Applied Mumit Kha's patch to tweak dll production code.
[binutils.git] / bfd / elflink.h
blobf15c693422c3fe84f7339a4cdcdeb4bdaa3aac70
1 /* ELF linker support.
2 Copyright 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20 /* ELF linker code. */
22 /* This struct is used to pass information to routines called via
23 elf_link_hash_traverse which must return failure. */
25 struct elf_info_failed
27 boolean failed;
28 struct bfd_link_info *info;
31 static boolean elf_link_add_object_symbols
32 PARAMS ((bfd *, struct bfd_link_info *));
33 static boolean elf_link_add_archive_symbols
34 PARAMS ((bfd *, struct bfd_link_info *));
35 static boolean elf_merge_symbol
36 PARAMS ((bfd *, struct bfd_link_info *, const char *, Elf_Internal_Sym *,
37 asection **, bfd_vma *, struct elf_link_hash_entry **,
38 boolean *, boolean *, boolean *));
39 static boolean elf_export_symbol
40 PARAMS ((struct elf_link_hash_entry *, PTR));
41 static boolean elf_fix_symbol_flags
42 PARAMS ((struct elf_link_hash_entry *, struct elf_info_failed *));
43 static boolean elf_adjust_dynamic_symbol
44 PARAMS ((struct elf_link_hash_entry *, PTR));
45 static boolean elf_link_find_version_dependencies
46 PARAMS ((struct elf_link_hash_entry *, PTR));
47 static boolean elf_link_find_version_dependencies
48 PARAMS ((struct elf_link_hash_entry *, PTR));
49 static boolean elf_link_assign_sym_version
50 PARAMS ((struct elf_link_hash_entry *, PTR));
51 static boolean elf_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;
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. */
361 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
362 if (element == (bfd *) NULL)
363 goto error_return;
365 if (! bfd_check_format (element, bfd_object))
366 goto error_return;
368 /* Doublecheck that we have not included this object
369 already--it should be impossible, but there may be
370 something wrong with the archive. */
371 if (element->archive_pass != 0)
373 bfd_set_error (bfd_error_bad_value);
374 goto error_return;
376 element->archive_pass = 1;
378 undefs_tail = info->hash->undefs_tail;
380 if (! (*info->callbacks->add_archive_element) (info, element,
381 symdef->name))
382 goto error_return;
383 if (! elf_link_add_object_symbols (element, info))
384 goto error_return;
386 /* If there are any new undefined symbols, we need to make
387 another pass through the archive in order to see whether
388 they can be defined. FIXME: This isn't perfect, because
389 common symbols wind up on undefs_tail and because an
390 undefined symbol which is defined later on in this pass
391 does not require another pass. This isn't a bug, but it
392 does make the code less efficient than it could be. */
393 if (undefs_tail != info->hash->undefs_tail)
394 loop = true;
396 /* Look backward to mark all symbols from this object file
397 which we have already seen in this pass. */
398 mark = i;
401 included[mark] = true;
402 if (mark == 0)
403 break;
404 --mark;
406 while (symdefs[mark].file_offset == symdef->file_offset);
408 /* We mark subsequent symbols from this object file as we go
409 on through the loop. */
410 last = symdef->file_offset;
413 while (loop);
415 free (defined);
416 free (included);
418 return true;
420 error_return:
421 if (defined != (boolean *) NULL)
422 free (defined);
423 if (included != (boolean *) NULL)
424 free (included);
425 return false;
428 /* This function is called when we want to define a new symbol. It
429 handles the various cases which arise when we find a definition in
430 a dynamic object, or when there is already a definition in a
431 dynamic object. The new symbol is described by NAME, SYM, PSEC,
432 and PVALUE. We set SYM_HASH to the hash table entry. We set
433 OVERRIDE if the old symbol is overriding a new definition. We set
434 TYPE_CHANGE_OK if it is OK for the type to change. We set
435 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
436 change, we mean that we shouldn't warn if the type or size does
437 change. */
439 static boolean
440 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
441 override, type_change_ok, size_change_ok)
442 bfd *abfd;
443 struct bfd_link_info *info;
444 const char *name;
445 Elf_Internal_Sym *sym;
446 asection **psec;
447 bfd_vma *pvalue;
448 struct elf_link_hash_entry **sym_hash;
449 boolean *override;
450 boolean *type_change_ok;
451 boolean *size_change_ok;
453 asection *sec;
454 struct elf_link_hash_entry *h;
455 int bind;
456 bfd *oldbfd;
457 boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
459 *override = false;
461 sec = *psec;
462 bind = ELF_ST_BIND (sym->st_info);
464 if (! bfd_is_und_section (sec))
465 h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
466 else
467 h = ((struct elf_link_hash_entry *)
468 bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
469 if (h == NULL)
470 return false;
471 *sym_hash = h;
473 /* This code is for coping with dynamic objects, and is only useful
474 if we are doing an ELF link. */
475 if (info->hash->creator != abfd->xvec)
476 return true;
478 /* For merging, we only care about real symbols. */
480 while (h->root.type == bfd_link_hash_indirect
481 || h->root.type == bfd_link_hash_warning)
482 h = (struct elf_link_hash_entry *) h->root.u.i.link;
484 /* If we just created the symbol, mark it as being an ELF symbol.
485 Other than that, there is nothing to do--there is no merge issue
486 with a newly defined symbol--so we just return. */
488 if (h->root.type == bfd_link_hash_new)
490 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
491 return true;
494 /* OLDBFD is a BFD associated with the existing symbol. */
496 switch (h->root.type)
498 default:
499 oldbfd = NULL;
500 break;
502 case bfd_link_hash_undefined:
503 case bfd_link_hash_undefweak:
504 oldbfd = h->root.u.undef.abfd;
505 break;
507 case bfd_link_hash_defined:
508 case bfd_link_hash_defweak:
509 oldbfd = h->root.u.def.section->owner;
510 break;
512 case bfd_link_hash_common:
513 oldbfd = h->root.u.c.p->section->owner;
514 break;
517 /* In cases involving weak versioned symbols, we may wind up trying
518 to merge a symbol with itself. Catch that here, to avoid the
519 confusion that results if we try to override a symbol with
520 itself. The additional tests catch cases like
521 _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
522 dynamic object, which we do want to handle here. */
523 if (abfd == oldbfd
524 && ((abfd->flags & DYNAMIC) == 0
525 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))
526 return true;
528 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
529 respectively, is from a dynamic object. */
531 if ((abfd->flags & DYNAMIC) != 0)
532 newdyn = true;
533 else
534 newdyn = false;
536 if (oldbfd != NULL)
537 olddyn = (oldbfd->flags & DYNAMIC) != 0;
538 else
540 asection *hsec;
542 /* This code handles the special SHN_MIPS_{TEXT,DATA} section
543 indices used by MIPS ELF. */
544 switch (h->root.type)
546 default:
547 hsec = NULL;
548 break;
550 case bfd_link_hash_defined:
551 case bfd_link_hash_defweak:
552 hsec = h->root.u.def.section;
553 break;
555 case bfd_link_hash_common:
556 hsec = h->root.u.c.p->section;
557 break;
560 if (hsec == NULL)
561 olddyn = false;
562 else
563 olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0;
566 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
567 respectively, appear to be a definition rather than reference. */
569 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
570 newdef = false;
571 else
572 newdef = true;
574 if (h->root.type == bfd_link_hash_undefined
575 || h->root.type == bfd_link_hash_undefweak
576 || h->root.type == bfd_link_hash_common)
577 olddef = false;
578 else
579 olddef = true;
581 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
582 symbol, respectively, appears to be a common symbol in a dynamic
583 object. If a symbol appears in an uninitialized section, and is
584 not weak, and is not a function, then it may be a common symbol
585 which was resolved when the dynamic object was created. We want
586 to treat such symbols specially, because they raise special
587 considerations when setting the symbol size: if the symbol
588 appears as a common symbol in a regular object, and the size in
589 the regular object is larger, we must make sure that we use the
590 larger size. This problematic case can always be avoided in C,
591 but it must be handled correctly when using Fortran shared
592 libraries.
594 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
595 likewise for OLDDYNCOMMON and OLDDEF.
597 Note that this test is just a heuristic, and that it is quite
598 possible to have an uninitialized symbol in a shared object which
599 is really a definition, rather than a common symbol. This could
600 lead to some minor confusion when the symbol really is a common
601 symbol in some regular object. However, I think it will be
602 harmless. */
604 if (newdyn
605 && newdef
606 && (sec->flags & SEC_ALLOC) != 0
607 && (sec->flags & SEC_LOAD) == 0
608 && sym->st_size > 0
609 && bind != STB_WEAK
610 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
611 newdyncommon = true;
612 else
613 newdyncommon = false;
615 if (olddyn
616 && olddef
617 && h->root.type == bfd_link_hash_defined
618 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
619 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
620 && (h->root.u.def.section->flags & SEC_LOAD) == 0
621 && h->size > 0
622 && h->type != STT_FUNC)
623 olddyncommon = true;
624 else
625 olddyncommon = false;
627 /* It's OK to change the type if either the existing symbol or the
628 new symbol is weak. */
630 if (h->root.type == bfd_link_hash_defweak
631 || h->root.type == bfd_link_hash_undefweak
632 || bind == STB_WEAK)
633 *type_change_ok = true;
635 /* It's OK to change the size if either the existing symbol or the
636 new symbol is weak, or if the old symbol is undefined. */
638 if (*type_change_ok
639 || h->root.type == bfd_link_hash_undefined)
640 *size_change_ok = true;
642 /* If both the old and the new symbols look like common symbols in a
643 dynamic object, set the size of the symbol to the larger of the
644 two. */
646 if (olddyncommon
647 && newdyncommon
648 && sym->st_size != h->size)
650 /* Since we think we have two common symbols, issue a multiple
651 common warning if desired. Note that we only warn if the
652 size is different. If the size is the same, we simply let
653 the old symbol override the new one as normally happens with
654 symbols defined in dynamic objects. */
656 if (! ((*info->callbacks->multiple_common)
657 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
658 h->size, abfd, bfd_link_hash_common, sym->st_size)))
659 return false;
661 if (sym->st_size > h->size)
662 h->size = sym->st_size;
664 *size_change_ok = true;
667 /* If we are looking at a dynamic object, and we have found a
668 definition, we need to see if the symbol was already defined by
669 some other object. If so, we want to use the existing
670 definition, and we do not want to report a multiple symbol
671 definition error; we do this by clobbering *PSEC to be
672 bfd_und_section_ptr.
674 We treat a common symbol as a definition if the symbol in the
675 shared library is a function, since common symbols always
676 represent variables; this can cause confusion in principle, but
677 any such confusion would seem to indicate an erroneous program or
678 shared library. We also permit a common symbol in a regular
679 object to override a weak symbol in a shared object.
681 We prefer a non-weak definition in a shared library to a weak
682 definition in the executable. */
684 if (newdyn
685 && newdef
686 && (olddef
687 || (h->root.type == bfd_link_hash_common
688 && (bind == STB_WEAK
689 || ELF_ST_TYPE (sym->st_info) == STT_FUNC)))
690 && (h->root.type != bfd_link_hash_defweak
691 || bind == STB_WEAK))
693 *override = true;
694 newdef = false;
695 newdyncommon = false;
697 *psec = sec = bfd_und_section_ptr;
698 *size_change_ok = true;
700 /* If we get here when the old symbol is a common symbol, then
701 we are explicitly letting it override a weak symbol or
702 function in a dynamic object, and we don't want to warn about
703 a type change. If the old symbol is a defined symbol, a type
704 change warning may still be appropriate. */
706 if (h->root.type == bfd_link_hash_common)
707 *type_change_ok = true;
710 /* Handle the special case of an old common symbol merging with a
711 new symbol which looks like a common symbol in a shared object.
712 We change *PSEC and *PVALUE to make the new symbol look like a
713 common symbol, and let _bfd_generic_link_add_one_symbol will do
714 the right thing. */
716 if (newdyncommon
717 && h->root.type == bfd_link_hash_common)
719 *override = true;
720 newdef = false;
721 newdyncommon = false;
722 *pvalue = sym->st_size;
723 *psec = sec = bfd_com_section_ptr;
724 *size_change_ok = true;
727 /* If the old symbol is from a dynamic object, and the new symbol is
728 a definition which is not from a dynamic object, then the new
729 symbol overrides the old symbol. Symbols from regular files
730 always take precedence over symbols from dynamic objects, even if
731 they are defined after the dynamic object in the link.
733 As above, we again permit a common symbol in a regular object to
734 override a definition in a shared object if the shared object
735 symbol is a function or is weak.
737 As above, we permit a non-weak definition in a shared object to
738 override a weak definition in a regular object. */
740 if (! newdyn
741 && (newdef
742 || (bfd_is_com_section (sec)
743 && (h->root.type == bfd_link_hash_defweak
744 || h->type == STT_FUNC)))
745 && olddyn
746 && olddef
747 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
748 && (bind != STB_WEAK
749 || h->root.type == bfd_link_hash_defweak))
751 /* Change the hash table entry to undefined, and let
752 _bfd_generic_link_add_one_symbol do the right thing with the
753 new definition. */
755 h->root.type = bfd_link_hash_undefined;
756 h->root.u.undef.abfd = h->root.u.def.section->owner;
757 *size_change_ok = true;
759 olddef = false;
760 olddyncommon = false;
762 /* We again permit a type change when a common symbol may be
763 overriding a function. */
765 if (bfd_is_com_section (sec))
766 *type_change_ok = true;
768 /* This union may have been set to be non-NULL when this symbol
769 was seen in a dynamic object. We must force the union to be
770 NULL, so that it is correct for a regular symbol. */
772 h->verinfo.vertree = NULL;
774 /* In this special case, if H is the target of an indirection,
775 we want the caller to frob with H rather than with the
776 indirect symbol. That will permit the caller to redefine the
777 target of the indirection, rather than the indirect symbol
778 itself. FIXME: This will break the -y option if we store a
779 symbol with a different name. */
780 *sym_hash = h;
783 /* Handle the special case of a new common symbol merging with an
784 old symbol that looks like it might be a common symbol defined in
785 a shared object. Note that we have already handled the case in
786 which a new common symbol should simply override the definition
787 in the shared library. */
789 if (! newdyn
790 && bfd_is_com_section (sec)
791 && olddyncommon)
793 /* It would be best if we could set the hash table entry to a
794 common symbol, but we don't know what to use for the section
795 or the alignment. */
796 if (! ((*info->callbacks->multiple_common)
797 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
798 h->size, abfd, bfd_link_hash_common, sym->st_size)))
799 return false;
801 /* If the predumed common symbol in the dynamic object is
802 larger, pretend that the new symbol has its size. */
804 if (h->size > *pvalue)
805 *pvalue = h->size;
807 /* FIXME: We no longer know the alignment required by the symbol
808 in the dynamic object, so we just wind up using the one from
809 the regular object. */
811 olddef = false;
812 olddyncommon = false;
814 h->root.type = bfd_link_hash_undefined;
815 h->root.u.undef.abfd = h->root.u.def.section->owner;
817 *size_change_ok = true;
818 *type_change_ok = true;
820 h->verinfo.vertree = NULL;
823 /* Handle the special case of a weak definition in a regular object
824 followed by a non-weak definition in a shared object. In this
825 case, we prefer the definition in the shared object. */
826 if (olddef
827 && h->root.type == bfd_link_hash_defweak
828 && newdef
829 && newdyn
830 && bind != STB_WEAK)
832 /* To make this work we have to frob the flags so that the rest
833 of the code does not think we are using the regular
834 definition. */
835 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
836 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
837 else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
838 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
839 h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR
840 | ELF_LINK_HASH_DEF_DYNAMIC);
842 /* If H is the target of an indirection, we want the caller to
843 use H rather than the indirect symbol. Otherwise if we are
844 defining a new indirect symbol we will wind up attaching it
845 to the entry we are overriding. */
846 *sym_hash = h;
849 /* Handle the special case of a non-weak definition in a shared
850 object followed by a weak definition in a regular object. In
851 this case we prefer to definition in the shared object. To make
852 this work we have to tell the caller to not treat the new symbol
853 as a definition. */
854 if (olddef
855 && olddyn
856 && h->root.type != bfd_link_hash_defweak
857 && newdef
858 && ! newdyn
859 && bind == STB_WEAK)
860 *override = true;
862 return true;
865 /* Add symbols from an ELF object file to the linker hash table. */
867 static boolean
868 elf_link_add_object_symbols (abfd, info)
869 bfd *abfd;
870 struct bfd_link_info *info;
872 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
873 const Elf_Internal_Sym *,
874 const char **, flagword *,
875 asection **, bfd_vma *));
876 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
877 asection *, const Elf_Internal_Rela *));
878 boolean collect;
879 Elf_Internal_Shdr *hdr;
880 size_t symcount;
881 size_t extsymcount;
882 size_t extsymoff;
883 Elf_External_Sym *buf = NULL;
884 struct elf_link_hash_entry **sym_hash;
885 boolean dynamic;
886 bfd_byte *dynver = NULL;
887 Elf_External_Versym *extversym = NULL;
888 Elf_External_Versym *ever;
889 Elf_External_Dyn *dynbuf = NULL;
890 struct elf_link_hash_entry *weaks;
891 Elf_External_Sym *esym;
892 Elf_External_Sym *esymend;
894 add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
895 collect = get_elf_backend_data (abfd)->collect;
897 if ((abfd->flags & DYNAMIC) == 0)
898 dynamic = false;
899 else
901 dynamic = true;
903 /* You can't use -r against a dynamic object. Also, there's no
904 hope of using a dynamic object which does not exactly match
905 the format of the output file. */
906 if (info->relocateable || info->hash->creator != abfd->xvec)
908 bfd_set_error (bfd_error_invalid_operation);
909 goto error_return;
913 /* As a GNU extension, any input sections which are named
914 .gnu.warning.SYMBOL are treated as warning symbols for the given
915 symbol. This differs from .gnu.warning sections, which generate
916 warnings when they are included in an output file. */
917 if (! info->shared)
919 asection *s;
921 for (s = abfd->sections; s != NULL; s = s->next)
923 const char *name;
925 name = bfd_get_section_name (abfd, s);
926 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
928 char *msg;
929 bfd_size_type sz;
931 name += sizeof ".gnu.warning." - 1;
933 /* If this is a shared object, then look up the symbol
934 in the hash table. If it is there, and it is already
935 been defined, then we will not be using the entry
936 from this shared object, so we don't need to warn.
937 FIXME: If we see the definition in a regular object
938 later on, we will warn, but we shouldn't. The only
939 fix is to keep track of what warnings we are supposed
940 to emit, and then handle them all at the end of the
941 link. */
942 if (dynamic && abfd->xvec == info->hash->creator)
944 struct elf_link_hash_entry *h;
946 h = elf_link_hash_lookup (elf_hash_table (info), name,
947 false, false, true);
949 /* FIXME: What about bfd_link_hash_common? */
950 if (h != NULL
951 && (h->root.type == bfd_link_hash_defined
952 || h->root.type == bfd_link_hash_defweak))
954 /* We don't want to issue this warning. Clobber
955 the section size so that the warning does not
956 get copied into the output file. */
957 s->_raw_size = 0;
958 continue;
962 sz = bfd_section_size (abfd, s);
963 msg = (char *) bfd_alloc (abfd, sz + 1);
964 if (msg == NULL)
965 goto error_return;
967 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
968 goto error_return;
970 msg[sz] = '\0';
972 if (! (_bfd_generic_link_add_one_symbol
973 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
974 false, collect, (struct bfd_link_hash_entry **) NULL)))
975 goto error_return;
977 if (! info->relocateable)
979 /* Clobber the section size so that the warning does
980 not get copied into the output file. */
981 s->_raw_size = 0;
987 /* If this is a dynamic object, we always link against the .dynsym
988 symbol table, not the .symtab symbol table. The dynamic linker
989 will only see the .dynsym symbol table, so there is no reason to
990 look at .symtab for a dynamic object. */
992 if (! dynamic || elf_dynsymtab (abfd) == 0)
993 hdr = &elf_tdata (abfd)->symtab_hdr;
994 else
995 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
997 if (dynamic)
999 /* Read in any version definitions. */
1001 if (! _bfd_elf_slurp_version_tables (abfd))
1002 goto error_return;
1004 /* Read in the symbol versions, but don't bother to convert them
1005 to internal format. */
1006 if (elf_dynversym (abfd) != 0)
1008 Elf_Internal_Shdr *versymhdr;
1010 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
1011 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
1012 if (extversym == NULL)
1013 goto error_return;
1014 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
1015 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
1016 != versymhdr->sh_size))
1017 goto error_return;
1021 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
1023 /* The sh_info field of the symtab header tells us where the
1024 external symbols start. We don't care about the local symbols at
1025 this point. */
1026 if (elf_bad_symtab (abfd))
1028 extsymcount = symcount;
1029 extsymoff = 0;
1031 else
1033 extsymcount = symcount - hdr->sh_info;
1034 extsymoff = hdr->sh_info;
1037 buf = ((Elf_External_Sym *)
1038 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
1039 if (buf == NULL && extsymcount != 0)
1040 goto error_return;
1042 /* We store a pointer to the hash table entry for each external
1043 symbol. */
1044 sym_hash = ((struct elf_link_hash_entry **)
1045 bfd_alloc (abfd,
1046 extsymcount * sizeof (struct elf_link_hash_entry *)));
1047 if (sym_hash == NULL)
1048 goto error_return;
1049 elf_sym_hashes (abfd) = sym_hash;
1051 if (! dynamic)
1053 /* If we are creating a shared library, create all the dynamic
1054 sections immediately. We need to attach them to something,
1055 so we attach them to this BFD, provided it is the right
1056 format. FIXME: If there are no input BFD's of the same
1057 format as the output, we can't make a shared library. */
1058 if (info->shared
1059 && ! elf_hash_table (info)->dynamic_sections_created
1060 && abfd->xvec == info->hash->creator)
1062 if (! elf_link_create_dynamic_sections (abfd, info))
1063 goto error_return;
1066 else
1068 asection *s;
1069 boolean add_needed;
1070 const char *name;
1071 bfd_size_type oldsize;
1072 bfd_size_type strindex;
1074 /* Find the name to use in a DT_NEEDED entry that refers to this
1075 object. If the object has a DT_SONAME entry, we use it.
