1 /* Read ELF (Executable and Linking Format) object files for GDB.
3 Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 Written by Fred Fish at Cygnus Support.
9 This file is part of GDB.
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.
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.
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/>. */
26 #include "gdb_string.h"
28 #include "elf/common.h"
29 #include "elf/internal.h"
35 #include "stabsread.h"
36 #include "gdb-stabs.h"
37 #include "complaints.h"
41 extern void _initialize_elfread (void);
43 /* Forward declaration. */
44 static const struct sym_fns elf_sym_fns_gdb_index
;
46 /* The struct elfinfo is available only during ELF symbol table and
47 psymtab reading. It is destroyed at the completion of psymtab-reading.
48 It's local to elf_symfile_read. */
52 asection
*stabsect
; /* Section pointer for .stab section */
53 asection
*stabindexsect
; /* Section pointer for .stab.index section */
54 asection
*mdebugsect
; /* Section pointer for .mdebug section */
57 static void free_elfinfo (void *);
59 /* Locate the segments in ABFD. */
61 static struct symfile_segment_data
*
62 elf_symfile_segments (bfd
*abfd
)
64 Elf_Internal_Phdr
*phdrs
, **segments
;
66 int num_phdrs
, num_segments
, num_sections
, i
;
68 struct symfile_segment_data
*data
;
70 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
74 phdrs
= alloca (phdrs_size
);
75 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
80 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
81 for (i
= 0; i
< num_phdrs
; i
++)
82 if (phdrs
[i
].p_type
== PT_LOAD
)
83 segments
[num_segments
++] = &phdrs
[i
];
85 if (num_segments
== 0)
88 data
= XZALLOC (struct symfile_segment_data
);
89 data
->num_segments
= num_segments
;
90 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
91 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
93 for (i
= 0; i
< num_segments
; i
++)
95 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
96 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
99 num_sections
= bfd_count_sections (abfd
);
100 data
->segment_info
= XCALLOC (num_sections
, int);
102 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
107 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
110 vma
= bfd_get_section_vma (abfd
, sect
);
112 for (j
= 0; j
< num_segments
; j
++)
113 if (segments
[j
]->p_memsz
> 0
114 && vma
>= segments
[j
]->p_vaddr
115 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
117 data
->segment_info
[i
] = j
+ 1;
121 /* We should have found a segment for every non-empty section.
122 If we haven't, we will not relocate this section by any
123 offsets we apply to the segments. As an exception, do not
124 warn about SHT_NOBITS sections; in normal ELF execution
125 environments, SHT_NOBITS means zero-initialized and belongs
126 in a segment, but in no-OS environments some tools (e.g. ARM
127 RealView) use SHT_NOBITS for uninitialized data. Since it is
128 uninitialized, it doesn't need a program header. Such
129 binaries are not relocatable. */
130 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
131 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
132 warning (_("Loadable segment \"%s\" outside of ELF segments"),
133 bfd_section_name (abfd
, sect
));
139 /* We are called once per section from elf_symfile_read. We
140 need to examine each section we are passed, check to see
141 if it is something we are interested in processing, and
142 if so, stash away some access information for the section.
144 For now we recognize the dwarf debug information sections and
145 line number sections from matching their section names. The
146 ELF definition is no real help here since it has no direct
147 knowledge of DWARF (by design, so any debugging format can be
150 We also recognize the ".stab" sections used by the Sun compilers
151 released with Solaris 2.
153 FIXME: The section names should not be hardwired strings (what
154 should they be? I don't think most object file formats have enough
155 section flags to specify what kind of debug section it is.
