0f854422e0f7bdfc7dfb8efe2278428cdc46e72a
[deliverable/binutils-gdb.git] / gdb / minsyms.c
1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright (C) 1992-2018 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 "symtab.h"
42 #include "bfd.h"
43 #include "filenames.h"
44 #include "symfile.h"
45 #include "objfiles.h"
46 #include "demangle.h"
47 #include "value.h"
48 #include "cp-abi.h"
49 #include "target.h"
50 #include "cp-support.h"
51 #include "language.h"
52 #include "cli/cli-utils.h"
53 #include "symbol.h"
54 #include <algorithm>
55 #include "safe-ctype.h"
56
57 /* See minsyms.h. */
58
59 bool
60 msymbol_is_function (struct objfile *objfile, minimal_symbol *minsym,
61 CORE_ADDR *func_address_p)
62 {
63 CORE_ADDR msym_addr = MSYMBOL_VALUE_ADDRESS (objfile, minsym);
64
65 switch (minsym->type)
66 {
67 case mst_slot_got_plt:
68 case mst_data:
69 case mst_bss:
70 case mst_abs:
71 case mst_file_data:
72 case mst_file_bss:
73 case mst_data_gnu_ifunc:
74 {
75 struct gdbarch *gdbarch = get_objfile_arch (objfile);
76 CORE_ADDR pc
77 = gdbarch_convert_from_func_ptr_addr (gdbarch, msym_addr,
78 current_top_target ());
79 if (pc != msym_addr)
80 {
81 if (func_address_p != NULL)
82 *func_address_p = pc;
83 return true;
84 }
85 return false;
86 }
87 default:
88 if (func_address_p != NULL)
89 *func_address_p = msym_addr;
90 return true;
91 }
92 }
93
94 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
95 At the end, copy them all into one newly allocated location on an objfile's
96 per-BFD storage obstack. */
97
98 #define BUNCH_SIZE 127
99
100 struct msym_bunch
101 {
102 struct msym_bunch *next;
103 struct minimal_symbol contents[BUNCH_SIZE];
104 };
105
106 /* See minsyms.h. */
107
108 unsigned int
109 msymbol_hash_iw (const char *string)
110 {
111 unsigned int hash = 0;
112
113 while (*string && *string != '(')
114 {
115 string = skip_spaces (string);
116 if (*string && *string != '(')
117 {
118 hash = SYMBOL_HASH_NEXT (hash, *string);
119 ++string;
120 }
121 }
122 return hash;
123 }
124
125 /* See minsyms.h. */
126
127 unsigned int
128 msymbol_hash (const char *string)
129 {
130 unsigned int hash = 0;
131
132 for (; *string; ++string)
133 hash = SYMBOL_HASH_NEXT (hash, *string);
134 return hash;
135 }
136
137 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
138 static void
139 add_minsym_to_hash_table (struct minimal_symbol *sym,
140 struct minimal_symbol **table)
141 {
142 if (sym->hash_next == NULL)
143 {
144 unsigned int hash
145 = msymbol_hash (MSYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
146
147 sym->hash_next = table[hash];
148 table[hash] = sym;
149 }
150 }
151
152 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
153 TABLE. */
154 static void
155 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
156 struct objfile *objfile)
157 {
158 if (sym->demangled_hash_next == NULL)
159 {
160 unsigned int hash = search_name_hash (MSYMBOL_LANGUAGE (sym),
161 MSYMBOL_SEARCH_NAME (sym));
162
163 auto &vec = objfile->per_bfd->demangled_hash_languages;
164 auto it = std::lower_bound (vec.begin (), vec.end (),
165 MSYMBOL_LANGUAGE (sym));
166 if (it == vec.end () || *it != MSYMBOL_LANGUAGE (sym))
167 vec.insert (it, MSYMBOL_LANGUAGE (sym));
168
169 struct minimal_symbol **table
170 = objfile->per_bfd->msymbol_demangled_hash;
171 unsigned int hash_index = hash % MINIMAL_SYMBOL_HASH_SIZE;
172 sym->demangled_hash_next = table[hash_index];
173 table[hash_index] = sym;
174 }
175 }
176
177 /* Worker object for lookup_minimal_symbol. Stores temporary results
178 while walking the symbol tables. */
179
180 struct found_minimal_symbols
181 {
182 /* External symbols are best. */
183 bound_minimal_symbol external_symbol {};
184
185 /* File-local symbols are next best. */
186 bound_minimal_symbol file_symbol {};
187
188 /* Symbols for shared library trampolines are next best. */
189 bound_minimal_symbol trampoline_symbol {};
190
191 /* Called when a symbol name matches. Check if the minsym is a
192 better type than what we had already found, and record it in one
193 of the members fields if so. Returns true if we collected the
194 real symbol, in which case we can stop searching. */
195 bool maybe_collect (const char *sfile, objfile *objf,
196 minimal_symbol *msymbol);
197 };
198
199 /* See declaration above. */
200
201 bool
202 found_minimal_symbols::maybe_collect (const char *sfile,
203 struct objfile *objfile,
204 minimal_symbol *msymbol)
205 {
206 switch (MSYMBOL_TYPE (msymbol))
207 {
208 case mst_file_text:
209 case mst_file_data:
210 case mst_file_bss:
211 if (sfile == NULL
212 || filename_cmp (msymbol->filename, sfile) == 0)
213 {
214 file_symbol.minsym = msymbol;
215 file_symbol.objfile = objfile;
216 }
217 break;
218
219 case mst_solib_trampoline:
220
221 /* If a trampoline symbol is found, we prefer to keep
222 looking for the *real* symbol. If the actual symbol
223 is not found, then we'll use the trampoline
224 entry. */
225 if (trampoline_symbol.minsym == NULL)
226 {
227 trampoline_symbol.minsym = msymbol;
228 trampoline_symbol.objfile = objfile;
229 }
230 break;
231
232 case mst_unknown:
233 default:
234 external_symbol.minsym = msymbol;
235 external_symbol.objfile = objfile;
236 /* We have the real symbol. No use looking further. */
237 return true;
238 }
239
240 /* Keep looking. */
241 return false;
242 }
243
244 /* Walk the mangled name hash table, and pass each symbol whose name
245 matches LOOKUP_NAME according to NAMECMP to FOUND. */
246
247 static void
248 lookup_minimal_symbol_mangled (const char *lookup_name,
249 const char *sfile,
250 struct objfile *objfile,
251 struct minimal_symbol **table,
252 unsigned int hash,
253 int (*namecmp) (const char *, const char *),
254 found_minimal_symbols &found)
255 {
256 for (minimal_symbol *msymbol = table[hash];
257 msymbol != NULL;
258 msymbol = msymbol->hash_next)
259 {
260 const char *symbol_name = MSYMBOL_LINKAGE_NAME (msymbol);
261
262 if (namecmp (symbol_name, lookup_name) == 0
263 && found.maybe_collect (sfile, objfile, msymbol))
264 return;
265 }
266 }
267
268 /* Walk the demangled name hash table, and pass each symbol whose name
