binutils/rddbg.c

   1 /* rddbg.c -- Read debugging information into a generic form.
   2    Copyright (C) 1995, 96, 97, 98, 2000 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   unsigned int i;
 111   PTR shandle;
 112
 113   *pfound = false;
 114   shandle = NULL;
 115
 116   for (i = 0; i < sizeof names / sizeof names[0]; i++)
 117     {
 118       asection *sec, *strsec;
 119
 120       sec = bfd_get_section_by_name (abfd, names[i].secname);
 121       strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
 122       if (sec != NULL && strsec != NULL)
 123         {
 124           bfd_size_type stabsize, strsize;
 125           bfd_byte *stabs, *strings;
 126           bfd_byte *stab;
 127           bfd_size_type stroff, next_stroff;
 128
 129           stabsize = bfd_section_size (abfd, sec);
 130           stabs = (bfd_byte *) xmalloc (stabsize);
 131           if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
 132             {
 133               fprintf (stderr, "%s: %s: %s\n",
 134                        bfd_get_filename (abfd), names[i].secname,
 135                        bfd_errmsg (bfd_get_error ()));
 136               return false;
 137             }
 138
 139           strsize = bfd_section_size (abfd, strsec);
 140           strings = (bfd_byte *) xmalloc (strsize);
 141           if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
 142             {
 143               fprintf (stderr, "%s: %s: %s\n",
 144                        bfd_get_filename (abfd), names[i].strsecname,
 145                        bfd_errmsg (bfd_get_error ()));
 146               return false;
 147             }
 148
 149           if (shandle == NULL)
 150             {
 151               shandle = start_stab (dhandle, abfd, true, syms, symcount);
 152               if (shandle == NULL)
 153                 return false;
 154             }
 155
 156           *pfound = true;
 157
 158           stroff = 0;
 159           next_stroff = 0;
 160           for (stab = stabs; stab < stabs + stabsize; stab += 12)
 161             {
 162               unsigned int strx;
 163               int type;
 164               int other;
 165               int desc;
 166               bfd_vma value;
 167
 168               /* This code presumes 32 bit values.  */
 169
 170               strx = bfd_get_32 (abfd, stab);
 171               type = bfd_get_8 (abfd, stab + 4);
 172               other = bfd_get_8 (abfd, stab + 5);
 173               desc = bfd_get_16 (abfd, stab + 6);
 174               value = bfd_get_32 (abfd, stab + 8);
 175
 176               if (type == 0)
 177                 {
 178                   /* Special type 0 stabs indicate the offset to the
 179                      next string table.  */
 180                   stroff = next_stroff;
 181                   next_stroff += value;
 182                 }
 183               else
 184                 {
 185                   char *f, *s;
 186
 187                   f = NULL;
 188
 189                   if (stroff + strx > strsize)
 190                     {
 191                       fprintf (stderr, "%s: %s: stab entry %d is corrupt, strx = 0x%x, type = %d\n",
 192                                bfd_get_filename (abfd), names[i].secname,
 193                                (stab - stabs) / 12, strx, type);
 194                       continue;
 195                     }
 196
 197                   s = (char *) strings + stroff + strx;
 198
 199                   while (s[strlen (s) - 1] == '\\'
 200                          && stab + 12 < stabs + stabsize)
 201                     {
 202                       char *p;
 203
 204                       stab += 12;
 205                       p = s + strlen (s) - 1;
 206                       *p = '\0';
 207                       s = concat (s,
 208                                   ((char *) strings
 209                                    + stroff
 210                                    + bfd_get_32 (abfd, stab)),
 211                                   (const char *) NULL);
 212
 213                       /* We have to restore the backslash, because, if
 214                          the linker is hashing stabs strings, we may
 215                          see the same string more than once.  */
 216                       *p = '\\';
 217
 218                       if (f != NULL)
 219                         free (f);
 220                       f = s;
 221                     }
 222
 223                   save_stab (type, desc, value, s);
 224
 225                   if (! parse_stab (dhandle, shandle, type, desc, value, s))
 226                     {
 227                       stab_context ();
 228                       free_saved_stabs ();
 229                       return false;
 230                     }
 231
 232                   /* Don't free f, since I think the stabs code
 233                      expects strings to hang around.  This should be
 234                      straightened out.  FIXME.  */
 235                 }
 236             }
 237
 238           free_saved_stabs ();
 239           free (stabs);
 240
 241           /* Don't free strings, since I think the stabs code expects
 242              the strings to hang around.  This should be straightened
 243              out.  FIXME.  */
 244         }
 245     }
 246
 247   if (shandle != NULL)
 248     {
 249       if (! finish_stab (dhandle, shandle))
 250         return false;
 251     }
 252
 253   return true;
 254 }
 255
 256 /* Read stabs in the symbol table.  */
 257
 258 static boolean
 259 read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
 260      bfd *abfd;
 261      asymbol **syms;
 262      long symcount;
 263      PTR dhandle;
 264      boolean *pfound;
 265 {
 266   PTR shandle;
 267   asymbol **ps, **symend;
 268
 269   shandle = NULL;
 270   symend = syms + symcount;
 271   for (ps = syms; ps < symend; ps++)
 272     {
 273       symbol_info i;
 274
 275       bfd_get_symbol_info (abfd, *ps, &i);
 276
 277       if (i.type == '-')
 278         {
 279           const char *s;
 280           char *f;
 281
 282           if (shandle == NULL)
 283             {
 284               shandle = start_stab (dhandle, abfd, false, syms, symcount);
 285               if (shandle == NULL)
 286                 return false;
 287             }
 288
 289           *pfound = true;
 290
 291           s = i.name;
 292           f = NULL;
 293           while (s[strlen (s) - 1] == '\\'
 294                  && ps + 1 < symend)
 295             {
 296               char *sc, *n;
 297
 298               ++ps;
 299               sc = xstrdup (s);
 300               sc[strlen (sc) - 1] = '\0';
 301               n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
 302               free (sc);
 303               if (f != NULL)
 304                 free (f);
 305               f = n;
 306               s = n;
 307             }
 308
 309           save_stab (i.stab_type, i.stab_desc, i.value, s);
 310
 311           if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
 312                             i.value, s))
 313             {
 314               stab_context ();
 315               free_saved_stabs ();
 316               return false;
 317             }
 318
 319           /* Don't free f, since I think the stabs code expects
 320              strings to hang around.  This should be straightened out.
