Initial revision
[binutils.git] / bfd / elflink.h
blob32bfab0e80214fb2a8c78076127cda4442f4fba0
1 /* ELF linker support.
2 Copyright 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
20 /* ELF linker code. */
22 /* This struct is used to pass information to routines called via
23 elf_link_hash_traverse which must return failure. */
25 struct elf_info_failed
27 boolean failed;
28 struct bfd_link_info *info;
31 static boolean elf_link_add_object_symbols
32 PARAMS ((bfd *, struct bfd_link_info *));
33 static boolean elf_link_add_archive_symbols
34 PARAMS ((bfd *, struct bfd_link_info *));
35 static boolean elf_merge_symbol
36 PARAMS ((bfd *, struct bfd_link_info *, const char *, Elf_Internal_Sym *,
37 asection **, bfd_vma *, struct elf_link_hash_entry **,
38 boolean *, boolean *, boolean *));
39 static boolean elf_export_symbol
40 PARAMS ((struct elf_link_hash_entry *, PTR));
41 static boolean elf_fix_symbol_flags
42 PARAMS ((struct elf_link_hash_entry *, struct elf_info_failed *));
43 static boolean elf_adjust_dynamic_symbol
44 PARAMS ((struct elf_link_hash_entry *, PTR));
45 static boolean elf_link_find_version_dependencies
46 PARAMS ((struct elf_link_hash_entry *, PTR));
47 static boolean elf_link_find_version_dependencies
48 PARAMS ((struct elf_link_hash_entry *, PTR));
49 static boolean elf_link_assign_sym_version
50 PARAMS ((struct elf_link_hash_entry *, PTR));
51 static boolean elf_link_renumber_dynsyms
52 PARAMS ((struct elf_link_hash_entry *, PTR));
53 static boolean elf_collect_hash_codes
54 PARAMS ((struct elf_link_hash_entry *, PTR));
56 /* Given an ELF BFD, add symbols to the global hash table as
57 appropriate. */
59 boolean
60 elf_bfd_link_add_symbols (abfd, info)
61 bfd *abfd;
62 struct bfd_link_info *info;
64 switch (bfd_get_format (abfd))
66 case bfd_object:
67 return elf_link_add_object_symbols (abfd, info);
68 case bfd_archive:
69 return elf_link_add_archive_symbols (abfd, info);
70 default:
71 bfd_set_error (bfd_error_wrong_format);
72 return false;
77 /* Add symbols from an ELF archive file to the linker hash table. We
78 don't use _bfd_generic_link_add_archive_symbols because of a
79 problem which arises on UnixWare. The UnixWare libc.so is an
80 archive which includes an entry libc.so.1 which defines a bunch of
81 symbols. The libc.so archive also includes a number of other
82 object files, which also define symbols, some of which are the same
83 as those defined in libc.so.1. Correct linking requires that we
84 consider each object file in turn, and include it if it defines any
85 symbols we need. _bfd_generic_link_add_archive_symbols does not do
86 this; it looks through the list of undefined symbols, and includes
87 any object file which defines them. When this algorithm is used on
88 UnixWare, it winds up pulling in libc.so.1 early and defining a
89 bunch of symbols. This means that some of the other objects in the
90 archive are not included in the link, which is incorrect since they
91 precede libc.so.1 in the archive.
93 Fortunately, ELF archive handling is simpler than that done by
94 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
95 oddities. In ELF, if we find a symbol in the archive map, and the
96 symbol is currently undefined, we know that we must pull in that
97 object file.
99 Unfortunately, we do have to make multiple passes over the symbol
100 table until nothing further is resolved. */
102 static boolean
103 elf_link_add_archive_symbols (abfd, info)
104 bfd *abfd;
105 struct bfd_link_info *info;
107 symindex c;
108 boolean *defined = NULL;
109 boolean *included = NULL;
110 carsym *symdefs;
111 boolean loop;
113 if (! bfd_has_map (abfd))
115 /* An empty archive is a special case. */
116 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
117 return true;
118 bfd_set_error (bfd_error_no_armap);
119 return false;
122 /* Keep track of all symbols we know to be already defined, and all
123 files we know to be already included. This is to speed up the
124 second and subsequent passes. */
125 c = bfd_ardata (abfd)->symdef_count;
126 if (c == 0)
127 return true;
128 defined = (boolean *) bfd_malloc (c * sizeof (boolean));
129 included = (boolean *) bfd_malloc (c * sizeof (boolean));
130 if (defined == (boolean *) NULL || included == (boolean *) NULL)
131 goto error_return;
132 memset (defined, 0, c * sizeof (boolean));
133 memset (included, 0, c * sizeof (boolean));
135 symdefs = bfd_ardata (abfd)->symdefs;
139 file_ptr last;
140 symindex i;
141 carsym *symdef;
142 carsym *symdefend;
144 loop = false;
145 last = -1;
147 symdef = symdefs;
148 symdefend = symdef + c;
149 for (i = 0; symdef < symdefend; symdef++, i++)
151 struct elf_link_hash_entry *h;
152 bfd *element;
153 struct bfd_link_hash_entry *undefs_tail;
154 symindex mark;
156 if (defined[i] || included[i])
157 continue;
158 if (symdef->file_offset == last)
160 included[i] = true;
161 continue;
164 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
165 false, false, false);
167 if (h == NULL)
169 char *p, *copy;
171 /* If this is a default version (the name contains @@),
172 look up the symbol again without the version. The
173 effect is that references to the symbol without the
174 version will be matched by the default symbol in the
175 archive. */
177 p = strchr (symdef->name, ELF_VER_CHR);
178 if (p == NULL || p[1] != ELF_VER_CHR)
179 continue;
181 copy = bfd_alloc (abfd, p - symdef->name + 1);
182 if (copy == NULL)
183 goto error_return;
184 memcpy (copy, symdef->name, p - symdef->name);
185 copy[p - symdef->name] = '\0';
187 h = elf_link_hash_lookup (elf_hash_table (info), copy,
188 false, false, false);
190 bfd_release (abfd, copy);
193 if (h == NULL)
194 continue;
196 if (h->root.type != bfd_link_hash_undefined)
198 if (h->root.type != bfd_link_hash_undefweak)
199 defined[i] = true;
200 continue;
203 /* We need to include this archive member. */
205 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
206 if (element == (bfd *) NULL)
207 goto error_return;
209 if (! bfd_check_format (element, bfd_object))
210 goto error_return;
212 /* Doublecheck that we have not included this object
213 already--it should be impossible, but there may be
214 something wrong with the archive. */
215 if (element->archive_pass != 0)
217 bfd_set_error (bfd_error_bad_value);
218 goto error_return;
220 element->archive_pass = 1;
222 undefs_tail = info->hash->undefs_tail;
224 if (! (*info->callbacks->add_archive_element) (info, element,
225 symdef->name))
226 goto error_return;
227 if (! elf_link_add_object_symbols (element, info))
228 goto error_return;
230 /* If there are any new undefined symbols, we need to make
231 another pass through the archive in order to see whether
232 they can be defined. FIXME: This isn't perfect, because
233 common symbols wind up on undefs_tail and because an
234 undefined symbol which is defined later on in this pass
235 does not require another pass. This isn't a bug, but it
236 does make the code less efficient than it could be. */
237 if (undefs_tail != info->hash->undefs_tail)
238 loop = true;
240 /* Look backward to mark all symbols from this object file
241 which we have already seen in this pass. */
242 mark = i;
245 included[mark] = true;
246 if (mark == 0)
247 break;
248 --mark;
250 while (symdefs[mark].file_offset == symdef->file_offset);
252 /* We mark subsequent symbols from this object file as we go
253 on through the loop. */
254 last = symdef->file_offset;
257 while (loop);
259 free (defined);
260 free (included);
262 return true;
264 error_return:
265 if (defined != (boolean *) NULL)
266 free (defined);
267 if (included != (boolean *) NULL)
268 free (included);
269 return false;
272 /* This function is called when we want to define a new symbol. It
273 handles the various cases which arise when we find a definition in
274 a dynamic object, or when there is already a definition in a
275 dynamic object. The new symbol is described by NAME, SYM, PSEC,
276 and PVALUE. We set SYM_HASH to the hash table entry. We set
277 OVERRIDE if the old symbol is overriding a new definition. We set
278 TYPE_CHANGE_OK if it is OK for the type to change. We set
279 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
280 change, we mean that we shouldn't warn if the type or size does
281 change. */
283 static boolean
284 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
285 override, type_change_ok, size_change_ok)
286 bfd *abfd;
287 struct bfd_link_info *info;
288 const char *name;
289 Elf_Internal_Sym *sym;
290 asection **psec;
291 bfd_vma *pvalue;
292 struct elf_link_hash_entry **sym_hash;
293 boolean *override;
294 boolean *type_change_ok;
295 boolean *size_change_ok;
297 asection *sec;
298 struct elf_link_hash_entry *h;
299 int bind;
300 bfd *oldbfd;
301 boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
303 *override = false;
305 sec = *psec;
306 bind = ELF_ST_BIND (sym->st_info);
308 if (! bfd_is_und_section (sec))
309 h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
310 else
311 h = ((struct elf_link_hash_entry *)
312 bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
313 if (h == NULL)
314 return false;
315 *sym_hash = h;
317 /* This code is for coping with dynamic objects, and is only useful
318 if we are doing an ELF link. */
319 if (info->hash->creator != abfd->xvec)
320 return true;
322 /* For merging, we only care about real symbols. */
324 while (h->root.type == bfd_link_hash_indirect
325 || h->root.type == bfd_link_hash_warning)
326 h = (struct elf_link_hash_entry *) h->root.u.i.link;
328 /* If we just created the symbol, mark it as being an ELF symbol.
329 Other than that, there is nothing to do--there is no merge issue
330 with a newly defined symbol--so we just return. */
332 if (h->root.type == bfd_link_hash_new)
334 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
335 return true;
338 /* OLDBFD is a BFD associated with the existing symbol. */
340 switch (h->root.type)
342 default:
343 oldbfd = NULL;
344 break;
346 case bfd_link_hash_undefined:
347 case bfd_link_hash_undefweak:
348 oldbfd = h->root.u.undef.abfd;
349 break;
351 case bfd_link_hash_defined:
352 case bfd_link_hash_defweak:
353 oldbfd = h->root.u.def.section->owner;
354 break;
356 case bfd_link_hash_common:
357 oldbfd = h->root.u.c.p->section->owner;
358 break;
361 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
362 respectively, is from a dynamic object. */
364 if ((abfd->flags & DYNAMIC) != 0)
365 newdyn = true;
366 else
367 newdyn = false;
369 if (oldbfd == NULL || (oldbfd->flags & DYNAMIC) == 0)
370 olddyn = false;
371 else
372 olddyn = true;
374 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
375 respectively, appear to be a definition rather than reference. */
377 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
378 newdef = false;
379 else
380 newdef = true;
382 if (h->root.type == bfd_link_hash_undefined
383 || h->root.type == bfd_link_hash_undefweak
384 || h->root.type == bfd_link_hash_common)
385 olddef = false;
386 else
387 olddef = true;
389 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
390 symbol, respectively, appears to be a common symbol in a dynamic
391 object. If a symbol appears in an uninitialized section, and is
392 not weak, and is not a function, then it may be a common symbol
393 which was resolved when the dynamic object was created. We want
394 to treat such symbols specially, because they raise special
395 considerations when setting the symbol size: if the symbol
396 appears as a common symbol in a regular object, and the size in
397 the regular object is larger, we must make sure that we use the
398 larger size. This problematic case can always be avoided in C,
399 but it must be handled correctly when using Fortran shared
400 libraries.
402 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
403 likewise for OLDDYNCOMMON and OLDDEF.
405 Note that this test is just a heuristic, and that it is quite
406 possible to have an uninitialized symbol in a shared object which
407 is really a definition, rather than a common symbol. This could
408 lead to some minor confusion when the symbol really is a common
409 symbol in some regular object. However, I think it will be
410 harmless. */
412 if (newdyn
413 && newdef
414 && (sec->flags & SEC_ALLOC) != 0
415 && (sec->flags & SEC_LOAD) == 0
416 && sym->st_size > 0
417 && bind != STB_WEAK
418 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
419 newdyncommon = true;
420 else
421 newdyncommon = false;
423 if (olddyn
424 && olddef
425 && h->root.type == bfd_link_hash_defined
426 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
427 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
428 && (h->root.u.def.section->flags & SEC_LOAD) == 0
429 && h->size > 0
430 && h->type != STT_FUNC)
431 olddyncommon = true;
432 else
433 olddyncommon = false;
435 /* It's OK to change the type if either the existing symbol or the
436 new symbol is weak. */
438 if (h->root.type == bfd_link_hash_defweak
439 || h->root.type == bfd_link_hash_undefweak
440 || bind == STB_WEAK)
441 *type_change_ok = true;
443 /* It's OK to change the size if either the existing symbol or the
444 new symbol is weak, or if the old symbol is undefined. */
446 if (*type_change_ok
447 || h->root.type == bfd_link_hash_undefined)
448 *size_change_ok = true;
450 /* If both the old and the new symbols look like common symbols in a
451 dynamic object, set the size of the symbol to the larger of the
452 two. */
454 if (olddyncommon
455 && newdyncommon
456 && sym->st_size != h->size)
458 /* Since we think we have two common symbols, issue a multiple
459 common warning if desired. Note that we only warn if the
460 size is different. If the size is the same, we simply let
461 the old symbol override the new one as normally happens with
462 symbols defined in dynamic objects. */
464 if (! ((*info->callbacks->multiple_common)
465 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
466 h->size, abfd, bfd_link_hash_common, sym->st_size)))
467 return false;
469 if (sym->st_size > h->size)
470 h->size = sym->st_size;
472 *size_change_ok = true;
475 /* If we are looking at a dynamic object, and we have found a
476 definition, we need to see if the symbol was already defined by
477 some other object. If so, we want to use the existing
478 definition, and we do not want to report a multiple symbol
479 definition error; we do this by clobbering *PSEC to be
480 bfd_und_section_ptr.
482 We treat a common symbol as a definition if the symbol in the
483 shared library is a function, since common symbols always
484 represent variables; this can cause confusion in principle, but
485 any such confusion would seem to indicate an erroneous program or
486 shared library. We also permit a common symbol in a regular
487 object to override a weak symbol in a shared object. */
489 if (newdyn
490 && newdef
491 && (olddef
492 || (h->root.type == bfd_link_hash_common
493 && (bind == STB_WEAK
494 || ELF_ST_TYPE (sym->st_info) == STT_FUNC))))
496 *override = true;
497 newdef = false;
498 newdyncommon = false;
500 *psec = sec = bfd_und_section_ptr;
501 *size_change_ok = true;
503 /* If we get here when the old symbol is a common symbol, then
504 we are explicitly letting it override a weak symbol or
505 function in a dynamic object, and we don't want to warn about
506 a type change. If the old symbol is a defined symbol, a type
507 change warning may still be appropriate. */
509 if (h->root.type == bfd_link_hash_common)
510 *type_change_ok = true;
513 /* Handle the special case of an old common symbol merging with a
514 new symbol which looks like a common symbol in a shared object.
515 We change *PSEC and *PVALUE to make the new symbol look like a
516 common symbol, and let _bfd_generic_link_add_one_symbol will do
517 the right thing. */
519 if (newdyncommon
520 && h->root.type == bfd_link_hash_common)
522 *override = true;
523 newdef = false;
524 newdyncommon = false;
525 *pvalue = sym->st_size;
526 *psec = sec = bfd_com_section_ptr;
527 *size_change_ok = true;
530 /* If the old symbol is from a dynamic object, and the new symbol is
531 a definition which is not from a dynamic object, then the new
532 symbol overrides the old symbol. Symbols from regular files
533 always take precedence over symbols from dynamic objects, even if
534 they are defined after the dynamic object in the link.
536 As above, we again permit a common symbol in a regular object to
537 override a definition in a shared object if the shared object
538 symbol is a function or is weak. */
540 if (! newdyn
541 && (newdef
542 || (bfd_is_com_section (sec)
543 && (h->root.type == bfd_link_hash_defweak
544 || h->type == STT_FUNC)))
545 && olddyn
546 && olddef
547 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
549 /* Change the hash table entry to undefined, and let
550 _bfd_generic_link_add_one_symbol do the right thing with the
551 new definition. */
553 h->root.type = bfd_link_hash_undefined;
554 h->root.u.undef.abfd = h->root.u.def.section->owner;
555 *size_change_ok = true;
557 olddef = false;
558 olddyncommon = false;
560 /* We again permit a type change when a common symbol may be
561 overriding a function. */
563 if (bfd_is_com_section (sec))
564 *type_change_ok = true;
566 /* This union may have been set to be non-NULL when this symbol
567 was seen in a dynamic object. We must force the union to be
568 NULL, so that it is correct for a regular symbol. */
570 h->verinfo.vertree = NULL;
572 /* In this special case, if H is the target of an indirection,
573 we want the caller to frob with H rather than with the
574 indirect symbol. That will permit the caller to redefine the
575 target of the indirection, rather than the indirect symbol
576 itself. FIXME: This will break the -y option if we store a
577 symbol with a different name. */
578 *sym_hash = h;
581 /* Handle the special case of a new common symbol merging with an
582 old symbol that looks like it might be a common symbol defined in
583 a shared object. Note that we have already handled the case in
584 which a new common symbol should simply override the definition
585 in the shared library. */
587 if (! newdyn
588 && bfd_is_com_section (sec)
589 && olddyncommon)
591 /* It would be best if we could set the hash table entry to a
592 common symbol, but we don't know what to use for the section
593 or the alignment. */
594 if (! ((*info->callbacks->multiple_common)
595 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
596 h->size, abfd, bfd_link_hash_common, sym->st_size)))
597 return false;
599 /* If the predumed common symbol in the dynamic object is
600 larger, pretend that the new symbol has its size. */
602 if (h->size > *pvalue)
603 *pvalue = h->size;
605 /* FIXME: We no longer know the alignment required by the symbol
606 in the dynamic object, so we just wind up using the one from
607 the regular object. */
609 olddef = false;
610 olddyncommon = false;
612 h->root.type = bfd_link_hash_undefined;
613 h->root.u.undef.abfd = h->root.u.def.section->owner;
615 *size_change_ok = true;
616 *type_change_ok = true;
618 h->verinfo.vertree = NULL;
621 return true;
624 /* Add symbols from an ELF object file to the linker hash table. */
626 static boolean
627 elf_link_add_object_symbols (abfd, info)
628 bfd *abfd;
629 struct bfd_link_info *info;
631 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
632 const Elf_Internal_Sym *,
633 const char **, flagword *,
634 asection **, bfd_vma *));
635 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
636 asection *, const Elf_Internal_Rela *));
637 boolean collect;
638 Elf_Internal_Shdr *hdr;
639 size_t symcount;
640 size_t extsymcount;
641 size_t extsymoff;
642 Elf_External_Sym *buf = NULL;
643 struct elf_link_hash_entry **sym_hash;
644 boolean dynamic;
645 bfd_byte *dynver = NULL;
646 Elf_External_Versym *extversym = NULL;
647 Elf_External_Versym *ever;
648 Elf_External_Dyn *dynbuf = NULL;
649 struct elf_link_hash_entry *weaks;
650 Elf_External_Sym *esym;
651 Elf_External_Sym *esymend;
653 add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
654 collect = get_elf_backend_data (abfd)->collect;
656 if ((abfd->flags & DYNAMIC) == 0)
657 dynamic = false;
658 else
660 dynamic = true;
662 /* You can't use -r against a dynamic object. Also, there's no
663 hope of using a dynamic object which does not exactly match
664 the format of the output file. */
665 if (info->relocateable || info->hash->creator != abfd->xvec)
667 bfd_set_error (bfd_error_invalid_operation);
668 goto error_return;
672 /* As a GNU extension, any input sections which are named
673 .gnu.warning.SYMBOL are treated as warning symbols for the given
674 symbol. This differs from .gnu.warning sections, which generate
675 warnings when they are included in an output file. */
676 if (! info->shared)
678 asection *s;
680 for (s = abfd->sections; s != NULL; s = s->next)
682 const char *name;
684 name = bfd_get_section_name (abfd, s);
685 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
687 char *msg;
688 bfd_size_type sz;
690 name += sizeof ".gnu.warning." - 1;
692 /* If this is a shared object, then look up the symbol
693 in the hash table. If it is there, and it is already
694 been defined, then we will not be using the entry
695 from this shared object, so we don't need to warn.
