Change minimal_symbol_reader to store objfile
[deliverable/binutils-gdb.git] / gdb / minsyms.c
1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright (C) 1992-2016 Free Software Foundation, Inc.
3 Contributed by Cygnus Support, using pieces from other GDB modules.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20
21 /* This file contains support routines for creating, manipulating, and
22 destroying minimal symbol tables.
23
24 Minimal symbol tables are used to hold some very basic information about
25 all defined global symbols (text, data, bss, abs, etc). The only two
26 required pieces of information are the symbol's name and the address
27 associated with that symbol.
28
29 In many cases, even if a file was compiled with no special options for
30 debugging at all, as long as was not stripped it will contain sufficient
31 information to build useful minimal symbol tables using this structure.
32
33 Even when a file contains enough debugging information to build a full
34 symbol table, these minimal symbols are still useful for quickly mapping
35 between names and addresses, and vice versa. They are also sometimes used
36 to figure out what full symbol table entries need to be read in. */
37
38
39 #include "defs.h"
40 #include <ctype.h>
41 #include "symtab.h"
42 #include "bfd.h"
43 #include "filenames.h"
44 #include "symfile.h"
45 #include "objfiles.h"
46 #include "demangle.h"
47 #include "value.h"
48 #include "cp-abi.h"
49 #include "target.h"
50 #include "cp-support.h"
51 #include "language.h"
52 #include "cli/cli-utils.h"
53 #include "symbol.h"
54
55 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
56 At the end, copy them all into one newly allocated location on an objfile's
57 per-BFD storage obstack. */
58
59 #define BUNCH_SIZE 127
60
61 struct msym_bunch
62 {
63 struct msym_bunch *next;
64 struct minimal_symbol contents[BUNCH_SIZE];
65 };
66
67 /* Bunch currently being filled up.
68 The next field points to chain of filled bunches. */
69
70 static struct msym_bunch *msym_bunch;
71
72 /* Number of slots filled in current bunch. */
73
74 static int msym_bunch_index;
75
76 /* Total number of minimal symbols recorded so far for the objfile. */
77
78 static int msym_count;
79
80 /* See minsyms.h. */
81
82 unsigned int
83 msymbol_hash_iw (const char *string)
84 {
85 unsigned int hash = 0;
86
87 while (*string && *string != '(')
88 {
89 string = skip_spaces_const (string);
90 if (*string && *string != '(')
91 {
92 hash = SYMBOL_HASH_NEXT (hash, *string);
93 ++string;
94 }
95 }
96 return hash;
97 }
98
99 /* See minsyms.h. */
100
101 unsigned int
102 msymbol_hash (const char *string)
103 {
104 unsigned int hash = 0;
105
106 for (; *string; ++string)
107 hash = SYMBOL_HASH_NEXT (hash, *string);
108 return hash;
109 }
110
111 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
112 static void
113 add_minsym_to_hash_table (struct minimal_symbol *sym,
114 struct minimal_symbol **table)
115 {
116 if (sym->hash_next == NULL)
117 {
118 unsigned int hash
119 = msymbol_hash (MSYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
120
121 sym->hash_next = table[hash];
122 table[hash] = sym;
123 }
124 }
125
126 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
127 TABLE. */
128 static void
129 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
130 struct minimal_symbol **table)
131 {
132 if (sym->demangled_hash_next == NULL)
133 {
134 unsigned int hash = msymbol_hash_iw (MSYMBOL_SEARCH_NAME (sym))
135 % MINIMAL_SYMBOL_HASH_SIZE;
136
137 sym->demangled_hash_next = table[hash];
138 table[hash] = sym;
139 }
140 }
141
142 /* Look through all the current minimal symbol tables and find the
143 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
144 the search to that objfile. If SFILE is non-NULL, the only file-scope
145 symbols considered will be from that source file (global symbols are
146 still preferred). Returns a pointer to the minimal symbol that
147 matches, or NULL if no match is found.
148
149 Note: One instance where there may be duplicate minimal symbols with
150 the same name is when the symbol tables for a shared library and the
151 symbol tables for an executable contain global symbols with the same
152 names (the dynamic linker deals with the duplication).
153
154 It's also possible to have minimal symbols with different mangled
155 names, but identical demangled names. For example, the GNU C++ v3
156 ABI requires the generation of two (or perhaps three) copies of
157 constructor functions --- "in-charge", "not-in-charge", and
158 "allocate" copies; destructors may be duplicated as well.
