file gprof.info-2 was initially added on branch binutils-2_10-branch.
[binutils.git] / bfd / elflink.h
blobf1dab7059f228c383813b3f58c7ba281f1880f4a
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 visibility_changed = false;
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 if (! dynamic)
1055 /* If we are creating a shared library, create all the dynamic
1056 sections immediately. We need to attach them to something,
1057 so we attach them to this BFD, provided it is the right
1058 format. FIXME: If there are no input BFD's of the same
1059 format as the output, we can't make a shared library. */
1060 if (info->shared
1061 && ! elf_hash_table (info)->dynamic_sections_created
1062 && abfd->xvec == info->hash->creator)
1064 if (! elf_link_create_dynamic_sections (abfd, info))
1065 goto error_return;
1068 else
1070 asection *s;
1071 boolean add_needed;
1072 const char *name;
1073 bfd_size_type oldsize;
1074 bfd_size_type strindex;
1076 /* Find the name to use in a DT_NEEDED entry that refers to this
1077 object. If the object has a DT_SONAME entry, we use it.
1078 Otherwise, if the generic linker stuck something in
1079 elf_dt_name, we use that. Otherwise, we just use the file
1080 name. If the generic linker put a null string into
1081 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
1082 there is a DT_SONAME entry. */
1083 add_needed = true;
1084 name = bfd_get_filename (abfd);
1085 if (elf_dt_name (abfd) != NULL)
1087 name = elf_dt_name (abfd);
1088 if (*name == '\0')
1089 add_needed = false;
1091 s = bfd_get_section_by_name (abfd, ".dynamic");
1092 if (s != NULL)
1094 Elf_External_Dyn *extdyn;
1095 Elf_External_Dyn *extdynend;
1096 int elfsec;
1097 unsigned long link;
1099 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
1100 if (dynbuf == NULL)
1101 goto error_return;
1103 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
1104 (file_ptr) 0, s->_raw_size))
1105 goto error_return;
1107 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1108 if (elfsec == -1)
1109 goto error_return;
1110 link = elf_elfsections (abfd)[elfsec]->sh_link;
1113 /* The shared libraries distributed with hpux11 have a bogus
1114 sh_link field for the ".dynamic" section. This code detects
1115 when LINK refers to a section that is not a string table and
1116 tries to find the string table for the ".dynsym" section
1117 instead. */
1118 Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[link];
1119 if (hdr->sh_type != SHT_STRTAB)
1121 asection *s = bfd_get_section_by_name (abfd, ".dynsym");
1122 int elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1123 if (elfsec == -1)
1124 goto error_return;
1125 link = elf_elfsections (abfd)[elfsec]->sh_link;
1129 extdyn = dynbuf;
1130 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
1131 for (; extdyn < extdynend; extdyn++)
1133 Elf_Internal_Dyn dyn;
1135 elf_swap_dyn_in (abfd, extdyn, &dyn);
1136 if (dyn.d_tag == DT_SONAME)
1138 name = bfd_elf_string_from_elf_section (abfd, link,
1139 dyn.d_un.d_val);
1140 if (name == NULL)
1141 goto error_return;
1143 if (dyn.d_tag == DT_NEEDED)
1145 struct bfd_link_needed_list *n, **pn;
1146 char *fnm, *anm;
1148 n = ((struct bfd_link_needed_list *)
1149 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1150 fnm = bfd_elf_string_from_elf_section (abfd, link,
1151 dyn.d_un.d_val);
1152 if (n == NULL || fnm == NULL)
1153 goto error_return;
1154 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1155 if (anm == NULL)
1156 goto error_return;
1157 strcpy (anm, fnm);
1158 n->name = anm;
1159 n->by = abfd;
1160 n->next = NULL;
1161 for (pn = &elf_hash_table (info)->needed;
1162 *pn != NULL;
1163 pn = &(*pn)->next)
1165 *pn = n;
1169 free (dynbuf);
1170 dynbuf = NULL;
1173 /* We do not want to include any of the sections in a dynamic
1174 object in the output file. We hack by simply clobbering the
1175 list of sections in the BFD. This could be handled more
1176 cleanly by, say, a new section flag; the existing
1177 SEC_NEVER_LOAD flag is not the one we want, because that one
1178 still implies that the section takes up space in the output
1179 file. */
1180 abfd->sections = NULL;
1181 abfd->section_count = 0;
1183 /* If this is the first dynamic object found in the link, create
1184 the special sections required for dynamic linking. */
1185 if (! elf_hash_table (info)->dynamic_sections_created)
1187 if (! elf_link_create_dynamic_sections (abfd, info))
1188 goto error_return;
1191 if (add_needed)
1193 /* Add a DT_NEEDED entry for this dynamic object. */
1194 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1195 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
1196 true, false);
1197 if (strindex == (bfd_size_type) -1)
1198 goto error_return;
1200 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1202 asection *sdyn;
1203 Elf_External_Dyn *dyncon, *dynconend;
1205 /* The hash table size did not change, which means that
1206 the dynamic object name was already entered. If we
1207 have already included this dynamic object in the
1208 link, just ignore it. There is no reason to include
1209 a particular dynamic object more than once. */
1210 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1211 ".dynamic");
1212 BFD_ASSERT (sdyn != NULL);
1214 dyncon = (Elf_External_Dyn *) sdyn->contents;
1215 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1216 sdyn->_raw_size);
1217 for (; dyncon < dynconend; dyncon++)
1219 Elf_Internal_Dyn dyn;
1221 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
1222 &dyn);
1223 if (dyn.d_tag == DT_NEEDED
1224 && dyn.d_un.d_val == strindex)
1226 if (buf != NULL)
1227 free (buf);
1228 if (extversym != NULL)
1229 free (extversym);
1230 return true;
1235 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1236 goto error_return;
1239 /* Save the SONAME, if there is one, because sometimes the
1240 linker emulation code will need to know it. */
1241 if (*name == '\0')
1242 name = bfd_get_filename (abfd);
1243 elf_dt_name (abfd) = name;
1246 if (bfd_seek (abfd,
1247 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
1248 SEEK_SET) != 0
1249 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
1250 != extsymcount * sizeof (Elf_External_Sym)))
1251 goto error_return;
1253 weaks = NULL;
1255 ever = extversym != NULL ? extversym + extsymoff : NULL;
1256 esymend = buf + extsymcount;
1257 for (esym = buf;
1258 esym < esymend;
1259 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1261 Elf_Internal_Sym sym;
1262 int bind;
1263 bfd_vma value;
1264 asection *sec;
1265 flagword flags;
1266 const char *name;
1267 struct elf_link_hash_entry *h;
1268 boolean definition;
1269 boolean size_change_ok, type_change_ok;
1270 boolean new_weakdef;
1271 unsigned int old_alignment;
1273 elf_swap_symbol_in (abfd, esym, &sym);
1275 flags = BSF_NO_FLAGS;
1276 sec = NULL;
1277 value = sym.st_value;
1278 *sym_hash = NULL;
1280 bind = ELF_ST_BIND (sym.st_info);
1281 if (bind == STB_LOCAL)
1283 /* This should be impossible, since ELF requires that all
1284 global symbols follow all local symbols, and that sh_info
1285 point to the first global symbol. Unfortunatealy, Irix 5
1286 screws this up. */
1287 continue;
1289 else if (bind == STB_GLOBAL)
1291 if (sym.st_shndx != SHN_UNDEF
1292 && sym.st_shndx != SHN_COMMON)
1293 flags = BSF_GLOBAL;
1294 else
1295 flags = 0;
1297 else if (bind == STB_WEAK)
1298 flags = BSF_WEAK;
1299 else
1301 /* Leave it up to the processor backend. */
1304 if (sym.st_shndx == SHN_UNDEF)
1305 sec = bfd_und_section_ptr;
1306 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1308 sec = section_from_elf_index (abfd, sym.st_shndx);
1309 if (sec == NULL)
1310 sec = bfd_abs_section_ptr;
1311 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1312 value -= sec->vma;
1314 else if (sym.st_shndx == SHN_ABS)
1315 sec = bfd_abs_section_ptr;
1316 else if (sym.st_shndx == SHN_COMMON)
1318 sec = bfd_com_section_ptr;
1319 /* What ELF calls the size we call the value. What ELF
1320 calls the value we call the alignment. */
1321 value = sym.st_size;
1323 else
1325 /* Leave it up to the processor backend. */
1328 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1329 if (name == (const char *) NULL)
1330 goto error_return;
1332 if (add_symbol_hook)
1334 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1335 &value))
1336 goto error_return;
1338 /* The hook function sets the name to NULL if this symbol
1339 should be skipped for some reason. */
1340 if (name == (const char *) NULL)
1341 continue;
1344 /* Sanity check that all possibilities were handled. */
1345 if (sec == (asection *) NULL)
1347 bfd_set_error (bfd_error_bad_value);
1348 goto error_return;
1351 if (bfd_is_und_section (sec)
1352 || bfd_is_com_section (sec))
1353 definition = false;
1354 else
1355 definition = true;
1357 size_change_ok = false;
1358 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1359 old_alignment = 0;
1360 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1362 Elf_Internal_Versym iver;
1363 unsigned int vernum = 0;
1364 boolean override;
1366 if (ever != NULL)
1368 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1369 vernum = iver.vs_vers & VERSYM_VERSION;
1371 /* If this is a hidden symbol, or if it is not version
1372 1, we append the version name to the symbol name.
1373 However, we do not modify a non-hidden absolute
1374 symbol, because it might be the version symbol
1375 itself. FIXME: What if it isn't? */
1376 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1377 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1379 const char *verstr;
1380 int namelen, newlen;
1381 char *newname, *p;
1383 if (sym.st_shndx != SHN_UNDEF)
1385 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1387 (*_bfd_error_handler)
1388 (_("%s: %s: invalid version %u (max %d)"),
1389 bfd_get_filename (abfd), name, vernum,
1390 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1391 bfd_set_error (bfd_error_bad_value);
1392 goto error_return;
1394 else if (vernum > 1)
1395 verstr =
1396 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1397 else
1398 verstr = "";
1400 else
1402 /* We cannot simply test for the number of
1403 entries in the VERNEED section since the
1404 numbers for the needed versions do not start
1405 at 0. */
1406 Elf_Internal_Verneed *t;
1408 verstr = NULL;
1409 for (t = elf_tdata (abfd)->verref;
1410 t != NULL;
1411 t = t->vn_nextref)
1413 Elf_Internal_Vernaux *a;
1415 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1417 if (a->vna_other == vernum)
1419 verstr = a->vna_nodename;
1420 break;
1423 if (a != NULL)
1424 break;
1426 if (verstr == NULL)
1428 (*_bfd_error_handler)
1429 (_("%s: %s: invalid needed version %d"),
1430 bfd_get_filename (abfd), name, vernum);
1431 bfd_set_error (bfd_error_bad_value);
1432 goto error_return;
1436 namelen = strlen (name);
1437 newlen = namelen + strlen (verstr) + 2;
1438 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1439 ++newlen;
1441 newname = (char *) bfd_alloc (abfd, newlen);
1442 if (newname == NULL)
1443 goto error_return;
1444 strcpy (newname, name);
1445 p = newname + namelen;
1446 *p++ = ELF_VER_CHR;
1447 /* If this is a defined non-hidden version symbol,
1448 we add another @ to the name. This indicates the
1449 default version of the symbol. */
1450 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
1451 && sym.st_shndx != SHN_UNDEF)
1452 *p++ = ELF_VER_CHR;
1453 strcpy (p, verstr);
1455 name = newname;
1459 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1460 sym_hash, &override, &type_change_ok,
1461 &size_change_ok))
1462 goto error_return;
1464 if (override)
1465 definition = false;
1467 h = *sym_hash;
1468 while (h->root.type == bfd_link_hash_indirect
1469 || h->root.type == bfd_link_hash_warning)
1470 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1472 /* Remember the old alignment if this is a common symbol, so
1473 that we don't reduce the alignment later on. We can't
1474 check later, because _bfd_generic_link_add_one_symbol
1475 will set a default for the alignment which we want to
1476 override. */
1477 if (h->root.type == bfd_link_hash_common)
1478 old_alignment = h->root.u.c.p->alignment_power;
1480 if (elf_tdata (abfd)->verdef != NULL
1481 && ! override
1482 && vernum > 1
1483 && definition)
1484 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1487 if (! (_bfd_generic_link_add_one_symbol
1488 (info, abfd, name, flags, sec, value, (const char *) NULL,
1489 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1490 goto error_return;
1492 h = *sym_hash;
1493 while (h->root.type == bfd_link_hash_indirect
1494 || h->root.type == bfd_link_hash_warning)
1495 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1496 *sym_hash = h;
1498 new_weakdef = false;
1499 if (dynamic
1500 && definition
1501 && (flags & BSF_WEAK) != 0
1502 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1503 && info->hash->creator->flavour == bfd_target_elf_flavour
1504 && h->weakdef == NULL)
1506 /* Keep a list of all weak defined non function symbols from
1507 a dynamic object, using the weakdef field. Later in this
1508 function we will set the weakdef field to the correct
1509 value. We only put non-function symbols from dynamic
1510 objects on this list, because that happens to be the only
1511 time we need to know the normal symbol corresponding to a
1512 weak symbol, and the information is time consuming to
1513 figure out. If the weakdef field is not already NULL,
1514 then this symbol was already defined by some previous
1515 dynamic object, and we will be using that previous
1516 definition anyhow. */
1518 h->weakdef = weaks;
1519 weaks = h;
1520 new_weakdef = true;
1523 /* Set the alignment of a common symbol. */
1524 if (sym.st_shndx == SHN_COMMON
1525 && h->root.type == bfd_link_hash_common)
1527 unsigned int align;
1529 align = bfd_log2 (sym.st_value);
1530 if (align > old_alignment)
1531 h->root.u.c.p->alignment_power = align;
1534 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1536 int old_flags;
1537 boolean dynsym;
1538 int new_flag;
1540 /* Remember the symbol size and type. */
1541 if (sym.st_size != 0
1542 && (definition || h->size == 0))
1544 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1545 (*_bfd_error_handler)
1546 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1547 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1548 bfd_get_filename (abfd));
1550 h->size = sym.st_size;
1553 /* If this is a common symbol, then we always want H->SIZE
1554 to be the size of the common symbol. The code just above
1555 won't fix the size if a common symbol becomes larger. We
1556 don't warn about a size change here, because that is
1557 covered by --warn-common. */
1558 if (h->root.type == bfd_link_hash_common)
1559 h->size = h->root.u.c.size;
1561 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1562 && (definition || h->type == STT_NOTYPE))
1564 if (h->type != STT_NOTYPE
1565 && h->type != ELF_ST_TYPE (sym.st_info)
1566 && ! type_change_ok)
1567 (*_bfd_error_handler)
1568 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1569 name, h->type, ELF_ST_TYPE (sym.st_info),
1570 bfd_get_filename (abfd));
1572 h->type = ELF_ST_TYPE (sym.st_info);
1575 /* If st_other has a processor-specific meaning, specific code
1576 might be needed here. */
1577 if (sym.st_other != 0)
1579 /* Combine visibilities, using the most constraining one. */
1580 unsigned char hvis = ELF_ST_VISIBILITY (h->other);
1581 unsigned char symvis = ELF_ST_VISIBILITY (sym.st_other);
1583 if (symvis && (hvis > symvis || hvis == 0))
1585 visibility_changed = true;
1586 h->other = sym.st_other;
1589 /* If neither has visibility, use the st_other of the
1590 definition. This is an arbitrary choice, since the
1591 other bits have no general meaning. */
1592 if (!symvis && !hvis
1593 && (definition || h->other == 0))
1594 h->other = sym.st_other;
1597 /* Set a flag in the hash table entry indicating the type of
1598 reference or definition we just found. Keep a count of
1599 the number of dynamic symbols we find. A dynamic symbol
1600 is one which is referenced or defined by both a regular
1601 object and a shared object. */
1602 old_flags = h->elf_link_hash_flags;
1603 dynsym = false;
1604 if (! dynamic)
1606 if (! definition)
1608 new_flag = ELF_LINK_HASH_REF_REGULAR;
1609 if (bind != STB_WEAK)
1610 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1612 else
1613 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1614 if (info->shared
1615 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1616 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1617 dynsym = true;
1619 else
1621 if (! definition)
1622 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1623 else
1624 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1625 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1626 | ELF_LINK_HASH_REF_REGULAR)) != 0
1627 || (h->weakdef != NULL
1628 && ! new_weakdef
1629 && h->weakdef->dynindx != -1))
1630 dynsym = true;
1633 h->elf_link_hash_flags |= new_flag;
1635 /* If this symbol has a version, and it is the default
1636 version, we create an indirect symbol from the default
1637 name to the fully decorated name. This will cause
1638 external references which do not specify a version to be
1639 bound to this version of the symbol. */
1640 if (definition)
1642 char *p;
1644 p = strchr (name, ELF_VER_CHR);
1645 if (p != NULL && p[1] == ELF_VER_CHR)
1647 char *shortname;
1648 struct elf_link_hash_entry *hi;
1649 boolean override;
1651 shortname = bfd_hash_allocate (&info->hash->table,
1652 p - name + 1);
1653 if (shortname == NULL)
1654 goto error_return;
1655 strncpy (shortname, name, p - name);
1656 shortname[p - name] = '\0';
1658 /* We are going to create a new symbol. Merge it
1659 with any existing symbol with this name. For the
1660 purposes of the merge, act as though we were
1661 defining the symbol we just defined, although we
1662 actually going to define an indirect symbol. */
1663 type_change_ok = false;
1664 size_change_ok = false;
1665 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1666 &value, &hi, &override,
1667 &type_change_ok, &size_change_ok))
1668 goto error_return;
1670 if (! override)
1672 if (! (_bfd_generic_link_add_one_symbol
1673 (info, abfd, shortname, BSF_INDIRECT,
1674 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1675 collect, (struct bfd_link_hash_entry **) &hi)))
1676 goto error_return;
1678 else
1680 /* In this case the symbol named SHORTNAME is
1681 overriding the indirect symbol we want to
1682 add. We were planning on making SHORTNAME an
1683 indirect symbol referring to NAME. SHORTNAME
1684 is the name without a version. NAME is the
1685 fully versioned name, and it is the default
1686 version.
1688 Overriding means that we already saw a
1689 definition for the symbol SHORTNAME in a
1690 regular object, and it is overriding the
1691 symbol defined in the dynamic object.
1693 When this happens, we actually want to change
1694 NAME, the symbol we just added, to refer to
1695 SHORTNAME. This will cause references to
1696 NAME in the shared object to become
1697 references to SHORTNAME in the regular
1698 object. This is what we expect when we
1699 override a function in a shared object: that
1700 the references in the shared object will be
1701 mapped to the definition in the regular
1702 object. */
1704 while (hi->root.type == bfd_link_hash_indirect
1705 || hi->root.type == bfd_link_hash_warning)
1706 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1708 h->root.type = bfd_link_hash_indirect;
1709 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1710 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1712 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1713 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1714 if (hi->elf_link_hash_flags
1715 & (ELF_LINK_HASH_REF_REGULAR
1716 | ELF_LINK_HASH_DEF_REGULAR))
1718 if (! _bfd_elf_link_record_dynamic_symbol (info,
1719 hi))
1720 goto error_return;
1724 /* Now set HI to H, so that the following code
1725 will set the other fields correctly. */
1726 hi = h;
1729 /* If there is a duplicate definition somewhere,
1730 then HI may not point to an indirect symbol. We
1731 will have reported an error to the user in that
1732 case. */
1734 if (hi->root.type == bfd_link_hash_indirect)
1736 struct elf_link_hash_entry *ht;
1738 /* If the symbol became indirect, then we assume
1739 that we have not seen a definition before. */
1740 BFD_ASSERT ((hi->elf_link_hash_flags
1741 & (ELF_LINK_HASH_DEF_DYNAMIC
1742 | ELF_LINK_HASH_DEF_REGULAR))
1743 == 0);
1745 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1746 (*bed->elf_backend_copy_indirect_symbol) (ht, hi);
1748 /* See if the new flags lead us to realize that
1749 the symbol must be dynamic. */
1750 if (! dynsym)
1752 if (! dynamic)
1754 if (info->shared
1755 || ((hi->elf_link_hash_flags
1756 & ELF_LINK_HASH_REF_DYNAMIC)
1757 != 0))
1758 dynsym = true;
1760 else
1762 if ((hi->elf_link_hash_flags
1763 & ELF_LINK_HASH_REF_REGULAR) != 0)
1764 dynsym = true;
1769 /* We also need to define an indirection from the
1770 nondefault version of the symbol. */
1772 shortname = bfd_hash_allocate (&info->hash->table,
1773 strlen (name));
1774 if (shortname == NULL)
1775 goto error_return;
1776 strncpy (shortname, name, p - name);
1777 strcpy (shortname + (p - name), p + 1);
1779 /* Once again, merge with any existing symbol. */
1780 type_change_ok = false;
1781 size_change_ok = false;
1782 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1783 &value, &hi, &override,
1784 &type_change_ok, &size_change_ok))
1785 goto error_return;
1787 if (override)
1789 /* Here SHORTNAME is a versioned name, so we
1790 don't expect to see the type of override we
1791 do in the case above. */
1792 (*_bfd_error_handler)
1793 (_("%s: warning: unexpected redefinition of `%s'"),
1794 bfd_get_filename (abfd), shortname);
1796 else
1798 if (! (_bfd_generic_link_add_one_symbol
1799 (info, abfd, shortname, BSF_INDIRECT,
1800 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1801 collect, (struct bfd_link_hash_entry **) &hi)))
1802 goto error_return;
1804 /* If there is a duplicate definition somewhere,
1805 then HI may not point to an indirect symbol.
