Import gdb 7.3 into vendor branch
[dragonfly.git] / contrib / gdb-7 / gdb / elfread.c
CommitLineData
5796c8dc
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1/* Read ELF (Executable and Linking Format) object files for GDB.
2
3 Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
c50c785c 4 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5796c8dc
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5 Free Software Foundation, Inc.
6
7 Written by Fred Fish at Cygnus Support.
8
9 This file is part of GDB.
10
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.
15
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.
20
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/>. */
23
24#include "defs.h"
25#include "bfd.h"
26#include "gdb_string.h"
27#include "elf-bfd.h"
28#include "elf/common.h"
29#include "elf/internal.h"
30#include "elf/mips.h"
31#include "symtab.h"
32#include "symfile.h"
33#include "objfiles.h"
34#include "buildsym.h"
35#include "stabsread.h"
36#include "gdb-stabs.h"
37#include "complaints.h"
38#include "demangle.h"
cf7f2e2d 39#include "psympriv.h"
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40#include "filenames.h"
41#include "gdbtypes.h"
42#include "value.h"
43#include "infcall.h"
44#include "gdbthread.h"
45#include "regcache.h"
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46
47extern void _initialize_elfread (void);
48
c50c785c
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49/* Forward declarations. */
50static const struct sym_fns elf_sym_fns_gdb_index;
51static const struct sym_fns elf_sym_fns_lazy_psyms;
52
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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. */
56
57struct elfinfo
58 {
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 */
62 };
63
64static void free_elfinfo (void *);
65
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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. */
70
71#define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
72
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73/* Locate the segments in ABFD. */
74
75static struct symfile_segment_data *
76elf_symfile_segments (bfd *abfd)
77{
78 Elf_Internal_Phdr *phdrs, **segments;
79 long phdrs_size;
80 int num_phdrs, num_segments, num_sections, i;
81 asection *sect;
82 struct symfile_segment_data *data;
83
84 phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
85 if (phdrs_size == -1)
86 return NULL;
87
88 phdrs = alloca (phdrs_size);
89 num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
90 if (num_phdrs == -1)
91 return NULL;
92
93 num_segments = 0;
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];
98
99 if (num_segments == 0)
100 return NULL;
101
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);
106
107 for (i = 0; i < num_segments; i++)
108 {
109 data->segment_bases[i] = segments[i]->p_vaddr;
110 data->segment_sizes[i] = segments[i]->p_memsz;
111 }
112
113 num_sections = bfd_count_sections (abfd);
114 data->segment_info = XCALLOC (num_sections, int);
115
116 for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next)
117 {
118 int j;
119 CORE_ADDR vma;
120
121 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
122 continue;
123
124 vma = bfd_get_section_vma (abfd, sect);
125
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)
130 {
131 data->segment_info[i] = j + 1;
132 break;
133 }
134
cf7f2e2d
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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)
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146 warning (_("Loadable segment \"%s\" outside of ELF segments"),
147 bfd_section_name (abfd, sect));
148 }
149
150 return data;
151}
152
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.
157
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
162 used).
163
164 We also recognize the ".stab" sections used by the Sun compilers
165 released with Solaris 2.
166
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
c50c785c 169 section flags to specify what kind of debug section it is.
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170 -kingdon). */
171
172static void
173elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip)
174{
175 struct elfinfo *ei;
176
177 ei = (struct elfinfo *) eip;
178 if (strcmp (sectp->name, ".stab") == 0)
179 {
180 ei->stabsect = sectp;
181 }
182 else if (strcmp (sectp->name, ".stab.index") == 0)
183 {
184 ei->stabindexsect = sectp;
185 }
186 else if (strcmp (sectp->name, ".mdebug") == 0)
187 {
188 ei->mdebugsect = sectp;
189 }
190}
191
192static struct minimal_symbol *
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193record_minimal_symbol (const char *name, int name_len, int copy_name,
194 CORE_ADDR address,
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195 enum minimal_symbol_type ms_type,
196 asection *bfd_section, struct objfile *objfile)
197{
198 struct gdbarch *gdbarch = get_objfile_arch (objfile);
199
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200 if (ms_type == mst_text || ms_type == mst_file_text
201 || ms_type == mst_text_gnu_ifunc)
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202 address = gdbarch_smash_text_address (gdbarch, address);
203
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204 return prim_record_minimal_symbol_full (name, name_len, copy_name, address,
205 ms_type, bfd_section->index,
206 bfd_section, objfile);
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207}
208
209/*
210
211 LOCAL FUNCTION
212
213 elf_symtab_read -- read the symbol table of an ELF file
214
215 SYNOPSIS
216
217 void elf_symtab_read (struct objfile *objfile, int type,
218 long number_of_symbols, asymbol **symbol_table)
219
220 DESCRIPTION
221
222 Given an objfile, a symbol table, and a flag indicating whether the
223 symbol table contains regular, dynamic, or synthetic symbols, add all
224 the global function and data symbols to the minimal symbol table.
225
226 In stabs-in-ELF, as implemented by Sun, there are some local symbols
227 defined in the ELF symbol table, which can be used to locate
228 the beginnings of sections from each ".o" file that was linked to
229 form the executable objfile. We gather any such info and record it
230 in data structures hung off the objfile's private data.
231
232 */
233
234#define ST_REGULAR 0
235#define ST_DYNAMIC 1
236#define ST_SYNTHETIC 2
237
238static void
239elf_symtab_read (struct objfile *objfile, int type,
cf7f2e2d
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240 long number_of_symbols, asymbol **symbol_table,
241 int copy_names)
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242{
243 struct gdbarch *gdbarch = get_objfile_arch (objfile);
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244 asymbol *sym;
245 long i;
246 CORE_ADDR symaddr;
247 CORE_ADDR offset;
248 enum minimal_symbol_type ms_type;
249 /* If sectinfo is nonNULL, it contains section info that should end up
250 filed in the objfile. */
251 struct stab_section_info *sectinfo = NULL;
252 /* If filesym is nonzero, it points to a file symbol, but we haven't
253 seen any section info for it yet. */
254 asymbol *filesym = 0;
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255 /* Name of filesym. This is either a constant string or is saved on
256 the objfile's obstack. */
257 char *filesymname = "";
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258 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
259 int stripped = (bfd_get_symcount (objfile->obfd) == 0);
260
261 for (i = 0; i < number_of_symbols; i++)
262 {
263 sym = symbol_table[i];
264 if (sym->name == NULL || *sym->name == '\0')
265 {
266 /* Skip names that don't exist (shouldn't happen), or names
c50c785c 267 that are null strings (may happen). */
5796c8dc
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268 continue;
269 }
270
271 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
272 symbols which do not correspond to objects in the symbol table,
273 but have some other target-specific meaning. */
274 if (bfd_is_target_special_symbol (objfile->obfd, sym))
275 {
276 if (gdbarch_record_special_symbol_p (gdbarch))
277 gdbarch_record_special_symbol (gdbarch, objfile, sym);
278 continue;
279 }
280
281 offset = ANOFFSET (objfile->section_offsets, sym->section->index);
282 if (type == ST_DYNAMIC
283 && sym->section == &bfd_und_section
284 && (sym->flags & BSF_FUNCTION))
285 {
286 struct minimal_symbol *msym;
287 bfd *abfd = objfile->obfd;
288 asection *sect;
289
290 /* Symbol is a reference to a function defined in
291 a shared library.
