gdb: GC old versions
[dragonfly.git] / contrib / gdb-7 / gdb / elfread.c
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1/* Read ELF (Executable and Linking Format) object files for GDB.
2
3 Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 Free Software Foundation, Inc.
6
7 Written by Fred Fish at Cygnus Support.
8
9 This file is part of GDB.
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23
24#include "defs.h"
25#include "bfd.h"
26#include "gdb_string.h"
27#include "elf-bfd.h"
28#include "elf/common.h"
29#include "elf/internal.h"
30#include "elf/mips.h"
31#include "symtab.h"
32#include "symfile.h"
33#include "objfiles.h"
34#include "buildsym.h"
35#include "stabsread.h"
36#include "gdb-stabs.h"
37#include "complaints.h"
38#include "demangle.h"
39
40extern void _initialize_elfread (void);
41
42/* The struct elfinfo is available only during ELF symbol table and
43 psymtab reading. It is destroyed at the completion of psymtab-reading.
44 It's local to elf_symfile_read. */
45
46struct elfinfo
47 {
48 asection *stabsect; /* Section pointer for .stab section */
49 asection *stabindexsect; /* Section pointer for .stab.index section */
50 asection *mdebugsect; /* Section pointer for .mdebug section */
51 };
52
53static void free_elfinfo (void *);
54
55/* Locate the segments in ABFD. */
56
57static struct symfile_segment_data *
58elf_symfile_segments (bfd *abfd)
59{
60 Elf_Internal_Phdr *phdrs, **segments;
61 long phdrs_size;
62 int num_phdrs, num_segments, num_sections, i;
63 asection *sect;
64 struct symfile_segment_data *data;
65
66 phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
67 if (phdrs_size == -1)
68 return NULL;
69
70 phdrs = alloca (phdrs_size);
71 num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
72 if (num_phdrs == -1)
73 return NULL;
74
75 num_segments = 0;
76 segments = alloca (sizeof (Elf_Internal_Phdr *) * num_phdrs);
77 for (i = 0; i < num_phdrs; i++)
78 if (phdrs[i].p_type == PT_LOAD)
79 segments[num_segments++] = &phdrs[i];
80
81 if (num_segments == 0)
82 return NULL;
83
84 data = XZALLOC (struct symfile_segment_data);
85 data->num_segments = num_segments;
86 data->segment_bases = XCALLOC (num_segments, CORE_ADDR);
87 data->segment_sizes = XCALLOC (num_segments, CORE_ADDR);
88
89 for (i = 0; i < num_segments; i++)
90 {
91 data->segment_bases[i] = segments[i]->p_vaddr;
92 data->segment_sizes[i] = segments[i]->p_memsz;
93 }
94
95 num_sections = bfd_count_sections (abfd);
96 data->segment_info = XCALLOC (num_sections, int);
97
98 for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next)
99 {
100 int j;
101 CORE_ADDR vma;
102
103 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
104 continue;
105
106 vma = bfd_get_section_vma (abfd, sect);
107
108 for (j = 0; j < num_segments; j++)
109 if (segments[j]->p_memsz > 0
110 && vma >= segments[j]->p_vaddr
111 && (vma - segments[j]->p_vaddr) < segments[j]->p_memsz)
112 {
113 data->segment_info[i] = j + 1;
114 break;
115 }
116
117 if (bfd_get_section_size (sect) > 0 && j == num_segments)
118 warning (_("Loadable segment \"%s\" outside of ELF segments"),
119 bfd_section_name (abfd, sect));
120 }
121
122 return data;
123}
124
125/* We are called once per section from elf_symfile_read. We
126 need to examine each section we are passed, check to see
127 if it is something we are interested in processing, and
128 if so, stash away some access information for the section.
129
130 For now we recognize the dwarf debug information sections and
131 line number sections from matching their section names. The
132 ELF definition is no real help here since it has no direct
133 knowledge of DWARF (by design, so any debugging format can be
134 used).
135
136 We also recognize the ".stab" sections used by the Sun compilers
137 released with Solaris 2.