1076 Otherwise, if the generic linker stuck something in
1077 elf_dt_name, we use that. Otherwise, we just use the file
1078 name. If the generic linker put a null string into
1079 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
1080 there is a DT_SONAME entry. */
1081 add_needed = true;
1082 name = bfd_get_filename (abfd);
1083 if (elf_dt_name (abfd) != NULL)
1085 name = elf_dt_name (abfd);
1086 if (*name == '\0')
1087 add_needed = false;
1089 s = bfd_get_section_by_name (abfd, ".dynamic");
1090 if (s != NULL)
1092 Elf_External_Dyn *extdyn;
1093 Elf_External_Dyn *extdynend;
1094 int elfsec;
1095 unsigned long link;
1097 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
1098 if (dynbuf == NULL)
1099 goto error_return;
1101 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
1102 (file_ptr) 0, s->_raw_size))
1103 goto error_return;
1105 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1106 if (elfsec == -1)
1107 goto error_return;
1108 link = elf_elfsections (abfd)[elfsec]->sh_link;
1111 /* The shared libraries distributed with hpux11 have a bogus
1112 sh_link field for the ".dynamic" section. This code detects
1113 when LINK refers to a section that is not a string table and
1114 tries to find the string table for the ".dynsym" section
1115 instead. */
1116 Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[link];
1117 if (hdr->sh_type != SHT_STRTAB)
1119 asection *s = bfd_get_section_by_name (abfd, ".dynsym");
1120 int elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1121 if (elfsec == -1)
1122 goto error_return;
1123 link = elf_elfsections (abfd)[elfsec]->sh_link;
1127 extdyn = dynbuf;
1128 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
1129 for (; extdyn < extdynend; extdyn++)
1131 Elf_Internal_Dyn dyn;
1133 elf_swap_dyn_in (abfd, extdyn, &dyn);
1134 if (dyn.d_tag == DT_SONAME)
1136 name = bfd_elf_string_from_elf_section (abfd, link,
1137 dyn.d_un.d_val);
1138 if (name == NULL)
1139 goto error_return;
1141 if (dyn.d_tag == DT_NEEDED)
1143 struct bfd_link_needed_list *n, **pn;
1144 char *fnm, *anm;
1146 n = ((struct bfd_link_needed_list *)
1147 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1148 fnm = bfd_elf_string_from_elf_section (abfd, link,
1149 dyn.d_un.d_val);
1150 if (n == NULL || fnm == NULL)
1151 goto error_return;
1152 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1153 if (anm == NULL)
1154 goto error_return;
1155 strcpy (anm, fnm);
1156 n->name = anm;
1157 n->by = abfd;
1158 n->next = NULL;
1159 for (pn = &elf_hash_table (info)->needed;
1160 *pn != NULL;
1161 pn = &(*pn)->next)
1163 *pn = n;
1167 free (dynbuf);
1168 dynbuf = NULL;
1171 /* We do not want to include any of the sections in a dynamic
1172 object in the output file. We hack by simply clobbering the
1173 list of sections in the BFD. This could be handled more
1174 cleanly by, say, a new section flag; the existing
1175 SEC_NEVER_LOAD flag is not the one we want, because that one
1176 still implies that the section takes up space in the output
1177 file. */
1178 abfd->sections = NULL;
1179 abfd->section_count = 0;
1181 /* If this is the first dynamic object found in the link, create
1182 the special sections required for dynamic linking. */
1183 if (! elf_hash_table (info)->dynamic_sections_created)
1185 if (! elf_link_create_dynamic_sections (abfd, info))
1186 goto error_return;
1189 if (add_needed)
1191 /* Add a DT_NEEDED entry for this dynamic object. */
1192 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1193 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
1194 true, false);
1195 if (strindex == (bfd_size_type) -1)
1196 goto error_return;
1198 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1200 asection *sdyn;
1201 Elf_External_Dyn *dyncon, *dynconend;
1203 /* The hash table size did not change, which means that
1204 the dynamic object name was already entered. If we
1205 have already included this dynamic object in the
1206 link, just ignore it. There is no reason to include
1207 a particular dynamic object more than once. */
1208 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1209 ".dynamic");
1210 BFD_ASSERT (sdyn != NULL);
1212 dyncon = (Elf_External_Dyn *) sdyn->contents;
1213 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1214 sdyn->_raw_size);
1215 for (; dyncon < dynconend; dyncon++)
1217 Elf_Internal_Dyn dyn;
1219 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
1220 &dyn);
1221 if (dyn.d_tag == DT_NEEDED
1222 && dyn.d_un.d_val == strindex)
1224 if (buf != NULL)
1225 free (buf);
1226 if (extversym != NULL)
1227 free (extversym);
1228 return true;
1233 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1234 goto error_return;
1237 /* Save the SONAME, if there is one, because sometimes the
1238 linker emulation code will need to know it. */
1239 if (*name == '\0')
1240 name = bfd_get_filename (abfd);
1241 elf_dt_name (abfd) = name;
1244 if (bfd_seek (abfd,
1245 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
1246 SEEK_SET) != 0
1247 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
1248 != extsymcount * sizeof (Elf_External_Sym)))
1249 goto error_return;
1251 weaks = NULL;
1253 ever = extversym != NULL ? extversym + extsymoff : NULL;
1254 esymend = buf + extsymcount;
1255 for (esym = buf;
1256 esym < esymend;
1257 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1259 Elf_Internal_Sym sym;
1260 int bind;
1261 bfd_vma value;
1262 asection *sec;
1263 flagword flags;
1264 const char *name;
1265 struct elf_link_hash_entry *h;
1266 boolean definition;
1267 boolean size_change_ok, type_change_ok;
1268 boolean new_weakdef;
1269 unsigned int old_alignment;
1271 elf_swap_symbol_in (abfd, esym, &sym);
1273 flags = BSF_NO_FLAGS;
1274 sec = NULL;
1275 value = sym.st_value;
1276 *sym_hash = NULL;
1278 bind = ELF_ST_BIND (sym.st_info);
1279 if (bind == STB_LOCAL)
1281 /* This should be impossible, since ELF requires that all
1282 global symbols follow all local symbols, and that sh_info
1283 point to the first global symbol. Unfortunatealy, Irix 5
1284 screws this up. */
1285 continue;
1287 else if (bind == STB_GLOBAL)
1289 if (sym.st_shndx != SHN_UNDEF
1290 && sym.st_shndx != SHN_COMMON)
1291 flags = BSF_GLOBAL;
1292 else
1293 flags = 0;
1295 else if (bind == STB_WEAK)
1296 flags = BSF_WEAK;
1297 else
1299 /* Leave it up to the processor backend. */
1302 if (sym.st_shndx == SHN_UNDEF)
1303 sec = bfd_und_section_ptr;
1304 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1306 sec = section_from_elf_index (abfd, sym.st_shndx);
1307 if (sec == NULL)
1308 sec = bfd_abs_section_ptr;
1309 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1310 value -= sec->vma;
1312 else if (sym.st_shndx == SHN_ABS)
1313 sec = bfd_abs_section_ptr;
1314 else if (sym.st_shndx == SHN_COMMON)
1316 sec = bfd_com_section_ptr;
1317 /* What ELF calls the size we call the value. What ELF
1318 calls the value we call the alignment. */
1319 value = sym.st_size;
1321 else
1323 /* Leave it up to the processor backend. */
1326 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1327 if (name == (const char *) NULL)
1328 goto error_return;
1330 if (add_symbol_hook)
1332 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1333 &value))
1334 goto error_return;
1336 /* The hook function sets the name to NULL if this symbol
1337 should be skipped for some reason. */
1338 if (name == (const char *) NULL)
1339 continue;
1342 /* Sanity check that all possibilities were handled. */
1343 if (sec == (asection *) NULL)
1345 bfd_set_error (bfd_error_bad_value);
1346 goto error_return;
1349 if (bfd_is_und_section (sec)
1350 || bfd_is_com_section (sec))
1351 definition = false;
1352 else
1353 definition = true;
1355 size_change_ok = false;
1356 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1357 old_alignment = 0;
1358 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1360 Elf_Internal_Versym iver;
1361 unsigned int vernum = 0;
1362 boolean override;
1364 if (ever != NULL)
1366 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1367 vernum = iver.vs_vers & VERSYM_VERSION;
1369 /* If this is a hidden symbol, or if it is not version
1370 1, we append the version name to the symbol name.
1371 However, we do not modify a non-hidden absolute
1372 symbol, because it might be the version symbol
1373 itself. FIXME: What if it isn't? */
1374 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1375 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1377 const char *verstr;
1378 int namelen, newlen;
1379 char *newname, *p;
1381 if (sym.st_shndx != SHN_UNDEF)
1383 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1385 (*_bfd_error_handler)
1386 (_("%s: %s: invalid version %u (max %d)"),
1387 bfd_get_filename (abfd), name, vernum,
1388 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1389 bfd_set_error (bfd_error_bad_value);
1390 goto error_return;
1392 else if (vernum > 1)
1393 verstr =
1394 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1395 else
1396 verstr = "";
1398 else
1400 /* We cannot simply test for the number of
1401 entries in the VERNEED section since the
1402 numbers for the needed versions do not start
1403 at 0. */
1404 Elf_Internal_Verneed *t;
1406 verstr = NULL;
1407 for (t = elf_tdata (abfd)->verref;
1408 t != NULL;
1409 t = t->vn_nextref)
1411 Elf_Internal_Vernaux *a;
1413 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1415 if (a->vna_other == vernum)
1417 verstr = a->vna_nodename;
1418 break;
1421 if (a != NULL)
1422 break;
1424 if (verstr == NULL)
1426 (*_bfd_error_handler)
1427 (_("%s: %s: invalid needed version %d"),
1428 bfd_get_filename (abfd), name, vernum);
1429 bfd_set_error (bfd_error_bad_value);
1430 goto error_return;
1434 namelen = strlen (name);
1435 newlen = namelen + strlen (verstr) + 2;
1436 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1437 ++newlen;
1439 newname = (char *) bfd_alloc (abfd, newlen);
1440 if (newname == NULL)
1441 goto error_return;
1442 strcpy (newname, name);
1443 p = newname + namelen;
1444 *p++ = ELF_VER_CHR;
1445 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1446 *p++ = ELF_VER_CHR;
1447 strcpy (p, verstr);
1449 name = newname;
1453 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1454 sym_hash, &override, &type_change_ok,
1455 &size_change_ok))
1456 goto error_return;
1458 if (override)
1459 definition = false;
1461 h = *sym_hash;
1462 while (h->root.type == bfd_link_hash_indirect
1463 || h->root.type == bfd_link_hash_warning)
1464 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1466 /* Remember the old alignment if this is a common symbol, so
1467 that we don't reduce the alignment later on. We can't
1468 check later, because _bfd_generic_link_add_one_symbol
1469 will set a default for the alignment which we want to
1470 override. */
1471 if (h->root.type == bfd_link_hash_common)
1472 old_alignment = h->root.u.c.p->alignment_power;
1474 if (elf_tdata (abfd)->verdef != NULL
1475 && ! override
1476 && vernum > 1
1477 && definition)
1478 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1481 if (! (_bfd_generic_link_add_one_symbol
1482 (info, abfd, name, flags, sec, value, (const char *) NULL,
1483 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1484 goto error_return;
1486 h = *sym_hash;
1487 while (h->root.type == bfd_link_hash_indirect
1488 || h->root.type == bfd_link_hash_warning)
1489 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1490 *sym_hash = h;
1492 new_weakdef = false;
1493 if (dynamic
1494 && definition
1495 && (flags & BSF_WEAK) != 0
1496 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1497 && info->hash->creator->flavour == bfd_target_elf_flavour
1498 && h->weakdef == NULL)
1500 /* Keep a list of all weak defined non function symbols from
1501 a dynamic object, using the weakdef field. Later in this
1502 function we will set the weakdef field to the correct
1503 value. We only put non-function symbols from dynamic
1504 objects on this list, because that happens to be the only
1505 time we need to know the normal symbol corresponding to a
1506 weak symbol, and the information is time consuming to
1507 figure out. If the weakdef field is not already NULL,
1508 then this symbol was already defined by some previous
1509 dynamic object, and we will be using that previous
1510 definition anyhow. */
1512 h->weakdef = weaks;
1513 weaks = h;
1514 new_weakdef = true;
1517 /* Set the alignment of a common symbol. */
1518 if (sym.st_shndx == SHN_COMMON
1519 && h->root.type == bfd_link_hash_common)
1521 unsigned int align;
1523 align = bfd_log2 (sym.st_value);
1524 if (align > old_alignment)
1525 h->root.u.c.p->alignment_power = align;
1528 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1530 int old_flags;
1531 boolean dynsym;
1532 int new_flag;
1534 /* Remember the symbol size and type. */
1535 if (sym.st_size != 0
1536 && (definition || h->size == 0))
1538 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1539 (*_bfd_error_handler)
1540 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1541 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1542 bfd_get_filename (abfd));
1544 h->size = sym.st_size;
1547 /* If this is a common symbol, then we always want H->SIZE
1548 to be the size of the common symbol. The code just above
1549 won't fix the size if a common symbol becomes larger. We
1550 don't warn about a size change here, because that is
1551 covered by --warn-common. */
1552 if (h->root.type == bfd_link_hash_common)
1553 h->size = h->root.u.c.size;
1555 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1556 && (definition || h->type == STT_NOTYPE))
1558 if (h->type != STT_NOTYPE
1559 && h->type != ELF_ST_TYPE (sym.st_info)
1560 && ! type_change_ok)
1561 (*_bfd_error_handler)
1562 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1563 name, h->type, ELF_ST_TYPE (sym.st_info),
1564 bfd_get_filename (abfd));
1566 h->type = ELF_ST_TYPE (sym.st_info);
1569 /* If st_other has a processor-specific meaning, specific code
1570 might be needed here. */
1571 if (sym.st_other != 0)
1573 /* Combine visibilities, using the most constraining one. */
1574 unsigned char hvis = ELF_ST_VISIBILITY (h->other);
1575 unsigned char symvis = ELF_ST_VISIBILITY (sym.st_other);
1577 if (symvis && (hvis > symvis || hvis == 0))
1578 h->other = sym.st_other;
1580 /* If neither has visibility, use the st_other of the
1581 definition. This is an arbitrary choice, since the
1582 other bits have no general meaning. */
1583 if (!symvis && !hvis
1584 && (definition || h->other == 0))
1585 h->other = sym.st_other;
1588 /* Set a flag in the hash table entry indicating the type of
1589 reference or definition we just found. Keep a count of
1590 the number of dynamic symbols we find. A dynamic symbol
1591 is one which is referenced or defined by both a regular
1592 object and a shared object. */
1593 old_flags = h->elf_link_hash_flags;
1594 dynsym = false;
1595 if (! dynamic)
1597 if (! definition)
1599 new_flag = ELF_LINK_HASH_REF_REGULAR;
1600 if (bind != STB_WEAK)
1601 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1603 else
1604 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1605 if (info->shared
1606 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1607 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1608 dynsym = true;
1610 else
1612 if (! definition)
1613 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1614 else
1615 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1616 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1617 | ELF_LINK_HASH_REF_REGULAR)) != 0
1618 || (h->weakdef != NULL
1619 && ! new_weakdef
1620 && h->weakdef->dynindx != -1))
1621 dynsym = true;
1624 h->elf_link_hash_flags |= new_flag;
1626 /* If this symbol has a version, and it is the default
1627 version, we create an indirect symbol from the default
1628 name to the fully decorated name. This will cause
1629 external references which do not specify a version to be
1630 bound to this version of the symbol. */
1631 if (definition)
1633 char *p;
1635 p = strchr (name, ELF_VER_CHR);
1636 if (p != NULL && p[1] == ELF_VER_CHR)
1638 char *shortname;
1639 struct elf_link_hash_entry *hi;
1640 boolean override;
1642 shortname = bfd_hash_allocate (&info->hash->table,
1643 p - name + 1);
1644 if (shortname == NULL)
1645 goto error_return;
1646 strncpy (shortname, name, p - name);
1647 shortname[p - name] = '\0';
1649 /* We are going to create a new symbol. Merge it
1650 with any existing symbol with this name. For the
1651 purposes of the merge, act as though we were
1652 defining the symbol we just defined, although we
1653 actually going to define an indirect symbol. */
1654 type_change_ok = false;
1655 size_change_ok = false;
1656 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1657 &value, &hi, &override,
1658 &type_change_ok, &size_change_ok))
1659 goto error_return;
1661 if (! override)
1663 if (! (_bfd_generic_link_add_one_symbol
1664 (info, abfd, shortname, BSF_INDIRECT,
1665 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1666 collect, (struct bfd_link_hash_entry **) &hi)))
1667 goto error_return;
1669 else
1671 /* In this case the symbol named SHORTNAME is
1672 overriding the indirect symbol we want to
1673 add. We were planning on making SHORTNAME an
1674 indirect symbol referring to NAME. SHORTNAME
1675 is the name without a version. NAME is the
1676 fully versioned name, and it is the default
1677 version.
1679 Overriding means that we already saw a
1680 definition for the symbol SHORTNAME in a
1681 regular object, and it is overriding the
1682 symbol defined in the dynamic object.
1684 When this happens, we actually want to change
1685 NAME, the symbol we just added, to refer to
1686 SHORTNAME. This will cause references to
1687 NAME in the shared object to become
1688 references to SHORTNAME in the regular
1689 object. This is what we expect when we
1690 override a function in a shared object: that
1691 the references in the shared object will be
1692 mapped to the definition in the regular
1693 object. */
1695 while (hi->root.type == bfd_link_hash_indirect
1696 || hi->root.type == bfd_link_hash_warning)
1697 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1699 h->root.type = bfd_link_hash_indirect;
1700 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1701 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1703 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1704 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1705 if (hi->elf_link_hash_flags
1706 & (ELF_LINK_HASH_REF_REGULAR
1707 | ELF_LINK_HASH_DEF_REGULAR))
1709 if (! _bfd_elf_link_record_dynamic_symbol (info,
1710 hi))
1711 goto error_return;
1715 /* Now set HI to H, so that the following code
1716 will set the other fields correctly. */
1717 hi = h;
1720 /* If there is a duplicate definition somewhere,
1721 then HI may not point to an indirect symbol. We
1722 will have reported an error to the user in that
1723 case. */
1725 if (hi->root.type == bfd_link_hash_indirect)
1727 struct elf_link_hash_entry *ht;
1729 /* If the symbol became indirect, then we assume
1730 that we have not seen a definition before. */
1731 BFD_ASSERT ((hi->elf_link_hash_flags
1732 & (ELF_LINK_HASH_DEF_DYNAMIC
1733 | ELF_LINK_HASH_DEF_REGULAR))
1734 == 0);
1736 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1738 /* Copy down any references that we may have
1739 already seen to the symbol which just became
1740 indirect. */
1741 ht->elf_link_hash_flags |=
1742 (hi->elf_link_hash_flags
1743 & (ELF_LINK_HASH_REF_DYNAMIC
1744 | ELF_LINK_HASH_REF_REGULAR
1745 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
1746 | ELF_LINK_NON_GOT_REF));
1748 /* Copy over the global and procedure linkage table
1749 offset entries. These may have been already set
1750 up by a check_relocs routine. */
1751 if (ht->got.offset == (bfd_vma) -1)
1753 ht->got.offset = hi->got.offset;
1754 hi->got.offset = (bfd_vma) -1;
1756 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1758 if (ht->plt.offset == (bfd_vma) -1)
1760 ht->plt.offset = hi->plt.offset;
1761 hi->plt.offset = (bfd_vma) -1;
1763 BFD_ASSERT (hi->plt.offset == (bfd_vma) -1);
1765 if (ht->dynindx == -1)
1767 ht->dynindx = hi->dynindx;
1768 ht->dynstr_index = hi->dynstr_index;
1769 hi->dynindx = -1;
1770 hi->dynstr_index = 0;
1772 BFD_ASSERT (hi->dynindx == -1);
1774 /* FIXME: There may be other information to copy
1775 over for particular targets. */
1777 /* See if the new flags lead us to realize that
1778 the symbol must be dynamic. */
1779 if (! dynsym)
1781 if (! dynamic)
1783 if (info->shared
1784 || ((hi->elf_link_hash_flags
1785 & ELF_LINK_HASH_REF_DYNAMIC)
1786 != 0))
1787 dynsym = true;
1789 else
1791 if ((hi->elf_link_hash_flags
1792 & ELF_LINK_HASH_REF_REGULAR) != 0)
1793 dynsym = true;
1798 /* We also need to define an indirection from the
1799 nondefault version of the symbol. */
1801 shortname = bfd_hash_allocate (&info->hash->table,
1802 strlen (name));
1803 if (shortname == NULL)
1804 goto error_return;
1805 strncpy (shortname, name, p - name);
1806 strcpy (shortname + (p - name), p + 1);
1808 /* Once again, merge with any existing symbol. */
1809 type_change_ok = false;
1810 size_change_ok = false;
1811 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1812 &value, &hi, &override,
1813 &type_change_ok, &size_change_ok))
1814 goto error_return;
1816 if (override)
1818 /* Here SHORTNAME is a versioned name, so we
1819 don't expect to see the type of override we
1820 do in the case above. */
1821 (*_bfd_error_handler)
1822 (_("%s: warning: unexpected redefinition of `%s'"),
1823 bfd_get_filename (abfd), shortname);
1825 else
1827 if (! (_bfd_generic_link_add_one_symbol
1828 (info, abfd, shortname, BSF_INDIRECT,
1829 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1830 collect, (struct bfd_link_hash_entry **) &hi)))
1831 goto error_return;
1833 /* If there is a duplicate definition somewhere,
1834 then HI may not point to an indirect symbol.
