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.
319 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link
321 Relocating the section contents
323 The <<_bfd_final_link>> function should look through the
324 <<link_order>> structures attached to each section of the
325 output file. Each <<link_order>> structure should either be
326 handled specially, or it should be passed to the function
327 <<_bfd_default_link_order>> which will do the right thing
328 (<<_bfd_default_link_order>> is defined in <<linker.c>>).
330 For efficiency, a <<link_order>> of type
331 <<bfd_indirect_link_order>> whose associated section belongs
332 to a BFD of the same format as the output BFD must be handled
333 specially. This type of <<link_order>> describes part of an
334 output section in terms of a section belonging to one of the
335 input files. The <<_bfd_final_link>> function should read the
336 contents of the section and any associated relocs, apply the
337 relocs to the section contents, and write out the modified
338 section contents. If performing a relocateable link, the
339 relocs themselves must also be modified and written out.
341 @findex _bfd_relocate_contents
342 @findex _bfd_final_link_relocate
343 The functions <<_bfd_relocate_contents>> and
344 <<_bfd_final_link_relocate>> provide some general support for
345 performing the actual relocations, notably overflow checking.
346 Their arguments include information about the symbol the
347 relocation is against and a <<reloc_howto_type>> argument
348 which describes the relocation to perform. These functions
349 are defined in <<reloc.c>>.
351 The a.out function which handles reading, relocating, and
352 writing section contents is <<aout_link_input_section>>. The
353 actual relocation is done in <<aout_link_input_section_std>>
354 and <<aout_link_input_section_ext>>.
357 Writing the symbol table, , Relocating the section contents, Performing the Final Link
359 Writing the symbol table
361 The <<_bfd_final_link>> function must gather all the symbols
362 in the input files and write them out. It must also write out
363 all the symbols in the global hash table. This must be
364 controlled by the <<strip>> and <<discard>> fields of the
365 <<bfd_link_info>> structure.
367 The local symbols of the input files will not have been
368 entered into the linker hash table. The <<_bfd_final_link>>
369 routine must consider each input file and include the symbols
370 in the output file. It may be convenient to do this when
371 looking through the <<link_order>> structures, or it may be
372 done by stepping through the <<input_bfds>> list.
374 The <<_bfd_final_link>> routine must also traverse the global
375 hash table to gather all the externally visible symbols. It
376 is possible that most of the externally visible symbols may be
377 written out when considering the symbols of each input file,
378 but it is still necessary to traverse the hash table since the
379 linker script may have defined some symbols that are not in
380 any of the input files. The <<written>> field in the
381 <<bfd_link_hash_entry>> structure may be used to determine
382 which entries in the hash table have not already been written
385 The <<strip>> field of the <<bfd_link_info>> structure
386 controls which symbols are written out. The possible values
387 are listed in <<bfdlink.h>>. If the value is <<strip_some>>,
388 then the <<keep_hash>> field of the <<bfd_link_info>>
389 structure is a hash table of symbols to keep; each symbol
390 should be looked up in this hash table, and only symbols which
391 are present should be included in the output file.
393 If the <<strip>> field of the <<bfd_link_info>> structure
394 permits local symbols to be written out, the <<discard>> field
395 is used to further controls which local symbols are included
396 in the output file. If the value is <<discard_l>>, then all
397 local symbols which begin with a certain prefix are discarded;
398 this prefix is described by the <<lprefix>> and
399 <<lprefix_len>> fields of the <<bfd_link_info>> structure.
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 struct bfd_hash_entry
*generic_link_hash_newfunc
410 PARAMS ((struct bfd_hash_entry
*, struct bfd_hash_table
*,
412 static boolean generic_link_add_object_symbols
413 PARAMS ((bfd
*, struct bfd_link_info
*));
414 static boolean generic_link_check_archive_element
415 PARAMS ((bfd
*, struct bfd_link_info
*, boolean
*pneeded
));
416 static boolean generic_link_add_symbol_list
417 PARAMS ((bfd
*, struct bfd_link_info
*, bfd_size_type count
, asymbol
**));
418 static boolean generic_add_output_symbol
419 PARAMS ((bfd
*, size_t *psymalloc
, asymbol
*));
420 static boolean default_fill_link_order
421 PARAMS ((bfd
*, struct bfd_link_info
*, asection
*,
422 struct bfd_link_order
*));
423 static boolean default_indirect_link_order
424 PARAMS ((bfd
*, struct bfd_link_info
*, asection
*,
425 struct bfd_link_order
*));
427 /* The link hash table structure is defined in bfdlink.h. It provides
428 a base hash table which the backend specific hash tables are built
431 /* Routine to create an entry in the link hash table. */
433 struct bfd_hash_entry
*
434 _bfd_link_hash_newfunc (entry
, table
, string
)
435 struct bfd_hash_entry
*entry
;
436 struct bfd_hash_table
*table
;
439 struct bfd_link_hash_entry
*ret
= (struct bfd_link_hash_entry
*) entry
;
441 /* Allocate the structure if it has not already been allocated by a
443 if (ret
== (struct bfd_link_hash_entry
*) NULL
)
444 ret
= ((struct bfd_link_hash_entry
*)
445 bfd_hash_allocate (table
, sizeof (struct bfd_link_hash_entry
)));
446 if (ret
== (struct bfd_link_hash_entry
*) NULL
)
448 bfd_error
= no_memory
;
452 /* Call the allocation method of the superclass. */
453 ret
= ((struct bfd_link_hash_entry
*)
454 bfd_hash_newfunc ((struct bfd_hash_entry
*) ret
, table
, string
));
458 /* Initialize the local fields. */
459 ret
->type
= bfd_link_hash_new
;
460 ret
->written
= false;
464 return (struct bfd_hash_entry
*) ret
;
467 /* Initialize a link hash table. The BFD argument is the one
468 responsible for creating this table. */
471 _bfd_link_hash_table_init (table
, abfd
, newfunc
)
472 struct bfd_link_hash_table
*table
;
474 struct bfd_hash_entry
*(*newfunc
) PARAMS ((struct bfd_hash_entry
*,
475 struct bfd_hash_table
*,
478 table
->creator
= abfd
->xvec
;
479 table
->undefs
= NULL
;
480 table
->undefs_tail
= NULL
;
481 return bfd_hash_table_init (&table
->table
, newfunc
);
484 /* Look up a symbol in a link hash table. If follow is true, we
485 follow bfd_link_hash_indirect and bfd_link_hash_warning links to
488 struct bfd_link_hash_entry
*
489 bfd_link_hash_lookup (table
, string
, create
, copy
, follow
)
