1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
3 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
4 Contributed by Cygnus Support, using pieces from other GDB modules.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file contains support routines for creating, manipulating, and
25 destroying minimal symbol tables.
27 Minimal symbol tables are used to hold some very basic information about
28 all defined global symbols (text, data, bss, abs, etc). The only two
29 required pieces of information are the symbol's name and the address
30 associated with that symbol.
32 In many cases, even if a file was compiled with no special options for
33 debugging at all, as long as was not stripped it will contain sufficient
34 information to build useful minimal symbol tables using this structure.
36 Even when a file contains enough debugging information to build a full
37 symbol table, these minimal symbols are still useful for quickly mapping
38 between names and addresses, and vice versa. They are also sometimes used
39 to figure out what full symbol table entries need to be read in. */
44 #include "gdb_string.h"
53 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
54 At the end, copy them all into one newly allocated location on an objfile's
57 #define BUNCH_SIZE 127
61 struct msym_bunch *next;
62 struct minimal_symbol contents[BUNCH_SIZE];
65 /* Bunch currently being filled up.
66 The next field points to chain of filled bunches. */
68 static struct msym_bunch *msym_bunch;
70 /* Number of slots filled in current bunch. */
72 static int msym_bunch_index;
74 /* Total number of minimal symbols recorded so far for the objfile. */
76 static int msym_count;
78 /* Compute a hash code based using the same criteria as `strcmp_iw'. */
81 msymbol_hash_iw (const char *string)
83 unsigned int hash = 0;
84 while (*string && *string != '(')
86 while (isspace (*string))
88 if (*string && *string != '(')
90 hash = hash * 67 + *string - 113;
97 /* Compute a hash code for a string. */
100 msymbol_hash (const char *string)
102 unsigned int hash = 0;
103 for (; *string; ++string)
104 hash = hash * 67 + *string - 113;
108 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
110 add_minsym_to_hash_table (struct minimal_symbol *sym,
111 struct minimal_symbol **table)
113 if (sym->hash_next == NULL)
116 = msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
117 sym->hash_next = table[hash];
122 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
125 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
126 struct minimal_symbol **table)
128 if (sym->demangled_hash_next == NULL)
130 unsigned int hash = msymbol_hash_iw (SYMBOL_DEMANGLED_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
131 sym->demangled_hash_next = table[hash];
137 /* Look through all the current minimal symbol tables and find the
138 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
139 the search to that objfile. If SFILE is non-NULL, the only file-scope
140 symbols considered will be from that source file (global symbols are
141 still preferred). Returns a pointer to the minimal symbol that
142 matches, or NULL if no match is found.
144 Note: One instance where there may be duplicate minimal symbols with
145 the same name is when the symbol tables for a shared library and the
146 symbol tables for an executable contain global symbols with the same
147 names (the dynamic linker deals with the duplication).
149 It's also possible to have minimal symbols with different mangled
150 names, but identical demangled names. For example, the GNU C++ v3
151 ABI requires the generation of two (or perhaps three) copies of
152 constructor functions --- "in-charge", "not-in-charge", and
153 "allocate" copies; destructors may be duplicated as well.