159 Obviously, there must be distinct mangled names for each of these,
160 but the demangled names are all the same: S::S or S::~S. */
161
162 struct bound_minimal_symbol
163 lookup_minimal_symbol (const char *name, const char *sfile,
164 struct objfile *objf)
165 {
166 struct objfile *objfile;
167 struct bound_minimal_symbol found_symbol = { NULL, NULL };
168 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
169 struct bound_minimal_symbol trampoline_symbol = { NULL, NULL };
170
171 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
172 unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
173
174 int needtofreename = 0;
175 const char *modified_name;
176
177 if (sfile != NULL)
178 sfile = lbasename (sfile);
179
180 /* For C++, canonicalize the input name. */
181 modified_name = name;
182 if (current_language->la_language == language_cplus)
183 {
184 char *cname = cp_canonicalize_string (name);
185
186 if (cname)
187 {
188 modified_name = cname;
189 needtofreename = 1;
190 }
191 }
192
193 for (objfile = object_files;
194 objfile != NULL && found_symbol.minsym == NULL;
195 objfile = objfile->next)
196 {
197 struct minimal_symbol *msymbol;
198
199 if (objf == NULL || objf == objfile
200 || objf == objfile->separate_debug_objfile_backlink)
201 {
202 /* Do two passes: the first over the ordinary hash table,
203 and the second over the demangled hash table. */
204 int pass;
205
206 if (symbol_lookup_debug)
207 {
208 fprintf_unfiltered (gdb_stdlog,
209 "lookup_minimal_symbol (%s, %s, %s)\n",
210 name, sfile != NULL ? sfile : "NULL",
211 objfile_debug_name (objfile));
212 }
213
214 for (pass = 1; pass <= 2 && found_symbol.minsym == NULL; pass++)
215 {
216 /* Select hash list according to pass. */
217 if (pass == 1)
218 msymbol = objfile->per_bfd->msymbol_hash[hash];
219 else
220 msymbol = objfile->per_bfd->msymbol_demangled_hash[dem_hash];
221
222 while (msymbol != NULL && found_symbol.minsym == NULL)
223 {
224 int match;
225
226 if (pass == 1)
227 {
228 int (*cmp) (const char *, const char *);
229
230 cmp = (case_sensitivity == case_sensitive_on
231 ? strcmp : strcasecmp);
232 match = cmp (MSYMBOL_LINKAGE_NAME (msymbol),
233 modified_name) == 0;
234 }
235 else
236 {
237 /* The function respects CASE_SENSITIVITY. */
238 match = MSYMBOL_MATCHES_SEARCH_NAME (msymbol,
239 modified_name);
240 }
241
242 if (match)
243 {
244 switch (MSYMBOL_TYPE (msymbol))
245 {
246 case mst_file_text:
247 case mst_file_data:
248 case mst_file_bss:
249 if (sfile == NULL
250 || filename_cmp (msymbol->filename, sfile) == 0)
251 {
252 found_file_symbol.minsym = msymbol;
253 found_file_symbol.objfile = objfile;
254 }
255 break;
256
257 case mst_solib_trampoline:
258
259 /* If a trampoline symbol is found, we prefer to
260 keep looking for the *real* symbol. If the
261 actual symbol is not found, then we'll use the
262 trampoline entry. */
263 if (trampoline_symbol.minsym == NULL)
264 {
265 trampoline_symbol.minsym = msymbol;
266 trampoline_symbol.objfile = objfile;
267 }
268 break;
269
270 case mst_unknown:
271 default:
272 found_symbol.minsym = msymbol;
273 found_symbol.objfile = objfile;
274 break;
275 }
276 }
277
278 /* Find the next symbol on the hash chain. */
279 if (pass == 1)
280 msymbol = msymbol->hash_next;
281 else
282 msymbol = msymbol->demangled_hash_next;
283 }
284 }
285 }
286 }
287
288 if (needtofreename)
289 xfree ((void *) modified_name);
290
291 /* External symbols are best. */
292 if (found_symbol.minsym != NULL)
293 {
294 if (symbol_lookup_debug)
295 {
296 fprintf_unfiltered (gdb_stdlog,
297 "lookup_minimal_symbol (...) = %s"
298 " (external)\n",
299 host_address_to_string (found_symbol.minsym));
300 }
301 return found_symbol;
302 }
303
304 /* File-local symbols are next best. */
305 if (found_file_symbol.minsym != NULL)
306 {
307 if (symbol_lookup_debug)
308 {
309 fprintf_unfiltered (gdb_stdlog,
310 "lookup_minimal_symbol (...) = %s"
311 " (file-local)\n",
312 host_address_to_string
313 (found_file_symbol.minsym));
314 }
315 return found_file_symbol;
316 }
317
318 /* Symbols for shared library trampolines are next best. */
319 if (symbol_lookup_debug)
320 {
321 fprintf_unfiltered (gdb_stdlog,
322 "lookup_minimal_symbol (...) = %s%s\n",
323 trampoline_symbol.minsym != NULL
324 ? host_address_to_string (trampoline_symbol.minsym)
325 : "NULL",
326 trampoline_symbol.minsym != NULL
327 ? " (trampoline)" : "");
328 }
329 return trampoline_symbol;
330 }
331
332 /* See minsyms.h. */
333
334 struct bound_minimal_symbol
335 lookup_bound_minimal_symbol (const char *name)
336 {
337 return lookup_minimal_symbol (name, NULL, NULL);
338 }
339
340 /* See common/symbol.h. */
341
342 int
343 find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
344 struct objfile *objfile)
345 {
346 struct bound_minimal_symbol sym
347 = lookup_minimal_symbol (name, NULL, objfile);
348
349 if (sym.minsym != NULL)
350 *addr = BMSYMBOL_VALUE_ADDRESS (sym);
351
352 return sym.minsym == NULL;
353 }
354
355 /* See minsyms.h. */
356
357 void
358 iterate_over_minimal_symbols (struct objfile *objf, const char *name,
359 void (*callback) (struct minimal_symbol *,
360 void *),
361 void *user_data)
362 {
363 unsigned int hash;
364 struct minimal_symbol *iter;
365 int (*cmp) (const char *, const char *);
366
367 /* The first pass is over the ordinary hash table. */
368 hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
369 iter = objf->per_bfd->msymbol_hash[hash];
370 cmp = (case_sensitivity == case_sensitive_on ? strcmp : strcasecmp);
371 while (iter)
372 {
373 if (cmp (MSYMBOL_LINKAGE_NAME (iter), name) == 0)
374 (*callback) (iter, user_data);
375 iter = iter->hash_next;
376 }
377
378 /* The second pass is over the demangled table. */
379 hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
380 iter = objf->per_bfd->msymbol_demangled_hash[hash];
381 while (iter)
382 {
383 if (MSYMBOL_MATCHES_SEARCH_NAME (iter, name))
384 (*callback) (iter, user_data);
385 iter = iter->demangled_hash_next;
386 }
387 }
388
389 /* See minsyms.h. */
390
391 struct bound_minimal_symbol
392 lookup_minimal_symbol_text (const char *name, struct objfile *objf)
393 {
394 struct objfile *objfile;
395 struct minimal_symbol *msymbol;
396 struct bound_minimal_symbol found_symbol = { NULL, NULL };
397 struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
398
399 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
