1aaa17ed08e29b146d19cbc38a0940e42619f3ef
[binutils-gdb.git] / bfd / elflink.h
1 /* ELF linker support.
2 Copyright 1995 Free Software Foundation, Inc.
3
4 This file is part of BFD, the Binary File Descriptor library.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
19
20 /* ELF linker code. */
21
22 static boolean elf_link_add_object_symbols
23 PARAMS ((bfd *, struct bfd_link_info *));
24 static boolean elf_link_add_archive_symbols
25 PARAMS ((bfd *, struct bfd_link_info *));
26 static Elf_Internal_Rela *elf_link_read_relocs
27 PARAMS ((bfd *, asection *, PTR, Elf_Internal_Rela *, boolean));
28 static boolean elf_export_symbol
29 PARAMS ((struct elf_link_hash_entry *, PTR));
30 static boolean elf_adjust_dynamic_symbol
31 PARAMS ((struct elf_link_hash_entry *, PTR));
32
33 /* This struct is used to pass information to routines called via
34 elf_link_hash_traverse which must return failure. */
35
36 struct elf_info_failed
37 {
38 boolean failed;
39 struct bfd_link_info *info;
40 };
41
42 /* Given an ELF BFD, add symbols to the global hash table as
43 appropriate. */
44
45 boolean
46 elf_bfd_link_add_symbols (abfd, info)
47 bfd *abfd;
48 struct bfd_link_info *info;
49 {
50 switch (bfd_get_format (abfd))
51 {
52 case bfd_object:
53 return elf_link_add_object_symbols (abfd, info);
54 case bfd_archive:
55 return elf_link_add_archive_symbols (abfd, info);
56 default:
57 bfd_set_error (bfd_error_wrong_format);
58 return false;
59 }
60 }
61
62 /* Add symbols from an ELF archive file to the linker hash table. We
63 don't use _bfd_generic_link_add_archive_symbols because of a
64 problem which arises on UnixWare. The UnixWare libc.so is an
65 archive which includes an entry libc.so.1 which defines a bunch of
66 symbols. The libc.so archive also includes a number of other
67 object files, which also define symbols, some of which are the same
68 as those defined in libc.so.1. Correct linking requires that we
69 consider each object file in turn, and include it if it defines any
70 symbols we need. _bfd_generic_link_add_archive_symbols does not do
71 this; it looks through the list of undefined symbols, and includes
72 any object file which defines them. When this algorithm is used on
73 UnixWare, it winds up pulling in libc.so.1 early and defining a
74 bunch of symbols. This means that some of the other objects in the
75 archive are not included in the link, which is incorrect since they
76 precede libc.so.1 in the archive.
77
78 Fortunately, ELF archive handling is simpler than that done by
79 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
80 oddities. In ELF, if we find a symbol in the archive map, and the
81 symbol is currently undefined, we know that we must pull in that
82 object file.
83
84 Unfortunately, we do have to make multiple passes over the symbol
85 table until nothing further is resolved. */
86
87 static boolean
88 elf_link_add_archive_symbols (abfd, info)
89 bfd *abfd;
90 struct bfd_link_info *info;
91 {
92 symindex c;
93 boolean *defined = NULL;
94 boolean *included = NULL;
95 carsym *symdefs;
96 boolean loop;
97
98 if (! bfd_has_map (abfd))
99 {
100 /* An empty archive is a special case. */
101 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
102 return true;
103 bfd_set_error (bfd_error_no_armap);
104 return false;
105 }
106
107 /* Keep track of all symbols we know to be already defined, and all
108 files we know to be already included. This is to speed up the
109 second and subsequent passes. */
110 c = bfd_ardata (abfd)->symdef_count;
111 if (c == 0)
112 return true;
113 defined = (boolean *) malloc (c * sizeof (boolean));
114 included = (boolean *) malloc (c * sizeof (boolean));
115 if (defined == (boolean *) NULL || included == (boolean *) NULL)
116 {
117 bfd_set_error (bfd_error_no_memory);
118 goto error_return;
119 }
120 memset (defined, 0, c * sizeof (boolean));
121 memset (included, 0, c * sizeof (boolean));
122
123 symdefs = bfd_ardata (abfd)->symdefs;
124
125 do
126 {
127 file_ptr last;
128 symindex i;
129 carsym *symdef;
130 carsym *symdefend;
131
132 loop = false;
133 last = -1;
134
135 symdef = symdefs;
136 symdefend = symdef + c;
137 for (i = 0; symdef < symdefend; symdef++, i++)
138 {
139 struct elf_link_hash_entry *h;
140 bfd *element;
141 struct bfd_link_hash_entry *undefs_tail;
142 symindex mark;
143
144 if (defined[i] || included[i])
145 continue;
146 if (symdef->file_offset == last)
147 {
148 included[i] = true;
149 continue;
150 }
151
152 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
153 false, false, false);
154 if (h == (struct elf_link_hash_entry *) NULL)
155 continue;
156 if (h->root.type != bfd_link_hash_undefined)
157 {
158 if (h->root.type != bfd_link_hash_undefweak)
159 defined[i] = true;
160 continue;
161 }
162
163 /* We need to include this archive member. */
164
165 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
166 if (element == (bfd *) NULL)
167 goto error_return;
168
169 if (! bfd_check_format (element, bfd_object))
170 goto error_return;
171
172 /* Doublecheck that we have not included this object
173 already--it should be impossible, but there may be
174 something wrong with the archive. */
175 if (element->archive_pass != 0)
176 {
177 bfd_set_error (bfd_error_bad_value);
178 goto error_return;
179 }
180 element->archive_pass = 1;
181
182 undefs_tail = info->hash->undefs_tail;
183
184 if (! (*info->callbacks->add_archive_element) (info, element,
185 symdef->name))
186 goto error_return;
187 if (! elf_link_add_object_symbols (element, info))
188 goto error_return;
189
190 /* If there are any new undefined symbols, we need to make
191 another pass through the archive in order to see whether
192 they can be defined. FIXME: This isn't perfect, because
193 common symbols wind up on undefs_tail and because an
194 undefined symbol which is defined later on in this pass
195 does not require another pass. This isn't a bug, but it
196 does make the code less efficient than it could be. */
197 if (undefs_tail != info->hash->undefs_tail)
198 loop = true;
199
200 /* Look backward to mark all symbols from this object file
201 which we have already seen in this pass. */
202 mark = i;
203 do
204 {
205 included[mark] = true;
206 if (mark == 0)
207 break;
208 --mark;
209 }
210 while (symdefs[mark].file_offset == symdef->file_offset);
211
212 /* We mark subsequent symbols from this object file as we go
213 on through the loop. */
214 last = symdef->file_offset;
215 }
216 }
217 while (loop);
218
219 free (defined);
220 free (included);
221
222 return true;
223
224 error_return:
225 if (defined != (boolean *) NULL)
226 free (defined);
227 if (included != (boolean *) NULL)
228 free (included);
229 return false;
230 }
231
232 /* Add symbols from an ELF object file to the linker hash table. */
233
234 static boolean
235 elf_link_add_object_symbols (abfd, info)
236 bfd *abfd;
237 struct bfd_link_info *info;
238 {
239 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
240 const Elf_Internal_Sym *,
241 const char **, flagword *,
242 asection **, bfd_vma *));
243 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
244 asection *, const Elf_Internal_Rela *));
245 boolean collect;
246 Elf_Internal_Shdr *hdr;
247 size_t symcount;
248 size_t extsymcount;
249 size_t extsymoff;
250 Elf_External_Sym *buf = NULL;
251 struct elf_link_hash_entry **sym_hash;
252 boolean dynamic;
253 Elf_External_Dyn *dynbuf = NULL;
254 struct elf_link_hash_entry *weaks;
255 Elf_External_Sym *esym;
256 Elf_External_Sym *esymend;
257
258 add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
259 collect = get_elf_backend_data (abfd)->collect;
260
261 /* As a GNU extension, any input sections which are named
262 .gnu.warning.SYMBOL are treated as warning symbols for the given
263 symbol. This differs from .gnu.warning sections, which generate
264 warnings when they are included in an output file. */
265 if (! info->shared)
266 {
267 asection *s;
268
269 for (s = abfd->sections; s != NULL; s = s->next)
270 {
271 const char *name;
272
273 name = bfd_get_section_name (abfd, s);
274 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
275 {
276 char *msg;
277 bfd_size_type sz;
278
279 sz = bfd_section_size (abfd, s);
280 msg = (char *) bfd_alloc (abfd, sz);
281 if (msg == NULL)
282 {
283 bfd_set_error (bfd_error_no_memory);
284 goto error_return;
285 }
286
287 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
288 goto error_return;
289
290 if (! (_bfd_generic_link_add_one_symbol
291 (info, abfd,
292 name + sizeof ".gnu.warning." - 1,
293 BSF_WARNING, s, (bfd_vma) 0, msg, false, collect,
294 (struct bfd_link_hash_entry **) NULL)))
295 goto error_return;
296
297 if (! info->relocateable)
298 {
299 /* Clobber the section size so that the warning does
300 not get copied into the output file. */
301 s->_raw_size = 0;
302 }
303 }
304 }
305 }
306
307 /* A stripped shared library might only have a dynamic symbol table,
308 not a regular symbol table. In that case we can still go ahead
309 and link using the dynamic symbol table. */
310 if (elf_onesymtab (abfd) == 0
311 && elf_dynsymtab (abfd) != 0)
312 {
313 elf_onesymtab (abfd) = elf_dynsymtab (abfd);
314 elf_tdata (abfd)->symtab_hdr = elf_tdata (abfd)->dynsymtab_hdr;
315 }
316
317 hdr = &elf_tdata (abfd)->symtab_hdr;
318 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
319
320 /* The sh_info field of the symtab header tells us where the
321 external symbols start. We don't care about the local symbols at
322 this point. */
323 if (elf_bad_symtab (abfd))
324 {
325 extsymcount = symcount;
326 extsymoff = 0;
327 }
328 else
329 {
330 extsymcount = symcount - hdr->sh_info;
331 extsymoff = hdr->sh_info;
332 }
333
334 buf = (Elf_External_Sym *) malloc (extsymcount * sizeof (Elf_External_Sym));
335 if (buf == NULL && extsymcount != 0)
336 {
337 bfd_set_error (bfd_error_no_memory);
338 goto error_return;
339 }
340
341 /* We store a pointer to the hash table entry for each external
342 symbol. */
343 sym_hash = ((struct elf_link_hash_entry **)
344 bfd_alloc (abfd,
345 extsymcount * sizeof (struct elf_link_hash_entry *)));
346 if (sym_hash == NULL)
347 {
348 bfd_set_error (bfd_error_no_memory);
349 goto error_return;
350 }
351 elf_sym_hashes (abfd) = sym_hash;
352
353 if (elf_elfheader (abfd)->e_type != ET_DYN)
354 {
355 dynamic = false;
356
357 /* If we are creating a shared library, create all the dynamic
358 sections immediately. We need to attach them to something,
359 so we attach them to this BFD, provided it is the right
360 format. FIXME: If there are no input BFD's of the same
361 format as the output, we can't make a shared library. */
362 if (info->shared
363 && ! elf_hash_table (info)->dynamic_sections_created
364 && abfd->xvec == info->hash->creator)
365 {
366 if (! elf_link_create_dynamic_sections (abfd, info))
367 goto error_return;
368 }
369 }
370 else
371 {
372 asection *s;
373 boolean add_needed;
374 const char *name;
375 bfd_size_type oldsize;
376 bfd_size_type strindex;
377
378 dynamic = true;
379
380 /* You can't use -r against a dynamic object. Also, there's no
381 hope of using a dynamic object which does not exactly match
382 the format of the output file. */
383 if (info->relocateable
384 || info->hash->creator != abfd->xvec)
385 {
386 bfd_set_error (bfd_error_invalid_operation);
387 goto error_return;
388 }
389
390 /* Find the name to use in a DT_NEEDED entry that refers to this
391 object. If the object has a DT_SONAME entry, we use it.
