Commit | Line | Data |
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c906108c | 1 | /* Read ELF (Executable and Linking Format) object files for GDB. |
b6ba6518 | 2 | Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, |
181c1381 | 3 | 2001, 2002 |
8e65ff28 | 4 | Free Software Foundation, Inc. |
c906108c SS |
5 | Written by Fred Fish at Cygnus Support. |
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 | |
11 | the Free Software Foundation; either version 2 of the License, or | |
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 JM |
19 | You should have received a copy of the GNU General Public License |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
23 | |
24 | #include "defs.h" | |
25 | #include "bfd.h" | |
26 | #include "gdb_string.h" | |
27 | #include "elf-bfd.h" | |
28 | #include "elf/mips.h" | |
29 | #include "symtab.h" | |
30 | #include "symfile.h" | |
31 | #include "objfiles.h" | |
32 | #include "buildsym.h" | |
33 | #include "stabsread.h" | |
34 | #include "gdb-stabs.h" | |
35 | #include "complaints.h" | |
36 | #include "demangle.h" | |
37 | ||
a14ed312 | 38 | extern void _initialize_elfread (void); |
392a587b | 39 | |
c906108c | 40 | /* The struct elfinfo is available only during ELF symbol table and |
6426a772 | 41 | psymtab reading. It is destroyed at the completion of psymtab-reading. |
c906108c SS |
42 | It's local to elf_symfile_read. */ |
43 | ||
c5aa993b JM |
44 | struct elfinfo |
45 | { | |
46 | file_ptr dboffset; /* Offset to dwarf debug section */ | |
47 | unsigned int dbsize; /* Size of dwarf debug section */ | |
48 | file_ptr lnoffset; /* Offset to dwarf line number section */ | |
49 | unsigned int lnsize; /* Size of dwarf line number section */ | |
50 | asection *stabsect; /* Section pointer for .stab section */ | |
51 | asection *stabindexsect; /* Section pointer for .stab.index section */ | |
52 | asection *mdebugsect; /* Section pointer for .mdebug section */ | |
53 | }; | |
c906108c SS |
54 | |
55 | /* Various things we might complain about... */ | |
56 | ||
c5aa993b JM |
57 | struct complaint section_info_complaint = |
58 | {"elf/stab section information %s without a preceding file symbol", 0, 0}; | |
c906108c | 59 | |
c5aa993b JM |
60 | struct complaint section_info_dup_complaint = |
61 | {"duplicated elf/stab section information for %s", 0, 0}; | |
c906108c | 62 | |
c5aa993b JM |
63 | struct complaint stab_info_mismatch_complaint = |
64 | {"elf/stab section information missing for %s", 0, 0}; | |
c906108c | 65 | |
c5aa993b JM |
66 | struct complaint stab_info_questionable_complaint = |
67 | {"elf/stab section information questionable for %s", 0, 0}; | |
c906108c | 68 | |
12b9c64f | 69 | static void free_elfinfo (void *); |
c906108c SS |
70 | |
71 | /* We are called once per section from elf_symfile_read. We | |
72 | need to examine each section we are passed, check to see | |
73 | if it is something we are interested in processing, and | |
74 | if so, stash away some access information for the section. | |
75 | ||
76 | For now we recognize the dwarf debug information sections and | |
77 | line number sections from matching their section names. The | |
78 | ELF definition is no real help here since it has no direct | |
79 | knowledge of DWARF (by design, so any debugging format can be | |
80 | used). | |
81 | ||
82 | We also recognize the ".stab" sections used by the Sun compilers | |
83 | released with Solaris 2. | |
84 | ||
85 | FIXME: The section names should not be hardwired strings (what | |
86 | should they be? I don't think most object file formats have enough | |
87 | section flags to specify what kind of debug section it is | |
88 | -kingdon). */ | |
89 | ||
90 | static void | |
12b9c64f | 91 | elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip) |
c906108c SS |
92 | { |
93 | register struct elfinfo *ei; | |
94 | ||
95 | ei = (struct elfinfo *) eip; | |
c5aa993b | 96 | if (STREQ (sectp->name, ".debug")) |
c906108c | 97 | { |
