1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Contributed by Cygnus Support, using pieces from other GDB modules.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
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.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 /* This file contains support routines for creating, manipulating, and
22 destroying minimal symbol tables.
24 Minimal symbol tables are used to hold some very basic information about
25 all defined global symbols (text, data, bss, abs, etc). The only two
26 required pieces of information are the symbol's name and the address
27 associated with that symbol.
29 In many cases, even if a file was compiled with no special options for
30 debugging at all, as long as was not stripped it will contain sufficient
31 information to build useful minimal symbol tables using this structure.
33 Even when a file contains enough debugging information to build a full
34 symbol table, these minimal symbols are still useful for quickly mapping
35 between names and addresses, and vice versa. They are also sometimes used
36 to figure out what full symbol table entries need to be read in. */
43 #include "filenames.h"
50 #include "cp-support.h"
52 #include "cli/cli-utils.h"
55 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
56 At the end, copy them all into one newly allocated location on an objfile's
57 per-BFD storage obstack. */
59 #define BUNCH_SIZE 127
63 struct msym_bunch
*next
;
64 struct minimal_symbol contents
[BUNCH_SIZE
];
67 /* Bunch currently being filled up.
68 The next field points to chain of filled bunches. */
70 static struct msym_bunch
*msym_bunch
;
72 /* Number of slots filled in current bunch. */
74 static int msym_bunch_index
;
76 /* Total number of minimal symbols recorded so far for the objfile. */
78 static int msym_count
;
83 msymbol_hash_iw (const char *string
)
85 unsigned int hash
= 0;
87 while (*string
&& *string
!= '(')
89 string
= skip_spaces_const (string
);
90 if (*string
&& *string
!= '(')
92 hash
= SYMBOL_HASH_NEXT (hash
, *string
);
102 msymbol_hash (const char *string
)
104 unsigned int hash
= 0;
106 for (; *string
; ++string
)
107 hash
= SYMBOL_HASH_NEXT (hash
, *string
);
111 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
113 add_minsym_to_hash_table (struct minimal_symbol
*sym
,
114 struct minimal_symbol
**table
)
116 if (sym
->hash_next
== NULL
)
119 = msymbol_hash (MSYMBOL_LINKAGE_NAME (sym
)) % MINIMAL_SYMBOL_HASH_SIZE
;
121 sym
->hash_next
= table
[hash
];
126 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
129 add_minsym_to_demangled_hash_table (struct minimal_symbol
*sym
,
130 struct minimal_symbol
**table
)
132 if (sym
->demangled_hash_next
== NULL
)
134 unsigned int hash
= msymbol_hash_iw (MSYMBOL_SEARCH_NAME (sym
))
135 % MINIMAL_SYMBOL_HASH_SIZE
;
137 sym
->demangled_hash_next
= table
[hash
];
142 /* Look through all the current minimal symbol tables and find the
143 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
144 the search to that objfile. If SFILE is non-NULL, the only file-scope
145 symbols considered will be from that source file (global symbols are
146 still preferred). Returns a pointer to the minimal symbol that
147 matches, or NULL if no match is found.
149 Note: One instance where there may be duplicate minimal symbols with
150 the same name is when the symbol tables for a shared library and the
151 symbol tables for an executable contain global symbols with the same
152 names (the dynamic linker deals with the duplication).
154 It's also possible to have minimal symbols with different mangled
155 names, but identical demangled names. For example, the GNU C++ v3
156 ABI requires the generation of two (or perhaps three) copies of
157 constructor functions --- "in-charge", "not-in-charge", and
158 "allocate" copies; destructors may be duplicated as well.
159 Obviously, there must be distinct mangled names for each of these,
160 but the demangled names are all the same: S::S or S::~S. */
162 struct bound_minimal_symbol
163 lookup_minimal_symbol (const char *name
, const char *sfile
,
164 struct objfile
*objf
)
166 struct objfile
*objfile
;
167 struct bound_minimal_symbol found_symbol
= { NULL
, NULL
};
168 struct bound_minimal_symbol found_file_symbol
= { NULL
, NULL
};
169 struct bound_minimal_symbol trampoline_symbol
= { NULL
, NULL
};
171 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
172 unsigned int dem_hash
= msymbol_hash_iw (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
174 int needtofreename
= 0;
175 const char *modified_name
;
178 sfile
= lbasename (sfile
);
180 /* For C++, canonicalize the input name. */
181 modified_name
= name
;
182 if (current_language
->la_language
== language_cplus
)
184 char *cname
= cp_canonicalize_string (name
);
188 modified_name
= cname
;
193 for (objfile
= object_files
;
194 objfile
!= NULL
&& found_symbol
.minsym
== NULL
;
195 objfile
= objfile
->next
)
197 struct minimal_symbol
*msymbol
;
199 if (objf
== NULL
|| objf
== objfile
200 || objf
== objfile
->separate_debug_objfile_backlink
)
202 /* Do two passes: the first over the ordinary hash table,
203 and the second over the demangled hash table. */
206 for (pass
= 1; pass
<= 2 && found_symbol
.minsym
== NULL
; pass
++)
208 /* Select hash list according to pass. */
210 msymbol
= objfile
->per_bfd
->msymbol_hash
[hash
];
212 msymbol
= objfile
->per_bfd
->msymbol_demangled_hash
[dem_hash
];
214 while (msymbol
!= NULL
&& found_symbol
.minsym
== NULL
)
220 int (*cmp
) (const char *, const char *);
222 cmp
= (case_sensitivity
== case_sensitive_on
223 ? strcmp
: strcasecmp
);
224 match
= cmp (MSYMBOL_LINKAGE_NAME (msymbol
),
229 /* The function respects CASE_SENSITIVITY. */
230 match
= MSYMBOL_MATCHES_SEARCH_NAME (msymbol
,
