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 /* Compute a hash code based using the same criteria as `strcmp_iw'. */
88 msymbol_hash_iw (const char *string
)
90 unsigned int hash
= 0;
91 while (*string
&& *string
!= '(')
93 while (isspace (*string
))
95 if (*string
&& *string
!= '(')
96 hash
= (31 * hash
) + *string
;
99 return hash
% MINIMAL_SYMBOL_HASH_SIZE
;
102 /* Compute a hash code for a string. */
105 msymbol_hash (const char *string
)
107 unsigned int hash
= 0;
108 for (; *string
; ++string
)
109 hash
= (31 * hash
) + *string
;
110 return hash
% MINIMAL_SYMBOL_HASH_SIZE
;
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
)
120 unsigned int hash
= msymbol_hash (SYMBOL_NAME (sym
));
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 (SYMBOL_DEMANGLED_NAME (sym
));
135 sym
->demangled_hash_next
= table
[hash
];
141 /* Look through all the current minimal symbol tables and find the
142 first minimal symbol that matches NAME. If OBJF is non-NULL, limit
143 the search to that objfile. If SFILE is non-NULL, limit the search
144 to that source file. Returns a pointer to the minimal symbol that
145 matches, or NULL if no match is found.
147 Note: One instance where there may be duplicate minimal symbols with
148 the same name is when the symbol tables for a shared library and the
149 symbol tables for an executable contain global symbols with the same
150 names (the dynamic linker deals with the duplication). */
152 struct minimal_symbol
*
153 lookup_minimal_symbol (name
, sfile
, objf
)
154 register const char *name
;
156 struct objfile
*objf
;
158 struct objfile
*objfile
;
159 struct minimal_symbol
*msymbol
;
160 struct minimal_symbol
*found_symbol
= NULL
;
161 struct minimal_symbol
*found_file_symbol
= NULL
;
162 struct minimal_symbol
*trampoline_symbol
= NULL
;
164 unsigned int hash
= msymbol_hash (name
);
165 unsigned int dem_hash
= msymbol_hash_iw (name
);
167 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
170 char *p
= strrchr (sfile
, '/');
176 for (objfile
= object_files
;
177 objfile
!= NULL
&& found_symbol
== NULL
;
178 objfile
= objfile
->next
)
180 if (objf
== NULL
|| objf
== objfile
)
182 /* Do two passes: the first over the ordinary hash table,
183 and the second over the demangled hash table. */
186 for (pass
= 1; pass
<= 2 && found_symbol
== NULL
; pass
++)
188 /* Select hash list according to pass. */
190 msymbol
= objfile
->msymbol_hash
[hash
];
192 msymbol
= objfile
->msymbol_demangled_hash
[dem_hash
];
194 while (msymbol
!= NULL
&& found_symbol
== NULL
)
196 if (SYMBOL_MATCHES_NAME (msymbol
, name
))
198 switch (MSYMBOL_TYPE (msymbol
))
203 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
204 if (sfile
== NULL
|| STREQ (msymbol
->filename
, sfile
))
205 found_file_symbol
= msymbol
;
207 /* We have neither the ability nor the need to
208 deal with the SFILE parameter. If we find
209 more than one symbol, just return the latest
210 one (the user can't expect useful behavior in
212 found_file_symbol
= msymbol
;
216 case mst_solib_trampoline
:
218 /* If a trampoline symbol is found, we prefer to
219 keep looking for the *real* symbol. If the
220 actual symbol is not found, then we'll use the
222 if (trampoline_symbol
== NULL
)
223 trampoline_symbol
= msymbol
;
228 found_symbol
= msymbol
;
233 /* Find the next symbol on the hash chain. */
235 msymbol
= msymbol
->hash_next
;
237 msymbol
= msymbol
->demangled_hash_next
;
242 /* External symbols are best. */
246 /* File-local symbols are next best. */
247 if (found_file_symbol
)
248 return found_file_symbol
;
250 /* Symbols for shared library trampolines are next best. */
251 if (trampoline_symbol
)
252 return trampoline_symbol
;
257 /* Look through all the current minimal symbol tables and find the
258 first minimal symbol that matches NAME and of text type.
