2000-07-20 H.J. Lu <hjl@gnu.org>
[binutils.git] / bfd / elflink.h
blob5e74a5f427237bff5e263760d4706b2d03f3e691
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;
2840 info->flags |= DF_SYMBOLIC;
2843 if (rpath != NULL)
2845 bfd_size_type indx;
2847 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2848 true, true);
2849 if (indx == (bfd_size_type) -1
2850 || ! elf_add_dynamic_entry (info, DT_RPATH, indx)
2851 || (info->new_dtags
2852 && ! elf_add_dynamic_entry (info, DT_RUNPATH, indx)))
2853 return false;
2856 if (filter_shlib != NULL)
2858 bfd_size_type indx;
2860 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2861 filter_shlib, true, true);
2862 if (indx == (bfd_size_type) -1
2863 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2864 return false;
2867 if (auxiliary_filters != NULL)
2869 const char * const *p;
2871 for (p = auxiliary_filters; *p != NULL; p++)
2873 bfd_size_type indx;
2875 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2876 *p, true, true);
2877 if (indx == (bfd_size_type) -1
2878 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2879 return false;
2883 /* If we are supposed to export all symbols into the dynamic symbol
2884 table (this is not the normal case), then do so. */
2885 if (export_dynamic)
2887 struct elf_info_failed eif;
2889 eif.failed = false;
2890 eif.info = info;
2891 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2892 (PTR) &eif);
2893 if (eif.failed)
2894 return false;
2897 /* Attach all the symbols to their version information. */
2898 asvinfo.output_bfd = output_bfd;
2899 asvinfo.info = info;
2900 asvinfo.verdefs = verdefs;
2901 asvinfo.export_dynamic = export_dynamic;
2902 asvinfo.failed = false;
2904 elf_link_hash_traverse (elf_hash_table (info),
2905 elf_link_assign_sym_version,
2906 (PTR) &asvinfo);
2907 if (asvinfo.failed)
2908 return false;
2910 /* Find all symbols which were defined in a dynamic object and make
2911 the backend pick a reasonable value for them. */
2912 eif.failed = false;
2913 eif.info = info;
2914 elf_link_hash_traverse (elf_hash_table (info),
2915 elf_adjust_dynamic_symbol,
2916 (PTR) &eif);
2917 if (eif.failed)
2918 return false;
2920 /* Add some entries to the .dynamic section. We fill in some of the
2921 values later, in elf_bfd_final_link, but we must add the entries
2922 now so that we know the final size of the .dynamic section. */
2924 /* If there are initialization and/or finalization functions to
2925 call then add the corresponding DT_INIT/DT_FINI entries. */
2926 h = (info->init_function
2927 ? elf_link_hash_lookup (elf_hash_table (info),
2928 info->init_function, false,
2929 false, false)
2930 : NULL);
2931 if (h != NULL
2932 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2933 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2935 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2936 return false;
2938 h = (info->fini_function
2939 ? elf_link_hash_lookup (elf_hash_table (info),
2940 info->fini_function, false,
2941 false, false)
2942 : NULL);
2943 if (h != NULL
2944 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2945 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2947 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2948 return false;
2951 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2952 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2953 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2954 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2955 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2956 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2957 sizeof (Elf_External_Sym)))
2958 return false;
2961 /* The backend must work out the sizes of all the other dynamic
2962 sections. */
2963 if (bed->elf_backend_size_dynamic_sections
2964 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2965 return false;
2967 if (elf_hash_table (info)->dynamic_sections_created)
2969 size_t dynsymcount;
2970 asection *s;
2971 size_t bucketcount = 0;
2972 Elf_Internal_Sym isym;
2973 size_t hash_entry_size;
2975 /* Set up the version definition section. */
2976 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2977 BFD_ASSERT (s != NULL);
2979 /* We may have created additional version definitions if we are
2980 just linking a regular application. */
2981 verdefs = asvinfo.verdefs;
2983 if (verdefs == NULL)
2984 _bfd_strip_section_from_output (info, s);
2985 else
2987 unsigned int cdefs;
2988 bfd_size_type size;
2989 struct bfd_elf_version_tree *t;
2990 bfd_byte *p;
2991 Elf_Internal_Verdef def;
2992 Elf_Internal_Verdaux defaux;
2994 cdefs = 0;
2995 size = 0;
2997 /* Make space for the base version. */
2998 size += sizeof (Elf_External_Verdef);
2999 size += sizeof (Elf_External_Verdaux);
3000 ++cdefs;
3002 for (t = verdefs; t != NULL; t = t->next)
3004 struct bfd_elf_version_deps *n;
3006 size += sizeof (Elf_External_Verdef);
3007 size += sizeof (Elf_External_Verdaux);
3008 ++cdefs;
3010 for (n = t->deps; n != NULL; n = n->next)
3011 size += sizeof (Elf_External_Verdaux);
3014 s->_raw_size = size;
3015 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3016 if (s->contents == NULL && s->_raw_size != 0)
3017 return false;
3019 /* Fill in the version definition section. */
3021 p = s->contents;
3023 def.vd_version = VER_DEF_CURRENT;
3024 def.vd_flags = VER_FLG_BASE;
3025 def.vd_ndx = 1;
3026 def.vd_cnt = 1;
3027 def.vd_aux = sizeof (Elf_External_Verdef);
3028 def.vd_next = (sizeof (Elf_External_Verdef)
3029 + sizeof (Elf_External_Verdaux));
3031 if (soname_indx != (bfd_size_type) -1)
3033 def.vd_hash = bfd_elf_hash (soname);
3034 defaux.vda_name = soname_indx;
3036 else
3038 const char *name;
3039 bfd_size_type indx;
3041 name = output_bfd->filename;
3042 def.vd_hash = bfd_elf_hash (name);
3043 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3044 name, true, false);
3045 if (indx == (bfd_size_type) -1)
3046 return false;
3047 defaux.vda_name = indx;
3049 defaux.vda_next = 0;
3051 _bfd_elf_swap_verdef_out (output_bfd, &def,
3052 (Elf_External_Verdef *)p);
3053 p += sizeof (Elf_External_Verdef);
3054 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3055 (Elf_External_Verdaux *) p);
3056 p += sizeof (Elf_External_Verdaux);
3058 for (t = verdefs; t != NULL; t = t->next)
3060 unsigned int cdeps;
3061 struct bfd_elf_version_deps *n;
3062 struct elf_link_hash_entry *h;
3064 cdeps = 0;
3065 for (n = t->deps; n != NULL; n = n->next)
3066 ++cdeps;
3068 /* Add a symbol representing this version. */
3069 h = NULL;
3070 if (! (_bfd_generic_link_add_one_symbol
3071 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3072 (bfd_vma) 0, (const char *) NULL, false,
3073 get_elf_backend_data (dynobj)->collect,
3074 (struct bfd_link_hash_entry **) &h)))
3075 return false;
3076 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3077 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3078 h->type = STT_OBJECT;
3079 h->verinfo.vertree = t;
3081 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3082 return false;
3084 def.vd_version = VER_DEF_CURRENT;
3085 def.vd_flags = 0;
3086 if (t->globals == NULL && t->locals == NULL && ! t->used)
3087 def.vd_flags |= VER_FLG_WEAK;
3088 def.vd_ndx = t->vernum + 1;
3089 def.vd_cnt = cdeps + 1;
3090 def.vd_hash = bfd_elf_hash (t->name);
3091 def.vd_aux = sizeof (Elf_External_Verdef);
3092 if (t->next != NULL)
3093 def.vd_next = (sizeof (Elf_External_Verdef)
3094 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3095 else
3096 def.vd_next = 0;
3098 _bfd_elf_swap_verdef_out (output_bfd, &def,
3099 (Elf_External_Verdef *) p);
3100 p += sizeof (Elf_External_Verdef);
3102 defaux.vda_name = h->dynstr_index;
3103 if (t->deps == NULL)
3104 defaux.vda_next = 0;
3105 else
3106 defaux.vda_next = sizeof (Elf_External_Verdaux);
3107 t->name_indx = defaux.vda_name;
3109 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3110 (Elf_External_Verdaux *) p);
3111 p += sizeof (Elf_External_Verdaux);
3113 for (n = t->deps; n != NULL; n = n->next)
3115 if (n->version_needed == NULL)
3117 /* This can happen if there was an error in the
3118 version script. */
3119 defaux.vda_name = 0;
3121 else
3122 defaux.vda_name = n->version_needed->name_indx;
3123 if (n->next == NULL)
3124 defaux.vda_next = 0;
3125 else
3126 defaux.vda_next = sizeof (Elf_External_Verdaux);
3128 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3129 (Elf_External_Verdaux *) p);
3130 p += sizeof (Elf_External_Verdaux);
3134 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3135 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3136 return false;
3138 elf_tdata (output_bfd)->cverdefs = cdefs;
3141 if (info->new_dtags && info->flags)
3143 if (! elf_add_dynamic_entry (info, DT_FLAGS, info->flags))
3144 return false;
3147 if (info->new_dtags && info->flags_1)
3149 if (! info->shared)
3150 info->flags_1 &= ~ (DF_1_INITFIRST
3151 | DF_1_NODELETE
3152 | DF_1_NOOPEN);
3153 if (! elf_add_dynamic_entry (info, DT_FLAGS_1, info->flags_1))
3154 return false;
3157 /* Work out the size of the version reference section. */
3159 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3160 BFD_ASSERT (s != NULL);
3162 struct elf_find_verdep_info sinfo;
3164 sinfo.output_bfd = output_bfd;
3165 sinfo.info = info;
3166 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3167 if (sinfo.vers == 0)
3168 sinfo.vers = 1;
3169 sinfo.failed = false;
3171 elf_link_hash_traverse (elf_hash_table (info),
3172 elf_link_find_version_dependencies,
3173 (PTR) &sinfo);
3175 if (elf_tdata (output_bfd)->verref == NULL)
3176 _bfd_strip_section_from_output (info, s);
3177 else
3179 Elf_Internal_Verneed *t;
3180 unsigned int size;
3181 unsigned int crefs;
3182 bfd_byte *p;
3184 /* Build the version definition section. */
3185 size = 0;
3186 crefs = 0;
3187 for (t = elf_tdata (output_bfd)->verref;
3188 t != NULL;
3189 t = t->vn_nextref)
3191 Elf_Internal_Vernaux *a;
3193 size += sizeof (Elf_External_Verneed);
3194 ++crefs;
3195 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3196 size += sizeof (Elf_External_Vernaux);
3199 s->_raw_size = size;
3200 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3201 if (s->contents == NULL)
3202 return false;
3204 p = s->contents;
3205 for (t = elf_tdata (output_bfd)->verref;
3206 t != NULL;
3207 t = t->vn_nextref)
3209 unsigned int caux;
3210 Elf_Internal_Vernaux *a;
3211 bfd_size_type indx;
3213 caux = 0;
3214 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3215 ++caux;
3217 t->vn_version = VER_NEED_CURRENT;
3218 t->vn_cnt = caux;
3219 if (elf_dt_name (t->vn_bfd) != NULL)
3220 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3221 elf_dt_name (t->vn_bfd),
3222 true, false);
3223 else
3224 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3225 t->vn_bfd->filename, true, false);
3226 if (indx == (bfd_size_type) -1)
3227 return false;
3228 t->vn_file = indx;
3229 t->vn_aux = sizeof (Elf_External_Verneed);
3230 if (t->vn_nextref == NULL)
3231 t->vn_next = 0;
3232 else
3233 t->vn_next = (sizeof (Elf_External_Verneed)
3234 + caux * sizeof (Elf_External_Vernaux));
3236 _bfd_elf_swap_verneed_out (output_bfd, t,
3237 (Elf_External_Verneed *) p);
3238 p += sizeof (Elf_External_Verneed);
3240 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3242 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3243 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3244 a->vna_nodename, true, false);
3245 if (indx == (bfd_size_type) -1)
3246 return false;
3247 a->vna_name = indx;
3248 if (a->vna_nextptr == NULL)
3249 a->vna_next = 0;
3250 else
3251 a->vna_next = sizeof (Elf_External_Vernaux);
3253 _bfd_elf_swap_vernaux_out (output_bfd, a,
3254 (Elf_External_Vernaux *) p);
3255 p += sizeof (Elf_External_Vernaux);
3259 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3260 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3261 return false;
3263 elf_tdata (output_bfd)->cverrefs = crefs;
3267 /* Assign dynsym indicies. In a shared library we generate a
3268 section symbol for each output section, which come first.
3269 Next come all of the back-end allocated local dynamic syms,
3270 followed by the rest of the global symbols. */
3272 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3274 /* Work out the size of the symbol version section. */
3275 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3276 BFD_ASSERT (s != NULL);
3277 if (dynsymcount == 0
3278 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3280 _bfd_strip_section_from_output (info, s);
3281 /* The DYNSYMCOUNT might have changed if we were going to
3282 output a dynamic symbol table entry for S. */
3283 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3285 else
3287 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3288 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3289 if (s->contents == NULL)
3290 return false;
3292 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3293 return false;
3296 /* Set the size of the .dynsym and .hash sections. We counted
3297 the number of dynamic symbols in elf_link_add_object_symbols.
