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_set_error (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_set_error (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_set_error (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_set_error (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_set_error (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_set_error (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
, **pp
;
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
));
819 for (pp
= &arh
->defs
;
820 *pp
!= (struct archive_list
*) NULL
;
829 /* New undefined symbols are added to the end of the list, so we
830 only need to look through it once. */
831 pundef
= &info
->hash
->undefs
;
832 while (*pundef
!= (struct bfd_link_hash_entry
*) NULL
)
834 struct bfd_link_hash_entry
*h
;
835 struct archive_hash_entry
*arh
;
836 struct archive_list
*l
;
840 /* When a symbol is defined, it is not necessarily removed from
842 if (h
->type
!= bfd_link_hash_undefined
843 && h
->type
!= bfd_link_hash_common
)
845 /* Remove this entry from the list, for general cleanliness
846 and because we are going to look through the list again
847 if we search any more libraries. We can't remove the
848 entry if it is the tail, because that would lose any
849 entries we add to the list later on. */
850 if (*pundef
!= info
->hash
->undefs_tail
)
851 *pundef
= (*pundef
)->next
;
853 pundef
= &(*pundef
)->next
;
857 /* Look for this symbol in the archive symbol map. */
858 arh
= archive_hash_lookup (&arsym_hash
, h
->root
.string
, false, false);
859 if (arh
== (struct archive_hash_entry
*) NULL
)
861 pundef
= &(*pundef
)->next
;
865 /* Look at all the objects which define this symbol. */
866 for (l
= arh
->defs
; l
!= (struct archive_list
*) NULL
; l
= l
->next
)
871 /* If the symbol has gotten defined along the way, quit. */
872 if (h
->type
!= bfd_link_hash_undefined
873 && h
->type
!= bfd_link_hash_common
)
876 element
= bfd_get_elt_at_index (abfd
, l
->indx
);
877 if (element
== (bfd
*) NULL
)
880 /* If we've already included this element, or if we've
881 already checked it on this pass, continue. */
882 if (element
->archive_pass
== -1
883 || element
->archive_pass
== pass
)
886 /* If we can't figure this element out, just ignore it. */
887 if (! bfd_check_format (element
, bfd_object
))
889 element
->archive_pass
= -1;
893 /* CHECKFN will see if this element should be included, and
894 go ahead and include it if appropriate. */
895 if (! (*checkfn
) (element
, info
, &needed
))
899 element
->archive_pass
= pass
;
902 element
->archive_pass
= -1;
904 /* Increment the pass count to show that we may need to
905 recheck object files which were already checked. */
910 pundef
= &(*pundef
)->next
;
913 archive_hash_table_free (&arsym_hash
);
918 /* See if we should include an archive element. */
921 generic_link_check_archive_element (abfd
, info
, pneeded
)
923 struct bfd_link_info
*info
;
928 bfd_size_type symbol_count
;
929 asymbol
**pp
, **ppend
;
933 symsize
= get_symtab_upper_bound (abfd
);
934 symbols
= (asymbol
**) alloca (symsize
);
935 symbol_count
= bfd_canonicalize_symtab (abfd
, symbols
);
938 ppend
= symbols
+ symbol_count
;
939 for (; pp
< ppend
; pp
++)
942 struct bfd_link_hash_entry
*h
;
946 /* We are only interested in globally visible symbols. */
947 if (! bfd_is_com_section (p
->section
)
948 && (p
->flags
& (BSF_GLOBAL
| BSF_INDIRECT
| BSF_WEAK
)) == 0)
951 /* We are only interested if we know something about this
952 symbol, and it is undefined or common. An undefined weak
953 symbol (type bfd_link_hash_weak) is not considered to be a
