1 /* linker.c -- BFD linker routines
2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
3 2003, 2004, 2005 Free Software Foundation, Inc.
4 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
33 The linker uses three special entry points in the BFD target
34 vector. It is not necessary to write special routines for
35 these entry points when creating a new BFD back end, since
36 generic versions are provided. However, writing them can
37 speed up linking and make it use significantly less runtime
40 The first routine creates a hash table used by the other
41 routines. The second routine adds the symbols from an object
42 file to the hash table. The third routine takes all the
43 object files and links them together to create the output
44 file. These routines are designed so that the linker proper
45 does not need to know anything about the symbols in the object
46 files that it is linking. The linker merely arranges the
47 sections as directed by the linker script and lets BFD handle
48 the details of symbols and relocs.
50 The second routine and third routines are passed a pointer to
51 a <<struct bfd_link_info>> structure (defined in
52 <<bfdlink.h>>) which holds information relevant to the link,
53 including the linker hash table (which was created by the
54 first routine) and a set of callback functions to the linker
57 The generic linker routines are in <<linker.c>>, and use the
58 header file <<genlink.h>>. As of this writing, the only back
59 ends which have implemented versions of these routines are
60 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out
61 routines are used as examples throughout this section.
64 @* Creating a Linker Hash Table::
65 @* Adding Symbols to the Hash Table::
66 @* Performing the Final Link::
70 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions
72 Creating a linker hash table
74 @cindex _bfd_link_hash_table_create in target vector
75 @cindex target vector (_bfd_link_hash_table_create)
76 The linker routines must create a hash table, which must be
77 derived from <<struct bfd_link_hash_table>> described in
78 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to
79 create a derived hash table. This entry point is called using
80 the target vector of the linker output file.
82 The <<_bfd_link_hash_table_create>> entry point must allocate
83 and initialize an instance of the desired hash table. If the
84 back end does not require any additional information to be
85 stored with the entries in the hash table, the entry point may
86 simply create a <<struct bfd_link_hash_table>>. Most likely,
87 however, some additional information will be needed.
89 For example, with each entry in the hash table the a.out
90 linker keeps the index the symbol has in the final output file
91 (this index number is used so that when doing a relocatable
92 link the symbol index used in the output file can be quickly
93 filled in when copying over a reloc). The a.out linker code
94 defines the required structures and functions for a hash table
95 derived from <<struct bfd_link_hash_table>>. The a.out linker
96 hash table is created by the function
97 <<NAME(aout,link_hash_table_create)>>; it simply allocates
98 space for the hash table, initializes it, and returns a
101 When writing the linker routines for a new back end, you will
102 generally not know exactly which fields will be required until
103 you have finished. You should simply create a new hash table
104 which defines no additional fields, and then simply add fields
105 as they become necessary.
108 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions
110 Adding symbols to the hash table
112 @cindex _bfd_link_add_symbols in target vector
113 @cindex target vector (_bfd_link_add_symbols)
114 The linker proper will call the <<_bfd_link_add_symbols>>
115 entry point for each object file or archive which is to be
116 linked (typically these are the files named on the command
117 line, but some may also come from the linker script). The
118 entry point is responsible for examining the file. For an
119 object file, BFD must add any relevant symbol information to
120 the hash table. For an archive, BFD must determine which
121 elements of the archive should be used and adding them to the
124 The a.out version of this entry point is
125 <<NAME(aout,link_add_symbols)>>.
128 @* Differing file formats::
129 @* Adding symbols from an object file::
130 @* Adding symbols from an archive::
134 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table
136 Differing file formats
138 Normally all the files involved in a link will be of the same
139 format, but it is also possible to link together different
140 format object files, and the back end must support that. The
141 <<_bfd_link_add_symbols>> entry point is called via the target
142 vector of the file to be added. This has an important
143 consequence: the function may not assume that the hash table
144 is the type created by the corresponding
145 <<_bfd_link_hash_table_create>> vector. All the
146 <<_bfd_link_add_symbols>> function can assume about the hash
147 table is that it is derived from <<struct
148 bfd_link_hash_table>>.
150 Sometimes the <<_bfd_link_add_symbols>> function must store
151 some information in the hash table entry to be used by the
152 <<_bfd_final_link>> function. In such a case the <<creator>>
153 field of the hash table must be checked to make sure that the
154 hash table was created by an object file of the same format.
156 The <<_bfd_final_link>> routine must be prepared to handle a
157 hash entry without any extra information added by the
158 <<_bfd_link_add_symbols>> function. A hash entry without
159 extra information will also occur when the linker script
160 directs the linker to create a symbol. Note that, regardless
161 of how a hash table entry is added, all the fields will be
162 initialized to some sort of null value by the hash table entry
163 initialization function.
165 See <<ecoff_link_add_externals>> for an example of how to
166 check the <<creator>> field before saving information (in this
167 case, the ECOFF external symbol debugging information) in a
171 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table
173 Adding symbols from an object file
175 When the <<_bfd_link_add_symbols>> routine is passed an object
176 file, it must add all externally visible symbols in that
177 object file to the hash table. The actual work of adding the
178 symbol to the hash table is normally handled by the function
179 <<_bfd_generic_link_add_one_symbol>>. The
180 <<_bfd_link_add_symbols>> routine is responsible for reading
181 all the symbols from the object file and passing the correct
182 information to <<_bfd_generic_link_add_one_symbol>>.
184 The <<_bfd_link_add_symbols>> routine should not use
185 <<bfd_canonicalize_symtab>> to read the symbols. The point of
186 providing this routine is to avoid the overhead of converting
187 the symbols into generic <<asymbol>> structures.
189 @findex _bfd_generic_link_add_one_symbol
190 <<_bfd_generic_link_add_one_symbol>> handles the details of
191 combining common symbols, warning about multiple definitions,
192 and so forth. It takes arguments which describe the symbol to
193 add, notably symbol flags, a section, and an offset. The
194 symbol flags include such things as <<BSF_WEAK>> or
195 <<BSF_INDIRECT>>. The section is a section in the object
196 file, or something like <<bfd_und_section_ptr>> for an undefined
197 symbol or <<bfd_com_section_ptr>> for a common symbol.
199 If the <<_bfd_final_link>> routine is also going to need to
200 read the symbol information, the <<_bfd_link_add_symbols>>
201 routine should save it somewhere attached to the object file
202 BFD. However, the information should only be saved if the
203 <<keep_memory>> field of the <<info>> argument is TRUE, so
204 that the <<-no-keep-memory>> linker switch is effective.
206 The a.out function which adds symbols from an object file is
207 <<aout_link_add_object_symbols>>, and most of the interesting
208 work is in <<aout_link_add_symbols>>. The latter saves
209 pointers to the hash tables entries created by
210 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number,
211 so that the <<_bfd_final_link>> routine does not have to call
212 the hash table lookup routine to locate the entry.
215 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table
217 Adding symbols from an archive
219 When the <<_bfd_link_add_symbols>> routine is passed an
220 archive, it must look through the symbols defined by the
221 archive and decide which elements of the archive should be
222 included in the link. For each such element it must call the
223 <<add_archive_element>> linker callback, and it must add the
224 symbols from the object file to the linker hash table.
226 @findex _bfd_generic_link_add_archive_symbols
227 In most cases the work of looking through the symbols in the
228 archive should be done by the
229 <<_bfd_generic_link_add_archive_symbols>> function. This
230 function builds a hash table from the archive symbol table and
231 looks through the list of undefined symbols to see which
232 elements should be included.
233 <<_bfd_generic_link_add_archive_symbols>> is passed a function
234 to call to make the final decision about adding an archive
235 element to the link and to do the actual work of adding the
236 symbols to the linker hash table.
238 The function passed to
239 <<_bfd_generic_link_add_archive_symbols>> must read the
240 symbols of the archive element and decide whether the archive
241 element should be included in the link. If the element is to
242 be included, the <<add_archive_element>> linker callback
243 routine must be called with the element as an argument, and
244 the elements symbols must be added to the linker hash table
245 just as though the element had itself been passed to the
246 <<_bfd_link_add_symbols>> function.
248 When the a.out <<_bfd_link_add_symbols>> function receives an
249 archive, it calls <<_bfd_generic_link_add_archive_symbols>>
250 passing <<aout_link_check_archive_element>> as the function
251 argument. <<aout_link_check_archive_element>> calls
252 <<aout_link_check_ar_symbols>>. If the latter decides to add
253 the element (an element is only added if it provides a real,
254 non-common, definition for a previously undefined or common
255 symbol) it calls the <<add_archive_element>> callback and then
256 <<aout_link_check_archive_element>> calls
257 <<aout_link_add_symbols>> to actually add the symbols to the
260 The ECOFF back end is unusual in that it does not normally
261 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF
262 archives already contain a hash table of symbols. The ECOFF
263 back end searches the archive itself to avoid the overhead of
264 creating a new hash table.
267 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions
269 Performing the final link
271 @cindex _bfd_link_final_link in target vector
272 @cindex target vector (_bfd_final_link)
273 When all the input files have been processed, the linker calls
274 the <<_bfd_final_link>> entry point of the output BFD. This
275 routine is responsible for producing the final output file,
276 which has several aspects. It must relocate the contents of
277 the input sections and copy the data into the output sections.
278 It must build an output symbol table including any local
279 symbols from the input files and the global symbols from the
280 hash table. When producing relocatable output, it must
281 modify the input relocs and write them into the output file.
282 There may also be object format dependent work to be done.
284 The linker will also call the <<write_object_contents>> entry
285 point when the BFD is closed. The two entry points must work
286 together in order to produce the correct output file.
288 The details of how this works are inevitably dependent upon
289 the specific object file format. The a.out
290 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>.
