* objdump.c (compare_relocs): If relocation entries have the same address, keep them...
[deliverable/binutils-gdb.git] / gdb / minsyms.c
1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright 1992, 1993, 1994, 1995 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 2 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, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
20
21
22 /* This file contains support routines for creating, manipulating, and
23 destroying minimal symbol tables.
24
25 Minimal symbol tables are used to hold some very basic information about
26 all defined global symbols (text, data, bss, abs, etc). The only two
27 required pieces of information are the symbol's name and the address
28 associated with that symbol.
29
30 In many cases, even if a file was compiled with no special options for
31 debugging at all, as long as was not stripped it will contain sufficient
32 information to build useful minimal symbol tables using this structure.
33
34 Even when a file contains enough debugging information to build a full
35 symbol table, these minimal symbols are still useful for quickly mapping
36 between names and addresses, and vice versa. They are also sometimes used
37 to figure out what full symbol table entries need to be read in. */
38
39
40 #include "defs.h"
41 #include <string.h>
42 #include "symtab.h"
43 #include "bfd.h"
44 #include "symfile.h"
45 #include "objfiles.h"
46 #include "demangle.h"
47 #include "gdb-stabs.h"
48
49 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
50 At the end, copy them all into one newly allocated location on an objfile's
51 symbol obstack. */
52
53 #define BUNCH_SIZE 127
54
55 struct msym_bunch
56 {
57 struct msym_bunch *next;
58 struct minimal_symbol contents[BUNCH_SIZE];
59 };
60
61 /* Bunch currently being filled up.
62 The next field points to chain of filled bunches. */
63
64 static struct msym_bunch *msym_bunch;
65
66 /* Number of slots filled in current bunch. */
67
68 static int msym_bunch_index;
69
70 /* Total number of minimal symbols recorded so far for the objfile. */
71
72 static int msym_count;
73
74 /* Prototypes for local functions. */
75
76 static int
77 compare_minimal_symbols PARAMS ((const void *, const void *));
78
79 static int
80 compact_minimal_symbols PARAMS ((struct minimal_symbol *, int));
81
82 /* Look through all the current minimal symbol tables and find the
83 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
84 the search to that objfile. If SFILE is non-NULL, limit the search
85 to that source file. Returns a pointer to the minimal symbol that
86 matches, or NULL if no match is found.
87
88 Note: One instance where there may be duplicate minimal symbols with
89 the same name is when the symbol tables for a shared library and the
90 symbol tables for an executable contain global symbols with the same
91 names (the dynamic linker deals with the duplication). */
92
93 struct minimal_symbol *
94 lookup_minimal_symbol (name, sfile, objf)
95 register const char *name;
96 const char *sfile;
97 struct objfile *objf;
98 {
99 struct objfile *objfile;
100 struct minimal_symbol *msymbol;
101 struct minimal_symbol *found_symbol = NULL;
102 struct minimal_symbol *found_file_symbol = NULL;
103 struct minimal_symbol *trampoline_symbol = NULL;
104
105 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
106 if (sfile != NULL)
107 {
108 char *p = strrchr (sfile, '/');
109 if (p != NULL)
110 sfile = p + 1;
111 }
112 #endif
113
114 for (objfile = object_files;
115 objfile != NULL && found_symbol == NULL;
116 objfile = objfile -> next)
117 {
118 if (objf == NULL || objf == objfile)
119 {
120 for (msymbol = objfile -> msymbols;
121 msymbol != NULL && SYMBOL_NAME (msymbol) != NULL &&
122 found_symbol == NULL;
123 msymbol++)
124 {
125 if (SYMBOL_MATCHES_NAME (msymbol, name))
126 {
127 switch (MSYMBOL_TYPE (msymbol))
128 {
129 case mst_file_text:
130 case mst_file_data:
131 case mst_file_bss:
132 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
133 if (sfile == NULL || STREQ (msymbol->filename, sfile))
134 found_file_symbol = msymbol;
135 #else
136 /* We have neither the ability nor the need to
137 deal with the SFILE parameter. If we find
138 more than one symbol, just return the latest
139 one (the user can't expect useful behavior in
140 that case). */
141 found_file_symbol = msymbol;
142 #endif
143 break;
144
145 case mst_solib_trampoline:
146
147 /* If a trampoline symbol is found, we prefer to
148 keep looking for the *real* symbol. If the
149 actual symbol is not found, then we'll use the
150 trampoline entry. */
151 if (trampoline_symbol == NULL)
152 trampoline_symbol = msymbol;
153 break;
154
155 case mst_unknown:
156 default:
157 found_symbol = msymbol;
158 break;
159 }
160 }
161 }
162 }
163 }
164 /* External symbols are best. */
165 if (found_symbol)
166 return found_symbol;
167
168 /* File-local symbols are next best. */
169 if (found_file_symbol)
170 return found_file_symbol;
171
172 /* Symbols for shared library trampolines are next best. */
173 if (trampoline_symbol)
174 return trampoline_symbol;
175
176 return NULL;
177 }
178
179 /* Look through all the current minimal symbol tables and find the
180 first minimal symbol that matches NAME and of text type.