236 switch (MSYMBOL_TYPE (msymbol
))
242 || filename_cmp (msymbol
->filename
, sfile
) == 0)
244 found_file_symbol
.minsym
= msymbol
;
245 found_file_symbol
.objfile
= objfile
;
249 case mst_solib_trampoline
:
251 /* If a trampoline symbol is found, we prefer to
252 keep looking for the *real* symbol. If the
253 actual symbol is not found, then we'll use the
255 if (trampoline_symbol
.minsym
== NULL
)
257 trampoline_symbol
.minsym
= msymbol
;
258 trampoline_symbol
.objfile
= objfile
;
264 found_symbol
.minsym
= msymbol
;
265 found_symbol
.objfile
= objfile
;
270 /* Find the next symbol on the hash chain. */
272 msymbol
= msymbol
->hash_next
;
274 msymbol
= msymbol
->demangled_hash_next
;
281 xfree ((void *) modified_name
);
283 /* External symbols are best. */
284 if (found_symbol
.minsym
!= NULL
)
287 /* File-local symbols are next best. */
288 if (found_file_symbol
.minsym
!= NULL
)
289 return found_file_symbol
;
291 /* Symbols for shared library trampolines are next best. */
292 return trampoline_symbol
;
297 struct bound_minimal_symbol
298 lookup_bound_minimal_symbol (const char *name
)
300 return lookup_minimal_symbol (name
, NULL
, NULL
);
303 /* See common/symbol.h. */
306 find_minimal_symbol_address (const char *name
, CORE_ADDR
*addr
,
307 struct objfile
*objfile
)
309 struct bound_minimal_symbol sym
310 = lookup_minimal_symbol (name
, NULL
, objfile
);
312 if (sym
.minsym
!= NULL
)
313 *addr
= BMSYMBOL_VALUE_ADDRESS (sym
);
315 return sym
.minsym
== NULL
;
321 iterate_over_minimal_symbols (struct objfile
*objf
, const char *name
,
322 void (*callback
) (struct minimal_symbol
*,
327 struct minimal_symbol
*iter
;
328 int (*cmp
) (const char *, const char *);
330 /* The first pass is over the ordinary hash table. */
331 hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
332 iter
= objf
->per_bfd
->msymbol_hash
[hash
];
333 cmp
= (case_sensitivity
== case_sensitive_on
? strcmp
: strcasecmp
);
336 if (cmp (MSYMBOL_LINKAGE_NAME (iter
), name
) == 0)
337 (*callback
) (iter
, user_data
);
338 iter
= iter
->hash_next
;
341 /* The second pass is over the demangled table. */
342 hash
= msymbol_hash_iw (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
343 iter
= objf
->per_bfd
->msymbol_demangled_hash
[hash
];
346 if (MSYMBOL_MATCHES_SEARCH_NAME (iter
, name
))
347 (*callback
) (iter
, user_data
);
348 iter
= iter
->demangled_hash_next
;
354 struct bound_minimal_symbol
355 lookup_minimal_symbol_text (const char *name
, struct objfile
*objf
)
357 struct objfile
*objfile
;
358 struct minimal_symbol
*msymbol
;
359 struct bound_minimal_symbol found_symbol
= { NULL
, NULL
};
360 struct bound_minimal_symbol found_file_symbol
= { NULL
, NULL
};
362 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
364 for (objfile
= object_files
;
365 objfile
!= NULL
&& found_symbol
.minsym
== NULL
;
366 objfile
= objfile
->next
)
368 if (objf
== NULL
|| objf
== objfile
369 || objf
== objfile
->separate_debug_objfile_backlink
)
371 for (msymbol
= objfile
->per_bfd
->msymbol_hash
[hash
];
372 msymbol
!= NULL
&& found_symbol
.minsym
== NULL
;
373 msymbol
= msymbol
->hash_next
)
375 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol
), name
) == 0 &&
376 (MSYMBOL_TYPE (msymbol
) == mst_text
377 || MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
378 || MSYMBOL_TYPE (msymbol
) == mst_file_text
))
380 switch (MSYMBOL_TYPE (msymbol
))
383 found_file_symbol
.minsym
= msymbol
;
384 found_file_symbol
.objfile
= objfile
;
387 found_symbol
.minsym
= msymbol
;
388 found_symbol
.objfile
= objfile
;
395 /* External symbols are best. */
396 if (found_symbol
.minsym
)
399 /* File-local symbols are next best. */
400 return found_file_symbol
;
405 struct minimal_symbol
*
406 lookup_minimal_symbol_by_pc_name (CORE_ADDR pc
, const char *name
,
407 struct objfile
*objf
)
409 struct objfile
*objfile
;
410 struct minimal_symbol
*msymbol
;
412 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
414 for (objfile
= object_files
;
416 objfile
= objfile
->next
)
418 if (objf
== NULL
|| objf
== objfile
419 || objf
== objfile
->separate_debug_objfile_backlink
)
421 for (msymbol
= objfile
->per_bfd
->msymbol_hash
[hash
];
423 msymbol
= msymbol
->hash_next
)
425 if (MSYMBOL_VALUE_ADDRESS (objfile
, msymbol
) == pc
426 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol
), name
) == 0)
437 struct bound_minimal_symbol
438 lookup_minimal_symbol_solib_trampoline (const char *name
,
439 struct objfile
*objf
)
441 struct objfile
*objfile
;
442 struct minimal_symbol
*msymbol
;
443 struct bound_minimal_symbol found_symbol
= { NULL
, NULL
};
445 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
447 for (objfile
= object_files
;
449 objfile
= objfile
->next
)
451 if (objf
== NULL
|| objf
== objfile
452 || objf
== objfile
->separate_debug_objfile_backlink
)
454 for (msymbol
= objfile
->per_bfd
->msymbol_hash
[hash
];
456 msymbol
= msymbol
->hash_next
)
458 if (strcmp (MSYMBOL_LINKAGE_NAME (msymbol
), name
) == 0 &&
459 MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
461 found_symbol
.objfile
= objfile
;
462 found_symbol
.minsym
= msymbol
;
472 /* A helper function that makes *PC section-relative. This searches
473 the sections of OBJFILE and if *PC is in a section, it subtracts
474 the section offset and returns true. Otherwise it returns
478 frob_address (struct objfile
*objfile
, CORE_ADDR
*pc
)
480 struct obj_section
*iter
;
482 ALL_OBJFILE_OSECTIONS (objfile
, iter
)
484 if (*pc
>= obj_section_addr (iter
) && *pc
< obj_section_endaddr (iter
))
486 *pc
-= obj_section_offset (iter
);
494 /* Search through the minimal symbol table for each objfile and find
495 the symbol whose address is the largest address that is still less
496 than or equal to PC, and matches SECTION (which is not NULL).
