* elflink.c (_bfd_elf_merge_symbol): Rewrite weak symbol handling.
[binutils-gdb.git] / bfd / elflink.c
1 /* ELF linking support for BFD.
2 Copyright 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
3 Free Software Foundation, Inc.
4
5 This file is part of BFD, the Binary File Descriptor library.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20
21 #include "bfd.h"
22 #include "sysdep.h"
23 #include "bfdlink.h"
24 #include "libbfd.h"
25 #define ARCH_SIZE 0
26 #include "elf-bfd.h"
27
28 bfd_boolean
29 _bfd_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
30 {
31 flagword flags;
32 asection *s;
33 struct elf_link_hash_entry *h;
34 struct bfd_link_hash_entry *bh;
35 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
36 int ptralign;
37
38 /* This function may be called more than once. */
39 s = bfd_get_section_by_name (abfd, ".got");
40 if (s != NULL && (s->flags & SEC_LINKER_CREATED) != 0)
41 return TRUE;
42
43 switch (bed->s->arch_size)
44 {
45 case 32:
46 ptralign = 2;
47 break;
48
49 case 64:
50 ptralign = 3;
51 break;
52
53 default:
54 bfd_set_error (bfd_error_bad_value);
55 return FALSE;
56 }
57
58 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY
59 | SEC_LINKER_CREATED);
60
61 s = bfd_make_section (abfd, ".got");
62 if (s == NULL
63 || !bfd_set_section_flags (abfd, s, flags)
64 || !bfd_set_section_alignment (abfd, s, ptralign))
65 return FALSE;
66
67 if (bed->want_got_plt)
68 {
69 s = bfd_make_section (abfd, ".got.plt");
70 if (s == NULL
71 || !bfd_set_section_flags (abfd, s, flags)
72 || !bfd_set_section_alignment (abfd, s, ptralign))
73 return FALSE;
74 }
75
76 if (bed->want_got_sym)
77 {
78 /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
79 (or .got.plt) section. We don't do this in the linker script
80 because we don't want to define the symbol if we are not creating
81 a global offset table. */
82 bh = NULL;
83 if (!(_bfd_generic_link_add_one_symbol
84 (info, abfd, "_GLOBAL_OFFSET_TABLE_", BSF_GLOBAL, s,
85 bed->got_symbol_offset, NULL, FALSE, bed->collect, &bh)))
86 return FALSE;
87 h = (struct elf_link_hash_entry *) bh;
88 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
89 h->type = STT_OBJECT;
90
91 if (! info->executable
92 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
93 return FALSE;
94
95 elf_hash_table (info)->hgot = h;
96 }
97
98 /* The first bit of the global offset table is the header. */
99 s->_raw_size += bed->got_header_size + bed->got_symbol_offset;
100
101 return TRUE;
102 }
103 \f
104 /* Create some sections which will be filled in with dynamic linking
105 information. ABFD is an input file which requires dynamic sections
106 to be created. The dynamic sections take up virtual memory space
107 when the final executable is run, so we need to create them before
108 addresses are assigned to the output sections. We work out the
109 actual contents and size of these sections later. */
110
111 bfd_boolean
112 _bfd_elf_link_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
113 {
114 flagword flags;
115 register asection *s;
116 struct elf_link_hash_entry *h;
117 struct bfd_link_hash_entry *bh;
118 const struct elf_backend_data *bed;
119
120 if (! is_elf_hash_table (info->hash))
121 return FALSE;
122
123 if (elf_hash_table (info)->dynamic_sections_created)
124 return TRUE;
125
126 /* Make sure that all dynamic sections use the same input BFD. */
127 if (elf_hash_table (info)->dynobj == NULL)
128 elf_hash_table (info)->dynobj = abfd;
129 else
130 abfd = elf_hash_table (info)->dynobj;
131
132 /* Note that we set the SEC_IN_MEMORY flag for all of these
133 sections. */
134 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
135 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
136
137 /* A dynamically linked executable has a .interp section, but a
138 shared library does not. */
139 if (info->executable)
140 {
141 s = bfd_make_section (abfd, ".interp");
142 if (s == NULL
143 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
144 return FALSE;
145 }
146
147 if (! info->traditional_format)
148 {
149 s = bfd_make_section (abfd, ".eh_frame_hdr");
150 if (s == NULL
151 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
152 || ! bfd_set_section_alignment (abfd, s, 2))
153 return FALSE;
154 elf_hash_table (info)->eh_info.hdr_sec = s;
155 }
156
157 bed = get_elf_backend_data (abfd);
158
159 /* Create sections to hold version informations. These are removed
160 if they are not needed. */
161 s = bfd_make_section (abfd, ".gnu.version_d");
162 if (s == NULL
163 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
164 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
165 return FALSE;
166
167 s = bfd_make_section (abfd, ".gnu.version");
168 if (s == NULL
169 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
170 || ! bfd_set_section_alignment (abfd, s, 1))
171 return FALSE;
172
173 s = bfd_make_section (abfd, ".gnu.version_r");
174 if (s == NULL
175 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
176 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
177 return FALSE;
178
179 s = bfd_make_section (abfd, ".dynsym");
180 if (s == NULL
181 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
182 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
183 return FALSE;
184
185 s = bfd_make_section (abfd, ".dynstr");
186 if (s == NULL
187 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
188 return FALSE;
189
190 /* Create a strtab to hold the dynamic symbol names. */
191 if (elf_hash_table (info)->dynstr == NULL)
192 {
193 elf_hash_table (info)->dynstr = _bfd_elf_strtab_init ();
194 if (elf_hash_table (info)->dynstr == NULL)
195 return FALSE;
196 }
197
198 s = bfd_make_section (abfd, ".dynamic");
199 if (s == NULL
200 || ! bfd_set_section_flags (abfd, s, flags)
201 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
202 return FALSE;
203
204 /* The special symbol _DYNAMIC is always set to the start of the
205 .dynamic section. This call occurs before we have processed the
206 symbols for any dynamic object, so we don't have to worry about
207 overriding a dynamic definition. We could set _DYNAMIC in a
208 linker script, but we only want to define it if we are, in fact,
209 creating a .dynamic section. We don't want to define it if there
210 is no .dynamic section, since on some ELF platforms the start up
211 code examines it to decide how to initialize the process. */
212 bh = NULL;
213 if (! (_bfd_generic_link_add_one_symbol
214 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, 0, NULL, FALSE,
215 get_elf_backend_data (abfd)->collect, &bh)))
216 return FALSE;
217 h = (struct elf_link_hash_entry *) bh;
218 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
219 h->type = STT_OBJECT;
220
221 if (! info->executable
222 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
223 return FALSE;
224
225 s = bfd_make_section (abfd, ".hash");
226 if (s == NULL
227 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
228 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
229 return FALSE;
230 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
231
232 /* Let the backend create the rest of the sections. This lets the
233 backend set the right flags. The backend will normally create
234 the .got and .plt sections. */
235 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
236 return FALSE;
237
238 elf_hash_table (info)->dynamic_sections_created = TRUE;
239
240 return TRUE;
241 }
242
243 /* Create dynamic sections when linking against a dynamic object. */
244
245 bfd_boolean
246 _bfd_elf_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
247 {
248 flagword flags, pltflags;
249 asection *s;
250 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
251
252 /* We need to create .plt, .rel[a].plt, .got, .got.plt, .dynbss, and
253 .rel[a].bss sections. */
254
255 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY
256 | SEC_LINKER_CREATED);
257
258 pltflags = flags;
259 pltflags |= SEC_CODE;
260 if (bed->plt_not_loaded)
261 pltflags &= ~ (SEC_CODE | SEC_LOAD | SEC_HAS_CONTENTS);
262 if (bed->plt_readonly)
263 pltflags |= SEC_READONLY;
264
265 s = bfd_make_section (abfd, ".plt");
266 if (s == NULL
267 || ! bfd_set_section_flags (abfd, s, pltflags)
268 || ! bfd_set_section_alignment (abfd, s, bed->plt_alignment))
269 return FALSE;
270
271 if (bed->want_plt_sym)
272 {
273 /* Define the symbol _PROCEDURE_LINKAGE_TABLE_ at the start of the
274 .plt section. */
275 struct elf_link_hash_entry *h;
276 struct bfd_link_hash_entry *bh = NULL;
277
278 if (! (_bfd_generic_link_add_one_symbol
279 (info, abfd, "_PROCEDURE_LINKAGE_TABLE_", BSF_GLOBAL, s, 0, NULL,
280 FALSE, get_elf_backend_data (abfd)->collect, &bh)))
281 return FALSE;
282 h = (struct elf_link_hash_entry *) bh;
283 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
284 h->type = STT_OBJECT;
285
286 if (! info->executable
287 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
288 return FALSE;
289 }
290
291 s = bfd_make_section (abfd,
292 bed->default_use_rela_p ? ".rela.plt" : ".rel.plt");
293 if (s == NULL
294 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
295 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
296 return FALSE;
297
298 if (! _bfd_elf_create_got_section (abfd, info))
299 return FALSE;
300
301 if (bed->want_dynbss)
302 {
303 /* The .dynbss section is a place to put symbols which are defined
304 by dynamic objects, are referenced by regular objects, and are
305 not functions. We must allocate space for them in the process
306 image and use a R_*_COPY reloc to tell the dynamic linker to
307 initialize them at run time. The linker script puts the .dynbss
308 section into the .bss section of the final image. */
309 s = bfd_make_section (abfd, ".dynbss");
310 if (s == NULL
311 || ! bfd_set_section_flags (abfd, s, SEC_ALLOC | SEC_LINKER_CREATED))
312 return FALSE;
313
314 /* The .rel[a].bss section holds copy relocs. This section is not
315 normally needed. We need to create it here, though, so that the
316 linker will map it to an output section. We can't just create it
317 only if we need it, because we will not know whether we need it
318 until we have seen all the input files, and the first time the
319 main linker code calls BFD after examining all the input files
320 (size_dynamic_sections) the input sections have already been
321 mapped to the output sections. If the section turns out not to
322 be needed, we can discard it later. We will never need this
323 section when generating a shared object, since they do not use
324 copy relocs. */
325 if (! info->shared)
326 {
327 s = bfd_make_section (abfd,
328 (bed->default_use_rela_p
329 ? ".rela.bss" : ".rel.bss"));
330 if (s == NULL
331 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
332 || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
333 return FALSE;
334 }
335 }
336
337 return TRUE;
338 }
339 \f
340 /* Record a new dynamic symbol. We record the dynamic symbols as we
341 read the input files, since we need to have a list of all of them
342 before we can determine the final sizes of the output sections.
