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c906108c | 1 | /* GDB routines for manipulating the minimal symbol tables. |
197e01b6 | 2 | Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, |
7b6bb8da JB |
3 | 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011 |
4 | Free Software Foundation, Inc. | |
c906108c SS |
5 | Contributed by Cygnus Support, using pieces from other GDB modules. |
6 | ||
c5aa993b | 7 | This file is part of GDB. |
c906108c | 8 | |
c5aa993b JM |
9 | This program is free software; you can redistribute it and/or modify |
10 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 12 | (at your option) any later version. |
c906108c | 13 | |
c5aa993b JM |
14 | This program is distributed in the hope that it will be useful, |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
c906108c | 18 | |
c5aa993b | 19 | You should have received a copy of the GNU General Public License |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c SS |
21 | |
22 | ||
23 | /* This file contains support routines for creating, manipulating, and | |
24 | destroying minimal symbol tables. | |
25 | ||
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. | |
30 | ||
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. | |
c5aa993b | 34 | |
c906108c SS |
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 | |
025bb325 | 38 | to figure out what full symbol table entries need to be read in. */ |
c906108c SS |
39 | |
40 | ||
41 | #include "defs.h" | |
9227b5eb | 42 | #include <ctype.h> |
c906108c SS |
43 | #include "gdb_string.h" |
44 | #include "symtab.h" | |
45 | #include "bfd.h" | |
0ba1096a | 46 | #include "filenames.h" |
c906108c SS |
47 | #include "symfile.h" |
48 | #include "objfiles.h" | |
49 | #include "demangle.h" | |
7ed49443 JB |
50 | #include "value.h" |
51 | #include "cp-abi.h" | |
42848c96 | 52 | #include "target.h" |
71c25dea TT |
53 | #include "cp-support.h" |
54 | #include "language.h" | |
c906108c SS |
55 | |
56 | /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. | |
57 | At the end, copy them all into one newly allocated location on an objfile's | |
58 | symbol obstack. */ | |
59 | ||
60 | #define BUNCH_SIZE 127 | |
61 | ||
62 | struct msym_bunch | |
c5aa993b JM |
63 | { |
64 | struct msym_bunch *next; | |
65 | struct minimal_symbol contents[BUNCH_SIZE]; | |
66 | }; | |
c906108c SS |
67 | |
68 | /* Bunch currently being filled up. | |
69 | The next field points to chain of filled bunches. */ | |
70 | ||
71 | static struct msym_bunch *msym_bunch; | |
72 | ||
73 | /* Number of slots filled in current bunch. */ | |
74 | ||
75 | static int msym_bunch_index; | |
76 | ||
77 | /* Total number of minimal symbols recorded so far for the objfile. */ | |
78 | ||
79 | static int msym_count; | |
80 | ||
9227b5eb JB |
81 | /* Compute a hash code based using the same criteria as `strcmp_iw'. */ |
82 | ||
83 | unsigned int | |
84 | msymbol_hash_iw (const char *string) | |
85 | { | |
86 | unsigned int hash = 0; | |
b8d56208 | 87 | |
9227b5eb JB |
88 | while (*string && *string != '(') |
89 | { | |
90 | while (isspace (*string)) | |
91 | ++string; | |
92 | if (*string && *string != '(') | |
375f3d86 | 93 | { |
59d7bcaf | 94 | hash = SYMBOL_HASH_NEXT (hash, *string); |
375f3d86 DJ |
95 | ++string; |
96 | } | |
9227b5eb | 97 | } |
261397f8 | 98 | return hash; |
9227b5eb JB |
99 | } |
100 | ||
101 | /* Compute a hash code for a string. */ | |
102 | ||
103 | unsigned int | |
104 | msymbol_hash (const char *string) | |
105 | { | |
106 | unsigned int hash = 0; | |
b8d56208 | 107 | |
9227b5eb | 108 | for (; *string; ++string) |
59d7bcaf | 109 | hash = SYMBOL_HASH_NEXT (hash, *string); |
261397f8 | 110 | return hash; |
9227b5eb JB |
111 | } |
112 | ||
113 | /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */ | |
114 | void | |
115 | add_minsym_to_hash_table (struct minimal_symbol *sym, | |
116 | struct minimal_symbol **table) | |
117 | { | |
118 | if (sym->hash_next == NULL) | |
119 | { | |
f56f77c1 DC |
120 | unsigned int hash |
121 | = msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE; | |
b8d56208 | 122 | |
9227b5eb JB |
123 | sym->hash_next = table[hash]; |
124 | table[hash] = sym; | |
125 | } | |
126 | } | |
127 | ||
0729fd50 DB |
128 | /* Add the minimal symbol SYM to an objfile's minsym demangled hash table, |
129 | TABLE. */ | |
130 | static void | |
131 | add_minsym_to_demangled_hash_table (struct minimal_symbol *sym, | |
132 | struct minimal_symbol **table) | |
133 | { | |
134 | if (sym->demangled_hash_next == NULL) | |
135 | { | |
3e43a32a MS |
136 | unsigned int hash = msymbol_hash_iw (SYMBOL_SEARCH_NAME (sym)) |
137 | % MINIMAL_SYMBOL_HASH_SIZE; | |
b8d56208 | 138 | |
0729fd50 DB |
139 | sym->demangled_hash_next = table[hash]; |
140 | table[hash] = sym; | |
141 | } | |
142 | } | |
143 | ||
c906108c | 144 | |
bccdca4a UW |
145 | /* Return OBJFILE where minimal symbol SYM is defined. */ |
146 | struct objfile * | |
147 | msymbol_objfile (struct minimal_symbol *sym) | |
148 | { | |
149 | struct objfile *objf; | |
150 | struct minimal_symbol *tsym; | |
151 | ||
152 | unsigned int hash | |
153 | = msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE; | |
154 | ||
155 | for (objf = object_files; objf; objf = objf->next) | |
156 | for (tsym = objf->msymbol_hash[hash]; tsym; tsym = tsym->hash_next) | |
157 | if (tsym == sym) | |
158 | return objf; | |
159 | ||
160 | /* We should always be able to find the objfile ... */ | |
161 | internal_error (__FILE__, __LINE__, _("failed internal consistency check")); | |
162 | } | |
163 | ||
164 | ||
c906108c SS |
165 | /* Look through all the current minimal symbol tables and find the |
166 | first minimal symbol that matches NAME. If OBJF is non-NULL, limit | |
72a5efb3 DJ |
167 | the search to that objfile. If SFILE is non-NULL, the only file-scope |
168 | symbols considered will be from that source file (global symbols are | |
169 | still preferred). Returns a pointer to the minimal symbol that | |
c906108c SS |
170 | matches, or NULL if no match is found. |
171 | ||
172 | Note: One instance where there may be duplicate minimal symbols with | |
173 | the same name is when the symbol tables for a shared library and the | |
174 | symbol tables for an executable contain global symbols with the same | |
d73f140a JB |
175 | names (the dynamic linker deals with the duplication). |
176 | ||
177 | It's also possible to have minimal symbols with different mangled | |
178 | names, but identical demangled names. For example, the GNU C++ v3 | |
179 | ABI requires the generation of two (or perhaps three) copies of | |
180 | constructor functions --- "in-charge", "not-in-charge", and | |
181 | "allocate" copies; destructors may be duplicated as well. | |
182 | Obviously, there must be distinct mangled names for each of these, | |
183 | but the demangled names are all the same: S::S or S::~S. */ | |
c906108c SS |
184 | |