696 FIXME: If we see the definition in a regular object
697 later on, we will warn, but we shouldn't. The only
698 fix is to keep track of what warnings we are supposed
699 to emit, and then handle them all at the end of the
700 link. */
701 if (dynamic && abfd->xvec == info->hash->creator)
703 struct elf_link_hash_entry *h;
705 h = elf_link_hash_lookup (elf_hash_table (info), name,
706 false, false, true);
708 /* FIXME: What about bfd_link_hash_common? */
709 if (h != NULL
710 && (h->root.type == bfd_link_hash_defined
711 || h->root.type == bfd_link_hash_defweak))
713 /* We don't want to issue this warning. Clobber
714 the section size so that the warning does not
715 get copied into the output file. */
716 s->_raw_size = 0;
717 continue;
721 sz = bfd_section_size (abfd, s);
722 msg = (char *) bfd_alloc (abfd, sz + 1);
723 if (msg == NULL)
724 goto error_return;
726 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
727 goto error_return;
729 msg[sz] = '\0';
731 if (! (_bfd_generic_link_add_one_symbol
732 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
733 false, collect, (struct bfd_link_hash_entry **) NULL)))
734 goto error_return;
736 if (! info->relocateable)
738 /* Clobber the section size so that the warning does
739 not get copied into the output file. */
740 s->_raw_size = 0;
746 /* If this is a dynamic object, we always link against the .dynsym
747 symbol table, not the .symtab symbol table. The dynamic linker
748 will only see the .dynsym symbol table, so there is no reason to
749 look at .symtab for a dynamic object. */
751 if (! dynamic || elf_dynsymtab (abfd) == 0)
752 hdr = &elf_tdata (abfd)->symtab_hdr;
753 else
754 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
756 if (dynamic)
758 /* Read in any version definitions. */
760 if (! _bfd_elf_slurp_version_tables (abfd))
761 goto error_return;
763 /* Read in the symbol versions, but don't bother to convert them
764 to internal format. */
765 if (elf_dynversym (abfd) != 0)
767 Elf_Internal_Shdr *versymhdr;
769 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
770 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
771 if (extversym == NULL)
772 goto error_return;
773 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
774 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
775 != versymhdr->sh_size))
776 goto error_return;
780 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
782 /* The sh_info field of the symtab header tells us where the
783 external symbols start. We don't care about the local symbols at
784 this point. */
785 if (elf_bad_symtab (abfd))
787 extsymcount = symcount;
788 extsymoff = 0;
790 else
792 extsymcount = symcount - hdr->sh_info;
793 extsymoff = hdr->sh_info;
796 buf = ((Elf_External_Sym *)
797 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
798 if (buf == NULL && extsymcount != 0)
799 goto error_return;
801 /* We store a pointer to the hash table entry for each external
802 symbol. */
803 sym_hash = ((struct elf_link_hash_entry **)
804 bfd_alloc (abfd,
805 extsymcount * sizeof (struct elf_link_hash_entry *)));
806 if (sym_hash == NULL)
807 goto error_return;
808 elf_sym_hashes (abfd) = sym_hash;
810 if (! dynamic)
812 /* If we are creating a shared library, create all the dynamic
813 sections immediately. We need to attach them to something,
814 so we attach them to this BFD, provided it is the right
815 format. FIXME: If there are no input BFD's of the same
816 format as the output, we can't make a shared library. */
817 if (info->shared
818 && ! elf_hash_table (info)->dynamic_sections_created
819 && abfd->xvec == info->hash->creator)
821 if (! elf_link_create_dynamic_sections (abfd, info))
822 goto error_return;
825 else
827 asection *s;
828 boolean add_needed;
829 const char *name;
830 bfd_size_type oldsize;
831 bfd_size_type strindex;
833 /* Find the name to use in a DT_NEEDED entry that refers to this
834 object. If the object has a DT_SONAME entry, we use it.
835 Otherwise, if the generic linker stuck something in
836 elf_dt_name, we use that. Otherwise, we just use the file
837 name. If the generic linker put a null string into
838 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
839 there is a DT_SONAME entry. */
840 add_needed = true;
841 name = bfd_get_filename (abfd);
842 if (elf_dt_name (abfd) != NULL)
844 name = elf_dt_name (abfd);
845 if (*name == '\0')
846 add_needed = false;
848 s = bfd_get_section_by_name (abfd, ".dynamic");
849 if (s != NULL)
851 Elf_External_Dyn *extdyn;
852 Elf_External_Dyn *extdynend;
853 int elfsec;
854 unsigned long link;
856 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
857 if (dynbuf == NULL)
858 goto error_return;
860 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
861 (file_ptr) 0, s->_raw_size))
862 goto error_return;
864 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
865 if (elfsec == -1)
866 goto error_return;
867 link = elf_elfsections (abfd)[elfsec]->sh_link;
869 extdyn = dynbuf;
870 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
871 for (; extdyn < extdynend; extdyn++)
873 Elf_Internal_Dyn dyn;
875 elf_swap_dyn_in (abfd, extdyn, &dyn);
876 if (dyn.d_tag == DT_SONAME)
878 name = bfd_elf_string_from_elf_section (abfd, link,
879 dyn.d_un.d_val);
880 if (name == NULL)
881 goto error_return;
883 if (dyn.d_tag == DT_NEEDED)
885 struct bfd_link_needed_list *n, **pn;
886 char *fnm, *anm;
888 n = ((struct bfd_link_needed_list *)
889 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
890 fnm = bfd_elf_string_from_elf_section (abfd, link,
891 dyn.d_un.d_val);
892 if (n == NULL || fnm == NULL)
893 goto error_return;
894 anm = bfd_alloc (abfd, strlen (fnm) + 1);
895 if (anm == NULL)
896 goto error_return;
897 strcpy (anm, fnm);
898 n->name = anm;
899 n->by = abfd;
900 n->next = NULL;
901 for (pn = &elf_hash_table (info)->needed;
902 *pn != NULL;
903 pn = &(*pn)->next)
905 *pn = n;
909 free (dynbuf);
910 dynbuf = NULL;
913 /* We do not want to include any of the sections in a dynamic
914 object in the output file. We hack by simply clobbering the
915 list of sections in the BFD. This could be handled more
916 cleanly by, say, a new section flag; the existing
917 SEC_NEVER_LOAD flag is not the one we want, because that one
918 still implies that the section takes up space in the output
919 file. */
920 abfd->sections = NULL;
921 abfd->section_count = 0;
923 /* If this is the first dynamic object found in the link, create
924 the special sections required for dynamic linking. */
925 if (! elf_hash_table (info)->dynamic_sections_created)
927 if (! elf_link_create_dynamic_sections (abfd, info))
928 goto error_return;
931 if (add_needed)
933 /* Add a DT_NEEDED entry for this dynamic object. */
934 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
935 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
936 true, false);
937 if (strindex == (bfd_size_type) -1)
938 goto error_return;
940 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
942 asection *sdyn;
943 Elf_External_Dyn *dyncon, *dynconend;
945 /* The hash table size did not change, which means that
946 the dynamic object name was already entered. If we
947 have already included this dynamic object in the
948 link, just ignore it. There is no reason to include
949 a particular dynamic object more than once. */
950 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
951 ".dynamic");
952 BFD_ASSERT (sdyn != NULL);
954 dyncon = (Elf_External_Dyn *) sdyn->contents;
955 dynconend = (Elf_External_Dyn *) (sdyn->contents +
956 sdyn->_raw_size);
957 for (; dyncon < dynconend; dyncon++)
959 Elf_Internal_Dyn dyn;
961 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
962 &dyn);
963 if (dyn.d_tag == DT_NEEDED
964 && dyn.d_un.d_val == strindex)
966 if (buf != NULL)
967 free (buf);
968 if (extversym != NULL)
969 free (extversym);
970 return true;
975 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
976 goto error_return;
979 /* Save the SONAME, if there is one, because sometimes the
980 linker emulation code will need to know it. */
981 if (*name == '\0')
982 name = bfd_get_filename (abfd);
983 elf_dt_name (abfd) = name;
986 if (bfd_seek (abfd,
987 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
988 SEEK_SET) != 0
989 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
990 != extsymcount * sizeof (Elf_External_Sym)))
991 goto error_return;
993 weaks = NULL;
995 ever = extversym != NULL ? extversym + extsymoff : NULL;
996 esymend = buf + extsymcount;
997 for (esym = buf;
998 esym < esymend;
999 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1001 Elf_Internal_Sym sym;
1002 int bind;
1003 bfd_vma value;
1004 asection *sec;
1005 flagword flags;
1006 const char *name;
1007 struct elf_link_hash_entry *h;
1008 boolean definition;
1009 boolean size_change_ok, type_change_ok;
1010 boolean new_weakdef;
1011 unsigned int old_alignment;
1013 elf_swap_symbol_in (abfd, esym, &sym);
1015 flags = BSF_NO_FLAGS;
1016 sec = NULL;
1017 value = sym.st_value;
1018 *sym_hash = NULL;
1020 bind = ELF_ST_BIND (sym.st_info);
1021 if (bind == STB_LOCAL)
1023 /* This should be impossible, since ELF requires that all
1024 global symbols follow all local symbols, and that sh_info
1025 point to the first global symbol. Unfortunatealy, Irix 5
1026 screws this up. */
1027 continue;
1029 else if (bind == STB_GLOBAL)
1031 if (sym.st_shndx != SHN_UNDEF
1032 && sym.st_shndx != SHN_COMMON)
1033 flags = BSF_GLOBAL;
1034 else
1035 flags = 0;
1037 else if (bind == STB_WEAK)
1038 flags = BSF_WEAK;
1039 else
1041 /* Leave it up to the processor backend. */
1044 if (sym.st_shndx == SHN_UNDEF)
1045 sec = bfd_und_section_ptr;
1046 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1048 sec = section_from_elf_index (abfd, sym.st_shndx);
1049 if (sec == NULL)
1050 sec = bfd_abs_section_ptr;
1051 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1052 value -= sec->vma;
1054 else if (sym.st_shndx == SHN_ABS)
1055 sec = bfd_abs_section_ptr;
1056 else if (sym.st_shndx == SHN_COMMON)
1058 sec = bfd_com_section_ptr;
1059 /* What ELF calls the size we call the value. What ELF
1060 calls the value we call the alignment. */
1061 value = sym.st_size;
1063 else
1065 /* Leave it up to the processor backend. */
1068 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1069 if (name == (const char *) NULL)
1070 goto error_return;
1072 if (add_symbol_hook)
1074 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1075 &value))
1076 goto error_return;
1078 /* The hook function sets the name to NULL if this symbol
1079 should be skipped for some reason. */
1080 if (name == (const char *) NULL)
1081 continue;
1084 /* Sanity check that all possibilities were handled. */
1085 if (sec == (asection *) NULL)
1087 bfd_set_error (bfd_error_bad_value);
1088 goto error_return;
1091 if (bfd_is_und_section (sec)
1092 || bfd_is_com_section (sec))
1093 definition = false;
1094 else
1095 definition = true;
1097 size_change_ok = false;
1098 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1099 old_alignment = 0;
1100 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1102 Elf_Internal_Versym iver;
1103 unsigned int vernum = 0;
1104 boolean override;
1106 if (ever != NULL)
1108 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1109 vernum = iver.vs_vers & VERSYM_VERSION;
1111 /* If this is a hidden symbol, or if it is not version
1112 1, we append the version name to the symbol name.
1113 However, we do not modify a non-hidden absolute
1114 symbol, because it might be the version symbol
1115 itself. FIXME: What if it isn't? */
1116 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1117 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1119 const char *verstr;
1120 int namelen, newlen;
1121 char *newname, *p;
1123 if (sym.st_shndx != SHN_UNDEF)
1125 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1127 (*_bfd_error_handler)
1128 (_("%s: %s: invalid version %u (max %d)"),
1129 bfd_get_filename (abfd), name, vernum,
1130 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1131 bfd_set_error (bfd_error_bad_value);
1132 goto error_return;
1134 else if (vernum > 1)
1135 verstr =
1136 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1137 else
1138 verstr = "";
1140 else
1142 /* We cannot simply test for the number of
1143 entries in the VERNEED section since the
1144 numbers for the needed versions do not start
1145 at 0. */
1146 Elf_Internal_Verneed *t;
1148 verstr = NULL;
1149 for (t = elf_tdata (abfd)->verref;
1150 t != NULL;
1151 t = t->vn_nextref)
1153 Elf_Internal_Vernaux *a;
1155 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1157 if (a->vna_other == vernum)
1159 verstr = a->vna_nodename;
1160 break;
1163 if (a != NULL)
1164 break;
1166 if (verstr == NULL)
1168 (*_bfd_error_handler)
1169 (_("%s: %s: invalid needed version %d"),
1170 bfd_get_filename (abfd), name, vernum);
1171 bfd_set_error (bfd_error_bad_value);
1172 goto error_return;
1176 namelen = strlen (name);
1177 newlen = namelen + strlen (verstr) + 2;
1178 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1179 ++newlen;
1181 newname = (char *) bfd_alloc (abfd, newlen);
1182 if (newname == NULL)
1183 goto error_return;
1184 strcpy (newname, name);
1185 p = newname + namelen;
1186 *p++ = ELF_VER_CHR;
1187 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1188 *p++ = ELF_VER_CHR;
1189 strcpy (p, verstr);
1191 name = newname;
1195 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1196 sym_hash, &override, &type_change_ok,
1197 &size_change_ok))
1198 goto error_return;
1200 if (override)
1201 definition = false;
1203 h = *sym_hash;
1204 while (h->root.type == bfd_link_hash_indirect
1205 || h->root.type == bfd_link_hash_warning)
1206 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1208 /* Remember the old alignment if this is a common symbol, so
1209 that we don't reduce the alignment later on. We can't
1210 check later, because _bfd_generic_link_add_one_symbol
1211 will set a default for the alignment which we want to
1212 override. */
1213 if (h->root.type == bfd_link_hash_common)
1214 old_alignment = h->root.u.c.p->alignment_power;
1216 if (elf_tdata (abfd)->verdef != NULL
1217 && ! override
1218 && vernum > 1
1219 && definition)
1220 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1223 if (! (_bfd_generic_link_add_one_symbol
1224 (info, abfd, name, flags, sec, value, (const char *) NULL,
1225 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1226 goto error_return;
1228 h = *sym_hash;
1229 while (h->root.type == bfd_link_hash_indirect
1230 || h->root.type == bfd_link_hash_warning)
1231 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1232 *sym_hash = h;
1234 new_weakdef = false;
1235 if (dynamic
1236 && definition
1237 && (flags & BSF_WEAK) != 0
1238 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1239 && info->hash->creator->flavour == bfd_target_elf_flavour
1240 && h->weakdef == NULL)
1242 /* Keep a list of all weak defined non function symbols from
1243 a dynamic object, using the weakdef field. Later in this
1244 function we will set the weakdef field to the correct
1245 value. We only put non-function symbols from dynamic
1246 objects on this list, because that happens to be the only
1247 time we need to know the normal symbol corresponding to a
1248 weak symbol, and the information is time consuming to
1249 figure out. If the weakdef field is not already NULL,
1250 then this symbol was already defined by some previous
1251 dynamic object, and we will be using that previous
1252 definition anyhow. */
1254 h->weakdef = weaks;
1255 weaks = h;
1256 new_weakdef = true;
1259 /* Set the alignment of a common symbol. */
1260 if (sym.st_shndx == SHN_COMMON
1261 && h->root.type == bfd_link_hash_common)
1263 unsigned int align;
1265 align = bfd_log2 (sym.st_value);
1266 if (align > old_alignment)
1267 h->root.u.c.p->alignment_power = align;
1270 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1272 int old_flags;
1273 boolean dynsym;
1274 int new_flag;
1276 /* Remember the symbol size and type. */
1277 if (sym.st_size != 0
1278 && (definition || h->size == 0))
1280 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1281 (*_bfd_error_handler)
1282 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1283 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1284 bfd_get_filename (abfd));
1286 h->size = sym.st_size;
1289 /* If this is a common symbol, then we always want H->SIZE
1290 to be the size of the common symbol. The code just above
1291 won't fix the size if a common symbol becomes larger. We
1292 don't warn about a size change here, because that is
1293 covered by --warn-common. */
1294 if (h->root.type == bfd_link_hash_common)
1295 h->size = h->root.u.c.size;
1297 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1298 && (definition || h->type == STT_NOTYPE))
1300 if (h->type != STT_NOTYPE
1301 && h->type != ELF_ST_TYPE (sym.st_info)
1302 && ! type_change_ok)
1303 (*_bfd_error_handler)
1304 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1305 name, h->type, ELF_ST_TYPE (sym.st_info),
1306 bfd_get_filename (abfd));
1308 h->type = ELF_ST_TYPE (sym.st_info);
1311 if (sym.st_other != 0
1312 && (definition || h->other == 0))
1313 h->other = sym.st_other;
1315 /* Set a flag in the hash table entry indicating the type of
1316 reference or definition we just found. Keep a count of
1317 the number of dynamic symbols we find. A dynamic symbol
1318 is one which is referenced or defined by both a regular
1319 object and a shared object. */
1320 old_flags = h->elf_link_hash_flags;
1321 dynsym = false;
1322 if (! dynamic)
1324 if (! definition)
1326 new_flag = ELF_LINK_HASH_REF_REGULAR;
1327 if (bind != STB_WEAK)
1328 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1330 else
1331 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1332 if (info->shared
1333 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1334 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1335 dynsym = true;
1337 else
1339 if (! definition)
1340 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1341 else
1342 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1343 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1344 | ELF_LINK_HASH_REF_REGULAR)) != 0
1345 || (h->weakdef != NULL
1346 && ! new_weakdef
1347 && h->weakdef->dynindx != -1))
1348 dynsym = true;
1351 h->elf_link_hash_flags |= new_flag;
1353 /* If this symbol has a version, and it is the default
1354 version, we create an indirect symbol from the default
1355 name to the fully decorated name. This will cause
1356 external references which do not specify a version to be
1357 bound to this version of the symbol. */
1358 if (definition)
1360 char *p;
1362 p = strchr (name, ELF_VER_CHR);
1363 if (p != NULL && p[1] == ELF_VER_CHR)
1365 char *shortname;
1366 struct elf_link_hash_entry *hi;
1367 boolean override;
1369 shortname = bfd_hash_allocate (&info->hash->table,
1370 p - name + 1);
1371 if (shortname == NULL)
1372 goto error_return;
1373 strncpy (shortname, name, p - name);
1374 shortname[p - name] = '\0';
1376 /* We are going to create a new symbol. Merge it
1377 with any existing symbol with this name. For the
1378 purposes of the merge, act as though we were
1379 defining the symbol we just defined, although we
1380 actually going to define an indirect symbol. */
1381 type_change_ok = false;
1382 size_change_ok = false;
1383 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1384 &value, &hi, &override,
1385 &type_change_ok, &size_change_ok))
1386 goto error_return;
1388 if (! override)
1390 if (! (_bfd_generic_link_add_one_symbol
1391 (info, abfd, shortname, BSF_INDIRECT,
1392 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1393 collect, (struct bfd_link_hash_entry **) &hi)))
1394 goto error_return;
1396 else
1398 /* In this case the symbol named SHORTNAME is
1399 overriding the indirect symbol we want to
1400 add. We were planning on making SHORTNAME an
1401 indirect symbol referring to NAME. SHORTNAME
1402 is the name without a version. NAME is the
1403 fully versioned name, and it is the default
1404 version.
1406 Overriding means that we already saw a
1407 definition for the symbol SHORTNAME in a
1408 regular object, and it is overriding the
1409 symbol defined in the dynamic object.
1411 When this happens, we actually want to change
1412 NAME, the symbol we just added, to refer to
1413 SHORTNAME. This will cause references to
1414 NAME in the shared object to become
1415 references to SHORTNAME in the regular
1416 object. This is what we expect when we
1417 override a function in a shared object: that
1418 the references in the shared object will be
1419 mapped to the definition in the regular
1420 object. */
1422 while (hi->root.type == bfd_link_hash_indirect
1423 || hi->root.type == bfd_link_hash_warning)
1424 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1426 h->root.type = bfd_link_hash_indirect;
1427 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1428 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1430 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1431 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1432 if (hi->elf_link_hash_flags
1433 & (ELF_LINK_HASH_REF_REGULAR
1434 | ELF_LINK_HASH_DEF_REGULAR))
1436 if (! _bfd_elf_link_record_dynamic_symbol (info,
1437 hi))
1438 goto error_return;
1442 /* Now set HI to H, so that the following code
1443 will set the other fields correctly. */
1444 hi = h;
1447 /* If there is a duplicate definition somewhere,
1448 then HI may not point to an indirect symbol. We
1449 will have reported an error to the user in that
1450 case. */
1452 if (hi->root.type == bfd_link_hash_indirect)
1454 struct elf_link_hash_entry *ht;
1456 /* If the symbol became indirect, then we assume
1457 that we have not seen a definition before. */
1458 BFD_ASSERT ((hi->elf_link_hash_flags
1459 & (ELF_LINK_HASH_DEF_DYNAMIC
1460 | ELF_LINK_HASH_DEF_REGULAR))
1461 == 0);
1463 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1465 /* Copy down any references that we may have
1466 already seen to the symbol which just became
1467 indirect. */
1468 ht->elf_link_hash_flags |=
1469 (hi->elf_link_hash_flags
1470 & (ELF_LINK_HASH_REF_DYNAMIC
1471 | ELF_LINK_HASH_REF_REGULAR
1472 | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
1474 /* Copy over the global and procedure linkage table
1475 offset entries. These may have been already set
1476 up by a check_relocs routine. */
1477 if (ht->got.offset == (bfd_vma) -1)
1479 ht->got.offset = hi->got.offset;
1480 hi->got.offset = (bfd_vma) -1;
1482 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1484 if (ht->plt.offset == (bfd_vma) -1)
1486 ht->plt.offset = hi->plt.offset;
1487 hi->plt.offset = (bfd_vma) -1;
1489 BFD_ASSERT (hi->plt.offset == (bfd_vma) -1);
1491 if (ht->dynindx == -1)
1493 ht->dynindx = hi->dynindx;
1494 ht->dynstr_index = hi->dynstr_index;
1495 hi->dynindx = -1;
1496 hi->dynstr_index = 0;
1498 BFD_ASSERT (hi->dynindx == -1);
1500 /* FIXME: There may be other information to copy
1501 over for particular targets. */
1503 /* See if the new flags lead us to realize that
1504 the symbol must be dynamic. */
1505 if (! dynsym)
1507 if (! dynamic)
1509 if (info->shared
1510 || ((hi->elf_link_hash_flags
1511 & ELF_LINK_HASH_REF_DYNAMIC)
1512 != 0))
1513 dynsym = true;
1515 else
1517 if ((hi->elf_link_hash_flags
1518 & ELF_LINK_HASH_REF_REGULAR) != 0)
1519 dynsym = true;
1524 /* We also need to define an indirection from the
1525 nondefault version of the symbol. */
1527 shortname = bfd_hash_allocate (&info->hash->table,
1528 strlen (name));
1529 if (shortname == NULL)
1530 goto error_return;
1531 strncpy (shortname, name, p - name);
1532 strcpy (shortname + (p - name), p + 1);
1534 /* Once again, merge with any existing symbol. */
1535 type_change_ok = false;
1536 size_change_ok = false;
1537 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1538 &value, &hi, &override,
1539 &type_change_ok, &size_change_ok))
1540 goto error_return;
1542 if (override)
1544 /* Here SHORTNAME is a versioned name, so we
1545 don't expect to see the type of override we
1546 do in the case above. */
1547 (*_bfd_error_handler)
1548 (_("%s: warning: unexpected redefinition of `%s'"),
1549 bfd_get_filename (abfd), shortname);
1551 else
1553 if (! (_bfd_generic_link_add_one_symbol
1554 (info, abfd, shortname, BSF_INDIRECT,
1555 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1556 collect, (struct bfd_link_hash_entry **) &hi)))
1557 goto error_return;
1559 /* If there is a duplicate definition somewhere,
1560 then HI may not point to an indirect symbol.