490 struct bfd_link_hash_table
*table
;
496 struct bfd_link_hash_entry
*ret
;
498 ret
= ((struct bfd_link_hash_entry
*)
499 bfd_hash_lookup (&table
->table
, string
, create
, copy
));
501 if (follow
&& ret
!= (struct bfd_link_hash_entry
*) NULL
)
503 while (ret
->type
== bfd_link_hash_indirect
504 || ret
->type
== bfd_link_hash_warning
)
511 /* Traverse a generic link hash table. The only reason this is not a
512 macro is to do better type checking. This code presumes that an
513 argument passed as a struct bfd_hash_entry * may be caught as a
514 struct bfd_link_hash_entry * with no explicit cast required on the
518 bfd_link_hash_traverse (table
, func
, info
)
519 struct bfd_link_hash_table
*table
;
520 boolean (*func
) PARAMS ((struct bfd_link_hash_entry
*, PTR
));
523 bfd_hash_traverse (&table
->table
,
524 ((boolean (*) PARAMS ((struct bfd_hash_entry
*, PTR
)))
529 /* Add a symbol to the linker hash table undefs list. */
532 bfd_link_add_undef (table
, h
)
533 struct bfd_link_hash_table
*table
;
534 struct bfd_link_hash_entry
*h
;
536 BFD_ASSERT (h
->next
== NULL
);
537 if (table
->undefs_tail
!= (struct bfd_link_hash_entry
*) NULL
)
538 table
->undefs_tail
->next
= h
;
539 if (table
->undefs
== (struct bfd_link_hash_entry
*) NULL
)
541 table
->undefs_tail
= h
;
544 /* Routine to create an entry in an generic link hash table. */
546 static struct bfd_hash_entry
*
547 generic_link_hash_newfunc (entry
, table
, string
)
548 struct bfd_hash_entry
*entry
;
549 struct bfd_hash_table
*table
;
552 struct generic_link_hash_entry
*ret
=
553 (struct generic_link_hash_entry
*) entry
;
555 /* Allocate the structure if it has not already been allocated by a
557 if (ret
== (struct generic_link_hash_entry
*) NULL
)
558 ret
= ((struct generic_link_hash_entry
*)
559 bfd_hash_allocate (table
, sizeof (struct generic_link_hash_entry
)));
560 if (ret
== (struct generic_link_hash_entry
*) NULL
)
562 bfd_error
= no_memory
;
566 /* Call the allocation method of the superclass. */
567 ret
= ((struct generic_link_hash_entry
*)
568 _bfd_link_hash_newfunc ((struct bfd_hash_entry
*) ret
,
573 /* Set local fields. */
577 return (struct bfd_hash_entry
*) ret
;
580 /* Create an generic link hash table. */
582 struct bfd_link_hash_table
*
583 _bfd_generic_link_hash_table_create (abfd
)
586 struct generic_link_hash_table
*ret
;
588 ret
= ((struct generic_link_hash_table
*)
589 malloc (sizeof (struct generic_link_hash_table
)));
592 bfd_error
= no_memory
;
593 return (struct bfd_link_hash_table
*) NULL
;
595 if (! _bfd_link_hash_table_init (&ret
->root
, abfd
,
596 generic_link_hash_newfunc
))
599 return (struct bfd_link_hash_table
*) NULL
;
604 /* Generic function to add symbols from an object file to the global
608 _bfd_generic_link_add_symbols (abfd
, info
)
610 struct bfd_link_info
*info
;
614 switch (bfd_get_format (abfd
))
617 ret
= generic_link_add_object_symbols (abfd
, info
);
620 ret
= _bfd_generic_link_add_archive_symbols
621 (abfd
, info
, generic_link_check_archive_element
);
624 bfd_error
= wrong_format
;
628 /* If we might be using the C based alloca function, make sure we
629 have dumped the symbol tables we just allocated. */
639 /* Add symbols from an object file to the global hash table. */
642 generic_link_add_object_symbols (abfd
, info
)
644 struct bfd_link_info
*info
;
648 bfd_size_type symbol_count
;
650 symsize
= get_symtab_upper_bound (abfd
);
651 symbols
= (asymbol
**) alloca (symsize
);
652 symbol_count
= bfd_canonicalize_symtab (abfd
, symbols
);
654 return generic_link_add_symbol_list (abfd
, info
, symbol_count
, symbols
);
657 /* We build a hash table of all symbols defined in an archive. */
659 /* An archive symbol may be defined by multiple archive elements.
660 This linked list is used to hold the elements. */
664 struct archive_list
*next
;
668 /* An entry in an archive hash table. */
670 struct archive_hash_entry
672 struct bfd_hash_entry root
;
673 /* Where the symbol is defined. */
674 struct archive_list
*defs
;
677 /* An archive hash table itself. */
679 struct archive_hash_table
681 struct bfd_hash_table table
;
684 static struct bfd_hash_entry
*archive_hash_newfunc
685 PARAMS ((struct bfd_hash_entry
*, struct bfd_hash_table
*, const char *));
686 static boolean archive_hash_table_init
687 PARAMS ((struct archive_hash_table
*,
688 struct bfd_hash_entry
*(*) (struct bfd_hash_entry
*,
689 struct bfd_hash_table
*,
692 /* Create a new entry for an archive hash table. */
694 static struct bfd_hash_entry
*
695 archive_hash_newfunc (entry
, table
, string
)
696 struct bfd_hash_entry
*entry
;
697 struct bfd_hash_table
*table
;
700 struct archive_hash_entry
*ret
= (struct archive_hash_entry
*) entry
;
702 /* Allocate the structure if it has not already been allocated by a
704 if (ret
== (struct archive_hash_entry
*) NULL
)
705 ret
= ((struct archive_hash_entry
*)
706 bfd_hash_allocate (table
, sizeof (struct archive_hash_entry
)));
707 if (ret
== (struct archive_hash_entry
*) NULL
)
709 bfd_error
= no_memory
;
713 /* Call the allocation method of the superclass. */
714 ret
= ((struct archive_hash_entry
*)
715 bfd_hash_newfunc ((struct bfd_hash_entry
*) ret
, table
, string
));
719 /* Initialize the local fields. */
720 ret
->defs
= (struct archive_list
*) NULL
;
723 return (struct bfd_hash_entry
*) ret
;
726 /* Initialize an archive hash table. */
729 archive_hash_table_init (table
, newfunc
)
730 struct archive_hash_table
*table
;
731 struct bfd_hash_entry
*(*newfunc
) PARAMS ((struct bfd_hash_entry
*,
732 struct bfd_hash_table
*,
735 return bfd_hash_table_init (&table
->table
, newfunc
);
738 /* Look up an entry in an archive hash table. */
740 #define archive_hash_lookup(t, string, create, copy) \
741 ((struct archive_hash_entry *) \
742 bfd_hash_lookup (&(t)->table, (string), (create), (copy)))
744 /* Free an archive hash table. */
746 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table)
748 /* Generic function to add symbols from an archive file to the global
749 hash file. This function presumes that the archive symbol table
750 has already been read in (this is normally done by the
751 bfd_check_format entry point). It looks through the undefined and
752 common symbols and searches the archive symbol table for them. If
753 it finds an entry, it includes the associated object file in the
756 The old linker looked through the archive symbol table for
757 undefined symbols. We do it the other way around, looking through
758 undefined symbols for symbols defined in the archive. The
759 advantage of the newer scheme is that we only have to look through
760 the list of undefined symbols once, whereas the old method had to
761 re-search the symbol table each time a new object file was added.