185 | struct minimal_symbol * | |
aa1ee363 | 186 | lookup_minimal_symbol (const char *name, const char *sfile, |
fba45db2 | 187 | struct objfile *objf) |
c906108c SS |
188 | { |
189 | struct objfile *objfile; | |
190 | struct minimal_symbol *msymbol; | |
191 | struct minimal_symbol *found_symbol = NULL; | |
192 | struct minimal_symbol *found_file_symbol = NULL; | |
193 | struct minimal_symbol *trampoline_symbol = NULL; | |
194 | ||
261397f8 DJ |
195 | unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
196 | unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE; | |
9227b5eb | 197 | |
71c25dea TT |
198 | int needtofreename = 0; |
199 | const char *modified_name; | |
200 | ||
c906108c | 201 | if (sfile != NULL) |
9f37bbcc | 202 | sfile = lbasename (sfile); |
c906108c | 203 | |
025bb325 | 204 | /* For C++, canonicalize the input name. */ |
71c25dea TT |
205 | modified_name = name; |
206 | if (current_language->la_language == language_cplus) | |
207 | { | |
208 | char *cname = cp_canonicalize_string (name); | |
b8d56208 | 209 | |
71c25dea TT |
210 | if (cname) |
211 | { | |
212 | modified_name = cname; | |
213 | needtofreename = 1; | |
214 | } | |
215 | } | |
216 | ||
c906108c SS |
217 | for (objfile = object_files; |
218 | objfile != NULL && found_symbol == NULL; | |
c5aa993b | 219 | objfile = objfile->next) |
c906108c | 220 | { |
56e3f43c | 221 | if (objf == NULL || objf == objfile |
15d123c9 | 222 | || objf == objfile->separate_debug_objfile_backlink) |
c906108c | 223 | { |
9227b5eb JB |
224 | /* Do two passes: the first over the ordinary hash table, |
225 | and the second over the demangled hash table. */ | |
0729fd50 | 226 | int pass; |
9227b5eb | 227 | |
0729fd50 | 228 | for (pass = 1; pass <= 2 && found_symbol == NULL; pass++) |
c906108c | 229 | { |
0729fd50 DB |
230 | /* Select hash list according to pass. */ |
231 | if (pass == 1) | |
232 | msymbol = objfile->msymbol_hash[hash]; | |
233 | else | |
234 | msymbol = objfile->msymbol_demangled_hash[dem_hash]; | |
235 | ||
236 | while (msymbol != NULL && found_symbol == NULL) | |
c906108c | 237 | { |
3567439c DJ |
238 | int match; |
239 | ||
240 | if (pass == 1) | |
71c25dea | 241 | { |
559a7a62 JK |
242 | int (*cmp) (const char *, const char *); |
243 | ||
244 | cmp = (case_sensitivity == case_sensitive_on | |
245 | ? strcmp : strcasecmp); | |
246 | match = cmp (SYMBOL_LINKAGE_NAME (msymbol), | |
247 | modified_name) == 0; | |
71c25dea | 248 | } |
3567439c | 249 | else |
71c25dea | 250 | { |
559a7a62 | 251 | /* The function respects CASE_SENSITIVITY. */ |
71c25dea TT |
252 | match = SYMBOL_MATCHES_SEARCH_NAME (msymbol, |
253 | modified_name); | |
254 | } | |
255 | ||
3567439c | 256 | if (match) |
c906108c | 257 | { |
0729fd50 DB |
258 | switch (MSYMBOL_TYPE (msymbol)) |
259 | { | |
260 | case mst_file_text: | |
261 | case mst_file_data: | |
262 | case mst_file_bss: | |
6314a349 | 263 | if (sfile == NULL |
0ba1096a | 264 | || filename_cmp (msymbol->filename, sfile) == 0) |
0729fd50 | 265 | found_file_symbol = msymbol; |
0729fd50 DB |
266 | break; |
267 | ||
268 | case mst_solib_trampoline: | |
269 | ||
270 | /* If a trampoline symbol is found, we prefer to | |
025bb325 | 271 | keep looking for the *real* symbol. If the |
0729fd50 | 272 | actual symbol is not found, then we'll use the |
025bb325 | 273 | trampoline entry. */ |
0729fd50 DB |
274 | if (trampoline_symbol == NULL) |
275 | trampoline_symbol = msymbol; | |
276 | break; | |
277 | ||
278 | case mst_unknown: | |
279 | default: | |
280 | found_symbol = msymbol; | |
281 | break; | |
282 | } | |
c906108c | 283 | } |
9227b5eb | 284 | |
0729fd50 DB |
285 | /* Find the next symbol on the hash chain. */ |
286 | if (pass == 1) | |
287 | msymbol = msymbol->hash_next; | |
288 | else | |
289 | msymbol = msymbol->demangled_hash_next; | |
9227b5eb | 290 | } |
c906108c SS |
291 | } |
292 | } | |
293 | } | |
71c25dea TT |
294 | |
295 | if (needtofreename) | |
296 | xfree ((void *) modified_name); | |
297 | ||
c906108c SS |
298 | /* External symbols are best. */ |
299 | if (found_symbol) | |
300 | return found_symbol; | |
301 | ||
302 | /* File-local symbols are next best. */ | |
303 | if (found_file_symbol) | |
304 | return found_file_symbol; | |
305 | ||
306 | /* Symbols for shared library trampolines are next best. */ | |
307 | if (trampoline_symbol) | |
308 | return trampoline_symbol; | |
309 | ||
310 | return NULL; | |
311 | } | |
312 | ||
313 | /* Look through all the current minimal symbol tables and find the | |
72a5efb3 | 314 | first minimal symbol that matches NAME and has text type. If OBJF |
5520a790 EZ |
315 | is non-NULL, limit the search to that objfile. Returns a pointer |
316 | to the minimal symbol that matches, or NULL if no match is found. | |
72a5efb3 DJ |
317 | |
318 | This function only searches the mangled (linkage) names. */ | |
c5aa993b | 319 | |
c906108c | 320 | struct minimal_symbol * |
5520a790 | 321 | lookup_minimal_symbol_text (const char *name, struct objfile *objf) |
c906108c SS |
322 | { |
323 | struct objfile *objfile; | |
324 | struct minimal_symbol *msymbol; | |
325 | struct minimal_symbol *found_symbol = NULL; | |
326 | struct minimal_symbol *found_file_symbol = NULL; | |
327 | ||
72a5efb3 DJ |
328 | unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
329 | ||
c906108c SS |
330 | for (objfile = object_files; |
331 | objfile != NULL && found_symbol == NULL; | |
c5aa993b | 332 | objfile = objfile->next) |
c906108c | 333 | { |
56e3f43c | 334 | if (objf == NULL || objf == objfile |
15d123c9 | 335 | || objf == objfile->separate_debug_objfile_backlink) |
c906108c | 336 | { |
72a5efb3 DJ |
337 | for (msymbol = objfile->msymbol_hash[hash]; |
338 | msymbol != NULL && found_symbol == NULL; | |
339 | msymbol = msymbol->hash_next) | |
c906108c | 340 | { |
f56f77c1 | 341 | if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 && |
0875794a JK |
342 | (MSYMBOL_TYPE (msymbol) == mst_text |
343 | || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc | |
344 | || MSYMBOL_TYPE (msymbol) == mst_file_text)) | |
c906108c SS |
345 | { |
346 | switch (MSYMBOL_TYPE (msymbol)) | |
347 | { | |
348 | case mst_file_text: | |
c906108c | 349 | found_file_symbol = msymbol; |
c906108c SS |
350 | break; |
351 | default: | |
352 | found_symbol = msymbol; | |
353 | break; | |
354 | } | |
355 | } | |
356 | } | |
357 | } | |
358 | } | |
359 | /* External symbols are best. */ | |
360 | if (found_symbol) | |
361 | return found_symbol; | |
362 | ||
363 | /* File-local symbols are next best. */ | |
364 | if (found_file_symbol) | |
365 | return found_file_symbol; | |
366 | ||
367 | return NULL; | |
368 | } | |
369 | ||
907fc202 UW |
370 | /* Look through all the current minimal symbol tables and find the |
371 | first minimal symbol that matches NAME and PC. If OBJF is non-NULL, | |
372 | limit the search to that objfile. Returns a pointer to the minimal | |
