binutils/rddbg.c

   1 /* rddbg.c -- Read debugging information into a generic form.
   2    Copyright 1995, 1996, 1997, 2000, 2002 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor <ian@cygnus.com>.
   4
   5    This file is part of GNU Binutils.
   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 2 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., 59 Temple Place - Suite 330, Boston, MA
  20    02111-1307, USA.  */
  21
  22 /* This file reads debugging information into a generic form.  This
  23    file knows how to dig the debugging information out of an object
  24    file.  */
  25
  26 #include "bfd.h"
  27 #include "bucomm.h"
  28 #include "libiberty.h"
  29 #include "debug.h"
  30 #include "budbg.h"
  31
  32 static bfd_boolean read_section_stabs_debugging_info
  33   PARAMS ((bfd *, asymbol **, long, PTR, bfd_boolean *));
  34 static bfd_boolean read_symbol_stabs_debugging_info
  35   PARAMS ((bfd *, asymbol **, long, PTR, bfd_boolean *));
  36 static bfd_boolean read_ieee_debugging_info
  37   PARAMS ((bfd *, PTR, bfd_boolean *));
  38 static void save_stab
  39   PARAMS ((int, int, bfd_vma, const char *));
  40 static void stab_context
  41   PARAMS ((void));
  42 static void free_saved_stabs
  43   PARAMS ((void));
  44
  45 /* Read debugging information from a BFD.  Returns a generic debugging
  46    pointer.  */
  47
  48 PTR
  49 read_debugging_info (abfd, syms, symcount)
  50      bfd *abfd;
  51      asymbol **syms;
  52      long symcount;
  53 {
  54   PTR dhandle;
  55   bfd_boolean found;
  56
  57   dhandle = debug_init ();
  58   if (dhandle == NULL)
  59     return NULL;
  60
  61   if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
  62                                            &found))
  63     return NULL;
  64
  65   if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
  66     {
  67       if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
  68                                               &found))
  69         return NULL;
  70     }
  71
  72   if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour)
  73     {
  74       if (! read_ieee_debugging_info (abfd, dhandle, &found))
  75         return NULL;
  76     }
  77
  78   /* Try reading the COFF symbols if we didn't find any stabs in COFF
  79      sections.  */
  80   if (! found
  81       && bfd_get_flavour (abfd) == bfd_target_coff_flavour
  82       && symcount > 0)
  83     {
  84       if (! parse_coff (abfd, syms, symcount, dhandle))
  85         return NULL;
  86       found = TRUE;
  87     }
  88
  89   if (! found)
  90     {
  91       non_fatal (_("%s: no recognized debugging information"),
  92                  bfd_get_filename (abfd));
  93       return NULL;
  94     }
  95
  96   return dhandle;
  97 }
  98
  99 /* Read stabs in sections debugging information from a BFD.  */
 100
 101 static bfd_boolean
 102 read_section_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
 103      bfd *abfd;
 104      asymbol **syms;
 105      long symcount;
 106      PTR dhandle;
 107      bfd_boolean *pfound;
 108 {
 109   static struct
 110     {
 111       const char *secname;
 112       const char *strsecname;
 113     } names[] = { { ".stab", ".stabstr" },
 114                   { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" } };
 115   unsigned int i;
 116   PTR shandle;
 117
 118   *pfound = FALSE;
 119   shandle = NULL;
 120
 121   for (i = 0; i < sizeof names / sizeof names[0]; i++)
 122     {
 123       asection *sec, *strsec;
 124
 125       sec = bfd_get_section_by_name (abfd, names[i].secname);
 126       strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
 127       if (sec != NULL && strsec != NULL)
 128         {
 129           bfd_size_type stabsize, strsize;
 130           bfd_byte *stabs, *strings;
 131           bfd_byte *stab;
 132           bfd_size_type stroff, next_stroff;
 133
 134           stabsize = bfd_section_size (abfd, sec);
 135           stabs = (bfd_byte *) xmalloc (stabsize);
 136           if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
 137             {
 138               fprintf (stderr, "%s: %s: %s\n",
 139                        bfd_get_filename (abfd), names[i].secname,
 140                        bfd_errmsg (bfd_get_error ()));
 141               return FALSE;
 142             }
 143
 144           strsize = bfd_section_size (abfd, strsec);
 145           strings = (bfd_byte *) xmalloc (strsize);
 146           if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
 147             {
 148               fprintf (stderr, "%s: %s: %s\n",
 149                        bfd_get_filename (abfd), names[i].strsecname,
 150                        bfd_errmsg (bfd_get_error ()));
 151               return FALSE;
 152             }
 153
 154           if (shandle == NULL)
 155             {
 156               shandle = start_stab (dhandle, abfd, TRUE, syms, symcount);
 157               if (shandle == NULL)
 158                 return FALSE;
 159             }
 160
 161           *pfound = TRUE;
 162
 163           stroff = 0;
 164           next_stroff = 0;
 165           for (stab = stabs; stab < stabs + stabsize; stab += 12)
 166             {
 167               unsigned int strx;
 168               int type;
