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1 /* linker.c -- BFD linker routines
2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
3 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support
6
7 This file is part of BFD, the Binary File Descriptor library.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 MA 02110-1301, USA. */
23
24 #include "sysdep.h"
25 #include "bfd.h"
26 #include "libbfd.h"
27 #include "bfdlink.h"
28 #include "genlink.h"
29
30 /*
31 SECTION
32 Linker Functions
33
34 @cindex Linker
35 The linker uses three special entry points in the BFD target
36 vector. It is not necessary to write special routines for
37 these entry points when creating a new BFD back end, since
38 generic versions are provided. However, writing them can
39 speed up linking and make it use significantly less runtime
40 memory.
41
42 The first routine creates a hash table used by the other
43 routines. The second routine adds the symbols from an object
44 file to the hash table. The third routine takes all the
45 object files and links them together to create the output
46 file. These routines are designed so that the linker proper
47 does not need to know anything about the symbols in the object
48 files that it is linking. The linker merely arranges the
49 sections as directed by the linker script and lets BFD handle
50 the details of symbols and relocs.
51
52 The second routine and third routines are passed a pointer to
53 a <<struct bfd_link_info>> structure (defined in
54 <<bfdlink.h>>) which holds information relevant to the link,
55 including the linker hash table (which was created by the
56 first routine) and a set of callback functions to the linker
57 proper.
58
59 The generic linker routines are in <<linker.c>>, and use the
60 header file <<genlink.h>>. As of this writing, the only back
61 ends which have implemented versions of these routines are
62 a.out (in <<aoutx.h>>) and ECOFF (in <<ecoff.c>>). The a.out
63 routines are used as examples throughout this section.
64
65 @menu
66 @* Creating a Linker Hash Table::
67 @* Adding Symbols to the Hash Table::
68 @* Performing the Final Link::
69 @end menu
70
71 INODE
72 Creating a Linker Hash Table, Adding Symbols to the Hash Table, Linker Functions, Linker Functions
73 SUBSECTION
74 Creating a linker hash table
75
76 @cindex _bfd_link_hash_table_create in target vector
77 @cindex target vector (_bfd_link_hash_table_create)
78 The linker routines must create a hash table, which must be
79 derived from <<struct bfd_link_hash_table>> described in
80 <<bfdlink.c>>. @xref{Hash Tables}, for information on how to
81 create a derived hash table. This entry point is called using
82 the target vector of the linker output file.
83
84 The <<_bfd_link_hash_table_create>> entry point must allocate
85 and initialize an instance of the desired hash table. If the
86 back end does not require any additional information to be
87 stored with the entries in the hash table, the entry point may
88 simply create a <<struct bfd_link_hash_table>>. Most likely,
89 however, some additional information will be needed.
90
91 For example, with each entry in the hash table the a.out
92 linker keeps the index the symbol has in the final output file
93 (this index number is used so that when doing a relocatable
94 link the symbol index used in the output file can be quickly
95 filled in when copying over a reloc). The a.out linker code
96 defines the required structures and functions for a hash table
97 derived from <<struct bfd_link_hash_table>>. The a.out linker
98 hash table is created by the function
99 <<NAME(aout,link_hash_table_create)>>; it simply allocates
100 space for the hash table, initializes it, and returns a
101 pointer to it.
102
103 When writing the linker routines for a new back end, you will
104 generally not know exactly which fields will be required until
105 you have finished. You should simply create a new hash table
106 which defines no additional fields, and then simply add fields
107 as they become necessary.
108
109 INODE
110 Adding Symbols to the Hash Table, Performing the Final Link, Creating a Linker Hash Table, Linker Functions
111 SUBSECTION
112 Adding symbols to the hash table
113
114 @cindex _bfd_link_add_symbols in target vector
115 @cindex target vector (_bfd_link_add_symbols)
116 The linker proper will call the <<_bfd_link_add_symbols>>
117 entry point for each object file or archive which is to be
118 linked (typically these are the files named on the command
119 line, but some may also come from the linker script). The
120 entry point is responsible for examining the file. For an
121 object file, BFD must add any relevant symbol information to
122 the hash table. For an archive, BFD must determine which
123 elements of the archive should be used and adding them to the
124 link.
125
126 The a.out version of this entry point is
127 <<NAME(aout,link_add_symbols)>>.
128
129 @menu
130 @* Differing file formats::
131 @* Adding symbols from an object file::
132 @* Adding symbols from an archive::
133 @end menu
134
135 INODE
136 Differing file formats, Adding symbols from an object file, Adding Symbols to the Hash Table, Adding Symbols to the Hash Table
137 SUBSUBSECTION
138 Differing file formats
139
140 Normally all the files involved in a link will be of the same
141 format, but it is also possible to link together different
142 format object files, and the back end must support that. The
143 <<_bfd_link_add_symbols>> entry point is called via the target
144 vector of the file to be added. This has an important
145 consequence: the function may not assume that the hash table
146 is the type created by the corresponding
147 <<_bfd_link_hash_table_create>> vector. All the
148 <<_bfd_link_add_symbols>> function can assume about the hash
149 table is that it is derived from <<struct
150 bfd_link_hash_table>>.
151
152 Sometimes the <<_bfd_link_add_symbols>> function must store
153 some information in the hash table entry to be used by the
154 <<_bfd_final_link>> function. In such a case the output bfd
155 xvec must be checked to make sure that the hash table was
156 created by an object file of the same format.
157
158 The <<_bfd_final_link>> routine must be prepared to handle a
159 hash entry without any extra information added by the
160 <<_bfd_link_add_symbols>> function. A hash entry without
161 extra information will also occur when the linker script
162 directs the linker to create a symbol. Note that, regardless
163 of how a hash table entry is added, all the fields will be
164 initialized to some sort of null value by the hash table entry
165 initialization function.
166
167 See <<ecoff_link_add_externals>> for an example of how to
168 check the output bfd before saving information (in this
169 case, the ECOFF external symbol debugging information) in a
170 hash table entry.
171
172 INODE
173 Adding symbols from an object file, Adding symbols from an archive, Differing file formats, Adding Symbols to the Hash Table
174 SUBSUBSECTION
175 Adding symbols from an object file
176
177 When the <<_bfd_link_add_symbols>> routine is passed an object
178 file, it must add all externally visible symbols in that
179 object file to the hash table. The actual work of adding the
180 symbol to the hash table is normally handled by the function
181 <<_bfd_generic_link_add_one_symbol>>. The
182 <<_bfd_link_add_symbols>> routine is responsible for reading
183 all the symbols from the object file and passing the correct
184 information to <<_bfd_generic_link_add_one_symbol>>.
185
186 The <<_bfd_link_add_symbols>> routine should not use
187 <<bfd_canonicalize_symtab>> to read the symbols. The point of
188 providing this routine is to avoid the overhead of converting
189 the symbols into generic <<asymbol>> structures.
190
191 @findex _bfd_generic_link_add_one_symbol
192 <<_bfd_generic_link_add_one_symbol>> handles the details of
193 combining common symbols, warning about multiple definitions,
194 and so forth. It takes arguments which describe the symbol to
195 add, notably symbol flags, a section, and an offset. The
196 symbol flags include such things as <<BSF_WEAK>> or
197 <<BSF_INDIRECT>>. The section is a section in the object
198 file, or something like <<bfd_und_section_ptr>> for an undefined
199 symbol or <<bfd_com_section_ptr>> for a common symbol.
200
201 If the <<_bfd_final_link>> routine is also going to need to
202 read the symbol information, the <<_bfd_link_add_symbols>>
203 routine should save it somewhere attached to the object file
204 BFD. However, the information should only be saved if the
205 <<keep_memory>> field of the <<info>> argument is TRUE, so
206 that the <<-no-keep-memory>> linker switch is effective.
207
208 The a.out function which adds symbols from an object file is
209 <<aout_link_add_object_symbols>>, and most of the interesting
210 work is in <<aout_link_add_symbols>>. The latter saves
211 pointers to the hash tables entries created by
212 <<_bfd_generic_link_add_one_symbol>> indexed by symbol number,
213 so that the <<_bfd_final_link>> routine does not have to call
214 the hash table lookup routine to locate the entry.
215
216 INODE
217 Adding symbols from an archive, , Adding symbols from an object file, Adding Symbols to the Hash Table
218 SUBSUBSECTION
219 Adding symbols from an archive
220
221 When the <<_bfd_link_add_symbols>> routine is passed an
222 archive, it must look through the symbols defined by the
223 archive and decide which elements of the archive should be
224 included in the link. For each such element it must call the
225 <<add_archive_element>> linker callback, and it must add the
226 symbols from the object file to the linker hash table. (The
227 callback may in fact indicate that a replacement BFD should be
228 used, in which case the symbols from that BFD should be added
229 to the linker hash table instead.)
230
231 @findex _bfd_generic_link_add_archive_symbols
232 In most cases the work of looking through the symbols in the
233 archive should be done by the
234 <<_bfd_generic_link_add_archive_symbols>> function. This
235 function builds a hash table from the archive symbol table and
236 looks through the list of undefined symbols to see which
237 elements should be included.
238 <<_bfd_generic_link_add_archive_symbols>> is passed a function
239 to call to make the final decision about adding an archive
240 element to the link and to do the actual work of adding the
241 symbols to the linker hash table.
242
243 The function passed to
244 <<_bfd_generic_link_add_archive_symbols>> must read the
245 symbols of the archive element and decide whether the archive
246 element should be included in the link. If the element is to
247 be included, the <<add_archive_element>> linker callback
248 routine must be called with the element as an argument, and
249 the element's symbols must be added to the linker hash table
250 just as though the element had itself been passed to the
251 <<_bfd_link_add_symbols>> function. The <<add_archive_element>>
252 callback has the option to indicate that it would like to
253 replace the element archive with a substitute BFD, in which
254 case it is the symbols of that substitute BFD that must be
255 added to the linker hash table instead.
256
257 When the a.out <<_bfd_link_add_symbols>> function receives an
258 archive, it calls <<_bfd_generic_link_add_archive_symbols>>
259 passing <<aout_link_check_archive_element>> as the function
260 argument. <<aout_link_check_archive_element>> calls
261 <<aout_link_check_ar_symbols>>. If the latter decides to add
262 the element (an element is only added if it provides a real,
263 non-common, definition for a previously undefined or common
264 symbol) it calls the <<add_archive_element>> callback and then
265 <<aout_link_check_archive_element>> calls
266 <<aout_link_add_symbols>> to actually add the symbols to the
267 linker hash table - possibly those of a substitute BFD, if the
268 <<add_archive_element>> callback avails itself of that option.
269
270 The ECOFF back end is unusual in that it does not normally
271 call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF
272 archives already contain a hash table of symbols. The ECOFF
273 back end searches the archive itself to avoid the overhead of
274 creating a new hash table.
275
276 INODE
277 Performing the Final Link, , Adding Symbols to the Hash Table, Linker Functions
278 SUBSECTION
279 Performing the final link
280
281 @cindex _bfd_link_final_link in target vector
282 @cindex target vector (_bfd_final_link)
283 When all the input files have been processed, the linker calls
284 the <<_bfd_final_link>> entry point of the output BFD. This
285 routine is responsible for producing the final output file,
286 which has several aspects. It must relocate the contents of
287 the input sections and copy the data into the output sections.
288 It must build an output symbol table including any local
289 symbols from the input files and the global symbols from the
290 hash table. When producing relocatable output, it must
291 modify the input relocs and write them into the output file.
292 There may also be object format dependent work to be done.
293
294 The linker will also call the <<write_object_contents>> entry
295 point when the BFD is closed. The two entry points must work
296 together in order to produce the correct output file.
297
298 The details of how this works are inevitably dependent upon
299 the specific object file format. The a.out
300 <<_bfd_final_link>> routine is <<NAME(aout,final_link)>>.
301
302 @menu
303 @* Information provided by the linker::
304 @* Relocating the section contents::
305 @* Writing the symbol table::
306 @end menu
307
308 INODE
309 Information provided by the linker, Relocating the section contents, Performing the Final Link, Performing the Final Link
310 SUBSUBSECTION
311 Information provided by the linker
312
313 Before the linker calls the <<_bfd_final_link>> entry point,
314 it sets up some data structures for the function to use.
315
316 The <<input_bfds>> field of the <<bfd_link_info>> structure
317 will point to a list of all the input files included in the
318 link. These files are linked through the <<link_next>> field
319 of the <<bfd>> structure.
320
321 Each section in the output file will have a list of
322 <<link_order>> structures attached to the <<map_head.link_order>>
323 field (the <<link_order>> structure is defined in
324 <<bfdlink.h>>). These structures describe how to create the
325 contents of the output section in terms of the contents of
326 various input sections, fill constants, and, eventually, other
327 types of information. They also describe relocs that must be
328 created by the BFD backend, but do not correspond to any input
329 file; this is used to support -Ur, which builds constructors
330 while generating a relocatable object file.
331
332 INODE
333 Relocating the section contents, Writing the symbol table, Information provided by the linker, Performing the Final Link
334 SUBSUBSECTION
335 Relocating the section contents
336
337 The <<_bfd_final_link>> function should look through the
338 <<link_order>> structures attached to each section of the
339 output file. Each <<link_order>> structure should either be
340 handled specially, or it should be passed to the function
341 <<_bfd_default_link_order>> which will do the right thing
342 (<<_bfd_default_link_order>> is defined in <<linker.c>>).
343
344 For efficiency, a <<link_order>> of type
345 <<bfd_indirect_link_order>> whose associated section belongs
346 to a BFD of the same format as the output BFD must be handled
347 specially. This type of <<link_order>> describes part of an
348 output section in terms of a section belonging to one of the
349 input files. The <<_bfd_final_link>> function should read the
350 contents of the section and any associated relocs, apply the
351 relocs to the section contents, and write out the modified
352 section contents. If performing a relocatable link, the
353 relocs themselves must also be modified and written out.
354
355 @findex _bfd_relocate_contents
356 @findex _bfd_final_link_relocate
357 The functions <<_bfd_relocate_contents>> and
358 <<_bfd_final_link_relocate>> provide some general support for
359 performing the actual relocations, notably overflow checking.
360 Their arguments include information about the symbol the
361 relocation is against and a <<reloc_howto_type>> argument
362 which describes the relocation to perform. These functions
363 are defined in <<reloc.c>>.
364
365 The a.out function which handles reading, relocating, and
366 writing section contents is <<aout_link_input_section>>. The
367 actual relocation is done in <<aout_link_input_section_std>>
368 and <<aout_link_input_section_ext>>.
369
370 INODE
371 Writing the symbol table, , Relocating the section contents, Performing the Final Link
372 SUBSUBSECTION
373 Writing the symbol table
374
375 The <<_bfd_final_link>> function must gather all the symbols
376 in the input files and write them out. It must also write out
377 all the symbols in the global hash table. This must be
378 controlled by the <<strip>> and <<discard>> fields of the
379 <<bfd_link_info>> structure.
