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"
44 #include "gdbthread.h"
47 extern void _initialize_elfread (void);
49 /* Forward declarations. */
50 static const struct sym_fns elf_sym_fns_gdb_index
;
51 static const struct sym_fns elf_sym_fns_lazy_psyms
;
53 /* The struct elfinfo is available only during ELF symbol table and
54 psymtab reading. It is destroyed at the completion of psymtab-reading.
55 It's local to elf_symfile_read. */
59 asection
*stabsect
; /* Section pointer for .stab section */
60 asection
*stabindexsect
; /* Section pointer for .stab.index section */
61 asection
*mdebugsect
; /* Section pointer for .mdebug section */
64 static void free_elfinfo (void *);
66 /* Minimal symbols located at the GOT entries for .plt - that is the real
67 pointer where the given entry will jump to. It gets updated by the real
68 function address during lazy ld.so resolving in the inferior. These
69 minimal symbols are indexed for <tab>-completion. */
71 #define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
73 /* Locate the segments in ABFD. */
75 static struct symfile_segment_data
*
76 elf_symfile_segments (bfd
*abfd
)
78 Elf_Internal_Phdr
*phdrs
, **segments
;
80 int num_phdrs
, num_segments
, num_sections
, i
;
82 struct symfile_segment_data
*data
;
84 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
88 phdrs
= alloca (phdrs_size
);
89 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
94 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
95 for (i
= 0; i
< num_phdrs
; i
++)
96 if (phdrs
[i
].p_type
== PT_LOAD
)
97 segments
[num_segments
++] = &phdrs
[i
];
99 if (num_segments
== 0)
102 data
= XZALLOC (struct symfile_segment_data
);
103 data
->num_segments
= num_segments
;
104 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
105 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
107 for (i
= 0; i
< num_segments
; i
++)
109 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
110 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
113 num_sections
= bfd_count_sections (abfd
);
114 data
->segment_info
= XCALLOC (num_sections
, int);
116 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
121 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
124 vma
= bfd_get_section_vma (abfd
, sect
);
126 for (j
= 0; j
< num_segments
; j
++)
127 if (segments
[j
]->p_memsz
> 0
128 && vma
>= segments
[j
]->p_vaddr
129 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
131 data
->segment_info
[i
] = j
+ 1;
135 /* We should have found a segment for every non-empty section.
136 If we haven't, we will not relocate this section by any
137 offsets we apply to the segments. As an exception, do not
138 warn about SHT_NOBITS sections; in normal ELF execution
139 environments, SHT_NOBITS means zero-initialized and belongs
140 in a segment, but in no-OS environments some tools (e.g. ARM
141 RealView) use SHT_NOBITS for uninitialized data. Since it is
142 uninitialized, it doesn't need a program header. Such
143 binaries are not relocatable. */
144 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
145 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
146 warning (_("Loadable segment \"%s\" outside of ELF segments"),
147 bfd_section_name (abfd
, sect
));
153 /* We are called once per section from elf_symfile_read. We
154 need to examine each section we are passed, check to see
155 if it is something we are interested in processing, and
156 if so, stash away some access information for the section.
158 For now we recognize the dwarf debug information sections and
159 line number sections from matching their section names. The
160 ELF definition is no real help here since it has no direct
161 knowledge of DWARF (by design, so any debugging format can be
164 We also recognize the ".stab" sections used by the Sun compilers
165 released with Solaris 2.
167 FIXME: The section names should not be hardwired strings (what
168 should they be? I don't think most object file formats have enough
169 section flags to specify what kind of debug section it is.
173 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
177 ei
= (struct elfinfo
*) eip
;
178 if (strcmp (sectp
->name
, ".stab") == 0)
180 ei
->stabsect
= sectp
;
182 else if (strcmp (sectp
->name
, ".stab.index") == 0)
184 ei
->stabindexsect
= sectp
;
186 else if (strcmp (sectp
->name
, ".mdebug") == 0)
188 ei
->mdebugsect
= sectp
;
192 static struct minimal_symbol
*
193 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
195 enum minimal_symbol_type ms_type
,
196 asection
*bfd_section
, struct objfile
*objfile
)
198 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
200 if (ms_type
== mst_text
|| ms_type
== mst_file_text
201 || ms_type
== mst_text_gnu_ifunc
)
202 address
= gdbarch_smash_text_address (gdbarch
, address
);
204 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
205 ms_type
, bfd_section
->index
,
206 bfd_section
, objfile
);
209 /* Read the symbol table of an ELF file.
211 Given an objfile, a symbol table, and a flag indicating whether the
212 symbol table contains regular, dynamic, or synthetic symbols, add all
213 the global function and data symbols to the minimal symbol table.