292 If its value is non zero then it is usually the address
293 of the corresponding entry in the procedure linkage table,
294 plus the desired section offset.
295 If its value is zero then the dynamic linker has to resolve
c50c785c 296 the symbol. We are unable to find any meaningful address
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297 for this symbol in the executable file, so we skip it. */
298 symaddr = sym->value;
299 if (symaddr == 0)
300 continue;
301
302 /* sym->section is the undefined section. However, we want to
303 record the section where the PLT stub resides with the
304 minimal symbol. Search the section table for the one that
305 covers the stub's address. */
306 for (sect = abfd->sections; sect != NULL; sect = sect->next)
307 {
308 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
309 continue;
310
311 if (symaddr >= bfd_get_section_vma (abfd, sect)
312 && symaddr < bfd_get_section_vma (abfd, sect)
313 + bfd_get_section_size (sect))
314 break;
315 }
316 if (!sect)
317 continue;
318
319 symaddr += ANOFFSET (objfile->section_offsets, sect->index);
320
321 msym = record_minimal_symbol
cf7f2e2d
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322 (sym->name, strlen (sym->name), copy_names,
323 symaddr, mst_solib_trampoline, sect, objfile);
5796c8dc
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324 if (msym != NULL)
325 msym->filename = filesymname;
326 continue;
327 }
328
329 /* If it is a nonstripped executable, do not enter dynamic
330 symbols, as the dynamic symbol table is usually a subset
331 of the main symbol table. */
332 if (type == ST_DYNAMIC && !stripped)
333 continue;
334 if (sym->flags & BSF_FILE)
335 {
336 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
337 Chain any old one onto the objfile; remember new sym. */
338 if (sectinfo != NULL)
339 {
340 sectinfo->next = dbx->stab_section_info;
341 dbx->stab_section_info = sectinfo;
342 sectinfo = NULL;
343 }
344 filesym = sym;
345 filesymname =
346 obsavestring ((char *) filesym->name, strlen (filesym->name),
347 &objfile->objfile_obstack);
348 }
349 else if (sym->flags & BSF_SECTION_SYM)
350 continue;
351 else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK))
352 {
353 struct minimal_symbol *msym;
354
355 /* Select global/local/weak symbols. Note that bfd puts abs
356 symbols in their own section, so all symbols we are
c50c785c
JM
357 interested in will have a section. */
358 /* Bfd symbols are section relative. */
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359 symaddr = sym->value + sym->section->vma;
360 /* Relocate all non-absolute and non-TLS symbols by the
361 section offset. */
362 if (sym->section != &bfd_abs_section
363 && !(sym->section->flags & SEC_THREAD_LOCAL))
364 {
365 symaddr += offset;
366 }
367 /* For non-absolute symbols, use the type of the section
368 they are relative to, to intuit text/data. Bfd provides
c50c785c 369 no way of figuring this out for absolute symbols. */
5796c8dc
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370 if (sym->section == &bfd_abs_section)
371 {
372 /* This is a hack to get the minimal symbol type
373 right for Irix 5, which has absolute addresses
374 with special section indices for dynamic symbols.
375
376 NOTE: uweigand-20071112: Synthetic symbols do not
377 have an ELF-private part, so do not touch those. */
378 unsigned int shndx = type == ST_SYNTHETIC ? 0 :
379 ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx;
380
381 switch (shndx)
382 {
383 case SHN_MIPS_TEXT:
384 ms_type = mst_text;
385 break;
386 case SHN_MIPS_DATA:
387 ms_type = mst_data;
388 break;
389 case SHN_MIPS_ACOMMON:
390 ms_type = mst_bss;
391 break;
392 default:
393 ms_type = mst_abs;
394 }
395
396 /* If it is an Irix dynamic symbol, skip section name
c50c785c 397 symbols, relocate all others by section offset. */
5796c8dc
SS
398 if (ms_type != mst_abs)
399 {
400 if (sym->name[0] == '.')
401 continue;
402 symaddr += offset;
403 }
404 }
405 else if (sym->section->flags & SEC_CODE)
406 {
407 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
408 {
c50c785c
JM
409 if (sym->flags & BSF_GNU_INDIRECT_FUNCTION)
410 ms_type = mst_text_gnu_ifunc;
411 else
412 ms_type = mst_text;
5796c8dc
SS
413 }
414 else if ((sym->name[0] == '.' && sym->name[1] == 'L')
415 || ((sym->flags & BSF_LOCAL)
416 && sym->name[0] == '$'
417 && sym->name[1] == 'L'))
418 /* Looks like a compiler-generated label. Skip
419 it. The assembler should be skipping these (to
420 keep executables small), but apparently with
421 gcc on the (deleted) delta m88k SVR4, it loses.
422 So to have us check too should be harmless (but
423 I encourage people to fix this in the assembler
424 instead of adding checks here). */
425 continue;
426 else
427 {
428 ms_type = mst_file_text;
429 }
430 }
431 else if (sym->section->flags & SEC_ALLOC)
432 {
433 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
434 {
435 if (sym->section->flags & SEC_LOAD)
436 {
437 ms_type = mst_data;
438 }
439 else
440 {
441 ms_type = mst_bss;
442 }
443 }
444 else if (sym->flags & BSF_LOCAL)
445 {
446 /* Named Local variable in a Data section.
447 Check its name for stabs-in-elf. */
448 int special_local_sect;
cf7f2e2d 449
5796c8dc
SS
450 if (strcmp ("Bbss.bss", sym->name) == 0)
451 special_local_sect = SECT_OFF_BSS (objfile);
452 else if (strcmp ("Ddata.data", sym->name) == 0)
453 special_local_sect = SECT_OFF_DATA (objfile);
454 else if (strcmp ("Drodata.rodata", sym->name) == 0)
455 special_local_sect = SECT_OFF_RODATA (objfile);
456 else
457 special_local_sect = -1;
458 if (special_local_sect >= 0)
459 {
460 /* Found a special local symbol. Allocate a
461 sectinfo, if needed, and fill it in. */
462 if (sectinfo == NULL)
463 {
464 int max_index;
465 size_t size;
466
467 max_index = SECT_OFF_BSS (objfile);
468 if (objfile->sect_index_data > max_index)
469 max_index = objfile->sect_index_data;
470 if (objfile->sect_index_rodata > max_index)
471 max_index = objfile->sect_index_rodata;
472
473 /* max_index is the largest index we'll
474 use into this array, so we must
475 allocate max_index+1 elements for it.
