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1ab3bf1b | 1 | /* GDB routines for manipulating the minimal symbol tables. |
02b40a19 | 2 | Copyright 1992, 1993, 1994, 1995 Free Software Foundation, Inc. |
1ab3bf1b JG |
3 | Contributed by Cygnus Support, using pieces from other GDB modules. |
4 | ||
5 | This file is part of GDB. | |
6 | ||
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. | |
11 | ||
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. | |
16 | ||
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 | |
6c9638b4 | 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
1ab3bf1b JG |
20 | |
21 | ||
22 | /* This file contains support routines for creating, manipulating, and | |
23 | destroying minimal symbol tables. | |
24 | ||
25 | Minimal symbol tables are used to hold some very basic information about | |
26 | all defined global symbols (text, data, bss, abs, etc). The only two | |
27 | required pieces of information are the symbol's name and the address | |
28 | associated with that symbol. | |
29 | ||
30 | In many cases, even if a file was compiled with no special options for | |
31 | debugging at all, as long as was not stripped it will contain sufficient | |
32 | information to build useful minimal symbol tables using this structure. | |
33 | ||
34 | Even when a file contains enough debugging information to build a full | |
35 | symbol table, these minimal symbols are still useful for quickly mapping | |
36 | between names and addresses, and vice versa. They are also sometimes used | |
37 | to figure out what full symbol table entries need to be read in. */ | |
38 | ||
39 | ||
1ab3bf1b | 40 | #include "defs.h" |
2b576293 | 41 | #include "gdb_string.h" |
1ab3bf1b JG |
42 | #include "symtab.h" |
43 | #include "bfd.h" | |
44 | #include "symfile.h" | |
5e2e79f8 | 45 | #include "objfiles.h" |
2e4964ad | 46 | #include "demangle.h" |
72bba93b | 47 | #include "gdb-stabs.h" |
1ab3bf1b JG |
48 | |
49 | /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. | |
50 | At the end, copy them all into one newly allocated location on an objfile's | |
51 | symbol obstack. */ | |
52 | ||
53 | #define BUNCH_SIZE 127 | |
54 | ||
55 | struct msym_bunch | |
56 | { | |
57 | struct msym_bunch *next; | |
58 | struct minimal_symbol contents[BUNCH_SIZE]; | |
59 | }; | |
60 | ||
61 | /* Bunch currently being filled up. | |
62 | The next field points to chain of filled bunches. */ | |
63 | ||
64 | static struct msym_bunch *msym_bunch; | |
65 | ||
66 | /* Number of slots filled in current bunch. */ | |
67 | ||
68 | static int msym_bunch_index; | |
69 | ||
70 | /* Total number of minimal symbols recorded so far for the objfile. */ | |
71 | ||
72 | static int msym_count; | |
73 | ||
74 | /* Prototypes for local functions. */ | |
75 | ||
76 | static int | |
77 | compare_minimal_symbols PARAMS ((const void *, const void *)); | |
78 | ||
79 | static int | |
80 | compact_minimal_symbols PARAMS ((struct minimal_symbol *, int)); | |
81 | ||
2d336b1b JK |
82 | /* Look through all the current minimal symbol tables and find the |
83 | first minimal symbol that matches NAME. If OBJF is non-NULL, limit | |
84 | the search to that objfile. If SFILE is non-NULL, limit the search | |
85 | to that source file. Returns a pointer to the minimal symbol that | |
86 | matches, or NULL if no match is found. | |
1ab3bf1b | 87 | |
507e4004 | 88 | Note: One instance where there may be duplicate minimal symbols with |
1ab3bf1b JG |
89 | the same name is when the symbol tables for a shared library and the |
90 | symbol tables for an executable contain global symbols with the same | |
91 | names (the dynamic linker deals with the duplication). */ | |
92 | ||
93 | struct minimal_symbol * | |
2d336b1b | 94 | lookup_minimal_symbol (name, sfile, objf) |
1ab3bf1b | 95 | register const char *name; |
2d336b1b | 96 | const char *sfile; |
1ab3bf1b JG |
97 | struct objfile *objf; |
98 | { | |
99 | struct objfile *objfile; | |
100 | struct minimal_symbol *msymbol; | |
101 | struct minimal_symbol *found_symbol = NULL; | |
