Commit | Line | Data |
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c906108c | 1 | /* Read ELF (Executable and Linking Format) object files for GDB. |
1bac305b | 2 | |
6aba47ca DJ |
3 | Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, |
4 | 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
1bac305b | 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 | |
a9762ec7 | 12 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 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 | 20 | You should have received a copy of the GNU General Public License |
a9762ec7 | 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c SS |
22 | |
23 | #include "defs.h" | |
24 | #include "bfd.h" | |
25 | #include "gdb_string.h" | |
26 | #include "elf-bfd.h" | |
31d99776 DJ |
27 | #include "elf/common.h" |
28 | #include "elf/internal.h" | |
c906108c SS |
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 | { | |
c5aa993b JM |
47 | asection *stabsect; /* Section pointer for .stab section */ |
48 | asection *stabindexsect; /* Section pointer for .stab.index section */ | |
49 | asection *mdebugsect; /* Section pointer for .mdebug section */ | |
50 | }; | |
c906108c | 51 | |
12b9c64f | 52 | static void free_elfinfo (void *); |
c906108c | 53 | |
31d99776 DJ |
54 | /* Locate the segments in ABFD. */ |
55 | ||
56 | static struct symfile_segment_data * | |
57 | elf_symfile_segments (bfd *abfd) | |
58 | { | |
59 | Elf_Internal_Phdr *phdrs, **segments; | |
60 | long phdrs_size; | |
61 | int num_phdrs, num_segments, num_sections, i; | |
62 | asection *sect; | |
63 | struct symfile_segment_data *data; | |
64 | ||
65 | phdrs_size = bfd_get_elf_phdr_upper_bound (abfd); | |
66 | if (phdrs_size == -1) | |
67 | return NULL; | |
68 | ||
69 | phdrs = alloca (phdrs_size); | |
70 | num_phdrs = bfd_get_elf_phdrs (abfd, phdrs); | |
71 | if (num_phdrs == -1) | |
72 | return NULL; | |
73 | ||
74 | num_segments = 0; | |
75 | segments = alloca (sizeof (Elf_Internal_Phdr *) * num_phdrs); | |
76 | for (i = 0; i < num_phdrs; i++) | |
77 | if (phdrs[i].p_type == PT_LOAD) | |
78 | segments[num_segments++] = &phdrs[i]; | |
79 | ||
80 | if (num_segments == 0) | |
81 | return NULL; | |
82 | ||
83 | data = XZALLOC (struct symfile_segment_data); | |
84 | data->num_segments = num_segments; | |
85 | data->segment_bases = XCALLOC (num_segments, CORE_ADDR); | |
86 | data->segment_sizes = XCALLOC (num_segments, CORE_ADDR); | |
87 | ||
88 | for (i = 0; i < num_segments; i++) | |
89 | { | |
90 | data->segment_bases[i] = segments[i]->p_vaddr; | |
91 | data->segment_sizes[i] = segments[i]->p_memsz; | |
92 | } | |
93 | ||
94 | num_sections = bfd_count_sections (abfd); | |
95 | data->segment_info = XCALLOC (num_sections, int); | |
96 | ||
97 | for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next) | |
98 | { | |
99 | int j; | |
100 | CORE_ADDR vma; | |
101 | ||
102 | if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0) | |
103 | continue; | |
104 | ||
105 | vma = bfd_get_section_vma (abfd, sect); | |
106 | ||
107 | for (j = 0; j < num_segments; j++) | |
108 | if (segments[j]->p_memsz > 0 | |
109 | && vma >= segments[j]->p_vaddr | |
110 | && vma < segments[j]->p_vaddr + segments[j]->p_memsz) | |
111 | { | |
112 | data->segment_info[i] = j + 1; | |
113 | break; | |
114 | } | |
115 | ||
116 | if (bfd_get_section_size (sect) > 0 && j == num_segments) | |
117 | warning (_("Loadable segment \"%s\" outside of ELF segments"), | |
118 | bfd_section_name (abfd, sect)); | |
119 | } | |
120 | ||
121 | return data; | |
122 | } | |
123 | ||
c906108c SS |
124 | /* We are called once per section from elf_symfile_read. We |
125 | need to examine each section we are passed, check to see | |
126 | if it is something we are interested in processing, and | |
127 | if so, stash away some access information for the section. | |
128 | ||
129 | For now we recognize the dwarf debug information sections and | |
130 | line number sections from matching their section names. The | |
131 | ELF definition is no real help here since it has no direct | |
132 | knowledge of DWARF (by design, so any debugging format can be | |
133 | used). | |
134 | ||
135 | We also recognize the ".stab" sections used by the Sun compilers | |
136 | released with Solaris 2. | |
137 | ||
138 | FIXME: The section names should not be hardwired strings (what | |