293 @* Information provided by the linker::
294 @* Relocating the section contents::
295 @* Writing the symbol table::
299 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link
301 Information provided by the linker
303 Before the linker calls the <<_bfd_final_link>> entry point,
304 it sets up some data structures for the function to use.
306 The <<input_bfds>> field of the <<bfd_link_info>> structure
307 will point to a list of all the input files included in the
308 link. These files are linked through the <<link_next>> field
309 of the <<bfd>> structure.
311 Each section in the output file will have a list of
312 <<link_order>> structures attached to the <<link_order_head>>
313 field (the <<link_order>> structure is defined in
314 <<bfdlink.h>>). These structures describe how to create the
315 contents of the output section in terms of the contents of
316 various input sections, fill constants, and, eventually, other
317 types of information. They also describe relocs that must be
318 created by the BFD backend, but do not correspond to any input
319 file; this is used to support -Ur, which builds constructors
320 while generating a relocatable object file.
323 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link
325 Relocating the section contents
327 The <<_bfd_final_link>> function should look through the
328 <<link_order>> structures attached to each section of the
329 output file. Each <<link_order>> structure should either be
330 handled specially, or it should be passed to the function
331 <<_bfd_default_link_order>> which will do the right thing
332 (<<_bfd_default_link_order>> is defined in <<linker.c>>).
334 For efficiency, a <<link_order>> of type
335 <<bfd_indirect_link_order>> whose associated section belongs
336 to a BFD of the same format as the output BFD must be handled
337 specially. This type of <<link_order>> describes part of an
338 output section in terms of a section belonging to one of the
339 input files. The <<_bfd_final_link>> function should read the
340 contents of the section and any associated relocs, apply the
341 relocs to the section contents, and write out the modified
342 section contents. If performing a relocatable link, the
343 relocs themselves must also be modified and written out.
345 @findex _bfd_relocate_contents
346 @findex _bfd_final_link_relocate
347 The functions <<_bfd_relocate_contents>> and
348 <<_bfd_final_link_relocate>> provide some general support for
349 performing the actual relocations, notably overflow checking.
350 Their arguments include information about the symbol the
351 relocation is against and a <<reloc_howto_type>> argument
352 which describes the relocation to perform. These functions
353 are defined in <<reloc.c>>.
355 The a.out function which handles reading, relocating, and
356 writing section contents is <<aout_link_input_section>>. The
357 actual relocation is done in <<aout_link_input_section_std>>
358 and <<aout_link_input_section_ext>>.
361 Writing the symbol table, , Relocating the section contents, Performing the Final Link
363 Writing the symbol table
365 The <<_bfd_final_link>> function must gather all the symbols
366 in the input files and write them out. It must also write out
367 all the symbols in the global hash table. This must be
368 controlled by the <<strip>> and <<discard>> fields of the
369 <<bfd_link_info>> structure.
371 The local symbols of the input files will not have been
372 entered into the linker hash table. The <<_bfd_final_link>>
373 routine must consider each input file and include the symbols
374 in the output file. It may be convenient to do this when
375 looking through the <<link_order>> structures, or it may be
376 done by stepping through the <<input_bfds>> list.
378 The <<_bfd_final_link>> routine must also traverse the global
379 hash table to gather all the externally visible symbols. It
380 is possible that most of the externally visible symbols may be
381 written out when considering the symbols of each input file,
382 but it is still necessary to traverse the hash table since the
383 linker script may have defined some symbols that are not in
384 any of the input files.
386 The <<strip>> field of the <<bfd_link_info>> structure
387 controls which symbols are written out. The possible values
388 are listed in <<bfdlink.h>>. If the value is <<strip_some>>,
389 then the <<keep_hash>> field of the <<bfd_link_info>>
390 structure is a hash table of symbols to keep; each symbol
391 should be looked up in this hash table, and only symbols which
392 are present should be included in the output file.
394 If the <<strip>> field of the <<bfd_link_info>> structure
395 permits local symbols to be written out, the <<discard>> field
396 is used to further controls which local symbols are included
397 in the output file. If the value is <<discard_l>>, then all
398 local symbols which begin with a certain prefix are discarded;
399 this is controlled by the <<bfd_is_local_label_name>> entry point.
401 The a.out backend handles symbols by calling
402 <<aout_link_write_symbols>> on each input BFD and then
403 traversing the global hash table with the function
404 <<aout_link_write_other_symbol>>. It builds a string table
405 while writing out the symbols, which is written to the output
406 file at the end of <<NAME(aout,final_link)>>.
409 static bfd_boolean generic_link_add_object_symbols
410 (bfd *, struct bfd_link_info *, bfd_boolean collect);
411 static bfd_boolean generic_link_add_symbols
412 (bfd *, struct bfd_link_info *, bfd_boolean);
413 static bfd_boolean generic_link_check_archive_element_no_collect
414 (bfd *, struct bfd_link_info *, bfd_boolean *);
415 static bfd_boolean generic_link_check_archive_element_collect
416 (bfd *, struct bfd_link_info *, bfd_boolean *);
417 static bfd_boolean generic_link_check_archive_element
418 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean);
419 static bfd_boolean generic_link_add_symbol_list
420 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **,
422 static bfd_boolean generic_add_output_symbol
423 (bfd *, size_t *psymalloc, asymbol *);
424 static bfd_boolean default_data_link_order
425 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *);
426 static bfd_boolean default_indirect_link_order
427 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *,
430 /* The link hash table structure is defined in bfdlink.h. It provides
431 a base hash table which the backend specific hash tables are built
434 /* Routine to create an entry in the link hash table. */
436 struct bfd_hash_entry *
437 _bfd_link_hash_newfunc (struct bfd_hash_entry *entry,
438 struct bfd_hash_table *table,
441 /* Allocate the structure if it has not already been allocated by a
445 entry = bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry));
450 /* Call the allocation method of the superclass. */
451 entry = bfd_hash_newfunc (entry, table, string);
454 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry;
456 /* Initialize the local fields. */
457 h->type = bfd_link_hash_new;
458 h->u.undef.next = NULL;
464 /* Initialize a link hash table. The BFD argument is the one
465 responsible for creating this table. */
468 _bfd_link_hash_table_init
469 (struct bfd_link_hash_table *table,
471 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
472 struct bfd_hash_table *,
475 table->creator = abfd->xvec;
476 table->undefs = NULL;
477 table->undefs_tail = NULL;
478 table->type = bfd_link_generic_hash_table;
480 return bfd_hash_table_init (&table->table, newfunc);
483 /* Look up a symbol in a link hash table. If follow is TRUE, we
484 follow bfd_link_hash_indirect and bfd_link_hash_warning links to
487 struct bfd_link_hash_entry *
488 bfd_link_hash_lookup (struct bfd_link_hash_table *table,
494 struct bfd_link_hash_entry *ret;
496 ret = ((struct bfd_link_hash_entry *)
497 bfd_hash_lookup (&table->table, string, create, copy));
499 if (follow && ret != NULL)
501 while (ret->type == bfd_link_hash_indirect
502 || ret->type == bfd_link_hash_warning)
509 /* Look up a symbol in the main linker hash table if the symbol might
510 be wrapped. This should only be used for references to an
511 undefined symbol, not for definitions of a symbol. */
513 struct bfd_link_hash_entry *
514 bfd_wrapped_link_hash_lookup (bfd *abfd,
515 struct bfd_link_info *info,
523 if (info->wrap_hash != NULL)
529 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char)
536 #define WRAP "__wrap_"
538 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL)
541 struct bfd_link_hash_entry *h;
543 /* This symbol is being wrapped. We want to replace all
544 references to SYM with references to __wrap_SYM. */
546 amt = strlen (l) + sizeof WRAP + 1;
547 n = bfd_malloc (amt);
555 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow);
563 #define REAL "__real_"
566 && strncmp (l, REAL, sizeof REAL - 1) == 0
567 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1,
568 FALSE, FALSE) != NULL)
571 struct bfd_link_hash_entry *h;
573 /* This is a reference to __real_SYM, where SYM is being
574 wrapped. We want to replace all references to __real_SYM
575 with references to SYM. */
577 amt = strlen (l + sizeof REAL - 1) + 2;
578 n = bfd_malloc (amt);
584 strcat (n, l + sizeof REAL - 1);
585 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow);
593 return bfd_link_hash_lookup (info->hash, string, create, copy, follow);
596 /* Traverse a generic link hash table. The only reason this is not a
597 macro is to do better type checking. This code presumes that an
598 argument passed as a struct bfd_hash_entry * may be caught as a
599 struct bfd_link_hash_entry * with no explicit cast required on the
603 bfd_link_hash_traverse
604 (struct bfd_link_hash_table *table,
605 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *),
608 bfd_hash_traverse (&table->table,
609 (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func,
613 /* Add a symbol to the linker hash table undefs list. */
616 bfd_link_add_undef (struct bfd_link_hash_table *table,
617 struct bfd_link_hash_entry *h)
619 BFD_ASSERT (h->u.undef.next == NULL);
620 if (table->undefs_tail != NULL)
621 table->undefs_tail->u.undef.next = h;
622 if (table->undefs == NULL)
624 table->undefs_tail = h;
627 /* The undefs list was designed so that in normal use we don't need to
628 remove entries. However, if symbols on the list are changed from
629 bfd_link_hash_undefined to either bfd_link_hash_undefweak or
630 bfd_link_hash_new for some reason, then they must be removed from the
631 list. Failure to do so might result in the linker attempting to add
632 the symbol to the list again at a later stage. */
635 bfd_link_repair_undef_list (struct bfd_link_hash_table *table)
637 struct bfd_link_hash_entry **pun;
639 pun = &table->undefs;
642 struct bfd_link_hash_entry *h = *pun;
644 if (h->type == bfd_link_hash_new
645 || h->type == bfd_link_hash_undefweak)
647 *pun = h->u.undef.next;
648 h->u.undef.next = NULL;
649 if (h == table->undefs_tail)
651 if (pun == &table->undefs)
652 table->undefs_tail = NULL;
654 /* pun points at an u.undef.next field. Go back to
655 the start of the link_hash_entry. */
656 table->undefs_tail = (struct bfd_link_hash_entry *)
657 ((char *) pun - ((char *) &h->u.undef.next - (char *) h));
662 pun = &h->u.undef.next;
666 /* Routine to create an entry in a generic link hash table. */
668 struct bfd_hash_entry *
669 _bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry,
670 struct bfd_hash_table *table,
673 /* Allocate the structure if it has not already been allocated by a
678 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry));
683 /* Call the allocation method of the superclass. */
684 entry = _bfd_link_hash_newfunc (entry, table, string);
687 struct generic_link_hash_entry *ret;
689 /* Set local fields. */
690 ret = (struct generic_link_hash_entry *) entry;
691 ret->written = FALSE;
698 /* Create a generic link hash table. */
700 struct bfd_link_hash_table *
701 _bfd_generic_link_hash_table_create (bfd *abfd)
703 struct generic_link_hash_table *ret;
704 bfd_size_type amt = sizeof (struct generic_link_hash_table);
706 ret = bfd_malloc (amt);
709 if (! _bfd_link_hash_table_init (&ret->root, abfd,
710 _bfd_generic_link_hash_newfunc))
719 _bfd_generic_link_hash_table_free (struct bfd_link_hash_table *hash)
721 struct generic_link_hash_table *ret
722 = (struct generic_link_hash_table *) hash;
724 bfd_hash_table_free (&ret->root.table);
728 /* Grab the symbols for an object file when doing a generic link. We
729 store the symbols in the outsymbols field. We need to keep them
730 around for the entire link to ensure that we only read them once.