269 matches LOOKUP_NAME according to MATCHER to FOUND. */
270
271 static void
272 lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name,
273 const char *sfile,
274 struct objfile *objfile,
275 struct minimal_symbol **table,
276 unsigned int hash,
277 symbol_name_matcher_ftype *matcher,
278 found_minimal_symbols &found)
279 {
280 for (minimal_symbol *msymbol = table[hash];
281 msymbol != NULL;
282 msymbol = msymbol->demangled_hash_next)
283 {
284 const char *symbol_name = MSYMBOL_SEARCH_NAME (msymbol);
285
286 if (matcher (symbol_name, lookup_name, NULL)
287 && found.maybe_collect (sfile, objfile, msymbol))
288 return;
289 }
290 }
291
292 /* Look through all the current minimal symbol tables and find the
293 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
294 the search to that objfile. If SFILE is non-NULL, the only file-scope
295 symbols considered will be from that source file (global symbols are
296 still preferred). Returns a pointer to the minimal symbol that
297 matches, or NULL if no match is found.
298
299 Note: One instance where there may be duplicate minimal symbols with
300 the same name is when the symbol tables for a shared library and the
301 symbol tables for an executable contain global symbols with the same
302 names (the dynamic linker deals with the duplication).
303
304 It's also possible to have minimal symbols with different mangled
305 names, but identical demangled names. For example, the GNU C++ v3
306 ABI requires the generation of two (or perhaps three) copies of
307 constructor functions --- "in-charge", "not-in-charge", and
308 "allocate" copies; destructors may be duplicated as well.
309 Obviously, there must be distinct mangled names for each of these,
310 but the demangled names are all the same: S::S or S::~S. */
311
312 struct bound_minimal_symbol
313 lookup_minimal_symbol (const char *name, const char *sfile,
314 struct objfile *objf)
315 {
316 struct objfile *objfile;
317 found_minimal_symbols found;
318
319 unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
320
321 auto *mangled_cmp
322 = (case_sensitivity == case_sensitive_on
323 ? strcmp
324 : strcasecmp);
325
326 if (sfile != NULL)
327 sfile = lbasename (sfile);
328
329 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
330
331 for (objfile = object_files;
332 objfile != NULL && found.external_symbol.minsym == NULL;
333 objfile = objfile->next)
334 {
335 if (objf == NULL || objf == objfile
336 || objf == objfile->separate_debug_objfile_backlink)
337 {
338 if (symbol_lookup_debug)
339 {
340 fprintf_unfiltered (gdb_stdlog,
341 "lookup_minimal_symbol (%s, %s, %s)\n",
342 name, sfile != NULL ? sfile : "NULL",
343 objfile_debug_name (objfile));
344 }
345
346 /* Do two passes: the first over the ordinary hash table,
347 and the second over the demangled hash table. */
348 lookup_minimal_symbol_mangled (name, sfile, objfile,
349 objfile->per_bfd->msymbol_hash,
350 mangled_hash, mangled_cmp, found);
351
352 /* If not found, try the demangled hash table. */
353 if (found.external_symbol.minsym == NULL)
354 {
355 /* Once for each language in the demangled hash names
356 table (usually just zero or one languages). */
357 for (auto lang : objfile->per_bfd->demangled_hash_languages)
358 {
359 unsigned int hash
360 = (lookup_name.search_name_hash (lang)
361 % MINIMAL_SYMBOL_HASH_SIZE);
362
363 symbol_name_matcher_ftype *match
364 = get_symbol_name_matcher (language_def (lang),
365 lookup_name);
366 struct minimal_symbol **msymbol_demangled_hash
367 = objfile->per_bfd->msymbol_demangled_hash;
368
369 lookup_minimal_symbol_demangled (lookup_name, sfile, objfile,
370 msymbol_demangled_hash,
371 hash, match, found);
372
373 if (found.external_symbol.minsym != NULL)
374 break;
375 }
376 }
377 }
378 }
379
380 /* External symbols are best. */
381 if (found.external_symbol.minsym != NULL)
382 {
383 if (symbol_lookup_debug)
384 {
385 minimal_symbol *minsym = found.external_symbol.minsym;
386
387 fprintf_unfiltered (gdb_stdlog,
388 "lookup_minimal_symbol (...) = %s (external)\n",
389 host_address_to_string (minsym));
390 }
391 return found.external_symbol;
392 }
393
394 /* File-local symbols are next best. */
395 if (found.file_symbol.minsym != NULL)
396 {
397 if (symbol_lookup_debug)
398 {
399 minimal_symbol *minsym = found.file_symbol.minsym;
400
401 fprintf_unfiltered (gdb_stdlog,
402 "lookup_minimal_symbol (...) = %s (file-local)\n",
403 host_address_to_string (minsym));
404 }
405 return found.file_symbol;
406 }
407
408 /* Symbols for shared library trampolines are next best. */
409 if (found.trampoline_symbol.minsym != NULL)
410 {
411 if (symbol_lookup_debug)
412 {
413 minimal_symbol *minsym = found.trampoline_symbol.minsym;
414
415 fprintf_unfiltered (gdb_stdlog,
416 "lookup_minimal_symbol (...) = %s (trampoline)\n",
417 host_address_to_string (minsym));
418 }
419
420 return found.trampoline_symbol;
421 }
422
423 /* Not found. */
424 if (symbol_lookup_debug)
425 fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
426 return {};
427 }
428
429 /* See minsyms.h. */
430
431 struct bound_minimal_symbol
432 lookup_bound_minimal_symbol (const char *name)
433 {
434 return lookup_minimal_symbol (name, NULL, NULL);
435 }
436
437 /* See common/symbol.h. */
438
439 int
440 find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
441 struct objfile *objfile)
442 {
443 struct bound_minimal_symbol sym
444 = lookup_minimal_symbol (name, NULL, objfile);
445
446 if (sym.minsym != NULL)
447 *addr = BMSYMBOL_VALUE_ADDRESS (sym);
448
449 return sym.minsym == NULL;
450 }
451
452 /* Get the lookup name form best suitable for linkage name
453 matching. */
454
455 static const char *
456 linkage_name_str (const lookup_name_info &lookup_name)
457 {
458 /* Unlike most languages (including C++), Ada uses the
459 encoded/linkage name as the search name recorded in symbols. So
460 if debugging in Ada mode, prefer the Ada-encoded name. This also
461 makes Ada's verbatim match syntax ("<...>") work, because
462 "lookup_name.name()" includes the "<>"s, while
463 "lookup_name.ada().lookup_name()" is the encoded name with "<>"s
464 stripped. */