138
139 FIXME: The section names should not be hardwired strings (what
140 should they be? I don't think most object file formats have enough
141 section flags to specify what kind of debug section it is
142 -kingdon). */
143
144static void
145elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip)
146{
147 struct elfinfo *ei;
148
149 ei = (struct elfinfo *) eip;
150 if (strcmp (sectp->name, ".stab") == 0)
151 {
152 ei->stabsect = sectp;
153 }
154 else if (strcmp (sectp->name, ".stab.index") == 0)
155 {
156 ei->stabindexsect = sectp;
157 }
158 else if (strcmp (sectp->name, ".mdebug") == 0)
159 {
160 ei->mdebugsect = sectp;
161 }
162}
163
164static struct minimal_symbol *
165record_minimal_symbol (char *name, CORE_ADDR address,
166 enum minimal_symbol_type ms_type,
167 asection *bfd_section, struct objfile *objfile)
168{
169 struct gdbarch *gdbarch = get_objfile_arch (objfile);
170
171 if (ms_type == mst_text || ms_type == mst_file_text)
172 address = gdbarch_smash_text_address (gdbarch, address);
173
174 return prim_record_minimal_symbol_and_info
175 (name, address, ms_type, bfd_section->index, bfd_section, objfile);
176}
177
178/*
179
180 LOCAL FUNCTION
181
182 elf_symtab_read -- read the symbol table of an ELF file
183
184 SYNOPSIS
185
186 void elf_symtab_read (struct objfile *objfile, int type,
187 long number_of_symbols, asymbol **symbol_table)
188
189 DESCRIPTION
190
191 Given an objfile, a symbol table, and a flag indicating whether the
192 symbol table contains regular, dynamic, or synthetic symbols, add all
193 the global function and data symbols to the minimal symbol table.
194
195 In stabs-in-ELF, as implemented by Sun, there are some local symbols
196 defined in the ELF symbol table, which can be used to locate
197 the beginnings of sections from each ".o" file that was linked to
198 form the executable objfile. We gather any such info and record it
199 in data structures hung off the objfile's private data.
200
201 */
202
203#define ST_REGULAR 0
204#define ST_DYNAMIC 1
205#define ST_SYNTHETIC 2
206
207static void
208elf_symtab_read (struct objfile *objfile, int type,
209 long number_of_symbols, asymbol **symbol_table)
210{
211 struct gdbarch *gdbarch = get_objfile_arch (objfile);
212 long storage_needed;
213 asymbol *sym;
214 long i;
215 CORE_ADDR symaddr;
216 CORE_ADDR offset;
217 enum minimal_symbol_type ms_type;
218 /* If sectinfo is nonNULL, it contains section info that should end up
219 filed in the objfile. */
220 struct stab_section_info *sectinfo = NULL;
221 /* If filesym is nonzero, it points to a file symbol, but we haven't
222 seen any section info for it yet. */
223 asymbol *filesym = 0;
224 /* Name of filesym, as saved on the objfile_obstack. */
225 char *filesymname = obsavestring ("", 0, &objfile->objfile_obstack);
226 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
227 int stripped = (bfd_get_symcount (objfile->obfd) == 0);
228
229 for (i = 0; i < number_of_symbols; i++)
230 {
231 sym = symbol_table[i];
232 if (sym->name == NULL || *sym->name == '\0')
233 {
234 /* Skip names that don't exist (shouldn't happen), or names
235 that are null strings (may happen). */
236 continue;
237 }
238
239 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
240 symbols which do not correspond to objects in the symbol table,
241 but have some other target-specific meaning. */
242 if (bfd_is_target_special_symbol (objfile->obfd, sym))
243 {
244 if (gdbarch_record_special_symbol_p (gdbarch))
245 gdbarch_record_special_symbol (gdbarch, objfile, sym);
246 continue;
247 }
248
249 offset = ANOFFSET (objfile->section_offsets, sym->section->index);
250 if (type == ST_DYNAMIC
251 && sym->section == &bfd_und_section
252 && (sym->flags & BSF_FUNCTION))
253 {
254 struct minimal_symbol *msym;
255 bfd *abfd = objfile->obfd;
256 asection *sect;
257
258 /* Symbol is a reference to a function defined in
259 a shared library.
260 If its value is non zero then it is usually the address
261 of the corresponding entry in the procedure linkage table,
262 plus the desired section offset.