 169               int other;
 170               int desc;
 171               bfd_vma value;
 172
 173               /* This code presumes 32 bit values.  */
 174
 175               strx = bfd_get_32 (abfd, stab);
 176               type = bfd_get_8 (abfd, stab + 4);
 177               other = bfd_get_8 (abfd, stab + 5);
 178               desc = bfd_get_16 (abfd, stab + 6);
 179               value = bfd_get_32 (abfd, stab + 8);
 180
 181               if (type == 0)
 182                 {
 183                   /* Special type 0 stabs indicate the offset to the
 184                      next string table.  */
 185                   stroff = next_stroff;
 186                   next_stroff += value;
 187                 }
 188               else
 189                 {
 190                   char *f, *s;
 191
 192                   f = NULL;
 193
 194                   if (stroff + strx > strsize)
 195                     {
 196                       fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n",
 197                                bfd_get_filename (abfd), names[i].secname,
 198                                (long) (stab - stabs) / 12, strx, type);
 199                       continue;
 200                     }
 201
 202                   s = (char *) strings + stroff + strx;
 203
 204                   while (s[strlen (s) - 1] == '\\'
 205                          && stab + 12 < stabs + stabsize)
 206                     {
 207                       char *p;
 208
 209                       stab += 12;
 210                       p = s + strlen (s) - 1;
 211                       *p = '\0';
 212                       s = concat (s,
 213                                   ((char *) strings
 214                                    + stroff
 215                                    + bfd_get_32 (abfd, stab)),
 216                                   (const char *) NULL);
 217
 218                       /* We have to restore the backslash, because, if
 219                          the linker is hashing stabs strings, we may
 220                          see the same string more than once.  */
 221                       *p = '\\';
 222
 223                       if (f != NULL)
 224                         free (f);
 225                       f = s;
 226                     }
 227
 228                   save_stab (type, desc, value, s);
 229
 230                   if (! parse_stab (dhandle, shandle, type, desc, value, s))
 231                     {
 232                       stab_context ();
 233                       free_saved_stabs ();
 234                       return FALSE;
 235                     }
 236
 237                   /* Don't free f, since I think the stabs code
 238                      expects strings to hang around.  This should be
 239                      straightened out.  FIXME.  */
 240                 }
 241             }
 242
 243           free_saved_stabs ();
 244           free (stabs);
 245
 246           /* Don't free strings, since I think the stabs code expects
 247              the strings to hang around.  This should be straightened
 248              out.  FIXME.  */
 249         }
 250     }
 251
 252   if (shandle != NULL)
 253     {
 254       if (! finish_stab (dhandle, shandle))
 255         return FALSE;
 256     }
 257
 258   return TRUE;
 259 }
 260
 261 /* Read stabs in the symbol table.  */
 262
 263 static bfd_boolean
 264 read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
 265      bfd *abfd;
 266      asymbol **syms;
 267      long symcount;
 268      PTR dhandle;
 269      bfd_boolean *pfound;
 270 {
 271   PTR shandle;
 272   asymbol **ps, **symend;
 273
 274   shandle = NULL;
 275   symend = syms + symcount;
 276   for (ps = syms; ps < symend; ps++)
 277     {
 278       symbol_info i;
 279
 280       bfd_get_symbol_info (abfd, *ps, &i);
 281
 282       if (i.type == '-')
 283         {
 284           const char *s;
 285           char *f;
 286
 287           if (shandle == NULL)
 288             {
 289               shandle = start_stab (dhandle, abfd, FALSE, syms, symcount);
 290               if (shandle == NULL)
 291                 return FALSE;
 292             }
 293
 294           *pfound = TRUE;
 295
 296           s = i.name;
 297           f = NULL;
 298           while (s[strlen (s) - 1] == '\\'
 299                  && ps + 1 < symend)
 300             {
 301               char *sc, *n;
 302
 303               ++ps;
 304               sc = xstrdup (s);
 305               sc[strlen (sc) - 1] = '\0';
 306               n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
 307               free (sc);
 308               if (f != NULL)
 309                 free (f);
 310               f = n;
 311               s = n;
 312             }
 313
 314           save_stab (i.stab_type, i.stab_desc, i.value, s);
 315
 316           if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
 317                             i.value, s))
 318             {
 319               stab_context ();
 320               free_saved_stabs ();
 321               return FALSE;
 322             }
 323
 324           /* Don't free f, since I think the stabs code expects
 325              strings to hang around.  This should be straightened out.