954 reference when pulling files out of an archive. See the SVR4
956 h
= bfd_link_hash_lookup (info
->hash
, bfd_asymbol_name (p
), false,
958 if (h
== (struct bfd_link_hash_entry
*) NULL
959 || (h
->type
!= bfd_link_hash_undefined
960 && h
->type
!= bfd_link_hash_common
))
963 /* P is a symbol we are looking for. */
965 if (! bfd_is_com_section (p
->section
))
967 /* This object file defines this symbol, so pull it in. */
968 if (! (*info
->callbacks
->add_archive_element
) (info
, abfd
,
969 bfd_asymbol_name (p
)))
971 if (! generic_link_add_symbol_list (abfd
, info
, symbol_count
,
978 /* P is a common symbol. */
980 if (h
->type
== bfd_link_hash_undefined
)
984 symbfd
= h
->u
.undef
.abfd
;
985 if (symbfd
== (bfd
*) NULL
)
987 /* This symbol was created as undefined from outside
988 BFD. We assume that we should link in the object
989 file. This is for the -u option in the linker. */
990 if (! (*info
->callbacks
->add_archive_element
)
991 (info
, abfd
, bfd_asymbol_name (p
)))
997 /* Turn the symbol into a common symbol but do not link in
998 the object file. This is how a.out works. Object
999 formats that require different semantics must implement
1000 this function differently. This symbol is already on the
1001 undefs list. We add the section to a common section
1002 attached to symbfd to ensure that it is in a BFD which
1003 will be linked in. */
1004 h
->type
= bfd_link_hash_common
;
1005 h
->u
.c
.size
= bfd_asymbol_value (p
);
1006 if (p
->section
== &bfd_com_section
)
1007 h
->u
.c
.section
= bfd_make_section_old_way (symbfd
, "COMMON");
1009 h
->u
.c
.section
= bfd_make_section_old_way (symbfd
,
1011 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1015 /* Adjust the size of the common symbol if necessary. This
1016 is how a.out works. Object formats that require
1017 different semantics must implement this function
1019 if (bfd_asymbol_value (p
) > h
->u
.c
.size
)
1020 h
->u
.c
.size
= bfd_asymbol_value (p
);
1024 /* This archive element is not needed. */
1028 /* Add the symbol from an object file to the global hash table. */
1031 generic_link_add_symbol_list (abfd
, info
, symbol_count
, symbols
)
1033 struct bfd_link_info
*info
;
1034 bfd_size_type symbol_count
;
1037 asymbol
**pp
, **ppend
;
1040 ppend
= symbols
+ symbol_count
;
1041 for (; pp
< ppend
; pp
++)
1047 if ((p
->flags
& (BSF_INDIRECT
1052 || bfd_get_section (p
) == &bfd_und_section
1053 || bfd_is_com_section (bfd_get_section (p
))
1054 || bfd_get_section (p
) == &bfd_ind_section
)
1058 struct generic_link_hash_entry
*h
;
1060 name
= bfd_asymbol_name (p
);
1061 if ((p
->flags
& BSF_INDIRECT
) != 0
1062 || p
->section
== &bfd_ind_section
)
1063 string
= bfd_asymbol_name ((asymbol
*) p
->value
);
1064 else if ((p
->flags
& BSF_WARNING
) != 0)
1066 /* The name of P is actually the warning string, and the
1067 value is actually a pointer to the symbol to warn
1070 name
= bfd_asymbol_name ((asymbol
*) p
->value
);
1075 /* We pass the constructor argument as false, for
1076 compatibility. As backends are converted they can
1077 arrange to pass the right value (the right value is the
1078 size of a function pointer if gcc uses collect2 for the
1079 object file format, zero if it does not).
1080 FIXME: We pass the bitsize as 32, which is just plain
1081 wrong, but actually doesn't matter very much. */
1082 if (! (_bfd_generic_link_add_one_symbol
1083 (info
, abfd
, name
, p
->flags
, bfd_get_section (p
),
1084 p
->value
, string
, false, 0, 32,
1085 (struct bfd_link_hash_entry
**) &h
)))
1088 /* Save the BFD symbol so that we don't lose any backend
1089 specific information that may be attached to it. We only