343 Note that we may actually call this function even though we are not
344 going to output any dynamic symbols; in some cases we know that a
345 symbol should be in the dynamic symbol table, but only if there is
346 one. */
347
348 bfd_boolean
349 _bfd_elf_link_record_dynamic_symbol (struct bfd_link_info *info,
350 struct elf_link_hash_entry *h)
351 {
352 if (h->dynindx == -1)
353 {
354 struct elf_strtab_hash *dynstr;
355 char *p;
356 const char *name;
357 bfd_size_type indx;
358
359 /* XXX: The ABI draft says the linker must turn hidden and
360 internal symbols into STB_LOCAL symbols when producing the
361 DSO. However, if ld.so honors st_other in the dynamic table,
362 this would not be necessary. */
363 switch (ELF_ST_VISIBILITY (h->other))
364 {
365 case STV_INTERNAL:
366 case STV_HIDDEN:
367 if (h->root.type != bfd_link_hash_undefined
368 && h->root.type != bfd_link_hash_undefweak)
369 {
370 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
371 return TRUE;
372 }
373
374 default:
375 break;
376 }
377
378 h->dynindx = elf_hash_table (info)->dynsymcount;
379 ++elf_hash_table (info)->dynsymcount;
380
381 dynstr = elf_hash_table (info)->dynstr;
382 if (dynstr == NULL)
383 {
384 /* Create a strtab to hold the dynamic symbol names. */
385 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
386 if (dynstr == NULL)
387 return FALSE;
388 }
389
390 /* We don't put any version information in the dynamic string
391 table. */
392 name = h->root.root.string;
393 p = strchr (name, ELF_VER_CHR);
394 if (p != NULL)
395 /* We know that the p points into writable memory. In fact,
396 there are only a few symbols that have read-only names, being
397 those like _GLOBAL_OFFSET_TABLE_ that are created specially
398 by the backends. Most symbols will have names pointing into
399 an ELF string table read from a file, or to objalloc memory. */
400 *p = 0;
401
402 indx = _bfd_elf_strtab_add (dynstr, name, p != NULL);
403
404 if (p != NULL)
405 *p = ELF_VER_CHR;
406
407 if (indx == (bfd_size_type) -1)
408 return FALSE;
409 h->dynstr_index = indx;
410 }
411
412 return TRUE;
413 }
414 \f
415 /* Record an assignment to a symbol made by a linker script. We need
416 this in case some dynamic object refers to this symbol. */
417
418 bfd_boolean
419 bfd_elf_record_link_assignment (bfd *output_bfd ATTRIBUTE_UNUSED,
420 struct bfd_link_info *info,
421 const char *name,
422 bfd_boolean provide)
423 {
424 struct elf_link_hash_entry *h;
425
426 if (!is_elf_hash_table (info->hash))
427 return TRUE;
428
429 h = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, TRUE, FALSE);
430 if (h == NULL)
431 return FALSE;
432
433 /* Since we're defining the symbol, don't let it seem to have not
434 been defined. record_dynamic_symbol and size_dynamic_sections
435 may depend on this. */
436 if (h->root.type == bfd_link_hash_undefweak
437 || h->root.type == bfd_link_hash_undefined)
438 h->root.type = bfd_link_hash_new;
439
440 if (h->root.type == bfd_link_hash_new)
441 h->elf_link_hash_flags &= ~ELF_LINK_NON_ELF;
442
443 /* If this symbol is being provided by the linker script, and it is
444 currently defined by a dynamic object, but not by a regular
445 object, then mark it as undefined so that the generic linker will
446 force the correct value. */
447 if (provide
448 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
449 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
450 h->root.type = bfd_link_hash_undefined;
451
452 /* If this symbol is not being provided by the linker script, and it is
453 currently defined by a dynamic object, but not by a regular object,
454 then clear out any version information because the symbol will not be
455 associated with the dynamic object any more. */
456 if (!provide
457 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
458 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
459 h->verinfo.verdef = NULL;
460
461 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
462
463 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
464 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
465 || info->shared)
466 && h->dynindx == -1)
467 {
468 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
469 return FALSE;
470
471 /* If this is a weak defined symbol, and we know a corresponding
472 real symbol from the same dynamic object, make sure the real
473 symbol is also made into a dynamic symbol. */
474 if (h->weakdef != NULL
475 && h->weakdef->dynindx == -1)
476 {
477 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
478 return FALSE;
479 }
480 }
481
482 return TRUE;
483 }
484
485 /* Record a new local dynamic symbol. Returns 0 on failure, 1 on
486 success, and 2 on a failure caused by attempting to record a symbol
487 in a discarded section, eg. a discarded link-once section symbol. */
488
489 int
490 elf_link_record_local_dynamic_symbol (struct bfd_link_info *info,
491 bfd *input_bfd,
492 long input_indx)
493 {
494 bfd_size_type amt;
495 struct elf_link_local_dynamic_entry *entry;
496 struct elf_link_hash_table *eht;
497 struct elf_strtab_hash *dynstr;
498 unsigned long dynstr_index;
499 char *name;
500 Elf_External_Sym_Shndx eshndx;
501 char esym[sizeof (Elf64_External_Sym)];
502
503 if (! is_elf_hash_table (info->hash))
504 return 0;
505
506 /* See if the entry exists already. */
507 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
508 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
509 return 1;
510
511 amt = sizeof (*entry);
512 entry = bfd_alloc (input_bfd, amt);
513 if (entry == NULL)
514 return 0;
515
516 /* Go find the symbol, so that we can find it's name. */
517 if (!bfd_elf_get_elf_syms (input_bfd, &elf_tdata (input_bfd)->symtab_hdr,
518 1, input_indx, &entry->isym, esym, &eshndx))
519 {
520 bfd_release (input_bfd, entry);
521 return 0;
522 }
523
524 if (entry->isym.st_shndx != SHN_UNDEF
525 && (entry->isym.st_shndx < SHN_LORESERVE
526 || entry->isym.st_shndx > SHN_HIRESERVE))
527 {
528 asection *s;
529
530 s = bfd_section_from_elf_index (input_bfd, entry->isym.st_shndx);
531 if (s == NULL || bfd_is_abs_section (s->output_section))
532 {
533 /* We can still bfd_release here as nothing has done another
534 bfd_alloc. We can't do this later in this function. */
535 bfd_release (input_bfd, entry);
536 return 2;
537 }
538 }
539
540 name = (bfd_elf_string_from_elf_section
541 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
542 entry->isym.st_name));
543
544 dynstr = elf_hash_table (info)->dynstr;
545 if (dynstr == NULL)
546 {
547 /* Create a strtab to hold the dynamic symbol names. */
548 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
549 if (dynstr == NULL)
550 return 0;
551 }
552
553 dynstr_index = _bfd_elf_strtab_add (dynstr, name, FALSE);
554 if (dynstr_index == (unsigned long) -1)
555 return 0;
556 entry->isym.st_name = dynstr_index;
557
558 eht = elf_hash_table (info);
559
560 entry->next = eht->dynlocal;
561 eht->dynlocal = entry;
562 entry->input_bfd = input_bfd;
563 entry->input_indx = input_indx;
564 eht->dynsymcount++;
565
566 /* Whatever binding the symbol had before, it's now local. */
567 entry->isym.st_info
568 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
569
570 /* The dynindx will be set at the end of size_dynamic_sections. */
571
572 return 1;
573 }
574
575 /* Return the dynindex of a local dynamic symbol. */
576
577 long
578 _bfd_elf_link_lookup_local_dynindx (struct bfd_link_info *info,
579 bfd *input_bfd,
580 long input_indx)
581 {
582 struct elf_link_local_dynamic_entry *e;
583
584 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
585 if (e->input_bfd == input_bfd && e->input_indx == input_indx)
586 return e->dynindx;
587 return -1;
588 }
589
590 /* This function is used to renumber the dynamic symbols, if some of
591 them are removed because they are marked as local. This is called
592 via elf_link_hash_traverse. */
593
594 static bfd_boolean
595 elf_link_renumber_hash_table_dynsyms (struct elf_link_hash_entry *h,
596 void *data)
597 {
598 size_t *count = data;
599
600 if (h->root.type == bfd_link_hash_warning)
601 h = (struct elf_link_hash_entry *) h->root.u.i.link;
602
603 if (h->dynindx != -1)
604 h->dynindx = ++(*count);
605
606 return TRUE;
607 }
608
609 /* Assign dynsym indices. In a shared library we generate a section
610 symbol for each output section, which come first. Next come all of
611 the back-end allocated local dynamic syms, followed by the rest of
612 the global symbols. */
613
614 unsigned long
615 _bfd_elf_link_renumber_dynsyms (bfd *output_bfd, struct bfd_link_info *info)
616 {
617 unsigned long dynsymcount = 0;
618
619 if (info->shared)
620 {
621 asection *p;
622 for (p = output_bfd->sections; p ; p = p->next)
623 if ((p->flags & SEC_EXCLUDE) == 0)
624 elf_section_data (p)->dynindx = ++dynsymcount;
625 }
626
627 if (elf_hash_table (info)->dynlocal)
628 {
629 struct elf_link_local_dynamic_entry *p;
630 for (p = elf_hash_table (info)->dynlocal; p ; p = p->next)
631 p->dynindx = ++dynsymcount;
632 }
633
634 elf_link_hash_traverse (elf_hash_table (info),
635 elf_link_renumber_hash_table_dynsyms,
636 &dynsymcount);
637
638 /* There is an unused NULL entry at the head of the table which
639 we must account for in our count. Unless there weren't any
640 symbols, which means we'll have no table at all. */
641 if (dynsymcount != 0)
642 ++dynsymcount;
643
644 return elf_hash_table (info)->dynsymcount = dynsymcount;
645 }
646
647 /* This function is called when we want to define a new symbol. It
648 handles the various cases which arise when we find a definition in
649 a dynamic object, or when there is already a definition in a
650 dynamic object. The new symbol is described by NAME, SYM, PSEC,
651 and PVALUE. We set SYM_HASH to the hash table entry. We set
652 OVERRIDE if the old symbol is overriding a new definition. We set
653 TYPE_CHANGE_OK if it is OK for the type to change. We set
654 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
655 change, we mean that we shouldn't warn if the type or size does
656 change. DT_NEEDED indicates if it comes from a DT_NEEDED entry of
657 a shared object. */
658
659 bfd_boolean
660 _bfd_elf_merge_symbol (bfd *abfd,
661 struct bfd_link_info *info,
662 const char *name,
663 Elf_Internal_Sym *sym,
664 asection **psec,
665 bfd_vma *pvalue,
666 struct elf_link_hash_entry **sym_hash,
667 bfd_boolean *skip,
668 bfd_boolean *override,
669 bfd_boolean *type_change_ok,
670 bfd_boolean *size_change_ok,
671 bfd_boolean dt_needed)
672 {
673 asection *sec;
674 struct elf_link_hash_entry *h;
675 struct elf_link_hash_entry *flip;
676 int bind;
677 bfd *oldbfd;
678 bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
679 bfd_boolean newweak, oldweak;
680
681 *skip = FALSE;
682 *override = FALSE;
683
684 sec = *psec;
685 bind = ELF_ST_BIND (sym->st_info);
686
687 if (! bfd_is_und_section (sec))
688 h = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, FALSE, FALSE);
689 else
690 h = ((struct elf_link_hash_entry *)
691 bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, FALSE, FALSE));
692 if (h == NULL)
693 return FALSE;
694 *sym_hash = h;
695
696 /* This code is for coping with dynamic objects, and is only useful
697 if we are doing an ELF link. */
698 if (info->hash->creator != abfd->xvec)
699 return TRUE;
700
701 /* For merging, we only care about real symbols. */
702
703 while (h->root.type == bfd_link_hash_indirect
704 || h->root.type == bfd_link_hash_warning)
705 h = (struct elf_link_hash_entry *) h->root.u.i.link;
706
707 /* If we just created the symbol, mark it as being an ELF symbol.