373 | symbol that matches, or NULL if no match is found. */ | |
374 | ||
375 | struct minimal_symbol * | |
376 | lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name, | |
377 | struct objfile *objf) | |
378 | { | |
379 | struct objfile *objfile; | |
380 | struct minimal_symbol *msymbol; | |
381 | ||
382 | unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; | |
383 | ||
384 | for (objfile = object_files; | |
385 | objfile != NULL; | |
386 | objfile = objfile->next) | |
387 | { | |
388 | if (objf == NULL || objf == objfile | |
15d123c9 | 389 | || objf == objfile->separate_debug_objfile_backlink) |
907fc202 UW |
390 | { |
391 | for (msymbol = objfile->msymbol_hash[hash]; | |
392 | msymbol != NULL; | |
393 | msymbol = msymbol->hash_next) | |
394 | { | |
395 | if (SYMBOL_VALUE_ADDRESS (msymbol) == pc | |
396 | && strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0) | |
397 | return msymbol; | |
398 | } | |
399 | } | |
400 | } | |
401 | ||
402 | return NULL; | |
403 | } | |
404 | ||
c906108c | 405 | /* Look through all the current minimal symbol tables and find the |
5520a790 EZ |
406 | first minimal symbol that matches NAME and is a solib trampoline. |
407 | If OBJF is non-NULL, limit the search to that objfile. Returns a | |
408 | pointer to the minimal symbol that matches, or NULL if no match is | |
409 | found. | |
72a5efb3 DJ |
410 | |
411 | This function only searches the mangled (linkage) names. */ | |
c5aa993b | 412 | |
c906108c | 413 | struct minimal_symbol * |
aa1ee363 | 414 | lookup_minimal_symbol_solib_trampoline (const char *name, |
aa1ee363 | 415 | struct objfile *objf) |
c906108c SS |
416 | { |
417 | struct objfile *objfile; | |
418 | struct minimal_symbol *msymbol; | |
419 | struct minimal_symbol *found_symbol = NULL; | |
420 | ||
72a5efb3 DJ |
421 | unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
422 | ||
c906108c SS |
423 | for (objfile = object_files; |
424 | objfile != NULL && found_symbol == NULL; | |
c5aa993b | 425 | objfile = objfile->next) |
c906108c | 426 | { |
56e3f43c | 427 | if (objf == NULL || objf == objfile |
15d123c9 | 428 | || objf == objfile->separate_debug_objfile_backlink) |
c906108c | 429 | { |
72a5efb3 DJ |
430 | for (msymbol = objfile->msymbol_hash[hash]; |
431 | msymbol != NULL && found_symbol == NULL; | |
432 | msymbol = msymbol->hash_next) | |
c906108c | 433 | { |
f56f77c1 | 434 | if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 && |
c906108c SS |
435 | MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) |
436 | return msymbol; | |
437 | } | |
438 | } | |
439 | } | |
440 | ||
441 | return NULL; | |
442 | } | |
443 | ||
c906108c SS |
444 | /* Search through the minimal symbol table for each objfile and find |
445 | the symbol whose address is the largest address that is still less | |
00878c6e PP |
446 | than or equal to PC, and matches SECTION (which is not NULL). |
447 | Returns a pointer to the minimal symbol if such a symbol is found, | |
448 | or NULL if PC is not in a suitable range. | |
449 | Note that we need to look through ALL the minimal symbol tables | |
450 | before deciding on the symbol that comes closest to the specified PC. | |
451 | This is because objfiles can overlap, for example objfile A has .text | |
452 | at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and | |
453 | .data at 0x40048. | |
c906108c | 454 | |
2eaf8d2a DJ |
455 | If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when |
456 | there are text and trampoline symbols at the same address. | |
457 | Otherwise prefer mst_text symbols. */ | |
458 | ||
459 | static struct minimal_symbol * | |
714835d5 UW |
460 | lookup_minimal_symbol_by_pc_section_1 (CORE_ADDR pc, |
461 | struct obj_section *section, | |
2eaf8d2a | 462 | int want_trampoline) |
c906108c SS |
463 | { |
464 | int lo; | |
465 | int hi; | |
466 | int new; | |
467 | struct objfile *objfile; | |
468 | struct minimal_symbol *msymbol; | |
469 | struct minimal_symbol *best_symbol = NULL; | |
2eaf8d2a | 470 | enum minimal_symbol_type want_type, other_type; |
c906108c | 471 | |
2eaf8d2a DJ |
472 | want_type = want_trampoline ? mst_solib_trampoline : mst_text; |
473 | other_type = want_trampoline ? mst_text : mst_solib_trampoline; | |
00878c6e PP |
474 | |
475 | /* We can not require the symbol found to be in section, because | |
96225718 DJ |
476 | e.g. IRIX 6.5 mdebug relies on this code returning an absolute |
477 | symbol - but find_pc_section won't return an absolute section and | |
478 | hence the code below would skip over absolute symbols. We can | |
479 | still take advantage of the call to find_pc_section, though - the | |
480 | object file still must match. In case we have separate debug | |
481 | files, search both the file and its separate debug file. There's | |
482 | no telling which one will have the minimal symbols. */ | |
483 | ||
00878c6e | 484 | gdb_assert (section != NULL); |
96225718 | 485 | |
15d123c9 TG |
486 | for (objfile = section->objfile; |
487 | objfile != NULL; | |
488 | objfile = objfile_separate_debug_iterate (section->objfile, objfile)) | |
c906108c SS |
489 | { |
490 | /* If this objfile has a minimal symbol table, go search it using | |
c5aa993b JM |
491 | a binary search. Note that a minimal symbol table always consists |
492 | of at least two symbols, a "real" symbol and the terminating | |
493 | "null symbol". If there are no real symbols, then there is no | |
025bb325 | 494 | minimal symbol table at all. */ |
c906108c | 495 | |
15831452 | 496 | if (objfile->minimal_symbol_count > 0) |
c906108c | 497 | { |
29e8a844 DJ |
498 | int best_zero_sized = -1; |
499 | ||
15831452 | 500 | msymbol = objfile->msymbols; |
c906108c | 501 | lo = 0; |
c5aa993b | 502 | hi = objfile->minimal_symbol_count - 1; |
c906108c SS |
503 | |
504 | /* This code assumes that the minimal symbols are sorted by | |
505 | ascending address values. If the pc value is greater than or | |
506 | equal to the first symbol's address, then some symbol in this | |
507 | minimal symbol table is a suitable candidate for being the | |
508 | "best" symbol. This includes the last real symbol, for cases | |
509 | where the pc value is larger than any address in this vector. | |
510 | ||
511 | By iterating until the address associated with the current | |
512 | hi index (the endpoint of the test interval) is less than | |
513 | or equal to the desired pc value, we accomplish two things: | |
514 | (1) the case where the pc value is larger than any minimal | |
515 | symbol address is trivially solved, (2) the address associated | |
516 | with the hi index is always the one we want when the interation | |
517 | terminates. In essence, we are iterating the test interval | |
518 | down until the pc value is pushed out of it from the high end. | |
519 | ||
025bb325 | 520 | Warning: this code is trickier than it would appear at first. */ |
c906108c | 521 | |
