2000-07-19 H.J. Lu <hjl@gnu.org>
[binutils.git] / bfd / elflink.h
blob7fa35a936ce0eee2f13a93babdf84117ddbe89bc
1 /* ELF linker support.
2 Copyright 1995, 1996, 1997, 1998, 1999, 2000 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_collect_hash_codes
52 PARAMS ((struct elf_link_hash_entry *, PTR));
53 static boolean elf_link_read_relocs_from_section
54 PARAMS ((bfd *, Elf_Internal_Shdr *, PTR, Elf_Internal_Rela *));
55 static void elf_link_output_relocs
56 PARAMS ((bfd *, asection *, Elf_Internal_Shdr *, Elf_Internal_Rela *));
57 static boolean elf_link_size_reloc_section
58 PARAMS ((bfd *, Elf_Internal_Shdr *, asection *));
59 static void elf_link_adjust_relocs
60 PARAMS ((bfd *, Elf_Internal_Shdr *, unsigned int,
61 struct elf_link_hash_entry **));
63 /* Given an ELF BFD, add symbols to the global hash table as
64 appropriate. */
66 boolean
67 elf_bfd_link_add_symbols (abfd, info)
68 bfd *abfd;
69 struct bfd_link_info *info;
71 switch (bfd_get_format (abfd))
73 case bfd_object:
74 return elf_link_add_object_symbols (abfd, info);
75 case bfd_archive:
76 return elf_link_add_archive_symbols (abfd, info);
77 default:
78 bfd_set_error (bfd_error_wrong_format);
79 return false;
83 /* Return true iff this is a non-common definition of a symbol. */
84 static boolean
85 is_global_symbol_definition (abfd, sym)
86 bfd * abfd ATTRIBUTE_UNUSED;
87 Elf_Internal_Sym * sym;
89 /* Local symbols do not count, but target specific ones might. */
90 if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
91 && ELF_ST_BIND (sym->st_info) < STB_LOOS)
92 return false;
94 /* If the section is undefined, then so is the symbol. */
95 if (sym->st_shndx == SHN_UNDEF)
96 return false;
98 /* If the symbol is defined in the common section, then
99 it is a common definition and so does not count. */
100 if (sym->st_shndx == SHN_COMMON)
101 return false;
103 /* If the symbol is in a target specific section then we
104 must rely upon the backend to tell us what it is. */
105 if (sym->st_shndx >= SHN_LORESERVE && sym->st_shndx < SHN_ABS)
106 /* FIXME - this function is not coded yet:
108 return _bfd_is_global_symbol_definition (abfd, sym);
110 Instead for now assume that the definition is not global,
111 Even if this is wrong, at least the linker will behave
112 in the same way that it used to do. */
113 return false;
115 return true;
119 /* Search the symbol table of the archive element of the archive ABFD
120 whoes archove map contains a mention of SYMDEF, and determine if
121 the symbol is defined in this element. */
122 static boolean
123 elf_link_is_defined_archive_symbol (abfd, symdef)
124 bfd * abfd;
125 carsym * symdef;
127 Elf_Internal_Shdr * hdr;
128 Elf_External_Sym * esym;
129 Elf_External_Sym * esymend;
130 Elf_External_Sym * buf = NULL;
131 size_t symcount;
132 size_t extsymcount;
133 size_t extsymoff;
134 boolean result = false;
136 abfd = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
137 if (abfd == (bfd *) NULL)
138 return false;
140 if (! bfd_check_format (abfd, bfd_object))
141 return false;
143 /* If we have already included the element containing this symbol in the
144 link then we do not need to include it again. Just claim that any symbol
145 it contains is not a definition, so that our caller will not decide to
146 (re)include this element. */
147 if (abfd->archive_pass)
148 return false;
150 /* Select the appropriate symbol table. */
151 if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
152 hdr = &elf_tdata (abfd)->symtab_hdr;
153 else
154 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
156 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
158 /* The sh_info field of the symtab header tells us where the
159 external symbols start. We don't care about the local symbols. */
160 if (elf_bad_symtab (abfd))
162 extsymcount = symcount;
163 extsymoff = 0;
165 else
167 extsymcount = symcount - hdr->sh_info;
168 extsymoff = hdr->sh_info;
171 buf = ((Elf_External_Sym *)
172 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
173 if (buf == NULL && extsymcount != 0)
174 return false;
176 /* Read in the symbol table.
177 FIXME: This ought to be cached somewhere. */
178 if (bfd_seek (abfd,
179 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
180 SEEK_SET) != 0
181 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
182 != extsymcount * sizeof (Elf_External_Sym)))
184 free (buf);
185 return false;
188 /* Scan the symbol table looking for SYMDEF. */
189 esymend = buf + extsymcount;
190 for (esym = buf;
191 esym < esymend;
192 esym++)
194 Elf_Internal_Sym sym;
195 const char * name;
197 elf_swap_symbol_in (abfd, esym, & sym);
199 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
200 if (name == (const char *) NULL)
201 break;
203 if (strcmp (name, symdef->name) == 0)
205 result = is_global_symbol_definition (abfd, & sym);
206 break;
210 free (buf);
212 return result;
216 /* Add symbols from an ELF archive file to the linker hash table. We
217 don't use _bfd_generic_link_add_archive_symbols because of a
218 problem which arises on UnixWare. The UnixWare libc.so is an
219 archive which includes an entry libc.so.1 which defines a bunch of
220 symbols. The libc.so archive also includes a number of other
221 object files, which also define symbols, some of which are the same
222 as those defined in libc.so.1. Correct linking requires that we
223 consider each object file in turn, and include it if it defines any
224 symbols we need. _bfd_generic_link_add_archive_symbols does not do
225 this; it looks through the list of undefined symbols, and includes
226 any object file which defines them. When this algorithm is used on
227 UnixWare, it winds up pulling in libc.so.1 early and defining a
228 bunch of symbols. This means that some of the other objects in the
229 archive are not included in the link, which is incorrect since they
230 precede libc.so.1 in the archive.
232 Fortunately, ELF archive handling is simpler than that done by
233 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
234 oddities. In ELF, if we find a symbol in the archive map, and the
235 symbol is currently undefined, we know that we must pull in that
236 object file.
238 Unfortunately, we do have to make multiple passes over the symbol
239 table until nothing further is resolved. */
241 static boolean
242 elf_link_add_archive_symbols (abfd, info)
243 bfd *abfd;
244 struct bfd_link_info *info;
246 symindex c;
247 boolean *defined = NULL;
248 boolean *included = NULL;
249 carsym *symdefs;
250 boolean loop;
252 if (! bfd_has_map (abfd))
254 /* An empty archive is a special case. */
255 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
256 return true;
257 bfd_set_error (bfd_error_no_armap);
258 return false;
261 /* Keep track of all symbols we know to be already defined, and all
262 files we know to be already included. This is to speed up the
263 second and subsequent passes. */
264 c = bfd_ardata (abfd)->symdef_count;
265 if (c == 0)
266 return true;
267 defined = (boolean *) bfd_malloc (c * sizeof (boolean));
268 included = (boolean *) bfd_malloc (c * sizeof (boolean));
269 if (defined == (boolean *) NULL || included == (boolean *) NULL)
270 goto error_return;
271 memset (defined, 0, c * sizeof (boolean));
272 memset (included, 0, c * sizeof (boolean));
274 symdefs = bfd_ardata (abfd)->symdefs;
278 file_ptr last;
279 symindex i;
280 carsym *symdef;
281 carsym *symdefend;
283 loop = false;
284 last = -1;
286 symdef = symdefs;
287 symdefend = symdef + c;
288 for (i = 0; symdef < symdefend; symdef++, i++)
290 struct elf_link_hash_entry *h;
291 bfd *element;
292 struct bfd_link_hash_entry *undefs_tail;
293 symindex mark;
295 if (defined[i] || included[i])
296 continue;
297 if (symdef->file_offset == last)
299 included[i] = true;
300 continue;
303 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
304 false, false, false);
306 if (h == NULL)
308 char *p, *copy;
310 /* If this is a default version (the name contains @@),
311 look up the symbol again without the version. The
312 effect is that references to the symbol without the
313 version will be matched by the default symbol in the
314 archive. */
316 p = strchr (symdef->name, ELF_VER_CHR);
317 if (p == NULL || p[1] != ELF_VER_CHR)
318 continue;
320 copy = bfd_alloc (abfd, p - symdef->name + 1);
321 if (copy == NULL)
322 goto error_return;
323 memcpy (copy, symdef->name, p - symdef->name);
324 copy[p - symdef->name] = '\0';
326 h = elf_link_hash_lookup (elf_hash_table (info), copy,
327 false, false, false);
329 bfd_release (abfd, copy);
332 if (h == NULL)
333 continue;
335 if (h->root.type == bfd_link_hash_common)
337 /* We currently have a common symbol. The archive map contains
338 a reference to this symbol, so we may want to include it. We
339 only want to include it however, if this archive element
340 contains a definition of the symbol, not just another common
341 declaration of it.
343 Unfortunately some archivers (including GNU ar) will put
344 declarations of common symbols into their archive maps, as
345 well as real definitions, so we cannot just go by the archive
346 map alone. Instead we must read in the element's symbol
347 table and check that to see what kind of symbol definition
348 this is. */
349 if (! elf_link_is_defined_archive_symbol (abfd, symdef))
350 continue;
352 else if (h->root.type != bfd_link_hash_undefined)
354 if (h->root.type != bfd_link_hash_undefweak)
355 defined[i] = true;
356 continue;
359 /* We need to include this archive member. */
360 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
361 if (element == (bfd *) NULL)
362 goto error_return;
364 if (! bfd_check_format (element, bfd_object))
365 goto error_return;
367 /* Doublecheck that we have not included this object
368 already--it should be impossible, but there may be
369 something wrong with the archive. */
370 if (element->archive_pass != 0)
372 bfd_set_error (bfd_error_bad_value);
373 goto error_return;
375 element->archive_pass = 1;
377 undefs_tail = info->hash->undefs_tail;
379 if (! (*info->callbacks->add_archive_element) (info, element,
380 symdef->name))
381 goto error_return;
382 if (! elf_link_add_object_symbols (element, info))
383 goto error_return;
385 /* If there are any new undefined symbols, we need to make
386 another pass through the archive in order to see whether
387 they can be defined. FIXME: This isn't perfect, because
388 common symbols wind up on undefs_tail and because an
389 undefined symbol which is defined later on in this pass
390 does not require another pass. This isn't a bug, but it
391 does make the code less efficient than it could be. */
392 if (undefs_tail != info->hash->undefs_tail)
393 loop = true;
395 /* Look backward to mark all symbols from this object file
396 which we have already seen in this pass. */
397 mark = i;
400 included[mark] = true;
401 if (mark == 0)
402 break;
403 --mark;
405 while (symdefs[mark].file_offset == symdef->file_offset);
407 /* We mark subsequent symbols from this object file as we go
408 on through the loop. */
409 last = symdef->file_offset;
412 while (loop);
414 free (defined);
415 free (included);
417 return true;
419 error_return:
420 if (defined != (boolean *) NULL)
421 free (defined);
422 if (included != (boolean *) NULL)
423 free (included);
424 return false;
427 /* This function is called when we want to define a new symbol. It
428 handles the various cases which arise when we find a definition in
429 a dynamic object, or when there is already a definition in a
430 dynamic object. The new symbol is described by NAME, SYM, PSEC,
431 and PVALUE. We set SYM_HASH to the hash table entry. We set
432 OVERRIDE if the old symbol is overriding a new definition. We set
433 TYPE_CHANGE_OK if it is OK for the type to change. We set
434 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
435 change, we mean that we shouldn't warn if the type or size does
436 change. */
438 static boolean
439 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
440 override, type_change_ok, size_change_ok)
441 bfd *abfd;
442 struct bfd_link_info *info;
443 const char *name;
444 Elf_Internal_Sym *sym;
445 asection **psec;
446 bfd_vma *pvalue;
447 struct elf_link_hash_entry **sym_hash;
448 boolean *override;
449 boolean *type_change_ok;
450 boolean *size_change_ok;
452 asection *sec;
453 struct elf_link_hash_entry *h;
454 int bind;
455 bfd *oldbfd;
456 boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
458 *override = false;
460 sec = *psec;
461 bind = ELF_ST_BIND (sym->st_info);
463 if (! bfd_is_und_section (sec))
464 h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
465 else
466 h = ((struct elf_link_hash_entry *)
467 bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
468 if (h == NULL)
469 return false;
470 *sym_hash = h;
472 /* This code is for coping with dynamic objects, and is only useful
473 if we are doing an ELF link. */
474 if (info->hash->creator != abfd->xvec)
475 return true;
477 /* For merging, we only care about real symbols. */
479 while (h->root.type == bfd_link_hash_indirect
480 || h->root.type == bfd_link_hash_warning)
481 h = (struct elf_link_hash_entry *) h->root.u.i.link;
483 /* If we just created the symbol, mark it as being an ELF symbol.
484 Other than that, there is nothing to do--there is no merge issue
485 with a newly defined symbol--so we just return. */
487 if (h->root.type == bfd_link_hash_new)
489 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
490 return true;
493 /* OLDBFD is a BFD associated with the existing symbol. */
495 switch (h->root.type)
497 default:
498 oldbfd = NULL;
499 break;
501 case bfd_link_hash_undefined:
502 case bfd_link_hash_undefweak:
503 oldbfd = h->root.u.undef.abfd;
504 break;
506 case bfd_link_hash_defined:
507 case bfd_link_hash_defweak:
508 oldbfd = h->root.u.def.section->owner;
509 break;
511 case bfd_link_hash_common:
512 oldbfd = h->root.u.c.p->section->owner;
513 break;
516 /* In cases involving weak versioned symbols, we may wind up trying
517 to merge a symbol with itself. Catch that here, to avoid the
518 confusion that results if we try to override a symbol with
519 itself. The additional tests catch cases like
520 _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
521 dynamic object, which we do want to handle here. */
522 if (abfd == oldbfd
523 && ((abfd->flags & DYNAMIC) == 0
524 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))
525 return true;
527 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
528 respectively, is from a dynamic object. */
530 if ((abfd->flags & DYNAMIC) != 0)
531 newdyn = true;
532 else
533 newdyn = false;
535 if (oldbfd != NULL)
536 olddyn = (oldbfd->flags & DYNAMIC) != 0;
537 else
539 asection *hsec;
541 /* This code handles the special SHN_MIPS_{TEXT,DATA} section
542 indices used by MIPS ELF. */
543 switch (h->root.type)
545 default:
546 hsec = NULL;
547 break;
549 case bfd_link_hash_defined:
550 case bfd_link_hash_defweak:
551 hsec = h->root.u.def.section;
552 break;
554 case bfd_link_hash_common:
555 hsec = h->root.u.c.p->section;
556 break;
559 if (hsec == NULL)
560 olddyn = false;
561 else
562 olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0;
565 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
566 respectively, appear to be a definition rather than reference. */
568 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
569 newdef = false;
570 else
571 newdef = true;
573 if (h->root.type == bfd_link_hash_undefined
574 || h->root.type == bfd_link_hash_undefweak
575 || h->root.type == bfd_link_hash_common)
576 olddef = false;
577 else
578 olddef = true;
580 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
581 symbol, respectively, appears to be a common symbol in a dynamic
582 object. If a symbol appears in an uninitialized section, and is
583 not weak, and is not a function, then it may be a common symbol
584 which was resolved when the dynamic object was created. We want
585 to treat such symbols specially, because they raise special
586 considerations when setting the symbol size: if the symbol
587 appears as a common symbol in a regular object, and the size in
588 the regular object is larger, we must make sure that we use the
589 larger size. This problematic case can always be avoided in C,
590 but it must be handled correctly when using Fortran shared
591 libraries.
593 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
594 likewise for OLDDYNCOMMON and OLDDEF.
596 Note that this test is just a heuristic, and that it is quite
597 possible to have an uninitialized symbol in a shared object which
598 is really a definition, rather than a common symbol. This could
599 lead to some minor confusion when the symbol really is a common
600 symbol in some regular object. However, I think it will be
601 harmless. */
603 if (newdyn
604 && newdef
605 && (sec->flags & SEC_ALLOC) != 0
606 && (sec->flags & SEC_LOAD) == 0
607 && sym->st_size > 0
608 && bind != STB_WEAK
609 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
610 newdyncommon = true;
611 else
612 newdyncommon = false;
614 if (olddyn
615 && olddef
616 && h->root.type == bfd_link_hash_defined
617 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
618 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
619 && (h->root.u.def.section->flags & SEC_LOAD) == 0
620 && h->size > 0
621 && h->type != STT_FUNC)
622 olddyncommon = true;
623 else
624 olddyncommon = false;
626 /* It's OK to change the type if either the existing symbol or the
627 new symbol is weak. */
629 if (h->root.type == bfd_link_hash_defweak
630 || h->root.type == bfd_link_hash_undefweak
631 || bind == STB_WEAK)
632 *type_change_ok = true;
634 /* It's OK to change the size if either the existing symbol or the
635 new symbol is weak, or if the old symbol is undefined. */
637 if (*type_change_ok
638 || h->root.type == bfd_link_hash_undefined)
639 *size_change_ok = true;
641 /* If both the old and the new symbols look like common symbols in a
642 dynamic object, set the size of the symbol to the larger of the
643 two. */
645 if (olddyncommon
646 && newdyncommon
647 && sym->st_size != h->size)
649 /* Since we think we have two common symbols, issue a multiple
650 common warning if desired. Note that we only warn if the
651 size is different. If the size is the same, we simply let
652 the old symbol override the new one as normally happens with
653 symbols defined in dynamic objects. */
655 if (! ((*info->callbacks->multiple_common)
656 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
657 h->size, abfd, bfd_link_hash_common, sym->st_size)))
658 return false;
660 if (sym->st_size > h->size)
661 h->size = sym->st_size;
663 *size_change_ok = true;
666 /* If we are looking at a dynamic object, and we have found a
667 definition, we need to see if the symbol was already defined by
668 some other object. If so, we want to use the existing
669 definition, and we do not want to report a multiple symbol
670 definition error; we do this by clobbering *PSEC to be
671 bfd_und_section_ptr.
673 We treat a common symbol as a definition if the symbol in the
674 shared library is a function, since common symbols always
675 represent variables; this can cause confusion in principle, but
676 any such confusion would seem to indicate an erroneous program or
677 shared library. We also permit a common symbol in a regular
678 object to override a weak symbol in a shared object.
680 We prefer a non-weak definition in a shared library to a weak
681 definition in the executable. */
683 if (newdyn
684 && newdef
685 && (olddef
686 || (h->root.type == bfd_link_hash_common
687 && (bind == STB_WEAK
688 || ELF_ST_TYPE (sym->st_info) == STT_FUNC)))
689 && (h->root.type != bfd_link_hash_defweak
690 || bind == STB_WEAK))
692 *override = true;
693 newdef = false;
694 newdyncommon = false;
696 *psec = sec = bfd_und_section_ptr;
697 *size_change_ok = true;
699 /* If we get here when the old symbol is a common symbol, then
700 we are explicitly letting it override a weak symbol or
701 function in a dynamic object, and we don't want to warn about
702 a type change. If the old symbol is a defined symbol, a type
703 change warning may still be appropriate. */
705 if (h->root.type == bfd_link_hash_common)
706 *type_change_ok = true;
709 /* Handle the special case of an old common symbol merging with a
710 new symbol which looks like a common symbol in a shared object.
711 We change *PSEC and *PVALUE to make the new symbol look like a
712 common symbol, and let _bfd_generic_link_add_one_symbol will do
713 the right thing. */
715 if (newdyncommon
716 && h->root.type == bfd_link_hash_common)
718 *override = true;
719 newdef = false;
720 newdyncommon = false;
721 *pvalue = sym->st_size;
722 *psec = sec = bfd_com_section_ptr;
723 *size_change_ok = true;
726 /* If the old symbol is from a dynamic object, and the new symbol is
727 a definition which is not from a dynamic object, then the new
728 symbol overrides the old symbol. Symbols from regular files
729 always take precedence over symbols from dynamic objects, even if
730 they are defined after the dynamic object in the link.
732 As above, we again permit a common symbol in a regular object to
733 override a definition in a shared object if the shared object
734 symbol is a function or is weak.
736 As above, we permit a non-weak definition in a shared object to
737 override a weak definition in a regular object. */
739 if (! newdyn
740 && (newdef
741 || (bfd_is_com_section (sec)
742 && (h->root.type == bfd_link_hash_defweak
743 || h->type == STT_FUNC)))
744 && olddyn
745 && olddef
746 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
747 && (bind != STB_WEAK
748 || h->root.type == bfd_link_hash_defweak))
750 /* Change the hash table entry to undefined, and let
751 _bfd_generic_link_add_one_symbol do the right thing with the
752 new definition. */
754 h->root.type = bfd_link_hash_undefined;
755 h->root.u.undef.abfd = h->root.u.def.section->owner;
756 *size_change_ok = true;
758 olddef = false;
759 olddyncommon = false;
761 /* We again permit a type change when a common symbol may be
762 overriding a function. */
764 if (bfd_is_com_section (sec))
765 *type_change_ok = true;
767 /* This union may have been set to be non-NULL when this symbol
768 was seen in a dynamic object. We must force the union to be
769 NULL, so that it is correct for a regular symbol. */
771 h->verinfo.vertree = NULL;
773 /* In this special case, if H is the target of an indirection,
774 we want the caller to frob with H rather than with the
775 indirect symbol. That will permit the caller to redefine the
776 target of the indirection, rather than the indirect symbol
777 itself. FIXME: This will break the -y option if we store a
778 symbol with a different name. */
779 *sym_hash = h;
782 /* Handle the special case of a new common symbol merging with an
783 old symbol that looks like it might be a common symbol defined in
784 a shared object. Note that we have already handled the case in
785 which a new common symbol should simply override the definition
786 in the shared library. */
788 if (! newdyn
789 && bfd_is_com_section (sec)
790 && olddyncommon)
792 /* It would be best if we could set the hash table entry to a
793 common symbol, but we don't know what to use for the section
794 or the alignment. */
795 if (! ((*info->callbacks->multiple_common)
796 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
797 h->size, abfd, bfd_link_hash_common, sym->st_size)))
798 return false;
800 /* If the predumed common symbol in the dynamic object is
801 larger, pretend that the new symbol has its size. */
803 if (h->size > *pvalue)
804 *pvalue = h->size;
806 /* FIXME: We no longer know the alignment required by the symbol
807 in the dynamic object, so we just wind up using the one from
808 the regular object. */
810 olddef = false;
811 olddyncommon = false;
813 h->root.type = bfd_link_hash_undefined;
814 h->root.u.undef.abfd = h->root.u.def.section->owner;
816 *size_change_ok = true;
817 *type_change_ok = true;
819 h->verinfo.vertree = NULL;
822 /* Handle the special case of a weak definition in a regular object
823 followed by a non-weak definition in a shared object. In this
824 case, we prefer the definition in the shared object. */
825 if (olddef
826 && h->root.type == bfd_link_hash_defweak
827 && newdef
828 && newdyn
829 && bind != STB_WEAK)
831 /* To make this work we have to frob the flags so that the rest
832 of the code does not think we are using the regular
833 definition. */
834 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
835 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
836 else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
837 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
838 h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR
839 | ELF_LINK_HASH_DEF_DYNAMIC);
841 /* If H is the target of an indirection, we want the caller to
842 use H rather than the indirect symbol. Otherwise if we are
843 defining a new indirect symbol we will wind up attaching it
844 to the entry we are overriding. */
845 *sym_hash = h;
848 /* Handle the special case of a non-weak definition in a shared
849 object followed by a weak definition in a regular object. In
850 this case we prefer to definition in the shared object. To make
851 this work we have to tell the caller to not treat the new symbol
852 as a definition. */
853 if (olddef
854 && olddyn
855 && h->root.type != bfd_link_hash_defweak
856 && newdef
857 && ! newdyn
858 && bind == STB_WEAK)
859 *override = true;
861 return true;
864 /* Add symbols from an ELF object file to the linker hash table. */
866 static boolean
867 elf_link_add_object_symbols (abfd, info)
868 bfd *abfd;
869 struct bfd_link_info *info;
871 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
872 const Elf_Internal_Sym *,
873 const char **, flagword *,
874 asection **, bfd_vma *));
875 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
876 asection *, const Elf_Internal_Rela *));
877 boolean collect;
878 Elf_Internal_Shdr *hdr;
879 size_t symcount;
880 size_t extsymcount;
881 size_t extsymoff;
882 Elf_External_Sym *buf = NULL;
883 struct elf_link_hash_entry **sym_hash;
884 boolean dynamic;
885 bfd_byte *dynver = NULL;
886 Elf_External_Versym *extversym = NULL;
887 Elf_External_Versym *ever;
888 Elf_External_Dyn *dynbuf = NULL;
889 struct elf_link_hash_entry *weaks;
890 Elf_External_Sym *esym;
891 Elf_External_Sym *esymend;
892 struct elf_backend_data *bed;
893 boolean dt_needed;
895 bed = get_elf_backend_data (abfd);
896 add_symbol_hook = bed->elf_add_symbol_hook;
897 collect = bed->collect;
899 if ((abfd->flags & DYNAMIC) == 0)
900 dynamic = false;
901 else
903 dynamic = true;
905 /* You can't use -r against a dynamic object. Also, there's no
906 hope of using a dynamic object which does not exactly match
907 the format of the output file. */
908 if (info->relocateable || info->hash->creator != abfd->xvec)
910 bfd_set_error (bfd_error_invalid_operation);
911 goto error_return;
915 /* As a GNU extension, any input sections which are named
916 .gnu.warning.SYMBOL are treated as warning symbols for the given
917 symbol. This differs from .gnu.warning sections, which generate
918 warnings when they are included in an output file. */
919 if (! info->shared)
921 asection *s;
923 for (s = abfd->sections; s != NULL; s = s->next)
925 const char *name;
927 name = bfd_get_section_name (abfd, s);
928 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
930 char *msg;
931 bfd_size_type sz;
933 name += sizeof ".gnu.warning." - 1;
935 /* If this is a shared object, then look up the symbol
936 in the hash table. If it is there, and it is already
937 been defined, then we will not be using the entry
938 from this shared object, so we don't need to warn.