164207ca | 102 | struct minimal_symbol *found_file_symbol = NULL; |
507e4004 | 103 | struct minimal_symbol *trampoline_symbol = NULL; |
1ab3bf1b | 104 | |
2d336b1b JK |
105 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
106 | if (sfile != NULL) | |
107 | { | |
108 | char *p = strrchr (sfile, '/'); | |
109 | if (p != NULL) | |
110 | sfile = p + 1; | |
111 | } | |
112 | #endif | |
113 | ||
1ab3bf1b JG |
114 | for (objfile = object_files; |
115 | objfile != NULL && found_symbol == NULL; | |
116 | objfile = objfile -> next) | |
117 | { | |
118 | if (objf == NULL || objf == objfile) | |
119 | { | |
120 | for (msymbol = objfile -> msymbols; | |
2e4964ad | 121 | msymbol != NULL && SYMBOL_NAME (msymbol) != NULL && |
1ab3bf1b JG |
122 | found_symbol == NULL; |
123 | msymbol++) | |
124 | { | |
2e4964ad | 125 | if (SYMBOL_MATCHES_NAME (msymbol, name)) |
1ab3bf1b | 126 | { |
164207ca JK |
127 | switch (MSYMBOL_TYPE (msymbol)) |
128 | { | |
129 | case mst_file_text: | |
130 | case mst_file_data: | |
131 | case mst_file_bss: | |
2d336b1b JK |
132 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
133 | if (sfile == NULL || STREQ (msymbol->filename, sfile)) | |
134 | found_file_symbol = msymbol; | |
135 | #else | |
136 | /* We have neither the ability nor the need to | |
137 | deal with the SFILE parameter. If we find | |
138 | more than one symbol, just return the latest | |
139 | one (the user can't expect useful behavior in | |
140 | that case). */ | |
164207ca | 141 | found_file_symbol = msymbol; |
2d336b1b | 142 | #endif |
164207ca JK |
143 | break; |
144 | ||
ae6d035d | 145 | case mst_solib_trampoline: |
164207ca JK |
146 | |
147 | /* If a trampoline symbol is found, we prefer to | |
148 | keep looking for the *real* symbol. If the | |
ae6d035d PS |
149 | actual symbol is not found, then we'll use the |
150 | trampoline entry. */ | |
164207ca JK |
151 | if (trampoline_symbol == NULL) |
152 | trampoline_symbol = msymbol; | |
153 | break; | |
ae6d035d PS |
154 | |
155 | case mst_unknown: | |
164207ca JK |
156 | default: |
157 | found_symbol = msymbol; | |
158 | break; | |
159 | } | |
1ab3bf1b JG |
160 | } |
161 | } | |
162 | } | |
163 | } | |
164207ca JK |
164 | /* External symbols are best. */ |
165 | if (found_symbol) | |
166 | return found_symbol; | |
167 | ||
168 | /* File-local symbols are next best. */ | |
169 | if (found_file_symbol) | |
170 | return found_file_symbol; | |
171 | ||
ae6d035d | 172 | /* Symbols for shared library trampolines are next best. */ |
164207ca JK |
173 | if (trampoline_symbol) |
174 | return trampoline_symbol; | |
507e4004 | 175 | |
164207ca | 176 | return NULL; |
1ab3bf1b JG |
177 | } |
178 | ||
cdd2212f KH |
179 | /* Look through all the current minimal symbol tables and find the |
180 | first minimal symbol that matches NAME and of text type. | |
181 | If OBJF is non-NULL, limit | |
182 | the search to that objfile. If SFILE is non-NULL, limit the search | |
183 | to that source file. Returns a pointer to the minimal symbol that | |
184 | matches, or NULL if no match is found. | |
185 | */ | |
186 | ||
187 | struct minimal_symbol * | |
188 | lookup_minimal_symbol_text (name, sfile, objf) | |
189 | register const char *name; | |
190 | const char *sfile; | |
191 | struct objfile *objf; | |
192 | { | |
193 | struct objfile *objfile; | |
194 | struct minimal_symbol *msymbol; | |
195 | struct minimal_symbol *found_symbol = NULL; | |
196 | struct minimal_symbol *found_file_symbol = NULL; | |
cdd2212f KH |
197 | |
198 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
199 | if (sfile != NULL) | |
200 | { | |
201 | char *p = strrchr (sfile, '/'); | |
202 | if (p != NULL) | |
203 | sfile = p + 1; | |
204 | } | |
205 | #endif | |
206 | ||
207 | for (objfile = object_files; | |
208 | objfile != NULL && found_symbol == NULL; | |
209 | objfile = objfile -> next) | |
210 | { | |
211 | if (objf == NULL || objf == objfile) | |
212 | { | |
213 | for (msymbol = objfile -> msymbols; | |
214 | msymbol != NULL && SYMBOL_NAME (msymbol) != NULL && | |
215 | found_symbol == NULL; | |
216 | msymbol++) | |