465 if (current_language->la_language == language_ada)
466 return lookup_name.ada ().lookup_name ().c_str ();
467
468 return lookup_name.name ().c_str ();
469 }
470
471 /* See minsyms.h. */
472
473 void
474 iterate_over_minimal_symbols
475 (struct objfile *objf, const lookup_name_info &lookup_name,
476 gdb::function_view<bool (struct minimal_symbol *)> callback)
477 {
478 /* The first pass is over the ordinary hash table. */
479 {
480 const char *name = linkage_name_str (lookup_name);
481 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
482 auto *mangled_cmp
483 = (case_sensitivity == case_sensitive_on
484 ? strcmp
485 : strcasecmp);
486
487 for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash];
488 iter != NULL;
489 iter = iter->hash_next)
490 {
491 if (mangled_cmp (MSYMBOL_LINKAGE_NAME (iter), name) == 0)
492 if (callback (iter))
493 return;
494 }
495 }
496
497 /* The second pass is over the demangled table. Once for each
498 language in the demangled hash names table (usually just zero or
499 one). */
500 for (auto lang : objf->per_bfd->demangled_hash_languages)
501 {
502 const language_defn *lang_def = language_def (lang);
503 symbol_name_matcher_ftype *name_match
504 = get_symbol_name_matcher (lang_def, lookup_name);
505
506 unsigned int hash
507 = lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE;
508 for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash];
509 iter != NULL;
510 iter = iter->demangled_hash_next)
511 if (name_match (MSYMBOL_SEARCH_NAME (iter), lookup_name, NULL))
512 if (callback (iter))
513 return;
514 }
515 }
516
517 /* See minsyms.h. */
518
519 struct bound_minimal_symbol
520 lookup_minimal_symbol_text (const char *name, struct objfile *objf)
521 {
522 struct objfile *objfile;
523 struct minimal_symbol *msymbol;
524 struct bound_minimal_symbol found_symbol = { NULL, NULL };
525 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
526
527 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
528
529 for (objfile = object_files;
530 objfile != NULL && found_symbol.minsym == NULL;
531 objfile = objfile->next)
532 {
533 if (objf == NULL || objf == objfile
534 || objf == objfile->separate_debug_objfile_backlink)
535 {
536 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
537 msymbol != NULL && found_symbol.minsym == NULL;
538 msymbol = msymbol->hash_next)
539 {
540 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
541 (MSYMBOL_TYPE (msymbol) == mst_text
542 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
543 || MSYMBOL_TYPE (msymbol) == mst_file_text))
544 {
545 switch (MSYMBOL_TYPE (msymbol))
546 {
547 case mst_file_text:
548 found_file_symbol.minsym = msymbol;
549 found_file_symbol.objfile = objfile;
550 break;
551 default:
552 found_symbol.minsym = msymbol;
553 found_symbol.objfile = objfile;
554 break;
555 }
556 }
557 }
558 }
559 }
560 /* External symbols are best. */
561 if (found_symbol.minsym)
562 return found_symbol;
563
564 /* File-local symbols are next best. */
565 return found_file_symbol;
566 }
567
568 /* See minsyms.h. */
569
570 struct minimal_symbol *
571 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name,
572 struct objfile *objf)
573 {
574 struct objfile *objfile;
575 struct minimal_symbol *msymbol;
576
577 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
578
579 for (objfile = object_files;
580 objfile != NULL;
581 objfile = objfile->next)
582 {
583 if (objf == NULL || objf == objfile
584 || objf == objfile->separate_debug_objfile_backlink)
585 {
586 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
587 msymbol != NULL;
588 msymbol = msymbol->hash_next)
589 {
590 if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
591 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0)
592 return msymbol;
593 }
594 }
595 }
596
597 return NULL;
598 }
599
600 /* See minsyms.h. */
601
602 struct bound_minimal_symbol
603 lookup_minimal_symbol_solib_trampoline (const char *name,
604 struct objfile *objf)
605 {
606 struct objfile *objfile;
607 struct minimal_symbol *msymbol;
608 struct bound_minimal_symbol found_symbol = { NULL, NULL };
609
610 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
611
612 for (objfile = object_files;
613 objfile != NULL;
614 objfile = objfile->next)
615 {
616 if (objf == NULL || objf == objfile
617 || objf == objfile->separate_debug_objfile_backlink)
618 {
619 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
620 msymbol != NULL;
621 msymbol = msymbol->hash_next)
622 {
623 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
624 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
625 {
626 found_symbol.objfile = objfile;
627 found_symbol.minsym = msymbol;
628 return found_symbol;
629 }
630 }
631 }
632 }
633
634 return found_symbol;
635 }
636
637 /* A helper function that makes *PC section-relative. This searches
638 the sections of OBJFILE and if *PC is in a section, it subtracts
639 the section offset and returns true. Otherwise it returns
640 false. */
641
642 static int
643 frob_address (struct objfile *objfile, CORE_ADDR *pc)
644 {
645 struct obj_section *iter;
646
647 ALL_OBJFILE_OSECTIONS (objfile, iter)
648 {
649 if (*pc >= obj_section_addr (iter) && *pc < obj_section_endaddr (iter))
650 {
651 *pc -= obj_section_offset (iter);
652 return 1;
653 }
654 }
655
656 return 0;
657 }
658
659 /* Helper for lookup_minimal_symbol_by_pc_section. Convert a
660 lookup_msym_prefer to a minimal_symbol_type. */
661
662 static minimal_symbol_type
663 msym_prefer_to_msym_type (lookup_msym_prefer prefer)
664 {
665 switch (prefer)
666 {
667 case lookup_msym_prefer::TEXT:
668 return mst_text;
669 case lookup_msym_prefer::TRAMPOLINE:
670 return mst_solib_trampoline;
671 case lookup_msym_prefer::GNU_IFUNC:
672 return mst_text_gnu_ifunc;
673 }
674
675 /* Assert here instead of in a default switch case above so that
676 -Wswitch warns if a new enumerator is added. */
677 gdb_assert_not_reached ("unhandled lookup_msym_prefer");
678 }
679
680 /* Search through the minimal symbol table for each objfile and find
681 the symbol whose address is the largest address that is still less
682 than or equal to PC, and matches SECTION (which is not NULL).