1090 want this one if it gives more information than the
1091 existing one; we don't want to replace a defined symbol
1092 with an undefined one. This routine may be called with a
1093 hash table other than the generic hash table, so we only
1094 do this if we are certain that the hash table is a
1096 if (info
->hash
->creator
== abfd
->xvec
)
1098 if (h
->sym
== (asymbol
*) NULL
1099 || (bfd_get_section (p
) != &bfd_und_section
1100 && (! bfd_is_com_section (bfd_get_section (p
))
1101 || (bfd_get_section (h
->sym
) == &bfd_und_section
))))
1104 /* BSF_OLD_COMMON is a hack to support COFF reloc
1105 reading, and it should go away when the COFF
1106 linker is switched to the new version. */
1107 if (bfd_is_com_section (bfd_get_section (p
)))
1108 p
->flags
|= BSF_OLD_COMMON
;
1117 /* We use a state table to deal with adding symbols from an object
1118 file. The first index into the state table describes the symbol
1119 from the object file. The second index into the state table is the
1120 type of the symbol in the hash table. */
1122 /* The symbol from the object file is turned into one of these row
1127 UNDEF_ROW
, /* Undefined. */
1128 UNDEFW_ROW
, /* Weak undefined. */
1129 DEF_ROW
, /* Defined. */
1130 DEFW_ROW
, /* Weak defined. */
1131 COMMON_ROW
, /* Common. */
1132 INDR_ROW
, /* Indirect. */
1133 WARN_ROW
, /* Warning. */
1134 SET_ROW
/* Member of set. */
1137 /* The actions to take in the state table. */
1142 UND
, /* Mark symbol undefined. */
1143 WEAK
, /* Mark symbol weak undefined. */
1144 DEF
, /* Mark symbol defined. */
1145 COM
, /* Mark symbol common. */
1146 CREF
, /* Possibly warn about common reference to defined symbol. */
1147 CDEF
, /* Define existing common symbol. */
1148 NOACT
, /* No action. */
1149 BIG
, /* Mark symbol common using largest size. */
1150 MDEF
, /* Multiple definition error. */
1151 IND
, /* Make indirect symbol. */
1152 SET
, /* Add value to set. */
1153 MWARN
, /* Make warning symbol. */
1154 WARN
, /* Issue warning. */
1155 CYCLE
, /* Repeat with symbol pointed to. */
1156 WARNC
/* Issue warning and then CYCLE. */
1159 /* The state table itself. The first index is a link_row and the
1160 second index is a bfd_link_hash_type. */
1162 static const enum link_action link_action
[8][7] =
1164 /* current\prev new undef weak def com indr warn */
1165 /* UNDEF_ROW */ {UND
, NOACT
, NOACT
, NOACT
, NOACT
, CYCLE
, WARNC
},
1166 /* UNDEFW_ROW */ {WEAK
, WEAK
, NOACT
, NOACT
, NOACT
, CYCLE
, WARNC
},
1167 /* DEF_ROW */ {DEF
, DEF
, DEF
, MDEF
, CDEF
, CYCLE
, CYCLE
},
1168 /* DEFW_ROW */ {DEF
, DEF
, DEF
, NOACT
, NOACT
, CYCLE
, CYCLE
},
1169 /* COMMON_ROW */ {COM
, COM
, COM
, CREF
, BIG
, CYCLE
, WARNC
},
1170 /* INDR_ROW */ {IND
, IND
, IND
, MDEF
, MDEF
, MDEF
, WARNC
},
1171 /* WARN_ROW */ {MWARN
, WARN
, WARN
, MWARN
, MWARN
, MWARN
, NOACT
},
1172 /* SET_ROW */ {SET
, SET
, SET
, SET
, SET
, CYCLE
, WARNC
}
1175 /* Add a symbol to the global hash table.
1176 ABFD is the BFD the symbol comes from.
1177 NAME is the name of the symbol.
1178 FLAGS is the BSF_* bits associated with the symbol.
1179 SECTION is the section in which the symbol is defined; this may be
1180 bfd_und_section or bfd_com_section.
1181 VALUE is the value of the symbol, relative to the section.
1182 STRING is used for either an indirect symbol, in which case it is
1183 the name of the symbol to indirect to, or a warning symbol, in
1184 which case it is the warning string.
1185 COPY is true if NAME or STRING must be copied into locally
1186 allocated memory if they need to be saved.
1187 CONSTRUCTOR is true if we should automatically collect gcc
1188 constructor or destructor names.
