* elf-bfd.h (_bfd_elf_link_adjust_dynindx): New function.
[binutils.git] / bfd / elflink.h
blob88fd05c200f85789821001f498e1686405db3e04
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));
55 static boolean elf_link_read_relocs_from_section
56 PARAMS ((bfd *, Elf_Internal_Shdr *, PTR, Elf_Internal_Rela *));
57 static void elf_link_remove_section_and_adjust_dynindices
58 PARAMS ((bfd *, struct bfd_link_info *, asection *));
60 /* Given an ELF BFD, add symbols to the global hash table as
61 appropriate. */
63 boolean
64 elf_bfd_link_add_symbols (abfd, info)
65 bfd *abfd;
66 struct bfd_link_info *info;
68 switch (bfd_get_format (abfd))
70 case bfd_object:
71 return elf_link_add_object_symbols (abfd, info);
72 case bfd_archive:
73 return elf_link_add_archive_symbols (abfd, info);
74 default:
75 bfd_set_error (bfd_error_wrong_format);
76 return false;
81 /* Add symbols from an ELF archive file to the linker hash table. We
82 don't use _bfd_generic_link_add_archive_symbols because of a
83 problem which arises on UnixWare. The UnixWare libc.so is an
84 archive which includes an entry libc.so.1 which defines a bunch of
85 symbols. The libc.so archive also includes a number of other
86 object files, which also define symbols, some of which are the same
87 as those defined in libc.so.1. Correct linking requires that we
88 consider each object file in turn, and include it if it defines any
89 symbols we need. _bfd_generic_link_add_archive_symbols does not do
90 this; it looks through the list of undefined symbols, and includes
91 any object file which defines them. When this algorithm is used on
92 UnixWare, it winds up pulling in libc.so.1 early and defining a
93 bunch of symbols. This means that some of the other objects in the
94 archive are not included in the link, which is incorrect since they
95 precede libc.so.1 in the archive.
97 Fortunately, ELF archive handling is simpler than that done by
98 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
99 oddities. In ELF, if we find a symbol in the archive map, and the
100 symbol is currently undefined, we know that we must pull in that
101 object file.
103 Unfortunately, we do have to make multiple passes over the symbol
104 table until nothing further is resolved. */
106 static boolean
107 elf_link_add_archive_symbols (abfd, info)
108 bfd *abfd;
109 struct bfd_link_info *info;
111 symindex c;
112 boolean *defined = NULL;
113 boolean *included = NULL;
114 carsym *symdefs;
115 boolean loop;
117 if (! bfd_has_map (abfd))
119 /* An empty archive is a special case. */
120 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
121 return true;
122 bfd_set_error (bfd_error_no_armap);
123 return false;
126 /* Keep track of all symbols we know to be already defined, and all
127 files we know to be already included. This is to speed up the
128 second and subsequent passes. */
129 c = bfd_ardata (abfd)->symdef_count;
130 if (c == 0)
131 return true;
132 defined = (boolean *) bfd_malloc (c * sizeof (boolean));
133 included = (boolean *) bfd_malloc (c * sizeof (boolean));
134 if (defined == (boolean *) NULL || included == (boolean *) NULL)
135 goto error_return;
136 memset (defined, 0, c * sizeof (boolean));
137 memset (included, 0, c * sizeof (boolean));
139 symdefs = bfd_ardata (abfd)->symdefs;
143 file_ptr last;
144 symindex i;
145 carsym *symdef;
146 carsym *symdefend;
148 loop = false;
149 last = -1;
151 symdef = symdefs;
152 symdefend = symdef + c;
153 for (i = 0; symdef < symdefend; symdef++, i++)
155 struct elf_link_hash_entry *h;
156 bfd *element;
157 struct bfd_link_hash_entry *undefs_tail;
158 symindex mark;
160 if (defined[i] || included[i])
161 continue;
162 if (symdef->file_offset == last)
164 included[i] = true;
165 continue;
168 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
169 false, false, false);
171 if (h == NULL)
173 char *p, *copy;
175 /* If this is a default version (the name contains @@),
176 look up the symbol again without the version. The
177 effect is that references to the symbol without the
178 version will be matched by the default symbol in the
179 archive. */
181 p = strchr (symdef->name, ELF_VER_CHR);
182 if (p == NULL || p[1] != ELF_VER_CHR)
183 continue;
185 copy = bfd_alloc (abfd, p - symdef->name + 1);
186 if (copy == NULL)
187 goto error_return;
188 memcpy (copy, symdef->name, p - symdef->name);
189 copy[p - symdef->name] = '\0';
191 h = elf_link_hash_lookup (elf_hash_table (info), copy,
192 false, false, false);
194 bfd_release (abfd, copy);
197 if (h == NULL)
198 continue;
200 if (h->root.type != bfd_link_hash_undefined)
202 if (h->root.type != bfd_link_hash_undefweak)
203 defined[i] = true;
204 continue;
207 /* We need to include this archive member. */
209 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
210 if (element == (bfd *) NULL)
211 goto error_return;
213 if (! bfd_check_format (element, bfd_object))
214 goto error_return;
216 /* Doublecheck that we have not included this object
217 already--it should be impossible, but there may be
218 something wrong with the archive. */
219 if (element->archive_pass != 0)
221 bfd_set_error (bfd_error_bad_value);
222 goto error_return;
224 element->archive_pass = 1;
226 undefs_tail = info->hash->undefs_tail;
228 if (! (*info->callbacks->add_archive_element) (info, element,
229 symdef->name))
230 goto error_return;
231 if (! elf_link_add_object_symbols (element, info))
232 goto error_return;
234 /* If there are any new undefined symbols, we need to make
235 another pass through the archive in order to see whether
236 they can be defined. FIXME: This isn't perfect, because
237 common symbols wind up on undefs_tail and because an
238 undefined symbol which is defined later on in this pass
239 does not require another pass. This isn't a bug, but it
240 does make the code less efficient than it could be. */
241 if (undefs_tail != info->hash->undefs_tail)
242 loop = true;
244 /* Look backward to mark all symbols from this object file
245 which we have already seen in this pass. */
246 mark = i;
249 included[mark] = true;
250 if (mark == 0)
251 break;
252 --mark;
254 while (symdefs[mark].file_offset == symdef->file_offset);
256 /* We mark subsequent symbols from this object file as we go
257 on through the loop. */
258 last = symdef->file_offset;
261 while (loop);
263 free (defined);
264 free (included);
266 return true;
268 error_return:
269 if (defined != (boolean *) NULL)
270 free (defined);
271 if (included != (boolean *) NULL)
272 free (included);
273 return false;
276 /* This function is called when we want to define a new symbol. It
277 handles the various cases which arise when we find a definition in
278 a dynamic object, or when there is already a definition in a
279 dynamic object. The new symbol is described by NAME, SYM, PSEC,
280 and PVALUE. We set SYM_HASH to the hash table entry. We set
281 OVERRIDE if the old symbol is overriding a new definition. We set
282 TYPE_CHANGE_OK if it is OK for the type to change. We set
283 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
284 change, we mean that we shouldn't warn if the type or size does
285 change. */
287 static boolean
288 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
289 override, type_change_ok, size_change_ok)
290 bfd *abfd;
291 struct bfd_link_info *info;
292 const char *name;
293 Elf_Internal_Sym *sym;
294 asection **psec;
295 bfd_vma *pvalue;
296 struct elf_link_hash_entry **sym_hash;
297 boolean *override;
298 boolean *type_change_ok;
299 boolean *size_change_ok;
301 asection *sec;
302 struct elf_link_hash_entry *h;
303 int bind;
304 bfd *oldbfd;
305 boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
307 *override = false;
309 sec = *psec;
310 bind = ELF_ST_BIND (sym->st_info);
312 if (! bfd_is_und_section (sec))
313 h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
314 else
315 h = ((struct elf_link_hash_entry *)
316 bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
317 if (h == NULL)
318 return false;
319 *sym_hash = h;
321 /* This code is for coping with dynamic objects, and is only useful
322 if we are doing an ELF link. */
323 if (info->hash->creator != abfd->xvec)
324 return true;
326 /* For merging, we only care about real symbols. */
328 while (h->root.type == bfd_link_hash_indirect
329 || h->root.type == bfd_link_hash_warning)
330 h = (struct elf_link_hash_entry *) h->root.u.i.link;
332 /* If we just created the symbol, mark it as being an ELF symbol.
333 Other than that, there is nothing to do--there is no merge issue
334 with a newly defined symbol--so we just return. */
336 if (h->root.type == bfd_link_hash_new)
338 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
339 return true;
342 /* OLDBFD is a BFD associated with the existing symbol. */
344 switch (h->root.type)
346 default:
347 oldbfd = NULL;
348 break;
350 case bfd_link_hash_undefined:
351 case bfd_link_hash_undefweak:
352 oldbfd = h->root.u.undef.abfd;
353 break;
355 case bfd_link_hash_defined:
356 case bfd_link_hash_defweak:
357 oldbfd = h->root.u.def.section->owner;
358 break;
360 case bfd_link_hash_common:
361 oldbfd = h->root.u.c.p->section->owner;
362 break;
365 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
366 respectively, is from a dynamic object. */
368 if ((abfd->flags & DYNAMIC) != 0)
369 newdyn = true;
370 else
371 newdyn = false;
373 if (oldbfd == NULL || (oldbfd->flags & DYNAMIC) == 0)
374 olddyn = false;
375 else
376 olddyn = true;
378 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
379 respectively, appear to be a definition rather than reference. */
381 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
382 newdef = false;
383 else
384 newdef = true;
386 if (h->root.type == bfd_link_hash_undefined
387 || h->root.type == bfd_link_hash_undefweak
388 || h->root.type == bfd_link_hash_common)
389 olddef = false;
390 else
391 olddef = true;
393 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
394 symbol, respectively, appears to be a common symbol in a dynamic
395 object. If a symbol appears in an uninitialized section, and is
396 not weak, and is not a function, then it may be a common symbol
397 which was resolved when the dynamic object was created. We want
398 to treat such symbols specially, because they raise special
399 considerations when setting the symbol size: if the symbol
400 appears as a common symbol in a regular object, and the size in
401 the regular object is larger, we must make sure that we use the
402 larger size. This problematic case can always be avoided in C,
403 but it must be handled correctly when using Fortran shared
404 libraries.
406 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
407 likewise for OLDDYNCOMMON and OLDDEF.
409 Note that this test is just a heuristic, and that it is quite
410 possible to have an uninitialized symbol in a shared object which
411 is really a definition, rather than a common symbol. This could
412 lead to some minor confusion when the symbol really is a common
413 symbol in some regular object. However, I think it will be
414 harmless. */
416 if (newdyn
417 && newdef
418 && (sec->flags & SEC_ALLOC) != 0
419 && (sec->flags & SEC_LOAD) == 0
420 && sym->st_size > 0
421 && bind != STB_WEAK
422 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
423 newdyncommon = true;
424 else
425 newdyncommon = false;
427 if (olddyn
428 && olddef
429 && h->root.type == bfd_link_hash_defined
430 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
431 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
432 && (h->root.u.def.section->flags & SEC_LOAD) == 0
433 && h->size > 0
434 && h->type != STT_FUNC)
435 olddyncommon = true;
436 else
437 olddyncommon = false;
439 /* It's OK to change the type if either the existing symbol or the
440 new symbol is weak. */
442 if (h->root.type == bfd_link_hash_defweak
443 || h->root.type == bfd_link_hash_undefweak
444 || bind == STB_WEAK)
445 *type_change_ok = true;
447 /* It's OK to change the size if either the existing symbol or the
448 new symbol is weak, or if the old symbol is undefined. */
450 if (*type_change_ok
451 || h->root.type == bfd_link_hash_undefined)
452 *size_change_ok = true;
454 /* If both the old and the new symbols look like common symbols in a
455 dynamic object, set the size of the symbol to the larger of the
456 two. */
458 if (olddyncommon
459 && newdyncommon
460 && sym->st_size != h->size)
462 /* Since we think we have two common symbols, issue a multiple
463 common warning if desired. Note that we only warn if the
464 size is different. If the size is the same, we simply let
465 the old symbol override the new one as normally happens with
466 symbols defined in dynamic objects. */
468 if (! ((*info->callbacks->multiple_common)
469 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
470 h->size, abfd, bfd_link_hash_common, sym->st_size)))
471 return false;
473 if (sym->st_size > h->size)
474 h->size = sym->st_size;
476 *size_change_ok = true;
479 /* If we are looking at a dynamic object, and we have found a
480 definition, we need to see if the symbol was already defined by
481 some other object. If so, we want to use the existing
482 definition, and we do not want to report a multiple symbol
483 definition error; we do this by clobbering *PSEC to be
484 bfd_und_section_ptr.
486 We treat a common symbol as a definition if the symbol in the
487 shared library is a function, since common symbols always
488 represent variables; this can cause confusion in principle, but
489 any such confusion would seem to indicate an erroneous program or
490 shared library. We also permit a common symbol in a regular
491 object to override a weak symbol in a shared object. */
493 if (newdyn
494 && newdef
495 && (olddef
496 || (h->root.type == bfd_link_hash_common
497 && (bind == STB_WEAK
498 || ELF_ST_TYPE (sym->st_info) == STT_FUNC))))
500 *override = true;
501 newdef = false;
502 newdyncommon = false;
504 *psec = sec = bfd_und_section_ptr;
505 *size_change_ok = true;
507 /* If we get here when the old symbol is a common symbol, then
508 we are explicitly letting it override a weak symbol or
509 function in a dynamic object, and we don't want to warn about
510 a type change. If the old symbol is a defined symbol, a type
511 change warning may still be appropriate. */
513 if (h->root.type == bfd_link_hash_common)
514 *type_change_ok = true;
517 /* Handle the special case of an old common symbol merging with a
518 new symbol which looks like a common symbol in a shared object.
519 We change *PSEC and *PVALUE to make the new symbol look like a
520 common symbol, and let _bfd_generic_link_add_one_symbol will do
521 the right thing. */
523 if (newdyncommon
524 && h->root.type == bfd_link_hash_common)
526 *override = true;
527 newdef = false;
528 newdyncommon = false;
529 *pvalue = sym->st_size;
530 *psec = sec = bfd_com_section_ptr;
531 *size_change_ok = true;
534 /* If the old symbol is from a dynamic object, and the new symbol is
535 a definition which is not from a dynamic object, then the new
536 symbol overrides the old symbol. Symbols from regular files
537 always take precedence over symbols from dynamic objects, even if
538 they are defined after the dynamic object in the link.
540 As above, we again permit a common symbol in a regular object to
541 override a definition in a shared object if the shared object
542 symbol is a function or is weak. */
544 if (! newdyn
545 && (newdef
546 || (bfd_is_com_section (sec)
547 && (h->root.type == bfd_link_hash_defweak
548 || h->type == STT_FUNC)))
549 && olddyn
550 && olddef
551 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
553 /* Change the hash table entry to undefined, and let
554 _bfd_generic_link_add_one_symbol do the right thing with the
555 new definition. */
557 h->root.type = bfd_link_hash_undefined;
558 h->root.u.undef.abfd = h->root.u.def.section->owner;
559 *size_change_ok = true;
561 olddef = false;
562 olddyncommon = false;
564 /* We again permit a type change when a common symbol may be
565 overriding a function. */
567 if (bfd_is_com_section (sec))
568 *type_change_ok = true;
570 /* This union may have been set to be non-NULL when this symbol
571 was seen in a dynamic object. We must force the union to be
572 NULL, so that it is correct for a regular symbol. */
574 h->verinfo.vertree = NULL;
576 /* In this special case, if H is the target of an indirection,
577 we want the caller to frob with H rather than with the
578 indirect symbol. That will permit the caller to redefine the
579 target of the indirection, rather than the indirect symbol
580 itself. FIXME: This will break the -y option if we store a
581 symbol with a different name. */
582 *sym_hash = h;
585 /* Handle the special case of a new common symbol merging with an
586 old symbol that looks like it might be a common symbol defined in
587 a shared object. Note that we have already handled the case in
588 which a new common symbol should simply override the definition
589 in the shared library. */
591 if (! newdyn
592 && bfd_is_com_section (sec)
593 && olddyncommon)
595 /* It would be best if we could set the hash table entry to a
596 common symbol, but we don't know what to use for the section
597 or the alignment. */
598 if (! ((*info->callbacks->multiple_common)
599 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
600 h->size, abfd, bfd_link_hash_common, sym->st_size)))
601 return false;
603 /* If the predumed common symbol in the dynamic object is
604 larger, pretend that the new symbol has its size. */
606 if (h->size > *pvalue)
607 *pvalue = h->size;
609 /* FIXME: We no longer know the alignment required by the symbol
610 in the dynamic object, so we just wind up using the one from
611 the regular object. */
613 olddef = false;
614 olddyncommon = false;
616 h->root.type = bfd_link_hash_undefined;
617 h->root.u.undef.abfd = h->root.u.def.section->owner;
619 *size_change_ok = true;
620 *type_change_ok = true;
622 h->verinfo.vertree = NULL;
625 return true;
628 /* Add symbols from an ELF object file to the linker hash table. */
630 static boolean
631 elf_link_add_object_symbols (abfd, info)
632 bfd *abfd;
633 struct bfd_link_info *info;
635 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
636 const Elf_Internal_Sym *,
637 const char **, flagword *,
638 asection **, bfd_vma *));
639 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
640 asection *, const Elf_Internal_Rela *));
641 boolean collect;
642 Elf_Internal_Shdr *hdr;
643 size_t symcount;
644 size_t extsymcount;
645 size_t extsymoff;
646 Elf_External_Sym *buf = NULL;
647 struct elf_link_hash_entry **sym_hash;
648 boolean dynamic;
649 bfd_byte *dynver = NULL;
650 Elf_External_Versym *extversym = NULL;
651 Elf_External_Versym *ever;
652 Elf_External_Dyn *dynbuf = NULL;
653 struct elf_link_hash_entry *weaks;
654 Elf_External_Sym *esym;
655 Elf_External_Sym *esymend;
657 add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
658 collect = get_elf_backend_data (abfd)->collect;
660 if ((abfd->flags & DYNAMIC) == 0)
661 dynamic = false;
662 else
664 dynamic = true;
666 /* You can't use -r against a dynamic object. Also, there's no
667 hope of using a dynamic object which does not exactly match
668 the format of the output file. */
669 if (info->relocateable || info->hash->creator != abfd->xvec)
671 bfd_set_error (bfd_error_invalid_operation);
672 goto error_return;
676 /* As a GNU extension, any input sections which are named
677 .gnu.warning.SYMBOL are treated as warning symbols for the given
678 symbol. This differs from .gnu.warning sections, which generate
679 warnings when they are included in an output file. */
680 if (! info->shared)
682 asection *s;
684 for (s = abfd->sections; s != NULL; s = s->next)
686 const char *name;
688 name = bfd_get_section_name (abfd, s);
689 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
691 char *msg;
692 bfd_size_type sz;
694 name += sizeof ".gnu.warning." - 1;
696 /* If this is a shared object, then look up the symbol
697 in the hash table. If it is there, and it is already
698 been defined, then we will not be using the entry
699 from this shared object, so we don't need to warn.
700 FIXME: If we see the definition in a regular object
701 later on, we will warn, but we shouldn't. The only
702 fix is to keep track of what warnings we are supposed
703 to emit, and then handle them all at the end of the
704 link. */
705 if (dynamic && abfd->xvec == info->hash->creator)
707 struct elf_link_hash_entry *h;
709 h = elf_link_hash_lookup (elf_hash_table (info), name,
710 false, false, true);
712 /* FIXME: What about bfd_link_hash_common? */
713 if (h != NULL
714 && (h->root.type == bfd_link_hash_defined
715 || h->root.type == bfd_link_hash_defweak))
717 /* We don't want to issue this warning. Clobber
718 the section size so that the warning does not
719 get copied into the output file. */
720 s->_raw_size = 0;
721 continue;
725 sz = bfd_section_size (abfd, s);
726 msg = (char *) bfd_alloc (abfd, sz + 1);
727 if (msg == NULL)
728 goto error_return;
730 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
731 goto error_return;
733 msg[sz] = '\0';
735 if (! (_bfd_generic_link_add_one_symbol
736 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
737 false, collect, (struct bfd_link_hash_entry **) NULL)))
738 goto error_return;
740 if (! info->relocateable)
742 /* Clobber the section size so that the warning does
743 not get copied into the output file. */
744 s->_raw_size = 0;
750 /* If this is a dynamic object, we always link against the .dynsym
751 symbol table, not the .symtab symbol table. The dynamic linker
752 will only see the .dynsym symbol table, so there is no reason to
753 look at .symtab for a dynamic object. */
755 if (! dynamic || elf_dynsymtab (abfd) == 0)
756 hdr = &elf_tdata (abfd)->symtab_hdr;
757 else
758 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
760 if (dynamic)
762 /* Read in any version definitions. */
764 if (! _bfd_elf_slurp_version_tables (abfd))
765 goto error_return;
767 /* Read in the symbol versions, but don't bother to convert them
768 to internal format. */
769 if (elf_dynversym (abfd) != 0)
771 Elf_Internal_Shdr *versymhdr;
773 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
774 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
775 if (extversym == NULL)
776 goto error_return;
777 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
778 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
779 != versymhdr->sh_size))
780 goto error_return;
784 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
786 /* The sh_info field of the symtab header tells us where the
787 external symbols start. We don't care about the local symbols at
788 this point. */
789 if (elf_bad_symtab (abfd))
791 extsymcount = symcount;
792 extsymoff = 0;
794 else
796 extsymcount = symcount - hdr->sh_info;
797 extsymoff = hdr->sh_info;
800 buf = ((Elf_External_Sym *)
801 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
802 if (buf == NULL && extsymcount != 0)
803 goto error_return;
805 /* We store a pointer to the hash table entry for each external
806 symbol. */
807 sym_hash = ((struct elf_link_hash_entry **)
808 bfd_alloc (abfd,
809 extsymcount * sizeof (struct elf_link_hash_entry *)));
810 if (sym_hash == NULL)
811 goto error_return;
812 elf_sym_hashes (abfd) = sym_hash;
814 if (! dynamic)
816 /* If we are creating a shared library, create all the dynamic
817 sections immediately. We need to attach them to something,
818 so we attach them to this BFD, provided it is the right
819 format. FIXME: If there are no input BFD's of the same
820 format as the output, we can't make a shared library. */
821 if (info->shared
822 && ! elf_hash_table (info)->dynamic_sections_created
823 && abfd->xvec == info->hash->creator)
825 if (! elf_link_create_dynamic_sections (abfd, info))
826 goto error_return;
829 else
831 asection *s;
832 boolean add_needed;
833 const char *name;
834 bfd_size_type oldsize;
835 bfd_size_type strindex;
837 /* Find the name to use in a DT_NEEDED entry that refers to this
838 object. If the object has a DT_SONAME entry, we use it.
