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 declarations. */
44 static const struct sym_fns elf_sym_fns_gdb_index
;
45 static const struct sym_fns elf_sym_fns_lazy_psyms
;
47 /* The struct elfinfo is available only during ELF symbol table and
48 psymtab reading. It is destroyed at the completion of psymtab-reading.
49 It's local to elf_symfile_read. */
53 asection
*stabsect
; /* Section pointer for .stab section */
54 asection
*stabindexsect
; /* Section pointer for .stab.index section */
55 asection
*mdebugsect
; /* Section pointer for .mdebug section */
58 static void free_elfinfo (void *);
60 /* Locate the segments in ABFD. */
62 static struct symfile_segment_data
*
63 elf_symfile_segments (bfd
*abfd
)
65 Elf_Internal_Phdr
*phdrs
, **segments
;
67 int num_phdrs
, num_segments
, num_sections
, i
;
69 struct symfile_segment_data
*data
;
71 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
75 phdrs
= alloca (phdrs_size
);
76 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
81 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
82 for (i
= 0; i
< num_phdrs
; i
++)
83 if (phdrs
[i
].p_type
== PT_LOAD
)
84 segments
[num_segments
++] = &phdrs
[i
];
86 if (num_segments
== 0)
89 data
= XZALLOC (struct symfile_segment_data
);
90 data
->num_segments
= num_segments
;
91 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
92 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
94 for (i
= 0; i
< num_segments
; i
++)
96 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
97 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
100 num_sections
= bfd_count_sections (abfd
);
101 data
->segment_info
= XCALLOC (num_sections
, int);
103 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
108 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
111 vma
= bfd_get_section_vma (abfd
, sect
);
113 for (j
= 0; j
< num_segments
; j
++)
114 if (segments
[j
]->p_memsz
> 0
115 && vma
>= segments
[j
]->p_vaddr
116 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
118 data
->segment_info
[i
] = j
+ 1;
122 /* We should have found a segment for every non-empty section.
123 If we haven't, we will not relocate this section by any
124 offsets we apply to the segments. As an exception, do not
125 warn about SHT_NOBITS sections; in normal ELF execution
126 environments, SHT_NOBITS means zero-initialized and belongs
127 in a segment, but in no-OS environments some tools (e.g. ARM
128 RealView) use SHT_NOBITS for uninitialized data. Since it is
129 uninitialized, it doesn't need a program header. Such
130 binaries are not relocatable. */
131 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
132 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
133 warning (_("Loadable segment \"%s\" outside of ELF segments"),
134 bfd_section_name (abfd
, sect
));
140 /* We are called once per section from elf_symfile_read. We
141 need to examine each section we are passed, check to see
142 if it is something we are interested in processing, and
143 if so, stash away some access information for the section.
145 For now we recognize the dwarf debug information sections and
146 line number sections from matching their section names. The
147 ELF definition is no real help here since it has no direct
148 knowledge of DWARF (by design, so any debugging format can be
151 We also recognize the ".stab" sections used by the Sun compilers
152 released with Solaris 2.
154 FIXME: The section names should not be hardwired strings (what
155 should they be? I don't think most object file formats have enough
156 section flags to specify what kind of debug section it is.
160 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
164 ei
= (struct elfinfo
*) eip
;
165 if (strcmp (sectp
->name
, ".stab") == 0)
167 ei
->stabsect
= sectp
;
169 else if (strcmp (sectp
->name
, ".stab.index") == 0)
171 ei
->stabindexsect
= sectp
;
173 else if (strcmp (sectp
->name
, ".mdebug") == 0)
175 ei
->mdebugsect
= sectp
;
179 static struct minimal_symbol
*
180 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
182 enum minimal_symbol_type ms_type
,
183 asection
*bfd_section
, struct objfile
*objfile
)
185 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
187 if (ms_type
== mst_text
|| ms_type
== mst_file_text
)
188 address
= gdbarch_smash_text_address (gdbarch
, address
);
190 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
191 ms_type
, bfd_section
->index
,
192 bfd_section
, objfile
);
199 elf_symtab_read -- read the symbol table of an ELF file
203 void elf_symtab_read (struct objfile *objfile, int type,
204 long number_of_symbols, asymbol **symbol_table)
208 Given an objfile, a symbol table, and a flag indicating whether the
209 symbol table contains regular, dynamic, or synthetic symbols, add all
210 the global function and data symbols to the minimal symbol table.
