Fri Sep 1 15:18:50 1995 Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>
[deliverable/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 sec = bfd_und_section_ptr;
671 }
672
673 /* Similarly, if we are not looking at a dynamic object, and
674 we have a definition, we want to override any definition
675 we may have from a dynamic object. Symbols from regular
676 files always take precedence over symbols from dynamic
677 objects, even if they are defined after the dynamic
678 object in the link. */
679 if (! dynamic
680 && definition
681 && (h->root.type == bfd_link_hash_defined
682 || h->root.type == bfd_link_hash_defweak)
683 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
684 && (bfd_get_flavour (h->root.u.def.section->owner)
685 == bfd_target_elf_flavour)
686 && (elf_elfheader (h->root.u.def.section->owner)->e_type
687 == ET_DYN))
688 {
689 /* Change the hash table entry to undefined, and let
690 _bfd_generic_link_add_one_symbol do the right thing
691 with the new definition. */
692 h->root.type = bfd_link_hash_undefined;
693 h->root.u.undef.abfd = h->root.u.def.section->owner;
694 }
695 }
696
697 if (! (_bfd_generic_link_add_one_symbol
698 (info, abfd, name, flags, sec, value, (const char *) NULL,
699 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
700 goto error_return;
701
702 h = *sym_hash;
703 while (h->root.type == bfd_link_hash_indirect
704 || h->root.type == bfd_link_hash_warning)
705 h = (struct elf_link_hash_entry *) h->root.u.i.link;
706 *sym_hash = h;
707
708 new_weakdef = false;
709 if (dynamic
710 && definition
711 && (flags & BSF_WEAK) != 0
712 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
713 && info->hash->creator->flavour == bfd_target_elf_flavour
714 && h->weakdef == NULL)
715 {
716 /* Keep a list of all weak defined non function symbols from
717 a dynamic object, using the weakdef field. Later in this
718 function we will set the weakdef field to the correct
719 value. We only put non-function symbols from dynamic
720 objects on this list, because that happens to be the only
721 time we need to know the normal symbol corresponding to a
722 weak symbol, and the information is time consuming to
723 figure out. If the weakdef field is not already NULL,
724 then this symbol was already defined by some previous
725 dynamic object, and we will be using that previous
726 definition anyhow. */
727
728 h->weakdef = weaks;
729 weaks = h;
730 new_weakdef = true;
731 }
732
733 /* Get the alignment of a common symbol. */
734 if (sym.st_shndx == SHN_COMMON
735 && h->root.type == bfd_link_hash_common)
736 h->root.u.c.p->alignment_power = bfd_log2 (sym.st_value);
737
738 if (info->hash->creator->flavour == bfd_target_elf_flavour)
739 {
740 int old_flags;
741 boolean dynsym;
742 int new_flag;
743
744 /* Remember the symbol size and type. */
745 if (sym.st_size != 0)
746 {
747 /* FIXME: We should probably somehow give a warning if
748 the symbol size changes. */
749 h->size = sym.st_size;
750 }
751 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE)
752 {
753 /* FIXME: We should probably somehow give a warning if
754 the symbol type changes. */
755 h->type = ELF_ST_TYPE (sym.st_info);
756 }
757
758 /* Set a flag in the hash table entry indicating the type of
759 reference or definition we just found. Keep a count of
760 the number of dynamic symbols we find. A dynamic symbol
761 is one which is referenced or defined by both a regular
762 object and a shared object, or one which is referenced or
763 defined by more than one shared object. */
764 old_flags = h->elf_link_hash_flags;
765 dynsym = false;
766 if (! dynamic)
767 {
768 if (! definition)
769 new_flag = ELF_LINK_HASH_REF_REGULAR;
770 else
771 new_flag = ELF_LINK_HASH_DEF_REGULAR;
772 if (info->shared
773 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
774 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
775 dynsym = true;
776 }
777 else
778 {
779 if (! definition)
780 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
781 else
782 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
783 if ((old_flags & new_flag) != 0
784 || (old_flags & (ELF_LINK_HASH_DEF_REGULAR
785 | ELF_LINK_HASH_REF_REGULAR)) != 0
786 || (h->weakdef != NULL
787 && (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
788 | ELF_LINK_HASH_REF_DYNAMIC)) != 0))
789 dynsym = true;
790 }
791
792 h->elf_link_hash_flags |= new_flag;
793 if (dynsym && h->dynindx == -1)
794 {
795 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
796 goto error_return;
797 if (h->weakdef != NULL
798 && ! new_weakdef
799 && h->weakdef->dynindx == -1)
800 {
801 if (! _bfd_elf_link_record_dynamic_symbol (info,
802 h->weakdef))
803 goto error_return;
804 }
805 }
806 }
807 }
808
809 /* Now set the weakdefs field correctly for all the weak defined
810 symbols we found. The only way to do this is to search all the
811 symbols. Since we only need the information for non functions in
812 dynamic objects, that's the only time we actually put anything on
813 the list WEAKS. We need this information so that if a regular
814 object refers to a symbol defined weakly in a dynamic object, the
815 real symbol in the dynamic object is also put in the dynamic
816 symbols; we also must arrange for both symbols to point to the
817 same memory location. We could handle the general case of symbol
818 aliasing, but a general symbol alias can only be generated in
819 assembler code, handling it correctly would be very time
820 consuming, and other ELF linkers don't handle general aliasing
821 either. */
822 while (weaks != NULL)
823 {
824 struct elf_link_hash_entry *hlook;
825 asection *slook;
826 bfd_vma vlook;
827 struct elf_link_hash_entry **hpp;
828 struct elf_link_hash_entry **hppend;
829
830 hlook = weaks;
831 weaks = hlook->weakdef;
832 hlook->weakdef = NULL;
833
834 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
835 || hlook->root.type == bfd_link_hash_defweak
836 || hlook->root.type == bfd_link_hash_common
837 || hlook->root.type == bfd_link_hash_indirect);
838 slook = hlook->root.u.def.section;
839 vlook = hlook->root.u.def.value;
840
841 hpp = elf_sym_hashes (abfd);
842 hppend = hpp + extsymcount;
843 for (; hpp < hppend; hpp++)
844 {
845 struct elf_link_hash_entry *h;
846
847 h = *hpp;
848 if (h != NULL && h != hlook
849 && (h->root.type == bfd_link_hash_defined
850 || h->root.type == bfd_link_hash_defweak)
851 && h->root.u.def.section == slook
852 && h->root.u.def.value == vlook)
853 {
854 hlook->weakdef = h;
855
856 /* If the weak definition is in the list of dynamic
857 symbols, make sure the real definition is put there
858 as well. */
859 if (hlook->dynindx != -1
860 && h->dynindx == -1)
861 {
862 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
863 goto error_return;
864 }
865
866 break;
867 }
868 }
869 }
870
871 if (buf != NULL)
872 {
873 free (buf);
874 buf = NULL;
875 }
876
877 /* If this object is the same format as the output object, and it is
878 not a shared library, then let the backend look through the
879 relocs.
880
881 This is required to build global offset table entries and to
882 arrange for dynamic relocs. It is not required for the
883 particular common case of linking non PIC code, even when linking
884 against shared libraries, but unfortunately there is no way of
885 knowing whether an object file has been compiled PIC or not.
886 Looking through the relocs is not particularly time consuming.
887 The problem is that we must either (1) keep the relocs in memory,
888 which causes the linker to require additional runtime memory or
889 (2) read the relocs twice from the input file, which wastes time.