025bb325 | 522 | /* Should also require that pc is <= end of objfile. FIXME! */ |
c906108c SS |
523 | if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo])) |
524 | { | |
525 | while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc) | |
526 | { | |
025bb325 MS |
527 | /* pc is still strictly less than highest address. */ |
528 | /* Note "new" will always be >= lo. */ | |
c906108c SS |
529 | new = (lo + hi) / 2; |
530 | if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) || | |
531 | (lo == new)) | |
532 | { | |
533 | hi = new; | |
534 | } | |
535 | else | |
536 | { | |
537 | lo = new; | |
538 | } | |
539 | } | |
540 | ||
541 | /* If we have multiple symbols at the same address, we want | |
c5aa993b JM |
542 | hi to point to the last one. That way we can find the |
543 | right symbol if it has an index greater than hi. */ | |
544 | while (hi < objfile->minimal_symbol_count - 1 | |
c906108c | 545 | && (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) |
c5aa993b | 546 | == SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1]))) |
c906108c SS |
547 | hi++; |
548 | ||
29e8a844 DJ |
549 | /* Skip various undesirable symbols. */ |
550 | while (hi >= 0) | |
551 | { | |
552 | /* Skip any absolute symbols. This is apparently | |
553 | what adb and dbx do, and is needed for the CM-5. | |
554 | There are two known possible problems: (1) on | |
555 | ELF, apparently end, edata, etc. are absolute. | |
556 | Not sure ignoring them here is a big deal, but if | |
557 | we want to use them, the fix would go in | |
558 | elfread.c. (2) I think shared library entry | |
559 | points on the NeXT are absolute. If we want | |
560 | special handling for this it probably should be | |
561 | triggered by a special mst_abs_or_lib or some | |
562 | such. */ | |
563 | ||
712f90be | 564 | if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs) |
29e8a844 DJ |
565 | { |
566 | hi--; | |
567 | continue; | |
568 | } | |
569 | ||
570 | /* If SECTION was specified, skip any symbol from | |
571 | wrong section. */ | |
572 | if (section | |
573 | /* Some types of debug info, such as COFF, | |
574 | don't fill the bfd_section member, so don't | |
575 | throw away symbols on those platforms. */ | |
714835d5 UW |
576 | && SYMBOL_OBJ_SECTION (&msymbol[hi]) != NULL |
577 | && (!matching_obj_sections | |
578 | (SYMBOL_OBJ_SECTION (&msymbol[hi]), section))) | |
29e8a844 DJ |
579 | { |
580 | hi--; | |
581 | continue; | |
582 | } | |
583 | ||
2eaf8d2a DJ |
584 | /* If we are looking for a trampoline and this is a |
585 | text symbol, or the other way around, check the | |
177b42fe | 586 | preceding symbol too. If they are otherwise |
2eaf8d2a DJ |
587 | identical prefer that one. */ |
588 | if (hi > 0 | |
589 | && MSYMBOL_TYPE (&msymbol[hi]) == other_type | |
590 | && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type | |
591 | && (MSYMBOL_SIZE (&msymbol[hi]) | |
592 | == MSYMBOL_SIZE (&msymbol[hi - 1])) | |
593 | && (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) | |
594 | == SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1])) | |
714835d5 UW |
595 | && (SYMBOL_OBJ_SECTION (&msymbol[hi]) |
596 | == SYMBOL_OBJ_SECTION (&msymbol[hi - 1]))) | |
2eaf8d2a DJ |
597 | { |
598 | hi--; | |
599 | continue; | |
600 | } | |
601 | ||
29e8a844 DJ |
602 | /* If the minimal symbol has a zero size, save it |
603 | but keep scanning backwards looking for one with | |
604 | a non-zero size. A zero size may mean that the | |
605 | symbol isn't an object or function (e.g. a | |
606 | label), or it may just mean that the size was not | |
607 | specified. */ | |
608 | if (MSYMBOL_SIZE (&msymbol[hi]) == 0 | |
609 | && best_zero_sized == -1) | |
610 | { | |
611 | best_zero_sized = hi; | |
612 | hi--; | |
613 | continue; | |
614 | } | |
615 | ||
f7a6bb70 DJ |
616 | /* If we are past the end of the current symbol, try |
617 | the previous symbol if it has a larger overlapping | |
618 | size. This happens on i686-pc-linux-gnu with glibc; | |
619 | the nocancel variants of system calls are inside | |
620 | the cancellable variants, but both have sizes. */ | |
621 | if (hi > 0 | |
622 | && MSYMBOL_SIZE (&msymbol[hi]) != 0 | |
623 | && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) | |
624 | + MSYMBOL_SIZE (&msymbol[hi])) | |
625 | && pc < (SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1]) | |
626 | + MSYMBOL_SIZE (&msymbol[hi - 1]))) | |
627 | { | |
628 | hi--; | |
629 | continue; | |
630 | } | |
631 | ||
29e8a844 DJ |
632 | /* Otherwise, this symbol must be as good as we're going |
633 | to get. */ | |
634 | break; | |
635 | } | |
636 | ||
637 | /* If HI has a zero size, and best_zero_sized is set, | |
638 | then we had two or more zero-sized symbols; prefer | |
639 | the first one we found (which may have a higher | |
640 | address). Also, if we ran off the end, be sure | |
641 | to back up. */ | |
642 | if (best_zero_sized != -1 | |
643 | && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0)) | |
644 | hi = best_zero_sized; | |
645 | ||
646 | /* If the minimal symbol has a non-zero size, and this | |
647 | PC appears to be outside the symbol's contents, then | |
648 | refuse to use this symbol. If we found a zero-sized | |
649 | symbol with an address greater than this symbol's, | |
650 | use that instead. We assume that if symbols have | |
651 | specified sizes, they do not overlap. */ | |
652 | ||
653 | if (hi >= 0 | |
654 | && MSYMBOL_SIZE (&msymbol[hi]) != 0 | |
655 | && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) | |
656 | + MSYMBOL_SIZE (&msymbol[hi]))) | |
657 | { | |
658 | if (best_zero_sized != -1) | |
659 | hi = best_zero_sized; | |
660 | else | |
661 | /* Go on to the next object file. */ | |
662 | continue; | |
663 | } | |
664 | ||
c906108c | 665 | /* The minimal symbol indexed by hi now is the best one in this |
c5aa993b | 666 | objfile's minimal symbol table. See if it is the best one |
025bb325 | 667 | overall. */ |
c906108c | 668 | |
c906108c SS |
669 | if (hi >= 0 |
670 | && ((best_symbol == NULL) || | |
c5aa993b | 671 | (SYMBOL_VALUE_ADDRESS (best_symbol) < |
c906108c SS |
672 | SYMBOL_VALUE_ADDRESS (&msymbol[hi])))) |
673 | { | |
674 | best_symbol = &msymbol[hi]; | |
675 | } | |
676 | } | |
677 | } | |
678 | } | |
679 | return (best_symbol); | |
680 | } | |
681 | ||
2eaf8d2a | 682 | struct minimal_symbol * |
714835d5 | 683 | lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, struct obj_section *section) |
2eaf8d2a | 684 | { |
00878c6e PP |
685 | if (section == NULL) |
686 | { | |
687 | /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to | |
688 | force the section but that (well unless you're doing overlay | |
689 | debugging) always returns NULL making the call somewhat useless. */ | |
690 | section = find_pc_section (pc); | |
691 | if (section == NULL) | |
692 | return NULL; | |
693 | } | |
2eaf8d2a DJ |
694 | return lookup_minimal_symbol_by_pc_section_1 (pc, section, 0); |
