1 /* BFD library -- caching of file descriptors.
2
3 Copyright (C) 1990-2024 Free Software Foundation, Inc.
4
5 Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com).
6
7 This file is part of BFD, the Binary File Descriptor library.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 MA 02110-1301, USA. */
23
24 /*
25 SECTION
26 File caching
27
28 The file caching mechanism is embedded within BFD and allows
29 the application to open as many BFDs as it wants without
30 regard to the underlying operating system's file descriptor
31 limit (often as low as 20 open files). The module in
32 <<cache.c>> maintains a least recently used list of
33 <<bfd_cache_max_open>> files, and exports the name
34 <<bfd_cache_lookup>>, which runs around and makes sure that
35 the required BFD is open. If not, then it chooses a file to
36 close, closes it and opens the one wanted, returning its file
37 handle.
38
39 SUBSECTION
40 Caching functions
41 */
42
43 #include "sysdep.h"
44 #include "bfd.h"
45 #include "libbfd.h"
46 #include "libiberty.h"
47
48 #ifdef HAVE_MMAP
49 #include <sys/mman.h>
50 #endif
51
52 static FILE *_bfd_open_file_unlocked (bfd *abfd);
53
54 /* In some cases we can optimize cache operation when reopening files.
55 For instance, a flush is entirely unnecessary if the file is already
56 closed, so a flush would use CACHE_NO_OPEN. Similarly, a seek using
57 SEEK_SET or SEEK_END need not first seek to the current position.
58 For stat we ignore seek errors, just in case the file has changed
59 while we weren't looking. If it has, then it's possible that the
60 file is shorter and we don't want a seek error to prevent us doing
61 the stat. */
62 enum cache_flag {
63 CACHE_NORMAL = 0,
64 CACHE_NO_OPEN = 1,
65 CACHE_NO_SEEK = 2,
66 CACHE_NO_SEEK_ERROR = 4
67 };
68
69 /* The maximum number of files which the cache will keep open at
70 one time. When needed call bfd_cache_max_open to initialize. */
71
72 static unsigned max_open_files = 0;
73
74 /* Set max_open_files, if not already set, to 12.5% of the allowed open
75 file descriptors, but at least 10, and return the value. */
76 static unsigned
bfd_cache_max_open(void)77 bfd_cache_max_open (void)
78 {
79 if (max_open_files == 0)
80 {
81 int max;
82 #if defined(__sun) && !defined(__sparcv9) && !defined(__x86_64__)
83 /* PR ld/19260: 32-bit Solaris has very inelegant handling of the 255
84 file descriptor limit. The problem is that setrlimit(2) can raise
85 RLIMIT_NOFILE to a value that is not supported by libc, resulting
86 in "Too many open files" errors. This can happen here even though
87 max_open_files is set to rlim.rlim_cur / 8. For example, if
88 a parent process has set rlim.rlim_cur to 65536, then max_open_files
89 will be computed as 8192.
90
91 This check essentially reverts to the behavior from binutils 2.23.1
92 for 32-bit Solaris only. (It is hoped that the 32-bit libc
93 limitation will be removed soon). 64-bit Solaris libc does not have
94 this limitation. */
95 max = 16;
96 #else
97 #ifdef HAVE_GETRLIMIT
98 struct rlimit rlim;
99
100 if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
101 && rlim.rlim_cur != (rlim_t) RLIM_INFINITY)
102 max = rlim.rlim_cur / 8;
103 else
104 #endif
105 #ifdef _SC_OPEN_MAX
106 max = sysconf (_SC_OPEN_MAX) / 8;
107 #else
108 max = 10;
109 #endif
110 #endif /* not 32-bit Solaris */
111
112 max_open_files = max < 10 ? 10 : max;
113 }
114
115 return max_open_files;
116 }
117
118 /* The number of BFD files we have open. */
119
120 static unsigned open_files;
121
122 /* Zero, or a pointer to the topmost BFD on the chain. This is
123 used by the <<bfd_cache_lookup>> macro in @file{libbfd.h} to
124 determine when it can avoid a function call. */
125
126 static bfd *bfd_last_cache = NULL;
127
128 /* Insert a BFD into the cache. */
129
130 static void
insert(bfd * abfd)131 insert (bfd *abfd)
132 {
133 if (bfd_last_cache == NULL)
134 {
135 abfd->lru_next = abfd;
136 abfd->lru_prev = abfd;
137 }
138 else
139 {
140 abfd->lru_next = bfd_last_cache;
141 abfd->lru_prev = bfd_last_cache->lru_prev;
142 abfd->lru_prev->lru_next = abfd;
143 abfd->lru_next->lru_prev = abfd;
144 }
145 bfd_last_cache = abfd;
146 }
147
148 /* Remove a BFD from the cache. */
149
150 static void