731 If we read them multiple times, we might wind up with relocs and
732 the hash table pointing to different instances of the symbol
736 generic_link_read_symbols (bfd *abfd)
738 if (bfd_get_outsymbols (abfd) == NULL)
743 symsize = bfd_get_symtab_upper_bound (abfd);
746 bfd_get_outsymbols (abfd) = bfd_alloc (abfd, symsize);
747 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0)
749 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd));
752 bfd_get_symcount (abfd) = symcount;
758 /* Generic function to add symbols to from an object file to the
759 global hash table. This version does not automatically collect
760 constructors by name. */
763 _bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
765 return generic_link_add_symbols (abfd, info, FALSE);
768 /* Generic function to add symbols from an object file to the global
769 hash table. This version automatically collects constructors by
770 name, as the collect2 program does. It should be used for any
771 target which does not provide some other mechanism for setting up
772 constructors and destructors; these are approximately those targets
773 for which gcc uses collect2 and do not support stabs. */
776 _bfd_generic_link_add_symbols_collect (bfd *abfd, struct bfd_link_info *info)
778 return generic_link_add_symbols (abfd, info, TRUE);
781 /* Indicate that we are only retrieving symbol values from this
782 section. We want the symbols to act as though the values in the
783 file are absolute. */
786 _bfd_generic_link_just_syms (asection *sec,
787 struct bfd_link_info *info ATTRIBUTE_UNUSED)
789 sec->output_section = bfd_abs_section_ptr;
790 sec->output_offset = sec->vma;
793 /* Add symbols from an object file to the global hash table. */
796 generic_link_add_symbols (bfd *abfd,
797 struct bfd_link_info *info,
802 switch (bfd_get_format (abfd))
805 ret = generic_link_add_object_symbols (abfd, info, collect);
808 ret = (_bfd_generic_link_add_archive_symbols
811 ? generic_link_check_archive_element_collect
812 : generic_link_check_archive_element_no_collect)));
815 bfd_set_error (bfd_error_wrong_format);
822 /* Add symbols from an object file to the global hash table. */
825 generic_link_add_object_symbols (bfd *abfd,
826 struct bfd_link_info *info,
829 bfd_size_type symcount;
830 struct bfd_symbol **outsyms;
832 if (! generic_link_read_symbols (abfd))
834 symcount = _bfd_generic_link_get_symcount (abfd);
835 outsyms = _bfd_generic_link_get_symbols (abfd);
836 return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect);
839 /* We build a hash table of all symbols defined in an archive. */
841 /* An archive symbol may be defined by multiple archive elements.
842 This linked list is used to hold the elements. */
846 struct archive_list *next;
850 /* An entry in an archive hash table. */
852 struct archive_hash_entry
854 struct bfd_hash_entry root;
855 /* Where the symbol is defined. */
856 struct archive_list *defs;
859 /* An archive hash table itself. */
861 struct archive_hash_table
863 struct bfd_hash_table table;
866 /* Create a new entry for an archive hash table. */
868 static struct bfd_hash_entry *
869 archive_hash_newfunc (struct bfd_hash_entry *entry,
870 struct bfd_hash_table *table,
873 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry;
875 /* Allocate the structure if it has not already been allocated by a
878 ret = bfd_hash_allocate (table, sizeof (struct archive_hash_entry));
882 /* Call the allocation method of the superclass. */
883 ret = ((struct archive_hash_entry *)
884 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
888 /* Initialize the local fields. */
895 /* Initialize an archive hash table. */
898 archive_hash_table_init
899 (struct archive_hash_table *table,
900 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
901 struct bfd_hash_table *,
904 return bfd_hash_table_init (&table->table, newfunc);
907 /* Look up an entry in an archive hash table. */
909 #define archive_hash_lookup(t, string, create, copy) \
910 ((struct archive_hash_entry *) \
911 bfd_hash_lookup (&(t)->table, (string), (create), (copy)))
913 /* Allocate space in an archive hash table. */
915 #define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size))
917 /* Free an archive hash table. */
919 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table)
921 /* Generic function to add symbols from an archive file to the global
922 hash file. This function presumes that the archive symbol table
923 has already been read in (this is normally done by the
924 bfd_check_format entry point). It looks through the undefined and
925 common symbols and searches the archive symbol table for them. If
926 it finds an entry, it includes the associated object file in the
929 The old linker looked through the archive symbol table for
930 undefined symbols. We do it the other way around, looking through
931 undefined symbols for symbols defined in the archive. The
932 advantage of the newer scheme is that we only have to look through
933 the list of undefined symbols once, whereas the old method had to
934 re-search the symbol table each time a new object file was added.
936 The CHECKFN argument is used to see if an object file should be
937 included. CHECKFN should set *PNEEDED to TRUE if the object file
938 should be included, and must also call the bfd_link_info
939 add_archive_element callback function and handle adding the symbols
940 to the global hash table. CHECKFN should only return FALSE if some
941 sort of error occurs.
943 For some formats, such as a.out, it is possible to look through an
944 object file but not actually include it in the link. The
945 archive_pass field in a BFD is used to avoid checking the symbols
946 of an object files too many times. When an object is included in
947 the link, archive_pass is set to -1. If an object is scanned but
948 not included, archive_pass is set to the pass number. The pass
949 number is incremented each time a new object file is included. The
950 pass number is used because when a new object file is included it
951 may create new undefined symbols which cause a previously examined
952 object file to be included. */
955 _bfd_generic_link_add_archive_symbols
957 struct bfd_link_info *info,
958 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *))
962 register carsym *arsym;
964 struct archive_hash_table arsym_hash;
966 struct bfd_link_hash_entry **pundef;
968 if (! bfd_has_map (abfd))
970 /* An empty archive is a special case. */
971 if (bfd_openr_next_archived_file (abfd, NULL) == NULL)
973 bfd_set_error (bfd_error_no_armap);
977 arsyms = bfd_ardata (abfd)->symdefs;
978 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count;
980 /* In order to quickly determine whether an symbol is defined in
981 this archive, we build a hash table of the symbols. */
982 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc))
984 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++)
986 struct archive_hash_entry *arh;
987 struct archive_list *l, **pp;
989 arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE);
992 l = ((struct archive_list *)
993 archive_hash_allocate (&arsym_hash, sizeof (struct archive_list)));
997 for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next)
1003 /* The archive_pass field in the archive itself is used to
1004 initialize PASS, sine we may search the same archive multiple
1006 pass = abfd->archive_pass + 1;
1008 /* New undefined symbols are added to the end of the list, so we
1009 only need to look through it once. */
1010 pundef = &info->hash->undefs;
1011 while (*pundef != NULL)
1013 struct bfd_link_hash_entry *h;
1014 struct archive_hash_entry *arh;
1015 struct archive_list *l;
1019 /* When a symbol is defined, it is not necessarily removed from
1021 if (h->type != bfd_link_hash_undefined
1022 && h->type != bfd_link_hash_common)
1024 /* Remove this entry from the list, for general cleanliness
1025 and because we are going to look through the list again
1026 if we search any more libraries. We can't remove the
1027 entry if it is the tail, because that would lose any
1028 entries we add to the list later on (it would also cause
1029 us to lose track of whether the symbol has been
1031 if (*pundef != info->hash->undefs_tail)
1032 *pundef = (*pundef)->u.undef.next;
1034 pundef = &(*pundef)->u.undef.next;
1038 /* Look for this symbol in the archive symbol map. */
1039 arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE);
1042 /* If we haven't found the exact symbol we're looking for,
1043 let's look for its import thunk */
1044 if (info->pei386_auto_import)
1046 bfd_size_type amt = strlen (h->root.string) + 10;
1047 char *buf = bfd_malloc (amt);
1051 sprintf (buf, "__imp_%s", h->root.string);
1052 arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE);
1057 pundef = &(*pundef)->u.undef.next;
1061 /* Look at all the objects which define this symbol. */
1062 for (l = arh->defs; l != NULL; l = l->next)
1067 /* If the symbol has gotten defined along the way, quit. */
1068 if (h->type != bfd_link_hash_undefined
1069 && h->type != bfd_link_hash_common)
1072 element = bfd_get_elt_at_index (abfd, l->indx);
1073 if (element == NULL)
1076 /* If we've already included this element, or if we've
1077 already checked it on this pass, continue. */
1078 if (element->archive_pass == -1
1079 || element->archive_pass == pass)
1082 /* If we can't figure this element out, just ignore it. */
1083 if (! bfd_check_format (element, bfd_object))
1085 element->archive_pass = -1;
1089 /* CHECKFN will see if this element should be included, and
1090 go ahead and include it if appropriate. */
