binutils/rddbg.c

   1 /* rddbg.c -- Read debugging information into a generic form.
   2    Copyright 1995, 1996, 1997, 2000, 2002, 2003
   3    Free Software Foundation, Inc.
   4    Written by Ian Lance Taylor <ian@cygnus.com>.
   5
   6    This file is part of GNU Binutils.
   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 2 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., 59 Temple Place - Suite 330, Boston, MA
  21    02111-1307, USA.  */
  22
  23 /* This file reads debugging information into a generic form.  This
  24    file knows how to dig the debugging information out of an object
  25    file.  */
  26
  27 #include "bfd.h"
  28 #include "bucomm.h"
  29 #include "libiberty.h"
  30 #include "debug.h"
  31 #include "budbg.h"
  32
  33 static bfd_boolean read_section_stabs_debugging_info
  34   (bfd *, asymbol **, long, void *, bfd_boolean *);
  35 static bfd_boolean read_symbol_stabs_debugging_info
  36   (bfd *, asymbol **, long, void *, bfd_boolean *);
  37 static bfd_boolean read_ieee_debugging_info (bfd *, void *, bfd_boolean *);
  38 static void save_stab (int, int, bfd_vma, const char *);
  39 static void stab_context (void);
  40 static void free_saved_stabs (void);
  41
  42 /* Read debugging information from a BFD.  Returns a generic debugging
  43    pointer.  */
  44
  45 void *
  46 read_debugging_info (bfd *abfd, asymbol **syms, long symcount)
  47 {
  48   void *dhandle;
  49   bfd_boolean found;
  50
  51   dhandle = debug_init ();
  52   if (dhandle == NULL)
  53     return NULL;
  54
  55   if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
  56                                            &found))
  57     return NULL;
  58
  59   if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
  60     {
  61       if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
  62                                               &found))
  63         return NULL;
  64     }
  65
  66   if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour)
  67     {
  68       if (! read_ieee_debugging_info (abfd, dhandle, &found))
  69         return NULL;
  70     }
  71
  72   /* Try reading the COFF symbols if we didn't find any stabs in COFF
  73      sections.  */
  74   if (! found
  75       && bfd_get_flavour (abfd) == bfd_target_coff_flavour
  76       && symcount > 0)
  77     {
  78       if (! parse_coff (abfd, syms, symcount, dhandle))
  79         return NULL;
  80       found = TRUE;
  81     }
  82
  83   if (! found)
  84     {
  85       non_fatal (_("%s: no recognized debugging information"),
  86                  bfd_get_filename (abfd));
  87       return NULL;
  88     }
  89
  90   return dhandle;
  91 }
  92
  93 /* Read stabs in sections debugging information from a BFD.  */
  94
  95 static bfd_boolean
  96 read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
  97                                    void *dhandle, bfd_boolean *pfound)
  98 {
  99   static struct
 100     {
 101       const char *secname;
 102       const char *strsecname;
 103     } names[] = { { ".stab", ".stabstr" },
 104                   { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" } };
 105   unsigned int i;
 106   void *shandle;
 107
 108   *pfound = FALSE;
 109   shandle = NULL;
 110
 111   for (i = 0; i < sizeof names / sizeof names[0]; i++)
 112     {
 113       asection *sec, *strsec;
 114
 115       sec = bfd_get_section_by_name (abfd, names[i].secname);
 116       strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
 117       if (sec != NULL && strsec != NULL)
 118         {
 119           bfd_size_type stabsize, strsize;
 120           bfd_byte *stabs, *strings;
 121           bfd_byte *stab;
 122           bfd_size_type stroff, next_stroff;
 123
 124           stabsize = bfd_section_size (abfd, sec);
 125           stabs = (bfd_byte *) xmalloc (stabsize);
 126           if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
 127             {
 128               fprintf (stderr, "%s: %s: %s\n",
 129                        bfd_get_filename (abfd), names[i].secname,
 130                        bfd_errmsg (bfd_get_error ()));
 131               return FALSE;
 132             }
 133
 134           strsize = bfd_section_size (abfd, strsec);
 135           strings = (bfd_byte *) xmalloc (strsize);
 136           if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
 137             {
 138               fprintf (stderr, "%s: %s: %s\n",
 139                        bfd_get_filename (abfd), names[i].strsecname,
 140                        bfd_errmsg (bfd_get_error ()));
 141               return FALSE;
 142             }
 143
 144           if (shandle == NULL)
 145             {
 146               shandle = start_stab (dhandle, abfd, TRUE, syms, symcount);
 147               if (shandle == NULL)
 148                 return FALSE;
 149             }
 150
 151           *pfound = TRUE;
 152
 153           stroff = 0;
 154           next_stroff = 0;
 155           for (stab = stabs; stab < stabs + stabsize; stab += 12)
 156             {
 157               unsigned int strx;
 158               int type;
 159               int other;
 160               int desc;