212 In stabs-in-ELF, as implemented by Sun, there are some local symbols
213 defined in the ELF symbol table, which can be used to locate
214 the beginnings of sections from each ".o" file that was linked to
215 form the executable objfile. We gather any such info and record it
216 in data structures hung off the objfile's private data.
222 #define ST_SYNTHETIC 2
225 elf_symtab_read (struct objfile
*objfile
, int type
,
226 long number_of_symbols
, asymbol
**symbol_table
,
229 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
234 enum minimal_symbol_type ms_type
;
235 /* If sectinfo is nonNULL, it contains section info that should end up
236 filed in the objfile. */
237 struct stab_section_info
*sectinfo
= NULL
;
238 /* If filesym is nonzero, it points to a file symbol, but we haven't
239 seen any section info for it yet. */
240 asymbol
*filesym
= 0;
241 /* Name of filesym. This is either a constant string or is saved on
242 the objfile's obstack. */
243 char *filesymname
= "";
244 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
245 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
246 struct cleanup
*back_to
= make_cleanup (null_cleanup
, NULL
);
248 for (i
= 0; i
< number_of_symbols
; i
++)
250 sym
= symbol_table
[i
];
251 if (sym
->name
== NULL
|| *sym
->name
== '\0')
253 /* Skip names that don't exist (shouldn't happen), or names
254 that are null strings (may happen). */
258 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
259 symbols which do not correspond to objects in the symbol table,
260 but have some other target-specific meaning. */
261 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
263 if (gdbarch_record_special_symbol_p (gdbarch
))
264 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
268 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
269 if (type
== ST_DYNAMIC
270 && sym
->section
== &bfd_und_section
271 && (sym
->flags
& BSF_FUNCTION
))
273 struct minimal_symbol
*msym
;
274 bfd
*abfd
= objfile
->obfd
;
277 /* Symbol is a reference to a function defined in
279 If its value is non zero then it is usually the address
280 of the corresponding entry in the procedure linkage table,
281 plus the desired section offset.
282 If its value is zero then the dynamic linker has to resolve
283 the symbol. We are unable to find any meaningful address
284 for this symbol in the executable file, so we skip it. */
285 symaddr
= sym
->value
;
289 /* sym->section is the undefined section. However, we want to
290 record the section where the PLT stub resides with the
291 minimal symbol. Search the section table for the one that
292 covers the stub's address. */
293 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
295 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
298 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
299 && symaddr
< bfd_get_section_vma (abfd
, sect
)
300 + bfd_get_section_size (sect
))
306 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
308 msym
= record_minimal_symbol
309 (sym
->name
, strlen (sym
->name
), copy_names
,
310 symaddr
, mst_solib_trampoline
, sect
, objfile
);
312 msym
->filename
= filesymname
;
316 /* If it is a nonstripped executable, do not enter dynamic
317 symbols, as the dynamic symbol table is usually a subset
318 of the main symbol table. */
319 if (type
== ST_DYNAMIC
&& !stripped
)
321 if (sym
->flags
& BSF_FILE
)
323 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
324 Chain any old one onto the objfile; remember new sym. */
325 if (sectinfo
!= NULL
)
327 sectinfo
->next
= dbx
->stab_section_info
;
328 dbx
->stab_section_info
= sectinfo
;
333 obsavestring ((char *) filesym
->name
, strlen (filesym
->name
),
334 &objfile
->objfile_obstack
);
336 else if (sym
->flags
& BSF_SECTION_SYM
)
338 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
340 struct minimal_symbol
*msym
;
342 /* Select global/local/weak symbols. Note that bfd puts abs
343 symbols in their own section, so all symbols we are
344 interested in will have a section. */
345 /* Bfd symbols are section relative. */
346 symaddr
= sym
->value
+ sym
->section
->vma
;
347 /* Relocate all non-absolute and non-TLS symbols by the
349 if (sym
->section
!= &bfd_abs_section
350 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
354 /* For non-absolute symbols, use the type of the section
355 they are relative to, to intuit text/data. Bfd provides
356 no way of figuring this out for absolute symbols. */
357 if (sym
->section
== &bfd_abs_section
)
359 /* This is a hack to get the minimal symbol type
360 right for Irix 5, which has absolute addresses
361 with special section indices for dynamic symbols.