476 However, 'struct stab_section_info'
477 already includes one element, so we
478 need to allocate max_index aadditional
479 elements. */
480 size = (sizeof (struct stab_section_info)
c50c785c 481 + (sizeof (CORE_ADDR) * max_index));
5796c8dc
SS
482 sectinfo = (struct stab_section_info *)
483 xmalloc (size);
484 memset (sectinfo, 0, size);
485 sectinfo->num_sections = max_index;
486 if (filesym == NULL)
487 {
488 complaint (&symfile_complaints,
c50c785c
JM
489 _("elf/stab section information %s "
490 "without a preceding file symbol"),
5796c8dc
SS
491 sym->name);
492 }
493 else
494 {
495 sectinfo->filename =
496 (char *) filesym->name;
497 }
498 }
499 if (sectinfo->sections[special_local_sect] != 0)
500 complaint (&symfile_complaints,
c50c785c
JM
501 _("duplicated elf/stab section "
502 "information for %s"),
5796c8dc
SS
503 sectinfo->filename);
504 /* BFD symbols are section relative. */
505 symaddr = sym->value + sym->section->vma;
506 /* Relocate non-absolute symbols by the
507 section offset. */
508 if (sym->section != &bfd_abs_section)
509 symaddr += offset;
510 sectinfo->sections[special_local_sect] = symaddr;
511 /* The special local symbols don't go in the
512 minimal symbol table, so ignore this one. */
513 continue;
514 }
515 /* Not a special stabs-in-elf symbol, do regular
516 symbol processing. */
517 if (sym->section->flags & SEC_LOAD)
518 {
519 ms_type = mst_file_data;
520 }
521 else
522 {
523 ms_type = mst_file_bss;
524 }
525 }
526 else
527 {
528 ms_type = mst_unknown;
529 }
530 }
531 else
532 {
533 /* FIXME: Solaris2 shared libraries include lots of
534 odd "absolute" and "undefined" symbols, that play
535 hob with actions like finding what function the PC
536 is in. Ignore them if they aren't text, data, or bss. */
537 /* ms_type = mst_unknown; */
c50c785c 538 continue; /* Skip this symbol. */
5796c8dc
SS
539 }
540 msym = record_minimal_symbol
cf7f2e2d 541 (sym->name, strlen (sym->name), copy_names, symaddr,
5796c8dc
SS
542 ms_type, sym->section, objfile);
543
544 if (msym)
545 {
546 /* Pass symbol size field in via BFD. FIXME!!! */
547 elf_symbol_type *elf_sym;
548
549 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
550 ELF-private part. However, in some cases (e.g. synthetic
551 'dot' symbols on ppc64) the udata.p entry is set to point back
552 to the original ELF symbol it was derived from. Get the size
553 from that symbol. */
554 if (type != ST_SYNTHETIC)
555 elf_sym = (elf_symbol_type *) sym;
556 else
557 elf_sym = (elf_symbol_type *) sym->udata.p;
558
559 if (elf_sym)
560 MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size;
cf7f2e2d
JM
561
562 msym->filename = filesymname;
563 gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
5796c8dc 564 }
5796c8dc
SS
565
566 /* For @plt symbols, also record a trampoline to the
567 destination symbol. The @plt symbol will be used in
568 disassembly, and the trampoline will be used when we are
569 trying to find the target. */
570 if (msym && ms_type == mst_text && type == ST_SYNTHETIC)
571 {
572 int len = strlen (sym->name);
573
574 if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
575 {
5796c8dc
SS
576 struct minimal_symbol *mtramp;
577
cf7f2e2d
JM
578 mtramp = record_minimal_symbol (sym->name, len - 4, 1,
579 symaddr,
5796c8dc
SS
580 mst_solib_trampoline,
581 sym->section, objfile);
582 if (mtramp)
583 {
584 MSYMBOL_SIZE (mtramp) = MSYMBOL_SIZE (msym);
585 mtramp->filename = filesymname;
586 gdbarch_elf_make_msymbol_special (gdbarch, sym, mtramp);
587 }
588 }
589 }
590 }
591 }
592}
593
c50c785c
JM
594/* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
595 for later look ups of which function to call when user requests
596 a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
597 library defining `function' we cannot yet know while reading OBJFILE which
598 of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
599 DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
600
601static void
602elf_rel_plt_read (struct objfile *objfile, asymbol **dyn_symbol_table)
603{
604 bfd *obfd = objfile->obfd;
605 const struct elf_backend_data *bed = get_elf_backend_data (obfd);
606 asection *plt, *relplt, *got_plt;
607 unsigned u;
608 int plt_elf_idx;
609 bfd_size_type reloc_count, reloc;
610 char *string_buffer = NULL;
611 size_t string_buffer_size = 0;
612 struct cleanup *back_to;
613 struct gdbarch *gdbarch = objfile->gdbarch;
614 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
615 size_t ptr_size = TYPE_LENGTH (ptr_type);
616
617 if (objfile->separate_debug_objfile_backlink)
618 return;
619
620 plt = bfd_get_section_by_name (obfd, ".plt");
621 if (plt == NULL)
622 return;
623 plt_elf_idx = elf_section_data (plt)->this_idx;
624
625 got_plt = bfd_get_section_by_name (obfd, ".got.plt");
626 if (got_plt == NULL)
627 return;
628
629 /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
630 for (relplt = obfd->sections; relplt != NULL; relplt = relplt->next)
631 if (elf_section_data (relplt)->this_hdr.sh_info == plt_elf_idx
632 && (elf_section_data (relplt)->this_hdr.sh_type == SHT_REL
633 || elf_section_data (relplt)->this_hdr.sh_type == SHT_RELA))
634 break;
635 if (relplt == NULL)
636 return;
637
638 if (! bed->s->slurp_reloc_table (obfd, relplt, dyn_symbol_table, TRUE))
639 return;
640
641 back_to = make_cleanup (free_current_contents, &string_buffer);
642
643 reloc_count = relplt->size / elf_section_data (relplt)->this_hdr.sh_entsize;
644 for (reloc = 0; reloc < reloc_count; reloc++)
645 {
646 const char *name, *name_got_plt;
647 struct minimal_symbol *msym;
648 CORE_ADDR address;
649 const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
650 size_t name_len;
651
652 name = bfd_asymbol_name (*relplt->relocation[reloc].sym_ptr_ptr);
653 name_len = strlen (name);
654 address = relplt->relocation[reloc].address;
655
656 /* Does the pointer reside in the .got.plt section? */
657 if (!(bfd_get_section_vma (obfd, got_plt) <= address
658 && address < bfd_get_section_vma (obfd, got_plt)
659 + bfd_get_section_size (got_plt)))
660 continue;
661
662 /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
663 OBJFILE the symbol is undefined and the objfile having NAME defined
664 may not yet have been loaded. */
665
666 if (string_buffer_size < name_len + got_suffix_len)
667 {
668 string_buffer_size = 2 * (name_len + got_suffix_len);
669 string_buffer = xrealloc (string_buffer, string_buffer_size);
670 }
671 memcpy (string_buffer, name, name_len);
672 memcpy (&string_buffer[name_len], SYMBOL_GOT_PLT_SUFFIX,
673 got_suffix_len);
674
675 msym = record_minimal_symbol (string_buffer, name_len + got_suffix_len,
676 1, address, mst_slot_got_plt, got_plt,
677 objfile);
678 if (msym)
679 MSYMBOL_SIZE (msym) = ptr_size;
680 }
681
682 do_cleanups (back_to);
683}
684
685/* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
686
687static const struct objfile_data *elf_objfile_gnu_ifunc_cache_data;
688
689/* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
690
691struct elf_gnu_ifunc_cache
692{
693 /* This is always a function entry address, not a function descriptor. */
694 CORE_ADDR addr;
695
696 char name[1];
697};
698
699/* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
700
701static hashval_t
702elf_gnu_ifunc_cache_hash (const void *a_voidp)
703{
704 const struct elf_gnu_ifunc_cache *a = a_voidp;
705
706 return htab_hash_string (a->name);
707}
708
709/* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
710
711static int
712elf_gnu_ifunc_cache_eq (const void *a_voidp, const void *b_voidp)
713{
714 const struct elf_gnu_ifunc_cache *a = a_voidp;
715 const struct elf_gnu_ifunc_cache *b = b_voidp;
716
717 return strcmp (a->name, b->name) == 0;
718}
719
720/* Record the target function address of a STT_GNU_IFUNC function NAME is the
721 function entry address ADDR. Return 1 if NAME and ADDR are considered as
722 valid and therefore they were successfully recorded, return 0 otherwise.