497 Returns a pointer to the minimal symbol if such a symbol is found,
498 or NULL if PC is not in a suitable range.
499 Note that we need to look through ALL the minimal symbol tables
500 before deciding on the symbol that comes closest to the specified PC.
501 This is because objfiles can overlap, for example objfile A has .text
502 at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
505 If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
506 there are text and trampoline symbols at the same address.
507 Otherwise prefer mst_text symbols. */
509 static struct bound_minimal_symbol
510 lookup_minimal_symbol_by_pc_section_1 (CORE_ADDR pc_in
,
511 struct obj_section
*section
,
517 struct objfile
*objfile
;
518 struct minimal_symbol
*msymbol
;
519 struct minimal_symbol
*best_symbol
= NULL
;
520 struct objfile
*best_objfile
= NULL
;
521 struct bound_minimal_symbol result
;
522 enum minimal_symbol_type want_type
, other_type
;
524 want_type
= want_trampoline
? mst_solib_trampoline
: mst_text
;
525 other_type
= want_trampoline
? mst_text
: mst_solib_trampoline
;
527 /* We can not require the symbol found to be in section, because
528 e.g. IRIX 6.5 mdebug relies on this code returning an absolute
529 symbol - but find_pc_section won't return an absolute section and
530 hence the code below would skip over absolute symbols. We can
531 still take advantage of the call to find_pc_section, though - the
532 object file still must match. In case we have separate debug
533 files, search both the file and its separate debug file. There's
534 no telling which one will have the minimal symbols. */
536 gdb_assert (section
!= NULL
);
538 for (objfile
= section
->objfile
;
540 objfile
= objfile_separate_debug_iterate (section
->objfile
, objfile
))
542 CORE_ADDR pc
= pc_in
;
544 /* If this objfile has a minimal symbol table, go search it using
545 a binary search. Note that a minimal symbol table always consists
546 of at least two symbols, a "real" symbol and the terminating
547 "null symbol". If there are no real symbols, then there is no
548 minimal symbol table at all. */
550 if (objfile
->per_bfd
->minimal_symbol_count
> 0)
552 int best_zero_sized
= -1;
554 msymbol
= objfile
->per_bfd
->msymbols
;
556 hi
= objfile
->per_bfd
->minimal_symbol_count
- 1;
558 /* This code assumes that the minimal symbols are sorted by
559 ascending address values. If the pc value is greater than or
560 equal to the first symbol's address, then some symbol in this
561 minimal symbol table is a suitable candidate for being the
562 "best" symbol. This includes the last real symbol, for cases
563 where the pc value is larger than any address in this vector.
565 By iterating until the address associated with the current
566 hi index (the endpoint of the test interval) is less than
567 or equal to the desired pc value, we accomplish two things:
568 (1) the case where the pc value is larger than any minimal
569 symbol address is trivially solved, (2) the address associated
570 with the hi index is always the one we want when the interation
571 terminates. In essence, we are iterating the test interval
572 down until the pc value is pushed out of it from the high end.
574 Warning: this code is trickier than it would appear at first. */
576 if (frob_address (objfile
, &pc
)
577 && pc
>= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[lo
]))
579 while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
]) > pc
)
581 /* pc is still strictly less than highest address. */
582 /* Note "new" will always be >= lo. */
584 if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[new]) >= pc
)
595 /* If we have multiple symbols at the same address, we want
596 hi to point to the last one. That way we can find the
597 right symbol if it has an index greater than hi. */
598 while (hi
< objfile
->per_bfd
->minimal_symbol_count
- 1
599 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
])
600 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
+ 1])))
603 /* Skip various undesirable symbols. */
606 /* Skip any absolute symbols. This is apparently
607 what adb and dbx do, and is needed for the CM-5.