c5aa993b JM |
98 | ei->dboffset = sectp->filepos; |
99 | ei->dbsize = bfd_get_section_size_before_reloc (sectp); | |
c906108c | 100 | } |
c5aa993b | 101 | else if (STREQ (sectp->name, ".line")) |
c906108c | 102 | { |
c5aa993b JM |
103 | ei->lnoffset = sectp->filepos; |
104 | ei->lnsize = bfd_get_section_size_before_reloc (sectp); | |
c906108c | 105 | } |
c5aa993b | 106 | else if (STREQ (sectp->name, ".stab")) |
c906108c | 107 | { |
c5aa993b | 108 | ei->stabsect = sectp; |
c906108c | 109 | } |
c5aa993b | 110 | else if (STREQ (sectp->name, ".stab.index")) |
c906108c | 111 | { |
c5aa993b | 112 | ei->stabindexsect = sectp; |
c906108c | 113 | } |
c5aa993b | 114 | else if (STREQ (sectp->name, ".mdebug")) |
c906108c | 115 | { |
c5aa993b | 116 | ei->mdebugsect = sectp; |
c906108c SS |
117 | } |
118 | } | |
119 | ||
c5aa993b | 120 | #if 0 /* Currently unused */ |
c906108c SS |
121 | |
122 | char * | |
fba45db2 | 123 | elf_interpreter (bfd *abfd) |
c906108c SS |
124 | { |
125 | sec_ptr interp_sec; | |
126 | unsigned size; | |
127 | char *interp = NULL; | |
128 | ||
129 | interp_sec = bfd_get_section_by_name (abfd, ".interp"); | |
130 | if (interp_sec) | |
131 | { | |
132 | size = bfd_section_size (abfd, interp_sec); | |
133 | interp = alloca (size); | |
c5aa993b | 134 | if (bfd_get_section_contents (abfd, interp_sec, interp, (file_ptr) 0, |
c906108c SS |
135 | size)) |
136 | { | |
137 | interp = savestring (interp, size - 1); | |
138 | } | |
139 | else | |
140 | { | |
141 | interp = NULL; | |
142 | } | |
143 | } | |
144 | return (interp); | |
145 | } | |
146 | ||
147 | #endif | |
148 | ||
149 | static struct minimal_symbol * | |
fba45db2 KB |
150 | record_minimal_symbol_and_info (char *name, CORE_ADDR address, |
151 | enum minimal_symbol_type ms_type, char *info, /* FIXME, is this really char *? */ | |
152 | asection *bfd_section, struct objfile *objfile) | |
c906108c | 153 | { |
bbeae047 | 154 | if (ms_type == mst_text || ms_type == mst_file_text) |
181c1381 | 155 | address = SMASH_TEXT_ADDRESS (address); |
c906108c SS |
156 | |
157 | return prim_record_minimal_symbol_and_info | |
bbeae047 | 158 | (name, address, ms_type, info, bfd_section->index, bfd_section, objfile); |
c906108c SS |
159 | } |
160 | ||
161 | /* | |
162 | ||
c5aa993b | 163 | LOCAL FUNCTION |
c906108c | 164 | |
c5aa993b | 165 | elf_symtab_read -- read the symbol table of an ELF file |
c906108c | 166 | |
c5aa993b | 167 | SYNOPSIS |
c906108c | 168 | |
d4f3574e | 169 | void elf_symtab_read (struct objfile *objfile, int dynamic) |
c906108c | 170 | |
c5aa993b | 171 | DESCRIPTION |
c906108c | 172 | |
d4f3574e SS |
173 | Given an objfile and a flag that specifies whether or not the objfile |
174 | is for an executable or not (may be shared library for example), add | |
175 | all the global function and data symbols to the minimal symbol table. | |
c906108c | 176 | |
c5aa993b JM |
177 | In stabs-in-ELF, as implemented by Sun, there are some local symbols |
178 | defined in the ELF symbol table, which can be used to locate | |
179 | the beginnings of sections from each ".o" file that was linked to | |
180 | form the executable objfile. We gather any such info and record it | |
181 | in data structures hung off the objfile's private data. | |
c906108c | 182 | |
c5aa993b | 183 | */ |
c906108c SS |
184 | |
185 | static void | |
fba45db2 | 186 | elf_symtab_read (struct objfile *objfile, int dynamic) |
c906108c SS |
187 | { |
188 | long storage_needed; | |
189 | asymbol *sym; | |
190 | asymbol **symbol_table; | |
191 | long number_of_symbols; | |
192 | long i; | |
193 | int index; | |
194 | struct cleanup *back_to; | |
195 | CORE_ADDR symaddr; | |
d4f3574e | 196 | CORE_ADDR offset; |
c906108c SS |
197 | enum minimal_symbol_type ms_type; |
198 | /* If sectinfo is nonNULL, it contains section info that should end up | |
199 | filed in the objfile. */ | |
200 | struct stab_section_info *sectinfo = NULL; | |
201 | /* If filesym is nonzero, it points to a file symbol, but we haven't | |