723
724 Function does not expect a duplicate entry. Use
725 elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
726 exists. */
727
728static int
729elf_gnu_ifunc_record_cache (const char *name, CORE_ADDR addr)
730{
731 struct minimal_symbol *msym;
732 asection *sect;
733 struct objfile *objfile;
734 htab_t htab;
735 struct elf_gnu_ifunc_cache entry_local, *entry_p;
736 void **slot;
737
738 msym = lookup_minimal_symbol_by_pc (addr);
739 if (msym == NULL)
740 return 0;
741 if (SYMBOL_VALUE_ADDRESS (msym) != addr)
742 return 0;
743 /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
744 sect = SYMBOL_OBJ_SECTION (msym)->the_bfd_section;
745 objfile = SYMBOL_OBJ_SECTION (msym)->objfile;
746
747 /* If .plt jumps back to .plt the symbol is still deferred for later
748 resolution and it has no use for GDB. Besides ".text" this symbol can
749 reside also in ".opd" for ppc64 function descriptor. */
750 if (strcmp (bfd_get_section_name (objfile->obfd, sect), ".plt") == 0)
751 return 0;
752
753 htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
754 if (htab == NULL)
755 {
756 htab = htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash,
757 elf_gnu_ifunc_cache_eq,
758 NULL, &objfile->objfile_obstack,
759 hashtab_obstack_allocate,
760 dummy_obstack_deallocate);
761 set_objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data, htab);
762 }
763
764 entry_local.addr = addr;
765 obstack_grow (&objfile->objfile_obstack, &entry_local,
766 offsetof (struct elf_gnu_ifunc_cache, name));
767 obstack_grow_str0 (&objfile->objfile_obstack, name);
768 entry_p = obstack_finish (&objfile->objfile_obstack);
769
770 slot = htab_find_slot (htab, entry_p, INSERT);
771 if (*slot != NULL)
772 {
773 struct elf_gnu_ifunc_cache *entry_found_p = *slot;
774 struct gdbarch *gdbarch = objfile->gdbarch;
775
776 if (entry_found_p->addr != addr)
777 {
778 /* This case indicates buggy inferior program, the resolved address
779 should never change. */
780
781 warning (_("gnu-indirect-function \"%s\" has changed its resolved "
782 "function_address from %s to %s"),
783 name, paddress (gdbarch, entry_found_p->addr),
784 paddress (gdbarch, addr));
785 }
786
787 /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
788 }
789 *slot = entry_p;
790
791 return 1;
792}
793
794/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
795 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
796 is not NULL) and the function returns 1. It returns 0 otherwise.
797
798 Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
799 function. */
800
801static int
802elf_gnu_ifunc_resolve_by_cache (const char *name, CORE_ADDR *addr_p)
803{
804 struct objfile *objfile;
805
806 ALL_PSPACE_OBJFILES (current_program_space, objfile)
807 {
808 htab_t htab;
809 struct elf_gnu_ifunc_cache *entry_p;
810 void **slot;
811
812 htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
813 if (htab == NULL)
814 continue;
815
816 entry_p = alloca (sizeof (*entry_p) + strlen (name));
817 strcpy (entry_p->name, name);
818
819 slot = htab_find_slot (htab, entry_p, NO_INSERT);
820 if (slot == NULL)
821 continue;
822 entry_p = *slot;
823 gdb_assert (entry_p != NULL);
824
825 if (addr_p)
826 *addr_p = entry_p->addr;
827 return 1;
828 }
829
830 return 0;
831}
832
833/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
834 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
835 is not NULL) and the function returns 1. It returns 0 otherwise.
836
837 Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
838 elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
839 prevent cache entries duplicates. */
840
841static int
842elf_gnu_ifunc_resolve_by_got (const char *name, CORE_ADDR *addr_p)
843{
844 char *name_got_plt;
845 struct objfile *objfile;
846 const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
847
848 name_got_plt = alloca (strlen (name) + got_suffix_len + 1);
849 sprintf (name_got_plt, "%s" SYMBOL_GOT_PLT_SUFFIX, name);
850
851 ALL_PSPACE_OBJFILES (current_program_space, objfile)
852 {
853 bfd *obfd = objfile->obfd;
854 struct gdbarch *gdbarch = objfile->gdbarch;
855 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
856 size_t ptr_size = TYPE_LENGTH (ptr_type);
857 CORE_ADDR pointer_address, addr;
858 asection *plt;
859 gdb_byte *buf = alloca (ptr_size);
860 struct minimal_symbol *msym;
861
862 msym = lookup_minimal_symbol (name_got_plt, NULL, objfile);
863 if (msym == NULL)
864 continue;
865 if (MSYMBOL_TYPE (msym) != mst_slot_got_plt)
866 continue;
867 pointer_address = SYMBOL_VALUE_ADDRESS (msym);
868
869 plt = bfd_get_section_by_name (obfd, ".plt");
870 if (plt == NULL)
871 continue;
872
873 if (MSYMBOL_SIZE (msym) != ptr_size)
874 continue;
875 if (target_read_memory (pointer_address, buf, ptr_size) != 0)
876 continue;
877 addr = extract_typed_address (buf, ptr_type);
878 addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr,
879 &current_target);
880
881 if (addr_p)
882 *addr_p = addr;
883 if (elf_gnu_ifunc_record_cache (name, addr))
884 return 1;
885 }
886
887 return 0;
888}
889
890/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
891 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
892 is not NULL) and the function returns 1. It returns 0 otherwise.