683 Returns a pointer to the minimal symbol if such a symbol is found,
684 or NULL if PC is not in a suitable range.
685 Note that we need to look through ALL the minimal symbol tables
686 before deciding on the symbol that comes closest to the specified PC.
687 This is because objfiles can overlap, for example objfile A has .text
688 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
689 .data at 0x40048.
690
691 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
692 there are text and trampoline symbols at the same address.
693 Otherwise prefer mst_text symbols. */
694
695 bound_minimal_symbol
696 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section,
697 lookup_msym_prefer prefer)
698 {
699 int lo;
700 int hi;
701 int newobj;
702 struct objfile *objfile;
703 struct minimal_symbol *msymbol;
704 struct minimal_symbol *best_symbol = NULL;
705 struct objfile *best_objfile = NULL;
706 struct bound_minimal_symbol result;
707
708 if (section == NULL)
709 {
710 section = find_pc_section (pc_in);
711 if (section == NULL)
712 return {};
713 }
714
715 minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer);
716
717 /* We can not require the symbol found to be in section, because
718 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
719 symbol - but find_pc_section won't return an absolute section and
720 hence the code below would skip over absolute symbols. We can
721 still take advantage of the call to find_pc_section, though - the
722 object file still must match. In case we have separate debug
723 files, search both the file and its separate debug file. There's
724 no telling which one will have the minimal symbols. */
725
726 gdb_assert (section != NULL);
727
728 for (objfile = section->objfile;
729 objfile != NULL;
730 objfile = objfile_separate_debug_iterate (section->objfile, objfile))
731 {
732 CORE_ADDR pc = pc_in;
733
734 /* If this objfile has a minimal symbol table, go search it using
735 a binary search. Note that a minimal symbol table always consists
736 of at least two symbols, a "real" symbol and the terminating
737 "null symbol". If there are no real symbols, then there is no
738 minimal symbol table at all. */
739
740 if (objfile->per_bfd->minimal_symbol_count > 0)
741 {
742 int best_zero_sized = -1;
743
744 msymbol = objfile->per_bfd->msymbols;
745 lo = 0;
746 hi = objfile->per_bfd->minimal_symbol_count - 1;
747
748 /* This code assumes that the minimal symbols are sorted by
749 ascending address values. If the pc value is greater than or
750 equal to the first symbol's address, then some symbol in this
751 minimal symbol table is a suitable candidate for being the
752 "best" symbol. This includes the last real symbol, for cases
753 where the pc value is larger than any address in this vector.
754
755 By iterating until the address associated with the current
756 hi index (the endpoint of the test interval) is less than
757 or equal to the desired pc value, we accomplish two things:
758 (1) the case where the pc value is larger than any minimal
759 symbol address is trivially solved, (2) the address associated
760 with the hi index is always the one we want when the interation
761 terminates. In essence, we are iterating the test interval
762 down until the pc value is pushed out of it from the high end.
763
764 Warning: this code is trickier than it would appear at first. */
765
766 if (frob_address (objfile, &pc)
767 && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo]))
768 {
769 while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc)
770 {
771 /* pc is still strictly less than highest address. */
772 /* Note "new" will always be >= lo. */
773 newobj = (lo + hi) / 2;
774 if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc)
775 || (lo == newobj))
776 {
777 hi = newobj;
778 }
779 else
780 {
781 lo = newobj;
782 }
783 }
784
785 /* If we have multiple symbols at the same address, we want
786 hi to point to the last one. That way we can find the
787 right symbol if it has an index greater than hi. */
788 while (hi < objfile->per_bfd->minimal_symbol_count - 1
789 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
790 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1])))
791 hi++;
792
793 /* Skip various undesirable symbols. */
794 while (hi >= 0)
795 {
796 /* Skip any absolute symbols. This is apparently
797 what adb and dbx do, and is needed for the CM-5.