1561 We will have reported an error to the user in
1562 that case. */
1564 if (hi->root.type == bfd_link_hash_indirect)
1566 /* If the symbol became indirect, then we
1567 assume that we have not seen a definition
1568 before. */
1569 BFD_ASSERT ((hi->elf_link_hash_flags
1570 & (ELF_LINK_HASH_DEF_DYNAMIC
1571 | ELF_LINK_HASH_DEF_REGULAR))
1572 == 0);
1574 /* Copy down any references that we may have
1575 already seen to the symbol which just
1576 became indirect. */
1577 h->elf_link_hash_flags |=
1578 (hi->elf_link_hash_flags
1579 & (ELF_LINK_HASH_REF_DYNAMIC
1580 | ELF_LINK_HASH_REF_REGULAR
1581 | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
1583 /* Copy over the global and procedure linkage
1584 table offset entries. These may have been
1585 already set up by a check_relocs routine. */
1586 if (h->got.offset == (bfd_vma) -1)
1588 h->got.offset = hi->got.offset;
1589 hi->got.offset = (bfd_vma) -1;
1591 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1593 if (h->plt.offset == (bfd_vma) -1)
1595 h->plt.offset = hi->plt.offset;
1596 hi->plt.offset = (bfd_vma) -1;
1598 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1600 if (h->dynindx == -1)
1602 h->dynindx = hi->dynindx;
1603 h->dynstr_index = hi->dynstr_index;
1604 hi->dynindx = -1;
1605 hi->dynstr_index = 0;
1607 BFD_ASSERT (hi->dynindx == -1);
1609 /* FIXME: There may be other information to
1610 copy over for particular targets. */
1612 /* See if the new flags lead us to realize
1613 that the symbol must be dynamic. */
1614 if (! dynsym)
1616 if (! dynamic)
1618 if (info->shared
1619 || ((hi->elf_link_hash_flags
1620 & ELF_LINK_HASH_REF_DYNAMIC)
1621 != 0))
1622 dynsym = true;
1624 else
1626 if ((hi->elf_link_hash_flags
1627 & ELF_LINK_HASH_REF_REGULAR) != 0)
1628 dynsym = true;
1636 if (dynsym && h->dynindx == -1)
1638 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1639 goto error_return;
1640 if (h->weakdef != NULL
1641 && ! new_weakdef
1642 && h->weakdef->dynindx == -1)
1644 if (! _bfd_elf_link_record_dynamic_symbol (info,
1645 h->weakdef))
1646 goto error_return;
1652 /* Now set the weakdefs field correctly for all the weak defined
1653 symbols we found. The only way to do this is to search all the
1654 symbols. Since we only need the information for non functions in
1655 dynamic objects, that's the only time we actually put anything on
1656 the list WEAKS. We need this information so that if a regular
1657 object refers to a symbol defined weakly in a dynamic object, the
1658 real symbol in the dynamic object is also put in the dynamic
1659 symbols; we also must arrange for both symbols to point to the
1660 same memory location. We could handle the general case of symbol
1661 aliasing, but a general symbol alias can only be generated in
1662 assembler code, handling it correctly would be very time
1663 consuming, and other ELF linkers don't handle general aliasing
1664 either. */
1665 while (weaks != NULL)
1667 struct elf_link_hash_entry *hlook;
1668 asection *slook;
1669 bfd_vma vlook;
1670 struct elf_link_hash_entry **hpp;
1671 struct elf_link_hash_entry **hppend;
1673 hlook = weaks;
1674 weaks = hlook->weakdef;
1675 hlook->weakdef = NULL;
1677 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
1678 || hlook->root.type == bfd_link_hash_defweak
1679 || hlook->root.type == bfd_link_hash_common
1680 || hlook->root.type == bfd_link_hash_indirect);
1681 slook = hlook->root.u.def.section;
1682 vlook = hlook->root.u.def.value;
1684 hpp = elf_sym_hashes (abfd);
1685 hppend = hpp + extsymcount;
1686 for (; hpp < hppend; hpp++)
1688 struct elf_link_hash_entry *h;
1690 h = *hpp;
1691 if (h != NULL && h != hlook
1692 && h->root.type == bfd_link_hash_defined
1693 && h->root.u.def.section == slook
1694 && h->root.u.def.value == vlook)
1696 hlook->weakdef = h;
1698 /* If the weak definition is in the list of dynamic
1699 symbols, make sure the real definition is put there
1700 as well. */
1701 if (hlook->dynindx != -1
1702 && h->dynindx == -1)
1704 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1705 goto error_return;
1708 /* If the real definition is in the list of dynamic
1709 symbols, make sure the weak definition is put there
1710 as well. If we don't do this, then the dynamic
1711 loader might not merge the entries for the real
1712 definition and the weak definition. */
1713 if (h->dynindx != -1
1714 && hlook->dynindx == -1)
1716 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
1717 goto error_return;
1720 break;
1725 if (buf != NULL)
1727 free (buf);
1728 buf = NULL;
1731 if (extversym != NULL)
1733 free (extversym);
1734 extversym = NULL;
1737 /* If this object is the same format as the output object, and it is
1738 not a shared library, then let the backend look through the
1739 relocs.
1741 This is required to build global offset table entries and to
1742 arrange for dynamic relocs. It is not required for the
1743 particular common case of linking non PIC code, even when linking
1744 against shared libraries, but unfortunately there is no way of
1745 knowing whether an object file has been compiled PIC or not.
1746 Looking through the relocs is not particularly time consuming.
1747 The problem is that we must either (1) keep the relocs in memory,
1748 which causes the linker to require additional runtime memory or
1749 (2) read the relocs twice from the input file, which wastes time.
1750 This would be a good case for using mmap.
1752 I have no idea how to handle linking PIC code into a file of a
1753 different format. It probably can't be done. */
1754 check_relocs = get_elf_backend_data (abfd)->check_relocs;
1755 if (! dynamic
1756 && abfd->xvec == info->hash->creator
1757 && check_relocs != NULL)
1759 asection *o;
1761 for (o = abfd->sections; o != NULL; o = o->next)
1763 Elf_Internal_Rela *internal_relocs;
1764 boolean ok;
1766 if ((o->flags & SEC_RELOC) == 0
1767 || o->reloc_count == 0
1768 || ((info->strip == strip_all || info->strip == strip_debugger)
1769 && (o->flags & SEC_DEBUGGING) != 0)
1770 || bfd_is_abs_section (o->output_section))
1771 continue;
1773 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
1774 (abfd, o, (PTR) NULL,
1775 (Elf_Internal_Rela *) NULL,
1776 info->keep_memory));
1777 if (internal_relocs == NULL)
1778 goto error_return;
1780 ok = (*check_relocs) (abfd, info, o, internal_relocs);
1782 if (! info->keep_memory)
1783 free (internal_relocs);
1785 if (! ok)
1786 goto error_return;
1790 /* If this is a non-traditional, non-relocateable link, try to
1791 optimize the handling of the .stab/.stabstr sections. */
1792 if (! dynamic
1793 && ! info->relocateable
1794 && ! info->traditional_format
1795 && info->hash->creator->flavour == bfd_target_elf_flavour
1796 && (info->strip != strip_all && info->strip != strip_debugger))
1798 asection *stab, *stabstr;
1800 stab = bfd_get_section_by_name (abfd, ".stab");
1801 if (stab != NULL)
1803 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
1805 if (stabstr != NULL)
1807 struct bfd_elf_section_data *secdata;
1809 secdata = elf_section_data (stab);
1810 if (! _bfd_link_section_stabs (abfd,
1811 &elf_hash_table (info)->stab_info,
1812 stab, stabstr,
1813 &secdata->stab_info))
1814 goto error_return;
1819 return true;
1821 error_return:
1822 if (buf != NULL)
1823 free (buf);
1824 if (dynbuf != NULL)
1825 free (dynbuf);
1826 if (dynver != NULL)
1827 free (dynver);
1828 if (extversym != NULL)
1829 free (extversym);
1830 return false;
1833 /* Create some sections which will be filled in with dynamic linking
1834 information. ABFD is an input file which requires dynamic sections
1835 to be created. The dynamic sections take up virtual memory space
1836 when the final executable is run, so we need to create them before
1837 addresses are assigned to the output sections. We work out the
1838 actual contents and size of these sections later. */
1840 boolean
1841 elf_link_create_dynamic_sections (abfd, info)
1842 bfd *abfd;
1843 struct bfd_link_info *info;
1845 flagword flags;
1846 register asection *s;
1847 struct elf_link_hash_entry *h;
1848 struct elf_backend_data *bed;
1850 if (elf_hash_table (info)->dynamic_sections_created)
1851 return true;
1853 /* Make sure that all dynamic sections use the same input BFD. */
1854 if (elf_hash_table (info)->dynobj == NULL)
1855 elf_hash_table (info)->dynobj = abfd;
1856 else
1857 abfd = elf_hash_table (info)->dynobj;
1859 /* Note that we set the SEC_IN_MEMORY flag for all of these
1860 sections. */
1861 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
1862 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
1864 /* A dynamically linked executable has a .interp section, but a
1865 shared library does not. */
1866 if (! info->shared)
1868 s = bfd_make_section (abfd, ".interp");
1869 if (s == NULL
1870 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
1871 return false;
1874 /* Create sections to hold version informations. These are removed
1875 if they are not needed. */
1876 s = bfd_make_section (abfd, ".gnu.version_d");
1877 if (s == NULL
1878 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1879 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1880 return false;
1882 s = bfd_make_section (abfd, ".gnu.version");
1883 if (s == NULL
1884 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1885 || ! bfd_set_section_alignment (abfd, s, 1))
1886 return false;
1888 s = bfd_make_section (abfd, ".gnu.version_r");
1889 if (s == NULL
1890 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1891 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1892 return false;
1894 s = bfd_make_section (abfd, ".dynsym");
1895 if (s == NULL
1896 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1897 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1898 return false;
1900 s = bfd_make_section (abfd, ".dynstr");
1901 if (s == NULL
1902 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
1903 return false;
1905 /* Create a strtab to hold the dynamic symbol names. */
1906 if (elf_hash_table (info)->dynstr == NULL)
1908 elf_hash_table (info)->dynstr = elf_stringtab_init ();
1909 if (elf_hash_table (info)->dynstr == NULL)
1910 return false;
1913 s = bfd_make_section (abfd, ".dynamic");
1914 if (s == NULL
1915 || ! bfd_set_section_flags (abfd, s, flags)
1916 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1917 return false;
1919 /* The special symbol _DYNAMIC is always set to the start of the
1920 .dynamic section. This call occurs before we have processed the
1921 symbols for any dynamic object, so we don't have to worry about
1922 overriding a dynamic definition. We could set _DYNAMIC in a
1923 linker script, but we only want to define it if we are, in fact,
1924 creating a .dynamic section. We don't want to define it if there
1925 is no .dynamic section, since on some ELF platforms the start up
1926 code examines it to decide how to initialize the process. */
1927 h = NULL;
1928 if (! (_bfd_generic_link_add_one_symbol
1929 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
1930 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
1931 (struct bfd_link_hash_entry **) &h)))
1932 return false;
1933 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1934 h->type = STT_OBJECT;
1936 if (info->shared
1937 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
1938 return false;
1940 s = bfd_make_section (abfd, ".hash");
1941 if (s == NULL
1942 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1943 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1944 return false;
1946 /* Let the backend create the rest of the sections. This lets the
1947 backend set the right flags. The backend will normally create
1948 the .got and .plt sections. */
1949 bed = get_elf_backend_data (abfd);
1950 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
1951 return false;
1953 elf_hash_table (info)->dynamic_sections_created = true;
1955 return true;
1958 /* Add an entry to the .dynamic table. */
1960 boolean
1961 elf_add_dynamic_entry (info, tag, val)
1962 struct bfd_link_info *info;
1963 bfd_vma tag;
1964 bfd_vma val;
1966 Elf_Internal_Dyn dyn;
1967 bfd *dynobj;
1968 asection *s;
1969 size_t newsize;
1970 bfd_byte *newcontents;
1972 dynobj = elf_hash_table (info)->dynobj;
1974 s = bfd_get_section_by_name (dynobj, ".dynamic");
1975 BFD_ASSERT (s != NULL);
1977 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
1978 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
1979 if (newcontents == NULL)
1980 return false;
1982 dyn.d_tag = tag;
1983 dyn.d_un.d_val = val;
1984 elf_swap_dyn_out (dynobj, &dyn,
1985 (Elf_External_Dyn *) (newcontents + s->_raw_size));
1987 s->_raw_size = newsize;
1988 s->contents = newcontents;
1990 return true;
1994 /* Read and swap the relocs for a section. They may have been cached.
1995 If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL,
1996 they are used as buffers to read into. They are known to be large
1997 enough. If the INTERNAL_RELOCS relocs argument is NULL, the return
1998 value is allocated using either malloc or bfd_alloc, according to
1999 the KEEP_MEMORY argument. */
2001 Elf_Internal_Rela *
2002 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2003 keep_memory)
2004 bfd *abfd;
2005 asection *o;
2006 PTR external_relocs;
2007 Elf_Internal_Rela *internal_relocs;
2008 boolean keep_memory;
2010 Elf_Internal_Shdr *rel_hdr;
2011 PTR alloc1 = NULL;
2012 Elf_Internal_Rela *alloc2 = NULL;
2014 if (elf_section_data (o)->relocs != NULL)
2015 return elf_section_data (o)->relocs;
2017 if (o->reloc_count == 0)
2018 return NULL;
2020 rel_hdr = &elf_section_data (o)->rel_hdr;
2022 if (internal_relocs == NULL)
2024 size_t size;
2026 size = o->reloc_count * sizeof (Elf_Internal_Rela);
2027 if (keep_memory)
2028 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2029 else
2030 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2031 if (internal_relocs == NULL)
2032 goto error_return;
2035 if (external_relocs == NULL)
2037 alloc1 = (PTR) bfd_malloc ((size_t) rel_hdr->sh_size);
2038 if (alloc1 == NULL)
2039 goto error_return;
2040 external_relocs = alloc1;
2043 if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
2044 || (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd)
2045 != rel_hdr->sh_size))
2046 goto error_return;
2048 /* Swap in the relocs. For convenience, we always produce an
2049 Elf_Internal_Rela array; if the relocs are Rel, we set the addend
2050 to 0. */
2051 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
2053 Elf_External_Rel *erel;
2054 Elf_External_Rel *erelend;
2055 Elf_Internal_Rela *irela;
2057 erel = (Elf_External_Rel *) external_relocs;
2058 erelend = erel + o->reloc_count;
2059 irela = internal_relocs;
2060 for (; erel < erelend; erel++, irela++)
2062 Elf_Internal_Rel irel;
2064 elf_swap_reloc_in (abfd, erel, &irel);
2065 irela->r_offset = irel.r_offset;
2066 irela->r_info = irel.r_info;
2067 irela->r_addend = 0;
2070 else
2072 Elf_External_Rela *erela;
2073 Elf_External_Rela *erelaend;
2074 Elf_Internal_Rela *irela;
2076 BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela));
2078 erela = (Elf_External_Rela *) external_relocs;
2079 erelaend = erela + o->reloc_count;
2080 irela = internal_relocs;
2081 for (; erela < erelaend; erela++, irela++)
2082 elf_swap_reloca_in (abfd, erela, irela);
2085 /* Cache the results for next time, if we can. */
2086 if (keep_memory)
2087 elf_section_data (o)->relocs = internal_relocs;
2089 if (alloc1 != NULL)
2090 free (alloc1);
2092 /* Don't free alloc2, since if it was allocated we are passing it
2093 back (under the name of internal_relocs). */
2095 return internal_relocs;
2097 error_return:
2098 if (alloc1 != NULL)
2099 free (alloc1);
2100 if (alloc2 != NULL)
2101 free (alloc2);
2102 return NULL;
2106 /* Record an assignment to a symbol made by a linker script. We need
2107 this in case some dynamic object refers to this symbol. */
2109 /*ARGSUSED*/
2110 boolean
2111 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2112 bfd *output_bfd;
2113 struct bfd_link_info *info;
2114 const char *name;
2115 boolean provide;
2117 struct elf_link_hash_entry *h;
2119 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2120 return true;
2122 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2123 if (h == NULL)
2124 return false;
2126 if (h->root.type == bfd_link_hash_new)
2127 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2129 /* If this symbol is being provided by the linker script, and it is
2130 currently defined by a dynamic object, but not by a regular
2131 object, then mark it as undefined so that the generic linker will
2132 force the correct value. */
2133 if (provide
2134 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2135 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2136 h->root.type = bfd_link_hash_undefined;
2138 /* If this symbol is not being provided by the linker script, and it is
2139 currently defined by a dynamic object, but not by a regular object,
2140 then clear out any version information because the symbol will not be
2141 associated with the dynamic object any more. */
2142 if (!provide
2143 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2144 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2145 h->verinfo.verdef = NULL;
2147 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2148 h->type = STT_OBJECT;
2150 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2151 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2152 || info->shared)
2153 && h->dynindx == -1)
2155 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2156 return false;
2158 /* If this is a weak defined symbol, and we know a corresponding
2159 real symbol from the same dynamic object, make sure the real
2160 symbol is also made into a dynamic symbol. */
2161 if (h->weakdef != NULL
2162 && h->weakdef->dynindx == -1)
2164 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2165 return false;
2169 return true;
2172 /* This structure is used to pass information to
2173 elf_link_assign_sym_version. */
2175 struct elf_assign_sym_version_info
2177 /* Output BFD. */
2178 bfd *output_bfd;
2179 /* General link information. */
2180 struct bfd_link_info *info;
2181 /* Version tree. */
2182 struct bfd_elf_version_tree *verdefs;
2183 /* Whether we are exporting all dynamic symbols. */
2184 boolean export_dynamic;
2185 /* Whether we removed any symbols from the dynamic symbol table. */
2186 boolean removed_dynamic;
2187 /* Whether we had a failure. */
2188 boolean failed;
2191 /* This structure is used to pass information to
2192 elf_link_find_version_dependencies. */
2194 struct elf_find_verdep_info
2196 /* Output BFD. */
2197 bfd *output_bfd;
2198 /* General link information. */
2199 struct bfd_link_info *info;
2200 /* The number of dependencies. */
2201 unsigned int vers;
2202 /* Whether we had a failure. */
2203 boolean failed;
2206 /* Array used to determine the number of hash table buckets to use
2207 based on the number of symbols there are. If there are fewer than
2208 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2209 fewer than 37 we use 17 buckets, and so forth. We never use more
2210 than 32771 buckets. */
2212 static const size_t elf_buckets[] =
2214 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2215 16411, 32771, 0
2218 /* Compute bucket count for hashing table. We do not use a static set
2219 of possible tables sizes anymore. Instead we determine for all
2220 possible reasonable sizes of the table the outcome (i.e., the
2221 number of collisions etc) and choose the best solution. The
2222 weighting functions are not too simple to allow the table to grow
2223 without bounds. Instead one of the weighting factors is the size.