400
401 for (objfile = object_files;
402 objfile != NULL && found_symbol.minsym == NULL;
403 objfile = objfile->next)
404 {
405 if (objf == NULL || objf == objfile
406 || objf == objfile->separate_debug_objfile_backlink)
407 {
408 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
409 msymbol != NULL && found_symbol.minsym == NULL;
410 msymbol = msymbol->hash_next)
411 {
412 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
413 (MSYMBOL_TYPE (msymbol) == mst_text
414 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
415 || MSYMBOL_TYPE (msymbol) == mst_file_text))
416 {
417 switch (MSYMBOL_TYPE (msymbol))
418 {
419 case mst_file_text:
420 found_file_symbol.minsym = msymbol;
421 found_file_symbol.objfile = objfile;
422 break;
423 default:
424 found_symbol.minsym = msymbol;
425 found_symbol.objfile = objfile;
426 break;
427 }
428 }
429 }
430 }
431 }
432 /* External symbols are best. */
433 if (found_symbol.minsym)
434 return found_symbol;
435
436 /* File-local symbols are next best. */
437 return found_file_symbol;
438 }
439
440 /* See minsyms.h. */
441
442 struct minimal_symbol *
443 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name,
444 struct objfile *objf)
445 {
446 struct objfile *objfile;
447 struct minimal_symbol *msymbol;
448
449 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
450
451 for (objfile = object_files;
452 objfile != NULL;
453 objfile = objfile->next)
454 {
455 if (objf == NULL || objf == objfile
456 || objf == objfile->separate_debug_objfile_backlink)
457 {
458 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
459 msymbol != NULL;
460 msymbol = msymbol->hash_next)
461 {
462 if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
463 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0)
464 return msymbol;
465 }
466 }
467 }
468
469 return NULL;
470 }
471
472 /* See minsyms.h. */
473
474 struct bound_minimal_symbol
475 lookup_minimal_symbol_solib_trampoline (const char *name,
476 struct objfile *objf)
477 {
478 struct objfile *objfile;
479 struct minimal_symbol *msymbol;
480 struct bound_minimal_symbol found_symbol = { NULL, NULL };
481
482 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
483
484 for (objfile = object_files;
485 objfile != NULL;
486 objfile = objfile->next)
487 {
488 if (objf == NULL || objf == objfile
489 || objf == objfile->separate_debug_objfile_backlink)
490 {
491 for (msymbol = objfile->per_bfd->msymbol_hash[hash];
492 msymbol != NULL;
493 msymbol = msymbol->hash_next)
494 {
495 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
496 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
497 {
498 found_symbol.objfile = objfile;
499 found_symbol.minsym = msymbol;
500 return found_symbol;
501 }
502 }
503 }
504 }
505
506 return found_symbol;
507 }
508
509 /* A helper function that makes *PC section-relative. This searches
510 the sections of OBJFILE and if *PC is in a section, it subtracts
511 the section offset and returns true. Otherwise it returns
512 false. */
513
514 static int
515 frob_address (struct objfile *objfile, CORE_ADDR *pc)
516 {
517 struct obj_section *iter;
518
519 ALL_OBJFILE_OSECTIONS (objfile, iter)
520 {
521 if (*pc >= obj_section_addr (iter) && *pc < obj_section_endaddr (iter))
522 {
523 *pc -= obj_section_offset (iter);
524 return 1;
525 }
526 }
527
528 return 0;
529 }
530
531 /* Search through the minimal symbol table for each objfile and find
532 the symbol whose address is the largest address that is still less
533 than or equal to PC, and matches SECTION (which is not NULL).
534 Returns a pointer to the minimal symbol if such a symbol is found,
535 or NULL if PC is not in a suitable range.
536 Note that we need to look through ALL the minimal symbol tables
537 before deciding on the symbol that comes closest to the specified PC.
538 This is because objfiles can overlap, for example objfile A has .text
539 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
540 .data at 0x40048.
541
542 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
543 there are text and trampoline symbols at the same address.
544 Otherwise prefer mst_text symbols. */
545
546 static struct bound_minimal_symbol
547 lookup_minimal_symbol_by_pc_section_1 (CORE_ADDR pc_in,
548 struct obj_section *section,
549 int want_trampoline)
550 {
551 int lo;
552 int hi;
553 int newobj;
554 struct objfile *objfile;
555 struct minimal_symbol *msymbol;
556 struct minimal_symbol *best_symbol = NULL;
557 struct objfile *best_objfile = NULL;
558 struct bound_minimal_symbol result;
559 enum minimal_symbol_type want_type, other_type;
560
561 want_type = want_trampoline ? mst_solib_trampoline : mst_text;
562 other_type = want_trampoline ? mst_text : mst_solib_trampoline;
563
564 /* We can not require the symbol found to be in section, because
565 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
566 symbol - but find_pc_section won't return an absolute section and
567 hence the code below would skip over absolute symbols. We can
568 still take advantage of the call to find_pc_section, though - the
569 object file still must match. In case we have separate debug
570 files, search both the file and its separate debug file. There's
571 no telling which one will have the minimal symbols. */
572
573 gdb_assert (section != NULL);
574
575 for (objfile = section->objfile;
576 objfile != NULL;
577 objfile = objfile_separate_debug_iterate (section->objfile, objfile))
578 {
579 CORE_ADDR pc = pc_in;
580
581 /* If this objfile has a minimal symbol table, go search it using
582 a binary search. Note that a minimal symbol table always consists
583 of at least two symbols, a "real" symbol and the terminating
584 "null symbol". If there are no real symbols, then there is no
585 minimal symbol table at all. */
586
587 if (objfile->per_bfd->minimal_symbol_count > 0)
588 {
589 int best_zero_sized = -1;
590
591 msymbol = objfile->per_bfd->msymbols;
592 lo = 0;
593 hi = objfile->per_bfd->minimal_symbol_count - 1;
594
595 /* This code assumes that the minimal symbols are sorted by
596 ascending address values. If the pc value is greater than or
597 equal to the first symbol's address, then some symbol in this
598 minimal symbol table is a suitable candidate for being the
599 "best" symbol. This includes the last real symbol, for cases
600 where the pc value is larger than any address in this vector.