215 In stabs-in-ELF, as implemented by Sun, there are some local symbols
216 defined in the ELF symbol table, which can be used to locate
217 the beginnings of sections from each ".o" file that was linked to
218 form the executable objfile. We gather any such info and record it
219 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);
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 /* On ia64-hpux, we have discovered that the system linker
307 adds undefined symbols with nonzero addresses that cannot
308 be right (their address points inside the code of another
309 function in the .text section). This creates problems
310 when trying to determine which symbol corresponds to
313 We try to detect those buggy symbols by checking which
314 section we think they correspond to. Normally, PLT symbols
315 are stored inside their own section, and the typical name
316 for that section is ".plt". So, if there is a ".plt"
317 section, and yet the section name of our symbol does not
318 start with ".plt", we ignore that symbol. */
319 if (strncmp (sect
->name
, ".plt", 4) != 0
320 && bfd_get_section_by_name (abfd
, ".plt") != NULL
)
323 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
325 msym
= record_minimal_symbol
326 (sym
->name
, strlen (sym
->name
), copy_names
,
327 symaddr
, mst_solib_trampoline
, sect
, objfile
);
329 msym
->filename
= filesymname
;
333 /* If it is a nonstripped executable, do not enter dynamic
334 symbols, as the dynamic symbol table is usually a subset
335 of the main symbol table. */
336 if (type
== ST_DYNAMIC
&& !stripped
)
338 if (sym
->flags
& BSF_FILE
)
340 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
341 Chain any old one onto the objfile; remember new sym. */
342 if (sectinfo
!= NULL
)
344 sectinfo
->next
= dbx
->stab_section_info
;
345 dbx
->stab_section_info
= sectinfo
;
350 obsavestring ((char *) filesym
->name
, strlen (filesym
->name
),
351 &objfile
->objfile_obstack
);
353 else if (sym
->flags
& BSF_SECTION_SYM
)
355 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
357 struct minimal_symbol
*msym
;
359 /* Select global/local/weak symbols. Note that bfd puts abs
360 symbols in their own section, so all symbols we are
361 interested in will have a section. */
362 /* Bfd symbols are section relative. */
363 symaddr
= sym
->value
+ sym
->section
->vma
;
364 /* Relocate all non-absolute and non-TLS symbols by the
366 if (sym
->section
!= &bfd_abs_section
367 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
371 /* For non-absolute symbols, use the type of the section
372 they are relative to, to intuit text/data. Bfd provides
373 no way of figuring this out for absolute symbols. */
374 if (sym
->section
== &bfd_abs_section
)
376 /* This is a hack to get the minimal symbol type
377 right for Irix 5, which has absolute addresses
378 with special section indices for dynamic symbols.
380 NOTE: uweigand-20071112: Synthetic symbols do not
381 have an ELF-private part, so do not touch those. */
382 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
383 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
393 case SHN_MIPS_ACOMMON
:
400 /* If it is an Irix dynamic symbol, skip section name
401 symbols, relocate all others by section offset. */
402 if (ms_type
!= mst_abs
)
404 if (sym
->name
[0] == '.')
409 else if (sym
->section
->flags
& SEC_CODE
)
411 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
413 if (sym
->flags
& BSF_GNU_INDIRECT_FUNCTION
)
414 ms_type
= mst_text_gnu_ifunc
;
418 /* The BSF_SYNTHETIC check is there to omit ppc64 function
419 descriptors mistaken for static functions starting with 'L'.
421 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L'
422 && (sym
->flags
& BSF_SYNTHETIC
) == 0)
423 || ((sym
->flags
& BSF_LOCAL
)
424 && sym
->name
[0] == '$'
425 && sym
->name
[1] == 'L'))
426 /* Looks like a compiler-generated label. Skip
427 it. The assembler should be skipping these (to
428 keep executables small), but apparently with
429 gcc on the (deleted) delta m88k SVR4, it loses.
430 So to have us check too should be harmless (but
431 I encourage people to fix this in the assembler
432 instead of adding checks here). */
436 ms_type
= mst_file_text
;
439 else if (sym
->section
->flags
& SEC_ALLOC
)
441 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
443 if (sym
->section
->flags
& SEC_LOAD
)
452 else if (sym
->flags
& BSF_LOCAL
)
454 /* Named Local variable in a Data section.
455 Check its name for stabs-in-elf. */
456 int special_local_sect
;
458 if (strcmp ("Bbss.bss", sym
->name
) == 0)
459 special_local_sect
= SECT_OFF_BSS (objfile
);
460 else if (strcmp ("Ddata.data", sym
->name
) == 0)
461 special_local_sect
= SECT_OFF_DATA (objfile
);
462 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
463 special_local_sect
= SECT_OFF_RODATA (objfile
);
465 special_local_sect
= -1;
466 if (special_local_sect
>= 0)
468 /* Found a special local symbol. Allocate a
469 sectinfo, if needed, and fill it in. */
470 if (sectinfo
== NULL
)
475 max_index
= SECT_OFF_BSS (objfile
);
476 if (objfile
->sect_index_data
> max_index
)
477 max_index
= objfile
->sect_index_data
;
478 if (objfile
->sect_index_rodata
> max_index
)
479 max_index
= objfile
->sect_index_rodata
;
481 /* max_index is the largest index we'll
482 use into this array, so we must
483 allocate max_index+1 elements for it.
