1 /* GDB routines for manipulating the minimal symbol tables.
2 Copyright 1992, 93, 94, 96, 97, 1998 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 2 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, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
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"
49 #include "gdb-stabs.h"
51 /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
52 At the end, copy them all into one newly allocated location on an objfile's
55 #define BUNCH_SIZE 127
59 struct msym_bunch
*next
;
60 struct minimal_symbol contents
[BUNCH_SIZE
];
63 /* Bunch currently being filled up.
64 The next field points to chain of filled bunches. */
66 static struct msym_bunch
*msym_bunch
;
68 /* Number of slots filled in current bunch. */
70 static int msym_bunch_index
;
72 /* Total number of minimal symbols recorded so far for the objfile. */
74 static int msym_count
;
76 /* Prototypes for local functions. */
79 compare_minimal_symbols
PARAMS ((const void *, const void *));
82 compact_minimal_symbols
PARAMS ((struct minimal_symbol
*, int,
85 static void add_minsym_to_demangled_hash_table (struct minimal_symbol
*sym
,
86 struct minimal_symbol
**table
);
88 /* Compute a hash code based using the same criteria as `strcmp_iw'. */
91 msymbol_hash_iw (const char *string
)
93 unsigned int hash
= 0;
94 while (*string
&& *string
!= '(')
96 while (isspace (*string
))
98 if (*string
&& *string
!= '(')
99 hash
= (31 * hash
) + *string
;
102 return hash
% MINIMAL_SYMBOL_HASH_SIZE
;
105 /* Compute a hash code for a string. */
108 msymbol_hash (const char *string
)
110 unsigned int hash
= 0;
111 for (; *string
; ++string
)
112 hash
= (31 * hash
) + *string
;
113 return hash
% MINIMAL_SYMBOL_HASH_SIZE
;
116 /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
118 add_minsym_to_hash_table (struct minimal_symbol
*sym
,
119 struct minimal_symbol
**table
)
121 if (sym
->hash_next
== NULL
)
123 unsigned int hash
= msymbol_hash (SYMBOL_NAME (sym
));
124 sym
->hash_next
= table
[hash
];
129 /* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
132 add_minsym_to_demangled_hash_table (struct minimal_symbol
*sym
,
133 struct minimal_symbol
**table
)
135 if (sym
->demangled_hash_next
== NULL
)
137 unsigned int hash
= msymbol_hash_iw (SYMBOL_DEMANGLED_NAME (sym
));
138 sym
->demangled_hash_next
= table
[hash
];
144 /* Look through all the current minimal symbol tables and find the
145 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
146 the search to that objfile. If SFILE is non-NULL, limit the search
147 to that source file. Returns a pointer to the minimal symbol that
148 matches, or NULL if no match is found.
150 Note: One instance where there may be duplicate minimal symbols with
151 the same name is when the symbol tables for a shared library and the
152 symbol tables for an executable contain global symbols with the same
153 names (the dynamic linker deals with the duplication). */
155 struct minimal_symbol
*
156 lookup_minimal_symbol (name
, sfile
, objf
)
157 register const char *name
;
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
);
168 unsigned int dem_hash
= msymbol_hash_iw (name
);
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 if (SYMBOL_MATCHES_NAME (msymbol
, name
))
201 switch (MSYMBOL_TYPE (msymbol
))
206 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
207 if (sfile
== NULL
|| STREQ (msymbol
->filename
, sfile
))
208 found_file_symbol
= msymbol
;
210 /* We have neither the ability nor the need to
211 deal with the SFILE parameter. If we find
212 more than one symbol, just return the latest
213 one (the user can't expect useful behavior in
215 found_file_symbol
= msymbol
;
219 case mst_solib_trampoline
:
221 /* If a trampoline symbol is found, we prefer to
222 keep looking for the *real* symbol. If the
223 actual symbol is not found, then we'll use the
225 if (trampoline_symbol
== NULL
)
226 trampoline_symbol
= msymbol
;
231 found_symbol
= msymbol
;
236 /* Find the next symbol on the hash chain. */
238 msymbol
= msymbol
->hash_next
;
240 msymbol
= msymbol
->demangled_hash_next
;
245 /* External symbols are best. */
249 /* File-local symbols are next best. */
250 if (found_file_symbol
)
251 return found_file_symbol
;
253 /* Symbols for shared library trampolines are next best. */
254 if (trampoline_symbol
)
255 return trampoline_symbol
;
260 /* Look through all the current minimal symbol tables and find the
261 first minimal symbol that matches NAME and of text type.