217 | { | |
218 | if (SYMBOL_MATCHES_NAME (msymbol, name) && | |
219 | (MSYMBOL_TYPE (msymbol) == mst_text || | |
220 | MSYMBOL_TYPE (msymbol) == mst_file_text)) | |
221 | { | |
222 | switch (MSYMBOL_TYPE (msymbol)) | |
223 | { | |
224 | case mst_file_text: | |
225 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
226 | if (sfile == NULL || STREQ (msymbol->filename, sfile)) | |
227 | found_file_symbol = msymbol; | |
228 | #else | |
229 | /* We have neither the ability nor the need to | |
230 | deal with the SFILE parameter. If we find | |
231 | more than one symbol, just return the latest | |
232 | one (the user can't expect useful behavior in | |
233 | that case). */ | |
234 | found_file_symbol = msymbol; | |
235 | #endif | |
236 | break; | |
237 | default: | |
238 | found_symbol = msymbol; | |
239 | break; | |
240 | } | |
241 | } | |
242 | } | |
243 | } | |
244 | } | |
245 | /* External symbols are best. */ | |
246 | if (found_symbol) | |
247 | return found_symbol; | |
248 | ||
249 | /* File-local symbols are next best. */ | |
250 | if (found_file_symbol) | |
251 | return found_file_symbol; | |
252 | ||
253 | return NULL; | |
254 | } | |
255 | ||
1ab3bf1b JG |
256 | |
257 | /* Search through the minimal symbol table for each objfile and find the | |
258 | symbol whose address is the largest address that is still less than or | |
259 | equal to PC. Returns a pointer to the minimal symbol if such a symbol | |
260 | is found, or NULL if PC is not in a suitable range. Note that we need | |
261 | to look through ALL the minimal symbol tables before deciding on the | |
55f65171 JK |
262 | symbol that comes closest to the specified PC. This is because objfiles |
263 | can overlap, for example objfile A has .text at 0x100 and .data at 0x40000 | |
264 | and objfile B has .text at 0x234 and .data at 0x40048. */ | |
1ab3bf1b JG |
265 | |
266 | struct minimal_symbol * | |
267 | lookup_minimal_symbol_by_pc (pc) | |
268 | register CORE_ADDR pc; | |
269 | { | |
270 | register int lo; | |
271 | register int hi; | |
272 | register int new; | |
273 | register struct objfile *objfile; | |
274 | register struct minimal_symbol *msymbol; | |
275 | register struct minimal_symbol *best_symbol = NULL; | |
276 | ||
277 | for (objfile = object_files; | |
278 | objfile != NULL; | |
279 | objfile = objfile -> next) | |
280 | { | |
281 | /* If this objfile has a minimal symbol table, go search it using | |
282 | a binary search. Note that a minimal symbol table always consists | |
283 | of at least two symbols, a "real" symbol and the terminating | |
284 | "null symbol". If there are no real symbols, then there is no | |
285 | minimal symbol table at all. */ | |
286 | ||
287 | if ((msymbol = objfile -> msymbols) != NULL) | |
288 | { | |
289 | lo = 0; | |
a521e93a | 290 | hi = objfile -> minimal_symbol_count - 1; |
9f1e14f4 | 291 | |
1ab3bf1b JG |
292 | /* This code assumes that the minimal symbols are sorted by |
293 | ascending address values. If the pc value is greater than or | |
294 | equal to the first symbol's address, then some symbol in this | |
295 | minimal symbol table is a suitable candidate for being the | |
296 | "best" symbol. This includes the last real symbol, for cases | |
297 | where the pc value is larger than any address in this vector. | |
298 | ||
299 | By iterating until the address associated with the current | |
300 | hi index (the endpoint of the test interval) is less than | |
301 | or equal to the desired pc value, we accomplish two things: | |
302 | (1) the case where the pc value is larger than any minimal | |
303 | symbol address is trivially solved, (2) the address associated | |
304 | with the hi index is always the one we want when the interation | |
305 | terminates. In essence, we are iterating the test interval | |
306 | down until the pc value is pushed out of it from the high end. | |
307 | ||
308 | Warning: this code is trickier than it would appear at first. */ | |
309 | ||
1eeba686 | 310 | /* Should also requires that pc is <= end of objfile. FIXME! */ |