159 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
163 ei
= (struct elfinfo
*) eip
;
164 if (strcmp (sectp
->name
, ".stab") == 0)
166 ei
->stabsect
= sectp
;
168 else if (strcmp (sectp
->name
, ".stab.index") == 0)
170 ei
->stabindexsect
= sectp
;
172 else if (strcmp (sectp
->name
, ".mdebug") == 0)
174 ei
->mdebugsect
= sectp
;
178 static struct minimal_symbol
*
179 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
181 enum minimal_symbol_type ms_type
,
182 asection
*bfd_section
, struct objfile
*objfile
)
184 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
186 if (ms_type
== mst_text
|| ms_type
== mst_file_text
)
187 address
= gdbarch_smash_text_address (gdbarch
, address
);
189 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
190 ms_type
, bfd_section
->index
,
191 bfd_section
, objfile
);
198 elf_symtab_read -- read the symbol table of an ELF file
202 void elf_symtab_read (struct objfile *objfile, int type,
203 long number_of_symbols, asymbol **symbol_table)
207 Given an objfile, a symbol table, and a flag indicating whether the
208 symbol table contains regular, dynamic, or synthetic symbols, add all
209 the global function and data symbols to the minimal symbol table.
211 In stabs-in-ELF, as implemented by Sun, there are some local symbols
212 defined in the ELF symbol table, which can be used to locate
213 the beginnings of sections from each ".o" file that was linked to
214 form the executable objfile. We gather any such info and record it
215 in data structures hung off the objfile's private data.
221 #define ST_SYNTHETIC 2
224 elf_symtab_read (struct objfile
*objfile
, int type
,
225 long number_of_symbols
, asymbol
**symbol_table
,
228 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
233 enum minimal_symbol_type ms_type
;
234 /* If sectinfo is nonNULL, it contains section info that should end up
235 filed in the objfile. */
236 struct stab_section_info
*sectinfo
= NULL
;
237 /* If filesym is nonzero, it points to a file symbol, but we haven't
238 seen any section info for it yet. */
239 asymbol
*filesym
= 0;
240 /* Name of filesym. This is either a constant string or is saved on
241 the objfile's obstack. */
242 char *filesymname
= "";
243 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
244 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
246 for (i
= 0; i
< number_of_symbols
; i
++)
248 sym
= symbol_table
[i
];
249 if (sym
->name
== NULL
|| *sym
->name
== '\0')
251 /* Skip names that don't exist (shouldn't happen), or names
252 that are null strings (may happen). */
256 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
257 symbols which do not correspond to objects in the symbol table,
258 but have some other target-specific meaning. */
259 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
261 if (gdbarch_record_special_symbol_p (gdbarch
))
262 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
266 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
267 if (type
== ST_DYNAMIC
268 && sym
->section
== &bfd_und_section
269 && (sym
->flags
& BSF_FUNCTION
))
271 struct minimal_symbol
*msym
;
272 bfd
*abfd
= objfile
->obfd
;
275 /* Symbol is a reference to a function defined in
277 If its value is non zero then it is usually the address
278 of the corresponding entry in the procedure linkage table,
279 plus the desired section offset.