890 This would be a good case for using mmap.
891
892 I have no idea how to handle linking PIC code into a file of a
893 different format. It probably can't be done. */
894 check_relocs = get_elf_backend_data (abfd)->check_relocs;
895 if (! dynamic
896 && abfd->xvec == info->hash->creator
897 && check_relocs != NULL)
898 {
899 asection *o;
900
901 for (o = abfd->sections; o != NULL; o = o->next)
902 {
903 Elf_Internal_Rela *internal_relocs;
904 boolean ok;
905
906 if ((o->flags & SEC_RELOC) == 0
907 || o->reloc_count == 0)
908 continue;
909
910 /* I believe we can ignore the relocs for any section which
911 does not form part of the final process image, such as a
912 debugging section. */
913 if ((o->flags & SEC_ALLOC) == 0)
914 continue;
915
916 internal_relocs = elf_link_read_relocs (abfd, o, (PTR) NULL,
917 (Elf_Internal_Rela *) NULL,
918 info->keep_memory);
919 if (internal_relocs == NULL)
920 goto error_return;
921
922 ok = (*check_relocs) (abfd, info, o, internal_relocs);
923
924 if (! info->keep_memory)
925 free (internal_relocs);
926
927 if (! ok)
928 goto error_return;
929 }
930 }
931
932 return true;
933
934 error_return:
935 if (buf != NULL)
936 free (buf);
937 if (dynbuf != NULL)
938 free (dynbuf);
939 return false;
940 }
941
942 /* Create some sections which will be filled in with dynamic linking
943 information. ABFD is an input file which requires dynamic sections
944 to be created. The dynamic sections take up virtual memory space
945 when the final executable is run, so we need to create them before
946 addresses are assigned to the output sections. We work out the
947 actual contents and size of these sections later. */
948
949 boolean
950 elf_link_create_dynamic_sections (abfd, info)
951 bfd *abfd;
952 struct bfd_link_info *info;
953 {
954 flagword flags;
955 register asection *s;
956 struct elf_link_hash_entry *h;
957 struct elf_backend_data *bed;
958
959 if (elf_hash_table (info)->dynamic_sections_created)
960 return true;
961
962 /* Make sure that all dynamic sections use the same input BFD. */
963 if (elf_hash_table (info)->dynobj == NULL)
964 elf_hash_table (info)->dynobj = abfd;
965 else
966 abfd = elf_hash_table (info)->dynobj;
967
968 /* Note that we set the SEC_IN_MEMORY flag for all of these
969 sections. */
970 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
971
972 /* A dynamically linked executable has a .interp section, but a
973 shared library does not. */
974 if (! info->shared)
975 {
976 s = bfd_make_section (abfd, ".interp");
977 if (s == NULL
978 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
979 return false;
980 }
981
982 s = bfd_make_section (abfd, ".dynsym");
983 if (s == NULL
984 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
985 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
986 return false;
987
988 s = bfd_make_section (abfd, ".dynstr");
989 if (s == NULL
990 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
991 return false;
992
993 /* Create a strtab to hold the dynamic symbol names. */
994 if (elf_hash_table (info)->dynstr == NULL)
995 {
996 elf_hash_table (info)->dynstr = elf_stringtab_init ();
997 if (elf_hash_table (info)->dynstr == NULL)
998 return false;
999 }
1000
1001 s = bfd_make_section (abfd, ".dynamic");
1002 if (s == NULL
1003 || ! bfd_set_section_flags (abfd, s, flags)
1004 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1005 return false;
1006
1007 /* The special symbol _DYNAMIC is always set to the start of the
1008 .dynamic section. This call occurs before we have processed the
1009 symbols for any dynamic object, so we don't have to worry about
1010 overriding a dynamic definition. We could set _DYNAMIC in a
1011 linker script, but we only want to define it if we are, in fact,
1012 creating a .dynamic section. We don't want to define it if there
1013 is no .dynamic section, since on some ELF platforms the start up
1014 code examines it to decide how to initialize the process. */
1015 h = NULL;
1016 if (! (_bfd_generic_link_add_one_symbol
1017 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
1018 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
1019 (struct bfd_link_hash_entry **) &h)))
1020 return false;
1021 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1022 h->type = STT_OBJECT;
1023
1024 if (info->shared
1025 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
1026 return false;
1027
1028 s = bfd_make_section (abfd, ".hash");
1029 if (s == NULL
1030 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1031 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1032 return false;
1033
1034 /* Let the backend create the rest of the sections. This lets the
1035 backend set the right flags. The backend will normally create
1036 the .got and .plt sections. */
1037 bed = get_elf_backend_data (abfd);
1038 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
1039 return false;
1040
1041 elf_hash_table (info)->dynamic_sections_created = true;
1042
1043 return true;
1044 }
1045
1046 /* Add an entry to the .dynamic table. */
1047
1048 boolean
1049 elf_add_dynamic_entry (info, tag, val)
1050 struct bfd_link_info *info;
1051 bfd_vma tag;
1052 bfd_vma val;
1053 {
1054 Elf_Internal_Dyn dyn;
1055 bfd *dynobj;
1056 asection *s;
1057 size_t newsize;
1058 bfd_byte *newcontents;
1059
1060 dynobj = elf_hash_table (info)->dynobj;
1061
1062 s = bfd_get_section_by_name (dynobj, ".dynamic");
1063 BFD_ASSERT (s != NULL);
1064
1065 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
1066 if (s->contents == NULL)
1067 newcontents = (bfd_byte *) malloc (newsize);
1068 else
1069 newcontents = (bfd_byte *) realloc (s->contents, newsize);
1070 if (newcontents == NULL)
1071 {
1072 bfd_set_error (bfd_error_no_memory);
1073 return false;
1074 }
1075
1076 dyn.d_tag = tag;
1077 dyn.d_un.d_val = val;
1078 elf_swap_dyn_out (dynobj, &dyn,
1079 (Elf_External_Dyn *) (newcontents + s->_raw_size));
1080
1081 s->_raw_size = newsize;
1082 s->contents = newcontents;
1083
1084 return true;
1085 }
1086
1087 /* Read and swap the relocs for a section. They may have been cached.
1088 If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL,
1089 they are used as buffers to read into. They are known to be large
1090 enough. If the INTERNAL_RELOCS relocs argument is NULL, the return
1091 value is allocated using either malloc or bfd_alloc, according to
1092 the KEEP_MEMORY argument. */
1093
1094 static Elf_Internal_Rela *
1095 elf_link_read_relocs (abfd, o, external_relocs, internal_relocs, keep_memory)
1096 bfd *abfd;
1097 asection *o;
1098 PTR external_relocs;
1099 Elf_Internal_Rela *internal_relocs;
1100 boolean keep_memory;
1101 {
1102 Elf_Internal_Shdr *rel_hdr;
1103 PTR alloc1 = NULL;
1104 Elf_Internal_Rela *alloc2 = NULL;
1105
1106 if (elf_section_data (o)->relocs != NULL)
1107 return elf_section_data (o)->relocs;
1108
1109 if (o->reloc_count == 0)
1110 return NULL;
1111
1112 rel_hdr = &elf_section_data (o)->rel_hdr;
1113
1114 if (internal_relocs == NULL)
1115 {
1116 size_t size;
1117
1118 size = o->reloc_count * sizeof (Elf_Internal_Rela);
1119 if (keep_memory)
1120 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
1121 else
1122 internal_relocs = alloc2 = (Elf_Internal_Rela *) malloc (size);
1123 if (internal_relocs == NULL)
1124 {
1125 bfd_set_error (bfd_error_no_memory);
1126 goto error_return;
1127 }
1128 }
1129
1130 if (external_relocs == NULL)
1131 {
1132 alloc1 = (PTR) malloc ((size_t) rel_hdr->sh_size);
1133 if (alloc1 == NULL)
1134 {
1135 bfd_set_error (bfd_error_no_memory);
1136 goto error_return;
1137 }
1138 external_relocs = alloc1;
1139 }
1140
1141 if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
1142 || (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd)
1143 != rel_hdr->sh_size))
1144 goto error_return;
1145
1146 /* Swap in the relocs. For convenience, we always produce an
1147 Elf_Internal_Rela array; if the relocs are Rel, we set the addend
1148 to 0. */
1149 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
1150 {
1151 Elf_External_Rel *erel;
1152 Elf_External_Rel *erelend;
1153 Elf_Internal_Rela *irela;
1154
1155 erel = (Elf_External_Rel *) external_relocs;
1156 erelend = erel + o->reloc_count;
1157 irela = internal_relocs;
1158 for (; erel < erelend; erel++, irela++)
1159 {
1160 Elf_Internal_Rel irel;
1161
1162 elf_swap_reloc_in (abfd, erel, &irel);
1163 irela->r_offset = irel.r_offset;
1164 irela->r_info = irel.r_info;
1165 irela->r_addend = 0;
1166 }
1167 }
1168 else
1169 {
1170 Elf_External_Rela *erela;
1171 Elf_External_Rela *erelaend;
1172 Elf_Internal_Rela *irela;
1173
1174 BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela));
1175
1176 erela = (Elf_External_Rela *) external_relocs;
1177 erelaend = erela + o->reloc_count;
1178 irela = internal_relocs;
1179 for (; erela < erelaend; erela++, irela++)
1180 elf_swap_reloca_in (abfd, erela, irela);
1181 }
1182
1183 /* Cache the results for next time, if we can. */
1184 if (keep_memory)
1185 elf_section_data (o)->relocs = internal_relocs;
1186
1187 if (alloc1 != NULL)
1188 free (alloc1);
1189
1190 /* Don't free alloc2, since if it was allocated we are passing it
1191 back (under the name of internal_relocs). */
1192
1193 return internal_relocs;
1194
1195 error_return:
1196 if (alloc1 != NULL)
1197 free (alloc1);
1198 if (alloc2 != NULL)
1199 free (alloc2);
1200 return NULL;
1201 }
1202
1203 /* Record an assignment to a symbol made by a linker script. We need
1204 this in case some dynamic object refers to this symbol. */
1205
1206 /*ARGSUSED*/
1207 boolean
1208 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
1209 bfd *output_bfd;
1210 struct bfd_link_info *info;
1211 const char *name;
1212 boolean provide;
1213 {
1214 struct elf_link_hash_entry *h;
1215
1216 if (info->hash->creator->flavour != bfd_target_elf_flavour)
1217 return true;
1218
1219 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
1220 if (h == NULL)
1221 return false;
1222
1223 /* If this symbol is being provided by the linker script, and it is
1224 currently defined by a dynamic object, but not by a regular
1225 object, then mark it as undefined so that the generic linker will
1226 force the correct value. */
1227 if (provide
1228 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
1229 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1230 h->root.type = bfd_link_hash_undefined;
1231
1232 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1233 h->type = STT_OBJECT;
1234
1235 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1236 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
1237 || info->shared)
1238 && h->dynindx == -1)
1239 {
1240 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1241 return false;
1242
1243 /* If this is a weak defined symbol, and we know a corresponding
1244 real symbol from the same dynamic object, make sure the real
1245 symbol is also made into a dynamic symbol. */
1246 if (h->weakdef != NULL
1247 && h->weakdef->dynindx == -1)
1248 {
1249 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
1250 return false;
1251 }
1252 }
1253
1254 return true;
1255 }
1256
1257 /* Array used to determine the number of hash table buckets to use
1258 based on the number of symbols there are. If there are fewer than
1259 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
1260 fewer than 37 we use 17 buckets, and so forth. We never use more
1261 than 521 buckets. */
1262
1263 static const size_t elf_buckets[] =
1264 {
1265 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 0
1266 };
1267
1268 /* Set up the sizes and contents of the ELF dynamic sections. This is
1269 called by the ELF linker emulation before_allocation routine. We
1270 must set the sizes of the sections before the linker sets the
1271 addresses of the various sections. */
1272
1273 boolean
1274 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
1275 export_dynamic, info, sinterpptr)
1276 bfd *output_bfd;
1277 const char *soname;
1278 const char *rpath;
1279 boolean export_dynamic;
1280 struct bfd_link_info *info;
1281 asection **sinterpptr;
1282 {
1283 bfd *dynobj;
1284 struct elf_backend_data *bed;
1285
1286 *sinterpptr = NULL;
1287
1288 if (info->hash->creator->flavour != bfd_target_elf_flavour)
1289 return true;
1290
1291 dynobj = elf_hash_table (info)->dynobj;
1292
1293 /* If there were no dynamic objects in the link, there is nothing to
1294 do here. */
1295 if (dynobj == NULL)
1296 return true;
1297
1298 /* If we are supposed to export all symbols into the dynamic symbol
1299 table (this is not the normal case), then do so. */
1300 if (export_dynamic)
1301 {
1302 struct elf_info_failed eif;
1303
1304 eif.failed = false;
1305 eif.info = info;
1306 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
1307 (PTR) &eif);
1308 if (eif.failed)
1309 return false;
1310 }
1311
1312 if (elf_hash_table (info)->dynamic_sections_created)
1313 {
1314 struct elf_info_failed eif;
1315 bfd_size_type strsize;
1316
1317 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
1318 BFD_ASSERT (*sinterpptr != NULL || info->shared);
1319
1320 if (soname != NULL)
1321 {
1322 bfd_size_type indx;
1323
1324 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, soname,
1325 true, true);
1326 if (indx == (bfd_size_type) -1
1327 || ! elf_add_dynamic_entry (info, DT_SONAME, indx))
1328 return false;
1329 }
1330
1331 if (info->symbolic)
1332 {
1333 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
1334 return false;
1335 }
1336
1337 if (rpath != NULL)
1338 {
1339 bfd_size_type indx;
1340
1341 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
1342 true, true);
1343 if (indx == (bfd_size_type) -1
1344 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
1345 return false;
1346 }
1347
1348 /* Find all symbols which were defined in a dynamic object and make
1349 the backend pick a reasonable value for them. */
1350 eif.failed = false;
1351 eif.info = info;
1352 elf_link_hash_traverse (elf_hash_table (info),
1353 elf_adjust_dynamic_symbol,
1354 (PTR) &eif);
1355 if (eif.failed)
1356 return false;
1357
1358 /* Add some entries to the .dynamic section. We fill in some of the
1359 values later, in elf_bfd_final_link, but we must add the entries
1360 now so that we know the final size of the .dynamic section. */
1361 if (elf_link_hash_lookup (elf_hash_table (info), "_init", false,
1362 false, false) != NULL)
1363 {
1364 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
1365 return false;
1366 }
1367 if (elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
1368 false, false) != NULL)
1369 {
1370 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
1371 return false;
1372 }
1373 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1374 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
1375 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
1376 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
1377 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
1378 || ! elf_add_dynamic_entry (info, DT_SYMENT,
1379 sizeof (Elf_External_Sym)))
1380 return false;
1381 }
1382
1383 /* The backend must work out the sizes of all the other dynamic
1384 sections. */
1385 bed = get_elf_backend_data (output_bfd);
1386 if (! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
1387 return false;
1388
1389 if (elf_hash_table (info)->dynamic_sections_created)
1390 {
1391 size_t dynsymcount;
1392 asection *s;
1393 size_t i;
1394 size_t bucketcount = 0;
1395 Elf_Internal_Sym isym;
1396
1397 /* Set the size of the .dynsym and .hash sections. We counted
1398 the number of dynamic symbols in elf_link_add_object_symbols.