380
381 The local symbols of the input files will not have been
382 entered into the linker hash table. The <<_bfd_final_link>>
383 routine must consider each input file and include the symbols
384 in the output file. It may be convenient to do this when
385 looking through the <<link_order>> structures, or it may be
386 done by stepping through the <<input_bfds>> list.
387
388 The <<_bfd_final_link>> routine must also traverse the global
389 hash table to gather all the externally visible symbols. It
390 is possible that most of the externally visible symbols may be
391 written out when considering the symbols of each input file,
392 but it is still necessary to traverse the hash table since the
393 linker script may have defined some symbols that are not in
394 any of the input files.
395
396 The <<strip>> field of the <<bfd_link_info>> structure
397 controls which symbols are written out. The possible values
398 are listed in <<bfdlink.h>>. If the value is <<strip_some>>,
399 then the <<keep_hash>> field of the <<bfd_link_info>>
400 structure is a hash table of symbols to keep; each symbol
401 should be looked up in this hash table, and only symbols which
402 are present should be included in the output file.
403
404 If the <<strip>> field of the <<bfd_link_info>> structure
405 permits local symbols to be written out, the <<discard>> field
406 is used to further controls which local symbols are included
407 in the output file. If the value is <<discard_l>>, then all
408 local symbols which begin with a certain prefix are discarded;
409 this is controlled by the <<bfd_is_local_label_name>> entry point.
410
411 The a.out backend handles symbols by calling
412 <<aout_link_write_symbols>> on each input BFD and then
413 traversing the global hash table with the function
414 <<aout_link_write_other_symbol>>. It builds a string table
415 while writing out the symbols, which is written to the output
416 file at the end of <<NAME(aout,final_link)>>.
417 */
418
419 static bfd_boolean generic_link_add_object_symbols
420 (bfd *, struct bfd_link_info *, bfd_boolean collect);
421 static bfd_boolean generic_link_add_symbols
422 (bfd *, struct bfd_link_info *, bfd_boolean);
423 static bfd_boolean generic_link_check_archive_element_no_collect
424 (bfd *, struct bfd_link_info *, bfd_boolean *);
425 static bfd_boolean generic_link_check_archive_element_collect
426 (bfd *, struct bfd_link_info *, bfd_boolean *);
427 static bfd_boolean generic_link_check_archive_element
428 (bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean);
429 static bfd_boolean generic_link_add_symbol_list
430 (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **,
431 bfd_boolean);
432 static bfd_boolean generic_add_output_symbol
433 (bfd *, size_t *psymalloc, asymbol *);
434 static bfd_boolean default_data_link_order
435 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *);
436 static bfd_boolean default_indirect_link_order
437 (bfd *, struct bfd_link_info *, asection *, struct bfd_link_order *,
438 bfd_boolean);
439
440 /* The link hash table structure is defined in bfdlink.h. It provides
441 a base hash table which the backend specific hash tables are built
442 upon. */
443
444 /* Routine to create an entry in the link hash table. */
445
446 struct bfd_hash_entry *
447 _bfd_link_hash_newfunc (struct bfd_hash_entry *entry,
448 struct bfd_hash_table *table,
449 const char *string)
450 {
451 /* Allocate the structure if it has not already been allocated by a
452 subclass. */
453 if (entry == NULL)
454 {
455 entry = (struct bfd_hash_entry *)
456 bfd_hash_allocate (table, sizeof (struct bfd_link_hash_entry));
457 if (entry == NULL)
458 return entry;
459 }
460
461 /* Call the allocation method of the superclass. */
462 entry = bfd_hash_newfunc (entry, table, string);
463 if (entry)
464 {
465 struct bfd_link_hash_entry *h = (struct bfd_link_hash_entry *) entry;
466
467 /* Initialize the local fields. */
468 h->type = bfd_link_hash_new;
469 memset (&h->u.undef.next, 0,
470 (sizeof (struct bfd_link_hash_entry)
471 - offsetof (struct bfd_link_hash_entry, u.undef.next)));
472 }
473
474 return entry;
475 }
476
477 /* Initialize a link hash table. The BFD argument is the one
478 responsible for creating this table. */
479
480 bfd_boolean
481 _bfd_link_hash_table_init
482 (struct bfd_link_hash_table *table,
483 bfd *abfd ATTRIBUTE_UNUSED,
484 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
485 struct bfd_hash_table *,
486 const char *),
487 unsigned int entsize)
488 {
489 table->undefs = NULL;
490 table->undefs_tail = NULL;
491 table->type = bfd_link_generic_hash_table;
492
493 return bfd_hash_table_init (&table->table, newfunc, entsize);
494 }
495
496 /* Look up a symbol in a link hash table. If follow is TRUE, we
497 follow bfd_link_hash_indirect and bfd_link_hash_warning links to
498 the real symbol. */
499
500 struct bfd_link_hash_entry *
501 bfd_link_hash_lookup (struct bfd_link_hash_table *table,
502 const char *string,
503 bfd_boolean create,
504 bfd_boolean copy,
505 bfd_boolean follow)
506 {
507 struct bfd_link_hash_entry *ret;
508
509 ret = ((struct bfd_link_hash_entry *)
510 bfd_hash_lookup (&table->table, string, create, copy));
511
512 if (follow && ret != NULL)
513 {
514 while (ret->type == bfd_link_hash_indirect
515 || ret->type == bfd_link_hash_warning)
516 ret = ret->u.i.link;
517 }
518
519 return ret;
520 }
521
522 /* Look up a symbol in the main linker hash table if the symbol might
523 be wrapped. This should only be used for references to an
524 undefined symbol, not for definitions of a symbol. */
525
526 struct bfd_link_hash_entry *
527 bfd_wrapped_link_hash_lookup (bfd *abfd,
528 struct bfd_link_info *info,
529 const char *string,
530 bfd_boolean create,
531 bfd_boolean copy,
532 bfd_boolean follow)
533 {
534 bfd_size_type amt;
535
536 if (info->wrap_hash != NULL)
537 {
538 const char *l;
539 char prefix = '\0';
540
541 l = string;
542 if (*l == bfd_get_symbol_leading_char (abfd) || *l == info->wrap_char)
543 {
544 prefix = *l;
545 ++l;
546 }
547
548 #undef WRAP
549 #define WRAP "__wrap_"
550
551 if (bfd_hash_lookup (info->wrap_hash, l, FALSE, FALSE) != NULL)
552 {
553 char *n;
554 struct bfd_link_hash_entry *h;
555
556 /* This symbol is being wrapped. We want to replace all
557 references to SYM with references to __wrap_SYM. */
558
559 amt = strlen (l) + sizeof WRAP + 1;
560 n = (char *) bfd_malloc (amt);
561 if (n == NULL)
562 return NULL;
563
564 n[0] = prefix;
565 n[1] = '\0';
566 strcat (n, WRAP);
567 strcat (n, l);
568 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow);
569 free (n);
570 return h;
571 }
572
573 #undef WRAP
574
575 #undef REAL
576 #define REAL "__real_"
577
578 if (*l == '_'
579 && CONST_STRNEQ (l, REAL)
580 && bfd_hash_lookup (info->wrap_hash, l + sizeof REAL - 1,
581 FALSE, FALSE) != NULL)
582 {
583 char *n;
584 struct bfd_link_hash_entry *h;
585
586 /* This is a reference to __real_SYM, where SYM is being
587 wrapped. We want to replace all references to __real_SYM
588 with references to SYM. */
589
590 amt = strlen (l + sizeof REAL - 1) + 2;
591 n = (char *) bfd_malloc (amt);
592 if (n == NULL)
593 return NULL;
594
595 n[0] = prefix;
596 n[1] = '\0';
597 strcat (n, l + sizeof REAL - 1);
598 h = bfd_link_hash_lookup (info->hash, n, create, TRUE, follow);
599 free (n);
600 return h;
601 }
602
603 #undef REAL
604 }
605
606 return bfd_link_hash_lookup (info->hash, string, create, copy, follow);
607 }
608
609 /* Traverse a generic link hash table. The only reason this is not a
610 macro is to do better type checking. This code presumes that an
611 argument passed as a struct bfd_hash_entry * may be caught as a
612 struct bfd_link_hash_entry * with no explicit cast required on the
613 call. */
614
615 void
616 bfd_link_hash_traverse
617 (struct bfd_link_hash_table *table,
618 bfd_boolean (*func) (struct bfd_link_hash_entry *, void *),
619 void *info)
620 {
621 bfd_hash_traverse (&table->table,
622 (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func,
623 info);
624 }
625
626 /* Add a symbol to the linker hash table undefs list. */
627
628 void
629 bfd_link_add_undef (struct bfd_link_hash_table *table,
630 struct bfd_link_hash_entry *h)
631 {
632 BFD_ASSERT (h->u.undef.next == NULL);
633 if (table->undefs_tail != NULL)
634 table->undefs_tail->u.undef.next = h;
635 if (table->undefs == NULL)
636 table->undefs = h;
637 table->undefs_tail = h;
638 }
639
640 /* The undefs list was designed so that in normal use we don't need to
641 remove entries. However, if symbols on the list are changed from
642 bfd_link_hash_undefined to either bfd_link_hash_undefweak or
643 bfd_link_hash_new for some reason, then they must be removed from the
644 list. Failure to do so might result in the linker attempting to add
645 the symbol to the list again at a later stage. */
646
647 void
648 bfd_link_repair_undef_list (struct bfd_link_hash_table *table)
649 {
650 struct bfd_link_hash_entry **pun;
651
652 pun = &table->undefs;
653 while (*pun != NULL)
654 {
655 struct bfd_link_hash_entry *h = *pun;
656
657 if (h->type == bfd_link_hash_new
658 || h->type == bfd_link_hash_undefweak)
659 {
660 *pun = h->u.undef.next;
661 h->u.undef.next = NULL;
662 if (h == table->undefs_tail)
663 {
664 if (pun == &table->undefs)
665 table->undefs_tail = NULL;
666 else
667 /* pun points at an u.undef.next field. Go back to
668 the start of the link_hash_entry. */
669 table->undefs_tail = (struct bfd_link_hash_entry *)
670 ((char *) pun - ((char *) &h->u.undef.next - (char *) h));
671 break;
672 }
673 }
674 else
675 pun = &h->u.undef.next;
676 }
677 }
678 \f
679 /* Routine to create an entry in a generic link hash table. */
680
681 struct bfd_hash_entry *
682 _bfd_generic_link_hash_newfunc (struct bfd_hash_entry *entry,
683 struct bfd_hash_table *table,
684 const char *string)
685 {
686 /* Allocate the structure if it has not already been allocated by a
687 subclass. */
688 if (entry == NULL)
689 {
690 entry = (struct bfd_hash_entry *)
691 bfd_hash_allocate (table, sizeof (struct generic_link_hash_entry));
692 if (entry == NULL)
693 return entry;
694 }
695
696 /* Call the allocation method of the superclass. */
697 entry = _bfd_link_hash_newfunc (entry, table, string);
698 if (entry)
699 {
700 struct generic_link_hash_entry *ret;
701
702 /* Set local fields. */
703 ret = (struct generic_link_hash_entry *) entry;
704 ret->written = FALSE;
705 ret->sym = NULL;
706 }
707
708 return entry;
709 }
710
711 /* Create a generic link hash table. */
712
713 struct bfd_link_hash_table *
714 _bfd_generic_link_hash_table_create (bfd *abfd)
715 {
716 struct generic_link_hash_table *ret;
717 bfd_size_type amt = sizeof (struct generic_link_hash_table);
718
719 ret = (struct generic_link_hash_table *) bfd_malloc (amt);
720 if (ret == NULL)
721 return NULL;
722 if (! _bfd_link_hash_table_init (&ret->root, abfd,
723 _bfd_generic_link_hash_newfunc,
724 sizeof (struct generic_link_hash_entry)))
725 {
726 free (ret);
727 return NULL;
728 }
729 return &ret->root;
730 }
731
732 void
733 _bfd_generic_link_hash_table_free (struct bfd_link_hash_table *hash)
734 {
735 struct generic_link_hash_table *ret
736 = (struct generic_link_hash_table *) hash;
737
738 bfd_hash_table_free (&ret->root.table);
739 free (ret);
740 }
741
742 /* Grab the symbols for an object file when doing a generic link. We
743 store the symbols in the outsymbols field. We need to keep them
744 around for the entire link to ensure that we only read them once.
745 If we read them multiple times, we might wind up with relocs and
746 the hash table pointing to different instances of the symbol
747 structure. */
748
749 bfd_boolean
750 bfd_generic_link_read_symbols (bfd *abfd)
751 {
752 if (bfd_get_outsymbols (abfd) == NULL)
753 {
754 long symsize;
755 long symcount;
756
757 symsize = bfd_get_symtab_upper_bound (abfd);
758 if (symsize < 0)
759 return FALSE;
760 bfd_get_outsymbols (abfd) = (struct bfd_symbol **) bfd_alloc (abfd,
761 symsize);
762 if (bfd_get_outsymbols (abfd) == NULL && symsize != 0)
763 return FALSE;
764 symcount = bfd_canonicalize_symtab (abfd, bfd_get_outsymbols (abfd));
765 if (symcount < 0)
766 return FALSE;
767 bfd_get_symcount (abfd) = symcount;
768 }
769
770 return TRUE;
771 }
772 \f
773 /* Generic function to add symbols to from an object file to the
774 global hash table. This version does not automatically collect
775 constructors by name. */
776
777 bfd_boolean
778 _bfd_generic_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
779 {
780 return generic_link_add_symbols (abfd, info, FALSE);
781 }
782
783 /* Generic function to add symbols from an object file to the global
784 hash table. This version automatically collects constructors by
785 name, as the collect2 program does. It should be used for any
786 target which does not provide some other mechanism for setting up
787 constructors and destructors; these are approximately those targets
788 for which gcc uses collect2 and do not support stabs. */
789
790 bfd_boolean
791 _bfd_generic_link_add_symbols_collect (bfd *abfd, struct bfd_link_info *info)
792 {
793 return generic_link_add_symbols (abfd, info, TRUE);
794 }
795
796 /* Indicate that we are only retrieving symbol values from this
797 section. We want the symbols to act as though the values in the
798 file are absolute. */
799
800 void
801 _bfd_generic_link_just_syms (asection *sec,
802 struct bfd_link_info *info ATTRIBUTE_UNUSED)
803 {
804 sec->output_section = bfd_abs_section_ptr;
805 sec->output_offset = sec->vma;
806 }
807
808 /* Copy the type of a symbol assiciated with a linker hast table entry.
809 Override this so that symbols created in linker scripts get their
810 type from the RHS of the assignment.