484 However, 'struct stab_section_info'
485 already includes one element, so we
486 need to allocate max_index aadditional
488 size
= (sizeof (struct stab_section_info
)
489 + (sizeof (CORE_ADDR
) * max_index
));
490 sectinfo
= (struct stab_section_info
*)
492 memset (sectinfo
, 0, size
);
493 sectinfo
->num_sections
= max_index
;
496 complaint (&symfile_complaints
,
497 _("elf/stab section information %s "
498 "without a preceding file symbol"),
504 (char *) filesym
->name
;
507 if (sectinfo
->sections
[special_local_sect
] != 0)
508 complaint (&symfile_complaints
,
509 _("duplicated elf/stab section "
510 "information for %s"),
512 /* BFD symbols are section relative. */
513 symaddr
= sym
->value
+ sym
->section
->vma
;
514 /* Relocate non-absolute symbols by the
516 if (sym
->section
!= &bfd_abs_section
)
518 sectinfo
->sections
[special_local_sect
] = symaddr
;
519 /* The special local symbols don't go in the
520 minimal symbol table, so ignore this one. */
523 /* Not a special stabs-in-elf symbol, do regular
524 symbol processing. */
525 if (sym
->section
->flags
& SEC_LOAD
)
527 ms_type
= mst_file_data
;
531 ms_type
= mst_file_bss
;
536 ms_type
= mst_unknown
;
541 /* FIXME: Solaris2 shared libraries include lots of
542 odd "absolute" and "undefined" symbols, that play
543 hob with actions like finding what function the PC
544 is in. Ignore them if they aren't text, data, or bss. */
545 /* ms_type = mst_unknown; */
546 continue; /* Skip this symbol. */
548 msym
= record_minimal_symbol
549 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
550 ms_type
, sym
->section
, objfile
);
554 /* Pass symbol size field in via BFD. FIXME!!! */
555 elf_symbol_type
*elf_sym
;
557 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
558 ELF-private part. However, in some cases (e.g. synthetic
559 'dot' symbols on ppc64) the udata.p entry is set to point back
560 to the original ELF symbol it was derived from. Get the size
562 if (type
!= ST_SYNTHETIC
)
563 elf_sym
= (elf_symbol_type
*) sym
;
565 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
568 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
570 msym
->filename
= filesymname
;
571 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
574 /* For @plt symbols, also record a trampoline to the
575 destination symbol. The @plt symbol will be used in
576 disassembly, and the trampoline will be used when we are
577 trying to find the target. */
578 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
580 int len
= strlen (sym
->name
);
582 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
584 struct minimal_symbol
*mtramp
;
586 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
588 mst_solib_trampoline
,
589 sym
->section
, objfile
);
592 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
593 mtramp
->filename
= filesymname
;
594 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
602 /* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
603 for later look ups of which function to call when user requests
604 a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
605 library defining `function' we cannot yet know while reading OBJFILE which
606 of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
607 DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
610 elf_rel_plt_read (struct objfile
*objfile
, asymbol
**dyn_symbol_table
)
612 bfd
*obfd
= objfile
->obfd
;
613 const struct elf_backend_data
*bed
= get_elf_backend_data (obfd
);
614 asection
*plt
, *relplt
, *got_plt
;
617 bfd_size_type reloc_count
, reloc
;
618 char *string_buffer
= NULL
;
619 size_t string_buffer_size
= 0;
620 struct cleanup
*back_to
;
621 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
622 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
623 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
625 if (objfile
->separate_debug_objfile_backlink
)
628 plt
= bfd_get_section_by_name (obfd
, ".plt");
631 plt_elf_idx
= elf_section_data (plt
)->this_idx
;
633 got_plt
= bfd_get_section_by_name (obfd
, ".got.plt");
637 /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
638 for (relplt
= obfd
->sections
; relplt
!= NULL
; relplt
= relplt
->next
)
639 if (elf_section_data (relplt
)->this_hdr
.sh_info
== plt_elf_idx
640 && (elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_REL
641 || elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_RELA
))
646 if (! bed
->s
->slurp_reloc_table (obfd
, relplt
, dyn_symbol_table
, TRUE
))
649 back_to
= make_cleanup (free_current_contents
, &string_buffer
);
651 reloc_count
= relplt
->size
/ elf_section_data (relplt
)->this_hdr
.sh_entsize
;
652 for (reloc
= 0; reloc
< reloc_count
; reloc
++)
654 const char *name
, *name_got_plt
;
655 struct minimal_symbol
*msym
;
657 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
660 name
= bfd_asymbol_name (*relplt
->relocation
[reloc
].sym_ptr_ptr
);
661 name_len
= strlen (name
);
662 address
= relplt
->relocation
[reloc
].address
;
664 /* Does the pointer reside in the .got.plt section? */
665 if (!(bfd_get_section_vma (obfd
, got_plt
) <= address
666 && address
< bfd_get_section_vma (obfd
, got_plt
)
667 + bfd_get_section_size (got_plt
)))
670 /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
671 OBJFILE the symbol is undefined and the objfile having NAME defined
672 may not yet have been loaded. */
674 if (string_buffer_size
< name_len
+ got_suffix_len
+ 1)
676 string_buffer_size
= 2 * (name_len
+ got_suffix_len
);
677 string_buffer
= xrealloc (string_buffer
, string_buffer_size
);
679 memcpy (string_buffer
, name
, name_len
);
680 memcpy (&string_buffer
[name_len
], SYMBOL_GOT_PLT_SUFFIX
,
683 msym
= record_minimal_symbol (string_buffer
, name_len
+ got_suffix_len
,
684 1, address
, mst_slot_got_plt
, got_plt
,
687 MSYMBOL_SIZE (msym
) = ptr_size
;
690 do_cleanups (back_to
);
693 /* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
695 static const struct objfile_data
*elf_objfile_gnu_ifunc_cache_data
;
697 /* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
699 struct elf_gnu_ifunc_cache
701 /* This is always a function entry address, not a function descriptor. */
707 /* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
710 elf_gnu_ifunc_cache_hash (const void *a_voidp
)
712 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
714 return htab_hash_string (a
->name
);
717 /* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
720 elf_gnu_ifunc_cache_eq (const void *a_voidp
, const void *b_voidp
)
722 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
723 const struct elf_gnu_ifunc_cache
*b
= b_voidp
;
725 return strcmp (a
->name
, b
->name
) == 0;
728 /* Record the target function address of a STT_GNU_IFUNC function NAME is the
729 function entry address ADDR. Return 1 if NAME and ADDR are considered as
730 valid and therefore they were successfully recorded, return 0 otherwise.
