Commit | Line | Data |
---|---|---|
c906108c | 1 | /* Read ELF (Executable and Linking Format) object files for GDB. |
1bac305b AC |
2 | |
3 | Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, | |
4 | 2000, 2001, 2002, 2003 Free Software Foundation, Inc. | |
5 | ||
c906108c SS |
6 | Written by Fred Fish at Cygnus Support. |
7 | ||
c5aa993b | 8 | This file is part of GDB. |
c906108c | 9 | |
c5aa993b JM |
10 | This program is free software; you can redistribute it and/or modify |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 2 of the License, or | |
13 | (at your option) any later version. | |
c906108c | 14 | |
c5aa993b JM |
15 | This program is distributed in the hope that it will be useful, |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
c906108c | 19 | |
c5aa993b JM |
20 | You should have received a copy of the GNU General Public License |
21 | along with this program; if not, write to the Free Software | |
22 | Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
24 | |
25 | #include "defs.h" | |
26 | #include "bfd.h" | |
27 | #include "gdb_string.h" | |
28 | #include "elf-bfd.h" | |
29 | #include "elf/mips.h" | |
30 | #include "symtab.h" | |
31 | #include "symfile.h" | |
32 | #include "objfiles.h" | |
33 | #include "buildsym.h" | |
34 | #include "stabsread.h" | |
35 | #include "gdb-stabs.h" | |
36 | #include "complaints.h" | |
37 | #include "demangle.h" | |
38 | ||
a14ed312 | 39 | extern void _initialize_elfread (void); |
392a587b | 40 | |
c906108c | 41 | /* The struct elfinfo is available only during ELF symbol table and |
6426a772 | 42 | psymtab reading. It is destroyed at the completion of psymtab-reading. |
c906108c SS |
43 | It's local to elf_symfile_read. */ |
44 | ||
c5aa993b JM |
45 | struct elfinfo |
46 | { | |
47 | file_ptr dboffset; /* Offset to dwarf debug section */ | |
48 | unsigned int dbsize; /* Size of dwarf debug section */ | |
49 | file_ptr lnoffset; /* Offset to dwarf line number section */ | |
50 | unsigned int lnsize; /* Size of dwarf line number section */ | |
51 | asection *stabsect; /* Section pointer for .stab section */ | |
52 | asection *stabindexsect; /* Section pointer for .stab.index section */ | |
53 | asection *mdebugsect; /* Section pointer for .mdebug section */ | |
54 | }; | |
c906108c | 55 | |
12b9c64f | 56 | static void free_elfinfo (void *); |
c906108c SS |
57 | |
58 | /* We are called once per section from elf_symfile_read. We | |
59 | need to examine each section we are passed, check to see | |
60 | if it is something we are interested in processing, and | |
61 | if so, stash away some access information for the section. | |
62 | ||
63 | For now we recognize the dwarf debug information sections and | |
64 | line number sections from matching their section names. The | |
65 | ELF definition is no real help here since it has no direct | |
66 | knowledge of DWARF (by design, so any debugging format can be | |
67 | used). | |
68 | ||
69 | We also recognize the ".stab" sections used by the Sun compilers | |
70 | released with Solaris 2. | |
71 | ||
72 | FIXME: The section names should not be hardwired strings (what | |
73 | should they be? I don't think most object file formats have enough | |
74 | section flags to specify what kind of debug section it is | |
75 | -kingdon). */ | |
76 | ||
77 | static void | |
12b9c64f | 78 | elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip) |
c906108c SS |
79 | { |
80 | register struct elfinfo *ei; | |
81 | ||
82 | ei = (struct elfinfo *) eip; | |
c5aa993b | 83 | if (STREQ (sectp->name, ".debug")) |
c906108c | 84 | { |
c5aa993b JM |
85 | ei->dboffset = sectp->filepos; |
86 | ei->dbsize = bfd_get_section_size_before_reloc (sectp); | |
c906108c | 87 | } |
c5aa993b | 88 | else if (STREQ (sectp->name, ".line")) |
c906108c | 89 | { |
c5aa993b JM |
90 | ei->lnoffset = sectp->filepos; |
91 | ei->lnsize = bfd_get_section_size_before_reloc (sectp); | |
c906108c | 92 | } |
c5aa993b | 93 | else if (STREQ (sectp->name, ".stab")) |