811 The default implementation does nothing. */
812 void
813 _bfd_generic_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED,
814 struct bfd_link_hash_entry * hdest ATTRIBUTE_UNUSED,
815 struct bfd_link_hash_entry * hsrc ATTRIBUTE_UNUSED)
816 {
817 }
818
819 /* Add symbols from an object file to the global hash table. */
820
821 static bfd_boolean
822 generic_link_add_symbols (bfd *abfd,
823 struct bfd_link_info *info,
824 bfd_boolean collect)
825 {
826 bfd_boolean ret;
827
828 switch (bfd_get_format (abfd))
829 {
830 case bfd_object:
831 ret = generic_link_add_object_symbols (abfd, info, collect);
832 break;
833 case bfd_archive:
834 ret = (_bfd_generic_link_add_archive_symbols
835 (abfd, info,
836 (collect
837 ? generic_link_check_archive_element_collect
838 : generic_link_check_archive_element_no_collect)));
839 break;
840 default:
841 bfd_set_error (bfd_error_wrong_format);
842 ret = FALSE;
843 }
844
845 return ret;
846 }
847
848 /* Add symbols from an object file to the global hash table. */
849
850 static bfd_boolean
851 generic_link_add_object_symbols (bfd *abfd,
852 struct bfd_link_info *info,
853 bfd_boolean collect)
854 {
855 bfd_size_type symcount;
856 struct bfd_symbol **outsyms;
857
858 if (!bfd_generic_link_read_symbols (abfd))
859 return FALSE;
860 symcount = _bfd_generic_link_get_symcount (abfd);
861 outsyms = _bfd_generic_link_get_symbols (abfd);
862 return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect);
863 }
864 \f
865 /* We build a hash table of all symbols defined in an archive. */
866
867 /* An archive symbol may be defined by multiple archive elements.
868 This linked list is used to hold the elements. */
869
870 struct archive_list
871 {
872 struct archive_list *next;
873 unsigned int indx;
874 };
875
876 /* An entry in an archive hash table. */
877
878 struct archive_hash_entry
879 {
880 struct bfd_hash_entry root;
881 /* Where the symbol is defined. */
882 struct archive_list *defs;
883 };
884
885 /* An archive hash table itself. */
886
887 struct archive_hash_table
888 {
889 struct bfd_hash_table table;
890 };
891
892 /* Create a new entry for an archive hash table. */
893
894 static struct bfd_hash_entry *
895 archive_hash_newfunc (struct bfd_hash_entry *entry,
896 struct bfd_hash_table *table,
897 const char *string)
898 {
899 struct archive_hash_entry *ret = (struct archive_hash_entry *) entry;
900
901 /* Allocate the structure if it has not already been allocated by a
902 subclass. */
903 if (ret == NULL)
904 ret = (struct archive_hash_entry *)
905 bfd_hash_allocate (table, sizeof (struct archive_hash_entry));
906 if (ret == NULL)
907 return NULL;
908
909 /* Call the allocation method of the superclass. */
910 ret = ((struct archive_hash_entry *)
911 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
912
913 if (ret)
914 {
915 /* Initialize the local fields. */
916 ret->defs = NULL;
917 }
918
919 return &ret->root;
920 }
921
922 /* Initialize an archive hash table. */
923
924 static bfd_boolean
925 archive_hash_table_init
926 (struct archive_hash_table *table,
927 struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
928 struct bfd_hash_table *,
929 const char *),
930 unsigned int entsize)
931 {
932 return bfd_hash_table_init (&table->table, newfunc, entsize);
933 }
934
935 /* Look up an entry in an archive hash table. */
936
937 #define archive_hash_lookup(t, string, create, copy) \
938 ((struct archive_hash_entry *) \
939 bfd_hash_lookup (&(t)->table, (string), (create), (copy)))
940
941 /* Allocate space in an archive hash table. */
942
943 #define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size))
944
945 /* Free an archive hash table. */
946
947 #define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table)
948
949 /* Generic function to add symbols from an archive file to the global
950 hash file. This function presumes that the archive symbol table
951 has already been read in (this is normally done by the
952 bfd_check_format entry point). It looks through the undefined and
953 common symbols and searches the archive symbol table for them. If
954 it finds an entry, it includes the associated object file in the
955 link.
956
957 The old linker looked through the archive symbol table for
958 undefined symbols. We do it the other way around, looking through
959 undefined symbols for symbols defined in the archive. The
960 advantage of the newer scheme is that we only have to look through
961 the list of undefined symbols once, whereas the old method had to
962 re-search the symbol table each time a new object file was added.
963
964 The CHECKFN argument is used to see if an object file should be
965 included. CHECKFN should set *PNEEDED to TRUE if the object file
966 should be included, and must also call the bfd_link_info
967 add_archive_element callback function and handle adding the symbols
968 to the global hash table. CHECKFN must notice if the callback
969 indicates a substitute BFD, and arrange to add those symbols instead
970 if it does so. CHECKFN should only return FALSE if some sort of
971 error occurs.
972
973 For some formats, such as a.out, it is possible to look through an
974 object file but not actually include it in the link. The
975 archive_pass field in a BFD is used to avoid checking the symbols
976 of an object files too many times. When an object is included in
977 the link, archive_pass is set to -1. If an object is scanned but
978 not included, archive_pass is set to the pass number. The pass
979 number is incremented each time a new object file is included. The
980 pass number is used because when a new object file is included it
981 may create new undefined symbols which cause a previously examined
982 object file to be included. */
983
984 bfd_boolean
985 _bfd_generic_link_add_archive_symbols
986 (bfd *abfd,
987 struct bfd_link_info *info,
988 bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *))
989 {
990 carsym *arsyms;
991 carsym *arsym_end;
992 register carsym *arsym;
993 int pass;
994 struct archive_hash_table arsym_hash;
995 unsigned int indx;
996 struct bfd_link_hash_entry **pundef;
997
998 if (! bfd_has_map (abfd))
999 {
1000 /* An empty archive is a special case. */
1001 if (bfd_openr_next_archived_file (abfd, NULL) == NULL)
1002 return TRUE;
1003 bfd_set_error (bfd_error_no_armap);
1004 return FALSE;
1005 }
1006
1007 arsyms = bfd_ardata (abfd)->symdefs;
1008 arsym_end = arsyms + bfd_ardata (abfd)->symdef_count;
1009
1010 /* In order to quickly determine whether an symbol is defined in
1011 this archive, we build a hash table of the symbols. */
1012 if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc,
1013 sizeof (struct archive_hash_entry)))
1014 return FALSE;
1015 for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++)
1016 {
1017 struct archive_hash_entry *arh;
1018 struct archive_list *l, **pp;
1019
1020 arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE);
1021 if (arh == NULL)
1022 goto error_return;
1023 l = ((struct archive_list *)
1024 archive_hash_allocate (&arsym_hash, sizeof (struct archive_list)));
1025 if (l == NULL)
1026 goto error_return;
1027 l->indx = indx;
1028 for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next)
1029 ;
1030 *pp = l;
1031 l->next = NULL;
1032 }
1033
1034 /* The archive_pass field in the archive itself is used to
1035 initialize PASS, sine we may search the same archive multiple
1036 times. */
1037 pass = abfd->archive_pass + 1;
1038
1039 /* New undefined symbols are added to the end of the list, so we
1040 only need to look through it once. */
1041 pundef = &info->hash->undefs;
1042 while (*pundef != NULL)
1043 {
1044 struct bfd_link_hash_entry *h;
1045 struct archive_hash_entry *arh;
1046 struct archive_list *l;
1047
1048 h = *pundef;
1049
1050 /* When a symbol is defined, it is not necessarily removed from
1051 the list. */
1052 if (h->type != bfd_link_hash_undefined
1053 && h->type != bfd_link_hash_common)
1054 {
1055 /* Remove this entry from the list, for general cleanliness
1056 and because we are going to look through the list again
1057 if we search any more libraries. We can't remove the
1058 entry if it is the tail, because that would lose any
1059 entries we add to the list later on (it would also cause
1060 us to lose track of whether the symbol has been
1061 referenced). */
1062 if (*pundef != info->hash->undefs_tail)
1063 *pundef = (*pundef)->u.undef.next;
1064 else
1065 pundef = &(*pundef)->u.undef.next;
1066 continue;
1067 }
1068
1069 /* Look for this symbol in the archive symbol map. */
1070 arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE);
1071 if (arh == NULL)
1072 {
1073 /* If we haven't found the exact symbol we're looking for,
1074 let's look for its import thunk */
1075 if (info->pei386_auto_import)
1076 {
1077 bfd_size_type amt = strlen (h->root.string) + 10;
1078 char *buf = (char *) bfd_malloc (amt);
1079 if (buf == NULL)
1080 return FALSE;
1081
1082 sprintf (buf, "__imp_%s", h->root.string);
1083 arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE);
1084 free(buf);
1085 }
1086 if (arh == NULL)
1087 {
1088 pundef = &(*pundef)->u.undef.next;
1089 continue;
1090 }
1091 }
1092 /* Look at all the objects which define this symbol. */
1093 for (l = arh->defs; l != NULL; l = l->next)
1094 {
1095 bfd *element;
1096 bfd_boolean needed;
1097
1098 /* If the symbol has gotten defined along the way, quit. */
1099 if (h->type != bfd_link_hash_undefined
1100 && h->type != bfd_link_hash_common)
1101 break;
1102
1103 element = bfd_get_elt_at_index (abfd, l->indx);
1104 if (element == NULL)
1105 goto error_return;
1106
1107 /* If we've already included this element, or if we've
1108 already checked it on this pass, continue. */
1109 if (element->archive_pass == -1
1110 || element->archive_pass == pass)
1111 continue;
1112
1113 /* If we can't figure this element out, just ignore it. */
1114 if (! bfd_check_format (element, bfd_object))
1115 {
1116 element->archive_pass = -1;
1117 continue;
1118 }
1119
1120 /* CHECKFN will see if this element should be included, and
1121 go ahead and include it if appropriate. */
1122 if (! (*checkfn) (element, info, &needed))
1123 goto error_return;
1124
1125 if (! needed)
1126 element->archive_pass = pass;
1127 else
1128 {
1129 element->archive_pass = -1;
1130
1131 /* Increment the pass count to show that we may need to
1132 recheck object files which were already checked. */
1133 ++pass;
1134 }
1135 }
1136
1137 pundef = &(*pundef)->u.undef.next;
1138 }
1139
1140 archive_hash_table_free (&arsym_hash);
1141
1142 /* Save PASS in case we are called again. */
1143 abfd->archive_pass = pass;
1144
1145 return TRUE;
1146
1147 error_return:
1148 archive_hash_table_free (&arsym_hash);
1149 return FALSE;
1150 }
1151 \f
1152 /* See if we should include an archive element. This version is used
1153 when we do not want to automatically collect constructors based on
1154 the symbol name, presumably because we have some other mechanism
1155 for finding them. */
1156
1157 static bfd_boolean
1158 generic_link_check_archive_element_no_collect (
1159 bfd *abfd,
1160 struct bfd_link_info *info,
1161 bfd_boolean *pneeded)
1162 {
1163 return generic_link_check_archive_element (abfd, info, pneeded, FALSE);
1164 }
1165
1166 /* See if we should include an archive element. This version is used
1167 when we want to automatically collect constructors based on the
1168 symbol name, as collect2 does. */
1169
1170 static bfd_boolean
1171 generic_link_check_archive_element_collect (bfd *abfd,
1172 struct bfd_link_info *info,
1173 bfd_boolean *pneeded)
1174 {
1175 return generic_link_check_archive_element (abfd, info, pneeded, TRUE);
1176 }
1177
1178 /* See if we should include an archive element. Optionally collect
1179 constructors. */
1180
1181 static bfd_boolean
1182 generic_link_check_archive_element (bfd *abfd,
1183 struct bfd_link_info *info,
1184 bfd_boolean *pneeded,
1185 bfd_boolean collect)
1186 {
1187 asymbol **pp, **ppend;
1188
1189 *pneeded = FALSE;
1190
1191 if (!bfd_generic_link_read_symbols (abfd))
1192 return FALSE;
1193
1194 pp = _bfd_generic_link_get_symbols (abfd);
1195 ppend = pp + _bfd_generic_link_get_symcount (abfd);
1196 for (; pp < ppend; pp++)
1197 {
1198 asymbol *p;