1835 We will have reported an error to the user in
1836 that case. */
1838 if (hi->root.type == bfd_link_hash_indirect)
1840 /* If the symbol became indirect, then we
1841 assume that we have not seen a definition
1842 before. */
1843 BFD_ASSERT ((hi->elf_link_hash_flags
1844 & (ELF_LINK_HASH_DEF_DYNAMIC
1845 | ELF_LINK_HASH_DEF_REGULAR))
1846 == 0);
1848 /* Copy down any references that we may have
1849 already seen to the symbol which just
1850 became indirect. */
1851 h->elf_link_hash_flags |=
1852 (hi->elf_link_hash_flags
1853 & (ELF_LINK_HASH_REF_DYNAMIC
1854 | ELF_LINK_HASH_REF_REGULAR
1855 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
1856 | ELF_LINK_NON_GOT_REF));
1858 /* Copy over the global and procedure linkage
1859 table offset entries. These may have been
1860 already set up by a check_relocs routine. */
1861 if (h->got.offset == (bfd_vma) -1)
1863 h->got.offset = hi->got.offset;
1864 hi->got.offset = (bfd_vma) -1;
1866 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1868 if (h->plt.offset == (bfd_vma) -1)
1870 h->plt.offset = hi->plt.offset;
1871 hi->plt.offset = (bfd_vma) -1;
1873 BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
1875 if (h->dynindx == -1)
1877 h->dynindx = hi->dynindx;
1878 h->dynstr_index = hi->dynstr_index;
1879 hi->dynindx = -1;
1880 hi->dynstr_index = 0;
1882 BFD_ASSERT (hi->dynindx == -1);
1884 /* FIXME: There may be other information to
1885 copy over for particular targets. */
1887 /* See if the new flags lead us to realize
1888 that the symbol must be dynamic. */
1889 if (! dynsym)
1891 if (! dynamic)
1893 if (info->shared
1894 || ((hi->elf_link_hash_flags
1895 & ELF_LINK_HASH_REF_DYNAMIC)
1896 != 0))
1897 dynsym = true;
1899 else
1901 if ((hi->elf_link_hash_flags
1902 & ELF_LINK_HASH_REF_REGULAR) != 0)
1903 dynsym = true;
1911 if (dynsym && h->dynindx == -1)
1913 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1914 goto error_return;
1915 if (h->weakdef != NULL
1916 && ! new_weakdef
1917 && h->weakdef->dynindx == -1)
1919 if (! _bfd_elf_link_record_dynamic_symbol (info,
1920 h->weakdef))
1921 goto error_return;
1927 /* Now set the weakdefs field correctly for all the weak defined
1928 symbols we found. The only way to do this is to search all the
1929 symbols. Since we only need the information for non functions in
1930 dynamic objects, that's the only time we actually put anything on
1931 the list WEAKS. We need this information so that if a regular
1932 object refers to a symbol defined weakly in a dynamic object, the
1933 real symbol in the dynamic object is also put in the dynamic
1934 symbols; we also must arrange for both symbols to point to the
1935 same memory location. We could handle the general case of symbol
1936 aliasing, but a general symbol alias can only be generated in
1937 assembler code, handling it correctly would be very time
1938 consuming, and other ELF linkers don't handle general aliasing
1939 either. */
1940 while (weaks != NULL)
1942 struct elf_link_hash_entry *hlook;
1943 asection *slook;
1944 bfd_vma vlook;
1945 struct elf_link_hash_entry **hpp;
1946 struct elf_link_hash_entry **hppend;
1948 hlook = weaks;
1949 weaks = hlook->weakdef;
1950 hlook->weakdef = NULL;
1952 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
1953 || hlook->root.type == bfd_link_hash_defweak
1954 || hlook->root.type == bfd_link_hash_common
1955 || hlook->root.type == bfd_link_hash_indirect);
1956 slook = hlook->root.u.def.section;
1957 vlook = hlook->root.u.def.value;
1959 hpp = elf_sym_hashes (abfd);
1960 hppend = hpp + extsymcount;
1961 for (; hpp < hppend; hpp++)
1963 struct elf_link_hash_entry *h;
1965 h = *hpp;
1966 if (h != NULL && h != hlook
1967 && h->root.type == bfd_link_hash_defined
1968 && h->root.u.def.section == slook
1969 && h->root.u.def.value == vlook)
1971 hlook->weakdef = h;
1973 /* If the weak definition is in the list of dynamic
1974 symbols, make sure the real definition is put there
1975 as well. */
1976 if (hlook->dynindx != -1
1977 && h->dynindx == -1)
1979 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1980 goto error_return;
1983 /* If the real definition is in the list of dynamic
1984 symbols, make sure the weak definition is put there
1985 as well. If we don't do this, then the dynamic
1986 loader might not merge the entries for the real
1987 definition and the weak definition. */
1988 if (h->dynindx != -1
1989 && hlook->dynindx == -1)
1991 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
1992 goto error_return;
1995 break;
2000 if (buf != NULL)
2002 free (buf);
2003 buf = NULL;
2006 if (extversym != NULL)
2008 free (extversym);
2009 extversym = NULL;
2012 /* If this object is the same format as the output object, and it is
2013 not a shared library, then let the backend look through the
2014 relocs.
2016 This is required to build global offset table entries and to
2017 arrange for dynamic relocs. It is not required for the
2018 particular common case of linking non PIC code, even when linking
2019 against shared libraries, but unfortunately there is no way of
2020 knowing whether an object file has been compiled PIC or not.
2021 Looking through the relocs is not particularly time consuming.
2022 The problem is that we must either (1) keep the relocs in memory,
2023 which causes the linker to require additional runtime memory or
2024 (2) read the relocs twice from the input file, which wastes time.
2025 This would be a good case for using mmap.
2027 I have no idea how to handle linking PIC code into a file of a
2028 different format. It probably can't be done. */
2029 check_relocs = get_elf_backend_data (abfd)->check_relocs;
2030 if (! dynamic
2031 && abfd->xvec == info->hash->creator
2032 && check_relocs != NULL)
2034 asection *o;
2036 for (o = abfd->sections; o != NULL; o = o->next)
2038 Elf_Internal_Rela *internal_relocs;
2039 boolean ok;
2041 if ((o->flags & SEC_RELOC) == 0
2042 || o->reloc_count == 0
2043 || ((info->strip == strip_all || info->strip == strip_debugger)
2044 && (o->flags & SEC_DEBUGGING) != 0)
2045 || bfd_is_abs_section (o->output_section))
2046 continue;
2048 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
2049 (abfd, o, (PTR) NULL,
2050 (Elf_Internal_Rela *) NULL,
2051 info->keep_memory));
2052 if (internal_relocs == NULL)
2053 goto error_return;
2055 ok = (*check_relocs) (abfd, info, o, internal_relocs);
2057 if (! info->keep_memory)
2058 free (internal_relocs);
2060 if (! ok)
2061 goto error_return;
2065 /* If this is a non-traditional, non-relocateable link, try to
2066 optimize the handling of the .stab/.stabstr sections. */
2067 if (! dynamic
2068 && ! info->relocateable
2069 && ! info->traditional_format
2070 && info->hash->creator->flavour == bfd_target_elf_flavour
2071 && (info->strip != strip_all && info->strip != strip_debugger))
2073 asection *stab, *stabstr;
2075 stab = bfd_get_section_by_name (abfd, ".stab");
2076 if (stab != NULL)
2078 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
2080 if (stabstr != NULL)
2082 struct bfd_elf_section_data *secdata;
2084 secdata = elf_section_data (stab);
2085 if (! _bfd_link_section_stabs (abfd,
2086 &elf_hash_table (info)->stab_info,
2087 stab, stabstr,
2088 &secdata->stab_info))
2089 goto error_return;
2094 return true;
2096 error_return:
2097 if (buf != NULL)
2098 free (buf);
2099 if (dynbuf != NULL)
2100 free (dynbuf);
2101 if (dynver != NULL)
2102 free (dynver);
2103 if (extversym != NULL)
2104 free (extversym);
2105 return false;
2108 /* Create some sections which will be filled in with dynamic linking
2109 information. ABFD is an input file which requires dynamic sections
2110 to be created. The dynamic sections take up virtual memory space
2111 when the final executable is run, so we need to create them before
2112 addresses are assigned to the output sections. We work out the
2113 actual contents and size of these sections later. */
2115 boolean
2116 elf_link_create_dynamic_sections (abfd, info)
2117 bfd *abfd;
2118 struct bfd_link_info *info;
2120 flagword flags;
2121 register asection *s;
2122 struct elf_link_hash_entry *h;
2123 struct elf_backend_data *bed;
2125 if (elf_hash_table (info)->dynamic_sections_created)
2126 return true;
2128 /* Make sure that all dynamic sections use the same input BFD. */
2129 if (elf_hash_table (info)->dynobj == NULL)
2130 elf_hash_table (info)->dynobj = abfd;
2131 else
2132 abfd = elf_hash_table (info)->dynobj;
2134 /* Note that we set the SEC_IN_MEMORY flag for all of these
2135 sections. */
2136 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
2137 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2139 /* A dynamically linked executable has a .interp section, but a
2140 shared library does not. */
2141 if (! info->shared)
2143 s = bfd_make_section (abfd, ".interp");
2144 if (s == NULL
2145 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2146 return false;
2149 /* Create sections to hold version informations. These are removed
2150 if they are not needed. */
2151 s = bfd_make_section (abfd, ".gnu.version_d");
2152 if (s == NULL
2153 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2154 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2155 return false;
2157 s = bfd_make_section (abfd, ".gnu.version");
2158 if (s == NULL
2159 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2160 || ! bfd_set_section_alignment (abfd, s, 1))
2161 return false;
2163 s = bfd_make_section (abfd, ".gnu.version_r");
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;
2169 s = bfd_make_section (abfd, ".dynsym");
2170 if (s == NULL
2171 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2172 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2173 return false;
2175 s = bfd_make_section (abfd, ".dynstr");
2176 if (s == NULL
2177 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2178 return false;
2180 /* Create a strtab to hold the dynamic symbol names. */
2181 if (elf_hash_table (info)->dynstr == NULL)
2183 elf_hash_table (info)->dynstr = elf_stringtab_init ();
2184 if (elf_hash_table (info)->dynstr == NULL)
2185 return false;
2188 s = bfd_make_section (abfd, ".dynamic");
2189 if (s == NULL
2190 || ! bfd_set_section_flags (abfd, s, flags)
2191 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2192 return false;
2194 /* The special symbol _DYNAMIC is always set to the start of the
2195 .dynamic section. This call occurs before we have processed the
2196 symbols for any dynamic object, so we don't have to worry about
2197 overriding a dynamic definition. We could set _DYNAMIC in a
2198 linker script, but we only want to define it if we are, in fact,
2199 creating a .dynamic section. We don't want to define it if there
2200 is no .dynamic section, since on some ELF platforms the start up
2201 code examines it to decide how to initialize the process. */
2202 h = NULL;
2203 if (! (_bfd_generic_link_add_one_symbol
2204 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
2205 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
2206 (struct bfd_link_hash_entry **) &h)))
2207 return false;
2208 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2209 h->type = STT_OBJECT;
2211 if (info->shared
2212 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
2213 return false;
2215 bed = get_elf_backend_data (abfd);
2217 s = bfd_make_section (abfd, ".hash");
2218 if (s == NULL
2219 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2220 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2221 return false;
2222 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
2224 /* Let the backend create the rest of the sections. This lets the
2225 backend set the right flags. The backend will normally create
2226 the .got and .plt sections. */
2227 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
2228 return false;
2230 elf_hash_table (info)->dynamic_sections_created = true;
2232 return true;
2235 /* Add an entry to the .dynamic table. */
2237 boolean
2238 elf_add_dynamic_entry (info, tag, val)
2239 struct bfd_link_info *info;
2240 bfd_vma tag;
2241 bfd_vma val;
2243 Elf_Internal_Dyn dyn;
2244 bfd *dynobj;
2245 asection *s;
2246 size_t newsize;
2247 bfd_byte *newcontents;
2249 dynobj = elf_hash_table (info)->dynobj;
2251 s = bfd_get_section_by_name (dynobj, ".dynamic");
2252 BFD_ASSERT (s != NULL);
2254 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
2255 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
2256 if (newcontents == NULL)
2257 return false;
2259 dyn.d_tag = tag;
2260 dyn.d_un.d_val = val;
2261 elf_swap_dyn_out (dynobj, &dyn,
2262 (Elf_External_Dyn *) (newcontents + s->_raw_size));
2264 s->_raw_size = newsize;
2265 s->contents = newcontents;
2267 return true;
2270 /* Record a new local dynamic symbol. */
2272 boolean
2273 elf_link_record_local_dynamic_symbol (info, input_bfd, input_indx)
2274 struct bfd_link_info *info;
2275 bfd *input_bfd;
2276 long input_indx;
2278 struct elf_link_local_dynamic_entry *entry;
2279 struct elf_link_hash_table *eht;
2280 struct bfd_strtab_hash *dynstr;
2281 Elf_External_Sym esym;
2282 unsigned long dynstr_index;
2283 char *name;
2285 /* See if the entry exists already. */
2286 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
2287 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
2288 return true;
2290 entry = (struct elf_link_local_dynamic_entry *)
2291 bfd_alloc (input_bfd, sizeof (*entry));
2292 if (entry == NULL)
2293 return false;
2295 /* Go find the symbol, so that we can find it's name. */
2296 if (bfd_seek (input_bfd,
2297 (elf_tdata (input_bfd)->symtab_hdr.sh_offset
2298 + input_indx * sizeof (Elf_External_Sym)),
2299 SEEK_SET) != 0
2300 || (bfd_read (&esym, sizeof (Elf_External_Sym), 1, input_bfd)
2301 != sizeof (Elf_External_Sym)))
2302 return false;
2303 elf_swap_symbol_in (input_bfd, &esym, &entry->isym);
2305 name = (bfd_elf_string_from_elf_section
2306 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
2307 entry->isym.st_name));
2309 dynstr = elf_hash_table (info)->dynstr;
2310 if (dynstr == NULL)
2312 /* Create a strtab to hold the dynamic symbol names. */
2313 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_stringtab_init ();
2314 if (dynstr == NULL)
2315 return false;
2318 dynstr_index = _bfd_stringtab_add (dynstr, name, true, false);
2319 if (dynstr_index == (unsigned long) -1)
2320 return false;
2321 entry->isym.st_name = dynstr_index;
2323 eht = elf_hash_table (info);
2325 entry->next = eht->dynlocal;
2326 eht->dynlocal = entry;
2327 entry->input_bfd = input_bfd;
2328 entry->input_indx = input_indx;
2329 eht->dynsymcount++;
2331 /* Whatever binding the symbol had before, it's now local. */
2332 entry->isym.st_info
2333 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
2335 /* The dynindx will be set at the end of size_dynamic_sections. */
2337 return true;
2341 /* Read and swap the relocs from the section indicated by SHDR. This
2342 may be either a REL or a RELA section. The relocations are
2343 translated into RELA relocations and stored in INTERNAL_RELOCS,
2344 which should have already been allocated to contain enough space.
2345 The EXTERNAL_RELOCS are a buffer where the external form of the
2346 relocations should be stored.
2348 Returns false if something goes wrong. */
2350 static boolean
2351 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2352 internal_relocs)
2353 bfd *abfd;
2354 Elf_Internal_Shdr *shdr;
2355 PTR external_relocs;
2356 Elf_Internal_Rela *internal_relocs;
2358 struct elf_backend_data *bed;
2360 /* If there aren't any relocations, that's OK. */
2361 if (!shdr)
2362 return true;
2364 /* Position ourselves at the start of the section. */
2365 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2366 return false;
2368 /* Read the relocations. */
2369 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2370 != shdr->sh_size)
2371 return false;
2373 bed = get_elf_backend_data (abfd);
2375 /* Convert the external relocations to the internal format. */
2376 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2378 Elf_External_Rel *erel;
2379 Elf_External_Rel *erelend;
2380 Elf_Internal_Rela *irela;
2381 Elf_Internal_Rel *irel;
2383 erel = (Elf_External_Rel *) external_relocs;
2384 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2385 irela = internal_relocs;
2386 irel = bfd_alloc (abfd, (bed->s->int_rels_per_ext_rel
2387 * sizeof (Elf_Internal_Rel)));
2388 for (; erel < erelend; erel++, irela += bed->s->int_rels_per_ext_rel)
2390 unsigned char i;
2392 if (bed->s->swap_reloc_in)
2393 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, irel);
2394 else
2395 elf_swap_reloc_in (abfd, erel, irel);
2397 for (i = 0; i < bed->s->int_rels_per_ext_rel; ++i)
2399 irela[i].r_offset = irel[i].r_offset;
2400 irela[i].r_info = irel[i].r_info;
2401 irela[i].r_addend = 0;
2405 else
2407 Elf_External_Rela *erela;
2408 Elf_External_Rela *erelaend;
2409 Elf_Internal_Rela *irela;
2411 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2413 erela = (Elf_External_Rela *) external_relocs;
2414 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2415 irela = internal_relocs;
2416 for (; erela < erelaend; erela++, irela += bed->s->int_rels_per_ext_rel)
2418 if (bed->s->swap_reloca_in)
2419 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, irela);
2420 else
2421 elf_swap_reloca_in (abfd, erela, irela);
2425 return true;
2428 /* Read and swap the relocs for a section O. They may have been
2429 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2430 not NULL, they are used as buffers to read into. They are known to
2431 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
2432 the return value is allocated using either malloc or bfd_alloc,
2433 according to the KEEP_MEMORY argument. If O has two relocation
2434 sections (both REL and RELA relocations), then the REL_HDR
2435 relocations will appear first in INTERNAL_RELOCS, followed by the
2436 REL_HDR2 relocations. */
2438 Elf_Internal_Rela *
2439 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2440 keep_memory)
2441 bfd *abfd;
2442 asection *o;
2443 PTR external_relocs;
2444 Elf_Internal_Rela *internal_relocs;
2445 boolean keep_memory;
2447 Elf_Internal_Shdr *rel_hdr;
2448 PTR alloc1 = NULL;
2449 Elf_Internal_Rela *alloc2 = NULL;
2450 struct elf_backend_data *bed = get_elf_backend_data (abfd);
2452 if (elf_section_data (o)->relocs != NULL)
2453 return elf_section_data (o)->relocs;
2455 if (o->reloc_count == 0)
2456 return NULL;
2458 rel_hdr = &elf_section_data (o)->rel_hdr;
2460 if (internal_relocs == NULL)
2462 size_t size;
2464 size = (o->reloc_count * bed->s->int_rels_per_ext_rel
2465 * sizeof (Elf_Internal_Rela));
2466 if (keep_memory)
2467 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2468 else
2469 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2470 if (internal_relocs == NULL)
2471 goto error_return;
2474 if (external_relocs == NULL)
2476 size_t size = (size_t) rel_hdr->sh_size;
2478 if (elf_section_data (o)->rel_hdr2)
2479 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2480 alloc1 = (PTR) bfd_malloc (size);
2481 if (alloc1 == NULL)
2482 goto error_return;
2483 external_relocs = alloc1;
2486 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2487 external_relocs,
2488 internal_relocs))
2489 goto error_return;
2490 if (!elf_link_read_relocs_from_section
2491 (abfd,
2492 elf_section_data (o)->rel_hdr2,
2493 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
2494 internal_relocs + (rel_hdr->sh_size / rel_hdr->sh_entsize
2495 * bed->s->int_rels_per_ext_rel)))
2496 goto error_return;
2498 /* Cache the results for next time, if we can. */
2499 if (keep_memory)
2500 elf_section_data (o)->relocs = internal_relocs;
2502 if (alloc1 != NULL)
2503 free (alloc1);
2505 /* Don't free alloc2, since if it was allocated we are passing it
2506 back (under the name of internal_relocs). */
2508 return internal_relocs;
2510 error_return:
2511 if (alloc1 != NULL)
2512 free (alloc1);
2513 if (alloc2 != NULL)
2514 free (alloc2);
2515 return NULL;
2519 /* Record an assignment to a symbol made by a linker script. We need
2520 this in case some dynamic object refers to this symbol. */
2522 /*ARGSUSED*/
2523 boolean
2524 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2525 bfd *output_bfd ATTRIBUTE_UNUSED;
2526 struct bfd_link_info *info;
2527 const char *name;
2528 boolean provide;
2530 struct elf_link_hash_entry *h;
2532 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2533 return true;
2535 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2536 if (h == NULL)
2537 return false;
2539 if (h->root.type == bfd_link_hash_new)
2540 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2542 /* If this symbol is being provided by the linker script, and it is
2543 currently defined by a dynamic object, but not by a regular
2544 object, then mark it as undefined so that the generic linker will
2545 force the correct value. */
2546 if (provide
2547 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2548 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2549 h->root.type = bfd_link_hash_undefined;
2551 /* If this symbol is not being provided by the linker script, and it is
2552 currently defined by a dynamic object, but not by a regular object,
2553 then clear out any version information because the symbol will not be
2554 associated with the dynamic object any more. */
2555 if (!provide
2556 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2557 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2558 h->verinfo.verdef = NULL;
2560 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2562 /* When possible, keep the original type of the symbol */
2563 if (h->type == STT_NOTYPE)
2564 h->type = STT_OBJECT;
2566 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2567 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2568 || info->shared)
2569 && h->dynindx == -1)
2571 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2572 return false;
2574 /* If this is a weak defined symbol, and we know a corresponding
2575 real symbol from the same dynamic object, make sure the real
2576 symbol is also made into a dynamic symbol. */
2577 if (h->weakdef != NULL
2578 && h->weakdef->dynindx == -1)
2580 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2581 return false;
2585 return true;
2588 /* This structure is used to pass information to
2589 elf_link_assign_sym_version. */
2591 struct elf_assign_sym_version_info
2593 /* Output BFD. */
2594 bfd *output_bfd;
2595 /* General link information. */
2596 struct bfd_link_info *info;
2597 /* Version tree. */
2598 struct bfd_elf_version_tree *verdefs;
2599 /* Whether we are exporting all dynamic symbols. */
2600 boolean export_dynamic;
2601 /* Whether we had a failure. */
2602 boolean failed;
2605 /* This structure is used to pass information to
2606 elf_link_find_version_dependencies. */
2608 struct elf_find_verdep_info
2610 /* Output BFD. */
2611 bfd *output_bfd;
2612 /* General link information. */
2613 struct bfd_link_info *info;
2614 /* The number of dependencies. */
2615 unsigned int vers;
2616 /* Whether we had a failure. */
2617 boolean failed;
2620 /* Array used to determine the number of hash table buckets to use
2621 based on the number of symbols there are. If there are fewer than
2622 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2623 fewer than 37 we use 17 buckets, and so forth. We never use more
2624 than 32771 buckets. */
2626 static const size_t elf_buckets[] =
2628 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2629 16411, 32771, 0
2632 /* Compute bucket count for hashing table. We do not use a static set
2633 of possible tables sizes anymore. Instead we determine for all
2634 possible reasonable sizes of the table the outcome (i.e., the
2635 number of collisions etc) and choose the best solution. The
2636 weighting functions are not too simple to allow the table to grow
2637 without bounds. Instead one of the weighting factors is the size.