202 | seen any section info for it yet. */ | |
203 | asymbol *filesym = 0; | |
204 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
205 | /* Name of filesym, as saved on the symbol_obstack. */ | |
206 | char *filesymname = obsavestring ("", 0, &objfile->symbol_obstack); | |
207 | #endif | |
208 | struct dbx_symfile_info *dbx = objfile->sym_stab_info; | |
209 | unsigned long size; | |
d4f3574e | 210 | int stripped = (bfd_get_symcount (objfile->obfd) == 0); |
c5aa993b | 211 | |
c906108c SS |
212 | if (dynamic) |
213 | { | |
d4f3574e | 214 | storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd); |
c906108c SS |
215 | |
216 | /* Nothing to be done if there is no dynamic symtab. */ | |
217 | if (storage_needed < 0) | |
218 | return; | |
219 | } | |
220 | else | |
221 | { | |
d4f3574e | 222 | storage_needed = bfd_get_symtab_upper_bound (objfile->obfd); |
c906108c | 223 | if (storage_needed < 0) |
d4f3574e | 224 | error ("Can't read symbols from %s: %s", bfd_get_filename (objfile->obfd), |
c906108c SS |
225 | bfd_errmsg (bfd_get_error ())); |
226 | } | |
227 | if (storage_needed > 0) | |
228 | { | |
229 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
b8c9b27d | 230 | back_to = make_cleanup (xfree, symbol_table); |
c906108c | 231 | if (dynamic) |
d4f3574e | 232 | number_of_symbols = bfd_canonicalize_dynamic_symtab (objfile->obfd, |
c906108c SS |
233 | symbol_table); |
234 | else | |
d4f3574e | 235 | number_of_symbols = bfd_canonicalize_symtab (objfile->obfd, symbol_table); |
c906108c | 236 | if (number_of_symbols < 0) |
d4f3574e | 237 | error ("Can't read symbols from %s: %s", bfd_get_filename (objfile->obfd), |
c906108c | 238 | bfd_errmsg (bfd_get_error ())); |
b8d39351 | 239 | |
c906108c SS |
240 | for (i = 0; i < number_of_symbols; i++) |
241 | { | |
242 | sym = symbol_table[i]; | |
c5aa993b | 243 | if (sym->name == NULL || *sym->name == '\0') |
c906108c SS |
244 | { |
245 | /* Skip names that don't exist (shouldn't happen), or names | |
c5aa993b | 246 | that are null strings (may happen). */ |
c906108c SS |
247 | continue; |
248 | } | |
249 | ||
b8d39351 | 250 | offset = ANOFFSET (objfile->section_offsets, sym->section->index); |
c906108c | 251 | if (dynamic |
c5aa993b JM |
252 | && sym->section == &bfd_und_section |
253 | && (sym->flags & BSF_FUNCTION)) | |
c906108c SS |
254 | { |
255 | struct minimal_symbol *msym; | |
256 | ||
257 | /* Symbol is a reference to a function defined in | |
c5aa993b JM |
258 | a shared library. |
259 | If its value is non zero then it is usually the address | |
260 | of the corresponding entry in the procedure linkage table, | |
d4f3574e | 261 | plus the desired section offset. |
c5aa993b JM |
262 | If its value is zero then the dynamic linker has to resolve |
263 | the symbol. We are unable to find any meaningful address | |
264 | for this symbol in the executable file, so we skip it. */ | |
265 | symaddr = sym->value; | |
c906108c SS |
266 | if (symaddr == 0) |
267 | continue; | |
d4f3574e | 268 | symaddr += offset; |
c906108c | 269 | msym = record_minimal_symbol_and_info |
c5aa993b JM |
270 | ((char *) sym->name, symaddr, |
271 | mst_solib_trampoline, NULL, sym->section, objfile); | |
c906108c SS |
272 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
273 | if (msym != NULL) | |
274 | msym->filename = filesymname; | |
275 | #endif | |
276 | continue; | |
277 | } | |
278 | ||
279 | /* If it is a nonstripped executable, do not enter dynamic | |
280 | symbols, as the dynamic symbol table is usually a subset | |
281 | of the main symbol table. */ | |
282 | if (dynamic && !stripped) | |
283 | continue; | |
c5aa993b | 284 | if (sym->flags & BSF_FILE) |
c906108c SS |
285 | { |
286 | /* STT_FILE debugging symbol that helps stabs-in-elf debugging. | |
c5aa993b | 287 | Chain any old one onto the objfile; remember new sym. */ |
c906108c SS |
288 | if (sectinfo != NULL) |
289 | { | |
c5aa993b JM |
290 | sectinfo->next = dbx->stab_section_info; |