1199 struct bfd_link_hash_entry *h;
1200
1201 p = *pp;
1202
1203 /* We are only interested in globally visible symbols. */
1204 if (! bfd_is_com_section (p->section)
1205 && (p->flags & (BSF_GLOBAL | BSF_INDIRECT | BSF_WEAK)) == 0)
1206 continue;
1207
1208 /* We are only interested if we know something about this
1209 symbol, and it is undefined or common. An undefined weak
1210 symbol (type bfd_link_hash_undefweak) is not considered to be
1211 a reference when pulling files out of an archive. See the
1212 SVR4 ABI, p. 4-27. */
1213 h = bfd_link_hash_lookup (info->hash, bfd_asymbol_name (p), FALSE,
1214 FALSE, TRUE);
1215 if (h == NULL
1216 || (h->type != bfd_link_hash_undefined
1217 && h->type != bfd_link_hash_common))
1218 continue;
1219
1220 /* P is a symbol we are looking for. */
1221
1222 if (! bfd_is_com_section (p->section))
1223 {
1224 bfd_size_type symcount;
1225 asymbol **symbols;
1226 bfd *oldbfd = abfd;
1227
1228 /* This object file defines this symbol, so pull it in. */
1229 if (!(*info->callbacks
1230 ->add_archive_element) (info, abfd, bfd_asymbol_name (p),
1231 &abfd))
1232 return FALSE;
1233 /* Potentially, the add_archive_element hook may have set a
1234 substitute BFD for us. */
1235 if (abfd != oldbfd
1236 && !bfd_generic_link_read_symbols (abfd))
1237 return FALSE;
1238 symcount = _bfd_generic_link_get_symcount (abfd);
1239 symbols = _bfd_generic_link_get_symbols (abfd);
1240 if (! generic_link_add_symbol_list (abfd, info, symcount,
1241 symbols, collect))
1242 return FALSE;
1243 *pneeded = TRUE;
1244 return TRUE;
1245 }
1246
1247 /* P is a common symbol. */
1248
1249 if (h->type == bfd_link_hash_undefined)
1250 {
1251 bfd *symbfd;
1252 bfd_vma size;
1253 unsigned int power;
1254
1255 symbfd = h->u.undef.abfd;
1256 if (symbfd == NULL)
1257 {
1258 /* This symbol was created as undefined from outside
1259 BFD. We assume that we should link in the object
1260 file. This is for the -u option in the linker. */
1261 if (!(*info->callbacks
1262 ->add_archive_element) (info, abfd, bfd_asymbol_name (p),
1263 &abfd))
1264 return FALSE;
1265 /* Potentially, the add_archive_element hook may have set a
1266 substitute BFD for us. But no symbols are going to get
1267 registered by anything we're returning to from here. */
1268 *pneeded = TRUE;
1269 return TRUE;
1270 }
1271
1272 /* Turn the symbol into a common symbol but do not link in
1273 the object file. This is how a.out works. Object
1274 formats that require different semantics must implement
1275 this function differently. This symbol is already on the
1276 undefs list. We add the section to a common section
1277 attached to symbfd to ensure that it is in a BFD which
1278 will be linked in. */
1279 h->type = bfd_link_hash_common;
1280 h->u.c.p = (struct bfd_link_hash_common_entry *)
1281 bfd_hash_allocate (&info->hash->table,
1282 sizeof (struct bfd_link_hash_common_entry));
1283 if (h->u.c.p == NULL)
1284 return FALSE;
1285
1286 size = bfd_asymbol_value (p);
1287 h->u.c.size = size;
1288
1289 power = bfd_log2 (size);
1290 if (power > 4)
1291 power = 4;
1292 h->u.c.p->alignment_power = power;
1293
1294 if (p->section == bfd_com_section_ptr)
1295 h->u.c.p->section = bfd_make_section_old_way (symbfd, "COMMON");
1296 else
1297 h->u.c.p->section = bfd_make_section_old_way (symbfd,
1298 p->section->name);
1299 h->u.c.p->section->flags = SEC_ALLOC;
1300 }
1301 else
1302 {
1303 /* Adjust the size of the common symbol if necessary. This
1304 is how a.out works. Object formats that require
1305 different semantics must implement this function
1306 differently. */
1307 if (bfd_asymbol_value (p) > h->u.c.size)
1308 h->u.c.size = bfd_asymbol_value (p);
1309 }
1310 }
1311
1312 /* This archive element is not needed. */
1313 return TRUE;
1314 }
1315
1316 /* Add the symbols from an object file to the global hash table. ABFD
1317 is the object file. INFO is the linker information. SYMBOL_COUNT
1318 is the number of symbols. SYMBOLS is the list of symbols. COLLECT
1319 is TRUE if constructors should be automatically collected by name
1320 as is done by collect2. */
1321
1322 static bfd_boolean
1323 generic_link_add_symbol_list (bfd *abfd,
1324 struct bfd_link_info *info,
1325 bfd_size_type symbol_count,
1326 asymbol **symbols,
1327 bfd_boolean collect)
1328 {
1329 asymbol **pp, **ppend;
1330
1331 pp = symbols;
1332 ppend = symbols + symbol_count;
1333 for (; pp < ppend; pp++)
1334 {
1335 asymbol *p;
1336
1337 p = *pp;
1338
1339 if ((p->flags & (BSF_INDIRECT
1340 | BSF_WARNING
1341 | BSF_GLOBAL
1342 | BSF_CONSTRUCTOR
1343 | BSF_WEAK)) != 0
1344 || bfd_is_und_section (bfd_get_section (p))
1345 || bfd_is_com_section (bfd_get_section (p))
1346 || bfd_is_ind_section (bfd_get_section (p)))
1347 {
1348 const char *name;
1349 const char *string;
1350 struct generic_link_hash_entry *h;
1351 struct bfd_link_hash_entry *bh;
1352
1353 string = name = bfd_asymbol_name (p);
1354 if (((p->flags & BSF_INDIRECT) != 0
1355 || bfd_is_ind_section (p->section))
1356 && pp + 1 < ppend)
1357 {
1358 pp++;
1359 string = bfd_asymbol_name (*pp);
1360 }
1361 else if ((p->flags & BSF_WARNING) != 0
1362 && pp + 1 < ppend)
1363 {
1364 /* The name of P is actually the warning string, and the
1365 next symbol is the one to warn about. */
1366 pp++;
1367 name = bfd_asymbol_name (*pp);
1368 }
1369
1370 bh = NULL;
1371 if (! (_bfd_generic_link_add_one_symbol
1372 (info, abfd, name, p->flags, bfd_get_section (p),
1373 p->value, string, FALSE, collect, &bh)))
1374 return FALSE;
1375 h = (struct generic_link_hash_entry *) bh;
1376
1377 /* If this is a constructor symbol, and the linker didn't do
1378 anything with it, then we want to just pass the symbol
1379 through to the output file. This will happen when
1380 linking with -r. */
1381 if ((p->flags & BSF_CONSTRUCTOR) != 0
1382 && (h == NULL || h->root.type == bfd_link_hash_new))
1383 {
1384 p->udata.p = NULL;
1385 continue;
1386 }
1387
1388 /* Save the BFD symbol so that we don't lose any backend
1389 specific information that may be attached to it. We only
1390 want this one if it gives more information than the
1391 existing one; we don't want to replace a defined symbol
1392 with an undefined one. This routine may be called with a
1393 hash table other than the generic hash table, so we only
1394 do this if we are certain that the hash table is a
1395 generic one. */
1396 if (info->output_bfd->xvec == abfd->xvec)
1397 {
1398 if (h->sym == NULL
1399 || (! bfd_is_und_section (bfd_get_section (p))
1400 && (! bfd_is_com_section (bfd_get_section (p))
1401 || bfd_is_und_section (bfd_get_section (h->sym)))))
1402 {
1403 h->sym = p;
1404 /* BSF_OLD_COMMON is a hack to support COFF reloc
1405 reading, and it should go away when the COFF
1406 linker is switched to the new version. */
1407 if (bfd_is_com_section (bfd_get_section (p)))
1408 p->flags |= BSF_OLD_COMMON;
1409 }
1410 }
1411
1412 /* Store a back pointer from the symbol to the hash
1413 table entry for the benefit of relaxation code until
1414 it gets rewritten to not use asymbol structures.
1415 Setting this is also used to check whether these
1416 symbols were set up by the generic linker. */
1417 p->udata.p = h;
1418 }
1419 }
1420
1421 return TRUE;
1422 }
1423 \f
1424 /* We use a state table to deal with adding symbols from an object
1425 file. The first index into the state table describes the symbol
1426 from the object file. The second index into the state table is the
1427 type of the symbol in the hash table. */
1428
1429 /* The symbol from the object file is turned into one of these row
1430 values. */
1431
1432 enum link_row
1433 {
1434 UNDEF_ROW, /* Undefined. */
1435 UNDEFW_ROW, /* Weak undefined. */
1436 DEF_ROW, /* Defined. */
1437 DEFW_ROW, /* Weak defined. */
1438 COMMON_ROW, /* Common. */
1439 INDR_ROW, /* Indirect. */
1440 WARN_ROW, /* Warning. */
1441 SET_ROW /* Member of set. */
1442 };
1443
1444 /* apparently needed for Hitachi 3050R(HI-UX/WE2)? */
1445 #undef FAIL
1446
1447 /* The actions to take in the state table. */
1448
1449 enum link_action
1450 {
1451 FAIL, /* Abort. */
1452 UND, /* Mark symbol undefined. */
1453 WEAK, /* Mark symbol weak undefined. */
1454 DEF, /* Mark symbol defined. */
1455 DEFW, /* Mark symbol weak defined. */
1456 COM, /* Mark symbol common. */
1457 REF, /* Mark defined symbol referenced. */
1458 CREF, /* Possibly warn about common reference to defined symbol. */
1459 CDEF, /* Define existing common symbol. */
1460 NOACT, /* No action. */
1461 BIG, /* Mark symbol common using largest size. */
1462 MDEF, /* Multiple definition error. */
1463 MIND, /* Multiple indirect symbols. */
1464 IND, /* Make indirect symbol. */
1465 CIND, /* Make indirect symbol from existing common symbol. */
1466 SET, /* Add value to set. */
1467 MWARN, /* Make warning symbol. */
1468 WARN, /* Issue warning. */
1469 CWARN, /* Warn if referenced, else MWARN. */
1470 CYCLE, /* Repeat with symbol pointed to. */
1471 REFC, /* Mark indirect symbol referenced and then CYCLE. */
1472 WARNC /* Issue warning and then CYCLE. */
1473 };
1474
1475 /* The state table itself. The first index is a link_row and the
1476 second index is a bfd_link_hash_type. */
1477
1478 static const enum link_action link_action[8][8] =
1479 {
1480 /* current\prev new undef undefw def defw com indr warn */
1481 /* UNDEF_ROW */ {UND, NOACT, UND, REF, REF, NOACT, REFC, WARNC },
1482 /* UNDEFW_ROW */ {WEAK, NOACT, NOACT, REF, REF, NOACT, REFC, WARNC },
1483 /* DEF_ROW */ {DEF, DEF, DEF, MDEF, DEF, CDEF, MDEF, CYCLE },
1484 /* DEFW_ROW */ {DEFW, DEFW, DEFW, NOACT, NOACT, NOACT, NOACT, CYCLE },
1485 /* COMMON_ROW */ {COM, COM, COM, CREF, COM, BIG, REFC, WARNC },
1486 /* INDR_ROW */ {IND, IND, IND, MDEF, IND, CIND, MIND, CYCLE },
1487 /* WARN_ROW */ {MWARN, WARN, WARN, CWARN, CWARN, WARN, CWARN, NOACT },
1488 /* SET_ROW */ {SET, SET, SET, SET, SET, SET, CYCLE, CYCLE }
1489 };
1490
1491 /* Most of the entries in the LINK_ACTION table are straightforward,
1492 but a few are somewhat subtle.
1493
1494 A reference to an indirect symbol (UNDEF_ROW/indr or
1495 UNDEFW_ROW/indr) is counted as a reference both to the indirect
1496 symbol and to the symbol the indirect symbol points to.
1497
1498 A reference to a warning symbol (UNDEF_ROW/warn or UNDEFW_ROW/warn)
1499 causes the warning to be issued.
1500
1501 A common definition of an indirect symbol (COMMON_ROW/indr) is
1502 treated as a multiple definition error. Likewise for an indirect
1503 definition of a common symbol (INDR_ROW/com).
1504
1505 An indirect definition of a warning (INDR_ROW/warn) does not cause
1506 the warning to be issued.
1507
1508 If a warning is created for an indirect symbol (WARN_ROW/indr) no
1509 warning is created for the symbol the indirect symbol points to.
1510
1511 Adding an entry to a set does not count as a reference to a set,
1512 and no warning is issued (SET_ROW/warn). */
1513
1514 /* Return the BFD in which a hash entry has been defined, if known. */
1515
1516 static bfd *
1517 hash_entry_bfd (struct bfd_link_hash_entry *h)
1518 {
1519 while (h->type == bfd_link_hash_warning)
1520 h = h->u.i.link;
1521 switch (h->type)
1522 {
1523 default:
1524 return NULL;
1525 case bfd_link_hash_undefined:
1526 case bfd_link_hash_undefweak:
1527 return h->u.undef.abfd;
1528 case bfd_link_hash_defined:
1529 case bfd_link_hash_defweak:
1530 return h->u.def.section->owner;
1531 case bfd_link_hash_common:
1532 return h->u.c.p->section->owner;
1533 }
1534 /*NOTREACHED*/
1535 }
1536
1537 /* Add a symbol to the global hash table.
1538 ABFD is the BFD the symbol comes from.
1539 NAME is the name of the symbol.
1540 FLAGS is the BSF_* bits associated with the symbol.
1541 SECTION is the section in which the symbol is defined; this may be
1542 bfd_und_section_ptr or bfd_com_section_ptr.
1543 VALUE is the value of the symbol, relative to the section.
1544 STRING is used for either an indirect symbol, in which case it is
1545 the name of the symbol to indirect to, or a warning symbol, in
1546 which case it is the warning string.
1547 COPY is TRUE if NAME or STRING must be copied into locally
1548 allocated memory if they need to be saved.
1549 COLLECT is TRUE if we should automatically collect gcc constructor
1550 or destructor names as collect2 does.