3298 We will build the contents of .dynsym and .hash when we build
3299 the final symbol table, because until then we do not know the
3300 correct value to give the symbols. We built the .dynstr
3301 section as we went along in elf_link_add_object_symbols. */
3302 s = bfd_get_section_by_name (dynobj, ".dynsym");
3303 BFD_ASSERT (s != NULL);
3304 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3305 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3306 if (s->contents == NULL && s->_raw_size != 0)
3307 return false;
3309 /* The first entry in .dynsym is a dummy symbol. */
3310 isym.st_value = 0;
3311 isym.st_size = 0;
3312 isym.st_name = 0;
3313 isym.st_info = 0;
3314 isym.st_other = 0;
3315 isym.st_shndx = 0;
3316 elf_swap_symbol_out (output_bfd, &isym,
3317 (PTR) (Elf_External_Sym *) s->contents);
3319 /* Compute the size of the hashing table. As a side effect this
3320 computes the hash values for all the names we export. */
3321 bucketcount = compute_bucket_count (info);
3323 s = bfd_get_section_by_name (dynobj, ".hash");
3324 BFD_ASSERT (s != NULL);
3325 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3326 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3327 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3328 if (s->contents == NULL)
3329 return false;
3330 memset (s->contents, 0, (size_t) s->_raw_size);
3332 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3333 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3334 s->contents + hash_entry_size);
3336 elf_hash_table (info)->bucketcount = bucketcount;
3338 s = bfd_get_section_by_name (dynobj, ".dynstr");
3339 BFD_ASSERT (s != NULL);
3340 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3342 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3343 return false;
3346 return true;
3349 /* Fix up the flags for a symbol. This handles various cases which
3350 can only be fixed after all the input files are seen. This is
3351 currently called by both adjust_dynamic_symbol and
3352 assign_sym_version, which is unnecessary but perhaps more robust in
3353 the face of future changes. */
3355 static boolean
3356 elf_fix_symbol_flags (h, eif)
3357 struct elf_link_hash_entry *h;
3358 struct elf_info_failed *eif;
3360 /* If this symbol was mentioned in a non-ELF file, try to set
3361 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3362 permit a non-ELF file to correctly refer to a symbol defined in
3363 an ELF dynamic object. */
3364 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3366 while (h->root.type == bfd_link_hash_indirect)
3367 h = (struct elf_link_hash_entry *) h->root.u.i.link;
3369 if (h->root.type != bfd_link_hash_defined
3370 && h->root.type != bfd_link_hash_defweak)
3371 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3372 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3373 else
3375 if (h->root.u.def.section->owner != NULL
3376 && (bfd_get_flavour (h->root.u.def.section->owner)
3377 == bfd_target_elf_flavour))
3378 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3379 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3380 else
3381 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3384 if (h->dynindx == -1
3385 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3386 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3388 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3390 eif->failed = true;
3391 return false;
3395 else
3397 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3398 was first seen in a non-ELF file. Fortunately, if the symbol
3399 was first seen in an ELF file, we're probably OK unless the
3400 symbol was defined in a non-ELF file. Catch that case here.
3401 FIXME: We're still in trouble if the symbol was first seen in
3402 a dynamic object, and then later in a non-ELF regular object. */
3403 if ((h->root.type == bfd_link_hash_defined
3404 || h->root.type == bfd_link_hash_defweak)
3405 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3406 && (h->root.u.def.section->owner != NULL
3407 ? (bfd_get_flavour (h->root.u.def.section->owner)
3408 != bfd_target_elf_flavour)
3409 : (bfd_is_abs_section (h->root.u.def.section)
3410 && (h->elf_link_hash_flags
3411 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3412 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3415 /* If this is a final link, and the symbol was defined as a common
3416 symbol in a regular object file, and there was no definition in
3417 any dynamic object, then the linker will have allocated space for
3418 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3419 flag will not have been set. */
3420 if (h->root.type == bfd_link_hash_defined
3421 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3422 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3423 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3424 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3425 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3427 /* If -Bsymbolic was used (which means to bind references to global
3428 symbols to the definition within the shared object), and this
3429 symbol was defined in a regular object, then it actually doesn't
3430 need a PLT entry. Likewise, if the symbol has any kind of
3431 visibility (internal, hidden, or protected), it doesn't need a
3432 PLT. */
3433 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3434 && eif->info->shared
3435 && (eif->info->symbolic || ELF_ST_VISIBILITY (h->other))
3436 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3438 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3439 h->plt.offset = (bfd_vma) -1;
3442 /* If this is a weak defined symbol in a dynamic object, and we know
3443 the real definition in the dynamic object, copy interesting flags
3444 over to the real definition. */
3445 if (h->weakdef != NULL)
3447 struct elf_link_hash_entry *weakdef;
3449 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3450 || h->root.type == bfd_link_hash_defweak);
3451 weakdef = h->weakdef;
3452 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3453 || weakdef->root.type == bfd_link_hash_defweak);
3454 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3456 /* If the real definition is defined by a regular object file,
3457 don't do anything special. See the longer description in
3458 elf_adjust_dynamic_symbol, below. */
3459 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3460 h->weakdef = NULL;
3461 else
3462 weakdef->elf_link_hash_flags |=
3463 (h->elf_link_hash_flags
3464 & (ELF_LINK_HASH_REF_REGULAR
3465 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3466 | ELF_LINK_NON_GOT_REF));
3469 return true;
3472 /* Make the backend pick a good value for a dynamic symbol. This is
3473 called via elf_link_hash_traverse, and also calls itself
3474 recursively. */
3476 static boolean
3477 elf_adjust_dynamic_symbol (h, data)
3478 struct elf_link_hash_entry *h;
3479 PTR data;
3481 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3482 bfd *dynobj;
3483 struct elf_backend_data *bed;
3485 /* Ignore indirect symbols. These are added by the versioning code. */
3486 if (h->root.type == bfd_link_hash_indirect)
3487 return true;
3489 /* Fix the symbol flags. */
3490 if (! elf_fix_symbol_flags (h, eif))
3491 return false;
3493 /* If this symbol does not require a PLT entry, and it is not
3494 defined by a dynamic object, or is not referenced by a regular
3495 object, ignore it. We do have to handle a weak defined symbol,
3496 even if no regular object refers to it, if we decided to add it
3497 to the dynamic symbol table. FIXME: Do we normally need to worry
3498 about symbols which are defined by one dynamic object and
3499 referenced by another one? */
3500 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3501 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3502 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3503 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3504 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3506 h->plt.offset = (bfd_vma) -1;
3507 return true;
3510 /* If we've already adjusted this symbol, don't do it again. This
3511 can happen via a recursive call. */
3512 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3513 return true;
3515 /* Don't look at this symbol again. Note that we must set this
3516 after checking the above conditions, because we may look at a
3517 symbol once, decide not to do anything, and then get called
3518 recursively later after REF_REGULAR is set below. */
3519 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3521 /* If this is a weak definition, and we know a real definition, and
3522 the real symbol is not itself defined by a regular object file,
3523 then get a good value for the real definition. We handle the
3524 real symbol first, for the convenience of the backend routine.
3526 Note that there is a confusing case here. If the real definition
3527 is defined by a regular object file, we don't get the real symbol
3528 from the dynamic object, but we do get the weak symbol. If the
3529 processor backend uses a COPY reloc, then if some routine in the
3530 dynamic object changes the real symbol, we will not see that
3531 change in the corresponding weak symbol. This is the way other
3532 ELF linkers work as well, and seems to be a result of the shared
3533 library model.
3535 I will clarify this issue. Most SVR4 shared libraries define the
3536 variable _timezone and define timezone as a weak synonym. The
3537 tzset call changes _timezone. If you write
3538 extern int timezone;
3539 int _timezone = 5;
3540 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3541 you might expect that, since timezone is a synonym for _timezone,
3542 the same number will print both times. However, if the processor
3543 backend uses a COPY reloc, then actually timezone will be copied
3544 into your process image, and, since you define _timezone
3545 yourself, _timezone will not. Thus timezone and _timezone will
3546 wind up at different memory locations. The tzset call will set
3547 _timezone, leaving timezone unchanged. */
3549 if (h->weakdef != NULL)
3551 /* If we get to this point, we know there is an implicit
3552 reference by a regular object file via the weak symbol H.
3553 FIXME: Is this really true? What if the traversal finds
3554 H->WEAKDEF before it finds H? */
3555 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3557 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3558 return false;
3561 /* If a symbol has no type and no size and does not require a PLT
3562 entry, then we are probably about to do the wrong thing here: we
3563 are probably going to create a COPY reloc for an empty object.
3564 This case can arise when a shared object is built with assembly
3565 code, and the assembly code fails to set the symbol type. */
3566 if (h->size == 0
3567 && h->type == STT_NOTYPE
3568 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3569 (*_bfd_error_handler)
3570 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3571 h->root.root.string);
3573 dynobj = elf_hash_table (eif->info)->dynobj;
3574 bed = get_elf_backend_data (dynobj);
3575 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3577 eif->failed = true;
3578 return false;
3581 return true;
3584 /* This routine is used to export all defined symbols into the dynamic
3585 symbol table. It is called via elf_link_hash_traverse. */
3587 static boolean
3588 elf_export_symbol (h, data)
3589 struct elf_link_hash_entry *h;
3590 PTR data;
3592 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3594 /* Ignore indirect symbols. These are added by the versioning code. */
3595 if (h->root.type == bfd_link_hash_indirect)
3596 return true;
3598 if (h->dynindx == -1
3599 && (h->elf_link_hash_flags
3600 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3602 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3604 eif->failed = true;
3605 return false;
3609 return true;
3612 /* Look through the symbols which are defined in other shared
3613 libraries and referenced here. Update the list of version
3614 dependencies. This will be put into the .gnu.version_r section.
3615 This function is called via elf_link_hash_traverse. */
3617 static boolean
3618 elf_link_find_version_dependencies (h, data)
3619 struct elf_link_hash_entry *h;
3620 PTR data;
3622 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3623 Elf_Internal_Verneed *t;
3624 Elf_Internal_Vernaux *a;
3626 /* We only care about symbols defined in shared objects with version
3627 information. */
3628 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3629 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3630 || h->dynindx == -1
3631 || h->verinfo.verdef == NULL)
3632 return true;
3634 /* See if we already know about this version. */
3635 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3637 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3638 continue;
3640 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3641 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3642 return true;
3644 break;
3647 /* This is a new version. Add it to tree we are building. */
3649 if (t == NULL)
3651 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3652 if (t == NULL)
3654 rinfo->failed = true;
3655 return false;
3658 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3659 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3660 elf_tdata (rinfo->output_bfd)->verref = t;
3663 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3665 /* Note that we are copying a string pointer here, and testing it
3666 above. If bfd_elf_string_from_elf_section is ever changed to
3667 discard the string data when low in memory, this will have to be
3668 fixed. */
3669 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3671 a->vna_flags = h->verinfo.verdef->vd_flags;
3672 a->vna_nextptr = t->vn_auxptr;
3674 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3675 ++rinfo->vers;
3677 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3679 t->vn_auxptr = a;
3681 return true;
3684 /* Figure out appropriate versions for all the symbols. We may not
3685 have the version number script until we have read all of the input
3686 files, so until that point we don't know which symbols should be
3687 local. This function is called via elf_link_hash_traverse. */
3689 static boolean
3690 elf_link_assign_sym_version (h, data)
3691 struct elf_link_hash_entry *h;
3692 PTR data;
3694 struct elf_assign_sym_version_info *sinfo =
3695 (struct elf_assign_sym_version_info *) data;
3696 struct bfd_link_info *info = sinfo->info;
3697 struct elf_backend_data *bed;
3698 struct elf_info_failed eif;
3699 char *p;
3701 /* Fix the symbol flags. */
3702 eif.failed = false;
3703 eif.info = info;
3704 if (! elf_fix_symbol_flags (h, &eif))
3706 if (eif.failed)
3707 sinfo->failed = true;
3708 return false;
3711 /* We only need version numbers for symbols defined in regular
3712 objects. */
3713 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3714 return true;
3716 bed = get_elf_backend_data (sinfo->output_bfd);
3717 p = strchr (h->root.root.string, ELF_VER_CHR);
3718 if (p != NULL && h->verinfo.vertree == NULL)
3720 struct bfd_elf_version_tree *t;
3721 boolean hidden;
3723 hidden = true;
3725 /* There are two consecutive ELF_VER_CHR characters if this is
3726 not a hidden symbol. */
3727 ++p;
3728 if (*p == ELF_VER_CHR)
3730 hidden = false;
3731 ++p;
3734 /* If there is no version string, we can just return out. */
3735 if (*p == '\0')
3737 if (hidden)
3738 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3739 return true;
3742 /* Look for the version. If we find it, it is no longer weak. */
3743 for (t = sinfo->verdefs; t != NULL; t = t->next)
3745 if (strcmp (t->name, p) == 0)
3747 int len;
3748 char *alc;
3749 struct bfd_elf_version_expr *d;
3751 len = p - h->root.root.string;
3752 alc = bfd_alloc (sinfo->output_bfd, len);
3753 if (alc == NULL)
3754 return false;
3755 strncpy (alc, h->root.root.string, len - 1);
3756 alc[len - 1] = '\0';
3757 if (alc[len - 2] == ELF_VER_CHR)
3758 alc[len - 2] = '\0';
3760 h->verinfo.vertree = t;
3761 t->used = true;
3762 d = NULL;
3764 if (t->globals != NULL)
3766 for (d = t->globals; d != NULL; d = d->next)
3767 if ((*d->match) (d, alc))
3768 break;
3771 /* See if there is anything to force this symbol to
3772 local scope. */
3773 if (d == NULL && t->locals != NULL)
3775 for (d = t->locals; d != NULL; d = d->next)
3777 if ((*d->match) (d, alc))
3779 if (h->dynindx != -1