1399 We will build the contents of .dynsym and .hash when we build
1400 the final symbol table, because until then we do not know the
1401 correct value to give the symbols. We built the .dynstr
1402 section as we went along in elf_link_add_object_symbols. */
1403 dynsymcount = elf_hash_table (info)->dynsymcount;
1404 s = bfd_get_section_by_name (dynobj, ".dynsym");
1405 BFD_ASSERT (s != NULL);
1406 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
1407 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
1408 if (s->contents == NULL && s->_raw_size != 0)
1409 {
1410 bfd_set_error (bfd_error_no_memory);
1411 return false;
1412 }
1413
1414 /* The first entry in .dynsym is a dummy symbol. */
1415 isym.st_value = 0;
1416 isym.st_size = 0;
1417 isym.st_name = 0;
1418 isym.st_info = 0;
1419 isym.st_other = 0;
1420 isym.st_shndx = 0;
1421 elf_swap_symbol_out (output_bfd, &isym,
1422 (PTR) (Elf_External_Sym *) s->contents);
1423
1424 for (i = 0; elf_buckets[i] != 0; i++)
1425 {
1426 bucketcount = elf_buckets[i];
1427 if (dynsymcount < elf_buckets[i + 1])
1428 break;
1429 }
1430
1431 s = bfd_get_section_by_name (dynobj, ".hash");
1432 BFD_ASSERT (s != NULL);
1433 s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
1434 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
1435 if (s->contents == NULL)
1436 {
1437 bfd_set_error (bfd_error_no_memory);
1438 return false;
1439 }
1440 memset (s->contents, 0, (size_t) s->_raw_size);
1441
1442 put_word (output_bfd, bucketcount, s->contents);
1443 put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
1444
1445 elf_hash_table (info)->bucketcount = bucketcount;
1446
1447 s = bfd_get_section_by_name (dynobj, ".dynstr");
1448 BFD_ASSERT (s != NULL);
1449 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1450
1451 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
1452 return false;
1453 }
1454
1455 return true;
1456 }
1457
1458 /* This routine is used to export all defined symbols into the dynamic
1459 symbol table. It is called via elf_link_hash_traverse. */
1460
1461 static boolean
1462 elf_export_symbol (h, data)
1463 struct elf_link_hash_entry *h;
1464 PTR data;
1465 {
1466 struct elf_info_failed *eif = (struct elf_info_failed *) data;
1467
1468 if (h->dynindx == -1
1469 && (h->elf_link_hash_flags
1470 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
1471 {
1472 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
1473 {
1474 eif->failed = true;
1475 return false;
1476 }
1477 }
1478
1479 return true;
1480 }
1481
1482 /* Make the backend pick a good value for a dynamic symbol. This is
1483 called via elf_link_hash_traverse, and also calls itself
1484 recursively. */
1485
1486 static boolean
1487 elf_adjust_dynamic_symbol (h, data)
1488 struct elf_link_hash_entry *h;
1489 PTR data;
1490 {
1491 struct elf_info_failed *eif = (struct elf_info_failed *) data;
1492 bfd *dynobj;
1493 struct elf_backend_data *bed;
1494
1495 /* If -Bsymbolic was used (which means to bind references to global
1496 symbols to the definition within the shared object), and this
1497 symbol was defined in a regular object, then it actually doesn't
1498 need a PLT entry. */
1499 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
1500 && eif->info->shared
1501 && eif->info->symbolic
1502 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
1503 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
1504
1505 /* If this symbol does not require a PLT entry, and it is not
1506 defined by a dynamic object, or is not referenced by a regular
1507 object, ignore it. We do have to handle a weak defined symbol,
1508 even if no regular object refers to it, if we decided to add it
1509 to the dynamic symbol table. FIXME: Do we normally need to worry
1510 about symbols which are defined by one dynamic object and
1511 referenced by another one? */
1512 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
1513 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
1514 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
1515 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
1516 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
1517 return true;
1518
1519 /* If we've already adjusted this symbol, don't do it again. This
1520 can happen via a recursive call. */
1521 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
1522 return true;
1523
1524 /* Don't look at this symbol again. Note that we must set this
1525 after checking the above conditions, because we may look at a
1526 symbol once, decide not to do anything, and then get called
1527 recursively later after REF_REGULAR is set below. */
1528 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
1529
1530 /* If this is a weak definition, and we know a real definition, and
1531 the real symbol is not itself defined by a regular object file,
1532 then get a good value for the real definition. We handle the
1533 real symbol first, for the convenience of the backend routine.
1534
1535 Note that there is a confusing case here. If the real definition
1536 is defined by a regular object file, we don't get the real symbol
1537 from the dynamic object, but we do get the weak symbol. If the
1538 processor backend uses a COPY reloc, then if some routine in the
1539 dynamic object changes the real symbol, we will not see that
1540 change in the corresponding weak symbol. This is the way other
1541 ELF linkers work as well, and seems to be a result of the shared
1542 library model.
