gdb vendor branch: Bring in additional source files
[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
a45ae5f8 3 Copyright (C) 1991-2012 Free Software Foundation, Inc.
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4
5 Written by Fred Fish at Cygnus Support.
6
7 This file is part of GDB.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21
22#include "defs.h"
23#include "bfd.h"
24#include "gdb_string.h"
25#include "elf-bfd.h"
26#include "elf/common.h"
27#include "elf/internal.h"
28#include "elf/mips.h"
29#include "symtab.h"
30#include "symfile.h"
31#include "objfiles.h"
32#include "buildsym.h"
33#include "stabsread.h"
34#include "gdb-stabs.h"
35#include "complaints.h"
36#include "demangle.h"
cf7f2e2d 37#include "psympriv.h"
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JM
38#include "filenames.h"
39#include "gdbtypes.h"
40#include "value.h"
41#include "infcall.h"
42#include "gdbthread.h"
43#include "regcache.h"
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44
45extern void _initialize_elfread (void);
46
c50c785c
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47/* Forward declarations. */
48static const struct sym_fns elf_sym_fns_gdb_index;
49static const struct sym_fns elf_sym_fns_lazy_psyms;
50
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51/* The struct elfinfo is available only during ELF symbol table and
52 psymtab reading. It is destroyed at the completion of psymtab-reading.
53 It's local to elf_symfile_read. */
54
55struct elfinfo
56 {
57 asection *stabsect; /* Section pointer for .stab section */
58 asection *stabindexsect; /* Section pointer for .stab.index section */
59 asection *mdebugsect; /* Section pointer for .mdebug section */
60 };
61
62static void free_elfinfo (void *);
63
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JM
64/* Minimal symbols located at the GOT entries for .plt - that is the real
65 pointer where the given entry will jump to. It gets updated by the real
66 function address during lazy ld.so resolving in the inferior. These
67 minimal symbols are indexed for <tab>-completion. */
68
69#define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
70
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71/* Locate the segments in ABFD. */
72
73static struct symfile_segment_data *
74elf_symfile_segments (bfd *abfd)
75{
76 Elf_Internal_Phdr *phdrs, **segments;
77 long phdrs_size;
78 int num_phdrs, num_segments, num_sections, i;
79 asection *sect;
80 struct symfile_segment_data *data;
81
82 phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
83 if (phdrs_size == -1)
84 return NULL;
85
86 phdrs = alloca (phdrs_size);
87 num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
88 if (num_phdrs == -1)
89 return NULL;
90
91 num_segments = 0;
92 segments = alloca (sizeof (Elf_Internal_Phdr *) * num_phdrs);
93 for (i = 0; i < num_phdrs; i++)
94 if (phdrs[i].p_type == PT_LOAD)
95 segments[num_segments++] = &phdrs[i];
96
97 if (num_segments == 0)
98 return NULL;
99
100 data = XZALLOC (struct symfile_segment_data);
101 data->num_segments = num_segments;
102 data->segment_bases = XCALLOC (num_segments, CORE_ADDR);
103 data->segment_sizes = XCALLOC (num_segments, CORE_ADDR);
104
105 for (i = 0; i < num_segments; i++)
106 {
107 data->segment_bases[i] = segments[i]->p_vaddr;
108 data->segment_sizes[i] = segments[i]->p_memsz;
109 }
110
111 num_sections = bfd_count_sections (abfd);
112 data->segment_info = XCALLOC (num_sections, int);
113
114 for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next)
115 {
116 int j;
117 CORE_ADDR vma;
118
119 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
120 continue;
121
122 vma = bfd_get_section_vma (abfd, sect);
123
124 for (j = 0; j < num_segments; j++)
125 if (segments[j]->p_memsz > 0
126 && vma >= segments[j]->p_vaddr
127 && (vma - segments[j]->p_vaddr) < segments[j]->p_memsz)
128 {
129 data->segment_info[i] = j + 1;
130 break;
131 }
132
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133 /* We should have found a segment for every non-empty section.
134 If we haven't, we will not relocate this section by any
135 offsets we apply to the segments. As an exception, do not
136 warn about SHT_NOBITS sections; in normal ELF execution
137 environments, SHT_NOBITS means zero-initialized and belongs
138 in a segment, but in no-OS environments some tools (e.g. ARM
139 RealView) use SHT_NOBITS for uninitialized data. Since it is
140 uninitialized, it doesn't need a program header. Such
141 binaries are not relocatable. */
142 if (bfd_get_section_size (sect) > 0 && j == num_segments
143 && (bfd_get_section_flags (abfd, sect) & SEC_LOAD) != 0)
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144 warning (_("Loadable segment \"%s\" outside of ELF segments"),
145 bfd_section_name (abfd, sect));
146 }
147
148 return data;
149}
150
151/* We are called once per section from elf_symfile_read. We
152 need to examine each section we are passed, check to see
153 if it is something we are interested in processing, and
154 if so, stash away some access information for the section.
155
156 For now we recognize the dwarf debug information sections and
157 line number sections from matching their section names. The
158 ELF definition is no real help here since it has no direct
159 knowledge of DWARF (by design, so any debugging format can be
160 used).
161
162 We also recognize the ".stab" sections used by the Sun compilers
163 released with Solaris 2.
164
165 FIXME: The section names should not be hardwired strings (what
166 should they be? I don't think most object file formats have enough
c50c785c 167 section flags to specify what kind of debug section it is.
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168 -kingdon). */
169
170static void
171elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip)
172{
173 struct elfinfo *ei;
174
175 ei = (struct elfinfo *) eip;
176 if (strcmp (sectp->name, ".stab") == 0)
177 {
178 ei->stabsect = sectp;
179 }
180 else if (strcmp (sectp->name, ".stab.index") == 0)
181 {
182 ei->stabindexsect = sectp;
183 }
184 else if (strcmp (sectp->name, ".mdebug") == 0)
185 {
186 ei->mdebugsect = sectp;
187 }
188}
189
190static struct minimal_symbol *
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191record_minimal_symbol (const char *name, int name_len, int copy_name,
192 CORE_ADDR address,
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193 enum minimal_symbol_type ms_type,
194 asection *bfd_section, struct objfile *objfile)
195{
196 struct gdbarch *gdbarch = get_objfile_arch (objfile);
197
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198 if (ms_type == mst_text || ms_type == mst_file_text
199 || ms_type == mst_text_gnu_ifunc)
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200 address = gdbarch_smash_text_address (gdbarch, address);
201
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202 return prim_record_minimal_symbol_full (name, name_len, copy_name, address,
203 ms_type, bfd_section->index,
204 bfd_section, objfile);
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205}
206
a45ae5f8 207/* Read the symbol table of an ELF file.
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208
209 Given an objfile, a symbol table, and a flag indicating whether the
210 symbol table contains regular, dynamic, or synthetic symbols, add all
211 the global function and data symbols to the minimal symbol table.