1189 BITSIZE is the number of bits in constructor or set entries.
1190 HASHP, if not NULL, is a place to store the created hash table
1194 _bfd_generic_link_add_one_symbol (info
, abfd
, name
, flags
, section
, value
,
1195 string
, copy
, constructor
, bitsize
, hashp
)
1196 struct bfd_link_info
*info
;
1204 boolean constructor
;
1205 unsigned int bitsize
;
1206 struct bfd_link_hash_entry
**hashp
;
1209 struct bfd_link_hash_entry
*h
;
1212 if (section
== &bfd_ind_section
1213 || (flags
& BSF_INDIRECT
) != 0)
1215 else if ((flags
& BSF_WARNING
) != 0)
1217 else if ((flags
& BSF_CONSTRUCTOR
) != 0)
1219 else if (section
== &bfd_und_section
)
1221 if ((flags
& BSF_WEAK
) != 0)
1226 else if ((flags
& BSF_WEAK
) != 0)
1228 else if (bfd_is_com_section (section
))
1233 h
= bfd_link_hash_lookup (info
->hash
, name
, true, copy
, false);
1234 if (h
== (struct bfd_link_hash_entry
*) NULL
)
1236 if (hashp
!= (struct bfd_link_hash_entry
**) NULL
)
1241 if (info
->notice_hash
!= (struct bfd_hash_table
*) NULL
1242 && (bfd_hash_lookup (info
->notice_hash
, name
, false, false)
1243 != (struct bfd_hash_entry
*) NULL
))
1245 if (! (*info
->callbacks
->notice
) (info
, name
, abfd
, section
, value
))
1249 if (hashp
!= (struct bfd_link_hash_entry
**) NULL
)
1254 enum link_action action
;
1257 action
= link_action
[(int) row
][(int) h
->type
];
1263 h
->type
= bfd_link_hash_undefined
;
1264 h
->u
.undef
.abfd
= abfd
;
1265 bfd_link_add_undef (info
->hash
, h
);
1268 h
->type
= bfd_link_hash_weak
;
1269 h
->u
.undef
.abfd
= abfd
;
1272 BFD_ASSERT (h
->type
== bfd_link_hash_common
);
1273 if (! ((*info
->callbacks
->multiple_common
)
1275 h
->u
.c
.section
->owner
, bfd_link_hash_common
, h
->u
.c
.size
,
1276 abfd
, bfd_link_hash_defined
, (bfd_vma
) 0)))
1280 h
->type
= bfd_link_hash_defined
;
1281 h
->u
.def
.section
= section
;
1282 h
->u
.def
.value
= value
;
1284 /* If we have been asked to, we act like collect2 and
1285 identify all functions that might be global constructors
1286 and destructors and pass them up in a callback. We only
1287 do this for certain object file types, since many object
1288 file types can handle this automatically. */
1289 if (constructor
&& name
[0] == '_')
1293 /* A constructor or destructor name starts like this:
1294 _+GLOBAL_[_.$][ID][_.$]
1295 where the first [_.$] and the second are the same
1296 character (we accept any character there, in case a
1297 new object file format comes along with even worse
1298 naming restrictions). */
1300 #define CONS_PREFIX "GLOBAL_"
1301 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1)
1307 && strncmp (s
, CONS_PREFIX
, CONS_PREFIX_LEN
- 1) == 0)
1311 c
= s
[CONS_PREFIX_LEN
+ 1];
1312 if ((c
== 'I' || c
== 'D')
1313 && s
[CONS_PREFIX_LEN
] == s
[CONS_PREFIX_LEN
+ 2])
1315 if (! ((*info
->callbacks
->constructor
)
1317 c
== 'I' ? true : false, bitsize
,
1318 name
, abfd
, section
, value
)))
1326 if (h
->type
== bfd_link_hash_new
)
1327 bfd_link_add_undef (info
->hash
, h
);
1328 h
->type
= bfd_link_hash_common
;
1329 h
->u
.c
.size
= value
;
1330 if (section
== &bfd_com_section
)
1332 h
->u
.c
.section
= bfd_make_section_old_way (abfd
, "COMMON");
1333 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1335 else if (section
->owner
!= abfd
)
1337 h
->u
.c
.section
= bfd_make_section_old_way (abfd
, section
->name
);
1338 h
->u
.c
.section
->flags
= SEC_ALLOC
;
1341 h
->u
.c
.section
= section
;
1346 BFD_ASSERT (h
->type
== bfd_link_hash_common
);
1347 if (! ((*info
->callbacks
->multiple_common
)
1349 h
->u
.c
.section
->owner
, bfd_link_hash_common
, h
->u
.c
.size