139 | should they be? I don't think most object file formats have enough | |
140 | section flags to specify what kind of debug section it is | |
141 | -kingdon). */ | |
142 | ||
143 | static void | |
12b9c64f | 144 | elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip) |
c906108c | 145 | { |
52f0bd74 | 146 | struct elfinfo *ei; |
c906108c SS |
147 | |
148 | ei = (struct elfinfo *) eip; | |
7ce59000 | 149 | if (strcmp (sectp->name, ".stab") == 0) |
c906108c | 150 | { |
c5aa993b | 151 | ei->stabsect = sectp; |
c906108c | 152 | } |
6314a349 | 153 | else if (strcmp (sectp->name, ".stab.index") == 0) |
c906108c | 154 | { |
c5aa993b | 155 | ei->stabindexsect = sectp; |
c906108c | 156 | } |
6314a349 | 157 | else if (strcmp (sectp->name, ".mdebug") == 0) |
c906108c | 158 | { |
c5aa993b | 159 | ei->mdebugsect = sectp; |
c906108c SS |
160 | } |
161 | } | |
162 | ||
c906108c | 163 | static struct minimal_symbol * |
f594e5e9 MC |
164 | record_minimal_symbol (char *name, CORE_ADDR address, |
165 | enum minimal_symbol_type ms_type, | |
166 | asection *bfd_section, struct objfile *objfile) | |
c906108c | 167 | { |
bbeae047 | 168 | if (ms_type == mst_text || ms_type == mst_file_text) |
260edbc2 | 169 | address = gdbarch_smash_text_address (current_gdbarch, address); |
c906108c SS |
170 | |
171 | return prim_record_minimal_symbol_and_info | |
f594e5e9 | 172 | (name, address, ms_type, NULL, bfd_section->index, bfd_section, objfile); |
c906108c SS |
173 | } |
174 | ||
175 | /* | |
176 | ||
c5aa993b | 177 | LOCAL FUNCTION |
c906108c | 178 | |
c5aa993b | 179 | elf_symtab_read -- read the symbol table of an ELF file |
c906108c | 180 | |
c5aa993b | 181 | SYNOPSIS |
c906108c | 182 | |
6f610d07 | 183 | void elf_symtab_read (struct objfile *objfile, int type, |
62553543 | 184 | long number_of_symbols, asymbol **symbol_table) |
c906108c | 185 | |
c5aa993b | 186 | DESCRIPTION |
c906108c | 187 | |
62553543 | 188 | Given an objfile, a symbol table, and a flag indicating whether the |
6f610d07 UW |
189 | symbol table contains regular, dynamic, or synthetic symbols, add all |
190 | the global function and data symbols to the minimal symbol table. | |
c906108c | 191 | |
c5aa993b JM |
192 | In stabs-in-ELF, as implemented by Sun, there are some local symbols |
193 | defined in the ELF symbol table, which can be used to locate | |
194 | the beginnings of sections from each ".o" file that was linked to | |
195 | form the executable objfile. We gather any such info and record it | |
196 | in data structures hung off the objfile's private data. | |
c906108c | 197 | |
c5aa993b | 198 | */ |
c906108c | 199 | |
6f610d07 UW |
200 | #define ST_REGULAR 0 |
201 | #define ST_DYNAMIC 1 | |
202 | #define ST_SYNTHETIC 2 | |
203 | ||
c906108c | 204 | static void |
6f610d07 | 205 | elf_symtab_read (struct objfile *objfile, int type, |
62553543 | 206 | long number_of_symbols, asymbol **symbol_table) |
c906108c SS |
207 | { |
208 | long storage_needed; | |
209 | asymbol *sym; | |
c906108c | 210 | long i; |
c906108c | 211 | CORE_ADDR symaddr; |
d4f3574e | 212 | CORE_ADDR offset; |
c906108c SS |
213 | enum minimal_symbol_type ms_type; |
214 | /* If sectinfo is nonNULL, it contains section info that should end up | |
215 | filed in the objfile. */ | |
216 | struct stab_section_info *sectinfo = NULL; | |
217 | /* If filesym is nonzero, it points to a file symbol, but we haven't | |
218 | seen any section info for it yet. */ | |
219 | asymbol *filesym = 0; | |
4a146b47 EZ |
220 | /* Name of filesym, as saved on the objfile_obstack. */ |
221 | char *filesymname = obsavestring ("", 0, &objfile->objfile_obstack); | |
0a6ddd08 | 222 | struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info; |
d4f3574e | 223 | int stripped = (bfd_get_symcount (objfile->obfd) == 0); |
c5aa993b | 224 | |
0cc7b392 | 225 | for (i = 0; i < number_of_symbols; i++) |
c906108c | 226 | { |
0cc7b392 DJ |
227 | sym = symbol_table[i]; |
228 | if (sym->name == NULL || *sym->name == '\0') | |
c906108c | 229 | { |
0cc7b392 DJ |
230 | /* Skip names that don't exist (shouldn't happen), or names |
231 | that are null strings (may happen). */ | |
232 | continue; | |
233 | } | |
c906108c | 234 | |
74763737 DJ |
235 | /* Skip "special" symbols, e.g. ARM mapping symbols. These are |
236 | symbols which do not correspond to objects in the symbol table, | |