363 NOTE: uweigand-20071112: Synthetic symbols do not
364 have an ELF-private part, so do not touch those. */
365 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
366 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
376 case SHN_MIPS_ACOMMON
:
383 /* If it is an Irix dynamic symbol, skip section name
384 symbols, relocate all others by section offset. */
385 if (ms_type
!= mst_abs
)
387 if (sym
->name
[0] == '.')
392 else if (sym
->section
->flags
& SEC_CODE
)
394 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
398 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L')
399 || ((sym
->flags
& BSF_LOCAL
)
400 && sym
->name
[0] == '$'
401 && sym
->name
[1] == 'L'))
402 /* Looks like a compiler-generated label. Skip
403 it. The assembler should be skipping these (to
404 keep executables small), but apparently with
405 gcc on the (deleted) delta m88k SVR4, it loses.
406 So to have us check too should be harmless (but
407 I encourage people to fix this in the assembler
408 instead of adding checks here). */
412 ms_type
= mst_file_text
;
415 else if (sym
->section
->flags
& SEC_ALLOC
)
417 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
419 if (sym
->section
->flags
& SEC_LOAD
)
428 else if (sym
->flags
& BSF_LOCAL
)
430 /* Named Local variable in a Data section.
431 Check its name for stabs-in-elf. */
432 int special_local_sect
;
434 if (strcmp ("Bbss.bss", sym
->name
) == 0)
435 special_local_sect
= SECT_OFF_BSS (objfile
);
436 else if (strcmp ("Ddata.data", sym
->name
) == 0)
437 special_local_sect
= SECT_OFF_DATA (objfile
);
438 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
439 special_local_sect
= SECT_OFF_RODATA (objfile
);
441 special_local_sect
= -1;
442 if (special_local_sect
>= 0)
444 /* Found a special local symbol. Allocate a
445 sectinfo, if needed, and fill it in. */
446 if (sectinfo
== NULL
)
451 max_index
= SECT_OFF_BSS (objfile
);
452 if (objfile
->sect_index_data
> max_index
)
453 max_index
= objfile
->sect_index_data
;
454 if (objfile
->sect_index_rodata
> max_index
)
455 max_index
= objfile
->sect_index_rodata
;
457 /* max_index is the largest index we'll
458 use into this array, so we must
459 allocate max_index+1 elements for it.
460 However, 'struct stab_section_info'
461 already includes one element, so we
462 need to allocate max_index aadditional
464 size
= (sizeof (struct stab_section_info
)
465 + (sizeof (CORE_ADDR
) * max_index
));
466 sectinfo
= (struct stab_section_info
*)
468 make_cleanup (xfree
, sectinfo
);
469 memset (sectinfo
, 0, size
);
470 sectinfo
->num_sections
= max_index
;
473 complaint (&symfile_complaints
,
474 _("elf/stab section information %s "
475 "without a preceding file symbol"),
481 (char *) filesym
->name
;
484 if (sectinfo
->sections
[special_local_sect
] != 0)
485 complaint (&symfile_complaints
,
486 _("duplicated elf/stab section "
487 "information for %s"),
489 /* BFD symbols are section relative. */
490 symaddr
= sym
->value
+ sym
->section
->vma
;
491 /* Relocate non-absolute symbols by the
493 if (sym
->section
!= &bfd_abs_section
)
495 sectinfo
->sections
[special_local_sect
] = symaddr
;
496 /* The special local symbols don't go in the
497 minimal symbol table, so ignore this one. */
500 /* Not a special stabs-in-elf symbol, do regular
501 symbol processing. */
502 if (sym
->section
->flags
& SEC_LOAD
)
504 ms_type
= mst_file_data
;
508 ms_type
= mst_file_bss
;
513 ms_type
= mst_unknown
;
518 /* FIXME: Solaris2 shared libraries include lots of
519 odd "absolute" and "undefined" symbols, that play
520 hob with actions like finding what function the PC
521 is in. Ignore them if they aren't text, data, or bss. */
522 /* ms_type = mst_unknown; */
523 continue; /* Skip this symbol. */
525 msym
= record_minimal_symbol
526 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
527 ms_type
, sym
->section
, objfile
);
531 /* Pass symbol size field in via BFD. FIXME!!! */
532 elf_symbol_type
*elf_sym
;
534 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
