| 1 | /* rddbg.c -- Read debugging information into a generic form. |
| 2 | Copyright (C) 1995-2018 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 3 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., 51 Franklin Street - Fifth Floor, Boston, MA |
| 20 | 02110-1301, USA. */ |
| 21 | |
| 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 "sysdep.h" |
| 28 | #include "bfd.h" |
| 29 | #include "libiberty.h" |
| 30 | #include "bucomm.h" |
| 31 | #include "debug.h" |
| 32 | #include "budbg.h" |
| 33 | |
| 34 | static bfd_boolean read_section_stabs_debugging_info |
| 35 | (bfd *, asymbol **, long, void *, bfd_boolean *); |
| 36 | static bfd_boolean read_symbol_stabs_debugging_info |
| 37 | (bfd *, asymbol **, long, 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, bfd_boolean no_messages) |
| 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 | /* Try reading the COFF symbols if we didn't find any stabs in COFF |
| 67 | sections. */ |
| 68 | if (! found |
| 69 | && bfd_get_flavour (abfd) == bfd_target_coff_flavour |
| 70 | && symcount > 0) |
| 71 | { |
| 72 | if (! parse_coff (abfd, syms, symcount, dhandle)) |
| 73 | return NULL; |
| 74 | found = TRUE; |
| 75 | } |
| 76 | |
| 77 | if (! found) |
| 78 | { |
| 79 | if (! no_messages) |
| 80 | non_fatal (_("%s: no recognized debugging information"), |
| 81 | bfd_get_filename (abfd)); |
| 82 | return NULL; |
| 83 | } |
| 84 | |
| 85 | return dhandle; |
| 86 | } |
| 87 | |
| 88 | /* Read stabs in sections debugging information from a BFD. */ |
| 89 | |
| 90 | static bfd_boolean |
| 91 | read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, |
| 92 | void *dhandle, bfd_boolean *pfound) |
| 93 | { |
| 94 | static struct |
| 95 | { |
| 96 | const char *secname; |
| 97 | const char *strsecname; |
| 98 | } |
| 99 | names[] = |
| 100 | { |
| 101 | { ".stab", ".stabstr" }, |
| 102 | { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" }, |
| 103 | { "$GDB_SYMBOLS$", "$GDB_STRINGS$" } |
| 104 | }; |
| 105 | unsigned int i; |
| 106 | void *shandle; |
| 107 | |
| 108 | *pfound = FALSE; |
| 109 | shandle = NULL; |
| 110 | |
| 111 | for (i = 0; i < sizeof names / sizeof names[0]; i++) |
| 112 | { |
| 113 | asection *sec, *strsec; |
| 114 | |
| 115 | sec = bfd_get_section_by_name (abfd, names[i].secname); |
| 116 | strsec = bfd_get_section_by_name (abfd, names[i].strsecname); |
| 117 | if (sec != NULL && strsec != NULL) |
| 118 | { |
| 119 | bfd_size_type stabsize, strsize; |
| 120 | bfd_byte *stabs, *strings; |
| 121 | bfd_byte *stab; |
| 122 | bfd_size_type stroff, next_stroff; |
| 123 | |
| 124 | stabsize = bfd_section_size (abfd, sec); |
| 125 | stabs = (bfd_byte *) xmalloc (stabsize); |
| 126 | if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize)) |
| 127 | { |
| 128 | fprintf (stderr, "%s: %s: %s\n", |
| 129 | bfd_get_filename (abfd), names[i].secname, |
| 130 | bfd_errmsg (bfd_get_error ())); |
| 131 | free (shandle); |
| 132 | free (stabs); |
| 133 | return FALSE; |
| 134 | } |
| 135 | |
| 136 | strsize = bfd_section_size (abfd, strsec); |
| 137 | strings = (bfd_byte *) xmalloc (strsize + 1); |
| 138 | if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize)) |
| 139 | { |
| 140 | fprintf (stderr, "%s: %s: %s\n", |
| 141 | bfd_get_filename (abfd), names[i].strsecname, |
| 142 | bfd_errmsg (bfd_get_error ())); |
| 143 | free (shandle); |
| 144 | free (strings); |
| 145 | free (stabs); |
| 146 | return FALSE; |
| 147 | } |
| 148 | /* Zero terminate the strings table, just in case. */ |
| 149 | strings [strsize] = 0; |
| 150 | if (shandle == NULL) |
| 151 | { |
| 152 | shandle = start_stab (dhandle, abfd, TRUE, syms, symcount); |
| 153 | if (shandle == NULL) |
| 154 | { |
| 155 | free (strings); |
| 156 | free (stabs); |
| 157 | return FALSE; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | *pfound = TRUE; |
| 162 | |
| 163 | stroff = 0; |
| 164 | next_stroff = 0; |