154 Obviously, there must be distinct mangled names for each of these,
155 but the demangled names are all the same: S::S or S::~S. */
157 struct minimal_symbol *
158 lookup_minimal_symbol (const char *name, const char *sfile,
159 struct objfile *objf)
161 struct objfile *objfile;
162 struct minimal_symbol *msymbol;
163 struct minimal_symbol *found_symbol = NULL;
164 struct minimal_symbol *found_file_symbol = NULL;
165 struct minimal_symbol *trampoline_symbol = NULL;
167 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
168 unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
170 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
173 char *p = strrchr (sfile, '/');
179 for (objfile = object_files;
180 objfile != NULL && found_symbol == NULL;
181 objfile = objfile->next)
183 if (objf == NULL || objf == objfile)
185 /* Do two passes: the first over the ordinary hash table,
186 and the second over the demangled hash table. */
189 for (pass = 1; pass <= 2 && found_symbol == NULL; pass++)
191 /* Select hash list according to pass. */
193 msymbol = objfile->msymbol_hash[hash];
195 msymbol = objfile->msymbol_demangled_hash[dem_hash];
197 while (msymbol != NULL && found_symbol == NULL)
199 /* FIXME: carlton/2003-02-27: This is an unholy
200 mixture of linkage names and natural names. If
201 you want to test the linkage names with strcmp,
202 do that. If you want to test the natural names
203 with strcmp_iw, use SYMBOL_MATCHES_NATURAL_NAME. */
204 if (strcmp (DEPRECATED_SYMBOL_NAME (msymbol), (name)) == 0
205 || (SYMBOL_DEMANGLED_NAME (msymbol) != NULL
206 && strcmp_iw (SYMBOL_DEMANGLED_NAME (msymbol),
209 switch (MSYMBOL_TYPE (msymbol))
214 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
216 || strcmp (msymbol->filename, sfile) == 0)
217 found_file_symbol = msymbol;
219 /* We have neither the ability nor the need to
220 deal with the SFILE parameter. If we find
221 more than one symbol, just return the latest
222 one (the user can't expect useful behavior in
224 found_file_symbol = msymbol;
228 case mst_solib_trampoline:
230 /* If a trampoline symbol is found, we prefer to
231 keep looking for the *real* symbol. If the
232 actual symbol is not found, then we'll use the
234 if (trampoline_symbol == NULL)
235 trampoline_symbol = msymbol;
240 found_symbol = msymbol;
245 /* Find the next symbol on the hash chain. */
247 msymbol = msymbol->hash_next;
249 msymbol = msymbol->demangled_hash_next;
254 /* External symbols are best. */
258 /* File-local symbols are next best. */
259 if (found_file_symbol)
260 return found_file_symbol;
262 /* Symbols for shared library trampolines are next best. */
263 if (trampoline_symbol)
264 return trampoline_symbol;
269 /* Look through all the current minimal symbol tables and find the
270 first minimal symbol that matches NAME and has text type. If OBJF
271 is non-NULL, limit the search to that objfile. Returns a pointer
272 to the minimal symbol that matches, or NULL if no match is found.
274 This function only searches the mangled (linkage) names. */
276 struct minimal_symbol *
277 lookup_minimal_symbol_text (const char *name, struct objfile *objf)
279 struct objfile *objfile;
280 struct minimal_symbol *msymbol;
281 struct minimal_symbol *found_symbol = NULL;
282 struct minimal_symbol *found_file_symbol = NULL;
284 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
286 for (objfile = object_files;
287 objfile != NULL && found_symbol == NULL;
288 objfile = objfile->next)
290 if (objf == NULL || objf == objfile)
292 for (msymbol = objfile->msymbol_hash[hash];
293 msymbol != NULL && found_symbol == NULL;
294 msymbol = msymbol->hash_next)
296 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
297 (MSYMBOL_TYPE (msymbol) == mst_text ||
298 MSYMBOL_TYPE (msymbol) == mst_file_text))
300 switch (MSYMBOL_TYPE (msymbol))
303 found_file_symbol = msymbol;
306 found_symbol = msymbol;
313 /* External symbols are best. */
317 /* File-local symbols are next best. */
318 if (found_file_symbol)
319 return found_file_symbol;
324 /* Look through all the current minimal symbol tables and find the
325 first minimal symbol that matches NAME and is a solib trampoline.