259 If OBJF is non-NULL, limit
260 the search to that objfile. If SFILE is non-NULL, limit the search
261 to that source file. Returns a pointer to the minimal symbol that
262 matches, or NULL if no match is found.
265 struct minimal_symbol
*
266 lookup_minimal_symbol_text (name
, sfile
, objf
)
267 register const char *name
;
269 struct objfile
*objf
;
271 struct objfile
*objfile
;
272 struct minimal_symbol
*msymbol
;
273 struct minimal_symbol
*found_symbol
= NULL
;
274 struct minimal_symbol
*found_file_symbol
= NULL
;
276 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
279 char *p
= strrchr (sfile
, '/');
285 for (objfile
= object_files
;
286 objfile
!= NULL
&& found_symbol
== NULL
;
287 objfile
= objfile
->next
)
289 if (objf
== NULL
|| objf
== objfile
)
291 for (msymbol
= objfile
->msymbols
;
292 msymbol
!= NULL
&& SYMBOL_NAME (msymbol
) != NULL
&&
293 found_symbol
== NULL
;
296 if (SYMBOL_MATCHES_NAME (msymbol
, name
) &&
297 (MSYMBOL_TYPE (msymbol
) == mst_text
||
298 MSYMBOL_TYPE (msymbol
) == mst_file_text
))
300 switch (MSYMBOL_TYPE (msymbol
))
303 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
304 if (sfile
== NULL
|| STREQ (msymbol
->filename
, sfile
))
305 found_file_symbol
= msymbol
;
307 /* We have neither the ability nor the need to
308 deal with the SFILE parameter. If we find
309 more than one symbol, just return the latest
310 one (the user can't expect useful behavior in
312 found_file_symbol
= msymbol
;
316 found_symbol
= msymbol
;
323 /* External symbols are best. */
327 /* File-local symbols are next best. */
328 if (found_file_symbol
)
329 return found_file_symbol
;
334 /* Look through all the current minimal symbol tables and find the
335 first minimal symbol that matches NAME and of solib trampoline type.
336 If OBJF is non-NULL, limit
337 the search to that objfile. If SFILE is non-NULL, limit the search
338 to that source file. Returns a pointer to the minimal symbol that
339 matches, or NULL if no match is found.
342 struct minimal_symbol
*
343 lookup_minimal_symbol_solib_trampoline (name
, sfile
, objf
)
344 register const char *name
;
346 struct objfile
*objf
;
348 struct objfile
*objfile
;
349 struct minimal_symbol
*msymbol
;
350 struct minimal_symbol
*found_symbol
= NULL
;
352 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
355 char *p
= strrchr (sfile
, '/');
361 for (objfile
= object_files
;
362 objfile
!= NULL
&& found_symbol
== NULL
;
363 objfile
= objfile
->next
)
365 if (objf
== NULL
|| objf
== objfile
)
367 for (msymbol
= objfile
->msymbols
;
368 msymbol
!= NULL
&& SYMBOL_NAME (msymbol
) != NULL
&&
369 found_symbol
== NULL
;
372 if (SYMBOL_MATCHES_NAME (msymbol
, name
) &&
373 MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
383 /* Search through the minimal symbol table for each objfile and find
384 the symbol whose address is the largest address that is still less
385 than or equal to PC, and matches SECTION (if non-null). Returns a
386 pointer to the minimal symbol if such a symbol is found, or NULL if
387 PC is not in a suitable range. Note that we need to look through
388 ALL the minimal symbol tables before deciding on the symbol that
389 comes closest to the specified PC. This is because objfiles can
390 overlap, for example objfile A has .text at 0x100 and .data at
391 0x40000 and objfile B has .text at 0x234 and .data at 0x40048. */
393 struct minimal_symbol
*
394 lookup_minimal_symbol_by_pc_section (pc
, section
)
401 struct objfile
*objfile
;
402 struct minimal_symbol
*msymbol
;
403 struct minimal_symbol
*best_symbol
= NULL
;
405 /* pc has to be in a known section. This ensures that anything beyond
406 the end of the last segment doesn't appear to be part of the last
407 function in the last segment. */
408 if (find_pc_section (pc
) == NULL
)
411 for (objfile
= object_files
;
413 objfile
= objfile
->next
)
415 /* If this objfile has a minimal symbol table, go search it using
416 a binary search. Note that a minimal symbol table always consists
417 of at least two symbols, a "real" symbol and the terminating
418 "null symbol". If there are no real symbols, then there is no
419 minimal symbol table at all. */
421 if ((msymbol
= objfile
->msymbols
) != NULL
)
424 hi
= objfile
->minimal_symbol_count
- 1;
426 /* This code assumes that the minimal symbols are sorted by
427 ascending address values. If the pc value is greater than or
428 equal to the first symbol's address, then some symbol in this
429 minimal symbol table is a suitable candidate for being the
430 "best" symbol. This includes the last real symbol, for cases
431 where the pc value is larger than any address in this vector.