263 If its value is zero then the dynamic linker has to resolve
264 the symbol. We are unable to find any meaningful address
265 for this symbol in the executable file, so we skip it. */
266 symaddr = sym->value;
267 if (symaddr == 0)
268 continue;
269
270 /* sym->section is the undefined section. However, we want to
271 record the section where the PLT stub resides with the
272 minimal symbol. Search the section table for the one that
273 covers the stub's address. */
274 for (sect = abfd->sections; sect != NULL; sect = sect->next)
275 {
276 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
277 continue;
278
279 if (symaddr >= bfd_get_section_vma (abfd, sect)
280 && symaddr < bfd_get_section_vma (abfd, sect)
281 + bfd_get_section_size (sect))
282 break;
283 }
284 if (!sect)
285 continue;
286
287 symaddr += ANOFFSET (objfile->section_offsets, sect->index);
288
289 msym = record_minimal_symbol
290 ((char *) sym->name, symaddr, mst_solib_trampoline, sect, objfile);
291 if (msym != NULL)
292 msym->filename = filesymname;
293 continue;
294 }
295
296 /* If it is a nonstripped executable, do not enter dynamic
297 symbols, as the dynamic symbol table is usually a subset
298 of the main symbol table. */
299 if (type == ST_DYNAMIC && !stripped)
300 continue;
301 if (sym->flags & BSF_FILE)
302 {
303 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
304 Chain any old one onto the objfile; remember new sym. */
305 if (sectinfo != NULL)
306 {
307 sectinfo->next = dbx->stab_section_info;
308 dbx->stab_section_info = sectinfo;
309 sectinfo = NULL;
310 }
311 filesym = sym;
312 filesymname =
313 obsavestring ((char *) filesym->name, strlen (filesym->name),
314 &objfile->objfile_obstack);
315 }
316 else if (sym->flags & BSF_SECTION_SYM)
317 continue;
318 else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK))
319 {
320 struct minimal_symbol *msym;
321
322 /* Select global/local/weak symbols. Note that bfd puts abs
323 symbols in their own section, so all symbols we are
324 interested in will have a section. */
325 /* Bfd symbols are section relative. */
326 symaddr = sym->value + sym->section->vma;
327 /* Relocate all non-absolute and non-TLS symbols by the
328 section offset. */
329 if (sym->section != &bfd_abs_section
330 && !(sym->section->flags & SEC_THREAD_LOCAL))
331 {
332 symaddr += offset;
333 }
334 /* For non-absolute symbols, use the type of the section
335 they are relative to, to intuit text/data. Bfd provides
336 no way of figuring this out for absolute symbols. */
337 if (sym->section == &bfd_abs_section)
338 {
339 /* This is a hack to get the minimal symbol type
340 right for Irix 5, which has absolute addresses
341 with special section indices for dynamic symbols.
342
343 NOTE: uweigand-20071112: Synthetic symbols do not
344 have an ELF-private part, so do not touch those. */
345 unsigned int shndx = type == ST_SYNTHETIC ? 0 :
346 ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx;
347
348 switch (shndx)
349 {
350 case SHN_MIPS_TEXT:
351 ms_type = mst_text;
352 break;
353 case SHN_MIPS_DATA:
354 ms_type = mst_data;
355 break;
356 case SHN_MIPS_ACOMMON:
357 ms_type = mst_bss;
358 break;
359 default:
360 ms_type = mst_abs;
361 }
362
363 /* If it is an Irix dynamic symbol, skip section name
364 symbols, relocate all others by section offset. */
365 if (ms_type != mst_abs)
366 {
367 if (sym->name[0] == '.')
368 continue;
369 symaddr += offset;
370 }
371 }
372 else if (sym->section->flags & SEC_CODE)
373 {
374 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
375 {
376 ms_type = mst_text;
377 }
378 else if ((sym->name[0] == '.' && sym->name[1] == 'L')
379 || ((sym->flags & BSF_LOCAL)
380 && sym->name[0] == '$'
381 && sym->name[1] == 'L'))
382 /* Looks like a compiler-generated label. Skip
383 it. The assembler should be skipping these (to
384 keep executables small), but apparently with
385 gcc on the (deleted) delta m88k SVR4, it loses.