326 If OBJF is non-NULL, limit the search to that objfile. Returns a
327 pointer to the minimal symbol that matches, or NULL if no match is
330 This function only searches the mangled (linkage) names. */
332 struct minimal_symbol *
333 lookup_minimal_symbol_solib_trampoline (const char *name,
334 struct objfile *objf)
336 struct objfile *objfile;
337 struct minimal_symbol *msymbol;
338 struct minimal_symbol *found_symbol = NULL;
340 unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
342 for (objfile = object_files;
343 objfile != NULL && found_symbol == NULL;
344 objfile = objfile->next)
346 if (objf == NULL || objf == objfile)
348 for (msymbol = objfile->msymbol_hash[hash];
349 msymbol != NULL && found_symbol == NULL;
350 msymbol = msymbol->hash_next)
352 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
353 MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
362 /* Search through the minimal symbol table for each objfile and find
363 the symbol whose address is the largest address that is still less
364 than or equal to PC, and matches SECTION (if non-NULL). Returns a
365 pointer to the minimal symbol if such a symbol is found, or NULL if
366 PC is not in a suitable range. Note that we need to look through
367 ALL the minimal symbol tables before deciding on the symbol that
368 comes closest to the specified PC. This is because objfiles can
369 overlap, for example objfile A has .text at 0x100 and .data at
370 0x40000 and objfile B has .text at 0x234 and .data at 0x40048. */
372 struct minimal_symbol *
373 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, asection *section)
378 struct objfile *objfile;
379 struct minimal_symbol *msymbol;
380 struct minimal_symbol *best_symbol = NULL;
381 struct obj_section *pc_section;
383 /* PC has to be in a known section. This ensures that anything
384 beyond the end of the last segment doesn't appear to be part of
385 the last function in the last segment. */
386 pc_section = find_pc_section (pc);
387 if (pc_section == NULL)
390 /* NOTE: cagney/2004-01-27: Removed code (added 2003-07-19) that was
391 trying to force the PC into a valid section as returned by
392 find_pc_section. It broke IRIX 6.5 mdebug which relies on this
393 code returning an absolute symbol - the problem was that
394 find_pc_section wasn't returning an absolute section and hence
395 the code below would skip over absolute symbols. Since the
396 original problem was with finding a frame's function, and that
397 uses [indirectly] lookup_minimal_symbol_by_pc, the original
398 problem has been fixed by having that function use
401 for (objfile = object_files;
403 objfile = objfile->next)
405 /* If this objfile has a minimal symbol table, go search it using
406 a binary search. Note that a minimal symbol table always consists
407 of at least two symbols, a "real" symbol and the terminating
408 "null symbol". If there are no real symbols, then there is no
409 minimal symbol table at all. */
411 if (objfile->minimal_symbol_count > 0)
413 int best_zero_sized = -1;
415 msymbol = objfile->msymbols;
417 hi = objfile->minimal_symbol_count - 1;
419 /* This code assumes that the minimal symbols are sorted by
420 ascending address values. If the pc value is greater than or
421 equal to the first symbol's address, then some symbol in this
422 minimal symbol table is a suitable candidate for being the
423 "best" symbol. This includes the last real symbol, for cases
424 where the pc value is larger than any address in this vector.
426 By iterating until the address associated with the current
427 hi index (the endpoint of the test interval) is less than
428 or equal to the desired pc value, we accomplish two things:
429 (1) the case where the pc value is larger than any minimal
430 symbol address is trivially solved, (2) the address associated
431 with the hi index is always the one we want when the interation
432 terminates. In essence, we are iterating the test interval
433 down until the pc value is pushed out of it from the high end.
435 Warning: this code is trickier than it would appear at first. */
437 /* Should also require that pc is <= end of objfile. FIXME! */
438 if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo]))
440 while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc)
442 /* pc is still strictly less than highest address */
443 /* Note "new" will always be >= lo */
445 if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) ||
456 /* If we have multiple symbols at the same address, we want
457 hi to point to the last one. That way we can find the
458 right symbol if it has an index greater than hi. */
459 while (hi < objfile->minimal_symbol_count - 1
460 && (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
461 == SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1])))
464 /* Skip various undesirable symbols. */
467 /* Skip any absolute symbols. This is apparently
468 what adb and dbx do, and is needed for the CM-5.