392 Otherwise, if the generic linker stuck something in
393 elf_dt_needed_name, we use that. Otherwise, we just use the
394 file name. If the generic linker put a null string into
395 elf_dt_needed_name, we don't make a DT_NEEDED entry at all,
396 even if there is a DT_SONAME entry. */
397 add_needed = true;
398 name = bfd_get_filename (abfd);
399 if (elf_dt_needed_name (abfd) != NULL)
400 {
401 name = elf_dt_needed_name (abfd);
402 if (*name == '\0')
403 add_needed = false;
404 }
405 s = bfd_get_section_by_name (abfd, ".dynamic");
406 if (s != NULL)
407 {
408 Elf_External_Dyn *extdyn;
409 Elf_External_Dyn *extdynend;
410 int elfsec;
411 unsigned long link;
412
413 dynbuf = (Elf_External_Dyn *) malloc ((size_t) s->_raw_size);
414 if (dynbuf == NULL)
415 {
416 bfd_set_error (bfd_error_no_memory);
417 goto error_return;
418 }
419
420 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
421 (file_ptr) 0, s->_raw_size))
422 goto error_return;
423
424 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
425 if (elfsec == -1)
426 goto error_return;
427 link = elf_elfsections (abfd)[elfsec]->sh_link;
428
429 extdyn = dynbuf;
430 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
431 for (; extdyn < extdynend; extdyn++)
432 {
433 Elf_Internal_Dyn dyn;
434
435 elf_swap_dyn_in (abfd, extdyn, &dyn);
436 if (add_needed && dyn.d_tag == DT_SONAME)
437 {
438 name = bfd_elf_string_from_elf_section (abfd, link,
439 dyn.d_un.d_val);
440 if (name == NULL)
441 goto error_return;
442 }
443 if (dyn.d_tag == DT_NEEDED)
444 {
445 struct bfd_elf_link_needed_list *n, **pn;
446 char *fnm, *anm;
447
448 n = (struct bfd_elf_link_needed_list *)
449 bfd_alloc (abfd,
450 sizeof (struct bfd_elf_link_needed_list));
451 fnm = bfd_elf_string_from_elf_section (abfd, link,
452 dyn.d_un.d_val);
453 if (n == NULL || fnm == NULL)
454 goto error_return;
455 anm = bfd_alloc (abfd, strlen (fnm) + 1);
456 if (anm == NULL)
457 goto error_return;
458 strcpy (anm, fnm);
459 n->name = anm;
460 n->by = abfd;
461 n->next = NULL;
462 for (pn = &elf_hash_table (info)->needed;
463 *pn != NULL;
464 pn = &(*pn)->next)
465 ;
466 *pn = n;
467 }
468 }
469
470 free (dynbuf);
471 dynbuf = NULL;
472 }
473
474 /* We do not want to include any of the sections in a dynamic
475 object in the output file. We hack by simply clobbering the
476 list of sections in the BFD. This could be handled more
477 cleanly by, say, a new section flag; the existing
478 SEC_NEVER_LOAD flag is not the one we want, because that one
479 still implies that the section takes up space in the output
480 file. */
481 abfd->sections = NULL;
482
483 /* If this is the first dynamic object found in the link, create
484 the special sections required for dynamic linking. */
485 if (! elf_hash_table (info)->dynamic_sections_created)
486 {
487 if (! elf_link_create_dynamic_sections (abfd, info))
488 goto error_return;
489 }
490
491 if (add_needed)
492 {
493 /* Add a DT_NEEDED entry for this dynamic object. */
494 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
495 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
496 true, false);
497 if (strindex == (bfd_size_type) -1)
498 goto error_return;
499
500 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
501 {
502 asection *sdyn;
503 Elf_External_Dyn *dyncon, *dynconend;
504
505 /* The hash table size did not change, which means that
506 the dynamic object name was already entered. If we
507 have already included this dynamic object in the
508 link, just ignore it. There is no reason to include
509 a particular dynamic object more than once. */
510 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
511 ".dynamic");
512 BFD_ASSERT (sdyn != NULL);
513
514 dyncon = (Elf_External_Dyn *) sdyn->contents;
515 dynconend = (Elf_External_Dyn *) (sdyn->contents +
516 sdyn->_raw_size);
517 for (; dyncon < dynconend; dyncon++)
518 {
519 Elf_Internal_Dyn dyn;
520
521 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
522 &dyn);
523 if (dyn.d_tag == DT_NEEDED
524 && dyn.d_un.d_val == strindex)
525 {
526 if (buf != NULL)
527 free (buf);
528 return true;
529 }
530 }
531 }
532
533 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
534 goto error_return;
535 }
536 }
537
538 if (bfd_seek (abfd,
539 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
540 SEEK_SET) != 0
541 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
542 != extsymcount * sizeof (Elf_External_Sym)))
543 goto error_return;
544
545 weaks = NULL;
546
547 esymend = buf + extsymcount;
548 for (esym = buf; esym < esymend; esym++, sym_hash++)
549 {
550 Elf_Internal_Sym sym;
551 int bind;
552 bfd_vma value;
553 asection *sec;
554 flagword flags;
555 const char *name;
556 struct elf_link_hash_entry *h;
557 boolean definition;
558 boolean new_weakdef;
559
560 elf_swap_symbol_in (abfd, esym, &sym);
561
562 flags = BSF_NO_FLAGS;
563 sec = NULL;
564 value = sym.st_value;
565 *sym_hash = NULL;
566
567 bind = ELF_ST_BIND (sym.st_info);
568 if (bind == STB_LOCAL)
569 {
570 /* This should be impossible, since ELF requires that all
571 global symbols follow all local symbols, and that sh_info
572 point to the first global symbol. Unfortunatealy, Irix 5
573 screws this up. */
574 continue;
575 }
576 else if (bind == STB_GLOBAL)
577 {
578 if (sym.st_shndx != SHN_UNDEF
579 && sym.st_shndx != SHN_COMMON)
580 flags = BSF_GLOBAL;
581 else
582 flags = 0;
583 }
584 else if (bind == STB_WEAK)
585 flags = BSF_WEAK;
586 else
587 {
588 /* Leave it up to the processor backend. */
589 }
590
591 if (sym.st_shndx == SHN_UNDEF)
592 sec = bfd_und_section_ptr;
593 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
594 {
595 sec = section_from_elf_index (abfd, sym.st_shndx);
596 if (sec != NULL)
597 value -= sec->vma;
598 else
599 sec = bfd_abs_section_ptr;
600 }
601 else if (sym.st_shndx == SHN_ABS)
602 sec = bfd_abs_section_ptr;
603 else if (sym.st_shndx == SHN_COMMON)
604 {
605 sec = bfd_com_section_ptr;
606 /* What ELF calls the size we call the value. What ELF
607 calls the value we call the alignment. */
608 value = sym.st_size;
609 }
610 else
611 {
612 /* Leave it up to the processor backend. */
613 }
614
615 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
616 if (name == (const char *) NULL)
617 goto error_return;
618
619 if (add_symbol_hook)
620 {
621 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
622 &value))
623 goto error_return;
624
625 /* The hook function sets the name to NULL if this symbol
626 should be skipped for some reason. */
627 if (name == (const char *) NULL)
628 continue;
629 }
630
631 /* Sanity check that all possibilities were handled. */
632 if (sec == (asection *) NULL)
633 {
634 bfd_set_error (bfd_error_bad_value);
635 goto error_return;
636 }
637
638 if (bfd_is_und_section (sec)
639 || bfd_is_com_section (sec))
640 definition = false;
641 else
642 definition = true;
643
644 if (info->hash->creator->flavour == bfd_target_elf_flavour)
645 {
646 /* We need to look up the symbol now in order to get some of
647 the dynamic object handling right. We pass the hash
648 table entry in to _bfd_generic_link_add_one_symbol so
649 that it does not have to look it up again. */
650 h = elf_link_hash_lookup (elf_hash_table (info), name,
651 true, false, false);
652 if (h == NULL)
653 goto error_return;
654 *sym_hash = h;
655
656 while (h->root.type == bfd_link_hash_indirect
657 || h->root.type == bfd_link_hash_warning)
658 h = (struct elf_link_hash_entry *) h->root.u.i.link;
659
660 /* If we are looking at a dynamic object, and this is a
661 definition, we need to see if it has already been defined
662 by some other object. If it has, we want to use the
663 existing definition, and we do not want to report a
664 multiple symbol definition error; we do this by
665 clobbering sec to be bfd_und_section_ptr. */
666 if (dynamic && definition)
667 {
668 if (h->root.type == bfd_link_hash_defined
669 || h->root.type == bfd_link_hash_defweak
670 || (h->root.type == bfd_link_hash_common
671 && bind == STB_WEAK))
672 {
673 sec = bfd_und_section_ptr;
674 definition = false;
675 }
676 }
677
678 /* Similarly, if we are not looking at a dynamic object, and
679 we have a definition, we want to override any definition
680 we may have from a dynamic object. Symbols from regular
681 files always take precedence over symbols from dynamic
682 objects, even if they are defined after the dynamic
683 object in the link. */
684 if (! dynamic
685 && definition
686 && (h->root.type == bfd_link_hash_defined
687 || h->root.type == bfd_link_hash_defweak)
688 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
689 && (bfd_get_flavour (h->root.u.def.section->owner)
690 == bfd_target_elf_flavour)
691 && (elf_elfheader (h->root.u.def.section->owner)->e_type
692 == ET_DYN))
693 {
694 /* Change the hash table entry to undefined, and let
695 _bfd_generic_link_add_one_symbol do the right thing
696 with the new definition. */
697 h->root.type = bfd_link_hash_undefined;
698 h->root.u.undef.abfd = h->root.u.def.section->owner;
699 }
700 }
701
702 if (! (_bfd_generic_link_add_one_symbol
703 (info, abfd, name, flags, sec, value, (const char *) NULL,
704 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
705 goto error_return;
706
707 h = *sym_hash;
708 while (h->root.type == bfd_link_hash_indirect
709 || h->root.type == bfd_link_hash_warning)
710 h = (struct elf_link_hash_entry *) h->root.u.i.link;
711 *sym_hash = h;
712
713 new_weakdef = false;
714 if (dynamic
715 && definition
716 && (flags & BSF_WEAK) != 0
717 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
718 && info->hash->creator->flavour == bfd_target_elf_flavour
719 && h->weakdef == NULL)
720 {
721 /* Keep a list of all weak defined non function symbols from
722 a dynamic object, using the weakdef field. Later in this
723 function we will set the weakdef field to the correct
724 value. We only put non-function symbols from dynamic
725 objects on this list, because that happens to be the only
726 time we need to know the normal symbol corresponding to a
727 weak symbol, and the information is time consuming to
728 figure out. If the weakdef field is not already NULL,
729 then this symbol was already defined by some previous
730 dynamic object, and we will be using that previous
731 definition anyhow. */
732
733 h->weakdef = weaks;
734 weaks = h;
735 new_weakdef = true;
736 }
737
738 /* Get the alignment of a common symbol. */
739 if (sym.st_shndx == SHN_COMMON
740 && h->root.type == bfd_link_hash_common)
741 h->root.u.c.p->alignment_power = bfd_log2 (sym.st_value);
742
743 if (info->hash->creator->flavour == bfd_target_elf_flavour)
744 {
745 int old_flags;
746 boolean dynsym;
747 int new_flag;
748
749 /* Remember the symbol size and type. */
750 if (sym.st_size != 0
751 && (definition || h->size == 0))
752 {
753 if (h->size != 0 && h->size != sym.st_size)
754 (*_bfd_error_handler)
755 ("Warning: size of symbol `%s' changed from %lu to %lu in %s",
756 name, (unsigned long) h->size, (unsigned long) sym.st_size,
757 bfd_get_filename (abfd));
758
759 h->size = sym.st_size;
760 }
761 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
762 && (definition || h->type == STT_NOTYPE))
763 {
764 if (h->type != STT_NOTYPE
765 && h->type != ELF_ST_TYPE (sym.st_info))
766 (*_bfd_error_handler)
767 ("Warning: type of symbol `%s' changed from %d to %d in %s",
768 name, h->type, ELF_ST_TYPE (sym.st_info),
769 bfd_get_filename (abfd));
770
771 h->type = ELF_ST_TYPE (sym.st_info);
772 }
773
774 /* Set a flag in the hash table entry indicating the type of
775 reference or definition we just found. Keep a count of
776 the number of dynamic symbols we find. A dynamic symbol
777 is one which is referenced or defined by both a regular
778 object and a shared object, or one which is referenced or
779 defined by more than one shared object. */
780 old_flags = h->elf_link_hash_flags;
781 dynsym = false;
782 if (! dynamic)
783 {
784 if (! definition)
785 new_flag = ELF_LINK_HASH_REF_REGULAR;
786 else
787 new_flag = ELF_LINK_HASH_DEF_REGULAR;
788 if (info->shared
789 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
790 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
791 dynsym = true;
792 }
793 else
794 {
795 if (! definition)
796 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
797 else
798 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
799 if ((old_flags & new_flag) != 0
800 || (old_flags & (ELF_LINK_HASH_DEF_REGULAR
801 | ELF_LINK_HASH_REF_REGULAR)) != 0
802 || (h->weakdef != NULL
803 && (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
804 | ELF_LINK_HASH_REF_DYNAMIC)) != 0))
805 dynsym = true;
806 }
807
808 h->elf_link_hash_flags |= new_flag;
809 if (dynsym && h->dynindx == -1)
810 {
811 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
812 goto error_return;
813 if (h->weakdef != NULL
814 && ! new_weakdef
815 && h->weakdef->dynindx == -1)
816 {
817 if (! _bfd_elf_link_record_dynamic_symbol (info,
818 h->weakdef))
819 goto error_return;
820 }
821 }
822 }
823 }
824
825 /* Now set the weakdefs field correctly for all the weak defined
826 symbols we found. The only way to do this is to search all the
827 symbols. Since we only need the information for non functions in
828 dynamic objects, that's the only time we actually put anything on
829 the list WEAKS. We need this information so that if a regular
830 object refers to a symbol defined weakly in a dynamic object, the
831 real symbol in the dynamic object is also put in the dynamic
832 symbols; we also must arrange for both symbols to point to the
833 same memory location. We could handle the general case of symbol
834 aliasing, but a general symbol alias can only be generated in
835 assembler code, handling it correctly would be very time
836 consuming, and other ELF linkers don't handle general aliasing
837 either. */
838 while (weaks != NULL)
839 {
840 struct elf_link_hash_entry *hlook;
841 asection *slook;
842 bfd_vma vlook;
843 struct elf_link_hash_entry **hpp;
844 struct elf_link_hash_entry **hppend;
845
846 hlook = weaks;
847 weaks = hlook->weakdef;
848 hlook->weakdef = NULL;
849
850 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
851 || hlook->root.type == bfd_link_hash_defweak
852 || hlook->root.type == bfd_link_hash_common
853 || hlook->root.type == bfd_link_hash_indirect);
854 slook = hlook->root.u.def.section;
855 vlook = hlook->root.u.def.value;
856
857 hpp = elf_sym_hashes (abfd);
858 hppend = hpp + extsymcount;
859 for (; hpp < hppend; hpp++)
860 {
861 struct elf_link_hash_entry *h;
862
863 h = *hpp;
864 if (h != NULL && h != hlook
865 && (h->root.type == bfd_link_hash_defined
866 || h->root.type == bfd_link_hash_defweak)
867 && h->root.u.def.section == slook
868 && h->root.u.def.value == vlook)
869 {
870 hlook->weakdef = h;
871
872 /* If the weak definition is in the list of dynamic
873 symbols, make sure the real definition is put there
874 as well. */
875 if (hlook->dynindx != -1
876 && h->dynindx == -1)
877 {
878 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
879 goto error_return;
880 }
881
882 break;
883 }
884 }
885 }
886
887 if (buf != NULL)
888 {
889 free (buf);
890 buf = NULL;
891 }
892
893 /* If this object is the same format as the output object, and it is
894 not a shared library, then let the backend look through the
895 relocs.
