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[deliverable/binutils-gdb.git] / gdb / minsyms.c
CommitLineData
c906108c 1/* GDB routines for manipulating the minimal symbol tables.
42a4f53d 2 Copyright (C) 1992-2019 Free Software Foundation, Inc.
c906108c
SS
3 Contributed by Cygnus Support, using pieces from other GDB modules.
4
c5aa993b 5 This file is part of GDB.
c906108c 6
c5aa993b
JM
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
a9762ec7 9 the Free Software Foundation; either version 3 of the License, or
c5aa993b 10 (at your option) any later version.
c906108c 11
c5aa993b
JM
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.
c906108c 16
c5aa993b 17 You should have received a copy of the GNU General Public License
a9762ec7 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
c906108c
SS
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.
c5aa993b 32
c906108c
SS
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
025bb325 36 to figure out what full symbol table entries need to be read in. */
c906108c
SS
37
38
39#include "defs.h"
9227b5eb 40#include <ctype.h>
c906108c
SS
41#include "symtab.h"
42#include "bfd.h"
0ba1096a 43#include "filenames.h"
c906108c
SS
44#include "symfile.h"
45#include "objfiles.h"
46#include "demangle.h"
7ed49443
JB
47#include "value.h"
48#include "cp-abi.h"
42848c96 49#include "target.h"
71c25dea
TT
50#include "cp-support.h"
51#include "language.h"
529480d0 52#include "cli/cli-utils.h"
0747795c 53#include "common/symbol.h"
b5ec771e 54#include <algorithm>
deeeba55 55#include "safe-ctype.h"
c906108c 56
bf223d3e
PA
57/* See minsyms.h. */
58
59bool
4024cf2b
PA
60msymbol_is_function (struct objfile *objfile, minimal_symbol *minsym,
61 CORE_ADDR *func_address_p)
bf223d3e 62{
4024cf2b
PA
63 CORE_ADDR msym_addr = MSYMBOL_VALUE_ADDRESS (objfile, minsym);
64
65 switch (minsym->type)
bf223d3e 66 {
4024cf2b
PA
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:
f50776aa 73 case mst_data_gnu_ifunc:
4024cf2b
PA
74 {
75 struct gdbarch *gdbarch = get_objfile_arch (objfile);
8b88a78e
PA
76 CORE_ADDR pc
77 = gdbarch_convert_from_func_ptr_addr (gdbarch, msym_addr,
78 current_top_target ());
4024cf2b
PA
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 }
bf223d3e 87 default:
4024cf2b
PA
88 if (func_address_p != NULL)
89 *func_address_p = msym_addr;
90 return true;
bf223d3e
PA
91 }
92}
93
c906108c 94/* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
79e7ae11 95 At the end, copy them all into one newly allocated array. */
c906108c
SS
96
97#define BUNCH_SIZE 127
98
99struct msym_bunch
c5aa993b
JM
100 {
101 struct msym_bunch *next;
102 struct minimal_symbol contents[BUNCH_SIZE];
103 };
c906108c 104
b19686e0 105/* See minsyms.h. */
9227b5eb
JB
106
107unsigned int
108msymbol_hash_iw (const char *string)
109{
110 unsigned int hash = 0;
b8d56208 111
9227b5eb
JB
112 while (*string && *string != '(')
113 {
f1735a53 114 string = skip_spaces (string);
9227b5eb 115 if (*string && *string != '(')
375f3d86 116 {
59d7bcaf 117 hash = SYMBOL_HASH_NEXT (hash, *string);
375f3d86
DJ
118 ++string;
119 }
9227b5eb 120 }
261397f8 121 return hash;
9227b5eb
JB
122}
123
b19686e0 124/* See minsyms.h. */
9227b5eb
JB
125
126unsigned int
127msymbol_hash (const char *string)
128{
129 unsigned int hash = 0;
b8d56208 130
9227b5eb 131 for (; *string; ++string)
59d7bcaf 132 hash = SYMBOL_HASH_NEXT (hash, *string);
261397f8 133 return hash;
9227b5eb
JB
134}
135
136/* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
984ac464 137static void
9227b5eb
JB
138add_minsym_to_hash_table (struct minimal_symbol *sym,
139 struct minimal_symbol **table)
140{
141 if (sym->hash_next == NULL)
142 {
f56f77c1 143 unsigned int hash
efd66ac6 144 = msymbol_hash (MSYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
b8d56208 145
9227b5eb
JB
146 sym->hash_next = table[hash];
147 table[hash] = sym;
148 }
149}
150
0729fd50
DB
151/* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
152 TABLE. */
153static void
154add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
b5ec771e 155 struct objfile *objfile)
0729fd50
DB
156{
157 if (sym->demangled_hash_next == NULL)
158 {
b5ec771e
PA
159 unsigned int hash = search_name_hash (MSYMBOL_LANGUAGE (sym),
160 MSYMBOL_SEARCH_NAME (sym));
161
1b7a07cb 162 objfile->per_bfd->demangled_hash_languages.set (MSYMBOL_LANGUAGE (sym));
b5ec771e
PA
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}
b8d56208 171
b5ec771e
PA
172/* Worker object for lookup_minimal_symbol. Stores temporary results
173 while walking the symbol tables. */
174
175struct 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
196bool
197found_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
242static void
243lookup_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