1543
1544 I will clarify this issue. Most SVR4 shared libraries define the
1545 variable _timezone and define timezone as a weak synonym. The
1546 tzset call changes _timezone. If you write
1547 extern int timezone;
1548 int _timezone = 5;
1549 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
1550 you might expect that, since timezone is a synonym for _timezone,
1551 the same number will print both times. However, if the processor
1552 backend uses a COPY reloc, then actually timezone will be copied
1553 into your process image, and, since you define _timezone
1554 yourself, _timezone will not. Thus timezone and _timezone will
1555 wind up at different memory locations. The tzset call will set
1556 _timezone, leaving timezone unchanged. */
1557
1558 if (h->weakdef != NULL)
1559 {
1560 struct elf_link_hash_entry *weakdef;
1561
1562 BFD_ASSERT (h->root.type == bfd_link_hash_defined
1563 || h->root.type == bfd_link_hash_defweak);
1564 weakdef = h->weakdef;
1565 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
1566 || weakdef->root.type == bfd_link_hash_defweak);
1567 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
1568 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
1569 {
1570 /* This symbol is defined by a regular object file, so we
1571 will not do anything special. Clear weakdef for the
1572 convenience of the processor backend. */
1573 h->weakdef = NULL;
1574 }
1575 else
1576 {
1577 /* There is an implicit reference by a regular object file
1578 via the weak symbol. */
1579 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
1580 if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif))
1581 return false;
1582 }
1583 }
1584
1585 dynobj = elf_hash_table (eif->info)->dynobj;
1586 bed = get_elf_backend_data (dynobj);
1587 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
1588 {
1589 eif->failed = true;
1590 return false;
1591 }
1592
1593 return true;
1594 }
1595 \f
1596 /* Final phase of ELF linker. */
1597
1598 /* A structure we use to avoid passing large numbers of arguments. */
1599
1600 struct elf_final_link_info
1601 {
1602 /* General link information. */
1603 struct bfd_link_info *info;
1604 /* Output BFD. */
1605 bfd *output_bfd;
1606 /* Symbol string table. */
1607 struct bfd_strtab_hash *symstrtab;
1608 /* .dynsym section. */
1609 asection *dynsym_sec;
1610 /* .hash section. */
1611 asection *hash_sec;
1612 /* Buffer large enough to hold contents of any section. */
1613 bfd_byte *contents;
1614 /* Buffer large enough to hold external relocs of any section. */
1615 PTR external_relocs;
1616 /* Buffer large enough to hold internal relocs of any section. */
1617 Elf_Internal_Rela *internal_relocs;
1618 /* Buffer large enough to hold external local symbols of any input
1619 BFD. */
1620 Elf_External_Sym *external_syms;
1621 /* Buffer large enough to hold internal local symbols of any input
1622 BFD. */
1623 Elf_Internal_Sym *internal_syms;
1624 /* Array large enough to hold a symbol index for each local symbol
1625 of any input BFD. */
1626 long *indices;
1627 /* Array large enough to hold a section pointer for each local
1628 symbol of any input BFD. */
1629 asection **sections;
1630 /* Buffer to hold swapped out symbols. */
1631 Elf_External_Sym *symbuf;
1632 /* Number of swapped out symbols in buffer. */
1633 size_t symbuf_count;
1634 /* Number of symbols which fit in symbuf. */
1635 size_t symbuf_size;
1636 };
1637
1638 static boolean elf_link_output_sym
1639 PARAMS ((struct elf_final_link_info *, const char *,
1640 Elf_Internal_Sym *, asection *));
1641 static boolean elf_link_flush_output_syms
1642 PARAMS ((struct elf_final_link_info *));
1643 static boolean elf_link_output_extsym
1644 PARAMS ((struct elf_link_hash_entry *, PTR));
1645 static boolean elf_link_input_bfd
1646 PARAMS ((struct elf_final_link_info *, bfd *));
1647 static boolean elf_reloc_link_order
1648 PARAMS ((bfd *, struct bfd_link_info *, asection *,
1649 struct bfd_link_order *));
1650
1651 /* This struct is used to pass information to routines called via
1652 elf_link_hash_traverse which must return failure. */
1653
1654 struct elf_finfo_failed
1655 {
1656 boolean failed;
1657 struct elf_final_link_info *finfo;
1658 };
1659
1660 /* Do the final step of an ELF link. */
1661
1662 boolean
1663 elf_bfd_final_link (abfd, info)
1664 bfd *abfd;
1665 struct bfd_link_info *info;
1666 {
1667 boolean dynamic;
1668 bfd *dynobj;
1669 struct elf_final_link_info finfo;
1670 register asection *o;
1671 register struct bfd_link_order *p;
1672 register bfd *sub;
1673 size_t max_contents_size;
1674 size_t max_external_reloc_size;
1675 size_t max_internal_reloc_count;
1676 size_t max_sym_count;
1677 file_ptr off;
1678 Elf_Internal_Sym elfsym;
1679 unsigned int i;
1680 Elf_Internal_Shdr *symtab_hdr;
1681 Elf_Internal_Shdr *symstrtab_hdr;
1682 struct elf_backend_data *bed = get_elf_backend_data (abfd);
1683 struct elf_finfo_failed eif;
1684
1685 if (info->shared)
1686 abfd->flags |= DYNAMIC;
1687
1688 dynamic = elf_hash_table (info)->dynamic_sections_created;
1689 dynobj = elf_hash_table (info)->dynobj;
1690
1691 finfo.info = info;
1692 finfo.output_bfd = abfd;
1693 finfo.symstrtab = elf_stringtab_init ();
1694 if (finfo.symstrtab == NULL)
1695 return false;
1696 if (! dynamic)
1697 {
1698 finfo.dynsym_sec = NULL;
1699 finfo.hash_sec = NULL;
1700 }
1701 else
1702 {
1703 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
1704 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
1705 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
1706 }
1707 finfo.contents = NULL;
1708 finfo.external_relocs = NULL;
1709 finfo.internal_relocs = NULL;
1710 finfo.external_syms = NULL;
1711 finfo.internal_syms = NULL;
1712 finfo.indices = NULL;
1713 finfo.sections = NULL;
1714 finfo.symbuf = NULL;
1715 finfo.symbuf_count = 0;
1716
1717 /* Count up the number of relocations we will output for each output
1718 section, so that we know the sizes of the reloc sections. We
1719 also figure out some maximum sizes. */
1720 max_contents_size = 0;
1721 max_external_reloc_size = 0;
1722 max_internal_reloc_count = 0;
1723 max_sym_count = 0;
1724 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
1725 {
1726 o->reloc_count = 0;
1727
1728 for (p = o->link_order_head; p != NULL; p = p->next)
1729 {
1730 if (p->type == bfd_section_reloc_link_order
1731 || p->type == bfd_symbol_reloc_link_order)
1732 ++o->reloc_count;
1733 else if (p->type == bfd_indirect_link_order)
1734 {
1735 asection *sec;
1736
1737 sec = p->u.indirect.section;
1738
1739 if (info->relocateable)
1740 o->reloc_count += sec->reloc_count;
1741
1742 if (sec->_raw_size > max_contents_size)
1743 max_contents_size = sec->_raw_size;
1744 if (sec->_cooked_size > max_contents_size)
1745 max_contents_size = sec->_cooked_size;
1746
1747 /* We are interested in just local symbols, not all
1748 symbols. */
1749 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour)
1750 {
1751 size_t sym_count;
1752
1753 if (elf_bad_symtab (sec->owner))
1754 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
1755 / sizeof (Elf_External_Sym));
1756 else
1757 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
1758
1759 if (sym_count > max_sym_count)
1760 max_sym_count = sym_count;
1761
1762 if ((sec->flags & SEC_RELOC) != 0)
1763 {
1764 size_t ext_size;
1765
1766 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
1767 if (ext_size > max_external_reloc_size)
1768 max_external_reloc_size = ext_size;
1769 if (sec->reloc_count > max_internal_reloc_count)
1770 max_internal_reloc_count = sec->reloc_count;
1771 }
1772 }
1773 }
1774 }
1775
1776 if (o->reloc_count > 0)
1777 o->flags |= SEC_RELOC;
1778 else
1779 {
1780 /* Explicitly clear the SEC_RELOC flag. The linker tends to
1781 set it (this is probably a bug) and if it is set
1782 assign_section_numbers will create a reloc section. */
1783 o->flags &=~ SEC_RELOC;
1784 }
1785
1786 /* If the SEC_ALLOC flag is not set, force the section VMA to
1787 zero. This is done in elf_fake_sections as well, but forcing
1788 the VMA to 0 here will ensure that relocs against these
1789 sections are handled correctly. */
1790 if ((o->flags & SEC_ALLOC) == 0)
1791 o->vma = 0;
1792 }
1793
1794 /* Figure out the file positions for everything but the symbol table
1795 and the relocs. We set symcount to force assign_section_numbers
1796 to create a symbol table. */
1797 abfd->symcount = info->strip == strip_all ? 0 : 1;
1798 BFD_ASSERT (! abfd->output_has_begun);
1799 if (! _bfd_elf_compute_section_file_positions (abfd, info))
1800 goto error_return;
1801
1802 /* That created the reloc sections. Set their sizes, and assign
1803 them file positions, and allocate some buffers. */
1804 for (o = abfd->sections; o != NULL; o = o->next)
1805 {
1806 if ((o->flags & SEC_RELOC) != 0)
1807 {
1808 Elf_Internal_Shdr *rel_hdr;
1809 register struct elf_link_hash_entry **p, **pend;
1810
1811 rel_hdr = &elf_section_data (o)->rel_hdr;
1812
1813 rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
1814
1815 /* The contents field must last into write_object_contents,
1816 so we allocate it with bfd_alloc rather than malloc. */
1817 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
1818 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
1819 {
1820 bfd_set_error (bfd_error_no_memory);
1821 goto error_return;
1822 }
1823
1824 p = ((struct elf_link_hash_entry **)
1825 malloc (o->reloc_count
1826 * sizeof (struct elf_link_hash_entry *)));
1827 if (p == NULL && o->reloc_count != 0)
1828 {
1829 bfd_set_error (bfd_error_no_memory);
1830 goto error_return;
1831 }
1832 elf_section_data (o)->rel_hashes = p;
1833 pend = p + o->reloc_count;
1834 for (; p < pend; p++)
1835 *p = NULL;
1836
1837 /* Use the reloc_count field as an index when outputting the
1838 relocs. */
1839 o->reloc_count = 0;
1840 }
1841 }
1842
1843 _bfd_elf_assign_file_positions_for_relocs (abfd);
1844
1845 /* We have now assigned file positions for all the sections except
1846 .symtab and .strtab. We start the .symtab section at the current
1847 file position, and write directly to it. We build the .strtab
1848 section in memory. When we add .dynsym support, we will build
1849 that in memory as well (.dynsym is smaller than .symtab). */
1850 abfd->symcount = 0;
1851 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1852 /* sh_name is set in prep_headers. */
1853 symtab_hdr->sh_type = SHT_SYMTAB;
1854 symtab_hdr->sh_flags = 0;
1855 symtab_hdr->sh_addr = 0;
1856 symtab_hdr->sh_size = 0;
1857 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
1858 /* sh_link is set in assign_section_numbers. */
1859 /* sh_info is set below. */
1860 /* sh_offset is set just below. */
1861 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
1862
1863 off = elf_tdata (abfd)->next_file_pos;
1864 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
1865
1866 /* Note that at this point elf_tdata (abfd)->next_file_pos is
1867 incorrect. We do not yet know the size of the .symtab section.
1868 We correct next_file_pos below, after we do know the size. */
1869
1870 /* Allocate a buffer to hold swapped out symbols. This is to avoid
1871 continuously seeking to the right position in the file. */
1872 if (! info->keep_memory || max_sym_count < 20)
1873 finfo.symbuf_size = 20;
1874 else
1875 finfo.symbuf_size = max_sym_count;
1876 finfo.symbuf = ((Elf_External_Sym *)
1877 malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
1878 if (finfo.symbuf == NULL)
1879 {
1880 bfd_set_error (bfd_error_no_memory);
1881 goto error_return;
1882 }
1883
1884 /* Start writing out the symbol table. The first symbol is always a
1885 dummy symbol. */
1886 elfsym.st_value = 0;
1887 elfsym.st_size = 0;
1888 elfsym.st_info = 0;
1889 elfsym.st_other = 0;
1890 elfsym.st_shndx = SHN_UNDEF;
1891 if (! elf_link_output_sym (&finfo, (const char *) NULL,
1892 &elfsym, bfd_und_section_ptr))
1893 goto error_return;
1894
1895 #if 0
1896 /* Some standard ELF linkers do this, but we don't because it causes
1897 bootstrap comparison failures. */
1898 /* Output a file symbol for the output file as the second symbol.
