Clean up some comments in minsyms.c
[deliverable/binutils-gdb.git] / gdb / minsyms.c
1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright (C) 1992-2019 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 "common/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 array. */
96
97 #define BUNCH_SIZE 127
98
99 struct msym_bunch
100 {
101 struct msym_bunch *next;
102 struct minimal_symbol contents[BUNCH_SIZE];
103 };
104
105 /* See minsyms.h. */
106
107 unsigned int
108 msymbol_hash_iw (const char *string)
109 {
110 unsigned int hash = 0;
111
112 while (*string && *string != '(')
113 {
114 string = skip_spaces (string);
115 if (*string && *string != '(')
116 {
117 hash = SYMBOL_HASH_NEXT (hash, *string);
118 ++string;
119 }
120 }
121 return hash;
122 }
123
124 /* See minsyms.h. */
125
126 unsigned int
127 msymbol_hash (const char *string)
128 {
129 unsigned int hash = 0;
130
131 for (; *string; ++string)
132 hash = SYMBOL_HASH_NEXT (hash, *string);
133 return hash;
134 }
135
136 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
137 static void
138 add_minsym_to_hash_table (struct minimal_symbol *sym,
139 struct minimal_symbol **table)
140 {
141 if (sym->hash_next == NULL)
142 {
143 unsigned int hash
144 = msymbol_hash (MSYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
145
146 sym->hash_next = table[hash];
147 table[hash] = sym;
148 }
149 }
150
151 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
152 TABLE. */
153 static void
154 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
155 struct objfile *objfile)
156 {
157 if (sym->demangled_hash_next == NULL)
158 {
159 unsigned int hash = search_name_hash (MSYMBOL_LANGUAGE (sym),
160 MSYMBOL_SEARCH_NAME (sym));
161
162 objfile->per_bfd->demangled_hash_languages.set (MSYMBOL_LANGUAGE (sym));
163
164 struct minimal_symbol **table
165 = objfile->per_bfd->msymbol_demangled_hash;
166 unsigned int hash_index = hash % MINIMAL_SYMBOL_HASH_SIZE;
167 sym->demangled_hash_next = table[hash_index];
168 table[hash_index] = sym;
169 }
170 }
171
172 /* Worker object for lookup_minimal_symbol. Stores temporary results
173 while walking the symbol tables. */
174
175 struct found_minimal_symbols
176 {
177 /* External symbols are best. */
178 bound_minimal_symbol external_symbol {};
179
180 /* File-local symbols are next best. */
181 bound_minimal_symbol file_symbol {};
182
183 /* Symbols for shared library trampolines are next best. */
184 bound_minimal_symbol trampoline_symbol {};
185
186 /* Called when a symbol name matches. Check if the minsym is a
187 better type than what we had already found, and record it in one
188 of the members fields if so. Returns true if we collected the
189 real symbol, in which case we can stop searching. */
190 bool maybe_collect (const char *sfile, objfile *objf,
191 minimal_symbol *msymbol);
192 };
193
194 /* See declaration above. */
195
196 bool
197 found_minimal_symbols::maybe_collect (const char *sfile,
198 struct objfile *objfile,
199 minimal_symbol *msymbol)
200 {
201 switch (MSYMBOL_TYPE (msymbol))
202 {
203 case mst_file_text:
204 case mst_file_data:
205 case mst_file_bss:
206 if (sfile == NULL
207 || filename_cmp (msymbol->filename, sfile) == 0)
208 {
209 file_symbol.minsym = msymbol;
210 file_symbol.objfile = objfile;
211 }
212 break;
213
214 case mst_solib_trampoline:
215
216 /* If a trampoline symbol is found, we prefer to keep
217 looking for the *real* symbol. If the actual symbol
218 is not found, then we'll use the trampoline
219 entry. */
220 if (trampoline_symbol.minsym == NULL)
221 {
222 trampoline_symbol.minsym = msymbol;
223 trampoline_symbol.objfile = objfile;
224 }
225 break;
226
227 case mst_unknown:
228 default:
229 external_symbol.minsym = msymbol;
230 external_symbol.objfile = objfile;
231 /* We have the real symbol. No use looking further. */
232 return true;
233 }
234
235 /* Keep looking. */
236 return false;
237 }
238
239 /* Walk the mangled name hash table, and pass each symbol whose name
240 matches LOOKUP_NAME according to NAMECMP to FOUND. */
241
242 static void
243 lookup_minimal_symbol_mangled (const char *lookup_name,
244 const char *sfile,
245 struct objfile *objfile,
246 struct minimal_symbol **table,
247 unsigned int hash,
248 int (*namecmp) (const char *, const char *),
249 found_minimal_symbols &found)