181 If OBJF is non-NULL, limit
182 the search to that objfile. If SFILE is non-NULL, limit the search
183 to that source file. Returns a pointer to the minimal symbol that
184 matches, or NULL if no match is found.
185 */
186
187 struct minimal_symbol *
188 lookup_minimal_symbol_text (name, sfile, objf)
189 register const char *name;
190 const char *sfile;
191 struct objfile *objf;
192 {
193 struct objfile *objfile;
194 struct minimal_symbol *msymbol;
195 struct minimal_symbol *found_symbol = NULL;
196 struct minimal_symbol *found_file_symbol = NULL;
197 struct minimal_symbol *trampoline_symbol = NULL;
198
199 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
200 if (sfile != NULL)
201 {
202 char *p = strrchr (sfile, '/');
203 if (p != NULL)
204 sfile = p + 1;
205 }
206 #endif
207
208 for (objfile = object_files;
209 objfile != NULL && found_symbol == NULL;
210 objfile = objfile -> next)
211 {
212 if (objf == NULL || objf == objfile)
213 {
214 for (msymbol = objfile -> msymbols;
215 msymbol != NULL && SYMBOL_NAME (msymbol) != NULL &&
216 found_symbol == NULL;
217 msymbol++)
218 {
219 if (SYMBOL_MATCHES_NAME (msymbol, name) &&
220 (MSYMBOL_TYPE (msymbol) == mst_text ||
221 MSYMBOL_TYPE (msymbol) == mst_file_text))
222 {
223 switch (MSYMBOL_TYPE (msymbol))
224 {
225 case mst_file_text:
226 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
227 if (sfile == NULL || STREQ (msymbol->filename, sfile))
228 found_file_symbol = msymbol;
229 #else
230 /* We have neither the ability nor the need to
231 deal with the SFILE parameter. If we find
232 more than one symbol, just return the latest
233 one (the user can't expect useful behavior in
234 that case). */
235 found_file_symbol = msymbol;
236 #endif
237 break;
238 default:
239 found_symbol = msymbol;
240 break;
241 }
242 }
243 }
244 }
245 }
246 /* External symbols are best. */
247 if (found_symbol)
248 return found_symbol;
249
250 /* File-local symbols are next best. */
251 if (found_file_symbol)
252 return found_file_symbol;
253
254 return NULL;
255 }
256
257
258 /* Search through the minimal symbol table for each objfile and find the
259 symbol whose address is the largest address that is still less than or
260 equal to PC. Returns a pointer to the minimal symbol if such a symbol
261 is found, or NULL if PC is not in a suitable range. Note that we need
262 to look through ALL the minimal symbol tables before deciding on the
263 symbol that comes closest to the specified PC. This is because objfiles
264 can overlap, for example objfile A has .text at 0x100 and .data at 0x40000
265 and objfile B has .text at 0x234 and .data at 0x40048. */
266
267 struct minimal_symbol *
268 lookup_minimal_symbol_by_pc (pc)
269 register CORE_ADDR pc;
270 {
271 register int lo;
272 register int hi;
273 register int new;
274 register struct objfile *objfile;
275 register struct minimal_symbol *msymbol;
276 register struct minimal_symbol *best_symbol = NULL;
277
278 for (objfile = object_files;
279 objfile != NULL;
280 objfile = objfile -> next)
281 {
282 /* If this objfile has a minimal symbol table, go search it using
283 a binary search. Note that a minimal symbol table always consists
284 of at least two symbols, a "real" symbol and the terminating
285 "null symbol". If there are no real symbols, then there is no
286 minimal symbol table at all. */
287
288 if ((msymbol = objfile -> msymbols) != NULL)
289 {
290 lo = 0;
291 hi = objfile -> minimal_symbol_count - 1;
292
293 /* This code assumes that the minimal symbols are sorted by
294 ascending address values. If the pc value is greater than or
295 equal to the first symbol's address, then some symbol in this
296 minimal symbol table is a suitable candidate for being the
297 "best" symbol. This includes the last real symbol, for cases
298 where the pc value is larger than any address in this vector.