386 So to have us check too should be harmless (but
387 I encourage people to fix this in the assembler
388 instead of adding checks here). */
389 continue;
390 else
391 {
392 ms_type = mst_file_text;
393 }
394 }
395 else if (sym->section->flags & SEC_ALLOC)
396 {
397 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
398 {
399 if (sym->section->flags & SEC_LOAD)
400 {
401 ms_type = mst_data;
402 }
403 else
404 {
405 ms_type = mst_bss;
406 }
407 }
408 else if (sym->flags & BSF_LOCAL)
409 {
410 /* Named Local variable in a Data section.
411 Check its name for stabs-in-elf. */
412 int special_local_sect;
413 if (strcmp ("Bbss.bss", sym->name) == 0)
414 special_local_sect = SECT_OFF_BSS (objfile);
415 else if (strcmp ("Ddata.data", sym->name) == 0)
416 special_local_sect = SECT_OFF_DATA (objfile);
417 else if (strcmp ("Drodata.rodata", sym->name) == 0)
418 special_local_sect = SECT_OFF_RODATA (objfile);
419 else
420 special_local_sect = -1;
421 if (special_local_sect >= 0)
422 {
423 /* Found a special local symbol. Allocate a
424 sectinfo, if needed, and fill it in. */
425 if (sectinfo == NULL)
426 {
427 int max_index;
428 size_t size;
429
430 max_index = SECT_OFF_BSS (objfile);
431 if (objfile->sect_index_data > max_index)
432 max_index = objfile->sect_index_data;
433 if (objfile->sect_index_rodata > max_index)
434 max_index = objfile->sect_index_rodata;
435
436 /* max_index is the largest index we'll
437 use into this array, so we must
438 allocate max_index+1 elements for it.
439 However, 'struct stab_section_info'
440 already includes one element, so we
441 need to allocate max_index aadditional
442 elements. */
443 size = (sizeof (struct stab_section_info)
444 + (sizeof (CORE_ADDR)
445 * max_index));
446 sectinfo = (struct stab_section_info *)
447 xmalloc (size);
448 memset (sectinfo, 0, size);
449 sectinfo->num_sections = max_index;
450 if (filesym == NULL)
451 {
452 complaint (&symfile_complaints,
453 _("elf/stab section information %s without a preceding file symbol"),
454 sym->name);
455 }
456 else
457 {
458 sectinfo->filename =
459 (char *) filesym->name;
460 }
461 }
462 if (sectinfo->sections[special_local_sect] != 0)
463 complaint (&symfile_complaints,
464 _("duplicated elf/stab section information for %s"),
465 sectinfo->filename);
466 /* BFD symbols are section relative. */
467 symaddr = sym->value + sym->section->vma;
468 /* Relocate non-absolute symbols by the
469 section offset. */
470 if (sym->section != &bfd_abs_section)
471 symaddr += offset;
472 sectinfo->sections[special_local_sect] = symaddr;
473 /* The special local symbols don't go in the
474 minimal symbol table, so ignore this one. */
475 continue;
476 }
477 /* Not a special stabs-in-elf symbol, do regular
478 symbol processing. */
479 if (sym->section->flags & SEC_LOAD)
480 {
481 ms_type = mst_file_data;
482 }
483 else
484 {
485 ms_type = mst_file_bss;
486 }
487 }
488 else
489 {
490 ms_type = mst_unknown;
491 }
492 }
493 else
494 {
495 /* FIXME: Solaris2 shared libraries include lots of
496 odd "absolute" and "undefined" symbols, that play
497 hob with actions like finding what function the PC
498 is in. Ignore them if they aren't text, data, or bss. */
499 /* ms_type = mst_unknown; */
500 continue; /* Skip this symbol. */
501 }
502 msym = record_minimal_symbol
503 ((char *) sym->name, symaddr,
504 ms_type, sym->section, objfile);
505
506 if (msym)
507 {
508 /* Pass symbol size field in via BFD. FIXME!!! */
509 elf_symbol_type *elf_sym;
510
511 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
512 ELF-private part. However, in some cases (e.g. synthetic
513 'dot' symbols on ppc64) the udata.p entry is set to point back
514 to the original ELF symbol it was derived from. Get the size
515 from that symbol. */
516 if (type != ST_SYNTHETIC)
517 elf_sym = (elf_symbol_type *) sym;
518 else
519 elf_sym = (elf_symbol_type *) sym->udata.p;
520
521 if (elf_sym)
522 MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size;
523 }
524 if (msym != NULL)
525 msym->filename = filesymname;
526 gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
527
528 /* For @plt symbols, also record a trampoline to the