469 There are two known possible problems: (1) on
470 ELF, apparently end, edata, etc. are absolute.
471 Not sure ignoring them here is a big deal, but if
472 we want to use them, the fix would go in
473 elfread.c. (2) I think shared library entry
474 points on the NeXT are absolute. If we want
475 special handling for this it probably should be
476 triggered by a special mst_abs_or_lib or some
479 if (msymbol[hi].type == mst_abs)
485 /* If SECTION was specified, skip any symbol from
488 /* Some types of debug info, such as COFF,
489 don't fill the bfd_section member, so don't
490 throw away symbols on those platforms. */
491 && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
492 && (!matching_bfd_sections
493 (SYMBOL_BFD_SECTION (&msymbol[hi]), section)))
499 /* If the minimal symbol has a zero size, save it
500 but keep scanning backwards looking for one with
501 a non-zero size. A zero size may mean that the
502 symbol isn't an object or function (e.g. a
503 label), or it may just mean that the size was not
505 if (MSYMBOL_SIZE (&msymbol[hi]) == 0
506 && best_zero_sized == -1)
508 best_zero_sized = hi;
513 /* Otherwise, this symbol must be as good as we're going
518 /* If HI has a zero size, and best_zero_sized is set,
519 then we had two or more zero-sized symbols; prefer
520 the first one we found (which may have a higher
521 address). Also, if we ran off the end, be sure
523 if (best_zero_sized != -1
524 && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
525 hi = best_zero_sized;
527 /* If the minimal symbol has a non-zero size, and this
528 PC appears to be outside the symbol's contents, then
529 refuse to use this symbol. If we found a zero-sized
530 symbol with an address greater than this symbol's,
531 use that instead. We assume that if symbols have
532 specified sizes, they do not overlap. */
535 && MSYMBOL_SIZE (&msymbol[hi]) != 0
536 && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
537 + MSYMBOL_SIZE (&msymbol[hi])))
539 if (best_zero_sized != -1)
540 hi = best_zero_sized;
542 /* Go on to the next object file. */
546 /* The minimal symbol indexed by hi now is the best one in this
547 objfile's minimal symbol table. See if it is the best one
551 && ((best_symbol == NULL) ||
552 (SYMBOL_VALUE_ADDRESS (best_symbol) <
553 SYMBOL_VALUE_ADDRESS (&msymbol[hi]))))
555 best_symbol = &msymbol[hi];
560 return (best_symbol);
563 /* Backward compatibility: search through the minimal symbol table
564 for a matching PC (no section given) */
566 struct minimal_symbol *
567 lookup_minimal_symbol_by_pc (CORE_ADDR pc)
569 /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
570 force the section but that (well unless you're doing overlay
571 debugging) always returns NULL making the call somewhat useless. */
572 struct obj_section *section = find_pc_section (pc);
575 return lookup_minimal_symbol_by_pc_section (pc, section->the_bfd_section);
579 /* Return leading symbol character for a BFD. If BFD is NULL,
580 return the leading symbol character from the main objfile. */
582 static int get_symbol_leading_char (bfd *);
585 get_symbol_leading_char (bfd *abfd)
588 return bfd_get_symbol_leading_char (abfd);
589 if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
590 return bfd_get_symbol_leading_char (symfile_objfile->obfd);
594 /* Prepare to start collecting minimal symbols. Note that presetting
595 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
596 symbol to allocate the memory for the first bunch. */
599 init_minimal_symbol_collection (void)
603 msym_bunch_index = BUNCH_SIZE;
607 prim_record_minimal_symbol (const char *name, CORE_ADDR address,
608 enum minimal_symbol_type ms_type,
609 struct objfile *objfile)
617 case mst_solib_trampoline:
618 section = SECT_OFF_TEXT (objfile);
622 section = SECT_OFF_DATA (objfile);
626 section = SECT_OFF_BSS (objfile);
632 prim_record_minimal_symbol_and_info (name, address, ms_type,
633 NULL, section, NULL, objfile);
636 /* Record a minimal symbol in the msym bunches. Returns the symbol
639 struct minimal_symbol *
640 prim_record_minimal_symbol_and_info (const char *name, CORE_ADDR address,
641 enum minimal_symbol_type ms_type,
642 char *info, int section,
643 asection *bfd_section,
644 struct objfile *objfile)
646 struct msym_bunch *new;
647 struct minimal_symbol *msymbol;
649 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
650 the minimal symbols, because if there is also another symbol
651 at the same address (e.g. the first function of the file),
652 lookup_minimal_symbol_by_pc would have no way of getting the
654 if (ms_type == mst_file_text && name[0] == 'g'
655 && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
656 || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
659 /* It's safe to strip the leading char here once, since the name
660 is also stored stripped in the minimal symbol table. */
661 if (name[0] == get_symbol_leading_char (objfile->obfd))
664 if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0)
667 if (msym_bunch_index == BUNCH_SIZE)
669 new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
670 msym_bunch_index = 0;
671 new->next = msym_bunch;
674 msymbol = &msym_bunch->contents[msym_bunch_index];
675 SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
676 SYMBOL_LANGUAGE (msymbol) = language_auto;
677 SYMBOL_SET_NAMES (msymbol, (char *)name, strlen (name), objfile);
679 SYMBOL_VALUE_ADDRESS (msymbol) = address;
680 SYMBOL_SECTION (msymbol) = section;
681 SYMBOL_BFD_SECTION (msymbol) = bfd_section;
683 MSYMBOL_TYPE (msymbol) = ms_type;
684 /* FIXME: This info, if it remains, needs its own field. */
685 MSYMBOL_INFO (msymbol) = info; /* FIXME! */
686 MSYMBOL_SIZE (msymbol) = 0;
688 /* The hash pointers must be cleared! If they're not,
689 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
690 msymbol->hash_next = NULL;
691 msymbol->demangled_hash_next = NULL;
695 OBJSTAT (objfile, n_minsyms++);
699 /* Compare two minimal symbols by address and return a signed result based
700 on unsigned comparisons, so that we sort into unsigned numeric order.