839 Otherwise, if the generic linker stuck something in
840 elf_dt_name, we use that. Otherwise, we just use the file
841 name. If the generic linker put a null string into
842 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
843 there is a DT_SONAME entry. */
844 add_needed = true;
845 name = bfd_get_filename (abfd);
846 if (elf_dt_name (abfd) != NULL)
848 name = elf_dt_name (abfd);
849 if (*name == '\0')
850 add_needed = false;
852 s = bfd_get_section_by_name (abfd, ".dynamic");
853 if (s != NULL)
855 Elf_External_Dyn *extdyn;
856 Elf_External_Dyn *extdynend;
857 int elfsec;
858 unsigned long link;
860 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
861 if (dynbuf == NULL)
862 goto error_return;
864 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
865 (file_ptr) 0, s->_raw_size))
866 goto error_return;
868 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
869 if (elfsec == -1)
870 goto error_return;
871 link = elf_elfsections (abfd)[elfsec]->sh_link;
873 extdyn = dynbuf;
874 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
875 for (; extdyn < extdynend; extdyn++)
877 Elf_Internal_Dyn dyn;
879 elf_swap_dyn_in (abfd, extdyn, &dyn);
880 if (dyn.d_tag == DT_SONAME)
882 name = bfd_elf_string_from_elf_section (abfd, link,
883 dyn.d_un.d_val);
884 if (name == NULL)
885 goto error_return;
887 if (dyn.d_tag == DT_NEEDED)
889 struct bfd_link_needed_list *n, **pn;
890 char *fnm, *anm;
892 n = ((struct bfd_link_needed_list *)
893 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
894 fnm = bfd_elf_string_from_elf_section (abfd, link,
895 dyn.d_un.d_val);
896 if (n == NULL || fnm == NULL)
897 goto error_return;
898 anm = bfd_alloc (abfd, strlen (fnm) + 1);
899 if (anm == NULL)
900 goto error_return;
901 strcpy (anm, fnm);
902 n->name = anm;
903 n->by = abfd;
904 n->next = NULL;
905 for (pn = &elf_hash_table (info)->needed;
906 *pn != NULL;
907 pn = &(*pn)->next)
909 *pn = n;
913 free (dynbuf);
914 dynbuf = NULL;
917 /* We do not want to include any of the sections in a dynamic
918 object in the output file. We hack by simply clobbering the
919 list of sections in the BFD. This could be handled more
920 cleanly by, say, a new section flag; the existing
921 SEC_NEVER_LOAD flag is not the one we want, because that one
922 still implies that the section takes up space in the output
923 file. */
924 abfd->sections = NULL;
925 abfd->section_count = 0;
927 /* If this is the first dynamic object found in the link, create
928 the special sections required for dynamic linking. */
929 if (! elf_hash_table (info)->dynamic_sections_created)
931 if (! elf_link_create_dynamic_sections (abfd, info))
932 goto error_return;
935 if (add_needed)
937 /* Add a DT_NEEDED entry for this dynamic object. */
938 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
939 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
940 true, false);
941 if (strindex == (bfd_size_type) -1)
942 goto error_return;
944 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
946 asection *sdyn;
947 Elf_External_Dyn *dyncon, *dynconend;
949 /* The hash table size did not change, which means that
950 the dynamic object name was already entered. If we
951 have already included this dynamic object in the
952 link, just ignore it. There is no reason to include
953 a particular dynamic object more than once. */
954 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
955 ".dynamic");
956 BFD_ASSERT (sdyn != NULL);
958 dyncon = (Elf_External_Dyn *) sdyn->contents;
959 dynconend = (Elf_External_Dyn *) (sdyn->contents +
960 sdyn->_raw_size);
961 for (; dyncon < dynconend; dyncon++)
963 Elf_Internal_Dyn dyn;
965 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
966 &dyn);
967 if (dyn.d_tag == DT_NEEDED
968 && dyn.d_un.d_val == strindex)
970 if (buf != NULL)
971 free (buf);
972 if (extversym != NULL)
973 free (extversym);
974 return true;
979 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
980 goto error_return;
983 /* Save the SONAME, if there is one, because sometimes the
984 linker emulation code will need to know it. */
985 if (*name == '\0')
986 name = bfd_get_filename (abfd);
987 elf_dt_name (abfd) = name;
990 if (bfd_seek (abfd,
991 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
992 SEEK_SET) != 0
993 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
994 != extsymcount * sizeof (Elf_External_Sym)))
995 goto error_return;
997 weaks = NULL;
999 ever = extversym != NULL ? extversym + extsymoff : NULL;
1000 esymend = buf + extsymcount;
1001 for (esym = buf;
1002 esym < esymend;
1003 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1005 Elf_Internal_Sym sym;
1006 int bind;
1007 bfd_vma value;
1008 asection *sec;
1009 flagword flags;
1010 const char *name;
1011 struct elf_link_hash_entry *h;
1012 boolean definition;
1013 boolean size_change_ok, type_change_ok;
1014 boolean new_weakdef;
1015 unsigned int old_alignment;
1017 elf_swap_symbol_in (abfd, esym, &sym);
1019 flags = BSF_NO_FLAGS;
1020 sec = NULL;
1021 value = sym.st_value;
1022 *sym_hash = NULL;
1024 bind = ELF_ST_BIND (sym.st_info);
1025 if (bind == STB_LOCAL)
1027 /* This should be impossible, since ELF requires that all
1028 global symbols follow all local symbols, and that sh_info
1029 point to the first global symbol. Unfortunatealy, Irix 5
1030 screws this up. */
1031 continue;
1033 else if (bind == STB_GLOBAL)
1035 if (sym.st_shndx != SHN_UNDEF
1036 && sym.st_shndx != SHN_COMMON)
1037 flags = BSF_GLOBAL;
1038 else
1039 flags = 0;
1041 else if (bind == STB_WEAK)
1042 flags = BSF_WEAK;
1043 else
1045 /* Leave it up to the processor backend. */
1048 if (sym.st_shndx == SHN_UNDEF)
1049 sec = bfd_und_section_ptr;
1050 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1052 sec = section_from_elf_index (abfd, sym.st_shndx);
1053 if (sec == NULL)
1054 sec = bfd_abs_section_ptr;
1055 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1056 value -= sec->vma;
1058 else if (sym.st_shndx == SHN_ABS)
1059 sec = bfd_abs_section_ptr;
1060 else if (sym.st_shndx == SHN_COMMON)
1062 sec = bfd_com_section_ptr;
1063 /* What ELF calls the size we call the value. What ELF
1064 calls the value we call the alignment. */
1065 value = sym.st_size;
1067 else
1069 /* Leave it up to the processor backend. */
1072 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1073 if (name == (const char *) NULL)
1074 goto error_return;
1076 if (add_symbol_hook)
1078 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1079 &value))
1080 goto error_return;
1082 /* The hook function sets the name to NULL if this symbol
1083 should be skipped for some reason. */
1084 if (name == (const char *) NULL)
1085 continue;
1088 /* Sanity check that all possibilities were handled. */
1089 if (sec == (asection *) NULL)
1091 bfd_set_error (bfd_error_bad_value);
1092 goto error_return;
1095 if (bfd_is_und_section (sec)
1096 || bfd_is_com_section (sec))
1097 definition = false;
1098 else
1099 definition = true;
1101 size_change_ok = false;
1102 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1103 old_alignment = 0;
1104 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1106 Elf_Internal_Versym iver;
1107 unsigned int vernum = 0;
1108 boolean override;
1110 if (ever != NULL)
1112 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1113 vernum = iver.vs_vers & VERSYM_VERSION;
1115 /* If this is a hidden symbol, or if it is not version
1116 1, we append the version name to the symbol name.
1117 However, we do not modify a non-hidden absolute
1118 symbol, because it might be the version symbol
1119 itself. FIXME: What if it isn't? */
1120 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1121 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1123 const char *verstr;
1124 int namelen, newlen;
1125 char *newname, *p;
1127 if (sym.st_shndx != SHN_UNDEF)
1129 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1131 (*_bfd_error_handler)
1132 (_("%s: %s: invalid version %u (max %d)"),
1133 bfd_get_filename (abfd), name, vernum,
1134 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1135 bfd_set_error (bfd_error_bad_value);
1136 goto error_return;
1138 else if (vernum > 1)
1139 verstr =
1140 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1141 else
1142 verstr = "";
1144 else
1146 /* We cannot simply test for the number of
1147 entries in the VERNEED section since the
1148 numbers for the needed versions do not start
1149 at 0. */
1150 Elf_Internal_Verneed *t;
1152 verstr = NULL;
1153 for (t = elf_tdata (abfd)->verref;
1154 t != NULL;
1155 t = t->vn_nextref)
1157 Elf_Internal_Vernaux *a;
1159 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1161 if (a->vna_other == vernum)
1163 verstr = a->vna_nodename;
1164 break;
1167 if (a != NULL)
1168 break;
1170 if (verstr == NULL)
1172 (*_bfd_error_handler)
1173 (_("%s: %s: invalid needed version %d"),
1174 bfd_get_filename (abfd), name, vernum);
1175 bfd_set_error (bfd_error_bad_value);
1176 goto error_return;
1180 namelen = strlen (name);
1181 newlen = namelen + strlen (verstr) + 2;
1182 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1183 ++newlen;
1185 newname = (char *) bfd_alloc (abfd, newlen);
1186 if (newname == NULL)
1187 goto error_return;
1188 strcpy (newname, name);
1189 p = newname + namelen;
1190 *p++ = ELF_VER_CHR;
1191 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1192 *p++ = ELF_VER_CHR;
1193 strcpy (p, verstr);
1195 name = newname;
1199 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1200 sym_hash, &override, &type_change_ok,
1201 &size_change_ok))
1202 goto error_return;
1204 if (override)
1205 definition = false;
1207 h = *sym_hash;
1208 while (h->root.type == bfd_link_hash_indirect
1209 || h->root.type == bfd_link_hash_warning)
1210 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1212 /* Remember the old alignment if this is a common symbol, so
1213 that we don't reduce the alignment later on. We can't
1214 check later, because _bfd_generic_link_add_one_symbol
1215 will set a default for the alignment which we want to
1216 override. */
1217 if (h->root.type == bfd_link_hash_common)
1218 old_alignment = h->root.u.c.p->alignment_power;
1220 if (elf_tdata (abfd)->verdef != NULL
1221 && ! override
1222 && vernum > 1
1223 && definition)
1224 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1227 if (! (_bfd_generic_link_add_one_symbol
1228 (info, abfd, name, flags, sec, value, (const char *) NULL,
1229 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1230 goto error_return;
1232 h = *sym_hash;
1233 while (h->root.type == bfd_link_hash_indirect
1234 || h->root.type == bfd_link_hash_warning)
1235 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1236 *sym_hash = h;
1238 new_weakdef = false;
1239 if (dynamic
1240 && definition
1241 && (flags & BSF_WEAK) != 0
1242 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1243 && info->hash->creator->flavour == bfd_target_elf_flavour
1244 && h->weakdef == NULL)
1246 /* Keep a list of all weak defined non function symbols from
1247 a dynamic object, using the weakdef field. Later in this
1248 function we will set the weakdef field to the correct
1249 value. We only put non-function symbols from dynamic
1250 objects on this list, because that happens to be the only
1251 time we need to know the normal symbol corresponding to a
1252 weak symbol, and the information is time consuming to
1253 figure out. If the weakdef field is not already NULL,
1254 then this symbol was already defined by some previous
1255 dynamic object, and we will be using that previous
1256 definition anyhow. */
1258 h->weakdef = weaks;
1259 weaks = h;
1260 new_weakdef = true;
1263 /* Set the alignment of a common symbol. */
1264 if (sym.st_shndx == SHN_COMMON
1265 && h->root.type == bfd_link_hash_common)
1267 unsigned int align;
1269 align = bfd_log2 (sym.st_value);
1270 if (align > old_alignment)
1271 h->root.u.c.p->alignment_power = align;
1274 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1276 int old_flags;
1277 boolean dynsym;
1278 int new_flag;
1280 /* Remember the symbol size and type. */
1281 if (sym.st_size != 0
1282 && (definition || h->size == 0))
1284 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1285 (*_bfd_error_handler)
1286 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1287 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1288 bfd_get_filename (abfd));
1290 h->size = sym.st_size;
1293 /* If this is a common symbol, then we always want H->SIZE
1294 to be the size of the common symbol. The code just above
1295 won't fix the size if a common symbol becomes larger. We
1296 don't warn about a size change here, because that is
1297 covered by --warn-common. */
1298 if (h->root.type == bfd_link_hash_common)
1299 h->size = h->root.u.c.size;
1301 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1302 && (definition || h->type == STT_NOTYPE))
1304 if (h->type != STT_NOTYPE
1305 && h->type != ELF_ST_TYPE (sym.st_info)
1306 && ! type_change_ok)
1307 (*_bfd_error_handler)
1308 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1309 name, h->type, ELF_ST_TYPE (sym.st_info),
1310 bfd_get_filename (abfd));
1312 h->type = ELF_ST_TYPE (sym.st_info);
1315 if (sym.st_other != 0
1316 && (definition || h->other == 0))
1317 h->other = sym.st_other;
1319 /* Set a flag in the hash table entry indicating the type of
1320 reference or definition we just found. Keep a count of
1321 the number of dynamic symbols we find. A dynamic symbol
1322 is one which is referenced or defined by both a regular
1323 object and a shared object. */
1324 old_flags = h->elf_link_hash_flags;
1325 dynsym = false;
1326 if (! dynamic)
1328 if (! definition)
1330 new_flag = ELF_LINK_HASH_REF_REGULAR;
1331 if (bind != STB_WEAK)
1332 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1334 else
1335 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1336 if (info->shared
1337 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1338 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1339 dynsym = true;
1341 else
1343 if (! definition)
1344 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1345 else
1346 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1347 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1348 | ELF_LINK_HASH_REF_REGULAR)) != 0
1349 || (h->weakdef != NULL
1350 && ! new_weakdef
1351 && h->weakdef->dynindx != -1))
1352 dynsym = true;
1355 h->elf_link_hash_flags |= new_flag;
1357 /* If this symbol has a version, and it is the default
1358 version, we create an indirect symbol from the default
1359 name to the fully decorated name. This will cause
1360 external references which do not specify a version to be
1361 bound to this version of the symbol. */
1362 if (definition)
1364 char *p;
1366 p = strchr (name, ELF_VER_CHR);
1367 if (p != NULL && p[1] == ELF_VER_CHR)
1369 char *shortname;
1370 struct elf_link_hash_entry *hi;
1371 boolean override;
1373 shortname = bfd_hash_allocate (&info->hash->table,
1374 p - name + 1);
1375 if (shortname == NULL)
1376 goto error_return;
1377 strncpy (shortname, name, p - name);
1378 shortname[p - name] = '\0';
1380 /* We are going to create a new symbol. Merge it
1381 with any existing symbol with this name. For the
1382 purposes of the merge, act as though we were
1383 defining the symbol we just defined, although we
1384 actually going to define an indirect symbol. */
1385 type_change_ok = false;
1386 size_change_ok = false;
1387 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1388 &value, &hi, &override,
1389 &type_change_ok, &size_change_ok))
1390 goto error_return;
1392 if (! override)
1394 if (! (_bfd_generic_link_add_one_symbol
1395 (info, abfd, shortname, BSF_INDIRECT,
1396 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1397 collect, (struct bfd_link_hash_entry **) &hi)))
1398 goto error_return;
1400 else
1402 /* In this case the symbol named SHORTNAME is
1403 overriding the indirect symbol we want to
1404 add. We were planning on making SHORTNAME an
1405 indirect symbol referring to NAME. SHORTNAME
1406 is the name without a version. NAME is the
1407 fully versioned name, and it is the default
1408 version.
1410 Overriding means that we already saw a
1411 definition for the symbol SHORTNAME in a
1412 regular object, and it is overriding the
1413 symbol defined in the dynamic object.
1415 When this happens, we actually want to change
1416 NAME, the symbol we just added, to refer to
1417 SHORTNAME. This will cause references to
1418 NAME in the shared object to become
1419 references to SHORTNAME in the regular
1420 object. This is what we expect when we
1421 override a function in a shared object: that
1422 the references in the shared object will be
1423 mapped to the definition in the regular
1424 object. */
1426 while (hi->root.type == bfd_link_hash_indirect
1427 || hi->root.type == bfd_link_hash_warning)
1428 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1430 h->root.type = bfd_link_hash_indirect;
1431 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1432 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1434 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1435 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1436 if (hi->elf_link_hash_flags
1437 & (ELF_LINK_HASH_REF_REGULAR
1438 | ELF_LINK_HASH_DEF_REGULAR))
1440 if (! _bfd_elf_link_record_dynamic_symbol (info,
1441 hi))
1442 goto error_return;
1446 /* Now set HI to H, so that the following code
1447 will set the other fields correctly. */
1448 hi = h;
1451 /* If there is a duplicate definition somewhere,
1452 then HI may not point to an indirect symbol. We
1453 will have reported an error to the user in that
1454 case. */
1456 if (hi->root.type == bfd_link_hash_indirect)
1458 struct elf_link_hash_entry *ht;
1460 /* If the symbol became indirect, then we assume
1461 that we have not seen a definition before. */
1462 BFD_ASSERT ((hi->elf_link_hash_flags
1463 & (ELF_LINK_HASH_DEF_DYNAMIC
1464 | ELF_LINK_HASH_DEF_REGULAR))
1465 == 0);
1467 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1469 /* Copy down any references that we may have
1470 already seen to the symbol which just became
1471 indirect. */
1472 ht->elf_link_hash_flags |=
1473 (hi->elf_link_hash_flags
1474 & (ELF_LINK_HASH_REF_DYNAMIC
1475 | ELF_LINK_HASH_REF_REGULAR
1476 | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
1478 /* Copy over the global and procedure linkage table
1479 offset entries. These may have been already set
1480 up by a check_relocs routine. */
1481 if (ht->got.offset == (bfd_vma) -1)
1483 ht->got.offset = hi->got.offset;
1484 hi->got.offset = (bfd_vma) -1;
1486 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1488 if (ht->plt.offset == (bfd_vma) -1)
1490 ht->plt.offset = hi->plt.offset;
1491 hi->plt.offset = (bfd_vma) -1;
1493 BFD_ASSERT (hi->plt.offset == (bfd_vma) -1);
1495 if (ht->dynindx == -1)
1497 ht->dynindx = hi->dynindx;
1498 ht->dynstr_index = hi->dynstr_index;
1499 hi->dynindx = -1;
1500 hi->dynstr_index = 0;
1502 BFD_ASSERT (hi->dynindx == -1);
1504 /* FIXME: There may be other information to copy
1505 over for particular targets. */
1507 /* See if the new flags lead us to realize that
1508 the symbol must be dynamic. */
1509 if (! dynsym)
1511 if (! dynamic)
1513 if (info->shared
1514 || ((hi->elf_link_hash_flags
1515 & ELF_LINK_HASH_REF_DYNAMIC)
1516 != 0))
1517 dynsym = true;
1519 else
1521 if ((hi->elf_link_hash_flags
1522 & ELF_LINK_HASH_REF_REGULAR) != 0)
1523 dynsym = true;
1528 /* We also need to define an indirection from the
1529 nondefault version of the symbol. */
1531 shortname = bfd_hash_allocate (&info->hash->table,
1532 strlen (name));
1533 if (shortname == NULL)
1534 goto error_return;
1535 strncpy (shortname, name, p - name);
1536 strcpy (shortname + (p - name), p + 1);
1538 /* Once again, merge with any existing symbol. */
1539 type_change_ok = false;
1540 size_change_ok = false;
1541 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1542 &value, &hi, &override,
1543 &type_change_ok, &size_change_ok))
1544 goto error_return;
1546 if (override)
1548 /* Here SHORTNAME is a versioned name, so we
1549 don't expect to see the type of override we
1550 do in the case above. */
1551 (*_bfd_error_handler)
1552 (_("%s: warning: unexpected redefinition of `%s'"),
1553 bfd_get_filename (abfd), shortname);
1555 else
1557 if (! (_bfd_generic_link_add_one_symbol
1558 (info, abfd, shortname, BSF_INDIRECT,
1559 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1560 collect, (struct bfd_link_hash_entry **) &hi)))
1561 goto error_return;
1563 /* If there is a duplicate definition somewhere,
1564 then HI may not point to an indirect symbol.