 326              FIXME.  */
 327         }
 328     }
 329
 330   free_saved_stabs ();
 331
 332   if (shandle != NULL)
 333     {
 334       if (! finish_stab (dhandle, shandle))
 335         return FALSE;
 336     }
 337
 338   return TRUE;
 339 }
 340
 341 /* Read IEEE debugging information.  */
 342
 343 static bfd_boolean
 344 read_ieee_debugging_info (abfd, dhandle, pfound)
 345      bfd *abfd;
 346      PTR dhandle;
 347      bfd_boolean *pfound;
 348 {
 349   asection *dsec;
 350   bfd_size_type size;
 351   bfd_byte *contents;
 352
 353   /* The BFD backend puts the debugging information into a section
 354      named .debug.  */
 355
 356   dsec = bfd_get_section_by_name (abfd, ".debug");
 357   if (dsec == NULL)
 358     return TRUE;
 359
 360   size = bfd_section_size (abfd, dsec);
 361   contents = (bfd_byte *) xmalloc (size);
 362   if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
 363     return FALSE;
 364
 365   if (! parse_ieee (dhandle, abfd, contents, size))
 366     return FALSE;
 367
 368   free (contents);
 369
 370   *pfound = TRUE;
 371
 372   return TRUE;
 373 }
 374 \f
 375 /* Record stabs strings, so that we can give some context for errors.  */
 376
 377 #define SAVE_STABS_COUNT (16)
 378
 379 struct saved_stab
 380 {
 381   int type;
 382   int desc;
 383   bfd_vma value;
 384   char *string;
 385 };
 386
 387 static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
 388 static int saved_stabs_index;
 389
 390 /* Save a stabs string.  */
 391
 392 static void
 393 save_stab (type, desc, value, string)
 394      int type;
 395      int desc;
 396      bfd_vma value;
 397      const char *string;
 398 {
 399   if (saved_stabs[saved_stabs_index].string != NULL)
 400     free (saved_stabs[saved_stabs_index].string);
 401   saved_stabs[saved_stabs_index].type = type;
 402   saved_stabs[saved_stabs_index].desc = desc;
 403   saved_stabs[saved_stabs_index].value = value;
 404   saved_stabs[saved_stabs_index].string = xstrdup (string);
 405   saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
 406 }
 407
 408 /* Provide context for an error.  */
 409
 410 static void
 411 stab_context ()
 412 {
 413   int i;
 414
 415   fprintf (stderr, _("Last stabs entries before error:\n"));
 416   fprintf (stderr, "n_type n_desc n_value  string\n");
 417
 418   i = saved_stabs_index;
 419   do
 420     {
 421       struct saved_stab *stabp;
 422
 423       stabp = saved_stabs + i;
 424       if (stabp->string != NULL)
 425         {
 426           const char *s;
 427
 428           s = bfd_get_stab_name (stabp->type);
 429           if (s != NULL)
 430             fprintf (stderr, "%-6s", s);
 431           else if (stabp->type == 0)
 432             fprintf (stderr, "HdrSym");
 433           else
 434             fprintf (stderr, "%-6d", stabp->type);
 435           fprintf (stderr, " %-6d ", stabp->desc);
 436           fprintf_vma (stderr, stabp->value);
 437           if (stabp->type != 0)
 438             fprintf (stderr, " %s", stabp->string);
 439           fprintf (stderr, "\n");
 440         }
 441       i = (i + 1) % SAVE_STABS_COUNT;
 442     }
 443   while (i != saved_stabs_index);
 444 }
 445
 446 /* Free the saved stab strings.  */
 447
 448 static void
 449 free_saved_stabs ()
 450 {
 451   int i;
 452
 453   for (i = 0; i < SAVE_STABS_COUNT; i++)
 454     {
 455       if (saved_stabs[i].string != NULL)
 456         {
 457           free (saved_stabs[i].string);
 458           saved_stabs[i].string = NULL;
 459         }
 460     }
 461
 462   saved_stabs_index = 0;
 463 }