939 FIXME: If we see the definition in a regular object
940 later on, we will warn, but we shouldn't. The only
941 fix is to keep track of what warnings we are supposed
942 to emit, and then handle them all at the end of the
943 link. */
944 if (dynamic && abfd->xvec == info->hash->creator)
946 struct elf_link_hash_entry *h;
948 h = elf_link_hash_lookup (elf_hash_table (info), name,
949 false, false, true);
951 /* FIXME: What about bfd_link_hash_common? */
952 if (h != NULL
953 && (h->root.type == bfd_link_hash_defined
954 || h->root.type == bfd_link_hash_defweak))
956 /* We don't want to issue this warning. Clobber
957 the section size so that the warning does not
958 get copied into the output file. */
959 s->_raw_size = 0;
960 continue;
964 sz = bfd_section_size (abfd, s);
965 msg = (char *) bfd_alloc (abfd, sz + 1);
966 if (msg == NULL)
967 goto error_return;
969 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
970 goto error_return;
972 msg[sz] = '\0';
974 if (! (_bfd_generic_link_add_one_symbol
975 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
976 false, collect, (struct bfd_link_hash_entry **) NULL)))
977 goto error_return;
979 if (! info->relocateable)
981 /* Clobber the section size so that the warning does
982 not get copied into the output file. */
983 s->_raw_size = 0;
989 /* If this is a dynamic object, we always link against the .dynsym
990 symbol table, not the .symtab symbol table. The dynamic linker
991 will only see the .dynsym symbol table, so there is no reason to
992 look at .symtab for a dynamic object. */
994 if (! dynamic || elf_dynsymtab (abfd) == 0)
995 hdr = &elf_tdata (abfd)->symtab_hdr;
996 else
997 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
999 if (dynamic)
1001 /* Read in any version definitions. */
1003 if (! _bfd_elf_slurp_version_tables (abfd))
1004 goto error_return;
1006 /* Read in the symbol versions, but don't bother to convert them
1007 to internal format. */
1008 if (elf_dynversym (abfd) != 0)
1010 Elf_Internal_Shdr *versymhdr;
1012 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
1013 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
1014 if (extversym == NULL)
1015 goto error_return;
1016 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
1017 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
1018 != versymhdr->sh_size))
1019 goto error_return;
1023 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
1025 /* The sh_info field of the symtab header tells us where the
1026 external symbols start. We don't care about the local symbols at
1027 this point. */
1028 if (elf_bad_symtab (abfd))
1030 extsymcount = symcount;
1031 extsymoff = 0;
1033 else
1035 extsymcount = symcount - hdr->sh_info;
1036 extsymoff = hdr->sh_info;
1039 buf = ((Elf_External_Sym *)
1040 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
1041 if (buf == NULL && extsymcount != 0)
1042 goto error_return;
1044 /* We store a pointer to the hash table entry for each external
1045 symbol. */
1046 sym_hash = ((struct elf_link_hash_entry **)
1047 bfd_alloc (abfd,
1048 extsymcount * sizeof (struct elf_link_hash_entry *)));
1049 if (sym_hash == NULL)
1050 goto error_return;
1051 elf_sym_hashes (abfd) = sym_hash;
1053 dt_needed = false;
1055 if (! dynamic)
1057 /* If we are creating a shared library, create all the dynamic
1058 sections immediately. We need to attach them to something,
1059 so we attach them to this BFD, provided it is the right
1060 format. FIXME: If there are no input BFD's of the same
1061 format as the output, we can't make a shared library. */
1062 if (info->shared
1063 && ! elf_hash_table (info)->dynamic_sections_created
1064 && abfd->xvec == info->hash->creator)
1066 if (! elf_link_create_dynamic_sections (abfd, info))
1067 goto error_return;
1070 else
1072 asection *s;
1073 boolean add_needed;
1074 const char *name;
1075 bfd_size_type oldsize;
1076 bfd_size_type strindex;
1078 /* Find the name to use in a DT_NEEDED entry that refers to this
1079 object. If the object has a DT_SONAME entry, we use it.
1080 Otherwise, if the generic linker stuck something in
1081 elf_dt_name, we use that. Otherwise, we just use the file
1082 name. If the generic linker put a null string into
1083 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
1084 there is a DT_SONAME entry. */
1085 add_needed = true;
1086 name = bfd_get_filename (abfd);
1087 if (elf_dt_name (abfd) != NULL)
1089 name = elf_dt_name (abfd);
1090 if (*name == '\0')
1092 if (elf_dt_soname (abfd) != NULL)
1093 dt_needed = true;
1095 add_needed = false;
1098 s = bfd_get_section_by_name (abfd, ".dynamic");
1099 if (s != NULL)
1101 Elf_External_Dyn *extdyn;
1102 Elf_External_Dyn *extdynend;
1103 int elfsec;
1104 unsigned long link;
1106 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
1107 if (dynbuf == NULL)
1108 goto error_return;
1110 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
1111 (file_ptr) 0, s->_raw_size))
1112 goto error_return;
1114 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1115 if (elfsec == -1)
1116 goto error_return;
1117 link = elf_elfsections (abfd)[elfsec]->sh_link;
1120 /* The shared libraries distributed with hpux11 have a bogus
1121 sh_link field for the ".dynamic" section. This code detects
1122 when LINK refers to a section that is not a string table and
1123 tries to find the string table for the ".dynsym" section
1124 instead. */
1125 Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[link];
1126 if (hdr->sh_type != SHT_STRTAB)
1128 asection *s = bfd_get_section_by_name (abfd, ".dynsym");
1129 int elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1130 if (elfsec == -1)
1131 goto error_return;
1132 link = elf_elfsections (abfd)[elfsec]->sh_link;
1136 extdyn = dynbuf;
1137 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
1138 for (; extdyn < extdynend; extdyn++)
1140 Elf_Internal_Dyn dyn;
1142 elf_swap_dyn_in (abfd, extdyn, &dyn);
1143 if (dyn.d_tag == DT_SONAME)
1145 name = bfd_elf_string_from_elf_section (abfd, link,
1146 dyn.d_un.d_val);
1147 if (name == NULL)
1148 goto error_return;
1150 if (dyn.d_tag == DT_NEEDED)
1152 struct bfd_link_needed_list *n, **pn;
1153 char *fnm, *anm;
1155 n = ((struct bfd_link_needed_list *)
1156 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1157 fnm = bfd_elf_string_from_elf_section (abfd, link,
1158 dyn.d_un.d_val);
1159 if (n == NULL || fnm == NULL)
1160 goto error_return;
1161 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1162 if (anm == NULL)
1163 goto error_return;
1164 strcpy (anm, fnm);
1165 n->name = anm;
1166 n->by = abfd;
1167 n->next = NULL;
1168 for (pn = &elf_hash_table (info)->needed;
1169 *pn != NULL;
1170 pn = &(*pn)->next)
1172 *pn = n;
1176 free (dynbuf);
1177 dynbuf = NULL;
1180 /* We do not want to include any of the sections in a dynamic
1181 object in the output file. We hack by simply clobbering the
1182 list of sections in the BFD. This could be handled more
1183 cleanly by, say, a new section flag; the existing
1184 SEC_NEVER_LOAD flag is not the one we want, because that one
1185 still implies that the section takes up space in the output
1186 file. */
1187 abfd->sections = NULL;
1188 abfd->section_count = 0;
1190 /* If this is the first dynamic object found in the link, create
1191 the special sections required for dynamic linking. */
1192 if (! elf_hash_table (info)->dynamic_sections_created)
1194 if (! elf_link_create_dynamic_sections (abfd, info))
1195 goto error_return;
1198 if (add_needed)
1200 /* Add a DT_NEEDED entry for this dynamic object. */
1201 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1202 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
1203 true, false);
1204 if (strindex == (bfd_size_type) -1)
1205 goto error_return;
1207 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1209 asection *sdyn;
1210 Elf_External_Dyn *dyncon, *dynconend;
1212 /* The hash table size did not change, which means that
1213 the dynamic object name was already entered. If we
1214 have already included this dynamic object in the
1215 link, just ignore it. There is no reason to include
1216 a particular dynamic object more than once. */
1217 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1218 ".dynamic");
1219 BFD_ASSERT (sdyn != NULL);
1221 dyncon = (Elf_External_Dyn *) sdyn->contents;
1222 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1223 sdyn->_raw_size);
1224 for (; dyncon < dynconend; dyncon++)
1226 Elf_Internal_Dyn dyn;
1228 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
1229 &dyn);
1230 if (dyn.d_tag == DT_NEEDED
1231 && dyn.d_un.d_val == strindex)
1233 if (buf != NULL)
1234 free (buf);
1235 if (extversym != NULL)
1236 free (extversym);
1237 return true;
1242 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1243 goto error_return;
1246 /* Save the SONAME, if there is one, because sometimes the
1247 linker emulation code will need to know it. */
1248 if (*name == '\0')
1249 name = bfd_get_filename (abfd);
1250 elf_dt_name (abfd) = name;
1253 if (bfd_seek (abfd,
1254 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
1255 SEEK_SET) != 0
1256 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
1257 != extsymcount * sizeof (Elf_External_Sym)))
1258 goto error_return;
1260 weaks = NULL;
1262 ever = extversym != NULL ? extversym + extsymoff : NULL;
1263 esymend = buf + extsymcount;
1264 for (esym = buf;
1265 esym < esymend;
1266 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1268 Elf_Internal_Sym sym;
1269 int bind;
1270 bfd_vma value;
1271 asection *sec;
1272 flagword flags;
1273 const char *name;
1274 struct elf_link_hash_entry *h;
1275 boolean definition;
1276 boolean size_change_ok, type_change_ok;
1277 boolean new_weakdef;
1278 unsigned int old_alignment;
1280 elf_swap_symbol_in (abfd, esym, &sym);
1282 flags = BSF_NO_FLAGS;
1283 sec = NULL;
1284 value = sym.st_value;
1285 *sym_hash = NULL;
1287 bind = ELF_ST_BIND (sym.st_info);
1288 if (bind == STB_LOCAL)
1290 /* This should be impossible, since ELF requires that all
1291 global symbols follow all local symbols, and that sh_info
1292 point to the first global symbol. Unfortunatealy, Irix 5
1293 screws this up. */
1294 continue;
1296 else if (bind == STB_GLOBAL)
1298 if (sym.st_shndx != SHN_UNDEF
1299 && sym.st_shndx != SHN_COMMON)
1300 flags = BSF_GLOBAL;
1301 else
1302 flags = 0;
1304 else if (bind == STB_WEAK)
1305 flags = BSF_WEAK;
1306 else
1308 /* Leave it up to the processor backend. */
1311 if (sym.st_shndx == SHN_UNDEF)
1312 sec = bfd_und_section_ptr;
1313 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1315 sec = section_from_elf_index (abfd, sym.st_shndx);
1316 if (sec == NULL)
1317 sec = bfd_abs_section_ptr;
1318 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1319 value -= sec->vma;
1321 else if (sym.st_shndx == SHN_ABS)
1322 sec = bfd_abs_section_ptr;
1323 else if (sym.st_shndx == SHN_COMMON)
1325 sec = bfd_com_section_ptr;
1326 /* What ELF calls the size we call the value. What ELF
1327 calls the value we call the alignment. */
1328 value = sym.st_size;
1330 else
1332 /* Leave it up to the processor backend. */
1335 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1336 if (name == (const char *) NULL)
1337 goto error_return;
1339 if (add_symbol_hook)
1341 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1342 &value))
1343 goto error_return;
1345 /* The hook function sets the name to NULL if this symbol
1346 should be skipped for some reason. */
1347 if (name == (const char *) NULL)
1348 continue;
1351 /* Sanity check that all possibilities were handled. */
1352 if (sec == (asection *) NULL)
1354 bfd_set_error (bfd_error_bad_value);
1355 goto error_return;
1358 if (bfd_is_und_section (sec)
1359 || bfd_is_com_section (sec))
1360 definition = false;
1361 else
1362 definition = true;
1364 size_change_ok = false;
1365 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1366 old_alignment = 0;
1367 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1369 Elf_Internal_Versym iver;
1370 unsigned int vernum = 0;
1371 boolean override;
1373 if (ever != NULL)
1375 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1376 vernum = iver.vs_vers & VERSYM_VERSION;
1378 /* If this is a hidden symbol, or if it is not version
1379 1, we append the version name to the symbol name.
1380 However, we do not modify a non-hidden absolute
1381 symbol, because it might be the version symbol
1382 itself. FIXME: What if it isn't? */
1383 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1384 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1386 const char *verstr;
1387 int namelen, newlen;
1388 char *newname, *p;
1390 if (sym.st_shndx != SHN_UNDEF)
1392 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1394 (*_bfd_error_handler)
1395 (_("%s: %s: invalid version %u (max %d)"),
1396 bfd_get_filename (abfd), name, vernum,
1397 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1398 bfd_set_error (bfd_error_bad_value);
1399 goto error_return;
1401 else if (vernum > 1)
1402 verstr =
1403 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1404 else
1405 verstr = "";
1407 else
1409 /* We cannot simply test for the number of
1410 entries in the VERNEED section since the
1411 numbers for the needed versions do not start
1412 at 0. */
1413 Elf_Internal_Verneed *t;
1415 verstr = NULL;
1416 for (t = elf_tdata (abfd)->verref;
1417 t != NULL;
1418 t = t->vn_nextref)
1420 Elf_Internal_Vernaux *a;
1422 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1424 if (a->vna_other == vernum)
1426 verstr = a->vna_nodename;
1427 break;
1430 if (a != NULL)
1431 break;
1433 if (verstr == NULL)
1435 (*_bfd_error_handler)
1436 (_("%s: %s: invalid needed version %d"),
1437 bfd_get_filename (abfd), name, vernum);
1438 bfd_set_error (bfd_error_bad_value);
1439 goto error_return;
1443 namelen = strlen (name);
1444 newlen = namelen + strlen (verstr) + 2;
1445 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1446 ++newlen;
1448 newname = (char *) bfd_alloc (abfd, newlen);
1449 if (newname == NULL)
1450 goto error_return;
1451 strcpy (newname, name);
1452 p = newname + namelen;
1453 *p++ = ELF_VER_CHR;
1454 /* If this is a defined non-hidden version symbol,
1455 we add another @ to the name. This indicates the
1456 default version of the symbol. */
1457 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
1458 && sym.st_shndx != SHN_UNDEF)
1459 *p++ = ELF_VER_CHR;
1460 strcpy (p, verstr);
1462 name = newname;
1466 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1467 sym_hash, &override, &type_change_ok,
1468 &size_change_ok))
1469 goto error_return;
1471 if (override)
1472 definition = false;
1474 h = *sym_hash;
1475 while (h->root.type == bfd_link_hash_indirect
1476 || h->root.type == bfd_link_hash_warning)
1477 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1479 /* Remember the old alignment if this is a common symbol, so
1480 that we don't reduce the alignment later on. We can't
1481 check later, because _bfd_generic_link_add_one_symbol
1482 will set a default for the alignment which we want to
1483 override. */
1484 if (h->root.type == bfd_link_hash_common)
1485 old_alignment = h->root.u.c.p->alignment_power;
1487 if (elf_tdata (abfd)->verdef != NULL
1488 && ! override
1489 && vernum > 1
1490 && definition)
1491 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1494 if (! (_bfd_generic_link_add_one_symbol
1495 (info, abfd, name, flags, sec, value, (const char *) NULL,
1496 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1497 goto error_return;
1499 h = *sym_hash;
1500 while (h->root.type == bfd_link_hash_indirect
1501 || h->root.type == bfd_link_hash_warning)
1502 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1503 *sym_hash = h;
1505 new_weakdef = false;
1506 if (dynamic
1507 && definition
1508 && (flags & BSF_WEAK) != 0
1509 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1510 && info->hash->creator->flavour == bfd_target_elf_flavour
1511 && h->weakdef == NULL)
1513 /* Keep a list of all weak defined non function symbols from
1514 a dynamic object, using the weakdef field. Later in this
1515 function we will set the weakdef field to the correct
1516 value. We only put non-function symbols from dynamic
1517 objects on this list, because that happens to be the only
1518 time we need to know the normal symbol corresponding to a
1519 weak symbol, and the information is time consuming to
1520 figure out. If the weakdef field is not already NULL,
1521 then this symbol was already defined by some previous
1522 dynamic object, and we will be using that previous
1523 definition anyhow. */
1525 h->weakdef = weaks;
1526 weaks = h;
1527 new_weakdef = true;
1530 /* Set the alignment of a common symbol. */
1531 if (sym.st_shndx == SHN_COMMON
1532 && h->root.type == bfd_link_hash_common)
1534 unsigned int align;
1536 align = bfd_log2 (sym.st_value);
1537 if (align > old_alignment)
1538 h->root.u.c.p->alignment_power = align;
1541 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1543 int old_flags;
1544 boolean dynsym;
1545 int new_flag;
1547 /* Remember the symbol size and type. */
1548 if (sym.st_size != 0
1549 && (definition || h->size == 0))
1551 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1552 (*_bfd_error_handler)
1553 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1554 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1555 bfd_get_filename (abfd));
1557 h->size = sym.st_size;
1560 /* If this is a common symbol, then we always want H->SIZE
1561 to be the size of the common symbol. The code just above
1562 won't fix the size if a common symbol becomes larger. We
1563 don't warn about a size change here, because that is
1564 covered by --warn-common. */
1565 if (h->root.type == bfd_link_hash_common)
1566 h->size = h->root.u.c.size;
1568 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1569 && (definition || h->type == STT_NOTYPE))
1571 if (h->type != STT_NOTYPE
1572 && h->type != ELF_ST_TYPE (sym.st_info)
1573 && ! type_change_ok)
1574 (*_bfd_error_handler)
1575 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1576 name, h->type, ELF_ST_TYPE (sym.st_info),
1577 bfd_get_filename (abfd));
1579 h->type = ELF_ST_TYPE (sym.st_info);
1582 /* If st_other has a processor-specific meaning, specific code
1583 might be needed here. */
1584 if (sym.st_other != 0)
1586 /* Combine visibilities, using the most constraining one. */
1587 unsigned char hvis = ELF_ST_VISIBILITY (h->other);
1588 unsigned char symvis = ELF_ST_VISIBILITY (sym.st_other);
1590 if (symvis && (hvis > symvis || hvis == 0))
1591 h->other = sym.st_other;
1593 /* If neither has visibility, use the st_other of the
1594 definition. This is an arbitrary choice, since the
1595 other bits have no general meaning. */
1596 if (!symvis && !hvis
1597 && (definition || h->other == 0))
1598 h->other = sym.st_other;
1601 /* Set a flag in the hash table entry indicating the type of
1602 reference or definition we just found. Keep a count of
1603 the number of dynamic symbols we find. A dynamic symbol
1604 is one which is referenced or defined by both a regular
1605 object and a shared object. */
1606 old_flags = h->elf_link_hash_flags;
1607 dynsym = false;
1608 if (! dynamic)
1610 if (! definition)
1612 new_flag = ELF_LINK_HASH_REF_REGULAR;
1613 if (bind != STB_WEAK)
1614 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1616 else
1617 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1618 if (info->shared
1619 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1620 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1621 dynsym = true;
1623 else
1625 if (! definition)
1626 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1627 else
1628 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1629 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1630 | ELF_LINK_HASH_REF_REGULAR)) != 0
1631 || (h->weakdef != NULL
1632 && ! new_weakdef
1633 && h->weakdef->dynindx != -1))
1634 dynsym = true;
1637 h->elf_link_hash_flags |= new_flag;
1639 /* If this symbol has a version, and it is the default
1640 version, we create an indirect symbol from the default
1641 name to the fully decorated name. This will cause
1642 external references which do not specify a version to be
1643 bound to this version of the symbol. */
1644 if (definition)
1646 char *p;
1648 p = strchr (name, ELF_VER_CHR);
1649 if (p != NULL && p[1] == ELF_VER_CHR)
1651 char *shortname;
1652 struct elf_link_hash_entry *hi;
1653 boolean override;
1655 shortname = bfd_hash_allocate (&info->hash->table,
1656 p - name + 1);
1657 if (shortname == NULL)
1658 goto error_return;
1659 strncpy (shortname, name, p - name);
1660 shortname[p - name] = '\0';
1662 /* We are going to create a new symbol. Merge it
1663 with any existing symbol with this name. For the
1664 purposes of the merge, act as though we were
1665 defining the symbol we just defined, although we
1666 actually going to define an indirect symbol. */
1667 type_change_ok = false;
1668 size_change_ok = false;
1669 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1670 &value, &hi, &override,
1671 &type_change_ok, &size_change_ok))
1672 goto error_return;
1674 if (! override)
1676 if (! (_bfd_generic_link_add_one_symbol
1677 (info, abfd, shortname, BSF_INDIRECT,
1678 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1679 collect, (struct bfd_link_hash_entry **) &hi)))
1680 goto error_return;
1682 else
1684 /* In this case the symbol named SHORTNAME is
1685 overriding the indirect symbol we want to
1686 add. We were planning on making SHORTNAME an
1687 indirect symbol referring to NAME. SHORTNAME
1688 is the name without a version. NAME is the
1689 fully versioned name, and it is the default
1690 version.
1692 Overriding means that we already saw a
1693 definition for the symbol SHORTNAME in a
1694 regular object, and it is overriding the
1695 symbol defined in the dynamic object.
