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[binutils.git] / bfd / elflink.h
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1 /* ELF linker support.
2 Copyright 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20 /* ELF linker code. */
22 /* This struct is used to pass information to routines called via
23 elf_link_hash_traverse which must return failure. */
25 struct elf_info_failed
27 boolean failed;
28 struct bfd_link_info *info;
31 static boolean elf_link_add_object_symbols
32 PARAMS ((bfd *, struct bfd_link_info *));
33 static boolean elf_link_add_archive_symbols
34 PARAMS ((bfd *, struct bfd_link_info *));
35 static boolean elf_merge_symbol
36 PARAMS ((bfd *, struct bfd_link_info *, const char *, Elf_Internal_Sym *,
37 asection **, bfd_vma *, struct elf_link_hash_entry **,
38 boolean *, boolean *, boolean *, boolean));
39 static boolean elf_export_symbol
40 PARAMS ((struct elf_link_hash_entry *, PTR));
41 static boolean elf_fix_symbol_flags
42 PARAMS ((struct elf_link_hash_entry *, struct elf_info_failed *));
43 static boolean elf_adjust_dynamic_symbol
44 PARAMS ((struct elf_link_hash_entry *, PTR));
45 static boolean elf_link_find_version_dependencies
46 PARAMS ((struct elf_link_hash_entry *, PTR));
47 static boolean elf_link_find_version_dependencies
48 PARAMS ((struct elf_link_hash_entry *, PTR));
49 static boolean elf_link_assign_sym_version
50 PARAMS ((struct elf_link_hash_entry *, PTR));
51 static boolean elf_collect_hash_codes
52 PARAMS ((struct elf_link_hash_entry *, PTR));
53 static boolean elf_link_read_relocs_from_section
54 PARAMS ((bfd *, Elf_Internal_Shdr *, PTR, Elf_Internal_Rela *));
55 static void elf_link_output_relocs
56 PARAMS ((bfd *, asection *, Elf_Internal_Shdr *, Elf_Internal_Rela *));
57 static boolean elf_link_size_reloc_section
58 PARAMS ((bfd *, Elf_Internal_Shdr *, asection *));
59 static void elf_link_adjust_relocs
60 PARAMS ((bfd *, Elf_Internal_Shdr *, unsigned int,
61 struct elf_link_hash_entry **));
63 /* Given an ELF BFD, add symbols to the global hash table as
64 appropriate. */
66 boolean
67 elf_bfd_link_add_symbols (abfd, info)
68 bfd *abfd;
69 struct bfd_link_info *info;
71 switch (bfd_get_format (abfd))
73 case bfd_object:
74 return elf_link_add_object_symbols (abfd, info);
75 case bfd_archive:
76 return elf_link_add_archive_symbols (abfd, info);
77 default:
78 bfd_set_error (bfd_error_wrong_format);
79 return false;
83 /* Return true iff this is a non-common definition of a symbol. */
84 static boolean
85 is_global_symbol_definition (abfd, sym)
86 bfd * abfd ATTRIBUTE_UNUSED;
87 Elf_Internal_Sym * sym;
89 /* Local symbols do not count, but target specific ones might. */
90 if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
91 && ELF_ST_BIND (sym->st_info) < STB_LOOS)
92 return false;
94 /* If the section is undefined, then so is the symbol. */
95 if (sym->st_shndx == SHN_UNDEF)
96 return false;
98 /* If the symbol is defined in the common section, then
99 it is a common definition and so does not count. */
100 if (sym->st_shndx == SHN_COMMON)
101 return false;
103 /* If the symbol is in a target specific section then we
104 must rely upon the backend to tell us what it is. */
105 if (sym->st_shndx >= SHN_LORESERVE && sym->st_shndx < SHN_ABS)
106 /* FIXME - this function is not coded yet:
108 return _bfd_is_global_symbol_definition (abfd, sym);
110 Instead for now assume that the definition is not global,
111 Even if this is wrong, at least the linker will behave
112 in the same way that it used to do. */
113 return false;
115 return true;
118 /* Search the symbol table of the archive element of the archive ABFD
119 whoes archove map contains a mention of SYMDEF, and determine if
120 the symbol is defined in this element. */
121 static boolean
122 elf_link_is_defined_archive_symbol (abfd, symdef)
123 bfd * abfd;
124 carsym * symdef;
126 Elf_Internal_Shdr * hdr;
127 Elf_External_Sym * esym;
128 Elf_External_Sym * esymend;
129 Elf_External_Sym * buf = NULL;
130 size_t symcount;
131 size_t extsymcount;
132 size_t extsymoff;
133 boolean result = false;
135 abfd = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
136 if (abfd == (bfd *) NULL)
137 return false;
139 if (! bfd_check_format (abfd, bfd_object))
140 return false;
142 /* If we have already included the element containing this symbol in the
143 link then we do not need to include it again. Just claim that any symbol
144 it contains is not a definition, so that our caller will not decide to
145 (re)include this element. */
146 if (abfd->archive_pass)
147 return false;
149 /* Select the appropriate symbol table. */
150 if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
151 hdr = &elf_tdata (abfd)->symtab_hdr;
152 else
153 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
155 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
157 /* The sh_info field of the symtab header tells us where the
158 external symbols start. We don't care about the local symbols. */
159 if (elf_bad_symtab (abfd))
161 extsymcount = symcount;
162 extsymoff = 0;
164 else
166 extsymcount = symcount - hdr->sh_info;
167 extsymoff = hdr->sh_info;
170 buf = ((Elf_External_Sym *)
171 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
172 if (buf == NULL && extsymcount != 0)
173 return false;
175 /* Read in the symbol table.
176 FIXME: This ought to be cached somewhere. */
177 if (bfd_seek (abfd,
178 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
179 SEEK_SET) != 0
180 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
181 != extsymcount * sizeof (Elf_External_Sym)))
183 free (buf);
184 return false;
187 /* Scan the symbol table looking for SYMDEF. */
188 esymend = buf + extsymcount;
189 for (esym = buf;
190 esym < esymend;
191 esym++)
193 Elf_Internal_Sym sym;
194 const char * name;
196 elf_swap_symbol_in (abfd, esym, & sym);
198 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
199 if (name == (const char *) NULL)
200 break;
202 if (strcmp (name, symdef->name) == 0)
204 result = is_global_symbol_definition (abfd, & sym);
205 break;
209 free (buf);
211 return result;
215 /* Add symbols from an ELF archive file to the linker hash table. We
216 don't use _bfd_generic_link_add_archive_symbols because of a
217 problem which arises on UnixWare. The UnixWare libc.so is an
218 archive which includes an entry libc.so.1 which defines a bunch of
219 symbols. The libc.so archive also includes a number of other
220 object files, which also define symbols, some of which are the same
221 as those defined in libc.so.1. Correct linking requires that we
222 consider each object file in turn, and include it if it defines any
223 symbols we need. _bfd_generic_link_add_archive_symbols does not do
224 this; it looks through the list of undefined symbols, and includes
225 any object file which defines them. When this algorithm is used on
226 UnixWare, it winds up pulling in libc.so.1 early and defining a
227 bunch of symbols. This means that some of the other objects in the
228 archive are not included in the link, which is incorrect since they
229 precede libc.so.1 in the archive.
231 Fortunately, ELF archive handling is simpler than that done by
232 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
233 oddities. In ELF, if we find a symbol in the archive map, and the
234 symbol is currently undefined, we know that we must pull in that
235 object file.
237 Unfortunately, we do have to make multiple passes over the symbol
238 table until nothing further is resolved. */
240 static boolean
241 elf_link_add_archive_symbols (abfd, info)
242 bfd *abfd;
243 struct bfd_link_info *info;
245 symindex c;
246 boolean *defined = NULL;
247 boolean *included = NULL;
248 carsym *symdefs;
249 boolean loop;
251 if (! bfd_has_map (abfd))
253 /* An empty archive is a special case. */
254 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
255 return true;
256 bfd_set_error (bfd_error_no_armap);
257 return false;
260 /* Keep track of all symbols we know to be already defined, and all
261 files we know to be already included. This is to speed up the
262 second and subsequent passes. */
263 c = bfd_ardata (abfd)->symdef_count;
264 if (c == 0)
265 return true;
266 defined = (boolean *) bfd_malloc (c * sizeof (boolean));
267 included = (boolean *) bfd_malloc (c * sizeof (boolean));
268 if (defined == (boolean *) NULL || included == (boolean *) NULL)
269 goto error_return;
270 memset (defined, 0, c * sizeof (boolean));
271 memset (included, 0, c * sizeof (boolean));
273 symdefs = bfd_ardata (abfd)->symdefs;
277 file_ptr last;
278 symindex i;
279 carsym *symdef;
280 carsym *symdefend;
282 loop = false;
283 last = -1;
285 symdef = symdefs;
286 symdefend = symdef + c;
287 for (i = 0; symdef < symdefend; symdef++, i++)
289 struct elf_link_hash_entry *h;
290 bfd *element;
291 struct bfd_link_hash_entry *undefs_tail;
292 symindex mark;
294 if (defined[i] || included[i])
295 continue;
296 if (symdef->file_offset == last)
298 included[i] = true;
299 continue;
302 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
303 false, false, false);
305 if (h == NULL)
307 char *p, *copy;
309 /* If this is a default version (the name contains @@),
310 look up the symbol again without the version. The
311 effect is that references to the symbol without the
312 version will be matched by the default symbol in the
313 archive. */
315 p = strchr (symdef->name, ELF_VER_CHR);
316 if (p == NULL || p[1] != ELF_VER_CHR)
317 continue;
319 copy = bfd_alloc (abfd, p - symdef->name + 1);
320 if (copy == NULL)
321 goto error_return;
322 memcpy (copy, symdef->name, p - symdef->name);
323 copy[p - symdef->name] = '\0';
325 h = elf_link_hash_lookup (elf_hash_table (info), copy,
326 false, false, false);
328 bfd_release (abfd, copy);
331 if (h == NULL)
332 continue;
334 if (h->root.type == bfd_link_hash_common)
336 /* We currently have a common symbol. The archive map contains
337 a reference to this symbol, so we may want to include it. We
338 only want to include it however, if this archive element
339 contains a definition of the symbol, not just another common
340 declaration of it.
342 Unfortunately some archivers (including GNU ar) will put
343 declarations of common symbols into their archive maps, as
344 well as real definitions, so we cannot just go by the archive
345 map alone. Instead we must read in the element's symbol
346 table and check that to see what kind of symbol definition
347 this is. */
348 if (! elf_link_is_defined_archive_symbol (abfd, symdef))
349 continue;
351 else if (h->root.type != bfd_link_hash_undefined)
353 if (h->root.type != bfd_link_hash_undefweak)
354 defined[i] = true;
355 continue;
358 /* We need to include this archive member. */
359 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
360 if (element == (bfd *) NULL)
361 goto error_return;
363 if (! bfd_check_format (element, bfd_object))
364 goto error_return;
366 /* Doublecheck that we have not included this object
367 already--it should be impossible, but there may be
368 something wrong with the archive. */
369 if (element->archive_pass != 0)
371 bfd_set_error (bfd_error_bad_value);
372 goto error_return;
374 element->archive_pass = 1;
376 undefs_tail = info->hash->undefs_tail;
378 if (! (*info->callbacks->add_archive_element) (info, element,
379 symdef->name))
380 goto error_return;
381 if (! elf_link_add_object_symbols (element, info))
382 goto error_return;
384 /* If there are any new undefined symbols, we need to make
385 another pass through the archive in order to see whether
386 they can be defined. FIXME: This isn't perfect, because
387 common symbols wind up on undefs_tail and because an
388 undefined symbol which is defined later on in this pass
389 does not require another pass. This isn't a bug, but it
390 does make the code less efficient than it could be. */
391 if (undefs_tail != info->hash->undefs_tail)
392 loop = true;
394 /* Look backward to mark all symbols from this object file
395 which we have already seen in this pass. */
396 mark = i;
399 included[mark] = true;
400 if (mark == 0)
401 break;
402 --mark;
404 while (symdefs[mark].file_offset == symdef->file_offset);
406 /* We mark subsequent symbols from this object file as we go
407 on through the loop. */
408 last = symdef->file_offset;
411 while (loop);
413 free (defined);
414 free (included);
416 return true;
418 error_return:
419 if (defined != (boolean *) NULL)
420 free (defined);
421 if (included != (boolean *) NULL)
422 free (included);
423 return false;
426 /* This function is called when we want to define a new symbol. It
427 handles the various cases which arise when we find a definition in
428 a dynamic object, or when there is already a definition in a
429 dynamic object. The new symbol is described by NAME, SYM, PSEC,
430 and PVALUE. We set SYM_HASH to the hash table entry. We set
431 OVERRIDE if the old symbol is overriding a new definition. We set
432 TYPE_CHANGE_OK if it is OK for the type to change. We set
433 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
434 change, we mean that we shouldn't warn if the type or size does
435 change. DT_NEEDED indicates if it comes from a DT_NEEDED entry of
436 a shared object. */
438 static boolean
439 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
440 override, type_change_ok, size_change_ok, dt_needed)
441 bfd *abfd;
442 struct bfd_link_info *info;
443 const char *name;
444 Elf_Internal_Sym *sym;
445 asection **psec;
446 bfd_vma *pvalue;
447 struct elf_link_hash_entry **sym_hash;
448 boolean *override;
449 boolean *type_change_ok;
450 boolean *size_change_ok;
451 boolean dt_needed;
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 unless it comes from a DT_NEEDED entry of
629 a shared object, in which case, the DT_NEEDED entry may not be
630 required at the run time. */
632 if ((! dt_needed && h->root.type == bfd_link_hash_defweak)
633 || h->root.type == bfd_link_hash_undefweak
634 || bind == STB_WEAK)
635 *type_change_ok = true;
637 /* It's OK to change the size if either the existing symbol or the
638 new symbol is weak, or if the old symbol is undefined. */
640 if (*type_change_ok
641 || h->root.type == bfd_link_hash_undefined)
642 *size_change_ok = true;
644 /* If both the old and the new symbols look like common symbols in a
645 dynamic object, set the size of the symbol to the larger of the
646 two. */
648 if (olddyncommon
649 && newdyncommon
650 && sym->st_size != h->size)
652 /* Since we think we have two common symbols, issue a multiple
653 common warning if desired. Note that we only warn if the
654 size is different. If the size is the same, we simply let
655 the old symbol override the new one as normally happens with
656 symbols defined in dynamic objects. */
658 if (! ((*info->callbacks->multiple_common)
659 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
660 h->size, abfd, bfd_link_hash_common, sym->st_size)))
661 return false;
663 if (sym->st_size > h->size)
664 h->size = sym->st_size;
666 *size_change_ok = true;
669 /* If we are looking at a dynamic object, and we have found a
670 definition, we need to see if the symbol was already defined by
671 some other object. If so, we want to use the existing
672 definition, and we do not want to report a multiple symbol
673 definition error; we do this by clobbering *PSEC to be
674 bfd_und_section_ptr.
676 We treat a common symbol as a definition if the symbol in the
677 shared library is a function, since common symbols always
678 represent variables; this can cause confusion in principle, but
679 any such confusion would seem to indicate an erroneous program or
680 shared library. We also permit a common symbol in a regular
681 object to override a weak symbol in a shared object.
683 We prefer a non-weak definition in a shared library to a weak
684 definition in the executable unless it comes from a DT_NEEDED
685 entry of a shared object, in which case, the DT_NEEDED entry
686 may not be required at the run time. */
688 if (newdyn
689 && newdef
690 && (olddef
691 || (h->root.type == bfd_link_hash_common
692 && (bind == STB_WEAK
693 || ELF_ST_TYPE (sym->st_info) == STT_FUNC)))
694 && (h->root.type != bfd_link_hash_defweak
695 || dt_needed
696 || bind == STB_WEAK))
698 *override = true;
699 newdef = false;
700 newdyncommon = false;
702 *psec = sec = bfd_und_section_ptr;
703 *size_change_ok = true;
705 /* If we get here when the old symbol is a common symbol, then
706 we are explicitly letting it override a weak symbol or
707 function in a dynamic object, and we don't want to warn about
708 a type change. If the old symbol is a defined symbol, a type
709 change warning may still be appropriate. */
711 if (h->root.type == bfd_link_hash_common)
712 *type_change_ok = true;
715 /* Handle the special case of an old common symbol merging with a
716 new symbol which looks like a common symbol in a shared object.
717 We change *PSEC and *PVALUE to make the new symbol look like a
718 common symbol, and let _bfd_generic_link_add_one_symbol will do
719 the right thing. */
721 if (newdyncommon
722 && h->root.type == bfd_link_hash_common)
724 *override = true;
725 newdef = false;
726 newdyncommon = false;
727 *pvalue = sym->st_size;
728 *psec = sec = bfd_com_section_ptr;
729 *size_change_ok = true;
732 /* If the old symbol is from a dynamic object, and the new symbol is
733 a definition which is not from a dynamic object, then the new
734 symbol overrides the old symbol. Symbols from regular files
735 always take precedence over symbols from dynamic objects, even if
736 they are defined after the dynamic object in the link.
738 As above, we again permit a common symbol in a regular object to
739 override a definition in a shared object if the shared object
740 symbol is a function or is weak.
742 As above, we permit a non-weak definition in a shared object to
743 override a weak definition in a regular object. */
745 if (! newdyn
746 && (newdef
747 || (bfd_is_com_section (sec)
748 && (h->root.type == bfd_link_hash_defweak
749 || h->type == STT_FUNC)))
750 && olddyn
751 && olddef
752 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
753 && (bind != STB_WEAK
754 || h->root.type == bfd_link_hash_defweak))
756 /* Change the hash table entry to undefined, and let
757 _bfd_generic_link_add_one_symbol do the right thing with the
758 new definition. */
760 h->root.type = bfd_link_hash_undefined;
761 h->root.u.undef.abfd = h->root.u.def.section->owner;
762 *size_change_ok = true;
764 olddef = false;
765 olddyncommon = false;
767 /* We again permit a type change when a common symbol may be
768 overriding a function. */
770 if (bfd_is_com_section (sec))
771 *type_change_ok = true;
773 /* This union may have been set to be non-NULL when this symbol
774 was seen in a dynamic object. We must force the union to be
775 NULL, so that it is correct for a regular symbol. */
777 h->verinfo.vertree = NULL;
779 /* In this special case, if H is the target of an indirection,
780 we want the caller to frob with H rather than with the
781 indirect symbol. That will permit the caller to redefine the
782 target of the indirection, rather than the indirect symbol
783 itself. FIXME: This will break the -y option if we store a
784 symbol with a different name. */
785 *sym_hash = h;
788 /* Handle the special case of a new common symbol merging with an
789 old symbol that looks like it might be a common symbol defined in
790 a shared object. Note that we have already handled the case in
791 which a new common symbol should simply override the definition
792 in the shared library. */
794 if (! newdyn
795 && bfd_is_com_section (sec)
796 && olddyncommon)
798 /* It would be best if we could set the hash table entry to a
799 common symbol, but we don't know what to use for the section
800 or the alignment. */
801 if (! ((*info->callbacks->multiple_common)
802 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
803 h->size, abfd, bfd_link_hash_common, sym->st_size)))
804 return false;
806 /* If the predumed common symbol in the dynamic object is
807 larger, pretend that the new symbol has its size. */
809 if (h->size > *pvalue)
810 *pvalue = h->size;
812 /* FIXME: We no longer know the alignment required by the symbol
813 in the dynamic object, so we just wind up using the one from
814 the regular object. */
816 olddef = false;
817 olddyncommon = false;
819 h->root.type = bfd_link_hash_undefined;
820 h->root.u.undef.abfd = h->root.u.def.section->owner;
822 *size_change_ok = true;
823 *type_change_ok = true;
825 h->verinfo.vertree = NULL;
828 /* Handle the special case of a weak definition in a regular object
829 followed by a non-weak definition in a shared object. In this
830 case, we prefer the definition in the shared object unless it
831 comes from a DT_NEEDED entry of a shared object, in which case,
832 the DT_NEEDED entry may not be required at the run time. */
833 if (olddef
834 && ! dt_needed
835 && h->root.type == bfd_link_hash_defweak
836 && newdef
837 && newdyn
838 && bind != STB_WEAK)
840 /* To make this work we have to frob the flags so that the rest
841 of the code does not think we are using the regular
842 definition. */
843 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
844 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
845 else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
846 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
847 h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR
848 | ELF_LINK_HASH_DEF_DYNAMIC);
850 /* If H is the target of an indirection, we want the caller to
851 use H rather than the indirect symbol. Otherwise if we are
852 defining a new indirect symbol we will wind up attaching it
853 to the entry we are overriding. */
854 *sym_hash = h;
857 /* Handle the special case of a non-weak definition in a shared
858 object followed by a weak definition in a regular object. In
859 this case we prefer to definition in the shared object. To make
860 this work we have to tell the caller to not treat the new symbol
861 as a definition. */
862 if (olddef
863 && olddyn
864 && h->root.type != bfd_link_hash_defweak
865 && newdef
866 && ! newdyn
867 && bind == STB_WEAK)
868 *override = true;
870 return true;
873 /* Add symbols from an ELF object file to the linker hash table. */
875 static boolean
876 elf_link_add_object_symbols (abfd, info)
877 bfd *abfd;
878 struct bfd_link_info *info;
880 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
881 const Elf_Internal_Sym *,
882 const char **, flagword *,
883 asection **, bfd_vma *));
884 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
885 asection *, const Elf_Internal_Rela *));
886 boolean collect;
887 Elf_Internal_Shdr *hdr;
888 size_t symcount;
889 size_t extsymcount;
890 size_t extsymoff;
891 Elf_External_Sym *buf = NULL;
892 struct elf_link_hash_entry **sym_hash;
893 boolean dynamic;
894 bfd_byte *dynver = NULL;
895 Elf_External_Versym *extversym = NULL;
896 Elf_External_Versym *ever;
897 Elf_External_Dyn *dynbuf = NULL;
898 struct elf_link_hash_entry *weaks;
899 Elf_External_Sym *esym;
900 Elf_External_Sym *esymend;
901 struct elf_backend_data *bed;
902 boolean dt_needed;
904 bed = get_elf_backend_data (abfd);
905 add_symbol_hook = bed->elf_add_symbol_hook;
906 collect = bed->collect;
908 if ((abfd->flags & DYNAMIC) == 0)
909 dynamic = false;
910 else
912 dynamic = true;
914 /* You can't use -r against a dynamic object. Also, there's no
915 hope of using a dynamic object which does not exactly match
916 the format of the output file. */
917 if (info->relocateable || info->hash->creator != abfd->xvec)
919 bfd_set_error (bfd_error_invalid_operation);
920 goto error_return;
924 /* As a GNU extension, any input sections which are named
925 .gnu.warning.SYMBOL are treated as warning symbols for the given
926 symbol. This differs from .gnu.warning sections, which generate
927 warnings when they are included in an output file. */
928 if (! info->shared)
930 asection *s;
932 for (s = abfd->sections; s != NULL; s = s->next)
934 const char *name;
936 name = bfd_get_section_name (abfd, s);
937 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
939 char *msg;
940 bfd_size_type sz;
942 name += sizeof ".gnu.warning." - 1;
944 /* If this is a shared object, then look up the symbol
945 in the hash table. If it is there, and it is already
946 been defined, then we will not be using the entry
947 from this shared object, so we don't need to warn.