,
1350 abfd
, bfd_link_hash_common
, value
)))
1352 if (value
> h
->u
.c
.size
)
1353 h
->u
.c
.size
= value
;
1356 BFD_ASSERT (h
->type
== bfd_link_hash_defined
);
1357 if (! ((*info
->callbacks
->multiple_common
)
1359 h
->u
.def
.section
->owner
, bfd_link_hash_defined
, (bfd_vma
) 0,
1360 abfd
, bfd_link_hash_common
, value
)))
1370 case bfd_link_hash_defined
:
1371 msec
= h
->u
.def
.section
;
1372 mval
= h
->u
.def
.value
;
1374 case bfd_link_hash_common
:
1375 msec
= &bfd_com_section
;
1378 case bfd_link_hash_indirect
:
1379 msec
= &bfd_ind_section
;
1386 if (! ((*info
->callbacks
->multiple_definition
)
1387 (info
, name
, msec
->owner
, msec
, mval
, abfd
, section
,
1394 struct bfd_link_hash_entry
*inh
;
1396 /* STRING is the name of the symbol we want to indirect
1398 inh
= bfd_link_hash_lookup (info
->hash
, string
, true, copy
,
1400 if (inh
== (struct bfd_link_hash_entry
*) NULL
)
1402 if (inh
->type
== bfd_link_hash_new
)
1404 inh
->type
= bfd_link_hash_undefined
;
1405 inh
->u
.undef
.abfd
= abfd
;
1406 bfd_link_add_undef (info
->hash
, inh
);
1408 h
->type
= bfd_link_hash_indirect
;
1413 if (! (*info
->callbacks
->add_to_set
) (info
, h
, bitsize
, abfd
,
1419 if (h
->u
.i
.warning
!= NULL
)
1421 if (! (*info
->callbacks
->warning
) (info
, h
->u
.i
.warning
))
1423 /* Only issue a warning once. */
1424 h
->u
.i
.warning
= NULL
;
1435 struct bfd_link_hash_entry
*sub
;
1437 /* STRING is the warning to give. */
1438 sub
= ((struct bfd_link_hash_entry
*)
1439 bfd_hash_allocate (&info
->hash
->table
,
1440 sizeof (struct bfd_link_hash_entry
)));
1443 bfd_set_error (bfd_error_no_memory
);
1447 h
->type
= bfd_link_hash_warning
;
1450 h
->u
.i
.warning
= string
;
1455 w
= bfd_hash_allocate (&info
->hash
->table
,
1456 strlen (string
) + 1);
1469 /* Generic final link routine. */
1472 _bfd_generic_final_link (abfd
, info
)
1474 struct bfd_link_info
*info
;
1478 struct bfd_link_order
*p
;
1480 struct generic_write_global_symbol_info wginfo
;
1482 abfd
->outsymbols
= (asymbol
**) NULL
;
1486 /* Build the output symbol table. This also reads in the symbols
1487 for all the input BFDs, keeping them in the outsymbols field. */
1488 for (sub
= info
->input_bfds
; sub
!= (bfd
*) NULL
; sub
= sub
->link_next
)
1489 if (! _bfd_generic_link_output_symbols (abfd
, sub
, info
, &outsymalloc
))
1492 /* Accumulate the global symbols. */
1494 wginfo
.output_bfd
= abfd
;
1495 wginfo
.psymalloc
= &outsymalloc
;
1496 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info
),
1497 _bfd_generic_link_write_global_symbol
,
1500 if (info
->relocateable
)
1502 /* Allocate space for the output relocs for each section. */
1503 for (o
= abfd
->sections
;
1504 o
!= (asection
*) NULL
;
1508 for (p
= o
->link_order_head
;
1509 p
!= (struct bfd_link_order
*) NULL
;
1512 if (p
->type
== bfd_indirect_link_order
)
1514 asection
*input_section
;
1516 bfd_size_type relsize
;
1518 bfd_size_type reloc_count
;
1520 input_section
= p
->u
.indirect
.section
;
1521 input_bfd
= input_section
->owner
;
1522 relsize
= bfd_get_reloc_upper_bound (input_bfd
,
1524 relocs
= (arelent
**) malloc ((size_t) relsize
);
1527 bfd_set_error (bfd_error_no_memory
);
1531 bfd_canonicalize_reloc (input_bfd
, input_section
,
1533 bfd_get_outsymbols (input_bfd
));
1534 BFD_ASSERT (reloc_count
== input_section
->reloc_count
);
1535 o
->reloc_count
+= reloc_count
;
1539 if (o
->reloc_count
> 0)
1541 o
->orelocation
= ((arelent
**)
1544 * sizeof (arelent
*))));
1545 if (!o
->orelocation
)
1547 bfd_set_error (bfd_error_no_memory
);
1550 /* Reset the count so that it can be used as an index