 161               bfd_vma value;
 162
 163               /* This code presumes 32 bit values.  */
 164
 165               strx = bfd_get_32 (abfd, stab);
 166               type = bfd_get_8 (abfd, stab + 4);
 167               other = bfd_get_8 (abfd, stab + 5);
 168               desc = bfd_get_16 (abfd, stab + 6);
 169               value = bfd_get_32 (abfd, stab + 8);
 170
 171               if (type == 0)
 172                 {
 173                   /* Special type 0 stabs indicate the offset to the
 174                      next string table.  */
 175                   stroff = next_stroff;
 176                   next_stroff += value;
 177                 }
 178               else
 179                 {
 180                   char *f, *s;
 181
 182                   f = NULL;
 183
 184                   if (stroff + strx > strsize)
 185                     {
 186                       fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n",
 187                                bfd_get_filename (abfd), names[i].secname,
 188                                (long) (stab - stabs) / 12, strx, type);
 189                       continue;
 190                     }
 191
 192                   s = (char *) strings + stroff + strx;
 193
 194                   while (s[strlen (s) - 1] == '\\'
 195                          && stab + 12 < stabs + stabsize)
 196                     {
 197                       char *p;
 198
 199                       stab += 12;
 200                       p = s + strlen (s) - 1;
 201                       *p = '\0';
 202                       s = concat (s,
 203                                   ((char *) strings
 204                                    + stroff
 205                                    + bfd_get_32 (abfd, stab)),
 206                                   (const char *) NULL);
 207
 208                       /* We have to restore the backslash, because, if
 209                          the linker is hashing stabs strings, we may
 210                          see the same string more than once.  */
 211                       *p = '\\';
 212
 213                       if (f != NULL)
 214                         free (f);
 215                       f = s;
 216                     }
 217
 218                   save_stab (type, desc, value, s);
 219
 220                   if (! parse_stab (dhandle, shandle, type, desc, value, s))
 221                     {
 222                       stab_context ();
 223                       free_saved_stabs ();
 224                       return FALSE;
 225                     }
 226
 227                   /* Don't free f, since I think the stabs code
 228                      expects strings to hang around.  This should be
 229                      straightened out.  FIXME.  */
 230                 }
 231             }
 232
 233           free_saved_stabs ();
 234           free (stabs);
 235
 236           /* Don't free strings, since I think the stabs code expects
 237              the strings to hang around.  This should be straightened
 238              out.  FIXME.  */
 239         }
 240     }
 241
 242   if (shandle != NULL)
 243     {
 244       if (! finish_stab (dhandle, shandle))
 245         return FALSE;
 246     }
 247
 248   return TRUE;
 249 }
 250
 251 /* Read stabs in the symbol table.  */
 252
 253 static bfd_boolean
 254 read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
 255                                   void *dhandle, bfd_boolean *pfound)
 256 {
 257   void *shandle;
 258   asymbol **ps, **symend;
 259
 260   shandle = NULL;
 261   symend = syms + symcount;
 262   for (ps = syms; ps < symend; ps++)
 263     {
 264       symbol_info i;
 265
 266       bfd_get_symbol_info (abfd, *ps, &i);
 267
 268       if (i.type == '-')
 269         {
 270           const char *s;
 271           char *f;
 272
 273           if (shandle == NULL)
 274             {
 275               shandle = start_stab (dhandle, abfd, FALSE, syms, symcount);
 276               if (shandle == NULL)
 277                 return FALSE;
 278             }
 279
 280           *pfound = TRUE;
 281
 282           s = i.name;
 283           f = NULL;
 284           while (s[strlen (s) - 1] == '\\'
 285                  && ps + 1 < symend)
 286             {
 287               char *sc, *n;
 288
 289               ++ps;
 290               sc = xstrdup (s);
 291               sc[strlen (sc) - 1] = '\0';
 292               n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
 293               free (sc);
 294               if (f != NULL)
 295                 free (f);
 296               f = n;
 297               s = n;
 298             }
 299
 300           save_stab (i.stab_type, i.stab_desc, i.value, s);
 301
 302           if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
 303                             i.value, s))
 304             {
 305               stab_context ();
 306               free_saved_stabs ();
 307               return FALSE;
 308             }
 309
 310           /* Don't free f, since I think the stabs code expects
 311              strings to hang around.  This should be straightened out.