280 If its value is zero then the dynamic linker has to resolve
281 the symbol. We are unable to find any meaningful address
282 for this symbol in the executable file, so we skip it. */
283 symaddr
= sym
->value
;
287 /* sym->section is the undefined section. However, we want to
288 record the section where the PLT stub resides with the
289 minimal symbol. Search the section table for the one that
290 covers the stub's address. */
291 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
293 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
296 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
297 && symaddr
< bfd_get_section_vma (abfd
, sect
)
298 + bfd_get_section_size (sect
))
304 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
306 msym
= record_minimal_symbol
307 (sym
->name
, strlen (sym
->name
), copy_names
,
308 symaddr
, mst_solib_trampoline
, sect
, objfile
);
310 msym
->filename
= filesymname
;
314 /* If it is a nonstripped executable, do not enter dynamic
315 symbols, as the dynamic symbol table is usually a subset
316 of the main symbol table. */
317 if (type
== ST_DYNAMIC
&& !stripped
)
319 if (sym
->flags
& BSF_FILE
)
321 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
322 Chain any old one onto the objfile; remember new sym. */
323 if (sectinfo
!= NULL
)
325 sectinfo
->next
= dbx
->stab_section_info
;
326 dbx
->stab_section_info
= sectinfo
;
331 obsavestring ((char *) filesym
->name
, strlen (filesym
->name
),
332 &objfile
->objfile_obstack
);
334 else if (sym
->flags
& BSF_SECTION_SYM
)
336 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
338 struct minimal_symbol
*msym
;
340 /* Select global/local/weak symbols. Note that bfd puts abs
341 symbols in their own section, so all symbols we are
342 interested in will have a section. */
343 /* Bfd symbols are section relative. */
344 symaddr
= sym
->value
+ sym
->section
->vma
;
345 /* Relocate all non-absolute and non-TLS symbols by the
347 if (sym
->section
!= &bfd_abs_section
348 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
352 /* For non-absolute symbols, use the type of the section
353 they are relative to, to intuit text/data. Bfd provides
354 no way of figuring this out for absolute symbols. */
355 if (sym
->section
== &bfd_abs_section
)
357 /* This is a hack to get the minimal symbol type
358 right for Irix 5, which has absolute addresses
359 with special section indices for dynamic symbols.
361 NOTE: uweigand-20071112: Synthetic symbols do not
362 have an ELF-private part, so do not touch those. */
363 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
364 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
374 case SHN_MIPS_ACOMMON
:
381 /* If it is an Irix dynamic symbol, skip section name
382 symbols, relocate all others by section offset. */
383 if (ms_type
!= mst_abs
)
385 if (sym
->name
[0] == '.')
390 else if (sym
->section
->flags
& SEC_CODE
)
392 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
396 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L')
397 || ((sym
->flags
& BSF_LOCAL
)
398 && sym
->name
[0] == '$'
399 && sym
->name
[1] == 'L'))
400 /* Looks like a compiler-generated label. Skip
401 it. The assembler should be skipping these (to
402 keep executables small), but apparently with
403 gcc on the (deleted) delta m88k SVR4, it loses.
404 So to have us check too should be harmless (but
405 I encourage people to fix this in the assembler
406 instead of adding checks here). */
410 ms_type
= mst_file_text
;
413 else if (sym
->section
->flags
& SEC_ALLOC
)
415 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
417 if (sym
->section
->flags
& SEC_LOAD
)
426 else if (sym
->flags
& BSF_LOCAL
)
428 /* Named Local variable in a Data section.
429 Check its name for stabs-in-elf. */
430 int special_local_sect
;
432 if (strcmp ("Bbss.bss", sym
->name
) == 0)
433 special_local_sect
= SECT_OFF_BSS (objfile
);
434 else if (strcmp ("Ddata.data", sym
->name
) == 0)
435 special_local_sect
= SECT_OFF_DATA (objfile
);
436 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
437 special_local_sect
= SECT_OFF_RODATA (objfile
);
439 special_local_sect
= -1;
440 if (special_local_sect
>= 0)
442 /* Found a special local symbol. Allocate a
443 sectinfo, if needed, and fill it in. */
444 if (sectinfo
== NULL
)
449 max_index
= SECT_OFF_BSS (objfile
);
450 if (objfile
->sect_index_data
> max_index
)
451 max_index
= objfile
->sect_index_data
;
452 if (objfile
->sect_index_rodata
> max_index
)
453 max_index
= objfile
->sect_index_rodata
;
455 /* max_index is the largest index we'll
456 use into this array, so we must
457 allocate max_index+1 elements for it.