1806 We will have reported an error to the user in
1807 that case. */
1809 if (hi->root.type == bfd_link_hash_indirect)
1811 /* If the symbol became indirect, then we
1812 assume that we have not seen a definition
1813 before. */
1814 BFD_ASSERT ((hi->elf_link_hash_flags
1815 & (ELF_LINK_HASH_DEF_DYNAMIC
1816 | ELF_LINK_HASH_DEF_REGULAR))
1817 == 0);
1819 (*bed->elf_backend_copy_indirect_symbol) (h, hi);
1821 /* See if the new flags lead us to realize
1822 that the symbol must be dynamic. */
1823 if (! dynsym)
1825 if (! dynamic)
1827 if (info->shared
1828 || ((hi->elf_link_hash_flags
1829 & ELF_LINK_HASH_REF_DYNAMIC)
1830 != 0))
1831 dynsym = true;
1833 else
1835 if ((hi->elf_link_hash_flags
1836 & ELF_LINK_HASH_REF_REGULAR) != 0)
1837 dynsym = true;
1845 if (dynsym && h->dynindx == -1)
1847 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1848 goto error_return;
1849 if (h->weakdef != NULL
1850 && ! new_weakdef
1851 && h->weakdef->dynindx == -1)
1853 if (! _bfd_elf_link_record_dynamic_symbol (info,
1854 h->weakdef))
1855 goto error_return;
1858 else if (dynsym && h->dynindx != -1 && visibility_changed)
1859 /* If the symbol already has a dynamic index, but
1860 visibility says it should not be visible, turn it into
1861 a local symbol. */
1862 switch (ELF_ST_VISIBILITY (h->other))
1864 case STV_INTERNAL:
1865 case STV_HIDDEN:
1866 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
1867 (*bed->elf_backend_hide_symbol) (h);
1868 break;
1873 /* Now set the weakdefs field correctly for all the weak defined
1874 symbols we found. The only way to do this is to search all the
1875 symbols. Since we only need the information for non functions in
1876 dynamic objects, that's the only time we actually put anything on
1877 the list WEAKS. We need this information so that if a regular
1878 object refers to a symbol defined weakly in a dynamic object, the
1879 real symbol in the dynamic object is also put in the dynamic
1880 symbols; we also must arrange for both symbols to point to the
1881 same memory location. We could handle the general case of symbol
1882 aliasing, but a general symbol alias can only be generated in
1883 assembler code, handling it correctly would be very time
1884 consuming, and other ELF linkers don't handle general aliasing
1885 either. */
1886 while (weaks != NULL)
1888 struct elf_link_hash_entry *hlook;
1889 asection *slook;
1890 bfd_vma vlook;
1891 struct elf_link_hash_entry **hpp;
1892 struct elf_link_hash_entry **hppend;
1894 hlook = weaks;
1895 weaks = hlook->weakdef;
1896 hlook->weakdef = NULL;
1898 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
1899 || hlook->root.type == bfd_link_hash_defweak
1900 || hlook->root.type == bfd_link_hash_common
1901 || hlook->root.type == bfd_link_hash_indirect);
1902 slook = hlook->root.u.def.section;
1903 vlook = hlook->root.u.def.value;
1905 hpp = elf_sym_hashes (abfd);
1906 hppend = hpp + extsymcount;
1907 for (; hpp < hppend; hpp++)
1909 struct elf_link_hash_entry *h;
1911 h = *hpp;
1912 if (h != NULL && h != hlook
1913 && h->root.type == bfd_link_hash_defined
1914 && h->root.u.def.section == slook
1915 && h->root.u.def.value == vlook)
1917 hlook->weakdef = h;
1919 /* If the weak definition is in the list of dynamic
1920 symbols, make sure the real definition is put there
1921 as well. */
1922 if (hlook->dynindx != -1
1923 && h->dynindx == -1)
1925 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1926 goto error_return;
1929 /* If the real definition is in the list of dynamic
1930 symbols, make sure the weak definition is put there
1931 as well. If we don't do this, then the dynamic
1932 loader might not merge the entries for the real
1933 definition and the weak definition. */
1934 if (h->dynindx != -1
1935 && hlook->dynindx == -1)
1937 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
1938 goto error_return;
1941 break;
1946 if (buf != NULL)
1948 free (buf);
1949 buf = NULL;
1952 if (extversym != NULL)
1954 free (extversym);
1955 extversym = NULL;
1958 /* If this object is the same format as the output object, and it is
1959 not a shared library, then let the backend look through the
1960 relocs.
1962 This is required to build global offset table entries and to
1963 arrange for dynamic relocs. It is not required for the
1964 particular common case of linking non PIC code, even when linking
1965 against shared libraries, but unfortunately there is no way of
1966 knowing whether an object file has been compiled PIC or not.
1967 Looking through the relocs is not particularly time consuming.
1968 The problem is that we must either (1) keep the relocs in memory,
1969 which causes the linker to require additional runtime memory or
1970 (2) read the relocs twice from the input file, which wastes time.
1971 This would be a good case for using mmap.
1973 I have no idea how to handle linking PIC code into a file of a
1974 different format. It probably can't be done. */
1975 check_relocs = get_elf_backend_data (abfd)->check_relocs;
1976 if (! dynamic
1977 && abfd->xvec == info->hash->creator
1978 && check_relocs != NULL)
1980 asection *o;
1982 for (o = abfd->sections; o != NULL; o = o->next)
1984 Elf_Internal_Rela *internal_relocs;
1985 boolean ok;
1987 if ((o->flags & SEC_RELOC) == 0
1988 || o->reloc_count == 0
1989 || ((info->strip == strip_all || info->strip == strip_debugger)
1990 && (o->flags & SEC_DEBUGGING) != 0)
1991 || bfd_is_abs_section (o->output_section))
1992 continue;
1994 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
1995 (abfd, o, (PTR) NULL,
1996 (Elf_Internal_Rela *) NULL,
1997 info->keep_memory));
1998 if (internal_relocs == NULL)
1999 goto error_return;
2001 ok = (*check_relocs) (abfd, info, o, internal_relocs);
2003 if (! info->keep_memory)
2004 free (internal_relocs);
2006 if (! ok)
2007 goto error_return;
2011 /* If this is a non-traditional, non-relocateable link, try to
2012 optimize the handling of the .stab/.stabstr sections. */
2013 if (! dynamic
2014 && ! info->relocateable
2015 && ! info->traditional_format
2016 && info->hash->creator->flavour == bfd_target_elf_flavour
2017 && (info->strip != strip_all && info->strip != strip_debugger))
2019 asection *stab, *stabstr;
2021 stab = bfd_get_section_by_name (abfd, ".stab");
2022 if (stab != NULL)
2024 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
2026 if (stabstr != NULL)
2028 struct bfd_elf_section_data *secdata;
2030 secdata = elf_section_data (stab);
2031 if (! _bfd_link_section_stabs (abfd,
2032 &elf_hash_table (info)->stab_info,
2033 stab, stabstr,
2034 &secdata->stab_info))
2035 goto error_return;
2040 return true;
2042 error_return:
2043 if (buf != NULL)
2044 free (buf);
2045 if (dynbuf != NULL)
2046 free (dynbuf);
2047 if (dynver != NULL)
2048 free (dynver);
2049 if (extversym != NULL)
2050 free (extversym);
2051 return false;
2054 /* Create some sections which will be filled in with dynamic linking
2055 information. ABFD is an input file which requires dynamic sections
2056 to be created. The dynamic sections take up virtual memory space
2057 when the final executable is run, so we need to create them before
2058 addresses are assigned to the output sections. We work out the
2059 actual contents and size of these sections later. */
2061 boolean
2062 elf_link_create_dynamic_sections (abfd, info)
2063 bfd *abfd;
2064 struct bfd_link_info *info;
2066 flagword flags;
2067 register asection *s;
2068 struct elf_link_hash_entry *h;
2069 struct elf_backend_data *bed;
2071 if (elf_hash_table (info)->dynamic_sections_created)
2072 return true;
2074 /* Make sure that all dynamic sections use the same input BFD. */
2075 if (elf_hash_table (info)->dynobj == NULL)
2076 elf_hash_table (info)->dynobj = abfd;
2077 else
2078 abfd = elf_hash_table (info)->dynobj;
2080 /* Note that we set the SEC_IN_MEMORY flag for all of these
2081 sections. */
2082 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
2083 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2085 /* A dynamically linked executable has a .interp section, but a
2086 shared library does not. */
2087 if (! info->shared)
2089 s = bfd_make_section (abfd, ".interp");
2090 if (s == NULL
2091 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2092 return false;
2095 /* Create sections to hold version informations. These are removed
2096 if they are not needed. */
2097 s = bfd_make_section (abfd, ".gnu.version_d");
2098 if (s == NULL
2099 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2100 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2101 return false;
2103 s = bfd_make_section (abfd, ".gnu.version");
2104 if (s == NULL
2105 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2106 || ! bfd_set_section_alignment (abfd, s, 1))
2107 return false;
2109 s = bfd_make_section (abfd, ".gnu.version_r");
2110 if (s == NULL
2111 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2112 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2113 return false;
2115 s = bfd_make_section (abfd, ".dynsym");
2116 if (s == NULL
2117 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2118 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2119 return false;
2121 s = bfd_make_section (abfd, ".dynstr");
2122 if (s == NULL
2123 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2124 return false;
2126 /* Create a strtab to hold the dynamic symbol names. */
2127 if (elf_hash_table (info)->dynstr == NULL)
2129 elf_hash_table (info)->dynstr = elf_stringtab_init ();
2130 if (elf_hash_table (info)->dynstr == NULL)
2131 return false;
2134 s = bfd_make_section (abfd, ".dynamic");
2135 if (s == NULL
2136 || ! bfd_set_section_flags (abfd, s, flags)
2137 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2138 return false;
2140 /* The special symbol _DYNAMIC is always set to the start of the
2141 .dynamic section. This call occurs before we have processed the
2142 symbols for any dynamic object, so we don't have to worry about
2143 overriding a dynamic definition. We could set _DYNAMIC in a
2144 linker script, but we only want to define it if we are, in fact,
2145 creating a .dynamic section. We don't want to define it if there
2146 is no .dynamic section, since on some ELF platforms the start up
2147 code examines it to decide how to initialize the process. */
2148 h = NULL;
2149 if (! (_bfd_generic_link_add_one_symbol
2150 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
2151 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
2152 (struct bfd_link_hash_entry **) &h)))
2153 return false;
2154 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2155 h->type = STT_OBJECT;
2157 if (info->shared
2158 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
2159 return false;
2161 bed = get_elf_backend_data (abfd);
2163 s = bfd_make_section (abfd, ".hash");
2164 if (s == NULL
2165 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2166 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2167 return false;
2168 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
2170 /* Let the backend create the rest of the sections. This lets the
2171 backend set the right flags. The backend will normally create
2172 the .got and .plt sections. */
2173 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
2174 return false;
2176 elf_hash_table (info)->dynamic_sections_created = true;
2178 return true;
2181 /* Add an entry to the .dynamic table. */
2183 boolean
2184 elf_add_dynamic_entry (info, tag, val)
2185 struct bfd_link_info *info;
2186 bfd_vma tag;
2187 bfd_vma val;
2189 Elf_Internal_Dyn dyn;
2190 bfd *dynobj;
2191 asection *s;
2192 size_t newsize;
2193 bfd_byte *newcontents;
2195 dynobj = elf_hash_table (info)->dynobj;
2197 s = bfd_get_section_by_name (dynobj, ".dynamic");
2198 BFD_ASSERT (s != NULL);
2200 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
2201 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
2202 if (newcontents == NULL)
2203 return false;
2205 dyn.d_tag = tag;
2206 dyn.d_un.d_val = val;
2207 elf_swap_dyn_out (dynobj, &dyn,
2208 (Elf_External_Dyn *) (newcontents + s->_raw_size));
2210 s->_raw_size = newsize;
2211 s->contents = newcontents;
2213 return true;
2216 /* Record a new local dynamic symbol. */
2218 boolean
2219 elf_link_record_local_dynamic_symbol (info, input_bfd, input_indx)
2220 struct bfd_link_info *info;
2221 bfd *input_bfd;
2222 long input_indx;
2224 struct elf_link_local_dynamic_entry *entry;
2225 struct elf_link_hash_table *eht;
2226 struct bfd_strtab_hash *dynstr;
2227 Elf_External_Sym esym;
2228 unsigned long dynstr_index;
2229 char *name;
2231 /* See if the entry exists already. */
2232 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
2233 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
2234 return true;
2236 entry = (struct elf_link_local_dynamic_entry *)
2237 bfd_alloc (input_bfd, sizeof (*entry));
2238 if (entry == NULL)
2239 return false;
2241 /* Go find the symbol, so that we can find it's name. */
2242 if (bfd_seek (input_bfd,
2243 (elf_tdata (input_bfd)->symtab_hdr.sh_offset
2244 + input_indx * sizeof (Elf_External_Sym)),
2245 SEEK_SET) != 0
2246 || (bfd_read (&esym, sizeof (Elf_External_Sym), 1, input_bfd)
2247 != sizeof (Elf_External_Sym)))
2248 return false;
2249 elf_swap_symbol_in (input_bfd, &esym, &entry->isym);
2251 name = (bfd_elf_string_from_elf_section
2252 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
2253 entry->isym.st_name));
2255 dynstr = elf_hash_table (info)->dynstr;
2256 if (dynstr == NULL)
2258 /* Create a strtab to hold the dynamic symbol names. */
2259 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_stringtab_init ();
2260 if (dynstr == NULL)
2261 return false;
2264 dynstr_index = _bfd_stringtab_add (dynstr, name, true, false);
2265 if (dynstr_index == (unsigned long) -1)
2266 return false;
2267 entry->isym.st_name = dynstr_index;
2269 eht = elf_hash_table (info);
2271 entry->next = eht->dynlocal;
2272 eht->dynlocal = entry;
2273 entry->input_bfd = input_bfd;
2274 entry->input_indx = input_indx;
2275 eht->dynsymcount++;
2277 /* Whatever binding the symbol had before, it's now local. */
2278 entry->isym.st_info
2279 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
2281 /* The dynindx will be set at the end of size_dynamic_sections. */
2283 return true;
2287 /* Read and swap the relocs from the section indicated by SHDR. This
2288 may be either a REL or a RELA section. The relocations are
2289 translated into RELA relocations and stored in INTERNAL_RELOCS,
2290 which should have already been allocated to contain enough space.
2291 The EXTERNAL_RELOCS are a buffer where the external form of the
2292 relocations should be stored.
2294 Returns false if something goes wrong. */
2296 static boolean
2297 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2298 internal_relocs)
2299 bfd *abfd;
2300 Elf_Internal_Shdr *shdr;
2301 PTR external_relocs;
2302 Elf_Internal_Rela *internal_relocs;
2304 struct elf_backend_data *bed;
2306 /* If there aren't any relocations, that's OK. */
2307 if (!shdr)
2308 return true;
2310 /* Position ourselves at the start of the section. */
2311 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2312 return false;
2314 /* Read the relocations. */
2315 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2316 != shdr->sh_size)
2317 return false;
2319 bed = get_elf_backend_data (abfd);
2321 /* Convert the external relocations to the internal format. */
2322 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2324 Elf_External_Rel *erel;
2325 Elf_External_Rel *erelend;
2326 Elf_Internal_Rela *irela;
2327 Elf_Internal_Rel *irel;
2329 erel = (Elf_External_Rel *) external_relocs;
2330 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2331 irela = internal_relocs;
2332 irel = bfd_alloc (abfd, (bed->s->int_rels_per_ext_rel
2333 * sizeof (Elf_Internal_Rel)));
2334 for (; erel < erelend; erel++, irela += bed->s->int_rels_per_ext_rel)
2336 unsigned char i;
2338 if (bed->s->swap_reloc_in)
2339 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, irel);
2340 else
2341 elf_swap_reloc_in (abfd, erel, irel);
2343 for (i = 0; i < bed->s->int_rels_per_ext_rel; ++i)
2345 irela[i].r_offset = irel[i].r_offset;
2346 irela[i].r_info = irel[i].r_info;
2347 irela[i].r_addend = 0;
2351 else
2353 Elf_External_Rela *erela;
2354 Elf_External_Rela *erelaend;
2355 Elf_Internal_Rela *irela;
2357 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2359 erela = (Elf_External_Rela *) external_relocs;
2360 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2361 irela = internal_relocs;
2362 for (; erela < erelaend; erela++, irela += bed->s->int_rels_per_ext_rel)
2364 if (bed->s->swap_reloca_in)
2365 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, irela);
2366 else
2367 elf_swap_reloca_in (abfd, erela, irela);
2371 return true;
2374 /* Read and swap the relocs for a section O. They may have been
2375 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2376 not NULL, they are used as buffers to read into. They are known to
2377 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
2378 the return value is allocated using either malloc or bfd_alloc,
2379 according to the KEEP_MEMORY argument. If O has two relocation
2380 sections (both REL and RELA relocations), then the REL_HDR
2381 relocations will appear first in INTERNAL_RELOCS, followed by the
2382 REL_HDR2 relocations. */
2384 Elf_Internal_Rela *
2385 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2386 keep_memory)
2387 bfd *abfd;
2388 asection *o;
2389 PTR external_relocs;
2390 Elf_Internal_Rela *internal_relocs;
2391 boolean keep_memory;
2393 Elf_Internal_Shdr *rel_hdr;
2394 PTR alloc1 = NULL;
2395 Elf_Internal_Rela *alloc2 = NULL;
2396 struct elf_backend_data *bed = get_elf_backend_data (abfd);
2398 if (elf_section_data (o)->relocs != NULL)
2399 return elf_section_data (o)->relocs;
2401 if (o->reloc_count == 0)
2402 return NULL;
2404 rel_hdr = &elf_section_data (o)->rel_hdr;
2406 if (internal_relocs == NULL)
2408 size_t size;
2410 size = (o->reloc_count * bed->s->int_rels_per_ext_rel
2411 * sizeof (Elf_Internal_Rela));
2412 if (keep_memory)
2413 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2414 else
2415 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2416 if (internal_relocs == NULL)
2417 goto error_return;
2420 if (external_relocs == NULL)
2422 size_t size = (size_t) rel_hdr->sh_size;
2424 if (elf_section_data (o)->rel_hdr2)
2425 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2426 alloc1 = (PTR) bfd_malloc (size);
2427 if (alloc1 == NULL)
2428 goto error_return;
2429 external_relocs = alloc1;
2432 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2433 external_relocs,
2434 internal_relocs))
2435 goto error_return;
2436 if (!elf_link_read_relocs_from_section
2437 (abfd,
2438 elf_section_data (o)->rel_hdr2,
2439 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
2440 internal_relocs + (rel_hdr->sh_size / rel_hdr->sh_entsize
2441 * bed->s->int_rels_per_ext_rel)))
2442 goto error_return;
2444 /* Cache the results for next time, if we can. */
2445 if (keep_memory)
2446 elf_section_data (o)->relocs = internal_relocs;
2448 if (alloc1 != NULL)
2449 free (alloc1);
2451 /* Don't free alloc2, since if it was allocated we are passing it
2452 back (under the name of internal_relocs). */
2454 return internal_relocs;
2456 error_return:
2457 if (alloc1 != NULL)
2458 free (alloc1);
2459 if (alloc2 != NULL)
2460 free (alloc2);
2461 return NULL;
2465 /* Record an assignment to a symbol made by a linker script. We need
2466 this in case some dynamic object refers to this symbol. */
2468 /*ARGSUSED*/
2469 boolean
2470 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2471 bfd *output_bfd ATTRIBUTE_UNUSED;
2472 struct bfd_link_info *info;
2473 const char *name;
2474 boolean provide;
2476 struct elf_link_hash_entry *h;
2478 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2479 return true;
2481 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2482 if (h == NULL)
2483 return false;
2485 if (h->root.type == bfd_link_hash_new)
2486 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2488 /* If this symbol is being provided by the linker script, and it is
2489 currently defined by a dynamic object, but not by a regular
2490 object, then mark it as undefined so that the generic linker will
2491 force the correct value. */
2492 if (provide
2493 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2494 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2495 h->root.type = bfd_link_hash_undefined;
2497 /* If this symbol is not being provided by the linker script, and it is
2498 currently defined by a dynamic object, but not by a regular object,
2499 then clear out any version information because the symbol will not be
2500 associated with the dynamic object any more. */
2501 if (!provide
2502 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2503 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2504 h->verinfo.verdef = NULL;
2506 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2508 /* When possible, keep the original type of the symbol */
2509 if (h->type == STT_NOTYPE)
2510 h->type = STT_OBJECT;
2512 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2513 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2514 || info->shared)
2515 && h->dynindx == -1)
2517 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2518 return false;
2520 /* If this is a weak defined symbol, and we know a corresponding
2521 real symbol from the same dynamic object, make sure the real
2522 symbol is also made into a dynamic symbol. */
2523 if (h->weakdef != NULL
2524 && h->weakdef->dynindx == -1)
2526 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2527 return false;
2531 return true;
2534 /* This structure is used to pass information to
2535 elf_link_assign_sym_version. */
2537 struct elf_assign_sym_version_info
2539 /* Output BFD. */
2540 bfd *output_bfd;
2541 /* General link information. */
2542 struct bfd_link_info *info;
2543 /* Version tree. */
2544 struct bfd_elf_version_tree *verdefs;
2545 /* Whether we are exporting all dynamic symbols. */
2546 boolean export_dynamic;
2547 /* Whether we had a failure. */
2548 boolean failed;
2551 /* This structure is used to pass information to
2552 elf_link_find_version_dependencies. */
2554 struct elf_find_verdep_info
2556 /* Output BFD. */
2557 bfd *output_bfd;
2558 /* General link information. */
2559 struct bfd_link_info *info;
2560 /* The number of dependencies. */
2561 unsigned int vers;
2562 /* Whether we had a failure. */
2563 boolean failed;
2566 /* Array used to determine the number of hash table buckets to use
2567 based on the number of symbols there are. If there are fewer than
2568 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2569 fewer than 37 we use 17 buckets, and so forth. We never use more
2570 than 32771 buckets. */
2572 static const size_t elf_buckets[] =
2574 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2575 16411, 32771, 0
2578 /* Compute bucket count for hashing table. We do not use a static set
2579 of possible tables sizes anymore. Instead we determine for all
2580 possible reasonable sizes of the table the outcome (i.e., the
2581 number of collisions etc) and choose the best solution. The
2582 weighting functions are not too simple to allow the table to grow
2583 without bounds. Instead one of the weighting factors is the size.