c906108c | 94 | { |
c5aa993b | 95 | ei->stabsect = sectp; |
c906108c | 96 | } |
c5aa993b | 97 | else if (STREQ (sectp->name, ".stab.index")) |
c906108c | 98 | { |
c5aa993b | 99 | ei->stabindexsect = sectp; |
c906108c | 100 | } |
c5aa993b | 101 | else if (STREQ (sectp->name, ".mdebug")) |
c906108c | 102 | { |
c5aa993b | 103 | ei->mdebugsect = sectp; |
c906108c SS |
104 | } |
105 | } | |
106 | ||
c5aa993b | 107 | #if 0 /* Currently unused */ |
c906108c SS |
108 | |
109 | char * | |
fba45db2 | 110 | elf_interpreter (bfd *abfd) |
c906108c SS |
111 | { |
112 | sec_ptr interp_sec; | |
113 | unsigned size; | |
114 | char *interp = NULL; | |
115 | ||
116 | interp_sec = bfd_get_section_by_name (abfd, ".interp"); | |
117 | if (interp_sec) | |
118 | { | |
119 | size = bfd_section_size (abfd, interp_sec); | |
120 | interp = alloca (size); | |
c5aa993b | 121 | if (bfd_get_section_contents (abfd, interp_sec, interp, (file_ptr) 0, |
c906108c SS |
122 | size)) |
123 | { | |
124 | interp = savestring (interp, size - 1); | |
125 | } | |
126 | else | |
127 | { | |
128 | interp = NULL; | |
129 | } | |
130 | } | |
131 | return (interp); | |
132 | } | |
133 | ||
134 | #endif | |
135 | ||
136 | static struct minimal_symbol * | |
fba45db2 KB |
137 | record_minimal_symbol_and_info (char *name, CORE_ADDR address, |
138 | enum minimal_symbol_type ms_type, char *info, /* FIXME, is this really char *? */ | |
139 | asection *bfd_section, struct objfile *objfile) | |
c906108c | 140 | { |
bbeae047 | 141 | if (ms_type == mst_text || ms_type == mst_file_text) |
181c1381 | 142 | address = SMASH_TEXT_ADDRESS (address); |
c906108c SS |
143 | |
144 | return prim_record_minimal_symbol_and_info | |
bbeae047 | 145 | (name, address, ms_type, info, bfd_section->index, bfd_section, objfile); |
c906108c SS |
146 | } |
147 | ||
148 | /* | |
149 | ||
c5aa993b | 150 | LOCAL FUNCTION |
c906108c | 151 | |
c5aa993b | 152 | elf_symtab_read -- read the symbol table of an ELF file |
c906108c | 153 | |
c5aa993b | 154 | SYNOPSIS |
c906108c | 155 | |
d4f3574e | 156 | void elf_symtab_read (struct objfile *objfile, int dynamic) |
c906108c | 157 | |
c5aa993b | 158 | DESCRIPTION |
c906108c | 159 | |
d4f3574e SS |
160 | Given an objfile and a flag that specifies whether or not the objfile |
161 | is for an executable or not (may be shared library for example), add | |
162 | all the global function and data symbols to the minimal symbol table. | |
c906108c | 163 | |
c5aa993b JM |
164 | In stabs-in-ELF, as implemented by Sun, there are some local symbols |
165 | defined in the ELF symbol table, which can be used to locate | |
166 | the beginnings of sections from each ".o" file that was linked to | |
167 | form the executable objfile. We gather any such info and record it | |
168 | in data structures hung off the objfile's private data. | |
c906108c | 169 | |
c5aa993b | 170 | */ |
c906108c SS |
171 | |
172 | static void | |
fba45db2 | 173 | elf_symtab_read (struct objfile *objfile, int dynamic) |
c906108c SS |
174 | { |
175 | long storage_needed; | |
176 | asymbol *sym; | |
177 | asymbol **symbol_table; | |
178 | long number_of_symbols; | |
179 | long i; | |
180 | int index; | |
181 | struct cleanup *back_to; | |
182 | CORE_ADDR symaddr; | |
d4f3574e | 183 | CORE_ADDR offset; |
c906108c SS |
184 | enum minimal_symbol_type ms_type; |
185 | /* If sectinfo is nonNULL, it contains section info that should end up | |
186 | filed in the objfile. */ | |
187 | struct stab_section_info *sectinfo = NULL; | |
188 | /* If filesym is nonzero, it points to a file symbol, but we haven't | |
189 | seen any section info for it yet. */ | |
190 | asymbol *filesym = 0; | |
191 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
192 | /* Name of filesym, as saved on the symbol_obstack. */ | |
193 | char *filesymname = obsavestring ("", 0, &objfile->symbol_obstack); | |
194 | #endif | |
195 | struct dbx_symfile_info *dbx = objfile->sym_stab_info; | |
196 | unsigned long size; | |