291 | dbx->stab_section_info = sectinfo; | |
c906108c SS |
292 | sectinfo = NULL; |
293 | } | |
294 | filesym = sym; | |
295 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
296 | filesymname = | |
c5aa993b | 297 | obsavestring ((char *) filesym->name, strlen (filesym->name), |
c906108c SS |
298 | &objfile->symbol_obstack); |
299 | #endif | |
300 | } | |
c5aa993b | 301 | else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK)) |
c906108c SS |
302 | { |
303 | struct minimal_symbol *msym; | |
304 | ||
305 | /* Select global/local/weak symbols. Note that bfd puts abs | |
c5aa993b JM |
306 | symbols in their own section, so all symbols we are |
307 | interested in will have a section. */ | |
c906108c | 308 | /* Bfd symbols are section relative. */ |
c5aa993b | 309 | symaddr = sym->value + sym->section->vma; |
d4f3574e | 310 | /* Relocate all non-absolute symbols by the section offset. */ |
c5aa993b | 311 | if (sym->section != &bfd_abs_section) |
c906108c | 312 | { |
d4f3574e | 313 | symaddr += offset; |
c906108c SS |
314 | } |
315 | /* For non-absolute symbols, use the type of the section | |
c5aa993b JM |
316 | they are relative to, to intuit text/data. Bfd provides |
317 | no way of figuring this out for absolute symbols. */ | |
318 | if (sym->section == &bfd_abs_section) | |
c906108c SS |
319 | { |
320 | /* This is a hack to get the minimal symbol type | |
11cf8741 | 321 | right for Irix 5, which has absolute addresses |
c906108c SS |
322 | with special section indices for dynamic symbols. */ |
323 | unsigned short shndx = | |
c5aa993b | 324 | ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx; |
c906108c SS |
325 | |
326 | switch (shndx) | |
327 | { | |
328 | case SHN_MIPS_TEXT: | |
329 | ms_type = mst_text; | |
330 | break; | |
331 | case SHN_MIPS_DATA: | |
332 | ms_type = mst_data; | |
333 | break; | |
334 | case SHN_MIPS_ACOMMON: | |
335 | ms_type = mst_bss; | |
336 | break; | |
337 | default: | |
338 | ms_type = mst_abs; | |
339 | } | |
340 | ||
341 | /* If it is an Irix dynamic symbol, skip section name | |
d4f3574e | 342 | symbols, relocate all others by section offset. */ |
c906108c SS |
343 | if (ms_type != mst_abs) |
344 | { | |
345 | if (sym->name[0] == '.') | |
346 | continue; | |
d4f3574e | 347 | symaddr += offset; |
c906108c SS |
348 | } |
349 | } | |
c5aa993b | 350 | else if (sym->section->flags & SEC_CODE) |
c906108c | 351 | { |
c5aa993b | 352 | if (sym->flags & BSF_GLOBAL) |
c906108c SS |
353 | { |
354 | ms_type = mst_text; | |
355 | } | |
356 | else if ((sym->name[0] == '.' && sym->name[1] == 'L') | |
c5aa993b | 357 | || ((sym->flags & BSF_LOCAL) |
c906108c SS |
358 | && sym->name[0] == '$' |
359 | && sym->name[1] == 'L')) | |
360 | /* Looks like a compiler-generated label. Skip it. | |
361 | The assembler should be skipping these (to keep | |
362 | executables small), but apparently with gcc on the | |
363 | delta m88k SVR4, it loses. So to have us check too | |
364 | should be harmless (but I encourage people to fix this | |
365 | in the assembler instead of adding checks here). */ | |
366 | continue; | |
c906108c SS |
367 | else |
368 | { | |
369 | ms_type = mst_file_text; | |
370 | } | |
371 | } | |
c5aa993b | 372 | else if (sym->section->flags & SEC_ALLOC) |
c906108c | 373 | { |
bbeae047 | 374 | if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) |
c906108c | 375 | { |
c5aa993b | 376 | if (sym->section->flags & SEC_LOAD) |
c906108c SS |
377 | { |
378 | ms_type = mst_data; | |
379 | } | |
380 | else | |
381 | { | |
382 | ms_type = mst_bss; | |
383 | } | |
384 | } | |
c5aa993b | 385 | else if (sym->flags & BSF_LOCAL) |
c906108c SS |
386 | { |
387 | /* Named Local variable in a Data section. Check its | |
c5aa993b JM |
388 | name for stabs-in-elf. The STREQ macro checks the |
389 | first character inline, so we only actually do a | |
390 | strcmp function call on names that start with 'B' | |
391 | or 'D' */ | |
c906108c | 392 | index = SECT_OFF_MAX; |