2224 Therefore the result is always a good payoff between few collisions
2225 (= short chain lengths) and table size. */
2226 static size_t
2227 compute_bucket_count (info)
2228 struct bfd_link_info *info;
2230 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2231 size_t best_size;
2232 unsigned long int *hashcodes;
2233 unsigned long int *hashcodesp;
2234 unsigned long int i;
2236 /* Compute the hash values for all exported symbols. At the same
2237 time store the values in an array so that we could use them for
2238 optimizations. */
2239 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2240 * sizeof (unsigned long int));
2241 if (hashcodes == NULL)
2242 return 0;
2243 hashcodesp = hashcodes;
2245 /* Put all hash values in HASHCODES. */
2246 elf_link_hash_traverse (elf_hash_table (info),
2247 elf_collect_hash_codes, &hashcodesp);
2249 /* We have a problem here. The following code to optimize the table
2250 size requires an integer type with more the 32 bits. If
2251 BFD_HOST_U_64_BIT is set we know about such a type. */
2252 #ifdef BFD_HOST_U_64_BIT
2253 if (info->optimize == true)
2255 unsigned long int nsyms = hashcodesp - hashcodes;
2256 size_t minsize;
2257 size_t maxsize;
2258 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2259 unsigned long int *counts ;
2261 /* Possible optimization parameters: if we have NSYMS symbols we say
2262 that the hashing table must at least have NSYMS/4 and at most
2263 2*NSYMS buckets. */
2264 minsize = nsyms / 4;
2265 if (minsize == 0)
2266 minsize = 1;
2267 best_size = maxsize = nsyms * 2;
2269 /* Create array where we count the collisions in. We must use bfd_malloc
2270 since the size could be large. */
2271 counts = (unsigned long int *) bfd_malloc (maxsize
2272 * sizeof (unsigned long int));
2273 if (counts == NULL)
2275 free (hashcodes);
2276 return 0;
2279 /* Compute the "optimal" size for the hash table. The criteria is a
2280 minimal chain length. The minor criteria is (of course) the size
2281 of the table. */
2282 for (i = minsize; i < maxsize; ++i)
2284 /* Walk through the array of hashcodes and count the collisions. */
2285 BFD_HOST_U_64_BIT max;
2286 unsigned long int j;
2287 unsigned long int fact;
2289 memset (counts, '\0', i * sizeof (unsigned long int));
2291 /* Determine how often each hash bucket is used. */
2292 for (j = 0; j < nsyms; ++j)
2293 ++counts[hashcodes[j] % i];
2295 /* For the weight function we need some information about the
2296 pagesize on the target. This is information need not be 100%
2297 accurate. Since this information is not available (so far) we
2298 define it here to a reasonable default value. If it is crucial
2299 to have a better value some day simply define this value. */
2300 # ifndef BFD_TARGET_PAGESIZE
2301 # define BFD_TARGET_PAGESIZE (4096)
2302 # endif
2304 /* We in any case need 2 + NSYMS entries for the size values and
2305 the chains. */
2306 max = (2 + nsyms) * (ARCH_SIZE / 8);
2308 # if 1
2309 /* Variant 1: optimize for short chains. We add the squares
2310 of all the chain lengths (which favous many small chain
2311 over a few long chains). */
2312 for (j = 0; j < i; ++j)
2313 max += counts[j] * counts[j];
2315 /* This adds penalties for the overall size of the table. */
2316 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2317 max *= fact * fact;
2318 # else
2319 /* Variant 2: Optimize a lot more for small table. Here we
2320 also add squares of the size but we also add penalties for
2321 empty slots (the +1 term). */
2322 for (j = 0; j < i; ++j)
2323 max += (1 + counts[j]) * (1 + counts[j]);
2325 /* The overall size of the table is considered, but not as
2326 strong as in variant 1, where it is squared. */
2327 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2328 max *= fact;
2329 # endif
2331 /* Compare with current best results. */
2332 if (max < best_chlen)
2334 best_chlen = max;
2335 best_size = i;
2339 free (counts);
2341 else
2342 #endif /* defined (BFD_HOST_U_64_BIT) */
2344 /* This is the fallback solution if no 64bit type is available or if we
2345 are not supposed to spend much time on optimizations. We select the
2346 bucket count using a fixed set of numbers. */
2347 for (i = 0; elf_buckets[i] != 0; i++)
2349 best_size = elf_buckets[i];
2350 if (dynsymcount < elf_buckets[i + 1])
2351 break;
2355 /* Free the arrays we needed. */
2356 free (hashcodes);
2358 return best_size;
2361 /* Set up the sizes and contents of the ELF dynamic sections. This is
2362 called by the ELF linker emulation before_allocation routine. We
2363 must set the sizes of the sections before the linker sets the
2364 addresses of the various sections. */
2366 boolean
2367 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2368 export_dynamic, filter_shlib,
2369 auxiliary_filters, info, sinterpptr,
2370 verdefs)
2371 bfd *output_bfd;
2372 const char *soname;
2373 const char *rpath;
2374 boolean export_dynamic;
2375 const char *filter_shlib;
2376 const char * const *auxiliary_filters;
2377 struct bfd_link_info *info;
2378 asection **sinterpptr;
2379 struct bfd_elf_version_tree *verdefs;
2381 bfd_size_type soname_indx;
2382 bfd *dynobj;
2383 struct elf_backend_data *bed;
2384 bfd_size_type old_dynsymcount;
2385 struct elf_assign_sym_version_info asvinfo;
2387 *sinterpptr = NULL;
2389 soname_indx = (bfd_size_type) -1;
2391 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2392 return true;
2394 /* The backend may have to create some sections regardless of whether
2395 we're dynamic or not. */
2396 bed = get_elf_backend_data (output_bfd);
2397 if (bed->elf_backend_always_size_sections
2398 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2399 return false;
2401 dynobj = elf_hash_table (info)->dynobj;
2403 /* If there were no dynamic objects in the link, there is nothing to
2404 do here. */
2405 if (dynobj == NULL)
2406 return true;
2408 /* If we are supposed to export all symbols into the dynamic symbol
2409 table (this is not the normal case), then do so. */
2410 if (export_dynamic)
2412 struct elf_info_failed eif;
2414 eif.failed = false;
2415 eif.info = info;
2416 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2417 (PTR) &eif);
2418 if (eif.failed)
2419 return false;
2422 if (elf_hash_table (info)->dynamic_sections_created)
2424 struct elf_info_failed eif;
2425 struct elf_link_hash_entry *h;
2426 bfd_size_type strsize;
2428 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2429 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2431 if (soname != NULL)
2433 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2434 soname, true, true);
2435 if (soname_indx == (bfd_size_type) -1
2436 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2437 return false;
2440 if (info->symbolic)
2442 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2443 return false;
2446 if (rpath != NULL)
2448 bfd_size_type indx;
2450 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2451 true, true);
2452 if (indx == (bfd_size_type) -1
2453 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
2454 return false;
2457 if (filter_shlib != NULL)
2459 bfd_size_type indx;
2461 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2462 filter_shlib, true, true);
2463 if (indx == (bfd_size_type) -1
2464 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2465 return false;
2468 if (auxiliary_filters != NULL)
2470 const char * const *p;
2472 for (p = auxiliary_filters; *p != NULL; p++)
2474 bfd_size_type indx;
2476 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2477 *p, true, true);
2478 if (indx == (bfd_size_type) -1
2479 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2480 return false;
2484 /* Attach all the symbols to their version information. */
2485 asvinfo.output_bfd = output_bfd;
2486 asvinfo.info = info;
2487 asvinfo.verdefs = verdefs;
2488 asvinfo.export_dynamic = export_dynamic;
2489 asvinfo.removed_dynamic = false;
2490 asvinfo.failed = false;
2492 elf_link_hash_traverse (elf_hash_table (info),
2493 elf_link_assign_sym_version,
2494 (PTR) &asvinfo);
2495 if (asvinfo.failed)
2496 return false;
2498 /* Find all symbols which were defined in a dynamic object and make
2499 the backend pick a reasonable value for them. */
2500 eif.failed = false;
2501 eif.info = info;
2502 elf_link_hash_traverse (elf_hash_table (info),
2503 elf_adjust_dynamic_symbol,
2504 (PTR) &eif);
2505 if (eif.failed)
2506 return false;
2508 /* Add some entries to the .dynamic section. We fill in some of the
2509 values later, in elf_bfd_final_link, but we must add the entries
2510 now so that we know the final size of the .dynamic section. */
2511 h = elf_link_hash_lookup (elf_hash_table (info), "_init", false,
2512 false, false);
2513 if (h != NULL
2514 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2515 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2517 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2518 return false;
2520 h = elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
2521 false, false);
2522 if (h != NULL
2523 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2524 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2526 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2527 return false;
2529 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2530 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2531 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2532 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2533 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2534 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2535 sizeof (Elf_External_Sym)))
2536 return false;
2539 /* The backend must work out the sizes of all the other dynamic
2540 sections. */
2541 old_dynsymcount = elf_hash_table (info)->dynsymcount;
2542 if (bed->elf_backend_size_dynamic_sections
2543 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2544 return false;
2546 if (elf_hash_table (info)->dynamic_sections_created)
2548 size_t dynsymcount;
2549 asection *s;
2550 size_t bucketcount = 0;
2551 Elf_Internal_Sym isym;
2553 /* Set up the version definition section. */
2554 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2555 BFD_ASSERT (s != NULL);
2557 /* We may have created additional version definitions if we are
2558 just linking a regular application. */
2559 verdefs = asvinfo.verdefs;
2561 if (verdefs == NULL)
2563 asection **spp;
2565 /* Don't include this section in the output file. */
2566 for (spp = &output_bfd->sections;
2567 *spp != s->output_section;
2568 spp = &(*spp)->next)
2570 *spp = s->output_section->next;
2571 --output_bfd->section_count;
2573 else
2575 unsigned int cdefs;
2576 bfd_size_type size;
2577 struct bfd_elf_version_tree *t;
2578 bfd_byte *p;
2579 Elf_Internal_Verdef def;
2580 Elf_Internal_Verdaux defaux;
2582 if (asvinfo.removed_dynamic)
2584 /* Some dynamic symbols were changed to be local
2585 symbols. In this case, we renumber all of the
2586 dynamic symbols, so that we don't have a hole. If
2587 the backend changed dynsymcount, then assume that the
2588 new symbols are at the start. This is the case on
2589 the MIPS. FIXME: The names of the removed symbols
2590 will still be in the dynamic string table, wasting
2591 space. */
2592 elf_hash_table (info)->dynsymcount =
2593 1 + (elf_hash_table (info)->dynsymcount - old_dynsymcount);
2594 elf_link_hash_traverse (elf_hash_table (info),
2595 elf_link_renumber_dynsyms,
2596 (PTR) info);
2599 cdefs = 0;
2600 size = 0;
2602 /* Make space for the base version. */
2603 size += sizeof (Elf_External_Verdef);
2604 size += sizeof (Elf_External_Verdaux);
2605 ++cdefs;
2607 for (t = verdefs; t != NULL; t = t->next)
2609 struct bfd_elf_version_deps *n;
2611 size += sizeof (Elf_External_Verdef);
2612 size += sizeof (Elf_External_Verdaux);
2613 ++cdefs;
2615 for (n = t->deps; n != NULL; n = n->next)
2616 size += sizeof (Elf_External_Verdaux);
2619 s->_raw_size = size;
2620 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2621 if (s->contents == NULL && s->_raw_size != 0)
2622 return false;
2624 /* Fill in the version definition section. */
2626 p = s->contents;
2628 def.vd_version = VER_DEF_CURRENT;
2629 def.vd_flags = VER_FLG_BASE;
2630 def.vd_ndx = 1;
2631 def.vd_cnt = 1;
2632 def.vd_aux = sizeof (Elf_External_Verdef);
2633 def.vd_next = (sizeof (Elf_External_Verdef)
2634 + sizeof (Elf_External_Verdaux));
2636 if (soname_indx != (bfd_size_type) -1)
2638 def.vd_hash = bfd_elf_hash ((const unsigned char *) soname);
2639 defaux.vda_name = soname_indx;
2641 else
2643 const char *name;
2644 bfd_size_type indx;
2646 name = output_bfd->filename;
2647 def.vd_hash = bfd_elf_hash ((const unsigned char *) name);
2648 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2649 name, true, false);
2650 if (indx == (bfd_size_type) -1)
2651 return false;
2652 defaux.vda_name = indx;
2654 defaux.vda_next = 0;
2656 _bfd_elf_swap_verdef_out (output_bfd, &def,
2657 (Elf_External_Verdef *)p);
2658 p += sizeof (Elf_External_Verdef);
2659 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2660 (Elf_External_Verdaux *) p);
2661 p += sizeof (Elf_External_Verdaux);
2663 for (t = verdefs; t != NULL; t = t->next)
2665 unsigned int cdeps;
2666 struct bfd_elf_version_deps *n;
2667 struct elf_link_hash_entry *h;
2669 cdeps = 0;
2670 for (n = t->deps; n != NULL; n = n->next)
2671 ++cdeps;
2673 /* Add a symbol representing this version. */
2674 h = NULL;
2675 if (! (_bfd_generic_link_add_one_symbol
2676 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
2677 (bfd_vma) 0, (const char *) NULL, false,
2678 get_elf_backend_data (dynobj)->collect,
2679 (struct bfd_link_hash_entry **) &h)))
2680 return false;
2681 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
2682 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2683 h->type = STT_OBJECT;
2684 h->verinfo.vertree = t;
2686 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2687 return false;
2689 def.vd_version = VER_DEF_CURRENT;
2690 def.vd_flags = 0;
2691 if (t->globals == NULL && t->locals == NULL && ! t->used)
2692 def.vd_flags |= VER_FLG_WEAK;
2693 def.vd_ndx = t->vernum + 1;
2694 def.vd_cnt = cdeps + 1;
2695 def.vd_hash = bfd_elf_hash ((const unsigned char *) t->name);
2696 def.vd_aux = sizeof (Elf_External_Verdef);
2697 if (t->next != NULL)
2698 def.vd_next = (sizeof (Elf_External_Verdef)
2699 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
2700 else
2701 def.vd_next = 0;
2703 _bfd_elf_swap_verdef_out (output_bfd, &def,
2704 (Elf_External_Verdef *) p);
2705 p += sizeof (Elf_External_Verdef);
2707 defaux.vda_name = h->dynstr_index;
2708 if (t->deps == NULL)
2709 defaux.vda_next = 0;
2710 else
2711 defaux.vda_next = sizeof (Elf_External_Verdaux);
2712 t->name_indx = defaux.vda_name;
2714 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2715 (Elf_External_Verdaux *) p);
2716 p += sizeof (Elf_External_Verdaux);
2718 for (n = t->deps; n != NULL; n = n->next)
2720 if (n->version_needed == NULL)
2722 /* This can happen if there was an error in the
2723 version script. */
2724 defaux.vda_name = 0;
2726 else
2727 defaux.vda_name = n->version_needed->name_indx;
2728 if (n->next == NULL)
2729 defaux.vda_next = 0;
2730 else
2731 defaux.vda_next = sizeof (Elf_External_Verdaux);
2733 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2734 (Elf_External_Verdaux *) p);
2735 p += sizeof (Elf_External_Verdaux);
2739 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
2740 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
2741 return false;
2743 elf_tdata (output_bfd)->cverdefs = cdefs;
2746 /* Work out the size of the version reference section. */
2748 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
2749 BFD_ASSERT (s != NULL);
2751 struct elf_find_verdep_info sinfo;
2753 sinfo.output_bfd = output_bfd;
2754 sinfo.info = info;
2755 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
2756 if (sinfo.vers == 0)
2757 sinfo.vers = 1;
2758 sinfo.failed = false;
2760 elf_link_hash_traverse (elf_hash_table (info),
2761 elf_link_find_version_dependencies,
2762 (PTR) &sinfo);
2764 if (elf_tdata (output_bfd)->verref == NULL)
2766 asection **spp;
2768 /* We don't have any version definitions, so we can just
2769 remove the section. */
2771 for (spp = &output_bfd->sections;
2772 *spp != s->output_section;
2773 spp = &(*spp)->next)
2775 *spp = s->output_section->next;
2776 --output_bfd->section_count;
2778 else
2780 Elf_Internal_Verneed *t;
2781 unsigned int size;
2782 unsigned int crefs;
2783 bfd_byte *p;
2785 /* Build the version definition section. */
2786 size = 0;
2787 crefs = 0;
2788 for (t = elf_tdata (output_bfd)->verref;
2789 t != NULL;
2790 t = t->vn_nextref)
2792 Elf_Internal_Vernaux *a;
2794 size += sizeof (Elf_External_Verneed);
2795 ++crefs;
2796 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2797 size += sizeof (Elf_External_Vernaux);
2800 s->_raw_size = size;
2801 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
2802 if (s->contents == NULL)
2803 return false;
2805 p = s->contents;
2806 for (t = elf_tdata (output_bfd)->verref;
2807 t != NULL;
2808 t = t->vn_nextref)
2810 unsigned int caux;
2811 Elf_Internal_Vernaux *a;
2812 bfd_size_type indx;
2814 caux = 0;
2815 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2816 ++caux;
2818 t->vn_version = VER_NEED_CURRENT;
2819 t->vn_cnt = caux;
2820 if (elf_dt_name (t->vn_bfd) != NULL)
2821 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2822 elf_dt_name (t->vn_bfd),
2823 true, false);
2824 else
2825 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2826 t->vn_bfd->filename, true, false);
2827 if (indx == (bfd_size_type) -1)
2828 return false;
2829 t->vn_file = indx;
2830 t->vn_aux = sizeof (Elf_External_Verneed);
2831 if (t->vn_nextref == NULL)
2832 t->vn_next = 0;
2833 else
2834 t->vn_next = (sizeof (Elf_External_Verneed)
2835 + caux * sizeof (Elf_External_Vernaux));
2837 _bfd_elf_swap_verneed_out (output_bfd, t,
2838 (Elf_External_Verneed *) p);
2839 p += sizeof (Elf_External_Verneed);
2841 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2843 a->vna_hash = bfd_elf_hash ((const unsigned char *)
2844 a->vna_nodename);
2845 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2846 a->vna_nodename, true, false);
2847 if (indx == (bfd_size_type) -1)
2848 return false;
2849 a->vna_name = indx;
2850 if (a->vna_nextptr == NULL)
2851 a->vna_next = 0;
2852 else
2853 a->vna_next = sizeof (Elf_External_Vernaux);
2855 _bfd_elf_swap_vernaux_out (output_bfd, a,
2856 (Elf_External_Vernaux *) p);
2857 p += sizeof (Elf_External_Vernaux);
2861 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
2862 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
2863 return false;
2865 elf_tdata (output_bfd)->cverrefs = crefs;
2869 dynsymcount = elf_hash_table (info)->dynsymcount;
2871 /* Work out the size of the symbol version section. */
2872 s = bfd_get_section_by_name (dynobj, ".gnu.version");
2873 BFD_ASSERT (s != NULL);
2874 if (dynsymcount == 0
2875 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
2877 asection **spp;
2879 /* We don't need any symbol versions; just discard the
2880 section. */
2881 for (spp = &output_bfd->sections;
2882 *spp != s->output_section;
2883 spp = &(*spp)->next)
2885 *spp = s->output_section->next;
2886 --output_bfd->section_count;
2888 else
2890 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
2891 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
2892 if (s->contents == NULL)
2893 return false;
2895 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
2896 return false;
2899 /* Set the size of the .dynsym and .hash sections. We counted
2900 the number of dynamic symbols in elf_link_add_object_symbols.
2901 We will build the contents of .dynsym and .hash when we build
2902 the final symbol table, because until then we do not know the
2903 correct value to give the symbols. We built the .dynstr
2904 section as we went along in elf_link_add_object_symbols. */
2905 s = bfd_get_section_by_name (dynobj, ".dynsym");
2906 BFD_ASSERT (s != NULL);
2907 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
2908 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2909 if (s->contents == NULL && s->_raw_size != 0)
2910 return false;
2912 /* The first entry in .dynsym is a dummy symbol. */
2913 isym.st_value = 0;
2914 isym.st_size = 0;
2915 isym.st_name = 0;
2916 isym.st_info = 0;
2917 isym.st_other = 0;
2918 isym.st_shndx = 0;
2919 elf_swap_symbol_out (output_bfd, &isym,
2920 (PTR) (Elf_External_Sym *) s->contents);
2922 /* Compute the size of the hashing table. As a side effect this
2923 computes the hash values for all the names we export. */
2924 bucketcount = compute_bucket_count (info);
2926 s = bfd_get_section_by_name (dynobj, ".hash");
2927 BFD_ASSERT (s != NULL);
2928 s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
2929 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2930 if (s->contents == NULL)
2931 return false;
2932 memset (s->contents, 0, (size_t) s->_raw_size);
2934 put_word (output_bfd, bucketcount, s->contents);
2935 put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
2937 elf_hash_table (info)->bucketcount = bucketcount;
2939 s = bfd_get_section_by_name (dynobj, ".dynstr");
2940 BFD_ASSERT (s != NULL);
2941 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2943 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
2944 return false;
2947 return true;
2950 /* Fix up the flags for a symbol. This handles various cases which
2951 can only be fixed after all the input files are seen. This is
2952 currently called by both adjust_dynamic_symbol and
2953 assign_sym_version, which is unnecessary but perhaps more robust in
2954 the face of future changes. */
2956 static boolean
2957 elf_fix_symbol_flags (h, eif)
2958 struct elf_link_hash_entry *h;
2959 struct elf_info_failed *eif;
2961 /* If this symbol was mentioned in a non-ELF file, try to set
2962 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
2963 permit a non-ELF file to correctly refer to a symbol defined in
2964 an ELF dynamic object. */
2965 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
2967 if (h->root.type != bfd_link_hash_defined
2968 && h->root.type != bfd_link_hash_defweak)
2969 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
2970 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
2971 else
2973 if (h->root.u.def.section->owner != NULL
2974 && (bfd_get_flavour (h->root.u.def.section->owner)
2975 == bfd_target_elf_flavour))
2976 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
2977 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
2978 else
2979 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2982 if (h->dynindx == -1
2983 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2984 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
2986 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
2988 eif->failed = true;
2989 return false;
2993 else
2995 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
2996 was first seen in a non-ELF file. Fortunately, if the symbol
2997 was first seen in an ELF file, we're probably OK unless the
2998 symbol was defined in a non-ELF file. Catch that case here.
2999 FIXME: We're still in trouble if the symbol was first seen in
3000 a dynamic object, and then later in a non-ELF regular object. */
3001 if ((h->root.type == bfd_link_hash_defined
3002 || h->root.type == bfd_link_hash_defweak)
3003 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3004 && (h->root.u.def.section->owner != NULL
3005 ? (bfd_get_flavour (h->root.u.def.section->owner)
3006 != bfd_target_elf_flavour)
3007 : (bfd_is_abs_section (h->root.u.def.section)
3008 && (h->elf_link_hash_flags
3009 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3010 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3013 /* If this is a final link, and the symbol was defined as a common
3014 symbol in a regular object file, and there was no definition in
3015 any dynamic object, then the linker will have allocated space for
3016 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3017 flag will not have been set. */
3018 if (h->root.type == bfd_link_hash_defined
3019 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3020 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3021 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3022 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3023 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3025 /* If -Bsymbolic was used (which means to bind references to global
3026 symbols to the definition within the shared object), and this
3027 symbol was defined in a regular object, then it actually doesn't
3028 need a PLT entry. */
3029 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3030 && eif->info->shared
3031 && eif->info->symbolic
3032 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3034 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3035 h->plt.offset = (bfd_vma) -1;
3038 return true;
3041 /* Make the backend pick a good value for a dynamic symbol. This is
3042 called via elf_link_hash_traverse, and also calls itself
3043 recursively. */
3045 static boolean
3046 elf_adjust_dynamic_symbol (h, data)
3047 struct elf_link_hash_entry *h;
3048 PTR data;
3050 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3051 bfd *dynobj;
3052 struct elf_backend_data *bed;
3054 /* Ignore indirect symbols. These are added by the versioning code. */
3055 if (h->root.type == bfd_link_hash_indirect)
3056 return true;
3058 /* Fix the symbol flags. */
3059 if (! elf_fix_symbol_flags (h, eif))
3060 return false;
3062 /* If this symbol does not require a PLT entry, and it is not
3063 defined by a dynamic object, or is not referenced by a regular
3064 object, ignore it. We do have to handle a weak defined symbol,
3065 even if no regular object refers to it, if we decided to add it
3066 to the dynamic symbol table. FIXME: Do we normally need to worry
3067 about symbols which are defined by one dynamic object and
3068 referenced by another one? */
3069 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3070 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3071 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3072 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3073 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3075 h->plt.offset = (bfd_vma) -1;
3076 return true;
3079 /* If we've already adjusted this symbol, don't do it again. This
3080 can happen via a recursive call. */
3081 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3082 return true;
3084 /* Don't look at this symbol again. Note that we must set this
3085 after checking the above conditions, because we may look at a
3086 symbol once, decide not to do anything, and then get called
3087 recursively later after REF_REGULAR is set below. */
3088 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3090 /* If this is a weak definition, and we know a real definition, and
3091 the real symbol is not itself defined by a regular object file,
3092 then get a good value for the real definition. We handle the
3093 real symbol first, for the convenience of the backend routine.
