Handle CRLF when reading XML on Windows
[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 "gdbsupport/symbol.h"
54 #include <algorithm>
55 #include "safe-ctype.h"
56 #include "gdbsupport/parallel-for.h"
57
58 #if CXX_STD_THREAD
59 #include <mutex>
60 #endif
61
62 /* See minsyms.h. */
63
64 bool
65 msymbol_is_function (struct objfile *objfile, minimal_symbol *minsym,
66 CORE_ADDR *func_address_p)
67 {
68 CORE_ADDR msym_addr = MSYMBOL_VALUE_ADDRESS (objfile, minsym);
69
70 switch (minsym->type)
71 {
72 case mst_slot_got_plt:
73 case mst_data:
74 case mst_bss:
75 case mst_abs:
76 case mst_file_data:
77 case mst_file_bss:
78 case mst_data_gnu_ifunc:
79 {
80 struct gdbarch *gdbarch = get_objfile_arch (objfile);
81 CORE_ADDR pc
82 = gdbarch_convert_from_func_ptr_addr (gdbarch, msym_addr,
83 current_top_target ());
84 if (pc != msym_addr)
85 {
86 if (func_address_p != NULL)
87 *func_address_p = pc;
88 return true;
89 }
90 return false;
91 }
92 default:
93 if (func_address_p != NULL)
94 *func_address_p = msym_addr;
95 return true;
96 }
97 }
98
99 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
100 At the end, copy them all into one newly allocated array. */
101
102 #define BUNCH_SIZE 127
103
104 struct msym_bunch
105 {
106 struct msym_bunch *next;
107 struct minimal_symbol contents[BUNCH_SIZE];
108 };
109
110 /* See minsyms.h. */
111
112 unsigned int
113 msymbol_hash_iw (const char *string)
114 {
115 unsigned int hash = 0;
116
117 while (*string && *string != '(')
118 {
119 string = skip_spaces (string);
120 if (*string && *string != '(')
121 {
122 hash = SYMBOL_HASH_NEXT (hash, *string);
123 ++string;
124 }
125 }
126 return hash;
127 }
128
129 /* See minsyms.h. */
130
131 unsigned int
132 msymbol_hash (const char *string)
133 {
134 unsigned int hash = 0;
135
136 for (; *string; ++string)
137 hash = SYMBOL_HASH_NEXT (hash, *string);
138 return hash;
139 }
140
141 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
142 static void
143 add_minsym_to_hash_table (struct minimal_symbol *sym,
144 struct minimal_symbol **table,
145 unsigned int hash_value)
146 {
147 if (sym->hash_next == NULL)
148 {
149 unsigned int hash = hash_value % MINIMAL_SYMBOL_HASH_SIZE;
150
151 sym->hash_next = table[hash];
152 table[hash] = sym;
153 }
154 }
155
156 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
157 TABLE. */
158 static void
159 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
160 struct objfile *objfile,
161 unsigned int hash_value)
162 {
163 if (sym->demangled_hash_next == NULL)
164 {
165 objfile->per_bfd->demangled_hash_languages.set (sym->language ());
166
167 struct minimal_symbol **table
168 = objfile->per_bfd->msymbol_demangled_hash;
169 unsigned int hash_index = hash_value % MINIMAL_SYMBOL_HASH_SIZE;
170 sym->demangled_hash_next = table[hash_index];
171 table[hash_index] = sym;
172 }
173 }
174
175 /* Worker object for lookup_minimal_symbol. Stores temporary results
176 while walking the symbol tables. */
177
178 struct found_minimal_symbols
179 {
180 /* External symbols are best. */
181 bound_minimal_symbol external_symbol {};
182
183 /* File-local symbols are next best. */
184 bound_minimal_symbol file_symbol {};
185
186 /* Symbols for shared library trampolines are next best. */
187 bound_minimal_symbol trampoline_symbol {};
188
189 /* Called when a symbol name matches. Check if the minsym is a
190 better type than what we had already found, and record it in one
191 of the members fields if so. Returns true if we collected the
192 real symbol, in which case we can stop searching. */
193 bool maybe_collect (const char *sfile, objfile *objf,
194 minimal_symbol *msymbol);
195 };
196
197 /* See declaration above. */
198
199 bool
200 found_minimal_symbols::maybe_collect (const char *sfile,
201 struct objfile *objfile,
202 minimal_symbol *msymbol)
203 {
204 switch (MSYMBOL_TYPE (msymbol))
205 {
206 case mst_file_text:
207 case mst_file_data:
208 case mst_file_bss:
209 if (sfile == NULL
210 || filename_cmp (msymbol->filename, sfile) == 0)
211 {
212 file_symbol.minsym = msymbol;
213 file_symbol.objfile = objfile;
214 }
215 break;
216
217 case mst_solib_trampoline:
218
219 /* If a trampoline symbol is found, we prefer to keep
220 looking for the *real* symbol. If the actual symbol
221 is not found, then we'll use the trampoline
222 entry. */
223 if (trampoline_symbol.minsym == NULL)
224 {
225 trampoline_symbol.minsym = msymbol;
226 trampoline_symbol.objfile = objfile;
227 }
228 break;
229
230 case mst_unknown:
231 default:
232 external_symbol.minsym = msymbol;
233 external_symbol.objfile = objfile;
234 /* We have the real symbol. No use looking further. */
235 return true;
236 }
237
238 /* Keep looking. */
239 return false;
240 }
241
242 /* Walk the mangled name hash table, and pass each symbol whose name
243 matches LOOKUP_NAME according to NAMECMP to FOUND. */
244
245 static void
246 lookup_minimal_symbol_mangled (const char *lookup_name,
247 const char *sfile,
248 struct objfile *objfile,
249 struct minimal_symbol **table,
250 unsigned int hash,
251 int (*namecmp) (const char *, const char *),
252 found_minimal_symbols &found)
253 {
254 for (minimal_symbol *msymbol = table[hash];
255 msymbol != NULL;
256 msymbol = msymbol->hash_next)
257 {
258 const char *symbol_name = msymbol->linkage_name ();
259
260 if (namecmp (symbol_name, lookup_name) == 0
261 && found.maybe_collect (sfile, objfile, msymbol))
262 return;
263 }
264 }
265
266 /* Walk the demangled name hash table, and pass each symbol whose name
267 matches LOOKUP_NAME according to MATCHER to FOUND. */
268
269 static void
270 lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name,
271 const char *sfile,
272 struct objfile *objfile,
273 struct minimal_symbol **table,
274 unsigned int hash,
275 symbol_name_matcher_ftype *matcher,
276 found_minimal_symbols &found)
277 {
278 for (minimal_symbol *msymbol = table[hash];
279 msymbol != NULL;
280 msymbol = msymbol->demangled_hash_next)
281 {
282 const char *symbol_name = msymbol->search_name ();
283
284 if (matcher (symbol_name, lookup_name, NULL)
285 && found.maybe_collect (sfile, objfile, msymbol))
286 return;
287 }
288 }
289
290 /* Look through all the current minimal symbol tables and find the
291 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
292 the search to that objfile. If SFILE is non-NULL, the only file-scope
293 symbols considered will be from that source file (global symbols are
294 still preferred). Returns a pointer to the minimal symbol that
295 matches, or NULL if no match is found.