529 destination symbol. The @plt symbol will be used in
530 disassembly, and the trampoline will be used when we are
531 trying to find the target. */
532 if (msym && ms_type == mst_text && type == ST_SYNTHETIC)
533 {
534 int len = strlen (sym->name);
535
536 if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
537 {
538 char *base_name = alloca (len - 4 + 1);
539 struct minimal_symbol *mtramp;
540
541 memcpy (base_name, sym->name, len - 4);
542 base_name[len - 4] = '\0';
543 mtramp = record_minimal_symbol (base_name, symaddr,
544 mst_solib_trampoline,
545 sym->section, objfile);
546 if (mtramp)
547 {
548 MSYMBOL_SIZE (mtramp) = MSYMBOL_SIZE (msym);
549 mtramp->filename = filesymname;
550 gdbarch_elf_make_msymbol_special (gdbarch, sym, mtramp);
551 }
552 }
553 }
554 }
555 }
556}
557
558/* Scan and build partial symbols for a symbol file.
559 We have been initialized by a call to elf_symfile_init, which
560 currently does nothing.
561
562 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
563 in each section. We simplify it down to a single offset for all
564 symbols. FIXME.
565
566 MAINLINE is true if we are reading the main symbol
567 table (as opposed to a shared lib or dynamically loaded file).
568
569 This function only does the minimum work necessary for letting the
570 user "name" things symbolically; it does not read the entire symtab.
571 Instead, it reads the external and static symbols and puts them in partial
572 symbol tables. When more extensive information is requested of a
573 file, the corresponding partial symbol table is mutated into a full
574 fledged symbol table by going back and reading the symbols
575 for real.
576
577 We look for sections with specific names, to tell us what debug
578 format to look for: FIXME!!!
579
580 elfstab_build_psymtabs() handles STABS symbols;
581 mdebug_build_psymtabs() handles ECOFF debugging information.
582
583 Note that ELF files have a "minimal" symbol table, which looks a lot
584 like a COFF symbol table, but has only the minimal information necessary
585 for linking. We process this also, and use the information to
586 build gdb's minimal symbol table. This gives us some minimal debugging
587 capability even for files compiled without -g. */
588
589static void
590elf_symfile_read (struct objfile *objfile, int mainline)
591{
592 bfd *abfd = objfile->obfd;
593 struct elfinfo ei;
594 struct cleanup *back_to;
595 CORE_ADDR offset;
596 long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
597 asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
598 asymbol *synthsyms;
599
600 init_minimal_symbol_collection ();
601 back_to = make_cleanup_discard_minimal_symbols ();
602
603 memset ((char *) &ei, 0, sizeof (ei));
604
605 /* Allocate struct to keep track of the symfile */
606 objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *)
607 xmalloc (sizeof (struct dbx_symfile_info));
608 memset ((char *) objfile->deprecated_sym_stab_info, 0, sizeof (struct dbx_symfile_info));
609 make_cleanup (free_elfinfo, (void *) objfile);
610
611 /* Process the normal ELF symbol table first. This may write some
612 chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info,
613 which can later be used by elfstab_offset_sections. */
614
615 storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
616 if (storage_needed < 0)
617 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
618 bfd_errmsg (bfd_get_error ()));
619
620 if (storage_needed > 0)
621 {
622 symbol_table = (asymbol **) xmalloc (storage_needed);
623 make_cleanup (xfree, symbol_table);
624 symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
625
626 if (symcount < 0)
627 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
628 bfd_errmsg (bfd_get_error ()));
629
630 elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table);
631 }
632
633 /* Add the dynamic symbols. */
634
635 storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd);
636
637 if (storage_needed > 0)
638 {
639 dyn_symbol_table = (asymbol **) xmalloc (storage_needed);
640 make_cleanup (xfree, dyn_symbol_table);
641 dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