299
300 By iterating until the address associated with the current
301 hi index (the endpoint of the test interval) is less than
302 or equal to the desired pc value, we accomplish two things:
303 (1) the case where the pc value is larger than any minimal
304 symbol address is trivially solved, (2) the address associated
305 with the hi index is always the one we want when the interation
306 terminates. In essence, we are iterating the test interval
307 down until the pc value is pushed out of it from the high end.
308
309 Warning: this code is trickier than it would appear at first. */
310
311 /* Should also requires that pc is <= end of objfile. FIXME! */
312 if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo]))
313 {
314 while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc)
315 {
316 /* pc is still strictly less than highest address */
317 /* Note "new" will always be >= lo */
318 new = (lo + hi) / 2;
319 if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) ||
320 (lo == new))
321 {
322 hi = new;
323 }
324 else
325 {
326 lo = new;
327 }
328 }
329 /* The minimal symbol indexed by hi now is the best one in this
330 objfile's minimal symbol table. See if it is the best one
331 overall. */
332
333 /* Skip any absolute symbols. This is apparently what adb
334 and dbx do, and is needed for the CM-5. There are two
335 known possible problems: (1) on ELF, apparently end, edata,
336 etc. are absolute. Not sure ignoring them here is a big
337 deal, but if we want to use them, the fix would go in
338 elfread.c. (2) I think shared library entry points on the
339 NeXT are absolute. If we want special handling for this
340 it probably should be triggered by a special
341 mst_abs_or_lib or some such. */
342 while (hi >= 0
343 && msymbol[hi].type == mst_abs)
344 --hi;
345
346 if (hi >= 0
347 && ((best_symbol == NULL) ||
348 (SYMBOL_VALUE_ADDRESS (best_symbol) <
349 SYMBOL_VALUE_ADDRESS (&msymbol[hi]))))
350 {
351 best_symbol = &msymbol[hi];
352 }
353 }
354 }
355 }
356 return (best_symbol);
357 }
358
359 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
360 CORE_ADDR
361 find_stab_function_addr (namestring, pst, objfile)
362 char *namestring;
363 struct partial_symtab *pst;
364 struct objfile *objfile;
365 {
366 struct minimal_symbol *msym;
367 char *p;
368 int n;
369
370 p = strchr (namestring, ':');
371 if (p == NULL)
372 p = namestring;
373 n = p - namestring;
374 p = alloca (n + 1);
375 strncpy (p, namestring, n);
376 p[n] = 0;
377
378 msym = lookup_minimal_symbol (p, pst->filename, objfile);
379 return msym == NULL ? 0 : SYMBOL_VALUE_ADDRESS (msym);
380 }
381 #endif /* SOFUN_ADDRESS_MAYBE_MISSING */
382
383 \f
384 /* Return leading symbol character for a BFD. If BFD is NULL,
385 return the leading symbol character from the main objfile. */
386
387 static int get_symbol_leading_char PARAMS ((bfd *));
388
389 static int
390 get_symbol_leading_char (abfd)
391 bfd * abfd;
392 {
393 if (abfd != NULL)
394 return bfd_get_symbol_leading_char (abfd);
395 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
396 return bfd_get_symbol_leading_char (symfile_objfile->obfd);
397 return 0;
398 }
399
400 /* Prepare to start collecting minimal symbols. Note that presetting
401 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
402 symbol to allocate the memory for the first bunch. */
403
404 void
405 init_minimal_symbol_collection ()
406 {
407 msym_count = 0;
408 msym_bunch = NULL;
409 msym_bunch_index = BUNCH_SIZE;
410 }
411
412 void
413 prim_record_minimal_symbol (name, address, ms_type, objfile)
414 const char *name;
415 CORE_ADDR address;
416 enum minimal_symbol_type ms_type;
417 struct objfile *objfile;
418 {
419 int section;
420
421 switch (ms_type)
422 {
423 case mst_text:
424 case mst_file_text:
425 case mst_solib_trampoline:
426 section = SECT_OFF_TEXT;
427 break;
428 case mst_data:
429 case mst_file_data:
430 section = SECT_OFF_DATA;
431 break;
432 case mst_bss:
433 case mst_file_bss:
434 section = SECT_OFF_BSS;
435 break;
436 default:
437 section = -1;
438 }
439
440 prim_record_minimal_symbol_and_info (name, address, ms_type,
441 NULL, section, objfile);
442 }
443
444 /* Record a minimal symbol in the msym bunches. Returns the symbol
445 newly created. */