433 By iterating until the address associated with the current
434 hi index (the endpoint of the test interval) is less than
435 or equal to the desired pc value, we accomplish two things:
436 (1) the case where the pc value is larger than any minimal
437 symbol address is trivially solved, (2) the address associated
438 with the hi index is always the one we want when the interation
439 terminates. In essence, we are iterating the test interval
440 down until the pc value is pushed out of it from the high end.
442 Warning: this code is trickier than it would appear at first. */
444 /* Should also require that pc is <= end of objfile. FIXME! */
445 if (pc
>= SYMBOL_VALUE_ADDRESS (&msymbol
[lo
]))
447 while (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]) > pc
)
449 /* pc is still strictly less than highest address */
450 /* Note "new" will always be >= lo */
452 if ((SYMBOL_VALUE_ADDRESS (&msymbol
[new]) >= pc
) ||
463 /* If we have multiple symbols at the same address, we want
464 hi to point to the last one. That way we can find the
465 right symbol if it has an index greater than hi. */
466 while (hi
< objfile
->minimal_symbol_count
- 1
467 && (SYMBOL_VALUE_ADDRESS (&msymbol
[hi
])
468 == SYMBOL_VALUE_ADDRESS (&msymbol
[hi
+ 1])))
471 /* The minimal symbol indexed by hi now is the best one in this
472 objfile's minimal symbol table. See if it is the best one
475 /* Skip any absolute symbols. This is apparently what adb
476 and dbx do, and is needed for the CM-5. There are two
477 known possible problems: (1) on ELF, apparently end, edata,
478 etc. are absolute. Not sure ignoring them here is a big
479 deal, but if we want to use them, the fix would go in
480 elfread.c. (2) I think shared library entry points on the
481 NeXT are absolute. If we want special handling for this
482 it probably should be triggered by a special
483 mst_abs_or_lib or some such. */
485 && msymbol
[hi
].type
== mst_abs
)
488 /* If "section" specified, skip any symbol from wrong section */
489 /* This is the new code that distinguishes it from the old function */
492 && SYMBOL_BFD_SECTION (&msymbol
[hi
]) != section
)
496 && ((best_symbol
== NULL
) ||
497 (SYMBOL_VALUE_ADDRESS (best_symbol
) <
498 SYMBOL_VALUE_ADDRESS (&msymbol
[hi
]))))
500 best_symbol
= &msymbol
[hi
];
505 return (best_symbol
);
508 /* Backward compatibility: search through the minimal symbol table
509 for a matching PC (no section given) */
511 struct minimal_symbol
*
512 lookup_minimal_symbol_by_pc (pc
)
515 return lookup_minimal_symbol_by_pc_section (pc
, find_pc_mapped_section (pc
));
518 #ifdef SOFUN_ADDRESS_MAYBE_MISSING
520 find_stab_function_addr (namestring
, filename
, objfile
)
523 struct objfile
*objfile
;
525 struct minimal_symbol
*msym
;
529 p
= strchr (namestring
, ':');
534 strncpy (p
, namestring
, n
);
537 msym
= lookup_minimal_symbol (p
, filename
, objfile
);
540 /* Sun Fortran appends an underscore to the minimal symbol name,
541 try again with an appended underscore if the minimal symbol
545 msym
= lookup_minimal_symbol (p
, filename
, objfile
);
548 if (msym
== NULL
&& filename
!= NULL
)
550 /* Try again without the filename. */
552 msym
= lookup_minimal_symbol (p
, 0, objfile
);
554 if (msym
== NULL
&& filename
!= NULL
)