896
897 This is required to build global offset table entries and to
898 arrange for dynamic relocs. It is not required for the
899 particular common case of linking non PIC code, even when linking
900 against shared libraries, but unfortunately there is no way of
901 knowing whether an object file has been compiled PIC or not.
902 Looking through the relocs is not particularly time consuming.
903 The problem is that we must either (1) keep the relocs in memory,
904 which causes the linker to require additional runtime memory or
905 (2) read the relocs twice from the input file, which wastes time.
906 This would be a good case for using mmap.
907
908 I have no idea how to handle linking PIC code into a file of a
909 different format. It probably can't be done. */
910 check_relocs = get_elf_backend_data (abfd)->check_relocs;
911 if (! dynamic
912 && abfd->xvec == info->hash->creator
913 && check_relocs != NULL)
914 {
915 asection *o;
916
917 for (o = abfd->sections; o != NULL; o = o->next)
918 {
919 Elf_Internal_Rela *internal_relocs;
920 boolean ok;
921
922 if ((o->flags & SEC_RELOC) == 0
923 || o->reloc_count == 0)
924 continue;
925
926 /* I believe we can ignore the relocs for any section which
927 does not form part of the final process image, such as a
928 debugging section. */
929 if ((o->flags & SEC_ALLOC) == 0)
930 continue;
931
932 internal_relocs = elf_link_read_relocs (abfd, o, (PTR) NULL,
933 (Elf_Internal_Rela *) NULL,
934 info->keep_memory);
935 if (internal_relocs == NULL)
936 goto error_return;
937
938 ok = (*check_relocs) (abfd, info, o, internal_relocs);
939
940 if (! info->keep_memory)
941 free (internal_relocs);
942
943 if (! ok)
944 goto error_return;
945 }
946 }
947
948 return true;
949
950 error_return:
951 if (buf != NULL)
952 free (buf);
953 if (dynbuf != NULL)
954 free (dynbuf);
955 return false;
956 }
957
958 /* Create some sections which will be filled in with dynamic linking
959 information. ABFD is an input file which requires dynamic sections
960 to be created. The dynamic sections take up virtual memory space
961 when the final executable is run, so we need to create them before
962 addresses are assigned to the output sections. We work out the
963 actual contents and size of these sections later. */
964
965 boolean
966 elf_link_create_dynamic_sections (abfd, info)
967 bfd *abfd;
968 struct bfd_link_info *info;
969 {
970 flagword flags;
971 register asection *s;
972 struct elf_link_hash_entry *h;
973 struct elf_backend_data *bed;
974
975 if (elf_hash_table (info)->dynamic_sections_created)
976 return true;
977
978 /* Make sure that all dynamic sections use the same input BFD. */
979 if (elf_hash_table (info)->dynobj == NULL)
980 elf_hash_table (info)->dynobj = abfd;
981 else
982 abfd = elf_hash_table (info)->dynobj;
983
984 /* Note that we set the SEC_IN_MEMORY flag for all of these
985 sections. */
986 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
987
988 /* A dynamically linked executable has a .interp section, but a
989 shared library does not. */
990 if (! info->shared)
991 {
992 s = bfd_make_section (abfd, ".interp");
993 if (s == NULL
994 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
995 return false;
996 }
997
998 s = bfd_make_section (abfd, ".dynsym");
999 if (s == NULL
1000 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1001 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1002 return false;
1003
1004 s = bfd_make_section (abfd, ".dynstr");
1005 if (s == NULL
1006 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
1007 return false;
1008
1009 /* Create a strtab to hold the dynamic symbol names. */
1010 if (elf_hash_table (info)->dynstr == NULL)
1011 {
1012 elf_hash_table (info)->dynstr = elf_stringtab_init ();
1013 if (elf_hash_table (info)->dynstr == NULL)
1014 return false;
1015 }
1016
1017 s = bfd_make_section (abfd, ".dynamic");
1018 if (s == NULL
1019 || ! bfd_set_section_flags (abfd, s, flags)
1020 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1021 return false;
1022
1023 /* The special symbol _DYNAMIC is always set to the start of the
1024 .dynamic section. This call occurs before we have processed the
1025 symbols for any dynamic object, so we don't have to worry about
1026 overriding a dynamic definition. We could set _DYNAMIC in a
1027 linker script, but we only want to define it if we are, in fact,
1028 creating a .dynamic section. We don't want to define it if there
1029 is no .dynamic section, since on some ELF platforms the start up
1030 code examines it to decide how to initialize the process. */
1031 h = NULL;
1032 if (! (_bfd_generic_link_add_one_symbol
1033 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
1034 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
1035 (struct bfd_link_hash_entry **) &h)))
1036 return false;
1037 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1038 h->type = STT_OBJECT;
1039
1040 if (info->shared
1041 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
1042 return false;
1043
1044 s = bfd_make_section (abfd, ".hash");
1045 if (s == NULL
1046 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1047 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1048 return false;
1049
1050 /* Let the backend create the rest of the sections. This lets the
1051 backend set the right flags. The backend will normally create
1052 the .got and .plt sections. */
1053 bed = get_elf_backend_data (abfd);
1054 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
1055 return false;
1056
1057 elf_hash_table (info)->dynamic_sections_created = true;
1058
1059 return true;
1060 }
1061
1062 /* Add an entry to the .dynamic table. */
1063
1064 boolean
1065 elf_add_dynamic_entry (info, tag, val)
1066 struct bfd_link_info *info;
1067 bfd_vma tag;
1068 bfd_vma val;
1069 {
1070 Elf_Internal_Dyn dyn;
1071 bfd *dynobj;
1072 asection *s;
1073 size_t newsize;
1074 bfd_byte *newcontents;
1075
1076 dynobj = elf_hash_table (info)->dynobj;
1077
1078 s = bfd_get_section_by_name (dynobj, ".dynamic");
1079 BFD_ASSERT (s != NULL);
1080
1081 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
1082 if (s->contents == NULL)
1083 newcontents = (bfd_byte *) malloc (newsize);
1084 else
1085 newcontents = (bfd_byte *) realloc (s->contents, newsize);
1086 if (newcontents == NULL)
1087 {
1088 bfd_set_error (bfd_error_no_memory);
1089 return false;
1090 }
1091
1092 dyn.d_tag = tag;
1093 dyn.d_un.d_val = val;
1094 elf_swap_dyn_out (dynobj, &dyn,
1095 (Elf_External_Dyn *) (newcontents + s->_raw_size));
1096
1097 s->_raw_size = newsize;
1098 s->contents = newcontents;
1099
1100 return true;
1101 }
1102
1103 /* Read and swap the relocs for a section. They may have been cached.
1104 If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL,
1105 they are used as buffers to read into. They are known to be large
1106 enough. If the INTERNAL_RELOCS relocs argument is NULL, the return
1107 value is allocated using either malloc or bfd_alloc, according to
1108 the KEEP_MEMORY argument. */
1109
1110 static Elf_Internal_Rela *
1111 elf_link_read_relocs (abfd, o, external_relocs, internal_relocs, keep_memory)
1112 bfd *abfd;
1113 asection *o;
1114 PTR external_relocs;
1115 Elf_Internal_Rela *internal_relocs;
1116 boolean keep_memory;
1117 {
1118 Elf_Internal_Shdr *rel_hdr;
1119 PTR alloc1 = NULL;
1120 Elf_Internal_Rela *alloc2 = NULL;
1121
1122 if (elf_section_data (o)->relocs != NULL)
1123 return elf_section_data (o)->relocs;
1124
1125 if (o->reloc_count == 0)
1126 return NULL;
1127
1128 rel_hdr = &elf_section_data (o)->rel_hdr;
1129
1130 if (internal_relocs == NULL)
1131 {
1132 size_t size;
1133
1134 size = o->reloc_count * sizeof (Elf_Internal_Rela);
1135 if (keep_memory)
1136 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
1137 else
1138 internal_relocs = alloc2 = (Elf_Internal_Rela *) malloc (size);
1139 if (internal_relocs == NULL)
1140 {
1141 bfd_set_error (bfd_error_no_memory);
1142 goto error_return;
1143 }
1144 }
1145
1146 if (external_relocs == NULL)
1147 {
1148 alloc1 = (PTR) malloc ((size_t) rel_hdr->sh_size);
1149 if (alloc1 == NULL)
1150 {
1151 bfd_set_error (bfd_error_no_memory);
1152 goto error_return;
1153 }
1154 external_relocs = alloc1;
1155 }
1156
1157 if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
1158 || (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd)
1159 != rel_hdr->sh_size))
1160 goto error_return;
1161
1162 /* Swap in the relocs. For convenience, we always produce an
1163 Elf_Internal_Rela array; if the relocs are Rel, we set the addend
1164 to 0. */
1165 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
1166 {
1167 Elf_External_Rel *erel;
1168 Elf_External_Rel *erelend;
1169 Elf_Internal_Rela *irela;
1170
1171 erel = (Elf_External_Rel *) external_relocs;
1172 erelend = erel + o->reloc_count;
1173 irela = internal_relocs;
1174 for (; erel < erelend; erel++, irela++)
1175 {
1176 Elf_Internal_Rel irel;
1177
1178 elf_swap_reloc_in (abfd, erel, &irel);
1179 irela->r_offset = irel.r_offset;
1180 irela->r_info = irel.r_info;
1181 irela->r_addend = 0;
1182 }
1183 }
1184 else
1185 {
1186 Elf_External_Rela *erela;
1187 Elf_External_Rela *erelaend;
1188 Elf_Internal_Rela *irela;
1189
1190 BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela));
1191
1192 erela = (Elf_External_Rela *) external_relocs;
1193 erelaend = erela + o->reloc_count;
1194 irela = internal_relocs;
1195 for (; erela < erelaend; erela++, irela++)
1196 elf_swap_reloca_in (abfd, erela, irela);
1197 }
1198
1199 /* Cache the results for next time, if we can. */
1200 if (keep_memory)
1201 elf_section_data (o)->relocs = internal_relocs;
1202
1203 if (alloc1 != NULL)
1204 free (alloc1);
1205
1206 /* Don't free alloc2, since if it was allocated we are passing it
1207 back (under the name of internal_relocs). */
1208
1209 return internal_relocs;
1210
1211 error_return:
1212 if (alloc1 != NULL)
1213 free (alloc1);
1214 if (alloc2 != NULL)
1215 free (alloc2);
1216 return NULL;
1217 }
1218
1219 /* Record an assignment to a symbol made by a linker script. We need
1220 this in case some dynamic object refers to this symbol. */
1221
1222 /*ARGSUSED*/
1223 boolean
1224 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
1225 bfd *output_bfd;
1226 struct bfd_link_info *info;
1227 const char *name;
1228 boolean provide;
1229 {
1230 struct elf_link_hash_entry *h;
1231
1232 if (info->hash->creator->flavour != bfd_target_elf_flavour)
1233 return true;
1234
1235 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
1236 if (h == NULL)
1237 return false;
1238
1239 /* If this symbol is being provided by the linker script, and it is
1240 currently defined by a dynamic object, but not by a regular
1241 object, then mark it as undefined so that the generic linker will
1242 force the correct value. */
1243 if (provide