2584 Therefore the result is always a good payoff between few collisions
2585 (= short chain lengths) and table size. */
2586 static size_t
2587 compute_bucket_count (info)
2588 struct bfd_link_info *info;
2590 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2591 size_t best_size = 0;
2592 unsigned long int *hashcodes;
2593 unsigned long int *hashcodesp;
2594 unsigned long int i;
2596 /* Compute the hash values for all exported symbols. At the same
2597 time store the values in an array so that we could use them for
2598 optimizations. */
2599 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2600 * sizeof (unsigned long int));
2601 if (hashcodes == NULL)
2602 return 0;
2603 hashcodesp = hashcodes;
2605 /* Put all hash values in HASHCODES. */
2606 elf_link_hash_traverse (elf_hash_table (info),
2607 elf_collect_hash_codes, &hashcodesp);
2609 /* We have a problem here. The following code to optimize the table
2610 size requires an integer type with more the 32 bits. If
2611 BFD_HOST_U_64_BIT is set we know about such a type. */
2612 #ifdef BFD_HOST_U_64_BIT
2613 if (info->optimize == true)
2615 unsigned long int nsyms = hashcodesp - hashcodes;
2616 size_t minsize;
2617 size_t maxsize;
2618 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2619 unsigned long int *counts ;
2621 /* Possible optimization parameters: if we have NSYMS symbols we say
2622 that the hashing table must at least have NSYMS/4 and at most
2623 2*NSYMS buckets. */
2624 minsize = nsyms / 4;
2625 if (minsize == 0)
2626 minsize = 1;
2627 best_size = maxsize = nsyms * 2;
2629 /* Create array where we count the collisions in. We must use bfd_malloc
2630 since the size could be large. */
2631 counts = (unsigned long int *) bfd_malloc (maxsize
2632 * sizeof (unsigned long int));
2633 if (counts == NULL)
2635 free (hashcodes);
2636 return 0;
2639 /* Compute the "optimal" size for the hash table. The criteria is a
2640 minimal chain length. The minor criteria is (of course) the size
2641 of the table. */
2642 for (i = minsize; i < maxsize; ++i)
2644 /* Walk through the array of hashcodes and count the collisions. */
2645 BFD_HOST_U_64_BIT max;
2646 unsigned long int j;
2647 unsigned long int fact;
2649 memset (counts, '\0', i * sizeof (unsigned long int));
2651 /* Determine how often each hash bucket is used. */
2652 for (j = 0; j < nsyms; ++j)
2653 ++counts[hashcodes[j] % i];
2655 /* For the weight function we need some information about the
2656 pagesize on the target. This is information need not be 100%
2657 accurate. Since this information is not available (so far) we
2658 define it here to a reasonable default value. If it is crucial
2659 to have a better value some day simply define this value. */
2660 # ifndef BFD_TARGET_PAGESIZE
2661 # define BFD_TARGET_PAGESIZE (4096)
2662 # endif
2664 /* We in any case need 2 + NSYMS entries for the size values and
2665 the chains. */
2666 max = (2 + nsyms) * (ARCH_SIZE / 8);
2668 # if 1
2669 /* Variant 1: optimize for short chains. We add the squares
2670 of all the chain lengths (which favous many small chain
2671 over a few long chains). */
2672 for (j = 0; j < i; ++j)
2673 max += counts[j] * counts[j];
2675 /* This adds penalties for the overall size of the table. */
2676 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2677 max *= fact * fact;
2678 # else
2679 /* Variant 2: Optimize a lot more for small table. Here we
2680 also add squares of the size but we also add penalties for
2681 empty slots (the +1 term). */
2682 for (j = 0; j < i; ++j)
2683 max += (1 + counts[j]) * (1 + counts[j]);
2685 /* The overall size of the table is considered, but not as
2686 strong as in variant 1, where it is squared. */
2687 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2688 max *= fact;
2689 # endif
2691 /* Compare with current best results. */
2692 if (max < best_chlen)
2694 best_chlen = max;
2695 best_size = i;
2699 free (counts);
2701 else
2702 #endif /* defined (BFD_HOST_U_64_BIT) */
2704 /* This is the fallback solution if no 64bit type is available or if we
2705 are not supposed to spend much time on optimizations. We select the
2706 bucket count using a fixed set of numbers. */
2707 for (i = 0; elf_buckets[i] != 0; i++)
2709 best_size = elf_buckets[i];
2710 if (dynsymcount < elf_buckets[i + 1])
2711 break;
2715 /* Free the arrays we needed. */
2716 free (hashcodes);
2718 return best_size;
2721 /* Set up the sizes and contents of the ELF dynamic sections. This is
2722 called by the ELF linker emulation before_allocation routine. We
2723 must set the sizes of the sections before the linker sets the
2724 addresses of the various sections. */
2726 boolean
2727 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2728 export_dynamic, filter_shlib,
2729 auxiliary_filters, info, sinterpptr,
2730 verdefs)
2731 bfd *output_bfd;
2732 const char *soname;
2733 const char *rpath;
2734 boolean export_dynamic;
2735 const char *filter_shlib;
2736 const char * const *auxiliary_filters;
2737 struct bfd_link_info *info;
2738 asection **sinterpptr;
2739 struct bfd_elf_version_tree *verdefs;
2741 bfd_size_type soname_indx;
2742 bfd *dynobj;
2743 struct elf_backend_data *bed;
2744 struct elf_assign_sym_version_info asvinfo;
2746 *sinterpptr = NULL;
2748 soname_indx = (bfd_size_type) -1;
2750 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2751 return true;
2753 /* The backend may have to create some sections regardless of whether
2754 we're dynamic or not. */
2755 bed = get_elf_backend_data (output_bfd);
2756 if (bed->elf_backend_always_size_sections
2757 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2758 return false;
2760 dynobj = elf_hash_table (info)->dynobj;
2762 /* If there were no dynamic objects in the link, there is nothing to
2763 do here. */
2764 if (dynobj == NULL)
2765 return true;
2767 if (elf_hash_table (info)->dynamic_sections_created)
2769 struct elf_info_failed eif;
2770 struct elf_link_hash_entry *h;
2771 bfd_size_type strsize;
2773 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2774 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2776 if (soname != NULL)
2778 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2779 soname, true, true);
2780 if (soname_indx == (bfd_size_type) -1
2781 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2782 return false;
2785 if (info->symbolic)
2787 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2788 return false;
2791 if (rpath != NULL)
2793 bfd_size_type indx;
2795 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2796 true, true);
2797 if (indx == (bfd_size_type) -1
2798 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
2799 return false;
2802 if (filter_shlib != NULL)
2804 bfd_size_type indx;
2806 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2807 filter_shlib, true, true);
2808 if (indx == (bfd_size_type) -1
2809 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2810 return false;
2813 if (auxiliary_filters != NULL)
2815 const char * const *p;
2817 for (p = auxiliary_filters; *p != NULL; p++)
2819 bfd_size_type indx;
2821 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2822 *p, true, true);
2823 if (indx == (bfd_size_type) -1
2824 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2825 return false;
2829 /* If we are supposed to export all symbols into the dynamic symbol
2830 table (this is not the normal case), then do so. */
2831 if (export_dynamic)
2833 struct elf_info_failed eif;
2835 eif.failed = false;
2836 eif.info = info;
2837 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2838 (PTR) &eif);
2839 if (eif.failed)
2840 return false;
2843 /* Attach all the symbols to their version information. */
2844 asvinfo.output_bfd = output_bfd;
2845 asvinfo.info = info;
2846 asvinfo.verdefs = verdefs;
2847 asvinfo.export_dynamic = export_dynamic;
2848 asvinfo.failed = false;
2850 elf_link_hash_traverse (elf_hash_table (info),
2851 elf_link_assign_sym_version,
2852 (PTR) &asvinfo);
2853 if (asvinfo.failed)
2854 return false;
2856 /* Find all symbols which were defined in a dynamic object and make
2857 the backend pick a reasonable value for them. */
2858 eif.failed = false;
2859 eif.info = info;
2860 elf_link_hash_traverse (elf_hash_table (info),
2861 elf_adjust_dynamic_symbol,
2862 (PTR) &eif);
2863 if (eif.failed)
2864 return false;
2866 /* Add some entries to the .dynamic section. We fill in some of the
2867 values later, in elf_bfd_final_link, but we must add the entries
2868 now so that we know the final size of the .dynamic section. */
2870 /* If there are initialization and/or finalization functions to
2871 call then add the corresponding DT_INIT/DT_FINI entries. */
2872 h = (info->init_function
2873 ? elf_link_hash_lookup (elf_hash_table (info),
2874 info->init_function, false,
2875 false, false)
2876 : NULL);
2877 if (h != NULL
2878 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2879 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2881 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2882 return false;
2884 h = (info->fini_function
2885 ? elf_link_hash_lookup (elf_hash_table (info),
2886 info->fini_function, false,
2887 false, false)
2888 : NULL);
2889 if (h != NULL
2890 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2891 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2893 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2894 return false;
2897 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2898 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2899 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2900 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2901 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2902 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2903 sizeof (Elf_External_Sym)))
2904 return false;
2907 /* The backend must work out the sizes of all the other dynamic
2908 sections. */
2909 if (bed->elf_backend_size_dynamic_sections
2910 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2911 return false;
2913 if (elf_hash_table (info)->dynamic_sections_created)
2915 size_t dynsymcount;
2916 asection *s;
2917 size_t bucketcount = 0;
2918 Elf_Internal_Sym isym;
2919 size_t hash_entry_size;
2921 /* Set up the version definition section. */
2922 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2923 BFD_ASSERT (s != NULL);
2925 /* We may have created additional version definitions if we are
2926 just linking a regular application. */
2927 verdefs = asvinfo.verdefs;
2929 if (verdefs == NULL)
2930 _bfd_strip_section_from_output (info, s);
2931 else
2933 unsigned int cdefs;
2934 bfd_size_type size;
2935 struct bfd_elf_version_tree *t;
2936 bfd_byte *p;
2937 Elf_Internal_Verdef def;
2938 Elf_Internal_Verdaux defaux;
2940 cdefs = 0;
2941 size = 0;
2943 /* Make space for the base version. */
2944 size += sizeof (Elf_External_Verdef);
2945 size += sizeof (Elf_External_Verdaux);
2946 ++cdefs;
2948 for (t = verdefs; t != NULL; t = t->next)
2950 struct bfd_elf_version_deps *n;
2952 size += sizeof (Elf_External_Verdef);
2953 size += sizeof (Elf_External_Verdaux);
2954 ++cdefs;
2956 for (n = t->deps; n != NULL; n = n->next)
2957 size += sizeof (Elf_External_Verdaux);
2960 s->_raw_size = size;
2961 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
2962 if (s->contents == NULL && s->_raw_size != 0)
2963 return false;
2965 /* Fill in the version definition section. */
2967 p = s->contents;
2969 def.vd_version = VER_DEF_CURRENT;
2970 def.vd_flags = VER_FLG_BASE;
2971 def.vd_ndx = 1;
2972 def.vd_cnt = 1;
2973 def.vd_aux = sizeof (Elf_External_Verdef);
2974 def.vd_next = (sizeof (Elf_External_Verdef)
2975 + sizeof (Elf_External_Verdaux));
2977 if (soname_indx != (bfd_size_type) -1)
2979 def.vd_hash = bfd_elf_hash (soname);
2980 defaux.vda_name = soname_indx;
2982 else
2984 const char *name;
2985 bfd_size_type indx;
2987 name = output_bfd->filename;
2988 def.vd_hash = bfd_elf_hash (name);
2989 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2990 name, true, false);
2991 if (indx == (bfd_size_type) -1)
2992 return false;
2993 defaux.vda_name = indx;
2995 defaux.vda_next = 0;
2997 _bfd_elf_swap_verdef_out (output_bfd, &def,
2998 (Elf_External_Verdef *)p);
2999 p += sizeof (Elf_External_Verdef);
3000 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3001 (Elf_External_Verdaux *) p);
3002 p += sizeof (Elf_External_Verdaux);
3004 for (t = verdefs; t != NULL; t = t->next)
3006 unsigned int cdeps;
3007 struct bfd_elf_version_deps *n;
3008 struct elf_link_hash_entry *h;
3010 cdeps = 0;
3011 for (n = t->deps; n != NULL; n = n->next)
3012 ++cdeps;
3014 /* Add a symbol representing this version. */
3015 h = NULL;
3016 if (! (_bfd_generic_link_add_one_symbol
3017 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3018 (bfd_vma) 0, (const char *) NULL, false,
3019 get_elf_backend_data (dynobj)->collect,
3020 (struct bfd_link_hash_entry **) &h)))
3021 return false;
3022 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3023 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3024 h->type = STT_OBJECT;
3025 h->verinfo.vertree = t;
3027 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3028 return false;
3030 def.vd_version = VER_DEF_CURRENT;
3031 def.vd_flags = 0;
3032 if (t->globals == NULL && t->locals == NULL && ! t->used)
3033 def.vd_flags |= VER_FLG_WEAK;
3034 def.vd_ndx = t->vernum + 1;
3035 def.vd_cnt = cdeps + 1;
3036 def.vd_hash = bfd_elf_hash (t->name);
3037 def.vd_aux = sizeof (Elf_External_Verdef);
3038 if (t->next != NULL)
3039 def.vd_next = (sizeof (Elf_External_Verdef)
3040 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3041 else
3042 def.vd_next = 0;
3044 _bfd_elf_swap_verdef_out (output_bfd, &def,
3045 (Elf_External_Verdef *) p);
3046 p += sizeof (Elf_External_Verdef);
3048 defaux.vda_name = h->dynstr_index;
3049 if (t->deps == NULL)
3050 defaux.vda_next = 0;
3051 else
3052 defaux.vda_next = sizeof (Elf_External_Verdaux);
3053 t->name_indx = defaux.vda_name;
3055 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3056 (Elf_External_Verdaux *) p);
3057 p += sizeof (Elf_External_Verdaux);
3059 for (n = t->deps; n != NULL; n = n->next)
3061 if (n->version_needed == NULL)
3063 /* This can happen if there was an error in the
3064 version script. */
3065 defaux.vda_name = 0;
3067 else
3068 defaux.vda_name = n->version_needed->name_indx;
3069 if (n->next == NULL)
3070 defaux.vda_next = 0;
3071 else
3072 defaux.vda_next = sizeof (Elf_External_Verdaux);
3074 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3075 (Elf_External_Verdaux *) p);
3076 p += sizeof (Elf_External_Verdaux);
3080 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3081 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3082 return false;
3084 elf_tdata (output_bfd)->cverdefs = cdefs;
3087 /* Work out the size of the version reference section. */
3089 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3090 BFD_ASSERT (s != NULL);
3092 struct elf_find_verdep_info sinfo;
3094 sinfo.output_bfd = output_bfd;
3095 sinfo.info = info;
3096 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3097 if (sinfo.vers == 0)
3098 sinfo.vers = 1;
3099 sinfo.failed = false;
3101 elf_link_hash_traverse (elf_hash_table (info),
3102 elf_link_find_version_dependencies,
3103 (PTR) &sinfo);
3105 if (elf_tdata (output_bfd)->verref == NULL)
3106 _bfd_strip_section_from_output (info, s);
3107 else
3109 Elf_Internal_Verneed *t;
3110 unsigned int size;
3111 unsigned int crefs;
3112 bfd_byte *p;
3114 /* Build the version definition section. */
3115 size = 0;
3116 crefs = 0;
3117 for (t = elf_tdata (output_bfd)->verref;
3118 t != NULL;
3119 t = t->vn_nextref)
3121 Elf_Internal_Vernaux *a;
3123 size += sizeof (Elf_External_Verneed);
3124 ++crefs;
3125 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3126 size += sizeof (Elf_External_Vernaux);
3129 s->_raw_size = size;
3130 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3131 if (s->contents == NULL)
3132 return false;
3134 p = s->contents;
3135 for (t = elf_tdata (output_bfd)->verref;
3136 t != NULL;
3137 t = t->vn_nextref)
3139 unsigned int caux;
3140 Elf_Internal_Vernaux *a;
3141 bfd_size_type indx;
3143 caux = 0;
3144 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3145 ++caux;
3147 t->vn_version = VER_NEED_CURRENT;
3148 t->vn_cnt = caux;
3149 if (elf_dt_name (t->vn_bfd) != NULL)
3150 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3151 elf_dt_name (t->vn_bfd),
3152 true, false);
3153 else
3154 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3155 t->vn_bfd->filename, true, false);
3156 if (indx == (bfd_size_type) -1)
3157 return false;
3158 t->vn_file = indx;
3159 t->vn_aux = sizeof (Elf_External_Verneed);
3160 if (t->vn_nextref == NULL)
3161 t->vn_next = 0;
3162 else
3163 t->vn_next = (sizeof (Elf_External_Verneed)
3164 + caux * sizeof (Elf_External_Vernaux));
3166 _bfd_elf_swap_verneed_out (output_bfd, t,
3167 (Elf_External_Verneed *) p);
3168 p += sizeof (Elf_External_Verneed);
3170 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3172 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3173 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3174 a->vna_nodename, true, false);
3175 if (indx == (bfd_size_type) -1)
3176 return false;
3177 a->vna_name = indx;
3178 if (a->vna_nextptr == NULL)
3179 a->vna_next = 0;
3180 else
3181 a->vna_next = sizeof (Elf_External_Vernaux);
3183 _bfd_elf_swap_vernaux_out (output_bfd, a,
3184 (Elf_External_Vernaux *) p);
3185 p += sizeof (Elf_External_Vernaux);
3189 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3190 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3191 return false;
3193 elf_tdata (output_bfd)->cverrefs = crefs;
3197 /* Assign dynsym indicies. In a shared library we generate a
3198 section symbol for each output section, which come first.