3780 && info->shared
3781 && ! sinfo->export_dynamic)
3783 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3784 (*bed->elf_backend_hide_symbol) (info, h);
3785 /* FIXME: The name of the symbol has
3786 already been recorded in the dynamic
3787 string table section. */
3790 break;
3795 bfd_release (sinfo->output_bfd, alc);
3796 break;
3800 /* If we are building an application, we need to create a
3801 version node for this version. */
3802 if (t == NULL && ! info->shared)
3804 struct bfd_elf_version_tree **pp;
3805 int version_index;
3807 /* If we aren't going to export this symbol, we don't need
3808 to worry about it. */
3809 if (h->dynindx == -1)
3810 return true;
3812 t = ((struct bfd_elf_version_tree *)
3813 bfd_alloc (sinfo->output_bfd, sizeof *t));
3814 if (t == NULL)
3816 sinfo->failed = true;
3817 return false;
3820 t->next = NULL;
3821 t->name = p;
3822 t->globals = NULL;
3823 t->locals = NULL;
3824 t->deps = NULL;
3825 t->name_indx = (unsigned int) -1;
3826 t->used = true;
3828 version_index = 1;
3829 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3830 ++version_index;
3831 t->vernum = version_index;
3833 *pp = t;
3835 h->verinfo.vertree = t;
3837 else if (t == NULL)
3839 /* We could not find the version for a symbol when
3840 generating a shared archive. Return an error. */
3841 (*_bfd_error_handler)
3842 (_("%s: undefined versioned symbol name %s"),
3843 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3844 bfd_set_error (bfd_error_bad_value);
3845 sinfo->failed = true;
3846 return false;
3849 if (hidden)
3850 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3853 /* If we don't have a version for this symbol, see if we can find
3854 something. */
3855 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3857 struct bfd_elf_version_tree *t;
3858 struct bfd_elf_version_tree *deflt;
3859 struct bfd_elf_version_expr *d;
3861 /* See if can find what version this symbol is in. If the
3862 symbol is supposed to be local, then don't actually register
3863 it. */
3864 deflt = NULL;
3865 for (t = sinfo->verdefs; t != NULL; t = t->next)
3867 if (t->globals != NULL)
3869 for (d = t->globals; d != NULL; d = d->next)
3871 if ((*d->match) (d, h->root.root.string))
3873 h->verinfo.vertree = t;
3874 break;
3878 if (d != NULL)
3879 break;
3882 if (t->locals != NULL)
3884 for (d = t->locals; d != NULL; d = d->next)
3886 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3887 deflt = t;
3888 else if ((*d->match) (d, h->root.root.string))
3890 h->verinfo.vertree = t;
3891 if (h->dynindx != -1
3892 && info->shared
3893 && ! sinfo->export_dynamic)
3895 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3896 (*bed->elf_backend_hide_symbol) (info, h);
3897 /* FIXME: The name of the symbol has already
3898 been recorded in the dynamic string table
3899 section. */
3901 break;
3905 if (d != NULL)
3906 break;
3910 if (deflt != NULL && h->verinfo.vertree == NULL)
3912 h->verinfo.vertree = deflt;
3913 if (h->dynindx != -1
3914 && info->shared
3915 && ! sinfo->export_dynamic)
3917 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3918 (*bed->elf_backend_hide_symbol) (info, h);
3919 /* FIXME: The name of the symbol has already been
3920 recorded in the dynamic string table section. */
3925 return true;
3928 /* Final phase of ELF linker. */
3930 /* A structure we use to avoid passing large numbers of arguments. */
3932 struct elf_final_link_info
3934 /* General link information. */
3935 struct bfd_link_info *info;
3936 /* Output BFD. */
3937 bfd *output_bfd;
3938 /* Symbol string table. */
3939 struct bfd_strtab_hash *symstrtab;
3940 /* .dynsym section. */
3941 asection *dynsym_sec;
3942 /* .hash section. */
3943 asection *hash_sec;
3944 /* symbol version section (.gnu.version). */
3945 asection *symver_sec;
3946 /* Buffer large enough to hold contents of any section. */
3947 bfd_byte *contents;
3948 /* Buffer large enough to hold external relocs of any section. */
3949 PTR external_relocs;
3950 /* Buffer large enough to hold internal relocs of any section. */
3951 Elf_Internal_Rela *internal_relocs;
3952 /* Buffer large enough to hold external local symbols of any input
3953 BFD. */
3954 Elf_External_Sym *external_syms;
3955 /* Buffer large enough to hold internal local symbols of any input
3956 BFD. */
3957 Elf_Internal_Sym *internal_syms;
3958 /* Array large enough to hold a symbol index for each local symbol
3959 of any input BFD. */
3960 long *indices;
3961 /* Array large enough to hold a section pointer for each local
3962 symbol of any input BFD. */
3963 asection **sections;
3964 /* Buffer to hold swapped out symbols. */
3965 Elf_External_Sym *symbuf;
3966 /* Number of swapped out symbols in buffer. */
3967 size_t symbuf_count;
3968 /* Number of symbols which fit in symbuf. */
3969 size_t symbuf_size;
3972 static boolean elf_link_output_sym
3973 PARAMS ((struct elf_final_link_info *, const char *,
3974 Elf_Internal_Sym *, asection *));
3975 static boolean elf_link_flush_output_syms
3976 PARAMS ((struct elf_final_link_info *));
3977 static boolean elf_link_output_extsym
3978 PARAMS ((struct elf_link_hash_entry *, PTR));
3979 static boolean elf_link_input_bfd
3980 PARAMS ((struct elf_final_link_info *, bfd *));
3981 static boolean elf_reloc_link_order
3982 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3983 struct bfd_link_order *));
3985 /* This struct is used to pass information to elf_link_output_extsym. */
3987 struct elf_outext_info
3989 boolean failed;
3990 boolean localsyms;
3991 struct elf_final_link_info *finfo;
3994 /* Compute the size of, and allocate space for, REL_HDR which is the
3995 section header for a section containing relocations for O. */
3997 static boolean
3998 elf_link_size_reloc_section (abfd, rel_hdr, o)
3999 bfd *abfd;
4000 Elf_Internal_Shdr *rel_hdr;
4001 asection *o;
4003 register struct elf_link_hash_entry **p, **pend;
4004 unsigned reloc_count;
4006 /* Figure out how many relocations there will be. */
4007 if (rel_hdr == &elf_section_data (o)->rel_hdr)
4008 reloc_count = elf_section_data (o)->rel_count;
4009 else
4010 reloc_count = elf_section_data (o)->rel_count2;
4012 /* That allows us to calculate the size of the section. */
4013 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
4015 /* The contents field must last into write_object_contents, so we
4016 allocate it with bfd_alloc rather than malloc. */
4017 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
4018 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
4019 return false;
4021 /* We only allocate one set of hash entries, so we only do it the
4022 first time we are called. */
4023 if (elf_section_data (o)->rel_hashes == NULL)
4025 p = ((struct elf_link_hash_entry **)
4026 bfd_malloc (o->reloc_count
4027 * sizeof (struct elf_link_hash_entry *)));
4028 if (p == NULL && o->reloc_count != 0)
4029 return false;
4031 elf_section_data (o)->rel_hashes = p;
4032 pend = p + o->reloc_count;
4033 for (; p < pend; p++)
4034 *p = NULL;
4037 return true;
4040 /* When performing a relocateable link, the input relocations are
4041 preserved. But, if they reference global symbols, the indices
4042 referenced must be updated. Update all the relocations in
4043 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
4045 static void
4046 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
4047 bfd *abfd;
4048 Elf_Internal_Shdr *rel_hdr;
4049 unsigned int count;
4050 struct elf_link_hash_entry **rel_hash;
4052 unsigned int i;
4053 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4055 for (i = 0; i < count; i++, rel_hash++)
4057 if (*rel_hash == NULL)
4058 continue;
4060 BFD_ASSERT ((*rel_hash)->indx >= 0);
4062 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4064 Elf_External_Rel *erel;
4065 Elf_Internal_Rel irel;
4067 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4068 if (bed->s->swap_reloc_in)
4069 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, &irel);
4070 else
4071 elf_swap_reloc_in (abfd, erel, &irel);
4072 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4073 ELF_R_TYPE (irel.r_info));
4074 if (bed->s->swap_reloc_out)
4075 (*bed->s->swap_reloc_out) (abfd, &irel, (bfd_byte *) erel);
4076 else
4077 elf_swap_reloc_out (abfd, &irel, erel);
4079 else
4081 Elf_External_Rela *erela;
4082 Elf_Internal_Rela irela;
4084 BFD_ASSERT (rel_hdr->sh_entsize
4085 == sizeof (Elf_External_Rela));
4087 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4088 if (bed->s->swap_reloca_in)
4089 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, &irela);
4090 else
4091 elf_swap_reloca_in (abfd, erela, &irela);
4092 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4093 ELF_R_TYPE (irela.r_info));
4094 if (bed->s->swap_reloca_out)
4095 (*bed->s->swap_reloca_out) (abfd, &irela, (bfd_byte *) erela);
4096 else
4097 elf_swap_reloca_out (abfd, &irela, erela);
4102 /* Do the final step of an ELF link. */
4104 boolean
4105 elf_bfd_final_link (abfd, info)
4106 bfd *abfd;
4107 struct bfd_link_info *info;
4109 boolean dynamic;
4110 bfd *dynobj;
4111 struct elf_final_link_info finfo;
4112 register asection *o;
4113 register struct bfd_link_order *p;
4114 register bfd *sub;
4115 size_t max_contents_size;
4116 size_t max_external_reloc_size;
4117 size_t max_internal_reloc_count;
4118 size_t max_sym_count;
4119 file_ptr off;
4120 Elf_Internal_Sym elfsym;
4121 unsigned int i;
4122 Elf_Internal_Shdr *symtab_hdr;
4123 Elf_Internal_Shdr *symstrtab_hdr;
4124 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4125 struct elf_outext_info eoinfo;
4127 if (info->shared)
4128 abfd->flags |= DYNAMIC;
4130 dynamic = elf_hash_table (info)->dynamic_sections_created;
4131 dynobj = elf_hash_table (info)->dynobj;
4133 finfo.info = info;
4134 finfo.output_bfd = abfd;
4135 finfo.symstrtab = elf_stringtab_init ();
4136 if (finfo.symstrtab == NULL)
4137 return false;
4139 if (! dynamic)
4141 finfo.dynsym_sec = NULL;
4142 finfo.hash_sec = NULL;
4143 finfo.symver_sec = NULL;
4145 else
4147 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4148 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4149 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4150 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4151 /* Note that it is OK if symver_sec is NULL. */
4154 finfo.contents = NULL;
4155 finfo.external_relocs = NULL;
4156 finfo.internal_relocs = NULL;
4157 finfo.external_syms = NULL;
4158 finfo.internal_syms = NULL;
4159 finfo.indices = NULL;
4160 finfo.sections = NULL;
4161 finfo.symbuf = NULL;
4162 finfo.symbuf_count = 0;
4164 /* Count up the number of relocations we will output for each output
4165 section, so that we know the sizes of the reloc sections. We
4166 also figure out some maximum sizes. */
4167 max_contents_size = 0;
4168 max_external_reloc_size = 0;
4169 max_internal_reloc_count = 0;
4170 max_sym_count = 0;
4171 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4173 o->reloc_count = 0;
4175 for (p = o->link_order_head; p != NULL; p = p->next)
4177 if (p->type == bfd_section_reloc_link_order
4178 || p->type == bfd_symbol_reloc_link_order)
4179 ++o->reloc_count;
4180 else if (p->type == bfd_indirect_link_order)
4182 asection *sec;
4184 sec = p->u.indirect.section;
4186 /* Mark all sections which are to be included in the
4187 link. This will normally be every section. We need
4188 to do this so that we can identify any sections which
4189 the linker has decided to not include. */
4190 sec->linker_mark = true;
4192 if (info->relocateable || info->emitrelocations)
4193 o->reloc_count += sec->reloc_count;
4195 if (sec->_raw_size > max_contents_size)
4196 max_contents_size = sec->_raw_size;
4197 if (sec->_cooked_size > max_contents_size)
4198 max_contents_size = sec->_cooked_size;
4200 /* We are interested in just local symbols, not all
4201 symbols. */
4202 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4203 && (sec->owner->flags & DYNAMIC) == 0)
4205 size_t sym_count;
4207 if (elf_bad_symtab (sec->owner))
4208 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4209 / sizeof (Elf_External_Sym));
4210 else
4211 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4213 if (sym_count > max_sym_count)
4214 max_sym_count = sym_count;
4216 if ((sec->flags & SEC_RELOC) != 0)
4218 size_t ext_size;
4220 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4221 if (ext_size > max_external_reloc_size)
4222 max_external_reloc_size = ext_size;
4223 if (sec->reloc_count > max_internal_reloc_count)
4224 max_internal_reloc_count = sec->reloc_count;
4230 if (o->reloc_count > 0)
4231 o->flags |= SEC_RELOC;
4232 else
4234 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4235 set it (this is probably a bug) and if it is set
4236 assign_section_numbers will create a reloc section. */
4237 o->flags &=~ SEC_RELOC;
4240 /* If the SEC_ALLOC flag is not set, force the section VMA to
4241 zero. This is done in elf_fake_sections as well, but forcing
4242 the VMA to 0 here will ensure that relocs against these
4243 sections are handled correctly. */
4244 if ((o->flags & SEC_ALLOC) == 0
4245 && ! o->user_set_vma)
4246 o->vma = 0;
4249 /* Figure out the file positions for everything but the symbol table
4250 and the relocs. We set symcount to force assign_section_numbers
4251 to create a symbol table. */
4252 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4253 BFD_ASSERT (! abfd->output_has_begun);
4254 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4255 goto error_return;
4257 /* Figure out how many relocations we will have in each section.
4258 Just using RELOC_COUNT isn't good enough since that doesn't
4259 maintain a separate value for REL vs. RELA relocations. */
4260 if (info->relocateable || info->emitrelocations)
4261 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4262 for (o = sub->sections; o != NULL; o = o->next)
4264 asection *output_section;
4266 if (! o->linker_mark)
4268 /* This section was omitted from the link. */
4269 continue;
4272 output_section = o->output_section;
4274 if (output_section != NULL
4275 && (o->flags & SEC_RELOC) != 0)
4277 struct bfd_elf_section_data *esdi
4278 = elf_section_data (o);
4279 struct bfd_elf_section_data *esdo
4280 = elf_section_data (output_section);
4281 unsigned int *rel_count;
4282 unsigned int *rel_count2;
4284 /* We must be careful to add the relocation froms the
4285 input section to the right output count. */
4286 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4288 rel_count = &esdo->rel_count;
4289 rel_count2 = &esdo->rel_count2;
4291 else
4293 rel_count = &esdo->rel_count2;
4294 rel_count2 = &esdo->rel_count;
4297 *rel_count += (esdi->rel_hdr.sh_size
4298 / esdi->rel_hdr.sh_entsize);
4299 if (esdi->rel_hdr2)
4300 *rel_count2 += (esdi->rel_hdr2->sh_size
4301 / esdi->rel_hdr2->sh_entsize);
4305 /* That created the reloc sections. Set their sizes, and assign
4306 them file positions, and allocate some buffers. */
4307 for (o = abfd->sections; o != NULL; o = o->next)
4309 if ((o->flags & SEC_RELOC) != 0)
4311 if (!elf_link_size_reloc_section (abfd,
4312 &elf_section_data (o)->rel_hdr,
4314 goto error_return;
4316 if (elf_section_data (o)->rel_hdr2
4317 && !elf_link_size_reloc_section (abfd,
4318 elf_section_data (o)->rel_hdr2,
4320 goto error_return;
4323 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4324 to count upwards while actually outputting the relocations. */
4325 elf_section_data (o)->rel_count = 0;
4326 elf_section_data (o)->rel_count2 = 0;
4329 _bfd_elf_assign_file_positions_for_relocs (abfd);
4331 /* We have now assigned file positions for all the sections except
4332 .symtab and .strtab. We start the .symtab section at the current
4333 file position, and write directly to it. We build the .strtab
4334 section in memory. */
4335 bfd_get_symcount (abfd) = 0;
4336 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4337 /* sh_name is set in prep_headers. */
4338 symtab_hdr->sh_type = SHT_SYMTAB;
4339 symtab_hdr->sh_flags = 0;
4340 symtab_hdr->sh_addr = 0;
4341 symtab_hdr->sh_size = 0;
4342 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4343 /* sh_link is set in assign_section_numbers. */
4344 /* sh_info is set below. */
4345 /* sh_offset is set just below. */
4346 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4348 off = elf_tdata (abfd)->next_file_pos;
4349 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4351 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4352 incorrect. We do not yet know the size of the .symtab section.