642 dyn_symbol_table);
643
644 if (dynsymcount < 0)
645 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
646 bfd_errmsg (bfd_get_error ()));
647
648 elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table);
649 }
650
651 /* Add synthetic symbols - for instance, names for any PLT entries. */
652
653 synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table,
654 dynsymcount, dyn_symbol_table,
655 &synthsyms);
656 if (synthcount > 0)
657 {
658 asymbol **synth_symbol_table;
659 long i;
660
661 make_cleanup (xfree, synthsyms);
662 synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount);
663 for (i = 0; i < synthcount; i++)
664 synth_symbol_table[i] = synthsyms + i;
665 make_cleanup (xfree, synth_symbol_table);
666 elf_symtab_read (objfile, ST_SYNTHETIC, synthcount, synth_symbol_table);
667 }
668
669 /* Install any minimal symbols that have been collected as the current
670 minimal symbols for this objfile. The debug readers below this point
671 should not generate new minimal symbols; if they do it's their
672 responsibility to install them. "mdebug" appears to be the only one
673 which will do this. */
674
675 install_minimal_symbols (objfile);
676 do_cleanups (back_to);
677
678 /* Now process debugging information, which is contained in
679 special ELF sections. */
680
681 /* If we are reinitializing, or if we have never loaded syms yet,
682 set table to empty. MAINLINE is cleared so that *_read_psymtab
683 functions do not all also re-initialize the psymbol table. */
684 if (mainline)
685 {
686 init_psymbol_list (objfile, 0);
687 mainline = 0;
688 }
689
690 /* We first have to find them... */
691 bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
692
693 /* ELF debugging information is inserted into the psymtab in the
694 order of least informative first - most informative last. Since
695 the psymtab table is searched `most recent insertion first' this
696 increases the probability that more detailed debug information
697 for a section is found.
698
699 For instance, an object file might contain both .mdebug (XCOFF)
700 and .debug_info (DWARF2) sections then .mdebug is inserted first
701 (searched last) and DWARF2 is inserted last (searched first). If
702 we don't do this then the XCOFF info is found first - for code in
703 an included file XCOFF info is useless. */
704
705 if (ei.mdebugsect)
706 {
707 const struct ecoff_debug_swap *swap;
708
709 /* .mdebug section, presumably holding ECOFF debugging
710 information. */
711 swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap;
712 if (swap)
713 elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect);
714 }
715 if (ei.stabsect)
716 {
717 asection *str_sect;
718
719 /* Stab sections have an associated string table that looks like
720 a separate section. */
721 str_sect = bfd_get_section_by_name (abfd, ".stabstr");
722
723 /* FIXME should probably warn about a stab section without a stabstr. */
724 if (str_sect)
725 elfstab_build_psymtabs (objfile,
726 mainline,
727 ei.stabsect,
728 str_sect->filepos,
729 bfd_section_size (abfd, str_sect));
730 }
731 if (dwarf2_has_info (objfile))
732 {
733 /* DWARF 2 sections */
734 dwarf2_build_psymtabs (objfile, mainline);
735 }
736
737 /* FIXME: kettenis/20030504: This still needs to be integrated with
738 dwarf2read.c in a better way. */
739 dwarf2_build_frame_info (objfile);
740}
741
742/* This cleans up the objfile's deprecated_sym_stab_info pointer, and
743 the chain of stab_section_info's, that might be dangling from
744 it. */
745
746static void
747free_elfinfo (void *objp)
748{
749 struct objfile *objfile = (struct objfile *) objp;
750 struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info;
751 struct stab_section_info *ssi, *nssi;
752
753 ssi = dbxinfo->stab_section_info;
754 while (ssi)
755 {
756 nssi = ssi->next;
757 xfree (ssi);
758 ssi = nssi;
759 }
760
761 dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */
762}
763
764
765/* Initialize anything that needs initializing when a completely new symbol
766 file is specified (not just adding some symbols from another file, e.g. a
767 shared library).