948 FIXME: If we see the definition in a regular object
949 later on, we will warn, but we shouldn't. The only
950 fix is to keep track of what warnings we are supposed
951 to emit, and then handle them all at the end of the
952 link. */
953 if (dynamic && abfd->xvec == info->hash->creator)
955 struct elf_link_hash_entry *h;
957 h = elf_link_hash_lookup (elf_hash_table (info), name,
958 false, false, true);
960 /* FIXME: What about bfd_link_hash_common? */
961 if (h != NULL
962 && (h->root.type == bfd_link_hash_defined
963 || h->root.type == bfd_link_hash_defweak))
965 /* We don't want to issue this warning. Clobber
966 the section size so that the warning does not
967 get copied into the output file. */
968 s->_raw_size = 0;
969 continue;
973 sz = bfd_section_size (abfd, s);
974 msg = (char *) bfd_alloc (abfd, sz + 1);
975 if (msg == NULL)
976 goto error_return;
978 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
979 goto error_return;
981 msg[sz] = '\0';
983 if (! (_bfd_generic_link_add_one_symbol
984 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
985 false, collect, (struct bfd_link_hash_entry **) NULL)))
986 goto error_return;
988 if (! info->relocateable)
990 /* Clobber the section size so that the warning does
991 not get copied into the output file. */
992 s->_raw_size = 0;
998 /* If this is a dynamic object, we always link against the .dynsym
999 symbol table, not the .symtab symbol table. The dynamic linker
1000 will only see the .dynsym symbol table, so there is no reason to
1001 look at .symtab for a dynamic object. */
1003 if (! dynamic || elf_dynsymtab (abfd) == 0)
1004 hdr = &elf_tdata (abfd)->symtab_hdr;
1005 else
1006 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
1008 if (dynamic)
1010 /* Read in any version definitions. */
1012 if (! _bfd_elf_slurp_version_tables (abfd))
1013 goto error_return;
1015 /* Read in the symbol versions, but don't bother to convert them
1016 to internal format. */
1017 if (elf_dynversym (abfd) != 0)
1019 Elf_Internal_Shdr *versymhdr;
1021 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
1022 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
1023 if (extversym == NULL)
1024 goto error_return;
1025 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
1026 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
1027 != versymhdr->sh_size))
1028 goto error_return;
1032 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
1034 /* The sh_info field of the symtab header tells us where the
1035 external symbols start. We don't care about the local symbols at
1036 this point. */
1037 if (elf_bad_symtab (abfd))
1039 extsymcount = symcount;
1040 extsymoff = 0;
1042 else
1044 extsymcount = symcount - hdr->sh_info;
1045 extsymoff = hdr->sh_info;
1048 buf = ((Elf_External_Sym *)
1049 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
1050 if (buf == NULL && extsymcount != 0)
1051 goto error_return;
1053 /* We store a pointer to the hash table entry for each external
1054 symbol. */
1055 sym_hash = ((struct elf_link_hash_entry **)
1056 bfd_alloc (abfd,
1057 extsymcount * sizeof (struct elf_link_hash_entry *)));
1058 if (sym_hash == NULL)
1059 goto error_return;
1060 elf_sym_hashes (abfd) = sym_hash;
1062 dt_needed = false;
1064 if (! dynamic)
1066 /* If we are creating a shared library, create all the dynamic
1067 sections immediately. We need to attach them to something,
1068 so we attach them to this BFD, provided it is the right
1069 format. FIXME: If there are no input BFD's of the same
1070 format as the output, we can't make a shared library. */
1071 if (info->shared
1072 && ! elf_hash_table (info)->dynamic_sections_created
1073 && abfd->xvec == info->hash->creator)
1075 if (! elf_link_create_dynamic_sections (abfd, info))
1076 goto error_return;
1079 else
1081 asection *s;
1082 boolean add_needed;
1083 const char *name;
1084 bfd_size_type oldsize;
1085 bfd_size_type strindex;
1087 /* Find the name to use in a DT_NEEDED entry that refers to this
1088 object. If the object has a DT_SONAME entry, we use it.
1089 Otherwise, if the generic linker stuck something in
1090 elf_dt_name, we use that. Otherwise, we just use the file
1091 name. If the generic linker put a null string into
1092 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
1093 there is a DT_SONAME entry. */
1094 add_needed = true;
1095 name = bfd_get_filename (abfd);
1096 if (elf_dt_name (abfd) != NULL)
1098 name = elf_dt_name (abfd);
1099 if (*name == '\0')
1101 if (elf_dt_soname (abfd) != NULL)
1102 dt_needed = true;
1104 add_needed = false;
1107 s = bfd_get_section_by_name (abfd, ".dynamic");
1108 if (s != NULL)
1110 Elf_External_Dyn *extdyn;
1111 Elf_External_Dyn *extdynend;
1112 int elfsec;
1113 unsigned long link;
1114 int rpath;
1115 int runpath;
1117 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
1118 if (dynbuf == NULL)
1119 goto error_return;
1121 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
1122 (file_ptr) 0, s->_raw_size))
1123 goto error_return;
1125 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1126 if (elfsec == -1)
1127 goto error_return;
1128 link = elf_elfsections (abfd)[elfsec]->sh_link;
1131 /* The shared libraries distributed with hpux11 have a bogus
1132 sh_link field for the ".dynamic" section. This code detects
1133 when LINK refers to a section that is not a string table and
1134 tries to find the string table for the ".dynsym" section
1135 instead. */
1136 Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[link];
1137 if (hdr->sh_type != SHT_STRTAB)
1139 asection *s = bfd_get_section_by_name (abfd, ".dynsym");
1140 int elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1141 if (elfsec == -1)
1142 goto error_return;
1143 link = elf_elfsections (abfd)[elfsec]->sh_link;
1147 extdyn = dynbuf;
1148 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
1149 rpath = 0;
1150 runpath = 0;
1151 for (; extdyn < extdynend; extdyn++)
1153 Elf_Internal_Dyn dyn;
1155 elf_swap_dyn_in (abfd, extdyn, &dyn);
1156 if (dyn.d_tag == DT_SONAME)
1158 name = bfd_elf_string_from_elf_section (abfd, link,
1159 dyn.d_un.d_val);
1160 if (name == NULL)
1161 goto error_return;
1163 if (dyn.d_tag == DT_NEEDED)
1165 struct bfd_link_needed_list *n, **pn;
1166 char *fnm, *anm;
1168 n = ((struct bfd_link_needed_list *)
1169 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1170 fnm = bfd_elf_string_from_elf_section (abfd, link,
1171 dyn.d_un.d_val);
1172 if (n == NULL || fnm == NULL)
1173 goto error_return;
1174 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1175 if (anm == NULL)
1176 goto error_return;
1177 strcpy (anm, fnm);
1178 n->name = anm;
1179 n->by = abfd;
1180 n->next = NULL;
1181 for (pn = &elf_hash_table (info)->needed;
1182 *pn != NULL;
1183 pn = &(*pn)->next)
1185 *pn = n;
1187 if (dyn.d_tag == DT_RUNPATH)
1189 struct bfd_link_needed_list *n, **pn;
1190 char *fnm, *anm;
1192 /* When we see DT_RPATH before DT_RUNPATH, we have
1193 to clear runpath. Do _NOT_ bfd_release, as that
1194 frees all more recently bfd_alloc'd blocks as
1195 well. */
1196 if (rpath && elf_hash_table (info)->runpath)
1197 elf_hash_table (info)->runpath = NULL;
1199 n = ((struct bfd_link_needed_list *)
1200 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1201 fnm = bfd_elf_string_from_elf_section (abfd, link,
1202 dyn.d_un.d_val);
1203 if (n == NULL || fnm == NULL)
1204 goto error_return;
1205 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1206 if (anm == NULL)
1207 goto error_return;
1208 strcpy (anm, fnm);
1209 n->name = anm;
1210 n->by = abfd;
1211 n->next = NULL;
1212 for (pn = &elf_hash_table (info)->runpath;
1213 *pn != NULL;
1214 pn = &(*pn)->next)
1216 *pn = n;
1217 runpath = 1;
1218 rpath = 0;
1220 /* Ignore DT_RPATH if we have seen DT_RUNPATH. */
1221 if (!runpath && dyn.d_tag == DT_RPATH)
1223 struct bfd_link_needed_list *n, **pn;
1224 char *fnm, *anm;
1226 n = ((struct bfd_link_needed_list *)
1227 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1228 fnm = bfd_elf_string_from_elf_section (abfd, link,
1229 dyn.d_un.d_val);
1230 if (n == NULL || fnm == NULL)
1231 goto error_return;
1232 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1233 if (anm == NULL)
1234 goto error_return;
1235 strcpy (anm, fnm);
1236 n->name = anm;
1237 n->by = abfd;
1238 n->next = NULL;
1239 for (pn = &elf_hash_table (info)->runpath;
1240 *pn != NULL;
1241 pn = &(*pn)->next)
1243 *pn = n;
1244 rpath = 1;
1248 free (dynbuf);
1249 dynbuf = NULL;
1252 /* We do not want to include any of the sections in a dynamic
1253 object in the output file. We hack by simply clobbering the
1254 list of sections in the BFD. This could be handled more
1255 cleanly by, say, a new section flag; the existing
1256 SEC_NEVER_LOAD flag is not the one we want, because that one
1257 still implies that the section takes up space in the output
1258 file. */
1259 abfd->sections = NULL;
1260 abfd->section_count = 0;
1262 /* If this is the first dynamic object found in the link, create
1263 the special sections required for dynamic linking. */
1264 if (! elf_hash_table (info)->dynamic_sections_created)
1266 if (! elf_link_create_dynamic_sections (abfd, info))
1267 goto error_return;
1270 if (add_needed)
1272 /* Add a DT_NEEDED entry for this dynamic object. */
1273 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1274 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
1275 true, false);
1276 if (strindex == (bfd_size_type) -1)
1277 goto error_return;
1279 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1281 asection *sdyn;
1282 Elf_External_Dyn *dyncon, *dynconend;
1284 /* The hash table size did not change, which means that
1285 the dynamic object name was already entered. If we
1286 have already included this dynamic object in the
1287 link, just ignore it. There is no reason to include
1288 a particular dynamic object more than once. */
1289 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1290 ".dynamic");
1291 BFD_ASSERT (sdyn != NULL);
1293 dyncon = (Elf_External_Dyn *) sdyn->contents;
1294 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1295 sdyn->_raw_size);
1296 for (; dyncon < dynconend; dyncon++)
1298 Elf_Internal_Dyn dyn;
1300 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
1301 &dyn);
1302 if (dyn.d_tag == DT_NEEDED
1303 && dyn.d_un.d_val == strindex)
1305 if (buf != NULL)
1306 free (buf);
1307 if (extversym != NULL)
1308 free (extversym);
1309 return true;
1314 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1315 goto error_return;
1318 /* Save the SONAME, if there is one, because sometimes the
1319 linker emulation code will need to know it. */
1320 if (*name == '\0')
1321 name = bfd_get_filename (abfd);
1322 elf_dt_name (abfd) = name;
1325 if (bfd_seek (abfd,
1326 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
1327 SEEK_SET) != 0
1328 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
1329 != extsymcount * sizeof (Elf_External_Sym)))
1330 goto error_return;
1332 weaks = NULL;
1334 ever = extversym != NULL ? extversym + extsymoff : NULL;
1335 esymend = buf + extsymcount;
1336 for (esym = buf;
1337 esym < esymend;
1338 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1340 Elf_Internal_Sym sym;
1341 int bind;
1342 bfd_vma value;
1343 asection *sec;
1344 flagword flags;
1345 const char *name;
1346 struct elf_link_hash_entry *h;
1347 boolean definition;
1348 boolean size_change_ok, type_change_ok;
1349 boolean new_weakdef;
1350 unsigned int old_alignment;
1352 elf_swap_symbol_in (abfd, esym, &sym);
1354 flags = BSF_NO_FLAGS;
1355 sec = NULL;
1356 value = sym.st_value;
1357 *sym_hash = NULL;
1359 bind = ELF_ST_BIND (sym.st_info);
1360 if (bind == STB_LOCAL)
1362 /* This should be impossible, since ELF requires that all
1363 global symbols follow all local symbols, and that sh_info
1364 point to the first global symbol. Unfortunatealy, Irix 5
1365 screws this up. */
1366 continue;
1368 else if (bind == STB_GLOBAL)
1370 if (sym.st_shndx != SHN_UNDEF
1371 && sym.st_shndx != SHN_COMMON)
1372 flags = BSF_GLOBAL;
1374 else if (bind == STB_WEAK)
1375 flags = BSF_WEAK;
1376 else
1378 /* Leave it up to the processor backend. */
1381 if (sym.st_shndx == SHN_UNDEF)
1382 sec = bfd_und_section_ptr;
1383 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1385 sec = section_from_elf_index (abfd, sym.st_shndx);
1386 if (sec == NULL)
1387 sec = bfd_abs_section_ptr;
1388 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1389 value -= sec->vma;
1391 else if (sym.st_shndx == SHN_ABS)
1392 sec = bfd_abs_section_ptr;
1393 else if (sym.st_shndx == SHN_COMMON)
1395 sec = bfd_com_section_ptr;
1396 /* What ELF calls the size we call the value. What ELF
1397 calls the value we call the alignment. */
1398 value = sym.st_size;
1400 else
1402 /* Leave it up to the processor backend. */
1405 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1406 if (name == (const char *) NULL)
1407 goto error_return;
1409 if (add_symbol_hook)
1411 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1412 &value))
1413 goto error_return;
1415 /* The hook function sets the name to NULL if this symbol
1416 should be skipped for some reason. */
1417 if (name == (const char *) NULL)
1418 continue;
1421 /* Sanity check that all possibilities were handled. */
1422 if (sec == (asection *) NULL)
1424 bfd_set_error (bfd_error_bad_value);
1425 goto error_return;
1428 if (bfd_is_und_section (sec)
1429 || bfd_is_com_section (sec))
1430 definition = false;
1431 else
1432 definition = true;
1434 size_change_ok = false;
1435 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1436 old_alignment = 0;
1437 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1439 Elf_Internal_Versym iver;
1440 unsigned int vernum = 0;
1441 boolean override;
1443 if (ever != NULL)
1445 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1446 vernum = iver.vs_vers & VERSYM_VERSION;
1448 /* If this is a hidden symbol, or if it is not version
1449 1, we append the version name to the symbol name.
1450 However, we do not modify a non-hidden absolute
1451 symbol, because it might be the version symbol
1452 itself. FIXME: What if it isn't? */
1453 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1454 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1456 const char *verstr;
1457 int namelen, newlen;
1458 char *newname, *p;
1460 if (sym.st_shndx != SHN_UNDEF)
1462 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1464 (*_bfd_error_handler)
1465 (_("%s: %s: invalid version %u (max %d)"),
1466 bfd_get_filename (abfd), name, vernum,
1467 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1468 bfd_set_error (bfd_error_bad_value);
1469 goto error_return;
1471 else if (vernum > 1)
1472 verstr =
1473 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1474 else
1475 verstr = "";
1477 else
1479 /* We cannot simply test for the number of
1480 entries in the VERNEED section since the
1481 numbers for the needed versions do not start
1482 at 0. */
1483 Elf_Internal_Verneed *t;
1485 verstr = NULL;
1486 for (t = elf_tdata (abfd)->verref;
1487 t != NULL;
1488 t = t->vn_nextref)
1490 Elf_Internal_Vernaux *a;
1492 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1494 if (a->vna_other == vernum)
1496 verstr = a->vna_nodename;
1497 break;
1500 if (a != NULL)
1501 break;
1503 if (verstr == NULL)
1505 (*_bfd_error_handler)
1506 (_("%s: %s: invalid needed version %d"),
1507 bfd_get_filename (abfd), name, vernum);
1508 bfd_set_error (bfd_error_bad_value);
1509 goto error_return;
1513 namelen = strlen (name);
1514 newlen = namelen + strlen (verstr) + 2;
1515 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1516 ++newlen;
1518 newname = (char *) bfd_alloc (abfd, newlen);
1519 if (newname == NULL)
1520 goto error_return;
1521 strcpy (newname, name);
1522 p = newname + namelen;
1523 *p++ = ELF_VER_CHR;
1524 /* If this is a defined non-hidden version symbol,
1525 we add another @ to the name. This indicates the
1526 default version of the symbol. */
1527 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
1528 && sym.st_shndx != SHN_UNDEF)
1529 *p++ = ELF_VER_CHR;
1530 strcpy (p, verstr);
1532 name = newname;
1536 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1537 sym_hash, &override, &type_change_ok,
1538 &size_change_ok, dt_needed))
1539 goto error_return;
1541 if (override)
1542 definition = false;
1544 h = *sym_hash;
1545 while (h->root.type == bfd_link_hash_indirect
1546 || h->root.type == bfd_link_hash_warning)
1547 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1549 /* Remember the old alignment if this is a common symbol, so
1550 that we don't reduce the alignment later on. We can't
1551 check later, because _bfd_generic_link_add_one_symbol
1552 will set a default for the alignment which we want to
1553 override. */
1554 if (h->root.type == bfd_link_hash_common)
1555 old_alignment = h->root.u.c.p->alignment_power;
1557 if (elf_tdata (abfd)->verdef != NULL
1558 && ! override
1559 && vernum > 1
1560 && definition)
1561 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1564 if (! (_bfd_generic_link_add_one_symbol
1565 (info, abfd, name, flags, sec, value, (const char *) NULL,
1566 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1567 goto error_return;
1569 h = *sym_hash;
1570 while (h->root.type == bfd_link_hash_indirect
1571 || h->root.type == bfd_link_hash_warning)
1572 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1573 *sym_hash = h;
1575 new_weakdef = false;
1576 if (dynamic
1577 && definition
1578 && (flags & BSF_WEAK) != 0
1579 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1580 && info->hash->creator->flavour == bfd_target_elf_flavour
1581 && h->weakdef == NULL)
1583 /* Keep a list of all weak defined non function symbols from
1584 a dynamic object, using the weakdef field. Later in this
1585 function we will set the weakdef field to the correct
1586 value. We only put non-function symbols from dynamic
1587 objects on this list, because that happens to be the only
1588 time we need to know the normal symbol corresponding to a
1589 weak symbol, and the information is time consuming to
1590 figure out. If the weakdef field is not already NULL,
1591 then this symbol was already defined by some previous
1592 dynamic object, and we will be using that previous
1593 definition anyhow. */
1595 h->weakdef = weaks;
1596 weaks = h;
1597 new_weakdef = true;
1600 /* Set the alignment of a common symbol. */
1601 if (sym.st_shndx == SHN_COMMON
1602 && h->root.type == bfd_link_hash_common)
1604 unsigned int align;
1606 align = bfd_log2 (sym.st_value);
1607 if (align > old_alignment
1608 /* Permit an alignment power of zero if an alignment of one
1609 is specified and no other alignments have been specified. */
1610 || (sym.st_value == 1 && old_alignment == 0))
1611 h->root.u.c.p->alignment_power = align;
1614 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1616 int old_flags;
1617 boolean dynsym;
1618 int new_flag;
1620 /* Remember the symbol size and type. */
1621 if (sym.st_size != 0
1622 && (definition || h->size == 0))
1624 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1625 (*_bfd_error_handler)
1626 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1627 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1628 bfd_get_filename (abfd));
1630 h->size = sym.st_size;
1633 /* If this is a common symbol, then we always want H->SIZE
1634 to be the size of the common symbol. The code just above
1635 won't fix the size if a common symbol becomes larger. We
1636 don't warn about a size change here, because that is
1637 covered by --warn-common. */
1638 if (h->root.type == bfd_link_hash_common)
1639 h->size = h->root.u.c.size;
1641 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1642 && (definition || h->type == STT_NOTYPE))
1644 if (h->type != STT_NOTYPE
1645 && h->type != ELF_ST_TYPE (sym.st_info)
1646 && ! type_change_ok)
1647 (*_bfd_error_handler)
1648 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1649 name, h->type, ELF_ST_TYPE (sym.st_info),
1650 bfd_get_filename (abfd));
1652 h->type = ELF_ST_TYPE (sym.st_info);
1655 /* If st_other has a processor-specific meaning, specific code
1656 might be needed here. */
1657 if (sym.st_other != 0)
1659 /* Combine visibilities, using the most constraining one. */
1660 unsigned char hvis = ELF_ST_VISIBILITY (h->other);
1661 unsigned char symvis = ELF_ST_VISIBILITY (sym.st_other);
1663 if (symvis && (hvis > symvis || hvis == 0))
1664 h->other = sym.st_other;
1666 /* If neither has visibility, use the st_other of the
1667 definition. This is an arbitrary choice, since the
1668 other bits have no general meaning. */
1669 if (!symvis && !hvis
1670 && (definition || h->other == 0))
1671 h->other = sym.st_other;
1674 /* Set a flag in the hash table entry indicating the type of
1675 reference or definition we just found. Keep a count of
1676 the number of dynamic symbols we find. A dynamic symbol
1677 is one which is referenced or defined by both a regular
1678 object and a shared object. */
1679 old_flags = h->elf_link_hash_flags;
1680 dynsym = false;
1681 if (! dynamic)
1683 if (! definition)
1685 new_flag = ELF_LINK_HASH_REF_REGULAR;
1686 if (bind != STB_WEAK)
1687 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1689 else
1690 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1691 if (info->shared
1692 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1693 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1694 dynsym = true;
1696 else
1698 if (! definition)
1699 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1700 else
1701 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1702 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1703 | ELF_LINK_HASH_REF_REGULAR)) != 0
1704 || (h->weakdef != NULL
1705 && ! new_weakdef
1706 && h->weakdef->dynindx != -1))
1707 dynsym = true;
1710 h->elf_link_hash_flags |= new_flag;
1712 /* If this symbol has a version, and it is the default
1713 version, we create an indirect symbol from the default
1714 name to the fully decorated name. This will cause
1715 external references which do not specify a version to be
1716 bound to this version of the symbol. */
1717 if (definition || h->root.type == bfd_link_hash_common)
1719 char *p;
1721 p = strchr (name, ELF_VER_CHR);
1722 if (p != NULL && p[1] == ELF_VER_CHR)
1724 char *shortname;
1725 struct elf_link_hash_entry *hi;
1726 boolean override;
1728 shortname = bfd_hash_allocate (&info->hash->table,
1729 p - name + 1);
1730 if (shortname == NULL)
1731 goto error_return;
1732 strncpy (shortname, name, p - name);
1733 shortname[p - name] = '\0';
1735 /* We are going to create a new symbol. Merge it
1736 with any existing symbol with this name. For the
1737 purposes of the merge, act as though we were
1738 defining the symbol we just defined, although we
1739 actually going to define an indirect symbol. */
1740 type_change_ok = false;
1741 size_change_ok = false;
1742 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1743 &value, &hi, &override,
1744 &type_change_ok,
1745 &size_change_ok, dt_needed))
1746 goto error_return;
1748 if (! override)
1750 if (! (_bfd_generic_link_add_one_symbol
1751 (info, abfd, shortname, BSF_INDIRECT,
1752 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1753 collect, (struct bfd_link_hash_entry **) &hi)))
1754 goto error_return;
1756 else
1758 /* In this case the symbol named SHORTNAME is
1759 overriding the indirect symbol we want to
1760 add. We were planning on making SHORTNAME an
1761 indirect symbol referring to NAME. SHORTNAME
1762 is the name without a version. NAME is the
1763 fully versioned name, and it is the default
1764 version.
1766 Overriding means that we already saw a
1767 definition for the symbol SHORTNAME in a
1768 regular object, and it is overriding the
1769 symbol defined in the dynamic object.
1771 When this happens, we actually want to change
1772 NAME, the symbol we just added, to refer to
1773 SHORTNAME. This will cause references to
1774 NAME in the shared object to become
1775 references to SHORTNAME in the regular
1776 object. This is what we expect when we
1777 override a function in a shared object: that
1778 the references in the shared object will be
1779 mapped to the definition in the regular
1780 object. */
1782 while (hi->root.type == bfd_link_hash_indirect
1783 || hi->root.type == bfd_link_hash_warning)
1784 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1786 h->root.type = bfd_link_hash_indirect;
1787 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1788 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1790 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1791 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1792 if (hi->elf_link_hash_flags
1793 & (ELF_LINK_HASH_REF_REGULAR
1794 | ELF_LINK_HASH_DEF_REGULAR))
1796 if (! _bfd_elf_link_record_dynamic_symbol (info,
1797 hi))
1798 goto error_return;
1802 /* Now set HI to H, so that the following code
1803 will set the other fields correctly. */
1804 hi = h;
1807 /* If there is a duplicate definition somewhere,
1808 then HI may not point to an indirect symbol. We
1809 will have reported an error to the user in that
1810 case. */
1812 if (hi->root.type == bfd_link_hash_indirect)
1814 struct elf_link_hash_entry *ht;
1816 /* If the symbol became indirect, then we assume
1817 that we have not seen a definition before. */
1818 BFD_ASSERT ((hi->elf_link_hash_flags
1819 & (ELF_LINK_HASH_DEF_DYNAMIC
1820 | ELF_LINK_HASH_DEF_REGULAR))
1821 == 0);
1823 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1824 (*bed->elf_backend_copy_indirect_symbol) (ht, hi);
1826 /* See if the new flags lead us to realize that
1827 the symbol must be dynamic. */
1828 if (! dynsym)
1830 if (! dynamic)
1832 if (info->shared
1833 || ((hi->elf_link_hash_flags
1834 & ELF_LINK_HASH_REF_DYNAMIC)
1835 != 0))
1836 dynsym = true;
1838 else
1840 if ((hi->elf_link_hash_flags
1841 & ELF_LINK_HASH_REF_REGULAR) != 0)
1842 dynsym = true;
1847 /* We also need to define an indirection from the
1848 nondefault version of the symbol. */
1850 shortname = bfd_hash_allocate (&info->hash->table,
1851 strlen (name));
1852 if (shortname == NULL)
1853 goto error_return;
1854 strncpy (shortname, name, p - name);
1855 strcpy (shortname + (p - name), p + 1);
1857 /* Once again, merge with any existing symbol. */
1858 type_change_ok = false;
1859 size_change_ok = false;
1860 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1861 &value, &hi, &override,
1862 &type_change_ok,
1863 &size_change_ok, dt_needed))
1864 goto error_return;
1866 if (override)
1868 /* Here SHORTNAME is a versioned name, so we
1869 don't expect to see the type of override we
1870 do in the case above. */
1871 (*_bfd_error_handler)
1872 (_("%s: warning: unexpected redefinition of `%s'"),
1873 bfd_get_filename (abfd), shortname);
1875 else
1877 if (! (_bfd_generic_link_add_one_symbol
1878 (info, abfd, shortname, BSF_INDIRECT,
1879 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1880 collect, (struct bfd_link_hash_entry **) &hi)))
1881 goto error_return;
1883 /* If there is a duplicate definition somewhere,
1884 then HI may not point to an indirect symbol.