237 | but have some other target-specific meaning. */ | |
238 | if (bfd_is_target_special_symbol (objfile->obfd, sym)) | |
239 | continue; | |
240 | ||
0cc7b392 | 241 | offset = ANOFFSET (objfile->section_offsets, sym->section->index); |
6f610d07 | 242 | if (type == ST_DYNAMIC |
0cc7b392 DJ |
243 | && sym->section == &bfd_und_section |
244 | && (sym->flags & BSF_FUNCTION)) | |
245 | { | |
246 | struct minimal_symbol *msym; | |
02c75f72 UW |
247 | bfd *abfd = objfile->obfd; |
248 | asection *sect; | |
0cc7b392 DJ |
249 | |
250 | /* Symbol is a reference to a function defined in | |
251 | a shared library. | |
252 | If its value is non zero then it is usually the address | |
253 | of the corresponding entry in the procedure linkage table, | |
254 | plus the desired section offset. | |
255 | If its value is zero then the dynamic linker has to resolve | |
256 | the symbol. We are unable to find any meaningful address | |
257 | for this symbol in the executable file, so we skip it. */ | |
258 | symaddr = sym->value; | |
259 | if (symaddr == 0) | |
260 | continue; | |
02c75f72 UW |
261 | |
262 | /* sym->section is the undefined section. However, we want to | |
263 | record the section where the PLT stub resides with the | |
264 | minimal symbol. Search the section table for the one that | |
265 | covers the stub's address. */ | |
266 | for (sect = abfd->sections; sect != NULL; sect = sect->next) | |
267 | { | |
268 | if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0) | |
269 | continue; | |
270 | ||
271 | if (symaddr >= bfd_get_section_vma (abfd, sect) | |
272 | && symaddr < bfd_get_section_vma (abfd, sect) | |
273 | + bfd_get_section_size (sect)) | |
274 | break; | |
275 | } | |
276 | if (!sect) | |
277 | continue; | |
278 | ||
279 | symaddr += ANOFFSET (objfile->section_offsets, sect->index); | |
280 | ||
0cc7b392 | 281 | msym = record_minimal_symbol |
02c75f72 | 282 | ((char *) sym->name, symaddr, mst_solib_trampoline, sect, objfile); |
0cc7b392 DJ |
283 | if (msym != NULL) |
284 | msym->filename = filesymname; | |
0cc7b392 DJ |
285 | continue; |
286 | } | |
c906108c | 287 | |
0cc7b392 DJ |
288 | /* If it is a nonstripped executable, do not enter dynamic |
289 | symbols, as the dynamic symbol table is usually a subset | |
290 | of the main symbol table. */ | |
6f610d07 | 291 | if (type == ST_DYNAMIC && !stripped) |
0cc7b392 DJ |
292 | continue; |
293 | if (sym->flags & BSF_FILE) | |
294 | { | |
295 | /* STT_FILE debugging symbol that helps stabs-in-elf debugging. | |
296 | Chain any old one onto the objfile; remember new sym. */ | |
297 | if (sectinfo != NULL) | |
c906108c | 298 | { |
0cc7b392 DJ |
299 | sectinfo->next = dbx->stab_section_info; |
300 | dbx->stab_section_info = sectinfo; | |
301 | sectinfo = NULL; | |
302 | } | |
303 | filesym = sym; | |
0cc7b392 DJ |
304 | filesymname = |
305 | obsavestring ((char *) filesym->name, strlen (filesym->name), | |
306 | &objfile->objfile_obstack); | |
0cc7b392 DJ |
307 | } |
308 | else if (sym->flags & BSF_SECTION_SYM) | |
309 | continue; | |
310 | else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK)) | |
311 | { | |
312 | struct minimal_symbol *msym; | |
313 | ||
314 | /* Select global/local/weak symbols. Note that bfd puts abs | |
315 | symbols in their own section, so all symbols we are | |
316 | interested in will have a section. */ | |
317 | /* Bfd symbols are section relative. */ | |
318 | symaddr = sym->value + sym->section->vma; | |
319 | /* Relocate all non-absolute symbols by the section offset. */ | |
320 | if (sym->section != &bfd_abs_section) | |
321 | { | |
322 | symaddr += offset; | |
c906108c | 323 | } |
0cc7b392 DJ |
324 | /* For non-absolute symbols, use the type of the section |
325 | they are relative to, to intuit text/data. Bfd provides | |
326 | no way of figuring this out for absolute symbols. */ | |
327 | if (sym->section == &bfd_abs_section) | |
c906108c | 328 | { |
0cc7b392 DJ |
329 | /* This is a hack to get the minimal symbol type |
330 | right for Irix 5, which has absolute addresses | |
6f610d07 UW |
331 | with special section indices for dynamic symbols. |
332 | ||
333 | NOTE: uweigand-20071112: Synthetic symbols do not | |
334 | have an ELF-private part, so do not touch those. */ | |
335 | unsigned short shndx = type == ST_SYNTHETIC ? 0 : | |
