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, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Contributed by Cygnus Support, using pieces from other GDB modules.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 /* This file contains support routines for creating, manipulating, and
24 destroying minimal symbol tables.
26 Minimal symbol tables are used to hold some very basic information about
27 all defined global symbols (text, data, bss, abs, etc). The only two
28 required pieces of information are the symbol's name and the address
29 associated with that symbol.
31 In many cases, even if a file was compiled with no special options for
32 debugging at all, as long as was not stripped it will contain sufficient
33 information to build useful minimal symbol tables using this structure.
35 Even when a file contains enough debugging information to build a full
36 symbol table, these minimal symbols are still useful for quickly mapping
37 between names and addresses, and vice versa. They are also sometimes used
38 to figure out what full symbol table entries need to be read in. */
43 #include "gdb_string.h"
46 #include "filenames.h"
53 #include "cp-support.h"
56 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
57 At the end, copy them all into one newly allocated location on an objfile's
60 #define BUNCH_SIZE 127
64 struct msym_bunch
*next
;
65 struct minimal_symbol contents
[BUNCH_SIZE
];
68 /* Bunch currently being filled up.
69 The next field points to chain of filled bunches. */
71 static struct msym_bunch
*msym_bunch
;
73 /* Number of slots filled in current bunch. */
75 static int msym_bunch_index
;
77 /* Total number of minimal symbols recorded so far for the objfile. */
79 static int msym_count
;
81 /* Compute a hash code based using the same criteria as `strcmp_iw'. */
84 msymbol_hash_iw (const char *string
)
86 unsigned int hash
= 0;
88 while (*string
&& *string
!= '(')
90 while (isspace (*string
))
92 if (*string
&& *string
!= '(')
94 hash
= SYMBOL_HASH_NEXT (hash
, *string
);
101 /* Compute a hash code for a string. */
104 msymbol_hash (const char *string
)
106 unsigned int hash
= 0;
108 for (; *string
; ++string
)
109 hash
= SYMBOL_HASH_NEXT (hash
, *string
);
113 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
115 add_minsym_to_hash_table (struct minimal_symbol
*sym
,
116 struct minimal_symbol
**table
)
118 if (sym
->hash_next
== NULL
)
121 = msymbol_hash (SYMBOL_LINKAGE_NAME (sym
)) % MINIMAL_SYMBOL_HASH_SIZE
;
123 sym
->hash_next
= table
[hash
];
128 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
131 add_minsym_to_demangled_hash_table (struct minimal_symbol
*sym
,
132 struct minimal_symbol
**table
)
134 if (sym
->demangled_hash_next
== NULL
)
136 unsigned int hash
= msymbol_hash_iw (SYMBOL_SEARCH_NAME (sym
))
137 % MINIMAL_SYMBOL_HASH_SIZE
;
139 sym
->demangled_hash_next
= table
[hash
];
145 /* Return OBJFILE where minimal symbol SYM is defined. */
147 msymbol_objfile (struct minimal_symbol
*sym
)
149 struct objfile
*objf
;
150 struct minimal_symbol
*tsym
;
153 = msymbol_hash (SYMBOL_LINKAGE_NAME (sym
)) % MINIMAL_SYMBOL_HASH_SIZE
;
155 for (objf
= object_files
; objf
; objf
= objf
->next
)
156 for (tsym
= objf
->msymbol_hash
[hash
]; tsym
; tsym
= tsym
->hash_next
)
160 /* We should always be able to find the objfile ... */
161 internal_error (__FILE__
, __LINE__
, _("failed internal consistency check"));
165 /* Look through all the current minimal symbol tables and find the
166 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
167 the search to that objfile. If SFILE is non-NULL, the only file-scope
168 symbols considered will be from that source file (global symbols are
169 still preferred). Returns a pointer to the minimal symbol that
170 matches, or NULL if no match is found.
172 Note: One instance where there may be duplicate minimal symbols with
173 the same name is when the symbol tables for a shared library and the
174 symbol tables for an executable contain global symbols with the same
175 names (the dynamic linker deals with the duplication).
177 It's also possible to have minimal symbols with different mangled
178 names, but identical demangled names. For example, the GNU C++ v3
179 ABI requires the generation of two (or perhaps three) copies of
180 constructor functions --- "in-charge", "not-in-charge", and
181 "allocate" copies; destructors may be duplicated as well.
