1 /* linker.c -- BFD linker routines
2 Copyright (C) 1993, 94 Free Software Foundation, Inc.
3 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
32 The linker uses three special entry points in the BFD target
33 vector. It is not necessary to write special routines for
34 these entry points when creating a new BFD back end, since
35 generic versions are provided. However, writing them can
36 speed up linking and make it use significantly less runtime
39 The first routine creates a hash table used by the other
40 routines. The second routine adds the symbols from an object
41 file to the hash table. The third routine takes all the
42 object files and links them together to create the output
43 file. These routines are designed so that the linker proper
44 does not need to know anything about the symbols in the object
45 files that it is linking. The linker merely arranges the
46 sections as directed by the linker script and lets BFD handle
47 the details of symbols and relocs.
49 The second routine and third routines are passed a pointer to
50 a <<struct bfd_link_info>> structure (defined in
51 <<bfdlink.h>>) which holds information relevant to the link,
52 including the linker hash table (which was created by the
53 first routine) and a set of callback functions to the linker
56 The generic linker routines are in <<linker.c>>, and use the
57 header file <<genlink.h>>. As of this writing, the only back
58 ends which have implemented versions of these routines are
59 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out
60 routines are used as examples throughout this section.
63 @* Creating a Linker Hash Table::
64 @* Adding Symbols to the Hash Table::
65 @* Performing the Final Link::
69 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions
71 Creating a linker hash table
73 @cindex _bfd_link_hash_table_create in target vector
74 @cindex target vector (_bfd_link_hash_table_create)
75 The linker routines must create a hash table, which must be
76 derived from <<struct bfd_link_hash_table>> described in
77 <<bfdlink.c>>. @xref{Hash Tables} for information on how to
78 create a derived hash table. This entry point is called using
79 the target vector of the linker output file.
81 The <<_bfd_link_hash_table_create>> entry point must allocate
82 and initialize an instance of the desired hash table. If the
83 back end does not require any additional information to be
84 stored with the entries in the hash table, the entry point may
85 simply create a <<struct bfd_link_hash_table>>. Most likely,
86 however, some additional information will be needed.
88 For example, with each entry in the hash table the a.out
89 linker keeps the index the symbol has in the final output file
90 (this index number is used so that when doing a relocateable
91 link the symbol index used in the output file can be quickly
92 filled in when copying over a reloc). The a.out linker code
93 defines the required structures and functions for a hash table
94 derived from <<struct bfd_link_hash_table>>. The a.out linker
95 hash table is created by the function
96 <<NAME(aout,link_hash_table_create)>>; it simply allocates
97 space for the hash table, initializes it, and returns a
100 When writing the linker routines for a new back end, you will
101 generally not know exactly which fields will be required until
102 you have finished. You should simply create a new hash table
103 which defines no additional fields, and then simply add fields
104 as they become necessary.
107 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions
109 Adding symbols to the hash table
111 @cindex _bfd_link_add_symbols in target vector
112 @cindex target vector (_bfd_link_add_symbols)
113 The linker proper will call the <<_bfd_link_add_symbols>>
114 entry point for each object file or archive which is to be
115 linked (typically these are the files named on the command
116 line, but some may also come from the linker script). The
117 entry point is responsible for examining the file. For an
118 object file, BFD must add any relevant symbol information to
119 the hash table. For an archive, BFD must determine which
120 elements of the archive should be used and adding them to the
123 The a.out version of this entry point is
124 <<NAME(aout,link_add_symbols)>>.
127 @* Differing file formats::
128 @* Adding symbols from an object file::
129 @* Adding symbols from an archive::
133 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table
135 Differing file formats
137 Normally all the files involved in a link will be of the same
138 format, but it is also possible to link together different
139 format object files, and the back end must support that. The
140 <<_bfd_link_add_symbols>> entry point is called via the target
141 vector of the file to be added. This has an important
142 consequence: the function may not assume that the hash table
143 is the type created by the corresponding
144 <<_bfd_link_hash_table_create>> vector. All the
145 <<_bfd_link_add_symbols>> function can assume about the hash
146 table is that it is derived from <<struct
147 bfd_link_hash_table>>.
149 Sometimes the <<_bfd_link_add_symbols>> function must store
150 some information in the hash table entry to be used by the
151 <<_bfd_final_link>> function. In such a case the <<creator>>
152 field of the hash table must be checked to make sure that the
153 hash table was created by an object file of the same format.
155 The <<_bfd_final_link>> routine must be prepared to handle a
156 hash entry without any extra information added by the
157 <<_bfd_link_add_symbols>> function. A hash entry without
158 extra information will also occur when the linker script
159 directs the linker to create a symbol. Note that, regardless
160 of how a hash table entry is added, all the fields will be
161 initialized to some sort of null value by the hash table entry
162 initialization function.
164 See <<ecoff_link_add_externals>> for an example of how to
165 check the <<creator>> field before saving information (in this
166 case, the ECOFF external symbol debugging information) in a
170 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table
172 Adding symbols from an object file
174 When the <<_bfd_link_add_symbols>> routine is passed an object
175 file, it must add all externally visible symbols in that
176 object file to the hash table. The actual work of adding the
177 symbol to the hash table is normally handled by the function
178 <<_bfd_generic_link_add_one_symbol>>. The
179 <<_bfd_link_add_symbols>> routine is responsible for reading
180 all the symbols from the object file and passing the correct
181 information to <<_bfd_generic_link_add_one_symbol>>.
183 The <<_bfd_link_add_symbols>> routine should not use
184 <<bfd_canonicalize_symtab>> to read the symbols. The point of
185 providing this routine is to avoid the overhead of converting
186 the symbols into generic <<asymbol>> structures.
188 @findex _bfd_generic_link_add_one_symbol
189 <<_bfd_generic_link_add_one_symbol>> handles the details of
190 combining common symbols, warning about multiple definitions,
191 and so forth. It takes arguments which describe the symbol to
192 add, notably symbol flags, a section, and an offset. The
193 symbol flags include such things as <<BSF_WEAK>> or
194 <<BSF_INDIRECT>>. The section is a section in the object
195 file, or something like <<bfd_und_section>> for an undefined
196 symbol or <<bfd_com_section>> for a common symbol.
198 If the <<_bfd_final_link>> routine is also going to need to
199 read the symbol information, the <<_bfd_link_add_symbols>>
200 routine should save it somewhere attached to the object file
201 BFD. However, the information should only be saved if the
202 <<keep_memory>> field of the <<info>> argument is true, so
203 that the <<-no-keep-memory>> linker switch is effective.
205 The a.out function which adds symbols from an object file is
206 <<aout_link_add_object_symbols>>, and most of the interesting
207 work is in <<aout_link_add_symbols>>. The latter saves
208 pointers to the hash tables entries created by
209 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number,
210 so that the <<_bfd_final_link>> routine does not have to call
211 the hash table lookup routine to locate the entry.
214 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table
216 Adding symbols from an archive
218 When the <<_bfd_link_add_symbols>> routine is passed an
219 archive, it must look through the symbols defined by the
220 archive and decide which elements of the archive should be
221 included in the link. For each such element it must call the
222 <<add_archive_element>> linker callback, and it must add the
223 symbols from the object file to the linker hash table.
225 @findex _bfd_generic_link_add_archive_symbols
226 In most cases the work of looking through the symbols in the
227 archive should be done by the
228 <<_bfd_generic_link_add_archive_symbols>> function. This
229 function builds a hash table from the archive symbol table and
230 looks through the list of undefined symbols to see which
231 elements should be included.
232 <<_bfd_generic_link_add_archive_symbols>> is passed a function
233 to call to make the final decision about adding an archive
234 element to the link and to do the actual work of adding the
235 symbols to the linker hash table.