1551 HASHP, if not NULL, is a place to store the created hash table
1552 entry; if *HASHP is not NULL, the caller has already looked up
1553 the hash table entry, and stored it in *HASHP. */
1554
1555 bfd_boolean
1556 _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
1557 bfd *abfd,
1558 const char *name,
1559 flagword flags,
1560 asection *section,
1561 bfd_vma value,
1562 const char *string,
1563 bfd_boolean copy,
1564 bfd_boolean collect,
1565 struct bfd_link_hash_entry **hashp)
1566 {
1567 enum link_row row;
1568 struct bfd_link_hash_entry *h;
1569 bfd_boolean cycle;
1570
1571 if (bfd_is_ind_section (section)
1572 || (flags & BSF_INDIRECT) != 0)
1573 row = INDR_ROW;
1574 else if ((flags & BSF_WARNING) != 0)
1575 row = WARN_ROW;
1576 else if ((flags & BSF_CONSTRUCTOR) != 0)
1577 row = SET_ROW;
1578 else if (bfd_is_und_section (section))
1579 {
1580 if ((flags & BSF_WEAK) != 0)
1581 row = UNDEFW_ROW;
1582 else
1583 row = UNDEF_ROW;
1584 }
1585 else if ((flags & BSF_WEAK) != 0)
1586 row = DEFW_ROW;
1587 else if (bfd_is_com_section (section))
1588 row = COMMON_ROW;
1589 else
1590 row = DEF_ROW;
1591
1592 if (hashp != NULL && *hashp != NULL)
1593 h = *hashp;
1594 else
1595 {
1596 if (row == UNDEF_ROW || row == UNDEFW_ROW)
1597 h = bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, copy, FALSE);
1598 else
1599 h = bfd_link_hash_lookup (info->hash, name, TRUE, copy, FALSE);
1600 if (h == NULL)
1601 {
1602 if (hashp != NULL)
1603 *hashp = NULL;
1604 return FALSE;
1605 }
1606 }
1607
1608 if (info->notice_all
1609 || (info->notice_hash != NULL
1610 && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL))
1611 {
1612 if (! (*info->callbacks->notice) (info, h->root.string, abfd, section,
1613 value))
1614 return FALSE;
1615 }
1616
1617 if (hashp != NULL)
1618 *hashp = h;
1619
1620 do
1621 {
1622 enum link_action action;
1623
1624 cycle = FALSE;
1625 action = link_action[(int) row][(int) h->type];
1626 switch (action)
1627 {
1628 case FAIL:
1629 abort ();
1630
1631 case NOACT:
1632 /* Do nothing. */
1633 break;
1634
1635 case UND:
1636 /* Make a new undefined symbol. */
1637 h->type = bfd_link_hash_undefined;
1638 h->u.undef.abfd = abfd;
1639 bfd_link_add_undef (info->hash, h);
1640 break;
1641
1642 case WEAK:
1643 /* Make a new weak undefined symbol. */
1644 h->type = bfd_link_hash_undefweak;
1645 h->u.undef.abfd = abfd;
1646 h->u.undef.weak = abfd;
1647 break;
1648
1649 case CDEF:
1650 /* We have found a definition for a symbol which was
1651 previously common. */
1652 BFD_ASSERT (h->type == bfd_link_hash_common);
1653 if (! ((*info->callbacks->multiple_common)
1654 (info, h, abfd, bfd_link_hash_defined, 0)))
1655 return FALSE;
1656 /* Fall through. */
1657 case DEF:
1658 case DEFW:
1659 {
1660 enum bfd_link_hash_type oldtype;
1661
1662 /* Define a symbol. */
1663 oldtype = h->type;
1664 if (action == DEFW)
1665 h->type = bfd_link_hash_defweak;
1666 else
1667 h->type = bfd_link_hash_defined;
1668 h->u.def.section = section;
1669 h->u.def.value = value;
1670
1671 /* If we have been asked to, we act like collect2 and
1672 identify all functions that might be global
1673 constructors and destructors and pass them up in a
1674 callback. We only do this for certain object file
1675 types, since many object file types can handle this
1676 automatically. */
1677 if (collect && name[0] == '_')
1678 {
1679 const char *s;
1680
1681 /* A constructor or destructor name starts like this:
1682 _+GLOBAL_[_.$][ID][_.$] where the first [_.$] and
1683 the second are the same character (we accept any
1684 character there, in case a new object file format
1685 comes along with even worse naming restrictions). */
1686
1687 #define CONS_PREFIX "GLOBAL_"
1688 #define CONS_PREFIX_LEN (sizeof CONS_PREFIX - 1)
1689
1690 s = name + 1;
1691 while (*s == '_')
1692 ++s;
1693 if (s[0] == 'G' && CONST_STRNEQ (s, CONS_PREFIX))
1694 {
1695 char c;
1696
1697 c = s[CONS_PREFIX_LEN + 1];
1698 if ((c == 'I' || c == 'D')
1699 && s[CONS_PREFIX_LEN] == s[CONS_PREFIX_LEN + 2])
1700 {
1701 /* If this is a definition of a symbol which
1702 was previously weakly defined, we are in
1703 trouble. We have already added a
1704 constructor entry for the weak defined
1705 symbol, and now we are trying to add one
1706 for the new symbol. Fortunately, this case
1707 should never arise in practice. */
1708 if (oldtype == bfd_link_hash_defweak)
1709 abort ();
1710
1711 if (! ((*info->callbacks->constructor)
1712 (info, c == 'I',
1713 h->root.string, abfd, section, value)))
1714 return FALSE;
1715 }
1716 }
1717 }
1718 }
1719
1720 break;
1721
1722 case COM:
1723 /* We have found a common definition for a symbol. */
1724 if (h->type == bfd_link_hash_new)
1725 bfd_link_add_undef (info->hash, h);
1726 h->type = bfd_link_hash_common;
1727 h->u.c.p = (struct bfd_link_hash_common_entry *)
1728 bfd_hash_allocate (&info->hash->table,
1729 sizeof (struct bfd_link_hash_common_entry));
1730 if (h->u.c.p == NULL)
1731 return FALSE;
1732
1733 h->u.c.size = value;
1734
1735 /* Select a default alignment based on the size. This may
1736 be overridden by the caller. */
1737 {
1738 unsigned int power;
1739
1740 power = bfd_log2 (value);
1741 if (power > 4)
1742 power = 4;
1743 h->u.c.p->alignment_power = power;
1744 }
1745
1746 /* The section of a common symbol is only used if the common
1747 symbol is actually allocated. It basically provides a
1748 hook for the linker script to decide which output section
1749 the common symbols should be put in. In most cases, the
1750 section of a common symbol will be bfd_com_section_ptr,
1751 the code here will choose a common symbol section named
1752 "COMMON", and the linker script will contain *(COMMON) in
1753 the appropriate place. A few targets use separate common
1754 sections for small symbols, and they require special
1755 handling. */
1756 if (section == bfd_com_section_ptr)
1757 {
1758 h->u.c.p->section = bfd_make_section_old_way (abfd, "COMMON");
1759 h->u.c.p->section->flags = SEC_ALLOC;
1760 }
1761 else if (section->owner != abfd)
1762 {
1763 h->u.c.p->section = bfd_make_section_old_way (abfd,
1764 section->name);
1765 h->u.c.p->section->flags = SEC_ALLOC;
1766 }
1767 else
1768 h->u.c.p->section = section;
1769 break;
1770
1771 case REF:
1772 /* A reference to a defined symbol. */
1773 if (h->u.undef.next == NULL && info->hash->undefs_tail != h)
1774 h->u.undef.next = h;
1775 break;
1776
1777 case BIG:
1778 /* We have found a common definition for a symbol which
1779 already had a common definition. Use the maximum of the
1780 two sizes, and use the section required by the larger symbol. */
1781 BFD_ASSERT (h->type == bfd_link_hash_common);
1782 if (! ((*info->callbacks->multiple_common)
1783 (info, h, abfd, bfd_link_hash_common, value)))
1784 return FALSE;
1785 if (value > h->u.c.size)
1786 {
1787 unsigned int power;
1788
1789 h->u.c.size = value;
1790
1791 /* Select a default alignment based on the size. This may
1792 be overridden by the caller. */
1793 power = bfd_log2 (value);
1794 if (power > 4)
1795 power = 4;
1796 h->u.c.p->alignment_power = power;
1797
1798 /* Some systems have special treatment for small commons,
1799 hence we want to select the section used by the larger
1800 symbol. This makes sure the symbol does not go in a
1801 small common section if it is now too large. */
1802 if (section == bfd_com_section_ptr)
1803 {
1804 h->u.c.p->section
1805 = bfd_make_section_old_way (abfd, "COMMON");
1806 h->u.c.p->section->flags = SEC_ALLOC;
1807 }
1808 else if (section->owner != abfd)
1809 {
1810 h->u.c.p->section
1811 = bfd_make_section_old_way (abfd, section->name);
1812 h->u.c.p->section->flags = SEC_ALLOC;
1813 }
1814 else
1815 h->u.c.p->section = section;
1816 }
1817 break;
1818
1819 case CREF:
1820 /* We have found a common definition for a symbol which
1821 was already defined. */
1822 if (! ((*info->callbacks->multiple_common)
1823 (info, h, abfd, bfd_link_hash_common, value)))
1824 return FALSE;
1825 break;
1826
1827 case MIND:
1828 /* Multiple indirect symbols. This is OK if they both point
1829 to the same symbol. */
1830 if (strcmp (h->u.i.link->root.string, string) == 0)
1831 break;
1832 /* Fall through. */
1833 case MDEF:
1834 /* Handle a multiple definition. */
1835 if (! ((*info->callbacks->multiple_definition)
1836 (info, h, abfd, section, value)))
1837 return FALSE;
1838 break;
1839
1840 case CIND:
1841 /* Create an indirect symbol from an existing common symbol. */
1842 BFD_ASSERT (h->type == bfd_link_hash_common);
1843 if (! ((*info->callbacks->multiple_common)
1844 (info, h, abfd, bfd_link_hash_indirect, 0)))
1845 return FALSE;
1846 /* Fall through. */
1847 case IND:
1848 /* Create an indirect symbol. */
1849 {
1850 struct bfd_link_hash_entry *inh;
1851
1852 /* STRING is the name of the symbol we want to indirect
1853 to. */
1854 inh = bfd_wrapped_link_hash_lookup (abfd, info, string, TRUE,
1855 copy, FALSE);
1856 if (inh == NULL)
1857 return FALSE;
1858 if (inh->type == bfd_link_hash_indirect
1859 && inh->u.i.link == h)
1860 {
1861 (*_bfd_error_handler)
1862 (_("%B: indirect symbol `%s' to `%s' is a loop"),
1863 abfd, name, string);
1864 bfd_set_error (bfd_error_invalid_operation);
1865 return FALSE;
1866 }
1867 if (inh->type == bfd_link_hash_new)
1868 {
1869 inh->type = bfd_link_hash_undefined;
1870 inh->u.undef.abfd = abfd;
1871 bfd_link_add_undef (info->hash, inh);
1872 }
1873
1874 /* If the indirect symbol has been referenced, we need to
1875 push the reference down to the symbol we are
1876 referencing. */
1877 if (h->type != bfd_link_hash_new)
1878 {
1879 row = UNDEF_ROW;
1880 cycle = TRUE;
1881 }
1882
1883 h->type = bfd_link_hash_indirect;
1884 h->u.i.link = inh;
1885 }
1886 break;
1887
1888 case SET:
1889 /* Add an entry to a set. */
1890 if (! (*info->callbacks->add_to_set) (info, h, BFD_RELOC_CTOR,
1891 abfd, section, value))
1892 return FALSE;
1893 break;
1894
1895 case WARNC:
1896 /* Issue a warning and cycle. */
1897 if (h->u.i.warning != NULL)
1898 {
1899 if (! (*info->callbacks->warning) (info, h->u.i.warning,
1900 h->root.string, abfd,
1901 NULL, 0))
1902 return FALSE;
1903 /* Only issue a warning once. */
1904 h->u.i.warning = NULL;
1905 }
1906 /* Fall through. */
1907 case CYCLE:
1908 /* Try again with the referenced symbol. */
1909 h = h->u.i.link;
1910 cycle = TRUE;
1911 break;
1912
1913 case REFC:
1914 /* A reference to an indirect symbol. */
1915 if (h->u.undef.next == NULL && info->hash->undefs_tail != h)
1916 h->u.undef.next = h;
1917 h = h->u.i.link;
1918 cycle = TRUE;
1919 break;
1920
1921 case WARN:
1922 /* Issue a warning. */
1923 if (! (*info->callbacks->warning) (info, string, h->root.string,
1924 hash_entry_bfd (h), NULL, 0))
1925 return FALSE;
1926 break;
1927
1928 case CWARN:
1929 /* Warn if this symbol has been referenced already,
1930 otherwise add a warning. A symbol has been referenced if
1931 the u.undef.next field is not NULL, or it is the tail of the
1932 undefined symbol list. The REF case above helps to
1933 ensure this. */
1934 if (h->u.undef.next != NULL || info->hash->undefs_tail == h)
1935 {
1936 if (! (*info->callbacks->warning) (info, string, h->root.string,
1937 hash_entry_bfd (h), NULL, 0))
1938 return FALSE;
1939 break;
1940 }
1941 /* Fall through. */
1942 case MWARN:
1943 /* Make a warning symbol. */
1944 {
1945 struct bfd_link_hash_entry *sub;
1946
1947 /* STRING is the warning to give. */
1948 sub = ((struct bfd_link_hash_entry *)
1949 ((*info->hash->table.newfunc)
1950 (NULL, &info->hash->table, h->root.string)));
1951 if (sub == NULL)
1952 return FALSE;
1953 *sub = *h;
1954 sub->type = bfd_link_hash_warning;
1955 sub->u.i.link = h;
1956 if (! copy)
1957 sub->u.i.warning = string;
1958 else
1959 {
1960 char *w;
1961 size_t len = strlen (string) + 1;
1962
1963 w = (char *) bfd_hash_allocate (&info->hash->table, len);
1964 if (w == NULL)
1965 return FALSE;
1966 memcpy (w, string, len);
1967 sub->u.i.warning = w;
1968 }
1969
1970 bfd_hash_replace (&info->hash->table,
1971 (struct bfd_hash_entry *) h,
1972 (struct bfd_hash_entry *) sub);
1973 if (hashp != NULL)
1974 *hashp = sub;
1975 }
1976 break;
1977 }
1978 }
1979 while (cycle);
1980
1981 return TRUE;
1982 }
1983 \f
1984 /* Generic final link routine. */
1985
1986 bfd_boolean
1987 _bfd_generic_final_link (bfd *abfd, struct bfd_link_info *info)
1988 {
1989 bfd *sub;
1990 asection *o;
1991 struct bfd_link_order *p;
1992 size_t outsymalloc;
1993 struct generic_write_global_symbol_info wginfo;
1994
1995 bfd_get_outsymbols (abfd) = NULL;
1996 bfd_get_symcount (abfd) = 0;
1997 outsymalloc = 0;
1998
1999 /* Mark all sections which will be included in the output file. */
2000 for (o = abfd->sections; o != NULL; o = o->next)
2001 for (p = o->map_head.link_order; p != NULL; p = p->next)
2002 if (p->type == bfd_indirect_link_order)
2003 p->u.indirect.section->linker_mark = TRUE;
2004
2005 /* Build the output symbol table. */
2006 for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
2007 if (! _bfd_generic_link_output_symbols (abfd, sub, info, &outsymalloc))
2008 return FALSE;
2009
2010 /* Accumulate the global symbols. */
2011 wginfo.info = info;
2012 wginfo.output_bfd = abfd;
2013 wginfo.psymalloc = &outsymalloc;
2014 _bfd_generic_link_hash_traverse (_bfd_generic_hash_table (info),
2015 _bfd_generic_link_write_global_symbol,
2016 &wginfo);
2017
2018 /* Make sure we have a trailing NULL pointer on OUTSYMBOLS. We
2019 shouldn't really need one, since we have SYMCOUNT, but some old
2020 code still expects one. */
2021 if (! generic_add_output_symbol (abfd, &outsymalloc, NULL))
2022 return FALSE;
2023
2024 if (info->relocatable)
2025 {
2026 /* Allocate space for the output relocs for each section. */
2027 for (o = abfd->sections; o != NULL; o = o->next)
2028 {
2029 o->reloc_count = 0;
2030 for (p = o->map_head.link_order; p != NULL; p = p->next)
2031 {
2032 if (p->type == bfd_section_reloc_link_order