250 {
251 for (minimal_symbol *msymbol = table[hash];
252 msymbol != NULL;
253 msymbol = msymbol->hash_next)
254 {
255 const char *symbol_name = MSYMBOL_LINKAGE_NAME (msymbol);
256
257 if (namecmp (symbol_name, lookup_name) == 0
258 && found.maybe_collect (sfile, objfile, msymbol))
259 return;
260 }
261 }
262
263 /* Walk the demangled name hash table, and pass each symbol whose name
264 matches LOOKUP_NAME according to MATCHER to FOUND. */
265
266 static void
267 lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name,
268 const char *sfile,
269 struct objfile *objfile,
270 struct minimal_symbol **table,
271 unsigned int hash,
272 symbol_name_matcher_ftype *matcher,
273 found_minimal_symbols &found)
274 {
275 for (minimal_symbol *msymbol = table[hash];
276 msymbol != NULL;
277 msymbol = msymbol->demangled_hash_next)
278 {
279 const char *symbol_name = MSYMBOL_SEARCH_NAME (msymbol);
280
281 if (matcher (symbol_name, lookup_name, NULL)
282 && found.maybe_collect (sfile, objfile, msymbol))
283 return;
284 }
285 }
286
287 /* Look through all the current minimal symbol tables and find the
288 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
289 the search to that objfile. If SFILE is non-NULL, the only file-scope
290 symbols considered will be from that source file (global symbols are
291 still preferred). Returns a pointer to the minimal symbol that
292 matches, or NULL if no match is found.
293
294 Note: One instance where there may be duplicate minimal symbols with
295 the same name is when the symbol tables for a shared library and the
296 symbol tables for an executable contain global symbols with the same
297 names (the dynamic linker deals with the duplication).
298
299 It's also possible to have minimal symbols with different mangled
300 names, but identical demangled names. For example, the GNU C++ v3
301 ABI requires the generation of two (or perhaps three) copies of
302 constructor functions --- "in-charge", "not-in-charge", and
303 "allocate" copies; destructors may be duplicated as well.
304 Obviously, there must be distinct mangled names for each of these,
305 but the demangled names are all the same: S::S or S::~S. */
306
307 struct bound_minimal_symbol
308 lookup_minimal_symbol (const char *name, const char *sfile,
309 struct objfile *objf)
310 {
311 struct objfile *objfile;
312 found_minimal_symbols found;
313
314 unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
315
316 auto *mangled_cmp
317 = (case_sensitivity == case_sensitive_on
318 ? strcmp
319 : strcasecmp);
320
321 if (sfile != NULL)
322 sfile = lbasename (sfile);
323
324 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
325
326 for (objfile = object_files;
327 objfile != NULL && found.external_symbol.minsym == NULL;
328 objfile = objfile->next)
329 {
330 if (objf == NULL || objf == objfile
331 || objf == objfile->separate_debug_objfile_backlink)
332 {
333 if (symbol_lookup_debug)
334 {
335 fprintf_unfiltered (gdb_stdlog,
336 "lookup_minimal_symbol (%s, %s, %s)\n",
337 name, sfile != NULL ? sfile : "NULL",
338 objfile_debug_name (objfile));
339 }
340
341 /* Do two passes: the first over the ordinary hash table,
342 and the second over the demangled hash table. */
343 lookup_minimal_symbol_mangled (name, sfile, objfile,
344 objfile->per_bfd->msymbol_hash,
345 mangled_hash, mangled_cmp, found);
346
347 /* If not found, try the demangled hash table. */
348 if (found.external_symbol.minsym == NULL)
349 {
350 /* Once for each language in the demangled hash names
351 table (usually just zero or one languages). */
352 for (unsigned iter = 0; iter < nr_languages; ++iter)
353 {
354 if (!objfile->per_bfd->demangled_hash_languages.test (iter))
355 continue;
356 enum language lang = (enum language) iter;
357
358 unsigned int hash
359 = (lookup_name.search_name_hash (lang)
360 % MINIMAL_SYMBOL_HASH_SIZE);
361
362 symbol_name_matcher_ftype *match
363 = get_symbol_name_matcher (language_def (lang),
364 lookup_name);
365 struct minimal_symbol **msymbol_demangled_hash
366 = objfile->per_bfd->msymbol_demangled_hash;
367
368 lookup_minimal_symbol_demangled (lookup_name, sfile, objfile,
369 msymbol_demangled_hash,
370 hash, match, found);
371
372 if (found.external_symbol.minsym != NULL)
373 break;
374 }
375 }
376 }
377 }
378
379 /* External symbols are best. */