608 There are two known possible problems: (1) on
609 ELF, apparently end, edata, etc. are absolute.
610 Not sure ignoring them here is a big deal, but if
611 we want to use them, the fix would go in
612 elfread.c. (2) I think shared library entry
613 points on the NeXT are absolute. If we want
614 special handling for this it probably should be
615 triggered by a special mst_abs_or_lib or some
618 if (MSYMBOL_TYPE (&msymbol
[hi
]) == mst_abs
)
624 /* If SECTION was specified, skip any symbol from
627 /* Some types of debug info, such as COFF,
628 don't fill the bfd_section member, so don't
629 throw away symbols on those platforms. */
630 && MSYMBOL_OBJ_SECTION (objfile
, &msymbol
[hi
]) != NULL
631 && (!matching_obj_sections
632 (MSYMBOL_OBJ_SECTION (objfile
, &msymbol
[hi
]),
639 /* If we are looking for a trampoline and this is a
640 text symbol, or the other way around, check the
641 preceding symbol too. If they are otherwise
642 identical prefer that one. */
644 && MSYMBOL_TYPE (&msymbol
[hi
]) == other_type
645 && MSYMBOL_TYPE (&msymbol
[hi
- 1]) == want_type
646 && (MSYMBOL_SIZE (&msymbol
[hi
])
647 == MSYMBOL_SIZE (&msymbol
[hi
- 1]))
648 && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
])
649 == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
- 1]))
650 && (MSYMBOL_OBJ_SECTION (objfile
, &msymbol
[hi
])
651 == MSYMBOL_OBJ_SECTION (objfile
, &msymbol
[hi
- 1])))
657 /* If the minimal symbol has a zero size, save it
658 but keep scanning backwards looking for one with
659 a non-zero size. A zero size may mean that the
660 symbol isn't an object or function (e.g. a
661 label), or it may just mean that the size was not
663 if (MSYMBOL_SIZE (&msymbol
[hi
]) == 0
664 && best_zero_sized
== -1)
666 best_zero_sized
= hi
;
671 /* If we are past the end of the current symbol, try
672 the previous symbol if it has a larger overlapping
673 size. This happens on i686-pc-linux-gnu with glibc;
674 the nocancel variants of system calls are inside
675 the cancellable variants, but both have sizes. */
677 && MSYMBOL_SIZE (&msymbol
[hi
]) != 0
678 && pc
>= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
])
679 + MSYMBOL_SIZE (&msymbol
[hi
]))
680 && pc
< (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
- 1])
681 + MSYMBOL_SIZE (&msymbol
[hi
- 1])))
687 /* Otherwise, this symbol must be as good as we're going
692 /* If HI has a zero size, and best_zero_sized is set,
693 then we had two or more zero-sized symbols; prefer
694 the first one we found (which may have a higher
695 address). Also, if we ran off the end, be sure
697 if (best_zero_sized
!= -1
698 && (hi
< 0 || MSYMBOL_SIZE (&msymbol
[hi
]) == 0))
699 hi
= best_zero_sized
;
701 /* If the minimal symbol has a non-zero size, and this
702 PC appears to be outside the symbol's contents, then
703 refuse to use this symbol. If we found a zero-sized
704 symbol with an address greater than this symbol's,
705 use that instead. We assume that if symbols have
706 specified sizes, they do not overlap. */
709 && MSYMBOL_SIZE (&msymbol
[hi
]) != 0
710 && pc
>= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
])
711 + MSYMBOL_SIZE (&msymbol
[hi
])))
713 if (best_zero_sized
!= -1)
714 hi
= best_zero_sized
;
716 /* Go on to the next object file. */
720 /* The minimal symbol indexed by hi now is the best one in this
721 objfile's minimal symbol table. See if it is the best one
725 && ((best_symbol
== NULL
) ||
726 (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol
) <
727 MSYMBOL_VALUE_RAW_ADDRESS (&msymbol
[hi
]))))
729 best_symbol
= &msymbol
[hi
];
730 best_objfile
= objfile
;
736 result
.minsym
= best_symbol
;
737 result
.objfile
= best_objfile
;
741 struct bound_minimal_symbol
742 lookup_minimal_symbol_by_pc_section (CORE_ADDR pc
, struct obj_section
*section
)
746 /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
747 force the section but that (well unless you're doing overlay
748 debugging) always returns NULL making the call somewhat useless. */
749 section
= find_pc_section (pc
);
752 struct bound_minimal_symbol result
;
754 memset (&result
, 0, sizeof (result
));
758 return lookup_minimal_symbol_by_pc_section_1 (pc
, section
, 0);
763 struct bound_minimal_symbol
764 lookup_minimal_symbol_by_pc (CORE_ADDR pc
)
766 struct obj_section
*section
= find_pc_section (pc
);
770 struct bound_minimal_symbol result
;
772 memset (&result
, 0, sizeof (result
));
775 return lookup_minimal_symbol_by_pc_section_1 (pc
, section
, 0);
778 /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
781 in_gnu_ifunc_stub (CORE_ADDR pc
)
783 struct bound_minimal_symbol msymbol
= lookup_minimal_symbol_by_pc (pc
);
785 return msymbol
.minsym
&& MSYMBOL_TYPE (msymbol
.minsym
) == mst_text_gnu_ifunc
;
788 /* See elf_gnu_ifunc_resolve_addr for its real implementation. */
791 stub_gnu_ifunc_resolve_addr (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
793 error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
794 "the ELF support compiled in."),
795 paddress (gdbarch
, pc
));