1565 We will have reported an error to the user in
1566 that case. */
1568 if (hi->root.type == bfd_link_hash_indirect)
1570 /* If the symbol became indirect, then we
1571 assume that we have not seen a definition
1572 before. */
1573 BFD_ASSERT ((hi->elf_link_hash_flags
1574 & (ELF_LINK_HASH_DEF_DYNAMIC
1575 | ELF_LINK_HASH_DEF_REGULAR))
1576 == 0);
1578 /* Copy down any references that we may have
1579 already seen to the symbol which just
1580 became indirect. */
1581 h->elf_link_hash_flags |=
1582 (hi->elf_link_hash_flags
1583 & (ELF_LINK_HASH_REF_DYNAMIC
1584 | ELF_LINK_HASH_REF_REGULAR
1585 | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
1587 /* Copy over the global and procedure linkage
1588 table offset entries. These may have been
1589 already set up by a check_relocs routine. */
1590 if (h->got.offset == (bfd_vma) -1)
1592 h->got.offset = hi->got.offset;
1593 hi->got.offset = (bfd_vma) -1;
1595 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1597 if (h->plt.offset == (bfd_vma) -1)
1599 h->plt.offset = hi->plt.offset;
1600 hi->plt.offset = (bfd_vma) -1;
1602 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1604 if (h->dynindx == -1)
1606 h->dynindx = hi->dynindx;
1607 h->dynstr_index = hi->dynstr_index;
1608 hi->dynindx = -1;
1609 hi->dynstr_index = 0;
1611 BFD_ASSERT (hi->dynindx == -1);
1613 /* FIXME: There may be other information to
1614 copy over for particular targets. */
1616 /* See if the new flags lead us to realize
1617 that the symbol must be dynamic. */
1618 if (! dynsym)
1620 if (! dynamic)
1622 if (info->shared
1623 || ((hi->elf_link_hash_flags
1624 & ELF_LINK_HASH_REF_DYNAMIC)
1625 != 0))
1626 dynsym = true;
1628 else
1630 if ((hi->elf_link_hash_flags
1631 & ELF_LINK_HASH_REF_REGULAR) != 0)
1632 dynsym = true;
1640 if (dynsym && h->dynindx == -1)
1642 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1643 goto error_return;
1644 if (h->weakdef != NULL
1645 && ! new_weakdef
1646 && h->weakdef->dynindx == -1)
1648 if (! _bfd_elf_link_record_dynamic_symbol (info,
1649 h->weakdef))
1650 goto error_return;
1656 /* Now set the weakdefs field correctly for all the weak defined
1657 symbols we found. The only way to do this is to search all the
1658 symbols. Since we only need the information for non functions in
1659 dynamic objects, that's the only time we actually put anything on
1660 the list WEAKS. We need this information so that if a regular
1661 object refers to a symbol defined weakly in a dynamic object, the
1662 real symbol in the dynamic object is also put in the dynamic
1663 symbols; we also must arrange for both symbols to point to the
1664 same memory location. We could handle the general case of symbol
1665 aliasing, but a general symbol alias can only be generated in
1666 assembler code, handling it correctly would be very time
1667 consuming, and other ELF linkers don't handle general aliasing
1668 either. */
1669 while (weaks != NULL)
1671 struct elf_link_hash_entry *hlook;
1672 asection *slook;
1673 bfd_vma vlook;
1674 struct elf_link_hash_entry **hpp;
1675 struct elf_link_hash_entry **hppend;
1677 hlook = weaks;
1678 weaks = hlook->weakdef;
1679 hlook->weakdef = NULL;
1681 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
1682 || hlook->root.type == bfd_link_hash_defweak
1683 || hlook->root.type == bfd_link_hash_common
1684 || hlook->root.type == bfd_link_hash_indirect);
1685 slook = hlook->root.u.def.section;
1686 vlook = hlook->root.u.def.value;
1688 hpp = elf_sym_hashes (abfd);
1689 hppend = hpp + extsymcount;
1690 for (; hpp < hppend; hpp++)
1692 struct elf_link_hash_entry *h;
1694 h = *hpp;
1695 if (h != NULL && h != hlook
1696 && h->root.type == bfd_link_hash_defined
1697 && h->root.u.def.section == slook
1698 && h->root.u.def.value == vlook)
1700 hlook->weakdef = h;
1702 /* If the weak definition is in the list of dynamic
1703 symbols, make sure the real definition is put there
1704 as well. */
1705 if (hlook->dynindx != -1
1706 && h->dynindx == -1)
1708 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1709 goto error_return;
1712 /* If the real definition is in the list of dynamic
1713 symbols, make sure the weak definition is put there
1714 as well. If we don't do this, then the dynamic
1715 loader might not merge the entries for the real
1716 definition and the weak definition. */
1717 if (h->dynindx != -1
1718 && hlook->dynindx == -1)
1720 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
1721 goto error_return;
1724 break;
1729 if (buf != NULL)
1731 free (buf);
1732 buf = NULL;
1735 if (extversym != NULL)
1737 free (extversym);
1738 extversym = NULL;
1741 /* If this object is the same format as the output object, and it is
1742 not a shared library, then let the backend look through the
1743 relocs.
1745 This is required to build global offset table entries and to
1746 arrange for dynamic relocs. It is not required for the
1747 particular common case of linking non PIC code, even when linking
1748 against shared libraries, but unfortunately there is no way of
1749 knowing whether an object file has been compiled PIC or not.
1750 Looking through the relocs is not particularly time consuming.
1751 The problem is that we must either (1) keep the relocs in memory,
1752 which causes the linker to require additional runtime memory or
1753 (2) read the relocs twice from the input file, which wastes time.
1754 This would be a good case for using mmap.
1756 I have no idea how to handle linking PIC code into a file of a
1757 different format. It probably can't be done. */
1758 check_relocs = get_elf_backend_data (abfd)->check_relocs;
1759 if (! dynamic
1760 && abfd->xvec == info->hash->creator
1761 && check_relocs != NULL)
1763 asection *o;
1765 for (o = abfd->sections; o != NULL; o = o->next)
1767 Elf_Internal_Rela *internal_relocs;
1768 boolean ok;
1770 if ((o->flags & SEC_RELOC) == 0
1771 || o->reloc_count == 0
1772 || ((info->strip == strip_all || info->strip == strip_debugger)
1773 && (o->flags & SEC_DEBUGGING) != 0)
1774 || bfd_is_abs_section (o->output_section))
1775 continue;
1777 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
1778 (abfd, o, (PTR) NULL,
1779 (Elf_Internal_Rela *) NULL,
1780 info->keep_memory));
1781 if (internal_relocs == NULL)
1782 goto error_return;
1784 ok = (*check_relocs) (abfd, info, o, internal_relocs);
1786 if (! info->keep_memory)
1787 free (internal_relocs);
1789 if (! ok)
1790 goto error_return;
1794 /* If this is a non-traditional, non-relocateable link, try to
1795 optimize the handling of the .stab/.stabstr sections. */
1796 if (! dynamic
1797 && ! info->relocateable
1798 && ! info->traditional_format
1799 && info->hash->creator->flavour == bfd_target_elf_flavour
1800 && (info->strip != strip_all && info->strip != strip_debugger))
1802 asection *stab, *stabstr;
1804 stab = bfd_get_section_by_name (abfd, ".stab");
1805 if (stab != NULL)
1807 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
1809 if (stabstr != NULL)
1811 struct bfd_elf_section_data *secdata;
1813 secdata = elf_section_data (stab);
1814 if (! _bfd_link_section_stabs (abfd,
1815 &elf_hash_table (info)->stab_info,
1816 stab, stabstr,
1817 &secdata->stab_info))
1818 goto error_return;
1823 return true;
1825 error_return:
1826 if (buf != NULL)
1827 free (buf);
1828 if (dynbuf != NULL)
1829 free (dynbuf);
1830 if (dynver != NULL)
1831 free (dynver);
1832 if (extversym != NULL)
1833 free (extversym);
1834 return false;
1837 /* Create some sections which will be filled in with dynamic linking
1838 information. ABFD is an input file which requires dynamic sections
1839 to be created. The dynamic sections take up virtual memory space
1840 when the final executable is run, so we need to create them before
1841 addresses are assigned to the output sections. We work out the
1842 actual contents and size of these sections later. */
1844 boolean
1845 elf_link_create_dynamic_sections (abfd, info)
1846 bfd *abfd;
1847 struct bfd_link_info *info;
1849 flagword flags;
1850 register asection *s;
1851 struct elf_link_hash_entry *h;
1852 struct elf_backend_data *bed;
1854 if (elf_hash_table (info)->dynamic_sections_created)
1855 return true;
1857 /* Make sure that all dynamic sections use the same input BFD. */
1858 if (elf_hash_table (info)->dynobj == NULL)
1859 elf_hash_table (info)->dynobj = abfd;
1860 else
1861 abfd = elf_hash_table (info)->dynobj;
1863 /* Note that we set the SEC_IN_MEMORY flag for all of these
1864 sections. */
1865 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
1866 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
1868 /* A dynamically linked executable has a .interp section, but a
1869 shared library does not. */
1870 if (! info->shared)
1872 s = bfd_make_section (abfd, ".interp");
1873 if (s == NULL
1874 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
1875 return false;
1878 /* Create sections to hold version informations. These are removed
1879 if they are not needed. */
1880 s = bfd_make_section (abfd, ".gnu.version_d");
1881 if (s == NULL
1882 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1883 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1884 return false;
1886 s = bfd_make_section (abfd, ".gnu.version");
1887 if (s == NULL
1888 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1889 || ! bfd_set_section_alignment (abfd, s, 1))
1890 return false;
1892 s = bfd_make_section (abfd, ".gnu.version_r");
1893 if (s == NULL
1894 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1895 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1896 return false;
1898 s = bfd_make_section (abfd, ".dynsym");
1899 if (s == NULL
1900 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1901 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1902 return false;
1904 s = bfd_make_section (abfd, ".dynstr");
1905 if (s == NULL
1906 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
1907 return false;
1909 /* Create a strtab to hold the dynamic symbol names. */
1910 if (elf_hash_table (info)->dynstr == NULL)
1912 elf_hash_table (info)->dynstr = elf_stringtab_init ();
1913 if (elf_hash_table (info)->dynstr == NULL)
1914 return false;
1917 s = bfd_make_section (abfd, ".dynamic");
1918 if (s == NULL
1919 || ! bfd_set_section_flags (abfd, s, flags)
1920 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1921 return false;
1923 /* The special symbol _DYNAMIC is always set to the start of the
1924 .dynamic section. This call occurs before we have processed the
1925 symbols for any dynamic object, so we don't have to worry about
1926 overriding a dynamic definition. We could set _DYNAMIC in a
1927 linker script, but we only want to define it if we are, in fact,
1928 creating a .dynamic section. We don't want to define it if there
1929 is no .dynamic section, since on some ELF platforms the start up
1930 code examines it to decide how to initialize the process. */
1931 h = NULL;
1932 if (! (_bfd_generic_link_add_one_symbol
1933 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
1934 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
1935 (struct bfd_link_hash_entry **) &h)))
1936 return false;
1937 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
1938 h->type = STT_OBJECT;
1940 if (info->shared
1941 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
1942 return false;
1944 s = bfd_make_section (abfd, ".hash");
1945 if (s == NULL
1946 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
1947 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
1948 return false;
1950 /* Let the backend create the rest of the sections. This lets the
1951 backend set the right flags. The backend will normally create
1952 the .got and .plt sections. */
1953 bed = get_elf_backend_data (abfd);
1954 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
1955 return false;
1957 elf_hash_table (info)->dynamic_sections_created = true;
1959 return true;
1962 /* Add an entry to the .dynamic table. */
1964 boolean
1965 elf_add_dynamic_entry (info, tag, val)
1966 struct bfd_link_info *info;
1967 bfd_vma tag;
1968 bfd_vma val;
1970 Elf_Internal_Dyn dyn;
1971 bfd *dynobj;
1972 asection *s;
1973 size_t newsize;
1974 bfd_byte *newcontents;
1976 dynobj = elf_hash_table (info)->dynobj;
1978 s = bfd_get_section_by_name (dynobj, ".dynamic");
1979 BFD_ASSERT (s != NULL);
1981 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
1982 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
1983 if (newcontents == NULL)
1984 return false;
1986 dyn.d_tag = tag;
1987 dyn.d_un.d_val = val;
1988 elf_swap_dyn_out (dynobj, &dyn,
1989 (Elf_External_Dyn *) (newcontents + s->_raw_size));
1991 s->_raw_size = newsize;
1992 s->contents = newcontents;
1994 return true;
1998 /* Read and swap the relocs from the section indicated by SHDR. This
1999 may be either a REL or a RELA section. The relocations are
2000 translated into RELA relocations and stored in INTERNAL_RELOCS,
2001 which should have already been allocated to contain enough space.
2002 The EXTERNAL_RELOCS are a buffer where the external form of the
2003 relocations should be stored.
2005 Returns false if something goes wrong. */
2007 static boolean
2008 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2009 internal_relocs)
2010 bfd *abfd;
2011 Elf_Internal_Shdr *shdr;
2012 PTR external_relocs;
2013 Elf_Internal_Rela *internal_relocs;
2015 /* If there aren't any relocations, that's OK. */
2016 if (!shdr)
2017 return true;
2019 /* Position ourselves at the start of the section. */
2020 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2021 return false;
2023 /* Read the relocations. */
2024 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2025 != shdr->sh_size)
2026 return false;
2028 /* Convert the external relocations to the internal format. */
2029 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2031 Elf_External_Rel *erel;
2032 Elf_External_Rel *erelend;
2033 Elf_Internal_Rela *irela;
2035 erel = (Elf_External_Rel *) external_relocs;
2036 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2037 irela = internal_relocs;
2038 for (; erel < erelend; erel++, irela++)
2040 Elf_Internal_Rel irel;
2042 elf_swap_reloc_in (abfd, erel, &irel);
2043 irela->r_offset = irel.r_offset;
2044 irela->r_info = irel.r_info;
2045 irela->r_addend = 0;
2048 else
2050 Elf_External_Rela *erela;
2051 Elf_External_Rela *erelaend;
2052 Elf_Internal_Rela *irela;
2054 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2056 erela = (Elf_External_Rela *) external_relocs;
2057 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2058 irela = internal_relocs;
2059 for (; erela < erelaend; erela++, irela++)
2060 elf_swap_reloca_in (abfd, erela, irela);
2063 return true;
2066 /* Read and swap the relocs for a section. They may have been cached.
2067 If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL,
2068 they are used as buffers to read into. They are known to be large
2069 enough. If the INTERNAL_RELOCS relocs argument is NULL, the return
2070 value is allocated using either malloc or bfd_alloc, according to
2071 the KEEP_MEMORY argument. */
2073 Elf_Internal_Rela *
2074 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2075 keep_memory)
2076 bfd *abfd;
2077 asection *o;
2078 PTR external_relocs;
2079 Elf_Internal_Rela *internal_relocs;
2080 boolean keep_memory;
2082 Elf_Internal_Shdr *rel_hdr;
2083 PTR alloc1 = NULL;
2084 Elf_Internal_Rela *alloc2 = NULL;
2086 if (elf_section_data (o)->relocs != NULL)
2087 return elf_section_data (o)->relocs;
2089 if (o->reloc_count == 0)
2090 return NULL;
2092 rel_hdr = &elf_section_data (o)->rel_hdr;
2094 if (internal_relocs == NULL)
2096 size_t size;
2098 size = o->reloc_count * sizeof (Elf_Internal_Rela);
2099 if (keep_memory)
2100 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2101 else
2102 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2103 if (internal_relocs == NULL)
2104 goto error_return;
2107 if (external_relocs == NULL)
2109 size_t size = (size_t) rel_hdr->sh_size;
2111 if (elf_section_data (o)->rel_hdr2)
2112 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2113 alloc1 = (PTR) bfd_malloc (size);
2114 if (alloc1 == NULL)
2115 goto error_return;
2116 external_relocs = alloc1;
2119 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2120 external_relocs,
2121 internal_relocs))
2122 goto error_return;
2123 if (!elf_link_read_relocs_from_section
2124 (abfd,
2125 elf_section_data (o)->rel_hdr2,
2126 external_relocs + rel_hdr->sh_size,
2127 internal_relocs + rel_hdr->sh_size / rel_hdr->sh_entsize))
2128 goto error_return;
2130 /* Cache the results for next time, if we can. */
2131 if (keep_memory)
2132 elf_section_data (o)->relocs = internal_relocs;
2134 if (alloc1 != NULL)
2135 free (alloc1);
2137 /* Don't free alloc2, since if it was allocated we are passing it
2138 back (under the name of internal_relocs). */
2140 return internal_relocs;
2142 error_return:
2143 if (alloc1 != NULL)
2144 free (alloc1);
2145 if (alloc2 != NULL)
2146 free (alloc2);
2147 return NULL;
2151 /* Record an assignment to a symbol made by a linker script. We need
2152 this in case some dynamic object refers to this symbol. */
2154 /*ARGSUSED*/
2155 boolean
2156 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2157 bfd *output_bfd;
2158 struct bfd_link_info *info;
2159 const char *name;
2160 boolean provide;
2162 struct elf_link_hash_entry *h;
2164 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2165 return true;
2167 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2168 if (h == NULL)
2169 return false;
2171 if (h->root.type == bfd_link_hash_new)
2172 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2174 /* If this symbol is being provided by the linker script, and it is
2175 currently defined by a dynamic object, but not by a regular
2176 object, then mark it as undefined so that the generic linker will
2177 force the correct value. */
2178 if (provide
2179 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2180 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2181 h->root.type = bfd_link_hash_undefined;
2183 /* If this symbol is not being provided by the linker script, and it is
2184 currently defined by a dynamic object, but not by a regular object,
2185 then clear out any version information because the symbol will not be
2186 associated with the dynamic object any more. */
2187 if (!provide
2188 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2189 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2190 h->verinfo.verdef = NULL;
2192 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2193 h->type = STT_OBJECT;
2195 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2196 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2197 || info->shared)
2198 && h->dynindx == -1)
2200 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2201 return false;
2203 /* If this is a weak defined symbol, and we know a corresponding
2204 real symbol from the same dynamic object, make sure the real
2205 symbol is also made into a dynamic symbol. */
2206 if (h->weakdef != NULL
2207 && h->weakdef->dynindx == -1)
2209 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2210 return false;
2214 return true;
2217 /* This structure is used to pass information to
2218 elf_link_assign_sym_version. */
2220 struct elf_assign_sym_version_info
2222 /* Output BFD. */
2223 bfd *output_bfd;
2224 /* General link information. */
2225 struct bfd_link_info *info;
2226 /* Version tree. */
2227 struct bfd_elf_version_tree *verdefs;
2228 /* Whether we are exporting all dynamic symbols. */
2229 boolean export_dynamic;
2230 /* Whether we removed any symbols from the dynamic symbol table. */
2231 boolean removed_dynamic;
2232 /* Whether we had a failure. */
2233 boolean failed;
2236 /* This structure is used to pass information to
2237 elf_link_find_version_dependencies. */
2239 struct elf_find_verdep_info
2241 /* Output BFD. */
2242 bfd *output_bfd;
2243 /* General link information. */
2244 struct bfd_link_info *info;
2245 /* The number of dependencies. */
2246 unsigned int vers;
2247 /* Whether we had a failure. */
2248 boolean failed;
2251 /* Array used to determine the number of hash table buckets to use
2252 based on the number of symbols there are. If there are fewer than
2253 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2254 fewer than 37 we use 17 buckets, and so forth. We never use more
2255 than 32771 buckets. */
2257 static const size_t elf_buckets[] =
2259 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2260 16411, 32771, 0
2263 /* Compute bucket count for hashing table. We do not use a static set
2264 of possible tables sizes anymore. Instead we determine for all
2265 possible reasonable sizes of the table the outcome (i.e., the
2266 number of collisions etc) and choose the best solution. The
2267 weighting functions are not too simple to allow the table to grow
2268 without bounds. Instead one of the weighting factors is the size.