732 Function does not expect a duplicate entry. Use
733 elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
737 elf_gnu_ifunc_record_cache (const char *name
, CORE_ADDR addr
)
739 struct minimal_symbol
*msym
;
741 struct objfile
*objfile
;
743 struct elf_gnu_ifunc_cache entry_local
, *entry_p
;
746 msym
= lookup_minimal_symbol_by_pc (addr
);
749 if (SYMBOL_VALUE_ADDRESS (msym
) != addr
)
751 /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
752 sect
= SYMBOL_OBJ_SECTION (msym
)->the_bfd_section
;
753 objfile
= SYMBOL_OBJ_SECTION (msym
)->objfile
;
755 /* If .plt jumps back to .plt the symbol is still deferred for later
756 resolution and it has no use for GDB. Besides ".text" this symbol can
757 reside also in ".opd" for ppc64 function descriptor. */
758 if (strcmp (bfd_get_section_name (objfile
->obfd
, sect
), ".plt") == 0)
761 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
764 htab
= htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash
,
765 elf_gnu_ifunc_cache_eq
,
766 NULL
, &objfile
->objfile_obstack
,
767 hashtab_obstack_allocate
,
768 dummy_obstack_deallocate
);
769 set_objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
, htab
);
772 entry_local
.addr
= addr
;
773 obstack_grow (&objfile
->objfile_obstack
, &entry_local
,
774 offsetof (struct elf_gnu_ifunc_cache
, name
));
775 obstack_grow_str0 (&objfile
->objfile_obstack
, name
);
776 entry_p
= obstack_finish (&objfile
->objfile_obstack
);
778 slot
= htab_find_slot (htab
, entry_p
, INSERT
);
781 struct elf_gnu_ifunc_cache
*entry_found_p
= *slot
;
782 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
784 if (entry_found_p
->addr
!= addr
)
786 /* This case indicates buggy inferior program, the resolved address
787 should never change. */
789 warning (_("gnu-indirect-function \"%s\" has changed its resolved "
790 "function_address from %s to %s"),
791 name
, paddress (gdbarch
, entry_found_p
->addr
),
792 paddress (gdbarch
, addr
));
795 /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
802 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
803 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
804 is not NULL) and the function returns 1. It returns 0 otherwise.
806 Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
810 elf_gnu_ifunc_resolve_by_cache (const char *name
, CORE_ADDR
*addr_p
)
812 struct objfile
*objfile
;
814 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
817 struct elf_gnu_ifunc_cache
*entry_p
;
820 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
824 entry_p
= alloca (sizeof (*entry_p
) + strlen (name
));
825 strcpy (entry_p
->name
, name
);
827 slot
= htab_find_slot (htab
, entry_p
, NO_INSERT
);
831 gdb_assert (entry_p
!= NULL
);
834 *addr_p
= entry_p
->addr
;
841 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
842 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
843 is not NULL) and the function returns 1. It returns 0 otherwise.
845 Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
846 elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
847 prevent cache entries duplicates. */
850 elf_gnu_ifunc_resolve_by_got (const char *name
, CORE_ADDR
*addr_p
)
853 struct objfile
*objfile
;
854 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
856 name_got_plt
= alloca (strlen (name
) + got_suffix_len
+ 1);
857 sprintf (name_got_plt
, "%s" SYMBOL_GOT_PLT_SUFFIX
, name
);
859 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
861 bfd
*obfd
= objfile
->obfd
;
862 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
863 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
864 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
865 CORE_ADDR pointer_address
, addr
;
867 gdb_byte
*buf
= alloca (ptr_size
);
868 struct minimal_symbol
*msym
;
870 msym
= lookup_minimal_symbol (name_got_plt
, NULL
, objfile
);
873 if (MSYMBOL_TYPE (msym
) != mst_slot_got_plt
)
875 pointer_address
= SYMBOL_VALUE_ADDRESS (msym
);
877 plt
= bfd_get_section_by_name (obfd
, ".plt");
881 if (MSYMBOL_SIZE (msym
) != ptr_size
)
883 if (target_read_memory (pointer_address
, buf
, ptr_size
) != 0)
885 addr
= extract_typed_address (buf
, ptr_type
);
886 addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
,
891 if (elf_gnu_ifunc_record_cache (name
, addr
))
898 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
899 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
900 is not NULL) and the function returns 1. It returns 0 otherwise.
902 Both the elf_objfile_gnu_ifunc_cache_data hash table and
903 SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
906 elf_gnu_ifunc_resolve_name (const char *name
, CORE_ADDR
*addr_p
)
908 if (elf_gnu_ifunc_resolve_by_cache (name
, addr_p
))
911 if (elf_gnu_ifunc_resolve_by_got (name
, addr_p
))
917 /* Call STT_GNU_IFUNC - a function returning addresss of a real function to
918 call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
919 is the entry point of the resolved STT_GNU_IFUNC target function to call.