c5aa993b | 393 | if (STREQ ("Bbss.bss", sym->name)) |
c906108c | 394 | { |
b8fbeb18 | 395 | index = SECT_OFF_BSS (objfile); |
c906108c | 396 | } |
c5aa993b | 397 | else if (STREQ ("Ddata.data", sym->name)) |
c906108c | 398 | { |
b8fbeb18 | 399 | index = SECT_OFF_DATA (objfile); |
c906108c | 400 | } |
c5aa993b | 401 | else if (STREQ ("Drodata.rodata", sym->name)) |
c906108c | 402 | { |
b8fbeb18 | 403 | index = SECT_OFF_RODATA (objfile); |
c906108c SS |
404 | } |
405 | if (index != SECT_OFF_MAX) | |
406 | { | |
407 | /* Found a special local symbol. Allocate a | |
408 | sectinfo, if needed, and fill it in. */ | |
409 | if (sectinfo == NULL) | |
410 | { | |
411 | sectinfo = (struct stab_section_info *) | |
c5aa993b | 412 | xmmalloc (objfile->md, sizeof (*sectinfo)); |
12b9c64f AO |
413 | memset (sectinfo, 0, |
414 | sizeof (*sectinfo)); | |
c906108c SS |
415 | if (filesym == NULL) |
416 | { | |
417 | complain (§ion_info_complaint, | |
c5aa993b | 418 | sym->name); |
c906108c SS |
419 | } |
420 | else | |
421 | { | |
c5aa993b JM |
422 | sectinfo->filename = |
423 | (char *) filesym->name; | |
c906108c SS |
424 | } |
425 | } | |
a4c8257b EZ |
426 | if (index != -1) |
427 | { | |
428 | if (sectinfo->sections[index] != 0) | |
429 | { | |
430 | complain (§ion_info_dup_complaint, | |
431 | sectinfo->filename); | |
432 | } | |
c906108c | 433 | } |
a4c8257b | 434 | else |
8e65ff28 AC |
435 | internal_error (__FILE__, __LINE__, |
436 | "Section index uninitialized."); | |
c906108c | 437 | /* Bfd symbols are section relative. */ |
c5aa993b | 438 | symaddr = sym->value + sym->section->vma; |
d4f3574e | 439 | /* Relocate non-absolute symbols by the section offset. */ |
c5aa993b | 440 | if (sym->section != &bfd_abs_section) |
c906108c | 441 | { |
d4f3574e | 442 | symaddr += offset; |
c906108c | 443 | } |
a4c8257b EZ |
444 | if (index != -1) |
445 | sectinfo->sections[index] = symaddr; | |
446 | else | |
8e65ff28 AC |
447 | internal_error (__FILE__, __LINE__, |
448 | "Section index uninitialized."); | |
c906108c SS |
449 | /* The special local symbols don't go in the |
450 | minimal symbol table, so ignore this one. */ | |
451 | continue; | |
452 | } | |
453 | /* Not a special stabs-in-elf symbol, do regular | |
c5aa993b JM |
454 | symbol processing. */ |
455 | if (sym->section->flags & SEC_LOAD) | |
c906108c SS |
456 | { |
457 | ms_type = mst_file_data; | |
458 | } | |
459 | else | |
460 | { | |
461 | ms_type = mst_file_bss; | |
462 | } | |
463 | } | |
464 | else | |
465 | { | |
466 | ms_type = mst_unknown; | |
467 | } | |
468 | } | |
469 | else | |
470 | { | |
471 | /* FIXME: Solaris2 shared libraries include lots of | |
472 | odd "absolute" and "undefined" symbols, that play | |
473 | hob with actions like finding what function the PC | |
474 | is in. Ignore them if they aren't text, data, or bss. */ | |
475 | /* ms_type = mst_unknown; */ | |
c5aa993b | 476 | continue; /* Skip this symbol. */ |
c906108c SS |
477 | } |
478 | /* Pass symbol size field in via BFD. FIXME!!! */ | |
c5aa993b | 479 | size = ((elf_symbol_type *) sym)->internal_elf_sym.st_size; |
c906108c | 480 | msym = record_minimal_symbol_and_info |
c5aa993b | 481 | ((char *) sym->name, symaddr, |
12b9c64f | 482 | ms_type, (void *) size, sym->section, objfile); |
c906108c SS |
483 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
484 | if (msym != NULL) | |
485 | msym->filename = filesymname; | |
486 | #endif | |
c5aa993b | 487 | ELF_MAKE_MSYMBOL_SPECIAL (sym, msym); |
c906108c SS |
488 | } |
489 | } | |
490 | do_cleanups (back_to); | |
491 | } | |
492 | } | |
493 | ||
494 | /* Scan and build partial symbols for a symbol file. | |
495 | We have been initialized by a call to elf_symfile_init, which | |
496 | currently does nothing. | |
497 | ||
498 | SECTION_OFFSETS is a set of offsets to apply to relocate the symbols | |
499 | in each section. We simplify it down to a single offset for all | |
500 | symbols. FIXME. | |
501 | ||
