1 /* GDB routines for manipulating the minimal symbol tables. 2 Copyright (C) 1992-2004, 2007-2012 Free Software Foundation, Inc. 3 Contributed by Cygnus Support, using pieces from other GDB modules. 4 5 This file is part of GDB. 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, see <http://www.gnu.org/licenses/>. */ 19 20 21 /* This file contains support routines for creating, manipulating, and 22 destroying minimal symbol tables. 23 24 Minimal symbol tables are used to hold some very basic information about 25 all defined global symbols (text, data, bss, abs, etc). The only two 26 required pieces of information are the symbol's name and the address 27 associated with that symbol. 28 29 In many cases, even if a file was compiled with no special options for 30 debugging at all, as long as was not stripped it will contain sufficient 31 information to build useful minimal symbol tables using this structure. 32 33 Even when a file contains enough debugging information to build a full 34 symbol table, these minimal symbols are still useful for quickly mapping 35 between names and addresses, and vice versa. They are also sometimes used 36 to figure out what full symbol table entries need to be read in. */ 37 38 39 #include "defs.h" 40 #include <ctype.h> 41 #include "gdb_string.h" 42 #include "symtab.h" 43 #include "bfd.h" 44 #include "filenames.h" 45 #include "symfile.h" 46 #include "objfiles.h" 47 #include "demangle.h" 48 #include "value.h" 49 #include "cp-abi.h" 50 #include "target.h" 51 #include "cp-support.h" 52 #include "language.h" 53 54 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. 55 At the end, copy them all into one newly allocated location on an objfile's 56 symbol obstack. */ 57 58 #define BUNCH_SIZE 127 59 60 struct msym_bunch 61 { 62 struct msym_bunch *next; 63 struct minimal_symbol contents[BUNCH_SIZE]; 64 }; 65 66 /* Bunch currently being filled up. 67 The next field points to chain of filled bunches. */ 68 69 static struct msym_bunch *msym_bunch; 70 71 /* Number of slots filled in current bunch. */ 72 73 static int msym_bunch_index; 74 75 /* Total number of minimal symbols recorded so far for the objfile. */ 76 77 static int msym_count; 78 79 /* Compute a hash code based using the same criteria as `strcmp_iw'. */ 80 81 unsigned int 82 msymbol_hash_iw (const char *string) 83 { 84 unsigned int hash = 0; 85 86 while (*string && *string != '(') 87 { 88 while (isspace (*string)) 89 ++string; 90 if (*string && *string != '(') 91 { 92 hash = SYMBOL_HASH_NEXT (hash, *string); 93 ++string; 94 } 95 } 96 return hash; 97 } 98 99 /* Compute a hash code for a string. */ 100 101 unsigned int 102 msymbol_hash (const char *string) 103 { 104 unsigned int hash = 0; 105 106 for (; *string; ++string) 107 hash = SYMBOL_HASH_NEXT (hash, *string); 108 return hash; 109 } 110 111 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */ 112 void 113 add_minsym_to_hash_table (struct minimal_symbol *sym, 114 struct minimal_symbol **table) 115 { 116 if (sym->hash_next == NULL) 117 { 118 unsigned int hash 119 = msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE; 120 121 sym->hash_next = table[hash]; 122 table[hash] = sym; 123 } 124 } 125 126 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table, 127 TABLE. */ 128 static void 129 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym, 130 struct minimal_symbol **table) 131 { 132 if (sym->demangled_hash_next == NULL) 133 { 134 unsigned int hash = msymbol_hash_iw (SYMBOL_SEARCH_NAME (sym)) 135 % MINIMAL_SYMBOL_HASH_SIZE; 136 137 sym->demangled_hash_next = table[hash]; 138 table[hash] = sym; 139 } 140 } 141 142 143 /* Return OBJFILE where minimal symbol SYM is defined. */ 144 struct objfile * 145 msymbol_objfile (struct minimal_symbol *sym) 146 { 147 struct objfile *objf; 148 struct minimal_symbol *tsym; 149 150 unsigned int hash 151 = msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE; 152 153 for (objf = object_files; objf; objf = objf->next) 154 for (tsym = objf->msymbol_hash[hash]; tsym; tsym = tsym->hash_next) 155 if (tsym == sym) 156 return objf; 157 158 /* We should always be able to find the objfile ... */ 159 internal_error (__FILE__, __LINE__, _("failed internal consistency check")); 160 } 161 162 163 /* Look through all the current minimal symbol tables and find the 164 first minimal symbol that matches NAME. If OBJF is non-NULL, limit 165 the search to that objfile. If SFILE is non-NULL, the only file-scope 166 symbols considered will be from that source file (global symbols are 167 still preferred). Returns a pointer to the minimal symbol that 168 matches, or NULL if no match is found. 169 170 Note: One instance where there may be duplicate minimal symbols with 171 the same name is when the symbol tables for a shared library and the 172 symbol tables for an executable contain global symbols with the same 173 names (the dynamic linker deals with the duplication). 