763 The CHECKFN argument is used to see if an object file should be
764 included. CHECKFN should set *PNEEDED to true if the object file
765 should be included, and must also call the bfd_link_info
766 add_archive_element callback function and handle adding the symbols
767 to the global hash table. CHECKFN should only return false if some
768 sort of error occurs.
770 For some formats, such as a.out, it is possible to look through an
771 object file but not actually include it in the link. The
772 archive_pass field in a BFD is used to avoid checking the symbols
773 of an object files too many times. When an object is included in
774 the link, archive_pass is set to -1. If an object is scanned but
775 not included, archive_pass is set to the pass number. The pass
776 number is incremented each time a new object file is included. The
777 pass number is used because when a new object file is included it
778 may create new undefined symbols which cause a previously examined
779 object file to be included. */
782 _bfd_generic_link_add_archive_symbols (abfd
, info
, checkfn
)
784 struct bfd_link_info
*info
;
785 boolean (*checkfn
) PARAMS ((bfd
*, struct bfd_link_info
*,
790 register carsym
*arsym
;
792 struct archive_hash_table arsym_hash
;
794 struct bfd_link_hash_entry
**pundef
;
796 if (! bfd_has_map (abfd
))
798 bfd_error
= no_symbols
;
802 arsyms
= bfd_ardata (abfd
)->symdefs
;
803 arsym_end
= arsyms
+ bfd_ardata (abfd
)->symdef_count
;
805 /* In order to quickly determine whether an symbol is defined in
806 this archive, we build a hash table of the symbols. */
807 if (! archive_hash_table_init (&arsym_hash
, archive_hash_newfunc
))
809 for (arsym
= arsyms
, indx
= 0; arsym
< arsym_end
; arsym
++, indx
++)
811 struct archive_hash_entry
*arh
;
812 struct archive_list
*l
;
814 arh
= archive_hash_lookup (&arsym_hash
, arsym
->name
, true, false);
815 if (arh
== (struct archive_hash_entry
*) NULL
)
817 l
= (struct archive_list
*) alloca (sizeof (struct archive_list
));
825 /* New undefined symbols are added to the end of the list, so we
826 only need to look through it once. */
827 pundef
= &info
->hash
->undefs
;
828 while (*pundef
!= (struct bfd_link_hash_entry
*) NULL
)
830 struct bfd_link_hash_entry
*h
;
831 struct archive_hash_entry
*arh
;
832 struct archive_list
*l
;
836 /* When a symbol is defined, it is not necessarily removed from
838 if (h
->type
!= bfd_link_hash_undefined
839 && h
->type
!= bfd_link_hash_common
)
841 /* Remove this entry from the list, for general cleanliness
842 and because we are going to look through the list again
843 if we search any more libraries. We can't remove the
844 entry if it is the tail, because that would lose any
845 entries we add to the list later on. */
846 if (*pundef
!= info
->hash
->undefs_tail
)
847 *pundef
= (*pundef
)->next
;
849 pundef
= &(*pundef
)->next
;
853 /* Look for this symbol in the archive symbol map. */
854 arh
= archive_hash_lookup (&arsym_hash
, h
->root
.string
, false, false);
855 if (arh
== (struct archive_hash_entry
*) NULL
)
857 pundef
= &(*pundef
)->next
;
861 /* Look at all the objects which define this symbol. */
862 for (l
= arh
->defs
; l
!= (struct archive_list
*) NULL
; l
= l
->next
)
867 /* If the symbol has gotten defined along the way, quit. */
868 if (h
->type
!= bfd_link_hash_undefined
869 && h
->type
!= bfd_link_hash_common
)
872 element
= bfd_get_elt_at_index (abfd
, l
->indx
);
873 if (element
== (bfd
*) NULL
)
876 /* If we've already included this element, or if we've
877 already checked it on this pass, continue. */
878 if (element
->archive_pass
== -1
879 || element
->archive_pass
== pass
)
882 /* If we can't figure this element out, just ignore it. */
883 if (! bfd_check_format (element
, bfd_object
))
885 element
->archive_pass
= -1;
889 /* CHECKFN will see if this element should be included, and
890 go ahead and include it if appropriate. */
891 if (! (*checkfn
) (element
, info
, &needed
))
895 element
->archive_pass
= pass
;
898 element
->archive_pass
= -1;
900 /* Increment the pass count to show that we may need to
901 recheck object files which were already checked. */
906 pundef
= &(*pundef
)->next
;
909 archive_hash_table_free (&arsym_hash
);
914 /* See if we should include an archive element. */
917 generic_link_check_archive_element (abfd
, info
, pneeded
)
919 struct bfd_link_info
*info
;
924 bfd_size_type symbol_count
;
925 asymbol
**pp
, **ppend
;
929 symsize
= get_symtab_upper_bound (abfd
);
930 symbols
= (asymbol
**) alloca (symsize
);
931 symbol_count
= bfd_canonicalize_symtab (abfd
, symbols
);
934 ppend
= symbols
+ symbol_count
;
935 for (; pp
< ppend
; pp
++)
938 struct bfd_link_hash_entry
*h
;
942 /* We are only interested in globally visible symbols. */
943 if (! bfd_is_com_section (p
->section
)
944 && (p
->flags
& (BSF_GLOBAL
| BSF_INDIRECT
| BSF_WEAK
)) == 0)
947 /* We are only interested if we know something about this