1244 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
1245 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1246 h->root.type = bfd_link_hash_undefined;
1247
1248 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1249 h->type = STT_OBJECT;
1250
1251 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1252 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
1253 || info->shared)
1254 && h->dynindx == -1)
1255 {
1256 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1257 return false;
1258
1259 /* If this is a weak defined symbol, and we know a corresponding
1260 real symbol from the same dynamic object, make sure the real
1261 symbol is also made into a dynamic symbol. */
1262 if (h->weakdef != NULL
1263 && h->weakdef->dynindx == -1)
1264 {
1265 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
1266 return false;
1267 }
1268 }
1269
1270 return true;
1271 }
1272
1273 /* Array used to determine the number of hash table buckets to use
1274 based on the number of symbols there are. If there are fewer than
1275 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
1276 fewer than 37 we use 17 buckets, and so forth. We never use more
1277 than 521 buckets. */
1278
1279 static const size_t elf_buckets[] =
1280 {
1281 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 0
1282 };
1283
1284 /* Set up the sizes and contents of the ELF dynamic sections. This is
1285 called by the ELF linker emulation before_allocation routine. We
1286 must set the sizes of the sections before the linker sets the
1287 addresses of the various sections. */
1288
1289 boolean
1290 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
1291 export_dynamic, info, sinterpptr)
1292 bfd *output_bfd;
1293 const char *soname;
1294 const char *rpath;
1295 boolean export_dynamic;
1296 struct bfd_link_info *info;
1297 asection **sinterpptr;
1298 {
1299 bfd *dynobj;
1300 struct elf_backend_data *bed;
1301
1302 *sinterpptr = NULL;
1303
1304 if (info->hash->creator->flavour != bfd_target_elf_flavour)
1305 return true;
1306
1307 dynobj = elf_hash_table (info)->dynobj;
1308
1309 /* If there were no dynamic objects in the link, there is nothing to
1310 do here. */
1311 if (dynobj == NULL)
1312 return true;
1313
1314 /* If we are supposed to export all symbols into the dynamic symbol
1315 table (this is not the normal case), then do so. */
1316 if (export_dynamic)
1317 {
1318 struct elf_info_failed eif;
1319
1320 eif.failed = false;
1321 eif.info = info;
1322 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
1323 (PTR) &eif);
1324 if (eif.failed)
1325 return false;
1326 }
1327
1328 if (elf_hash_table (info)->dynamic_sections_created)
1329 {
1330 struct elf_info_failed eif;
1331 bfd_size_type strsize;
1332
1333 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
1334 BFD_ASSERT (*sinterpptr != NULL || info->shared);
1335
1336 if (soname != NULL)
1337 {
1338 bfd_size_type indx;
1339
1340 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, soname,
1341 true, true);
1342 if (indx == (bfd_size_type) -1
1343 || ! elf_add_dynamic_entry (info, DT_SONAME, indx))
1344 return false;
1345 }
1346
1347 if (info->symbolic)
1348 {
1349 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
1350 return false;
1351 }
1352
1353 if (rpath != NULL)
1354 {
1355 bfd_size_type indx;
1356
1357 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
1358 true, true);
1359 if (indx == (bfd_size_type) -1
1360 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
1361 return false;
1362 }
1363
1364 /* Find all symbols which were defined in a dynamic object and make
1365 the backend pick a reasonable value for them. */
1366 eif.failed = false;
1367 eif.info = info;
1368 elf_link_hash_traverse (elf_hash_table (info),
1369 elf_adjust_dynamic_symbol,
1370 (PTR) &eif);
1371 if (eif.failed)
1372 return false;
1373
1374 /* Add some entries to the .dynamic section. We fill in some of the
1375 values later, in elf_bfd_final_link, but we must add the entries
1376 now so that we know the final size of the .dynamic section. */
1377 if (elf_link_hash_lookup (elf_hash_table (info), "_init", false,
1378 false, false) != NULL)
1379 {
1380 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
1381 return false;
1382 }
1383 if (elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
1384 false, false) != NULL)
1385 {
1386 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
1387 return false;
1388 }
1389 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1390 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
1391 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
1392 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
1393 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
1394 || ! elf_add_dynamic_entry (info, DT_SYMENT,
1395 sizeof (Elf_External_Sym)))
1396 return false;
1397 }
1398
1399 /* The backend must work out the sizes of all the other dynamic
1400 sections. */
1401 bed = get_elf_backend_data (output_bfd);
1402 if (! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
1403 return false;
1404
1405 if (elf_hash_table (info)->dynamic_sections_created)
1406 {
1407 size_t dynsymcount;
1408 asection *s;
1409 size_t i;
1410 size_t bucketcount = 0;
1411 Elf_Internal_Sym isym;
1412
1413 /* Set the size of the .dynsym and .hash sections. We counted
1414 the number of dynamic symbols in elf_link_add_object_symbols.
1415 We will build the contents of .dynsym and .hash when we build
1416 the final symbol table, because until then we do not know the
1417 correct value to give the symbols. We built the .dynstr
1418 section as we went along in elf_link_add_object_symbols. */
1419 dynsymcount = elf_hash_table (info)->dynsymcount;
1420 s = bfd_get_section_by_name (dynobj, ".dynsym");
1421 BFD_ASSERT (s != NULL);
1422 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
1423 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
1424 if (s->contents == NULL && s->_raw_size != 0)
1425 {
1426 bfd_set_error (bfd_error_no_memory);
1427 return false;
1428 }
1429
1430 /* The first entry in .dynsym is a dummy symbol. */
1431 isym.st_value = 0;
1432 isym.st_size = 0;
1433 isym.st_name = 0;
1434 isym.st_info = 0;
1435 isym.st_other = 0;
1436 isym.st_shndx = 0;
1437 elf_swap_symbol_out (output_bfd, &isym,
1438 (PTR) (Elf_External_Sym *) s->contents);
1439
1440 for (i = 0; elf_buckets[i] != 0; i++)
1441 {
1442 bucketcount = elf_buckets[i];
1443 if (dynsymcount < elf_buckets[i + 1])
1444 break;
1445 }
1446
1447 s = bfd_get_section_by_name (dynobj, ".hash");
1448 BFD_ASSERT (s != NULL);
1449 s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
1450 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
1451 if (s->contents == NULL)
1452 {
1453 bfd_set_error (bfd_error_no_memory);
1454 return false;
1455 }
1456 memset (s->contents, 0, (size_t) s->_raw_size);
1457
1458 put_word (output_bfd, bucketcount, s->contents);
1459 put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
1460
1461 elf_hash_table (info)->bucketcount = bucketcount;
1462
1463 s = bfd_get_section_by_name (dynobj, ".dynstr");
1464 BFD_ASSERT (s != NULL);
1465 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1466
1467 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
1468 return false;
1469 }
1470
1471 return true;
1472 }
1473
1474 /* This routine is used to export all defined symbols into the dynamic
1475 symbol table. It is called via elf_link_hash_traverse. */
1476
1477 static boolean
1478 elf_export_symbol (h, data)
1479 struct elf_link_hash_entry *h;
1480 PTR data;
1481 {
1482 struct elf_info_failed *eif = (struct elf_info_failed *) data;
1483
1484 if (h->dynindx == -1
1485 && (h->elf_link_hash_flags
1486 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
1487 {
1488 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
1489 {
1490 eif->failed = true;
1491 return false;
1492 }
1493 }
1494
1495 return true;
1496 }
1497
1498 /* Make the backend pick a good value for a dynamic symbol. This is
1499 called via elf_link_hash_traverse, and also calls itself
1500 recursively. */
1501
1502 static boolean
1503 elf_adjust_dynamic_symbol (h, data)
1504 struct elf_link_hash_entry *h;
1505 PTR data;
1506 {
1507 struct elf_info_failed *eif = (struct elf_info_failed *) data;
1508 bfd *dynobj;
1509 struct elf_backend_data *bed;
1510
1511 /* If -Bsymbolic was used (which means to bind references to global
1512 symbols to the definition within the shared object), and this
1513 symbol was defined in a regular object, then it actually doesn't
1514 need a PLT entry. */
1515 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
1516 && eif->info->shared
1517 && eif->info->symbolic
1518 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
1519 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
1520
1521 /* If this symbol does not require a PLT entry, and it is not
1522 defined by a dynamic object, or is not referenced by a regular
1523 object, ignore it. We do have to handle a weak defined symbol,
1524 even if no regular object refers to it, if we decided to add it
1525 to the dynamic symbol table. FIXME: Do we normally need to worry
1526 about symbols which are defined by one dynamic object and
1527 referenced by another one? */
1528 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
1529 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
1530 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
1531 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
1532 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
1533 return true;
1534
1535 /* If we've already adjusted this symbol, don't do it again. This
1536 can happen via a recursive call. */
1537 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
1538 return true;
1539
1540 /* Don't look at this symbol again. Note that we must set this
1541 after checking the above conditions, because we may look at a
1542 symbol once, decide not to do anything, and then get called
1543 recursively later after REF_REGULAR is set below. */
1544 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
1545
1546 /* If this is a weak definition, and we know a real definition, and
1547 the real symbol is not itself defined by a regular object file,
1548 then get a good value for the real definition. We handle the
1549 real symbol first, for the convenience of the backend routine.
1550
1551 Note that there is a confusing case here. If the real definition
1552 is defined by a regular object file, we don't get the real symbol
1553 from the dynamic object, but we do get the weak symbol. If the
1554 processor backend uses a COPY reloc, then if some routine in the
1555 dynamic object changes the real symbol, we will not see that
1556 change in the corresponding weak symbol. This is the way other
1557 ELF linkers work as well, and seems to be a result of the shared
1558 library model.