701 Within groups with the same address, sort by name. */
704 compare_minimal_symbols (const void *fn1p, const void *fn2p)
706 const struct minimal_symbol *fn1;
707 const struct minimal_symbol *fn2;
709 fn1 = (const struct minimal_symbol *) fn1p;
710 fn2 = (const struct minimal_symbol *) fn2p;
712 if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2))
714 return (-1); /* addr 1 is less than addr 2 */
716 else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2))
718 return (1); /* addr 1 is greater than addr 2 */
721 /* addrs are equal: sort by name */
723 char *name1 = SYMBOL_LINKAGE_NAME (fn1);
724 char *name2 = SYMBOL_LINKAGE_NAME (fn2);
726 if (name1 && name2) /* both have names */
727 return strcmp (name1, name2);
729 return 1; /* fn1 has no name, so it is "less" */
730 else if (name1) /* fn2 has no name, so it is "less" */
733 return (0); /* neither has a name, so they're equal. */
737 /* Discard the currently collected minimal symbols, if any. If we wish
738 to save them for later use, we must have already copied them somewhere
739 else before calling this function.
741 FIXME: We could allocate the minimal symbol bunches on their own
742 obstack and then simply blow the obstack away when we are done with
743 it. Is it worth the extra trouble though? */
746 do_discard_minimal_symbols_cleanup (void *arg)
748 struct msym_bunch *next;
750 while (msym_bunch != NULL)
752 next = msym_bunch->next;
759 make_cleanup_discard_minimal_symbols (void)
761 return make_cleanup (do_discard_minimal_symbols_cleanup, 0);
766 /* Compact duplicate entries out of a minimal symbol table by walking
767 through the table and compacting out entries with duplicate addresses
768 and matching names. Return the number of entries remaining.
770 On entry, the table resides between msymbol[0] and msymbol[mcount].
771 On exit, it resides between msymbol[0] and msymbol[result_count].
773 When files contain multiple sources of symbol information, it is
774 possible for the minimal symbol table to contain many duplicate entries.
775 As an example, SVR4 systems use ELF formatted object files, which
776 usually contain at least two different types of symbol tables (a
777 standard ELF one and a smaller dynamic linking table), as well as
778 DWARF debugging information for files compiled with -g.
780 Without compacting, the minimal symbol table for gdb itself contains
781 over a 1000 duplicates, about a third of the total table size. Aside
782 from the potential trap of not noticing that two successive entries
783 identify the same location, this duplication impacts the time required
784 to linearly scan the table, which is done in a number of places. So we
785 just do one linear scan here and toss out the duplicates.
787 Note that we are not concerned here about recovering the space that
788 is potentially freed up, because the strings themselves are allocated
789 on the objfile_obstack, and will get automatically freed when the symbol
790 table is freed. The caller can free up the unused minimal symbols at
791 the end of the compacted region if their allocation strategy allows it.
793 Also note we only go up to the next to last entry within the loop
794 and then copy the last entry explicitly after the loop terminates.
