2001-03-22 Philip Blundell <philb@gnu.org>
[binutils.git] / bfd / elflink.h
blobd3b44e8831a0d05ced0b68ac17c14d5bc4df97e6
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;
214 /* Add symbols from an ELF archive file to the linker hash table. We
215 don't use _bfd_generic_link_add_archive_symbols because of a
216 problem which arises on UnixWare. The UnixWare libc.so is an
217 archive which includes an entry libc.so.1 which defines a bunch of
218 symbols. The libc.so archive also includes a number of other
219 object files, which also define symbols, some of which are the same
220 as those defined in libc.so.1. Correct linking requires that we
221 consider each object file in turn, and include it if it defines any
222 symbols we need. _bfd_generic_link_add_archive_symbols does not do
223 this; it looks through the list of undefined symbols, and includes
224 any object file which defines them. When this algorithm is used on
225 UnixWare, it winds up pulling in libc.so.1 early and defining a
226 bunch of symbols. This means that some of the other objects in the
227 archive are not included in the link, which is incorrect since they
228 precede libc.so.1 in the archive.
230 Fortunately, ELF archive handling is simpler than that done by
231 _bfd_generic_link_add_archive_symbols, which has to allow for a.out
232 oddities. In ELF, if we find a symbol in the archive map, and the
233 symbol is currently undefined, we know that we must pull in that
234 object file.
236 Unfortunately, we do have to make multiple passes over the symbol
237 table until nothing further is resolved. */
239 static boolean
240 elf_link_add_archive_symbols (abfd, info)
241 bfd *abfd;
242 struct bfd_link_info *info;
244 symindex c;
245 boolean *defined = NULL;
246 boolean *included = NULL;
247 carsym *symdefs;
248 boolean loop;
250 if (! bfd_has_map (abfd))
252 /* An empty archive is a special case. */
253 if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
254 return true;
255 bfd_set_error (bfd_error_no_armap);
256 return false;
259 /* Keep track of all symbols we know to be already defined, and all
260 files we know to be already included. This is to speed up the
261 second and subsequent passes. */
262 c = bfd_ardata (abfd)->symdef_count;
263 if (c == 0)
264 return true;
265 defined = (boolean *) bfd_malloc (c * sizeof (boolean));
266 included = (boolean *) bfd_malloc (c * sizeof (boolean));
267 if (defined == (boolean *) NULL || included == (boolean *) NULL)
268 goto error_return;
269 memset (defined, 0, c * sizeof (boolean));
270 memset (included, 0, c * sizeof (boolean));
272 symdefs = bfd_ardata (abfd)->symdefs;
276 file_ptr last;
277 symindex i;
278 carsym *symdef;
279 carsym *symdefend;
281 loop = false;
282 last = -1;
284 symdef = symdefs;
285 symdefend = symdef + c;
286 for (i = 0; symdef < symdefend; symdef++, i++)
288 struct elf_link_hash_entry *h;
289 bfd *element;
290 struct bfd_link_hash_entry *undefs_tail;
291 symindex mark;
293 if (defined[i] || included[i])
294 continue;
295 if (symdef->file_offset == last)
297 included[i] = true;
298 continue;
301 h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
302 false, false, false);
304 if (h == NULL)
306 char *p, *copy;
308 /* If this is a default version (the name contains @@),
309 look up the symbol again without the version. The
310 effect is that references to the symbol without the
311 version will be matched by the default symbol in the
312 archive. */
314 p = strchr (symdef->name, ELF_VER_CHR);
315 if (p == NULL || p[1] != ELF_VER_CHR)
316 continue;
318 copy = bfd_alloc (abfd, p - symdef->name + 1);
319 if (copy == NULL)
320 goto error_return;
321 memcpy (copy, symdef->name, p - symdef->name);
322 copy[p - symdef->name] = '\0';
324 h = elf_link_hash_lookup (elf_hash_table (info), copy,
325 false, false, false);
327 bfd_release (abfd, copy);
330 if (h == NULL)
331 continue;
333 if (h->root.type == bfd_link_hash_common)
335 /* We currently have a common symbol. The archive map contains
336 a reference to this symbol, so we may want to include it. We
337 only want to include it however, if this archive element
338 contains a definition of the symbol, not just another common
339 declaration of it.
341 Unfortunately some archivers (including GNU ar) will put
342 declarations of common symbols into their archive maps, as
343 well as real definitions, so we cannot just go by the archive
344 map alone. Instead we must read in the element's symbol
345 table and check that to see what kind of symbol definition
346 this is. */
347 if (! elf_link_is_defined_archive_symbol (abfd, symdef))
348 continue;
350 else if (h->root.type != bfd_link_hash_undefined)
352 if (h->root.type != bfd_link_hash_undefweak)
353 defined[i] = true;
354 continue;
357 /* We need to include this archive member. */
358 element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
359 if (element == (bfd *) NULL)
360 goto error_return;
362 if (! bfd_check_format (element, bfd_object))
363 goto error_return;
365 /* Doublecheck that we have not included this object
366 already--it should be impossible, but there may be
367 something wrong with the archive. */
368 if (element->archive_pass != 0)
370 bfd_set_error (bfd_error_bad_value);
371 goto error_return;
373 element->archive_pass = 1;
375 undefs_tail = info->hash->undefs_tail;
377 if (! (*info->callbacks->add_archive_element) (info, element,
378 symdef->name))
379 goto error_return;
380 if (! elf_link_add_object_symbols (element, info))
381 goto error_return;
383 /* If there are any new undefined symbols, we need to make
384 another pass through the archive in order to see whether
385 they can be defined. FIXME: This isn't perfect, because
386 common symbols wind up on undefs_tail and because an
387 undefined symbol which is defined later on in this pass
388 does not require another pass. This isn't a bug, but it
389 does make the code less efficient than it could be. */
390 if (undefs_tail != info->hash->undefs_tail)
391 loop = true;
393 /* Look backward to mark all symbols from this object file
394 which we have already seen in this pass. */
395 mark = i;
398 included[mark] = true;
399 if (mark == 0)
400 break;
401 --mark;
403 while (symdefs[mark].file_offset == symdef->file_offset);
405 /* We mark subsequent symbols from this object file as we go
406 on through the loop. */
407 last = symdef->file_offset;
410 while (loop);
412 free (defined);
413 free (included);
415 return true;
417 error_return:
418 if (defined != (boolean *) NULL)
419 free (defined);
420 if (included != (boolean *) NULL)
421 free (included);
422 return false;
425 /* This function is called when we want to define a new symbol. It
426 handles the various cases which arise when we find a definition in
427 a dynamic object, or when there is already a definition in a
428 dynamic object. The new symbol is described by NAME, SYM, PSEC,
429 and PVALUE. We set SYM_HASH to the hash table entry. We set
430 OVERRIDE if the old symbol is overriding a new definition. We set
431 TYPE_CHANGE_OK if it is OK for the type to change. We set
432 SIZE_CHANGE_OK if it is OK for the size to change. By OK to
433 change, we mean that we shouldn't warn if the type or size does
434 change. DT_NEEDED indicates if it comes from a DT_NEEDED entry of
435 a shared object. */
437 static boolean
438 elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
439 override, type_change_ok, size_change_ok, dt_needed)
440 bfd *abfd;
441 struct bfd_link_info *info;
442 const char *name;
443 Elf_Internal_Sym *sym;
444 asection **psec;
445 bfd_vma *pvalue;
446 struct elf_link_hash_entry **sym_hash;
447 boolean *override;
448 boolean *type_change_ok;
449 boolean *size_change_ok;
450 boolean dt_needed;
452 asection *sec;
453 struct elf_link_hash_entry *h;
454 int bind;
455 bfd *oldbfd;
456 boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
458 *override = false;
460 sec = *psec;
461 bind = ELF_ST_BIND (sym->st_info);
463 if (! bfd_is_und_section (sec))
464 h = elf_link_hash_lookup (elf_hash_table (info), name, true, false, false);
465 else
466 h = ((struct elf_link_hash_entry *)
467 bfd_wrapped_link_hash_lookup (abfd, info, name, true, false, false));
468 if (h == NULL)
469 return false;
470 *sym_hash = h;
472 /* This code is for coping with dynamic objects, and is only useful
473 if we are doing an ELF link. */
474 if (info->hash->creator != abfd->xvec)
475 return true;
477 /* For merging, we only care about real symbols. */
479 while (h->root.type == bfd_link_hash_indirect
480 || h->root.type == bfd_link_hash_warning)
481 h = (struct elf_link_hash_entry *) h->root.u.i.link;
483 /* If we just created the symbol, mark it as being an ELF symbol.
484 Other than that, there is nothing to do--there is no merge issue
485 with a newly defined symbol--so we just return. */
487 if (h->root.type == bfd_link_hash_new)
489 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
490 return true;
493 /* OLDBFD is a BFD associated with the existing symbol. */
495 switch (h->root.type)
497 default:
498 oldbfd = NULL;
499 break;
501 case bfd_link_hash_undefined:
502 case bfd_link_hash_undefweak:
503 oldbfd = h->root.u.undef.abfd;
504 break;
506 case bfd_link_hash_defined:
507 case bfd_link_hash_defweak:
508 oldbfd = h->root.u.def.section->owner;
509 break;
511 case bfd_link_hash_common:
512 oldbfd = h->root.u.c.p->section->owner;
513 break;
516 /* In cases involving weak versioned symbols, we may wind up trying
517 to merge a symbol with itself. Catch that here, to avoid the
518 confusion that results if we try to override a symbol with
519 itself. The additional tests catch cases like
520 _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
521 dynamic object, which we do want to handle here. */
522 if (abfd == oldbfd
523 && ((abfd->flags & DYNAMIC) == 0
524 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))
525 return true;
527 /* NEWDYN and OLDDYN indicate whether the new or old symbol,
528 respectively, is from a dynamic object. */
530 if ((abfd->flags & DYNAMIC) != 0)
531 newdyn = true;
532 else
533 newdyn = false;
535 if (oldbfd != NULL)
536 olddyn = (oldbfd->flags & DYNAMIC) != 0;
537 else
539 asection *hsec;
541 /* This code handles the special SHN_MIPS_{TEXT,DATA} section
542 indices used by MIPS ELF. */
543 switch (h->root.type)
545 default:
546 hsec = NULL;
547 break;
549 case bfd_link_hash_defined:
550 case bfd_link_hash_defweak:
551 hsec = h->root.u.def.section;
552 break;
554 case bfd_link_hash_common:
555 hsec = h->root.u.c.p->section;
556 break;
559 if (hsec == NULL)
560 olddyn = false;
561 else
562 olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0;
565 /* NEWDEF and OLDDEF indicate whether the new or old symbol,
566 respectively, appear to be a definition rather than reference. */
568 if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
569 newdef = false;
570 else
571 newdef = true;
573 if (h->root.type == bfd_link_hash_undefined
574 || h->root.type == bfd_link_hash_undefweak
575 || h->root.type == bfd_link_hash_common)
576 olddef = false;
577 else
578 olddef = true;
580 /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
581 symbol, respectively, appears to be a common symbol in a dynamic
582 object. If a symbol appears in an uninitialized section, and is
583 not weak, and is not a function, then it may be a common symbol
584 which was resolved when the dynamic object was created. We want
585 to treat such symbols specially, because they raise special
586 considerations when setting the symbol size: if the symbol
587 appears as a common symbol in a regular object, and the size in
588 the regular object is larger, we must make sure that we use the
589 larger size. This problematic case can always be avoided in C,
590 but it must be handled correctly when using Fortran shared
591 libraries.
593 Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
594 likewise for OLDDYNCOMMON and OLDDEF.
596 Note that this test is just a heuristic, and that it is quite
597 possible to have an uninitialized symbol in a shared object which
598 is really a definition, rather than a common symbol. This could
599 lead to some minor confusion when the symbol really is a common
600 symbol in some regular object. However, I think it will be
601 harmless. */
603 if (newdyn
604 && newdef
605 && (sec->flags & SEC_ALLOC) != 0
606 && (sec->flags & SEC_LOAD) == 0
607 && sym->st_size > 0
608 && bind != STB_WEAK
609 && ELF_ST_TYPE (sym->st_info) != STT_FUNC)
610 newdyncommon = true;
611 else
612 newdyncommon = false;
614 if (olddyn
615 && olddef
616 && h->root.type == bfd_link_hash_defined
617 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
618 && (h->root.u.def.section->flags & SEC_ALLOC) != 0
619 && (h->root.u.def.section->flags & SEC_LOAD) == 0
620 && h->size > 0
621 && h->type != STT_FUNC)
622 olddyncommon = true;
623 else
624 olddyncommon = false;
626 /* It's OK to change the type if either the existing symbol or the
627 new symbol is weak unless it comes from a DT_NEEDED entry of
628 a shared object, in which case, the DT_NEEDED entry may not be
629 required at the run time. */
631 if ((! dt_needed && h->root.type == bfd_link_hash_defweak)
632 || h->root.type == bfd_link_hash_undefweak
633 || bind == STB_WEAK)
634 *type_change_ok = true;
636 /* It's OK to change the size if either the existing symbol or the
637 new symbol is weak, or if the old symbol is undefined. */
639 if (*type_change_ok
640 || h->root.type == bfd_link_hash_undefined)
641 *size_change_ok = true;
643 /* If both the old and the new symbols look like common symbols in a
644 dynamic object, set the size of the symbol to the larger of the
645 two. */
647 if (olddyncommon
648 && newdyncommon
649 && sym->st_size != h->size)
651 /* Since we think we have two common symbols, issue a multiple
652 common warning if desired. Note that we only warn if the
653 size is different. If the size is the same, we simply let
654 the old symbol override the new one as normally happens with
655 symbols defined in dynamic objects. */
657 if (! ((*info->callbacks->multiple_common)
658 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
659 h->size, abfd, bfd_link_hash_common, sym->st_size)))
660 return false;
662 if (sym->st_size > h->size)
663 h->size = sym->st_size;
665 *size_change_ok = true;
668 /* If we are looking at a dynamic object, and we have found a
669 definition, we need to see if the symbol was already defined by
670 some other object. If so, we want to use the existing
671 definition, and we do not want to report a multiple symbol
672 definition error; we do this by clobbering *PSEC to be
673 bfd_und_section_ptr.
675 We treat a common symbol as a definition if the symbol in the
676 shared library is a function, since common symbols always
677 represent variables; this can cause confusion in principle, but
678 any such confusion would seem to indicate an erroneous program or
679 shared library. We also permit a common symbol in a regular
680 object to override a weak symbol in a shared object.
682 We prefer a non-weak definition in a shared library to a weak
683 definition in the executable unless it comes from a DT_NEEDED
684 entry of a shared object, in which case, the DT_NEEDED entry
685 may not be required at the run time. */
687 if (newdyn
688 && newdef
689 && (olddef
690 || (h->root.type == bfd_link_hash_common
691 && (bind == STB_WEAK
692 || ELF_ST_TYPE (sym->st_info) == STT_FUNC)))
693 && (h->root.type != bfd_link_hash_defweak
694 || dt_needed
695 || bind == STB_WEAK))
697 *override = true;
698 newdef = false;
699 newdyncommon = false;
701 *psec = sec = bfd_und_section_ptr;
702 *size_change_ok = true;
704 /* If we get here when the old symbol is a common symbol, then
705 we are explicitly letting it override a weak symbol or
706 function in a dynamic object, and we don't want to warn about
707 a type change. If the old symbol is a defined symbol, a type
708 change warning may still be appropriate. */
710 if (h->root.type == bfd_link_hash_common)
711 *type_change_ok = true;
714 /* Handle the special case of an old common symbol merging with a
715 new symbol which looks like a common symbol in a shared object.
716 We change *PSEC and *PVALUE to make the new symbol look like a
717 common symbol, and let _bfd_generic_link_add_one_symbol will do
718 the right thing. */
720 if (newdyncommon
721 && h->root.type == bfd_link_hash_common)
723 *override = true;
724 newdef = false;
725 newdyncommon = false;
726 *pvalue = sym->st_size;
727 *psec = sec = bfd_com_section_ptr;
728 *size_change_ok = true;
731 /* If the old symbol is from a dynamic object, and the new symbol is
732 a definition which is not from a dynamic object, then the new
733 symbol overrides the old symbol. Symbols from regular files
734 always take precedence over symbols from dynamic objects, even if
735 they are defined after the dynamic object in the link.
737 As above, we again permit a common symbol in a regular object to
738 override a definition in a shared object if the shared object
739 symbol is a function or is weak.
741 As above, we permit a non-weak definition in a shared object to
742 override a weak definition in a regular object. */
744 if (! newdyn
745 && (newdef
746 || (bfd_is_com_section (sec)
747 && (h->root.type == bfd_link_hash_defweak
748 || h->type == STT_FUNC)))
749 && olddyn
750 && olddef
751 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
752 && (bind != STB_WEAK
753 || h->root.type == bfd_link_hash_defweak))
755 /* Change the hash table entry to undefined, and let
756 _bfd_generic_link_add_one_symbol do the right thing with the
757 new definition. */
759 h->root.type = bfd_link_hash_undefined;
760 h->root.u.undef.abfd = h->root.u.def.section->owner;
761 *size_change_ok = true;
763 olddef = false;
764 olddyncommon = false;
766 /* We again permit a type change when a common symbol may be
767 overriding a function. */
769 if (bfd_is_com_section (sec))
770 *type_change_ok = true;
772 /* This union may have been set to be non-NULL when this symbol
773 was seen in a dynamic object. We must force the union to be
774 NULL, so that it is correct for a regular symbol. */
776 h->verinfo.vertree = NULL;
778 /* In this special case, if H is the target of an indirection,
779 we want the caller to frob with H rather than with the
780 indirect symbol. That will permit the caller to redefine the
781 target of the indirection, rather than the indirect symbol
782 itself. FIXME: This will break the -y option if we store a
783 symbol with a different name. */
784 *sym_hash = h;
787 /* Handle the special case of a new common symbol merging with an
788 old symbol that looks like it might be a common symbol defined in
789 a shared object. Note that we have already handled the case in
790 which a new common symbol should simply override the definition
791 in the shared library. */
793 if (! newdyn
794 && bfd_is_com_section (sec)
795 && olddyncommon)
797 /* It would be best if we could set the hash table entry to a
798 common symbol, but we don't know what to use for the section
799 or the alignment. */
800 if (! ((*info->callbacks->multiple_common)
801 (info, h->root.root.string, oldbfd, bfd_link_hash_common,
802 h->size, abfd, bfd_link_hash_common, sym->st_size)))
803 return false;
805 /* If the predumed common symbol in the dynamic object is
806 larger, pretend that the new symbol has its size. */
808 if (h->size > *pvalue)
809 *pvalue = h->size;
811 /* FIXME: We no longer know the alignment required by the symbol
812 in the dynamic object, so we just wind up using the one from
813 the regular object. */
815 olddef = false;
816 olddyncommon = false;
818 h->root.type = bfd_link_hash_undefined;
819 h->root.u.undef.abfd = h->root.u.def.section->owner;
821 *size_change_ok = true;
822 *type_change_ok = true;
824 h->verinfo.vertree = NULL;
827 /* Handle the special case of a weak definition in a regular object
828 followed by a non-weak definition in a shared object. In this
829 case, we prefer the definition in the shared object unless it
830 comes from a DT_NEEDED entry of a shared object, in which case,
831 the DT_NEEDED entry may not be required at the run time. */
832 if (olddef
833 && ! dt_needed
834 && h->root.type == bfd_link_hash_defweak
835 && newdef
836 && newdyn
837 && bind != STB_WEAK)
839 /* To make this work we have to frob the flags so that the rest
840 of the code does not think we are using the regular
841 definition. */
842 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
843 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
844 else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
845 h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
846 h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR
847 | ELF_LINK_HASH_DEF_DYNAMIC);
849 /* If H is the target of an indirection, we want the caller to
850 use H rather than the indirect symbol. Otherwise if we are
851 defining a new indirect symbol we will wind up attaching it
852 to the entry we are overriding. */
853 *sym_hash = h;
856 /* Handle the special case of a non-weak definition in a shared
857 object followed by a weak definition in a regular object. In
858 this case we prefer to definition in the shared object. To make
859 this work we have to tell the caller to not treat the new symbol
860 as a definition. */
861 if (olddef
862 && olddyn
863 && h->root.type != bfd_link_hash_defweak
864 && newdef
865 && ! newdyn
866 && bind == STB_WEAK)
867 *override = true;
869 return true;
872 /* Add symbols from an ELF object file to the linker hash table. */
874 static boolean
875 elf_link_add_object_symbols (abfd, info)
876 bfd *abfd;
877 struct bfd_link_info *info;
879 boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
880 const Elf_Internal_Sym *,
881 const char **, flagword *,
882 asection **, bfd_vma *));
883 boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
884 asection *, const Elf_Internal_Rela *));
885 boolean collect;
886 Elf_Internal_Shdr *hdr;
887 size_t symcount;
888 size_t extsymcount;
889 size_t extsymoff;
890 Elf_External_Sym *buf = NULL;
891 struct elf_link_hash_entry **sym_hash;
892 boolean dynamic;
893 bfd_byte *dynver = NULL;
894 Elf_External_Versym *extversym = NULL;
895 Elf_External_Versym *ever;
896 Elf_External_Dyn *dynbuf = NULL;
897 struct elf_link_hash_entry *weaks;
898 Elf_External_Sym *esym;
899 Elf_External_Sym *esymend;
900 struct elf_backend_data *bed;
901 boolean dt_needed;
903 bed = get_elf_backend_data (abfd);
904 add_symbol_hook = bed->elf_add_symbol_hook;
905 collect = bed->collect;
907 if ((abfd->flags & DYNAMIC) == 0)
908 dynamic = false;
909 else
911 dynamic = true;
913 /* You can't use -r against a dynamic object. Also, there's no
914 hope of using a dynamic object which does not exactly match
915 the format of the output file. */
916 if (info->relocateable || info->hash->creator != abfd->xvec)
918 bfd_set_error (bfd_error_invalid_operation);
919 goto error_return;
923 /* As a GNU extension, any input sections which are named
924 .gnu.warning.SYMBOL are treated as warning symbols for the given
925 symbol. This differs from .gnu.warning sections, which generate
926 warnings when they are included in an output file. */
927 if (! info->shared)
929 asection *s;
931 for (s = abfd->sections; s != NULL; s = s->next)
933 const char *name;
935 name = bfd_get_section_name (abfd, s);
936 if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
938 char *msg;
939 bfd_size_type sz;
941 name += sizeof ".gnu.warning." - 1;
943 /* If this is a shared object, then look up the symbol
944 in the hash table. If it is there, and it is already
945 been defined, then we will not be using the entry
946 from this shared object, so we don't need to warn.
947 FIXME: If we see the definition in a regular object
948 later on, we will warn, but we shouldn't. The only
949 fix is to keep track of what warnings we are supposed
950 to emit, and then handle them all at the end of the
951 link. */
952 if (dynamic && abfd->xvec == info->hash->creator)
954 struct elf_link_hash_entry *h;
956 h = elf_link_hash_lookup (elf_hash_table (info), name,
957 false, false, true);
959 /* FIXME: What about bfd_link_hash_common? */
960 if (h != NULL
961 && (h->root.type == bfd_link_hash_defined
962 || h->root.type == bfd_link_hash_defweak))
964 /* We don't want to issue this warning. Clobber
965 the section size so that the warning does not
966 get copied into the output file. */
967 s->_raw_size = 0;
968 continue;
972 sz = bfd_section_size (abfd, s);
973 msg = (char *) bfd_alloc (abfd, sz + 1);
974 if (msg == NULL)
975 goto error_return;
977 if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
978 goto error_return;
980 msg[sz] = '\0';
982 if (! (_bfd_generic_link_add_one_symbol
983 (info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
984 false, collect, (struct bfd_link_hash_entry **) NULL)))
985 goto error_return;
987 if (! info->relocateable)
989 /* Clobber the section size so that the warning does
990 not get copied into the output file. */
991 s->_raw_size = 0;
997 /* If this is a dynamic object, we always link against the .dynsym
998 symbol table, not the .symtab symbol table. The dynamic linker
999 will only see the .dynsym symbol table, so there is no reason to
1000 look at .symtab for a dynamic object. */
1002 if (! dynamic || elf_dynsymtab (abfd) == 0)
1003 hdr = &elf_tdata (abfd)->symtab_hdr;
1004 else
1005 hdr = &elf_tdata (abfd)->dynsymtab_hdr;
1007 if (dynamic)
1009 /* Read in any version definitions. */
1011 if (! _bfd_elf_slurp_version_tables (abfd))
1012 goto error_return;
1014 /* Read in the symbol versions, but don't bother to convert them
1015 to internal format. */
1016 if (elf_dynversym (abfd) != 0)
1018 Elf_Internal_Shdr *versymhdr;
1020 versymhdr = &elf_tdata (abfd)->dynversym_hdr;
1021 extversym = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
1022 if (extversym == NULL)
1023 goto error_return;
1024 if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
1025 || (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
1026 != versymhdr->sh_size))
1027 goto error_return;
1031 symcount = hdr->sh_size / sizeof (Elf_External_Sym);
1033 /* The sh_info field of the symtab header tells us where the
1034 external symbols start. We don't care about the local symbols at
1035 this point. */
1036 if (elf_bad_symtab (abfd))
1038 extsymcount = symcount;
1039 extsymoff = 0;
1041 else
1043 extsymcount = symcount - hdr->sh_info;
1044 extsymoff = hdr->sh_info;
1047 buf = ((Elf_External_Sym *)
1048 bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
1049 if (buf == NULL && extsymcount != 0)
1050 goto error_return;
1052 /* We store a pointer to the hash table entry for each external
1053 symbol. */
1054 sym_hash = ((struct elf_link_hash_entry **)
1055 bfd_alloc (abfd,
1056 extsymcount * sizeof (struct elf_link_hash_entry *)));
1057 if (sym_hash == NULL)
1058 goto error_return;
1059 elf_sym_hashes (abfd) = sym_hash;
1061 dt_needed = false;
1063 if (! dynamic)
1065 /* If we are creating a shared library, create all the dynamic
1066 sections immediately. We need to attach them to something,
1067 so we attach them to this BFD, provided it is the right
1068 format. FIXME: If there are no input BFD's of the same
1069 format as the output, we can't make a shared library. */
1070 if (info->shared
1071 && ! elf_hash_table (info)->dynamic_sections_created
1072 && abfd->xvec == info->hash->creator)
1074 if (! elf_link_create_dynamic_sections (abfd, info))
1075 goto error_return;
1078 else
1080 asection *s;
1081 boolean add_needed;
1082 const char *name;
1083 bfd_size_type oldsize;
1084 bfd_size_type strindex;
1086 /* Find the name to use in a DT_NEEDED entry that refers to this
1087 object. If the object has a DT_SONAME entry, we use it.