695 | } | |
696 | ||
c906108c | 697 | /* Backward compatibility: search through the minimal symbol table |
025bb325 | 698 | for a matching PC (no section given). */ |
c906108c SS |
699 | |
700 | struct minimal_symbol * | |
fba45db2 | 701 | lookup_minimal_symbol_by_pc (CORE_ADDR pc) |
c906108c | 702 | { |
00878c6e | 703 | return lookup_minimal_symbol_by_pc_section (pc, NULL); |
c906108c | 704 | } |
0d5392b8 | 705 | |
0875794a JK |
706 | /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */ |
707 | ||
708 | int | |
709 | in_gnu_ifunc_stub (CORE_ADDR pc) | |
710 | { | |
711 | struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc); | |
712 | ||
713 | return msymbol && MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc; | |
714 | } | |
715 | ||
07be84bf JK |
716 | /* See elf_gnu_ifunc_resolve_addr for its real implementation. */ |
717 | ||
718 | static CORE_ADDR | |
719 | stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc) | |
720 | { | |
721 | error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without " | |
722 | "the ELF support compiled in."), | |
723 | paddress (gdbarch, pc)); | |
724 | } | |
725 | ||
726 | /* See elf_gnu_ifunc_resolve_name for its real implementation. */ | |
727 | ||
728 | static int | |
729 | stub_gnu_ifunc_resolve_name (const char *function_name, | |
730 | CORE_ADDR *function_address_p) | |
731 | { | |
732 | error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without " | |
733 | "the ELF support compiled in."), | |
734 | function_name); | |
735 | } | |
736 | ||
0e30163f JK |
737 | /* See elf_gnu_ifunc_resolver_stop for its real implementation. */ |
738 | ||
739 | static void | |
740 | stub_gnu_ifunc_resolver_stop (struct breakpoint *b) | |
741 | { | |
742 | internal_error (__FILE__, __LINE__, | |
743 | _("elf_gnu_ifunc_resolver_stop cannot be reached.")); | |
744 | } | |
745 | ||
746 | /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */ | |
747 | ||
748 | static void | |
749 | stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b) | |
750 | { | |
751 | internal_error (__FILE__, __LINE__, | |
752 | _("elf_gnu_ifunc_resolver_return_stop cannot be reached.")); | |
753 | } | |
754 | ||
07be84bf JK |
755 | /* See elf_gnu_ifunc_fns for its real implementation. */ |
756 | ||
757 | static const struct gnu_ifunc_fns stub_gnu_ifunc_fns = | |
758 | { | |
759 | stub_gnu_ifunc_resolve_addr, | |
760 | stub_gnu_ifunc_resolve_name, | |
0e30163f JK |
761 | stub_gnu_ifunc_resolver_stop, |
762 | stub_gnu_ifunc_resolver_return_stop, | |
07be84bf JK |
763 | }; |
764 | ||
765 | /* A placeholder for &elf_gnu_ifunc_fns. */ | |
766 | ||
767 | const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns; | |
768 | ||
0d5392b8 TT |
769 | /* Find the minimal symbol named NAME, and return both the minsym |
770 | struct and its objfile. This only checks the linkage name. Sets | |
771 | *OBJFILE_P and returns the minimal symbol, if it is found. If it | |
772 | is not found, returns NULL. */ | |
773 | ||
774 | struct minimal_symbol * | |
775 | lookup_minimal_symbol_and_objfile (const char *name, | |
776 | struct objfile **objfile_p) | |
777 | { | |
778 | struct objfile *objfile; | |
779 | unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; | |
780 | ||
781 | ALL_OBJFILES (objfile) | |
782 | { | |
783 | struct minimal_symbol *msym; | |
784 | ||
785 | for (msym = objfile->msymbol_hash[hash]; | |
786 | msym != NULL; | |
787 | msym = msym->hash_next) | |
788 | { | |
789 | if (strcmp (SYMBOL_LINKAGE_NAME (msym), name) == 0) | |
790 | { | |
791 | *objfile_p = objfile; | |
792 | return msym; | |
793 | } | |
794 | } | |
795 | } | |
796 | ||
797 | return 0; | |
798 | } | |
c906108c | 799 | \f |
c5aa993b | 800 | |
025bb325 | 801 | /* Return leading symbol character for a BFD. If BFD is NULL, |
c906108c SS |
802 | return the leading symbol character from the main objfile. */ |
803 | ||
a14ed312 | 804 | static int get_symbol_leading_char (bfd *); |
c906108c SS |
805 | |
806 | static int | |
fba45db2 | 807 | get_symbol_leading_char (bfd *abfd) |
c906108c SS |
808 | { |
809 | if (abfd != NULL) | |
810 | return bfd_get_symbol_leading_char (abfd); | |
811 | if (symfile_objfile != NULL && symfile_objfile->obfd != NULL) | |
812 | return bfd_get_symbol_leading_char (symfile_objfile->obfd); | |
813 | return 0; | |
814 | } | |
815 | ||
816 | /* Prepare to start collecting minimal symbols. Note that presetting | |
817 | msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal | |
025bb325 | 818 | symbol to allocate the memory for the first bunch. */ |
c906108c SS |
819 | |
820 | void | |
fba45db2 | 821 | init_minimal_symbol_collection (void) |
c906108c SS |
822 | { |
823 | msym_count = 0; | |
824 | msym_bunch = NULL; | |
825 | msym_bunch_index = BUNCH_SIZE; | |
826 | } | |
827 | ||
828 | void | |
fba45db2 KB |
829 | prim_record_minimal_symbol (const char *name, CORE_ADDR address, |
830 | enum minimal_symbol_type ms_type, | |
831 | struct objfile *objfile) | |
c906108c SS |
832 | { |
833 | int section; | |
834 | ||
835 | switch (ms_type) | |
836 | { | |
837 | case mst_text: | |
0875794a | 838 | case mst_text_gnu_ifunc: |
c906108c SS |
839 | case mst_file_text: |
840 | case mst_solib_trampoline: | |
b8fbeb18 | 841 | section = SECT_OFF_TEXT (objfile); |
c906108c SS |
842 | break; |
843 | case mst_data: | |
844 | case mst_file_data: | |
b8fbeb18 | 845 | section = SECT_OFF_DATA (objfile); |
c906108c SS |
846 | break; |
847 | case mst_bss: | |
848 | case mst_file_bss: | |
b8fbeb18 | 849 | section = SECT_OFF_BSS (objfile); |
c906108c SS |
850 | break; |
851 | default: | |
852 | section = -1; | |
853 | } | |
854 | ||
855 | prim_record_minimal_symbol_and_info (name, address, ms_type, | |
b887350f | 856 | section, NULL, objfile); |
c906108c SS |
857 | } |
858 | ||
859 | /* Record a minimal symbol in the msym bunches. Returns the symbol | |
860 | newly created. */ | |
861 | ||
862 | struct minimal_symbol * | |
04a679b8 TT |
863 | prim_record_minimal_symbol_full (const char *name, int name_len, int copy_name, |
864 | CORE_ADDR address, | |
865 | enum minimal_symbol_type ms_type, | |
866 | int section, | |
867 | asection *bfd_section, | |
868 | struct objfile *objfile) | |
c906108c | 869 | { |
714835d5 | 870 | struct obj_section *obj_section; |
52f0bd74 AC |
871 | struct msym_bunch *new; |
872 | struct minimal_symbol *msymbol; | |
c906108c | 873 | |
66337bb1 CV |
874 | /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into |
875 | the minimal symbols, because if there is also another symbol | |
876 | at the same address (e.g. the first function of the file), | |
877 | lookup_minimal_symbol_by_pc would have no way of getting the | |
878 | right one. */ | |
879 | if (ms_type == mst_file_text && name[0] == 'g' | |
880 | && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0 | |
881 | || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0)) | |
882 | return (NULL); | |