212
213 In stabs-in-ELF, as implemented by Sun, there are some local symbols
214 defined in the ELF symbol table, which can be used to locate
215 the beginnings of sections from each ".o" file that was linked to
216 form the executable objfile. We gather any such info and record it
a45ae5f8 217 in data structures hung off the objfile's private data. */
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218
219#define ST_REGULAR 0
220#define ST_DYNAMIC 1
221#define ST_SYNTHETIC 2
222
223static void
224elf_symtab_read (struct objfile *objfile, int type,
cf7f2e2d
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225 long number_of_symbols, asymbol **symbol_table,
226 int copy_names)
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227{
228 struct gdbarch *gdbarch = get_objfile_arch (objfile);
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229 asymbol *sym;
230 long i;
231 CORE_ADDR symaddr;
232 CORE_ADDR offset;
233 enum minimal_symbol_type ms_type;
234 /* If sectinfo is nonNULL, it contains section info that should end up
235 filed in the objfile. */
236 struct stab_section_info *sectinfo = NULL;
237 /* If filesym is nonzero, it points to a file symbol, but we haven't
238 seen any section info for it yet. */
239 asymbol *filesym = 0;
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240 /* Name of filesym. This is either a constant string or is saved on
241 the objfile's obstack. */
242 char *filesymname = "";
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243 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
244 int stripped = (bfd_get_symcount (objfile->obfd) == 0);
245
246 for (i = 0; i < number_of_symbols; i++)
247 {
248 sym = symbol_table[i];
249 if (sym->name == NULL || *sym->name == '\0')
250 {
251 /* Skip names that don't exist (shouldn't happen), or names
c50c785c 252 that are null strings (may happen). */
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253 continue;
254 }
255
256 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
257 symbols which do not correspond to objects in the symbol table,
258 but have some other target-specific meaning. */
259 if (bfd_is_target_special_symbol (objfile->obfd, sym))
260 {
261 if (gdbarch_record_special_symbol_p (gdbarch))
262 gdbarch_record_special_symbol (gdbarch, objfile, sym);
263 continue;
264 }
265
266 offset = ANOFFSET (objfile->section_offsets, sym->section->index);
267 if (type == ST_DYNAMIC
268 && sym->section == &bfd_und_section
269 && (sym->flags & BSF_FUNCTION))
270 {
271 struct minimal_symbol *msym;
272 bfd *abfd = objfile->obfd;
a45ae5f8 273 asection *sect;
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274
275 /* Symbol is a reference to a function defined in
276 a shared library.
277 If its value is non zero then it is usually the address
278 of the corresponding entry in the procedure linkage table,
279 plus the desired section offset.
280 If its value is zero then the dynamic linker has to resolve
c50c785c 281 the symbol. We are unable to find any meaningful address
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282 for this symbol in the executable file, so we skip it. */
283 symaddr = sym->value;
284 if (symaddr == 0)
285 continue;
286
287 /* sym->section is the undefined section. However, we want to
288 record the section where the PLT stub resides with the
289 minimal symbol. Search the section table for the one that
290 covers the stub's address. */
291 for (sect = abfd->sections; sect != NULL; sect = sect->next)
292 {
293 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
294 continue;
295
296 if (symaddr >= bfd_get_section_vma (abfd, sect)
297 && symaddr < bfd_get_section_vma (abfd, sect)
298 + bfd_get_section_size (sect))
299 break;
300 }
301 if (!sect)
302 continue;
303
304 symaddr += ANOFFSET (objfile->section_offsets, sect->index);
305
306 msym = record_minimal_symbol
cf7f2e2d
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307 (sym->name, strlen (sym->name), copy_names,
308 symaddr, mst_solib_trampoline, sect, objfile);
5796c8dc
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309 if (msym != NULL)
310 msym->filename = filesymname;
311 continue;
312 }
313
314 /* If it is a nonstripped executable, do not enter dynamic
315 symbols, as the dynamic symbol table is usually a subset
316 of the main symbol table. */
317 if (type == ST_DYNAMIC && !stripped)
318 continue;
319 if (sym->flags & BSF_FILE)
320 {
321 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
322 Chain any old one onto the objfile; remember new sym. */
323 if (sectinfo != NULL)
324 {
325 sectinfo->next = dbx->stab_section_info;
326 dbx->stab_section_info = sectinfo;
327 sectinfo = NULL;
328 }
329 filesym = sym;
330 filesymname =
331 obsavestring ((char *) filesym->name, strlen (filesym->name),
332 &objfile->objfile_obstack);
333 }
334 else if (sym->flags & BSF_SECTION_SYM)
335 continue;
336 else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK))
337 {
338 struct minimal_symbol *msym;
339
340 /* Select global/local/weak symbols. Note that bfd puts abs
341 symbols in their own section, so all symbols we are
c50c785c
JM
342 interested in will have a section. */
343 /* Bfd symbols are section relative. */
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344 symaddr = sym->value + sym->section->vma;
345 /* Relocate all non-absolute and non-TLS symbols by the
346 section offset. */
347 if (sym->section != &bfd_abs_section
348 && !(sym->section->flags & SEC_THREAD_LOCAL))
349 {
350 symaddr += offset;
351 }
352 /* For non-absolute symbols, use the type of the section
353 they are relative to, to intuit text/data. Bfd provides
c50c785c 354 no way of figuring this out for absolute symbols. */
5796c8dc
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355 if (sym->section == &bfd_abs_section)
356 {
357 /* This is a hack to get the minimal symbol type
358 right for Irix 5, which has absolute addresses
359 with special section indices for dynamic symbols.
360
361 NOTE: uweigand-20071112: Synthetic symbols do not
362 have an ELF-private part, so do not touch those. */
a45ae5f8 363 unsigned int shndx = type == ST_SYNTHETIC ? 0 :
5796c8dc
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364 ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx;
365
366 switch (shndx)
367 {
368 case SHN_MIPS_TEXT:
369 ms_type = mst_text;
370 break;
371 case SHN_MIPS_DATA:
372 ms_type = mst_data;
373 break;
374 case SHN_MIPS_ACOMMON:
375 ms_type = mst_bss;
376 break;
377 default:
378 ms_type = mst_abs;
379 }
380
381 /* If it is an Irix dynamic symbol, skip section name
c50c785c 382 symbols, relocate all others by section offset. */
5796c8dc
SS
383 if (ms_type != mst_abs)
384 {
385 if (sym->name[0] == '.')
386 continue;
387 symaddr += offset;
388 }
389 }
390 else if (sym->section->flags & SEC_CODE)
391 {
392 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
393 {
c50c785c
JM
394 if (sym->flags & BSF_GNU_INDIRECT_FUNCTION)
395 ms_type = mst_text_gnu_ifunc;
396 else
397 ms_type = mst_text;
5796c8dc 398 }
a45ae5f8
JM
399 /* The BSF_SYNTHETIC check is there to omit ppc64 function
400 descriptors mistaken for static functions starting with 'L'.
401 */
402 else if ((sym->name[0] == '.' && sym->name[1] == 'L'
403 && (sym->flags & BSF_SYNTHETIC) == 0)
5796c8dc
SS
404 || ((sym->flags & BSF_LOCAL)
405 && sym->name[0] == '$'
406 && sym->name[1] == 'L'))
407 /* Looks like a compiler-generated label. Skip
408 it. The assembler should be skipping these (to
409 keep executables small), but apparently with
410 gcc on the (deleted) delta m88k SVR4, it loses.
411 So to have us check too should be harmless (but
412 I encourage people to fix this in the assembler
413 instead of adding checks here). */
414 continue;
415 else
416 {
417 ms_type = mst_file_text;
418 }
419 }
420 else if (sym->section->flags & SEC_ALLOC)
421 {
422 if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
423 {
424 if (sym->section->flags & SEC_LOAD)
425 {
426 ms_type = mst_data;
427 }
428 else
429 {
430 ms_type = mst_bss;
431 }
432 }
433 else if (sym->flags & BSF_LOCAL)
434 {
435 /* Named Local variable in a Data section.