3095 Note that there is a confusing case here. If the real definition
3096 is defined by a regular object file, we don't get the real symbol
3097 from the dynamic object, but we do get the weak symbol. If the
3098 processor backend uses a COPY reloc, then if some routine in the
3099 dynamic object changes the real symbol, we will not see that
3100 change in the corresponding weak symbol. This is the way other
3101 ELF linkers work as well, and seems to be a result of the shared
3102 library model.
3104 I will clarify this issue. Most SVR4 shared libraries define the
3105 variable _timezone and define timezone as a weak synonym. The
3106 tzset call changes _timezone. If you write
3107 extern int timezone;
3108 int _timezone = 5;
3109 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3110 you might expect that, since timezone is a synonym for _timezone,
3111 the same number will print both times. However, if the processor
3112 backend uses a COPY reloc, then actually timezone will be copied
3113 into your process image, and, since you define _timezone
3114 yourself, _timezone will not. Thus timezone and _timezone will
3115 wind up at different memory locations. The tzset call will set
3116 _timezone, leaving timezone unchanged. */
3118 if (h->weakdef != NULL)
3120 struct elf_link_hash_entry *weakdef;
3122 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3123 || h->root.type == bfd_link_hash_defweak);
3124 weakdef = h->weakdef;
3125 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3126 || weakdef->root.type == bfd_link_hash_defweak);
3127 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3128 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3130 /* This symbol is defined by a regular object file, so we
3131 will not do anything special. Clear weakdef for the
3132 convenience of the processor backend. */
3133 h->weakdef = NULL;
3135 else
3137 /* There is an implicit reference by a regular object file
3138 via the weak symbol. */
3139 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3140 if (h->weakdef->elf_link_hash_flags
3141 & ELF_LINK_HASH_REF_REGULAR_NONWEAK)
3142 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
3143 if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif))
3144 return false;
3148 /* If a symbol has no type and no size and does not require a PLT
3149 entry, then we are probably about to do the wrong thing here: we
3150 are probably going to create a COPY reloc for an empty object.
3151 This case can arise when a shared object is built with assembly
3152 code, and the assembly code fails to set the symbol type. */
3153 if (h->size == 0
3154 && h->type == STT_NOTYPE
3155 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3156 (*_bfd_error_handler)
3157 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3158 h->root.root.string);
3160 dynobj = elf_hash_table (eif->info)->dynobj;
3161 bed = get_elf_backend_data (dynobj);
3162 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3164 eif->failed = true;
3165 return false;
3168 return true;
3171 /* This routine is used to export all defined symbols into the dynamic
3172 symbol table. It is called via elf_link_hash_traverse. */
3174 static boolean
3175 elf_export_symbol (h, data)
3176 struct elf_link_hash_entry *h;
3177 PTR data;
3179 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3181 /* Ignore indirect symbols. These are added by the versioning code. */
3182 if (h->root.type == bfd_link_hash_indirect)
3183 return true;
3185 if (h->dynindx == -1
3186 && (h->elf_link_hash_flags
3187 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3189 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3191 eif->failed = true;
3192 return false;
3196 return true;
3199 /* Look through the symbols which are defined in other shared
3200 libraries and referenced here. Update the list of version
3201 dependencies. This will be put into the .gnu.version_r section.
3202 This function is called via elf_link_hash_traverse. */
3204 static boolean
3205 elf_link_find_version_dependencies (h, data)
3206 struct elf_link_hash_entry *h;
3207 PTR data;
3209 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3210 Elf_Internal_Verneed *t;
3211 Elf_Internal_Vernaux *a;
3213 /* We only care about symbols defined in shared objects with version
3214 information. */
3215 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3216 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3217 || h->dynindx == -1
3218 || h->verinfo.verdef == NULL)
3219 return true;
3221 /* See if we already know about this version. */
3222 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3224 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3225 continue;
3227 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3228 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3229 return true;
3231 break;
3234 /* This is a new version. Add it to tree we are building. */
3236 if (t == NULL)
3238 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3239 if (t == NULL)
3241 rinfo->failed = true;
3242 return false;
3245 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3246 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3247 elf_tdata (rinfo->output_bfd)->verref = t;
3250 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3252 /* Note that we are copying a string pointer here, and testing it
3253 above. If bfd_elf_string_from_elf_section is ever changed to
3254 discard the string data when low in memory, this will have to be
3255 fixed. */
3256 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3258 a->vna_flags = h->verinfo.verdef->vd_flags;
3259 a->vna_nextptr = t->vn_auxptr;
3261 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3262 ++rinfo->vers;
3264 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3266 t->vn_auxptr = a;
3268 return true;
3271 /* Figure out appropriate versions for all the symbols. We may not
3272 have the version number script until we have read all of the input
3273 files, so until that point we don't know which symbols should be
3274 local. This function is called via elf_link_hash_traverse. */
3276 static boolean
3277 elf_link_assign_sym_version (h, data)
3278 struct elf_link_hash_entry *h;
3279 PTR data;
3281 struct elf_assign_sym_version_info *sinfo =
3282 (struct elf_assign_sym_version_info *) data;
3283 struct bfd_link_info *info = sinfo->info;
3284 struct elf_info_failed eif;
3285 char *p;
3287 /* Fix the symbol flags. */
3288 eif.failed = false;
3289 eif.info = info;
3290 if (! elf_fix_symbol_flags (h, &eif))
3292 if (eif.failed)
3293 sinfo->failed = true;
3294 return false;
3297 /* We only need version numbers for symbols defined in regular
3298 objects. */
3299 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3300 return true;
3302 p = strchr (h->root.root.string, ELF_VER_CHR);
3303 if (p != NULL && h->verinfo.vertree == NULL)
3305 struct bfd_elf_version_tree *t;
3306 boolean hidden;
3308 hidden = true;
3310 /* There are two consecutive ELF_VER_CHR characters if this is
3311 not a hidden symbol. */
3312 ++p;
3313 if (*p == ELF_VER_CHR)
3315 hidden = false;
3316 ++p;
3319 /* If there is no version string, we can just return out. */
3320 if (*p == '\0')
3322 if (hidden)
3323 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3324 return true;
3327 /* Look for the version. If we find it, it is no longer weak. */
3328 for (t = sinfo->verdefs; t != NULL; t = t->next)
3330 if (strcmp (t->name, p) == 0)
3332 int len;
3333 char *alc;
3334 struct bfd_elf_version_expr *d;
3336 len = p - h->root.root.string;
3337 alc = bfd_alloc (sinfo->output_bfd, len);
3338 if (alc == NULL)
3339 return false;
3340 strncpy (alc, h->root.root.string, len - 1);
3341 alc[len - 1] = '\0';
3342 if (alc[len - 2] == ELF_VER_CHR)
3343 alc[len - 2] = '\0';
3345 h->verinfo.vertree = t;
3346 t->used = true;
3347 d = NULL;
3349 if (t->globals != NULL)
3351 for (d = t->globals; d != NULL; d = d->next)
3352 if ((*d->match) (d, alc))
3353 break;
3356 /* See if there is anything to force this symbol to
3357 local scope. */
3358 if (d == NULL && t->locals != NULL)
3360 for (d = t->locals; d != NULL; d = d->next)
3362 if ((*d->match) (d, alc))
3364 if (h->dynindx != -1
3365 && info->shared
3366 && ! sinfo->export_dynamic)
3368 sinfo->removed_dynamic = true;
3369 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3370 h->elf_link_hash_flags &=~
3371 ELF_LINK_HASH_NEEDS_PLT;
3372 h->dynindx = -1;
3373 h->plt.offset = (bfd_vma) -1;
3374 /* FIXME: The name of the symbol has
3375 already been recorded in the dynamic
3376 string table section. */
3379 break;
3384 bfd_release (sinfo->output_bfd, alc);
3385 break;
3389 /* If we are building an application, we need to create a
3390 version node for this version. */
3391 if (t == NULL && ! info->shared)
3393 struct bfd_elf_version_tree **pp;
3394 int version_index;
3396 /* If we aren't going to export this symbol, we don't need
3397 to worry about it. */
3398 if (h->dynindx == -1)
3399 return true;
3401 t = ((struct bfd_elf_version_tree *)
3402 bfd_alloc (sinfo->output_bfd, sizeof *t));
3403 if (t == NULL)
3405 sinfo->failed = true;
3406 return false;
3409 t->next = NULL;
3410 t->name = p;
3411 t->globals = NULL;
3412 t->locals = NULL;
3413 t->deps = NULL;
3414 t->name_indx = (unsigned int) -1;
3415 t->used = true;
3417 version_index = 1;
3418 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3419 ++version_index;
3420 t->vernum = version_index;
3422 *pp = t;
3424 h->verinfo.vertree = t;
3426 else if (t == NULL)
3428 /* We could not find the version for a symbol when
3429 generating a shared archive. Return an error. */
3430 (*_bfd_error_handler)
3431 (_("%s: undefined versioned symbol name %s"),
3432 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3433 bfd_set_error (bfd_error_bad_value);
3434 sinfo->failed = true;
3435 return false;
3438 if (hidden)
3439 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3442 /* If we don't have a version for this symbol, see if we can find
3443 something. */
3444 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3446 struct bfd_elf_version_tree *t;
3447 struct bfd_elf_version_tree *deflt;
3448 struct bfd_elf_version_expr *d;
3450 /* See if can find what version this symbol is in. If the
3451 symbol is supposed to be local, then don't actually register
3452 it. */
3453 deflt = NULL;
3454 for (t = sinfo->verdefs; t != NULL; t = t->next)
3456 if (t->globals != NULL)
3458 for (d = t->globals; d != NULL; d = d->next)
3460 if ((*d->match) (d, h->root.root.string))
3462 h->verinfo.vertree = t;
3463 break;
3467 if (d != NULL)
3468 break;
3471 if (t->locals != NULL)
3473 for (d = t->locals; d != NULL; d = d->next)
3475 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3476 deflt = t;
3477 else if ((*d->match) (d, h->root.root.string))
3479 h->verinfo.vertree = t;
3480 if (h->dynindx != -1
3481 && info->shared
3482 && ! sinfo->export_dynamic)
3484 sinfo->removed_dynamic = true;
3485 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3486 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3487 h->dynindx = -1;
3488 h->plt.offset = (bfd_vma) -1;
3489 /* FIXME: The name of the symbol has already
3490 been recorded in the dynamic string table
3491 section. */
3493 break;
3497 if (d != NULL)
3498 break;
3502 if (deflt != NULL && h->verinfo.vertree == NULL)
3504 h->verinfo.vertree = deflt;
3505 if (h->dynindx != -1
3506 && info->shared
3507 && ! sinfo->export_dynamic)
3509 sinfo->removed_dynamic = true;
3510 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3511 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3512 h->dynindx = -1;
3513 h->plt.offset = (bfd_vma) -1;
3514 /* FIXME: The name of the symbol has already been
3515 recorded in the dynamic string table section. */
3520 return true;
3523 /* This function is used to renumber the dynamic symbols, if some of
3524 them are removed because they are marked as local. This is called
3525 via elf_link_hash_traverse. */
3527 static boolean
3528 elf_link_renumber_dynsyms (h, data)
3529 struct elf_link_hash_entry *h;
3530 PTR data;
3532 struct bfd_link_info *info = (struct bfd_link_info *) data;
3534 if (h->dynindx != -1)
3536 h->dynindx = elf_hash_table (info)->dynsymcount;
3537 ++elf_hash_table (info)->dynsymcount;
3540 return true;
3543 /* Final phase of ELF linker. */
3545 /* A structure we use to avoid passing large numbers of arguments. */
3547 struct elf_final_link_info
3549 /* General link information. */
3550 struct bfd_link_info *info;
3551 /* Output BFD. */
3552 bfd *output_bfd;
3553 /* Symbol string table. */
3554 struct bfd_strtab_hash *symstrtab;
3555 /* .dynsym section. */
3556 asection *dynsym_sec;
3557 /* .hash section. */
3558 asection *hash_sec;
3559 /* symbol version section (.gnu.version). */
3560 asection *symver_sec;
3561 /* Buffer large enough to hold contents of any section. */
3562 bfd_byte *contents;
3563 /* Buffer large enough to hold external relocs of any section. */
3564 PTR external_relocs;
3565 /* Buffer large enough to hold internal relocs of any section. */
3566 Elf_Internal_Rela *internal_relocs;
3567 /* Buffer large enough to hold external local symbols of any input
3568 BFD. */
3569 Elf_External_Sym *external_syms;
3570 /* Buffer large enough to hold internal local symbols of any input
3571 BFD. */
3572 Elf_Internal_Sym *internal_syms;
3573 /* Array large enough to hold a symbol index for each local symbol
3574 of any input BFD. */
3575 long *indices;
3576 /* Array large enough to hold a section pointer for each local
3577 symbol of any input BFD. */
3578 asection **sections;
3579 /* Buffer to hold swapped out symbols. */
3580 Elf_External_Sym *symbuf;
3581 /* Number of swapped out symbols in buffer. */
3582 size_t symbuf_count;
3583 /* Number of symbols which fit in symbuf. */
3584 size_t symbuf_size;
3587 static boolean elf_link_output_sym
3588 PARAMS ((struct elf_final_link_info *, const char *,
3589 Elf_Internal_Sym *, asection *));
3590 static boolean elf_link_flush_output_syms
3591 PARAMS ((struct elf_final_link_info *));
3592 static boolean elf_link_output_extsym
3593 PARAMS ((struct elf_link_hash_entry *, PTR));
3594 static boolean elf_link_input_bfd
3595 PARAMS ((struct elf_final_link_info *, bfd *));
3596 static boolean elf_reloc_link_order
3597 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3598 struct bfd_link_order *));
3600 /* This struct is used to pass information to elf_link_output_extsym. */
3602 struct elf_outext_info
3604 boolean failed;
3605 boolean localsyms;
3606 struct elf_final_link_info *finfo;
3609 /* Do the final step of an ELF link. */
3611 boolean
3612 elf_bfd_final_link (abfd, info)
3613 bfd *abfd;
3614 struct bfd_link_info *info;
3616 boolean dynamic;
3617 bfd *dynobj;
3618 struct elf_final_link_info finfo;
3619 register asection *o;
3620 register struct bfd_link_order *p;
3621 register bfd *sub;
3622 size_t max_contents_size;
3623 size_t max_external_reloc_size;
3624 size_t max_internal_reloc_count;
3625 size_t max_sym_count;
3626 file_ptr off;
3627 Elf_Internal_Sym elfsym;
3628 unsigned int i;
3629 Elf_Internal_Shdr *symtab_hdr;
3630 Elf_Internal_Shdr *symstrtab_hdr;
3631 struct elf_backend_data *bed = get_elf_backend_data (abfd);
3632 struct elf_outext_info eoinfo;
3634 if (info->shared)
3635 abfd->flags |= DYNAMIC;
3637 dynamic = elf_hash_table (info)->dynamic_sections_created;
3638 dynobj = elf_hash_table (info)->dynobj;
3640 finfo.info = info;
3641 finfo.output_bfd = abfd;
3642 finfo.symstrtab = elf_stringtab_init ();
3643 if (finfo.symstrtab == NULL)
3644 return false;
3646 if (! dynamic)
3648 finfo.dynsym_sec = NULL;
3649 finfo.hash_sec = NULL;
3650 finfo.symver_sec = NULL;
3652 else
3654 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
3655 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
3656 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
3657 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
3658 /* Note that it is OK if symver_sec is NULL. */
3661 finfo.contents = NULL;
3662 finfo.external_relocs = NULL;
3663 finfo.internal_relocs = NULL;
3664 finfo.external_syms = NULL;
3665 finfo.internal_syms = NULL;
3666 finfo.indices = NULL;
3667 finfo.sections = NULL;
3668 finfo.symbuf = NULL;
3669 finfo.symbuf_count = 0;
3671 /* Count up the number of relocations we will output for each output
3672 section, so that we know the sizes of the reloc sections. We
3673 also figure out some maximum sizes. */
3674 max_contents_size = 0;
3675 max_external_reloc_size = 0;
3676 max_internal_reloc_count = 0;
3677 max_sym_count = 0;
3678 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
3680 o->reloc_count = 0;
3682 for (p = o->link_order_head; p != NULL; p = p->next)
3684 if (p->type == bfd_section_reloc_link_order
3685 || p->type == bfd_symbol_reloc_link_order)
3686 ++o->reloc_count;
3687 else if (p->type == bfd_indirect_link_order)
3689 asection *sec;
3691 sec = p->u.indirect.section;
3693 /* Mark all sections which are to be included in the
3694 link. This will normally be every section. We need
3695 to do this so that we can identify any sections which
3696 the linker has decided to not include. */
3697 sec->linker_mark = true;
3699 if (info->relocateable)
3700 o->reloc_count += sec->reloc_count;
3702 if (sec->_raw_size > max_contents_size)
3703 max_contents_size = sec->_raw_size;
3704 if (sec->_cooked_size > max_contents_size)
3705 max_contents_size = sec->_cooked_size;
3707 /* We are interested in just local symbols, not all
3708 symbols. */
3709 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
3710 && (sec->owner->flags & DYNAMIC) == 0)
3712 size_t sym_count;
3714 if (elf_bad_symtab (sec->owner))
3715 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
3716 / sizeof (Elf_External_Sym));
3717 else
3718 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
3720 if (sym_count > max_sym_count)
3721 max_sym_count = sym_count;
3723 if ((sec->flags & SEC_RELOC) != 0)
3725 size_t ext_size;
3727 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
3728 if (ext_size > max_external_reloc_size)
3729 max_external_reloc_size = ext_size;
3730 if (sec->reloc_count > max_internal_reloc_count)
3731 max_internal_reloc_count = sec->reloc_count;
3737 if (o->reloc_count > 0)
3738 o->flags |= SEC_RELOC;
3739 else
3741 /* Explicitly clear the SEC_RELOC flag. The linker tends to
3742 set it (this is probably a bug) and if it is set
3743 assign_section_numbers will create a reloc section. */
3744 o->flags &=~ SEC_RELOC;
3747 /* If the SEC_ALLOC flag is not set, force the section VMA to
3748 zero. This is done in elf_fake_sections as well, but forcing
3749 the VMA to 0 here will ensure that relocs against these
3750 sections are handled correctly. */
3751 if ((o->flags & SEC_ALLOC) == 0
3752 && ! o->user_set_vma)
3753 o->vma = 0;
3756 /* Figure out the file positions for everything but the symbol table
3757 and the relocs. We set symcount to force assign_section_numbers
3758 to create a symbol table. */
3759 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
3760 BFD_ASSERT (! abfd->output_has_begun);
3761 if (! _bfd_elf_compute_section_file_positions (abfd, info))
3762 goto error_return;
3764 /* That created the reloc sections. Set their sizes, and assign
3765 them file positions, and allocate some buffers. */
3766 for (o = abfd->sections; o != NULL; o = o->next)
3768 if ((o->flags & SEC_RELOC) != 0)
3770 Elf_Internal_Shdr *rel_hdr;
3771 register struct elf_link_hash_entry **p, **pend;
3773 rel_hdr = &elf_section_data (o)->rel_hdr;
3775 rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
3777 /* The contents field must last into write_object_contents,
3778 so we allocate it with bfd_alloc rather than malloc. */
3779 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
3780 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
3781 goto error_return;
3783 p = ((struct elf_link_hash_entry **)
3784 bfd_malloc (o->reloc_count
3785 * sizeof (struct elf_link_hash_entry *)));
3786 if (p == NULL && o->reloc_count != 0)
3787 goto error_return;
3788 elf_section_data (o)->rel_hashes = p;
3789 pend = p + o->reloc_count;
3790 for (; p < pend; p++)
3791 *p = NULL;
3793 /* Use the reloc_count field as an index when outputting the
3794 relocs. */
3795 o->reloc_count = 0;
3799 _bfd_elf_assign_file_positions_for_relocs (abfd);
3801 /* We have now assigned file positions for all the sections except
3802 .symtab and .strtab. We start the .symtab section at the current
3803 file position, and write directly to it. We build the .strtab
3804 section in memory. */
3805 bfd_get_symcount (abfd) = 0;
3806 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
3807 /* sh_name is set in prep_headers. */
3808 symtab_hdr->sh_type = SHT_SYMTAB;
3809 symtab_hdr->sh_flags = 0;
3810 symtab_hdr->sh_addr = 0;
3811 symtab_hdr->sh_size = 0;
3812 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
3813 /* sh_link is set in assign_section_numbers. */
3814 /* sh_info is set below. */
3815 /* sh_offset is set just below. */
3816 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
3818 off = elf_tdata (abfd)->next_file_pos;
3819 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
3821 /* Note that at this point elf_tdata (abfd)->next_file_pos is
3822 incorrect. We do not yet know the size of the .symtab section.
3823 We correct next_file_pos below, after we do know the size. */
3825 /* Allocate a buffer to hold swapped out symbols. This is to avoid
3826 continuously seeking to the right position in the file. */
3827 if (! info->keep_memory || max_sym_count < 20)
3828 finfo.symbuf_size = 20;
3829 else
3830 finfo.symbuf_size = max_sym_count;
3831 finfo.symbuf = ((Elf_External_Sym *)
3832 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
3833 if (finfo.symbuf == NULL)
3834 goto error_return;
3836 /* Start writing out the symbol table. The first symbol is always a
3837 dummy symbol. */
3838 if (info->strip != strip_all || info->relocateable)
3840 elfsym.st_value = 0;
3841 elfsym.st_size = 0;
3842 elfsym.st_info = 0;
3843 elfsym.st_other = 0;
3844 elfsym.st_shndx = SHN_UNDEF;
3845 if (! elf_link_output_sym (&finfo, (const char *) NULL,
3846 &elfsym, bfd_und_section_ptr))
3847 goto error_return;
3850 #if 0
3851 /* Some standard ELF linkers do this, but we don't because it causes
3852 bootstrap comparison failures. */
3853 /* Output a file symbol for the output file as the second symbol.