380 if (found.external_symbol.minsym != NULL)
381 {
382 if (symbol_lookup_debug)
383 {
384 minimal_symbol *minsym = found.external_symbol.minsym;
385
386 fprintf_unfiltered (gdb_stdlog,
387 "lookup_minimal_symbol (...) = %s (external)\n",
388 host_address_to_string (minsym));
389 }
390 return found.external_symbol;
391 }
392
393 /* File-local symbols are next best. */
394 if (found.file_symbol.minsym != NULL)
395 {
396 if (symbol_lookup_debug)
397 {
398 minimal_symbol *minsym = found.file_symbol.minsym;
399
400 fprintf_unfiltered (gdb_stdlog,
401 "lookup_minimal_symbol (...) = %s (file-local)\n",
402 host_address_to_string (minsym));
403 }
404 return found.file_symbol;
405 }
406
407 /* Symbols for shared library trampolines are next best. */
408 if (found.trampoline_symbol.minsym != NULL)
409 {
410 if (symbol_lookup_debug)
411 {
412 minimal_symbol *minsym = found.trampoline_symbol.minsym;
413
414 fprintf_unfiltered (gdb_stdlog,
415 "lookup_minimal_symbol (...) = %s (trampoline)\n",
416 host_address_to_string (minsym));
417 }
418
419 return found.trampoline_symbol;
420 }
421
422 /* Not found. */
423 if (symbol_lookup_debug)
424 fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
425 return {};
426 }
427
428 /* See minsyms.h. */
429
430 struct bound_minimal_symbol
431 lookup_bound_minimal_symbol (const char *name)
432 {
433 return lookup_minimal_symbol (name, NULL, NULL);
434 }
435
436 /* See common/symbol.h. */
437
438 int
439 find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
440 struct objfile *objfile)
441 {
442 struct bound_minimal_symbol sym
443 = lookup_minimal_symbol (name, NULL, objfile);
444
445 if (sym.minsym != NULL)
446 *addr = BMSYMBOL_VALUE_ADDRESS (sym);
447
448 return sym.minsym == NULL;
449 }
450
451 /* Get the lookup name form best suitable for linkage name
452 matching. */
453
454 static const char *
455 linkage_name_str (const lookup_name_info &lookup_name)
456 {
457 /* Unlike most languages (including C++), Ada uses the
458 encoded/linkage name as the search name recorded in symbols. So
459 if debugging in Ada mode, prefer the Ada-encoded name. This also
460 makes Ada's verbatim match syntax ("<...>") work, because
461 "lookup_name.name()" includes the "<>"s, while
462 "lookup_name.ada().lookup_name()" is the encoded name with "<>"s
463 stripped. */
464 if (current_language->la_language == language_ada)
465 return lookup_name.ada ().lookup_name ().c_str ();
466
467 return lookup_name.name ().c_str ();
468 }
469
470 /* See minsyms.h. */
471
472 void
473 iterate_over_minimal_symbols
474 (struct objfile *objf, const lookup_name_info &lookup_name,
475 gdb::function_view<bool (struct minimal_symbol *)> callback)
476 {
477 /* The first pass is over the ordinary hash table. */
478 {
479 const char *name = linkage_name_str (lookup_name);
480 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
481 auto *mangled_cmp
482 = (case_sensitivity == case_sensitive_on
483 ? strcmp
484 : strcasecmp);
485
486 for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash];
487 iter != NULL;
488 iter = iter->hash_next)
489 {
490 if (mangled_cmp (MSYMBOL_LINKAGE_NAME (iter), name) == 0)
491 if (callback (iter))
492 return;
493 }
494 }
495
496 /* The second pass is over the demangled table. Once for each
497 language in the demangled hash names table (usually just zero or
498 one). */
499 for (unsigned liter = 0; liter < nr_languages; ++liter)
500 {
501 if (!objf->per_bfd->demangled_hash_languages.test (liter))
502 continue;
503
504 enum language lang = (enum language) liter;
505 const language_defn *lang_def = language_def (lang);
506 symbol_name_matcher_ftype *name_match
507 = get_symbol_name_matcher (lang_def, lookup_name);
508
509 unsigned int hash
510 = lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE;
511 for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash];
512 iter != NULL;
513 iter = iter->demangled_hash_next)
514 if (name_match (MSYMBOL_SEARCH_NAME (iter), lookup_name, NULL))
515 if (callback (iter))
516 return;
517 }
518 }
519
520 /* See minsyms.h. */
521
522 struct bound_minimal_symbol
523 lookup_minimal_symbol_text (const char *name, struct objfile *objf)
524 {
525 struct objfile *objfile;
526 struct minimal_symbol *msymbol;
527 struct bound_minimal_symbol found_symbol = { NULL, NULL };