1088 Otherwise, if the generic linker stuck something in
1089 elf_dt_name, we use that. Otherwise, we just use the file
1090 name. If the generic linker put a null string into
1091 elf_dt_name, we don't make a DT_NEEDED entry at all, even if
1092 there is a DT_SONAME entry. */
1093 add_needed = true;
1094 name = bfd_get_filename (abfd);
1095 if (elf_dt_name (abfd) != NULL)
1097 name = elf_dt_name (abfd);
1098 if (*name == '\0')
1100 if (elf_dt_soname (abfd) != NULL)
1101 dt_needed = true;
1103 add_needed = false;
1106 s = bfd_get_section_by_name (abfd, ".dynamic");
1107 if (s != NULL)
1109 Elf_External_Dyn *extdyn;
1110 Elf_External_Dyn *extdynend;
1111 int elfsec;
1112 unsigned long link;
1113 int rpath;
1114 int runpath;
1116 dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
1117 if (dynbuf == NULL)
1118 goto error_return;
1120 if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
1121 (file_ptr) 0, s->_raw_size))
1122 goto error_return;
1124 elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1125 if (elfsec == -1)
1126 goto error_return;
1127 link = elf_elfsections (abfd)[elfsec]->sh_link;
1130 /* The shared libraries distributed with hpux11 have a bogus
1131 sh_link field for the ".dynamic" section. This code detects
1132 when LINK refers to a section that is not a string table and
1133 tries to find the string table for the ".dynsym" section
1134 instead. */
1135 Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[link];
1136 if (hdr->sh_type != SHT_STRTAB)
1138 asection *s = bfd_get_section_by_name (abfd, ".dynsym");
1139 int elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
1140 if (elfsec == -1)
1141 goto error_return;
1142 link = elf_elfsections (abfd)[elfsec]->sh_link;
1146 extdyn = dynbuf;
1147 extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
1148 rpath = 0;
1149 runpath = 0;
1150 for (; extdyn < extdynend; extdyn++)
1152 Elf_Internal_Dyn dyn;
1154 elf_swap_dyn_in (abfd, extdyn, &dyn);
1155 if (dyn.d_tag == DT_SONAME)
1157 name = bfd_elf_string_from_elf_section (abfd, link,
1158 dyn.d_un.d_val);
1159 if (name == NULL)
1160 goto error_return;
1162 if (dyn.d_tag == DT_NEEDED)
1164 struct bfd_link_needed_list *n, **pn;
1165 char *fnm, *anm;
1167 n = ((struct bfd_link_needed_list *)
1168 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1169 fnm = bfd_elf_string_from_elf_section (abfd, link,
1170 dyn.d_un.d_val);
1171 if (n == NULL || fnm == NULL)
1172 goto error_return;
1173 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1174 if (anm == NULL)
1175 goto error_return;
1176 strcpy (anm, fnm);
1177 n->name = anm;
1178 n->by = abfd;
1179 n->next = NULL;
1180 for (pn = &elf_hash_table (info)->needed;
1181 *pn != NULL;
1182 pn = &(*pn)->next)
1184 *pn = n;
1186 if (dyn.d_tag == DT_RUNPATH)
1188 struct bfd_link_needed_list *n, **pn;
1189 char *fnm, *anm;
1191 /* When we see DT_RPATH before DT_RUNPATH, we have
1192 to clear runpath. Do _NOT_ bfd_release, as that
1193 frees all more recently bfd_alloc'd blocks as
1194 well. */
1195 if (rpath && elf_hash_table (info)->runpath)
1196 elf_hash_table (info)->runpath = NULL;
1198 n = ((struct bfd_link_needed_list *)
1199 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1200 fnm = bfd_elf_string_from_elf_section (abfd, link,
1201 dyn.d_un.d_val);
1202 if (n == NULL || fnm == NULL)
1203 goto error_return;
1204 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1205 if (anm == NULL)
1206 goto error_return;
1207 strcpy (anm, fnm);
1208 n->name = anm;
1209 n->by = abfd;
1210 n->next = NULL;
1211 for (pn = &elf_hash_table (info)->runpath;
1212 *pn != NULL;
1213 pn = &(*pn)->next)
1215 *pn = n;
1216 runpath = 1;
1217 rpath = 0;
1219 /* Ignore DT_RPATH if we have seen DT_RUNPATH. */
1220 if (!runpath && dyn.d_tag == DT_RPATH)
1222 struct bfd_link_needed_list *n, **pn;
1223 char *fnm, *anm;
1225 n = ((struct bfd_link_needed_list *)
1226 bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
1227 fnm = bfd_elf_string_from_elf_section (abfd, link,
1228 dyn.d_un.d_val);
1229 if (n == NULL || fnm == NULL)
1230 goto error_return;
1231 anm = bfd_alloc (abfd, strlen (fnm) + 1);
1232 if (anm == NULL)
1233 goto error_return;
1234 strcpy (anm, fnm);
1235 n->name = anm;
1236 n->by = abfd;
1237 n->next = NULL;
1238 for (pn = &elf_hash_table (info)->runpath;
1239 *pn != NULL;
1240 pn = &(*pn)->next)
1242 *pn = n;
1243 rpath = 1;
1247 free (dynbuf);
1248 dynbuf = NULL;
1251 /* We do not want to include any of the sections in a dynamic
1252 object in the output file. We hack by simply clobbering the
1253 list of sections in the BFD. This could be handled more
1254 cleanly by, say, a new section flag; the existing
1255 SEC_NEVER_LOAD flag is not the one we want, because that one
1256 still implies that the section takes up space in the output
1257 file. */
1258 abfd->sections = NULL;
1259 abfd->section_count = 0;
1261 /* If this is the first dynamic object found in the link, create
1262 the special sections required for dynamic linking. */
1263 if (! elf_hash_table (info)->dynamic_sections_created)
1265 if (! elf_link_create_dynamic_sections (abfd, info))
1266 goto error_return;
1269 if (add_needed)
1271 /* Add a DT_NEEDED entry for this dynamic object. */
1272 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1273 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
1274 true, false);
1275 if (strindex == (bfd_size_type) -1)
1276 goto error_return;
1278 if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1280 asection *sdyn;
1281 Elf_External_Dyn *dyncon, *dynconend;
1283 /* The hash table size did not change, which means that
1284 the dynamic object name was already entered. If we
1285 have already included this dynamic object in the
1286 link, just ignore it. There is no reason to include
1287 a particular dynamic object more than once. */
1288 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1289 ".dynamic");
1290 BFD_ASSERT (sdyn != NULL);
1292 dyncon = (Elf_External_Dyn *) sdyn->contents;
1293 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1294 sdyn->_raw_size);
1295 for (; dyncon < dynconend; dyncon++)
1297 Elf_Internal_Dyn dyn;
1299 elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
1300 &dyn);
1301 if (dyn.d_tag == DT_NEEDED
1302 && dyn.d_un.d_val == strindex)
1304 if (buf != NULL)
1305 free (buf);
1306 if (extversym != NULL)
1307 free (extversym);
1308 return true;
1313 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1314 goto error_return;
1317 /* Save the SONAME, if there is one, because sometimes the
1318 linker emulation code will need to know it. */
1319 if (*name == '\0')
1320 name = bfd_get_filename (abfd);
1321 elf_dt_name (abfd) = name;
1324 if (bfd_seek (abfd,
1325 hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
1326 SEEK_SET) != 0
1327 || (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
1328 != extsymcount * sizeof (Elf_External_Sym)))
1329 goto error_return;
1331 weaks = NULL;
1333 ever = extversym != NULL ? extversym + extsymoff : NULL;
1334 esymend = buf + extsymcount;
1335 for (esym = buf;
1336 esym < esymend;
1337 esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
1339 Elf_Internal_Sym sym;
1340 int bind;
1341 bfd_vma value;
1342 asection *sec;
1343 flagword flags;
1344 const char *name;
1345 struct elf_link_hash_entry *h;
1346 boolean definition;
1347 boolean size_change_ok, type_change_ok;
1348 boolean new_weakdef;
1349 unsigned int old_alignment;
1351 elf_swap_symbol_in (abfd, esym, &sym);
1353 flags = BSF_NO_FLAGS;
1354 sec = NULL;
1355 value = sym.st_value;
1356 *sym_hash = NULL;
1358 bind = ELF_ST_BIND (sym.st_info);
1359 if (bind == STB_LOCAL)
1361 /* This should be impossible, since ELF requires that all
1362 global symbols follow all local symbols, and that sh_info
1363 point to the first global symbol. Unfortunatealy, Irix 5
1364 screws this up. */
1365 continue;
1367 else if (bind == STB_GLOBAL)
1369 if (sym.st_shndx != SHN_UNDEF
1370 && sym.st_shndx != SHN_COMMON)
1371 flags = BSF_GLOBAL;
1373 else if (bind == STB_WEAK)
1374 flags = BSF_WEAK;
1375 else
1377 /* Leave it up to the processor backend. */
1380 if (sym.st_shndx == SHN_UNDEF)
1381 sec = bfd_und_section_ptr;
1382 else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
1384 sec = section_from_elf_index (abfd, sym.st_shndx);
1385 if (sec == NULL)
1386 sec = bfd_abs_section_ptr;
1387 else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
1388 value -= sec->vma;
1390 else if (sym.st_shndx == SHN_ABS)
1391 sec = bfd_abs_section_ptr;
1392 else if (sym.st_shndx == SHN_COMMON)
1394 sec = bfd_com_section_ptr;
1395 /* What ELF calls the size we call the value. What ELF
1396 calls the value we call the alignment. */
1397 value = sym.st_size;
1399 else
1401 /* Leave it up to the processor backend. */
1404 name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
1405 if (name == (const char *) NULL)
1406 goto error_return;
1408 if (add_symbol_hook)
1410 if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
1411 &value))
1412 goto error_return;
1414 /* The hook function sets the name to NULL if this symbol
1415 should be skipped for some reason. */
1416 if (name == (const char *) NULL)
1417 continue;
1420 /* Sanity check that all possibilities were handled. */
1421 if (sec == (asection *) NULL)
1423 bfd_set_error (bfd_error_bad_value);
1424 goto error_return;
1427 if (bfd_is_und_section (sec)
1428 || bfd_is_com_section (sec))
1429 definition = false;
1430 else
1431 definition = true;
1433 size_change_ok = false;
1434 type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
1435 old_alignment = 0;
1436 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1438 Elf_Internal_Versym iver;
1439 unsigned int vernum = 0;
1440 boolean override;
1442 if (ever != NULL)
1444 _bfd_elf_swap_versym_in (abfd, ever, &iver);
1445 vernum = iver.vs_vers & VERSYM_VERSION;
1447 /* If this is a hidden symbol, or if it is not version
1448 1, we append the version name to the symbol name.
1449 However, we do not modify a non-hidden absolute
1450 symbol, because it might be the version symbol
1451 itself. FIXME: What if it isn't? */
1452 if ((iver.vs_vers & VERSYM_HIDDEN) != 0
1453 || (vernum > 1 && ! bfd_is_abs_section (sec)))
1455 const char *verstr;
1456 int namelen, newlen;
1457 char *newname, *p;
1459 if (sym.st_shndx != SHN_UNDEF)
1461 if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
1463 (*_bfd_error_handler)
1464 (_("%s: %s: invalid version %u (max %d)"),
1465 bfd_get_filename (abfd), name, vernum,
1466 elf_tdata (abfd)->dynverdef_hdr.sh_info);
1467 bfd_set_error (bfd_error_bad_value);
1468 goto error_return;
1470 else if (vernum > 1)
1471 verstr =
1472 elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
1473 else
1474 verstr = "";
1476 else
1478 /* We cannot simply test for the number of
1479 entries in the VERNEED section since the
1480 numbers for the needed versions do not start
1481 at 0. */
1482 Elf_Internal_Verneed *t;
1484 verstr = NULL;
1485 for (t = elf_tdata (abfd)->verref;
1486 t != NULL;
1487 t = t->vn_nextref)
1489 Elf_Internal_Vernaux *a;
1491 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
1493 if (a->vna_other == vernum)
1495 verstr = a->vna_nodename;
1496 break;
1499 if (a != NULL)
1500 break;
1502 if (verstr == NULL)
1504 (*_bfd_error_handler)
1505 (_("%s: %s: invalid needed version %d"),
1506 bfd_get_filename (abfd), name, vernum);
1507 bfd_set_error (bfd_error_bad_value);
1508 goto error_return;
1512 namelen = strlen (name);
1513 newlen = namelen + strlen (verstr) + 2;
1514 if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
1515 ++newlen;
1517 newname = (char *) bfd_alloc (abfd, newlen);
1518 if (newname == NULL)
1519 goto error_return;
1520 strcpy (newname, name);
1521 p = newname + namelen;
1522 *p++ = ELF_VER_CHR;
1523 /* If this is a defined non-hidden version symbol,
1524 we add another @ to the name. This indicates the
1525 default version of the symbol. */
1526 if ((iver.vs_vers & VERSYM_HIDDEN) == 0
1527 && sym.st_shndx != SHN_UNDEF)
1528 *p++ = ELF_VER_CHR;
1529 strcpy (p, verstr);
1531 name = newname;
1535 if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
1536 sym_hash, &override, &type_change_ok,
1537 &size_change_ok, dt_needed))
1538 goto error_return;
1540 if (override)
1541 definition = false;
1543 h = *sym_hash;
1544 while (h->root.type == bfd_link_hash_indirect
1545 || h->root.type == bfd_link_hash_warning)
1546 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1548 /* Remember the old alignment if this is a common symbol, so
1549 that we don't reduce the alignment later on. We can't
1550 check later, because _bfd_generic_link_add_one_symbol
1551 will set a default for the alignment which we want to
1552 override. */
1553 if (h->root.type == bfd_link_hash_common)
1554 old_alignment = h->root.u.c.p->alignment_power;
1556 if (elf_tdata (abfd)->verdef != NULL
1557 && ! override
1558 && vernum > 1
1559 && definition)
1560 h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
1563 if (! (_bfd_generic_link_add_one_symbol
1564 (info, abfd, name, flags, sec, value, (const char *) NULL,
1565 false, collect, (struct bfd_link_hash_entry **) sym_hash)))
1566 goto error_return;
1568 h = *sym_hash;
1569 while (h->root.type == bfd_link_hash_indirect
1570 || h->root.type == bfd_link_hash_warning)
1571 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1572 *sym_hash = h;
1574 new_weakdef = false;
1575 if (dynamic
1576 && definition
1577 && (flags & BSF_WEAK) != 0
1578 && ELF_ST_TYPE (sym.st_info) != STT_FUNC
1579 && info->hash->creator->flavour == bfd_target_elf_flavour
1580 && h->weakdef == NULL)
1582 /* Keep a list of all weak defined non function symbols from
1583 a dynamic object, using the weakdef field. Later in this
1584 function we will set the weakdef field to the correct
1585 value. We only put non-function symbols from dynamic
1586 objects on this list, because that happens to be the only
1587 time we need to know the normal symbol corresponding to a
1588 weak symbol, and the information is time consuming to
1589 figure out. If the weakdef field is not already NULL,
1590 then this symbol was already defined by some previous
1591 dynamic object, and we will be using that previous
1592 definition anyhow. */
1594 h->weakdef = weaks;
1595 weaks = h;
1596 new_weakdef = true;
1599 /* Set the alignment of a common symbol. */
1600 if (sym.st_shndx == SHN_COMMON
1601 && h->root.type == bfd_link_hash_common)
1603 unsigned int align;
1605 align = bfd_log2 (sym.st_value);
1606 if (align > old_alignment
1607 /* Permit an alignment power of zero if an alignment of one
1608 is specified and no other alignments have been specified. */
1609 || (sym.st_value == 1 && old_alignment == 0))
1610 h->root.u.c.p->alignment_power = align;
1613 if (info->hash->creator->flavour == bfd_target_elf_flavour)
1615 int old_flags;
1616 boolean dynsym;
1617 int new_flag;
1619 /* Remember the symbol size and type. */
1620 if (sym.st_size != 0
1621 && (definition || h->size == 0))
1623 if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
1624 (*_bfd_error_handler)
1625 (_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
1626 name, (unsigned long) h->size, (unsigned long) sym.st_size,
1627 bfd_get_filename (abfd));
1629 h->size = sym.st_size;
1632 /* If this is a common symbol, then we always want H->SIZE
1633 to be the size of the common symbol. The code just above
1634 won't fix the size if a common symbol becomes larger. We
1635 don't warn about a size change here, because that is
1636 covered by --warn-common. */
1637 if (h->root.type == bfd_link_hash_common)
1638 h->size = h->root.u.c.size;
1640 if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
1641 && (definition || h->type == STT_NOTYPE))
1643 if (h->type != STT_NOTYPE
1644 && h->type != ELF_ST_TYPE (sym.st_info)
1645 && ! type_change_ok)
1646 (*_bfd_error_handler)
1647 (_("Warning: type of symbol `%s' changed from %d to %d in %s"),
1648 name, h->type, ELF_ST_TYPE (sym.st_info),
1649 bfd_get_filename (abfd));
1651 h->type = ELF_ST_TYPE (sym.st_info);
1654 /* If st_other has a processor-specific meaning, specific code
1655 might be needed here. */
1656 if (sym.st_other != 0)
1658 /* Combine visibilities, using the most constraining one. */
1659 unsigned char hvis = ELF_ST_VISIBILITY (h->other);
1660 unsigned char symvis = ELF_ST_VISIBILITY (sym.st_other);
1662 if (symvis && (hvis > symvis || hvis == 0))
1663 h->other = sym.st_other;
1665 /* If neither has visibility, use the st_other of the
1666 definition. This is an arbitrary choice, since the
1667 other bits have no general meaning. */
1668 if (!symvis && !hvis
1669 && (definition || h->other == 0))
1670 h->other = sym.st_other;
1673 /* Set a flag in the hash table entry indicating the type of
1674 reference or definition we just found. Keep a count of
1675 the number of dynamic symbols we find. A dynamic symbol
1676 is one which is referenced or defined by both a regular
1677 object and a shared object. */
1678 old_flags = h->elf_link_hash_flags;
1679 dynsym = false;
1680 if (! dynamic)
1682 if (! definition)
1684 new_flag = ELF_LINK_HASH_REF_REGULAR;
1685 if (bind != STB_WEAK)
1686 new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
1688 else
1689 new_flag = ELF_LINK_HASH_DEF_REGULAR;
1690 if (info->shared
1691 || (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
1692 | ELF_LINK_HASH_REF_DYNAMIC)) != 0)
1693 dynsym = true;
1695 else
1697 if (! definition)
1698 new_flag = ELF_LINK_HASH_REF_DYNAMIC;
1699 else
1700 new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
1701 if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
1702 | ELF_LINK_HASH_REF_REGULAR)) != 0
1703 || (h->weakdef != NULL
1704 && ! new_weakdef
1705 && h->weakdef->dynindx != -1))
1706 dynsym = true;
1709 h->elf_link_hash_flags |= new_flag;
1711 /* If this symbol has a version, and it is the default
1712 version, we create an indirect symbol from the default
1713 name to the fully decorated name. This will cause
1714 external references which do not specify a version to be
1715 bound to this version of the symbol. */
1716 if (definition || h->root.type == bfd_link_hash_common)
1718 char *p;
1720 p = strchr (name, ELF_VER_CHR);
1721 if (p != NULL && p[1] == ELF_VER_CHR)
1723 char *shortname;
1724 struct elf_link_hash_entry *hi;
1725 boolean override;
1727 shortname = bfd_hash_allocate (&info->hash->table,
1728 p - name + 1);
1729 if (shortname == NULL)
1730 goto error_return;
1731 strncpy (shortname, name, p - name);
1732 shortname[p - name] = '\0';
1734 /* We are going to create a new symbol. Merge it
1735 with any existing symbol with this name. For the
1736 purposes of the merge, act as though we were
1737 defining the symbol we just defined, although we
1738 actually going to define an indirect symbol. */
1739 type_change_ok = false;
1740 size_change_ok = false;
1741 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1742 &value, &hi, &override,
1743 &type_change_ok,
1744 &size_change_ok, dt_needed))
1745 goto error_return;
1747 if (! override)
1749 if (! (_bfd_generic_link_add_one_symbol
1750 (info, abfd, shortname, BSF_INDIRECT,
1751 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1752 collect, (struct bfd_link_hash_entry **) &hi)))
1753 goto error_return;
1755 else
1757 /* In this case the symbol named SHORTNAME is
1758 overriding the indirect symbol we want to
1759 add. We were planning on making SHORTNAME an
1760 indirect symbol referring to NAME. SHORTNAME
1761 is the name without a version. NAME is the
1762 fully versioned name, and it is the default
1763 version.
1765 Overriding means that we already saw a
1766 definition for the symbol SHORTNAME in a
1767 regular object, and it is overriding the
1768 symbol defined in the dynamic object.
1770 When this happens, we actually want to change
1771 NAME, the symbol we just added, to refer to
1772 SHORTNAME. This will cause references to
1773 NAME in the shared object to become
1774 references to SHORTNAME in the regular
1775 object. This is what we expect when we
1776 override a function in a shared object: that
1777 the references in the shared object will be
1778 mapped to the definition in the regular
1779 object. */
1781 while (hi->root.type == bfd_link_hash_indirect
1782 || hi->root.type == bfd_link_hash_warning)
1783 hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
1785 h->root.type = bfd_link_hash_indirect;
1786 h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
1787 if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
1789 h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
1790 hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
1791 if (hi->elf_link_hash_flags
1792 & (ELF_LINK_HASH_REF_REGULAR
1793 | ELF_LINK_HASH_DEF_REGULAR))
1795 if (! _bfd_elf_link_record_dynamic_symbol (info,
1796 hi))
1797 goto error_return;
1801 /* Now set HI to H, so that the following code
1802 will set the other fields correctly. */
1803 hi = h;
1806 /* If there is a duplicate definition somewhere,
1807 then HI may not point to an indirect symbol. We
1808 will have reported an error to the user in that
1809 case. */
1811 if (hi->root.type == bfd_link_hash_indirect)
1813 struct elf_link_hash_entry *ht;
1815 /* If the symbol became indirect, then we assume
1816 that we have not seen a definition before. */
1817 BFD_ASSERT ((hi->elf_link_hash_flags
1818 & (ELF_LINK_HASH_DEF_DYNAMIC
1819 | ELF_LINK_HASH_DEF_REGULAR))
1820 == 0);
1822 ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
1823 (*bed->elf_backend_copy_indirect_symbol) (ht, hi);
1825 /* See if the new flags lead us to realize that
1826 the symbol must be dynamic. */
1827 if (! dynsym)
1829 if (! dynamic)
1831 if (info->shared
1832 || ((hi->elf_link_hash_flags
1833 & ELF_LINK_HASH_REF_DYNAMIC)
1834 != 0))
1835 dynsym = true;
1837 else
1839 if ((hi->elf_link_hash_flags
1840 & ELF_LINK_HASH_REF_REGULAR) != 0)
1841 dynsym = true;
1846 /* We also need to define an indirection from the
1847 nondefault version of the symbol. */
1849 shortname = bfd_hash_allocate (&info->hash->table,
1850 strlen (name));
1851 if (shortname == NULL)
1852 goto error_return;
1853 strncpy (shortname, name, p - name);
1854 strcpy (shortname + (p - name), p + 1);
1856 /* Once again, merge with any existing symbol. */
1857 type_change_ok = false;
1858 size_change_ok = false;
1859 if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
1860 &value, &hi, &override,
1861 &type_change_ok,
1862 &size_change_ok, dt_needed))
1863 goto error_return;
1865 if (override)
1867 /* Here SHORTNAME is a versioned name, so we
1868 don't expect to see the type of override we
1869 do in the case above. */
1870 (*_bfd_error_handler)
1871 (_("%s: warning: unexpected redefinition of `%s'"),
1872 bfd_get_filename (abfd), shortname);
1874 else
1876 if (! (_bfd_generic_link_add_one_symbol
1877 (info, abfd, shortname, BSF_INDIRECT,
1878 bfd_ind_section_ptr, (bfd_vma) 0, name, false,
1879 collect, (struct bfd_link_hash_entry **) &hi)))
1880 goto error_return;
1882 /* If there is a duplicate definition somewhere,
1883 then HI may not point to an indirect symbol.