d4f3574e | 197 | int stripped = (bfd_get_symcount (objfile->obfd) == 0); |
c5aa993b | 198 | |
c906108c SS |
199 | if (dynamic) |
200 | { | |
d4f3574e | 201 | storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd); |
c906108c SS |
202 | |
203 | /* Nothing to be done if there is no dynamic symtab. */ | |
204 | if (storage_needed < 0) | |
205 | return; | |
206 | } | |
207 | else | |
208 | { | |
d4f3574e | 209 | storage_needed = bfd_get_symtab_upper_bound (objfile->obfd); |
c906108c | 210 | if (storage_needed < 0) |
d4f3574e | 211 | error ("Can't read symbols from %s: %s", bfd_get_filename (objfile->obfd), |
c906108c SS |
212 | bfd_errmsg (bfd_get_error ())); |
213 | } | |
214 | if (storage_needed > 0) | |
215 | { | |
216 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
b8c9b27d | 217 | back_to = make_cleanup (xfree, symbol_table); |
c906108c | 218 | if (dynamic) |
d4f3574e | 219 | number_of_symbols = bfd_canonicalize_dynamic_symtab (objfile->obfd, |
c906108c SS |
220 | symbol_table); |
221 | else | |
d4f3574e | 222 | number_of_symbols = bfd_canonicalize_symtab (objfile->obfd, symbol_table); |
c906108c | 223 | if (number_of_symbols < 0) |
d4f3574e | 224 | error ("Can't read symbols from %s: %s", bfd_get_filename (objfile->obfd), |
c906108c | 225 | bfd_errmsg (bfd_get_error ())); |
b8d39351 | 226 | |
c906108c SS |
227 | for (i = 0; i < number_of_symbols; i++) |
228 | { | |
229 | sym = symbol_table[i]; | |
c5aa993b | 230 | if (sym->name == NULL || *sym->name == '\0') |
c906108c SS |
231 | { |
232 | /* Skip names that don't exist (shouldn't happen), or names | |
c5aa993b | 233 | that are null strings (may happen). */ |
c906108c SS |
234 | continue; |
235 | } | |
236 | ||
b8d39351 | 237 | offset = ANOFFSET (objfile->section_offsets, sym->section->index); |
c906108c | 238 | if (dynamic |
c5aa993b JM |
239 | && sym->section == &bfd_und_section |
240 | && (sym->flags & BSF_FUNCTION)) | |
c906108c SS |
241 | { |
242 | struct minimal_symbol *msym; | |
243 | ||
244 | /* Symbol is a reference to a function defined in | |
c5aa993b JM |
245 | a shared library. |
246 | If its value is non zero then it is usually the address | |
247 | of the corresponding entry in the procedure linkage table, | |
d4f3574e | 248 | plus the desired section offset. |
c5aa993b JM |
249 | If its value is zero then the dynamic linker has to resolve |
250 | the symbol. We are unable to find any meaningful address | |
251 | for this symbol in the executable file, so we skip it. */ | |
252 | symaddr = sym->value; | |
c906108c SS |
253 | if (symaddr == 0) |
254 | continue; | |
d4f3574e | 255 | symaddr += offset; |
c906108c | 256 | msym = record_minimal_symbol_and_info |
c5aa993b JM |
257 | ((char *) sym->name, symaddr, |
258 | mst_solib_trampoline, NULL, sym->section, objfile); | |
c906108c SS |
259 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
260 | if (msym != NULL) | |
261 | msym->filename = filesymname; | |
262 | #endif | |
263 | continue; | |
264 | } | |
265 | ||
266 | /* If it is a nonstripped executable, do not enter dynamic | |
267 | symbols, as the dynamic symbol table is usually a subset | |
268 | of the main symbol table. */ | |
269 | if (dynamic && !stripped) | |
270 | continue; | |
c5aa993b | 271 | if (sym->flags & BSF_FILE) |
c906108c SS |
272 | { |
273 | /* STT_FILE debugging symbol that helps stabs-in-elf debugging. | |
c5aa993b | 274 | Chain any old one onto the objfile; remember new sym. */ |
c906108c SS |
275 | if (sectinfo != NULL) |
276 | { | |
c5aa993b JM |
277 | sectinfo->next = dbx->stab_section_info; |
278 | dbx->stab_section_info = sectinfo; | |
c906108c SS |
279 | sectinfo = NULL; |
280 | } | |
281 | filesym = sym; | |
282 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING | |
283 | filesymname = | |
c5aa993b | 284 | obsavestring ((char *) filesym->name, strlen (filesym->name), |
c906108c SS |
285 | &objfile->symbol_obstack); |
286 | #endif | |
287 | } | |
c5aa993b | 288 | else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK)) |