923 elf_gnu_ifunc_resolve_addr (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
926 CORE_ADDR start_at_pc
, address
;
927 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
928 struct value
*function
, *address_val
;
930 /* Try first any non-intrusive methods without an inferior call. */
932 if (find_pc_partial_function (pc
, &name_at_pc
, &start_at_pc
, NULL
)
933 && start_at_pc
== pc
)
935 if (elf_gnu_ifunc_resolve_name (name_at_pc
, &address
))
941 function
= allocate_value (func_func_type
);
942 set_value_address (function
, pc
);
944 /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
945 function entry address. ADDRESS may be a function descriptor. */
947 address_val
= call_function_by_hand (function
, 0, NULL
);
948 address
= value_as_address (address_val
);
949 address
= gdbarch_convert_from_func_ptr_addr (gdbarch
, address
,
953 elf_gnu_ifunc_record_cache (name_at_pc
, address
);
958 /* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
961 elf_gnu_ifunc_resolver_stop (struct breakpoint
*b
)
963 struct breakpoint
*b_return
;
964 struct frame_info
*prev_frame
= get_prev_frame (get_current_frame ());
965 struct frame_id prev_frame_id
= get_stack_frame_id (prev_frame
);
966 CORE_ADDR prev_pc
= get_frame_pc (prev_frame
);
967 int thread_id
= pid_to_thread_id (inferior_ptid
);
969 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
971 for (b_return
= b
->related_breakpoint
; b_return
!= b
;
972 b_return
= b_return
->related_breakpoint
)
974 gdb_assert (b_return
->type
== bp_gnu_ifunc_resolver_return
);
975 gdb_assert (b_return
->loc
!= NULL
&& b_return
->loc
->next
== NULL
);
976 gdb_assert (frame_id_p (b_return
->frame_id
));
978 if (b_return
->thread
== thread_id
979 && b_return
->loc
->requested_address
== prev_pc
980 && frame_id_eq (b_return
->frame_id
, prev_frame_id
))
986 struct symtab_and_line sal
;
988 /* No need to call find_pc_line for symbols resolving as this is only
989 a helper breakpointer never shown to the user. */
992 sal
.pspace
= current_inferior ()->pspace
;
994 sal
.section
= find_pc_overlay (sal
.pc
);
996 b_return
= set_momentary_breakpoint (get_frame_arch (prev_frame
), sal
,
998 bp_gnu_ifunc_resolver_return
);
1000 /* Add new b_return to the ring list b->related_breakpoint. */
1001 gdb_assert (b_return
->related_breakpoint
== b_return
);
1002 b_return
->related_breakpoint
= b
->related_breakpoint
;
1003 b
->related_breakpoint
= b_return
;
1007 /* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
1010 elf_gnu_ifunc_resolver_return_stop (struct breakpoint
*b
)
1012 struct gdbarch
*gdbarch
= get_frame_arch (get_current_frame ());
1013 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
1014 struct type
*value_type
= TYPE_TARGET_TYPE (func_func_type
);
1015 struct regcache
*regcache
= get_thread_regcache (inferior_ptid
);
1016 struct value
*value
;
1017 CORE_ADDR resolved_address
, resolved_pc
;
1018 struct symtab_and_line sal
;
1019 struct symtabs_and_lines sals
, sals_end
;
1021 gdb_assert (b
->type
== bp_gnu_ifunc_resolver_return
);
1023 value
= allocate_value (value_type
);
1024 gdbarch_return_value (gdbarch
, func_func_type
, value_type
, regcache
,
1025 value_contents_raw (value
), NULL
);
1026 resolved_address
= value_as_address (value
);
1027 resolved_pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
1031 while (b
->related_breakpoint
!= b
)
1033 struct breakpoint
*b_next
= b
->related_breakpoint
;
1037 case bp_gnu_ifunc_resolver
:
1039 case bp_gnu_ifunc_resolver_return
:
1040 delete_breakpoint (b
);
1043 internal_error (__FILE__
, __LINE__
,
1044 _("handle_inferior_event: Invalid "
1045 "gnu-indirect-function breakpoint type %d"),
1050 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
1052 gdb_assert (current_program_space
== b
->pspace
|| b
->pspace
== NULL
);
1053 elf_gnu_ifunc_record_cache (b
->addr_string
, resolved_pc
);
1055 sal
= find_pc_line (resolved_pc
, 0);
1060 b
->type
= bp_breakpoint
;
1061 update_breakpoint_locations (b
, sals
, sals_end
);
1070 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
1072 static struct build_id
*
1073 build_id_bfd_get (bfd
*abfd
)
1075 struct build_id
*retval
;
1077 if (!bfd_check_format (abfd
, bfd_object
)
1078 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
1079 || elf_tdata (abfd
)->build_id
== NULL
)
1082 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
1083 retval
->size
= elf_tdata (abfd
)->build_id_size
;
1084 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
1089 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
1092 build_id_verify (const char *filename
, struct build_id
*check
)
1095 struct build_id
*found
= NULL
;
1098 /* We expect to be silent on the non-existing files. */
1099 abfd
= bfd_open_maybe_remote (filename
);
1103 found
= build_id_bfd_get (abfd
);
1106 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
1107 else if (found
->size
!= check
->size
1108 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
1109 warning (_("File \"%s\" has a different build-id, file skipped"),
1114 gdb_bfd_close_or_warn (abfd
);
1122 build_id_to_debug_filename (struct build_id
*build_id
)
1124 char *link
, *debugdir
, *retval
= NULL
;
1126 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
1127 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
1128 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