182 Obviously, there must be distinct mangled names for each of these,
183 but the demangled names are all the same: S::S or S::~S. */
185 struct minimal_symbol
*
186 lookup_minimal_symbol (const char *name
, const char *sfile
,
187 struct objfile
*objf
)
189 struct objfile
*objfile
;
190 struct minimal_symbol
*msymbol
;
191 struct minimal_symbol
*found_symbol
= NULL
;
192 struct minimal_symbol
*found_file_symbol
= NULL
;
193 struct minimal_symbol
*trampoline_symbol
= NULL
;
195 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
196 unsigned int dem_hash
= msymbol_hash_iw (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
198 int needtofreename
= 0;
199 const char *modified_name
;
202 sfile
= lbasename (sfile
);
204 /* For C++, canonicalize the input name. */
205 modified_name
= name
;
206 if (current_language
->la_language
== language_cplus
)
208 char *cname
= cp_canonicalize_string (name
);
212 modified_name
= cname
;
217 for (objfile
= object_files
;
218 objfile
!= NULL
&& found_symbol
== NULL
;
219 objfile
= objfile
->next
)
221 if (objf
== NULL
|| objf
== objfile
222 || objf
== objfile
->separate_debug_objfile_backlink
)
224 /* Do two passes: the first over the ordinary hash table,
225 and the second over the demangled hash table. */
228 for (pass
= 1; pass
<= 2 && found_symbol
== NULL
; pass
++)
230 /* Select hash list according to pass. */
232 msymbol
= objfile
->msymbol_hash
[hash
];
234 msymbol
= objfile
->msymbol_demangled_hash
[dem_hash
];
236 while (msymbol
!= NULL
&& found_symbol
== NULL
)
242 int (*cmp
) (const char *, const char *);
244 cmp
= (case_sensitivity
== case_sensitive_on
245 ? strcmp
: strcasecmp
);
246 match
= cmp (SYMBOL_LINKAGE_NAME (msymbol
),
251 /* The function respects CASE_SENSITIVITY. */
252 match
= SYMBOL_MATCHES_SEARCH_NAME (msymbol
,
258 switch (MSYMBOL_TYPE (msymbol
))
264 || filename_cmp (msymbol
->filename
, sfile
) == 0)
265 found_file_symbol
= msymbol
;
268 case mst_solib_trampoline
:
270 /* If a trampoline symbol is found, we prefer to
271 keep looking for the *real* symbol. If the
272 actual symbol is not found, then we'll use the
274 if (trampoline_symbol
== NULL
)
275 trampoline_symbol
= msymbol
;
280 found_symbol
= msymbol
;
285 /* Find the next symbol on the hash chain. */
287 msymbol
= msymbol
->hash_next
;
289 msymbol
= msymbol
->demangled_hash_next
;
296 xfree ((void *) modified_name
);
298 /* External symbols are best. */
302 /* File-local symbols are next best. */
303 if (found_file_symbol
)
304 return found_file_symbol
;
306 /* Symbols for shared library trampolines are next best. */
307 if (trampoline_symbol
)
308 return trampoline_symbol
;
313 /* Look through all the current minimal symbol tables and find the
314 first minimal symbol that matches NAME and has text type. If OBJF
315 is non-NULL, limit the search to that objfile. Returns a pointer
316 to the minimal symbol that matches, or NULL if no match is found.
318 This function only searches the mangled (linkage) names. */
320 struct minimal_symbol
*
321 lookup_minimal_symbol_text (const char *name
, struct objfile
*objf
)
323 struct objfile
*objfile
;
324 struct minimal_symbol
*msymbol
;
325 struct minimal_symbol
*found_symbol
= NULL
;
326 struct minimal_symbol
*found_file_symbol
= NULL
;
328 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
330 for (objfile
= object_files
;
331 objfile
!= NULL
&& found_symbol
== NULL
;
332 objfile
= objfile
->next
)
334 if (objf
== NULL
|| objf
== objfile
335 || objf
== objfile
->separate_debug_objfile_backlink
)
337 for (msymbol
= objfile
->msymbol_hash
[hash
];
338 msymbol
!= NULL
&& found_symbol
== NULL
;
339 msymbol
= msymbol
->hash_next
)
341 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol
), name
) == 0 &&
342 (MSYMBOL_TYPE (msymbol
) == mst_text
343 || MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
344 || MSYMBOL_TYPE (msymbol
) == mst_file_text
))
346 switch (MSYMBOL_TYPE (msymbol
))
349 found_file_symbol
= msymbol
;
352 found_symbol
= msymbol
;
359 /* External symbols are best. */
363 /* File-local symbols are next best. */
364 if (found_file_symbol
)
365 return found_file_symbol
;
370 /* Look through all the current minimal symbol tables and find the
371 first minimal symbol that matches NAME and PC. If OBJF is non-NULL,
372 limit the search to that objfile. Returns a pointer to the minimal
373 symbol that matches, or NULL if no match is found. */
375 struct minimal_symbol
*
376 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc
, const char *name
,
377 struct objfile
*objf
)
379 struct objfile
*objfile
;
380 struct minimal_symbol
*msymbol
;
382 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
384 for (objfile
= object_files
;
386 objfile
= objfile
->next
)
388 if (objf
== NULL
|| objf
== objfile
389 || objf
== objfile
->separate_debug_objfile_backlink
)
391 for (msymbol
= objfile
->msymbol_hash
[hash
];
393 msymbol
= msymbol
->hash_next
)
395 if (SYMBOL_VALUE_ADDRESS (msymbol
) == pc
396 && strcmp (SYMBOL_LINKAGE_NAME (msymbol
), name
) == 0)
405 /* Look through all the current minimal symbol tables and find the
406 first minimal symbol that matches NAME and is a solib trampoline.