0cc7b392 DJ |
336 | ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx; |
337 | ||
338 | switch (shndx) | |
c906108c | 339 | { |
0cc7b392 DJ |
340 | case SHN_MIPS_TEXT: |
341 | ms_type = mst_text; | |
342 | break; | |
343 | case SHN_MIPS_DATA: | |
344 | ms_type = mst_data; | |
345 | break; | |
346 | case SHN_MIPS_ACOMMON: | |
347 | ms_type = mst_bss; | |
348 | break; | |
349 | default: | |
350 | ms_type = mst_abs; | |
351 | } | |
352 | ||
353 | /* If it is an Irix dynamic symbol, skip section name | |
354 | symbols, relocate all others by section offset. */ | |
355 | if (ms_type != mst_abs) | |
356 | { | |
357 | if (sym->name[0] == '.') | |
358 | continue; | |
d4f3574e | 359 | symaddr += offset; |
c906108c | 360 | } |
0cc7b392 DJ |
361 | } |
362 | else if (sym->section->flags & SEC_CODE) | |
363 | { | |
08232497 | 364 | if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) |
c906108c | 365 | { |
0cc7b392 DJ |
366 | ms_type = mst_text; |
367 | } | |
368 | else if ((sym->name[0] == '.' && sym->name[1] == 'L') | |
369 | || ((sym->flags & BSF_LOCAL) | |
370 | && sym->name[0] == '$' | |
371 | && sym->name[1] == 'L')) | |
372 | /* Looks like a compiler-generated label. Skip | |
373 | it. The assembler should be skipping these (to | |
374 | keep executables small), but apparently with | |
375 | gcc on the (deleted) delta m88k SVR4, it loses. | |
376 | So to have us check too should be harmless (but | |
377 | I encourage people to fix this in the assembler | |
378 | instead of adding checks here). */ | |
379 | continue; | |
380 | else | |
381 | { | |
382 | ms_type = mst_file_text; | |
c906108c | 383 | } |
0cc7b392 DJ |
384 | } |
385 | else if (sym->section->flags & SEC_ALLOC) | |
386 | { | |
387 | if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) | |
c906108c | 388 | { |
0cc7b392 | 389 | if (sym->section->flags & SEC_LOAD) |
c906108c | 390 | { |
0cc7b392 | 391 | ms_type = mst_data; |
c906108c | 392 | } |
c906108c SS |
393 | else |
394 | { | |
0cc7b392 | 395 | ms_type = mst_bss; |
c906108c SS |
396 | } |
397 | } | |
0cc7b392 | 398 | else if (sym->flags & BSF_LOCAL) |
c906108c | 399 | { |
0cc7b392 DJ |
400 | /* Named Local variable in a Data section. |
401 | Check its name for stabs-in-elf. */ | |
402 | int special_local_sect; | |
403 | if (strcmp ("Bbss.bss", sym->name) == 0) | |
404 | special_local_sect = SECT_OFF_BSS (objfile); | |
405 | else if (strcmp ("Ddata.data", sym->name) == 0) | |
406 | special_local_sect = SECT_OFF_DATA (objfile); | |
407 | else if (strcmp ("Drodata.rodata", sym->name) == 0) | |
408 | special_local_sect = SECT_OFF_RODATA (objfile); | |
409 | else | |
410 | special_local_sect = -1; | |
411 | if (special_local_sect >= 0) | |
c906108c | 412 | { |
0cc7b392 DJ |
413 | /* Found a special local symbol. Allocate a |
414 | sectinfo, if needed, and fill it in. */ | |
415 | if (sectinfo == NULL) | |
c906108c | 416 | { |
0cc7b392 DJ |
417 | int max_index; |
418 | size_t size; | |
419 | ||
420 | max_index | |
421 | = max (SECT_OFF_BSS (objfile), | |
422 | max (SECT_OFF_DATA (objfile), | |
423 | SECT_OFF_RODATA (objfile))); | |
424 | ||
425 | /* max_index is the largest index we'll | |
426 | use into this array, so we must | |
427 | allocate max_index+1 elements for it. | |
428 | However, 'struct stab_section_info' | |
429 | already includes one element, so we | |
430 | need to allocate max_index aadditional | |
431 | elements. */ | |
432 | size = (sizeof (struct stab_section_info) | |
433 | + (sizeof (CORE_ADDR) | |
434 | * max_index)); | |
435 | sectinfo = (struct stab_section_info *) | |
436 | xmalloc (size); | |
437 | memset (sectinfo, 0, size); | |
438 | sectinfo->num_sections = max_index; | |
439 | if (filesym == NULL) | |
c906108c | 440 | { |
0cc7b392 DJ |
441 | complaint (&symfile_complaints, |
442 | _("elf/stab section information %s without a preceding file symbol"), | |
443 | sym->name); | |
444 | } | |
445 | else | |
446 | { | |
447 | sectinfo->filename = | |
448 | (char *) filesym->name; | |
c906108c | 449 | } |
c906108c | 450 | } |
0cc7b392 DJ |
451 | if (sectinfo->sections[special_local_sect] != 0) |
452 | complaint (&symfile_complaints, | |
453 | _("duplicated elf/stab section information for %s"), | |
454 | sectinfo->filename); | |
455 | /* BFD symbols are section relative. */ | |