1885 We will have reported an error to the user in
1886 that case. */
1888 if (hi->root.type == bfd_link_hash_indirect)
1890 /* If the symbol became indirect, then we
1891 assume that we have not seen a definition
1892 before. */
1893 BFD_ASSERT ((hi->elf_link_hash_flags
1894 & (ELF_LINK_HASH_DEF_DYNAMIC
1895 | ELF_LINK_HASH_DEF_REGULAR))
1896 == 0);
1898 (*bed->elf_backend_copy_indirect_symbol) (h, hi);
1900 /* See if the new flags lead us to realize
1901 that the symbol must be dynamic. */
1902 if (! dynsym)
1904 if (! dynamic)
1906 if (info->shared
1907 || ((hi->elf_link_hash_flags
1908 & ELF_LINK_HASH_REF_DYNAMIC)
1909 != 0))
1910 dynsym = true;
1912 else
1914 if ((hi->elf_link_hash_flags
1915 & ELF_LINK_HASH_REF_REGULAR) != 0)
1916 dynsym = true;
1924 if (dynsym && h->dynindx == -1)
1926 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1927 goto error_return;
1928 if (h->weakdef != NULL
1929 && ! new_weakdef
1930 && h->weakdef->dynindx == -1)
1932 if (! _bfd_elf_link_record_dynamic_symbol (info,
1933 h->weakdef))
1934 goto error_return;
1937 else if (dynsym && h->dynindx != -1)
1938 /* If the symbol already has a dynamic index, but
1939 visibility says it should not be visible, turn it into
1940 a local symbol. */
1941 switch (ELF_ST_VISIBILITY (h->other))
1943 case STV_INTERNAL:
1944 case STV_HIDDEN:
1945 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
1946 (*bed->elf_backend_hide_symbol) (info, h);
1947 break;
1950 if (dt_needed && definition
1951 && (h->elf_link_hash_flags
1952 & ELF_LINK_HASH_REF_REGULAR) != 0)
1954 bfd_size_type oldsize;
1955 bfd_size_type strindex;
1957 /* The symbol from a DT_NEEDED object is referenced from
1958 the regular object to create a dynamic executable. We
1959 have to make sure there is a DT_NEEDED entry for it. */
1961 dt_needed = false;
1962 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1963 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
1964 elf_dt_soname (abfd),
1965 true, false);
1966 if (strindex == (bfd_size_type) -1)
1967 goto error_return;
1969 if (oldsize
1970 == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1972 asection *sdyn;
1973 Elf_External_Dyn *dyncon, *dynconend;
1975 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1976 ".dynamic");
1977 BFD_ASSERT (sdyn != NULL);
1979 dyncon = (Elf_External_Dyn *) sdyn->contents;
1980 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1981 sdyn->_raw_size);
1982 for (; dyncon < dynconend; dyncon++)
1984 Elf_Internal_Dyn dyn;
1986 elf_swap_dyn_in (elf_hash_table (info)->dynobj,
1987 dyncon, &dyn);
1988 BFD_ASSERT (dyn.d_tag != DT_NEEDED ||
1989 dyn.d_un.d_val != strindex);
1993 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1994 goto error_return;
1999 /* Now set the weakdefs field correctly for all the weak defined
2000 symbols we found. The only way to do this is to search all the
2001 symbols. Since we only need the information for non functions in
2002 dynamic objects, that's the only time we actually put anything on
2003 the list WEAKS. We need this information so that if a regular
2004 object refers to a symbol defined weakly in a dynamic object, the
2005 real symbol in the dynamic object is also put in the dynamic
2006 symbols; we also must arrange for both symbols to point to the
2007 same memory location. We could handle the general case of symbol
2008 aliasing, but a general symbol alias can only be generated in
2009 assembler code, handling it correctly would be very time
2010 consuming, and other ELF linkers don't handle general aliasing
2011 either. */
2012 while (weaks != NULL)
2014 struct elf_link_hash_entry *hlook;
2015 asection *slook;
2016 bfd_vma vlook;
2017 struct elf_link_hash_entry **hpp;
2018 struct elf_link_hash_entry **hppend;
2020 hlook = weaks;
2021 weaks = hlook->weakdef;
2022 hlook->weakdef = NULL;
2024 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
2025 || hlook->root.type == bfd_link_hash_defweak
2026 || hlook->root.type == bfd_link_hash_common
2027 || hlook->root.type == bfd_link_hash_indirect);
2028 slook = hlook->root.u.def.section;
2029 vlook = hlook->root.u.def.value;
2031 hpp = elf_sym_hashes (abfd);
2032 hppend = hpp + extsymcount;
2033 for (; hpp < hppend; hpp++)
2035 struct elf_link_hash_entry *h;
2037 h = *hpp;
2038 if (h != NULL && h != hlook
2039 && h->root.type == bfd_link_hash_defined
2040 && h->root.u.def.section == slook
2041 && h->root.u.def.value == vlook)
2043 hlook->weakdef = h;
2045 /* If the weak definition is in the list of dynamic
2046 symbols, make sure the real definition is put there
2047 as well. */
2048 if (hlook->dynindx != -1
2049 && h->dynindx == -1)
2051 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2052 goto error_return;
2055 /* If the real definition is in the list of dynamic
2056 symbols, make sure the weak definition is put there
2057 as well. If we don't do this, then the dynamic
2058 loader might not merge the entries for the real
2059 definition and the weak definition. */
2060 if (h->dynindx != -1
2061 && hlook->dynindx == -1)
2063 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
2064 goto error_return;
2067 break;
2072 if (buf != NULL)
2074 free (buf);
2075 buf = NULL;
2078 if (extversym != NULL)
2080 free (extversym);
2081 extversym = NULL;
2084 /* If this object is the same format as the output object, and it is
2085 not a shared library, then let the backend look through the
2086 relocs.
2088 This is required to build global offset table entries and to
2089 arrange for dynamic relocs. It is not required for the
2090 particular common case of linking non PIC code, even when linking
2091 against shared libraries, but unfortunately there is no way of
2092 knowing whether an object file has been compiled PIC or not.
2093 Looking through the relocs is not particularly time consuming.
2094 The problem is that we must either (1) keep the relocs in memory,
2095 which causes the linker to require additional runtime memory or
2096 (2) read the relocs twice from the input file, which wastes time.
2097 This would be a good case for using mmap.
2099 I have no idea how to handle linking PIC code into a file of a
2100 different format. It probably can't be done. */
2101 check_relocs = get_elf_backend_data (abfd)->check_relocs;
2102 if (! dynamic
2103 && abfd->xvec == info->hash->creator
2104 && check_relocs != NULL)
2106 asection *o;
2108 for (o = abfd->sections; o != NULL; o = o->next)
2110 Elf_Internal_Rela *internal_relocs;
2111 boolean ok;
2113 if ((o->flags & SEC_RELOC) == 0
2114 || o->reloc_count == 0
2115 || ((info->strip == strip_all || info->strip == strip_debugger)
2116 && (o->flags & SEC_DEBUGGING) != 0)
2117 || bfd_is_abs_section (o->output_section))
2118 continue;
2120 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
2121 (abfd, o, (PTR) NULL,
2122 (Elf_Internal_Rela *) NULL,
2123 info->keep_memory));
2124 if (internal_relocs == NULL)
2125 goto error_return;
2127 ok = (*check_relocs) (abfd, info, o, internal_relocs);
2129 if (! info->keep_memory)
2130 free (internal_relocs);
2132 if (! ok)
2133 goto error_return;
2137 /* If this is a non-traditional, non-relocateable link, try to
2138 optimize the handling of the .stab/.stabstr sections. */
2139 if (! dynamic
2140 && ! info->relocateable
2141 && ! info->traditional_format
2142 && info->hash->creator->flavour == bfd_target_elf_flavour
2143 && (info->strip != strip_all && info->strip != strip_debugger))
2145 asection *stab, *stabstr;
2147 stab = bfd_get_section_by_name (abfd, ".stab");
2148 if (stab != NULL)
2150 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
2152 if (stabstr != NULL)
2154 struct bfd_elf_section_data *secdata;
2156 secdata = elf_section_data (stab);
2157 if (! _bfd_link_section_stabs (abfd,
2158 &elf_hash_table (info)->stab_info,
2159 stab, stabstr,
2160 &secdata->stab_info))
2161 goto error_return;
2166 return true;
2168 error_return:
2169 if (buf != NULL)
2170 free (buf);
2171 if (dynbuf != NULL)
2172 free (dynbuf);
2173 if (dynver != NULL)
2174 free (dynver);
2175 if (extversym != NULL)
2176 free (extversym);
2177 return false;
2180 /* Create some sections which will be filled in with dynamic linking
2181 information. ABFD is an input file which requires dynamic sections
2182 to be created. The dynamic sections take up virtual memory space
2183 when the final executable is run, so we need to create them before
2184 addresses are assigned to the output sections. We work out the
2185 actual contents and size of these sections later. */
2187 boolean
2188 elf_link_create_dynamic_sections (abfd, info)
2189 bfd *abfd;
2190 struct bfd_link_info *info;
2192 flagword flags;
2193 register asection *s;
2194 struct elf_link_hash_entry *h;
2195 struct elf_backend_data *bed;
2197 if (elf_hash_table (info)->dynamic_sections_created)
2198 return true;
2200 /* Make sure that all dynamic sections use the same input BFD. */
2201 if (elf_hash_table (info)->dynobj == NULL)
2202 elf_hash_table (info)->dynobj = abfd;
2203 else
2204 abfd = elf_hash_table (info)->dynobj;
2206 /* Note that we set the SEC_IN_MEMORY flag for all of these
2207 sections. */
2208 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
2209 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2211 /* A dynamically linked executable has a .interp section, but a
2212 shared library does not. */
2213 if (! info->shared)
2215 s = bfd_make_section (abfd, ".interp");
2216 if (s == NULL
2217 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2218 return false;
2221 /* Create sections to hold version informations. These are removed
2222 if they are not needed. */
2223 s = bfd_make_section (abfd, ".gnu.version_d");
2224 if (s == NULL
2225 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2226 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2227 return false;
2229 s = bfd_make_section (abfd, ".gnu.version");
2230 if (s == NULL
2231 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2232 || ! bfd_set_section_alignment (abfd, s, 1))
2233 return false;
2235 s = bfd_make_section (abfd, ".gnu.version_r");
2236 if (s == NULL
2237 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2238 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2239 return false;
2241 s = bfd_make_section (abfd, ".dynsym");
2242 if (s == NULL
2243 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2244 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2245 return false;
2247 s = bfd_make_section (abfd, ".dynstr");
2248 if (s == NULL
2249 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2250 return false;
2252 /* Create a strtab to hold the dynamic symbol names. */
2253 if (elf_hash_table (info)->dynstr == NULL)
2255 elf_hash_table (info)->dynstr = elf_stringtab_init ();
2256 if (elf_hash_table (info)->dynstr == NULL)
2257 return false;
2260 s = bfd_make_section (abfd, ".dynamic");
2261 if (s == NULL
2262 || ! bfd_set_section_flags (abfd, s, flags)
2263 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2264 return false;
2266 /* The special symbol _DYNAMIC is always set to the start of the
2267 .dynamic section. This call occurs before we have processed the
2268 symbols for any dynamic object, so we don't have to worry about
2269 overriding a dynamic definition. We could set _DYNAMIC in a
2270 linker script, but we only want to define it if we are, in fact,
2271 creating a .dynamic section. We don't want to define it if there
2272 is no .dynamic section, since on some ELF platforms the start up
2273 code examines it to decide how to initialize the process. */
2274 h = NULL;
2275 if (! (_bfd_generic_link_add_one_symbol
2276 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
2277 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
2278 (struct bfd_link_hash_entry **) &h)))
2279 return false;
2280 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2281 h->type = STT_OBJECT;
2283 if (info->shared
2284 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
2285 return false;
2287 bed = get_elf_backend_data (abfd);
2289 s = bfd_make_section (abfd, ".hash");
2290 if (s == NULL
2291 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2292 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2293 return false;
2294 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
2296 /* Let the backend create the rest of the sections. This lets the
2297 backend set the right flags. The backend will normally create
2298 the .got and .plt sections. */
2299 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
2300 return false;
2302 elf_hash_table (info)->dynamic_sections_created = true;
2304 return true;
2307 /* Add an entry to the .dynamic table. */
2309 boolean
2310 elf_add_dynamic_entry (info, tag, val)
2311 struct bfd_link_info *info;
2312 bfd_vma tag;
2313 bfd_vma val;
2315 Elf_Internal_Dyn dyn;
2316 bfd *dynobj;
2317 asection *s;
2318 size_t newsize;
2319 bfd_byte *newcontents;
2321 dynobj = elf_hash_table (info)->dynobj;
2323 s = bfd_get_section_by_name (dynobj, ".dynamic");
2324 BFD_ASSERT (s != NULL);
2326 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
2327 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
2328 if (newcontents == NULL)
2329 return false;
2331 dyn.d_tag = tag;
2332 dyn.d_un.d_val = val;
2333 elf_swap_dyn_out (dynobj, &dyn,
2334 (Elf_External_Dyn *) (newcontents + s->_raw_size));
2336 s->_raw_size = newsize;
2337 s->contents = newcontents;
2339 return true;
2342 /* Record a new local dynamic symbol. */
2344 boolean
2345 elf_link_record_local_dynamic_symbol (info, input_bfd, input_indx)
2346 struct bfd_link_info *info;
2347 bfd *input_bfd;
2348 long input_indx;
2350 struct elf_link_local_dynamic_entry *entry;
2351 struct elf_link_hash_table *eht;
2352 struct bfd_strtab_hash *dynstr;
2353 Elf_External_Sym esym;
2354 unsigned long dynstr_index;
2355 char *name;
2357 /* See if the entry exists already. */
2358 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
2359 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
2360 return true;
2362 entry = (struct elf_link_local_dynamic_entry *)
2363 bfd_alloc (input_bfd, sizeof (*entry));
2364 if (entry == NULL)
2365 return false;
2367 /* Go find the symbol, so that we can find it's name. */
2368 if (bfd_seek (input_bfd,
2369 (elf_tdata (input_bfd)->symtab_hdr.sh_offset
2370 + input_indx * sizeof (Elf_External_Sym)),
2371 SEEK_SET) != 0
2372 || (bfd_read (&esym, sizeof (Elf_External_Sym), 1, input_bfd)
2373 != sizeof (Elf_External_Sym)))
2374 return false;
2375 elf_swap_symbol_in (input_bfd, &esym, &entry->isym);
2377 name = (bfd_elf_string_from_elf_section
2378 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
2379 entry->isym.st_name));
2381 dynstr = elf_hash_table (info)->dynstr;
2382 if (dynstr == NULL)
2384 /* Create a strtab to hold the dynamic symbol names. */
2385 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_stringtab_init ();
2386 if (dynstr == NULL)
2387 return false;
2390 dynstr_index = _bfd_stringtab_add (dynstr, name, true, false);
2391 if (dynstr_index == (unsigned long) -1)
2392 return false;
2393 entry->isym.st_name = dynstr_index;
2395 eht = elf_hash_table (info);
2397 entry->next = eht->dynlocal;
2398 eht->dynlocal = entry;
2399 entry->input_bfd = input_bfd;
2400 entry->input_indx = input_indx;
2401 eht->dynsymcount++;
2403 /* Whatever binding the symbol had before, it's now local. */
2404 entry->isym.st_info
2405 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
2407 /* The dynindx will be set at the end of size_dynamic_sections. */
2409 return true;
2413 /* Read and swap the relocs from the section indicated by SHDR. This
2414 may be either a REL or a RELA section. The relocations are
2415 translated into RELA relocations and stored in INTERNAL_RELOCS,
2416 which should have already been allocated to contain enough space.
2417 The EXTERNAL_RELOCS are a buffer where the external form of the
2418 relocations should be stored.
2420 Returns false if something goes wrong. */
2422 static boolean
2423 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2424 internal_relocs)
2425 bfd *abfd;
2426 Elf_Internal_Shdr *shdr;
2427 PTR external_relocs;
2428 Elf_Internal_Rela *internal_relocs;
2430 struct elf_backend_data *bed;
2432 /* If there aren't any relocations, that's OK. */
2433 if (!shdr)
2434 return true;
2436 /* Position ourselves at the start of the section. */
2437 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2438 return false;
2440 /* Read the relocations. */
2441 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2442 != shdr->sh_size)
2443 return false;
2445 bed = get_elf_backend_data (abfd);
2447 /* Convert the external relocations to the internal format. */
2448 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2450 Elf_External_Rel *erel;
2451 Elf_External_Rel *erelend;
2452 Elf_Internal_Rela *irela;
2453 Elf_Internal_Rel *irel;
2455 erel = (Elf_External_Rel *) external_relocs;
2456 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2457 irela = internal_relocs;
2458 irel = bfd_alloc (abfd, (bed->s->int_rels_per_ext_rel
2459 * sizeof (Elf_Internal_Rel)));
2460 for (; erel < erelend; erel++, irela += bed->s->int_rels_per_ext_rel)
2462 unsigned char i;
2464 if (bed->s->swap_reloc_in)
2465 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, irel);
2466 else
2467 elf_swap_reloc_in (abfd, erel, irel);
2469 for (i = 0; i < bed->s->int_rels_per_ext_rel; ++i)
2471 irela[i].r_offset = irel[i].r_offset;
2472 irela[i].r_info = irel[i].r_info;
2473 irela[i].r_addend = 0;
2477 else
2479 Elf_External_Rela *erela;
2480 Elf_External_Rela *erelaend;
2481 Elf_Internal_Rela *irela;
2483 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2485 erela = (Elf_External_Rela *) external_relocs;
2486 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2487 irela = internal_relocs;
2488 for (; erela < erelaend; erela++, irela += bed->s->int_rels_per_ext_rel)
2490 if (bed->s->swap_reloca_in)
2491 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, irela);
2492 else
2493 elf_swap_reloca_in (abfd, erela, irela);
2497 return true;
2500 /* Read and swap the relocs for a section O. They may have been
2501 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2502 not NULL, they are used as buffers to read into. They are known to
2503 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
2504 the return value is allocated using either malloc or bfd_alloc,
2505 according to the KEEP_MEMORY argument. If O has two relocation
2506 sections (both REL and RELA relocations), then the REL_HDR
2507 relocations will appear first in INTERNAL_RELOCS, followed by the
2508 REL_HDR2 relocations. */
2510 Elf_Internal_Rela *
2511 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2512 keep_memory)
2513 bfd *abfd;
2514 asection *o;
2515 PTR external_relocs;
2516 Elf_Internal_Rela *internal_relocs;
2517 boolean keep_memory;
2519 Elf_Internal_Shdr *rel_hdr;
2520 PTR alloc1 = NULL;
2521 Elf_Internal_Rela *alloc2 = NULL;
2522 struct elf_backend_data *bed = get_elf_backend_data (abfd);
2524 if (elf_section_data (o)->relocs != NULL)
2525 return elf_section_data (o)->relocs;
2527 if (o->reloc_count == 0)
2528 return NULL;
2530 rel_hdr = &elf_section_data (o)->rel_hdr;
2532 if (internal_relocs == NULL)
2534 size_t size;
2536 size = (o->reloc_count * bed->s->int_rels_per_ext_rel
2537 * sizeof (Elf_Internal_Rela));
2538 if (keep_memory)
2539 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2540 else
2541 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2542 if (internal_relocs == NULL)
2543 goto error_return;
2546 if (external_relocs == NULL)
2548 size_t size = (size_t) rel_hdr->sh_size;
2550 if (elf_section_data (o)->rel_hdr2)
2551 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2552 alloc1 = (PTR) bfd_malloc (size);
2553 if (alloc1 == NULL)
2554 goto error_return;
2555 external_relocs = alloc1;
2558 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2559 external_relocs,
2560 internal_relocs))
2561 goto error_return;
2562 if (!elf_link_read_relocs_from_section
2563 (abfd,
2564 elf_section_data (o)->rel_hdr2,
2565 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
2566 internal_relocs + (rel_hdr->sh_size / rel_hdr->sh_entsize
2567 * bed->s->int_rels_per_ext_rel)))
2568 goto error_return;
2570 /* Cache the results for next time, if we can. */
2571 if (keep_memory)
2572 elf_section_data (o)->relocs = internal_relocs;
2574 if (alloc1 != NULL)
2575 free (alloc1);
2577 /* Don't free alloc2, since if it was allocated we are passing it
2578 back (under the name of internal_relocs). */
2580 return internal_relocs;
2582 error_return:
2583 if (alloc1 != NULL)
2584 free (alloc1);
2585 if (alloc2 != NULL)
2586 free (alloc2);
2587 return NULL;
2591 /* Record an assignment to a symbol made by a linker script. We need
2592 this in case some dynamic object refers to this symbol. */
2594 /*ARGSUSED*/
2595 boolean
2596 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2597 bfd *output_bfd ATTRIBUTE_UNUSED;
2598 struct bfd_link_info *info;
2599 const char *name;
2600 boolean provide;
2602 struct elf_link_hash_entry *h;
2604 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2605 return true;
2607 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2608 if (h == NULL)
2609 return false;
2611 if (h->root.type == bfd_link_hash_new)
2612 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2614 /* If this symbol is being provided by the linker script, and it is
2615 currently defined by a dynamic object, but not by a regular
2616 object, then mark it as undefined so that the generic linker will
2617 force the correct value. */
2618 if (provide
2619 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2620 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2621 h->root.type = bfd_link_hash_undefined;
2623 /* If this symbol is not being provided by the linker script, and it is
2624 currently defined by a dynamic object, but not by a regular object,
2625 then clear out any version information because the symbol will not be
2626 associated with the dynamic object any more. */
2627 if (!provide
2628 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2629 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2630 h->verinfo.verdef = NULL;
2632 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2634 /* When possible, keep the original type of the symbol */
2635 if (h->type == STT_NOTYPE)
2636 h->type = STT_OBJECT;
2638 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2639 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2640 || info->shared)
2641 && h->dynindx == -1)
2643 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2644 return false;
2646 /* If this is a weak defined symbol, and we know a corresponding
2647 real symbol from the same dynamic object, make sure the real
2648 symbol is also made into a dynamic symbol. */
2649 if (h->weakdef != NULL
2650 && h->weakdef->dynindx == -1)
2652 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2653 return false;
2657 return true;
2660 /* This structure is used to pass information to
2661 elf_link_assign_sym_version. */
2663 struct elf_assign_sym_version_info
2665 /* Output BFD. */
2666 bfd *output_bfd;
2667 /* General link information. */
2668 struct bfd_link_info *info;
2669 /* Version tree. */
2670 struct bfd_elf_version_tree *verdefs;
2671 /* Whether we are exporting all dynamic symbols. */
2672 boolean export_dynamic;
2673 /* Whether we had a failure. */
2674 boolean failed;
2677 /* This structure is used to pass information to
2678 elf_link_find_version_dependencies. */
2680 struct elf_find_verdep_info
2682 /* Output BFD. */
2683 bfd *output_bfd;
2684 /* General link information. */
2685 struct bfd_link_info *info;
2686 /* The number of dependencies. */
2687 unsigned int vers;
2688 /* Whether we had a failure. */
2689 boolean failed;
2692 /* Array used to determine the number of hash table buckets to use
2693 based on the number of symbols there are. If there are fewer than
2694 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2695 fewer than 37 we use 17 buckets, and so forth. We never use more
2696 than 32771 buckets. */
2698 static const size_t elf_buckets[] =
2700 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2701 16411, 32771, 0
2704 /* Compute bucket count for hashing table. We do not use a static set
2705 of possible tables sizes anymore. Instead we determine for all
2706 possible reasonable sizes of the table the outcome (i.e., the
2707 number of collisions etc) and choose the best solution. The
2708 weighting functions are not too simple to allow the table to grow
2709 without bounds. Instead one of the weighting factors is the size.