601
602 By iterating until the address associated with the current
603 hi index (the endpoint of the test interval) is less than
604 or equal to the desired pc value, we accomplish two things:
605 (1) the case where the pc value is larger than any minimal
606 symbol address is trivially solved, (2) the address associated
607 with the hi index is always the one we want when the interation
608 terminates. In essence, we are iterating the test interval
609 down until the pc value is pushed out of it from the high end.
610
611 Warning: this code is trickier than it would appear at first. */
612
613 if (frob_address (objfile, &pc)
614 && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo]))
615 {
616 while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc)
617 {
618 /* pc is still strictly less than highest address. */
619 /* Note "new" will always be >= lo. */
620 newobj = (lo + hi) / 2;
621 if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc)
622 || (lo == newobj))
623 {
624 hi = newobj;
625 }
626 else
627 {
628 lo = newobj;
629 }
630 }
631
632 /* If we have multiple symbols at the same address, we want
633 hi to point to the last one. That way we can find the
634 right symbol if it has an index greater than hi. */
635 while (hi < objfile->per_bfd->minimal_symbol_count - 1
636 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
637 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1])))
638 hi++;
639
640 /* Skip various undesirable symbols. */
641 while (hi >= 0)
642 {
643 /* Skip any absolute symbols. This is apparently
644 what adb and dbx do, and is needed for the CM-5.
645 There are two known possible problems: (1) on
646 ELF, apparently end, edata, etc. are absolute.
647 Not sure ignoring them here is a big deal, but if
648 we want to use them, the fix would go in
649 elfread.c. (2) I think shared library entry
650 points on the NeXT are absolute. If we want
651 special handling for this it probably should be
652 triggered by a special mst_abs_or_lib or some
653 such. */
654
655 if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs)
656 {
657 hi--;
658 continue;
659 }
660
661 /* If SECTION was specified, skip any symbol from
662 wrong section. */
663 if (section
664 /* Some types of debug info, such as COFF,
665 don't fill the bfd_section member, so don't
666 throw away symbols on those platforms. */
667 && MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]) != NULL
668 && (!matching_obj_sections
669 (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]),
670 section)))
671 {
672 hi--;
673 continue;
674 }
675
676 /* If we are looking for a trampoline and this is a
677 text symbol, or the other way around, check the
678 preceding symbol too. If they are otherwise
679 identical prefer that one. */
680 if (hi > 0
681 && MSYMBOL_TYPE (&msymbol[hi]) == other_type
682 && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type
683 && (MSYMBOL_SIZE (&msymbol[hi])
684 == MSYMBOL_SIZE (&msymbol[hi - 1]))
685 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
686 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]))
687 && (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi])
688 == MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi - 1])))
689 {
690 hi--;
691 continue;
692 }
693
694 /* If the minimal symbol has a zero size, save it
695 but keep scanning backwards looking for one with
696 a non-zero size. A zero size may mean that the
697 symbol isn't an object or function (e.g. a
698 label), or it may just mean that the size was not
699 specified. */
700 if (MSYMBOL_SIZE (&msymbol[hi]) == 0)
701 {
702 if (best_zero_sized == -1)
703 best_zero_sized = hi;
704 hi--;
705 continue;
706 }
707
708 /* If we are past the end of the current symbol, try
709 the previous symbol if it has a larger overlapping
710 size. This happens on i686-pc-linux-gnu with glibc;
711 the nocancel variants of system calls are inside
712 the cancellable variants, but both have sizes. */
713 if (hi > 0
714 && MSYMBOL_SIZE (&msymbol[hi]) != 0
715 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
716 + MSYMBOL_SIZE (&msymbol[hi]))
717 && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])
718 + MSYMBOL_SIZE (&msymbol[hi - 1])))
719 {
720 hi--;
721 continue;
722 }
723
724 /* Otherwise, this symbol must be as good as we're going
725 to get. */
726 break;
727 }
728
729 /* If HI has a zero size, and best_zero_sized is set,
730 then we had two or more zero-sized symbols; prefer
731 the first one we found (which may have a higher
732 address). Also, if we ran off the end, be sure
733 to back up. */
734 if (best_zero_sized != -1
735 && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
736 hi = best_zero_sized;
737
738 /* If the minimal symbol has a non-zero size, and this
739 PC appears to be outside the symbol's contents, then
740 refuse to use this symbol. If we found a zero-sized
741 symbol with an address greater than this symbol's,
742 use that instead. We assume that if symbols have
743 specified sizes, they do not overlap. */
744
745 if (hi >= 0
746 && MSYMBOL_SIZE (&msymbol[hi]) != 0
747 && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
748 + MSYMBOL_SIZE (&msymbol[hi])))
749 {
750 if (best_zero_sized != -1)
751 hi = best_zero_sized;
752 else
753 /* Go on to the next object file. */
754 continue;
755 }
756
757 /* The minimal symbol indexed by hi now is the best one in this
758 objfile's minimal symbol table. See if it is the best one
759 overall. */
760
761 if (hi >= 0
762 && ((best_symbol == NULL) ||
763 (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) <
764 MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]))))
765 {
766 best_symbol = &msymbol[hi];
767 best_objfile = objfile;
768 }
769 }
770 }