262 If OBJF is non-NULL, limit
263 the search to that objfile. If SFILE is non-NULL, limit the search
264 to that source file. Returns a pointer to the minimal symbol that
265 matches, or NULL if no match is found.
268 struct minimal_symbol
*
269 lookup_minimal_symbol_text (name
, sfile
, objf
)
270 register const char *name
;
272 struct objfile
*objf
;
274 struct objfile
*objfile
;
275 struct minimal_symbol
*msymbol
;
276 struct minimal_symbol
*found_symbol
= NULL
;
277 struct minimal_symbol
*found_file_symbol
= NULL
;
279 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
282 char *p
= strrchr (sfile
, '/');
288 for (objfile
= object_files
;
289 objfile
!= NULL
&& found_symbol
== NULL
;
290 objfile
= objfile
->next
)
292 if (objf
== NULL
|| objf
== objfile
)
294 for (msymbol
= objfile
->msymbols
;
295 msymbol
!= NULL
&& SYMBOL_NAME (msymbol
) != NULL
&&
296 found_symbol
== NULL
;
299 if (SYMBOL_MATCHES_NAME (msymbol
, name
) &&
300 (MSYMBOL_TYPE (msymbol
) == mst_text
||
301 MSYMBOL_TYPE (msymbol
) == mst_file_text
))
303 switch (MSYMBOL_TYPE (msymbol
))
306 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
307 if (sfile
== NULL
|| STREQ (msymbol
->filename
, sfile
))
308 found_file_symbol
= msymbol
;
310 /* We have neither the ability nor the need to
311 deal with the SFILE parameter. If we find
312 more than one symbol, just return the latest
313 one (the user can't expect useful behavior in
315 found_file_symbol
= msymbol
;
319 found_symbol
= msymbol
;
326 /* External symbols are best. */
330 /* File-local symbols are next best. */
331 if (found_file_symbol
)
332 return found_file_symbol
;
337 /* Look through all the current minimal symbol tables and find the
338 first minimal symbol that matches NAME and of solib trampoline type.
339 If OBJF is non-NULL, limit
340 the search to that objfile. If SFILE is non-NULL, limit the search
341 to that source file. Returns a pointer to the minimal symbol that
342 matches, or NULL if no match is found.
345 struct minimal_symbol
*
346 lookup_minimal_symbol_solib_trampoline (name
, sfile
, objf
)
347 register const char *name
;
349 struct objfile
*objf
;
351 struct objfile
*objfile
;
352 struct minimal_symbol
*msymbol
;
353 struct minimal_symbol
*found_symbol
= NULL
;
355 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
358 char *p
= strrchr (sfile
, '/');
364 for (objfile
= object_files
;
365 objfile
!= NULL
&& found_symbol
== NULL
;
366 objfile
= objfile
->next
)
368 if (objf
== NULL
|| objf
== objfile
)
370 for (msymbol
= objfile
->msymbols
;
371 msymbol
!= NULL
&& SYMBOL_NAME (msymbol
) != NULL
&&
372 found_symbol
== NULL
;
375 if (SYMBOL_MATCHES_NAME (msymbol
, name
) &&
376 MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
386 /* Search through the minimal symbol table for each objfile and find
387 the symbol whose address is the largest address that is still less
388 than or equal to PC, and matches SECTION (if non-null). Returns a
389 pointer to the minimal symbol if such a symbol is found, or NULL if
390 PC is not in a suitable range. Note that we need to look through
391 ALL the minimal symbol tables before deciding on the symbol that
392 comes closest to the specified PC. This is because objfiles can
393 overlap, for example objfile A has .text at 0x100 and .data at
394 0x40000 and objfile B has .text at 0x234 and .data at 0x40048. */
396 struct minimal_symbol
*
397 lookup_minimal_symbol_by_pc_section (pc
, section
)
404 struct objfile
*objfile
;
405 struct minimal_symbol
*msymbol
;
406 struct minimal_symbol
*best_symbol
= NULL
;
408 /* pc has to be in a known section. This ensures that anything beyond