948 symbol, and it is undefined or common. An undefined weak
949 symbol (type bfd_link_hash_weak) is not considered to be a
950 reference when pulling files out of an archive. See the SVR4
952 h
= bfd_link_hash_lookup (info
->hash
, bfd_asymbol_name (p
), false,
954 if (h
== (struct bfd_link_hash_entry
*) NULL
955 || (h
->type
!= bfd_link_hash_undefined
956 && h
->type
!= bfd_link_hash_common
))
959 /* P is a symbol we are looking for. */
961 if (! bfd_is_com_section (p
->section
))
963 /* This object file defines this symbol, so pull it in. */
964 if (! (*info
->callbacks
->add_archive_element
) (info
, abfd
,
965 bfd_asymbol_name (p
)))
967 if (! generic_link_add_symbol_list (abfd
, info
, symbol_count
,
974 /* P is a common symbol. */
976 if (h
->type
== bfd_link_hash_undefined
)
980 symbfd
= h
->u
.undef
.abfd
;
981 if (symbfd
== (bfd
*) NULL
)
983 /* This symbol was created as undefined from outside
984 BFD. We assume that we should link in the object
985 file. This is for the -u option in the linker. */
986 if (! (*info
->callbacks
->add_archive_element
)
987 (info
, abfd
, bfd_asymbol_name (p
)))
993 /* Turn the symbol into a common symbol but do not link in
994 the object file. This is how a.out works. Object
995 formats that require different semantics must implement
996 this function differently. This symbol is already on the
997 undefs list. We add the section to a common section
998 attached to symbfd to ensure that it is in a BFD which
999 will be linked in. */
1000 h
->type
= bfd_link_hash_common
;
1001 h
->u
.c
.size
= bfd_asymbol_value (p
);
1002 if (p
->section
== &bfd_com_section
)
1003 h
->u
.c
.section
= bfd_make_section_old_way (symbfd
, "COMMON");
1005 h
->u
.c
.section
= bfd_make_section_old_way (symbfd
,
1007 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1011 /* Adjust the size of the common symbol if necessary. This
1012 is how a.out works. Object formats that require
1013 different semantics must implement this function
1015 if (bfd_asymbol_value (p
) > h
->u
.c
.size
)
1016 h
->u
.c
.size
= bfd_asymbol_value (p
);
1020 /* This archive element is not needed. */
1024 /* Add the symbol from an object file to the global hash table. */
1027 generic_link_add_symbol_list (abfd
, info
, symbol_count
, symbols
)
1029 struct bfd_link_info
*info
;
1030 bfd_size_type symbol_count
;
1033 asymbol
**pp
, **ppend
;
1036 ppend
= symbols
+ symbol_count
;
1037 for (; pp
< ppend
; pp
++)
1043 if ((p
->flags
& (BSF_INDIRECT
1048 || bfd_get_section (p
) == &bfd_und_section
1049 || bfd_is_com_section (bfd_get_section (p
))
1050 || bfd_get_section (p
) == &bfd_ind_section
)
1054 struct generic_link_hash_entry
*h
;
1056 name
= bfd_asymbol_name (p
);
1057 if ((p
->flags
& BSF_INDIRECT
) != 0
1058 || p
->section
== &bfd_ind_section
)
1059 string
= bfd_asymbol_name ((asymbol
*) p
->value
);
1060 else if ((p
->flags
& BSF_WARNING
) != 0)
1062 /* The name of P is actually the warning string, and the
1063 value is actually a pointer to the symbol to warn
1066 name
= bfd_asymbol_name ((asymbol
*) p
->value
);
1071 /* We pass the constructor argument as false, for
1072 compatibility. As backends are converted they can
1073 arrange to pass the right value (the right value is the
1074 size of a function pointer if gcc uses collect2 for the
1075 object file format, zero if it does not).
1076 FIXME: We pass the bitsize as 32, which is just plain
1077 wrong, but actually doesn't matter very much. */
1078 if (! (_bfd_generic_link_add_one_symbol
1079 (info
, abfd
, name
, p
->flags
, bfd_get_section (p
),
1080 p
->value
, string
, false, 0, 32,
1081 (struct bfd_link_hash_entry
**) &h
)))
1084 /* Save the BFD symbol so that we don't lose any backend
1085 specific information that may be attached to it. We only
1086 want this one if it gives more information than the
1087 existing one; we don't want to replace a defined symbol
1088 with an undefined one. This routine may be called with a
1089 hash table other than the generic hash table, so we only
1090 do this if we are certain that the hash table is a
1092 if (info
->hash
->creator
== abfd
->xvec
)
1094 if (h
->sym
== (asymbol
*) NULL
1095 || (bfd_get_section (p
) != &bfd_und_section
1096 && (! bfd_is_com_section (bfd_get_section (p
))
1097 || (bfd_get_section (h
->sym
) == &bfd_und_section
))))
1100 /* BSF_OLD_COMMON is a hack to support COFF reloc
1101 reading, and it should go away when the COFF
1102 linker is switched to the new version. */
1103 if (bfd_is_com_section (bfd_get_section (p
)))
1104 p
->flags
|= BSF_OLD_COMMON
;
1113 /* We use a state table to deal with adding symbols from an object
1114 file. The first index into the state table describes the symbol
1115 from the object file. The second index into the state table is the
1116 type of the symbol in the hash table. */
1118 /* The symbol from the object file is turned into one of these row
1123 UNDEF_ROW
, /* Undefined. */
1124 UNDEFW_ROW
, /* Weak undefined. */