266static void
267lookup_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;
0729fd50
DB
284 }
285}
286
c906108c
SS
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
72a5efb3
DJ
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
c906108c
SS
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
d73f140a
JB
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. */
c906108c 306
3b7344d5
TT
307struct bound_minimal_symbol
308lookup_minimal_symbol (const char *name, const char *sfile,
309 struct objfile *objf)
c906108c
SS
310{
311 struct objfile *objfile;
b5ec771e 312 found_minimal_symbols found;
c906108c 313
b5ec771e 314 unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
9227b5eb 315
b5ec771e
PA
316 auto *mangled_cmp
317 = (case_sensitivity == case_sensitive_on
318 ? strcmp
319 : strcasecmp);
71c25dea 320
c906108c 321 if (sfile != NULL)
9f37bbcc 322 sfile = lbasename (sfile);
c906108c 323
b5ec771e 324 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
71c25dea 325
c906108c 326 for (objfile = object_files;
b5ec771e 327 objfile != NULL && found.external_symbol.minsym == NULL;
c5aa993b 328 objfile = objfile->next)
c906108c 329 {
56e3f43c 330 if (objf == NULL || objf == objfile
15d123c9 331 || objf == objfile->separate_debug_objfile_backlink)
c906108c 332 {
b5ec771e
PA
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
9227b5eb
JB
341 /* Do two passes: the first over the ordinary hash table,
342 and the second over the demangled hash table. */
b5ec771e
PA
343 lookup_minimal_symbol_mangled (name, sfile, objfile,
344 objfile->per_bfd->msymbol_hash,
345 mangled_hash, mangled_cmp, found);
cc485e62 346
b5ec771e
PA
347 /* If not found, try the demangled hash table. */
348 if (found.external_symbol.minsym == NULL)
c906108c 349 {
b5ec771e
PA
350 /* Once for each language in the demangled hash names
351 table (usually just zero or one languages). */
1b7a07cb 352 for (unsigned iter = 0; iter < nr_languages; ++iter)
c906108c 353 {
1b7a07cb
TT
354 if (!objfile->per_bfd->demangled_hash_languages.test (iter))
355 continue;
356 enum language lang = (enum language) iter;
357
b5ec771e
PA
358 unsigned int hash
359 = (lookup_name.search_name_hash (lang)
360 % MINIMAL_SYMBOL_HASH_SIZE);
361
362 symbol_name_matcher_ftype *match
618daa93
PA
363 = get_symbol_name_matcher (language_def (lang),
364 lookup_name);
b5ec771e
PA
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;
9227b5eb 374 }
c906108c
SS
375 }
376 }
377 }
71c25dea 378
c906108c 379 /* External symbols are best. */
b5ec771e 380 if (found.external_symbol.minsym != NULL)
cc485e62
DE
381 {
382 if (symbol_lookup_debug)
383 {
b5ec771e
PA
384 minimal_symbol *minsym = found.external_symbol.minsym;
385
cc485e62 386 fprintf_unfiltered (gdb_stdlog,
b5ec771e
PA
387 "lookup_minimal_symbol (...) = %s (external)\n",
388 host_address_to_string (minsym));
cc485e62 389 }
b5ec771e 390 return found.external_symbol;
cc485e62 391 }
c906108c
SS
392
393 /* File-local symbols are next best. */
b5ec771e 394 if (found.file_symbol.minsym != NULL)
cc485e62
DE
395 {
396 if (symbol_lookup_debug)
397 {
b5ec771e
PA
398 minimal_symbol *minsym = found.file_symbol.minsym;
399
cc485e62 400 fprintf_unfiltered (gdb_stdlog,
b5ec771e
PA
401 "lookup_minimal_symbol (...) = %s (file-local)\n",
402 host_address_to_string (minsym));
cc485e62 403 }
b5ec771e 404 return found.file_symbol;
cc485e62 405 }
c906108c
SS
406
407 /* Symbols for shared library trampolines are next best. */
b5ec771e 408 if (found.trampoline_symbol.minsym != NULL)
cc485e62 409 {
b5ec771e
PA
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;
cc485e62 420 }
b5ec771e
PA
421
422 /* Not found. */
423 if (symbol_lookup_debug)
424 fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
425 return {};
7c7b6655
TT
426}
427
428/* See minsyms.h. */
c906108c 429
7c7b6655
TT
430struct bound_minimal_symbol
431lookup_bound_minimal_symbol (const char *name)
432{
3b7344d5 433 return lookup_minimal_symbol (name, NULL, NULL);
c906108c
SS
434}
435
bd9269f7
GB
436/* See common/symbol.h. */
437
438int
439find_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
8825213e
PA
451/* Get the lookup name form best suitable for linkage name
452 matching. */
453
454static const char *
455linkage_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
b19686e0 470/* See minsyms.h. */
f8eba3c6
TT
471
472void
41c1efc6
TT
473iterate_over_minimal_symbols
474 (struct objfile *objf, const lookup_name_info &lookup_name,
ca31ab1d 475 gdb::function_view<bool (struct minimal_symbol *)> callback)
f8eba3c6 476{
f8eba3c6 477 /* The first pass is over the ordinary hash table. */
f8eba3c6 478 {
8825213e 479 const char *name = linkage_name_str (lookup_name);
b5ec771e
PA