1559
1560 I will clarify this issue. Most SVR4 shared libraries define the
1561 variable _timezone and define timezone as a weak synonym. The
1562 tzset call changes _timezone. If you write
1563 extern int timezone;
1564 int _timezone = 5;
1565 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
1566 you might expect that, since timezone is a synonym for _timezone,
1567 the same number will print both times. However, if the processor
1568 backend uses a COPY reloc, then actually timezone will be copied
1569 into your process image, and, since you define _timezone
1570 yourself, _timezone will not. Thus timezone and _timezone will
1571 wind up at different memory locations. The tzset call will set
1572 _timezone, leaving timezone unchanged. */
1573
1574 if (h->weakdef != NULL)
1575 {
1576 struct elf_link_hash_entry *weakdef;
1577
1578 BFD_ASSERT (h->root.type == bfd_link_hash_defined
1579 || h->root.type == bfd_link_hash_defweak);
1580 weakdef = h->weakdef;
1581 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
1582 || weakdef->root.type == bfd_link_hash_defweak);
1583 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
1584 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
1585 {
1586 /* This symbol is defined by a regular object file, so we
1587 will not do anything special. Clear weakdef for the
1588 convenience of the processor backend. */
1589 h->weakdef = NULL;
1590 }
1591 else
1592 {
1593 /* There is an implicit reference by a regular object file
1594 via the weak symbol. */
1595 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
1596 if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif))
1597 return false;
1598 }
1599 }
1600
1601 dynobj = elf_hash_table (eif->info)->dynobj;
1602 bed = get_elf_backend_data (dynobj);
1603 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
1604 {
1605 eif->failed = true;
1606 return false;
1607 }
1608
1609 return true;
1610 }
1611 \f
1612 /* Final phase of ELF linker. */
1613
1614 /* A structure we use to avoid passing large numbers of arguments. */
1615
1616 struct elf_final_link_info
1617 {
1618 /* General link information. */
1619 struct bfd_link_info *info;
1620 /* Output BFD. */
1621 bfd *output_bfd;
1622 /* Symbol string table. */
1623 struct bfd_strtab_hash *symstrtab;
1624 /* .dynsym section. */
1625 asection *dynsym_sec;
1626 /* .hash section. */
1627 asection *hash_sec;
1628 /* Buffer large enough to hold contents of any section. */
1629 bfd_byte *contents;
1630 /* Buffer large enough to hold external relocs of any section. */
1631 PTR external_relocs;
1632 /* Buffer large enough to hold internal relocs of any section. */
1633 Elf_Internal_Rela *internal_relocs;
1634 /* Buffer large enough to hold external local symbols of any input
1635 BFD. */
1636 Elf_External_Sym *external_syms;
1637 /* Buffer large enough to hold internal local symbols of any input
1638 BFD. */
1639 Elf_Internal_Sym *internal_syms;
1640 /* Array large enough to hold a symbol index for each local symbol
1641 of any input BFD. */
1642 long *indices;
1643 /* Array large enough to hold a section pointer for each local
1644 symbol of any input BFD. */
1645 asection **sections;
1646 /* Buffer to hold swapped out symbols. */
1647 Elf_External_Sym *symbuf;
1648 /* Number of swapped out symbols in buffer. */
1649 size_t symbuf_count;
1650 /* Number of symbols which fit in symbuf. */
1651 size_t symbuf_size;
1652 };
1653
1654 static boolean elf_link_output_sym
1655 PARAMS ((struct elf_final_link_info *, const char *,
1656 Elf_Internal_Sym *, asection *));
1657 static boolean elf_link_flush_output_syms
1658 PARAMS ((struct elf_final_link_info *));
1659 static boolean elf_link_output_extsym
1660 PARAMS ((struct elf_link_hash_entry *, PTR));
1661 static boolean elf_link_input_bfd
1662 PARAMS ((struct elf_final_link_info *, bfd *));
1663 static boolean elf_reloc_link_order
1664 PARAMS ((bfd *, struct bfd_link_info *, asection *,
1665 struct bfd_link_order *));
1666
1667 /* This struct is used to pass information to routines called via
1668 elf_link_hash_traverse which must return failure. */
1669
1670 struct elf_finfo_failed
1671 {
1672 boolean failed;
1673 struct elf_final_link_info *finfo;
1674 };
1675
1676 /* Do the final step of an ELF link. */
1677
1678 boolean
1679 elf_bfd_final_link (abfd, info)
1680 bfd *abfd;
1681 struct bfd_link_info *info;
1682 {
1683 boolean dynamic;
1684 bfd *dynobj;
1685 struct elf_final_link_info finfo;
1686 register asection *o;
1687 register struct bfd_link_order *p;
1688 register bfd *sub;
1689 size_t max_contents_size;
1690 size_t max_external_reloc_size;
1691 size_t max_internal_reloc_count;
1692 size_t max_sym_count;
1693 file_ptr off;
1694 Elf_Internal_Sym elfsym;
1695 unsigned int i;
1696 Elf_Internal_Shdr *symtab_hdr;
1697 Elf_Internal_Shdr *symstrtab_hdr;
1698 struct elf_backend_data *bed = get_elf_backend_data (abfd);
1699 struct elf_finfo_failed eif;
1700
1701 if (info->shared)
1702 abfd->flags |= DYNAMIC;
1703
1704 dynamic = elf_hash_table (info)->dynamic_sections_created;
1705 dynobj = elf_hash_table (info)->dynobj;
1706
1707 finfo.info = info;
1708 finfo.output_bfd = abfd;
1709 finfo.symstrtab = elf_stringtab_init ();
1710 if (finfo.symstrtab == NULL)
1711 return false;
1712 if (! dynamic)
1713 {
1714 finfo.dynsym_sec = NULL;
1715 finfo.hash_sec = NULL;
1716 }
1717 else
1718 {
1719 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
1720 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
1721 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
1722 }
1723 finfo.contents = NULL;
1724 finfo.external_relocs = NULL;
1725 finfo.internal_relocs = NULL;
1726 finfo.external_syms = NULL;
1727 finfo.internal_syms = NULL;
1728 finfo.indices = NULL;
1729 finfo.sections = NULL;
1730 finfo.symbuf = NULL;
1731 finfo.symbuf_count = 0;
1732
1733 /* Count up the number of relocations we will output for each output
1734 section, so that we know the sizes of the reloc sections. We
1735 also figure out some maximum sizes. */
1736 max_contents_size = 0;
1737 max_external_reloc_size = 0;
1738 max_internal_reloc_count = 0;
1739 max_sym_count = 0;
1740 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
1741 {
1742 o->reloc_count = 0;
1743
1744 for (p = o->link_order_head; p != NULL; p = p->next)
1745 {
1746 if (p->type == bfd_section_reloc_link_order
1747 || p->type == bfd_symbol_reloc_link_order)
1748 ++o->reloc_count;
1749 else if (p->type == bfd_indirect_link_order)
1750 {
1751 asection *sec;
1752
1753 sec = p->u.indirect.section;
1754
1755 if (info->relocateable)
1756 o->reloc_count += sec->reloc_count;
1757
1758 if (sec->_raw_size > max_contents_size)
1759 max_contents_size = sec->_raw_size;
1760 if (sec->_cooked_size > max_contents_size)
1761 max_contents_size = sec->_cooked_size;
1762
1763 /* We are interested in just local symbols, not all
1764 symbols. */
1765 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour)
1766 {
1767 size_t sym_count;
1768
1769 if (elf_bad_symtab (sec->owner))
1770 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
1771 / sizeof (Elf_External_Sym));
1772 else
1773 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
1774
1775 if (sym_count > max_sym_count)
1776 max_sym_count = sym_count;
1777
1778 if ((sec->flags & SEC_RELOC) != 0)
1779 {
1780 size_t ext_size;
1781
1782 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
1783 if (ext_size > max_external_reloc_size)
1784 max_external_reloc_size = ext_size;
1785 if (sec->reloc_count > max_internal_reloc_count)
1786 max_internal_reloc_count = sec->reloc_count;
1787 }
1788 }
1789 }
1790 }
1791
1792 if (o->reloc_count > 0)
1793 o->flags |= SEC_RELOC;
1794 else
1795 {
1796 /* Explicitly clear the SEC_RELOC flag. The linker tends to
1797 set it (this is probably a bug) and if it is set
1798 assign_section_numbers will create a reloc section. */
1799 o->flags &=~ SEC_RELOC;
1800 }
1801
1802 /* If the SEC_ALLOC flag is not set, force the section VMA to
1803 zero. This is done in elf_fake_sections as well, but forcing
1804 the VMA to 0 here will ensure that relocs against these
1805 sections are handled correctly. */
1806 if ((o->flags & SEC_ALLOC) == 0)
1807 o->vma = 0;
1808 }
1809
1810 /* Figure out the file positions for everything but the symbol table
1811 and the relocs. We set symcount to force assign_section_numbers
1812 to create a symbol table. */
1813 abfd->symcount = info->strip == strip_all ? 0 : 1;
1814 BFD_ASSERT (! abfd->output_has_begun);
1815 if (! _bfd_elf_compute_section_file_positions (abfd, info))
1816 goto error_return;
1817
1818 /* That created the reloc sections. Set their sizes, and assign
1819 them file positions, and allocate some buffers. */
1820 for (o = abfd->sections; o != NULL; o = o->next)
1821 {
1822 if ((o->flags & SEC_RELOC) != 0)
1823 {
1824 Elf_Internal_Shdr *rel_hdr;
1825 register struct elf_link_hash_entry **p, **pend;
1826
1827 rel_hdr = &elf_section_data (o)->rel_hdr;
1828
1829 rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
1830
1831 /* The contents field must last into write_object_contents,
1832 so we allocate it with bfd_alloc rather than malloc. */
1833 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
1834 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
1835 {
1836 bfd_set_error (bfd_error_no_memory);
1837 goto error_return;
1838 }
1839
1840 p = ((struct elf_link_hash_entry **)
1841 malloc (o->reloc_count
1842 * sizeof (struct elf_link_hash_entry *)));
1843 if (p == NULL && o->reloc_count != 0)
1844 {
1845 bfd_set_error (bfd_error_no_memory);
1846 goto error_return;
1847 }
1848 elf_section_data (o)->rel_hashes = p;
1849 pend = p + o->reloc_count;
1850 for (; p < pend; p++)
1851 *p = NULL;
1852
1853 /* Use the reloc_count field as an index when outputting the
1854 relocs. */
1855 o->reloc_count = 0;
1856 }
1857 }
1858
1859 _bfd_elf_assign_file_positions_for_relocs (abfd);
1860
1861 /* We have now assigned file positions for all the sections except
1862 .symtab and .strtab. We start the .symtab section at the current
1863 file position, and write directly to it. We build the .strtab
1864 section in memory. When we add .dynsym support, we will build
1865 that in memory as well (.dynsym is smaller than .symtab). */
1866 abfd->symcount = 0;
1867 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1868 /* sh_name is set in prep_headers. */
1869 symtab_hdr->sh_type = SHT_SYMTAB;
1870 symtab_hdr->sh_flags = 0;
1871 symtab_hdr->sh_addr = 0;
1872 symtab_hdr->sh_size = 0;
1873 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
1874 /* sh_link is set in assign_section_numbers. */
1875 /* sh_info is set below. */
1876 /* sh_offset is set just below. */
1877 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
1878
1879 off = elf_tdata (abfd)->next_file_pos;
1880 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
1881
1882 /* Note that at this point elf_tdata (abfd)->next_file_pos is
1883 incorrect. We do not yet know the size of the .symtab section.
1884 We correct next_file_pos below, after we do know the size. */
1885
1886 /* Allocate a buffer to hold swapped out symbols. This is to avoid
1887 continuously seeking to the right position in the file. */
1888 if (! info->keep_memory || max_sym_count < 20)
1889 finfo.symbuf_size = 20;
1890 else
1891 finfo.symbuf_size = max_sym_count;
1892 finfo.symbuf = ((Elf_External_Sym *)
1893 malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
1894 if (finfo.symbuf == NULL)
1895 {
1896 bfd_set_error (bfd_error_no_memory);
1897 goto error_return;
1898 }
1899
1900 /* Start writing out the symbol table. The first symbol is always a
1901 dummy symbol. */
1902 elfsym.st_value = 0;
1903 elfsym.st_size = 0;
1904 elfsym.st_info = 0;
1905 elfsym.st_other = 0;
1906 elfsym.st_shndx = SHN_UNDEF;
1907 if (! elf_link_output_sym (&finfo, (const char *) NULL,
1908 &elfsym, bfd_und_section_ptr))
1909 goto error_return;
1910
1911 #if 0
1912 /* Some standard ELF linkers do this, but we don't because it causes
1913 bootstrap comparison failures. */
1914 /* Output a file symbol for the output file as the second symbol.
1915 We output this even if we are discarding local symbols, although
1916 I'm not sure if this is correct. */
1917 elfsym.st_value = 0;
1918 elfsym.st_size = 0;
1919 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
1920 elfsym.st_other = 0;
1921 elfsym.st_shndx = SHN_ABS;
1922 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
1923 &elfsym, bfd_abs_section_ptr))
1924 goto error_return;
1925 #endif
1926
1927 /* Output a symbol for each section. We output these even if we are
1928 discarding local symbols, since they are used for relocs. These
1929 symbols have no names. We store the index of each one in the
1930 index field of the section, so that we can find it again when
1931 outputting relocs. */
1932 elfsym.st_value = 0;
1933 elfsym.st_size = 0;
1934 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
1935 elfsym.st_other = 0;
1936 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
1937 {
1938 o = section_from_elf_index (abfd, i);
1939 if (o != NULL)
1940 o->target_index = abfd->symcount;
1941 elfsym.st_shndx = i;
1942 if (! elf_link_output_sym (&finfo, (const char *) NULL,
1943 &elfsym, o))
1944 goto error_return;
1945 }
1946
1947 /* Allocate some memory to hold information read in from the input
1948 files. */
1949 finfo.contents = (bfd_byte *) malloc (max_contents_size);
1950 finfo.external_relocs = (PTR) malloc (max_external_reloc_size);
1951 finfo.internal_relocs = ((Elf_Internal_Rela *)
1952 malloc (max_internal_reloc_count
1953 * sizeof (Elf_Internal_Rela)));
1954 finfo.external_syms = ((Elf_External_Sym *)
1955 malloc (max_sym_count * sizeof (Elf_External_Sym)));
1956 finfo.internal_syms = ((Elf_Internal_Sym *)
1957 malloc (max_sym_count * sizeof (Elf_Internal_Sym)));
1958 finfo.indices = (long *) malloc (max_sym_count * sizeof (long));
1959 finfo.sections = (asection **) malloc (max_sym_count * sizeof (asection *));
1960 if ((finfo.contents == NULL && max_contents_size != 0)
1961 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
1962 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
1963 || (finfo.external_syms == NULL && max_sym_count != 0)
1964 || (finfo.internal_syms == NULL && max_sym_count != 0)
1965 || (finfo.indices == NULL && max_sym_count != 0)
1966 || (finfo.sections == NULL && max_sym_count != 0))
1967 {
1968 bfd_set_error (bfd_error_no_memory);
1969 goto error_return;
1970 }
1971
1972 /* Since ELF permits relocations to be against local symbols, we
1973 must have the local symbols available when we do the relocations.
1974 Since we would rather only read the local symbols once, and we
1975 would rather not keep them in memory, we handle all the
1976 relocations for a single input file at the same time.