2638 Therefore the result is always a good payoff between few collisions
2639 (= short chain lengths) and table size. */
2640 static size_t
2641 compute_bucket_count (info)
2642 struct bfd_link_info *info;
2644 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2645 size_t best_size = 0;
2646 unsigned long int *hashcodes;
2647 unsigned long int *hashcodesp;
2648 unsigned long int i;
2650 /* Compute the hash values for all exported symbols. At the same
2651 time store the values in an array so that we could use them for
2652 optimizations. */
2653 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2654 * sizeof (unsigned long int));
2655 if (hashcodes == NULL)
2656 return 0;
2657 hashcodesp = hashcodes;
2659 /* Put all hash values in HASHCODES. */
2660 elf_link_hash_traverse (elf_hash_table (info),
2661 elf_collect_hash_codes, &hashcodesp);
2663 /* We have a problem here. The following code to optimize the table
2664 size requires an integer type with more the 32 bits. If
2665 BFD_HOST_U_64_BIT is set we know about such a type. */
2666 #ifdef BFD_HOST_U_64_BIT
2667 if (info->optimize == true)
2669 unsigned long int nsyms = hashcodesp - hashcodes;
2670 size_t minsize;
2671 size_t maxsize;
2672 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2673 unsigned long int *counts ;
2675 /* Possible optimization parameters: if we have NSYMS symbols we say
2676 that the hashing table must at least have NSYMS/4 and at most
2677 2*NSYMS buckets. */
2678 minsize = nsyms / 4;
2679 if (minsize == 0)
2680 minsize = 1;
2681 best_size = maxsize = nsyms * 2;
2683 /* Create array where we count the collisions in. We must use bfd_malloc
2684 since the size could be large. */
2685 counts = (unsigned long int *) bfd_malloc (maxsize
2686 * sizeof (unsigned long int));
2687 if (counts == NULL)
2689 free (hashcodes);
2690 return 0;
2693 /* Compute the "optimal" size for the hash table. The criteria is a
2694 minimal chain length. The minor criteria is (of course) the size
2695 of the table. */
2696 for (i = minsize; i < maxsize; ++i)
2698 /* Walk through the array of hashcodes and count the collisions. */
2699 BFD_HOST_U_64_BIT max;
2700 unsigned long int j;
2701 unsigned long int fact;
2703 memset (counts, '\0', i * sizeof (unsigned long int));
2705 /* Determine how often each hash bucket is used. */
2706 for (j = 0; j < nsyms; ++j)
2707 ++counts[hashcodes[j] % i];
2709 /* For the weight function we need some information about the
2710 pagesize on the target. This is information need not be 100%
2711 accurate. Since this information is not available (so far) we
2712 define it here to a reasonable default value. If it is crucial
2713 to have a better value some day simply define this value. */
2714 # ifndef BFD_TARGET_PAGESIZE
2715 # define BFD_TARGET_PAGESIZE (4096)
2716 # endif
2718 /* We in any case need 2 + NSYMS entries for the size values and
2719 the chains. */
2720 max = (2 + nsyms) * (ARCH_SIZE / 8);
2722 # if 1
2723 /* Variant 1: optimize for short chains. We add the squares
2724 of all the chain lengths (which favous many small chain
2725 over a few long chains). */
2726 for (j = 0; j < i; ++j)
2727 max += counts[j] * counts[j];
2729 /* This adds penalties for the overall size of the table. */
2730 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2731 max *= fact * fact;
2732 # else
2733 /* Variant 2: Optimize a lot more for small table. Here we
2734 also add squares of the size but we also add penalties for
2735 empty slots (the +1 term). */
2736 for (j = 0; j < i; ++j)
2737 max += (1 + counts[j]) * (1 + counts[j]);
2739 /* The overall size of the table is considered, but not as
2740 strong as in variant 1, where it is squared. */
2741 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2742 max *= fact;
2743 # endif
2745 /* Compare with current best results. */
2746 if (max < best_chlen)
2748 best_chlen = max;
2749 best_size = i;
2753 free (counts);
2755 else
2756 #endif /* defined (BFD_HOST_U_64_BIT) */
2758 /* This is the fallback solution if no 64bit type is available or if we
2759 are not supposed to spend much time on optimizations. We select the
2760 bucket count using a fixed set of numbers. */
2761 for (i = 0; elf_buckets[i] != 0; i++)
2763 best_size = elf_buckets[i];
2764 if (dynsymcount < elf_buckets[i + 1])
2765 break;
2769 /* Free the arrays we needed. */
2770 free (hashcodes);
2772 return best_size;
2775 /* Set up the sizes and contents of the ELF dynamic sections. This is
2776 called by the ELF linker emulation before_allocation routine. We
2777 must set the sizes of the sections before the linker sets the
2778 addresses of the various sections. */
2780 boolean
2781 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2782 export_dynamic, filter_shlib,
2783 auxiliary_filters, info, sinterpptr,
2784 verdefs)
2785 bfd *output_bfd;
2786 const char *soname;
2787 const char *rpath;
2788 boolean export_dynamic;
2789 const char *filter_shlib;
2790 const char * const *auxiliary_filters;
2791 struct bfd_link_info *info;
2792 asection **sinterpptr;
2793 struct bfd_elf_version_tree *verdefs;
2795 bfd_size_type soname_indx;
2796 bfd *dynobj;
2797 struct elf_backend_data *bed;
2798 struct elf_assign_sym_version_info asvinfo;
2800 *sinterpptr = NULL;
2802 soname_indx = (bfd_size_type) -1;
2804 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2805 return true;
2807 /* The backend may have to create some sections regardless of whether
2808 we're dynamic or not. */
2809 bed = get_elf_backend_data (output_bfd);
2810 if (bed->elf_backend_always_size_sections
2811 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2812 return false;
2814 dynobj = elf_hash_table (info)->dynobj;
2816 /* If there were no dynamic objects in the link, there is nothing to
2817 do here. */
2818 if (dynobj == NULL)
2819 return true;
2821 if (elf_hash_table (info)->dynamic_sections_created)
2823 struct elf_info_failed eif;
2824 struct elf_link_hash_entry *h;
2825 bfd_size_type strsize;
2827 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2828 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2830 if (soname != NULL)
2832 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2833 soname, true, true);
2834 if (soname_indx == (bfd_size_type) -1
2835 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2836 return false;
2839 if (info->symbolic)
2841 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2842 return false;
2845 if (rpath != NULL)
2847 bfd_size_type indx;
2849 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2850 true, true);
2851 if (indx == (bfd_size_type) -1
2852 || ! elf_add_dynamic_entry (info, DT_RPATH, indx))
2853 return false;
2856 if (filter_shlib != NULL)
2858 bfd_size_type indx;
2860 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2861 filter_shlib, true, true);
2862 if (indx == (bfd_size_type) -1
2863 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2864 return false;
2867 if (auxiliary_filters != NULL)
2869 const char * const *p;
2871 for (p = auxiliary_filters; *p != NULL; p++)
2873 bfd_size_type indx;
2875 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2876 *p, true, true);
2877 if (indx == (bfd_size_type) -1
2878 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2879 return false;
2883 /* If we are supposed to export all symbols into the dynamic symbol
2884 table (this is not the normal case), then do so. */
2885 if (export_dynamic)
2887 struct elf_info_failed eif;
2889 eif.failed = false;
2890 eif.info = info;
2891 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2892 (PTR) &eif);
2893 if (eif.failed)
2894 return false;
2897 /* Attach all the symbols to their version information. */
2898 asvinfo.output_bfd = output_bfd;
2899 asvinfo.info = info;
2900 asvinfo.verdefs = verdefs;
2901 asvinfo.export_dynamic = export_dynamic;
2902 asvinfo.failed = false;
2904 elf_link_hash_traverse (elf_hash_table (info),
2905 elf_link_assign_sym_version,
2906 (PTR) &asvinfo);
2907 if (asvinfo.failed)
2908 return false;
2910 /* Find all symbols which were defined in a dynamic object and make
2911 the backend pick a reasonable value for them. */
2912 eif.failed = false;
2913 eif.info = info;
2914 elf_link_hash_traverse (elf_hash_table (info),
2915 elf_adjust_dynamic_symbol,
2916 (PTR) &eif);
2917 if (eif.failed)
2918 return false;
2920 /* Add some entries to the .dynamic section. We fill in some of the
2921 values later, in elf_bfd_final_link, but we must add the entries
2922 now so that we know the final size of the .dynamic section. */
2924 /* If there are initialization and/or finalization functions to
2925 call then add the corresponding DT_INIT/DT_FINI entries. */
2926 h = (info->init_function
2927 ? elf_link_hash_lookup (elf_hash_table (info),
2928 info->init_function, false,
2929 false, false)
2930 : NULL);
2931 if (h != NULL
2932 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2933 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2935 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
2936 return false;
2938 h = (info->fini_function
2939 ? elf_link_hash_lookup (elf_hash_table (info),
2940 info->fini_function, false,
2941 false, false)
2942 : NULL);
2943 if (h != NULL
2944 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
2945 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
2947 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
2948 return false;
2951 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
2952 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
2953 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
2954 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
2955 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
2956 || ! elf_add_dynamic_entry (info, DT_SYMENT,
2957 sizeof (Elf_External_Sym)))
2958 return false;
2961 /* The backend must work out the sizes of all the other dynamic
2962 sections. */
2963 if (bed->elf_backend_size_dynamic_sections
2964 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
2965 return false;
2967 if (elf_hash_table (info)->dynamic_sections_created)
2969 size_t dynsymcount;
2970 asection *s;
2971 size_t bucketcount = 0;
2972 Elf_Internal_Sym isym;
2973 size_t hash_entry_size;
2975 /* Set up the version definition section. */
2976 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
2977 BFD_ASSERT (s != NULL);
2979 /* We may have created additional version definitions if we are
2980 just linking a regular application. */
2981 verdefs = asvinfo.verdefs;
2983 if (verdefs == NULL)
2984 _bfd_strip_section_from_output (s);
2985 else
2987 unsigned int cdefs;
2988 bfd_size_type size;
2989 struct bfd_elf_version_tree *t;
2990 bfd_byte *p;
2991 Elf_Internal_Verdef def;
2992 Elf_Internal_Verdaux defaux;
2994 cdefs = 0;
2995 size = 0;
2997 /* Make space for the base version. */
2998 size += sizeof (Elf_External_Verdef);
2999 size += sizeof (Elf_External_Verdaux);
3000 ++cdefs;
3002 for (t = verdefs; t != NULL; t = t->next)
3004 struct bfd_elf_version_deps *n;
3006 size += sizeof (Elf_External_Verdef);
3007 size += sizeof (Elf_External_Verdaux);
3008 ++cdefs;
3010 for (n = t->deps; n != NULL; n = n->next)
3011 size += sizeof (Elf_External_Verdaux);
3014 s->_raw_size = size;
3015 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3016 if (s->contents == NULL && s->_raw_size != 0)
3017 return false;
3019 /* Fill in the version definition section. */
3021 p = s->contents;
3023 def.vd_version = VER_DEF_CURRENT;
3024 def.vd_flags = VER_FLG_BASE;
3025 def.vd_ndx = 1;
3026 def.vd_cnt = 1;
3027 def.vd_aux = sizeof (Elf_External_Verdef);
3028 def.vd_next = (sizeof (Elf_External_Verdef)
3029 + sizeof (Elf_External_Verdaux));
3031 if (soname_indx != (bfd_size_type) -1)
3033 def.vd_hash = bfd_elf_hash (soname);
3034 defaux.vda_name = soname_indx;
3036 else
3038 const char *name;
3039 bfd_size_type indx;
3041 name = output_bfd->filename;
3042 def.vd_hash = bfd_elf_hash (name);
3043 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3044 name, true, false);
3045 if (indx == (bfd_size_type) -1)
3046 return false;
3047 defaux.vda_name = indx;
3049 defaux.vda_next = 0;
3051 _bfd_elf_swap_verdef_out (output_bfd, &def,
3052 (Elf_External_Verdef *)p);
3053 p += sizeof (Elf_External_Verdef);
3054 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3055 (Elf_External_Verdaux *) p);
3056 p += sizeof (Elf_External_Verdaux);
3058 for (t = verdefs; t != NULL; t = t->next)
3060 unsigned int cdeps;
3061 struct bfd_elf_version_deps *n;
3062 struct elf_link_hash_entry *h;
3064 cdeps = 0;
3065 for (n = t->deps; n != NULL; n = n->next)
3066 ++cdeps;
3068 /* Add a symbol representing this version. */
3069 h = NULL;
3070 if (! (_bfd_generic_link_add_one_symbol
3071 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3072 (bfd_vma) 0, (const char *) NULL, false,
3073 get_elf_backend_data (dynobj)->collect,
3074 (struct bfd_link_hash_entry **) &h)))
3075 return false;
3076 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3077 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3078 h->type = STT_OBJECT;
3079 h->verinfo.vertree = t;
3081 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3082 return false;
3084 def.vd_version = VER_DEF_CURRENT;
3085 def.vd_flags = 0;
3086 if (t->globals == NULL && t->locals == NULL && ! t->used)
3087 def.vd_flags |= VER_FLG_WEAK;
3088 def.vd_ndx = t->vernum + 1;
3089 def.vd_cnt = cdeps + 1;
3090 def.vd_hash = bfd_elf_hash (t->name);
3091 def.vd_aux = sizeof (Elf_External_Verdef);
3092 if (t->next != NULL)
3093 def.vd_next = (sizeof (Elf_External_Verdef)
3094 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3095 else
3096 def.vd_next = 0;
3098 _bfd_elf_swap_verdef_out (output_bfd, &def,
3099 (Elf_External_Verdef *) p);
3100 p += sizeof (Elf_External_Verdef);
3102 defaux.vda_name = h->dynstr_index;
3103 if (t->deps == NULL)
3104 defaux.vda_next = 0;
3105 else
3106 defaux.vda_next = sizeof (Elf_External_Verdaux);
3107 t->name_indx = defaux.vda_name;
3109 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3110 (Elf_External_Verdaux *) p);
3111 p += sizeof (Elf_External_Verdaux);
3113 for (n = t->deps; n != NULL; n = n->next)
3115 if (n->version_needed == NULL)
3117 /* This can happen if there was an error in the
3118 version script. */
3119 defaux.vda_name = 0;
3121 else
3122 defaux.vda_name = n->version_needed->name_indx;
3123 if (n->next == NULL)
3124 defaux.vda_next = 0;
3125 else
3126 defaux.vda_next = sizeof (Elf_External_Verdaux);
3128 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3129 (Elf_External_Verdaux *) p);
3130 p += sizeof (Elf_External_Verdaux);
3134 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3135 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3136 return false;
3138 elf_tdata (output_bfd)->cverdefs = cdefs;
3141 /* Work out the size of the version reference section. */
3143 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3144 BFD_ASSERT (s != NULL);
3146 struct elf_find_verdep_info sinfo;
3148 sinfo.output_bfd = output_bfd;
3149 sinfo.info = info;
3150 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3151 if (sinfo.vers == 0)
3152 sinfo.vers = 1;
3153 sinfo.failed = false;
3155 elf_link_hash_traverse (elf_hash_table (info),
3156 elf_link_find_version_dependencies,
3157 (PTR) &sinfo);
3159 if (elf_tdata (output_bfd)->verref == NULL)
3160 _bfd_strip_section_from_output (s);
3161 else
3163 Elf_Internal_Verneed *t;
3164 unsigned int size;
3165 unsigned int crefs;
3166 bfd_byte *p;
3168 /* Build the version definition section. */
3169 size = 0;
3170 crefs = 0;
3171 for (t = elf_tdata (output_bfd)->verref;
3172 t != NULL;
3173 t = t->vn_nextref)
3175 Elf_Internal_Vernaux *a;
3177 size += sizeof (Elf_External_Verneed);
3178 ++crefs;
3179 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3180 size += sizeof (Elf_External_Vernaux);
3183 s->_raw_size = size;
3184 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3185 if (s->contents == NULL)
3186 return false;
3188 p = s->contents;
3189 for (t = elf_tdata (output_bfd)->verref;
3190 t != NULL;
3191 t = t->vn_nextref)
3193 unsigned int caux;
3194 Elf_Internal_Vernaux *a;
3195 bfd_size_type indx;
3197 caux = 0;
3198 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3199 ++caux;
3201 t->vn_version = VER_NEED_CURRENT;
3202 t->vn_cnt = caux;
3203 if (elf_dt_name (t->vn_bfd) != NULL)
3204 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3205 elf_dt_name (t->vn_bfd),
3206 true, false);
3207 else
3208 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3209 t->vn_bfd->filename, true, false);
3210 if (indx == (bfd_size_type) -1)
3211 return false;
3212 t->vn_file = indx;
3213 t->vn_aux = sizeof (Elf_External_Verneed);
3214 if (t->vn_nextref == NULL)
3215 t->vn_next = 0;
3216 else
3217 t->vn_next = (sizeof (Elf_External_Verneed)
3218 + caux * sizeof (Elf_External_Vernaux));
3220 _bfd_elf_swap_verneed_out (output_bfd, t,
3221 (Elf_External_Verneed *) p);
3222 p += sizeof (Elf_External_Verneed);
3224 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3226 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3227 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3228 a->vna_nodename, true, false);
3229 if (indx == (bfd_size_type) -1)
3230 return false;
3231 a->vna_name = indx;
3232 if (a->vna_nextptr == NULL)
3233 a->vna_next = 0;
3234 else
3235 a->vna_next = sizeof (Elf_External_Vernaux);
3237 _bfd_elf_swap_vernaux_out (output_bfd, a,
3238 (Elf_External_Vernaux *) p);
3239 p += sizeof (Elf_External_Vernaux);
3243 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3244 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3245 return false;
3247 elf_tdata (output_bfd)->cverrefs = crefs;
3251 /* Assign dynsym indicies. In a shared library we generate a
3252 section symbol for each output section, which come first.
3253 Next come all of the back-end allocated local dynamic syms,
3254 followed by the rest of the global symbols. */
3256 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3258 /* Work out the size of the symbol version section. */
3259 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3260 BFD_ASSERT (s != NULL);
3261 if (dynsymcount == 0
3262 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3264 _bfd_strip_section_from_output (s);
3265 /* The DYNSYMCOUNT might have changed if we were going to
3266 output a dynamic symbol table entry for S. */
3267 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3269 else
3271 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3272 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3273 if (s->contents == NULL)
3274 return false;
3276 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3277 return false;
3280 /* Set the size of the .dynsym and .hash sections. We counted
3281 the number of dynamic symbols in elf_link_add_object_symbols.
3282 We will build the contents of .dynsym and .hash when we build
3283 the final symbol table, because until then we do not know the
3284 correct value to give the symbols. We built the .dynstr
3285 section as we went along in elf_link_add_object_symbols. */
3286 s = bfd_get_section_by_name (dynobj, ".dynsym");
3287 BFD_ASSERT (s != NULL);
3288 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3289 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3290 if (s->contents == NULL && s->_raw_size != 0)
3291 return false;
3293 /* The first entry in .dynsym is a dummy symbol. */
3294 isym.st_value = 0;
3295 isym.st_size = 0;
3296 isym.st_name = 0;
3297 isym.st_info = 0;
3298 isym.st_other = 0;
3299 isym.st_shndx = 0;
3300 elf_swap_symbol_out (output_bfd, &isym,
3301 (PTR) (Elf_External_Sym *) s->contents);
3303 /* Compute the size of the hashing table. As a side effect this
3304 computes the hash values for all the names we export. */
3305 bucketcount = compute_bucket_count (info);
3307 s = bfd_get_section_by_name (dynobj, ".hash");
3308 BFD_ASSERT (s != NULL);
3309 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3310 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3311 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3312 if (s->contents == NULL)
3313 return false;
3314 memset (s->contents, 0, (size_t) s->_raw_size);
3316 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3317 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3318 s->contents + hash_entry_size);
3320 elf_hash_table (info)->bucketcount = bucketcount;
3322 s = bfd_get_section_by_name (dynobj, ".dynstr");
3323 BFD_ASSERT (s != NULL);
3324 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3326 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3327 return false;
3330 return true;
3333 /* Fix up the flags for a symbol. This handles various cases which
3334 can only be fixed after all the input files are seen. This is
3335 currently called by both adjust_dynamic_symbol and
3336 assign_sym_version, which is unnecessary but perhaps more robust in
3337 the face of future changes. */
3339 static boolean
3340 elf_fix_symbol_flags (h, eif)
3341 struct elf_link_hash_entry *h;
3342 struct elf_info_failed *eif;
3344 /* If this symbol was mentioned in a non-ELF file, try to set
3345 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3346 permit a non-ELF file to correctly refer to a symbol defined in
3347 an ELF dynamic object. */
3348 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3350 if (h->root.type != bfd_link_hash_defined
3351 && h->root.type != bfd_link_hash_defweak)
3352 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3353 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3354 else
3356 if (h->root.u.def.section->owner != NULL
3357 && (bfd_get_flavour (h->root.u.def.section->owner)
3358 == bfd_target_elf_flavour))
3359 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3360 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3361 else
3362 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3365 if (h->dynindx == -1
3366 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3367 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3369 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3371 eif->failed = true;
3372 return false;
3376 else
3378 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3379 was first seen in a non-ELF file. Fortunately, if the symbol
3380 was first seen in an ELF file, we're probably OK unless the
3381 symbol was defined in a non-ELF file. Catch that case here.
3382 FIXME: We're still in trouble if the symbol was first seen in
3383 a dynamic object, and then later in a non-ELF regular object. */
3384 if ((h->root.type == bfd_link_hash_defined
3385 || h->root.type == bfd_link_hash_defweak)
3386 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3387 && (h->root.u.def.section->owner != NULL
3388 ? (bfd_get_flavour (h->root.u.def.section->owner)
3389 != bfd_target_elf_flavour)
3390 : (bfd_is_abs_section (h->root.u.def.section)
3391 && (h->elf_link_hash_flags
3392 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3393 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3396 /* If this is a final link, and the symbol was defined as a common
3397 symbol in a regular object file, and there was no definition in
3398 any dynamic object, then the linker will have allocated space for
3399 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3400 flag will not have been set. */
3401 if (h->root.type == bfd_link_hash_defined
3402 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3403 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3404 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3405 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3406 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3408 /* If -Bsymbolic was used (which means to bind references to global
3409 symbols to the definition within the shared object), and this
3410 symbol was defined in a regular object, then it actually doesn't
3411 need a PLT entry. */
3412 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3413 && eif->info->shared
3414 && eif->info->symbolic
3415 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3417 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3418 h->plt.offset = (bfd_vma) -1;
3421 /* If this is a weak defined symbol in a dynamic object, and we know
3422 the real definition in the dynamic object, copy interesting flags
3423 over to the real definition. */
3424 if (h->weakdef != NULL)
3426 struct elf_link_hash_entry *weakdef;
3428 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3429 || h->root.type == bfd_link_hash_defweak);
3430 weakdef = h->weakdef;
3431 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3432 || weakdef->root.type == bfd_link_hash_defweak);
3433 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3435 /* If the real definition is defined by a regular object file,
3436 don't do anything special. See the longer description in
3437 elf_adjust_dynamic_symbol, below. */
3438 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3439 h->weakdef = NULL;
3440 else
3441 weakdef->elf_link_hash_flags |=
3442 (h->elf_link_hash_flags
3443 & (ELF_LINK_HASH_REF_REGULAR
3444 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3445 | ELF_LINK_NON_GOT_REF));
3448 return true;
3451 /* Make the backend pick a good value for a dynamic symbol. This is
3452 called via elf_link_hash_traverse, and also calls itself
3453 recursively. */
3455 static boolean
3456 elf_adjust_dynamic_symbol (h, data)
3457 struct elf_link_hash_entry *h;
3458 PTR data;
3460 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3461 bfd *dynobj;
3462 struct elf_backend_data *bed;
3464 /* Ignore indirect symbols. These are added by the versioning code. */
3465 if (h->root.type == bfd_link_hash_indirect)
3466 return true;
3468 /* Fix the symbol flags. */
3469 if (! elf_fix_symbol_flags (h, eif))
3470 return false;
3472 /* If this symbol does not require a PLT entry, and it is not
3473 defined by a dynamic object, or is not referenced by a regular
3474 object, ignore it. We do have to handle a weak defined symbol,
3475 even if no regular object refers to it, if we decided to add it
3476 to the dynamic symbol table. FIXME: Do we normally need to worry
3477 about symbols which are defined by one dynamic object and
3478 referenced by another one? */
3479 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3480 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3481 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3482 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3483 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3485 h->plt.offset = (bfd_vma) -1;
3486 return true;
3489 /* If we've already adjusted this symbol, don't do it again. This
3490 can happen via a recursive call. */
3491 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3492 return true;
3494 /* Don't look at this symbol again. Note that we must set this
3495 after checking the above conditions, because we may look at a
3496 symbol once, decide not to do anything, and then get called
3497 recursively later after REF_REGULAR is set below. */
3498 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3500 /* If this is a weak definition, and we know a real definition, and
3501 the real symbol is not itself defined by a regular object file,
3502 then get a good value for the real definition. We handle the
3503 real symbol first, for the convenience of the backend routine.