798 There are two known possible problems: (1) on
799 ELF, apparently end, edata, etc. are absolute.
800 Not sure ignoring them here is a big deal, but if
801 we want to use them, the fix would go in
802 elfread.c. (2) I think shared library entry
803 points on the NeXT are absolute. If we want
804 special handling for this it probably should be
805 triggered by a special mst_abs_or_lib or some
806 such. */
807
808 if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs)
809 {
810 hi--;
811 continue;
812 }
813
814 /* If SECTION was specified, skip any symbol from
815 wrong section. */
816 if (section
817 /* Some types of debug info, such as COFF,
818 don't fill the bfd_section member, so don't
819 throw away symbols on those platforms. */
820 && MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]) != NULL
821 && (!matching_obj_sections
822 (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]),
823 section)))
824 {
825 hi--;
826 continue;
827 }
828
829 /* If we are looking for a trampoline and this is a
830 text symbol, or the other way around, check the
831 preceding symbol too. If they are otherwise
832 identical prefer that one. */
833 if (hi > 0
834 && MSYMBOL_TYPE (&msymbol[hi]) != want_type
835 && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type
836 && (MSYMBOL_SIZE (&msymbol[hi])
837 == MSYMBOL_SIZE (&msymbol[hi - 1]))
838 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
839 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]))
840 && (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi])
841 == MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi - 1])))
842 {
843 hi--;
844 continue;
845 }
846
847 /* If the minimal symbol has a zero size, save it
848 but keep scanning backwards looking for one with
849 a non-zero size. A zero size may mean that the
850 symbol isn't an object or function (e.g. a
851 label), or it may just mean that the size was not
852 specified. */
853 if (MSYMBOL_SIZE (&msymbol[hi]) == 0)
854 {
855 if (best_zero_sized == -1)
856 best_zero_sized = hi;
857 hi--;
858 continue;
859 }
860
861 /* If we are past the end of the current symbol, try
862 the previous symbol if it has a larger overlapping
863 size. This happens on i686-pc-linux-gnu with glibc;
864 the nocancel variants of system calls are inside
865 the cancellable variants, but both have sizes. */
866 if (hi > 0
867 && MSYMBOL_SIZE (&msymbol[hi]) != 0
868 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
869 + MSYMBOL_SIZE (&msymbol[hi]))
870 && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])
871 + MSYMBOL_SIZE (&msymbol[hi - 1])))
872 {
873 hi--;
874 continue;
875 }
876
877 /* Otherwise, this symbol must be as good as we're going
878 to get. */
879 break;
880 }
881
882 /* If HI has a zero size, and best_zero_sized is set,
883 then we had two or more zero-sized symbols; prefer
884 the first one we found (which may have a higher
885 address). Also, if we ran off the end, be sure
886 to back up. */
887 if (best_zero_sized != -1
888 && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
889 hi = best_zero_sized;
890
891 /* If the minimal symbol has a non-zero size, and this
892 PC appears to be outside the symbol's contents, then
893 refuse to use this symbol. If we found a zero-sized
894 symbol with an address greater than this symbol's,
895 use that instead. We assume that if symbols have
896 specified sizes, they do not overlap. */
897
898 if (hi >= 0
899 && MSYMBOL_SIZE (&msymbol[hi]) != 0
900 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
901 + MSYMBOL_SIZE (&msymbol[hi])))
902 {
903 if (best_zero_sized != -1)
904 hi = best_zero_sized;
905 else
906 /* Go on to the next object file. */
907 continue;
908 }
909
910 /* The minimal symbol indexed by hi now is the best one in this
911 objfile's minimal symbol table. See if it is the best one
912 overall. */
913
914 if (hi >= 0
915 && ((best_symbol == NULL) ||
916 (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) <
917 MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]))))
918 {
919 best_symbol = &msymbol[hi];
920 best_objfile = objfile;
921 }
922 }
923 }
924 }
925
926 result.minsym = best_symbol;
927 result.objfile = best_objfile;
928 return result;
929 }
930
931 /* See minsyms.h. */
932
933 struct bound_minimal_symbol
934 lookup_minimal_symbol_by_pc (CORE_ADDR pc)
935 {
936 return lookup_minimal_symbol_by_pc_section (pc, NULL);
937 }
938
939 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
940
941 int
942 in_gnu_ifunc_stub (CORE_ADDR pc)
943 {
944 bound_minimal_symbol msymbol
945 = lookup_minimal_symbol_by_pc_section (pc, NULL,
946 lookup_msym_prefer::GNU_IFUNC);
947 return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc;
948 }
949
950 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */
951
952 static CORE_ADDR
953 stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
954 {
955 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
956 "the ELF support compiled in."),
957 paddress (gdbarch, pc));
958 }
959
960 /* See elf_gnu_ifunc_resolve_name for its real implementation. */
961
962 static int
963 stub_gnu_ifunc_resolve_name (const char *function_name,
964 CORE_ADDR *function_address_p)
965 {
966 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
967 "the ELF support compiled in."),
968 function_name);
969 }
970
971 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */
972
973 static void
974 stub_gnu_ifunc_resolver_stop (struct breakpoint *b)
975 {
976 internal_error (__FILE__, __LINE__,
977 _("elf_gnu_ifunc_resolver_stop cannot be reached."));
978 }
979
980 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
981
982 static void
983 stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
984 {
985 internal_error (__FILE__, __LINE__,
986 _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
987 }
988
989 /* See elf_gnu_ifunc_fns for its real implementation. */
990
991 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns =
992 {
993 stub_gnu_ifunc_resolve_addr,
994 stub_gnu_ifunc_resolve_name,
995 stub_gnu_ifunc_resolver_stop,
996 stub_gnu_ifunc_resolver_return_stop,
997 };
998
999 /* A placeholder for &elf_gnu_ifunc_fns. */
1000
1001 const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns;
1002
1003 \f
1004
1005 /* Return leading symbol character for a BFD. If BFD is NULL,
1006 return the leading symbol character from the main objfile. */
1007
1008 static int
1009 get_symbol_leading_char (bfd *abfd)
1010 {
1011 if (abfd != NULL)
1012 return bfd_get_symbol_leading_char (abfd);
1013 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
1014 return bfd_get_symbol_leading_char (symfile_objfile->obfd);
1015 return 0;
1016 }
1017
1018 /* See minsyms.h. */
1019
1020 minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj)
1021 : m_objfile (obj),
1022 m_msym_bunch (NULL),
1023 /* Note that presetting m_msym_bunch_index to BUNCH_SIZE causes the
1024 first call to save a minimal symbol to allocate the memory for
1025 the first bunch. */
1026 m_msym_bunch_index (BUNCH_SIZE),
1027 m_msym_count (0)
1028 {
1029 }
1030
1031 /* Discard the currently collected minimal symbols, if any. If we wish
1032 to save them for later use, we must have already copied them somewhere
1033 else before calling this function.