296
297 Note: One instance where there may be duplicate minimal symbols with
298 the same name is when the symbol tables for a shared library and the
299 symbol tables for an executable contain global symbols with the same
300 names (the dynamic linker deals with the duplication).
301
302 It's also possible to have minimal symbols with different mangled
303 names, but identical demangled names. For example, the GNU C++ v3
304 ABI requires the generation of two (or perhaps three) copies of
305 constructor functions --- "in-charge", "not-in-charge", and
306 "allocate" copies; destructors may be duplicated as well.
307 Obviously, there must be distinct mangled names for each of these,
308 but the demangled names are all the same: S::S or S::~S. */
309
310 struct bound_minimal_symbol
311 lookup_minimal_symbol (const char *name, const char *sfile,
312 struct objfile *objf)
313 {
314 found_minimal_symbols found;
315
316 unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
317
318 auto *mangled_cmp
319 = (case_sensitivity == case_sensitive_on
320 ? strcmp
321 : strcasecmp);
322
323 if (sfile != NULL)
324 sfile = lbasename (sfile);
325
326 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
327
328 for (objfile *objfile : current_program_space->objfiles ())
329 {
330 if (found.external_symbol.minsym != NULL)
331 break;
332
333 if (objf == NULL || objf == objfile
334 || objf == objfile->separate_debug_objfile_backlink)
335 {
336 if (symbol_lookup_debug)
337 {
338 fprintf_unfiltered (gdb_stdlog,
339 "lookup_minimal_symbol (%s, %s, %s)\n",
340 name, sfile != NULL ? sfile : "NULL",
341 objfile_debug_name (objfile));
342 }
343
344 /* Do two passes: the first over the ordinary hash table,
345 and the second over the demangled hash table. */
346 lookup_minimal_symbol_mangled (name, sfile, objfile,
347 objfile->per_bfd->msymbol_hash,
348 mangled_hash, mangled_cmp, found);
349
350 /* If not found, try the demangled hash table. */
351 if (found.external_symbol.minsym == NULL)
352 {
353 /* Once for each language in the demangled hash names
354 table (usually just zero or one languages). */
355 for (unsigned iter = 0; iter < nr_languages; ++iter)
356 {
357 if (!objfile->per_bfd->demangled_hash_languages.test (iter))
358 continue;
359 enum language lang = (enum language) iter;
360
361 unsigned int hash
362 = (lookup_name.search_name_hash (lang)
363 % MINIMAL_SYMBOL_HASH_SIZE);
364
365 symbol_name_matcher_ftype *match
366 = get_symbol_name_matcher (language_def (lang),
367 lookup_name);
368 struct minimal_symbol **msymbol_demangled_hash
369 = objfile->per_bfd->msymbol_demangled_hash;
370
371 lookup_minimal_symbol_demangled (lookup_name, sfile, objfile,
372 msymbol_demangled_hash,
373 hash, match, found);
374
375 if (found.external_symbol.minsym != NULL)
376 break;
377 }
378 }
379 }
380 }
381
382 /* External symbols are best. */
383 if (found.external_symbol.minsym != NULL)
384 {
385 if (symbol_lookup_debug)
386 {
387 minimal_symbol *minsym = found.external_symbol.minsym;
388
389 fprintf_unfiltered (gdb_stdlog,
390 "lookup_minimal_symbol (...) = %s (external)\n",
391 host_address_to_string (minsym));
392 }
393 return found.external_symbol;
394 }
395
396 /* File-local symbols are next best. */
397 if (found.file_symbol.minsym != NULL)
398 {
399 if (symbol_lookup_debug)
400 {
401 minimal_symbol *minsym = found.file_symbol.minsym;
402
403 fprintf_unfiltered (gdb_stdlog,
404 "lookup_minimal_symbol (...) = %s (file-local)\n",
405 host_address_to_string (minsym));
406 }
407 return found.file_symbol;
408 }
409
410 /* Symbols for shared library trampolines are next best. */
411 if (found.trampoline_symbol.minsym != NULL)
412 {
413 if (symbol_lookup_debug)
414 {
415 minimal_symbol *minsym = found.trampoline_symbol.minsym;
416
417 fprintf_unfiltered (gdb_stdlog,
418 "lookup_minimal_symbol (...) = %s (trampoline)\n",
419 host_address_to_string (minsym));
420 }
421
422 return found.trampoline_symbol;
423 }
424
425 /* Not found. */
426 if (symbol_lookup_debug)
427 fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
428 return {};
429 }
430
431 /* See minsyms.h. */
432
433 struct bound_minimal_symbol
434 lookup_bound_minimal_symbol (const char *name)
435 {
436 return lookup_minimal_symbol (name, NULL, NULL);
437 }
438
439 /* See gdbsupport/symbol.h. */
440
441 int
442 find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
443 struct objfile *objfile)
444 {
445 struct bound_minimal_symbol sym
446 = lookup_minimal_symbol (name, NULL, objfile);
447
448 if (sym.minsym != NULL)
449 *addr = BMSYMBOL_VALUE_ADDRESS (sym);
450
451 return sym.minsym == NULL;
452 }
453
454 /* Get the lookup name form best suitable for linkage name
455 matching. */
456
457 static const char *
458 linkage_name_str (const lookup_name_info &lookup_name)
459 {
460 /* Unlike most languages (including C++), Ada uses the
461 encoded/linkage name as the search name recorded in symbols. So
462 if debugging in Ada mode, prefer the Ada-encoded name. This also
463 makes Ada's verbatim match syntax ("<...>") work, because
464 "lookup_name.name()" includes the "<>"s, while
465 "lookup_name.ada().lookup_name()" is the encoded name with "<>"s
466 stripped. */
467 if (current_language->la_language == language_ada)
468 return lookup_name.ada ().lookup_name ().c_str ();
469
470 return lookup_name.name ().c_str ();
471 }
472
473 /* See minsyms.h. */
474
475 void
476 iterate_over_minimal_symbols
477 (struct objfile *objf, const lookup_name_info &lookup_name,
478 gdb::function_view<bool (struct minimal_symbol *)> callback)