237 The function passed to
238 <<_bfd_generic_link_add_archive_symbols>> must read the
239 symbols of the archive element and decide whether the archive
240 element should be included in the link. If the element is to
241 be included, the <<add_archive_element>> linker callback
242 routine must be called with the element as an argument, and
243 the elements symbols must be added to the linker hash table
244 just as though the element had itself been passed to the
245 <<_bfd_link_add_symbols>> function.
247 When the a.out <<_bfd_link_add_symbols>> function receives an
248 archive, it calls <<_bfd_generic_link_add_archive_symbols>>
249 passing <<aout_link_check_archive_element>> as the function
250 argument. <<aout_link_check_archive_element>> calls
251 <<aout_link_check_ar_symbols>>. If the latter decides to add
252 the element (an element is only added if it provides a real,
253 non-common, definition for a previously undefined or common
254 symbol) it calls the <<add_archive_element>> callback and then
255 <<aout_link_check_archive_element>> calls
256 <<aout_link_add_symbols>> to actually add the symbols to the
259 The ECOFF back end is unusual in that it does not normally
260 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF
261 archives already contain a hash table of symbols. The ECOFF
262 back end searches the archive itself to avoid the overhead of
263 creating a new hash table.
266 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions
268 Performing the final link
270 @cindex _bfd_link_final_link in target vector
271 @cindex target vector (_bfd_final_link)
272 When all the input files have been processed, the linker calls
273 the <<_bfd_final_link>> entry point of the output BFD. This
274 routine is responsible for producing the final output file,
275 which has several aspects. It must relocate the contents of
276 the input sections and copy the data into the output sections.
277 It must build an output symbol table including any local
278 symbols from the input files and the global symbols from the
279 hash table. When producing relocateable output, it must
280 modify the input relocs and write them into the output file.
281 There may also be object format dependent work to be done.
283 The linker will also call the <<write_object_contents>> entry
284 point when the BFD is closed. The two entry points must work
285 together in order to produce the correct output file.
287 The details of how this works are inevitably dependent upon
288 the specific object file format. The a.out
289 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>.
292 @* Information provided by the linker::
293 @* Relocating the section contents::
294 @* Writing the symbol table::
298 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link
300 Information provided by the linker
302 Before the linker calls the <<_bfd_final_link>> entry point,
303 it sets up some data structures for the function to use.
305 The <<input_bfds>> field of the <<bfd_link_info>> structure
306 will point to a list of all the input files included in the
307 link. These files are linked through the <<link_next>> field
308 of the <<bfd>> structure.
310 Each section in the output file will have a list of
311 <<link_order>> structures attached to the <<link_order_head>>
312 field (the <<link_order>> structure is defined in
313 <<bfdlink.h>>). These structures describe how to create the
314 contents of the output section in terms of the contents of
315 various input sections, fill constants, and, eventually, other
316 types of information. They also describe relocs that must be
317 created by the BFD backend, but do not correspond to any input
318 file; this is used to support -Ur, which builds constructors
319 while generating a relocateable object file.
322 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link
324 Relocating the section contents
326 The <<_bfd_final_link>> function should look through the
327 <<link_order>> structures attached to each section of the
328 output file. Each <<link_order>> structure should either be
329 handled specially, or it should be passed to the function
330 <<_bfd_default_link_order>> which will do the right thing
331 (<<_bfd_default_link_order>> is defined in <<linker.c>>).
333 For efficiency, a <<link_order>> of type
334 <<bfd_indirect_link_order>> whose associated section belongs
335 to a BFD of the same format as the output BFD must be handled
336 specially. This type of <<link_order>> describes part of an
337 output section in terms of a section belonging to one of the
338 input files. The <<_bfd_final_link>> function should read the
339 contents of the section and any associated relocs, apply the
340 relocs to the section contents, and write out the modified
341 section contents. If performing a relocateable link, the
342 relocs themselves must also be modified and written out.
344 @findex _bfd_relocate_contents
345 @findex _bfd_final_link_relocate
346 The functions <<_bfd_relocate_contents>> and
347 <<_bfd_final_link_relocate>> provide some general support for
348 performing the actual relocations, notably overflow checking.
349 Their arguments include information about the symbol the
350 relocation is against and a <<reloc_howto_type>> argument
351 which describes the relocation to perform. These functions
352 are defined in <<reloc.c>>.
354 The a.out function which handles reading, relocating, and
355 writing section contents is <<aout_link_input_section>>. The
356 actual relocation is done in <<aout_link_input_section_std>>
357 and <<aout_link_input_section_ext>>.
360 Writing the symbol table, , Relocating the section contents, Performing the Final Link
362 Writing the symbol table
364 The <<_bfd_final_link>> function must gather all the symbols
365 in the input files and write them out. It must also write out
366 all the symbols in the global hash table. This must be
367 controlled by the <<strip>> and <<discard>> fields of the
368 <<bfd_link_info>> structure.
370 The local symbols of the input files will not have been
371 entered into the linker hash table. The <<_bfd_final_link>>
372 routine must consider each input file and include the symbols
373 in the output file. It may be convenient to do this when
374 looking through the <<link_order>> structures, or it may be
375 done by stepping through the <<input_bfds>> list.
377 The <<_bfd_final_link>> routine must also traverse the global
378 hash table to gather all the externally visible symbols. It
379 is possible that most of the externally visible symbols may be
380 written out when considering the symbols of each input file,
381 but it is still necessary to traverse the hash table since the
382 linker script may have defined some symbols that are not in
383 any of the input files. The <<written>> field in the
384 <<bfd_link_hash_entry>> structure may be used to determine
385 which entries in the hash table have not already been written
388 The <<strip>> field of the <<bfd_link_info>> structure
389 controls which symbols are written out. The possible values
390 are listed in <<bfdlink.h>>. If the value is <<strip_some>>,
391 then the <<keep_hash>> field of the <<bfd_link_info>>
392 structure is a hash table of symbols to keep; each symbol
393 should be looked up in this hash table, and only symbols which
394 are present should be included in the output file.
396 If the <<strip>> field of the <<bfd_link_info>> structure
397 permits local symbols to be written out, the <<discard>> field
398 is used to further controls which local symbols are included
399 in the output file. If the value is <<discard_l>>, then all
400 local symbols which begin with a certain prefix are discarded;
401 this prefix is described by the <<lprefix>> and
402 <<lprefix_len>> fields of the <<bfd_link_info>> structure.
404 The a.out backend handles symbols by calling
405 <<aout_link_write_symbols>> on each input BFD and then
406 traversing the global hash table with the function
407 <<aout_link_write_other_symbol>>. It builds a string table
408 while writing out the symbols, which is written to the output
409 file at the end of <<NAME(aout,final_link)>>.