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)
ca31ab1d
PA
491 if (callback (iter))
492 return;
b5ec771e 493 }
f8eba3c6
TT
494 }
495
b5ec771e
PA
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). */
1b7a07cb 499 for (unsigned liter = 0; liter < nr_languages; ++liter)
f8eba3c6 500 {
1b7a07cb
TT
501 if (!objf->per_bfd->demangled_hash_languages.test (liter))
502 continue;
503
504 enum language lang = (enum language) liter;
b5ec771e
PA
505 const language_defn *lang_def = language_def (lang);
506 symbol_name_matcher_ftype *name_match
618daa93 507 = get_symbol_name_matcher (lang_def, lookup_name);
b5ec771e
PA
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))
ca31ab1d
PA
515 if (callback (iter))
516 return;
f8eba3c6
TT
517 }
518}
519
b19686e0 520/* See minsyms.h. */
c5aa993b 521
3b7344d5 522struct bound_minimal_symbol
5520a790 523lookup_minimal_symbol_text (const char *name, struct objfile *objf)
c906108c
SS
524{
525 struct objfile *objfile;
526 struct minimal_symbol *msymbol;
3b7344d5
TT
527 struct bound_minimal_symbol found_symbol = { NULL, NULL };
528 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
c906108c 529
72a5efb3
DJ
530 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
531
c906108c 532 for (objfile = object_files;
3b7344d5 533 objfile != NULL && found_symbol.minsym == NULL;
c5aa993b 534 objfile = objfile->next)
c906108c 535 {
56e3f43c 536 if (objf == NULL || objf == objfile
15d123c9 537 || objf == objfile->separate_debug_objfile_backlink)
c906108c 538 {
34643a32 539 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
3b7344d5 540 msymbol != NULL && found_symbol.minsym == NULL;
72a5efb3 541 msymbol = msymbol->hash_next)
c906108c 542 {
efd66ac6 543 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
0875794a
JK
544 (MSYMBOL_TYPE (msymbol) == mst_text
545 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
546 || MSYMBOL_TYPE (msymbol) == mst_file_text))
c906108c
SS
547 {
548 switch (MSYMBOL_TYPE (msymbol))
549 {
550 case mst_file_text:
3b7344d5
TT
551 found_file_symbol.minsym = msymbol;
552 found_file_symbol.objfile = objfile;
c906108c
SS
553 break;
554 default:
3b7344d5
TT
555 found_symbol.minsym = msymbol;
556 found_symbol.objfile = objfile;
c906108c
SS
557 break;
558 }
559 }
560 }
561 }
562 }
563 /* External symbols are best. */
3b7344d5 564 if (found_symbol.minsym)
c906108c
SS
565 return found_symbol;
566
567 /* File-local symbols are next best. */
3b7344d5 568 return found_file_symbol;
c906108c
SS
569}
570
b19686e0 571/* See minsyms.h. */
907fc202
UW
572
573struct minimal_symbol *
574lookup_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
15d123c9 587 || objf == objfile->separate_debug_objfile_backlink)
907fc202 588 {
34643a32 589 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
907fc202
UW
590 msymbol != NULL;
591 msymbol = msymbol->hash_next)
592 {
77e371c0 593 if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
efd66ac6 594 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0)
907fc202
UW
595 return msymbol;
596 }
597 }
598 }
599
600 return NULL;
601}
602
b19686e0 603/* See minsyms.h. */
c5aa993b 604
3b7344d5 605struct bound_minimal_symbol
aa1ee363 606lookup_minimal_symbol_solib_trampoline (const char *name,
aa1ee363 607 struct objfile *objf)
c906108c
SS
608{
609 struct objfile *objfile;
610 struct minimal_symbol *msymbol;
3b7344d5 611 struct bound_minimal_symbol found_symbol = { NULL, NULL };
c906108c 612
72a5efb3
DJ
613 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
614
c906108c 615 for (objfile = object_files;
3b7344d5 616 objfile != NULL;
c5aa993b 617 objfile = objfile->next)
c906108c 618 {
56e3f43c 619 if (objf == NULL || objf == objfile
15d123c9 620 || objf == objfile->separate_debug_objfile_backlink)
c906108c 621 {
34643a32 622 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
3b7344d5 623 msymbol != NULL;
72a5efb3 624 msymbol = msymbol->hash_next)
c906108c 625 {
efd66ac6 626 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
c906108c 627 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
3b7344d5
TT
628 {
629 found_symbol.objfile = objfile;
630 found_symbol.minsym = msymbol;
631 return found_symbol;
632 }
c906108c
SS
633 }
634 }
635 }
636
3b7344d5 637 return found_symbol;
c906108c
SS
638}
639
77e371c0
TT
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
645static int
646frob_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
6ae50267
PA
662/* Helper for lookup_minimal_symbol_by_pc_section. Convert a
663 lookup_msym_prefer to a minimal_symbol_type. */
664
665static minimal_symbol_type
666msym_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
c906108c
SS
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
00878c6e
PP
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.
