1 /* rddbg.c -- Read debugging information into a generic form. 2 Copyright 1995, 1996, 1997, 2000, 2002, 2003, 2005, 2007, 2008 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 3 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 24 /* This file reads debugging information into a generic form. This 25 file knows how to dig the debugging information out of an object 26 file. */ 27 28 #include "sysdep.h" 29 #include "bfd.h" 30 #include "libiberty.h" 31 #include "bucomm.h" 32 #include "debug.h" 33 #include "budbg.h" 34 35 static bfd_boolean read_section_stabs_debugging_info 36 (bfd *, asymbol **, long, void *, bfd_boolean *); 37 static bfd_boolean read_symbol_stabs_debugging_info 38 (bfd *, asymbol **, long, void *, bfd_boolean *); 39 static bfd_boolean read_ieee_debugging_info (bfd *, void *, bfd_boolean *); 40 static void save_stab (int, int, bfd_vma, const char *); 41 static void stab_context (void); 42 static void free_saved_stabs (void); 43 44 /* Read debugging information from a BFD. Returns a generic debugging 45 pointer. */ 46 47 void * 48 read_debugging_info (bfd *abfd, asymbol **syms, long symcount, bfd_boolean no_messages) 49 { 50 void *dhandle; 51 bfd_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 if (! no_messages) 88 non_fatal (_("%s: no recognized debugging information"), 89 bfd_get_filename (abfd)); 90 return NULL; 91 } 92 93 return dhandle; 94 } 95 96 /* Read stabs in sections debugging information from a BFD. */ 97 98 static bfd_boolean 99 read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, 100 void *dhandle, bfd_boolean *pfound) 101 { 102 static struct 103 { 104 const char *secname; 105 const char *strsecname; 106 } 107 names[] = 108 { 109 { ".stab", ".stabstr" }, 110 { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" }, 111 { "$GDB_SYMBOLS$", "$GDB_STRINGS$" } 112 }; 113 unsigned int i; 114 void *shandle; 115 116 *pfound = FALSE; 117 shandle = NULL; 118 119 for (i = 0; i < sizeof names / sizeof names[0]; i++) 120 { 121 asection *sec, *strsec; 122 123 sec = bfd_get_section_by_name (abfd, names[i].secname); 124 strsec = bfd_get_section_by_name (abfd, names[i].strsecname); 125 if (sec != NULL && strsec != NULL) 126 { 127 bfd_size_type stabsize, strsize; 128 bfd_byte *stabs, *strings; 129 bfd_byte *stab; 130 bfd_size_type stroff, next_stroff; 131 132 stabsize = bfd_section_size (abfd, sec); 133 stabs = (bfd_byte *) xmalloc (stabsize); 134 if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize)) 135 { 136 fprintf (stderr, "%s: %s: %s\n", 137 bfd_get_filename (abfd), names[i].secname, 138 bfd_errmsg (bfd_get_error ())); 139 return FALSE; 140 } 141 142 strsize = bfd_section_size (abfd, strsec); 143 strings = (bfd_byte *) xmalloc (strsize); 144 if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize)) 145 { 146 fprintf (stderr, "%s: %s: %s\n", 147 bfd_get_filename (abfd), names[i].strsecname, 148 bfd_errmsg (bfd_get_error ())); 149 return FALSE; 150 } 151 152 if (shandle == NULL) 153 { 154 shandle = start_stab (dhandle, abfd, TRUE, syms, symcount); 155 if (shandle == NULL) 156 return FALSE; 157 } 158 159 *pfound = TRUE; 160 161 stroff = 0; 162 next_stroff = 0; 163 for (stab = stabs; stab < stabs + stabsize; stab += 12) 164 { 165 unsigned int strx; 166 int type; 167 int other; 168 int desc; 169 bfd_vma value; 170 171 /* This code presumes 32 bit values. */ 172 173 strx = bfd_get_32 (abfd, stab); 174 type = bfd_get_8 (abfd, stab + 4); 175 other = bfd_get_8 (abfd, stab + 5); 176 desc = bfd_get_16 (abfd, stab + 6); 177 value = bfd_get_32 (abfd, stab + 8); 178 179 if (type == 0) 180 { 181 /* Special type 0 stabs indicate the offset to the 182 next string table. */ 183 stroff = next_stroff; 184 next_stroff += value; 185 } 186 else 187 { 188 char *f, *s; 189 190 f = NULL; 191 192 if (stroff + strx > strsize) 193 { 194 fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n", 195 bfd_get_filename (abfd), names[i].secname, 196 (long) (stab - stabs) / 12, strx, type); 197 continue; 198 } 199 200 s = (char *) strings + stroff + strx; 201 202 while (s[strlen (s) - 1] == '\\' 203 && stab + 12 < stabs + stabsize) 204 { 205 char *p; 206 207 stab += 12; 208 p = s + strlen (s) - 1; 209 *p = '\0'; 210 s = concat (s, 211 ((char *) strings 212 + stroff 213 + bfd_get_32 (abfd, stab)), 214 (const char *) NULL); 215 216 /* We have to restore the backslash, because, if 217 the linker is hashing stabs strings, we may 218 see the same string more than once. */ 219 *p = '\\'; 220 221 if (f != NULL) 222 free (f); 223 f = s; 224 } 225 226 save_stab (type, desc, value, s); 227 228 if (! parse_stab (dhandle, shandle, type, desc, value, s)) 229 { 230 stab_context (); 231 free_saved_stabs (); 232 return FALSE; 233 } 234 235 /* Don't free f, since I think the stabs code 236 expects strings to hang around. This should be 237 straightened out. FIXME. */ 238 } 239 } 240 241 free_saved_stabs (); 242 free (stabs); 243 244 /* Don't free strings, since I think the stabs code expects 245 the strings to hang around. This should be straightened 246 out. FIXME. */ 247 } 248 } 249 250 if (shandle != NULL) 251 { 252 if (! finish_stab (dhandle, shandle)) 253 return FALSE; 254 } 255 256 return TRUE; 257 } 258 259 /* Read stabs in the symbol table. */ 260 261 static bfd_boolean 262 read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, 263 void *dhandle, bfd_boolean *pfound) 264 { 265 void *shandle; 266 asymbol **ps, **symend; 267 268 shandle = NULL; 269 symend = syms + symcount; 270 for (ps = syms; ps < symend; ps++) 271 { 272 symbol_info i; 273 274 bfd_get_symbol_info (abfd, *ps, &i); 275 276 if (i.type == '-') 277 { 278 const char *s; 279 char *f; 280 281 if (shandle == NULL) 282 { 283 shandle = start_stab (dhandle, abfd, FALSE, syms, symcount); 284 if (shandle == NULL) 285 return FALSE; 286 } 287 288 *pfound = TRUE; 289 290 s = i.name; 291 f = NULL; 292 while (s[strlen (s) - 1] == '\\' 293 && ps + 1 < symend) 294 { 295 char *sc, *n; 296 297 ++ps; 298 sc = xstrdup (s); 299 sc[strlen (sc) - 1] = '\0'; 300 n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL); 301 free (sc); 302 if (f != NULL) 303 free (f); 304 f = n; 305 s = n; 306 } 307 308 save_stab (i.stab_type, i.stab_desc, i.value, s); 309 310 if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc, 311 i.value, s)) 312 { 313 stab_context (); 314 free_saved_stabs (); 315 return FALSE; 316 } 317 318 /* Don't free f, since I think the stabs code expects 319 strings to hang around. This should be straightened out. 320 FIXME. */ 321 } 322 } 323 324 free_saved_stabs (); 325 326 if (shandle != NULL) 327 { 328 if (! finish_stab (dhandle, shandle)) 329 return FALSE; 330 } 331 332 return TRUE; 333 } 334 335 /* Read IEEE debugging information. */ 336 337 static bfd_boolean 338 read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound) 339 { 340 asection *dsec; 341 bfd_size_type size; 342 bfd_byte *contents; 343 344 /* The BFD backend puts the debugging information into a section 345 named .debug. */ 346 347 dsec = bfd_get_section_by_name (abfd, ".debug"); 348 if (dsec == NULL) 349 return TRUE; 350 351 size = bfd_section_size (abfd, dsec); 352 contents = (bfd_byte *) xmalloc (size); 353 if (! bfd_get_section_contents (abfd, dsec, contents, 0, size)) 354 return FALSE; 355 356 if (! parse_ieee (dhandle, abfd, contents, size)) 357 return FALSE; 358 359 free (contents); 360 361 *pfound = TRUE; 362 363 return TRUE; 364 } 365 366 /* Record stabs strings, so that we can give some context for errors. */ 367 368 #define SAVE_STABS_COUNT (16) 369 370 struct saved_stab 371 { 372 int type; 373 int desc; 374 bfd_vma value; 375 char *string; 376 }; 377 378 static struct saved_stab saved_stabs[SAVE_STABS_COUNT]; 379 static int saved_stabs_index; 380 381 /* Save a stabs string. */ 382 383 static void 384 save_stab (int type, int desc, bfd_vma value, const char *string) 385 { 386 if (saved_stabs[saved_stabs_index].string != NULL) 387 free (saved_stabs[saved_stabs_index].string); 388 saved_stabs[saved_stabs_index].type = type; 389 saved_stabs[saved_stabs_index].desc = desc; 390 saved_stabs[saved_stabs_index].value = value; 391 saved_stabs[saved_stabs_index].string = xstrdup (string); 392 saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT; 393 } 394 395 /* Provide context for an error. */ 396 397 static void 398 stab_context (void) 399 { 400 int i; 401 402 fprintf (stderr, _("Last stabs entries before error:\n")); 403 fprintf (stderr, "n_type n_desc n_value string\n"); 404 405 i = saved_stabs_index; 406 do 407 { 408 struct saved_stab *stabp; 409 410 stabp = saved_stabs + i; 411 if (stabp->string != NULL) 412 { 413 const char *s; 414 415 s = bfd_get_stab_name (stabp->type); 416 if (s != NULL) 417 fprintf (stderr, "%-6s", s); 418 else if (stabp->type == 0) 419 fprintf (stderr, "HdrSym"); 420 else 421 fprintf (stderr, "%-6d", stabp->type); 422 fprintf (stderr, " %-6d ", stabp->desc); 423 fprintf_vma (stderr, stabp->value); 424 if (stabp->type != 0) 425 fprintf (stderr, " %s", stabp->string); 426 fprintf (stderr, "\n"); 427 } 428 i = (i + 1) % SAVE_STABS_COUNT; 429 } 430 while (i != saved_stabs_index); 431 } 432 433 /* Free the saved stab strings. */ 434 435 static void 436 free_saved_stabs (void) 437 { 438 int i; 439 440 for (i = 0; i < SAVE_STABS_COUNT; i++) 441 { 442 if (saved_stabs[i].string != NULL) 443 { 444 free (saved_stabs[i].string); 445 saved_stabs[i].string = NULL; 446 } 447 } 448 449 saved_stabs_index = 0; 450 } 451