2e4964ad | 311 | if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo])) |
1ab3bf1b | 312 | { |
2e4964ad | 313 | while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc) |
1ab3bf1b JG |
314 | { |
315 | /* pc is still strictly less than highest address */ | |
316 | /* Note "new" will always be >= lo */ | |
317 | new = (lo + hi) / 2; | |
2e4964ad FF |
318 | if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) || |
319 | (lo == new)) | |
1ab3bf1b JG |
320 | { |
321 | hi = new; | |
322 | } | |
323 | else | |
324 | { | |
325 | lo = new; | |
326 | } | |
327 | } | |
328 | /* The minimal symbol indexed by hi now is the best one in this | |
329 | objfile's minimal symbol table. See if it is the best one | |
330 | overall. */ | |
331 | ||
291b84ff JK |
332 | /* Skip any absolute symbols. This is apparently what adb |
333 | and dbx do, and is needed for the CM-5. There are two | |
334 | known possible problems: (1) on ELF, apparently end, edata, | |
335 | etc. are absolute. Not sure ignoring them here is a big | |
336 | deal, but if we want to use them, the fix would go in | |
337 | elfread.c. (2) I think shared library entry points on the | |
338 | NeXT are absolute. If we want special handling for this | |
339 | it probably should be triggered by a special | |
340 | mst_abs_or_lib or some such. */ | |
341 | while (hi >= 0 | |
342 | && msymbol[hi].type == mst_abs) | |
343 | --hi; | |
344 | ||
345 | if (hi >= 0 | |
346 | && ((best_symbol == NULL) || | |
347 | (SYMBOL_VALUE_ADDRESS (best_symbol) < | |
348 | SYMBOL_VALUE_ADDRESS (&msymbol[hi])))) | |
1ab3bf1b JG |
349 | { |
350 | best_symbol = &msymbol[hi]; | |
351 | } | |
352 | } | |
9f1e14f4 JK |
353 | } |
354 | } | |
355 | return (best_symbol); | |
356 | } | |
357 | ||
2d336b1b JK |
358 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
359 | CORE_ADDR | |
360 | find_stab_function_addr (namestring, pst, objfile) | |
361 | char *namestring; | |
362 | struct partial_symtab *pst; | |
363 | struct objfile *objfile; | |
364 | { | |
365 | struct minimal_symbol *msym; | |
366 | char *p; | |
367 | int n; | |
368 | ||
369 | p = strchr (namestring, ':'); | |
370 | if (p == NULL) | |
371 | p = namestring; | |
372 | n = p - namestring; | |
373 | p = alloca (n + 1); | |
374 | strncpy (p, namestring, n); | |
375 | p[n] = 0; | |
376 | ||
377 | msym = lookup_minimal_symbol (p, pst->filename, objfile); | |
378 | return msym == NULL ? 0 : SYMBOL_VALUE_ADDRESS (msym); | |
379 | } | |
380 | #endif /* SOFUN_ADDRESS_MAYBE_MISSING */ | |
381 | ||
382 | \f | |
02b40a19 PS |
383 | /* Return leading symbol character for a BFD. If BFD is NULL, |
384 | return the leading symbol character from the main objfile. */ | |
385 | ||
386 | static int get_symbol_leading_char PARAMS ((bfd *)); | |
387 | ||
388 | static int | |
389 | get_symbol_leading_char (abfd) | |
390 | bfd * abfd; | |
391 | { | |
392 | if (abfd != NULL) | |
393 | return bfd_get_symbol_leading_char (abfd); | |
394 | if (symfile_objfile != NULL && symfile_objfile->obfd != NULL) | |
395 | return bfd_get_symbol_leading_char (symfile_objfile->obfd); | |
396 | return 0; | |
397 | } | |
398 | ||
1ab3bf1b JG |
399 | /* Prepare to start collecting minimal symbols. Note that presetting |
400 | msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal | |
401 | symbol to allocate the memory for the first bunch. */ | |
402 | ||
403 | void | |
404 | init_minimal_symbol_collection () | |
405 | { | |
406 | msym_count = 0; | |
407 | msym_bunch = NULL; | |
408 | msym_bunch_index = BUNCH_SIZE; | |
409 | } | |
410 | ||
411 | void | |
8d60affd | 412 | prim_record_minimal_symbol (name, address, ms_type, objfile) |
1ab3bf1b JG |
413 | const char *name; |
414 | CORE_ADDR address; | |
415 | enum minimal_symbol_type ms_type; | |
8d60affd | 416 | struct objfile *objfile; |
1ab3bf1b | 417 | { |
ad15bea9 SG |
418 | int section; |
419 | ||
420 | switch (ms_type) | |
421 | { | |
422 | case mst_text: | |
423 | case mst_file_text: | |
424 | case mst_solib_trampoline: | |
425 | section = SECT_OFF_TEXT; | |
426 | break; | |
427 | case mst_data: | |