1091 if (! (*checkfn) (element, info, &needed))
1095 element->archive_pass = pass;
1098 element->archive_pass = -1;
1100 /* Increment the pass count to show that we may need to
1101 recheck object files which were already checked. */
1106 pundef = &(*pundef)->u.undef.next;
1109 archive_hash_table_free (&arsym_hash);
1111 /* Save PASS in case we are called again. */
1112 abfd->archive_pass = pass;
1117 archive_hash_table_free (&arsym_hash);
1121 /* See if we should include an archive element. This version is used
1122 when we do not want to automatically collect constructors based on
1123 the symbol name, presumably because we have some other mechanism
1124 for finding them. */
1127 generic_link_check_archive_element_no_collect (
1129 struct bfd_link_info *info,
1130 bfd_boolean *pneeded)
1132 return generic_link_check_archive_element (abfd, info, pneeded, FALSE);
1135 /* See if we should include an archive element. This version is used
1136 when we want to automatically collect constructors based on the
1137 symbol name, as collect2 does. */
1140 generic_link_check_archive_element_collect (bfd *abfd,
1141 struct bfd_link_info *info,
1142 bfd_boolean *pneeded)
1144 return generic_link_check_archive_element (abfd, info, pneeded, TRUE);
1147 /* See if we should include an archive element. Optionally collect
1151 generic_link_check_archive_element (bfd *abfd,
1152 struct bfd_link_info *info,
1153 bfd_boolean *pneeded,
1154 bfd_boolean collect)
1156 asymbol **pp, **ppend;
1160 if (! generic_link_read_symbols (abfd))
1163 pp = _bfd_generic_link_get_symbols (abfd);
1164 ppend = pp + _bfd_generic_link_get_symcount (abfd);
1165 for (; pp < ppend; pp++)
1168 struct bfd_link_hash_entry *h;
1172 /* We are only interested in globally visible symbols. */
1173 if (! bfd_is_com_section (p->section)
1174 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0)
1177 /* We are only interested if we know something about this
1178 symbol, and it is undefined or common. An undefined weak
1179 symbol (type bfd_link_hash_undefweak) is not considered to be
1180 a reference when pulling files out of an archive. See the
1181 SVR4 ABI, p. 4-27. */
1182 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE,
1185 || (h->type != bfd_link_hash_undefined
1186 && h->type != bfd_link_hash_common))
1189 /* P is a symbol we are looking for. */
1191 if (! bfd_is_com_section (p->section))
1193 bfd_size_type symcount;
1196 /* This object file defines this symbol, so pull it in. */
1197 if (! (*info->callbacks->add_archive_element) (info, abfd,
1198 bfd_asymbol_name (p)))
1200 symcount = _bfd_generic_link_get_symcount (abfd);
1201 symbols = _bfd_generic_link_get_symbols (abfd);
1202 if (! generic_link_add_symbol_list (abfd, info, symcount,
1209 /* P is a common symbol. */
1211 if (h->type == bfd_link_hash_undefined)
1217 symbfd = h->u.undef.abfd;
1220 /* This symbol was created as undefined from outside
1221 BFD. We assume that we should link in the object
1222 file. This is for the -u option in the linker. */
1223 if (! (*info->callbacks->add_archive_element)
1224 (info, abfd, bfd_asymbol_name (p)))
1230 /* Turn the symbol into a common symbol but do not link in
1231 the object file. This is how a.out works. Object
1232 formats that require different semantics must implement
1233 this function differently. This symbol is already on the
1234 undefs list. We add the section to a common section
1235 attached to symbfd to ensure that it is in a BFD which
1236 will be linked in. */
1237 h->type = bfd_link_hash_common;
1239 bfd_hash_allocate (&info->hash->table,
1240 sizeof (struct bfd_link_hash_common_entry));
1241 if (h->u.c.p == NULL)
1244 size = bfd_asymbol_value (p);
1247 power = bfd_log2 (size);
1250 h->u.c.p->alignment_power = power;
1252 if (p->section == bfd_com_section_ptr)
1253 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON");
1255 h->u.c.p->section = bfd_make_section_old_way (symbfd,
1257 h->u.c.p->section->flags = SEC_ALLOC;
1261 /* Adjust the size of the common symbol if necessary. This
1262 is how a.out works. Object formats that require
1263 different semantics must implement this function
1265 if (bfd_asymbol_value (p) > h->u.c.size)
1266 h->u.c.size = bfd_asymbol_value (p);
1270 /* This archive element is not needed. */
1274 /* Add the symbols from an object file to the global hash table. ABFD
1275 is the object file. INFO is the linker information. SYMBOL_COUNT
1276 is the number of symbols. SYMBOLS is the list of symbols. COLLECT
1277 is TRUE if constructors should be automatically collected by name
1278 as is done by collect2. */
1281 generic_link_add_symbol_list (bfd *abfd,
1282 struct bfd_link_info *info,
1283 bfd_size_type symbol_count,
1285 bfd_boolean collect)
1287 asymbol **pp, **ppend;
1290 ppend = symbols + symbol_count;
1291 for (; pp < ppend; pp++)
1297 if ((p->flags & (BSF_INDIRECT
1302 || bfd_is_und_section (bfd_get_section (p))
1303 || bfd_is_com_section (bfd_get_section (p))
1304 || bfd_is_ind_section (bfd_get_section (p)))
1308 struct generic_link_hash_entry *h;
1309 struct bfd_link_hash_entry *bh;
1311 name = bfd_asymbol_name (p);
1312 if (((p->flags & BSF_INDIRECT) != 0
1313 || bfd_is_ind_section (p->section))
1317 string = bfd_asymbol_name (*pp);
1319 else if ((p->flags & BSF_WARNING) != 0
1322 /* The name of P is actually the warning string, and the
1323 next symbol is the one to warn about. */
1326 name = bfd_asymbol_name (*pp);
1332 if (! (_bfd_generic_link_add_one_symbol
1333 (info, abfd, name, p->flags, bfd_get_section (p),
1334 p->value, string, FALSE, collect, &bh)))
1336 h = (struct generic_link_hash_entry *) bh;
1338 /* If this is a constructor symbol, and the linker didn't do
1339 anything with it, then we want to just pass the symbol
1340 through to the output file. This will happen when
1342 if ((p->flags & BSF_CONSTRUCTOR) != 0
1343 && (h == NULL || h->root.type == bfd_link_hash_new))
1349 /* Save the BFD symbol so that we don't lose any backend
1350 specific information that may be attached to it. We only
1351 want this one if it gives more information than the
1352 existing one; we don't want to replace a defined symbol
1353 with an undefined one. This routine may be called with a
1354 hash table other than the generic hash table, so we only
1355 do this if we are certain that the hash table is a
1357 if (info->hash->creator == abfd->xvec)
1360 || (! bfd_is_und_section (bfd_get_section (p))
1361 && (! bfd_is_com_section (bfd_get_section (p))
1362 || bfd_is_und_section (bfd_get_section (h->sym)))))
1365 /* BSF_OLD_COMMON is a hack to support COFF reloc
1366 reading, and it should go away when the COFF
1367 linker is switched to the new version. */
1368 if (bfd_is_com_section (bfd_get_section (p)))
1369 p->flags |= BSF_OLD_COMMON;
1373 /* Store a back pointer from the symbol to the hash
1374 table entry for the benefit of relaxation code until
1375 it gets rewritten to not use asymbol structures.
1376 Setting this is also used to check whether these
1377 symbols were set up by the generic linker. */
1385 /* We use a state table to deal with adding symbols from an object
1386 file. The first index into the state table describes the symbol
1387 from the object file. The second index into the state table is the
1388 type of the symbol in the hash table. */
1390 /* The symbol from the object file is turned into one of these row
1395 UNDEF_ROW, /* Undefined. */
1396 UNDEFW_ROW, /* Weak undefined. */
1397 DEF_ROW, /* Defined. */
1398 DEFW_ROW, /* Weak defined. */
1399 COMMON_ROW, /* Common. */
1400 INDR_ROW, /* Indirect. */
1401 WARN_ROW, /* Warning. */
1402 SET_ROW /* Member of set. */
1405 /* apparently needed for Hitachi 3050R(HI-UX/WE2)? */
1408 /* The actions to take in the state table. */
1413 UND, /* Mark symbol undefined. */
1414 WEAK, /* Mark symbol weak undefined. */
1415 DEF, /* Mark symbol defined. */
1416 DEFW, /* Mark symbol weak defined. */
1417 COM, /* Mark symbol common. */
1418 REF, /* Mark defined symbol referenced. */
1419 CREF, /* Possibly warn about common reference to defined symbol. */
1420 CDEF, /* Define existing common symbol. */
1421 NOACT, /* No action. */
1422 BIG, /* Mark symbol common using largest size. */
1423 MDEF, /* Multiple definition error. */
1424 MIND, /* Multiple indirect symbols. */
1425 IND, /* Make indirect symbol. */
1426 CIND, /* Make indirect symbol from existing common symbol. */
1427 SET, /* Add value to set. */
1428 MWARN, /* Make warning symbol. */
1429 WARN, /* Issue warning. */
1430 CWARN, /* Warn if referenced, else MWARN. */
1431 CYCLE, /* Repeat with symbol pointed to. */
1432 REFC, /* Mark indirect symbol referenced and then CYCLE. */
1433 WARNC /* Issue warning and then CYCLE. */
1436 /* The state table itself. The first index is a link_row and the
1437 second index is a bfd_link_hash_type. */
1439 static const enum link_action link_action[8][8] =
1441 /* current\prev new undef undefw def defw com indr warn */
1442 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC },
1443 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC },
1444 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE },
1445 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE },
1446 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC },
1447 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE },
1448 /* WARN_ROW */ {MWARN, WARN, WARN, CWARN, CWARN, WARN, CWARN, NOACT },
1449 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE }
1452 /* Most of the entries in the LINK_ACTION table are straightforward,
1453 but a few are somewhat subtle.