1125 DEF_ROW
, /* Defined. */
1126 DEFW_ROW
, /* Weak defined. */
1127 COMMON_ROW
, /* Common. */
1128 INDR_ROW
, /* Indirect. */
1129 WARN_ROW
, /* Warning. */
1130 SET_ROW
/* Member of set. */
1133 /* The actions to take in the state table. */
1138 UND
, /* Mark symbol undefined. */
1139 WEAK
, /* Mark symbol weak undefined. */
1140 DEF
, /* Mark symbol defined. */
1141 COM
, /* Mark symbol common. */
1142 CREF
, /* Possibly warn about common reference to defined symbol. */
1143 CDEF
, /* Define existing common symbol. */
1144 NOACT
, /* No action. */
1145 BIG
, /* Mark symbol common using largest size. */
1146 MDEF
, /* Multiple definition error. */
1147 IND
, /* Make indirect symbol. */
1148 SET
, /* Add value to set. */
1149 MWARN
, /* Make warning symbol. */
1150 WARN
, /* Issue warning. */
1151 CYCLE
, /* Repeat with symbol pointed to. */
1152 WARNC
/* Issue warning and then CYCLE. */
1155 /* The state table itself. The first index is a link_row and the
1156 second index is a bfd_link_hash_type. */
1158 static const enum link_action link_action
[8][7] =
1160 /* current\prev new undef weak def com indr warn */
1161 /* UNDEF_ROW */ {UND
, NOACT
, NOACT
, NOACT
, NOACT
, CYCLE
, WARNC
},
1162 /* UNDEFW_ROW */ {WEAK
, WEAK
, NOACT
, NOACT
, NOACT
, CYCLE
, WARNC
},
1163 /* DEF_ROW */ {DEF
, DEF
, DEF
, MDEF
, CDEF
, CYCLE
, CYCLE
},
1164 /* DEFW_ROW */ {DEF
, DEF
, DEF
, NOACT
, NOACT
, CYCLE
, CYCLE
},
1165 /* COMMON_ROW */ {COM
, COM
, COM
, CREF
, BIG
, CYCLE
, WARNC
},
1166 /* INDR_ROW */ {IND
, IND
, IND
, MDEF
, MDEF
, MDEF
, WARNC
},
1167 /* WARN_ROW */ {MWARN
, WARN
, WARN
, MWARN
, MWARN
, MWARN
, NOACT
},
1168 /* SET_ROW */ {SET
, SET
, SET
, SET
, SET
, CYCLE
, WARNC
}
1171 /* Add a symbol to the global hash table.
1172 ABFD is the BFD the symbol comes from.
1173 NAME is the name of the symbol.
1174 FLAGS is the BSF_* bits associated with the symbol.
1175 SECTION is the section in which the symbol is defined; this may be
1176 bfd_und_section or bfd_com_section.
1177 VALUE is the value of the symbol, relative to the section.
1178 STRING is used for either an indirect symbol, in which case it is
1179 the name of the symbol to indirect to, or a warning symbol, in
1180 which case it is the warning string.
1181 COPY is true if NAME or STRING must be copied into locally
1182 allocated memory if they need to be saved.
1183 CONSTRUCTOR is true if we should automatically collect gcc
1184 constructor or destructor names.
1185 BITSIZE is the number of bits in constructor or set entries.
1186 HASHP, if not NULL, is a place to store the created hash table
1190 _bfd_generic_link_add_one_symbol (info
, abfd
, name
, flags
, section
, value
,
1191 string
, copy
, constructor
, bitsize
, hashp
)
1192 struct bfd_link_info
*info
;
1200 boolean constructor
;
1201 unsigned int bitsize
;
1202 struct bfd_link_hash_entry
**hashp
;
1205 struct bfd_link_hash_entry
*h
;
1208 if (section
== &bfd_ind_section
1209 || (flags
& BSF_INDIRECT
) != 0)
1211 else if ((flags
& BSF_WARNING
) != 0)
1213 else if ((flags
& BSF_CONSTRUCTOR
) != 0)
1215 else if (section
== &bfd_und_section
)
1217 if ((flags
& BSF_WEAK
) != 0)
1222 else if ((flags
& BSF_WEAK
) != 0)
1224 else if (bfd_is_com_section (section
))
1229 h
= bfd_link_hash_lookup (info
->hash
, name
, true, copy
, false);
1230 if (h
== (struct bfd_link_hash_entry
*) NULL
)
1232 if (hashp
!= (struct bfd_link_hash_entry
**) NULL
)
1237 if (info
->notice_hash
!= (struct bfd_hash_table
*) NULL
1238 && (bfd_hash_lookup (info
->notice_hash
, name
, false, false)
1239 != (struct bfd_hash_entry
*) NULL
))
1241 if (! (*info
->callbacks
->notice
) (info
, name
, abfd
, section
, value
))
1245 if (hashp
!= (struct bfd_link_hash_entry
**) NULL
)
1250 enum link_action action
;
1253 action
= link_action
[(int) row
][(int) h
->type
];
1259 h
->type
= bfd_link_hash_undefined
;
1260 h
->u
.undef
.abfd
= abfd
;
1261 bfd_link_add_undef (info
->hash
, h
);
1264 h
->type
= bfd_link_hash_weak
;
1265 h
->u
.undef
.abfd
= abfd
;
1268 BFD_ASSERT (h
->type
== bfd_link_hash_common
);
1269 if (! ((*info
->callbacks
->multiple_common
)
1271 h
->u
.c
.section
->owner
, bfd_link_hash_common
, h
->u
.c
.size
,
1272 abfd
, bfd_link_hash_defined
, (bfd_vma
) 0)))
1276 h
->type
= bfd_link_hash_defined
;
1277 h
->u
.def
.section
= section
;
1278 h
->u
.def
.value
= value
;
1280 /* If we have been asked to, we act like collect2 and
1281 identify all functions that might be global constructors
1282 and destructors and pass them up in a callback. We only
1283 do this for certain object file types, since many object
1284 file types can handle this automatically. */
1285 if (constructor
&& name
[0] == '_')
1289 /* A constructor or destructor name starts like this:
1290 _+GLOBAL_[_.$][ID][_.$]
1291 where the first [_.$] and the second are the same
1292 character (we accept any character there, in case a
1293 new object file format comes along with even worse