snip(bfd * abfd)151 snip (bfd *abfd)
152 {
153 abfd->lru_prev->lru_next = abfd->lru_next;
154 abfd->lru_next->lru_prev = abfd->lru_prev;
155 if (abfd == bfd_last_cache)
156 {
157 bfd_last_cache = abfd->lru_next;
158 if (abfd == bfd_last_cache)
159 bfd_last_cache = NULL;
160 }
161 }
162
163 /* Close a BFD and remove it from the cache. */
164
165 static bool
bfd_cache_delete(bfd * abfd)166 bfd_cache_delete (bfd *abfd)
167 {
168 bool ret;
169
170 if (fclose ((FILE *) abfd->iostream) == 0)
171 ret = true;
172 else
173 {
174 ret = false;
175 bfd_set_error (bfd_error_system_call);
176 }
177
178 snip (abfd);
179
180 abfd->iostream = NULL;
181 BFD_ASSERT (open_files > 0);
182 --open_files;
183 abfd->flags |= BFD_CLOSED_BY_CACHE;
184
185 return ret;
186 }
187
188 /* We need to open a new file, and the cache is full. Find the least
189 recently used cacheable BFD and close it. */
190
191 static bool
close_one(void)192 close_one (void)
193 {
194 register bfd *to_kill;
195
196 if (bfd_last_cache == NULL)
197 to_kill = NULL;
198 else
199 {
200 for (to_kill = bfd_last_cache->lru_prev;
201 ! to_kill->cacheable;
202 to_kill = to_kill->lru_prev)
203 {
204 if (to_kill == bfd_last_cache)
205 {
206 to_kill = NULL;
207 break;
208 }
209 }
210 }
211
212 if (to_kill == NULL)
213 {
214 /* There are no open cacheable BFD's. */
215 return true;
216 }
217
218 to_kill->where = _bfd_real_ftell ((FILE *) to_kill->iostream);
219
220 return bfd_cache_delete (to_kill);
221 }
222
223 /* Check to see if the required BFD is the same as the last one
224 looked up. If so, then it can use the stream in the BFD with
225 impunity, since it can't have changed since the last lookup;
226 otherwise, it has to perform the complicated lookup function. */
227
228 #define bfd_cache_lookup(x, flag) \
229 ((x) == bfd_last_cache \
230 ? (FILE *) (bfd_last_cache->iostream) \
231 : bfd_cache_lookup_worker (x, flag))
232
233 /* Called when the macro <<bfd_cache_lookup>> fails to find a
234 quick answer. Find a file descriptor for @var{abfd}. If
235 necessary, it open it. If there are already more than
236 <<bfd_cache_max_open>> files open, it tries to close one first, to
237 avoid running out of file descriptors. It will return NULL
238 if it is unable to (re)open the @var{abfd}. */
239
240 static FILE *
bfd_cache_lookup_worker(bfd * abfd,enum cache_flag flag)241 bfd_cache_lookup_worker (bfd *abfd, enum cache_flag flag)
242 {
243 if ((abfd->flags & BFD_IN_MEMORY) != 0)
244 abort ();
245
246 if (abfd->my_archive != NULL
247 && !bfd_is_thin_archive (abfd->my_archive))
248 abort ();
249
250 if (abfd->iostream != NULL)
251 {
252 /* Move the file to the start of the cache. */
253 if (abfd != bfd_last_cache)
254 {
255 snip (abfd);
256 insert (abfd);
257 }
258 return (FILE *) abfd->iostream;
259 }
260
261 if (flag & CACHE_NO_OPEN)
262 return NULL;
263
264 if (_bfd_open_file_unlocked (abfd) == NULL)
265 ;
266 else if (!(flag & CACHE_NO_SEEK)
267 && _bfd_real_fseek ((FILE *) abfd->iostream,
268 abfd->where, SEEK_SET) != 0
269 && !(flag & CACHE_NO_SEEK_ERROR))
270 bfd_set_error (bfd_error_system_call);
271 else
272 return (FILE *) abfd->iostream;
273
274 /* xgettext:c-format */
275 _bfd_error_handler (_("reopening %pB: %s"),
276 abfd, bfd_errmsg (bfd_get_error ()));
277 return NULL;
278 }
279
280 static file_ptr
cache_btell(struct bfd * abfd)281 cache_btell (struct bfd *abfd)
282 {
283 if (!bfd_lock ())
284 return -1;
285 FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
286 if (f == NULL)
287 {
288 if (!bfd_unlock ())
289 return -1;
290 return abfd->where;
291 }
292 file_ptr result = _bfd_real_ftell (f);
293 if (!bfd_unlock ())
294 return -1;
295 return result;
296 }
297
298 static int
cache_bseek(struct bfd * abfd,file_ptr offset,int whence)299 cache_bseek (struct bfd *abfd, file_ptr offset, int whence)
300 {
301 if (!bfd_lock ())
302 return -1;
303 FILE *f = bfd_cache_lookup (abfd, whence != SEEK_CUR ? CACHE_NO_SEEK : CACHE_NORMAL);
304 if (f == NULL)
305 {
306 bfd_unlock ();
307 return -1;
308 }
309 int result = _bfd_real_fseek (f, offset, whence);
310 if (!bfd_unlock ())
311 return -1;
312 return result;
313 }
314
315 /* Note that archive entries don't have streams; they share their parent's.