428 | case mst_file_data: | |
429 | section = SECT_OFF_DATA; | |
430 | break; | |
431 | case mst_bss: | |
432 | case mst_file_bss: | |
433 | section = SECT_OFF_BSS; | |
434 | break; | |
435 | default: | |
436 | section = -1; | |
437 | } | |
438 | ||
240972ec | 439 | prim_record_minimal_symbol_and_info (name, address, ms_type, |
ad15bea9 | 440 | NULL, section, objfile); |
1ab3bf1b JG |
441 | } |
442 | ||
2d336b1b JK |
443 | /* Record a minimal symbol in the msym bunches. Returns the symbol |
444 | newly created. */ | |
445 | struct minimal_symbol * | |
8d60affd JK |
446 | prim_record_minimal_symbol_and_info (name, address, ms_type, info, section, |
447 | objfile) | |
93297ea0 JG |
448 | const char *name; |
449 | CORE_ADDR address; | |
450 | enum minimal_symbol_type ms_type; | |
451 | char *info; | |
3c02636b | 452 | int section; |
8d60affd | 453 | struct objfile *objfile; |
93297ea0 JG |
454 | { |
455 | register struct msym_bunch *new; | |
2e4964ad | 456 | register struct minimal_symbol *msymbol; |
93297ea0 | 457 | |
404f69a8 JK |
458 | if (ms_type == mst_file_text) |
459 | { | |
460 | /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into | |
461 | the minimal symbols, because if there is also another symbol | |
462 | at the same address (e.g. the first function of the file), | |
463 | lookup_minimal_symbol_by_pc would have no way of getting the | |
464 | right one. */ | |
465 | if (name[0] == 'g' | |
466 | && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0 | |
467 | || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0)) | |
6b14af2b | 468 | return (NULL); |
404f69a8 JK |
469 | |
470 | { | |
ab5f7971 | 471 | const char *tempstring = name; |
02b40a19 | 472 | if (tempstring[0] == get_symbol_leading_char (objfile->obfd)) |
404f69a8 JK |
473 | ++tempstring; |
474 | if (STREQN (tempstring, "__gnu_compiled", 14)) | |
6b14af2b | 475 | return (NULL); |
404f69a8 JK |
476 | } |
477 | } | |
478 | ||
93297ea0 JG |
479 | if (msym_bunch_index == BUNCH_SIZE) |
480 | { | |
481 | new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch)); | |
482 | msym_bunch_index = 0; | |
483 | new -> next = msym_bunch; | |
484 | msym_bunch = new; | |
485 | } | |
2e4964ad FF |
486 | msymbol = &msym_bunch -> contents[msym_bunch_index]; |
487 | SYMBOL_NAME (msymbol) = (char *) name; | |
7532cf10 | 488 | SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown); |
2e4964ad | 489 | SYMBOL_VALUE_ADDRESS (msymbol) = address; |
ad15bea9 | 490 | SYMBOL_SECTION (msymbol) = section; |
72bba93b | 491 | |
2e4964ad FF |
492 | MSYMBOL_TYPE (msymbol) = ms_type; |
493 | /* FIXME: This info, if it remains, needs its own field. */ | |
494 | MSYMBOL_INFO (msymbol) = info; /* FIXME! */ | |
93297ea0 JG |
495 | msym_bunch_index++; |
496 | msym_count++; | |
2d336b1b | 497 | return msymbol; |
93297ea0 JG |
498 | } |
499 | ||
1ab3bf1b JG |
500 | /* Compare two minimal symbols by address and return a signed result based |
501 | on unsigned comparisons, so that we sort into unsigned numeric order. */ | |
502 | ||
503 | static int | |
504 | compare_minimal_symbols (fn1p, fn2p) | |
505 | const PTR fn1p; | |
506 | const PTR fn2p; | |
507 | { | |
508 | register const struct minimal_symbol *fn1; | |
509 | register const struct minimal_symbol *fn2; | |
510 | ||
511 | fn1 = (const struct minimal_symbol *) fn1p; | |
512 | fn2 = (const struct minimal_symbol *) fn2p; | |
513 | ||
2e4964ad | 514 | if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2)) |
1ab3bf1b JG |
515 | { |
516 | return (-1); | |
517 | } | |
2e4964ad | 518 | else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2)) |
1ab3bf1b JG |
519 | { |
520 | return (1); | |
521 | } | |
522 | else | |
523 | { | |
524 | return (0); | |
525 | } | |
526 | } | |
527 | ||
528 | /* Discard the currently collected minimal symbols, if any. If we wish | |
529 | to save them for later use, we must have already copied them somewhere | |
530 | else before calling this function. | |
531 | ||
532 | FIXME: We could allocate the minimal symbol bunches on their own | |
533 | obstack and then simply blow the obstack away when we are done with | |