479 {
480 /* The first pass is over the ordinary hash table. */
481 {
482 const char *name = linkage_name_str (lookup_name);
483 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
484 auto *mangled_cmp
485 = (case_sensitivity == case_sensitive_on
486 ? strcmp
487 : strcasecmp);
488
489 for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash];
490 iter != NULL;
491 iter = iter->hash_next)
492 {
493 if (mangled_cmp (iter->linkage_name (), name) == 0)
494 if (callback (iter))
495 return;
496 }
497 }
498
499 /* The second pass is over the demangled table. Once for each
500 language in the demangled hash names table (usually just zero or
501 one). */
502 for (unsigned liter = 0; liter < nr_languages; ++liter)
503 {
504 if (!objf->per_bfd->demangled_hash_languages.test (liter))
505 continue;
506
507 enum language lang = (enum language) liter;
508 const language_defn *lang_def = language_def (lang);
509 symbol_name_matcher_ftype *name_match
510 = get_symbol_name_matcher (lang_def, lookup_name);
511
512 unsigned int hash
513 = lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE;
514 for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash];
515 iter != NULL;
516 iter = iter->demangled_hash_next)
517 if (name_match (iter->search_name (), lookup_name, NULL))
518 if (callback (iter))
519 return;
520 }
521 }
522
523 /* See minsyms.h. */
524
525 bound_minimal_symbol
526 lookup_minimal_symbol_linkage (const char *name, struct objfile *objf)
527 {
528 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
529
530 for (objfile *objfile : objf->separate_debug_objfiles ())
531 {
532 for (minimal_symbol *msymbol = objfile->per_bfd->msymbol_hash[hash];
533 msymbol != NULL;
534 msymbol = msymbol->hash_next)
535 {
536 if (strcmp (msymbol->linkage_name (), name) == 0
537 && (MSYMBOL_TYPE (msymbol) == mst_data
538 || MSYMBOL_TYPE (msymbol) == mst_bss))
539 return {msymbol, objfile};
540 }
541 }
542
543 return {};
544 }
545
546 /* See minsyms.h. */
547
548 struct bound_minimal_symbol
549 lookup_minimal_symbol_text (const char *name, struct objfile *objf)
550 {
551 struct minimal_symbol *msymbol;
552 struct bound_minimal_symbol found_symbol = { NULL, NULL };
553 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
554
555 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
556
557 for (objfile *objfile : current_program_space->objfiles ())
558 {
559 if (found_symbol.minsym != NULL)
560 break;
561
562 if (objf == NULL || objf == objfile
563 || objf == objfile->separate_debug_objfile_backlink)
564 {
565 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
566 msymbol != NULL && found_symbol.minsym == NULL;
567 msymbol = msymbol->hash_next)
568 {
569 if (strcmp (msymbol->linkage_name (), name) == 0 &&
570 (MSYMBOL_TYPE (msymbol) == mst_text
571 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
572 || MSYMBOL_TYPE (msymbol) == mst_file_text))
573 {
574 switch (MSYMBOL_TYPE (msymbol))
575 {
576 case mst_file_text:
577 found_file_symbol.minsym = msymbol;
578 found_file_symbol.objfile = objfile;
579 break;
580 default:
581 found_symbol.minsym = msymbol;
582 found_symbol.objfile = objfile;
583 break;
584 }
585 }
586 }
587 }
588 }
589 /* External symbols are best. */
590 if (found_symbol.minsym)
591 return found_symbol;
592
593 /* File-local symbols are next best. */
594 return found_file_symbol;
595 }
596
597 /* See minsyms.h. */
598
599 struct minimal_symbol *
600 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name,
601 struct objfile *objf)
602 {
603 struct minimal_symbol *msymbol;
604
605 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
606
607 for (objfile *objfile : current_program_space->objfiles ())
608 {
609 if (objf == NULL || objf == objfile
610 || objf == objfile->separate_debug_objfile_backlink)
611 {
612 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
613 msymbol != NULL;
614 msymbol = msymbol->hash_next)
615 {
616 if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
617 && strcmp (msymbol->linkage_name (), name) == 0)
618 return msymbol;
619 }
620 }
621 }
622
623 return NULL;
624 }
625
626 /* A helper function that makes *PC section-relative. This searches
627 the sections of OBJFILE and if *PC is in a section, it subtracts
628 the section offset and returns true. Otherwise it returns
629 false. */
630
631 static int
632 frob_address (struct objfile *objfile, CORE_ADDR *pc)
633 {
634 struct obj_section *iter;
635
636 ALL_OBJFILE_OSECTIONS (objfile, iter)
637 {
638 if (*pc >= obj_section_addr (iter) && *pc < obj_section_endaddr (iter))
639 {
640 *pc -= obj_section_offset (iter);
641 return 1;
642 }
643 }
644
645 return 0;
646 }
647
648 /* Helper for lookup_minimal_symbol_by_pc_section. Convert a
649 lookup_msym_prefer to a minimal_symbol_type. */
650
651 static minimal_symbol_type
652 msym_prefer_to_msym_type (lookup_msym_prefer prefer)
653 {
654 switch (prefer)
655 {
656 case lookup_msym_prefer::TEXT:
657 return mst_text;
658 case lookup_msym_prefer::TRAMPOLINE:
659 return mst_solib_trampoline;
660 case lookup_msym_prefer::GNU_IFUNC:
661 return mst_text_gnu_ifunc;
662 }
663
664 /* Assert here instead of in a default switch case above so that
665 -Wswitch warns if a new enumerator is added. */
666 gdb_assert_not_reached ("unhandled lookup_msym_prefer");
667 }
668
669 /* Search through the minimal symbol table for each objfile and find
670 the symbol whose address is the largest address that is still less
671 than or equal to PC, and matches SECTION (which is not NULL).