316 This allows someone to play with the iostream behind BFD's back.
317
318 Also, note that the origin pointer points to the beginning of a file's
319 contents (0 for non-archive elements). For archive entries this is the
320 first octet in the file, NOT the beginning of the archive header. */
321
322 static file_ptr
cache_bread_1(FILE * f,void * buf,file_ptr nbytes)323 cache_bread_1 (FILE *f, void *buf, file_ptr nbytes)
324 {
325 file_ptr nread;
326
327 #if defined (__VAX) && defined (VMS)
328 /* Apparently fread on Vax VMS does not keep the record length
329 information. */
330 nread = read (fileno (f), buf, nbytes);
331 /* Set bfd_error if we did not read as much data as we expected. If
332 the read failed due to an error set the bfd_error_system_call,
333 else set bfd_error_file_truncated. */
334 if (nread == (file_ptr)-1)
335 {
336 bfd_set_error (bfd_error_system_call);
337 return nread;
338 }
339 #else
340 nread = fread (buf, 1, nbytes, f);
341 /* Set bfd_error if we did not read as much data as we expected. If
342 the read failed due to an error set the bfd_error_system_call,
343 else set bfd_error_file_truncated. */
344 if (nread < nbytes && ferror (f))
345 {
346 bfd_set_error (bfd_error_system_call);
347 return nread;
348 }
349 #endif
350 if (nread < nbytes)
351 /* This may or may not be an error, but in case the calling code
352 bails out because of it, set the right error code. */
353 bfd_set_error (bfd_error_file_truncated);
354 return nread;
355 }
356
357 static file_ptr
cache_bread(struct bfd * abfd,void * buf,file_ptr nbytes)358 cache_bread (struct bfd *abfd, void *buf, file_ptr nbytes)
359 {
360 if (!bfd_lock ())
361 return -1;
362 file_ptr nread = 0;
363 FILE *f;
364
365 f = bfd_cache_lookup (abfd, CACHE_NORMAL);
366 if (f == NULL)
367 {
368 bfd_unlock ();
369 return -1;
370 }
371
372 /* Some filesystems are unable to handle reads that are too large
373 (for instance, NetApp shares with oplocks turned off). To avoid
374 hitting this limitation, we read the buffer in chunks of 8MB max. */
375 while (nread < nbytes)
376 {
377 const file_ptr max_chunk_size = 0x800000;
378 file_ptr chunk_size = nbytes - nread;
379 file_ptr chunk_nread;
380
381 if (chunk_size > max_chunk_size)
382 chunk_size = max_chunk_size;
383
384 chunk_nread = cache_bread_1 (f, (char *) buf + nread, chunk_size);
385
386 /* Update the nread count.