2269 Therefore the result is always a good payoff between few collisions
2270 (= short chain lengths) and table size. */
2271 static size_t
2272 compute_bucket_count (info)
2273 struct bfd_link_info *info;
2275 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2276 size_t best_size;
2277 unsigned long int *hashcodes;
2278 unsigned long int *hashcodesp;
2279 unsigned long int i;
2281 /* Compute the hash values for all exported symbols. At the same
2282 time store the values in an array so that we could use them for
2283 optimizations. */
2284 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2285 * sizeof (unsigned long int));
2286 if (hashcodes == NULL)
2287 return 0;
2288 hashcodesp = hashcodes;
2290 /* Put all hash values in HASHCODES. */
2291 elf_link_hash_traverse (elf_hash_table (info),
2292 elf_collect_hash_codes, &hashcodesp);
2294 /* We have a problem here. The following code to optimize the table
2295 size requires an integer type with more the 32 bits. If
2296 BFD_HOST_U_64_BIT is set we know about such a type. */
2297 #ifdef BFD_HOST_U_64_BIT
2298 if (info->optimize == true)
2300 unsigned long int nsyms = hashcodesp - hashcodes;
2301 size_t minsize;
2302 size_t maxsize;
2303 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2304 unsigned long int *counts ;
2306 /* Possible optimization parameters: if we have NSYMS symbols we say
2307 that the hashing table must at least have NSYMS/4 and at most
2308 2*NSYMS buckets. */
2309 minsize = nsyms / 4;
2310 if (minsize == 0)
2311 minsize = 1;
2312 best_size = maxsize = nsyms * 2;
2314 /* Create array where we count the collisions in. We must use bfd_malloc
2315 since the size could be large. */
2316 counts = (unsigned long int *) bfd_malloc (maxsize
2317 * sizeof (unsigned long int));
2318 if (counts == NULL)
2320 free (hashcodes);
2321 return 0;
2324 /* Compute the "optimal" size for the hash table. The criteria is a
2325 minimal chain length. The minor criteria is (of course) the size
2326 of the table. */
2327 for (i = minsize; i < maxsize; ++i)
2329 /* Walk through the array of hashcodes and count the collisions. */
2330 BFD_HOST_U_64_BIT max;
2331 unsigned long int j;
2332 unsigned long int fact;
2334 memset (counts, '\0', i * sizeof (unsigned long int));
2336 /* Determine how often each hash bucket is used. */
2337 for (j = 0; j < nsyms; ++j)
2338 ++counts[hashcodes[j] % i];
2340 /* For the weight function we need some information about the
2341 pagesize on the target. This is information need not be 100%
2342 accurate. Since this information is not available (so far) we
2343 define it here to a reasonable default value. If it is crucial
2344 to have a better value some day simply define this value. */
2345 # ifndef BFD_TARGET_PAGESIZE
2346 # define BFD_TARGET_PAGESIZE (4096)
2347 # endif
2349 /* We in any case need 2 + NSYMS entries for the size values and
2350 the chains. */
2351 max = (2 + nsyms) * (ARCH_SIZE / 8);
2353 # if 1
2354 /* Variant 1: optimize for short chains. We add the squares
2355 of all the chain lengths (which favous many small chain
2356 over a few long chains). */
2357 for (j = 0; j < i; ++j)
2358 max += counts[j] * counts[j];
2360 /* This adds penalties for the overall size of the table. */
2361 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2362 max *= fact * fact;
2363 # else
2364 /* Variant 2: Optimize a lot more for small table. Here we
2365 also add squares of the size but we also add penalties for
2366 empty slots (the +1 term). */
2367 for (j = 0; j < i; ++j)
2368 max += (1 + counts[j]) * (1 + counts[j]);
2370 /* The overall size of the table is considered, but not as
2371 strong as in variant 1, where it is squared. */
2372 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2373 max *= fact;
2374 # endif
2376 /* Compare with current best results. */
2377 if (max < best_chlen)
2379 best_chlen = max;
2380 best_size = i;
2384 free (counts);
2386 else
2387 #endif /* defined (BFD_HOST_U_64_BIT) */
2389 /* This is the fallback solution if no 64bit type is available or if we
2390 are not supposed to spend much time on optimizations. We select the
2391 bucket count using a fixed set of numbers. */
2392 for (i = 0; elf_buckets[i] != 0; i++)
2394 best_size = elf_buckets[i];
2395 if (dynsymcount < elf_buckets[i + 1])
2396 break;
2400 /* Free the arrays we needed. */
2401 free (hashcodes);
2403 return best_size;
2406 /* Remove SECTION from the BFD. If a symbol for SECTION was going to
2407 be put into the dynamic symbol table, remove it, and renumber
2408 subsequent entries. */
2410 static void
2411 elf_link_remove_section_and_adjust_dynindices (abfd, info, section)
2412 bfd *abfd;
2413 struct bfd_link_info *info;
2414 asection *section;
2416 asection **spp;
2418 /* Remove the section from the output list. */
2419 for (spp = &abfd->sections;
2420 *spp != section->output_section;
2421 spp = &(*spp)->next)
2423 *spp = section->output_section->next;
2424 --abfd->section_count;
2426 if (elf_section_data (section->output_section)->dynindx)
2428 asection *s;
2429 int increment = -1;
2431 /* We were going to output an entry in the dynamic symbol table
2432 for the symbol corresponding to this section. Now, the
2433 section is gone. So, we must renumber the dynamic indices of
2434 all subsequent sections and all other entries in the dynamic
2435 symbol table. */
2436 elf_section_data (section->output_section)->dynindx = 0;
2437 for (s = section->output_section->next; s; s = s->next)
2438 if (elf_section_data (s)->dynindx)
2439 --elf_section_data (s)->dynindx;
2441 elf_link_hash_traverse (elf_hash_table (info),
2442 _bfd_elf_link_adjust_dynindx,
2443 &increment);
2445 /* There is one less dynamic symbol than there was before. */
2446 --elf_hash_table (info)->dynsymcount;
2450 /* Set up the sizes and contents of the ELF dynamic sections. This is
2451 called by the ELF linker emulation before_allocation routine. We
2452 must set the sizes of the sections before the linker sets the
2453 addresses of the various sections. */
2455 boolean
2456 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2457 export_dynamic, filter_shlib,
2458 auxiliary_filters, info, sinterpptr,
2459 verdefs)
2460 bfd *output_bfd;
2461 const char *soname;
2462 const char *rpath;
2463 boolean export_dynamic;
2464 const char *filter_shlib;
2465 const char * const *auxiliary_filters;
2466 struct bfd_link_info *info;
2467 asection **sinterpptr;
2468 struct bfd_elf_version_tree *verdefs;
2470 bfd_size_type soname_indx;
2471 bfd *dynobj;
2472 struct elf_backend_data *bed;
2473 bfd_size_type old_dynsymcount;
2474 struct elf_assign_sym_version_info asvinfo;
2476 *sinterpptr = NULL;
2478 soname_indx = (bfd_size_type) -1;
2480 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2481 return true;
2483 /* The backend may have to create some sections regardless of whether
2484 we're dynamic or not. */
2485 bed = get_elf_backend_data (output_bfd);
2486 if (bed->elf_backend_always_size_sections
2487 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2488 return false;
2490 dynobj = elf_hash_table (info)->dynobj;
2492 /* If there were no dynamic objects in the link, there is nothing to
2493 do here. */
2494 if (dynobj == NULL)
2495 return true;
2497 /* If we are supposed to export all symbols into the dynamic symbol
2498 table (this is not the normal case), then do so. */
2499 if (export_dynamic)
2501 struct elf_info_failed eif;
2503 eif.failed = false;
2504 eif.info = info;
2505 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2506 (PTR) &eif);
2507 if (eif.failed)
2508 return false;
2511 if (elf_hash_table (info)->dynamic_sections_created)
2513 struct elf_info_failed eif;
2514 struct elf_link_hash_entry *h;
2515 bfd_size_type strsize;
2517 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2518 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2520 if (soname != NULL)
2522 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2523 soname, true, true);
2524 if (soname_indx == (bfd_size_type) -1
2525 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2526 return false;
2529 if (info->symbolic)
2531 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2532 return false;
2535 if (rpath != NULL)
2537 bfd_size_type indx;
2539 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2540 true, true);
2541 if (indx == (bfd_size_type) -1
2542 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
2543 return false;
2546 if (filter_shlib != NULL)
2548 bfd_size_type indx;
2550 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2551 filter_shlib, true, true);
2552 if (indx == (bfd_size_type) -1
2553 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2554 return false;
2557 if (auxiliary_filters != NULL)
2559 const char * const *p;
2561 for (p = auxiliary_filters; *p != NULL; p++)
2563 bfd_size_type indx;
2565 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2566 *p, true, true);
2567 if (indx == (bfd_size_type) -1
2568 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2569 return false;
2573 /* Attach all the symbols to their version information. */
2574 asvinfo.output_bfd = output_bfd;
2575 asvinfo.info = info;
2576 asvinfo.verdefs = verdefs;
2577 asvinfo.export_dynamic = export_dynamic;
2578 asvinfo.removed_dynamic = false;
2579 asvinfo.failed = false;
2581 elf_link_hash_traverse (elf_hash_table (info),
2582 elf_link_assign_sym_version,
2583 (PTR) &asvinfo);
2584 if (asvinfo.failed)
2585 return false;
2587 /* Find all symbols which were defined in a dynamic object and make
2588 the backend pick a reasonable value for them. */
2589 eif.failed = false;
2590 eif.info = info;
2591 elf_link_hash_traverse (elf_hash_table (info),
2592 elf_adjust_dynamic_symbol,
2593 (PTR) &eif);
2594 if (eif.failed)
2595 return false;
2597 /* Add some entries to the .dynamic section. We fill in some of the
2598 values later, in elf_bfd_final_link, but we must add the entries
2599 now so that we know the final size of the .dynamic section. */
2600 h = elf_link_hash_lookup (elf_hash_table (info), "_init", false,
2601 false, false);
2602 if (h != NULL
2603 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2604 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2606 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2607 return false;
2609 h = elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
2610 false, false);
2611 if (h != NULL
2612 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2613 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2615 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2616 return false;
2618 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2619 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2620 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2621 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2622 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2623 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2624 sizeof (Elf_External_Sym)))
2625 return false;
2628 /* The backend must work out the sizes of all the other dynamic
2629 sections. */
2630 old_dynsymcount = elf_hash_table (info)->dynsymcount;
2631 if (bed->elf_backend_size_dynamic_sections
2632 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2633 return false;
2635 if (elf_hash_table (info)->dynamic_sections_created)
2637 size_t dynsymcount;
2638 asection *s;
2639 size_t bucketcount = 0;
2640 Elf_Internal_Sym isym;
2642 /* Set up the version definition section. */
2643 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2644 BFD_ASSERT (s != NULL);
2646 /* We may have created additional version definitions if we are
2647 just linking a regular application. */
2648 verdefs = asvinfo.verdefs;
2650 if (verdefs == NULL)
2651 elf_link_remove_section_and_adjust_dynindices (output_bfd,
2652 info,
2654 else
2656 unsigned int cdefs;
2657 bfd_size_type size;
2658 struct bfd_elf_version_tree *t;
2659 bfd_byte *p;
2660 Elf_Internal_Verdef def;
2661 Elf_Internal_Verdaux defaux;
2663 if (asvinfo.removed_dynamic)
2665 /* Some dynamic symbols were changed to be local
2666 symbols. In this case, we renumber all of the
2667 dynamic symbols, so that we don't have a hole. If
2668 the backend changed dynsymcount, then assume that the
2669 new symbols are at the start. This is the case on
2670 the MIPS. FIXME: The names of the removed symbols
2671 will still be in the dynamic string table, wasting
2672 space. */
2673 elf_hash_table (info)->dynsymcount =
2674 1 + (elf_hash_table (info)->dynsymcount - old_dynsymcount);
2675 elf_link_hash_traverse (elf_hash_table (info),
2676 elf_link_renumber_dynsyms,
2677 (PTR) info);
2680 cdefs = 0;
2681 size = 0;
2683 /* Make space for the base version. */
2684 size += sizeof (Elf_External_Verdef);
2685 size += sizeof (Elf_External_Verdaux);
2686 ++cdefs;
2688 for (t = verdefs; t != NULL; t = t->next)
2690 struct bfd_elf_version_deps *n;
2692 size += sizeof (Elf_External_Verdef);
2693 size += sizeof (Elf_External_Verdaux);
2694 ++cdefs;
2696 for (n = t->deps; n != NULL; n = n->next)
2697 size += sizeof (Elf_External_Verdaux);
2700 s->_raw_size = size;
2701 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2702 if (s->contents == NULL && s->_raw_size != 0)
2703 return false;
2705 /* Fill in the version definition section. */
2707 p = s->contents;
2709 def.vd_version = VER_DEF_CURRENT;
2710 def.vd_flags = VER_FLG_BASE;
2711 def.vd_ndx = 1;
2712 def.vd_cnt = 1;
2713 def.vd_aux = sizeof (Elf_External_Verdef);
2714 def.vd_next = (sizeof (Elf_External_Verdef)
2715 + sizeof (Elf_External_Verdaux));
2717 if (soname_indx != (bfd_size_type) -1)
2719 def.vd_hash = bfd_elf_hash ((const unsigned char *) soname);
2720 defaux.vda_name = soname_indx;
2722 else
2724 const char *name;
2725 bfd_size_type indx;
2727 name = output_bfd->filename;
2728 def.vd_hash = bfd_elf_hash ((const unsigned char *) name);
2729 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2730 name, true, false);
2731 if (indx == (bfd_size_type) -1)
2732 return false;
2733 defaux.vda_name = indx;
2735 defaux.vda_next = 0;
2737 _bfd_elf_swap_verdef_out (output_bfd, &def,
2738 (Elf_External_Verdef *)p);
2739 p += sizeof (Elf_External_Verdef);
2740 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2741 (Elf_External_Verdaux *) p);
2742 p += sizeof (Elf_External_Verdaux);
2744 for (t = verdefs; t != NULL; t = t->next)
2746 unsigned int cdeps;
2747 struct bfd_elf_version_deps *n;
2748 struct elf_link_hash_entry *h;
2750 cdeps = 0;
2751 for (n = t->deps; n != NULL; n = n->next)
2752 ++cdeps;
2754 /* Add a symbol representing this version. */
2755 h = NULL;
2756 if (! (_bfd_generic_link_add_one_symbol
2757 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
2758 (bfd_vma) 0, (const char *) NULL, false,
2759 get_elf_backend_data (dynobj)->collect,
2760 (struct bfd_link_hash_entry **) &h)))
2761 return false;
2762 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
2763 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2764 h->type = STT_OBJECT;
2765 h->verinfo.vertree = t;
2767 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2768 return false;
2770 def.vd_version = VER_DEF_CURRENT;
2771 def.vd_flags = 0;
2772 if (t->globals == NULL && t->locals == NULL && ! t->used)
2773 def.vd_flags |= VER_FLG_WEAK;
2774 def.vd_ndx = t->vernum + 1;
2775 def.vd_cnt = cdeps + 1;
2776 def.vd_hash = bfd_elf_hash ((const unsigned char *) t->name);
2777 def.vd_aux = sizeof (Elf_External_Verdef);
2778 if (t->next != NULL)
2779 def.vd_next = (sizeof (Elf_External_Verdef)
2780 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
2781 else
2782 def.vd_next = 0;
2784 _bfd_elf_swap_verdef_out (output_bfd, &def,
2785 (Elf_External_Verdef *) p);
2786 p += sizeof (Elf_External_Verdef);
2788 defaux.vda_name = h->dynstr_index;
2789 if (t->deps == NULL)
2790 defaux.vda_next = 0;
2791 else
2792 defaux.vda_next = sizeof (Elf_External_Verdaux);
2793 t->name_indx = defaux.vda_name;
2795 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2796 (Elf_External_Verdaux *) p);
2797 p += sizeof (Elf_External_Verdaux);
2799 for (n = t->deps; n != NULL; n = n->next)
2801 if (n->version_needed == NULL)
2803 /* This can happen if there was an error in the
2804 version script. */
2805 defaux.vda_name = 0;
2807 else
2808 defaux.vda_name = n->version_needed->name_indx;
2809 if (n->next == NULL)
2810 defaux.vda_next = 0;
2811 else
2812 defaux.vda_next = sizeof (Elf_External_Verdaux);
2814 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
2815 (Elf_External_Verdaux *) p);
2816 p += sizeof (Elf_External_Verdaux);
2820 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
2821 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
2822 return false;
2824 elf_tdata (output_bfd)->cverdefs = cdefs;
2827 /* Work out the size of the version reference section. */
2829 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
2830 BFD_ASSERT (s != NULL);
2832 struct elf_find_verdep_info sinfo;
2834 sinfo.output_bfd = output_bfd;
2835 sinfo.info = info;
2836 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
2837 if (sinfo.vers == 0)
2838 sinfo.vers = 1;
2839 sinfo.failed = false;
2841 elf_link_hash_traverse (elf_hash_table (info),
2842 elf_link_find_version_dependencies,
2843 (PTR) &sinfo);
2845 if (elf_tdata (output_bfd)->verref == NULL)
2846 elf_link_remove_section_and_adjust_dynindices (output_bfd,
2847 info,
2849 else
2851 Elf_Internal_Verneed *t;
2852 unsigned int size;
2853 unsigned int crefs;
2854 bfd_byte *p;
2856 /* Build the version definition section. */
2857 size = 0;
2858 crefs = 0;
2859 for (t = elf_tdata (output_bfd)->verref;
2860 t != NULL;
2861 t = t->vn_nextref)
2863 Elf_Internal_Vernaux *a;
2865 size += sizeof (Elf_External_Verneed);
2866 ++crefs;
2867 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2868 size += sizeof (Elf_External_Vernaux);
2871 s->_raw_size = size;
2872 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
2873 if (s->contents == NULL)
2874 return false;
2876 p = s->contents;
2877 for (t = elf_tdata (output_bfd)->verref;
2878 t != NULL;
2879 t = t->vn_nextref)
2881 unsigned int caux;
2882 Elf_Internal_Vernaux *a;
2883 bfd_size_type indx;
2885 caux = 0;
2886 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2887 ++caux;
2889 t->vn_version = VER_NEED_CURRENT;
2890 t->vn_cnt = caux;
2891 if (elf_dt_name (t->vn_bfd) != NULL)
2892 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2893 elf_dt_name (t->vn_bfd),
2894 true, false);
2895 else
2896 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2897 t->vn_bfd->filename, true, false);
2898 if (indx == (bfd_size_type) -1)
2899 return false;
2900 t->vn_file = indx;
2901 t->vn_aux = sizeof (Elf_External_Verneed);
2902 if (t->vn_nextref == NULL)
2903 t->vn_next = 0;
2904 else
2905 t->vn_next = (sizeof (Elf_External_Verneed)
2906 + caux * sizeof (Elf_External_Vernaux));
2908 _bfd_elf_swap_verneed_out (output_bfd, t,
2909 (Elf_External_Verneed *) p);
2910 p += sizeof (Elf_External_Verneed);
2912 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
2914 a->vna_hash = bfd_elf_hash ((const unsigned char *)
2915 a->vna_nodename);
2916 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2917 a->vna_nodename, true, false);
2918 if (indx == (bfd_size_type) -1)
2919 return false;
2920 a->vna_name = indx;
2921 if (a->vna_nextptr == NULL)
2922 a->vna_next = 0;
2923 else
2924 a->vna_next = sizeof (Elf_External_Vernaux);
2926 _bfd_elf_swap_vernaux_out (output_bfd, a,
2927 (Elf_External_Vernaux *) p);
2928 p += sizeof (Elf_External_Vernaux);
2932 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
2933 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
2934 return false;
2936 elf_tdata (output_bfd)->cverrefs = crefs;
2940 dynsymcount = elf_hash_table (info)->dynsymcount;
2942 /* Work out the size of the symbol version section. */
2943 s = bfd_get_section_by_name (dynobj, ".gnu.version");
2944 BFD_ASSERT (s != NULL);
2945 if (dynsymcount == 0
2946 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
2948 elf_link_remove_section_and_adjust_dynindices (output_bfd,
2949 info,
2951 /* The DYNSYMCOUNT might have changed if we were going to
2952 output a dynamic symbol table entry for S. */
2953 dynsymcount = elf_hash_table (info)->dynsymcount;
2955 else
2957 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
2958 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
2959 if (s->contents == NULL)
2960 return false;
2962 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
2963 return false;
2966 /* Set the size of the .dynsym and .hash sections. We counted
2967 the number of dynamic symbols in elf_link_add_object_symbols.
2968 We will build the contents of .dynsym and .hash when we build
2969 the final symbol table, because until then we do not know the
2970 correct value to give the symbols. We built the .dynstr
2971 section as we went along in elf_link_add_object_symbols. */
2972 s = bfd_get_section_by_name (dynobj, ".dynsym");
2973 BFD_ASSERT (s != NULL);
2974 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
2975 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2976 if (s->contents == NULL && s->_raw_size != 0)
2977 return false;
2979 /* The first entry in .dynsym is a dummy symbol. */
2980 isym.st_value = 0;
2981 isym.st_size = 0;
2982 isym.st_name = 0;
2983 isym.st_info = 0;
2984 isym.st_other = 0;
2985 isym.st_shndx = 0;
2986 elf_swap_symbol_out (output_bfd, &isym,
2987 (PTR) (Elf_External_Sym *) s->contents);
2989 /* Compute the size of the hashing table. As a side effect this
2990 computes the hash values for all the names we export. */
2991 bucketcount = compute_bucket_count (info);
2993 s = bfd_get_section_by_name (dynobj, ".hash");
2994 BFD_ASSERT (s != NULL);
2995 s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
2996 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2997 if (s->contents == NULL)
2998 return false;
2999 memset (s->contents, 0, (size_t) s->_raw_size);
3001 put_word (output_bfd, bucketcount, s->contents);
3002 put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
3004 elf_hash_table (info)->bucketcount = bucketcount;
3006 s = bfd_get_section_by_name (dynobj, ".dynstr");
3007 BFD_ASSERT (s != NULL);
3008 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3010 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3011 return false;
3014 return true;
3017 /* Fix up the flags for a symbol. This handles various cases which
3018 can only be fixed after all the input files are seen. This is
3019 currently called by both adjust_dynamic_symbol and
3020 assign_sym_version, which is unnecessary but perhaps more robust in
3021 the face of future changes. */
3023 static boolean
3024 elf_fix_symbol_flags (h, eif)
3025 struct elf_link_hash_entry *h;
3026 struct elf_info_failed *eif;
3028 /* If this symbol was mentioned in a non-ELF file, try to set
3029 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3030 permit a non-ELF file to correctly refer to a symbol defined in
3031 an ELF dynamic object. */
3032 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3034 if (h->root.type != bfd_link_hash_defined
3035 && h->root.type != bfd_link_hash_defweak)
3036 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3037 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3038 else
3040 if (h->root.u.def.section->owner != NULL
3041 && (bfd_get_flavour (h->root.u.def.section->owner)
3042 == bfd_target_elf_flavour))
3043 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3044 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3045 else
3046 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3049 if (h->dynindx == -1
3050 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3051 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3053 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3055 eif->failed = true;
3056 return false;
3060 else
3062 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3063 was first seen in a non-ELF file. Fortunately, if the symbol
3064 was first seen in an ELF file, we're probably OK unless the
3065 symbol was defined in a non-ELF file. Catch that case here.
3066 FIXME: We're still in trouble if the symbol was first seen in
3067 a dynamic object, and then later in a non-ELF regular object. */
3068 if ((h->root.type == bfd_link_hash_defined
3069 || h->root.type == bfd_link_hash_defweak)
3070 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3071 && (h->root.u.def.section->owner != NULL
3072 ? (bfd_get_flavour (h->root.u.def.section->owner)
3073 != bfd_target_elf_flavour)
3074 : (bfd_is_abs_section (h->root.u.def.section)
3075 && (h->elf_link_hash_flags
3076 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3077 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3080 /* If this is a final link, and the symbol was defined as a common
3081 symbol in a regular object file, and there was no definition in
3082 any dynamic object, then the linker will have allocated space for
3083 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3084 flag will not have been set. */
3085 if (h->root.type == bfd_link_hash_defined
3086 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3087 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3088 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3089 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3090 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3092 /* If -Bsymbolic was used (which means to bind references to global
3093 symbols to the definition within the shared object), and this
3094 symbol was defined in a regular object, then it actually doesn't
3095 need a PLT entry. */
3096 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3097 && eif->info->shared
3098 && eif->info->symbolic
3099 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3101 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3102 h->plt.offset = (bfd_vma) -1;
3105 return true;
3108 /* Make the backend pick a good value for a dynamic symbol. This is
3109 called via elf_link_hash_traverse, and also calls itself
3110 recursively. */
3112 static boolean
3113 elf_adjust_dynamic_symbol (h, data)
3114 struct elf_link_hash_entry *h;
3115 PTR data;
3117 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3118 bfd *dynobj;
3119 struct elf_backend_data *bed;
3121 /* Ignore indirect symbols. These are added by the versioning code. */
3122 if (h->root.type == bfd_link_hash_indirect)
3123 return true;
3125 /* Fix the symbol flags. */
3126 if (! elf_fix_symbol_flags (h, eif))
3127 return false;
3129 /* If this symbol does not require a PLT entry, and it is not
3130 defined by a dynamic object, or is not referenced by a regular
3131 object, ignore it. We do have to handle a weak defined symbol,
3132 even if no regular object refers to it, if we decided to add it
3133 to the dynamic symbol table. FIXME: Do we normally need to worry
3134 about symbols which are defined by one dynamic object and
3135 referenced by another one? */
3136 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3137 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3138 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3139 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3140 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3142 h->plt.offset = (bfd_vma) -1;
3143 return true;
3146 /* If we've already adjusted this symbol, don't do it again. This
3147 can happen via a recursive call. */
3148 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3149 return true;
3151 /* Don't look at this symbol again. Note that we must set this
3152 after checking the above conditions, because we may look at a
3153 symbol once, decide not to do anything, and then get called
3154 recursively later after REF_REGULAR is set below. */
3155 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3157 /* If this is a weak definition, and we know a real definition, and
3158 the real symbol is not itself defined by a regular object file,
3159 then get a good value for the real definition. We handle the
3160 real symbol first, for the convenience of the backend routine.