c906108c SS |
289 | { |
290 | struct minimal_symbol *msym; | |
291 | ||
292 | /* Select global/local/weak symbols. Note that bfd puts abs | |
c5aa993b JM |
293 | symbols in their own section, so all symbols we are |
294 | interested in will have a section. */ | |
c906108c | 295 | /* Bfd symbols are section relative. */ |
c5aa993b | 296 | symaddr = sym->value + sym->section->vma; |
d4f3574e | 297 | /* Relocate all non-absolute symbols by the section offset. */ |
c5aa993b | 298 | if (sym->section != &bfd_abs_section) |
c906108c | 299 | { |
d4f3574e | 300 | symaddr += offset; |
c906108c SS |
301 | } |
302 | /* For non-absolute symbols, use the type of the section | |
c5aa993b JM |
303 | they are relative to, to intuit text/data. Bfd provides |
304 | no way of figuring this out for absolute symbols. */ | |
305 | if (sym->section == &bfd_abs_section) | |
c906108c SS |
306 | { |
307 | /* This is a hack to get the minimal symbol type | |
11cf8741 | 308 | right for Irix 5, which has absolute addresses |
c906108c SS |
309 | with special section indices for dynamic symbols. */ |
310 | unsigned short shndx = | |
c5aa993b | 311 | ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx; |
c906108c SS |
312 | |
313 | switch (shndx) | |
314 | { | |
315 | case SHN_MIPS_TEXT: | |
316 | ms_type = mst_text; | |
317 | break; | |
318 | case SHN_MIPS_DATA: | |
319 | ms_type = mst_data; | |
320 | break; | |
321 | case SHN_MIPS_ACOMMON: | |
322 | ms_type = mst_bss; | |
323 | break; | |
324 | default: | |
325 | ms_type = mst_abs; | |
326 | } | |
327 | ||
328 | /* If it is an Irix dynamic symbol, skip section name | |
d4f3574e | 329 | symbols, relocate all others by section offset. */ |
c906108c SS |
330 | if (ms_type != mst_abs) |
331 | { | |
332 | if (sym->name[0] == '.') | |
333 | continue; | |
d4f3574e | 334 | symaddr += offset; |
c906108c SS |
335 | } |
336 | } | |
c5aa993b | 337 | else if (sym->section->flags & SEC_CODE) |
c906108c | 338 | { |
389e51db | 339 | if (sym->flags & BSF_GLOBAL) |
c906108c SS |
340 | { |
341 | ms_type = mst_text; | |
342 | } | |
343 | else if ((sym->name[0] == '.' && sym->name[1] == 'L') | |
c5aa993b | 344 | || ((sym->flags & BSF_LOCAL) |
c906108c SS |
345 | && sym->name[0] == '$' |
346 | && sym->name[1] == 'L')) | |
7fb623f7 AC |
347 | /* Looks like a compiler-generated label. Skip |
348 | it. The assembler should be skipping these (to | |
349 | keep executables small), but apparently with | |
1b831c93 AC |
350 | gcc on the (deleted) delta m88k SVR4, it loses. |
351 | So to have us check too should be harmless (but | |
352 | I encourage people to fix this in the assembler | |
353 | instead of adding checks here). */ | |
c906108c | 354 | continue; |
c906108c SS |
355 | else |
356 | { | |
357 | ms_type = mst_file_text; | |
358 | } | |
359 | } | |
c5aa993b | 360 | else if (sym->section->flags & SEC_ALLOC) |
c906108c | 361 | { |
bbeae047 | 362 | if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) |
c906108c | 363 | { |
c5aa993b | 364 | if (sym->section->flags & SEC_LOAD) |
c906108c SS |
365 | { |
366 | ms_type = mst_data; | |
367 | } | |
368 | else | |
369 | { | |
370 | ms_type = mst_bss; | |
371 | } | |
372 | } | |
c5aa993b | 373 | else if (sym->flags & BSF_LOCAL) |
c906108c SS |
374 | { |
375 | /* Named Local variable in a Data section. Check its | |
c5aa993b JM |
376 | name for stabs-in-elf. The STREQ macro checks the |
377 | first character inline, so we only actually do a | |
378 | strcmp function call on names that start with 'B' | |
379 | or 'D' */ | |
c906108c | 380 | index = SECT_OFF_MAX; |
c5aa993b | 381 | if (STREQ ("Bbss.bss", sym->name)) |
c906108c | 382 | { |
b8fbeb18 | 383 | index = SECT_OFF_BSS (objfile); |
c906108c | 384 | } |
c5aa993b | 385 | else if (STREQ ("Ddata.data", sym->name)) |
c906108c | 386 | { |
b8fbeb18 | 387 | index = SECT_OFF_DATA (objfile); |
c906108c | 388 | } |
c5aa993b | 389 | else if (STREQ ("Drodata.rodata", sym->name)) |
c906108c | 390 | { |