1455 A reference to an indirect symbol (UNDEF_ROW/indr or
1456 UNDEFW_ROW/indr) is counted as a reference both to the indirect
1457 symbol and to the symbol the indirect symbol points to.
1459 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn)
1460 causes the warning to be issued.
1462 A common definition of an indirect symbol (COMMON_ROW/indr) is
1463 treated as a multiple definition error. Likewise for an indirect
1464 definition of a common symbol (INDR_ROW/com).
1466 An indirect definition of a warning (INDR_ROW/warn) does not cause
1467 the warning to be issued.
1469 If a warning is created for an indirect symbol (WARN_ROW/indr) no
1470 warning is created for the symbol the indirect symbol points to.
1472 Adding an entry to a set does not count as a reference to a set,
1473 and no warning is issued (SET_ROW/warn). */
1475 /* Return the BFD in which a hash entry has been defined, if known. */
1478 hash_entry_bfd (struct bfd_link_hash_entry *h)
1480 while (h->type == bfd_link_hash_warning)
1486 case bfd_link_hash_undefined:
1487 case bfd_link_hash_undefweak:
1488 return h->u.undef.abfd;
1489 case bfd_link_hash_defined:
1490 case bfd_link_hash_defweak:
1491 return h->u.def.section->owner;
1492 case bfd_link_hash_common:
1493 return h->u.c.p->section->owner;
1498 /* Add a symbol to the global hash table.
1499 ABFD is the BFD the symbol comes from.
1500 NAME is the name of the symbol.
1501 FLAGS is the BSF_* bits associated with the symbol.
1502 SECTION is the section in which the symbol is defined; this may be
1503 bfd_und_section_ptr or bfd_com_section_ptr.
1504 VALUE is the value of the symbol, relative to the section.
1505 STRING is used for either an indirect symbol, in which case it is
1506 the name of the symbol to indirect to, or a warning symbol, in
1507 which case it is the warning string.
1508 COPY is TRUE if NAME or STRING must be copied into locally
1509 allocated memory if they need to be saved.
1510 COLLECT is TRUE if we should automatically collect gcc constructor
1511 or destructor names as collect2 does.
1512 HASHP, if not NULL, is a place to store the created hash table
1513 entry; if *HASHP is not NULL, the caller has already looked up
1514 the hash table entry, and stored it in *HASHP. */
1517 _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
1525 bfd_boolean collect,
1526 struct bfd_link_hash_entry **hashp)
1529 struct bfd_link_hash_entry *h;
1532 if (bfd_is_ind_section (section)
1533 || (flags & BSF_INDIRECT) != 0)
1535 else if ((flags & BSF_WARNING) != 0)
1537 else if ((flags & BSF_CONSTRUCTOR) != 0)
1539 else if (bfd_is_und_section (section))
1541 if ((flags & BSF_WEAK) != 0)
1546 else if ((flags & BSF_WEAK) != 0)
1548 else if (bfd_is_com_section (section))
1553 if (hashp != NULL && *hashp != NULL)
1557 if (row == UNDEF_ROW || row == UNDEFW_ROW)
1558 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE);
1560 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE);
1569 if (info->notice_all
1570 || (info->notice_hash != NULL
1571 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL))
1573 if (! (*info->callbacks->notice) (info, h->root.string, abfd, section,
1583 enum link_action action;
1586 action = link_action[(int) row][(int) h->type];
1597 /* Make a new undefined symbol. */
1598 h->type = bfd_link_hash_undefined;
1599 h->u.undef.abfd = abfd;
1600 bfd_link_add_undef (info->hash, h);
1604 /* Make a new weak undefined symbol. */
1605 h->type = bfd_link_hash_undefweak;
1606 h->u.undef.abfd = abfd;
1607 h->u.undef.weak = abfd;
1611 /* We have found a definition for a symbol which was
1612 previously common. */
1613 BFD_ASSERT (h->type == bfd_link_hash_common);
1614 if (! ((*info->callbacks->multiple_common)
1615 (info, h->root.string,
1616 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size,
1617 abfd, bfd_link_hash_defined, 0)))
1623 enum bfd_link_hash_type oldtype;
1625 /* Define a symbol. */
1628 h->type = bfd_link_hash_defweak;
1630 h->type = bfd_link_hash_defined;
1631 h->u.def.section = section;
1632 h->u.def.value = value;
1634 /* If we have been asked to, we act like collect2 and
1635 identify all functions that might be global
1636 constructors and destructors and pass them up in a
1637 callback. We only do this for certain object file
1638 types, since many object file types can handle this
1640 if (collect && name[0] == '_')
1644 /* A constructor or destructor name starts like this:
1645 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and
1646 the second are the same character (we accept any
1647 character there, in case a new object file format
1648 comes along with even worse naming restrictions). */
1650 #define CONS_PREFIX "GLOBAL_"
1651 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1)
1657 && strncmp (s, CONS_PREFIX, CONS_PREFIX_LEN - 1) == 0)
1661 c = s[CONS_PREFIX_LEN + 1];
1662 if ((c == 'I' || c == 'D')
1663 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2])
1665 /* If this is a definition of a symbol which
1666 was previously weakly defined, we are in
1667 trouble. We have already added a
1668 constructor entry for the weak defined
1669 symbol, and now we are trying to add one
1670 for the new symbol. Fortunately, this case
1671 should never arise in practice. */
1672 if (oldtype == bfd_link_hash_defweak)
1675 if (! ((*info->callbacks->constructor)
1677 h->root.string, abfd, section, value)))
1687 /* We have found a common definition for a symbol. */
1688 if (h->type == bfd_link_hash_new)
1689 bfd_link_add_undef (info->hash, h);
1690 h->type = bfd_link_hash_common;
1692 bfd_hash_allocate (&info->hash->table,
1693 sizeof (struct bfd_link_hash_common_entry));
1694 if (h->u.c.p == NULL)
1697 h->u.c.size = value;
1699 /* Select a default alignment based on the size. This may
1700 be overridden by the caller. */
1704 power = bfd_log2 (value);
1707 h->u.c.p->alignment_power = power;
1710 /* The section of a common symbol is only used if the common
1711 symbol is actually allocated. It basically provides a
1712 hook for the linker script to decide which output section
1713 the common symbols should be put in. In most cases, the
1714 section of a common symbol will be bfd_com_section_ptr,
1715 the code here will choose a common symbol section named
1716 "COMMON", and the linker script will contain *(COMMON) in
1717 the appropriate place. A few targets use separate common
1718 sections for small symbols, and they require special
1720 if (section == bfd_com_section_ptr)
1722 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON");
1723 h->u.c.p->section->flags = SEC_ALLOC;
1725 else if (section->owner != abfd)
1727 h->u.c.p->section = bfd_make_section_old_way (abfd,
1729 h->u.c.p->section->flags = SEC_ALLOC;
1732 h->u.c.p->section = section;
1736 /* A reference to a defined symbol. */
1737 if (h->u.undef.next == NULL && info->hash->undefs_tail != h)
1738 h->u.undef.next = h;
1742 /* We have found a common definition for a symbol which
1743 already had a common definition. Use the maximum of the
1744 two sizes, and use the section required by the larger symbol. */
1745 BFD_ASSERT (h->type == bfd_link_hash_common);
1746 if (! ((*info->callbacks->multiple_common)
1747 (info, h->root.string,
1748 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size,
1749 abfd, bfd_link_hash_common, value)))
1751 if (value > h->u.c.size)
1755 h->u.c.size = value;
1757 /* Select a default alignment based on the size. This may
1758 be overridden by the caller. */
1759 power = bfd_log2 (value);
1762 h->u.c.p->alignment_power = power;
1764 /* Some systems have special treatment for small commons,
1765 hence we want to select the section used by the larger
1766 symbol. This makes sure the symbol does not go in a
1767 small common section if it is now too large. */
1768 if (section == bfd_com_section_ptr)
1771 = bfd_make_section_old_way (abfd, "COMMON");
1772 h->u.c.p->section->flags = SEC_ALLOC;
1774 else if (section->owner != abfd)
1777 = bfd_make_section_old_way (abfd, section->name);
1778 h->u.c.p->section->flags = SEC_ALLOC;
1781 h->u.c.p->section = section;
1789 /* We have found a common definition for a symbol which
1790 was already defined. FIXME: It would nice if we could
1791 report the BFD which defined an indirect symbol, but we
1792 don't have anywhere to store the information. */
1793 if (h->type == bfd_link_hash_defined
1794 || h->type == bfd_link_hash_defweak)
1795 obfd = h->u.def.section->owner;
1798 if (! ((*info->callbacks->multiple_common)
1799 (info, h->root.string, obfd, h->type, 0,
1800 abfd, bfd_link_hash_common, value)))
1806 /* Multiple indirect symbols. This is OK if they both point
1807 to the same symbol. */
1808 if (strcmp (h->u.i.link->root.string, string) == 0)
1812 /* Handle a multiple definition. */
1813 if (!info->allow_multiple_definition)
1815 asection *msec = NULL;
1820 case bfd_link_hash_defined:
1821 msec = h->u.def.section;
1822 mval = h->u.def.value;
1824 case bfd_link_hash_indirect:
1825 msec = bfd_ind_section_ptr;
1832 /* Ignore a redefinition of an absolute symbol to the
1833 same value; it's harmless. */
1834 if (h->type == bfd_link_hash_defined
1835 && bfd_is_abs_section (msec)
1836 && bfd_is_abs_section (section)
1840 if (! ((*info->callbacks->multiple_definition)
1841 (info, h->root.string, msec->owner, msec, mval,
1842 abfd, section, value)))
1848 /* Create an indirect symbol from an existing common symbol. */
1849 BFD_ASSERT (h->type == bfd_link_hash_common);
1850 if (! ((*info->callbacks->multiple_common)
1851 (info, h->root.string,
1852 h->u.c.p->section->owner, bfd_link_hash_common, h->u.c.size,
1853 abfd, bfd_link_hash_indirect, 0)))
1857 /* Create an indirect symbol. */
1859 struct bfd_link_hash_entry *inh;
1861 /* STRING is the name of the symbol we want to indirect
1863 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE,
1867 if (inh->type == bfd_link_hash_indirect
1868 && inh->u.i.link == h)
1870 (*_bfd_error_handler)
1871 (_("%B: indirect symbol `%s' to `%s' is a loop"),
1872 abfd, name, string);