2710 Therefore the result is always a good payoff between few collisions
2711 (= short chain lengths) and table size. */
2712 static size_t
2713 compute_bucket_count (info)
2714 struct bfd_link_info *info;
2716 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2717 size_t best_size = 0;
2718 unsigned long int *hashcodes;
2719 unsigned long int *hashcodesp;
2720 unsigned long int i;
2722 /* Compute the hash values for all exported symbols. At the same
2723 time store the values in an array so that we could use them for
2724 optimizations. */
2725 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2726 * sizeof (unsigned long int));
2727 if (hashcodes == NULL)
2728 return 0;
2729 hashcodesp = hashcodes;
2731 /* Put all hash values in HASHCODES. */
2732 elf_link_hash_traverse (elf_hash_table (info),
2733 elf_collect_hash_codes, &hashcodesp);
2735 /* We have a problem here. The following code to optimize the table
2736 size requires an integer type with more the 32 bits. If
2737 BFD_HOST_U_64_BIT is set we know about such a type. */
2738 #ifdef BFD_HOST_U_64_BIT
2739 if (info->optimize == true)
2741 unsigned long int nsyms = hashcodesp - hashcodes;
2742 size_t minsize;
2743 size_t maxsize;
2744 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2745 unsigned long int *counts ;
2747 /* Possible optimization parameters: if we have NSYMS symbols we say
2748 that the hashing table must at least have NSYMS/4 and at most
2749 2*NSYMS buckets. */
2750 minsize = nsyms / 4;
2751 if (minsize == 0)
2752 minsize = 1;
2753 best_size = maxsize = nsyms * 2;
2755 /* Create array where we count the collisions in. We must use bfd_malloc
2756 since the size could be large. */
2757 counts = (unsigned long int *) bfd_malloc (maxsize
2758 * sizeof (unsigned long int));
2759 if (counts == NULL)
2761 free (hashcodes);
2762 return 0;
2765 /* Compute the "optimal" size for the hash table. The criteria is a
2766 minimal chain length. The minor criteria is (of course) the size
2767 of the table. */
2768 for (i = minsize; i < maxsize; ++i)
2770 /* Walk through the array of hashcodes and count the collisions. */
2771 BFD_HOST_U_64_BIT max;
2772 unsigned long int j;
2773 unsigned long int fact;
2775 memset (counts, '\0', i * sizeof (unsigned long int));
2777 /* Determine how often each hash bucket is used. */
2778 for (j = 0; j < nsyms; ++j)
2779 ++counts[hashcodes[j] % i];
2781 /* For the weight function we need some information about the
2782 pagesize on the target. This is information need not be 100%
2783 accurate. Since this information is not available (so far) we
2784 define it here to a reasonable default value. If it is crucial
2785 to have a better value some day simply define this value. */
2786 # ifndef BFD_TARGET_PAGESIZE
2787 # define BFD_TARGET_PAGESIZE (4096)
2788 # endif
2790 /* We in any case need 2 + NSYMS entries for the size values and
2791 the chains. */
2792 max = (2 + nsyms) * (ARCH_SIZE / 8);
2794 # if 1
2795 /* Variant 1: optimize for short chains. We add the squares
2796 of all the chain lengths (which favous many small chain
2797 over a few long chains). */
2798 for (j = 0; j < i; ++j)
2799 max += counts[j] * counts[j];
2801 /* This adds penalties for the overall size of the table. */
2802 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2803 max *= fact * fact;
2804 # else
2805 /* Variant 2: Optimize a lot more for small table. Here we
2806 also add squares of the size but we also add penalties for
2807 empty slots (the +1 term). */
2808 for (j = 0; j < i; ++j)
2809 max += (1 + counts[j]) * (1 + counts[j]);
2811 /* The overall size of the table is considered, but not as
2812 strong as in variant 1, where it is squared. */
2813 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2814 max *= fact;
2815 # endif
2817 /* Compare with current best results. */
2818 if (max < best_chlen)
2820 best_chlen = max;
2821 best_size = i;
2825 free (counts);
2827 else
2828 #endif /* defined (BFD_HOST_U_64_BIT) */
2830 /* This is the fallback solution if no 64bit type is available or if we
2831 are not supposed to spend much time on optimizations. We select the
2832 bucket count using a fixed set of numbers. */
2833 for (i = 0; elf_buckets[i] != 0; i++)
2835 best_size = elf_buckets[i];
2836 if (dynsymcount < elf_buckets[i + 1])
2837 break;
2841 /* Free the arrays we needed. */
2842 free (hashcodes);
2844 return best_size;
2847 /* Set up the sizes and contents of the ELF dynamic sections. This is
2848 called by the ELF linker emulation before_allocation routine. We
2849 must set the sizes of the sections before the linker sets the
2850 addresses of the various sections. */
2852 boolean
2853 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2854 export_dynamic, filter_shlib,
2855 auxiliary_filters, info, sinterpptr,
2856 verdefs)
2857 bfd *output_bfd;
2858 const char *soname;
2859 const char *rpath;
2860 boolean export_dynamic;
2861 const char *filter_shlib;
2862 const char * const *auxiliary_filters;
2863 struct bfd_link_info *info;
2864 asection **sinterpptr;
2865 struct bfd_elf_version_tree *verdefs;
2867 bfd_size_type soname_indx;
2868 bfd *dynobj;
2869 struct elf_backend_data *bed;
2870 struct elf_assign_sym_version_info asvinfo;
2872 *sinterpptr = NULL;
2874 soname_indx = (bfd_size_type) -1;
2876 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2877 return true;
2879 /* The backend may have to create some sections regardless of whether
2880 we're dynamic or not. */
2881 bed = get_elf_backend_data (output_bfd);
2882 if (bed->elf_backend_always_size_sections
2883 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2884 return false;
2886 dynobj = elf_hash_table (info)->dynobj;
2888 /* If there were no dynamic objects in the link, there is nothing to
2889 do here. */
2890 if (dynobj == NULL)
2891 return true;
2893 if (elf_hash_table (info)->dynamic_sections_created)
2895 struct elf_info_failed eif;
2896 struct elf_link_hash_entry *h;
2897 asection *dynstr;
2899 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2900 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2902 if (soname != NULL)
2904 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2905 soname, true, true);
2906 if (soname_indx == (bfd_size_type) -1
2907 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2908 return false;
2911 if (info->symbolic)
2913 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2914 return false;
2915 info->flags |= DF_SYMBOLIC;
2918 if (rpath != NULL)
2920 bfd_size_type indx;
2922 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2923 true, true);
2924 if (indx == (bfd_size_type) -1
2925 || ! elf_add_dynamic_entry (info, DT_RPATH, indx)
2926 || (info->new_dtags
2927 && ! elf_add_dynamic_entry (info, DT_RUNPATH, indx)))
2928 return false;
2931 if (filter_shlib != NULL)
2933 bfd_size_type indx;
2935 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2936 filter_shlib, true, true);
2937 if (indx == (bfd_size_type) -1
2938 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2939 return false;
2942 if (auxiliary_filters != NULL)
2944 const char * const *p;
2946 for (p = auxiliary_filters; *p != NULL; p++)
2948 bfd_size_type indx;
2950 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2951 *p, true, true);
2952 if (indx == (bfd_size_type) -1
2953 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2954 return false;
2958 /* If we are supposed to export all symbols into the dynamic symbol
2959 table (this is not the normal case), then do so. */
2960 if (export_dynamic)
2962 struct elf_info_failed eif;
2964 eif.failed = false;
2965 eif.info = info;
2966 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2967 (PTR) &eif);
2968 if (eif.failed)
2969 return false;
2972 /* Attach all the symbols to their version information. */
2973 asvinfo.output_bfd = output_bfd;
2974 asvinfo.info = info;
2975 asvinfo.verdefs = verdefs;
2976 asvinfo.export_dynamic = export_dynamic;
2977 asvinfo.failed = false;
2979 elf_link_hash_traverse (elf_hash_table (info),
2980 elf_link_assign_sym_version,
2981 (PTR) &asvinfo);
2982 if (asvinfo.failed)
2983 return false;
2985 /* Find all symbols which were defined in a dynamic object and make
2986 the backend pick a reasonable value for them. */
2987 eif.failed = false;
2988 eif.info = info;
2989 elf_link_hash_traverse (elf_hash_table (info),
2990 elf_adjust_dynamic_symbol,
2991 (PTR) &eif);
2992 if (eif.failed)
2993 return false;
2995 /* Add some entries to the .dynamic section. We fill in some of the
2996 values later, in elf_bfd_final_link, but we must add the entries
2997 now so that we know the final size of the .dynamic section. */
2999 /* If there are initialization and/or finalization functions to
3000 call then add the corresponding DT_INIT/DT_FINI entries. */
3001 h = (info->init_function
3002 ? elf_link_hash_lookup (elf_hash_table (info),
3003 info->init_function, false,
3004 false, false)
3005 : NULL);
3006 if (h != NULL
3007 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
3008 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
3010 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
3011 return false;
3013 h = (info->fini_function
3014 ? elf_link_hash_lookup (elf_hash_table (info),
3015 info->fini_function, false,
3016 false, false)
3017 : NULL);
3018 if (h != NULL
3019 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
3020 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
3022 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
3023 return false;
3026 dynstr = bfd_get_section_by_name (dynobj, ".dynstr");
3027 /* If .dynstr is excluded from the link, we don't want any of
3028 these tags. Strictly, we should be checking each section
3029 individually; This quick check covers for the case where
3030 someone does a /DISCARD/ : { *(*) }. */
3031 if (dynstr != NULL && dynstr->output_section != bfd_abs_section_ptr)
3033 bfd_size_type strsize;
3035 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3036 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
3037 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
3038 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
3039 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
3040 || ! elf_add_dynamic_entry (info, DT_SYMENT,
3041 sizeof (Elf_External_Sym)))
3042 return false;
3046 /* The backend must work out the sizes of all the other dynamic
3047 sections. */
3048 if (bed->elf_backend_size_dynamic_sections
3049 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
3050 return false;
3052 if (elf_hash_table (info)->dynamic_sections_created)
3054 size_t dynsymcount;
3055 asection *s;
3056 size_t bucketcount = 0;
3057 size_t hash_entry_size;
3059 /* Set up the version definition section. */
3060 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
3061 BFD_ASSERT (s != NULL);
3063 /* We may have created additional version definitions if we are
3064 just linking a regular application. */
3065 verdefs = asvinfo.verdefs;
3067 if (verdefs == NULL)
3068 _bfd_strip_section_from_output (info, s);
3069 else
3071 unsigned int cdefs;
3072 bfd_size_type size;
3073 struct bfd_elf_version_tree *t;
3074 bfd_byte *p;
3075 Elf_Internal_Verdef def;
3076 Elf_Internal_Verdaux defaux;
3078 cdefs = 0;
3079 size = 0;
3081 /* Make space for the base version. */
3082 size += sizeof (Elf_External_Verdef);
3083 size += sizeof (Elf_External_Verdaux);
3084 ++cdefs;
3086 for (t = verdefs; t != NULL; t = t->next)
3088 struct bfd_elf_version_deps *n;
3090 size += sizeof (Elf_External_Verdef);
3091 size += sizeof (Elf_External_Verdaux);
3092 ++cdefs;
3094 for (n = t->deps; n != NULL; n = n->next)
3095 size += sizeof (Elf_External_Verdaux);
3098 s->_raw_size = size;
3099 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3100 if (s->contents == NULL && s->_raw_size != 0)
3101 return false;
3103 /* Fill in the version definition section. */
3105 p = s->contents;
3107 def.vd_version = VER_DEF_CURRENT;
3108 def.vd_flags = VER_FLG_BASE;
3109 def.vd_ndx = 1;
3110 def.vd_cnt = 1;
3111 def.vd_aux = sizeof (Elf_External_Verdef);
3112 def.vd_next = (sizeof (Elf_External_Verdef)
3113 + sizeof (Elf_External_Verdaux));
3115 if (soname_indx != (bfd_size_type) -1)
3117 def.vd_hash = bfd_elf_hash (soname);
3118 defaux.vda_name = soname_indx;
3120 else
3122 const char *name;
3123 bfd_size_type indx;
3125 name = output_bfd->filename;
3126 def.vd_hash = bfd_elf_hash (name);
3127 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3128 name, true, false);
3129 if (indx == (bfd_size_type) -1)
3130 return false;
3131 defaux.vda_name = indx;
3133 defaux.vda_next = 0;
3135 _bfd_elf_swap_verdef_out (output_bfd, &def,
3136 (Elf_External_Verdef *)p);
3137 p += sizeof (Elf_External_Verdef);
3138 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3139 (Elf_External_Verdaux *) p);
3140 p += sizeof (Elf_External_Verdaux);
3142 for (t = verdefs; t != NULL; t = t->next)
3144 unsigned int cdeps;
3145 struct bfd_elf_version_deps *n;
3146 struct elf_link_hash_entry *h;
3148 cdeps = 0;
3149 for (n = t->deps; n != NULL; n = n->next)
3150 ++cdeps;
3152 /* Add a symbol representing this version. */
3153 h = NULL;
3154 if (! (_bfd_generic_link_add_one_symbol
3155 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3156 (bfd_vma) 0, (const char *) NULL, false,
3157 get_elf_backend_data (dynobj)->collect,
3158 (struct bfd_link_hash_entry **) &h)))
3159 return false;
3160 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3161 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3162 h->type = STT_OBJECT;
3163 h->verinfo.vertree = t;
3165 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3166 return false;
3168 def.vd_version = VER_DEF_CURRENT;
3169 def.vd_flags = 0;
3170 if (t->globals == NULL && t->locals == NULL && ! t->used)
3171 def.vd_flags |= VER_FLG_WEAK;
3172 def.vd_ndx = t->vernum + 1;
3173 def.vd_cnt = cdeps + 1;
3174 def.vd_hash = bfd_elf_hash (t->name);
3175 def.vd_aux = sizeof (Elf_External_Verdef);
3176 if (t->next != NULL)
3177 def.vd_next = (sizeof (Elf_External_Verdef)
3178 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3179 else
3180 def.vd_next = 0;
3182 _bfd_elf_swap_verdef_out (output_bfd, &def,
3183 (Elf_External_Verdef *) p);
3184 p += sizeof (Elf_External_Verdef);
3186 defaux.vda_name = h->dynstr_index;
3187 if (t->deps == NULL)
3188 defaux.vda_next = 0;
3189 else
3190 defaux.vda_next = sizeof (Elf_External_Verdaux);
3191 t->name_indx = defaux.vda_name;
3193 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3194 (Elf_External_Verdaux *) p);
3195 p += sizeof (Elf_External_Verdaux);
3197 for (n = t->deps; n != NULL; n = n->next)
3199 if (n->version_needed == NULL)
3201 /* This can happen if there was an error in the
3202 version script. */
3203 defaux.vda_name = 0;
3205 else
3206 defaux.vda_name = n->version_needed->name_indx;
3207 if (n->next == NULL)
3208 defaux.vda_next = 0;
3209 else
3210 defaux.vda_next = sizeof (Elf_External_Verdaux);
3212 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3213 (Elf_External_Verdaux *) p);
3214 p += sizeof (Elf_External_Verdaux);
3218 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3219 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3220 return false;
3222 elf_tdata (output_bfd)->cverdefs = cdefs;
3225 if (info->new_dtags && info->flags)
3227 if (! elf_add_dynamic_entry (info, DT_FLAGS, info->flags))
3228 return false;
3231 if (info->flags_1)
3233 if (! info->shared)
3234 info->flags_1 &= ~ (DF_1_INITFIRST
3235 | DF_1_NODELETE
3236 | DF_1_NOOPEN);
3237 if (! elf_add_dynamic_entry (info, DT_FLAGS_1, info->flags_1))
3238 return false;
3241 /* Work out the size of the version reference section. */
3243 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3244 BFD_ASSERT (s != NULL);
3246 struct elf_find_verdep_info sinfo;
3248 sinfo.output_bfd = output_bfd;
3249 sinfo.info = info;
3250 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3251 if (sinfo.vers == 0)
3252 sinfo.vers = 1;
3253 sinfo.failed = false;
3255 elf_link_hash_traverse (elf_hash_table (info),
3256 elf_link_find_version_dependencies,
3257 (PTR) &sinfo);
3259 if (elf_tdata (output_bfd)->verref == NULL)
3260 _bfd_strip_section_from_output (info, s);
3261 else
3263 Elf_Internal_Verneed *t;
3264 unsigned int size;
3265 unsigned int crefs;
3266 bfd_byte *p;
3268 /* Build the version definition section. */
3269 size = 0;
3270 crefs = 0;
3271 for (t = elf_tdata (output_bfd)->verref;
3272 t != NULL;
3273 t = t->vn_nextref)
3275 Elf_Internal_Vernaux *a;
3277 size += sizeof (Elf_External_Verneed);
3278 ++crefs;
3279 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3280 size += sizeof (Elf_External_Vernaux);
3283 s->_raw_size = size;
3284 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3285 if (s->contents == NULL)
3286 return false;
3288 p = s->contents;
3289 for (t = elf_tdata (output_bfd)->verref;
3290 t != NULL;
3291 t = t->vn_nextref)
3293 unsigned int caux;
3294 Elf_Internal_Vernaux *a;
3295 bfd_size_type indx;
3297 caux = 0;
3298 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3299 ++caux;
3301 t->vn_version = VER_NEED_CURRENT;
3302 t->vn_cnt = caux;
3303 if (elf_dt_name (t->vn_bfd) != NULL)
3304 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3305 elf_dt_name (t->vn_bfd),
3306 true, false);
3307 else
3308 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3309 t->vn_bfd->filename, true, false);
3310 if (indx == (bfd_size_type) -1)
3311 return false;
3312 t->vn_file = indx;
3313 t->vn_aux = sizeof (Elf_External_Verneed);
3314 if (t->vn_nextref == NULL)
3315 t->vn_next = 0;
3316 else
3317 t->vn_next = (sizeof (Elf_External_Verneed)
3318 + caux * sizeof (Elf_External_Vernaux));
3320 _bfd_elf_swap_verneed_out (output_bfd, t,
3321 (Elf_External_Verneed *) p);
3322 p += sizeof (Elf_External_Verneed);
3324 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3326 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3327 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3328 a->vna_nodename, true, false);
3329 if (indx == (bfd_size_type) -1)
3330 return false;
3331 a->vna_name = indx;
3332 if (a->vna_nextptr == NULL)
3333 a->vna_next = 0;
3334 else
3335 a->vna_next = sizeof (Elf_External_Vernaux);
3337 _bfd_elf_swap_vernaux_out (output_bfd, a,
3338 (Elf_External_Vernaux *) p);
3339 p += sizeof (Elf_External_Vernaux);
3343 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3344 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3345 return false;
3347 elf_tdata (output_bfd)->cverrefs = crefs;
3351 /* Assign dynsym indicies. In a shared library we generate a
3352 section symbol for each output section, which come first.
3353 Next come all of the back-end allocated local dynamic syms,
3354 followed by the rest of the global symbols. */
3356 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3358 /* Work out the size of the symbol version section. */
3359 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3360 BFD_ASSERT (s != NULL);
3361 if (dynsymcount == 0
3362 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3364 _bfd_strip_section_from_output (info, s);
3365 /* The DYNSYMCOUNT might have changed if we were going to
3366 output a dynamic symbol table entry for S. */
3367 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3369 else
3371 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3372 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3373 if (s->contents == NULL)
3374 return false;
3376 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3377 return false;
3380 /* Set the size of the .dynsym and .hash sections. We counted
3381 the number of dynamic symbols in elf_link_add_object_symbols.
3382 We will build the contents of .dynsym and .hash when we build
3383 the final symbol table, because until then we do not know the
3384 correct value to give the symbols. We built the .dynstr
3385 section as we went along in elf_link_add_object_symbols. */
3386 s = bfd_get_section_by_name (dynobj, ".dynsym");
3387 BFD_ASSERT (s != NULL);
3388 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3389 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3390 if (s->contents == NULL && s->_raw_size != 0)
3391 return false;
3393 if (dynsymcount != 0)
3395 Elf_Internal_Sym isym;
3397 /* The first entry in .dynsym is a dummy symbol. */
3398 isym.st_value = 0;
3399 isym.st_size = 0;
3400 isym.st_name = 0;
3401 isym.st_info = 0;
3402 isym.st_other = 0;
3403 isym.st_shndx = 0;
3404 elf_swap_symbol_out (output_bfd, &isym,
3405 (PTR) (Elf_External_Sym *) s->contents);
3408 /* Compute the size of the hashing table. As a side effect this
3409 computes the hash values for all the names we export. */
3410 bucketcount = compute_bucket_count (info);
3412 s = bfd_get_section_by_name (dynobj, ".hash");
3413 BFD_ASSERT (s != NULL);
3414 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3415 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3416 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3417 if (s->contents == NULL)
3418 return false;
3419 memset (s->contents, 0, (size_t) s->_raw_size);
3421 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3422 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3423 s->contents + hash_entry_size);
3425 elf_hash_table (info)->bucketcount = bucketcount;
3427 s = bfd_get_section_by_name (dynobj, ".dynstr");
3428 BFD_ASSERT (s != NULL);
3429 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3431 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3432 return false;
3435 return true;
3438 /* Fix up the flags for a symbol. This handles various cases which
3439 can only be fixed after all the input files are seen. This is
3440 currently called by both adjust_dynamic_symbol and
3441 assign_sym_version, which is unnecessary but perhaps more robust in
3442 the face of future changes. */
3444 static boolean
3445 elf_fix_symbol_flags (h, eif)
3446 struct elf_link_hash_entry *h;
3447 struct elf_info_failed *eif;
3449 /* If this symbol was mentioned in a non-ELF file, try to set
3450 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3451 permit a non-ELF file to correctly refer to a symbol defined in
3452 an ELF dynamic object. */
3453 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3455 while (h->root.type == bfd_link_hash_indirect)
3456 h = (struct elf_link_hash_entry *) h->root.u.i.link;
3458 if (h->root.type != bfd_link_hash_defined
3459 && h->root.type != bfd_link_hash_defweak)
3460 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3461 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3462 else
3464 if (h->root.u.def.section->owner != NULL
3465 && (bfd_get_flavour (h->root.u.def.section->owner)
3466 == bfd_target_elf_flavour))
3467 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3468 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3469 else
3470 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3473 if (h->dynindx == -1
3474 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3475 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3477 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3479 eif->failed = true;
3480 return false;
3484 else
3486 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3487 was first seen in a non-ELF file. Fortunately, if the symbol
3488 was first seen in an ELF file, we're probably OK unless the
3489 symbol was defined in a non-ELF file. Catch that case here.