407 If OBJF is non-NULL, limit the search to that objfile. Returns a
408 pointer to the minimal symbol that matches, or NULL if no match is
411 This function only searches the mangled (linkage) names. */
413 struct minimal_symbol
*
414 lookup_minimal_symbol_solib_trampoline (const char *name
,
415 struct objfile
*objf
)
417 struct objfile
*objfile
;
418 struct minimal_symbol
*msymbol
;
419 struct minimal_symbol
*found_symbol
= NULL
;
421 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
423 for (objfile
= object_files
;
424 objfile
!= NULL
&& found_symbol
== NULL
;
425 objfile
= objfile
->next
)
427 if (objf
== NULL
|| objf
== objfile
428 || objf
== objfile
->separate_debug_objfile_backlink
)
430 for (msymbol
= objfile
->msymbol_hash
[hash
];
431 msymbol
!= NULL
&& found_symbol
== NULL
;
432 msymbol
= msymbol
->hash_next
)
434 if (strcmp (SYMBOL_LINKAGE_NAME (msymbol
), name
) == 0 &&
435 MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
444 /* Search through the minimal symbol table for each objfile and find
445 the symbol whose address is the largest address that is still less
446 than or equal to PC, and matches SECTION (which is not NULL).
447 Returns a pointer to the minimal symbol if such a symbol is found,
448 or NULL if PC is not in a suitable range.
449 Note that we need to look through ALL the minimal symbol tables
450 before deciding on the symbol that comes closest to the specified PC.
451 This is because objfiles can overlap, for example objfile A has .text
452 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
455 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
456 there are text and trampoline symbols at the same address.
457 Otherwise prefer mst_text symbols. */
459 static struct minimal_symbol
*
460 lookup_minimal_symbol_by_pc_section_1 (CORE_ADDR pc
,
461 struct obj_section
*section
,
467 struct objfile
*objfile
;
468 struct minimal_symbol
*msymbol
;
469 struct minimal_symbol
*best_symbol
= NULL
;
470 enum minimal_symbol_type want_type
, other_type
;
472 want_type
= want_trampoline
? mst_solib_trampoline
: mst_text
;
473 other_type
= want_trampoline
? mst_text
: mst_solib_trampoline
;
475 /* We can not require the symbol found to be in section, because
476 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
477 symbol - but find_pc_section won't return an absolute section and
478 hence the code below would skip over absolute symbols. We can
479 still take advantage of the call to find_pc_section, though - the
480 object file still must match. In case we have separate debug
481 files, search both the file and its separate debug file. There's
482 no telling which one will have the minimal symbols. */
484 gdb_assert (section
!= NULL
);
486 for (objfile
= section
->objfile
;
488 objfile
= objfile_separate_debug_iterate (section
->objfile
, objfile
))
490 /* If this objfile has a minimal symbol table, go search it using
491 a binary search. Note that a minimal symbol table always consists
492 of at least two symbols, a "real" symbol and the terminating
493 "null symbol". If there are no real symbols, then there is no
494 minimal symbol table at all. */
496 if (objfile
->minimal_symbol_count
> 0)
498 int best_zero_sized
= -1;
500 msymbol
= objfile
->msymbols
;
502 hi
= objfile
->minimal_symbol_count
- 1;
504 /* This code assumes that the minimal symbols are sorted by
505 ascending address values. If the pc value is greater than or
506 equal to the first symbol's address, then some symbol in this
507 minimal symbol table is a suitable candidate for being the
508 "best" symbol. This includes the last real symbol, for cases
509 where the pc value is larger than any address in this vector.
511 By iterating until the address associated with the current
512 hi index (the endpoint of the test interval) is less than
513 or equal to the desired pc value, we accomplish two things:
514 (1) the case where the pc value is larger than any minimal
515 symbol address is trivially solved, (2) the address associated
516 with the hi index is always the one we want when the interation
517 terminates. In essence, we are iterating the test interval
518 down until the pc value is pushed out of it from the high end.
520 Warning: this code is trickier than it would appear at first. */
522 /* Should also require that pc is <= end of objfile. FIXME! */
523 if (pc
>= SYMBOL_VALUE_ADDRESS (&msymbol
[lo
]))
525 while (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]) > pc
)
527 /* pc is still strictly less than highest address. */
528 /* Note "new" will always be >= lo. */
530 if ((SYMBOL_VALUE_ADDRESS (&msymbol
[new]) >= pc
) ||
541 /* If we have multiple symbols at the same address, we want
542 hi to point to the last one. That way we can find the
543 right symbol if it has an index greater than hi. */
544 while (hi
< objfile
->minimal_symbol_count
- 1
545 && (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
546 == SYMBOL_VALUE_ADDRESS (&msymbol
[hi
+ 1])))
549 /* Skip various undesirable symbols. */
552 /* Skip any absolute symbols. This is apparently
553 what adb and dbx do, and is needed for the CM-5.