387
388 We just have to be careful of the case when cache_bread_1 returns
389 a negative count: If this is our first read, then set nread to
390 that negative count in order to return that negative value to the
391 caller. Otherwise, don't add it to our total count, or we would
392 end up returning a smaller number of bytes read than we actually
393 did. */
394 if (nread == 0 || chunk_nread > 0)
395 nread += chunk_nread;
396
397 if (chunk_nread < chunk_size)
398 break;
399 }
400
401 if (!bfd_unlock ())
402 return -1;
403 return nread;
404 }
405
406 static file_ptr
cache_bwrite(struct bfd * abfd,const void * from,file_ptr nbytes)407 cache_bwrite (struct bfd *abfd, const void *from, file_ptr nbytes)
408 {
409 if (!bfd_lock ())
410 return -1;
411 file_ptr nwrite;
412 FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL);
413
414 if (f == NULL)
415 {
416 if (!bfd_unlock ())
417 return -1;
418 return 0;
419 }
420 nwrite = fwrite (from, 1, nbytes, f);
421 if (nwrite < nbytes && ferror (f))
422 {
423 bfd_set_error (bfd_error_system_call);
424 bfd_unlock ();
425 return -1;
426 }
427 if (!bfd_unlock ())
428 return -1;
429 return nwrite;
430 }
431
432 static int
cache_bclose(struct bfd * abfd)433 cache_bclose (struct bfd *abfd)
434 {
435 /* No locking needed here, it's handled by the callee. */
436 return bfd_cache_close (abfd) - 1;
437 }
438
439 static int
cache_bflush(struct bfd * abfd)440 cache_bflush (struct bfd *abfd)
441 {
442 if (!bfd_lock ())
443 return -1;
444 int sts;
445 FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
446
447 if (f == NULL)
448 {
449 if (!bfd_unlock ())
450 return -1;
451 return 0;
452 }
453 sts = fflush (f);
454 if (sts < 0)
455 bfd_set_error (bfd_error_system_call);
456 if (!bfd_unlock ())
457 return -1;
458 return sts;
459 }
460
461 static int
cache_bstat(struct bfd * abfd,struct stat * sb)462 cache_bstat (struct bfd *abfd, struct stat *sb)
463 {
464 if (!bfd_lock ())
465 return -1;
466 int sts;
467 FILE *f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
468
469 if (f == NULL)
470 {
471 bfd_unlock ();
472 return -1;
473 }
474 sts = fstat (fileno (f), sb);
475 if (sts < 0)
476 bfd_set_error (bfd_error_system_call);
477 if (!bfd_unlock ())
478 return -1;
479 return sts;
480 }
481
482 static void *
cache_bmmap(struct bfd * abfd ATTRIBUTE_UNUSED,void * addr ATTRIBUTE_UNUSED,bfd_size_type len ATTRIBUTE_UNUSED,int prot ATTRIBUTE_UNUSED,int flags ATTRIBUTE_UNUSED,file_ptr offset ATTRIBUTE_UNUSED,void ** map_addr ATTRIBUTE_UNUSED,bfd_size_type * map_len ATTRIBUTE_UNUSED)483 cache_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED,
484 void *addr ATTRIBUTE_UNUSED,
485 bfd_size_type len ATTRIBUTE_UNUSED,
486 int prot ATTRIBUTE_UNUSED,
487 int flags ATTRIBUTE_UNUSED,
488 file_ptr offset ATTRIBUTE_UNUSED,
489 void **map_addr ATTRIBUTE_UNUSED,
490 bfd_size_type *map_len ATTRIBUTE_UNUSED)
491 {
492 void *ret = (void *) -1;
493
494 if (!bfd_lock ())
495 return ret;
496 if ((abfd->flags & BFD_IN_MEMORY) != 0)
497 abort ();
498 #ifdef HAVE_MMAP
499 else
500 {
501 static uintptr_t pagesize_m1;
502 FILE *f;
503 file_ptr pg_offset;
504 bfd_size_type pg_len;
505
506 f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
507 if (f == NULL)
508 {
509 bfd_unlock ();
510 return ret;
511 }
512
513 if (pagesize_m1 == 0)
514 pagesize_m1 = getpagesize () - 1;
515
516 /* Align. */
517 pg_offset = offset & ~pagesize_m1;
518 pg_len = (len + (offset - pg_offset) + pagesize_m1) & ~pagesize_m1;
519
520 ret = mmap (addr, pg_len, prot, flags, fileno (f), pg_offset);
521 if (ret == (void *) -1)
522 bfd_set_error (bfd_error_system_call);
523 else
524 {
525 *map_addr = ret;
526 *map_len = pg_len;
527 ret = (char *) ret + (offset & pagesize_m1);
528 }
529 }
530 #endif
531
532 if (!bfd_unlock ())
533 return (void *) -1;
534 return ret;
535 }
536
537 static const struct bfd_iovec cache_iovec =
538 {
539 &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek,
540 &cache_bclose, &cache_bflush, &cache_bstat, &cache_bmmap
541 };
542
543 static bool
_bfd_cache_init_unlocked(bfd * abfd)544 _bfd_cache_init_unlocked (bfd *abfd)
545 {
546 BFD_ASSERT (abfd->iostream != NULL);
547 if (open_files >= bfd_cache_max_open ())
548 {
549 if (! close_one ())
550 return false;
551 }
552 abfd->iovec = &cache_iovec;
553 insert (abfd);
554 abfd->flags &= ~BFD_CLOSED_BY_CACHE;
555 ++open_files;
556 return true;
557 }
558
559 /*
560 INTERNAL_FUNCTION
561 bfd_cache_init
562
563 SYNOPSIS
564 bool bfd_cache_init (bfd *abfd);