409 the end of the last segment doesn't appear to be part of the last
410 function in the last segment. */
411 if (find_pc_section (pc
) == NULL
)
414 for (objfile
= object_files
;
416 objfile
= objfile
->next
)
418 /* If this objfile has a minimal symbol table, go search it using
419 a binary search. Note that a minimal symbol table always consists
420 of at least two symbols, a "real" symbol and the terminating
421 "null symbol". If there are no real symbols, then there is no
422 minimal symbol table at all. */
424 if ((msymbol
= objfile
->msymbols
) != NULL
)
427 hi
= objfile
->minimal_symbol_count
- 1;
429 /* This code assumes that the minimal symbols are sorted by
430 ascending address values. If the pc value is greater than or
431 equal to the first symbol's address, then some symbol in this
432 minimal symbol table is a suitable candidate for being the
433 "best" symbol. This includes the last real symbol, for cases
434 where the pc value is larger than any address in this vector.
436 By iterating until the address associated with the current
437 hi index (the endpoint of the test interval) is less than
438 or equal to the desired pc value, we accomplish two things:
439 (1) the case where the pc value is larger than any minimal
440 symbol address is trivially solved, (2) the address associated
441 with the hi index is always the one we want when the interation
442 terminates. In essence, we are iterating the test interval
443 down until the pc value is pushed out of it from the high end.
445 Warning: this code is trickier than it would appear at first. */
447 /* Should also require that pc is <= end of objfile. FIXME! */
448 if (pc
>= SYMBOL_VALUE_ADDRESS (&msymbol
[lo
]))
450 while (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]) > pc
)
452 /* pc is still strictly less than highest address */
453 /* Note "new" will always be >= lo */
455 if ((SYMBOL_VALUE_ADDRESS (&msymbol
[new]) >= pc
) ||
466 /* If we have multiple symbols at the same address, we want
467 hi to point to the last one. That way we can find the
468 right symbol if it has an index greater than hi. */
469 while (hi
< objfile
->minimal_symbol_count
- 1
470 && (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
471 == SYMBOL_VALUE_ADDRESS (&msymbol
[hi
+ 1])))
474 /* The minimal symbol indexed by hi now is the best one in this
475 objfile's minimal symbol table. See if it is the best one
478 /* Skip any absolute symbols. This is apparently what adb
479 and dbx do, and is needed for the CM-5. There are two
480 known possible problems: (1) on ELF, apparently end, edata,
481 etc. are absolute. Not sure ignoring them here is a big
482 deal, but if we want to use them, the fix would go in
483 elfread.c. (2) I think shared library entry points on the
484 NeXT are absolute. If we want special handling for this
485 it probably should be triggered by a special
486 mst_abs_or_lib or some such. */
488 && msymbol
[hi
].type
== mst_abs
)
491 /* If "section" specified, skip any symbol from wrong section */
492 /* This is the new code that distinguishes it from the old function */
495 && SYMBOL_BFD_SECTION (&msymbol
[hi
]) != section
)
499 && ((best_symbol
== NULL
) ||
500 (SYMBOL_VALUE_ADDRESS (best_symbol
) <
501 SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]))))
503 best_symbol
= &msymbol
[hi
];
508 return (best_symbol
);
511 /* Backward compatibility: search through the minimal symbol table
512 for a matching PC (no section given) */
514 struct minimal_symbol
*
515 lookup_minimal_symbol_by_pc (pc
)
518 return lookup_minimal_symbol_by_pc_section (pc
