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"
40 #include "filenames.h"
42 extern void _initialize_elfread (void);
44 /* Forward declarations. */
45 static const struct sym_fns elf_sym_fns_gdb_index
;
46 static const struct sym_fns elf_sym_fns_lazy_psyms
;
48 /* The struct elfinfo is available only during ELF symbol table and
49 psymtab reading. It is destroyed at the completion of psymtab-reading.
50 It's local to elf_symfile_read. */
54 asection
*stabsect
; /* Section pointer for .stab section */
55 asection
*stabindexsect
; /* Section pointer for .stab.index section */
56 asection
*mdebugsect
; /* Section pointer for .mdebug section */
59 static void free_elfinfo (void *);
61 /* Locate the segments in ABFD. */
63 static struct symfile_segment_data
*
64 elf_symfile_segments (bfd
*abfd
)
66 Elf_Internal_Phdr
*phdrs
, **segments
;
68 int num_phdrs
, num_segments
, num_sections
, i
;
70 struct symfile_segment_data
*data
;
72 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
76 phdrs
= alloca (phdrs_size
);
77 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
82 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
83 for (i
= 0; i
< num_phdrs
; i
++)
84 if (phdrs
[i
].p_type
== PT_LOAD
)
85 segments
[num_segments
++] = &phdrs
[i
];
87 if (num_segments
== 0)
90 data
= XZALLOC (struct symfile_segment_data
);
91 data
->num_segments
= num_segments
;
92 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
93 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
95 for (i
= 0; i
< num_segments
; i
++)
97 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
98 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
101 num_sections
= bfd_count_sections (abfd
);
102 data
->segment_info
= XCALLOC (num_sections
, int);
104 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
109 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
112 vma
= bfd_get_section_vma (abfd
, sect
);
114 for (j
= 0; j
< num_segments
; j
++)
115 if (segments
[j
]->p_memsz
> 0
116 && vma
>= segments
[j
]->p_vaddr
117 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
119 data
->segment_info
[i
] = j
+ 1;
123 /* We should have found a segment for every non-empty section.
124 If we haven't, we will not relocate this section by any
125 offsets we apply to the segments. As an exception, do not
126 warn about SHT_NOBITS sections; in normal ELF execution
127 environments, SHT_NOBITS means zero-initialized and belongs
128 in a segment, but in no-OS environments some tools (e.g. ARM
129 RealView) use SHT_NOBITS for uninitialized data. Since it is
130 uninitialized, it doesn't need a program header. Such
131 binaries are not relocatable. */
132 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
133 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
134 warning (_("Loadable segment \"%s\" outside of ELF segments"),
135 bfd_section_name (abfd
, sect
));
141 /* We are called once per section from elf_symfile_read. We
142 need to examine each section we are passed, check to see
143 if it is something we are interested in processing, and
144 if so, stash away some access information for the section.
146 For now we recognize the dwarf debug information sections and
147 line number sections from matching their section names. The
148 ELF definition is no real help here since it has no direct
149 knowledge of DWARF (by design, so any debugging format can be
152 We also recognize the ".stab" sections used by the Sun compilers
153 released with Solaris 2.
155 FIXME: The section names should not be hardwired strings (what
156 should they be? I don't think most object file formats have enough
157 section flags to specify what kind of debug section it is.
161 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
165 ei
= (struct elfinfo
*) eip
;
166 if (strcmp (sectp
->name
, ".stab") == 0)
168 ei
->stabsect
= sectp
;
170 else if (strcmp (sectp
->name
, ".stab.index") == 0)
172 ei
->stabindexsect
= sectp
;
174 else if (strcmp (sectp
->name
, ".mdebug") == 0)
176 ei
->mdebugsect
= sectp
;
180 static struct minimal_symbol
*
181 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
183 enum minimal_symbol_type ms_type
,
184 asection
*bfd_section
, struct objfile
*objfile
)
186 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
188 if (ms_type
== mst_text
|| ms_type
== mst_file_text
)
189 address
= gdbarch_smash_text_address (gdbarch
, address
);
191 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
192 ms_type
, bfd_section
->index
,
193 bfd_section
, objfile
);
200 elf_symtab_read -- read the symbol table of an ELF file
204 void elf_symtab_read (struct objfile *objfile, int type,
205 long number_of_symbols, asymbol **symbol_table)
209 Given an objfile, a symbol table, and a flag indicating whether the
210 symbol table contains regular, dynamic, or synthetic symbols, add all
211 the global function and data symbols to the minimal symbol table.
