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