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
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 /* The struct elfinfo is available only during ELF symbol table and
44 psymtab reading. It is destroyed at the completion of psymtab-reading.
45 It's local to elf_symfile_read. */
49 asection
*stabsect
; /* Section pointer for .stab section */
50 asection
*stabindexsect
; /* Section pointer for .stab.index section */
51 asection
*mdebugsect
; /* Section pointer for .mdebug section */
54 static void free_elfinfo (void *);
56 /* Locate the segments in ABFD. */
58 static struct symfile_segment_data
*
59 elf_symfile_segments (bfd
*abfd
)
61 Elf_Internal_Phdr
*phdrs
, **segments
;
63 int num_phdrs
, num_segments
, num_sections
, i
;
65 struct symfile_segment_data
*data
;
67 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
71 phdrs
= alloca (phdrs_size
);
72 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
77 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
78 for (i
= 0; i
< num_phdrs
; i
++)
79 if (phdrs
[i
].p_type
== PT_LOAD
)
80 segments
[num_segments
++] = &phdrs
[i
];
82 if (num_segments
== 0)
85 data
= XZALLOC (struct symfile_segment_data
);
86 data
->num_segments
= num_segments
;
87 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
88 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
90 for (i
= 0; i
< num_segments
; i
++)
92 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
93 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
96 num_sections
= bfd_count_sections (abfd
);
97 data
->segment_info
= XCALLOC (num_sections
, int);
99 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
104 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
107 vma
= bfd_get_section_vma (abfd
, sect
);
109 for (j
= 0; j
< num_segments
; j
++)
110 if (segments
[j
]->p_memsz
> 0
111 && vma
>= segments
[j
]->p_vaddr
112 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
114 data
->segment_info
[i
] = j
+ 1;
118 /* We should have found a segment for every non-empty section.
119 If we haven't, we will not relocate this section by any
120 offsets we apply to the segments. As an exception, do not
121 warn about SHT_NOBITS sections; in normal ELF execution
122 environments, SHT_NOBITS means zero-initialized and belongs
123 in a segment, but in no-OS environments some tools (e.g. ARM
124 RealView) use SHT_NOBITS for uninitialized data. Since it is
125 uninitialized, it doesn't need a program header. Such
126 binaries are not relocatable. */
127 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
128 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
129 warning (_("Loadable segment \"%s\" outside of ELF segments"),
130 bfd_section_name (abfd
, sect
));
136 /* We are called once per section from elf_symfile_read. We
137 need to examine each section we are passed, check to see
138 if it is something we are interested in processing, and
139 if so, stash away some access information for the section.
141 For now we recognize the dwarf debug information sections and
142 line number sections from matching their section names. The
143 ELF definition is no real help here since it has no direct
144 knowledge of DWARF (by design, so any debugging format can be
147 We also recognize the ".stab" sections used by the Sun compilers
148 released with Solaris 2.
150 FIXME: The section names should not be hardwired strings (what
151 should they be? I don't think most object file formats have enough
152 section flags to specify what kind of debug section it is
156 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
160 ei
= (struct elfinfo
*) eip
;
161 if (strcmp (sectp
->name
, ".stab") == 0)
163 ei
->stabsect
= sectp
;
165 else if (strcmp (sectp
->name
, ".stab.index") == 0)
167 ei
->stabindexsect
= sectp
;
169 else if (strcmp (sectp
->name
, ".mdebug") == 0)
171 ei
->mdebugsect
= sectp
;
175 static struct minimal_symbol
*
176 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
178 enum minimal_symbol_type ms_type
,
179 asection
*bfd_section
, struct objfile
*objfile
)
181 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
183 if (ms_type
== mst_text
|| ms_type
== mst_file_text
)
184 address
= gdbarch_smash_text_address (gdbarch
, address
);
186 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
187 ms_type
, bfd_section
->index
,
188 bfd_section
, objfile
);
195 elf_symtab_read -- read the symbol table of an ELF file
199 void elf_symtab_read (struct objfile *objfile, int type,
200 long number_of_symbols, asymbol **symbol_table)
204 Given an objfile, a symbol table, and a flag indicating whether the
205 symbol table contains regular, dynamic, or synthetic symbols, add all
206 the global function and data symbols to the minimal symbol table.