| 165 | /* PR 17512: file: 078-60391-0.001:0.1. */ |
| 166 | for (stab = stabs; stab <= (stabs + stabsize) - 12; stab += 12) |
| 167 | { |
| 168 | unsigned int strx; |
| 169 | int type; |
| 170 | int other ATTRIBUTE_UNUSED; |
| 171 | int desc; |
| 172 | bfd_vma value; |
| 173 | |
| 174 | /* This code presumes 32 bit values. */ |
| 175 | |
| 176 | strx = bfd_get_32 (abfd, stab); |
| 177 | type = bfd_get_8 (abfd, stab + 4); |
| 178 | other = bfd_get_8 (abfd, stab + 5); |
| 179 | desc = bfd_get_16 (abfd, stab + 6); |
| 180 | value = bfd_get_32 (abfd, stab + 8); |
| 181 | |
| 182 | if (type == 0) |
| 183 | { |
| 184 | /* Special type 0 stabs indicate the offset to the |
| 185 | next string table. */ |
| 186 | stroff = next_stroff; |
| 187 | next_stroff += value; |
| 188 | } |
| 189 | else |
| 190 | { |
| 191 | size_t len; |
| 192 | char *f, *s; |
| 193 | |
| 194 | if (stroff + strx >= strsize) |
| 195 | { |
| 196 | fprintf (stderr, _("%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n"), |
| 197 | bfd_get_filename (abfd), names[i].secname, |
| 198 | (long) (stab - stabs) / 12, strx, type); |
| 199 | continue; |
| 200 | } |
| 201 | |
| 202 | s = (char *) strings + stroff + strx; |
| 203 | f = NULL; |
| 204 | |
| 205 | /* PR 17512: file: 002-87578-0.001:0.1. |
| 206 | It is possible to craft a file where, without the 'strlen (s) > 0', |
| 207 | an attempt to read the byte before 'strings' would occur. */ |
| 208 | while ((len = strlen (s)) > 0 |
| 209 | && s[len - 1] == '\\' |
| 210 | && stab + 12 < stabs + stabsize) |
| 211 | { |
| 212 | char *p; |
| 213 | |
| 214 | stab += 12; |
| 215 | p = s + len - 1; |
| 216 | *p = '\0'; |
| 217 | strx = stroff + bfd_get_32 (abfd, stab); |
| 218 | if (strx >= strsize) |
| 219 | { |
| 220 | fprintf (stderr, _("%s: %s: stab entry %ld is corrupt\n"), |
| 221 | bfd_get_filename (abfd), names[i].secname, |
| 222 | (long) (stab - stabs) / 12); |
| 223 | break; |
| 224 | } |
| 225 | |
| 226 | s = concat (s, (char *) strings + strx, |
| 227 | (const char *) NULL); |
| 228 | |
| 229 | /* We have to restore the backslash, because, if |
| 230 | the linker is hashing stabs strings, we may |
| 231 | see the same string more than once. */ |
| 232 | *p = '\\'; |
| 233 | |
| 234 | free (f); |
| 235 | f = s; |
| 236 | } |
| 237 | |
| 238 | save_stab (type, desc, value, s); |
| 239 | |
| 240 | if (! parse_stab (dhandle, shandle, type, desc, value, s)) |
| 241 | { |
| 242 | stab_context (); |
| 243 | free_saved_stabs (); |
| 244 | free (f); |
| 245 | free (shandle); |
| 246 | free (stabs); |
| 247 | free (strings); |
| 248 | return FALSE; |
| 249 | } |
| 250 | |
| 251 | /* Don't free f, since I think the stabs code |
| 252 | expects strings to hang around. This should be |
| 253 | straightened out. FIXME. */ |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | free_saved_stabs (); |
| 258 | free (stabs); |
| 259 | |
| 260 | /* Don't free strings, since I think the stabs code expects |
| 261 | the strings to hang around. This should be straightened |
| 262 | out. FIXME. */ |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | if (shandle != NULL) |
| 267 | { |
| 268 | if (! finish_stab (dhandle, shandle)) |
| 269 | return FALSE; |
| 270 | } |
| 271 | |
| 272 | return TRUE; |
| 273 | } |
| 274 | |
| 275 | /* Read stabs in the symbol table. */ |
| 276 | |
| 277 | static bfd_boolean |
| 278 | read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, |
| 279 | void *dhandle, bfd_boolean *pfound) |
| 280 | { |
| 281 | void *shandle; |
| 282 | asymbol **ps, **symend; |
| 283 | |
| 284 | shandle = NULL; |
| 285 | symend = syms + symcount; |
| 286 | for (ps = syms; ps < symend; ps++) |
| 287 | { |
| 288 | symbol_info i; |
| 289 | |
| 290 | bfd_get_symbol_info (abfd, *ps, &i); |
| 291 | |
| 292 | if (i.type == '-') |
| 293 | { |
| 294 | const char *s; |
| 295 | char *f; |
| 296 | |
| 297 | if (shandle == NULL) |
| 298 | { |
| 299 | shandle = start_stab (dhandle, abfd, FALSE, syms, symcount); |