528 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
529
530 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
531
532 for (objfile = object_files;
533 objfile != NULL && found_symbol.minsym == NULL;
534 objfile = objfile->next)
535 {
536 if (objf == NULL || objf == objfile
537 || objf == objfile->separate_debug_objfile_backlink)
538 {
539 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
540 msymbol != NULL && found_symbol.minsym == NULL;
541 msymbol = msymbol->hash_next)
542 {
543 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
544 (MSYMBOL_TYPE (msymbol) == mst_text
545 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
546 || MSYMBOL_TYPE (msymbol) == mst_file_text))
547 {
548 switch (MSYMBOL_TYPE (msymbol))
549 {
550 case mst_file_text:
551 found_file_symbol.minsym = msymbol;
552 found_file_symbol.objfile = objfile;
553 break;
554 default:
555 found_symbol.minsym = msymbol;
556 found_symbol.objfile = objfile;
557 break;
558 }
559 }
560 }
561 }
562 }
563 /* External symbols are best. */
564 if (found_symbol.minsym)
565 return found_symbol;
566
567 /* File-local symbols are next best. */
568 return found_file_symbol;
569 }
570
571 /* See minsyms.h. */
572
573 struct minimal_symbol *
574 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name,
575 struct objfile *objf)
576 {
577 struct objfile *objfile;
578 struct minimal_symbol *msymbol;
579
580 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
581
582 for (objfile = object_files;
583 objfile != NULL;
584 objfile = objfile->next)
585 {
586 if (objf == NULL || objf == objfile
587 || objf == objfile->separate_debug_objfile_backlink)
588 {
589 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
590 msymbol != NULL;
591 msymbol = msymbol->hash_next)
592 {
593 if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
594 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0)
595 return msymbol;
596 }
597 }
598 }
599
600 return NULL;
601 }
602
603 /* See minsyms.h. */
604
605 struct bound_minimal_symbol
606 lookup_minimal_symbol_solib_trampoline (const char *name,
607 struct objfile *objf)
608 {
609 struct objfile *objfile;
610 struct minimal_symbol *msymbol;
611 struct bound_minimal_symbol found_symbol = { NULL, NULL };
612
613 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
614
615 for (objfile = object_files;
616 objfile != NULL;
617 objfile = objfile->next)
618 {
619 if (objf == NULL || objf == objfile
620 || objf == objfile->separate_debug_objfile_backlink)
621 {
622 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
623 msymbol != NULL;
624 msymbol = msymbol->hash_next)
625 {
626 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
627 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
628 {
629 found_symbol.objfile = objfile;
630 found_symbol.minsym = msymbol;
631 return found_symbol;
632 }
633 }
634 }
635 }
636
637 return found_symbol;
638 }
639
640 /* A helper function that makes *PC section-relative. This searches
641 the sections of OBJFILE and if *PC is in a section, it subtracts
642 the section offset and returns true. Otherwise it returns
643 false. */
644
645 static int
646 frob_address (struct objfile *objfile, CORE_ADDR *pc)
647 {
648 struct obj_section *iter;
649
650 ALL_OBJFILE_OSECTIONS (objfile, iter)
651 {
652 if (*pc >= obj_section_addr (iter) && *pc < obj_section_endaddr (iter))
653 {
654 *pc -= obj_section_offset (iter);
655 return 1;
656 }
657 }
658
659 return 0;
660 }
661
662 /* Helper for lookup_minimal_symbol_by_pc_section. Convert a
663 lookup_msym_prefer to a minimal_symbol_type. */
664
665 static minimal_symbol_type
666 msym_prefer_to_msym_type (lookup_msym_prefer prefer)
667 {
668 switch (prefer)
669 {
670 case lookup_msym_prefer::TEXT:
671 return mst_text;
672 case lookup_msym_prefer::TRAMPOLINE:
673 return mst_solib_trampoline;
674 case lookup_msym_prefer::GNU_IFUNC:
675 return mst_text_gnu_ifunc;
676 }
677
678 /* Assert here instead of in a default switch case above so that
679 -Wswitch warns if a new enumerator is added. */
680 gdb_assert_not_reached ("unhandled lookup_msym_prefer");
681 }
682
683 /* Search through the minimal symbol table for each objfile and find
684 the symbol whose address is the largest address that is still less
685 than or equal to PC, and matches SECTION (which is not NULL).