708 Other than that, there is nothing to do--there is no merge issue
709 with a newly defined symbol--so we just return. */
710
711 if (h->root.type == bfd_link_hash_new)
712 {
713 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
714 return TRUE;
715 }
716
717 /* OLDBFD is a BFD associated with the existing symbol. */
718
719 switch (h->root.type)
720 {
721 default:
722 oldbfd = NULL;
723 break;
724
725 case bfd_link_hash_undefined:
726 case bfd_link_hash_undefweak:
727 oldbfd = h->root.u.undef.abfd;
728 break;
729
730 case bfd_link_hash_defined:
731 case bfd_link_hash_defweak:
732 oldbfd = h->root.u.def.section->owner;
733 break;
734
735 case bfd_link_hash_common:
736 oldbfd = h->root.u.c.p->section->owner;
737 break;
738 }
739
740 /* In cases involving weak versioned symbols, we may wind up trying
741 to merge a symbol with itself. Catch that here, to avoid the
742 confusion that results if we try to override a symbol with
743 itself. The additional tests catch cases like
744 _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
745 dynamic object, which we do want to handle here. */
746 if (abfd == oldbfd
747 && ((abfd->flags & DYNAMIC) == 0
748 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))
749 return TRUE;
750
751 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
752 respectively, is from a dynamic object. */
753
754 if ((abfd->flags & DYNAMIC) != 0)
755 newdyn = TRUE;
756 else
757 newdyn = FALSE;
758
759 if (oldbfd != NULL)
760 olddyn = (oldbfd->flags & DYNAMIC) != 0;
761 else
762 {
763 asection *hsec;
764
765 /* This code handles the special SHN_MIPS_{TEXT,DATA} section
766 indices used by MIPS ELF. */
767 switch (h->root.type)
768 {
769 default:
770 hsec = NULL;
771 break;
772
773 case bfd_link_hash_defined:
774 case bfd_link_hash_defweak:
775 hsec = h->root.u.def.section;
776 break;
777
778 case bfd_link_hash_common:
779 hsec = h->root.u.c.p->section;
780 break;
781 }
782
783 if (hsec == NULL)
784 olddyn = FALSE;
785 else
786 olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0;
787 }
788
789 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
790 respectively, appear to be a definition rather than reference. */
791
792 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
793 newdef = FALSE;
794 else
795 newdef = TRUE;
796
797 if (h->root.type == bfd_link_hash_undefined
798 || h->root.type == bfd_link_hash_undefweak
799 || h->root.type == bfd_link_hash_common)
800 olddef = FALSE;
801 else
802 olddef = TRUE;
803
804 /* We need to remember if a symbol has a definition in a dynamic
805 object or is weak in all dynamic objects. Internal and hidden
806 visibility will make it unavailable to dynamic objects. */
807 if (newdyn && (h->elf_link_hash_flags & ELF_LINK_DYNAMIC_DEF) == 0)
808 {
809 if (!bfd_is_und_section (sec))
810 h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_DEF;
811 else
812 {
813 /* Check if this symbol is weak in all dynamic objects. If it
814 is the first time we see it in a dynamic object, we mark
815 if it is weak. Otherwise, we clear it. */
816 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
817 {
818 if (bind == STB_WEAK)
819 h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_WEAK;
820 }
821 else if (bind != STB_WEAK)
822 h->elf_link_hash_flags &= ~ELF_LINK_DYNAMIC_WEAK;
823 }
824 }
825
826 /* If the old symbol has non-default visibility, we ignore the new
827 definition from a dynamic object. */
828 if (newdyn
829 && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
830 && !bfd_is_und_section (sec))
831 {
832 *skip = TRUE;
833 /* Make sure this symbol is dynamic. */
834 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
835 /* A protected symbol has external availability. Make sure it is
836 recorded as dynamic.
837
838 FIXME: Should we check type and size for protected symbol? */
839 if (ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
840 return _bfd_elf_link_record_dynamic_symbol (info, h);
841 else
842 return TRUE;
843 }
844 else if (!newdyn
845 && ELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT
846 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
847 {
848 /* If the new symbol with non-default visibility comes from a
849 relocatable file and the old definition comes from a dynamic
850 object, we remove the old definition. */
851 if ((*sym_hash)->root.type == bfd_link_hash_indirect)
852 h = *sym_hash;
853
854 if ((h->root.und_next || info->hash->undefs_tail == &h->root)
855 && bfd_is_und_section (sec))
856 {
857 /* If the new symbol is undefined and the old symbol was
858 also undefined before, we need to make sure
859 _bfd_generic_link_add_one_symbol doesn't mess
860 up the linker hash table undefs list. Since the old
861 definition came from a dynamic object, it is still on the
862 undefs list. */
863 h->root.type = bfd_link_hash_undefined;
864 /* FIXME: What if the new symbol is weak undefined? */
865 h->root.u.undef.abfd = abfd;
866 }
867 else
868 {
869 h->root.type = bfd_link_hash_new;
870 h->root.u.undef.abfd = NULL;
871 }
872
873 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
874 {
875 h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC;
876 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_DYNAMIC
877 | ELF_LINK_DYNAMIC_DEF);
878 }
879 /* FIXME: Should we check type and size for protected symbol? */
880 h->size = 0;
881 h->type = 0;
882 return TRUE;
883 }
884
885 /* Differentiate strong and weak symbols. */
886 newweak = bind == STB_WEAK;
887 oldweak = (h->root.type == bfd_link_hash_defweak
888 || h->root.type == bfd_link_hash_undefweak);
889
890 /* It's OK to change the type if either the existing symbol or the
891 new symbol is weak. A type change is also OK if the old symbol
892 is undefined and the new symbol is defined. */
893
894 if (oldweak
895 || newweak
896 || (newdef
897 && h->root.type == bfd_link_hash_undefined))
898 *type_change_ok = TRUE;
899
900 /* It's OK to change the size if either the existing symbol or the
901 new symbol is weak, or if the old symbol is undefined. */
902
903 if (*type_change_ok
904 || h->root.type == bfd_link_hash_undefined)
905 *size_change_ok = TRUE;
906
907 /* If a new weak symbol comes from a regular file and the old symbol
908 comes from a dynamic library, we treat the new one as strong.
909 Similarly, an old weak symbol from a regular file is treated as
910 strong when the new symbol comes from a dynamic library. Further,
911 an old weak symbol from a dynamic library is treated as strong if
912 the new symbol is from a DT_NEEDED dynamic library. */
913 if (!newdyn && olddyn)
914 newweak = FALSE;
915 if ((!olddyn || dt_needed) && newdyn)
916 oldweak = FALSE;
917
918 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
919 symbol, respectively, appears to be a common symbol in a dynamic
920 object. If a symbol appears in an uninitialized section, and is
921 not weak, and is not a function, then it may be a common symbol
922 which was resolved when the dynamic object was created. We want
923 to treat such symbols specially, because they raise special
924 considerations when setting the symbol size: if the symbol
925 appears as a common symbol in a regular object, and the size in
926 the regular object is larger, we must make sure that we use the
927 larger size. This problematic case can always be avoided in C,
928 but it must be handled correctly when using Fortran shared
929 libraries.
930
931 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
932 likewise for OLDDYNCOMMON and OLDDEF.
933
934 Note that this test is just a heuristic, and that it is quite
935 possible to have an uninitialized symbol in a shared object which
936 is really a definition, rather than a common symbol. This could
937 lead to some minor confusion when the symbol really is a common
938 symbol in some regular object. However, I think it will be
939 harmless. */
940
941 if (newdyn
942 && newdef
943 && !newweak
944 && (sec->flags & SEC_ALLOC) != 0
945 && (sec->flags & SEC_LOAD) == 0
946 && sym->st_size > 0
947 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
948 newdyncommon = TRUE;
949 else
950 newdyncommon = FALSE;
951
952 if (olddyn
953 && olddef
954 && h->root.type == bfd_link_hash_defined
955 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
956 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
957 && (h->root.u.def.section->flags & SEC_LOAD) == 0
958 && h->size > 0
959 && h->type != STT_FUNC)
960 olddyncommon = TRUE;
961 else
962 olddyncommon = FALSE;
963
964 /* If both the old and the new symbols look like common symbols in a
965 dynamic object, set the size of the symbol to the larger of the
966 two. */
967
968 if (olddyncommon
969 && newdyncommon
970 && sym->st_size != h->size)
971 {
972 /* Since we think we have two common symbols, issue a multiple
973 common warning if desired. Note that we only warn if the
974 size is different. If the size is the same, we simply let
975 the old symbol override the new one as normally happens with
976 symbols defined in dynamic objects. */
977
978 if (! ((*info->callbacks->multiple_common)
979 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
980 h->size, abfd, bfd_link_hash_common, sym->st_size)))
981 return FALSE;
982
983 if (sym->st_size > h->size)
984 h->size = sym->st_size;
985
986 *size_change_ok = TRUE;
987 }
988
989 /* If we are looking at a dynamic object, and we have found a
990 definition, we need to see if the symbol was already defined by
991 some other object. If so, we want to use the existing
992 definition, and we do not want to report a multiple symbol
993 definition error; we do this by clobbering *PSEC to be
994 bfd_und_section_ptr.
995
996 We treat a common symbol as a definition if the symbol in the
997 shared library is a function, since common symbols always
998 represent variables; this can cause confusion in principle, but
999 any such confusion would seem to indicate an erroneous program or
1000 shared library. We also permit a common symbol in a regular
1001 object to override a weak symbol in a shared object. */
1002
1003 if (newdyn
1004 && newdef
1005 && (olddef
1006 || (h->root.type == bfd_link_hash_common
1007 && (newweak
1008 || ELF_ST_TYPE (sym->st_info) == STT_FUNC)))
1009 && (!oldweak || newweak))
1010 {
1011 *override = TRUE;
1012 newdef = FALSE;
1013 newdyncommon = FALSE;
1014
1015 *psec = sec = bfd_und_section_ptr;
1016 *size_change_ok = TRUE;
1017
1018 /* If we get here when the old symbol is a common symbol, then
1019 we are explicitly letting it override a weak symbol or
1020 function in a dynamic object, and we don't want to warn about
1021 a type change. If the old symbol is a defined symbol, a type
1022 change warning may still be appropriate. */
1023
1024 if (h->root.type == bfd_link_hash_common)
1025 *type_change_ok = TRUE;
1026 }
1027
1028 /* Handle the special case of an old common symbol merging with a
1029 new symbol which looks like a common symbol in a shared object.
1030 We change *PSEC and *PVALUE to make the new symbol look like a
1031 common symbol, and let _bfd_generic_link_add_one_symbol will do
1032 the right thing. */
1033
1034 if (newdyncommon
1035 && h->root.type == bfd_link_hash_common)
1036 {
1037 *override = TRUE;
1038 newdef = FALSE;
1039 newdyncommon = FALSE;
1040 *pvalue = sym->st_size;
1041 *psec = sec = bfd_com_section_ptr;
1042 *size_change_ok = TRUE;
1043 }
1044
1045 /* If the old symbol is from a dynamic object, and the new symbol is
1046 a definition which is not from a dynamic object, then the new
1047 symbol overrides the old symbol. Symbols from regular files
1048 always take precedence over symbols from dynamic objects, even if
1049 they are defined after the dynamic object in the link.
1050
1051 As above, we again permit a common symbol in a regular object to
1052 override a definition in a shared object if the shared object
1053 symbol is a function or is weak.