1884 We will have reported an error to the user in
1885 that case. */
1887 if (hi->root.type == bfd_link_hash_indirect)
1889 /* If the symbol became indirect, then we
1890 assume that we have not seen a definition
1891 before. */
1892 BFD_ASSERT ((hi->elf_link_hash_flags
1893 & (ELF_LINK_HASH_DEF_DYNAMIC
1894 | ELF_LINK_HASH_DEF_REGULAR))
1895 == 0);
1897 (*bed->elf_backend_copy_indirect_symbol) (h, hi);
1899 /* See if the new flags lead us to realize
1900 that the symbol must be dynamic. */
1901 if (! dynsym)
1903 if (! dynamic)
1905 if (info->shared
1906 || ((hi->elf_link_hash_flags
1907 & ELF_LINK_HASH_REF_DYNAMIC)
1908 != 0))
1909 dynsym = true;
1911 else
1913 if ((hi->elf_link_hash_flags
1914 & ELF_LINK_HASH_REF_REGULAR) != 0)
1915 dynsym = true;
1923 if (dynsym && h->dynindx == -1)
1925 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
1926 goto error_return;
1927 if (h->weakdef != NULL
1928 && ! new_weakdef
1929 && h->weakdef->dynindx == -1)
1931 if (! _bfd_elf_link_record_dynamic_symbol (info,
1932 h->weakdef))
1933 goto error_return;
1936 else if (dynsym && h->dynindx != -1)
1937 /* If the symbol already has a dynamic index, but
1938 visibility says it should not be visible, turn it into
1939 a local symbol. */
1940 switch (ELF_ST_VISIBILITY (h->other))
1942 case STV_INTERNAL:
1943 case STV_HIDDEN:
1944 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
1945 (*bed->elf_backend_hide_symbol) (info, h);
1946 break;
1949 if (dt_needed && definition
1950 && (h->elf_link_hash_flags
1951 & ELF_LINK_HASH_REF_REGULAR) != 0)
1953 bfd_size_type oldsize;
1954 bfd_size_type strindex;
1956 /* The symbol from a DT_NEEDED object is referenced from
1957 the regular object to create a dynamic executable. We
1958 have to make sure there is a DT_NEEDED entry for it. */
1960 dt_needed = false;
1961 oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
1962 strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
1963 elf_dt_soname (abfd),
1964 true, false);
1965 if (strindex == (bfd_size_type) -1)
1966 goto error_return;
1968 if (oldsize
1969 == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
1971 asection *sdyn;
1972 Elf_External_Dyn *dyncon, *dynconend;
1974 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
1975 ".dynamic");
1976 BFD_ASSERT (sdyn != NULL);
1978 dyncon = (Elf_External_Dyn *) sdyn->contents;
1979 dynconend = (Elf_External_Dyn *) (sdyn->contents +
1980 sdyn->_raw_size);
1981 for (; dyncon < dynconend; dyncon++)
1983 Elf_Internal_Dyn dyn;
1985 elf_swap_dyn_in (elf_hash_table (info)->dynobj,
1986 dyncon, &dyn);
1987 BFD_ASSERT (dyn.d_tag != DT_NEEDED ||
1988 dyn.d_un.d_val != strindex);
1992 if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
1993 goto error_return;
1998 /* Now set the weakdefs field correctly for all the weak defined
1999 symbols we found. The only way to do this is to search all the
2000 symbols. Since we only need the information for non functions in
2001 dynamic objects, that's the only time we actually put anything on
2002 the list WEAKS. We need this information so that if a regular
2003 object refers to a symbol defined weakly in a dynamic object, the
2004 real symbol in the dynamic object is also put in the dynamic
2005 symbols; we also must arrange for both symbols to point to the
2006 same memory location. We could handle the general case of symbol
2007 aliasing, but a general symbol alias can only be generated in
2008 assembler code, handling it correctly would be very time
2009 consuming, and other ELF linkers don't handle general aliasing
2010 either. */
2011 while (weaks != NULL)
2013 struct elf_link_hash_entry *hlook;
2014 asection *slook;
2015 bfd_vma vlook;
2016 struct elf_link_hash_entry **hpp;
2017 struct elf_link_hash_entry **hppend;
2019 hlook = weaks;
2020 weaks = hlook->weakdef;
2021 hlook->weakdef = NULL;
2023 BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
2024 || hlook->root.type == bfd_link_hash_defweak
2025 || hlook->root.type == bfd_link_hash_common
2026 || hlook->root.type == bfd_link_hash_indirect);
2027 slook = hlook->root.u.def.section;
2028 vlook = hlook->root.u.def.value;
2030 hpp = elf_sym_hashes (abfd);
2031 hppend = hpp + extsymcount;
2032 for (; hpp < hppend; hpp++)
2034 struct elf_link_hash_entry *h;
2036 h = *hpp;
2037 if (h != NULL && h != hlook
2038 && h->root.type == bfd_link_hash_defined
2039 && h->root.u.def.section == slook
2040 && h->root.u.def.value == vlook)
2042 hlook->weakdef = h;
2044 /* If the weak definition is in the list of dynamic
2045 symbols, make sure the real definition is put there
2046 as well. */
2047 if (hlook->dynindx != -1
2048 && h->dynindx == -1)
2050 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2051 goto error_return;
2054 /* If the real definition is in the list of dynamic
2055 symbols, make sure the weak definition is put there
2056 as well. If we don't do this, then the dynamic
2057 loader might not merge the entries for the real
2058 definition and the weak definition. */
2059 if (h->dynindx != -1
2060 && hlook->dynindx == -1)
2062 if (! _bfd_elf_link_record_dynamic_symbol (info, hlook))
2063 goto error_return;
2066 break;
2071 if (buf != NULL)
2073 free (buf);
2074 buf = NULL;
2077 if (extversym != NULL)
2079 free (extversym);
2080 extversym = NULL;
2083 /* If this object is the same format as the output object, and it is
2084 not a shared library, then let the backend look through the
2085 relocs.
2087 This is required to build global offset table entries and to
2088 arrange for dynamic relocs. It is not required for the
2089 particular common case of linking non PIC code, even when linking
2090 against shared libraries, but unfortunately there is no way of
2091 knowing whether an object file has been compiled PIC or not.
2092 Looking through the relocs is not particularly time consuming.
2093 The problem is that we must either (1) keep the relocs in memory,
2094 which causes the linker to require additional runtime memory or
2095 (2) read the relocs twice from the input file, which wastes time.
2096 This would be a good case for using mmap.
2098 I have no idea how to handle linking PIC code into a file of a
2099 different format. It probably can't be done. */
2100 check_relocs = get_elf_backend_data (abfd)->check_relocs;
2101 if (! dynamic
2102 && abfd->xvec == info->hash->creator
2103 && check_relocs != NULL)
2105 asection *o;
2107 for (o = abfd->sections; o != NULL; o = o->next)
2109 Elf_Internal_Rela *internal_relocs;
2110 boolean ok;
2112 if ((o->flags & SEC_RELOC) == 0
2113 || o->reloc_count == 0
2114 || ((info->strip == strip_all || info->strip == strip_debugger)
2115 && (o->flags & SEC_DEBUGGING) != 0)
2116 || bfd_is_abs_section (o->output_section))
2117 continue;
2119 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
2120 (abfd, o, (PTR) NULL,
2121 (Elf_Internal_Rela *) NULL,
2122 info->keep_memory));
2123 if (internal_relocs == NULL)
2124 goto error_return;
2126 ok = (*check_relocs) (abfd, info, o, internal_relocs);
2128 if (! info->keep_memory)
2129 free (internal_relocs);
2131 if (! ok)
2132 goto error_return;
2136 /* If this is a non-traditional, non-relocateable link, try to
2137 optimize the handling of the .stab/.stabstr sections. */
2138 if (! dynamic
2139 && ! info->relocateable
2140 && ! info->traditional_format
2141 && info->hash->creator->flavour == bfd_target_elf_flavour
2142 && (info->strip != strip_all && info->strip != strip_debugger))
2144 asection *stab, *stabstr;
2146 stab = bfd_get_section_by_name (abfd, ".stab");
2147 if (stab != NULL)
2149 stabstr = bfd_get_section_by_name (abfd, ".stabstr");
2151 if (stabstr != NULL)
2153 struct bfd_elf_section_data *secdata;
2155 secdata = elf_section_data (stab);
2156 if (! _bfd_link_section_stabs (abfd,
2157 &elf_hash_table (info)->stab_info,
2158 stab, stabstr,
2159 &secdata->stab_info))
2160 goto error_return;
2165 return true;
2167 error_return:
2168 if (buf != NULL)
2169 free (buf);
2170 if (dynbuf != NULL)
2171 free (dynbuf);
2172 if (dynver != NULL)
2173 free (dynver);
2174 if (extversym != NULL)
2175 free (extversym);
2176 return false;
2179 /* Create some sections which will be filled in with dynamic linking
2180 information. ABFD is an input file which requires dynamic sections
2181 to be created. The dynamic sections take up virtual memory space
2182 when the final executable is run, so we need to create them before
2183 addresses are assigned to the output sections. We work out the
2184 actual contents and size of these sections later. */
2186 boolean
2187 elf_link_create_dynamic_sections (abfd, info)
2188 bfd *abfd;
2189 struct bfd_link_info *info;
2191 flagword flags;
2192 register asection *s;
2193 struct elf_link_hash_entry *h;
2194 struct elf_backend_data *bed;
2196 if (elf_hash_table (info)->dynamic_sections_created)
2197 return true;
2199 /* Make sure that all dynamic sections use the same input BFD. */
2200 if (elf_hash_table (info)->dynobj == NULL)
2201 elf_hash_table (info)->dynobj = abfd;
2202 else
2203 abfd = elf_hash_table (info)->dynobj;
2205 /* Note that we set the SEC_IN_MEMORY flag for all of these
2206 sections. */
2207 flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
2208 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2210 /* A dynamically linked executable has a .interp section, but a
2211 shared library does not. */
2212 if (! info->shared)
2214 s = bfd_make_section (abfd, ".interp");
2215 if (s == NULL
2216 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2217 return false;
2220 /* Create sections to hold version informations. These are removed
2221 if they are not needed. */
2222 s = bfd_make_section (abfd, ".gnu.version_d");
2223 if (s == NULL
2224 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2225 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2226 return false;
2228 s = bfd_make_section (abfd, ".gnu.version");
2229 if (s == NULL
2230 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2231 || ! bfd_set_section_alignment (abfd, s, 1))
2232 return false;
2234 s = bfd_make_section (abfd, ".gnu.version_r");
2235 if (s == NULL
2236 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2237 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2238 return false;
2240 s = bfd_make_section (abfd, ".dynsym");
2241 if (s == NULL
2242 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2243 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2244 return false;
2246 s = bfd_make_section (abfd, ".dynstr");
2247 if (s == NULL
2248 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
2249 return false;
2251 /* Create a strtab to hold the dynamic symbol names. */
2252 if (elf_hash_table (info)->dynstr == NULL)
2254 elf_hash_table (info)->dynstr = elf_stringtab_init ();
2255 if (elf_hash_table (info)->dynstr == NULL)
2256 return false;
2259 s = bfd_make_section (abfd, ".dynamic");
2260 if (s == NULL
2261 || ! bfd_set_section_flags (abfd, s, flags)
2262 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2263 return false;
2265 /* The special symbol _DYNAMIC is always set to the start of the
2266 .dynamic section. This call occurs before we have processed the
2267 symbols for any dynamic object, so we don't have to worry about
2268 overriding a dynamic definition. We could set _DYNAMIC in a
2269 linker script, but we only want to define it if we are, in fact,
2270 creating a .dynamic section. We don't want to define it if there
2271 is no .dynamic section, since on some ELF platforms the start up
2272 code examines it to decide how to initialize the process. */
2273 h = NULL;
2274 if (! (_bfd_generic_link_add_one_symbol
2275 (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
2276 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
2277 (struct bfd_link_hash_entry **) &h)))
2278 return false;
2279 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2280 h->type = STT_OBJECT;
2282 if (info->shared
2283 && ! _bfd_elf_link_record_dynamic_symbol (info, h))
2284 return false;
2286 bed = get_elf_backend_data (abfd);
2288 s = bfd_make_section (abfd, ".hash");
2289 if (s == NULL
2290 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
2291 || ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
2292 return false;
2293 elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
2295 /* Let the backend create the rest of the sections. This lets the
2296 backend set the right flags. The backend will normally create
2297 the .got and .plt sections. */
2298 if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
2299 return false;
2301 elf_hash_table (info)->dynamic_sections_created = true;
2303 return true;
2306 /* Add an entry to the .dynamic table. */
2308 boolean
2309 elf_add_dynamic_entry (info, tag, val)
2310 struct bfd_link_info *info;
2311 bfd_vma tag;
2312 bfd_vma val;
2314 Elf_Internal_Dyn dyn;
2315 bfd *dynobj;
2316 asection *s;
2317 size_t newsize;
2318 bfd_byte *newcontents;
2320 dynobj = elf_hash_table (info)->dynobj;
2322 s = bfd_get_section_by_name (dynobj, ".dynamic");
2323 BFD_ASSERT (s != NULL);
2325 newsize = s->_raw_size + sizeof (Elf_External_Dyn);
2326 newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
2327 if (newcontents == NULL)
2328 return false;
2330 dyn.d_tag = tag;
2331 dyn.d_un.d_val = val;
2332 elf_swap_dyn_out (dynobj, &dyn,
2333 (Elf_External_Dyn *) (newcontents + s->_raw_size));
2335 s->_raw_size = newsize;
2336 s->contents = newcontents;
2338 return true;
2341 /* Record a new local dynamic symbol. */
2343 boolean
2344 elf_link_record_local_dynamic_symbol (info, input_bfd, input_indx)
2345 struct bfd_link_info *info;
2346 bfd *input_bfd;
2347 long input_indx;
2349 struct elf_link_local_dynamic_entry *entry;
2350 struct elf_link_hash_table *eht;
2351 struct bfd_strtab_hash *dynstr;
2352 Elf_External_Sym esym;
2353 unsigned long dynstr_index;
2354 char *name;
2356 /* See if the entry exists already. */
2357 for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
2358 if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
2359 return true;
2361 entry = (struct elf_link_local_dynamic_entry *)
2362 bfd_alloc (input_bfd, sizeof (*entry));
2363 if (entry == NULL)
2364 return false;
2366 /* Go find the symbol, so that we can find it's name. */
2367 if (bfd_seek (input_bfd,
2368 (elf_tdata (input_bfd)->symtab_hdr.sh_offset
2369 + input_indx * sizeof (Elf_External_Sym)),
2370 SEEK_SET) != 0
2371 || (bfd_read (&esym, sizeof (Elf_External_Sym), 1, input_bfd)
2372 != sizeof (Elf_External_Sym)))
2373 return false;
2374 elf_swap_symbol_in (input_bfd, &esym, &entry->isym);
2376 name = (bfd_elf_string_from_elf_section
2377 (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
2378 entry->isym.st_name));
2380 dynstr = elf_hash_table (info)->dynstr;
2381 if (dynstr == NULL)
2383 /* Create a strtab to hold the dynamic symbol names. */
2384 elf_hash_table (info)->dynstr = dynstr = _bfd_elf_stringtab_init ();
2385 if (dynstr == NULL)
2386 return false;
2389 dynstr_index = _bfd_stringtab_add (dynstr, name, true, false);
2390 if (dynstr_index == (unsigned long) -1)
2391 return false;
2392 entry->isym.st_name = dynstr_index;
2394 eht = elf_hash_table (info);
2396 entry->next = eht->dynlocal;
2397 eht->dynlocal = entry;
2398 entry->input_bfd = input_bfd;
2399 entry->input_indx = input_indx;
2400 eht->dynsymcount++;
2402 /* Whatever binding the symbol had before, it's now local. */
2403 entry->isym.st_info
2404 = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
2406 /* The dynindx will be set at the end of size_dynamic_sections. */
2408 return true;
2411 /* Read and swap the relocs from the section indicated by SHDR. This
2412 may be either a REL or a RELA section. The relocations are
2413 translated into RELA relocations and stored in INTERNAL_RELOCS,
2414 which should have already been allocated to contain enough space.
2415 The EXTERNAL_RELOCS are a buffer where the external form of the
2416 relocations should be stored.
2418 Returns false if something goes wrong. */
2420 static boolean
2421 elf_link_read_relocs_from_section (abfd, shdr, external_relocs,
2422 internal_relocs)
2423 bfd *abfd;
2424 Elf_Internal_Shdr *shdr;
2425 PTR external_relocs;
2426 Elf_Internal_Rela *internal_relocs;
2428 struct elf_backend_data *bed;
2430 /* If there aren't any relocations, that's OK. */
2431 if (!shdr)
2432 return true;
2434 /* Position ourselves at the start of the section. */
2435 if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
2436 return false;
2438 /* Read the relocations. */
2439 if (bfd_read (external_relocs, 1, shdr->sh_size, abfd)
2440 != shdr->sh_size)
2441 return false;
2443 bed = get_elf_backend_data (abfd);
2445 /* Convert the external relocations to the internal format. */
2446 if (shdr->sh_entsize == sizeof (Elf_External_Rel))
2448 Elf_External_Rel *erel;
2449 Elf_External_Rel *erelend;
2450 Elf_Internal_Rela *irela;
2451 Elf_Internal_Rel *irel;
2453 erel = (Elf_External_Rel *) external_relocs;
2454 erelend = erel + shdr->sh_size / shdr->sh_entsize;
2455 irela = internal_relocs;
2456 irel = bfd_alloc (abfd, (bed->s->int_rels_per_ext_rel
2457 * sizeof (Elf_Internal_Rel)));
2458 for (; erel < erelend; erel++, irela += bed->s->int_rels_per_ext_rel)
2460 unsigned char i;
2462 if (bed->s->swap_reloc_in)
2463 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, irel);
2464 else
2465 elf_swap_reloc_in (abfd, erel, irel);
2467 for (i = 0; i < bed->s->int_rels_per_ext_rel; ++i)
2469 irela[i].r_offset = irel[i].r_offset;
2470 irela[i].r_info = irel[i].r_info;
2471 irela[i].r_addend = 0;
2475 else
2477 Elf_External_Rela *erela;
2478 Elf_External_Rela *erelaend;
2479 Elf_Internal_Rela *irela;
2481 BFD_ASSERT (shdr->sh_entsize == sizeof (Elf_External_Rela));
2483 erela = (Elf_External_Rela *) external_relocs;
2484 erelaend = erela + shdr->sh_size / shdr->sh_entsize;
2485 irela = internal_relocs;
2486 for (; erela < erelaend; erela++, irela += bed->s->int_rels_per_ext_rel)
2488 if (bed->s->swap_reloca_in)
2489 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, irela);
2490 else
2491 elf_swap_reloca_in (abfd, erela, irela);
2495 return true;
2498 /* Read and swap the relocs for a section O. They may have been
2499 cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
2500 not NULL, they are used as buffers to read into. They are known to
2501 be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
2502 the return value is allocated using either malloc or bfd_alloc,
2503 according to the KEEP_MEMORY argument. If O has two relocation
2504 sections (both REL and RELA relocations), then the REL_HDR
2505 relocations will appear first in INTERNAL_RELOCS, followed by the
2506 REL_HDR2 relocations. */
2508 Elf_Internal_Rela *
2509 NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
2510 keep_memory)
2511 bfd *abfd;
2512 asection *o;
2513 PTR external_relocs;
2514 Elf_Internal_Rela *internal_relocs;
2515 boolean keep_memory;
2517 Elf_Internal_Shdr *rel_hdr;
2518 PTR alloc1 = NULL;
2519 Elf_Internal_Rela *alloc2 = NULL;
2520 struct elf_backend_data *bed = get_elf_backend_data (abfd);
2522 if (elf_section_data (o)->relocs != NULL)
2523 return elf_section_data (o)->relocs;
2525 if (o->reloc_count == 0)
2526 return NULL;
2528 rel_hdr = &elf_section_data (o)->rel_hdr;
2530 if (internal_relocs == NULL)
2532 size_t size;
2534 size = (o->reloc_count * bed->s->int_rels_per_ext_rel
2535 * sizeof (Elf_Internal_Rela));
2536 if (keep_memory)
2537 internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
2538 else
2539 internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
2540 if (internal_relocs == NULL)
2541 goto error_return;
2544 if (external_relocs == NULL)
2546 size_t size = (size_t) rel_hdr->sh_size;
2548 if (elf_section_data (o)->rel_hdr2)
2549 size += (size_t) elf_section_data (o)->rel_hdr2->sh_size;
2550 alloc1 = (PTR) bfd_malloc (size);
2551 if (alloc1 == NULL)
2552 goto error_return;
2553 external_relocs = alloc1;
2556 if (!elf_link_read_relocs_from_section (abfd, rel_hdr,
2557 external_relocs,
2558 internal_relocs))
2559 goto error_return;
2560 if (!elf_link_read_relocs_from_section
2561 (abfd,
2562 elf_section_data (o)->rel_hdr2,
2563 ((bfd_byte *) external_relocs) + rel_hdr->sh_size,
2564 internal_relocs + (rel_hdr->sh_size / rel_hdr->sh_entsize
2565 * bed->s->int_rels_per_ext_rel)))
2566 goto error_return;
2568 /* Cache the results for next time, if we can. */
2569 if (keep_memory)
2570 elf_section_data (o)->relocs = internal_relocs;
2572 if (alloc1 != NULL)
2573 free (alloc1);
2575 /* Don't free alloc2, since if it was allocated we are passing it
2576 back (under the name of internal_relocs). */
2578 return internal_relocs;
2580 error_return:
2581 if (alloc1 != NULL)
2582 free (alloc1);
2583 if (alloc2 != NULL)
2584 free (alloc2);
2585 return NULL;
2588 /* Record an assignment to a symbol made by a linker script. We need
2589 this in case some dynamic object refers to this symbol. */
2591 /*ARGSUSED*/
2592 boolean
2593 NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
2594 bfd *output_bfd ATTRIBUTE_UNUSED;
2595 struct bfd_link_info *info;
2596 const char *name;
2597 boolean provide;
2599 struct elf_link_hash_entry *h;
2601 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2602 return true;
2604 h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
2605 if (h == NULL)
2606 return false;
2608 if (h->root.type == bfd_link_hash_new)
2609 h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
2611 /* If this symbol is being provided by the linker script, and it is
2612 currently defined by a dynamic object, but not by a regular
2613 object, then mark it as undefined so that the generic linker will
2614 force the correct value. */
2615 if (provide
2616 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2617 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2618 h->root.type = bfd_link_hash_undefined;
2620 /* If this symbol is not being provided by the linker script, and it is
2621 currently defined by a dynamic object, but not by a regular object,
2622 then clear out any version information because the symbol will not be
2623 associated with the dynamic object any more. */
2624 if (!provide
2625 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2626 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2627 h->verinfo.verdef = NULL;
2629 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
2631 /* When possible, keep the original type of the symbol */
2632 if (h->type == STT_NOTYPE)
2633 h->type = STT_OBJECT;
2635 if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
2636 | ELF_LINK_HASH_REF_DYNAMIC)) != 0
2637 || info->shared)
2638 && h->dynindx == -1)
2640 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
2641 return false;
2643 /* If this is a weak defined symbol, and we know a corresponding
2644 real symbol from the same dynamic object, make sure the real
2645 symbol is also made into a dynamic symbol. */
2646 if (h->weakdef != NULL
2647 && h->weakdef->dynindx == -1)
2649 if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
2650 return false;
2654 return true;
2657 /* This structure is used to pass information to
2658 elf_link_assign_sym_version. */
2660 struct elf_assign_sym_version_info
2662 /* Output BFD. */
2663 bfd *output_bfd;
2664 /* General link information. */
2665 struct bfd_link_info *info;
2666 /* Version tree. */
2667 struct bfd_elf_version_tree *verdefs;
2668 /* Whether we are exporting all dynamic symbols. */
2669 boolean export_dynamic;
2670 /* Whether we had a failure. */
2671 boolean failed;
2674 /* This structure is used to pass information to
2675 elf_link_find_version_dependencies. */
2677 struct elf_find_verdep_info
2679 /* Output BFD. */
2680 bfd *output_bfd;
2681 /* General link information. */
2682 struct bfd_link_info *info;
2683 /* The number of dependencies. */
2684 unsigned int vers;
2685 /* Whether we had a failure. */
2686 boolean failed;
2689 /* Array used to determine the number of hash table buckets to use
2690 based on the number of symbols there are. If there are fewer than
2691 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
2692 fewer than 37 we use 17 buckets, and so forth. We never use more
2693 than 32771 buckets. */
2695 static const size_t elf_buckets[] =
2697 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
2698 16411, 32771, 0
2701 /* Compute bucket count for hashing table. We do not use a static set
2702 of possible tables sizes anymore. Instead we determine for all
2703 possible reasonable sizes of the table the outcome (i.e., the
2704 number of collisions etc) and choose the best solution. The
2705 weighting functions are not too simple to allow the table to grow
2706 without bounds. Instead one of the weighting factors is the size.