3162 Note that there is a confusing case here. If the real definition
3163 is defined by a regular object file, we don't get the real symbol
3164 from the dynamic object, but we do get the weak symbol. If the
3165 processor backend uses a COPY reloc, then if some routine in the
3166 dynamic object changes the real symbol, we will not see that
3167 change in the corresponding weak symbol. This is the way other
3168 ELF linkers work as well, and seems to be a result of the shared
3169 library model.
3171 I will clarify this issue. Most SVR4 shared libraries define the
3172 variable _timezone and define timezone as a weak synonym. The
3173 tzset call changes _timezone. If you write
3174 extern int timezone;
3175 int _timezone = 5;
3176 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3177 you might expect that, since timezone is a synonym for _timezone,
3178 the same number will print both times. However, if the processor
3179 backend uses a COPY reloc, then actually timezone will be copied
3180 into your process image, and, since you define _timezone
3181 yourself, _timezone will not. Thus timezone and _timezone will
3182 wind up at different memory locations. The tzset call will set
3183 _timezone, leaving timezone unchanged. */
3185 if (h->weakdef != NULL)
3187 struct elf_link_hash_entry *weakdef;
3189 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3190 || h->root.type == bfd_link_hash_defweak);
3191 weakdef = h->weakdef;
3192 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3193 || weakdef->root.type == bfd_link_hash_defweak);
3194 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3195 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3197 /* This symbol is defined by a regular object file, so we
3198 will not do anything special. Clear weakdef for the
3199 convenience of the processor backend. */
3200 h->weakdef = NULL;
3202 else
3204 /* There is an implicit reference by a regular object file
3205 via the weak symbol. */
3206 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3207 if (h->weakdef->elf_link_hash_flags
3208 & ELF_LINK_HASH_REF_REGULAR_NONWEAK)
3209 weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
3210 if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif))
3211 return false;
3215 /* If a symbol has no type and no size and does not require a PLT
3216 entry, then we are probably about to do the wrong thing here: we
3217 are probably going to create a COPY reloc for an empty object.
3218 This case can arise when a shared object is built with assembly
3219 code, and the assembly code fails to set the symbol type. */
3220 if (h->size == 0
3221 && h->type == STT_NOTYPE
3222 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3223 (*_bfd_error_handler)
3224 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3225 h->root.root.string);
3227 dynobj = elf_hash_table (eif->info)->dynobj;
3228 bed = get_elf_backend_data (dynobj);
3229 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3231 eif->failed = true;
3232 return false;
3235 return true;
3238 /* This routine is used to export all defined symbols into the dynamic
3239 symbol table. It is called via elf_link_hash_traverse. */
3241 static boolean
3242 elf_export_symbol (h, data)
3243 struct elf_link_hash_entry *h;
3244 PTR data;
3246 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3248 /* Ignore indirect symbols. These are added by the versioning code. */
3249 if (h->root.type == bfd_link_hash_indirect)
3250 return true;
3252 if (h->dynindx == -1
3253 && (h->elf_link_hash_flags
3254 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3256 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3258 eif->failed = true;
3259 return false;
3263 return true;
3266 /* Look through the symbols which are defined in other shared
3267 libraries and referenced here. Update the list of version
3268 dependencies. This will be put into the .gnu.version_r section.
3269 This function is called via elf_link_hash_traverse. */
3271 static boolean
3272 elf_link_find_version_dependencies (h, data)
3273 struct elf_link_hash_entry *h;
3274 PTR data;
3276 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3277 Elf_Internal_Verneed *t;
3278 Elf_Internal_Vernaux *a;
3280 /* We only care about symbols defined in shared objects with version
3281 information. */
3282 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3283 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3284 || h->dynindx == -1
3285 || h->verinfo.verdef == NULL)
3286 return true;
3288 /* See if we already know about this version. */
3289 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3291 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3292 continue;
3294 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3295 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3296 return true;
3298 break;
3301 /* This is a new version. Add it to tree we are building. */
3303 if (t == NULL)
3305 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3306 if (t == NULL)
3308 rinfo->failed = true;
3309 return false;
3312 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3313 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3314 elf_tdata (rinfo->output_bfd)->verref = t;
3317 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3319 /* Note that we are copying a string pointer here, and testing it
3320 above. If bfd_elf_string_from_elf_section is ever changed to
3321 discard the string data when low in memory, this will have to be
3322 fixed. */
3323 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3325 a->vna_flags = h->verinfo.verdef->vd_flags;
3326 a->vna_nextptr = t->vn_auxptr;
3328 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3329 ++rinfo->vers;
3331 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3333 t->vn_auxptr = a;
3335 return true;
3338 /* Figure out appropriate versions for all the symbols. We may not
3339 have the version number script until we have read all of the input
3340 files, so until that point we don't know which symbols should be
3341 local. This function is called via elf_link_hash_traverse. */
3343 static boolean
3344 elf_link_assign_sym_version (h, data)
3345 struct elf_link_hash_entry *h;
3346 PTR data;
3348 struct elf_assign_sym_version_info *sinfo =
3349 (struct elf_assign_sym_version_info *) data;
3350 struct bfd_link_info *info = sinfo->info;
3351 struct elf_info_failed eif;
3352 char *p;
3354 /* Fix the symbol flags. */
3355 eif.failed = false;
3356 eif.info = info;
3357 if (! elf_fix_symbol_flags (h, &eif))
3359 if (eif.failed)
3360 sinfo->failed = true;
3361 return false;
3364 /* We only need version numbers for symbols defined in regular
3365 objects. */
3366 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3367 return true;
3369 p = strchr (h->root.root.string, ELF_VER_CHR);
3370 if (p != NULL && h->verinfo.vertree == NULL)
3372 struct bfd_elf_version_tree *t;
3373 boolean hidden;
3375 hidden = true;
3377 /* There are two consecutive ELF_VER_CHR characters if this is
3378 not a hidden symbol. */
3379 ++p;
3380 if (*p == ELF_VER_CHR)
3382 hidden = false;
3383 ++p;
3386 /* If there is no version string, we can just return out. */
3387 if (*p == '\0')
3389 if (hidden)
3390 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3391 return true;
3394 /* Look for the version. If we find it, it is no longer weak. */
3395 for (t = sinfo->verdefs; t != NULL; t = t->next)
3397 if (strcmp (t->name, p) == 0)
3399 int len;
3400 char *alc;
3401 struct bfd_elf_version_expr *d;
3403 len = p - h->root.root.string;
3404 alc = bfd_alloc (sinfo->output_bfd, len);
3405 if (alc == NULL)
3406 return false;
3407 strncpy (alc, h->root.root.string, len - 1);
3408 alc[len - 1] = '\0';
3409 if (alc[len - 2] == ELF_VER_CHR)
3410 alc[len - 2] = '\0';
3412 h->verinfo.vertree = t;
3413 t->used = true;
3414 d = NULL;
3416 if (t->globals != NULL)
3418 for (d = t->globals; d != NULL; d = d->next)
3419 if ((*d->match) (d, alc))
3420 break;
3423 /* See if there is anything to force this symbol to
3424 local scope. */
3425 if (d == NULL && t->locals != NULL)
3427 for (d = t->locals; d != NULL; d = d->next)
3429 if ((*d->match) (d, alc))
3431 if (h->dynindx != -1
3432 && info->shared
3433 && ! sinfo->export_dynamic)
3435 sinfo->removed_dynamic = true;
3436 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3437 h->elf_link_hash_flags &=~
3438 ELF_LINK_HASH_NEEDS_PLT;
3439 h->dynindx = -1;
3440 h->plt.offset = (bfd_vma) -1;
3441 /* FIXME: The name of the symbol has
3442 already been recorded in the dynamic
3443 string table section. */
3446 break;
3451 bfd_release (sinfo->output_bfd, alc);
3452 break;
3456 /* If we are building an application, we need to create a
3457 version node for this version. */
3458 if (t == NULL && ! info->shared)
3460 struct bfd_elf_version_tree **pp;
3461 int version_index;
3463 /* If we aren't going to export this symbol, we don't need
3464 to worry about it. */
3465 if (h->dynindx == -1)
3466 return true;
3468 t = ((struct bfd_elf_version_tree *)
3469 bfd_alloc (sinfo->output_bfd, sizeof *t));
3470 if (t == NULL)
3472 sinfo->failed = true;
3473 return false;
3476 t->next = NULL;
3477 t->name = p;
3478 t->globals = NULL;
3479 t->locals = NULL;
3480 t->deps = NULL;
3481 t->name_indx = (unsigned int) -1;
3482 t->used = true;
3484 version_index = 1;
3485 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3486 ++version_index;
3487 t->vernum = version_index;
3489 *pp = t;
3491 h->verinfo.vertree = t;
3493 else if (t == NULL)
3495 /* We could not find the version for a symbol when
3496 generating a shared archive. Return an error. */
3497 (*_bfd_error_handler)
3498 (_("%s: undefined versioned symbol name %s"),
3499 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3500 bfd_set_error (bfd_error_bad_value);
3501 sinfo->failed = true;
3502 return false;
3505 if (hidden)
3506 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3509 /* If we don't have a version for this symbol, see if we can find
3510 something. */
3511 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3513 struct bfd_elf_version_tree *t;
3514 struct bfd_elf_version_tree *deflt;
3515 struct bfd_elf_version_expr *d;
3517 /* See if can find what version this symbol is in. If the
3518 symbol is supposed to be local, then don't actually register
3519 it. */
3520 deflt = NULL;
3521 for (t = sinfo->verdefs; t != NULL; t = t->next)
3523 if (t->globals != NULL)
3525 for (d = t->globals; d != NULL; d = d->next)
3527 if ((*d->match) (d, h->root.root.string))
3529 h->verinfo.vertree = t;
3530 break;
3534 if (d != NULL)
3535 break;
3538 if (t->locals != NULL)
3540 for (d = t->locals; d != NULL; d = d->next)
3542 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3543 deflt = t;
3544 else if ((*d->match) (d, h->root.root.string))
3546 h->verinfo.vertree = t;
3547 if (h->dynindx != -1
3548 && info->shared
3549 && ! sinfo->export_dynamic)
3551 sinfo->removed_dynamic = true;
3552 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3553 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3554 h->dynindx = -1;
3555 h->plt.offset = (bfd_vma) -1;
3556 /* FIXME: The name of the symbol has already
3557 been recorded in the dynamic string table
3558 section. */
3560 break;
3564 if (d != NULL)
3565 break;
3569 if (deflt != NULL && h->verinfo.vertree == NULL)
3571 h->verinfo.vertree = deflt;
3572 if (h->dynindx != -1
3573 && info->shared
3574 && ! sinfo->export_dynamic)
3576 sinfo->removed_dynamic = true;
3577 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3578 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3579 h->dynindx = -1;
3580 h->plt.offset = (bfd_vma) -1;
3581 /* FIXME: The name of the symbol has already been
3582 recorded in the dynamic string table section. */
3587 return true;
3590 /* This function is used to renumber the dynamic symbols, if some of
3591 them are removed because they are marked as local. This is called
3592 via elf_link_hash_traverse. */
3594 static boolean
3595 elf_link_renumber_dynsyms (h, data)
3596 struct elf_link_hash_entry *h;
3597 PTR data;
3599 struct bfd_link_info *info = (struct bfd_link_info *) data;
3601 if (h->dynindx != -1)
3603 h->dynindx = elf_hash_table (info)->dynsymcount;
3604 ++elf_hash_table (info)->dynsymcount;
3607 return true;
3610 /* Final phase of ELF linker. */
3612 /* A structure we use to avoid passing large numbers of arguments. */
3614 struct elf_final_link_info
3616 /* General link information. */
3617 struct bfd_link_info *info;
3618 /* Output BFD. */
3619 bfd *output_bfd;
3620 /* Symbol string table. */
3621 struct bfd_strtab_hash *symstrtab;
3622 /* .dynsym section. */
3623 asection *dynsym_sec;
3624 /* .hash section. */
3625 asection *hash_sec;
3626 /* symbol version section (.gnu.version). */
3627 asection *symver_sec;
3628 /* Buffer large enough to hold contents of any section. */
3629 bfd_byte *contents;
3630 /* Buffer large enough to hold external relocs of any section. */
3631 PTR external_relocs;
3632 /* Buffer large enough to hold internal relocs of any section. */
3633 Elf_Internal_Rela *internal_relocs;
3634 /* Buffer large enough to hold external local symbols of any input
3635 BFD. */
3636 Elf_External_Sym *external_syms;
3637 /* Buffer large enough to hold internal local symbols of any input
3638 BFD. */
3639 Elf_Internal_Sym *internal_syms;
3640 /* Array large enough to hold a symbol index for each local symbol
3641 of any input BFD. */
3642 long *indices;
3643 /* Array large enough to hold a section pointer for each local
3644 symbol of any input BFD. */
3645 asection **sections;
3646 /* Buffer to hold swapped out symbols. */
3647 Elf_External_Sym *symbuf;
3648 /* Number of swapped out symbols in buffer. */
3649 size_t symbuf_count;
3650 /* Number of symbols which fit in symbuf. */
3651 size_t symbuf_size;
3654 static boolean elf_link_output_sym
3655 PARAMS ((struct elf_final_link_info *, const char *,
3656 Elf_Internal_Sym *, asection *));
3657 static boolean elf_link_flush_output_syms
3658 PARAMS ((struct elf_final_link_info *));
3659 static boolean elf_link_output_extsym
3660 PARAMS ((struct elf_link_hash_entry *, PTR));
3661 static boolean elf_link_input_bfd
3662 PARAMS ((struct elf_final_link_info *, bfd *));
3663 static boolean elf_reloc_link_order
3664 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3665 struct bfd_link_order *));
3667 /* This struct is used to pass information to elf_link_output_extsym. */
3669 struct elf_outext_info
3671 boolean failed;
3672 boolean localsyms;
3673 struct elf_final_link_info *finfo;
3676 /* Do the final step of an ELF link. */
3678 boolean
3679 elf_bfd_final_link (abfd, info)
3680 bfd *abfd;
3681 struct bfd_link_info *info;
3683 boolean dynamic;
3684 bfd *dynobj;
3685 struct elf_final_link_info finfo;
3686 register asection *o;
3687 register struct bfd_link_order *p;
3688 register bfd *sub;
3689 size_t max_contents_size;
3690 size_t max_external_reloc_size;
3691 size_t max_internal_reloc_count;
3692 size_t max_sym_count;
3693 file_ptr off;
3694 Elf_Internal_Sym elfsym;
3695 unsigned int i;
3696 Elf_Internal_Shdr *symtab_hdr;
3697 Elf_Internal_Shdr *symstrtab_hdr;
3698 struct elf_backend_data *bed = get_elf_backend_data (abfd);
3699 struct elf_outext_info eoinfo;
3701 if (info->shared)
3702 abfd->flags |= DYNAMIC;
3704 dynamic = elf_hash_table (info)->dynamic_sections_created;
3705 dynobj = elf_hash_table (info)->dynobj;
3707 finfo.info = info;
3708 finfo.output_bfd = abfd;
3709 finfo.symstrtab = elf_stringtab_init ();
3710 if (finfo.symstrtab == NULL)
3711 return false;
3713 if (! dynamic)
3715 finfo.dynsym_sec = NULL;
3716 finfo.hash_sec = NULL;
3717 finfo.symver_sec = NULL;
3719 else
3721 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
3722 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
3723 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
3724 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
3725 /* Note that it is OK if symver_sec is NULL. */
3728 finfo.contents = NULL;
3729 finfo.external_relocs = NULL;
3730 finfo.internal_relocs = NULL;
3731 finfo.external_syms = NULL;
3732 finfo.internal_syms = NULL;
3733 finfo.indices = NULL;
3734 finfo.sections = NULL;
3735 finfo.symbuf = NULL;
3736 finfo.symbuf_count = 0;
3738 /* Count up the number of relocations we will output for each output
3739 section, so that we know the sizes of the reloc sections. We
3740 also figure out some maximum sizes. */
3741 max_contents_size = 0;
3742 max_external_reloc_size = 0;
3743 max_internal_reloc_count = 0;
3744 max_sym_count = 0;
3745 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
3747 o->reloc_count = 0;
3749 for (p = o->link_order_head; p != NULL; p = p->next)
3751 if (p->type == bfd_section_reloc_link_order
3752 || p->type == bfd_symbol_reloc_link_order)
3753 ++o->reloc_count;
3754 else if (p->type == bfd_indirect_link_order)
3756 asection *sec;
3758 sec = p->u.indirect.section;
3760 /* Mark all sections which are to be included in the
3761 link. This will normally be every section. We need
3762 to do this so that we can identify any sections which
3763 the linker has decided to not include. */
3764 sec->linker_mark = true;
3766 if (info->relocateable)
3767 o->reloc_count += sec->reloc_count;
3769 if (sec->_raw_size > max_contents_size)
3770 max_contents_size = sec->_raw_size;
3771 if (sec->_cooked_size > max_contents_size)
3772 max_contents_size = sec->_cooked_size;
3774 /* We are interested in just local symbols, not all
3775 symbols. */
3776 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
3777 && (sec->owner->flags & DYNAMIC) == 0)
3779 size_t sym_count;
3781 if (elf_bad_symtab (sec->owner))
3782 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
3783 / sizeof (Elf_External_Sym));
3784 else
3785 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
3787 if (sym_count > max_sym_count)
3788 max_sym_count = sym_count;
3790 if ((sec->flags & SEC_RELOC) != 0)
3792 size_t ext_size;
3794 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
3795 if (ext_size > max_external_reloc_size)
3796 max_external_reloc_size = ext_size;
3797 if (sec->reloc_count > max_internal_reloc_count)
3798 max_internal_reloc_count = sec->reloc_count;
3804 if (o->reloc_count > 0)
3805 o->flags |= SEC_RELOC;
3806 else
3808 /* Explicitly clear the SEC_RELOC flag. The linker tends to
3809 set it (this is probably a bug) and if it is set
3810 assign_section_numbers will create a reloc section. */
3811 o->flags &=~ SEC_RELOC;
3814 /* If the SEC_ALLOC flag is not set, force the section VMA to
3815 zero. This is done in elf_fake_sections as well, but forcing
3816 the VMA to 0 here will ensure that relocs against these
3817 sections are handled correctly. */
3818 if ((o->flags & SEC_ALLOC) == 0
3819 && ! o->user_set_vma)
3820 o->vma = 0;
3823 /* Figure out the file positions for everything but the symbol table
3824 and the relocs. We set symcount to force assign_section_numbers
3825 to create a symbol table. */
3826 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
3827 BFD_ASSERT (! abfd->output_has_begun);
3828 if (! _bfd_elf_compute_section_file_positions (abfd, info))
3829 goto error_return;
3831 /* That created the reloc sections. Set their sizes, and assign
3832 them file positions, and allocate some buffers. */
3833 for (o = abfd->sections; o != NULL; o = o->next)
3835 if ((o->flags & SEC_RELOC) != 0)
3837 Elf_Internal_Shdr *rel_hdr;
3838 register struct elf_link_hash_entry **p, **pend;
3840 rel_hdr = &elf_section_data (o)->rel_hdr;
3842 rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
3844 /* The contents field must last into write_object_contents,
3845 so we allocate it with bfd_alloc rather than malloc. */
3846 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
3847 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
3848 goto error_return;
3850 p = ((struct elf_link_hash_entry **)
3851 bfd_malloc (o->reloc_count
3852 * sizeof (struct elf_link_hash_entry *)));
3853 if (p == NULL && o->reloc_count != 0)
3854 goto error_return;
3855 elf_section_data (o)->rel_hashes = p;
3856 pend = p + o->reloc_count;
3857 for (; p < pend; p++)
3858 *p = NULL;
3860 /* Use the reloc_count field as an index when outputting the
3861 relocs. */
3862 o->reloc_count = 0;
3866 _bfd_elf_assign_file_positions_for_relocs (abfd);
3868 /* We have now assigned file positions for all the sections except
3869 .symtab and .strtab. We start the .symtab section at the current
3870 file position, and write directly to it. We build the .strtab
3871 section in memory. */
3872 bfd_get_symcount (abfd) = 0;
3873 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
3874 /* sh_name is set in prep_headers. */
3875 symtab_hdr->sh_type = SHT_SYMTAB;
3876 symtab_hdr->sh_flags = 0;
3877 symtab_hdr->sh_addr = 0;
3878 symtab_hdr->sh_size = 0;
3879 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
3880 /* sh_link is set in assign_section_numbers. */
3881 /* sh_info is set below. */
3882 /* sh_offset is set just below. */
3883 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
3885 off = elf_tdata (abfd)->next_file_pos;
3886 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
3888 /* Note that at this point elf_tdata (abfd)->next_file_pos is
3889 incorrect. We do not yet know the size of the .symtab section.