1054
1055 As above, we permit a non-weak definition in a shared object to
1056 override a weak definition in a regular object. */
1057
1058 flip = NULL;
1059 if (! newdyn
1060 && (newdef
1061 || (bfd_is_com_section (sec)
1062 && (oldweak
1063 || h->type == STT_FUNC)))
1064 && olddyn
1065 && olddef
1066 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
1067 && (!newweak || oldweak))
1068 {
1069 /* Change the hash table entry to undefined, and let
1070 _bfd_generic_link_add_one_symbol do the right thing with the
1071 new definition. */
1072
1073 h->root.type = bfd_link_hash_undefined;
1074 h->root.u.undef.abfd = h->root.u.def.section->owner;
1075 *size_change_ok = TRUE;
1076
1077 olddef = FALSE;
1078 olddyncommon = FALSE;
1079
1080 /* We again permit a type change when a common symbol may be
1081 overriding a function. */
1082
1083 if (bfd_is_com_section (sec))
1084 *type_change_ok = TRUE;
1085
1086 if ((*sym_hash)->root.type == bfd_link_hash_indirect)
1087 flip = *sym_hash;
1088 else
1089 /* This union may have been set to be non-NULL when this symbol
1090 was seen in a dynamic object. We must force the union to be
1091 NULL, so that it is correct for a regular symbol. */
1092 h->verinfo.vertree = NULL;
1093 }
1094
1095 /* Handle the special case of a new common symbol merging with an
1096 old symbol that looks like it might be a common symbol defined in
1097 a shared object. Note that we have already handled the case in
1098 which a new common symbol should simply override the definition
1099 in the shared library. */
1100
1101 if (! newdyn
1102 && bfd_is_com_section (sec)
1103 && olddyncommon)
1104 {
1105 /* It would be best if we could set the hash table entry to a
1106 common symbol, but we don't know what to use for the section
1107 or the alignment. */
1108 if (! ((*info->callbacks->multiple_common)
1109 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
1110 h->size, abfd, bfd_link_hash_common, sym->st_size)))
1111 return FALSE;
1112
1113 /* If the presumed common symbol in the dynamic object is
1114 larger, pretend that the new symbol has its size. */
1115
1116 if (h->size > *pvalue)
1117 *pvalue = h->size;
1118
1119 /* FIXME: We no longer know the alignment required by the symbol
1120 in the dynamic object, so we just wind up using the one from
1121 the regular object. */
1122
1123 olddef = FALSE;
1124 olddyncommon = FALSE;
1125
1126 h->root.type = bfd_link_hash_undefined;
1127 h->root.u.undef.abfd = h->root.u.def.section->owner;
1128
1129 *size_change_ok = TRUE;
1130 *type_change_ok = TRUE;
1131
1132 if ((*sym_hash)->root.type == bfd_link_hash_indirect)
1133 flip = *sym_hash;
1134 else
1135 h->verinfo.vertree = NULL;
1136 }
1137
1138 if (flip != NULL)
1139 {
1140 /* Handle the case where we had a versioned symbol in a dynamic
1141 library and now find a definition in a normal object. In this
1142 case, we make the versioned symbol point to the normal one. */
1143 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
1144 flip->root.type = h->root.type;
1145 h->root.type = bfd_link_hash_indirect;
1146 h->root.u.i.link = (struct bfd_link_hash_entry *) flip;
1147 (*bed->elf_backend_copy_indirect_symbol) (bed, flip, h);
1148 flip->root.u.undef.abfd = h->root.u.undef.abfd;
1149 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1150 {
1151 h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC;
1152 flip->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1153 }
1154 }
1155
1156 return TRUE;
1157 }
1158
1159 /* This function is called to create an indirect symbol from the
1160 default for the symbol with the default version if needed. The
1161 symbol is described by H, NAME, SYM, PSEC, VALUE, and OVERRIDE. We
1162 set DYNSYM if the new indirect symbol is dynamic. DT_NEEDED
1163 indicates if it comes from a DT_NEEDED entry of a shared object. */
1164
1165 bfd_boolean
1166 _bfd_elf_add_default_symbol (bfd *abfd,
1167 struct bfd_link_info *info,
1168 struct elf_link_hash_entry *h,
1169 const char *name,
1170 Elf_Internal_Sym *sym,
1171 asection **psec,
1172 bfd_vma *value,
1173 bfd_boolean *dynsym,
1174 bfd_boolean override,
1175 bfd_boolean dt_needed)
1176 {
1177 bfd_boolean type_change_ok;
1178 bfd_boolean size_change_ok;
1179 bfd_boolean skip;
1180 char *shortname;
1181 struct elf_link_hash_entry *hi;
1182 struct bfd_link_hash_entry *bh;
1183 const struct elf_backend_data *bed;
1184 bfd_boolean collect;
1185 bfd_boolean dynamic;
1186 char *p;
1187 size_t len, shortlen;
1188 asection *sec;
1189
1190 /* If this symbol has a version, and it is the default version, we
1191 create an indirect symbol from the default name to the fully
1192 decorated name. This will cause external references which do not
1193 specify a version to be bound to this version of the symbol. */
1194 p = strchr (name, ELF_VER_CHR);
1195 if (p == NULL || p[1] != ELF_VER_CHR)
1196 return TRUE;
1197
1198 if (override)
1199 {
1200 /* We are overridden by an old definition. We need to check if we
1201 need to create the indirect symbol from the default name. */
1202 hi = elf_link_hash_lookup (elf_hash_table (info), name, TRUE,
1203 FALSE, FALSE);
1204 BFD_ASSERT (hi != NULL);
1205 if (hi == h)
1206 return TRUE;
1207 while (hi->root.type == bfd_link_hash_indirect
1208 || hi->root.type == bfd_link_hash_warning)
1209 {
1210 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1211 if (hi == h)
1212 return TRUE;
1213 }
1214 }
1215
1216 bed = get_elf_backend_data (abfd);
1217 collect = bed->collect;
1218 dynamic = (abfd->flags & DYNAMIC) != 0;
1219
1220 shortlen = p - name;
1221 shortname = bfd_hash_allocate (&info->hash->table, shortlen + 1);
1222 if (shortname == NULL)
1223 return FALSE;
1224 memcpy (shortname, name, shortlen);
1225 shortname[shortlen] = '\0';
1226
1227 /* We are going to create a new symbol. Merge it with any existing
1228 symbol with this name. For the purposes of the merge, act as
1229 though we were defining the symbol we just defined, although we
1230 actually going to define an indirect symbol. */
1231 type_change_ok = FALSE;
1232 size_change_ok = FALSE;
1233 sec = *psec;
1234 if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
1235 &hi, &skip, &override, &type_change_ok,
1236 &size_change_ok, dt_needed))
1237 return FALSE;
1238
1239 if (skip)
1240 goto nondefault;
1241
1242 if (! override)
1243 {
1244 bh = &hi->root;
1245 if (! (_bfd_generic_link_add_one_symbol
1246 (info, abfd, shortname, BSF_INDIRECT, bfd_ind_section_ptr,
1247 0, name, FALSE, collect, &bh)))
1248 return FALSE;
1249 hi = (struct elf_link_hash_entry *) bh;
1250 }
1251 else
1252 {
1253 /* In this case the symbol named SHORTNAME is overriding the
1254 indirect symbol we want to add. We were planning on making
1255 SHORTNAME an indirect symbol referring to NAME. SHORTNAME
1256 is the name without a version. NAME is the fully versioned
1257 name, and it is the default version.
1258
1259 Overriding means that we already saw a definition for the
1260 symbol SHORTNAME in a regular object, and it is overriding
1261 the symbol defined in the dynamic object.
1262
1263 When this happens, we actually want to change NAME, the
1264 symbol we just added, to refer to SHORTNAME. This will cause
1265 references to NAME in the shared object to become references
1266 to SHORTNAME in the regular object. This is what we expect
1267 when we override a function in a shared object: that the
1268 references in the shared object will be mapped to the
1269 definition in the regular object. */
1270
1271 while (hi->root.type == bfd_link_hash_indirect
1272 || hi->root.type == bfd_link_hash_warning)
1273 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1274
1275 h->root.type = bfd_link_hash_indirect;
1276 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1277 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1278 {
1279 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1280 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1281 if (hi->elf_link_hash_flags
1282 & (ELF_LINK_HASH_REF_REGULAR
1283 | ELF_LINK_HASH_DEF_REGULAR))
1284 {
1285 if (! _bfd_elf_link_record_dynamic_symbol (info, hi))
1286 return FALSE;
1287 }
1288 }
1289
1290 /* Now set HI to H, so that the following code will set the
1291 other fields correctly. */
1292 hi = h;
1293 }
1294
1295 /* If there is a duplicate definition somewhere, then HI may not
1296 point to an indirect symbol. We will have reported an error to
1297 the user in that case. */
1298
1299 if (hi->root.type == bfd_link_hash_indirect)
1300 {
1301 struct elf_link_hash_entry *ht;
1302
1303 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1304 (*bed->elf_backend_copy_indirect_symbol) (bed, ht, hi);
1305
1306 /* See if the new flags lead us to realize that the symbol must
1307 be dynamic. */
1308 if (! *dynsym)
1309 {
1310 if (! dynamic)
1311 {
1312 if (info->shared
1313 || ((hi->elf_link_hash_flags
1314 & ELF_LINK_HASH_REF_DYNAMIC) != 0))
1315 *dynsym = TRUE;
1316 }
1317 else
1318 {
1319 if ((hi->elf_link_hash_flags
1320 & ELF_LINK_HASH_REF_REGULAR) != 0)
1321 *dynsym = TRUE;
1322 }
1323 }
1324 }
1325
1326 /* We also need to define an indirection from the nondefault version
1327 of the symbol. */
1328
1329 nondefault:
1330 len = strlen (name);
1331 shortname = bfd_hash_allocate (&info->hash->table, len);
1332 if (shortname == NULL)
1333 return FALSE;
1334 memcpy (shortname, name, shortlen);
1335 memcpy (shortname + shortlen, p + 1, len - shortlen);
1336
1337 /* Once again, merge with any existing symbol. */
1338 type_change_ok = FALSE;
1339 size_change_ok = FALSE;
1340 sec = *psec;
1341 if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
1342 &hi, &skip, &override, &type_change_ok,
1343 &size_change_ok, dt_needed))
1344 return FALSE;
1345
1346 if (skip)
1347 return TRUE;
1348
1349 if (override)
1350 {
1351 /* Here SHORTNAME is a versioned name, so we don't expect to see
1352 the type of override we do in the case above unless it is
1353 overridden by a versioned definition. */
1354 if (hi->root.type != bfd_link_hash_defined
1355 && hi->root.type != bfd_link_hash_defweak)
1356 (*_bfd_error_handler)
1357 (_("%s: warning: unexpected redefinition of indirect versioned symbol `%s'"),
1358 bfd_archive_filename (abfd), shortname);
1359 }
1360 else
1361 {
1362 bh = &hi->root;
1363 if (! (_bfd_generic_link_add_one_symbol
1364 (info, abfd, shortname, BSF_INDIRECT,
1365 bfd_ind_section_ptr, 0, name, FALSE, collect, &bh)))
1366 return FALSE;
1367 hi = (struct elf_link_hash_entry *) bh;
1368
1369 /* If there is a duplicate definition somewhere, then HI may not
1370 point to an indirect symbol. We will have reported an error
1371 to the user in that case. */
1372
1373 if (hi->root.type == bfd_link_hash_indirect)
1374 {
1375 (*bed->elf_backend_copy_indirect_symbol) (bed, h, hi);
1376
1377 /* See if the new flags lead us to realize that the symbol
1378 must be dynamic. */
1379 if (! *dynsym)
1380 {
1381 if (! dynamic)
1382 {
1383 if (info->shared
1384 || ((hi->elf_link_hash_flags
1385 & ELF_LINK_HASH_REF_DYNAMIC) != 0))
1386 *dynsym = TRUE;
1387 }
1388 else
1389 {
1390 if ((hi->elf_link_hash_flags
1391 & ELF_LINK_HASH_REF_REGULAR) != 0)
1392 *dynsym = TRUE;
1393 }
1394 }
1395 }
1396 }
1397
1398 return TRUE;
1399 }
1400 \f
1401 /* This routine is used to export all defined symbols into the dynamic
1402 symbol table. It is called via elf_link_hash_traverse. */
1403
1404 bfd_boolean
1405 _bfd_elf_export_symbol (struct elf_link_hash_entry *h, void *data)
1406 {
1407 struct elf_info_failed *eif = data;
1408
1409 /* Ignore indirect symbols. These are added by the versioning code. */
1410 if (h->root.type == bfd_link_hash_indirect)
1411 return TRUE;
1412
1413 if (h->root.type == bfd_link_hash_warning)
1414 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1415
1416 if (h->dynindx == -1
1417 && (h->elf_link_hash_flags
1418 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
1419 {
1420 struct bfd_elf_version_tree *t;
1421 struct bfd_elf_version_expr *d;
1422
1423 for (t = eif->verdefs; t != NULL; t = t->next)
1424 {
1425 if (t->globals.list != NULL)
1426 {
1427 d = (*t->match) (&t->globals, NULL, h->root.root.string);
1428 if (d != NULL)
1429 goto doit;
1430 }
1431
1432 if (t->locals.list != NULL)
1433 {
1434 d = (*t->match) (&t->locals, NULL, h->root.root.string);
1435 if (d != NULL)
1436 return TRUE;
1437 }
1438 }
1439
1440 if (!eif->verdefs)
1441 {
1442 doit:
1443 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
1444 {
1445 eif->failed = TRUE;
1446 return FALSE;
1447 }
1448 }
1449 }
1450
1451 return TRUE;
1452 }
1453 \f
1454 /* Look through the symbols which are defined in other shared
1455 libraries and referenced here. Update the list of version
1456 dependencies. This will be put into the .gnu.version_r section.