b8fbeb18 | 391 | index = SECT_OFF_RODATA (objfile); |
c906108c SS |
392 | } |
393 | if (index != SECT_OFF_MAX) | |
394 | { | |
395 | /* Found a special local symbol. Allocate a | |
396 | sectinfo, if needed, and fill it in. */ | |
397 | if (sectinfo == NULL) | |
398 | { | |
399 | sectinfo = (struct stab_section_info *) | |
c5aa993b | 400 | xmmalloc (objfile->md, sizeof (*sectinfo)); |
12b9c64f AO |
401 | memset (sectinfo, 0, |
402 | sizeof (*sectinfo)); | |
c906108c SS |
403 | if (filesym == NULL) |
404 | { | |
23136709 KB |
405 | complaint (&symfile_complaints, |
406 | "elf/stab section information %s without a preceding file symbol", | |
407 | sym->name); | |
c906108c SS |
408 | } |
409 | else | |
410 | { | |
c5aa993b JM |
411 | sectinfo->filename = |
412 | (char *) filesym->name; | |
c906108c SS |
413 | } |
414 | } | |
a4c8257b EZ |
415 | if (index != -1) |
416 | { | |
417 | if (sectinfo->sections[index] != 0) | |
418 | { | |
23136709 KB |
419 | complaint (&symfile_complaints, |
420 | "duplicated elf/stab section information for %s", | |
421 | sectinfo->filename); | |
a4c8257b | 422 | } |
c906108c | 423 | } |
a4c8257b | 424 | else |
8e65ff28 AC |
425 | internal_error (__FILE__, __LINE__, |
426 | "Section index uninitialized."); | |
c906108c | 427 | /* Bfd symbols are section relative. */ |
c5aa993b | 428 | symaddr = sym->value + sym->section->vma; |
d4f3574e | 429 | /* Relocate non-absolute symbols by the section offset. */ |
c5aa993b | 430 | if (sym->section != &bfd_abs_section) |
c906108c | 431 | { |
d4f3574e | 432 | symaddr += offset; |
c906108c | 433 | } |
a4c8257b EZ |
434 | if (index != -1) |
435 | sectinfo->sections[index] = symaddr; | |
436 | else | |
8e65ff28 AC |
437 | internal_error (__FILE__, __LINE__, |
438 | "Section index uninitialized."); | |
c906108c SS |
439 | /* The special local symbols don't go in the |
440 | minimal symbol table, so ignore this one. */ | |
441 | continue; | |
442 | } | |
443 | /* Not a special stabs-in-elf symbol, do regular | |
c5aa993b JM |
444 | symbol processing. */ |
445 | if (sym->section->flags & SEC_LOAD) | |
c906108c SS |
446 | { |
447 | ms_type = mst_file_data; | |
448 | } | |
449 | else | |
450 | { | |
451 | ms_type = mst_file_bss; | |
452 | } | |
453 | } | |
454 | else | |
455 | { | |
456 | ms_type = mst_unknown; | |
457 | } | |
458 | } | |
459 | else | |
460 | { | |
461 | /* FIXME: Solaris2 shared libraries include lots of | |
462 | odd "absolute" and "undefined" symbols, that play | |
463 | hob with actions like finding what function the PC | |
464 | is in. Ignore them if they aren't text, data, or bss. */ | |
465 | /* ms_type = mst_unknown; */ | |
c5aa993b | 466 | continue; /* Skip this symbol. */ |
c906108c SS |
467 | } |
468 | /* Pass symbol size field in via BFD. FIXME!!! */ | |
c5aa993b | 469 | size = ((elf_symbol_type *) sym)->internal_elf_sym.st_size; |
c906108c | 470 | msym = record_minimal_symbol_and_info |
c5aa993b | 471 | ((char *) sym->name, symaddr, |
12b9c64f | 472 | ms_type, (void *) size, sym->section, objfile); |
c906108c SS |
473 | #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
474 | if (msym != NULL) | |
475 | msym->filename = filesymname; | |
476 | #endif | |
c5aa993b | 477 | ELF_MAKE_MSYMBOL_SPECIAL (sym, msym); |
c906108c SS |
478 | } |
479 | } | |
480 | do_cleanups (back_to); | |
481 | } | |
482 | } | |
483 | ||
484 | /* Scan and build partial symbols for a symbol file. | |
485 | We have been initialized by a call to elf_symfile_init, which | |
486 | currently does nothing. | |
487 | ||
488 | SECTION_OFFSETS is a set of offsets to apply to relocate the symbols | |
489 | in each section. We simplify it down to a single offset for all | |
490 | symbols. FIXME. | |
491 | ||
492 | MAINLINE is true if we are reading the main symbol | |
493 | table (as opposed to a shared lib or dynamically loaded file). | |
494 | ||
495 | This function only does the minimum work necessary for letting the | |
496 | user "name" things symbolically; it does not read the entire symtab. | |