1130 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
1131 cause "/.build-id/..." lookups. */
1133 debugdir
= debug_file_directory
;
1136 char *s
, *debugdir_end
;
1137 gdb_byte
*data
= build_id
->data
;
1138 size_t size
= build_id
->size
;
1140 while (*debugdir
== DIRNAME_SEPARATOR
)
1143 debugdir_end
= strchr (debugdir
, DIRNAME_SEPARATOR
);
1144 if (debugdir_end
== NULL
)
1145 debugdir_end
= &debugdir
[strlen (debugdir
)];
1147 memcpy (link
, debugdir
, debugdir_end
- debugdir
);
1148 s
= &link
[debugdir_end
- debugdir
];
1149 s
+= sprintf (s
, "/.build-id/");
1153 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1158 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1159 strcpy (s
, ".debug");
1161 /* lrealpath() is expensive even for the usually non-existent files. */
1162 if (access (link
, F_OK
) == 0)
1163 retval
= lrealpath (link
);
1165 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
1174 debugdir
= debugdir_end
;
1176 while (*debugdir
!= 0);
1182 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
1184 struct build_id
*build_id
;
1186 build_id
= build_id_bfd_get (objfile
->obfd
);
1187 if (build_id
!= NULL
)
1189 char *build_id_name
;
1191 build_id_name
= build_id_to_debug_filename (build_id
);
1193 /* Prevent looping on a stripped .debug file. */
1194 if (build_id_name
!= NULL
1195 && filename_cmp (build_id_name
, objfile
->name
) == 0)
1197 warning (_("\"%s\": separate debug info file has no debug info"),
1199 xfree (build_id_name
);
1201 else if (build_id_name
!= NULL
)
1202 return build_id_name
;
1207 /* Scan and build partial symbols for a symbol file.
1208 We have been initialized by a call to elf_symfile_init, which
1209 currently does nothing.
1211 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
1212 in each section. We simplify it down to a single offset for all
1215 This function only does the minimum work necessary for letting the
1216 user "name" things symbolically; it does not read the entire symtab.
1217 Instead, it reads the external and static symbols and puts them in partial
1218 symbol tables. When more extensive information is requested of a
1219 file, the corresponding partial symbol table is mutated into a full
1220 fledged symbol table by going back and reading the symbols
1223 We look for sections with specific names, to tell us what debug
1224 format to look for: FIXME!!!
1226 elfstab_build_psymtabs() handles STABS symbols;
1227 mdebug_build_psymtabs() handles ECOFF debugging information.
1229 Note that ELF files have a "minimal" symbol table, which looks a lot
1230 like a COFF symbol table, but has only the minimal information necessary
1231 for linking. We process this also, and use the information to
1232 build gdb's minimal symbol table. This gives us some minimal debugging
1233 capability even for files compiled without -g. */
1236 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
1238 bfd
*synth_abfd
, *abfd
= objfile
->obfd
;
1240 struct cleanup
*back_to
;
1241 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
1242 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
1245 init_minimal_symbol_collection ();
1246 back_to
= make_cleanup_discard_minimal_symbols ();
1248 memset ((char *) &ei
, 0, sizeof (ei
));
1250 /* Allocate struct to keep track of the symfile. */
1251 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
1252 xmalloc (sizeof (struct dbx_symfile_info
));
1253 memset ((char *) objfile
->deprecated_sym_stab_info
,
1254 0, sizeof (struct dbx_symfile_info
));
1255 make_cleanup (free_elfinfo
, (void *) objfile
);
1257 /* Process the normal ELF symbol table first. This may write some
1258 chain of info into the dbx_symfile_info in
1259 objfile->deprecated_sym_stab_info, which can later be used by
1260 elfstab_offset_sections. */
1262 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
1263 if (storage_needed
< 0)
1264 error (_("Can't read symbols from %s: %s"),
1265 bfd_get_filename (objfile
->obfd
),
1266 bfd_errmsg (bfd_get_error ()));
1268 if (storage_needed
> 0)
1270 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
1271 make_cleanup (xfree
, symbol_table
);
1272 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
1275 error (_("Can't read symbols from %s: %s"),
1276 bfd_get_filename (objfile
->obfd
),
1277 bfd_errmsg (bfd_get_error ()));
1279 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
1282 /* Add the dynamic symbols. */
1284 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
1286 if (storage_needed
> 0)
1288 /* Memory gets permanently referenced from ABFD after
1289 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
1290 It happens only in the case when elf_slurp_reloc_table sees
1291 asection->relocation NULL. Determining which section is asection is
1292 done by _bfd_elf_get_synthetic_symtab which is all a bfd
1293 implementation detail, though. */
1295 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
1296 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
1299 if (dynsymcount
< 0)
1300 error (_("Can't read symbols from %s: %s"),
1301 bfd_get_filename (objfile
->obfd
),
1302 bfd_errmsg (bfd_get_error ()));
1304 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
1306 elf_rel_plt_read (objfile
, dyn_symbol_table
);
1309 /* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
1310 elfutils (eu-strip) moves even the .symtab section into the .debug file.