c906108c 693
2eaf8d2a
DJ
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
20944a6e
PA
698bound_minimal_symbol
699lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section,
700 lookup_msym_prefer prefer)
c906108c
SS
701{
702 int lo;
703 int hi;
fe978cb0 704 int newobj;
c906108c
SS
705 struct objfile *objfile;
706 struct minimal_symbol *msymbol;
707 struct minimal_symbol *best_symbol = NULL;
7cbd4a93
TT
708 struct objfile *best_objfile = NULL;
709 struct bound_minimal_symbol result;
c906108c 710
20944a6e
PA
711 if (section == NULL)
712 {
713 section = find_pc_section (pc_in);
714 if (section == NULL)
715 return {};
716 }
717
6ae50267 718 minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer);
00878c6e
PP
719
720 /* We can not require the symbol found to be in section, because
96225718
DJ
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
00878c6e 729 gdb_assert (section != NULL);
96225718 730
15d123c9
TG
731 for (objfile = section->objfile;
732 objfile != NULL;
733 objfile = objfile_separate_debug_iterate (section->objfile, objfile))
c906108c 734 {
77e371c0
TT
735 CORE_ADDR pc = pc_in;
736
741d7538
TT
737 /* If this objfile has a minimal symbol table, go search it
738 using a binary search. */
c906108c 739
34643a32 740 if (objfile->per_bfd->minimal_symbol_count > 0)
c906108c 741 {
29e8a844
DJ
742 int best_zero_sized = -1;
743
042d75e4 744 msymbol = objfile->per_bfd->msymbols.get ();
c906108c 745 lo = 0;
34643a32 746 hi = objfile->per_bfd->minimal_symbol_count - 1;
c906108c
SS
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
025bb325 764 Warning: this code is trickier than it would appear at first. */
c906108c 765
77e371c0
TT
766 if (frob_address (objfile, &pc)
767 && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo]))
c906108c 768 {
77e371c0 769 while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc)
c906108c 770 {
025bb325
MS
771 /* pc is still strictly less than highest address. */
772 /* Note "new" will always be >= lo. */
fe978cb0
PA
773 newobj = (lo + hi) / 2;
774 if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc)
775 || (lo == newobj))
c906108c 776 {
fe978cb0 777 hi = newobj;
c906108c
SS
778 }
779 else
780 {
fe978cb0 781 lo = newobj;
c906108c
SS
782 }
783 }
784
785 /* If we have multiple symbols at the same address, we want
c5aa993b
JM
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. */
34643a32 788 while (hi < objfile->per_bfd->minimal_symbol_count - 1
77e371c0
TT
789 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
790 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1])))
c906108c
SS
791 hi++;
792
29e8a844
DJ
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
712f90be 808 if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs)
29e8a844
DJ
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. */
efd66ac6 820 && MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]) != NULL
714835d5 821 && (!matching_obj_sections
efd66ac6 822 (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]),
e27d198c 823 section)))
29e8a844
DJ
824 {
825 hi--;
826 continue;
827 }
828
2eaf8d2a
DJ
829 /* If we are looking for a trampoline and this is a
830 text symbol, or the other way around, check the
177b42fe 831 preceding symbol too. If they are otherwise
2eaf8d2a
DJ
832 identical prefer that one. */
833 if (hi > 0
20944a6e 834 && MSYMBOL_TYPE (&msymbol[hi]) != want_type
2eaf8d2a
DJ
835 && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type
836 && (MSYMBOL_SIZE (&msymbol[hi])
837 == MSYMBOL_SIZE (&msymbol[hi - 1]))
77e371c0
TT
838 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
839 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]))
efd66ac6
TT