3199 Next come all of the back-end allocated local dynamic syms,
3200 followed by the rest of the global symbols. */
3202 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3204 /* Work out the size of the symbol version section. */
3205 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3206 BFD_ASSERT (s != NULL);
3207 if (dynsymcount == 0
3208 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3210 _bfd_strip_section_from_output (info, s);
3211 /* The DYNSYMCOUNT might have changed if we were going to
3212 output a dynamic symbol table entry for S. */
3213 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3215 else
3217 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3218 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3219 if (s->contents == NULL)
3220 return false;
3222 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3223 return false;
3226 /* Set the size of the .dynsym and .hash sections. We counted
3227 the number of dynamic symbols in elf_link_add_object_symbols.
3228 We will build the contents of .dynsym and .hash when we build
3229 the final symbol table, because until then we do not know the
3230 correct value to give the symbols. We built the .dynstr
3231 section as we went along in elf_link_add_object_symbols. */
3232 s = bfd_get_section_by_name (dynobj, ".dynsym");
3233 BFD_ASSERT (s != NULL);
3234 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3235 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3236 if (s->contents == NULL && s->_raw_size != 0)
3237 return false;
3239 /* The first entry in .dynsym is a dummy symbol. */
3240 isym.st_value = 0;
3241 isym.st_size = 0;
3242 isym.st_name = 0;
3243 isym.st_info = 0;
3244 isym.st_other = 0;
3245 isym.st_shndx = 0;
3246 elf_swap_symbol_out (output_bfd, &isym,
3247 (PTR) (Elf_External_Sym *) s->contents);
3249 /* Compute the size of the hashing table. As a side effect this
3250 computes the hash values for all the names we export. */
3251 bucketcount = compute_bucket_count (info);
3253 s = bfd_get_section_by_name (dynobj, ".hash");
3254 BFD_ASSERT (s != NULL);
3255 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3256 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3257 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3258 if (s->contents == NULL)
3259 return false;
3260 memset (s->contents, 0, (size_t) s->_raw_size);
3262 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3263 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3264 s->contents + hash_entry_size);
3266 elf_hash_table (info)->bucketcount = bucketcount;
3268 s = bfd_get_section_by_name (dynobj, ".dynstr");
3269 BFD_ASSERT (s != NULL);
3270 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3272 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3273 return false;
3276 return true;
3279 /* Fix up the flags for a symbol. This handles various cases which
3280 can only be fixed after all the input files are seen. This is
3281 currently called by both adjust_dynamic_symbol and
3282 assign_sym_version, which is unnecessary but perhaps more robust in
3283 the face of future changes. */
3285 static boolean
3286 elf_fix_symbol_flags (h, eif)
3287 struct elf_link_hash_entry *h;
3288 struct elf_info_failed *eif;
3290 /* If this symbol was mentioned in a non-ELF file, try to set
3291 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3292 permit a non-ELF file to correctly refer to a symbol defined in
3293 an ELF dynamic object. */
3294 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3296 if (h->root.type != bfd_link_hash_defined
3297 && h->root.type != bfd_link_hash_defweak)
3298 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3299 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3300 else
3302 if (h->root.u.def.section->owner != NULL
3303 && (bfd_get_flavour (h->root.u.def.section->owner)
3304 == bfd_target_elf_flavour))
3305 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3306 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3307 else
3308 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3311 if (h->dynindx == -1
3312 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3313 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3315 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3317 eif->failed = true;
3318 return false;
3322 else
3324 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3325 was first seen in a non-ELF file. Fortunately, if the symbol
3326 was first seen in an ELF file, we're probably OK unless the
3327 symbol was defined in a non-ELF file. Catch that case here.
3328 FIXME: We're still in trouble if the symbol was first seen in
3329 a dynamic object, and then later in a non-ELF regular object. */
3330 if ((h->root.type == bfd_link_hash_defined
3331 || h->root.type == bfd_link_hash_defweak)
3332 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3333 && (h->root.u.def.section->owner != NULL
3334 ? (bfd_get_flavour (h->root.u.def.section->owner)
3335 != bfd_target_elf_flavour)
3336 : (bfd_is_abs_section (h->root.u.def.section)
3337 && (h->elf_link_hash_flags
3338 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3339 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3342 /* If this is a final link, and the symbol was defined as a common
3343 symbol in a regular object file, and there was no definition in
3344 any dynamic object, then the linker will have allocated space for
3345 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3346 flag will not have been set. */
3347 if (h->root.type == bfd_link_hash_defined
3348 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3349 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3350 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3351 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3352 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3354 /* If -Bsymbolic was used (which means to bind references to global
3355 symbols to the definition within the shared object), and this
3356 symbol was defined in a regular object, then it actually doesn't
3357 need a PLT entry. Likewise, if the symbol has any kind of
3358 visibility (internal, hidden, or protected), it doesn't need a
3359 PLT. */
3360 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3361 && eif->info->shared
3362 && (eif->info->symbolic || ELF_ST_VISIBILITY (h->other))
3363 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3365 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3366 h->plt.offset = (bfd_vma) -1;
3369 /* If this is a weak defined symbol in a dynamic object, and we know
3370 the real definition in the dynamic object, copy interesting flags
3371 over to the real definition. */
3372 if (h->weakdef != NULL)
3374 struct elf_link_hash_entry *weakdef;
3376 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3377 || h->root.type == bfd_link_hash_defweak);
3378 weakdef = h->weakdef;
3379 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3380 || weakdef->root.type == bfd_link_hash_defweak);
3381 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3383 /* If the real definition is defined by a regular object file,
3384 don't do anything special. See the longer description in
3385 elf_adjust_dynamic_symbol, below. */
3386 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3387 h->weakdef = NULL;
3388 else
3389 weakdef->elf_link_hash_flags |=
3390 (h->elf_link_hash_flags
3391 & (ELF_LINK_HASH_REF_REGULAR
3392 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3393 | ELF_LINK_NON_GOT_REF));
3396 return true;
3399 /* Make the backend pick a good value for a dynamic symbol. This is
3400 called via elf_link_hash_traverse, and also calls itself
3401 recursively. */
3403 static boolean
3404 elf_adjust_dynamic_symbol (h, data)
3405 struct elf_link_hash_entry *h;
3406 PTR data;
3408 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3409 bfd *dynobj;
3410 struct elf_backend_data *bed;
3412 /* Ignore indirect symbols. These are added by the versioning code. */
3413 if (h->root.type == bfd_link_hash_indirect)
3414 return true;
3416 /* Fix the symbol flags. */
3417 if (! elf_fix_symbol_flags (h, eif))
3418 return false;
3420 /* If this symbol does not require a PLT entry, and it is not
3421 defined by a dynamic object, or is not referenced by a regular
3422 object, ignore it. We do have to handle a weak defined symbol,
3423 even if no regular object refers to it, if we decided to add it
3424 to the dynamic symbol table. FIXME: Do we normally need to worry
3425 about symbols which are defined by one dynamic object and
3426 referenced by another one? */
3427 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3428 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3429 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3430 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3431 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3433 h->plt.offset = (bfd_vma) -1;
3434 return true;
3437 /* If we've already adjusted this symbol, don't do it again. This
3438 can happen via a recursive call. */
3439 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3440 return true;
3442 /* Don't look at this symbol again. Note that we must set this
3443 after checking the above conditions, because we may look at a
3444 symbol once, decide not to do anything, and then get called
3445 recursively later after REF_REGULAR is set below. */
3446 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3448 /* If this is a weak definition, and we know a real definition, and
3449 the real symbol is not itself defined by a regular object file,
3450 then get a good value for the real definition. We handle the
3451 real symbol first, for the convenience of the backend routine.
3453 Note that there is a confusing case here. If the real definition
3454 is defined by a regular object file, we don't get the real symbol
3455 from the dynamic object, but we do get the weak symbol. If the
3456 processor backend uses a COPY reloc, then if some routine in the
3457 dynamic object changes the real symbol, we will not see that
3458 change in the corresponding weak symbol. This is the way other
3459 ELF linkers work as well, and seems to be a result of the shared
3460 library model.
3462 I will clarify this issue. Most SVR4 shared libraries define the
3463 variable _timezone and define timezone as a weak synonym. The
3464 tzset call changes _timezone. If you write
3465 extern int timezone;
3466 int _timezone = 5;
3467 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3468 you might expect that, since timezone is a synonym for _timezone,
3469 the same number will print both times. However, if the processor
3470 backend uses a COPY reloc, then actually timezone will be copied
3471 into your process image, and, since you define _timezone
3472 yourself, _timezone will not. Thus timezone and _timezone will
3473 wind up at different memory locations. The tzset call will set
3474 _timezone, leaving timezone unchanged. */
3476 if (h->weakdef != NULL)
3478 /* If we get to this point, we know there is an implicit
3479 reference by a regular object file via the weak symbol H.
3480 FIXME: Is this really true? What if the traversal finds
3481 H->WEAKDEF before it finds H? */
3482 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3484 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3485 return false;
3488 /* If a symbol has no type and no size and does not require a PLT
3489 entry, then we are probably about to do the wrong thing here: we
3490 are probably going to create a COPY reloc for an empty object.
3491 This case can arise when a shared object is built with assembly
3492 code, and the assembly code fails to set the symbol type. */
3493 if (h->size == 0
3494 && h->type == STT_NOTYPE
3495 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3496 (*_bfd_error_handler)
3497 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3498 h->root.root.string);
3500 dynobj = elf_hash_table (eif->info)->dynobj;
3501 bed = get_elf_backend_data (dynobj);
3502 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3504 eif->failed = true;
3505 return false;
3508 return true;
3511 /* This routine is used to export all defined symbols into the dynamic
3512 symbol table. It is called via elf_link_hash_traverse. */
3514 static boolean
3515 elf_export_symbol (h, data)
3516 struct elf_link_hash_entry *h;
3517 PTR data;
3519 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3521 /* Ignore indirect symbols. These are added by the versioning code. */
3522 if (h->root.type == bfd_link_hash_indirect)
3523 return true;
3525 if (h->dynindx == -1
3526 && (h->elf_link_hash_flags
3527 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3529 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3531 eif->failed = true;
3532 return false;
3536 return true;
3539 /* Look through the symbols which are defined in other shared
3540 libraries and referenced here. Update the list of version
3541 dependencies. This will be put into the .gnu.version_r section.
3542 This function is called via elf_link_hash_traverse. */
3544 static boolean
3545 elf_link_find_version_dependencies (h, data)
3546 struct elf_link_hash_entry *h;
3547 PTR data;
3549 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3550 Elf_Internal_Verneed *t;
3551 Elf_Internal_Vernaux *a;
3553 /* We only care about symbols defined in shared objects with version
3554 information. */
3555 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3556 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3557 || h->dynindx == -1
3558 || h->verinfo.verdef == NULL)
3559 return true;
3561 /* See if we already know about this version. */
3562 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3564 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3565 continue;
3567 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3568 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3569 return true;
3571 break;
3574 /* This is a new version. Add it to tree we are building. */
3576 if (t == NULL)
3578 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3579 if (t == NULL)
3581 rinfo->failed = true;
3582 return false;
3585 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3586 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3587 elf_tdata (rinfo->output_bfd)->verref = t;
3590 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3592 /* Note that we are copying a string pointer here, and testing it
3593 above. If bfd_elf_string_from_elf_section is ever changed to
3594 discard the string data when low in memory, this will have to be
3595 fixed. */
3596 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3598 a->vna_flags = h->verinfo.verdef->vd_flags;
3599 a->vna_nextptr = t->vn_auxptr;
3601 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3602 ++rinfo->vers;
3604 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3606 t->vn_auxptr = a;
3608 return true;
3611 /* Figure out appropriate versions for all the symbols. We may not
3612 have the version number script until we have read all of the input
3613 files, so until that point we don't know which symbols should be
3614 local. This function is called via elf_link_hash_traverse. */
3616 static boolean
3617 elf_link_assign_sym_version (h, data)
3618 struct elf_link_hash_entry *h;
3619 PTR data;
3621 struct elf_assign_sym_version_info *sinfo =
3622 (struct elf_assign_sym_version_info *) data;
3623 struct bfd_link_info *info = sinfo->info;
3624 struct elf_backend_data *bed;
3625 struct elf_info_failed eif;
3626 char *p;
3628 /* Fix the symbol flags. */
3629 eif.failed = false;
3630 eif.info = info;
3631 if (! elf_fix_symbol_flags (h, &eif))
3633 if (eif.failed)
3634 sinfo->failed = true;
3635 return false;
3638 /* We only need version numbers for symbols defined in regular
3639 objects. */
3640 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3641 return true;
3643 bed = get_elf_backend_data (sinfo->output_bfd);
3644 p = strchr (h->root.root.string, ELF_VER_CHR);
3645 if (p != NULL && h->verinfo.vertree == NULL)
3647 struct bfd_elf_version_tree *t;
3648 boolean hidden;
3650 hidden = true;
3652 /* There are two consecutive ELF_VER_CHR characters if this is
3653 not a hidden symbol. */
3654 ++p;
3655 if (*p == ELF_VER_CHR)
3657 hidden = false;
3658 ++p;
3661 /* If there is no version string, we can just return out. */
3662 if (*p == '\0')
3664 if (hidden)
3665 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3666 return true;
3669 /* Look for the version. If we find it, it is no longer weak. */
3670 for (t = sinfo->verdefs; t != NULL; t = t->next)
3672 if (strcmp (t->name, p) == 0)
3674 int len;
3675 char *alc;
3676 struct bfd_elf_version_expr *d;
3678 len = p - h->root.root.string;
3679 alc = bfd_alloc (sinfo->output_bfd, len);
3680 if (alc == NULL)
3681 return false;
3682 strncpy (alc, h->root.root.string, len - 1);
3683 alc[len - 1] = '\0';
3684 if (alc[len - 2] == ELF_VER_CHR)
3685 alc[len - 2] = '\0';
3687 h->verinfo.vertree = t;
3688 t->used = true;
3689 d = NULL;
3691 if (t->globals != NULL)
3693 for (d = t->globals; d != NULL; d = d->next)
3694 if ((*d->match) (d, alc))
3695 break;
3698 /* See if there is anything to force this symbol to
3699 local scope. */
3700 if (d == NULL && t->locals != NULL)
3702 for (d = t->locals; d != NULL; d = d->next)
3704 if ((*d->match) (d, alc))
3706 if (h->dynindx != -1
3707 && info->shared
3708 && ! sinfo->export_dynamic)
3710 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3711 (*bed->elf_backend_hide_symbol) (h);
3712 /* FIXME: The name of the symbol has
3713 already been recorded in the dynamic
3714 string table section. */
3717 break;
3722 bfd_release (sinfo->output_bfd, alc);
3723 break;
3727 /* If we are building an application, we need to create a
3728 version node for this version. */
3729 if (t == NULL && ! info->shared)
3731 struct bfd_elf_version_tree **pp;
3732 int version_index;
3734 /* If we aren't going to export this symbol, we don't need
3735 to worry about it. */
3736 if (h->dynindx == -1)
3737 return true;
3739 t = ((struct bfd_elf_version_tree *)
3740 bfd_alloc (sinfo->output_bfd, sizeof *t));
3741 if (t == NULL)
3743 sinfo->failed = true;
3744 return false;
3747 t->next = NULL;
3748 t->name = p;
3749 t->globals = NULL;
3750 t->locals = NULL;
3751 t->deps = NULL;
3752 t->name_indx = (unsigned int) -1;
3753 t->used = true;
3755 version_index = 1;
3756 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3757 ++version_index;
3758 t->vernum = version_index;
3760 *pp = t;
3762 h->verinfo.vertree = t;
3764 else if (t == NULL)
3766 /* We could not find the version for a symbol when
3767 generating a shared archive. Return an error. */
3768 (*_bfd_error_handler)
3769 (_("%s: undefined versioned symbol name %s"),
3770 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3771 bfd_set_error (bfd_error_bad_value);
3772 sinfo->failed = true;
3773 return false;
3776 if (hidden)
3777 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3780 /* If we don't have a version for this symbol, see if we can find
3781 something. */
3782 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3784 struct bfd_elf_version_tree *t;
3785 struct bfd_elf_version_tree *deflt;
3786 struct bfd_elf_version_expr *d;
3788 /* See if can find what version this symbol is in. If the
3789 symbol is supposed to be local, then don't actually register
3790 it. */
3791 deflt = NULL;
3792 for (t = sinfo->verdefs; t != NULL; t = t->next)
3794 if (t->globals != NULL)
3796 for (d = t->globals; d != NULL; d = d->next)
3798 if ((*d->match) (d, h->root.root.string))
3800 h->verinfo.vertree = t;
3801 break;
3805 if (d != NULL)
3806 break;
3809 if (t->locals != NULL)
3811 for (d = t->locals; d != NULL; d = d->next)
3813 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3814 deflt = t;
3815 else if ((*d->match) (d, h->root.root.string))
3817 h->verinfo.vertree = t;
3818 if (h->dynindx != -1
3819 && info->shared
3820 && ! sinfo->export_dynamic)
3822 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3823 (*bed->elf_backend_hide_symbol) (h);
3824 /* FIXME: The name of the symbol has already
3825 been recorded in the dynamic string table
3826 section. */
3828 break;
3832 if (d != NULL)
3833 break;
3837 if (deflt != NULL && h->verinfo.vertree == NULL)
3839 h->verinfo.vertree = deflt;
3840 if (h->dynindx != -1
3841 && info->shared
3842 && ! sinfo->export_dynamic)