1551 when putting in the output relocs. */
1557 /* Handle all the link order information for the sections. */
1558 for (o
= abfd
->sections
;
1559 o
!= (asection
*) NULL
;
1562 for (p
= o
->link_order_head
;
1563 p
!= (struct bfd_link_order
*) NULL
;
1566 if (! _bfd_default_link_order (abfd
, info
, o
, p
))
1574 /* Add an output symbol to the output BFD. */
1577 generic_add_output_symbol (output_bfd
, psymalloc
, sym
)
1582 if (output_bfd
->symcount
>= *psymalloc
)
1586 if (*psymalloc
== 0)
1590 if (output_bfd
->outsymbols
== (asymbol
**) NULL
)
1591 newsyms
= (asymbol
**) malloc (*psymalloc
* sizeof (asymbol
*));
1593 newsyms
= (asymbol
**) realloc (output_bfd
->outsymbols
,
1594 *psymalloc
* sizeof (asymbol
*));
1595 if (newsyms
== (asymbol
**) NULL
)
1597 bfd_set_error (bfd_error_no_memory
);
1600 output_bfd
->outsymbols
= newsyms
;
1603 output_bfd
->outsymbols
[output_bfd
->symcount
] = sym
;
1604 ++output_bfd
->symcount
;
1609 /* Handle the symbols for an input BFD. */
1612 _bfd_generic_link_output_symbols (output_bfd
, input_bfd
, info
, psymalloc
)
1615 struct bfd_link_info
*info
;
1622 /* Do not clobber outsymbols if they have already been created. */
1623 if (input_bfd
->outsymbols
== NULL
)
1625 symsize
= get_symtab_upper_bound (input_bfd
);
1626 input_bfd
->outsymbols
= (asymbol
**) bfd_alloc (input_bfd
, symsize
);
1627 if (!input_bfd
->outsymbols
)
1629 bfd_set_error (bfd_error_no_memory
);
1632 input_bfd
->symcount
= bfd_canonicalize_symtab (input_bfd
,
1633 input_bfd
->outsymbols
);
1636 /* Create a filename symbol if we are supposed to. */
1637 if (info
->create_object_symbols_section
!= (asection
*) NULL
)
1641 for (sec
= input_bfd
->sections
;
1642 sec
!= (asection
*) NULL
;
1645 if (sec
->output_section
== info
->create_object_symbols_section
)
1649 newsym
= bfd_make_empty_symbol (input_bfd
);
1652 newsym
->name
= input_bfd
->filename
;
1654 newsym
->flags
= BSF_LOCAL
| BSF_FILE
;
1655 newsym
->section
= sec
;
1657 if (! generic_add_output_symbol (output_bfd
, psymalloc
,
1666 /* Adjust the values of the globally visible symbols, and write out
1668 sym_ptr
= bfd_get_outsymbols (input_bfd
);
1669 sym_end
= sym_ptr
+ bfd_get_symcount (input_bfd
);
1670 for (; sym_ptr
< sym_end
; sym_ptr
++)
1673 struct generic_link_hash_entry
*h
;
1676 h
= (struct generic_link_hash_entry
*) NULL
;
1678 if ((sym
->flags
& (BSF_INDIRECT
1683 || bfd_get_section (sym
) == &bfd_und_section
1684 || bfd_is_com_section (bfd_get_section (sym
))
1685 || bfd_get_section (sym
) == &bfd_ind_section
)
1687 h
= _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info
),
1688 bfd_asymbol_name (sym
),
1689 false, false, true);
1690 if (h
!= (struct generic_link_hash_entry
*) NULL
)
1692 /* Force all references to this symbol to point to
1693 the same area in memory. It is possible that
1694 this routine will be called with a hash table
1695 other than a generic hash table, so we double
1697 if (info
->hash
->creator
== input_bfd
->xvec
)
1699 if (h
->sym
!= (asymbol
*) NULL
)
1700 *sym_ptr
= sym
= h
->sym
;
1703 switch (h
->root
.type
)
1706 case bfd_link_hash_new
:
1708 case bfd_link_hash_undefined
:
1709 case bfd_link_hash_weak
:
1711 case bfd_link_hash_defined
:
1712 sym
->value
= h
->root
.u
.def
.value
;
1713 sym
->section
= h
->root
.u
.def
.section
;
1714 sym
->flags
|= BSF_GLOBAL
;
1716 case bfd_link_hash_common
:
1717 sym
->value
= h
->root
.u
.c
.size
;
1718 sym
->flags
|= BSF_GLOBAL
;
1719 if (! bfd_is_com_section (sym
->section
))
1721 BFD_ASSERT (sym
->section
== &bfd_und_section
);
1722 sym
->section
= &bfd_com_section
;