, find_pc_mapped_section (pc
));
521 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
523 find_stab_function_addr (namestring
, filename
, objfile
)
526 struct objfile
*objfile
;
528 struct minimal_symbol
*msym
;
532 p
= strchr (namestring
, ':');
537 strncpy (p
, namestring
, n
);
540 msym
= lookup_minimal_symbol (p
, filename
, objfile
);
543 /* Sun Fortran appends an underscore to the minimal symbol name,
544 try again with an appended underscore if the minimal symbol
548 msym
= lookup_minimal_symbol (p
, filename
, objfile
);
551 if (msym
== NULL
&& filename
!= NULL
)
553 /* Try again without the filename. */
555 msym
= lookup_minimal_symbol (p
, 0, objfile
);
557 if (msym
== NULL
&& filename
!= NULL
)
559 /* And try again for Sun Fortran, but without the filename. */
562 msym
= lookup_minimal_symbol (p
, 0, objfile
);
565 return msym
== NULL
? 0 : SYMBOL_VALUE_ADDRESS (msym
);
567 #endif /* SOFUN_ADDRESS_MAYBE_MISSING */
570 /* Return leading symbol character for a BFD. If BFD is NULL,
571 return the leading symbol character from the main objfile. */
573 static int get_symbol_leading_char
PARAMS ((bfd
*));
576 get_symbol_leading_char (abfd
)
580 return bfd_get_symbol_leading_char (abfd
);
581 if (symfile_objfile
!= NULL
&& symfile_objfile
->obfd
!= NULL
)
582 return bfd_get_symbol_leading_char (symfile_objfile
->obfd
);
586 /* Prepare to start collecting minimal symbols. Note that presetting
587 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
588 symbol to allocate the memory for the first bunch. */
591 init_minimal_symbol_collection ()
595 msym_bunch_index
= BUNCH_SIZE
;
599 prim_record_minimal_symbol (name
, address
, ms_type
, objfile
)
602 enum minimal_symbol_type ms_type
;
603 struct objfile
*objfile
;
611 case mst_solib_trampoline
:
612 section
= SECT_OFF_TEXT (objfile
);
616 section
= SECT_OFF_DATA (objfile
);
620 section
= SECT_OFF_BSS (objfile
);
626 prim_record_minimal_symbol_and_info (name
, address
, ms_type
,
627 NULL
, section
, NULL
, objfile
);
630 /* Record a minimal symbol in the msym bunches. Returns the symbol
633 struct minimal_symbol
*
634 prim_record_minimal_symbol_and_info (name
, address
, ms_type
, info
, section
,
635 bfd_section
, objfile
)
638 enum minimal_symbol_type ms_type
;
641 asection
*bfd_section
;
642 struct objfile
*objfile
;
644 register struct msym_bunch
*new;
645 register struct minimal_symbol
*msymbol
;
647 if (ms_type
== mst_file_text
)
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
655 && (strcmp (name
, GCC_COMPILED_FLAG_SYMBOL
) == 0
656 || strcmp (name
, GCC2_COMPILED_FLAG_SYMBOL
) == 0))
660 const char *tempstring
= name
;
661 if (tempstring
[0] == get_symbol_leading_char (objfile
->obfd
))
663 if (STREQN (tempstring
, "__gnu_compiled", 14))
668 if (msym_bunch_index
== BUNCH_SIZE
)
670 new = (struct msym_bunch
*) xmalloc (sizeof (struct msym_bunch
));
671 msym_bunch_index
= 0;
672 new->next
= msym_bunch
;
675 msymbol
= &msym_bunch
->contents
[msym_bunch_index
];
676 SYMBOL_NAME (msymbol
) = obsavestring ((char *) name
, strlen (name
),
677 &objfile
->symbol_obstack
);
678 SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol
, language_unknown
);
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! */
687 /* The hash pointers must be cleared! If they're not,
688 add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
689 msymbol
->hash_next
= NULL
;
690 msymbol
->demangled_hash_next
= NULL
;
694 OBJSTAT (objfile
, n_minsyms
++);
698 /* Compare two minimal symbols by address and return a signed result based
699 on unsigned comparisons, so that we sort into unsigned numeric order.