412 static struct bfd_hash_entry *generic_link_hash_newfunc
413 PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *,
415 static boolean generic_link_read_symbols
417 static boolean generic_link_add_symbols
418 PARAMS ((bfd *, struct bfd_link_info *, boolean collect));
419 static boolean generic_link_add_object_symbols
420 PARAMS ((bfd *, struct bfd_link_info *, boolean collect));
421 static boolean generic_link_check_archive_element_no_collect
422 PARAMS ((bfd *, struct bfd_link_info *, boolean *pneeded));
423 static boolean generic_link_check_archive_element_collect
424 PARAMS ((bfd *, struct bfd_link_info *, boolean *pneeded));
425 static boolean generic_link_check_archive_element
426 PARAMS ((bfd *, struct bfd_link_info *, boolean *pneeded, boolean collect));
427 static boolean generic_link_add_symbol_list
428 PARAMS ((bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **,
430 static boolean generic_add_output_symbol
431 PARAMS ((bfd *, size_t *psymalloc, asymbol *));
432 static boolean default_fill_link_order
433 PARAMS ((bfd *, struct bfd_link_info *, asection *,
434 struct bfd_link_order *));
435 static boolean default_indirect_link_order
436 PARAMS ((bfd *, struct bfd_link_info *, asection *,
437 struct bfd_link_order *));
439 /* The link hash table structure is defined in bfdlink.h. It provides
440 a base hash table which the backend specific hash tables are built
443 /* Routine to create an entry in the link hash table. */
445 struct bfd_hash_entry *
446 _bfd_link_hash_newfunc (entry, table, string)
447 struct bfd_hash_entry *entry;
448 struct bfd_hash_table *table;
451 struct bfd_link_hash_entry *ret = (struct bfd_link_hash_entry *) entry;
453 /* Allocate the structure if it has not already been allocated by a
455 if (ret == (struct bfd_link_hash_entry *) NULL)
456 ret = ((struct bfd_link_hash_entry *)
457 bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry)));
458 if (ret == (struct bfd_link_hash_entry *) NULL)
460 bfd_set_error (bfd_error_no_memory);
464 /* Call the allocation method of the superclass. */
465 ret = ((struct bfd_link_hash_entry *)
466 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
470 /* Initialize the local fields. */
471 ret->type = bfd_link_hash_new;
472 ret->written = false;
476 return (struct bfd_hash_entry *) ret;
479 /* Initialize a link hash table. The BFD argument is the one
480 responsible for creating this table. */
483 _bfd_link_hash_table_init (table, abfd, newfunc)
484 struct bfd_link_hash_table *table;
486 struct bfd_hash_entry *(*newfunc) PARAMS ((struct bfd_hash_entry *,
487 struct bfd_hash_table *,
490 table->creator = abfd->xvec;
491 table->undefs = NULL;
492 table->undefs_tail = NULL;
493 return bfd_hash_table_init (&table->table, newfunc);
496 /* Look up a symbol in a link hash table. If follow is true, we
497 follow bfd_link_hash_indirect and bfd_link_hash_warning links to
500 struct bfd_link_hash_entry *
501 bfd_link_hash_lookup (table, string, create, copy, follow)
502 struct bfd_link_hash_table *table;
508 struct bfd_link_hash_entry *ret;
510 ret = ((struct bfd_link_hash_entry *)
511 bfd_hash_lookup (&table->table, string, create, copy));
513 if (follow && ret != (struct bfd_link_hash_entry *) NULL)
515 while (ret->type == bfd_link_hash_indirect
516 || ret->type == bfd_link_hash_warning)
523 /* Traverse a generic link hash table. The only reason this is not a
524 macro is to do better type checking. This code presumes that an
525 argument passed as a struct bfd_hash_entry * may be caught as a
526 struct bfd_link_hash_entry * with no explicit cast required on the
530 bfd_link_hash_traverse (table, func, info)
531 struct bfd_link_hash_table *table;
532 boolean (*func) PARAMS ((struct bfd_link_hash_entry *, PTR));
535 bfd_hash_traverse (&table->table,
536 ((boolean (*) PARAMS ((struct bfd_hash_entry *, PTR)))
541 /* Add a symbol to the linker hash table undefs list. */
544 bfd_link_add_undef (table, h)
545 struct bfd_link_hash_table *table;
546 struct bfd_link_hash_entry *h;
548 BFD_ASSERT (h->next == NULL);
549 if (table->undefs_tail != (struct bfd_link_hash_entry *) NULL)
550 table->undefs_tail->next = h;
551 if (table->undefs == (struct bfd_link_hash_entry *) NULL)
553 table->undefs_tail = h;
556 /* Routine to create an entry in an generic link hash table. */
558 static struct bfd_hash_entry *
559 generic_link_hash_newfunc (entry, table, string)
560 struct bfd_hash_entry *entry;
561 struct bfd_hash_table *table;
564 struct generic_link_hash_entry *ret =
565 (struct generic_link_hash_entry *) entry;
567 /* Allocate the structure if it has not already been allocated by a
569 if (ret == (struct generic_link_hash_entry *) NULL)
570 ret = ((struct generic_link_hash_entry *)
571 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry)));
572 if (ret == (struct generic_link_hash_entry *) NULL)
574 bfd_set_error (bfd_error_no_memory);
578 /* Call the allocation method of the superclass. */
579 ret = ((struct generic_link_hash_entry *)
580 _bfd_link_hash_newfunc ((struct bfd_hash_entry *) ret,
585 /* Set local fields. */
589 return (struct bfd_hash_entry *) ret;
592 /* Create an generic link hash table. */
594 struct bfd_link_hash_table *
595 _bfd_generic_link_hash_table_create (abfd)
598 struct generic_link_hash_table *ret;
600 ret = ((struct generic_link_hash_table *)
601 malloc (sizeof (struct generic_link_hash_table)));
604 bfd_set_error (bfd_error_no_memory);
605 return (struct bfd_link_hash_table *) NULL;
607 if (! _bfd_link_hash_table_init (&ret->root, abfd,
608 generic_link_hash_newfunc))
611 return (struct bfd_link_hash_table *) NULL;
616 /* Grab the symbols for an object file when doing a generic link. We
617 store the symbols in the outsymbols field. We need to keep them
618 around for the entire link to ensure that we only read them once.
619 If we read them multiple times, we might wind up with relocs and
620 the hash table pointing to different instances of the symbol
624 generic_link_read_symbols (abfd)
627 if (abfd->outsymbols == (asymbol **) NULL)
632 symsize = bfd_get_symtab_upper_bound (abfd);
635 abfd->outsymbols = (asymbol **) bfd_alloc (abfd, symsize);
636 if (abfd->outsymbols == NULL && symsize != 0)
638 bfd_set_error (bfd_error_no_memory);
641 symcount = bfd_canonicalize_symtab (abfd, abfd->outsymbols);
644 abfd->symcount = symcount;
650 /* Generic function to add symbols to from an object file to the
651 global hash table. This version does not automatically collect
652 constructors by name. */
655 _bfd_generic_link_add_symbols (abfd, info)
657 struct bfd_link_info *info;
659 return generic_link_add_symbols (abfd, info, false);
662 /* Generic function to add symbols from an object file to the global
663 hash table. This version automatically collects constructors by
664 name, as the collect2 program does. It should be used for any
665 target which does not provide some other mechanism for setting up
666 constructors and destructors; these are approximately those targets
667 for which gcc uses collect2 and do not support stabs. */
670 _bfd_generic_link_add_symbols_collect (abfd, info)
672 struct bfd_link_info *info;
674 return generic_link_add_symbols (abfd, info, true);
677 /* Add symbols from an object file to the global hash table. */
680 generic_link_add_symbols (abfd, info, collect)
682 struct bfd_link_info *info;
687 switch (bfd_get_format (abfd))
690 ret = generic_link_add_object_symbols (abfd, info, collect);
693 ret = (_bfd_generic_link_add_archive_symbols
696 ? generic_link_check_archive_element_collect
697 : generic_link_check_archive_element_no_collect)));
700 bfd_set_error (bfd_error_wrong_format);
707 /* Add symbols from an object file to the global hash table. */
710 generic_link_add_object_symbols (abfd, info, collect)
712 struct bfd_link_info *info;
715 if (! generic_link_read_symbols (abfd))
717 return generic_link_add_symbol_list (abfd, info,
718 _bfd_generic_link_get_symcount (abfd),
719 _bfd_generic_link_get_symbols (abfd),
723 /* We build a hash table of all symbols defined in an archive. */
725 /* An archive symbol may be defined by multiple archive elements.