3844 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3845 (*bed->elf_backend_hide_symbol) (h);
3846 /* FIXME: The name of the symbol has already been
3847 recorded in the dynamic string table section. */
3852 return true;
3855 /* Final phase of ELF linker. */
3857 /* A structure we use to avoid passing large numbers of arguments. */
3859 struct elf_final_link_info
3861 /* General link information. */
3862 struct bfd_link_info *info;
3863 /* Output BFD. */
3864 bfd *output_bfd;
3865 /* Symbol string table. */
3866 struct bfd_strtab_hash *symstrtab;
3867 /* .dynsym section. */
3868 asection *dynsym_sec;
3869 /* .hash section. */
3870 asection *hash_sec;
3871 /* symbol version section (.gnu.version). */
3872 asection *symver_sec;
3873 /* Buffer large enough to hold contents of any section. */
3874 bfd_byte *contents;
3875 /* Buffer large enough to hold external relocs of any section. */
3876 PTR external_relocs;
3877 /* Buffer large enough to hold internal relocs of any section. */
3878 Elf_Internal_Rela *internal_relocs;
3879 /* Buffer large enough to hold external local symbols of any input
3880 BFD. */
3881 Elf_External_Sym *external_syms;
3882 /* Buffer large enough to hold internal local symbols of any input
3883 BFD. */
3884 Elf_Internal_Sym *internal_syms;
3885 /* Array large enough to hold a symbol index for each local symbol
3886 of any input BFD. */
3887 long *indices;
3888 /* Array large enough to hold a section pointer for each local
3889 symbol of any input BFD. */
3890 asection **sections;
3891 /* Buffer to hold swapped out symbols. */
3892 Elf_External_Sym *symbuf;
3893 /* Number of swapped out symbols in buffer. */
3894 size_t symbuf_count;
3895 /* Number of symbols which fit in symbuf. */
3896 size_t symbuf_size;
3899 static boolean elf_link_output_sym
3900 PARAMS ((struct elf_final_link_info *, const char *,
3901 Elf_Internal_Sym *, asection *));
3902 static boolean elf_link_flush_output_syms
3903 PARAMS ((struct elf_final_link_info *));
3904 static boolean elf_link_output_extsym
3905 PARAMS ((struct elf_link_hash_entry *, PTR));
3906 static boolean elf_link_input_bfd
3907 PARAMS ((struct elf_final_link_info *, bfd *));
3908 static boolean elf_reloc_link_order
3909 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3910 struct bfd_link_order *));
3912 /* This struct is used to pass information to elf_link_output_extsym. */
3914 struct elf_outext_info
3916 boolean failed;
3917 boolean localsyms;
3918 struct elf_final_link_info *finfo;
3921 /* Compute the size of, and allocate space for, REL_HDR which is the
3922 section header for a section containing relocations for O. */
3924 static boolean
3925 elf_link_size_reloc_section (abfd, rel_hdr, o)
3926 bfd *abfd;
3927 Elf_Internal_Shdr *rel_hdr;
3928 asection *o;
3930 register struct elf_link_hash_entry **p, **pend;
3931 unsigned reloc_count;
3933 /* Figure out how many relocations there will be. */
3934 if (rel_hdr == &elf_section_data (o)->rel_hdr)
3935 reloc_count = elf_section_data (o)->rel_count;
3936 else
3937 reloc_count = elf_section_data (o)->rel_count2;
3939 /* That allows us to calculate the size of the section. */
3940 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
3942 /* The contents field must last into write_object_contents, so we
3943 allocate it with bfd_alloc rather than malloc. */
3944 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
3945 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
3946 return false;
3948 /* We only allocate one set of hash entries, so we only do it the
3949 first time we are called. */
3950 if (elf_section_data (o)->rel_hashes == NULL)
3952 p = ((struct elf_link_hash_entry **)
3953 bfd_malloc (o->reloc_count
3954 * sizeof (struct elf_link_hash_entry *)));
3955 if (p == NULL && o->reloc_count != 0)
3956 return false;
3958 elf_section_data (o)->rel_hashes = p;
3959 pend = p + o->reloc_count;
3960 for (; p < pend; p++)
3961 *p = NULL;
3964 return true;
3967 /* When performing a relocateable link, the input relocations are
3968 preserved. But, if they reference global symbols, the indices
3969 referenced must be updated. Update all the relocations in
3970 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
3972 static void
3973 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
3974 bfd *abfd;
3975 Elf_Internal_Shdr *rel_hdr;
3976 unsigned int count;
3977 struct elf_link_hash_entry **rel_hash;
3979 unsigned int i;
3981 for (i = 0; i < count; i++, rel_hash++)
3983 if (*rel_hash == NULL)
3984 continue;
3986 BFD_ASSERT ((*rel_hash)->indx >= 0);
3988 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
3990 Elf_External_Rel *erel;
3991 Elf_Internal_Rel irel;
3993 erel = (Elf_External_Rel *) rel_hdr->contents + i;
3994 elf_swap_reloc_in (abfd, erel, &irel);
3995 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
3996 ELF_R_TYPE (irel.r_info));
3997 elf_swap_reloc_out (abfd, &irel, erel);
3999 else
4001 Elf_External_Rela *erela;
4002 Elf_Internal_Rela irela;
4004 BFD_ASSERT (rel_hdr->sh_entsize
4005 == sizeof (Elf_External_Rela));
4007 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4008 elf_swap_reloca_in (abfd, erela, &irela);
4009 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4010 ELF_R_TYPE (irela.r_info));
4011 elf_swap_reloca_out (abfd, &irela, erela);
4016 /* Do the final step of an ELF link. */
4018 boolean
4019 elf_bfd_final_link (abfd, info)
4020 bfd *abfd;
4021 struct bfd_link_info *info;
4023 boolean dynamic;
4024 bfd *dynobj;
4025 struct elf_final_link_info finfo;
4026 register asection *o;
4027 register struct bfd_link_order *p;
4028 register bfd *sub;
4029 size_t max_contents_size;
4030 size_t max_external_reloc_size;
4031 size_t max_internal_reloc_count;
4032 size_t max_sym_count;
4033 file_ptr off;
4034 Elf_Internal_Sym elfsym;
4035 unsigned int i;
4036 Elf_Internal_Shdr *symtab_hdr;
4037 Elf_Internal_Shdr *symstrtab_hdr;
4038 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4039 struct elf_outext_info eoinfo;
4041 if (info->shared)
4042 abfd->flags |= DYNAMIC;
4044 dynamic = elf_hash_table (info)->dynamic_sections_created;
4045 dynobj = elf_hash_table (info)->dynobj;
4047 finfo.info = info;
4048 finfo.output_bfd = abfd;
4049 finfo.symstrtab = elf_stringtab_init ();
4050 if (finfo.symstrtab == NULL)
4051 return false;
4053 if (! dynamic)
4055 finfo.dynsym_sec = NULL;
4056 finfo.hash_sec = NULL;
4057 finfo.symver_sec = NULL;
4059 else
4061 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4062 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4063 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4064 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4065 /* Note that it is OK if symver_sec is NULL. */
4068 finfo.contents = NULL;
4069 finfo.external_relocs = NULL;
4070 finfo.internal_relocs = NULL;
4071 finfo.external_syms = NULL;
4072 finfo.internal_syms = NULL;
4073 finfo.indices = NULL;
4074 finfo.sections = NULL;
4075 finfo.symbuf = NULL;
4076 finfo.symbuf_count = 0;
4078 /* Count up the number of relocations we will output for each output
4079 section, so that we know the sizes of the reloc sections. We
4080 also figure out some maximum sizes. */
4081 max_contents_size = 0;
4082 max_external_reloc_size = 0;
4083 max_internal_reloc_count = 0;
4084 max_sym_count = 0;
4085 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4087 o->reloc_count = 0;
4089 for (p = o->link_order_head; p != NULL; p = p->next)
4091 if (p->type == bfd_section_reloc_link_order
4092 || p->type == bfd_symbol_reloc_link_order)
4093 ++o->reloc_count;
4094 else if (p->type == bfd_indirect_link_order)
4096 asection *sec;
4098 sec = p->u.indirect.section;
4100 /* Mark all sections which are to be included in the
4101 link. This will normally be every section. We need
4102 to do this so that we can identify any sections which
4103 the linker has decided to not include. */
4104 sec->linker_mark = true;
4106 if (info->relocateable || info->emitrelocations)
4107 o->reloc_count += sec->reloc_count;
4109 if (sec->_raw_size > max_contents_size)
4110 max_contents_size = sec->_raw_size;
4111 if (sec->_cooked_size > max_contents_size)
4112 max_contents_size = sec->_cooked_size;
4114 /* We are interested in just local symbols, not all
4115 symbols. */
4116 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4117 && (sec->owner->flags & DYNAMIC) == 0)
4119 size_t sym_count;
4121 if (elf_bad_symtab (sec->owner))
4122 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4123 / sizeof (Elf_External_Sym));
4124 else
4125 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4127 if (sym_count > max_sym_count)
4128 max_sym_count = sym_count;
4130 if ((sec->flags & SEC_RELOC) != 0)
4132 size_t ext_size;
4134 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4135 if (ext_size > max_external_reloc_size)
4136 max_external_reloc_size = ext_size;
4137 if (sec->reloc_count > max_internal_reloc_count)
4138 max_internal_reloc_count = sec->reloc_count;
4144 if (o->reloc_count > 0)
4145 o->flags |= SEC_RELOC;
4146 else
4148 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4149 set it (this is probably a bug) and if it is set
4150 assign_section_numbers will create a reloc section. */
4151 o->flags &=~ SEC_RELOC;
4154 /* If the SEC_ALLOC flag is not set, force the section VMA to
4155 zero. This is done in elf_fake_sections as well, but forcing
4156 the VMA to 0 here will ensure that relocs against these
4157 sections are handled correctly. */
4158 if ((o->flags & SEC_ALLOC) == 0
4159 && ! o->user_set_vma)
4160 o->vma = 0;
4163 /* Figure out the file positions for everything but the symbol table
4164 and the relocs. We set symcount to force assign_section_numbers
4165 to create a symbol table. */
4166 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4167 BFD_ASSERT (! abfd->output_has_begun);
4168 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4169 goto error_return;
4171 /* Figure out how many relocations we will have in each section.
4172 Just using RELOC_COUNT isn't good enough since that doesn't
4173 maintain a separate value for REL vs. RELA relocations. */
4174 if (info->relocateable || info->emitrelocations)
4175 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4176 for (o = sub->sections; o != NULL; o = o->next)
4178 asection *output_section;
4180 if (! o->linker_mark)
4182 /* This section was omitted from the link. */
4183 continue;
4186 output_section = o->output_section;
4188 if (output_section != NULL
4189 && (o->flags & SEC_RELOC) != 0)
4191 struct bfd_elf_section_data *esdi
4192 = elf_section_data (o);
4193 struct bfd_elf_section_data *esdo
4194 = elf_section_data (output_section);
4195 unsigned int *rel_count;
4196 unsigned int *rel_count2;
4198 /* We must be careful to add the relocation froms the
4199 input section to the right output count. */
4200 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4202 rel_count = &esdo->rel_count;
4203 rel_count2 = &esdo->rel_count2;
4205 else
4207 rel_count = &esdo->rel_count2;
4208 rel_count2 = &esdo->rel_count;
4211 *rel_count += (esdi->rel_hdr.sh_size
4212 / esdi->rel_hdr.sh_entsize);
4213 if (esdi->rel_hdr2)
4214 *rel_count2 += (esdi->rel_hdr2->sh_size
4215 / esdi->rel_hdr2->sh_entsize);
4219 /* That created the reloc sections. Set their sizes, and assign
4220 them file positions, and allocate some buffers. */
4221 for (o = abfd->sections; o != NULL; o = o->next)
4223 if ((o->flags & SEC_RELOC) != 0)
4225 if (!elf_link_size_reloc_section (abfd,
4226 &elf_section_data (o)->rel_hdr,
4228 goto error_return;
4230 if (elf_section_data (o)->rel_hdr2
4231 && !elf_link_size_reloc_section (abfd,
4232 elf_section_data (o)->rel_hdr2,
4234 goto error_return;
4237 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4238 to count upwards while actually outputting the relocations. */
4239 elf_section_data (o)->rel_count = 0;
4240 elf_section_data (o)->rel_count2 = 0;
4243 _bfd_elf_assign_file_positions_for_relocs (abfd);
4245 /* We have now assigned file positions for all the sections except
4246 .symtab and .strtab. We start the .symtab section at the current
4247 file position, and write directly to it. We build the .strtab
4248 section in memory. */
4249 bfd_get_symcount (abfd) = 0;
4250 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4251 /* sh_name is set in prep_headers. */
4252 symtab_hdr->sh_type = SHT_SYMTAB;
4253 symtab_hdr->sh_flags = 0;
4254 symtab_hdr->sh_addr = 0;
4255 symtab_hdr->sh_size = 0;
4256 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4257 /* sh_link is set in assign_section_numbers. */
4258 /* sh_info is set below. */
4259 /* sh_offset is set just below. */
4260 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4262 off = elf_tdata (abfd)->next_file_pos;
4263 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4265 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4266 incorrect. We do not yet know the size of the .symtab section.
4267 We correct next_file_pos below, after we do know the size. */
4269 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4270 continuously seeking to the right position in the file. */
4271 if (! info->keep_memory || max_sym_count < 20)
4272 finfo.symbuf_size = 20;
4273 else
4274 finfo.symbuf_size = max_sym_count;
4275 finfo.symbuf = ((Elf_External_Sym *)
4276 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4277 if (finfo.symbuf == NULL)
4278 goto error_return;
4280 /* Start writing out the symbol table. The first symbol is always a
4281 dummy symbol. */
4282 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4284 elfsym.st_value = 0;
4285 elfsym.st_size = 0;
4286 elfsym.st_info = 0;
4287 elfsym.st_other = 0;
4288 elfsym.st_shndx = SHN_UNDEF;
4289 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4290 &elfsym, bfd_und_section_ptr))
4291 goto error_return;
4294 #if 0
4295 /* Some standard ELF linkers do this, but we don't because it causes
4296 bootstrap comparison failures. */
4297 /* Output a file symbol for the output file as the second symbol.
4298 We output this even if we are discarding local symbols, although
4299 I'm not sure if this is correct. */
4300 elfsym.st_value = 0;
4301 elfsym.st_size = 0;
4302 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4303 elfsym.st_other = 0;
4304 elfsym.st_shndx = SHN_ABS;
4305 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4306 &elfsym, bfd_abs_section_ptr))
4307 goto error_return;
4308 #endif
4310 /* Output a symbol for each section. We output these even if we are
4311 discarding local symbols, since they are used for relocs. These
4312 symbols have no names. We store the index of each one in the
4313 index field of the section, so that we can find it again when
4314 outputting relocs. */
4315 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4317 elfsym.st_size = 0;
4318 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4319 elfsym.st_other = 0;
4320 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4322 o = section_from_elf_index (abfd, i);
4323 if (o != NULL)
4324 o->target_index = bfd_get_symcount (abfd);
4325 elfsym.st_shndx = i;
4326 if (info->relocateable || o == NULL)
4327 elfsym.st_value = 0;
4328 else
4329 elfsym.st_value = o->vma;
4330 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4331 &elfsym, o))
4332 goto error_return;
4336 /* Allocate some memory to hold information read in from the input
4337 files. */
4338 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4339 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4340 finfo.internal_relocs = ((Elf_Internal_Rela *)
4341 bfd_malloc (max_internal_reloc_count
4342 * sizeof (Elf_Internal_Rela)
4343 * bed->s->int_rels_per_ext_rel));
4344 finfo.external_syms = ((Elf_External_Sym *)
4345 bfd_malloc (max_sym_count
4346 * sizeof (Elf_External_Sym)));
4347 finfo.internal_syms = ((Elf_Internal_Sym *)
4348 bfd_malloc (max_sym_count
4349 * sizeof (Elf_Internal_Sym)));
4350 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4351 finfo.sections = ((asection **)
4352 bfd_malloc (max_sym_count * sizeof (asection *)));
4353 if ((finfo.contents == NULL && max_contents_size != 0)
4354 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4355 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4356 || (finfo.external_syms == NULL && max_sym_count != 0)
4357 || (finfo.internal_syms == NULL && max_sym_count != 0)
4358 || (finfo.indices == NULL && max_sym_count != 0)
4359 || (finfo.sections == NULL && max_sym_count != 0))
4360 goto error_return;
4362 /* Since ELF permits relocations to be against local symbols, we
4363 must have the local symbols available when we do the relocations.
4364 Since we would rather only read the local symbols once, and we
4365 would rather not keep them in memory, we handle all the
4366 relocations for a single input file at the same time.
4368 Unfortunately, there is no way to know the total number of local
4369 symbols until we have seen all of them, and the local symbol
4370 indices precede the global symbol indices. This means that when
4371 we are generating relocateable output, and we see a reloc against
4372 a global symbol, we can not know the symbol index until we have
4373 finished examining all the local symbols to see which ones we are
4374 going to output. To deal with this, we keep the relocations in
4375 memory, and don't output them until the end of the link. This is
4376 an unfortunate waste of memory, but I don't see a good way around
4377 it. Fortunately, it only happens when performing a relocateable
4378 link, which is not the common case. FIXME: If keep_memory is set
4379 we could write the relocs out and then read them again; I don't
4380 know how bad the memory loss will be. */
4382 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4383 sub->output_has_begun = false;
4384 for (o = abfd->sections; o != NULL; o = o->next)
4386 for (p = o->link_order_head; p != NULL; p = p->next)
4388 if (p->type == bfd_indirect_link_order
4389 && (bfd_get_flavour (p->u.indirect.section->owner)
4390 == bfd_target_elf_flavour))
4392 sub = p->u.indirect.section->owner;
4393 if (! sub->output_has_begun)
4395 if (! elf_link_input_bfd (&finfo, sub))
4396 goto error_return;
4397 sub->output_has_begun = true;
4400 else if (p->type == bfd_section_reloc_link_order
4401 || p->type == bfd_symbol_reloc_link_order)
4403 if (! elf_reloc_link_order (abfd, info, o, p))
4404 goto error_return;
4406 else
4408 if (! _bfd_default_link_order (abfd, info, o, p))
4409 goto error_return;
4414 /* That wrote out all the local symbols. Finish up the symbol table
4415 with the global symbols. Even if we want to strip everything we
4416 can, we still need to deal with those global symbols that got
4417 converted to local in a version script. */
4419 if (info->shared)
4421 /* Output any global symbols that got converted to local in a
4422 version script. We do this in a separate step since ELF
4423 requires all local symbols to appear prior to any global
4424 symbols. FIXME: We should only do this if some global
4425 symbols were, in fact, converted to become local. FIXME:
4426 Will this work correctly with the Irix 5 linker? */
4427 eoinfo.failed = false;
4428 eoinfo.finfo = &finfo;
4429 eoinfo.localsyms = true;
4430 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4431 (PTR) &eoinfo);
4432 if (eoinfo.failed)
4433 return false;
4436 /* The sh_info field records the index of the first non local symbol. */
4437 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4439 if (dynamic)
4441 Elf_Internal_Sym sym;
4442 Elf_External_Sym *dynsym =
4443 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4444 long last_local = 0;
4446 /* Write out the section symbols for the output sections. */
4447 if (info->shared)
4449 asection *s;
4451 sym.st_size = 0;
4452 sym.st_name = 0;
4453 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4454 sym.st_other = 0;
4456 for (s = abfd->sections; s != NULL; s = s->next)
4458 int indx;
4459 indx = elf_section_data (s)->this_idx;
4460 BFD_ASSERT (indx > 0);
4461 sym.st_shndx = indx;
4462 sym.st_value = s->vma;
4464 elf_swap_symbol_out (abfd, &sym,
4465 dynsym + elf_section_data (s)->dynindx);
4468 last_local = bfd_count_sections (abfd);
4471 /* Write out the local dynsyms. */
4472 if (elf_hash_table (info)->dynlocal)
4474 struct elf_link_local_dynamic_entry *e;
4475 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4477 asection *s;
4479 sym.st_size = e->isym.st_size;
4480 sym.st_other = e->isym.st_other;
4482 /* Copy the internal symbol as is.