883 | ||
884 | /* It's safe to strip the leading char here once, since the name | |
025bb325 | 885 | is also stored stripped in the minimal symbol table. */ |
66337bb1 | 886 | if (name[0] == get_symbol_leading_char (objfile->obfd)) |
04a679b8 TT |
887 | { |
888 | ++name; | |
889 | --name_len; | |
890 | } | |
66337bb1 CV |
891 | |
892 | if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0) | |
893 | return (NULL); | |
c906108c SS |
894 | |
895 | if (msym_bunch_index == BUNCH_SIZE) | |
896 | { | |
edb3359d | 897 | new = XCALLOC (1, struct msym_bunch); |
c906108c | 898 | msym_bunch_index = 0; |
c5aa993b | 899 | new->next = msym_bunch; |
c906108c SS |
900 | msym_bunch = new; |
901 | } | |
c5aa993b | 902 | msymbol = &msym_bunch->contents[msym_bunch_index]; |
33e5013e | 903 | SYMBOL_SET_LANGUAGE (msymbol, language_auto); |
04a679b8 | 904 | SYMBOL_SET_NAMES (msymbol, name, name_len, copy_name, objfile); |
2de7ced7 | 905 | |
c906108c SS |
906 | SYMBOL_VALUE_ADDRESS (msymbol) = address; |
907 | SYMBOL_SECTION (msymbol) = section; | |
714835d5 UW |
908 | SYMBOL_OBJ_SECTION (msymbol) = NULL; |
909 | ||
910 | /* Find obj_section corresponding to bfd_section. */ | |
911 | if (bfd_section) | |
912 | ALL_OBJFILE_OSECTIONS (objfile, obj_section) | |
913 | { | |
914 | if (obj_section->the_bfd_section == bfd_section) | |
915 | { | |
916 | SYMBOL_OBJ_SECTION (msymbol) = obj_section; | |
917 | break; | |
918 | } | |
919 | } | |
c906108c SS |
920 | |
921 | MSYMBOL_TYPE (msymbol) = ms_type; | |
b887350f TT |
922 | MSYMBOL_TARGET_FLAG_1 (msymbol) = 0; |
923 | MSYMBOL_TARGET_FLAG_2 (msymbol) = 0; | |
f594e5e9 | 924 | MSYMBOL_SIZE (msymbol) = 0; |
9227b5eb | 925 | |
a79dea61 | 926 | /* The hash pointers must be cleared! If they're not, |
025bb325 | 927 | add_minsym_to_hash_table will NOT add this msymbol to the hash table. */ |
9227b5eb JB |
928 | msymbol->hash_next = NULL; |
929 | msymbol->demangled_hash_next = NULL; | |
930 | ||
c906108c SS |
931 | msym_bunch_index++; |
932 | msym_count++; | |
933 | OBJSTAT (objfile, n_minsyms++); | |
934 | return msymbol; | |
935 | } | |
936 | ||
04a679b8 TT |
937 | /* Record a minimal symbol in the msym bunches. Returns the symbol |
938 | newly created. */ | |
939 | ||
940 | struct minimal_symbol * | |
941 | prim_record_minimal_symbol_and_info (const char *name, CORE_ADDR address, | |
942 | enum minimal_symbol_type ms_type, | |
943 | int section, | |
944 | asection *bfd_section, | |
945 | struct objfile *objfile) | |
946 | { | |
947 | return prim_record_minimal_symbol_full (name, strlen (name), 1, | |
948 | address, ms_type, section, | |
949 | bfd_section, objfile); | |
950 | } | |
951 | ||
c906108c | 952 | /* Compare two minimal symbols by address and return a signed result based |
025bb325 | 953 | on unsigned comparisons, so that we sort into unsigned numeric order. |
c906108c SS |
954 | Within groups with the same address, sort by name. */ |
955 | ||
956 | static int | |
12b9c64f | 957 | compare_minimal_symbols (const void *fn1p, const void *fn2p) |
c906108c | 958 | { |
52f0bd74 AC |
959 | const struct minimal_symbol *fn1; |
960 | const struct minimal_symbol *fn2; | |
c906108c SS |
961 | |
962 | fn1 = (const struct minimal_symbol *) fn1p; | |
963 | fn2 = (const struct minimal_symbol *) fn2p; | |
964 | ||
965 | if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2)) | |
966 | { | |
025bb325 | 967 | return (-1); /* addr 1 is less than addr 2. */ |
c906108c SS |
968 | } |
969 | else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2)) | |
970 | { | |
025bb325 | 971 | return (1); /* addr 1 is greater than addr 2. */ |
c906108c | 972 | } |
c5aa993b JM |
973 | else |
974 | /* addrs are equal: sort by name */ | |
c906108c | 975 | { |
f56f77c1 DC |
976 | char *name1 = SYMBOL_LINKAGE_NAME (fn1); |
977 | char *name2 = SYMBOL_LINKAGE_NAME (fn2); | |
c906108c SS |
978 | |
979 | if (name1 && name2) /* both have names */ | |
980 | return strcmp (name1, name2); | |
981 | else if (name2) | |
025bb325 MS |
982 | return 1; /* fn1 has no name, so it is "less". */ |
983 | else if (name1) /* fn2 has no name, so it is "less". */ | |
c906108c SS |
984 | return -1; |
985 | else | |
025bb325 | 986 | return (0); /* Neither has a name, so they're equal. */ |
c906108c SS |
987 | } |
988 | } | |
989 | ||
990 | /* Discard the currently collected minimal symbols, if any. If we wish | |
991 | to save them for later use, we must have already copied them somewhere | |
992 | else before calling this function. | |
993 | ||
994 | FIXME: We could allocate the minimal symbol bunches on their own | |
995 | obstack and then simply blow the obstack away when we are done with | |
025bb325 | 996 | it. Is it worth the extra trouble though? */ |
c906108c | 997 | |
56e290f4 AC |
998 | static void |
999 | do_discard_minimal_symbols_cleanup (void *arg) | |
c906108c | 1000 | { |
52f0bd74 | 1001 | struct msym_bunch *next; |
c906108c SS |
1002 | |
1003 | while (msym_bunch != NULL) | |
1004 | { | |
c5aa993b | 1005 | next = msym_bunch->next; |
b8c9b27d | 1006 | xfree (msym_bunch); |
c906108c SS |
1007 | msym_bunch = next; |
1008 | } | |
1009 | } | |
1010 | ||
56e290f4 AC |
1011 | struct cleanup * |
1012 | make_cleanup_discard_minimal_symbols (void) | |
1013 | { | |
1014 | return make_cleanup (do_discard_minimal_symbols_cleanup, 0); | |
1015 | } | |
1016 | ||
1017 | ||
9227b5eb | 1018 | |
c906108c SS |
1019 | /* Compact duplicate entries out of a minimal symbol table by walking |
1020 | through the table and compacting out entries with duplicate addresses | |
1021 | and matching names. Return the number of entries remaining. | |
1022 | ||
1023 | On entry, the table resides between msymbol[0] and msymbol[mcount]. | |
1024 | On exit, it resides between msymbol[0] and msymbol[result_count]. | |
1025 | ||
1026 | When files contain multiple sources of symbol information, it is | |
1027 | possible for the minimal symbol table to contain many duplicate entries. | |
1028 | As an example, SVR4 systems use ELF formatted object files, which | |
1029 | usually contain at least two different types of symbol tables (a | |
1030 | standard ELF one and a smaller dynamic linking table), as well as | |
1031 | DWARF debugging information for files compiled with -g. | |
1032 | ||
1033 | Without compacting, the minimal symbol table for gdb itself contains | |
1034 | over a 1000 duplicates, about a third of the total table size. Aside | |
1035 | from the potential trap of not noticing that two successive entries | |
1036 | identify the same location, this duplication impacts the time required | |
1037 | to linearly scan the table, which is done in a number of places. So we | |
1038 | just do one linear scan here and toss out the duplicates. | |
1039 | ||
1040 | Note that we are not concerned here about recovering the space that | |
1041 | is potentially freed up, because the strings themselves are allocated | |