208 In stabs-in-ELF, as implemented by Sun, there are some local symbols
209 defined in the ELF symbol table, which can be used to locate
210 the beginnings of sections from each ".o" file that was linked to
211 form the executable objfile. We gather any such info and record it
212 in data structures hung off the objfile's private data.
218 #define ST_SYNTHETIC 2
221 elf_symtab_read (struct objfile
*objfile
, int type
,
222 long number_of_symbols
, asymbol
**symbol_table
,
225 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
231 enum minimal_symbol_type ms_type
;
232 /* If sectinfo is nonNULL, it contains section info that should end up
233 filed in the objfile. */
234 struct stab_section_info
*sectinfo
= NULL
;
235 /* If filesym is nonzero, it points to a file symbol, but we haven't
236 seen any section info for it yet. */
237 asymbol
*filesym
= 0;
238 /* Name of filesym. This is either a constant string or is saved on
239 the objfile's obstack. */
240 char *filesymname
= "";
241 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
242 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
244 for (i
= 0; i
< number_of_symbols
; i
++)
246 sym
= symbol_table
[i
];
247 if (sym
->name
== NULL
|| *sym
->name
== '\0')
249 /* Skip names that don't exist (shouldn't happen), or names
250 that are null strings (may happen). */
254 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
255 symbols which do not correspond to objects in the symbol table,
256 but have some other target-specific meaning. */
257 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
259 if (gdbarch_record_special_symbol_p (gdbarch
))
260 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
264 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
265 if (type
== ST_DYNAMIC
266 && sym
->section
== &bfd_und_section
267 && (sym
->flags
& BSF_FUNCTION
))
269 struct minimal_symbol
*msym
;
270 bfd
*abfd
= objfile
->obfd
;
273 /* Symbol is a reference to a function defined in
275 If its value is non zero then it is usually the address
276 of the corresponding entry in the procedure linkage table,
277 plus the desired section offset.
278 If its value is zero then the dynamic linker has to resolve
279 the symbol. We are unable to find any meaningful address
280 for this symbol in the executable file, so we skip it. */
281 symaddr
= sym
->value
;
285 /* sym->section is the undefined section. However, we want to
286 record the section where the PLT stub resides with the
287 minimal symbol. Search the section table for the one that
288 covers the stub's address. */
289 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
291 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
294 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
295 && symaddr
< bfd_get_section_vma (abfd
, sect
)
296 + bfd_get_section_size (sect
))
302 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
304 msym
= record_minimal_symbol
305 (sym
->name
, strlen (sym
->name
), copy_names
,
306 symaddr
, mst_solib_trampoline
, sect
, objfile
);
308 msym
->filename
= filesymname
;
312 /* If it is a nonstripped executable, do not enter dynamic
313 symbols, as the dynamic symbol table is usually a subset
314 of the main symbol table. */
315 if (type
== ST_DYNAMIC
&& !stripped
)
317 if (sym
->flags
& BSF_FILE
)
319 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
320 Chain any old one onto the objfile; remember new sym. */
321 if (sectinfo
!= NULL
)
323 sectinfo
->next
= dbx
->stab_section_info
;
324 dbx
->stab_section_info
= sectinfo
;
329 obsavestring ((char *) filesym
->name
, strlen (filesym
->name
),
330 &objfile
->objfile_obstack
);
332 else if (sym
->flags
& BSF_SECTION_SYM
)
334 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
336 struct minimal_symbol
*msym
;
338 /* Select global/local/weak symbols. Note that bfd puts abs
339 symbols in their own section, so all symbols we are
340 interested in will have a section. */
341 /* Bfd symbols are section relative. */
342 symaddr
= sym
->value
+ sym
->section
->vma
;
343 /* Relocate all non-absolute and non-TLS symbols by the
345 if (sym
->section
!= &bfd_abs_section
346 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
350 /* For non-absolute symbols, use the type of the section
351 they are relative to, to intuit text/data. Bfd provides
352 no way of figuring this out for absolute symbols. */
353 if (sym
->section
== &bfd_abs_section
)
355 /* This is a hack to get the minimal symbol type
356 right for Irix 5, which has absolute addresses
357 with special section indices for dynamic symbols.