 312              FIXME.  */
 313         }
 314     }
 315
 316   free_saved_stabs ();
 317
 318   if (shandle != NULL)
 319     {
 320       if (! finish_stab (dhandle, shandle))
 321         return FALSE;
 322     }
 323
 324   return TRUE;
 325 }
 326
 327 /* Read IEEE debugging information.  */
 328
 329 static bfd_boolean
 330 read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound)
 331 {
 332   asection *dsec;
 333   bfd_size_type size;
 334   bfd_byte *contents;
 335
 336   /* The BFD backend puts the debugging information into a section
 337      named .debug.  */
 338
 339   dsec = bfd_get_section_by_name (abfd, ".debug");
 340   if (dsec == NULL)
 341     return TRUE;
 342
 343   size = bfd_section_size (abfd, dsec);
 344   contents = (bfd_byte *) xmalloc (size);
 345   if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
 346     return FALSE;
 347
 348   if (! parse_ieee (dhandle, abfd, contents, size))
 349     return FALSE;
 350
 351   free (contents);
 352
 353   *pfound = TRUE;
 354
 355   return TRUE;
 356 }
 357 \f
 358 /* Record stabs strings, so that we can give some context for errors.  */
 359
 360 #define SAVE_STABS_COUNT (16)
 361
 362 struct saved_stab
 363 {
 364   int type;
 365   int desc;
 366   bfd_vma value;
 367   char *string;
 368 };
 369
 370 static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
 371 static int saved_stabs_index;
 372
 373 /* Save a stabs string.  */
 374
 375 static void
 376 save_stab (int type, int desc, bfd_vma value, const char *string)
 377 {
 378   if (saved_stabs[saved_stabs_index].string != NULL)
 379     free (saved_stabs[saved_stabs_index].string);
 380   saved_stabs[saved_stabs_index].type = type;
 381   saved_stabs[saved_stabs_index].desc = desc;
 382   saved_stabs[saved_stabs_index].value = value;
 383   saved_stabs[saved_stabs_index].string = xstrdup (string);
 384   saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
 385 }
 386
 387 /* Provide context for an error.  */
 388
 389 static void
 390 stab_context (void)
 391 {
 392   int i;
 393
 394   fprintf (stderr, _("Last stabs entries before error:\n"));
 395   fprintf (stderr, "n_type n_desc n_value  string\n");
 396
 397   i = saved_stabs_index;
 398   do
 399     {
 400       struct saved_stab *stabp;
 401
 402       stabp = saved_stabs + i;
 403       if (stabp->string != NULL)
 404         {
 405           const char *s;
 406
 407           s = bfd_get_stab_name (stabp->type);
 408           if (s != NULL)
 409             fprintf (stderr, "%-6s", s);
 410           else if (stabp->type == 0)
 411             fprintf (stderr, "HdrSym");
 412           else
 413             fprintf (stderr, "%-6d", stabp->type);
 414           fprintf (stderr, " %-6d ", stabp->desc);
 415           fprintf_vma (stderr, stabp->value);
 416           if (stabp->type != 0)
 417             fprintf (stderr, " %s", stabp->string);
 418           fprintf (stderr, "\n");
 419         }
 420       i = (i + 1) % SAVE_STABS_COUNT;
 421     }
 422   while (i != saved_stabs_index);
 423 }
 424
 425 /* Free the saved stab strings.  */
 426
 427 static void
 428 free_saved_stabs (void)
 429 {
 430   int i;
 431
 432   for (i = 0; i < SAVE_STABS_COUNT; i++)
 433     {
 434       if (saved_stabs[i].string != NULL)
 435         {
 436           free (saved_stabs[i].string);
 437           saved_stabs[i].string = NULL;
 438         }
 439     }
 440
 441   saved_stabs_index = 0;
 442 }