535 ELF-private part. However, in some cases (e.g. synthetic
536 'dot' symbols on ppc64) the udata.p entry is set to point back
537 to the original ELF symbol it was derived from. Get the size
539 if (type
!= ST_SYNTHETIC
)
540 elf_sym
= (elf_symbol_type
*) sym
;
542 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
545 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
547 msym
->filename
= filesymname
;
548 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
551 /* For @plt symbols, also record a trampoline to the
552 destination symbol. The @plt symbol will be used in
553 disassembly, and the trampoline will be used when we are
554 trying to find the target. */
555 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
557 int len
= strlen (sym
->name
);
559 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
561 struct minimal_symbol
*mtramp
;
563 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
565 mst_solib_trampoline
,
566 sym
->section
, objfile
);
569 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
570 mtramp
->filename
= filesymname
;
571 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
577 do_cleanups (back_to
);
586 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
588 static struct build_id
*
589 build_id_bfd_get (bfd
*abfd
)
591 struct build_id
*retval
;
593 if (!bfd_check_format (abfd
, bfd_object
)
594 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
595 || elf_tdata (abfd
)->build_id
== NULL
)
598 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
599 retval
->size
= elf_tdata (abfd
)->build_id_size
;
600 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
605 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
608 build_id_verify (const char *filename
, struct build_id
*check
)
611 struct build_id
*found
= NULL
;
614 /* We expect to be silent on the non-existing files. */
615 abfd
= bfd_open_maybe_remote (filename
);
619 found
= build_id_bfd_get (abfd
);
622 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
623 else if (found
->size
!= check
->size
624 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
625 warning (_("File \"%s\" has a different build-id, file skipped"),
630 gdb_bfd_close_or_warn (abfd
);
638 build_id_to_debug_filename (struct build_id
*build_id
)
640 char *link
, *debugdir
, *retval
= NULL
;
642 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
643 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
644 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
646 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
647 cause "/.build-id/..." lookups. */
649 debugdir
= debug_file_directory
;
652 char *s
, *debugdir_end
;
653 gdb_byte
*data
= build_id
->data
;
654 size_t size
= build_id
->size
;
656 while (*debugdir
== DIRNAME_SEPARATOR
)
659 debugdir_end
= strchr (debugdir
, DIRNAME_SEPARATOR
);
660 if (debugdir_end
== NULL
)
661 debugdir_end
= &debugdir
[strlen (debugdir
)];
663 memcpy (link
, debugdir
, debugdir_end
- debugdir
);
664 s
= &link
[debugdir_end
- debugdir
];
665 s
+= sprintf (s
, "/.build-id/");
669 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
674 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
675 strcpy (s
, ".debug");
677 /* lrealpath() is expensive even for the usually non-existent files. */
678 if (access (link
, F_OK
) == 0)
679 retval
= lrealpath (link
);
681 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
690 debugdir
= debugdir_end
;
692 while (*debugdir
!= 0);
698 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
700 struct build_id
*build_id
;
702 build_id
= build_id_bfd_get (objfile
->obfd
);
703 if (build_id
!= NULL
)
707 build_id_name
= build_id_to_debug_filename (build_id
);
709 /* Prevent looping on a stripped .debug file. */
710 if (build_id_name
!= NULL
&& strcmp (build_id_name
, objfile
->name
) == 0)
712 warning (_("\"%s\": separate debug info file has no debug info"),
714 xfree (build_id_name
);
716 else if (build_id_name
!= NULL
)
717 return build_id_name
;
722 /* Scan and build partial symbols for a symbol file.