1899 We output this even if we are discarding local symbols, although
1900 I'm not sure if this is correct. */
1901 elfsym.st_value = 0;
1902 elfsym.st_size = 0;
1903 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
1904 elfsym.st_other = 0;
1905 elfsym.st_shndx = SHN_ABS;
1906 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
1907 &elfsym, bfd_abs_section_ptr))
1908 goto error_return;
1909 #endif
1910
1911 /* Output a symbol for each section. We output these even if we are
1912 discarding local symbols, since they are used for relocs. These
1913 symbols have no names. We store the index of each one in the
1914 index field of the section, so that we can find it again when
1915 outputting relocs. */
1916 elfsym.st_value = 0;
1917 elfsym.st_size = 0;
1918 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
1919 elfsym.st_other = 0;
1920 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
1921 {
1922 o = section_from_elf_index (abfd, i);
1923 if (o != NULL)
1924 o->target_index = abfd->symcount;
1925 elfsym.st_shndx = i;
1926 if (! elf_link_output_sym (&finfo, (const char *) NULL,
1927 &elfsym, o))
1928 goto error_return;
1929 }
1930
1931 /* Allocate some memory to hold information read in from the input
1932 files. */
1933 finfo.contents = (bfd_byte *) malloc (max_contents_size);
1934 finfo.external_relocs = (PTR) malloc (max_external_reloc_size);
1935 finfo.internal_relocs = ((Elf_Internal_Rela *)
1936 malloc (max_internal_reloc_count
1937 * sizeof (Elf_Internal_Rela)));
1938 finfo.external_syms = ((Elf_External_Sym *)
1939 malloc (max_sym_count * sizeof (Elf_External_Sym)));
1940 finfo.internal_syms = ((Elf_Internal_Sym *)
1941 malloc (max_sym_count * sizeof (Elf_Internal_Sym)));
1942 finfo.indices = (long *) malloc (max_sym_count * sizeof (long));
1943 finfo.sections = (asection **) malloc (max_sym_count * sizeof (asection *));
1944 if ((finfo.contents == NULL && max_contents_size != 0)
1945 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
1946 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
1947 || (finfo.external_syms == NULL && max_sym_count != 0)
1948 || (finfo.internal_syms == NULL && max_sym_count != 0)
1949 || (finfo.indices == NULL && max_sym_count != 0)
1950 || (finfo.sections == NULL && max_sym_count != 0))
1951 {
1952 bfd_set_error (bfd_error_no_memory);
1953 goto error_return;
1954 }
1955
1956 /* Since ELF permits relocations to be against local symbols, we
1957 must have the local symbols available when we do the relocations.
1958 Since we would rather only read the local symbols once, and we
1959 would rather not keep them in memory, we handle all the
1960 relocations for a single input file at the same time.
1961
1962 Unfortunately, there is no way to know the total number of local
1963 symbols until we have seen all of them, and the local symbol
1964 indices precede the global symbol indices. This means that when
1965 we are generating relocateable output, and we see a reloc against
1966 a global symbol, we can not know the symbol index until we have
1967 finished examining all the local symbols to see which ones we are
1968 going to output. To deal with this, we keep the relocations in
1969 memory, and don't output them until the end of the link. This is
1970 an unfortunate waste of memory, but I don't see a good way around
1971 it. Fortunately, it only happens when performing a relocateable
1972 link, which is not the common case. FIXME: If keep_memory is set
1973 we could write the relocs out and then read them again; I don't
1974 know how bad the memory loss will be. */
1975
1976 for (sub = info->input_bfds; sub != NULL; sub = sub->next)
1977 sub->output_has_begun = false;
1978 for (o = abfd->sections; o != NULL; o = o->next)
1979 {
1980 for (p = o->link_order_head; p != NULL; p = p->next)
1981 {
1982 if (p->type == bfd_indirect_link_order
1983 && (bfd_get_flavour (p->u.indirect.section->owner)
1984 == bfd_target_elf_flavour))
1985 {
1986 sub = p->u.indirect.section->owner;
1987 if (! sub->output_has_begun)
1988 {
1989 if (! elf_link_input_bfd (&finfo, sub))
1990 goto error_return;
1991 sub->output_has_begun = true;
1992 }
1993 }
1994 else if (p->type == bfd_section_reloc_link_order
1995 || p->type == bfd_symbol_reloc_link_order)
1996 {
1997 if (! elf_reloc_link_order (abfd, info, o, p))
1998 goto error_return;
1999 }
2000 else
2001 {
2002 if (! _bfd_default_link_order (abfd, info, o, p))
2003 goto error_return;
2004 }
2005 }
2006 }
2007
2008 /* That wrote out all the local symbols. Finish up the symbol table
2009 with the global symbols. */
2010
2011 /* The sh_info field records the index of the first non local
2012 symbol. */
2013 symtab_hdr->sh_info = abfd->symcount;
2014 if (dynamic)
2015 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1;
2016
2017 /* We get the global symbols from the hash table. */
2018 eif.failed = false;
2019 eif.finfo = &finfo;
2020 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
2021 (PTR) &eif);
2022 if (eif.failed)
2023 return false;
2024
2025 /* Flush all symbols to the file. */
2026 if (! elf_link_flush_output_syms (&finfo))
2027 return false;
2028
2029 /* Now we know the size of the symtab section. */
2030 off += symtab_hdr->sh_size;
2031
2032 /* Finish up and write out the symbol string table (.strtab)
2033 section. */
2034 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
2035 /* sh_name was set in prep_headers. */
2036 symstrtab_hdr->sh_type = SHT_STRTAB;
2037 symstrtab_hdr->sh_flags = 0;
2038 symstrtab_hdr->sh_addr = 0;
2039 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
2040 symstrtab_hdr->sh_entsize = 0;
2041 symstrtab_hdr->sh_link = 0;
2042 symstrtab_hdr->sh_info = 0;
2043 /* sh_offset is set just below. */
2044 symstrtab_hdr->sh_addralign = 1;
2045
2046 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
2047 elf_tdata (abfd)->next_file_pos = off;
2048
2049 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
2050 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
2051 return false;
2052
2053 /* Adjust the relocs to have the correct symbol indices. */
2054 for (o = abfd->sections; o != NULL; o = o->next)
2055 {
2056 struct elf_link_hash_entry **rel_hash;
2057 Elf_Internal_Shdr *rel_hdr;
2058
2059 if ((o->flags & SEC_RELOC) == 0)
2060 continue;
2061
2062 rel_hash = elf_section_data (o)->rel_hashes;
2063 rel_hdr = &elf_section_data (o)->rel_hdr;
2064 for (i = 0; i < o->reloc_count; i++, rel_hash++)
2065 {
2066 if (*rel_hash == NULL)
2067 continue;
2068
2069 BFD_ASSERT ((*rel_hash)->indx >= 0);
2070
2071 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
2072 {
2073 Elf_External_Rel *erel;
2074 Elf_Internal_Rel irel;
2075
2076 erel = (Elf_External_Rel *) rel_hdr->contents + i;
2077 elf_swap_reloc_in (abfd, erel, &irel);
2078 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
2079 ELF_R_TYPE (irel.r_info));
2080 elf_swap_reloc_out (abfd, &irel, erel);
2081 }
2082 else
2083 {
2084 Elf_External_Rela *erela;
2085 Elf_Internal_Rela irela;
2086
2087 BFD_ASSERT (rel_hdr->sh_entsize
2088 == sizeof (Elf_External_Rela));
2089
2090 erela = (Elf_External_Rela *) rel_hdr->contents + i;
2091 elf_swap_reloca_in (abfd, erela, &irela);
2092 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
2093 ELF_R_TYPE (irela.r_info));
2094 elf_swap_reloca_out (abfd, &irela, erela);
2095 }
2096 }
2097
2098 /* Set the reloc_count field to 0 to prevent write_relocs from
2099 trying to swap the relocs out itself. */
2100 o->reloc_count = 0;
2101 }
2102
2103 /* If we are linking against a dynamic object, or generating a
2104 shared library, finish up the dynamic linking information. */
2105 if (dynamic)
2106 {
2107 Elf_External_Dyn *dyncon, *dynconend;
2108
2109 /* Fix up .dynamic entries. */
2110 o = bfd_get_section_by_name (dynobj, ".dynamic");
2111 BFD_ASSERT (o != NULL);
2112
2113 dyncon = (Elf_External_Dyn *) o->contents;
2114 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
2115 for (; dyncon < dynconend; dyncon++)
2116 {
2117 Elf_Internal_Dyn dyn;
2118 const char *name;
2119 unsigned int type;
2120
2121 elf_swap_dyn_in (dynobj, dyncon, &dyn);
2122
2123 switch (dyn.d_tag)
2124 {
2125 default:
2126 break;
2127
2128 /* SVR4 linkers seem to set DT_INIT and DT_FINI based on
2129 magic _init and _fini symbols. This is pretty ugly,
2130 but we are compatible. */
2131 case DT_INIT:
2132 name = "_init";
2133 goto get_sym;
2134 case DT_FINI:
2135 name = "_fini";
2136 get_sym:
2137 {
2138 struct elf_link_hash_entry *h;
2139
2140 h = elf_link_hash_lookup (elf_hash_table (info), name,
2141 false, false, true);
2142 if (h != NULL
2143 && (h->root.type == bfd_link_hash_defined
2144 || h->root.type == bfd_link_hash_defweak))
2145 {
2146 dyn.d_un.d_val = h->root.u.def.value;
2147 o = h->root.u.def.section;
2148 if (o->output_section != NULL)
2149 dyn.d_un.d_val += (o->output_section->vma
2150 + o->output_offset);
2151 else
2152 {
2153 /* The symbol is imported from another shared
2154 library and does not apply to this one. */
2155 dyn.d_un.d_val = 0;
2156 }
2157
2158 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2159 }
2160 }
2161 break;
2162
2163 case DT_HASH:
2164 name = ".hash";
2165 goto get_vma;
2166 case DT_STRTAB:
2167 name = ".dynstr";
2168 goto get_vma;
2169 case DT_SYMTAB:
2170 name = ".dynsym";
2171 get_vma:
2172 o = bfd_get_section_by_name (abfd, name);
2173 BFD_ASSERT (o != NULL);
2174 dyn.d_un.d_ptr = o->vma;
2175 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2176 break;
2177
2178 case DT_REL:
2179 case DT_RELA:
2180 case DT_RELSZ:
2181 case DT_RELASZ:
2182 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
2183 type = SHT_REL;
2184 else
2185 type = SHT_RELA;
2186 dyn.d_un.d_val = 0;
2187 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
2188 {
2189 Elf_Internal_Shdr *hdr;
2190
2191 hdr = elf_elfsections (abfd)[i];
2192 if (hdr->sh_type == type
2193 && (hdr->sh_flags & SHF_ALLOC) != 0)
2194 {
2195 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
2196 dyn.d_un.d_val += hdr->sh_size;
2197 else
2198 {
2199 if (dyn.d_un.d_val == 0
2200 || hdr->sh_addr < dyn.d_un.d_val)
2201 dyn.d_un.d_val = hdr->sh_addr;
2202 }
2203 }
2204 }
2205 elf_swap_dyn_out (dynobj, &dyn, dyncon);
2206 break;
2207 }
2208 }
2209 }
2210
2211 /* If we have created any dynamic sections, then output them. */
2212 if (dynobj != NULL)
2213 {
2214 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
2215 goto error_return;
2216
2217 for (o = dynobj->sections; o != NULL; o = o->next)
2218 {
2219 if ((o->flags & SEC_HAS_CONTENTS) == 0
2220 || o->_raw_size == 0)
2221 continue;
2222 if ((o->flags & SEC_IN_MEMORY) == 0)
2223 {
2224 /* At this point, we are only interested in sections