174 175 It's also possible to have minimal symbols with different mangled 176 names, but identical demangled names. For example, the GNU C++ v3 177 ABI requires the generation of two (or perhaps three) copies of 178 constructor functions --- "in-charge", "not-in-charge", and 179 "allocate" copies; destructors may be duplicated as well. 180 Obviously, there must be distinct mangled names for each of these, 181 but the demangled names are all the same: S::S or S::~S. */ 182 183 struct minimal_symbol * 184 lookup_minimal_symbol (const char *name, const char *sfile, 185 struct objfile *objf) 186 { 187 struct objfile *objfile; 188 struct minimal_symbol *msymbol; 189 struct minimal_symbol *found_symbol = NULL; 190 struct minimal_symbol *found_file_symbol = NULL; 191 struct minimal_symbol *trampoline_symbol = NULL; 192 193 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 194 unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE; 195 196 int needtofreename = 0; 197 const char *modified_name; 198 199 if (sfile != NULL) 200 sfile = lbasename (sfile); 201 202 /* For C++, canonicalize the input name. */ 203 modified_name = name; 204 if (current_language->la_language == language_cplus) 205 { 206 char *cname = cp_canonicalize_string (name); 207 208 if (cname) 209 { 210 modified_name = cname; 211 needtofreename = 1; 212 } 213 } 214 215 for (objfile = object_files; 216 objfile != NULL && found_symbol == NULL; 217 objfile = objfile->next) 218 { 219 if (objf == NULL || objf == objfile 220 || objf == objfile->separate_debug_objfile_backlink) 221 { 222 /* Do two passes: the first over the ordinary hash table, 223 and the second over the demangled hash table. */ 224 int pass; 225 226 for (pass = 1; pass <= 2 && found_symbol == NULL; pass++) 227 { 228 /* Select hash list according to pass. */ 229 if (pass == 1) 230 msymbol = objfile->msymbol_hash[hash]; 231 else 232 msymbol = objfile->msymbol_demangled_hash[dem_hash]; 233 234 while (msymbol != NULL && found_symbol == NULL) 235 { 236 int match; 237 238 if (pass == 1) 239 { 240 int (*cmp) (const char *, const char *); 241 242 cmp = (case_sensitivity == case_sensitive_on 243 ? strcmp : strcasecmp); 244 match = cmp (SYMBOL_LINKAGE_NAME (msymbol), 245 modified_name) == 0; 246 } 247 else 248 { 249 /* The function respects CASE_SENSITIVITY. */ 250 match = SYMBOL_MATCHES_SEARCH_NAME (msymbol, 251 modified_name); 252 } 253 254 if (match) 255 { 256 switch (MSYMBOL_TYPE (msymbol)) 257 { 258 case mst_file_text: 259 case mst_file_data: 260 case mst_file_bss: 261 if (sfile == NULL 262 || filename_cmp (msymbol->filename, sfile) == 0) 263 found_file_symbol = msymbol; 264 break; 265 266 case mst_solib_trampoline: 267 268 /* If a trampoline symbol is found, we prefer to 269 keep looking for the *real* symbol. If the 270 actual symbol is not found, then we'll use the 271 trampoline entry. */ 272 if (trampoline_symbol == NULL) 273 trampoline_symbol = msymbol; 274 break; 275 276 case mst_unknown: 277 default: 278 found_symbol = msymbol; 279 break; 280 } 281 } 282 283 /* Find the next symbol on the hash chain. */ 284 if (pass == 1) 285 msymbol = msymbol->hash_next; 286 else 287 msymbol = msymbol->demangled_hash_next; 288 } 289 } 290 } 291 } 292 293 if (needtofreename) 294 xfree ((void *) modified_name); 295 296 /* External symbols are best. */ 297 if (found_symbol) 298 return found_symbol; 299 300 /* File-local symbols are next best. */ 301 if (found_file_symbol) 302 return found_file_symbol; 303 304 /* Symbols for shared library trampolines are next best. */ 305 if (trampoline_symbol) 306 return trampoline_symbol; 307 308 return NULL; 309 } 310 311 /* Iterate over all the minimal symbols in the objfile OBJF which 312 match NAME. Both the ordinary and demangled names of each symbol 313 are considered. The caller is responsible for canonicalizing NAME, 314 should that need to be done. 315 316 For each matching symbol, CALLBACK is called with the symbol and 317 USER_DATA as arguments. */ 318 319 void 320 iterate_over_minimal_symbols (struct objfile *objf, const char *name, 321 void (*callback) (struct minimal_symbol *, 322 void *), 323 void *user_data) 324 { 325 unsigned int hash; 326 struct minimal_symbol *iter; 327 int (*cmp) (const char *, const char *); 328 329 /* The first pass is over the ordinary hash table. */ 330 hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 331 iter = objf->msymbol_hash[hash]; 332 cmp = (case_sensitivity == case_sensitive_on ? strcmp : strcasecmp); 333 while (iter) 334 { 335 if (cmp (SYMBOL_LINKAGE_NAME (iter), name) == 0) 336 (*callback) (iter, user_data); 337 iter = iter->hash_next; 338 } 339 340 /* The second pass is over the demangled table. */ 341 hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE; 342 iter = objf->msymbol_demangled_hash[hash]; 343 while (iter) 344 { 345 if (SYMBOL_MATCHES_SEARCH_NAME (iter, name)) 346 (*callback) (iter, user_data); 347 iter = iter->demangled_hash_next; 348 } 349 } 350 351 /* Look through all the current minimal symbol tables and find the 352 first minimal symbol that matches NAME and has text type. If OBJF 353 is non-NULL, limit the search to that objfile. Returns a pointer 354 to the minimal symbol that matches, or NULL if no match is found. 355 356 This function only searches the mangled (linkage) names. */ 357 358 struct minimal_symbol * 359 lookup_minimal_symbol_text (const char *name, struct objfile *objf) 360 { 361 struct objfile *objfile; 362 struct minimal_symbol *msymbol; 363 struct minimal_symbol *found_symbol = NULL; 364 struct minimal_symbol *found_file_symbol = NULL; 365 366 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 367 368 for (objfile = object_files; 369 objfile != NULL && found_symbol == NULL; 370 objfile = objfile->next) 371 { 372 if (objf == NULL || objf == objfile 373 || objf == objfile->separate_debug_objfile_backlink) 374 { 375 for (msymbol = objfile->msymbol_hash[hash]; 376 msymbol != NULL && found_symbol == NULL; 377 msymbol = msymbol->hash_next) 378 { 379 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 && 380 (MSYMBOL_TYPE (msymbol) == mst_text 381 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc 382 || MSYMBOL_TYPE (msymbol) == mst_file_text)) 383 { 384 switch (MSYMBOL_TYPE (msymbol)) 385 { 386 case mst_file_text: 387 found_file_symbol = msymbol; 388 break; 389 default: 390 found_symbol = msymbol; 391 break; 392 } 393 } 394 } 395 } 396 } 397 /* External symbols are best. */ 398 if (found_symbol) 399 return found_symbol; 400 401 /* File-local symbols are next best. */ 402 if (found_file_symbol) 403 return found_file_symbol; 404 405 return NULL; 406 } 407 408 /* Look through all the current minimal symbol tables and find the 409 first minimal symbol that matches NAME and PC. If OBJF is non-NULL, 410 limit the search to that objfile. Returns a pointer to the minimal 411 symbol that matches, or NULL if no match is found. */ 412 413 struct minimal_symbol * 414 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name, 415 struct objfile *objf) 416 { 417 struct objfile *objfile; 418 struct minimal_symbol *msymbol; 419 420 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 421 422 for (objfile = object_files; 423 objfile != NULL; 424 objfile = objfile->next) 425 { 426 if (objf == NULL || objf == objfile 427 || objf == objfile->separate_debug_objfile_backlink) 428 { 429 for (msymbol = objfile->msymbol_hash[hash]; 430 msymbol != NULL; 431 msymbol = msymbol->hash_next) 432 { 433 if (SYMBOL_VALUE_ADDRESS (msymbol) == pc 434 && strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0) 435 return msymbol; 436 } 437 } 438 } 439 440 return NULL; 441 } 442 443 /* Look through all the current minimal symbol tables and find the 444 first minimal symbol that matches NAME and is a solib trampoline. 445 If OBJF is non-NULL, limit the search to that objfile. Returns a 446 pointer to the minimal symbol that matches, or NULL if no match is 447 found. 448 449 This function only searches the mangled (linkage) names. */ 450 451 struct minimal_symbol * 452 lookup_minimal_symbol_solib_trampoline (const char *name, 453 struct objfile *objf) 454 { 455 struct objfile *objfile; 456 struct minimal_symbol *msymbol; 457 struct minimal_symbol *found_symbol = NULL; 458 459 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 460 461 for (objfile = object_files; 462 objfile != NULL && found_symbol == NULL; 463 objfile = objfile->next) 464 { 465 if (objf == NULL || objf == objfile 466 || objf == objfile->separate_debug_objfile_backlink) 467 { 468 for (msymbol = objfile->msymbol_hash[hash]; 469 msymbol != NULL && found_symbol == NULL; 470 msymbol = msymbol->hash_next) 471 { 472 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 && 473 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) 474 return msymbol; 475 } 476 } 477 } 478 479 return NULL; 480 } 481 482 /* Search through the minimal symbol table for each objfile and find 483 the symbol whose address is the largest address that is still less 484 than or equal to PC, and matches SECTION (which is not NULL). 485 Returns a pointer to the minimal symbol if such a symbol is found, 486 or NULL if PC is not in a suitable range. 487 Note that we need to look through ALL the minimal symbol tables 488 before deciding on the symbol that comes closest to the specified PC. 489 This is because objfiles can overlap, for example objfile A has .text 490 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and 491 .data at 0x40048. 492 493 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when 494 there are text and trampoline symbols at the same address. 495 Otherwise prefer mst_text symbols. */ 496 497 static struct minimal_symbol * 498 lookup_minimal_symbol_by_pc_section_1 (CORE_ADDR pc, 499 struct obj_section *section, 500 int want_trampoline) 501 { 502 int lo; 503 int hi; 504 int new; 505 struct objfile *objfile; 506 struct minimal_symbol *msymbol; 507 struct minimal_symbol *best_symbol = NULL; 508 enum minimal_symbol_type want_type, other_type; 509 510 want_type = want_trampoline ? mst_solib_trampoline : mst_text; 511 other_type = want_trampoline ? mst_text : mst_solib_trampoline; 512 513 /* We can not require the symbol found to be in section, because 514 e.g. IRIX 6.5 mdebug relies on this code returning an absolute 515 symbol - but find_pc_section won't return an absolute section and 516 hence the code below would skip over absolute symbols. We can 517 still take advantage of the call to find_pc_section, though - the 518 object file still must match. In case we have separate debug 519 files, search both the file and its separate debug file. There's 520 no telling which one will have the minimal symbols. */ 521 522 gdb_assert (section != NULL); 523 524 for (objfile = section->objfile; 525 objfile != NULL; 526 objfile = objfile_separate_debug_iterate (section->objfile, objfile)) 527 { 528 /* If this objfile has a minimal symbol table, go search it using 529 a binary search. Note that a minimal symbol table always consists 530 of at least two symbols, a "real" symbol and the terminating 531 "null symbol". If there are no real symbols, then there is no 532 minimal symbol table at all. */ 533 534 if (objfile->minimal_symbol_count > 0) 535 { 536 int best_zero_sized = -1; 537 538 msymbol = objfile->msymbols; 539 lo = 0; 540 hi = objfile->minimal_symbol_count - 1; 541 542 /* This code assumes that the minimal symbols are sorted by 543 ascending address values. If the pc value is greater than or 544 equal to the first symbol's address, then some symbol in this 545 minimal symbol table is a suitable candidate for being the 546 "best" symbol. This includes the last real symbol, for cases 547 where the pc value is larger than any address in this vector. 