4353 We correct next_file_pos below, after we do know the size. */
4355 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4356 continuously seeking to the right position in the file. */
4357 if (! info->keep_memory || max_sym_count < 20)
4358 finfo.symbuf_size = 20;
4359 else
4360 finfo.symbuf_size = max_sym_count;
4361 finfo.symbuf = ((Elf_External_Sym *)
4362 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4363 if (finfo.symbuf == NULL)
4364 goto error_return;
4366 /* Start writing out the symbol table. The first symbol is always a
4367 dummy symbol. */
4368 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4370 elfsym.st_value = 0;
4371 elfsym.st_size = 0;
4372 elfsym.st_info = 0;
4373 elfsym.st_other = 0;
4374 elfsym.st_shndx = SHN_UNDEF;
4375 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4376 &elfsym, bfd_und_section_ptr))
4377 goto error_return;
4380 #if 0
4381 /* Some standard ELF linkers do this, but we don't because it causes
4382 bootstrap comparison failures. */
4383 /* Output a file symbol for the output file as the second symbol.
4384 We output this even if we are discarding local symbols, although
4385 I'm not sure if this is correct. */
4386 elfsym.st_value = 0;
4387 elfsym.st_size = 0;
4388 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4389 elfsym.st_other = 0;
4390 elfsym.st_shndx = SHN_ABS;
4391 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4392 &elfsym, bfd_abs_section_ptr))
4393 goto error_return;
4394 #endif
4396 /* Output a symbol for each section. We output these even if we are
4397 discarding local symbols, since they are used for relocs. These
4398 symbols have no names. We store the index of each one in the
4399 index field of the section, so that we can find it again when
4400 outputting relocs. */
4401 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4403 elfsym.st_size = 0;
4404 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4405 elfsym.st_other = 0;
4406 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4408 o = section_from_elf_index (abfd, i);
4409 if (o != NULL)
4410 o->target_index = bfd_get_symcount (abfd);
4411 elfsym.st_shndx = i;
4412 if (info->relocateable || o == NULL)
4413 elfsym.st_value = 0;
4414 else
4415 elfsym.st_value = o->vma;
4416 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4417 &elfsym, o))
4418 goto error_return;
4422 /* Allocate some memory to hold information read in from the input
4423 files. */
4424 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4425 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4426 finfo.internal_relocs = ((Elf_Internal_Rela *)
4427 bfd_malloc (max_internal_reloc_count
4428 * sizeof (Elf_Internal_Rela)
4429 * bed->s->int_rels_per_ext_rel));
4430 finfo.external_syms = ((Elf_External_Sym *)
4431 bfd_malloc (max_sym_count
4432 * sizeof (Elf_External_Sym)));
4433 finfo.internal_syms = ((Elf_Internal_Sym *)
4434 bfd_malloc (max_sym_count
4435 * sizeof (Elf_Internal_Sym)));
4436 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4437 finfo.sections = ((asection **)
4438 bfd_malloc (max_sym_count * sizeof (asection *)));
4439 if ((finfo.contents == NULL && max_contents_size != 0)
4440 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4441 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4442 || (finfo.external_syms == NULL && max_sym_count != 0)
4443 || (finfo.internal_syms == NULL && max_sym_count != 0)
4444 || (finfo.indices == NULL && max_sym_count != 0)
4445 || (finfo.sections == NULL && max_sym_count != 0))
4446 goto error_return;
4448 /* Since ELF permits relocations to be against local symbols, we
4449 must have the local symbols available when we do the relocations.
4450 Since we would rather only read the local symbols once, and we
4451 would rather not keep them in memory, we handle all the
4452 relocations for a single input file at the same time.
4454 Unfortunately, there is no way to know the total number of local
4455 symbols until we have seen all of them, and the local symbol
4456 indices precede the global symbol indices. This means that when
4457 we are generating relocateable output, and we see a reloc against
4458 a global symbol, we can not know the symbol index until we have
4459 finished examining all the local symbols to see which ones we are
4460 going to output. To deal with this, we keep the relocations in
4461 memory, and don't output them until the end of the link. This is
4462 an unfortunate waste of memory, but I don't see a good way around
4463 it. Fortunately, it only happens when performing a relocateable
4464 link, which is not the common case. FIXME: If keep_memory is set
4465 we could write the relocs out and then read them again; I don't
4466 know how bad the memory loss will be. */
4468 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4469 sub->output_has_begun = false;
4470 for (o = abfd->sections; o != NULL; o = o->next)
4472 for (p = o->link_order_head; p != NULL; p = p->next)
4474 if (p->type == bfd_indirect_link_order
4475 && (bfd_get_flavour (p->u.indirect.section->owner)
4476 == bfd_target_elf_flavour))
4478 sub = p->u.indirect.section->owner;
4479 if (! sub->output_has_begun)
4481 if (! elf_link_input_bfd (&finfo, sub))
4482 goto error_return;
4483 sub->output_has_begun = true;
4486 else if (p->type == bfd_section_reloc_link_order
4487 || p->type == bfd_symbol_reloc_link_order)
4489 if (! elf_reloc_link_order (abfd, info, o, p))
4490 goto error_return;
4492 else
4494 if (! _bfd_default_link_order (abfd, info, o, p))
4495 goto error_return;
4500 /* That wrote out all the local symbols. Finish up the symbol table
4501 with the global symbols. Even if we want to strip everything we
4502 can, we still need to deal with those global symbols that got
4503 converted to local in a version script. */
4505 if (info->shared)
4507 /* Output any global symbols that got converted to local in a
4508 version script. We do this in a separate step since ELF
4509 requires all local symbols to appear prior to any global
4510 symbols. FIXME: We should only do this if some global
4511 symbols were, in fact, converted to become local. FIXME:
4512 Will this work correctly with the Irix 5 linker? */
4513 eoinfo.failed = false;
4514 eoinfo.finfo = &finfo;
4515 eoinfo.localsyms = true;
4516 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4517 (PTR) &eoinfo);
4518 if (eoinfo.failed)
4519 return false;
4522 /* The sh_info field records the index of the first non local symbol. */
4523 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4525 if (dynamic)
4527 Elf_Internal_Sym sym;
4528 Elf_External_Sym *dynsym =
4529 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4530 long last_local = 0;
4532 /* Write out the section symbols for the output sections. */
4533 if (info->shared)
4535 asection *s;
4537 sym.st_size = 0;
4538 sym.st_name = 0;
4539 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4540 sym.st_other = 0;
4542 for (s = abfd->sections; s != NULL; s = s->next)
4544 int indx;
4545 indx = elf_section_data (s)->this_idx;
4546 BFD_ASSERT (indx > 0);
4547 sym.st_shndx = indx;
4548 sym.st_value = s->vma;
4550 elf_swap_symbol_out (abfd, &sym,
4551 dynsym + elf_section_data (s)->dynindx);
4554 last_local = bfd_count_sections (abfd);
4557 /* Write out the local dynsyms. */
4558 if (elf_hash_table (info)->dynlocal)
4560 struct elf_link_local_dynamic_entry *e;
4561 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4563 asection *s;
4565 sym.st_size = e->isym.st_size;
4566 sym.st_other = e->isym.st_other;
4568 /* Copy the internal symbol as is.
4569 Note that we saved a word of storage and overwrote
4570 the original st_name with the dynstr_index. */
4571 sym = e->isym;
4573 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4575 s = bfd_section_from_elf_index (e->input_bfd,
4576 e->isym.st_shndx);
4578 sym.st_shndx =
4579 elf_section_data (s->output_section)->this_idx;
4580 sym.st_value = (s->output_section->vma
4581 + s->output_offset
4582 + e->isym.st_value);
4585 if (last_local < e->dynindx)
4586 last_local = e->dynindx;
4588 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4592 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4593 last_local + 1;
4596 /* We get the global symbols from the hash table. */
4597 eoinfo.failed = false;
4598 eoinfo.localsyms = false;
4599 eoinfo.finfo = &finfo;
4600 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4601 (PTR) &eoinfo);
4602 if (eoinfo.failed)
4603 return false;
4605 /* If backend needs to output some symbols not present in the hash
4606 table, do it now. */
4607 if (bed->elf_backend_output_arch_syms)
4609 if (! (*bed->elf_backend_output_arch_syms)
4610 (abfd, info, (PTR) &finfo,
4611 (boolean (*) PARAMS ((PTR, const char *,
4612 Elf_Internal_Sym *, asection *)))
4613 elf_link_output_sym))
4614 return false;
4617 /* Flush all symbols to the file. */
4618 if (! elf_link_flush_output_syms (&finfo))
4619 return false;
4621 /* Now we know the size of the symtab section. */
4622 off += symtab_hdr->sh_size;
4624 /* Finish up and write out the symbol string table (.strtab)
4625 section. */
4626 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4627 /* sh_name was set in prep_headers. */
4628 symstrtab_hdr->sh_type = SHT_STRTAB;
4629 symstrtab_hdr->sh_flags = 0;
4630 symstrtab_hdr->sh_addr = 0;
4631 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4632 symstrtab_hdr->sh_entsize = 0;
4633 symstrtab_hdr->sh_link = 0;
4634 symstrtab_hdr->sh_info = 0;
4635 /* sh_offset is set just below. */
4636 symstrtab_hdr->sh_addralign = 1;
4638 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4639 elf_tdata (abfd)->next_file_pos = off;
4641 if (bfd_get_symcount (abfd) > 0)
4643 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4644 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4645 return false;
4648 /* Adjust the relocs to have the correct symbol indices. */
4649 for (o = abfd->sections; o != NULL; o = o->next)
4651 if ((o->flags & SEC_RELOC) == 0)
4652 continue;
4654 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4655 elf_section_data (o)->rel_count,
4656 elf_section_data (o)->rel_hashes);
4657 if (elf_section_data (o)->rel_hdr2 != NULL)
4658 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4659 elf_section_data (o)->rel_count2,
4660 (elf_section_data (o)->rel_hashes
4661 + elf_section_data (o)->rel_count));
4663 /* Set the reloc_count field to 0 to prevent write_relocs from
4664 trying to swap the relocs out itself. */
4665 o->reloc_count = 0;
4668 /* If we are linking against a dynamic object, or generating a
4669 shared library, finish up the dynamic linking information. */
4670 if (dynamic)
4672 Elf_External_Dyn *dyncon, *dynconend;
4674 /* Fix up .dynamic entries. */
4675 o = bfd_get_section_by_name (dynobj, ".dynamic");
4676 BFD_ASSERT (o != NULL);
4678 dyncon = (Elf_External_Dyn *) o->contents;
4679 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4680 for (; dyncon < dynconend; dyncon++)
4682 Elf_Internal_Dyn dyn;
4683 const char *name;
4684 unsigned int type;
4686 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4688 switch (dyn.d_tag)
4690 default:
4691 break;
4692 case DT_INIT:
4693 name = info->init_function;
4694 goto get_sym;
4695 case DT_FINI:
4696 name = info->fini_function;
4697 get_sym:
4699 struct elf_link_hash_entry *h;
4701 h = elf_link_hash_lookup (elf_hash_table (info), name,
4702 false, false, true);
4703 if (h != NULL
4704 && (h->root.type == bfd_link_hash_defined
4705 || h->root.type == bfd_link_hash_defweak))
4707 dyn.d_un.d_val = h->root.u.def.value;
4708 o = h->root.u.def.section;
4709 if (o->output_section != NULL)
4710 dyn.d_un.d_val += (o->output_section->vma
4711 + o->output_offset);
4712 else
4714 /* The symbol is imported from another shared
4715 library and does not apply to this one. */
4716 dyn.d_un.d_val = 0;
4719 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4722 break;
4724 case DT_HASH:
4725 name = ".hash";
4726 goto get_vma;
4727 case DT_STRTAB:
4728 name = ".dynstr";
4729 goto get_vma;
4730 case DT_SYMTAB:
4731 name = ".dynsym";
4732 goto get_vma;
4733 case DT_VERDEF:
4734 name = ".gnu.version_d";
4735 goto get_vma;
4736 case DT_VERNEED:
4737 name = ".gnu.version_r";
4738 goto get_vma;
4739 case DT_VERSYM:
4740 name = ".gnu.version";
4741 get_vma:
4742 o = bfd_get_section_by_name (abfd, name);
4743 BFD_ASSERT (o != NULL);
4744 dyn.d_un.d_ptr = o->vma;
4745 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4746 break;
4748 case DT_REL:
4749 case DT_RELA:
4750 case DT_RELSZ:
4751 case DT_RELASZ:
4752 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4753 type = SHT_REL;
4754 else
4755 type = SHT_RELA;
4756 dyn.d_un.d_val = 0;
4757 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4759 Elf_Internal_Shdr *hdr;
4761 hdr = elf_elfsections (abfd)[i];
4762 if (hdr->sh_type == type
4763 && (hdr->sh_flags & SHF_ALLOC) != 0)
4765 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4766 dyn.d_un.d_val += hdr->sh_size;
4767 else
4769 if (dyn.d_un.d_val == 0
4770 || hdr->sh_addr < dyn.d_un.d_val)
4771 dyn.d_un.d_val = hdr->sh_addr;
4775 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4776 break;
4781 /* If we have created any dynamic sections, then output them. */
4782 if (dynobj != NULL)
4784 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4785 goto error_return;
4787 for (o = dynobj->sections; o != NULL; o = o->next)
4789 if ((o->flags & SEC_HAS_CONTENTS) == 0
4790 || o->_raw_size == 0)
4791 continue;
4792 if ((o->flags & SEC_LINKER_CREATED) == 0)
4794 /* At this point, we are only interested in sections
4795 created by elf_link_create_dynamic_sections. */
4796 continue;
4798 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4799 != SHT_STRTAB)
4800 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4802 if (! bfd_set_section_contents (abfd, o->output_section,
4803 o->contents, o->output_offset,
4804 o->_raw_size))
4805 goto error_return;
4807 else
4809 file_ptr off;
4811 /* The contents of the .dynstr section are actually in a
4812 stringtab. */
4813 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4814 if (bfd_seek (abfd, off, SEEK_SET) != 0
4815 || ! _bfd_stringtab_emit (abfd,
4816 elf_hash_table (info)->dynstr))
4817 goto error_return;
4822 /* If we have optimized stabs strings, output them. */
4823 if (elf_hash_table (info)->stab_info != NULL)
4825 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4826 goto error_return;
4829 if (finfo.symstrtab != NULL)
4830 _bfd_stringtab_free (finfo.symstrtab);
4831 if (finfo.contents != NULL)
4832 free (finfo.contents);
4833 if (finfo.external_relocs != NULL)
4834 free (finfo.external_relocs);
4835 if (finfo.internal_relocs != NULL)
4836 free (finfo.internal_relocs);
4837 if (finfo.external_syms != NULL)
4838 free (finfo.external_syms);
4839 if (finfo.internal_syms != NULL)
4840 free (finfo.internal_syms);
4841 if (finfo.indices != NULL)
4842 free (finfo.indices);
4843 if (finfo.sections != NULL)