3490 FIXME: We're still in trouble if the symbol was first seen in
3491 a dynamic object, and then later in a non-ELF regular object. */
3492 if ((h->root.type == bfd_link_hash_defined
3493 || h->root.type == bfd_link_hash_defweak)
3494 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3495 && (h->root.u.def.section->owner != NULL
3496 ? (bfd_get_flavour (h->root.u.def.section->owner)
3497 != bfd_target_elf_flavour)
3498 : (bfd_is_abs_section (h->root.u.def.section)
3499 && (h->elf_link_hash_flags
3500 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3501 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3504 /* If this is a final link, and the symbol was defined as a common
3505 symbol in a regular object file, and there was no definition in
3506 any dynamic object, then the linker will have allocated space for
3507 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3508 flag will not have been set. */
3509 if (h->root.type == bfd_link_hash_defined
3510 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3511 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3512 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3513 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3514 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3516 /* If -Bsymbolic was used (which means to bind references to global
3517 symbols to the definition within the shared object), and this
3518 symbol was defined in a regular object, then it actually doesn't
3519 need a PLT entry. Likewise, if the symbol has any kind of
3520 visibility (internal, hidden, or protected), it doesn't need a
3521 PLT. */
3522 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3523 && eif->info->shared
3524 && (eif->info->symbolic || ELF_ST_VISIBILITY (h->other))
3525 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3527 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3528 h->plt.offset = (bfd_vma) -1;
3531 /* If this is a weak defined symbol in a dynamic object, and we know
3532 the real definition in the dynamic object, copy interesting flags
3533 over to the real definition. */
3534 if (h->weakdef != NULL)
3536 struct elf_link_hash_entry *weakdef;
3538 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3539 || h->root.type == bfd_link_hash_defweak);
3540 weakdef = h->weakdef;
3541 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3542 || weakdef->root.type == bfd_link_hash_defweak);
3543 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3545 /* If the real definition is defined by a regular object file,
3546 don't do anything special. See the longer description in
3547 elf_adjust_dynamic_symbol, below. */
3548 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3549 h->weakdef = NULL;
3550 else
3551 weakdef->elf_link_hash_flags |=
3552 (h->elf_link_hash_flags
3553 & (ELF_LINK_HASH_REF_REGULAR
3554 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3555 | ELF_LINK_NON_GOT_REF));
3558 return true;
3561 /* Make the backend pick a good value for a dynamic symbol. This is
3562 called via elf_link_hash_traverse, and also calls itself
3563 recursively. */
3565 static boolean
3566 elf_adjust_dynamic_symbol (h, data)
3567 struct elf_link_hash_entry *h;
3568 PTR data;
3570 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3571 bfd *dynobj;
3572 struct elf_backend_data *bed;
3574 /* Ignore indirect symbols. These are added by the versioning code. */
3575 if (h->root.type == bfd_link_hash_indirect)
3576 return true;
3578 /* Fix the symbol flags. */
3579 if (! elf_fix_symbol_flags (h, eif))
3580 return false;
3582 /* If this symbol does not require a PLT entry, and it is not
3583 defined by a dynamic object, or is not referenced by a regular
3584 object, ignore it. We do have to handle a weak defined symbol,
3585 even if no regular object refers to it, if we decided to add it
3586 to the dynamic symbol table. FIXME: Do we normally need to worry
3587 about symbols which are defined by one dynamic object and
3588 referenced by another one? */
3589 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3590 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3591 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3592 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3593 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3595 h->plt.offset = (bfd_vma) -1;
3596 return true;
3599 /* If we've already adjusted this symbol, don't do it again. This
3600 can happen via a recursive call. */
3601 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3602 return true;
3604 /* Don't look at this symbol again. Note that we must set this
3605 after checking the above conditions, because we may look at a
3606 symbol once, decide not to do anything, and then get called
3607 recursively later after REF_REGULAR is set below. */
3608 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3610 /* If this is a weak definition, and we know a real definition, and
3611 the real symbol is not itself defined by a regular object file,
3612 then get a good value for the real definition. We handle the
3613 real symbol first, for the convenience of the backend routine.
3615 Note that there is a confusing case here. If the real definition
3616 is defined by a regular object file, we don't get the real symbol
3617 from the dynamic object, but we do get the weak symbol. If the
3618 processor backend uses a COPY reloc, then if some routine in the
3619 dynamic object changes the real symbol, we will not see that
3620 change in the corresponding weak symbol. This is the way other
3621 ELF linkers work as well, and seems to be a result of the shared
3622 library model.
3624 I will clarify this issue. Most SVR4 shared libraries define the
3625 variable _timezone and define timezone as a weak synonym. The
3626 tzset call changes _timezone. If you write
3627 extern int timezone;
3628 int _timezone = 5;
3629 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3630 you might expect that, since timezone is a synonym for _timezone,
3631 the same number will print both times. However, if the processor
3632 backend uses a COPY reloc, then actually timezone will be copied
3633 into your process image, and, since you define _timezone
3634 yourself, _timezone will not. Thus timezone and _timezone will
3635 wind up at different memory locations. The tzset call will set
3636 _timezone, leaving timezone unchanged. */
3638 if (h->weakdef != NULL)
3640 /* If we get to this point, we know there is an implicit
3641 reference by a regular object file via the weak symbol H.
3642 FIXME: Is this really true? What if the traversal finds
3643 H->WEAKDEF before it finds H? */
3644 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3646 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3647 return false;
3650 /* If a symbol has no type and no size and does not require a PLT
3651 entry, then we are probably about to do the wrong thing here: we
3652 are probably going to create a COPY reloc for an empty object.
3653 This case can arise when a shared object is built with assembly
3654 code, and the assembly code fails to set the symbol type. */
3655 if (h->size == 0
3656 && h->type == STT_NOTYPE
3657 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3658 (*_bfd_error_handler)
3659 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3660 h->root.root.string);
3662 dynobj = elf_hash_table (eif->info)->dynobj;
3663 bed = get_elf_backend_data (dynobj);
3664 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3666 eif->failed = true;
3667 return false;
3670 return true;
3673 /* This routine is used to export all defined symbols into the dynamic
3674 symbol table. It is called via elf_link_hash_traverse. */
3676 static boolean
3677 elf_export_symbol (h, data)
3678 struct elf_link_hash_entry *h;
3679 PTR data;
3681 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3683 /* Ignore indirect symbols. These are added by the versioning code. */
3684 if (h->root.type == bfd_link_hash_indirect)
3685 return true;
3687 if (h->dynindx == -1
3688 && (h->elf_link_hash_flags
3689 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3691 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3693 eif->failed = true;
3694 return false;
3698 return true;
3701 /* Look through the symbols which are defined in other shared
3702 libraries and referenced here. Update the list of version
3703 dependencies. This will be put into the .gnu.version_r section.
3704 This function is called via elf_link_hash_traverse. */
3706 static boolean
3707 elf_link_find_version_dependencies (h, data)
3708 struct elf_link_hash_entry *h;
3709 PTR data;
3711 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3712 Elf_Internal_Verneed *t;
3713 Elf_Internal_Vernaux *a;
3715 /* We only care about symbols defined in shared objects with version
3716 information. */
3717 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3718 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3719 || h->dynindx == -1
3720 || h->verinfo.verdef == NULL)
3721 return true;
3723 /* See if we already know about this version. */
3724 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3726 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3727 continue;
3729 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3730 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3731 return true;
3733 break;
3736 /* This is a new version. Add it to tree we are building. */
3738 if (t == NULL)
3740 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3741 if (t == NULL)
3743 rinfo->failed = true;
3744 return false;
3747 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3748 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3749 elf_tdata (rinfo->output_bfd)->verref = t;
3752 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3754 /* Note that we are copying a string pointer here, and testing it
3755 above. If bfd_elf_string_from_elf_section is ever changed to
3756 discard the string data when low in memory, this will have to be
3757 fixed. */
3758 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3760 a->vna_flags = h->verinfo.verdef->vd_flags;
3761 a->vna_nextptr = t->vn_auxptr;
3763 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3764 ++rinfo->vers;
3766 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3768 t->vn_auxptr = a;
3770 return true;
3773 /* Figure out appropriate versions for all the symbols. We may not
3774 have the version number script until we have read all of the input
3775 files, so until that point we don't know which symbols should be
3776 local. This function is called via elf_link_hash_traverse. */
3778 static boolean
3779 elf_link_assign_sym_version (h, data)
3780 struct elf_link_hash_entry *h;
3781 PTR data;
3783 struct elf_assign_sym_version_info *sinfo =
3784 (struct elf_assign_sym_version_info *) data;
3785 struct bfd_link_info *info = sinfo->info;
3786 struct elf_backend_data *bed;
3787 struct elf_info_failed eif;
3788 char *p;
3790 /* Fix the symbol flags. */
3791 eif.failed = false;
3792 eif.info = info;
3793 if (! elf_fix_symbol_flags (h, &eif))
3795 if (eif.failed)
3796 sinfo->failed = true;
3797 return false;
3800 /* We only need version numbers for symbols defined in regular
3801 objects. */
3802 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3803 return true;
3805 bed = get_elf_backend_data (sinfo->output_bfd);
3806 p = strchr (h->root.root.string, ELF_VER_CHR);
3807 if (p != NULL && h->verinfo.vertree == NULL)
3809 struct bfd_elf_version_tree *t;
3810 boolean hidden;
3812 hidden = true;
3814 /* There are two consecutive ELF_VER_CHR characters if this is
3815 not a hidden symbol. */
3816 ++p;
3817 if (*p == ELF_VER_CHR)
3819 hidden = false;
3820 ++p;
3823 /* If there is no version string, we can just return out. */
3824 if (*p == '\0')
3826 if (hidden)
3827 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3828 return true;
3831 /* Look for the version. If we find it, it is no longer weak. */
3832 for (t = sinfo->verdefs; t != NULL; t = t->next)
3834 if (strcmp (t->name, p) == 0)
3836 int len;
3837 char *alc;
3838 struct bfd_elf_version_expr *d;
3840 len = p - h->root.root.string;
3841 alc = bfd_alloc (sinfo->output_bfd, len);
3842 if (alc == NULL)
3843 return false;
3844 strncpy (alc, h->root.root.string, len - 1);
3845 alc[len - 1] = '\0';
3846 if (alc[len - 2] == ELF_VER_CHR)
3847 alc[len - 2] = '\0';
3849 h->verinfo.vertree = t;
3850 t->used = true;
3851 d = NULL;
3853 if (t->globals != NULL)
3855 for (d = t->globals; d != NULL; d = d->next)
3856 if ((*d->match) (d, alc))
3857 break;
3860 /* See if there is anything to force this symbol to
3861 local scope. */
3862 if (d == NULL && t->locals != NULL)
3864 for (d = t->locals; d != NULL; d = d->next)
3866 if ((*d->match) (d, alc))
3868 if (h->dynindx != -1
3869 && info->shared
3870 && ! sinfo->export_dynamic)
3872 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3873 (*bed->elf_backend_hide_symbol) (info, h);
3874 /* FIXME: The name of the symbol has
3875 already been recorded in the dynamic
3876 string table section. */
3879 break;
3884 bfd_release (sinfo->output_bfd, alc);
3885 break;
3889 /* If we are building an application, we need to create a
3890 version node for this version. */
3891 if (t == NULL && ! info->shared)
3893 struct bfd_elf_version_tree **pp;
3894 int version_index;
3896 /* If we aren't going to export this symbol, we don't need
3897 to worry about it. */
3898 if (h->dynindx == -1)
3899 return true;
3901 t = ((struct bfd_elf_version_tree *)
3902 bfd_alloc (sinfo->output_bfd, sizeof *t));
3903 if (t == NULL)
3905 sinfo->failed = true;
3906 return false;
3909 t->next = NULL;
3910 t->name = p;
3911 t->globals = NULL;
3912 t->locals = NULL;
3913 t->deps = NULL;
3914 t->name_indx = (unsigned int) -1;
3915 t->used = true;
3917 version_index = 1;
3918 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3919 ++version_index;
3920 t->vernum = version_index;
3922 *pp = t;
3924 h->verinfo.vertree = t;
3926 else if (t == NULL)
3928 /* We could not find the version for a symbol when
3929 generating a shared archive. Return an error. */
3930 (*_bfd_error_handler)
3931 (_("%s: undefined versioned symbol name %s"),
3932 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3933 bfd_set_error (bfd_error_bad_value);
3934 sinfo->failed = true;
3935 return false;
3938 if (hidden)
3939 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3942 /* If we don't have a version for this symbol, see if we can find
3943 something. */
3944 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3946 struct bfd_elf_version_tree *t;
3947 struct bfd_elf_version_tree *deflt;
3948 struct bfd_elf_version_expr *d;
3950 /* See if can find what version this symbol is in. If the
3951 symbol is supposed to be local, then don't actually register
3952 it. */
3953 deflt = NULL;
3954 for (t = sinfo->verdefs; t != NULL; t = t->next)
3956 if (t->globals != NULL)
3958 for (d = t->globals; d != NULL; d = d->next)
3960 if ((*d->match) (d, h->root.root.string))
3962 h->verinfo.vertree = t;
3963 break;
3967 if (d != NULL)
3968 break;
3971 if (t->locals != NULL)
3973 for (d = t->locals; d != NULL; d = d->next)
3975 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3976 deflt = t;
3977 else if ((*d->match) (d, h->root.root.string))
3979 h->verinfo.vertree = t;
3980 if (h->dynindx != -1
3981 && info->shared
3982 && ! sinfo->export_dynamic)
3984 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3985 (*bed->elf_backend_hide_symbol) (info, h);
3986 /* FIXME: The name of the symbol has already
3987 been recorded in the dynamic string table
3988 section. */
3990 break;
3994 if (d != NULL)
3995 break;
3999 if (deflt != NULL && h->verinfo.vertree == NULL)
4001 h->verinfo.vertree = deflt;
4002 if (h->dynindx != -1
4003 && info->shared
4004 && ! sinfo->export_dynamic)
4006 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
4007 (*bed->elf_backend_hide_symbol) (info, h);
4008 /* FIXME: The name of the symbol has already been
4009 recorded in the dynamic string table section. */
4014 return true;
4017 /* Final phase of ELF linker. */
4019 /* A structure we use to avoid passing large numbers of arguments. */
4021 struct elf_final_link_info
4023 /* General link information. */
4024 struct bfd_link_info *info;
4025 /* Output BFD. */
4026 bfd *output_bfd;
4027 /* Symbol string table. */
4028 struct bfd_strtab_hash *symstrtab;
4029 /* .dynsym section. */
4030 asection *dynsym_sec;
4031 /* .hash section. */
4032 asection *hash_sec;
4033 /* symbol version section (.gnu.version). */
4034 asection *symver_sec;
4035 /* Buffer large enough to hold contents of any section. */
4036 bfd_byte *contents;
4037 /* Buffer large enough to hold external relocs of any section. */
4038 PTR external_relocs;
4039 /* Buffer large enough to hold internal relocs of any section. */
4040 Elf_Internal_Rela *internal_relocs;
4041 /* Buffer large enough to hold external local symbols of any input
4042 BFD. */
4043 Elf_External_Sym *external_syms;
4044 /* Buffer large enough to hold internal local symbols of any input
4045 BFD. */
4046 Elf_Internal_Sym *internal_syms;
4047 /* Array large enough to hold a symbol index for each local symbol
4048 of any input BFD. */
4049 long *indices;
4050 /* Array large enough to hold a section pointer for each local
4051 symbol of any input BFD. */
4052 asection **sections;
4053 /* Buffer to hold swapped out symbols. */
4054 Elf_External_Sym *symbuf;
4055 /* Number of swapped out symbols in buffer. */
4056 size_t symbuf_count;
4057 /* Number of symbols which fit in symbuf. */
4058 size_t symbuf_size;
4061 static boolean elf_link_output_sym
4062 PARAMS ((struct elf_final_link_info *, const char *,
4063 Elf_Internal_Sym *, asection *));
4064 static boolean elf_link_flush_output_syms
4065 PARAMS ((struct elf_final_link_info *));
4066 static boolean elf_link_output_extsym
4067 PARAMS ((struct elf_link_hash_entry *, PTR));
4068 static boolean elf_link_input_bfd
4069 PARAMS ((struct elf_final_link_info *, bfd *));
4070 static boolean elf_reloc_link_order
4071 PARAMS ((bfd *, struct bfd_link_info *, asection *,
4072 struct bfd_link_order *));
4074 /* This struct is used to pass information to elf_link_output_extsym. */
4076 struct elf_outext_info
4078 boolean failed;
4079 boolean localsyms;
4080 struct elf_final_link_info *finfo;
4083 /* Compute the size of, and allocate space for, REL_HDR which is the
4084 section header for a section containing relocations for O. */
4086 static boolean
4087 elf_link_size_reloc_section (abfd, rel_hdr, o)
4088 bfd *abfd;
4089 Elf_Internal_Shdr *rel_hdr;
4090 asection *o;
4092 register struct elf_link_hash_entry **p, **pend;
4093 unsigned reloc_count;
4095 /* Figure out how many relocations there will be. */
4096 if (rel_hdr == &elf_section_data (o)->rel_hdr)
4097 reloc_count = elf_section_data (o)->rel_count;
4098 else
4099 reloc_count = elf_section_data (o)->rel_count2;
4101 /* That allows us to calculate the size of the section. */
4102 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
4104 /* The contents field must last into write_object_contents, so we
4105 allocate it with bfd_alloc rather than malloc. Also since we
4106 cannot be sure that the contents will actually be filled in,
4107 we zero the allocated space. */
4108 rel_hdr->contents = (PTR) bfd_zalloc (abfd, rel_hdr->sh_size);
4109 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
4110 return false;
4112 /* We only allocate one set of hash entries, so we only do it the
4113 first time we are called. */
4114 if (elf_section_data (o)->rel_hashes == NULL)
4116 p = ((struct elf_link_hash_entry **)
4117 bfd_malloc (o->reloc_count
4118 * sizeof (struct elf_link_hash_entry *)));
4119 if (p == NULL && o->reloc_count != 0)
4120 return false;
4122 elf_section_data (o)->rel_hashes = p;
4123 pend = p + o->reloc_count;
4124 for (; p < pend; p++)
4125 *p = NULL;
4128 return true;
4131 /* When performing a relocateable link, the input relocations are
4132 preserved. But, if they reference global symbols, the indices
4133 referenced must be updated. Update all the relocations in
4134 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
4136 static void
4137 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
4138 bfd *abfd;
4139 Elf_Internal_Shdr *rel_hdr;
4140 unsigned int count;
4141 struct elf_link_hash_entry **rel_hash;
4143 unsigned int i;
4144 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4146 for (i = 0; i < count; i++, rel_hash++)
4148 if (*rel_hash == NULL)
4149 continue;
4151 BFD_ASSERT ((*rel_hash)->indx >= 0);
4153 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4155 Elf_External_Rel *erel;
4156 Elf_Internal_Rel irel;
4158 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4159 if (bed->s->swap_reloc_in)
4160 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, &irel);
4161 else
4162 elf_swap_reloc_in (abfd, erel, &irel);
4163 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4164 ELF_R_TYPE (irel.r_info));
4165 if (bed->s->swap_reloc_out)
4166 (*bed->s->swap_reloc_out) (abfd, &irel, (bfd_byte *) erel);
4167 else
4168 elf_swap_reloc_out (abfd, &irel, erel);
4170 else
4172 Elf_External_Rela *erela;
4173 Elf_Internal_Rela irela;
4175 BFD_ASSERT (rel_hdr->sh_entsize
4176 == sizeof (Elf_External_Rela));
4178 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4179 if (bed->s->swap_reloca_in)
4180 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, &irela);
4181 else
4182 elf_swap_reloca_in (abfd, erela, &irela);
4183 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4184 ELF_R_TYPE (irela.r_info));
4185 if (bed->s->swap_reloca_out)
4186 (*bed->s->swap_reloca_out) (abfd, &irela, (bfd_byte *) erela);
4187 else
4188 elf_swap_reloca_out (abfd, &irela, erela);
4193 /* Do the final step of an ELF link. */
4195 boolean
4196 elf_bfd_final_link (abfd, info)
4197 bfd *abfd;
4198 struct bfd_link_info *info;
4200 boolean dynamic;
4201 bfd *dynobj;
4202 struct elf_final_link_info finfo;
4203 register asection *o;
4204 register struct bfd_link_order *p;
4205 register bfd *sub;
4206 size_t max_contents_size;
4207 size_t max_external_reloc_size;
4208 size_t max_internal_reloc_count;
4209 size_t max_sym_count;
4210 file_ptr off;
4211 Elf_Internal_Sym elfsym;
4212 unsigned int i;
4213 Elf_Internal_Shdr *symtab_hdr;
4214 Elf_Internal_Shdr *symstrtab_hdr;
4215 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4216 struct elf_outext_info eoinfo;
4218 if (info->shared)
4219 abfd->flags |= DYNAMIC;
4221 dynamic = elf_hash_table (info)->dynamic_sections_created;
4222 dynobj = elf_hash_table (info)->dynobj;
4224 finfo.info = info;
4225 finfo.output_bfd = abfd;
4226 finfo.symstrtab = elf_stringtab_init ();
4227 if (finfo.symstrtab == NULL)
4228 return false;
4230 if (! dynamic)
4232 finfo.dynsym_sec = NULL;
4233 finfo.hash_sec = NULL;
4234 finfo.symver_sec = NULL;
4236 else
4238 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4239 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4240 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4241 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4242 /* Note that it is OK if symver_sec is NULL. */
4245 finfo.contents = NULL;
4246 finfo.external_relocs = NULL;
4247 finfo.internal_relocs = NULL;
4248 finfo.external_syms = NULL;
4249 finfo.internal_syms = NULL;
4250 finfo.indices = NULL;
4251 finfo.sections = NULL;
4252 finfo.symbuf = NULL;
4253 finfo.symbuf_count = 0;
4255 /* Count up the number of relocations we will output for each output
4256 section, so that we know the sizes of the reloc sections. We
4257 also figure out some maximum sizes. */
4258 max_contents_size = 0;
4259 max_external_reloc_size = 0;
4260 max_internal_reloc_count = 0;
4261 max_sym_count = 0;
4262 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4264 o->reloc_count = 0;
4266 for (p = o->link_order_head; p != NULL; p = p->next)
4268 if (p->type == bfd_section_reloc_link_order
4269 || p->type == bfd_symbol_reloc_link_order)
4270 ++o->reloc_count;
4271 else if (p->type == bfd_indirect_link_order)
4273 asection *sec;
4275 sec = p->u.indirect.section;
4277 /* Mark all sections which are to be included in the
4278 link. This will normally be every section. We need
4279 to do this so that we can identify any sections which
4280 the linker has decided to not include. */
4281 sec->linker_mark = true;
4283 if (info->relocateable || info->emitrelocations)
4284 o->reloc_count += sec->reloc_count;
4286 if (sec->_raw_size > max_contents_size)
4287 max_contents_size = sec->_raw_size;
4288 if (sec->_cooked_size > max_contents_size)
4289 max_contents_size = sec->_cooked_size;
4291 /* We are interested in just local symbols, not all
4292 symbols. */
4293 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4294 && (sec->owner->flags & DYNAMIC) == 0)
4296 size_t sym_count;
4298 if (elf_bad_symtab (sec->owner))
4299 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4300 / sizeof (Elf_External_Sym));
4301 else
4302 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4304 if (sym_count > max_sym_count)
4305 max_sym_count = sym_count;
4307 if ((sec->flags & SEC_RELOC) != 0)
4309 size_t ext_size;
4311 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4312 if (ext_size > max_external_reloc_size)
4313 max_external_reloc_size = ext_size;
4314 if (sec->reloc_count > max_internal_reloc_count)
4315 max_internal_reloc_count = sec->reloc_count;
4321 if (o->reloc_count > 0)
4322 o->flags |= SEC_RELOC;
4323 else
4325 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4326 set it (this is probably a bug) and if it is set
4327 assign_section_numbers will create a reloc section. */
4328 o->flags &=~ SEC_RELOC;
4331 /* If the SEC_ALLOC flag is not set, force the section VMA to
4332 zero. This is done in elf_fake_sections as well, but forcing
4333 the VMA to 0 here will ensure that relocs against these
4334 sections are handled correctly. */
4335 if ((o->flags & SEC_ALLOC) == 0
4336 && ! o->user_set_vma)
4337 o->vma = 0;
4340 /* Figure out the file positions for everything but the symbol table
4341 and the relocs. We set symcount to force assign_section_numbers
4342 to create a symbol table. */
4343 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4344 BFD_ASSERT (! abfd->output_has_begun);
4345 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4346 goto error_return;
4348 /* Figure out how many relocations we will have in each section.