1697 When this happens, we actually want to change
1698 NAME, the symbol we just added, to refer to
1699 SHORTNAME. This will cause references to
1700 NAME in the shared object to become
1701 references to SHORTNAME in the regular
1702 object. This is what we expect when we
1703 override a function in a shared object: that
1704 the references in the shared object will be
1705 mapped to the definition in the regular
1706 object. */
1708 while (hi->root.type == bfd_link_hash_indirect
1709 || hi->root.type == bfd_link_hash_warning)
1710 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1712 h->root.type = bfd_link_hash_indirect;
1713 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1714 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1716 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1717 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1718 if (hi->elf_link_hash_flags
1719 & (ELF_LINK_HASH_REF_REGULAR
1720 | ELF_LINK_HASH_DEF_REGULAR))
1722 if (! _bfd_elf_link_record_dynamic_symbol (info,
1723 hi))
1724 goto error_return;
1728 /* Now set HI to H, so that the following code
1729 will set the other fields correctly. */
1730 hi = h;
1733 /* If there is a duplicate definition somewhere,
1734 then HI may not point to an indirect symbol. We
1735 will have reported an error to the user in that
1736 case. */
1738 if (hi->root.type == bfd_link_hash_indirect)
1740 struct elf_link_hash_entry *ht;
1742 /* If the symbol became indirect, then we assume
1743 that we have not seen a definition before. */
1744 BFD_ASSERT ((hi->elf_link_hash_flags
1745 & (ELF_LINK_HASH_DEF_DYNAMIC
1746 | ELF_LINK_HASH_DEF_REGULAR))
1747 == 0);
1749 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1750 (*bed->elf_backend_copy_indirect_symbol) (ht, hi);
1752 /* See if the new flags lead us to realize that
1753 the symbol must be dynamic. */
1754 if (! dynsym)
1756 if (! dynamic)
1758 if (info->shared
1759 || ((hi->elf_link_hash_flags
1760 & ELF_LINK_HASH_REF_DYNAMIC)
1761 != 0))
1762 dynsym = true;
1764 else
1766 if ((hi->elf_link_hash_flags
1767 & ELF_LINK_HASH_REF_REGULAR) != 0)
1768 dynsym = true;
1773 /* We also need to define an indirection from the
1774 nondefault version of the symbol. */
1776 shortname = bfd_hash_allocate (&info->hash->table,
1777 strlen (name));
1778 if (shortname == NULL)
1779 goto error_return;
1780 strncpy (shortname, name, p - name);
1781 strcpy (shortname + (p - name), p + 1);
1783 /* Once again, merge with any existing symbol. */
1784 type_change_ok = false;
1785 size_change_ok = false;
1786 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1787 &value, &hi, &override,
1788 &type_change_ok, &size_change_ok))
1789 goto error_return;
1791 if (override)
1793 /* Here SHORTNAME is a versioned name, so we
1794 don't expect to see the type of override we
1795 do in the case above. */
1796 (*_bfd_error_handler)
1797 (_("%s: warning: unexpected redefinition of `%s'"),
1798 bfd_get_filename (abfd), shortname);
1800 else
1802 if (! (_bfd_generic_link_add_one_symbol
1803 (info, abfd, shortname, BSF_INDIRECT,
1804 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1805 collect, (struct bfd_link_hash_entry **) &hi)))
1806 goto error_return;
1808 /* If there is a duplicate definition somewhere,
1809 then HI may not point to an indirect symbol.
1810 We will have reported an error to the user in
1811 that case. */
1813 if (hi->root.type == bfd_link_hash_indirect)
1815 /* If the symbol became indirect, then we
1816 assume that we have not seen a definition
1817 before. */
1818 BFD_ASSERT ((hi->elf_link_hash_flags
1819 & (ELF_LINK_HASH_DEF_DYNAMIC
1820 | ELF_LINK_HASH_DEF_REGULAR))
1821 == 0);
1823 (*bed->elf_backend_copy_indirect_symbol) (h, hi);
1825 /* See if the new flags lead us to realize
1826 that the symbol must be dynamic. */
1827 if (! dynsym)
1829 if (! dynamic)
1831 if (info->shared
1832 || ((hi->elf_link_hash_flags
1833 & ELF_LINK_HASH_REF_DYNAMIC)
1834 != 0))
1835 dynsym = true;
1837 else
1839 if ((hi->elf_link_hash_flags
1840 & ELF_LINK_HASH_REF_REGULAR) != 0)
1841 dynsym = true;
1849 if (dynsym && h->dynindx == -1)
1851 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1852 goto error_return;
1853 if (h->weakdef != NULL
1854 && ! new_weakdef
1855 && h->weakdef->dynindx == -1)
1857 if (! _bfd_elf_link_record_dynamic_symbol (info,
1858 h->weakdef))
1859 goto error_return;
1862 else if (dynsym && h->dynindx != -1)
1863 /* If the symbol already has a dynamic index, but
1864 visibility says it should not be visible, turn it into
1865 a local symbol. */
1866 switch (ELF_ST_VISIBILITY (h->other))
1868 case STV_INTERNAL:
1869 case STV_HIDDEN:
1870 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
1871 (*bed->elf_backend_hide_symbol) (info, h);
1872 break;
1875 if (dt_needed && definition
1876 && (h->elf_link_hash_flags
1877 & ELF_LINK_HASH_REF_REGULAR) != 0)
1879 bfd_size_type oldsize;
1880 bfd_size_type strindex;
1882 /* The symbol from a DT_NEEDED object is referenced from
1883 the regular object to create a dynamic executable. We
1884 have to make sure there is a DT_NEEDED entry for it. */
1886 dt_needed = false;
1887 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1888 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
1889 elf_dt_soname (abfd),
1890 true, false);
1891 if (strindex == (bfd_size_type) -1)
1892 goto error_return;
1894 if (oldsize
1895 == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1897 asection *sdyn;
1898 Elf_External_Dyn *dyncon, *dynconend;
1900 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1901 ".dynamic");
1902 BFD_ASSERT (sdyn != NULL);
1904 dyncon = (Elf_External_Dyn *) sdyn->contents;
1905 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1906 sdyn->_raw_size);
1907 for (; dyncon < dynconend; dyncon++)
1909 Elf_Internal_Dyn dyn;
1911 elf_swap_dyn_in (elf_hash_table (info)->dynobj,
1912 dyncon, &dyn);
1913 BFD_ASSERT (dyn.d_tag != DT_NEEDED ||
1914 dyn.d_un.d_val != strindex);
1918 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1919 goto error_return;
1924 /* Now set the weakdefs field correctly for all the weak defined
1925 symbols we found. The only way to do this is to search all the
1926 symbols. Since we only need the information for non functions in
1927 dynamic objects, that's the only time we actually put anything on
1928 the list WEAKS. We need this information so that if a regular
1929 object refers to a symbol defined weakly in a dynamic object, the
1930 real symbol in the dynamic object is also put in the dynamic
1931 symbols; we also must arrange for both symbols to point to the
1932 same memory location. We could handle the general case of symbol
1933 aliasing, but a general symbol alias can only be generated in
1934 assembler code, handling it correctly would be very time
1935 consuming, and other ELF linkers don't handle general aliasing
1936 either. */
1937 while (weaks != NULL)
1939 struct elf_link_hash_entry *hlook;
1940 asection *slook;
1941 bfd_vma vlook;
1942 struct elf_link_hash_entry **hpp;
1943 struct elf_link_hash_entry **hppend;
1945 hlook = weaks;
1946 weaks = hlook->weakdef;
1947 hlook->weakdef = NULL;
1949 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
1950 || hlook->root.type == bfd_link_hash_defweak
1951 || hlook->root.type == bfd_link_hash_common
1952 || hlook->root.type == bfd_link_hash_indirect);
1953 slook = hlook->root.u.def.section;
1954 vlook = hlook->root.u.def.value;
1956 hpp = elf_sym_hashes (abfd);
1957 hppend = hpp + extsymcount;
1958 for (; hpp < hppend; hpp++)
1960 struct elf_link_hash_entry *h;
1962 h = *hpp;
1963 if (h != NULL && h != hlook
1964 && h->root.type == bfd_link_hash_defined
1965 && h->root.u.def.section == slook
1966 && h->root.u.def.value == vlook)
1968 hlook->weakdef = h;
1970 /* If the weak definition is in the list of dynamic
1971 symbols, make sure the real definition is put there
1972 as well. */
1973 if (hlook->dynindx != -1
1974 && h->dynindx == -1)
1976 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1977 goto error_return;
1980 /* If the real definition is in the list of dynamic
1981 symbols, make sure the weak definition is put there
1982 as well. If we don't do this, then the dynamic
1983 loader might not merge the entries for the real
1984 definition and the weak definition. */
1985 if (h->dynindx != -1
1986 && hlook->dynindx == -1)
1988 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
1989 goto error_return;
1992 break;
1997 if (buf != NULL)
1999 free (buf);
2000 buf = NULL;
2003 if (extversym != NULL)
2005 free (extversym);
2006 extversym = NULL;
2009 /* If this object is the same format as the output object, and it is
2010 not a shared library, then let the backend look through the
2011 relocs.
2013 This is required to build global offset table entries and to
2014 arrange for dynamic relocs. It is not required for the
2015 particular common case of linking non PIC code, even when linking
2016 against shared libraries, but unfortunately there is no way of
2017 knowing whether an object file has been compiled PIC or not.
2018 Looking through the relocs is not particularly time consuming.
2019 The problem is that we must either (1) keep the relocs in memory,
2020 which causes the linker to require additional runtime memory or
2021 (2) read the relocs twice from the input file, which wastes time.
2022 This would be a good case for using mmap.
2024 I have no idea how to handle linking PIC code into a file of a
2025 different format. It probably can't be done. */
2026 check_relocs = get_elf_backend_data (abfd)->check_relocs;
2027 if (! dynamic
2028 && abfd->xvec == info->hash->creator
2029 && check_relocs != NULL)
2031 asection *o;
2033 for (o = abfd->sections; o != NULL; o = o->next)
2035 Elf_Internal_Rela *internal_relocs;
2036 boolean ok;
2038 if ((o->flags & SEC_RELOC) == 0
2039 || o->reloc_count == 0
2040 || ((info->strip == strip_all || info->strip == strip_debugger)
2041 && (o->flags & SEC_DEBUGGING) != 0)
2042 || bfd_is_abs_section (o->output_section))
2043 continue;
2045 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
2046 (abfd, o, (PTR) NULL,
2047 (Elf_Internal_Rela *) NULL,
2048 info->keep_memory));
2049 if (internal_relocs == NULL)
2050 goto error_return;
2052 ok = (*check_relocs) (abfd, info, o, internal_relocs);
2054 if (! info->keep_memory)
2055 free (internal_relocs);
2057 if (! ok)
2058 goto error_return;
2062 /* If this is a non-traditional, non-relocateable link, try to
2063 optimize the handling of the .stab/.stabstr sections. */
2064 if (! dynamic
2065 && ! info->relocateable
2066 && ! info->traditional_format
2067 && info->hash->creator->flavour == bfd_target_elf_flavour
2068 && (info->strip != strip_all && info->strip != strip_debugger))
2070 asection *stab, *stabstr;
2072 stab = bfd_get_section_by_name (abfd, ".stab");
2073 if (stab != NULL)
2075 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
2077 if (stabstr != NULL)
2079 struct bfd_elf_section_data *secdata;
2081 secdata = elf_section_data (stab);
2082 if (! _bfd_link_section_stabs (abfd,
2083 &elf_hash_table (info)->stab_info,
2084 stab, stabstr,
2085 &secdata->stab_info))
2086 goto error_return;
2091 return true;
2093 error_return:
2094 if (buf != NULL)
2095 free (buf);
2096 if (dynbuf != NULL)
2097 free (dynbuf);
2098 if (dynver != NULL)
2099 free (dynver);
2100 if (extversym != NULL)
2101 free (extversym);
2102 return false;
2105 /* Create some sections which will be filled in with dynamic linking
2106 information. ABFD is an input file which requires dynamic sections
2107 to be created. The dynamic sections take up virtual memory space
2108 when the final executable is run, so we need to create them before
2109 addresses are assigned to the output sections. We work out the
2110 actual contents and size of these sections later. */
2112 boolean
2113 elf_link_create_dynamic_sections (abfd, info)
2114 bfd *abfd;
2115 struct bfd_link_info *info;
2117 flagword flags;
2118 register asection *s;
2119 struct elf_link_hash_entry *h;
2120 struct elf_backend_data *bed;
2122 if (elf_hash_table (info)->dynamic_sections_created)
2123 return true;
2125 /* Make sure that all dynamic sections use the same input BFD. */
2126 if (elf_hash_table (info)->dynobj == NULL)
2127 elf_hash_table (info)->dynobj = abfd;
2128 else
2129 abfd = elf_hash_table (info)->dynobj;
2131 /* Note that we set the SEC_IN_MEMORY flag for all of these
2132 sections. */
2133 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
2134 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2136 /* A dynamically linked executable has a .interp section, but a
2137 shared library does not. */
2138 if (! info->shared)
2140 s = bfd_make_section (abfd, ".interp");
2141 if (s == NULL
2142 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2143 return false;
2146 /* Create sections to hold version informations. These are removed
2147 if they are not needed. */
2148 s = bfd_make_section (abfd, ".gnu.version_d");
2149 if (s == NULL
2150 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2151 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2152 return false;
2154 s = bfd_make_section (abfd, ".gnu.version");
2155 if (s == NULL
2156 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2157 || ! bfd_set_section_alignment (abfd, s, 1))
2158 return false;
2160 s = bfd_make_section (abfd, ".gnu.version_r");
2161 if (s == NULL
2162 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2163 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2164 return false;
2166 s = bfd_make_section (abfd, ".dynsym");
2167 if (s == NULL
2168 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2169 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2170 return false;
2172 s = bfd_make_section (abfd, ".dynstr");
2173 if (s == NULL
2174 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2175 return false;
2177 /* Create a strtab to hold the dynamic symbol names. */
2178 if (elf_hash_table (info)->dynstr == NULL)
2180 elf_hash_table (info)->dynstr = elf_stringtab_init ();
2181 if (elf_hash_table (info)->dynstr == NULL)
2182 return false;
2185 s = bfd_make_section (abfd, ".dynamic");
2186 if (s == NULL
2187 || ! bfd_set_section_flags (abfd, s, flags)
2188 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2189 return false;
2191 /* The special symbol _DYNAMIC is always set to the start of the
2192 .dynamic section. This call occurs before we have processed the
2193 symbols for any dynamic object, so we don't have to worry about
2194 overriding a dynamic definition. We could set _DYNAMIC in a
2195 linker script, but we only want to define it if we are, in fact,
2196 creating a .dynamic section. We don't want to define it if there
2197 is no .dynamic section, since on some ELF platforms the start up
2198 code examines it to decide how to initialize the process. */
2199 h = NULL;
2200 if (! (_bfd_generic_link_add_one_symbol
2201 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
2202 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
2203 (struct bfd_link_hash_entry **) &h)))
2204 return false;
2205 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2206 h->type = STT_OBJECT;
2208 if (info->shared
2209 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
2210 return false;
2212 bed = get_elf_backend_data (abfd);
2214 s = bfd_make_section (abfd, ".hash");
2215 if (s == NULL
2216 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2217 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2218 return false;
2219 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
2221 /* Let the backend create the rest of the sections. This lets the
2222 backend set the right flags. The backend will normally create
2223 the .got and .plt sections. */
2224 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
2225 return false;
2227 elf_hash_table (info)->dynamic_sections_created = true;
2229 return true;
2232 /* Add an entry to the .dynamic table. */
2234 boolean
2235 elf_add_dynamic_entry (info, tag, val)
2236 struct bfd_link_info *info;
2237 bfd_vma tag;
2238 bfd_vma val;
2240 Elf_Internal_Dyn dyn;
2241 bfd *dynobj;
2242 asection *s;
2243 size_t newsize;
2244 bfd_byte *newcontents;
2246 dynobj = elf_hash_table (info)->dynobj;
2248 s = bfd_get_section_by_name (dynobj, ".dynamic");
2249 BFD_ASSERT (s != NULL);
2251 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
2252 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
2253 if (newcontents == NULL)
2254 return false;
2256 dyn.d_tag = tag;
2257 dyn.d_un.d_val = val;
2258 elf_swap_dyn_out (dynobj, &dyn,
2259 (Elf_External_Dyn *) (newcontents + s->_raw_size));
2261 s->_raw_size = newsize;
2262 s->contents = newcontents;
2264 return true;
2267 /* Record a new local dynamic symbol. */
2269 boolean
2270 elf_link_record_local_dynamic_symbol (info, input_bfd, input_indx)
2271 struct bfd_link_info *info;
2272 bfd *input_bfd;
2273 long input_indx;
2275 struct elf_link_local_dynamic_entry *entry;
2276 struct elf_link_hash_table *eht;
2277 struct bfd_strtab_hash *dynstr;
2278 Elf_External_Sym esym;
2279 unsigned long dynstr_index;
2280 char *name;
2282 /* See if the entry exists already. */
2283 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
2284 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
2285 return true;
2287 entry = (struct elf_link_local_dynamic_entry *)
2288 bfd_alloc (input_bfd, sizeof (*entry));
2289 if (entry == NULL)
2290 return false;
2292 /* Go find the symbol, so that we can find it's name. */
2293 if (bfd_seek (input_bfd,
2294 (elf_tdata (input_bfd)->symtab_hdr.sh_offset
2295 + input_indx * sizeof (Elf_External_Sym)),
2296 SEEK_SET) != 0
2297 || (bfd_read (&esym, sizeof (Elf_External_Sym), 1, input_bfd)
2298 != sizeof (Elf_External_Sym)))
2299 return false;
2300 elf_swap_symbol_in (input_bfd, &esym, &entry->isym);
2302 name = (bfd_elf_string_from_elf_section
2303 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
2304 entry->isym.st_name));
2306 dynstr = elf_hash_table (info)->dynstr;
2307 if (dynstr == NULL)
2309 /* Create a strtab to hold the dynamic symbol names. */
2310 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_stringtab_init ();
2311 if (dynstr == NULL)
2312 return false;
2315 dynstr_index = _bfd_stringtab_add (dynstr, name, true, false);
2316 if (dynstr_index == (unsigned long) -1)
2317 return false;
2318 entry->isym.st_name = dynstr_index;
2320 eht = elf_hash_table (info);
2322 entry->next = eht->dynlocal;
2323 eht->dynlocal = entry;
2324 entry->input_bfd = input_bfd;
2325 entry->input_indx = input_indx;
2326 eht->dynsymcount++;
2328 /* Whatever binding the symbol had before, it's now local. */
2329 entry->isym.st_info
2330 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
2332 /* The dynindx will be set at the end of size_dynamic_sections. */
2334 return true;
2338 /* Read and swap the relocs from the section indicated by SHDR. This
2339 may be either a REL or a RELA section. The relocations are
2340 translated into RELA relocations and stored in INTERNAL_RELOCS,
2341 which should have already been allocated to contain enough space.
2342 The EXTERNAL_RELOCS are a buffer where the external form of the
2343 relocations should be stored.
2345 Returns false if something goes wrong. */
2347 static boolean
2348 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2349 internal_relocs)
2350 bfd *abfd;
2351 Elf_Internal_Shdr *shdr;
2352 PTR external_relocs;
2353 Elf_Internal_Rela *internal_relocs;
2355 struct elf_backend_data *bed;
2357 /* If there aren't any relocations, that's OK. */
2358 if (!shdr)
2359 return true;
2361 /* Position ourselves at the start of the section. */
2362 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2363 return false;
2365 /* Read the relocations. */
2366 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2367 != shdr->sh_size)
2368 return false;
2370 bed = get_elf_backend_data (abfd);
2372 /* Convert the external relocations to the internal format. */
2373 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2375 Elf_External_Rel *erel;
2376 Elf_External_Rel *erelend;
2377 Elf_Internal_Rela *irela;
2378 Elf_Internal_Rel *irel;
2380 erel = (Elf_External_Rel *) external_relocs;
2381 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2382 irela = internal_relocs;
2383 irel = bfd_alloc (abfd, (bed->s->int_rels_per_ext_rel
2384 * sizeof (Elf_Internal_Rel)));
2385 for (; erel < erelend; erel++, irela += bed->s->int_rels_per_ext_rel)
2387 unsigned char i;
2389 if (bed->s->swap_reloc_in)
2390 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, irel);
2391 else
2392 elf_swap_reloc_in (abfd, erel, irel);
2394 for (i = 0; i < bed->s->int_rels_per_ext_rel; ++i)
2396 irela[i].r_offset = irel[i].r_offset;
2397 irela[i].r_info = irel[i].r_info;
2398 irela[i].r_addend = 0;
2402 else
2404 Elf_External_Rela *erela;
2405 Elf_External_Rela *erelaend;
2406 Elf_Internal_Rela *irela;
2408 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2410 erela = (Elf_External_Rela *) external_relocs;
2411 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2412 irela = internal_relocs;
2413 for (; erela < erelaend; erela++, irela += bed->s->int_rels_per_ext_rel)
2415 if (bed->s->swap_reloca_in)
2416 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, irela);
2417 else
2418 elf_swap_reloca_in (abfd, erela, irela);
2422 return true;
2425 /* Read and swap the relocs for a section O. They may have been
2426 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2427 not NULL, they are used as buffers to read into. They are known to
2428 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
2429 the return value is allocated using either malloc or bfd_alloc,
2430 according to the KEEP_MEMORY argument. If O has two relocation
2431 sections (both REL and RELA relocations), then the REL_HDR
2432 relocations will appear first in INTERNAL_RELOCS, followed by the
2433 REL_HDR2 relocations. */
2435 Elf_Internal_Rela *
2436 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2437 keep_memory)
2438 bfd *abfd;
2439 asection *o;
2440 PTR external_relocs;
2441 Elf_Internal_Rela *internal_relocs;
2442 boolean keep_memory;
2444 Elf_Internal_Shdr *rel_hdr;
2445 PTR alloc1 = NULL;
2446 Elf_Internal_Rela *alloc2 = NULL;
2447 struct elf_backend_data *bed = get_elf_backend_data (abfd);
2449 if (elf_section_data (o)->relocs != NULL)
2450 return elf_section_data (o)->relocs;
2452 if (o->reloc_count == 0)
2453 return NULL;
2455 rel_hdr = &elf_section_data (o)->rel_hdr;
2457 if (internal_relocs == NULL)
2459 size_t size;
2461 size = (o->reloc_count * bed->s->int_rels_per_ext_rel
2462 * sizeof (Elf_Internal_Rela));
2463 if (keep_memory)
2464 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2465 else
2466 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2467 if (internal_relocs == NULL)
2468 goto error_return;
2471 if (external_relocs == NULL)
2473 size_t size = (size_t) rel_hdr->sh_size;
2475 if (elf_section_data (o)->rel_hdr2)
2476 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2477 alloc1 = (PTR) bfd_malloc (size);
2478 if (alloc1 == NULL)
2479 goto error_return;
2480 external_relocs = alloc1;
2483 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2484 external_relocs,
2485 internal_relocs))
2486 goto error_return;
2487 if (!elf_link_read_relocs_from_section
2488 (abfd,
2489 elf_section_data (o)->rel_hdr2,
2490 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
2491 internal_relocs + (rel_hdr->sh_size / rel_hdr->sh_entsize
2492 * bed->s->int_rels_per_ext_rel)))
2493 goto error_return;
2495 /* Cache the results for next time, if we can. */
2496 if (keep_memory)
2497 elf_section_data (o)->relocs = internal_relocs;
2499 if (alloc1 != NULL)
2500 free (alloc1);
2502 /* Don't free alloc2, since if it was allocated we are passing it
2503 back (under the name of internal_relocs). */
2505 return internal_relocs;
2507 error_return:
2508 if (alloc1 != NULL)
2509 free (alloc1);
2510 if (alloc2 != NULL)
2511 free (alloc2);
2512 return NULL;
2516 /* Record an assignment to a symbol made by a linker script. We need
2517 this in case some dynamic object refers to this symbol. */
2519 /*ARGSUSED*/
2520 boolean
2521 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2522 bfd *output_bfd ATTRIBUTE_UNUSED;
2523 struct bfd_link_info *info;
2524 const char *name;
2525 boolean provide;
2527 struct elf_link_hash_entry *h;
2529 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2530 return true;
2532 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2533 if (h == NULL)
2534 return false;
2536 if (h->root.type == bfd_link_hash_new)
2537 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2539 /* If this symbol is being provided by the linker script, and it is
2540 currently defined by a dynamic object, but not by a regular
2541 object, then mark it as undefined so that the generic linker will
2542 force the correct value. */
2543 if (provide
2544 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2545 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2546 h->root.type = bfd_link_hash_undefined;
2548 /* If this symbol is not being provided by the linker script, and it is
2549 currently defined by a dynamic object, but not by a regular object,
2550 then clear out any version information because the symbol will not be
2551 associated with the dynamic object any more. */
2552 if (!provide
2553 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2554 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2555 h->verinfo.verdef = NULL;
2557 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2559 /* When possible, keep the original type of the symbol */
2560 if (h->type == STT_NOTYPE)
2561 h->type = STT_OBJECT;
2563 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2564 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2565 || info->shared)
2566 && h->dynindx == -1)
2568 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2569 return false;
2571 /* If this is a weak defined symbol, and we know a corresponding
2572 real symbol from the same dynamic object, make sure the real
2573 symbol is also made into a dynamic symbol. */
2574 if (h->weakdef != NULL
2575 && h->weakdef->dynindx == -1)
2577 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2578 return false;
2582 return true;
2585 /* This structure is used to pass information to
2586 elf_link_assign_sym_version. */
2588 struct elf_assign_sym_version_info
2590 /* Output BFD. */
2591 bfd *output_bfd;
2592 /* General link information. */
2593 struct bfd_link_info *info;
2594 /* Version tree. */
2595 struct bfd_elf_version_tree *verdefs;
2596 /* Whether we are exporting all dynamic symbols. */
2597 boolean export_dynamic;
2598 /* Whether we had a failure. */
2599 boolean failed;
2602 /* This structure is used to pass information to
2603 elf_link_find_version_dependencies. */
2605 struct elf_find_verdep_info
2607 /* Output BFD. */
2608 bfd *output_bfd;
2609 /* General link information. */
2610 struct bfd_link_info *info;
2611 /* The number of dependencies. */
2612 unsigned int vers;
2613 /* Whether we had a failure. */
2614 boolean failed;
2617 /* Array used to determine the number of hash table buckets to use
2618 based on the number of symbols there are. If there are fewer than
2619 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2620 fewer than 37 we use 17 buckets, and so forth. We never use more
2621 than 32771 buckets. */
2623 static const size_t elf_buckets[] =
2625 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2626 16411, 32771, 0
2629 /* Compute bucket count for hashing table. We do not use a static set
2630 of possible tables sizes anymore. Instead we determine for all
2631 possible reasonable sizes of the table the outcome (i.e., the
2632 number of collisions etc) and choose the best solution. The
2633 weighting functions are not too simple to allow the table to grow
2634 without bounds. Instead one of the weighting factors is the size.