554 There are two known possible problems: (1) on
555 ELF, apparently end, edata, etc. are absolute.
556 Not sure ignoring them here is a big deal, but if
557 we want to use them, the fix would go in
558 elfread.c. (2) I think shared library entry
559 points on the NeXT are absolute. If we want
560 special handling for this it probably should be
561 triggered by a special mst_abs_or_lib or some
564 if (MSYMBOL_TYPE (&msymbol
[hi
]) == mst_abs
)
570 /* If SECTION was specified, skip any symbol from
573 /* Some types of debug info, such as COFF,
574 don't fill the bfd_section member, so don't
575 throw away symbols on those platforms. */
576 && SYMBOL_OBJ_SECTION (&msymbol
[hi
]) != NULL
577 && (!matching_obj_sections
578 (SYMBOL_OBJ_SECTION (&msymbol
[hi
]), section
)))
584 /* If we are looking for a trampoline and this is a
585 text symbol, or the other way around, check the
586 preceding symbol too. If they are otherwise
587 identical prefer that one. */
589 && MSYMBOL_TYPE (&msymbol
[hi
]) == other_type
590 && MSYMBOL_TYPE (&msymbol
[hi
- 1]) == want_type
591 && (MSYMBOL_SIZE (&msymbol
[hi
])
592 == MSYMBOL_SIZE (&msymbol
[hi
- 1]))
593 && (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
594 == SYMBOL_VALUE_ADDRESS (&msymbol
[hi
- 1]))
595 && (SYMBOL_OBJ_SECTION (&msymbol
[hi
])
596 == SYMBOL_OBJ_SECTION (&msymbol
[hi
- 1])))
602 /* If the minimal symbol has a zero size, save it
603 but keep scanning backwards looking for one with
604 a non-zero size. A zero size may mean that the
605 symbol isn't an object or function (e.g. a
606 label), or it may just mean that the size was not
608 if (MSYMBOL_SIZE (&msymbol
[hi
]) == 0
609 && best_zero_sized
== -1)
611 best_zero_sized
= hi
;
616 /* If we are past the end of the current symbol, try
617 the previous symbol if it has a larger overlapping
618 size. This happens on i686-pc-linux-gnu with glibc;
619 the nocancel variants of system calls are inside
620 the cancellable variants, but both have sizes. */
622 && MSYMBOL_SIZE (&msymbol
[hi
]) != 0
623 && pc
>= (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
624 + MSYMBOL_SIZE (&msymbol
[hi
]))
625 && pc
< (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
- 1])
626 + MSYMBOL_SIZE (&msymbol
[hi
- 1])))
632 /* Otherwise, this symbol must be as good as we're going
637 /* If HI has a zero size, and best_zero_sized is set,
638 then we had two or more zero-sized symbols; prefer
639 the first one we found (which may have a higher
640 address). Also, if we ran off the end, be sure
642 if (best_zero_sized
!= -1
643 && (hi
< 0 || MSYMBOL_SIZE (&msymbol
[hi
]) == 0))
644 hi
= best_zero_sized
;
646 /* If the minimal symbol has a non-zero size, and this
647 PC appears to be outside the symbol's contents, then
648 refuse to use this symbol. If we found a zero-sized
649 symbol with an address greater than this symbol's,
650 use that instead. We assume that if symbols have
651 specified sizes, they do not overlap. */
654 && MSYMBOL_SIZE (&msymbol
[hi
]) != 0
655 && pc
>= (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
656 + MSYMBOL_SIZE (&msymbol
[hi
])))
658 if (best_zero_sized
!= -1)
659 hi
= best_zero_sized
;
661 /* Go on to the next object file. */
665 /* The minimal symbol indexed by hi now is the best one in this
666 objfile's minimal symbol table. See if it is the best one
670 && ((best_symbol
== NULL
) ||
671 (SYMBOL_VALUE_ADDRESS (best_symbol
) <
672 SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]))))
674 best_symbol
= &msymbol
[hi
];
679 return (best_symbol
);
682 struct minimal_symbol
*
683 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc
, struct obj_section
*section
)
687 /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
688 force the section but that (well unless you're doing overlay
689 debugging) always returns NULL making the call somewhat useless. */
690 section
= find_pc_section (pc
);
694 return lookup_minimal_symbol_by_pc_section_1 (pc
, section
, 0);
697 /* Backward compatibility: search through the minimal symbol table
698 for a matching PC (no section given). */
700 struct minimal_symbol
*
701 lookup_minimal_symbol_by_pc (CORE_ADDR pc
)
703 return lookup_minimal_symbol_by_pc_section (pc
, NULL
);
706 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
709 in_gnu_ifunc_stub (CORE_ADDR pc
)
711 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (pc
);
713 return msymbol
&& MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
;
716 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */
719 stub_gnu_ifunc_resolve_addr (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
721 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
722 "the ELF support compiled in."),
723 paddress (gdbarch
, pc
));
726 /* See elf_gnu_ifunc_resolve_name for its real implementation. */
729 stub_gnu_ifunc_resolve_name (const char *function_name
,
730 CORE_ADDR
*function_address_p
)
732 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
733 "the ELF support compiled in."),
737 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */
740 stub_gnu_ifunc_resolver_stop (struct breakpoint
*b
)
742 internal_error (__FILE__