726 This linked list is used to hold the elements. */
730 struct archive_list *next;
734 /* An entry in an archive hash table. */
736 struct archive_hash_entry
738 struct bfd_hash_entry root;
739 /* Where the symbol is defined. */
740 struct archive_list *defs;
743 /* An archive hash table itself. */
745 struct archive_hash_table
747 struct bfd_hash_table table;
750 static struct bfd_hash_entry *archive_hash_newfunc
751 PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
752 static boolean archive_hash_table_init
753 PARAMS ((struct archive_hash_table *,
754 struct bfd_hash_entry *(*) (struct bfd_hash_entry *,
755 struct bfd_hash_table *,
758 /* Create a new entry for an archive hash table. */
760 static struct bfd_hash_entry *
761 archive_hash_newfunc (entry, table, string)
762 struct bfd_hash_entry *entry;
763 struct bfd_hash_table *table;
766 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry;
768 /* Allocate the structure if it has not already been allocated by a
770 if (ret == (struct archive_hash_entry *) NULL)
771 ret = ((struct archive_hash_entry *)
772 bfd_hash_allocate (table, sizeof (struct archive_hash_entry)));
773 if (ret == (struct archive_hash_entry *) NULL)
775 bfd_set_error (bfd_error_no_memory);
779 /* Call the allocation method of the superclass. */
780 ret = ((struct archive_hash_entry *)
781 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
785 /* Initialize the local fields. */
786 ret->defs = (struct archive_list *) NULL;
789 return (struct bfd_hash_entry *) ret;
792 /* Initialize an archive hash table. */
795 archive_hash_table_init (table, newfunc)
796 struct archive_hash_table *table;
797 struct bfd_hash_entry *(*newfunc) PARAMS ((struct bfd_hash_entry *,
798 struct bfd_hash_table *,
801 return bfd_hash_table_init (&table->table, newfunc);
804 /* Look up an entry in an archive hash table. */
806 #define archive_hash_lookup(t, string, create, copy) \
807 ((struct archive_hash_entry *) \
808 bfd_hash_lookup (&(t)->table, (string), (create), (copy)))
810 /* Free an archive hash table. */
812 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table)
814 /* Generic function to add symbols from an archive file to the global
815 hash file. This function presumes that the archive symbol table
816 has already been read in (this is normally done by the
817 bfd_check_format entry point). It looks through the undefined and
818 common symbols and searches the archive symbol table for them. If
819 it finds an entry, it includes the associated object file in the
822 The old linker looked through the archive symbol table for
823 undefined symbols. We do it the other way around, looking through
824 undefined symbols for symbols defined in the archive. The
825 advantage of the newer scheme is that we only have to look through
826 the list of undefined symbols once, whereas the old method had to
827 re-search the symbol table each time a new object file was added.
829 The CHECKFN argument is used to see if an object file should be
830 included. CHECKFN should set *PNEEDED to true if the object file
831 should be included, and must also call the bfd_link_info
832 add_archive_element callback function and handle adding the symbols
833 to the global hash table. CHECKFN should only return false if some
834 sort of error occurs.
836 For some formats, such as a.out, it is possible to look through an
837 object file but not actually include it in the link. The
838 archive_pass field in a BFD is used to avoid checking the symbols
839 of an object files too many times. When an object is included in
840 the link, archive_pass is set to -1. If an object is scanned but
841 not included, archive_pass is set to the pass number. The pass
842 number is incremented each time a new object file is included. The
843 pass number is used because when a new object file is included it
844 may create new undefined symbols which cause a previously examined
845 object file to be included. */
848 _bfd_generic_link_add_archive_symbols (abfd, info, checkfn)
850 struct bfd_link_info *info;
851 boolean (*checkfn) PARAMS ((bfd *, struct bfd_link_info *,
856 register carsym *arsym;
858 struct archive_hash_table arsym_hash;
860 struct bfd_link_hash_entry **pundef;
862 if (! bfd_has_map (abfd))
864 bfd_set_error (bfd_error_no_symbols);
868 arsyms = bfd_ardata (abfd)->symdefs;
869 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count;
871 /* In order to quickly determine whether an symbol is defined in
872 this archive, we build a hash table of the symbols. */
873 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc))
875 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++)
877 struct archive_hash_entry *arh;
878 struct archive_list *l, **pp;
880 arh = archive_hash_lookup (&arsym_hash, arsym->name, true, false);
881 if (arh == (struct archive_hash_entry *) NULL)
883 l = (struct archive_list *)
884 obstack_alloc (&(&(&arsym_hash)->table)->memory,
885 sizeof (struct archive_list));
888 bfd_set_error (bfd_error_no_memory);
892 for (pp = &arh->defs;
893 *pp != (struct archive_list *) NULL;
902 /* New undefined symbols are added to the end of the list, so we
903 only need to look through it once. */
904 pundef = &info->hash->undefs;
905 while (*pundef != (struct bfd_link_hash_entry *) NULL)
907 struct bfd_link_hash_entry *h;
908 struct archive_hash_entry *arh;
909 struct archive_list *l;
913 /* When a symbol is defined, it is not necessarily removed from
915 if (h->type != bfd_link_hash_undefined
916 && h->type != bfd_link_hash_common)
918 /* Remove this entry from the list, for general cleanliness
919 and because we are going to look through the list again
920 if we search any more libraries. We can't remove the
921 entry if it is the tail, because that would lose any
922 entries we add to the list later on. */
923 if (*pundef != info->hash->undefs_tail)
924 *pundef = (*pundef)->next;
926 pundef = &(*pundef)->next;
930 /* Look for this symbol in the archive symbol map. */
931 arh = archive_hash_lookup (&arsym_hash, h->root.string, false, false);
932 if (arh == (struct archive_hash_entry *) NULL)
934 pundef = &(*pundef)->next;
938 /* Look at all the objects which define this symbol. */
939 for (l = arh->defs; l != (struct archive_list *) NULL; l = l->next)
944 /* If the symbol has gotten defined along the way, quit. */
945 if (h->type != bfd_link_hash_undefined
946 && h->type != bfd_link_hash_common)
949 element = bfd_get_elt_at_index (abfd, l->indx);
950 if (element == (bfd *) NULL)
953 /* If we've already included this element, or if we've
954 already checked it on this pass, continue. */
955 if (element->archive_pass == -1
956 || element->archive_pass == pass)
959 /* If we can't figure this element out, just ignore it. */
960 if (! bfd_check_format (element, bfd_object))
962 element->archive_pass = -1;
966 /* CHECKFN will see if this element should be included, and
967 go ahead and include it if appropriate. */
968 if (! (*checkfn) (element, info, &needed))
972 element->archive_pass = pass;
975 element->archive_pass = -1;
977 /* Increment the pass count to show that we may need to
978 recheck object files which were already checked. */
983 pundef = &(*pundef)->next;
986 archive_hash_table_free (&arsym_hash);
991 archive_hash_table_free (&arsym_hash);
995 /* See if we should include an archive element. This version is used
996 when we do not want to automatically collect constructors based on
997 the symbol name, presumably because we have some other mechanism
1001 generic_link_check_archive_element_no_collect (abfd, info, pneeded)
1003 struct bfd_link_info *info;
1006 return generic_link_check_archive_element (abfd, info, pneeded, false);
1009 /* See if we should include an archive element. This version is used
1010 when we want to automatically collect constructors based on the
1011 symbol name, as collect2 does. */