4483 Note that we saved a word of storage and overwrote
4484 the original st_name with the dynstr_index. */
4485 sym = e->isym;
4487 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4489 s = bfd_section_from_elf_index (e->input_bfd,
4490 e->isym.st_shndx);
4492 sym.st_shndx =
4493 elf_section_data (s->output_section)->this_idx;
4494 sym.st_value = (s->output_section->vma
4495 + s->output_offset
4496 + e->isym.st_value);
4499 if (last_local < e->dynindx)
4500 last_local = e->dynindx;
4502 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4506 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4507 last_local + 1;
4510 /* We get the global symbols from the hash table. */
4511 eoinfo.failed = false;
4512 eoinfo.localsyms = false;
4513 eoinfo.finfo = &finfo;
4514 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4515 (PTR) &eoinfo);
4516 if (eoinfo.failed)
4517 return false;
4519 /* If backend needs to output some symbols not present in the hash
4520 table, do it now. */
4521 if (bed->elf_backend_output_arch_syms)
4523 if (! (*bed->elf_backend_output_arch_syms)
4524 (abfd, info, (PTR) &finfo,
4525 (boolean (*) PARAMS ((PTR, const char *,
4526 Elf_Internal_Sym *, asection *)))
4527 elf_link_output_sym))
4528 return false;
4531 /* Flush all symbols to the file. */
4532 if (! elf_link_flush_output_syms (&finfo))
4533 return false;
4535 /* Now we know the size of the symtab section. */
4536 off += symtab_hdr->sh_size;
4538 /* Finish up and write out the symbol string table (.strtab)
4539 section. */
4540 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4541 /* sh_name was set in prep_headers. */
4542 symstrtab_hdr->sh_type = SHT_STRTAB;
4543 symstrtab_hdr->sh_flags = 0;
4544 symstrtab_hdr->sh_addr = 0;
4545 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4546 symstrtab_hdr->sh_entsize = 0;
4547 symstrtab_hdr->sh_link = 0;
4548 symstrtab_hdr->sh_info = 0;
4549 /* sh_offset is set just below. */
4550 symstrtab_hdr->sh_addralign = 1;
4552 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4553 elf_tdata (abfd)->next_file_pos = off;
4555 if (bfd_get_symcount (abfd) > 0)
4557 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4558 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4559 return false;
4562 /* Adjust the relocs to have the correct symbol indices. */
4563 for (o = abfd->sections; o != NULL; o = o->next)
4565 if ((o->flags & SEC_RELOC) == 0)
4566 continue;
4568 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4569 elf_section_data (o)->rel_count,
4570 elf_section_data (o)->rel_hashes);
4571 if (elf_section_data (o)->rel_hdr2 != NULL)
4572 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4573 elf_section_data (o)->rel_count2,
4574 (elf_section_data (o)->rel_hashes
4575 + elf_section_data (o)->rel_count));
4577 /* Set the reloc_count field to 0 to prevent write_relocs from
4578 trying to swap the relocs out itself. */
4579 o->reloc_count = 0;
4582 /* If we are linking against a dynamic object, or generating a
4583 shared library, finish up the dynamic linking information. */
4584 if (dynamic)
4586 Elf_External_Dyn *dyncon, *dynconend;
4588 /* Fix up .dynamic entries. */
4589 o = bfd_get_section_by_name (dynobj, ".dynamic");
4590 BFD_ASSERT (o != NULL);
4592 dyncon = (Elf_External_Dyn *) o->contents;
4593 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4594 for (; dyncon < dynconend; dyncon++)
4596 Elf_Internal_Dyn dyn;
4597 const char *name;
4598 unsigned int type;
4600 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4602 switch (dyn.d_tag)
4604 default:
4605 break;
4606 case DT_INIT:
4607 name = info->init_function;
4608 goto get_sym;
4609 case DT_FINI:
4610 name = info->fini_function;
4611 get_sym:
4613 struct elf_link_hash_entry *h;
4615 h = elf_link_hash_lookup (elf_hash_table (info), name,
4616 false, false, true);
4617 if (h != NULL
4618 && (h->root.type == bfd_link_hash_defined
4619 || h->root.type == bfd_link_hash_defweak))
4621 dyn.d_un.d_val = h->root.u.def.value;
4622 o = h->root.u.def.section;
4623 if (o->output_section != NULL)
4624 dyn.d_un.d_val += (o->output_section->vma
4625 + o->output_offset);
4626 else
4628 /* The symbol is imported from another shared
4629 library and does not apply to this one. */
4630 dyn.d_un.d_val = 0;
4633 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4636 break;
4638 case DT_HASH:
4639 name = ".hash";
4640 goto get_vma;
4641 case DT_STRTAB:
4642 name = ".dynstr";
4643 goto get_vma;
4644 case DT_SYMTAB:
4645 name = ".dynsym";
4646 goto get_vma;
4647 case DT_VERDEF:
4648 name = ".gnu.version_d";
4649 goto get_vma;
4650 case DT_VERNEED:
4651 name = ".gnu.version_r";
4652 goto get_vma;
4653 case DT_VERSYM:
4654 name = ".gnu.version";
4655 get_vma:
4656 o = bfd_get_section_by_name (abfd, name);
4657 BFD_ASSERT (o != NULL);
4658 dyn.d_un.d_ptr = o->vma;
4659 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4660 break;
4662 case DT_REL:
4663 case DT_RELA:
4664 case DT_RELSZ:
4665 case DT_RELASZ:
4666 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4667 type = SHT_REL;
4668 else
4669 type = SHT_RELA;
4670 dyn.d_un.d_val = 0;
4671 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4673 Elf_Internal_Shdr *hdr;
4675 hdr = elf_elfsections (abfd)[i];
4676 if (hdr->sh_type == type
4677 && (hdr->sh_flags & SHF_ALLOC) != 0)
4679 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4680 dyn.d_un.d_val += hdr->sh_size;
4681 else
4683 if (dyn.d_un.d_val == 0
4684 || hdr->sh_addr < dyn.d_un.d_val)
4685 dyn.d_un.d_val = hdr->sh_addr;
4689 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4690 break;
4695 /* If we have created any dynamic sections, then output them. */
4696 if (dynobj != NULL)
4698 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4699 goto error_return;
4701 for (o = dynobj->sections; o != NULL; o = o->next)
4703 if ((o->flags & SEC_HAS_CONTENTS) == 0
4704 || o->_raw_size == 0)
4705 continue;
4706 if ((o->flags & SEC_LINKER_CREATED) == 0)
4708 /* At this point, we are only interested in sections
4709 created by elf_link_create_dynamic_sections. */
4710 continue;
4712 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4713 != SHT_STRTAB)
4714 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4716 if (! bfd_set_section_contents (abfd, o->output_section,
4717 o->contents, o->output_offset,
4718 o->_raw_size))
4719 goto error_return;
4721 else
4723 file_ptr off;
4725 /* The contents of the .dynstr section are actually in a
4726 stringtab. */
4727 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4728 if (bfd_seek (abfd, off, SEEK_SET) != 0
4729 || ! _bfd_stringtab_emit (abfd,
4730 elf_hash_table (info)->dynstr))
4731 goto error_return;
4736 /* If we have optimized stabs strings, output them. */
4737 if (elf_hash_table (info)->stab_info != NULL)
4739 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4740 goto error_return;
4743 if (finfo.symstrtab != NULL)
4744 _bfd_stringtab_free (finfo.symstrtab);
4745 if (finfo.contents != NULL)
4746 free (finfo.contents);
4747 if (finfo.external_relocs != NULL)
4748 free (finfo.external_relocs);
4749 if (finfo.internal_relocs != NULL)
4750 free (finfo.internal_relocs);
4751 if (finfo.external_syms != NULL)
4752 free (finfo.external_syms);
4753 if (finfo.internal_syms != NULL)
4754 free (finfo.internal_syms);
4755 if (finfo.indices != NULL)
4756 free (finfo.indices);
4757 if (finfo.sections != NULL)
4758 free (finfo.sections);
4759 if (finfo.symbuf != NULL)
4760 free (finfo.symbuf);
4761 for (o = abfd->sections; o != NULL; o = o->next)
4763 if ((o->flags & SEC_RELOC) != 0
4764 && elf_section_data (o)->rel_hashes != NULL)
4765 free (elf_section_data (o)->rel_hashes);
4768 elf_tdata (abfd)->linker = true;
4770 return true;
4772 error_return:
4773 if (finfo.symstrtab != NULL)
4774 _bfd_stringtab_free (finfo.symstrtab);
4775 if (finfo.contents != NULL)
4776 free (finfo.contents);
4777 if (finfo.external_relocs != NULL)
4778 free (finfo.external_relocs);
4779 if (finfo.internal_relocs != NULL)
4780 free (finfo.internal_relocs);
4781 if (finfo.external_syms != NULL)
4782 free (finfo.external_syms);
4783 if (finfo.internal_syms != NULL)
4784 free (finfo.internal_syms);
4785 if (finfo.indices != NULL)
4786 free (finfo.indices);
4787 if (finfo.sections != NULL)
4788 free (finfo.sections);
4789 if (finfo.symbuf != NULL)
4790 free (finfo.symbuf);
4791 for (o = abfd->sections; o != NULL; o = o->next)
4793 if ((o->flags & SEC_RELOC) != 0
4794 && elf_section_data (o)->rel_hashes != NULL)
4795 free (elf_section_data (o)->rel_hashes);
4798 return false;
4801 /* Add a symbol to the output symbol table. */
4803 static boolean
4804 elf_link_output_sym (finfo, name, elfsym, input_sec)
4805 struct elf_final_link_info *finfo;
4806 const char *name;
4807 Elf_Internal_Sym *elfsym;
4808 asection *input_sec;
4810 boolean (*output_symbol_hook) PARAMS ((bfd *,
4811 struct bfd_link_info *info,
4812 const char *,
4813 Elf_Internal_Sym *,
4814 asection *));
4816 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4817 elf_backend_link_output_symbol_hook;
4818 if (output_symbol_hook != NULL)
4820 if (! ((*output_symbol_hook)
4821 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4822 return false;
4825 if (name == (const char *) NULL || *name == '\0')
4826 elfsym->st_name = 0;
4827 else if (input_sec->flags & SEC_EXCLUDE)
4828 elfsym->st_name = 0;
4829 else
4831 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4832 name, true,
4833 false);
4834 if (elfsym->st_name == (unsigned long) -1)
4835 return false;
4838 if (finfo->symbuf_count >= finfo->symbuf_size)
4840 if (! elf_link_flush_output_syms (finfo))
4841 return false;
4844 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4845 (PTR) (finfo->symbuf + finfo->symbuf_count));
4846 ++finfo->symbuf_count;
4848 ++ bfd_get_symcount (finfo->output_bfd);
4850 return true;
4853 /* Flush the output symbols to the file. */
4855 static boolean
4856 elf_link_flush_output_syms (finfo)
4857 struct elf_final_link_info *finfo;
4859 if (finfo->symbuf_count > 0)
4861 Elf_Internal_Shdr *symtab;
4863 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4865 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4866 SEEK_SET) != 0
4867 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4868 sizeof (Elf_External_Sym), finfo->output_bfd)
4869 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4870 return false;
4872 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4874 finfo->symbuf_count = 0;
4877 return true;
4880 /* Add an external symbol to the symbol table. This is called from
4881 the hash table traversal routine. When generating a shared object,
4882 we go through the symbol table twice. The first time we output
4883 anything that might have been forced to local scope in a version
4884 script. The second time we output the symbols that are still
4885 global symbols. */
4887 static boolean
4888 elf_link_output_extsym (h, data)
4889 struct elf_link_hash_entry *h;
4890 PTR data;
4892 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4893 struct elf_final_link_info *finfo = eoinfo->finfo;
4894 boolean strip;
4895 Elf_Internal_Sym sym;
4896 asection *input_sec;
4898 /* Decide whether to output this symbol in this pass. */
4899 if (eoinfo->localsyms)
4901 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4902 return true;
4904 else
4906 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4907 return true;
4910 /* If we are not creating a shared library, and this symbol is
4911 referenced by a shared library but is not defined anywhere, then
4912 warn that it is undefined. If we do not do this, the runtime
4913 linker will complain that the symbol is undefined when the
4914 program is run. We don't have to worry about symbols that are
4915 referenced by regular files, because we will already have issued
4916 warnings for them. */
4917 if (! finfo->info->relocateable
4918 && ! (finfo->info->shared
4919 && !finfo->info->no_undefined)
4920 && h->root.type == bfd_link_hash_undefined
4921 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
4922 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4924 if (! ((*finfo->info->callbacks->undefined_symbol)
4925 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
4926 (asection *) NULL, 0, true)))
4928 eoinfo->failed = true;
4929 return false;
4933 /* We don't want to output symbols that have never been mentioned by
4934 a regular file, or that we have been told to strip. However, if
4935 h->indx is set to -2, the symbol is used by a reloc and we must
4936 output it. */
4937 if (h->indx == -2)
4938 strip = false;
4939 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
4940 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
4941 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
4942 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4943 strip = true;
4944 else if (finfo->info->strip == strip_all
4945 || (finfo->info->strip == strip_some
4946 && bfd_hash_lookup (finfo->info->keep_hash,
4947 h->root.root.string,
4948 false, false) == NULL))
4949 strip = true;
4950 else
4951 strip = false;
4953 /* If we're stripping it, and it's not a dynamic symbol, there's
4954 nothing else to do unless it is a forced local symbol. */
4955 if (strip
4956 && h->dynindx == -1
4957 && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4958 return true;
4960 sym.st_value = 0;
4961 sym.st_size = h->size;
4962 sym.st_other = h->other;
4963 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4964 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
4965 else if (h->root.type == bfd_link_hash_undefweak
4966 || h->root.type == bfd_link_hash_defweak)
4967 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
4968 else
4969 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
4971 switch (h->root.type)
4973 default:
4974 case bfd_link_hash_new:
4975 abort ();
4976 return false;
4978 case bfd_link_hash_undefined:
4979 input_sec = bfd_und_section_ptr;
4980 sym.st_shndx = SHN_UNDEF;
4981 break;
4983 case bfd_link_hash_undefweak:
4984 input_sec = bfd_und_section_ptr;
4985 sym.st_shndx = SHN_UNDEF;
4986 break;
4988 case bfd_link_hash_defined:
4989 case bfd_link_hash_defweak:
4991 input_sec = h->root.u.def.section;
4992 if (input_sec->output_section != NULL)
4994 sym.st_shndx =
4995 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
4996 input_sec->output_section);
4997 if (sym.st_shndx == (unsigned short) -1)
4999 (*_bfd_error_handler)
5000 (_("%s: could not find output section %s for input section %s"),
5001 bfd_get_filename (finfo->output_bfd),
5002 input_sec->output_section->name,
5003 input_sec->name);
5004 eoinfo->failed = true;
5005 return false;
5008 /* ELF symbols in relocateable files are section relative,
5009 but in nonrelocateable files they are virtual
5010 addresses. */
5011 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5012 if (! finfo->info->relocateable)
5013 sym.st_value += input_sec->output_section->vma;
5015 else
5017 BFD_ASSERT (input_sec->owner == NULL
5018 || (input_sec->owner->flags & DYNAMIC) != 0);
5019 sym.st_shndx = SHN_UNDEF;
5020 input_sec = bfd_und_section_ptr;
5023 break;
5025 case bfd_link_hash_common:
5026 input_sec = h->root.u.c.p->section;
5027 sym.st_shndx = SHN_COMMON;
5028 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5029 break;
5031 case bfd_link_hash_indirect:
5032 /* These symbols are created by symbol versioning. They point
5033 to the decorated version of the name. For example, if the
5034 symbol foo@@GNU_1.2 is the default, which should be used when
5035 foo is used with no version, then we add an indirect symbol
5036 foo which points to foo@@GNU_1.2. We ignore these symbols,
5037 since the indirected symbol is already in the hash table. If
5038 the indirect symbol is non-ELF, fall through and output it. */
5039 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) == 0)
5040 return true;
5042 /* Fall through. */
5043 case bfd_link_hash_warning:
5044 /* We can't represent these symbols in ELF, although a warning
5045 symbol may have come from a .gnu.warning.SYMBOL section. We
5046 just put the target symbol in the hash table. If the target
5047 symbol does not really exist, don't do anything. */
5048 if (h->root.u.i.link->type == bfd_link_hash_new)
5049 return true;
5050 return (elf_link_output_extsym
5051 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5054 /* Give the processor backend a chance to tweak the symbol value,
5055 and also to finish up anything that needs to be done for this
5056 symbol. */
5057 if ((h->dynindx != -1
5058 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5059 && elf_hash_table (finfo->info)->dynamic_sections_created)
5061 struct elf_backend_data *bed;
5063 bed = get_elf_backend_data (finfo->output_bfd);
5064 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5065 (finfo->output_bfd, finfo->info, h, &sym)))
5067 eoinfo->failed = true;
5068 return false;
5072 /* If we are marking the symbol as undefined, and there are no
5073 non-weak references to this symbol from a regular object, then
5074 mark the symbol as weak undefined; if there are non-weak
5075 references, mark the symbol as strong. We can't do this earlier,
5076 because it might not be marked as undefined until the
5077 finish_dynamic_symbol routine gets through with it. */
5078 if (sym.st_shndx == SHN_UNDEF
5079 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5080 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5081 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5083 int bindtype;
5085 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5086 bindtype = STB_GLOBAL;
5087 else
5088 bindtype = STB_WEAK;
5089 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5092 /* If a symbol is not defined locally, we clear the visibility
5093 field. */
5094 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5095 sym.st_other ^= ELF_ST_VISIBILITY(sym.st_other);
5097 /* If this symbol should be put in the .dynsym section, then put it
5098 there now. We have already know the symbol index. We also fill
5099 in the entry in the .hash section. */
5100 if (h->dynindx != -1
5101 && elf_hash_table (finfo->info)->dynamic_sections_created)
5103 size_t bucketcount;
5104 size_t bucket;
5105 size_t hash_entry_size;
5106 bfd_byte *bucketpos;
5107 bfd_vma chain;
5109 sym.st_name = h->dynstr_index;
5111 elf_swap_symbol_out (finfo->output_bfd, &sym,
5112 (PTR) (((Elf_External_Sym *)
5113 finfo->dynsym_sec->contents)
5114 + h->dynindx));
5116 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5117 bucket = h->elf_hash_value % bucketcount;
5118 hash_entry_size
5119 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5120 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5121 + (bucket + 2) * hash_entry_size);
5122 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5123 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5124 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5125 ((bfd_byte *) finfo->hash_sec->contents
5126 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5128 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5130 Elf_Internal_Versym iversym;
5132 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5134 if (h->verinfo.verdef == NULL)
5135 iversym.vs_vers = 0;
5136 else
5137 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5139 else
5141 if (h->verinfo.vertree == NULL)
5142 iversym.vs_vers = 1;
5143 else
5144 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5147 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5148 iversym.vs_vers |= VERSYM_HIDDEN;
5150 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5151 (((Elf_External_Versym *)
5152 finfo->symver_sec->contents)
5153 + h->dynindx));
5157 /* If we're stripping it, then it was just a dynamic symbol, and
5158 there's nothing else to do. */
5159 if (strip)
5160 return true;
5162 h->indx = bfd_get_symcount (finfo->output_bfd);
5164 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5166 eoinfo->failed = true;
5167 return false;
5170 return true;
5173 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5174 originated from the section given by INPUT_REL_HDR) to the
5175 OUTPUT_BFD. */
5177 static void
5178 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5179 internal_relocs)
5180 bfd *output_bfd;
5181 asection *input_section;
5182 Elf_Internal_Shdr *input_rel_hdr;
5183 Elf_Internal_Rela *internal_relocs;
5185 Elf_Internal_Rela *irela;
5186 Elf_Internal_Rela *irelaend;
5187 Elf_Internal_Shdr *output_rel_hdr;
5188 asection *output_section;
5189 unsigned int *rel_countp = NULL;
5191 output_section = input_section->output_section;
5192 output_rel_hdr = NULL;
5194 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5195 == input_rel_hdr->sh_entsize)
5197 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5198 rel_countp = &elf_section_data (output_section)->rel_count;
5200 else if (elf_section_data (output_section)->rel_hdr2
5201 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5202 == input_rel_hdr->sh_entsize))
5204 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5205 rel_countp = &elf_section_data (output_section)->rel_count2;
5208 BFD_ASSERT (output_rel_hdr != NULL);
5210 irela = internal_relocs;
5211 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5212 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5214 Elf_External_Rel *erel;
5216 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5217 for (; irela < irelaend; irela++, erel++)
5219 Elf_Internal_Rel irel;
5221 irel.r_offset = irela->r_offset;
5222 irel.r_info = irela->r_info;
5223 BFD_ASSERT (irela->r_addend == 0);
5224 elf_swap_reloc_out (output_bfd, &irel, erel);
5227 else
5229 Elf_External_Rela *erela;
5231 BFD_ASSERT (input_rel_hdr->sh_entsize
5232 == sizeof (Elf_External_Rela));
5233 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5234 for (; irela < irelaend; irela++, erela++)
5235 elf_swap_reloca_out (output_bfd, irela, erela);
5238 /* Bump the counter, so that we know where to add the next set of
5239 relocations. */
5240 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5243 /* Link an input file into the linker output file. This function
5244 handles all the sections and relocations of the input file at once.