534 | it. Is it worth the extra trouble though? */ | |
535 | ||
536 | /* ARGSUSED */ | |
537 | void | |
538 | discard_minimal_symbols (foo) | |
539 | int foo; | |
540 | { | |
541 | register struct msym_bunch *next; | |
542 | ||
543 | while (msym_bunch != NULL) | |
544 | { | |
545 | next = msym_bunch -> next; | |
84ffdec2 | 546 | free ((PTR)msym_bunch); |
1ab3bf1b JG |
547 | msym_bunch = next; |
548 | } | |
549 | } | |
550 | ||
551 | /* Compact duplicate entries out of a minimal symbol table by walking | |
552 | through the table and compacting out entries with duplicate addresses | |
021959e2 JG |
553 | and matching names. Return the number of entries remaining. |
554 | ||
555 | On entry, the table resides between msymbol[0] and msymbol[mcount]. | |
556 | On exit, it resides between msymbol[0] and msymbol[result_count]. | |
1ab3bf1b JG |
557 | |
558 | When files contain multiple sources of symbol information, it is | |
559 | possible for the minimal symbol table to contain many duplicate entries. | |
560 | As an example, SVR4 systems use ELF formatted object files, which | |
561 | usually contain at least two different types of symbol tables (a | |
562 | standard ELF one and a smaller dynamic linking table), as well as | |
563 | DWARF debugging information for files compiled with -g. | |
564 | ||
565 | Without compacting, the minimal symbol table for gdb itself contains | |
566 | over a 1000 duplicates, about a third of the total table size. Aside | |
567 | from the potential trap of not noticing that two successive entries | |
568 | identify the same location, this duplication impacts the time required | |
021959e2 | 569 | to linearly scan the table, which is done in a number of places. So we |
1ab3bf1b JG |
570 | just do one linear scan here and toss out the duplicates. |
571 | ||
572 | Note that we are not concerned here about recovering the space that | |
573 | is potentially freed up, because the strings themselves are allocated | |
574 | on the symbol_obstack, and will get automatically freed when the symbol | |
021959e2 JG |
575 | table is freed. The caller can free up the unused minimal symbols at |
576 | the end of the compacted region if their allocation strategy allows it. | |
1ab3bf1b JG |
577 | |
578 | Also note we only go up to the next to last entry within the loop | |
579 | and then copy the last entry explicitly after the loop terminates. | |
580 | ||
581 | Since the different sources of information for each symbol may | |
582 | have different levels of "completeness", we may have duplicates | |
583 | that have one entry with type "mst_unknown" and the other with a | |
584 | known type. So if the one we are leaving alone has type mst_unknown, | |
585 | overwrite its type with the type from the one we are compacting out. */ | |
586 | ||
587 | static int | |
588 | compact_minimal_symbols (msymbol, mcount) | |
589 | struct minimal_symbol *msymbol; | |
590 | int mcount; | |
591 | { | |
592 | struct minimal_symbol *copyfrom; | |
593 | struct minimal_symbol *copyto; | |
594 | ||
595 | if (mcount > 0) | |
596 | { | |
597 | copyfrom = copyto = msymbol; | |
598 | while (copyfrom < msymbol + mcount - 1) | |
599 | { | |
2e4964ad FF |
600 | if (SYMBOL_VALUE_ADDRESS (copyfrom) == |
601 | SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) && | |
602 | (STREQ (SYMBOL_NAME (copyfrom), SYMBOL_NAME ((copyfrom + 1))))) | |
1ab3bf1b | 603 | { |
2e4964ad | 604 | if (MSYMBOL_TYPE((copyfrom + 1)) == mst_unknown) |
1ab3bf1b | 605 | { |
2e4964ad | 606 | MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom); |
1ab3bf1b JG |
607 | } |
608 | copyfrom++; | |
609 | } | |
610 | else | |
611 | { | |
612 | *copyto++ = *copyfrom++; | |
613 | } | |
614 | } | |
615 | *copyto++ = *copyfrom++; | |
616 | mcount = copyto - msymbol; | |
617 | } | |
618 | return (mcount); | |
619 | } | |
620 | ||
2e4964ad FF |
621 | /* Add the minimal symbols in the existing bunches to the objfile's official |
622 | minimal symbol table. In most cases there is no minimal symbol table yet | |