4349 Just using RELOC_COUNT isn't good enough since that doesn't
4350 maintain a separate value for REL vs. RELA relocations. */
4351 if (info->relocateable || info->emitrelocations)
4352 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4353 for (o = sub->sections; o != NULL; o = o->next)
4355 asection *output_section;
4357 if (! o->linker_mark)
4359 /* This section was omitted from the link. */
4360 continue;
4363 output_section = o->output_section;
4365 if (output_section != NULL
4366 && (o->flags & SEC_RELOC) != 0)
4368 struct bfd_elf_section_data *esdi
4369 = elf_section_data (o);
4370 struct bfd_elf_section_data *esdo
4371 = elf_section_data (output_section);
4372 unsigned int *rel_count;
4373 unsigned int *rel_count2;
4375 /* We must be careful to add the relocation froms the
4376 input section to the right output count. */
4377 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4379 rel_count = &esdo->rel_count;
4380 rel_count2 = &esdo->rel_count2;
4382 else
4384 rel_count = &esdo->rel_count2;
4385 rel_count2 = &esdo->rel_count;
4388 *rel_count += (esdi->rel_hdr.sh_size
4389 / esdi->rel_hdr.sh_entsize);
4390 if (esdi->rel_hdr2)
4391 *rel_count2 += (esdi->rel_hdr2->sh_size
4392 / esdi->rel_hdr2->sh_entsize);
4396 /* That created the reloc sections. Set their sizes, and assign
4397 them file positions, and allocate some buffers. */
4398 for (o = abfd->sections; o != NULL; o = o->next)
4400 if ((o->flags & SEC_RELOC) != 0)
4402 if (!elf_link_size_reloc_section (abfd,
4403 &elf_section_data (o)->rel_hdr,
4405 goto error_return;
4407 if (elf_section_data (o)->rel_hdr2
4408 && !elf_link_size_reloc_section (abfd,
4409 elf_section_data (o)->rel_hdr2,
4411 goto error_return;
4414 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4415 to count upwards while actually outputting the relocations. */
4416 elf_section_data (o)->rel_count = 0;
4417 elf_section_data (o)->rel_count2 = 0;
4420 _bfd_elf_assign_file_positions_for_relocs (abfd);
4422 /* We have now assigned file positions for all the sections except
4423 .symtab and .strtab. We start the .symtab section at the current
4424 file position, and write directly to it. We build the .strtab
4425 section in memory. */
4426 bfd_get_symcount (abfd) = 0;
4427 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4428 /* sh_name is set in prep_headers. */
4429 symtab_hdr->sh_type = SHT_SYMTAB;
4430 symtab_hdr->sh_flags = 0;
4431 symtab_hdr->sh_addr = 0;
4432 symtab_hdr->sh_size = 0;
4433 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4434 /* sh_link is set in assign_section_numbers. */
4435 /* sh_info is set below. */
4436 /* sh_offset is set just below. */
4437 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4439 off = elf_tdata (abfd)->next_file_pos;
4440 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4442 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4443 incorrect. We do not yet know the size of the .symtab section.
4444 We correct next_file_pos below, after we do know the size. */
4446 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4447 continuously seeking to the right position in the file. */
4448 if (! info->keep_memory || max_sym_count < 20)
4449 finfo.symbuf_size = 20;
4450 else
4451 finfo.symbuf_size = max_sym_count;
4452 finfo.symbuf = ((Elf_External_Sym *)
4453 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4454 if (finfo.symbuf == NULL)
4455 goto error_return;
4457 /* Start writing out the symbol table. The first symbol is always a
4458 dummy symbol. */
4459 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4461 elfsym.st_value = 0;
4462 elfsym.st_size = 0;
4463 elfsym.st_info = 0;
4464 elfsym.st_other = 0;
4465 elfsym.st_shndx = SHN_UNDEF;
4466 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4467 &elfsym, bfd_und_section_ptr))
4468 goto error_return;
4471 #if 0
4472 /* Some standard ELF linkers do this, but we don't because it causes
4473 bootstrap comparison failures. */
4474 /* Output a file symbol for the output file as the second symbol.
4475 We output this even if we are discarding local symbols, although
4476 I'm not sure if this is correct. */
4477 elfsym.st_value = 0;
4478 elfsym.st_size = 0;
4479 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4480 elfsym.st_other = 0;
4481 elfsym.st_shndx = SHN_ABS;
4482 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4483 &elfsym, bfd_abs_section_ptr))
4484 goto error_return;
4485 #endif
4487 /* Output a symbol for each section. We output these even if we are
4488 discarding local symbols, since they are used for relocs. These
4489 symbols have no names. We store the index of each one in the
4490 index field of the section, so that we can find it again when
4491 outputting relocs. */
4492 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4494 elfsym.st_size = 0;
4495 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4496 elfsym.st_other = 0;
4497 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4499 o = section_from_elf_index (abfd, i);
4500 if (o != NULL)
4501 o->target_index = bfd_get_symcount (abfd);
4502 elfsym.st_shndx = i;
4503 if (info->relocateable || o == NULL)
4504 elfsym.st_value = 0;
4505 else
4506 elfsym.st_value = o->vma;
4507 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4508 &elfsym, o))
4509 goto error_return;
4513 /* Allocate some memory to hold information read in from the input
4514 files. */
4515 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4516 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4517 finfo.internal_relocs = ((Elf_Internal_Rela *)
4518 bfd_malloc (max_internal_reloc_count
4519 * sizeof (Elf_Internal_Rela)
4520 * bed->s->int_rels_per_ext_rel));
4521 finfo.external_syms = ((Elf_External_Sym *)
4522 bfd_malloc (max_sym_count
4523 * sizeof (Elf_External_Sym)));
4524 finfo.internal_syms = ((Elf_Internal_Sym *)
4525 bfd_malloc (max_sym_count
4526 * sizeof (Elf_Internal_Sym)));
4527 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4528 finfo.sections = ((asection **)
4529 bfd_malloc (max_sym_count * sizeof (asection *)));
4530 if ((finfo.contents == NULL && max_contents_size != 0)
4531 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4532 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4533 || (finfo.external_syms == NULL && max_sym_count != 0)
4534 || (finfo.internal_syms == NULL && max_sym_count != 0)
4535 || (finfo.indices == NULL && max_sym_count != 0)
4536 || (finfo.sections == NULL && max_sym_count != 0))
4537 goto error_return;
4539 /* Since ELF permits relocations to be against local symbols, we
4540 must have the local symbols available when we do the relocations.
4541 Since we would rather only read the local symbols once, and we
4542 would rather not keep them in memory, we handle all the
4543 relocations for a single input file at the same time.
4545 Unfortunately, there is no way to know the total number of local
4546 symbols until we have seen all of them, and the local symbol
4547 indices precede the global symbol indices. This means that when
4548 we are generating relocateable output, and we see a reloc against
4549 a global symbol, we can not know the symbol index until we have
4550 finished examining all the local symbols to see which ones we are
4551 going to output. To deal with this, we keep the relocations in
4552 memory, and don't output them until the end of the link. This is
4553 an unfortunate waste of memory, but I don't see a good way around
4554 it. Fortunately, it only happens when performing a relocateable
4555 link, which is not the common case. FIXME: If keep_memory is set
4556 we could write the relocs out and then read them again; I don't
4557 know how bad the memory loss will be. */
4559 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4560 sub->output_has_begun = false;
4561 for (o = abfd->sections; o != NULL; o = o->next)
4563 for (p = o->link_order_head; p != NULL; p = p->next)
4565 if (p->type == bfd_indirect_link_order
4566 && (bfd_get_flavour (p->u.indirect.section->owner)
4567 == bfd_target_elf_flavour))
4569 sub = p->u.indirect.section->owner;
4570 if (! sub->output_has_begun)
4572 if (! elf_link_input_bfd (&finfo, sub))
4573 goto error_return;
4574 sub->output_has_begun = true;
4577 else if (p->type == bfd_section_reloc_link_order
4578 || p->type == bfd_symbol_reloc_link_order)
4580 if (! elf_reloc_link_order (abfd, info, o, p))
4581 goto error_return;
4583 else
4585 if (! _bfd_default_link_order (abfd, info, o, p))
4586 goto error_return;
4591 /* That wrote out all the local symbols. Finish up the symbol table
4592 with the global symbols. Even if we want to strip everything we
4593 can, we still need to deal with those global symbols that got
4594 converted to local in a version script. */
4596 if (info->shared)
4598 /* Output any global symbols that got converted to local in a
4599 version script. We do this in a separate step since ELF
4600 requires all local symbols to appear prior to any global
4601 symbols. FIXME: We should only do this if some global
4602 symbols were, in fact, converted to become local. FIXME:
4603 Will this work correctly with the Irix 5 linker? */
4604 eoinfo.failed = false;
4605 eoinfo.finfo = &finfo;
4606 eoinfo.localsyms = true;
4607 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4608 (PTR) &eoinfo);
4609 if (eoinfo.failed)
4610 return false;
4613 /* The sh_info field records the index of the first non local symbol. */
4614 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4616 if (dynamic
4617 && finfo.dynsym_sec->output_section != bfd_abs_section_ptr)
4619 Elf_Internal_Sym sym;
4620 Elf_External_Sym *dynsym =
4621 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4622 long last_local = 0;
4624 /* Write out the section symbols for the output sections. */
4625 if (info->shared)
4627 asection *s;
4629 sym.st_size = 0;
4630 sym.st_name = 0;
4631 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4632 sym.st_other = 0;
4634 for (s = abfd->sections; s != NULL; s = s->next)
4636 int indx;
4637 indx = elf_section_data (s)->this_idx;
4638 BFD_ASSERT (indx > 0);
4639 sym.st_shndx = indx;
4640 sym.st_value = s->vma;
4642 elf_swap_symbol_out (abfd, &sym,
4643 dynsym + elf_section_data (s)->dynindx);
4646 last_local = bfd_count_sections (abfd);
4649 /* Write out the local dynsyms. */
4650 if (elf_hash_table (info)->dynlocal)
4652 struct elf_link_local_dynamic_entry *e;
4653 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4655 asection *s;
4657 sym.st_size = e->isym.st_size;
4658 sym.st_other = e->isym.st_other;
4660 /* Copy the internal symbol as is.
4661 Note that we saved a word of storage and overwrote
4662 the original st_name with the dynstr_index. */
4663 sym = e->isym;
4665 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4667 s = bfd_section_from_elf_index (e->input_bfd,
4668 e->isym.st_shndx);
4670 sym.st_shndx =
4671 elf_section_data (s->output_section)->this_idx;
4672 sym.st_value = (s->output_section->vma
4673 + s->output_offset
4674 + e->isym.st_value);
4677 if (last_local < e->dynindx)
4678 last_local = e->dynindx;
4680 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4684 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4685 last_local + 1;
4688 /* We get the global symbols from the hash table. */
4689 eoinfo.failed = false;
4690 eoinfo.localsyms = false;
4691 eoinfo.finfo = &finfo;
4692 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4693 (PTR) &eoinfo);
4694 if (eoinfo.failed)
4695 return false;
4697 /* If backend needs to output some symbols not present in the hash
4698 table, do it now. */
4699 if (bed->elf_backend_output_arch_syms)
4701 if (! (*bed->elf_backend_output_arch_syms)
4702 (abfd, info, (PTR) &finfo,
4703 (boolean (*) PARAMS ((PTR, const char *,
4704 Elf_Internal_Sym *, asection *)))
4705 elf_link_output_sym))
4706 return false;
4709 /* Flush all symbols to the file. */
4710 if (! elf_link_flush_output_syms (&finfo))
4711 return false;
4713 /* Now we know the size of the symtab section. */
4714 off += symtab_hdr->sh_size;
4716 /* Finish up and write out the symbol string table (.strtab)
4717 section. */
4718 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4719 /* sh_name was set in prep_headers. */
4720 symstrtab_hdr->sh_type = SHT_STRTAB;
4721 symstrtab_hdr->sh_flags = 0;
4722 symstrtab_hdr->sh_addr = 0;
4723 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4724 symstrtab_hdr->sh_entsize = 0;
4725 symstrtab_hdr->sh_link = 0;
4726 symstrtab_hdr->sh_info = 0;
4727 /* sh_offset is set just below. */
4728 symstrtab_hdr->sh_addralign = 1;
4730 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4731 elf_tdata (abfd)->next_file_pos = off;
4733 if (bfd_get_symcount (abfd) > 0)
4735 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4736 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4737 return false;
4740 /* Adjust the relocs to have the correct symbol indices. */
4741 for (o = abfd->sections; o != NULL; o = o->next)
4743 if ((o->flags & SEC_RELOC) == 0)
4744 continue;
4746 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4747 elf_section_data (o)->rel_count,
4748 elf_section_data (o)->rel_hashes);
4749 if (elf_section_data (o)->rel_hdr2 != NULL)
4750 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4751 elf_section_data (o)->rel_count2,
4752 (elf_section_data (o)->rel_hashes
4753 + elf_section_data (o)->rel_count));
4755 /* Set the reloc_count field to 0 to prevent write_relocs from
4756 trying to swap the relocs out itself. */
4757 o->reloc_count = 0;
4760 /* If we are linking against a dynamic object, or generating a
4761 shared library, finish up the dynamic linking information. */
4762 if (dynamic)
4764 Elf_External_Dyn *dyncon, *dynconend;
4766 /* Fix up .dynamic entries. */
4767 o = bfd_get_section_by_name (dynobj, ".dynamic");
4768 BFD_ASSERT (o != NULL);
4770 dyncon = (Elf_External_Dyn *) o->contents;
4771 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4772 for (; dyncon < dynconend; dyncon++)
4774 Elf_Internal_Dyn dyn;
4775 const char *name;
4776 unsigned int type;
4778 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4780 switch (dyn.d_tag)
4782 default:
4783 break;
4784 case DT_INIT:
4785 name = info->init_function;
4786 goto get_sym;
4787 case DT_FINI:
4788 name = info->fini_function;
4789 get_sym:
4791 struct elf_link_hash_entry *h;
4793 h = elf_link_hash_lookup (elf_hash_table (info), name,
4794 false, false, true);
4795 if (h != NULL
4796 && (h->root.type == bfd_link_hash_defined
4797 || h->root.type == bfd_link_hash_defweak))
4799 dyn.d_un.d_val = h->root.u.def.value;
4800 o = h->root.u.def.section;
4801 if (o->output_section != NULL)
4802 dyn.d_un.d_val += (o->output_section->vma
4803 + o->output_offset);
4804 else
4806 /* The symbol is imported from another shared
4807 library and does not apply to this one. */
4808 dyn.d_un.d_val = 0;
4811 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4814 break;
4816 case DT_HASH:
4817 name = ".hash";
4818 goto get_vma;
4819 case DT_STRTAB:
4820 name = ".dynstr";
4821 goto get_vma;
4822 case DT_SYMTAB:
4823 name = ".dynsym";
4824 goto get_vma;
4825 case DT_VERDEF:
4826 name = ".gnu.version_d";
4827 goto get_vma;
4828 case DT_VERNEED:
4829 name = ".gnu.version_r";
4830 goto get_vma;
4831 case DT_VERSYM:
4832 name = ".gnu.version";
4833 get_vma:
4834 o = bfd_get_section_by_name (abfd, name);
4835 BFD_ASSERT (o != NULL);
4836 dyn.d_un.d_ptr = o->vma;
4837 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4838 break;
4840 case DT_REL:
4841 case DT_RELA:
4842 case DT_RELSZ:
4843 case DT_RELASZ:
4844 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4845 type = SHT_REL;
4846 else
4847 type = SHT_RELA;
4848 dyn.d_un.d_val = 0;
4849 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4851 Elf_Internal_Shdr *hdr;
4853 hdr = elf_elfsections (abfd)[i];
4854 if (hdr->sh_type == type
4855 && (hdr->sh_flags & SHF_ALLOC) != 0)
4857 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4858 dyn.d_un.d_val += hdr->sh_size;
4859 else
4861 if (dyn.d_un.d_val == 0
4862 || hdr->sh_addr < dyn.d_un.d_val)
4863 dyn.d_un.d_val = hdr->sh_addr;
4867 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4868 break;
4873 /* If we have created any dynamic sections, then output them. */
4874 if (dynobj != NULL)
4876 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4877 goto error_return;
4879 for (o = dynobj->sections; o != NULL; o = o->next)
4881 if ((o->flags & SEC_HAS_CONTENTS) == 0
4882 || o->_raw_size == 0
4883 || o->output_section == bfd_abs_section_ptr)
4884 continue;
4885 if ((o->flags & SEC_LINKER_CREATED) == 0)
4887 /* At this point, we are only interested in sections
4888 created by elf_link_create_dynamic_sections. */
4889 continue;
4891 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4892 != SHT_STRTAB)
4893 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4895 if (! bfd_set_section_contents (abfd, o->output_section,
4896 o->contents, o->output_offset,
4897 o->_raw_size))
4898 goto error_return;
4900 else
4902 file_ptr off;
4904 /* The contents of the .dynstr section are actually in a
4905 stringtab. */
4906 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4907 if (bfd_seek (abfd, off, SEEK_SET) != 0
4908 || ! _bfd_stringtab_emit (abfd,
4909 elf_hash_table (info)->dynstr))
4910 goto error_return;
4915 /* If we have optimized stabs strings, output them. */
4916 if (elf_hash_table (info)->stab_info != NULL)
4918 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4919 goto error_return;
4922 if (finfo.symstrtab != NULL)
4923 _bfd_stringtab_free (finfo.symstrtab);
4924 if (finfo.contents != NULL)
4925 free (finfo.contents);
4926 if (finfo.external_relocs != NULL)
4927 free (finfo.external_relocs);
4928 if (finfo.internal_relocs != NULL)
4929 free (finfo.internal_relocs);
4930 if (finfo.external_syms != NULL)
4931 free (finfo.external_syms);
4932 if (finfo.internal_syms != NULL)
4933 free (finfo.internal_syms);
4934 if (finfo.indices != NULL)
4935 free (finfo.indices);
4936 if (finfo.sections != NULL)
4937 free (finfo.sections);
4938 if (finfo.symbuf != NULL)
4939 free (finfo.symbuf);
4940 for (o = abfd->sections; o != NULL; o = o->next)
4942 if ((o->flags & SEC_RELOC) != 0
4943 && elf_section_data (o)->rel_hashes != NULL)
4944 free (elf_section_data (o)->rel_hashes);
4947 elf_tdata (abfd)->linker = true;
4949 return true;
4951 error_return:
4952 if (finfo.symstrtab != NULL)
4953 _bfd_stringtab_free (finfo.symstrtab);
4954 if (finfo.contents != NULL)
4955 free (finfo.contents);
4956 if (finfo.external_relocs != NULL)
4957 free (finfo.external_relocs);
4958 if (finfo.internal_relocs != NULL)
4959 free (finfo.internal_relocs);
4960 if (finfo.external_syms != NULL)
4961 free (finfo.external_syms);
4962 if (finfo.internal_syms != NULL)
4963 free (finfo.internal_syms);
4964 if (finfo.indices != NULL)
4965 free (finfo.indices);
4966 if (finfo.sections != NULL)
4967 free (finfo.sections);
4968 if (finfo.symbuf != NULL)
4969 free (finfo.symbuf);
4970 for (o = abfd->sections; o != NULL; o = o->next)
4972 if ((o->flags & SEC_RELOC) != 0
4973 && elf_section_data (o)->rel_hashes != NULL)
4974 free (elf_section_data (o)->rel_hashes);
4977 return false;
4980 /* Add a symbol to the output symbol table. */
4982 static boolean
4983 elf_link_output_sym (finfo, name, elfsym, input_sec)
4984 struct elf_final_link_info *finfo;
4985 const char *name;
4986 Elf_Internal_Sym *elfsym;
4987 asection *input_sec;
4989 boolean (*output_symbol_hook) PARAMS ((bfd *,
4990 struct bfd_link_info *info,
4991 const char *,
4992 Elf_Internal_Sym *,
4993 asection *));
4995 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4996 elf_backend_link_output_symbol_hook;
4997 if (output_symbol_hook != NULL)
4999 if (! ((*output_symbol_hook)
5000 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
5001 return false;
5004 if (name == (const char *) NULL || *name == '\0')
5005 elfsym->st_name = 0;
5006 else if (input_sec->flags & SEC_EXCLUDE)
5007 elfsym->st_name = 0;
5008 else
5010 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
5011 name, true,
5012 false);
5013 if (elfsym->st_name == (unsigned long) -1)
5014 return false;
5017 if (finfo->symbuf_count >= finfo->symbuf_size)
5019 if (! elf_link_flush_output_syms (finfo))
5020 return false;
5023 elf_swap_symbol_out (finfo->output_bfd, elfsym,
5024 (PTR) (finfo->symbuf + finfo->symbuf_count));
5025 ++finfo->symbuf_count;
5027 ++ bfd_get_symcount (finfo->output_bfd);
5029 return true;
5032 /* Flush the output symbols to the file. */
5034 static boolean
5035 elf_link_flush_output_syms (finfo)
5036 struct elf_final_link_info *finfo;
5038 if (finfo->symbuf_count > 0)
5040 Elf_Internal_Shdr *symtab;
5042 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
5044 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
5045 SEEK_SET) != 0
5046 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
5047 sizeof (Elf_External_Sym), finfo->output_bfd)
5048 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
5049 return false;
5051 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
5053 finfo->symbuf_count = 0;
5056 return true;
5059 /* Add an external symbol to the symbol table. This is called from
5060 the hash table traversal routine. When generating a shared object,
5061 we go through the symbol table twice. The first time we output
5062 anything that might have been forced to local scope in a version
5063 script. The second time we output the symbols that are still
5064 global symbols. */
5066 static boolean
5067 elf_link_output_extsym (h, data)
5068 struct elf_link_hash_entry *h;
5069 PTR data;
5071 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
5072 struct elf_final_link_info *finfo = eoinfo->finfo;
5073 boolean strip;
5074 Elf_Internal_Sym sym;
5075 asection *input_sec;
5077 /* Decide whether to output this symbol in this pass. */
5078 if (eoinfo->localsyms)
5080 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5081 return true;
5083 else
5085 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5086 return true;
5089 /* If we are not creating a shared library, and this symbol is
5090 referenced by a shared library but is not defined anywhere, then
5091 warn that it is undefined. If we do not do this, the runtime
5092 linker will complain that the symbol is undefined when the
5093 program is run. We don't have to worry about symbols that are
5094 referenced by regular files, because we will already have issued
5095 warnings for them. */
5096 if (! finfo->info->relocateable
5097 && ! finfo->info->allow_shlib_undefined
5098 && ! (finfo->info->shared
5099 && !finfo->info->no_undefined)
5100 && h->root.type == bfd_link_hash_undefined
5101 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
5102 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5104 if (! ((*finfo->info->callbacks->undefined_symbol)
5105 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
5106 (asection *) NULL, 0, true)))
5108 eoinfo->failed = true;
5109 return false;
5113 /* We don't want to output symbols that have never been mentioned by
5114 a regular file, or that we have been told to strip. However, if
5115 h->indx is set to -2, the symbol is used by a reloc and we must
5116 output it. */
5117 if (h->indx == -2)
5118 strip = false;
5119 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
5120 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
5121 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
5122 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5123 strip = true;
5124 else if (finfo->info->strip == strip_all
5125 || (finfo->info->strip == strip_some
5126 && bfd_hash_lookup (finfo->info->keep_hash,
5127 h->root.root.string,
5128 false, false) == NULL))
5129 strip = true;
5130 else
5131 strip = false;
5133 /* If we're stripping it, and it's not a dynamic symbol, there's
5134 nothing else to do unless it is a forced local symbol. */
5135 if (strip
5136 && h->dynindx == -1
5137 && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5138 return true;
5140 sym.st_value = 0;
5141 sym.st_size = h->size;
5142 sym.st_other = h->other;
5143 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5144 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
5145 else if (h->root.type == bfd_link_hash_undefweak
5146 || h->root.type == bfd_link_hash_defweak)
5147 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
5148 else
5149 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
5151 switch (h->root.type)
5153 default:
5154 case bfd_link_hash_new:
5155 abort ();
5156 return false;
5158 case bfd_link_hash_undefined:
5159 input_sec = bfd_und_section_ptr;
5160 sym.st_shndx = SHN_UNDEF;
5161 break;
5163 case bfd_link_hash_undefweak:
5164 input_sec = bfd_und_section_ptr;
5165 sym.st_shndx = SHN_UNDEF;
5166 break;
5168 case bfd_link_hash_defined:
5169 case bfd_link_hash_defweak:
5171 input_sec = h->root.u.def.section;
5172 if (input_sec->output_section != NULL)
5174 sym.st_shndx =
5175 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
5176 input_sec->output_section);
5177 if (sym.st_shndx == (unsigned short) -1)
5179 (*_bfd_error_handler)
5180 (_("%s: could not find output section %s for input section %s"),
5181 bfd_get_filename (finfo->output_bfd),
5182 input_sec->output_section->name,
5183 input_sec->name);
5184 eoinfo->failed = true;
5185 return false;
5188 /* ELF symbols in relocateable files are section relative,
5189 but in nonrelocateable files they are virtual
5190 addresses. */
5191 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5192 if (! finfo->info->relocateable)
5193 sym.st_value += input_sec->output_section->vma;
5195 else
5197 BFD_ASSERT (input_sec->owner == NULL
5198 || (input_sec->owner->flags & DYNAMIC) != 0);
5199 sym.st_shndx = SHN_UNDEF;
5200 input_sec = bfd_und_section_ptr;
5203 break;
5205 case bfd_link_hash_common:
5206 input_sec = h->root.u.c.p->section;
5207 sym.st_shndx = SHN_COMMON;
5208 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5209 break;
5211 case bfd_link_hash_indirect:
5212 /* These symbols are created by symbol versioning. They point
5213 to the decorated version of the name. For example, if the
5214 symbol foo@@GNU_1.2 is the default, which should be used when
5215 foo is used with no version, then we add an indirect symbol
5216 foo which points to foo@@GNU_1.2. We ignore these symbols,
5217 since the indirected symbol is already in the hash table. */
5218 return true;
5220 case bfd_link_hash_warning:
5221 /* We can't represent these symbols in ELF, although a warning
5222 symbol may have come from a .gnu.warning.SYMBOL section. We
5223 just put the target symbol in the hash table. If the target
5224 symbol does not really exist, don't do anything. */
5225 if (h->root.u.i.link->type == bfd_link_hash_new)
5226 return true;
5227 return (elf_link_output_extsym
5228 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5231 /* Give the processor backend a chance to tweak the symbol value,
5232 and also to finish up anything that needs to be done for this
5233 symbol. */
5234 if ((h->dynindx != -1
5235 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5236 && elf_hash_table (finfo->info)->dynamic_sections_created)
5238 struct elf_backend_data *bed;
5240 bed = get_elf_backend_data (finfo->output_bfd);
5241 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5242 (finfo->output_bfd, finfo->info, h, &sym)))
5244 eoinfo->failed = true;
5245 return false;
5249 /* If we are marking the symbol as undefined, and there are no
5250 non-weak references to this symbol from a regular object, then
5251 mark the symbol as weak undefined; if there are non-weak
5252 references, mark the symbol as strong. We can't do this earlier,
5253 because it might not be marked as undefined until the
5254 finish_dynamic_symbol routine gets through with it. */
5255 if (sym.st_shndx == SHN_UNDEF
5256 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5257 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5258 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5260 int bindtype;
5262 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5263 bindtype = STB_GLOBAL;
5264 else
5265 bindtype = STB_WEAK;
5266 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5269 /* If a symbol is not defined locally, we clear the visibility
5270 field. */
5271 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5272 sym.st_other ^= ELF_ST_VISIBILITY(sym.st_other);
5274 /* If this symbol should be put in the .dynsym section, then put it
5275 there now. We have already know the symbol index. We also fill
5276 in the entry in the .hash section. */
5277 if (h->dynindx != -1
5278 && elf_hash_table (finfo->info)->dynamic_sections_created)
5280 size_t bucketcount;
5281 size_t bucket;
5282 size_t hash_entry_size;
5283 bfd_byte *bucketpos;
5284 bfd_vma chain;
5286 sym.st_name = h->dynstr_index;
5288 elf_swap_symbol_out (finfo->output_bfd, &sym,
5289 (PTR) (((Elf_External_Sym *)
5290 finfo->dynsym_sec->contents)
5291 + h->dynindx));
5293 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5294 bucket = h->elf_hash_value % bucketcount;
5295 hash_entry_size
5296 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5297 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5298 + (bucket + 2) * hash_entry_size);
5299 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5300 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5301 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5302 ((bfd_byte *) finfo->hash_sec->contents
5303 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5305 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5307 Elf_Internal_Versym iversym;
5309 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5311 if (h->verinfo.verdef == NULL)
5312 iversym.vs_vers = 0;
5313 else
5314 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5316 else
5318 if (h->verinfo.vertree == NULL)
5319 iversym.vs_vers = 1;
5320 else
5321 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5324 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5325 iversym.vs_vers |= VERSYM_HIDDEN;
5327 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5328 (((Elf_External_Versym *)
5329 finfo->symver_sec->contents)
5330 + h->dynindx));
5334 /* If we're stripping it, then it was just a dynamic symbol, and
5335 there's nothing else to do. */
5336 if (strip)
5337 return true;
5339 h->indx = bfd_get_symcount (finfo->output_bfd);
5341 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5343 eoinfo->failed = true;
5344 return false;
5347 return true;
5350 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5351 originated from the section given by INPUT_REL_HDR) to the
5352 OUTPUT_BFD. */
5354 static void
5355 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5356 internal_relocs)
5357 bfd *output_bfd;
5358 asection *input_section;
5359 Elf_Internal_Shdr *input_rel_hdr;
5360 Elf_Internal_Rela *internal_relocs;
5362 Elf_Internal_Rela *irela;
5363 Elf_Internal_Rela *irelaend;
5364 Elf_Internal_Shdr *output_rel_hdr;
5365 asection *output_section;
5366 unsigned int *rel_countp = NULL;
5367 struct elf_backend_data *bed;
5369 output_section = input_section->output_section;
5370 output_rel_hdr = NULL;
5372 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5373 == input_rel_hdr->sh_entsize)
5375 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5376 rel_countp = &elf_section_data (output_section)->rel_count;
5378 else if (elf_section_data (output_section)->rel_hdr2
5379 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5380 == input_rel_hdr->sh_entsize))
5382 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5383 rel_countp = &elf_section_data (output_section)->rel_count2;
5386 BFD_ASSERT (output_rel_hdr != NULL);
5388 bed = get_elf_backend_data (output_bfd);
5389 irela = internal_relocs;
5390 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5391 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5393 Elf_External_Rel *erel;
5395 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5396 for (; irela < irelaend; irela++, erel++)
5398 Elf_Internal_Rel irel;
5400 irel.r_offset = irela->r_offset;
5401 irel.r_info = irela->r_info;
5402 BFD_ASSERT (irela->r_addend == 0);
5403 if (bed->s->swap_reloc_out)
5404 (*bed->s->swap_reloc_out) (output_bfd, &irel, (PTR) erel);
5405 else
5406 elf_swap_reloc_out (output_bfd, &irel, erel);
5409 else
5411 Elf_External_Rela *erela;
5413 BFD_ASSERT (input_rel_hdr->sh_entsize
5414 == sizeof (Elf_External_Rela));
5415 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5416 for (; irela < irelaend; irela++, erela++)
5417 if (bed->s->swap_reloca_out)
5418 (*bed->s->swap_reloca_out) (output_bfd, irela, (PTR) erela);
5419 else
5420 elf_swap_reloca_out (output_bfd, irela, erela);
5423 /* Bump the counter, so that we know where to add the next set of
5424 relocations. */
5425 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5428 /* Link an input file into the linker output file. This function
5429 handles all the sections and relocations of the input file at once.