893
894 Both the elf_objfile_gnu_ifunc_cache_data hash table and
895 SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
896
897static int
898elf_gnu_ifunc_resolve_name (const char *name, CORE_ADDR *addr_p)
899{
900 if (elf_gnu_ifunc_resolve_by_cache (name, addr_p))
901 return 1;
902
903 if (elf_gnu_ifunc_resolve_by_got (name, addr_p))
904 return 1;
905
906 return 0;
907}
908
909/* Call STT_GNU_IFUNC - a function returning addresss of a real function to
910 call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
911 is the entry point of the resolved STT_GNU_IFUNC target function to call.
912 */
913
914static CORE_ADDR
915elf_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
916{
917 char *name_at_pc;
918 CORE_ADDR start_at_pc, address;
919 struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
920 struct value *function, *address_val;
921
922 /* Try first any non-intrusive methods without an inferior call. */
923
924 if (find_pc_partial_function (pc, &name_at_pc, &start_at_pc, NULL)
925 && start_at_pc == pc)
926 {
927 if (elf_gnu_ifunc_resolve_name (name_at_pc, &address))
928 return address;
929 }
930 else
931 name_at_pc = NULL;
932
933 function = allocate_value (func_func_type);
934 set_value_address (function, pc);
935
936 /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
937 function entry address. ADDRESS may be a function descriptor. */
938
939 address_val = call_function_by_hand (function, 0, NULL);
940 address = value_as_address (address_val);
941 address = gdbarch_convert_from_func_ptr_addr (gdbarch, address,
942 &current_target);
943
944 if (name_at_pc)
945 elf_gnu_ifunc_record_cache (name_at_pc, address);
946
947 return address;
948}
949
950/* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
951
952static void
953elf_gnu_ifunc_resolver_stop (struct breakpoint *b)
954{
955 struct breakpoint *b_return;
956 struct frame_info *prev_frame = get_prev_frame (get_current_frame ());
957 struct frame_id prev_frame_id = get_stack_frame_id (prev_frame);
958 CORE_ADDR prev_pc = get_frame_pc (prev_frame);
959 int thread_id = pid_to_thread_id (inferior_ptid);
960
961 gdb_assert (b->type == bp_gnu_ifunc_resolver);
962
963 for (b_return = b->related_breakpoint; b_return != b;
964 b_return = b_return->related_breakpoint)
965 {
966 gdb_assert (b_return->type == bp_gnu_ifunc_resolver_return);
967 gdb_assert (b_return->loc != NULL && b_return->loc->next == NULL);
968 gdb_assert (frame_id_p (b_return->frame_id));
969
970 if (b_return->thread == thread_id
971 && b_return->loc->requested_address == prev_pc
972 && frame_id_eq (b_return->frame_id, prev_frame_id))
973 break;
974 }
975
976 if (b_return == b)
977 {
978 struct symtab_and_line sal;
979
980 /* No need to call find_pc_line for symbols resolving as this is only
981 a helper breakpointer never shown to the user. */
982
983 init_sal (&sal);
984 sal.pspace = current_inferior ()->pspace;
985 sal.pc = prev_pc;
986 sal.section = find_pc_overlay (sal.pc);
987 sal.explicit_pc = 1;
988 b_return = set_momentary_breakpoint (get_frame_arch (prev_frame), sal,
989 prev_frame_id,
990 bp_gnu_ifunc_resolver_return);
991
992 /* Add new b_return to the ring list b->related_breakpoint. */
993 gdb_assert (b_return->related_breakpoint == b_return);
994 b_return->related_breakpoint = b->related_breakpoint;
995 b->related_breakpoint = b_return;
996 }
997}
998
999/* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
1000
1001static void
1002elf_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
1003{
1004 struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
1005 struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
1006 struct type *value_type = TYPE_TARGET_TYPE (func_func_type);
1007 struct regcache *regcache = get_thread_regcache (inferior_ptid);
1008 struct value *value;
1009 CORE_ADDR resolved_address, resolved_pc;
1010 struct symtab_and_line sal;
1011 struct symtabs_and_lines sals, sals_end;
1012
1013 gdb_assert (b->type == bp_gnu_ifunc_resolver_return);
1014
1015 value = allocate_value (value_type);
1016 gdbarch_return_value (gdbarch, func_func_type, value_type, regcache,
1017 value_contents_raw (value), NULL);
1018 resolved_address = value_as_address (value);
1019 resolved_pc = gdbarch_convert_from_func_ptr_addr (gdbarch,
1020 resolved_address,
1021 &current_target);
1022
1023 while (b->related_breakpoint != b)
1024 {
1025 struct breakpoint *b_next = b->related_breakpoint;
1026
1027 switch (b->type)
1028 {
1029 case bp_gnu_ifunc_resolver:
1030 break;
1031 case bp_gnu_ifunc_resolver_return:
1032 delete_breakpoint (b);
1033 break;
1034 default:
1035 internal_error (__FILE__, __LINE__,
1036 _("handle_inferior_event: Invalid "
1037 "gnu-indirect-function breakpoint type %d"),
1038 (int) b->type);
1039 }
1040 b = b_next;
1041 }
1042 gdb_assert (b->type == bp_gnu_ifunc_resolver);
1043
1044 gdb_assert (current_program_space == b->pspace);
1045 elf_gnu_ifunc_record_cache (b->addr_string, resolved_pc);
1046
1047 sal = find_pc_line (resolved_pc, 0);
1048 sals.nelts = 1;
1049 sals.sals = &sal;
1050 sals_end.nelts = 0;
1051
1052 b->type = bp_breakpoint;
1053 update_breakpoint_locations (b, sals, sals_end);
1054}
1055
cf7f2e2d
JM
1056struct build_id
1057 {
1058 size_t size;
1059 gdb_byte data[1];
1060 };
1061
1062/* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
1063
1064static struct build_id *
1065build_id_bfd_get (bfd *abfd)
1066{
1067 struct build_id *retval;
1068
1069 if (!bfd_check_format (abfd, bfd_object)
1070 || bfd_get_flavour (abfd) != bfd_target_elf_flavour
1071 || elf_tdata (abfd)->build_id == NULL)
1072 return NULL;
1073
1074 retval = xmalloc (sizeof *retval - 1 + elf_tdata (abfd)->build_id_size);
1075 retval->size = elf_tdata (abfd)->build_id_size;
1076 memcpy (retval->data, elf_tdata (abfd)->build_id, retval->size);
1077
1078 return retval;
1079}
1080
1081/* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
1082
1083static int
1084build_id_verify (const char *filename, struct build_id *check)
1085{
1086 bfd *abfd;
1087 struct build_id *found = NULL;
1088 int retval = 0;
1089
1090 /* We expect to be silent on the non-existing files. */