436 Check its name for stabs-in-elf. */
437 int special_local_sect;
cf7f2e2d 438
5796c8dc
SS
439 if (strcmp ("Bbss.bss", sym->name) == 0)
440 special_local_sect = SECT_OFF_BSS (objfile);
441 else if (strcmp ("Ddata.data", sym->name) == 0)
442 special_local_sect = SECT_OFF_DATA (objfile);
443 else if (strcmp ("Drodata.rodata", sym->name) == 0)
444 special_local_sect = SECT_OFF_RODATA (objfile);
445 else
446 special_local_sect = -1;
447 if (special_local_sect >= 0)
448 {
449 /* Found a special local symbol. Allocate a
450 sectinfo, if needed, and fill it in. */
451 if (sectinfo == NULL)
452 {
453 int max_index;
454 size_t size;
455
456 max_index = SECT_OFF_BSS (objfile);
457 if (objfile->sect_index_data > max_index)
458 max_index = objfile->sect_index_data;
459 if (objfile->sect_index_rodata > max_index)
460 max_index = objfile->sect_index_rodata;
461
462 /* max_index is the largest index we'll
463 use into this array, so we must
464 allocate max_index+1 elements for it.
465 However, 'struct stab_section_info'
466 already includes one element, so we
467 need to allocate max_index aadditional
468 elements. */
a45ae5f8 469 size = (sizeof (struct stab_section_info)
c50c785c 470 + (sizeof (CORE_ADDR) * max_index));
5796c8dc
SS
471 sectinfo = (struct stab_section_info *)
472 xmalloc (size);
473 memset (sectinfo, 0, size);
474 sectinfo->num_sections = max_index;
475 if (filesym == NULL)
476 {
477 complaint (&symfile_complaints,
c50c785c
JM
478 _("elf/stab section information %s "
479 "without a preceding file symbol"),
5796c8dc
SS
480 sym->name);
481 }
482 else
483 {
484 sectinfo->filename =
485 (char *) filesym->name;
486 }
487 }
488 if (sectinfo->sections[special_local_sect] != 0)
489 complaint (&symfile_complaints,
c50c785c
JM
490 _("duplicated elf/stab section "
491 "information for %s"),
5796c8dc
SS
492 sectinfo->filename);
493 /* BFD symbols are section relative. */
494 symaddr = sym->value + sym->section->vma;
495 /* Relocate non-absolute symbols by the
496 section offset. */
497 if (sym->section != &bfd_abs_section)
498 symaddr += offset;
499 sectinfo->sections[special_local_sect] = symaddr;
500 /* The special local symbols don't go in the
501 minimal symbol table, so ignore this one. */
502 continue;
503 }
504 /* Not a special stabs-in-elf symbol, do regular
505 symbol processing. */
506 if (sym->section->flags & SEC_LOAD)
507 {
508 ms_type = mst_file_data;
509 }
510 else
511 {
512 ms_type = mst_file_bss;
513 }
514 }
515 else
516 {
517 ms_type = mst_unknown;
518 }
519 }
520 else
521 {
522 /* FIXME: Solaris2 shared libraries include lots of
a45ae5f8 523 odd "absolute" and "undefined" symbols, that play
5796c8dc
SS
524 hob with actions like finding what function the PC
525 is in. Ignore them if they aren't text, data, or bss. */
526 /* ms_type = mst_unknown; */
c50c785c 527 continue; /* Skip this symbol. */
5796c8dc
SS
528 }
529 msym = record_minimal_symbol
cf7f2e2d 530 (sym->name, strlen (sym->name), copy_names, symaddr,
5796c8dc
SS
531 ms_type, sym->section, objfile);
532
533 if (msym)
534 {
535 /* Pass symbol size field in via BFD. FIXME!!! */
536 elf_symbol_type *elf_sym;
537
538 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
539 ELF-private part. However, in some cases (e.g. synthetic
540 'dot' symbols on ppc64) the udata.p entry is set to point back
541 to the original ELF symbol it was derived from. Get the size
a45ae5f8 542 from that symbol. */
5796c8dc
SS
543 if (type != ST_SYNTHETIC)
544 elf_sym = (elf_symbol_type *) sym;
545 else
546 elf_sym = (elf_symbol_type *) sym->udata.p;
547
548 if (elf_sym)
549 MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size;
a45ae5f8 550
cf7f2e2d
JM
551 msym->filename = filesymname;
552 gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
5796c8dc 553 }
5796c8dc
SS
554
555 /* For @plt symbols, also record a trampoline to the
556 destination symbol. The @plt symbol will be used in
557 disassembly, and the trampoline will be used when we are
558 trying to find the target. */
559 if (msym && ms_type == mst_text && type == ST_SYNTHETIC)
560 {
561 int len = strlen (sym->name);
562
563 if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
564 {
5796c8dc
SS
565 struct minimal_symbol *mtramp;
566
cf7f2e2d
JM
567 mtramp = record_minimal_symbol (sym->name, len - 4, 1,
568 symaddr,
5796c8dc
SS
569 mst_solib_trampoline,
570 sym->section, objfile);
571 if (mtramp)
572 {
573 MSYMBOL_SIZE (mtramp) = MSYMBOL_SIZE (msym);
574 mtramp->filename = filesymname;
575 gdbarch_elf_make_msymbol_special (gdbarch, sym, mtramp);
576 }
577 }
578 }
579 }
580 }
581}
582
c50c785c
JM
583/* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
584 for later look ups of which function to call when user requests
585 a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
586 library defining `function' we cannot yet know while reading OBJFILE which
587 of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
588 DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
589
590static void
591elf_rel_plt_read (struct objfile *objfile, asymbol **dyn_symbol_table)
592{
593 bfd *obfd = objfile->obfd;
594 const struct elf_backend_data *bed = get_elf_backend_data (obfd);
595 asection *plt, *relplt, *got_plt;
596 unsigned u;
597 int plt_elf_idx;
598 bfd_size_type reloc_count, reloc;
599 char *string_buffer = NULL;
600 size_t string_buffer_size = 0;
601 struct cleanup *back_to;
602 struct gdbarch *gdbarch = objfile->gdbarch;
603 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
604 size_t ptr_size = TYPE_LENGTH (ptr_type);
605
606 if (objfile->separate_debug_objfile_backlink)
607 return;
608
609 plt = bfd_get_section_by_name (obfd, ".plt");
610 if (plt == NULL)
611 return;
612 plt_elf_idx = elf_section_data (plt)->this_idx;
613
614 got_plt = bfd_get_section_by_name (obfd, ".got.plt");
615 if (got_plt == NULL)
616 return;
617
618 /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
619 for (relplt = obfd->sections; relplt != NULL; relplt = relplt->next)
620 if (elf_section_data (relplt)->this_hdr.sh_info == plt_elf_idx
621 && (elf_section_data (relplt)->this_hdr.sh_type == SHT_REL
622 || elf_section_data (relplt)->this_hdr.sh_type == SHT_RELA))
623 break;
624 if (relplt == NULL)
625 return;
626