1034
1035 FIXME: We could allocate the minimal symbol bunches on their own
1036 obstack and then simply blow the obstack away when we are done with
1037 it. Is it worth the extra trouble though? */
1038
1039 minimal_symbol_reader::~minimal_symbol_reader ()
1040 {
1041 struct msym_bunch *next;
1042
1043 while (m_msym_bunch != NULL)
1044 {
1045 next = m_msym_bunch->next;
1046 xfree (m_msym_bunch);
1047 m_msym_bunch = next;
1048 }
1049 }
1050
1051 /* See minsyms.h. */
1052
1053 void
1054 minimal_symbol_reader::record (const char *name, CORE_ADDR address,
1055 enum minimal_symbol_type ms_type)
1056 {
1057 int section;
1058
1059 switch (ms_type)
1060 {
1061 case mst_text:
1062 case mst_text_gnu_ifunc:
1063 case mst_file_text:
1064 case mst_solib_trampoline:
1065 section = SECT_OFF_TEXT (m_objfile);
1066 break;
1067 case mst_data:
1068 case mst_data_gnu_ifunc:
1069 case mst_file_data:
1070 section = SECT_OFF_DATA (m_objfile);
1071 break;
1072 case mst_bss:
1073 case mst_file_bss:
1074 section = SECT_OFF_BSS (m_objfile);
1075 break;
1076 default:
1077 section = -1;
1078 }
1079
1080 record_with_info (name, address, ms_type, section);
1081 }
1082
1083 /* See minsyms.h. */
1084
1085 struct minimal_symbol *
1086 minimal_symbol_reader::record_full (const char *name, int name_len,
1087 bool copy_name, CORE_ADDR address,
1088 enum minimal_symbol_type ms_type,
1089 int section)
1090 {
1091 struct msym_bunch *newobj;
1092 struct minimal_symbol *msymbol;
1093
1094 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
1095 the minimal symbols, because if there is also another symbol
1096 at the same address (e.g. the first function of the file),
1097 lookup_minimal_symbol_by_pc would have no way of getting the
1098 right one. */
1099 if (ms_type == mst_file_text && name[0] == 'g'
1100 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
1101 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
1102 return (NULL);
1103
1104 /* It's safe to strip the leading char here once, since the name
1105 is also stored stripped in the minimal symbol table. */
1106 if (name[0] == get_symbol_leading_char (m_objfile->obfd))
1107 {
1108 ++name;
1109 --name_len;
1110 }
1111
1112 if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
1113 return (NULL);
1114
1115 if (m_msym_bunch_index == BUNCH_SIZE)
1116 {
1117 newobj = XCNEW (struct msym_bunch);
1118 m_msym_bunch_index = 0;
1119 newobj->next = m_msym_bunch;
1120 m_msym_bunch = newobj;
1121 }
1122 msymbol = &m_msym_bunch->contents[m_msym_bunch_index];
1123 MSYMBOL_SET_LANGUAGE (msymbol, language_auto,
1124 &m_objfile->per_bfd->storage_obstack);
1125 MSYMBOL_SET_NAMES (msymbol, name, name_len, copy_name, m_objfile);
1126
1127 SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
1128 MSYMBOL_SECTION (msymbol) = section;
1129
1130 MSYMBOL_TYPE (msymbol) = ms_type;
1131 MSYMBOL_TARGET_FLAG_1 (msymbol) = 0;
1132 MSYMBOL_TARGET_FLAG_2 (msymbol) = 0;
1133 /* Do not use the SET_MSYMBOL_SIZE macro to initialize the size,
1134 as it would also set the has_size flag. */
1135 msymbol->size = 0;
1136
1137 /* The hash pointers must be cleared! If they're not,
1138 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
1139 msymbol->hash_next = NULL;
1140 msymbol->demangled_hash_next = NULL;
1141
1142 /* If we already read minimal symbols for this objfile, then don't
1143 ever allocate a new one. */
1144 if (!m_objfile->per_bfd->minsyms_read)
1145 {
1146 m_msym_bunch_index++;
1147 m_objfile->per_bfd->n_minsyms++;
1148 }
1149 m_msym_count++;
1150 return msymbol;
1151 }
1152
1153 /* Compare two minimal symbols by address and return a signed result based
1154 on unsigned comparisons, so that we sort into unsigned numeric order.
1155 Within groups with the same address, sort by name. */
1156
1157 static int
1158 compare_minimal_symbols (const void *fn1p, const void *fn2p)
1159 {
1160 const struct minimal_symbol *fn1;
1161 const struct minimal_symbol *fn2;
1162
1163 fn1 = (const struct minimal_symbol *) fn1p;
1164 fn2 = (const struct minimal_symbol *) fn2p;
1165
1166 if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) < MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1167 {
1168 return (-1); /* addr 1 is less than addr 2. */
1169 }
1170 else if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) > MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1171 {
1172 return (1); /* addr 1 is greater than addr 2. */
1173 }
1174 else
1175 /* addrs are equal: sort by name */
1176 {
1177 const char *name1 = MSYMBOL_LINKAGE_NAME (fn1);
1178 const char *name2 = MSYMBOL_LINKAGE_NAME (fn2);
1179
1180 if (name1 && name2) /* both have names */
1181 return strcmp (name1, name2);
1182 else if (name2)
1183 return 1; /* fn1 has no name, so it is "less". */
1184 else if (name1) /* fn2 has no name, so it is "less". */
1185 return -1;
1186 else
1187 return (0); /* Neither has a name, so they're equal. */
1188 }
1189 }
1190
1191 /* Compact duplicate entries out of a minimal symbol table by walking
1192 through the table and compacting out entries with duplicate addresses
1193 and matching names. Return the number of entries remaining.
1194
1195 On entry, the table resides between msymbol[0] and msymbol[mcount].
1196 On exit, it resides between msymbol[0] and msymbol[result_count].
1197
1198 When files contain multiple sources of symbol information, it is
1199 possible for the minimal symbol table to contain many duplicate entries.
1200 As an example, SVR4 systems use ELF formatted object files, which
1201 usually contain at least two different types of symbol tables (a
1202 standard ELF one and a smaller dynamic linking table), as well as
1203 DWARF debugging information for files compiled with -g.
1204
1205 Without compacting, the minimal symbol table for gdb itself contains
1206 over a 1000 duplicates, about a third of the total table size. Aside
1207 from the potential trap of not noticing that two successive entries
1208 identify the same location, this duplication impacts the time required
1209 to linearly scan the table, which is done in a number of places. So we
1210 just do one linear scan here and toss out the duplicates.