213 In stabs-in-ELF, as implemented by Sun, there are some local symbols
214 defined in the ELF symbol table, which can be used to locate
215 the beginnings of sections from each ".o" file that was linked to
216 form the executable objfile. We gather any such info and record it
217 in data structures hung off the objfile's private data.
223 #define ST_SYNTHETIC 2
226 elf_symtab_read (struct objfile
*objfile
, int type
,
227 long number_of_symbols
, asymbol
**symbol_table
,
230 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
235 enum minimal_symbol_type ms_type
;
236 /* If sectinfo is nonNULL, it contains section info that should end up
237 filed in the objfile. */
238 struct stab_section_info
*sectinfo
= NULL
;
239 /* If filesym is nonzero, it points to a file symbol, but we haven't
240 seen any section info for it yet. */
241 asymbol
*filesym
= 0;
242 /* Name of filesym. This is either a constant string or is saved on
243 the objfile's obstack. */
244 char *filesymname
= "";
245 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
246 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
247 struct cleanup
*back_to
= make_cleanup (null_cleanup
, NULL
);
249 for (i
= 0; i
< number_of_symbols
; i
++)
251 sym
= symbol_table
[i
];
252 if (sym
->name
== NULL
|| *sym
->name
== '\0')
254 /* Skip names that don't exist (shouldn't happen), or names
255 that are null strings (may happen). */
259 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
260 symbols which do not correspond to objects in the symbol table,
261 but have some other target-specific meaning. */
262 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
264 if (gdbarch_record_special_symbol_p (gdbarch
))
265 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
269 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
270 if (type
== ST_DYNAMIC
271 && sym
->section
== &bfd_und_section
272 && (sym
->flags
& BSF_FUNCTION
))
274 struct minimal_symbol
*msym
;
275 bfd
*abfd
= objfile
->obfd
;
278 /* Symbol is a reference to a function defined in
280 If its value is non zero then it is usually the address
281 of the corresponding entry in the procedure linkage table,
282 plus the desired section offset.
283 If its value is zero then the dynamic linker has to resolve
284 the symbol. We are unable to find any meaningful address
285 for this symbol in the executable file, so we skip it. */
286 symaddr
= sym
->value
;
290 /* sym->section is the undefined section. However, we want to
291 record the section where the PLT stub resides with the
292 minimal symbol. Search the section table for the one that
293 covers the stub's address. */
294 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
296 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
299 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
300 && symaddr
< bfd_get_section_vma (abfd
, sect
)
301 + bfd_get_section_size (sect
))
307 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
309 msym
= record_minimal_symbol
310 (sym
->name
, strlen (sym
->name
), copy_names
,
311 symaddr
, mst_solib_trampoline
, sect
, objfile
);
313 msym
->filename
= filesymname
;
317 /* If it is a nonstripped executable, do not enter dynamic
318 symbols, as the dynamic symbol table is usually a subset
319 of the main symbol table. */
320 if (type
== ST_DYNAMIC
&& !stripped
)
322 if (sym
->flags
& BSF_FILE
)
324 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
325 Chain any old one onto the objfile; remember new sym. */
326 if (sectinfo
!= NULL
)
328 sectinfo
->next
= dbx
->stab_section_info
;
329 dbx
->stab_section_info
= sectinfo
;
334 obsavestring ((char *) filesym
->name
, strlen (filesym
->name
),
335 &objfile
->objfile_obstack
);
337 else if (sym
->flags
& BSF_SECTION_SYM
)
339 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
341 struct minimal_symbol
*msym
;
343 /* Select global/local/weak symbols. Note that bfd puts abs
344 symbols in their own section, so all symbols we are
345 interested in will have a section. */
346 /* Bfd symbols are section relative. */
347 symaddr
= sym
->value
+ sym
->section
->vma
;
348 /* Relocate all non-absolute and non-TLS symbols by the
350 if (sym
->section
!= &bfd_abs_section
351 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
355 /* For non-absolute symbols, use the type of the section
356 they are relative to, to intuit text/data. Bfd provides
357 no way of figuring this out for absolute symbols. */
358 if (sym
->section
== &bfd_abs_section
)
360 /* This is a hack to get the minimal symbol type
361 right for Irix 5, which has absolute addresses
362 with special section indices for dynamic symbols.
