizeof (struct stab_link_includes_entry)))
 202         goto error_return;
 203       flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING
 204                | SEC_LINKER_CREATED);
 205       sinfo->stabstr = bfd_make_section_anyway_with_flags (abfd, ".stabstr",
 206                                                            flags);
 207       if (sinfo->stabstr == NULL)
 208         goto error_return;
 209     }
 210
 211   /* Initialize the information we are going to store for this .stab
 212      section.  */
 213   count = stabsec->size / STABSIZE;
 214
 215   amt = sizeof (struct stab_section_info);
 216   amt += (count - 1) * sizeof (bfd_size_type);
 217   *psecinfo = bfd_alloc (abfd, amt);
 218   if (*psecinfo == NULL)
 219     goto error_return;
 220
 221   secinfo = (struct stab_section_info *) *psecinfo;
 222   secinfo->excls = NULL;
 223   stabsec->rawsize = stabsec->size;
 224   secinfo->cumulative_skips = NULL;
 225   memset (secinfo->stridxs, 0, (size_t) count * sizeof (bfd_size_type));
 226
 227   /* Read the stabs information from abfd.  */
 228   if (!bfd_malloc_and_get_section (abfd, stabsec, &stabbuf)
 229       || !bfd_malloc_and_get_section (abfd, stabstrsec, &stabstrbuf))
 230     goto error_return;
 231
 232   /* Look through the stabs symbols, work out the new string indices,
 233      and identify N_BINCL symbols which can be eliminated.  */
 234   stroff = 0;
 235   /* The stabs sections can be split when
 236      -split-by-reloc/-split-by-file is used.  We must keep track of
 237      each stab section's place in the single concatenated string
 238      table.  */
 239   next_stroff = pstring_offset ? *pstring_offset : 0;
 240   skip = 0;
 241
 242   symend = stabbuf + stabsec->size;
 243   for (sym = stabbuf, pstridx = secinfo->stridxs;
 244        sym < symend;
 245        sym += STABSIZE, ++pstridx)
 246     {
 247       bfd_size_type symstroff;
 248       int type;
 249       const char *string;
 250
 251       if (*pstridx != 0)
 252         /* This symbol has already been handled by an N_BINCL pass.  */
 253         continue;
 254
 255       type = sym[TYPEOFF];
 256
 257       if (type == 0)
 258         {
 259           /* Special type 0 stabs indicate the offset to the next
 260              string table.  We only copy the very first one.  */
 261           stroff = next_stroff;
 262           next_stroff += bfd_get_32 (abfd, sym + 8);
 263           if (pstring_offset)
 264             *pstring_offset = next_stroff;
 265           if (! first)
 266             {
 267               *pstridx = (bfd_size_type) -1;
 268               ++skip;
 269               continue;
 270             }
 271           first = FALSE;
 272         }
 273
 274       /* Store the string in the hash table, and record the index.  */
 275       symstroff = stroff + bfd_get_32 (abfd, sym + STRDXOFF);
 276       if (symstroff >= stabstrsec->size)
 277         {
 278           (*_bfd_error_handler)
 279             (_("%B(%A+0x%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 = 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 = 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 = bfd_hash_allocate (&sinfo->includes, sizeof *t);
 392               if (t == NULL)
 393                 goto error_return;
 394               t->sum_chars = sum_chars;
 395               t->num_chars = num_chars;
 396               t->symb = symb = bfd_realloc_or_free (symb, num_chars); /* Trim data down.  */
 397               t->next = incl_entry->totals;
 398               incl_entry->totals = t;
 399             }
 400           else
 401             {
 402               bfd_size_type *incl_pstridx;
 403
 404               /* We have seen this header file before.  Tell the final
 405                  pass to change the type to N_EXCL.  */
 406               ne->type = (int) N_EXCL;
 407
 408               /* Free off superfluous symbols.  */
 409               free (symb);
 410
 411               /* Mark the skipped symbols.  */
 412
 413               nest = 0;
 414               for (incl_sym = sym + STABSIZE, incl_pstridx = pstridx + 1;
 415                    incl_sym < symend;
 416                    incl_sym += STABSIZE, ++incl_pstridx)
 417                 {