497 | Instead, it reads the external and static symbols and puts them in partial | |
498 | symbol tables. When more extensive information is requested of a | |
499 | file, the corresponding partial symbol table is mutated into a full | |
500 | fledged symbol table by going back and reading the symbols | |
501 | for real. | |
502 | ||
503 | We look for sections with specific names, to tell us what debug | |
504 | format to look for: FIXME!!! | |
505 | ||
506 | dwarf_build_psymtabs() builds psymtabs for DWARF symbols; | |
507 | elfstab_build_psymtabs() handles STABS symbols; | |
508 | mdebug_build_psymtabs() handles ECOFF debugging information. | |
509 | ||
510 | Note that ELF files have a "minimal" symbol table, which looks a lot | |
511 | like a COFF symbol table, but has only the minimal information necessary | |
512 | for linking. We process this also, and use the information to | |
513 | build gdb's minimal symbol table. This gives us some minimal debugging | |
514 | capability even for files compiled without -g. */ | |
515 | ||
516 | static void | |
fba45db2 | 517 | elf_symfile_read (struct objfile *objfile, int mainline) |
c906108c SS |
518 | { |
519 | bfd *abfd = objfile->obfd; | |
520 | struct elfinfo ei; | |
521 | struct cleanup *back_to; | |
522 | CORE_ADDR offset; | |
523 | ||
524 | init_minimal_symbol_collection (); | |
56e290f4 | 525 | back_to = make_cleanup_discard_minimal_symbols (); |
c906108c SS |
526 | |
527 | memset ((char *) &ei, 0, sizeof (ei)); | |
528 | ||
529 | /* Allocate struct to keep track of the symfile */ | |
530 | objfile->sym_stab_info = (struct dbx_symfile_info *) | |
c5aa993b | 531 | xmmalloc (objfile->md, sizeof (struct dbx_symfile_info)); |
c906108c | 532 | memset ((char *) objfile->sym_stab_info, 0, sizeof (struct dbx_symfile_info)); |
12b9c64f | 533 | make_cleanup (free_elfinfo, (void *) objfile); |
c906108c SS |
534 | |
535 | /* Process the normal ELF symbol table first. This may write some | |
536 | chain of info into the dbx_symfile_info in objfile->sym_stab_info, | |
537 | which can later be used by elfstab_offset_sections. */ | |
538 | ||
d4f3574e | 539 | elf_symtab_read (objfile, 0); |
c906108c SS |
540 | |
541 | /* Add the dynamic symbols. */ | |
542 | ||
d4f3574e | 543 | elf_symtab_read (objfile, 1); |
c906108c | 544 | |
7134143f DJ |
545 | /* Install any minimal symbols that have been collected as the current |
546 | minimal symbols for this objfile. The debug readers below this point | |
547 | should not generate new minimal symbols; if they do it's their | |
548 | responsibility to install them. "mdebug" appears to be the only one | |
549 | which will do this. */ | |
550 | ||
551 | install_minimal_symbols (objfile); | |
552 | do_cleanups (back_to); | |
553 | ||
c906108c SS |
554 | /* Now process debugging information, which is contained in |
555 | special ELF sections. */ | |
556 | ||
557 | /* If we are reinitializing, or if we have never loaded syms yet, | |
558 | set table to empty. MAINLINE is cleared so that *_read_psymtab | |
559 | functions do not all also re-initialize the psymbol table. */ | |
560 | if (mainline) | |
561 | { | |
562 | init_psymbol_list (objfile, 0); | |
563 | mainline = 0; | |
564 | } | |
565 | ||
566 | /* We first have to find them... */ | |
12b9c64f | 567 | bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei); |
c906108c SS |
568 | |
569 | /* ELF debugging information is inserted into the psymtab in the | |
570 | order of least informative first - most informative last. Since | |
571 | the psymtab table is searched `most recent insertion first' this | |
572 | increases the probability that more detailed debug information | |
573 | for a section is found. | |
574 | ||
575 | For instance, an object file might contain both .mdebug (XCOFF) | |
576 | and .debug_info (DWARF2) sections then .mdebug is inserted first | |
577 | (searched last) and DWARF2 is inserted last (searched first). If | |