458 However, 'struct stab_section_info'
459 already includes one element, so we
460 need to allocate max_index aadditional
462 size
= (sizeof (struct stab_section_info
)
463 + (sizeof (CORE_ADDR
)
465 sectinfo
= (struct stab_section_info
*)
467 memset (sectinfo
, 0, size
);
468 sectinfo
->num_sections
= max_index
;
471 complaint (&symfile_complaints
,
472 _("elf/stab section information %s "
473 "without a preceding file symbol"),
479 (char *) filesym
->name
;
482 if (sectinfo
->sections
[special_local_sect
] != 0)
483 complaint (&symfile_complaints
,
484 _("duplicated elf/stab section "
485 "information for %s"),
487 /* BFD symbols are section relative. */
488 symaddr
= sym
->value
+ sym
->section
->vma
;
489 /* Relocate non-absolute symbols by the
491 if (sym
->section
!= &bfd_abs_section
)
493 sectinfo
->sections
[special_local_sect
] = symaddr
;
494 /* The special local symbols don't go in the
495 minimal symbol table, so ignore this one. */
498 /* Not a special stabs-in-elf symbol, do regular
499 symbol processing. */
500 if (sym
->section
->flags
& SEC_LOAD
)
502 ms_type
= mst_file_data
;
506 ms_type
= mst_file_bss
;
511 ms_type
= mst_unknown
;
516 /* FIXME: Solaris2 shared libraries include lots of
517 odd "absolute" and "undefined" symbols, that play
518 hob with actions like finding what function the PC
519 is in. Ignore them if they aren't text, data, or bss. */
520 /* ms_type = mst_unknown; */
521 continue; /* Skip this symbol. */
523 msym
= record_minimal_symbol
524 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
525 ms_type
, sym
->section
, objfile
);
529 /* Pass symbol size field in via BFD. FIXME!!! */
530 elf_symbol_type
*elf_sym
;
532 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
533 ELF-private part. However, in some cases (e.g. synthetic
534 'dot' symbols on ppc64) the udata.p entry is set to point back
535 to the original ELF symbol it was derived from. Get the size
537 if (type
!= ST_SYNTHETIC
)
538 elf_sym
= (elf_symbol_type
*) sym
;
540 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
543 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
545 msym
->filename
= filesymname
;
546 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
549 /* For @plt symbols, also record a trampoline to the
550 destination symbol. The @plt symbol will be used in
551 disassembly, and the trampoline will be used when we are
552 trying to find the target. */
553 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
555 int len
= strlen (sym
->name
);
557 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
559 struct minimal_symbol
*mtramp
;
561 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
563 mst_solib_trampoline
,
564 sym
->section
, objfile
);
567 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
568 mtramp
->filename
= filesymname
;
569 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
583 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
585 static struct build_id
*
586 build_id_bfd_get (bfd
*abfd
)
588 struct build_id
*retval
;
590 if (!bfd_check_format (abfd
, bfd_object
)
591 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
592 || elf_tdata (abfd
)->build_id
== NULL
)
595 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
596 retval
->size
= elf_tdata (abfd
)->build_id_size
;
597 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
602 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
605 build_id_verify (const char *filename
, struct build_id
*check
)
608 struct build_id
*found
= NULL
;
611 /* We expect to be silent on the non-existing files. */
612 abfd
= bfd_open_maybe_remote (filename
);
616 found
= build_id_bfd_get (abfd
);
619 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
620 else if (found
->size
!= check
->size
621 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
622 warning (_("File \"%s\" has a different build-id, file skipped"),
627 gdb_bfd_close_or_warn (abfd
);
635 build_id_to_debug_filename (struct build_id
*build_id
)
637 char *link
, *debugdir
, *retval
= NULL
;
639 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
640 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
641 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
643 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
644 cause "/.build-id/..." lookups. */
646 debugdir
= debug_file_directory
;
649 char *s
, *debugdir_end
;
650 gdb_byte
*data
= build_id
->data
;
651 size_t size
= build_id
->size
;
653 while (*debugdir
== DIRNAME_SEPARATOR
)
656 debugdir_end
= strchr (debugdir
, DIRNAME_SEPARATOR
);
657 if (debugdir_end
== NULL
)
658 debugdir_end
= &debugdir
[strlen (debugdir
)];
660 memcpy (link
, debugdir
, debugdir_end
- debugdir
);
661 s
= &link
[debugdir_end
- debugdir
];
662 s
+= sprintf (s
, "/.build-id/");
666 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
671 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
672 strcpy (s
, ".debug");
674 /* lrealpath() is expensive even for the usually non-existent files. */
675 if (access (link
, F_OK
) == 0)
676 retval
= lrealpath (link
);
678 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
687 debugdir
= debugdir_end
;
689 while (*debugdir
!= 0);
695 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
697 struct build_id
*build_id
;
699 build_id
= build_id_bfd_get (objfile
->obfd
);
700 if (build_id
!= NULL
)
704 build_id_name
= build_id_to_debug_filename (build_id
);
706 /* Prevent looping on a stripped .debug file. */
707 if (build_id_name
!= NULL
&& strcmp (build_id_name
, objfile
->name
) == 0)
709 warning (_("\"%s\": separate debug info file has no debug info"),
711 xfree (build_id_name
);
713 else if (build_id_name
!= NULL
)
714 return build_id_name
;
719 /* Scan and build partial symbols for a symbol file.