456 | symaddr = sym->value + sym->section->vma; | |
457 | /* Relocate non-absolute symbols by the | |
458 | section offset. */ | |
459 | if (sym->section != &bfd_abs_section) | |
460 | symaddr += offset; | |
461 | sectinfo->sections[special_local_sect] = symaddr; | |
462 | /* The special local symbols don't go in the | |
463 | minimal symbol table, so ignore this one. */ | |
464 | continue; | |
465 | } | |
466 | /* Not a special stabs-in-elf symbol, do regular | |
467 | symbol processing. */ | |
468 | if (sym->section->flags & SEC_LOAD) | |
469 | { | |
470 | ms_type = mst_file_data; | |
c906108c SS |
471 | } |
472 | else | |
473 | { | |
0cc7b392 | 474 | ms_type = mst_file_bss; |
c906108c SS |
475 | } |
476 | } | |
477 | else | |
478 | { | |
0cc7b392 | 479 | ms_type = mst_unknown; |
c906108c | 480 | } |
0cc7b392 DJ |
481 | } |
482 | else | |
483 | { | |
484 | /* FIXME: Solaris2 shared libraries include lots of | |
485 | odd "absolute" and "undefined" symbols, that play | |
486 | hob with actions like finding what function the PC | |
487 | is in. Ignore them if they aren't text, data, or bss. */ | |
488 | /* ms_type = mst_unknown; */ | |
489 | continue; /* Skip this symbol. */ | |
490 | } | |
491 | msym = record_minimal_symbol | |
492 | ((char *) sym->name, symaddr, | |
493 | ms_type, sym->section, objfile); | |
6f610d07 | 494 | |
0cc7b392 DJ |
495 | if (msym) |
496 | { | |
497 | /* Pass symbol size field in via BFD. FIXME!!! */ | |
6f610d07 UW |
498 | elf_symbol_type *elf_sym; |
499 | ||
500 | /* NOTE: uweigand-20071112: A synthetic symbol does not have an | |
501 | ELF-private part. However, in some cases (e.g. synthetic | |
502 | 'dot' symbols on ppc64) the udata.p entry is set to point back | |
503 | to the original ELF symbol it was derived from. Get the size | |
504 | from that symbol. */ | |
505 | if (type != ST_SYNTHETIC) | |
506 | elf_sym = (elf_symbol_type *) sym; | |
507 | else | |
508 | elf_sym = (elf_symbol_type *) sym->udata.p; | |
509 | ||
510 | if (elf_sym) | |
511 | MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size; | |
0cc7b392 | 512 | } |
0cc7b392 DJ |
513 | if (msym != NULL) |
514 | msym->filename = filesymname; | |
95f1da47 | 515 | gdbarch_elf_make_msymbol_special (current_gdbarch, sym, msym); |
c906108c | 516 | } |
c906108c SS |
517 | } |
518 | } | |
519 | ||
520 | /* Scan and build partial symbols for a symbol file. | |
521 | We have been initialized by a call to elf_symfile_init, which | |
522 | currently does nothing. | |
523 | ||
524 | SECTION_OFFSETS is a set of offsets to apply to relocate the symbols | |
525 | in each section. We simplify it down to a single offset for all | |
526 | symbols. FIXME. | |
527 | ||
528 | MAINLINE is true if we are reading the main symbol | |
529 | table (as opposed to a shared lib or dynamically loaded file). | |
530 | ||
531 | This function only does the minimum work necessary for letting the | |
532 | user "name" things symbolically; it does not read the entire symtab. | |
533 | Instead, it reads the external and static symbols and puts them in partial | |
534 | symbol tables. When more extensive information is requested of a | |
535 | file, the corresponding partial symbol table is mutated into a full | |
536 | fledged symbol table by going back and reading the symbols | |
537 | for real. | |
538 | ||
539 | We look for sections with specific names, to tell us what debug | |
540 | format to look for: FIXME!!! | |
541 | ||
c906108c SS |
542 | elfstab_build_psymtabs() handles STABS symbols; |
543 | mdebug_build_psymtabs() handles ECOFF debugging information. | |
544 | ||
545 | Note that ELF files have a "minimal" symbol table, which looks a lot | |
546 | like a COFF symbol table, but has only the minimal information necessary | |
547 | for linking. We process this also, and use the information to | |
548 | build gdb's minimal symbol table. This gives us some minimal debugging | |
549 | capability even for files compiled without -g. */ | |
550 | ||
551 | static void | |
fba45db2 | 552 | elf_symfile_read (struct objfile *objfile, int mainline) |
c906108c SS |
553 | { |
554 | bfd *abfd = objfile->obfd; | |
555 | struct elfinfo ei; | |
556 | struct cleanup *back_to; | |
557 | CORE_ADDR offset; | |
62553543 EZ |
558 | long symcount = 0, dynsymcount = 0, synthcount, storage_needed; |