798 /* See elf_gnu_ifunc_resolve_name for its real implementation. */
801 stub_gnu_ifunc_resolve_name (const char *function_name
,
802 CORE_ADDR
*function_address_p
)
804 error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
805 "the ELF support compiled in."),
809 /* See elf_gnu_ifunc_resolver_stop for its real implementation. */
812 stub_gnu_ifunc_resolver_stop (struct breakpoint
*b
)
814 internal_error (__FILE__
, __LINE__
,
815 _("elf_gnu_ifunc_resolver_stop cannot be reached."));
818 /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
821 stub_gnu_ifunc_resolver_return_stop (struct breakpoint
*b
)
823 internal_error (__FILE__
, __LINE__
,
824 _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
827 /* See elf_gnu_ifunc_fns for its real implementation. */
829 static const struct gnu_ifunc_fns stub_gnu_ifunc_fns
=
831 stub_gnu_ifunc_resolve_addr
,
832 stub_gnu_ifunc_resolve_name
,
833 stub_gnu_ifunc_resolver_stop
,
834 stub_gnu_ifunc_resolver_return_stop
,
837 /* A placeholder for &elf_gnu_ifunc_fns. */
839 const struct gnu_ifunc_fns
*gnu_ifunc_fns_p
= &stub_gnu_ifunc_fns
;
843 struct bound_minimal_symbol
844 lookup_minimal_symbol_and_objfile (const char *name
)
846 struct bound_minimal_symbol result
;
847 struct objfile
*objfile
;
848 unsigned int hash
= msymbol_hash (name
) % MINIMAL_SYMBOL_HASH_SIZE
;
850 ALL_OBJFILES (objfile
)
852 struct minimal_symbol
*msym
;
854 for (msym
= objfile
->per_bfd
->msymbol_hash
[hash
];
856 msym
= msym
->hash_next
)
858 if (strcmp (MSYMBOL_LINKAGE_NAME (msym
), name
) == 0)
860 result
.minsym
= msym
;
861 result
.objfile
= objfile
;
867 memset (&result
, 0, sizeof (result
));
872 /* Return leading symbol character for a BFD. If BFD is NULL,
873 return the leading symbol character from the main objfile. */
876 get_symbol_leading_char (bfd
*abfd
)
879 return bfd_get_symbol_leading_char (abfd
);
880 if (symfile_objfile
!= NULL
&& symfile_objfile
->obfd
!= NULL
)
881 return bfd_get_symbol_leading_char (symfile_objfile
->obfd
);
888 init_minimal_symbol_collection (void)
892 /* Note that presetting msym_bunch_index to BUNCH_SIZE causes the
893 first call to save a minimal symbol to allocate the memory for
895 msym_bunch_index
= BUNCH_SIZE
;
901 prim_record_minimal_symbol (const char *name
, CORE_ADDR address
,
902 enum minimal_symbol_type ms_type
,
903 struct objfile
*objfile
)
910 case mst_text_gnu_ifunc
:
912 case mst_solib_trampoline
:
913 section
= SECT_OFF_TEXT (objfile
);
917 section
= SECT_OFF_DATA (objfile
);
921 section
= SECT_OFF_BSS (objfile
);
927 prim_record_minimal_symbol_and_info (name
, address
, ms_type
,
933 struct minimal_symbol
*
934 prim_record_minimal_symbol_full (const char *name
, int name_len
, int copy_name
,
936 enum minimal_symbol_type ms_type
,
938 struct objfile
*objfile
)
940 struct obj_section
*obj_section
;
941 struct msym_bunch
*new;
942 struct minimal_symbol
*msymbol
;
944 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
945 the minimal symbols, because if there is also another symbol
946 at the same address (e.g. the first function of the file),
947 lookup_minimal_symbol_by_pc would have no way of getting the
949 if (ms_type
== mst_file_text
&& name
[0] == 'g'
950 && (strcmp (name
, GCC_COMPILED_FLAG_SYMBOL
) == 0
951 || strcmp (name
, GCC2_COMPILED_FLAG_SYMBOL
) == 0))
954 /* It's safe to strip the leading char here once, since the name
955 is also stored stripped in the minimal symbol table. */
956 if (name
[0] == get_symbol_leading_char (objfile
->obfd
))
962 if (ms_type
== mst_file_text
&& strncmp (name
, "__gnu_compiled", 14) == 0)
965 if (msym_bunch_index
== BUNCH_SIZE
)
967 new = XCNEW (struct msym_bunch
);
968 msym_bunch_index
= 0;
969 new->next
= msym_bunch
;
972 msymbol
= &msym_bunch
->contents
[msym_bunch_index
];
973 MSYMBOL_SET_LANGUAGE (msymbol
, language_auto
,
974 &objfile
->per_bfd
->storage_obstack
);
975 MSYMBOL_SET_NAMES (msymbol
, name
, name_len
, copy_name
, objfile
);
977 SET_MSYMBOL_VALUE_ADDRESS (msymbol
, address
);
978 MSYMBOL_SECTION (msymbol
) = section
;
980 MSYMBOL_TYPE (msymbol
) = ms_type
;
981 MSYMBOL_TARGET_FLAG_1 (msymbol
) = 0;
982 MSYMBOL_TARGET_FLAG_2 (msymbol
) = 0;
983 /* Do not use the SET_MSYMBOL_SIZE macro to initialize the size,
984 as it would also set the has_size flag. */
987 /* The hash pointers must be cleared! If they're not,
988 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
989 msymbol
->hash_next
= NULL
;
990 msymbol
->demangled_hash_next
= NULL
;
992 /* If we already read minimal symbols for this objfile, then don't
993 ever allocate a new one. */
994 if (!objfile
->per_bfd
->minsyms_read
)
997 objfile
->per_bfd
->n_minsyms
++;
1003 /* See minsyms.h. */
1005 struct minimal_symbol
*
1006 prim_record_minimal_symbol_and_info (const char *name
, CORE_ADDR address
,
1007 enum minimal_symbol_type ms_type
,
1009 struct objfile
*objfile
)
1011 return prim_record_minimal_symbol_full (name
, strlen (name
), 1,
1016 /* Compare two minimal symbols by address and return a signed result based
1017 on unsigned comparisons, so that we sort into unsigned numeric order.