548 549 By iterating until the address associated with the current 550 hi index (the endpoint of the test interval) is less than 551 or equal to the desired pc value, we accomplish two things: 552 (1) the case where the pc value is larger than any minimal 553 symbol address is trivially solved, (2) the address associated 554 with the hi index is always the one we want when the interation 555 terminates. In essence, we are iterating the test interval 556 down until the pc value is pushed out of it from the high end. 557 558 Warning: this code is trickier than it would appear at first. */ 559 560 /* Should also require that pc is <= end of objfile. FIXME! */ 561 if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo])) 562 { 563 while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc) 564 { 565 /* pc is still strictly less than highest address. */ 566 /* Note "new" will always be >= lo. */ 567 new = (lo + hi) / 2; 568 if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) || 569 (lo == new)) 570 { 571 hi = new; 572 } 573 else 574 { 575 lo = new; 576 } 577 } 578 579 /* If we have multiple symbols at the same address, we want 580 hi to point to the last one. That way we can find the 581 right symbol if it has an index greater than hi. */ 582 while (hi < objfile->minimal_symbol_count - 1 583 && (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) 584 == SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1]))) 585 hi++; 586 587 /* Skip various undesirable symbols. */ 588 while (hi >= 0) 589 { 590 /* Skip any absolute symbols. This is apparently 591 what adb and dbx do, and is needed for the CM-5. 592 There are two known possible problems: (1) on 593 ELF, apparently end, edata, etc. are absolute. 594 Not sure ignoring them here is a big deal, but if 595 we want to use them, the fix would go in 596 elfread.c. (2) I think shared library entry 597 points on the NeXT are absolute. If we want 598 special handling for this it probably should be 599 triggered by a special mst_abs_or_lib or some 600 such. */ 601 602 if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs) 603 { 604 hi--; 605 continue; 606 } 607 608 /* If SECTION was specified, skip any symbol from 609 wrong section. */ 610 if (section 611 /* Some types of debug info, such as COFF, 612 don't fill the bfd_section member, so don't 613 throw away symbols on those platforms. */ 614 && SYMBOL_OBJ_SECTION (&msymbol[hi]) != NULL 615 && (!matching_obj_sections 616 (SYMBOL_OBJ_SECTION (&msymbol[hi]), section))) 617 { 618 hi--; 619 continue; 620 } 621 622 /* If we are looking for a trampoline and this is a 623 text symbol, or the other way around, check the 624 preceding symbol too. If they are otherwise 625 identical prefer that one. */ 626 if (hi > 0 627 && MSYMBOL_TYPE (&msymbol[hi]) == other_type 628 && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type 629 && (MSYMBOL_SIZE (&msymbol[hi]) 630 == MSYMBOL_SIZE (&msymbol[hi - 1])) 631 && (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) 632 == SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1])) 633 && (SYMBOL_OBJ_SECTION (&msymbol[hi]) 634 == SYMBOL_OBJ_SECTION (&msymbol[hi - 1]))) 635 { 636 hi--; 637 continue; 638 } 639 640 /* If the minimal symbol has a zero size, save it 641 but keep scanning backwards looking for one with 642 a non-zero size. A zero size may mean that the 643 symbol isn't an object or function (e.g. a 644 label), or it may just mean that the size was not 645 specified. */ 646 if (MSYMBOL_SIZE (&msymbol[hi]) == 0 647 && best_zero_sized == -1) 648 { 649 best_zero_sized = hi; 650 hi--; 651 continue; 652 } 653 654 /* If we are past the end of the current symbol, try 655 the previous symbol if it has a larger overlapping 656 size. This happens on i686-pc-linux-gnu with glibc; 657 the nocancel variants of system calls are inside 658 the cancellable variants, but both have sizes. */ 659 if (hi > 0 660 && MSYMBOL_SIZE (&msymbol[hi]) != 0 661 && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) 662 + MSYMBOL_SIZE (&msymbol[hi])) 663 && pc < (SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1]) 664 + MSYMBOL_SIZE (&msymbol[hi - 1]))) 665 { 666 hi--; 667 continue; 668 } 669 670 /* Otherwise, this symbol must be as good as we're going 671 to get. */ 672 break; 673 } 674 675 /* If HI has a zero size, and best_zero_sized is set, 676 then we had two or more zero-sized symbols; prefer 677 the first one we found (which may have a higher 678 address). Also, if we ran off the end, be sure 679 to back up. */ 680 if (best_zero_sized != -1 681 && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0)) 682 hi = best_zero_sized; 683 684 /* If the minimal symbol has a non-zero size, and this 685 PC appears to be outside the symbol's contents, then 686 refuse to use this symbol. If we found a zero-sized 687 symbol with an address greater than this symbol's, 688 use that instead. We assume that if symbols have 689 specified sizes, they do not overlap. */ 690 691 if (hi >= 0 692 && MSYMBOL_SIZE (&msymbol[hi]) != 0 693 && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) 694 + MSYMBOL_SIZE (&msymbol[hi]))) 695 { 696 if (best_zero_sized != -1) 697 hi = best_zero_sized; 698 else 699 /* Go on to the next object file. */ 700 continue; 701 } 702 703 /* The minimal symbol indexed by hi now is the best one in this 704 objfile's minimal symbol table. See if it is the best one 705 overall. */ 706 707 if (hi >= 0 708 && ((best_symbol == NULL) || 709 (SYMBOL_VALUE_ADDRESS (best_symbol) < 710 SYMBOL_VALUE_ADDRESS (&msymbol[hi])))) 711 { 712 best_symbol = &msymbol[hi]; 713 } 714 } 715 } 716 } 717 return (best_symbol); 718 } 719 720 struct minimal_symbol * 721 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, struct obj_section *section) 722 { 723 if (section == NULL) 724 { 725 /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to 726 force the section but that (well unless you're doing overlay 727 debugging) always returns NULL making the call somewhat useless. */ 728 section = find_pc_section (pc); 729 if (section == NULL) 730 return NULL; 731 } 732 return lookup_minimal_symbol_by_pc_section_1 (pc, section, 0); 733 } 734 735 /* Backward compatibility: search through the minimal symbol table 736 for a matching PC (no section given). */ 737 738 struct minimal_symbol * 739 lookup_minimal_symbol_by_pc (CORE_ADDR pc) 740 { 741 return lookup_minimal_symbol_by_pc_section (pc, NULL); 742 } 743 744 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */ 745 746 int 747 in_gnu_ifunc_stub (CORE_ADDR pc) 748 { 749 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc); 750 751 return msymbol && MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc; 752 } 753 754 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */ 755 756 static CORE_ADDR 757 stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc) 758 { 759 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without " 760 "the ELF support compiled in."), 761 paddress (gdbarch, pc)); 762 } 763 764 /* See elf_gnu_ifunc_resolve_name for its real implementation. */ 765 766 static int 767 stub_gnu_ifunc_resolve_name (const char *function_name, 768 CORE_ADDR *function_address_p) 769 { 770 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without " 771 "the ELF support compiled in."), 772 function_name); 773 } 774 775 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */ 776 777 static void 778 stub_gnu_ifunc_resolver_stop (struct breakpoint *b) 779 { 780 internal_error (__FILE__, __LINE__, 781 _("elf_gnu_ifunc_resolver_stop cannot be reached.")); 782 } 783 784 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */ 785 786 static void 787 stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b) 788 { 789 internal_error (__FILE__, __LINE__, 790 _("elf_gnu_ifunc_resolver_return_stop cannot be reached.")); 791 } 792 793 /* See elf_gnu_ifunc_fns for its real implementation. */ 794 795 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns = 796 { 797 stub_gnu_ifunc_resolve_addr, 798 stub_gnu_ifunc_resolve_name, 799 stub_gnu_ifunc_resolver_stop, 800 stub_gnu_ifunc_resolver_return_stop, 801 }; 802 803 /* A placeholder for &elf_gnu_ifunc_fns. */ 804 805 const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns; 806 807 /* Find the minimal symbol named NAME, and return both the minsym 808 struct and its objfile. This only checks the linkage name. Sets 809 *OBJFILE_P and returns the minimal symbol, if it is found. If it 810 is not found, returns NULL. */ 811 812 struct minimal_symbol * 813 lookup_minimal_symbol_and_objfile (const char *name, 814 struct objfile **objfile_p) 815 { 816 struct objfile *objfile; 817 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; 818 819 ALL_OBJFILES (objfile) 820 { 821 struct minimal_symbol *msym; 822 823 for (msym = objfile->msymbol_hash[hash]; 824 msym != NULL; 825 msym = msym->hash_next) 826 { 827 if (strcmp (SYMBOL_LINKAGE_NAME (msym), name) == 0) 828 { 829 *objfile_p = objfile; 830 return msym; 831 } 832 } 833 } 834 835 return 0; 836 } 837 838 839 /* Return leading symbol character for a BFD. If BFD is NULL, 840 return the leading symbol character from the main objfile. */ 841 842 static int get_symbol_leading_char (bfd *); 843 844 static int 845 get_symbol_leading_char (bfd *abfd) 846 { 847 if (abfd != NULL) 848 return bfd_get_symbol_leading_char (abfd); 849 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL) 850 return bfd_get_symbol_leading_char (symfile_objfile->obfd); 851 return 0; 852 } 853 854 /* Prepare to start collecting minimal symbols. Note that presetting 855 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal 856 symbol to allocate the memory for the first bunch. */ 857 858 void 859 init_minimal_symbol_collection (void) 860 { 861 msym_count = 0; 862 msym_bunch = NULL; 863 msym_bunch_index = BUNCH_SIZE; 864 } 865 866 void 867 prim_record_minimal_symbol (const char *name, CORE_ADDR address, 868 enum minimal_symbol_type ms_type, 869 struct objfile *objfile) 870 { 871 int section; 872 873 switch (ms_type) 874 { 875 case mst_text: 876 case mst_text_gnu_ifunc: 877 case mst_file_text: 878 case mst_solib_trampoline: 879 section = SECT_OFF_TEXT (objfile); 880 break; 881 case mst_data: 882 case mst_file_data: 883 section = SECT_OFF_DATA (objfile); 884 break; 885 case mst_bss: 886 case mst_file_bss: 887 section = SECT_OFF_BSS (objfile); 888 break; 889 default: 890 section = -1; 891 } 892 893 prim_record_minimal_symbol_and_info (name, address, ms_type, 894 section, NULL, objfile); 895 } 896 897 /* Record a minimal symbol in the msym bunches. Returns the symbol 898 newly created. */ 899 900 struct minimal_symbol * 901 prim_record_minimal_symbol_full (const char *name, int name_len, int copy_name, 902 CORE_ADDR address, 903 enum minimal_symbol_type ms_type, 904 int section, 905 asection *bfd_section, 906 struct objfile *objfile) 907 { 908 struct obj_section *obj_section; 909 struct msym_bunch *new; 910 struct minimal_symbol *msymbol; 911 912 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into 913 the minimal symbols, because if there is also another symbol 914 at the same address (e.g. the first function of the file), 915 