1211
1212 Note that we are not concerned here about recovering the space that
1213 is potentially freed up, because the strings themselves are allocated
1214 on the storage_obstack, and will get automatically freed when the symbol
1215 table is freed. The caller can free up the unused minimal symbols at
1216 the end of the compacted region if their allocation strategy allows it.
1217
1218 Also note we only go up to the next to last entry within the loop
1219 and then copy the last entry explicitly after the loop terminates.
1220
1221 Since the different sources of information for each symbol may
1222 have different levels of "completeness", we may have duplicates
1223 that have one entry with type "mst_unknown" and the other with a
1224 known type. So if the one we are leaving alone has type mst_unknown,
1225 overwrite its type with the type from the one we are compacting out. */
1226
1227 static int
1228 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
1229 struct objfile *objfile)
1230 {
1231 struct minimal_symbol *copyfrom;
1232 struct minimal_symbol *copyto;
1233
1234 if (mcount > 0)
1235 {
1236 copyfrom = copyto = msymbol;
1237 while (copyfrom < msymbol + mcount - 1)
1238 {
1239 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
1240 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
1241 && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
1242 && strcmp (MSYMBOL_LINKAGE_NAME (copyfrom),
1243 MSYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0)
1244 {
1245 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
1246 {
1247 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
1248 }
1249 copyfrom++;
1250 }
1251 else
1252 *copyto++ = *copyfrom++;
1253 }
1254 *copyto++ = *copyfrom++;
1255 mcount = copyto - msymbol;
1256 }
1257 return (mcount);
1258 }
1259
1260 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1261 after compacting or sorting the table since the entries move around
1262 thus causing the internal minimal_symbol pointers to become jumbled. */
1263
1264 static void
1265 build_minimal_symbol_hash_tables (struct objfile *objfile)
1266 {
1267 int i;
1268 struct minimal_symbol *msym;
1269
1270 /* Clear the hash tables. */
1271 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
1272 {
1273 objfile->per_bfd->msymbol_hash[i] = 0;
1274 objfile->per_bfd->msymbol_demangled_hash[i] = 0;
1275 }
1276
1277 /* Now, (re)insert the actual entries. */
1278 for ((i = objfile->per_bfd->minimal_symbol_count,
1279 msym = objfile->per_bfd->msymbols);
1280 i > 0;
1281 i--, msym++)
1282 {
1283 msym->hash_next = 0;
1284 add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash);
1285
1286 msym->demangled_hash_next = 0;
1287 if (MSYMBOL_SEARCH_NAME (msym) != MSYMBOL_LINKAGE_NAME (msym))
1288 add_minsym_to_demangled_hash_table (msym, objfile);
1289 }
1290 }
1291
1292 /* Add the minimal symbols in the existing bunches to the objfile's official
1293 minimal symbol table. In most cases there is no minimal symbol table yet
1294 for this objfile, and the existing bunches are used to create one. Once
1295 in a while (for shared libraries for example), we add symbols (e.g. common
1296 symbols) to an existing objfile.
1297
1298 Because of the way minimal symbols are collected, we generally have no way
1299 of knowing what source language applies to any particular minimal symbol.
1300 Specifically, we have no way of knowing if the minimal symbol comes from a
1301 C++ compilation unit or not. So for the sake of supporting cached
1302 demangled C++ names, we have no choice but to try and demangle each new one
1303 that comes in. If the demangling succeeds, then we assume it is a C++
1304 symbol and set the symbol's language and demangled name fields
1305 appropriately. Note that in order to avoid unnecessary demanglings, and
1306 allocating obstack space that subsequently can't be freed for the demangled
1307 names, we mark all newly added symbols with language_auto. After
1308 compaction of the minimal symbols, we go back and scan the entire minimal
1309 symbol table looking for these new symbols. For each new symbol we attempt
1310 to demangle it, and if successful, record it as a language_cplus symbol
1311 and cache the demangled form on the symbol obstack. Symbols which don't
1312 demangle are marked as language_unknown symbols, which inhibits future
1313 attempts to demangle them if we later add more minimal symbols. */
1314
1315 void
1316 minimal_symbol_reader::install ()
1317 {
1318 int bindex;
1319 int mcount;
1320 struct msym_bunch *bunch;
1321 struct minimal_symbol *msymbols;
1322 int alloc_count;
1323
1324 if (m_objfile->per_bfd->minsyms_read)
1325 return;
1326
1327 if (m_msym_count > 0)
1328 {
1329 if (symtab_create_debug)
1330 {
1331 fprintf_unfiltered (gdb_stdlog,
1332 "Installing %d minimal symbols of objfile %s.\n",
1333 m_msym_count, objfile_name (m_objfile));
1334 }
1335
1336 /* Allocate enough space in the obstack, into which we will gather the
1337 bunches of new and existing minimal symbols, sort them, and then
1338 compact out the duplicate entries. Once we have a final table,
1339 we will give back the excess space. */
1340
1341 alloc_count = m_msym_count + m_objfile->per_bfd->minimal_symbol_count + 1;
1342 obstack_blank (&m_objfile->per_bfd->storage_obstack,
1343 alloc_count * sizeof (struct minimal_symbol));
1344 msymbols = (struct minimal_symbol *)
1345 obstack_base (&m_objfile->per_bfd->storage_obstack);
1346
1347 /* Copy in the existing minimal symbols, if there are any. */
1348
1349 if (m_objfile->per_bfd->minimal_symbol_count)
1350 memcpy ((char *) msymbols, (char *) m_objfile->per_bfd->msymbols,
1351 m_objfile->per_bfd->minimal_symbol_count * sizeof (struct minimal_symbol));
1352
1353 /* Walk through the list of minimal symbol bunches, adding each symbol
1354 to the new contiguous array of symbols. Note that we start with the
1355 current, possibly partially filled bunch (thus we use the current
1356 msym_bunch_index for the first bunch we copy over), and thereafter
1357 each bunch is full. */
1358
1359 mcount = m_objfile->per_bfd->minimal_symbol_count;
1360
1361 for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next)
1362 {
1363 for (bindex = 0; bindex < m_msym_bunch_index; bindex++, mcount++)
1364 msymbols[mcount] = bunch->contents[bindex];
1365 m_msym_bunch_index = BUNCH_SIZE;
1366 }
1367
1368 /* Sort the minimal symbols by address. */
1369
1370 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
1371 compare_minimal_symbols);
1372
1373 /* Compact out any duplicates, and free up whatever space we are
1374 no longer using. */
1375
1376 mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
1377
1378 ssize_t shrink_bytes
1379 = (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol);
1380 obstack_blank_fast (&m_objfile->per_bfd->storage_obstack, shrink_bytes);
1381 msymbols = (struct minimal_symbol *)
1382 obstack_finish (&m_objfile->per_bfd->storage_obstack);
1383
1384 /* We also terminate the minimal symbol table with a "null symbol",
1385 which is *not* included in the size of the table. This makes it
1386 easier to find the end of the table when we are handed a pointer
1387 to some symbol in the middle of it. Zero out the fields in the
1388 "null symbol" allocated at the end of the array. Note that the
1389 symbol count does *not* include this null symbol, which is why it
1390 is indexed by mcount and not mcount-1. */
1391
1392 memset (&msymbols[mcount], 0, sizeof (struct minimal_symbol));
1393
1394 /* Attach the minimal symbol table to the specified objfile.