771 }
772
773 result.minsym = best_symbol;
774 result.objfile = best_objfile;
775 return result;
776 }
777
778 struct bound_minimal_symbol
779 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, struct obj_section *section)
780 {
781 if (section == NULL)
782 {
783 /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
784 force the section but that (well unless you're doing overlay
785 debugging) always returns NULL making the call somewhat useless. */
786 section = find_pc_section (pc);
787 if (section == NULL)
788 {
789 struct bound_minimal_symbol result;
790
791 memset (&result, 0, sizeof (result));
792 return result;
793 }
794 }
795 return lookup_minimal_symbol_by_pc_section_1 (pc, section, 0);
796 }
797
798 /* See minsyms.h. */
799
800 struct bound_minimal_symbol
801 lookup_minimal_symbol_by_pc (CORE_ADDR pc)
802 {
803 struct obj_section *section = find_pc_section (pc);
804
805 if (section == NULL)
806 {
807 struct bound_minimal_symbol result;
808
809 memset (&result, 0, sizeof (result));
810 return result;
811 }
812 return lookup_minimal_symbol_by_pc_section_1 (pc, section, 0);
813 }
814
815 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
816
817 int
818 in_gnu_ifunc_stub (CORE_ADDR pc)
819 {
820 struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (pc);
821
822 return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc;
823 }
824
825 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */
826
827 static CORE_ADDR
828 stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
829 {
830 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
831 "the ELF support compiled in."),
832 paddress (gdbarch, pc));
833 }
834
835 /* See elf_gnu_ifunc_resolve_name for its real implementation. */
836
837 static int
838 stub_gnu_ifunc_resolve_name (const char *function_name,
839 CORE_ADDR *function_address_p)
840 {
841 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
842 "the ELF support compiled in."),
843 function_name);
844 }
845
846 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */
847
848 static void
849 stub_gnu_ifunc_resolver_stop (struct breakpoint *b)
850 {
851 internal_error (__FILE__, __LINE__,
852 _("elf_gnu_ifunc_resolver_stop cannot be reached."));
853 }
854
855 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
856
857 static void
858 stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
859 {
860 internal_error (__FILE__, __LINE__,
861 _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
862 }
863
864 /* See elf_gnu_ifunc_fns for its real implementation. */
865
866 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns =
867 {
868 stub_gnu_ifunc_resolve_addr,
869 stub_gnu_ifunc_resolve_name,
870 stub_gnu_ifunc_resolver_stop,
871 stub_gnu_ifunc_resolver_return_stop,
872 };
873
874 /* A placeholder for &elf_gnu_ifunc_fns. */
875
876 const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns;
877
878 /* See minsyms.h. */
879
880 struct bound_minimal_symbol
881 lookup_minimal_symbol_and_objfile (const char *name)
882 {
883 struct bound_minimal_symbol result;
884 struct objfile *objfile;
885 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
886
887 ALL_OBJFILES (objfile)
888 {
889 struct minimal_symbol *msym;
890
891 for (msym = objfile->per_bfd->msymbol_hash[hash];
892 msym != NULL;
893 msym = msym->hash_next)
894 {
895 if (strcmp (MSYMBOL_LINKAGE_NAME (msym), name) == 0)
896 {
897 result.minsym = msym;
898 result.objfile = objfile;
899 return result;
900 }
901 }
902 }
903
904 memset (&result, 0, sizeof (result));
905 return result;
906 }
907 \f
908
909 /* Return leading symbol character for a BFD. If BFD is NULL,
910 return the leading symbol character from the main objfile. */
911
912 static int
913 get_symbol_leading_char (bfd *abfd)
914 {
915 if (abfd != NULL)
916 return bfd_get_symbol_leading_char (abfd);
917 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
918 return bfd_get_symbol_leading_char (symfile_objfile->obfd);
919 return 0;
920 }
921
922 /* See minsyms.h. */
923
924 minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj)
925 : m_objfile (obj)
926 {
927 msym_count = 0;
928 msym_bunch = NULL;
929 /* Note that presetting msym_bunch_index to BUNCH_SIZE causes the
930 first call to save a minimal symbol to allocate the memory for
931 the first bunch. */
932 msym_bunch_index = BUNCH_SIZE;
933 }
934
935 /* Discard the currently collected minimal symbols, if any. If we wish
936 to save them for later use, we must have already copied them somewhere
937 else before calling this function.
938
939 FIXME: We could allocate the minimal symbol bunches on their own
940 obstack and then simply blow the obstack away when we are done with
941 it. Is it worth the extra trouble though? */
942
943 minimal_symbol_reader::~minimal_symbol_reader ()
944 {
945 struct msym_bunch *next;
946
947 while (msym_bunch != NULL)
948 {
949 next = msym_bunch->next;
950 xfree (msym_bunch);
951 msym_bunch = next;
952 }
953 }
954
955 /* See minsyms.h. */
956
957 void
958 prim_record_minimal_symbol (const char *name, CORE_ADDR address,
959 enum minimal_symbol_type ms_type,
960 struct objfile *objfile)
961 {
962 int section;
963
964 switch (ms_type)
965 {
966 case mst_text:
967 case mst_text_gnu_ifunc:
968 case mst_file_text:
969 case mst_solib_trampoline:
970 section = SECT_OFF_TEXT (objfile);
971 break;
972 case mst_data:
973 case mst_file_data:
974 section = SECT_OFF_DATA (objfile);
975 break;
976 case mst_bss:
977 case mst_file_bss:
978 section = SECT_OFF_BSS (objfile);
979 break;
980 default:
981 section = -1;
982 }
983
984 prim_record_minimal_symbol_and_info (name, address, ms_type,
985 section, objfile);
986 }
987
988 /* See minsyms.h. */
989
990 struct minimal_symbol *