, __LINE__
,
743 _("elf_gnu_ifunc_resolver_stop cannot be reached."));
746 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
749 stub_gnu_ifunc_resolver_return_stop (struct breakpoint
*b
)
751 internal_error (__FILE__
, __LINE__
,
752 _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
755 /* See elf_gnu_ifunc_fns for its real implementation. */
757 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns
=
759 stub_gnu_ifunc_resolve_addr
,
760 stub_gnu_ifunc_resolve_name
,
761 stub_gnu_ifunc_resolver_stop
,
762 stub_gnu_ifunc_resolver_return_stop
,
765 /* A placeholder for &elf_gnu_ifunc_fns. */
767 const struct gnu_ifunc_fns
*gnu_ifunc_fns_p
= &stub_gnu_ifunc_fns
;
769 /* Find the minimal symbol named NAME, and return both the minsym
770 struct and its objfile. This only checks the linkage name. Sets
771 *OBJFILE_P and returns the minimal symbol, if it is found. If it
772 is not found, returns NULL. */
774 struct minimal_symbol
*
775 lookup_minimal_symbol_and_objfile (const char *name
,
776 struct objfile
**objfile_p
)
778 struct objfile
*objfile
;
779 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
781 ALL_OBJFILES (objfile
)
783 struct minimal_symbol
*msym
;
785 for (msym
= objfile
->msymbol_hash
[hash
];
787 msym
= msym
->hash_next
)
789 if (strcmp (SYMBOL_LINKAGE_NAME (msym
), name
) == 0)
791 *objfile_p
= objfile
;
801 /* Return leading symbol character for a BFD. If BFD is NULL,
802 return the leading symbol character from the main objfile. */
804 static int get_symbol_leading_char (bfd
*);
807 get_symbol_leading_char (bfd
*abfd
)
810 return bfd_get_symbol_leading_char (abfd
);
811 if (symfile_objfile
!= NULL
&& symfile_objfile
->obfd
!= NULL
)
812 return bfd_get_symbol_leading_char (symfile_objfile
->obfd
);
816 /* Prepare to start collecting minimal symbols. Note that presetting
817 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
818 symbol to allocate the memory for the first bunch. */
821 init_minimal_symbol_collection (void)
825 msym_bunch_index
= BUNCH_SIZE
;
829 prim_record_minimal_symbol (const char *name
, CORE_ADDR address
,
830 enum minimal_symbol_type ms_type
,
831 struct objfile
*objfile
)
838 case mst_text_gnu_ifunc
:
840 case mst_solib_trampoline
:
841 section
= SECT_OFF_TEXT (objfile
);
845 section
= SECT_OFF_DATA (objfile
);
849 section
= SECT_OFF_BSS (objfile
);
855 prim_record_minimal_symbol_and_info (name
, address
, ms_type
,
856 section
, NULL
, objfile
);
859 /* Record a minimal symbol in the msym bunches. Returns the symbol
862 struct minimal_symbol
*
863 prim_record_minimal_symbol_full (const char *name
, int name_len
, int copy_name
,
865 enum minimal_symbol_type ms_type
,
867 asection
*bfd_section
,
868 struct objfile
*objfile
)
870 struct obj_section
*obj_section
;
871 struct msym_bunch
*new;
872 struct minimal_symbol
*msymbol
;
874 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
875 the minimal symbols, because if there is also another symbol
876 at the same address (e.g. the first function of the file),
877 lookup_minimal_symbol_by_pc would have no way of getting the
879 if (ms_type
== mst_file_text
&& name
[0] == 'g'
880 && (strcmp (name
, GCC_COMPILED_FLAG_SYMBOL
) == 0
881 || strcmp (name
, GCC2_COMPILED_FLAG_SYMBOL
) == 0))
884 /* It's safe to strip the leading char here once, since the name
885 is also stored stripped in the minimal symbol table. */
886 if (name
[0] == get_symbol_leading_char (objfile
->obfd
))
892 if (ms_type
== mst_file_text
&& strncmp (name
, "__gnu_compiled", 14) == 0)
895 if (msym_bunch_index
== BUNCH_SIZE
)
897 new = XCALLOC (1, struct msym_bunch
);
898 msym_bunch_index
= 0;
899 new->next
= msym_bunch
;
902 msymbol
= &msym_bunch
->contents
[msym_bunch_index
];
903 SYMBOL_SET_LANGUAGE (msymbol
, language_auto
);
904 SYMBOL_SET_NAMES (msymbol
, name
, name_len
, copy_name
, objfile
);
906 SYMBOL_VALUE_ADDRESS (msymbol
) = address
;
907 SYMBOL_SECTION (msymbol
) = section
;
908 SYMBOL_OBJ_SECTION (msymbol
) = NULL
;
910 /* Find obj_section corresponding to bfd_section. */
912 ALL_OBJFILE_OSECTIONS (objfile
, obj_section
)
914 if (obj_section
->the_bfd_section
== bfd_section
)
916 SYMBOL_OBJ_SECTION (msymbol
) = obj_section
;
921 MSYMBOL_TYPE (msymbol
) = ms_type
;
922 MSYMBOL_TARGET_FLAG_1 (msymbol
) = 0;
923 MSYMBOL_TARGET_FLAG_2 (msymbol
) = 0;
924 MSYMBOL_SIZE (msymbol
) = 0;
926 /* The hash pointers must be cleared! If they're not,
927 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
928 msymbol
->hash_next
= NULL
;
929 msymbol
->demangled_hash_next
= NULL
;
933 OBJSTAT (objfile
, n_minsyms
++);
937 /* Record a minimal symbol in the msym bunches. Returns the symbol
940 struct minimal_symbol
*
941 prim_record_minimal_symbol_and_info (const char *name
, CORE_ADDR address
,
942 enum minimal_symbol_type ms_type
,
944 asection
*bfd_section
,
945 struct objfile
*objfile
)
947 return prim_record_minimal_symbol_full (name
, strlen (name
), 1,
948 address
, ms_type
, section
,
949 bfd_section
, objfile
);
952 /* Compare two minimal symbols by address and return a signed result based
953 on unsigned comparisons, so that we sort into unsigned numeric order.