2033 || p->type == bfd_symbol_reloc_link_order)
2034 ++o->reloc_count;
2035 else if (p->type == bfd_indirect_link_order)
2036 {
2037 asection *input_section;
2038 bfd *input_bfd;
2039 long relsize;
2040 arelent **relocs;
2041 asymbol **symbols;
2042 long reloc_count;
2043
2044 input_section = p->u.indirect.section;
2045 input_bfd = input_section->owner;
2046 relsize = bfd_get_reloc_upper_bound (input_bfd,
2047 input_section);
2048 if (relsize < 0)
2049 return FALSE;
2050 relocs = (arelent **) bfd_malloc (relsize);
2051 if (!relocs && relsize != 0)
2052 return FALSE;
2053 symbols = _bfd_generic_link_get_symbols (input_bfd);
2054 reloc_count = bfd_canonicalize_reloc (input_bfd,
2055 input_section,
2056 relocs,
2057 symbols);
2058 free (relocs);
2059 if (reloc_count < 0)
2060 return FALSE;
2061 BFD_ASSERT ((unsigned long) reloc_count
2062 == input_section->reloc_count);
2063 o->reloc_count += reloc_count;
2064 }
2065 }
2066 if (o->reloc_count > 0)
2067 {
2068 bfd_size_type amt;
2069
2070 amt = o->reloc_count;
2071 amt *= sizeof (arelent *);
2072 o->orelocation = (struct reloc_cache_entry **) bfd_alloc (abfd, amt);
2073 if (!o->orelocation)
2074 return FALSE;
2075 o->flags |= SEC_RELOC;
2076 /* Reset the count so that it can be used as an index
2077 when putting in the output relocs. */
2078 o->reloc_count = 0;
2079 }
2080 }
2081 }
2082
2083 /* Handle all the link order information for the sections. */
2084 for (o = abfd->sections; o != NULL; o = o->next)
2085 {
2086 for (p = o->map_head.link_order; p != NULL; p = p->next)
2087 {
2088 switch (p->type)
2089 {
2090 case bfd_section_reloc_link_order:
2091 case bfd_symbol_reloc_link_order:
2092 if (! _bfd_generic_reloc_link_order (abfd, info, o, p))
2093 return FALSE;
2094 break;
2095 case bfd_indirect_link_order:
2096 if (! default_indirect_link_order (abfd, info, o, p, TRUE))
2097 return FALSE;
2098 break;
2099 default:
2100 if (! _bfd_default_link_order (abfd, info, o, p))
2101 return FALSE;
2102 break;
2103 }
2104 }
2105 }
2106
2107 return TRUE;
2108 }
2109
2110 /* Add an output symbol to the output BFD. */
2111
2112 static bfd_boolean
2113 generic_add_output_symbol (bfd *output_bfd, size_t *psymalloc, asymbol *sym)
2114 {
2115 if (bfd_get_symcount (output_bfd) >= *psymalloc)
2116 {
2117 asymbol **newsyms;
2118 bfd_size_type amt;
2119
2120 if (*psymalloc == 0)
2121 *psymalloc = 124;
2122 else
2123 *psymalloc *= 2;
2124 amt = *psymalloc;
2125 amt *= sizeof (asymbol *);
2126 newsyms = (asymbol **) bfd_realloc (bfd_get_outsymbols (output_bfd), amt);
2127 if (newsyms == NULL)
2128 return FALSE;
2129 bfd_get_outsymbols (output_bfd) = newsyms;
2130 }
2131
2132 bfd_get_outsymbols (output_bfd) [bfd_get_symcount (output_bfd)] = sym;
2133 if (sym != NULL)
2134 ++ bfd_get_symcount (output_bfd);
2135
2136 return TRUE;
2137 }
2138
2139 /* Handle the symbols for an input BFD. */
2140
2141 bfd_boolean
2142 _bfd_generic_link_output_symbols (bfd *output_bfd,
2143 bfd *input_bfd,
2144 struct bfd_link_info *info,
2145 size_t *psymalloc)
2146 {
2147 asymbol **sym_ptr;
2148 asymbol **sym_end;
2149
2150 if (!bfd_generic_link_read_symbols (input_bfd))
2151 return FALSE;
2152
2153 /* Create a filename symbol if we are supposed to. */
2154 if (info->create_object_symbols_section != NULL)
2155 {
2156 asection *sec;
2157
2158 for (sec = input_bfd->sections; sec != NULL; sec = sec->next)
2159 {
2160 if (sec->output_section == info->create_object_symbols_section)
2161 {
2162 asymbol *newsym;
2163
2164 newsym = bfd_make_empty_symbol (input_bfd);
2165 if (!newsym)
2166 return FALSE;
2167 newsym->name = input_bfd->filename;
2168 newsym->value = 0;
2169 newsym->flags = BSF_LOCAL | BSF_FILE;
2170 newsym->section = sec;
2171
2172 if (! generic_add_output_symbol (output_bfd, psymalloc,
2173 newsym))
2174 return FALSE;
2175
2176 break;
2177 }
2178 }
2179 }
2180
2181 /* Adjust the values of the globally visible symbols, and write out
2182 local symbols. */
2183 sym_ptr = _bfd_generic_link_get_symbols (input_bfd);
2184 sym_end = sym_ptr + _bfd_generic_link_get_symcount (input_bfd);
2185 for (; sym_ptr < sym_end; sym_ptr++)
2186 {
2187 asymbol *sym;
2188 struct generic_link_hash_entry *h;
2189 bfd_boolean output;
2190
2191 h = NULL;
2192 sym = *sym_ptr;
2193 if ((sym->flags & (BSF_INDIRECT
2194 | BSF_WARNING
2195 | BSF_GLOBAL
2196 | BSF_CONSTRUCTOR
2197 | BSF_WEAK)) != 0
2198 || bfd_is_und_section (bfd_get_section (sym))
2199 || bfd_is_com_section (bfd_get_section (sym))
2200 || bfd_is_ind_section (bfd_get_section (sym)))
2201 {
2202 if (sym->udata.p != NULL)
2203 h = (struct generic_link_hash_entry *) sym->udata.p;
2204 else if ((sym->flags & BSF_CONSTRUCTOR) != 0)
2205 {
2206 /* This case normally means that the main linker code
2207 deliberately ignored this constructor symbol. We
2208 should just pass it through. This will screw up if
2209 the constructor symbol is from a different,
2210 non-generic, object file format, but the case will
2211 only arise when linking with -r, which will probably
2212 fail anyhow, since there will be no way to represent
2213 the relocs in the output format being used. */
2214 h = NULL;
2215 }
2216 else if (bfd_is_und_section (bfd_get_section (sym)))
2217 h = ((struct generic_link_hash_entry *)
2218 bfd_wrapped_link_hash_lookup (output_bfd, info,
2219 bfd_asymbol_name (sym),
2220 FALSE, FALSE, TRUE));
2221 else
2222 h = _bfd_generic_link_hash_lookup (_bfd_generic_hash_table (info),
2223 bfd_asymbol_name (sym),
2224 FALSE, FALSE, TRUE);
2225
2226 if (h != NULL)
2227 {
2228 /* Force all references to this symbol to point to
2229 the same area in memory. It is possible that
2230 this routine will be called with a hash table
2231 other than a generic hash table, so we double
2232 check that. */
2233 if (info->output_bfd->xvec == input_bfd->xvec)
2234 {
2235 if (h->sym != NULL)
2236 *sym_ptr = sym = h->sym;
2237 }
2238
2239 switch (h->root.type)
2240 {
2241 default:
2242 case bfd_link_hash_new:
2243 abort ();
2244 case bfd_link_hash_undefined:
2245 break;
2246 case bfd_link_hash_undefweak:
2247 sym->flags |= BSF_WEAK;
2248 break;
2249 case bfd_link_hash_indirect:
2250 h = (struct generic_link_hash_entry *) h->root.u.i.link;
2251 /* fall through */
2252 case bfd_link_hash_defined:
2253 sym->flags |= BSF_GLOBAL;
2254 sym->flags &=~ BSF_CONSTRUCTOR;
2255 sym->value = h->root.u.def.value;
2256 sym->section = h->root.u.def.section;
2257 break;
2258 case bfd_link_hash_defweak:
2259 sym->flags |= BSF_WEAK;
2260 sym->flags &=~ BSF_CONSTRUCTOR;
2261 sym->value = h->root.u.def.value;
2262 sym->section = h->root.u.def.section;
2263 break;
2264 case bfd_link_hash_common:
2265 sym->value = h->root.u.c.size;
2266 sym->flags |= BSF_GLOBAL;
2267 if (! bfd_is_com_section (sym->section))
2268 {
2269 BFD_ASSERT (bfd_is_und_section (sym->section));
2270 sym->section = bfd_com_section_ptr;
2271 }
2272 /* We do not set the section of the symbol to
2273 h->root.u.c.p->section. That value was saved so
2274 that we would know where to allocate the symbol
2275 if it was defined. In this case the type is
2276 still bfd_link_hash_common, so we did not define
2277 it, so we do not want to use that section. */
2278 break;
2279 }
2280 }
2281 }
2282
2283 /* This switch is straight from the old code in
2284 write_file_locals in ldsym.c. */
2285 if (info->strip == strip_all
2286 || (info->strip == strip_some
2287 && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym),
2288 FALSE, FALSE) == NULL))
2289 output = FALSE;
2290 else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0)
2291 {
2292 /* If this symbol is marked as occurring now, rather
2293 than at the end, output it now. This is used for
2294 COFF C_EXT FCN symbols. FIXME: There must be a
2295 better way. */
2296 if (bfd_asymbol_bfd (sym) == input_bfd
2297 && (sym->flags & BSF_NOT_AT_END) != 0)
2298 output = TRUE;
2299 else
2300 output = FALSE;
2301 }
2302 else if (bfd_is_ind_section (sym->section))
2303 output = FALSE;
2304 else if ((sym->flags & BSF_DEBUGGING) != 0)
2305 {
2306 if (info->strip == strip_none)
2307 output = TRUE;
2308 else
2309 output = FALSE;
2310 }
2311 else if (bfd_is_und_section (sym->section)
2312 || bfd_is_com_section (sym->section))
2313 output = FALSE;
2314 else if ((sym->flags & BSF_LOCAL) != 0)
2315 {
2316 if ((sym->flags & BSF_WARNING) != 0)
2317 output = FALSE;
2318 else
2319 {
2320 switch (info->discard)
2321 {
2322 default:
2323 case discard_all:
2324 output = FALSE;
2325 break;
2326 case discard_sec_merge:
2327 output = TRUE;
2328 if (info->relocatable
2329 || ! (sym->section->flags & SEC_MERGE))
2330 break;
2331 /* FALLTHROUGH */
2332 case discard_l:
2333 if (bfd_is_local_label (input_bfd, sym))
2334 output = FALSE;
2335 else
2336 output = TRUE;
2337 break;
2338 case discard_none:
2339 output = TRUE;
2340 break;
2341 }
2342 }
2343 }
2344 else if ((sym->flags & BSF_CONSTRUCTOR))
2345 {
2346 if (info->strip != strip_all)
2347 output = TRUE;
2348 else
2349 output = FALSE;
2350 }
2351 else
2352 abort ();
2353
2354 /* If this symbol is in a section which is not being included
2355 in the output file, then we don't want to output the
2356 symbol. */
2357 if (!bfd_is_abs_section (sym->section)
2358 && bfd_section_removed_from_list (output_bfd,
2359 sym->section->output_section))
2360 output = FALSE;
2361
2362 if (output)
2363 {
2364 if (! generic_add_output_symbol (output_bfd, psymalloc, sym))
2365 return FALSE;
2366 if (h != NULL)
2367 h->written = TRUE;
2368 }
2369 }
2370
2371 return TRUE;
2372 }
2373
2374 /* Set the section and value of a generic BFD symbol based on a linker
2375 hash table entry. */
2376
2377 static void
2378 set_symbol_from_hash (asymbol *sym, struct bfd_link_hash_entry *h)
2379 {
2380 switch (h->type)
2381 {
2382 default:
2383 abort ();
2384 break;
2385 case bfd_link_hash_new:
2386 /* This can happen when a constructor symbol is seen but we are
2387 not building constructors. */
2388 if (sym->section != NULL)
2389 {
2390 BFD_ASSERT ((sym->flags & BSF_CONSTRUCTOR) != 0);
2391 }
2392 else
2393 {
2394 sym->flags |= BSF_CONSTRUCTOR;
2395 sym->section = bfd_abs_section_ptr;
2396 sym->value = 0;
2397 }
2398 break;
2399 case bfd_link_hash_undefined:
2400 sym->section = bfd_und_section_ptr;
2401 sym->value = 0;
2402 break;
2403 case bfd_link_hash_undefweak:
2404 sym->section = bfd_und_section_ptr;
2405 sym->value = 0;
2406 sym->flags |= BSF_WEAK;
2407 break;
2408 case bfd_link_hash_defined:
2409 sym->section = h->u.def.section;
2410 sym->value = h->u.def.value;
2411 break;
2412 case bfd_link_hash_defweak:
2413 sym->flags |= BSF_WEAK;
2414 sym->section = h->u.def.section;
2415 sym->value = h->u.def.value;
2416 break;
2417 case bfd_link_hash_common:
2418 sym->value = h->u.c.size;
2419 if (sym->section == NULL)
2420 sym->section = bfd_com_section_ptr;
2421 else if (! bfd_is_com_section (sym->section))
2422 {
2423 BFD_ASSERT (bfd_is_und_section (sym->section));
2424 sym->section = bfd_com_section_ptr;
2425 }
2426 /* Do not set the section; see _bfd_generic_link_output_symbols. */
2427 break;
2428 case bfd_link_hash_indirect:
2429 case bfd_link_hash_warning:
2430 /* FIXME: What should we do here? */
2431 break;
2432 }
2433 }
2434
2435 /* Write out a global symbol, if it hasn't already been written out.
2436 This is called for each symbol in the hash table. */
2437
2438 bfd_boolean
2439 _bfd_generic_link_write_global_symbol (struct generic_link_hash_entry *h,
2440 void *data)
2441 {
2442 struct generic_write_global_symbol_info *wginfo =
2443 (struct generic_write_global_symbol_info *) data;
2444 asymbol *sym;
2445
2446 if (h->root.type == bfd_link_hash_warning)
2447 h = (struct generic_link_hash_entry *) h->root.u.i.link;
2448
2449 if (h->written)
2450 return TRUE;
2451
2452 h->written = TRUE;
2453
2454 if (wginfo->info->strip == strip_all
2455 || (wginfo->info->strip == strip_some
2456 && bfd_hash_lookup (wginfo->info->keep_hash, h->root.root.string,
2457 FALSE, FALSE) == NULL))
2458 return TRUE;
2459
2460 if (h->sym != NULL)
2461 sym = h->sym;
2462 else
2463 {
2464 sym = bfd_make_empty_symbol (wginfo->output_bfd);
2465 if (!sym)
2466 return FALSE;
2467 sym->name = h->root.root.string;
2468 sym->flags = 0;
2469 }
2470
2471 set_symbol_from_hash (sym, &h->root);
2472
2473 sym->flags |= BSF_GLOBAL;
2474
2475 if (! generic_add_output_symbol (wginfo->output_bfd, wginfo->psymalloc,
2476 sym))
2477 {
2478 /* FIXME: No way to return failure. */
2479 abort ();
2480 }
2481
2482 return TRUE;
2483 }
2484
2485 /* Create a relocation. */
2486
2487 bfd_boolean
2488 _bfd_generic_reloc_link_order (bfd *abfd,
2489 struct bfd_link_info *info,
2490 asection *sec,
2491 struct bfd_link_order *link_order)
2492 {
2493 arelent *r;
2494
2495 if (! info->relocatable)
2496 abort ();
2497 if (sec->orelocation == NULL)
2498 abort ();
2499
2500 r = (arelent *) bfd_alloc (abfd, sizeof (arelent));
2501 if (r == NULL)
2502 return FALSE;
2503
2504 r->address = link_order->offset;
2505 r->howto = bfd_reloc_type_lookup (abfd, link_order->u.reloc.p->reloc);
2506 if (r->howto == 0)
2507 {
2508 bfd_set_error (bfd_error_bad_value);
2509 return FALSE;
2510 }
2511
2512 /* Get the symbol to use for the relocation. */
2513 if (link_order->type == bfd_section_reloc_link_order)
2514 r->sym_ptr_ptr = link_order->u.reloc.p->u.section->symbol_ptr_ptr;
2515 else
2516 {
2517 struct generic_link_hash_entry *h;
2518
2519 h = ((struct generic_link_hash_entry *)
2520 bfd_wrapped_link_hash_lookup (abfd, info,
2521 link_order->u.reloc.p->u.name,
2522 FALSE, FALSE, TRUE));
2523 if (h == NULL
2524 || ! h->written)
2525 {
2526 if (! ((*info->callbacks->unattached_reloc)
2527 (info, link_order->u.reloc.p->u.name, NULL, NULL, 0)))
2528 return FALSE;
2529 bfd_set_error (bfd_error_bad_value);
2530 return FALSE;
2531 }
2532 r->sym_ptr_ptr = &h->sym;
2533 }
2534
2535 /* If this is an inplace reloc, write the addend to the object file.