1018 Within groups with the same address, sort by name. */
1021 compare_minimal_symbols (const void *fn1p
, const void *fn2p
)
1023 const struct minimal_symbol
*fn1
;
1024 const struct minimal_symbol
*fn2
;
1026 fn1
= (const struct minimal_symbol
*) fn1p
;
1027 fn2
= (const struct minimal_symbol
*) fn2p
;
1029 if (MSYMBOL_VALUE_RAW_ADDRESS (fn1
) < MSYMBOL_VALUE_RAW_ADDRESS (fn2
))
1031 return (-1); /* addr 1 is less than addr 2. */
1033 else if (MSYMBOL_VALUE_RAW_ADDRESS (fn1
) > MSYMBOL_VALUE_RAW_ADDRESS (fn2
))
1035 return (1); /* addr 1 is greater than addr 2. */
1038 /* addrs are equal: sort by name */
1040 const char *name1
= MSYMBOL_LINKAGE_NAME (fn1
);
1041 const char *name2
= MSYMBOL_LINKAGE_NAME (fn2
);
1043 if (name1
&& name2
) /* both have names */
1044 return strcmp (name1
, name2
);
1046 return 1; /* fn1 has no name, so it is "less". */
1047 else if (name1
) /* fn2 has no name, so it is "less". */
1050 return (0); /* Neither has a name, so they're equal. */
1054 /* Discard the currently collected minimal symbols, if any. If we wish
1055 to save them for later use, we must have already copied them somewhere
1056 else before calling this function.
1058 FIXME: We could allocate the minimal symbol bunches on their own
1059 obstack and then simply blow the obstack away when we are done with
1060 it. Is it worth the extra trouble though? */
1063 do_discard_minimal_symbols_cleanup (void *arg
)
1065 struct msym_bunch
*next
;
1067 while (msym_bunch
!= NULL
)
1069 next
= msym_bunch
->next
;
1075 /* See minsyms.h. */
1078 make_cleanup_discard_minimal_symbols (void)
1080 return make_cleanup (do_discard_minimal_symbols_cleanup
, 0);
1085 /* Compact duplicate entries out of a minimal symbol table by walking
1086 through the table and compacting out entries with duplicate addresses
1087 and matching names. Return the number of entries remaining.
1089 On entry, the table resides between msymbol[0] and msymbol[mcount].
1090 On exit, it resides between msymbol[0] and msymbol[result_count].
1092 When files contain multiple sources of symbol information, it is
1093 possible for the minimal symbol table to contain many duplicate entries.
1094 As an example, SVR4 systems use ELF formatted object files, which
1095 usually contain at least two different types of symbol tables (a
1096 standard ELF one and a smaller dynamic linking table), as well as
1097 DWARF debugging information for files compiled with -g.
1099 Without compacting, the minimal symbol table for gdb itself contains
1100 over a 1000 duplicates, about a third of the total table size. Aside
1101 from the potential trap of not noticing that two successive entries
1102 identify the same location, this duplication impacts the time required
1103 to linearly scan the table, which is done in a number of places. So we
1104 just do one linear scan here and toss out the duplicates.
1106 Note that we are not concerned here about recovering the space that
1107 is potentially freed up, because the strings themselves are allocated
1108 on the storage_obstack, and will get automatically freed when the symbol
1109 table is freed. The caller can free up the unused minimal symbols at
1110 the end of the compacted region if their allocation strategy allows it.
1112 Also note we only go up to the next to last entry within the loop
1113 and then copy the last entry explicitly after the loop terminates.
1115 Since the different sources of information for each symbol may
1116 have different levels of "completeness", we may have duplicates
1117 that have one entry with type "mst_unknown" and the other with a
1118 known type. So if the one we are leaving alone has type mst_unknown,
1119 overwrite its type with the type from the one we are compacting out. */
1122 compact_minimal_symbols (struct minimal_symbol
*msymbol
, int mcount
,
1123 struct objfile
*objfile
)
1125 struct minimal_symbol
*copyfrom
;
1126 struct minimal_symbol
*copyto
;
1130 copyfrom
= copyto
= msymbol
;
1131 while (copyfrom
< msymbol
+ mcount
- 1)
1133 if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom
)
1134 == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom
+ 1))
1135 && MSYMBOL_SECTION (copyfrom
) == MSYMBOL_SECTION (copyfrom
+ 1)
1136 && strcmp (MSYMBOL_LINKAGE_NAME (copyfrom
),
1137 MSYMBOL_LINKAGE_NAME ((copyfrom
+ 1))) == 0)
1139 if (MSYMBOL_TYPE ((copyfrom
+ 1)) == mst_unknown
)
1141 MSYMBOL_TYPE ((copyfrom
+ 1)) = MSYMBOL_TYPE (copyfrom
);
1146 *copyto
++ = *copyfrom
++;
1148 *copyto
++ = *copyfrom
++;
1149 mcount
= copyto
- msymbol
;
1154 /* Build (or rebuild) the minimal symbol hash tables. This is necessary
1155 after compacting or sorting the table since the entries move around
1156 thus causing the internal minimal_symbol pointers to become jumbled. */
1159 build_minimal_symbol_hash_tables (struct objfile
*objfile
)
1162 struct minimal_symbol
*msym
;
1164 /* Clear the hash tables. */
1165 for (i
= 0; i
< MINIMAL_SYMBOL_HASH_SIZE
; i
++)
1167 objfile
->per_bfd
->msymbol_hash
[i
] = 0;
1168 objfile
->per_bfd
->msymbol_demangled_hash
[i
] = 0;
1171 /* Now, (re)insert the actual entries. */
1172 for ((i
= objfile
->per_bfd
->minimal_symbol_count
,
1173 msym
= objfile
->per_bfd
->msymbols
);
1177 msym
->hash_next
= 0;
1178 add_minsym_to_hash_table (msym
, objfile
->per_bfd
->msymbol_hash
);
1180 msym
->demangled_hash_next
= 0;
1181 if (MSYMBOL_SEARCH_NAME (msym
) != MSYMBOL_LINKAGE_NAME (msym
))
1182 add_minsym_to_demangled_hash_table (msym
,
1183 objfile
->per_bfd
->msymbol_demangled_hash
);
1187 /* Add the minimal symbols in the existing bunches to the objfile's official
1188 minimal symbol table. In most cases there is no minimal symbol table yet
1189 for this objfile, and the existing bunches are used to create one. Once
1190 in a while (for shared libraries for example), we add symbols (e.g. common
1191 symbols) to an existing objfile.