840 && (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi])
841 == MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi - 1])))
2eaf8d2a
DJ
842 {
843 hi--;
844 continue;
845 }
846
29e8a844
DJ
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. */
5506f9f6 853 if (MSYMBOL_SIZE (&msymbol[hi]) == 0)
29e8a844 854 {
5506f9f6
KB
855 if (best_zero_sized == -1)
856 best_zero_sized = hi;
29e8a844
DJ
857 hi--;
858 continue;
859 }
860
f7a6bb70
DJ
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
77e371c0 868 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
f7a6bb70 869 + MSYMBOL_SIZE (&msymbol[hi]))
77e371c0 870 && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])
f7a6bb70
DJ
871 + MSYMBOL_SIZE (&msymbol[hi - 1])))
872 {
873 hi--;
874 continue;
875 }
876
29e8a844
DJ
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
77e371c0 900 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
29e8a844
DJ
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
c906108c 910 /* The minimal symbol indexed by hi now is the best one in this
c5aa993b 911 objfile's minimal symbol table. See if it is the best one
025bb325 912 overall. */
c906108c 913
c906108c
SS
914 if (hi >= 0
915 && ((best_symbol == NULL) ||
77e371c0
TT
916 (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) <
917 MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]))))
c906108c
SS
918 {
919 best_symbol = &msymbol[hi];
7cbd4a93 920 best_objfile = objfile;
c906108c
SS
921 }
922 }
923 }
924 }
7cbd4a93
TT
925
926 result.minsym = best_symbol;
927 result.objfile = best_objfile;
928 return result;
c906108c
SS
929}
930
b19686e0 931/* See minsyms.h. */
c906108c 932
7cbd4a93 933struct bound_minimal_symbol
fba45db2 934lookup_minimal_symbol_by_pc (CORE_ADDR pc)
c906108c 935{
20944a6e 936 return lookup_minimal_symbol_by_pc_section (pc, NULL);
c906108c 937}
0d5392b8 938
0875794a
JK
939/* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
940
941int
942in_gnu_ifunc_stub (CORE_ADDR pc)
943{
20944a6e
PA
944 bound_minimal_symbol msymbol
945 = lookup_minimal_symbol_by_pc_section (pc, NULL,
946 lookup_msym_prefer::GNU_IFUNC);
7cbd4a93 947 return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc;
0875794a
JK
948}
949
07be84bf
JK
950/* See elf_gnu_ifunc_resolve_addr for its real implementation. */
951
952static CORE_ADDR
953stub_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
962static int
963stub_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
0e30163f
JK
971/* See elf_gnu_ifunc_resolver_stop for its real implementation. */
972
973static void
974stub_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
982static void
983stub_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
07be84bf
JK
989/* See elf_gnu_ifunc_fns for its real implementation. */
990
991static const struct gnu_ifunc_fns stub_gnu_ifunc_fns =
992{
993 stub_gnu_ifunc_resolve_addr,
994 stub_gnu_ifunc_resolve_name,
0e30163f
JK
995 stub_gnu_ifunc_resolver_stop,
996 stub_gnu_ifunc_resolver_return_stop,
07be84bf
JK
997};
998
999/* A placeholder for &elf_gnu_ifunc_fns. */
1000
1001const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns;
1002
c906108c 1003\f
c5aa993b 1004
025bb325 1005/* Return leading symbol character for a BFD. If BFD is NULL,
c906108c
SS
1006 return the leading symbol character from the main objfile. */
1007
c906108c 1008static int
fba45db2 1009get_symbol_leading_char (bfd *abfd)
c906108c
SS
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
b19686e0 1018/* See minsyms.h. */
c906108c 1019
d25e8719 1020minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj)
8dddcb8f
TT
1021: m_objfile (obj),
1022 m_msym_bunch (NULL),
1023 /* Note that presetting m_msym_bunch_index to BUNCH_SIZE causes the