 321              FIXME.  */
 322         }
 323     }
 324
 325   free_saved_stabs ();
 326
 327   if (shandle != NULL)
 328     {
 329       if (! finish_stab (dhandle, shandle))
 330         return false;
 331     }
 332
 333   return true;
 334 }
 335
 336 /* Read IEEE debugging information.  */
 337
 338 static boolean
 339 read_ieee_debugging_info (abfd, dhandle, pfound)
 340      bfd *abfd;
 341      PTR dhandle;
 342      boolean *pfound;
 343 {
 344   asection *dsec;
 345   bfd_size_type size;
 346   bfd_byte *contents;
 347
 348   /* The BFD backend puts the debugging information into a section
 349      named .debug.  */
 350
 351   dsec = bfd_get_section_by_name (abfd, ".debug");
 352   if (dsec == NULL)
 353     return true;
 354
 355   size = bfd_section_size (abfd, dsec);
 356   contents = (bfd_byte *) xmalloc (size);
 357   if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
 358     return false;
 359
 360   if (! parse_ieee (dhandle, abfd, contents, size))
 361     return false;
 362
 363   free (contents);
 364
 365   *pfound = true;
 366
 367   return true;
 368 }
 369 \f
 370 /* Record stabs strings, so that we can give some context for errors.  */
 371
 372 #define SAVE_STABS_COUNT (16)
 373
 374 struct saved_stab
 375 {
 376   int type;
 377   int desc;
 378   bfd_vma value;
 379   char *string;
 380 };
 381
 382 static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
 383 static int saved_stabs_index;
 384
 385 /* Save a stabs string.  */
 386
 387 static void
 388 save_stab (type, desc, value, string)
 389      int type;
 390      int desc;
 391      bfd_vma value;
 392      const char *string;
 393 {
 394   if (saved_stabs[saved_stabs_index].string != NULL)
 395     free (saved_stabs[saved_stabs_index].string);
 396   saved_stabs[saved_stabs_index].type = type;
 397   saved_stabs[saved_stabs_index].desc = desc;
 398   saved_stabs[saved_stabs_index].value = value;
 399   saved_stabs[saved_stabs_index].string = xstrdup (string);
 400   saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
 401 }
 402
 403 /* Provide context for an error.  */
 404
 405 static void
 406 stab_context ()
 407 {
 408   int i;
 409
 410   fprintf (stderr, _("Last stabs entries before error:\n"));
 411   fprintf (stderr, "n_type n_desc n_value  string\n");
 412
 413   i = saved_stabs_index;
 414   do
 415     {
 416       struct saved_stab *stabp;
 417
 418       stabp = saved_stabs + i;
 419       if (stabp->string != NULL)
 420         {
 421           const char *s;
 422
 423           s = bfd_get_stab_name (stabp->type);
 424           if (s != NULL)
 425             fprintf (stderr, "%-6s", s);
 426           else if (stabp->type == 0)
 427             fprintf (stderr, "HdrSym");
 428           else
 429             fprintf (stderr, "%-6d", stabp->type);
 430           fprintf (stderr, " %-6d ", stabp->desc);
 431           fprintf_vma (stderr, stabp->value);
 432           if (stabp->type != 0)
 433             fprintf (stderr, " %s", stabp->string);
 434           fprintf (stderr, "\n");
 435         }
 436       i = (i + 1) % SAVE_STABS_COUNT;
 437     }
 438   while (i != saved_stabs_index);
 439 }
 440
 441 /* Free the saved stab strings.  */
 442
 443 static void
 444 free_saved_stabs ()
 445 {
 446   int i;
 447
 448   for (i = 0; i < SAVE_STABS_COUNT; i++)
 449     {
 450       if (saved_stabs[i].string != NULL)
 451         {
 452           free (saved_stabs[i].string);
 453           saved_stabs[i].string = NULL;
 454         }
 455     }
 456
 457   saved_stabs_index = 0;
 458 }