 418                   int incl_type;
 419
 420                   incl_type = incl_sym[TYPEOFF];
 421
 422                   if (incl_type == (int) N_EINCL)
 423                     {
 424                       if (nest == 0)
 425                         {
 426                           *incl_pstridx = (bfd_size_type) -1;
 427                           ++skip;
 428                           break;
 429                         }
 430                       --nest;
 431                     }
 432                   else if (incl_type == (int) N_BINCL)
 433                     ++nest;
 434                   else if (incl_type == (int) N_EXCL)
 435                     /* Keep existing exclusion marks.  */
 436                     continue;
 437                   else if (nest == 0)
 438                     {
 439                       *incl_pstridx = (bfd_size_type) -1;
 440                       ++skip;
 441                     }
 442                 }
 443             }
 444         }
 445     }
 446
 447   free (stabbuf);
 448   stabbuf = NULL;
 449   free (stabstrbuf);
 450   stabstrbuf = NULL;
 451
 452   /* We need to set the section sizes such that the linker will
 453      compute the output section sizes correctly.  We set the .stab
 454      size to not include the entries we don't want.  We set
 455      SEC_EXCLUDE for the .stabstr section, so that it will be dropped
 456      from the link.  We record the size of the strtab in the first
 457      .stabstr section we saw, and make sure we don't set SEC_EXCLUDE
 458      for that section.  */
 459   stabsec->size = (count - skip) * STABSIZE;
 460   if (stabsec->size == 0)
 461     stabsec->flags |= SEC_EXCLUDE | SEC_KEEP;
 462   stabstrsec->flags |= SEC_EXCLUDE | SEC_KEEP;
 463   sinfo->stabstr->size = _bfd_stringtab_size (sinfo->strings);
 464
 465   /* Calculate the `cumulative_skips' array now that stabs have been
 466      deleted for this section.  */
 467
 468   if (skip != 0)
 469     {
 470       bfd_size_type i, offset;
 471       bfd_size_type *pskips;
 472
 473       amt = count * sizeof (bfd_size_type);
 474       secinfo->cumulative_skips = bfd_alloc (abfd, amt);
 475       if (secinfo->cumulative_skips == NULL)
 476         goto error_return;
 477
 478       pskips = secinfo->cumulative_skips;
 479       pstridx = secinfo->stridxs;
 480       offset = 0;
 481
 482       for (i = 0; i < count; i++, pskips++, pstridx++)
 483         {
 484           *pskips = offset;
 485           if (*pstridx == (bfd_size_type) -1)
 486             offset += STABSIZE;
 487         }
 488
 489       BFD_ASSERT (offset != 0);
 490     }
 491
 492   return TRUE;
 493
 494  error_return:
 495   if (stabbuf != NULL)
 496     free (stabbuf);
 497   if (stabstrbuf != NULL)
 498     free (stabstrbuf);
 499   return FALSE;
 500 }
 501 \f
 502 /* This function is called for each input file before the stab
 503    section is relocated.  It discards stab entries for discarded
 504    functions and variables.  The function returns TRUE iff
 505    any entries have been deleted.
 506 */
 507
 508 bfd_boolean
 509 _bfd_discard_section_stabs (bfd *abfd,
 510                             asection *stabsec,
 511                             void * psecinfo,
 512                             bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
 513                             void * cookie)
 514 {
 515   bfd_size_type count, amt;
 516   struct stab_section_info *secinfo;
 517   bfd_byte *stabbuf = NULL;
 518   bfd_byte *sym, *symend;
 519   bfd_size_type skip;
 520   bfd_size_type *pstridx;
 521   int deleting;
 522
 523   if (stabsec->size == 0)
 524     /* This file does not contain stabs debugging information.  */
 525     return FALSE;
 526
 527   if (stabsec->size % STABSIZE != 0)
 528     /* Something is wrong with the format of these stab symbols.
 529        Don't try to optimize them.  */
 530     return FALSE;
 531
 532   if ((stabsec->output_section != NULL
 533        && bfd_is_abs_section (stabsec->output_section)))
 534     /* At least one of the sections is being discarded from the
 535        link, so we should just ignore them.  */
 536     return FALSE;
 537
 538   /* We should have initialized our data in _bfd_link_stab_sections.