723 We have been initialized by a call to elf_symfile_init, which
724 currently does nothing.
726 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
727 in each section. We simplify it down to a single offset for all
730 This function only does the minimum work necessary for letting the
731 user "name" things symbolically; it does not read the entire symtab.
732 Instead, it reads the external and static symbols and puts them in partial
733 symbol tables. When more extensive information is requested of a
734 file, the corresponding partial symbol table is mutated into a full
735 fledged symbol table by going back and reading the symbols
738 We look for sections with specific names, to tell us what debug
739 format to look for: FIXME!!!
741 elfstab_build_psymtabs() handles STABS symbols;
742 mdebug_build_psymtabs() handles ECOFF debugging information.
744 Note that ELF files have a "minimal" symbol table, which looks a lot
745 like a COFF symbol table, but has only the minimal information necessary
746 for linking. We process this also, and use the information to
747 build gdb's minimal symbol table. This gives us some minimal debugging
748 capability even for files compiled without -g. */
751 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
753 bfd
*abfd
= objfile
->obfd
;
755 struct cleanup
*back_to
;
756 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
757 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
760 init_minimal_symbol_collection ();
761 back_to
= make_cleanup_discard_minimal_symbols ();
763 memset ((char *) &ei
, 0, sizeof (ei
));
765 /* Allocate struct to keep track of the symfile. */
766 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
767 xmalloc (sizeof (struct dbx_symfile_info
));
768 memset ((char *) objfile
->deprecated_sym_stab_info
,
769 0, sizeof (struct dbx_symfile_info
));
770 make_cleanup (free_elfinfo
, (void *) objfile
);
772 /* Process the normal ELF symbol table first. This may write some
773 chain of info into the dbx_symfile_info in
774 objfile->deprecated_sym_stab_info, which can later be used by
775 elfstab_offset_sections. */
777 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
778 if (storage_needed
< 0)
779 error (_("Can't read symbols from %s: %s"),
780 bfd_get_filename (objfile
->obfd
),
781 bfd_errmsg (bfd_get_error ()));
783 if (storage_needed
> 0)
785 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
786 make_cleanup (xfree
, symbol_table
);
787 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
790 error (_("Can't read symbols from %s: %s"),
791 bfd_get_filename (objfile
->obfd
),
792 bfd_errmsg (bfd_get_error ()));
794 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
797 /* Add the dynamic symbols. */
799 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
801 if (storage_needed
> 0)
803 /* Memory gets permanently referenced from ABFD after
804 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
805 It happens only in the case when elf_slurp_reloc_table sees
806 asection->relocation NULL. Determining which section is asection is
807 done by _bfd_elf_get_synthetic_symtab which is all a bfd
808 implementation detail, though. */
810 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
811 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
815 error (_("Can't read symbols from %s: %s"),
816 bfd_get_filename (objfile
->obfd
),
817 bfd_errmsg (bfd_get_error ()));
819 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
822 /* Add synthetic symbols - for instance, names for any PLT entries. */
824 synthcount
= bfd_get_synthetic_symtab (abfd
, symcount
, symbol_table
,
825 dynsymcount
, dyn_symbol_table
,
829 asymbol
**synth_symbol_table
;
832 make_cleanup (xfree
, synthsyms
);
833 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
834 for (i
= 0; i
< synthcount
; i
++)
835 synth_symbol_table
[i
] = synthsyms
+ i
;
836 make_cleanup (xfree
, synth_symbol_table
);
837 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
838 synth_symbol_table
, 1);
841 /* Install any minimal symbols that have been collected as the current
842 minimal symbols for this objfile. The debug readers below this point
843 should not generate new minimal symbols; if they do it's their
844 responsibility to install them. "mdebug" appears to be the only one
845 which will do this. */
847 install_minimal_symbols (objfile
);
848 do_cleanups (back_to
);
850 /* Now process debugging information, which is contained in
851 special ELF sections. */
853 /* We first have to find them... */
854 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
856 /* ELF debugging information is inserted into the psymtab in the
857 order of least informative first - most informative last. Since
858 the psymtab table is searched `most recent insertion first' this
859 increases the probability that more detailed debug information
860 for a section is found.