1457 This function is called via elf_link_hash_traverse. */
1458
1459 bfd_boolean
1460 _bfd_elf_link_find_version_dependencies (struct elf_link_hash_entry *h,
1461 void *data)
1462 {
1463 struct elf_find_verdep_info *rinfo = data;
1464 Elf_Internal_Verneed *t;
1465 Elf_Internal_Vernaux *a;
1466 bfd_size_type amt;
1467
1468 if (h->root.type == bfd_link_hash_warning)
1469 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1470
1471 /* We only care about symbols defined in shared objects with version
1472 information. */
1473 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
1474 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
1475 || h->dynindx == -1
1476 || h->verinfo.verdef == NULL)
1477 return TRUE;
1478
1479 /* See if we already know about this version. */
1480 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
1481 {
1482 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
1483 continue;
1484
1485 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1486 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
1487 return TRUE;
1488
1489 break;
1490 }
1491
1492 /* This is a new version. Add it to tree we are building. */
1493
1494 if (t == NULL)
1495 {
1496 amt = sizeof *t;
1497 t = bfd_zalloc (rinfo->output_bfd, amt);
1498 if (t == NULL)
1499 {
1500 rinfo->failed = TRUE;
1501 return FALSE;
1502 }
1503
1504 t->vn_bfd = h->verinfo.verdef->vd_bfd;
1505 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
1506 elf_tdata (rinfo->output_bfd)->verref = t;
1507 }
1508
1509 amt = sizeof *a;
1510 a = bfd_zalloc (rinfo->output_bfd, amt);
1511
1512 /* Note that we are copying a string pointer here, and testing it
1513 above. If bfd_elf_string_from_elf_section is ever changed to
1514 discard the string data when low in memory, this will have to be
1515 fixed. */
1516 a->vna_nodename = h->verinfo.verdef->vd_nodename;
1517
1518 a->vna_flags = h->verinfo.verdef->vd_flags;
1519 a->vna_nextptr = t->vn_auxptr;
1520
1521 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
1522 ++rinfo->vers;
1523
1524 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
1525
1526 t->vn_auxptr = a;
1527
1528 return TRUE;
1529 }
1530
1531 /* Figure out appropriate versions for all the symbols. We may not
1532 have the version number script until we have read all of the input
1533 files, so until that point we don't know which symbols should be
1534 local. This function is called via elf_link_hash_traverse. */
1535
1536 bfd_boolean
1537 _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
1538 {
1539 struct elf_assign_sym_version_info *sinfo;
1540 struct bfd_link_info *info;
1541 const struct elf_backend_data *bed;
1542 struct elf_info_failed eif;
1543 char *p;
1544 bfd_size_type amt;
1545
1546 sinfo = data;
1547 info = sinfo->info;
1548
1549 if (h->root.type == bfd_link_hash_warning)
1550 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1551
1552 /* Fix the symbol flags. */
1553 eif.failed = FALSE;
1554 eif.info = info;
1555 if (! _bfd_elf_fix_symbol_flags (h, &eif))
1556 {
1557 if (eif.failed)
1558 sinfo->failed = TRUE;
1559 return FALSE;
1560 }
1561
1562 /* We only need version numbers for symbols defined in regular
1563 objects. */
1564 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1565 return TRUE;
1566
1567 bed = get_elf_backend_data (sinfo->output_bfd);
1568 p = strchr (h->root.root.string, ELF_VER_CHR);
1569 if (p != NULL && h->verinfo.vertree == NULL)
1570 {
1571 struct bfd_elf_version_tree *t;
1572 bfd_boolean hidden;
1573
1574 hidden = TRUE;
1575
1576 /* There are two consecutive ELF_VER_CHR characters if this is
1577 not a hidden symbol. */
1578 ++p;
1579 if (*p == ELF_VER_CHR)
1580 {
1581 hidden = FALSE;
1582 ++p;
1583 }
1584
1585 /* If there is no version string, we can just return out. */
1586 if (*p == '\0')
1587 {
1588 if (hidden)
1589 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
1590 return TRUE;
1591 }
1592
1593 /* Look for the version. If we find it, it is no longer weak. */
1594 for (t = sinfo->verdefs; t != NULL; t = t->next)
1595 {
1596 if (strcmp (t->name, p) == 0)
1597 {
1598 size_t len;
1599 char *alc;
1600 struct bfd_elf_version_expr *d;
1601
1602 len = p - h->root.root.string;
1603 alc = bfd_malloc (len);
1604 if (alc == NULL)
1605 return FALSE;
1606 memcpy (alc, h->root.root.string, len - 1);
1607 alc[len - 1] = '\0';
1608 if (alc[len - 2] == ELF_VER_CHR)
1609 alc[len - 2] = '\0';
1610
1611 h->verinfo.vertree = t;
1612 t->used = TRUE;
1613 d = NULL;
1614
1615 if (t->globals.list != NULL)
1616 d = (*t->match) (&t->globals, NULL, alc);
1617
1618 /* See if there is anything to force this symbol to
1619 local scope. */
1620 if (d == NULL && t->locals.list != NULL)
1621 {
1622 d = (*t->match) (&t->locals, NULL, alc);
1623 if (d != NULL
1624 && h->dynindx != -1
1625 && info->shared
1626 && ! info->export_dynamic)
1627 (*bed->elf_backend_hide_symbol) (info, h, TRUE);
1628 }
1629
1630 free (alc);
1631 break;
1632 }
1633 }
1634
1635 /* If we are building an application, we need to create a
1636 version node for this version. */
1637 if (t == NULL && info->executable)
1638 {
1639 struct bfd_elf_version_tree **pp;
1640 int version_index;
1641
1642 /* If we aren't going to export this symbol, we don't need
1643 to worry about it. */
1644 if (h->dynindx == -1)
1645 return TRUE;
1646
1647 amt = sizeof *t;
1648 t = bfd_zalloc (sinfo->output_bfd, amt);
1649 if (t == NULL)
1650 {
1651 sinfo->failed = TRUE;
1652 return FALSE;
1653 }
1654
1655 t->name = p;
1656 t->name_indx = (unsigned int) -1;
1657 t->used = TRUE;
1658
1659 version_index = 1;
1660 /* Don't count anonymous version tag. */
1661 if (sinfo->verdefs != NULL && sinfo->verdefs->vernum == 0)
1662 version_index = 0;
1663 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
1664 ++version_index;
1665 t->vernum = version_index;
1666
1667 *pp = t;
1668
1669 h->verinfo.vertree = t;
1670 }
1671 else if (t == NULL)
1672 {
1673 /* We could not find the version for a symbol when
1674 generating a shared archive. Return an error. */
1675 (*_bfd_error_handler)
1676 (_("%s: undefined versioned symbol name %s"),
1677 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
1678 bfd_set_error (bfd_error_bad_value);
1679 sinfo->failed = TRUE;
1680 return FALSE;
1681 }
1682
1683 if (hidden)
1684 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
1685 }
1686
1687 /* If we don't have a version for this symbol, see if we can find
1688 something. */
1689 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
1690 {
1691 struct bfd_elf_version_tree *t;
1692 struct bfd_elf_version_tree *local_ver;
1693 struct bfd_elf_version_expr *d;
1694
1695 /* See if can find what version this symbol is in. If the
1696 symbol is supposed to be local, then don't actually register
1697 it. */
1698 local_ver = NULL;
1699 for (t = sinfo->verdefs; t != NULL; t = t->next)
1700 {
1701 if (t->globals.list != NULL)
1702 {
1703 bfd_boolean matched;
1704
1705 matched = FALSE;
1706 d = NULL;
1707 while ((d = (*t->match) (&t->globals, d,
1708 h->root.root.string)) != NULL)
1709 if (d->symver)
1710 matched = TRUE;
1711 else
1712 {
1713 /* There is a version without definition. Make
1714 the symbol the default definition for this
1715 version. */
1716 h->verinfo.vertree = t;
1717 local_ver = NULL;
1718 d->script = 1;
1719 break;
1720 }
1721 if (d != NULL)
1722 break;
1723 else if (matched)
1724 /* There is no undefined version for this symbol. Hide the
1725 default one. */
1726 (*bed->elf_backend_hide_symbol) (info, h, TRUE);
1727 }
1728
1729 if (t->locals.list != NULL)
1730 {
1731 d = NULL;
1732 while ((d = (*t->match) (&t->locals, d,
1733 h->root.root.string)) != NULL)
1734 {
1735 local_ver = t;
1736 /* If the match is "*", keep looking for a more
1737 explicit, perhaps even global, match.
1738 XXX: Shouldn't this be !d->wildcard instead? */
1739 if (d->pattern[0] != '*' || d->pattern[1] != '\0')
1740 break;
1741 }
1742
1743 if (d != NULL)
1744 break;
1745 }
1746 }
1747
1748 if (local_ver != NULL)
1749 {
1750 h->verinfo.vertree = local_ver;
1751 if (h->dynindx != -1
1752 && info->shared
1753 && ! info->export_dynamic)
1754 {
1755 (*bed->elf_backend_hide_symbol) (info, h, TRUE);
1756 }
1757 }
1758 }
1759
1760 return TRUE;
1761 }
1762 \f
1763 /* Read and swap the relocs from the section indicated by SHDR. This
1764 may be either a REL or a RELA section. The relocations are
1765 translated into RELA relocations and stored in INTERNAL_RELOCS,
1766 which should have already been allocated to contain enough space.
1767 The EXTERNAL_RELOCS are a buffer where the external form of the
1768 relocations should be stored.