627 if (! bed->s->slurp_reloc_table (obfd, relplt, dyn_symbol_table, TRUE))
628 return;
629
630 back_to = make_cleanup (free_current_contents, &string_buffer);
631
632 reloc_count = relplt->size / elf_section_data (relplt)->this_hdr.sh_entsize;
633 for (reloc = 0; reloc < reloc_count; reloc++)
634 {
635 const char *name, *name_got_plt;
636 struct minimal_symbol *msym;
637 CORE_ADDR address;
638 const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
639 size_t name_len;
640
641 name = bfd_asymbol_name (*relplt->relocation[reloc].sym_ptr_ptr);
642 name_len = strlen (name);
643 address = relplt->relocation[reloc].address;
644
645 /* Does the pointer reside in the .got.plt section? */
646 if (!(bfd_get_section_vma (obfd, got_plt) <= address
647 && address < bfd_get_section_vma (obfd, got_plt)
648 + bfd_get_section_size (got_plt)))
649 continue;
650
651 /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
652 OBJFILE the symbol is undefined and the objfile having NAME defined
653 may not yet have been loaded. */
654
a45ae5f8 655 if (string_buffer_size < name_len + got_suffix_len + 1)
c50c785c
JM
656 {
657 string_buffer_size = 2 * (name_len + got_suffix_len);
658 string_buffer = xrealloc (string_buffer, string_buffer_size);
659 }
660 memcpy (string_buffer, name, name_len);
661 memcpy (&string_buffer[name_len], SYMBOL_GOT_PLT_SUFFIX,
a45ae5f8 662 got_suffix_len + 1);
c50c785c
JM
663
664 msym = record_minimal_symbol (string_buffer, name_len + got_suffix_len,
665 1, address, mst_slot_got_plt, got_plt,
666 objfile);
667 if (msym)
668 MSYMBOL_SIZE (msym) = ptr_size;
669 }
670
671 do_cleanups (back_to);
672}
673
674/* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
675
676static const struct objfile_data *elf_objfile_gnu_ifunc_cache_data;
677
678/* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
679
680struct elf_gnu_ifunc_cache
681{
682 /* This is always a function entry address, not a function descriptor. */
683 CORE_ADDR addr;
684
685 char name[1];
686};
687
688/* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
689
690static hashval_t
691elf_gnu_ifunc_cache_hash (const void *a_voidp)
692{
693 const struct elf_gnu_ifunc_cache *a = a_voidp;
694
695 return htab_hash_string (a->name);
696}
697
698/* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
699
700static int
701elf_gnu_ifunc_cache_eq (const void *a_voidp, const void *b_voidp)
702{
703 const struct elf_gnu_ifunc_cache *a = a_voidp;
704 const struct elf_gnu_ifunc_cache *b = b_voidp;
705
706 return strcmp (a->name, b->name) == 0;
707}
708
709/* Record the target function address of a STT_GNU_IFUNC function NAME is the
710 function entry address ADDR. Return 1 if NAME and ADDR are considered as
711 valid and therefore they were successfully recorded, return 0 otherwise.
712
713 Function does not expect a duplicate entry. Use
714 elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
715 exists. */
716
717static int
718elf_gnu_ifunc_record_cache (const char *name, CORE_ADDR addr)
719{
720 struct minimal_symbol *msym;
721 asection *sect;
722 struct objfile *objfile;
723 htab_t htab;
724 struct elf_gnu_ifunc_cache entry_local, *entry_p;
725 void **slot;
726
727 msym = lookup_minimal_symbol_by_pc (addr);
728 if (msym == NULL)
729 return 0;
730 if (SYMBOL_VALUE_ADDRESS (msym) != addr)
731 return 0;
732 /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
733 sect = SYMBOL_OBJ_SECTION (msym)->the_bfd_section;
734 objfile = SYMBOL_OBJ_SECTION (msym)->objfile;
735
736 /* If .plt jumps back to .plt the symbol is still deferred for later
737 resolution and it has no use for GDB. Besides ".text" this symbol can
738 reside also in ".opd" for ppc64 function descriptor. */
739 if (strcmp (bfd_get_section_name (objfile->obfd, sect), ".plt") == 0)
740 return 0;
741
742 htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
743 if (htab == NULL)
744 {
745 htab = htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash,
746 elf_gnu_ifunc_cache_eq,
747 NULL, &objfile->objfile_obstack,
748 hashtab_obstack_allocate,
749 dummy_obstack_deallocate);
750 set_objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data, htab);
751 }
752
753 entry_local.addr = addr;
754 obstack_grow (&objfile->objfile_obstack, &entry_local,
755 offsetof (struct elf_gnu_ifunc_cache, name));
756 obstack_grow_str0 (&objfile->objfile_obstack, name);
757 entry_p = obstack_finish (&objfile->objfile_obstack);
758
759 slot = htab_find_slot (htab, entry_p, INSERT);
760 if (*slot != NULL)
761 {
762 struct elf_gnu_ifunc_cache *entry_found_p = *slot;
763 struct gdbarch *gdbarch = objfile->gdbarch;
764
765 if (entry_found_p->addr != addr)
766 {
767 /* This case indicates buggy inferior program, the resolved address
768 should never change. */
769
770 warning (_("gnu-indirect-function \"%s\" has changed its resolved "
771 "function_address from %s to %s"),
772 name, paddress (gdbarch, entry_found_p->addr),
773 paddress (gdbarch, addr));
774 }
775
776 /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
777 }
778 *slot = entry_p;
779
780 return 1;
781}
782
783/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
784 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
785 is not NULL) and the function returns 1. It returns 0 otherwise.
786
787 Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
788 function. */
789
790static int
791elf_gnu_ifunc_resolve_by_cache (const char *name, CORE_ADDR *addr_p)
792{
793 struct objfile *objfile;
794
795 ALL_PSPACE_OBJFILES (current_program_space, objfile)
796 {
797 htab_t htab;
798 struct elf_gnu_ifunc_cache *entry_p;
799 void **slot;
800
801 htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
802 if (htab == NULL)
803 continue;
804
805 entry_p = alloca (sizeof (*entry_p) + strlen (name));
806 strcpy (entry_p->name, name);
807
808 slot = htab_find_slot (htab, entry_p, NO_INSERT);
809 if (slot == NULL)
810 continue;
811 entry_p = *slot;
812 gdb_assert (entry_p != NULL);
813
814 if (addr_p)
815 *addr_p = entry_p->addr;
816 return 1;
817 }
818
819 return 0;
820}
821
822/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
823 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
824 is not NULL) and the function returns 1. It returns 0 otherwise.