720 We have been initialized by a call to elf_symfile_init, which
721 currently does nothing.
723 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
724 in each section. We simplify it down to a single offset for all
727 This function only does the minimum work necessary for letting the
728 user "name" things symbolically; it does not read the entire symtab.
729 Instead, it reads the external and static symbols and puts them in partial
730 symbol tables. When more extensive information is requested of a
731 file, the corresponding partial symbol table is mutated into a full
732 fledged symbol table by going back and reading the symbols
735 We look for sections with specific names, to tell us what debug
736 format to look for: FIXME!!!
738 elfstab_build_psymtabs() handles STABS symbols;
739 mdebug_build_psymtabs() handles ECOFF debugging information.
741 Note that ELF files have a "minimal" symbol table, which looks a lot
742 like a COFF symbol table, but has only the minimal information necessary
743 for linking. We process this also, and use the information to
744 build gdb's minimal symbol table. This gives us some minimal debugging
745 capability even for files compiled without -g. */
748 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
750 bfd
*abfd
= objfile
->obfd
;
752 struct cleanup
*back_to
;
753 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
754 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
757 init_minimal_symbol_collection ();
758 back_to
= make_cleanup_discard_minimal_symbols ();
760 memset ((char *) &ei
, 0, sizeof (ei
));
762 /* Allocate struct to keep track of the symfile. */
763 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
764 xmalloc (sizeof (struct dbx_symfile_info
));
765 memset ((char *) objfile
->deprecated_sym_stab_info
,
766 0, sizeof (struct dbx_symfile_info
));
767 make_cleanup (free_elfinfo
, (void *) objfile
);
769 /* Process the normal ELF symbol table first. This may write some
770 chain of info into the dbx_symfile_info in
771 objfile->deprecated_sym_stab_info, which can later be used by
772 elfstab_offset_sections. */
774 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
775 if (storage_needed
< 0)
776 error (_("Can't read symbols from %s: %s"),
777 bfd_get_filename (objfile
->obfd
),
778 bfd_errmsg (bfd_get_error ()));
780 if (storage_needed
> 0)
782 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
783 make_cleanup (xfree
, symbol_table
);
784 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
787 error (_("Can't read symbols from %s: %s"),
788 bfd_get_filename (objfile
->obfd
),
789 bfd_errmsg (bfd_get_error ()));
791 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
794 /* Add the dynamic symbols. */
796 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
798 if (storage_needed
> 0)
800 /* Memory gets permanently referenced from ABFD after
801 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
802 It happens only in the case when elf_slurp_reloc_table sees
803 asection->relocation NULL. Determining which section is asection is
804 done by _bfd_elf_get_synthetic_symtab which is all a bfd
805 implementation detail, though. */
807 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
808 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
812 error (_("Can't read symbols from %s: %s"),
813 bfd_get_filename (objfile
->obfd
),
814 bfd_errmsg (bfd_get_error ()));
816 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
819 /* Add synthetic symbols - for instance, names for any PLT entries. */
821 synthcount
= bfd_get_synthetic_symtab (abfd
, symcount
, symbol_table
,
822 dynsymcount
, dyn_symbol_table
,
826 asymbol
**synth_symbol_table
;
829 make_cleanup (xfree
, synthsyms
);
830 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
831 for (i
= 0; i
< synthcount
; i
++)