3854 We output this even if we are discarding local symbols, although
3855 I'm not sure if this is correct. */
3856 elfsym.st_value = 0;
3857 elfsym.st_size = 0;
3858 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
3859 elfsym.st_other = 0;
3860 elfsym.st_shndx = SHN_ABS;
3861 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
3862 &elfsym, bfd_abs_section_ptr))
3863 goto error_return;
3864 #endif
3866 /* Output a symbol for each section. We output these even if we are
3867 discarding local symbols, since they are used for relocs. These
3868 symbols have no names. We store the index of each one in the
3869 index field of the section, so that we can find it again when
3870 outputting relocs. */
3871 if (info->strip != strip_all || info->relocateable)
3873 elfsym.st_size = 0;
3874 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
3875 elfsym.st_other = 0;
3876 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
3878 o = section_from_elf_index (abfd, i);
3879 if (o != NULL)
3880 o->target_index = bfd_get_symcount (abfd);
3881 elfsym.st_shndx = i;
3882 if (info->relocateable || o == NULL)
3883 elfsym.st_value = 0;
3884 else
3885 elfsym.st_value = o->vma;
3886 if (! elf_link_output_sym (&finfo, (const char *) NULL,
3887 &elfsym, o))
3888 goto error_return;
3892 /* Allocate some memory to hold information read in from the input
3893 files. */
3894 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
3895 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
3896 finfo.internal_relocs = ((Elf_Internal_Rela *)
3897 bfd_malloc (max_internal_reloc_count
3898 * sizeof (Elf_Internal_Rela)));
3899 finfo.external_syms = ((Elf_External_Sym *)
3900 bfd_malloc (max_sym_count
3901 * sizeof (Elf_External_Sym)));
3902 finfo.internal_syms = ((Elf_Internal_Sym *)
3903 bfd_malloc (max_sym_count
3904 * sizeof (Elf_Internal_Sym)));
3905 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
3906 finfo.sections = ((asection **)
3907 bfd_malloc (max_sym_count * sizeof (asection *)));
3908 if ((finfo.contents == NULL && max_contents_size != 0)
3909 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
3910 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
3911 || (finfo.external_syms == NULL && max_sym_count != 0)
3912 || (finfo.internal_syms == NULL && max_sym_count != 0)
3913 || (finfo.indices == NULL && max_sym_count != 0)
3914 || (finfo.sections == NULL && max_sym_count != 0))
3915 goto error_return;
3917 /* Since ELF permits relocations to be against local symbols, we
3918 must have the local symbols available when we do the relocations.
3919 Since we would rather only read the local symbols once, and we
3920 would rather not keep them in memory, we handle all the
3921 relocations for a single input file at the same time.
3923 Unfortunately, there is no way to know the total number of local
3924 symbols until we have seen all of them, and the local symbol
3925 indices precede the global symbol indices. This means that when
3926 we are generating relocateable output, and we see a reloc against
3927 a global symbol, we can not know the symbol index until we have
3928 finished examining all the local symbols to see which ones we are
3929 going to output. To deal with this, we keep the relocations in
3930 memory, and don't output them until the end of the link. This is
3931 an unfortunate waste of memory, but I don't see a good way around
3932 it. Fortunately, it only happens when performing a relocateable
3933 link, which is not the common case. FIXME: If keep_memory is set
3934 we could write the relocs out and then read them again; I don't
3935 know how bad the memory loss will be. */
3937 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
3938 sub->output_has_begun = false;
3939 for (o = abfd->sections; o != NULL; o = o->next)
3941 for (p = o->link_order_head; p != NULL; p = p->next)
3943 if (p->type == bfd_indirect_link_order
3944 && (bfd_get_flavour (p->u.indirect.section->owner)
3945 == bfd_target_elf_flavour))
3947 sub = p->u.indirect.section->owner;
3948 if (! sub->output_has_begun)
3950 if (! elf_link_input_bfd (&finfo, sub))
3951 goto error_return;
3952 sub->output_has_begun = true;
3955 else if (p->type == bfd_section_reloc_link_order
3956 || p->type == bfd_symbol_reloc_link_order)
3958 if (! elf_reloc_link_order (abfd, info, o, p))
3959 goto error_return;
3961 else
3963 if (! _bfd_default_link_order (abfd, info, o, p))
3964 goto error_return;
3969 /* That wrote out all the local symbols. Finish up the symbol table
3970 with the global symbols. */
3972 if (info->strip != strip_all && info->shared)
3974 /* Output any global symbols that got converted to local in a
3975 version script. We do this in a separate step since ELF
3976 requires all local symbols to appear prior to any global
3977 symbols. FIXME: We should only do this if some global
3978 symbols were, in fact, converted to become local. FIXME:
3979 Will this work correctly with the Irix 5 linker? */
3980 eoinfo.failed = false;
3981 eoinfo.finfo = &finfo;
3982 eoinfo.localsyms = true;
3983 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
3984 (PTR) &eoinfo);
3985 if (eoinfo.failed)
3986 return false;
3989 /* The sh_info field records the index of the first non local
3990 symbol. */
3991 symtab_hdr->sh_info = bfd_get_symcount (abfd);
3992 if (dynamic)
3993 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1;
3995 /* We get the global symbols from the hash table. */
3996 eoinfo.failed = false;
3997 eoinfo.localsyms = false;
3998 eoinfo.finfo = &finfo;
3999 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4000 (PTR) &eoinfo);
4001 if (eoinfo.failed)
4002 return false;
4004 /* Flush all symbols to the file. */
4005 if (! elf_link_flush_output_syms (&finfo))
4006 return false;
4008 /* Now we know the size of the symtab section. */
4009 off += symtab_hdr->sh_size;
4011 /* Finish up and write out the symbol string table (.strtab)
4012 section. */
4013 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4014 /* sh_name was set in prep_headers. */
4015 symstrtab_hdr->sh_type = SHT_STRTAB;
4016 symstrtab_hdr->sh_flags = 0;
4017 symstrtab_hdr->sh_addr = 0;
4018 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4019 symstrtab_hdr->sh_entsize = 0;
4020 symstrtab_hdr->sh_link = 0;
4021 symstrtab_hdr->sh_info = 0;
4022 /* sh_offset is set just below. */
4023 symstrtab_hdr->sh_addralign = 1;
4025 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4026 elf_tdata (abfd)->next_file_pos = off;
4028 if (bfd_get_symcount (abfd) > 0)
4030 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4031 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4032 return false;
4035 /* Adjust the relocs to have the correct symbol indices. */
4036 for (o = abfd->sections; o != NULL; o = o->next)
4038 struct elf_link_hash_entry **rel_hash;
4039 Elf_Internal_Shdr *rel_hdr;
4041 if ((o->flags & SEC_RELOC) == 0)
4042 continue;
4044 rel_hash = elf_section_data (o)->rel_hashes;
4045 rel_hdr = &elf_section_data (o)->rel_hdr;
4046 for (i = 0; i < o->reloc_count; i++, rel_hash++)
4048 if (*rel_hash == NULL)
4049 continue;
4051 BFD_ASSERT ((*rel_hash)->indx >= 0);
4053 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4055 Elf_External_Rel *erel;
4056 Elf_Internal_Rel irel;
4058 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4059 elf_swap_reloc_in (abfd, erel, &irel);
4060 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4061 ELF_R_TYPE (irel.r_info));
4062 elf_swap_reloc_out (abfd, &irel, erel);
4064 else
4066 Elf_External_Rela *erela;
4067 Elf_Internal_Rela irela;
4069 BFD_ASSERT (rel_hdr->sh_entsize
4070 == sizeof (Elf_External_Rela));
4072 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4073 elf_swap_reloca_in (abfd, erela, &irela);
4074 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4075 ELF_R_TYPE (irela.r_info));
4076 elf_swap_reloca_out (abfd, &irela, erela);
4080 /* Set the reloc_count field to 0 to prevent write_relocs from
4081 trying to swap the relocs out itself. */
4082 o->reloc_count = 0;
4085 /* If we are linking against a dynamic object, or generating a
4086 shared library, finish up the dynamic linking information. */
4087 if (dynamic)
4089 Elf_External_Dyn *dyncon, *dynconend;
4091 /* Fix up .dynamic entries. */
4092 o = bfd_get_section_by_name (dynobj, ".dynamic");
4093 BFD_ASSERT (o != NULL);
4095 dyncon = (Elf_External_Dyn *) o->contents;
4096 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4097 for (; dyncon < dynconend; dyncon++)
4099 Elf_Internal_Dyn dyn;
4100 const char *name;
4101 unsigned int type;
4103 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4105 switch (dyn.d_tag)
4107 default:
4108 break;
4110 /* SVR4 linkers seem to set DT_INIT and DT_FINI based on
4111 magic _init and _fini symbols. This is pretty ugly,
4112 but we are compatible. */
4113 case DT_INIT:
4114 name = "_init";
4115 goto get_sym;
4116 case DT_FINI:
4117 name = "_fini";
4118 get_sym:
4120 struct elf_link_hash_entry *h;
4122 h = elf_link_hash_lookup (elf_hash_table (info), name,
4123 false, false, true);
4124 if (h != NULL
4125 && (h->root.type == bfd_link_hash_defined
4126 || h->root.type == bfd_link_hash_defweak))
4128 dyn.d_un.d_val = h->root.u.def.value;
4129 o = h->root.u.def.section;
4130 if (o->output_section != NULL)
4131 dyn.d_un.d_val += (o->output_section->vma
4132 + o->output_offset);
4133 else
4135 /* The symbol is imported from another shared
4136 library and does not apply to this one. */
4137 dyn.d_un.d_val = 0;
4140 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4143 break;
4145 case DT_HASH:
4146 name = ".hash";
4147 goto get_vma;
4148 case DT_STRTAB:
4149 name = ".dynstr";
4150 goto get_vma;
4151 case DT_SYMTAB:
4152 name = ".dynsym";
4153 goto get_vma;
4154 case DT_VERDEF:
4155 name = ".gnu.version_d";
4156 goto get_vma;
4157 case DT_VERNEED:
4158 name = ".gnu.version_r";
4159 goto get_vma;
4160 case DT_VERSYM:
4161 name = ".gnu.version";
4162 get_vma:
4163 o = bfd_get_section_by_name (abfd, name);
4164 BFD_ASSERT (o != NULL);
4165 dyn.d_un.d_ptr = o->vma;
4166 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4167 break;
4169 case DT_REL:
4170 case DT_RELA:
4171 case DT_RELSZ:
4172 case DT_RELASZ:
4173 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4174 type = SHT_REL;
4175 else
4176 type = SHT_RELA;
4177 dyn.d_un.d_val = 0;
4178 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4180 Elf_Internal_Shdr *hdr;
4182 hdr = elf_elfsections (abfd)[i];
4183 if (hdr->sh_type == type
4184 && (hdr->sh_flags & SHF_ALLOC) != 0)
4186 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4187 dyn.d_un.d_val += hdr->sh_size;
4188 else
4190 if (dyn.d_un.d_val == 0
4191 || hdr->sh_addr < dyn.d_un.d_val)
4192 dyn.d_un.d_val = hdr->sh_addr;
4196 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4197 break;
4202 /* If we have created any dynamic sections, then output them. */
4203 if (dynobj != NULL)
4205 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4206 goto error_return;
4208 for (o = dynobj->sections; o != NULL; o = o->next)
4210 if ((o->flags & SEC_HAS_CONTENTS) == 0
4211 || o->_raw_size == 0)
4212 continue;
4213 if ((o->flags & SEC_LINKER_CREATED) == 0)
4215 /* At this point, we are only interested in sections
4216 created by elf_link_create_dynamic_sections. */
4217 continue;
4219 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4220 != SHT_STRTAB)
4221 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4223 if (! bfd_set_section_contents (abfd, o->output_section,
4224 o->contents, o->output_offset,
4225 o->_raw_size))
4226 goto error_return;
4228 else
4230 file_ptr off;
4232 /* The contents of the .dynstr section are actually in a
4233 stringtab. */
4234 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4235 if (bfd_seek (abfd, off, SEEK_SET) != 0
4236 || ! _bfd_stringtab_emit (abfd,
4237 elf_hash_table (info)->dynstr))
4238 goto error_return;
4243 /* If we have optimized stabs strings, output them. */
4244 if (elf_hash_table (info)->stab_info != NULL)
4246 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4247 goto error_return;
4250 if (finfo.symstrtab != NULL)
4251 _bfd_stringtab_free (finfo.symstrtab);
4252 if (finfo.contents != NULL)
4253 free (finfo.contents);
4254 if (finfo.external_relocs != NULL)
4255 free (finfo.external_relocs);
4256 if (finfo.internal_relocs != NULL)
4257 free (finfo.internal_relocs);
4258 if (finfo.external_syms != NULL)
4259 free (finfo.external_syms);
4260 if (finfo.internal_syms != NULL)
4261 free (finfo.internal_syms);
4262 if (finfo.indices != NULL)
4263 free (finfo.indices);
4264 if (finfo.sections != NULL)
4265 free (finfo.sections);
4266 if (finfo.symbuf != NULL)
4267 free (finfo.symbuf);
4268 for (o = abfd->sections; o != NULL; o = o->next)
4270 if ((o->flags & SEC_RELOC) != 0
4271 && elf_section_data (o)->rel_hashes != NULL)
4272 free (elf_section_data (o)->rel_hashes);
4275 elf_tdata (abfd)->linker = true;
4277 return true;
4279 error_return:
4280 if (finfo.symstrtab != NULL)
4281 _bfd_stringtab_free (finfo.symstrtab);
4282 if (finfo.contents != NULL)
4283 free (finfo.contents);
4284 if (finfo.external_relocs != NULL)
4285 free (finfo.external_relocs);
4286 if (finfo.internal_relocs != NULL)
4287 free (finfo.internal_relocs);
4288 if (finfo.external_syms != NULL)
4289 free (finfo.external_syms);
4290 if (finfo.internal_syms != NULL)
4291 free (finfo.internal_syms);
4292 if (finfo.indices != NULL)
4293 free (finfo.indices);
4294 if (finfo.sections != NULL)
4295 free (finfo.sections);
4296 if (finfo.symbuf != NULL)
4297 free (finfo.symbuf);
4298 for (o = abfd->sections; o != NULL; o = o->next)
4300 if ((o->flags & SEC_RELOC) != 0
4301 && elf_section_data (o)->rel_hashes != NULL)
4302 free (elf_section_data (o)->rel_hashes);
4305 return false;
4308 /* Add a symbol to the output symbol table. */
4310 static boolean
4311 elf_link_output_sym (finfo, name, elfsym, input_sec)
4312 struct elf_final_link_info *finfo;
4313 const char *name;
4314 Elf_Internal_Sym *elfsym;
4315 asection *input_sec;
4317 boolean (*output_symbol_hook) PARAMS ((bfd *,
4318 struct bfd_link_info *info,
4319 const char *,
4320 Elf_Internal_Sym *,
4321 asection *));
4323 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4324 elf_backend_link_output_symbol_hook;
4325 if (output_symbol_hook != NULL)
4327 if (! ((*output_symbol_hook)
4328 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4329 return false;
4332 if (name == (const char *) NULL || *name == '\0')
4333 elfsym->st_name = 0;
4334 else if (input_sec->flags & SEC_EXCLUDE)
4335 elfsym->st_name = 0;
4336 else
4338 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4339 name, true,
4340 false);
4341 if (elfsym->st_name == (unsigned long) -1)
4342 return false;
4345 if (finfo->symbuf_count >= finfo->symbuf_size)
4347 if (! elf_link_flush_output_syms (finfo))
4348 return false;
4351 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4352 (PTR) (finfo->symbuf + finfo->symbuf_count));
4353 ++finfo->symbuf_count;
4355 ++ bfd_get_symcount (finfo->output_bfd);
4357 return true;
4360 /* Flush the output symbols to the file. */
4362 static boolean
4363 elf_link_flush_output_syms (finfo)
4364 struct elf_final_link_info *finfo;
4366 if (finfo->symbuf_count > 0)
4368 Elf_Internal_Shdr *symtab;
4370 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4372 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4373 SEEK_SET) != 0
4374 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4375 sizeof (Elf_External_Sym), finfo->output_bfd)
4376 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4377 return false;
4379 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4381 finfo->symbuf_count = 0;
4384 return true;
4387 /* Add an external symbol to the symbol table. This is called from
4388 the hash table traversal routine. When generating a shared object,
4389 we go through the symbol table twice. The first time we output
4390 anything that might have been forced to local scope in a version
4391 script. The second time we output the symbols that are still
4392 global symbols. */
4394 static boolean
4395 elf_link_output_extsym (h, data)
4396 struct elf_link_hash_entry *h;
4397 PTR data;
4399 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4400 struct elf_final_link_info *finfo = eoinfo->finfo;
4401 boolean strip;
4402 Elf_Internal_Sym sym;
4403 asection *input_sec;
4405 /* Decide whether to output this symbol in this pass. */
4406 if (eoinfo->localsyms)
4408 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4409 return true;
4411 else
4413 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4414 return true;
4417 /* If we are not creating a shared library, and this symbol is
4418 referenced by a shared library but is not defined anywhere, then
4419 warn that it is undefined. If we do not do this, the runtime
4420 linker will complain that the symbol is undefined when the
4421 program is run. We don't have to worry about symbols that are
4422 referenced by regular files, because we will already have issued
4423 warnings for them. */
4424 if (! finfo->info->relocateable
4425 && ! (finfo->info->shared
4426 && !finfo->info->symbolic
4427 && !finfo->info->no_undefined)
4428 && h->root.type == bfd_link_hash_undefined
4429 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
4430 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4432 if (! ((*finfo->info->callbacks->undefined_symbol)
4433 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
4434 (asection *) NULL, 0)))
4436 eoinfo->failed = true;
4437 return false;
4441 /* We don't want to output symbols that have never been mentioned by
4442 a regular file, or that we have been told to strip. However, if
4443 h->indx is set to -2, the symbol is used by a reloc and we must
4444 output it. */
4445 if (h->indx == -2)
4446 strip = false;
4447 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
4448 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
4449 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
4450 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4451 strip = true;
4452 else if (finfo->info->strip == strip_all
4453 || (finfo->info->strip == strip_some
4454 && bfd_hash_lookup (finfo->info->keep_hash,
4455 h->root.root.string,
4456 false, false) == NULL))
4457 strip = true;
4458 else
4459 strip = false;
4461 /* If we're stripping it, and it's not a dynamic symbol, there's
4462 nothing else to do. */
4463 if (strip && h->dynindx == -1)
4464 return true;
4466 sym.st_value = 0;
4467 sym.st_size = h->size;
4468 sym.st_other = h->other;
4469 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4470 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
4471 else if (h->root.type == bfd_link_hash_undefweak
4472 || h->root.type == bfd_link_hash_defweak)
4473 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
4474 else
4475 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
4477 switch (h->root.type)
4479 default:
4480 case bfd_link_hash_new:
4481 abort ();
4482 return false;
4484 case bfd_link_hash_undefined:
4485 input_sec = bfd_und_section_ptr;
4486 sym.st_shndx = SHN_UNDEF;
4487 break;
4489 case bfd_link_hash_undefweak:
4490 input_sec = bfd_und_section_ptr;
4491 sym.st_shndx = SHN_UNDEF;
4492 break;
4494 case bfd_link_hash_defined:
4495 case bfd_link_hash_defweak:
4497 input_sec = h->root.u.def.section;
4498 if (input_sec->output_section != NULL)
4500 sym.st_shndx =
4501 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
4502 input_sec->output_section);
4503 if (sym.st_shndx == (unsigned short) -1)
4505 (*_bfd_error_handler)
4506 (_("%s: could not find output section %s for input section %s"),
4507 bfd_get_filename (finfo->output_bfd),
4508 input_sec->output_section->name,
4509 input_sec->name);
4510 eoinfo->failed = true;
4511 return false;
4514 /* ELF symbols in relocateable files are section relative,
4515 but in nonrelocateable files they are virtual
4516 addresses. */
4517 sym.st_value = h->root.u.def.value + input_sec->output_offset;
4518 if (! finfo->info->relocateable)
4519 sym.st_value += input_sec->output_section->vma;
4521 else
4523 BFD_ASSERT (input_sec->owner == NULL
4524 || (input_sec->owner->flags & DYNAMIC) != 0);
4525 sym.st_shndx = SHN_UNDEF;
4526 input_sec = bfd_und_section_ptr;
4529 break;
4531 case bfd_link_hash_common:
4532 input_sec = h->root.u.c.p->section;
4533 sym.st_shndx = SHN_COMMON;
4534 sym.st_value = 1 << h->root.u.c.p->alignment_power;
4535 break;
4537 case bfd_link_hash_indirect:
4538 /* These symbols are created by symbol versioning. They point
4539 to the decorated version of the name. For example, if the
4540 symbol foo@@GNU_1.2 is the default, which should be used when
4541 foo is used with no version, then we add an indirect symbol
4542 foo which points to foo@@GNU_1.2. We ignore these symbols,
4543 since the indirected symbol is already in the hash table. If
4544 the indirect symbol is non-ELF, fall through and output it. */
4545 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) == 0)
4546 return true;
4548 /* Fall through. */
4549 case bfd_link_hash_warning:
4550 /* We can't represent these symbols in ELF, although a warning
4551 symbol may have come from a .gnu.warning.SYMBOL section. We
4552 just put the target symbol in the hash table. If the target
4553 symbol does not really exist, don't do anything. */
4554 if (h->root.u.i.link->type == bfd_link_hash_new)
4555 return true;
4556 return (elf_link_output_extsym
4557 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
4560 /* Give the processor backend a chance to tweak the symbol value,
4561 and also to finish up anything that needs to be done for this
4562 symbol. */
4563 if ((h->dynindx != -1
4564 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4565 && elf_hash_table (finfo->info)->dynamic_sections_created)
4567 struct elf_backend_data *bed;
4569 bed = get_elf_backend_data (finfo->output_bfd);
4570 if (! ((*bed->elf_backend_finish_dynamic_symbol)
4571 (finfo->output_bfd, finfo->info, h, &sym)))
4573 eoinfo->failed = true;
4574 return false;
4578 /* If we are marking the symbol as undefined, and there are no
4579 non-weak references to this symbol from a regular object, then
4580 mark the symbol as weak undefined. We can't do this earlier,
4581 because it might not be marked as undefined until the
4582 finish_dynamic_symbol routine gets through with it. */
4583 if (sym.st_shndx == SHN_UNDEF
4584 && sym.st_info == ELF_ST_INFO (STB_GLOBAL, h->type)
4585 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
4586 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) == 0)
4587 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
4589 /* If this symbol should be put in the .dynsym section, then put it
4590 there now. We have already know the symbol index. We also fill
4591 in the entry in the .hash section. */
4592 if (h->dynindx != -1
4593 && elf_hash_table (finfo->info)->dynamic_sections_created)
4595 size_t bucketcount;
4596 size_t bucket;
4597 bfd_byte *bucketpos;
4598 bfd_vma chain;
4600 sym.st_name = h->dynstr_index;
4602 elf_swap_symbol_out (finfo->output_bfd, &sym,
4603 (PTR) (((Elf_External_Sym *)
4604 finfo->dynsym_sec->contents)
4605 + h->dynindx));
4607 bucketcount = elf_hash_table (finfo->info)->bucketcount;
4608 bucket = h->elf_hash_value % bucketcount;
4609 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
4610 + (bucket + 2) * (ARCH_SIZE / 8));
4611 chain = get_word (finfo->output_bfd, bucketpos);
4612 put_word (finfo->output_bfd, h->dynindx, bucketpos);
4613 put_word (finfo->output_bfd, chain,
4614 ((bfd_byte *) finfo->hash_sec->contents
4615 + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
4617 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
4619 Elf_Internal_Versym iversym;
4621 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
4623 if (h->verinfo.verdef == NULL)
4624 iversym.vs_vers = 0;
4625 else
4626 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
4628 else
4630 if (h->verinfo.vertree == NULL)
4631 iversym.vs_vers = 1;
4632 else
4633 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
4636 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
4637 iversym.vs_vers |= VERSYM_HIDDEN;
4639 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
4640 (((Elf_External_Versym *)
4641 finfo->symver_sec->contents)
4642 + h->dynindx));
4646 /* If we're stripping it, then it was just a dynamic symbol, and
4647 there's nothing else to do. */
4648 if (strip)
4649 return true;
4651 h->indx = bfd_get_symcount (finfo->output_bfd);
4653 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
4655 eoinfo->failed = true;
4656 return false;
4659 return true;
4662 /* Link an input file into the linker output file. This function
4663 handles all the sections and relocations of the input file at once.