2225 created by elf_link_create_dynamic_sections. FIXME:
2226 This test is fragile. */
2227 continue;
2228 }
2229 if ((elf_section_data (o->output_section)->this_hdr.sh_type
2230 != SHT_STRTAB)
2231 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
2232 {
2233 if (! bfd_set_section_contents (abfd, o->output_section,
2234 o->contents, o->output_offset,
2235 o->_raw_size))
2236 goto error_return;
2237 }
2238 else
2239 {
2240 file_ptr off;
2241
2242 /* The contents of the .dynstr section are actually in a
2243 stringtab. */
2244 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
2245 if (bfd_seek (abfd, off, SEEK_SET) != 0
2246 || ! _bfd_stringtab_emit (abfd,
2247 elf_hash_table (info)->dynstr))
2248 goto error_return;
2249 }
2250 }
2251 }
2252
2253 if (finfo.symstrtab != NULL)
2254 _bfd_stringtab_free (finfo.symstrtab);
2255 if (finfo.contents != NULL)
2256 free (finfo.contents);
2257 if (finfo.external_relocs != NULL)
2258 free (finfo.external_relocs);
2259 if (finfo.internal_relocs != NULL)
2260 free (finfo.internal_relocs);
2261 if (finfo.external_syms != NULL)
2262 free (finfo.external_syms);
2263 if (finfo.internal_syms != NULL)
2264 free (finfo.internal_syms);
2265 if (finfo.indices != NULL)
2266 free (finfo.indices);
2267 if (finfo.sections != NULL)
2268 free (finfo.sections);
2269 if (finfo.symbuf != NULL)
2270 free (finfo.symbuf);
2271 for (o = abfd->sections; o != NULL; o = o->next)
2272 {
2273 if ((o->flags & SEC_RELOC) != 0
2274 && elf_section_data (o)->rel_hashes != NULL)
2275 free (elf_section_data (o)->rel_hashes);
2276 }
2277
2278 elf_tdata (abfd)->linker = true;
2279
2280 return true;
2281
2282 error_return:
2283 if (finfo.symstrtab != NULL)
2284 _bfd_stringtab_free (finfo.symstrtab);
2285 if (finfo.contents != NULL)
2286 free (finfo.contents);
2287 if (finfo.external_relocs != NULL)
2288 free (finfo.external_relocs);
2289 if (finfo.internal_relocs != NULL)
2290 free (finfo.internal_relocs);
2291 if (finfo.external_syms != NULL)
2292 free (finfo.external_syms);
2293 if (finfo.internal_syms != NULL)
2294 free (finfo.internal_syms);
2295 if (finfo.indices != NULL)
2296 free (finfo.indices);
2297 if (finfo.sections != NULL)
2298 free (finfo.sections);
2299 if (finfo.symbuf != NULL)
2300 free (finfo.symbuf);
2301 for (o = abfd->sections; o != NULL; o = o->next)
2302 {
2303 if ((o->flags & SEC_RELOC) != 0
2304 && elf_section_data (o)->rel_hashes != NULL)
2305 free (elf_section_data (o)->rel_hashes);
2306 }
2307
2308 return false;
2309 }
2310
2311 /* Add a symbol to the output symbol table. */
2312
2313 static boolean
2314 elf_link_output_sym (finfo, name, elfsym, input_sec)
2315 struct elf_final_link_info *finfo;
2316 const char *name;
2317 Elf_Internal_Sym *elfsym;
2318 asection *input_sec;
2319 {
2320 boolean (*output_symbol_hook) PARAMS ((bfd *,
2321 struct bfd_link_info *info,
2322 const char *,
2323 Elf_Internal_Sym *,
2324 asection *));
2325
2326 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
2327 elf_backend_link_output_symbol_hook;
2328 if (output_symbol_hook != NULL)
2329 {
2330 if (! ((*output_symbol_hook)
2331 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
2332 return false;
2333 }
2334
2335 if (name == (const char *) NULL || *name == '\0')
2336 elfsym->st_name = 0;
2337 else
2338 {
2339 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
2340 name, true,
2341 false);
2342 if (elfsym->st_name == (unsigned long) -1)
2343 return false;
2344 }
2345
2346 if (finfo->symbuf_count >= finfo->symbuf_size)
2347 {
2348 if (! elf_link_flush_output_syms (finfo))
2349 return false;
2350 }
2351
2352 elf_swap_symbol_out (finfo->output_bfd, elfsym,
2353 (PTR) (finfo->symbuf + finfo->symbuf_count));
2354 ++finfo->symbuf_count;
2355
2356 ++finfo->output_bfd->symcount;
2357
2358 return true;
2359 }
2360
2361 /* Flush the output symbols to the file. */
2362
2363 static boolean
2364 elf_link_flush_output_syms (finfo)
2365 struct elf_final_link_info *finfo;
2366 {
2367 Elf_Internal_Shdr *symtab;
2368
2369 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
2370
2371 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
2372 SEEK_SET) != 0
2373 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
2374 sizeof (Elf_External_Sym), finfo->output_bfd)
2375 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
2376 return false;
2377
2378 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
2379
2380 finfo->symbuf_count = 0;
2381
2382 return true;
2383 }
2384
2385 /* Add an external symbol to the symbol table. This is called from
2386 the hash table traversal routine. */
2387
2388 static boolean
2389 elf_link_output_extsym (h, data)
2390 struct elf_link_hash_entry *h;
2391 PTR data;
2392 {
2393 struct elf_finfo_failed *eif = (struct elf_finfo_failed *) data;
2394 struct elf_final_link_info *finfo = eif->finfo;
2395 boolean strip;
2396 Elf_Internal_Sym sym;
2397 asection *input_sec;
2398
2399 /* If we are not creating a shared library, and this symbol is
2400 referenced by a shared library but is not defined anywhere, then
2401 warn that it is undefined. If we do not do this, the runtime
2402 linker will complain that the symbol is undefined when the
2403 program is run. We don't have to worry about symbols that are
2404 referenced by regular files, because we will already have issued
2405 warnings for them. */
2406 if (! finfo->info->relocateable
2407 && ! finfo->info->shared
2408 && h->root.type == bfd_link_hash_undefined
2409 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
2410 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
2411 {
2412 if (! ((*finfo->info->callbacks->undefined_symbol)
2413 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
2414 (asection *) NULL, 0)))
2415 {
2416 eif->failed = true;
2417 return false;
2418 }
2419 }
2420
2421 /* We don't want to output symbols that have never been mentioned by
2422 a regular file, or that we have been told to strip. However, if
2423 h->indx is set to -2, the symbol is used by a reloc and we must
2424 output it. */
2425 if (h->indx == -2)
2426 strip = false;
2427 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2428 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
2429 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
2430 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
2431 strip = true;
2432 else if (finfo->info->strip == strip_all
2433 || (finfo->info->strip == strip_some
2434 && bfd_hash_lookup (finfo->info->keep_hash,
2435 h->root.root.string,
2436 false, false) == NULL))
2437 strip = true;
2438 else
2439 strip = false;
2440
2441 /* If we're stripping it, and it's not a dynamic symbol, there's
2442 nothing else to do. */
2443 if (strip && h->dynindx == -1)
2444 return true;
2445
2446 sym.st_value = 0;
2447 sym.st_size = h->size;
2448 sym.st_other = 0;
2449 if (h->root.type == bfd_link_hash_undefweak
2450 || h->root.type == bfd_link_hash_defweak)
2451 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
2452 else
2453 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
2454
2455 switch (h->root.type)
2456 {
2457 default:
2458 case bfd_link_hash_new:
2459 abort ();
2460 return false;
2461
2462 case bfd_link_hash_undefined:
2463 input_sec = bfd_und_section_ptr;
2464 sym.st_shndx = SHN_UNDEF;
2465 break;
2466
2467 case bfd_link_hash_undefweak:
2468 input_sec = bfd_und_section_ptr;
2469 sym.st_shndx = SHN_UNDEF;
2470 break;
2471
2472 case bfd_link_hash_defined:
2473 case bfd_link_hash_defweak:
2474 {
2475 input_sec = h->root.u.def.section;
2476 if (input_sec->output_section != NULL)
2477 {
2478 sym.st_shndx =
2479 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
2480 input_sec->output_section);
2481 if (sym.st_shndx == (unsigned short) -1)
2482 {
2483 eif->failed = true;
2484 return false;
2485 }
2486
2487 /* ELF symbols in relocateable files are section relative,
2488 but in nonrelocateable files they are virtual
2489 addresses. */
2490 sym.st_value = h->root.u.def.value + input_sec->output_offset;
2491 if (! finfo->info->relocateable)
2492 sym.st_value += input_sec->output_section->vma;
2493 }
2494 else
2495 {
2496 BFD_ASSERT ((bfd_get_flavour (input_sec->owner)
2497 == bfd_target_elf_flavour)
2498 && elf_elfheader (input_sec->owner)->e_type == ET_DYN);
2499 sym.st_shndx = SHN_UNDEF;
2500 input_sec = bfd_und_section_ptr;
2501 }
2502 }
2503 break;
2504
2505 case bfd_link_hash_common:
2506 input_sec = bfd_com_section_ptr;
2507 sym.st_shndx = SHN_COMMON;
2508 sym.st_value = 1 << h->root.u.c.p->alignment_power;
2509 break;
2510
2511 case bfd_link_hash_indirect:
2512 case bfd_link_hash_warning:
2513 return (elf_link_output_extsym
2514 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
2515 }
2516
2517 /* If this symbol should be put in the .dynsym section, then put it
2518 there now. We have already know the symbol index. We also fill
2519 in the entry in the .hash section. */
2520 if (h->dynindx != -1
2521 && elf_hash_table (finfo->info)->dynamic_sections_created)
2522 {
2523 struct elf_backend_data *bed;
2524 size_t bucketcount;
2525 size_t bucket;
2526 bfd_byte *bucketpos;
2527 bfd_vma chain;
2528
2529 sym.st_name = h->dynstr_index;
2530
2531 /* Give the processor backend a chance to tweak the symbol
2532 value, and also to finish up anything that needs to be done
2533 for this symbol. */
2534 bed = get_elf_backend_data (finfo->output_bfd);
2535 if (! ((*bed->elf_backend_finish_dynamic_symbol)
2536 (finfo->output_bfd, finfo->info, h, &sym)))
2537 {
2538 eif->failed = true;
2539 return false;
2540 }
2541
2542 elf_swap_symbol_out (finfo->output_bfd, &sym,
2543 (PTR) (((Elf_External_Sym *)
2544 finfo->dynsym_sec->contents)
2545 + h->dynindx));
2546
2547 bucketcount = elf_hash_table (finfo->info)->bucketcount;
2548 bucket = (bfd_elf_hash ((const unsigned char *) h->root.root.string)
2549 % bucketcount);
2550 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
2551 + (bucket + 2) * (ARCH_SIZE / 8));
2552 chain = get_word (finfo->output_bfd, bucketpos);
2553 put_word (finfo->output_bfd, h->dynindx, bucketpos);
2554 put_word (finfo->output_bfd, chain,
2555 ((bfd_byte *) finfo->hash_sec->contents
2556 + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
2557 }
2558
2559 /* If we're stripping it, then it was just a dynamic symbol, and
2560 there's nothing else to do. */
2561 if (strip)
2562 return true;
2563
2564 h->indx = finfo->output_bfd->symcount;
2565
2566 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
2567 {
2568 eif->failed = true;
2569 return false;
2570 }
2571
2572 return true;
2573 }
2574
2575 /* Link an input file into the linker output file. This function
2576 handles all the sections and relocations of the input file at once.