1014 generic_link_check_archive_element_collect (abfd, info, pneeded)
1016 struct bfd_link_info *info;
1019 return generic_link_check_archive_element (abfd, info, pneeded, true);
1022 /* See if we should include an archive element. Optionally collect
1026 generic_link_check_archive_element (abfd, info, pneeded, collect)
1028 struct bfd_link_info *info;
1032 asymbol **pp, **ppend;
1036 if (! generic_link_read_symbols (abfd))
1039 pp = _bfd_generic_link_get_symbols (abfd);
1040 ppend = pp + _bfd_generic_link_get_symcount (abfd);
1041 for (; pp < ppend; pp++)
1044 struct bfd_link_hash_entry *h;
1048 /* We are only interested in globally visible symbols. */
1049 if (! bfd_is_com_section (p->section)
1050 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0)
1053 /* We are only interested if we know something about this
1054 symbol, and it is undefined or common. An undefined weak
1055 symbol (type bfd_link_hash_weak) is not considered to be a
1056 reference when pulling files out of an archive. See the SVR4
1058 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), false,
1060 if (h == (struct bfd_link_hash_entry *) NULL
1061 || (h->type != bfd_link_hash_undefined
1062 && h->type != bfd_link_hash_common))
1065 /* P is a symbol we are looking for. */
1067 if (! bfd_is_com_section (p->section))
1069 bfd_size_type symcount;
1072 /* This object file defines this symbol, so pull it in. */
1073 if (! (*info->callbacks->add_archive_element) (info, abfd,
1074 bfd_asymbol_name (p)))
1076 symcount = _bfd_generic_link_get_symcount (abfd);
1077 symbols = _bfd_generic_link_get_symbols (abfd);
1078 if (! generic_link_add_symbol_list (abfd, info, symcount,
1085 /* P is a common symbol. */
1087 if (h->type == bfd_link_hash_undefined)
1091 symbfd = h->u.undef.abfd;
1092 if (symbfd == (bfd *) NULL)
1094 /* This symbol was created as undefined from outside
1095 BFD. We assume that we should link in the object
1096 file. This is for the -u option in the linker. */
1097 if (! (*info->callbacks->add_archive_element)
1098 (info, abfd, bfd_asymbol_name (p)))
1104 /* Turn the symbol into a common symbol but do not link in
1105 the object file. This is how a.out works. Object
1106 formats that require different semantics must implement
1107 this function differently. This symbol is already on the
1108 undefs list. We add the section to a common section
1109 attached to symbfd to ensure that it is in a BFD which
1110 will be linked in. */
1111 h->type = bfd_link_hash_common;
1112 h->u.c.size = bfd_asymbol_value (p);
1113 if (p->section == &bfd_com_section)
1114 h->u.c.section = bfd_make_section_old_way (symbfd, "COMMON");
1116 h->u.c.section = bfd_make_section_old_way (symbfd,
1118 h->u.c.section->flags = SEC_ALLOC;
1122 /* Adjust the size of the common symbol if necessary. This
1123 is how a.out works. Object formats that require
1124 different semantics must implement this function
1126 if (bfd_asymbol_value (p) > h->u.c.size)
1127 h->u.c.size = bfd_asymbol_value (p);
1131 /* This archive element is not needed. */
1135 /* Add the symbols from an object file to the global hash table. ABFD
1136 is the object file. INFO is the linker information. SYMBOL_COUNT
1137 is the number of symbols. SYMBOLS is the list of symbols. COLLECT
1138 is true if constructors should be automatically collected by name
1139 as is done by collect2. */
1142 generic_link_add_symbol_list (abfd, info, symbol_count, symbols, collect)
1144 struct bfd_link_info *info;
1145 bfd_size_type symbol_count;
1149 asymbol **pp, **ppend;
1152 ppend = symbols + symbol_count;
1153 for (; pp < ppend; pp++)
1159 if ((p->flags & (BSF_INDIRECT
1164 || bfd_get_section (p) == &bfd_und_section
1165 || bfd_is_com_section (bfd_get_section (p))
1166 || bfd_get_section (p) == &bfd_ind_section)
1170 struct generic_link_hash_entry *h;
1172 name = bfd_asymbol_name (p);
1173 if ((p->flags & BSF_INDIRECT) != 0
1174 || p->section == &bfd_ind_section)
1175 string = bfd_asymbol_name ((asymbol *) p->value);
1176 else if ((p->flags & BSF_WARNING) != 0)
1178 /* The name of P is actually the warning string, and the
1179 value is actually a pointer to the symbol to warn
1182 name = bfd_asymbol_name ((asymbol *) p->value);
1188 if (! (_bfd_generic_link_add_one_symbol
1189 (info, abfd, name, p->flags, bfd_get_section (p),
1190 p->value, string, false, collect,
1191 (struct bfd_link_hash_entry **) &h)))
1194 /* Save the BFD symbol so that we don't lose any backend
1195 specific information that may be attached to it. We only
1196 want this one if it gives more information than the
1197 existing one; we don't want to replace a defined symbol
1198 with an undefined one. This routine may be called with a
1199 hash table other than the generic hash table, so we only
1200 do this if we are certain that the hash table is a
1202 if (info->hash->creator == abfd->xvec)
1204 if (h->sym == (asymbol *) NULL
1205 || (bfd_get_section (p) != &bfd_und_section
1206 && (! bfd_is_com_section (bfd_get_section (p))
1207 || (bfd_get_section (h->sym) == &bfd_und_section))))
1210 /* BSF_OLD_COMMON is a hack to support COFF reloc
1211 reading, and it should go away when the COFF
1212 linker is switched to the new version. */
1213 if (bfd_is_com_section (bfd_get_section (p)))
1214 p->flags |= BSF_OLD_COMMON;
1217 /* Store a back pointer from the symbol to the hash
1218 table entry for the benefit of relaxation code until
1219 it gets rewritten to not use asymbol structures. */
1228 /* We use a state table to deal with adding symbols from an object
1229 file. The first index into the state table describes the symbol
1230 from the object file. The second index into the state table is the
1231 type of the symbol in the hash table. */
1233 /* The symbol from the object file is turned into one of these row
1238 UNDEF_ROW, /* Undefined. */
1239 UNDEFW_ROW, /* Weak undefined. */
1240 DEF_ROW, /* Defined. */
1241 DEFW_ROW, /* Weak defined. */
1242 COMMON_ROW, /* Common. */
1243 INDR_ROW, /* Indirect. */
1244 WARN_ROW, /* Warning. */
1245 SET_ROW /* Member of set. */
1248 /* The actions to take in the state table. */
1253 UND, /* Mark symbol undefined. */
1254 WEAK, /* Mark symbol weak undefined. */
1255 DEF, /* Mark symbol defined. */
1256 COM, /* Mark symbol common. */
1257 CREF, /* Possibly warn about common reference to defined symbol. */
1258 CDEF, /* Define existing common symbol. */
1259 NOACT, /* No action. */
1260 BIG, /* Mark symbol common using largest size. */
1261 MDEF, /* Multiple definition error. */
1262 IND, /* Make indirect symbol. */
1263 SET, /* Add value to set. */
1264 MWARN, /* Make warning symbol. */
1265 WARN, /* Issue warning. */
1266 CYCLE, /* Repeat with symbol pointed to. */
1267 WARNC /* Issue warning and then CYCLE. */
1270 /* The state table itself. The first index is a link_row and the
1271 second index is a bfd_link_hash_type. */
1273 static const enum link_action link_action[8][7] =
1275 /* current\prev new undef weak def com indr warn */
1276 /* UNDEF_ROW */ {UND, NOACT, NOACT, NOACT, NOACT, CYCLE, WARNC },
1277 /* UNDEFW_ROW */ {WEAK, WEAK, NOACT, NOACT, NOACT, CYCLE, WARNC },
1278 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, CDEF, CYCLE, CYCLE },
1279 /* DEFW_ROW */ {DEF, DEF, DEF, NOACT, NOACT, CYCLE, CYCLE },
1280 /* COMMON_ROW */ {COM, COM, COM, CREF, BIG, CYCLE, WARNC },
1281 /* INDR_ROW */ {IND, IND, IND, MDEF, MDEF, MDEF, WARNC },
1282 /* WARN_ROW */ {MWARN, WARN, WARN, MWARN, MWARN, MWARN, NOACT },
1283 /* SET_ROW */ {SET, SET, SET, SET, SET, CYCLE, WARNC }
1286 /* Add a symbol to the global hash table.
1287 ABFD is the BFD the symbol comes from.
1288 NAME is the name of the symbol.
1289 FLAGS is the BSF_* bits associated with the symbol.
1290 SECTION is the section in which the symbol is defined; this may be
1291 bfd_und_section or bfd_com_section.