686 Returns a pointer to the minimal symbol if such a symbol is found,
687 or NULL if PC is not in a suitable range.
688 Note that we need to look through ALL the minimal symbol tables
689 before deciding on the symbol that comes closest to the specified PC.
690 This is because objfiles can overlap, for example objfile A has .text
691 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
692 .data at 0x40048.
693
694 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
695 there are text and trampoline symbols at the same address.
696 Otherwise prefer mst_text symbols. */
697
698 bound_minimal_symbol
699 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section,
700 lookup_msym_prefer prefer)
701 {
702 int lo;
703 int hi;
704 int newobj;
705 struct objfile *objfile;
706 struct minimal_symbol *msymbol;
707 struct minimal_symbol *best_symbol = NULL;
708 struct objfile *best_objfile = NULL;
709 struct bound_minimal_symbol result;
710
711 if (section == NULL)
712 {
713 section = find_pc_section (pc_in);
714 if (section == NULL)
715 return {};
716 }
717
718 minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer);
719
720 /* We can not require the symbol found to be in section, because
721 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
722 symbol - but find_pc_section won't return an absolute section and
723 hence the code below would skip over absolute symbols. We can
724 still take advantage of the call to find_pc_section, though - the
725 object file still must match. In case we have separate debug
726 files, search both the file and its separate debug file. There's
727 no telling which one will have the minimal symbols. */
728
729 gdb_assert (section != NULL);
730
731 for (objfile = section->objfile;
732 objfile != NULL;
733 objfile = objfile_separate_debug_iterate (section->objfile, objfile))
734 {
735 CORE_ADDR pc = pc_in;
736
737 /* If this objfile has a minimal symbol table, go search it
738 using a binary search. */
739
740 if (objfile->per_bfd->minimal_symbol_count > 0)
741 {
742 int best_zero_sized = -1;
743
744 msymbol = objfile->per_bfd->msymbols.get ();
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 minimal_symbol_reader::~minimal_symbol_reader ()
1036 {
1037 struct msym_bunch *next;
1038
1039 while (m_msym_bunch != NULL)
1040 {
1041 next = m_msym_bunch->next;
1042 xfree (m_msym_bunch);
1043 m_msym_bunch = next;
1044 }
1045 }
1046
1047 /* See minsyms.h. */
1048
1049 void
1050 minimal_symbol_reader::record (const char *name, CORE_ADDR address,
1051 enum minimal_symbol_type ms_type)
1052 {
1053 int section;
1054
1055 switch (ms_type)
1056 {
1057 case mst_text:
1058 case mst_text_gnu_ifunc:
1059 case mst_file_text:
1060 case mst_solib_trampoline:
1061 section = SECT_OFF_TEXT (m_objfile);
1062 break;
1063 case mst_data:
1064 case mst_data_gnu_ifunc:
1065 case mst_file_data:
1066 section = SECT_OFF_DATA (m_objfile);
1067 break;
1068 case mst_bss:
1069 case mst_file_bss:
1070 section = SECT_OFF_BSS (m_objfile);
1071 break;
1072 default:
1073 section = -1;
1074 }
1075
1076 record_with_info (name, address, ms_type, section);
1077 }
1078
1079 /* Convert an enumerator of type minimal_symbol_type to its string
1080 representation. */
1081
1082 static const char *
1083 mst_str (minimal_symbol_type t)
1084 {
1085 #define MST_TO_STR(x) case x: return #x;
1086 switch (t)
1087 {
1088 MST_TO_STR (mst_unknown);
1089 MST_TO_STR (mst_text);
1090 MST_TO_STR (mst_text_gnu_ifunc);
1091 MST_TO_STR (mst_slot_got_plt);
1092 MST_TO_STR (mst_data);
1093 MST_TO_STR (mst_bss);
1094 MST_TO_STR (mst_abs);
1095 MST_TO_STR (mst_solib_trampoline);
1096 MST_TO_STR (mst_file_text);
1097 MST_TO_STR (mst_file_data);
1098 MST_TO_STR (mst_file_bss);
1099
1100 default:
1101 return "mst_???";
1102 }
1103 #undef MST_TO_STR
1104 }
1105
1106 /* See minsyms.h. */
1107
1108 struct minimal_symbol *
1109 minimal_symbol_reader::record_full (const char *name, int name_len,
1110 bool copy_name, CORE_ADDR address,
1111 enum minimal_symbol_type ms_type,
1112 int section)
1113 {
1114 struct msym_bunch *newobj;
1115 struct minimal_symbol *msymbol;
1116
1117 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
1118 the minimal symbols, because if there is also another symbol
1119 at the same address (e.g. the first function of the file),