672 Returns a pointer to the minimal symbol if such a symbol is found,
673 or NULL if PC is not in a suitable range.
674 Note that we need to look through ALL the minimal symbol tables
675 before deciding on the symbol that comes closest to the specified PC.
676 This is because objfiles can overlap, for example objfile A has .text
677 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
678 .data at 0x40048.
679
680 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
681 there are text and trampoline symbols at the same address.
682 Otherwise prefer mst_text symbols. */
683
684 bound_minimal_symbol
685 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section,
686 lookup_msym_prefer prefer)
687 {
688 int lo;
689 int hi;
690 int newobj;
691 struct minimal_symbol *msymbol;
692 struct minimal_symbol *best_symbol = NULL;
693 struct objfile *best_objfile = NULL;
694 struct bound_minimal_symbol result;
695
696 if (section == NULL)
697 {
698 section = find_pc_section (pc_in);
699 if (section == NULL)
700 return {};
701 }
702
703 minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer);
704
705 /* We can not require the symbol found to be in section, because
706 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
707 symbol - but find_pc_section won't return an absolute section and
708 hence the code below would skip over absolute symbols. We can
709 still take advantage of the call to find_pc_section, though - the
710 object file still must match. In case we have separate debug
711 files, search both the file and its separate debug file. There's
712 no telling which one will have the minimal symbols. */
713
714 gdb_assert (section != NULL);
715
716 for (objfile *objfile : section->objfile->separate_debug_objfiles ())
717 {
718 CORE_ADDR pc = pc_in;
719
720 /* If this objfile has a minimal symbol table, go search it
721 using a binary search. */
722
723 if (objfile->per_bfd->minimal_symbol_count > 0)
724 {
725 int best_zero_sized = -1;
726
727 msymbol = objfile->per_bfd->msymbols.get ();
728 lo = 0;
729 hi = objfile->per_bfd->minimal_symbol_count - 1;
730
731 /* This code assumes that the minimal symbols are sorted by
732 ascending address values. If the pc value is greater than or
733 equal to the first symbol's address, then some symbol in this
734 minimal symbol table is a suitable candidate for being the
735 "best" symbol. This includes the last real symbol, for cases
736 where the pc value is larger than any address in this vector.
737
738 By iterating until the address associated with the current
739 hi index (the endpoint of the test interval) is less than
740 or equal to the desired pc value, we accomplish two things:
741 (1) the case where the pc value is larger than any minimal
742 symbol address is trivially solved, (2) the address associated
743 with the hi index is always the one we want when the iteration
744 terminates. In essence, we are iterating the test interval
745 down until the pc value is pushed out of it from the high end.
746
747 Warning: this code is trickier than it would appear at first. */
748
749 if (frob_address (objfile, &pc)
750 && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo]))
751 {
752 while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc)
753 {
754 /* pc is still strictly less than highest address. */
755 /* Note "new" will always be >= lo. */
756 newobj = (lo + hi) / 2;
757 if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc)
758 || (lo == newobj))
759 {
760 hi = newobj;
761 }
762 else
763 {
764 lo = newobj;
765 }
766 }
767
768 /* If we have multiple symbols at the same address, we want
769 hi to point to the last one. That way we can find the
770 right symbol if it has an index greater than hi. */
771 while (hi < objfile->per_bfd->minimal_symbol_count - 1
772 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
773 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1])))
774 hi++;
775
776 /* Skip various undesirable symbols. */
777 while (hi >= 0)
778 {
779 /* Skip any absolute symbols. This is apparently
780 what adb and dbx do, and is needed for the CM-5.
781 There are two known possible problems: (1) on
782 ELF, apparently end, edata, etc. are absolute.
783 Not sure ignoring them here is a big deal, but if
784 we want to use them, the fix would go in
785 elfread.c. (2) I think shared library entry
786 points on the NeXT are absolute. If we want
787 special handling for this it probably should be
788 triggered by a special mst_abs_or_lib or some
789 such. */
790
791 if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs)
792 {
793 hi--;
794 continue;
795 }
796
797 /* If SECTION was specified, skip any symbol from
798 wrong section. */
799 if (section
800 /* Some types of debug info, such as COFF,
801 don't fill the bfd_section member, so don't
802 throw away symbols on those platforms. */
803 && MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]) != NULL
804 && (!matching_obj_sections
805 (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]),
806 section)))
807 {
808 hi--;
809 continue;
810 }
811
812 /* If we are looking for a trampoline and this is a
813 text symbol, or the other way around, check the
814 preceding symbol too. If they are otherwise
815 identical prefer that one. */
816 if (hi > 0
817 && MSYMBOL_TYPE (&msymbol[hi]) != want_type
818 && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type
819 && (MSYMBOL_SIZE (&msymbol[hi])
820 == MSYMBOL_SIZE (&msymbol[hi - 1]))
821 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
822 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]))
823 && (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi])
824 == MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi - 1])))
825 {
826 hi--;
827 continue;
828 }
829
830 /* If the minimal symbol has a zero size, save it
831 but keep scanning backwards looking for one with