954 Within groups with the same address, sort by name. */
957 compare_minimal_symbols (const void *fn1p
, const void *fn2p
)
959 const struct minimal_symbol
*fn1
;
960 const struct minimal_symbol
*fn2
;
962 fn1
= (const struct minimal_symbol
*) fn1p
;
963 fn2
= (const struct minimal_symbol
*) fn2p
;
965 if (SYMBOL_VALUE_ADDRESS (fn1
) < SYMBOL_VALUE_ADDRESS (fn2
))
967 return (-1); /* addr 1 is less than addr 2. */
969 else if (SYMBOL_VALUE_ADDRESS (fn1
) > SYMBOL_VALUE_ADDRESS (fn2
))
971 return (1); /* addr 1 is greater than addr 2. */
974 /* addrs are equal: sort by name */
976 char *name1
= SYMBOL_LINKAGE_NAME (fn1
);
977 char *name2
= SYMBOL_LINKAGE_NAME (fn2
);
979 if (name1
&& name2
) /* both have names */
980 return strcmp (name1
, name2
);
982 return 1; /* fn1 has no name, so it is "less". */
983 else if (name1
) /* fn2 has no name, so it is "less". */
986 return (0); /* Neither has a name, so they're equal. */
990 /* Discard the currently collected minimal symbols, if any. If we wish
991 to save them for later use, we must have already copied them somewhere
992 else before calling this function.
994 FIXME: We could allocate the minimal symbol bunches on their own
995 obstack and then simply blow the obstack away when we are done with
996 it. Is it worth the extra trouble though? */
999 do_discard_minimal_symbols_cleanup (void *arg
)
1001 struct msym_bunch
*next
;
1003 while (msym_bunch
!= NULL
)
1005 next
= msym_bunch
->next
;
1012 make_cleanup_discard_minimal_symbols (void)
1014 return make_cleanup (do_discard_minimal_symbols_cleanup
, 0);
1019 /* Compact duplicate entries out of a minimal symbol table by walking
1020 through the table and compacting out entries with duplicate addresses
1021 and matching names. Return the number of entries remaining.
1023 On entry, the table resides between msymbol[0] and msymbol[mcount].
1024 On exit, it resides between msymbol[0] and msymbol[result_count].
1026 When files contain multiple sources of symbol information, it is
1027 possible for the minimal symbol table to contain many duplicate entries.
1028 As an example, SVR4 systems use ELF formatted object files, which
1029 usually contain at least two different types of symbol tables (a
1030 standard ELF one and a smaller dynamic linking table), as well as
1031 DWARF debugging information for files compiled with -g.
1033 Without compacting, the minimal symbol table for gdb itself contains
1034 over a 1000 duplicates, about a third of the total table size. Aside
1035 from the potential trap of not noticing that two successive entries
1036 identify the same location, this duplication impacts the time required
1037 to linearly scan the table, which is done in a number of places. So we
1038 just do one linear scan here and toss out the duplicates.
1040 Note that we are not concerned here about recovering the space that
1041 is potentially freed up, because the strings themselves are allocated
1042 on the objfile_obstack, and will get automatically freed when the symbol
1043 table is freed. The caller can free up the unused minimal symbols at
1044 the end of the compacted region if their allocation strategy allows it.
1046 Also note we only go up to the next to last entry within the loop
1047 and then copy the last entry explicitly after the loop terminates.