364 NOTE: uweigand-20071112: Synthetic symbols do not
365 have an ELF-private part, so do not touch those. */
366 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
367 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
377 case SHN_MIPS_ACOMMON
:
384 /* If it is an Irix dynamic symbol, skip section name
385 symbols, relocate all others by section offset. */
386 if (ms_type
!= mst_abs
)
388 if (sym
->name
[0] == '.')
393 else if (sym
->section
->flags
& SEC_CODE
)
395 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
399 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L')
400 || ((sym
->flags
& BSF_LOCAL
)
401 && sym
->name
[0] == '$'
402 && sym
->name
[1] == 'L'))
403 /* Looks like a compiler-generated label. Skip
404 it. The assembler should be skipping these (to
405 keep executables small), but apparently with
406 gcc on the (deleted) delta m88k SVR4, it loses.
407 So to have us check too should be harmless (but
408 I encourage people to fix this in the assembler
409 instead of adding checks here). */
413 ms_type
= mst_file_text
;
416 else if (sym
->section
->flags
& SEC_ALLOC
)
418 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
420 if (sym
->section
->flags
& SEC_LOAD
)
429 else if (sym
->flags
& BSF_LOCAL
)
431 /* Named Local variable in a Data section.
432 Check its name for stabs-in-elf. */
433 int special_local_sect
;
435 if (strcmp ("Bbss.bss", sym
->name
) == 0)
436 special_local_sect
= SECT_OFF_BSS (objfile
);
437 else if (strcmp ("Ddata.data", sym
->name
) == 0)
438 special_local_sect
= SECT_OFF_DATA (objfile
);
439 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
440 special_local_sect
= SECT_OFF_RODATA (objfile
);
442 special_local_sect
= -1;
443 if (special_local_sect
>= 0)
445 /* Found a special local symbol. Allocate a
446 sectinfo, if needed, and fill it in. */
447 if (sectinfo
== NULL
)
452 max_index
= SECT_OFF_BSS (objfile
);
453 if (objfile
->sect_index_data
> max_index
)
454 max_index
= objfile
->sect_index_data
;
455 if (objfile
->sect_index_rodata
> max_index
)
456 max_index
= objfile
->sect_index_rodata
;
458 /* max_index is the largest index we'll
459 use into this array, so we must
460 allocate max_index+1 elements for it.