2635 Therefore the result is always a good payoff between few collisions
2636 (= short chain lengths) and table size. */
2637 static size_t
2638 compute_bucket_count (info)
2639 struct bfd_link_info *info;
2641 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2642 size_t best_size = 0;
2643 unsigned long int *hashcodes;
2644 unsigned long int *hashcodesp;
2645 unsigned long int i;
2647 /* Compute the hash values for all exported symbols. At the same
2648 time store the values in an array so that we could use them for
2649 optimizations. */
2650 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2651 * sizeof (unsigned long int));
2652 if (hashcodes == NULL)
2653 return 0;
2654 hashcodesp = hashcodes;
2656 /* Put all hash values in HASHCODES. */
2657 elf_link_hash_traverse (elf_hash_table (info),
2658 elf_collect_hash_codes, &hashcodesp);
2660 /* We have a problem here. The following code to optimize the table
2661 size requires an integer type with more the 32 bits. If
2662 BFD_HOST_U_64_BIT is set we know about such a type. */
2663 #ifdef BFD_HOST_U_64_BIT
2664 if (info->optimize == true)
2666 unsigned long int nsyms = hashcodesp - hashcodes;
2667 size_t minsize;
2668 size_t maxsize;
2669 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2670 unsigned long int *counts ;
2672 /* Possible optimization parameters: if we have NSYMS symbols we say
2673 that the hashing table must at least have NSYMS/4 and at most
2674 2*NSYMS buckets. */
2675 minsize = nsyms / 4;
2676 if (minsize == 0)
2677 minsize = 1;
2678 best_size = maxsize = nsyms * 2;
2680 /* Create array where we count the collisions in. We must use bfd_malloc
2681 since the size could be large. */
2682 counts = (unsigned long int *) bfd_malloc (maxsize
2683 * sizeof (unsigned long int));
2684 if (counts == NULL)
2686 free (hashcodes);
2687 return 0;
2690 /* Compute the "optimal" size for the hash table. The criteria is a
2691 minimal chain length. The minor criteria is (of course) the size
2692 of the table. */
2693 for (i = minsize; i < maxsize; ++i)
2695 /* Walk through the array of hashcodes and count the collisions. */
2696 BFD_HOST_U_64_BIT max;
2697 unsigned long int j;
2698 unsigned long int fact;
2700 memset (counts, '\0', i * sizeof (unsigned long int));
2702 /* Determine how often each hash bucket is used. */
2703 for (j = 0; j < nsyms; ++j)
2704 ++counts[hashcodes[j] % i];
2706 /* For the weight function we need some information about the
2707 pagesize on the target. This is information need not be 100%
2708 accurate. Since this information is not available (so far) we
2709 define it here to a reasonable default value. If it is crucial
2710 to have a better value some day simply define this value. */
2711 # ifndef BFD_TARGET_PAGESIZE
2712 # define BFD_TARGET_PAGESIZE (4096)
2713 # endif
2715 /* We in any case need 2 + NSYMS entries for the size values and
2716 the chains. */
2717 max = (2 + nsyms) * (ARCH_SIZE / 8);
2719 # if 1
2720 /* Variant 1: optimize for short chains. We add the squares
2721 of all the chain lengths (which favous many small chain
2722 over a few long chains). */
2723 for (j = 0; j < i; ++j)
2724 max += counts[j] * counts[j];
2726 /* This adds penalties for the overall size of the table. */
2727 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2728 max *= fact * fact;
2729 # else
2730 /* Variant 2: Optimize a lot more for small table. Here we
2731 also add squares of the size but we also add penalties for
2732 empty slots (the +1 term). */
2733 for (j = 0; j < i; ++j)
2734 max += (1 + counts[j]) * (1 + counts[j]);
2736 /* The overall size of the table is considered, but not as
2737 strong as in variant 1, where it is squared. */
2738 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2739 max *= fact;
2740 # endif
2742 /* Compare with current best results. */
2743 if (max < best_chlen)
2745 best_chlen = max;
2746 best_size = i;
2750 free (counts);
2752 else
2753 #endif /* defined (BFD_HOST_U_64_BIT) */
2755 /* This is the fallback solution if no 64bit type is available or if we
2756 are not supposed to spend much time on optimizations. We select the
2757 bucket count using a fixed set of numbers. */
2758 for (i = 0; elf_buckets[i] != 0; i++)
2760 best_size = elf_buckets[i];
2761 if (dynsymcount < elf_buckets[i + 1])
2762 break;
2766 /* Free the arrays we needed. */
2767 free (hashcodes);
2769 return best_size;
2772 /* Set up the sizes and contents of the ELF dynamic sections. This is
2773 called by the ELF linker emulation before_allocation routine. We
2774 must set the sizes of the sections before the linker sets the
2775 addresses of the various sections. */
2777 boolean
2778 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2779 export_dynamic, filter_shlib,
2780 auxiliary_filters, info, sinterpptr,
2781 verdefs)
2782 bfd *output_bfd;
2783 const char *soname;
2784 const char *rpath;
2785 boolean export_dynamic;
2786 const char *filter_shlib;
2787 const char * const *auxiliary_filters;
2788 struct bfd_link_info *info;
2789 asection **sinterpptr;
2790 struct bfd_elf_version_tree *verdefs;
2792 bfd_size_type soname_indx;
2793 bfd *dynobj;
2794 struct elf_backend_data *bed;
2795 struct elf_assign_sym_version_info asvinfo;
2797 *sinterpptr = NULL;
2799 soname_indx = (bfd_size_type) -1;
2801 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2802 return true;
2804 /* The backend may have to create some sections regardless of whether
2805 we're dynamic or not. */
2806 bed = get_elf_backend_data (output_bfd);
2807 if (bed->elf_backend_always_size_sections
2808 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2809 return false;
2811 dynobj = elf_hash_table (info)->dynobj;
2813 /* If there were no dynamic objects in the link, there is nothing to
2814 do here. */
2815 if (dynobj == NULL)
2816 return true;
2818 if (elf_hash_table (info)->dynamic_sections_created)
2820 struct elf_info_failed eif;
2821 struct elf_link_hash_entry *h;
2822 bfd_size_type strsize;
2824 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2825 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2827 if (soname != NULL)
2829 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2830 soname, true, true);
2831 if (soname_indx == (bfd_size_type) -1
2832 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2833 return false;
2836 if (info->symbolic)
2838 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2839 return false;
2842 if (rpath != NULL)
2844 bfd_size_type indx;
2846 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2847 true, true);
2848 if (indx == (bfd_size_type) -1
2849 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
2850 return false;
2853 if (filter_shlib != NULL)
2855 bfd_size_type indx;
2857 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2858 filter_shlib, true, true);
2859 if (indx == (bfd_size_type) -1
2860 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2861 return false;
2864 if (auxiliary_filters != NULL)
2866 const char * const *p;
2868 for (p = auxiliary_filters; *p != NULL; p++)
2870 bfd_size_type indx;
2872 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2873 *p, true, true);
2874 if (indx == (bfd_size_type) -1
2875 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2876 return false;
2880 /* If we are supposed to export all symbols into the dynamic symbol
2881 table (this is not the normal case), then do so. */
2882 if (export_dynamic)
2884 struct elf_info_failed eif;
2886 eif.failed = false;
2887 eif.info = info;
2888 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2889 (PTR) &eif);
2890 if (eif.failed)
2891 return false;
2894 /* Attach all the symbols to their version information. */
2895 asvinfo.output_bfd = output_bfd;
2896 asvinfo.info = info;
2897 asvinfo.verdefs = verdefs;
2898 asvinfo.export_dynamic = export_dynamic;
2899 asvinfo.failed = false;
2901 elf_link_hash_traverse (elf_hash_table (info),
2902 elf_link_assign_sym_version,
2903 (PTR) &asvinfo);
2904 if (asvinfo.failed)
2905 return false;
2907 /* Find all symbols which were defined in a dynamic object and make
2908 the backend pick a reasonable value for them. */
2909 eif.failed = false;
2910 eif.info = info;
2911 elf_link_hash_traverse (elf_hash_table (info),
2912 elf_adjust_dynamic_symbol,
2913 (PTR) &eif);
2914 if (eif.failed)
2915 return false;
2917 /* Add some entries to the .dynamic section. We fill in some of the
2918 values later, in elf_bfd_final_link, but we must add the entries
2919 now so that we know the final size of the .dynamic section. */
2921 /* If there are initialization and/or finalization functions to
2922 call then add the corresponding DT_INIT/DT_FINI entries. */
2923 h = (info->init_function
2924 ? elf_link_hash_lookup (elf_hash_table (info),
2925 info->init_function, false,
2926 false, false)
2927 : NULL);
2928 if (h != NULL
2929 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2930 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2932 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2933 return false;
2935 h = (info->fini_function
2936 ? elf_link_hash_lookup (elf_hash_table (info),
2937 info->fini_function, false,
2938 false, false)
2939 : NULL);
2940 if (h != NULL
2941 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2942 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2944 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2945 return false;
2948 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2949 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2950 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2951 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2952 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2953 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2954 sizeof (Elf_External_Sym)))
2955 return false;
2958 /* The backend must work out the sizes of all the other dynamic
2959 sections. */
2960 if (bed->elf_backend_size_dynamic_sections
2961 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2962 return false;
2964 if (elf_hash_table (info)->dynamic_sections_created)
2966 size_t dynsymcount;
2967 asection *s;
2968 size_t bucketcount = 0;
2969 Elf_Internal_Sym isym;
2970 size_t hash_entry_size;
2972 /* Set up the version definition section. */
2973 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2974 BFD_ASSERT (s != NULL);
2976 /* We may have created additional version definitions if we are
2977 just linking a regular application. */
2978 verdefs = asvinfo.verdefs;
2980 if (verdefs == NULL)
2981 _bfd_strip_section_from_output (info, s);
2982 else
2984 unsigned int cdefs;
2985 bfd_size_type size;
2986 struct bfd_elf_version_tree *t;
2987 bfd_byte *p;
2988 Elf_Internal_Verdef def;
2989 Elf_Internal_Verdaux defaux;
2991 cdefs = 0;
2992 size = 0;
2994 /* Make space for the base version. */
2995 size += sizeof (Elf_External_Verdef);
2996 size += sizeof (Elf_External_Verdaux);
2997 ++cdefs;
2999 for (t = verdefs; t != NULL; t = t->next)
3001 struct bfd_elf_version_deps *n;
3003 size += sizeof (Elf_External_Verdef);
3004 size += sizeof (Elf_External_Verdaux);
3005 ++cdefs;
3007 for (n = t->deps; n != NULL; n = n->next)
3008 size += sizeof (Elf_External_Verdaux);
3011 s->_raw_size = size;
3012 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3013 if (s->contents == NULL && s->_raw_size != 0)
3014 return false;
3016 /* Fill in the version definition section. */
3018 p = s->contents;
3020 def.vd_version = VER_DEF_CURRENT;
3021 def.vd_flags = VER_FLG_BASE;
3022 def.vd_ndx = 1;
3023 def.vd_cnt = 1;
3024 def.vd_aux = sizeof (Elf_External_Verdef);
3025 def.vd_next = (sizeof (Elf_External_Verdef)
3026 + sizeof (Elf_External_Verdaux));
3028 if (soname_indx != (bfd_size_type) -1)
3030 def.vd_hash = bfd_elf_hash (soname);
3031 defaux.vda_name = soname_indx;
3033 else
3035 const char *name;
3036 bfd_size_type indx;
3038 name = output_bfd->filename;
3039 def.vd_hash = bfd_elf_hash (name);
3040 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3041 name, true, false);
3042 if (indx == (bfd_size_type) -1)
3043 return false;
3044 defaux.vda_name = indx;
3046 defaux.vda_next = 0;
3048 _bfd_elf_swap_verdef_out (output_bfd, &def,
3049 (Elf_External_Verdef *)p);
3050 p += sizeof (Elf_External_Verdef);
3051 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3052 (Elf_External_Verdaux *) p);
3053 p += sizeof (Elf_External_Verdaux);
3055 for (t = verdefs; t != NULL; t = t->next)
3057 unsigned int cdeps;
3058 struct bfd_elf_version_deps *n;
3059 struct elf_link_hash_entry *h;
3061 cdeps = 0;
3062 for (n = t->deps; n != NULL; n = n->next)
3063 ++cdeps;
3065 /* Add a symbol representing this version. */
3066 h = NULL;
3067 if (! (_bfd_generic_link_add_one_symbol
3068 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3069 (bfd_vma) 0, (const char *) NULL, false,
3070 get_elf_backend_data (dynobj)->collect,
3071 (struct bfd_link_hash_entry **) &h)))
3072 return false;
3073 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3074 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3075 h->type = STT_OBJECT;
3076 h->verinfo.vertree = t;
3078 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3079 return false;
3081 def.vd_version = VER_DEF_CURRENT;
3082 def.vd_flags = 0;
3083 if (t->globals == NULL && t->locals == NULL && ! t->used)
3084 def.vd_flags |= VER_FLG_WEAK;
3085 def.vd_ndx = t->vernum + 1;
3086 def.vd_cnt = cdeps + 1;
3087 def.vd_hash = bfd_elf_hash (t->name);
3088 def.vd_aux = sizeof (Elf_External_Verdef);
3089 if (t->next != NULL)
3090 def.vd_next = (sizeof (Elf_External_Verdef)
3091 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3092 else
3093 def.vd_next = 0;
3095 _bfd_elf_swap_verdef_out (output_bfd, &def,
3096 (Elf_External_Verdef *) p);
3097 p += sizeof (Elf_External_Verdef);
3099 defaux.vda_name = h->dynstr_index;
3100 if (t->deps == NULL)
3101 defaux.vda_next = 0;
3102 else
3103 defaux.vda_next = sizeof (Elf_External_Verdaux);
3104 t->name_indx = defaux.vda_name;
3106 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3107 (Elf_External_Verdaux *) p);
3108 p += sizeof (Elf_External_Verdaux);
3110 for (n = t->deps; n != NULL; n = n->next)
3112 if (n->version_needed == NULL)
3114 /* This can happen if there was an error in the
3115 version script. */
3116 defaux.vda_name = 0;
3118 else
3119 defaux.vda_name = n->version_needed->name_indx;
3120 if (n->next == NULL)
3121 defaux.vda_next = 0;
3122 else
3123 defaux.vda_next = sizeof (Elf_External_Verdaux);
3125 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3126 (Elf_External_Verdaux *) p);
3127 p += sizeof (Elf_External_Verdaux);
3131 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3132 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3133 return false;
3135 elf_tdata (output_bfd)->cverdefs = cdefs;
3138 /* Work out the size of the version reference section. */
3140 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3141 BFD_ASSERT (s != NULL);
3143 struct elf_find_verdep_info sinfo;
3145 sinfo.output_bfd = output_bfd;
3146 sinfo.info = info;
3147 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3148 if (sinfo.vers == 0)
3149 sinfo.vers = 1;
3150 sinfo.failed = false;
3152 elf_link_hash_traverse (elf_hash_table (info),
3153 elf_link_find_version_dependencies,
3154 (PTR) &sinfo);
3156 if (elf_tdata (output_bfd)->verref == NULL)
3157 _bfd_strip_section_from_output (info, s);
3158 else
3160 Elf_Internal_Verneed *t;
3161 unsigned int size;
3162 unsigned int crefs;
3163 bfd_byte *p;
3165 /* Build the version definition section. */
3166 size = 0;
3167 crefs = 0;
3168 for (t = elf_tdata (output_bfd)->verref;
3169 t != NULL;
3170 t = t->vn_nextref)
3172 Elf_Internal_Vernaux *a;
3174 size += sizeof (Elf_External_Verneed);
3175 ++crefs;
3176 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3177 size += sizeof (Elf_External_Vernaux);
3180 s->_raw_size = size;
3181 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3182 if (s->contents == NULL)
3183 return false;
3185 p = s->contents;
3186 for (t = elf_tdata (output_bfd)->verref;
3187 t != NULL;
3188 t = t->vn_nextref)
3190 unsigned int caux;
3191 Elf_Internal_Vernaux *a;
3192 bfd_size_type indx;
3194 caux = 0;
3195 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3196 ++caux;
3198 t->vn_version = VER_NEED_CURRENT;
3199 t->vn_cnt = caux;
3200 if (elf_dt_name (t->vn_bfd) != NULL)
3201 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3202 elf_dt_name (t->vn_bfd),
3203 true, false);
3204 else
3205 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3206 t->vn_bfd->filename, true, false);
3207 if (indx == (bfd_size_type) -1)
3208 return false;
3209 t->vn_file = indx;
3210 t->vn_aux = sizeof (Elf_External_Verneed);
3211 if (t->vn_nextref == NULL)
3212 t->vn_next = 0;
3213 else
3214 t->vn_next = (sizeof (Elf_External_Verneed)
3215 + caux * sizeof (Elf_External_Vernaux));
3217 _bfd_elf_swap_verneed_out (output_bfd, t,
3218 (Elf_External_Verneed *) p);
3219 p += sizeof (Elf_External_Verneed);
3221 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3223 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3224 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3225 a->vna_nodename, true, false);
3226 if (indx == (bfd_size_type) -1)
3227 return false;
3228 a->vna_name = indx;
3229 if (a->vna_nextptr == NULL)
3230 a->vna_next = 0;
3231 else
3232 a->vna_next = sizeof (Elf_External_Vernaux);
3234 _bfd_elf_swap_vernaux_out (output_bfd, a,
3235 (Elf_External_Vernaux *) p);
3236 p += sizeof (Elf_External_Vernaux);
3240 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3241 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3242 return false;
3244 elf_tdata (output_bfd)->cverrefs = crefs;
3248 /* Assign dynsym indicies. In a shared library we generate a
3249 section symbol for each output section, which come first.
3250 Next come all of the back-end allocated local dynamic syms,
3251 followed by the rest of the global symbols. */
3253 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3255 /* Work out the size of the symbol version section. */
3256 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3257 BFD_ASSERT (s != NULL);
3258 if (dynsymcount == 0
3259 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3261 _bfd_strip_section_from_output (info, s);
3262 /* The DYNSYMCOUNT might have changed if we were going to
3263 output a dynamic symbol table entry for S. */
3264 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3266 else
3268 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3269 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3270 if (s->contents == NULL)
3271 return false;
3273 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3274 return false;
3277 /* Set the size of the .dynsym and .hash sections. We counted
3278 the number of dynamic symbols in elf_link_add_object_symbols.
3279 We will build the contents of .dynsym and .hash when we build
3280 the final symbol table, because until then we do not know the
3281 correct value to give the symbols. We built the .dynstr
3282 section as we went along in elf_link_add_object_symbols. */
3283 s = bfd_get_section_by_name (dynobj, ".dynsym");
3284 BFD_ASSERT (s != NULL);
3285 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3286 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3287 if (s->contents == NULL && s->_raw_size != 0)
3288 return false;
3290 /* The first entry in .dynsym is a dummy symbol. */
3291 isym.st_value = 0;
3292 isym.st_size = 0;
3293 isym.st_name = 0;
3294 isym.st_info = 0;
3295 isym.st_other = 0;
3296 isym.st_shndx = 0;
3297 elf_swap_symbol_out (output_bfd, &isym,
3298 (PTR) (Elf_External_Sym *) s->contents);
3300 /* Compute the size of the hashing table. As a side effect this
3301 computes the hash values for all the names we export. */
3302 bucketcount = compute_bucket_count (info);
3304 s = bfd_get_section_by_name (dynobj, ".hash");
3305 BFD_ASSERT (s != NULL);
3306 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3307 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3308 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3309 if (s->contents == NULL)
3310 return false;
3311 memset (s->contents, 0, (size_t) s->_raw_size);
3313 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3314 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3315 s->contents + hash_entry_size);
3317 elf_hash_table (info)->bucketcount = bucketcount;
3319 s = bfd_get_section_by_name (dynobj, ".dynstr");
3320 BFD_ASSERT (s != NULL);
3321 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3323 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3324 return false;
3327 return true;
3330 /* Fix up the flags for a symbol. This handles various cases which
3331 can only be fixed after all the input files are seen. This is
3332 currently called by both adjust_dynamic_symbol and
3333 assign_sym_version, which is unnecessary but perhaps more robust in
3334 the face of future changes. */
3336 static boolean
3337 elf_fix_symbol_flags (h, eif)
3338 struct elf_link_hash_entry *h;
3339 struct elf_info_failed *eif;
3341 /* If this symbol was mentioned in a non-ELF file, try to set
3342 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3343 permit a non-ELF file to correctly refer to a symbol defined in
3344 an ELF dynamic object. */
3345 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3347 while (h->root.type == bfd_link_hash_indirect)
3348 h = (struct elf_link_hash_entry *) h->root.u.i.link;
3350 if (h->root.type != bfd_link_hash_defined
3351 && h->root.type != bfd_link_hash_defweak)
3352 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3353 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3354 else
3356 if (h->root.u.def.section->owner != NULL
3357 && (bfd_get_flavour (h->root.u.def.section->owner)
3358 == bfd_target_elf_flavour))
3359 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3360 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3361 else
3362 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3365 if (h->dynindx == -1
3366 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3367 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3369 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3371 eif->failed = true;
3372 return false;
3376 else
3378 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3379 was first seen in a non-ELF file. Fortunately, if the symbol
3380 was first seen in an ELF file, we're probably OK unless the
3381 symbol was defined in a non-ELF file. Catch that case here.