| 300 | if (shandle == NULL) |
| 301 | return FALSE; |
| 302 | } |
| 303 | |
| 304 | *pfound = TRUE; |
| 305 | |
| 306 | s = i.name; |
| 307 | if (s == NULL || strlen (s) < 1) |
| 308 | return FALSE; |
| 309 | f = NULL; |
| 310 | |
| 311 | while (strlen (s) > 0 |
| 312 | && s[strlen (s) - 1] == '\\' |
| 313 | && ps + 1 < symend) |
| 314 | { |
| 315 | char *sc, *n; |
| 316 | |
| 317 | ++ps; |
| 318 | sc = xstrdup (s); |
| 319 | sc[strlen (sc) - 1] = '\0'; |
| 320 | n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL); |
| 321 | free (sc); |
| 322 | if (f != NULL) |
| 323 | free (f); |
| 324 | f = n; |
| 325 | s = n; |
| 326 | } |
| 327 | |
| 328 | save_stab (i.stab_type, i.stab_desc, i.value, s); |
| 329 | |
| 330 | if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc, |
| 331 | i.value, s)) |
| 332 | { |
| 333 | stab_context (); |
| 334 | free_saved_stabs (); |
| 335 | return FALSE; |
| 336 | } |
| 337 | |
| 338 | /* Don't free f, since I think the stabs code expects |
| 339 | strings to hang around. This should be straightened out. |
| 340 | FIXME. */ |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | free_saved_stabs (); |
| 345 | |
| 346 | if (shandle != NULL) |
| 347 | { |
| 348 | if (! finish_stab (dhandle, shandle)) |
| 349 | return FALSE; |
| 350 | } |
| 351 | |
| 352 | return TRUE; |
| 353 | } |
| 354 | \f |
| 355 | /* Record stabs strings, so that we can give some context for errors. */ |
| 356 | |
| 357 | #define SAVE_STABS_COUNT (16) |
| 358 | |
| 359 | struct saved_stab |
| 360 | { |
| 361 | int type; |
| 362 | int desc; |
| 363 | bfd_vma value; |
| 364 | char *string; |
| 365 | }; |
| 366 | |
| 367 | static struct saved_stab saved_stabs[SAVE_STABS_COUNT]; |
| 368 | static int saved_stabs_index; |
| 369 | |
| 370 | /* Save a stabs string. */ |
| 371 | |
| 372 | static void |
| 373 | save_stab (int type, int desc, bfd_vma value, const char *string) |
| 374 | { |
| 375 | if (saved_stabs[saved_stabs_index].string != NULL) |
| 376 | free (saved_stabs[saved_stabs_index].string); |
| 377 | saved_stabs[saved_stabs_index].type = type; |
| 378 | saved_stabs[saved_stabs_index].desc = desc; |
| 379 | saved_stabs[saved_stabs_index].value = value; |
| 380 | saved_stabs[saved_stabs_index].string = xstrdup (string); |
| 381 | saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT; |
| 382 | } |
| 383 | |
| 384 | /* Provide context for an error. */ |
| 385 | |
| 386 | static void |
| 387 | stab_context (void) |
| 388 | { |
| 389 | int i; |
| 390 | |
| 391 | fprintf (stderr, _("Last stabs entries before error:\n")); |
| 392 | fprintf (stderr, "n_type n_desc n_value string\n"); |
| 393 | |
| 394 | i = saved_stabs_index; |
| 395 | do |
| 396 | { |
| 397 | struct saved_stab *stabp; |
| 398 | |
| 399 | stabp = saved_stabs + i; |
| 400 | if (stabp->string != NULL) |
| 401 | { |
| 402 | const char *s; |
| 403 | |
| 404 | s = bfd_get_stab_name (stabp->type); |
| 405 | if (s != NULL) |
| 406 | fprintf (stderr, "%-6s", s); |
| 407 | else if (stabp->type == 0) |
| 408 | fprintf (stderr, "HdrSym"); |
| 409 | else |
| 410 | fprintf (stderr, "%-6d", stabp->type); |
| 411 | fprintf (stderr, " %-6d ", stabp->desc); |
| 412 | fprintf_vma (stderr, stabp->value); |
| 413 | if (stabp->type != 0) |
| 414 | fprintf (stderr, " %s", stabp->string); |
| 415 | fprintf (stderr, "\n"); |
| 416 | } |
| 417 | i = (i + 1) % SAVE_STABS_COUNT; |
| 418 | } |
| 419 | while (i != saved_stabs_index); |
| 420 | } |
| 421 | |
| 422 | /* Free the saved stab strings. */ |
| 423 | |
| 424 | static void |
| 425 | free_saved_stabs (void) |
| 426 | { |
| 427 | int i; |
| 428 | |
| 429 | for (i = 0; i < SAVE_STABS_COUNT; i++) |
| 430 | { |
| 431 | if (saved_stabs[i].string != NULL) |
| 432 | { |
| 433 | free (saved_stabs[i].string); |
| 434 | saved_stabs[i].string = NULL; |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | saved_stabs_index = 0; |
| 439 | } |