700 Within groups with the same address, sort by name. */
703 compare_minimal_symbols (fn1p
, fn2p
)
707 register const struct minimal_symbol
*fn1
;
708 register const struct minimal_symbol
*fn2
;
710 fn1
= (const struct minimal_symbol
*) fn1p
;
711 fn2
= (const struct minimal_symbol
*) fn2p
;
713 if (SYMBOL_VALUE_ADDRESS (fn1
) < SYMBOL_VALUE_ADDRESS (fn2
))
715 return (-1); /* addr 1 is less than addr 2 */
717 else if (SYMBOL_VALUE_ADDRESS (fn1
) > SYMBOL_VALUE_ADDRESS (fn2
))
719 return (1); /* addr 1 is greater than addr 2 */
722 /* addrs are equal: sort by name */
724 char *name1
= SYMBOL_NAME (fn1
);
725 char *name2
= SYMBOL_NAME (fn2
);
727 if (name1
&& name2
) /* both have names */
728 return strcmp (name1
, name2
);
730 return 1; /* fn1 has no name, so it is "less" */
731 else if (name1
) /* fn2 has no name, so it is "less" */
734 return (0); /* neither has a name, so they're equal. */
738 /* Discard the currently collected minimal symbols, if any. If we wish
739 to save them for later use, we must have already copied them somewhere
740 else before calling this function.
742 FIXME: We could allocate the minimal symbol bunches on their own
743 obstack and then simply blow the obstack away when we are done with
744 it. Is it worth the extra trouble though? */
747 do_discard_minimal_symbols_cleanup (void *arg
)
749 register struct msym_bunch
*next
;
751 while (msym_bunch
!= NULL
)
753 next
= msym_bunch
->next
;
754 free ((PTR
) msym_bunch
);
760 make_cleanup_discard_minimal_symbols (void)
762 return make_cleanup (do_discard_minimal_symbols_cleanup
, 0);
767 /* Compact duplicate entries out of a minimal symbol table by walking
768 through the table and compacting out entries with duplicate addresses
769 and matching names. Return the number of entries remaining.
771 On entry, the table resides between msymbol[0] and msymbol[mcount].
772 On exit, it resides between msymbol[0] and msymbol[result_count].
774 When files contain multiple sources of symbol information, it is
775 possible for the minimal symbol table to contain many duplicate entries.
776 As an example, SVR4 systems use ELF formatted object files, which
777 usually contain at least two different types of symbol tables (a
778 standard ELF one and a smaller dynamic linking table), as well as
779 DWARF debugging information for files compiled with -g.
781 Without compacting, the minimal symbol table for gdb itself contains
782 over a 1000 duplicates, about a third of the total table size. Aside
783 from the potential trap of not noticing that two successive entries
784 identify the same location, this duplication impacts the time required
785 to linearly scan the table, which is done in a number of places. So we
786 just do one linear scan here and toss out the duplicates.
788 Note that we are not concerned here about recovering the space that
789 is potentially freed up, because the strings themselves are allocated
790 on the symbol_obstack, and will get automatically freed when the symbol
791 table is freed. The caller can free up the unused minimal symbols at
792 the end of the compacted region if their allocation strategy allows it.
794 Also note we only go up to the next to last entry within the loop
795 and then copy the last entry explicitly after the loop terminates.