1292 VALUE is the value of the symbol, relative to the section.
1293 STRING is used for either an indirect symbol, in which case it is
1294 the name of the symbol to indirect to, or a warning symbol, in
1295 which case it is the warning string.
1296 COPY is true if NAME or STRING must be copied into locally
1297 allocated memory if they need to be saved.
1298 COLLECT is true if we should automatically collect gcc constructor
1299 or destructor names as collect2 does.
1300 HASHP, if not NULL, is a place to store the created hash table
1301 entry; if *HASHP is not NULL, the caller has already looked up
1302 the hash table entry, and stored it in *HASHP. */
1305 _bfd_generic_link_add_one_symbol (info, abfd, name, flags, section, value,
1306 string, copy, collect, hashp)
1307 struct bfd_link_info *info;
1316 struct bfd_link_hash_entry **hashp;
1319 struct bfd_link_hash_entry *h;
1322 if (section == &bfd_ind_section
1323 || (flags & BSF_INDIRECT) != 0)
1325 else if ((flags & BSF_WARNING) != 0)
1327 else if ((flags & BSF_CONSTRUCTOR) != 0)
1329 else if (section == &bfd_und_section)
1331 if ((flags & BSF_WEAK) != 0)
1336 else if ((flags & BSF_WEAK) != 0)
1338 else if (bfd_is_com_section (section))
1343 if (hashp != NULL && *hashp != NULL)
1346 BFD_ASSERT (strcmp (h->root.string, name) == 0);
1350 h = bfd_link_hash_lookup (info->hash, name, true, copy, false);
1359 if (info->notice_hash != (struct bfd_hash_table *) NULL
1360 && (bfd_hash_lookup (info->notice_hash, name, false, false)
1361 != (struct bfd_hash_entry *) NULL))
1363 if (! (*info->callbacks->notice) (info, name, abfd, section, value))
1367 if (hashp != (struct bfd_link_hash_entry **) NULL)
1372 enum link_action action;
1375 action = link_action[(int) row][(int) h->type];
1381 h->type = bfd_link_hash_undefined;
1382 h->u.undef.abfd = abfd;
1383 bfd_link_add_undef (info->hash, h);
1386 h->type = bfd_link_hash_weak;
1387 h->u.undef.abfd = abfd;
1390 BFD_ASSERT (h->type == bfd_link_hash_common);
1391 if (! ((*info->callbacks->multiple_common)
1393 h->u.c.section->owner, bfd_link_hash_common, h->u.c.size,
1394 abfd, bfd_link_hash_defined, (bfd_vma) 0)))
1398 h->type = bfd_link_hash_defined;
1399 h->u.def.section = section;
1400 h->u.def.value = value;
1402 /* If we have been asked to, we act like collect2 and
1403 identify all functions that might be global constructors
1404 and destructors and pass them up in a callback. We only
1405 do this for certain object file types, since many object
1406 file types can handle this automatically. */
1407 if (collect && name[0] == '_')
1411 /* A constructor or destructor name starts like this:
1412 _+GLOBAL_[_.$][ID][_.$]
1413 where the first [_.$] and the second are the same
1414 character (we accept any character there, in case a
1415 new object file format comes along with even worse
1416 naming restrictions). */
1418 #define CONS_PREFIX "GLOBAL_"
1419 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1)
1425 && strncmp (s, CONS_PREFIX, CONS_PREFIX_LEN - 1) == 0)
1429 c = s[CONS_PREFIX_LEN + 1];
1430 if ((c == 'I' || c == 'D')
1431 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2])
1433 if (! ((*info->callbacks->constructor)
1435 c == 'I' ? true : false,
1436 name, abfd, section, value)))
1444 if (h->type == bfd_link_hash_new)
1445 bfd_link_add_undef (info->hash, h);
1446 h->type = bfd_link_hash_common;
1447 h->u.c.size = value;
1448 if (section == &bfd_com_section)
1450 h->u.c.section = bfd_make_section_old_way (abfd, "COMMON");
1451 h->u.c.section->flags = SEC_ALLOC;
1453 else if (section->owner != abfd)
1455 h->u.c.section = bfd_make_section_old_way (abfd, section->name);
1456 h->u.c.section->flags = SEC_ALLOC;
1459 h->u.c.section = section;
1464 BFD_ASSERT (h->type == bfd_link_hash_common);
1465 if (! ((*info->callbacks->multiple_common)
1467 h->u.c.section->owner, bfd_link_hash_common, h->u.c.size,
1468 abfd, bfd_link_hash_common, value)))
1470 if (value > h->u.c.size)
1471 h->u.c.size = value;
1474 BFD_ASSERT (h->type == bfd_link_hash_defined);
1475 if (! ((*info->callbacks->multiple_common)
1477 h->u.def.section->owner, bfd_link_hash_defined, (bfd_vma) 0,
1478 abfd, bfd_link_hash_common, value)))
1488 case bfd_link_hash_defined:
1489 msec = h->u.def.section;
1490 mval = h->u.def.value;
1492 case bfd_link_hash_common:
1493 msec = &bfd_com_section;
1496 case bfd_link_hash_indirect:
1497 msec = &bfd_ind_section;
1504 if (! ((*info->callbacks->multiple_definition)
1505 (info, name, msec->owner, msec, mval, abfd, section,
1512 struct bfd_link_hash_entry *inh;
1514 /* STRING is the name of the symbol we want to indirect
1516 inh = bfd_link_hash_lookup (info->hash, string, true, copy,
1518 if (inh == (struct bfd_link_hash_entry *) NULL)
1520 if (inh->type == bfd_link_hash_new)
1522 inh->type = bfd_link_hash_undefined;
1523 inh->u.undef.abfd = abfd;
1524 bfd_link_add_undef (info->hash, inh);
1526 h->type = bfd_link_hash_indirect;
1531 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR,
1532 abfd, section, value))
1537 if (h->u.i.warning != NULL)
1539 if (! (*info->callbacks->warning) (info, h->u.i.warning))
1541 /* Only issue a warning once. */
1542 h->u.i.warning = NULL;
1553 struct bfd_link_hash_entry *sub;
1555 /* STRING is the warning to give. */
1556 sub = ((struct bfd_link_hash_entry *)
1557 bfd_hash_allocate (&info->hash->table,
1558 sizeof (struct bfd_link_hash_entry)));
1561 bfd_set_error (bfd_error_no_memory);
1565 h->type = bfd_link_hash_warning;
1568 h->u.i.warning = string;
1573 w = bfd_hash_allocate (&info->hash->table,
1574 strlen (string) + 1);
1587 /* Generic final link routine. */
1590 _bfd_generic_final_link (abfd, info)
1592 struct bfd_link_info *info;
1596 struct bfd_link_order *p;
1598 struct generic_write_global_symbol_info wginfo;
1600 abfd->outsymbols = (asymbol **) NULL;
1604 /* Build the output symbol table. */
1605 for (sub = info->input_bfds; sub != (bfd *) NULL; sub = sub->link_next)
1606 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc))
1609 /* Accumulate the global symbols. */
1611 wginfo.output_bfd = abfd;
1612 wginfo.psymalloc = &outsymalloc;
1613 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info),