4844 free (finfo.sections);
4845 if (finfo.symbuf != NULL)
4846 free (finfo.symbuf);
4847 for (o = abfd->sections; o != NULL; o = o->next)
4849 if ((o->flags & SEC_RELOC) != 0
4850 && elf_section_data (o)->rel_hashes != NULL)
4851 free (elf_section_data (o)->rel_hashes);
4854 elf_tdata (abfd)->linker = true;
4856 return true;
4858 error_return:
4859 if (finfo.symstrtab != NULL)
4860 _bfd_stringtab_free (finfo.symstrtab);
4861 if (finfo.contents != NULL)
4862 free (finfo.contents);
4863 if (finfo.external_relocs != NULL)
4864 free (finfo.external_relocs);
4865 if (finfo.internal_relocs != NULL)
4866 free (finfo.internal_relocs);
4867 if (finfo.external_syms != NULL)
4868 free (finfo.external_syms);
4869 if (finfo.internal_syms != NULL)
4870 free (finfo.internal_syms);
4871 if (finfo.indices != NULL)
4872 free (finfo.indices);
4873 if (finfo.sections != NULL)
4874 free (finfo.sections);
4875 if (finfo.symbuf != NULL)
4876 free (finfo.symbuf);
4877 for (o = abfd->sections; o != NULL; o = o->next)
4879 if ((o->flags & SEC_RELOC) != 0
4880 && elf_section_data (o)->rel_hashes != NULL)
4881 free (elf_section_data (o)->rel_hashes);
4884 return false;
4887 /* Add a symbol to the output symbol table. */
4889 static boolean
4890 elf_link_output_sym (finfo, name, elfsym, input_sec)
4891 struct elf_final_link_info *finfo;
4892 const char *name;
4893 Elf_Internal_Sym *elfsym;
4894 asection *input_sec;
4896 boolean (*output_symbol_hook) PARAMS ((bfd *,
4897 struct bfd_link_info *info,
4898 const char *,
4899 Elf_Internal_Sym *,
4900 asection *));
4902 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4903 elf_backend_link_output_symbol_hook;
4904 if (output_symbol_hook != NULL)
4906 if (! ((*output_symbol_hook)
4907 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4908 return false;
4911 if (name == (const char *) NULL || *name == '\0')
4912 elfsym->st_name = 0;
4913 else if (input_sec->flags & SEC_EXCLUDE)
4914 elfsym->st_name = 0;
4915 else
4917 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4918 name, true,
4919 false);
4920 if (elfsym->st_name == (unsigned long) -1)
4921 return false;
4924 if (finfo->symbuf_count >= finfo->symbuf_size)
4926 if (! elf_link_flush_output_syms (finfo))
4927 return false;
4930 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4931 (PTR) (finfo->symbuf + finfo->symbuf_count));
4932 ++finfo->symbuf_count;
4934 ++ bfd_get_symcount (finfo->output_bfd);
4936 return true;
4939 /* Flush the output symbols to the file. */
4941 static boolean
4942 elf_link_flush_output_syms (finfo)
4943 struct elf_final_link_info *finfo;
4945 if (finfo->symbuf_count > 0)
4947 Elf_Internal_Shdr *symtab;
4949 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4951 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4952 SEEK_SET) != 0
4953 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4954 sizeof (Elf_External_Sym), finfo->output_bfd)
4955 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4956 return false;
4958 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4960 finfo->symbuf_count = 0;
4963 return true;
4966 /* Add an external symbol to the symbol table. This is called from
4967 the hash table traversal routine. When generating a shared object,
4968 we go through the symbol table twice. The first time we output
4969 anything that might have been forced to local scope in a version
4970 script. The second time we output the symbols that are still
4971 global symbols. */
4973 static boolean
4974 elf_link_output_extsym (h, data)
4975 struct elf_link_hash_entry *h;
4976 PTR data;
4978 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4979 struct elf_final_link_info *finfo = eoinfo->finfo;
4980 boolean strip;
4981 Elf_Internal_Sym sym;
4982 asection *input_sec;
4984 /* Decide whether to output this symbol in this pass. */
4985 if (eoinfo->localsyms)
4987 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4988 return true;
4990 else
4992 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4993 return true;
4996 /* If we are not creating a shared library, and this symbol is
4997 referenced by a shared library but is not defined anywhere, then
4998 warn that it is undefined. If we do not do this, the runtime
4999 linker will complain that the symbol is undefined when the
5000 program is run. We don't have to worry about symbols that are
5001 referenced by regular files, because we will already have issued
5002 warnings for them. */
5003 if (! finfo->info->relocateable
5004 && ! (finfo->info->shared
5005 && !finfo->info->no_undefined)
5006 && h->root.type == bfd_link_hash_undefined
5007 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
5008 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5010 if (! ((*finfo->info->callbacks->undefined_symbol)
5011 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
5012 (asection *) NULL, 0, true)))
5014 eoinfo->failed = true;
5015 return false;
5019 /* We don't want to output symbols that have never been mentioned by
5020 a regular file, or that we have been told to strip. However, if
5021 h->indx is set to -2, the symbol is used by a reloc and we must
5022 output it. */
5023 if (h->indx == -2)
5024 strip = false;
5025 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
5026 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
5027 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
5028 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5029 strip = true;
5030 else if (finfo->info->strip == strip_all
5031 || (finfo->info->strip == strip_some
5032 && bfd_hash_lookup (finfo->info->keep_hash,
5033 h->root.root.string,
5034 false, false) == NULL))
5035 strip = true;
5036 else
5037 strip = false;
5039 /* If we're stripping it, and it's not a dynamic symbol, there's
5040 nothing else to do unless it is a forced local symbol. */
5041 if (strip
5042 && h->dynindx == -1
5043 && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5044 return true;
5046 sym.st_value = 0;
5047 sym.st_size = h->size;
5048 sym.st_other = h->other;
5049 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5050 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
5051 else if (h->root.type == bfd_link_hash_undefweak
5052 || h->root.type == bfd_link_hash_defweak)
5053 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
5054 else
5055 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
5057 switch (h->root.type)
5059 default:
5060 case bfd_link_hash_new:
5061 abort ();
5062 return false;
5064 case bfd_link_hash_undefined:
5065 input_sec = bfd_und_section_ptr;
5066 sym.st_shndx = SHN_UNDEF;
5067 break;
5069 case bfd_link_hash_undefweak:
5070 input_sec = bfd_und_section_ptr;
5071 sym.st_shndx = SHN_UNDEF;
5072 break;
5074 case bfd_link_hash_defined:
5075 case bfd_link_hash_defweak:
5077 input_sec = h->root.u.def.section;
5078 if (input_sec->output_section != NULL)
5080 sym.st_shndx =
5081 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
5082 input_sec->output_section);
5083 if (sym.st_shndx == (unsigned short) -1)
5085 (*_bfd_error_handler)
5086 (_("%s: could not find output section %s for input section %s"),
5087 bfd_get_filename (finfo->output_bfd),
5088 input_sec->output_section->name,
5089 input_sec->name);
5090 eoinfo->failed = true;
5091 return false;
5094 /* ELF symbols in relocateable files are section relative,
5095 but in nonrelocateable files they are virtual
5096 addresses. */
5097 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5098 if (! finfo->info->relocateable)
5099 sym.st_value += input_sec->output_section->vma;
5101 else
5103 BFD_ASSERT (input_sec->owner == NULL
5104 || (input_sec->owner->flags & DYNAMIC) != 0);
5105 sym.st_shndx = SHN_UNDEF;
5106 input_sec = bfd_und_section_ptr;
5109 break;
5111 case bfd_link_hash_common:
5112 input_sec = h->root.u.c.p->section;
5113 sym.st_shndx = SHN_COMMON;
5114 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5115 break;
5117 case bfd_link_hash_indirect:
5118 /* These symbols are created by symbol versioning. They point
5119 to the decorated version of the name. For example, if the
5120 symbol foo@@GNU_1.2 is the default, which should be used when
5121 foo is used with no version, then we add an indirect symbol
5122 foo which points to foo@@GNU_1.2. We ignore these symbols,
5123 since the indirected symbol is already in the hash table. */
5124 return true;
5126 case bfd_link_hash_warning:
5127 /* We can't represent these symbols in ELF, although a warning
5128 symbol may have come from a .gnu.warning.SYMBOL section. We
5129 just put the target symbol in the hash table. If the target
5130 symbol does not really exist, don't do anything. */
5131 if (h->root.u.i.link->type == bfd_link_hash_new)
5132 return true;
5133 return (elf_link_output_extsym
5134 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5137 /* Give the processor backend a chance to tweak the symbol value,
5138 and also to finish up anything that needs to be done for this
5139 symbol. */
5140 if ((h->dynindx != -1
5141 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5142 && elf_hash_table (finfo->info)->dynamic_sections_created)
5144 struct elf_backend_data *bed;
5146 bed = get_elf_backend_data (finfo->output_bfd);
5147 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5148 (finfo->output_bfd, finfo->info, h, &sym)))
5150 eoinfo->failed = true;
5151 return false;
5155 /* If we are marking the symbol as undefined, and there are no
5156 non-weak references to this symbol from a regular object, then
5157 mark the symbol as weak undefined; if there are non-weak
5158 references, mark the symbol as strong. We can't do this earlier,
5159 because it might not be marked as undefined until the
5160 finish_dynamic_symbol routine gets through with it. */
5161 if (sym.st_shndx == SHN_UNDEF
5162 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5163 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5164 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5166 int bindtype;
5168 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5169 bindtype = STB_GLOBAL;
5170 else
5171 bindtype = STB_WEAK;
5172 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5175 /* If a symbol is not defined locally, we clear the visibility
5176 field. */
5177 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5178 sym.st_other ^= ELF_ST_VISIBILITY(sym.st_other);
5180 /* If this symbol should be put in the .dynsym section, then put it
5181 there now. We have already know the symbol index. We also fill
5182 in the entry in the .hash section. */
5183 if (h->dynindx != -1
5184 && elf_hash_table (finfo->info)->dynamic_sections_created)
5186 size_t bucketcount;
5187 size_t bucket;
5188 size_t hash_entry_size;
5189 bfd_byte *bucketpos;
5190 bfd_vma chain;
5192 sym.st_name = h->dynstr_index;
5194 elf_swap_symbol_out (finfo->output_bfd, &sym,
5195 (PTR) (((Elf_External_Sym *)
5196 finfo->dynsym_sec->contents)
5197 + h->dynindx));
5199 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5200 bucket = h->elf_hash_value % bucketcount;
5201 hash_entry_size
5202 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5203 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5204 + (bucket + 2) * hash_entry_size);
5205 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5206 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5207 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5208 ((bfd_byte *) finfo->hash_sec->contents
5209 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5211 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5213 Elf_Internal_Versym iversym;
5215 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5217 if (h->verinfo.verdef == NULL)
5218 iversym.vs_vers = 0;
5219 else
5220 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5222 else
5224 if (h->verinfo.vertree == NULL)
5225 iversym.vs_vers = 1;
5226 else
5227 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5230 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5231 iversym.vs_vers |= VERSYM_HIDDEN;
5233 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5234 (((Elf_External_Versym *)
5235 finfo->symver_sec->contents)
5236 + h->dynindx));
5240 /* If we're stripping it, then it was just a dynamic symbol, and
5241 there's nothing else to do. */
5242 if (strip)
5243 return true;
5245 h->indx = bfd_get_symcount (finfo->output_bfd);
5247 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5249 eoinfo->failed = true;
5250 return false;
5253 return true;
5256 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5257 originated from the section given by INPUT_REL_HDR) to the
5258 OUTPUT_BFD. */
5260 static void
5261 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5262 internal_relocs)
5263 bfd *output_bfd;
5264 asection *input_section;
5265 Elf_Internal_Shdr *input_rel_hdr;
5266 Elf_Internal_Rela *internal_relocs;
5268 Elf_Internal_Rela *irela;
5269 Elf_Internal_Rela *irelaend;
5270 Elf_Internal_Shdr *output_rel_hdr;
5271 asection *output_section;
5272 unsigned int *rel_countp = NULL;
5273 struct elf_backend_data *bed;
5275 output_section = input_section->output_section;
5276 output_rel_hdr = NULL;
5278 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5279 == input_rel_hdr->sh_entsize)
5281 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5282 rel_countp = &elf_section_data (output_section)->rel_count;
5284 else if (elf_section_data (output_section)->rel_hdr2
5285 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5286 == input_rel_hdr->sh_entsize))
5288 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5289 rel_countp = &elf_section_data (output_section)->rel_count2;
5292 BFD_ASSERT (output_rel_hdr != NULL);
5294 bed = get_elf_backend_data (output_bfd);
5295 irela = internal_relocs;
5296 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5297 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5299 Elf_External_Rel *erel;
5301 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5302 for (; irela < irelaend; irela++, erel++)
5304 Elf_Internal_Rel irel;
5306 irel.r_offset = irela->r_offset;
5307 irel.r_info = irela->r_info;
5308 BFD_ASSERT (irela->r_addend == 0);
5309 if (bed->s->swap_reloc_out)
5310 (*bed->s->swap_reloc_out) (output_bfd, &irel, (PTR) erel);
5311 else
5312 elf_swap_reloc_out (output_bfd, &irel, erel);
5315 else
5317 Elf_External_Rela *erela;
5319 BFD_ASSERT (input_rel_hdr->sh_entsize
5320 == sizeof (Elf_External_Rela));
5321 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5322 for (; irela < irelaend; irela++, erela++)
5323 if (bed->s->swap_reloca_out)
5324 (*bed->s->swap_reloca_out) (output_bfd, irela, (PTR) erela);
5325 else
5326 elf_swap_reloca_out (output_bfd, irela, erela);
5329 /* Bump the counter, so that we know where to add the next set of
5330 relocations. */
5331 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5334 /* Link an input file into the linker output file. This function
5335 handles all the sections and relocations of the input file at once.