832 a non-zero size. A zero size may mean that the
833 symbol isn't an object or function (e.g. a
834 label), or it may just mean that the size was not
835 specified. */
836 if (MSYMBOL_SIZE (&msymbol[hi]) == 0)
837 {
838 if (best_zero_sized == -1)
839 best_zero_sized = hi;
840 hi--;
841 continue;
842 }
843
844 /* If we are past the end of the current symbol, try
845 the previous symbol if it has a larger overlapping
846 size. This happens on i686-pc-linux-gnu with glibc;
847 the nocancel variants of system calls are inside
848 the cancellable variants, but both have sizes. */
849 if (hi > 0
850 && MSYMBOL_SIZE (&msymbol[hi]) != 0
851 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
852 + MSYMBOL_SIZE (&msymbol[hi]))
853 && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])
854 + MSYMBOL_SIZE (&msymbol[hi - 1])))
855 {
856 hi--;
857 continue;
858 }
859
860 /* Otherwise, this symbol must be as good as we're going
861 to get. */
862 break;
863 }
864
865 /* If HI has a zero size, and best_zero_sized is set,
866 then we had two or more zero-sized symbols; prefer
867 the first one we found (which may have a higher
868 address). Also, if we ran off the end, be sure
869 to back up. */
870 if (best_zero_sized != -1
871 && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
872 hi = best_zero_sized;
873
874 /* If the minimal symbol has a non-zero size, and this
875 PC appears to be outside the symbol's contents, then
876 refuse to use this symbol. If we found a zero-sized
877 symbol with an address greater than this symbol's,
878 use that instead. We assume that if symbols have
879 specified sizes, they do not overlap. */
880
881 if (hi >= 0
882 && MSYMBOL_SIZE (&msymbol[hi]) != 0
883 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
884 + MSYMBOL_SIZE (&msymbol[hi])))
885 {
886 if (best_zero_sized != -1)
887 hi = best_zero_sized;
888 else
889 /* Go on to the next object file. */
890 continue;
891 }
892
893 /* The minimal symbol indexed by hi now is the best one in this
894 objfile's minimal symbol table. See if it is the best one
895 overall. */
896
897 if (hi >= 0
898 && ((best_symbol == NULL) ||
899 (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) <
900 MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]))))
901 {
902 best_symbol = &msymbol[hi];
903 best_objfile = objfile;
904 }
905 }
906 }
907 }
908
909 result.minsym = best_symbol;
910 result.objfile = best_objfile;
911 return result;
912 }
913
914 /* See minsyms.h. */
915
916 struct bound_minimal_symbol
917 lookup_minimal_symbol_by_pc (CORE_ADDR pc)
918 {
919 return lookup_minimal_symbol_by_pc_section (pc, NULL);
920 }
921
922 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
923
924 bool
925 in_gnu_ifunc_stub (CORE_ADDR pc)
926 {
927 bound_minimal_symbol msymbol
928 = lookup_minimal_symbol_by_pc_section (pc, NULL,
929 lookup_msym_prefer::GNU_IFUNC);
930 return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc;
931 }
932
933 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */
934
935 static CORE_ADDR
936 stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
937 {
938 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
939 "the ELF support compiled in."),
940 paddress (gdbarch, pc));
941 }
942
943 /* See elf_gnu_ifunc_resolve_name for its real implementation. */
944
945 static bool
946 stub_gnu_ifunc_resolve_name (const char *function_name,
947 CORE_ADDR *function_address_p)
948 {
949 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
950 "the ELF support compiled in."),
951 function_name);
952 }
953
954 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */
955
956 static void
957 stub_gnu_ifunc_resolver_stop (struct breakpoint *b)
958 {
959 internal_error (__FILE__, __LINE__,
960 _("elf_gnu_ifunc_resolver_stop cannot be reached."));
961 }
962
963 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
964
965 static void
966 stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
967 {
968 internal_error (__FILE__, __LINE__,
969 _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
970 }
971
972 /* See elf_gnu_ifunc_fns for its real implementation. */
973
974 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns =
975 {
976 stub_gnu_ifunc_resolve_addr,
977 stub_gnu_ifunc_resolve_name,
978 stub_gnu_ifunc_resolver_stop,
979 stub_gnu_ifunc_resolver_return_stop,
980 };
981
982 /* A placeholder for &elf_gnu_ifunc_fns. */
983
984 const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns;
985
986 \f
987
988 /* Return leading symbol character for a BFD. If BFD is NULL,
989 return the leading symbol character from the main objfile. */
990
991 static int
992 get_symbol_leading_char (bfd *abfd)
993 {
994 if (abfd != NULL)
995 return bfd_get_symbol_leading_char (abfd);
996 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
997 return bfd_get_symbol_leading_char (symfile_objfile->obfd);
998 return 0;
999 }
1000
1001 /* See minsyms.h. */
1002
1003 minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj)
1004 : m_objfile (obj),
1005 m_msym_bunch (NULL),
1006 /* Note that presetting m_msym_bunch_index to BUNCH_SIZE causes the
1007 first call to save a minimal symbol to allocate the memory for
1008 the first bunch. */
1009 m_msym_bunch_index (BUNCH_SIZE),
1010 m_msym_count (0)
1011 {
1012 }
1013
1014 /* Discard the currently collected minimal symbols, if any. If we wish
1015 to save them for later use, we must have already copied them somewhere
1016 else before calling this function. */
1017
1018 minimal_symbol_reader::~minimal_symbol_reader ()
1019 {
1020 struct msym_bunch *next;
1021
1022 while (m_msym_bunch != NULL)
1023 {
1024 next = m_msym_bunch->next;
1025 xfree (m_msym_bunch);
1026 m_msym_bunch = next;
1027 }
1028 }
1029
1030 /* See minsyms.h. */
1031
1032 void
1033 minimal_symbol_reader::record (const char *name, CORE_ADDR address,
1034 enum minimal_symbol_type ms_type)