359 NOTE: uweigand-20071112: Synthetic symbols do not
360 have an ELF-private part, so do not touch those. */
361 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
362 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
372 case SHN_MIPS_ACOMMON
:
379 /* If it is an Irix dynamic symbol, skip section name
380 symbols, relocate all others by section offset. */
381 if (ms_type
!= mst_abs
)
383 if (sym
->name
[0] == '.')
388 else if (sym
->section
->flags
& SEC_CODE
)
390 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
394 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L')
395 || ((sym
->flags
& BSF_LOCAL
)
396 && sym
->name
[0] == '$'
397 && sym
->name
[1] == 'L'))
398 /* Looks like a compiler-generated label. Skip
399 it. The assembler should be skipping these (to
400 keep executables small), but apparently with
401 gcc on the (deleted) delta m88k SVR4, it loses.
402 So to have us check too should be harmless (but
403 I encourage people to fix this in the assembler
404 instead of adding checks here). */
408 ms_type
= mst_file_text
;
411 else if (sym
->section
->flags
& SEC_ALLOC
)
413 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
415 if (sym
->section
->flags
& SEC_LOAD
)
424 else if (sym
->flags
& BSF_LOCAL
)
426 /* Named Local variable in a Data section.
427 Check its name for stabs-in-elf. */
428 int special_local_sect
;
429 if (strcmp ("Bbss.bss", sym
->name
) == 0)
430 special_local_sect
= SECT_OFF_BSS (objfile
);
431 else if (strcmp ("Ddata.data", sym
->name
) == 0)
432 special_local_sect
= SECT_OFF_DATA (objfile
);
433 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
434 special_local_sect
= SECT_OFF_RODATA (objfile
);
436 special_local_sect
= -1;
437 if (special_local_sect
>= 0)
439 /* Found a special local symbol. Allocate a
440 sectinfo, if needed, and fill it in. */
441 if (sectinfo
== NULL
)
446 max_index
= SECT_OFF_BSS (objfile
);
447 if (objfile
->sect_index_data
> max_index
)
448 max_index
= objfile
->sect_index_data
;
449 if (objfile
->sect_index_rodata
> max_index
)
450 max_index
= objfile
->sect_index_rodata
;
452 /* max_index is the largest index we'll
453 use into this array, so we must
454 allocate max_index+1 elements for it.
455 However, 'struct stab_section_info'
456 already includes one element, so we
457 need to allocate max_index aadditional
459 size
= (sizeof (struct stab_section_info
)
460 + (sizeof (CORE_ADDR
)
462 sectinfo
= (struct stab_section_info
*)
464 memset (sectinfo
, 0, size
);
465 sectinfo
->num_sections
= max_index
;
468 complaint (&symfile_complaints
,
469 _("elf/stab section information %s without a preceding file symbol"),
475 (char *) filesym
->name
;
478 if (sectinfo
->sections
[special_local_sect
] != 0)
479 complaint (&symfile_complaints
,
480 _("duplicated elf/stab section information for %s"),
482 /* BFD symbols are section relative. */
483 symaddr
= sym
->value
+ sym
->section
->vma
;
484 /* Relocate non-absolute symbols by the
486 if (sym
->section
!= &bfd_abs_section
)
488 sectinfo
->sections
[special_local_sect
] = symaddr
;
489 /* The special local symbols don't go in the
490 minimal symbol table, so ignore this one. */
493 /* Not a special stabs-in-elf symbol, do regular
494 symbol processing. */
495 if (sym
->section
->flags
& SEC_LOAD
)
497 ms_type
= mst_file_data
;
501 ms_type
= mst_file_bss
;
506 ms_type
= mst_unknown
;
511 /* FIXME: Solaris2 shared libraries include lots of
512 odd "absolute" and "undefined" symbols, that play
513 hob with actions like finding what function the PC
514 is in. Ignore them if they aren't text, data, or bss. */
515 /* ms_type = mst_unknown; */
516 continue; /* Skip this symbol. */
518 msym
= record_minimal_symbol
519 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
520 ms_type
, sym
->section
, objfile
);
524 /* Pass symbol size field in via BFD. FIXME!!! */
525 elf_symbol_type
*elf_sym
;
527 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
528 ELF-private part. However, in some cases (e.g. synthetic
529 'dot' symbols on ppc64) the udata.p entry is set to point back
530 to the original ELF symbol it was derived from. Get the size
532 if (type
!= ST_SYNTHETIC
)
533 elf_sym
= (elf_symbol_type
*) sym
;
535 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
538 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
540 msym
->filename
= filesymname
;
541 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
544 /* For @plt symbols, also record a trampoline to the