1873 bfd_set_error (bfd_error_invalid_operation);
1876 if (inh->type == bfd_link_hash_new)
1878 inh->type = bfd_link_hash_undefined;
1879 inh->u.undef.abfd = abfd;
1880 bfd_link_add_undef (info->hash, inh);
1883 /* If the indirect symbol has been referenced, we need to
1884 push the reference down to the symbol we are
1886 if (h->type != bfd_link_hash_new)
1892 h->type = bfd_link_hash_indirect;
1898 /* Add an entry to a set. */
1899 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR,
1900 abfd, section, value))
1905 /* Issue a warning and cycle. */
1906 if (h->u.i.warning != NULL)
1908 if (! (*info->callbacks->warning) (info, h->u.i.warning,
1909 h->root.string, abfd,
1912 /* Only issue a warning once. */
1913 h->u.i.warning = NULL;
1917 /* Try again with the referenced symbol. */
1923 /* A reference to an indirect symbol. */
1924 if (h->u.undef.next == NULL && info->hash->undefs_tail != h)
1925 h->u.undef.next = h;
1931 /* Issue a warning. */
1932 if (! (*info->callbacks->warning) (info, string, h->root.string,
1933 hash_entry_bfd (h), NULL, 0))
1938 /* Warn if this symbol has been referenced already,
1939 otherwise add a warning. A symbol has been referenced if
1940 the u.undef.next field is not NULL, or it is the tail of the
1941 undefined symbol list. The REF case above helps to
1943 if (h->u.undef.next != NULL || info->hash->undefs_tail == h)
1945 if (! (*info->callbacks->warning) (info, string, h->root.string,
1946 hash_entry_bfd (h), NULL, 0))
1952 /* Make a warning symbol. */
1954 struct bfd_link_hash_entry *sub;
1956 /* STRING is the warning to give. */
1957 sub = ((struct bfd_link_hash_entry *)
1958 ((*info->hash->table.newfunc)
1959 (NULL, &info->hash->table, h->root.string)));
1963 sub->type = bfd_link_hash_warning;
1966 sub->u.i.warning = string;
1970 size_t len = strlen (string) + 1;
1972 w = bfd_hash_allocate (&info->hash->table, len);
1975 memcpy (w, string, len);
1976 sub->u.i.warning = w;
1979 bfd_hash_replace (&info->hash->table,
1980 (struct bfd_hash_entry *) h,
1981 (struct bfd_hash_entry *) sub);
1993 /* Generic final link routine. */
1996 _bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info)
2000 struct bfd_link_order *p;
2002 struct generic_write_global_symbol_info wginfo;
2004 bfd_get_outsymbols (abfd) = NULL;
2005 bfd_get_symcount (abfd) = 0;
2008 /* Mark all sections which will be included in the output file. */
2009 for (o = abfd->sections; o != NULL; o = o->next)
2010 for (p = o->link_order_head; p != NULL; p = p->next)
2011 if (p->type == bfd_indirect_link_order)
2012 p->u.indirect.section->linker_mark = TRUE;
2014 /* Build the output symbol table. */
2015 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
2016 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc))
2019 /* Accumulate the global symbols. */
2021 wginfo.output_bfd = abfd;
2022 wginfo.psymalloc = &outsymalloc;
2023 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info),
2024 _bfd_generic_link_write_global_symbol,
2027 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We
2028 shouldn't really need one, since we have SYMCOUNT, but some old
2029 code still expects one. */
2030 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL))
2033 if (info->relocatable)
2035 /* Allocate space for the output relocs for each section. */
2036 for (o = abfd->sections; o != NULL; o = o->next)
2039 for (p = o->link_order_head; p != NULL; p = p->next)
2041 if (p->type == bfd_section_reloc_link_order
2042 || p->type == bfd_symbol_reloc_link_order)
2044 else if (p->type == bfd_indirect_link_order)
2046 asection *input_section;
2053 input_section = p->u.indirect.section;
2054 input_bfd = input_section->owner;
2055 relsize = bfd_get_reloc_upper_bound (input_bfd,
2059 relocs = bfd_malloc (relsize);
2060 if (!relocs && relsize != 0)
2062 symbols = _bfd_generic_link_get_symbols (input_bfd);
2063 reloc_count = bfd_canonicalize_reloc (input_bfd,
2068 if (reloc_count < 0)
2070 BFD_ASSERT ((unsigned long) reloc_count
2071 == input_section->reloc_count);
2072 o->reloc_count += reloc_count;
2075 if (o->reloc_count > 0)
2079 amt = o->reloc_count;
2080 amt *= sizeof (arelent *);
2081 o->orelocation = bfd_alloc (abfd, amt);
2082 if (!o->orelocation)
2084 o->flags |= SEC_RELOC;
2085 /* Reset the count so that it can be used as an index
2086 when putting in the output relocs. */
2092 /* Handle all the link order information for the sections. */
2093 for (o = abfd->sections; o != NULL; o = o->next)
2095 for (p = o->link_order_head; p != NULL; p = p->next)
2099 case bfd_section_reloc_link_order:
2100 case bfd_symbol_reloc_link_order:
2101 if (! _bfd_generic_reloc_link_order (abfd, info, o, p))
2104 case bfd_indirect_link_order:
2105 if (! default_indirect_link_order (abfd, info, o, p, TRUE))
2109 if (! _bfd_default_link_order (abfd, info, o, p))
2119 /* Add an output symbol to the output BFD. */
2122 generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym)
2124 if (bfd_get_symcount (output_bfd) >= *psymalloc)
2129 if (*psymalloc == 0)
2134 amt *= sizeof (asymbol *);
2135 newsyms = bfd_realloc (bfd_get_outsymbols (output_bfd), amt);
2136 if (newsyms == NULL)
2138 bfd_get_outsymbols (output_bfd) = newsyms;
2141 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym;
2143 ++ bfd_get_symcount (output_bfd);
2148 /* Handle the symbols for an input BFD. */
2151 _bfd_generic_link_output_symbols (bfd *output_bfd,
2153 struct bfd_link_info *info,
2159 if (! generic_link_read_symbols (input_bfd))
2162 /* Create a filename symbol if we are supposed to. */
2163 if (info->create_object_symbols_section != NULL)
2167 for (sec = input_bfd->sections; sec != NULL; sec = sec->next)
2169 if (sec->output_section == info->create_object_symbols_section)
2173 newsym = bfd_make_empty_symbol (input_bfd);
2176 newsym->name = input_bfd->filename;
2178 newsym->flags = BSF_LOCAL | BSF_FILE;
2179 newsym->section = sec;
2181 if (! generic_add_output_symbol (output_bfd, psymalloc,
2190 /* Adjust the values of the globally visible symbols, and write out
2192 sym_ptr = _bfd_generic_link_get_symbols (input_bfd);
2193 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd);
2194 for (; sym_ptr < sym_end; sym_ptr++)
2197 struct generic_link_hash_entry *h;
2202 if ((sym->flags & (BSF_INDIRECT
2207 || bfd_is_und_section (bfd_get_section (sym))
2208 || bfd_is_com_section (bfd_get_section (sym))
2209 || bfd_is_ind_section (bfd_get_section (sym)))
2211 if (sym->udata.p != NULL)
2213 else if ((sym->flags & BSF_CONSTRUCTOR) != 0)
2215 /* This case normally means that the main linker code
2216 deliberately ignored this constructor symbol. We
2217 should just pass it through. This will screw up if
2218 the constructor symbol is from a different,
2219 non-generic, object file format, but the case will
2220 only arise when linking with -r, which will probably
2221 fail anyhow, since there will be no way to represent
2222 the relocs in the output format being used. */
2225 else if (bfd_is_und_section (bfd_get_section (sym)))
2226 h = ((struct generic_link_hash_entry *)
2227 bfd_wrapped_link_hash_lookup (output_bfd, info,
2228 bfd_asymbol_name (sym),
2229 FALSE, FALSE, TRUE));
2231 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info),
2232 bfd_asymbol_name (sym),
2233 FALSE, FALSE, TRUE);
2237 /* Force all references to this symbol to point to
2238 the same area in memory. It is possible that
2239 this routine will be called with a hash table
2240 other than a generic hash table, so we double
2242 if (info->hash->creator == input_bfd->xvec)
2245 *sym_ptr = sym = h->sym;
2248 switch (h->root.type)
2251 case bfd_link_hash_new:
2253 case bfd_link_hash_undefined:
2255 case bfd_link_hash_undefweak:
2256 sym->flags |= BSF_WEAK;
2258 case bfd_link_hash_indirect:
2259 h = (struct generic_link_hash_entry *) h->root.u.i.link;
2261 case bfd_link_hash_defined:
2262 sym->flags |= BSF_GLOBAL;
2263 sym->flags &=~ BSF_CONSTRUCTOR;
2264 sym->value = h->root.u.def.value;
2265 sym->section = h->root.u.def.section;
2267 case bfd_link_hash_defweak:
2268 sym->flags |= BSF_WEAK;
2269 sym->flags &=~ BSF_CONSTRUCTOR;
2270 sym->value = h->root.u.def.value;
2271 sym->section = h->root.u.def.section;
2273 case bfd_link_hash_common:
2274 sym->value = h->root.u.c.size;
2275 sym->flags |= BSF_GLOBAL;
2276 if (! bfd_is_com_section (sym->section))
2278 BFD_ASSERT (bfd_is_und_section (sym->section));
2279 sym->section = bfd_com_section_ptr;
2281 /* We do not set the section of the symbol to
2282 h->root.u.c.p->section. That value was saved so
2283 that we would know where to allocate the symbol
2284 if it was defined. In this case the type is
2285 still bfd_link_hash_common, so we did not define
2286 it, so we do not want to use that section. */
2292 /* This switch is straight from the old code in
2293 write_file_locals in ldsym.c. */
2294 if (info->strip == strip_all
2295 || (info->strip == strip_some
2296 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym),
2297 FALSE, FALSE) == NULL))
2299 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0)
2301 /* If this symbol is marked as occurring now, rather
2302 than at the end, output it now. This is used for
2303 COFF C_EXT FCN symbols. FIXME: There must be a
2305 if (bfd_asymbol_bfd (sym) == input_bfd
2306 && (sym->flags & BSF_NOT_AT_END) != 0)
2311 else if (bfd_is_ind_section (sym->section))
2313 else if ((sym->flags & BSF_DEBUGGING) != 0)
2315 if (info->strip == strip_none)
2320 else if (bfd_is_und_section (sym->section)
2321 || bfd_is_com_section (sym->section))
2323 else if ((sym->flags & BSF_LOCAL) != 0)
2325 if ((sym->flags & BSF_WARNING) != 0)
2329 switch (info->discard)
2335 case discard_sec_merge:
2337 if (info->relocatable
2338 || ! (sym->section->flags & SEC_MERGE))
2342 if (bfd_is_local_label (input_bfd, sym))
2353 else if ((sym->flags & BSF_CONSTRUCTOR))
2355 if (info->strip != strip_all)
2363 /* If this symbol is in a section which is not being included
2364 in the output file, then we don't want to output the symbol.