1193 Because of the way minimal symbols are collected, we generally have no way
1194 of knowing what source language applies to any particular minimal symbol.
1195 Specifically, we have no way of knowing if the minimal symbol comes from a
1196 C++ compilation unit or not. So for the sake of supporting cached
1197 demangled C++ names, we have no choice but to try and demangle each new one
1198 that comes in. If the demangling succeeds, then we assume it is a C++
1199 symbol and set the symbol's language and demangled name fields
1200 appropriately. Note that in order to avoid unnecessary demanglings, and
1201 allocating obstack space that subsequently can't be freed for the demangled
1202 names, we mark all newly added symbols with language_auto. After
1203 compaction of the minimal symbols, we go back and scan the entire minimal
1204 symbol table looking for these new symbols. For each new symbol we attempt
1205 to demangle it, and if successful, record it as a language_cplus symbol
1206 and cache the demangled form on the symbol obstack. Symbols which don't
1207 demangle are marked as language_unknown symbols, which inhibits future
1208 attempts to demangle them if we later add more minimal symbols. */
1211 install_minimal_symbols (struct objfile
*objfile
)
1215 struct msym_bunch
*bunch
;
1216 struct minimal_symbol
*msymbols
;
1219 if (objfile
->per_bfd
->minsyms_read
)
1224 if (symtab_create_debug
)
1226 fprintf_unfiltered (gdb_stdlog
,
1227 "Installing %d minimal symbols of objfile %s.\n",
1228 msym_count
, objfile_name (objfile
));
1231 /* Allocate enough space in the obstack, into which we will gather the
1232 bunches of new and existing minimal symbols, sort them, and then
1233 compact out the duplicate entries. Once we have a final table,
1234 we will give back the excess space. */
1236 alloc_count
= msym_count
+ objfile
->per_bfd
->minimal_symbol_count
+ 1;
1237 obstack_blank (&objfile
->per_bfd
->storage_obstack
,
1238 alloc_count
* sizeof (struct minimal_symbol
));
1239 msymbols
= (struct minimal_symbol
*)
1240 obstack_base (&objfile
->per_bfd
->storage_obstack
);
1242 /* Copy in the existing minimal symbols, if there are any. */
1244 if (objfile
->per_bfd
->minimal_symbol_count
)
1245 memcpy ((char *) msymbols
, (char *) objfile
->per_bfd
->msymbols
,
1246 objfile
->per_bfd
->minimal_symbol_count
* sizeof (struct minimal_symbol
));
1248 /* Walk through the list of minimal symbol bunches, adding each symbol
1249 to the new contiguous array of symbols. Note that we start with the
1250 current, possibly partially filled bunch (thus we use the current
1251 msym_bunch_index for the first bunch we copy over), and thereafter
1252 each bunch is full. */
1254 mcount
= objfile
->per_bfd
->minimal_symbol_count
;
1256 for (bunch
= msym_bunch
; bunch
!= NULL
; bunch
= bunch
->next
)
1258 for (bindex
= 0; bindex
< msym_bunch_index
; bindex
++, mcount
++)
1259 msymbols
[mcount
] = bunch
->contents
[bindex
];
1260 msym_bunch_index
= BUNCH_SIZE
;
1263 /* Sort the minimal symbols by address. */
1265 qsort (msymbols
, mcount
, sizeof (struct minimal_symbol
),
1266 compare_minimal_symbols
);
1268 /* Compact out any duplicates, and free up whatever space we are
1271 mcount
= compact_minimal_symbols (msymbols
, mcount
, objfile
);
1273 obstack_blank (&objfile
->per_bfd
->storage_obstack
,
1274 (mcount
+ 1 - alloc_count
) * sizeof (struct minimal_symbol
));
1275 msymbols
= (struct minimal_symbol
*)
1276 obstack_finish (&objfile
->per_bfd
->storage_obstack
);
1278 /* We also terminate the minimal symbol table with a "null symbol",
1279 which is *not* included in the size of the table. This makes it
1280 easier to find the end of the table when we are handed a pointer
1281 to some symbol in the middle of it. Zero out the fields in the
1282 "null symbol" allocated at the end of the array. Note that the
1283 symbol count does *not* include this null symbol, which is why it
1284 is indexed by mcount and not mcount-1. */
1286 memset (&msymbols
[mcount
], 0, sizeof (struct minimal_symbol
));
1288 /* Attach the minimal symbol table to the specified objfile.