2577 This is so that we only have to read the local symbols once, and
2578 don't have to keep them in memory. */
2579
2580 static boolean
2581 elf_link_input_bfd (finfo, input_bfd)
2582 struct elf_final_link_info *finfo;
2583 bfd *input_bfd;
2584 {
2585 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
2586 bfd *, asection *, bfd_byte *,
2587 Elf_Internal_Rela *,
2588 Elf_Internal_Sym *, asection **));
2589 bfd *output_bfd;
2590 Elf_Internal_Shdr *symtab_hdr;
2591 size_t locsymcount;
2592 size_t extsymoff;
2593 Elf_External_Sym *esym;
2594 Elf_External_Sym *esymend;
2595 Elf_Internal_Sym *isym;
2596 long *pindex;
2597 asection **ppsection;
2598 asection *o;
2599
2600 output_bfd = finfo->output_bfd;
2601 relocate_section =
2602 get_elf_backend_data (output_bfd)->elf_backend_relocate_section;
2603
2604 /* If this is a dynamic object, we don't want to do anything here:
2605 we don't want the local symbols, and we don't want the section
2606 contents. */
2607 if (elf_elfheader (input_bfd)->e_type == ET_DYN)
2608 return true;
2609
2610 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
2611 if (elf_bad_symtab (input_bfd))
2612 {
2613 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
2614 extsymoff = 0;
2615 }
2616 else
2617 {
2618 locsymcount = symtab_hdr->sh_info;
2619 extsymoff = symtab_hdr->sh_info;
2620 }
2621
2622 /* Read the local symbols. */
2623 if (locsymcount > 0
2624 && (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
2625 || (bfd_read (finfo->external_syms, sizeof (Elf_External_Sym),
2626 locsymcount, input_bfd)
2627 != locsymcount * sizeof (Elf_External_Sym))))
2628 return false;
2629
2630 /* Swap in the local symbols and write out the ones which we know
2631 are going into the output file. */
2632 esym = finfo->external_syms;
2633 esymend = esym + locsymcount;
2634 isym = finfo->internal_syms;
2635 pindex = finfo->indices;
2636 ppsection = finfo->sections;
2637 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
2638 {
2639 asection *isec;
2640 const char *name;
2641 Elf_Internal_Sym osym;
2642
2643 elf_swap_symbol_in (input_bfd, esym, isym);
2644 *pindex = -1;
2645
2646 if (elf_bad_symtab (input_bfd))
2647 {
2648 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
2649 {
2650 *ppsection = NULL;
2651 continue;
2652 }
2653 }
2654
2655 if (isym->st_shndx == SHN_UNDEF)
2656 isec = bfd_und_section_ptr;
2657 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
2658 isec = section_from_elf_index (input_bfd, isym->st_shndx);
2659 else if (isym->st_shndx == SHN_ABS)
2660 isec = bfd_abs_section_ptr;
2661 else if (isym->st_shndx == SHN_COMMON)
2662 isec = bfd_com_section_ptr;
2663 else
2664 {
2665 /* Who knows? */
2666 isec = NULL;
2667 }
2668
2669 *ppsection = isec;
2670
2671 /* Don't output the first, undefined, symbol. */
2672 if (esym == finfo->external_syms)
2673 continue;
2674
2675 /* If we are stripping all symbols, we don't want to output this
2676 one. */
2677 if (finfo->info->strip == strip_all)
2678 continue;
2679
2680 /* We never output section symbols. Instead, we use the section
2681 symbol of the corresponding section in the output file. */
2682 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
2683 continue;
2684
2685 /* If we are discarding all local symbols, we don't want to
2686 output this one. If we are generating a relocateable output
2687 file, then some of the local symbols may be required by
2688 relocs; we output them below as we discover that they are
2689 needed. */
2690 if (finfo->info->discard == discard_all)
2691 continue;
2692
2693 /* Get the name of the symbol. */
2694 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
2695 isym->st_name);
2696 if (name == NULL)
2697 return false;
2698
2699 /* See if we are discarding symbols with this name. */
2700 if ((finfo->info->strip == strip_some
2701 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
2702 == NULL))
2703 || (finfo->info->discard == discard_l
2704 && strncmp (name, finfo->info->lprefix,
2705 finfo->info->lprefix_len) == 0))
2706 continue;
2707
2708 /* If we get here, we are going to output this symbol. */
2709
2710 osym = *isym;
2711
2712 /* Adjust the section index for the output file. */
2713 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
2714 isec->output_section);
2715 if (osym.st_shndx == (unsigned short) -1)
2716 return false;
2717
2718 *pindex = output_bfd->symcount;
2719
2720 /* ELF symbols in relocateable files are section relative, but
2721 in executable files they are virtual addresses. Note that
2722 this code assumes that all ELF sections have an associated
2723 BFD section with a reasonable value for output_offset; below
2724 we assume that they also have a reasonable value for
2725 output_section. Any special sections must be set up to meet
2726 these requirements. */
2727 osym.st_value += isec->output_offset;
2728 if (! finfo->info->relocateable)
2729 osym.st_value += isec->output_section->vma;
2730
2731 if (! elf_link_output_sym (finfo, name, &osym, isec))
2732 return false;
2733 }
2734
2735 /* Relocate the contents of each section. */
2736 for (o = input_bfd->sections; o != NULL; o = o->next)
2737 {
2738 if ((o->flags & SEC_HAS_CONTENTS) == 0)
2739 continue;
2740
2741 if ((o->flags & SEC_IN_MEMORY) != 0
2742 && input_bfd == elf_hash_table (finfo->info)->dynobj)
2743 {
2744 /* Section was created by elf_link_create_dynamic_sections.
2745 FIXME: This test is fragile. */
2746 continue;
2747 }
2748
2749 /* Read the contents of the section. */
2750 if (! bfd_get_section_contents (input_bfd, o, finfo->contents,
2751 (file_ptr) 0, o->_raw_size))
2752 return false;
2753
2754 if ((o->flags & SEC_RELOC) != 0)
2755 {
2756 Elf_Internal_Rela *internal_relocs;
2757
2758 /* Get the swapped relocs. */
2759 internal_relocs = elf_link_read_relocs (input_bfd, o,
2760 finfo->external_relocs,
2761 finfo->internal_relocs,
2762 false);
2763 if (internal_relocs == NULL
2764 && o->reloc_count > 0)
2765 return false;
2766
2767 /* Relocate the section by invoking a back end routine.
2768
2769 The back end routine is responsible for adjusting the
2770 section contents as necessary, and (if using Rela relocs
2771 and generating a relocateable output file) adjusting the
2772 reloc addend as necessary.
2773
2774 The back end routine does not have to worry about setting
2775 the reloc address or the reloc symbol index.
2776
2777 The back end routine is given a pointer to the swapped in
2778 internal symbols, and can access the hash table entries
2779 for the external symbols via elf_sym_hashes (input_bfd).