4664 This is so that we only have to read the local symbols once, and
4665 don't have to keep them in memory. */
4667 static boolean
4668 elf_link_input_bfd (finfo, input_bfd)
4669 struct elf_final_link_info *finfo;
4670 bfd *input_bfd;
4672 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
4673 bfd *, asection *, bfd_byte *,
4674 Elf_Internal_Rela *,
4675 Elf_Internal_Sym *, asection **));
4676 bfd *output_bfd;
4677 Elf_Internal_Shdr *symtab_hdr;
4678 size_t locsymcount;
4679 size_t extsymoff;
4680 Elf_External_Sym *external_syms;
4681 Elf_External_Sym *esym;
4682 Elf_External_Sym *esymend;
4683 Elf_Internal_Sym *isym;
4684 long *pindex;
4685 asection **ppsection;
4686 asection *o;
4688 output_bfd = finfo->output_bfd;
4689 relocate_section =
4690 get_elf_backend_data (output_bfd)->elf_backend_relocate_section;
4692 /* If this is a dynamic object, we don't want to do anything here:
4693 we don't want the local symbols, and we don't want the section
4694 contents. */
4695 if ((input_bfd->flags & DYNAMIC) != 0)
4696 return true;
4698 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
4699 if (elf_bad_symtab (input_bfd))
4701 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
4702 extsymoff = 0;
4704 else
4706 locsymcount = symtab_hdr->sh_info;
4707 extsymoff = symtab_hdr->sh_info;
4710 /* Read the local symbols. */
4711 if (symtab_hdr->contents != NULL)
4712 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
4713 else if (locsymcount == 0)
4714 external_syms = NULL;
4715 else
4717 external_syms = finfo->external_syms;
4718 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
4719 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
4720 locsymcount, input_bfd)
4721 != locsymcount * sizeof (Elf_External_Sym)))
4722 return false;
4725 /* Swap in the local symbols and write out the ones which we know
4726 are going into the output file. */
4727 esym = external_syms;
4728 esymend = esym + locsymcount;
4729 isym = finfo->internal_syms;
4730 pindex = finfo->indices;
4731 ppsection = finfo->sections;
4732 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
4734 asection *isec;
4735 const char *name;
4736 Elf_Internal_Sym osym;
4738 elf_swap_symbol_in (input_bfd, esym, isym);
4739 *pindex = -1;
4741 if (elf_bad_symtab (input_bfd))
4743 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
4745 *ppsection = NULL;
4746 continue;
4750 if (isym->st_shndx == SHN_UNDEF)
4751 isec = bfd_und_section_ptr;
4752 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
4753 isec = section_from_elf_index (input_bfd, isym->st_shndx);
4754 else if (isym->st_shndx == SHN_ABS)
4755 isec = bfd_abs_section_ptr;
4756 else if (isym->st_shndx == SHN_COMMON)
4757 isec = bfd_com_section_ptr;
4758 else
4760 /* Who knows? */
4761 isec = NULL;
4764 *ppsection = isec;
4766 /* Don't output the first, undefined, symbol. */
4767 if (esym == external_syms)
4768 continue;
4770 /* If we are stripping all symbols, we don't want to output this
4771 one. */
4772 if (finfo->info->strip == strip_all)
4773 continue;
4775 /* We never output section symbols. Instead, we use the section
4776 symbol of the corresponding section in the output file. */
4777 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
4778 continue;
4780 /* If we are discarding all local symbols, we don't want to
4781 output this one. If we are generating a relocateable output
4782 file, then some of the local symbols may be required by
4783 relocs; we output them below as we discover that they are
4784 needed. */
4785 if (finfo->info->discard == discard_all)
4786 continue;
4788 /* If this symbol is defined in a section which we are
4789 discarding, we don't need to keep it, but note that
4790 linker_mark is only reliable for sections that have contents.
4791 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
4792 as well as linker_mark. */
4793 if (isym->st_shndx > 0
4794 && isym->st_shndx < SHN_LORESERVE
4795 && isec != NULL
4796 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
4797 || (! finfo->info->relocateable
4798 && (isec->flags & SEC_EXCLUDE) != 0)))
4799 continue;
4801 /* Get the name of the symbol. */
4802 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
4803 isym->st_name);
4804 if (name == NULL)
4805 return false;
4807 /* See if we are discarding symbols with this name. */
4808 if ((finfo->info->strip == strip_some
4809 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
4810 == NULL))
4811 || (finfo->info->discard == discard_l
4812 && bfd_is_local_label_name (input_bfd, name)))
4813 continue;
4815 /* If we get here, we are going to output this symbol. */
4817 osym = *isym;
4819 /* Adjust the section index for the output file. */
4820 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
4821 isec->output_section);
4822 if (osym.st_shndx == (unsigned short) -1)
4823 return false;
4825 *pindex = bfd_get_symcount (output_bfd);
4827 /* ELF symbols in relocateable files are section relative, but
4828 in executable files they are virtual addresses. Note that
4829 this code assumes that all ELF sections have an associated
4830 BFD section with a reasonable value for output_offset; below
4831 we assume that they also have a reasonable value for
4832 output_section. Any special sections must be set up to meet
4833 these requirements. */
4834 osym.st_value += isec->output_offset;
4835 if (! finfo->info->relocateable)
4836 osym.st_value += isec->output_section->vma;
4838 if (! elf_link_output_sym (finfo, name, &osym, isec))
4839 return false;
4842 /* Relocate the contents of each section. */
4843 for (o = input_bfd->sections; o != NULL; o = o->next)
4845 bfd_byte *contents;
4847 if (! o->linker_mark)
4849 /* This section was omitted from the link. */
4850 continue;
4853 if ((o->flags & SEC_HAS_CONTENTS) == 0
4854 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
4855 continue;
4857 if ((o->flags & SEC_LINKER_CREATED) != 0)
4859 /* Section was created by elf_link_create_dynamic_sections
4860 or somesuch. */
4861 continue;
4864 /* Get the contents of the section. They have been cached by a
4865 relaxation routine. Note that o is a section in an input
4866 file, so the contents field will not have been set by any of
4867 the routines which work on output files. */
4868 if (elf_section_data (o)->this_hdr.contents != NULL)
4869 contents = elf_section_data (o)->this_hdr.contents;
4870 else
4872 contents = finfo->contents;
4873 if (! bfd_get_section_contents (input_bfd, o, contents,
4874 (file_ptr) 0, o->_raw_size))
4875 return false;
4878 if ((o->flags & SEC_RELOC) != 0)
4880 Elf_Internal_Rela *internal_relocs;
4882 /* Get the swapped relocs. */
4883 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
4884 (input_bfd, o, finfo->external_relocs,
4885 finfo->internal_relocs, false));
4886 if (internal_relocs == NULL
4887 && o->reloc_count > 0)
4888 return false;
4890 /* Relocate the section by invoking a back end routine.
4892 The back end routine is responsible for adjusting the
4893 section contents as necessary, and (if using Rela relocs
4894 and generating a relocateable output file) adjusting the
4895 reloc addend as necessary.
4897 The back end routine does not have to worry about setting
4898 the reloc address or the reloc symbol index.
4900 The back end routine is given a pointer to the swapped in
4901 internal symbols, and can access the hash table entries
4902 for the external symbols via elf_sym_hashes (input_bfd).
4904 When generating relocateable output, the back end routine
4905 must handle STB_LOCAL/STT_SECTION symbols specially. The
4906 output symbol is going to be a section symbol
4907 corresponding to the output section, which will require
4908 the addend to be adjusted. */
4910 if (! (*relocate_section) (output_bfd, finfo->info,
4911 input_bfd, o, contents,
4912 internal_relocs,
4913 finfo->internal_syms,
4914 finfo->sections))
4915 return false;
4917 if (finfo->info->relocateable)
4919 Elf_Internal_Rela *irela;
4920 Elf_Internal_Rela *irelaend;
4921 struct elf_link_hash_entry **rel_hash;
4922 Elf_Internal_Shdr *input_rel_hdr;
4923 Elf_Internal_Shdr *output_rel_hdr;
4925 /* Adjust the reloc addresses and symbol indices. */
4927 irela = internal_relocs;
4928 irelaend = irela + o->reloc_count;
4929 rel_hash = (elf_section_data (o->output_section)->rel_hashes
4930 + o->output_section->reloc_count);
4931 for (; irela < irelaend; irela++, rel_hash++)
4933 unsigned long r_symndx;
4934 Elf_Internal_Sym *isym;
4935 asection *sec;
4937 irela->r_offset += o->output_offset;
4939 r_symndx = ELF_R_SYM (irela->r_info);
4941 if (r_symndx == 0)
4942 continue;
4944 if (r_symndx >= locsymcount
4945 || (elf_bad_symtab (input_bfd)
4946 && finfo->sections[r_symndx] == NULL))
4948 struct elf_link_hash_entry *rh;
4949 long indx;
4951 /* This is a reloc against a global symbol. We
4952 have not yet output all the local symbols, so
4953 we do not know the symbol index of any global
4954 symbol. We set the rel_hash entry for this
4955 reloc to point to the global hash table entry
4956 for this symbol. The symbol index is then
4957 set at the end of elf_bfd_final_link. */
4958 indx = r_symndx - extsymoff;
4959 rh = elf_sym_hashes (input_bfd)[indx];
4960 while (rh->root.type == bfd_link_hash_indirect
4961 || rh->root.type == bfd_link_hash_warning)
4962 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
4964 /* Setting the index to -2 tells
4965 elf_link_output_extsym that this symbol is
4966 used by a reloc. */
4967 BFD_ASSERT (rh->indx < 0);
4968 rh->indx = -2;
4970 *rel_hash = rh;
4972 continue;
4975 /* This is a reloc against a local symbol. */
4977 *rel_hash = NULL;
4978 isym = finfo->internal_syms + r_symndx;
4979 sec = finfo->sections[r_symndx];
4980 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
4982 /* I suppose the backend ought to fill in the
4983 section of any STT_SECTION symbol against a
4984 processor specific section. If we have
4985 discarded a section, the output_section will
4986 be the absolute section. */
4987 if (sec != NULL
4988 && (bfd_is_abs_section (sec)
4989 || (sec->output_section != NULL
4990 && bfd_is_abs_section (sec->output_section))))
4991 r_symndx = 0;
4992 else if (sec == NULL || sec->owner == NULL)
4994 bfd_set_error (bfd_error_bad_value);
4995 return false;
4997 else
4999 r_symndx = sec->output_section->target_index;
5000 BFD_ASSERT (r_symndx != 0);
5003 else
5005 if (finfo->indices[r_symndx] == -1)
5007 unsigned long link;
5008 const char *name;
5009 asection *osec;
5011 if (finfo->info->strip == strip_all)
5013 /* You can't do ld -r -s. */
5014 bfd_set_error (bfd_error_invalid_operation);
5015 return false;
5018 /* This symbol was skipped earlier, but
5019 since it is needed by a reloc, we
5020 must output it now. */
5021 link = symtab_hdr->sh_link;
5022 name = bfd_elf_string_from_elf_section (input_bfd,
5023 link,
5024 isym->st_name);
5025 if (name == NULL)
5026 return false;
5028 osec = sec->output_section;
5029 isym->st_shndx =
5030 _bfd_elf_section_from_bfd_section (output_bfd,
5031 osec);
5032 if (isym->st_shndx == (unsigned short) -1)
5033 return false;
5035 isym->st_value += sec->output_offset;
5036 if (! finfo->info->relocateable)
5037 isym->st_value += osec->vma;
5039 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5041 if (! elf_link_output_sym (finfo, name, isym, sec))
5042 return false;
5045 r_symndx = finfo->indices[r_symndx];
5048 irela->r_info = ELF_R_INFO (r_symndx,
5049 ELF_R_TYPE (irela->r_info));
5052 /* Swap out the relocs. */
5053 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5054 output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
5055 BFD_ASSERT (output_rel_hdr->sh_entsize
5056 == input_rel_hdr->sh_entsize);
5057 irela = internal_relocs;
5058 irelaend = irela + o->reloc_count;
5059 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5061 Elf_External_Rel *erel;
5063 erel = ((Elf_External_Rel *) output_rel_hdr->contents
5064 + o->output_section->reloc_count);
5065 for (; irela < irelaend; irela++, erel++)
5067 Elf_Internal_Rel irel;
5069 irel.r_offset = irela->r_offset;
5070 irel.r_info = irela->r_info;
5071 BFD_ASSERT (irela->r_addend == 0);
5072 elf_swap_reloc_out (output_bfd, &irel, erel);
5075 else
5077 Elf_External_Rela *erela;
5079 BFD_ASSERT (input_rel_hdr->sh_entsize
5080 == sizeof (Elf_External_Rela));
5081 erela = ((Elf_External_Rela *) output_rel_hdr->contents
5082 + o->output_section->reloc_count);
5083 for (; irela < irelaend; irela++, erela++)
5084 elf_swap_reloca_out (output_bfd, irela, erela);
5087 o->output_section->reloc_count += o->reloc_count;
5091 /* Write out the modified section contents. */
5092 if (elf_section_data (o)->stab_info == NULL)
5094 if (! (o->flags & SEC_EXCLUDE) &&
5095 ! bfd_set_section_contents (output_bfd, o->output_section,
5096 contents, o->output_offset,
5097 (o->_cooked_size != 0
5098 ? o->_cooked_size
5099 : o->_raw_size)))
5100 return false;
5102 else
5104 if (! (_bfd_write_section_stabs
5105 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5106 o, &elf_section_data (o)->stab_info, contents)))
5107 return false;
5111 return true;
5114 /* Generate a reloc when linking an ELF file. This is a reloc
5115 requested by the linker, and does come from any input file. This
5116 is used to build constructor and destructor tables when linking
5117 with -Ur. */
5119 static boolean
5120 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5121 bfd *output_bfd;
5122 struct bfd_link_info *info;
5123 asection *output_section;
5124 struct bfd_link_order *link_order;
5126 reloc_howto_type *howto;
5127 long indx;
5128 bfd_vma offset;
5129 bfd_vma addend;
5130 struct elf_link_hash_entry **rel_hash_ptr;
5131 Elf_Internal_Shdr *rel_hdr;
5133 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5134 if (howto == NULL)
5136 bfd_set_error (bfd_error_bad_value);
5137 return false;
5140 addend = link_order->u.reloc.p->addend;
5142 /* Figure out the symbol index. */
5143 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5144 + output_section->reloc_count);
5145 if (link_order->type == bfd_section_reloc_link_order)
5147 indx = link_order->u.reloc.p->u.section->target_index;
5148 BFD_ASSERT (indx != 0);
5149 *rel_hash_ptr = NULL;
5151 else
5153 struct elf_link_hash_entry *h;
5155 /* Treat a reloc against a defined symbol as though it were
5156 actually against the section. */
5157 h = ((struct elf_link_hash_entry *)
5158 bfd_wrapped_link_hash_lookup (output_bfd, info,
5159 link_order->u.reloc.p->u.name,
5160 false, false, true));
5161 if (h != NULL
5162 && (h->root.type == bfd_link_hash_defined
5163 || h->root.type == bfd_link_hash_defweak))
5165 asection *section;
5167 section = h->root.u.def.section;
5168 indx = section->output_section->target_index;
5169 *rel_hash_ptr = NULL;
5170 /* It seems that we ought to add the symbol value to the
5171 addend here, but in practice it has already been added
5172 because it was passed to constructor_callback. */
5173 addend += section->output_section->vma + section->output_offset;
5175 else if (h != NULL)
5177 /* Setting the index to -2 tells elf_link_output_extsym that
5178 this symbol is used by a reloc. */
5179 h->indx = -2;
5180 *rel_hash_ptr = h;
5181 indx = 0;
5183 else
5185 if (! ((*info->callbacks->unattached_reloc)
5186 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5187 (asection *) NULL, (bfd_vma) 0)))
5188 return false;
5189 indx = 0;
5193 /* If this is an inplace reloc, we must write the addend into the
5194 object file. */
5195 if (howto->partial_inplace && addend != 0)
5197 bfd_size_type size;
5198 bfd_reloc_status_type rstat;
5199 bfd_byte *buf;
5200 boolean ok;
5202 size = bfd_get_reloc_size (howto);
5203 buf = (bfd_byte *) bfd_zmalloc (size);
5204 if (buf == (bfd_byte *) NULL)
5205 return false;
5206 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5207 switch (rstat)
5209 case bfd_reloc_ok:
5210 break;
5211 default:
5212 case bfd_reloc_outofrange:
5213 abort ();
5214 case bfd_reloc_overflow:
5215 if (! ((*info->callbacks->reloc_overflow)
5216 (info,
5217 (link_order->type == bfd_section_reloc_link_order
5218 ? bfd_section_name (output_bfd,
5219 link_order->u.reloc.p->u.section)
5220 : link_order->u.reloc.p->u.name),
5221 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5222 (bfd_vma) 0)))
5224 free (buf);
5225 return false;
5227 break;
5229 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5230 (file_ptr) link_order->offset, size);
5231 free (buf);
5232 if (! ok)
5233 return false;
5236 /* The address of a reloc is relative to the section in a
5237 relocateable file, and is a virtual address in an executable
5238 file. */
5239 offset = link_order->offset;
5240 if (! info->relocateable)
5241 offset += output_section->vma;
5243 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5245 if (rel_hdr->sh_type == SHT_REL)
5247 Elf_Internal_Rel irel;
5248 Elf_External_Rel *erel;
5250 irel.r_offset = offset;
5251 irel.r_info = ELF_R_INFO (indx, howto->type);
5252 erel = ((Elf_External_Rel *) rel_hdr->contents
5253 + output_section->reloc_count);
5254 elf_swap_reloc_out (output_bfd, &irel, erel);
5256 else
5258 Elf_Internal_Rela irela;
5259 Elf_External_Rela *erela;
5261 irela.r_offset = offset;
5262 irela.r_info = ELF_R_INFO (indx, howto->type);
5263 irela.r_addend = addend;
5264 erela = ((Elf_External_Rela *) rel_hdr->contents
5265 + output_section->reloc_count);
5266 elf_swap_reloca_out (output_bfd, &irela, erela);
5269 ++output_section->reloc_count;
5271 return true;
5275 /* Allocate a pointer to live in a linker created section. */
5277 boolean
5278 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5279 bfd *abfd;
5280 struct bfd_link_info *info;
5281 elf_linker_section_t *lsect;
5282 struct elf_link_hash_entry *h;
5283 const Elf_Internal_Rela *rel;
5285 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5286 elf_linker_section_pointers_t *linker_section_ptr;
5287 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5289 BFD_ASSERT (lsect != NULL);
5291 /* Is this a global symbol? */
5292 if (h != NULL)
5294 /* Has this symbol already been allocated, if so, our work is done */
5295 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5296 rel->r_addend,
5297 lsect->which))
5298 return true;
5300 ptr_linker_section_ptr = &h->linker_section_pointer;
5301 /* Make sure this symbol is output as a dynamic symbol. */
5302 if (h->dynindx == -1)
5304 if (! elf_link_record_dynamic_symbol (info, h))
5305 return false;
5308 if (lsect->rel_section)
5309 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5312 else /* Allocation of a pointer to a local symbol */
5314 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5316 /* Allocate a table to hold the local symbols if first time */
5317 if (!ptr)
5319 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5320 register unsigned int i;
5322 ptr = (elf_linker_section_pointers_t **)
5323 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5325 if (!ptr)
5326 return false;
5328 elf_local_ptr_offsets (abfd) = ptr;
5329 for (i = 0; i < num_symbols; i++)
5330 ptr[i] = (elf_linker_section_pointers_t *)0;
5333 /* Has this symbol already been allocated, if so, our work is done */
5334 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5335 rel->r_addend,
5336 lsect->which))
5337 return true;
5339 ptr_linker_section_ptr = &ptr[r_symndx];
5341 if (info->shared)
5343 /* If we are generating a shared object, we need to
5344 output a R_<xxx>_RELATIVE reloc so that the
5345 dynamic linker can adjust this GOT entry. */
5346 BFD_ASSERT (lsect->rel_section != NULL);
5347 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5351 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
5352 from internal memory. */
5353 BFD_ASSERT (ptr_linker_section_ptr != NULL);
5354 linker_section_ptr = (elf_linker_section_pointers_t *)
5355 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
5357 if (!linker_section_ptr)
5358 return false;
5360 linker_section_ptr->next = *ptr_linker_section_ptr;
5361 linker_section_ptr->addend = rel->r_addend;
5362 linker_section_ptr->which = lsect->which;
5363 linker_section_ptr->written_address_p = false;
5364 *ptr_linker_section_ptr = linker_section_ptr;
5366 #if 0
5367 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
5369 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
5370 lsect->hole_offset += ARCH_SIZE / 8;
5371 lsect->sym_offset += ARCH_SIZE / 8;
5372 if (lsect->sym_hash) /* Bump up symbol value if needed */
5374 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
5375 #ifdef DEBUG
5376 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
5377 lsect->sym_hash->root.root.string,
5378 (long)ARCH_SIZE / 8,
5379 (long)lsect->sym_hash->root.u.def.value);
5380 #endif
5383 else
5384 #endif
5385 linker_section_ptr->offset = lsect->section->_raw_size;
5387 lsect->section->_raw_size += ARCH_SIZE / 8;
5389 #ifdef DEBUG
5390 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
5391 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
5392 #endif
5394 return true;
5398 #if ARCH_SIZE==64
5399 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
5400 #endif
5401 #if ARCH_SIZE==32
5402 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
5403 #endif
5405 /* Fill in the address for a pointer generated in alinker section. */
5407 bfd_vma
5408 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
5409 bfd *output_bfd;
5410 bfd *input_bfd;
5411 struct bfd_link_info *info;
5412 elf_linker_section_t *lsect;
5413 struct elf_link_hash_entry *h;
5414 bfd_vma relocation;
5415 const Elf_Internal_Rela *rel;
5416 int relative_reloc;
5418 elf_linker_section_pointers_t *linker_section_ptr;
5420 BFD_ASSERT (lsect != NULL);
5422 if (h != NULL) /* global symbol */
5424 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5425 rel->r_addend,
5426 lsect->which);
5428 BFD_ASSERT (linker_section_ptr != NULL);
5430 if (! elf_hash_table (info)->dynamic_sections_created
5431 || (info->shared
5432 && info->symbolic
5433 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
5435 /* This is actually a static link, or it is a
5436 -Bsymbolic link and the symbol is defined
5437 locally. We must initialize this entry in the
5438 global section.