1769
1770 Returns FALSE if something goes wrong. */
1771
1772 static bfd_boolean
1773 elf_link_read_relocs_from_section (bfd *abfd,
1774 asection *sec,
1775 Elf_Internal_Shdr *shdr,
1776 void *external_relocs,
1777 Elf_Internal_Rela *internal_relocs)
1778 {
1779 const struct elf_backend_data *bed;
1780 void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
1781 const bfd_byte *erela;
1782 const bfd_byte *erelaend;
1783 Elf_Internal_Rela *irela;
1784 Elf_Internal_Shdr *symtab_hdr;
1785 size_t nsyms;
1786
1787 /* Position ourselves at the start of the section. */
1788 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
1789 return FALSE;
1790
1791 /* Read the relocations. */
1792 if (bfd_bread (external_relocs, shdr->sh_size, abfd) != shdr->sh_size)
1793 return FALSE;
1794
1795 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1796 nsyms = symtab_hdr->sh_size / symtab_hdr->sh_entsize;
1797
1798 bed = get_elf_backend_data (abfd);
1799
1800 /* Convert the external relocations to the internal format. */
1801 if (shdr->sh_entsize == bed->s->sizeof_rel)
1802 swap_in = bed->s->swap_reloc_in;
1803 else if (shdr->sh_entsize == bed->s->sizeof_rela)
1804 swap_in = bed->s->swap_reloca_in;
1805 else
1806 {
1807 bfd_set_error (bfd_error_wrong_format);
1808 return FALSE;
1809 }
1810
1811 erela = external_relocs;
1812 erelaend = erela + shdr->sh_size;
1813 irela = internal_relocs;
1814 while (erela < erelaend)
1815 {
1816 bfd_vma r_symndx;
1817
1818 (*swap_in) (abfd, erela, irela);
1819 r_symndx = ELF32_R_SYM (irela->r_info);
1820 if (bed->s->arch_size == 64)
1821 r_symndx >>= 24;
1822 if ((size_t) r_symndx >= nsyms)
1823 {
1824 (*_bfd_error_handler)
1825 (_("%s: bad reloc symbol index (0x%lx >= 0x%lx) for offset 0x%lx in section `%s'"),
1826 bfd_archive_filename (abfd), (unsigned long) r_symndx,
1827 (unsigned long) nsyms, irela->r_offset, sec->name);
1828 bfd_set_error (bfd_error_bad_value);
1829 return FALSE;
1830 }
1831 irela += bed->s->int_rels_per_ext_rel;
1832 erela += shdr->sh_entsize;
1833 }
1834
1835 return TRUE;
1836 }
1837
1838 /* Read and swap the relocs for a section O. They may have been
1839 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
1840 not NULL, they are used as buffers to read into. They are known to
1841 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
1842 the return value is allocated using either malloc or bfd_alloc,
1843 according to the KEEP_MEMORY argument. If O has two relocation
1844 sections (both REL and RELA relocations), then the REL_HDR
1845 relocations will appear first in INTERNAL_RELOCS, followed by the
1846 REL_HDR2 relocations. */
1847
1848 Elf_Internal_Rela *
1849 _bfd_elf_link_read_relocs (bfd *abfd,
1850 asection *o,
1851 void *external_relocs,
1852 Elf_Internal_Rela *internal_relocs,
1853 bfd_boolean keep_memory)
1854 {
1855 Elf_Internal_Shdr *rel_hdr;
1856 void *alloc1 = NULL;
1857 Elf_Internal_Rela *alloc2 = NULL;
1858 const struct elf_backend_data *bed = get_elf_backend_data (abfd);
1859
1860 if (elf_section_data (o)->relocs != NULL)
1861 return elf_section_data (o)->relocs;
1862
1863 if (o->reloc_count == 0)
1864 return NULL;
1865
1866 rel_hdr = &elf_section_data (o)->rel_hdr;
1867
1868 if (internal_relocs == NULL)
1869 {
1870 bfd_size_type size;
1871
1872 size = o->reloc_count;
1873 size *= bed->s->int_rels_per_ext_rel * sizeof (Elf_Internal_Rela);
1874 if (keep_memory)
1875 internal_relocs = bfd_alloc (abfd, size);
1876 else
1877 internal_relocs = alloc2 = bfd_malloc (size);
1878 if (internal_relocs == NULL)
1879 goto error_return;
1880 }
1881
1882 if (external_relocs == NULL)
1883 {
1884 bfd_size_type size = rel_hdr->sh_size;
1885
1886 if (elf_section_data (o)->rel_hdr2)
1887 size += elf_section_data (o)->rel_hdr2->sh_size;
1888 alloc1 = bfd_malloc (size);
1889 if (alloc1 == NULL)
1890 goto error_return;
1891 external_relocs = alloc1;
1892 }
1893
1894 if (!elf_link_read_relocs_from_section (abfd, o, rel_hdr,
1895 external_relocs,
1896 internal_relocs))
1897 goto error_return;
1898 if (elf_section_data (o)->rel_hdr2
1899 && (!elf_link_read_relocs_from_section
1900 (abfd, o,
1901 elf_section_data (o)->rel_hdr2,
1902 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
1903 internal_relocs + (NUM_SHDR_ENTRIES (rel_hdr)
1904 * bed->s->int_rels_per_ext_rel))))
1905 goto error_return;
1906
1907 /* Cache the results for next time, if we can. */
1908 if (keep_memory)
1909 elf_section_data (o)->relocs = internal_relocs;
1910
1911 if (alloc1 != NULL)
1912 free (alloc1);
1913
1914 /* Don't free alloc2, since if it was allocated we are passing it
1915 back (under the name of internal_relocs). */
1916
1917 return internal_relocs;
1918
1919 error_return:
1920 if (alloc1 != NULL)
1921 free (alloc1);
1922 if (alloc2 != NULL)
1923 free (alloc2);
1924 return NULL;
1925 }
1926
1927 /* Compute the size of, and allocate space for, REL_HDR which is the
1928 section header for a section containing relocations for O. */
1929
1930 bfd_boolean
1931 _bfd_elf_link_size_reloc_section (bfd *abfd,
1932 Elf_Internal_Shdr *rel_hdr,
1933 asection *o)
1934 {
1935 bfd_size_type reloc_count;
1936 bfd_size_type num_rel_hashes;
1937
1938 /* Figure out how many relocations there will be. */
1939 if (rel_hdr == &elf_section_data (o)->rel_hdr)
1940 reloc_count = elf_section_data (o)->rel_count;
1941 else
1942 reloc_count = elf_section_data (o)->rel_count2;
1943
1944 num_rel_hashes = o->reloc_count;
1945 if (num_rel_hashes < reloc_count)
1946 num_rel_hashes = reloc_count;
1947
1948 /* That allows us to calculate the size of the section. */
1949 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
1950
1951 /* The contents field must last into write_object_contents, so we
1952 allocate it with bfd_alloc rather than malloc. Also since we
1953 cannot be sure that the contents will actually be filled in,
1954 we zero the allocated space. */
1955 rel_hdr->contents = bfd_zalloc (abfd, rel_hdr->sh_size);
1956 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
1957 return FALSE;
1958
1959 /* We only allocate one set of hash entries, so we only do it the
1960 first time we are called. */
1961 if (elf_section_data (o)->rel_hashes == NULL
1962 && num_rel_hashes)
1963 {
1964 struct elf_link_hash_entry **p;
1965
1966 p = bfd_zmalloc (num_rel_hashes * sizeof (struct elf_link_hash_entry *));
1967 if (p == NULL)
1968 return FALSE;
1969
1970 elf_section_data (o)->rel_hashes = p;
1971 }
1972
1973 return TRUE;
1974 }
1975
1976 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
1977 originated from the section given by INPUT_REL_HDR) to the
1978 OUTPUT_BFD. */
1979
1980 bfd_boolean
1981 _bfd_elf_link_output_relocs (bfd *output_bfd,
1982 asection *input_section,
1983 Elf_Internal_Shdr *input_rel_hdr,
1984 Elf_Internal_Rela *internal_relocs)
1985 {
1986 Elf_Internal_Rela *irela;
1987 Elf_Internal_Rela *irelaend;
1988 bfd_byte *erel;
1989 Elf_Internal_Shdr *output_rel_hdr;
1990 asection *output_section;
1991 unsigned int *rel_countp = NULL;
1992 const struct elf_backend_data *bed;
1993 void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
1994
1995 output_section = input_section->output_section;
1996 output_rel_hdr = NULL;
1997
1998 if (elf_section_data (output_section)->rel_hdr.sh_entsize
1999 == input_rel_hdr->sh_entsize)
2000 {
2001 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
2002 rel_countp = &elf_section_data (output_section)->rel_count;
2003 }
2004 else if (elf_section_data (output_section)->rel_hdr2
2005 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
2006 == input_rel_hdr->sh_entsize))
2007 {
2008 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
2009 rel_countp = &elf_section_data (output_section)->rel_count2;
2010 }
2011 else
2012 {
2013 (*_bfd_error_handler)
2014 (_("%s: relocation size mismatch in %s section %s"),
2015 bfd_get_filename (output_bfd),
2016 bfd_archive_filename (input_section->owner),
2017 input_section->name);
2018 bfd_set_error (bfd_error_wrong_object_format);
2019 return FALSE;
2020 }
2021
2022 bed = get_elf_backend_data (output_bfd);
2023 if (input_rel_hdr->sh_entsize == bed->s->sizeof_rel)
2024 swap_out = bed->s->swap_reloc_out;
2025 else if (input_rel_hdr->sh_entsize == bed->s->sizeof_rela)
2026 swap_out = bed->s->swap_reloca_out;
2027 else
2028 abort ();
2029
2030 erel = output_rel_hdr->contents;
2031 erel += *rel_countp * input_rel_hdr->sh_entsize;
2032 irela = internal_relocs;
2033 irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr)
2034 * bed->s->int_rels_per_ext_rel);
2035 while (irela < irelaend)
2036 {
2037 (*swap_out) (output_bfd, irela, erel);
2038 irela += bed->s->int_rels_per_ext_rel;
2039 erel += input_rel_hdr->sh_entsize;
2040 }
2041
2042 /* Bump the counter, so that we know where to add the next set of
2043 relocations. */
2044 *rel_countp += NUM_SHDR_ENTRIES (input_rel_hdr);
2045
2046 return TRUE;
2047 }
2048 \f
2049 /* Fix up the flags for a symbol. This handles various cases which
2050 can only be fixed after all the input files are seen. This is
2051 currently called by both adjust_dynamic_symbol and
2052 assign_sym_version, which is unnecessary but perhaps more robust in
2053 the face of future changes. */
2054
2055 bfd_boolean
2056 _bfd_elf_fix_symbol_flags (struct elf_link_hash_entry *h,
2057 struct elf_info_failed *eif)
2058 {
2059 /* If this symbol was mentioned in a non-ELF file, try to set
2060 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
2061 permit a non-ELF file to correctly refer to a symbol defined in
2062 an ELF dynamic object. */
2063 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
2064 {
2065 while (h->root.type == bfd_link_hash_indirect)
2066 h = (struct elf_link_hash_entry *) h->root.u.i.link;
2067
2068 if (h->root.type != bfd_link_hash_defined
2069 && h->root.type != bfd_link_hash_defweak)
2070 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
2071 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
2072 else
2073 {
2074 if (h->root.u.def.section->owner != NULL
2075 && (bfd_get_flavour (h->root.u.def.section->owner)
2076 == bfd_target_elf_flavour))
2077 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
2078 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
2079 else
2080 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2081 }
2082
2083 if (h->dynindx == -1
2084 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2085 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
2086 {
2087 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
2088 {
2089 eif->failed = TRUE;
2090 return FALSE;
2091 }
2092 }
2093 }
2094 else
2095 {
2096 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
2097 was first seen in a non-ELF file. Fortunately, if the symbol
2098 was first seen in an ELF file, we're probably OK unless the
2099 symbol was defined in a non-ELF file. Catch that case here.