991 prim_record_minimal_symbol_full (const char *name, int name_len, int copy_name,
992 CORE_ADDR address,
993 enum minimal_symbol_type ms_type,
994 int section,
995 struct objfile *objfile)
996 {
997 struct msym_bunch *newobj;
998 struct minimal_symbol *msymbol;
999
1000 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
1001 the minimal symbols, because if there is also another symbol
1002 at the same address (e.g. the first function of the file),
1003 lookup_minimal_symbol_by_pc would have no way of getting the
1004 right one. */
1005 if (ms_type == mst_file_text && name[0] == 'g'
1006 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
1007 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
1008 return (NULL);
1009
1010 /* It's safe to strip the leading char here once, since the name
1011 is also stored stripped in the minimal symbol table. */
1012 if (name[0] == get_symbol_leading_char (objfile->obfd))
1013 {
1014 ++name;
1015 --name_len;
1016 }
1017
1018 if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
1019 return (NULL);
1020
1021 if (msym_bunch_index == BUNCH_SIZE)
1022 {
1023 newobj = XCNEW (struct msym_bunch);
1024 msym_bunch_index = 0;
1025 newobj->next = msym_bunch;
1026 msym_bunch = newobj;
1027 }
1028 msymbol = &msym_bunch->contents[msym_bunch_index];
1029 MSYMBOL_SET_LANGUAGE (msymbol, language_auto,
1030 &objfile->per_bfd->storage_obstack);
1031 MSYMBOL_SET_NAMES (msymbol, name, name_len, copy_name, objfile);
1032
1033 SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
1034 MSYMBOL_SECTION (msymbol) = section;
1035
1036 MSYMBOL_TYPE (msymbol) = ms_type;
1037 MSYMBOL_TARGET_FLAG_1 (msymbol) = 0;
1038 MSYMBOL_TARGET_FLAG_2 (msymbol) = 0;
1039 /* Do not use the SET_MSYMBOL_SIZE macro to initialize the size,
1040 as it would also set the has_size flag. */
1041 msymbol->size = 0;
1042
1043 /* The hash pointers must be cleared! If they're not,
1044 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
1045 msymbol->hash_next = NULL;
1046 msymbol->demangled_hash_next = NULL;
1047
1048 /* If we already read minimal symbols for this objfile, then don't
1049 ever allocate a new one. */
1050 if (!objfile->per_bfd->minsyms_read)
1051 {
1052 msym_bunch_index++;
1053 objfile->per_bfd->n_minsyms++;
1054 }
1055 msym_count++;
1056 return msymbol;
1057 }
1058
1059 /* See minsyms.h. */
1060
1061 struct minimal_symbol *
1062 prim_record_minimal_symbol_and_info (const char *name, CORE_ADDR address,
1063 enum minimal_symbol_type ms_type,
1064 int section,
1065 struct objfile *objfile)
1066 {
1067 return prim_record_minimal_symbol_full (name, strlen (name), 1,
1068 address, ms_type,
1069 section, objfile);
1070 }
1071
1072 /* Compare two minimal symbols by address and return a signed result based
1073 on unsigned comparisons, so that we sort into unsigned numeric order.
1074 Within groups with the same address, sort by name. */
1075
1076 static int
1077 compare_minimal_symbols (const void *fn1p, const void *fn2p)
1078 {
1079 const struct minimal_symbol *fn1;
1080 const struct minimal_symbol *fn2;
1081
1082 fn1 = (const struct minimal_symbol *) fn1p;
1083 fn2 = (const struct minimal_symbol *) fn2p;
1084
1085 if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) < MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1086 {
1087 return (-1); /* addr 1 is less than addr 2. */
1088 }
1089 else if (MSYMBOL_VALUE_RAW_ADDRESS (fn1) > MSYMBOL_VALUE_RAW_ADDRESS (fn2))
1090 {
1091 return (1); /* addr 1 is greater than addr 2. */
1092 }
1093 else
1094 /* addrs are equal: sort by name */
1095 {
1096 const char *name1 = MSYMBOL_LINKAGE_NAME (fn1);
1097 const char *name2 = MSYMBOL_LINKAGE_NAME (fn2);
1098
1099 if (name1 && name2) /* both have names */
1100 return strcmp (name1, name2);
1101 else if (name2)
1102 return 1; /* fn1 has no name, so it is "less". */
1103 else if (name1) /* fn2 has no name, so it is "less". */
1104 return -1;
1105 else
1106 return (0); /* Neither has a name, so they're equal. */
1107 }
1108 }
1109
1110 /* Compact duplicate entries out of a minimal symbol table by walking
1111 through the table and compacting out entries with duplicate addresses
1112 and matching names. Return the number of entries remaining.
1113
1114 On entry, the table resides between msymbol[0] and msymbol[mcount].
1115 On exit, it resides between msymbol[0] and msymbol[result_count].
1116
1117 When files contain multiple sources of symbol information, it is
1118 possible for the minimal symbol table to contain many duplicate entries.
1119 As an example, SVR4 systems use ELF formatted object files, which
1120 usually contain at least two different types of symbol tables (a
1121 standard ELF one and a smaller dynamic linking table), as well as
1122 DWARF debugging information for files compiled with -g.
1123
1124 Without compacting, the minimal symbol table for gdb itself contains
1125 over a 1000 duplicates, about a third of the total table size. Aside
1126 from the potential trap of not noticing that two successive entries
1127 identify the same location, this duplication impacts the time required
1128 to linearly scan the table, which is done in a number of places. So we
1129 just do one linear scan here and toss out the duplicates.
1130
1131 Note that we are not concerned here about recovering the space that
1132 is potentially freed up, because the strings themselves are allocated
1133 on the storage_obstack, and will get automatically freed when the symbol
1134 table is freed. The caller can free up the unused minimal symbols at
1135 the end of the compacted region if their allocation strategy allows it.
1136
1137 Also note we only go up to the next to last entry within the loop
1138 and then copy the last entry explicitly after the loop terminates.