1294 naming restrictions). */
1296 #define CONS_PREFIX "GLOBAL_"
1297 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1)
1303 && strncmp (s
, CONS_PREFIX
, CONS_PREFIX_LEN
- 1) == 0)
1307 c
= s
[CONS_PREFIX_LEN
+ 1];
1308 if ((c
== 'I' || c
== 'D')
1309 && s
[CONS_PREFIX_LEN
] == s
[CONS_PREFIX_LEN
+ 2])
1311 if (! ((*info
->callbacks
->constructor
)
1313 c
== 'I' ? true : false, bitsize
,
1314 name
, abfd
, section
, value
)))
1322 if (h
->type
== bfd_link_hash_new
)
1323 bfd_link_add_undef (info
->hash
, h
);
1324 h
->type
= bfd_link_hash_common
;
1325 h
->u
.c
.size
= value
;
1326 if (section
== &bfd_com_section
)
1328 h
->u
.c
.section
= bfd_make_section_old_way (abfd
, "COMMON");
1329 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1331 else if (section
->owner
!= abfd
)
1333 h
->u
.c
.section
= bfd_make_section_old_way (abfd
, section
->name
);
1334 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1337 h
->u
.c
.section
= section
;
1342 BFD_ASSERT (h
->type
== bfd_link_hash_common
);
1343 if (! ((*info
->callbacks
->multiple_common
)
1345 h
->u
.c
.section
->owner
, bfd_link_hash_common
, h
->u
.c
.size
,
1346 abfd
, bfd_link_hash_common
, value
)))
1348 if (value
> h
->u
.c
.size
)
1349 h
->u
.c
.size
= value
;
1352 BFD_ASSERT (h
->type
== bfd_link_hash_defined
);
1353 if (! ((*info
->callbacks
->multiple_common
)
1355 h
->u
.def
.section
->owner
, bfd_link_hash_defined
, (bfd_vma
) 0,
1356 abfd
, bfd_link_hash_common
, value
)))
1366 case bfd_link_hash_defined
:
1367 msec
= h
->u
.def
.section
;
1368 mval
= h
->u
.def
.value
;
1370 case bfd_link_hash_common
:
1371 msec
= &bfd_com_section
;
1374 case bfd_link_hash_indirect
:
1375 msec
= &bfd_ind_section
;
1382 if (! ((*info
->callbacks
->multiple_definition
)
1383 (info
, name
, msec
->owner
, msec
, mval
, abfd
, section
,
1390 struct bfd_link_hash_entry
*inh
;
1392 /* STRING is the name of the symbol we want to indirect
1394 inh
= bfd_link_hash_lookup (info
->hash
, string
, true, copy
,
1396 if (inh
== (struct bfd_link_hash_entry
*) NULL
)
1398 if (inh
->type
== bfd_link_hash_new
)
1400 inh
->type
= bfd_link_hash_undefined
;
1401 inh
->u
.undef
.abfd
= abfd
;
1402 bfd_link_add_undef (info
->hash
, inh
);
1404 h
->type
= bfd_link_hash_indirect
;
1409 if (! (*info
->callbacks
->add_to_set
) (info
, h
, bitsize
, abfd
,
1415 if (h
->u
.i
.warning
!= NULL
)
1417 if (! (*info
->callbacks
->warning
) (info
, h
->u
.i
.warning
))
1419 /* Only issue a warning once. */
1420 h
->u
.i
.warning
= NULL
;
1431 struct bfd_link_hash_entry
*sub
;
1433 /* STRING is the warning to give. */
1434 sub
= ((struct bfd_link_hash_entry
*)
1435 bfd_hash_allocate (&info
->hash
->table
,
1436 sizeof (struct bfd_link_hash_entry
)));
1439 bfd_error
= no_memory
;
1443 h
->type
= bfd_link_hash_warning
;
1446 h
->u
.i
.warning
= string
;
1451 w
= bfd_hash_allocate (&info
->hash
->table
,
1452 strlen (string
) + 1);
1465 /* Generic final link routine. */
1468 _bfd_generic_final_link (abfd
, info
)
1470 struct bfd_link_info
*info
;
1474 struct bfd_link_order
*p
;
1476 struct generic_write_global_symbol_info wginfo
;
1478 abfd
->outsymbols
= (asymbol
**) NULL
;
1482 /* Build the output symbol table. This also reads in the symbols
1483 for all the input BFDs, keeping them in the outsymbols field. */
1484 for (sub
= info
->input_bfds
; sub
!= (bfd
*) NULL
; sub
= sub
->link_next
)
1485 if (! _bfd_generic_link_output_symbols (abfd
, sub
, info
, &outsymalloc
))
1488 /* Accumulate the global symbols. */
1490 wginfo
.output_bfd
= abfd
;
1491 wginfo
.psymalloc
= &outsymalloc
;
1492 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info
),
1493 _bfd_generic_link_write_global_symbol
,
1496 if (info
->relocateable
)
1498 /* Allocate space for the output relocs for each section. */
1499 for (o
= abfd
->sections
;
1500 o
!= (asection
*) NULL
;
1504 for (p
= o
->link_order_head
;
1505 p
!= (struct bfd_link_order
*) NULL
;
1508 if (p
->type
== bfd_indirect_link_order
)
1510 asection
*input_section
;
1512 bfd_size_type relsize
;
1514 bfd_size_type reloc_count
;
1516 input_section
= p
->u
.indirect
.section
;
1517 input_bfd
= input_section
->owner
;
1518 relsize
= bfd_get_reloc_upper_bound (input_bfd
,
1520 relocs
= (arelent
**) malloc ((size_t) relsize
);
1523 bfd_error
= no_memory
;
1527 bfd_canonicalize_reloc (input_bfd
, input_section
,
1529 bfd_get_outsymbols (input_bfd
));
1530 BFD_ASSERT (reloc_count
== input_section
->reloc_count
);
1531 o
->reloc_count
+= reloc_count
;
1535 if (o
->reloc_count
> 0)
1537 o
->orelocation
= ((arelent
**)
1540 * sizeof (arelent
*))));
1541 if (!o
->orelocation
)
1543 bfd_error
= no_memory
;
1546 /* Reset the count so that it can be used as an index
1547 when putting in the output relocs. */
1553 /* Handle all the link order information for the sections. */
1554 for (o
= abfd
->sections
;
1555 o
!= (asection
*) NULL
;
1558 for (p
= o
->link_order_head
;
1559 p
!= (struct bfd_link_order