1120 lookup_minimal_symbol_by_pc would have no way of getting the
1121 right one. */
1122 if (ms_type == mst_file_text && name[0] == 'g'
1123 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
1124 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
1125 return (NULL);
1126
1127 /* It's safe to strip the leading char here once, since the name
1128 is also stored stripped in the minimal symbol table. */
1129 if (name[0] == get_symbol_leading_char (m_objfile->obfd))
1130 {
1131 ++name;
1132 --name_len;
1133 }
1134
1135 if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
1136 return (NULL);
1137
1138 if (symtab_create_debug >= 2)
1139 printf_unfiltered ("Recording minsym: %-21s %18s %4d %s\n",
1140 mst_str (ms_type), hex_string (address), section, name);
1141
1142 if (m_msym_bunch_index == BUNCH_SIZE)
1143 {
1144 newobj = XCNEW (struct msym_bunch);
1145 m_msym_bunch_index = 0;
1146 newobj->next = m_msym_bunch;
1147 m_msym_bunch = newobj;
1148 }
1149 msymbol = &m_msym_bunch->contents[m_msym_bunch_index];
1150 symbol_set_language (msymbol, language_auto,
1151 &m_objfile->per_bfd->storage_obstack);
1152 symbol_set_names (msymbol, name, name_len, copy_name, m_objfile->per_bfd);
1153
1154 SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
1155 MSYMBOL_SECTION (msymbol) = section;
1156
1157 MSYMBOL_TYPE (msymbol) = ms_type;
1158
1159 /* If we already read minimal symbols for this objfile, then don't
1160 ever allocate a new one. */
1161 if (!m_objfile->per_bfd->minsyms_read)
1162 {
1163 m_msym_bunch_index++;
1164 m_objfile->per_bfd->n_minsyms++;
1165 }
1166 m_msym_count++;
1167 return msymbol;
1168 }
1169
1170 /* Compare two minimal symbols by address and return a signed result based
1171 on unsigned comparisons, so that we sort into unsigned numeric order.
1172 Within groups with the same address, sort by name. */
1173
1174 static int
1175 compare_minimal_symbols (const void *fn1p, const void *fn2p)
1176 {
1177 const struct minimal_symbol *fn1;
1178 const struct minimal_symbol *fn2;
1179
1180 fn1 = (const struct minimal_symbol *) fn1p;
1181 fn2 = (const struct minimal_symbol *) fn2p;
1182
1183 if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) < MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1184 {
1185 return (-1); /* addr 1 is less than addr 2. */
1186 }
1187 else if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) > MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1188 {
1189 return (1); /* addr 1 is greater than addr 2. */
1190 }
1191 else
1192 /* addrs are equal: sort by name */
1193 {
1194 const char *name1 = MSYMBOL_LINKAGE_NAME (fn1);
1195 const char *name2 = MSYMBOL_LINKAGE_NAME (fn2);
1196
1197 if (name1 && name2) /* both have names */
1198 return strcmp (name1, name2);
1199 else if (name2)
1200 return 1; /* fn1 has no name, so it is "less". */
1201 else if (name1) /* fn2 has no name, so it is "less". */
1202 return -1;
1203 else
1204 return (0); /* Neither has a name, so they're equal. */
1205 }
1206 }
1207
1208 /* Compact duplicate entries out of a minimal symbol table by walking
1209 through the table and compacting out entries with duplicate addresses
1210 and matching names. Return the number of entries remaining.
1211
1212 On entry, the table resides between msymbol[0] and msymbol[mcount].
1213 On exit, it resides between msymbol[0] and msymbol[result_count].
1214
1215 When files contain multiple sources of symbol information, it is
1216 possible for the minimal symbol table to contain many duplicate entries.
1217 As an example, SVR4 systems use ELF formatted object files, which
1218 usually contain at least two different types of symbol tables (a
1219 standard ELF one and a smaller dynamic linking table), as well as
1220 DWARF debugging information for files compiled with -g.
1221
1222 Without compacting, the minimal symbol table for gdb itself contains
1223 over a 1000 duplicates, about a third of the total table size. Aside
1224 from the potential trap of not noticing that two successive entries
1225 identify the same location, this duplication impacts the time required
1226 to linearly scan the table, which is done in a number of places. So we
1227 just do one linear scan here and toss out the duplicates.