1139
1140 Since the different sources of information for each symbol may
1141 have different levels of "completeness", we may have duplicates
1142 that have one entry with type "mst_unknown" and the other with a
1143 known type. So if the one we are leaving alone has type mst_unknown,
1144 overwrite its type with the type from the one we are compacting out. */
1145
1146 static int
1147 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
1148 struct objfile *objfile)
1149 {
1150 struct minimal_symbol *copyfrom;
1151 struct minimal_symbol *copyto;
1152
1153 if (mcount > 0)
1154 {
1155 copyfrom = copyto = msymbol;
1156 while (copyfrom < msymbol + mcount - 1)
1157 {
1158 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
1159 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
1160 && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
1161 && strcmp (MSYMBOL_LINKAGE_NAME (copyfrom),
1162 MSYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0)
1163 {
1164 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
1165 {
1166 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
1167 }
1168 copyfrom++;
1169 }
1170 else
1171 *copyto++ = *copyfrom++;
1172 }
1173 *copyto++ = *copyfrom++;
1174 mcount = copyto - msymbol;
1175 }
1176 return (mcount);
1177 }
1178
1179 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1180 after compacting or sorting the table since the entries move around
1181 thus causing the internal minimal_symbol pointers to become jumbled. */
1182
1183 static void
1184 build_minimal_symbol_hash_tables (struct objfile *objfile)
1185 {
1186 int i;
1187 struct minimal_symbol *msym;
1188
1189 /* Clear the hash tables. */
1190 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
1191 {
1192 objfile->per_bfd->msymbol_hash[i] = 0;
1193 objfile->per_bfd->msymbol_demangled_hash[i] = 0;
1194 }
1195
1196 /* Now, (re)insert the actual entries. */
1197 for ((i = objfile->per_bfd->minimal_symbol_count,
1198 msym = objfile->per_bfd->msymbols);
1199 i > 0;
1200 i--, msym++)
1201 {
1202 msym->hash_next = 0;
1203 add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash);
1204
1205 msym->demangled_hash_next = 0;
1206 if (MSYMBOL_SEARCH_NAME (msym) != MSYMBOL_LINKAGE_NAME (msym))
1207 add_minsym_to_demangled_hash_table (msym,
1208 objfile->per_bfd->msymbol_demangled_hash);
1209 }
1210 }
1211
1212 /* Add the minimal symbols in the existing bunches to the objfile's official
1213 minimal symbol table. In most cases there is no minimal symbol table yet
1214 for this objfile, and the existing bunches are used to create one. Once
1215 in a while (for shared libraries for example), we add symbols (e.g. common
1216 symbols) to an existing objfile.
1217
1218 Because of the way minimal symbols are collected, we generally have no way
1219 of knowing what source language applies to any particular minimal symbol.
1220 Specifically, we have no way of knowing if the minimal symbol comes from a
1221 C++ compilation unit or not. So for the sake of supporting cached
1222 demangled C++ names, we have no choice but to try and demangle each new one
1223 that comes in. If the demangling succeeds, then we assume it is a C++
1224 symbol and set the symbol's language and demangled name fields
1225 appropriately. Note that in order to avoid unnecessary demanglings, and
1226 allocating obstack space that subsequently can't be freed for the demangled
1227 names, we mark all newly added symbols with language_auto. After
1228 compaction of the minimal symbols, we go back and scan the entire minimal
1229 symbol table looking for these new symbols. For each new symbol we attempt
1230 to demangle it, and if successful, record it as a language_cplus symbol
1231 and cache the demangled form on the symbol obstack. Symbols which don't
1232 demangle are marked as language_unknown symbols, which inhibits future
1233 attempts to demangle them if we later add more minimal symbols. */
1234
1235 void
1236 minimal_symbol_reader::install ()
1237 {
1238 int bindex;
1239 int mcount;
1240 struct msym_bunch *bunch;
1241 struct minimal_symbol *msymbols;
1242 int alloc_count;
1243
1244 if (m_objfile->per_bfd->minsyms_read)
1245 return;
1246
1247 if (msym_count > 0)
1248 {
1249 if (symtab_create_debug)
1250 {
1251 fprintf_unfiltered (gdb_stdlog,
1252 "Installing %d minimal symbols of objfile %s.\n",
1253 msym_count, objfile_name (m_objfile));
1254 }
1255
1256 /* Allocate enough space in the obstack, into which we will gather the
1257 bunches of new and existing minimal symbols, sort them, and then
1258 compact out the duplicate entries. Once we have a final table,
1259 we will give back the excess space. */
1260
1261 alloc_count = msym_count + m_objfile->per_bfd->minimal_symbol_count + 1;
1262 obstack_blank (&m_objfile->per_bfd->storage_obstack,
1263 alloc_count * sizeof (struct minimal_symbol));
1264 msymbols = (struct minimal_symbol *)
1265 obstack_base (&m_objfile->per_bfd->storage_obstack);
1266
1267 /* Copy in the existing minimal symbols, if there are any. */
1268
1269 if (m_objfile->per_bfd->minimal_symbol_count)
1270 memcpy ((char *) msymbols, (char *) m_objfile->per_bfd->msymbols,
1271 m_objfile->per_bfd->minimal_symbol_count * sizeof (struct minimal_symbol));
1272
1273 /* Walk through the list of minimal symbol bunches, adding each symbol
1274 to the new contiguous array of symbols. Note that we start with the
1275 current, possibly partially filled bunch (thus we use the current
1276 msym_bunch_index for the first bunch we copy over), and thereafter
1277 each bunch is full. */
1278
1279 mcount = m_objfile->per_bfd->minimal_symbol_count;
1280
1281 for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
1282 {
1283 for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
1284 msymbols[mcount] = bunch->contents[bindex];
1285 msym_bunch_index = BUNCH_SIZE;
1286 }
1287
1288 /* Sort the minimal symbols by address. */
1289
1290 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
1291 compare_minimal_symbols);
1292
1293 /* Compact out any duplicates, and free up whatever space we are
1294 no longer using. */
1295
1296 mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
1297
1298 obstack_blank_fast (&m_objfile->per_bfd->storage_obstack,
1299 (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
1300 msymbols = (struct minimal_symbol *)
1301 obstack_finish (&m_objfile->per_bfd->storage_obstack);
1302
1303 /* We also terminate the minimal symbol table with a "null symbol",
1304 which is *not* included in the size of the table. This makes it
1305 easier to find the end of the table when we are handed a pointer
1306 to some symbol in the middle of it. Zero out the fields in the
1307 "null symbol" allocated at the end of the array. Note that the
1308 symbol count does *not* include this null symbol, which is why it
1309 is indexed by mcount and not mcount-1. */
1310
1311 memset (&msymbols[mcount], 0, sizeof (struct minimal_symbol));
1312
1313 /* Attach the minimal symbol table to the specified objfile.