1035 {
1036 int section;
1037
1038 switch (ms_type)
1039 {
1040 case mst_text:
1041 case mst_text_gnu_ifunc:
1042 case mst_file_text:
1043 case mst_solib_trampoline:
1044 section = SECT_OFF_TEXT (m_objfile);
1045 break;
1046 case mst_data:
1047 case mst_data_gnu_ifunc:
1048 case mst_file_data:
1049 section = SECT_OFF_DATA (m_objfile);
1050 break;
1051 case mst_bss:
1052 case mst_file_bss:
1053 section = SECT_OFF_BSS (m_objfile);
1054 break;
1055 default:
1056 section = -1;
1057 }
1058
1059 record_with_info (name, address, ms_type, section);
1060 }
1061
1062 /* Convert an enumerator of type minimal_symbol_type to its string
1063 representation. */
1064
1065 static const char *
1066 mst_str (minimal_symbol_type t)
1067 {
1068 #define MST_TO_STR(x) case x: return #x;
1069 switch (t)
1070 {
1071 MST_TO_STR (mst_unknown);
1072 MST_TO_STR (mst_text);
1073 MST_TO_STR (mst_text_gnu_ifunc);
1074 MST_TO_STR (mst_slot_got_plt);
1075 MST_TO_STR (mst_data);
1076 MST_TO_STR (mst_bss);
1077 MST_TO_STR (mst_abs);
1078 MST_TO_STR (mst_solib_trampoline);
1079 MST_TO_STR (mst_file_text);
1080 MST_TO_STR (mst_file_data);
1081 MST_TO_STR (mst_file_bss);
1082
1083 default:
1084 return "mst_???";
1085 }
1086 #undef MST_TO_STR
1087 }
1088
1089 /* See minsyms.h. */
1090
1091 struct minimal_symbol *
1092 minimal_symbol_reader::record_full (gdb::string_view name,
1093 bool copy_name, CORE_ADDR address,
1094 enum minimal_symbol_type ms_type,
1095 int section)
1096 {
1097 struct msym_bunch *newobj;
1098 struct minimal_symbol *msymbol;
1099
1100 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
1101 the minimal symbols, because if there is also another symbol
1102 at the same address (e.g. the first function of the file),
1103 lookup_minimal_symbol_by_pc would have no way of getting the
1104 right one. */
1105 if (ms_type == mst_file_text && name[0] == 'g'
1106 && (name == GCC_COMPILED_FLAG_SYMBOL
1107 || name == GCC2_COMPILED_FLAG_SYMBOL))
1108 return (NULL);
1109
1110 /* It's safe to strip the leading char here once, since the name
1111 is also stored stripped in the minimal symbol table. */
1112 if (name[0] == get_symbol_leading_char (m_objfile->obfd))
1113 name = name.substr (1);
1114
1115 if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
1116 return (NULL);
1117
1118 if (symtab_create_debug >= 2)
1119 printf_unfiltered ("Recording minsym: %-21s %18s %4d %.*s\n",
1120 mst_str (ms_type), hex_string (address), section,
1121 (int) name.size (), name.data ());
1122
1123 if (m_msym_bunch_index == BUNCH_SIZE)
1124 {
1125 newobj = XCNEW (struct msym_bunch);
1126 m_msym_bunch_index = 0;
1127 newobj->next = m_msym_bunch;
1128 m_msym_bunch = newobj;
1129 }
1130 msymbol = &m_msym_bunch->contents[m_msym_bunch_index];
1131 msymbol->set_language (language_auto,
1132 &m_objfile->per_bfd->storage_obstack);
1133
1134 if (copy_name)
1135 msymbol->name = obstack_strndup (&m_objfile->per_bfd->storage_obstack,
1136 name.data (), name.size ());
1137 else
1138 msymbol->name = name.data ();
1139
1140 SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
1141 MSYMBOL_SECTION (msymbol) = section;
1142
1143 MSYMBOL_TYPE (msymbol) = ms_type;
1144
1145 /* If we already read minimal symbols for this objfile, then don't
1146 ever allocate a new one. */
1147 if (!m_objfile->per_bfd->minsyms_read)
1148 {
1149 m_msym_bunch_index++;
1150 m_objfile->per_bfd->n_minsyms++;
1151 }
1152 m_msym_count++;
1153 return msymbol;
1154 }
1155
1156 /* Compare two minimal symbols by address and return true if FN1's address
1157 is less than FN2's, so that we sort into unsigned numeric order.
1158 Within groups with the same address, sort by name. */
1159
1160 static inline bool
1161 minimal_symbol_is_less_than (const minimal_symbol &fn1,
1162 const minimal_symbol &fn2)
1163 {
1164 if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) < MSYMBOL_VALUE_RAW_ADDRESS (&fn2))
1165 {
1166 return true; /* addr 1 is less than addr 2. */
1167 }
1168 else if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) > MSYMBOL_VALUE_RAW_ADDRESS (&fn2))
1169 {
1170 return false; /* addr 1 is greater than addr 2. */
1171 }
1172 else
1173 /* addrs are equal: sort by name */
1174 {
1175 const char *name1 = fn1.linkage_name ();
1176 const char *name2 = fn2.linkage_name ();
1177
1178 if (name1 && name2) /* both have names */
1179 return strcmp (name1, name2) < 0;
1180 else if (name2)
1181 return true; /* fn1 has no name, so it is "less". */
1182 else if (name1) /* fn2 has no name, so it is "less". */
1183 return false;
1184 else
1185 return false; /* Neither has a name, so they're equal. */
1186 }
1187 }
1188
1189 /* Compact duplicate entries out of a minimal symbol table by walking
1190 through the table and compacting out entries with duplicate addresses
1191 and matching names. Return the number of entries remaining.
1192
1193 On entry, the table resides between msymbol[0] and msymbol[mcount].
1194 On exit, it resides between msymbol[0] and msymbol[result_count].
1195
1196 When files contain multiple sources of symbol information, it is
1197 possible for the minimal symbol table to contain many duplicate entries.
1198 As an example, SVR4 systems use ELF formatted object files, which
1199 usually contain at least two different types of symbol tables (a
1200 standard ELF one and a smaller dynamic linking table), as well as
1201 DWARF debugging information for files compiled with -g.
1202
1203 Without compacting, the minimal symbol table for gdb itself contains
1204 over a 1000 duplicates, about a third of the total table size. Aside
1205 from the potential trap of not noticing that two successive entries
1206 identify the same location, this duplication impacts the time required
1207 to linearly scan the table, which is done in a number of places. So we
1208 just do one linear scan here and toss out the duplicates.