559 | asymbol **symbol_table = NULL, **dyn_symbol_table = NULL; | |
560 | asymbol *synthsyms; | |
c906108c SS |
561 | |
562 | init_minimal_symbol_collection (); | |
56e290f4 | 563 | back_to = make_cleanup_discard_minimal_symbols (); |
c906108c SS |
564 | |
565 | memset ((char *) &ei, 0, sizeof (ei)); | |
566 | ||
567 | /* Allocate struct to keep track of the symfile */ | |
0a6ddd08 | 568 | objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *) |
7936743b | 569 | xmalloc (sizeof (struct dbx_symfile_info)); |
0a6ddd08 | 570 | memset ((char *) objfile->deprecated_sym_stab_info, 0, sizeof (struct dbx_symfile_info)); |
12b9c64f | 571 | make_cleanup (free_elfinfo, (void *) objfile); |
c906108c SS |
572 | |
573 | /* Process the normal ELF symbol table first. This may write some | |
0a6ddd08 | 574 | chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info, |
c906108c SS |
575 | which can later be used by elfstab_offset_sections. */ |
576 | ||
62553543 EZ |
577 | storage_needed = bfd_get_symtab_upper_bound (objfile->obfd); |
578 | if (storage_needed < 0) | |
579 | error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), | |
580 | bfd_errmsg (bfd_get_error ())); | |
581 | ||
582 | if (storage_needed > 0) | |
583 | { | |
584 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
585 | make_cleanup (xfree, symbol_table); | |
586 | symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table); | |
587 | ||
588 | if (symcount < 0) | |
589 | error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), | |
590 | bfd_errmsg (bfd_get_error ())); | |
591 | ||
6f610d07 | 592 | elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table); |
62553543 | 593 | } |
c906108c SS |
594 | |
595 | /* Add the dynamic symbols. */ | |
596 | ||
62553543 EZ |
597 | storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd); |
598 | ||
599 | if (storage_needed > 0) | |
600 | { | |
601 | dyn_symbol_table = (asymbol **) xmalloc (storage_needed); | |
602 | make_cleanup (xfree, dyn_symbol_table); | |
603 | dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd, | |
604 | dyn_symbol_table); | |
605 | ||
606 | if (dynsymcount < 0) | |
607 | error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), | |
608 | bfd_errmsg (bfd_get_error ())); | |
609 | ||
6f610d07 | 610 | elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table); |
62553543 EZ |
611 | } |
612 | ||
613 | /* Add synthetic symbols - for instance, names for any PLT entries. */ | |
614 | ||
615 | synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table, | |
616 | dynsymcount, dyn_symbol_table, | |
617 | &synthsyms); | |
618 | if (synthcount > 0) | |
619 | { | |
620 | asymbol **synth_symbol_table; | |
621 | long i; | |
622 | ||
623 | make_cleanup (xfree, synthsyms); | |
624 | synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount); | |
625 | for (i = 0; i < synthcount; i++) | |
9f20e3da | 626 | synth_symbol_table[i] = synthsyms + i; |
62553543 | 627 | make_cleanup (xfree, synth_symbol_table); |
6f610d07 | 628 | elf_symtab_read (objfile, ST_SYNTHETIC, synthcount, synth_symbol_table); |
62553543 | 629 | } |
c906108c | 630 | |
7134143f DJ |
631 | /* Install any minimal symbols that have been collected as the current |
632 | minimal symbols for this objfile. The debug readers below this point | |
633 | should not generate new minimal symbols; if they do it's their | |
634 | responsibility to install them. "mdebug" appears to be the only one | |
635 | which will do this. */ | |
636 | ||
637 | install_minimal_symbols (objfile); | |
638 | do_cleanups (back_to); | |
639 | ||
c906108c SS |
640 | /* Now process debugging information, which is contained in |
641 | special ELF sections. */ | |
642 | ||
643 | /* If we are reinitializing, or if we have never loaded syms yet, | |
644 | set table to empty. MAINLINE is cleared so that *_read_psymtab | |
645 | functions do not all also re-initialize the psymbol table. */ | |
646 | if (mainline) | |
647 | { | |
648 | init_psymbol_list (objfile, 0); | |
649 | mainline = 0; | |
650 | } | |
651 | ||
652 | /* We first have to find them... */ | |
12b9c64f | 653 | bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei); |
c906108c SS |
654 | |
655 | /* ELF debugging information is inserted into the psymtab in the | |
656 | order of least informative first - most informative last. Since | |