832 synth_symbol_table
[i
] = synthsyms
+ i
;
833 make_cleanup (xfree
, synth_symbol_table
);
834 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
835 synth_symbol_table
, 1);
838 /* Install any minimal symbols that have been collected as the current
839 minimal symbols for this objfile. The debug readers below this point
840 should not generate new minimal symbols; if they do it's their
841 responsibility to install them. "mdebug" appears to be the only one
842 which will do this. */
844 install_minimal_symbols (objfile
);
845 do_cleanups (back_to
);
847 /* Now process debugging information, which is contained in
848 special ELF sections. */
850 /* We first have to find them... */
851 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
853 /* ELF debugging information is inserted into the psymtab in the
854 order of least informative first - most informative last. Since
855 the psymtab table is searched `most recent insertion first' this
856 increases the probability that more detailed debug information
857 for a section is found.
859 For instance, an object file might contain both .mdebug (XCOFF)
860 and .debug_info (DWARF2) sections then .mdebug is inserted first
861 (searched last) and DWARF2 is inserted last (searched first). If
862 we don't do this then the XCOFF info is found first - for code in
863 an included file XCOFF info is useless. */
867 const struct ecoff_debug_swap
*swap
;
869 /* .mdebug section, presumably holding ECOFF debugging
871 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
873 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
879 /* Stab sections have an associated string table that looks like
880 a separate section. */
881 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
883 /* FIXME should probably warn about a stab section without a stabstr. */
885 elfstab_build_psymtabs (objfile
,
888 bfd_section_size (abfd
, str_sect
));
891 if (dwarf2_has_info (objfile
) && dwarf2_initialize_objfile (objfile
))
892 objfile
->sf
= &elf_sym_fns_gdb_index
;
894 /* If the file has its own symbol tables it has no separate debug
895 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
896 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
897 `.note.gnu.build-id'. */
898 if (!objfile_has_partial_symbols (objfile
))
902 debugfile
= find_separate_debug_file_by_buildid (objfile
);
904 if (debugfile
== NULL
)
905 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
909 bfd
*abfd
= symfile_bfd_open (debugfile
);
911 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
917 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
918 the chain of stab_section_info's, that might be dangling from
922 free_elfinfo (void *objp
)
924 struct objfile
*objfile
= (struct objfile
*) objp
;
925 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
926 struct stab_section_info
*ssi
, *nssi
;
928 ssi
= dbxinfo
->stab_section_info
;
936 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
940 /* Initialize anything that needs initializing when a completely new symbol
941 file is specified (not just adding some symbols from another file, e.g. a
944 We reinitialize buildsym, since we may be reading stabs from an ELF
948 elf_new_init (struct objfile
*ignore
)
950 stabsread_new_init ();
951 buildsym_new_init ();
954 /* Perform any local cleanups required when we are done with a particular
955 objfile. I.E, we are in the process of discarding all symbol information
956 for an objfile, freeing up all memory held for it, and unlinking the
957 objfile struct from the global list of known objfiles. */
960 elf_symfile_finish (struct objfile
*objfile
)
962 if (objfile
->deprecated_sym_stab_info
!= NULL
)
964 xfree (objfile
->deprecated_sym_stab_info
);
967 dwarf2_free_objfile (objfile
);
970 /* ELF specific initialization routine for reading symbols.