3890 We correct next_file_pos below, after we do know the size. */
3892 /* Allocate a buffer to hold swapped out symbols. This is to avoid
3893 continuously seeking to the right position in the file. */
3894 if (! info->keep_memory || max_sym_count < 20)
3895 finfo.symbuf_size = 20;
3896 else
3897 finfo.symbuf_size = max_sym_count;
3898 finfo.symbuf = ((Elf_External_Sym *)
3899 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
3900 if (finfo.symbuf == NULL)
3901 goto error_return;
3903 /* Start writing out the symbol table. The first symbol is always a
3904 dummy symbol. */
3905 if (info->strip != strip_all || info->relocateable)
3907 elfsym.st_value = 0;
3908 elfsym.st_size = 0;
3909 elfsym.st_info = 0;
3910 elfsym.st_other = 0;
3911 elfsym.st_shndx = SHN_UNDEF;
3912 if (! elf_link_output_sym (&finfo, (const char *) NULL,
3913 &elfsym, bfd_und_section_ptr))
3914 goto error_return;
3917 #if 0
3918 /* Some standard ELF linkers do this, but we don't because it causes
3919 bootstrap comparison failures. */
3920 /* Output a file symbol for the output file as the second symbol.
3921 We output this even if we are discarding local symbols, although
3922 I'm not sure if this is correct. */
3923 elfsym.st_value = 0;
3924 elfsym.st_size = 0;
3925 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
3926 elfsym.st_other = 0;
3927 elfsym.st_shndx = SHN_ABS;
3928 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
3929 &elfsym, bfd_abs_section_ptr))
3930 goto error_return;
3931 #endif
3933 /* Output a symbol for each section. We output these even if we are
3934 discarding local symbols, since they are used for relocs. These
3935 symbols have no names. We store the index of each one in the
3936 index field of the section, so that we can find it again when
3937 outputting relocs. */
3938 if (info->strip != strip_all || info->relocateable)
3940 elfsym.st_size = 0;
3941 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
3942 elfsym.st_other = 0;
3943 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
3945 o = section_from_elf_index (abfd, i);
3946 if (o != NULL)
3947 o->target_index = bfd_get_symcount (abfd);
3948 elfsym.st_shndx = i;
3949 if (info->relocateable || o == NULL)
3950 elfsym.st_value = 0;
3951 else
3952 elfsym.st_value = o->vma;
3953 if (! elf_link_output_sym (&finfo, (const char *) NULL,
3954 &elfsym, o))
3955 goto error_return;
3959 /* Allocate some memory to hold information read in from the input
3960 files. */
3961 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
3962 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
3963 finfo.internal_relocs = ((Elf_Internal_Rela *)
3964 bfd_malloc (max_internal_reloc_count
3965 * sizeof (Elf_Internal_Rela)));
3966 finfo.external_syms = ((Elf_External_Sym *)
3967 bfd_malloc (max_sym_count
3968 * sizeof (Elf_External_Sym)));
3969 finfo.internal_syms = ((Elf_Internal_Sym *)
3970 bfd_malloc (max_sym_count
3971 * sizeof (Elf_Internal_Sym)));
3972 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
3973 finfo.sections = ((asection **)
3974 bfd_malloc (max_sym_count * sizeof (asection *)));
3975 if ((finfo.contents == NULL && max_contents_size != 0)
3976 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
3977 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
3978 || (finfo.external_syms == NULL && max_sym_count != 0)
3979 || (finfo.internal_syms == NULL && max_sym_count != 0)
3980 || (finfo.indices == NULL && max_sym_count != 0)
3981 || (finfo.sections == NULL && max_sym_count != 0))
3982 goto error_return;
3984 /* Since ELF permits relocations to be against local symbols, we
3985 must have the local symbols available when we do the relocations.
3986 Since we would rather only read the local symbols once, and we
3987 would rather not keep them in memory, we handle all the
3988 relocations for a single input file at the same time.
3990 Unfortunately, there is no way to know the total number of local
3991 symbols until we have seen all of them, and the local symbol
3992 indices precede the global symbol indices. This means that when
3993 we are generating relocateable output, and we see a reloc against
3994 a global symbol, we can not know the symbol index until we have
3995 finished examining all the local symbols to see which ones we are
3996 going to output. To deal with this, we keep the relocations in
3997 memory, and don't output them until the end of the link. This is
3998 an unfortunate waste of memory, but I don't see a good way around
3999 it. Fortunately, it only happens when performing a relocateable
4000 link, which is not the common case. FIXME: If keep_memory is set
4001 we could write the relocs out and then read them again; I don't
4002 know how bad the memory loss will be. */
4004 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4005 sub->output_has_begun = false;
4006 for (o = abfd->sections; o != NULL; o = o->next)
4008 for (p = o->link_order_head; p != NULL; p = p->next)
4010 if (p->type == bfd_indirect_link_order
4011 && (bfd_get_flavour (p->u.indirect.section->owner)
4012 == bfd_target_elf_flavour))
4014 sub = p->u.indirect.section->owner;
4015 if (! sub->output_has_begun)
4017 if (! elf_link_input_bfd (&finfo, sub))
4018 goto error_return;
4019 sub->output_has_begun = true;
4022 else if (p->type == bfd_section_reloc_link_order
4023 || p->type == bfd_symbol_reloc_link_order)
4025 if (! elf_reloc_link_order (abfd, info, o, p))
4026 goto error_return;
4028 else
4030 if (! _bfd_default_link_order (abfd, info, o, p))
4031 goto error_return;
4036 /* That wrote out all the local symbols. Finish up the symbol table
4037 with the global symbols. */
4039 if (info->strip != strip_all && info->shared)
4041 /* Output any global symbols that got converted to local in a
4042 version script. We do this in a separate step since ELF
4043 requires all local symbols to appear prior to any global
4044 symbols. FIXME: We should only do this if some global
4045 symbols were, in fact, converted to become local. FIXME:
4046 Will this work correctly with the Irix 5 linker? */
4047 eoinfo.failed = false;
4048 eoinfo.finfo = &finfo;
4049 eoinfo.localsyms = true;
4050 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4051 (PTR) &eoinfo);
4052 if (eoinfo.failed)
4053 return false;
4056 /* The sh_info field records the index of the first non local
4057 symbol. */
4058 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4059 if (dynamic)
4060 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1;
4062 /* We get the global symbols from the hash table. */
4063 eoinfo.failed = false;
4064 eoinfo.localsyms = false;
4065 eoinfo.finfo = &finfo;
4066 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4067 (PTR) &eoinfo);
4068 if (eoinfo.failed)
4069 return false;
4071 /* Flush all symbols to the file. */
4072 if (! elf_link_flush_output_syms (&finfo))
4073 return false;
4075 /* Now we know the size of the symtab section. */
4076 off += symtab_hdr->sh_size;
4078 /* Finish up and write out the symbol string table (.strtab)
4079 section. */
4080 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4081 /* sh_name was set in prep_headers. */
4082 symstrtab_hdr->sh_type = SHT_STRTAB;
4083 symstrtab_hdr->sh_flags = 0;
4084 symstrtab_hdr->sh_addr = 0;
4085 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4086 symstrtab_hdr->sh_entsize = 0;
4087 symstrtab_hdr->sh_link = 0;
4088 symstrtab_hdr->sh_info = 0;
4089 /* sh_offset is set just below. */
4090 symstrtab_hdr->sh_addralign = 1;
4092 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4093 elf_tdata (abfd)->next_file_pos = off;
4095 if (bfd_get_symcount (abfd) > 0)
4097 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4098 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4099 return false;
4102 /* Adjust the relocs to have the correct symbol indices. */
4103 for (o = abfd->sections; o != NULL; o = o->next)
4105 struct elf_link_hash_entry **rel_hash;
4106 Elf_Internal_Shdr *rel_hdr;
4108 if ((o->flags & SEC_RELOC) == 0)
4109 continue;
4111 rel_hash = elf_section_data (o)->rel_hashes;
4112 rel_hdr = &elf_section_data (o)->rel_hdr;
4113 for (i = 0; i < o->reloc_count; i++, rel_hash++)
4115 if (*rel_hash == NULL)
4116 continue;
4118 BFD_ASSERT ((*rel_hash)->indx >= 0);
4120 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4122 Elf_External_Rel *erel;
4123 Elf_Internal_Rel irel;
4125 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4126 elf_swap_reloc_in (abfd, erel, &irel);
4127 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4128 ELF_R_TYPE (irel.r_info));
4129 elf_swap_reloc_out (abfd, &irel, erel);
4131 else
4133 Elf_External_Rela *erela;
4134 Elf_Internal_Rela irela;
4136 BFD_ASSERT (rel_hdr->sh_entsize
4137 == sizeof (Elf_External_Rela));
4139 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4140 elf_swap_reloca_in (abfd, erela, &irela);
4141 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4142 ELF_R_TYPE (irela.r_info));
4143 elf_swap_reloca_out (abfd, &irela, erela);
4147 /* Set the reloc_count field to 0 to prevent write_relocs from
4148 trying to swap the relocs out itself. */
4149 o->reloc_count = 0;
4152 /* If we are linking against a dynamic object, or generating a
4153 shared library, finish up the dynamic linking information. */
4154 if (dynamic)
4156 Elf_External_Dyn *dyncon, *dynconend;
4158 /* Fix up .dynamic entries. */
4159 o = bfd_get_section_by_name (dynobj, ".dynamic");
4160 BFD_ASSERT (o != NULL);
4162 dyncon = (Elf_External_Dyn *) o->contents;
4163 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4164 for (; dyncon < dynconend; dyncon++)
4166 Elf_Internal_Dyn dyn;
4167 const char *name;
4168 unsigned int type;
4170 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4172 switch (dyn.d_tag)
4174 default:
4175 break;
4177 /* SVR4 linkers seem to set DT_INIT and DT_FINI based on
4178 magic _init and _fini symbols. This is pretty ugly,
4179 but we are compatible. */
4180 case DT_INIT:
4181 name = "_init";
4182 goto get_sym;
4183 case DT_FINI:
4184 name = "_fini";
4185 get_sym:
4187 struct elf_link_hash_entry *h;
4189 h = elf_link_hash_lookup (elf_hash_table (info), name,
4190 false, false, true);
4191 if (h != NULL
4192 && (h->root.type == bfd_link_hash_defined
4193 || h->root.type == bfd_link_hash_defweak))
4195 dyn.d_un.d_val = h->root.u.def.value;
4196 o = h->root.u.def.section;
4197 if (o->output_section != NULL)
4198 dyn.d_un.d_val += (o->output_section->vma
4199 + o->output_offset);
4200 else
4202 /* The symbol is imported from another shared
4203 library and does not apply to this one. */
4204 dyn.d_un.d_val = 0;
4207 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4210 break;
4212 case DT_HASH:
4213 name = ".hash";
4214 goto get_vma;
4215 case DT_STRTAB:
4216 name = ".dynstr";
4217 goto get_vma;
4218 case DT_SYMTAB:
4219 name = ".dynsym";
4220 goto get_vma;
4221 case DT_VERDEF:
4222 name = ".gnu.version_d";
4223 goto get_vma;
4224 case DT_VERNEED:
4225 name = ".gnu.version_r";
4226 goto get_vma;
4227 case DT_VERSYM:
4228 name = ".gnu.version";
4229 get_vma:
4230 o = bfd_get_section_by_name (abfd, name);
4231 BFD_ASSERT (o != NULL);
4232 dyn.d_un.d_ptr = o->vma;
4233 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4234 break;
4236 case DT_REL:
4237 case DT_RELA:
4238 case DT_RELSZ:
4239 case DT_RELASZ:
4240 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4241 type = SHT_REL;
4242 else
4243 type = SHT_RELA;
4244 dyn.d_un.d_val = 0;
4245 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4247 Elf_Internal_Shdr *hdr;
4249 hdr = elf_elfsections (abfd)[i];
4250 if (hdr->sh_type == type
4251 && (hdr->sh_flags & SHF_ALLOC) != 0)
4253 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4254 dyn.d_un.d_val += hdr->sh_size;
4255 else
4257 if (dyn.d_un.d_val == 0
4258 || hdr->sh_addr < dyn.d_un.d_val)
4259 dyn.d_un.d_val = hdr->sh_addr;
4263 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4264 break;
4269 /* If we have created any dynamic sections, then output them. */
4270 if (dynobj != NULL)
4272 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4273 goto error_return;
4275 for (o = dynobj->sections; o != NULL; o = o->next)
4277 if ((o->flags & SEC_HAS_CONTENTS) == 0
4278 || o->_raw_size == 0)
4279 continue;
4280 if ((o->flags & SEC_LINKER_CREATED) == 0)
4282 /* At this point, we are only interested in sections
4283 created by elf_link_create_dynamic_sections. */
4284 continue;
4286 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4287 != SHT_STRTAB)
4288 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4290 if (! bfd_set_section_contents (abfd, o->output_section,
4291 o->contents, o->output_offset,
4292 o->_raw_size))
4293 goto error_return;
4295 else
4297 file_ptr off;
4299 /* The contents of the .dynstr section are actually in a
4300 stringtab. */
4301 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4302 if (bfd_seek (abfd, off, SEEK_SET) != 0
4303 || ! _bfd_stringtab_emit (abfd,
4304 elf_hash_table (info)->dynstr))
4305 goto error_return;
4310 /* If we have optimized stabs strings, output them. */
4311 if (elf_hash_table (info)->stab_info != NULL)
4313 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4314 goto error_return;
4317 if (finfo.symstrtab != NULL)
4318 _bfd_stringtab_free (finfo.symstrtab);
4319 if (finfo.contents != NULL)
4320 free (finfo.contents);
4321 if (finfo.external_relocs != NULL)
4322 free (finfo.external_relocs);
4323 if (finfo.internal_relocs != NULL)
4324 free (finfo.internal_relocs);
4325 if (finfo.external_syms != NULL)
4326 free (finfo.external_syms);
4327 if (finfo.internal_syms != NULL)
4328 free (finfo.internal_syms);
4329 if (finfo.indices != NULL)
4330 free (finfo.indices);
4331 if (finfo.sections != NULL)
4332 free (finfo.sections);
4333 if (finfo.symbuf != NULL)
4334 free (finfo.symbuf);
4335 for (o = abfd->sections; o != NULL; o = o->next)
4337 if ((o->flags & SEC_RELOC) != 0
4338 && elf_section_data (o)->rel_hashes != NULL)
4339 free (elf_section_data (o)->rel_hashes);
4342 elf_tdata (abfd)->linker = true;
4344 return true;
4346 error_return:
4347 if (finfo.symstrtab != NULL)
4348 _bfd_stringtab_free (finfo.symstrtab);
4349 if (finfo.contents != NULL)
4350 free (finfo.contents);
4351 if (finfo.external_relocs != NULL)
4352 free (finfo.external_relocs);
4353 if (finfo.internal_relocs != NULL)
4354 free (finfo.internal_relocs);
4355 if (finfo.external_syms != NULL)
4356 free (finfo.external_syms);
4357 if (finfo.internal_syms != NULL)
4358 free (finfo.internal_syms);
4359 if (finfo.indices != NULL)
4360 free (finfo.indices);
4361 if (finfo.sections != NULL)
4362 free (finfo.sections);
4363 if (finfo.symbuf != NULL)
4364 free (finfo.symbuf);
4365 for (o = abfd->sections; o != NULL; o = o->next)
4367 if ((o->flags & SEC_RELOC) != 0
4368 && elf_section_data (o)->rel_hashes != NULL)
4369 free (elf_section_data (o)->rel_hashes);
4372 return false;
4375 /* Add a symbol to the output symbol table. */
4377 static boolean
4378 elf_link_output_sym (finfo, name, elfsym, input_sec)
4379 struct elf_final_link_info *finfo;
4380 const char *name;
4381 Elf_Internal_Sym *elfsym;
4382 asection *input_sec;
4384 boolean (*output_symbol_hook) PARAMS ((bfd *,
4385 struct bfd_link_info *info,
4386 const char *,
4387 Elf_Internal_Sym *,
4388 asection *));
4390 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4391 elf_backend_link_output_symbol_hook;
4392 if (output_symbol_hook != NULL)
4394 if (! ((*output_symbol_hook)
4395 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4396 return false;
4399 if (name == (const char *) NULL || *name == '\0')
4400 elfsym->st_name = 0;
4401 else if (input_sec->flags & SEC_EXCLUDE)
4402 elfsym->st_name = 0;
4403 else
4405 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4406 name, true,
4407 false);
4408 if (elfsym->st_name == (unsigned long) -1)
4409 return false;
4412 if (finfo->symbuf_count >= finfo->symbuf_size)
4414 if (! elf_link_flush_output_syms (finfo))
4415 return false;
4418 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4419 (PTR) (finfo->symbuf + finfo->symbuf_count));
4420 ++finfo->symbuf_count;
4422 ++ bfd_get_symcount (finfo->output_bfd);
4424 return true;
4427 /* Flush the output symbols to the file. */
4429 static boolean
4430 elf_link_flush_output_syms (finfo)
4431 struct elf_final_link_info *finfo;
4433 if (finfo->symbuf_count > 0)
4435 Elf_Internal_Shdr *symtab;
4437 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4439 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4440 SEEK_SET) != 0
4441 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4442 sizeof (Elf_External_Sym), finfo->output_bfd)
4443 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4444 return false;
4446 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4448 finfo->symbuf_count = 0;
4451 return true;
4454 /* Add an external symbol to the symbol table. This is called from
4455 the hash table traversal routine. When generating a shared object,
4456 we go through the symbol table twice. The first time we output
4457 anything that might have been forced to local scope in a version
4458 script. The second time we output the symbols that are still
4459 global symbols. */
4461 static boolean
4462 elf_link_output_extsym (h, data)
4463 struct elf_link_hash_entry *h;
4464 PTR data;
4466 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4467 struct elf_final_link_info *finfo = eoinfo->finfo;
4468 boolean strip;
4469 Elf_Internal_Sym sym;
4470 asection *input_sec;
4472 /* Decide whether to output this symbol in this pass. */
4473 if (eoinfo->localsyms)
4475 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4476 return true;
4478 else
4480 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4481 return true;
4484 /* If we are not creating a shared library, and this symbol is
4485 referenced by a shared library but is not defined anywhere, then
4486 warn that it is undefined. If we do not do this, the runtime
4487 linker will complain that the symbol is undefined when the
4488 program is run. We don't have to worry about symbols that are
4489 referenced by regular files, because we will already have issued
4490 warnings for them. */
4491 if (! finfo->info->relocateable
4492 && ! (finfo->info->shared
4493 && !finfo->info->symbolic
4494 && !finfo->info->no_undefined)
4495 && h->root.type == bfd_link_hash_undefined
4496 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
4497 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4499 if (! ((*finfo->info->callbacks->undefined_symbol)
4500 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
4501 (asection *) NULL, 0)))
4503 eoinfo->failed = true;
4504 return false;
4508 /* We don't want to output symbols that have never been mentioned by
4509 a regular file, or that we have been told to strip. However, if
4510 h->indx is set to -2, the symbol is used by a reloc and we must
4511 output it. */
4512 if (h->indx == -2)
4513 strip = false;
4514 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
4515 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
4516 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
4517 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4518 strip = true;
4519 else if (finfo->info->strip == strip_all
4520 || (finfo->info->strip == strip_some
4521 && bfd_hash_lookup (finfo->info->keep_hash,
4522 h->root.root.string,
4523 false, false) == NULL))
4524 strip = true;
4525 else
4526 strip = false;
4528 /* If we're stripping it, and it's not a dynamic symbol, there's
4529 nothing else to do. */
4530 if (strip && h->dynindx == -1)
4531 return true;
4533 sym.st_value = 0;
4534 sym.st_size = h->size;
4535 sym.st_other = h->other;
4536 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4537 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
4538 else if (h->root.type == bfd_link_hash_undefweak
4539 || h->root.type == bfd_link_hash_defweak)
4540 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
4541 else
4542 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
4544 switch (h->root.type)
4546 default:
4547 case bfd_link_hash_new:
4548 abort ();
4549 return false;
4551 case bfd_link_hash_undefined:
4552 input_sec = bfd_und_section_ptr;
4553 sym.st_shndx = SHN_UNDEF;
4554 break;
4556 case bfd_link_hash_undefweak:
4557 input_sec = bfd_und_section_ptr;
4558 sym.st_shndx = SHN_UNDEF;
4559 break;
4561 case bfd_link_hash_defined:
4562 case bfd_link_hash_defweak:
4564 input_sec = h->root.u.def.section;
4565 if (input_sec->output_section != NULL)
4567 sym.st_shndx =
4568 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
4569 input_sec->output_section);
4570 if (sym.st_shndx == (unsigned short) -1)
4572 (*_bfd_error_handler)
4573 (_("%s: could not find output section %s for input section %s"),
4574 bfd_get_filename (finfo->output_bfd),
4575 input_sec->output_section->name,
4576 input_sec->name);
4577 eoinfo->failed = true;
4578 return false;
4581 /* ELF symbols in relocateable files are section relative,
4582 but in nonrelocateable files they are virtual
4583 addresses. */
4584 sym.st_value = h->root.u.def.value + input_sec->output_offset;
4585 if (! finfo->info->relocateable)
4586 sym.st_value += input_sec->output_section->vma;
4588 else
4590 BFD_ASSERT (input_sec->owner == NULL
4591 || (input_sec->owner->flags & DYNAMIC) != 0);
4592 sym.st_shndx = SHN_UNDEF;
4593 input_sec = bfd_und_section_ptr;
4596 break;
4598 case bfd_link_hash_common:
4599 input_sec = h->root.u.c.p->section;
4600 sym.st_shndx = SHN_COMMON;
4601 sym.st_value = 1 << h->root.u.c.p->alignment_power;
4602 break;
4604 case bfd_link_hash_indirect:
4605 /* These symbols are created by symbol versioning. They point
4606 to the decorated version of the name. For example, if the
4607 symbol foo@@GNU_1.2 is the default, which should be used when
4608 foo is used with no version, then we add an indirect symbol
4609 foo which points to foo@@GNU_1.2. We ignore these symbols,
4610 since the indirected symbol is already in the hash table. If
4611 the indirect symbol is non-ELF, fall through and output it. */
4612 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) == 0)
4613 return true;
4615 /* Fall through. */
4616 case bfd_link_hash_warning:
4617 /* We can't represent these symbols in ELF, although a warning
4618 symbol may have come from a .gnu.warning.SYMBOL section. We
4619 just put the target symbol in the hash table. If the target
4620 symbol does not really exist, don't do anything. */
4621 if (h->root.u.i.link->type == bfd_link_hash_new)
4622 return true;
4623 return (elf_link_output_extsym
4624 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
4627 /* Give the processor backend a chance to tweak the symbol value,
4628 and also to finish up anything that needs to be done for this
4629 symbol. */
4630 if ((h->dynindx != -1
4631 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4632 && elf_hash_table (finfo->info)->dynamic_sections_created)
4634 struct elf_backend_data *bed;
4636 bed = get_elf_backend_data (finfo->output_bfd);
4637 if (! ((*bed->elf_backend_finish_dynamic_symbol)
4638 (finfo->output_bfd, finfo->info, h, &sym)))
4640 eoinfo->failed = true;
4641 return false;
4645 /* If we are marking the symbol as undefined, and there are no
4646 non-weak references to this symbol from a regular object, then
4647 mark the symbol as weak undefined. We can't do this earlier,
4648 because it might not be marked as undefined until the
4649 finish_dynamic_symbol routine gets through with it. */
4650 if (sym.st_shndx == SHN_UNDEF
4651 && sym.st_info == ELF_ST_INFO (STB_GLOBAL, h->type)
4652 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
4653 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) == 0)
4654 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
4656 /* If this symbol should be put in the .dynsym section, then put it
4657 there now. We have already know the symbol index. We also fill
4658 in the entry in the .hash section. */
4659 if (h->dynindx != -1
4660 && elf_hash_table (finfo->info)->dynamic_sections_created)
4662 size_t bucketcount;
4663 size_t bucket;
4664 bfd_byte *bucketpos;
4665 bfd_vma chain;
4667 sym.st_name = h->dynstr_index;
4669 elf_swap_symbol_out (finfo->output_bfd, &sym,
4670 (PTR) (((Elf_External_Sym *)
4671 finfo->dynsym_sec->contents)
4672 + h->dynindx));
4674 bucketcount = elf_hash_table (finfo->info)->bucketcount;
4675 bucket = h->elf_hash_value % bucketcount;
4676 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
4677 + (bucket + 2) * (ARCH_SIZE / 8));
4678 chain = get_word (finfo->output_bfd, bucketpos);
4679 put_word (finfo->output_bfd, h->dynindx, bucketpos);
4680 put_word (finfo->output_bfd, chain,
4681 ((bfd_byte *) finfo->hash_sec->contents
4682 + (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
4684 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
4686 Elf_Internal_Versym iversym;
4688 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
4690 if (h->verinfo.verdef == NULL)
4691 iversym.vs_vers = 0;
4692 else
4693 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
4695 else
4697 if (h->verinfo.vertree == NULL)
4698 iversym.vs_vers = 1;
4699 else
4700 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
4703 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
4704 iversym.vs_vers |= VERSYM_HIDDEN;
4706 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
4707 (((Elf_External_Versym *)
4708 finfo->symver_sec->contents)
4709 + h->dynindx));
4713 /* If we're stripping it, then it was just a dynamic symbol, and
4714 there's nothing else to do. */
4715 if (strip)
4716 return true;
4718 h->indx = bfd_get_symcount (finfo->output_bfd);
4720 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
4722 eoinfo->failed = true;
4723 return false;
4726 return true;
4729 /* Link an input file into the linker output file. This function
4730 handles all the sections and relocations of the input file at once.