b19686e0
TT
1024 first call to save a minimal symbol to allocate the memory for
1025 the first bunch. */
8dddcb8f
TT
1026 m_msym_bunch_index (BUNCH_SIZE),
1027 m_msym_count (0)
1028{
c906108c
SS
1029}
1030
873a915e
TT
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
79e7ae11 1033 else before calling this function. */
873a915e
TT
1034
1035minimal_symbol_reader::~minimal_symbol_reader ()
1036{
1037 struct msym_bunch *next;
1038
8dddcb8f 1039 while (m_msym_bunch != NULL)
873a915e 1040 {
8dddcb8f
TT
1041 next = m_msym_bunch->next;
1042 xfree (m_msym_bunch);
1043 m_msym_bunch = next;
873a915e
TT
1044 }
1045}
1046
b19686e0
TT
1047/* See minsyms.h. */
1048
c906108c 1049void
8dddcb8f 1050minimal_symbol_reader::record (const char *name, CORE_ADDR address,
ce6c454e 1051 enum minimal_symbol_type ms_type)
c906108c
SS
1052{
1053 int section;
1054
1055 switch (ms_type)
1056 {
1057 case mst_text:
0875794a 1058 case mst_text_gnu_ifunc:
c906108c
SS
1059 case mst_file_text:
1060 case mst_solib_trampoline:
8dddcb8f 1061 section = SECT_OFF_TEXT (m_objfile);
c906108c
SS
1062 break;
1063 case mst_data:
f50776aa 1064 case mst_data_gnu_ifunc:
c906108c 1065 case mst_file_data:
8dddcb8f 1066 section = SECT_OFF_DATA (m_objfile);
c906108c
SS
1067 break;
1068 case mst_bss:
1069 case mst_file_bss:
8dddcb8f 1070 section = SECT_OFF_BSS (m_objfile);
c906108c
SS
1071 break;
1072 default:
1073 section = -1;
1074 }
1075
8dddcb8f 1076 record_with_info (name, address, ms_type, section);
c906108c
SS
1077}
1078
e08b849e
SM
1079/* Convert an enumerator of type minimal_symbol_type to its string
1080 representation. */
1081
1082static const char *
1083mst_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
b19686e0 1106/* See minsyms.h. */
c906108c
SS
1107
1108struct minimal_symbol *
8dddcb8f 1109minimal_symbol_reader::record_full (const char *name, int name_len,
ce6c454e
TT
1110 bool copy_name, CORE_ADDR address,
1111 enum minimal_symbol_type ms_type,
1112 int section)
c906108c 1113{
fe978cb0 1114 struct msym_bunch *newobj;
52f0bd74 1115 struct minimal_symbol *msymbol;
c906108c 1116
66337bb1
CV
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
025bb325 1128 is also stored stripped in the minimal symbol table. */
8dddcb8f 1129 if (name[0] == get_symbol_leading_char (m_objfile->obfd))
04a679b8
TT
1130 {
1131 ++name;
1132 --name_len;
1133 }
66337bb1 1134
61012eef 1135 if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
66337bb1 1136 return (NULL);
c906108c 1137
e08b849e
SM
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
8dddcb8f 1142 if (m_msym_bunch_index == BUNCH_SIZE)
c906108c 1143 {
fe978cb0 1144 newobj = XCNEW (struct msym_bunch);
8dddcb8f
TT
1145 m_msym_bunch_index = 0;
1146 newobj->next = m_msym_bunch;
1147 m_msym_bunch = newobj;
c906108c 1148 }
8dddcb8f 1149 msymbol = &m_msym_bunch->contents[m_msym_bunch_index];
eefba3da
TT
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);
2de7ced7 1153
40c1a007 1154 SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
efd66ac6 1155 MSYMBOL_SECTION (msymbol) = section;
714835d5 1156
c906108c 1157 MSYMBOL_TYPE (msymbol) = ms_type;
9227b5eb 1158
34643a32
TT
1159 /* If we already read minimal symbols for this objfile, then don't
1160 ever allocate a new one. */
8dddcb8f 1161 if (!m_objfile->per_bfd->minsyms_read)
5f6cac40 1162 {
8dddcb8f
TT
1163 m_msym_bunch_index++;
1164 m_objfile->per_bfd->n_minsyms++;
5f6cac40 1165 }
8dddcb8f 1166 m_msym_count++;
c906108c
SS
1167 return msymbol;
1168}
1169
1170/* Compare two minimal symbols by address and return a signed result based
025bb325 1171 on unsigned comparisons, so that we sort into unsigned numeric order.