1977
1978 Unfortunately, there is no way to know the total number of local
1979 symbols until we have seen all of them, and the local symbol
1980 indices precede the global symbol indices. This means that when
1981 we are generating relocateable output, and we see a reloc against
1982 a global symbol, we can not know the symbol index until we have
1983 finished examining all the local symbols to see which ones we are
1984 going to output. To deal with this, we keep the relocations in
1985 memory, and don't output them until the end of the link. This is
1986 an unfortunate waste of memory, but I don't see a good way around
1987 it. Fortunately, it only happens when performing a relocateable
1988 link, which is not the common case. FIXME: If keep_memory is set
1989 we could write the relocs out and then read them again; I don't
1990 know how bad the memory loss will be. */
1991
1992 for (sub = info->input_bfds; sub != NULL; sub = sub->next)
1993 sub->output_has_begun = false;
1994 for (o = abfd->sections; o != NULL; o = o->next)
1995 {
1996 for (p = o->link_order_head; p != NULL; p = p->next)
1997 {
1998 if (p->type == bfd_indirect_link_order
1999 && (bfd_get_flavour (p->u.indirect.section->owner)
2000 == bfd_target_elf_flavour))
2001 {
2002 sub = p->u.indirect.section->owner;
2003 if (! sub->output_has_begun)
2004 {
2005 if (! elf_link_input_bfd (&finfo, sub))
2006 goto error_return;
2007 sub->output_has_begun = true;
2008 }
2009 }
2010 else if (p->type == bfd_section_reloc_link_order
2011 || p->type == bfd_symbol_reloc_link_order)
2012 {
2013 if (! elf_reloc_link_order (abfd, info, o, p))
2014 goto error_return;
2015 }
2016 else
2017 {
2018 if (! _bfd_default_link_order (abfd, info, o, p))
2019 goto error_return;
2020 }
2021 }
2022 }
2023
2024 /* That wrote out all the local symbols. Finish up the symbol table
2025 with the global symbols. */
2026
2027 /* The sh_info field records the index of the first non local
2028 symbol. */
2029 symtab_hdr->sh_info = abfd->symcount;
2030 if (dynamic)
2031 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1;
2032
2033 /* We get the global symbols from the hash table. */
2034 eif.failed = false;
2035 eif.finfo = &finfo;
2036 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
2037 (PTR) &eif);
2038 if (eif.failed)
2039 return false;
2040
2041 /* Flush all symbols to the file. */
2042 if (! elf_link_flush_output_syms (&finfo))
2043 return false;
2044
2045 /* Now we know the size of the symtab section. */
2046 off += symtab_hdr->sh_size;
2047
2048 /* Finish up and write out the symbol string table (.strtab)
2049 section. */
2050 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
2051 /* sh_name was set in prep_headers. */
2052 symstrtab_hdr->sh_type = SHT_STRTAB;
2053 symstrtab_hdr->sh_flags = 0;
2054 symstrtab_hdr->sh_addr = 0;
2055 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
2056 symstrtab_hdr->sh_entsize = 0;
2057 symstrtab_hdr->sh_link = 0;
2058 symstrtab_hdr->sh_info = 0;
2059 /* sh_offset is set just below. */
2060 symstrtab_hdr->sh_addralign = 1;
2061
2062 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
2063 elf_tdata (abfd)->next_file_pos = off;
2064
2065 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
2066 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
2067 return false;
2068
2069 /* Adjust the relocs to have the correct symbol indices. */
2070 for (o = abfd->sections; o != NULL; o = o->next)
2071 {
2072 struct elf_link_hash_entry **rel_hash;
2073 Elf_Internal_Shdr *rel_hdr;
2074
2075 if ((o->flags & SEC_RELOC) == 0)
2076 continue;
2077
2078 rel_hash = elf_section_data (o)->rel_hashes;
2079 rel_hdr = &elf_section_data (o)->rel_hdr;
2080 for (i = 0; i < o->reloc_count; i++, rel_hash++)
2081 {
2082 if (*rel_hash == NULL)
2083 continue;
2084
2085 BFD_ASSERT ((*rel_hash)->indx >= 0);
2086
2087 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
2088 {
2089 Elf_External_Rel *erel;
2090 Elf_Internal_Rel irel;
2091
2092 erel = (Elf_External_Rel *) rel_hdr->contents + i;
2093 elf_swap_reloc_in (abfd, erel, &irel);
2094 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
2095 ELF_R_TYPE (irel.r_info));
2096 elf_swap_reloc_out (abfd, &irel, erel);
2097 }
2098 else
2099 {
2100 Elf_External_Rela *erela;
2101 Elf_Internal_Rela irela;
2102
2103 BFD_ASSERT (rel_hdr->sh_entsize
2104 == sizeof (Elf_External_Rela));
2105
2106 erela = (Elf_External_Rela *) rel_hdr->contents + i;
2107 elf_swap_reloca_in (abfd, erela, &irela);
2108 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
2109 ELF_R_TYPE (irela.r_info));
2110 elf_swap_reloca_out (abfd, &irela, erela);
2111 }
2112 }
2113
2114 /* Set the reloc_count field to 0 to prevent write_relocs from
2115 trying to swap the relocs out itself. */
2116 o->reloc_count = 0;
2117 }
2118
2119 /* If we are linking against a dynamic object, or generating a
2120 shared library, finish up the dynamic linking information. */
2121 if (dynamic)
2122 {
2123 Elf_External_Dyn *dyncon, *dynconend;
2124
2125 /* Fix up .dynamic entries. */
2126 o = bfd_get_section_by_name (dynobj, ".dynamic");
2127 BFD_ASSERT (o != NULL);
2128
2129 dyncon = (Elf_External_Dyn *) o->contents;
2130 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
2131 for (; dyncon < dynconend; dyncon++)
2132 {
2133 Elf_Internal_Dyn dyn;
2134 const char *name;
2135 unsigned int type;
2136
2137 elf_swap_dyn_in (dynobj, dyncon, &dyn);
2138
2139 switch (dyn.d_tag)
2140 {
2141 default:
2142 break;
2143
2144 /* SVR4 linkers seem to set DT_INIT and DT_FINI based on
2145 magic _init and _fini symbols. This is pretty ugly,
2146 but we are compatible. */
2147 case DT_INIT:
2148 name = "_init";
2149 goto get_sym;
2150 case DT_FINI:
2151 name = "_fini";
2152 get_sym:
2153 {
2154 struct elf_link_hash_entry *h;
2155
2156 h = elf_link_hash_lookup (elf_hash_table (info), name,
2157 false, false, true);
2158 if (h != NULL
2159 && (h->root.type == bfd_link_hash_defined
2160 || h->root.type == bfd_link_hash_defweak))
2161 {
2162 dyn.d_un.d_val = h->root.u.def.value;
2163 o = h->root.u.def.section;
2164 if (o->output_section != NULL)
2165 dyn.d_un.d_val += (o->output_section->vma
2166 + o->output_offset);
2167 else
2168 {
2169 /* The symbol is imported from another shared
2170 library and does not apply to this one. */
2171 dyn.d_un.d_val = 0;
2172 }
2173
2174 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2175 }
2176 }
2177 break;
2178
2179 case DT_HASH:
2180 name = ".hash";
2181 goto get_vma;
2182 case DT_STRTAB:
2183 name = ".dynstr";
2184 goto get_vma;
2185 case DT_SYMTAB:
2186 name = ".dynsym";
2187 get_vma:
2188 o = bfd_get_section_by_name (abfd, name);
2189 BFD_ASSERT (o != NULL);
2190 dyn.d_un.d_ptr = o->vma;
2191 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2192 break;
2193
2194 case DT_REL:
2195 case DT_RELA:
2196 case DT_RELSZ:
2197 case DT_RELASZ:
2198 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
2199 type = SHT_REL;
2200 else
2201 type = SHT_RELA;
2202 dyn.d_un.d_val = 0;
2203 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
2204 {
2205 Elf_Internal_Shdr *hdr;
2206
2207 hdr = elf_elfsections (abfd)[i];
2208 if (hdr->sh_type == type
2209 && (hdr->sh_flags & SHF_ALLOC) != 0)
2210 {
2211 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
2212 dyn.d_un.d_val += hdr->sh_size;
2213 else
2214 {
2215 if (dyn.d_un.d_val == 0
2216 || hdr->sh_addr < dyn.d_un.d_val)
2217 dyn.d_un.d_val = hdr->sh_addr;
2218 }
2219 }
2220 }
2221 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2222 break;
2223 }
2224 }
2225 }
2226
2227 /* If we have created any dynamic sections, then output them. */
2228 if (dynobj != NULL)
2229 {
2230 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
2231 goto error_return;
2232
2233 for (o = dynobj->sections; o != NULL; o = o->next)
2234 {
2235 if ((o->flags & SEC_HAS_CONTENTS) == 0
2236 || o->_raw_size == 0)
2237 continue;
2238 if ((o->flags & SEC_IN_MEMORY) == 0)
2239 {
2240 /* At this point, we are only interested in sections
2241 created by elf_link_create_dynamic_sections. FIXME:
2242 This test is fragile. */
2243 continue;
2244 }
2245 if ((elf_section_data (o->output_section)->this_hdr.sh_type
2246 != SHT_STRTAB)
2247 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
2248 {
2249 if (! bfd_set_section_contents (abfd, o->output_section,
2250 o->contents, o->output_offset,
2251 o->_raw_size))
2252 goto error_return;
2253 }
2254 else
2255 {
2256 file_ptr off;
2257
2258 /* The contents of the .dynstr section are actually in a
2259 stringtab. */
2260 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
2261 if (bfd_seek (abfd, off, SEEK_SET) != 0
2262 || ! _bfd_stringtab_emit (abfd,
2263 elf_hash_table (info)->dynstr))
2264 goto error_return;
2265 }
2266 }
2267 }
2268
2269 if (finfo.symstrtab != NULL)
2270 _bfd_stringtab_free (finfo.symstrtab);
2271 if (finfo.contents != NULL)
2272 free (finfo.contents);
2273 if (finfo.external_relocs != NULL)
2274 free (finfo.external_relocs);
2275 if (finfo.internal_relocs != NULL)
2276 free (finfo.internal_relocs);
2277 if (finfo.external_syms != NULL)
2278 free (finfo.external_syms);
2279 if (finfo.internal_syms != NULL)
2280 free (finfo.internal_syms);
2281 if (finfo.indices != NULL)
2282 free (finfo.indices);
2283 if (finfo.sections != NULL)
2284 free (finfo.sections);
2285 if (finfo.symbuf != NULL)
2286 free (finfo.symbuf);
2287 for (o = abfd->sections; o != NULL; o = o->next)
2288 {
2289 if ((o->flags & SEC_RELOC) != 0
2290 && elf_section_data (o)->rel_hashes != NULL)
2291 free (elf_section_data (o)->rel_hashes);
2292 }
2293
2294 elf_tdata (abfd)->linker = true;
2295
2296 return true;
2297
2298 error_return:
2299 if (finfo.symstrtab != NULL)
2300 _bfd_stringtab_free (finfo.symstrtab);
2301 if (finfo.contents != NULL)
2302 free (finfo.contents);
2303 if (finfo.external_relocs != NULL)
2304 free (finfo.external_relocs);
2305 if (finfo.internal_relocs != NULL)
2306 free (finfo.internal_relocs);
2307 if (finfo.external_syms != NULL)
2308 free (finfo.external_syms);
2309 if (finfo.internal_syms != NULL)
2310 free (finfo.internal_syms);
2311 if (finfo.indices != NULL)
2312 free (finfo.indices);
2313 if (finfo.sections != NULL)
2314 free (finfo.sections);
2315 if (finfo.symbuf != NULL)
2316 free (finfo.symbuf);
2317 for (o = abfd->sections; o != NULL; o = o->next)
2318 {
2319 if ((o->flags & SEC_RELOC) != 0
2320 && elf_section_data (o)->rel_hashes != NULL)
2321 free (elf_section_data (o)->rel_hashes);
2322 }
2323
2324 return false;
2325 }
2326
2327 /* Add a symbol to the output symbol table. */
2328
2329 static boolean
2330 elf_link_output_sym (finfo, name, elfsym, input_sec)
2331 struct elf_final_link_info *finfo;
2332 const char *name;
2333 Elf_Internal_Sym *elfsym;
2334 asection *input_sec;
2335 {
2336 boolean (*output_symbol_hook) PARAMS ((bfd *,
2337 struct bfd_link_info *info,
2338 const char *,
2339 Elf_Internal_Sym *,
2340 asection *));
2341
2342 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
2343 elf_backend_link_output_symbol_hook;
2344 if (output_symbol_hook != NULL)
2345 {
2346 if (! ((*output_symbol_hook)
2347 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
2348 return false;
2349 }
2350
2351 if (name == (const char *) NULL || *name == '\0')
2352 elfsym->st_name = 0;
2353 else
2354 {
2355 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
2356 name, true,
2357 false);
2358 if (elfsym->st_name == (unsigned long) -1)
2359 return false;
2360 }
2361
2362 if (finfo->symbuf_count >= finfo->symbuf_size)
2363 {
2364 if (! elf_link_flush_output_syms (finfo))
2365 return false;
2366 }
2367
2368 elf_swap_symbol_out (finfo->output_bfd, elfsym,
2369 (PTR) (finfo->symbuf + finfo->symbuf_count));
2370 ++finfo->symbuf_count;
2371
2372 ++finfo->output_bfd->symcount;
2373
2374 return true;
2375 }
2376
2377 /* Flush the output symbols to the file. */
2378
2379 static boolean
2380 elf_link_flush_output_syms (finfo)
2381 struct elf_final_link_info *finfo;
2382 {
2383 Elf_Internal_Shdr *symtab;
2384
2385 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