825
826 Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
827 elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
828 prevent cache entries duplicates. */
829
830static int
831elf_gnu_ifunc_resolve_by_got (const char *name, CORE_ADDR *addr_p)
832{
833 char *name_got_plt;
834 struct objfile *objfile;
835 const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
836
837 name_got_plt = alloca (strlen (name) + got_suffix_len + 1);
838 sprintf (name_got_plt, "%s" SYMBOL_GOT_PLT_SUFFIX, name);
839
840 ALL_PSPACE_OBJFILES (current_program_space, objfile)
841 {
842 bfd *obfd = objfile->obfd;
843 struct gdbarch *gdbarch = objfile->gdbarch;
844 struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
845 size_t ptr_size = TYPE_LENGTH (ptr_type);
846 CORE_ADDR pointer_address, addr;
847 asection *plt;
848 gdb_byte *buf = alloca (ptr_size);
849 struct minimal_symbol *msym;
850
851 msym = lookup_minimal_symbol (name_got_plt, NULL, objfile);
852 if (msym == NULL)
853 continue;
854 if (MSYMBOL_TYPE (msym) != mst_slot_got_plt)
855 continue;
856 pointer_address = SYMBOL_VALUE_ADDRESS (msym);
857
858 plt = bfd_get_section_by_name (obfd, ".plt");
859 if (plt == NULL)
860 continue;
861
862 if (MSYMBOL_SIZE (msym) != ptr_size)
863 continue;
864 if (target_read_memory (pointer_address, buf, ptr_size) != 0)
865 continue;
866 addr = extract_typed_address (buf, ptr_type);
867 addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr,
868 &current_target);
869
870 if (addr_p)
871 *addr_p = addr;
872 if (elf_gnu_ifunc_record_cache (name, addr))
873 return 1;
874 }
875
876 return 0;
877}
878
879/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
880 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
881 is not NULL) and the function returns 1. It returns 0 otherwise.
882
883 Both the elf_objfile_gnu_ifunc_cache_data hash table and
884 SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
885
886static int
887elf_gnu_ifunc_resolve_name (const char *name, CORE_ADDR *addr_p)
888{
889 if (elf_gnu_ifunc_resolve_by_cache (name, addr_p))
890 return 1;
a45ae5f8 891
c50c785c
JM
892 if (elf_gnu_ifunc_resolve_by_got (name, addr_p))
893 return 1;
894
895 return 0;
896}
897
898/* Call STT_GNU_IFUNC - a function returning addresss of a real function to
899 call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
900 is the entry point of the resolved STT_GNU_IFUNC target function to call.
901 */
902
903static CORE_ADDR
904elf_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
905{
906 char *name_at_pc;
907 CORE_ADDR start_at_pc, address;
908 struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
909 struct value *function, *address_val;
910
911 /* Try first any non-intrusive methods without an inferior call. */
912
913 if (find_pc_partial_function (pc, &name_at_pc, &start_at_pc, NULL)
914 && start_at_pc == pc)
915 {
916 if (elf_gnu_ifunc_resolve_name (name_at_pc, &address))
917 return address;
918 }
919 else
920 name_at_pc = NULL;
921
922 function = allocate_value (func_func_type);
923 set_value_address (function, pc);
924
925 /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
926 function entry address. ADDRESS may be a function descriptor. */
927
928 address_val = call_function_by_hand (function, 0, NULL);
929 address = value_as_address (address_val);
930 address = gdbarch_convert_from_func_ptr_addr (gdbarch, address,
931 &current_target);
932
933 if (name_at_pc)
934 elf_gnu_ifunc_record_cache (name_at_pc, address);
935
936 return address;
937}
938
939/* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
940
941static void
942elf_gnu_ifunc_resolver_stop (struct breakpoint *b)
943{
944 struct breakpoint *b_return;
945 struct frame_info *prev_frame = get_prev_frame (get_current_frame ());
946 struct frame_id prev_frame_id = get_stack_frame_id (prev_frame);
947 CORE_ADDR prev_pc = get_frame_pc (prev_frame);
948 int thread_id = pid_to_thread_id (inferior_ptid);
949
950 gdb_assert (b->type == bp_gnu_ifunc_resolver);
951
952 for (b_return = b->related_breakpoint; b_return != b;
953 b_return = b_return->related_breakpoint)
954 {
955 gdb_assert (b_return->type == bp_gnu_ifunc_resolver_return);
956 gdb_assert (b_return->loc != NULL && b_return->loc->next == NULL);
957 gdb_assert (frame_id_p (b_return->frame_id));
958
959 if (b_return->thread == thread_id
960 && b_return->loc->requested_address == prev_pc
961 && frame_id_eq (b_return->frame_id, prev_frame_id))
962 break;
963 }
964
965 if (b_return == b)
966 {
967 struct symtab_and_line sal;
968
969 /* No need to call find_pc_line for symbols resolving as this is only
970 a helper breakpointer never shown to the user. */
971
972 init_sal (&sal);
973 sal.pspace = current_inferior ()->pspace;
974 sal.pc = prev_pc;
975 sal.section = find_pc_overlay (sal.pc);
976 sal.explicit_pc = 1;
977 b_return = set_momentary_breakpoint (get_frame_arch (prev_frame), sal,
978 prev_frame_id,
979 bp_gnu_ifunc_resolver_return);
980
981 /* Add new b_return to the ring list b->related_breakpoint. */
982 gdb_assert (b_return->related_breakpoint == b_return);
983 b_return->related_breakpoint = b->related_breakpoint;
984 b->related_breakpoint = b_return;
985 }
986}
987
988/* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
989
990static void
991elf_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
992{
993 struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
994 struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
995 struct type *value_type = TYPE_TARGET_TYPE (func_func_type);
996 struct regcache *regcache = get_thread_regcache (inferior_ptid);
997 struct value *value;
998 CORE_ADDR resolved_address, resolved_pc;
999 struct symtab_and_line sal;
1000 struct symtabs_and_lines sals, sals_end;
1001
1002 gdb_assert (b->type == bp_gnu_ifunc_resolver_return);
1003
1004 value = allocate_value (value_type);
1005 gdbarch_return_value (gdbarch, func_func_type, value_type, regcache,
1006 value_contents_raw (value), NULL);
1007 resolved_address = value_as_address (value);
1008 resolved_pc = gdbarch_convert_from_func_ptr_addr (gdbarch,
1009 resolved_address,
1010 &current_target);
1011
1012 while (b->related_breakpoint != b)
1013 {
1014 struct breakpoint *b_next = b->related_breakpoint;
1015
1016 switch (b->type)
1017 {
1018 case bp_gnu_ifunc_resolver:
1019 break;
1020 case bp_gnu_ifunc_resolver_return:
1021 delete_breakpoint (b);
1022 break;
1023 default:
1024 internal_error (__FILE__, __LINE__,
1025 _("handle_inferior_event: Invalid "
1026 "gnu-indirect-function breakpoint type %d"),
1027 (int) b->type);
1028 }
1029 b = b_next;
1030 }
1031 gdb_assert (b->type == bp_gnu_ifunc_resolver);
1032
a45ae5f8 1033 gdb_assert (current_program_space == b->pspace || b->pspace == NULL);
c50c785c
JM
1034 elf_gnu_ifunc_record_cache (b->addr_string, resolved_pc);
1035
1036 sal = find_pc_line (resolved_pc, 0);
1037 sals.nelts = 1;
1038 sals.sals = &sal;
1039 sals_end.nelts = 0;
1040
1041 b->type = bp_breakpoint;
1042 update_breakpoint_locations (b, sals, sals_end);
1043}
1044
cf7f2e2d
JM
1045struct build_id
1046 {
1047 size_t size;
1048 gdb_byte data[1];
1049 };
1050
1051/* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
1052
1053static struct build_id *
1054build_id_bfd_get (bfd *abfd)
1055{
1056 struct build_id *retval;
1057
1058 if (!bfd_check_format (abfd, bfd_object)
1059 || bfd_get_flavour (abfd) != bfd_target_elf_flavour
1060 || elf_tdata (abfd)->build_id == NULL)
1061 return NULL;
1062
1063 retval = xmalloc (sizeof *retval - 1 + elf_tdata (abfd)->build_id_size);
1064 retval->size = elf_tdata (abfd)->build_id_size;
1065 memcpy (retval->data, elf_tdata (abfd)->build_id, retval->size);