c906108c
SS
1172 Within groups with the same address, sort by name. */
1173
1174static int
12b9c64f 1175compare_minimal_symbols (const void *fn1p, const void *fn2p)
c906108c 1176{
52f0bd74
AC
1177 const struct minimal_symbol *fn1;
1178 const struct minimal_symbol *fn2;
c906108c
SS
1179
1180 fn1 = (const struct minimal_symbol *) fn1p;
1181 fn2 = (const struct minimal_symbol *) fn2p;
1182
77e371c0 1183 if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) < MSYMBOL_VALUE_RAW_ADDRESS (fn2))
c906108c 1184 {
025bb325 1185 return (-1); /* addr 1 is less than addr 2. */
c906108c 1186 }
77e371c0 1187 else if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) > MSYMBOL_VALUE_RAW_ADDRESS (fn2))
c906108c 1188 {
025bb325 1189 return (1); /* addr 1 is greater than addr 2. */
c906108c 1190 }
c5aa993b
JM
1191 else
1192 /* addrs are equal: sort by name */
c906108c 1193 {
efd66ac6
TT
1194 const char *name1 = MSYMBOL_LINKAGE_NAME (fn1);
1195 const char *name2 = MSYMBOL_LINKAGE_NAME (fn2);
c906108c
SS
1196
1197 if (name1 && name2) /* both have names */
1198 return strcmp (name1, name2);
1199 else if (name2)
025bb325
MS
1200 return 1; /* fn1 has no name, so it is "less". */
1201 else if (name1) /* fn2 has no name, so it is "less". */
c906108c
SS
1202 return -1;
1203 else
025bb325 1204 return (0); /* Neither has a name, so they're equal. */
c906108c
SS
1205 }
1206}
1207
c906108c
SS
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
c906108c
SS
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
1235static int
fba45db2
KB
1236compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
1237 struct objfile *objfile)
c906108c
SS
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 {
77e371c0
TT
1247 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
1248 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
1249 && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
efd66ac6
TT
1250 && strcmp (MSYMBOL_LINKAGE_NAME (copyfrom),
1251 MSYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0)
c906108c 1252 {
c5aa993b 1253 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
c906108c
SS
1254 {
1255 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
1256 }
1257 copyfrom++;
1258 }
1259 else
afbb8d7a 1260 *copyto++ = *copyfrom++;
c906108c
SS
1261 }
1262 *copyto++ = *copyfrom++;
1263 mcount = copyto - msymbol;
1264 }
1265 return (mcount);
1266}
1267
afbb8d7a
KB
1268/* Build (or rebuild) the minimal symbol hash tables. This is necessary
1269 after compacting or sorting the table since the entries move around
025bb325 1270 thus causing the internal minimal_symbol pointers to become jumbled. */
afbb8d7a
KB
1271
1272static void
1273build_minimal_symbol_hash_tables (struct objfile *objfile)
1274{
1275 int i;
1276 struct minimal_symbol *msym;
1277
025bb325 1278 /* Clear the hash tables. */
afbb8d7a
KB
1279 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
1280 {
34643a32
TT
1281 objfile->per_bfd->msymbol_hash[i] = 0;
1282 objfile->per_bfd->msymbol_demangled_hash[i] = 0;
afbb8d7a
KB
1283 }
1284
025bb325 1285 /* Now, (re)insert the actual entries. */
34643a32 1286 for ((i = objfile->per_bfd->minimal_symbol_count,
042d75e4 1287 msym = objfile->per_bfd->msymbols.get ());
afbb8d7a
KB
1288 i > 0;
1289 i--, msym++)
1290 {
1291 msym->hash_next = 0;
34643a32 1292 add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash);
afbb8d7a
KB
1293
1294 msym->demangled_hash_next = 0;
efd66ac6 1295 if (MSYMBOL_SEARCH_NAME (msym) != MSYMBOL_LINKAGE_NAME (msym))
b5ec771e 1296 add_minsym_to_demangled_hash_table (msym, objfile);
afbb8d7a
KB
1297 }
1298}
1299
c906108c
SS
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
79e7ae11 1304 symbols) to an existing objfile. */
c906108c
SS
1305
1306void
d25e8719 1307minimal_symbol_reader::install ()
c906108c 1308{
52f0bd74
AC
1309 int mcount;
1310 struct msym_bunch *bunch;
1311 struct minimal_symbol *msymbols;
c906108c 1312 int alloc_count;
c906108c 1313
d25e8719 1314 if (m_objfile->per_bfd->minsyms_read)
34643a32
TT
1315 return;
1316
8dddcb8f 1317 if (m_msym_count > 0)
c906108c 1318 {
45cfd468
DE
1319 if (symtab_create_debug)
1320 {
1321 fprintf_unfiltered (gdb_stdlog,
1322 "Installing %d minimal symbols of objfile %s.\n",
8dddcb8f 1323 m_msym_count, objfile_name (m_objfile));
45cfd468
DE
1324 }
1325
79e7ae11
TT
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. */
c906108c 1330
741d7538 1331 alloc_count = m_msym_count + m_objfile->per_bfd->minimal_symbol_count;
042d75e4
TT
1332 gdb::unique_xmalloc_ptr<minimal_symbol>
1333 msym_holder (XNEWVEC (minimal_symbol, alloc_count));
1334 msymbols = msym_holder.get ();
c906108c
SS
1335
1336 /* Copy in the existing minimal symbols, if there are any. */
1337
d25e8719 1338 if (m_objfile->per_bfd->minimal_symbol_count)
042d75e4
TT
1339 memcpy (msymbols, m_objfile->per_bfd->msymbols.get (),
1340 m_objfile->per_bfd->minimal_symbol_count
1341 * sizeof (struct minimal_symbol));
c906108c
SS
1342
1343 /* Walk through the list of minimal symbol bunches, adding each symbol
c5aa993b
JM
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
025bb325 1347 each bunch is full. */
c5aa993b 1348
d25e8719 1349 mcount = m_objfile->per_bfd->minimal_symbol_count;
c5aa993b 1350
8dddcb8f 1351 for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next)
c906108c 1352 {
0de2420c
TT
1353 memcpy (&msymbols[mcount], &bunch->contents[0],
1354 m_msym_bunch_index * sizeof (struct minimal_symbol));
1355 mcount += m_msym_bunch_index;
8dddcb8f 1356 m_msym_bunch_index = BUNCH_SIZE;
c906108c
SS
1357 }
1358
1359 /* Sort the minimal symbols by address. */
c5aa993b 1360
c906108c
SS
1361 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
1362 compare_minimal_symbols);
c5aa993b 1363
c906108c 1364 /* Compact out any duplicates, and free up whatever space we are
c5aa993b
JM
1365 no longer using. */
1366
d25e8719 1367 mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
042d75e4
TT
1368 msym_holder.reset (XRESIZEVEC (struct minimal_symbol,
1369 msym_holder.release (),
1370 mcount));
c906108c 1371
c906108c 1372 /* Attach the minimal symbol table to the specified objfile.