 539      If there was some bizarre error reading the string sections, though,
 540      we might not have.  Bail rather than asserting.  */
 541   if (psecinfo == NULL)
 542     return FALSE;
 543
 544   count = stabsec->rawsize / STABSIZE;
 545   secinfo = (struct stab_section_info *) psecinfo;
 546
 547   /* Read the stabs information from abfd.  */
 548   if (!bfd_malloc_and_get_section (abfd, stabsec, &stabbuf))
 549     goto error_return;
 550
 551   /* Look through the stabs symbols and discard any information for
 552      discarded functions.  */
 553   skip = 0;
 554   deleting = -1;
 555
 556   symend = stabbuf + stabsec->rawsize;
 557   for (sym = stabbuf, pstridx = secinfo->stridxs;
 558        sym < symend;
 559        sym += STABSIZE, ++pstridx)
 560     {
 561       int type;
 562
 563       if (*pstridx == (bfd_size_type) -1)
 564         /* This stab was deleted in a previous pass.  */
 565         continue;
 566
 567       type = sym[TYPEOFF];
 568
 569       if (type == (int) N_FUN)
 570         {
 571           int strx = bfd_get_32 (abfd, sym + STRDXOFF);
 572
 573           if (strx == 0)
 574             {
 575               if (deleting)
 576                 {
 577                   skip++;
 578                   *pstridx = -1;
 579                 }
 580               deleting = -1;
 581               continue;
 582             }
 583           deleting = 0;
 584           if ((*reloc_symbol_deleted_p) (sym + VALOFF - stabbuf, cookie))
 585             deleting = 1;
 586         }
 587
 588       if (deleting == 1)
 589         {
 590           *pstridx = -1;
 591           skip++;
 592         }
 593       else if (deleting == -1)
 594         {
 595           /* Outside of a function.  Check for deleted variables.  */
 596           if (type == (int) N_STSYM || type == (int) N_LCSYM)
 597             if ((*reloc_symbol_deleted_p) (sym + VALOFF - stabbuf, cookie))
 598               {
 599                 *pstridx = -1;
 600                 skip ++;
 601               }
 602           /* We should also check for N_GSYM entries which reference a
 603              deleted global, but those are less harmful to debuggers
 604              and would require parsing the stab strings.  */
 605         }
 606     }
 607
 608   free (stabbuf);
 609   stabbuf = NULL;
 610
 611   /* Shrink the stabsec as needed.  */
 612   stabsec->size -= skip * STABSIZE;
 613   if (stabsec->size == 0)
 614     stabsec->flags |= SEC_EXCLUDE | SEC_KEEP;
 615
 616   /* Recalculate the `cumulative_skips' array now that stabs have been
 617      deleted for this section.  */
 618
 619   if (skip != 0)
 620     {
 621       bfd_size_type i, offset;
 622       bfd_size_type *pskips;
 623
 624       if (secinfo->cumulative_skips == NULL)
 625         {
 626           amt = count * sizeof (bfd_size_type);
 627           secinfo->cumulative_skips = bfd_alloc (abfd, amt);
 628           if (secinfo->cumulative_skips == NULL)
 629             goto error_return;
 630         }
 631
 632       pskips = secinfo->cumulative_skips;
 633       pstridx = secinfo->stridxs;
 634       offset = 0;
 635
 636       for (i = 0; i < count; i++, pskips++, pstridx++)
 637         {
 638           *pskips = offset;
 639           if (*pstridx == (bfd_size_type) -1)
 640             offset += STABSIZE;
 641         }
 642
 643       BFD_ASSERT (offset != 0);
 644     }
 645
 646   return skip > 0;
 647
 648  error_return:
 649   if (stabbuf != NULL)
 650     free (stabbuf);
 651   return FALSE;
 652 }
 653
 654 /* Write out the stab section.  This is called with the relocated
 655    contents.  */
 656
 657 bfd_boolean
 658 _bfd_write_section_stabs (bfd *output_bfd,
 659                           struct stab_info *sinfo,
 660                           asection *stabsec,
 661                           void * *psecinfo,
 662                           bfd_byte *contents)
 663 {
 664   struct stab_section_info *secinfo;
 665   struct stab_excl_list *e;
 666   bfd_byte *sym, *tosym, *symend;
 667   bfd_size_type *pstridx;
 668
 669   secinfo = (struct stab_section_info *) *psecinfo;
 670
 671   if (secinfo == NULL)