1066
1067 return retval;
1068}
1069
1070/* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
1071
1072static int
1073build_id_verify (const char *filename, struct build_id *check)
1074{
1075 bfd *abfd;
1076 struct build_id *found = NULL;
1077 int retval = 0;
1078
1079 /* We expect to be silent on the non-existing files. */
1080 abfd = bfd_open_maybe_remote (filename);
1081 if (abfd == NULL)
1082 return 0;
1083
1084 found = build_id_bfd_get (abfd);
1085
1086 if (found == NULL)
1087 warning (_("File \"%s\" has no build-id, file skipped"), filename);
1088 else if (found->size != check->size
1089 || memcmp (found->data, check->data, found->size) != 0)
c50c785c
JM
1090 warning (_("File \"%s\" has a different build-id, file skipped"),
1091 filename);
cf7f2e2d
JM
1092 else
1093 retval = 1;
1094
1095 gdb_bfd_close_or_warn (abfd);
1096
1097 xfree (found);
1098
1099 return retval;
1100}
1101
1102static char *
1103build_id_to_debug_filename (struct build_id *build_id)
1104{
1105 char *link, *debugdir, *retval = NULL;
1106
1107 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
1108 link = alloca (strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
1109 + 2 * build_id->size + (sizeof ".debug" - 1) + 1);
1110
1111 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
1112 cause "/.build-id/..." lookups. */
1113
1114 debugdir = debug_file_directory;
1115 do
1116 {
1117 char *s, *debugdir_end;
1118 gdb_byte *data = build_id->data;
1119 size_t size = build_id->size;
1120
1121 while (*debugdir == DIRNAME_SEPARATOR)
1122 debugdir++;
1123
1124 debugdir_end = strchr (debugdir, DIRNAME_SEPARATOR);
1125 if (debugdir_end == NULL)
1126 debugdir_end = &debugdir[strlen (debugdir)];
1127
1128 memcpy (link, debugdir, debugdir_end - debugdir);
1129 s = &link[debugdir_end - debugdir];
1130 s += sprintf (s, "/.build-id/");
1131 if (size > 0)
1132 {
1133 size--;
1134 s += sprintf (s, "%02x", (unsigned) *data++);
1135 }
1136 if (size > 0)
1137 *s++ = '/';
1138 while (size-- > 0)
1139 s += sprintf (s, "%02x", (unsigned) *data++);
1140 strcpy (s, ".debug");
1141
1142 /* lrealpath() is expensive even for the usually non-existent files. */
1143 if (access (link, F_OK) == 0)
1144 retval = lrealpath (link);
1145
1146 if (retval != NULL && !build_id_verify (retval, build_id))
1147 {
1148 xfree (retval);
1149 retval = NULL;
1150 }
1151
1152 if (retval != NULL)
1153 break;
1154
1155 debugdir = debugdir_end;
1156 }
1157 while (*debugdir != 0);
1158
1159 return retval;
1160}
1161
1162static char *
1163find_separate_debug_file_by_buildid (struct objfile *objfile)
1164{
1165 struct build_id *build_id;
1166
1167 build_id = build_id_bfd_get (objfile->obfd);
1168 if (build_id != NULL)
1169 {
1170 char *build_id_name;
1171
1172 build_id_name = build_id_to_debug_filename (build_id);
1173 xfree (build_id);
1174 /* Prevent looping on a stripped .debug file. */
c50c785c
JM
1175 if (build_id_name != NULL
1176 && filename_cmp (build_id_name, objfile->name) == 0)
cf7f2e2d
JM
1177 {
1178 warning (_("\"%s\": separate debug info file has no debug info"),
1179 build_id_name);
1180 xfree (build_id_name);
1181 }
1182 else if (build_id_name != NULL)
1183 return build_id_name;
1184 }
1185 return NULL;
1186}
1187
5796c8dc 1188/* Scan and build partial symbols for a symbol file.
a45ae5f8 1189 We have been initialized by a call to elf_symfile_init, which
5796c8dc
SS
1190 currently does nothing.
1191
1192 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
1193 in each section. We simplify it down to a single offset for all
1194 symbols. FIXME.
1195
5796c8dc
SS
1196 This function only does the minimum work necessary for letting the
1197 user "name" things symbolically; it does not read the entire symtab.
1198 Instead, it reads the external and static symbols and puts them in partial
1199 symbol tables. When more extensive information is requested of a
1200 file, the corresponding partial symbol table is mutated into a full
1201 fledged symbol table by going back and reading the symbols
1202 for real.
1203
1204 We look for sections with specific names, to tell us what debug
1205 format to look for: FIXME!!!
1206
1207 elfstab_build_psymtabs() handles STABS symbols;
1208 mdebug_build_psymtabs() handles ECOFF debugging information.
1209
1210 Note that ELF files have a "minimal" symbol table, which looks a lot
1211 like a COFF symbol table, but has only the minimal information necessary
1212 for linking. We process this also, and use the information to
1213 build gdb's minimal symbol table. This gives us some minimal debugging
1214 capability even for files compiled without -g. */
1215
1216static void
cf7f2e2d 1217elf_symfile_read (struct objfile *objfile, int symfile_flags)
5796c8dc 1218{
a45ae5f8 1219 bfd *synth_abfd, *abfd = objfile->obfd;
5796c8dc
SS
1220 struct elfinfo ei;
1221 struct cleanup *back_to;
5796c8dc
SS
1222 long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
1223 asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
1224 asymbol *synthsyms;
1225
1226 init_minimal_symbol_collection ();
1227 back_to = make_cleanup_discard_minimal_symbols ();
1228
1229 memset ((char *) &ei, 0, sizeof (ei));
1230
c50c785c 1231 /* Allocate struct to keep track of the symfile. */
5796c8dc
SS
1232 objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *)
1233 xmalloc (sizeof (struct dbx_symfile_info));
c50c785c
JM
1234 memset ((char *) objfile->deprecated_sym_stab_info,
1235 0, sizeof (struct dbx_symfile_info));
5796c8dc
SS
1236 make_cleanup (free_elfinfo, (void *) objfile);
1237
c50c785c
JM
1238 /* Process the normal ELF symbol table first. This may write some
1239 chain of info into the dbx_symfile_info in
1240 objfile->deprecated_sym_stab_info, which can later be used by
1241 elfstab_offset_sections. */
5796c8dc
SS
1242
1243 storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
1244 if (storage_needed < 0)
c50c785c
JM
1245 error (_("Can't read symbols from %s: %s"),
1246 bfd_get_filename (objfile->obfd),
5796c8dc
SS
1247 bfd_errmsg (bfd_get_error ()));
1248
1249 if (storage_needed > 0)
1250 {
1251 symbol_table = (asymbol **) xmalloc (storage_needed);
1252 make_cleanup (xfree, symbol_table);
1253 symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
1254
1255 if (symcount < 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
cf7f2e2d 1260 elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table, 0);
5796c8dc
SS
1261 }
1262
1263 /* Add the dynamic symbols. */
1264
1265 storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd);
1266
1267 if (storage_needed > 0)
1268 {
c50c785c
JM
1269 /* Memory gets permanently referenced from ABFD after
1270 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
1271 It happens only in the case when elf_slurp_reloc_table sees
1272 asection->relocation NULL. Determining which section is asection is
1273 done by _bfd_elf_get_synthetic_symtab which is all a bfd
1274 implementation detail, though. */
1275
1276 dyn_symbol_table = bfd_alloc (abfd, storage_needed);
5796c8dc
SS
1277 dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
1278 dyn_symbol_table);
1279
1280 if (dynsymcount < 0)
c50c785c
JM
1281 error (_("Can't read symbols from %s: %s"),
1282 bfd_get_filename (objfile->obfd),
5796c8dc
SS
1283 bfd_errmsg (bfd_get_error ()));
1284
cf7f2e2d 1285 elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table, 0);
c50c785c
JM
1286
1287 elf_rel_plt_read (objfile, dyn_symbol_table);
5796c8dc
SS
1288 }
1289
a45ae5f8
JM
1290 /* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
1291 elfutils (eu-strip) moves even the .symtab section into the .debug file.