972 It is passed a pointer to a struct sym_fns which contains, among other
973 things, the BFD for the file whose symbols are being read, and a slot for
974 a pointer to "private data" which we can fill with goodies.
976 For now at least, we have nothing in particular to do, so this function is
980 elf_symfile_init (struct objfile
*objfile
)
982 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
983 find this causes a significant slowdown in gdb then we could
984 set it in the debug symbol readers only when necessary. */
985 objfile
->flags
|= OBJF_REORDERED
;
988 /* When handling an ELF file that contains Sun STABS debug info,
989 some of the debug info is relative to the particular chunk of the
990 section that was generated in its individual .o file. E.g.
991 offsets to static variables are relative to the start of the data
992 segment *for that module before linking*. This information is
993 painfully squirreled away in the ELF symbol table as local symbols
994 with wierd names. Go get 'em when needed. */
997 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
999 const char *filename
= pst
->filename
;
1000 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
1001 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1002 struct stab_section_info
*questionable
= 0;
1006 /* The ELF symbol info doesn't include path names, so strip the path
1007 (if any) from the psymtab filename. */
1008 while (0 != (p
= strchr (filename
, '/')))
1011 /* FIXME: This linear search could speed up significantly
1012 if it was chained in the right order to match how we search it,
1013 and if we unchained when we found a match. */
1014 for (; maybe
; maybe
= maybe
->next
)
1016 if (filename
[0] == maybe
->filename
[0]
1017 && strcmp (filename
, maybe
->filename
) == 0)
1019 /* We found a match. But there might be several source files
1020 (from different directories) with the same name. */
1021 if (0 == maybe
->found
)
1023 questionable
= maybe
; /* Might use it later. */
1027 if (maybe
== 0 && questionable
!= 0)
1029 complaint (&symfile_complaints
,
1030 _("elf/stab section information questionable for %s"),
1032 maybe
= questionable
;
1037 /* Found it! Allocate a new psymtab struct, and fill it in. */
1039 pst
->section_offsets
= (struct section_offsets
*)
1040 obstack_alloc (&objfile
->objfile_obstack
,
1041 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1042 for (i
= 0; i
< maybe
->num_sections
; i
++)
1043 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1047 /* We were unable to find any offsets for this file. Complain. */
1048 if (dbx
->stab_section_info
) /* If there *is* any info, */
1049 complaint (&symfile_complaints
,
1050 _("elf/stab section information missing for %s"), filename
);
1053 /* Register that we are able to handle ELF object file formats. */
1055 static const struct sym_fns elf_sym_fns
=
1057 bfd_target_elf_flavour
,
1058 elf_new_init
, /* init anything gbl to entire symtab */
1059 elf_symfile_init
, /* read initial info, setup for sym_read() */
1060 elf_symfile_read
, /* read a symbol file into symtab */
1061 elf_symfile_finish
, /* finished with file, cleanup */
1062 default_symfile_offsets
, /* Translate ext. to int. relocation */
1063 elf_symfile_segments
, /* Get segment information from a file. */
1065 default_symfile_relocate
, /* Relocate a debug section. */
1069 /* The same as elf_sym_fns, but not registered and uses the
1070 DWARF-specific GNU index rather than psymtab. */
1071 static const struct sym_fns elf_sym_fns_gdb_index
=
1073 bfd_target_elf_flavour
,
1074 elf_new_init
, /* init anything gbl to entire symab */
1075 elf_symfile_init
, /* read initial info, setup for sym_red() */
1076 elf_symfile_read
, /* read a symbol file into symtab */
1077 elf_symfile_finish
, /* finished with file, cleanup */
1078 default_symfile_offsets
, /* Translate ext. to int. relocatin */
1079 elf_symfile_segments
, /* Get segment information from a file. */
1081 default_symfile_relocate
, /* Relocate a debug section. */
1082 &dwarf2_gdb_index_functions
1086 _initialize_elfread (void)
1088 add_symtab_fns (&elf_sym_fns
);