2386
2387 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
2388 SEEK_SET) != 0
2389 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
2390 sizeof (Elf_External_Sym), finfo->output_bfd)
2391 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
2392 return false;
2393
2394 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
2395
2396 finfo->symbuf_count = 0;
2397
2398 return true;
2399 }
2400
2401 /* Add an external symbol to the symbol table. This is called from
2402 the hash table traversal routine. */
2403
2404 static boolean
2405 elf_link_output_extsym (h, data)
2406 struct elf_link_hash_entry *h;
2407 PTR data;
2408 {
2409 struct elf_finfo_failed *eif = (struct elf_finfo_failed *) data;
2410 struct elf_final_link_info *finfo = eif->finfo;
2411 boolean strip;
2412 Elf_Internal_Sym sym;
2413 asection *input_sec;
2414
2415 /* If we are not creating a shared library, and this symbol is
2416 referenced by a shared library but is not defined anywhere, then
2417 warn that it is undefined. If we do not do this, the runtime
2418 linker will complain that the symbol is undefined when the
2419 program is run. We don't have to worry about symbols that are
2420 referenced by regular files, because we will already have issued
2421 warnings for them. */
2422 if (! finfo->info->relocateable
2423 && ! finfo->info->shared
2424 && h->root.type == bfd_link_hash_undefined
2425 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
2426 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
2427 {
2428 if (! ((*finfo->info->callbacks->undefined_symbol)
2429 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
2430 (asection *) NULL, 0)))
2431 {
2432 eif->failed = true;
2433 return false;
2434 }
2435 }
2436
2437 /* We don't want to output symbols that have never been mentioned by
2438 a regular file, or that we have been told to strip. However, if
2439 h->indx is set to -2, the symbol is used by a reloc and we must
2440 output it. */
2441 if (h->indx == -2)
2442 strip = false;
2443 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2444 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
2445 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
2446 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
2447 strip = true;
2448 else if (finfo->info->strip == strip_all
2449 || (finfo->info->strip == strip_some
2450 && bfd_hash_lookup (finfo->info->keep_hash,
2451 h->root.root.string,
2452 false, false) == NULL))
2453 strip = true;
2454 else
2455 strip = false;
2456
2457 /* If we're stripping it, and it's not a dynamic symbol, there's
2458 nothing else to do. */
2459 if (strip && h->dynindx == -1)
2460 return true;
2461
2462 sym.st_value = 0;
2463 sym.st_size = h->size;
2464 sym.st_other = 0;
2465 if (h->root.type == bfd_link_hash_undefweak
2466 || h->root.type == bfd_link_hash_defweak)
2467 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
2468 else
2469 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
2470
2471 switch (h->root.type)
2472 {
2473 default:
2474 case bfd_link_hash_new:
2475 abort ();
2476 return false;
2477
2478 case bfd_link_hash_undefined:
2479 input_sec = bfd_und_section_ptr;
2480 sym.st_shndx = SHN_UNDEF;
2481 break;
2482
2483 case bfd_link_hash_undefweak:
2484 input_sec = bfd_und_section_ptr;
2485 sym.st_shndx = SHN_UNDEF;
2486 break;
2487
2488 case bfd_link_hash_defined:
2489 case bfd_link_hash_defweak:
2490 {
2491 input_sec = h->root.u.def.section;
2492 if (input_sec->output_section != NULL)
2493 {
2494 sym.st_shndx =
2495 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
2496 input_sec->output_section);
2497 if (sym.st_shndx == (unsigned short) -1)
2498 {
2499 eif->failed = true;
2500 return false;
2501 }
2502
2503 /* ELF symbols in relocateable files are section relative,
2504 but in nonrelocateable files they are virtual
2505 addresses. */
2506 sym.st_value = h->root.u.def.value + input_sec->output_offset;
2507 if (! finfo->info->relocateable)
2508 sym.st_value += input_sec->output_section->vma;
2509 }
2510 else
2511 {
2512 BFD_ASSERT ((bfd_get_flavour (input_sec->owner)
2513 == bfd_target_elf_flavour)
2514 && elf_elfheader (input_sec->owner)->e_type == ET_DYN);
2515 sym.st_shndx = SHN_UNDEF;
2516 input_sec = bfd_und_section_ptr;
2517 }
2518 }
2519 break;
2520
2521 case bfd_link_hash_common:
2522 input_sec = bfd_com_section_ptr;
2523 sym.st_shndx = SHN_COMMON;
2524 sym.st_value = 1 << h->root.u.c.p->alignment_power;
2525 break;
2526
2527 case bfd_link_hash_indirect:
2528 case bfd_link_hash_warning:
2529 return (elf_link_output_extsym
2530 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
2531 }
2532
2533 /* If this symbol should be put in the .dynsym section, then put it
2534 there now. We have already know the symbol index. We also fill
2535 in the entry in the .hash section. */
2536 if (h->dynindx != -1
2537 && elf_hash_table (finfo->info)->dynamic_sections_created)
2538 {
2539 struct elf_backend_data *bed;
2540 size_t bucketcount;
2541 size_t bucket;
2542 bfd_byte *bucketpos;
2543 bfd_vma chain;
2544
2545 sym.st_name = h->dynstr_index;
2546
2547 /* Give the processor backend a chance to tweak the symbol
2548 value, and also to finish up anything that needs to be done
2549 for this symbol. */
2550 bed = get_elf_backend_data (finfo->output_bfd);
2551 if (! ((*bed->elf_backend_finish_dynamic_symbol)
2552 (finfo->output_bfd, finfo->info, h, &sym)))
2553 {
2554 eif->failed = true;
2555 return false;
2556 }
2557
2558 elf_swap_symbol_out (finfo->output_bfd, &sym,
2559 (PTR) (((Elf_External_Sym *)
2560 finfo->dynsym_sec->contents)
2561 + h->dynindx));
2562
2563 bucketcount = elf_hash_table (finfo->info)->bucketcount;
2564 bucket = (bfd_elf_hash ((const unsigned char *) h->root.root.string)
2565 % bucketcount);
2566 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
2567 + (bucket + 2) * (ARCH_SIZE / 8));
2568 chain = get_word (finfo->output_bfd, bucketpos);
2569 put_word (finfo->output_bfd, h->dynindx, bucketpos);
2570 put_word (finfo->output_bfd, chain,
2571 ((bfd_byte *) finfo->hash_sec->contents
2572 + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
2573 }
2574
2575 /* If we're stripping it, then it was just a dynamic symbol, and
2576 there's nothing else to do. */
2577 if (strip)
2578 return true;
2579
2580 h->indx = finfo->output_bfd->symcount;
2581
2582 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
2583 {
2584 eif->failed = true;
2585 return false;
2586 }
2587
2588 return true;
2589 }
2590
2591 /* Link an input file into the linker output file. This function
2592 handles all the sections and relocations of the input file at once.
2593 This is so that we only have to read the local symbols once, and
2594 don't have to keep them in memory. */
2595
2596 static boolean
2597 elf_link_input_bfd (finfo, input_bfd)
2598 struct elf_final_link_info *finfo;
2599 bfd *input_bfd;
2600 {
2601 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
2602 bfd *, asection *, bfd_byte *,
2603 Elf_Internal_Rela *,
2604 Elf_Internal_Sym *, asection **));
2605 bfd *output_bfd;
2606 Elf_Internal_Shdr *symtab_hdr;
2607 size_t locsymcount;
2608 size_t extsymoff;
2609 Elf_External_Sym *esym;
2610 Elf_External_Sym *esymend;
2611 Elf_Internal_Sym *isym;
2612 long *pindex;
2613 asection **ppsection;
2614 asection *o;
2615
2616 output_bfd = finfo->output_bfd;
2617 relocate_section =
2618 get_elf_backend_data (output_bfd)->elf_backend_relocate_section;
2619
2620 /* If this is a dynamic object, we don't want to do anything here:
2621 we don't want the local symbols, and we don't want the section
2622 contents. */
2623 if (elf_elfheader (input_bfd)->e_type == ET_DYN)
2624 return true;
2625
2626 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
2627 if (elf_bad_symtab (input_bfd))
2628 {
2629 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
2630 extsymoff = 0;
2631 }
2632 else
2633 {
2634 locsymcount = symtab_hdr->sh_info;
2635 extsymoff = symtab_hdr->sh_info;
2636 }
2637
2638 /* Read the local symbols. */
2639 if (locsymcount > 0
2640 && (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
2641 || (bfd_read (finfo->external_syms, sizeof (Elf_External_Sym),
2642 locsymcount, input_bfd)
2643 != locsymcount * sizeof (Elf_External_Sym))))
2644 return false;
2645
2646 /* Swap in the local symbols and write out the ones which we know
2647 are going into the output file. */
2648 esym = finfo->external_syms;
2649 esymend = esym + locsymcount;
2650 isym = finfo->internal_syms;
2651 pindex = finfo->indices;
2652 ppsection = finfo->sections;
2653 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
2654 {
2655 asection *isec;
2656 const char *name;
2657 Elf_Internal_Sym osym;
2658
2659 elf_swap_symbol_in (input_bfd, esym, isym);
2660 *pindex = -1;
2661
2662 if (elf_bad_symtab (input_bfd))
2663 {
2664 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
2665 {
2666 *ppsection = NULL;
2667 continue;
2668 }
2669 }
2670
2671 if (isym->st_shndx == SHN_UNDEF)
2672 isec = bfd_und_section_ptr;
2673 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
2674 isec = section_from_elf_index (input_bfd, isym->st_shndx);
2675 else if (isym->st_shndx == SHN_ABS)
2676 isec = bfd_abs_section_ptr;
2677 else if (isym->st_shndx == SHN_COMMON)
2678 isec = bfd_com_section_ptr;
2679 else
2680 {
2681 /* Who knows? */
2682 isec = NULL;
2683 }
2684
2685 *ppsection = isec;
2686
2687 /* Don't output the first, undefined, symbol. */
2688 if (esym == finfo->external_syms)
2689 continue;
2690
2691 /* If we are stripping all symbols, we don't want to output this
2692 one. */
2693 if (finfo->info->strip == strip_all)
2694 continue;
2695
2696 /* We never output section symbols. Instead, we use the section
2697 symbol of the corresponding section in the output file. */
2698 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
2699 continue;
2700
2701 /* If we are discarding all local symbols, we don't want to
2702 output this one. If we are generating a relocateable output
2703 file, then some of the local symbols may be required by
2704 relocs; we output them below as we discover that they are
2705 needed. */
2706 if (finfo->info->discard == discard_all)
2707 continue;
2708
2709 /* Get the name of the symbol. */
2710 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
2711 isym->st_name);
2712 if (name == NULL)
2713 return false;
2714
2715 /* See if we are discarding symbols with this name. */
2716 if ((finfo->info->strip == strip_some
2717 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
2718 == NULL))
2719 || (finfo->info->discard == discard_l
2720 && strncmp (name, finfo->info->lprefix,
2721 finfo->info->lprefix_len) == 0))
2722 continue;
2723
2724 /* If we get here, we are going to output this symbol. */
2725
2726 osym = *isym;
2727
2728 /* Adjust the section index for the output file. */
2729 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
2730 isec->output_section);
2731 if (osym.st_shndx == (unsigned short) -1)
2732 return false;
2733
2734 *pindex = output_bfd->symcount;
2735
2736 /* ELF symbols in relocateable files are section relative, but
2737 in executable files they are virtual addresses. Note that
2738 this code assumes that all ELF sections have an associated
2739 BFD section with a reasonable value for output_offset; below
2740 we assume that they also have a reasonable value for
2741 output_section. Any special sections must be set up to meet
2742 these requirements. */
2743 osym.st_value += isec->output_offset;
2744 if (! finfo->info->relocateable)
2745 osym.st_value += isec->output_section->vma;
2746
2747 if (! elf_link_output_sym (finfo, name, &osym, isec))
2748 return false;
2749 }
2750
2751 /* Relocate the contents of each section. */
2752 for (o = input_bfd->sections; o != NULL; o = o->next)
2753 {
2754 if ((o->flags & SEC_HAS_CONTENTS) == 0)
2755 continue;
2756
2757 if ((o->flags & SEC_IN_MEMORY) != 0
2758 && input_bfd == elf_hash_table (finfo->info)->dynobj)
2759 {
2760 /* Section was created by elf_link_create_dynamic_sections.