1228
1229 Since the different sources of information for each symbol may
1230 have different levels of "completeness", we may have duplicates
1231 that have one entry with type "mst_unknown" and the other with a
1232 known type. So if the one we are leaving alone has type mst_unknown,
1233 overwrite its type with the type from the one we are compacting out. */
1234
1235 static int
1236 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
1237 struct objfile *objfile)
1238 {
1239 struct minimal_symbol *copyfrom;
1240 struct minimal_symbol *copyto;
1241
1242 if (mcount > 0)
1243 {
1244 copyfrom = copyto = msymbol;
1245 while (copyfrom < msymbol + mcount - 1)
1246 {
1247 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
1248 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
1249 && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
1250 && strcmp (MSYMBOL_LINKAGE_NAME (copyfrom),
1251 MSYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0)
1252 {
1253 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
1254 {
1255 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
1256 }
1257 copyfrom++;
1258 }
1259 else
1260 *copyto++ = *copyfrom++;
1261 }
1262 *copyto++ = *copyfrom++;
1263 mcount = copyto - msymbol;
1264 }
1265 return (mcount);
1266 }
1267
1268 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1269 after compacting or sorting the table since the entries move around
1270 thus causing the internal minimal_symbol pointers to become jumbled. */
1271
1272 static void
1273 build_minimal_symbol_hash_tables (struct objfile *objfile)
1274 {
1275 int i;
1276 struct minimal_symbol *msym;
1277
1278 /* Clear the hash tables. */
1279 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
1280 {
1281 objfile->per_bfd->msymbol_hash[i] = 0;
1282 objfile->per_bfd->msymbol_demangled_hash[i] = 0;
1283 }
1284
1285 /* Now, (re)insert the actual entries. */
1286 for ((i = objfile->per_bfd->minimal_symbol_count,
1287 msym = objfile->per_bfd->msymbols.get ());
1288 i > 0;
1289 i--, msym++)
1290 {
1291 msym->hash_next = 0;
1292 add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash);
1293
1294 msym->demangled_hash_next = 0;
1295 if (MSYMBOL_SEARCH_NAME (msym) != MSYMBOL_LINKAGE_NAME (msym))
1296 add_minsym_to_demangled_hash_table (msym, objfile);
1297 }
1298 }
1299
1300 /* Add the minimal symbols in the existing bunches to the objfile's official
1301 minimal symbol table. In most cases there is no minimal symbol table yet
1302 for this objfile, and the existing bunches are used to create one. Once
1303 in a while (for shared libraries for example), we add symbols (e.g. common
1304 symbols) to an existing objfile. */
1305
1306 void
1307 minimal_symbol_reader::install ()
1308 {
1309 int mcount;
1310 struct msym_bunch *bunch;
1311 struct minimal_symbol *msymbols;
1312 int alloc_count;
1313
1314 if (m_objfile->per_bfd->minsyms_read)
1315 return;
1316
1317 if (m_msym_count > 0)
1318 {
1319 if (symtab_create_debug)
1320 {
1321 fprintf_unfiltered (gdb_stdlog,
1322 "Installing %d minimal symbols of objfile %s.\n",
1323 m_msym_count, objfile_name (m_objfile));
1324 }
1325
1326 /* Allocate enough space, into which we will gather the bunches
1327 of new and existing minimal symbols, sort them, and then
1328 compact out the duplicate entries. Once we have a final
1329 table, we will give back the excess space. */
1330
1331 alloc_count = m_msym_count + m_objfile->per_bfd->minimal_symbol_count;
1332 gdb::unique_xmalloc_ptr<minimal_symbol>
1333 msym_holder (XNEWVEC (minimal_symbol, alloc_count));
1334 msymbols = msym_holder.get ();
1335
1336 /* Copy in the existing minimal symbols, if there are any. */
1337
1338 if (m_objfile->per_bfd->minimal_symbol_count)
1339 memcpy (msymbols, m_objfile->per_bfd->msymbols.get (),
1340 m_objfile->per_bfd->minimal_symbol_count
1341 * sizeof (struct minimal_symbol));
1342
1343 /* Walk through the list of minimal symbol bunches, adding each symbol
1344 to the new contiguous array of symbols. Note that we start with the
1345 current, possibly partially filled bunch (thus we use the current
1346 msym_bunch_index for the first bunch we copy over), and thereafter
1347 each bunch is full. */
1348
1349 mcount = m_objfile->per_bfd->minimal_symbol_count;
1350
1351 for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next)
1352 {
1353 memcpy (&msymbols[mcount], &bunch->contents[0],
1354 m_msym_bunch_index * sizeof (struct minimal_symbol));
1355 mcount += m_msym_bunch_index;
1356 m_msym_bunch_index = BUNCH_SIZE;
1357 }
1358
1359 /* Sort the minimal symbols by address. */
1360
1361 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
1362 compare_minimal_symbols);
1363
1364 /* Compact out any duplicates, and free up whatever space we are
1365 no longer using. */
1366
1367 mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
1368 msym_holder.reset (XRESIZEVEC (struct minimal_symbol,
1369 msym_holder.release (),
1370 mcount));
1371
1372 /* Attach the minimal symbol table to the specified objfile.