2707 Therefore the result is always a good payoff between few collisions
2708 (= short chain lengths) and table size. */
2709 static size_t
2710 compute_bucket_count (info)
2711 struct bfd_link_info *info;
2713 size_t dynsymcount = elf_hash_table (info)->dynsymcount;
2714 size_t best_size = 0;
2715 unsigned long int *hashcodes;
2716 unsigned long int *hashcodesp;
2717 unsigned long int i;
2719 /* Compute the hash values for all exported symbols. At the same
2720 time store the values in an array so that we could use them for
2721 optimizations. */
2722 hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
2723 * sizeof (unsigned long int));
2724 if (hashcodes == NULL)
2725 return 0;
2726 hashcodesp = hashcodes;
2728 /* Put all hash values in HASHCODES. */
2729 elf_link_hash_traverse (elf_hash_table (info),
2730 elf_collect_hash_codes, &hashcodesp);
2732 /* We have a problem here. The following code to optimize the table
2733 size requires an integer type with more the 32 bits. If
2734 BFD_HOST_U_64_BIT is set we know about such a type. */
2735 #ifdef BFD_HOST_U_64_BIT
2736 if (info->optimize == true)
2738 unsigned long int nsyms = hashcodesp - hashcodes;
2739 size_t minsize;
2740 size_t maxsize;
2741 BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
2742 unsigned long int *counts ;
2744 /* Possible optimization parameters: if we have NSYMS symbols we say
2745 that the hashing table must at least have NSYMS/4 and at most
2746 2*NSYMS buckets. */
2747 minsize = nsyms / 4;
2748 if (minsize == 0)
2749 minsize = 1;
2750 best_size = maxsize = nsyms * 2;
2752 /* Create array where we count the collisions in. We must use bfd_malloc
2753 since the size could be large. */
2754 counts = (unsigned long int *) bfd_malloc (maxsize
2755 * sizeof (unsigned long int));
2756 if (counts == NULL)
2758 free (hashcodes);
2759 return 0;
2762 /* Compute the "optimal" size for the hash table. The criteria is a
2763 minimal chain length. The minor criteria is (of course) the size
2764 of the table. */
2765 for (i = minsize; i < maxsize; ++i)
2767 /* Walk through the array of hashcodes and count the collisions. */
2768 BFD_HOST_U_64_BIT max;
2769 unsigned long int j;
2770 unsigned long int fact;
2772 memset (counts, '\0', i * sizeof (unsigned long int));
2774 /* Determine how often each hash bucket is used. */
2775 for (j = 0; j < nsyms; ++j)
2776 ++counts[hashcodes[j] % i];
2778 /* For the weight function we need some information about the
2779 pagesize on the target. This is information need not be 100%
2780 accurate. Since this information is not available (so far) we
2781 define it here to a reasonable default value. If it is crucial
2782 to have a better value some day simply define this value. */
2783 # ifndef BFD_TARGET_PAGESIZE
2784 # define BFD_TARGET_PAGESIZE (4096)
2785 # endif
2787 /* We in any case need 2 + NSYMS entries for the size values and
2788 the chains. */
2789 max = (2 + nsyms) * (ARCH_SIZE / 8);
2791 # if 1
2792 /* Variant 1: optimize for short chains. We add the squares
2793 of all the chain lengths (which favous many small chain
2794 over a few long chains). */
2795 for (j = 0; j < i; ++j)
2796 max += counts[j] * counts[j];
2798 /* This adds penalties for the overall size of the table. */
2799 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2800 max *= fact * fact;
2801 # else
2802 /* Variant 2: Optimize a lot more for small table. Here we
2803 also add squares of the size but we also add penalties for
2804 empty slots (the +1 term). */
2805 for (j = 0; j < i; ++j)
2806 max += (1 + counts[j]) * (1 + counts[j]);
2808 /* The overall size of the table is considered, but not as
2809 strong as in variant 1, where it is squared. */
2810 fact = i / (BFD_TARGET_PAGESIZE / (ARCH_SIZE / 8)) + 1;
2811 max *= fact;
2812 # endif
2814 /* Compare with current best results. */
2815 if (max < best_chlen)
2817 best_chlen = max;
2818 best_size = i;
2822 free (counts);
2824 else
2825 #endif /* defined (BFD_HOST_U_64_BIT) */
2827 /* This is the fallback solution if no 64bit type is available or if we
2828 are not supposed to spend much time on optimizations. We select the
2829 bucket count using a fixed set of numbers. */
2830 for (i = 0; elf_buckets[i] != 0; i++)
2832 best_size = elf_buckets[i];
2833 if (dynsymcount < elf_buckets[i + 1])
2834 break;
2838 /* Free the arrays we needed. */
2839 free (hashcodes);
2841 return best_size;
2844 /* Set up the sizes and contents of the ELF dynamic sections. This is
2845 called by the ELF linker emulation before_allocation routine. We
2846 must set the sizes of the sections before the linker sets the
2847 addresses of the various sections. */
2849 boolean
2850 NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
2851 export_dynamic, filter_shlib,
2852 auxiliary_filters, info, sinterpptr,
2853 verdefs)
2854 bfd *output_bfd;
2855 const char *soname;
2856 const char *rpath;
2857 boolean export_dynamic;
2858 const char *filter_shlib;
2859 const char * const *auxiliary_filters;
2860 struct bfd_link_info *info;
2861 asection **sinterpptr;
2862 struct bfd_elf_version_tree *verdefs;
2864 bfd_size_type soname_indx;
2865 bfd *dynobj;
2866 struct elf_backend_data *bed;
2867 struct elf_assign_sym_version_info asvinfo;
2869 *sinterpptr = NULL;
2871 soname_indx = (bfd_size_type) -1;
2873 if (info->hash->creator->flavour != bfd_target_elf_flavour)
2874 return true;
2876 /* The backend may have to create some sections regardless of whether
2877 we're dynamic or not. */
2878 bed = get_elf_backend_data (output_bfd);
2879 if (bed->elf_backend_always_size_sections
2880 && ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
2881 return false;
2883 dynobj = elf_hash_table (info)->dynobj;
2885 /* If there were no dynamic objects in the link, there is nothing to
2886 do here. */
2887 if (dynobj == NULL)
2888 return true;
2890 if (elf_hash_table (info)->dynamic_sections_created)
2892 struct elf_info_failed eif;
2893 struct elf_link_hash_entry *h;
2894 asection *dynstr;
2896 *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
2897 BFD_ASSERT (*sinterpptr != NULL || info->shared);
2899 if (soname != NULL)
2901 soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2902 soname, true, true);
2903 if (soname_indx == (bfd_size_type) -1
2904 || ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
2905 return false;
2908 if (info->symbolic)
2910 if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
2911 return false;
2912 info->flags |= DF_SYMBOLIC;
2915 if (rpath != NULL)
2917 bfd_size_type indx;
2919 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
2920 true, true);
2921 if (indx == (bfd_size_type) -1
2922 || ! elf_add_dynamic_entry (info, DT_RPATH, indx)
2923 || (info->new_dtags
2924 && ! elf_add_dynamic_entry (info, DT_RUNPATH, indx)))
2925 return false;
2928 if (filter_shlib != NULL)
2930 bfd_size_type indx;
2932 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2933 filter_shlib, true, true);
2934 if (indx == (bfd_size_type) -1
2935 || ! elf_add_dynamic_entry (info, DT_FILTER, indx))
2936 return false;
2939 if (auxiliary_filters != NULL)
2941 const char * const *p;
2943 for (p = auxiliary_filters; *p != NULL; p++)
2945 bfd_size_type indx;
2947 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
2948 *p, true, true);
2949 if (indx == (bfd_size_type) -1
2950 || ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
2951 return false;
2955 /* If we are supposed to export all symbols into the dynamic symbol
2956 table (this is not the normal case), then do so. */
2957 if (export_dynamic)
2959 struct elf_info_failed eif;
2961 eif.failed = false;
2962 eif.info = info;
2963 elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
2964 (PTR) &eif);
2965 if (eif.failed)
2966 return false;
2969 /* Attach all the symbols to their version information. */
2970 asvinfo.output_bfd = output_bfd;
2971 asvinfo.info = info;
2972 asvinfo.verdefs = verdefs;
2973 asvinfo.export_dynamic = export_dynamic;
2974 asvinfo.failed = false;
2976 elf_link_hash_traverse (elf_hash_table (info),
2977 elf_link_assign_sym_version,
2978 (PTR) &asvinfo);
2979 if (asvinfo.failed)
2980 return false;
2982 /* Find all symbols which were defined in a dynamic object and make
2983 the backend pick a reasonable value for them. */
2984 eif.failed = false;
2985 eif.info = info;
2986 elf_link_hash_traverse (elf_hash_table (info),
2987 elf_adjust_dynamic_symbol,
2988 (PTR) &eif);
2989 if (eif.failed)
2990 return false;
2992 /* Add some entries to the .dynamic section. We fill in some of the
2993 values later, in elf_bfd_final_link, but we must add the entries
2994 now so that we know the final size of the .dynamic section. */
2996 /* If there are initialization and/or finalization functions to
2997 call then add the corresponding DT_INIT/DT_FINI entries. */
2998 h = (info->init_function
2999 ? elf_link_hash_lookup (elf_hash_table (info),
3000 info->init_function, false,
3001 false, false)
3002 : NULL);
3003 if (h != NULL
3004 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
3005 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
3007 if (! elf_add_dynamic_entry (info, DT_INIT, 0))
3008 return false;
3010 h = (info->fini_function
3011 ? elf_link_hash_lookup (elf_hash_table (info),
3012 info->fini_function, false,
3013 false, false)
3014 : NULL);
3015 if (h != NULL
3016 && (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
3017 | ELF_LINK_HASH_DEF_REGULAR)) != 0)
3019 if (! elf_add_dynamic_entry (info, DT_FINI, 0))
3020 return false;
3023 dynstr = bfd_get_section_by_name (dynobj, ".dynstr");
3024 /* If .dynstr is excluded from the link, we don't want any of
3025 these tags. Strictly, we should be checking each section
3026 individually; This quick check covers for the case where
3027 someone does a /DISCARD/ : { *(*) }. */
3028 if (dynstr != NULL && dynstr->output_section != bfd_abs_section_ptr)
3030 bfd_size_type strsize;
3032 strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3033 if (! elf_add_dynamic_entry (info, DT_HASH, 0)
3034 || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
3035 || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
3036 || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
3037 || ! elf_add_dynamic_entry (info, DT_SYMENT,
3038 sizeof (Elf_External_Sym)))
3039 return false;
3043 /* The backend must work out the sizes of all the other dynamic
3044 sections. */
3045 if (bed->elf_backend_size_dynamic_sections
3046 && ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
3047 return false;
3049 if (elf_hash_table (info)->dynamic_sections_created)
3051 size_t dynsymcount;
3052 asection *s;
3053 size_t bucketcount = 0;
3054 size_t hash_entry_size;
3056 /* Set up the version definition section. */
3057 s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
3058 BFD_ASSERT (s != NULL);
3060 /* We may have created additional version definitions if we are
3061 just linking a regular application. */
3062 verdefs = asvinfo.verdefs;
3064 if (verdefs == NULL)
3065 _bfd_strip_section_from_output (info, s);
3066 else
3068 unsigned int cdefs;
3069 bfd_size_type size;
3070 struct bfd_elf_version_tree *t;
3071 bfd_byte *p;
3072 Elf_Internal_Verdef def;
3073 Elf_Internal_Verdaux defaux;
3075 cdefs = 0;
3076 size = 0;
3078 /* Make space for the base version. */
3079 size += sizeof (Elf_External_Verdef);
3080 size += sizeof (Elf_External_Verdaux);
3081 ++cdefs;
3083 for (t = verdefs; t != NULL; t = t->next)
3085 struct bfd_elf_version_deps *n;
3087 size += sizeof (Elf_External_Verdef);
3088 size += sizeof (Elf_External_Verdaux);
3089 ++cdefs;
3091 for (n = t->deps; n != NULL; n = n->next)
3092 size += sizeof (Elf_External_Verdaux);
3095 s->_raw_size = size;
3096 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3097 if (s->contents == NULL && s->_raw_size != 0)
3098 return false;
3100 /* Fill in the version definition section. */
3102 p = s->contents;
3104 def.vd_version = VER_DEF_CURRENT;
3105 def.vd_flags = VER_FLG_BASE;
3106 def.vd_ndx = 1;
3107 def.vd_cnt = 1;
3108 def.vd_aux = sizeof (Elf_External_Verdef);
3109 def.vd_next = (sizeof (Elf_External_Verdef)
3110 + sizeof (Elf_External_Verdaux));
3112 if (soname_indx != (bfd_size_type) -1)
3114 def.vd_hash = bfd_elf_hash (soname);
3115 defaux.vda_name = soname_indx;
3117 else
3119 const char *name;
3120 bfd_size_type indx;
3122 name = output_bfd->filename;
3123 def.vd_hash = bfd_elf_hash (name);
3124 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3125 name, true, false);
3126 if (indx == (bfd_size_type) -1)
3127 return false;
3128 defaux.vda_name = indx;
3130 defaux.vda_next = 0;
3132 _bfd_elf_swap_verdef_out (output_bfd, &def,
3133 (Elf_External_Verdef *)p);
3134 p += sizeof (Elf_External_Verdef);
3135 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3136 (Elf_External_Verdaux *) p);
3137 p += sizeof (Elf_External_Verdaux);
3139 for (t = verdefs; t != NULL; t = t->next)
3141 unsigned int cdeps;
3142 struct bfd_elf_version_deps *n;
3143 struct elf_link_hash_entry *h;
3145 cdeps = 0;
3146 for (n = t->deps; n != NULL; n = n->next)
3147 ++cdeps;
3149 /* Add a symbol representing this version. */
3150 h = NULL;
3151 if (! (_bfd_generic_link_add_one_symbol
3152 (info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
3153 (bfd_vma) 0, (const char *) NULL, false,
3154 get_elf_backend_data (dynobj)->collect,
3155 (struct bfd_link_hash_entry **) &h)))
3156 return false;
3157 h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
3158 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3159 h->type = STT_OBJECT;
3160 h->verinfo.vertree = t;
3162 if (! _bfd_elf_link_record_dynamic_symbol (info, h))
3163 return false;
3165 def.vd_version = VER_DEF_CURRENT;
3166 def.vd_flags = 0;
3167 if (t->globals == NULL && t->locals == NULL && ! t->used)
3168 def.vd_flags |= VER_FLG_WEAK;
3169 def.vd_ndx = t->vernum + 1;
3170 def.vd_cnt = cdeps + 1;
3171 def.vd_hash = bfd_elf_hash (t->name);
3172 def.vd_aux = sizeof (Elf_External_Verdef);
3173 if (t->next != NULL)
3174 def.vd_next = (sizeof (Elf_External_Verdef)
3175 + (cdeps + 1) * sizeof (Elf_External_Verdaux));
3176 else
3177 def.vd_next = 0;
3179 _bfd_elf_swap_verdef_out (output_bfd, &def,
3180 (Elf_External_Verdef *) p);
3181 p += sizeof (Elf_External_Verdef);
3183 defaux.vda_name = h->dynstr_index;
3184 if (t->deps == NULL)
3185 defaux.vda_next = 0;
3186 else
3187 defaux.vda_next = sizeof (Elf_External_Verdaux);
3188 t->name_indx = defaux.vda_name;
3190 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3191 (Elf_External_Verdaux *) p);
3192 p += sizeof (Elf_External_Verdaux);
3194 for (n = t->deps; n != NULL; n = n->next)
3196 if (n->version_needed == NULL)
3198 /* This can happen if there was an error in the
3199 version script. */
3200 defaux.vda_name = 0;
3202 else
3203 defaux.vda_name = n->version_needed->name_indx;
3204 if (n->next == NULL)
3205 defaux.vda_next = 0;
3206 else
3207 defaux.vda_next = sizeof (Elf_External_Verdaux);
3209 _bfd_elf_swap_verdaux_out (output_bfd, &defaux,
3210 (Elf_External_Verdaux *) p);
3211 p += sizeof (Elf_External_Verdaux);
3215 if (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
3216 || ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
3217 return false;
3219 elf_tdata (output_bfd)->cverdefs = cdefs;
3222 if (info->new_dtags && info->flags)
3224 if (! elf_add_dynamic_entry (info, DT_FLAGS, info->flags))
3225 return false;
3228 if (info->flags_1)
3230 if (! info->shared)
3231 info->flags_1 &= ~ (DF_1_INITFIRST
3232 | DF_1_NODELETE
3233 | DF_1_NOOPEN);
3234 if (! elf_add_dynamic_entry (info, DT_FLAGS_1, info->flags_1))
3235 return false;
3238 /* Work out the size of the version reference section. */
3240 s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
3241 BFD_ASSERT (s != NULL);
3243 struct elf_find_verdep_info sinfo;
3245 sinfo.output_bfd = output_bfd;
3246 sinfo.info = info;
3247 sinfo.vers = elf_tdata (output_bfd)->cverdefs;
3248 if (sinfo.vers == 0)
3249 sinfo.vers = 1;
3250 sinfo.failed = false;
3252 elf_link_hash_traverse (elf_hash_table (info),
3253 elf_link_find_version_dependencies,
3254 (PTR) &sinfo);
3256 if (elf_tdata (output_bfd)->verref == NULL)
3257 _bfd_strip_section_from_output (info, s);
3258 else
3260 Elf_Internal_Verneed *t;
3261 unsigned int size;
3262 unsigned int crefs;
3263 bfd_byte *p;
3265 /* Build the version definition section. */
3266 size = 0;
3267 crefs = 0;
3268 for (t = elf_tdata (output_bfd)->verref;
3269 t != NULL;
3270 t = t->vn_nextref)
3272 Elf_Internal_Vernaux *a;
3274 size += sizeof (Elf_External_Verneed);
3275 ++crefs;
3276 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3277 size += sizeof (Elf_External_Vernaux);
3280 s->_raw_size = size;
3281 s->contents = (bfd_byte *) bfd_alloc (output_bfd, size);
3282 if (s->contents == NULL)
3283 return false;
3285 p = s->contents;
3286 for (t = elf_tdata (output_bfd)->verref;
3287 t != NULL;
3288 t = t->vn_nextref)
3290 unsigned int caux;
3291 Elf_Internal_Vernaux *a;
3292 bfd_size_type indx;
3294 caux = 0;
3295 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3296 ++caux;
3298 t->vn_version = VER_NEED_CURRENT;
3299 t->vn_cnt = caux;
3300 if (elf_dt_name (t->vn_bfd) != NULL)
3301 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3302 elf_dt_name (t->vn_bfd),
3303 true, false);
3304 else
3305 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3306 t->vn_bfd->filename, true, false);
3307 if (indx == (bfd_size_type) -1)
3308 return false;
3309 t->vn_file = indx;
3310 t->vn_aux = sizeof (Elf_External_Verneed);
3311 if (t->vn_nextref == NULL)
3312 t->vn_next = 0;
3313 else
3314 t->vn_next = (sizeof (Elf_External_Verneed)
3315 + caux * sizeof (Elf_External_Vernaux));
3317 _bfd_elf_swap_verneed_out (output_bfd, t,
3318 (Elf_External_Verneed *) p);
3319 p += sizeof (Elf_External_Verneed);
3321 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3323 a->vna_hash = bfd_elf_hash (a->vna_nodename);
3324 indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
3325 a->vna_nodename, true, false);
3326 if (indx == (bfd_size_type) -1)
3327 return false;
3328 a->vna_name = indx;
3329 if (a->vna_nextptr == NULL)
3330 a->vna_next = 0;
3331 else
3332 a->vna_next = sizeof (Elf_External_Vernaux);
3334 _bfd_elf_swap_vernaux_out (output_bfd, a,
3335 (Elf_External_Vernaux *) p);
3336 p += sizeof (Elf_External_Vernaux);
3340 if (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
3341 || ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
3342 return false;
3344 elf_tdata (output_bfd)->cverrefs = crefs;
3348 /* Assign dynsym indicies. In a shared library we generate a
3349 section symbol for each output section, which come first.
3350 Next come all of the back-end allocated local dynamic syms,
3351 followed by the rest of the global symbols. */
3353 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3355 /* Work out the size of the symbol version section. */
3356 s = bfd_get_section_by_name (dynobj, ".gnu.version");
3357 BFD_ASSERT (s != NULL);
3358 if (dynsymcount == 0
3359 || (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
3361 _bfd_strip_section_from_output (info, s);
3362 /* The DYNSYMCOUNT might have changed if we were going to
3363 output a dynamic symbol table entry for S. */
3364 dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info);
3366 else
3368 s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
3369 s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
3370 if (s->contents == NULL)
3371 return false;
3373 if (! elf_add_dynamic_entry (info, DT_VERSYM, 0))
3374 return false;
3377 /* Set the size of the .dynsym and .hash sections. We counted
3378 the number of dynamic symbols in elf_link_add_object_symbols.
3379 We will build the contents of .dynsym and .hash when we build
3380 the final symbol table, because until then we do not know the
3381 correct value to give the symbols. We built the .dynstr
3382 section as we went along in elf_link_add_object_symbols. */
3383 s = bfd_get_section_by_name (dynobj, ".dynsym");
3384 BFD_ASSERT (s != NULL);
3385 s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
3386 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3387 if (s->contents == NULL && s->_raw_size != 0)
3388 return false;
3390 if (dynsymcount != 0)
3392 Elf_Internal_Sym isym;
3394 /* The first entry in .dynsym is a dummy symbol. */
3395 isym.st_value = 0;
3396 isym.st_size = 0;
3397 isym.st_name = 0;
3398 isym.st_info = 0;
3399 isym.st_other = 0;
3400 isym.st_shndx = 0;
3401 elf_swap_symbol_out (output_bfd, &isym,
3402 (PTR) (Elf_External_Sym *) s->contents);
3405 /* Compute the size of the hashing table. As a side effect this
3406 computes the hash values for all the names we export. */
3407 bucketcount = compute_bucket_count (info);
3409 s = bfd_get_section_by_name (dynobj, ".hash");
3410 BFD_ASSERT (s != NULL);
3411 hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
3412 s->_raw_size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
3413 s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
3414 if (s->contents == NULL)
3415 return false;
3416 memset (s->contents, 0, (size_t) s->_raw_size);
3418 bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
3419 bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
3420 s->contents + hash_entry_size);
3422 elf_hash_table (info)->bucketcount = bucketcount;
3424 s = bfd_get_section_by_name (dynobj, ".dynstr");
3425 BFD_ASSERT (s != NULL);
3426 s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
3428 if (! elf_add_dynamic_entry (info, DT_NULL, 0))
3429 return false;
3432 return true;
3435 /* Fix up the flags for a symbol. This handles various cases which
3436 can only be fixed after all the input files are seen. This is
3437 currently called by both adjust_dynamic_symbol and
3438 assign_sym_version, which is unnecessary but perhaps more robust in
3439 the face of future changes. */
3441 static boolean
3442 elf_fix_symbol_flags (h, eif)
3443 struct elf_link_hash_entry *h;
3444 struct elf_info_failed *eif;
3446 /* If this symbol was mentioned in a non-ELF file, try to set
3447 DEF_REGULAR and REF_REGULAR correctly. This is the only way to
3448 permit a non-ELF file to correctly refer to a symbol defined in
3449 an ELF dynamic object. */
3450 if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
3452 while (h->root.type == bfd_link_hash_indirect)
3453 h = (struct elf_link_hash_entry *) h->root.u.i.link;
3455 if (h->root.type != bfd_link_hash_defined
3456 && h->root.type != bfd_link_hash_defweak)
3457 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3458 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3459 else
3461 if (h->root.u.def.section->owner != NULL
3462 && (bfd_get_flavour (h->root.u.def.section->owner)
3463 == bfd_target_elf_flavour))
3464 h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
3465 | ELF_LINK_HASH_REF_REGULAR_NONWEAK);
3466 else
3467 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3470 if (h->dynindx == -1
3471 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
3472 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
3474 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3476 eif->failed = true;
3477 return false;
3481 else
3483 /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol
3484 was first seen in a non-ELF file. Fortunately, if the symbol
3485 was first seen in an ELF file, we're probably OK unless the
3486 symbol was defined in a non-ELF file. Catch that case here.
3487 FIXME: We're still in trouble if the symbol was first seen in
3488 a dynamic object, and then later in a non-ELF regular object. */
3489 if ((h->root.type == bfd_link_hash_defined
3490 || h->root.type == bfd_link_hash_defweak)
3491 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3492 && (h->root.u.def.section->owner != NULL
3493 ? (bfd_get_flavour (h->root.u.def.section->owner)
3494 != bfd_target_elf_flavour)
3495 : (bfd_is_abs_section (h->root.u.def.section)
3496 && (h->elf_link_hash_flags
3497 & ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
3498 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3501 /* If this is a final link, and the symbol was defined as a common
3502 symbol in a regular object file, and there was no definition in
3503 any dynamic object, then the linker will have allocated space for
3504 the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR
3505 flag will not have been set. */
3506 if (h->root.type == bfd_link_hash_defined
3507 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
3508 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
3509 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3510 && (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
3511 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
3513 /* If -Bsymbolic was used (which means to bind references to global
3514 symbols to the definition within the shared object), and this
3515 symbol was defined in a regular object, then it actually doesn't
3516 need a PLT entry. Likewise, if the symbol has any kind of
3517 visibility (internal, hidden, or protected), it doesn't need a
3518 PLT. */
3519 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
3520 && eif->info->shared
3521 && (eif->info->symbolic || ELF_ST_VISIBILITY (h->other))
3522 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3524 h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
3525 h->plt.offset = (bfd_vma) -1;
3528 /* If this is a weak defined symbol in a dynamic object, and we know
3529 the real definition in the dynamic object, copy interesting flags
3530 over to the real definition. */
3531 if (h->weakdef != NULL)
3533 struct elf_link_hash_entry *weakdef;
3535 BFD_ASSERT (h->root.type == bfd_link_hash_defined
3536 || h->root.type == bfd_link_hash_defweak);
3537 weakdef = h->weakdef;
3538 BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
3539 || weakdef->root.type == bfd_link_hash_defweak);
3540 BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
3542 /* If the real definition is defined by a regular object file,
3543 don't do anything special. See the longer description in
3544 elf_adjust_dynamic_symbol, below. */
3545 if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
3546 h->weakdef = NULL;
3547 else
3548 weakdef->elf_link_hash_flags |=
3549 (h->elf_link_hash_flags
3550 & (ELF_LINK_HASH_REF_REGULAR
3551 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3552 | ELF_LINK_NON_GOT_REF));
3555 return true;
3558 /* Make the backend pick a good value for a dynamic symbol. This is
3559 called via elf_link_hash_traverse, and also calls itself
3560 recursively. */
3562 static boolean
3563 elf_adjust_dynamic_symbol (h, data)
3564 struct elf_link_hash_entry *h;
3565 PTR data;
3567 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3568 bfd *dynobj;
3569 struct elf_backend_data *bed;
3571 /* Ignore indirect symbols. These are added by the versioning code. */
3572 if (h->root.type == bfd_link_hash_indirect)
3573 return true;
3575 /* Fix the symbol flags. */
3576 if (! elf_fix_symbol_flags (h, eif))
3577 return false;
3579 /* If this symbol does not require a PLT entry, and it is not
3580 defined by a dynamic object, or is not referenced by a regular
3581 object, ignore it. We do have to handle a weak defined symbol,
3582 even if no regular object refers to it, if we decided to add it
3583 to the dynamic symbol table. FIXME: Do we normally need to worry
3584 about symbols which are defined by one dynamic object and
3585 referenced by another one? */
3586 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
3587 && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3588 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3589 || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
3590 && (h->weakdef == NULL || h->weakdef->dynindx == -1))))
3592 h->plt.offset = (bfd_vma) -1;
3593 return true;
3596 /* If we've already adjusted this symbol, don't do it again. This
3597 can happen via a recursive call. */
3598 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
3599 return true;
3601 /* Don't look at this symbol again. Note that we must set this
3602 after checking the above conditions, because we may look at a
3603 symbol once, decide not to do anything, and then get called
3604 recursively later after REF_REGULAR is set below. */
3605 h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
3607 /* If this is a weak definition, and we know a real definition, and
3608 the real symbol is not itself defined by a regular object file,
3609 then get a good value for the real definition. We handle the
3610 real symbol first, for the convenience of the backend routine.