lookup_minimal_symbol_by_pc would have no way of getting the 916 right one. */ 917 if (ms_type == mst_file_text && name[0] == 'g' 918 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0 919 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0)) 920 return (NULL); 921 922 /* It's safe to strip the leading char here once, since the name 923 is also stored stripped in the minimal symbol table. */ 924 if (name[0] == get_symbol_leading_char (objfile->obfd)) 925 { 926 ++name; 927 --name_len; 928 } 929 930 if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0) 931 return (NULL); 932 933 if (msym_bunch_index == BUNCH_SIZE) 934 { 935 new = XCALLOC (1, struct msym_bunch); 936 msym_bunch_index = 0; 937 new->next = msym_bunch; 938 msym_bunch = new; 939 } 940 msymbol = &msym_bunch->contents[msym_bunch_index]; 941 SYMBOL_SET_LANGUAGE (msymbol, language_auto); 942 SYMBOL_SET_NAMES (msymbol, name, name_len, copy_name, objfile); 943 944 SYMBOL_VALUE_ADDRESS (msymbol) = address; 945 SYMBOL_SECTION (msymbol) = section; 946 SYMBOL_OBJ_SECTION (msymbol) = NULL; 947 948 /* Find obj_section corresponding to bfd_section. */ 949 if (bfd_section) 950 ALL_OBJFILE_OSECTIONS (objfile, obj_section) 951 { 952 if (obj_section->the_bfd_section == bfd_section) 953 { 954 SYMBOL_OBJ_SECTION (msymbol) = obj_section; 955 break; 956 } 957 } 958 959 MSYMBOL_TYPE (msymbol) = ms_type; 960 MSYMBOL_TARGET_FLAG_1 (msymbol) = 0; 961 MSYMBOL_TARGET_FLAG_2 (msymbol) = 0; 962 MSYMBOL_SIZE (msymbol) = 0; 963 964 /* The hash pointers must be cleared! If they're not, 965 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */ 966 msymbol->hash_next = NULL; 967 msymbol->demangled_hash_next = NULL; 968 969 msym_bunch_index++; 970 msym_count++; 971 OBJSTAT (objfile, n_minsyms++); 972 return msymbol; 973 } 974 975 /* Record a minimal symbol in the msym bunches. Returns the symbol 976 newly created. */ 977 978 struct minimal_symbol * 979 prim_record_minimal_symbol_and_info (const char *name, CORE_ADDR address, 980 enum minimal_symbol_type ms_type, 981 int section, 982 asection *bfd_section, 983 struct objfile *objfile) 984 { 985 return prim_record_minimal_symbol_full (name, strlen (name), 1, 986 address, ms_type, section, 987 bfd_section, objfile); 988 } 989 990 /* Compare two minimal symbols by address and return a signed result based 991 on unsigned comparisons, so that we sort into unsigned numeric order. 992 Within groups with the same address, sort by name. */ 993 994 static int 995 compare_minimal_symbols (const void *fn1p, const void *fn2p) 996 { 997 const struct minimal_symbol *fn1; 998 const struct minimal_symbol *fn2; 999 1000 fn1 = (const struct minimal_symbol *) fn1p; 1001 fn2 = (const struct minimal_symbol *) fn2p; 1002 1003 if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2)) 1004 { 1005 return (-1); /* addr 1 is less than addr 2. */ 1006 } 1007 else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2)) 1008 { 1009 return (1); /* addr 1 is greater than addr 2. */ 1010 } 1011 else 1012 /* addrs are equal: sort by name */ 1013 { 1014 char *name1 = SYMBOL_LINKAGE_NAME (fn1); 1015 char *name2 = SYMBOL_LINKAGE_NAME (fn2); 1016 1017 if (name1 && name2) /* both have names */ 1018 return strcmp (name1, name2); 1019 else if (name2) 1020 return 1; /* fn1 has no name, so it is "less". */ 1021 else if (name1) /* fn2 has no name, so it is "less". */ 1022 return -1; 1023 else 1024 return (0); /* Neither has a name, so they're equal. */ 1025 } 1026 } 1027 1028 /* Discard the currently collected minimal symbols, if any. If we wish 1029 to save them for later use, we must have already copied them somewhere 1030 else before calling this function. 1031 1032 FIXME: We could allocate the minimal symbol bunches on their own 1033 obstack and then simply blow the obstack away when we are done with 1034 it. Is it worth the extra trouble though? */ 1035 1036 static void 1037 do_discard_minimal_symbols_cleanup (void *arg) 1038 { 1039 struct msym_bunch *next; 1040 1041 while (msym_bunch != NULL) 1042 { 1043 next = msym_bunch->next; 1044 xfree (msym_bunch); 1045 msym_bunch = next; 1046 } 1047 } 1048 1049 struct cleanup * 1050 make_cleanup_discard_minimal_symbols (void) 1051 { 1052 return make_cleanup (do_discard_minimal_symbols_cleanup, 0); 1053 } 1054 1055 1056 1057 /* Compact duplicate entries out of a minimal symbol table by walking 1058 through the table and compacting out entries with duplicate addresses 1059 and matching names. Return the number of entries remaining. 1060 1061 On entry, the table resides between msymbol[0] and msymbol[mcount]. 1062 On exit, it resides between msymbol[0] and msymbol[result_count]. 1063 1064 When files contain multiple sources of symbol information, it is 1065 possible for the minimal symbol table to contain many duplicate entries. 1066 As an example, SVR4 systems use ELF formatted object files, which 1067 usually contain at least two different types of symbol tables (a 1068 standard ELF one and a smaller dynamic linking table), as well as 1069 DWARF debugging information for files compiled with -g. 1070 1071 Without compacting, the minimal symbol table for gdb itself contains 1072 over a 1000 duplicates, about a third of the total table size. Aside 1073 from the potential trap of not noticing that two successive entries 1074 identify the same location, this duplication impacts the time required 1075 to linearly scan the table, which is done in a number of places. So we 1076 just do one linear scan here and toss out the duplicates. 