1289 The strings themselves are also located in the storage_obstack
1292 objfile
->per_bfd
->minimal_symbol_count
= mcount
;
1293 objfile
->per_bfd
->msymbols
= msymbols
;
1295 /* Now build the hash tables; we can't do this incrementally
1296 at an earlier point since we weren't finished with the obstack
1297 yet. (And if the msymbol obstack gets moved, all the internal
1298 pointers to other msymbols need to be adjusted.) */
1299 build_minimal_symbol_hash_tables (objfile
);
1303 /* See minsyms.h. */
1306 terminate_minimal_symbol_table (struct objfile
*objfile
)
1308 if (! objfile
->per_bfd
->msymbols
)
1309 objfile
->per_bfd
->msymbols
1310 = ((struct minimal_symbol
*)
1311 obstack_alloc (&objfile
->per_bfd
->storage_obstack
,
1312 sizeof (struct minimal_symbol
)));
1315 struct minimal_symbol
*m
1316 = &objfile
->per_bfd
->msymbols
[objfile
->per_bfd
->minimal_symbol_count
];
1318 memset (m
, 0, sizeof (*m
));
1319 /* Don't rely on these enumeration values being 0's. */
1320 MSYMBOL_TYPE (m
) = mst_unknown
;
1321 MSYMBOL_SET_LANGUAGE (m
, language_unknown
,
1322 &objfile
->per_bfd
->storage_obstack
);
1326 /* Check if PC is in a shared library trampoline code stub.
1327 Return minimal symbol for the trampoline entry or NULL if PC is not
1328 in a trampoline code stub. */
1330 static struct minimal_symbol
*
1331 lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc
)
1333 struct obj_section
*section
= find_pc_section (pc
);
1334 struct bound_minimal_symbol msymbol
;
1336 if (section
== NULL
)
1338 msymbol
= lookup_minimal_symbol_by_pc_section_1 (pc
, section
, 1);
1340 if (msymbol
.minsym
!= NULL
1341 && MSYMBOL_TYPE (msymbol
.minsym
) == mst_solib_trampoline
)
1342 return msymbol
.minsym
;
1346 /* If PC is in a shared library trampoline code stub, return the
1347 address of the `real' function belonging to the stub.
1348 Return 0 if PC is not in a trampoline code stub or if the real
1349 function is not found in the minimal symbol table.
1351 We may fail to find the right function if a function with the
1352 same name is defined in more than one shared library, but this
1353 is considered bad programming style. We could return 0 if we find
1354 a duplicate function in case this matters someday. */
1357 find_solib_trampoline_target (struct frame_info
*frame
, CORE_ADDR pc
)
1359 struct objfile
*objfile
;
1360 struct minimal_symbol
*msymbol
;
1361 struct minimal_symbol
*tsymbol
= lookup_solib_trampoline_symbol_by_pc (pc
);
1363 if (tsymbol
!= NULL
)
1365 ALL_MSYMBOLS (objfile
, msymbol
)
1367 if ((MSYMBOL_TYPE (msymbol
) == mst_text
1368 || MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
)
1369 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol
),
1370 MSYMBOL_LINKAGE_NAME (tsymbol
)) == 0)
1371 return MSYMBOL_VALUE_ADDRESS (objfile
, msymbol
);
1373 /* Also handle minimal symbols pointing to function descriptors. */
1374 if (MSYMBOL_TYPE (msymbol
) == mst_data
1375 && strcmp (MSYMBOL_LINKAGE_NAME (msymbol
),
1376 MSYMBOL_LINKAGE_NAME (tsymbol
)) == 0)
1380 func
= gdbarch_convert_from_func_ptr_addr
1381 (get_objfile_arch (objfile
),
1382 MSYMBOL_VALUE_ADDRESS (objfile
, msymbol
),
1385 /* Ignore data symbols that are not function descriptors. */
1386 if (func
!= MSYMBOL_VALUE_ADDRESS (objfile
, msymbol
))
1394 /* See minsyms.h. */
1397 minimal_symbol_upper_bound (struct bound_minimal_symbol minsym
)
1401 struct obj_section
*obj_section
;
1403 struct minimal_symbol
*msymbol
;
1405 gdb_assert (minsym
.minsym
!= NULL
);
1407 /* If the minimal symbol has a size, use it. Otherwise use the
1408 lesser of the next minimal symbol in the same section, or the end
1409 of the section, as the end of the function. */
1411 if (MSYMBOL_SIZE (minsym
.minsym
) != 0)
1412 return BMSYMBOL_VALUE_ADDRESS (minsym
) + MSYMBOL_SIZE (minsym
.minsym
);
1414 /* Step over other symbols at this same address, and symbols in
1415 other sections, to find the next symbol in this section with a
1416 different address. */
1418 msymbol
= minsym
.minsym
;
1419 section
= MSYMBOL_SECTION (msymbol
);
1420 for (i
= 1; MSYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
; i
++)
1422 if ((MSYMBOL_VALUE_RAW_ADDRESS (msymbol
+ i
)
1423 != MSYMBOL_VALUE_RAW_ADDRESS (msymbol
))
1424 && MSYMBOL_SECTION (msymbol
+ i
) == section
)
1428 obj_section
= MSYMBOL_OBJ_SECTION (minsym
.objfile
, minsym
.minsym
);
1429 if (MSYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
1430 && (MSYMBOL_VALUE_ADDRESS (minsym
.objfile
, msymbol
+ i
)
1431 < obj_section_endaddr (obj_section
)))
1432 result
= MSYMBOL_VALUE_ADDRESS (minsym
.objfile
, msymbol
+ i
);
1434 /* We got the start address from the last msymbol in the objfile.
1435 So the end address is the end of the section. */
1436 result
= obj_section_endaddr (obj_section
);