2100 FIXME: We're still in trouble if the symbol was first seen in
2101 a dynamic object, and then later in a non-ELF regular object. */
2102 if ((h->root.type == bfd_link_hash_defined
2103 || h->root.type == bfd_link_hash_defweak)
2104 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
2105 && (h->root.u.def.section->owner != NULL
2106 ? (bfd_get_flavour (h->root.u.def.section->owner)
2107 != bfd_target_elf_flavour)
2108 : (bfd_is_abs_section (h->root.u.def.section)
2109 && (h->elf_link_hash_flags
2110 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
2111 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2112 }
2113
2114 /* If this is a final link, and the symbol was defined as a common
2115 symbol in a regular object file, and there was no definition in
2116 any dynamic object, then the linker will have allocated space for
2117 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
2118 flag will not have been set. */
2119 if (h->root.type == bfd_link_hash_defined
2120 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
2121 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
2122 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
2123 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
2124 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2125
2126 /* If -Bsymbolic was used (which means to bind references to global
2127 symbols to the definition within the shared object), and this
2128 symbol was defined in a regular object, then it actually doesn't
2129 need a PLT entry. Likewise, if the symbol has non-default
2130 visibility. If the symbol has hidden or internal visibility, we
2131 will force it local. */
2132 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
2133 && eif->info->shared
2134 && is_elf_hash_table (eif->info->hash)
2135 && (eif->info->symbolic
2136 || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
2137 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
2138 {
2139 const struct elf_backend_data *bed;
2140 bfd_boolean force_local;
2141
2142 bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
2143
2144 force_local = (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
2145 || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN);
2146 (*bed->elf_backend_hide_symbol) (eif->info, h, force_local);
2147 }
2148
2149 /* If a weak undefined symbol has non-default visibility, we also
2150 hide it from the dynamic linker. */
2151 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
2152 && h->root.type == bfd_link_hash_undefweak)
2153 {
2154 const struct elf_backend_data *bed;
2155 bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
2156 (*bed->elf_backend_hide_symbol) (eif->info, h, TRUE);
2157 }
2158
2159 /* If this is a weak defined symbol in a dynamic object, and we know
2160 the real definition in the dynamic object, copy interesting flags
2161 over to the real definition. */
2162 if (h->weakdef != NULL)
2163 {
2164 struct elf_link_hash_entry *weakdef;
2165
2166 weakdef = h->weakdef;
2167 if (h->root.type == bfd_link_hash_indirect)
2168 h = (struct elf_link_hash_entry *) h->root.u.i.link;
2169
2170 BFD_ASSERT (h->root.type == bfd_link_hash_defined
2171 || h->root.type == bfd_link_hash_defweak);
2172 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
2173 || weakdef->root.type == bfd_link_hash_defweak);
2174 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
2175
2176 /* If the real definition is defined by a regular object file,
2177 don't do anything special. See the longer description in
2178 _bfd_elf_adjust_dynamic_symbol, below. */
2179 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
2180 h->weakdef = NULL;
2181 else
2182 {
2183 const struct elf_backend_data *bed;
2184
2185 bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
2186 (*bed->elf_backend_copy_indirect_symbol) (bed, weakdef, h);
2187 }
2188 }
2189
2190 return TRUE;
2191 }
2192
2193 /* Make the backend pick a good value for a dynamic symbol. This is
2194 called via elf_link_hash_traverse, and also calls itself
2195 recursively. */
2196
2197 bfd_boolean
2198 _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data)
2199 {
2200 struct elf_info_failed *eif = data;
2201 bfd *dynobj;
2202 const struct elf_backend_data *bed;
2203
2204 if (! is_elf_hash_table (eif->info->hash))
2205 return FALSE;
2206
2207 if (h->root.type == bfd_link_hash_warning)
2208 {
2209 h->plt = elf_hash_table (eif->info)->init_offset;
2210 h->got = elf_hash_table (eif->info)->init_offset;
2211
2212 /* When warning symbols are created, they **replace** the "real"
2213 entry in the hash table, thus we never get to see the real
2214 symbol in a hash traversal. So look at it now. */
2215 h = (struct elf_link_hash_entry *) h->root.u.i.link;
2216 }
2217
2218 /* Ignore indirect symbols. These are added by the versioning code. */
2219 if (h->root.type == bfd_link_hash_indirect)
2220 return TRUE;
2221
2222 /* Fix the symbol flags. */
2223 if (! _bfd_elf_fix_symbol_flags (h, eif))
2224 return FALSE;
2225
2226 /* If this symbol does not require a PLT entry, and it is not
2227 defined by a dynamic object, or is not referenced by a regular
2228 object, ignore it. We do have to handle a weak defined symbol,
2229 even if no regular object refers to it, if we decided to add it
2230 to the dynamic symbol table. FIXME: Do we normally need to worry
2231 about symbols which are defined by one dynamic object and
2232 referenced by another one? */
2233 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
2234 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
2235 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
2236 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
2237 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
2238 {
2239 h->plt = elf_hash_table (eif->info)->init_offset;
2240 return TRUE;
2241 }
2242
2243 /* If we've already adjusted this symbol, don't do it again. This
2244 can happen via a recursive call. */
2245 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
2246 return TRUE;
2247
2248 /* Don't look at this symbol again. Note that we must set this
2249 after checking the above conditions, because we may look at a
2250 symbol once, decide not to do anything, and then get called
2251 recursively later after REF_REGULAR is set below. */
2252 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
2253
2254 /* If this is a weak definition, and we know a real definition, and
2255 the real symbol is not itself defined by a regular object file,
2256 then get a good value for the real definition. We handle the
2257 real symbol first, for the convenience of the backend routine.
2258
2259 Note that there is a confusing case here. If the real definition
2260 is defined by a regular object file, we don't get the real symbol
2261 from the dynamic object, but we do get the weak symbol. If the
2262 processor backend uses a COPY reloc, then if some routine in the
2263 dynamic object changes the real symbol, we will not see that
2264 change in the corresponding weak symbol. This is the way other
2265 ELF linkers work as well, and seems to be a result of the shared
2266 library model.
2267
2268 I will clarify this issue. Most SVR4 shared libraries define the
2269 variable _timezone and define timezone as a weak synonym. The
2270 tzset call changes _timezone. If you write
2271 extern int timezone;
2272 int _timezone = 5;
2273 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
2274 you might expect that, since timezone is a synonym for _timezone,
2275 the same number will print both times. However, if the processor
2276 backend uses a COPY reloc, then actually timezone will be copied
2277 into your process image, and, since you define _timezone
2278 yourself, _timezone will not. Thus timezone and _timezone will
2279 wind up at different memory locations. The tzset call will set
2280 _timezone, leaving timezone unchanged. */
2281
2282 if (h->weakdef != NULL)
2283 {
2284 /* If we get to this point, we know there is an implicit
2285 reference by a regular object file via the weak symbol H.
2286 FIXME: Is this really true? What if the traversal finds
2287 H->WEAKDEF before it finds H? */
2288 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
2289
2290 if (! _bfd_elf_adjust_dynamic_symbol (h->weakdef, eif))
2291 return FALSE;
2292 }
2293
2294 /* If a symbol has no type and no size and does not require a PLT
2295 entry, then we are probably about to do the wrong thing here: we
2296 are probably going to create a COPY reloc for an empty object.
2297 This case can arise when a shared object is built with assembly
2298 code, and the assembly code fails to set the symbol type. */
2299 if (h->size == 0
2300 && h->type == STT_NOTYPE
2301 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
2302 (*_bfd_error_handler)
2303 (_("warning: type and size of dynamic symbol `%s' are not defined"),
2304 h->root.root.string);
2305
2306 dynobj = elf_hash_table (eif->info)->dynobj;
2307 bed = get_elf_backend_data (dynobj);
2308 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
2309 {
2310 eif->failed = TRUE;
2311 return FALSE;
2312 }
2313
2314 return TRUE;
2315 }
2316
2317 /* Adjust all external symbols pointing into SEC_MERGE sections
2318 to reflect the object merging within the sections. */
2319
2320 bfd_boolean
2321 _bfd_elf_link_sec_merge_syms (struct elf_link_hash_entry *h, void *data)
2322 {
2323 asection *sec;
2324
2325 if (h->root.type == bfd_link_hash_warning)
2326 h = (struct elf_link_hash_entry *) h->root.u.i.link;
2327
2328 if ((h->root.type == bfd_link_hash_defined
2329 || h->root.type == bfd_link_hash_defweak)
2330 && ((sec = h->root.u.def.section)->flags & SEC_MERGE)
2331 && sec->sec_info_type == ELF_INFO_TYPE_MERGE)
2332 {
2333 bfd *output_bfd = data;
2334
2335 h->root.u.def.value =
2336 _bfd_merged_section_offset (output_bfd,
2337 &h->root.u.def.section,
2338 elf_section_data (sec)->sec_info,
2339 h->root.u.def.value, 0);
2340 }
2341
2342 return TRUE;
2343 }
2344
2345 /* Returns false if the symbol referred to by H should be considered
2346 to resolve local to the current module, and true if it should be
2347 considered to bind dynamically. */
2348
2349 bfd_boolean
2350 _bfd_elf_dynamic_symbol_p (struct elf_link_hash_entry *h,
2351 struct bfd_link_info *info,
2352 bfd_boolean ignore_protected)
2353 {
2354 bfd_boolean binding_stays_local_p;
2355
2356 if (h == NULL)
2357 return FALSE;
2358
2359 while (h->root.type == bfd_link_hash_indirect
2360 || h->root.type == bfd_link_hash_warning)
2361 h = (struct elf_link_hash_entry *) h->root.u.i.link;
2362
2363 /* If it was forced local, then clearly it's not dynamic. */
2364 if (h->dynindx == -1)
2365 return FALSE;
2366 if (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL)
2367 return FALSE;
2368
2369 /* Identify the cases where name binding rules say that a
2370 visible symbol resolves locally. */
2371 binding_stays_local_p = info->executable || info->symbolic;
2372
2373 switch (ELF_ST_VISIBILITY (h->other))
2374 {
2375 case STV_INTERNAL:
2376 case STV_HIDDEN:
2377 return FALSE;
2378
2379 case STV_PROTECTED:
2380 /* Proper resolution for function pointer equality may require
2381 that these symbols perhaps be resolved dynamically, even though
2382 we should be resolving them to the current module. */
2383 if (!ignore_protected)
2384 binding_stays_local_p = TRUE;
2385 break;
2386
2387 default:
2388 break;
2389 }
2390
2391 /* If it isn't defined locally, then clearly it's dynamic. */
2392 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2393 return TRUE;
2394
2395 /* Otherwise, the symbol is dynamic if binding rules don't tell
2396 us that it remains local. */
2397 return !binding_stays_local_p;
2398 }
2399
2400 /* Return true if the symbol referred to by H should be considered
2401 to resolve local to the current module, and false otherwise. Differs
2402 from (the inverse of) _bfd_elf_dynamic_symbol_p in the treatment of
2403 undefined symbols and weak symbols. */
2404
2405 bfd_boolean
2406 _bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h,
2407 struct bfd_link_info *info,
2408 bfd_boolean local_protected)
2409 {
2410 /* If it's a local sym, of course we resolve locally. */
2411 if (h == NULL)
2412 return TRUE;
2413
2414 /* If we don't have a definition in a regular file, then we can't
2415 resolve locally. The sym is either undefined or dynamic. */
2416 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2417 return FALSE;
2418
2419 /* Forced local symbols resolve locally. */
2420 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
2421 return TRUE;
2422
2423 /* As do non-dynamic symbols. */
2424 if (h->dynindx == -1)
2425 return TRUE;
2426