1077 1078 Note that we are not concerned here about recovering the space that 1079 is potentially freed up, because the strings themselves are allocated 1080 on the objfile_obstack, and will get automatically freed when the symbol 1081 table is freed. The caller can free up the unused minimal symbols at 1082 the end of the compacted region if their allocation strategy allows it. 1083 1084 Also note we only go up to the next to last entry within the loop 1085 and then copy the last entry explicitly after the loop terminates. 1086 1087 Since the different sources of information for each symbol may 1088 have different levels of "completeness", we may have duplicates 1089 that have one entry with type "mst_unknown" and the other with a 1090 known type. So if the one we are leaving alone has type mst_unknown, 1091 overwrite its type with the type from the one we are compacting out. */ 1092 1093 static int 1094 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount, 1095 struct objfile *objfile) 1096 { 1097 struct minimal_symbol *copyfrom; 1098 struct minimal_symbol *copyto; 1099 1100 if (mcount > 0) 1101 { 1102 copyfrom = copyto = msymbol; 1103 while (copyfrom < msymbol + mcount - 1) 1104 { 1105 if (SYMBOL_VALUE_ADDRESS (copyfrom) 1106 == SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) 1107 && strcmp (SYMBOL_LINKAGE_NAME (copyfrom), 1108 SYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0) 1109 { 1110 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown) 1111 { 1112 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom); 1113 } 1114 copyfrom++; 1115 } 1116 else 1117 *copyto++ = *copyfrom++; 1118 } 1119 *copyto++ = *copyfrom++; 1120 mcount = copyto - msymbol; 1121 } 1122 return (mcount); 1123 } 1124 1125 /* Build (or rebuild) the minimal symbol hash tables. This is necessary 1126 after compacting or sorting the table since the entries move around 1127 thus causing the internal minimal_symbol pointers to become jumbled. */ 1128 1129 static void 1130 build_minimal_symbol_hash_tables (struct objfile *objfile) 1131 { 1132 int i; 1133 struct minimal_symbol *msym; 1134 1135 /* Clear the hash tables. */ 1136 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++) 1137 { 1138 objfile->msymbol_hash[i] = 0; 1139 objfile->msymbol_demangled_hash[i] = 0; 1140 } 1141 1142 /* Now, (re)insert the actual entries. */ 1143 for (i = objfile->minimal_symbol_count, msym = objfile->msymbols; 1144 i > 0; 1145 i--, msym++) 1146 { 1147 msym->hash_next = 0; 1148 add_minsym_to_hash_table (msym, objfile->msymbol_hash); 1149 1150 msym->demangled_hash_next = 0; 1151 if (SYMBOL_SEARCH_NAME (msym) != SYMBOL_LINKAGE_NAME (msym)) 1152 add_minsym_to_demangled_hash_table (msym, 1153 objfile->msymbol_demangled_hash); 1154 } 1155 } 1156 1157 /* Add the minimal symbols in the existing bunches to the objfile's official 1158 minimal symbol table. In most cases there is no minimal symbol table yet 1159 for this objfile, and the existing bunches are used to create one. Once 1160 in a while (for shared libraries for example), we add symbols (e.g. common 1161 symbols) to an existing objfile. 1162 1163 Because of the way minimal symbols are collected, we generally have no way 1164 of knowing what source language applies to any particular minimal symbol. 1165 Specifically, we have no way of knowing if the minimal symbol comes from a 1166 C++ compilation unit or not. So for the sake of supporting cached 1167 demangled C++ names, we have no choice but to try and demangle each new one 1168 that comes in. If the demangling succeeds, then we assume it is a C++ 1169 symbol and set the symbol's language and demangled name fields 1170 appropriately. Note that in order to avoid unnecessary demanglings, and 1171 allocating obstack space that subsequently can't be freed for the demangled 1172 names, we mark all newly added symbols with language_auto. After 1173 compaction of the minimal symbols, we go back and scan the entire minimal 1174 symbol table looking for these new symbols. For each new symbol we attempt 1175 to demangle it, and if successful, record it as a language_cplus symbol 1176 and cache the demangled form on the symbol obstack. Symbols which don't 1177 demangle are marked as language_unknown symbols, which inhibits future 1178 attempts to demangle them if we later add more minimal symbols. */ 1179 1180 void 1181 install_minimal_symbols (struct objfile *objfile) 1182 { 1183 int bindex; 1184 int mcount; 1185 struct msym_bunch *bunch; 1186 struct minimal_symbol *msymbols; 1187 int alloc_count; 1188 1189 if (msym_count > 0) 1190 { 1191 /* Allocate enough space in the obstack, into which we will gather the 1192 bunches of new and existing minimal symbols, sort them, and then 1193 compact out the duplicate entries. Once we have a final table, 1194 we will give back the excess space. */ 1195 1196 alloc_count = msym_count + objfile->minimal_symbol_count + 1; 1197 obstack_blank (&objfile->objfile_obstack, 1198 alloc_count * sizeof (struct minimal_symbol)); 1199 msymbols = (struct minimal_symbol *) 1200 obstack_base (&objfile->objfile_obstack); 1201 1202 /* Copy in the existing minimal symbols, if there are any. */ 1203 1204 if (objfile->minimal_symbol_count) 1205 memcpy ((char *) msymbols, (char *) objfile->msymbols, 1206 objfile->minimal_symbol_count * sizeof (struct minimal_symbol)); 1207 1208 /* Walk through the list of minimal symbol bunches, adding each symbol 1209 to the new contiguous array of symbols. Note that we start with the 1210 current, possibly partially filled bunch (thus we use the current 1211 msym_bunch_index for the first bunch we