657 | the psymtab table is searched `most recent insertion first' this | |
658 | increases the probability that more detailed debug information | |
659 | for a section is found. | |
660 | ||
661 | For instance, an object file might contain both .mdebug (XCOFF) | |
662 | and .debug_info (DWARF2) sections then .mdebug is inserted first | |
663 | (searched last) and DWARF2 is inserted last (searched first). If | |
664 | we don't do this then the XCOFF info is found first - for code in | |
665 | an included file XCOFF info is useless. */ | |
666 | ||
667 | if (ei.mdebugsect) | |
668 | { | |
669 | const struct ecoff_debug_swap *swap; | |
670 | ||
671 | /* .mdebug section, presumably holding ECOFF debugging | |
c5aa993b | 672 | information. */ |
c906108c SS |
673 | swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap; |
674 | if (swap) | |
d4f3574e | 675 | elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect); |
c906108c SS |
676 | } |
677 | if (ei.stabsect) | |
678 | { | |
679 | asection *str_sect; | |
680 | ||
681 | /* Stab sections have an associated string table that looks like | |
c5aa993b | 682 | a separate section. */ |
c906108c SS |
683 | str_sect = bfd_get_section_by_name (abfd, ".stabstr"); |
684 | ||
685 | /* FIXME should probably warn about a stab section without a stabstr. */ | |
686 | if (str_sect) | |
687 | elfstab_build_psymtabs (objfile, | |
c906108c | 688 | mainline, |
086df311 | 689 | ei.stabsect, |
c906108c SS |
690 | str_sect->filepos, |
691 | bfd_section_size (abfd, str_sect)); | |
692 | } | |
c5edf76a | 693 | if (dwarf2_has_info (objfile)) |
c906108c SS |
694 | { |
695 | /* DWARF 2 sections */ | |
d4f3574e | 696 | dwarf2_build_psymtabs (objfile, mainline); |
c906108c | 697 | } |
c906108c | 698 | |
625b0b97 AC |
699 | /* FIXME: kettenis/20030504: This still needs to be integrated with |
700 | dwarf2read.c in a better way. */ | |
701 | dwarf2_build_frame_info (objfile); | |
c906108c SS |
702 | } |
703 | ||
0a6ddd08 AC |
704 | /* This cleans up the objfile's deprecated_sym_stab_info pointer, and |
705 | the chain of stab_section_info's, that might be dangling from | |
706 | it. */ | |
c906108c SS |
707 | |
708 | static void | |
12b9c64f | 709 | free_elfinfo (void *objp) |
c906108c | 710 | { |
c5aa993b | 711 | struct objfile *objfile = (struct objfile *) objp; |
0a6ddd08 | 712 | struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info; |
c906108c SS |
713 | struct stab_section_info *ssi, *nssi; |
714 | ||
715 | ssi = dbxinfo->stab_section_info; | |
716 | while (ssi) | |
717 | { | |
718 | nssi = ssi->next; | |
2dc74dc1 | 719 | xfree (ssi); |
c906108c SS |
720 | ssi = nssi; |
721 | } | |
722 | ||
723 | dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */ | |
724 | } | |
725 | ||
726 | ||
727 | /* Initialize anything that needs initializing when a completely new symbol | |
728 | file is specified (not just adding some symbols from another file, e.g. a | |
729 | shared library). | |
730 | ||
731 | We reinitialize buildsym, since we may be reading stabs from an ELF file. */ | |
732 | ||
733 | static void | |
fba45db2 | 734 | elf_new_init (struct objfile *ignore) |
c906108c SS |
735 | { |
736 | stabsread_new_init (); | |
737 | buildsym_new_init (); | |
738 | } | |
739 | ||
740 | /* Perform any local cleanups required when we are done with a particular | |
741 | objfile. I.E, we are in the process of discarding all symbol information | |
742 | for an objfile, freeing up all memory held for it, and unlinking the | |
743 | objfile struct from the global list of known objfiles. */ | |
744 | ||
745 | static void | |
fba45db2 | 746 | elf_symfile_finish (struct objfile *objfile) |
c906108c | 747 | { |
0a6ddd08 | 748 | if (objfile->deprecated_sym_stab_info != NULL) |
c906108c | 749 | { |
0a6ddd08 | 750 | xfree (objfile->deprecated_sym_stab_info); |
c906108c | 751 | } |
fe3e1990 DJ |
752 | |
753 | dwarf2_free_objfile (objfile); | |
c906108c SS |
754 | } |
755 | ||
756 | /* ELF specific initialization routine for reading symbols. | |
757 | ||
758 | It is passed a pointer to a struct sym_fns which contains, among other | |
759 | things, the BFD for the file whose symbols are being read, and a slot for | |
760 | a pointer to "private data" which we can fill with goodies. | |
761 | ||
762 | For now at least, we have nothing in particular to do, so this function is | |