1091 abfd = bfd_open_maybe_remote (filename);
1092 if (abfd == NULL)
1093 return 0;
1094
1095 found = build_id_bfd_get (abfd);
1096
1097 if (found == NULL)
1098 warning (_("File \"%s\" has no build-id, file skipped"), filename);
1099 else if (found->size != check->size
1100 || memcmp (found->data, check->data, found->size) != 0)
c50c785c
JM
1101 warning (_("File \"%s\" has a different build-id, file skipped"),
1102 filename);
cf7f2e2d
JM
1103 else
1104 retval = 1;
1105
1106 gdb_bfd_close_or_warn (abfd);
1107
1108 xfree (found);
1109
1110 return retval;
1111}
1112
1113static char *
1114build_id_to_debug_filename (struct build_id *build_id)
1115{
1116 char *link, *debugdir, *retval = NULL;
1117
1118 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
1119 link = alloca (strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
1120 + 2 * build_id->size + (sizeof ".debug" - 1) + 1);
1121
1122 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
1123 cause "/.build-id/..." lookups. */
1124
1125 debugdir = debug_file_directory;
1126 do
1127 {
1128 char *s, *debugdir_end;
1129 gdb_byte *data = build_id->data;
1130 size_t size = build_id->size;
1131
1132 while (*debugdir == DIRNAME_SEPARATOR)
1133 debugdir++;
1134
1135 debugdir_end = strchr (debugdir, DIRNAME_SEPARATOR);
1136 if (debugdir_end == NULL)
1137 debugdir_end = &debugdir[strlen (debugdir)];
1138
1139 memcpy (link, debugdir, debugdir_end - debugdir);
1140 s = &link[debugdir_end - debugdir];
1141 s += sprintf (s, "/.build-id/");
1142 if (size > 0)
1143 {
1144 size--;
1145 s += sprintf (s, "%02x", (unsigned) *data++);
1146 }
1147 if (size > 0)
1148 *s++ = '/';
1149 while (size-- > 0)
1150 s += sprintf (s, "%02x", (unsigned) *data++);
1151 strcpy (s, ".debug");
1152
1153 /* lrealpath() is expensive even for the usually non-existent files. */
1154 if (access (link, F_OK) == 0)
1155 retval = lrealpath (link);
1156
1157 if (retval != NULL && !build_id_verify (retval, build_id))
1158 {
1159 xfree (retval);
1160 retval = NULL;
1161 }
1162
1163 if (retval != NULL)
1164 break;
1165
1166 debugdir = debugdir_end;
1167 }
1168 while (*debugdir != 0);
1169
1170 return retval;
1171}
1172
1173static char *
1174find_separate_debug_file_by_buildid (struct objfile *objfile)
1175{
1176 struct build_id *build_id;
1177
1178 build_id = build_id_bfd_get (objfile->obfd);
1179 if (build_id != NULL)
1180 {
1181 char *build_id_name;
1182
1183 build_id_name = build_id_to_debug_filename (build_id);
1184 xfree (build_id);
1185 /* Prevent looping on a stripped .debug file. */
c50c785c
JM
1186 if (build_id_name != NULL
1187 && filename_cmp (build_id_name, objfile->name) == 0)
cf7f2e2d
JM
1188 {
1189 warning (_("\"%s\": separate debug info file has no debug info"),
1190 build_id_name);
1191 xfree (build_id_name);
1192 }
1193 else if (build_id_name != NULL)
1194 return build_id_name;
1195 }
1196 return NULL;
1197}
1198
5796c8dc
SS
1199/* Scan and build partial symbols for a symbol file.
1200 We have been initialized by a call to elf_symfile_init, which
1201 currently does nothing.
1202
1203 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
1204 in each section. We simplify it down to a single offset for all
1205 symbols. FIXME.
1206
5796c8dc
SS
1207 This function only does the minimum work necessary for letting the
1208 user "name" things symbolically; it does not read the entire symtab.
1209 Instead, it reads the external and static symbols and puts them in partial
1210 symbol tables. When more extensive information is requested of a
1211 file, the corresponding partial symbol table is mutated into a full
1212 fledged symbol table by going back and reading the symbols
1213 for real.
1214
1215 We look for sections with specific names, to tell us what debug
1216 format to look for: FIXME!!!
1217
1218 elfstab_build_psymtabs() handles STABS symbols;
1219 mdebug_build_psymtabs() handles ECOFF debugging information.
1220
1221 Note that ELF files have a "minimal" symbol table, which looks a lot
1222 like a COFF symbol table, but has only the minimal information necessary
1223 for linking. We process this also, and use the information to
1224 build gdb's minimal symbol table. This gives us some minimal debugging
1225 capability even for files compiled without -g. */
1226
1227static void
cf7f2e2d 1228elf_symfile_read (struct objfile *objfile, int symfile_flags)
5796c8dc
SS
1229{
1230 bfd *abfd = objfile->obfd;
1231 struct elfinfo ei;
1232 struct cleanup *back_to;
5796c8dc
SS
1233 long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
1234 asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
1235 asymbol *synthsyms;
1236
1237 init_minimal_symbol_collection ();
1238 back_to = make_cleanup_discard_minimal_symbols ();
1239
1240 memset ((char *) &ei, 0, sizeof (ei));
1241
c50c785c 1242 /* Allocate struct to keep track of the symfile. */
5796c8dc
SS
1243 objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *)
1244 xmalloc (sizeof (struct dbx_symfile_info));
c50c785c
JM
1245 memset ((char *) objfile->deprecated_sym_stab_info,
1246 0, sizeof (struct dbx_symfile_info));
5796c8dc
SS
1247 make_cleanup (free_elfinfo, (void *) objfile);
1248
c50c785c
JM
1249 /* Process the normal ELF symbol table first. This may write some
1250 chain of info into the dbx_symfile_info in
1251 objfile->deprecated_sym_stab_info, which can later be used by
1252 elfstab_offset_sections. */
5796c8dc
SS
1253
1254 storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
1255 if (storage_needed < 0)
c50c785c
JM
1256 error (_("Can't read symbols from %s: %s"),
1257 bfd_get_filename (objfile->obfd),
5796c8dc
SS
1258 bfd_errmsg (bfd_get_error ()));
1259
1260 if (storage_needed > 0)
1261 {
1262 symbol_table = (asymbol **) xmalloc (storage_needed);
1263 make_cleanup (xfree, symbol_table);
1264 symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
1265
1266 if (symcount < 0)
c50c785c
JM
1267 error (_("Can't read symbols from %s: %s"),
1268 bfd_get_filename (objfile->obfd),
5796c8dc
SS
1269 bfd_errmsg (bfd_get_error ()));
1270
cf7f2e2d 1271 elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table, 0);
5796c8dc
SS
1272 }
1273