5430 This is so that we only have to read the local symbols once, and
5431 don't have to keep them in memory. */
5433 static boolean
5434 elf_link_input_bfd (finfo, input_bfd)
5435 struct elf_final_link_info *finfo;
5436 bfd *input_bfd;
5438 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5439 bfd *, asection *, bfd_byte *,
5440 Elf_Internal_Rela *,
5441 Elf_Internal_Sym *, asection **));
5442 bfd *output_bfd;
5443 Elf_Internal_Shdr *symtab_hdr;
5444 size_t locsymcount;
5445 size_t extsymoff;
5446 Elf_External_Sym *external_syms;
5447 Elf_External_Sym *esym;
5448 Elf_External_Sym *esymend;
5449 Elf_Internal_Sym *isym;
5450 long *pindex;
5451 asection **ppsection;
5452 asection *o;
5453 struct elf_backend_data *bed;
5455 output_bfd = finfo->output_bfd;
5456 bed = get_elf_backend_data (output_bfd);
5457 relocate_section = bed->elf_backend_relocate_section;
5459 /* If this is a dynamic object, we don't want to do anything here:
5460 we don't want the local symbols, and we don't want the section
5461 contents. */
5462 if ((input_bfd->flags & DYNAMIC) != 0)
5463 return true;
5465 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5466 if (elf_bad_symtab (input_bfd))
5468 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5469 extsymoff = 0;
5471 else
5473 locsymcount = symtab_hdr->sh_info;
5474 extsymoff = symtab_hdr->sh_info;
5477 /* Read the local symbols. */
5478 if (symtab_hdr->contents != NULL)
5479 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5480 else if (locsymcount == 0)
5481 external_syms = NULL;
5482 else
5484 external_syms = finfo->external_syms;
5485 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5486 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5487 locsymcount, input_bfd)
5488 != locsymcount * sizeof (Elf_External_Sym)))
5489 return false;
5492 /* Swap in the local symbols and write out the ones which we know
5493 are going into the output file. */
5494 esym = external_syms;
5495 esymend = esym + locsymcount;
5496 isym = finfo->internal_syms;
5497 pindex = finfo->indices;
5498 ppsection = finfo->sections;
5499 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5501 asection *isec;
5502 const char *name;
5503 Elf_Internal_Sym osym;
5505 elf_swap_symbol_in (input_bfd, esym, isym);
5506 *pindex = -1;
5508 if (elf_bad_symtab (input_bfd))
5510 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5512 *ppsection = NULL;
5513 continue;
5517 if (isym->st_shndx == SHN_UNDEF)
5518 isec = bfd_und_section_ptr;
5519 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5520 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5521 else if (isym->st_shndx == SHN_ABS)
5522 isec = bfd_abs_section_ptr;
5523 else if (isym->st_shndx == SHN_COMMON)
5524 isec = bfd_com_section_ptr;
5525 else
5527 /* Who knows? */
5528 isec = NULL;
5531 *ppsection = isec;
5533 /* Don't output the first, undefined, symbol. */
5534 if (esym == external_syms)
5535 continue;
5537 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5539 asection *ksec;
5541 /* Save away all section symbol values. */
5542 if (isec != NULL)
5543 isec->symbol->value = isym->st_value;
5545 /* If this is a discarded link-once section symbol, update
5546 it's value to that of the kept section symbol. The
5547 linker will keep the first of any matching link-once
5548 sections, so we should have already seen it's section
5549 symbol. I trust no-one will have the bright idea of
5550 re-ordering the bfd list... */
5551 if (isec != NULL
5552 && (bfd_get_section_flags (input_bfd, isec) & SEC_LINK_ONCE) != 0
5553 && (ksec = isec->kept_section) != NULL)
5555 isym->st_value = ksec->symbol->value;
5557 /* That put the value right, but the section info is all
5558 wrong. I hope this works. */
5559 isec->output_offset = ksec->output_offset;
5560 isec->output_section = ksec->output_section;
5563 /* We never output section symbols. Instead, we use the
5564 section symbol of the corresponding section in the output
5565 file. */
5566 continue;
5569 /* If we are stripping all symbols, we don't want to output this
5570 one. */
5571 if (finfo->info->strip == strip_all)
5572 continue;
5574 /* If we are discarding all local symbols, we don't want to
5575 output this one. If we are generating a relocateable output
5576 file, then some of the local symbols may be required by
5577 relocs; we output them below as we discover that they are
5578 needed. */
5579 if (finfo->info->discard == discard_all)
5580 continue;
5582 /* If this symbol is defined in a section which we are
5583 discarding, we don't need to keep it, but note that
5584 linker_mark is only reliable for sections that have contents.
5585 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5586 as well as linker_mark. */
5587 if (isym->st_shndx > 0
5588 && isym->st_shndx < SHN_LORESERVE
5589 && isec != NULL
5590 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5591 || (! finfo->info->relocateable
5592 && (isec->flags & SEC_EXCLUDE) != 0)))
5593 continue;
5595 /* Get the name of the symbol. */
5596 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5597 isym->st_name);
5598 if (name == NULL)
5599 return false;
5601 /* See if we are discarding symbols with this name. */
5602 if ((finfo->info->strip == strip_some
5603 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5604 == NULL))
5605 || (finfo->info->discard == discard_l
5606 && bfd_is_local_label_name (input_bfd, name)))
5607 continue;
5609 /* If we get here, we are going to output this symbol. */
5611 osym = *isym;
5613 /* Adjust the section index for the output file. */
5614 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5615 isec->output_section);
5616 if (osym.st_shndx == (unsigned short) -1)
5617 return false;
5619 *pindex = bfd_get_symcount (output_bfd);
5621 /* ELF symbols in relocateable files are section relative, but
5622 in executable files they are virtual addresses. Note that
5623 this code assumes that all ELF sections have an associated
5624 BFD section with a reasonable value for output_offset; below
5625 we assume that they also have a reasonable value for
5626 output_section. Any special sections must be set up to meet
5627 these requirements. */
5628 osym.st_value += isec->output_offset;
5629 if (! finfo->info->relocateable)
5630 osym.st_value += isec->output_section->vma;
5632 if (! elf_link_output_sym (finfo, name, &osym, isec))
5633 return false;
5636 /* Relocate the contents of each section. */
5637 for (o = input_bfd->sections; o != NULL; o = o->next)
5639 bfd_byte *contents;
5641 if (! o->linker_mark)
5643 /* This section was omitted from the link. */
5644 continue;
5647 if ((o->flags & SEC_HAS_CONTENTS) == 0
5648 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5649 continue;
5651 if ((o->flags & SEC_LINKER_CREATED) != 0)
5653 /* Section was created by elf_link_create_dynamic_sections
5654 or somesuch. */
5655 continue;
5658 /* Get the contents of the section. They have been cached by a
5659 relaxation routine. Note that o is a section in an input
5660 file, so the contents field will not have been set by any of
5661 the routines which work on output files. */
5662 if (elf_section_data (o)->this_hdr.contents != NULL)
5663 contents = elf_section_data (o)->this_hdr.contents;
5664 else
5666 contents = finfo->contents;
5667 if (! bfd_get_section_contents (input_bfd, o, contents,
5668 (file_ptr) 0, o->_raw_size))
5669 return false;
5672 if ((o->flags & SEC_RELOC) != 0)
5674 Elf_Internal_Rela *internal_relocs;
5676 /* Get the swapped relocs. */
5677 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5678 (input_bfd, o, finfo->external_relocs,
5679 finfo->internal_relocs, false));
5680 if (internal_relocs == NULL
5681 && o->reloc_count > 0)
5682 return false;
5684 /* Relocate the section by invoking a back end routine.
5686 The back end routine is responsible for adjusting the
5687 section contents as necessary, and (if using Rela relocs
5688 and generating a relocateable output file) adjusting the
5689 reloc addend as necessary.
5691 The back end routine does not have to worry about setting
5692 the reloc address or the reloc symbol index.
5694 The back end routine is given a pointer to the swapped in
5695 internal symbols, and can access the hash table entries
5696 for the external symbols via elf_sym_hashes (input_bfd).
5698 When generating relocateable output, the back end routine
5699 must handle STB_LOCAL/STT_SECTION symbols specially. The
5700 output symbol is going to be a section symbol
5701 corresponding to the output section, which will require
5702 the addend to be adjusted. */
5704 if (! (*relocate_section) (output_bfd, finfo->info,
5705 input_bfd, o, contents,
5706 internal_relocs,
5707 finfo->internal_syms,
5708 finfo->sections))
5709 return false;
5711 if (finfo->info->relocateable || finfo->info->emitrelocations)
5713 Elf_Internal_Rela *irela;
5714 Elf_Internal_Rela *irelaend;
5715 struct elf_link_hash_entry **rel_hash;
5716 Elf_Internal_Shdr *input_rel_hdr;
5718 /* Adjust the reloc addresses and symbol indices. */
5720 irela = internal_relocs;
5721 irelaend =
5722 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5723 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5724 + elf_section_data (o->output_section)->rel_count
5725 + elf_section_data (o->output_section)->rel_count2);
5726 for (; irela < irelaend; irela++, rel_hash++)
5728 unsigned long r_symndx;
5729 Elf_Internal_Sym *isym;
5730 asection *sec;
5732 irela->r_offset += o->output_offset;
5734 /* Relocs in an executable have to be virtual addresses. */
5735 if (finfo->info->emitrelocations)
5736 irela->r_offset += o->output_section->vma;
5738 r_symndx = ELF_R_SYM (irela->r_info);
5740 if (r_symndx == 0)
5741 continue;
5743 if (r_symndx >= locsymcount
5744 || (elf_bad_symtab (input_bfd)
5745 && finfo->sections[r_symndx] == NULL))
5747 struct elf_link_hash_entry *rh;
5748 long indx;
5750 /* This is a reloc against a global symbol. We
5751 have not yet output all the local symbols, so
5752 we do not know the symbol index of any global
5753 symbol. We set the rel_hash entry for this
5754 reloc to point to the global hash table entry
5755 for this symbol. The symbol index is then
5756 set at the end of elf_bfd_final_link. */
5757 indx = r_symndx - extsymoff;
5758 rh = elf_sym_hashes (input_bfd)[indx];
5759 while (rh->root.type == bfd_link_hash_indirect
5760 || rh->root.type == bfd_link_hash_warning)
5761 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5763 /* Setting the index to -2 tells
5764 elf_link_output_extsym that this symbol is
5765 used by a reloc. */
5766 BFD_ASSERT (rh->indx < 0);
5767 rh->indx = -2;
5769 *rel_hash = rh;
5771 continue;
5774 /* This is a reloc against a local symbol. */
5776 *rel_hash = NULL;
5777 isym = finfo->internal_syms + r_symndx;
5778 sec = finfo->sections[r_symndx];
5779 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5781 /* I suppose the backend ought to fill in the
5782 section of any STT_SECTION symbol against a
5783 processor specific section. If we have
5784 discarded a section, the output_section will
5785 be the absolute section. */
5786 if (sec != NULL
5787 && (bfd_is_abs_section (sec)
5788 || (sec->output_section != NULL
5789 && bfd_is_abs_section (sec->output_section))))
5790 r_symndx = 0;
5791 else if (sec == NULL || sec->owner == NULL)
5793 bfd_set_error (bfd_error_bad_value);
5794 return false;
5796 else
5798 r_symndx = sec->output_section->target_index;
5799 BFD_ASSERT (r_symndx != 0);
5802 else
5804 if (finfo->indices[r_symndx] == -1)
5806 unsigned long link;
5807 const char *name;
5808 asection *osec;
5810 if (finfo->info->strip == strip_all)
5812 /* You can't do ld -r -s. */
5813 bfd_set_error (bfd_error_invalid_operation);
5814 return false;
5817 /* This symbol was skipped earlier, but
5818 since it is needed by a reloc, we
5819 must output it now. */
5820 link = symtab_hdr->sh_link;
5821 name = bfd_elf_string_from_elf_section (input_bfd,
5822 link,
5823 isym->st_name);
5824 if (name == NULL)
5825 return false;
5827 osec = sec->output_section;
5828 isym->st_shndx =
5829 _bfd_elf_section_from_bfd_section (output_bfd,
5830 osec);
5831 if (isym->st_shndx == (unsigned short) -1)
5832 return false;
5834 isym->st_value += sec->output_offset;
5835 if (! finfo->info->relocateable)
5836 isym->st_value += osec->vma;
5838 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5840 if (! elf_link_output_sym (finfo, name, isym, sec))
5841 return false;
5844 r_symndx = finfo->indices[r_symndx];
5847 irela->r_info = ELF_R_INFO (r_symndx,
5848 ELF_R_TYPE (irela->r_info));
5851 /* Swap out the relocs. */
5852 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5853 elf_link_output_relocs (output_bfd, o,
5854 input_rel_hdr,
5855 internal_relocs);
5856 internal_relocs
5857 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5858 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5859 if (input_rel_hdr)
5860 elf_link_output_relocs (output_bfd, o,
5861 input_rel_hdr,
5862 internal_relocs);
5866 /* Write out the modified section contents. */
5867 if (elf_section_data (o)->stab_info == NULL)
5869 if (! (o->flags & SEC_EXCLUDE) &&
5870 ! bfd_set_section_contents (output_bfd, o->output_section,
5871 contents, o->output_offset,
5872 (o->_cooked_size != 0
5873 ? o->_cooked_size
5874 : o->_raw_size)))
5875 return false;
5877 else
5879 if (! (_bfd_write_section_stabs
5880 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5881 o, &elf_section_data (o)->stab_info, contents)))
5882 return false;
5886 return true;
5889 /* Generate a reloc when linking an ELF file. This is a reloc
5890 requested by the linker, and does come from any input file. This
5891 is used to build constructor and destructor tables when linking
5892 with -Ur. */
5894 static boolean
5895 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5896 bfd *output_bfd;
5897 struct bfd_link_info *info;
5898 asection *output_section;
5899 struct bfd_link_order *link_order;
5901 reloc_howto_type *howto;
5902 long indx;
5903 bfd_vma offset;
5904 bfd_vma addend;
5905 struct elf_link_hash_entry **rel_hash_ptr;
5906 Elf_Internal_Shdr *rel_hdr;
5907 struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
5909 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5910 if (howto == NULL)
5912 bfd_set_error (bfd_error_bad_value);
5913 return false;
5916 addend = link_order->u.reloc.p->addend;
5918 /* Figure out the symbol index. */
5919 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5920 + elf_section_data (output_section)->rel_count
5921 + elf_section_data (output_section)->rel_count2);
5922 if (link_order->type == bfd_section_reloc_link_order)
5924 indx = link_order->u.reloc.p->u.section->target_index;
5925 BFD_ASSERT (indx != 0);
5926 *rel_hash_ptr = NULL;
5928 else
5930 struct elf_link_hash_entry *h;
5932 /* Treat a reloc against a defined symbol as though it were
5933 actually against the section. */
5934 h = ((struct elf_link_hash_entry *)
5935 bfd_wrapped_link_hash_lookup (output_bfd, info,
5936 link_order->u.reloc.p->u.name,
5937 false, false, true));
5938 if (h != NULL
5939 && (h->root.type == bfd_link_hash_defined
5940 || h->root.type == bfd_link_hash_defweak))
5942 asection *section;
5944 section = h->root.u.def.section;
5945 indx = section->output_section->target_index;
5946 *rel_hash_ptr = NULL;
5947 /* It seems that we ought to add the symbol value to the
5948 addend here, but in practice it has already been added
5949 because it was passed to constructor_callback. */
5950 addend += section->output_section->vma + section->output_offset;
5952 else if (h != NULL)
5954 /* Setting the index to -2 tells elf_link_output_extsym that
5955 this symbol is used by a reloc. */
5956 h->indx = -2;
5957 *rel_hash_ptr = h;
5958 indx = 0;
5960 else
5962 if (! ((*info->callbacks->unattached_reloc)
5963 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5964 (asection *) NULL, (bfd_vma) 0)))
5965 return false;
5966 indx = 0;
5970 /* If this is an inplace reloc, we must write the addend into the
5971 object file. */
5972 if (howto->partial_inplace && addend != 0)
5974 bfd_size_type size;
5975 bfd_reloc_status_type rstat;
5976 bfd_byte *buf;
5977 boolean ok;
5979 size = bfd_get_reloc_size (howto);
5980 buf = (bfd_byte *) bfd_zmalloc (size);
5981 if (buf == (bfd_byte *) NULL)
5982 return false;
5983 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5984 switch (rstat)
5986 case bfd_reloc_ok:
5987 break;
5988 default:
5989 case bfd_reloc_outofrange:
5990 abort ();
5991 case bfd_reloc_overflow:
5992 if (! ((*info->callbacks->reloc_overflow)
5993 (info,
5994 (link_order->type == bfd_section_reloc_link_order
5995 ? bfd_section_name (output_bfd,
5996 link_order->u.reloc.p->u.section)
5997 : link_order->u.reloc.p->u.name),
5998 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5999 (bfd_vma) 0)))
6001 free (buf);
6002 return false;
6004 break;
6006 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
6007 (file_ptr) link_order->offset, size);
6008 free (buf);
6009 if (! ok)
6010 return false;
6013 /* The address of a reloc is relative to the section in a
6014 relocateable file, and is a virtual address in an executable
6015 file. */
6016 offset = link_order->offset;
6017 if (! info->relocateable)
6018 offset += output_section->vma;
6020 rel_hdr = &elf_section_data (output_section)->rel_hdr;
6022 if (rel_hdr->sh_type == SHT_REL)
6024 Elf_Internal_Rel irel;
6025 Elf_External_Rel *erel;
6027 irel.r_offset = offset;
6028 irel.r_info = ELF_R_INFO (indx, howto->type);
6029 erel = ((Elf_External_Rel *) rel_hdr->contents
6030 + elf_section_data (output_section)->rel_count);
6031 if (bed->s->swap_reloc_out)
6032 (*bed->s->swap_reloc_out) (output_bfd, &irel, (bfd_byte *) erel);
6033 else
6034 elf_swap_reloc_out (output_bfd, &irel, erel);
6036 else
6038 Elf_Internal_Rela irela;
6039 Elf_External_Rela *erela;
6041 irela.r_offset = offset;
6042 irela.r_info = ELF_R_INFO (indx, howto->type);
6043 irela.r_addend = addend;
6044 erela = ((Elf_External_Rela *) rel_hdr->contents
6045 + elf_section_data (output_section)->rel_count);
6046 if (bed->s->swap_reloca_out)
6047 (*bed->s->swap_reloca_out) (output_bfd, &irela, (bfd_byte *) erela);
6048 else
6049 elf_swap_reloca_out (output_bfd, &irela, erela);
6052 ++elf_section_data (output_section)->rel_count;
6054 return true;
6058 /* Allocate a pointer to live in a linker created section. */
6060 boolean
6061 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
6062 bfd *abfd;
6063 struct bfd_link_info *info;
6064 elf_linker_section_t *lsect;
6065 struct elf_link_hash_entry *h;
6066 const Elf_Internal_Rela *rel;
6068 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
6069 elf_linker_section_pointers_t *linker_section_ptr;
6070 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
6072 BFD_ASSERT (lsect != NULL);
6074 /* Is this a global symbol? */
6075 if (h != NULL)
6077 /* Has this symbol already been allocated, if so, our work is done */
6078 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6079 rel->r_addend,
6080 lsect->which))
6081 return true;
6083 ptr_linker_section_ptr = &h->linker_section_pointer;
6084 /* Make sure this symbol is output as a dynamic symbol. */
6085 if (h->dynindx == -1)
6087 if (! elf_link_record_dynamic_symbol (info, h))
6088 return false;
6091 if (lsect->rel_section)
6092 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
6095 else /* Allocation of a pointer to a local symbol */
6097 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
6099 /* Allocate a table to hold the local symbols if first time */
6100 if (!ptr)
6102 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
6103 register unsigned int i;
6105 ptr = (elf_linker_section_pointers_t **)
6106 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
6108 if (!ptr)
6109 return false;
6111 elf_local_ptr_offsets (abfd) = ptr;
6112 for (i = 0; i < num_symbols; i++)
6113 ptr[i] = (elf_linker_section_pointers_t *)0;
6116 /* Has this symbol already been allocated, if so, our work is done */
6117 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
6118 rel->r_addend,
6119 lsect->which))
6120 return true;
6122 ptr_linker_section_ptr = &ptr[r_symndx];
6124 if (info->shared)
6126 /* If we are generating a shared object, we need to
6127 output a R_<xxx>_RELATIVE reloc so that the
6128 dynamic linker can adjust this GOT entry. */
6129 BFD_ASSERT (lsect->rel_section != NULL);
6130 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
6134 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
6135 from internal memory. */
6136 BFD_ASSERT (ptr_linker_section_ptr != NULL);
6137 linker_section_ptr = (elf_linker_section_pointers_t *)
6138 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
6140 if (!linker_section_ptr)
6141 return false;
6143 linker_section_ptr->next = *ptr_linker_section_ptr;
6144 linker_section_ptr->addend = rel->r_addend;
6145 linker_section_ptr->which = lsect->which;
6146 linker_section_ptr->written_address_p = false;
6147 *ptr_linker_section_ptr = linker_section_ptr;
6149 #if 0
6150 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
6152 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
6153 lsect->hole_offset += ARCH_SIZE / 8;
6154 lsect->sym_offset += ARCH_SIZE / 8;
6155 if (lsect->sym_hash) /* Bump up symbol value if needed */
6157 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
6158 #ifdef DEBUG
6159 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
6160 lsect->sym_hash->root.root.string,
6161 (long)ARCH_SIZE / 8,
6162 (long)lsect->sym_hash->root.u.def.value);
6163 #endif
6166 else
6167 #endif
6168 linker_section_ptr->offset = lsect->section->_raw_size;
6170 lsect->section->_raw_size += ARCH_SIZE / 8;
6172 #ifdef DEBUG
6173 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
6174 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
6175 #endif
6177 return true;
6181 #if ARCH_SIZE==64
6182 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
6183 #endif
6184 #if ARCH_SIZE==32
6185 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
6186 #endif
6188 /* Fill in the address for a pointer generated in alinker section. */
6190 bfd_vma
6191 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
6192 bfd *output_bfd;
6193 bfd *input_bfd;
6194 struct bfd_link_info *info;
6195 elf_linker_section_t *lsect;
6196 struct elf_link_hash_entry *h;
6197 bfd_vma relocation;
6198 const Elf_Internal_Rela *rel;
6199 int relative_reloc;
6201 elf_linker_section_pointers_t *linker_section_ptr;
6203 BFD_ASSERT (lsect != NULL);
6205 if (h != NULL) /* global symbol */
6207 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6208 rel->r_addend,
6209 lsect->which);
6211 BFD_ASSERT (linker_section_ptr != NULL);
6213 if (! elf_hash_table (info)->dynamic_sections_created
6214 || (info->shared
6215 && info->symbolic
6216 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
6218 /* This is actually a static link, or it is a
6219 -Bsymbolic link and the symbol is defined
6220 locally. We must initialize this entry in the
6221 global section.