1312 bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
1313 'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
1314 address. But with eu-strip files bfd_get_synthetic_symtab would fail to
1315 read the code address from .opd while it reads the .symtab section from
1316 a separate debug info file as the .opd section is SHT_NOBITS there.
1318 With SYNTH_ABFD the .opd section will be read from the original
1319 backlinked binary where it is valid. */
1321 if (objfile
->separate_debug_objfile_backlink
)
1322 synth_abfd
= objfile
->separate_debug_objfile_backlink
->obfd
;
1326 /* Add synthetic symbols - for instance, names for any PLT entries. */
1328 synthcount
= bfd_get_synthetic_symtab (synth_abfd
, symcount
, symbol_table
,
1329 dynsymcount
, dyn_symbol_table
,
1333 asymbol
**synth_symbol_table
;
1336 make_cleanup (xfree
, synthsyms
);
1337 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
1338 for (i
= 0; i
< synthcount
; i
++)
1339 synth_symbol_table
[i
] = synthsyms
+ i
;
1340 make_cleanup (xfree
, synth_symbol_table
);
1341 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
1342 synth_symbol_table
, 1);
1345 /* Install any minimal symbols that have been collected as the current
1346 minimal symbols for this objfile. The debug readers below this point
1347 should not generate new minimal symbols; if they do it's their
1348 responsibility to install them. "mdebug" appears to be the only one
1349 which will do this. */
1351 install_minimal_symbols (objfile
);
1352 do_cleanups (back_to
);
1354 /* Now process debugging information, which is contained in
1355 special ELF sections. */
1357 /* We first have to find them... */
1358 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
1360 /* ELF debugging information is inserted into the psymtab in the
1361 order of least informative first - most informative last. Since
1362 the psymtab table is searched `most recent insertion first' this
1363 increases the probability that more detailed debug information
1364 for a section is found.
1366 For instance, an object file might contain both .mdebug (XCOFF)
1367 and .debug_info (DWARF2) sections then .mdebug is inserted first
1368 (searched last) and DWARF2 is inserted last (searched first). If
1369 we don't do this then the XCOFF info is found first - for code in
1370 an included file XCOFF info is useless. */
1374 const struct ecoff_debug_swap
*swap
;
1376 /* .mdebug section, presumably holding ECOFF debugging
1378 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
1380 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
1386 /* Stab sections have an associated string table that looks like
1387 a separate section. */
1388 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
1390 /* FIXME should probably warn about a stab section without a stabstr. */
1392 elfstab_build_psymtabs (objfile
,
1395 bfd_section_size (abfd
, str_sect
));
1398 if (dwarf2_has_info (objfile
, NULL
))
1400 /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
1401 information present in OBJFILE. If there is such debug info present
1402 never use .gdb_index. */
1404 if (!objfile_has_partial_symbols (objfile
)
1405 && dwarf2_initialize_objfile (objfile
))
1406 objfile
->sf
= &elf_sym_fns_gdb_index
;
1409 /* It is ok to do this even if the stabs reader made some
1410 partial symbols, because OBJF_PSYMTABS_READ has not been
1411 set, and so our lazy reader function will still be called
1413 objfile
->sf
= &elf_sym_fns_lazy_psyms
;
1416 /* If the file has its own symbol tables it has no separate debug
1417 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
1418 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
1419 `.note.gnu.build-id'. */
1420 else if (!objfile_has_partial_symbols (objfile
))
1424 debugfile
= find_separate_debug_file_by_buildid (objfile
);
1426 if (debugfile
== NULL
)
1427 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
1431 bfd
*abfd
= symfile_bfd_open (debugfile
);
1433 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
1439 /* Callback to lazily read psymtabs. */
1442 read_psyms (struct objfile
*objfile
)
1444 if (dwarf2_has_info (objfile
, NULL
))
1445 dwarf2_build_psymtabs (objfile
);
1448 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
1449 the chain of stab_section_info's, that might be dangling from
1453 free_elfinfo (void *objp
)
1455 struct objfile
*objfile
= (struct objfile
*) objp
;
1456 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
1457 struct stab_section_info
*ssi
, *nssi
;
1459 ssi
= dbxinfo
->stab_section_info
;
1467 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
1471 /* Initialize anything that needs initializing when a completely new symbol
1472 file is specified (not just adding some symbols from another file, e.g. a
1475 We reinitialize buildsym, since we may be reading stabs from an ELF
1479 elf_new_init (struct objfile
*ignore
)
1481 stabsread_new_init ();
1482 buildsym_new_init ();
1485 /* Perform any local cleanups required when we are done with a particular
1486 objfile. I.E, we are in the process of discarding all symbol information
1487 for an objfile, freeing up all memory held for it, and unlinking the
1488 objfile struct from the global list of known objfiles. */
1491 elf_symfile_finish (struct objfile
*objfile
)
1493 if (objfile
->deprecated_sym_stab_info
!= NULL
)
1495 xfree (objfile
->deprecated_sym_stab_info
);
1498 dwarf2_free_objfile (objfile
);
1501 /* ELF specific initialization routine for reading symbols.