461 However, 'struct stab_section_info'
462 already includes one element, so we
463 need to allocate max_index aadditional
465 size
= (sizeof (struct stab_section_info
)
466 + (sizeof (CORE_ADDR
) * max_index
));
467 sectinfo
= (struct stab_section_info
*)
469 make_cleanup (xfree
, sectinfo
);
470 memset (sectinfo
, 0, size
);
471 sectinfo
->num_sections
= max_index
;
474 complaint (&symfile_complaints
,
475 _("elf/stab section information %s "
476 "without a preceding file symbol"),
482 (char *) filesym
->name
;
485 if (sectinfo
->sections
[special_local_sect
] != 0)
486 complaint (&symfile_complaints
,
487 _("duplicated elf/stab section "
488 "information for %s"),
490 /* BFD symbols are section relative. */
491 symaddr
= sym
->value
+ sym
->section
->vma
;
492 /* Relocate non-absolute symbols by the
494 if (sym
->section
!= &bfd_abs_section
)
496 sectinfo
->sections
[special_local_sect
] = symaddr
;
497 /* The special local symbols don't go in the
498 minimal symbol table, so ignore this one. */
501 /* Not a special stabs-in-elf symbol, do regular
502 symbol processing. */
503 if (sym
->section
->flags
& SEC_LOAD
)
505 ms_type
= mst_file_data
;
509 ms_type
= mst_file_bss
;
514 ms_type
= mst_unknown
;
519 /* FIXME: Solaris2 shared libraries include lots of
520 odd "absolute" and "undefined" symbols, that play
521 hob with actions like finding what function the PC
522 is in. Ignore them if they aren't text, data, or bss. */
523 /* ms_type = mst_unknown; */
524 continue; /* Skip this symbol. */
526 msym
= record_minimal_symbol
527 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
528 ms_type
, sym
->section
, objfile
);
532 /* Pass symbol size field in via BFD. FIXME!!! */
533 elf_symbol_type
*elf_sym
;
535 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
536 ELF-private part. However, in some cases (e.g. synthetic
537 'dot' symbols on ppc64) the udata.p entry is set to point back
538 to the original ELF symbol it was derived from. Get the size
540 if (type
!= ST_SYNTHETIC
)
541 elf_sym
= (elf_symbol_type
*) sym
;
543 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
546 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
548 msym
->filename
= filesymname
;
549 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
552 /* For @plt symbols, also record a trampoline to the
553 destination symbol. The @plt symbol will be used in
554 disassembly, and the trampoline will be used when we are
555 trying to find the target. */
556 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
558 int len
= strlen (sym
->name
);
560 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
562 struct minimal_symbol
*mtramp
;
564 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
566 mst_solib_trampoline
,
567 sym
->section
, objfile
);
570 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
571 mtramp
->filename
= filesymname
;
572 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
578 do_cleanups (back_to
);
587 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
589 static struct build_id
*
590 build_id_bfd_get (bfd
*abfd
)
592 struct build_id
*retval
;
594 if (!bfd_check_format (abfd
, bfd_object
)
595 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
596 || elf_tdata (abfd
)->build_id
== NULL
)
599 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
600 retval
->size
= elf_tdata (abfd
)->build_id_size
;
601 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
606 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
609 build_id_verify (const char *filename
, struct build_id
*check
)
612 struct build_id
*found
= NULL
;
615 /* We expect to be silent on the non-existing files. */
616 abfd
= bfd_open_maybe_remote (filename
);
620 found
= build_id_bfd_get (abfd
);
623 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
624 else if (found
->size
!= check
->size
625 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
626 warning (_("File \"%s\" has a different build-id, file skipped"),
631 gdb_bfd_close_or_warn (abfd
);
639 build_id_to_debug_filename (struct build_id
*build_id
)
641 char *link
, *debugdir
, *retval
= NULL
;
643 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
644 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
645 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
647 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
648 cause "/.build-id/..." lookups. */
650 debugdir
= debug_file_directory
;
653 char *s
, *debugdir_end
;
654 gdb_byte
*data
= build_id
->data
;
655 size_t size
= build_id
->size
;
657 while (*debugdir
== DIRNAME_SEPARATOR
)
660 debugdir_end
= strchr (debugdir
, DIRNAME_SEPARATOR
);
661 if (debugdir_end
== NULL
)
662 debugdir_end
= &debugdir
[strlen (debugdir
)];
664 memcpy (link
, debugdir
, debugdir_end
- debugdir
);
665 s
= &link
[debugdir_end
- debugdir
];
666 s
+= sprintf (s
, "/.build-id/");
670 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
675 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
676 strcpy (s
, ".debug");
678 /* lrealpath() is expensive even for the usually non-existent files. */
679 if (access (link
, F_OK
) == 0)
680 retval
= lrealpath (link
);
682 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
691 debugdir
= debugdir_end
;
693 while (*debugdir
!= 0);
699 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
701 struct build_id
*build_id
;
703 build_id
= build_id_bfd_get (objfile
->obfd
);
704 if (build_id
!= NULL
)
708 build_id_name
= build_id_to_debug_filename (build_id
);
710 /* Prevent looping on a stripped .debug file. */
711 if (build_id_name
!= NULL
712 && filename_cmp (build_id_name
, objfile
->name
) == 0)
714 warning (_("\"%s\": separate debug info file has no debug info"),
716 xfree (build_id_name
);
718 else if (build_id_name
!= NULL
)
719 return build_id_name
;
724 /* Scan and build partial symbols for a symbol file.