4a146b47 | 1042 | on the objfile_obstack, and will get automatically freed when the symbol |
c906108c SS |
1043 | table is freed. The caller can free up the unused minimal symbols at |
1044 | the end of the compacted region if their allocation strategy allows it. | |
1045 | ||
1046 | Also note we only go up to the next to last entry within the loop | |
1047 | and then copy the last entry explicitly after the loop terminates. | |
1048 | ||
1049 | Since the different sources of information for each symbol may | |
1050 | have different levels of "completeness", we may have duplicates | |
1051 | that have one entry with type "mst_unknown" and the other with a | |
1052 | known type. So if the one we are leaving alone has type mst_unknown, | |
1053 | overwrite its type with the type from the one we are compacting out. */ | |
1054 | ||
1055 | static int | |
fba45db2 KB |
1056 | compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount, |
1057 | struct objfile *objfile) | |
c906108c SS |
1058 | { |
1059 | struct minimal_symbol *copyfrom; | |
1060 | struct minimal_symbol *copyto; | |
1061 | ||
1062 | if (mcount > 0) | |
1063 | { | |
1064 | copyfrom = copyto = msymbol; | |
1065 | while (copyfrom < msymbol + mcount - 1) | |
1066 | { | |
6314a349 AC |
1067 | if (SYMBOL_VALUE_ADDRESS (copyfrom) |
1068 | == SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) | |
1069 | && strcmp (SYMBOL_LINKAGE_NAME (copyfrom), | |
1070 | SYMBOL_LINKAGE_NAME ((copyfrom + 1))) == 0) | |
c906108c | 1071 | { |
c5aa993b | 1072 | if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown) |
c906108c SS |
1073 | { |
1074 | MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom); | |
1075 | } | |
1076 | copyfrom++; | |
1077 | } | |
1078 | else | |
afbb8d7a | 1079 | *copyto++ = *copyfrom++; |
c906108c SS |
1080 | } |
1081 | *copyto++ = *copyfrom++; | |
1082 | mcount = copyto - msymbol; | |
1083 | } | |
1084 | return (mcount); | |
1085 | } | |
1086 | ||
afbb8d7a KB |
1087 | /* Build (or rebuild) the minimal symbol hash tables. This is necessary |
1088 | after compacting or sorting the table since the entries move around | |
025bb325 | 1089 | thus causing the internal minimal_symbol pointers to become jumbled. */ |
afbb8d7a KB |
1090 | |
1091 | static void | |
1092 | build_minimal_symbol_hash_tables (struct objfile *objfile) | |
1093 | { | |
1094 | int i; | |
1095 | struct minimal_symbol *msym; | |
1096 | ||
025bb325 | 1097 | /* Clear the hash tables. */ |
afbb8d7a KB |
1098 | for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++) |
1099 | { | |
1100 | objfile->msymbol_hash[i] = 0; | |
1101 | objfile->msymbol_demangled_hash[i] = 0; | |
1102 | } | |
1103 | ||
025bb325 | 1104 | /* Now, (re)insert the actual entries. */ |
afbb8d7a KB |
1105 | for (i = objfile->minimal_symbol_count, msym = objfile->msymbols; |
1106 | i > 0; | |
1107 | i--, msym++) | |
1108 | { | |
1109 | msym->hash_next = 0; | |
1110 | add_minsym_to_hash_table (msym, objfile->msymbol_hash); | |
1111 | ||
1112 | msym->demangled_hash_next = 0; | |
4725b721 | 1113 | if (SYMBOL_SEARCH_NAME (msym) != SYMBOL_LINKAGE_NAME (msym)) |
afbb8d7a KB |
1114 | add_minsym_to_demangled_hash_table (msym, |
1115 | objfile->msymbol_demangled_hash); | |
1116 | } | |
1117 | } | |
1118 | ||
c906108c SS |
1119 | /* Add the minimal symbols in the existing bunches to the objfile's official |
1120 | minimal symbol table. In most cases there is no minimal symbol table yet | |
1121 | for this objfile, and the existing bunches are used to create one. Once | |
1122 | in a while (for shared libraries for example), we add symbols (e.g. common | |
1123 | symbols) to an existing objfile. | |
1124 | ||
1125 | Because of the way minimal symbols are collected, we generally have no way | |
1126 | of knowing what source language applies to any particular minimal symbol. | |
1127 | Specifically, we have no way of knowing if the minimal symbol comes from a | |
1128 | C++ compilation unit or not. So for the sake of supporting cached | |
1129 | demangled C++ names, we have no choice but to try and demangle each new one | |
1130 | that comes in. If the demangling succeeds, then we assume it is a C++ | |
1131 | symbol and set the symbol's language and demangled name fields | |
1132 | appropriately. Note that in order to avoid unnecessary demanglings, and | |
1133 | allocating obstack space that subsequently can't be freed for the demangled | |
1134 | names, we mark all newly added symbols with language_auto. After | |
1135 | compaction of the minimal symbols, we go back and scan the entire minimal | |
1136 | symbol table looking for these new symbols. For each new symbol we attempt | |
1137 | to demangle it, and if successful, record it as a language_cplus symbol | |
1138 | and cache the demangled form on the symbol obstack. Symbols which don't | |
1139 | demangle are marked as language_unknown symbols, which inhibits future | |
025bb325 | 1140 | attempts to demangle them if we later add more minimal symbols. */ |
c906108c SS |
1141 | |
1142 | void | |
fba45db2 | 1143 | install_minimal_symbols (struct objfile *objfile) |
c906108c | 1144 | { |
52f0bd74 AC |
1145 | int bindex; |
1146 | int mcount; | |
1147 | struct msym_bunch *bunch; | |
1148 | struct minimal_symbol *msymbols; | |
c906108c | 1149 | int alloc_count; |
c906108c SS |
1150 | |
1151 | if (msym_count > 0) | |
1152 | { | |
1153 | /* Allocate enough space in the obstack, into which we will gather the | |
c5aa993b JM |
1154 | bunches of new and existing minimal symbols, sort them, and then |
1155 | compact out the duplicate entries. Once we have a final table, | |
1156 | we will give back the excess space. */ | |
c906108c SS |
1157 | |
1158 | alloc_count = msym_count + objfile->minimal_symbol_count + 1; | |
4a146b47 | 1159 | obstack_blank (&objfile->objfile_obstack, |
c906108c SS |
1160 | alloc_count * sizeof (struct minimal_symbol)); |
1161 | msymbols = (struct minimal_symbol *) | |
4a146b47 | 1162 | obstack_base (&objfile->objfile_obstack); |
c906108c SS |
1163 | |
1164 | /* Copy in the existing minimal symbols, if there are any. */ | |
1165 | ||
1166 | if (objfile->minimal_symbol_count) | |
c5aa993b JM |
1167 | memcpy ((char *) msymbols, (char *) objfile->msymbols, |
1168 | objfile->minimal_symbol_count * sizeof (struct minimal_symbol)); | |
c906108c SS |
1169 | |
1170 | /* Walk through the list of minimal symbol bunches, adding each symbol | |
c5aa993b JM |
1171 | to the new contiguous array of symbols. Note that we start with the |
1172 | current, possibly partially filled bunch (thus we use the current | |
1173 | msym_bunch_index for the first bunch we copy over), and thereafter | |
025bb325 | 1174 | each bunch is full. */ |
c5aa993b | 1175 | |
c906108c | 1176 | mcount = objfile->minimal_symbol_count; |
c5aa993b JM |
1177 | |
1178 | for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next) | |
c906108c SS |
1179 | { |