2536 Otherwise, store it in the reloc addend. */
2537 if (! r->howto->partial_inplace)
2538 r->addend = link_order->u.reloc.p->addend;
2539 else
2540 {
2541 bfd_size_type size;
2542 bfd_reloc_status_type rstat;
2543 bfd_byte *buf;
2544 bfd_boolean ok;
2545 file_ptr loc;
2546
2547 size = bfd_get_reloc_size (r->howto);
2548 buf = (bfd_byte *) bfd_zmalloc (size);
2549 if (buf == NULL)
2550 return FALSE;
2551 rstat = _bfd_relocate_contents (r->howto, abfd,
2552 (bfd_vma) link_order->u.reloc.p->addend,
2553 buf);
2554 switch (rstat)
2555 {
2556 case bfd_reloc_ok:
2557 break;
2558 default:
2559 case bfd_reloc_outofrange:
2560 abort ();
2561 case bfd_reloc_overflow:
2562 if (! ((*info->callbacks->reloc_overflow)
2563 (info, NULL,
2564 (link_order->type == bfd_section_reloc_link_order
2565 ? bfd_section_name (abfd, link_order->u.reloc.p->u.section)
2566 : link_order->u.reloc.p->u.name),
2567 r->howto->name, link_order->u.reloc.p->addend,
2568 NULL, NULL, 0)))
2569 {
2570 free (buf);
2571 return FALSE;
2572 }
2573 break;
2574 }
2575 loc = link_order->offset * bfd_octets_per_byte (abfd);
2576 ok = bfd_set_section_contents (abfd, sec, buf, loc, size);
2577 free (buf);
2578 if (! ok)
2579 return FALSE;
2580
2581 r->addend = 0;
2582 }
2583
2584 sec->orelocation[sec->reloc_count] = r;
2585 ++sec->reloc_count;
2586
2587 return TRUE;
2588 }
2589 \f
2590 /* Allocate a new link_order for a section. */
2591
2592 struct bfd_link_order *
2593 bfd_new_link_order (bfd *abfd, asection *section)
2594 {
2595 bfd_size_type amt = sizeof (struct bfd_link_order);
2596 struct bfd_link_order *new_lo;
2597
2598 new_lo = (struct bfd_link_order *) bfd_zalloc (abfd, amt);
2599 if (!new_lo)
2600 return NULL;
2601
2602 new_lo->type = bfd_undefined_link_order;
2603
2604 if (section->map_tail.link_order != NULL)
2605 section->map_tail.link_order->next = new_lo;
2606 else
2607 section->map_head.link_order = new_lo;
2608 section->map_tail.link_order = new_lo;
2609
2610 return new_lo;
2611 }
2612
2613 /* Default link order processing routine. Note that we can not handle
2614 the reloc_link_order types here, since they depend upon the details
2615 of how the particular backends generates relocs. */
2616
2617 bfd_boolean
2618 _bfd_default_link_order (bfd *abfd,
2619 struct bfd_link_info *info,
2620 asection *sec,
2621 struct bfd_link_order *link_order)
2622 {
2623 switch (link_order->type)
2624 {
2625 case bfd_undefined_link_order:
2626 case bfd_section_reloc_link_order:
2627 case bfd_symbol_reloc_link_order:
2628 default:
2629 abort ();
2630 case bfd_indirect_link_order:
2631 return default_indirect_link_order (abfd, info, sec, link_order,
2632 FALSE);
2633 case bfd_data_link_order:
2634 return default_data_link_order (abfd, info, sec, link_order);
2635 }
2636 }
2637
2638 /* Default routine to handle a bfd_data_link_order. */
2639
2640 static bfd_boolean
2641 default_data_link_order (bfd *abfd,
2642 struct bfd_link_info *info ATTRIBUTE_UNUSED,
2643 asection *sec,
2644 struct bfd_link_order *link_order)
2645 {
2646 bfd_size_type size;
2647 size_t fill_size;
2648 bfd_byte *fill;
2649 file_ptr loc;
2650 bfd_boolean result;
2651
2652 BFD_ASSERT ((sec->flags & SEC_HAS_CONTENTS) != 0);
2653
2654 size = link_order->size;
2655 if (size == 0)
2656 return TRUE;
2657
2658 fill = link_order->u.data.contents;
2659 fill_size = link_order->u.data.size;
2660 if (fill_size != 0 && fill_size < size)
2661 {
2662 bfd_byte *p;
2663 fill = (bfd_byte *) bfd_malloc (size);
2664 if (fill == NULL)
2665 return FALSE;
2666 p = fill;
2667 if (fill_size == 1)
2668 memset (p, (int) link_order->u.data.contents[0], (size_t) size);
2669 else
2670 {
2671 do
2672 {
2673 memcpy (p, link_order->u.data.contents, fill_size);
2674 p += fill_size;
2675 size -= fill_size;
2676 }
2677 while (size >= fill_size);
2678 if (size != 0)
2679 memcpy (p, link_order->u.data.contents, (size_t) size);
2680 size = link_order->size;
2681 }
2682 }
2683
2684 loc = link_order->offset * bfd_octets_per_byte (abfd);
2685 result = bfd_set_section_contents (abfd, sec, fill, loc, size);
2686
2687 if (fill != link_order->u.data.contents)
2688 free (fill);
2689 return result;
2690 }
2691
2692 /* Default routine to handle a bfd_indirect_link_order. */
2693
2694 static bfd_boolean
2695 default_indirect_link_order (bfd *output_bfd,
2696 struct bfd_link_info *info,
2697 asection *output_section,
2698 struct bfd_link_order *link_order,
2699 bfd_boolean generic_linker)
2700 {
2701 asection *input_section;
2702 bfd *input_bfd;
2703 bfd_byte *contents = NULL;
2704 bfd_byte *new_contents;
2705 bfd_size_type sec_size;
2706 file_ptr loc;
2707
2708 BFD_ASSERT ((output_section->flags & SEC_HAS_CONTENTS) != 0);
2709
2710 input_section = link_order->u.indirect.section;
2711 input_bfd = input_section->owner;
2712 if (input_section->size == 0)
2713 return TRUE;
2714
2715 BFD_ASSERT (input_section->output_section == output_section);
2716 BFD_ASSERT (input_section->output_offset == link_order->offset);
2717 BFD_ASSERT (input_section->size == link_order->size);
2718
2719 if (info->relocatable
2720 && input_section->reloc_count > 0
2721 && output_section->orelocation == NULL)
2722 {
2723 /* Space has not been allocated for the output relocations.
2724 This can happen when we are called by a specific backend
2725 because somebody is attempting to link together different
2726 types of object files. Handling this case correctly is
2727 difficult, and sometimes impossible. */
2728 (*_bfd_error_handler)
2729 (_("Attempt to do relocatable link with %s input and %s output"),
2730 bfd_get_target (input_bfd), bfd_get_target (output_bfd));
2731 bfd_set_error (bfd_error_wrong_format);
2732 return FALSE;
2733 }
2734
2735 if (! generic_linker)
2736 {
2737 asymbol **sympp;
2738 asymbol **symppend;
2739
2740 /* Get the canonical symbols. The generic linker will always
2741 have retrieved them by this point, but we are being called by
2742 a specific linker, presumably because we are linking
2743 different types of object files together. */
2744 if (!bfd_generic_link_read_symbols (input_bfd))
2745 return FALSE;
2746
2747 /* Since we have been called by a specific linker, rather than
2748 the generic linker, the values of the symbols will not be
2749 right. They will be the values as seen in the input file,
2750 not the values of the final link. We need to fix them up
2751 before we can relocate the section. */
2752 sympp = _bfd_generic_link_get_symbols (input_bfd);
2753 symppend = sympp + _bfd_generic_link_get_symcount (input_bfd);
2754 for (; sympp < symppend; sympp++)
2755 {
2756 asymbol *sym;
2757 struct bfd_link_hash_entry *h;
2758
2759 sym = *sympp;
2760
2761 if ((sym->flags & (BSF_INDIRECT
2762 | BSF_WARNING
2763 | BSF_GLOBAL
2764 | BSF_CONSTRUCTOR
2765 | BSF_WEAK)) != 0
2766 || bfd_is_und_section (bfd_get_section (sym))
2767 || bfd_is_com_section (bfd_get_section (sym))
2768 || bfd_is_ind_section (bfd_get_section (sym)))
2769 {
2770 /* sym->udata may have been set by
2771 generic_link_add_symbol_list. */
2772 if (sym->udata.p != NULL)
2773 h = (struct bfd_link_hash_entry *) sym->udata.p;
2774 else if (bfd_is_und_section (bfd_get_section (sym)))
2775 h = bfd_wrapped_link_hash_lookup (output_bfd, info,
2776 bfd_asymbol_name (sym),
2777 FALSE, FALSE, TRUE);
2778 else
2779 h = bfd_link_hash_lookup (info->hash,
2780 bfd_asymbol_name (sym),
2781 FALSE, FALSE, TRUE);
2782 if (h != NULL)
2783 set_symbol_from_hash (sym, h);
2784 }
2785 }
2786 }
2787
2788 if ((output_section->flags & (SEC_GROUP | SEC_LINKER_CREATED)) == SEC_GROUP
2789 && input_section->size != 0)
2790 {
2791 /* Group section contents are set by bfd_elf_set_group_contents. */
2792 if (!output_bfd->output_has_begun)
2793 {
2794 /* FIXME: This hack ensures bfd_elf_set_group_contents is called. */
2795 if (!bfd_set_section_contents (output_bfd, output_section, "", 0, 1))
2796 goto error_return;
2797 }
2798 new_contents = output_section->contents;
2799 BFD_ASSERT (new_contents != NULL);
2800 BFD_ASSERT (input_section->output_offset == 0);
2801 }
2802 else
2803 {
2804 /* Get and relocate the section contents. */
2805 sec_size = (input_section->rawsize > input_section->size
2806 ? input_section->rawsize
2807 : input_section->size);
2808 contents = (bfd_byte *) bfd_malloc (sec_size);
2809 if (contents == NULL && sec_size != 0)
2810 goto error_return;
2811 new_contents = (bfd_get_relocated_section_contents
2812 (output_bfd, info, link_order, contents,
2813 info->relocatable,
2814 _bfd_generic_link_get_symbols (input_bfd)));
2815 if (!new_contents)
2816 goto error_return;
2817 }
2818
2819 /* Output the section contents. */
2820 loc = input_section->output_offset * bfd_octets_per_byte (output_bfd);
2821 if (! bfd_set_section_contents (output_bfd, output_section,
2822 new_contents, loc, input_section->size))
2823 goto error_return;
2824
2825 if (contents != NULL)
2826 free (contents);
2827 return TRUE;
2828
2829 error_return:
2830 if (contents != NULL)
2831 free (contents);
2832 return FALSE;
2833 }
2834
2835 /* A little routine to count the number of relocs in a link_order
2836 list. */
2837
2838 unsigned int
2839 _bfd_count_link_order_relocs (struct bfd_link_order *link_order)
2840 {
2841 register unsigned int c;
2842 register struct bfd_link_order *l;
2843
2844 c = 0;
2845 for (l = link_order; l != NULL; l = l->next)
2846 {
2847 if (l->type == bfd_section_reloc_link_order
2848 || l->type == bfd_symbol_reloc_link_order)
2849 ++c;
2850 }
2851
2852 return c;
2853 }
2854
2855 /*
2856 FUNCTION
2857 bfd_link_split_section
2858
2859 SYNOPSIS
2860 bfd_boolean bfd_link_split_section (bfd *abfd, asection *sec);
2861
2862 DESCRIPTION
2863 Return nonzero if @var{sec} should be split during a
2864 reloceatable or final link.
2865
2866 .#define bfd_link_split_section(abfd, sec) \
2867 . BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec))
2868 .
2869
2870 */
2871
2872 bfd_boolean
2873 _bfd_generic_link_split_section (bfd *abfd ATTRIBUTE_UNUSED,
2874 asection *sec ATTRIBUTE_UNUSED)
2875 {
2876 return FALSE;
2877 }
2878
2879 /*
2880 FUNCTION
2881 bfd_section_already_linked
2882
2883 SYNOPSIS
2884 void bfd_section_already_linked (bfd *abfd, asection *sec,
2885 struct bfd_link_info *info);
2886
2887 DESCRIPTION
2888 Check if @var{sec} has been already linked during a reloceatable
2889 or final link.
2890
2891 .#define bfd_section_already_linked(abfd, sec, info) \
2892 . BFD_SEND (abfd, _section_already_linked, (abfd, sec, info))
2893 .