1503 It is passed a pointer to a struct sym_fns which contains, among other
1504 things, the BFD for the file whose symbols are being read, and a slot for
1505 a pointer to "private data" which we can fill with goodies.
1507 For now at least, we have nothing in particular to do, so this function is
1511 elf_symfile_init (struct objfile
*objfile
)
1513 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1514 find this causes a significant slowdown in gdb then we could
1515 set it in the debug symbol readers only when necessary. */
1516 objfile
->flags
|= OBJF_REORDERED
;
1519 /* When handling an ELF file that contains Sun STABS debug info,
1520 some of the debug info is relative to the particular chunk of the
1521 section that was generated in its individual .o file. E.g.
1522 offsets to static variables are relative to the start of the data
1523 segment *for that module before linking*. This information is
1524 painfully squirreled away in the ELF symbol table as local symbols
1525 with wierd names. Go get 'em when needed. */
1528 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
1530 const char *filename
= pst
->filename
;
1531 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
1532 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1533 struct stab_section_info
*questionable
= 0;
1536 /* The ELF symbol info doesn't include path names, so strip the path
1537 (if any) from the psymtab filename. */
1538 filename
= lbasename (filename
);
1540 /* FIXME: This linear search could speed up significantly
1541 if it was chained in the right order to match how we search it,
1542 and if we unchained when we found a match. */
1543 for (; maybe
; maybe
= maybe
->next
)
1545 if (filename
[0] == maybe
->filename
[0]
1546 && filename_cmp (filename
, maybe
->filename
) == 0)
1548 /* We found a match. But there might be several source files
1549 (from different directories) with the same name. */
1550 if (0 == maybe
->found
)
1552 questionable
= maybe
; /* Might use it later. */
1556 if (maybe
== 0 && questionable
!= 0)
1558 complaint (&symfile_complaints
,
1559 _("elf/stab section information questionable for %s"),
1561 maybe
= questionable
;
1566 /* Found it! Allocate a new psymtab struct, and fill it in. */
1568 pst
->section_offsets
= (struct section_offsets
*)
1569 obstack_alloc (&objfile
->objfile_obstack
,
1570 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1571 for (i
= 0; i
< maybe
->num_sections
; i
++)
1572 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1576 /* We were unable to find any offsets for this file. Complain. */
1577 if (dbx
->stab_section_info
) /* If there *is* any info, */
1578 complaint (&symfile_complaints
,
1579 _("elf/stab section information missing for %s"), filename
);
1582 /* Register that we are able to handle ELF object file formats. */
1584 static const struct sym_fns elf_sym_fns
=
1586 bfd_target_elf_flavour
,
1587 elf_new_init
, /* init anything gbl to entire symtab */
1588 elf_symfile_init
, /* read initial info, setup for sym_read() */
1589 elf_symfile_read
, /* read a symbol file into symtab */
1590 NULL
, /* sym_read_psymbols */
1591 elf_symfile_finish
, /* finished with file, cleanup */
1592 default_symfile_offsets
, /* Translate ext. to int. relocation */
1593 elf_symfile_segments
, /* Get segment information from a file. */
1595 default_symfile_relocate
, /* Relocate a debug section. */
1599 /* The same as elf_sym_fns, but not registered and lazily reads
1602 static const struct sym_fns elf_sym_fns_lazy_psyms
=
1604 bfd_target_elf_flavour
,
1605 elf_new_init
, /* init anything gbl to entire symtab */
1606 elf_symfile_init
, /* read initial info, setup for sym_read() */
1607 elf_symfile_read
, /* read a symbol file into symtab */
1608 read_psyms
, /* sym_read_psymbols */
1609 elf_symfile_finish
, /* finished with file, cleanup */
1610 default_symfile_offsets
, /* Translate ext. to int. relocation */
1611 elf_symfile_segments
, /* Get segment information from a file. */
1613 default_symfile_relocate
, /* Relocate a debug section. */
1617 /* The same as elf_sym_fns, but not registered and uses the
1618 DWARF-specific GNU index rather than psymtab. */
1619 static const struct sym_fns elf_sym_fns_gdb_index
=
1621 bfd_target_elf_flavour
,
1622 elf_new_init
, /* init anything gbl to entire symab */
1623 elf_symfile_init
, /* read initial info, setup for sym_red() */
1624 elf_symfile_read
, /* read a symbol file into symtab */
1625 NULL
, /* sym_read_psymbols */
1626 elf_symfile_finish
, /* finished with file, cleanup */
1627 default_symfile_offsets
, /* Translate ext. to int. relocatin */
1628 elf_symfile_segments
, /* Get segment information from a file. */
1630 default_symfile_relocate
, /* Relocate a debug section. */
1631 &dwarf2_gdb_index_functions
1634 /* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
1636 static const struct gnu_ifunc_fns elf_gnu_ifunc_fns
=
1638 elf_gnu_ifunc_resolve_addr
,
1639 elf_gnu_ifunc_resolve_name
,
1640 elf_gnu_ifunc_resolver_stop
,
1641 elf_gnu_ifunc_resolver_return_stop
1645 _initialize_elfread (void)
1647 add_symtab_fns (&elf_sym_fns
);
1649 elf_objfile_gnu_ifunc_cache_data
= register_objfile_data ();
1650 gnu_ifunc_fns_p
= &elf_gnu_ifunc_fns
;