3382 FIXME: We're still in trouble if the symbol was first seen in
3383 a dynamic object, and then later in a non-ELF regular object. */
3384 if ((h->root.type == bfd_link_hash_defined
3385 || h->root.type == bfd_link_hash_defweak)
3386 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3387 && (h->root.u.def.section->owner != NULL
3388 ? (bfd_get_flavour (h->root.u.def.section->owner)
3389 != bfd_target_elf_flavour)
3390 : (bfd_is_abs_section (h->root.u.def.section)
3391 && (h->elf_link_hash_flags
3392 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3393 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3396 /* If this is a final link, and the symbol was defined as a common
3397 symbol in a regular object file, and there was no definition in
3398 any dynamic object, then the linker will have allocated space for
3399 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3400 flag will not have been set. */
3401 if (h->root.type == bfd_link_hash_defined
3402 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3403 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3404 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3405 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3406 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3408 /* If -Bsymbolic was used (which means to bind references to global
3409 symbols to the definition within the shared object), and this
3410 symbol was defined in a regular object, then it actually doesn't
3411 need a PLT entry. Likewise, if the symbol has any kind of
3412 visibility (internal, hidden, or protected), it doesn't need a
3413 PLT. */
3414 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3415 && eif->info->shared
3416 && (eif->info->symbolic || ELF_ST_VISIBILITY (h->other))
3417 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3419 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3420 h->plt.offset = (bfd_vma) -1;
3423 /* If this is a weak defined symbol in a dynamic object, and we know
3424 the real definition in the dynamic object, copy interesting flags
3425 over to the real definition. */
3426 if (h->weakdef != NULL)
3428 struct elf_link_hash_entry *weakdef;
3430 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3431 || h->root.type == bfd_link_hash_defweak);
3432 weakdef = h->weakdef;
3433 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3434 || weakdef->root.type == bfd_link_hash_defweak);
3435 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3437 /* If the real definition is defined by a regular object file,
3438 don't do anything special. See the longer description in
3439 elf_adjust_dynamic_symbol, below. */
3440 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3441 h->weakdef = NULL;
3442 else
3443 weakdef->elf_link_hash_flags |=
3444 (h->elf_link_hash_flags
3445 & (ELF_LINK_HASH_REF_REGULAR
3446 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3447 | ELF_LINK_NON_GOT_REF));
3450 return true;
3453 /* Make the backend pick a good value for a dynamic symbol. This is
3454 called via elf_link_hash_traverse, and also calls itself
3455 recursively. */
3457 static boolean
3458 elf_adjust_dynamic_symbol (h, data)
3459 struct elf_link_hash_entry *h;
3460 PTR data;
3462 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3463 bfd *dynobj;
3464 struct elf_backend_data *bed;
3466 /* Ignore indirect symbols. These are added by the versioning code. */
3467 if (h->root.type == bfd_link_hash_indirect)
3468 return true;
3470 /* Fix the symbol flags. */
3471 if (! elf_fix_symbol_flags (h, eif))
3472 return false;
3474 /* If this symbol does not require a PLT entry, and it is not
3475 defined by a dynamic object, or is not referenced by a regular
3476 object, ignore it. We do have to handle a weak defined symbol,
3477 even if no regular object refers to it, if we decided to add it
3478 to the dynamic symbol table. FIXME: Do we normally need to worry
3479 about symbols which are defined by one dynamic object and
3480 referenced by another one? */
3481 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3482 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3483 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3484 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3485 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3487 h->plt.offset = (bfd_vma) -1;
3488 return true;
3491 /* If we've already adjusted this symbol, don't do it again. This
3492 can happen via a recursive call. */
3493 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3494 return true;
3496 /* Don't look at this symbol again. Note that we must set this
3497 after checking the above conditions, because we may look at a
3498 symbol once, decide not to do anything, and then get called
3499 recursively later after REF_REGULAR is set below. */
3500 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3502 /* If this is a weak definition, and we know a real definition, and
3503 the real symbol is not itself defined by a regular object file,
3504 then get a good value for the real definition. We handle the
3505 real symbol first, for the convenience of the backend routine.
3507 Note that there is a confusing case here. If the real definition
3508 is defined by a regular object file, we don't get the real symbol
3509 from the dynamic object, but we do get the weak symbol. If the
3510 processor backend uses a COPY reloc, then if some routine in the
3511 dynamic object changes the real symbol, we will not see that
3512 change in the corresponding weak symbol. This is the way other
3513 ELF linkers work as well, and seems to be a result of the shared
3514 library model.
3516 I will clarify this issue. Most SVR4 shared libraries define the
3517 variable _timezone and define timezone as a weak synonym. The
3518 tzset call changes _timezone. If you write
3519 extern int timezone;
3520 int _timezone = 5;
3521 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3522 you might expect that, since timezone is a synonym for _timezone,
3523 the same number will print both times. However, if the processor
3524 backend uses a COPY reloc, then actually timezone will be copied
3525 into your process image, and, since you define _timezone
3526 yourself, _timezone will not. Thus timezone and _timezone will
3527 wind up at different memory locations. The tzset call will set
3528 _timezone, leaving timezone unchanged. */
3530 if (h->weakdef != NULL)
3532 /* If we get to this point, we know there is an implicit
3533 reference by a regular object file via the weak symbol H.
3534 FIXME: Is this really true? What if the traversal finds
3535 H->WEAKDEF before it finds H? */
3536 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3538 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3539 return false;
3542 /* If a symbol has no type and no size and does not require a PLT
3543 entry, then we are probably about to do the wrong thing here: we
3544 are probably going to create a COPY reloc for an empty object.
3545 This case can arise when a shared object is built with assembly
3546 code, and the assembly code fails to set the symbol type. */
3547 if (h->size == 0
3548 && h->type == STT_NOTYPE
3549 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3550 (*_bfd_error_handler)
3551 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3552 h->root.root.string);
3554 dynobj = elf_hash_table (eif->info)->dynobj;
3555 bed = get_elf_backend_data (dynobj);
3556 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3558 eif->failed = true;
3559 return false;
3562 return true;
3565 /* This routine is used to export all defined symbols into the dynamic
3566 symbol table. It is called via elf_link_hash_traverse. */
3568 static boolean
3569 elf_export_symbol (h, data)
3570 struct elf_link_hash_entry *h;
3571 PTR data;
3573 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3575 /* Ignore indirect symbols. These are added by the versioning code. */
3576 if (h->root.type == bfd_link_hash_indirect)
3577 return true;
3579 if (h->dynindx == -1
3580 && (h->elf_link_hash_flags
3581 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3583 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3585 eif->failed = true;
3586 return false;
3590 return true;
3593 /* Look through the symbols which are defined in other shared
3594 libraries and referenced here. Update the list of version
3595 dependencies. This will be put into the .gnu.version_r section.
3596 This function is called via elf_link_hash_traverse. */
3598 static boolean
3599 elf_link_find_version_dependencies (h, data)
3600 struct elf_link_hash_entry *h;
3601 PTR data;
3603 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3604 Elf_Internal_Verneed *t;
3605 Elf_Internal_Vernaux *a;
3607 /* We only care about symbols defined in shared objects with version
3608 information. */
3609 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3610 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3611 || h->dynindx == -1
3612 || h->verinfo.verdef == NULL)
3613 return true;
3615 /* See if we already know about this version. */
3616 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3618 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3619 continue;
3621 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3622 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3623 return true;
3625 break;
3628 /* This is a new version. Add it to tree we are building. */
3630 if (t == NULL)
3632 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3633 if (t == NULL)
3635 rinfo->failed = true;
3636 return false;
3639 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3640 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3641 elf_tdata (rinfo->output_bfd)->verref = t;
3644 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3646 /* Note that we are copying a string pointer here, and testing it
3647 above. If bfd_elf_string_from_elf_section is ever changed to
3648 discard the string data when low in memory, this will have to be
3649 fixed. */
3650 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3652 a->vna_flags = h->verinfo.verdef->vd_flags;
3653 a->vna_nextptr = t->vn_auxptr;
3655 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3656 ++rinfo->vers;
3658 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3660 t->vn_auxptr = a;
3662 return true;
3665 /* Figure out appropriate versions for all the symbols. We may not
3666 have the version number script until we have read all of the input
3667 files, so until that point we don't know which symbols should be
3668 local. This function is called via elf_link_hash_traverse. */
3670 static boolean
3671 elf_link_assign_sym_version (h, data)
3672 struct elf_link_hash_entry *h;
3673 PTR data;
3675 struct elf_assign_sym_version_info *sinfo =
3676 (struct elf_assign_sym_version_info *) data;
3677 struct bfd_link_info *info = sinfo->info;
3678 struct elf_backend_data *bed;
3679 struct elf_info_failed eif;
3680 char *p;
3682 /* Fix the symbol flags. */
3683 eif.failed = false;
3684 eif.info = info;
3685 if (! elf_fix_symbol_flags (h, &eif))
3687 if (eif.failed)
3688 sinfo->failed = true;
3689 return false;
3692 /* We only need version numbers for symbols defined in regular
3693 objects. */
3694 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3695 return true;
3697 bed = get_elf_backend_data (sinfo->output_bfd);
3698 p = strchr (h->root.root.string, ELF_VER_CHR);
3699 if (p != NULL && h->verinfo.vertree == NULL)
3701 struct bfd_elf_version_tree *t;
3702 boolean hidden;
3704 hidden = true;
3706 /* There are two consecutive ELF_VER_CHR characters if this is
3707 not a hidden symbol. */
3708 ++p;
3709 if (*p == ELF_VER_CHR)
3711 hidden = false;
3712 ++p;
3715 /* If there is no version string, we can just return out. */
3716 if (*p == '\0')
3718 if (hidden)
3719 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3720 return true;
3723 /* Look for the version. If we find it, it is no longer weak. */
3724 for (t = sinfo->verdefs; t != NULL; t = t->next)
3726 if (strcmp (t->name, p) == 0)
3728 int len;
3729 char *alc;
3730 struct bfd_elf_version_expr *d;
3732 len = p - h->root.root.string;
3733 alc = bfd_alloc (sinfo->output_bfd, len);
3734 if (alc == NULL)
3735 return false;
3736 strncpy (alc, h->root.root.string, len - 1);
3737 alc[len - 1] = '\0';
3738 if (alc[len - 2] == ELF_VER_CHR)
3739 alc[len - 2] = '\0';
3741 h->verinfo.vertree = t;
3742 t->used = true;
3743 d = NULL;
3745 if (t->globals != NULL)
3747 for (d = t->globals; d != NULL; d = d->next)
3748 if ((*d->match) (d, alc))
3749 break;
3752 /* See if there is anything to force this symbol to
3753 local scope. */
3754 if (d == NULL && t->locals != NULL)
3756 for (d = t->locals; d != NULL; d = d->next)
3758 if ((*d->match) (d, alc))
3760 if (h->dynindx != -1
3761 && info->shared
3762 && ! sinfo->export_dynamic)
3764 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3765 (*bed->elf_backend_hide_symbol) (info, h);
3766 /* FIXME: The name of the symbol has
3767 already been recorded in the dynamic
3768 string table section. */
3771 break;
3776 bfd_release (sinfo->output_bfd, alc);
3777 break;
3781 /* If we are building an application, we need to create a
3782 version node for this version. */
3783 if (t == NULL && ! info->shared)
3785 struct bfd_elf_version_tree **pp;
3786 int version_index;
3788 /* If we aren't going to export this symbol, we don't need
3789 to worry about it. */
3790 if (h->dynindx == -1)
3791 return true;
3793 t = ((struct bfd_elf_version_tree *)
3794 bfd_alloc (sinfo->output_bfd, sizeof *t));
3795 if (t == NULL)
3797 sinfo->failed = true;
3798 return false;
3801 t->next = NULL;
3802 t->name = p;
3803 t->globals = NULL;
3804 t->locals = NULL;
3805 t->deps = NULL;
3806 t->name_indx = (unsigned int) -1;
3807 t->used = true;
3809 version_index = 1;
3810 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3811 ++version_index;
3812 t->vernum = version_index;
3814 *pp = t;
3816 h->verinfo.vertree = t;
3818 else if (t == NULL)
3820 /* We could not find the version for a symbol when
3821 generating a shared archive. Return an error. */
3822 (*_bfd_error_handler)
3823 (_("%s: undefined versioned symbol name %s"),
3824 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3825 bfd_set_error (bfd_error_bad_value);
3826 sinfo->failed = true;
3827 return false;
3830 if (hidden)
3831 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3834 /* If we don't have a version for this symbol, see if we can find
3835 something. */
3836 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3838 struct bfd_elf_version_tree *t;
3839 struct bfd_elf_version_tree *deflt;
3840 struct bfd_elf_version_expr *d;
3842 /* See if can find what version this symbol is in. If the
3843 symbol is supposed to be local, then don't actually register
3844 it. */
3845 deflt = NULL;
3846 for (t = sinfo->verdefs; t != NULL; t = t->next)
3848 if (t->globals != NULL)
3850 for (d = t->globals; d != NULL; d = d->next)
3852 if ((*d->match) (d, h->root.root.string))
3854 h->verinfo.vertree = t;
3855 break;
3859 if (d != NULL)
3860 break;
3863 if (t->locals != NULL)
3865 for (d = t->locals; d != NULL; d = d->next)
3867 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3868 deflt = t;
3869 else if ((*d->match) (d, h->root.root.string))
3871 h->verinfo.vertree = t;
3872 if (h->dynindx != -1
3873 && info->shared
3874 && ! sinfo->export_dynamic)
3876 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3877 (*bed->elf_backend_hide_symbol) (info, h);
3878 /* FIXME: The name of the symbol has already
3879 been recorded in the dynamic string table
3880 section. */
3882 break;
3886 if (d != NULL)
3887 break;
3891 if (deflt != NULL && h->verinfo.vertree == NULL)
3893 h->verinfo.vertree = deflt;
3894 if (h->dynindx != -1
3895 && info->shared
3896 && ! sinfo->export_dynamic)
3898 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3899 (*bed->elf_backend_hide_symbol) (info, h);
3900 /* FIXME: The name of the symbol has already been
3901 recorded in the dynamic string table section. */
3906 return true;
3909 /* Final phase of ELF linker. */
3911 /* A structure we use to avoid passing large numbers of arguments. */
3913 struct elf_final_link_info
3915 /* General link information. */
3916 struct bfd_link_info *info;
3917 /* Output BFD. */
3918 bfd *output_bfd;
3919 /* Symbol string table. */
3920 struct bfd_strtab_hash *symstrtab;
3921 /* .dynsym section. */
3922 asection *dynsym_sec;
3923 /* .hash section. */
3924 asection *hash_sec;
3925 /* symbol version section (.gnu.version). */
3926 asection *symver_sec;
3927 /* Buffer large enough to hold contents of any section. */
3928 bfd_byte *contents;
3929 /* Buffer large enough to hold external relocs of any section. */
3930 PTR external_relocs;
3931 /* Buffer large enough to hold internal relocs of any section. */
3932 Elf_Internal_Rela *internal_relocs;
3933 /* Buffer large enough to hold external local symbols of any input
3934 BFD. */
3935 Elf_External_Sym *external_syms;
3936 /* Buffer large enough to hold internal local symbols of any input
3937 BFD. */
3938 Elf_Internal_Sym *internal_syms;
3939 /* Array large enough to hold a symbol index for each local symbol
3940 of any input BFD. */
3941 long *indices;
3942 /* Array large enough to hold a section pointer for each local
3943 symbol of any input BFD. */
3944 asection **sections;
3945 /* Buffer to hold swapped out symbols. */
3946 Elf_External_Sym *symbuf;
3947 /* Number of swapped out symbols in buffer. */
3948 size_t symbuf_count;
3949 /* Number of symbols which fit in symbuf. */
3950 size_t symbuf_size;
3953 static boolean elf_link_output_sym
3954 PARAMS ((struct elf_final_link_info *, const char *,
3955 Elf_Internal_Sym *, asection *));
3956 static boolean elf_link_flush_output_syms
3957 PARAMS ((struct elf_final_link_info *));
3958 static boolean elf_link_output_extsym
3959 PARAMS ((struct elf_link_hash_entry *, PTR));
3960 static boolean elf_link_input_bfd
3961 PARAMS ((struct elf_final_link_info *, bfd *));
3962 static boolean elf_reloc_link_order
3963 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3964 struct bfd_link_order *));
3966 /* This struct is used to pass information to elf_link_output_extsym. */
3968 struct elf_outext_info
3970 boolean failed;
3971 boolean localsyms;
3972 struct elf_final_link_info *finfo;
3975 /* Compute the size of, and allocate space for, REL_HDR which is the
3976 section header for a section containing relocations for O. */
3978 static boolean
3979 elf_link_size_reloc_section (abfd, rel_hdr, o)
3980 bfd *abfd;
3981 Elf_Internal_Shdr *rel_hdr;
3982 asection *o;
3984 register struct elf_link_hash_entry **p, **pend;
3985 unsigned reloc_count;
3987 /* Figure out how many relocations there will be. */
3988 if (rel_hdr == &elf_section_data (o)->rel_hdr)
3989 reloc_count = elf_section_data (o)->rel_count;
3990 else
3991 reloc_count = elf_section_data (o)->rel_count2;
3993 /* That allows us to calculate the size of the section. */
3994 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
3996 /* The contents field must last into write_object_contents, so we
3997 allocate it with bfd_alloc rather than malloc. */
3998 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
3999 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
4000 return false;
4002 /* We only allocate one set of hash entries, so we only do it the
4003 first time we are called. */
4004 if (elf_section_data (o)->rel_hashes == NULL)
4006 p = ((struct elf_link_hash_entry **)
4007 bfd_malloc (o->reloc_count
4008 * sizeof (struct elf_link_hash_entry *)));
4009 if (p == NULL && o->reloc_count != 0)
4010 return false;
4012 elf_section_data (o)->rel_hashes = p;
4013 pend = p + o->reloc_count;
4014 for (; p < pend; p++)
4015 *p = NULL;
4018 return true;
4021 /* When performing a relocateable link, the input relocations are
4022 preserved. But, if they reference global symbols, the indices
4023 referenced must be updated. Update all the relocations in
4024 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
4026 static void
4027 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
4028 bfd *abfd;
4029 Elf_Internal_Shdr *rel_hdr;
4030 unsigned int count;
4031 struct elf_link_hash_entry **rel_hash;
4033 unsigned int i;
4034 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4036 for (i = 0; i < count; i++, rel_hash++)
4038 if (*rel_hash == NULL)
4039 continue;
4041 BFD_ASSERT ((*rel_hash)->indx >= 0);
4043 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4045 Elf_External_Rel *erel;
4046 Elf_Internal_Rel irel;
4048 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4049 if (bed->s->swap_reloc_in)
4050 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, &irel);
4051 else
4052 elf_swap_reloc_in (abfd, erel, &irel);
4053 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4054 ELF_R_TYPE (irel.r_info));
4055 if (bed->s->swap_reloc_out)
4056 (*bed->s->swap_reloc_out) (abfd, &irel, (bfd_byte *) erel);
4057 else
4058 elf_swap_reloc_out (abfd, &irel, erel);
4060 else
4062 Elf_External_Rela *erela;
4063 Elf_Internal_Rela irela;
4065 BFD_ASSERT (rel_hdr->sh_entsize
4066 == sizeof (Elf_External_Rela));
4068 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4069 if (bed->s->swap_reloca_in)
4070 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, &irela);
4071 else
4072 elf_swap_reloca_in (abfd, erela, &irela);
4073 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4074 ELF_R_TYPE (irela.r_info));
4075 if (bed->s->swap_reloca_out)
4076 (*bed->s->swap_reloca_out) (abfd, &irela, (bfd_byte *) erela);
4077 else
4078 elf_swap_reloca_out (abfd, &irela, erela);
4083 /* Do the final step of an ELF link. */
4085 boolean
4086 elf_bfd_final_link (abfd, info)
4087 bfd *abfd;
4088 struct bfd_link_info *info;
4090 boolean dynamic;
4091 bfd *dynobj;
4092 struct elf_final_link_info finfo;
4093 register asection *o;
4094 register struct bfd_link_order *p;
4095 register bfd *sub;
4096 size_t max_contents_size;
4097 size_t max_external_reloc_size;
4098 size_t max_internal_reloc_count;
4099 size_t max_sym_count;
4100 file_ptr off;
4101 Elf_Internal_Sym elfsym;
4102 unsigned int i;
4103 Elf_Internal_Shdr *symtab_hdr;
4104 Elf_Internal_Shdr *symstrtab_hdr;
4105 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4106 struct elf_outext_info eoinfo;
4108 if (info->shared)
4109 abfd->flags |= DYNAMIC;
4111 dynamic = elf_hash_table (info)->dynamic_sections_created;
4112 dynobj = elf_hash_table (info)->dynobj;
4114 finfo.info = info;
4115 finfo.output_bfd = abfd;
4116 finfo.symstrtab = elf_stringtab_init ();
4117 if (finfo.symstrtab == NULL)
4118 return false;
4120 if (! dynamic)
4122 finfo.dynsym_sec = NULL;
4123 finfo.hash_sec = NULL;
4124 finfo.symver_sec = NULL;
4126 else
4128 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4129 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4130 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4131 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4132 /* Note that it is OK if symver_sec is NULL. */
4135 finfo.contents = NULL;
4136 finfo.external_relocs = NULL;
4137 finfo.internal_relocs = NULL;
4138 finfo.external_syms = NULL;
4139 finfo.internal_syms = NULL;
4140 finfo.indices = NULL;
4141 finfo.sections = NULL;
4142 finfo.symbuf = NULL;
4143 finfo.symbuf_count = 0;
4145 /* Count up the number of relocations we will output for each output
4146 section, so that we know the sizes of the reloc sections. We
4147 also figure out some maximum sizes. */
4148 max_contents_size = 0;
4149 max_external_reloc_size = 0;
4150 max_internal_reloc_count = 0;
4151 max_sym_count = 0;
4152 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4154 o->reloc_count = 0;
4156 for (p = o->link_order_head; p != NULL; p = p->next)
4158 if (p->type == bfd_section_reloc_link_order
4159 || p->type == bfd_symbol_reloc_link_order)
4160 ++o->reloc_count;
4161 else if (p->type == bfd_indirect_link_order)
4163 asection *sec;
4165 sec = p->u.indirect.section;
4167 /* Mark all sections which are to be included in the
4168 link. This will normally be every section. We need
4169 to do this so that we can identify any sections which
4170 the linker has decided to not include. */
4171 sec->linker_mark = true;
4173 if (info->relocateable || info->emitrelocations)
4174 o->reloc_count += sec->reloc_count;
4176 if (sec->_raw_size > max_contents_size)
4177 max_contents_size = sec->_raw_size;
4178 if (sec->_cooked_size > max_contents_size)
4179 max_contents_size = sec->_cooked_size;
4181 /* We are interested in just local symbols, not all
4182 symbols. */
4183 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4184 && (sec->owner->flags & DYNAMIC) == 0)
4186 size_t sym_count;
4188 if (elf_bad_symtab (sec->owner))
4189 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4190 / sizeof (Elf_External_Sym));
4191 else
4192 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4194 if (sym_count > max_sym_count)
4195 max_sym_count = sym_count;
4197 if ((sec->flags & SEC_RELOC) != 0)
4199 size_t ext_size;
4201 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4202 if (ext_size > max_external_reloc_size)
4203 max_external_reloc_size = ext_size;
4204 if (sec->reloc_count > max_internal_reloc_count)
4205 max_internal_reloc_count = sec->reloc_count;
4211 if (o->reloc_count > 0)
4212 o->flags |= SEC_RELOC;
4213 else
4215 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4216 set it (this is probably a bug) and if it is set
4217 assign_section_numbers will create a reloc section. */
4218 o->flags &=~ SEC_RELOC;
4221 /* If the SEC_ALLOC flag is not set, force the section VMA to
4222 zero. This is done in elf_fake_sections as well, but forcing
4223 the VMA to 0 here will ensure that relocs against these
4224 sections are handled correctly. */
4225 if ((o->flags & SEC_ALLOC) == 0
4226 && ! o->user_set_vma)
4227 o->vma = 0;
4230 /* Figure out the file positions for everything but the symbol table
4231 and the relocs. We set symcount to force assign_section_numbers
4232 to create a symbol table. */
4233 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4234 BFD_ASSERT (! abfd->output_has_begun);
4235 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4236 goto error_return;
4238 /* Figure out how many relocations we will have in each section.