556 /* And try again for Sun Fortran, but without the filename. */
559 msym
= lookup_minimal_symbol (p
, 0, objfile
);
562 return msym
== NULL
? 0 : SYMBOL_VALUE_ADDRESS (msym
);
564 #endif /* SOFUN_ADDRESS_MAYBE_MISSING */
567 /* Return leading symbol character for a BFD. If BFD is NULL,
568 return the leading symbol character from the main objfile. */
570 static int get_symbol_leading_char
PARAMS ((bfd
*));
573 get_symbol_leading_char (abfd
)
577 return bfd_get_symbol_leading_char (abfd
);
578 if (symfile_objfile
!= NULL
&& symfile_objfile
->obfd
!= NULL
)
579 return bfd_get_symbol_leading_char (symfile_objfile
->obfd
);
583 /* Prepare to start collecting minimal symbols. Note that presetting
584 msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
585 symbol to allocate the memory for the first bunch. */
588 init_minimal_symbol_collection ()
592 msym_bunch_index
= BUNCH_SIZE
;
596 prim_record_minimal_symbol (name
, address
, ms_type
, objfile
)
599 enum minimal_symbol_type ms_type
;
600 struct objfile
*objfile
;
608 case mst_solib_trampoline
:
609 section
= SECT_OFF_TEXT
;
613 section
= SECT_OFF_DATA
;
617 section
= SECT_OFF_BSS
;
623 prim_record_minimal_symbol_and_info (name
, address
, ms_type
,
624 NULL
, section
, NULL
, objfile
);
627 /* Record a minimal symbol in the msym bunches. Returns the symbol
630 struct minimal_symbol
*
631 prim_record_minimal_symbol_and_info (name
, address
, ms_type
, info
, section
,
632 bfd_section
, objfile
)
635 enum minimal_symbol_type ms_type
;
638 asection
*bfd_section
;
639 struct objfile
*objfile
;
641 register struct msym_bunch
*new;
642 register struct minimal_symbol
*msymbol
;
644 if (ms_type
== mst_file_text
)
646 /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
647 the minimal symbols, because if there is also another symbol
648 at the same address (e.g. the first function of the file),
649 lookup_minimal_symbol_by_pc would have no way of getting the
652 && (strcmp (name
, GCC_COMPILED_FLAG_SYMBOL
) == 0
653 || strcmp (name
, GCC2_COMPILED_FLAG_SYMBOL
) == 0))
657 const char *tempstring
= name
;
658 if (tempstring
[0] == get_symbol_leading_char (objfile
->obfd
))
660 if (STREQN (tempstring
, "__gnu_compiled", 14))
665 if (msym_bunch_index
== BUNCH_SIZE
)
667 new = (struct msym_bunch
*) xmalloc (sizeof (struct msym_bunch
));
668 msym_bunch_index
= 0;
669 new->next
= msym_bunch
;
672 msymbol
= &msym_bunch
->contents
[msym_bunch_index
];
673 SYMBOL_NAME (msymbol
) = obsavestring ((char *) name
, strlen (name
),
674 &objfile
->symbol_obstack
);
675 SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol
, language_unknown
);
676 SYMBOL_VALUE_ADDRESS (msymbol
) = address
;
677 SYMBOL_SECTION (msymbol
) = section
;
678 SYMBOL_BFD_SECTION (msymbol
) = bfd_section
;
680 MSYMBOL_TYPE (msymbol
) = ms_type
;
681 /* FIXME: This info, if it remains, needs its own field. */
682 MSYMBOL_INFO (msymbol
) = info
; /* FIXME! */
684 /* The hash pointers must be cleared! If they're not,
685 MSYMBOL_HASH_ADD will NOT add this msymbol to the hash table. */
686 msymbol
->hash_next
= NULL
;
687 msymbol
->demangled_hash_next
= NULL
;
691 OBJSTAT (objfile
, n_minsyms
++);
695 /* Compare two minimal symbols by address and return a signed result based
696 on unsigned comparisons, so that we sort into unsigned numeric order.