6223 When doing a dynamic link, we create a .rela.<xxx>
6224 relocation entry to initialize the value. This
6225 is done in the finish_dynamic_symbol routine. */
6226 if (!linker_section_ptr->written_address_p)
6228 linker_section_ptr->written_address_p = true;
6229 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6230 lsect->section->contents + linker_section_ptr->offset);
6234 else /* local symbol */
6236 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6237 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6238 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6239 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6240 rel->r_addend,
6241 lsect->which);
6243 BFD_ASSERT (linker_section_ptr != NULL);
6245 /* Write out pointer if it hasn't been rewritten out before */
6246 if (!linker_section_ptr->written_address_p)
6248 linker_section_ptr->written_address_p = true;
6249 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6250 lsect->section->contents + linker_section_ptr->offset);
6252 if (info->shared)
6254 asection *srel = lsect->rel_section;
6255 Elf_Internal_Rela outrel;
6257 /* We need to generate a relative reloc for the dynamic linker. */
6258 if (!srel)
6259 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6260 lsect->rel_name);
6262 BFD_ASSERT (srel != NULL);
6264 outrel.r_offset = (lsect->section->output_section->vma
6265 + lsect->section->output_offset
6266 + linker_section_ptr->offset);
6267 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6268 outrel.r_addend = 0;
6269 elf_swap_reloca_out (output_bfd, &outrel,
6270 (((Elf_External_Rela *)
6271 lsect->section->contents)
6272 + elf_section_data (lsect->section)->rel_count));
6273 ++elf_section_data (lsect->section)->rel_count;
6278 relocation = (lsect->section->output_offset
6279 + linker_section_ptr->offset
6280 - lsect->hole_offset
6281 - lsect->sym_offset);
6283 #ifdef DEBUG
6284 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6285 lsect->name, (long)relocation, (long)relocation);
6286 #endif
6288 /* Subtract out the addend, because it will get added back in by the normal
6289 processing. */
6290 return relocation - linker_section_ptr->addend;
6293 /* Garbage collect unused sections. */
6295 static boolean elf_gc_mark
6296 PARAMS ((struct bfd_link_info *info, asection *sec,
6297 asection * (*gc_mark_hook)
6298 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6299 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6301 static boolean elf_gc_sweep
6302 PARAMS ((struct bfd_link_info *info,
6303 boolean (*gc_sweep_hook)
6304 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6305 const Elf_Internal_Rela *relocs))));
6307 static boolean elf_gc_sweep_symbol
6308 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6310 static boolean elf_gc_allocate_got_offsets
6311 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6313 static boolean elf_gc_propagate_vtable_entries_used
6314 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6316 static boolean elf_gc_smash_unused_vtentry_relocs
6317 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6319 /* The mark phase of garbage collection. For a given section, mark
6320 it, and all the sections which define symbols to which it refers. */
6322 static boolean
6323 elf_gc_mark (info, sec, gc_mark_hook)
6324 struct bfd_link_info *info;
6325 asection *sec;
6326 asection * (*gc_mark_hook)
6327 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6328 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6330 boolean ret = true;
6332 sec->gc_mark = 1;
6334 /* Look through the section relocs. */
6336 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6338 Elf_Internal_Rela *relstart, *rel, *relend;
6339 Elf_Internal_Shdr *symtab_hdr;
6340 struct elf_link_hash_entry **sym_hashes;
6341 size_t nlocsyms;
6342 size_t extsymoff;
6343 Elf_External_Sym *locsyms, *freesyms = NULL;
6344 bfd *input_bfd = sec->owner;
6345 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6347 /* GCFIXME: how to arrange so that relocs and symbols are not
6348 reread continually? */
6350 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6351 sym_hashes = elf_sym_hashes (input_bfd);
6353 /* Read the local symbols. */
6354 if (elf_bad_symtab (input_bfd))
6356 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6357 extsymoff = 0;
6359 else
6360 extsymoff = nlocsyms = symtab_hdr->sh_info;
6361 if (symtab_hdr->contents)
6362 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6363 else if (nlocsyms == 0)
6364 locsyms = NULL;
6365 else
6367 locsyms = freesyms =
6368 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6369 if (freesyms == NULL
6370 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6371 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6372 nlocsyms, input_bfd)
6373 != nlocsyms * sizeof (Elf_External_Sym)))
6375 ret = false;
6376 goto out1;
6380 /* Read the relocations. */
6381 relstart = (NAME(_bfd_elf,link_read_relocs)
6382 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6383 info->keep_memory));
6384 if (relstart == NULL)
6386 ret = false;
6387 goto out1;
6389 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6391 for (rel = relstart; rel < relend; rel++)
6393 unsigned long r_symndx;
6394 asection *rsec;
6395 struct elf_link_hash_entry *h;
6396 Elf_Internal_Sym s;
6398 r_symndx = ELF_R_SYM (rel->r_info);
6399 if (r_symndx == 0)
6400 continue;
6402 if (elf_bad_symtab (sec->owner))
6404 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6405 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6406 rsec = (*gc_mark_hook) (sec->owner, info, rel, NULL, &s);
6407 else
6409 h = sym_hashes[r_symndx - extsymoff];
6410 rsec = (*gc_mark_hook) (sec->owner, info, rel, h, NULL);
6413 else if (r_symndx >= nlocsyms)
6415 h = sym_hashes[r_symndx - extsymoff];
6416 rsec = (*gc_mark_hook) (sec->owner, info, rel, h, NULL);
6418 else
6420 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6421 rsec = (*gc_mark_hook) (sec->owner, info, rel, NULL, &s);
6424 if (rsec && !rsec->gc_mark)
6425 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6427 ret = false;
6428 goto out2;
6432 out2:
6433 if (!info->keep_memory)
6434 free (relstart);
6435 out1:
6436 if (freesyms)
6437 free (freesyms);
6440 return ret;
6443 /* The sweep phase of garbage collection. Remove all garbage sections. */
6445 static boolean
6446 elf_gc_sweep (info, gc_sweep_hook)
6447 struct bfd_link_info *info;
6448 boolean (*gc_sweep_hook)
6449 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6450 const Elf_Internal_Rela *relocs));
6452 bfd *sub;
6454 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6456 asection *o;
6458 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6459 continue;
6461 for (o = sub->sections; o != NULL; o = o->next)
6463 /* Keep special sections. Keep .debug sections. */
6464 if ((o->flags & SEC_LINKER_CREATED)
6465 || (o->flags & SEC_DEBUGGING))
6466 o->gc_mark = 1;
6468 if (o->gc_mark)
6469 continue;
6471 /* Skip sweeping sections already excluded. */
6472 if (o->flags & SEC_EXCLUDE)
6473 continue;
6475 /* Since this is early in the link process, it is simple
6476 to remove a section from the output. */
6477 o->flags |= SEC_EXCLUDE;
6479 /* But we also have to update some of the relocation
6480 info we collected before. */
6481 if (gc_sweep_hook
6482 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6484 Elf_Internal_Rela *internal_relocs;
6485 boolean r;
6487 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6488 (o->owner, o, NULL, NULL, info->keep_memory));
6489 if (internal_relocs == NULL)
6490 return false;
6492 r = (*gc_sweep_hook) (o->owner, info, o, internal_relocs);
6494 if (!info->keep_memory)
6495 free (internal_relocs);
6497 if (!r)
6498 return false;
6503 /* Remove the symbols that were in the swept sections from the dynamic
6504 symbol table. GCFIXME: Anyone know how to get them out of the
6505 static symbol table as well? */
6507 int i = 0;
6509 elf_link_hash_traverse (elf_hash_table (info),
6510 elf_gc_sweep_symbol,
6511 (PTR) &i);
6513 elf_hash_table (info)->dynsymcount = i;
6516 return true;
6519 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6521 static boolean
6522 elf_gc_sweep_symbol (h, idxptr)
6523 struct elf_link_hash_entry *h;
6524 PTR idxptr;
6526 int *idx = (int *) idxptr;
6528 if (h->dynindx != -1
6529 && ((h->root.type != bfd_link_hash_defined
6530 && h->root.type != bfd_link_hash_defweak)
6531 || h->root.u.def.section->gc_mark))
6532 h->dynindx = (*idx)++;
6534 return true;
6537 /* Propogate collected vtable information. This is called through
6538 elf_link_hash_traverse. */
6540 static boolean
6541 elf_gc_propagate_vtable_entries_used (h, okp)
6542 struct elf_link_hash_entry *h;
6543 PTR okp;
6545 /* Those that are not vtables. */
6546 if (h->vtable_parent == NULL)
6547 return true;
6549 /* Those vtables that do not have parents, we cannot merge. */
6550 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6551 return true;
6553 /* If we've already been done, exit. */
6554 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6555 return true;
6557 /* Make sure the parent's table is up to date. */
6558 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6560 if (h->vtable_entries_used == NULL)
6562 /* None of this table's entries were referenced. Re-use the
6563 parent's table. */
6564 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6565 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6567 else
6569 size_t n;
6570 boolean *cu, *pu;
6572 /* Or the parent's entries into ours. */
6573 cu = h->vtable_entries_used;
6574 cu[-1] = true;
6575 pu = h->vtable_parent->vtable_entries_used;
6576 if (pu != NULL)
6578 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6579 while (--n != 0)
6581 if (*pu) *cu = true;
6582 pu++, cu++;
6587 return true;
6590 static boolean
6591 elf_gc_smash_unused_vtentry_relocs (h, okp)
6592 struct elf_link_hash_entry *h;
6593 PTR okp;
6595 asection *sec;
6596 bfd_vma hstart, hend;
6597 Elf_Internal_Rela *relstart, *relend, *rel;
6598 struct elf_backend_data *bed;
6600 /* Take care of both those symbols that do not describe vtables as
6601 well as those that are not loaded. */
6602 if (h->vtable_parent == NULL)
6603 return true;
6605 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6606 || h->root.type == bfd_link_hash_defweak);
6608 sec = h->root.u.def.section;
6609 hstart = h->root.u.def.value;
6610 hend = hstart + h->size;
6612 relstart = (NAME(_bfd_elf,link_read_relocs)
6613 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6614 if (!relstart)
6615 return *(boolean *)okp = false;
6616 bed = get_elf_backend_data (sec->owner);
6617 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6619 for (rel = relstart; rel < relend; ++rel)
6620 if (rel->r_offset >= hstart && rel->r_offset < hend)
6622 /* If the entry is in use, do nothing. */
6623 if (h->vtable_entries_used
6624 && (rel->r_offset - hstart) < h->vtable_entries_size)
6626 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6627 if (h->vtable_entries_used[entry])
6628 continue;
6630 /* Otherwise, kill it. */
6631 rel->r_offset = rel->r_info = rel->r_addend = 0;
6634 return true;
6637 /* Do mark and sweep of unused sections. */
6639 boolean
6640 elf_gc_sections (abfd, info)
6641 bfd *abfd;
6642 struct bfd_link_info *info;
6644 boolean ok = true;
6645 bfd *sub;
6646 asection * (*gc_mark_hook)
6647 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6648 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6650 if (!get_elf_backend_data (abfd)->can_gc_sections
6651 || info->relocateable || info->emitrelocations
6652 || elf_hash_table (info)->dynamic_sections_created)
6653 return true;
6655 /* Apply transitive closure to the vtable entry usage info. */
6656 elf_link_hash_traverse (elf_hash_table (info),
6657 elf_gc_propagate_vtable_entries_used,
6658 (PTR) &ok);
6659 if (!ok)
6660 return false;
6662 /* Kill the vtable relocations that were not used. */
6663 elf_link_hash_traverse (elf_hash_table (info),
6664 elf_gc_smash_unused_vtentry_relocs,
6665 (PTR) &ok);
6666 if (!ok)
6667 return false;
6669 /* Grovel through relocs to find out who stays ... */
6671 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6672 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6674 asection *o;
6676 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6677 continue;
6679 for (o = sub->sections; o != NULL; o = o->next)
6681 if (o->flags & SEC_KEEP)
6682 if (!elf_gc_mark (info, o, gc_mark_hook))
6683 return false;
6687 /* ... and mark SEC_EXCLUDE for those that go. */
6688 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6689 return false;
6691 return true;
6694 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6696 boolean
6697 elf_gc_record_vtinherit (abfd, sec, h, offset)
6698 bfd *abfd;
6699 asection *sec;
6700 struct elf_link_hash_entry *h;
6701 bfd_vma offset;
6703 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6704 struct elf_link_hash_entry **search, *child;
6705 bfd_size_type extsymcount;
6707 /* The sh_info field of the symtab header tells us where the
6708 external symbols start. We don't care about the local symbols at
6709 this point. */
6710 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6711 if (!elf_bad_symtab (abfd))
6712 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6714 sym_hashes = elf_sym_hashes (abfd);
6715 sym_hashes_end = sym_hashes + extsymcount;
6717 /* Hunt down the child symbol, which is in this section at the same
6718 offset as the relocation. */
6719 for (search = sym_hashes; search != sym_hashes_end; ++search)
6721 if ((child = *search) != NULL
6722 && (child->root.type == bfd_link_hash_defined
6723 || child->root.type == bfd_link_hash_defweak)
6724 && child->root.u.def.section == sec
6725 && child->root.u.def.value == offset)
6726 goto win;
6729 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6730 bfd_get_filename (abfd), sec->name,
6731 (unsigned long)offset);
6732 bfd_set_error (bfd_error_invalid_operation);
6733 return false;
6735 win:
6736 if (!h)
6738 /* This *should* only be the absolute section. It could potentially
6739 be that someone has defined a non-global vtable though, which
6740 would be bad. It isn't worth paging in the local symbols to be
6741 sure though; that case should simply be handled by the assembler. */
6743 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6745 else
6746 child->vtable_parent = h;
6748 return true;
6751 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6753 boolean
6754 elf_gc_record_vtentry (abfd, sec, h, addend)
6755 bfd *abfd ATTRIBUTE_UNUSED;
6756 asection *sec ATTRIBUTE_UNUSED;
6757 struct elf_link_hash_entry *h;
6758 bfd_vma addend;
6760 if (addend >= h->vtable_entries_size)
6762 size_t size, bytes;
6763 boolean *ptr = h->vtable_entries_used;
6765 /* While the symbol is undefined, we have to be prepared to handle
6766 a zero size. */
6767 if (h->root.type == bfd_link_hash_undefined)
6768 size = addend;
6769 else
6771 size = h->size;
6772 if (size < addend)
6774 /* Oops! We've got a reference past the defined end of
6775 the table. This is probably a bug -- shall we warn? */
6776 size = addend;
6780 /* Allocate one extra entry for use as a "done" flag for the
6781 consolidation pass. */
6782 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6784 if (ptr)
6786 ptr = bfd_realloc (ptr - 1, bytes);
6788 if (ptr != NULL)
6790 size_t oldbytes;
6792 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6793 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6796 else
6797 ptr = bfd_zmalloc (bytes);
6799 if (ptr == NULL)
6800 return false;
6802 /* And arrange for that done flag to be at index -1. */
6803 h->vtable_entries_used = ptr + 1;
6804 h->vtable_entries_size = size;
6807 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6809 return true;
6812 /* And an accompanying bit to work out final got entry offsets once
6813 we're done. Should be called from final_link. */
6815 boolean
6816 elf_gc_common_finalize_got_offsets (abfd, info)
6817 bfd *abfd;
6818 struct bfd_link_info *info;
6820 bfd *i;
6821 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6822 bfd_vma gotoff;
6824 /* The GOT offset is relative to the .got section, but the GOT header is
6825 put into the .got.plt section, if the backend uses it. */
6826 if (bed->want_got_plt)
6827 gotoff = 0;
6828 else
6829 gotoff = bed->got_header_size;
6831 /* Do the local .got entries first. */
6832 for (i = info->input_bfds; i; i = i->link_next)
6834 bfd_signed_vma *local_got;
6835 bfd_size_type j, locsymcount;
6836 Elf_Internal_Shdr *symtab_hdr;
6838 if (bfd_get_flavour (i) != bfd_target_elf_flavour)
6839 continue;
6841 local_got = elf_local_got_refcounts (i);
6842 if (!local_got)
6843 continue;
6845 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6846 if (elf_bad_symtab (i))
6847 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6848 else
6849 locsymcount = symtab_hdr->sh_info;
6851 for (j = 0; j < locsymcount; ++j)
6853 if (local_got[j] > 0)
6855 local_got[j] = gotoff;
6856 gotoff += ARCH_SIZE / 8;
6858 else
6859 local_got[j] = (bfd_vma) -1;
6863 /* Then the global .got entries. .plt refcounts are handled by
6864 adjust_dynamic_symbol */
6865 elf_link_hash_traverse (elf_hash_table (info),
6866 elf_gc_allocate_got_offsets,
6867 (PTR) &gotoff);
6868 return true;
6871 /* We need a special top-level link routine to convert got reference counts
6872 to real got offsets. */
6874 static boolean
6875 elf_gc_allocate_got_offsets (h, offarg)
6876 struct elf_link_hash_entry *h;
6877 PTR offarg;
6879 bfd_vma *off = (bfd_vma *) offarg;
6881 if (h->got.refcount > 0)
6883 h->got.offset = off[0];
6884 off[0] += ARCH_SIZE / 8;
6886 else
6887 h->got.offset = (bfd_vma) -1;
6889 return true;
6892 /* Many folk need no more in the way of final link than this, once
6893 got entry reference counting is enabled. */
6895 boolean
6896 elf_gc_common_final_link (abfd, info)
6897 bfd *abfd;
6898 struct bfd_link_info *info;
6900 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6901 return false;
6903 /* Invoke the regular ELF backend linker to do all the work. */
6904 return elf_bfd_final_link (abfd, info);
6907 /* This function will be called though elf_link_hash_traverse to store
6908 all hash value of the exported symbols in an array. */
6910 static boolean
6911 elf_collect_hash_codes (h, data)
6912 struct elf_link_hash_entry *h;
6913 PTR data;
6915 unsigned long **valuep = (unsigned long **) data;
6916 const char *name;
6917 char *p;
6918 unsigned long ha;
6919 char *alc = NULL;
6921 /* Ignore indirect symbols. These are added by the versioning code. */
6922 if (h->dynindx == -1)
6923 return true;
6925 name = h->root.root.string;
6926 p = strchr (name, ELF_VER_CHR);
6927 if (p != NULL)
6929 alc = bfd_malloc (p - name + 1);
6930 memcpy (alc, name, p - name);
6931 alc[p - name] = '\0';
6932 name = alc;
6935 /* Compute the hash value. */
6936 ha = bfd_elf_hash (name);
6938 /* Store the found hash value in the array given as the argument. */
6939 *(*valuep)++ = ha;
6941 /* And store it in the struct so that we can put it in the hash table
6942 later. */
6943 h->elf_hash_value = ha;
6945 if (alc != NULL)
6946 free (alc);
6948 return true;