3612 Note that there is a confusing case here. If the real definition
3613 is defined by a regular object file, we don't get the real symbol
3614 from the dynamic object, but we do get the weak symbol. If the
3615 processor backend uses a COPY reloc, then if some routine in the
3616 dynamic object changes the real symbol, we will not see that
3617 change in the corresponding weak symbol. This is the way other
3618 ELF linkers work as well, and seems to be a result of the shared
3619 library model.
3621 I will clarify this issue. Most SVR4 shared libraries define the
3622 variable _timezone and define timezone as a weak synonym. The
3623 tzset call changes _timezone. If you write
3624 extern int timezone;
3625 int _timezone = 5;
3626 int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
3627 you might expect that, since timezone is a synonym for _timezone,
3628 the same number will print both times. However, if the processor
3629 backend uses a COPY reloc, then actually timezone will be copied
3630 into your process image, and, since you define _timezone
3631 yourself, _timezone will not. Thus timezone and _timezone will
3632 wind up at different memory locations. The tzset call will set
3633 _timezone, leaving timezone unchanged. */
3635 if (h->weakdef != NULL)
3637 /* If we get to this point, we know there is an implicit
3638 reference by a regular object file via the weak symbol H.
3639 FIXME: Is this really true? What if the traversal finds
3640 H->WEAKDEF before it finds H? */
3641 h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
3643 if (! elf_adjust_dynamic_symbol (h->weakdef, (PTR) eif))
3644 return false;
3647 /* If a symbol has no type and no size and does not require a PLT
3648 entry, then we are probably about to do the wrong thing here: we
3649 are probably going to create a COPY reloc for an empty object.
3650 This case can arise when a shared object is built with assembly
3651 code, and the assembly code fails to set the symbol type. */
3652 if (h->size == 0
3653 && h->type == STT_NOTYPE
3654 && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
3655 (*_bfd_error_handler)
3656 (_("warning: type and size of dynamic symbol `%s' are not defined"),
3657 h->root.root.string);
3659 dynobj = elf_hash_table (eif->info)->dynobj;
3660 bed = get_elf_backend_data (dynobj);
3661 if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
3663 eif->failed = true;
3664 return false;
3667 return true;
3670 /* This routine is used to export all defined symbols into the dynamic
3671 symbol table. It is called via elf_link_hash_traverse. */
3673 static boolean
3674 elf_export_symbol (h, data)
3675 struct elf_link_hash_entry *h;
3676 PTR data;
3678 struct elf_info_failed *eif = (struct elf_info_failed *) data;
3680 /* Ignore indirect symbols. These are added by the versioning code. */
3681 if (h->root.type == bfd_link_hash_indirect)
3682 return true;
3684 if (h->dynindx == -1
3685 && (h->elf_link_hash_flags
3686 & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
3688 if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
3690 eif->failed = true;
3691 return false;
3695 return true;
3698 /* Look through the symbols which are defined in other shared
3699 libraries and referenced here. Update the list of version
3700 dependencies. This will be put into the .gnu.version_r section.
3701 This function is called via elf_link_hash_traverse. */
3703 static boolean
3704 elf_link_find_version_dependencies (h, data)
3705 struct elf_link_hash_entry *h;
3706 PTR data;
3708 struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
3709 Elf_Internal_Verneed *t;
3710 Elf_Internal_Vernaux *a;
3712 /* We only care about symbols defined in shared objects with version
3713 information. */
3714 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
3715 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
3716 || h->dynindx == -1
3717 || h->verinfo.verdef == NULL)
3718 return true;
3720 /* See if we already know about this version. */
3721 for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
3723 if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
3724 continue;
3726 for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
3727 if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
3728 return true;
3730 break;
3733 /* This is a new version. Add it to tree we are building. */
3735 if (t == NULL)
3737 t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
3738 if (t == NULL)
3740 rinfo->failed = true;
3741 return false;
3744 t->vn_bfd = h->verinfo.verdef->vd_bfd;
3745 t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
3746 elf_tdata (rinfo->output_bfd)->verref = t;
3749 a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
3751 /* Note that we are copying a string pointer here, and testing it
3752 above. If bfd_elf_string_from_elf_section is ever changed to
3753 discard the string data when low in memory, this will have to be
3754 fixed. */
3755 a->vna_nodename = h->verinfo.verdef->vd_nodename;
3757 a->vna_flags = h->verinfo.verdef->vd_flags;
3758 a->vna_nextptr = t->vn_auxptr;
3760 h->verinfo.verdef->vd_exp_refno = rinfo->vers;
3761 ++rinfo->vers;
3763 a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
3765 t->vn_auxptr = a;
3767 return true;
3770 /* Figure out appropriate versions for all the symbols. We may not
3771 have the version number script until we have read all of the input
3772 files, so until that point we don't know which symbols should be
3773 local. This function is called via elf_link_hash_traverse. */
3775 static boolean
3776 elf_link_assign_sym_version (h, data)
3777 struct elf_link_hash_entry *h;
3778 PTR data;
3780 struct elf_assign_sym_version_info *sinfo =
3781 (struct elf_assign_sym_version_info *) data;
3782 struct bfd_link_info *info = sinfo->info;
3783 struct elf_backend_data *bed;
3784 struct elf_info_failed eif;
3785 char *p;
3787 /* Fix the symbol flags. */
3788 eif.failed = false;
3789 eif.info = info;
3790 if (! elf_fix_symbol_flags (h, &eif))
3792 if (eif.failed)
3793 sinfo->failed = true;
3794 return false;
3797 /* We only need version numbers for symbols defined in regular
3798 objects. */
3799 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3800 return true;
3802 bed = get_elf_backend_data (sinfo->output_bfd);
3803 p = strchr (h->root.root.string, ELF_VER_CHR);
3804 if (p != NULL && h->verinfo.vertree == NULL)
3806 struct bfd_elf_version_tree *t;
3807 boolean hidden;
3809 hidden = true;
3811 /* There are two consecutive ELF_VER_CHR characters if this is
3812 not a hidden symbol. */
3813 ++p;
3814 if (*p == ELF_VER_CHR)
3816 hidden = false;
3817 ++p;
3820 /* If there is no version string, we can just return out. */
3821 if (*p == '\0')
3823 if (hidden)
3824 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3825 return true;
3828 /* Look for the version. If we find it, it is no longer weak. */
3829 for (t = sinfo->verdefs; t != NULL; t = t->next)
3831 if (strcmp (t->name, p) == 0)
3833 int len;
3834 char *alc;
3835 struct bfd_elf_version_expr *d;
3837 len = p - h->root.root.string;
3838 alc = bfd_alloc (sinfo->output_bfd, len);
3839 if (alc == NULL)
3840 return false;
3841 strncpy (alc, h->root.root.string, len - 1);
3842 alc[len - 1] = '\0';
3843 if (alc[len - 2] == ELF_VER_CHR)
3844 alc[len - 2] = '\0';
3846 h->verinfo.vertree = t;
3847 t->used = true;
3848 d = NULL;
3850 if (t->globals != NULL)
3852 for (d = t->globals; d != NULL; d = d->next)
3853 if ((*d->match) (d, alc))
3854 break;
3857 /* See if there is anything to force this symbol to
3858 local scope. */
3859 if (d == NULL && t->locals != NULL)
3861 for (d = t->locals; d != NULL; d = d->next)
3863 if ((*d->match) (d, alc))
3865 if (h->dynindx != -1
3866 && info->shared
3867 && ! sinfo->export_dynamic)
3869 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3870 (*bed->elf_backend_hide_symbol) (info, h);
3871 /* FIXME: The name of the symbol has
3872 already been recorded in the dynamic
3873 string table section. */
3876 break;
3881 bfd_release (sinfo->output_bfd, alc);
3882 break;
3886 /* If we are building an application, we need to create a
3887 version node for this version. */
3888 if (t == NULL && ! info->shared)
3890 struct bfd_elf_version_tree **pp;
3891 int version_index;
3893 /* If we aren't going to export this symbol, we don't need
3894 to worry about it. */
3895 if (h->dynindx == -1)
3896 return true;
3898 t = ((struct bfd_elf_version_tree *)
3899 bfd_alloc (sinfo->output_bfd, sizeof *t));
3900 if (t == NULL)
3902 sinfo->failed = true;
3903 return false;
3906 t->next = NULL;
3907 t->name = p;
3908 t->globals = NULL;
3909 t->locals = NULL;
3910 t->deps = NULL;
3911 t->name_indx = (unsigned int) -1;
3912 t->used = true;
3914 version_index = 1;
3915 for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
3916 ++version_index;
3917 t->vernum = version_index;
3919 *pp = t;
3921 h->verinfo.vertree = t;
3923 else if (t == NULL)
3925 /* We could not find the version for a symbol when
3926 generating a shared archive. Return an error. */
3927 (*_bfd_error_handler)
3928 (_("%s: undefined versioned symbol name %s"),
3929 bfd_get_filename (sinfo->output_bfd), h->root.root.string);
3930 bfd_set_error (bfd_error_bad_value);
3931 sinfo->failed = true;
3932 return false;
3935 if (hidden)
3936 h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
3939 /* If we don't have a version for this symbol, see if we can find
3940 something. */
3941 if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
3943 struct bfd_elf_version_tree *t;
3944 struct bfd_elf_version_tree *deflt;
3945 struct bfd_elf_version_expr *d;
3947 /* See if can find what version this symbol is in. If the
3948 symbol is supposed to be local, then don't actually register
3949 it. */
3950 deflt = NULL;
3951 for (t = sinfo->verdefs; t != NULL; t = t->next)
3953 if (t->globals != NULL)
3955 for (d = t->globals; d != NULL; d = d->next)
3957 if ((*d->match) (d, h->root.root.string))
3959 h->verinfo.vertree = t;
3960 break;
3964 if (d != NULL)
3965 break;
3968 if (t->locals != NULL)
3970 for (d = t->locals; d != NULL; d = d->next)
3972 if (d->pattern[0] == '*' && d->pattern[1] == '\0')
3973 deflt = t;
3974 else if ((*d->match) (d, h->root.root.string))
3976 h->verinfo.vertree = t;
3977 if (h->dynindx != -1
3978 && info->shared
3979 && ! sinfo->export_dynamic)
3981 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
3982 (*bed->elf_backend_hide_symbol) (info, h);
3983 /* FIXME: The name of the symbol has already
3984 been recorded in the dynamic string table
3985 section. */
3987 break;
3991 if (d != NULL)
3992 break;
3996 if (deflt != NULL && h->verinfo.vertree == NULL)
3998 h->verinfo.vertree = deflt;
3999 if (h->dynindx != -1
4000 && info->shared
4001 && ! sinfo->export_dynamic)
4003 h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
4004 (*bed->elf_backend_hide_symbol) (info, h);
4005 /* FIXME: The name of the symbol has already been
4006 recorded in the dynamic string table section. */
4011 return true;
4014 /* Final phase of ELF linker. */
4016 /* A structure we use to avoid passing large numbers of arguments. */
4018 struct elf_final_link_info
4020 /* General link information. */
4021 struct bfd_link_info *info;
4022 /* Output BFD. */
4023 bfd *output_bfd;
4024 /* Symbol string table. */
4025 struct bfd_strtab_hash *symstrtab;
4026 /* .dynsym section. */
4027 asection *dynsym_sec;
4028 /* .hash section. */
4029 asection *hash_sec;
4030 /* symbol version section (.gnu.version). */
4031 asection *symver_sec;
4032 /* Buffer large enough to hold contents of any section. */
4033 bfd_byte *contents;
4034 /* Buffer large enough to hold external relocs of any section. */
4035 PTR external_relocs;
4036 /* Buffer large enough to hold internal relocs of any section. */
4037 Elf_Internal_Rela *internal_relocs;
4038 /* Buffer large enough to hold external local symbols of any input
4039 BFD. */
4040 Elf_External_Sym *external_syms;
4041 /* Buffer large enough to hold internal local symbols of any input
4042 BFD. */
4043 Elf_Internal_Sym *internal_syms;
4044 /* Array large enough to hold a symbol index for each local symbol
4045 of any input BFD. */
4046 long *indices;
4047 /* Array large enough to hold a section pointer for each local
4048 symbol of any input BFD. */
4049 asection **sections;
4050 /* Buffer to hold swapped out symbols. */
4051 Elf_External_Sym *symbuf;
4052 /* Number of swapped out symbols in buffer. */
4053 size_t symbuf_count;
4054 /* Number of symbols which fit in symbuf. */
4055 size_t symbuf_size;
4058 static boolean elf_link_output_sym
4059 PARAMS ((struct elf_final_link_info *, const char *,
4060 Elf_Internal_Sym *, asection *));
4061 static boolean elf_link_flush_output_syms
4062 PARAMS ((struct elf_final_link_info *));
4063 static boolean elf_link_output_extsym
4064 PARAMS ((struct elf_link_hash_entry *, PTR));
4065 static boolean elf_link_input_bfd
4066 PARAMS ((struct elf_final_link_info *, bfd *));
4067 static boolean elf_reloc_link_order
4068 PARAMS ((bfd *, struct bfd_link_info *, asection *,
4069 struct bfd_link_order *));
4071 /* This struct is used to pass information to elf_link_output_extsym. */
4073 struct elf_outext_info
4075 boolean failed;
4076 boolean localsyms;
4077 struct elf_final_link_info *finfo;
4080 /* Compute the size of, and allocate space for, REL_HDR which is the
4081 section header for a section containing relocations for O. */
4083 static boolean
4084 elf_link_size_reloc_section (abfd, rel_hdr, o)
4085 bfd *abfd;
4086 Elf_Internal_Shdr *rel_hdr;
4087 asection *o;
4089 register struct elf_link_hash_entry **p, **pend;
4090 unsigned reloc_count;
4092 /* Figure out how many relocations there will be. */
4093 if (rel_hdr == &elf_section_data (o)->rel_hdr)
4094 reloc_count = elf_section_data (o)->rel_count;
4095 else
4096 reloc_count = elf_section_data (o)->rel_count2;
4098 /* That allows us to calculate the size of the section. */
4099 rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
4101 /* The contents field must last into write_object_contents, so we
4102 allocate it with bfd_alloc rather than malloc. Also since we
4103 cannot be sure that the contents will actually be filled in,
4104 we zero the allocated space. */
4105 rel_hdr->contents = (PTR) bfd_zalloc (abfd, rel_hdr->sh_size);
4106 if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
4107 return false;
4109 /* We only allocate one set of hash entries, so we only do it the
4110 first time we are called. */
4111 if (elf_section_data (o)->rel_hashes == NULL)
4113 p = ((struct elf_link_hash_entry **)
4114 bfd_malloc (o->reloc_count
4115 * sizeof (struct elf_link_hash_entry *)));
4116 if (p == NULL && o->reloc_count != 0)
4117 return false;
4119 elf_section_data (o)->rel_hashes = p;
4120 pend = p + o->reloc_count;
4121 for (; p < pend; p++)
4122 *p = NULL;
4125 return true;
4128 /* When performing a relocateable link, the input relocations are
4129 preserved. But, if they reference global symbols, the indices
4130 referenced must be updated. Update all the relocations in
4131 REL_HDR (there are COUNT of them), using the data in REL_HASH. */
4133 static void
4134 elf_link_adjust_relocs (abfd, rel_hdr, count, rel_hash)
4135 bfd *abfd;
4136 Elf_Internal_Shdr *rel_hdr;
4137 unsigned int count;
4138 struct elf_link_hash_entry **rel_hash;
4140 unsigned int i;
4141 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4143 for (i = 0; i < count; i++, rel_hash++)
4145 if (*rel_hash == NULL)
4146 continue;
4148 BFD_ASSERT ((*rel_hash)->indx >= 0);
4150 if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
4152 Elf_External_Rel *erel;
4153 Elf_Internal_Rel irel;
4155 erel = (Elf_External_Rel *) rel_hdr->contents + i;
4156 if (bed->s->swap_reloc_in)
4157 (*bed->s->swap_reloc_in) (abfd, (bfd_byte *) erel, &irel);
4158 else
4159 elf_swap_reloc_in (abfd, erel, &irel);
4160 irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
4161 ELF_R_TYPE (irel.r_info));
4162 if (bed->s->swap_reloc_out)
4163 (*bed->s->swap_reloc_out) (abfd, &irel, (bfd_byte *) erel);
4164 else
4165 elf_swap_reloc_out (abfd, &irel, erel);
4167 else
4169 Elf_External_Rela *erela;
4170 Elf_Internal_Rela irela;
4172 BFD_ASSERT (rel_hdr->sh_entsize
4173 == sizeof (Elf_External_Rela));
4175 erela = (Elf_External_Rela *) rel_hdr->contents + i;
4176 if (bed->s->swap_reloca_in)
4177 (*bed->s->swap_reloca_in) (abfd, (bfd_byte *) erela, &irela);
4178 else
4179 elf_swap_reloca_in (abfd, erela, &irela);
4180 irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
4181 ELF_R_TYPE (irela.r_info));
4182 if (bed->s->swap_reloca_out)
4183 (*bed->s->swap_reloca_out) (abfd, &irela, (bfd_byte *) erela);
4184 else
4185 elf_swap_reloca_out (abfd, &irela, erela);
4190 /* Do the final step of an ELF link. */
4192 boolean
4193 elf_bfd_final_link (abfd, info)
4194 bfd *abfd;
4195 struct bfd_link_info *info;
4197 boolean dynamic;
4198 bfd *dynobj;
4199 struct elf_final_link_info finfo;
4200 register asection *o;
4201 register struct bfd_link_order *p;
4202 register bfd *sub;
4203 size_t max_contents_size;
4204 size_t max_external_reloc_size;
4205 size_t max_internal_reloc_count;
4206 size_t max_sym_count;
4207 file_ptr off;
4208 Elf_Internal_Sym elfsym;
4209 unsigned int i;
4210 Elf_Internal_Shdr *symtab_hdr;
4211 Elf_Internal_Shdr *symstrtab_hdr;
4212 struct elf_backend_data *bed = get_elf_backend_data (abfd);
4213 struct elf_outext_info eoinfo;
4215 if (info->shared)
4216 abfd->flags |= DYNAMIC;
4218 dynamic = elf_hash_table (info)->dynamic_sections_created;
4219 dynobj = elf_hash_table (info)->dynobj;
4221 finfo.info = info;
4222 finfo.output_bfd = abfd;
4223 finfo.symstrtab = elf_stringtab_init ();
4224 if (finfo.symstrtab == NULL)
4225 return false;
4227 if (! dynamic)
4229 finfo.dynsym_sec = NULL;
4230 finfo.hash_sec = NULL;
4231 finfo.symver_sec = NULL;
4233 else
4235 finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
4236 finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
4237 BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
4238 finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
4239 /* Note that it is OK if symver_sec is NULL. */
4242 finfo.contents = NULL;
4243 finfo.external_relocs = NULL;
4244 finfo.internal_relocs = NULL;
4245 finfo.external_syms = NULL;
4246 finfo.internal_syms = NULL;
4247 finfo.indices = NULL;
4248 finfo.sections = NULL;
4249 finfo.symbuf = NULL;
4250 finfo.symbuf_count = 0;
4252 /* Count up the number of relocations we will output for each output
4253 section, so that we know the sizes of the reloc sections. We
4254 also figure out some maximum sizes. */
4255 max_contents_size = 0;
4256 max_external_reloc_size = 0;
4257 max_internal_reloc_count = 0;
4258 max_sym_count = 0;
4259 for (o = abfd->sections; o != (asection *) NULL; o = o->next)
4261 o->reloc_count = 0;
4263 for (p = o->link_order_head; p != NULL; p = p->next)
4265 if (p->type == bfd_section_reloc_link_order
4266 || p->type == bfd_symbol_reloc_link_order)
4267 ++o->reloc_count;
4268 else if (p->type == bfd_indirect_link_order)
4270 asection *sec;
4272 sec = p->u.indirect.section;
4274 /* Mark all sections which are to be included in the
4275 link. This will normally be every section. We need
4276 to do this so that we can identify any sections which
4277 the linker has decided to not include. */
4278 sec->linker_mark = true;
4280 if (info->relocateable || info->emitrelocations)
4281 o->reloc_count += sec->reloc_count;
4283 if (sec->_raw_size > max_contents_size)
4284 max_contents_size = sec->_raw_size;
4285 if (sec->_cooked_size > max_contents_size)
4286 max_contents_size = sec->_cooked_size;
4288 /* We are interested in just local symbols, not all
4289 symbols. */
4290 if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
4291 && (sec->owner->flags & DYNAMIC) == 0)
4293 size_t sym_count;
4295 if (elf_bad_symtab (sec->owner))
4296 sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
4297 / sizeof (Elf_External_Sym));
4298 else
4299 sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
4301 if (sym_count > max_sym_count)
4302 max_sym_count = sym_count;
4304 if ((sec->flags & SEC_RELOC) != 0)
4306 size_t ext_size;
4308 ext_size = elf_section_data (sec)->rel_hdr.sh_size;
4309 if (ext_size > max_external_reloc_size)
4310 max_external_reloc_size = ext_size;
4311 if (sec->reloc_count > max_internal_reloc_count)
4312 max_internal_reloc_count = sec->reloc_count;
4318 if (o->reloc_count > 0)
4319 o->flags |= SEC_RELOC;
4320 else
4322 /* Explicitly clear the SEC_RELOC flag. The linker tends to
4323 set it (this is probably a bug) and if it is set
4324 assign_section_numbers will create a reloc section. */
4325 o->flags &=~ SEC_RELOC;
4328 /* If the SEC_ALLOC flag is not set, force the section VMA to
4329 zero. This is done in elf_fake_sections as well, but forcing
4330 the VMA to 0 here will ensure that relocs against these
4331 sections are handled correctly. */
4332 if ((o->flags & SEC_ALLOC) == 0
4333 && ! o->user_set_vma)
4334 o->vma = 0;
4337 /* Figure out the file positions for everything but the symbol table
4338 and the relocs. We set symcount to force assign_section_numbers
4339 to create a symbol table. */
4340 bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
4341 BFD_ASSERT (! abfd->output_has_begun);
4342 if (! _bfd_elf_compute_section_file_positions (abfd, info))
4343 goto error_return;
4345 /* Figure out how many relocations we will have in each section.
4346 Just using RELOC_COUNT isn't good enough since that doesn't
4347 maintain a separate value for REL vs. RELA relocations. */
4348 if (info->relocateable || info->emitrelocations)
4349 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4350 for (o = sub->sections; o != NULL; o = o->next)
4352 asection *output_section;
4354 if (! o->linker_mark)
4356 /* This section was omitted from the link. */
4357 continue;
4360 output_section = o->output_section;
4362 if (output_section != NULL
4363 && (o->flags & SEC_RELOC) != 0)
4365 struct bfd_elf_section_data *esdi
4366 = elf_section_data (o);
4367 struct bfd_elf_section_data *esdo
4368 = elf_section_data (output_section);
4369 unsigned int *rel_count;
4370 unsigned int *rel_count2;
4372 /* We must be careful to add the relocation froms the
4373 input section to the right output count. */
4374 if (esdi->rel_hdr.sh_entsize == esdo->rel_hdr.sh_entsize)
4376 rel_count = &esdo->rel_count;
4377 rel_count2 = &esdo->rel_count2;
4379 else
4381 rel_count = &esdo->rel_count2;
4382 rel_count2 = &esdo->rel_count;
4385 *rel_count += (esdi->rel_hdr.sh_size
4386 / esdi->rel_hdr.sh_entsize);
4387 if (esdi->rel_hdr2)
4388 *rel_count2 += (esdi->rel_hdr2->sh_size
4389 / esdi->rel_hdr2->sh_entsize);
4393 /* That created the reloc sections. Set their sizes, and assign
4394 them file positions, and allocate some buffers. */
4395 for (o = abfd->sections; o != NULL; o = o->next)
4397 if ((o->flags & SEC_RELOC) != 0)
4399 if (!elf_link_size_reloc_section (abfd,
4400 &elf_section_data (o)->rel_hdr,
4402 goto error_return;
4404 if (elf_section_data (o)->rel_hdr2
4405 && !elf_link_size_reloc_section (abfd,
4406 elf_section_data (o)->rel_hdr2,
4408 goto error_return;
4411 /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
4412 to count upwards while actually outputting the relocations. */
4413 elf_section_data (o)->rel_count = 0;
4414 elf_section_data (o)->rel_count2 = 0;
4417 _bfd_elf_assign_file_positions_for_relocs (abfd);
4419 /* We have now assigned file positions for all the sections except
4420 .symtab and .strtab. We start the .symtab section at the current
4421 file position, and write directly to it. We build the .strtab
4422 section in memory. */
4423 bfd_get_symcount (abfd) = 0;
4424 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
4425 /* sh_name is set in prep_headers. */
4426 symtab_hdr->sh_type = SHT_SYMTAB;
4427 symtab_hdr->sh_flags = 0;
4428 symtab_hdr->sh_addr = 0;
4429 symtab_hdr->sh_size = 0;
4430 symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
4431 /* sh_link is set in assign_section_numbers. */
4432 /* sh_info is set below. */
4433 /* sh_offset is set just below. */
4434 symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
4436 off = elf_tdata (abfd)->next_file_pos;
4437 off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, true);
4439 /* Note that at this point elf_tdata (abfd)->next_file_pos is
4440 incorrect. We do not yet know the size of the .symtab section.