545 destination symbol. The @plt symbol will be used in
546 disassembly, and the trampoline will be used when we are
547 trying to find the target. */
548 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
550 int len
= strlen (sym
->name
);
552 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
554 struct minimal_symbol
*mtramp
;
556 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
558 mst_solib_trampoline
,
559 sym
->section
, objfile
);
562 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
563 mtramp
->filename
= filesymname
;
564 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
578 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
580 static struct build_id
*
581 build_id_bfd_get (bfd
*abfd
)
583 struct build_id
*retval
;
585 if (!bfd_check_format (abfd
, bfd_object
)
586 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
587 || elf_tdata (abfd
)->build_id
== NULL
)
590 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
591 retval
->size
= elf_tdata (abfd
)->build_id_size
;
592 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
597 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
600 build_id_verify (const char *filename
, struct build_id
*check
)
603 struct build_id
*found
= NULL
;
606 /* We expect to be silent on the non-existing files. */
607 abfd
= bfd_open_maybe_remote (filename
);
611 found
= build_id_bfd_get (abfd
);
614 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
615 else if (found
->size
!= check
->size
616 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
617 warning (_("File \"%s\" has a different build-id, file skipped"), filename
);
621 gdb_bfd_close_or_warn (abfd
);
629 build_id_to_debug_filename (struct build_id
*build_id
)
631 char *link
, *debugdir
, *retval
= NULL
;
633 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
634 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
635 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
637 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
638 cause "/.build-id/..." lookups. */
640 debugdir
= debug_file_directory
;
643 char *s
, *debugdir_end
;
644 gdb_byte
*data
= build_id
->data
;
645 size_t size
= build_id
->size
;
647 while (*debugdir
== DIRNAME_SEPARATOR
)
650 debugdir_end
= strchr (debugdir
, DIRNAME_SEPARATOR
);
651 if (debugdir_end
== NULL
)
652 debugdir_end
= &debugdir
[strlen (debugdir
)];
654 memcpy (link
, debugdir
, debugdir_end
- debugdir
);
655 s
= &link
[debugdir_end
- debugdir
];
656 s
+= sprintf (s
, "/.build-id/");
660 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
665 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
666 strcpy (s
, ".debug");
668 /* lrealpath() is expensive even for the usually non-existent files. */
669 if (access (link
, F_OK
) == 0)
670 retval
= lrealpath (link
);
672 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
681 debugdir
= debugdir_end
;
683 while (*debugdir
!= 0);
689 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
692 char *basename
, *name_copy
, *debugdir
;
694 char *debugfile
= NULL
;
695 char *canon_name
= NULL
;
696 bfd_size_type debuglink_size
;
698 struct build_id
*build_id
;
700 build_id
= build_id_bfd_get (objfile
->obfd
);
701 if (build_id
!= NULL
)
705 build_id_name
= build_id_to_debug_filename (build_id
);
707 /* Prevent looping on a stripped .debug file. */
708 if (build_id_name
!= NULL
&& strcmp (build_id_name
, objfile
->name
) == 0)
710 warning (_("\"%s\": separate debug info file has no debug info"),
712 xfree (build_id_name
);
714 else if (build_id_name
!= NULL
)
715 return build_id_name
;
720 /* Scan and build partial symbols for a symbol file.
721 We have been initialized by a call to elf_symfile_init, which
722 currently does nothing.
724 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
725 in each section. We simplify it down to a single offset for all
728 This function only does the minimum work necessary for letting the
729 user "name" things symbolically; it does not read the entire symtab.
730 Instead, it reads the external and static symbols and puts them in partial
731 symbol tables. When more extensive information is requested of a
732 file, the corresponding partial symbol table is mutated into a full
733 fledged symbol table by going back and reading the symbols
736 We look for sections with specific names, to tell us what debug
737 format to look for: FIXME!!!
739 elfstab_build_psymtabs() handles STABS symbols;
740 mdebug_build_psymtabs() handles ECOFF debugging information.