1373 The strings themselves are also located in the storage_obstack
1374 of this objfile. */
1375
1376 m_objfile->per_bfd->minimal_symbol_count = mcount;
1377 m_objfile->per_bfd->msymbols = std::move (msym_holder);
1378
1379 build_minimal_symbol_hash_tables (m_objfile);
1380 }
1381 }
1382
1383 /* Check if PC is in a shared library trampoline code stub.
1384 Return minimal symbol for the trampoline entry or NULL if PC is not
1385 in a trampoline code stub. */
1386
1387 static struct minimal_symbol *
1388 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
1389 {
1390 bound_minimal_symbol msymbol
1391 = lookup_minimal_symbol_by_pc_section (pc, NULL,
1392 lookup_msym_prefer::TRAMPOLINE);
1393
1394 if (msymbol.minsym != NULL
1395 && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
1396 return msymbol.minsym;
1397 return NULL;
1398 }
1399
1400 /* If PC is in a shared library trampoline code stub, return the
1401 address of the `real' function belonging to the stub.
1402 Return 0 if PC is not in a trampoline code stub or if the real
1403 function is not found in the minimal symbol table.
1404
1405 We may fail to find the right function if a function with the
1406 same name is defined in more than one shared library, but this
1407 is considered bad programming style. We could return 0 if we find
1408 a duplicate function in case this matters someday. */
1409
1410 CORE_ADDR
1411 find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
1412 {
1413 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1414
1415 if (tsymbol != NULL)
1416 {
1417 for (objfile *objfile : current_program_space->objfiles ())
1418 {
1419 for (minimal_symbol *msymbol : objfile->msymbols ())
1420 {
1421 /* Also handle minimal symbols pointing to function
1422 descriptors. */
1423 if ((MSYMBOL_TYPE (msymbol) == mst_text
1424 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
1425 || MSYMBOL_TYPE (msymbol) == mst_data
1426 || MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc)
1427 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol),
1428 MSYMBOL_LINKAGE_NAME (tsymbol)) == 0)
1429 {
1430 CORE_ADDR func;
1431
1432 /* Ignore data symbols that are not function
1433 descriptors. */
1434 if (msymbol_is_function (objfile, msymbol, &func))
1435 return func;
1436 }
1437 }
1438 }
1439 }
1440 return 0;
1441 }
1442
1443 /* See minsyms.h. */
1444
1445 CORE_ADDR
1446 minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
1447 {
1448 int i;
1449 short section;
1450 struct obj_section *obj_section;
1451 CORE_ADDR result;
1452 struct minimal_symbol *msymbol;
1453
1454 gdb_assert (minsym.minsym != NULL);
1455
1456 /* If the minimal symbol has a size, use it. Otherwise use the
1457 lesser of the next minimal symbol in the same section, or the end
1458 of the section, as the end of the function. */
1459
1460 if (MSYMBOL_SIZE (minsym.minsym) != 0)
1461 return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
1462
1463 /* Step over other symbols at this same address, and symbols in
1464 other sections, to find the next symbol in this section with a
1465 different address. */
1466
1467 msymbol = minsym.minsym;
1468 section = MSYMBOL_SECTION (msymbol);
1469 for (i = 1; MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++)
1470 {
1471 if ((MSYMBOL_VALUE_RAW_ADDRESS (msymbol + i)
1472 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
1473 && MSYMBOL_SECTION (msymbol + i) == section)
1474 break;
1475 }
1476
1477 obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
1478 if (MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL
1479 && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i)
1480 < obj_section_endaddr (obj_section)))
1481 result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i);
1482 else
1483 /* We got the start address from the last msymbol in the objfile.
1484 So the end address is the end of the section. */
1485 result = obj_section_endaddr (obj_section);
1486
1487 return result;
1488 }
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