5336 This is so that we only have to read the local symbols once, and
5337 don't have to keep them in memory. */
5339 static boolean
5340 elf_link_input_bfd (finfo, input_bfd)
5341 struct elf_final_link_info *finfo;
5342 bfd *input_bfd;
5344 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5345 bfd *, asection *, bfd_byte *,
5346 Elf_Internal_Rela *,
5347 Elf_Internal_Sym *, asection **));
5348 bfd *output_bfd;
5349 Elf_Internal_Shdr *symtab_hdr;
5350 size_t locsymcount;
5351 size_t extsymoff;
5352 Elf_External_Sym *external_syms;
5353 Elf_External_Sym *esym;
5354 Elf_External_Sym *esymend;
5355 Elf_Internal_Sym *isym;
5356 long *pindex;
5357 asection **ppsection;
5358 asection *o;
5359 struct elf_backend_data *bed;
5361 output_bfd = finfo->output_bfd;
5362 bed = get_elf_backend_data (output_bfd);
5363 relocate_section = bed->elf_backend_relocate_section;
5365 /* If this is a dynamic object, we don't want to do anything here:
5366 we don't want the local symbols, and we don't want the section
5367 contents. */
5368 if ((input_bfd->flags & DYNAMIC) != 0)
5369 return true;
5371 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5372 if (elf_bad_symtab (input_bfd))
5374 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5375 extsymoff = 0;
5377 else
5379 locsymcount = symtab_hdr->sh_info;
5380 extsymoff = symtab_hdr->sh_info;
5383 /* Read the local symbols. */
5384 if (symtab_hdr->contents != NULL)
5385 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5386 else if (locsymcount == 0)
5387 external_syms = NULL;
5388 else
5390 external_syms = finfo->external_syms;
5391 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5392 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5393 locsymcount, input_bfd)
5394 != locsymcount * sizeof (Elf_External_Sym)))
5395 return false;
5398 /* Swap in the local symbols and write out the ones which we know
5399 are going into the output file. */
5400 esym = external_syms;
5401 esymend = esym + locsymcount;
5402 isym = finfo->internal_syms;
5403 pindex = finfo->indices;
5404 ppsection = finfo->sections;
5405 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5407 asection *isec;
5408 const char *name;
5409 Elf_Internal_Sym osym;
5411 elf_swap_symbol_in (input_bfd, esym, isym);
5412 *pindex = -1;
5414 if (elf_bad_symtab (input_bfd))
5416 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5418 *ppsection = NULL;
5419 continue;
5423 if (isym->st_shndx == SHN_UNDEF)
5424 isec = bfd_und_section_ptr;
5425 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5426 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5427 else if (isym->st_shndx == SHN_ABS)
5428 isec = bfd_abs_section_ptr;
5429 else if (isym->st_shndx == SHN_COMMON)
5430 isec = bfd_com_section_ptr;
5431 else
5433 /* Who knows? */
5434 isec = NULL;
5437 *ppsection = isec;
5439 /* Don't output the first, undefined, symbol. */
5440 if (esym == external_syms)
5441 continue;
5443 /* If we are stripping all symbols, we don't want to output this
5444 one. */
5445 if (finfo->info->strip == strip_all)
5446 continue;
5448 /* We never output section symbols. Instead, we use the section
5449 symbol of the corresponding section in the output file. */
5450 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5451 continue;
5453 /* If we are discarding all local symbols, we don't want to
5454 output this one. If we are generating a relocateable output
5455 file, then some of the local symbols may be required by
5456 relocs; we output them below as we discover that they are
5457 needed. */
5458 if (finfo->info->discard == discard_all)
5459 continue;
5461 /* If this symbol is defined in a section which we are
5462 discarding, we don't need to keep it, but note that
5463 linker_mark is only reliable for sections that have contents.
5464 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5465 as well as linker_mark. */
5466 if (isym->st_shndx > 0
5467 && isym->st_shndx < SHN_LORESERVE
5468 && isec != NULL
5469 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5470 || (! finfo->info->relocateable
5471 && (isec->flags & SEC_EXCLUDE) != 0)))
5472 continue;
5474 /* Get the name of the symbol. */
5475 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5476 isym->st_name);
5477 if (name == NULL)
5478 return false;
5480 /* See if we are discarding symbols with this name. */
5481 if ((finfo->info->strip == strip_some
5482 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5483 == NULL))
5484 || (finfo->info->discard == discard_l
5485 && bfd_is_local_label_name (input_bfd, name)))
5486 continue;
5488 /* If we get here, we are going to output this symbol. */
5490 osym = *isym;
5492 /* Adjust the section index for the output file. */
5493 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5494 isec->output_section);
5495 if (osym.st_shndx == (unsigned short) -1)
5496 return false;
5498 *pindex = bfd_get_symcount (output_bfd);
5500 /* ELF symbols in relocateable files are section relative, but
5501 in executable files they are virtual addresses. Note that
5502 this code assumes that all ELF sections have an associated
5503 BFD section with a reasonable value for output_offset; below
5504 we assume that they also have a reasonable value for
5505 output_section. Any special sections must be set up to meet
5506 these requirements. */
5507 osym.st_value += isec->output_offset;
5508 if (! finfo->info->relocateable)
5509 osym.st_value += isec->output_section->vma;
5511 if (! elf_link_output_sym (finfo, name, &osym, isec))
5512 return false;
5515 /* Relocate the contents of each section. */
5516 for (o = input_bfd->sections; o != NULL; o = o->next)
5518 bfd_byte *contents;
5520 if (! o->linker_mark)
5522 /* This section was omitted from the link. */
5523 continue;
5526 if ((o->flags & SEC_HAS_CONTENTS) == 0
5527 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5528 continue;
5530 if ((o->flags & SEC_LINKER_CREATED) != 0)
5532 /* Section was created by elf_link_create_dynamic_sections
5533 or somesuch. */
5534 continue;
5537 /* Get the contents of the section. They have been cached by a
5538 relaxation routine. Note that o is a section in an input
5539 file, so the contents field will not have been set by any of
5540 the routines which work on output files. */
5541 if (elf_section_data (o)->this_hdr.contents != NULL)
5542 contents = elf_section_data (o)->this_hdr.contents;
5543 else
5545 contents = finfo->contents;
5546 if (! bfd_get_section_contents (input_bfd, o, contents,
5547 (file_ptr) 0, o->_raw_size))
5548 return false;
5551 if ((o->flags & SEC_RELOC) != 0)
5553 Elf_Internal_Rela *internal_relocs;
5555 /* Get the swapped relocs. */
5556 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5557 (input_bfd, o, finfo->external_relocs,
5558 finfo->internal_relocs, false));
5559 if (internal_relocs == NULL
5560 && o->reloc_count > 0)
5561 return false;
5563 /* Relocate the section by invoking a back end routine.
5565 The back end routine is responsible for adjusting the
5566 section contents as necessary, and (if using Rela relocs
5567 and generating a relocateable output file) adjusting the
5568 reloc addend as necessary.
5570 The back end routine does not have to worry about setting
5571 the reloc address or the reloc symbol index.
5573 The back end routine is given a pointer to the swapped in
5574 internal symbols, and can access the hash table entries
5575 for the external symbols via elf_sym_hashes (input_bfd).
5577 When generating relocateable output, the back end routine
5578 must handle STB_LOCAL/STT_SECTION symbols specially. The
5579 output symbol is going to be a section symbol
5580 corresponding to the output section, which will require
5581 the addend to be adjusted. */
5583 if (! (*relocate_section) (output_bfd, finfo->info,
5584 input_bfd, o, contents,
5585 internal_relocs,
5586 finfo->internal_syms,
5587 finfo->sections))
5588 return false;
5590 if (finfo->info->relocateable || finfo->info->emitrelocations)
5592 Elf_Internal_Rela *irela;
5593 Elf_Internal_Rela *irelaend;
5594 struct elf_link_hash_entry **rel_hash;
5595 Elf_Internal_Shdr *input_rel_hdr;
5597 /* Adjust the reloc addresses and symbol indices. */
5599 irela = internal_relocs;
5600 irelaend =
5601 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5602 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5603 + elf_section_data (o->output_section)->rel_count
5604 + elf_section_data (o->output_section)->rel_count2);
5605 for (; irela < irelaend; irela++, rel_hash++)
5607 unsigned long r_symndx;
5608 Elf_Internal_Sym *isym;
5609 asection *sec;
5611 irela->r_offset += o->output_offset;
5613 /* Relocs in an executable have to be virtual addresses. */
5614 if (finfo->info->emitrelocations)
5615 irela->r_offset += o->output_section->vma;
5617 r_symndx = ELF_R_SYM (irela->r_info);
5619 if (r_symndx == 0)
5620 continue;
5622 if (r_symndx >= locsymcount
5623 || (elf_bad_symtab (input_bfd)
5624 && finfo->sections[r_symndx] == NULL))
5626 struct elf_link_hash_entry *rh;
5627 long indx;
5629 /* This is a reloc against a global symbol. We
5630 have not yet output all the local symbols, so
5631 we do not know the symbol index of any global
5632 symbol. We set the rel_hash entry for this
5633 reloc to point to the global hash table entry
5634 for this symbol. The symbol index is then
5635 set at the end of elf_bfd_final_link. */
5636 indx = r_symndx - extsymoff;
5637 rh = elf_sym_hashes (input_bfd)[indx];
5638 while (rh->root.type == bfd_link_hash_indirect
5639 || rh->root.type == bfd_link_hash_warning)
5640 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5642 /* Setting the index to -2 tells
5643 elf_link_output_extsym that this symbol is
5644 used by a reloc. */
5645 BFD_ASSERT (rh->indx < 0);
5646 rh->indx = -2;
5648 *rel_hash = rh;
5650 continue;
5653 /* This is a reloc against a local symbol. */
5655 *rel_hash = NULL;
5656 isym = finfo->internal_syms + r_symndx;
5657 sec = finfo->sections[r_symndx];
5658 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5660 /* I suppose the backend ought to fill in the
5661 section of any STT_SECTION symbol against a
5662 processor specific section. If we have
5663 discarded a section, the output_section will
5664 be the absolute section. */
5665 if (sec != NULL
5666 && (bfd_is_abs_section (sec)
5667 || (sec->output_section != NULL
5668 && bfd_is_abs_section (sec->output_section))))
5669 r_symndx = 0;
5670 else if (sec == NULL || sec->owner == NULL)
5672 bfd_set_error (bfd_error_bad_value);
5673 return false;
5675 else
5677 r_symndx = sec->output_section->target_index;
5678 BFD_ASSERT (r_symndx != 0);
5681 else
5683 if (finfo->indices[r_symndx] == -1)
5685 unsigned long link;
5686 const char *name;
5687 asection *osec;
5689 if (finfo->info->strip == strip_all)
5691 /* You can't do ld -r -s. */
5692 bfd_set_error (bfd_error_invalid_operation);
5693 return false;
5696 /* This symbol was skipped earlier, but
5697 since it is needed by a reloc, we
5698 must output it now. */
5699 link = symtab_hdr->sh_link;
5700 name = bfd_elf_string_from_elf_section (input_bfd,
5701 link,
5702 isym->st_name);
5703 if (name == NULL)
5704 return false;
5706 osec = sec->output_section;
5707 isym->st_shndx =
5708 _bfd_elf_section_from_bfd_section (output_bfd,
5709 osec);
5710 if (isym->st_shndx == (unsigned short) -1)
5711 return false;
5713 isym->st_value += sec->output_offset;
5714 if (! finfo->info->relocateable)
5715 isym->st_value += osec->vma;
5717 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5719 if (! elf_link_output_sym (finfo, name, isym, sec))
5720 return false;
5723 r_symndx = finfo->indices[r_symndx];
5726 irela->r_info = ELF_R_INFO (r_symndx,
5727 ELF_R_TYPE (irela->r_info));
5730 /* Swap out the relocs. */
5731 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5732 elf_link_output_relocs (output_bfd, o,
5733 input_rel_hdr,
5734 internal_relocs);
5735 internal_relocs
5736 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5737 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5738 if (input_rel_hdr)
5739 elf_link_output_relocs (output_bfd, o,
5740 input_rel_hdr,
5741 internal_relocs);
5745 /* Write out the modified section contents. */
5746 if (elf_section_data (o)->stab_info == NULL)
5748 if (! (o->flags & SEC_EXCLUDE) &&
5749 ! bfd_set_section_contents (output_bfd, o->output_section,
5750 contents, o->output_offset,
5751 (o->_cooked_size != 0
5752 ? o->_cooked_size
5753 : o->_raw_size)))
5754 return false;
5756 else
5758 if (! (_bfd_write_section_stabs
5759 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5760 o, &elf_section_data (o)->stab_info, contents)))
5761 return false;
5765 return true;
5768 /* Generate a reloc when linking an ELF file. This is a reloc
5769 requested by the linker, and does come from any input file. This
5770 is used to build constructor and destructor tables when linking
5771 with -Ur. */
5773 static boolean
5774 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5775 bfd *output_bfd;
5776 struct bfd_link_info *info;
5777 asection *output_section;
5778 struct bfd_link_order *link_order;
5780 reloc_howto_type *howto;
5781 long indx;
5782 bfd_vma offset;
5783 bfd_vma addend;
5784 struct elf_link_hash_entry **rel_hash_ptr;
5785 Elf_Internal_Shdr *rel_hdr;
5786 struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
5788 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5789 if (howto == NULL)
5791 bfd_set_error (bfd_error_bad_value);
5792 return false;
5795 addend = link_order->u.reloc.p->addend;
5797 /* Figure out the symbol index. */
5798 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5799 + elf_section_data (output_section)->rel_count
5800 + elf_section_data (output_section)->rel_count2);
5801 if (link_order->type == bfd_section_reloc_link_order)