1180 | for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++) | |
66337bb1 | 1181 | msymbols[mcount] = bunch->contents[bindex]; |
c906108c SS |
1182 | msym_bunch_index = BUNCH_SIZE; |
1183 | } | |
1184 | ||
1185 | /* Sort the minimal symbols by address. */ | |
c5aa993b | 1186 | |
c906108c SS |
1187 | qsort (msymbols, mcount, sizeof (struct minimal_symbol), |
1188 | compare_minimal_symbols); | |
c5aa993b | 1189 | |
c906108c | 1190 | /* Compact out any duplicates, and free up whatever space we are |
c5aa993b JM |
1191 | no longer using. */ |
1192 | ||
9227b5eb | 1193 | mcount = compact_minimal_symbols (msymbols, mcount, objfile); |
c906108c | 1194 | |
4a146b47 | 1195 | obstack_blank (&objfile->objfile_obstack, |
c5aa993b | 1196 | (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol)); |
c906108c | 1197 | msymbols = (struct minimal_symbol *) |
4a146b47 | 1198 | obstack_finish (&objfile->objfile_obstack); |
c906108c SS |
1199 | |
1200 | /* We also terminate the minimal symbol table with a "null symbol", | |
c5aa993b JM |
1201 | which is *not* included in the size of the table. This makes it |
1202 | easier to find the end of the table when we are handed a pointer | |
1203 | to some symbol in the middle of it. Zero out the fields in the | |
1204 | "null symbol" allocated at the end of the array. Note that the | |
1205 | symbol count does *not* include this null symbol, which is why it | |
025bb325 | 1206 | is indexed by mcount and not mcount-1. */ |
c906108c | 1207 | |
f56f77c1 | 1208 | SYMBOL_LINKAGE_NAME (&msymbols[mcount]) = NULL; |
c906108c | 1209 | SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0; |
b887350f TT |
1210 | MSYMBOL_TARGET_FLAG_1 (&msymbols[mcount]) = 0; |
1211 | MSYMBOL_TARGET_FLAG_2 (&msymbols[mcount]) = 0; | |
f594e5e9 | 1212 | MSYMBOL_SIZE (&msymbols[mcount]) = 0; |
c906108c | 1213 | MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown; |
33e5013e | 1214 | SYMBOL_SET_LANGUAGE (&msymbols[mcount], language_unknown); |
c906108c SS |
1215 | |
1216 | /* Attach the minimal symbol table to the specified objfile. | |
4a146b47 | 1217 | The strings themselves are also located in the objfile_obstack |
c5aa993b | 1218 | of this objfile. */ |
c906108c | 1219 | |
c5aa993b JM |
1220 | objfile->minimal_symbol_count = mcount; |
1221 | objfile->msymbols = msymbols; | |
c906108c | 1222 | |
7ed49443 JB |
1223 | /* Try to guess the appropriate C++ ABI by looking at the names |
1224 | of the minimal symbols in the table. */ | |
1225 | { | |
1226 | int i; | |
1227 | ||
1228 | for (i = 0; i < mcount; i++) | |
1229 | { | |
6aca59a3 DJ |
1230 | /* If a symbol's name starts with _Z and was successfully |
1231 | demangled, then we can assume we've found a GNU v3 symbol. | |
1232 | For now we set the C++ ABI globally; if the user is | |
1233 | mixing ABIs then the user will need to "set cp-abi" | |
1234 | manually. */ | |
f56f77c1 | 1235 | const char *name = SYMBOL_LINKAGE_NAME (&objfile->msymbols[i]); |
b8d56208 | 1236 | |
6aca59a3 DJ |
1237 | if (name[0] == '_' && name[1] == 'Z' |
1238 | && SYMBOL_DEMANGLED_NAME (&objfile->msymbols[i]) != NULL) | |
7ed49443 | 1239 | { |
fe1f4a5e | 1240 | set_cp_abi_as_auto_default ("gnu-v3"); |
7ed49443 JB |
1241 | break; |
1242 | } | |
1243 | } | |
1244 | } | |
afbb8d7a KB |
1245 | |
1246 | /* Now build the hash tables; we can't do this incrementally | |
1247 | at an earlier point since we weren't finished with the obstack | |
1248 | yet. (And if the msymbol obstack gets moved, all the internal | |
025bb325 | 1249 | pointers to other msymbols need to be adjusted.) */ |
afbb8d7a | 1250 | build_minimal_symbol_hash_tables (objfile); |
c906108c SS |
1251 | } |
1252 | } | |
1253 | ||
1254 | /* Sort all the minimal symbols in OBJFILE. */ | |
1255 | ||
1256 | void | |
fba45db2 | 1257 | msymbols_sort (struct objfile *objfile) |
c906108c SS |
1258 | { |
1259 | qsort (objfile->msymbols, objfile->minimal_symbol_count, | |
1260 | sizeof (struct minimal_symbol), compare_minimal_symbols); | |
afbb8d7a | 1261 | build_minimal_symbol_hash_tables (objfile); |
c906108c SS |
1262 | } |
1263 | ||
1264 | /* Check if PC is in a shared library trampoline code stub. | |
1265 | Return minimal symbol for the trampoline entry or NULL if PC is not | |
1266 | in a trampoline code stub. */ | |
1267 | ||
1268 | struct minimal_symbol * | |
fba45db2 | 1269 | lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc) |
c906108c | 1270 | { |
2eaf8d2a DJ |
1271 | struct obj_section *section = find_pc_section (pc); |
1272 | struct minimal_symbol *msymbol; | |
1273 | ||
1274 | if (section == NULL) | |
1275 | return NULL; | |
714835d5 | 1276 | msymbol = lookup_minimal_symbol_by_pc_section_1 (pc, section, 1); |
c906108c SS |
1277 | |
1278 | if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) | |
1279 | return msymbol; | |
1280 | return NULL; | |
1281 | } | |
1282 | ||
1283 | /* If PC is in a shared library trampoline code stub, return the | |
1284 | address of the `real' function belonging to the stub. | |
1285 | Return 0 if PC is not in a trampoline code stub or if the real | |
1286 | function is not found in the minimal symbol table. | |
1287 | ||
1288 | We may fail to find the right function if a function with the | |
1289 | same name is defined in more than one shared library, but this | |
025bb325 | 1290 | is considered bad programming style. We could return 0 if we find |
c906108c SS |
1291 | a duplicate function in case this matters someday. */ |
1292 | ||
1293 | CORE_ADDR | |
52f729a7 | 1294 | find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc) |
c906108c SS |
1295 | { |
1296 | struct objfile *objfile; | |
1297 | struct minimal_symbol *msymbol; | |
1298 | struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc); | |
1299 | ||
1300 | if (tsymbol != NULL) | |
1301 | { | |
1302 | ALL_MSYMBOLS (objfile, msymbol) | |
c5aa993b | 1303 | { |
0875794a JK |
1304 | if ((MSYMBOL_TYPE (msymbol) == mst_text |
1305 | || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc) | |
6314a349 AC |
1306 | && strcmp (SYMBOL_LINKAGE_NAME (msymbol), |
1307 | SYMBOL_LINKAGE_NAME (tsymbol)) == 0) | |
c5aa993b | 1308 | return SYMBOL_VALUE_ADDRESS (msymbol); |
42848c96 UW |
1309 | |
1310 | /* Also handle minimal symbols pointing to function descriptors. */ | |
1311 | if (MSYMBOL_TYPE (msymbol) == mst_data | |
1312 | && strcmp (SYMBOL_LINKAGE_NAME (msymbol), | |
1313 | SYMBOL_LINKAGE_NAME (tsymbol)) == 0) | |
1314 | { | |
1315 | CORE_ADDR func; | |
b8d56208 | 1316 | |
42848c96 UW |
1317 | func = gdbarch_convert_from_func_ptr_addr |
1318 | (get_objfile_arch (objfile), | |
1319 | SYMBOL_VALUE_ADDRESS (msymbol), | |
1320 | ¤t_target); | |
1321 | ||
1322 | /* Ignore data symbols that are not function descriptors. */ | |
1323 | if (func != SYMBOL_VALUE_ADDRESS (msymbol)) | |
1324 | return func; | |
1325 | } | |
c5aa993b | 1326 | } |
c906108c SS |
1327 | } |
1328 | return 0; | |
1329 | } |