1614 _bfd_generic_link_write_global_symbol,
1617 if (info->relocateable)
1619 /* Allocate space for the output relocs for each section. */
1620 for (o = abfd->sections;
1621 o != (asection *) NULL;
1625 for (p = o->link_order_head;
1626 p != (struct bfd_link_order *) NULL;
1629 if (p->type == bfd_section_reloc_link_order
1630 || p->type == bfd_symbol_reloc_link_order)
1632 else if (p->type == bfd_indirect_link_order)
1634 asection *input_section;
1641 input_section = p->u.indirect.section;
1642 input_bfd = input_section->owner;
1643 relsize = bfd_get_reloc_upper_bound (input_bfd,
1647 relocs = (arelent **) malloc ((size_t) relsize);
1648 if (!relocs && relsize != 0)
1650 bfd_set_error (bfd_error_no_memory);
1653 symbols = _bfd_generic_link_get_symbols (input_bfd);
1654 reloc_count = bfd_canonicalize_reloc (input_bfd,
1658 if (reloc_count < 0)
1660 BFD_ASSERT (reloc_count == input_section->reloc_count);
1661 o->reloc_count += reloc_count;
1665 if (o->reloc_count > 0)
1667 o->orelocation = ((arelent **)
1670 * sizeof (arelent *))));
1671 if (!o->orelocation)
1673 bfd_set_error (bfd_error_no_memory);
1676 o->flags |= SEC_RELOC;
1677 /* Reset the count so that it can be used as an index
1678 when putting in the output relocs. */
1684 /* Handle all the link order information for the sections. */
1685 for (o = abfd->sections;
1686 o != (asection *) NULL;
1689 for (p = o->link_order_head;
1690 p != (struct bfd_link_order *) NULL;
1695 case bfd_section_reloc_link_order:
1696 case bfd_symbol_reloc_link_order:
1697 if (! _bfd_generic_reloc_link_order (abfd, info, o, p))
1701 if (! _bfd_default_link_order (abfd, info, o, p))
1711 /* Add an output symbol to the output BFD. */
1714 generic_add_output_symbol (output_bfd, psymalloc, sym)
1719 if (output_bfd->symcount >= *psymalloc)
1723 if (*psymalloc == 0)
1727 if (output_bfd->outsymbols == (asymbol **) NULL)
1728 newsyms = (asymbol **) malloc (*psymalloc * sizeof (asymbol *));
1730 newsyms = (asymbol **) realloc (output_bfd->outsymbols,
1731 *psymalloc * sizeof (asymbol *));
1732 if (newsyms == (asymbol **) NULL)
1734 bfd_set_error (bfd_error_no_memory);
1737 output_bfd->outsymbols = newsyms;
1740 output_bfd->outsymbols[output_bfd->symcount] = sym;
1741 ++output_bfd->symcount;
1746 /* Handle the symbols for an input BFD. */
1749 _bfd_generic_link_output_symbols (output_bfd, input_bfd, info, psymalloc)
1752 struct bfd_link_info *info;
1758 if (! generic_link_read_symbols (input_bfd))
1761 /* Create a filename symbol if we are supposed to. */
1762 if (info->create_object_symbols_section != (asection *) NULL)
1766 for (sec = input_bfd->sections;
1767 sec != (asection *) NULL;
1770 if (sec->output_section == info->create_object_symbols_section)
1774 newsym = bfd_make_empty_symbol (input_bfd);
1777 newsym->name = input_bfd->filename;
1779 newsym->flags = BSF_LOCAL | BSF_FILE;
1780 newsym->section = sec;
1782 if (! generic_add_output_symbol (output_bfd, psymalloc,
1791 /* Adjust the values of the globally visible symbols, and write out
1793 sym_ptr = _bfd_generic_link_get_symbols (input_bfd);
1794 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd);
1795 for (; sym_ptr < sym_end; sym_ptr++)
1798 struct generic_link_hash_entry *h;
1801 h = (struct generic_link_hash_entry *) NULL;
1803 if ((sym->flags & (BSF_INDIRECT
1808 || bfd_get_section (sym) == &bfd_und_section
1809 || bfd_is_com_section (bfd_get_section (sym))
1810 || bfd_get_section (sym) == &bfd_ind_section)
1812 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info),
1813 bfd_asymbol_name (sym),
1814 false, false, true);
1815 if (h != (struct generic_link_hash_entry *) NULL)
1817 /* Force all references to this symbol to point to
1818 the same area in memory. It is possible that
1819 this routine will be called with a hash table
1820 other than a generic hash table, so we double
1822 if (info->hash->creator == input_bfd->xvec)
1824 if (h->sym != (asymbol *) NULL)
1825 *sym_ptr = sym = h->sym;
1828 switch (h->root.type)
1831 case bfd_link_hash_new:
1833 case bfd_link_hash_undefined:
1834 case bfd_link_hash_weak:
1836 case bfd_link_hash_defined:
1837 sym->value = h->root.u.def.value;
1838 sym->section = h->root.u.def.section;
1839 sym->flags |= BSF_GLOBAL;
1841 case bfd_link_hash_common:
1842 sym->value = h->root.u.c.size;
1843 sym->flags |= BSF_GLOBAL;
1844 if (! bfd_is_com_section (sym->section))
1846 BFD_ASSERT (sym->section == &bfd_und_section);
1847 sym->section = &bfd_com_section;
1849 /* We do not set the section of the symbol to
1850 h->root.u.c.section. That value was saved so
1851 that we would know where to allocate the symbol
1852 if it was defined. In this case the type is
1853 still bfd_link_hash_common, so we did not define
1854 it, so we do not want to use that section. */
1860 /* This switch is straight from the old code in
1861 write_file_locals in ldsym.c. */
1862 if (info->strip == strip_some
1863 && (bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym),
1865 == (struct bfd_hash_entry *) NULL))
1867 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0)
1869 /* If this symbol is marked as occurring now, rather
1870 than at the end, output it now. This is used for
1871 COFF C_EXT FCN symbols. FIXME: There must be a
1873 if (bfd_asymbol_bfd (sym) == input_bfd
1874 && (sym->flags & BSF_NOT_AT_END) != 0)
1879 else if (sym->section == &bfd_ind_section)
1881 else if ((sym->flags & BSF_DEBUGGING) != 0)
1883 if (info->strip == strip_none)
1888 else if (sym->section == &bfd_und_section
1889 || bfd_is_com_section (sym->section))
1891 else if ((sym->flags & BSF_LOCAL) != 0)
1893 if ((sym->flags & BSF_WARNING) != 0)
1897 switch (info->discard)
1904 if (bfd_asymbol_name (sym)[0] == info->lprefix[0]
1905 && (info->lprefix_len == 1
1906 || strncmp (bfd_asymbol_name (sym), info->lprefix,
1907 info->lprefix_len) == 0))
1918 else if ((sym->flags & BSF_CONSTRUCTOR))
1920 if (info->strip != strip_all)
1930 if (! generic_add_output_symbol (output_bfd, psymalloc, sym))
1932 if (h != (struct generic_link_hash_entry *) NULL)
1933 h->root.written = true;
1940 /* Write out a global symbol, if it hasn't already been written out.