796 Since the different sources of information for each symbol may
797 have different levels of "completeness", we may have duplicates
798 that have one entry with type "mst_unknown" and the other with a
799 known type. So if the one we are leaving alone has type mst_unknown,
800 overwrite its type with the type from the one we are compacting out. */
803 compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
804 struct objfile *objfile)
806 struct minimal_symbol *copyfrom;
807 struct minimal_symbol *copyto;
811 copyfrom = copyto = msymbol;
812 while (copyfrom < msymbol + mcount - 1)
814 if (SYMBOL_VALUE_ADDRESS (copyfrom)
815 == SYMBOL_VALUE_ADDRESS ((copyfrom + 1))
816 && strcmp (SYMBOL_LINKAGE_NAME (copyfrom),
817 SYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0)
819 if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
821 MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
826 *copyto++ = *copyfrom++;
828 *copyto++ = *copyfrom++;
829 mcount = copyto - msymbol;
834 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
835 after compacting or sorting the table since the entries move around
836 thus causing the internal minimal_symbol pointers to become jumbled. */
839 build_minimal_symbol_hash_tables (struct objfile *objfile)
842 struct minimal_symbol *msym;
844 /* Clear the hash tables. */
845 for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
847 objfile->msymbol_hash[i] = 0;
848 objfile->msymbol_demangled_hash[i] = 0;
851 /* Now, (re)insert the actual entries. */
852 for (i = objfile->minimal_symbol_count, msym = objfile->msymbols;
857 add_minsym_to_hash_table (msym, objfile->msymbol_hash);
859 msym->demangled_hash_next = 0;
860 if (SYMBOL_SEARCH_NAME (msym) != SYMBOL_LINKAGE_NAME (msym))
861 add_minsym_to_demangled_hash_table (msym,
862 objfile->msymbol_demangled_hash);
866 /* Add the minimal symbols in the existing bunches to the objfile's official
867 minimal symbol table. In most cases there is no minimal symbol table yet
868 for this objfile, and the existing bunches are used to create one. Once
869 in a while (for shared libraries for example), we add symbols (e.g. common
870 symbols) to an existing objfile.
872 Because of the way minimal symbols are collected, we generally have no way
873 of knowing what source language applies to any particular minimal symbol.
874 Specifically, we have no way of knowing if the minimal symbol comes from a
875 C++ compilation unit or not. So for the sake of supporting cached
876 demangled C++ names, we have no choice but to try and demangle each new one
877 that comes in. If the demangling succeeds, then we assume it is a C++
878 symbol and set the symbol's language and demangled name fields
879 appropriately. Note that in order to avoid unnecessary demanglings, and
880 allocating obstack space that subsequently can't be freed for the demangled
881 names, we mark all newly added symbols with language_auto. After
882 compaction of the minimal symbols, we go back and scan the entire minimal
883 symbol table looking for these new symbols. For each new symbol we attempt
884 to demangle it, and if successful, record it as a language_cplus symbol
885 and cache the demangled form on the symbol obstack. Symbols which don't
886 demangle are marked as language_unknown symbols, which inhibits future
887 attempts to demangle them if we later add more minimal symbols. */
890 install_minimal_symbols (struct objfile *objfile)
894 struct msym_bunch *bunch;
895 struct minimal_symbol *msymbols;
900 /* Allocate enough space in the obstack, into which we will gather the
901 bunches of new and existing minimal symbols, sort them, and then
902 compact out the duplicate entries. Once we have a final table,
903 we will give back the excess space. */
905 alloc_count = msym_count + objfile->minimal_symbol_count + 1;
906 obstack_blank (&objfile->objfile_obstack,
907 alloc_count * sizeof (struct minimal_symbol));
908 msymbols = (struct minimal_symbol *)
909 obstack_base (&objfile->objfile_obstack);
911 /* Copy in the existing minimal symbols, if there are any. */
913 if (objfile->minimal_symbol_count)
914 memcpy ((char *) msymbols, (char *) objfile->msymbols,
915 objfile->minimal_symbol_count * sizeof (struct minimal_symbol));
917 /* Walk through the list of minimal symbol bunches, adding each symbol
918 to the new contiguous array of symbols. Note that we start with the