1209
1210 Since the different sources of information for each symbol may
1211 have different levels of "completeness", we may have duplicates
1212 that have one entry with type "mst_unknown" and the other with a
1213 known type. So if the one we are leaving alone has type mst_unknown,
1214 overwrite its type with the type from the one we are compacting out. */
1215
1216 static int
1217 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
1218 struct objfile *objfile)
1219 {
1220 struct minimal_symbol *copyfrom;
1221 struct minimal_symbol *copyto;
1222
1223 if (mcount > 0)
1224 {
1225 copyfrom = copyto = msymbol;
1226 while (copyfrom < msymbol + mcount - 1)
1227 {
1228 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
1229 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
1230 && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
1231 && strcmp (copyfrom->linkage_name (),
1232 (copyfrom + 1)->linkage_name ()) == 0)
1233 {
1234 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
1235 {
1236 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
1237 }
1238 copyfrom++;
1239 }
1240 else
1241 *copyto++ = *copyfrom++;
1242 }
1243 *copyto++ = *copyfrom++;
1244 mcount = copyto - msymbol;
1245 }
1246 return (mcount);
1247 }
1248
1249 static void
1250 clear_minimal_symbol_hash_tables (struct objfile *objfile)
1251 {
1252 for (size_t i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
1253 {
1254 objfile->per_bfd->msymbol_hash[i] = 0;
1255 objfile->per_bfd->msymbol_demangled_hash[i] = 0;
1256 }
1257 }
1258
1259 /* This struct is used to store values we compute for msymbols on the
1260 background threads but don't need to keep around long term. */
1261 struct computed_hash_values
1262 {
1263 /* Length of the linkage_name of the symbol. */
1264 size_t name_length;
1265 /* Hash code (using fast_hash) of the linkage_name. */
1266 hashval_t mangled_name_hash;
1267 /* The msymbol_hash of the linkage_name. */
1268 unsigned int minsym_hash;
1269 /* The msymbol_hash of the search_name. */
1270 unsigned int minsym_demangled_hash;
1271 };
1272
1273 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1274 after compacting or sorting the table since the entries move around
1275 thus causing the internal minimal_symbol pointers to become jumbled. */
1276
1277 static void
1278 build_minimal_symbol_hash_tables
1279 (struct objfile *objfile,
1280 const std::vector<computed_hash_values>& hash_values)
1281 {
1282 int i;
1283 struct minimal_symbol *msym;
1284
1285 /* (Re)insert the actual entries. */
1286 int mcount = objfile->per_bfd->minimal_symbol_count;
1287 for ((i = 0,
1288 msym = objfile->per_bfd->msymbols.get ());
1289 i < mcount;
1290 i++, msym++)
1291 {
1292 msym->hash_next = 0;
1293 add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash,
1294 hash_values[i].minsym_hash);
1295
1296 msym->demangled_hash_next = 0;
1297 if (msym->search_name () != msym->linkage_name ())
1298 add_minsym_to_demangled_hash_table
1299 (msym, objfile, hash_values[i].minsym_demangled_hash);
1300 }
1301 }
1302
1303 /* Add the minimal symbols in the existing bunches to the objfile's official
1304 minimal symbol table. In most cases there is no minimal symbol table yet
1305 for this objfile, and the existing bunches are used to create one. Once
1306 in a while (for shared libraries for example), we add symbols (e.g. common
1307 symbols) to an existing objfile. */
1308
1309 void
1310 minimal_symbol_reader::install ()
1311 {
1312 int mcount;
1313 struct msym_bunch *bunch;
1314 struct minimal_symbol *msymbols;
1315 int alloc_count;
1316
1317 if (m_objfile->per_bfd->minsyms_read)
1318 return;
1319
1320 if (m_msym_count > 0)
1321 {
1322 if (symtab_create_debug)
1323 {
1324 fprintf_unfiltered (gdb_stdlog,
1325 "Installing %d minimal symbols of objfile %s.\n",
1326 m_msym_count, objfile_name (m_objfile));
1327 }
1328
1329 /* Allocate enough space, into which we will gather the bunches
1330 of new and existing minimal symbols, sort them, and then
1331 compact out the duplicate entries. Once we have a final
1332 table, we will give back the excess space. */
1333
1334 alloc_count = m_msym_count + m_objfile->per_bfd->minimal_symbol_count;
1335 gdb::unique_xmalloc_ptr<minimal_symbol>
1336 msym_holder (XNEWVEC (minimal_symbol, alloc_count));
1337 msymbols = msym_holder.get ();
1338
1339 /* Copy in the existing minimal symbols, if there are any. */
1340
1341 if (m_objfile->per_bfd->minimal_symbol_count)
1342 memcpy (msymbols, m_objfile->per_bfd->msymbols.get (),
1343 m_objfile->per_bfd->minimal_symbol_count
1344 * sizeof (struct minimal_symbol));
1345
1346 /* Walk through the list of minimal symbol bunches, adding each symbol
1347 to the new contiguous array of symbols. Note that we start with the
1348 current, possibly partially filled bunch (thus we use the current
1349 msym_bunch_index for the first bunch we copy over), and thereafter
1350 each bunch is full. */
1351
1352 mcount = m_objfile->per_bfd->minimal_symbol_count;
1353
1354 for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next)
1355 {
1356 memcpy (&msymbols[mcount], &bunch->contents[0],
1357 m_msym_bunch_index * sizeof (struct minimal_symbol));
1358 mcount += m_msym_bunch_index;
1359 m_msym_bunch_index = BUNCH_SIZE;
1360 }
1361
1362 /* Sort the minimal symbols by address. */
1363
1364 std::sort (msymbols, msymbols + mcount, minimal_symbol_is_less_than);
1365
1366 /* Compact out any duplicates, and free up whatever space we are
1367 no longer using. */
1368
1369 mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
1370 msym_holder.reset (XRESIZEVEC (struct minimal_symbol,
1371 msym_holder.release (),
1372 mcount));
1373
1374 /* Attach the minimal symbol table to the specified objfile.