5245 This is so that we only have to read the local symbols once, and
5246 don't have to keep them in memory. */
5248 static boolean
5249 elf_link_input_bfd (finfo, input_bfd)
5250 struct elf_final_link_info *finfo;
5251 bfd *input_bfd;
5253 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5254 bfd *, asection *, bfd_byte *,
5255 Elf_Internal_Rela *,
5256 Elf_Internal_Sym *, asection **));
5257 bfd *output_bfd;
5258 Elf_Internal_Shdr *symtab_hdr;
5259 size_t locsymcount;
5260 size_t extsymoff;
5261 Elf_External_Sym *external_syms;
5262 Elf_External_Sym *esym;
5263 Elf_External_Sym *esymend;
5264 Elf_Internal_Sym *isym;
5265 long *pindex;
5266 asection **ppsection;
5267 asection *o;
5268 struct elf_backend_data *bed;
5270 output_bfd = finfo->output_bfd;
5271 bed = get_elf_backend_data (output_bfd);
5272 relocate_section = bed->elf_backend_relocate_section;
5274 /* If this is a dynamic object, we don't want to do anything here:
5275 we don't want the local symbols, and we don't want the section
5276 contents. */
5277 if ((input_bfd->flags & DYNAMIC) != 0)
5278 return true;
5280 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5281 if (elf_bad_symtab (input_bfd))
5283 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5284 extsymoff = 0;
5286 else
5288 locsymcount = symtab_hdr->sh_info;
5289 extsymoff = symtab_hdr->sh_info;
5292 /* Read the local symbols. */
5293 if (symtab_hdr->contents != NULL)
5294 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5295 else if (locsymcount == 0)
5296 external_syms = NULL;
5297 else
5299 external_syms = finfo->external_syms;
5300 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5301 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5302 locsymcount, input_bfd)
5303 != locsymcount * sizeof (Elf_External_Sym)))
5304 return false;
5307 /* Swap in the local symbols and write out the ones which we know
5308 are going into the output file. */
5309 esym = external_syms;
5310 esymend = esym + locsymcount;
5311 isym = finfo->internal_syms;
5312 pindex = finfo->indices;
5313 ppsection = finfo->sections;
5314 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5316 asection *isec;
5317 const char *name;
5318 Elf_Internal_Sym osym;
5320 elf_swap_symbol_in (input_bfd, esym, isym);
5321 *pindex = -1;
5323 if (elf_bad_symtab (input_bfd))
5325 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5327 *ppsection = NULL;
5328 continue;
5332 if (isym->st_shndx == SHN_UNDEF)
5333 isec = bfd_und_section_ptr;
5334 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5335 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5336 else if (isym->st_shndx == SHN_ABS)
5337 isec = bfd_abs_section_ptr;
5338 else if (isym->st_shndx == SHN_COMMON)
5339 isec = bfd_com_section_ptr;
5340 else
5342 /* Who knows? */
5343 isec = NULL;
5346 *ppsection = isec;
5348 /* Don't output the first, undefined, symbol. */
5349 if (esym == external_syms)
5350 continue;
5352 /* If we are stripping all symbols, we don't want to output this
5353 one. */
5354 if (finfo->info->strip == strip_all)
5355 continue;
5357 /* We never output section symbols. Instead, we use the section
5358 symbol of the corresponding section in the output file. */
5359 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5360 continue;
5362 /* If we are discarding all local symbols, we don't want to
5363 output this one. If we are generating a relocateable output
5364 file, then some of the local symbols may be required by
5365 relocs; we output them below as we discover that they are
5366 needed. */
5367 if (finfo->info->discard == discard_all)
5368 continue;
5370 /* If this symbol is defined in a section which we are
5371 discarding, we don't need to keep it, but note that
5372 linker_mark is only reliable for sections that have contents.
5373 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5374 as well as linker_mark. */
5375 if (isym->st_shndx > 0
5376 && isym->st_shndx < SHN_LORESERVE
5377 && isec != NULL
5378 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5379 || (! finfo->info->relocateable
5380 && (isec->flags & SEC_EXCLUDE) != 0)))
5381 continue;
5383 /* Get the name of the symbol. */
5384 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5385 isym->st_name);
5386 if (name == NULL)
5387 return false;
5389 /* See if we are discarding symbols with this name. */
5390 if ((finfo->info->strip == strip_some
5391 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5392 == NULL))
5393 || (finfo->info->discard == discard_l
5394 && bfd_is_local_label_name (input_bfd, name)))
5395 continue;
5397 /* If we get here, we are going to output this symbol. */
5399 osym = *isym;
5401 /* Adjust the section index for the output file. */
5402 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5403 isec->output_section);
5404 if (osym.st_shndx == (unsigned short) -1)
5405 return false;
5407 *pindex = bfd_get_symcount (output_bfd);
5409 /* ELF symbols in relocateable files are section relative, but
5410 in executable files they are virtual addresses. Note that
5411 this code assumes that all ELF sections have an associated
5412 BFD section with a reasonable value for output_offset; below
5413 we assume that they also have a reasonable value for
5414 output_section. Any special sections must be set up to meet
5415 these requirements. */
5416 osym.st_value += isec->output_offset;
5417 if (! finfo->info->relocateable)
5418 osym.st_value += isec->output_section->vma;
5420 if (! elf_link_output_sym (finfo, name, &osym, isec))
5421 return false;
5424 /* Relocate the contents of each section. */
5425 for (o = input_bfd->sections; o != NULL; o = o->next)
5427 bfd_byte *contents;
5429 if (! o->linker_mark)
5431 /* This section was omitted from the link. */
5432 continue;
5435 if ((o->flags & SEC_HAS_CONTENTS) == 0
5436 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5437 continue;
5439 if ((o->flags & SEC_LINKER_CREATED) != 0)
5441 /* Section was created by elf_link_create_dynamic_sections
5442 or somesuch. */
5443 continue;
5446 /* Get the contents of the section. They have been cached by a
5447 relaxation routine. Note that o is a section in an input
5448 file, so the contents field will not have been set by any of
5449 the routines which work on output files. */
5450 if (elf_section_data (o)->this_hdr.contents != NULL)
5451 contents = elf_section_data (o)->this_hdr.contents;
5452 else
5454 contents = finfo->contents;
5455 if (! bfd_get_section_contents (input_bfd, o, contents,
5456 (file_ptr) 0, o->_raw_size))
5457 return false;
5460 if ((o->flags & SEC_RELOC) != 0)
5462 Elf_Internal_Rela *internal_relocs;
5464 /* Get the swapped relocs. */
5465 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5466 (input_bfd, o, finfo->external_relocs,
5467 finfo->internal_relocs, false));
5468 if (internal_relocs == NULL
5469 && o->reloc_count > 0)
5470 return false;
5472 /* Relocate the section by invoking a back end routine.
5474 The back end routine is responsible for adjusting the
5475 section contents as necessary, and (if using Rela relocs
5476 and generating a relocateable output file) adjusting the
5477 reloc addend as necessary.
5479 The back end routine does not have to worry about setting
5480 the reloc address or the reloc symbol index.
5482 The back end routine is given a pointer to the swapped in
5483 internal symbols, and can access the hash table entries
5484 for the external symbols via elf_sym_hashes (input_bfd).
5486 When generating relocateable output, the back end routine
5487 must handle STB_LOCAL/STT_SECTION symbols specially. The
5488 output symbol is going to be a section symbol
5489 corresponding to the output section, which will require
5490 the addend to be adjusted. */
5492 if (! (*relocate_section) (output_bfd, finfo->info,
5493 input_bfd, o, contents,
5494 internal_relocs,
5495 finfo->internal_syms,
5496 finfo->sections))
5497 return false;
5499 if (finfo->info->relocateable || finfo->info->emitrelocations)
5501 Elf_Internal_Rela *irela;
5502 Elf_Internal_Rela *irelaend;
5503 struct elf_link_hash_entry **rel_hash;
5504 Elf_Internal_Shdr *input_rel_hdr;
5506 /* Adjust the reloc addresses and symbol indices. */
5508 irela = internal_relocs;
5509 irelaend =
5510 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5511 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5512 + elf_section_data (o->output_section)->rel_count
5513 + elf_section_data (o->output_section)->rel_count2);
5514 for (; irela < irelaend; irela++, rel_hash++)
5516 unsigned long r_symndx;
5517 Elf_Internal_Sym *isym;
5518 asection *sec;
5520 irela->r_offset += o->output_offset;
5522 /* Relocs in an executable have to be virtual addresses. */
5523 if (finfo->info->emitrelocations)
5524 irela->r_offset += o->output_section->vma;
5526 r_symndx = ELF_R_SYM (irela->r_info);
5528 if (r_symndx == 0)
5529 continue;
5531 if (r_symndx >= locsymcount
5532 || (elf_bad_symtab (input_bfd)
5533 && finfo->sections[r_symndx] == NULL))
5535 struct elf_link_hash_entry *rh;
5536 long indx;
5538 /* This is a reloc against a global symbol. We
5539 have not yet output all the local symbols, so
5540 we do not know the symbol index of any global
5541 symbol. We set the rel_hash entry for this
5542 reloc to point to the global hash table entry
5543 for this symbol. The symbol index is then
5544 set at the end of elf_bfd_final_link. */
5545 indx = r_symndx - extsymoff;
5546 rh = elf_sym_hashes (input_bfd)[indx];
5547 while (rh->root.type == bfd_link_hash_indirect
5548 || rh->root.type == bfd_link_hash_warning)
5549 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5551 /* Setting the index to -2 tells
5552 elf_link_output_extsym that this symbol is
5553 used by a reloc. */
5554 BFD_ASSERT (rh->indx < 0);
5555 rh->indx = -2;
5557 *rel_hash = rh;
5559 continue;
5562 /* This is a reloc against a local symbol. */
5564 *rel_hash = NULL;
5565 isym = finfo->internal_syms + r_symndx;
5566 sec = finfo->sections[r_symndx];
5567 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5569 /* I suppose the backend ought to fill in the
5570 section of any STT_SECTION symbol against a
5571 processor specific section. If we have
5572 discarded a section, the output_section will
5573 be the absolute section. */
5574 if (sec != NULL
5575 && (bfd_is_abs_section (sec)
5576 || (sec->output_section != NULL
5577 && bfd_is_abs_section (sec->output_section))))
5578 r_symndx = 0;
5579 else if (sec == NULL || sec->owner == NULL)
5581 bfd_set_error (bfd_error_bad_value);
5582 return false;
5584 else
5586 r_symndx = sec->output_section->target_index;
5587 BFD_ASSERT (r_symndx != 0);
5590 else
5592 if (finfo->indices[r_symndx] == -1)
5594 unsigned long link;
5595 const char *name;
5596 asection *osec;
5598 if (finfo->info->strip == strip_all)
5600 /* You can't do ld -r -s. */
5601 bfd_set_error (bfd_error_invalid_operation);
5602 return false;
5605 /* This symbol was skipped earlier, but
5606 since it is needed by a reloc, we
5607 must output it now. */
5608 link = symtab_hdr->sh_link;
5609 name = bfd_elf_string_from_elf_section (input_bfd,
5610 link,
5611 isym->st_name);
5612 if (name == NULL)
5613 return false;
5615 osec = sec->output_section;
5616 isym->st_shndx =
5617 _bfd_elf_section_from_bfd_section (output_bfd,
5618 osec);
5619 if (isym->st_shndx == (unsigned short) -1)
5620 return false;
5622 isym->st_value += sec->output_offset;
5623 if (! finfo->info->relocateable)
5624 isym->st_value += osec->vma;
5626 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5628 if (! elf_link_output_sym (finfo, name, isym, sec))
5629 return false;
5632 r_symndx = finfo->indices[r_symndx];
5635 irela->r_info = ELF_R_INFO (r_symndx,
5636 ELF_R_TYPE (irela->r_info));
5639 /* Swap out the relocs. */
5640 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5641 elf_link_output_relocs (output_bfd, o,
5642 input_rel_hdr,
5643 internal_relocs);
5644 internal_relocs
5645 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5646 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5647 if (input_rel_hdr)
5648 elf_link_output_relocs (output_bfd, o,
5649 input_rel_hdr,
5650 internal_relocs);
5654 /* Write out the modified section contents. */
5655 if (elf_section_data (o)->stab_info == NULL)
5657 if (! (o->flags & SEC_EXCLUDE) &&
5658 ! bfd_set_section_contents (output_bfd, o->output_section,
5659 contents, o->output_offset,
5660 (o->_cooked_size != 0
5661 ? o->_cooked_size
5662 : o->_raw_size)))
5663 return false;
5665 else
5667 if (! (_bfd_write_section_stabs
5668 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5669 o, &elf_section_data (o)->stab_info, contents)))
5670 return false;
5674 return true;
5677 /* Generate a reloc when linking an ELF file. This is a reloc
5678 requested by the linker, and does come from any input file. This
5679 is used to build constructor and destructor tables when linking
5680 with -Ur. */
5682 static boolean
5683 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5684 bfd *output_bfd;
5685 struct bfd_link_info *info;
5686 asection *output_section;
5687 struct bfd_link_order *link_order;
5689 reloc_howto_type *howto;
5690 long indx;
5691 bfd_vma offset;
5692 bfd_vma addend;
5693 struct elf_link_hash_entry **rel_hash_ptr;
5694 Elf_Internal_Shdr *rel_hdr;
5696 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5697 if (howto == NULL)
5699 bfd_set_error (bfd_error_bad_value);
5700 return false;
5703 addend = link_order->u.reloc.p->addend;
5705 /* Figure out the symbol index. */
5706 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5707 + elf_section_data (output_section)->rel_count
5708 + elf_section_data (output_section)->rel_count2);
5709 if (link_order->type == bfd_section_reloc_link_order)
5711 indx = link_order->u.reloc.p->u.section->target_index;
5712 BFD_ASSERT (indx != 0);
5713 *rel_hash_ptr = NULL;
5715 else
5717 struct elf_link_hash_entry *h;
5719 /* Treat a reloc against a defined symbol as though it were
5720 actually against the section. */
5721 h = ((struct elf_link_hash_entry *)
5722 bfd_wrapped_link_hash_lookup (output_bfd, info,
5723 link_order->u.reloc.p->u.name,
5724 false, false, true));
5725 if (h != NULL
5726 && (h->root.type == bfd_link_hash_defined
5727 || h->root.type == bfd_link_hash_defweak))
5729 asection *section;
5731 section = h->root.u.def.section;
5732 indx = section->output_section->target_index;
5733 *rel_hash_ptr = NULL;
5734 /* It seems that we ought to add the symbol value to the
5735 addend here, but in practice it has already been added
5736 because it was passed to constructor_callback. */
5737 addend += section->output_section->vma + section->output_offset;
5739 else if (h != NULL)
5741 /* Setting the index to -2 tells elf_link_output_extsym that
5742 this symbol is used by a reloc. */
5743 h->indx = -2;
5744 *rel_hash_ptr = h;
5745 indx = 0;
5747 else
5749 if (! ((*info->callbacks->unattached_reloc)
5750 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5751 (asection *) NULL, (bfd_vma) 0)))
5752 return false;
5753 indx = 0;
5757 /* If this is an inplace reloc, we must write the addend into the
5758 object file. */
5759 if (howto->partial_inplace && addend != 0)
5761 bfd_size_type size;
5762 bfd_reloc_status_type rstat;
5763 bfd_byte *buf;
5764 boolean ok;
5766 size = bfd_get_reloc_size (howto);
5767 buf = (bfd_byte *) bfd_zmalloc (size);
5768 if (buf == (bfd_byte *) NULL)
5769 return false;
5770 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5771 switch (rstat)
5773 case bfd_reloc_ok:
5774 break;
5775 default:
5776 case bfd_reloc_outofrange:
5777 abort ();
5778 case bfd_reloc_overflow:
5779 if (! ((*info->callbacks->reloc_overflow)
5780 (info,
5781 (link_order->type == bfd_section_reloc_link_order
5782 ? bfd_section_name (output_bfd,
5783 link_order->u.reloc.p->u.section)
5784 : link_order->u.reloc.p->u.name),
5785 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5786 (bfd_vma) 0)))
5788 free (buf);
5789 return false;
5791 break;
5793 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5794 (file_ptr) link_order->offset, size);
5795 free (buf);
5796 if (! ok)
5797 return false;
5800 /* The address of a reloc is relative to the section in a
5801 relocateable file, and is a virtual address in an executable
5802 file. */
5803 offset = link_order->offset;
5804 if (! info->relocateable)
5805 offset += output_section->vma;
5807 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5809 if (rel_hdr->sh_type == SHT_REL)
5811 Elf_Internal_Rel irel;
5812 Elf_External_Rel *erel;
5814 irel.r_offset = offset;
5815 irel.r_info = ELF_R_INFO (indx, howto->type);
5816 erel = ((Elf_External_Rel *) rel_hdr->contents
5817 + elf_section_data (output_section)->rel_count);
5818 elf_swap_reloc_out (output_bfd, &irel, erel);
5820 else
5822 Elf_Internal_Rela irela;
5823 Elf_External_Rela *erela;
5825 irela.r_offset = offset;
5826 irela.r_info = ELF_R_INFO (indx, howto->type);
5827 irela.r_addend = addend;
5828 erela = ((Elf_External_Rela *) rel_hdr->contents
5829 + elf_section_data (output_section)->rel_count);
5830 elf_swap_reloca_out (output_bfd, &irela, erela);
5833 ++elf_section_data (output_section)->rel_count;
5835 return true;
5839 /* Allocate a pointer to live in a linker created section. */
5841 boolean
5842 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5843 bfd *abfd;
5844 struct bfd_link_info *info;
5845 elf_linker_section_t *lsect;
5846 struct elf_link_hash_entry *h;
5847 const Elf_Internal_Rela *rel;
5849 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5850 elf_linker_section_pointers_t *linker_section_ptr;
5851 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5853 BFD_ASSERT (lsect != NULL);
5855 /* Is this a global symbol? */
5856 if (h != NULL)
5858 /* Has this symbol already been allocated, if so, our work is done */
5859 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5860 rel->r_addend,
5861 lsect->which))
5862 return true;
5864 ptr_linker_section_ptr = &h->linker_section_pointer;
5865 /* Make sure this symbol is output as a dynamic symbol. */
5866 if (h->dynindx == -1)
5868 if (! elf_link_record_dynamic_symbol (info, h))
5869 return false;
5872 if (lsect->rel_section)
5873 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5876 else /* Allocation of a pointer to a local symbol */
5878 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5880 /* Allocate a table to hold the local symbols if first time */
5881 if (!ptr)
5883 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5884 register unsigned int i;
5886 ptr = (elf_linker_section_pointers_t **)
5887 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5889 if (!ptr)
5890 return false;
5892 elf_local_ptr_offsets (abfd) = ptr;
5893 for (i = 0; i < num_symbols; i++)
5894 ptr[i] = (elf_linker_section_pointers_t *)0;
5897 /* Has this symbol already been allocated, if so, our work is done */
5898 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5899 rel->r_addend,
5900 lsect->which))
5901 return true;
5903 ptr_linker_section_ptr = &ptr[r_symndx];
5905 if (info->shared)
5907 /* If we are generating a shared object, we need to
5908 output a R_<xxx>_RELATIVE reloc so that the
5909 dynamic linker can adjust this GOT entry. */
5910 BFD_ASSERT (lsect->rel_section != NULL);
5911 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5915 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
5916 from internal memory. */
5917 BFD_ASSERT (ptr_linker_section_ptr != NULL);
5918 linker_section_ptr = (elf_linker_section_pointers_t *)
5919 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
5921 if (!linker_section_ptr)
5922 return false;
5924 linker_section_ptr->next = *ptr_linker_section_ptr;
5925 linker_section_ptr->addend = rel->r_addend;
5926 linker_section_ptr->which = lsect->which;
5927 linker_section_ptr->written_address_p = false;
5928 *ptr_linker_section_ptr = linker_section_ptr;
5930 #if 0
5931 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
5933 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
5934 lsect->hole_offset += ARCH_SIZE / 8;
5935 lsect->sym_offset += ARCH_SIZE / 8;
5936 if (lsect->sym_hash) /* Bump up symbol value if needed */
5938 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
5939 #ifdef DEBUG
5940 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
5941 lsect->sym_hash->root.root.string,
5942 (long)ARCH_SIZE / 8,
5943 (long)lsect->sym_hash->root.u.def.value);
5944 #endif
5947 else
5948 #endif
5949 linker_section_ptr->offset = lsect->section->_raw_size;
5951 lsect->section->_raw_size += ARCH_SIZE / 8;
5953 #ifdef DEBUG
5954 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
5955 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
5956 #endif
5958 return true;
5962 #if ARCH_SIZE==64
5963 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
5964 #endif
5965 #if ARCH_SIZE==32
5966 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
5967 #endif
5969 /* Fill in the address for a pointer generated in alinker section. */
5971 bfd_vma
5972 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
5973 bfd *output_bfd;
5974 bfd *input_bfd;
5975 struct bfd_link_info *info;
5976 elf_linker_section_t *lsect;
5977 struct elf_link_hash_entry *h;
5978 bfd_vma relocation;
5979 const Elf_Internal_Rela *rel;
5980 int relative_reloc;
5982 elf_linker_section_pointers_t *linker_section_ptr;
5984 BFD_ASSERT (lsect != NULL);
5986 if (h != NULL) /* global symbol */
5988 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5989 rel->r_addend,
5990 lsect->which);
5992 BFD_ASSERT (linker_section_ptr != NULL);
5994 if (! elf_hash_table (info)->dynamic_sections_created
5995 || (info->shared
5996 && info->symbolic
5997 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
5999 /* This is actually a static link, or it is a
6000 -Bsymbolic link and the symbol is defined
6001 locally. We must initialize this entry in the
6002 global section.