502 | MAINLINE is true if we are reading the main symbol | |
503 | table (as opposed to a shared lib or dynamically loaded file). | |
504 | ||
505 | This function only does the minimum work necessary for letting the | |
506 | user "name" things symbolically; it does not read the entire symtab. | |
507 | Instead, it reads the external and static symbols and puts them in partial | |
508 | symbol tables. When more extensive information is requested of a | |
509 | file, the corresponding partial symbol table is mutated into a full | |
510 | fledged symbol table by going back and reading the symbols | |
511 | for real. | |
512 | ||
513 | We look for sections with specific names, to tell us what debug | |
514 | format to look for: FIXME!!! | |
515 | ||
516 | dwarf_build_psymtabs() builds psymtabs for DWARF symbols; | |
517 | elfstab_build_psymtabs() handles STABS symbols; | |
518 | mdebug_build_psymtabs() handles ECOFF debugging information. | |
519 | ||
520 | Note that ELF files have a "minimal" symbol table, which looks a lot | |
521 | like a COFF symbol table, but has only the minimal information necessary | |
522 | for linking. We process this also, and use the information to | |
523 | build gdb's minimal symbol table. This gives us some minimal debugging | |
524 | capability even for files compiled without -g. */ | |
525 | ||
526 | static void | |
fba45db2 | 527 | elf_symfile_read (struct objfile *objfile, int mainline) |
c906108c SS |
528 | { |
529 | bfd *abfd = objfile->obfd; | |
530 | struct elfinfo ei; | |
531 | struct cleanup *back_to; | |
532 | CORE_ADDR offset; | |
533 | ||
534 | init_minimal_symbol_collection (); | |
56e290f4 | 535 | back_to = make_cleanup_discard_minimal_symbols (); |
c906108c SS |
536 | |
537 | memset ((char *) &ei, 0, sizeof (ei)); | |
538 | ||
539 | /* Allocate struct to keep track of the symfile */ | |
540 | objfile->sym_stab_info = (struct dbx_symfile_info *) | |
c5aa993b | 541 | xmmalloc (objfile->md, sizeof (struct dbx_symfile_info)); |
c906108c | 542 | memset ((char *) objfile->sym_stab_info, 0, sizeof (struct dbx_symfile_info)); |
12b9c64f | 543 | make_cleanup (free_elfinfo, (void *) objfile); |
c906108c SS |
544 | |
545 | /* Process the normal ELF symbol table first. This may write some | |
546 | chain of info into the dbx_symfile_info in objfile->sym_stab_info, | |
547 | which can later be used by elfstab_offset_sections. */ | |
548 | ||
d4f3574e | 549 | elf_symtab_read (objfile, 0); |
c906108c SS |
550 | |
551 | /* Add the dynamic symbols. */ | |
552 | ||
d4f3574e | 553 | elf_symtab_read (objfile, 1); |
c906108c SS |
554 | |
555 | /* Now process debugging information, which is contained in | |
556 | special ELF sections. */ | |
557 | ||
558 | /* If we are reinitializing, or if we have never loaded syms yet, | |
559 | set table to empty. MAINLINE is cleared so that *_read_psymtab | |
560 | functions do not all also re-initialize the psymbol table. */ | |
561 | if (mainline) | |
562 | { | |
563 | init_psymbol_list (objfile, 0); | |
564 | mainline = 0; | |
565 | } | |
566 | ||
567 | /* We first have to find them... */ | |
12b9c64f | 568 | bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei); |
c906108c SS |
569 | |
570 | /* ELF debugging information is inserted into the psymtab in the | |
571 | order of least informative first - most informative last. Since | |
572 | the psymtab table is searched `most recent insertion first' this | |
573 | increases the probability that more detailed debug information | |
574 | for a section is found. | |
575 | ||
576 | For instance, an object file might contain both .mdebug (XCOFF) | |
577 | and .debug_info (DWARF2) sections then .mdebug is inserted first | |
578 | (searched last) and DWARF2 is inserted last (searched first). If | |
579 | we don't do this then the XCOFF info is found first - for code in | |
580 | an included file XCOFF info is useless. */ | |
581 | ||
582 | if (ei.mdebugsect) | |
583 | { | |