2427 /* At this point, we know the symbol is defined and dynamic. In an
2428 executable it must resolve locally, likewise when building symbolic
2429 shared libraries. */
2430 if (info->executable || info->symbolic)
2431 return TRUE;
2432
2433 /* Now deal with defined dynamic symbols in shared libraries. Ones
2434 with default visibility might not resolve locally. */
2435 if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
2436 return FALSE;
2437
2438 /* However, STV_HIDDEN or STV_INTERNAL ones must be local. */
2439 if (ELF_ST_VISIBILITY (h->other) != STV_PROTECTED)
2440 return TRUE;
2441
2442 /* Function pointer equality tests may require that STV_PROTECTED
2443 symbols be treated as dynamic symbols, even when we know that the
2444 dynamic linker will resolve them locally. */
2445 return local_protected;
2446 }
2447
2448 /* Caches some TLS segment info, and ensures that the TLS segment vma is
2449 aligned. Returns the first TLS output section. */
2450
2451 struct bfd_section *
2452 _bfd_elf_tls_setup (bfd *obfd, struct bfd_link_info *info)
2453 {
2454 struct bfd_section *sec, *tls;
2455 unsigned int align = 0;
2456
2457 for (sec = obfd->sections; sec != NULL; sec = sec->next)
2458 if ((sec->flags & SEC_THREAD_LOCAL) != 0)
2459 break;
2460 tls = sec;
2461
2462 for (; sec != NULL && (sec->flags & SEC_THREAD_LOCAL) != 0; sec = sec->next)
2463 if (sec->alignment_power > align)
2464 align = sec->alignment_power;
2465
2466 elf_hash_table (info)->tls_sec = tls;
2467
2468 /* Ensure the alignment of the first section is the largest alignment,
2469 so that the tls segment starts aligned. */
2470 if (tls != NULL)
2471 tls->alignment_power = align;
2472
2473 return tls;
2474 }
2475
2476 /* Return TRUE iff this is a non-common, definition of a non-function symbol. */
2477 static bfd_boolean
2478 is_global_data_symbol_definition (bfd *abfd ATTRIBUTE_UNUSED,
2479 Elf_Internal_Sym *sym)
2480 {
2481 /* Local symbols do not count, but target specific ones might. */
2482 if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
2483 && ELF_ST_BIND (sym->st_info) < STB_LOOS)
2484 return FALSE;
2485
2486 /* Function symbols do not count. */
2487 if (ELF_ST_TYPE (sym->st_info) == STT_FUNC)
2488 return FALSE;
2489
2490 /* If the section is undefined, then so is the symbol. */
2491 if (sym->st_shndx == SHN_UNDEF)
2492 return FALSE;
2493
2494 /* If the symbol is defined in the common section, then
2495 it is a common definition and so does not count. */
2496 if (sym->st_shndx == SHN_COMMON)
2497 return FALSE;
2498
2499 /* If the symbol is in a target specific section then we
2500 must rely upon the backend to tell us what it is. */
2501 if (sym->st_shndx >= SHN_LORESERVE && sym->st_shndx < SHN_ABS)
2502 /* FIXME - this function is not coded yet:
2503
2504 return _bfd_is_global_symbol_definition (abfd, sym);
2505
2506 Instead for now assume that the definition is not global,
2507 Even if this is wrong, at least the linker will behave
2508 in the same way that it used to do. */
2509 return FALSE;
2510
2511 return TRUE;
2512 }
2513
2514 /* Search the symbol table of the archive element of the archive ABFD
2515 whose archive map contains a mention of SYMDEF, and determine if
2516 the symbol is defined in this element. */
2517 static bfd_boolean
2518 elf_link_is_defined_archive_symbol (bfd * abfd, carsym * symdef)
2519 {
2520 Elf_Internal_Shdr * hdr;
2521 bfd_size_type symcount;
2522 bfd_size_type extsymcount;
2523 bfd_size_type extsymoff;
2524 Elf_Internal_Sym *isymbuf;
2525 Elf_Internal_Sym *isym;
2526 Elf_Internal_Sym *isymend;
2527 bfd_boolean result;
2528
2529 abfd = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
2530 if (abfd == NULL)
2531 return FALSE;
2532
2533 if (! bfd_check_format (abfd, bfd_object))
2534 return FALSE;
2535
2536 /* If we have already included the element containing this symbol in the
2537 link then we do not need to include it again. Just claim that any symbol
2538 it contains is not a definition, so that our caller will not decide to
2539 (re)include this element. */
2540 if (abfd->archive_pass)
2541 return FALSE;
2542
2543 /* Select the appropriate symbol table. */
2544 if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
2545 hdr = &elf_tdata (abfd)->symtab_hdr;
2546 else
2547 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
2548
2549 symcount = hdr->sh_size / get_elf_backend_data (abfd)->s->sizeof_sym;
2550
2551 /* The sh_info field of the symtab header tells us where the
2552 external symbols start. We don't care about the local symbols. */
2553 if (elf_bad_symtab (abfd))
2554 {
2555 extsymcount = symcount;
2556 extsymoff = 0;
2557 }
2558 else
2559 {
2560 extsymcount = symcount - hdr->sh_info;
2561 extsymoff = hdr->sh_info;
2562 }
2563
2564 if (extsymcount == 0)
2565 return FALSE;
2566
2567 /* Read in the symbol table. */
2568 isymbuf = bfd_elf_get_elf_syms (abfd, hdr, extsymcount, extsymoff,
2569 NULL, NULL, NULL);
2570 if (isymbuf == NULL)
2571 return FALSE;
2572
2573 /* Scan the symbol table looking for SYMDEF. */
2574 result = FALSE;
2575 for (isym = isymbuf, isymend = isymbuf + extsymcount; isym < isymend; isym++)
2576 {
2577 const char *name;
2578
2579 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link,
2580 isym->st_name);
2581 if (name == NULL)
2582 break;
2583
2584 if (strcmp (name, symdef->name) == 0)
2585 {
2586 result = is_global_data_symbol_definition (abfd, isym);
2587 break;
2588 }
2589 }
2590
2591 free (isymbuf);
2592
2593 return result;
2594 }
2595 \f
2596 /* Add symbols from an ELF archive file to the linker hash table. We
2597 don't use _bfd_generic_link_add_archive_symbols because of a
2598 problem which arises on UnixWare. The UnixWare libc.so is an
2599 archive which includes an entry libc.so.1 which defines a bunch of
2600 symbols. The libc.so archive also includes a number of other
2601 object files, which also define symbols, some of which are the same
2602 as those defined in libc.so.1. Correct linking requires that we
2603 consider each object file in turn, and include it if it defines any
2604 symbols we need. _bfd_generic_link_add_archive_symbols does not do
2605 this; it looks through the list of undefined symbols, and includes
2606 any object file which defines them. When this algorithm is used on
2607 UnixWare, it winds up pulling in libc.so.1 early and defining a
2608 bunch of symbols. This means that some of the other objects in the
2609 archive are not included in the link, which is incorrect since they
2610 precede libc.so.1 in the archive.
2611
2612 Fortunately, ELF archive handling is simpler than that done by
2613 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
2614 oddities. In ELF, if we find a symbol in the archive map, and the
2615 symbol is currently undefined, we know that we must pull in that
2616 object file.
2617
2618 Unfortunately, we do have to make multiple passes over the symbol
2619 table until nothing further is resolved. */
2620
2621 bfd_boolean
2622 _bfd_elf_link_add_archive_symbols (bfd *abfd,
2623 struct bfd_link_info *info)
2624 {
2625 symindex c;
2626 bfd_boolean *defined = NULL;
2627 bfd_boolean *included = NULL;
2628 carsym *symdefs;
2629 bfd_boolean loop;
2630 bfd_size_type amt;
2631
2632 if (! bfd_has_map (abfd))
2633 {
2634 /* An empty archive is a special case. */
2635 if (bfd_openr_next_archived_file (abfd, NULL) == NULL)
2636 return TRUE;
2637 bfd_set_error (bfd_error_no_armap);
2638 return FALSE;
2639 }
2640
2641 /* Keep track of all symbols we know to be already defined, and all
2642 files we know to be already included. This is to speed up the
2643 second and subsequent passes. */
2644 c = bfd_ardata (abfd)->symdef_count;
2645 if (c == 0)
2646 return TRUE;
2647 amt = c;
2648 amt *= sizeof (bfd_boolean);
2649 defined = bfd_zmalloc (amt);
2650 included = bfd_zmalloc (amt);
2651 if (defined == NULL || included == NULL)
2652 goto error_return;
2653
2654 symdefs = bfd_ardata (abfd)->symdefs;
2655
2656 do
2657 {
2658 file_ptr last;
2659 symindex i;
2660 carsym *symdef;
2661 carsym *symdefend;
2662
2663 loop = FALSE;
2664 last = -1;
2665
2666 symdef = symdefs;
2667 symdefend = symdef + c;
2668 for (i = 0; symdef < symdefend; symdef++, i++)
2669 {
2670 struct elf_link_hash_entry *h;
2671 bfd *element;
2672 struct bfd_link_hash_entry *undefs_tail;
2673 symindex mark;
2674
2675 if (defined[i] || included[i])
2676 continue;
2677 if (symdef->file_offset == last)
2678 {
2679 included[i] = TRUE;
2680 continue;
2681 }
2682
2683 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
2684 FALSE, FALSE, FALSE);
2685
2686 if (h == NULL)
2687 {
2688 char *p, *copy;
2689 size_t len, first;
2690
2691 /* If this is a default version (the name contains @@),
2692 look up the symbol again with only one `@' as well
2693 as without the version. The effect is that references
2694 to the symbol with and without the version will be
2695 matched by the default symbol in the archive. */
2696
2697 p = strchr (symdef->name, ELF_VER_CHR);
2698 if (p == NULL || p[1] != ELF_VER_CHR)
2699 continue;
2700
2701 /* First check with only one `@'. */
2702 len = strlen (symdef->name);
2703 copy = bfd_alloc (abfd, len);
2704 if (copy == NULL)
2705 goto error_return;
2706 first = p - symdef->name + 1;
2707 memcpy (copy, symdef->name, first);
2708 memcpy (copy + first, symdef->name + first + 1, len - first);
2709
2710 h = elf_link_hash_lookup (elf_hash_table (info), copy,
2711 FALSE, FALSE, FALSE);
2712
2713 if (h == NULL)
2714 {
2715 /* We also need to check references to the symbol
2716 without the version. */
2717
2718 copy[first - 1] = '\0';
2719 h = elf_link_hash_lookup (elf_hash_table (info),
2720 copy, FALSE, FALSE, FALSE);
2721 }
2722
2723 bfd_release (abfd, copy);
2724 }
2725
2726 if (h == NULL)
2727 continue;
2728
2729 if (h->root.type == bfd_link_hash_common)
2730 {
2731 /* We currently have a common symbol. The archive map contains
2732 a reference to this symbol, so we may want to include it. We
2733 only want to include it however, if this archive element
2734 contains a definition of the symbol, not just another common
2735 declaration of it.
2736
2737 Unfortunately some archivers (including GNU ar) will put
2738 declarations of common symbols into their archive maps, as
2739 well as real definitions, so we cannot just go by the archive
2740 map alone. Instead we must read in the element's symbol
2741 table and check that to see what kind of symbol definition
2742 this is. */
2743 if (! elf_link_is_defined_archive_symbol (abfd, symdef))
2744 continue;
2745 }
2746 else if (h->root.type != bfd_link_hash_undefined)
2747 {
2748 if (h->root.type != bfd_link_hash_undefweak)
2749 defined[i] = TRUE;
2750 continue;
2751 }
2752
2753 /* We need to include this archive member. */
2754 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
2755 if (element == NULL)
2756 goto error_return;
2757
2758 if (! bfd_check_format (element, bfd_object))
2759 goto error_return;
2760
2761 /* Doublecheck that we have not included this object
2762 already--it should be impossible, but there may be
2763 something wrong with the archive. */
2764 if (element->archive_pass != 0)
2765 {
2766 bfd_set_error (bfd_error_bad_value);
2767 goto error_return;
2768 }
2769 element->archive_pass = 1;
2770
2771 undefs_tail = info->hash->undefs_tail;
2772
2773 if (! (*info->callbacks->add_archive_element) (info, element,
2774 symdef->name))
2775 goto error_return;
2776 if (! bfd_link_add_symbols (element, info))
2777 goto error_return;
2778
2779 /* If there are any new undefined symbols, we need to make
2780 another pass through the archive in order to see whether
2781 they can be defined. FIXME: This isn't perfect, because
2782 common symbols wind up on undefs_tail and because an
2783 undefined symbol which is defined later on in this pass
2784 does not require another pass. This isn't a bug, but it
2785 does make the code less efficient than it could be. */
2786 if (undefs_tail != info->hash->undefs_tail)
2787 loop = TRUE;
2788
2789 /* Look backward to mark all symbols from this object file
2790 which we have already seen in this pass. */
2791 mark = i;
2792 do
2793 {
2794 included[mark] = TRUE;
2795 if (mark == 0)
2796 break;
2797 --mark;
2798 }
2799 while (symdefs[mark].file_offset == symdef->file_offset);
2800
2801 /* We mark subsequent symbols from this object file as we go
2802 on through the loop. */
2803 last = symdef->file_offset;
2804 }
2805 }
2806 while (loop);
2807
2808 free (defined);
2809 free (included);
2810
2811 return TRUE;
2812
2813 error_return:
2814 if (defined != NULL)
2815 free (defined);
2816 if (included != NULL)
2817 free (included);
2818 return FALSE;
2819 }