1049 Since the different sources of information for each symbol may
1050 have different levels of "completeness", we may have duplicates
1051 that have one entry with type "mst_unknown" and the other with a
1052 known type. So if the one we are leaving alone has type mst_unknown,
1053 overwrite its type with the type from the one we are compacting out. */
1056 compact_minimal_symbols (struct minimal_symbol
*msymbol
, int mcount
,
1057 struct objfile
*objfile
)
1059 struct minimal_symbol
*copyfrom
;
1060 struct minimal_symbol
*copyto
;
1064 copyfrom
= copyto
= msymbol
;
1065 while (copyfrom
< msymbol
+ mcount
- 1)
1067 if (SYMBOL_VALUE_ADDRESS (copyfrom
)
1068 == SYMBOL_VALUE_ADDRESS ((copyfrom
+ 1))
1069 && strcmp (SYMBOL_LINKAGE_NAME (copyfrom
),
1070 SYMBOL_LINKAGE_NAME ((copyfrom
+ 1))) == 0)
1072 if (MSYMBOL_TYPE ((copyfrom
+ 1)) == mst_unknown
)
1074 MSYMBOL_TYPE ((copyfrom
+ 1)) = MSYMBOL_TYPE (copyfrom
);
1079 *copyto
++ = *copyfrom
++;
1081 *copyto
++ = *copyfrom
++;
1082 mcount
= copyto
- msymbol
;
1087 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1088 after compacting or sorting the table since the entries move around
1089 thus causing the internal minimal_symbol pointers to become jumbled. */
1092 build_minimal_symbol_hash_tables (struct objfile
*objfile
)
1095 struct minimal_symbol
*msym
;
1097 /* Clear the hash tables. */
1098 for (i
= 0; i
< MINIMAL_SYMBOL_HASH_SIZE
; i
++)
1100 objfile
->msymbol_hash
[i
] = 0;
1101 objfile
->msymbol_demangled_hash
[i
] = 0;
1104 /* Now, (re)insert the actual entries. */
1105 for (i
= objfile
->minimal_symbol_count
, msym
= objfile
->msymbols
;
1109 msym
->hash_next
= 0;
1110 add_minsym_to_hash_table (msym
, objfile
->msymbol_hash
);
1112 msym
->demangled_hash_next
= 0;
1113 if (SYMBOL_SEARCH_NAME (msym
) != SYMBOL_LINKAGE_NAME (msym
))
1114 add_minsym_to_demangled_hash_table (msym
,
1115 objfile
->msymbol_demangled_hash
);
1119 /* Add the minimal symbols in the existing bunches to the objfile's official
1120 minimal symbol table. In most cases there is no minimal symbol table yet
1121 for this objfile, and the existing bunches are used to create one. Once
1122 in a while (for shared libraries for example), we add symbols (e.g. common
1123 symbols) to an existing objfile.
1125 Because of the way minimal symbols are collected, we generally have no way
1126 of knowing what source language applies to any particular minimal symbol.
1127 Specifically, we have no way of knowing if the minimal symbol comes from a
1128 C++ compilation unit or not. So for the sake of supporting cached
1129 demangled C++ names, we have no choice but to try and demangle each new one
1130 that comes in. If the demangling succeeds, then we assume it is a C++
1131 symbol and set the symbol's language and demangled name fields
1132 appropriately. Note that in order to avoid unnecessary demanglings, and
1133 allocating obstack space that subsequently can't be freed for the demangled
1134 names, we mark all newly added symbols with language_auto. After
1135 compaction of the minimal symbols, we go back and scan the entire minimal
1136 symbol table looking for these new symbols. For each new symbol we attempt
1137 to demangle it, and if successful, record it as a language_cplus symbol
1138 and cache the demangled form on the symbol obstack. Symbols which don't
1139 demangle are marked as language_unknown symbols, which inhibits future
1140 attempts to demangle them if we later add more minimal symbols. */
1143 install_minimal_symbols (struct objfile
*objfile
)
1147 struct msym_bunch
*bunch
;
1148 struct minimal_symbol
*msymbols
;
1153 /* Allocate enough space in the obstack, into which we will gather the
1154 bunches of new and existing minimal symbols, sort them, and then
1155 compact out the duplicate entries. Once we have a final table,
1156 we will give back the excess space. */
1158 alloc_count
= msym_count
+ objfile
->minimal_symbol_count
+ 1;
1159 obstack_blank (&objfile
->objfile_obstack
,
1160 alloc_count
* sizeof (struct minimal_symbol
));
1161 msymbols
= (struct minimal_symbol
*)
1162 obstack_base (&objfile
->objfile_obstack
);
1164 /* Copy in the existing minimal symbols, if there are any. */
1166 if (objfile
->minimal_symbol_count
)
1167 memcpy ((char *) msymbols
, (char *) objfile
->msymbols
,
1168 objfile
->minimal_symbol_count
* sizeof (struct minimal_symbol
));
1170 /* Walk through the list of minimal symbol bunches, adding each symbol
1171 to the new contiguous array of symbols. Note that we start with the
1172 current, possibly partially filled bunch (thus we use the current
1173 msym_bunch_index for the first bunch we copy over), and thereafter
1174 each bunch is full. */
1176 mcount
= objfile
->minimal_symbol_count
;
1178 for (bunch
= msym_bunch
; bunch
!= NULL
; bunch
= bunch
->next
)
1180 for (bindex
= 0; bindex
< msym_bunch_index
; bindex
++, mcount
++)
1181 msymbols
[mcount
] = bunch
->contents
[bindex
];
1182 msym_bunch_index
= BUNCH_SIZE
;
1185 /* Sort the minimal symbols by address. */
1187 qsort (msymbols
, mcount
, sizeof (struct minimal_symbol
),
1188 compare_minimal_symbols
);
1190 /* Compact out any duplicates, and free up whatever space we are
1193 mcount
= compact_minimal_symbols (msymbols
, mcount
, objfile
);
1195 obstack_blank (&objfile
->objfile_obstack
,
1196 (mcount
+ 1 - alloc_count
) * sizeof (struct minimal_symbol
));
1197 msymbols
= (struct minimal_symbol
*)
1198 obstack_finish (&objfile
->objfile_obstack
);
1200 /* We also terminate the minimal symbol table with a "null symbol",
1201 which is *not* included in the size of the table. This makes it
1202 easier to find the end of the table when we are handed a pointer
1203 to some symbol in the middle of it. Zero out the fields in the
1204 "null symbol" allocated at the end of the array. Note that the
1205 symbol count does *not* include this null symbol, which is why it
1206 is indexed by mcount and not mcount-1. */
1208 SYMBOL_LINKAGE_NAME (&msymbols
[mcount
]) = NULL
;
1209 SYMBOL_VALUE_ADDRESS (&msymbols
[mcount
]) = 0;
1210 MSYMBOL_TARGET_FLAG_1 (&msymbols
[mcount
]) = 0;
1211 MSYMBOL_TARGET_FLAG_2 (&msymbols
[mcount
]) = 0;
1212 MSYMBOL_SIZE (&msymbols
[mcount
]) = 0;
1213 MSYMBOL_TYPE (&msymbols
[mcount
]) = mst_unknown
;
1214 SYMBOL_SET_LANGUAGE (&msymbols
[mcount
], language_unknown
);
1216 /* Attach the minimal symbol table to the specified objfile.