697 Within groups with the same address, sort by name. */
700 compare_minimal_symbols (fn1p
, fn2p
)
704 register const struct minimal_symbol
*fn1
;
705 register const struct minimal_symbol
*fn2
;
707 fn1
= (const struct minimal_symbol
*) fn1p
;
708 fn2
= (const struct minimal_symbol
*) fn2p
;
710 if (SYMBOL_VALUE_ADDRESS (fn1
) < SYMBOL_VALUE_ADDRESS (fn2
))
712 return (-1); /* addr 1 is less than addr 2 */
714 else if (SYMBOL_VALUE_ADDRESS (fn1
) > SYMBOL_VALUE_ADDRESS (fn2
))
716 return (1); /* addr 1 is greater than addr 2 */
719 /* addrs are equal: sort by name */
721 char *name1
= SYMBOL_NAME (fn1
);
722 char *name2
= SYMBOL_NAME (fn2
);
724 if (name1
&& name2
) /* both have names */
725 return strcmp (name1
, name2
);
727 return 1; /* fn1 has no name, so it is "less" */
728 else if (name1
) /* fn2 has no name, so it is "less" */
731 return (0); /* neither has a name, so they're equal. */
735 /* Discard the currently collected minimal symbols, if any. If we wish
736 to save them for later use, we must have already copied them somewhere
737 else before calling this function.
739 FIXME: We could allocate the minimal symbol bunches on their own
740 obstack and then simply blow the obstack away when we are done with
741 it. Is it worth the extra trouble though? */
745 discard_minimal_symbols (foo
)
748 register struct msym_bunch
*next
;
750 while (msym_bunch
!= NULL
)
752 next
= msym_bunch
->next
;
753 free ((PTR
) msym_bunch
);
759 /* Compact duplicate entries out of a minimal symbol table by walking
760 through the table and compacting out entries with duplicate addresses
761 and matching names. Return the number of entries remaining.
763 On entry, the table resides between msymbol[0] and msymbol[mcount].
764 On exit, it resides between msymbol[0] and msymbol[result_count].
766 When files contain multiple sources of symbol information, it is
767 possible for the minimal symbol table to contain many duplicate entries.
768 As an example, SVR4 systems use ELF formatted object files, which
769 usually contain at least two different types of symbol tables (a
770 standard ELF one and a smaller dynamic linking table), as well as
771 DWARF debugging information for files compiled with -g.
773 Without compacting, the minimal symbol table for gdb itself contains
774 over a 1000 duplicates, about a third of the total table size. Aside
775 from the potential trap of not noticing that two successive entries
776 identify the same location, this duplication impacts the time required
777 to linearly scan the table, which is done in a number of places. So we
778 just do one linear scan here and toss out the duplicates.
780 Note that we are not concerned here about recovering the space that
781 is potentially freed up, because the strings themselves are allocated
782 on the symbol_obstack, and will get automatically freed when the symbol
783 table is freed. The caller can free up the unused minimal symbols at
784 the end of the compacted region if their allocation strategy allows it.
786 Also note we only go up to the next to last entry within the loop
787 and then copy the last entry explicitly after the loop terminates.