1724 /* We do not set the section of the symbol to
1725 h->root.u.c.section. That value was saved so
1726 that we would know where to allocate the symbol
1727 if it was defined. In this case the type is
1728 still bfd_link_hash_common, so we did not define
1729 it, so we do not want to use that section. */
1735 /* This switch is straight from the old code in
1736 write_file_locals in ldsym.c. */
1737 if (info
->strip
== strip_some
1738 && (bfd_hash_lookup (info
->keep_hash
, bfd_asymbol_name (sym
),
1740 == (struct bfd_hash_entry
*) NULL
))
1742 else if ((sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
)) != 0)
1744 /* If this symbol is marked as occurring now, rather
1745 than at the end, output it now. This is used for
1746 COFF C_EXT FCN symbols. FIXME: There must be a
1748 if (bfd_asymbol_bfd (sym
) == input_bfd
1749 && (sym
->flags
& BSF_NOT_AT_END
) != 0)
1754 else if (sym
->section
== &bfd_ind_section
)
1756 else if ((sym
->flags
& BSF_DEBUGGING
) != 0)
1758 if (info
->strip
== strip_none
)
1763 else if (sym
->section
== &bfd_und_section
1764 || bfd_is_com_section (sym
->section
))
1766 else if ((sym
->flags
& BSF_LOCAL
) != 0)
1768 if ((sym
->flags
& BSF_WARNING
) != 0)
1772 switch (info
->discard
)
1779 if (bfd_asymbol_name (sym
)[0] == info
->lprefix
[0]
1780 && (info
->lprefix_len
== 1
1781 || strncmp (bfd_asymbol_name (sym
), info
->lprefix
,
1782 info
->lprefix_len
) == 0))
1793 else if ((sym
->flags
& BSF_CONSTRUCTOR
))
1795 if (info
->strip
!= strip_all
)
1805 if (! generic_add_output_symbol (output_bfd
, psymalloc
, sym
))
1807 if (h
!= (struct generic_link_hash_entry
*) NULL
)
1808 h
->root
.written
= true;
1815 /* Write out a global symbol, if it hasn't already been written out.
1816 This is called for each symbol in the hash table. */
1819 _bfd_generic_link_write_global_symbol (h
, data
)
1820 struct generic_link_hash_entry
*h
;
1823 struct generic_write_global_symbol_info
*wginfo
=
1824 (struct generic_write_global_symbol_info
*) data
;
1827 if (h
->root
.written
)
1830 h
->root
.written
= true;
1832 if (wginfo
->info
->strip
== strip_all
1833 || (wginfo
->info
->strip
== strip_some
1834 && bfd_hash_lookup (wginfo
->info
->keep_hash
, h
->root
.root
.string
,
1835 false, false) == NULL
))
1838 if (h
->sym
!= (asymbol
*) NULL
)
1841 BFD_ASSERT (strcmp (bfd_asymbol_name (sym
), h
->root
.root
.string
) == 0);
1845 sym
= bfd_make_empty_symbol (wginfo
->output_bfd
);
1848 sym
->name
= h
->root
.root
.string
;
1852 switch (h
->root
.type
)
1855 case bfd_link_hash_new
:
1857 case bfd_link_hash_undefined
:
1858 sym
->section
= &bfd_und_section
;
1861 case bfd_link_hash_weak
:
1862 sym
->section
= &bfd_und_section
;
1864 sym
->flags
|= BSF_WEAK
;
1866 case bfd_link_hash_defined
:
1867 sym
->section
= h
->root
.u
.def
.section
;
1868 sym
->value
= h
->root
.u
.def
.value
;
1870 case bfd_link_hash_common
:
1871 sym
->value
= h
->root
.u
.c
.size
;
1872 if (! bfd_is_com_section (sym
->section
))
1874 BFD_ASSERT (sym
->section
== &bfd_und_section
);
1875 sym
->section
= &bfd_com_section
;
1877 /* Do not set the section; see _bfd_generic_link_output_symbols. */
1879 case bfd_link_hash_indirect
:
1880 case bfd_link_hash_warning
:
1881 /* FIXME: What should we do here? */
1885 sym
->flags
|= BSF_GLOBAL
;
1887 if (! generic_add_output_symbol (wginfo
->output_bfd
, wginfo
->psymalloc
,
1890 /* FIXME: No way to return failure. */
1897 /* Allocate a new link_order for a section. */
1899 struct bfd_link_order
*
1900 bfd_new_link_order (abfd
, section
)
1904 struct bfd_link_order
*new;
1906 new = ((struct bfd_link_order
*)