1292
1293 bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
1294 'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
1295 address. But with eu-strip files bfd_get_synthetic_symtab would fail to
1296 read the code address from .opd while it reads the .symtab section from
1297 a separate debug info file as the .opd section is SHT_NOBITS there.
1298
1299 With SYNTH_ABFD the .opd section will be read from the original
1300 backlinked binary where it is valid. */
1301
1302 if (objfile->separate_debug_objfile_backlink)
1303 synth_abfd = objfile->separate_debug_objfile_backlink->obfd;
1304 else
1305 synth_abfd = abfd;
1306
5796c8dc
SS
1307 /* Add synthetic symbols - for instance, names for any PLT entries. */
1308
a45ae5f8 1309 synthcount = bfd_get_synthetic_symtab (synth_abfd, symcount, symbol_table,
5796c8dc
SS
1310 dynsymcount, dyn_symbol_table,
1311 &synthsyms);
1312 if (synthcount > 0)
1313 {
1314 asymbol **synth_symbol_table;
1315 long i;
1316
1317 make_cleanup (xfree, synthsyms);
1318 synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount);
1319 for (i = 0; i < synthcount; i++)
1320 synth_symbol_table[i] = synthsyms + i;
1321 make_cleanup (xfree, synth_symbol_table);
c50c785c
JM
1322 elf_symtab_read (objfile, ST_SYNTHETIC, synthcount,
1323 synth_symbol_table, 1);
5796c8dc
SS
1324 }
1325
1326 /* Install any minimal symbols that have been collected as the current
1327 minimal symbols for this objfile. The debug readers below this point
1328 should not generate new minimal symbols; if they do it's their
1329 responsibility to install them. "mdebug" appears to be the only one
1330 which will do this. */
1331
1332 install_minimal_symbols (objfile);
1333 do_cleanups (back_to);
1334
1335 /* Now process debugging information, which is contained in
c50c785c 1336 special ELF sections. */
5796c8dc 1337
c50c785c 1338 /* We first have to find them... */
5796c8dc
SS
1339 bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
1340
1341 /* ELF debugging information is inserted into the psymtab in the
1342 order of least informative first - most informative last. Since
1343 the psymtab table is searched `most recent insertion first' this
1344 increases the probability that more detailed debug information
1345 for a section is found.
1346
1347 For instance, an object file might contain both .mdebug (XCOFF)
1348 and .debug_info (DWARF2) sections then .mdebug is inserted first
1349 (searched last) and DWARF2 is inserted last (searched first). If
1350 we don't do this then the XCOFF info is found first - for code in
c50c785c 1351 an included file XCOFF info is useless. */
5796c8dc
SS
1352
1353 if (ei.mdebugsect)
1354 {
1355 const struct ecoff_debug_swap *swap;
1356
1357 /* .mdebug section, presumably holding ECOFF debugging
1358 information. */
1359 swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap;
1360 if (swap)
1361 elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect);
1362 }
1363 if (ei.stabsect)
1364 {
1365 asection *str_sect;
1366
1367 /* Stab sections have an associated string table that looks like
1368 a separate section. */
1369 str_sect = bfd_get_section_by_name (abfd, ".stabstr");
1370
1371 /* FIXME should probably warn about a stab section without a stabstr. */
1372 if (str_sect)
1373 elfstab_build_psymtabs (objfile,
5796c8dc
SS
1374 ei.stabsect,
1375 str_sect->filepos,
1376 bfd_section_size (abfd, str_sect));
1377 }
c50c785c 1378
a45ae5f8 1379 if (dwarf2_has_info (objfile, NULL))
5796c8dc 1380 {
c50c785c
JM
1381 /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
1382 information present in OBJFILE. If there is such debug info present
1383 never use .gdb_index. */
1384
1385 if (!objfile_has_partial_symbols (objfile)
1386 && dwarf2_initialize_objfile (objfile))
1387 objfile->sf = &elf_sym_fns_gdb_index;
1388 else
1389 {
1390 /* It is ok to do this even if the stabs reader made some
1391 partial symbols, because OBJF_PSYMTABS_READ has not been
1392 set, and so our lazy reader function will still be called
1393 when needed. */
1394 objfile->sf = &elf_sym_fns_lazy_psyms;
1395 }
5796c8dc 1396 }
c50c785c
JM
1397 /* If the file has its own symbol tables it has no separate debug
1398 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
1399 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
1400 `.note.gnu.build-id'. */
1401 else if (!objfile_has_partial_symbols (objfile))
cf7f2e2d
JM
1402 {
1403 char *debugfile;
1404
1405 debugfile = find_separate_debug_file_by_buildid (objfile);
1406
1407 if (debugfile == NULL)
1408 debugfile = find_separate_debug_file_by_debuglink (objfile);
1409
1410 if (debugfile)
1411 {
1412 bfd *abfd = symfile_bfd_open (debugfile);
1413
1414 symbol_file_add_separate (abfd, symfile_flags, objfile);
1415 xfree (debugfile);
1416 }
1417 }
5796c8dc
SS
1418}
1419
c50c785c
JM
1420/* Callback to lazily read psymtabs. */
1421
1422static void
1423read_psyms (struct objfile *objfile)
1424{
a45ae5f8 1425 if (dwarf2_has_info (objfile, NULL))
c50c785c
JM
1426 dwarf2_build_psymtabs (objfile);
1427}
1428
5796c8dc
SS
1429/* This cleans up the objfile's deprecated_sym_stab_info pointer, and
1430 the chain of stab_section_info's, that might be dangling from
1431 it. */
1432
1433static void
1434free_elfinfo (void *objp)
1435{
1436 struct objfile *objfile = (struct objfile *) objp;
1437 struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info;
1438 struct stab_section_info *ssi, *nssi;
1439
1440 ssi = dbxinfo->stab_section_info;
1441 while (ssi)
1442 {
1443 nssi = ssi->next;
1444 xfree (ssi);
1445 ssi = nssi;
1446 }
1447
1448 dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */
1449}
1450
1451
1452/* Initialize anything that needs initializing when a completely new symbol
1453 file is specified (not just adding some symbols from another file, e.g. a
1454 shared library).