3505 Note that there is a confusing case here. If the real definition
3506 is defined by a regular object file, we don't get the real symbol
3507 from the dynamic object, but we do get the weak symbol. If the
3508 processor backend uses a COPY reloc, then if some routine in the
3509 dynamic object changes the real symbol, we will not see that
3510 change in the corresponding weak symbol. This is the way other
3511 ELF linkers work as well, and seems to be a result of the shared
3512 library model.
3514 I will clarify this issue. Most SVR4 shared libraries define the
3515 variable _timezone and define timezone as a weak synonym. The
3516 tzset call changes _timezone. If you write
3517 extern int timezone;
3518 int _timezone = 5;
3519 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3520 you might expect that, since timezone is a synonym for _timezone,
3521 the same number will print both times. However, if the processor
3522 backend uses a COPY reloc, then actually timezone will be copied
3523 into your process image, and, since you define _timezone
3524 yourself, _timezone will not. Thus timezone and _timezone will
3525 wind up at different memory locations. The tzset call will set
3526 _timezone, leaving timezone unchanged. */
3528 if (h->weakdef != NULL)
3530 /* If we get to this point, we know there is an implicit
3531 reference by a regular object file via the weak symbol H.
3532 FIXME: Is this really true? What if the traversal finds
3533 H->WEAKDEF before it finds H? */
3534 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3536 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3537 return false;
3540 /* If a symbol has no type and no size and does not require a PLT
3541 entry, then we are probably about to do the wrong thing here: we
3542 are probably going to create a COPY reloc for an empty object.
3543 This case can arise when a shared object is built with assembly
3544 code, and the assembly code fails to set the symbol type. */
3545 if (h->size == 0
3546 && h->type == STT_NOTYPE
3547 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3548 (*_bfd_error_handler)
3549 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3550 h->root.root.string);
3552 dynobj = elf_hash_table (eif->info)->dynobj;
3553 bed = get_elf_backend_data (dynobj);
3554 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3556 eif->failed = true;
3557 return false;
3560 return true;
3563 /* This routine is used to export all defined symbols into the dynamic
3564 symbol table. It is called via elf_link_hash_traverse. */
3566 static boolean
3567 elf_export_symbol (h, data)
3568 struct elf_link_hash_entry *h;
3569 PTR data;
3571 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3573 /* Ignore indirect symbols. These are added by the versioning code. */
3574 if (h->root.type == bfd_link_hash_indirect)
3575 return true;
3577 if (h->dynindx == -1
3578 && (h->elf_link_hash_flags
3579 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3581 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3583 eif->failed = true;
3584 return false;
3588 return true;
3591 /* Look through the symbols which are defined in other shared
3592 libraries and referenced here. Update the list of version
3593 dependencies. This will be put into the .gnu.version_r section.
3594 This function is called via elf_link_hash_traverse. */
3596 static boolean
3597 elf_link_find_version_dependencies (h, data)
3598 struct elf_link_hash_entry *h;
3599 PTR data;
3601 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3602 Elf_Internal_Verneed *t;
3603 Elf_Internal_Vernaux *a;
3605 /* We only care about symbols defined in shared objects with version
3606 information. */
3607 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3608 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3609 || h->dynindx == -1
3610 || h->verinfo.verdef == NULL)
3611 return true;
3613 /* See if we already know about this version. */
3614 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3616 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3617 continue;
3619 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3620 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3621 return true;
3623 break;
3626 /* This is a new version. Add it to tree we are building. */
3628 if (t == NULL)
3630 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3631 if (t == NULL)
3633 rinfo->failed = true;
3634 return false;
3637 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3638 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3639 elf_tdata (rinfo->output_bfd)->verref = t;
3642 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3644 /* Note that we are copying a string pointer here, and testing it
3645 above. If bfd_elf_string_from_elf_section is ever changed to
3646 discard the string data when low in memory, this will have to be
3647 fixed. */
3648 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3650 a->vna_flags = h->verinfo.verdef->vd_flags;
3651 a->vna_nextptr = t->vn_auxptr;
3653 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3654 ++rinfo->vers;
3656 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3658 t->vn_auxptr = a;
3660 return true;
3663 /* Figure out appropriate versions for all the symbols. We may not
3664 have the version number script until we have read all of the input
3665 files, so until that point we don't know which symbols should be
3666 local. This function is called via elf_link_hash_traverse. */
3668 static boolean
3669 elf_link_assign_sym_version (h, data)
3670 struct elf_link_hash_entry *h;
3671 PTR data;
3673 struct elf_assign_sym_version_info *sinfo =
3674 (struct elf_assign_sym_version_info *) data;
3675 struct bfd_link_info *info = sinfo->info;
3676 struct elf_info_failed eif;
3677 char *p;
3679 /* Fix the symbol flags. */
3680 eif.failed = false;
3681 eif.info = info;
3682 if (! elf_fix_symbol_flags (h, &eif))
3684 if (eif.failed)
3685 sinfo->failed = true;
3686 return false;
3689 /* We only need version numbers for symbols defined in regular
3690 objects. */
3691 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3692 return true;
3694 p = strchr (h->root.root.string, ELF_VER_CHR);
3695 if (p != NULL && h->verinfo.vertree == NULL)
3697 struct bfd_elf_version_tree *t;
3698 boolean hidden;
3700 hidden = true;
3702 /* There are two consecutive ELF_VER_CHR characters if this is
3703 not a hidden symbol. */
3704 ++p;
3705 if (*p == ELF_VER_CHR)
3707 hidden = false;
3708 ++p;
3711 /* If there is no version string, we can just return out. */
3712 if (*p == '\0')
3714 if (hidden)
3715 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3716 return true;
3719 /* Look for the version. If we find it, it is no longer weak. */
3720 for (t = sinfo->verdefs; t != NULL; t = t->next)
3722 if (strcmp (t->name, p) == 0)
3724 int len;
3725 char *alc;
3726 struct bfd_elf_version_expr *d;
3728 len = p - h->root.root.string;
3729 alc = bfd_alloc (sinfo->output_bfd, len);
3730 if (alc == NULL)
3731 return false;
3732 strncpy (alc, h->root.root.string, len - 1);
3733 alc[len - 1] = '\0';
3734 if (alc[len - 2] == ELF_VER_CHR)
3735 alc[len - 2] = '\0';
3737 h->verinfo.vertree = t;
3738 t->used = true;
3739 d = NULL;
3741 if (t->globals != NULL)
3743 for (d = t->globals; d != NULL; d = d->next)
3744 if ((*d->match) (d, alc))
3745 break;
3748 /* See if there is anything to force this symbol to
3749 local scope. */
3750 if (d == NULL && t->locals != NULL)
3752 for (d = t->locals; d != NULL; d = d->next)
3754 if ((*d->match) (d, alc))
3756 if (h->dynindx != -1
3757 && info->shared
3758 && ! sinfo->export_dynamic)
3760 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3761 h->elf_link_hash_flags &=~
3762 ELF_LINK_HASH_NEEDS_PLT;
3763 h->dynindx = -1;
3764 h->plt.offset = (bfd_vma) -1;
3765 /* FIXME: The name of the symbol has
3766 already been recorded in the dynamic
3767 string table section. */
3770 break;
3775 bfd_release (sinfo->output_bfd, alc);
3776 break;
3780 /* If we are building an application, we need to create a
3781 version node for this version. */
3782 if (t == NULL && ! info->shared)
3784 struct bfd_elf_version_tree **pp;
3785 int version_index;
3787 /* If we aren't going to export this symbol, we don't need
3788 to worry about it. */
3789 if (h->dynindx == -1)
3790 return true;
3792 t = ((struct bfd_elf_version_tree *)
3793 bfd_alloc (sinfo->output_bfd, sizeof *t));
3794 if (t == NULL)
3796 sinfo->failed = true;
3797 return false;
3800 t->next = NULL;
3801 t->name = p;
3802 t->globals = NULL;
3803 t->locals = NULL;
3804 t->deps = NULL;
3805 t->name_indx = (unsigned int) -1;
3806 t->used = true;
3808 version_index = 1;
3809 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3810 ++version_index;
3811 t->vernum = version_index;
3813 *pp = t;
3815 h->verinfo.vertree = t;
3817 else if (t == NULL)
3819 /* We could not find the version for a symbol when
3820 generating a shared archive. Return an error. */
3821 (*_bfd_error_handler)
3822 (_("%s: undefined versioned symbol name %s"),
3823 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3824 bfd_set_error (bfd_error_bad_value);
3825 sinfo->failed = true;
3826 return false;
3829 if (hidden)
3830 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3833 /* If we don't have a version for this symbol, see if we can find
3834 something. */
3835 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3837 struct bfd_elf_version_tree *t;
3838 struct bfd_elf_version_tree *deflt;
3839 struct bfd_elf_version_expr *d;
3841 /* See if can find what version this symbol is in. If the
3842 symbol is supposed to be local, then don't actually register
3843 it. */
3844 deflt = NULL;
3845 for (t = sinfo->verdefs; t != NULL; t = t->next)
3847 if (t->globals != NULL)
3849 for (d = t->globals; d != NULL; d = d->next)
3851 if ((*d->match) (d, h->root.root.string))
3853 h->verinfo.vertree = t;
3854 break;
3858 if (d != NULL)
3859 break;
3862 if (t->locals != NULL)
3864 for (d = t->locals; d != NULL; d = d->next)
3866 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3867 deflt = t;
3868 else if ((*d->match) (d, h->root.root.string))
3870 h->verinfo.vertree = t;
3871 if (h->dynindx != -1
3872 && info->shared
3873 && ! sinfo->export_dynamic)
3875 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3876 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3877 h->dynindx = -1;
3878 h->plt.offset = (bfd_vma) -1;
3879 /* FIXME: The name of the symbol has already
3880 been recorded in the dynamic string table
3881 section. */
3883 break;
3887 if (d != NULL)
3888 break;
3892 if (deflt != NULL && h->verinfo.vertree == NULL)
3894 h->verinfo.vertree = deflt;
3895 if (h->dynindx != -1
3896 && info->shared
3897 && ! sinfo->export_dynamic)
3899 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3900 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3901 h->dynindx = -1;
3902 h->plt.offset = (bfd_vma) -1;
3903 /* FIXME: The name of the symbol has already been
3904 recorded in the dynamic string table section. */
3909 return true;
3912 /* Final phase of ELF linker. */
3914 /* A structure we use to avoid passing large numbers of arguments. */
3916 struct elf_final_link_info
3918 /* General link information. */
3919 struct bfd_link_info *info;
3920 /* Output BFD. */
3921 bfd *output_bfd;
3922 /* Symbol string table. */
3923 struct bfd_strtab_hash *symstrtab;
3924 /* .dynsym section. */
3925 asection *dynsym_sec;
3926 /* .hash section. */
3927 asection *hash_sec;
3928 /* symbol version section (.gnu.version). */
3929 asection *symver_sec;
3930 /* Buffer large enough to hold contents of any section. */
3931 bfd_byte *contents;
3932 /* Buffer large enough to hold external relocs of any section. */
3933 PTR external_relocs;
3934 /* Buffer large enough to hold internal relocs of any section. */
3935 Elf_Internal_Rela *internal_relocs;
3936 /* Buffer large enough to hold external local symbols of any input
3937 BFD. */
3938 Elf_External_Sym *external_syms;
3939 /* Buffer large enough to hold internal local symbols of any input
3940 BFD. */
3941 Elf_Internal_Sym *internal_syms;
3942 /* Array large enough to hold a symbol index for each local symbol
3943 of any input BFD. */
3944 long *indices;
3945 /* Array large enough to hold a section pointer for each local
3946 symbol of any input BFD. */
3947 asection **sections;
3948 /* Buffer to hold swapped out symbols. */
3949 Elf_External_Sym *symbuf;
3950 /* Number of swapped out symbols in buffer. */
3951 size_t symbuf_count;
3952 /* Number of symbols which fit in symbuf. */
3953 size_t symbuf_size;
3956 static boolean elf_link_output_sym
3957 PARAMS ((struct elf_final_link_info *, const char *,
3958 Elf_Internal_Sym *, asection *));
3959 static boolean elf_link_flush_output_syms
3960 PARAMS ((struct elf_final_link_info *));
3961 static boolean elf_link_output_extsym
3962 PARAMS ((struct elf_link_hash_entry *, PTR));
3963 static boolean elf_link_input_bfd
3964 PARAMS ((struct elf_final_link_info *, bfd *));
3965 static boolean elf_reloc_link_order
3966 PARAMS ((bfd *, struct bfd_link_info *, asection *,
3967 struct bfd_link_order *));
3969 /* This struct is used to pass information to elf_link_output_extsym. */
3971 struct elf_outext_info
3973 boolean failed;
3974 boolean localsyms;
3975 struct elf_final_link_info *finfo;
3978 /* Compute the size of, and allocate space for, REL_HDR which is the
3979 section header for a section containing relocations for O. */
3981 static boolean
3982 elf_link_size_reloc_section (abfd, rel_hdr, o)
3983 bfd *abfd;
3984 Elf_Internal_Shdr *rel_hdr;
3985 asection *o;
3987 register struct elf_link_hash_entry **p, **pend;
3988 unsigned reloc_count;
3990 /* Figure out how many relocations there will be. */
3991 if (rel_hdr == &elf_section_data (o)->rel_hdr)
3992 reloc_count = elf_section_data (o)->rel_count;
3993 else
3994 reloc_count = elf_section_data (o)->rel_count2;
3996 /* That allows us to calculate the size of the section. */
3997 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
3999 /* The contents field must last into write_object_contents, so we
4000 allocate it with bfd_alloc rather than malloc. */
4001 rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
4002 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
4003 return false;
4005 /* We only allocate one set of hash entries, so we only do it the
4006 first time we are called. */
4007 if (elf_section_data (o)->rel_hashes == NULL)
4009 p = ((struct elf_link_hash_entry **)
4010 bfd_malloc (o->reloc_count
4011 * sizeof (struct elf_link_hash_entry *)));
4012 if (p == NULL && o->reloc_count != 0)
4013 return false;
4015 elf_section_data (o)->rel_hashes = p;
4016 pend = p + o->reloc_count;
4017 for (; p < pend; p++)
4018 *p = NULL;
4021 return true;
4024 /* When performing a relocateable link, the input relocations are
4025 preserved. But, if they reference global symbols, the indices
4026 referenced must be updated. Update all the relocations in
4027 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
4029 static void
4030 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
4031 bfd *abfd;
4032 Elf_Internal_Shdr *rel_hdr;
4033 unsigned int count;
4034 struct elf_link_hash_entry **rel_hash;
4036 unsigned int i;
4038 for (i = 0; i < count; i++, rel_hash++)
4040 if (*rel_hash == NULL)
4041 continue;
4043 BFD_ASSERT ((*rel_hash)->indx >= 0);
4045 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4047 Elf_External_Rel *erel;
4048 Elf_Internal_Rel irel;
4050 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4051 elf_swap_reloc_in (abfd, erel, &irel);
4052 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4053 ELF_R_TYPE (irel.r_info));
4054 elf_swap_reloc_out (abfd, &irel, erel);
4056 else
4058 Elf_External_Rela *erela;
4059 Elf_Internal_Rela irela;
4061 BFD_ASSERT (rel_hdr->sh_entsize
4062 == sizeof (Elf_External_Rela));
4064 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4065 elf_swap_reloca_in (abfd, erela, &irela);
4066 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4067 ELF_R_TYPE (irela.r_info));
4068 elf_swap_reloca_out (abfd, &irela, erela);
4073 /* Do the final step of an ELF link. */
4075 boolean
4076 elf_bfd_final_link (abfd, info)
4077 bfd *abfd;
4078 struct bfd_link_info *info;
4080 boolean dynamic;
4081 bfd *dynobj;
4082 struct elf_final_link_info finfo;
4083 register asection *o;
4084 register struct bfd_link_order *p;
4085 register bfd *sub;
4086 size_t max_contents_size;
4087 size_t max_external_reloc_size;
4088 size_t max_internal_reloc_count;
4089 size_t max_sym_count;
4090 file_ptr off;
4091 Elf_Internal_Sym elfsym;
4092 unsigned int i;
4093 Elf_Internal_Shdr *symtab_hdr;
4094 Elf_Internal_Shdr *symstrtab_hdr;
4095 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4096 struct elf_outext_info eoinfo;
4098 if (info->shared)
4099 abfd->flags |= DYNAMIC;
4101 dynamic = elf_hash_table (info)->dynamic_sections_created;
4102 dynobj = elf_hash_table (info)->dynobj;
4104 finfo.info = info;
4105 finfo.output_bfd = abfd;
4106 finfo.symstrtab = elf_stringtab_init ();
4107 if (finfo.symstrtab == NULL)
4108 return false;
4110 if (! dynamic)
4112 finfo.dynsym_sec = NULL;
4113 finfo.hash_sec = NULL;
4114 finfo.symver_sec = NULL;
4116 else
4118 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4119 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4120 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4121 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4122 /* Note that it is OK if symver_sec is NULL. */
4125 finfo.contents = NULL;
4126 finfo.external_relocs = NULL;
4127 finfo.internal_relocs = NULL;
4128 finfo.external_syms = NULL;
4129 finfo.internal_syms = NULL;
4130 finfo.indices = NULL;
4131 finfo.sections = NULL;
4132 finfo.symbuf = NULL;
4133 finfo.symbuf_count = 0;
4135 /* Count up the number of relocations we will output for each output
4136 section, so that we know the sizes of the reloc sections. We
4137 also figure out some maximum sizes. */
4138 max_contents_size = 0;
4139 max_external_reloc_size = 0;
4140 max_internal_reloc_count = 0;
4141 max_sym_count = 0;
4142 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4144 o->reloc_count = 0;
4146 for (p = o->link_order_head; p != NULL; p = p->next)
4148 if (p->type == bfd_section_reloc_link_order
4149 || p->type == bfd_symbol_reloc_link_order)
4150 ++o->reloc_count;
4151 else if (p->type == bfd_indirect_link_order)
4153 asection *sec;
4155 sec = p->u.indirect.section;
4157 /* Mark all sections which are to be included in the
4158 link. This will normally be every section. We need
4159 to do this so that we can identify any sections which
4160 the linker has decided to not include. */
4161 sec->linker_mark = true;
4163 if (info->relocateable)
4164 o->reloc_count += sec->reloc_count;
4166 if (sec->_raw_size > max_contents_size)
4167 max_contents_size = sec->_raw_size;
4168 if (sec->_cooked_size > max_contents_size)
4169 max_contents_size = sec->_cooked_size;
4171 /* We are interested in just local symbols, not all
4172 symbols. */
4173 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4174 && (sec->owner->flags & DYNAMIC) == 0)
4176 size_t sym_count;
4178 if (elf_bad_symtab (sec->owner))
4179 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4180 / sizeof (Elf_External_Sym));
4181 else
4182 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4184 if (sym_count > max_sym_count)
4185 max_sym_count = sym_count;
4187 if ((sec->flags & SEC_RELOC) != 0)
4189 size_t ext_size;
4191 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4192 if (ext_size > max_external_reloc_size)
4193 max_external_reloc_size = ext_size;
4194 if (sec->reloc_count > max_internal_reloc_count)
4195 max_internal_reloc_count = sec->reloc_count;
4201 if (o->reloc_count > 0)
4202 o->flags |= SEC_RELOC;
4203 else
4205 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4206 set it (this is probably a bug) and if it is set
4207 assign_section_numbers will create a reloc section. */
4208 o->flags &=~ SEC_RELOC;
4211 /* If the SEC_ALLOC flag is not set, force the section VMA to
4212 zero. This is done in elf_fake_sections as well, but forcing
4213 the VMA to 0 here will ensure that relocs against these
4214 sections are handled correctly. */
4215 if ((o->flags & SEC_ALLOC) == 0
4216 && ! o->user_set_vma)
4217 o->vma = 0;
4220 /* Figure out the file positions for everything but the symbol table
4221 and the relocs. We set symcount to force assign_section_numbers
4222 to create a symbol table. */
4223 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4224 BFD_ASSERT (! abfd->output_has_begun);
4225 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4226 goto error_return;
4228 /* Figure out how many relocations we will have in each section.
4229 Just using RELOC_COUNT isn't good enough since that doesn't
4230 maintain a separate value for REL vs. RELA relocations. */
4231 if (info->relocateable)
4232 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4233 for (o = sub->sections; o != NULL; o = o->next)
4235 asection *output_section;
4237 if (! o->linker_mark)
4239 /* This section was omitted from the link. */
4240 continue;
4243 output_section = o->output_section;
4245 if (output_section != NULL
4246 && (o->flags & SEC_RELOC) != 0)
4248 struct bfd_elf_section_data *esdi
4249 = elf_section_data (o);
4250 struct bfd_elf_section_data *esdo
4251 = elf_section_data (output_section);
4252 unsigned int *rel_count;
4253 unsigned int *rel_count2;
4255 /* We must be careful to add the relocation froms the
4256 input section to the right output count. */
4257 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4259 rel_count = &esdo->rel_count;
4260 rel_count2 = &esdo->rel_count2;
4262 else
4264 rel_count = &esdo->rel_count2;
4265 rel_count2 = &esdo->rel_count;
4268 *rel_count += (esdi->rel_hdr.sh_size
4269 / esdi->rel_hdr.sh_entsize);
4270 if (esdi->rel_hdr2)
4271 *rel_count2 += (esdi->rel_hdr2->sh_size
4272 / esdi->rel_hdr2->sh_entsize);
4276 /* That created the reloc sections. Set their sizes, and assign
4277 them file positions, and allocate some buffers. */
4278 for (o = abfd->sections; o != NULL; o = o->next)
4280 if ((o->flags & SEC_RELOC) != 0)
4282 if (!elf_link_size_reloc_section (abfd,
4283 &elf_section_data (o)->rel_hdr,
4285 goto error_return;
4287 if (elf_section_data (o)->rel_hdr2
4288 && !elf_link_size_reloc_section (abfd,
4289 elf_section_data (o)->rel_hdr2,
4291 goto error_return;
4294 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4295 to count upwards while actually outputting the relocations. */
4296 elf_section_data (o)->rel_count = 0;
4297 elf_section_data (o)->rel_count2 = 0;
4300 _bfd_elf_assign_file_positions_for_relocs (abfd);
4302 /* We have now assigned file positions for all the sections except
4303 .symtab and .strtab. We start the .symtab section at the current
4304 file position, and write directly to it. We build the .strtab
4305 section in memory. */
4306 bfd_get_symcount (abfd) = 0;
4307 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4308 /* sh_name is set in prep_headers. */
4309 symtab_hdr->sh_type = SHT_SYMTAB;
4310 symtab_hdr->sh_flags = 0;
4311 symtab_hdr->sh_addr = 0;
4312 symtab_hdr->sh_size = 0;
4313 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4314 /* sh_link is set in assign_section_numbers. */
4315 /* sh_info is set below. */
4316 /* sh_offset is set just below. */
4317 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4319 off = elf_tdata (abfd)->next_file_pos;
4320 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4322 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4323 incorrect. We do not yet know the size of the .symtab section.