copy over), and thereafter 1212 each bunch is full. */ 1213 1214 mcount = objfile->minimal_symbol_count; 1215 1216 for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next) 1217 { 1218 for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++) 1219 msymbols[mcount] = bunch->contents[bindex]; 1220 msym_bunch_index = BUNCH_SIZE; 1221 } 1222 1223 /* Sort the minimal symbols by address. */ 1224 1225 qsort (msymbols, mcount, sizeof (struct minimal_symbol), 1226 compare_minimal_symbols); 1227 1228 /* Compact out any duplicates, and free up whatever space we are 1229 no longer using. */ 1230 1231 mcount = compact_minimal_symbols (msymbols, mcount, objfile); 1232 1233 obstack_blank (&objfile->objfile_obstack, 1234 (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol)); 1235 msymbols = (struct minimal_symbol *) 1236 obstack_finish (&objfile->objfile_obstack); 1237 1238 /* We also terminate the minimal symbol table with a "null symbol", 1239 which is *not* included in the size of the table. This makes it 1240 easier to find the end of the table when we are handed a pointer 1241 to some symbol in the middle of it. Zero out the fields in the 1242 "null symbol" allocated at the end of the array. Note that the 1243 symbol count does *not* include this null symbol, which is why it 1244 is indexed by mcount and not mcount-1. */ 1245 1246 SYMBOL_LINKAGE_NAME (&msymbols[mcount]) = NULL; 1247 SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0; 1248 MSYMBOL_TARGET_FLAG_1 (&msymbols[mcount]) = 0; 1249 MSYMBOL_TARGET_FLAG_2 (&msymbols[mcount]) = 0; 1250 MSYMBOL_SIZE (&msymbols[mcount]) = 0; 1251 MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown; 1252 SYMBOL_SET_LANGUAGE (&msymbols[mcount], language_unknown); 1253 1254 /* Attach the minimal symbol table to the specified objfile. 1255 The strings themselves are also located in the objfile_obstack 1256 of this objfile. */ 1257 1258 objfile->minimal_symbol_count = mcount; 1259 objfile->msymbols = msymbols; 1260 1261 /* Try to guess the appropriate C++ ABI by looking at the names 1262 of the minimal symbols in the table. */ 1263 { 1264 int i; 1265 1266 for (i = 0; i < mcount; i++) 1267 { 1268 /* If a symbol's name starts with _Z and was successfully 1269 demangled, then we can assume we've found a GNU v3 symbol. 1270 For now we set the C++ ABI globally; if the user is 1271 mixing ABIs then the user will need to "set cp-abi" 1272 manually. */ 1273 const char *name = SYMBOL_LINKAGE_NAME (&objfile->msymbols[i]); 1274 1275 if (name[0] == '_' && name[1] == 'Z' 1276 && SYMBOL_DEMANGLED_NAME (&objfile->msymbols[i]) != NULL) 1277 { 1278 set_cp_abi_as_auto_default ("gnu-v3"); 1279 break; 1280 } 1281 } 1282 } 1283 1284 /* Now build the hash tables; we can't do this incrementally 1285 at an earlier point since we weren't finished with the obstack 1286 yet. (And if the msymbol obstack gets moved, all the internal 1287 pointers to other msymbols need to be adjusted.) */ 1288 build_minimal_symbol_hash_tables (objfile); 1289 } 1290 } 1291 1292 /* Sort all the minimal symbols in OBJFILE. */ 1293 1294 void 1295 msymbols_sort (struct objfile *objfile) 1296 { 1297 qsort (objfile->msymbols, objfile->minimal_symbol_count, 1298 sizeof (struct minimal_symbol), compare_minimal_symbols); 1299 build_minimal_symbol_hash_tables (objfile); 1300 } 1301 1302 /* Check if PC is in a shared library trampoline code stub. 1303 Return minimal symbol for the trampoline entry or NULL if PC is not 1304 in a trampoline code stub. */ 1305 1306 struct minimal_symbol * 1307 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc) 1308 { 1309 struct obj_section *section = find_pc_section (pc); 1310 struct minimal_symbol *msymbol; 1311 1312 if (section == NULL) 1313 return NULL; 1314 msymbol = lookup_minimal_symbol_by_pc_section_1 (pc, section, 1); 1315 1316 if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) 1317 return msymbol; 1318 return NULL; 1319 } 1320 1321 /* If PC is in a shared library trampoline code stub, return the 1322 address of the `real' function belonging to the stub. 1323 Return 0 if PC is not in a trampoline code stub or if the real 1324 function is not found in the minimal symbol table. 1325 1326 We may fail to find the right function if a function with the 1327 same name is defined in more than one shared library, but this 1328 is considered bad programming style. We could return 0 if we find 1329 a duplicate function in case this matters someday. */ 1330 1331 CORE_ADDR 1332 find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc) 1333 { 1334 struct objfile *objfile; 1335 struct minimal_symbol *msymbol; 1336 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc); 1337 1338 if (tsymbol != NULL) 1339 { 1340 ALL_MSYMBOLS (objfile, msymbol) 1341 { 1342 if ((MSYMBOL_TYPE (msymbol) == mst_text 1343 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc) 1344 && strcmp (SYMBOL_LINKAGE_NAME (msymbol), 1345 SYMBOL_LINKAGE_NAME (tsymbol)) == 0) 1346 return SYMBOL_VALUE_ADDRESS (msymbol); 1347 1348 /* Also handle minimal symbols pointing to function descriptors. */ 1349 if (MSYMBOL_TYPE (msymbol) == mst_data 1350 && strcmp (SYMBOL_LINKAGE_NAME (msymbol), 1351 SYMBOL_LINKAGE_NAME (tsymbol)) == 0) 1352 { 1353 CORE_ADDR func; 1354 1355 func = gdbarch_convert_from_func_ptr_addr 1356 (get_objfile_arch (objfile), 1357 SYMBOL_VALUE_ADDRESS (msymbol), 1358 ¤t_target); 1359 1360 /* Ignore data symbols that are not function descriptors. */ 1361 if (func != SYMBOL_VALUE_ADDRESS (msymbol)) 1362 return func; 1363 } 1364 } 1365 } 1366 return 0; 1367 } 1368