4239 Just using RELOC_COUNT isn't good enough since that doesn't
4240 maintain a separate value for REL vs. RELA relocations. */
4241 if (info->relocateable || info->emitrelocations)
4242 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4243 for (o = sub->sections; o != NULL; o = o->next)
4245 asection *output_section;
4247 if (! o->linker_mark)
4249 /* This section was omitted from the link. */
4250 continue;
4253 output_section = o->output_section;
4255 if (output_section != NULL
4256 && (o->flags & SEC_RELOC) != 0)
4258 struct bfd_elf_section_data *esdi
4259 = elf_section_data (o);
4260 struct bfd_elf_section_data *esdo
4261 = elf_section_data (output_section);
4262 unsigned int *rel_count;
4263 unsigned int *rel_count2;
4265 /* We must be careful to add the relocation froms the
4266 input section to the right output count. */
4267 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4269 rel_count = &esdo->rel_count;
4270 rel_count2 = &esdo->rel_count2;
4272 else
4274 rel_count = &esdo->rel_count2;
4275 rel_count2 = &esdo->rel_count;
4278 *rel_count += (esdi->rel_hdr.sh_size
4279 / esdi->rel_hdr.sh_entsize);
4280 if (esdi->rel_hdr2)
4281 *rel_count2 += (esdi->rel_hdr2->sh_size
4282 / esdi->rel_hdr2->sh_entsize);
4286 /* That created the reloc sections. Set their sizes, and assign
4287 them file positions, and allocate some buffers. */
4288 for (o = abfd->sections; o != NULL; o = o->next)
4290 if ((o->flags & SEC_RELOC) != 0)
4292 if (!elf_link_size_reloc_section (abfd,
4293 &elf_section_data (o)->rel_hdr,
4295 goto error_return;
4297 if (elf_section_data (o)->rel_hdr2
4298 && !elf_link_size_reloc_section (abfd,
4299 elf_section_data (o)->rel_hdr2,
4301 goto error_return;
4304 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4305 to count upwards while actually outputting the relocations. */
4306 elf_section_data (o)->rel_count = 0;
4307 elf_section_data (o)->rel_count2 = 0;
4310 _bfd_elf_assign_file_positions_for_relocs (abfd);
4312 /* We have now assigned file positions for all the sections except
4313 .symtab and .strtab. We start the .symtab section at the current
4314 file position, and write directly to it. We build the .strtab
4315 section in memory. */
4316 bfd_get_symcount (abfd) = 0;
4317 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4318 /* sh_name is set in prep_headers. */
4319 symtab_hdr->sh_type = SHT_SYMTAB;
4320 symtab_hdr->sh_flags = 0;
4321 symtab_hdr->sh_addr = 0;
4322 symtab_hdr->sh_size = 0;
4323 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4324 /* sh_link is set in assign_section_numbers. */
4325 /* sh_info is set below. */
4326 /* sh_offset is set just below. */
4327 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4329 off = elf_tdata (abfd)->next_file_pos;
4330 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4332 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4333 incorrect. We do not yet know the size of the .symtab section.
4334 We correct next_file_pos below, after we do know the size. */
4336 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4337 continuously seeking to the right position in the file. */
4338 if (! info->keep_memory || max_sym_count < 20)
4339 finfo.symbuf_size = 20;
4340 else
4341 finfo.symbuf_size = max_sym_count;
4342 finfo.symbuf = ((Elf_External_Sym *)
4343 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4344 if (finfo.symbuf == NULL)
4345 goto error_return;
4347 /* Start writing out the symbol table. The first symbol is always a
4348 dummy symbol. */
4349 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4351 elfsym.st_value = 0;
4352 elfsym.st_size = 0;
4353 elfsym.st_info = 0;
4354 elfsym.st_other = 0;
4355 elfsym.st_shndx = SHN_UNDEF;
4356 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4357 &elfsym, bfd_und_section_ptr))
4358 goto error_return;
4361 #if 0
4362 /* Some standard ELF linkers do this, but we don't because it causes
4363 bootstrap comparison failures. */
4364 /* Output a file symbol for the output file as the second symbol.
4365 We output this even if we are discarding local symbols, although
4366 I'm not sure if this is correct. */
4367 elfsym.st_value = 0;
4368 elfsym.st_size = 0;
4369 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4370 elfsym.st_other = 0;
4371 elfsym.st_shndx = SHN_ABS;
4372 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4373 &elfsym, bfd_abs_section_ptr))
4374 goto error_return;
4375 #endif
4377 /* Output a symbol for each section. We output these even if we are
4378 discarding local symbols, since they are used for relocs. These
4379 symbols have no names. We store the index of each one in the
4380 index field of the section, so that we can find it again when
4381 outputting relocs. */
4382 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4384 elfsym.st_size = 0;
4385 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4386 elfsym.st_other = 0;
4387 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4389 o = section_from_elf_index (abfd, i);
4390 if (o != NULL)
4391 o->target_index = bfd_get_symcount (abfd);
4392 elfsym.st_shndx = i;
4393 if (info->relocateable || o == NULL)
4394 elfsym.st_value = 0;
4395 else
4396 elfsym.st_value = o->vma;
4397 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4398 &elfsym, o))
4399 goto error_return;
4403 /* Allocate some memory to hold information read in from the input
4404 files. */
4405 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4406 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4407 finfo.internal_relocs = ((Elf_Internal_Rela *)
4408 bfd_malloc (max_internal_reloc_count
4409 * sizeof (Elf_Internal_Rela)
4410 * bed->s->int_rels_per_ext_rel));
4411 finfo.external_syms = ((Elf_External_Sym *)
4412 bfd_malloc (max_sym_count
4413 * sizeof (Elf_External_Sym)));
4414 finfo.internal_syms = ((Elf_Internal_Sym *)
4415 bfd_malloc (max_sym_count
4416 * sizeof (Elf_Internal_Sym)));
4417 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4418 finfo.sections = ((asection **)
4419 bfd_malloc (max_sym_count * sizeof (asection *)));
4420 if ((finfo.contents == NULL && max_contents_size != 0)
4421 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4422 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4423 || (finfo.external_syms == NULL && max_sym_count != 0)
4424 || (finfo.internal_syms == NULL && max_sym_count != 0)
4425 || (finfo.indices == NULL && max_sym_count != 0)
4426 || (finfo.sections == NULL && max_sym_count != 0))
4427 goto error_return;
4429 /* Since ELF permits relocations to be against local symbols, we
4430 must have the local symbols available when we do the relocations.
4431 Since we would rather only read the local symbols once, and we
4432 would rather not keep them in memory, we handle all the
4433 relocations for a single input file at the same time.
4435 Unfortunately, there is no way to know the total number of local
4436 symbols until we have seen all of them, and the local symbol
4437 indices precede the global symbol indices. This means that when
4438 we are generating relocateable output, and we see a reloc against
4439 a global symbol, we can not know the symbol index until we have
4440 finished examining all the local symbols to see which ones we are
4441 going to output. To deal with this, we keep the relocations in
4442 memory, and don't output them until the end of the link. This is
4443 an unfortunate waste of memory, but I don't see a good way around
4444 it. Fortunately, it only happens when performing a relocateable
4445 link, which is not the common case. FIXME: If keep_memory is set
4446 we could write the relocs out and then read them again; I don't
4447 know how bad the memory loss will be. */
4449 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4450 sub->output_has_begun = false;
4451 for (o = abfd->sections; o != NULL; o = o->next)
4453 for (p = o->link_order_head; p != NULL; p = p->next)
4455 if (p->type == bfd_indirect_link_order
4456 && (bfd_get_flavour (p->u.indirect.section->owner)
4457 == bfd_target_elf_flavour))
4459 sub = p->u.indirect.section->owner;
4460 if (! sub->output_has_begun)
4462 if (! elf_link_input_bfd (&finfo, sub))
4463 goto error_return;
4464 sub->output_has_begun = true;
4467 else if (p->type == bfd_section_reloc_link_order
4468 || p->type == bfd_symbol_reloc_link_order)
4470 if (! elf_reloc_link_order (abfd, info, o, p))
4471 goto error_return;
4473 else
4475 if (! _bfd_default_link_order (abfd, info, o, p))
4476 goto error_return;
4481 /* That wrote out all the local symbols. Finish up the symbol table
4482 with the global symbols. Even if we want to strip everything we
4483 can, we still need to deal with those global symbols that got
4484 converted to local in a version script. */
4486 if (info->shared)
4488 /* Output any global symbols that got converted to local in a
4489 version script. We do this in a separate step since ELF
4490 requires all local symbols to appear prior to any global
4491 symbols. FIXME: We should only do this if some global
4492 symbols were, in fact, converted to become local. FIXME:
4493 Will this work correctly with the Irix 5 linker? */
4494 eoinfo.failed = false;
4495 eoinfo.finfo = &finfo;
4496 eoinfo.localsyms = true;
4497 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4498 (PTR) &eoinfo);
4499 if (eoinfo.failed)
4500 return false;
4503 /* The sh_info field records the index of the first non local symbol. */
4504 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4506 if (dynamic)
4508 Elf_Internal_Sym sym;
4509 Elf_External_Sym *dynsym =
4510 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4511 long last_local = 0;
4513 /* Write out the section symbols for the output sections. */
4514 if (info->shared)
4516 asection *s;
4518 sym.st_size = 0;
4519 sym.st_name = 0;
4520 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4521 sym.st_other = 0;
4523 for (s = abfd->sections; s != NULL; s = s->next)
4525 int indx;
4526 indx = elf_section_data (s)->this_idx;
4527 BFD_ASSERT (indx > 0);
4528 sym.st_shndx = indx;
4529 sym.st_value = s->vma;
4531 elf_swap_symbol_out (abfd, &sym,
4532 dynsym + elf_section_data (s)->dynindx);
4535 last_local = bfd_count_sections (abfd);
4538 /* Write out the local dynsyms. */
4539 if (elf_hash_table (info)->dynlocal)
4541 struct elf_link_local_dynamic_entry *e;
4542 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4544 asection *s;
4546 sym.st_size = e->isym.st_size;
4547 sym.st_other = e->isym.st_other;
4549 /* Copy the internal symbol as is.
4550 Note that we saved a word of storage and overwrote
4551 the original st_name with the dynstr_index. */
4552 sym = e->isym;
4554 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4556 s = bfd_section_from_elf_index (e->input_bfd,
4557 e->isym.st_shndx);
4559 sym.st_shndx =
4560 elf_section_data (s->output_section)->this_idx;
4561 sym.st_value = (s->output_section->vma
4562 + s->output_offset
4563 + e->isym.st_value);
4566 if (last_local < e->dynindx)
4567 last_local = e->dynindx;
4569 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4573 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4574 last_local + 1;
4577 /* We get the global symbols from the hash table. */
4578 eoinfo.failed = false;
4579 eoinfo.localsyms = false;
4580 eoinfo.finfo = &finfo;
4581 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4582 (PTR) &eoinfo);
4583 if (eoinfo.failed)
4584 return false;
4586 /* If backend needs to output some symbols not present in the hash
4587 table, do it now. */
4588 if (bed->elf_backend_output_arch_syms)
4590 if (! (*bed->elf_backend_output_arch_syms)
4591 (abfd, info, (PTR) &finfo,
4592 (boolean (*) PARAMS ((PTR, const char *,
4593 Elf_Internal_Sym *, asection *)))
4594 elf_link_output_sym))
4595 return false;
4598 /* Flush all symbols to the file. */
4599 if (! elf_link_flush_output_syms (&finfo))
4600 return false;
4602 /* Now we know the size of the symtab section. */
4603 off += symtab_hdr->sh_size;
4605 /* Finish up and write out the symbol string table (.strtab)
4606 section. */
4607 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4608 /* sh_name was set in prep_headers. */
4609 symstrtab_hdr->sh_type = SHT_STRTAB;
4610 symstrtab_hdr->sh_flags = 0;
4611 symstrtab_hdr->sh_addr = 0;
4612 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4613 symstrtab_hdr->sh_entsize = 0;
4614 symstrtab_hdr->sh_link = 0;
4615 symstrtab_hdr->sh_info = 0;
4616 /* sh_offset is set just below. */
4617 symstrtab_hdr->sh_addralign = 1;
4619 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4620 elf_tdata (abfd)->next_file_pos = off;
4622 if (bfd_get_symcount (abfd) > 0)
4624 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4625 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4626 return false;
4629 /* Adjust the relocs to have the correct symbol indices. */
4630 for (o = abfd->sections; o != NULL; o = o->next)
4632 if ((o->flags & SEC_RELOC) == 0)
4633 continue;
4635 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4636 elf_section_data (o)->rel_count,
4637 elf_section_data (o)->rel_hashes);
4638 if (elf_section_data (o)->rel_hdr2 != NULL)
4639 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4640 elf_section_data (o)->rel_count2,
4641 (elf_section_data (o)->rel_hashes
4642 + elf_section_data (o)->rel_count));
4644 /* Set the reloc_count field to 0 to prevent write_relocs from
4645 trying to swap the relocs out itself. */
4646 o->reloc_count = 0;
4649 /* If we are linking against a dynamic object, or generating a
4650 shared library, finish up the dynamic linking information. */
4651 if (dynamic)
4653 Elf_External_Dyn *dyncon, *dynconend;
4655 /* Fix up .dynamic entries. */
4656 o = bfd_get_section_by_name (dynobj, ".dynamic");
4657 BFD_ASSERT (o != NULL);
4659 dyncon = (Elf_External_Dyn *) o->contents;
4660 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4661 for (; dyncon < dynconend; dyncon++)
4663 Elf_Internal_Dyn dyn;
4664 const char *name;
4665 unsigned int type;
4667 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4669 switch (dyn.d_tag)
4671 default:
4672 break;
4673 case DT_INIT:
4674 name = info->init_function;
4675 goto get_sym;
4676 case DT_FINI:
4677 name = info->fini_function;
4678 get_sym:
4680 struct elf_link_hash_entry *h;
4682 h = elf_link_hash_lookup (elf_hash_table (info), name,
4683 false, false, true);
4684 if (h != NULL
4685 && (h->root.type == bfd_link_hash_defined
4686 || h->root.type == bfd_link_hash_defweak))
4688 dyn.d_un.d_val = h->root.u.def.value;
4689 o = h->root.u.def.section;
4690 if (o->output_section != NULL)
4691 dyn.d_un.d_val += (o->output_section->vma
4692 + o->output_offset);
4693 else
4695 /* The symbol is imported from another shared
4696 library and does not apply to this one. */
4697 dyn.d_un.d_val = 0;
4700 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4703 break;
4705 case DT_HASH:
4706 name = ".hash";
4707 goto get_vma;
4708 case DT_STRTAB:
4709 name = ".dynstr";
4710 goto get_vma;
4711 case DT_SYMTAB:
4712 name = ".dynsym";
4713 goto get_vma;
4714 case DT_VERDEF:
4715 name = ".gnu.version_d";
4716 goto get_vma;
4717 case DT_VERNEED:
4718 name = ".gnu.version_r";
4719 goto get_vma;
4720 case DT_VERSYM:
4721 name = ".gnu.version";
4722 get_vma:
4723 o = bfd_get_section_by_name (abfd, name);
4724 BFD_ASSERT (o != NULL);
4725 dyn.d_un.d_ptr = o->vma;
4726 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4727 break;
4729 case DT_REL:
4730 case DT_RELA:
4731 case DT_RELSZ:
4732 case DT_RELASZ:
4733 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4734 type = SHT_REL;
4735 else
4736 type = SHT_RELA;
4737 dyn.d_un.d_val = 0;
4738 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4740 Elf_Internal_Shdr *hdr;
4742 hdr = elf_elfsections (abfd)[i];
4743 if (hdr->sh_type == type
4744 && (hdr->sh_flags & SHF_ALLOC) != 0)
4746 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4747 dyn.d_un.d_val += hdr->sh_size;
4748 else
4750 if (dyn.d_un.d_val == 0
4751 || hdr->sh_addr < dyn.d_un.d_val)
4752 dyn.d_un.d_val = hdr->sh_addr;
4756 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4757 break;
4762 /* If we have created any dynamic sections, then output them. */
4763 if (dynobj != NULL)
4765 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4766 goto error_return;
4768 for (o = dynobj->sections; o != NULL; o = o->next)
4770 if ((o->flags & SEC_HAS_CONTENTS) == 0
4771 || o->_raw_size == 0)
4772 continue;
4773 if ((o->flags & SEC_LINKER_CREATED) == 0)
4775 /* At this point, we are only interested in sections
4776 created by elf_link_create_dynamic_sections. */
4777 continue;
4779 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4780 != SHT_STRTAB)
4781 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4783 if (! bfd_set_section_contents (abfd, o->output_section,
4784 o->contents, o->output_offset,
4785 o->_raw_size))
4786 goto error_return;
4788 else
4790 file_ptr off;
4792 /* The contents of the .dynstr section are actually in a
4793 stringtab. */
4794 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4795 if (bfd_seek (abfd, off, SEEK_SET) != 0
4796 || ! _bfd_stringtab_emit (abfd,
4797 elf_hash_table (info)->dynstr))
4798 goto error_return;
4803 /* If we have optimized stabs strings, output them. */
4804 if (elf_hash_table (info)->stab_info != NULL)
4806 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4807 goto error_return;
4810 if (finfo.symstrtab != NULL)
4811 _bfd_stringtab_free (finfo.symstrtab);
4812 if (finfo.contents != NULL)
4813 free (finfo.contents);
4814 if (finfo.external_relocs != NULL)
4815 free (finfo.external_relocs);
4816 if (finfo.internal_relocs != NULL)
4817 free (finfo.internal_relocs);
4818 if (finfo.external_syms != NULL)
4819 free (finfo.external_syms);
4820 if (finfo.internal_syms != NULL)
4821 free (finfo.internal_syms);
4822 if (finfo.indices != NULL)
4823 free (finfo.indices);
4824 if (finfo.sections != NULL)
4825 free (finfo.sections);
4826 if (finfo.symbuf != NULL)
4827 free (finfo.symbuf);
4828 for (o = abfd->sections; o != NULL; o = o->next)
4830 if ((o->flags & SEC_RELOC) != 0
4831 && elf_section_data (o)->rel_hashes != NULL)
4832 free (elf_section_data (o)->rel_hashes);
4835 elf_tdata (abfd)->linker = true;
4837 return true;
4839 error_return:
4840 if (finfo.symstrtab != NULL)
4841 _bfd_stringtab_free (finfo.symstrtab);
4842 if (finfo.contents != NULL)
4843 free (finfo.contents);
4844 if (finfo.external_relocs != NULL)
4845 free (finfo.external_relocs);
4846 if (finfo.internal_relocs != NULL)
4847 free (finfo.internal_relocs);
4848 if (finfo.external_syms != NULL)
4849 free (finfo.external_syms);
4850 if (finfo.internal_syms != NULL)
4851 free (finfo.internal_syms);
4852 if (finfo.indices != NULL)
4853 free (finfo.indices);
4854 if (finfo.sections != NULL)
4855 free (finfo.sections);
4856 if (finfo.symbuf != NULL)
4857 free (finfo.symbuf);
4858 for (o = abfd->sections; o != NULL; o = o->next)
4860 if ((o->flags & SEC_RELOC) != 0
4861 && elf_section_data (o)->rel_hashes != NULL)
4862 free (elf_section_data (o)->rel_hashes);
4865 return false;
4868 /* Add a symbol to the output symbol table. */
4870 static boolean
4871 elf_link_output_sym (finfo, name, elfsym, input_sec)
4872 struct elf_final_link_info *finfo;
4873 const char *name;
4874 Elf_Internal_Sym *elfsym;
4875 asection *input_sec;
4877 boolean (*output_symbol_hook) PARAMS ((bfd *,
4878 struct bfd_link_info *info,
4879 const char *,
4880 Elf_Internal_Sym *,
4881 asection *));
4883 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4884 elf_backend_link_output_symbol_hook;
4885 if (output_symbol_hook != NULL)
4887 if (! ((*output_symbol_hook)
4888 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4889 return false;
4892 if (name == (const char *) NULL || *name == '\0')
4893 elfsym->st_name = 0;
4894 else if (input_sec->flags & SEC_EXCLUDE)
4895 elfsym->st_name = 0;
4896 else
4898 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4899 name, true,
4900 false);
4901 if (elfsym->st_name == (unsigned long) -1)
4902 return false;
4905 if (finfo->symbuf_count >= finfo->symbuf_size)
4907 if (! elf_link_flush_output_syms (finfo))
4908 return false;
4911 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4912 (PTR) (finfo->symbuf + finfo->symbuf_count));
4913 ++finfo->symbuf_count;
4915 ++ bfd_get_symcount (finfo->output_bfd);
4917 return true;
4920 /* Flush the output symbols to the file. */
4922 static boolean
4923 elf_link_flush_output_syms (finfo)
4924 struct elf_final_link_info *finfo;
4926 if (finfo->symbuf_count > 0)
4928 Elf_Internal_Shdr *symtab;
4930 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4932 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4933 SEEK_SET) != 0
4934 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4935 sizeof (Elf_External_Sym), finfo->output_bfd)
4936 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4937 return false;
4939 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4941 finfo->symbuf_count = 0;
4944 return true;
4947 /* Add an external symbol to the symbol table. This is called from
4948 the hash table traversal routine. When generating a shared object,
4949 we go through the symbol table twice. The first time we output
4950 anything that might have been forced to local scope in a version
4951 script. The second time we output the symbols that are still
4952 global symbols. */
4954 static boolean
4955 elf_link_output_extsym (h, data)
4956 struct elf_link_hash_entry *h;
4957 PTR data;
4959 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4960 struct elf_final_link_info *finfo = eoinfo->finfo;
4961 boolean strip;
4962 Elf_Internal_Sym sym;
4963 asection *input_sec;
4965 /* Decide whether to output this symbol in this pass. */
4966 if (eoinfo->localsyms)
4968 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4969 return true;
4971 else
4973 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4974 return true;
4977 /* If we are not creating a shared library, and this symbol is
4978 referenced by a shared library but is not defined anywhere, then
4979 warn that it is undefined. If we do not do this, the runtime
4980 linker will complain that the symbol is undefined when the
4981 program is run. We don't have to worry about symbols that are
4982 referenced by regular files, because we will already have issued
4983 warnings for them. */
4984 if (! finfo->info->relocateable
4985 && ! (finfo->info->shared
4986 && !finfo->info->no_undefined)
4987 && h->root.type == bfd_link_hash_undefined
4988 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
4989 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4991 if (! ((*finfo->info->callbacks->undefined_symbol)
4992 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
4993 (asection *) NULL, 0, true)))
4995 eoinfo->failed = true;
4996 return false;
5000 /* We don't want to output symbols that have never been mentioned by
5001 a regular file, or that we have been told to strip. However, if
5002 h->indx is set to -2, the symbol is used by a reloc and we must
5003 output it. */
5004 if (h->indx == -2)
5005 strip = false;
5006 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
5007 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
5008 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
5009 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5010 strip = true;
5011 else if (finfo->info->strip == strip_all
5012 || (finfo->info->strip == strip_some
5013 && bfd_hash_lookup (finfo->info->keep_hash,
5014 h->root.root.string,
5015 false, false) == NULL))
5016 strip = true;
5017 else
5018 strip = false;
5020 /* If we're stripping it, and it's not a dynamic symbol, there's
5021 nothing else to do unless it is a forced local symbol. */
5022 if (strip
5023 && h->dynindx == -1
5024 && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5025 return true;
5027 sym.st_value = 0;
5028 sym.st_size = h->size;
5029 sym.st_other = h->other;
5030 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5031 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
5032 else if (h->root.type == bfd_link_hash_undefweak
5033 || h->root.type == bfd_link_hash_defweak)
5034 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
5035 else
5036 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
5038 switch (h->root.type)
5040 default:
5041 case bfd_link_hash_new:
5042 abort ();
5043 return false;
5045 case bfd_link_hash_undefined:
5046 input_sec = bfd_und_section_ptr;
5047 sym.st_shndx = SHN_UNDEF;
5048 break;
5050 case bfd_link_hash_undefweak:
5051 input_sec = bfd_und_section_ptr;
5052 sym.st_shndx = SHN_UNDEF;
5053 break;
5055 case bfd_link_hash_defined:
5056 case bfd_link_hash_defweak:
5058 input_sec = h->root.u.def.section;
5059 if (input_sec->output_section != NULL)
5061 sym.st_shndx =
5062 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
5063 input_sec->output_section);
5064 if (sym.st_shndx == (unsigned short) -1)
5066 (*_bfd_error_handler)
5067 (_("%s: could not find output section %s for input section %s"),
5068 bfd_get_filename (finfo->output_bfd),
5069 input_sec->output_section->name,
5070 input_sec->name);
5071 eoinfo->failed = true;
5072 return false;
5075 /* ELF symbols in relocateable files are section relative,
5076 but in nonrelocateable files they are virtual
5077 addresses. */
5078 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5079 if (! finfo->info->relocateable)
5080 sym.st_value += input_sec->output_section->vma;
5082 else
5084 BFD_ASSERT (input_sec->owner == NULL
5085 || (input_sec->owner->flags & DYNAMIC) != 0);
5086 sym.st_shndx = SHN_UNDEF;
5087 input_sec = bfd_und_section_ptr;
5090 break;
5092 case bfd_link_hash_common:
5093 input_sec = h->root.u.c.p->section;
5094 sym.st_shndx = SHN_COMMON;
5095 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5096 break;
5098 case bfd_link_hash_indirect:
5099 /* These symbols are created by symbol versioning. They point
5100 to the decorated version of the name. For example, if the
5101 symbol foo@@GNU_1.2 is the default, which should be used when
5102 foo is used with no version, then we add an indirect symbol
5103 foo which points to foo@@GNU_1.2. We ignore these symbols,
5104 since the indirected symbol is already in the hash table. */
5105 return true;
5107 case bfd_link_hash_warning:
5108 /* We can't represent these symbols in ELF, although a warning
5109 symbol may have come from a .gnu.warning.SYMBOL section. We
5110 just put the target symbol in the hash table. If the target
5111 symbol does not really exist, don't do anything. */
5112 if (h->root.u.i.link->type == bfd_link_hash_new)
5113 return true;
5114 return (elf_link_output_extsym
5115 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5118 /* Give the processor backend a chance to tweak the symbol value,
5119 and also to finish up anything that needs to be done for this
5120 symbol. */
5121 if ((h->dynindx != -1
5122 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5123 && elf_hash_table (finfo->info)->dynamic_sections_created)
5125 struct elf_backend_data *bed;
5127 bed = get_elf_backend_data (finfo->output_bfd);
5128 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5129 (finfo->output_bfd, finfo->info, h, &sym)))
5131 eoinfo->failed = true;
5132 return false;
5136 /* If we are marking the symbol as undefined, and there are no
5137 non-weak references to this symbol from a regular object, then
5138 mark the symbol as weak undefined; if there are non-weak
5139 references, mark the symbol as strong. We can't do this earlier,