725 We have been initialized by a call to elf_symfile_init, which
726 currently does nothing.
728 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
729 in each section. We simplify it down to a single offset for all
732 This function only does the minimum work necessary for letting the
733 user "name" things symbolically; it does not read the entire symtab.
734 Instead, it reads the external and static symbols and puts them in partial
735 symbol tables. When more extensive information is requested of a
736 file, the corresponding partial symbol table is mutated into a full
737 fledged symbol table by going back and reading the symbols
740 We look for sections with specific names, to tell us what debug
741 format to look for: FIXME!!!
743 elfstab_build_psymtabs() handles STABS symbols;
744 mdebug_build_psymtabs() handles ECOFF debugging information.
746 Note that ELF files have a "minimal" symbol table, which looks a lot
747 like a COFF symbol table, but has only the minimal information necessary
748 for linking. We process this also, and use the information to
749 build gdb's minimal symbol table. This gives us some minimal debugging
750 capability even for files compiled without -g. */
753 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
755 bfd
*abfd
= objfile
->obfd
;
757 struct cleanup
*back_to
;
758 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
759 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
762 init_minimal_symbol_collection ();
763 back_to
= make_cleanup_discard_minimal_symbols ();
765 memset ((char *) &ei
, 0, sizeof (ei
));
767 /* Allocate struct to keep track of the symfile. */
768 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
769 xmalloc (sizeof (struct dbx_symfile_info
));
770 memset ((char *) objfile
->deprecated_sym_stab_info
,
771 0, sizeof (struct dbx_symfile_info
));
772 make_cleanup (free_elfinfo
, (void *) objfile
);
774 /* Process the normal ELF symbol table first. This may write some
775 chain of info into the dbx_symfile_info in
776 objfile->deprecated_sym_stab_info, which can later be used by
777 elfstab_offset_sections. */
779 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
780 if (storage_needed
< 0)
781 error (_("Can't read symbols from %s: %s"),
782 bfd_get_filename (objfile
->obfd
),
783 bfd_errmsg (bfd_get_error ()));
785 if (storage_needed
> 0)
787 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
788 make_cleanup (xfree
, symbol_table
);
789 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
792 error (_("Can't read symbols from %s: %s"),
793 bfd_get_filename (objfile
->obfd
),
794 bfd_errmsg (bfd_get_error ()));
796 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
799 /* Add the dynamic symbols. */
801 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
803 if (storage_needed
> 0)
805 /* Memory gets permanently referenced from ABFD after
806 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
807 It happens only in the case when elf_slurp_reloc_table sees
808 asection->relocation NULL. Determining which section is asection is
809 done by _bfd_elf_get_synthetic_symtab which is all a bfd
810 implementation detail, though. */
812 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
813 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
817 error (_("Can't read symbols from %s: %s"),
818 bfd_get_filename (objfile
->obfd
),
819 bfd_errmsg (bfd_get_error ()));
821 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
824 /* Add synthetic symbols - for instance, names for any PLT entries. */
826 synthcount
= bfd_get_synthetic_symtab (abfd
, symcount
, symbol_table
,
827 dynsymcount
, dyn_symbol_table
,
831 asymbol
**synth_symbol_table
;
834 make_cleanup (xfree
, synthsyms
);
835 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
836 for (i
= 0; i
< synthcount
; i
++)
837 synth_symbol_table
[i
] = synthsyms
+ i
;
838 make_cleanup (xfree
, synth_symbol_table
);
839 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
840 synth_symbol_table
, 1);
843 /* Install any minimal symbols that have been collected as the current
844 minimal symbols for this objfile. The debug readers below this point
845 should not generate new minimal symbols; if they do it's their
846 responsibility to install them. "mdebug" appears to be the only one
847 which will do this. */
849 install_minimal_symbols (objfile
);
850 do_cleanups (back_to
);
852 /* Now process debugging information, which is contained in
853 special ELF sections. */
855 /* We first have to find them... */
856 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
858 /* ELF debugging information is inserted into the psymtab in the
859 order of least informative first - most informative last. Since
860 the psymtab table is searched `most recent insertion first' this
861 increases the probability that more detailed debug information
862 for a section is found.