763 | just a stub. */ | |
764 | ||
765 | static void | |
fba45db2 | 766 | elf_symfile_init (struct objfile *objfile) |
c906108c SS |
767 | { |
768 | /* ELF objects may be reordered, so set OBJF_REORDERED. If we | |
769 | find this causes a significant slowdown in gdb then we could | |
770 | set it in the debug symbol readers only when necessary. */ | |
771 | objfile->flags |= OBJF_REORDERED; | |
772 | } | |
773 | ||
774 | /* When handling an ELF file that contains Sun STABS debug info, | |
775 | some of the debug info is relative to the particular chunk of the | |
776 | section that was generated in its individual .o file. E.g. | |
777 | offsets to static variables are relative to the start of the data | |
778 | segment *for that module before linking*. This information is | |
779 | painfully squirreled away in the ELF symbol table as local symbols | |
780 | with wierd names. Go get 'em when needed. */ | |
781 | ||
782 | void | |
fba45db2 | 783 | elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst) |
c906108c SS |
784 | { |
785 | char *filename = pst->filename; | |
0a6ddd08 | 786 | struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info; |
c906108c SS |
787 | struct stab_section_info *maybe = dbx->stab_section_info; |
788 | struct stab_section_info *questionable = 0; | |
789 | int i; | |
790 | char *p; | |
791 | ||
792 | /* The ELF symbol info doesn't include path names, so strip the path | |
793 | (if any) from the psymtab filename. */ | |
794 | while (0 != (p = strchr (filename, '/'))) | |
c5aa993b | 795 | filename = p + 1; |
c906108c SS |
796 | |
797 | /* FIXME: This linear search could speed up significantly | |
798 | if it was chained in the right order to match how we search it, | |
799 | and if we unchained when we found a match. */ | |
800 | for (; maybe; maybe = maybe->next) | |
801 | { | |
802 | if (filename[0] == maybe->filename[0] | |
6314a349 | 803 | && strcmp (filename, maybe->filename) == 0) |
c906108c SS |
804 | { |
805 | /* We found a match. But there might be several source files | |
806 | (from different directories) with the same name. */ | |
807 | if (0 == maybe->found) | |
808 | break; | |
c5aa993b | 809 | questionable = maybe; /* Might use it later. */ |
c906108c SS |
810 | } |
811 | } | |
812 | ||
813 | if (maybe == 0 && questionable != 0) | |
814 | { | |
23136709 | 815 | complaint (&symfile_complaints, |
e2e0b3e5 | 816 | _("elf/stab section information questionable for %s"), filename); |
c906108c SS |
817 | maybe = questionable; |
818 | } | |
819 | ||
820 | if (maybe) | |
821 | { | |
822 | /* Found it! Allocate a new psymtab struct, and fill it in. */ | |
823 | maybe->found++; | |
824 | pst->section_offsets = (struct section_offsets *) | |
8b92e4d5 | 825 | obstack_alloc (&objfile->objfile_obstack, |
a39a16c4 MM |
826 | SIZEOF_N_SECTION_OFFSETS (objfile->num_sections)); |
827 | for (i = 0; i < maybe->num_sections; i++) | |
a4c8257b | 828 | (pst->section_offsets)->offsets[i] = maybe->sections[i]; |
c906108c SS |
829 | return; |
830 | } | |
831 | ||
832 | /* We were unable to find any offsets for this file. Complain. */ | |
c5aa993b | 833 | if (dbx->stab_section_info) /* If there *is* any info, */ |
23136709 | 834 | complaint (&symfile_complaints, |
e2e0b3e5 | 835 | _("elf/stab section information missing for %s"), filename); |
c906108c SS |
836 | } |
837 | \f | |
838 | /* Register that we are able to handle ELF object file formats. */ | |
839 | ||
840 | static struct sym_fns elf_sym_fns = | |
841 | { | |
842 | bfd_target_elf_flavour, | |
c5aa993b JM |
843 | elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ |
844 | elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ | |
845 | elf_symfile_read, /* sym_read: read a symbol file into symtab */ | |
846 | elf_symfile_finish, /* sym_finish: finished with file, cleanup */ | |
96baa820 | 847 | default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ |
31d99776 DJ |
848 | elf_symfile_segments, /* sym_segments: Get segment information from |
849 | a file. */ | |
c295b2e5 | 850 | NULL, /* sym_read_linetable */ |
c5aa993b | 851 | NULL /* next: pointer to next struct sym_fns */ |
c906108c SS |
852 | }; |
853 | ||
854 | void | |
fba45db2 | 855 | _initialize_elfread (void) |
c906108c SS |
856 | { |
857 | add_symtab_fns (&elf_sym_fns); | |
858 | } |