1941 This is called for each symbol in the hash table. */
1944 _bfd_generic_link_write_global_symbol (h, data)
1945 struct generic_link_hash_entry *h;
1948 struct generic_write_global_symbol_info *wginfo =
1949 (struct generic_write_global_symbol_info *) data;
1952 if (h->root.written)
1955 h->root.written = true;
1957 if (wginfo->info->strip == strip_all
1958 || (wginfo->info->strip == strip_some
1959 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string,
1960 false, false) == NULL))
1963 if (h->sym != (asymbol *) NULL)
1966 BFD_ASSERT (strcmp (bfd_asymbol_name (sym), h->root.root.string) == 0);
1970 sym = bfd_make_empty_symbol (wginfo->output_bfd);
1973 sym->name = h->root.root.string;
1977 switch (h->root.type)
1980 case bfd_link_hash_new:
1982 case bfd_link_hash_undefined:
1983 sym->section = &bfd_und_section;
1986 case bfd_link_hash_weak:
1987 sym->section = &bfd_und_section;
1989 sym->flags |= BSF_WEAK;
1991 case bfd_link_hash_defined:
1992 sym->section = h->root.u.def.section;
1993 sym->value = h->root.u.def.value;
1995 case bfd_link_hash_common:
1996 sym->value = h->root.u.c.size;
1997 if (! bfd_is_com_section (sym->section))
1999 BFD_ASSERT (sym->section == &bfd_und_section);
2000 sym->section = &bfd_com_section;
2002 /* Do not set the section; see _bfd_generic_link_output_symbols. */
2004 case bfd_link_hash_indirect:
2005 case bfd_link_hash_warning:
2006 /* FIXME: What should we do here? */
2010 sym->flags |= BSF_GLOBAL;
2012 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc,
2015 /* FIXME: No way to return failure. */
2022 /* Create a relocation. */
2025 _bfd_generic_reloc_link_order (abfd, info, sec, link_order)
2027 struct bfd_link_info *info;
2029 struct bfd_link_order *link_order;
2033 if (! info->relocateable)
2035 if (sec->orelocation == (arelent **) NULL)
2038 r = (arelent *) bfd_alloc (abfd, sizeof (arelent));
2039 if (r == (arelent *) NULL)
2041 bfd_set_error (bfd_error_no_memory);
2045 r->address = link_order->offset;
2046 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc);
2047 if (r->howto == (const reloc_howto_type *) NULL)
2049 bfd_set_error (bfd_error_bad_value);
2053 /* Get the symbol to use for the relocation. */
2054 if (link_order->type == bfd_section_reloc_link_order)
2055 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr;
2058 struct generic_link_hash_entry *h;
2060 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info),
2061 link_order->u.reloc.p->u.name,
2062 false, false, true);
2063 if (h == (struct generic_link_hash_entry *) NULL
2064 || ! h->root.written)
2066 if (! ((*info->callbacks->unattached_reloc)
2067 (info, link_order->u.reloc.p->u.name,
2068 (bfd *) NULL, (asection *) NULL, (bfd_vma) 0)))
2070 bfd_set_error (bfd_error_bad_value);
2073 r->sym_ptr_ptr = &h->sym;
2076 /* If this is an inplace reloc, write the addend to the object file.
2077 Otherwise, store it in the reloc addend. */
2078 if (! r->howto->partial_inplace)
2079 r->addend = link_order->u.reloc.p->addend;
2083 bfd_reloc_status_type rstat;
2087 size = bfd_get_reloc_size (r->howto);
2088 buf = (bfd_byte *) bfd_zmalloc (size);
2089 if (buf == (bfd_byte *) NULL)
2091 bfd_set_error (bfd_error_no_memory);
2094 rstat = _bfd_relocate_contents (r->howto, abfd,
2095 link_order->u.reloc.p->addend, buf);
2101 case bfd_reloc_outofrange:
2103 case bfd_reloc_overflow:
2104 if (! ((*info->callbacks->reloc_overflow)
2106 (link_order->type == bfd_section_reloc_link_order
2107 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section)
2108 : link_order->u.reloc.p->u.name),
2109 r->howto->name, link_order->u.reloc.p->addend,
2110 (bfd *) NULL, (asection *) NULL, (bfd_vma) 0)))
2117 ok = bfd_set_section_contents (abfd, sec, (PTR) buf,
2118 (file_ptr) link_order->offset, size);
2126 sec->orelocation[sec->reloc_count] = r;
2132 /* Allocate a new link_order for a section. */
2134 struct bfd_link_order *
2135 bfd_new_link_order (abfd, section)
2139 struct bfd_link_order *new;
2141 new = ((struct bfd_link_order *)
2142 bfd_alloc_by_size_t (abfd, sizeof (struct bfd_link_order)));
2145 bfd_set_error (bfd_error_no_memory);
2149 new->type = bfd_undefined_link_order;
2152 new->next = (struct bfd_link_order *) NULL;
2154 if (section->link_order_tail != (struct bfd_link_order *) NULL)
2155 section->link_order_tail->next = new;
2157 section->link_order_head = new;
2158 section->link_order_tail = new;
2163 /* Default link order processing routine. Note that we can not handle
2164 the reloc_link_order types here, since they depend upon the details
2165 of how the particular backends generates relocs. */
2168 _bfd_default_link_order (abfd, info, sec, link_order)
2170 struct bfd_link_info *info;
2172 struct bfd_link_order *link_order;
2174 switch (link_order->type)
2176 case bfd_undefined_link_order:
2177 case bfd_section_reloc_link_order:
2178 case bfd_symbol_reloc_link_order:
2181 case bfd_indirect_link_order:
2182 return default_indirect_link_order (abfd, info, sec, link_order);
2183 case bfd_fill_link_order:
2184 return default_fill_link_order (abfd, info, sec, link_order);
2185 case bfd_data_link_order:
2186 return bfd_set_section_contents (abfd, sec,
2187 (PTR) link_order->u.data.contents,
2188 (file_ptr) link_order->offset,
2193 /* Default routine to handle a bfd_fill_link_order. */
2197 default_fill_link_order (abfd, info, sec, link_order)
2199 struct bfd_link_info *info;
2201 struct bfd_link_order *link_order;
2209 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0);
2211 size = (size_t) link_order->size;
2212 space = (char *) malloc (size);
2213 if (space == NULL && size != 0)
2215 bfd_set_error (bfd_error_no_memory);
2219 fill = link_order->u.fill.value;
2220 for (i = 0; i < size; i += 2)
2221 space[i] = fill >> 8;
2222 for (i = 1; i < size; i += 2)
2224 result = bfd_set_section_contents (abfd, sec, space,
2225 (file_ptr) link_order->offset,
2231 /* Default routine to handle a bfd_indirect_link_order. */
2234 default_indirect_link_order (output_bfd, info, output_section, link_order)
2236 struct bfd_link_info *info;
2237 asection *output_section;
2238 struct bfd_link_order *link_order;
2240 asection *input_section;
2242 bfd_byte *contents = NULL;
2243 bfd_byte *new_contents;
2245 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0);
2247 if (link_order->size == 0)
2250 input_section = link_order->u.indirect.section;
2251 input_bfd = input_section->owner;
2253 BFD_ASSERT (input_section->output_section == output_section);
2254 BFD_ASSERT (input_section->output_offset == link_order->offset);
2255 BFD_ASSERT (input_section->_cooked_size == link_order->size);
2257 if (info->relocateable
2258 && input_section->reloc_count > 0
2259 && output_section->orelocation == (arelent **) NULL)
2261 /* Space has not been allocated for the output relocations.
2262 This can happen when we are called by a specific backend
2263 because somebody is attempting to link together different
2264 types of object files. Handling this case correctly is
2265 difficult, and sometimes impossible. */
2269 /* Get the canonical symbols. The generic linker will always have
2270 retrieved them by this point, but we may be being called by a
2271 specific linker when linking different types of object files
2273 if (! generic_link_read_symbols (input_bfd))
2276 /* Get and relocate the section contents. */
2277 contents = (bfd_byte *) malloc (bfd_section_size (input_bfd, input_section));
2278 if (contents == NULL && bfd_section_size (input_bfd, input_section) != 0)
2280 bfd_set_error (bfd_error_no_memory);
2283 new_contents = (bfd_get_relocated_section_contents
2284 (output_bfd, info, link_order, contents, info->relocateable,
2285 _bfd_generic_link_get_symbols (input_bfd)));
2289 /* Output the section contents. */
2290 if (! bfd_set_section_contents (output_bfd, output_section,
2292 link_order->offset, link_order->size))
2295 if (contents != NULL)
2300 if (contents != NULL)
2305 /* A little routine to count the number of relocs in a link_order
2309 _bfd_count_link_order_relocs (link_order)
2310 struct bfd_link_order *link_order;
2312 register unsigned int c;
2313 register struct bfd_link_order *l;
2316 for (l = link_order; l != (struct bfd_link_order *) NULL; l = l->next)
2318 if (l->type == bfd_section_reloc_link_order
2319 || l->type == bfd_symbol_reloc_link_order)