1395 The strings themselves are also located in the storage_obstack
1396 of this objfile. */
1397
1398 m_objfile->per_bfd->minimal_symbol_count = mcount;
1399 m_objfile->per_bfd->msymbols = msymbols;
1400
1401 /* Now build the hash tables; we can't do this incrementally
1402 at an earlier point since we weren't finished with the obstack
1403 yet. (And if the msymbol obstack gets moved, all the internal
1404 pointers to other msymbols need to be adjusted.) */
1405 build_minimal_symbol_hash_tables (m_objfile);
1406 }
1407 }
1408
1409 /* See minsyms.h. */
1410
1411 void
1412 terminate_minimal_symbol_table (struct objfile *objfile)
1413 {
1414 if (! objfile->per_bfd->msymbols)
1415 objfile->per_bfd->msymbols = XOBNEW (&objfile->per_bfd->storage_obstack,
1416 minimal_symbol);
1417
1418 {
1419 struct minimal_symbol *m
1420 = &objfile->per_bfd->msymbols[objfile->per_bfd->minimal_symbol_count];
1421
1422 memset (m, 0, sizeof (*m));
1423 /* Don't rely on these enumeration values being 0's. */
1424 MSYMBOL_TYPE (m) = mst_unknown;
1425 MSYMBOL_SET_LANGUAGE (m, language_unknown,
1426 &objfile->per_bfd->storage_obstack);
1427 }
1428 }
1429
1430 /* Check if PC is in a shared library trampoline code stub.
1431 Return minimal symbol for the trampoline entry or NULL if PC is not
1432 in a trampoline code stub. */
1433
1434 static struct minimal_symbol *
1435 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
1436 {
1437 bound_minimal_symbol msymbol
1438 = lookup_minimal_symbol_by_pc_section (pc, NULL,
1439 lookup_msym_prefer::TRAMPOLINE);
1440
1441 if (msymbol.minsym != NULL
1442 && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
1443 return msymbol.minsym;
1444 return NULL;
1445 }
1446
1447 /* If PC is in a shared library trampoline code stub, return the
1448 address of the `real' function belonging to the stub.
1449 Return 0 if PC is not in a trampoline code stub or if the real
1450 function is not found in the minimal symbol table.
1451
1452 We may fail to find the right function if a function with the
1453 same name is defined in more than one shared library, but this
1454 is considered bad programming style. We could return 0 if we find
1455 a duplicate function in case this matters someday. */
1456
1457 CORE_ADDR
1458 find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
1459 {
1460 struct objfile *objfile;
1461 struct minimal_symbol *msymbol;
1462 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1463
1464 if (tsymbol != NULL)
1465 {
1466 ALL_MSYMBOLS (objfile, msymbol)
1467 {
1468 /* Also handle minimal symbols pointing to function descriptors. */
1469 if ((MSYMBOL_TYPE (msymbol) == mst_text
1470 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
1471 || MSYMBOL_TYPE (msymbol) == mst_data
1472 || MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc)
1473 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol),
1474 MSYMBOL_LINKAGE_NAME (tsymbol)) == 0)
1475 {
1476 CORE_ADDR func;
1477
1478 /* Ignore data symbols that are not function
1479 descriptors. */
1480 if (msymbol_is_function (objfile, msymbol, &func))
1481 return func;
1482 }
1483 }
1484 }
1485 return 0;
1486 }
1487
1488 /* See minsyms.h. */
1489
1490 CORE_ADDR
1491 minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
1492 {
1493 int i;
1494 short section;
1495 struct obj_section *obj_section;
1496 CORE_ADDR result;
1497 struct minimal_symbol *msymbol;
1498
1499 gdb_assert (minsym.minsym != NULL);
1500
1501 /* If the minimal symbol has a size, use it. Otherwise use the
1502 lesser of the next minimal symbol in the same section, or the end
1503 of the section, as the end of the function. */
1504
1505 if (MSYMBOL_SIZE (minsym.minsym) != 0)
1506 return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
1507
1508 /* Step over other symbols at this same address, and symbols in
1509 other sections, to find the next symbol in this section with a
1510 different address. */
1511
1512 msymbol = minsym.minsym;
1513 section = MSYMBOL_SECTION (msymbol);
1514 for (i = 1; MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++)
1515 {
1516 if ((MSYMBOL_VALUE_RAW_ADDRESS (msymbol + i)
1517 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
1518 && MSYMBOL_SECTION (msymbol + i) == section)
1519 break;
1520 }
1521
1522 obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
1523 if (MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL
1524 && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i)
1525 < obj_section_endaddr (obj_section)))
1526 result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i);
1527 else
1528 /* We got the start address from the last msymbol in the objfile.
1529 So the end address is the end of the section. */
1530 result = obj_section_endaddr (obj_section);
1531
1532 return result;
1533 }
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