2780
2781 When generating relocateable output, the back end routine
2782 must handle STB_LOCAL/STT_SECTION symbols specially. The
2783 output symbol is going to be a section symbol
2784 corresponding to the output section, which will require
2785 the addend to be adjusted. */
2786
2787 if (! (*relocate_section) (output_bfd, finfo->info,
2788 input_bfd, o,
2789 finfo->contents,
2790 internal_relocs,
2791 finfo->internal_syms,
2792 finfo->sections))
2793 return false;
2794
2795 if (finfo->info->relocateable)
2796 {
2797 Elf_Internal_Rela *irela;
2798 Elf_Internal_Rela *irelaend;
2799 struct elf_link_hash_entry **rel_hash;
2800 Elf_Internal_Shdr *input_rel_hdr;
2801 Elf_Internal_Shdr *output_rel_hdr;
2802
2803 /* Adjust the reloc addresses and symbol indices. */
2804
2805 irela = internal_relocs;
2806 irelaend = irela + o->reloc_count;
2807 rel_hash = (elf_section_data (o->output_section)->rel_hashes
2808 + o->output_section->reloc_count);
2809 for (; irela < irelaend; irela++, rel_hash++)
2810 {
2811 long r_symndx;
2812 Elf_Internal_Sym *isym;
2813 asection *sec;
2814
2815 irela->r_offset += o->output_offset;
2816
2817 r_symndx = ELF_R_SYM (irela->r_info);
2818
2819 if (r_symndx == 0)
2820 continue;
2821
2822 if (r_symndx >= locsymcount
2823 || (elf_bad_symtab (input_bfd)
2824 && finfo->sections[r_symndx] == NULL))
2825 {
2826 long indx;
2827
2828 /* This is a reloc against a global symbol. We
2829 have not yet output all the local symbols, so
2830 we do not know the symbol index of any global
2831 symbol. We set the rel_hash entry for this
2832 reloc to point to the global hash table entry
2833 for this symbol. The symbol index is then
2834 set at the end of elf_bfd_final_link. */
2835 indx = r_symndx - extsymoff;
2836 *rel_hash = elf_sym_hashes (input_bfd)[indx];
2837
2838 /* Setting the index to -2 tells
2839 elf_link_output_extsym that this symbol is
2840 used by a reloc. */
2841 BFD_ASSERT ((*rel_hash)->indx < 0);
2842 (*rel_hash)->indx = -2;
2843
2844 continue;
2845 }
2846
2847 /* This is a reloc against a local symbol. */
2848
2849 *rel_hash = NULL;
2850 isym = finfo->internal_syms + r_symndx;
2851 sec = finfo->sections[r_symndx];
2852 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
2853 {
2854 /* I suppose the backend ought to fill in the
2855 section of any STT_SECTION symbol against a
2856 processor specific section. */
2857 if (sec != NULL && bfd_is_abs_section (sec))
2858 r_symndx = 0;
2859 else if (sec == NULL || sec->owner == NULL)
2860 {
2861 bfd_set_error (bfd_error_bad_value);
2862 return false;
2863 }
2864 else
2865 {
2866 r_symndx = sec->output_section->target_index;
2867 BFD_ASSERT (r_symndx != 0);
2868 }
2869 }
2870 else
2871 {
2872 if (finfo->indices[r_symndx] == -1)
2873 {
2874 unsigned long link;
2875 const char *name;
2876 asection *osec;
2877
2878 if (finfo->info->strip == strip_all)
2879 {
2880 /* You can't do ld -r -s. */
2881 bfd_set_error (bfd_error_invalid_operation);
2882 return false;
2883 }
2884
2885 /* This symbol was skipped earlier, but
2886 since it is needed by a reloc, we
2887 must output it now. */
2888 link = symtab_hdr->sh_link;
2889 name = bfd_elf_string_from_elf_section (input_bfd,
2890 link,
2891 isym->st_name);
2892 if (name == NULL)
2893 return false;
2894
2895 osec = sec->output_section;
2896 isym->st_shndx =
2897 _bfd_elf_section_from_bfd_section (output_bfd,
2898 osec);
2899 if (isym->st_shndx == (unsigned short) -1)
2900 return false;
2901
2902 isym->st_value += sec->output_offset;
2903 if (! finfo->info->relocateable)
2904 isym->st_value += osec->vma;
2905
2906 finfo->indices[r_symndx] = output_bfd->symcount;
2907
2908 if (! elf_link_output_sym (finfo, name, isym, sec))
2909 return false;
2910 }
2911
2912 r_symndx = finfo->indices[r_symndx];
2913 }
2914
2915 irela->r_info = ELF_R_INFO (r_symndx,
2916 ELF_R_TYPE (irela->r_info));
2917 }
2918
2919 /* Swap out the relocs. */
2920 input_rel_hdr = &elf_section_data (o)->rel_hdr;
2921 output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
2922 BFD_ASSERT (output_rel_hdr->sh_entsize
2923 == input_rel_hdr->sh_entsize);
2924 irela = internal_relocs;
2925 irelaend = irela + o->reloc_count;
2926 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
2927 {
2928 Elf_External_Rel *erel;
2929
2930 erel = ((Elf_External_Rel *) output_rel_hdr->contents
2931 + o->output_section->reloc_count);
2932 for (; irela < irelaend; irela++, erel++)
2933 {
2934 Elf_Internal_Rel irel;
2935
2936 irel.r_offset = irela->r_offset;
2937 irel.r_info = irela->r_info;
2938 BFD_ASSERT (irela->r_addend == 0);
2939 elf_swap_reloc_out (output_bfd, &irel, erel);
2940 }
2941 }
2942 else
2943 {
2944 Elf_External_Rela *erela;
2945
2946 BFD_ASSERT (input_rel_hdr->sh_entsize
2947 == sizeof (Elf_External_Rela));
2948 erela = ((Elf_External_Rela *) output_rel_hdr->contents
2949 + o->output_section->reloc_count);
2950 for (; irela < irelaend; irela++, erela++)
2951 elf_swap_reloca_out (output_bfd, irela, erela);
2952 }
2953
2954 o->output_section->reloc_count += o->reloc_count;
2955 }
2956 }
2957
2958 /* Write out the modified section contents. */
2959 if (! bfd_set_section_contents (output_bfd, o->output_section,
2960 finfo->contents, o->output_offset,
2961 (o->_cooked_size != 0
2962 ? o->_cooked_size
2963 : o->_raw_size)))
2964 return false;
2965 }
2966
2967 return true;
2968 }
2969
2970 /* Generate a reloc when linking an ELF file. This is a reloc
2971 requested by the linker, and does come from any input file. This
2972 is used to build constructor and destructor tables when linking
2973 with -Ur. */
2974
2975 static boolean
2976 elf_reloc_link_order (output_bfd, info, output_section, link_order)
2977 bfd *output_bfd;
2978 struct bfd_link_info *info;
2979 asection *output_section;
2980 struct bfd_link_order *link_order;
2981 {
2982 reloc_howto_type *howto;
2983 long indx;
2984 bfd_vma offset;
2985 struct elf_link_hash_entry **rel_hash_ptr;
2986 Elf_Internal_Shdr *rel_hdr;
2987
2988 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
2989 if (howto == NULL)
2990 {
2991 bfd_set_error (bfd_error_bad_value);
2992 return false;
2993 }
2994
2995 /* If this is an inplace reloc, we must write the addend into the
2996 object file. */
2997 if (howto->partial_inplace
2998 && link_order->u.reloc.p->addend != 0)
2999 {
3000 bfd_size_type size;
3001 bfd_reloc_status_type rstat;
3002 bfd_byte *buf;
3003 boolean ok;
3004
3005 size = bfd_get_reloc_size (howto);
3006 buf = (bfd_byte *) bfd_zmalloc (size);
3007 if (buf == (bfd_byte *) NULL)
3008 {
3009 bfd_set_error (bfd_error_no_memory);
3010 return false;
3011 }
3012 rstat = _bfd_relocate_contents (howto, output_bfd,
3013 link_order->u.reloc.p->addend, buf);
3014 switch (rstat)
3015 {
3016 case bfd_reloc_ok:
3017 break;
3018 default:
3019 case bfd_reloc_outofrange:
3020 abort ();
3021 case bfd_reloc_overflow:
3022 if (! ((*info->callbacks->reloc_overflow)
3023 (info,
3024 (link_order->type == bfd_section_reloc_link_order
3025 ? bfd_section_name (output_bfd,
3026 link_order->u.reloc.p->u.section)
3027 : link_order->u.reloc.p->u.name),
3028 howto->name, link_order->u.reloc.p->addend,
3029 (bfd *) NULL, (asection *) NULL, (bfd_vma) 0)))
3030 {
3031 free (buf);
3032 return false;
3033 }
3034 break;
3035 }
3036 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
3037 (file_ptr) link_order->offset, size);
3038 free (buf);
3039 if (! ok)
3040 return false;
3041 }
3042
3043 /* Figure out the symbol index. */
3044 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
3045 + output_section->reloc_count);
3046 if (link_order->type == bfd_section_reloc_link_order)
3047 {
3048 indx = link_order->u.reloc.p->u.section->target_index;
3049 BFD_ASSERT (indx != 0);
3050 *rel_hash_ptr = NULL;
3051 }
3052 else
3053 {
3054 struct elf_link_hash_entry *h;
3055
3056 h = elf_link_hash_lookup (elf_hash_table (info),
3057 link_order->u.reloc.p->u.name,
3058 false, false, true);
3059 if (h != NULL)
3060 {
3061 /* Setting the index to -2 tells elf_link_output_extsym that
3062 this symbol is used by a reloc. */
3063 h->indx = -2;
3064 *rel_hash_ptr = h;
3065 indx = 0;
3066 }
3067 else
3068 {
3069 if (! ((*info->callbacks->unattached_reloc)
3070 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
3071 (asection *) NULL, (bfd_vma) 0)))
3072 return false;
3073 indx = 0;
3074 }
3075 }
3076
3077 /* The address of a reloc is relative to the section in a
3078 relocateable file, and is a virtual address in an executable
3079 file. */
3080 offset = link_order->offset;
3081 if (! info->relocateable)
3082 offset += output_section->vma;
3083
3084 rel_hdr = &elf_section_data (output_section)->rel_hdr;
3085
3086 if (rel_hdr->sh_type == SHT_REL)
3087 {
3088 Elf_Internal_Rel irel;
3089 Elf_External_Rel *erel;
3090
3091 irel.r_offset = offset;
3092 irel.r_info = ELF_R_INFO (indx, howto->type);
3093 erel = ((Elf_External_Rel *) rel_hdr->contents
3094 + output_section->reloc_count);
3095 elf_swap_reloc_out (output_bfd, &irel, erel);
3096 }
3097 else
3098 {
3099 Elf_Internal_Rela irela;
3100 Elf_External_Rela *erela;
3101
3102 irela.r_offset = offset;
3103 irela.r_info = ELF_R_INFO (indx, howto->type);
3104 irela.r_addend = link_order->u.reloc.p->addend;
3105 erela = ((Elf_External_Rela *) rel_hdr->contents
3106 + output_section->reloc_count);
3107 elf_swap_reloca_out (output_bfd, &irela, erela);
3108 }
3109
3110 ++output_section->reloc_count;
3111
3112 return true;
3113 }
3114
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