4324 We correct next_file_pos below, after we do know the size. */
4326 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4327 continuously seeking to the right position in the file. */
4328 if (! info->keep_memory || max_sym_count < 20)
4329 finfo.symbuf_size = 20;
4330 else
4331 finfo.symbuf_size = max_sym_count;
4332 finfo.symbuf = ((Elf_External_Sym *)
4333 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4334 if (finfo.symbuf == NULL)
4335 goto error_return;
4337 /* Start writing out the symbol table. The first symbol is always a
4338 dummy symbol. */
4339 if (info->strip != strip_all || info->relocateable)
4341 elfsym.st_value = 0;
4342 elfsym.st_size = 0;
4343 elfsym.st_info = 0;
4344 elfsym.st_other = 0;
4345 elfsym.st_shndx = SHN_UNDEF;
4346 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4347 &elfsym, bfd_und_section_ptr))
4348 goto error_return;
4351 #if 0
4352 /* Some standard ELF linkers do this, but we don't because it causes
4353 bootstrap comparison failures. */
4354 /* Output a file symbol for the output file as the second symbol.
4355 We output this even if we are discarding local symbols, although
4356 I'm not sure if this is correct. */
4357 elfsym.st_value = 0;
4358 elfsym.st_size = 0;
4359 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4360 elfsym.st_other = 0;
4361 elfsym.st_shndx = SHN_ABS;
4362 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4363 &elfsym, bfd_abs_section_ptr))
4364 goto error_return;
4365 #endif
4367 /* Output a symbol for each section. We output these even if we are
4368 discarding local symbols, since they are used for relocs. These
4369 symbols have no names. We store the index of each one in the
4370 index field of the section, so that we can find it again when
4371 outputting relocs. */
4372 if (info->strip != strip_all || info->relocateable)
4374 elfsym.st_size = 0;
4375 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4376 elfsym.st_other = 0;
4377 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4379 o = section_from_elf_index (abfd, i);
4380 if (o != NULL)
4381 o->target_index = bfd_get_symcount (abfd);
4382 elfsym.st_shndx = i;
4383 if (info->relocateable || o == NULL)
4384 elfsym.st_value = 0;
4385 else
4386 elfsym.st_value = o->vma;
4387 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4388 &elfsym, o))
4389 goto error_return;
4393 /* Allocate some memory to hold information read in from the input
4394 files. */
4395 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4396 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4397 finfo.internal_relocs = ((Elf_Internal_Rela *)
4398 bfd_malloc (max_internal_reloc_count
4399 * sizeof (Elf_Internal_Rela)
4400 * bed->s->int_rels_per_ext_rel));
4401 finfo.external_syms = ((Elf_External_Sym *)
4402 bfd_malloc (max_sym_count
4403 * sizeof (Elf_External_Sym)));
4404 finfo.internal_syms = ((Elf_Internal_Sym *)
4405 bfd_malloc (max_sym_count
4406 * sizeof (Elf_Internal_Sym)));
4407 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4408 finfo.sections = ((asection **)
4409 bfd_malloc (max_sym_count * sizeof (asection *)));
4410 if ((finfo.contents == NULL && max_contents_size != 0)
4411 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4412 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4413 || (finfo.external_syms == NULL && max_sym_count != 0)
4414 || (finfo.internal_syms == NULL && max_sym_count != 0)
4415 || (finfo.indices == NULL && max_sym_count != 0)
4416 || (finfo.sections == NULL && max_sym_count != 0))
4417 goto error_return;
4419 /* Since ELF permits relocations to be against local symbols, we
4420 must have the local symbols available when we do the relocations.
4421 Since we would rather only read the local symbols once, and we
4422 would rather not keep them in memory, we handle all the
4423 relocations for a single input file at the same time.
4425 Unfortunately, there is no way to know the total number of local
4426 symbols until we have seen all of them, and the local symbol
4427 indices precede the global symbol indices. This means that when
4428 we are generating relocateable output, and we see a reloc against
4429 a global symbol, we can not know the symbol index until we have
4430 finished examining all the local symbols to see which ones we are
4431 going to output. To deal with this, we keep the relocations in
4432 memory, and don't output them until the end of the link. This is
4433 an unfortunate waste of memory, but I don't see a good way around
4434 it. Fortunately, it only happens when performing a relocateable
4435 link, which is not the common case. FIXME: If keep_memory is set
4436 we could write the relocs out and then read them again; I don't
4437 know how bad the memory loss will be. */
4439 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4440 sub->output_has_begun = false;
4441 for (o = abfd->sections; o != NULL; o = o->next)
4443 for (p = o->link_order_head; p != NULL; p = p->next)
4445 if (p->type == bfd_indirect_link_order
4446 && (bfd_get_flavour (p->u.indirect.section->owner)
4447 == bfd_target_elf_flavour))
4449 sub = p->u.indirect.section->owner;
4450 if (! sub->output_has_begun)
4452 if (! elf_link_input_bfd (&finfo, sub))
4453 goto error_return;
4454 sub->output_has_begun = true;
4457 else if (p->type == bfd_section_reloc_link_order
4458 || p->type == bfd_symbol_reloc_link_order)
4460 if (! elf_reloc_link_order (abfd, info, o, p))
4461 goto error_return;
4463 else
4465 if (! _bfd_default_link_order (abfd, info, o, p))
4466 goto error_return;
4471 /* That wrote out all the local symbols. Finish up the symbol table
4472 with the global symbols. */
4474 if (info->strip != strip_all && info->shared)
4476 /* Output any global symbols that got converted to local in a
4477 version script. We do this in a separate step since ELF
4478 requires all local symbols to appear prior to any global
4479 symbols. FIXME: We should only do this if some global
4480 symbols were, in fact, converted to become local. FIXME:
4481 Will this work correctly with the Irix 5 linker? */
4482 eoinfo.failed = false;
4483 eoinfo.finfo = &finfo;
4484 eoinfo.localsyms = true;
4485 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4486 (PTR) &eoinfo);
4487 if (eoinfo.failed)
4488 return false;
4491 /* The sh_info field records the index of the first non local symbol. */
4492 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4494 if (dynamic)
4496 Elf_Internal_Sym sym;
4497 Elf_External_Sym *dynsym =
4498 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4499 long last_local = 0;
4501 /* Write out the section symbols for the output sections. */
4502 if (info->shared)
4504 asection *s;
4506 sym.st_size = 0;
4507 sym.st_name = 0;
4508 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4509 sym.st_other = 0;
4511 for (s = abfd->sections; s != NULL; s = s->next)
4513 int indx;
4514 indx = elf_section_data (s)->this_idx;
4515 BFD_ASSERT (indx > 0);
4516 sym.st_shndx = indx;
4517 sym.st_value = s->vma;
4519 elf_swap_symbol_out (abfd, &sym,
4520 dynsym + elf_section_data (s)->dynindx);
4523 last_local = bfd_count_sections (abfd);
4526 /* Write out the local dynsyms. */
4527 if (elf_hash_table (info)->dynlocal)
4529 struct elf_link_local_dynamic_entry *e;
4530 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4532 asection *s;
4534 sym.st_size = e->isym.st_size;
4535 sym.st_other = e->isym.st_other;
4537 /* Copy the internal symbol as is.
4538 Note that we saved a word of storage and overwrote
4539 the original st_name with the dynstr_index. */
4540 sym = e->isym;
4542 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4544 s = bfd_section_from_elf_index (e->input_bfd,
4545 e->isym.st_shndx);
4547 sym.st_shndx =
4548 elf_section_data (s->output_section)->this_idx;
4549 sym.st_value = (s->output_section->vma
4550 + s->output_offset
4551 + e->isym.st_value);
4554 if (last_local < e->dynindx)
4555 last_local = e->dynindx;
4557 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4561 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4562 last_local + 1;
4565 /* We get the global symbols from the hash table. */
4566 eoinfo.failed = false;
4567 eoinfo.localsyms = false;
4568 eoinfo.finfo = &finfo;
4569 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4570 (PTR) &eoinfo);
4571 if (eoinfo.failed)
4572 return false;
4574 /* If backend needs to output some symbols not present in the hash
4575 table, do it now. */
4576 if (bed->elf_backend_output_arch_syms)
4578 if (! (*bed->elf_backend_output_arch_syms)
4579 (abfd, info, (PTR) &finfo,
4580 (boolean (*) PARAMS ((PTR, const char *,
4581 Elf_Internal_Sym *, asection *)))
4582 elf_link_output_sym))
4583 return false;
4586 /* Flush all symbols to the file. */
4587 if (! elf_link_flush_output_syms (&finfo))
4588 return false;
4590 /* Now we know the size of the symtab section. */
4591 off += symtab_hdr->sh_size;
4593 /* Finish up and write out the symbol string table (.strtab)
4594 section. */
4595 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4596 /* sh_name was set in prep_headers. */
4597 symstrtab_hdr->sh_type = SHT_STRTAB;
4598 symstrtab_hdr->sh_flags = 0;
4599 symstrtab_hdr->sh_addr = 0;
4600 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4601 symstrtab_hdr->sh_entsize = 0;
4602 symstrtab_hdr->sh_link = 0;
4603 symstrtab_hdr->sh_info = 0;
4604 /* sh_offset is set just below. */
4605 symstrtab_hdr->sh_addralign = 1;
4607 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4608 elf_tdata (abfd)->next_file_pos = off;
4610 if (bfd_get_symcount (abfd) > 0)
4612 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4613 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4614 return false;
4617 /* Adjust the relocs to have the correct symbol indices. */
4618 for (o = abfd->sections; o != NULL; o = o->next)
4620 if ((o->flags & SEC_RELOC) == 0)
4621 continue;
4623 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4624 elf_section_data (o)->rel_count,
4625 elf_section_data (o)->rel_hashes);
4626 if (elf_section_data (o)->rel_hdr2 != NULL)
4627 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4628 elf_section_data (o)->rel_count2,
4629 (elf_section_data (o)->rel_hashes
4630 + elf_section_data (o)->rel_count));
4632 /* Set the reloc_count field to 0 to prevent write_relocs from
4633 trying to swap the relocs out itself. */
4634 o->reloc_count = 0;
4637 /* If we are linking against a dynamic object, or generating a
4638 shared library, finish up the dynamic linking information. */
4639 if (dynamic)
4641 Elf_External_Dyn *dyncon, *dynconend;
4643 /* Fix up .dynamic entries. */
4644 o = bfd_get_section_by_name (dynobj, ".dynamic");
4645 BFD_ASSERT (o != NULL);
4647 dyncon = (Elf_External_Dyn *) o->contents;
4648 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4649 for (; dyncon < dynconend; dyncon++)
4651 Elf_Internal_Dyn dyn;
4652 const char *name;
4653 unsigned int type;
4655 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4657 switch (dyn.d_tag)
4659 default:
4660 break;
4661 case DT_INIT:
4662 name = info->init_function;
4663 goto get_sym;
4664 case DT_FINI:
4665 name = info->fini_function;
4666 get_sym:
4668 struct elf_link_hash_entry *h;
4670 h = elf_link_hash_lookup (elf_hash_table (info), name,
4671 false, false, true);
4672 if (h != NULL
4673 && (h->root.type == bfd_link_hash_defined
4674 || h->root.type == bfd_link_hash_defweak))
4676 dyn.d_un.d_val = h->root.u.def.value;
4677 o = h->root.u.def.section;
4678 if (o->output_section != NULL)
4679 dyn.d_un.d_val += (o->output_section->vma
4680 + o->output_offset);
4681 else
4683 /* The symbol is imported from another shared
4684 library and does not apply to this one. */
4685 dyn.d_un.d_val = 0;
4688 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4691 break;
4693 case DT_HASH:
4694 name = ".hash";
4695 goto get_vma;
4696 case DT_STRTAB:
4697 name = ".dynstr";
4698 goto get_vma;
4699 case DT_SYMTAB:
4700 name = ".dynsym";
4701 goto get_vma;
4702 case DT_VERDEF:
4703 name = ".gnu.version_d";
4704 goto get_vma;
4705 case DT_VERNEED:
4706 name = ".gnu.version_r";
4707 goto get_vma;
4708 case DT_VERSYM:
4709 name = ".gnu.version";
4710 get_vma:
4711 o = bfd_get_section_by_name (abfd, name);
4712 BFD_ASSERT (o != NULL);
4713 dyn.d_un.d_ptr = o->vma;
4714 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4715 break;
4717 case DT_REL:
4718 case DT_RELA:
4719 case DT_RELSZ:
4720 case DT_RELASZ:
4721 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4722 type = SHT_REL;
4723 else
4724 type = SHT_RELA;
4725 dyn.d_un.d_val = 0;
4726 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4728 Elf_Internal_Shdr *hdr;
4730 hdr = elf_elfsections (abfd)[i];
4731 if (hdr->sh_type == type
4732 && (hdr->sh_flags & SHF_ALLOC) != 0)
4734 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4735 dyn.d_un.d_val += hdr->sh_size;
4736 else
4738 if (dyn.d_un.d_val == 0
4739 || hdr->sh_addr < dyn.d_un.d_val)
4740 dyn.d_un.d_val = hdr->sh_addr;
4744 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4745 break;
4750 /* If we have created any dynamic sections, then output them. */
4751 if (dynobj != NULL)
4753 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4754 goto error_return;
4756 for (o = dynobj->sections; o != NULL; o = o->next)
4758 if ((o->flags & SEC_HAS_CONTENTS) == 0
4759 || o->_raw_size == 0)
4760 continue;
4761 if ((o->flags & SEC_LINKER_CREATED) == 0)
4763 /* At this point, we are only interested in sections
4764 created by elf_link_create_dynamic_sections. */
4765 continue;
4767 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4768 != SHT_STRTAB)
4769 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4771 if (! bfd_set_section_contents (abfd, o->output_section,
4772 o->contents, o->output_offset,
4773 o->_raw_size))
4774 goto error_return;
4776 else
4778 file_ptr off;
4780 /* The contents of the .dynstr section are actually in a
4781 stringtab. */
4782 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4783 if (bfd_seek (abfd, off, SEEK_SET) != 0
4784 || ! _bfd_stringtab_emit (abfd,
4785 elf_hash_table (info)->dynstr))
4786 goto error_return;
4791 /* If we have optimized stabs strings, output them. */
4792 if (elf_hash_table (info)->stab_info != NULL)
4794 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4795 goto error_return;
4798 if (finfo.symstrtab != NULL)
4799 _bfd_stringtab_free (finfo.symstrtab);
4800 if (finfo.contents != NULL)
4801 free (finfo.contents);
4802 if (finfo.external_relocs != NULL)
4803 free (finfo.external_relocs);
4804 if (finfo.internal_relocs != NULL)
4805 free (finfo.internal_relocs);
4806 if (finfo.external_syms != NULL)
4807 free (finfo.external_syms);
4808 if (finfo.internal_syms != NULL)
4809 free (finfo.internal_syms);
4810 if (finfo.indices != NULL)
4811 free (finfo.indices);
4812 if (finfo.sections != NULL)
4813 free (finfo.sections);
4814 if (finfo.symbuf != NULL)
4815 free (finfo.symbuf);
4816 for (o = abfd->sections; o != NULL; o = o->next)
4818 if ((o->flags & SEC_RELOC) != 0
4819 && elf_section_data (o)->rel_hashes != NULL)
4820 free (elf_section_data (o)->rel_hashes);
4823 elf_tdata (abfd)->linker = true;
4825 return true;
4827 error_return:
4828 if (finfo.symstrtab != NULL)
4829 _bfd_stringtab_free (finfo.symstrtab);
4830 if (finfo.contents != NULL)
4831 free (finfo.contents);
4832 if (finfo.external_relocs != NULL)
4833 free (finfo.external_relocs);
4834 if (finfo.internal_relocs != NULL)
4835 free (finfo.internal_relocs);
4836 if (finfo.external_syms != NULL)
4837 free (finfo.external_syms);
4838 if (finfo.internal_syms != NULL)
4839 free (finfo.internal_syms);
4840 if (finfo.indices != NULL)
4841 free (finfo.indices);
4842 if (finfo.sections != NULL)
4843 free (finfo.sections);
4844 if (finfo.symbuf != NULL)
4845 free (finfo.symbuf);
4846 for (o = abfd->sections; o != NULL; o = o->next)
4848 if ((o->flags & SEC_RELOC) != 0
4849 && elf_section_data (o)->rel_hashes != NULL)
4850 free (elf_section_data (o)->rel_hashes);
4853 return false;
4856 /* Add a symbol to the output symbol table. */
4858 static boolean
4859 elf_link_output_sym (finfo, name, elfsym, input_sec)
4860 struct elf_final_link_info *finfo;
4861 const char *name;
4862 Elf_Internal_Sym *elfsym;
4863 asection *input_sec;
4865 boolean (*output_symbol_hook) PARAMS ((bfd *,
4866 struct bfd_link_info *info,
4867 const char *,
4868 Elf_Internal_Sym *,
4869 asection *));
4871 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4872 elf_backend_link_output_symbol_hook;
4873 if (output_symbol_hook != NULL)
4875 if (! ((*output_symbol_hook)
4876 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4877 return false;
4880 if (name == (const char *) NULL || *name == '\0')
4881 elfsym->st_name = 0;
4882 else if (input_sec->flags & SEC_EXCLUDE)
4883 elfsym->st_name = 0;
4884 else
4886 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
4887 name, true,
4888 false);
4889 if (elfsym->st_name == (unsigned long) -1)
4890 return false;
4893 if (finfo->symbuf_count >= finfo->symbuf_size)
4895 if (! elf_link_flush_output_syms (finfo))
4896 return false;
4899 elf_swap_symbol_out (finfo->output_bfd, elfsym,
4900 (PTR) (finfo->symbuf + finfo->symbuf_count));
4901 ++finfo->symbuf_count;
4903 ++ bfd_get_symcount (finfo->output_bfd);
4905 return true;
4908 /* Flush the output symbols to the file. */
4910 static boolean
4911 elf_link_flush_output_syms (finfo)
4912 struct elf_final_link_info *finfo;
4914 if (finfo->symbuf_count > 0)
4916 Elf_Internal_Shdr *symtab;
4918 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
4920 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
4921 SEEK_SET) != 0
4922 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
4923 sizeof (Elf_External_Sym), finfo->output_bfd)
4924 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
4925 return false;
4927 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
4929 finfo->symbuf_count = 0;
4932 return true;
4935 /* Add an external symbol to the symbol table. This is called from
4936 the hash table traversal routine. When generating a shared object,
4937 we go through the symbol table twice. The first time we output
4938 anything that might have been forced to local scope in a version
4939 script. The second time we output the symbols that are still
4940 global symbols. */
4942 static boolean
4943 elf_link_output_extsym (h, data)
4944 struct elf_link_hash_entry *h;
4945 PTR data;
4947 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
4948 struct elf_final_link_info *finfo = eoinfo->finfo;
4949 boolean strip;
4950 Elf_Internal_Sym sym;
4951 asection *input_sec;
4953 /* Decide whether to output this symbol in this pass. */
4954 if (eoinfo->localsyms)
4956 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
4957 return true;
4959 else
4961 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
4962 return true;
4965 /* If we are not creating a shared library, and this symbol is
4966 referenced by a shared library but is not defined anywhere, then
4967 warn that it is undefined. If we do not do this, the runtime
4968 linker will complain that the symbol is undefined when the
4969 program is run. We don't have to worry about symbols that are
4970 referenced by regular files, because we will already have issued
4971 warnings for them. */
4972 if (! finfo->info->relocateable
4973 && ! (finfo->info->shared
4974 && !finfo->info->no_undefined)
4975 && h->root.type == bfd_link_hash_undefined
4976 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
4977 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4979 if (! ((*finfo->info->callbacks->undefined_symbol)
4980 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
4981 (asection *) NULL, 0)))
4983 eoinfo->failed = true;
4984 return false;
4988 /* We don't want to output symbols that have never been mentioned by
4989 a regular file, or that we have been told to strip. However, if
4990 h->indx is set to -2, the symbol is used by a reloc and we must
4991 output it. */
4992 if (h->indx == -2)
4993 strip = false;
4994 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
4995 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
4996 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
4997 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
4998 strip = true;
4999 else if (finfo->info->strip == strip_all
5000 || (finfo->info->strip == strip_some
5001 && bfd_hash_lookup (finfo->info->keep_hash,
5002 h->root.root.string,
5003 false, false) == NULL))
5004 strip = true;
5005 else
5006 strip = false;
5008 /* If we're stripping it, and it's not a dynamic symbol, there's
5009 nothing else to do. */
5010 if (strip && h->dynindx == -1)
5011 return true;
5013 sym.st_value = 0;
5014 sym.st_size = h->size;
5015 sym.st_other = h->other;
5016 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5017 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
5018 else if (h->root.type == bfd_link_hash_undefweak
5019 || h->root.type == bfd_link_hash_defweak)
5020 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
5021 else
5022 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
5024 switch (h->root.type)
5026 default:
5027 case bfd_link_hash_new:
5028 abort ();
5029 return false;
5031 case bfd_link_hash_undefined:
5032 input_sec = bfd_und_section_ptr;
5033 sym.st_shndx = SHN_UNDEF;
5034 break;
5036 case bfd_link_hash_undefweak:
5037 input_sec = bfd_und_section_ptr;
5038 sym.st_shndx = SHN_UNDEF;
5039 break;
5041 case bfd_link_hash_defined:
5042 case bfd_link_hash_defweak:
5044 input_sec = h->root.u.def.section;
5045 if (input_sec->output_section != NULL)
5047 sym.st_shndx =
5048 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
5049 input_sec->output_section);
5050 if (sym.st_shndx == (unsigned short) -1)
5052 (*_bfd_error_handler)
5053 (_("%s: could not find output section %s for input section %s"),
5054 bfd_get_filename (finfo->output_bfd),
5055 input_sec->output_section->name,
5056 input_sec->name);
5057 eoinfo->failed = true;
5058 return false;
5061 /* ELF symbols in relocateable files are section relative,
5062 but in nonrelocateable files they are virtual
5063 addresses. */
5064 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5065 if (! finfo->info->relocateable)
5066 sym.st_value += input_sec->output_section->vma;
5068 else
5070 BFD_ASSERT (input_sec->owner == NULL
5071 || (input_sec->owner->flags & DYNAMIC) != 0);
5072 sym.st_shndx = SHN_UNDEF;
5073 input_sec = bfd_und_section_ptr;
5076 break;
5078 case bfd_link_hash_common:
5079 input_sec = h->root.u.c.p->section;
5080 sym.st_shndx = SHN_COMMON;
5081 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5082 break;
5084 case bfd_link_hash_indirect:
5085 /* These symbols are created by symbol versioning. They point
5086 to the decorated version of the name. For example, if the
5087 symbol foo@@GNU_1.2 is the default, which should be used when
5088 foo is used with no version, then we add an indirect symbol
5089 foo which points to foo@@GNU_1.2. We ignore these symbols,
5090 since the indirected symbol is already in the hash table. If
5091 the indirect symbol is non-ELF, fall through and output it. */
5092 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) == 0)
5093 return true;
5095 /* Fall through. */
5096 case bfd_link_hash_warning:
5097 /* We can't represent these symbols in ELF, although a warning
5098 symbol may have come from a .gnu.warning.SYMBOL section. We
5099 just put the target symbol in the hash table. If the target
5100 symbol does not really exist, don't do anything. */
5101 if (h->root.u.i.link->type == bfd_link_hash_new)
5102 return true;
5103 return (elf_link_output_extsym
5104 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5107 /* Give the processor backend a chance to tweak the symbol value,
5108 and also to finish up anything that needs to be done for this
5109 symbol. */
5110 if ((h->dynindx != -1
5111 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5112 && elf_hash_table (finfo->info)->dynamic_sections_created)
5114 struct elf_backend_data *bed;
5116 bed = get_elf_backend_data (finfo->output_bfd);
5117 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5118 (finfo->output_bfd, finfo->info, h, &sym)))
5120 eoinfo->failed = true;
5121 return false;
5125 /* If we are marking the symbol as undefined, and there are no
5126 non-weak references to this symbol from a regular object, then
5127 mark the symbol as weak undefined; if there are non-weak
5128 references, mark the symbol as strong. We can't do this earlier,
5129 because it might not be marked as undefined until the
5130 finish_dynamic_symbol routine gets through with it. */
5131 if (sym.st_shndx == SHN_UNDEF
5132 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5133 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5134 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5136 int bindtype;
5138 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5139 bindtype = STB_GLOBAL;
5140 else
5141 bindtype = STB_WEAK;
5142 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5145 /* If this symbol should be put in the .dynsym section, then put it
5146 there now. We have already know the symbol index. We also fill
5147 in the entry in the .hash section. */
5148 if (h->dynindx != -1
5149 && elf_hash_table (finfo->info)->dynamic_sections_created)
5151 size_t bucketcount;
5152 size_t bucket;
5153 size_t hash_entry_size;
5154 bfd_byte *bucketpos;
5155 bfd_vma chain;
5157 sym.st_name = h->dynstr_index;
5159 elf_swap_symbol_out (finfo->output_bfd, &sym,
5160 (PTR) (((Elf_External_Sym *)
5161 finfo->dynsym_sec->contents)
5162 + h->dynindx));
5164 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5165 bucket = h->elf_hash_value % bucketcount;
5166 hash_entry_size
5167 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5168 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5169 + (bucket + 2) * hash_entry_size);
5170 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5171 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5172 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5173 ((bfd_byte *) finfo->hash_sec->contents
5174 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5176 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5178 Elf_Internal_Versym iversym;
5180 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5182 if (h->verinfo.verdef == NULL)
5183 iversym.vs_vers = 0;
5184 else
5185 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5187 else
5189 if (h->verinfo.vertree == NULL)
5190 iversym.vs_vers = 1;
5191 else
5192 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5195 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5196 iversym.vs_vers |= VERSYM_HIDDEN;
5198 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5199 (((Elf_External_Versym *)
5200 finfo->symver_sec->contents)
5201 + h->dynindx));
5205 /* If we're stripping it, then it was just a dynamic symbol, and
5206 there's nothing else to do. */
5207 if (strip)
5208 return true;
5210 h->indx = bfd_get_symcount (finfo->output_bfd);
5212 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5214 eoinfo->failed = true;
5215 return false;
5218 return true;
5221 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5222 originated from the section given by INPUT_REL_HDR) to the
5223 OUTPUT_BFD. */
5225 static void
5226 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5227 internal_relocs)
5228 bfd *output_bfd;
5229 asection *input_section;
5230 Elf_Internal_Shdr *input_rel_hdr;
5231 Elf_Internal_Rela *internal_relocs;
5233 Elf_Internal_Rela *irela;
5234 Elf_Internal_Rela *irelaend;
5235 Elf_Internal_Shdr *output_rel_hdr;
5236 asection *output_section;
5237 unsigned int *rel_countp = NULL;
5239 output_section = input_section->output_section;
5240 output_rel_hdr = NULL;
5242 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5243 == input_rel_hdr->sh_entsize)
5245 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5246 rel_countp = &elf_section_data (output_section)->rel_count;
5248 else if (elf_section_data (output_section)->rel_hdr2
5249 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5250 == input_rel_hdr->sh_entsize))
5252 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5253 rel_countp = &elf_section_data (output_section)->rel_count2;
5256 BFD_ASSERT (output_rel_hdr != NULL);
5258 irela = internal_relocs;
5259 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5260 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5262 Elf_External_Rel *erel;
5264 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5265 for (; irela < irelaend; irela++, erel++)
5267 Elf_Internal_Rel irel;
5269 irel.r_offset = irela->r_offset;
5270 irel.r_info = irela->r_info;
5271 BFD_ASSERT (irela->r_addend == 0);
5272 elf_swap_reloc_out (output_bfd, &irel, erel);
5275 else
5277 Elf_External_Rela *erela;
5279 BFD_ASSERT (input_rel_hdr->sh_entsize
5280 == sizeof (Elf_External_Rela));
5281 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5282 for (; irela < irelaend; irela++, erela++)
5283 elf_swap_reloca_out (output_bfd, irela, erela);
5286 /* Bump the counter, so that we know where to add the next set of
5287 relocations. */
5288 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5291 /* Link an input file into the linker output file. This function
5292 handles all the sections and relocations of the input file at once.
