1 /* rddbg.c -- Read debugging information into a generic form. 2 Copyright 1995, 1996, 1997, 2000, 2002, 2003, 2005 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., 51 Franklin Street - Fifth Floor, Boston, MA 21 02110-1301, 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 } 104 names[] = 105 { 106 { ".stab", ".stabstr" }, 107 { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" }, 108 { "$GDB_SYMBOLS$", "$GDB_STRINGS$" } 109 }; 110 unsigned int i; 111 void *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 %ld is corrupt, strx = 0x%x, type = %d\n", 192 bfd_get_filename (abfd), names[i].secname, 193 (long) (stab - stabs) / 12, strx, type); 194 continue; 195 } 196 197 s = (char *) strings + stroff + strx; 198 199 while (*s != '\0' && 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 bfd_boolean 259 read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, 260 void *dhandle, bfd_boolean *pfound) 261 { 262 void *shandle; 263 asymbol **ps, **symend; 264 265 shandle = NULL; 266 symend = syms + symcount; 267 for (ps = syms; ps < symend; ps++) 268 { 269 symbol_info i; 270 271 bfd_get_symbol_info (abfd, *ps, &i); 272 273 if (i.type == '-') 274 { 275 const char *s; 276 char *f; 277 278 if (shandle == NULL) 279 { 280 shandle = start_stab (dhandle, abfd, FALSE, syms, symcount); 281 if (shandle == NULL) 282 return FALSE; 283 } 284 285 *pfound = TRUE; 286 287 s = i.name; 288 f = NULL; 289 while (s[strlen (s) - 1] == '\\' 290 && ps + 1 < symend) 291 { 292 char *sc, *n; 293 294 ++ps; 295 sc = xstrdup (s); 296 sc[strlen (sc) - 1] = '\0'; 297 n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL); 298 free (sc); 299 if (f != NULL) 300 free (f); 301 f = n; 302 s = n; 303 } 304 305 save_stab (i.stab_type, i.stab_desc, i.value, s); 306 307 if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc, 308 i.value, s)) 309 { 310 stab_context (); 311 free_saved_stabs (); 312 return FALSE; 313 } 314 315 /* Don't free f, since I think the stabs code expects 316 strings to hang around. This should be straightened out. 317 FIXME. */ 318 } 319 } 320 321 free_saved_stabs (); 322 323 if (shandle != NULL) 324 { 325 if (! finish_stab (dhandle, shandle)) 326 return FALSE; 327 } 328 329 return TRUE; 330 } 331 332 /* Read IEEE debugging information. */ 333 334 static bfd_boolean 335 read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound) 336 { 337 asection *dsec; 338 bfd_size_type size; 339 bfd_byte *contents; 340 341 /* The BFD backend puts the debugging information into a section 342 named .debug. */ 343 344 dsec = bfd_get_section_by_name (abfd, ".debug"); 345 if (dsec == NULL) 346 return TRUE; 347 348 size = bfd_section_size (abfd, dsec); 349 contents = (bfd_byte *) xmalloc (size); 350 if (! bfd_get_section_contents (abfd, dsec, contents, 0, size)) 351 return FALSE; 352 353 if (! parse_ieee (dhandle, abfd, contents, size)) 354 return FALSE; 355 356 free (contents); 357 358 *pfound = TRUE; 359 360 return TRUE; 361 } 362 363 /* Record stabs strings, so that we can give some context for errors. */ 364 365 #define SAVE_STABS_COUNT (16) 366 367 struct saved_stab 368 { 369 int type; 370 int desc; 371 bfd_vma value; 372 char *string; 373 }; 374 375 static struct saved_stab saved_stabs[SAVE_STABS_COUNT]; 376 static int saved_stabs_index; 377 378 /* Save a stabs string. */ 379 380 static void 381 save_stab (int type, int desc, bfd_vma value, const char *string) 382 { 383 if (saved_stabs[saved_stabs_index].string != NULL) 384 free (saved_stabs[saved_stabs_index].string); 385 saved_stabs[saved_stabs_index].type = type; 386 saved_stabs[saved_stabs_index].desc = desc; 387 saved_stabs[saved_stabs_index].value = value; 388 saved_stabs[saved_stabs_index].string = xstrdup (string); 389 saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT; 390 } 391 392 /* Provide context for an error. */ 393 394 static void 395 stab_context (void) 396 { 397 int i; 398 399 fprintf (stderr, _("Last stabs entries before error:\n")); 400 fprintf (stderr, "n_type n_desc n_value string\n"); 401 402 i = saved_stabs_index; 403 do 404 { 405 struct saved_stab *stabp; 406 407 stabp = saved_stabs + i; 408 if (stabp->string != NULL) 409 { 410 const char *s; 411 412 s = bfd_get_stab_name (stabp->type); 413 if (s != NULL) 414 fprintf (stderr, "%-6s", s); 415 else if (stabp->type == 0) 416 fprintf (stderr, "HdrSym"); 417 else 418 fprintf (stderr, "%-6d", stabp->type); 419 fprintf (stderr, " %-6d ", stabp->desc); 420 fprintf_vma (stderr, stabp->value); 421 if (stabp->type != 0) 422 fprintf (stderr, " %s", stabp->string); 423 fprintf (stderr, "\n"); 424 } 425 i = (i + 1) % SAVE_STABS_COUNT; 426 } 427 while (i != saved_stabs_index); 428 } 429 430 /* Free the saved stab strings. */ 431 432 static void 433 free_saved_stabs (void) 434 { 435 int i; 436 437 for (i = 0; i < SAVE_STABS_COUNT; i++) 438 { 439 if (saved_stabs[i].string != NULL) 440 { 441 free (saved_stabs[i].string); 442 saved_stabs[i].string = NULL; 443 } 444 } 445 446 saved_stabs_index = 0; 447 } 448