1907 bfd_alloc_by_size_t (abfd
, sizeof (struct bfd_link_order
)));
1910 bfd_set_error (bfd_error_no_memory
);
1914 new->type
= bfd_undefined_link_order
;
1917 new->next
= (struct bfd_link_order
*) NULL
;
1919 if (section
->link_order_tail
!= (struct bfd_link_order
*) NULL
)
1920 section
->link_order_tail
->next
= new;
1922 section
->link_order_head
= new;
1923 section
->link_order_tail
= new;
1928 /* Default link order processing routine. */
1931 _bfd_default_link_order (abfd
, info
, sec
, link_order
)
1933 struct bfd_link_info
*info
;
1935 struct bfd_link_order
*link_order
;
1937 switch (link_order
->type
)
1939 case bfd_undefined_link_order
:
1942 case bfd_indirect_link_order
:
1943 return default_indirect_link_order (abfd
, info
, sec
, link_order
);
1944 case bfd_fill_link_order
:
1945 return default_fill_link_order (abfd
, info
, sec
, link_order
);
1949 /* Default routine to handle a bfd_fill_link_order. */
1953 default_fill_link_order (abfd
, info
, sec
, link_order
)
1955 struct bfd_link_info
*info
;
1957 struct bfd_link_order
*link_order
;
1964 BFD_ASSERT ((sec
->flags
& SEC_HAS_CONTENTS
) != 0);
1966 size
= (size_t) link_order
->size
;
1967 space
= (char *) alloca (size
);
1968 fill
= link_order
->u
.fill
.value
;
1969 for (i
= 0; i
< size
; i
+= 2)
1970 space
[i
] = fill
>> 8;
1971 for (i
= 1; i
< size
; i
+= 2)
1973 return bfd_set_section_contents (abfd
, sec
, space
,
1974 (file_ptr
) link_order
->offset
,
1978 /* Default routine to handle a bfd_indirect_link_order. */
1981 default_indirect_link_order (output_bfd
, info
, output_section
, link_order
)
1983 struct bfd_link_info
*info
;
1984 asection
*output_section
;
1985 struct bfd_link_order
*link_order
;
1987 asection
*input_section
;
1991 BFD_ASSERT ((output_section
->flags
& SEC_HAS_CONTENTS
) != 0);
1993 if (link_order
->size
== 0)
1996 input_section
= link_order
->u
.indirect
.section
;
1997 input_bfd
= input_section
->owner
;
1999 BFD_ASSERT (input_section
->output_section
== output_section
);
2000 BFD_ASSERT (input_section
->output_offset
== link_order
->offset
);
2001 BFD_ASSERT (input_section
->_cooked_size
== link_order
->size
);
2003 if (info
->relocateable
2004 && input_section
->reloc_count
> 0
2005 && output_section
->orelocation
== (arelent
**) NULL
)
2007 /* Space has not been allocated for the output relocations.
2008 This can happen when we are called by a specific backend
2009 because somebody is attempting to link together different
2010 types of object files. Handling this case correctly is
2011 difficult, and sometimes impossible. */
2015 /* Get the canonical symbols. The generic linker will always have
2016 retrieved them by this point, but we may be being called by a
2017 specific linker when linking different types of object files
2019 if (bfd_get_outsymbols (input_bfd
) == (asymbol
**) NULL
)
2023 symsize
= get_symtab_upper_bound (input_bfd
);
2024 input_bfd
->outsymbols
= (asymbol
**) bfd_alloc (input_bfd
, symsize
);
2025 if (!input_bfd
->outsymbols
)
2027 bfd_set_error (bfd_error_no_memory
);
2030 input_bfd
->symcount
= bfd_canonicalize_symtab (input_bfd
,
2031 input_bfd
->outsymbols
);
2034 /* Get and relocate the section contents. */
2035 contents
= (bfd_byte
*) alloca (bfd_section_size (input_bfd
, input_section
));
2036 contents
= (bfd_get_relocated_section_contents
2037 (output_bfd
, info
, link_order
, contents
, info
->relocateable
,
2038 bfd_get_outsymbols (input_bfd
)));
2042 /* Output the section contents. */
2043 if (! bfd_set_section_contents (output_bfd
, output_section
, (PTR
) contents
,
2044 link_order
->offset
, link_order
->size
))