5803 indx = link_order->u.reloc.p->u.section->target_index;
5804 BFD_ASSERT (indx != 0);
5805 *rel_hash_ptr = NULL;
5807 else
5809 struct elf_link_hash_entry *h;
5811 /* Treat a reloc against a defined symbol as though it were
5812 actually against the section. */
5813 h = ((struct elf_link_hash_entry *)
5814 bfd_wrapped_link_hash_lookup (output_bfd, info,
5815 link_order->u.reloc.p->u.name,
5816 false, false, true));
5817 if (h != NULL
5818 && (h->root.type == bfd_link_hash_defined
5819 || h->root.type == bfd_link_hash_defweak))
5821 asection *section;
5823 section = h->root.u.def.section;
5824 indx = section->output_section->target_index;
5825 *rel_hash_ptr = NULL;
5826 /* It seems that we ought to add the symbol value to the
5827 addend here, but in practice it has already been added
5828 because it was passed to constructor_callback. */
5829 addend += section->output_section->vma + section->output_offset;
5831 else if (h != NULL)
5833 /* Setting the index to -2 tells elf_link_output_extsym that
5834 this symbol is used by a reloc. */
5835 h->indx = -2;
5836 *rel_hash_ptr = h;
5837 indx = 0;
5839 else
5841 if (! ((*info->callbacks->unattached_reloc)
5842 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5843 (asection *) NULL, (bfd_vma) 0)))
5844 return false;
5845 indx = 0;
5849 /* If this is an inplace reloc, we must write the addend into the
5850 object file. */
5851 if (howto->partial_inplace && addend != 0)
5853 bfd_size_type size;
5854 bfd_reloc_status_type rstat;
5855 bfd_byte *buf;
5856 boolean ok;
5858 size = bfd_get_reloc_size (howto);
5859 buf = (bfd_byte *) bfd_zmalloc (size);
5860 if (buf == (bfd_byte *) NULL)
5861 return false;
5862 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5863 switch (rstat)
5865 case bfd_reloc_ok:
5866 break;
5867 default:
5868 case bfd_reloc_outofrange:
5869 abort ();
5870 case bfd_reloc_overflow:
5871 if (! ((*info->callbacks->reloc_overflow)
5872 (info,
5873 (link_order->type == bfd_section_reloc_link_order
5874 ? bfd_section_name (output_bfd,
5875 link_order->u.reloc.p->u.section)
5876 : link_order->u.reloc.p->u.name),
5877 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5878 (bfd_vma) 0)))
5880 free (buf);
5881 return false;
5883 break;
5885 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5886 (file_ptr) link_order->offset, size);
5887 free (buf);
5888 if (! ok)
5889 return false;
5892 /* The address of a reloc is relative to the section in a
5893 relocateable file, and is a virtual address in an executable
5894 file. */
5895 offset = link_order->offset;
5896 if (! info->relocateable)
5897 offset += output_section->vma;
5899 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5901 if (rel_hdr->sh_type == SHT_REL)
5903 Elf_Internal_Rel irel;
5904 Elf_External_Rel *erel;
5906 irel.r_offset = offset;
5907 irel.r_info = ELF_R_INFO (indx, howto->type);
5908 erel = ((Elf_External_Rel *) rel_hdr->contents
5909 + elf_section_data (output_section)->rel_count);
5910 if (bed->s->swap_reloc_out)
5911 (*bed->s->swap_reloc_out) (output_bfd, &irel, (bfd_byte *) erel);
5912 else
5913 elf_swap_reloc_out (output_bfd, &irel, erel);
5915 else
5917 Elf_Internal_Rela irela;
5918 Elf_External_Rela *erela;
5920 irela.r_offset = offset;
5921 irela.r_info = ELF_R_INFO (indx, howto->type);
5922 irela.r_addend = addend;
5923 erela = ((Elf_External_Rela *) rel_hdr->contents
5924 + elf_section_data (output_section)->rel_count);
5925 if (bed->s->swap_reloca_out)
5926 (*bed->s->swap_reloca_out) (output_bfd, &irela, (bfd_byte *) erela);
5927 else
5928 elf_swap_reloca_out (output_bfd, &irela, erela);
5931 ++elf_section_data (output_section)->rel_count;
5933 return true;
5937 /* Allocate a pointer to live in a linker created section. */
5939 boolean
5940 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5941 bfd *abfd;
5942 struct bfd_link_info *info;
5943 elf_linker_section_t *lsect;
5944 struct elf_link_hash_entry *h;
5945 const Elf_Internal_Rela *rel;
5947 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5948 elf_linker_section_pointers_t *linker_section_ptr;
5949 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5951 BFD_ASSERT (lsect != NULL);
5953 /* Is this a global symbol? */
5954 if (h != NULL)
5956 /* Has this symbol already been allocated, if so, our work is done */
5957 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5958 rel->r_addend,
5959 lsect->which))
5960 return true;
5962 ptr_linker_section_ptr = &h->linker_section_pointer;
5963 /* Make sure this symbol is output as a dynamic symbol. */
5964 if (h->dynindx == -1)
5966 if (! elf_link_record_dynamic_symbol (info, h))
5967 return false;
5970 if (lsect->rel_section)
5971 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5974 else /* Allocation of a pointer to a local symbol */
5976 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5978 /* Allocate a table to hold the local symbols if first time */
5979 if (!ptr)
5981 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5982 register unsigned int i;
5984 ptr = (elf_linker_section_pointers_t **)
5985 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5987 if (!ptr)
5988 return false;
5990 elf_local_ptr_offsets (abfd) = ptr;
5991 for (i = 0; i < num_symbols; i++)
5992 ptr[i] = (elf_linker_section_pointers_t *)0;
5995 /* Has this symbol already been allocated, if so, our work is done */
5996 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5997 rel->r_addend,
5998 lsect->which))
5999 return true;
6001 ptr_linker_section_ptr = &ptr[r_symndx];
6003 if (info->shared)
6005 /* If we are generating a shared object, we need to
6006 output a R_<xxx>_RELATIVE reloc so that the
6007 dynamic linker can adjust this GOT entry. */
6008 BFD_ASSERT (lsect->rel_section != NULL);
6009 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
6013 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
6014 from internal memory. */
6015 BFD_ASSERT (ptr_linker_section_ptr != NULL);
6016 linker_section_ptr = (elf_linker_section_pointers_t *)
6017 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
6019 if (!linker_section_ptr)
6020 return false;
6022 linker_section_ptr->next = *ptr_linker_section_ptr;
6023 linker_section_ptr->addend = rel->r_addend;
6024 linker_section_ptr->which = lsect->which;
6025 linker_section_ptr->written_address_p = false;
6026 *ptr_linker_section_ptr = linker_section_ptr;
6028 #if 0
6029 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
6031 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
6032 lsect->hole_offset += ARCH_SIZE / 8;
6033 lsect->sym_offset += ARCH_SIZE / 8;
6034 if (lsect->sym_hash) /* Bump up symbol value if needed */
6036 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
6037 #ifdef DEBUG
6038 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
6039 lsect->sym_hash->root.root.string,
6040 (long)ARCH_SIZE / 8,
6041 (long)lsect->sym_hash->root.u.def.value);
6042 #endif
6045 else
6046 #endif
6047 linker_section_ptr->offset = lsect->section->_raw_size;
6049 lsect->section->_raw_size += ARCH_SIZE / 8;
6051 #ifdef DEBUG
6052 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
6053 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
6054 #endif
6056 return true;
6060 #if ARCH_SIZE==64
6061 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
6062 #endif
6063 #if ARCH_SIZE==32
6064 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
6065 #endif
6067 /* Fill in the address for a pointer generated in alinker section. */
6069 bfd_vma
6070 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
6071 bfd *output_bfd;
6072 bfd *input_bfd;
6073 struct bfd_link_info *info;
6074 elf_linker_section_t *lsect;
6075 struct elf_link_hash_entry *h;
6076 bfd_vma relocation;
6077 const Elf_Internal_Rela *rel;
6078 int relative_reloc;
6080 elf_linker_section_pointers_t *linker_section_ptr;
6082 BFD_ASSERT (lsect != NULL);
6084 if (h != NULL) /* global symbol */
6086 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6087 rel->r_addend,
6088 lsect->which);
6090 BFD_ASSERT (linker_section_ptr != NULL);
6092 if (! elf_hash_table (info)->dynamic_sections_created
6093 || (info->shared
6094 && info->symbolic
6095 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
6097 /* This is actually a static link, or it is a
6098 -Bsymbolic link and the symbol is defined
6099 locally. We must initialize this entry in the
6100 global section.
6102 When doing a dynamic link, we create a .rela.<xxx>
6103 relocation entry to initialize the value. This
6104 is done in the finish_dynamic_symbol routine. */
6105 if (!linker_section_ptr->written_address_p)
6107 linker_section_ptr->written_address_p = true;
6108 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6109 lsect->section->contents + linker_section_ptr->offset);
6113 else /* local symbol */
6115 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6116 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6117 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6118 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6119 rel->r_addend,
6120 lsect->which);
6122 BFD_ASSERT (linker_section_ptr != NULL);
6124 /* Write out pointer if it hasn't been rewritten out before */
6125 if (!linker_section_ptr->written_address_p)
6127 linker_section_ptr->written_address_p = true;
6128 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6129 lsect->section->contents + linker_section_ptr->offset);
6131 if (info->shared)
6133 asection *srel = lsect->rel_section;
6134 Elf_Internal_Rela outrel;
6136 /* We need to generate a relative reloc for the dynamic linker. */
6137 if (!srel)
6138 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6139 lsect->rel_name);
6141 BFD_ASSERT (srel != NULL);
6143 outrel.r_offset = (lsect->section->output_section->vma
6144 + lsect->section->output_offset
6145 + linker_section_ptr->offset);
6146 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6147 outrel.r_addend = 0;
6148 elf_swap_reloca_out (output_bfd, &outrel,
6149 (((Elf_External_Rela *)
6150 lsect->section->contents)
6151 + elf_section_data (lsect->section)->rel_count));
6152 ++elf_section_data (lsect->section)->rel_count;
6157 relocation = (lsect->section->output_offset
6158 + linker_section_ptr->offset
6159 - lsect->hole_offset
6160 - lsect->sym_offset);
6162 #ifdef DEBUG
6163 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6164 lsect->name, (long)relocation, (long)relocation);
6165 #endif
6167 /* Subtract out the addend, because it will get added back in by the normal
6168 processing. */
6169 return relocation - linker_section_ptr->addend;
6172 /* Garbage collect unused sections. */
6174 static boolean elf_gc_mark
6175 PARAMS ((struct bfd_link_info *info, asection *sec,
6176 asection * (*gc_mark_hook)
6177 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6178 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6180 static boolean elf_gc_sweep
6181 PARAMS ((struct bfd_link_info *info,
6182 boolean (*gc_sweep_hook)
6183 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6184 const Elf_Internal_Rela *relocs))));
6186 static boolean elf_gc_sweep_symbol
6187 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6189 static boolean elf_gc_allocate_got_offsets
6190 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6192 static boolean elf_gc_propagate_vtable_entries_used
6193 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6195 static boolean elf_gc_smash_unused_vtentry_relocs
6196 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6198 /* The mark phase of garbage collection. For a given section, mark
6199 it, and all the sections which define symbols to which it refers. */
6201 static boolean
6202 elf_gc_mark (info, sec, gc_mark_hook)
6203 struct bfd_link_info *info;
6204 asection *sec;
6205 asection * (*gc_mark_hook)
6206 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6207 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6209 boolean ret = true;
6211 sec->gc_mark = 1;
6213 /* Look through the section relocs. */
6215 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6217 Elf_Internal_Rela *relstart, *rel, *relend;
6218 Elf_Internal_Shdr *symtab_hdr;
6219 struct elf_link_hash_entry **sym_hashes;
6220 size_t nlocsyms;
6221 size_t extsymoff;
6222 Elf_External_Sym *locsyms, *freesyms = NULL;
6223 bfd *input_bfd = sec->owner;
6224 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6226 /* GCFIXME: how to arrange so that relocs and symbols are not
6227 reread continually? */
6229 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6230 sym_hashes = elf_sym_hashes (input_bfd);
6232 /* Read the local symbols. */
6233 if (elf_bad_symtab (input_bfd))
6235 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6236 extsymoff = 0;
6238 else
6239 extsymoff = nlocsyms = symtab_hdr->sh_info;
6240 if (symtab_hdr->contents)
6241 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6242 else if (nlocsyms == 0)
6243 locsyms = NULL;
6244 else
6246 locsyms = freesyms =
6247 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6248 if (freesyms == NULL
6249 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6250 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6251 nlocsyms, input_bfd)
6252 != nlocsyms * sizeof (Elf_External_Sym)))
6254 ret = false;
6255 goto out1;
6259 /* Read the relocations. */
6260 relstart = (NAME(_bfd_elf,link_read_relocs)
6261 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6262 info->keep_memory));
6263 if (relstart == NULL)
6265 ret = false;
6266 goto out1;
6268 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6270 for (rel = relstart; rel < relend; rel++)
6272 unsigned long r_symndx;
6273 asection *rsec;
6274 struct elf_link_hash_entry *h;
6275 Elf_Internal_Sym s;
6277 r_symndx = ELF_R_SYM (rel->r_info);
6278 if (r_symndx == 0)
6279 continue;