578 | we don't do this then the XCOFF info is found first - for code in | |
579 | an included file XCOFF info is useless. */ | |
580 | ||
581 | if (ei.mdebugsect) | |
582 | { | |
583 | const struct ecoff_debug_swap *swap; | |
584 | ||
585 | /* .mdebug section, presumably holding ECOFF debugging | |
c5aa993b | 586 | information. */ |
c906108c SS |
587 | swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap; |
588 | if (swap) | |
d4f3574e | 589 | elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect); |
c906108c SS |
590 | } |
591 | if (ei.stabsect) | |
592 | { | |
593 | asection *str_sect; | |
594 | ||
595 | /* Stab sections have an associated string table that looks like | |
c5aa993b | 596 | a separate section. */ |
c906108c SS |
597 | str_sect = bfd_get_section_by_name (abfd, ".stabstr"); |
598 | ||
599 | /* FIXME should probably warn about a stab section without a stabstr. */ | |
600 | if (str_sect) | |
601 | elfstab_build_psymtabs (objfile, | |
c906108c | 602 | mainline, |
086df311 | 603 | ei.stabsect, |
c906108c SS |
604 | str_sect->filepos, |
605 | bfd_section_size (abfd, str_sect)); | |
606 | } | |
607 | if (dwarf2_has_info (abfd)) | |
608 | { | |
609 | /* DWARF 2 sections */ | |
d4f3574e | 610 | dwarf2_build_psymtabs (objfile, mainline); |
c906108c SS |
611 | } |
612 | else if (ei.dboffset && ei.lnoffset) | |
613 | { | |
614 | /* DWARF sections */ | |
615 | dwarf_build_psymtabs (objfile, | |
d4f3574e | 616 | mainline, |
c906108c SS |
617 | ei.dboffset, ei.dbsize, |
618 | ei.lnoffset, ei.lnsize); | |
619 | } | |
620 | ||
b6af0555 JS |
621 | if (DWARF2_BUILD_FRAME_INFO_P ()) |
622 | DWARF2_BUILD_FRAME_INFO(objfile); | |
c906108c SS |
623 | } |
624 | ||
625 | /* This cleans up the objfile's sym_stab_info pointer, and the chain of | |
626 | stab_section_info's, that might be dangling from it. */ | |
627 | ||
628 | static void | |
12b9c64f | 629 | free_elfinfo (void *objp) |
c906108c | 630 | { |
c5aa993b | 631 | struct objfile *objfile = (struct objfile *) objp; |
c906108c SS |
632 | struct dbx_symfile_info *dbxinfo = objfile->sym_stab_info; |
633 | struct stab_section_info *ssi, *nssi; | |
634 | ||
635 | ssi = dbxinfo->stab_section_info; | |
636 | while (ssi) | |
637 | { | |
638 | nssi = ssi->next; | |
aac7f4ea | 639 | xmfree (objfile->md, ssi); |
c906108c SS |
640 | ssi = nssi; |
641 | } | |
642 | ||
643 | dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */ | |
644 | } | |
645 | ||
646 | ||
647 | /* Initialize anything that needs initializing when a completely new symbol | |
648 | file is specified (not just adding some symbols from another file, e.g. a | |
649 | shared library). | |
650 | ||
651 | We reinitialize buildsym, since we may be reading stabs from an ELF file. */ | |
652 | ||
653 | static void | |
fba45db2 | 654 | elf_new_init (struct objfile *ignore) |
c906108c SS |
655 | { |
656 | stabsread_new_init (); | |
657 | buildsym_new_init (); | |
658 | } | |
659 | ||
660 | /* Perform any local cleanups required when we are done with a particular | |
661 | objfile. I.E, we are in the process of discarding all symbol information | |
662 | for an objfile, freeing up all memory held for it, and unlinking the | |
663 | objfile struct from the global list of known objfiles. */ | |
664 | ||
665 | static void | |
fba45db2 | 666 | elf_symfile_finish (struct objfile *objfile) |
c906108c | 667 | { |
c5aa993b | 668 | if (objfile->sym_stab_info != NULL) |
c906108c | 669 | { |
aac7f4ea | 670 | xmfree (objfile->md, objfile->sym_stab_info); |
c906108c SS |
671 | } |
672 | } | |
673 | ||
674 | /* ELF specific initialization routine for reading symbols. | |
675 | ||
676 | It is passed a pointer to a struct sym_fns which contains, among other | |
677 | things, the BFD for the file whose symbols are being read, and a slot for | |
678 | a pointer to "private data" which we can fill with goodies. | |
679 | ||
680 | For now at least, we have nothing in particular to do, so this function is | |
681 | just a stub. */ | |
682 | ||