5140 because it might not be marked as undefined until the
5141 finish_dynamic_symbol routine gets through with it. */
5142 if (sym.st_shndx == SHN_UNDEF
5143 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5144 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5145 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5147 int bindtype;
5149 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5150 bindtype = STB_GLOBAL;
5151 else
5152 bindtype = STB_WEAK;
5153 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5156 /* If a symbol is not defined locally, we clear the visibility
5157 field. */
5158 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5159 sym.st_other ^= ELF_ST_VISIBILITY(sym.st_other);
5161 /* If this symbol should be put in the .dynsym section, then put it
5162 there now. We have already know the symbol index. We also fill
5163 in the entry in the .hash section. */
5164 if (h->dynindx != -1
5165 && elf_hash_table (finfo->info)->dynamic_sections_created)
5167 size_t bucketcount;
5168 size_t bucket;
5169 size_t hash_entry_size;
5170 bfd_byte *bucketpos;
5171 bfd_vma chain;
5173 sym.st_name = h->dynstr_index;
5175 elf_swap_symbol_out (finfo->output_bfd, &sym,
5176 (PTR) (((Elf_External_Sym *)
5177 finfo->dynsym_sec->contents)
5178 + h->dynindx));
5180 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5181 bucket = h->elf_hash_value % bucketcount;
5182 hash_entry_size
5183 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5184 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5185 + (bucket + 2) * hash_entry_size);
5186 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5187 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5188 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5189 ((bfd_byte *) finfo->hash_sec->contents
5190 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5192 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5194 Elf_Internal_Versym iversym;
5196 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5198 if (h->verinfo.verdef == NULL)
5199 iversym.vs_vers = 0;
5200 else
5201 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5203 else
5205 if (h->verinfo.vertree == NULL)
5206 iversym.vs_vers = 1;
5207 else
5208 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5211 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5212 iversym.vs_vers |= VERSYM_HIDDEN;
5214 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5215 (((Elf_External_Versym *)
5216 finfo->symver_sec->contents)
5217 + h->dynindx));
5221 /* If we're stripping it, then it was just a dynamic symbol, and
5222 there's nothing else to do. */
5223 if (strip)
5224 return true;
5226 h->indx = bfd_get_symcount (finfo->output_bfd);
5228 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5230 eoinfo->failed = true;
5231 return false;
5234 return true;
5237 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5238 originated from the section given by INPUT_REL_HDR) to the
5239 OUTPUT_BFD. */
5241 static void
5242 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5243 internal_relocs)
5244 bfd *output_bfd;
5245 asection *input_section;
5246 Elf_Internal_Shdr *input_rel_hdr;
5247 Elf_Internal_Rela *internal_relocs;
5249 Elf_Internal_Rela *irela;
5250 Elf_Internal_Rela *irelaend;
5251 Elf_Internal_Shdr *output_rel_hdr;
5252 asection *output_section;
5253 unsigned int *rel_countp = NULL;
5254 struct elf_backend_data *bed;
5256 output_section = input_section->output_section;
5257 output_rel_hdr = NULL;
5259 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5260 == input_rel_hdr->sh_entsize)
5262 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5263 rel_countp = &elf_section_data (output_section)->rel_count;
5265 else if (elf_section_data (output_section)->rel_hdr2
5266 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5267 == input_rel_hdr->sh_entsize))
5269 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5270 rel_countp = &elf_section_data (output_section)->rel_count2;
5273 BFD_ASSERT (output_rel_hdr != NULL);
5275 bed = get_elf_backend_data (output_bfd);
5276 irela = internal_relocs;
5277 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5278 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5280 Elf_External_Rel *erel;
5282 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5283 for (; irela < irelaend; irela++, erel++)
5285 Elf_Internal_Rel irel;
5287 irel.r_offset = irela->r_offset;
5288 irel.r_info = irela->r_info;
5289 BFD_ASSERT (irela->r_addend == 0);
5290 if (bed->s->swap_reloc_out)
5291 (*bed->s->swap_reloc_out) (output_bfd, &irel, (PTR) erel);
5292 else
5293 elf_swap_reloc_out (output_bfd, &irel, erel);
5296 else
5298 Elf_External_Rela *erela;
5300 BFD_ASSERT (input_rel_hdr->sh_entsize
5301 == sizeof (Elf_External_Rela));
5302 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5303 for (; irela < irelaend; irela++, erela++)
5304 if (bed->s->swap_reloca_out)
5305 (*bed->s->swap_reloca_out) (output_bfd, irela, (PTR) erela);
5306 else
5307 elf_swap_reloca_out (output_bfd, irela, erela);
5310 /* Bump the counter, so that we know where to add the next set of
5311 relocations. */
5312 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5315 /* Link an input file into the linker output file. This function
5316 handles all the sections and relocations of the input file at once.
5317 This is so that we only have to read the local symbols once, and
5318 don't have to keep them in memory. */
5320 static boolean
5321 elf_link_input_bfd (finfo, input_bfd)
5322 struct elf_final_link_info *finfo;
5323 bfd *input_bfd;
5325 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5326 bfd *, asection *, bfd_byte *,
5327 Elf_Internal_Rela *,
5328 Elf_Internal_Sym *, asection **));
5329 bfd *output_bfd;
5330 Elf_Internal_Shdr *symtab_hdr;
5331 size_t locsymcount;
5332 size_t extsymoff;
5333 Elf_External_Sym *external_syms;
5334 Elf_External_Sym *esym;
5335 Elf_External_Sym *esymend;
5336 Elf_Internal_Sym *isym;
5337 long *pindex;
5338 asection **ppsection;
5339 asection *o;
5340 struct elf_backend_data *bed;
5342 output_bfd = finfo->output_bfd;
5343 bed = get_elf_backend_data (output_bfd);
5344 relocate_section = bed->elf_backend_relocate_section;
5346 /* If this is a dynamic object, we don't want to do anything here:
5347 we don't want the local symbols, and we don't want the section
5348 contents. */
5349 if ((input_bfd->flags & DYNAMIC) != 0)
5350 return true;
5352 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5353 if (elf_bad_symtab (input_bfd))
5355 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5356 extsymoff = 0;
5358 else
5360 locsymcount = symtab_hdr->sh_info;
5361 extsymoff = symtab_hdr->sh_info;
5364 /* Read the local symbols. */
5365 if (symtab_hdr->contents != NULL)
5366 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5367 else if (locsymcount == 0)
5368 external_syms = NULL;
5369 else
5371 external_syms = finfo->external_syms;
5372 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5373 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5374 locsymcount, input_bfd)
5375 != locsymcount * sizeof (Elf_External_Sym)))
5376 return false;
5379 /* Swap in the local symbols and write out the ones which we know
5380 are going into the output file. */
5381 esym = external_syms;
5382 esymend = esym + locsymcount;
5383 isym = finfo->internal_syms;
5384 pindex = finfo->indices;
5385 ppsection = finfo->sections;
5386 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5388 asection *isec;
5389 const char *name;
5390 Elf_Internal_Sym osym;
5392 elf_swap_symbol_in (input_bfd, esym, isym);
5393 *pindex = -1;
5395 if (elf_bad_symtab (input_bfd))
5397 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5399 *ppsection = NULL;
5400 continue;
5404 if (isym->st_shndx == SHN_UNDEF)
5405 isec = bfd_und_section_ptr;
5406 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5407 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5408 else if (isym->st_shndx == SHN_ABS)
5409 isec = bfd_abs_section_ptr;
5410 else if (isym->st_shndx == SHN_COMMON)
5411 isec = bfd_com_section_ptr;
5412 else
5414 /* Who knows? */
5415 isec = NULL;
5418 *ppsection = isec;
5420 /* Don't output the first, undefined, symbol. */
5421 if (esym == external_syms)
5422 continue;
5424 /* If we are stripping all symbols, we don't want to output this
5425 one. */
5426 if (finfo->info->strip == strip_all)
5427 continue;
5429 /* We never output section symbols. Instead, we use the section
5430 symbol of the corresponding section in the output file. */
5431 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5432 continue;
5434 /* If we are discarding all local symbols, we don't want to
5435 output this one. If we are generating a relocateable output
5436 file, then some of the local symbols may be required by
5437 relocs; we output them below as we discover that they are
5438 needed. */
5439 if (finfo->info->discard == discard_all)
5440 continue;
5442 /* If this symbol is defined in a section which we are
5443 discarding, we don't need to keep it, but note that
5444 linker_mark is only reliable for sections that have contents.
5445 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5446 as well as linker_mark. */
5447 if (isym->st_shndx > 0
5448 && isym->st_shndx < SHN_LORESERVE
5449 && isec != NULL
5450 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5451 || (! finfo->info->relocateable
5452 && (isec->flags & SEC_EXCLUDE) != 0)))
5453 continue;
5455 /* Get the name of the symbol. */
5456 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5457 isym->st_name);
5458 if (name == NULL)
5459 return false;
5461 /* See if we are discarding symbols with this name. */
5462 if ((finfo->info->strip == strip_some
5463 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5464 == NULL))
5465 || (finfo->info->discard == discard_l
5466 && bfd_is_local_label_name (input_bfd, name)))
5467 continue;
5469 /* If we get here, we are going to output this symbol. */
5471 osym = *isym;
5473 /* Adjust the section index for the output file. */
5474 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5475 isec->output_section);
5476 if (osym.st_shndx == (unsigned short) -1)
5477 return false;
5479 *pindex = bfd_get_symcount (output_bfd);
5481 /* ELF symbols in relocateable files are section relative, but
5482 in executable files they are virtual addresses. Note that
5483 this code assumes that all ELF sections have an associated
5484 BFD section with a reasonable value for output_offset; below
5485 we assume that they also have a reasonable value for
5486 output_section. Any special sections must be set up to meet
5487 these requirements. */
5488 osym.st_value += isec->output_offset;
5489 if (! finfo->info->relocateable)
5490 osym.st_value += isec->output_section->vma;
5492 if (! elf_link_output_sym (finfo, name, &osym, isec))
5493 return false;
5496 /* Relocate the contents of each section. */
5497 for (o = input_bfd->sections; o != NULL; o = o->next)
5499 bfd_byte *contents;
5501 if (! o->linker_mark)
5503 /* This section was omitted from the link. */
5504 continue;
5507 if ((o->flags & SEC_HAS_CONTENTS) == 0
5508 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5509 continue;
5511 if ((o->flags & SEC_LINKER_CREATED) != 0)
5513 /* Section was created by elf_link_create_dynamic_sections
5514 or somesuch. */
5515 continue;
5518 /* Get the contents of the section. They have been cached by a
5519 relaxation routine. Note that o is a section in an input
5520 file, so the contents field will not have been set by any of
5521 the routines which work on output files. */
5522 if (elf_section_data (o)->this_hdr.contents != NULL)
5523 contents = elf_section_data (o)->this_hdr.contents;
5524 else
5526 contents = finfo->contents;
5527 if (! bfd_get_section_contents (input_bfd, o, contents,
5528 (file_ptr) 0, o->_raw_size))
5529 return false;
5532 if ((o->flags & SEC_RELOC) != 0)
5534 Elf_Internal_Rela *internal_relocs;
5536 /* Get the swapped relocs. */
5537 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5538 (input_bfd, o, finfo->external_relocs,
5539 finfo->internal_relocs, false));
5540 if (internal_relocs == NULL
5541 && o->reloc_count > 0)
5542 return false;
5544 /* Relocate the section by invoking a back end routine.
5546 The back end routine is responsible for adjusting the
5547 section contents as necessary, and (if using Rela relocs
5548 and generating a relocateable output file) adjusting the
5549 reloc addend as necessary.
5551 The back end routine does not have to worry about setting
5552 the reloc address or the reloc symbol index.
5554 The back end routine is given a pointer to the swapped in
5555 internal symbols, and can access the hash table entries
5556 for the external symbols via elf_sym_hashes (input_bfd).
5558 When generating relocateable output, the back end routine
5559 must handle STB_LOCAL/STT_SECTION symbols specially. The
5560 output symbol is going to be a section symbol
5561 corresponding to the output section, which will require
5562 the addend to be adjusted. */
5564 if (! (*relocate_section) (output_bfd, finfo->info,
5565 input_bfd, o, contents,
5566 internal_relocs,
5567 finfo->internal_syms,
5568 finfo->sections))
5569 return false;
5571 if (finfo->info->relocateable || finfo->info->emitrelocations)
5573 Elf_Internal_Rela *irela;
5574 Elf_Internal_Rela *irelaend;
5575 struct elf_link_hash_entry **rel_hash;
5576 Elf_Internal_Shdr *input_rel_hdr;
5578 /* Adjust the reloc addresses and symbol indices. */
5580 irela = internal_relocs;
5581 irelaend =
5582 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5583 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5584 + elf_section_data (o->output_section)->rel_count
5585 + elf_section_data (o->output_section)->rel_count2);
5586 for (; irela < irelaend; irela++, rel_hash++)
5588 unsigned long r_symndx;
5589 Elf_Internal_Sym *isym;
5590 asection *sec;
5592 irela->r_offset += o->output_offset;
5594 /* Relocs in an executable have to be virtual addresses. */
5595 if (finfo->info->emitrelocations)
5596 irela->r_offset += o->output_section->vma;
5598 r_symndx = ELF_R_SYM (irela->r_info);
5600 if (r_symndx == 0)
5601 continue;
5603 if (r_symndx >= locsymcount
5604 || (elf_bad_symtab (input_bfd)
5605 && finfo->sections[r_symndx] == NULL))
5607 struct elf_link_hash_entry *rh;
5608 long indx;
5610 /* This is a reloc against a global symbol. We
5611 have not yet output all the local symbols, so
5612 we do not know the symbol index of any global
5613 symbol. We set the rel_hash entry for this
5614 reloc to point to the global hash table entry
5615 for this symbol. The symbol index is then
5616 set at the end of elf_bfd_final_link. */
5617 indx = r_symndx - extsymoff;
5618 rh = elf_sym_hashes (input_bfd)[indx];
5619 while (rh->root.type == bfd_link_hash_indirect
5620 || rh->root.type == bfd_link_hash_warning)
5621 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5623 /* Setting the index to -2 tells
5624 elf_link_output_extsym that this symbol is
5625 used by a reloc. */
5626 BFD_ASSERT (rh->indx < 0);
5627 rh->indx = -2;
5629 *rel_hash = rh;
5631 continue;
5634 /* This is a reloc against a local symbol. */
5636 *rel_hash = NULL;
5637 isym = finfo->internal_syms + r_symndx;
5638 sec = finfo->sections[r_symndx];
5639 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5641 /* I suppose the backend ought to fill in the
5642 section of any STT_SECTION symbol against a
5643 processor specific section. If we have
5644 discarded a section, the output_section will
5645 be the absolute section. */
5646 if (sec != NULL
5647 && (bfd_is_abs_section (sec)
5648 || (sec->output_section != NULL
5649 && bfd_is_abs_section (sec->output_section))))
5650 r_symndx = 0;
5651 else if (sec == NULL || sec->owner == NULL)
5653 bfd_set_error (bfd_error_bad_value);
5654 return false;
5656 else
5658 r_symndx = sec->output_section->target_index;
5659 BFD_ASSERT (r_symndx != 0);
5662 else
5664 if (finfo->indices[r_symndx] == -1)
5666 unsigned long link;
5667 const char *name;
5668 asection *osec;
5670 if (finfo->info->strip == strip_all)
5672 /* You can't do ld -r -s. */
5673 bfd_set_error (bfd_error_invalid_operation);
5674 return false;
5677 /* This symbol was skipped earlier, but
5678 since it is needed by a reloc, we
5679 must output it now. */
5680 link = symtab_hdr->sh_link;
5681 name = bfd_elf_string_from_elf_section (input_bfd,
5682 link,
5683 isym->st_name);
5684 if (name == NULL)
5685 return false;
5687 osec = sec->output_section;
5688 isym->st_shndx =
5689 _bfd_elf_section_from_bfd_section (output_bfd,
5690 osec);
5691 if (isym->st_shndx == (unsigned short) -1)
5692 return false;
5694 isym->st_value += sec->output_offset;
5695 if (! finfo->info->relocateable)
5696 isym->st_value += osec->vma;
5698 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5700 if (! elf_link_output_sym (finfo, name, isym, sec))
5701 return false;
5704 r_symndx = finfo->indices[r_symndx];
5707 irela->r_info = ELF_R_INFO (r_symndx,
5708 ELF_R_TYPE (irela->r_info));
5711 /* Swap out the relocs. */
5712 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5713 elf_link_output_relocs (output_bfd, o,
5714 input_rel_hdr,
5715 internal_relocs);
5716 internal_relocs
5717 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5718 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5719 if (input_rel_hdr)
5720 elf_link_output_relocs (output_bfd, o,
5721 input_rel_hdr,
5722 internal_relocs);
5726 /* Write out the modified section contents. */
5727 if (elf_section_data (o)->stab_info == NULL)
5729 if (! (o->flags & SEC_EXCLUDE) &&
5730 ! bfd_set_section_contents (output_bfd, o->output_section,
5731 contents, o->output_offset,
5732 (o->_cooked_size != 0
5733 ? o->_cooked_size
5734 : o->_raw_size)))
5735 return false;
5737 else
5739 if (! (_bfd_write_section_stabs
5740 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5741 o, &elf_section_data (o)->stab_info, contents)))
5742 return false;
5746 return true;
5749 /* Generate a reloc when linking an ELF file. This is a reloc
5750 requested by the linker, and does come from any input file. This
5751 is used to build constructor and destructor tables when linking
5752 with -Ur. */
5754 static boolean
5755 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5756 bfd *output_bfd;
5757 struct bfd_link_info *info;
5758 asection *output_section;
5759 struct bfd_link_order *link_order;
5761 reloc_howto_type *howto;
5762 long indx;
5763 bfd_vma offset;
5764 bfd_vma addend;
5765 struct elf_link_hash_entry **rel_hash_ptr;
5766 Elf_Internal_Shdr *rel_hdr;
5767 struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
5769 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5770 if (howto == NULL)
5772 bfd_set_error (bfd_error_bad_value);
5773 return false;
5776 addend = link_order->u.reloc.p->addend;
5778 /* Figure out the symbol index. */
5779 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5780 + elf_section_data (output_section)->rel_count
5781 + elf_section_data (output_section)->rel_count2);
5782 if (link_order->type == bfd_section_reloc_link_order)
5784 indx = link_order->u.reloc.p->u.section->target_index;
5785 BFD_ASSERT (indx != 0);
5786 *rel_hash_ptr = NULL;
5788 else
5790 struct elf_link_hash_entry *h;
5792 /* Treat a reloc against a defined symbol as though it were
5793 actually against the section. */
5794 h = ((struct elf_link_hash_entry *)
5795 bfd_wrapped_link_hash_lookup (output_bfd, info,
5796 link_order->u.reloc.p->u.name,
5797 false, false, true));
5798 if (h != NULL
5799 && (h->root.type == bfd_link_hash_defined
5800 || h->root.type == bfd_link_hash_defweak))
5802 asection *section;
5804 section = h->root.u.def.section;
5805 indx = section->output_section->target_index;
5806 *rel_hash_ptr = NULL;
5807 /* It seems that we ought to add the symbol value to the
5808 addend here, but in practice it has already been added
5809 because it was passed to constructor_callback. */
5810 addend += section->output_section->vma + section->output_offset;
5812 else if (h != NULL)
5814 /* Setting the index to -2 tells elf_link_output_extsym that
5815 this symbol is used by a reloc. */
5816 h->indx = -2;
5817 *rel_hash_ptr = h;
5818 indx = 0;
5820 else
5822 if (! ((*info->callbacks->unattached_reloc)
5823 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5824 (asection *) NULL, (bfd_vma) 0)))
5825 return false;
5826 indx = 0;
5830 /* If this is an inplace reloc, we must write the addend into the
5831 object file. */
5832 if (howto->partial_inplace && addend != 0)
5834 bfd_size_type size;
5835 bfd_reloc_status_type rstat;
5836 bfd_byte *buf;
5837 boolean ok;
5839 size = bfd_get_reloc_size (howto);
5840 buf = (bfd_byte *) bfd_zmalloc (size);
5841 if (buf == (bfd_byte *) NULL)
5842 return false;
5843 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5844 switch (rstat)
5846 case bfd_reloc_ok:
5847 break;
5848 default:
5849 case bfd_reloc_outofrange:
5850 abort ();
5851 case bfd_reloc_overflow:
5852 if (! ((*info->callbacks->reloc_overflow)
5853 (info,
5854 (link_order->type == bfd_section_reloc_link_order
5855 ? bfd_section_name (output_bfd,
5856 link_order->u.reloc.p->u.section)
5857 : link_order->u.reloc.p->u.name),
5858 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5859 (bfd_vma) 0)))
5861 free (buf);
5862 return false;
5864 break;
5866 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5867 (file_ptr) link_order->offset, size);
5868 free (buf);
5869 if (! ok)
5870 return false;
5873 /* The address of a reloc is relative to the section in a
5874 relocateable file, and is a virtual address in an executable
5875 file. */
5876 offset = link_order->offset;
5877 if (! info->relocateable)
5878 offset += output_section->vma;
5880 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5882 if (rel_hdr->sh_type == SHT_REL)
5884 Elf_Internal_Rel irel;
5885 Elf_External_Rel *erel;
5887 irel.r_offset = offset;
5888 irel.r_info = ELF_R_INFO (indx, howto->type);
5889 erel = ((Elf_External_Rel *) rel_hdr->contents
5890 + elf_section_data (output_section)->rel_count);
5891 if (bed->s->swap_reloc_out)
5892 (*bed->s->swap_reloc_out) (output_bfd, &irel, (bfd_byte *) erel);
5893 else
5894 elf_swap_reloc_out (output_bfd, &irel, erel);
5896 else
5898 Elf_Internal_Rela irela;
5899 Elf_External_Rela *erela;
5901 irela.r_offset = offset;
5902 irela.r_info = ELF_R_INFO (indx, howto->type);
5903 irela.r_addend = addend;
5904 erela = ((Elf_External_Rela *) rel_hdr->contents
5905 + elf_section_data (output_section)->rel_count);
5906 if (bed->s->swap_reloca_out)
5907 (*bed->s->swap_reloca_out) (output_bfd, &irela, (bfd_byte *) erela);
5908 else
5909 elf_swap_reloca_out (output_bfd, &irela, erela);
5912 ++elf_section_data (output_section)->rel_count;
5914 return true;
5918 /* Allocate a pointer to live in a linker created section. */
5920 boolean
5921 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5922 bfd *abfd;
5923 struct bfd_link_info *info;
5924 elf_linker_section_t *lsect;
5925 struct elf_link_hash_entry *h;
5926 const Elf_Internal_Rela *rel;
5928 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5929 elf_linker_section_pointers_t *linker_section_ptr;
5930 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5932 BFD_ASSERT (lsect != NULL);
5934 /* Is this a global symbol? */
5935 if (h != NULL)
5937 /* Has this symbol already been allocated, if so, our work is done */
5938 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5939 rel->r_addend,
5940 lsect->which))
5941 return true;
5943 ptr_linker_section_ptr = &h->linker_section_pointer;
5944 /* Make sure this symbol is output as a dynamic symbol. */
5945 if (h->dynindx == -1)
5947 if (! elf_link_record_dynamic_symbol (info, h))
5948 return false;
5951 if (lsect->rel_section)
5952 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5955 else /* Allocation of a pointer to a local symbol */
5957 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5959 /* Allocate a table to hold the local symbols if first time */
5960 if (!ptr)
5962 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5963 register unsigned int i;
5965 ptr = (elf_linker_section_pointers_t **)
5966 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5968 if (!ptr)
5969 return false;
5971 elf_local_ptr_offsets (abfd) = ptr;
5972 for (i = 0; i < num_symbols; i++)
5973 ptr[i] = (elf_linker_section_pointers_t *)0;
5976 /* Has this symbol already been allocated, if so, our work is done */
5977 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5978 rel->r_addend,
5979 lsect->which))
5980 return true;
5982 ptr_linker_section_ptr = &ptr[r_symndx];
5984 if (info->shared)
5986 /* If we are generating a shared object, we need to
5987 output a R_<xxx>_RELATIVE reloc so that the
5988 dynamic linker can adjust this GOT entry. */
5989 BFD_ASSERT (lsect->rel_section != NULL);
5990 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5994 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
5995 from internal memory. */
5996 BFD_ASSERT (ptr_linker_section_ptr != NULL);
5997 linker_section_ptr = (elf_linker_section_pointers_t *)
5998 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
6000 if (!linker_section_ptr)
6001 return false;
6003 linker_section_ptr->next = *ptr_linker_section_ptr;
6004 linker_section_ptr->addend = rel->r_addend;
6005 linker_section_ptr->which = lsect->which;
6006 linker_section_ptr->written_address_p = false;
6007 *ptr_linker_section_ptr = linker_section_ptr;
6009 #if 0
6010 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
6012 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
6013 lsect->hole_offset += ARCH_SIZE / 8;
6014 lsect->sym_offset += ARCH_SIZE / 8;
6015 if (lsect->sym_hash) /* Bump up symbol value if needed */
6017 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
6018 #ifdef DEBUG
6019 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
6020 lsect->sym_hash->root.root.string,
6021 (long)ARCH_SIZE / 8,
6022 (long)lsect->sym_hash->root.u.def.value);
6023 #endif
6026 else
6027 #endif
6028 linker_section_ptr->offset = lsect->section->_raw_size;
6030 lsect->section->_raw_size += ARCH_SIZE / 8;
6032 #ifdef DEBUG
6033 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
6034 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
6035 #endif
6037 return true;
6041 #if ARCH_SIZE==64
6042 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
6043 #endif
6044 #if ARCH_SIZE==32
6045 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
6046 #endif
6048 /* Fill in the address for a pointer generated in alinker section. */
6050 bfd_vma
6051 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
6052 bfd *output_bfd;
6053 bfd *input_bfd;
6054 struct bfd_link_info *info;
6055 elf_linker_section_t *lsect;
6056 struct elf_link_hash_entry *h;
6057 bfd_vma relocation;
6058 const Elf_Internal_Rela *rel;
6059 int relative_reloc;
6061 elf_linker_section_pointers_t *linker_section_ptr;
6063 BFD_ASSERT (lsect != NULL);
6065 if (h != NULL) /* global symbol */
6067 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6068 rel->r_addend,
6069 lsect->which);
6071 BFD_ASSERT (linker_section_ptr != NULL);
6073 if (! elf_hash_table (info)->dynamic_sections_created
6074 || (info->shared
6075 && info->symbolic
6076 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
6078 /* This is actually a static link, or it is a
6079 -Bsymbolic link and the symbol is defined
6080 locally. We must initialize this entry in the
6081 global section.
