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