446 struct minimal_symbol *
447 prim_record_minimal_symbol_and_info (name, address, ms_type, info, section,
448 objfile)
449 const char *name;
450 CORE_ADDR address;
451 enum minimal_symbol_type ms_type;
452 char *info;
453 int section;
454 struct objfile *objfile;
455 {
456 register struct msym_bunch *new;
457 register struct minimal_symbol *msymbol;
458
459 if (ms_type == mst_file_text)
460 {
461 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
462 the minimal symbols, because if there is also another symbol
463 at the same address (e.g. the first function of the file),
464 lookup_minimal_symbol_by_pc would have no way of getting the
465 right one. */
466 if (name[0] == 'g'
467 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
468 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
469 return;
470
471 {
472 const char *tempstring = name;
473 if (tempstring[0] == get_symbol_leading_char (objfile->obfd))
474 ++tempstring;
475 if (STREQN (tempstring, "__gnu_compiled", 14))
476 return;
477 }
478 }
479
480 if (msym_bunch_index == BUNCH_SIZE)
481 {
482 new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
483 msym_bunch_index = 0;
484 new -> next = msym_bunch;
485 msym_bunch = new;
486 }
487 msymbol = &msym_bunch -> contents[msym_bunch_index];
488 SYMBOL_NAME (msymbol) = (char *) name;
489 SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
490 SYMBOL_VALUE_ADDRESS (msymbol) = address;
491 SYMBOL_SECTION (msymbol) = section;
492
493 MSYMBOL_TYPE (msymbol) = ms_type;
494 /* FIXME: This info, if it remains, needs its own field. */
495 MSYMBOL_INFO (msymbol) = info; /* FIXME! */
496 msym_bunch_index++;
497 msym_count++;
498 return msymbol;
499 }
500
501 /* Compare two minimal symbols by address and return a signed result based
502 on unsigned comparisons, so that we sort into unsigned numeric order. */
503
504 static int
505 compare_minimal_symbols (fn1p, fn2p)
506 const PTR fn1p;
507 const PTR fn2p;
508 {
509 register const struct minimal_symbol *fn1;
510 register const struct minimal_symbol *fn2;
511
512 fn1 = (const struct minimal_symbol *) fn1p;
513 fn2 = (const struct minimal_symbol *) fn2p;
514
515 if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2))
516 {
517 return (-1);
518 }
519 else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2))
520 {
521 return (1);
522 }
523 else
524 {
525 return (0);
526 }
527 }
528
529 /* Discard the currently collected minimal symbols, if any. If we wish
530 to save them for later use, we must have already copied them somewhere
531 else before calling this function.
532
533 FIXME: We could allocate the minimal symbol bunches on their own
534 obstack and then simply blow the obstack away when we are done with
535 it. Is it worth the extra trouble though? */
536
537 /* ARGSUSED */
538 void
539 discard_minimal_symbols (foo)
540 int foo;
541 {
542 register struct msym_bunch *next;
543
544 while (msym_bunch != NULL)
545 {
546 next = msym_bunch -> next;
547 free ((PTR)msym_bunch);
548 msym_bunch = next;
549 }
550 }
551
552 /* Compact duplicate entries out of a minimal symbol table by walking
553 through the table and compacting out entries with duplicate addresses
554 and matching names. Return the number of entries remaining.
555
556 On entry, the table resides between msymbol[0] and msymbol[mcount].
557 On exit, it resides between msymbol[0] and msymbol[result_count].
558
559 When files contain multiple sources of symbol information, it is
560 possible for the minimal symbol table to contain many duplicate entries.
561 As an example, SVR4 systems use ELF formatted object files, which
562 usually contain at least two different types of symbol tables (a
563 standard ELF one and a smaller dynamic linking table), as well as
564 DWARF debugging information for files compiled with -g.
565
566 Without compacting, the minimal symbol table for gdb itself contains
567 over a 1000 duplicates, about a third of the total table size. Aside
568 from the potential trap of not noticing that two successive entries
569 identify the same location, this duplication impacts the time required
570 to linearly scan the table, which is done in a number of places. So we
571 just do one linear scan here and toss out the duplicates.