*) NULL
;
1562 if (! _bfd_default_link_order (abfd
, info
, o
, p
))
1570 /* Add an output symbol to the output BFD. */
1573 generic_add_output_symbol (output_bfd
, psymalloc
, sym
)
1578 if (output_bfd
->symcount
>= *psymalloc
)
1582 if (*psymalloc
== 0)
1586 if (output_bfd
->outsymbols
== (asymbol
**) NULL
)
1587 newsyms
= (asymbol
**) malloc (*psymalloc
* sizeof (asymbol
*));
1589 newsyms
= (asymbol
**) realloc (output_bfd
->outsymbols
,
1590 *psymalloc
* sizeof (asymbol
*));
1591 if (newsyms
== (asymbol
**) NULL
)
1593 bfd_error
= no_memory
;
1596 output_bfd
->outsymbols
= newsyms
;
1599 output_bfd
->outsymbols
[output_bfd
->symcount
] = sym
;
1600 ++output_bfd
->symcount
;
1605 /* Handle the symbols for an input BFD. */
1608 _bfd_generic_link_output_symbols (output_bfd
, input_bfd
, info
, psymalloc
)
1611 struct bfd_link_info
*info
;
1618 symsize
= get_symtab_upper_bound (input_bfd
);
1619 input_bfd
->outsymbols
= (asymbol
**) bfd_alloc (input_bfd
, symsize
);
1620 if (!input_bfd
->outsymbols
)
1622 bfd_error
= no_memory
;
1625 input_bfd
->symcount
= bfd_canonicalize_symtab (input_bfd
,
1626 input_bfd
->outsymbols
);
1628 /* Create a filename symbol if we are supposed to. */
1629 if (info
->create_object_symbols_section
!= (asection
*) NULL
)
1633 for (sec
= input_bfd
->sections
;
1634 sec
!= (asection
*) NULL
;
1637 if (sec
->output_section
== info
->create_object_symbols_section
)
1641 newsym
= bfd_make_empty_symbol (input_bfd
);
1644 newsym
->name
= input_bfd
->filename
;
1646 newsym
->flags
= BSF_LOCAL
| BSF_FILE
;
1647 newsym
->section
= sec
;
1649 if (! generic_add_output_symbol (output_bfd
, psymalloc
,
1658 /* Adjust the values of the globally visible symbols, and write out
1660 sym_ptr
= bfd_get_outsymbols (input_bfd
);
1661 sym_end
= sym_ptr
+ bfd_get_symcount (input_bfd
);
1662 for (; sym_ptr
< sym_end
; sym_ptr
++)
1665 struct generic_link_hash_entry
*h
;
1668 h
= (struct generic_link_hash_entry
*) NULL
;
1670 if ((sym
->flags
& (BSF_INDIRECT
1675 || bfd_get_section (sym
) == &bfd_und_section
1676 || bfd_is_com_section (bfd_get_section (sym
))
1677 || bfd_get_section (sym
) == &bfd_ind_section
)
1679 h
= _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info
),
1680 bfd_asymbol_name (sym
),
1681 false, false, true);
1682 if (h
!= (struct generic_link_hash_entry
*) NULL
)
1684 /* Force all references to this symbol to point to
1685 the same area in memory. It is possible that
1686 this routine will be called with a hash table
1687 other than a generic hash table, so we double
1689 if (info
->hash
->creator
== input_bfd
->xvec
)
1691 if (h
->sym
!= (asymbol
*) NULL
)
1692 *sym_ptr
= sym
= h
->sym
;
1695 switch (h
->root
.type
)
1698 case bfd_link_hash_new
:
1700 case bfd_link_hash_undefined
:
1701 case bfd_link_hash_weak
:
1703 case bfd_link_hash_defined
:
1704 sym
->value
= h
->root
.u
.def
.value
;
1705 sym
->section
= h
->root
.u
.def
.section
;
1706 sym
->flags
|= BSF_GLOBAL
;
1708 case bfd_link_hash_common
:
1709 sym
->value
= h
->root
.u
.c
.size
;
1710 sym
->flags
|= BSF_GLOBAL
;
1711 if (! bfd_is_com_section (sym
->section
))
1713 BFD_ASSERT (sym
->section
== &bfd_und_section
);
1714 sym
->section
= &bfd_com_section
;
1716 /* We do not set the section of the symbol to
1717 h->root.u.c.section. That value was saved so
1718 that we would know where to allocate the symbol
1719 if it was defined. In this case the type is
1720 still bfd_link_hash_common, so we did not define
1721 it, so we do not want to use that section. */
1727 /* This switch is straight from the old code in
1728 write_file_locals in ldsym.c. */
1729 if (info
->strip
== strip_some
1730 && (bfd_hash_lookup (info
->keep_hash
, bfd_asymbol_name (sym
),
1732 == (struct bfd_hash_entry
*) NULL
))
1734 else if ((sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
)) != 0)
1736 /* If this symbol is marked as occurring now, rather
1737 than at the end, output it now. This is used for
1738 COFF C_EXT FCN symbols. FIXME: There must be a
1740 if (bfd_asymbol_bfd (sym
) == input_bfd
1741 && (sym
->flags
& BSF_NOT_AT_END
) != 0)
1746 else if (sym
->section
== &bfd_ind_section
)
1748 else if ((sym
->flags
& BSF_DEBUGGING
) != 0)
1750 if (info
->strip
== strip_none
)
1755 else if (sym
->section
== &bfd_und_section
1756 || bfd_is_com_section (sym
->section
))
1758 else if ((sym
->flags
& BSF_LOCAL
) != 0)
1760 if ((sym
->flags
& BSF_WARNING
) != 0)
1764 switch (info
->discard
)
1771 if (bfd_asymbol_name (sym
)[0] == info
->lprefix
[0]
1772 && (info
->lprefix_len
== 1
1773 || strncmp (bfd_asymbol_name (sym
), info
->lprefix
,
1774 info
->lprefix_len
) == 0))
1785 else if ((sym
->flags
& BSF_CONSTRUCTOR
))
1787 if (info
->strip
!= strip_all
)
1797 if (! generic_add_output_symbol (output_bfd
, psymalloc
, sym
))
1799 if (h
!= (struct generic_link_hash_entry
*) NULL
)
1800 h
->root
.written
= true;
1807 /* Write out a global symbol, if it hasn't already been written out.