768
769 We reinitialize buildsym, since we may be reading stabs from an ELF file. */
770
771static void
772elf_new_init (struct objfile *ignore)
773{
774 stabsread_new_init ();
775 buildsym_new_init ();
776}
777
778/* Perform any local cleanups required when we are done with a particular
779 objfile. I.E, we are in the process of discarding all symbol information
780 for an objfile, freeing up all memory held for it, and unlinking the
781 objfile struct from the global list of known objfiles. */
782
783static void
784elf_symfile_finish (struct objfile *objfile)
785{
786 if (objfile->deprecated_sym_stab_info != NULL)
787 {
788 xfree (objfile->deprecated_sym_stab_info);
789 }
790
791 dwarf2_free_objfile (objfile);
792}
793
794/* ELF specific initialization routine for reading symbols.
795
796 It is passed a pointer to a struct sym_fns which contains, among other
797 things, the BFD for the file whose symbols are being read, and a slot for
798 a pointer to "private data" which we can fill with goodies.
799
800 For now at least, we have nothing in particular to do, so this function is
801 just a stub. */
802
803static void
804elf_symfile_init (struct objfile *objfile)
805{
806 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
807 find this causes a significant slowdown in gdb then we could
808 set it in the debug symbol readers only when necessary. */
809 objfile->flags |= OBJF_REORDERED;
810}
811
812/* When handling an ELF file that contains Sun STABS debug info,
813 some of the debug info is relative to the particular chunk of the
814 section that was generated in its individual .o file. E.g.
815 offsets to static variables are relative to the start of the data
816 segment *for that module before linking*. This information is
817 painfully squirreled away in the ELF symbol table as local symbols
818 with wierd names. Go get 'em when needed. */
819
820void
821elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst)
822{
823 char *filename = pst->filename;
824 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
825 struct stab_section_info *maybe = dbx->stab_section_info;
826 struct stab_section_info *questionable = 0;
827 int i;
828 char *p;
829
830 /* The ELF symbol info doesn't include path names, so strip the path
831 (if any) from the psymtab filename. */
832 while (0 != (p = strchr (filename, '/')))
833 filename = p + 1;
834
835 /* FIXME: This linear search could speed up significantly
836 if it was chained in the right order to match how we search it,
837 and if we unchained when we found a match. */
838 for (; maybe; maybe = maybe->next)
839 {
840 if (filename[0] == maybe->filename[0]
841 && strcmp (filename, maybe->filename) == 0)
842 {
843 /* We found a match. But there might be several source files
844 (from different directories) with the same name. */
845 if (0 == maybe->found)
846 break;
847 questionable = maybe; /* Might use it later. */
848 }
849 }
850
851 if (maybe == 0 && questionable != 0)
852 {
853 complaint (&symfile_complaints,
854 _("elf/stab section information questionable for %s"), filename);
855 maybe = questionable;
856 }
857
858 if (maybe)
859 {
860 /* Found it! Allocate a new psymtab struct, and fill it in. */
861 maybe->found++;
862 pst->section_offsets = (struct section_offsets *)
863 obstack_alloc (&objfile->objfile_obstack,
864 SIZEOF_N_SECTION_OFFSETS (objfile->num_sections));
865 for (i = 0; i < maybe->num_sections; i++)
866 (pst->section_offsets)->offsets[i] = maybe->sections[i];
867 return;
868 }
869
870 /* We were unable to find any offsets for this file. Complain. */
871 if (dbx->stab_section_info) /* If there *is* any info, */
872 complaint (&symfile_complaints,
873 _("elf/stab section information missing for %s"), filename);
874}
875\f
876/* Register that we are able to handle ELF object file formats. */
877
878static struct sym_fns elf_sym_fns =
879{
880 bfd_target_elf_flavour,
881 elf_new_init, /* sym_new_init: init anything gbl to entire symtab */
882 elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */
883 elf_symfile_read, /* sym_read: read a symbol file into symtab */
884 elf_symfile_finish, /* sym_finish: finished with file, cleanup */
885 default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */
886 elf_symfile_segments, /* sym_segments: Get segment information from
887 a file. */
888 NULL, /* sym_read_linetable */
889 NULL /* next: pointer to next struct sym_fns */
890};
891
892void
893_initialize_elfread (void)
894{
895 add_symtab_fns (&elf_sym_fns);
896}