797 Since the different sources of information for each symbol may
798 have different levels of "completeness", we may have duplicates
799 that have one entry with type "mst_unknown" and the other with a
800 known type. So if the one we are leaving alone has type mst_unknown,
801 overwrite its type with the type from the one we are compacting out. */
804 compact_minimal_symbols (msymbol
, mcount
, objfile
)
805 struct minimal_symbol
*msymbol
;
807 struct objfile
*objfile
;
809 struct minimal_symbol
*copyfrom
;
810 struct minimal_symbol
*copyto
;
814 copyfrom
= copyto
= msymbol
;
815 while (copyfrom
< msymbol
+ mcount
- 1)
817 if (SYMBOL_VALUE_ADDRESS (copyfrom
) ==
818 SYMBOL_VALUE_ADDRESS ((copyfrom
+ 1)) &&
819 (STREQ (SYMBOL_NAME (copyfrom
), SYMBOL_NAME ((copyfrom
+ 1)))))
821 if (MSYMBOL_TYPE ((copyfrom
+ 1)) == mst_unknown
)
823 MSYMBOL_TYPE ((copyfrom
+ 1)) = MSYMBOL_TYPE (copyfrom
);
829 *copyto
++ = *copyfrom
++;
831 add_minsym_to_hash_table (copyto
- 1, objfile
->msymbol_hash
);
834 *copyto
++ = *copyfrom
++;
835 mcount
= copyto
- msymbol
;
840 /* Add the minimal symbols in the existing bunches to the objfile's official
841 minimal symbol table. In most cases there is no minimal symbol table yet
842 for this objfile, and the existing bunches are used to create one. Once
843 in a while (for shared libraries for example), we add symbols (e.g. common
844 symbols) to an existing objfile.
846 Because of the way minimal symbols are collected, we generally have no way
847 of knowing what source language applies to any particular minimal symbol.
848 Specifically, we have no way of knowing if the minimal symbol comes from a
849 C++ compilation unit or not. So for the sake of supporting cached
850 demangled C++ names, we have no choice but to try and demangle each new one
851 that comes in. If the demangling succeeds, then we assume it is a C++
852 symbol and set the symbol's language and demangled name fields
853 appropriately. Note that in order to avoid unnecessary demanglings, and
854 allocating obstack space that subsequently can't be freed for the demangled
855 names, we mark all newly added symbols with language_auto. After
856 compaction of the minimal symbols, we go back and scan the entire minimal
857 symbol table looking for these new symbols. For each new symbol we attempt
858 to demangle it, and if successful, record it as a language_cplus symbol
859 and cache the demangled form on the symbol obstack. Symbols which don't
860 demangle are marked as language_unknown symbols, which inhibits future
861 attempts to demangle them if we later add more minimal symbols. */
864 install_minimal_symbols (objfile
)
865 struct objfile
*objfile
;
869 register struct msym_bunch
*bunch
;
870 register struct minimal_symbol
*msymbols
;
872 register char leading_char
;
876 /* Allocate enough space in the obstack, into which we will gather the
877 bunches of new and existing minimal symbols, sort them, and then
878 compact out the duplicate entries. Once we have a final table,
879 we will give back the excess space. */
881 alloc_count
= msym_count
+ objfile
->minimal_symbol_count
+ 1;
882 obstack_blank (&objfile
->symbol_obstack
,
883 alloc_count
* sizeof (struct minimal_symbol
));
884 msymbols
= (struct minimal_symbol
*)
885 obstack_base (&objfile
->symbol_obstack
);
887 /* Copy in the existing minimal symbols, if there are any. */
889 if (objfile
->minimal_symbol_count
)
890 memcpy ((char *) msymbols
, (char *) objfile
->msymbols
,
891 objfile
->minimal_symbol_count
* sizeof (struct minimal_symbol
));
893 /* Walk through the list of minimal symbol bunches, adding each symbol
894 to the new contiguous array of symbols. Note that we start with the
895 current, possibly partially filled bunch (thus we use the current
896 msym_bunch_index for the first bunch we copy over), and thereafter
897 each bunch is full. */
899 mcount