789 Since the different sources of information for each symbol may
790 have different levels of "completeness", we may have duplicates
791 that have one entry with type "mst_unknown" and the other with a
792 known type. So if the one we are leaving alone has type mst_unknown,
793 overwrite its type with the type from the one we are compacting out. */
796 compact_minimal_symbols (msymbol
, mcount
, objfile
)
797 struct minimal_symbol
*msymbol
;
799 struct objfile
*objfile
;
801 struct minimal_symbol
*copyfrom
;
802 struct minimal_symbol
*copyto
;
806 copyfrom
= copyto
= msymbol
;
807 while (copyfrom
< msymbol
+ mcount
- 1)
809 if (SYMBOL_VALUE_ADDRESS (copyfrom
) ==
810 SYMBOL_VALUE_ADDRESS ((copyfrom
+ 1)) &&
811 (STREQ (SYMBOL_NAME (copyfrom
), SYMBOL_NAME ((copyfrom
+ 1)))))
813 if (MSYMBOL_TYPE ((copyfrom
+ 1)) == mst_unknown
)
815 MSYMBOL_TYPE ((copyfrom
+ 1)) = MSYMBOL_TYPE (copyfrom
);
821 *copyto
++ = *copyfrom
++;
823 add_minsym_to_hash_table (copyto
- 1, objfile
->msymbol_hash
);
826 *copyto
++ = *copyfrom
++;
827 mcount
= copyto
- msymbol
;
832 /* Add the minimal symbols in the existing bunches to the objfile's official
833 minimal symbol table. In most cases there is no minimal symbol table yet
834 for this objfile, and the existing bunches are used to create one. Once
835 in a while (for shared libraries for example), we add symbols (e.g. common
836 symbols) to an existing objfile.
838 Because of the way minimal symbols are collected, we generally have no way
839 of knowing what source language applies to any particular minimal symbol.
840 Specifically, we have no way of knowing if the minimal symbol comes from a
841 C++ compilation unit or not. So for the sake of supporting cached
842 demangled C++ names, we have no choice but to try and demangle each new one
843 that comes in. If the demangling succeeds, then we assume it is a C++
844 symbol and set the symbol's language and demangled name fields
845 appropriately. Note that in order to avoid unnecessary demanglings, and
846 allocating obstack space that subsequently can't be freed for the demangled
847 names, we mark all newly added symbols with language_auto. After
848 compaction of the minimal symbols, we go back and scan the entire minimal
849 symbol table looking for these new symbols. For each new symbol we attempt
850 to demangle it, and if successful, record it as a language_cplus symbol
851 and cache the demangled form on the symbol obstack. Symbols which don't
852 demangle are marked as language_unknown symbols, which inhibits future
853 attempts to demangle them if we later add more minimal symbols. */
856 install_minimal_symbols (objfile
)
857 struct objfile
*objfile
;
861 register struct msym_bunch
*bunch
;
862 register struct minimal_symbol
*msymbols
;
864 register char leading_char
;
868 /* Allocate enough space in the obstack, into which we will gather the
869 bunches of new and existing minimal symbols, sort them, and then
870 compact out the duplicate entries. Once we have a final table,
871 we will give back the excess space. */
873 alloc_count
= msym_count
+ objfile
->minimal_symbol_count
+ 1;
874 obstack_blank (&objfile
->symbol_obstack
,
875 alloc_count
* sizeof (struct minimal_symbol
));
876 msymbols
= (struct minimal_symbol
*)
877 obstack_base (&objfile
->symbol_obstack
);
879 /* Copy in the existing minimal symbols, if there are any. */
881 if (objfile
->minimal_symbol_count
)
882 memcpy ((char *) msymbols
, (char *) objfile
->msymbols
,
883 objfile
->minimal_symbol_count
* sizeof (struct minimal_symbol
));
885 /* Walk through the list of minimal symbol bunches, adding each symbol
886 to the new contiguous array of symbols. Note that we start with the
887 current, possibly partially filled bunch (thus we use the current
888 msym_bunch_index for the first bunch we copy over), and thereafter
889 each bunch is full. */