1314 The strings themselves are also located in the storage_obstack
1315 of this objfile. */
1316
1317 m_objfile->per_bfd->minimal_symbol_count = mcount;
1318 m_objfile->per_bfd->msymbols = msymbols;
1319
1320 /* Now build the hash tables; we can't do this incrementally
1321 at an earlier point since we weren't finished with the obstack
1322 yet. (And if the msymbol obstack gets moved, all the internal
1323 pointers to other msymbols need to be adjusted.) */
1324 build_minimal_symbol_hash_tables (m_objfile);
1325 }
1326 }
1327
1328 /* See minsyms.h. */
1329
1330 void
1331 terminate_minimal_symbol_table (struct objfile *objfile)
1332 {
1333 if (! objfile->per_bfd->msymbols)
1334 objfile->per_bfd->msymbols
1335 = ((struct minimal_symbol *)
1336 obstack_alloc (&objfile->per_bfd->storage_obstack,
1337 sizeof (struct minimal_symbol)));
1338
1339 {
1340 struct minimal_symbol *m
1341 = &objfile->per_bfd->msymbols[objfile->per_bfd->minimal_symbol_count];
1342
1343 memset (m, 0, sizeof (*m));
1344 /* Don't rely on these enumeration values being 0's. */
1345 MSYMBOL_TYPE (m) = mst_unknown;
1346 MSYMBOL_SET_LANGUAGE (m, language_unknown,
1347 &objfile->per_bfd->storage_obstack);
1348 }
1349 }
1350
1351 /* Check if PC is in a shared library trampoline code stub.
1352 Return minimal symbol for the trampoline entry or NULL if PC is not
1353 in a trampoline code stub. */
1354
1355 static struct minimal_symbol *
1356 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
1357 {
1358 struct obj_section *section = find_pc_section (pc);
1359 struct bound_minimal_symbol msymbol;
1360
1361 if (section == NULL)
1362 return NULL;
1363 msymbol = lookup_minimal_symbol_by_pc_section_1 (pc, section, 1);
1364
1365 if (msymbol.minsym != NULL
1366 && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
1367 return msymbol.minsym;
1368 return NULL;
1369 }
1370
1371 /* If PC is in a shared library trampoline code stub, return the
1372 address of the `real' function belonging to the stub.
1373 Return 0 if PC is not in a trampoline code stub or if the real
1374 function is not found in the minimal symbol table.
1375
1376 We may fail to find the right function if a function with the
1377 same name is defined in more than one shared library, but this
1378 is considered bad programming style. We could return 0 if we find
1379 a duplicate function in case this matters someday. */
1380
1381 CORE_ADDR
1382 find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
1383 {
1384 struct objfile *objfile;
1385 struct minimal_symbol *msymbol;
1386 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1387
1388 if (tsymbol != NULL)
1389 {
1390 ALL_MSYMBOLS (objfile, msymbol)
1391 {
1392 if ((MSYMBOL_TYPE (msymbol) == mst_text
1393 || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc)
1394 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol),
1395 MSYMBOL_LINKAGE_NAME (tsymbol)) == 0)
1396 return MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
1397
1398 /* Also handle minimal symbols pointing to function descriptors. */
1399 if (MSYMBOL_TYPE (msymbol) == mst_data
1400 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol),
1401 MSYMBOL_LINKAGE_NAME (tsymbol)) == 0)
1402 {
1403 CORE_ADDR func;
1404
1405 func = gdbarch_convert_from_func_ptr_addr
1406 (get_objfile_arch (objfile),
1407 MSYMBOL_VALUE_ADDRESS (objfile, msymbol),
1408 &current_target);
1409
1410 /* Ignore data symbols that are not function descriptors. */
1411 if (func != MSYMBOL_VALUE_ADDRESS (objfile, msymbol))
1412 return func;
1413 }
1414 }
1415 }
1416 return 0;
1417 }
1418
1419 /* See minsyms.h. */
1420
1421 CORE_ADDR
1422 minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
1423 {
1424 int i;
1425 short section;
1426 struct obj_section *obj_section;
1427 CORE_ADDR result;
1428 struct minimal_symbol *msymbol;
1429
1430 gdb_assert (minsym.minsym != NULL);
1431
1432 /* If the minimal symbol has a size, use it. Otherwise use the
1433 lesser of the next minimal symbol in the same section, or the end
1434 of the section, as the end of the function. */
1435
1436 if (MSYMBOL_SIZE (minsym.minsym) != 0)
1437 return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
1438
1439 /* Step over other symbols at this same address, and symbols in
1440 other sections, to find the next symbol in this section with a
1441 different address. */
1442
1443 msymbol = minsym.minsym;
1444 section = MSYMBOL_SECTION (msymbol);
1445 for (i = 1; MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++)
1446 {
1447 if ((MSYMBOL_VALUE_RAW_ADDRESS (msymbol + i)
1448 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
1449 && MSYMBOL_SECTION (msymbol + i) == section)
1450 break;
1451 }
1452
1453 obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
1454 if (MSYMBOL_LINKAGE_NAME (msymbol + i) != NULL
1455 && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i)
1456 < obj_section_endaddr (obj_section)))
1457 result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, msymbol + i);
1458 else
1459 /* We got the start address from the last msymbol in the objfile.
1460 So the end address is the end of the section. */
1461 result = obj_section_endaddr (obj_section);
1462
1463 return result;
1464 }
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