2761 FIXME: This test is fragile. */
2762 continue;
2763 }
2764
2765 /* Read the contents of the section. */
2766 if (! bfd_get_section_contents (input_bfd, o, finfo->contents,
2767 (file_ptr) 0, o->_raw_size))
2768 return false;
2769
2770 if ((o->flags & SEC_RELOC) != 0)
2771 {
2772 Elf_Internal_Rela *internal_relocs;
2773
2774 /* Get the swapped relocs. */
2775 internal_relocs = elf_link_read_relocs (input_bfd, o,
2776 finfo->external_relocs,
2777 finfo->internal_relocs,
2778 false);
2779 if (internal_relocs == NULL
2780 && o->reloc_count > 0)
2781 return false;
2782
2783 /* Relocate the section by invoking a back end routine.
2784
2785 The back end routine is responsible for adjusting the
2786 section contents as necessary, and (if using Rela relocs
2787 and generating a relocateable output file) adjusting the
2788 reloc addend as necessary.
2789
2790 The back end routine does not have to worry about setting
2791 the reloc address or the reloc symbol index.
2792
2793 The back end routine is given a pointer to the swapped in
2794 internal symbols, and can access the hash table entries
2795 for the external symbols via elf_sym_hashes (input_bfd).
2796
2797 When generating relocateable output, the back end routine
2798 must handle STB_LOCAL/STT_SECTION symbols specially. The
2799 output symbol is going to be a section symbol
2800 corresponding to the output section, which will require
2801 the addend to be adjusted. */
2802
2803 if (! (*relocate_section) (output_bfd, finfo->info,
2804 input_bfd, o,
2805 finfo->contents,
2806 internal_relocs,
2807 finfo->internal_syms,
2808 finfo->sections))
2809 return false;
2810
2811 if (finfo->info->relocateable)
2812 {
2813 Elf_Internal_Rela *irela;
2814 Elf_Internal_Rela *irelaend;
2815 struct elf_link_hash_entry **rel_hash;
2816 Elf_Internal_Shdr *input_rel_hdr;
2817 Elf_Internal_Shdr *output_rel_hdr;
2818
2819 /* Adjust the reloc addresses and symbol indices. */
2820
2821 irela = internal_relocs;
2822 irelaend = irela + o->reloc_count;
2823 rel_hash = (elf_section_data (o->output_section)->rel_hashes
2824 + o->output_section->reloc_count);
2825 for (; irela < irelaend; irela++, rel_hash++)
2826 {
2827 unsigned long r_symndx;
2828 Elf_Internal_Sym *isym;
2829 asection *sec;
2830
2831 irela->r_offset += o->output_offset;
2832
2833 r_symndx = ELF_R_SYM (irela->r_info);
2834
2835 if (r_symndx == 0)
2836 continue;
2837
2838 if (r_symndx >= locsymcount
2839 || (elf_bad_symtab (input_bfd)
2840 && finfo->sections[r_symndx] == NULL))
2841 {
2842 long indx;
2843
2844 /* This is a reloc against a global symbol. We
2845 have not yet output all the local symbols, so
2846 we do not know the symbol index of any global
2847 symbol. We set the rel_hash entry for this
2848 reloc to point to the global hash table entry
2849 for this symbol. The symbol index is then
2850 set at the end of elf_bfd_final_link. */
2851 indx = r_symndx - extsymoff;
2852 *rel_hash = elf_sym_hashes (input_bfd)[indx];
2853
2854 /* Setting the index to -2 tells
2855 elf_link_output_extsym that this symbol is
2856 used by a reloc. */
2857 BFD_ASSERT ((*rel_hash)->indx < 0);
2858 (*rel_hash)->indx = -2;
2859
2860 continue;
2861 }
2862
2863 /* This is a reloc against a local symbol. */
2864
2865 *rel_hash = NULL;
2866 isym = finfo->internal_syms + r_symndx;
2867 sec = finfo->sections[r_symndx];
2868 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
2869 {
2870 /* I suppose the backend ought to fill in the
2871 section of any STT_SECTION symbol against a
2872 processor specific section. */
2873 if (sec != NULL && bfd_is_abs_section (sec))
2874 r_symndx = 0;
2875 else if (sec == NULL || sec->owner == NULL)
2876 {
2877 bfd_set_error (bfd_error_bad_value);
2878 return false;
2879 }
2880 else
2881 {
2882 r_symndx = sec->output_section->target_index;
2883 BFD_ASSERT (r_symndx != 0);
2884 }
2885 }
2886 else
2887 {
2888 if (finfo->indices[r_symndx] == -1)
2889 {
2890 unsigned long link;
2891 const char *name;
2892 asection *osec;
2893
2894 if (finfo->info->strip == strip_all)
2895 {
2896 /* You can't do ld -r -s. */
2897 bfd_set_error (bfd_error_invalid_operation);
2898 return false;
2899 }
2900
2901 /* This symbol was skipped earlier, but
2902 since it is needed by a reloc, we
2903 must output it now. */
2904 link = symtab_hdr->sh_link;
2905 name = bfd_elf_string_from_elf_section (input_bfd,
2906 link,
2907 isym->st_name);
2908 if (name == NULL)
2909 return false;
2910
2911 osec = sec->output_section;
2912 isym->st_shndx =
2913 _bfd_elf_section_from_bfd_section (output_bfd,
2914 osec);
2915 if (isym->st_shndx == (unsigned short) -1)
2916 return false;
2917
2918 isym->st_value += sec->output_offset;
2919 if (! finfo->info->relocateable)
2920 isym->st_value += osec->vma;
2921
2922 finfo->indices[r_symndx] = output_bfd->symcount;
2923
2924 if (! elf_link_output_sym (finfo, name, isym, sec))
2925 return false;
2926 }
2927
2928 r_symndx = finfo->indices[r_symndx];
2929 }
2930
2931 irela->r_info = ELF_R_INFO (r_symndx,
2932 ELF_R_TYPE (irela->r_info));
2933 }
2934
2935 /* Swap out the relocs. */
2936 input_rel_hdr = &elf_section_data (o)->rel_hdr;
2937 output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
2938 BFD_ASSERT (output_rel_hdr->sh_entsize
2939 == input_rel_hdr->sh_entsize);
2940 irela = internal_relocs;
2941 irelaend = irela + o->reloc_count;
2942 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
2943 {
2944 Elf_External_Rel *erel;
2945
2946 erel = ((Elf_External_Rel *) output_rel_hdr->contents
2947 + o->output_section->reloc_count);
2948 for (; irela < irelaend; irela++, erel++)
2949 {
2950 Elf_Internal_Rel irel;
2951
2952 irel.r_offset = irela->r_offset;
2953 irel.r_info = irela->r_info;
2954 BFD_ASSERT (irela->r_addend == 0);
2955 elf_swap_reloc_out (output_bfd, &irel, erel);
2956 }
2957 }
2958 else
2959 {
2960 Elf_External_Rela *erela;
2961
2962 BFD_ASSERT (input_rel_hdr->sh_entsize
2963 == sizeof (Elf_External_Rela));
2964 erela = ((Elf_External_Rela *) output_rel_hdr->contents
2965 + o->output_section->reloc_count);
2966 for (; irela < irelaend; irela++, erela++)
2967 elf_swap_reloca_out (output_bfd, irela, erela);
2968 }
2969
2970 o->output_section->reloc_count += o->reloc_count;
2971 }
2972 }
2973
2974 /* Write out the modified section contents. */
2975 if (! bfd_set_section_contents (output_bfd, o->output_section,
2976 finfo->contents, o->output_offset,
2977 (o->_cooked_size != 0
2978 ? o->_cooked_size
2979 : o->_raw_size)))
2980 return false;
2981 }
2982
2983 return true;
2984 }
2985
2986 /* Generate a reloc when linking an ELF file. This is a reloc
2987 requested by the linker, and does come from any input file. This
2988 is used to build constructor and destructor tables when linking
2989 with -Ur. */
2990
2991 static boolean
2992 elf_reloc_link_order (output_bfd, info, output_section, link_order)
2993 bfd *output_bfd;
2994 struct bfd_link_info *info;
2995 asection *output_section;
2996 struct bfd_link_order *link_order;
2997 {
2998 reloc_howto_type *howto;
2999 long indx;
3000 bfd_vma offset;
3001 struct elf_link_hash_entry **rel_hash_ptr;
3002 Elf_Internal_Shdr *rel_hdr;
3003
3004 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
3005 if (howto == NULL)
3006 {
3007 bfd_set_error (bfd_error_bad_value);
3008 return false;
3009 }
3010
3011 /* If this is an inplace reloc, we must write the addend into the
3012 object file. */
3013 if (howto->partial_inplace
3014 && link_order->u.reloc.p->addend != 0)
3015 {
3016 bfd_size_type size;
3017 bfd_reloc_status_type rstat;
3018 bfd_byte *buf;
3019 boolean ok;
3020
3021 size = bfd_get_reloc_size (howto);
3022 buf = (bfd_byte *) bfd_zmalloc (size);
3023 if (buf == (bfd_byte *) NULL)
3024 {
3025 bfd_set_error (bfd_error_no_memory);
3026 return false;
3027 }
3028 rstat = _bfd_relocate_contents (howto, output_bfd,
3029 link_order->u.reloc.p->addend, buf);
3030 switch (rstat)
3031 {
3032 case bfd_reloc_ok:
3033 break;
3034 default:
3035 case bfd_reloc_outofrange:
3036 abort ();
3037 case bfd_reloc_overflow:
3038 if (! ((*info->callbacks->reloc_overflow)
3039 (info,
3040 (link_order->type == bfd_section_reloc_link_order
3041 ? bfd_section_name (output_bfd,
3042 link_order->u.reloc.p->u.section)
3043 : link_order->u.reloc.p->u.name),
3044 howto->name, link_order->u.reloc.p->addend,
3045 (bfd *) NULL, (asection *) NULL, (bfd_vma) 0)))
3046 {
3047 free (buf);
3048 return false;
3049 }
3050 break;
3051 }
3052 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
3053 (file_ptr) link_order->offset, size);
3054 free (buf);
3055 if (! ok)
3056 return false;
3057 }
3058
3059 /* Figure out the symbol index. */
3060 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
3061 + output_section->reloc_count);
3062 if (link_order->type == bfd_section_reloc_link_order)
3063 {
3064 indx = link_order->u.reloc.p->u.section->target_index;
3065 BFD_ASSERT (indx != 0);
3066 *rel_hash_ptr = NULL;
3067 }
3068 else
3069 {
3070 struct elf_link_hash_entry *h;
3071
3072 h = elf_link_hash_lookup (elf_hash_table (info),
3073 link_order->u.reloc.p->u.name,
3074 false, false, true);
3075 if (h != NULL)
3076 {
3077 /* Setting the index to -2 tells elf_link_output_extsym that
3078 this symbol is used by a reloc. */
3079 h->indx = -2;
3080 *rel_hash_ptr = h;
3081 indx = 0;
3082 }
3083 else
3084 {
3085 if (! ((*info->callbacks->unattached_reloc)
3086 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
3087 (asection *) NULL, (bfd_vma) 0)))
3088 return false;
3089 indx = 0;
3090 }
3091 }
3092
3093 /* The address of a reloc is relative to the section in a
3094 relocateable file, and is a virtual address in an executable
3095 file. */
3096 offset = link_order->offset;
3097 if (! info->relocateable)
3098 offset += output_section->vma;
3099
3100 rel_hdr = &elf_section_data (output_section)->rel_hdr;
3101
3102 if (rel_hdr->sh_type == SHT_REL)
3103 {
3104 Elf_Internal_Rel irel;
3105 Elf_External_Rel *erel;
3106
3107 irel.r_offset = offset;
3108 irel.r_info = ELF_R_INFO (indx, howto->type);
3109 erel = ((Elf_External_Rel *) rel_hdr->contents
3110 + output_section->reloc_count);
3111 elf_swap_reloc_out (output_bfd, &irel, erel);
3112 }
3113 else
3114 {
3115 Elf_Internal_Rela irela;
3116 Elf_External_Rela *erela;
3117
3118 irela.r_offset = offset;
3119 irela.r_info = ELF_R_INFO (indx, howto->type);
3120 irela.r_addend = link_order->u.reloc.p->addend;
3121 erela = ((Elf_External_Rela *) rel_hdr->contents
3122 + output_section->reloc_count);
3123 elf_swap_reloca_out (output_bfd, &irela, erela);
3124 }
3125
3126 ++output_section->reloc_count;
3127
3128 return true;
3129 }
3130