2366 Gross. .bss and similar sections won't have the linker_mark
2368 if ((sym->section->flags & SEC_HAS_CONTENTS) != 0
2369 && ! sym->section->linker_mark)
2374 if (! generic_add_output_symbol (output_bfd, psymalloc, sym))
2384 /* Set the section and value of a generic BFD symbol based on a linker
2385 hash table entry. */
2388 set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h)
2395 case bfd_link_hash_new:
2396 /* This can happen when a constructor symbol is seen but we are
2397 not building constructors. */
2398 if (sym->section != NULL)
2400 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0);
2404 sym->flags |= BSF_CONSTRUCTOR;
2405 sym->section = bfd_abs_section_ptr;
2409 case bfd_link_hash_undefined:
2410 sym->section = bfd_und_section_ptr;
2413 case bfd_link_hash_undefweak:
2414 sym->section = bfd_und_section_ptr;
2416 sym->flags |= BSF_WEAK;
2418 case bfd_link_hash_defined:
2419 sym->section = h->u.def.section;
2420 sym->value = h->u.def.value;
2422 case bfd_link_hash_defweak:
2423 sym->flags |= BSF_WEAK;
2424 sym->section = h->u.def.section;
2425 sym->value = h->u.def.value;
2427 case bfd_link_hash_common:
2428 sym->value = h->u.c.size;
2429 if (sym->section == NULL)
2430 sym->section = bfd_com_section_ptr;
2431 else if (! bfd_is_com_section (sym->section))
2433 BFD_ASSERT (bfd_is_und_section (sym->section));
2434 sym->section = bfd_com_section_ptr;
2436 /* Do not set the section; see _bfd_generic_link_output_symbols. */
2438 case bfd_link_hash_indirect:
2439 case bfd_link_hash_warning:
2440 /* FIXME: What should we do here? */
2445 /* Write out a global symbol, if it hasn't already been written out.
2446 This is called for each symbol in the hash table. */
2449 _bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h,
2452 struct generic_write_global_symbol_info *wginfo = data;
2455 if (h->root.type == bfd_link_hash_warning)
2456 h = (struct generic_link_hash_entry *) h->root.u.i.link;
2463 if (wginfo->info->strip == strip_all
2464 || (wginfo->info->strip == strip_some
2465 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string,
2466 FALSE, FALSE) == NULL))
2473 sym = bfd_make_empty_symbol (wginfo->output_bfd);
2476 sym->name = h->root.root.string;
2480 set_symbol_from_hash (sym, &h->root);
2482 sym->flags |= BSF_GLOBAL;
2484 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc,
2487 /* FIXME: No way to return failure. */
2494 /* Create a relocation. */
2497 _bfd_generic_reloc_link_order (bfd *abfd,
2498 struct bfd_link_info *info,
2500 struct bfd_link_order *link_order)
2504 if (! info->relocatable)
2506 if (sec->orelocation == NULL)
2509 r = bfd_alloc (abfd, sizeof (arelent));
2513 r->address = link_order->offset;
2514 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc);
2517 bfd_set_error (bfd_error_bad_value);
2521 /* Get the symbol to use for the relocation. */
2522 if (link_order->type == bfd_section_reloc_link_order)
2523 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr;
2526 struct generic_link_hash_entry *h;
2528 h = ((struct generic_link_hash_entry *)
2529 bfd_wrapped_link_hash_lookup (abfd, info,
2530 link_order->u.reloc.p->u.name,
2531 FALSE, FALSE, TRUE));
2535 if (! ((*info->callbacks->unattached_reloc)
2536 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0)))
2538 bfd_set_error (bfd_error_bad_value);
2541 r->sym_ptr_ptr = &h->sym;
2544 /* If this is an inplace reloc, write the addend to the object file.
2545 Otherwise, store it in the reloc addend. */
2546 if (! r->howto->partial_inplace)
2547 r->addend = link_order->u.reloc.p->addend;
2551 bfd_reloc_status_type rstat;
2556 size = bfd_get_reloc_size (r->howto);
2557 buf = bfd_zmalloc (size);
2560 rstat = _bfd_relocate_contents (r->howto, abfd,
2561 (bfd_vma) link_order->u.reloc.p->addend,
2568 case bfd_reloc_outofrange:
2570 case bfd_reloc_overflow:
2571 if (! ((*info->callbacks->reloc_overflow)
2573 (link_order->type == bfd_section_reloc_link_order
2574 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section)
2575 : link_order->u.reloc.p->u.name),
2576 r->howto->name, link_order->u.reloc.p->addend,
2584 loc = link_order->offset * bfd_octets_per_byte (abfd);
2585 ok = bfd_set_section_contents (abfd, sec, buf, loc, size);
2593 sec->orelocation[sec->reloc_count] = r;
2599 /* Allocate a new link_order for a section. */
2601 struct bfd_link_order *
2602 bfd_new_link_order (bfd *abfd, asection *section)
2604 bfd_size_type amt = sizeof (struct bfd_link_order);
2605 struct bfd_link_order *new;
2607 new = bfd_zalloc (abfd, amt);
2611 new->type = bfd_undefined_link_order;
2613 if (section->link_order_tail != NULL)
2614 section->link_order_tail->next = new;
2616 section->link_order_head = new;
2617 section->link_order_tail = new;
2622 /* Default link order processing routine. Note that we can not handle
2623 the reloc_link_order types here, since they depend upon the details
2624 of how the particular backends generates relocs. */
2627 _bfd_default_link_order (bfd *abfd,
2628 struct bfd_link_info *info,
2630 struct bfd_link_order *link_order)
2632 switch (link_order->type)
2634 case bfd_undefined_link_order:
2635 case bfd_section_reloc_link_order:
2636 case bfd_symbol_reloc_link_order:
2639 case bfd_indirect_link_order:
2640 return default_indirect_link_order (abfd, info, sec, link_order,
2642 case bfd_data_link_order:
2643 return default_data_link_order (abfd, info, sec, link_order);
2647 /* Default routine to handle a bfd_data_link_order. */
2650 default_data_link_order (bfd *abfd,
2651 struct bfd_link_info *info ATTRIBUTE_UNUSED,
2653 struct bfd_link_order *link_order)
2661 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0);
2663 size = link_order->size;
2667 fill = link_order->u.data.contents;
2668 fill_size = link_order->u.data.size;
2669 if (fill_size != 0 && fill_size < size)
2672 fill = bfd_malloc (size);
2677 memset (p, (int) link_order->u.data.contents[0], (size_t) size);
2682 memcpy (p, link_order->u.data.contents, fill_size);
2686 while (size >= fill_size);
2688 memcpy (p, link_order->u.data.contents, (size_t) size);
2689 size = link_order->size;
2693 loc = link_order->offset * bfd_octets_per_byte (abfd);
2694 result = bfd_set_section_contents (abfd, sec, fill, loc, size);
2696 if (fill != link_order->u.data.contents)
2701 /* Default routine to handle a bfd_indirect_link_order. */
2704 default_indirect_link_order (bfd *output_bfd,
2705 struct bfd_link_info *info,
2706 asection *output_section,
2707 struct bfd_link_order *link_order,
2708 bfd_boolean generic_linker)
2710 asection *input_section;
2712 bfd_byte *contents = NULL;
2713 bfd_byte *new_contents;
2714 bfd_size_type sec_size;
2717 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0);
2719 if (link_order->size == 0)
2722 input_section = link_order->u.indirect.section;
2723 input_bfd = input_section->owner;
2725 BFD_ASSERT (input_section->output_section == output_section);
2726 BFD_ASSERT (input_section->output_offset == link_order->offset);
2727 BFD_ASSERT (input_section->size == link_order->size);
2729 if (info->relocatable
2730 && input_section->reloc_count > 0
2731 && output_section->orelocation == NULL)
2733 /* Space has not been allocated for the output relocations.