6281 if (elf_bad_symtab (sec->owner))
6283 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6284 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6285 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6286 else
6288 h = sym_hashes[r_symndx - extsymoff];
6289 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6292 else if (r_symndx >= nlocsyms)
6294 h = sym_hashes[r_symndx - extsymoff];
6295 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6297 else
6299 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6300 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6303 if (rsec && !rsec->gc_mark)
6304 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6306 ret = false;
6307 goto out2;
6311 out2:
6312 if (!info->keep_memory)
6313 free (relstart);
6314 out1:
6315 if (freesyms)
6316 free (freesyms);
6319 return ret;
6322 /* The sweep phase of garbage collection. Remove all garbage sections. */
6324 static boolean
6325 elf_gc_sweep (info, gc_sweep_hook)
6326 struct bfd_link_info *info;
6327 boolean (*gc_sweep_hook)
6328 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6329 const Elf_Internal_Rela *relocs));
6331 bfd *sub;
6333 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6335 asection *o;
6337 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6338 continue;
6340 for (o = sub->sections; o != NULL; o = o->next)
6342 /* Keep special sections. Keep .debug sections. */
6343 if ((o->flags & SEC_LINKER_CREATED)
6344 || (o->flags & SEC_DEBUGGING))
6345 o->gc_mark = 1;
6347 if (o->gc_mark)
6348 continue;
6350 /* Skip sweeping sections already excluded. */
6351 if (o->flags & SEC_EXCLUDE)
6352 continue;
6354 /* Since this is early in the link process, it is simple
6355 to remove a section from the output. */
6356 o->flags |= SEC_EXCLUDE;
6358 /* But we also have to update some of the relocation
6359 info we collected before. */
6360 if (gc_sweep_hook
6361 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6363 Elf_Internal_Rela *internal_relocs;
6364 boolean r;
6366 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6367 (o->owner, o, NULL, NULL, info->keep_memory));
6368 if (internal_relocs == NULL)
6369 return false;
6371 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
6373 if (!info->keep_memory)
6374 free (internal_relocs);
6376 if (!r)
6377 return false;
6382 /* Remove the symbols that were in the swept sections from the dynamic
6383 symbol table. GCFIXME: Anyone know how to get them out of the
6384 static symbol table as well? */
6386 int i = 0;
6388 elf_link_hash_traverse (elf_hash_table (info),
6389 elf_gc_sweep_symbol,
6390 (PTR) &i);
6392 elf_hash_table (info)->dynsymcount = i;
6395 return true;
6398 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6400 static boolean
6401 elf_gc_sweep_symbol (h, idxptr)
6402 struct elf_link_hash_entry *h;
6403 PTR idxptr;
6405 int *idx = (int *) idxptr;
6407 if (h->dynindx != -1
6408 && ((h->root.type != bfd_link_hash_defined
6409 && h->root.type != bfd_link_hash_defweak)
6410 || h->root.u.def.section->gc_mark))
6411 h->dynindx = (*idx)++;
6413 return true;
6416 /* Propogate collected vtable information. This is called through
6417 elf_link_hash_traverse. */
6419 static boolean
6420 elf_gc_propagate_vtable_entries_used (h, okp)
6421 struct elf_link_hash_entry *h;
6422 PTR okp;
6424 /* Those that are not vtables. */
6425 if (h->vtable_parent == NULL)
6426 return true;
6428 /* Those vtables that do not have parents, we cannot merge. */
6429 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6430 return true;
6432 /* If we've already been done, exit. */
6433 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6434 return true;
6436 /* Make sure the parent's table is up to date. */
6437 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6439 if (h->vtable_entries_used == NULL)
6441 /* None of this table's entries were referenced. Re-use the
6442 parent's table. */
6443 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6444 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6446 else
6448 size_t n;
6449 boolean *cu, *pu;
6451 /* Or the parent's entries into ours. */
6452 cu = h->vtable_entries_used;
6453 cu[-1] = true;
6454 pu = h->vtable_parent->vtable_entries_used;
6455 if (pu != NULL)
6457 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6458 while (--n != 0)
6460 if (*pu) *cu = true;
6461 pu++, cu++;
6466 return true;
6469 static boolean
6470 elf_gc_smash_unused_vtentry_relocs (h, okp)
6471 struct elf_link_hash_entry *h;
6472 PTR okp;
6474 asection *sec;
6475 bfd_vma hstart, hend;
6476 Elf_Internal_Rela *relstart, *relend, *rel;
6477 struct elf_backend_data *bed;
6479 /* Take care of both those symbols that do not describe vtables as
6480 well as those that are not loaded. */
6481 if (h->vtable_parent == NULL)
6482 return true;
6484 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6485 || h->root.type == bfd_link_hash_defweak);
6487 sec = h->root.u.def.section;
6488 hstart = h->root.u.def.value;
6489 hend = hstart + h->size;
6491 relstart = (NAME(_bfd_elf,link_read_relocs)
6492 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6493 if (!relstart)
6494 return *(boolean *)okp = false;
6495 bed = get_elf_backend_data (sec->owner);
6496 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6498 for (rel = relstart; rel < relend; ++rel)
6499 if (rel->r_offset >= hstart && rel->r_offset < hend)
6501 /* If the entry is in use, do nothing. */
6502 if (h->vtable_entries_used
6503 && (rel->r_offset - hstart) < h->vtable_entries_size)
6505 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6506 if (h->vtable_entries_used[entry])
6507 continue;
6509 /* Otherwise, kill it. */
6510 rel->r_offset = rel->r_info = rel->r_addend = 0;
6513 return true;
6516 /* Do mark and sweep of unused sections. */
6518 boolean
6519 elf_gc_sections (abfd, info)
6520 bfd *abfd;
6521 struct bfd_link_info *info;
6523 boolean ok = true;
6524 bfd *sub;
6525 asection * (*gc_mark_hook)
6526 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6527 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6529 if (!get_elf_backend_data (abfd)->can_gc_sections
6530 || info->relocateable || info->emitrelocations
6531 || elf_hash_table (info)->dynamic_sections_created)
6532 return true;
6534 /* Apply transitive closure to the vtable entry usage info. */
6535 elf_link_hash_traverse (elf_hash_table (info),
6536 elf_gc_propagate_vtable_entries_used,
6537 (PTR) &ok);
6538 if (!ok)
6539 return false;
6541 /* Kill the vtable relocations that were not used. */
6542 elf_link_hash_traverse (elf_hash_table (info),
6543 elf_gc_smash_unused_vtentry_relocs,
6544 (PTR) &ok);
6545 if (!ok)
6546 return false;
6548 /* Grovel through relocs to find out who stays ... */
6550 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6551 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6553 asection *o;
6555 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6556 continue;
6558 for (o = sub->sections; o != NULL; o = o->next)
6560 if (o->flags & SEC_KEEP)
6561 if (!elf_gc_mark (info, o, gc_mark_hook))
6562 return false;
6566 /* ... and mark SEC_EXCLUDE for those that go. */
6567 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6568 return false;
6570 return true;
6573 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6575 boolean
6576 elf_gc_record_vtinherit (abfd, sec, h, offset)
6577 bfd *abfd;
6578 asection *sec;
6579 struct elf_link_hash_entry *h;
6580 bfd_vma offset;
6582 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6583 struct elf_link_hash_entry **search, *child;
6584 bfd_size_type extsymcount;
6586 /* The sh_info field of the symtab header tells us where the
6587 external symbols start. We don't care about the local symbols at
6588 this point. */
6589 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6590 if (!elf_bad_symtab (abfd))
6591 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6593 sym_hashes = elf_sym_hashes (abfd);
6594 sym_hashes_end = sym_hashes + extsymcount;
6596 /* Hunt down the child symbol, which is in this section at the same
6597 offset as the relocation. */
6598 for (search = sym_hashes; search != sym_hashes_end; ++search)
6600 if ((child = *search) != NULL
6601 && (child->root.type == bfd_link_hash_defined
6602 || child->root.type == bfd_link_hash_defweak)
6603 && child->root.u.def.section == sec
6604 && child->root.u.def.value == offset)
6605 goto win;
6608 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6609 bfd_get_filename (abfd), sec->name,
6610 (unsigned long)offset);
6611 bfd_set_error (bfd_error_invalid_operation);
6612 return false;
6614 win:
6615 if (!h)
6617 /* This *should* only be the absolute section. It could potentially
6618 be that someone has defined a non-global vtable though, which
6619 would be bad. It isn't worth paging in the local symbols to be
6620 sure though; that case should simply be handled by the assembler. */
6622 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6624 else
6625 child->vtable_parent = h;
6627 return true;
6630 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6632 boolean
6633 elf_gc_record_vtentry (abfd, sec, h, addend)
6634 bfd *abfd ATTRIBUTE_UNUSED;
6635 asection *sec ATTRIBUTE_UNUSED;
6636 struct elf_link_hash_entry *h;
6637 bfd_vma addend;
6639 if (addend >= h->vtable_entries_size)
6641 size_t size, bytes;
6642 boolean *ptr = h->vtable_entries_used;
6644 /* While the symbol is undefined, we have to be prepared to handle
6645 a zero size. */
6646 if (h->root.type == bfd_link_hash_undefined)
6647 size = addend;
6648 else
6650 size = h->size;
6651 if (size < addend)
6653 /* Oops! We've got a reference past the defined end of
6654 the table. This is probably a bug -- shall we warn? */
6655 size = addend;
6659 /* Allocate one extra entry for use as a "done" flag for the
6660 consolidation pass. */
6661 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6663 if (ptr)
6665 ptr = bfd_realloc (ptr - 1, bytes);
6667 if (ptr != NULL)
6669 size_t oldbytes;
6671 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6672 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6675 else
6676 ptr = bfd_zmalloc (bytes);
6678 if (ptr == NULL)
6679 return false;
6681 /* And arrange for that done flag to be at index -1. */
6682 h->vtable_entries_used = ptr + 1;
6683 h->vtable_entries_size = size;
6686 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6688 return true;
6691 /* And an accompanying bit to work out final got entry offsets once
6692 we're done. Should be called from final_link. */
6694 boolean
6695 elf_gc_common_finalize_got_offsets (abfd, info)
6696 bfd *abfd;
6697 struct bfd_link_info *info;
6699 bfd *i;
6700 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6701 bfd_vma gotoff;
6703 /* The GOT offset is relative to the .got section, but the GOT header is
6704 put into the .got.plt section, if the backend uses it. */
6705 if (bed->want_got_plt)
6706 gotoff = 0;
6707 else
6708 gotoff = bed->got_header_size;
6710 /* Do the local .got entries first. */
6711 for (i = info->input_bfds; i; i = i->link_next)
6713 bfd_signed_vma *local_got;
6714 bfd_size_type j, locsymcount;
6715 Elf_Internal_Shdr *symtab_hdr;
6717 if (bfd_get_flavour (i) != bfd_target_elf_flavour)
6718 continue;
6720 local_got = elf_local_got_refcounts (i);
6721 if (!local_got)
6722 continue;
6724 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6725 if (elf_bad_symtab (i))
6726 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6727 else
6728 locsymcount = symtab_hdr->sh_info;
6730 for (j = 0; j < locsymcount; ++j)
6732 if (local_got[j] > 0)
6734 local_got[j] = gotoff;
6735 gotoff += ARCH_SIZE / 8;
6737 else
6738 local_got[j] = (bfd_vma) -1;
6742 /* Then the global .got entries. .plt refcounts are handled by
6743 adjust_dynamic_symbol */
6744 elf_link_hash_traverse (elf_hash_table (info),
6745 elf_gc_allocate_got_offsets,
6746 (PTR) &gotoff);
6747 return true;
6750 /* We need a special top-level link routine to convert got reference counts
6751 to real got offsets. */
6753 static boolean
6754 elf_gc_allocate_got_offsets (h, offarg)
6755 struct elf_link_hash_entry *h;
6756 PTR offarg;
6758 bfd_vma *off = (bfd_vma *) offarg;
6760 if (h->got.refcount > 0)
6762 h->got.offset = off[0];
6763 off[0] += ARCH_SIZE / 8;
6765 else
6766 h->got.offset = (bfd_vma) -1;
6768 return true;
6771 /* Many folk need no more in the way of final link than this, once
6772 got entry reference counting is enabled. */
6774 boolean
6775 elf_gc_common_final_link (abfd, info)
6776 bfd *abfd;
6777 struct bfd_link_info *info;
6779 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6780 return false;
6782 /* Invoke the regular ELF backend linker to do all the work. */
6783 return elf_bfd_final_link (abfd, info);
6786 /* This function will be called though elf_link_hash_traverse to store
6787 all hash value of the exported symbols in an array. */
6789 static boolean
6790 elf_collect_hash_codes (h, data)
6791 struct elf_link_hash_entry *h;
6792 PTR data;
6794 unsigned long **valuep = (unsigned long **) data;
6795 const char *name;
6796 char *p;
6797 unsigned long ha;
6798 char *alc = NULL;
6800 /* Ignore indirect symbols. These are added by the versioning code. */
6801 if (h->dynindx == -1)
6802 return true;
6804 name = h->root.root.string;
6805 p = strchr (name, ELF_VER_CHR);
6806 if (p != NULL)
6808 alc = bfd_malloc (p - name + 1);
6809 memcpy (alc, name, p - name);
6810 alc[p - name] = '\0';
6811 name = alc;
6814 /* Compute the hash value. */
6815 ha = bfd_elf_hash (name);
6817 /* Store the found hash value in the array given as the argument. */
6818 *(*valuep)++ = ha;
6820 /* And store it in the struct so that we can put it in the hash table
6821 later. */
6822 h->elf_hash_value = ha;
6824 if (alc != NULL)
6825 free (alc);
6827 return true;