572
573 Note that we are not concerned here about recovering the space that
574 is potentially freed up, because the strings themselves are allocated
575 on the symbol_obstack, and will get automatically freed when the symbol
576 table is freed. The caller can free up the unused minimal symbols at
577 the end of the compacted region if their allocation strategy allows it.
578
579 Also note we only go up to the next to last entry within the loop
580 and then copy the last entry explicitly after the loop terminates.
581
582 Since the different sources of information for each symbol may
583 have different levels of "completeness", we may have duplicates
584 that have one entry with type "mst_unknown" and the other with a
585 known type. So if the one we are leaving alone has type mst_unknown,
586 overwrite its type with the type from the one we are compacting out. */
587
588 static int
589 compact_minimal_symbols (msymbol, mcount)
590 struct minimal_symbol *msymbol;
591 int mcount;
592 {
593 struct minimal_symbol *copyfrom;
594 struct minimal_symbol *copyto;
595
596 if (mcount > 0)
597 {
598 copyfrom = copyto = msymbol;
599 while (copyfrom < msymbol + mcount - 1)
600 {
601 if (SYMBOL_VALUE_ADDRESS (copyfrom) ==
602 SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) &&
603 (STREQ (SYMBOL_NAME (copyfrom), SYMBOL_NAME ((copyfrom + 1)))))
604 {
605 if (MSYMBOL_TYPE((copyfrom + 1)) == mst_unknown)
606 {
607 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
608 }
609 copyfrom++;
610 }
611 else
612 {
613 *copyto++ = *copyfrom++;
614 }
615 }
616 *copyto++ = *copyfrom++;
617 mcount = copyto - msymbol;
618 }
619 return (mcount);
620 }
621
622 /* Add the minimal symbols in the existing bunches to the objfile's official
623 minimal symbol table. In most cases there is no minimal symbol table yet
624 for this objfile, and the existing bunches are used to create one. Once
625 in a while (for shared libraries for example), we add symbols (e.g. common
626 symbols) to an existing objfile.
627
628 Because of the way minimal symbols are collected, we generally have no way
629 of knowing what source language applies to any particular minimal symbol.
630 Specifically, we have no way of knowing if the minimal symbol comes from a
631 C++ compilation unit or not. So for the sake of supporting cached
632 demangled C++ names, we have no choice but to try and demangle each new one
633 that comes in. If the demangling succeeds, then we assume it is a C++
634 symbol and set the symbol's language and demangled name fields
635 appropriately. Note that in order to avoid unnecessary demanglings, and
636 allocating obstack space that subsequently can't be freed for the demangled
637 names, we mark all newly added symbols with language_auto. After
638 compaction of the minimal symbols, we go back and scan the entire minimal
639 symbol table looking for these new symbols. For each new symbol we attempt
640 to demangle it, and if successful, record it as a language_cplus symbol
641 and cache the demangled form on the symbol obstack. Symbols which don't
642 demangle are marked as language_unknown symbols, which inhibits future
643 attempts to demangle them if we later add more minimal symbols. */
644
645 void
646 install_minimal_symbols (objfile)
647 struct objfile *objfile;
648 {
649 register int bindex;
650 register int mcount;
651 register struct msym_bunch *bunch;
652 register struct minimal_symbol *msymbols;
653 int alloc_count;
654 register char leading_char;
655
656 if (msym_count > 0)
657 {
658 /* Allocate enough space in the obstack, into which we will gather the
659 bunches of new and existing minimal symbols, sort them, and then
660 compact out the duplicate entries. Once we have a final table,
661 we will give back the excess space. */
662
663 alloc_count = msym_count + objfile->minimal_symbol_count + 1;
664 obstack_blank (&objfile->symbol_obstack,
665 alloc_count * sizeof (struct minimal_symbol));
666 msymbols = (struct minimal_symbol *)
667 obstack_base (&objfile->symbol_obstack);
668
669 /* Copy in the existing minimal symbols, if there are any. */
670
671 if (objfile->minimal_symbol_count)
672 memcpy ((char *)msymbols, (char *)objfile->msymbols,
673 objfile->minimal_symbol_count * sizeof (struct minimal_symbol));
674