1375 The strings themselves are also located in the storage_obstack
1376 of this objfile. */
1377
1378 if (m_objfile->per_bfd->minimal_symbol_count != 0)
1379 clear_minimal_symbol_hash_tables (m_objfile);
1380
1381 m_objfile->per_bfd->minimal_symbol_count = mcount;
1382 m_objfile->per_bfd->msymbols = std::move (msym_holder);
1383
1384 #if CXX_STD_THREAD
1385 /* Mutex that is used when modifying or accessing the demangled
1386 hash table. */
1387 std::mutex demangled_mutex;
1388 #endif
1389
1390 std::vector<computed_hash_values> hash_values (mcount);
1391
1392 msymbols = m_objfile->per_bfd->msymbols.get ();
1393 gdb::parallel_for_each
1394 (&msymbols[0], &msymbols[mcount],
1395 [&] (minimal_symbol *start, minimal_symbol *end)
1396 {
1397 for (minimal_symbol *msym = start; msym < end; ++msym)
1398 {
1399 size_t idx = msym - msymbols;
1400 hash_values[idx].name_length = strlen (msym->name);
1401 if (!msym->name_set)
1402 {
1403 /* This will be freed later, by symbol_set_names. */
1404 char *demangled_name
1405 = symbol_find_demangled_name (msym, msym->name);
1406 symbol_set_demangled_name
1407 (msym, demangled_name,
1408 &m_objfile->per_bfd->storage_obstack);
1409 msym->name_set = 1;
1410 }
1411 /* This mangled_name_hash computation has to be outside of
1412 the name_set check, or symbol_set_names below will
1413 be called with an invalid hash value. */
1414 hash_values[idx].mangled_name_hash
1415 = fast_hash (msym->name, hash_values[idx].name_length);
1416 hash_values[idx].minsym_hash
1417 = msymbol_hash (msym->linkage_name ());
1418 /* We only use this hash code if the search name differs
1419 from the linkage name. See the code in
1420 build_minimal_symbol_hash_tables. */
1421 if (msym->search_name () != msym->linkage_name ())
1422 hash_values[idx].minsym_demangled_hash
1423 = search_name_hash (msym->language (), msym->search_name ());
1424 }
1425 {
1426 /* To limit how long we hold the lock, we only acquire it here
1427 and not while we demangle the names above. */
1428 #if CXX_STD_THREAD
1429 std::lock_guard<std::mutex> guard (demangled_mutex);
1430 #endif
1431 for (minimal_symbol *msym = start; msym < end; ++msym)
1432 {
1433 size_t idx = msym - msymbols;
1434 symbol_set_names
1435 (msym,
1436 gdb::string_view(msym->name,
1437 hash_values[idx].name_length),
1438 false,
1439 m_objfile->per_bfd,
1440 hash_values[idx].mangled_name_hash);
1441 }
1442 }
1443 });
1444
1445 build_minimal_symbol_hash_tables (m_objfile, hash_values);
1446 }
1447 }
1448
1449 /* Check if PC is in a shared library trampoline code stub.
1450 Return minimal symbol for the trampoline entry or NULL if PC is not
1451 in a trampoline code stub. */
1452
1453 static struct minimal_symbol *
1454 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
1455 {
1456 bound_minimal_symbol msymbol
1457 = lookup_minimal_symbol_by_pc_section (pc, NULL,
1458 lookup_msym_prefer::TRAMPOLINE);
1459
1460 if (msymbol.minsym != NULL
1461 && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
1462 return msymbol.minsym;
1463 return NULL;
1464 }
1465
1466 /* If PC is in a shared library trampoline code stub, return the
1467 address of the `real' function belonging to the stub.
1468 Return 0 if PC is not in a trampoline code stub or if the real
1469 function is not found in the minimal symbol table.
1470
1471 We may fail to find the right function if a function with the
1472 same name is defined in more than one shared library, but this
1473 is considered bad programming style. We could return 0 if we find
1474 a duplicate function in case this matters someday. */
1475
1476 CORE_ADDR
1477 find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
1478 {
1479 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1480
1481 if (tsymbol != NULL)
1482 {
1483 for (objfile *objfile : current_program_space->objfiles ())
1484 {
1485 for (minimal_symbol *msymbol : objfile->msymbols ())
1486 {
1487 /* Also handle minimal symbols pointing to function
1488 descriptors. */
1489 if ((MSYMBOL_TYPE (msymbol) == mst_text
1490 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
1491 || MSYMBOL_TYPE (msymbol) == mst_data
1492 || MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc)
1493 && strcmp (msymbol->linkage_name (),
1494 tsymbol->linkage_name ()) == 0)
1495 {
1496 CORE_ADDR func;
1497
1498 /* Ignore data symbols that are not function
1499 descriptors. */
1500 if (msymbol_is_function (objfile, msymbol, &func))
1501 return func;
1502 }
1503 }
1504 }
1505 }
1506 return 0;
1507 }
1508
1509 /* See minsyms.h. */
1510
1511 CORE_ADDR
1512 minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
1513 {
1514 short section;
1515 struct obj_section *obj_section;
1516 CORE_ADDR result;
1517 struct minimal_symbol *iter, *msymbol;
1518
1519 gdb_assert (minsym.minsym != NULL);
1520
1521 /* If the minimal symbol has a size, use it. Otherwise use the
1522 lesser of the next minimal symbol in the same section, or the end
1523 of the section, as the end of the function. */
1524
1525 if (MSYMBOL_SIZE (minsym.minsym) != 0)
1526 return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
1527
1528 /* Step over other symbols at this same address, and symbols in
1529 other sections, to find the next symbol in this section with a
1530 different address. */
1531
1532 struct minimal_symbol *past_the_end
1533 = (minsym.objfile->per_bfd->msymbols.get ()
1534 + minsym.objfile->per_bfd->minimal_symbol_count);
1535 msymbol = minsym.minsym;
1536 section = MSYMBOL_SECTION (msymbol);
1537 for (iter = msymbol + 1; iter != past_the_end; ++iter)
1538 {
1539 if ((MSYMBOL_VALUE_RAW_ADDRESS (iter)
1540 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
1541 && MSYMBOL_SECTION (iter) == section)
1542 break;
1543 }
1544
1545 obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
1546 if (iter != past_the_end
1547 && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter)
1548 < obj_section_endaddr (obj_section)))
1549 result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter);
1550 else
1551 /* We got the start address from the last msymbol in the objfile.
1552 So the end address is the end of the section. */
1553 result = obj_section_endaddr (obj_section);
1554
1555 return result;
1556 }
This page took 0.061268 seconds and 4 git commands to generate.