6083 When doing a dynamic link, we create a .rela.<xxx>
6084 relocation entry to initialize the value. This
6085 is done in the finish_dynamic_symbol routine. */
6086 if (!linker_section_ptr->written_address_p)
6088 linker_section_ptr->written_address_p = true;
6089 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6090 lsect->section->contents + linker_section_ptr->offset);
6094 else /* local symbol */
6096 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6097 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6098 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6099 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6100 rel->r_addend,
6101 lsect->which);
6103 BFD_ASSERT (linker_section_ptr != NULL);
6105 /* Write out pointer if it hasn't been rewritten out before */
6106 if (!linker_section_ptr->written_address_p)
6108 linker_section_ptr->written_address_p = true;
6109 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6110 lsect->section->contents + linker_section_ptr->offset);
6112 if (info->shared)
6114 asection *srel = lsect->rel_section;
6115 Elf_Internal_Rela outrel;
6117 /* We need to generate a relative reloc for the dynamic linker. */
6118 if (!srel)
6119 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6120 lsect->rel_name);
6122 BFD_ASSERT (srel != NULL);
6124 outrel.r_offset = (lsect->section->output_section->vma
6125 + lsect->section->output_offset
6126 + linker_section_ptr->offset);
6127 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6128 outrel.r_addend = 0;
6129 elf_swap_reloca_out (output_bfd, &outrel,
6130 (((Elf_External_Rela *)
6131 lsect->section->contents)
6132 + elf_section_data (lsect->section)->rel_count));
6133 ++elf_section_data (lsect->section)->rel_count;
6138 relocation = (lsect->section->output_offset
6139 + linker_section_ptr->offset
6140 - lsect->hole_offset
6141 - lsect->sym_offset);
6143 #ifdef DEBUG
6144 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6145 lsect->name, (long)relocation, (long)relocation);
6146 #endif
6148 /* Subtract out the addend, because it will get added back in by the normal
6149 processing. */
6150 return relocation - linker_section_ptr->addend;
6153 /* Garbage collect unused sections. */
6155 static boolean elf_gc_mark
6156 PARAMS ((struct bfd_link_info *info, asection *sec,
6157 asection * (*gc_mark_hook)
6158 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6159 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6161 static boolean elf_gc_sweep
6162 PARAMS ((struct bfd_link_info *info,
6163 boolean (*gc_sweep_hook)
6164 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6165 const Elf_Internal_Rela *relocs))));
6167 static boolean elf_gc_sweep_symbol
6168 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6170 static boolean elf_gc_allocate_got_offsets
6171 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6173 static boolean elf_gc_propagate_vtable_entries_used
6174 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6176 static boolean elf_gc_smash_unused_vtentry_relocs
6177 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6179 /* The mark phase of garbage collection. For a given section, mark
6180 it, and all the sections which define symbols to which it refers. */
6182 static boolean
6183 elf_gc_mark (info, sec, gc_mark_hook)
6184 struct bfd_link_info *info;
6185 asection *sec;
6186 asection * (*gc_mark_hook)
6187 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6188 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6190 boolean ret = true;
6192 sec->gc_mark = 1;
6194 /* Look through the section relocs. */
6196 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6198 Elf_Internal_Rela *relstart, *rel, *relend;
6199 Elf_Internal_Shdr *symtab_hdr;
6200 struct elf_link_hash_entry **sym_hashes;
6201 size_t nlocsyms;
6202 size_t extsymoff;
6203 Elf_External_Sym *locsyms, *freesyms = NULL;
6204 bfd *input_bfd = sec->owner;
6205 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6207 /* GCFIXME: how to arrange so that relocs and symbols are not
6208 reread continually? */
6210 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6211 sym_hashes = elf_sym_hashes (input_bfd);
6213 /* Read the local symbols. */
6214 if (elf_bad_symtab (input_bfd))
6216 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6217 extsymoff = 0;
6219 else
6220 extsymoff = nlocsyms = symtab_hdr->sh_info;
6221 if (symtab_hdr->contents)
6222 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6223 else if (nlocsyms == 0)
6224 locsyms = NULL;
6225 else
6227 locsyms = freesyms =
6228 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6229 if (freesyms == NULL
6230 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6231 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6232 nlocsyms, input_bfd)
6233 != nlocsyms * sizeof (Elf_External_Sym)))
6235 ret = false;
6236 goto out1;
6240 /* Read the relocations. */
6241 relstart = (NAME(_bfd_elf,link_read_relocs)
6242 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6243 info->keep_memory));
6244 if (relstart == NULL)
6246 ret = false;
6247 goto out1;
6249 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6251 for (rel = relstart; rel < relend; rel++)
6253 unsigned long r_symndx;
6254 asection *rsec;
6255 struct elf_link_hash_entry *h;
6256 Elf_Internal_Sym s;
6258 r_symndx = ELF_R_SYM (rel->r_info);
6259 if (r_symndx == 0)
6260 continue;
6262 if (elf_bad_symtab (sec->owner))
6264 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6265 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6266 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6267 else
6269 h = sym_hashes[r_symndx - extsymoff];
6270 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6273 else if (r_symndx >= nlocsyms)
6275 h = sym_hashes[r_symndx - extsymoff];
6276 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6278 else
6280 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6281 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6284 if (rsec && !rsec->gc_mark)
6285 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6287 ret = false;
6288 goto out2;
6292 out2:
6293 if (!info->keep_memory)
6294 free (relstart);
6295 out1:
6296 if (freesyms)
6297 free (freesyms);
6300 return ret;
6303 /* The sweep phase of garbage collection. Remove all garbage sections. */
6305 static boolean
6306 elf_gc_sweep (info, gc_sweep_hook)
6307 struct bfd_link_info *info;
6308 boolean (*gc_sweep_hook)
6309 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6310 const Elf_Internal_Rela *relocs));
6312 bfd *sub;
6314 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6316 asection *o;
6318 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6319 continue;
6321 for (o = sub->sections; o != NULL; o = o->next)
6323 /* Keep special sections. Keep .debug sections. */
6324 if ((o->flags & SEC_LINKER_CREATED)
6325 || (o->flags & SEC_DEBUGGING))
6326 o->gc_mark = 1;
6328 if (o->gc_mark)
6329 continue;
6331 /* Skip sweeping sections already excluded. */
6332 if (o->flags & SEC_EXCLUDE)
6333 continue;
6335 /* Since this is early in the link process, it is simple
6336 to remove a section from the output. */
6337 o->flags |= SEC_EXCLUDE;
6339 /* But we also have to update some of the relocation
6340 info we collected before. */
6341 if (gc_sweep_hook
6342 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6344 Elf_Internal_Rela *internal_relocs;
6345 boolean r;
6347 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6348 (o->owner, o, NULL, NULL, info->keep_memory));
6349 if (internal_relocs == NULL)
6350 return false;
6352 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
6354 if (!info->keep_memory)
6355 free (internal_relocs);
6357 if (!r)
6358 return false;
6363 /* Remove the symbols that were in the swept sections from the dynamic
6364 symbol table. GCFIXME: Anyone know how to get them out of the
6365 static symbol table as well? */
6367 int i = 0;
6369 elf_link_hash_traverse (elf_hash_table (info),
6370 elf_gc_sweep_symbol,
6371 (PTR) &i);
6373 elf_hash_table (info)->dynsymcount = i;
6376 return true;
6379 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6381 static boolean
6382 elf_gc_sweep_symbol (h, idxptr)
6383 struct elf_link_hash_entry *h;
6384 PTR idxptr;
6386 int *idx = (int *) idxptr;
6388 if (h->dynindx != -1
6389 && ((h->root.type != bfd_link_hash_defined
6390 && h->root.type != bfd_link_hash_defweak)
6391 || h->root.u.def.section->gc_mark))
6392 h->dynindx = (*idx)++;
6394 return true;
6397 /* Propogate collected vtable information. This is called through
6398 elf_link_hash_traverse. */
6400 static boolean
6401 elf_gc_propagate_vtable_entries_used (h, okp)
6402 struct elf_link_hash_entry *h;
6403 PTR okp;
6405 /* Those that are not vtables. */
6406 if (h->vtable_parent == NULL)
6407 return true;
6409 /* Those vtables that do not have parents, we cannot merge. */
6410 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6411 return true;
6413 /* If we've already been done, exit. */
6414 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6415 return true;
6417 /* Make sure the parent's table is up to date. */
6418 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6420 if (h->vtable_entries_used == NULL)
6422 /* None of this table's entries were referenced. Re-use the
6423 parent's table. */
6424 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6425 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6427 else
6429 size_t n;
6430 boolean *cu, *pu;
6432 /* Or the parent's entries into ours. */
6433 cu = h->vtable_entries_used;
6434 cu[-1] = true;
6435 pu = h->vtable_parent->vtable_entries_used;
6436 if (pu != NULL)
6438 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6439 while (--n != 0)
6441 if (*pu) *cu = true;
6442 pu++, cu++;
6447 return true;
6450 static boolean
6451 elf_gc_smash_unused_vtentry_relocs (h, okp)
6452 struct elf_link_hash_entry *h;
6453 PTR okp;
6455 asection *sec;
6456 bfd_vma hstart, hend;
6457 Elf_Internal_Rela *relstart, *relend, *rel;
6458 struct elf_backend_data *bed;
6460 /* Take care of both those symbols that do not describe vtables as
6461 well as those that are not loaded. */
6462 if (h->vtable_parent == NULL)
6463 return true;
6465 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6466 || h->root.type == bfd_link_hash_defweak);
6468 sec = h->root.u.def.section;
6469 hstart = h->root.u.def.value;
6470 hend = hstart + h->size;
6472 relstart = (NAME(_bfd_elf,link_read_relocs)
6473 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6474 if (!relstart)
6475 return *(boolean *)okp = false;
6476 bed = get_elf_backend_data (sec->owner);
6477 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6479 for (rel = relstart; rel < relend; ++rel)
6480 if (rel->r_offset >= hstart && rel->r_offset < hend)
6482 /* If the entry is in use, do nothing. */
6483 if (h->vtable_entries_used
6484 && (rel->r_offset - hstart) < h->vtable_entries_size)
6486 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6487 if (h->vtable_entries_used[entry])
6488 continue;
6490 /* Otherwise, kill it. */
6491 rel->r_offset = rel->r_info = rel->r_addend = 0;
6494 return true;
6497 /* Do mark and sweep of unused sections. */
6499 boolean
6500 elf_gc_sections (abfd, info)
6501 bfd *abfd;
6502 struct bfd_link_info *info;
6504 boolean ok = true;
6505 bfd *sub;
6506 asection * (*gc_mark_hook)
6507 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6508 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6510 if (!get_elf_backend_data (abfd)->can_gc_sections
6511 || info->relocateable || info->emitrelocations
6512 || elf_hash_table (info)->dynamic_sections_created)
6513 return true;
6515 /* Apply transitive closure to the vtable entry usage info. */
6516 elf_link_hash_traverse (elf_hash_table (info),
6517 elf_gc_propagate_vtable_entries_used,
6518 (PTR) &ok);
6519 if (!ok)
6520 return false;
6522 /* Kill the vtable relocations that were not used. */
6523 elf_link_hash_traverse (elf_hash_table (info),
6524 elf_gc_smash_unused_vtentry_relocs,
6525 (PTR) &ok);
6526 if (!ok)
6527 return false;
6529 /* Grovel through relocs to find out who stays ... */
6531 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6532 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6534 asection *o;
6536 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6537 continue;
6539 for (o = sub->sections; o != NULL; o = o->next)
6541 if (o->flags & SEC_KEEP)
6542 if (!elf_gc_mark (info, o, gc_mark_hook))
6543 return false;
6547 /* ... and mark SEC_EXCLUDE for those that go. */
6548 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6549 return false;
6551 return true;
6554 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6556 boolean
6557 elf_gc_record_vtinherit (abfd, sec, h, offset)
6558 bfd *abfd;
6559 asection *sec;
6560 struct elf_link_hash_entry *h;
6561 bfd_vma offset;
6563 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6564 struct elf_link_hash_entry **search, *child;
6565 bfd_size_type extsymcount;
6567 /* The sh_info field of the symtab header tells us where the
6568 external symbols start. We don't care about the local symbols at
6569 this point. */
6570 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6571 if (!elf_bad_symtab (abfd))
6572 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6574 sym_hashes = elf_sym_hashes (abfd);
6575 sym_hashes_end = sym_hashes + extsymcount;
6577 /* Hunt down the child symbol, which is in this section at the same
6578 offset as the relocation. */
6579 for (search = sym_hashes; search != sym_hashes_end; ++search)
6581 if ((child = *search) != NULL
6582 && (child->root.type == bfd_link_hash_defined
6583 || child->root.type == bfd_link_hash_defweak)
6584 && child->root.u.def.section == sec
6585 && child->root.u.def.value == offset)
6586 goto win;
6589 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6590 bfd_get_filename (abfd), sec->name,
6591 (unsigned long)offset);
6592 bfd_set_error (bfd_error_invalid_operation);
6593 return false;
6595 win:
6596 if (!h)
6598 /* This *should* only be the absolute section. It could potentially
6599 be that someone has defined a non-global vtable though, which
6600 would be bad. It isn't worth paging in the local symbols to be
6601 sure though; that case should simply be handled by the assembler. */
6603 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6605 else
6606 child->vtable_parent = h;
6608 return true;
6611 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6613 boolean
6614 elf_gc_record_vtentry (abfd, sec, h, addend)
6615 bfd *abfd ATTRIBUTE_UNUSED;
6616 asection *sec ATTRIBUTE_UNUSED;
6617 struct elf_link_hash_entry *h;
6618 bfd_vma addend;
6620 if (addend >= h->vtable_entries_size)
6622 size_t size, bytes;
6623 boolean *ptr = h->vtable_entries_used;
6625 /* While the symbol is undefined, we have to be prepared to handle
6626 a zero size. */
6627 if (h->root.type == bfd_link_hash_undefined)
6628 size = addend;
6629 else
6631 size = h->size;
6632 if (size < addend)
6634 /* Oops! We've got a reference past the defined end of
6635 the table. This is probably a bug -- shall we warn? */
6636 size = addend;
6640 /* Allocate one extra entry for use as a "done" flag for the
6641 consolidation pass. */
6642 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6644 if (ptr)
6646 ptr = bfd_realloc (ptr - 1, bytes);
6648 if (ptr != NULL)
6650 size_t oldbytes;
6652 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6653 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6656 else
6657 ptr = bfd_zmalloc (bytes);
6659 if (ptr == NULL)
6660 return false;
6662 /* And arrange for that done flag to be at index -1. */
6663 h->vtable_entries_used = ptr + 1;
6664 h->vtable_entries_size = size;
6667 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6669 return true;
6672 /* And an accompanying bit to work out final got entry offsets once
6673 we're done. Should be called from final_link. */
6675 boolean
6676 elf_gc_common_finalize_got_offsets (abfd, info)
6677 bfd *abfd;
6678 struct bfd_link_info *info;
6680 bfd *i;
6681 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6682 bfd_vma gotoff;
6684 /* The GOT offset is relative to the .got section, but the GOT header is
6685 put into the .got.plt section, if the backend uses it. */
6686 if (bed->want_got_plt)
6687 gotoff = 0;
6688 else
6689 gotoff = bed->got_header_size;
6691 /* Do the local .got entries first. */
6692 for (i = info->input_bfds; i; i = i->link_next)
6694 bfd_signed_vma *local_got;
6695 bfd_size_type j, locsymcount;
6696 Elf_Internal_Shdr *symtab_hdr;
6698 if (bfd_get_flavour (i) != bfd_target_elf_flavour)
6699 continue;
6701 local_got = elf_local_got_refcounts (i);
6702 if (!local_got)
6703 continue;
6705 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6706 if (elf_bad_symtab (i))
6707 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6708 else
6709 locsymcount = symtab_hdr->sh_info;
6711 for (j = 0; j < locsymcount; ++j)
6713 if (local_got[j] > 0)
6715 local_got[j] = gotoff;
6716 gotoff += ARCH_SIZE / 8;
6718 else
6719 local_got[j] = (bfd_vma) -1;
6723 /* Then the global .got entries. .plt refcounts are handled by
6724 adjust_dynamic_symbol */
6725 elf_link_hash_traverse (elf_hash_table (info),
6726 elf_gc_allocate_got_offsets,
6727 (PTR) &gotoff);
6728 return true;
6731 /* We need a special top-level link routine to convert got reference counts
6732 to real got offsets. */
6734 static boolean
6735 elf_gc_allocate_got_offsets (h, offarg)
6736 struct elf_link_hash_entry *h;
6737 PTR offarg;
6739 bfd_vma *off = (bfd_vma *) offarg;
6741 if (h->got.refcount > 0)
6743 h->got.offset = off[0];
6744 off[0] += ARCH_SIZE / 8;
6746 else
6747 h->got.offset = (bfd_vma) -1;
6749 return true;
6752 /* Many folk need no more in the way of final link than this, once
6753 got entry reference counting is enabled. */
6755 boolean
6756 elf_gc_common_final_link (abfd, info)
6757 bfd *abfd;
6758 struct bfd_link_info *info;
6760 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6761 return false;
6763 /* Invoke the regular ELF backend linker to do all the work. */
6764 return elf_bfd_final_link (abfd, info);
6767 /* This function will be called though elf_link_hash_traverse to store
6768 all hash value of the exported symbols in an array. */
6770 static boolean
6771 elf_collect_hash_codes (h, data)
6772 struct elf_link_hash_entry *h;
6773 PTR data;
6775 unsigned long **valuep = (unsigned long **) data;
6776 const char *name;
6777 char *p;
6778 unsigned long ha;
6779 char *alc = NULL;
6781 /* Ignore indirect symbols. These are added by the versioning code. */
6782 if (h->dynindx == -1)
6783 return true;
6785 name = h->root.root.string;
6786 p = strchr (name, ELF_VER_CHR);
6787 if (p != NULL)
6789 alc = bfd_malloc (p - name + 1);
6790 memcpy (alc, name, p - name);
6791 alc[p - name] = '\0';
6792 name = alc;
6795 /* Compute the hash value. */
6796 ha = bfd_elf_hash (name);
6798 /* Store the found hash value in the array given as the argument. */
6799 *(*valuep)++ = ha;
6801 /* And store it in the struct so that we can put it in the hash table
6802 later. */
6803 h->elf_hash_value = ha;
6805 if (alc != NULL)
6806 free (alc);
6808 return true;