1274 /* Add the dynamic symbols. */
1275
1276 storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd);
1277
1278 if (storage_needed > 0)
1279 {
c50c785c
JM
1280 /* Memory gets permanently referenced from ABFD after
1281 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
1282 It happens only in the case when elf_slurp_reloc_table sees
1283 asection->relocation NULL. Determining which section is asection is
1284 done by _bfd_elf_get_synthetic_symtab which is all a bfd
1285 implementation detail, though. */
1286
1287 dyn_symbol_table = bfd_alloc (abfd, storage_needed);
5796c8dc
SS
1288 dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
1289 dyn_symbol_table);
1290
1291 if (dynsymcount < 0)
c50c785c
JM
1292 error (_("Can't read symbols from %s: %s"),
1293 bfd_get_filename (objfile->obfd),
5796c8dc
SS
1294 bfd_errmsg (bfd_get_error ()));
1295
cf7f2e2d 1296 elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table, 0);
c50c785c
JM
1297
1298 elf_rel_plt_read (objfile, dyn_symbol_table);
5796c8dc
SS
1299 }
1300
1301 /* Add synthetic symbols - for instance, names for any PLT entries. */
1302
1303 synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table,
1304 dynsymcount, dyn_symbol_table,
1305 &synthsyms);
1306 if (synthcount > 0)
1307 {
1308 asymbol **synth_symbol_table;
1309 long i;
1310
1311 make_cleanup (xfree, synthsyms);
1312 synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount);
1313 for (i = 0; i < synthcount; i++)
1314 synth_symbol_table[i] = synthsyms + i;
1315 make_cleanup (xfree, synth_symbol_table);
c50c785c
JM
1316 elf_symtab_read (objfile, ST_SYNTHETIC, synthcount,
1317 synth_symbol_table, 1);
5796c8dc
SS
1318 }
1319
1320 /* Install any minimal symbols that have been collected as the current
1321 minimal symbols for this objfile. The debug readers below this point
1322 should not generate new minimal symbols; if they do it's their
1323 responsibility to install them. "mdebug" appears to be the only one
1324 which will do this. */
1325
1326 install_minimal_symbols (objfile);
1327 do_cleanups (back_to);
1328
1329 /* Now process debugging information, which is contained in
c50c785c 1330 special ELF sections. */
5796c8dc 1331
c50c785c 1332 /* We first have to find them... */
5796c8dc
SS
1333 bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
1334
1335 /* ELF debugging information is inserted into the psymtab in the
1336 order of least informative first - most informative last. Since
1337 the psymtab table is searched `most recent insertion first' this
1338 increases the probability that more detailed debug information
1339 for a section is found.
1340
1341 For instance, an object file might contain both .mdebug (XCOFF)
1342 and .debug_info (DWARF2) sections then .mdebug is inserted first
1343 (searched last) and DWARF2 is inserted last (searched first). If
1344 we don't do this then the XCOFF info is found first - for code in
c50c785c 1345 an included file XCOFF info is useless. */
5796c8dc
SS
1346
1347 if (ei.mdebugsect)
1348 {
1349 const struct ecoff_debug_swap *swap;
1350
1351 /* .mdebug section, presumably holding ECOFF debugging
1352 information. */
1353 swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap;
1354 if (swap)
1355 elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect);
1356 }
1357 if (ei.stabsect)
1358 {
1359 asection *str_sect;
1360
1361 /* Stab sections have an associated string table that looks like
1362 a separate section. */
1363 str_sect = bfd_get_section_by_name (abfd, ".stabstr");
1364
1365 /* FIXME should probably warn about a stab section without a stabstr. */
1366 if (str_sect)
1367 elfstab_build_psymtabs (objfile,
5796c8dc
SS
1368 ei.stabsect,
1369 str_sect->filepos,
1370 bfd_section_size (abfd, str_sect));
1371 }
c50c785c 1372
5796c8dc
SS
1373 if (dwarf2_has_info (objfile))
1374 {
c50c785c
JM
1375 /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
1376 information present in OBJFILE. If there is such debug info present
1377 never use .gdb_index. */
1378
1379 if (!objfile_has_partial_symbols (objfile)
1380 && dwarf2_initialize_objfile (objfile))
1381 objfile->sf = &elf_sym_fns_gdb_index;
1382 else
1383 {
1384 /* It is ok to do this even if the stabs reader made some
1385 partial symbols, because OBJF_PSYMTABS_READ has not been
1386 set, and so our lazy reader function will still be called
1387 when needed. */
1388 objfile->sf = &elf_sym_fns_lazy_psyms;
1389 }
5796c8dc 1390 }
c50c785c
JM
1391 /* If the file has its own symbol tables it has no separate debug
1392 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
1393 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
1394 `.note.gnu.build-id'. */
1395 else if (!objfile_has_partial_symbols (objfile))
cf7f2e2d
JM
1396 {
1397 char *debugfile;
1398
1399 debugfile = find_separate_debug_file_by_buildid (objfile);
1400
1401 if (debugfile == NULL)
1402 debugfile = find_separate_debug_file_by_debuglink (objfile);
1403
1404 if (debugfile)
1405 {
1406 bfd *abfd = symfile_bfd_open (debugfile);
1407
1408 symbol_file_add_separate (abfd, symfile_flags, objfile);
1409 xfree (debugfile);
1410 }
1411 }
5796c8dc
SS
1412}
1413
c50c785c
JM
1414/* Callback to lazily read psymtabs. */
1415
1416static void
1417read_psyms (struct objfile *objfile)
1418{
1419 if (dwarf2_has_info (objfile))
1420 dwarf2_build_psymtabs (objfile);
1421}
1422
5796c8dc
SS
1423/* This cleans up the objfile's deprecated_sym_stab_info pointer, and
1424 the chain of stab_section_info's, that might be dangling from
1425 it. */
1426
1427static void
1428free_elfinfo (void *objp)
1429{
1430 struct objfile *objfile = (struct objfile *) objp;
1431 struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info;
1432 struct stab_section_info *ssi, *nssi;
1433
1434 ssi = dbxinfo->stab_section_info;
1435 while (ssi)
1436 {
1437 nssi = ssi->next;
1438 xfree (ssi);
1439 ssi = nssi;
1440 }
1441
1442 dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */
1443}
1444
1445
1446/* Initialize anything that needs initializing when a completely new symbol
1447 file is specified (not just adding some symbols from another file, e.g. a
1448 shared library).
