binutils/rddbg.c

   1 /* rddbg.c -- Read debugging information into a generic form.
   2    Copyright (C) 1995, 1996 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       fprintf (stderr, "%s: no recognized debugging information\n",
  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               bfd_size_type 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                   s = (char *) strings + stroff + strx;
 189                   while (s[strlen (s) - 1] == '\\'
 190                          && stab + 12 < stabs + stabsize)
 191                     {
 192                       stab += 12;
 193                       s[strlen (s) - 1] = '\0';
 194                       s = concat (s,
 195                                   ((char *) strings
 196                                    + stroff
 197                                    + bfd_get_32 (abfd, stab)),
 198                                   (const char *) NULL);
 199                       if (f != NULL)
 200                         free (f);
 201                       f = s;
 202                     }
 203
 204                   save_stab (type, desc, value, s);
 205
 206                   if (! parse_stab (dhandle, shandle, type, desc, value, s))
 207                     {
 208                       stab_context ();
 209                       free_saved_stabs ();
 210                       return false;
 211                     }
 212
 213                   /* Don't free f, since I think the stabs code
 214                      expects strings to hang around.  This should be
 215                      straightened out.  FIXME.  */
 216                 }
 217             }
 218
 219           free_saved_stabs ();
 220           free (stabs);
 221
 222           /* Don't free strings, since I think the stabs code expects
 223              the strings to hang around.  This should be straightened
 224              out.  FIXME.  */
 225         }
 226     }
 227
 228   if (shandle != NULL)
 229     {
 230       if (! finish_stab (dhandle, shandle))
 231         return false;
 232     }
 233
 234   return true;
 235 }
 236
 237 /* Read stabs in the symbol table.  */
 238
 239 static boolean
 240 read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
 241      bfd *abfd;
 242      asymbol **syms;
 243      long symcount;
 244      PTR dhandle;
 245      boolean *pfound;
 246 {
 247   PTR shandle;
 248   asymbol **ps, **symend;
 249
 250   shandle = NULL;
 251   symend = syms + symcount;
 252   for (ps = syms; ps < symend; ps++)
 253     {
 254       symbol_info i;
 255
 256       bfd_get_symbol_info (abfd, *ps, &i);
 257
 258       if (i.type == '-')
 259         {
 260           const char *s;
 261           char *f;
 262
 263           if (shandle == NULL)
 264             {
 265               shandle = start_stab (dhandle, abfd, false, syms, symcount);
 266               if (shandle == NULL)
 267                 return false;
 268             }
 269
 270           *pfound = true;
 271
 272           s = i.name;
 273           while (s[strlen (s) - 1] == '\\'
 274                  && ps + 1 < symend)
 275             {
 276               char *sc, *n;
 277
 278               ++ps;
 279               sc = xstrdup (s);
 280               sc[strlen (sc) - 1] = '\0';
 281               n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
 282               free (sc);
 283               if (f != NULL)
 284                 free (f);
 285               f = n;
 286               s = n;
 287             }
 288
 289           save_stab (i.stab_type, i.stab_desc, i.value, s);
 290
 291           if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
 292                             i.value, s))
 293             {
 294               stab_context ();
 295               free_saved_stabs ();
 296               return false;
 297             }
 298
 299           free_saved_stabs ();
 300
 301           /* Don't free f, since I think the stabs code expects
 302              strings to hang around.  This should be straightened out.
 303              FIXME.  */
 304         }
 305     }
 306
 307   if (shandle != NULL)
 308     {
 309       if (! finish_stab (dhandle, shandle))
 310         return false;
 311     }
 312
 313   return true;
 314 }
 315
 316 /* Read IEEE debugging information.  */
 317
 318 static boolean
 319 read_ieee_debugging_info (abfd, dhandle, pfound)
 320      bfd *abfd;
 321      PTR dhandle;
 322      boolean *pfound;
 323 {
 324   asection *dsec;
 325   bfd_size_type size;
 326   bfd_byte *contents;
 327
 328   /* The BFD backend puts the debugging information into a section
 329      named .debug.  */
 330
 331   dsec = bfd_get_section_by_name (abfd, ".debug");
 332   if (dsec == NULL)
 333     return true;
 334
 335   size = bfd_section_size (abfd, dsec);
 336   contents = (bfd_byte *) xmalloc (size);
 337   if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
 338     return false;
 339
 340   if (! parse_ieee (dhandle, abfd, contents, size))
 341     return false;
 342
 343   free (contents);
 344
 345   *pfound = true;
 346
 347   return true;
 348 }
 349 \f
 350 /* Record stabs strings, so that we can give some context for errors.  */
 351
 352 #define SAVE_STABS_COUNT (16)
 353
 354 struct saved_stab
 355 {
 356   int type;
 357   int desc;
 358   bfd_vma value;
 359   char *string;
 360 };
 361
 362 static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
 363 static int saved_stabs_index;
 364
 365 /* Save a stabs string.  */
 366
 367 static void
 368 save_stab (type, desc, value, string)
 369      int type;
 370      int desc;
 371      bfd_vma value;
 372      const char *string;
 373 {
 374   if (saved_stabs[saved_stabs_index].string != NULL)
 375     free (saved_stabs[saved_stabs_index].string);
 376   saved_stabs[saved_stabs_index].type = type;
 377   saved_stabs[saved_stabs_index].desc = desc;
 378   saved_stabs[saved_stabs_index].value = value;
 379   saved_stabs[saved_stabs_index].string = xstrdup (string);
 380   saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
 381 }
 382
 383 /* Provide context for an error.  */
 384
 385 static void
 386 stab_context ()
 387 {
 388   int i;
 389
 390   fprintf (stderr, "Last stabs entries before error:\n");
 391   fprintf (stderr, "n_type n_desc n_value  string\n");
 392
 393   i = saved_stabs_index;
 394   do
 395     {
 396       struct saved_stab *stabp;
 397
 398       stabp = saved_stabs + i;
 399       if (stabp->string != NULL)
 400         {
 401           const char *s;
 402
 403           s = bfd_get_stab_name (stabp->type);
 404           if (s != NULL)
 405             fprintf (stderr, "%-6s", s);
 406           else if (stabp->type == 0)
 407             fprintf (stderr, "HdrSym");
 408           else
 409             fprintf (stderr, "%-6d", stabp->type);
 410           fprintf (stderr, " %-6d ", stabp->desc);
 411           fprintf_vma (stderr, stabp->value);
 412           if (stabp->type != 0)
 413             fprintf (stderr, " %s", stabp->string);
 414           fprintf (stderr, "\n");
 415         }
 416       i = (i + 1) % SAVE_STABS_COUNT;
 417     }
 418   while (i != saved_stabs_index);
 419 }
 420
 421 /* Free the saved stab strings.  */
 422
 423 static void
 424 free_saved_stabs ()
 425 {
 426   int i;
 427
 428   for (i = 0; i < SAVE_STABS_COUNT; i++)
 429     if (saved_stabs[i].string != NULL)
 430       free (saved_stabs[i].string);
 431   saved_stabs_index = 0;
 432 }