4441 We correct next_file_pos below, after we do know the size. */
4443 /* Allocate a buffer to hold swapped out symbols. This is to avoid
4444 continuously seeking to the right position in the file. */
4445 if (! info->keep_memory || max_sym_count < 20)
4446 finfo.symbuf_size = 20;
4447 else
4448 finfo.symbuf_size = max_sym_count;
4449 finfo.symbuf = ((Elf_External_Sym *)
4450 bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
4451 if (finfo.symbuf == NULL)
4452 goto error_return;
4454 /* Start writing out the symbol table. The first symbol is always a
4455 dummy symbol. */
4456 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4458 elfsym.st_value = 0;
4459 elfsym.st_size = 0;
4460 elfsym.st_info = 0;
4461 elfsym.st_other = 0;
4462 elfsym.st_shndx = SHN_UNDEF;
4463 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4464 &elfsym, bfd_und_section_ptr))
4465 goto error_return;
4468 #if 0
4469 /* Some standard ELF linkers do this, but we don't because it causes
4470 bootstrap comparison failures. */
4471 /* Output a file symbol for the output file as the second symbol.
4472 We output this even if we are discarding local symbols, although
4473 I'm not sure if this is correct. */
4474 elfsym.st_value = 0;
4475 elfsym.st_size = 0;
4476 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
4477 elfsym.st_other = 0;
4478 elfsym.st_shndx = SHN_ABS;
4479 if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
4480 &elfsym, bfd_abs_section_ptr))
4481 goto error_return;
4482 #endif
4484 /* Output a symbol for each section. We output these even if we are
4485 discarding local symbols, since they are used for relocs. These
4486 symbols have no names. We store the index of each one in the
4487 index field of the section, so that we can find it again when
4488 outputting relocs. */
4489 if (info->strip != strip_all || info->relocateable || info->emitrelocations)
4491 elfsym.st_size = 0;
4492 elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4493 elfsym.st_other = 0;
4494 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4496 o = section_from_elf_index (abfd, i);
4497 if (o != NULL)
4498 o->target_index = bfd_get_symcount (abfd);
4499 elfsym.st_shndx = i;
4500 if (info->relocateable || o == NULL)
4501 elfsym.st_value = 0;
4502 else
4503 elfsym.st_value = o->vma;
4504 if (! elf_link_output_sym (&finfo, (const char *) NULL,
4505 &elfsym, o))
4506 goto error_return;
4510 /* Allocate some memory to hold information read in from the input
4511 files. */
4512 finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
4513 finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
4514 finfo.internal_relocs = ((Elf_Internal_Rela *)
4515 bfd_malloc (max_internal_reloc_count
4516 * sizeof (Elf_Internal_Rela)
4517 * bed->s->int_rels_per_ext_rel));
4518 finfo.external_syms = ((Elf_External_Sym *)
4519 bfd_malloc (max_sym_count
4520 * sizeof (Elf_External_Sym)));
4521 finfo.internal_syms = ((Elf_Internal_Sym *)
4522 bfd_malloc (max_sym_count
4523 * sizeof (Elf_Internal_Sym)));
4524 finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
4525 finfo.sections = ((asection **)
4526 bfd_malloc (max_sym_count * sizeof (asection *)));
4527 if ((finfo.contents == NULL && max_contents_size != 0)
4528 || (finfo.external_relocs == NULL && max_external_reloc_size != 0)
4529 || (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
4530 || (finfo.external_syms == NULL && max_sym_count != 0)
4531 || (finfo.internal_syms == NULL && max_sym_count != 0)
4532 || (finfo.indices == NULL && max_sym_count != 0)
4533 || (finfo.sections == NULL && max_sym_count != 0))
4534 goto error_return;
4536 /* Since ELF permits relocations to be against local symbols, we
4537 must have the local symbols available when we do the relocations.
4538 Since we would rather only read the local symbols once, and we
4539 would rather not keep them in memory, we handle all the
4540 relocations for a single input file at the same time.
4542 Unfortunately, there is no way to know the total number of local
4543 symbols until we have seen all of them, and the local symbol
4544 indices precede the global symbol indices. This means that when
4545 we are generating relocateable output, and we see a reloc against
4546 a global symbol, we can not know the symbol index until we have
4547 finished examining all the local symbols to see which ones we are
4548 going to output. To deal with this, we keep the relocations in
4549 memory, and don't output them until the end of the link. This is
4550 an unfortunate waste of memory, but I don't see a good way around
4551 it. Fortunately, it only happens when performing a relocateable
4552 link, which is not the common case. FIXME: If keep_memory is set
4553 we could write the relocs out and then read them again; I don't
4554 know how bad the memory loss will be. */
4556 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
4557 sub->output_has_begun = false;
4558 for (o = abfd->sections; o != NULL; o = o->next)
4560 for (p = o->link_order_head; p != NULL; p = p->next)
4562 if (p->type == bfd_indirect_link_order
4563 && (bfd_get_flavour (p->u.indirect.section->owner)
4564 == bfd_target_elf_flavour))
4566 sub = p->u.indirect.section->owner;
4567 if (! sub->output_has_begun)
4569 if (! elf_link_input_bfd (&finfo, sub))
4570 goto error_return;
4571 sub->output_has_begun = true;
4574 else if (p->type == bfd_section_reloc_link_order
4575 || p->type == bfd_symbol_reloc_link_order)
4577 if (! elf_reloc_link_order (abfd, info, o, p))
4578 goto error_return;
4580 else
4582 if (! _bfd_default_link_order (abfd, info, o, p))
4583 goto error_return;
4588 /* That wrote out all the local symbols. Finish up the symbol table
4589 with the global symbols. Even if we want to strip everything we
4590 can, we still need to deal with those global symbols that got
4591 converted to local in a version script. */
4593 if (info->shared)
4595 /* Output any global symbols that got converted to local in a
4596 version script. We do this in a separate step since ELF
4597 requires all local symbols to appear prior to any global
4598 symbols. FIXME: We should only do this if some global
4599 symbols were, in fact, converted to become local. FIXME:
4600 Will this work correctly with the Irix 5 linker? */
4601 eoinfo.failed = false;
4602 eoinfo.finfo = &finfo;
4603 eoinfo.localsyms = true;
4604 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4605 (PTR) &eoinfo);
4606 if (eoinfo.failed)
4607 return false;
4610 /* The sh_info field records the index of the first non local symbol. */
4611 symtab_hdr->sh_info = bfd_get_symcount (abfd);
4613 if (dynamic
4614 && finfo.dynsym_sec->output_section != bfd_abs_section_ptr)
4616 Elf_Internal_Sym sym;
4617 Elf_External_Sym *dynsym =
4618 (Elf_External_Sym *)finfo.dynsym_sec->contents;
4619 long last_local = 0;
4621 /* Write out the section symbols for the output sections. */
4622 if (info->shared)
4624 asection *s;
4626 sym.st_size = 0;
4627 sym.st_name = 0;
4628 sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
4629 sym.st_other = 0;
4631 for (s = abfd->sections; s != NULL; s = s->next)
4633 int indx;
4634 indx = elf_section_data (s)->this_idx;
4635 BFD_ASSERT (indx > 0);
4636 sym.st_shndx = indx;
4637 sym.st_value = s->vma;
4639 elf_swap_symbol_out (abfd, &sym,
4640 dynsym + elf_section_data (s)->dynindx);
4643 last_local = bfd_count_sections (abfd);
4646 /* Write out the local dynsyms. */
4647 if (elf_hash_table (info)->dynlocal)
4649 struct elf_link_local_dynamic_entry *e;
4650 for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
4652 asection *s;
4654 sym.st_size = e->isym.st_size;
4655 sym.st_other = e->isym.st_other;
4657 /* Copy the internal symbol as is.
4658 Note that we saved a word of storage and overwrote
4659 the original st_name with the dynstr_index. */
4660 sym = e->isym;
4662 if (e->isym.st_shndx > 0 && e->isym.st_shndx < SHN_LORESERVE)
4664 s = bfd_section_from_elf_index (e->input_bfd,
4665 e->isym.st_shndx);
4667 sym.st_shndx =
4668 elf_section_data (s->output_section)->this_idx;
4669 sym.st_value = (s->output_section->vma
4670 + s->output_offset
4671 + e->isym.st_value);
4674 if (last_local < e->dynindx)
4675 last_local = e->dynindx;
4677 elf_swap_symbol_out (abfd, &sym, dynsym + e->dynindx);
4681 elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
4682 last_local + 1;
4685 /* We get the global symbols from the hash table. */
4686 eoinfo.failed = false;
4687 eoinfo.localsyms = false;
4688 eoinfo.finfo = &finfo;
4689 elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
4690 (PTR) &eoinfo);
4691 if (eoinfo.failed)
4692 return false;
4694 /* If backend needs to output some symbols not present in the hash
4695 table, do it now. */
4696 if (bed->elf_backend_output_arch_syms)
4698 if (! (*bed->elf_backend_output_arch_syms)
4699 (abfd, info, (PTR) &finfo,
4700 (boolean (*) PARAMS ((PTR, const char *,
4701 Elf_Internal_Sym *, asection *)))
4702 elf_link_output_sym))
4703 return false;
4706 /* Flush all symbols to the file. */
4707 if (! elf_link_flush_output_syms (&finfo))
4708 return false;
4710 /* Now we know the size of the symtab section. */
4711 off += symtab_hdr->sh_size;
4713 /* Finish up and write out the symbol string table (.strtab)
4714 section. */
4715 symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
4716 /* sh_name was set in prep_headers. */
4717 symstrtab_hdr->sh_type = SHT_STRTAB;
4718 symstrtab_hdr->sh_flags = 0;
4719 symstrtab_hdr->sh_addr = 0;
4720 symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
4721 symstrtab_hdr->sh_entsize = 0;
4722 symstrtab_hdr->sh_link = 0;
4723 symstrtab_hdr->sh_info = 0;
4724 /* sh_offset is set just below. */
4725 symstrtab_hdr->sh_addralign = 1;
4727 off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, true);
4728 elf_tdata (abfd)->next_file_pos = off;
4730 if (bfd_get_symcount (abfd) > 0)
4732 if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
4733 || ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
4734 return false;
4737 /* Adjust the relocs to have the correct symbol indices. */
4738 for (o = abfd->sections; o != NULL; o = o->next)
4740 if ((o->flags & SEC_RELOC) == 0)
4741 continue;
4743 elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
4744 elf_section_data (o)->rel_count,
4745 elf_section_data (o)->rel_hashes);
4746 if (elf_section_data (o)->rel_hdr2 != NULL)
4747 elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
4748 elf_section_data (o)->rel_count2,
4749 (elf_section_data (o)->rel_hashes
4750 + elf_section_data (o)->rel_count));
4752 /* Set the reloc_count field to 0 to prevent write_relocs from
4753 trying to swap the relocs out itself. */
4754 o->reloc_count = 0;
4757 /* If we are linking against a dynamic object, or generating a
4758 shared library, finish up the dynamic linking information. */
4759 if (dynamic)
4761 Elf_External_Dyn *dyncon, *dynconend;
4763 /* Fix up .dynamic entries. */
4764 o = bfd_get_section_by_name (dynobj, ".dynamic");
4765 BFD_ASSERT (o != NULL);
4767 dyncon = (Elf_External_Dyn *) o->contents;
4768 dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
4769 for (; dyncon < dynconend; dyncon++)
4771 Elf_Internal_Dyn dyn;
4772 const char *name;
4773 unsigned int type;
4775 elf_swap_dyn_in (dynobj, dyncon, &dyn);
4777 switch (dyn.d_tag)
4779 default:
4780 break;
4781 case DT_INIT:
4782 name = info->init_function;
4783 goto get_sym;
4784 case DT_FINI:
4785 name = info->fini_function;
4786 get_sym:
4788 struct elf_link_hash_entry *h;
4790 h = elf_link_hash_lookup (elf_hash_table (info), name,
4791 false, false, true);
4792 if (h != NULL
4793 && (h->root.type == bfd_link_hash_defined
4794 || h->root.type == bfd_link_hash_defweak))
4796 dyn.d_un.d_val = h->root.u.def.value;
4797 o = h->root.u.def.section;
4798 if (o->output_section != NULL)
4799 dyn.d_un.d_val += (o->output_section->vma
4800 + o->output_offset);
4801 else
4803 /* The symbol is imported from another shared
4804 library and does not apply to this one. */
4805 dyn.d_un.d_val = 0;
4808 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4811 break;
4813 case DT_HASH:
4814 name = ".hash";
4815 goto get_vma;
4816 case DT_STRTAB:
4817 name = ".dynstr";
4818 goto get_vma;
4819 case DT_SYMTAB:
4820 name = ".dynsym";
4821 goto get_vma;
4822 case DT_VERDEF:
4823 name = ".gnu.version_d";
4824 goto get_vma;
4825 case DT_VERNEED:
4826 name = ".gnu.version_r";
4827 goto get_vma;
4828 case DT_VERSYM:
4829 name = ".gnu.version";
4830 get_vma:
4831 o = bfd_get_section_by_name (abfd, name);
4832 BFD_ASSERT (o != NULL);
4833 dyn.d_un.d_ptr = o->vma;
4834 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4835 break;
4837 case DT_REL:
4838 case DT_RELA:
4839 case DT_RELSZ:
4840 case DT_RELASZ:
4841 if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
4842 type = SHT_REL;
4843 else
4844 type = SHT_RELA;
4845 dyn.d_un.d_val = 0;
4846 for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
4848 Elf_Internal_Shdr *hdr;
4850 hdr = elf_elfsections (abfd)[i];
4851 if (hdr->sh_type == type
4852 && (hdr->sh_flags & SHF_ALLOC) != 0)
4854 if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
4855 dyn.d_un.d_val += hdr->sh_size;
4856 else
4858 if (dyn.d_un.d_val == 0
4859 || hdr->sh_addr < dyn.d_un.d_val)
4860 dyn.d_un.d_val = hdr->sh_addr;
4864 elf_swap_dyn_out (dynobj, &dyn, dyncon);
4865 break;
4870 /* If we have created any dynamic sections, then output them. */
4871 if (dynobj != NULL)
4873 if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
4874 goto error_return;
4876 for (o = dynobj->sections; o != NULL; o = o->next)
4878 if ((o->flags & SEC_HAS_CONTENTS) == 0
4879 || o->_raw_size == 0
4880 || o->output_section == bfd_abs_section_ptr)
4881 continue;
4882 if ((o->flags & SEC_LINKER_CREATED) == 0)
4884 /* At this point, we are only interested in sections
4885 created by elf_link_create_dynamic_sections. */
4886 continue;
4888 if ((elf_section_data (o->output_section)->this_hdr.sh_type
4889 != SHT_STRTAB)
4890 || strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
4892 if (! bfd_set_section_contents (abfd, o->output_section,
4893 o->contents, o->output_offset,
4894 o->_raw_size))
4895 goto error_return;
4897 else
4899 file_ptr off;
4901 /* The contents of the .dynstr section are actually in a
4902 stringtab. */
4903 off = elf_section_data (o->output_section)->this_hdr.sh_offset;
4904 if (bfd_seek (abfd, off, SEEK_SET) != 0
4905 || ! _bfd_stringtab_emit (abfd,
4906 elf_hash_table (info)->dynstr))
4907 goto error_return;
4912 /* If we have optimized stabs strings, output them. */
4913 if (elf_hash_table (info)->stab_info != NULL)
4915 if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
4916 goto error_return;
4919 if (finfo.symstrtab != NULL)
4920 _bfd_stringtab_free (finfo.symstrtab);
4921 if (finfo.contents != NULL)
4922 free (finfo.contents);
4923 if (finfo.external_relocs != NULL)
4924 free (finfo.external_relocs);
4925 if (finfo.internal_relocs != NULL)
4926 free (finfo.internal_relocs);
4927 if (finfo.external_syms != NULL)
4928 free (finfo.external_syms);
4929 if (finfo.internal_syms != NULL)
4930 free (finfo.internal_syms);
4931 if (finfo.indices != NULL)
4932 free (finfo.indices);
4933 if (finfo.sections != NULL)
4934 free (finfo.sections);
4935 if (finfo.symbuf != NULL)
4936 free (finfo.symbuf);
4937 for (o = abfd->sections; o != NULL; o = o->next)
4939 if ((o->flags & SEC_RELOC) != 0
4940 && elf_section_data (o)->rel_hashes != NULL)
4941 free (elf_section_data (o)->rel_hashes);
4944 elf_tdata (abfd)->linker = true;
4946 return true;
4948 error_return:
4949 if (finfo.symstrtab != NULL)
4950 _bfd_stringtab_free (finfo.symstrtab);
4951 if (finfo.contents != NULL)
4952 free (finfo.contents);
4953 if (finfo.external_relocs != NULL)
4954 free (finfo.external_relocs);
4955 if (finfo.internal_relocs != NULL)
4956 free (finfo.internal_relocs);
4957 if (finfo.external_syms != NULL)
4958 free (finfo.external_syms);
4959 if (finfo.internal_syms != NULL)
4960 free (finfo.internal_syms);
4961 if (finfo.indices != NULL)
4962 free (finfo.indices);
4963 if (finfo.sections != NULL)
4964 free (finfo.sections);
4965 if (finfo.symbuf != NULL)
4966 free (finfo.symbuf);
4967 for (o = abfd->sections; o != NULL; o = o->next)
4969 if ((o->flags & SEC_RELOC) != 0
4970 && elf_section_data (o)->rel_hashes != NULL)
4971 free (elf_section_data (o)->rel_hashes);
4974 return false;
4977 /* Add a symbol to the output symbol table. */
4979 static boolean
4980 elf_link_output_sym (finfo, name, elfsym, input_sec)
4981 struct elf_final_link_info *finfo;
4982 const char *name;
4983 Elf_Internal_Sym *elfsym;
4984 asection *input_sec;
4986 boolean (*output_symbol_hook) PARAMS ((bfd *,
4987 struct bfd_link_info *info,
4988 const char *,
4989 Elf_Internal_Sym *,
4990 asection *));
4992 output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
4993 elf_backend_link_output_symbol_hook;
4994 if (output_symbol_hook != NULL)
4996 if (! ((*output_symbol_hook)
4997 (finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
4998 return false;
5001 if (name == (const char *) NULL || *name == '\0')
5002 elfsym->st_name = 0;
5003 else if (input_sec->flags & SEC_EXCLUDE)
5004 elfsym->st_name = 0;
5005 else
5007 elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
5008 name, true,
5009 false);
5010 if (elfsym->st_name == (unsigned long) -1)
5011 return false;
5014 if (finfo->symbuf_count >= finfo->symbuf_size)
5016 if (! elf_link_flush_output_syms (finfo))
5017 return false;
5020 elf_swap_symbol_out (finfo->output_bfd, elfsym,
5021 (PTR) (finfo->symbuf + finfo->symbuf_count));
5022 ++finfo->symbuf_count;
5024 ++ bfd_get_symcount (finfo->output_bfd);
5026 return true;
5029 /* Flush the output symbols to the file. */
5031 static boolean
5032 elf_link_flush_output_syms (finfo)
5033 struct elf_final_link_info *finfo;
5035 if (finfo->symbuf_count > 0)
5037 Elf_Internal_Shdr *symtab;
5039 symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
5041 if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
5042 SEEK_SET) != 0
5043 || (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
5044 sizeof (Elf_External_Sym), finfo->output_bfd)
5045 != finfo->symbuf_count * sizeof (Elf_External_Sym)))
5046 return false;
5048 symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
5050 finfo->symbuf_count = 0;
5053 return true;
5056 /* Add an external symbol to the symbol table. This is called from
5057 the hash table traversal routine. When generating a shared object,
5058 we go through the symbol table twice. The first time we output
5059 anything that might have been forced to local scope in a version
5060 script. The second time we output the symbols that are still
5061 global symbols. */
5063 static boolean
5064 elf_link_output_extsym (h, data)
5065 struct elf_link_hash_entry *h;
5066 PTR data;
5068 struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
5069 struct elf_final_link_info *finfo = eoinfo->finfo;
5070 boolean strip;
5071 Elf_Internal_Sym sym;
5072 asection *input_sec;
5074 /* Decide whether to output this symbol in this pass. */
5075 if (eoinfo->localsyms)
5077 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5078 return true;
5080 else
5082 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5083 return true;
5086 /* If we are not creating a shared library, and this symbol is
5087 referenced by a shared library but is not defined anywhere, then
5088 warn that it is undefined. If we do not do this, the runtime
5089 linker will complain that the symbol is undefined when the
5090 program is run. We don't have to worry about symbols that are
5091 referenced by regular files, because we will already have issued
5092 warnings for them. */
5093 if (! finfo->info->relocateable
5094 && ! finfo->info->allow_shlib_undefined
5095 && ! (finfo->info->shared
5096 && !finfo->info->no_undefined)
5097 && h->root.type == bfd_link_hash_undefined
5098 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
5099 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5101 if (! ((*finfo->info->callbacks->undefined_symbol)
5102 (finfo->info, h->root.root.string, h->root.u.undef.abfd,
5103 (asection *) NULL, 0, true)))
5105 eoinfo->failed = true;
5106 return false;
5110 /* We don't want to output symbols that have never been mentioned by
5111 a regular file, or that we have been told to strip. However, if
5112 h->indx is set to -2, the symbol is used by a reloc and we must
5113 output it. */
5114 if (h->indx == -2)
5115 strip = false;
5116 else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
5117 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
5118 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
5119 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
5120 strip = true;
5121 else if (finfo->info->strip == strip_all
5122 || (finfo->info->strip == strip_some
5123 && bfd_hash_lookup (finfo->info->keep_hash,
5124 h->root.root.string,
5125 false, false) == NULL))
5126 strip = true;
5127 else
5128 strip = false;
5130 /* If we're stripping it, and it's not a dynamic symbol, there's
5131 nothing else to do unless it is a forced local symbol. */
5132 if (strip
5133 && h->dynindx == -1
5134 && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
5135 return true;
5137 sym.st_value = 0;
5138 sym.st_size = h->size;
5139 sym.st_other = h->other;
5140 if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5141 sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
5142 else if (h->root.type == bfd_link_hash_undefweak
5143 || h->root.type == bfd_link_hash_defweak)
5144 sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
5145 else
5146 sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
5148 switch (h->root.type)
5150 default:
5151 case bfd_link_hash_new:
5152 abort ();
5153 return false;
5155 case bfd_link_hash_undefined:
5156 input_sec = bfd_und_section_ptr;
5157 sym.st_shndx = SHN_UNDEF;
5158 break;
5160 case bfd_link_hash_undefweak:
5161 input_sec = bfd_und_section_ptr;
5162 sym.st_shndx = SHN_UNDEF;
5163 break;
5165 case bfd_link_hash_defined:
5166 case bfd_link_hash_defweak:
5168 input_sec = h->root.u.def.section;
5169 if (input_sec->output_section != NULL)
5171 sym.st_shndx =
5172 _bfd_elf_section_from_bfd_section (finfo->output_bfd,
5173 input_sec->output_section);
5174 if (sym.st_shndx == (unsigned short) -1)
5176 (*_bfd_error_handler)
5177 (_("%s: could not find output section %s for input section %s"),
5178 bfd_get_filename (finfo->output_bfd),
5179 input_sec->output_section->name,
5180 input_sec->name);
5181 eoinfo->failed = true;
5182 return false;
5185 /* ELF symbols in relocateable files are section relative,
5186 but in nonrelocateable files they are virtual
5187 addresses. */
5188 sym.st_value = h->root.u.def.value + input_sec->output_offset;
5189 if (! finfo->info->relocateable)
5190 sym.st_value += input_sec->output_section->vma;
5192 else
5194 BFD_ASSERT (input_sec->owner == NULL
5195 || (input_sec->owner->flags & DYNAMIC) != 0);
5196 sym.st_shndx = SHN_UNDEF;
5197 input_sec = bfd_und_section_ptr;
5200 break;
5202 case bfd_link_hash_common:
5203 input_sec = h->root.u.c.p->section;
5204 sym.st_shndx = SHN_COMMON;
5205 sym.st_value = 1 << h->root.u.c.p->alignment_power;
5206 break;
5208 case bfd_link_hash_indirect:
5209 /* These symbols are created by symbol versioning. They point
5210 to the decorated version of the name. For example, if the
5211 symbol foo@@GNU_1.2 is the default, which should be used when
5212 foo is used with no version, then we add an indirect symbol
5213 foo which points to foo@@GNU_1.2. We ignore these symbols,
5214 since the indirected symbol is already in the hash table. */
5215 return true;
5217 case bfd_link_hash_warning:
5218 /* We can't represent these symbols in ELF, although a warning
5219 symbol may have come from a .gnu.warning.SYMBOL section. We
5220 just put the target symbol in the hash table. If the target
5221 symbol does not really exist, don't do anything. */
5222 if (h->root.u.i.link->type == bfd_link_hash_new)
5223 return true;
5224 return (elf_link_output_extsym
5225 ((struct elf_link_hash_entry *) h->root.u.i.link, data));
5228 /* Give the processor backend a chance to tweak the symbol value,
5229 and also to finish up anything that needs to be done for this
5230 symbol. */
5231 if ((h->dynindx != -1
5232 || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
5233 && elf_hash_table (finfo->info)->dynamic_sections_created)
5235 struct elf_backend_data *bed;
5237 bed = get_elf_backend_data (finfo->output_bfd);
5238 if (! ((*bed->elf_backend_finish_dynamic_symbol)
5239 (finfo->output_bfd, finfo->info, h, &sym)))
5241 eoinfo->failed = true;
5242 return false;
5246 /* If we are marking the symbol as undefined, and there are no
5247 non-weak references to this symbol from a regular object, then
5248 mark the symbol as weak undefined; if there are non-weak
5249 references, mark the symbol as strong. We can't do this earlier,
5250 because it might not be marked as undefined until the
5251 finish_dynamic_symbol routine gets through with it. */
5252 if (sym.st_shndx == SHN_UNDEF
5253 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
5254 && (ELF_ST_BIND(sym.st_info) == STB_GLOBAL
5255 || ELF_ST_BIND(sym.st_info) == STB_WEAK))
5257 int bindtype;
5259 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) != 0)
5260 bindtype = STB_GLOBAL;
5261 else
5262 bindtype = STB_WEAK;
5263 sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
5266 /* If a symbol is not defined locally, we clear the visibility
5267 field. */
5268 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5269 sym.st_other ^= ELF_ST_VISIBILITY(sym.st_other);
5271 /* If this symbol should be put in the .dynsym section, then put it
5272 there now. We have already know the symbol index. We also fill
5273 in the entry in the .hash section. */
5274 if (h->dynindx != -1
5275 && elf_hash_table (finfo->info)->dynamic_sections_created)
5277 size_t bucketcount;
5278 size_t bucket;
5279 size_t hash_entry_size;
5280 bfd_byte *bucketpos;
5281 bfd_vma chain;
5283 sym.st_name = h->dynstr_index;
5285 elf_swap_symbol_out (finfo->output_bfd, &sym,
5286 (PTR) (((Elf_External_Sym *)
5287 finfo->dynsym_sec->contents)
5288 + h->dynindx));
5290 bucketcount = elf_hash_table (finfo->info)->bucketcount;
5291 bucket = h->elf_hash_value % bucketcount;
5292 hash_entry_size
5293 = elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
5294 bucketpos = ((bfd_byte *) finfo->hash_sec->contents
5295 + (bucket + 2) * hash_entry_size);
5296 chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
5297 bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
5298 bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
5299 ((bfd_byte *) finfo->hash_sec->contents
5300 + (bucketcount + 2 + h->dynindx) * hash_entry_size));
5302 if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
5304 Elf_Internal_Versym iversym;
5306 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
5308 if (h->verinfo.verdef == NULL)
5309 iversym.vs_vers = 0;
5310 else
5311 iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
5313 else
5315 if (h->verinfo.vertree == NULL)
5316 iversym.vs_vers = 1;
5317 else
5318 iversym.vs_vers = h->verinfo.vertree->vernum + 1;
5321 if ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
5322 iversym.vs_vers |= VERSYM_HIDDEN;
5324 _bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
5325 (((Elf_External_Versym *)
5326 finfo->symver_sec->contents)
5327 + h->dynindx));
5331 /* If we're stripping it, then it was just a dynamic symbol, and
5332 there's nothing else to do. */
5333 if (strip)
5334 return true;
5336 h->indx = bfd_get_symcount (finfo->output_bfd);
5338 if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
5340 eoinfo->failed = true;
5341 return false;
5344 return true;
5347 /* Copy the relocations indicated by the INTERNAL_RELOCS (which
5348 originated from the section given by INPUT_REL_HDR) to the
5349 OUTPUT_BFD. */
5351 static void
5352 elf_link_output_relocs (output_bfd, input_section, input_rel_hdr,
5353 internal_relocs)
5354 bfd *output_bfd;
5355 asection *input_section;
5356 Elf_Internal_Shdr *input_rel_hdr;
5357 Elf_Internal_Rela *internal_relocs;
5359 Elf_Internal_Rela *irela;
5360 Elf_Internal_Rela *irelaend;
5361 Elf_Internal_Shdr *output_rel_hdr;
5362 asection *output_section;
5363 unsigned int *rel_countp = NULL;
5364 struct elf_backend_data *bed;
5366 output_section = input_section->output_section;
5367 output_rel_hdr = NULL;
5369 if (elf_section_data (output_section)->rel_hdr.sh_entsize
5370 == input_rel_hdr->sh_entsize)
5372 output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
5373 rel_countp = &elf_section_data (output_section)->rel_count;
5375 else if (elf_section_data (output_section)->rel_hdr2
5376 && (elf_section_data (output_section)->rel_hdr2->sh_entsize
5377 == input_rel_hdr->sh_entsize))
5379 output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
5380 rel_countp = &elf_section_data (output_section)->rel_count2;
5383 BFD_ASSERT (output_rel_hdr != NULL);
5385 bed = get_elf_backend_data (output_bfd);
5386 irela = internal_relocs;
5387 irelaend = irela + input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5388 if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
5390 Elf_External_Rel *erel;
5392 erel = ((Elf_External_Rel *) output_rel_hdr->contents + *rel_countp);
5393 for (; irela < irelaend; irela++, erel++)
5395 Elf_Internal_Rel irel;
5397 irel.r_offset = irela->r_offset;
5398 irel.r_info = irela->r_info;
5399 BFD_ASSERT (irela->r_addend == 0);
5400 if (bed->s->swap_reloc_out)
5401 (*bed->s->swap_reloc_out) (output_bfd, &irel, (PTR) erel);
5402 else
5403 elf_swap_reloc_out (output_bfd, &irel, erel);
5406 else
5408 Elf_External_Rela *erela;
5410 BFD_ASSERT (input_rel_hdr->sh_entsize
5411 == sizeof (Elf_External_Rela));
5412 erela = ((Elf_External_Rela *) output_rel_hdr->contents + *rel_countp);
5413 for (; irela < irelaend; irela++, erela++)
5414 if (bed->s->swap_reloca_out)
5415 (*bed->s->swap_reloca_out) (output_bfd, irela, (PTR) erela);
5416 else
5417 elf_swap_reloca_out (output_bfd, irela, erela);
5420 /* Bump the counter, so that we know where to add the next set of
5421 relocations. */
5422 *rel_countp += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5425 /* Link an input file into the linker output file. This function
5426 handles all the sections and relocations of the input file at once.