1455
c50c785c
JM
1456 We reinitialize buildsym, since we may be reading stabs from an ELF
1457 file. */
5796c8dc
SS
1458
1459static void
1460elf_new_init (struct objfile *ignore)
1461{
1462 stabsread_new_init ();
1463 buildsym_new_init ();
1464}
1465
1466/* Perform any local cleanups required when we are done with a particular
1467 objfile. I.E, we are in the process of discarding all symbol information
1468 for an objfile, freeing up all memory held for it, and unlinking the
c50c785c 1469 objfile struct from the global list of known objfiles. */
5796c8dc
SS
1470
1471static void
1472elf_symfile_finish (struct objfile *objfile)
1473{
1474 if (objfile->deprecated_sym_stab_info != NULL)
1475 {
1476 xfree (objfile->deprecated_sym_stab_info);
1477 }
1478
1479 dwarf2_free_objfile (objfile);
1480}
1481
1482/* ELF specific initialization routine for reading symbols.
1483
1484 It is passed a pointer to a struct sym_fns which contains, among other
1485 things, the BFD for the file whose symbols are being read, and a slot for
1486 a pointer to "private data" which we can fill with goodies.
1487
1488 For now at least, we have nothing in particular to do, so this function is
c50c785c 1489 just a stub. */
5796c8dc
SS
1490
1491static void
1492elf_symfile_init (struct objfile *objfile)
1493{
1494 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1495 find this causes a significant slowdown in gdb then we could
1496 set it in the debug symbol readers only when necessary. */
1497 objfile->flags |= OBJF_REORDERED;
1498}
1499
1500/* When handling an ELF file that contains Sun STABS debug info,
1501 some of the debug info is relative to the particular chunk of the
1502 section that was generated in its individual .o file. E.g.
1503 offsets to static variables are relative to the start of the data
1504 segment *for that module before linking*. This information is
1505 painfully squirreled away in the ELF symbol table as local symbols
1506 with wierd names. Go get 'em when needed. */
1507
1508void
1509elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst)
1510{
c50c785c 1511 const char *filename = pst->filename;
5796c8dc
SS
1512 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
1513 struct stab_section_info *maybe = dbx->stab_section_info;
1514 struct stab_section_info *questionable = 0;
1515 int i;
5796c8dc
SS
1516
1517 /* The ELF symbol info doesn't include path names, so strip the path
1518 (if any) from the psymtab filename. */
c50c785c 1519 filename = lbasename (filename);
5796c8dc
SS
1520
1521 /* FIXME: This linear search could speed up significantly
1522 if it was chained in the right order to match how we search it,
c50c785c 1523 and if we unchained when we found a match. */
5796c8dc
SS
1524 for (; maybe; maybe = maybe->next)
1525 {
1526 if (filename[0] == maybe->filename[0]
c50c785c 1527 && filename_cmp (filename, maybe->filename) == 0)
5796c8dc
SS
1528 {
1529 /* We found a match. But there might be several source files
1530 (from different directories) with the same name. */
1531 if (0 == maybe->found)
1532 break;
1533 questionable = maybe; /* Might use it later. */
1534 }
1535 }
1536
1537 if (maybe == 0 && questionable != 0)
1538 {
1539 complaint (&symfile_complaints,
c50c785c
JM
1540 _("elf/stab section information questionable for %s"),
1541 filename);
5796c8dc
SS
1542 maybe = questionable;
1543 }
1544
1545 if (maybe)
1546 {
1547 /* Found it! Allocate a new psymtab struct, and fill it in. */
1548 maybe->found++;
1549 pst->section_offsets = (struct section_offsets *)
a45ae5f8 1550 obstack_alloc (&objfile->objfile_obstack,
5796c8dc
SS
1551 SIZEOF_N_SECTION_OFFSETS (objfile->num_sections));
1552 for (i = 0; i < maybe->num_sections; i++)
1553 (pst->section_offsets)->offsets[i] = maybe->sections[i];
1554 return;
1555 }
1556
1557 /* We were unable to find any offsets for this file. Complain. */
1558 if (dbx->stab_section_info) /* If there *is* any info, */
1559 complaint (&symfile_complaints,
1560 _("elf/stab section information missing for %s"), filename);
1561}
1562\f
1563/* Register that we are able to handle ELF object file formats. */
1564
c50c785c 1565static const struct sym_fns elf_sym_fns =
5796c8dc
SS
1566{
1567 bfd_target_elf_flavour,
c50c785c
JM
1568 elf_new_init, /* init anything gbl to entire symtab */
1569 elf_symfile_init, /* read initial info, setup for sym_read() */
1570 elf_symfile_read, /* read a symbol file into symtab */
1571 NULL, /* sym_read_psymbols */
1572 elf_symfile_finish, /* finished with file, cleanup */
1573 default_symfile_offsets, /* Translate ext. to int. relocation */
1574 elf_symfile_segments, /* Get segment information from a file. */
1575 NULL,
1576 default_symfile_relocate, /* Relocate a debug section. */
1577 &psym_functions
1578};
1579
1580/* The same as elf_sym_fns, but not registered and lazily reads
1581 psymbols. */
1582
1583static const struct sym_fns elf_sym_fns_lazy_psyms =
1584{
1585 bfd_target_elf_flavour,
1586 elf_new_init, /* init anything gbl to entire symtab */
1587 elf_symfile_init, /* read initial info, setup for sym_read() */
1588 elf_symfile_read, /* read a symbol file into symtab */
1589 read_psyms, /* sym_read_psymbols */
1590 elf_symfile_finish, /* finished with file, cleanup */
1591 default_symfile_offsets, /* Translate ext. to int. relocation */
1592 elf_symfile_segments, /* Get segment information from a file. */
1593 NULL,
1594 default_symfile_relocate, /* Relocate a debug section. */
1595 &psym_functions
1596};
1597
1598/* The same as elf_sym_fns, but not registered and uses the
1599 DWARF-specific GNU index rather than psymtab. */
1600static const struct sym_fns elf_sym_fns_gdb_index =
1601{
1602 bfd_target_elf_flavour,
1603 elf_new_init, /* init anything gbl to entire symab */
1604 elf_symfile_init, /* read initial info, setup for sym_red() */
1605 elf_symfile_read, /* read a symbol file into symtab */
1606 NULL, /* sym_read_psymbols */
1607 elf_symfile_finish, /* finished with file, cleanup */
1608 default_symfile_offsets, /* Translate ext. to int. relocatin */
1609 elf_symfile_segments, /* Get segment information from a file. */
1610 NULL,
1611 default_symfile_relocate, /* Relocate a debug section. */
1612 &dwarf2_gdb_index_functions
1613};
1614
1615/* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
1616
1617static const struct gnu_ifunc_fns elf_gnu_ifunc_fns =
1618{
1619 elf_gnu_ifunc_resolve_addr,
1620 elf_gnu_ifunc_resolve_name,
1621 elf_gnu_ifunc_resolver_stop,
1622 elf_gnu_ifunc_resolver_return_stop
5796c8dc
SS
1623};
1624
1625void
1626_initialize_elfread (void)
1627{
1628 add_symtab_fns (&elf_sym_fns);
c50c785c
JM
1629
1630 elf_objfile_gnu_ifunc_cache_data = register_objfile_data ();
1631 gnu_ifunc_fns_p = &elf_gnu_ifunc_fns;
5796c8dc 1632}