623 | for this objfile, and the existing bunches are used to create one. Once | |
624 | in a while (for shared libraries for example), we add symbols (e.g. common | |
625 | symbols) to an existing objfile. | |
626 | ||
627 | Because of the way minimal symbols are collected, we generally have no way | |
628 | of knowing what source language applies to any particular minimal symbol. | |
629 | Specifically, we have no way of knowing if the minimal symbol comes from a | |
630 | C++ compilation unit or not. So for the sake of supporting cached | |
631 | demangled C++ names, we have no choice but to try and demangle each new one | |
632 | that comes in. If the demangling succeeds, then we assume it is a C++ | |
633 | symbol and set the symbol's language and demangled name fields | |
634 | appropriately. Note that in order to avoid unnecessary demanglings, and | |
635 | allocating obstack space that subsequently can't be freed for the demangled | |
636 | names, we mark all newly added symbols with language_auto. After | |
637 | compaction of the minimal symbols, we go back and scan the entire minimal | |
638 | symbol table looking for these new symbols. For each new symbol we attempt | |
639 | to demangle it, and if successful, record it as a language_cplus symbol | |
640 | and cache the demangled form on the symbol obstack. Symbols which don't | |
641 | demangle are marked as language_unknown symbols, which inhibits future | |
642 | attempts to demangle them if we later add more minimal symbols. */ | |
1ab3bf1b JG |
643 | |
644 | void | |
021959e2 | 645 | install_minimal_symbols (objfile) |
1ab3bf1b JG |
646 | struct objfile *objfile; |
647 | { | |
648 | register int bindex; | |
649 | register int mcount; | |
650 | register struct msym_bunch *bunch; | |
651 | register struct minimal_symbol *msymbols; | |
021959e2 | 652 | int alloc_count; |
de9bef49 | 653 | register char leading_char; |
1ab3bf1b JG |
654 | |
655 | if (msym_count > 0) | |
656 | { | |
021959e2 JG |
657 | /* Allocate enough space in the obstack, into which we will gather the |
658 | bunches of new and existing minimal symbols, sort them, and then | |
659 | compact out the duplicate entries. Once we have a final table, | |
660 | we will give back the excess space. */ | |
661 | ||
662 | alloc_count = msym_count + objfile->minimal_symbol_count + 1; | |
663 | obstack_blank (&objfile->symbol_obstack, | |
664 | alloc_count * sizeof (struct minimal_symbol)); | |
1ab3bf1b | 665 | msymbols = (struct minimal_symbol *) |
021959e2 JG |
666 | obstack_base (&objfile->symbol_obstack); |
667 | ||
668 | /* Copy in the existing minimal symbols, if there are any. */ | |
669 | ||
670 | if (objfile->minimal_symbol_count) | |
671 | memcpy ((char *)msymbols, (char *)objfile->msymbols, | |
672 | objfile->minimal_symbol_count * sizeof (struct minimal_symbol)); | |
673 | ||
1ab3bf1b JG |
674 | /* Walk through the list of minimal symbol bunches, adding each symbol |
675 | to the new contiguous array of symbols. Note that we start with the | |
676 | current, possibly partially filled bunch (thus we use the current | |
677 | msym_bunch_index for the first bunch we copy over), and thereafter | |
678 | each bunch is full. */ | |
679 | ||
021959e2 | 680 | mcount = objfile->minimal_symbol_count; |
02b40a19 | 681 | leading_char = get_symbol_leading_char (objfile->obfd); |
021959e2 | 682 | |
1ab3bf1b JG |
683 | for (bunch = msym_bunch; bunch != NULL; bunch = bunch -> next) |
684 | { | |
685 | for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++) | |
686 | { | |
687 | msymbols[mcount] = bunch -> contents[bindex]; | |
2e4964ad FF |
688 | SYMBOL_LANGUAGE (&msymbols[mcount]) = language_auto; |
689 | if (SYMBOL_NAME (&msymbols[mcount])[0] == leading_char) | |
1ab3bf1b | 690 | { |
2e4964ad | 691 | SYMBOL_NAME(&msymbols[mcount])++; |
1ab3bf1b | 692 | } |
1ab3bf1b JG |
693 | } |
694 | msym_bunch_index = BUNCH_SIZE; | |
695 | } | |
021959e2 | 696 | |
1ab3bf1b JG |
697 | /* Sort the minimal symbols by address. */ |
698 | ||
699 | qsort (msymbols, mcount, sizeof (struct minimal_symbol), | |