5427 This is so that we only have to read the local symbols once, and
5428 don't have to keep them in memory. */
5430 static boolean
5431 elf_link_input_bfd (finfo, input_bfd)
5432 struct elf_final_link_info *finfo;
5433 bfd *input_bfd;
5435 boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
5436 bfd *, asection *, bfd_byte *,
5437 Elf_Internal_Rela *,
5438 Elf_Internal_Sym *, asection **));
5439 bfd *output_bfd;
5440 Elf_Internal_Shdr *symtab_hdr;
5441 size_t locsymcount;
5442 size_t extsymoff;
5443 Elf_External_Sym *external_syms;
5444 Elf_External_Sym *esym;
5445 Elf_External_Sym *esymend;
5446 Elf_Internal_Sym *isym;
5447 long *pindex;
5448 asection **ppsection;
5449 asection *o;
5450 struct elf_backend_data *bed;
5452 output_bfd = finfo->output_bfd;
5453 bed = get_elf_backend_data (output_bfd);
5454 relocate_section = bed->elf_backend_relocate_section;
5456 /* If this is a dynamic object, we don't want to do anything here:
5457 we don't want the local symbols, and we don't want the section
5458 contents. */
5459 if ((input_bfd->flags & DYNAMIC) != 0)
5460 return true;
5462 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
5463 if (elf_bad_symtab (input_bfd))
5465 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
5466 extsymoff = 0;
5468 else
5470 locsymcount = symtab_hdr->sh_info;
5471 extsymoff = symtab_hdr->sh_info;
5474 /* Read the local symbols. */
5475 if (symtab_hdr->contents != NULL)
5476 external_syms = (Elf_External_Sym *) symtab_hdr->contents;
5477 else if (locsymcount == 0)
5478 external_syms = NULL;
5479 else
5481 external_syms = finfo->external_syms;
5482 if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
5483 || (bfd_read (external_syms, sizeof (Elf_External_Sym),
5484 locsymcount, input_bfd)
5485 != locsymcount * sizeof (Elf_External_Sym)))
5486 return false;
5489 /* Swap in the local symbols and write out the ones which we know
5490 are going into the output file. */
5491 esym = external_syms;
5492 esymend = esym + locsymcount;
5493 isym = finfo->internal_syms;
5494 pindex = finfo->indices;
5495 ppsection = finfo->sections;
5496 for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
5498 asection *isec;
5499 const char *name;
5500 Elf_Internal_Sym osym;
5502 elf_swap_symbol_in (input_bfd, esym, isym);
5503 *pindex = -1;
5505 if (elf_bad_symtab (input_bfd))
5507 if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
5509 *ppsection = NULL;
5510 continue;
5514 if (isym->st_shndx == SHN_UNDEF)
5515 isec = bfd_und_section_ptr;
5516 else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
5517 isec = section_from_elf_index (input_bfd, isym->st_shndx);
5518 else if (isym->st_shndx == SHN_ABS)
5519 isec = bfd_abs_section_ptr;
5520 else if (isym->st_shndx == SHN_COMMON)
5521 isec = bfd_com_section_ptr;
5522 else
5524 /* Who knows? */
5525 isec = NULL;
5528 *ppsection = isec;
5530 /* Don't output the first, undefined, symbol. */
5531 if (esym == external_syms)
5532 continue;
5534 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5536 asection *ksec;
5538 /* Save away all section symbol values. */
5539 if (isec != NULL)
5540 isec->symbol->value = isym->st_value;
5542 /* If this is a discarded link-once section symbol, update
5543 it's value to that of the kept section symbol. The
5544 linker will keep the first of any matching link-once
5545 sections, so we should have already seen it's section
5546 symbol. I trust no-one will have the bright idea of
5547 re-ordering the bfd list... */
5548 if (isec != NULL
5549 && (bfd_get_section_flags (input_bfd, isec) & SEC_LINK_ONCE) != 0
5550 && (ksec = isec->kept_section) != NULL)
5552 isym->st_value = ksec->symbol->value;
5554 /* That put the value right, but the section info is all
5555 wrong. I hope this works. */
5556 isec->output_offset = ksec->output_offset;
5557 isec->output_section = ksec->output_section;
5560 /* We never output section symbols. Instead, we use the
5561 section symbol of the corresponding section in the output
5562 file. */
5563 continue;
5566 /* If we are stripping all symbols, we don't want to output this
5567 one. */
5568 if (finfo->info->strip == strip_all)
5569 continue;
5571 /* If we are discarding all local symbols, we don't want to
5572 output this one. If we are generating a relocateable output
5573 file, then some of the local symbols may be required by
5574 relocs; we output them below as we discover that they are
5575 needed. */
5576 if (finfo->info->discard == discard_all)
5577 continue;
5579 /* If this symbol is defined in a section which we are
5580 discarding, we don't need to keep it, but note that
5581 linker_mark is only reliable for sections that have contents.
5582 For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
5583 as well as linker_mark. */
5584 if (isym->st_shndx > 0
5585 && isym->st_shndx < SHN_LORESERVE
5586 && isec != NULL
5587 && ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
5588 || (! finfo->info->relocateable
5589 && (isec->flags & SEC_EXCLUDE) != 0)))
5590 continue;
5592 /* Get the name of the symbol. */
5593 name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
5594 isym->st_name);
5595 if (name == NULL)
5596 return false;
5598 /* See if we are discarding symbols with this name. */
5599 if ((finfo->info->strip == strip_some
5600 && (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
5601 == NULL))
5602 || (finfo->info->discard == discard_l
5603 && bfd_is_local_label_name (input_bfd, name)))
5604 continue;
5606 /* If we get here, we are going to output this symbol. */
5608 osym = *isym;
5610 /* Adjust the section index for the output file. */
5611 osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
5612 isec->output_section);
5613 if (osym.st_shndx == (unsigned short) -1)
5614 return false;
5616 *pindex = bfd_get_symcount (output_bfd);
5618 /* ELF symbols in relocateable files are section relative, but
5619 in executable files they are virtual addresses. Note that
5620 this code assumes that all ELF sections have an associated
5621 BFD section with a reasonable value for output_offset; below
5622 we assume that they also have a reasonable value for
5623 output_section. Any special sections must be set up to meet
5624 these requirements. */
5625 osym.st_value += isec->output_offset;
5626 if (! finfo->info->relocateable)
5627 osym.st_value += isec->output_section->vma;
5629 if (! elf_link_output_sym (finfo, name, &osym, isec))
5630 return false;
5633 /* Relocate the contents of each section. */
5634 for (o = input_bfd->sections; o != NULL; o = o->next)
5636 bfd_byte *contents;
5638 if (! o->linker_mark)
5640 /* This section was omitted from the link. */
5641 continue;
5644 if ((o->flags & SEC_HAS_CONTENTS) == 0
5645 || (o->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
5646 continue;
5648 if ((o->flags & SEC_LINKER_CREATED) != 0)
5650 /* Section was created by elf_link_create_dynamic_sections
5651 or somesuch. */
5652 continue;
5655 /* Get the contents of the section. They have been cached by a
5656 relaxation routine. Note that o is a section in an input
5657 file, so the contents field will not have been set by any of
5658 the routines which work on output files. */
5659 if (elf_section_data (o)->this_hdr.contents != NULL)
5660 contents = elf_section_data (o)->this_hdr.contents;
5661 else
5663 contents = finfo->contents;
5664 if (! bfd_get_section_contents (input_bfd, o, contents,
5665 (file_ptr) 0, o->_raw_size))
5666 return false;
5669 if ((o->flags & SEC_RELOC) != 0)
5671 Elf_Internal_Rela *internal_relocs;
5673 /* Get the swapped relocs. */
5674 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
5675 (input_bfd, o, finfo->external_relocs,
5676 finfo->internal_relocs, false));
5677 if (internal_relocs == NULL
5678 && o->reloc_count > 0)
5679 return false;
5681 /* Relocate the section by invoking a back end routine.
5683 The back end routine is responsible for adjusting the
5684 section contents as necessary, and (if using Rela relocs
5685 and generating a relocateable output file) adjusting the
5686 reloc addend as necessary.
5688 The back end routine does not have to worry about setting
5689 the reloc address or the reloc symbol index.
5691 The back end routine is given a pointer to the swapped in
5692 internal symbols, and can access the hash table entries
5693 for the external symbols via elf_sym_hashes (input_bfd).
5695 When generating relocateable output, the back end routine
5696 must handle STB_LOCAL/STT_SECTION symbols specially. The
5697 output symbol is going to be a section symbol
5698 corresponding to the output section, which will require
5699 the addend to be adjusted. */
5701 if (! (*relocate_section) (output_bfd, finfo->info,
5702 input_bfd, o, contents,
5703 internal_relocs,
5704 finfo->internal_syms,
5705 finfo->sections))
5706 return false;
5708 if (finfo->info->relocateable || finfo->info->emitrelocations)
5710 Elf_Internal_Rela *irela;
5711 Elf_Internal_Rela *irelaend;
5712 struct elf_link_hash_entry **rel_hash;
5713 Elf_Internal_Shdr *input_rel_hdr;
5715 /* Adjust the reloc addresses and symbol indices. */
5717 irela = internal_relocs;
5718 irelaend =
5719 irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
5720 rel_hash = (elf_section_data (o->output_section)->rel_hashes
5721 + elf_section_data (o->output_section)->rel_count
5722 + elf_section_data (o->output_section)->rel_count2);
5723 for (; irela < irelaend; irela++, rel_hash++)
5725 unsigned long r_symndx;
5726 Elf_Internal_Sym *isym;
5727 asection *sec;
5729 irela->r_offset += o->output_offset;
5731 /* Relocs in an executable have to be virtual addresses. */
5732 if (finfo->info->emitrelocations)
5733 irela->r_offset += o->output_section->vma;
5735 r_symndx = ELF_R_SYM (irela->r_info);
5737 if (r_symndx == 0)
5738 continue;
5740 if (r_symndx >= locsymcount
5741 || (elf_bad_symtab (input_bfd)
5742 && finfo->sections[r_symndx] == NULL))
5744 struct elf_link_hash_entry *rh;
5745 long indx;
5747 /* This is a reloc against a global symbol. We
5748 have not yet output all the local symbols, so
5749 we do not know the symbol index of any global
5750 symbol. We set the rel_hash entry for this
5751 reloc to point to the global hash table entry
5752 for this symbol. The symbol index is then
5753 set at the end of elf_bfd_final_link. */
5754 indx = r_symndx - extsymoff;
5755 rh = elf_sym_hashes (input_bfd)[indx];
5756 while (rh->root.type == bfd_link_hash_indirect
5757 || rh->root.type == bfd_link_hash_warning)
5758 rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
5760 /* Setting the index to -2 tells
5761 elf_link_output_extsym that this symbol is
5762 used by a reloc. */
5763 BFD_ASSERT (rh->indx < 0);
5764 rh->indx = -2;
5766 *rel_hash = rh;
5768 continue;
5771 /* This is a reloc against a local symbol. */
5773 *rel_hash = NULL;
5774 isym = finfo->internal_syms + r_symndx;
5775 sec = finfo->sections[r_symndx];
5776 if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
5778 /* I suppose the backend ought to fill in the
5779 section of any STT_SECTION symbol against a
5780 processor specific section. If we have
5781 discarded a section, the output_section will
5782 be the absolute section. */
5783 if (sec != NULL
5784 && (bfd_is_abs_section (sec)
5785 || (sec->output_section != NULL
5786 && bfd_is_abs_section (sec->output_section))))
5787 r_symndx = 0;
5788 else if (sec == NULL || sec->owner == NULL)
5790 bfd_set_error (bfd_error_bad_value);
5791 return false;
5793 else
5795 r_symndx = sec->output_section->target_index;
5796 BFD_ASSERT (r_symndx != 0);
5799 else
5801 if (finfo->indices[r_symndx] == -1)
5803 unsigned long link;
5804 const char *name;
5805 asection *osec;
5807 if (finfo->info->strip == strip_all)
5809 /* You can't do ld -r -s. */
5810 bfd_set_error (bfd_error_invalid_operation);
5811 return false;
5814 /* This symbol was skipped earlier, but
5815 since it is needed by a reloc, we
5816 must output it now. */
5817 link = symtab_hdr->sh_link;
5818 name = bfd_elf_string_from_elf_section (input_bfd,
5819 link,
5820 isym->st_name);
5821 if (name == NULL)
5822 return false;
5824 osec = sec->output_section;
5825 isym->st_shndx =
5826 _bfd_elf_section_from_bfd_section (output_bfd,
5827 osec);
5828 if (isym->st_shndx == (unsigned short) -1)
5829 return false;
5831 isym->st_value += sec->output_offset;
5832 if (! finfo->info->relocateable)
5833 isym->st_value += osec->vma;
5835 finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
5837 if (! elf_link_output_sym (finfo, name, isym, sec))
5838 return false;
5841 r_symndx = finfo->indices[r_symndx];
5844 irela->r_info = ELF_R_INFO (r_symndx,
5845 ELF_R_TYPE (irela->r_info));
5848 /* Swap out the relocs. */
5849 input_rel_hdr = &elf_section_data (o)->rel_hdr;
5850 elf_link_output_relocs (output_bfd, o,
5851 input_rel_hdr,
5852 internal_relocs);
5853 internal_relocs
5854 += input_rel_hdr->sh_size / input_rel_hdr->sh_entsize;
5855 input_rel_hdr = elf_section_data (o)->rel_hdr2;
5856 if (input_rel_hdr)
5857 elf_link_output_relocs (output_bfd, o,
5858 input_rel_hdr,
5859 internal_relocs);
5863 /* Write out the modified section contents. */
5864 if (elf_section_data (o)->stab_info == NULL)
5866 if (! (o->flags & SEC_EXCLUDE) &&
5867 ! bfd_set_section_contents (output_bfd, o->output_section,
5868 contents, o->output_offset,
5869 (o->_cooked_size != 0
5870 ? o->_cooked_size
5871 : o->_raw_size)))
5872 return false;
5874 else
5876 if (! (_bfd_write_section_stabs
5877 (output_bfd, &elf_hash_table (finfo->info)->stab_info,
5878 o, &elf_section_data (o)->stab_info, contents)))
5879 return false;
5883 return true;
5886 /* Generate a reloc when linking an ELF file. This is a reloc
5887 requested by the linker, and does come from any input file. This
5888 is used to build constructor and destructor tables when linking
5889 with -Ur. */
5891 static boolean
5892 elf_reloc_link_order (output_bfd, info, output_section, link_order)
5893 bfd *output_bfd;
5894 struct bfd_link_info *info;
5895 asection *output_section;
5896 struct bfd_link_order *link_order;
5898 reloc_howto_type *howto;
5899 long indx;
5900 bfd_vma offset;
5901 bfd_vma addend;
5902 struct elf_link_hash_entry **rel_hash_ptr;
5903 Elf_Internal_Shdr *rel_hdr;
5904 struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
5906 howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
5907 if (howto == NULL)
5909 bfd_set_error (bfd_error_bad_value);
5910 return false;
5913 addend = link_order->u.reloc.p->addend;
5915 /* Figure out the symbol index. */
5916 rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
5917 + elf_section_data (output_section)->rel_count
5918 + elf_section_data (output_section)->rel_count2);
5919 if (link_order->type == bfd_section_reloc_link_order)
5921 indx = link_order->u.reloc.p->u.section->target_index;
5922 BFD_ASSERT (indx != 0);
5923 *rel_hash_ptr = NULL;
5925 else
5927 struct elf_link_hash_entry *h;
5929 /* Treat a reloc against a defined symbol as though it were
5930 actually against the section. */
5931 h = ((struct elf_link_hash_entry *)
5932 bfd_wrapped_link_hash_lookup (output_bfd, info,
5933 link_order->u.reloc.p->u.name,
5934 false, false, true));
5935 if (h != NULL
5936 && (h->root.type == bfd_link_hash_defined
5937 || h->root.type == bfd_link_hash_defweak))
5939 asection *section;
5941 section = h->root.u.def.section;
5942 indx = section->output_section->target_index;
5943 *rel_hash_ptr = NULL;
5944 /* It seems that we ought to add the symbol value to the
5945 addend here, but in practice it has already been added
5946 because it was passed to constructor_callback. */
5947 addend += section->output_section->vma + section->output_offset;
5949 else if (h != NULL)
5951 /* Setting the index to -2 tells elf_link_output_extsym that
5952 this symbol is used by a reloc. */
5953 h->indx = -2;
5954 *rel_hash_ptr = h;
5955 indx = 0;
5957 else
5959 if (! ((*info->callbacks->unattached_reloc)
5960 (info, link_order->u.reloc.p->u.name, (bfd *) NULL,
5961 (asection *) NULL, (bfd_vma) 0)))
5962 return false;
5963 indx = 0;
5967 /* If this is an inplace reloc, we must write the addend into the
5968 object file. */
5969 if (howto->partial_inplace && addend != 0)
5971 bfd_size_type size;
5972 bfd_reloc_status_type rstat;
5973 bfd_byte *buf;
5974 boolean ok;
5976 size = bfd_get_reloc_size (howto);
5977 buf = (bfd_byte *) bfd_zmalloc (size);
5978 if (buf == (bfd_byte *) NULL)
5979 return false;
5980 rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
5981 switch (rstat)
5983 case bfd_reloc_ok:
5984 break;
5985 default:
5986 case bfd_reloc_outofrange:
5987 abort ();
5988 case bfd_reloc_overflow:
5989 if (! ((*info->callbacks->reloc_overflow)
5990 (info,
5991 (link_order->type == bfd_section_reloc_link_order
5992 ? bfd_section_name (output_bfd,
5993 link_order->u.reloc.p->u.section)
5994 : link_order->u.reloc.p->u.name),
5995 howto->name, addend, (bfd *) NULL, (asection *) NULL,
5996 (bfd_vma) 0)))
5998 free (buf);
5999 return false;
6001 break;
6003 ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
6004 (file_ptr) link_order->offset, size);
6005 free (buf);
6006 if (! ok)
6007 return false;
6010 /* The address of a reloc is relative to the section in a
6011 relocateable file, and is a virtual address in an executable
6012 file. */
6013 offset = link_order->offset;
6014 if (! info->relocateable)
6015 offset += output_section->vma;
6017 rel_hdr = &elf_section_data (output_section)->rel_hdr;
6019 if (rel_hdr->sh_type == SHT_REL)
6021 Elf_Internal_Rel irel;
6022 Elf_External_Rel *erel;
6024 irel.r_offset = offset;
6025 irel.r_info = ELF_R_INFO (indx, howto->type);
6026 erel = ((Elf_External_Rel *) rel_hdr->contents
6027 + elf_section_data (output_section)->rel_count);
6028 if (bed->s->swap_reloc_out)
6029 (*bed->s->swap_reloc_out) (output_bfd, &irel, (bfd_byte *) erel);
6030 else
6031 elf_swap_reloc_out (output_bfd, &irel, erel);
6033 else
6035 Elf_Internal_Rela irela;
6036 Elf_External_Rela *erela;
6038 irela.r_offset = offset;
6039 irela.r_info = ELF_R_INFO (indx, howto->type);
6040 irela.r_addend = addend;
6041 erela = ((Elf_External_Rela *) rel_hdr->contents
6042 + elf_section_data (output_section)->rel_count);
6043 if (bed->s->swap_reloca_out)
6044 (*bed->s->swap_reloca_out) (output_bfd, &irela, (bfd_byte *) erela);
6045 else
6046 elf_swap_reloca_out (output_bfd, &irela, erela);
6049 ++elf_section_data (output_section)->rel_count;
6051 return true;
6054 /* Allocate a pointer to live in a linker created section. */
6056 boolean
6057 elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
6058 bfd *abfd;
6059 struct bfd_link_info *info;
6060 elf_linker_section_t *lsect;
6061 struct elf_link_hash_entry *h;
6062 const Elf_Internal_Rela *rel;
6064 elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
6065 elf_linker_section_pointers_t *linker_section_ptr;
6066 unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
6068 BFD_ASSERT (lsect != NULL);
6070 /* Is this a global symbol? */
6071 if (h != NULL)
6073 /* Has this symbol already been allocated, if so, our work is done */
6074 if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6075 rel->r_addend,
6076 lsect->which))
6077 return true;
6079 ptr_linker_section_ptr = &h->linker_section_pointer;
6080 /* Make sure this symbol is output as a dynamic symbol. */
6081 if (h->dynindx == -1)
6083 if (! elf_link_record_dynamic_symbol (info, h))
6084 return false;
6087 if (lsect->rel_section)
6088 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
6091 else /* Allocation of a pointer to a local symbol */
6093 elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
6095 /* Allocate a table to hold the local symbols if first time */
6096 if (!ptr)
6098 unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
6099 register unsigned int i;
6101 ptr = (elf_linker_section_pointers_t **)
6102 bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
6104 if (!ptr)
6105 return false;
6107 elf_local_ptr_offsets (abfd) = ptr;
6108 for (i = 0; i < num_symbols; i++)
6109 ptr[i] = (elf_linker_section_pointers_t *)0;
6112 /* Has this symbol already been allocated, if so, our work is done */
6113 if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
6114 rel->r_addend,
6115 lsect->which))
6116 return true;
6118 ptr_linker_section_ptr = &ptr[r_symndx];
6120 if (info->shared)
6122 /* If we are generating a shared object, we need to
6123 output a R_<xxx>_RELATIVE reloc so that the
6124 dynamic linker can adjust this GOT entry. */
6125 BFD_ASSERT (lsect->rel_section != NULL);
6126 lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
6130 /* Allocate space for a pointer in the linker section, and allocate a new pointer record
6131 from internal memory. */
6132 BFD_ASSERT (ptr_linker_section_ptr != NULL);
6133 linker_section_ptr = (elf_linker_section_pointers_t *)
6134 bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
6136 if (!linker_section_ptr)
6137 return false;
6139 linker_section_ptr->next = *ptr_linker_section_ptr;
6140 linker_section_ptr->addend = rel->r_addend;
6141 linker_section_ptr->which = lsect->which;
6142 linker_section_ptr->written_address_p = false;
6143 *ptr_linker_section_ptr = linker_section_ptr;
6145 #if 0
6146 if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
6148 linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
6149 lsect->hole_offset += ARCH_SIZE / 8;
6150 lsect->sym_offset += ARCH_SIZE / 8;
6151 if (lsect->sym_hash) /* Bump up symbol value if needed */
6153 lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
6154 #ifdef DEBUG
6155 fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
6156 lsect->sym_hash->root.root.string,
6157 (long)ARCH_SIZE / 8,
6158 (long)lsect->sym_hash->root.u.def.value);
6159 #endif
6162 else
6163 #endif
6164 linker_section_ptr->offset = lsect->section->_raw_size;
6166 lsect->section->_raw_size += ARCH_SIZE / 8;
6168 #ifdef DEBUG
6169 fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
6170 lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
6171 #endif
6173 return true;
6176 #if ARCH_SIZE==64
6177 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
6178 #endif
6179 #if ARCH_SIZE==32
6180 #define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
6181 #endif
6183 /* Fill in the address for a pointer generated in alinker section. */
6185 bfd_vma
6186 elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
6187 bfd *output_bfd;
6188 bfd *input_bfd;
6189 struct bfd_link_info *info;
6190 elf_linker_section_t *lsect;
6191 struct elf_link_hash_entry *h;
6192 bfd_vma relocation;
6193 const Elf_Internal_Rela *rel;
6194 int relative_reloc;
6196 elf_linker_section_pointers_t *linker_section_ptr;
6198 BFD_ASSERT (lsect != NULL);
6200 if (h != NULL) /* global symbol */
6202 linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
6203 rel->r_addend,
6204 lsect->which);
6206 BFD_ASSERT (linker_section_ptr != NULL);
6208 if (! elf_hash_table (info)->dynamic_sections_created
6209 || (info->shared
6210 && info->symbolic
6211 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
6213 /* This is actually a static link, or it is a
6214 -Bsymbolic link and the symbol is defined
6215 locally. We must initialize this entry in the
6216 global section.