5293 This is so that we only have to read the local symbols once, and
5294 don't have to keep them in memory. */
5296 static boolean
5297 elf_link_input_bfd (finfo, input_bfd)
5298 struct elf_final_link_info *finfo;
5299 bfd *input_bfd;
5301 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5302 bfd *, asection *, bfd_byte *,
5303 Elf_Internal_Rela *,
5304 Elf_Internal_Sym *, asection **));
5305 bfd *output_bfd;
5306 Elf_Internal_Shdr *symtab_hdr;
5307 size_t locsymcount;
5308 size_t extsymoff;
5309 Elf_External_Sym *external_syms;
5310 Elf_External_Sym *esym;
5311 Elf_External_Sym *esymend;
5312 Elf_Internal_Sym *isym;
5313 long *pindex;
5314 asection **ppsection;
5315 asection *o;
5316 struct elf_backend_data *bed;
5318 output_bfd = finfo->output_bfd;
5319 bed = get_elf_backend_data (output_bfd);
5320 relocate_section = bed->elf_backend_relocate_section;
5322 /* If this is a dynamic object, we don't want to do anything here:
5323 we don't want the local symbols, and we don't want the section
5324 contents. */
5325 if ((input_bfd->flags & DYNAMIC) != 0)
5326 return true;
5328 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5329 if (elf_bad_symtab (input_bfd))
5331 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5332 extsymoff = 0;
5334 else
5336 locsymcount = symtab_hdr->sh_info;
5337 extsymoff = symtab_hdr->sh_info;
5340 /* Read the local symbols. */
5341 if (symtab_hdr->contents != NULL)
5342 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5343 else if (locsymcount == 0)
5344 external_syms = NULL;
5345 else
5347 external_syms = finfo->external_syms;
5348 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5349 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5350 locsymcount, input_bfd)
5351 != locsymcount * sizeof (Elf_External_Sym)))
5352 return false;
5355 /* Swap in the local symbols and write out the ones which we know
5356 are going into the output file. */
5357 esym = external_syms;
5358 esymend = esym + locsymcount;
5359 isym = finfo->internal_syms;
5360 pindex = finfo->indices;
5361 ppsection = finfo->sections;
5362 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5364 asection *isec;
5365 const char *name;
5366 Elf_Internal_Sym osym;
5368 elf_swap_symbol_in (input_bfd, esym, isym);
5369 *pindex = -1;
5371 if (elf_bad_symtab (input_bfd))
5373 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5375 *ppsection = NULL;
5376 continue;
5380 if (isym->st_shndx == SHN_UNDEF)
5381 isec = bfd_und_section_ptr;
5382 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5383 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5384 else if (isym->st_shndx == SHN_ABS)
5385 isec = bfd_abs_section_ptr;
5386 else if (isym->st_shndx == SHN_COMMON)
5387 isec = bfd_com_section_ptr;
5388 else
5390 /* Who knows? */
5391 isec = NULL;
5394 *ppsection = isec;
5396 /* Don't output the first, undefined, symbol. */
5397 if (esym == external_syms)
5398 continue;
5400 /* If we are stripping all symbols, we don't want to output this
5401 one. */
5402 if (finfo->info->strip == strip_all)
5403 continue;
5405 /* We never output section symbols. Instead, we use the section
5406 symbol of the corresponding section in the output file. */
5407 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5408 continue;
5410 /* If we are discarding all local symbols, we don't want to
5411 output this one. If we are generating a relocateable output
5412 file, then some of the local symbols may be required by
5413 relocs; we output them below as we discover that they are
5414 needed. */
5415 if (finfo->info->discard == discard_all)
5416 continue;
5418 /* If this symbol is defined in a section which we are
5419 discarding, we don't need to keep it, but note that
5420 linker_mark is only reliable for sections that have contents.
5421 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5422 as well as linker_mark. */
5423 if (isym->st_shndx > 0
5424 && isym->st_shndx < SHN_LORESERVE
5425 && isec != NULL
5426 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5427 || (! finfo->info->relocateable
5428 && (isec->flags & SEC_EXCLUDE) != 0)))
5429 continue;
5431 /* Get the name of the symbol. */
5432 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5433 isym->st_name);
5434 if (name == NULL)
5435 return false;
5437 /* See if we are discarding symbols with this name. */
5438 if ((finfo->info->strip == strip_some
5439 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5440 == NULL))
5441 || (finfo->info->discard == discard_l
5442 && bfd_is_local_label_name (input_bfd, name)))
5443 continue;
5445 /* If we get here, we are going to output this symbol. */
5447 osym = *isym;
5449 /* Adjust the section index for the output file. */
5450 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5451 isec->output_section);
5452 if (osym.st_shndx == (unsigned short) -1)
5453 return false;
5455 *pindex = bfd_get_symcount (output_bfd);
5457 /* ELF symbols in relocateable files are section relative, but
5458 in executable files they are virtual addresses. Note that
5459 this code assumes that all ELF sections have an associated
5460 BFD section with a reasonable value for output_offset; below
5461 we assume that they also have a reasonable value for
5462 output_section. Any special sections must be set up to meet
5463 these requirements. */
5464 osym.st_value += isec->output_offset;
5465 if (! finfo->info->relocateable)
5466 osym.st_value += isec->output_section->vma;
5468 if (! elf_link_output_sym (finfo, name, &osym, isec))
5469 return false;
5472 /* Relocate the contents of each section. */
5473 for (o = input_bfd->sections; o != NULL; o = o->next)
5475 bfd_byte *contents;
5477 if (! o->linker_mark)
5479 /* This section was omitted from the link. */
5480 continue;
5483 if ((o->flags & SEC_HAS_CONTENTS) == 0
5484 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5485 continue;
5487 if ((o->flags & SEC_LINKER_CREATED) != 0)
5489 /* Section was created by elf_link_create_dynamic_sections
5490 or somesuch. */
5491 continue;
5494 /* Get the contents of the section. They have been cached by a
5495 relaxation routine. Note that o is a section in an input
5496 file, so the contents field will not have been set by any of
5497 the routines which work on output files. */
5498 if (elf_section_data (o)->this_hdr.contents != NULL)
5499 contents = elf_section_data (o)->this_hdr.contents;
5500 else
5502 contents = finfo->contents;
5503 if (! bfd_get_section_contents (input_bfd, o, contents,
5504 (file_ptr) 0, o->_raw_size))
5505 return false;
5508 if ((o->flags & SEC_RELOC) != 0)
5510 Elf_Internal_Rela *internal_relocs;
5512 /* Get the swapped relocs. */
5513 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5514 (input_bfd, o, finfo->external_relocs,
5515 finfo->internal_relocs, false));
5516 if (internal_relocs == NULL
5517 && o->reloc_count > 0)
5518 return false;
5520 /* Relocate the section by invoking a back end routine.
5522 The back end routine is responsible for adjusting the
5523 section contents as necessary, and (if using Rela relocs
5524 and generating a relocateable output file) adjusting the
5525 reloc addend as necessary.
5527 The back end routine does not have to worry about setting
5528 the reloc address or the reloc symbol index.
5530 The back end routine is given a pointer to the swapped in
5531 internal symbols, and can access the hash table entries
5532 for the external symbols via elf_sym_hashes (input_bfd).
5534 When generating relocateable output, the back end routine
5535 must handle STB_LOCAL/STT_SECTION symbols specially. The
5536 output symbol is going to be a section symbol
5537 corresponding to the output section, which will require
5538 the addend to be adjusted. */
5540 if (! (*relocate_section) (output_bfd, finfo->info,
5541 input_bfd, o, contents,
5542 internal_relocs,
5543 finfo->internal_syms,
5544 finfo->sections))
5545 return false;
5547 if (finfo->info->relocateable)
5549 Elf_Internal_Rela *irela;
5550 Elf_Internal_Rela *irelaend;
5551 struct elf_link_hash_entry **rel_hash;
5552 Elf_Internal_Shdr *input_rel_hdr;
5554 /* Adjust the reloc addresses and symbol indices. */
5556 irela = internal_relocs;
5557 irelaend =
5558 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5559 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5560 + elf_section_data (o->output_section)->rel_count
5561 + elf_section_data (o->output_section)->rel_count2);
5562 for (; irela < irelaend; irela++, rel_hash++)
5564 unsigned long r_symndx;
5565 Elf_Internal_Sym *isym;
5566 asection *sec;
5568 irela->r_offset += o->output_offset;
5570 r_symndx = ELF_R_SYM (irela->r_info);
5572 if (r_symndx == 0)
5573 continue;
5575 if (r_symndx >= locsymcount
5576 || (elf_bad_symtab (input_bfd)
5577 && finfo->sections[r_symndx] == NULL))
5579 struct elf_link_hash_entry *rh;
5580 long indx;
5582 /* This is a reloc against a global symbol. We
5583 have not yet output all the local symbols, so
5584 we do not know the symbol index of any global
5585 symbol. We set the rel_hash entry for this
5586 reloc to point to the global hash table entry
5587 for this symbol. The symbol index is then
5588 set at the end of elf_bfd_final_link. */
5589 indx = r_symndx - extsymoff;
5590 rh = elf_sym_hashes (input_bfd)[indx];
5591 while (rh->root.type == bfd_link_hash_indirect
5592 || rh->root.type == bfd_link_hash_warning)
5593 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5595 /* Setting the index to -2 tells
5596 elf_link_output_extsym that this symbol is
5597 used by a reloc. */
5598 BFD_ASSERT (rh->indx < 0);
5599 rh->indx = -2;
5601 *rel_hash = rh;
5603 continue;
5606 /* This is a reloc against a local symbol. */
5608 *rel_hash = NULL;
5609 isym = finfo->internal_syms + r_symndx;
5610 sec = finfo->sections[r_symndx];
5611 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5613 /* I suppose the backend ought to fill in the
5614 section of any STT_SECTION symbol against a
5615 processor specific section. If we have
5616 discarded a section, the output_section will
5617 be the absolute section. */
5618 if (sec != NULL
5619 && (bfd_is_abs_section (sec)
5620 || (sec->output_section != NULL
5621 && bfd_is_abs_section (sec->output_section))))
5622 r_symndx = 0;
5623 else if (sec == NULL || sec->owner == NULL)
5625 bfd_set_error (bfd_error_bad_value);
5626 return false;
5628 else
5630 r_symndx = sec->output_section->target_index;
5631 BFD_ASSERT (r_symndx != 0);
5634 else
5636 if (finfo->indices[r_symndx] == -1)
5638 unsigned long link;
5639 const char *name;
5640 asection *osec;
5642 if (finfo->info->strip == strip_all)
5644 /* You can't do ld -r -s. */
5645 bfd_set_error (bfd_error_invalid_operation);
5646 return false;
5649 /* This symbol was skipped earlier, but
5650 since it is needed by a reloc, we
5651 must output it now. */
5652 link = symtab_hdr->sh_link;
5653 name = bfd_elf_string_from_elf_section (input_bfd,
5654 link,
5655 isym->st_name);
5656 if (name == NULL)
5657 return false;
5659 osec = sec->output_section;
5660 isym->st_shndx =
5661 _bfd_elf_section_from_bfd_section (output_bfd,
5662 osec);
5663 if (isym->st_shndx == (unsigned short) -1)
5664 return false;
5666 isym->st_value += sec->output_offset;
5667 if (! finfo->info->relocateable)
5668 isym->st_value += osec->vma;
5670 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5672 if (! elf_link_output_sym (finfo, name, isym, sec))
5673 return false;
5676 r_symndx = finfo->indices[r_symndx];
5679 irela->r_info = ELF_R_INFO (r_symndx,
5680 ELF_R_TYPE (irela->r_info));
5683 /* Swap out the relocs. */
5684 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5685 elf_link_output_relocs (output_bfd, o,
5686 input_rel_hdr,
5687 internal_relocs);
5688 internal_relocs
5689 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5690 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5691 if (input_rel_hdr)
5692 elf_link_output_relocs (output_bfd, o,
5693 input_rel_hdr,
5694 internal_relocs);
5698 /* Write out the modified section contents. */
5699 if (elf_section_data (o)->stab_info == NULL)
5701 if (! (o->flags & SEC_EXCLUDE) &&
5702 ! bfd_set_section_contents (output_bfd, o->output_section,
5703 contents, o->output_offset,
5704 (o->_cooked_size != 0
5705 ? o->_cooked_size
5706 : o->_raw_size)))
5707 return false;
5709 else
5711 if (! (_bfd_write_section_stabs
5712 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5713 o, &elf_section_data (o)->stab_info, contents)))
5714 return false;
5718 return true;
5721 /* Generate a reloc when linking an ELF file. This is a reloc
5722 requested by the linker, and does come from any input file. This
5723 is used to build constructor and destructor tables when linking
5724 with -Ur. */
5726 static boolean
5727 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5728 bfd *output_bfd;
5729 struct bfd_link_info *info;
5730 asection *output_section;
5731 struct bfd_link_order *link_order;
5733 reloc_howto_type *howto;
5734 long indx;
5735 bfd_vma offset;
5736 bfd_vma addend;
5737 struct elf_link_hash_entry **rel_hash_ptr;
5738 Elf_Internal_Shdr *rel_hdr;
5740 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5741 if (howto == NULL)
5743 bfd_set_error (bfd_error_bad_value);
5744 return false;
5747 addend = link_order->u.reloc.p->addend;
5749 /* Figure out the symbol index. */
5750 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5751 + elf_section_data (output_section)->rel_count
5752 + elf_section_data (output_section)->rel_count2);
5753 if (link_order->type == bfd_section_reloc_link_order)
5755 indx = link_order->u.reloc.p->u.section->target_index;
5756 BFD_ASSERT (indx != 0);
5757 *rel_hash_ptr = NULL;
5759 else
5761 struct elf_link_hash_entry *h;
5763 /* Treat a reloc against a defined symbol as though it were
5764 actually against the section. */
5765 h = ((struct elf_link_hash_entry *)
5766 bfd_wrapped_link_hash_lookup (output_bfd, info,
5767 link_order->u.reloc.p->u.name,
5768 false, false, true));
5769 if (h != NULL
5770 && (h->root.type == bfd_link_hash_defined
5771 || h->root.type == bfd_link_hash_defweak))
5773 asection *section;
5775 section = h->root.u.def.section;
5776 indx = section->output_section->target_index;
5777 *rel_hash_ptr = NULL;
5778 /* It seems that we ought to add the symbol value to the
5779 addend here, but in practice it has already been added
5780 because it was passed to constructor_callback. */
5781 addend += section->output_section->vma + section->output_offset;
5783 else if (h != NULL)
5785 /* Setting the index to -2 tells elf_link_output_extsym that
5786 this symbol is used by a reloc. */
5787 h->indx = -2;
5788 *rel_hash_ptr = h;
5789 indx = 0;
5791 else
5793 if (! ((*info->callbacks->unattached_reloc)
5794 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5795 (asection *) NULL, (bfd_vma) 0)))
5796 return false;
5797 indx = 0;
5801 /* If this is an inplace reloc, we must write the addend into the
5802 object file. */
5803 if (howto->partial_inplace && addend != 0)
5805 bfd_size_type size;
5806 bfd_reloc_status_type rstat;
5807 bfd_byte *buf;
5808 boolean ok;
5810 size = bfd_get_reloc_size (howto);
5811 buf = (bfd_byte *) bfd_zmalloc (size);
5812 if (buf == (bfd_byte *) NULL)
5813 return false;
5814 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5815 switch (rstat)
5817 case bfd_reloc_ok:
5818 break;
5819 default:
5820 case bfd_reloc_outofrange:
5821 abort ();
5822 case bfd_reloc_overflow:
5823 if (! ((*info->callbacks->reloc_overflow)
5824 (info,
5825 (link_order->type == bfd_section_reloc_link_order
5826 ? bfd_section_name (output_bfd,
5827 link_order->u.reloc.p->u.section)
5828 : link_order->u.reloc.p->u.name),
5829 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5830 (bfd_vma) 0)))
5832 free (buf);
5833 return false;
5835 break;
5837 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
5838 (file_ptr) link_order->offset, size);
5839 free (buf);
5840 if (! ok)
5841 return false;
5844 /* The address of a reloc is relative to the section in a
5845 relocateable file, and is a virtual address in an executable
5846 file. */
5847 offset = link_order->offset;
5848 if (! info->relocateable)
5849 offset += output_section->vma;
5851 rel_hdr = &elf_section_data (output_section)->rel_hdr;
5853 if (rel_hdr->sh_type == SHT_REL)
5855 Elf_Internal_Rel irel;
5856 Elf_External_Rel *erel;
5858 irel.r_offset = offset;
5859 irel.r_info = ELF_R_INFO (indx, howto->type);
5860 erel = ((Elf_External_Rel *) rel_hdr->contents
5861 + elf_section_data (output_section)->rel_count);
5862 elf_swap_reloc_out (output_bfd, &irel, erel);
5864 else
5866 Elf_Internal_Rela irela;
5867 Elf_External_Rela *erela;
5869 irela.r_offset = offset;
5870 irela.r_info = ELF_R_INFO (indx, howto->type);
5871 irela.r_addend = addend;
5872 erela = ((Elf_External_Rela *) rel_hdr->contents
5873 + elf_section_data (output_section)->rel_count);
5874 elf_swap_reloca_out (output_bfd, &irela, erela);
5877 ++elf_section_data (output_section)->rel_count;
5879 return true;
5883 /* Allocate a pointer to live in a linker created section. */
5885 boolean
5886 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
5887 bfd *abfd;
5888 struct bfd_link_info *info;
5889 elf_linker_section_t *lsect;
5890 struct elf_link_hash_entry *h;
5891 const Elf_Internal_Rela *rel;
5893 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
5894 elf_linker_section_pointers_t *linker_section_ptr;
5895 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
5897 BFD_ASSERT (lsect != NULL);
5899 /* Is this a global symbol? */
5900 if (h != NULL)
5902 /* Has this symbol already been allocated, if so, our work is done */
5903 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
5904 rel->r_addend,
5905 lsect->which))
5906 return true;
5908 ptr_linker_section_ptr = &h->linker_section_pointer;
5909 /* Make sure this symbol is output as a dynamic symbol. */
5910 if (h->dynindx == -1)
5912 if (! elf_link_record_dynamic_symbol (info, h))
5913 return false;
5916 if (lsect->rel_section)
5917 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5920 else /* Allocation of a pointer to a local symbol */
5922 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
5924 /* Allocate a table to hold the local symbols if first time */
5925 if (!ptr)
5927 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
5928 register unsigned int i;
5930 ptr = (elf_linker_section_pointers_t **)
5931 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
5933 if (!ptr)
5934 return false;
5936 elf_local_ptr_offsets (abfd) = ptr;
5937 for (i = 0; i < num_symbols; i++)
5938 ptr[i] = (elf_linker_section_pointers_t *)0;
5941 /* Has this symbol already been allocated, if so, our work is done */
5942 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
5943 rel->r_addend,
5944 lsect->which))
5945 return true;
5947 ptr_linker_section_ptr = &ptr[r_symndx];
5949 if (info->shared)
5951 /* If we are generating a shared object, we need to
5952 output a R_<xxx>_RELATIVE reloc so that the
5953 dynamic linker can adjust this GOT entry. */
5954 BFD_ASSERT (lsect->rel_section != NULL);
5955 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
5959 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
5960 from internal memory. */
5961 BFD_ASSERT (ptr_linker_section_ptr != NULL);
5962 linker_section_ptr = (elf_linker_section_pointers_t *)
5963 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
5965 if (!linker_section_ptr)
5966 return false;
5968 linker_section_ptr->next = *ptr_linker_section_ptr;
5969 linker_section_ptr->addend = rel->r_addend;
5970 linker_section_ptr->which = lsect->which;
5971 linker_section_ptr->written_address_p = false;
5972 *ptr_linker_section_ptr = linker_section_ptr;
5974 #if 0
5975 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
5977 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
5978 lsect->hole_offset += ARCH_SIZE / 8;
5979 lsect->sym_offset += ARCH_SIZE / 8;
5980 if (lsect->sym_hash) /* Bump up symbol value if needed */
5982 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
5983 #ifdef DEBUG
5984 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
5985 lsect->sym_hash->root.root.string,
5986 (long)ARCH_SIZE / 8,
5987 (long)lsect->sym_hash->root.u.def.value);
5988 #endif
5991 else
5992 #endif
5993 linker_section_ptr->offset = lsect->section->_raw_size;
5995 lsect->section->_raw_size += ARCH_SIZE / 8;
5997 #ifdef DEBUG
5998 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
5999 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
6000 #endif
6002 return true;
6006 #if ARCH_SIZE==64
6007 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
6008 #endif
6009 #if ARCH_SIZE==32
6010 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
6011 #endif
6013 /* Fill in the address for a pointer generated in alinker section. */
6015 bfd_vma
6016 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
6017 bfd *output_bfd;
6018 bfd *input_bfd;
6019 struct bfd_link_info *info;
6020 elf_linker_section_t *lsect;
6021 struct elf_link_hash_entry *h;
6022 bfd_vma relocation;
6023 const Elf_Internal_Rela *rel;
6024 int relative_reloc;
6026 elf_linker_section_pointers_t *linker_section_ptr;
6028 BFD_ASSERT (lsect != NULL);
6030 if (h != NULL) /* global symbol */
6032 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6033 rel->r_addend,
6034 lsect->which);
6036 BFD_ASSERT (linker_section_ptr != NULL);
6038 if (! elf_hash_table (info)->dynamic_sections_created
6039 || (info->shared
6040 && info->symbolic
6041 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
6043 /* This is actually a static link, or it is a
6044 -Bsymbolic link and the symbol is defined
6045 locally. We must initialize this entry in the
6046 global section.