891 mcount
= objfile
->minimal_symbol_count
;
892 leading_char
= get_symbol_leading_char (objfile
->obfd
);
894 for (bunch
= msym_bunch
; bunch
!= NULL
; bunch
= bunch
->next
)
896 for (bindex
= 0; bindex
< msym_bunch_index
; bindex
++, mcount
++)
898 msymbols
[mcount
] = bunch
->contents
[bindex
];
899 SYMBOL_LANGUAGE (&msymbols
[mcount
]) = language_auto
;
900 if (SYMBOL_NAME (&msymbols
[mcount
])[0] == leading_char
)
902 SYMBOL_NAME (&msymbols
[mcount
])++;
905 msym_bunch_index
= BUNCH_SIZE
;
908 /* Sort the minimal symbols by address. */
910 qsort (msymbols
, mcount
, sizeof (struct minimal_symbol
),
911 compare_minimal_symbols
);
913 /* Compact out any duplicates, and free up whatever space we are
916 mcount
= compact_minimal_symbols (msymbols
, mcount
, objfile
);
918 obstack_blank (&objfile
->symbol_obstack
,
919 (mcount
+ 1 - alloc_count
) * sizeof (struct minimal_symbol
));
920 msymbols
= (struct minimal_symbol
*)
921 obstack_finish (&objfile
->symbol_obstack
);
923 /* We also terminate the minimal symbol table with a "null symbol",
924 which is *not* included in the size of the table. This makes it
925 easier to find the end of the table when we are handed a pointer
926 to some symbol in the middle of it. Zero out the fields in the
927 "null symbol" allocated at the end of the array. Note that the
928 symbol count does *not* include this null symbol, which is why it
929 is indexed by mcount and not mcount-1. */
931 SYMBOL_NAME (&msymbols
[mcount
]) = NULL
;
932 SYMBOL_VALUE_ADDRESS (&msymbols
[mcount
]) = 0;
933 MSYMBOL_INFO (&msymbols
[mcount
]) = NULL
;
934 MSYMBOL_TYPE (&msymbols
[mcount
]) = mst_unknown
;
935 SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols
[mcount
], language_unknown
);
937 /* Attach the minimal symbol table to the specified objfile.
938 The strings themselves are also located in the symbol_obstack
941 objfile
->minimal_symbol_count
= mcount
;
942 objfile
->msymbols
= msymbols
;
944 /* Now walk through all the minimal symbols, selecting the newly added
945 ones and attempting to cache their C++ demangled names. */
947 for (; mcount
-- > 0; msymbols
++)
949 SYMBOL_INIT_DEMANGLED_NAME (msymbols
, &objfile
->symbol_obstack
);
950 if (SYMBOL_DEMANGLED_NAME (msymbols
) != NULL
)
951 add_minsym_to_demangled_hash_table (msymbols
,
952 objfile
->msymbol_demangled_hash
);
957 /* Sort all the minimal symbols in OBJFILE. */
960 msymbols_sort (objfile
)
961 struct objfile
*objfile
;
963 qsort (objfile
->msymbols
, objfile
->minimal_symbol_count
,
964 sizeof (struct minimal_symbol
), compare_minimal_symbols
);
967 /* Check if PC is in a shared library trampoline code stub.
968 Return minimal symbol for the trampoline entry or NULL if PC is not
969 in a trampoline code stub. */
971 struct minimal_symbol
*
972 lookup_solib_trampoline_symbol_by_pc (pc
)
975 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (pc
);
977 if (msymbol
!= NULL
&& MSYMBOL_TYPE (msymbol
) == mst_solib_trampoline
)
982 /* If PC is in a shared library trampoline code stub, return the
983 address of the `real' function belonging to the stub.
984 Return 0 if PC is not in a trampoline code stub or if the real
985 function is not found in the minimal symbol table.
987 We may fail to find the right function if a function with the
988 same name is defined in more than one shared library, but this
989 is considered bad programming style. We could return 0 if we find
990 a duplicate function in case this matters someday. */
993 find_solib_trampoline_target (pc
)
996 struct objfile
*objfile
;
997 struct minimal_symbol
*msymbol
;
998 struct minimal_symbol
*tsymbol
= lookup_solib_trampoline_symbol_by_pc (pc
);
1000 if (tsymbol
!= NULL
)
1002 ALL_MSYMBOLS (objfile
, msymbol
)
1004 if (MSYMBOL_TYPE (msymbol
) == mst_text
1005 && STREQ (SYMBOL_NAME (msymbol
), SYMBOL_NAME (tsymbol
)))
1006 return SYMBOL_VALUE_ADDRESS (msymbol
);