862 For instance, an object file might contain both .mdebug (XCOFF)
863 and .debug_info (DWARF2) sections then .mdebug is inserted first
864 (searched last) and DWARF2 is inserted last (searched first). If
865 we don't do this then the XCOFF info is found first - for code in
866 an included file XCOFF info is useless. */
870 const struct ecoff_debug_swap
*swap
;
872 /* .mdebug section, presumably holding ECOFF debugging
874 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
876 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
882 /* Stab sections have an associated string table that looks like
883 a separate section. */
884 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
886 /* FIXME should probably warn about a stab section without a stabstr. */
888 elfstab_build_psymtabs (objfile
,
891 bfd_section_size (abfd
, str_sect
));
894 if (dwarf2_has_info (objfile
))
896 if (dwarf2_initialize_objfile (objfile
))
897 objfile
->sf
= &elf_sym_fns_gdb_index
;
900 /* It is ok to do this even if the stabs reader made some
901 partial symbols, because OBJF_PSYMTABS_READ has not been
902 set, and so our lazy reader function will still be called
904 objfile
->sf
= &elf_sym_fns_lazy_psyms
;
907 /* If the file has its own symbol tables it has no separate debug
908 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
909 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
910 `.note.gnu.build-id'. */
911 else if (!objfile_has_partial_symbols (objfile
))
915 debugfile
= find_separate_debug_file_by_buildid (objfile
);
917 if (debugfile
== NULL
)
918 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
922 bfd
*abfd
= symfile_bfd_open (debugfile
);
924 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
930 /* Callback to lazily read psymtabs. */
933 read_psyms (struct objfile
*objfile
)
935 if (dwarf2_has_info (objfile
))
936 dwarf2_build_psymtabs (objfile
);
939 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
940 the chain of stab_section_info's, that might be dangling from
944 free_elfinfo (void *objp
)
946 struct objfile
*objfile
= (struct objfile
*) objp
;
947 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
948 struct stab_section_info
*ssi
, *nssi
;
950 ssi
= dbxinfo
->stab_section_info
;
958 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
962 /* Initialize anything that needs initializing when a completely new symbol
963 file is specified (not just adding some symbols from another file, e.g. a
966 We reinitialize buildsym, since we may be reading stabs from an ELF
970 elf_new_init (struct objfile
*ignore
)
972 stabsread_new_init ();
973 buildsym_new_init ();
976 /* Perform any local cleanups required when we are done with a particular
977 objfile. I.E, we are in the process of discarding all symbol information
978 for an objfile, freeing up all memory held for it, and unlinking the
979 objfile struct from the global list of known objfiles. */
982 elf_symfile_finish (struct objfile
*objfile
)
984 if (objfile
->deprecated_sym_stab_info
!= NULL
)
986 xfree (objfile
->deprecated_sym_stab_info
);
989 dwarf2_free_objfile (objfile
);
992 /* ELF specific initialization routine for reading symbols.
994 It is passed a pointer to a struct sym_fns which contains, among other
995 things, the BFD for the file whose symbols are being read, and a slot for
996 a pointer to "private data" which we can fill with goodies.
998 For now at least, we have nothing in particular to do, so this function is
1002 elf_symfile_init (struct objfile
*objfile
)
1004 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1005 find this causes a significant slowdown in gdb then we could
1006 set it in the debug symbol readers only when necessary. */
1007 objfile
->flags
|= OBJF_REORDERED
;
1010 /* When handling an ELF file that contains Sun STABS debug info,
1011 some of the debug info is relative to the particular chunk of the
1012 section that was generated in its individual .o file. E.g.
1013 offsets to static variables are relative to the start of the data
1014 segment *for that module before linking*. This information is
1015 painfully squirreled away in the ELF symbol table as local symbols
1016 with wierd names. Go get 'em when needed. */
1019 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
1021 const char *filename
= pst
->filename
;
1022 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
1023 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1024 struct stab_section_info
*questionable
= 0;
1028 /* The ELF symbol info doesn't include path names, so strip the path
1029 (if any) from the psymtab filename. */
1030 while (0 != (p
= strchr (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 && strcmp (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
);