584 | const struct ecoff_debug_swap *swap; | |
585 | ||
586 | /* .mdebug section, presumably holding ECOFF debugging | |
c5aa993b | 587 | information. */ |
c906108c SS |
588 | swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap; |
589 | if (swap) | |
d4f3574e | 590 | elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect); |
c906108c SS |
591 | } |
592 | if (ei.stabsect) | |
593 | { | |
594 | asection *str_sect; | |
595 | ||
596 | /* Stab sections have an associated string table that looks like | |
c5aa993b | 597 | a separate section. */ |
c906108c SS |
598 | str_sect = bfd_get_section_by_name (abfd, ".stabstr"); |
599 | ||
600 | /* FIXME should probably warn about a stab section without a stabstr. */ | |
601 | if (str_sect) | |
602 | elfstab_build_psymtabs (objfile, | |
c906108c SS |
603 | mainline, |
604 | ei.stabsect->filepos, | |
605 | bfd_section_size (abfd, ei.stabsect), | |
606 | str_sect->filepos, | |
607 | bfd_section_size (abfd, str_sect)); | |
608 | } | |
609 | if (dwarf2_has_info (abfd)) | |
610 | { | |
611 | /* DWARF 2 sections */ | |
d4f3574e | 612 | dwarf2_build_psymtabs (objfile, mainline); |
c906108c SS |
613 | } |
614 | else if (ei.dboffset && ei.lnoffset) | |
615 | { | |
616 | /* DWARF sections */ | |
617 | dwarf_build_psymtabs (objfile, | |
d4f3574e | 618 | mainline, |
c906108c SS |
619 | ei.dboffset, ei.dbsize, |
620 | ei.lnoffset, ei.lnsize); | |
621 | } | |
622 | ||
b6af0555 JS |
623 | if (DWARF2_BUILD_FRAME_INFO_P ()) |
624 | DWARF2_BUILD_FRAME_INFO(objfile); | |
625 | ||
c906108c SS |
626 | /* Install any minimal symbols that have been collected as the current |
627 | minimal symbols for this objfile. */ | |
628 | ||
629 | install_minimal_symbols (objfile); | |
630 | ||
631 | do_cleanups (back_to); | |
632 | } | |
633 | ||
634 | /* This cleans up the objfile's sym_stab_info pointer, and the chain of | |
635 | stab_section_info's, that might be dangling from it. */ | |
636 | ||
637 | static void | |
12b9c64f | 638 | free_elfinfo (void *objp) |
c906108c | 639 | { |
c5aa993b | 640 | struct objfile *objfile = (struct objfile *) objp; |
c906108c SS |
641 | struct dbx_symfile_info *dbxinfo = objfile->sym_stab_info; |
642 | struct stab_section_info *ssi, *nssi; | |
643 | ||
644 | ssi = dbxinfo->stab_section_info; | |
645 | while (ssi) | |
646 | { | |
647 | nssi = ssi->next; | |
aac7f4ea | 648 | xmfree (objfile->md, ssi); |
c906108c SS |
649 | ssi = nssi; |
650 | } | |
651 | ||
652 | dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */ | |
653 | } | |
654 | ||
655 | ||
656 | /* Initialize anything that needs initializing when a completely new symbol | |
657 | file is specified (not just adding some symbols from another file, e.g. a | |
658 | shared library). | |
659 | ||
660 | We reinitialize buildsym, since we may be reading stabs from an ELF file. */ | |
661 | ||
662 | static void | |
fba45db2 | 663 | elf_new_init (struct objfile *ignore) |
c906108c SS |
664 | { |
665 | stabsread_new_init (); | |
666 | buildsym_new_init (); | |
667 | } | |
668 | ||
669 | /* Perform any local cleanups required when we are done with a particular | |
670 | objfile. I.E, we are in the process of discarding all symbol information | |
671 | for an objfile, freeing up all memory held for it, and unlinking the | |
672 | objfile struct from the global list of known objfiles. */ | |
673 | ||
674 | static void | |
fba45db2 | 675 | elf_symfile_finish (struct objfile *objfile) |
c906108c | 676 | { |
c5aa993b | 677 | if (objfile->sym_stab_info != NULL) |
c906108c | 678 | { |
aac7f4ea | 679 | xmfree (objfile->md, objfile->sym_stab_info); |
c906108c SS |
680 | } |
681 | } | |
682 | ||
683 | /* ELF specific initialization routine for reading symbols. | |
684 | ||
685 | It is passed a pointer to a struct sym_fns which contains, among other | |
686 | things, the BFD for the file whose symbols are being read, and a slot for | |
687 | a pointer to "private data" which we can fill with goodies. | |
688 | ||