683 | static void | |
fba45db2 | 684 | elf_symfile_init (struct objfile *objfile) |
c906108c SS |
685 | { |
686 | /* ELF objects may be reordered, so set OBJF_REORDERED. If we | |
687 | find this causes a significant slowdown in gdb then we could | |
688 | set it in the debug symbol readers only when necessary. */ | |
689 | objfile->flags |= OBJF_REORDERED; | |
690 | } | |
691 | ||
692 | /* When handling an ELF file that contains Sun STABS debug info, | |
693 | some of the debug info is relative to the particular chunk of the | |
694 | section that was generated in its individual .o file. E.g. | |
695 | offsets to static variables are relative to the start of the data | |
696 | segment *for that module before linking*. This information is | |
697 | painfully squirreled away in the ELF symbol table as local symbols | |
698 | with wierd names. Go get 'em when needed. */ | |
699 | ||
700 | void | |
fba45db2 | 701 | elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst) |
c906108c SS |
702 | { |
703 | char *filename = pst->filename; | |
704 | struct dbx_symfile_info *dbx = objfile->sym_stab_info; | |
705 | struct stab_section_info *maybe = dbx->stab_section_info; | |
706 | struct stab_section_info *questionable = 0; | |
707 | int i; | |
708 | char *p; | |
709 | ||
710 | /* The ELF symbol info doesn't include path names, so strip the path | |
711 | (if any) from the psymtab filename. */ | |
712 | while (0 != (p = strchr (filename, '/'))) | |
c5aa993b | 713 | filename = p + 1; |
c906108c SS |
714 | |
715 | /* FIXME: This linear search could speed up significantly | |
716 | if it was chained in the right order to match how we search it, | |
717 | and if we unchained when we found a match. */ | |
718 | for (; maybe; maybe = maybe->next) | |
719 | { | |
720 | if (filename[0] == maybe->filename[0] | |
721 | && STREQ (filename, maybe->filename)) | |
722 | { | |
723 | /* We found a match. But there might be several source files | |
724 | (from different directories) with the same name. */ | |
725 | if (0 == maybe->found) | |
726 | break; | |
c5aa993b | 727 | questionable = maybe; /* Might use it later. */ |
c906108c SS |
728 | } |
729 | } | |
730 | ||
731 | if (maybe == 0 && questionable != 0) | |
732 | { | |
23136709 KB |
733 | complaint (&symfile_complaints, |
734 | "elf/stab section information questionable for %s", filename); | |
c906108c SS |
735 | maybe = questionable; |
736 | } | |
737 | ||
738 | if (maybe) | |
739 | { | |
740 | /* Found it! Allocate a new psymtab struct, and fill it in. */ | |
741 | maybe->found++; | |
742 | pst->section_offsets = (struct section_offsets *) | |
96baa820 | 743 | obstack_alloc (&objfile->psymbol_obstack, SIZEOF_SECTION_OFFSETS); |
c906108c | 744 | for (i = 0; i < SECT_OFF_MAX; i++) |
a4c8257b | 745 | (pst->section_offsets)->offsets[i] = maybe->sections[i]; |
c906108c SS |
746 | return; |
747 | } | |
748 | ||
749 | /* We were unable to find any offsets for this file. Complain. */ | |
c5aa993b | 750 | if (dbx->stab_section_info) /* If there *is* any info, */ |
23136709 KB |
751 | complaint (&symfile_complaints, |
752 | "elf/stab section information missing for %s", filename); | |
c906108c SS |
753 | } |
754 | \f | |
755 | /* Register that we are able to handle ELF object file formats. */ | |
756 | ||
757 | static struct sym_fns elf_sym_fns = | |
758 | { | |
759 | bfd_target_elf_flavour, | |
c5aa993b JM |
760 | elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ |
761 | elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ | |
762 | elf_symfile_read, /* sym_read: read a symbol file into symtab */ | |
763 | elf_symfile_finish, /* sym_finish: finished with file, cleanup */ | |
96baa820 | 764 | default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ |
c5aa993b | 765 | NULL /* next: pointer to next struct sym_fns */ |
c906108c SS |
766 | }; |
767 | ||
768 | void | |
fba45db2 | 769 | _initialize_elfread (void) |
c906108c SS |
770 | { |
771 | add_symtab_fns (&elf_sym_fns); | |
772 | } |