700 | compare_minimal_symbols); | |
701 | ||
021959e2 JG |
702 | /* Compact out any duplicates, and free up whatever space we are |
703 | no longer using. */ | |
1ab3bf1b JG |
704 | |
705 | mcount = compact_minimal_symbols (msymbols, mcount); | |
1ab3bf1b | 706 | |
021959e2 JG |
707 | obstack_blank (&objfile->symbol_obstack, |
708 | (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol)); | |
709 | msymbols = (struct minimal_symbol *) | |
710 | obstack_finish (&objfile->symbol_obstack); | |
711 | ||
2e4964ad FF |
712 | /* We also terminate the minimal symbol table with a "null symbol", |
713 | which is *not* included in the size of the table. This makes it | |
714 | easier to find the end of the table when we are handed a pointer | |
715 | to some symbol in the middle of it. Zero out the fields in the | |
716 | "null symbol" allocated at the end of the array. Note that the | |
717 | symbol count does *not* include this null symbol, which is why it | |
718 | is indexed by mcount and not mcount-1. */ | |
719 | ||
720 | SYMBOL_NAME (&msymbols[mcount]) = NULL; | |
721 | SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0; | |
722 | MSYMBOL_INFO (&msymbols[mcount]) = NULL; | |
723 | MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown; | |
7532cf10 | 724 | SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown); |
021959e2 JG |
725 | |
726 | /* Attach the minimal symbol table to the specified objfile. | |
727 | The strings themselves are also located in the symbol_obstack | |
728 | of this objfile. */ | |
729 | ||
730 | objfile -> minimal_symbol_count = mcount; | |
731 | objfile -> msymbols = msymbols; | |
2e4964ad FF |
732 | |
733 | /* Now walk through all the minimal symbols, selecting the newly added | |
734 | ones and attempting to cache their C++ demangled names. */ | |
735 | ||
736 | for ( ; mcount-- > 0 ; msymbols++) | |
737 | { | |
7532cf10 | 738 | SYMBOL_INIT_DEMANGLED_NAME (msymbols, &objfile->symbol_obstack); |
2e4964ad | 739 | } |
1ab3bf1b JG |
740 | } |
741 | } | |
742 | ||
3a470454 JK |
743 | /* Sort all the minimal symbols in OBJFILE. */ |
744 | ||
745 | void | |
746 | msymbols_sort (objfile) | |
747 | struct objfile *objfile; | |
748 | { | |
749 | qsort (objfile->msymbols, objfile->minimal_symbol_count, | |
750 | sizeof (struct minimal_symbol), compare_minimal_symbols); | |
751 | } | |
752 | ||
2fe3b329 PS |
753 | /* Check if PC is in a shared library trampoline code stub. |
754 | Return minimal symbol for the trampoline entry or NULL if PC is not | |
755 | in a trampoline code stub. */ | |
756 | ||
757 | struct minimal_symbol * | |
758 | lookup_solib_trampoline_symbol_by_pc (pc) | |
759 | CORE_ADDR pc; | |
760 | { | |
761 | struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc); | |
762 | ||
763 | if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) | |
764 | return msymbol; | |
765 | return NULL; | |
766 | } | |
767 | ||
768 | /* If PC is in a shared library trampoline code stub, return the | |
769 | address of the `real' function belonging to the stub. | |
770 | Return 0 if PC is not in a trampoline code stub or if the real | |
771 | function is not found in the minimal symbol table. | |
772 | ||
773 | We may fail to find the right function if a function with the | |
774 | same name is defined in more than one shared library, but this | |
775 | is considered bad programming style. We could return 0 if we find | |
776 | a duplicate function in case this matters someday. */ | |
777 | ||
778 | CORE_ADDR | |
779 | find_solib_trampoline_target (pc) | |
780 | CORE_ADDR pc; | |
781 | { | |
782 | struct objfile *objfile; | |
783 | struct minimal_symbol *msymbol; | |
784 | struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc); | |
785 | ||
786 | if (tsymbol != NULL) | |
787 | { | |
788 | ALL_MSYMBOLS (objfile, msymbol) | |
789 | { | |
790 | if (MSYMBOL_TYPE (msymbol) == mst_text | |
791 | && STREQ (SYMBOL_NAME (msymbol), SYMBOL_NAME (tsymbol))) | |
792 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
793 | } | |
794 | } | |
795 | return 0; | |
796 | } | |
797 |