5440 When doing a dynamic link, we create a .rela.<xxx>
5441 relocation entry to initialize the value. This
5442 is done in the finish_dynamic_symbol routine. */
5443 if (!linker_section_ptr->written_address_p)
5445 linker_section_ptr->written_address_p = true;
5446 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
5447 lsect->section->contents + linker_section_ptr->offset);
5451 else /* local symbol */
5453 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
5454 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
5455 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
5456 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
5457 rel->r_addend,
5458 lsect->which);
5460 BFD_ASSERT (linker_section_ptr != NULL);
5462 /* Write out pointer if it hasn't been rewritten out before */
5463 if (!linker_section_ptr->written_address_p)
5465 linker_section_ptr->written_address_p = true;
5466 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
5467 lsect->section->contents + linker_section_ptr->offset);
5469 if (info->shared)
5471 asection *srel = lsect->rel_section;
5472 Elf_Internal_Rela outrel;
5474 /* We need to generate a relative reloc for the dynamic linker. */
5475 if (!srel)
5476 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
5477 lsect->rel_name);
5479 BFD_ASSERT (srel != NULL);
5481 outrel.r_offset = (lsect->section->output_section->vma
5482 + lsect->section->output_offset
5483 + linker_section_ptr->offset);
5484 outrel.r_info = ELF_R_INFO (0, relative_reloc);
5485 outrel.r_addend = 0;
5486 elf_swap_reloca_out (output_bfd, &outrel,
5487 (((Elf_External_Rela *)
5488 lsect->section->contents)
5489 + lsect->section->reloc_count));
5490 ++lsect->section->reloc_count;
5495 relocation = (lsect->section->output_offset
5496 + linker_section_ptr->offset
5497 - lsect->hole_offset
5498 - lsect->sym_offset);
5500 #ifdef DEBUG
5501 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
5502 lsect->name, (long)relocation, (long)relocation);
5503 #endif
5505 /* Subtract out the addend, because it will get added back in by the normal
5506 processing. */
5507 return relocation - linker_section_ptr->addend;
5510 /* Garbage collect unused sections. */
5512 static boolean elf_gc_mark
5513 PARAMS ((struct bfd_link_info *info, asection *sec,
5514 asection * (*gc_mark_hook)
5515 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
5516 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
5518 static boolean elf_gc_sweep
5519 PARAMS ((struct bfd_link_info *info,
5520 boolean (*gc_sweep_hook)
5521 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
5522 const Elf_Internal_Rela *relocs))));
5524 static boolean elf_gc_sweep_symbol
5525 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
5527 static boolean elf_gc_allocate_got_offsets
5528 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
5530 static boolean elf_gc_propagate_vtable_entries_used
5531 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
5533 static boolean elf_gc_smash_unused_vtentry_relocs
5534 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
5536 /* The mark phase of garbage collection. For a given section, mark
5537 it, and all the sections which define symbols to which it refers. */
5539 static boolean
5540 elf_gc_mark (info, sec, gc_mark_hook)
5541 struct bfd_link_info *info;
5542 asection *sec;
5543 asection * (*gc_mark_hook)
5544 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
5545 struct elf_link_hash_entry *, Elf_Internal_Sym *));
5547 boolean ret = true;
5549 sec->gc_mark = 1;
5551 /* Look through the section relocs. */
5553 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
5555 Elf_Internal_Rela *relstart, *rel, *relend;
5556 Elf_Internal_Shdr *symtab_hdr;
5557 struct elf_link_hash_entry **sym_hashes;
5558 size_t nlocsyms;
5559 size_t extsymoff;
5560 Elf_External_Sym *locsyms, *freesyms = NULL;
5561 bfd *input_bfd = sec->owner;
5563 /* GCFIXME: how to arrange so that relocs and symbols are not
5564 reread continually? */
5566 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5567 sym_hashes = elf_sym_hashes (input_bfd);
5569 /* Read the local symbols. */
5570 if (elf_bad_symtab (input_bfd))
5572 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5573 extsymoff = 0;
5575 else
5576 extsymoff = nlocsyms = symtab_hdr->sh_info;
5577 if (symtab_hdr->contents)
5578 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
5579 else if (nlocsyms == 0)
5580 locsyms = NULL;
5581 else
5583 locsyms = freesyms =
5584 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
5585 if (freesyms == NULL
5586 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5587 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
5588 nlocsyms, input_bfd)
5589 != nlocsyms * sizeof (Elf_External_Sym)))
5591 ret = false;
5592 goto out1;
5596 /* Read the relocations. */
5597 relstart = (NAME(_bfd_elf,link_read_relocs)
5598 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
5599 info->keep_memory));
5600 if (relstart == NULL)
5602 ret = false;
5603 goto out1;
5605 relend = relstart + sec->reloc_count;
5607 for (rel = relstart; rel < relend; rel++)
5609 unsigned long r_symndx;
5610 asection *rsec;
5611 struct elf_link_hash_entry *h;
5612 Elf_Internal_Sym s;
5614 r_symndx = ELF_R_SYM (rel->r_info);
5615 if (r_symndx == 0)
5616 continue;
5618 if (elf_bad_symtab (sec->owner))
5620 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
5621 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
5622 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
5623 else
5625 h = sym_hashes[r_symndx - extsymoff];
5626 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
5629 else if (r_symndx >= nlocsyms)
5631 h = sym_hashes[r_symndx - extsymoff];
5632 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
5634 else
5636 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
5637 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
5640 if (rsec && !rsec->gc_mark)
5641 if (!elf_gc_mark (info, rsec, gc_mark_hook))
5643 ret = false;
5644 goto out2;
5648 out2:
5649 if (!info->keep_memory)
5650 free (relstart);
5651 out1:
5652 if (freesyms)
5653 free (freesyms);
5656 return ret;
5659 /* The sweep phase of garbage collection. Remove all garbage sections. */
5661 static boolean
5662 elf_gc_sweep (info, gc_sweep_hook)
5663 struct bfd_link_info *info;
5664 boolean (*gc_sweep_hook)
5665 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
5666 const Elf_Internal_Rela *relocs));
5668 bfd *sub;
5670 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
5672 asection *o;
5674 for (o = sub->sections; o != NULL; o = o->next)
5676 /* Keep special sections. Keep .debug sections. */
5677 if ((o->flags & SEC_LINKER_CREATED)
5678 || (o->flags & SEC_DEBUGGING))
5679 o->gc_mark = 1;
5681 if (o->gc_mark)
5682 continue;
5684 /* Skip sweeping sections already excluded. */
5685 if (o->flags & SEC_EXCLUDE)
5686 continue;
5688 /* Since this is early in the link process, it is simple
5689 to remove a section from the output. */
5690 o->flags |= SEC_EXCLUDE;
5692 /* But we also have to update some of the relocation
5693 info we collected before. */
5694 if (gc_sweep_hook
5695 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
5697 Elf_Internal_Rela *internal_relocs;
5698 boolean r;
5700 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5701 (o->owner, o, NULL, NULL, info->keep_memory));
5702 if (internal_relocs == NULL)
5703 return false;
5705 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
5707 if (!info->keep_memory)
5708 free (internal_relocs);
5710 if (!r)
5711 return false;
5716 /* Remove the symbols that were in the swept sections from the dynamic
5717 symbol table. GCFIXME: Anyone know how to get them out of the
5718 static symbol table as well? */
5720 int i = 0;
5722 elf_link_hash_traverse (elf_hash_table (info),
5723 elf_gc_sweep_symbol,
5724 (PTR) &i);
5726 elf_hash_table (info)->dynsymcount = i;
5729 return true;
5732 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
5734 static boolean
5735 elf_gc_sweep_symbol (h, idxptr)
5736 struct elf_link_hash_entry *h;
5737 PTR idxptr;
5739 int *idx = (int *) idxptr;
5741 if (h->dynindx != -1
5742 && ((h->root.type != bfd_link_hash_defined
5743 && h->root.type != bfd_link_hash_defweak)
5744 || h->root.u.def.section->gc_mark))
5745 h->dynindx = (*idx)++;
5747 return true;
5750 /* Propogate collected vtable information. This is called through
5751 elf_link_hash_traverse. */
5753 static boolean
5754 elf_gc_propagate_vtable_entries_used (h, okp)
5755 struct elf_link_hash_entry *h;
5756 PTR okp;
5758 /* Those that are not vtables. */
5759 if (h->vtable_parent == NULL)
5760 return true;
5762 /* Those vtables that do not have parents, we cannot merge. */
5763 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
5764 return true;
5766 /* If we've already been done, exit. */
5767 if (h->vtable_entries_used && h->vtable_entries_used[-1])
5768 return true;
5770 /* Make sure the parent's table is up to date. */
5771 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
5773 if (h->vtable_entries_used == NULL)
5775 /* None of this table's entries were referenced. Re-use the
5776 parent's table. */
5777 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
5778 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
5780 else
5782 size_t n;
5783 boolean *cu, *pu;
5785 /* Or the parent's entries into ours. */
5786 cu = h->vtable_entries_used;
5787 cu[-1] = true;
5788 pu = h->vtable_parent->vtable_entries_used;
5789 if (pu != NULL)
5791 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
5792 while (--n != 0)
5794 if (*pu) *cu = true;
5795 pu++, cu++;
5800 return true;
5803 static boolean
5804 elf_gc_smash_unused_vtentry_relocs (h, okp)
5805 struct elf_link_hash_entry *h;
5806 PTR okp;
5808 asection *sec;
5809 bfd_vma hstart, hend;
5810 Elf_Internal_Rela *relstart, *relend, *rel;
5812 /* Take care of both those symbols that do not describe vtables as
5813 well as those that are not loaded. */
5814 if (h->vtable_parent == NULL)
5815 return true;
5817 BFD_ASSERT (h->root.type == bfd_link_hash_defined
5818 || h->root.type == bfd_link_hash_defweak);
5820 sec = h->root.u.def.section;
5821 hstart = h->root.u.def.value;
5822 hend = hstart + h->size;
5824 relstart = (NAME(_bfd_elf,link_read_relocs)
5825 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
5826 if (!relstart)
5827 return *(boolean *)okp = false;
5828 relend = relstart + sec->reloc_count;
5830 for (rel = relstart; rel < relend; ++rel)
5831 if (rel->r_offset >= hstart && rel->r_offset < hend)
5833 /* If the entry is in use, do nothing. */
5834 if (h->vtable_entries_used
5835 && (rel->r_offset - hstart) < h->vtable_entries_size)
5837 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
5838 if (h->vtable_entries_used[entry])
5839 continue;
5841 /* Otherwise, kill it. */
5842 rel->r_offset = rel->r_info = rel->r_addend = 0;
5845 return true;
5848 /* Do mark and sweep of unused sections. */
5850 boolean
5851 elf_gc_sections (abfd, info)
5852 bfd *abfd;
5853 struct bfd_link_info *info;
5855 boolean ok = true;
5856 bfd *sub;
5857 asection * (*gc_mark_hook)
5858 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
5859 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
5861 if (!get_elf_backend_data (abfd)->can_gc_sections
5862 || info->relocateable
5863 || elf_hash_table (info)->dynamic_sections_created)
5864 return true;
5866 /* Apply transitive closure to the vtable entry usage info. */
5867 elf_link_hash_traverse (elf_hash_table (info),
5868 elf_gc_propagate_vtable_entries_used,
5869 (PTR) &ok);
5870 if (!ok)
5871 return false;
5873 /* Kill the vtable relocations that were not used. */
5874 elf_link_hash_traverse (elf_hash_table (info),
5875 elf_gc_smash_unused_vtentry_relocs,
5876 (PTR) &ok);
5877 if (!ok)
5878 return false;
5880 /* Grovel through relocs to find out who stays ... */
5882 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
5883 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
5885 asection *o;
5886 for (o = sub->sections; o != NULL; o = o->next)
5888 if (o->flags & SEC_KEEP)
5889 if (!elf_gc_mark (info, o, gc_mark_hook))
5890 return false;
5894 /* ... and mark SEC_EXCLUDE for those that go. */
5895 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
5896 return false;
5898 return true;
5901 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
5903 boolean
5904 elf_gc_record_vtinherit (abfd, sec, h, offset)
5905 bfd *abfd;
5906 asection *sec;
5907 struct elf_link_hash_entry *h;
5908 bfd_vma offset;
5910 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
5911 struct elf_link_hash_entry **search, *child;
5912 bfd_size_type extsymcount;
5914 /* The sh_info field of the symtab header tells us where the
5915 external symbols start. We don't care about the local symbols at
5916 this point. */
5917 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
5918 if (!elf_bad_symtab (abfd))
5919 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
5921 sym_hashes = elf_sym_hashes (abfd);
5922 sym_hashes_end = sym_hashes + extsymcount;
5924 /* Hunt down the child symbol, which is in this section at the same
5925 offset as the relocation. */
5926 for (search = sym_hashes; search != sym_hashes_end; ++search)
5928 if ((child = *search) != NULL
5929 && (child->root.type == bfd_link_hash_defined
5930 || child->root.type == bfd_link_hash_defweak)
5931 && child->root.u.def.section == sec
5932 && child->root.u.def.value == offset)
5933 goto win;
5936 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
5937 bfd_get_filename (abfd), sec->name,
5938 (unsigned long)offset);
5939 bfd_set_error (bfd_error_invalid_operation);
5940 return false;
5942 win:
5943 if (!h)
5945 /* This *should* only be the absolute section. It could potentially
5946 be that someone has defined a non-global vtable though, which
5947 would be bad. It isn't worth paging in the local symbols to be
5948 sure though; that case should simply be handled by the assembler. */
5950 child->vtable_parent = (struct elf_link_hash_entry *) -1;
5952 else
5953 child->vtable_parent = h;
5955 return true;
5958 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
5960 boolean
5961 elf_gc_record_vtentry (abfd, sec, h, addend)
5962 bfd *abfd;
5963 asection *sec;
5964 struct elf_link_hash_entry *h;
5965 bfd_vma addend;
5967 if (addend >= h->vtable_entries_size)
5969 size_t size, bytes;
5970 boolean *ptr = h->vtable_entries_used;
5972 /* While the symbol is undefined, we have to be prepared to handle
5973 a zero size. */
5974 if (h->root.type == bfd_link_hash_undefined)
5975 size = addend;
5976 else
5978 size = h->size;
5979 if (size < addend)
5981 /* Oops! We've got a reference past the defined end of
5982 the table. This is probably a bug -- shall we warn? */
5983 size = addend;
5987 /* Allocate one extra entry for use as a "done" flag for the
5988 consolidation pass. */
5989 bytes = (size / FILE_ALIGN + 1) * sizeof(boolean);
5991 if (ptr)
5993 size_t oldbytes;
5995 ptr = realloc (ptr-1, bytes);
5996 if (ptr == NULL)
5997 return false;
5999 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof(boolean);
6000 memset (ptr + oldbytes, 0, bytes - oldbytes);
6002 else
6004 ptr = calloc (1, bytes);
6005 if (ptr == NULL)
6006 return false;
6009 /* And arrange for that done flag to be at index -1. */
6010 h->vtable_entries_used = ptr+1;
6011 h->vtable_entries_size = size;
6013 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6015 return true;
6018 /* And an accompanying bit to work out final got entry offsets once
6019 we're done. Should be called from final_link. */
6021 boolean
6022 elf_gc_common_finalize_got_offsets (abfd, info)
6023 bfd *abfd;
6024 struct bfd_link_info *info;
6026 bfd *i;
6027 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6028 bfd_vma gotoff;
6030 /* The GOT offset is relative to the .got section, but the GOT header is
6031 put into the .got.plt section, if the backend uses it. */
6032 if (bed->want_got_plt)
6033 gotoff = 0;
6034 else
6035 gotoff = bed->got_header_size;
6037 /* Do the local .got entries first. */
6038 for (i = info->input_bfds; i; i = i->link_next)
6040 bfd_signed_vma *local_got = elf_local_got_refcounts (i);
6041 bfd_size_type j, locsymcount;
6042 Elf_Internal_Shdr *symtab_hdr;
6044 if (!local_got)
6045 continue;
6047 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6048 if (elf_bad_symtab (i))
6049 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6050 else
6051 locsymcount = symtab_hdr->sh_info;
6053 for (j = 0; j < locsymcount; ++j)
6055 if (local_got[j] > 0)
6057 local_got[j] = gotoff;
6058 gotoff += ARCH_SIZE / 8;
6060 else
6061 local_got[j] = (bfd_vma) -1;
6065 /* Then the global .got and .plt entries. */
6066 elf_link_hash_traverse (elf_hash_table (info),
6067 elf_gc_allocate_got_offsets,
6068 (PTR) &gotoff);
6069 return true;
6072 /* We need a special top-level link routine to convert got reference counts
6073 to real got offsets. */
6075 static boolean
6076 elf_gc_allocate_got_offsets (h, offarg)
6077 struct elf_link_hash_entry *h;
6078 PTR offarg;
6080 bfd_vma *off = (bfd_vma *) offarg;
6082 if (h->got.refcount > 0)
6084 h->got.offset = off[0];
6085 off[0] += ARCH_SIZE / 8;
6087 else
6088 h->got.offset = (bfd_vma) -1;
6090 return true;
6093 /* Many folk need no more in the way of final link than this, once
6094 got entry reference counting is enabled. */
6096 boolean
6097 elf_gc_common_final_link (abfd, info)
6098 bfd *abfd;
6099 struct bfd_link_info *info;
6101 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6102 return false;
6104 /* Invoke the regular ELF backend linker to do all the work. */
6105 return elf_bfd_final_link (abfd, info);
6108 /* This function will be called though elf_link_hash_traverse to store
6109 all hash value of the exported symbols in an array. */
6111 static boolean
6112 elf_collect_hash_codes (h, data)
6113 struct elf_link_hash_entry *h;
6114 PTR data;
6116 unsigned long **valuep = (unsigned long **) data;
6117 const char *name;
6118 char *p;
6119 unsigned long ha;
6120 char *alc = NULL;
6122 /* Ignore indirect symbols. These are added by the versioning code. */
6123 if (h->dynindx == -1)
6124 return true;
6126 name = h->root.root.string;
6127 p = strchr (name, ELF_VER_CHR);
6128 if (p != NULL)
6130 alc = bfd_malloc (p - name + 1);
6131 memcpy (alc, name, p - name);
6132 alc[p - name] = '\0';
6133 name = alc;
6136 /* Compute the hash value. */
6137 ha = bfd_elf_hash (name);
6139 /* Store the found hash value in the array given as the argument. */
6140 *(*valuep)++ = ha;
6142 /* And store it in the struct so that we can put it in the hash table
6143 later. */
6144 h->elf_hash_value = ha;
6146 if (alc != NULL)
6147 free (alc);
6149 return true;