1449
c50c785c
JM
1450 We reinitialize buildsym, since we may be reading stabs from an ELF
1451 file. */
5796c8dc
SS
1452
1453static void
1454elf_new_init (struct objfile *ignore)
1455{
1456 stabsread_new_init ();
1457 buildsym_new_init ();
1458}
1459
1460/* Perform any local cleanups required when we are done with a particular
1461 objfile. I.E, we are in the process of discarding all symbol information
1462 for an objfile, freeing up all memory held for it, and unlinking the
c50c785c 1463 objfile struct from the global list of known objfiles. */
5796c8dc
SS
1464
1465static void
1466elf_symfile_finish (struct objfile *objfile)
1467{
1468 if (objfile->deprecated_sym_stab_info != NULL)
1469 {
1470 xfree (objfile->deprecated_sym_stab_info);
1471 }
1472
1473 dwarf2_free_objfile (objfile);
1474}
1475
1476/* ELF specific initialization routine for reading symbols.
1477
1478 It is passed a pointer to a struct sym_fns which contains, among other
1479 things, the BFD for the file whose symbols are being read, and a slot for
1480 a pointer to "private data" which we can fill with goodies.
1481
1482 For now at least, we have nothing in particular to do, so this function is
c50c785c 1483 just a stub. */
5796c8dc
SS
1484
1485static void
1486elf_symfile_init (struct objfile *objfile)
1487{
1488 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1489 find this causes a significant slowdown in gdb then we could
1490 set it in the debug symbol readers only when necessary. */
1491 objfile->flags |= OBJF_REORDERED;
1492}
1493
1494/* When handling an ELF file that contains Sun STABS debug info,
1495 some of the debug info is relative to the particular chunk of the
1496 section that was generated in its individual .o file. E.g.
1497 offsets to static variables are relative to the start of the data
1498 segment *for that module before linking*. This information is
1499 painfully squirreled away in the ELF symbol table as local symbols
1500 with wierd names. Go get 'em when needed. */
1501
1502void
1503elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst)
1504{
c50c785c 1505 const char *filename = pst->filename;
5796c8dc
SS
1506 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
1507 struct stab_section_info *maybe = dbx->stab_section_info;
1508 struct stab_section_info *questionable = 0;
1509 int i;
5796c8dc
SS
1510
1511 /* The ELF symbol info doesn't include path names, so strip the path
1512 (if any) from the psymtab filename. */
c50c785c 1513 filename = lbasename (filename);
5796c8dc
SS
1514
1515 /* FIXME: This linear search could speed up significantly
1516 if it was chained in the right order to match how we search it,
c50c785c 1517 and if we unchained when we found a match. */
5796c8dc
SS
1518 for (; maybe; maybe = maybe->next)
1519 {
1520 if (filename[0] == maybe->filename[0]
c50c785c 1521 && filename_cmp (filename, maybe->filename) == 0)
5796c8dc
SS
1522 {
1523 /* We found a match. But there might be several source files
1524 (from different directories) with the same name. */
1525 if (0 == maybe->found)
1526 break;
1527 questionable = maybe; /* Might use it later. */
1528 }
1529 }
1530
1531 if (maybe == 0 && questionable != 0)
1532 {
1533 complaint (&symfile_complaints,
c50c785c
JM
1534 _("elf/stab section information questionable for %s"),
1535 filename);
5796c8dc
SS
1536 maybe = questionable;
1537 }
1538
1539 if (maybe)
1540 {
1541 /* Found it! Allocate a new psymtab struct, and fill it in. */
1542 maybe->found++;
1543 pst->section_offsets = (struct section_offsets *)
1544 obstack_alloc (&objfile->objfile_obstack,
1545 SIZEOF_N_SECTION_OFFSETS (objfile->num_sections));
1546 for (i = 0; i < maybe->num_sections; i++)
1547 (pst->section_offsets)->offsets[i] = maybe->sections[i];
1548 return;
1549 }
1550
1551 /* We were unable to find any offsets for this file. Complain. */
1552 if (dbx->stab_section_info) /* If there *is* any info, */
1553 complaint (&symfile_complaints,
1554 _("elf/stab section information missing for %s"), filename);
1555}
1556\f
1557/* Register that we are able to handle ELF object file formats. */
1558
c50c785c 1559static const struct sym_fns elf_sym_fns =
5796c8dc
SS
1560{
1561 bfd_target_elf_flavour,
c50c785c
JM
1562 elf_new_init, /* init anything gbl to entire symtab */
1563 elf_symfile_init, /* read initial info, setup for sym_read() */
1564 elf_symfile_read, /* read a symbol file into symtab */
1565 NULL, /* sym_read_psymbols */
1566 elf_symfile_finish, /* finished with file, cleanup */
1567 default_symfile_offsets, /* Translate ext. to int. relocation */
1568 elf_symfile_segments, /* Get segment information from a file. */
1569 NULL,
1570 default_symfile_relocate, /* Relocate a debug section. */
1571 &psym_functions
1572};
1573
1574/* The same as elf_sym_fns, but not registered and lazily reads
1575 psymbols. */
1576
1577static const struct sym_fns elf_sym_fns_lazy_psyms =
1578{
1579 bfd_target_elf_flavour,
1580 elf_new_init, /* init anything gbl to entire symtab */
1581 elf_symfile_init, /* read initial info, setup for sym_read() */
1582 elf_symfile_read, /* read a symbol file into symtab */
1583 read_psyms, /* sym_read_psymbols */
1584 elf_symfile_finish, /* finished with file, cleanup */
1585 default_symfile_offsets, /* Translate ext. to int. relocation */
1586 elf_symfile_segments, /* Get segment information from a file. */
1587 NULL,
1588 default_symfile_relocate, /* Relocate a debug section. */
1589 &psym_functions
1590};
1591
1592/* The same as elf_sym_fns, but not registered and uses the
1593 DWARF-specific GNU index rather than psymtab. */
1594static const struct sym_fns elf_sym_fns_gdb_index =
1595{
1596 bfd_target_elf_flavour,
1597 elf_new_init, /* init anything gbl to entire symab */
1598 elf_symfile_init, /* read initial info, setup for sym_red() */
1599 elf_symfile_read, /* read a symbol file into symtab */
1600 NULL, /* sym_read_psymbols */
1601 elf_symfile_finish, /* finished with file, cleanup */
1602 default_symfile_offsets, /* Translate ext. to int. relocatin */
1603 elf_symfile_segments, /* Get segment information from a file. */
1604 NULL,
1605 default_symfile_relocate, /* Relocate a debug section. */
1606 &dwarf2_gdb_index_functions
1607};
1608
1609/* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
1610
1611static const struct gnu_ifunc_fns elf_gnu_ifunc_fns =
1612{
1613 elf_gnu_ifunc_resolve_addr,
1614 elf_gnu_ifunc_resolve_name,
1615 elf_gnu_ifunc_resolver_stop,
1616 elf_gnu_ifunc_resolver_return_stop
5796c8dc
SS
1617};
1618
1619void
1620_initialize_elfread (void)
1621{
1622 add_symtab_fns (&elf_sym_fns);
c50c785c
JM
1623
1624 elf_objfile_gnu_ifunc_cache_data = register_objfile_data ();
1625 gnu_ifunc_fns_p = &elf_gnu_ifunc_fns;
5796c8dc 1626}