6004 When doing a dynamic link, we create a .rela.<xxx>
6005 relocation entry to initialize the value. This
6006 is done in the finish_dynamic_symbol routine. */
6007 if (!linker_section_ptr->written_address_p)
6009 linker_section_ptr->written_address_p = true;
6010 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6011 lsect->section->contents + linker_section_ptr->offset);
6015 else /* local symbol */
6017 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6018 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6019 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6020 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6021 rel->r_addend,
6022 lsect->which);
6024 BFD_ASSERT (linker_section_ptr != NULL);
6026 /* Write out pointer if it hasn't been rewritten out before */
6027 if (!linker_section_ptr->written_address_p)
6029 linker_section_ptr->written_address_p = true;
6030 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6031 lsect->section->contents + linker_section_ptr->offset);
6033 if (info->shared)
6035 asection *srel = lsect->rel_section;
6036 Elf_Internal_Rela outrel;
6038 /* We need to generate a relative reloc for the dynamic linker. */
6039 if (!srel)
6040 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6041 lsect->rel_name);
6043 BFD_ASSERT (srel != NULL);
6045 outrel.r_offset = (lsect->section->output_section->vma
6046 + lsect->section->output_offset
6047 + linker_section_ptr->offset);
6048 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6049 outrel.r_addend = 0;
6050 elf_swap_reloca_out (output_bfd, &outrel,
6051 (((Elf_External_Rela *)
6052 lsect->section->contents)
6053 + elf_section_data (lsect->section)->rel_count));
6054 ++elf_section_data (lsect->section)->rel_count;
6059 relocation = (lsect->section->output_offset
6060 + linker_section_ptr->offset
6061 - lsect->hole_offset
6062 - lsect->sym_offset);
6064 #ifdef DEBUG
6065 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6066 lsect->name, (long)relocation, (long)relocation);
6067 #endif
6069 /* Subtract out the addend, because it will get added back in by the normal
6070 processing. */
6071 return relocation - linker_section_ptr->addend;
6074 /* Garbage collect unused sections. */
6076 static boolean elf_gc_mark
6077 PARAMS ((struct bfd_link_info *info, asection *sec,
6078 asection * (*gc_mark_hook)
6079 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6080 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6082 static boolean elf_gc_sweep
6083 PARAMS ((struct bfd_link_info *info,
6084 boolean (*gc_sweep_hook)
6085 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6086 const Elf_Internal_Rela *relocs))));
6088 static boolean elf_gc_sweep_symbol
6089 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6091 static boolean elf_gc_allocate_got_offsets
6092 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6094 static boolean elf_gc_propagate_vtable_entries_used
6095 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6097 static boolean elf_gc_smash_unused_vtentry_relocs
6098 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6100 /* The mark phase of garbage collection. For a given section, mark
6101 it, and all the sections which define symbols to which it refers. */
6103 static boolean
6104 elf_gc_mark (info, sec, gc_mark_hook)
6105 struct bfd_link_info *info;
6106 asection *sec;
6107 asection * (*gc_mark_hook)
6108 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6109 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6111 boolean ret = true;
6113 sec->gc_mark = 1;
6115 /* Look through the section relocs. */
6117 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6119 Elf_Internal_Rela *relstart, *rel, *relend;
6120 Elf_Internal_Shdr *symtab_hdr;
6121 struct elf_link_hash_entry **sym_hashes;
6122 size_t nlocsyms;
6123 size_t extsymoff;
6124 Elf_External_Sym *locsyms, *freesyms = NULL;
6125 bfd *input_bfd = sec->owner;
6126 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6128 /* GCFIXME: how to arrange so that relocs and symbols are not
6129 reread continually? */
6131 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6132 sym_hashes = elf_sym_hashes (input_bfd);
6134 /* Read the local symbols. */
6135 if (elf_bad_symtab (input_bfd))
6137 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6138 extsymoff = 0;
6140 else
6141 extsymoff = nlocsyms = symtab_hdr->sh_info;
6142 if (symtab_hdr->contents)
6143 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6144 else if (nlocsyms == 0)
6145 locsyms = NULL;
6146 else
6148 locsyms = freesyms =
6149 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6150 if (freesyms == NULL
6151 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6152 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6153 nlocsyms, input_bfd)
6154 != nlocsyms * sizeof (Elf_External_Sym)))
6156 ret = false;
6157 goto out1;
6161 /* Read the relocations. */
6162 relstart = (NAME(_bfd_elf,link_read_relocs)
6163 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6164 info->keep_memory));
6165 if (relstart == NULL)
6167 ret = false;
6168 goto out1;
6170 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6172 for (rel = relstart; rel < relend; rel++)
6174 unsigned long r_symndx;
6175 asection *rsec;
6176 struct elf_link_hash_entry *h;
6177 Elf_Internal_Sym s;
6179 r_symndx = ELF_R_SYM (rel->r_info);
6180 if (r_symndx == 0)
6181 continue;
6183 if (elf_bad_symtab (sec->owner))
6185 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6186 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6187 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6188 else
6190 h = sym_hashes[r_symndx - extsymoff];
6191 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6194 else if (r_symndx >= nlocsyms)
6196 h = sym_hashes[r_symndx - extsymoff];
6197 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6199 else
6201 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6202 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6205 if (rsec && !rsec->gc_mark)
6206 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6208 ret = false;
6209 goto out2;
6213 out2:
6214 if (!info->keep_memory)
6215 free (relstart);
6216 out1:
6217 if (freesyms)
6218 free (freesyms);
6221 return ret;
6224 /* The sweep phase of garbage collection. Remove all garbage sections. */
6226 static boolean
6227 elf_gc_sweep (info, gc_sweep_hook)
6228 struct bfd_link_info *info;
6229 boolean (*gc_sweep_hook)
6230 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6231 const Elf_Internal_Rela *relocs));
6233 bfd *sub;
6235 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6237 asection *o;
6239 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6240 continue;
6242 for (o = sub->sections; o != NULL; o = o->next)
6244 /* Keep special sections. Keep .debug sections. */
6245 if ((o->flags & SEC_LINKER_CREATED)
6246 || (o->flags & SEC_DEBUGGING))
6247 o->gc_mark = 1;
6249 if (o->gc_mark)
6250 continue;
6252 /* Skip sweeping sections already excluded. */
6253 if (o->flags & SEC_EXCLUDE)
6254 continue;
6256 /* Since this is early in the link process, it is simple
6257 to remove a section from the output. */
6258 o->flags |= SEC_EXCLUDE;
6260 /* But we also have to update some of the relocation
6261 info we collected before. */
6262 if (gc_sweep_hook
6263 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6265 Elf_Internal_Rela *internal_relocs;
6266 boolean r;
6268 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6269 (o->owner, o, NULL, NULL, info->keep_memory));
6270 if (internal_relocs == NULL)
6271 return false;
6273 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
6275 if (!info->keep_memory)
6276 free (internal_relocs);
6278 if (!r)
6279 return false;
6284 /* Remove the symbols that were in the swept sections from the dynamic
6285 symbol table. GCFIXME: Anyone know how to get them out of the
6286 static symbol table as well? */
6288 int i = 0;
6290 elf_link_hash_traverse (elf_hash_table (info),
6291 elf_gc_sweep_symbol,
6292 (PTR) &i);
6294 elf_hash_table (info)->dynsymcount = i;
6297 return true;
6300 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6302 static boolean
6303 elf_gc_sweep_symbol (h, idxptr)
6304 struct elf_link_hash_entry *h;
6305 PTR idxptr;
6307 int *idx = (int *) idxptr;
6309 if (h->dynindx != -1
6310 && ((h->root.type != bfd_link_hash_defined
6311 && h->root.type != bfd_link_hash_defweak)
6312 || h->root.u.def.section->gc_mark))
6313 h->dynindx = (*idx)++;
6315 return true;
6318 /* Propogate collected vtable information. This is called through
6319 elf_link_hash_traverse. */
6321 static boolean
6322 elf_gc_propagate_vtable_entries_used (h, okp)
6323 struct elf_link_hash_entry *h;
6324 PTR okp;
6326 /* Those that are not vtables. */
6327 if (h->vtable_parent == NULL)
6328 return true;
6330 /* Those vtables that do not have parents, we cannot merge. */
6331 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6332 return true;
6334 /* If we've already been done, exit. */
6335 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6336 return true;
6338 /* Make sure the parent's table is up to date. */
6339 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6341 if (h->vtable_entries_used == NULL)
6343 /* None of this table's entries were referenced. Re-use the
6344 parent's table. */
6345 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6346 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6348 else
6350 size_t n;
6351 boolean *cu, *pu;
6353 /* Or the parent's entries into ours. */
6354 cu = h->vtable_entries_used;
6355 cu[-1] = true;
6356 pu = h->vtable_parent->vtable_entries_used;
6357 if (pu != NULL)
6359 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6360 while (--n != 0)
6362 if (*pu) *cu = true;
6363 pu++, cu++;
6368 return true;
6371 static boolean
6372 elf_gc_smash_unused_vtentry_relocs (h, okp)
6373 struct elf_link_hash_entry *h;
6374 PTR okp;
6376 asection *sec;
6377 bfd_vma hstart, hend;
6378 Elf_Internal_Rela *relstart, *relend, *rel;
6379 struct elf_backend_data *bed;
6381 /* Take care of both those symbols that do not describe vtables as
6382 well as those that are not loaded. */
6383 if (h->vtable_parent == NULL)
6384 return true;
6386 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6387 || h->root.type == bfd_link_hash_defweak);
6389 sec = h->root.u.def.section;
6390 hstart = h->root.u.def.value;
6391 hend = hstart + h->size;
6393 relstart = (NAME(_bfd_elf,link_read_relocs)
6394 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6395 if (!relstart)
6396 return *(boolean *)okp = false;
6397 bed = get_elf_backend_data (sec->owner);
6398 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6400 for (rel = relstart; rel < relend; ++rel)
6401 if (rel->r_offset >= hstart && rel->r_offset < hend)
6403 /* If the entry is in use, do nothing. */
6404 if (h->vtable_entries_used
6405 && (rel->r_offset - hstart) < h->vtable_entries_size)
6407 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6408 if (h->vtable_entries_used[entry])
6409 continue;
6411 /* Otherwise, kill it. */
6412 rel->r_offset = rel->r_info = rel->r_addend = 0;
6415 return true;
6418 /* Do mark and sweep of unused sections. */
6420 boolean
6421 elf_gc_sections (abfd, info)
6422 bfd *abfd;
6423 struct bfd_link_info *info;
6425 boolean ok = true;
6426 bfd *sub;
6427 asection * (*gc_mark_hook)
6428 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6429 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6431 if (!get_elf_backend_data (abfd)->can_gc_sections
6432 || info->relocateable || info->emitrelocations
6433 || elf_hash_table (info)->dynamic_sections_created)
6434 return true;
6436 /* Apply transitive closure to the vtable entry usage info. */
6437 elf_link_hash_traverse (elf_hash_table (info),
6438 elf_gc_propagate_vtable_entries_used,
6439 (PTR) &ok);
6440 if (!ok)
6441 return false;
6443 /* Kill the vtable relocations that were not used. */
6444 elf_link_hash_traverse (elf_hash_table (info),
6445 elf_gc_smash_unused_vtentry_relocs,
6446 (PTR) &ok);
6447 if (!ok)
6448 return false;
6450 /* Grovel through relocs to find out who stays ... */
6452 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6453 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6455 asection *o;
6457 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6458 continue;
6460 for (o = sub->sections; o != NULL; o = o->next)
6462 if (o->flags & SEC_KEEP)
6463 if (!elf_gc_mark (info, o, gc_mark_hook))
6464 return false;
6468 /* ... and mark SEC_EXCLUDE for those that go. */
6469 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6470 return false;
6472 return true;
6475 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6477 boolean
6478 elf_gc_record_vtinherit (abfd, sec, h, offset)
6479 bfd *abfd;
6480 asection *sec;
6481 struct elf_link_hash_entry *h;
6482 bfd_vma offset;
6484 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6485 struct elf_link_hash_entry **search, *child;
6486 bfd_size_type extsymcount;
6488 /* The sh_info field of the symtab header tells us where the
6489 external symbols start. We don't care about the local symbols at
6490 this point. */
6491 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6492 if (!elf_bad_symtab (abfd))
6493 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6495 sym_hashes = elf_sym_hashes (abfd);
6496 sym_hashes_end = sym_hashes + extsymcount;
6498 /* Hunt down the child symbol, which is in this section at the same
6499 offset as the relocation. */
6500 for (search = sym_hashes; search != sym_hashes_end; ++search)
6502 if ((child = *search) != NULL
6503 && (child->root.type == bfd_link_hash_defined
6504 || child->root.type == bfd_link_hash_defweak)
6505 && child->root.u.def.section == sec
6506 && child->root.u.def.value == offset)
6507 goto win;
6510 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6511 bfd_get_filename (abfd), sec->name,
6512 (unsigned long)offset);
6513 bfd_set_error (bfd_error_invalid_operation);
6514 return false;
6516 win:
6517 if (!h)
6519 /* This *should* only be the absolute section. It could potentially
6520 be that someone has defined a non-global vtable though, which
6521 would be bad. It isn't worth paging in the local symbols to be
6522 sure though; that case should simply be handled by the assembler. */
6524 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6526 else
6527 child->vtable_parent = h;
6529 return true;
6532 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6534 boolean
6535 elf_gc_record_vtentry (abfd, sec, h, addend)
6536 bfd *abfd ATTRIBUTE_UNUSED;
6537 asection *sec ATTRIBUTE_UNUSED;
6538 struct elf_link_hash_entry *h;
6539 bfd_vma addend;
6541 if (addend >= h->vtable_entries_size)
6543 size_t size, bytes;
6544 boolean *ptr = h->vtable_entries_used;
6546 /* While the symbol is undefined, we have to be prepared to handle
6547 a zero size. */
6548 if (h->root.type == bfd_link_hash_undefined)
6549 size = addend;
6550 else
6552 size = h->size;
6553 if (size < addend)
6555 /* Oops! We've got a reference past the defined end of
6556 the table. This is probably a bug -- shall we warn? */
6557 size = addend;
6561 /* Allocate one extra entry for use as a "done" flag for the
6562 consolidation pass. */
6563 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6565 if (ptr)
6567 ptr = bfd_realloc (ptr - 1, bytes);
6569 if (ptr != NULL)
6571 size_t oldbytes;
6573 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6574 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6577 else
6578 ptr = bfd_zmalloc (bytes);
6580 if (ptr == NULL)
6581 return false;
6583 /* And arrange for that done flag to be at index -1. */
6584 h->vtable_entries_used = ptr + 1;
6585 h->vtable_entries_size = size;
6588 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6590 return true;
6593 /* And an accompanying bit to work out final got entry offsets once
6594 we're done. Should be called from final_link. */
6596 boolean
6597 elf_gc_common_finalize_got_offsets (abfd, info)
6598 bfd *abfd;
6599 struct bfd_link_info *info;
6601 bfd *i;
6602 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6603 bfd_vma gotoff;
6605 /* The GOT offset is relative to the .got section, but the GOT header is
6606 put into the .got.plt section, if the backend uses it. */
6607 if (bed->want_got_plt)
6608 gotoff = 0;
6609 else
6610 gotoff = bed->got_header_size;
6612 /* Do the local .got entries first. */
6613 for (i = info->input_bfds; i; i = i->link_next)
6615 bfd_signed_vma *local_got;
6616 bfd_size_type j, locsymcount;
6617 Elf_Internal_Shdr *symtab_hdr;
6619 if (bfd_get_flavour (i) != bfd_target_elf_flavour)
6620 continue;
6622 local_got = elf_local_got_refcounts (i);
6623 if (!local_got)
6624 continue;
6626 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6627 if (elf_bad_symtab (i))
6628 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6629 else
6630 locsymcount = symtab_hdr->sh_info;
6632 for (j = 0; j < locsymcount; ++j)
6634 if (local_got[j] > 0)
6636 local_got[j] = gotoff;
6637 gotoff += ARCH_SIZE / 8;
6639 else
6640 local_got[j] = (bfd_vma) -1;
6644 /* Then the global .got entries. .plt refcounts are handled by
6645 adjust_dynamic_symbol */
6646 elf_link_hash_traverse (elf_hash_table (info),
6647 elf_gc_allocate_got_offsets,
6648 (PTR) &gotoff);
6649 return true;
6652 /* We need a special top-level link routine to convert got reference counts
6653 to real got offsets. */
6655 static boolean
6656 elf_gc_allocate_got_offsets (h, offarg)
6657 struct elf_link_hash_entry *h;
6658 PTR offarg;
6660 bfd_vma *off = (bfd_vma *) offarg;
6662 if (h->got.refcount > 0)
6664 h->got.offset = off[0];
6665 off[0] += ARCH_SIZE / 8;
6667 else
6668 h->got.offset = (bfd_vma) -1;
6670 return true;
6673 /* Many folk need no more in the way of final link than this, once
6674 got entry reference counting is enabled. */
6676 boolean
6677 elf_gc_common_final_link (abfd, info)
6678 bfd *abfd;
6679 struct bfd_link_info *info;
6681 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6682 return false;
6684 /* Invoke the regular ELF backend linker to do all the work. */
6685 return elf_bfd_final_link (abfd, info);
6688 /* This function will be called though elf_link_hash_traverse to store
6689 all hash value of the exported symbols in an array. */
6691 static boolean
6692 elf_collect_hash_codes (h, data)
6693 struct elf_link_hash_entry *h;
6694 PTR data;
6696 unsigned long **valuep = (unsigned long **) data;
6697 const char *name;
6698 char *p;
6699 unsigned long ha;
6700 char *alc = NULL;
6702 /* Ignore indirect symbols. These are added by the versioning code. */
6703 if (h->dynindx == -1)
6704 return true;
6706 name = h->root.root.string;
6707 p = strchr (name, ELF_VER_CHR);
6708 if (p != NULL)
6710 alc = bfd_malloc (p - name + 1);
6711 memcpy (alc, name, p - name);
6712 alc[p - name] = '\0';
6713 name = alc;
6716 /* Compute the hash value. */
6717 ha = bfd_elf_hash (name);
6719 /* Store the found hash value in the array given as the argument. */
6720 *(*valuep)++ = ha;
6722 /* And store it in the struct so that we can put it in the hash table
6723 later. */
6724 h->elf_hash_value = ha;
6726 if (alc != NULL)
6727 free (alc);
6729 return true;