4731 This is so that we only have to read the local symbols once, and
4732 don't have to keep them in memory. */
4734 static boolean
4735 elf_link_input_bfd (finfo, input_bfd)
4736 struct elf_final_link_info *finfo;
4737 bfd *input_bfd;
4739 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
4740 bfd *, asection *, bfd_byte *,
4741 Elf_Internal_Rela *,
4742 Elf_Internal_Sym *, asection **));
4743 bfd *output_bfd;
4744 Elf_Internal_Shdr *symtab_hdr;
4745 size_t locsymcount;
4746 size_t extsymoff;
4747 Elf_External_Sym *external_syms;
4748 Elf_External_Sym *esym;
4749 Elf_External_Sym *esymend;
4750 Elf_Internal_Sym *isym;
4751 long *pindex;
4752 asection **ppsection;
4753 asection *o;
4755 output_bfd = finfo->output_bfd;
4756 relocate_section =
4757 get_elf_backend_data (output_bfd)->elf_backend_relocate_section;
4759 /* If this is a dynamic object, we don't want to do anything here:
4760 we don't want the local symbols, and we don't want the section
4761 contents. */
4762 if ((input_bfd->flags & DYNAMIC) != 0)
4763 return true;
4765 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
4766 if (elf_bad_symtab (input_bfd))
4768 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
4769 extsymoff = 0;
4771 else
4773 locsymcount = symtab_hdr->sh_info;
4774 extsymoff = symtab_hdr->sh_info;
4777 /* Read the local symbols. */
4778 if (symtab_hdr->contents != NULL)
4779 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
4780 else if (locsymcount == 0)
4781 external_syms = NULL;
4782 else
4784 external_syms = finfo->external_syms;
4785 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
4786 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
4787 locsymcount, input_bfd)
4788 != locsymcount * sizeof (Elf_External_Sym)))
4789 return false;
4792 /* Swap in the local symbols and write out the ones which we know
4793 are going into the output file. */
4794 esym = external_syms;
4795 esymend = esym + locsymcount;
4796 isym = finfo->internal_syms;
4797 pindex = finfo->indices;
4798 ppsection = finfo->sections;
4799 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
4801 asection *isec;
4802 const char *name;
4803 Elf_Internal_Sym osym;
4805 elf_swap_symbol_in (input_bfd, esym, isym);
4806 *pindex = -1;
4808 if (elf_bad_symtab (input_bfd))
4810 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
4812 *ppsection = NULL;
4813 continue;
4817 if (isym->st_shndx == SHN_UNDEF)
4818 isec = bfd_und_section_ptr;
4819 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
4820 isec = section_from_elf_index (input_bfd, isym->st_shndx);
4821 else if (isym->st_shndx == SHN_ABS)
4822 isec = bfd_abs_section_ptr;
4823 else if (isym->st_shndx == SHN_COMMON)
4824 isec = bfd_com_section_ptr;
4825 else
4827 /* Who knows? */
4828 isec = NULL;
4831 *ppsection = isec;
4833 /* Don't output the first, undefined, symbol. */
4834 if (esym == external_syms)
4835 continue;
4837 /* If we are stripping all symbols, we don't want to output this
4838 one. */
4839 if (finfo->info->strip == strip_all)
4840 continue;
4842 /* We never output section symbols. Instead, we use the section
4843 symbol of the corresponding section in the output file. */
4844 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
4845 continue;
4847 /* If we are discarding all local symbols, we don't want to
4848 output this one. If we are generating a relocateable output
4849 file, then some of the local symbols may be required by
4850 relocs; we output them below as we discover that they are
4851 needed. */
4852 if (finfo->info->discard == discard_all)
4853 continue;
4855 /* If this symbol is defined in a section which we are
4856 discarding, we don't need to keep it, but note that
4857 linker_mark is only reliable for sections that have contents.
4858 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
4859 as well as linker_mark. */
4860 if (isym->st_shndx > 0
4861 && isym->st_shndx < SHN_LORESERVE
4862 && isec != NULL
4863 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
4864 || (! finfo->info->relocateable
4865 && (isec->flags & SEC_EXCLUDE) != 0)))
4866 continue;
4868 /* Get the name of the symbol. */
4869 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
4870 isym->st_name);
4871 if (name == NULL)
4872 return false;
4874 /* See if we are discarding symbols with this name. */
4875 if ((finfo->info->strip == strip_some
4876 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
4877 == NULL))
4878 || (finfo->info->discard == discard_l
4879 && bfd_is_local_label_name (input_bfd, name)))
4880 continue;
4882 /* If we get here, we are going to output this symbol. */
4884 osym = *isym;
4886 /* Adjust the section index for the output file. */
4887 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
4888 isec->output_section);
4889 if (osym.st_shndx == (unsigned short) -1)
4890 return false;
4892 *pindex = bfd_get_symcount (output_bfd);
4894 /* ELF symbols in relocateable files are section relative, but
4895 in executable files they are virtual addresses. Note that
4896 this code assumes that all ELF sections have an associated
4897 BFD section with a reasonable value for output_offset; below
4898 we assume that they also have a reasonable value for
4899 output_section. Any special sections must be set up to meet
4900 these requirements. */
4901 osym.st_value += isec->output_offset;
4902 if (! finfo->info->relocateable)
4903 osym.st_value += isec->output_section->vma;
4905 if (! elf_link_output_sym (finfo, name, &osym, isec))
4906 return false;
4909 /* Relocate the contents of each section. */
4910 for (o = input_bfd->sections; o != NULL; o = o->next)
4912 bfd_byte *contents;
4914 if (! o->linker_mark)
4916 /* This section was omitted from the link. */
4917 continue;
4920 if ((o->flags & SEC_HAS_CONTENTS) == 0
4921 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
4922 continue;
4924 if ((o->flags & SEC_LINKER_CREATED) != 0)
4926 /* Section was created by elf_link_create_dynamic_sections
4927 or somesuch. */
4928 continue;
4931 /* Get the contents of the section. They have been cached by a
4932 relaxation routine. Note that o is a section in an input
4933 file, so the contents field will not have been set by any of
4934 the routines which work on output files. */
4935 if (elf_section_data (o)->this_hdr.contents != NULL)
4936 contents = elf_section_data (o)->this_hdr.contents;
4937 else
4939 contents = finfo->contents;
4940 if (! bfd_get_section_contents (input_bfd, o, contents,
4941 (file_ptr) 0, o->_raw_size))
4942 return false;
4945 if ((o->flags & SEC_RELOC) != 0)
4947 Elf_Internal_Rela *internal_relocs;
4949 /* Get the swapped relocs. */
4950 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
4951 (input_bfd, o, finfo->external_relocs,
4952 finfo->internal_relocs, false));
4953 if (internal_relocs == NULL
4954 && o->reloc_count > 0)
4955 return false;
4957 /* Relocate the section by invoking a back end routine.
4959 The back end routine is responsible for adjusting the
4960 section contents as necessary, and (if using Rela relocs
4961 and generating a relocateable output file) adjusting the
4962 reloc addend as necessary.
4964 The back end routine does not have to worry about setting
4965 the reloc address or the reloc symbol index.
4967 The back end routine is given a pointer to the swapped in
4968 internal symbols, and can access the hash table entries
4969 for the external symbols via elf_sym_hashes (input_bfd).
4971 When generating relocateable output, the back end routine
4972 must handle STB_LOCAL/STT_SECTION symbols specially. The
4973 output symbol is going to be a section symbol
4974 corresponding to the output section, which will require
4975 the addend to be adjusted. */
4977 if (! (*relocate_section) (output_bfd, finfo->info,
4978 input_bfd, o, contents,
4979 internal_relocs,
4980 finfo->internal_syms,
4981 finfo->sections))
4982 return false;
4984 if (finfo->info->relocateable)
4986 Elf_Internal_Rela *irela;
4987 Elf_Internal_Rela *irelaend;
4988 struct elf_link_hash_entry **rel_hash;
4989 Elf_Internal_Shdr *input_rel_hdr;
4990 Elf_Internal_Shdr *output_rel_hdr;
4992 /* Adjust the reloc addresses and symbol indices. */
4994 irela = internal_relocs;
4995 irelaend = irela + o->reloc_count;
4996 rel_hash = (elf_section_data (o->output_section)->rel_hashes
4997 + o->output_section->reloc_count);
4998 for (; irela < irelaend; irela++, rel_hash++)
5000 unsigned long r_symndx;
5001 Elf_Internal_Sym *isym;
5002 asection *sec;
5004 irela->r_offset += o->output_offset;
5006 r_symndx = ELF_R_SYM (irela->r_info);
5008 if (r_symndx == 0)
5009 continue;
5011 if (r_symndx >= locsymcount
5012 || (elf_bad_symtab (input_bfd)
5013 && finfo->sections[r_symndx] == NULL))
5015 struct elf_link_hash_entry *rh;
5016 long indx;
5018 /* This is a reloc against a global symbol. We
5019 have not yet output all the local symbols, so
5020 we do not know the symbol index of any global
5021 symbol. We set the rel_hash entry for this
5022 reloc to point to the global hash table entry
5023 for this symbol. The symbol index is then
5024 set at the end of elf_bfd_final_link. */
5025 indx = r_symndx - extsymoff;
5026 rh = elf_sym_hashes (input_bfd)[indx];
5027 while (rh->root.type == bfd_link_hash_indirect
5028 || rh->root.type == bfd_link_hash_warning)
5029 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5031 /* Setting the index to -2 tells
5032 elf_link_output_extsym that this symbol is
5033 used by a reloc. */
5034 BFD_ASSERT (rh->indx < 0);
5035 rh->indx = -2;
5037 *rel_hash = rh;
5039 continue;
5042 /* This is a reloc against a local symbol. */
5044 *rel_hash = NULL;
5045 isym = finfo->internal_syms + r_symndx;
5046 sec = finfo->sections[r_symndx];
5047 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5049 /* I suppose the backend ought to fill in the
5050 section of any STT_SECTION symbol against a
5051 processor specific section. If we have
5052 discarded a section, the output_section will
5053 be the absolute section. */
5054 if (sec != NULL
5055 && (bfd_is_abs_section (sec)
5056 || (sec->output_section != NULL
5057 && bfd_is_abs_section (sec->output_section))))
5058 r_symndx = 0;
5059 else if (sec == NULL || sec->owner == NULL)
5061 bfd_set_error (bfd_error_bad_value);
5062 return false;
5064 else
5066 r_symndx = sec->output_section->target_index;
5067 BFD_ASSERT (r_symndx != 0);
5070 else
5072 if (finfo->indices[r_symndx] == -1)
5074 unsigned long link;
5075 const char *name;
5076 asection *osec;
5078 if (finfo->info->strip == strip_all)
5080 /* You can't do ld -r -s. */
5081 bfd_set_error (bfd_error_invalid_operation);
5082 return false;
5085 /* This symbol was skipped earlier, but
5086 since it is needed by a reloc, we
5087 must output it now. */
5088 link = symtab_hdr->sh_link;
5089 name = bfd_elf_string_from_elf_section (input_bfd,
5090 link,
5091 isym->st_name);
5092 if (name == NULL)
5093 return false;
5095 osec = sec->output_section;
5096 isym->st_shndx =
5097 _bfd_elf_section_from_bfd_section (output_bfd,
5098 osec);
5099 if (isym->st_shndx == (unsigned short) -1)
5100 return false;
5102 isym->st_value += sec->output_offset;
5103 if (! finfo->info->relocateable)
5104 isym->st_value += osec->vma;
5106 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5108 if (! elf_link_output_sym (finfo, name, isym, sec))
5109 return false;
5112 r_symndx = finfo->indices[r_symndx];
5115 irela->r_info = ELF_R_INFO (r_symndx,
5116 ELF_R_TYPE (irela->r_info));
5119 /* Swap out the relocs. */
5120 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5121 output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
5122 BFD_ASSERT (output_rel_hdr->sh_entsize
5123 == input_rel_hdr->sh_entsize);
5124 irela = internal_relocs;
5125 irelaend = irela + o->reloc_count;
5126 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5128 Elf_External_Rel *erel;
5130 erel = ((Elf_External_Rel *) output_rel_hdr->contents
5131 + o->output_section->reloc_count);
5132 for (; irela < irelaend; irela++, erel++)
5134 Elf_Internal_Rel irel;
5136 irel.r_offset = irela->r_offset;
5137 irel.r_info = irela->r_info;
5138 BFD_ASSERT (irela->r_addend == 0);
5139 elf_swap_reloc_out (output_bfd, &irel, erel);
5142 else
5144 Elf_External_Rela *erela;
5146 BFD_ASSERT (input_rel_hdr->sh_entsize
5147 == sizeof (Elf_External_Rela));
5148 erela = ((Elf_External_Rela *) output_rel_hdr->contents
5149 + o->output_section->reloc_count);
5150 for (; irela < irelaend; irela++, erela++)
5151 elf_swap_reloca_out (output_bfd, irela, erela);
5154 o->output_section->reloc_count += o->reloc_count;
5158 /* Write out the modified section contents. */
5159 if (elf_section_data (o)->stab_info == NULL)
5161 if (! (o->flags & SEC_EXCLUDE) &&
5162 ! bfd_set_section_contents (output_bfd, o->output_section,
5163 contents, o->output_offset,
5164 (o->_cooked_size != 0
5165 ? o->_cooked_size
5166 : o->_raw_size)))
5167 return false;
5169 else
5171 if (! (_bfd_write_section_stabs
5172 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5173 o, &elf_section_data (o)->stab_info, contents)))
5174 return false;
5178 return true;
5181 /* Generate a reloc when linking an ELF file. This is a reloc
5182 requested by the linker, and does come from any input file. This
5183 is used to build constructor and destructor tables when linking
5184 with -Ur. */
5186 static boolean
5187 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5188 bfd *output_bfd;
5189 struct bfd_link_info *info;
5190 asection *output_section;
5191 struct bfd_link_order *link_order;
5193 reloc_howto_type *howto;
5194 long indx;
5195 bfd_vma offset;
5196 bfd_vma addend;
5197 struct elf_link_hash_entry **rel_hash_ptr;
5198 Elf_Internal_Shdr *rel_hdr;
5200 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5201 if (howto == NULL)
5203 bfd_set_error (bfd_error_bad_value);
5204 return false;
5207 addend = link_order->u.reloc.p->addend;
5209 /* Figure out the symbol index. */
5210 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5211 + output_section->reloc_count);
5212 if (link_order->type == bfd_section_reloc_link_order)
5214 indx = link_order->u.reloc.p->u.section->target_index;
5215 BFD_ASSERT (indx != 0);
5216 *rel_hash_ptr = NULL;
5218 else
5220 struct elf_link_hash_entry *h;
5222 /* Treat a reloc against a defined symbol as though it were
5223 actually against the section. */
5224 h = ((struct elf_link_hash_entry *)
5225 bfd_wrapped_link_hash_lookup (output_bfd, info,
5226 link_order->u.reloc.p->u.name,
5227 false, false, true));
5228 if (h != NULL
5229 && (h->root.type == bfd_link_hash_defined
5230 || h->root.type == bfd_link_hash_defweak))
5232 asection *section;
5234 section = h->root.u.def.section;
5235 indx = section->output_section->target_index;
5236 *rel_hash_ptr = NULL;
5237 /* It seems that we ought to add the symbol value to the
5238 addend here, but in practice it has already been added
5239 because it was passed to constructor_callback. */
5240 addend += section->output_section->vma + section->output_offset;
5242 else if (h != NULL)
5244 /* Setting the index to -2 tells elf_link_output_extsym that
5245 this symbol is used by a reloc. */
5246 h->indx = -2;
5247 *rel_hash_ptr = h;
5248 indx = 0;
5250 else
5252 if (! ((*info->callbacks->unattached_reloc)
5253 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5254 (asection *) NULL, (bfd_vma) 0)))
5255 return false;
5256 indx = 0;
5260 /* If this is an inplace reloc, we must write the addend into the
5261 object file. */
5262 if (howto->partial_inplace && addend != 0)
5264 bfd_size_type size;
5265 bfd_reloc_status_type rstat;
5266 bfd_byte *buf;
5267 boolean ok;
5269 size = bfd_get_reloc_size (howto);
5270 buf = (bfd_byte *) bfd_zmalloc (size);
5271 if (buf == (bfd_byte *) NULL)
5272 return false;
5273 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5274 switch (rstat)
5276 case bfd_reloc_ok:
5277 break;
5278 default:
5279 case bfd_reloc_outofrange:
5280 abort ();
5281 case bfd_reloc_overflow:
5282 if (! ((*info->callbacks->reloc_overflow)
5283 (info,
5284 (link_order->type == bfd_section_reloc_link_order
5285 ? bfd_section_name (output_bfd,
5286 link_order->u.reloc.p->u.section)
5287 : link_order->u.reloc.p->u.name),
5288 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5289 (bfd_vma) 0)))
5291 free (buf);
5292 return false;
5294 break;
5296 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5297 (file_ptr) link_order->offset, size);
5298 free (buf);
5299 if (! ok)
5300 return false;
5303 /* The address of a reloc is relative to the section in a
5304 relocateable file, and is a virtual address in an executable
5305 file. */
5306 offset = link_order->offset;
5307 if (! info->relocateable)
5308 offset += output_section->vma;
5310 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5312 if (rel_hdr->sh_type == SHT_REL)
5314 Elf_Internal_Rel irel;
5315 Elf_External_Rel *erel;
5317 irel.r_offset = offset;
5318 irel.r_info = ELF_R_INFO (indx, howto->type);
5319 erel = ((Elf_External_Rel *) rel_hdr->contents
5320 + output_section->reloc_count);
5321 elf_swap_reloc_out (output_bfd, &irel, erel);
5323 else
5325 Elf_Internal_Rela irela;
5326 Elf_External_Rela *erela;
5328 irela.r_offset = offset;
5329 irela.r_info = ELF_R_INFO (indx, howto->type);
5330 irela.r_addend = addend;
5331 erela = ((Elf_External_Rela *) rel_hdr->contents
5332 + output_section->reloc_count);
5333 elf_swap_reloca_out (output_bfd, &irela, erela);
5336 ++output_section->reloc_count;
5338 return true;
5342 /* Allocate a pointer to live in a linker created section. */
5344 boolean
5345 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5346 bfd *abfd;
5347 struct bfd_link_info *info;
5348 elf_linker_section_t *lsect;
5349 struct elf_link_hash_entry *h;
5350 const Elf_Internal_Rela *rel;
5352 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5353 elf_linker_section_pointers_t *linker_section_ptr;
5354 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5356 BFD_ASSERT (lsect != NULL);
5358 /* Is this a global symbol? */
5359 if (h != NULL)
5361 /* Has this symbol already been allocated, if so, our work is done */
5362 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5363 rel->r_addend,
5364 lsect->which))
5365 return true;
5367 ptr_linker_section_ptr = &h->linker_section_pointer;
5368 /* Make sure this symbol is output as a dynamic symbol. */
5369 if (h->dynindx == -1)
5371 if (! elf_link_record_dynamic_symbol (info, h))
5372 return false;
5375 if (lsect->rel_section)
5376 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5379 else /* Allocation of a pointer to a local symbol */
5381 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5383 /* Allocate a table to hold the local symbols if first time */
5384 if (!ptr)
5386 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5387 register unsigned int i;
5389 ptr = (elf_linker_section_pointers_t **)
5390 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5392 if (!ptr)
5393 return false;
5395 elf_local_ptr_offsets (abfd) = ptr;
5396 for (i = 0; i < num_symbols; i++)
5397 ptr[i] = (elf_linker_section_pointers_t *)0;
5400 /* Has this symbol already been allocated, if so, our work is done */
5401 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5402 rel->r_addend,
5403 lsect->which))
5404 return true;
5406 ptr_linker_section_ptr = &ptr[r_symndx];
5408 if (info->shared)
5410 /* If we are generating a shared object, we need to
5411 output a R_<xxx>_RELATIVE reloc so that the
5412 dynamic linker can adjust this GOT entry. */
5413 BFD_ASSERT (lsect->rel_section != NULL);
5414 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5418 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
5419 from internal memory. */
5420 BFD_ASSERT (ptr_linker_section_ptr != NULL);
5421 linker_section_ptr = (elf_linker_section_pointers_t *)
5422 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
5424 if (!linker_section_ptr)
5425 return false;
5427 linker_section_ptr->next = *ptr_linker_section_ptr;
5428 linker_section_ptr->addend = rel->r_addend;
5429 linker_section_ptr->which = lsect->which;
5430 linker_section_ptr->written_address_p = false;
5431 *ptr_linker_section_ptr = linker_section_ptr;
5433 #if 0
5434 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
5436 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
5437 lsect->hole_offset += ARCH_SIZE / 8;
5438 lsect->sym_offset += ARCH_SIZE / 8;
5439 if (lsect->sym_hash) /* Bump up symbol value if needed */
5441 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
5442 #ifdef DEBUG
5443 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
5444 lsect->sym_hash->root.root.string,
5445 (long)ARCH_SIZE / 8,
5446 (long)lsect->sym_hash->root.u.def.value);
5447 #endif
5450 else
5451 #endif
5452 linker_section_ptr->offset = lsect->section->_raw_size;
5454 lsect->section->_raw_size += ARCH_SIZE / 8;
5456 #ifdef DEBUG
5457 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
5458 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
5459 #endif
5461 return true;
5465 #if ARCH_SIZE==64
5466 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
5467 #endif
5468 #if ARCH_SIZE==32
5469 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
5470 #endif
5472 /* Fill in the address for a pointer generated in alinker section. */
5474 bfd_vma
5475 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
5476 bfd *output_bfd;
5477 bfd *input_bfd;
5478 struct bfd_link_info *info;
5479 elf_linker_section_t *lsect;
5480 struct elf_link_hash_entry *h;
5481 bfd_vma relocation;
5482 const Elf_Internal_Rela *rel;
5483 int relative_reloc;
5485 elf_linker_section_pointers_t *linker_section_ptr;
5487 BFD_ASSERT (lsect != NULL);
5489 if (h != NULL) /* global symbol */
5491 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5492 rel->r_addend,
5493 lsect->which);
5495 BFD_ASSERT (linker_section_ptr != NULL);
5497 if (! elf_hash_table (info)->dynamic_sections_created
5498 || (info->shared
5499 && info->symbolic
5500 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
5502 /* This is actually a static link, or it is a
5503 -Bsymbolic link and the symbol is defined
5504 locally. We must initialize this entry in the
5505 global section.