2734 This can happen when we are called by a specific backend
2735 because somebody is attempting to link together different
2736 types of object files. Handling this case correctly is
2737 difficult, and sometimes impossible. */
2738 (*_bfd_error_handler)
2739 (_("Attempt to do relocatable link with %s input and %s output"),
2740 bfd_get_target (input_bfd), bfd_get_target (output_bfd));
2741 bfd_set_error (bfd_error_wrong_format);
2745 if (! generic_linker)
2750 /* Get the canonical symbols. The generic linker will always
2751 have retrieved them by this point, but we are being called by
2752 a specific linker, presumably because we are linking
2753 different types of object files together. */
2754 if (! generic_link_read_symbols (input_bfd))
2757 /* Since we have been called by a specific linker, rather than
2758 the generic linker, the values of the symbols will not be
2759 right. They will be the values as seen in the input file,
2760 not the values of the final link. We need to fix them up
2761 before we can relocate the section. */
2762 sympp = _bfd_generic_link_get_symbols (input_bfd);
2763 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd);
2764 for (; sympp < symppend; sympp++)
2767 struct bfd_link_hash_entry *h;
2771 if ((sym->flags & (BSF_INDIRECT
2776 || bfd_is_und_section (bfd_get_section (sym))
2777 || bfd_is_com_section (bfd_get_section (sym))
2778 || bfd_is_ind_section (bfd_get_section (sym)))
2780 /* sym->udata may have been set by
2781 generic_link_add_symbol_list. */
2782 if (sym->udata.p != NULL)
2784 else if (bfd_is_und_section (bfd_get_section (sym)))
2785 h = bfd_wrapped_link_hash_lookup (output_bfd, info,
2786 bfd_asymbol_name (sym),
2787 FALSE, FALSE, TRUE);
2789 h = bfd_link_hash_lookup (info->hash,
2790 bfd_asymbol_name (sym),
2791 FALSE, FALSE, TRUE);
2793 set_symbol_from_hash (sym, h);
2798 /* Get and relocate the section contents. */
2799 sec_size = (input_section->rawsize > input_section->size
2800 ? input_section->rawsize
2801 : input_section->size);
2802 contents = bfd_malloc (sec_size);
2803 if (contents == NULL && sec_size != 0)
2805 new_contents = (bfd_get_relocated_section_contents
2806 (output_bfd, info, link_order, contents, info->relocatable,
2807 _bfd_generic_link_get_symbols (input_bfd)));
2811 /* Output the section contents. */
2812 loc = link_order->offset * bfd_octets_per_byte (output_bfd);
2813 if (! bfd_set_section_contents (output_bfd, output_section,
2814 new_contents, loc, link_order->size))
2817 if (contents != NULL)
2822 if (contents != NULL)
2827 /* A little routine to count the number of relocs in a link_order
2831 _bfd_count_link_order_relocs (struct bfd_link_order *link_order)
2833 register unsigned int c;
2834 register struct bfd_link_order *l;
2837 for (l = link_order; l != NULL; l = l->next)
2839 if (l->type == bfd_section_reloc_link_order
2840 || l->type == bfd_symbol_reloc_link_order)
2849 bfd_link_split_section
2852 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec);
2855 Return nonzero if @var{sec} should be split during a
2856 reloceatable or final link.
2858 .#define bfd_link_split_section(abfd, sec) \
2859 . BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec))
2865 _bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED,
2866 asection *sec ATTRIBUTE_UNUSED)
2873 bfd_section_already_linked
2876 void bfd_section_already_linked (bfd *abfd, asection *sec);
2879 Check if @var{sec} has been already linked during a reloceatable
2882 .#define bfd_section_already_linked(abfd, sec) \
2883 . BFD_SEND (abfd, _section_already_linked, (abfd, sec))
2888 /* Sections marked with the SEC_LINK_ONCE flag should only be linked
2889 once into the output. This routine checks each section, and
2890 arrange to discard it if a section of the same name has already
2891 been linked. This code assumes that all relevant sections have the
2892 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the
2893 section name. bfd_section_already_linked is called via
2894 bfd_map_over_sections. */
2896 /* The hash table. */
2898 static struct bfd_hash_table _bfd_section_already_linked_table;
2900 /* Support routines for the hash table used by section_already_linked,
2901 initialize the table, traverse, lookup, fill in an entry and remove
2905 bfd_section_already_linked_table_traverse
2906 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *,
2907 void *), void *info)
2909 bfd_hash_traverse (&_bfd_section_already_linked_table,
2910 (bfd_boolean (*) (struct bfd_hash_entry *,
2915 struct bfd_section_already_linked_hash_entry *
2916 bfd_section_already_linked_table_lookup (const char *name)
2918 return ((struct bfd_section_already_linked_hash_entry *)
2919 bfd_hash_lookup (&_bfd_section_already_linked_table, name,
2924 bfd_section_already_linked_table_insert
2925 (struct bfd_section_already_linked_hash_entry *already_linked_list,
2928 struct bfd_section_already_linked *l;
2930 /* Allocate the memory from the same obstack as the hash table is
2932 l = bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l);
2934 l->next = already_linked_list->entry;
2935 already_linked_list->entry = l;
2938 static struct bfd_hash_entry *
2939 already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED,
2940 struct bfd_hash_table *table,
2941 const char *string ATTRIBUTE_UNUSED)
2943 struct bfd_section_already_linked_hash_entry *ret =
2944 bfd_hash_allocate (table, sizeof *ret);
2952 bfd_section_already_linked_table_init (void)
2954 return bfd_hash_table_init_n (&_bfd_section_already_linked_table,
2955 already_linked_newfunc, 42);
2959 bfd_section_already_linked_table_free (void)
2961 bfd_hash_table_free (&_bfd_section_already_linked_table);
2964 /* This is used on non-ELF inputs. */
2967 _bfd_generic_section_already_linked (bfd *abfd, asection *sec)
2971 struct bfd_section_already_linked *l;
2972 struct bfd_section_already_linked_hash_entry *already_linked_list;
2975 if ((flags & SEC_LINK_ONCE) == 0)
2978 /* FIXME: When doing a relocatable link, we may have trouble
2979 copying relocations in other sections that refer to local symbols
2980 in the section being discarded. Those relocations will have to
2981 be converted somehow; as of this writing I'm not sure that any of
2982 the backends handle that correctly.
2984 It is tempting to instead not discard link once sections when
2985 doing a relocatable link (technically, they should be discarded
2986 whenever we are building constructors). However, that fails,
2987 because the linker winds up combining all the link once sections
2988 into a single large link once section, which defeats the purpose
2989 of having link once sections in the first place. */
2991 name = bfd_get_section_name (abfd, sec);
2993 already_linked_list = bfd_section_already_linked_table_lookup (name);
2995 for (l = already_linked_list->entry; l != NULL; l = l->next)
2997 bfd_boolean skip = FALSE;
2998 struct coff_comdat_info *s_comdat
2999 = bfd_coff_get_comdat_section (abfd, sec);
3000 struct coff_comdat_info *l_comdat
3001 = bfd_coff_get_comdat_section (l->sec->owner, l->sec);
3003 /* We may have 3 different sections on the list: group section,
3004 comdat section and linkonce section. SEC may be a linkonce or
3005 comdat section. We always ignore group section. For non-COFF
3006 inputs, we also ignore comdat section.
3008 FIXME: Is that safe to match a linkonce section with a comdat
3009 section for COFF inputs? */
3010 if ((l->sec->flags & SEC_GROUP) != 0)
3012 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour)
3014 if (s_comdat != NULL
3016 && strcmp (s_comdat->name, l_comdat->name) != 0)
3019 else if (l_comdat != NULL)
3024 /* The section has already been linked. See if we should
3026 switch (flags & SEC_LINK_DUPLICATES)
3031 case SEC_LINK_DUPLICATES_DISCARD:
3034 case SEC_LINK_DUPLICATES_ONE_ONLY:
3035 (*_bfd_error_handler)
3036 (_("%B: warning: ignoring duplicate section `%A'\n"),
3040 case SEC_LINK_DUPLICATES_SAME_CONTENTS:
3041 /* FIXME: We should really dig out the contents of both
3042 sections and memcmp them. The COFF/PE spec says that
3043 the Microsoft linker does not implement this
3044 correctly, so I'm not going to bother doing it
3047 case SEC_LINK_DUPLICATES_SAME_SIZE:
3048 if (sec->size != l->sec->size)
3049 (*_bfd_error_handler)
3050 (_("%B: warning: duplicate section `%A' has different size\n"),
3055 /* Set the output_section field so that lang_add_section
3056 does not create a lang_input_section structure for this
3057 section. Since there might be a symbol in the section
3058 being discarded, we must retain a pointer to the section
3059 which we are really going to use. */
3060 sec->output_section = bfd_abs_section_ptr;
3061 sec->kept_section = l->sec;
3067 /* This is the first section with this name. Record it. */
3068 bfd_section_already_linked_table_insert (already_linked_list, sec);