1808 This is called for each symbol in the hash table. */
1811 _bfd_generic_link_write_global_symbol (h
, data
)
1812 struct generic_link_hash_entry
*h
;
1815 struct generic_write_global_symbol_info
*wginfo
=
1816 (struct generic_write_global_symbol_info
*) data
;
1819 if (h
->root
.written
)
1822 h
->root
.written
= true;
1824 if (wginfo
->info
->strip
== strip_all
1825 || (wginfo
->info
->strip
== strip_some
1826 && bfd_hash_lookup (wginfo
->info
->keep_hash
, h
->root
.root
.string
,
1827 false, false) == NULL
))
1830 if (h
->sym
!= (asymbol
*) NULL
)
1833 BFD_ASSERT (strcmp (bfd_asymbol_name (sym
), h
->root
.root
.string
) == 0);
1837 sym
= bfd_make_empty_symbol (wginfo
->output_bfd
);
1840 sym
->name
= h
->root
.root
.string
;
1844 switch (h
->root
.type
)
1847 case bfd_link_hash_new
:
1849 case bfd_link_hash_undefined
:
1850 sym
->section
= &bfd_und_section
;
1853 case bfd_link_hash_weak
:
1854 sym
->section
= &bfd_und_section
;
1856 sym
->flags
|= BSF_WEAK
;
1857 case bfd_link_hash_defined
:
1858 sym
->section
= h
->root
.u
.def
.section
;
1859 sym
->value
= h
->root
.u
.def
.value
;
1861 case bfd_link_hash_common
:
1862 sym
->value
= h
->root
.u
.c
.size
;
1863 if (! bfd_is_com_section (sym
->section
))
1865 BFD_ASSERT (sym
->section
== &bfd_und_section
);
1866 sym
->section
= &bfd_com_section
;
1868 /* Do not set the section; see _bfd_generic_link_output_symbols. */
1870 case bfd_link_hash_indirect
:
1871 case bfd_link_hash_warning
:
1872 /* FIXME: What should we do here? */
1876 sym
->flags
|= BSF_GLOBAL
;
1878 if (! generic_add_output_symbol (wginfo
->output_bfd
, wginfo
->psymalloc
,
1881 /* FIXME: No way to return failure. */
1888 /* Allocate a new link_order for a section. */
1890 struct bfd_link_order
*
1891 bfd_new_link_order (abfd
, section
)
1895 struct bfd_link_order
*new;
1897 new = ((struct bfd_link_order
*)
1898 bfd_alloc_by_size_t (abfd
, sizeof (struct bfd_link_order
)));
1901 bfd_error
= no_memory
;
1905 new->type
= bfd_undefined_link_order
;
1908 new->next
= (struct bfd_link_order
*) NULL
;
1910 if (section
->link_order_tail
!= (struct bfd_link_order
*) NULL
)
1911 section
->link_order_tail
->next
= new;
1913 section
->link_order_head
= new;
1914 section
->link_order_tail
= new;
1919 /* Default link order processing routine. */
1922 _bfd_default_link_order (abfd
, info
, sec
, link_order
)
1924 struct bfd_link_info
*info
;
1926 struct bfd_link_order
*link_order
;
1928 switch (link_order
->type
)
1930 case bfd_undefined_link_order
:
1933 case bfd_indirect_link_order
:
1934 return default_indirect_link_order (abfd
, info
, sec
, link_order
);
1935 case bfd_fill_link_order
:
1936 return default_fill_link_order (abfd
, info
, sec
, link_order
);
1940 /* Default routine to handle a bfd_fill_link_order. */
1944 default_fill_link_order (abfd
, info
, sec
, link_order
)
1946 struct bfd_link_info
*info
;
1948 struct bfd_link_order
*link_order
;
1955 BFD_ASSERT ((sec
->flags
& SEC_HAS_CONTENTS
) != 0);
1957 size
= (size_t) link_order
->size
;
1958 space
= (char *) alloca (size
);
1959 fill
= link_order
->u
.fill
.value
;
1960 for (i
= 0; i
< size
; i
+= 2)
1961 space
[i
] = fill
>> 8;
1962 for (i
= 1; i
< size
; i
+= 2)
1964 return bfd_set_section_contents (abfd
, sec
, space
,
1965 (file_ptr
) link_order
->offset
,
1969 /* Default routine to handle a bfd_indirect_link_order. */
1972 default_indirect_link_order (output_bfd
, info
, output_section
, link_order
)
1974 struct bfd_link_info
*info
;
1975 asection
*output_section
;
1976 struct bfd_link_order
*link_order
;
1978 asection
*input_section
;
1982 BFD_ASSERT ((output_section
->flags
& SEC_HAS_CONTENTS
) != 0);
1984 if (link_order
->size
== 0)
1987 input_section
= link_order
->u
.indirect
.section
;
1988 input_bfd
= input_section
->owner
;
1990 BFD_ASSERT (input_section
->output_section
== output_section
);
1991 BFD_ASSERT (input_section
->output_offset
== link_order
->offset
);
1992 BFD_ASSERT (bfd_section_size (input_bfd
, input_section
) == link_order
->size
);
1994 if (info
->relocateable
1995 && input_section
->reloc_count
> 0
1996 && output_section
->orelocation
== (arelent
**) NULL
)
1998 /* Space has not been allocated for the output relocations.
1999 This can happen when we are called by a specific backend
2000 because somebody is attempting to link together different
2001 types of object files. Handling this case correctly is
2002 difficult, and sometimes impossible. */
2006 /* Get the canonical symbols. The generic linker will always have
2007 retrieved them by this point, but we may be being called by a
2008 specific linker when linking different types of object files
2010 if (bfd_get_outsymbols (input_bfd
) == (asymbol
**) NULL
)
2014 symsize
= get_symtab_upper_bound (input_bfd
);
2015 input_bfd
->outsymbols
= (asymbol
**) bfd_alloc (input_bfd
, symsize
);
2016 if (!input_bfd
->outsymbols
)
2018 bfd_error
= no_memory
;
2021 input_bfd
->symcount
= bfd_canonicalize_symtab (input_bfd
,
2022 input_bfd
->outsymbols
);
2025 /* Get and relocate the section contents. */
2026 contents
= (bfd_byte
*) alloca (bfd_section_size (input_bfd
, input_section
));
2027 contents
= (bfd_get_relocated_section_contents
2028 (output_bfd
, info
, link_order
, contents
, info
->relocateable
,
2029 bfd_get_outsymbols (input_bfd
)));
2033 /* Output the section contents. */
2034 if (! bfd_set_section_contents (output_bfd
, output_section
, (PTR
) contents
,
2035 link_order
->offset
, link_order
->size
))