= objfile
->minimal_symbol_count
;
900 leading_char
= get_symbol_leading_char (objfile
->obfd
);
902 for (bunch
= msym_bunch
; bunch
!= NULL
; bunch
= bunch
->next
)
904 for (bindex
= 0; bindex
< msym_bunch_index
; bindex
++, mcount
++)
906 msymbols
[mcount
] = bunch
->contents
[bindex
];
907 SYMBOL_LANGUAGE (&msymbols
[mcount
]) = language_auto
;
908 if (SYMBOL_NAME (&msymbols
[mcount
])[0] == leading_char
)
910 SYMBOL_NAME (&msymbols
[mcount
])++;
913 msym_bunch_index
= BUNCH_SIZE
;
916 /* Sort the minimal symbols by address. */
918 qsort (msymbols
, mcount
, sizeof (struct minimal_symbol
),
919 compare_minimal_symbols
);
921 /* Compact out any duplicates, and free up whatever space we are
924 mcount
= compact_minimal_symbols (msymbols
, mcount
, objfile
);
926 obstack_blank (&objfile
->symbol_obstack
,
927 (mcount
+ 1 - alloc_count
) * sizeof (struct minimal_symbol
));
928 msymbols
= (struct minimal_symbol
*)
929 obstack_finish (&objfile
->symbol_obstack
);
931 /* We also terminate the minimal symbol table with a "null symbol",
932 which is *not* included in the size of the table. This makes it
933 easier to find the end of the table when we are handed a pointer
934 to some symbol in the middle of it. Zero out the fields in the
935 "null symbol" allocated at the end of the array. Note that the
936 symbol count does *not* include this null symbol, which is why it
937 is indexed by mcount and not mcount-1. */
939 SYMBOL_NAME (&msymbols
[mcount
]) = NULL
;
940 SYMBOL_VALUE_ADDRESS (&msymbols
[mcount
]) = 0;
941 MSYMBOL_INFO (&msymbols
[mcount
]) = NULL
;
942 MSYMBOL_TYPE (&msymbols
[mcount
]) = mst_unknown
;
943 SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols
[mcount
], language_unknown
);
945 /* Attach the minimal symbol table to the specified objfile.
946 The strings themselves are also located in the symbol_obstack
949 objfile
->minimal_symbol_count
= mcount
;
950 objfile
->msymbols
= msymbols
;
952 /* Now walk through all the minimal symbols, selecting the newly added
953 ones and attempting to cache their C++ demangled names. */
955 for (; mcount
-- > 0; msymbols
++)
957 SYMBOL_INIT_DEMANGLED_NAME (msymbols
, &objfile
->symbol_obstack
);
958 if (SYMBOL_DEMANGLED_NAME (msymbols
) != NULL
)
959 add_minsym_to_demangled_hash_table (msymbols
,
960 objfile
->msymbol_demangled_hash
);
965 /* Sort all the minimal symbols in OBJFILE. */
968 msymbols_sort (objfile
)
969 struct objfile
*objfile
;
971 qsort (objfile
->msymbols
, objfile
->minimal_symbol_count
,
972 sizeof (struct minimal_symbol
), compare_minimal_symbols
);
975 /* Check if PC is in a shared library trampoline code stub.
976 Return minimal symbol for the trampoline entry or NULL if PC is not
977 in a trampoline code stub. */
979 struct minimal_symbol
*
980 lookup_solib_trampoline_symbol_by_pc (pc
)
983 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (pc
);
985 if (msymbol
!= NULL
&& MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
990 /* If PC is in a shared library trampoline code stub, return the
991 address of the `real' function belonging to the stub.
992 Return 0 if PC is not in a trampoline code stub or if the real
993 function is not found in the minimal symbol table.
995 We may fail to find the right function if a function with the
996 same name is defined in more than one shared library, but this
997 is considered bad programming style. We could return 0 if we find
998 a duplicate function in case this matters someday. */
1001 find_solib_trampoline_target (pc
)
1004 struct objfile
*objfile
;
1005 struct minimal_symbol
*msymbol
;
1006 struct minimal_symbol
*tsymbol
= lookup_solib_trampoline_symbol_by_pc (pc
);
1008 if (tsymbol
!= NULL
)
1010 ALL_MSYMBOLS (objfile
, msymbol
)
1012 if (MSYMBOL_TYPE (msymbol
) == mst_text
1013 && STREQ (SYMBOL_NAME (msymbol
), SYMBOL_NAME (tsymbol
)))
1014 return SYMBOL_VALUE_ADDRESS (msymbol
);