919 current, possibly partially filled bunch (thus we use the current
920 msym_bunch_index for the first bunch we copy over), and thereafter
921 each bunch is full. */
923 mcount = objfile->minimal_symbol_count;
925 for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
927 for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
928 msymbols[mcount] = bunch->contents[bindex];
929 msym_bunch_index = BUNCH_SIZE;
932 /* Sort the minimal symbols by address. */
934 qsort (msymbols, mcount, sizeof (struct minimal_symbol),
935 compare_minimal_symbols);
937 /* Compact out any duplicates, and free up whatever space we are
940 mcount = compact_minimal_symbols (msymbols, mcount, objfile);
942 obstack_blank (&objfile->objfile_obstack,
943 (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
944 msymbols = (struct minimal_symbol *)
945 obstack_finish (&objfile->objfile_obstack);
947 /* We also terminate the minimal symbol table with a "null symbol",
948 which is *not* included in the size of the table. This makes it
949 easier to find the end of the table when we are handed a pointer
950 to some symbol in the middle of it. Zero out the fields in the
951 "null symbol" allocated at the end of the array. Note that the
952 symbol count does *not* include this null symbol, which is why it
953 is indexed by mcount and not mcount-1. */
955 SYMBOL_LINKAGE_NAME (&msymbols[mcount]) = NULL;
956 SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0;
957 MSYMBOL_INFO (&msymbols[mcount]) = NULL;
958 MSYMBOL_SIZE (&msymbols[mcount]) = 0;
959 MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown;
960 SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown);
962 /* Attach the minimal symbol table to the specified objfile.
963 The strings themselves are also located in the objfile_obstack
966 objfile->minimal_symbol_count = mcount;
967 objfile->msymbols = msymbols;
969 /* Try to guess the appropriate C++ ABI by looking at the names
970 of the minimal symbols in the table. */
974 for (i = 0; i < mcount; i++)
976 /* If a symbol's name starts with _Z and was successfully
977 demangled, then we can assume we've found a GNU v3 symbol.
978 For now we set the C++ ABI globally; if the user is
979 mixing ABIs then the user will need to "set cp-abi"
981 const char *name = SYMBOL_LINKAGE_NAME (&objfile->msymbols[i]);
982 if (name[0] == '_' && name[1] == 'Z'
983 && SYMBOL_DEMANGLED_NAME (&objfile->msymbols[i]) != NULL)
985 set_cp_abi_as_auto_default ("gnu-v3");
991 /* Now build the hash tables; we can't do this incrementally
992 at an earlier point since we weren't finished with the obstack
993 yet. (And if the msymbol obstack gets moved, all the internal
994 pointers to other msymbols need to be adjusted.) */
995 build_minimal_symbol_hash_tables (objfile);
999 /* Sort all the minimal symbols in OBJFILE. */
1002 msymbols_sort (struct objfile *objfile)
1004 qsort (objfile->msymbols, objfile->minimal_symbol_count,
1005 sizeof (struct minimal_symbol), compare_minimal_symbols);
1006 build_minimal_symbol_hash_tables (objfile);
1009 /* Check if PC is in a shared library trampoline code stub.
1010 Return minimal symbol for the trampoline entry or NULL if PC is not
1011 in a trampoline code stub. */
1013 struct minimal_symbol *
1014 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
1016 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
1018 if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
1023 /* If PC is in a shared library trampoline code stub, return the
1024 address of the `real' function belonging to the stub.
1025 Return 0 if PC is not in a trampoline code stub or if the real
1026 function is not found in the minimal symbol table.
1028 We may fail to find the right function if a function with the
1029 same name is defined in more than one shared library, but this
1030 is considered bad programming style. We could return 0 if we find
1031 a duplicate function in case this matters someday. */
1034 find_solib_trampoline_target (CORE_ADDR pc)
1036 struct objfile *objfile;
1037 struct minimal_symbol *msymbol;
1038 struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
1040 if (tsymbol != NULL)
1042 ALL_MSYMBOLS (objfile, msymbol)
1044 if (MSYMBOL_TYPE (msymbol) == mst_text
1045 && strcmp (SYMBOL_LINKAGE_NAME (msymbol),
1046 SYMBOL_LINKAGE_NAME (tsymbol)) == 0)
1047 return SYMBOL_VALUE_ADDRESS (msymbol);