6218 When doing a dynamic link, we create a .rela.<xxx>
6219 relocation entry to initialize the value. This
6220 is done in the finish_dynamic_symbol routine. */
6221 if (!linker_section_ptr->written_address_p)
6223 linker_section_ptr->written_address_p = true;
6224 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6225 lsect->section->contents + linker_section_ptr->offset);
6229 else /* local symbol */
6231 unsigned long r_symndx = ELF_R_SYM (rel->r_info);
6232 BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
6233 BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
6234 linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
6235 rel->r_addend,
6236 lsect->which);
6238 BFD_ASSERT (linker_section_ptr != NULL);
6240 /* Write out pointer if it hasn't been rewritten out before */
6241 if (!linker_section_ptr->written_address_p)
6243 linker_section_ptr->written_address_p = true;
6244 bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
6245 lsect->section->contents + linker_section_ptr->offset);
6247 if (info->shared)
6249 asection *srel = lsect->rel_section;
6250 Elf_Internal_Rela outrel;
6252 /* We need to generate a relative reloc for the dynamic linker. */
6253 if (!srel)
6254 lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
6255 lsect->rel_name);
6257 BFD_ASSERT (srel != NULL);
6259 outrel.r_offset = (lsect->section->output_section->vma
6260 + lsect->section->output_offset
6261 + linker_section_ptr->offset);
6262 outrel.r_info = ELF_R_INFO (0, relative_reloc);
6263 outrel.r_addend = 0;
6264 elf_swap_reloca_out (output_bfd, &outrel,
6265 (((Elf_External_Rela *)
6266 lsect->section->contents)
6267 + elf_section_data (lsect->section)->rel_count));
6268 ++elf_section_data (lsect->section)->rel_count;
6273 relocation = (lsect->section->output_offset
6274 + linker_section_ptr->offset
6275 - lsect->hole_offset
6276 - lsect->sym_offset);
6278 #ifdef DEBUG
6279 fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
6280 lsect->name, (long)relocation, (long)relocation);
6281 #endif
6283 /* Subtract out the addend, because it will get added back in by the normal
6284 processing. */
6285 return relocation - linker_section_ptr->addend;
6288 /* Garbage collect unused sections. */
6290 static boolean elf_gc_mark
6291 PARAMS ((struct bfd_link_info *info, asection *sec,
6292 asection * (*gc_mark_hook)
6293 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6294 struct elf_link_hash_entry *, Elf_Internal_Sym *))));
6296 static boolean elf_gc_sweep
6297 PARAMS ((struct bfd_link_info *info,
6298 boolean (*gc_sweep_hook)
6299 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6300 const Elf_Internal_Rela *relocs))));
6302 static boolean elf_gc_sweep_symbol
6303 PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
6305 static boolean elf_gc_allocate_got_offsets
6306 PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
6308 static boolean elf_gc_propagate_vtable_entries_used
6309 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6311 static boolean elf_gc_smash_unused_vtentry_relocs
6312 PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
6314 /* The mark phase of garbage collection. For a given section, mark
6315 it, and all the sections which define symbols to which it refers. */
6317 static boolean
6318 elf_gc_mark (info, sec, gc_mark_hook)
6319 struct bfd_link_info *info;
6320 asection *sec;
6321 asection * (*gc_mark_hook)
6322 PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
6323 struct elf_link_hash_entry *, Elf_Internal_Sym *));
6325 boolean ret = true;
6327 sec->gc_mark = 1;
6329 /* Look through the section relocs. */
6331 if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
6333 Elf_Internal_Rela *relstart, *rel, *relend;
6334 Elf_Internal_Shdr *symtab_hdr;
6335 struct elf_link_hash_entry **sym_hashes;
6336 size_t nlocsyms;
6337 size_t extsymoff;
6338 Elf_External_Sym *locsyms, *freesyms = NULL;
6339 bfd *input_bfd = sec->owner;
6340 struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
6342 /* GCFIXME: how to arrange so that relocs and symbols are not
6343 reread continually? */
6345 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
6346 sym_hashes = elf_sym_hashes (input_bfd);
6348 /* Read the local symbols. */
6349 if (elf_bad_symtab (input_bfd))
6351 nlocsyms = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6352 extsymoff = 0;
6354 else
6355 extsymoff = nlocsyms = symtab_hdr->sh_info;
6356 if (symtab_hdr->contents)
6357 locsyms = (Elf_External_Sym *) symtab_hdr->contents;
6358 else if (nlocsyms == 0)
6359 locsyms = NULL;
6360 else
6362 locsyms = freesyms =
6363 bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
6364 if (freesyms == NULL
6365 || bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
6366 || (bfd_read (locsyms, sizeof (Elf_External_Sym),
6367 nlocsyms, input_bfd)
6368 != nlocsyms * sizeof (Elf_External_Sym)))
6370 ret = false;
6371 goto out1;
6375 /* Read the relocations. */
6376 relstart = (NAME(_bfd_elf,link_read_relocs)
6377 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
6378 info->keep_memory));
6379 if (relstart == NULL)
6381 ret = false;
6382 goto out1;
6384 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6386 for (rel = relstart; rel < relend; rel++)
6388 unsigned long r_symndx;
6389 asection *rsec;
6390 struct elf_link_hash_entry *h;
6391 Elf_Internal_Sym s;
6393 r_symndx = ELF_R_SYM (rel->r_info);
6394 if (r_symndx == 0)
6395 continue;
6397 if (elf_bad_symtab (sec->owner))
6399 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6400 if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
6401 rsec = (*gc_mark_hook) (sec->owner, info, rel, NULL, &s);
6402 else
6404 h = sym_hashes[r_symndx - extsymoff];
6405 rsec = (*gc_mark_hook) (sec->owner, info, rel, h, NULL);
6408 else if (r_symndx >= nlocsyms)
6410 h = sym_hashes[r_symndx - extsymoff];
6411 rsec = (*gc_mark_hook) (sec->owner, info, rel, h, NULL);
6413 else
6415 elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
6416 rsec = (*gc_mark_hook) (sec->owner, info, rel, NULL, &s);
6419 if (rsec && !rsec->gc_mark)
6420 if (!elf_gc_mark (info, rsec, gc_mark_hook))
6422 ret = false;
6423 goto out2;
6427 out2:
6428 if (!info->keep_memory)
6429 free (relstart);
6430 out1:
6431 if (freesyms)
6432 free (freesyms);
6435 return ret;
6438 /* The sweep phase of garbage collection. Remove all garbage sections. */
6440 static boolean
6441 elf_gc_sweep (info, gc_sweep_hook)
6442 struct bfd_link_info *info;
6443 boolean (*gc_sweep_hook)
6444 PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
6445 const Elf_Internal_Rela *relocs));
6447 bfd *sub;
6449 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6451 asection *o;
6453 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6454 continue;
6456 for (o = sub->sections; o != NULL; o = o->next)
6458 /* Keep special sections. Keep .debug sections. */
6459 if ((o->flags & SEC_LINKER_CREATED)
6460 || (o->flags & SEC_DEBUGGING))
6461 o->gc_mark = 1;
6463 if (o->gc_mark)
6464 continue;
6466 /* Skip sweeping sections already excluded. */
6467 if (o->flags & SEC_EXCLUDE)
6468 continue;
6470 /* Since this is early in the link process, it is simple
6471 to remove a section from the output. */
6472 o->flags |= SEC_EXCLUDE;
6474 /* But we also have to update some of the relocation
6475 info we collected before. */
6476 if (gc_sweep_hook
6477 && (o->flags & SEC_RELOC) && o->reloc_count > 0)
6479 Elf_Internal_Rela *internal_relocs;
6480 boolean r;
6482 internal_relocs = (NAME(_bfd_elf,link_read_relocs)
6483 (o->owner, o, NULL, NULL, info->keep_memory));
6484 if (internal_relocs == NULL)
6485 return false;
6487 r = (*gc_sweep_hook) (o->owner, info, o, internal_relocs);
6489 if (!info->keep_memory)
6490 free (internal_relocs);
6492 if (!r)
6493 return false;
6498 /* Remove the symbols that were in the swept sections from the dynamic
6499 symbol table. GCFIXME: Anyone know how to get them out of the
6500 static symbol table as well? */
6502 int i = 0;
6504 elf_link_hash_traverse (elf_hash_table (info),
6505 elf_gc_sweep_symbol,
6506 (PTR) &i);
6508 elf_hash_table (info)->dynsymcount = i;
6511 return true;
6514 /* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
6516 static boolean
6517 elf_gc_sweep_symbol (h, idxptr)
6518 struct elf_link_hash_entry *h;
6519 PTR idxptr;
6521 int *idx = (int *) idxptr;
6523 if (h->dynindx != -1
6524 && ((h->root.type != bfd_link_hash_defined
6525 && h->root.type != bfd_link_hash_defweak)
6526 || h->root.u.def.section->gc_mark))
6527 h->dynindx = (*idx)++;
6529 return true;
6532 /* Propogate collected vtable information. This is called through
6533 elf_link_hash_traverse. */
6535 static boolean
6536 elf_gc_propagate_vtable_entries_used (h, okp)
6537 struct elf_link_hash_entry *h;
6538 PTR okp;
6540 /* Those that are not vtables. */
6541 if (h->vtable_parent == NULL)
6542 return true;
6544 /* Those vtables that do not have parents, we cannot merge. */
6545 if (h->vtable_parent == (struct elf_link_hash_entry *) -1)
6546 return true;
6548 /* If we've already been done, exit. */
6549 if (h->vtable_entries_used && h->vtable_entries_used[-1])
6550 return true;
6552 /* Make sure the parent's table is up to date. */
6553 elf_gc_propagate_vtable_entries_used (h->vtable_parent, okp);
6555 if (h->vtable_entries_used == NULL)
6557 /* None of this table's entries were referenced. Re-use the
6558 parent's table. */
6559 h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
6560 h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
6562 else
6564 size_t n;
6565 boolean *cu, *pu;
6567 /* Or the parent's entries into ours. */
6568 cu = h->vtable_entries_used;
6569 cu[-1] = true;
6570 pu = h->vtable_parent->vtable_entries_used;
6571 if (pu != NULL)
6573 n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
6574 while (--n != 0)
6576 if (*pu) *cu = true;
6577 pu++, cu++;
6582 return true;
6585 static boolean
6586 elf_gc_smash_unused_vtentry_relocs (h, okp)
6587 struct elf_link_hash_entry *h;
6588 PTR okp;
6590 asection *sec;
6591 bfd_vma hstart, hend;
6592 Elf_Internal_Rela *relstart, *relend, *rel;
6593 struct elf_backend_data *bed;
6595 /* Take care of both those symbols that do not describe vtables as
6596 well as those that are not loaded. */
6597 if (h->vtable_parent == NULL)
6598 return true;
6600 BFD_ASSERT (h->root.type == bfd_link_hash_defined
6601 || h->root.type == bfd_link_hash_defweak);
6603 sec = h->root.u.def.section;
6604 hstart = h->root.u.def.value;
6605 hend = hstart + h->size;
6607 relstart = (NAME(_bfd_elf,link_read_relocs)
6608 (sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
6609 if (!relstart)
6610 return *(boolean *)okp = false;
6611 bed = get_elf_backend_data (sec->owner);
6612 relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
6614 for (rel = relstart; rel < relend; ++rel)
6615 if (rel->r_offset >= hstart && rel->r_offset < hend)
6617 /* If the entry is in use, do nothing. */
6618 if (h->vtable_entries_used
6619 && (rel->r_offset - hstart) < h->vtable_entries_size)
6621 bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
6622 if (h->vtable_entries_used[entry])
6623 continue;
6625 /* Otherwise, kill it. */
6626 rel->r_offset = rel->r_info = rel->r_addend = 0;
6629 return true;
6632 /* Do mark and sweep of unused sections. */
6634 boolean
6635 elf_gc_sections (abfd, info)
6636 bfd *abfd;
6637 struct bfd_link_info *info;
6639 boolean ok = true;
6640 bfd *sub;
6641 asection * (*gc_mark_hook)
6642 PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
6643 struct elf_link_hash_entry *h, Elf_Internal_Sym *));
6645 if (!get_elf_backend_data (abfd)->can_gc_sections
6646 || info->relocateable || info->emitrelocations
6647 || elf_hash_table (info)->dynamic_sections_created)
6648 return true;
6650 /* Apply transitive closure to the vtable entry usage info. */
6651 elf_link_hash_traverse (elf_hash_table (info),
6652 elf_gc_propagate_vtable_entries_used,
6653 (PTR) &ok);
6654 if (!ok)
6655 return false;
6657 /* Kill the vtable relocations that were not used. */
6658 elf_link_hash_traverse (elf_hash_table (info),
6659 elf_gc_smash_unused_vtentry_relocs,
6660 (PTR) &ok);
6661 if (!ok)
6662 return false;
6664 /* Grovel through relocs to find out who stays ... */
6666 gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
6667 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
6669 asection *o;
6671 if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
6672 continue;
6674 for (o = sub->sections; o != NULL; o = o->next)
6676 if (o->flags & SEC_KEEP)
6677 if (!elf_gc_mark (info, o, gc_mark_hook))
6678 return false;
6682 /* ... and mark SEC_EXCLUDE for those that go. */
6683 if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
6684 return false;
6686 return true;
6689 /* Called from check_relocs to record the existance of a VTINHERIT reloc. */
6691 boolean
6692 elf_gc_record_vtinherit (abfd, sec, h, offset)
6693 bfd *abfd;
6694 asection *sec;
6695 struct elf_link_hash_entry *h;
6696 bfd_vma offset;
6698 struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
6699 struct elf_link_hash_entry **search, *child;
6700 bfd_size_type extsymcount;
6702 /* The sh_info field of the symtab header tells us where the
6703 external symbols start. We don't care about the local symbols at
6704 this point. */
6705 extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size/sizeof (Elf_External_Sym);
6706 if (!elf_bad_symtab (abfd))
6707 extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
6709 sym_hashes = elf_sym_hashes (abfd);
6710 sym_hashes_end = sym_hashes + extsymcount;
6712 /* Hunt down the child symbol, which is in this section at the same
6713 offset as the relocation. */
6714 for (search = sym_hashes; search != sym_hashes_end; ++search)
6716 if ((child = *search) != NULL
6717 && (child->root.type == bfd_link_hash_defined
6718 || child->root.type == bfd_link_hash_defweak)
6719 && child->root.u.def.section == sec
6720 && child->root.u.def.value == offset)
6721 goto win;
6724 (*_bfd_error_handler) ("%s: %s+%lu: No symbol found for INHERIT",
6725 bfd_get_filename (abfd), sec->name,
6726 (unsigned long)offset);
6727 bfd_set_error (bfd_error_invalid_operation);
6728 return false;
6730 win:
6731 if (!h)
6733 /* This *should* only be the absolute section. It could potentially
6734 be that someone has defined a non-global vtable though, which
6735 would be bad. It isn't worth paging in the local symbols to be
6736 sure though; that case should simply be handled by the assembler. */
6738 child->vtable_parent = (struct elf_link_hash_entry *) -1;
6740 else
6741 child->vtable_parent = h;
6743 return true;
6746 /* Called from check_relocs to record the existance of a VTENTRY reloc. */
6748 boolean
6749 elf_gc_record_vtentry (abfd, sec, h, addend)
6750 bfd *abfd ATTRIBUTE_UNUSED;
6751 asection *sec ATTRIBUTE_UNUSED;
6752 struct elf_link_hash_entry *h;
6753 bfd_vma addend;
6755 if (addend >= h->vtable_entries_size)
6757 size_t size, bytes;
6758 boolean *ptr = h->vtable_entries_used;
6760 /* While the symbol is undefined, we have to be prepared to handle
6761 a zero size. */
6762 if (h->root.type == bfd_link_hash_undefined)
6763 size = addend;
6764 else
6766 size = h->size;
6767 if (size < addend)
6769 /* Oops! We've got a reference past the defined end of
6770 the table. This is probably a bug -- shall we warn? */
6771 size = addend;
6775 /* Allocate one extra entry for use as a "done" flag for the
6776 consolidation pass. */
6777 bytes = (size / FILE_ALIGN + 1) * sizeof (boolean);
6779 if (ptr)
6781 ptr = bfd_realloc (ptr - 1, bytes);
6783 if (ptr != NULL)
6785 size_t oldbytes;
6787 oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
6788 memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
6791 else
6792 ptr = bfd_zmalloc (bytes);
6794 if (ptr == NULL)
6795 return false;
6797 /* And arrange for that done flag to be at index -1. */
6798 h->vtable_entries_used = ptr + 1;
6799 h->vtable_entries_size = size;
6802 h->vtable_entries_used[addend / FILE_ALIGN] = true;
6804 return true;
6807 /* And an accompanying bit to work out final got entry offsets once
6808 we're done. Should be called from final_link. */
6810 boolean
6811 elf_gc_common_finalize_got_offsets (abfd, info)
6812 bfd *abfd;
6813 struct bfd_link_info *info;
6815 bfd *i;
6816 struct elf_backend_data *bed = get_elf_backend_data (abfd);
6817 bfd_vma gotoff;
6819 /* The GOT offset is relative to the .got section, but the GOT header is
6820 put into the .got.plt section, if the backend uses it. */
6821 if (bed->want_got_plt)
6822 gotoff = 0;
6823 else
6824 gotoff = bed->got_header_size;
6826 /* Do the local .got entries first. */
6827 for (i = info->input_bfds; i; i = i->link_next)
6829 bfd_signed_vma *local_got;
6830 bfd_size_type j, locsymcount;
6831 Elf_Internal_Shdr *symtab_hdr;
6833 if (bfd_get_flavour (i) != bfd_target_elf_flavour)
6834 continue;
6836 local_got = elf_local_got_refcounts (i);
6837 if (!local_got)
6838 continue;
6840 symtab_hdr = &elf_tdata (i)->symtab_hdr;
6841 if (elf_bad_symtab (i))
6842 locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
6843 else
6844 locsymcount = symtab_hdr->sh_info;
6846 for (j = 0; j < locsymcount; ++j)
6848 if (local_got[j] > 0)
6850 local_got[j] = gotoff;
6851 gotoff += ARCH_SIZE / 8;
6853 else
6854 local_got[j] = (bfd_vma) -1;
6858 /* Then the global .got entries. .plt refcounts are handled by
6859 adjust_dynamic_symbol */
6860 elf_link_hash_traverse (elf_hash_table (info),
6861 elf_gc_allocate_got_offsets,
6862 (PTR) &gotoff);
6863 return true;
6866 /* We need a special top-level link routine to convert got reference counts
6867 to real got offsets. */
6869 static boolean
6870 elf_gc_allocate_got_offsets (h, offarg)
6871 struct elf_link_hash_entry *h;
6872 PTR offarg;
6874 bfd_vma *off = (bfd_vma *) offarg;
6876 if (h->got.refcount > 0)
6878 h->got.offset = off[0];
6879 off[0] += ARCH_SIZE / 8;
6881 else
6882 h->got.offset = (bfd_vma) -1;
6884 return true;
6887 /* Many folk need no more in the way of final link than this, once
6888 got entry reference counting is enabled. */
6890 boolean
6891 elf_gc_common_final_link (abfd, info)
6892 bfd *abfd;
6893 struct bfd_link_info *info;
6895 if (!elf_gc_common_finalize_got_offsets (abfd, info))
6896 return false;
6898 /* Invoke the regular ELF backend linker to do all the work. */
6899 return elf_bfd_final_link (abfd, info);
6902 /* This function will be called though elf_link_hash_traverse to store
6903 all hash value of the exported symbols in an array. */
6905 static boolean
6906 elf_collect_hash_codes (h, data)
6907 struct elf_link_hash_entry *h;
6908 PTR data;
6910 unsigned long **valuep = (unsigned long **) data;
6911 const char *name;
6912 char *p;
6913 unsigned long ha;
6914 char *alc = NULL;
6916 /* Ignore indirect symbols. These are added by the versioning code. */
6917 if (h->dynindx == -1)
6918 return true;
6920 name = h->root.root.string;
6921 p = strchr (name, ELF_VER_CHR);
6922 if (p != NULL)
6924 alc = bfd_malloc (p - name + 1);
6925 memcpy (alc, name, p - name);
6926 alc[p - name] = '\0';
6927 name = alc;
6930 /* Compute the hash value. */
6931 ha = bfd_elf_hash (name);
6933 /* Store the found hash value in the array given as the argument. */
6934 *(*valuep)++ = ha;
6936 /* And store it in the struct so that we can put it in the hash table
6937 later. */
6938 h->elf_hash_value = ha;
6940 if (alc != NULL)
6941 free (alc);
6943 return true;