6048 When doing a dynamic link, we create a .rela.<xxx>
6049 relocation entry to initialize the value. This
6050 is done in the finish_dynamic_symbol routine. */
6051 if (!linker_section_ptr->written_address_p)
6053 linker_section_ptr->written_address_p = true;
6054 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6055 lsect->section->contents + linker_section_ptr->offset);
6059 else /* local symbol */
6061 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6062 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6063 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6064 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6065 rel->r_addend,
6066 lsect->which);
6068 BFD_ASSERT (linker_section_ptr != NULL);
6070 /* Write out pointer if it hasn't been rewritten out before */
6071 if (!linker_section_ptr->written_address_p)
6073 linker_section_ptr->written_address_p = true;
6074 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6075 lsect->section->contents + linker_section_ptr->offset);
6077 if (info->shared)
6079 asection *srel = lsect->rel_section;
6080 Elf_Internal_Rela outrel;
6082 /* We need to generate a relative reloc for the dynamic linker. */
6083 if (!srel)
6084 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6085 lsect->rel_name);
6087 BFD_ASSERT (srel != NULL);
6089 outrel.r_offset = (lsect->section->output_section->vma
6090 + lsect->section->output_offset
6091 + linker_section_ptr->offset);
6092 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6093 outrel.r_addend = 0;
6094 elf_swap_reloca_out (output_bfd, &outrel,
6095 (((Elf_External_Rela *)
6096 lsect->section->contents)
6097 + elf_section_data (lsect->section)->rel_count));
6098 ++elf_section_data (lsect->section)->rel_count;
6103 relocation = (lsect->section->output_offset
6104 + linker_section_ptr->offset
6105 - lsect->hole_offset
6106 - lsect->sym_offset);
6108 #ifdef DEBUG
6109 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6110 lsect->name, (long)relocation, (long)relocation);
6111 #endif
6113 /* Subtract out the addend, because it will get added back in by the normal
6114 processing. */
6115 return relocation - linker_section_ptr->addend;
6118 /* Garbage collect unused sections. */
6120 static boolean elf_gc_mark
6121 PARAMS ((struct bfd_link_info *info, asection *sec,
6122 asection * (*gc_mark_hook)
6123 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6124 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6126 static boolean elf_gc_sweep
6127 PARAMS ((struct bfd_link_info *info,
6128 boolean (*gc_sweep_hook)
6129 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6130 const Elf_Internal_Rela *relocs))));
6132 static boolean elf_gc_sweep_symbol
6133 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6135 static boolean elf_gc_allocate_got_offsets
6136 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6138 static boolean elf_gc_propagate_vtable_entries_used
6139 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6141 static boolean elf_gc_smash_unused_vtentry_relocs
6142 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6144 /* The mark phase of garbage collection. For a given section, mark
6145 it, and all the sections which define symbols to which it refers. */
6147 static boolean
6148 elf_gc_mark (info, sec, gc_mark_hook)
6149 struct bfd_link_info *info;
6150 asection *sec;
6151 asection * (*gc_mark_hook)
6152 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6153 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6155 boolean ret = true;
6157 sec->gc_mark = 1;
6159 /* Look through the section relocs. */
6161 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6163 Elf_Internal_Rela *relstart, *rel, *relend;
6164 Elf_Internal_Shdr *symtab_hdr;
6165 struct elf_link_hash_entry **sym_hashes;
6166 size_t nlocsyms;
6167 size_t extsymoff;
6168 Elf_External_Sym *locsyms, *freesyms = NULL;
6169 bfd *input_bfd = sec->owner;
6170 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6172 /* GCFIXME: how to arrange so that relocs and symbols are not
6173 reread continually? */
6175 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6176 sym_hashes = elf_sym_hashes (input_bfd);
6178 /* Read the local symbols. */
6179 if (elf_bad_symtab (input_bfd))
6181 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6182 extsymoff = 0;
6184 else
6185 extsymoff = nlocsyms = symtab_hdr->sh_info;
6186 if (symtab_hdr->contents)
6187 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6188 else if (nlocsyms == 0)
6189 locsyms = NULL;
6190 else
6192 locsyms = freesyms =
6193 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6194 if (freesyms == NULL
6195 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6196 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6197 nlocsyms, input_bfd)
6198 != nlocsyms * sizeof (Elf_External_Sym)))
6200 ret = false;
6201 goto out1;
6205 /* Read the relocations. */
6206 relstart = (NAME(_bfd_elf,link_read_relocs)
6207 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6208 info->keep_memory));
6209 if (relstart == NULL)
6211 ret = false;
6212 goto out1;
6214 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6216 for (rel = relstart; rel < relend; rel++)
6218 unsigned long r_symndx;
6219 asection *rsec;
6220 struct elf_link_hash_entry *h;
6221 Elf_Internal_Sym s;
6223 r_symndx = ELF_R_SYM (rel->r_info);
6224 if (r_symndx == 0)
6225 continue;
6227 if (elf_bad_symtab (sec->owner))
6229 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6230 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6231 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6232 else
6234 h = sym_hashes[r_symndx - extsymoff];
6235 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6238 else if (r_symndx >= nlocsyms)
6240 h = sym_hashes[r_symndx - extsymoff];
6241 rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
6243 else
6245 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6246 rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
6249 if (rsec && !rsec->gc_mark)
6250 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6252 ret = false;
6253 goto out2;
6257 out2:
6258 if (!info->keep_memory)
6259 free (relstart);
6260 out1:
6261 if (freesyms)
6262 free (freesyms);
6265 return ret;
6268 /* The sweep phase of garbage collection. Remove all garbage sections. */
6270 static boolean
6271 elf_gc_sweep (info, gc_sweep_hook)
6272 struct bfd_link_info *info;
6273 boolean (*gc_sweep_hook)
6274 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6275 const Elf_Internal_Rela *relocs));
6277 bfd *sub;
6279 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6281 asection *o;
6283 for (o = sub->sections; o != NULL; o = o->next)
6285 /* Keep special sections. Keep .debug sections. */
6286 if ((o->flags & SEC_LINKER_CREATED)
6287 || (o->flags & SEC_DEBUGGING))
6288 o->gc_mark = 1;
6290 if (o->gc_mark)
6291 continue;
6293 /* Skip sweeping sections already excluded. */
6294 if (o->flags & SEC_EXCLUDE)
6295 continue;
6297 /* Since this is early in the link process, it is simple
6298 to remove a section from the output. */
6299 o->flags |= SEC_EXCLUDE;
6301 /* But we also have to update some of the relocation
6302 info we collected before. */
6303 if (gc_sweep_hook
6304 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6306 Elf_Internal_Rela *internal_relocs;
6307 boolean r;
6309 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6310 (o->owner, o, NULL, NULL, info->keep_memory));
6311 if (internal_relocs == NULL)
6312 return false;
6314 r = (*gc_sweep_hook)(o->owner, info, o, internal_relocs);
6316 if (!info->keep_memory)
6317 free (internal_relocs);
6319 if (!r)
6320 return false;
6325 /* Remove the symbols that were in the swept sections from the dynamic
6326 symbol table. GCFIXME: Anyone know how to get them out of the
6327 static symbol table as well? */
6329 int i = 0;
6331 elf_link_hash_traverse (elf_hash_table (info),
6332 elf_gc_sweep_symbol,
6333 (PTR) &i);
6335 elf_hash_table (info)->dynsymcount = i;
6338 return true;
6341 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6343 static boolean
6344 elf_gc_sweep_symbol (h, idxptr)
6345 struct elf_link_hash_entry *h;
6346 PTR idxptr;
6348 int *idx = (int *) idxptr;
6350 if (h->dynindx != -1
6351 && ((h->root.type != bfd_link_hash_defined
6352 && h->root.type != bfd_link_hash_defweak)
6353 || h->root.u.def.section->gc_mark))
6354 h->dynindx = (*idx)++;
6356 return true;
6359 /* Propogate collected vtable information. This is called through
6360 elf_link_hash_traverse. */
6362 static boolean
6363 elf_gc_propagate_vtable_entries_used (h, okp)
6364 struct elf_link_hash_entry *h;
6365 PTR okp;
6367 /* Those that are not vtables. */
6368 if (h->vtable_parent == NULL)
6369 return true;
6371 /* Those vtables that do not have parents, we cannot merge. */
6372 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6373 return true;
6375 /* If we've already been done, exit. */
6376 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6377 return true;
6379 /* Make sure the parent's table is up to date. */
6380 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6382 if (h->vtable_entries_used == NULL)
6384 /* None of this table's entries were referenced. Re-use the
6385 parent's table. */
6386 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6387 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6389 else
6391 size_t n;
6392 boolean *cu, *pu;
6394 /* Or the parent's entries into ours. */
6395 cu = h->vtable_entries_used;
6396 cu[-1] = true;
6397 pu = h->vtable_parent->vtable_entries_used;
6398 if (pu != NULL)
6400 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6401 while (--n != 0)
6403 if (*pu) *cu = true;
6404 pu++, cu++;
6409 return true;
6412 static boolean
6413 elf_gc_smash_unused_vtentry_relocs (h, okp)
6414 struct elf_link_hash_entry *h;
6415 PTR okp;
6417 asection *sec;
6418 bfd_vma hstart, hend;
6419 Elf_Internal_Rela *relstart, *relend, *rel;
6420 struct elf_backend_data *bed;
6422 /* Take care of both those symbols that do not describe vtables as
6423 well as those that are not loaded. */
6424 if (h->vtable_parent == NULL)
6425 return true;
6427 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6428 || h->root.type == bfd_link_hash_defweak);
6430 sec = h->root.u.def.section;
6431 hstart = h->root.u.def.value;
6432 hend = hstart + h->size;
6434 relstart = (NAME(_bfd_elf,link_read_relocs)
6435 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6436 if (!relstart)
6437 return *(boolean *)okp = false;
6438 bed = get_elf_backend_data (sec->owner);
6439 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6441 for (rel = relstart; rel < relend; ++rel)
6442 if (rel->r_offset >= hstart && rel->r_offset < hend)
6444 /* If the entry is in use, do nothing. */
6445 if (h->vtable_entries_used
6446 && (rel->r_offset - hstart) < h->vtable_entries_size)
6448 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6449 if (h->vtable_entries_used[entry])
6450 continue;
6452 /* Otherwise, kill it. */
6453 rel->r_offset = rel->r_info = rel->r_addend = 0;
6456 return true;
6459 /* Do mark and sweep of unused sections. */
6461 boolean
6462 elf_gc_sections (abfd, info)
6463 bfd *abfd;
6464 struct bfd_link_info *info;
6466 boolean ok = true;
6467 bfd *sub;
6468 asection * (*gc_mark_hook)
6469 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6470 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6472 if (!get_elf_backend_data (abfd)->can_gc_sections
6473 || info->relocateable
6474 || elf_hash_table (info)->dynamic_sections_created)
6475 return true;
6477 /* Apply transitive closure to the vtable entry usage info. */
6478 elf_link_hash_traverse (elf_hash_table (info),
6479 elf_gc_propagate_vtable_entries_used,
6480 (PTR) &ok);
6481 if (!ok)
6482 return false;
6484 /* Kill the vtable relocations that were not used. */
6485 elf_link_hash_traverse (elf_hash_table (info),
6486 elf_gc_smash_unused_vtentry_relocs,
6487 (PTR) &ok);
6488 if (!ok)
6489 return false;
6491 /* Grovel through relocs to find out who stays ... */
6493 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6494 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6496 asection *o;
6497 for (o = sub->sections; o != NULL; o = o->next)
6499 if (o->flags & SEC_KEEP)
6500 if (!elf_gc_mark (info, o, gc_mark_hook))
6501 return false;
6505 /* ... and mark SEC_EXCLUDE for those that go. */
6506 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6507 return false;
6509 return true;
6512 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6514 boolean
6515 elf_gc_record_vtinherit (abfd, sec, h, offset)
6516 bfd *abfd;
6517 asection *sec;
6518 struct elf_link_hash_entry *h;
6519 bfd_vma offset;
6521 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6522 struct elf_link_hash_entry **search, *child;
6523 bfd_size_type extsymcount;
6525 /* The sh_info field of the symtab header tells us where the
6526 external symbols start. We don't care about the local symbols at
6527 this point. */
6528 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6529 if (!elf_bad_symtab (abfd))
6530 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6532 sym_hashes = elf_sym_hashes (abfd);
6533 sym_hashes_end = sym_hashes + extsymcount;
6535 /* Hunt down the child symbol, which is in this section at the same
6536 offset as the relocation. */
6537 for (search = sym_hashes; search != sym_hashes_end; ++search)
6539 if ((child = *search) != NULL
6540 && (child->root.type == bfd_link_hash_defined
6541 || child->root.type == bfd_link_hash_defweak)
6542 && child->root.u.def.section == sec
6543 && child->root.u.def.value == offset)
6544 goto win;
6547 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6548 bfd_get_filename (abfd), sec->name,
6549 (unsigned long)offset);
6550 bfd_set_error (bfd_error_invalid_operation);
6551 return false;
6553 win:
6554 if (!h)
6556 /* This *should* only be the absolute section. It could potentially
6557 be that someone has defined a non-global vtable though, which
6558 would be bad. It isn't worth paging in the local symbols to be
6559 sure though; that case should simply be handled by the assembler. */
6561 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6563 else
6564 child->vtable_parent = h;
6566 return true;
6569 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6571 boolean
6572 elf_gc_record_vtentry (abfd, sec, h, addend)
6573 bfd *abfd ATTRIBUTE_UNUSED;
6574 asection *sec ATTRIBUTE_UNUSED;
6575 struct elf_link_hash_entry *h;
6576 bfd_vma addend;
6578 if (addend >= h->vtable_entries_size)
6580 size_t size, bytes;
6581 boolean *ptr = h->vtable_entries_used;
6583 /* While the symbol is undefined, we have to be prepared to handle
6584 a zero size. */
6585 if (h->root.type == bfd_link_hash_undefined)
6586 size = addend;
6587 else
6589 size = h->size;
6590 if (size < addend)
6592 /* Oops! We've got a reference past the defined end of
6593 the table. This is probably a bug -- shall we warn? */
6594 size = addend;
6598 /* Allocate one extra entry for use as a "done" flag for the
6599 consolidation pass. */
6600 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6602 if (ptr)
6604 ptr = bfd_realloc (ptr - 1, bytes);
6606 if (ptr != NULL)
6608 size_t oldbytes;
6610 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6611 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6614 else
6615 ptr = bfd_zmalloc (bytes);
6617 if (ptr == NULL)
6618 return false;
6620 /* And arrange for that done flag to be at index -1. */
6621 h->vtable_entries_used = ptr + 1;
6622 h->vtable_entries_size = size;
6625 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6627 return true;
6630 /* And an accompanying bit to work out final got entry offsets once
6631 we're done. Should be called from final_link. */
6633 boolean
6634 elf_gc_common_finalize_got_offsets (abfd, info)
6635 bfd *abfd;
6636 struct bfd_link_info *info;
6638 bfd *i;
6639 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6640 bfd_vma gotoff;
6642 /* The GOT offset is relative to the .got section, but the GOT header is
6643 put into the .got.plt section, if the backend uses it. */
6644 if (bed->want_got_plt)
6645 gotoff = 0;
6646 else
6647 gotoff = bed->got_header_size;
6649 /* Do the local .got entries first. */
6650 for (i = info->input_bfds; i; i = i->link_next)
6652 bfd_signed_vma *local_got = elf_local_got_refcounts (i);
6653 bfd_size_type j, locsymcount;
6654 Elf_Internal_Shdr *symtab_hdr;
6656 if (!local_got)
6657 continue;
6659 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6660 if (elf_bad_symtab (i))
6661 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6662 else
6663 locsymcount = symtab_hdr->sh_info;
6665 for (j = 0; j < locsymcount; ++j)
6667 if (local_got[j] > 0)
6669 local_got[j] = gotoff;
6670 gotoff += ARCH_SIZE / 8;
6672 else
6673 local_got[j] = (bfd_vma) -1;
6677 /* Then the global .got and .plt entries. */
6678 elf_link_hash_traverse (elf_hash_table (info),
6679 elf_gc_allocate_got_offsets,
6680 (PTR) &gotoff);
6681 return true;
6684 /* We need a special top-level link routine to convert got reference counts
6685 to real got offsets. */
6687 static boolean
6688 elf_gc_allocate_got_offsets (h, offarg)
6689 struct elf_link_hash_entry *h;
6690 PTR offarg;
6692 bfd_vma *off = (bfd_vma *) offarg;
6694 if (h->got.refcount > 0)
6696 h->got.offset = off[0];
6697 off[0] += ARCH_SIZE / 8;
6699 else
6700 h->got.offset = (bfd_vma) -1;
6702 return true;
6705 /* Many folk need no more in the way of final link than this, once
6706 got entry reference counting is enabled. */
6708 boolean
6709 elf_gc_common_final_link (abfd, info)
6710 bfd *abfd;
6711 struct bfd_link_info *info;
6713 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6714 return false;
6716 /* Invoke the regular ELF backend linker to do all the work. */
6717 return elf_bfd_final_link (abfd, info);
6720 /* This function will be called though elf_link_hash_traverse to store
6721 all hash value of the exported symbols in an array. */
6723 static boolean
6724 elf_collect_hash_codes (h, data)
6725 struct elf_link_hash_entry *h;
6726 PTR data;
6728 unsigned long **valuep = (unsigned long **) data;
6729 const char *name;
6730 char *p;
6731 unsigned long ha;
6732 char *alc = NULL;
6734 /* Ignore indirect symbols. These are added by the versioning code. */
6735 if (h->dynindx == -1)
6736 return true;
6738 name = h->root.root.string;
6739 p = strchr (name, ELF_VER_CHR);
6740 if (p != NULL)
6742 alc = bfd_malloc (p - name + 1);
6743 memcpy (alc, name, p - name);
6744 alc[p - name] = '\0';
6745 name = alc;
6748 /* Compute the hash value. */
6749 ha = bfd_elf_hash (name);
6751 /* Store the found hash value in the array given as the argument. */
6752 *(*valuep)++ = ha;
6754 /* And store it in the struct so that we can put it in the hash table
6755 later. */
6756 h->elf_hash_value = ha;
6758 if (alc != NULL)
6759 free (alc);
6761 return true;