 672     return bfd_set_section_contents (output_bfd, stabsec->output_section,
 673                                      contents, stabsec->output_offset,
 674                                      stabsec->size);
 675
 676   /* Handle each N_BINCL entry.  */
 677   for (e = secinfo->excls; e != NULL; e = e->next)
 678     {
 679       bfd_byte *excl_sym;
 680
 681       BFD_ASSERT (e->offset < stabsec->rawsize);
 682       excl_sym = contents + e->offset;
 683       bfd_put_32 (output_bfd, e->val, excl_sym + VALOFF);
 684       excl_sym[TYPEOFF] = e->type;
 685     }
 686
 687   /* Copy over all the stabs symbols, omitting the ones we don't want,
 688      and correcting the string indices for those we do want.  */
 689   tosym = contents;
 690   symend = contents + stabsec->rawsize;
 691   for (sym = contents, pstridx = secinfo->stridxs;
 692        sym < symend;
 693        sym += STABSIZE, ++pstridx)
 694     {
 695       if (*pstridx != (bfd_size_type) -1)
 696         {
 697           if (tosym != sym)
 698             memcpy (tosym, sym, STABSIZE);
 699           bfd_put_32 (output_bfd, *pstridx, tosym + STRDXOFF);
 700
 701           if (sym[TYPEOFF] == 0)
 702             {
 703               /* This is the header symbol for the stabs section.  We
 704                  don't really need one, since we have merged all the
 705                  input stabs sections into one, but we generate one
 706                  for the benefit of readers which expect to see one.  */
 707               BFD_ASSERT (sym == contents);
 708               bfd_put_32 (output_bfd, _bfd_stringtab_size (sinfo->strings),
 709                           tosym + VALOFF);
 710               bfd_put_16 (output_bfd,
 711                           stabsec->output_section->size / STABSIZE - 1,
 712                           tosym + DESCOFF);
 713             }
 714
 715           tosym += STABSIZE;
 716         }
 717     }
 718
 719   BFD_ASSERT ((bfd_size_type) (tosym - contents) == stabsec->size);
 720
 721   return bfd_set_section_contents (output_bfd, stabsec->output_section,
 722                                    contents, (file_ptr) stabsec->output_offset,
 723                                    stabsec->size);
 724 }
 725
 726 /* Write out the .stabstr section.  */
 727
 728 bfd_boolean
 729 _bfd_write_stab_strings (bfd *output_bfd, struct stab_info *sinfo)
 730 {
 731   if (bfd_is_abs_section (sinfo->stabstr->output_section))
 732     /* The section was discarded from the link.  */
 733     return TRUE;
 734
 735   BFD_ASSERT ((sinfo->stabstr->output_offset
 736                + _bfd_stringtab_size (sinfo->strings))
 737               <= sinfo->stabstr->output_section->size);
 738
 739   if (bfd_seek (output_bfd,
 740                 (file_ptr) (sinfo->stabstr->output_section->filepos
 741                             + sinfo->stabstr->output_offset),
 742                 SEEK_SET) != 0)
 743     return FALSE;
 744
 745   if (! _bfd_stringtab_emit (output_bfd, sinfo->strings))
 746     return FALSE;
 747
 748   /* We no longer need the stabs information.  */
 749   _bfd_stringtab_free (sinfo->strings);
 750   bfd_hash_table_free (&sinfo->includes);
 751
 752   return TRUE;
 753 }
 754
 755 /* Adjust an address in the .stab section.  Given OFFSET within
 756    STABSEC, this returns the new offset in the adjusted stab section,
 757    or -1 if the address refers to a stab which has been removed.  */
 758
 759 bfd_vma
 760 _bfd_stab_section_offset (asection *stabsec,
 761                           void * psecinfo,
 762                           bfd_vma offset)
 763 {
 764   struct stab_section_info *secinfo;
 765
 766   secinfo = (struct stab_section_info *) psecinfo;
 767
 768   if (secinfo == NULL)
 769     return offset;
 770
 771   if (offset >= stabsec->rawsize)
 772     return offset - stabsec->rawsize + stabsec->size;
 773
 774   if (secinfo->cumulative_skips)
 775     {
 776       bfd_vma i;
 777
 778       i = offset / STABSIZE;
 779
 780       if (secinfo->stridxs [i] == (bfd_size_type) -1)
 781         return (bfd_vma) -1;
 782
 783       return offset - secinfo->cumulative_skips [i];
 784     }
 785
 786   return offset;
 787 }