5507 When doing a dynamic link, we create a .rela.<xxx>
5508 relocation entry to initialize the value. This
5509 is done in the finish_dynamic_symbol routine. */
5510 if (!linker_section_ptr->written_address_p)
5512 linker_section_ptr->written_address_p = true;
5513 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
5514 lsect->section->contents + linker_section_ptr->offset);
5518 else /* local symbol */
5520 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
5521 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
5522 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
5523 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
5524 rel->r_addend,
5525 lsect->which);
5527 BFD_ASSERT (linker_section_ptr != NULL);
5529 /* Write out pointer if it hasn't been rewritten out before */
5530 if (!linker_section_ptr->written_address_p)
5532 linker_section_ptr->written_address_p = true;
5533 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
5534 lsect->section->contents + linker_section_ptr->offset);
5536 if (info->shared)
5538 asection *srel = lsect->rel_section;
5539 Elf_Internal_Rela outrel;
5541 /* We need to generate a relative reloc for the dynamic linker. */
5542 if (!srel)
5543 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
5544 lsect->rel_name);
5546 BFD_ASSERT (srel != NULL);
5548 outrel.r_offset = (lsect->section->output_section->vma
5549 + lsect->section->output_offset
5550 + linker_section_ptr->offset);
5551 outrel.r_info = ELF_R_INFO (0, relative_reloc);
5552 outrel.r_addend = 0;
5553 elf_swap_reloca_out (output_bfd, &outrel,
5554 (((Elf_External_Rela *)
5555 lsect->section->contents)
5556 + lsect->section->reloc_count));
5557 ++lsect->section->reloc_count;
5562 relocation = (lsect->section->output_offset
5563 + linker_section_ptr->offset
5564 - lsect->hole_offset
5565 - lsect->sym_offset);
5567 #ifdef DEBUG
5568 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
5569 lsect->name, (long)relocation, (long)relocation);
5570 #endif
5572 /* Subtract out the addend, because it will get added back in by the normal
5573 processing. */
5574 return relocation - linker_section_ptr->addend;
5577 /* Garbage collect unused sections. */
5579 static boolean elf_gc_mark
5580 PARAMS ((struct bfd_link_info *info, asection *sec,
5581 asection * (*gc_mark_hook)
5582 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
5583 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
5585 static boolean elf_gc_sweep
5586 PARAMS ((struct bfd_link_info *info,
5587 boolean (*gc_sweep_hook)
5588 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
5589 const Elf_Internal_Rela *relocs))));
5591 static boolean elf_gc_sweep_symbol
5592 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
5594 static boolean elf_gc_allocate_got_offsets
5595 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
5597 static boolean elf_gc_propagate_vtable_entries_used
5598 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
5600 static boolean elf_gc_smash_unused_vtentry_relocs
5601 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
5603 /* The mark phase of garbage collection. For a given section, mark
5604 it, and all the sections which define symbols to which it refers. */
5606 static boolean
5607 elf_gc_mark (info, sec, gc_mark_hook)
5608 struct bfd_link_info *info;
5609 asection *sec;
5610 asection * (*gc_mark_hook)
5611 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
5612 struct elf_link_hash_entry *, Elf_Internal_Sym *));
5614 boolean ret = true;
5616 sec->gc_mark = 1;
5618 /* Look through the section relocs. */
5620 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
5622 Elf_Internal_Rela *relstart, *rel, *relend;
5623 Elf_Internal_Shdr *symtab_hdr;
5624 struct elf_link_hash_entry **sym_hashes;
5625 size_t nlocsyms;
5626 size_t extsymoff;
5627 Elf_External_Sym *locsyms, *freesyms = NULL;
5628 bfd *input_bfd = sec->owner;
5630 /* GCFIXME: how to arrange so that relocs and symbols are not
5631 reread continually? */
5633 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5634 sym_hashes = elf_sym_hashes (input_bfd);
5636 /* Read the local symbols. */
5637 if (elf_bad_symtab (input_bfd))
5639 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5640 extsymoff = 0;
5642 else
5643 extsymoff = nlocsyms = symtab_hdr->sh_info;
5644 if (symtab_hdr->contents)
5645 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
5646 else if (nlocsyms == 0)
5647 locsyms = NULL;
5648 else
5650 locsyms = freesyms =
5651 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
5652 if (freesyms == NULL
5653 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5654 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
5655 nlocsyms, input_bfd)
5656 != nlocsyms * sizeof (Elf_External_Sym)))
5658 ret = false;
5659 goto out1;
5663 /* Read the relocations. */
5664 relstart = (NAME(_bfd_elf,link_read_relocs)
5665 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
5666 info->keep_memory));
5667 if (relstart == NULL)
5669 ret = false;
5670 goto out1;
5672 relend = relstart + sec->reloc_count;
5674 for (rel = relstart; rel < relend; rel++)
5676 unsigned long r_symndx;
5677 asection *rsec;
5678 struct elf_link_hash_entry *h;
5679 Elf_Internal_Sym s;
5681 r_symndx = ELF_R_SYM (rel->r_info);
5682 if (r_symndx == 0)
5683 continue;
5685 if (elf_bad_symtab (sec->owner))
5687 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
5688 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
5689 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
5690 else
5692 h = sym_hashes[r_symndx - extsymoff];
5693 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
5696 else if (r_symndx >= nlocsyms)
5698 h = sym_hashes[r_symndx - extsymoff];
5699 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
5701 else
5703 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
5704 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
5707 if (rsec && !rsec->gc_mark)
5708 if (!elf_gc_mark (info, rsec, gc_mark_hook))
5710 ret = false;
5711 goto out2;
5715 out2:
5716 if (!info->keep_memory)
5717 free (relstart);
5718 out1:
5719 if (freesyms)
5720 free (freesyms);
5723 return ret;
5726 /* The sweep phase of garbage collection. Remove all garbage sections. */
5728 static boolean
5729 elf_gc_sweep (info, gc_sweep_hook)
5730 struct bfd_link_info *info;
5731 boolean (*gc_sweep_hook)
5732 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
5733 const Elf_Internal_Rela *relocs));
5735 bfd *sub;
5737 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
5739 asection *o;
5741 for (o = sub->sections; o != NULL; o = o->next)
5743 /* Keep special sections. Keep .debug sections. */
5744 if ((o->flags & SEC_LINKER_CREATED)
5745 || (o->flags & SEC_DEBUGGING))
5746 o->gc_mark = 1;
5748 if (o->gc_mark)
5749 continue;
5751 /* Skip sweeping sections already excluded. */
5752 if (o->flags & SEC_EXCLUDE)
5753 continue;
5755 /* Since this is early in the link process, it is simple
5756 to remove a section from the output. */
5757 o->flags |= SEC_EXCLUDE;
5759 /* But we also have to update some of the relocation
5760 info we collected before. */
5761 if (gc_sweep_hook
5762 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
5764 Elf_Internal_Rela *internal_relocs;
5765 boolean r;
5767 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5768 (o->owner, o, NULL, NULL, info->keep_memory));
5769 if (internal_relocs == NULL)
5770 return false;
5772 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
5774 if (!info->keep_memory)
5775 free (internal_relocs);
5777 if (!r)
5778 return false;
5783 /* Remove the symbols that were in the swept sections from the dynamic
5784 symbol table. GCFIXME: Anyone know how to get them out of the
5785 static symbol table as well? */
5787 int i = 0;
5789 elf_link_hash_traverse (elf_hash_table (info),
5790 elf_gc_sweep_symbol,
5791 (PTR) &i);
5793 elf_hash_table (info)->dynsymcount = i;
5796 return true;
5799 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
5801 static boolean
5802 elf_gc_sweep_symbol (h, idxptr)
5803 struct elf_link_hash_entry *h;
5804 PTR idxptr;
5806 int *idx = (int *) idxptr;
5808 if (h->dynindx != -1
5809 && ((h->root.type != bfd_link_hash_defined
5810 && h->root.type != bfd_link_hash_defweak)
5811 || h->root.u.def.section->gc_mark))
5812 h->dynindx = (*idx)++;
5814 return true;
5817 /* Propogate collected vtable information. This is called through
5818 elf_link_hash_traverse. */
5820 static boolean
5821 elf_gc_propagate_vtable_entries_used (h, okp)
5822 struct elf_link_hash_entry *h;
5823 PTR okp;
5825 /* Those that are not vtables. */
5826 if (h->vtable_parent == NULL)
5827 return true;
5829 /* Those vtables that do not have parents, we cannot merge. */
5830 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
5831 return true;
5833 /* If we've already been done, exit. */
5834 if (h->vtable_entries_used && h->vtable_entries_used[-1])
5835 return true;
5837 /* Make sure the parent's table is up to date. */
5838 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
5840 if (h->vtable_entries_used == NULL)
5842 /* None of this table's entries were referenced. Re-use the
5843 parent's table. */
5844 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
5845 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
5847 else
5849 size_t n;
5850 boolean *cu, *pu;
5852 /* Or the parent's entries into ours. */
5853 cu = h->vtable_entries_used;
5854 cu[-1] = true;
5855 pu = h->vtable_parent->vtable_entries_used;
5856 if (pu != NULL)
5858 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
5859 while (--n != 0)
5861 if (*pu) *cu = true;
5862 pu++, cu++;
5867 return true;
5870 static boolean
5871 elf_gc_smash_unused_vtentry_relocs (h, okp)
5872 struct elf_link_hash_entry *h;
5873 PTR okp;
5875 asection *sec;
5876 bfd_vma hstart, hend;
5877 Elf_Internal_Rela *relstart, *relend, *rel;
5879 /* Take care of both those symbols that do not describe vtables as
5880 well as those that are not loaded. */
5881 if (h->vtable_parent == NULL)
5882 return true;
5884 BFD_ASSERT (h->root.type == bfd_link_hash_defined
5885 || h->root.type == bfd_link_hash_defweak);
5887 sec = h->root.u.def.section;
5888 hstart = h->root.u.def.value;
5889 hend = hstart + h->size;
5891 relstart = (NAME(_bfd_elf,link_read_relocs)
5892 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
5893 if (!relstart)
5894 return *(boolean *)okp = false;
5895 relend = relstart + sec->reloc_count;
5897 for (rel = relstart; rel < relend; ++rel)
5898 if (rel->r_offset >= hstart && rel->r_offset < hend)
5900 /* If the entry is in use, do nothing. */
5901 if (h->vtable_entries_used
5902 && (rel->r_offset - hstart) < h->vtable_entries_size)
5904 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
5905 if (h->vtable_entries_used[entry])
5906 continue;
5908 /* Otherwise, kill it. */
5909 rel->r_offset = rel->r_info = rel->r_addend = 0;
5912 return true;
5915 /* Do mark and sweep of unused sections. */
5917 boolean
5918 elf_gc_sections (abfd, info)
5919 bfd *abfd;
5920 struct bfd_link_info *info;
5922 boolean ok = true;
5923 bfd *sub;
5924 asection * (*gc_mark_hook)
5925 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
5926 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
5928 if (!get_elf_backend_data (abfd)->can_gc_sections
5929 || info->relocateable
5930 || elf_hash_table (info)->dynamic_sections_created)
5931 return true;
5933 /* Apply transitive closure to the vtable entry usage info. */
5934 elf_link_hash_traverse (elf_hash_table (info),
5935 elf_gc_propagate_vtable_entries_used,
5936 (PTR) &ok);
5937 if (!ok)
5938 return false;
5940 /* Kill the vtable relocations that were not used. */
5941 elf_link_hash_traverse (elf_hash_table (info),
5942 elf_gc_smash_unused_vtentry_relocs,
5943 (PTR) &ok);
5944 if (!ok)
5945 return false;
5947 /* Grovel through relocs to find out who stays ... */
5949 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
5950 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
5952 asection *o;
5953 for (o = sub->sections; o != NULL; o = o->next)
5955 if (o->flags & SEC_KEEP)
5956 if (!elf_gc_mark (info, o, gc_mark_hook))
5957 return false;
5961 /* ... and mark SEC_EXCLUDE for those that go. */
5962 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
5963 return false;
5965 return true;
5968 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
5970 boolean
5971 elf_gc_record_vtinherit (abfd, sec, h, offset)
5972 bfd *abfd;
5973 asection *sec;
5974 struct elf_link_hash_entry *h;
5975 bfd_vma offset;
5977 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
5978 struct elf_link_hash_entry **search, *child;
5979 bfd_size_type extsymcount;
5981 /* The sh_info field of the symtab header tells us where the
5982 external symbols start. We don't care about the local symbols at
5983 this point. */
5984 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
5985 if (!elf_bad_symtab (abfd))
5986 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
5988 sym_hashes = elf_sym_hashes (abfd);
5989 sym_hashes_end = sym_hashes + extsymcount;
5991 /* Hunt down the child symbol, which is in this section at the same
5992 offset as the relocation. */
5993 for (search = sym_hashes; search != sym_hashes_end; ++search)
5995 if ((child = *search) != NULL
5996 && (child->root.type == bfd_link_hash_defined
5997 || child->root.type == bfd_link_hash_defweak)
5998 && child->root.u.def.section == sec
5999 && child->root.u.def.value == offset)
6000 goto win;
6003 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6004 bfd_get_filename (abfd), sec->name,
6005 (unsigned long)offset);
6006 bfd_set_error (bfd_error_invalid_operation);
6007 return false;
6009 win:
6010 if (!h)
6012 /* This *should* only be the absolute section. It could potentially
6013 be that someone has defined a non-global vtable though, which
6014 would be bad. It isn't worth paging in the local symbols to be
6015 sure though; that case should simply be handled by the assembler. */
6017 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6019 else
6020 child->vtable_parent = h;
6022 return true;
6025 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6027 boolean
6028 elf_gc_record_vtentry (abfd, sec, h, addend)
6029 bfd *abfd;
6030 asection *sec;
6031 struct elf_link_hash_entry *h;
6032 bfd_vma addend;
6034 if (addend >= h->vtable_entries_size)
6036 size_t size, bytes;
6037 boolean *ptr = h->vtable_entries_used;
6039 /* While the symbol is undefined, we have to be prepared to handle
6040 a zero size. */
6041 if (h->root.type == bfd_link_hash_undefined)
6042 size = addend;
6043 else
6045 size = h->size;
6046 if (size < addend)
6048 /* Oops! We've got a reference past the defined end of
6049 the table. This is probably a bug -- shall we warn? */
6050 size = addend;
6054 /* Allocate one extra entry for use as a "done" flag for the
6055 consolidation pass. */
6056 bytes = (size / FILE_ALIGN + 1) * sizeof(boolean);
6058 if (ptr)
6060 size_t oldbytes;
6062 ptr = realloc (ptr-1, bytes);
6063 if (ptr == NULL)
6064 return false;
6066 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof(boolean);
6067 memset (ptr + oldbytes, 0, bytes - oldbytes);
6069 else
6071 ptr = calloc (1, bytes);
6072 if (ptr == NULL)
6073 return false;
6076 /* And arrange for that done flag to be at index -1. */
6077 h->vtable_entries_used = ptr+1;
6078 h->vtable_entries_size = size;
6080 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6082 return true;
6085 /* And an accompanying bit to work out final got entry offsets once
6086 we're done. Should be called from final_link. */
6088 boolean
6089 elf_gc_common_finalize_got_offsets (abfd, info)
6090 bfd *abfd;
6091 struct bfd_link_info *info;
6093 bfd *i;
6094 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6095 bfd_vma gotoff;
6097 /* The GOT offset is relative to the .got section, but the GOT header is
6098 put into the .got.plt section, if the backend uses it. */
6099 if (bed->want_got_plt)
6100 gotoff = 0;
6101 else
6102 gotoff = bed->got_header_size;
6104 /* Do the local .got entries first. */
6105 for (i = info->input_bfds; i; i = i->link_next)
6107 bfd_signed_vma *local_got = elf_local_got_refcounts (i);
6108 bfd_size_type j, locsymcount;
6109 Elf_Internal_Shdr *symtab_hdr;
6111 if (!local_got)
6112 continue;
6114 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6115 if (elf_bad_symtab (i))
6116 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6117 else
6118 locsymcount = symtab_hdr->sh_info;
6120 for (j = 0; j < locsymcount; ++j)
6122 if (local_got[j] > 0)
6124 local_got[j] = gotoff;
6125 gotoff += ARCH_SIZE / 8;
6127 else
6128 local_got[j] = (bfd_vma) -1;
6132 /* Then the global .got and .plt entries. */
6133 elf_link_hash_traverse (elf_hash_table (info),
6134 elf_gc_allocate_got_offsets,
6135 (PTR) &gotoff);
6136 return true;
6139 /* We need a special top-level link routine to convert got reference counts
6140 to real got offsets. */
6142 static boolean
6143 elf_gc_allocate_got_offsets (h, offarg)
6144 struct elf_link_hash_entry *h;
6145 PTR offarg;
6147 bfd_vma *off = (bfd_vma *) offarg;
6149 if (h->got.refcount > 0)
6151 h->got.offset = off[0];
6152 off[0] += ARCH_SIZE / 8;
6154 else
6155 h->got.offset = (bfd_vma) -1;
6157 return true;
6160 /* Many folk need no more in the way of final link than this, once
6161 got entry reference counting is enabled. */
6163 boolean
6164 elf_gc_common_final_link (abfd, info)
6165 bfd *abfd;
6166 struct bfd_link_info *info;
6168 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6169 return false;
6171 /* Invoke the regular ELF backend linker to do all the work. */
6172 return elf_bfd_final_link (abfd, info);
6175 /* This function will be called though elf_link_hash_traverse to store
6176 all hash value of the exported symbols in an array. */
6178 static boolean
6179 elf_collect_hash_codes (h, data)
6180 struct elf_link_hash_entry *h;
6181 PTR data;
6183 unsigned long **valuep = (unsigned long **) data;
6184 const char *name;
6185 char *p;
6186 unsigned long ha;
6187 char *alc = NULL;
6189 /* Ignore indirect symbols. These are added by the versioning code. */
6190 if (h->dynindx == -1)
6191 return true;
6193 name = h->root.root.string;
6194 p = strchr (name, ELF_VER_CHR);
6195 if (p != NULL)
6197 alc = bfd_malloc (p - name + 1);
6198 memcpy (alc, name, p - name);
6199 alc[p - name] = '\0';
6200 name = alc;
6203 /* Compute the hash value. */
6204 ha = bfd_elf_hash (name);
6206 /* Store the found hash value in the array given as the argument. */
6207 *(*valuep)++ = ha;
6209 /* And store it in the struct so that we can put it in the hash table
6210 later. */
6211 h->elf_hash_value = ha;
6213 if (alc != NULL)
6214 free (alc);
6216 return true;