742 Note that ELF files have a "minimal" symbol table, which looks a lot
743 like a COFF symbol table, but has only the minimal information necessary
744 for linking. We process this also, and use the information to
745 build gdb's minimal symbol table. This gives us some minimal debugging
746 capability even for files compiled without -g. */
749 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
751 bfd
*abfd
= objfile
->obfd
;
753 struct cleanup
*back_to
;
755 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
756 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
759 init_minimal_symbol_collection ();
760 back_to
= make_cleanup_discard_minimal_symbols ();
762 memset ((char *) &ei
, 0, sizeof (ei
));
764 /* Allocate struct to keep track of the symfile */
765 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
766 xmalloc (sizeof (struct dbx_symfile_info
));
767 memset ((char *) objfile
->deprecated_sym_stab_info
, 0, sizeof (struct dbx_symfile_info
));
768 make_cleanup (free_elfinfo
, (void *) objfile
);
770 /* Process the normal ELF symbol table first. This may write some
771 chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info,
772 which can later be used by 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"), bfd_get_filename (objfile
->obfd
),
777 bfd_errmsg (bfd_get_error ()));
779 if (storage_needed
> 0)
781 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
782 make_cleanup (xfree
, symbol_table
);
783 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
786 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile
->obfd
),
787 bfd_errmsg (bfd_get_error ()));
789 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
792 /* Add the dynamic symbols. */
794 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
796 if (storage_needed
> 0)
798 dyn_symbol_table
= (asymbol
**) xmalloc (storage_needed
);
799 make_cleanup (xfree
, dyn_symbol_table
);
800 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
804 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile
->obfd
),
805 bfd_errmsg (bfd_get_error ()));
807 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
810 /* Add synthetic symbols - for instance, names for any PLT entries. */
812 synthcount
= bfd_get_synthetic_symtab (abfd
, symcount
, symbol_table
,
813 dynsymcount
, dyn_symbol_table
,
817 asymbol
**synth_symbol_table
;
820 make_cleanup (xfree
, synthsyms
);
821 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
822 for (i
= 0; i
< synthcount
; i
++)
823 synth_symbol_table
[i
] = synthsyms
+ i
;
824 make_cleanup (xfree
, synth_symbol_table
);
825 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
, synth_symbol_table
, 1);
828 /* Install any minimal symbols that have been collected as the current
829 minimal symbols for this objfile. The debug readers below this point
830 should not generate new minimal symbols; if they do it's their
831 responsibility to install them. "mdebug" appears to be the only one
832 which will do this. */
834 install_minimal_symbols (objfile
);
835 do_cleanups (back_to
);
837 /* Now process debugging information, which is contained in
838 special ELF sections. */
840 /* We first have to find them... */
841 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
843 /* ELF debugging information is inserted into the psymtab in the
844 order of least informative first - most informative last. Since
845 the psymtab table is searched `most recent insertion first' this
846 increases the probability that more detailed debug information
847 for a section is found.
849 For instance, an object file might contain both .mdebug (XCOFF)
850 and .debug_info (DWARF2) sections then .mdebug is inserted first
851 (searched last) and DWARF2 is inserted last (searched first). If
852 we don't do this then the XCOFF info is found first - for code in
853 an included file XCOFF info is useless. */
857 const struct ecoff_debug_swap
*swap
;
859 /* .mdebug section, presumably holding ECOFF debugging
861 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
863 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
869 /* Stab sections have an associated string table that looks like
870 a separate section. */
871 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
873 /* FIXME should probably warn about a stab section without a stabstr. */
875 elfstab_build_psymtabs (objfile
,
878 bfd_section_size (abfd
, str_sect
));
880 if (dwarf2_has_info (objfile
))
882 /* DWARF 2 sections */
883 dwarf2_build_psymtabs (objfile
);
886 /* If the file has its own symbol tables it has no separate debug info.
887 `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to SYMTABS/PSYMTABS.