864 For instance, an object file might contain both .mdebug (XCOFF)
865 and .debug_info (DWARF2) sections then .mdebug is inserted first
866 (searched last) and DWARF2 is inserted last (searched first). If
867 we don't do this then the XCOFF info is found first - for code in
868 an included file XCOFF info is useless. */
872 const struct ecoff_debug_swap
*swap
;
874 /* .mdebug section, presumably holding ECOFF debugging
876 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
878 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
884 /* Stab sections have an associated string table that looks like
885 a separate section. */
886 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
888 /* FIXME should probably warn about a stab section without a stabstr. */
890 elfstab_build_psymtabs (objfile
,
893 bfd_section_size (abfd
, str_sect
));
896 if (dwarf2_has_info (objfile
))
898 if (dwarf2_initialize_objfile (objfile
))
899 objfile
->sf
= &elf_sym_fns_gdb_index
;
902 /* It is ok to do this even if the stabs reader made some
903 partial symbols, because OBJF_PSYMTABS_READ has not been
904 set, and so our lazy reader function will still be called
906 objfile
->sf
= &elf_sym_fns_lazy_psyms
;
909 /* If the file has its own symbol tables it has no separate debug
910 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
911 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
912 `.note.gnu.build-id'. */
913 else if (!objfile_has_partial_symbols (objfile
))
917 debugfile
= find_separate_debug_file_by_buildid (objfile
);
919 if (debugfile
== NULL
)
920 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
924 bfd
*abfd
= symfile_bfd_open (debugfile
);
926 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
932 /* Callback to lazily read psymtabs. */
935 read_psyms (struct objfile
*objfile
)
937 if (dwarf2_has_info (objfile
))
938 dwarf2_build_psymtabs (objfile
);
941 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
942 the chain of stab_section_info's, that might be dangling from
946 free_elfinfo (void *objp
)
948 struct objfile
*objfile
= (struct objfile
*) objp
;
949 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
950 struct stab_section_info
*ssi
, *nssi
;
952 ssi
= dbxinfo
->stab_section_info
;
960 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
964 /* Initialize anything that needs initializing when a completely new symbol
965 file is specified (not just adding some symbols from another file, e.g. a
968 We reinitialize buildsym, since we may be reading stabs from an ELF
972 elf_new_init (struct objfile
*ignore
)
974 stabsread_new_init ();
975 buildsym_new_init ();
978 /* Perform any local cleanups required when we are done with a particular
979 objfile. I.E, we are in the process of discarding all symbol information
980 for an objfile, freeing up all memory held for it, and unlinking the
981 objfile struct from the global list of known objfiles. */
984 elf_symfile_finish (struct objfile
*objfile
)
986 if (objfile
->deprecated_sym_stab_info
!= NULL
)
988 xfree (objfile
->deprecated_sym_stab_info
);
991 dwarf2_free_objfile (objfile
);
994 /* ELF specific initialization routine for reading symbols.
996 It is passed a pointer to a struct sym_fns which contains, among other
997 things, the BFD for the file whose symbols are being read, and a slot for
998 a pointer to "private data" which we can fill with goodies.
1000 For now at least, we have nothing in particular to do, so this function is
1004 elf_symfile_init (struct objfile
*objfile
)
1006 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1007 find this causes a significant slowdown in gdb then we could
1008 set it in the debug symbol readers only when necessary. */
1009 objfile
->flags
|= OBJF_REORDERED
;
1012 /* When handling an ELF file that contains Sun STABS debug info,
1013 some of the debug info is relative to the particular chunk of the
1014 section that was generated in its individual .o file. E.g.