689 | For now at least, we have nothing in particular to do, so this function is | |
690 | just a stub. */ | |
691 | ||
692 | static void | |
fba45db2 | 693 | elf_symfile_init (struct objfile *objfile) |
c906108c SS |
694 | { |
695 | /* ELF objects may be reordered, so set OBJF_REORDERED. If we | |
696 | find this causes a significant slowdown in gdb then we could | |
697 | set it in the debug symbol readers only when necessary. */ | |
698 | objfile->flags |= OBJF_REORDERED; | |
699 | } | |
700 | ||
701 | /* When handling an ELF file that contains Sun STABS debug info, | |
702 | some of the debug info is relative to the particular chunk of the | |
703 | section that was generated in its individual .o file. E.g. | |
704 | offsets to static variables are relative to the start of the data | |
705 | segment *for that module before linking*. This information is | |
706 | painfully squirreled away in the ELF symbol table as local symbols | |
707 | with wierd names. Go get 'em when needed. */ | |
708 | ||
709 | void | |
fba45db2 | 710 | elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst) |
c906108c SS |
711 | { |
712 | char *filename = pst->filename; | |
713 | struct dbx_symfile_info *dbx = objfile->sym_stab_info; | |
714 | struct stab_section_info *maybe = dbx->stab_section_info; | |
715 | struct stab_section_info *questionable = 0; | |
716 | int i; | |
717 | char *p; | |
718 | ||
719 | /* The ELF symbol info doesn't include path names, so strip the path | |
720 | (if any) from the psymtab filename. */ | |
721 | while (0 != (p = strchr (filename, '/'))) | |
c5aa993b | 722 | filename = p + 1; |
c906108c SS |
723 | |
724 | /* FIXME: This linear search could speed up significantly | |
725 | if it was chained in the right order to match how we search it, | |
726 | and if we unchained when we found a match. */ | |
727 | for (; maybe; maybe = maybe->next) | |
728 | { | |
729 | if (filename[0] == maybe->filename[0] | |
730 | && STREQ (filename, maybe->filename)) | |
731 | { | |
732 | /* We found a match. But there might be several source files | |
733 | (from different directories) with the same name. */ | |
734 | if (0 == maybe->found) | |
735 | break; | |
c5aa993b | 736 | questionable = maybe; /* Might use it later. */ |
c906108c SS |
737 | } |
738 | } | |
739 | ||
740 | if (maybe == 0 && questionable != 0) | |
741 | { | |
742 | complain (&stab_info_questionable_complaint, filename); | |
743 | maybe = questionable; | |
744 | } | |
745 | ||
746 | if (maybe) | |
747 | { | |
748 | /* Found it! Allocate a new psymtab struct, and fill it in. */ | |
749 | maybe->found++; | |
750 | pst->section_offsets = (struct section_offsets *) | |
96baa820 | 751 | obstack_alloc (&objfile->psymbol_obstack, SIZEOF_SECTION_OFFSETS); |
c906108c | 752 | for (i = 0; i < SECT_OFF_MAX; i++) |
a4c8257b | 753 | (pst->section_offsets)->offsets[i] = maybe->sections[i]; |
c906108c SS |
754 | return; |
755 | } | |
756 | ||
757 | /* We were unable to find any offsets for this file. Complain. */ | |
c5aa993b | 758 | if (dbx->stab_section_info) /* If there *is* any info, */ |
c906108c SS |
759 | complain (&stab_info_mismatch_complaint, filename); |
760 | } | |
761 | \f | |
762 | /* Register that we are able to handle ELF object file formats. */ | |
763 | ||
764 | static struct sym_fns elf_sym_fns = | |
765 | { | |
766 | bfd_target_elf_flavour, | |
c5aa993b JM |
767 | elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ |
768 | elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ | |
769 | elf_symfile_read, /* sym_read: read a symbol file into symtab */ | |
770 | elf_symfile_finish, /* sym_finish: finished with file, cleanup */ | |
96baa820 | 771 | default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ |
c5aa993b | 772 | NULL /* next: pointer to next struct sym_fns */ |
c906108c SS |
773 | }; |
774 | ||
775 | void | |
fba45db2 | 776 | _initialize_elfread (void) |
c906108c SS |
777 | { |
778 | add_symtab_fns (&elf_sym_fns); | |
779 | } |