675 /* Walk through the list of minimal symbol bunches, adding each symbol
676 to the new contiguous array of symbols. Note that we start with the
677 current, possibly partially filled bunch (thus we use the current
678 msym_bunch_index for the first bunch we copy over), and thereafter
679 each bunch is full. */
680
681 mcount = objfile->minimal_symbol_count;
682 leading_char = get_symbol_leading_char (objfile->obfd);
683
684 for (bunch = msym_bunch; bunch != NULL; bunch = bunch -> next)
685 {
686 for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
687 {
688 msymbols[mcount] = bunch -> contents[bindex];
689 SYMBOL_LANGUAGE (&msymbols[mcount]) = language_auto;
690 if (SYMBOL_NAME (&msymbols[mcount])[0] == leading_char)
691 {
692 SYMBOL_NAME(&msymbols[mcount])++;
693 }
694 }
695 msym_bunch_index = BUNCH_SIZE;
696 }
697
698 /* Sort the minimal symbols by address. */
699
700 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
701 compare_minimal_symbols);
702
703 /* Compact out any duplicates, and free up whatever space we are
704 no longer using. */
705
706 mcount = compact_minimal_symbols (msymbols, mcount);
707
708 obstack_blank (&objfile->symbol_obstack,
709 (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
710 msymbols = (struct minimal_symbol *)
711 obstack_finish (&objfile->symbol_obstack);
712
713 /* We also terminate the minimal symbol table with a "null symbol",
714 which is *not* included in the size of the table. This makes it
715 easier to find the end of the table when we are handed a pointer
716 to some symbol in the middle of it. Zero out the fields in the
717 "null symbol" allocated at the end of the array. Note that the
718 symbol count does *not* include this null symbol, which is why it
719 is indexed by mcount and not mcount-1. */
720
721 SYMBOL_NAME (&msymbols[mcount]) = NULL;
722 SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0;
723 MSYMBOL_INFO (&msymbols[mcount]) = NULL;
724 MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown;
725 SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown);
726
727 /* Attach the minimal symbol table to the specified objfile.
728 The strings themselves are also located in the symbol_obstack
729 of this objfile. */
730
731 objfile -> minimal_symbol_count = mcount;
732 objfile -> msymbols = msymbols;
733
734 /* Now walk through all the minimal symbols, selecting the newly added
735 ones and attempting to cache their C++ demangled names. */
736
737 for ( ; mcount-- > 0 ; msymbols++)
738 {
739 SYMBOL_INIT_DEMANGLED_NAME (msymbols, &objfile->symbol_obstack);
740 }
741 }
742 }
743
744 /* Sort all the minimal symbols in OBJFILE. */
745
746 void
747 msymbols_sort (objfile)
748 struct objfile *objfile;
749 {
750 qsort (objfile->msymbols, objfile->minimal_symbol_count,
751 sizeof (struct minimal_symbol), compare_minimal_symbols);
752 }
753
754 /* Check if PC is in a shared library trampoline code stub.
755 Return minimal symbol for the trampoline entry or NULL if PC is not
756 in a trampoline code stub. */
757
758 struct minimal_symbol *
759 lookup_solib_trampoline_symbol_by_pc (pc)
760 CORE_ADDR pc;
761 {
762 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
763
764 if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
765 return msymbol;
766 return NULL;
767 }
768
769 /* If PC is in a shared library trampoline code stub, return the
770 address of the `real' function belonging to the stub.
771 Return 0 if PC is not in a trampoline code stub or if the real
772 function is not found in the minimal symbol table.
773
774 We may fail to find the right function if a function with the
775 same name is defined in more than one shared library, but this
776 is considered bad programming style. We could return 0 if we find
777 a duplicate function in case this matters someday. */
778
779 CORE_ADDR
780 find_solib_trampoline_target (pc)
781 CORE_ADDR pc;
782 {
783 struct objfile *objfile;
784 struct minimal_symbol *msymbol;
785 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
786
787 if (tsymbol != NULL)
788 {
789 ALL_MSYMBOLS (objfile, msymbol)
790 {
791 if (MSYMBOL_TYPE (msymbol) == mst_text
792 && STREQ (SYMBOL_NAME (msymbol), SYMBOL_NAME (tsymbol)))
793 return SYMBOL_VALUE_ADDRESS (msymbol);
794 }
795 }
796 return 0;
797 }
798
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