1015 offsets to static variables are relative to the start of the data
1016 segment *for that module before linking*. This information is
1017 painfully squirreled away in the ELF symbol table as local symbols
1018 with wierd names. Go get 'em when needed. */
1021 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
1023 const char *filename
= pst
->filename
;
1024 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
1025 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1026 struct stab_section_info
*questionable
= 0;
1029 /* The ELF symbol info doesn't include path names, so strip the path
1030 (if any) from the psymtab filename. */
1031 filename
= lbasename (filename
);
1033 /* FIXME: This linear search could speed up significantly
1034 if it was chained in the right order to match how we search it,
1035 and if we unchained when we found a match. */
1036 for (; maybe
; maybe
= maybe
->next
)
1038 if (filename
[0] == maybe
->filename
[0]
1039 && filename_cmp (filename
, maybe
->filename
) == 0)
1041 /* We found a match. But there might be several source files
1042 (from different directories) with the same name. */
1043 if (0 == maybe
->found
)
1045 questionable
= maybe
; /* Might use it later. */
1049 if (maybe
== 0 && questionable
!= 0)
1051 complaint (&symfile_complaints
,
1052 _("elf/stab section information questionable for %s"),
1054 maybe
= questionable
;
1059 /* Found it! Allocate a new psymtab struct, and fill it in. */
1061 pst
->section_offsets
= (struct section_offsets
*)
1062 obstack_alloc (&objfile
->objfile_obstack
,
1063 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1064 for (i
= 0; i
< maybe
->num_sections
; i
++)
1065 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1069 /* We were unable to find any offsets for this file. Complain. */
1070 if (dbx
->stab_section_info
) /* If there *is* any info, */
1071 complaint (&symfile_complaints
,
1072 _("elf/stab section information missing for %s"), filename
);
1075 /* Register that we are able to handle ELF object file formats. */
1077 static const struct sym_fns elf_sym_fns
=
1079 bfd_target_elf_flavour
,
1080 elf_new_init
, /* init anything gbl to entire symtab */
1081 elf_symfile_init
, /* read initial info, setup for sym_read() */
1082 elf_symfile_read
, /* read a symbol file into symtab */
1083 NULL
, /* sym_read_psymbols */
1084 elf_symfile_finish
, /* finished with file, cleanup */
1085 default_symfile_offsets
, /* Translate ext. to int. relocation */
1086 elf_symfile_segments
, /* Get segment information from a file. */
1088 default_symfile_relocate
, /* Relocate a debug section. */
1092 /* The same as elf_sym_fns, but not registered and lazily reads
1095 static const struct sym_fns elf_sym_fns_lazy_psyms
=
1097 bfd_target_elf_flavour
,
1098 elf_new_init
, /* init anything gbl to entire symtab */
1099 elf_symfile_init
, /* read initial info, setup for sym_read() */
1100 elf_symfile_read
, /* read a symbol file into symtab */
1101 read_psyms
, /* sym_read_psymbols */
1102 elf_symfile_finish
, /* finished with file, cleanup */
1103 default_symfile_offsets
, /* Translate ext. to int. relocation */
1104 elf_symfile_segments
, /* Get segment information from a file. */
1106 default_symfile_relocate
, /* Relocate a debug section. */
1110 /* The same as elf_sym_fns, but not registered and uses the
1111 DWARF-specific GNU index rather than psymtab. */
1112 static const struct sym_fns elf_sym_fns_gdb_index
=
1114 bfd_target_elf_flavour
,
1115 elf_new_init
, /* init anything gbl to entire symab */
1116 elf_symfile_init
, /* read initial info, setup for sym_red() */
1117 elf_symfile_read
, /* read a symbol file into symtab */
1118 NULL
, /* sym_read_psymbols */
1119 elf_symfile_finish
, /* finished with file, cleanup */
1120 default_symfile_offsets
, /* Translate ext. to int. relocatin */
1121 elf_symfile_segments
, /* Get segment information from a file. */
1123 default_symfile_relocate
, /* Relocate a debug section. */
1124 &dwarf2_gdb_index_functions
1128 _initialize_elfread (void)
1130 add_symtab_fns (&elf_sym_fns
);