888 `.gnu_debuglink' may no longer be present with `.note.gnu.build-id'. */
889 if (!objfile_has_partial_symbols (objfile
))
893 debugfile
= find_separate_debug_file_by_buildid (objfile
);
895 if (debugfile
== NULL
)
896 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
900 bfd
*abfd
= symfile_bfd_open (debugfile
);
901 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
907 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
908 the chain of stab_section_info's, that might be dangling from
912 free_elfinfo (void *objp
)
914 struct objfile
*objfile
= (struct objfile
*) objp
;
915 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
916 struct stab_section_info
*ssi
, *nssi
;
918 ssi
= dbxinfo
->stab_section_info
;
926 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
930 /* Initialize anything that needs initializing when a completely new symbol
931 file is specified (not just adding some symbols from another file, e.g. a
934 We reinitialize buildsym, since we may be reading stabs from an ELF file. */
937 elf_new_init (struct objfile
*ignore
)
939 stabsread_new_init ();
940 buildsym_new_init ();
943 /* Perform any local cleanups required when we are done with a particular
944 objfile. I.E, we are in the process of discarding all symbol information
945 for an objfile, freeing up all memory held for it, and unlinking the
946 objfile struct from the global list of known objfiles. */
949 elf_symfile_finish (struct objfile
*objfile
)
951 if (objfile
->deprecated_sym_stab_info
!= NULL
)
953 xfree (objfile
->deprecated_sym_stab_info
);
956 dwarf2_free_objfile (objfile
);
959 /* ELF specific initialization routine for reading symbols.
961 It is passed a pointer to a struct sym_fns which contains, among other
962 things, the BFD for the file whose symbols are being read, and a slot for
963 a pointer to "private data" which we can fill with goodies.
965 For now at least, we have nothing in particular to do, so this function is
969 elf_symfile_init (struct objfile
*objfile
)
971 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
972 find this causes a significant slowdown in gdb then we could
973 set it in the debug symbol readers only when necessary. */
974 objfile
->flags
|= OBJF_REORDERED
;
977 /* When handling an ELF file that contains Sun STABS debug info,
978 some of the debug info is relative to the particular chunk of the
979 section that was generated in its individual .o file. E.g.
980 offsets to static variables are relative to the start of the data
981 segment *for that module before linking*. This information is
982 painfully squirreled away in the ELF symbol table as local symbols
983 with wierd names. Go get 'em when needed. */
986 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
988 char *filename
= pst
->filename
;
989 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
990 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
991 struct stab_section_info
*questionable
= 0;
995 /* The ELF symbol info doesn't include path names, so strip the path
996 (if any) from the psymtab filename. */
997 while (0 != (p
= strchr (filename
, '/')))
1000 /* FIXME: This linear search could speed up significantly
1001 if it was chained in the right order to match how we search it,
1002 and if we unchained when we found a match. */
1003 for (; maybe
; maybe
= maybe
->next
)
1005 if (filename
[0] == maybe
->filename
[0]
1006 && strcmp (filename
, maybe
->filename
) == 0)
1008 /* We found a match. But there might be several source files
1009 (from different directories) with the same name. */
1010 if (0 == maybe
->found
)
1012 questionable
= maybe
; /* Might use it later. */
1016 if (maybe
== 0 && questionable
!= 0)
1018 complaint (&symfile_complaints
,
1019 _("elf/stab section information questionable for %s"), filename
);
1020 maybe
= questionable
;
1025 /* Found it! Allocate a new psymtab struct, and fill it in. */
1027 pst
->section_offsets
= (struct section_offsets
*)
1028 obstack_alloc (&objfile
->objfile_obstack
,
1029 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1030 for (i
= 0; i
< maybe
->num_sections
; i
++)
1031 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1035 /* We were unable to find any offsets for this file. Complain. */
1036 if (dbx
->stab_section_info
) /* If there *is* any info, */
1037 complaint (&symfile_complaints
,
1038 _("elf/stab section information missing for %s"), filename
);
1041 /* Register that we are able to handle ELF object file formats. */
1043 static struct sym_fns elf_sym_fns
=
1045 bfd_target_elf_flavour
,
1046 elf_new_init
, /* sym_new_init: init anything gbl to entire symtab */
1047 elf_symfile_init
, /* sym_init: read initial info, setup for sym_read() */
1048 elf_symfile_read
, /* sym_read: read a symbol file into symtab */
1049 elf_symfile_finish
, /* sym_finish: finished with file, cleanup */
1050 default_symfile_offsets
, /* sym_offsets: Translate ext. to int. relocation */
1051 elf_symfile_segments
, /* sym_segments: Get segment information from
1053 NULL
, /* sym_read_linetable */
1054 default_symfile_relocate
, /* sym_relocate: Relocate a debug section. */
1056 NULL
/* next: pointer to next struct sym_fns */
1060 _initialize_elfread (void)
1062 add_symtab_fns (&elf_sym_fns
);