34643a32 1373 The strings themselves are also located in the storage_obstack
c5aa993b 1374 of this objfile. */
c906108c 1375
d25e8719 1376 m_objfile->per_bfd->minimal_symbol_count = mcount;
042d75e4 1377 m_objfile->per_bfd->msymbols = std::move (msym_holder);
c906108c 1378
d25e8719 1379 build_minimal_symbol_hash_tables (m_objfile);
c906108c
SS
1380 }
1381}
1382
c9630d9c
TT
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. */
c906108c 1386
c9630d9c 1387static struct minimal_symbol *
fba45db2 1388lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
c906108c 1389{
20944a6e
PA
1390 bound_minimal_symbol msymbol
1391 = lookup_minimal_symbol_by_pc_section (pc, NULL,
1392 lookup_msym_prefer::TRAMPOLINE);
c906108c 1393
7cbd4a93
TT
1394 if (msymbol.minsym != NULL
1395 && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
1396 return msymbol.minsym;
c906108c
SS
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
025bb325 1407 is considered bad programming style. We could return 0 if we find
c906108c
SS
1408 a duplicate function in case this matters someday. */
1409
1410CORE_ADDR
52f729a7 1411find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
c906108c 1412{
c906108c
SS
1413 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1414
1415 if (tsymbol != NULL)
1416 {
2030c079 1417 for (objfile *objfile : current_program_space->objfiles ())
5325b9bf 1418 {
7932255d 1419 for (minimal_symbol *msymbol : objfile->msymbols ())
5325b9bf
TT
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;
b8d56208 1431
5325b9bf
TT
1432 /* Ignore data symbols that are not function
1433 descriptors. */
1434 if (msymbol_is_function (objfile, msymbol, &func))
1435 return func;
1436 }
1437 }
1438 }
c906108c
SS
1439 }
1440 return 0;
1441}
50e65b17
TT
1442
1443/* See minsyms.h. */
1444
1445CORE_ADDR
1446minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
1447{
50e65b17
TT
1448 short section;
1449 struct obj_section *obj_section;
1450 CORE_ADDR result;
20dc7e9b 1451 struct minimal_symbol *iter, *msymbol;
50e65b17
TT
1452
1453 gdb_assert (minsym.minsym != NULL);
1454
1455 /* If the minimal symbol has a size, use it. Otherwise use the
1456 lesser of the next minimal symbol in the same section, or the end
1457 of the section, as the end of the function. */
1458
1459 if (MSYMBOL_SIZE (minsym.minsym) != 0)
77e371c0 1460 return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
50e65b17
TT
1461
1462 /* Step over other symbols at this same address, and symbols in
1463 other sections, to find the next symbol in this section with a
1464 different address. */
1465
20dc7e9b
PW
1466 struct minimal_symbol *past_the_end
1467 = (minsym.objfile->per_bfd->msymbols.get ()
1468 + minsym.objfile->per_bfd->minimal_symbol_count);
50e65b17 1469 msymbol = minsym.minsym;
efd66ac6 1470 section = MSYMBOL_SECTION (msymbol);
20dc7e9b 1471 for (iter = msymbol + 1; iter != past_the_end; ++iter)
50e65b17 1472 {
20dc7e9b 1473 if ((MSYMBOL_VALUE_RAW_ADDRESS (iter)
77e371c0 1474 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
20dc7e9b 1475 && MSYMBOL_SECTION (iter) == section)
50e65b17
TT
1476 break;
1477 }
1478
efd66ac6 1479 obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
20dc7e9b
PW
1480 if (iter != past_the_end
1481 && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter)
efd66ac6 1482 < obj_section_endaddr (obj_section)))
20dc7e9b 1483 result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter);
50e65b17
TT
1484 else
1485 /* We got the start address from the last msymbol in the objfile.
1486 So the end address is the end of the section. */
1487 result = obj_section_endaddr (obj_section);
1488
1489 return result;
1490}
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