1217 The strings themselves are also located in the objfile_obstack
1220 objfile
->minimal_symbol_count
= mcount
;
1221 objfile
->msymbols
= msymbols
;
1223 /* Try to guess the appropriate C++ ABI by looking at the names
1224 of the minimal symbols in the table. */
1228 for (i
= 0; i
< mcount
; i
++)
1230 /* If a symbol's name starts with _Z and was successfully
1231 demangled, then we can assume we've found a GNU v3 symbol.
1232 For now we set the C++ ABI globally; if the user is
1233 mixing ABIs then the user will need to "set cp-abi"
1235 const char *name
= SYMBOL_LINKAGE_NAME (&objfile
->msymbols
[i
]);
1237 if (name
[0] == '_' && name
[1] == 'Z'
1238 && SYMBOL_DEMANGLED_NAME (&objfile
->msymbols
[i
]) != NULL
)
1240 set_cp_abi_as_auto_default ("gnu-v3");
1246 /* Now build the hash tables; we can't do this incrementally
1247 at an earlier point since we weren't finished with the obstack
1248 yet. (And if the msymbol obstack gets moved, all the internal
1249 pointers to other msymbols need to be adjusted.) */
1250 build_minimal_symbol_hash_tables (objfile
);
1254 /* Sort all the minimal symbols in OBJFILE. */
1257 msymbols_sort (struct objfile
*objfile
)
1259 qsort (objfile
->msymbols
, objfile
->minimal_symbol_count
,
1260 sizeof (struct minimal_symbol
), compare_minimal_symbols
);
1261 build_minimal_symbol_hash_tables (objfile
);
1264 /* Check if PC is in a shared library trampoline code stub.
1265 Return minimal symbol for the trampoline entry or NULL if PC is not
1266 in a trampoline code stub. */
1268 struct minimal_symbol
*
1269 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc
)
1271 struct obj_section
*section
= find_pc_section (pc
);
1272 struct minimal_symbol
*msymbol
;
1274 if (section
== NULL
)
1276 msymbol
= lookup_minimal_symbol_by_pc_section_1 (pc
, section
, 1);
1278 if (msymbol
!= NULL
&& MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
1283 /* If PC is in a shared library trampoline code stub, return the
1284 address of the `real' function belonging to the stub.
1285 Return 0 if PC is not in a trampoline code stub or if the real
1286 function is not found in the minimal symbol table.
1288 We may fail to find the right function if a function with the
1289 same name is defined in more than one shared library, but this
1290 is considered bad programming style. We could return 0 if we find
1291 a duplicate function in case this matters someday. */
1294 find_solib_trampoline_target (struct frame_info
*frame
, CORE_ADDR pc
)
1296 struct objfile
*objfile
;
1297 struct minimal_symbol
*msymbol
;
1298 struct minimal_symbol
*tsymbol
= lookup_solib_trampoline_symbol_by_pc (pc
);
1300 if (tsymbol
!= NULL
)
1302 ALL_MSYMBOLS (objfile
, msymbol
)
1304 if ((MSYMBOL_TYPE (msymbol
) == mst_text
1305 || MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
)
1306 && strcmp (SYMBOL_LINKAGE_NAME (msymbol
),
1307 SYMBOL_LINKAGE_NAME (tsymbol
)) == 0)
1308 return SYMBOL_VALUE_ADDRESS (msymbol
);
1310 /* Also handle minimal symbols pointing to function descriptors. */
1311 if (MSYMBOL_TYPE (msymbol
) == mst_data
1312 && strcmp (SYMBOL_LINKAGE_NAME (msymbol
),
1313 SYMBOL_LINKAGE_NAME (tsymbol
)) == 0)
1317 func
= gdbarch_convert_from_func_ptr_addr
1318 (get_objfile_arch (objfile
),
1319 SYMBOL_VALUE_ADDRESS (msymbol
),
1322 /* Ignore data symbols that are not function descriptors. */
1323 if (func
!= SYMBOL_VALUE_ADDRESS (msymbol
))