2894
2895 */
2896
2897 /* Sections marked with the SEC_LINK_ONCE flag should only be linked
2898 once into the output. This routine checks each section, and
2899 arrange to discard it if a section of the same name has already
2900 been linked. This code assumes that all relevant sections have the
2901 SEC_LINK_ONCE flag set; that is, it does not depend solely upon the
2902 section name. bfd_section_already_linked is called via
2903 bfd_map_over_sections. */
2904
2905 /* The hash table. */
2906
2907 static struct bfd_hash_table _bfd_section_already_linked_table;
2908
2909 /* Support routines for the hash table used by section_already_linked,
2910 initialize the table, traverse, lookup, fill in an entry and remove
2911 the table. */
2912
2913 void
2914 bfd_section_already_linked_table_traverse
2915 (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *,
2916 void *), void *info)
2917 {
2918 bfd_hash_traverse (&_bfd_section_already_linked_table,
2919 (bfd_boolean (*) (struct bfd_hash_entry *,
2920 void *)) func,
2921 info);
2922 }
2923
2924 struct bfd_section_already_linked_hash_entry *
2925 bfd_section_already_linked_table_lookup (const char *name)
2926 {
2927 return ((struct bfd_section_already_linked_hash_entry *)
2928 bfd_hash_lookup (&_bfd_section_already_linked_table, name,
2929 TRUE, FALSE));
2930 }
2931
2932 bfd_boolean
2933 bfd_section_already_linked_table_insert
2934 (struct bfd_section_already_linked_hash_entry *already_linked_list,
2935 asection *sec)
2936 {
2937 struct bfd_section_already_linked *l;
2938
2939 /* Allocate the memory from the same obstack as the hash table is
2940 kept in. */
2941 l = (struct bfd_section_already_linked *)
2942 bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l);
2943 if (l == NULL)
2944 return FALSE;
2945 l->sec = sec;
2946 l->next = already_linked_list->entry;
2947 already_linked_list->entry = l;
2948 return TRUE;
2949 }
2950
2951 static struct bfd_hash_entry *
2952 already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED,
2953 struct bfd_hash_table *table,
2954 const char *string ATTRIBUTE_UNUSED)
2955 {
2956 struct bfd_section_already_linked_hash_entry *ret =
2957 (struct bfd_section_already_linked_hash_entry *)
2958 bfd_hash_allocate (table, sizeof *ret);
2959
2960 if (ret == NULL)
2961 return NULL;
2962
2963 ret->entry = NULL;
2964
2965 return &ret->root;
2966 }
2967
2968 bfd_boolean
2969 bfd_section_already_linked_table_init (void)
2970 {
2971 return bfd_hash_table_init_n (&_bfd_section_already_linked_table,
2972 already_linked_newfunc,
2973 sizeof (struct bfd_section_already_linked_hash_entry),
2974 42);
2975 }
2976
2977 void
2978 bfd_section_already_linked_table_free (void)
2979 {
2980 bfd_hash_table_free (&_bfd_section_already_linked_table);
2981 }
2982
2983 /* This is used on non-ELF inputs. */
2984
2985 void
2986 _bfd_generic_section_already_linked (bfd *abfd, asection *sec,
2987 struct bfd_link_info *info)
2988 {
2989 flagword flags;
2990 const char *name;
2991 struct bfd_section_already_linked *l;
2992 struct bfd_section_already_linked_hash_entry *already_linked_list;
2993
2994 flags = sec->flags;
2995 if ((flags & SEC_LINK_ONCE) == 0)
2996 return;
2997
2998 /* FIXME: When doing a relocatable link, we may have trouble
2999 copying relocations in other sections that refer to local symbols
3000 in the section being discarded. Those relocations will have to
3001 be converted somehow; as of this writing I'm not sure that any of
3002 the backends handle that correctly.
3003
3004 It is tempting to instead not discard link once sections when
3005 doing a relocatable link (technically, they should be discarded
3006 whenever we are building constructors). However, that fails,
3007 because the linker winds up combining all the link once sections
3008 into a single large link once section, which defeats the purpose
3009 of having link once sections in the first place. */
3010
3011 name = bfd_get_section_name (abfd, sec);
3012
3013 already_linked_list = bfd_section_already_linked_table_lookup (name);
3014
3015 for (l = already_linked_list->entry; l != NULL; l = l->next)
3016 {
3017 bfd_boolean skip = FALSE;
3018 struct coff_comdat_info *s_comdat
3019 = bfd_coff_get_comdat_section (abfd, sec);
3020 struct coff_comdat_info *l_comdat
3021 = bfd_coff_get_comdat_section (l->sec->owner, l->sec);
3022
3023 /* We may have 3 different sections on the list: group section,
3024 comdat section and linkonce section. SEC may be a linkonce or
3025 comdat section. We always ignore group section. For non-COFF
3026 inputs, we also ignore comdat section.
3027
3028 FIXME: Is that safe to match a linkonce section with a comdat
3029 section for COFF inputs? */
3030 if ((l->sec->flags & SEC_GROUP) != 0)
3031 skip = TRUE;
3032 else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour)
3033 {
3034 if (s_comdat != NULL
3035 && l_comdat != NULL
3036 && strcmp (s_comdat->name, l_comdat->name) != 0)
3037 skip = TRUE;
3038 }
3039 else if (l_comdat != NULL)
3040 skip = TRUE;
3041
3042 if (!skip)
3043 {
3044 /* The section has already been linked. See if we should
3045 issue a warning. */
3046 switch (flags & SEC_LINK_DUPLICATES)
3047 {
3048 default:
3049 abort ();
3050
3051 case SEC_LINK_DUPLICATES_DISCARD:
3052 break;
3053
3054 case SEC_LINK_DUPLICATES_ONE_ONLY:
3055 (*_bfd_error_handler)
3056 (_("%B: warning: ignoring duplicate section `%A'\n"),
3057 abfd, sec);
3058 break;
3059
3060 case SEC_LINK_DUPLICATES_SAME_CONTENTS:
3061 /* FIXME: We should really dig out the contents of both
3062 sections and memcmp them. The COFF/PE spec says that
3063 the Microsoft linker does not implement this
3064 correctly, so I'm not going to bother doing it
3065 either. */
3066 /* Fall through. */
3067 case SEC_LINK_DUPLICATES_SAME_SIZE:
3068 if (sec->size != l->sec->size)
3069 (*_bfd_error_handler)
3070 (_("%B: warning: duplicate section `%A' has different size\n"),
3071 abfd, sec);
3072 break;
3073 }
3074
3075 /* Set the output_section field so that lang_add_section
3076 does not create a lang_input_section structure for this
3077 section. Since there might be a symbol in the section
3078 being discarded, we must retain a pointer to the section
3079 which we are really going to use. */
3080 sec->output_section = bfd_abs_section_ptr;
3081 sec->kept_section = l->sec;
3082
3083 return;
3084 }
3085 }
3086
3087 /* This is the first section with this name. Record it. */
3088 if (! bfd_section_already_linked_table_insert (already_linked_list, sec))
3089 info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
3090 }
3091
3092 /* Convert symbols in excluded output sections to use a kept section. */
3093
3094 static bfd_boolean
3095 fix_syms (struct bfd_link_hash_entry *h, void *data)
3096 {
3097 bfd *obfd = (bfd *) data;
3098
3099 if (h->type == bfd_link_hash_warning)
3100 h = h->u.i.link;
3101
3102 if (h->type == bfd_link_hash_defined
3103 || h->type == bfd_link_hash_defweak)
3104 {
3105 asection *s = h->u.def.section;
3106 if (s != NULL
3107 && s->output_section != NULL
3108 && (s->output_section->flags & SEC_EXCLUDE) != 0
3109 && bfd_section_removed_from_list (obfd, s->output_section))
3110 {
3111 asection *op, *op1;
3112
3113 h->u.def.value += s->output_offset + s->output_section->vma;
3114
3115 /* Find preceding kept section. */
3116 for (op1 = s->output_section->prev; op1 != NULL; op1 = op1->prev)
3117 if ((op1->flags & SEC_EXCLUDE) == 0
3118 && !bfd_section_removed_from_list (obfd, op1))
3119 break;
3120
3121 /* Find following kept section. Start at prev->next because
3122 other sections may have been added after S was removed. */
3123 if (s->output_section->prev != NULL)
3124 op = s->output_section->prev->next;
3125 else
3126 op = s->output_section->owner->sections;
3127 for (; op != NULL; op = op->next)
3128 if ((op->flags & SEC_EXCLUDE) == 0
3129 && !bfd_section_removed_from_list (obfd, op))
3130 break;
3131
3132 /* Choose better of two sections, based on flags. The idea
3133 is to choose a section that will be in the same segment
3134 as S would have been if it was kept. */
3135 if (op1 == NULL)
3136 {
3137 if (op == NULL)
3138 op = bfd_abs_section_ptr;
3139 }
3140 else if (op == NULL)
3141 op = op1;
3142 else if (((op1->flags ^ op->flags)
3143 & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0)
3144 {
3145 if (((op->flags ^ s->flags)
3146 & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0
3147 /* We prefer to choose a loaded section. Section S
3148 doesn't have SEC_LOAD set (it being excluded, that
3149 part of the flag processing didn't happen) so we
3150 can't compare that flag to those of OP and OP1. */
3151 || ((op1->flags & SEC_LOAD) != 0
3152 && (op->flags & SEC_LOAD) == 0))
3153 op = op1;
3154 }
3155 else if (((op1->flags ^ op->flags) & SEC_READONLY) != 0)
3156 {
3157 if (((op->flags ^ s->flags) & SEC_READONLY) != 0)
3158 op = op1;
3159 }
3160 else if (((op1->flags ^ op->flags) & SEC_CODE) != 0)
3161 {
3162 if (((op->flags ^ s->flags) & SEC_CODE) != 0)
3163 op = op1;
3164 }
3165 else
3166 {
3167 /* Flags we care about are the same. Prefer the following
3168 section if that will result in a positive valued sym. */
3169 if (h->u.def.value < op->vma)
3170 op = op1;
3171 }
3172
3173 h->u.def.value -= op->vma;
3174 h->u.def.section = op;
3175 }
3176 }
3177
3178 return TRUE;
3179 }
3180
3181 void
3182 _bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info)
3183 {
3184 bfd_link_hash_traverse (info->hash, fix_syms, obfd);
3185 }
3186
3187 /*
3188 FUNCTION
3189 bfd_generic_define_common_symbol
3190
3191 SYNOPSIS
3192 bfd_boolean bfd_generic_define_common_symbol
3193 (bfd *output_bfd, struct bfd_link_info *info,
3194 struct bfd_link_hash_entry *h);
3195
3196 DESCRIPTION
3197 Convert common symbol @var{h} into a defined symbol.
3198 Return TRUE on success and FALSE on failure.
3199
3200 .#define bfd_define_common_symbol(output_bfd, info, h) \
3201 . BFD_SEND (output_bfd, _bfd_define_common_symbol, (output_bfd, info, h))
3202 .
3203 */
3204
3205 bfd_boolean
3206 bfd_generic_define_common_symbol (bfd *output_bfd,
3207 struct bfd_link_info *info ATTRIBUTE_UNUSED,
3208 struct bfd_link_hash_entry *h)
3209 {
3210 unsigned int power_of_two;
3211 bfd_vma alignment, size;
3212 asection *section;
3213
3214 BFD_ASSERT (h != NULL && h->type == bfd_link_hash_common);
3215
3216 size = h->u.c.size;
3217 power_of_two = h->u.c.p->alignment_power;
3218 section = h->u.c.p->section;
3219
3220 /* Increase the size of the section to align the common symbol.
3221 The alignment must be a power of two. */
3222 alignment = bfd_octets_per_byte (output_bfd) << power_of_two;
3223 BFD_ASSERT (alignment != 0 && (alignment & -alignment) == alignment);
3224 section->size += alignment - 1;
3225 section->size &= -alignment;
3226
3227 /* Adjust the section's overall alignment if necessary. */
3228 if (power_of_two > section->alignment_power)
3229 section->alignment_power = power_of_two;
3230
3231 /* Change the symbol from common to defined. */
3232 h->type = bfd_link_hash_defined;
3233 h->u.def.section = section;
3234 h->u.def.value = section->size;
3235
3236 /* Increase the size of the section. */
3237 section->size += size;
3238
3239 /* Make sure the section is allocated in memory, and make sure that
3240 it is no longer a common section. */
3241 section->flags |= SEC_ALLOC;
3242 section->flags &= ~SEC_IS_COMMON;
3243 return TRUE;
3244 }
3245
3246 /*
3247 FUNCTION
3248 bfd_find_version_for_sym
3249
3250 SYNOPSIS
3251 struct bfd_elf_version_tree * bfd_find_version_for_sym
3252 (struct bfd_elf_version_tree *verdefs,
3253 const char *sym_name, bfd_boolean *hide);
3254
3255 DESCRIPTION
3256 Search an elf version script tree for symbol versioning
3257 info and export / don't-export status for a given symbol.
3258 Return non-NULL on success and NULL on failure; also sets
3259 the output @samp{hide} boolean parameter.
3260
3261 */
3262
3263 struct bfd_elf_version_tree *
3264 bfd_find_version_for_sym (struct bfd_elf_version_tree *verdefs,
3265 const char *sym_name,
3266 bfd_boolean *hide)
3267 {
3268 struct bfd_elf_version_tree *t;
3269 struct bfd_elf_version_tree *local_ver, *global_ver, *exist_ver;
3270 struct bfd_elf_version_tree *star_local_ver, *star_global_ver;
3271
3272 local_ver = NULL;
3273 global_ver = NULL;
3274 star_local_ver = NULL;
3275 star_global_ver = NULL;
3276 exist_ver = NULL;
3277 for (t = verdefs; t != NULL; t = t->next)
3278 {
3279 if (t->globals.list != NULL)
3280 {
3281 struct bfd_elf_version_expr *d = NULL;
3282
3283 while ((d = (*t->match) (&t->globals, d, sym_name)) != NULL)
3284 {
3285 if (d->literal || strcmp (d->pattern, "*") != 0)
3286 global_ver = t;
3287 else
3288 star_global_ver = t;
3289 if (d->symver)
3290 exist_ver = t;
3291 d->script = 1;
3292 /* If the match is a wildcard pattern, keep looking for
3293 a more explicit, perhaps even local, match. */
3294 if (d->literal)
3295 break;
3296 }
3297
3298 if (d != NULL)
3299 break;
3300 }
3301
3302 if (t->locals.list != NULL)
3303 {
3304 struct bfd_elf_version_expr *d = NULL;
3305
3306 while ((d = (*t->match) (&t->locals, d, sym_name)) != NULL)
3307 {
3308 if (d->literal || strcmp (d->pattern, "*") != 0)
3309 local_ver = t;
3310 else
3311 star_local_ver = t;
3312 /* If the match is a wildcard pattern, keep looking for
3313 a more explicit, perhaps even global, match. */
3314 if (d->literal)
3315 {
3316 /* An exact match overrides a global wildcard. */
3317 global_ver = NULL;
3318 star_global_ver = NULL;
3319 break;
3320 }
3321 }
3322
3323 if (d != NULL)
3324 break;
3325 }
3326 }
3327
3328 if (global_ver == NULL && local_ver == NULL)
3329 global_ver = star_global_ver;
3330
3331 if (global_ver != NULL)
3332 {
3333 /* If we already have a versioned symbol that matches the
3334 node for this symbol, then we don't want to create a
3335 duplicate from the unversioned symbol. Instead hide the
3336 unversioned symbol. */
3337 *hide = exist_ver == global_ver;
3338 return global_ver;
3339 }
3340
3341 if (local_ver == NULL)
3342 local_ver = star_local_ver;
3343
3344 if (local_ver != NULL)
3345 {
3346 *hide = TRUE;
3347 return local_ver;
3348 }
3349
3350 return NULL;
3351 }