565
566 DESCRIPTION
567 Add a newly opened BFD to the cache.
568 */
569
570 bool
bfd_cache_init(bfd * abfd)571 bfd_cache_init (bfd *abfd)
572 {
573 if (!bfd_lock ())
574 return false;
575 bool result = _bfd_cache_init_unlocked (abfd);
576 if (!bfd_unlock ())
577 return false;
578 return result;
579 }
580
581 static bool
_bfd_cache_close_unlocked(bfd * abfd)582 _bfd_cache_close_unlocked (bfd *abfd)
583 {
584 /* Don't remove this test. bfd_reinit depends on it. */
585 if (abfd->iovec != &cache_iovec)
586 return true;
587
588 if (abfd->iostream == NULL)
589 /* Previously closed. */
590 return true;
591
592 /* Note: no locking needed in this function, as it is handled by
593 bfd_cache_delete. */
594 return bfd_cache_delete (abfd);
595 }
596
597 /*
598 FUNCTION
599 bfd_cache_close
600
601 SYNOPSIS
602 bool bfd_cache_close (bfd *abfd);
603
604 DESCRIPTION
605 Remove the BFD @var{abfd} from the cache. If the attached file is open,
606 then close it too.
607
608 <<FALSE>> is returned if closing the file fails, <<TRUE>> is
609 returned if all is well.
610 */
611
612 bool
bfd_cache_close(bfd * abfd)613 bfd_cache_close (bfd *abfd)
614 {
615 if (!bfd_lock ())
616 return false;
617 bool result = _bfd_cache_close_unlocked (abfd);
618 if (!bfd_unlock ())
619 return false;
620 return result;
621 }
622
623 /*
624 FUNCTION
625 bfd_cache_close_all
626
627 SYNOPSIS
628 bool bfd_cache_close_all (void);
629
630 DESCRIPTION
631 Remove all BFDs from the cache. If the attached file is open,
632 then close it too. Note - despite its name this function will
633 close a BFD even if it is not marked as being cacheable, ie
634 even if bfd_get_cacheable() returns false.
635
636 <<FALSE>> is returned if closing one of the file fails, <<TRUE>> is
637 returned if all is well.
638 */
639
640 bool
bfd_cache_close_all(void)641 bfd_cache_close_all (void)
642 {
643 bool ret = true;
644
645 if (!bfd_lock ())
646 return false;
647 while (bfd_last_cache != NULL)
648 {
649 bfd *prev_bfd_last_cache = bfd_last_cache;
650
651 ret &= _bfd_cache_close_unlocked (bfd_last_cache);
652
653 /* Stop a potential infinite loop should bfd_cache_close()
654 not update bfd_last_cache. */
655 if (bfd_last_cache == prev_bfd_last_cache)
656 break;
657 }
658
659 if (!bfd_unlock ())
660 return false;
661 return ret;
662 }
663
664 /*
665 FUNCTION
666 bfd_cache_size
667
668 SYNOPSIS
669 unsigned bfd_cache_size (void);
670
671 DESCRIPTION
672 Return the number of open files in the cache.
673 */
674
675 unsigned
bfd_cache_size(void)676 bfd_cache_size (void)
677 {
678 return open_files;
679 }
680
681 static FILE *
_bfd_open_file_unlocked(bfd * abfd)682 _bfd_open_file_unlocked (bfd *abfd)
683 {
684 abfd->cacheable = true; /* Allow it to be closed later. */
685
686 if (open_files >= bfd_cache_max_open ())
687 {
688 if (! close_one ())
689 return NULL;
690 }
691
692 switch (abfd->direction)
693 {
694 case read_direction:
695 case no_direction:
696 abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd), FOPEN_RB);
697 break;
698 case both_direction:
699 case write_direction:
700 if (abfd->opened_once)
701 {
702 abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd),
703 FOPEN_RUB);
704 if (abfd->iostream == NULL)
705 abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd),
706 FOPEN_WUB);
707 }
708 else
709 {
710 /* Create the file.
711
712 Some operating systems won't let us overwrite a running
713 binary. For them, we want to unlink the file first.
714
715 However, gcc 2.95 will create temporary files using
716 O_EXCL and tight permissions to prevent other users from
717 substituting other .o files during the compilation. gcc
718 will then tell the assembler to use the newly created
719 file as an output file. If we unlink the file here, we
720 open a brief window when another user could still
721 substitute a file.
722
723 So we unlink the output file if and only if it has
724 non-zero size. */
725 #ifndef __MSDOS__
726 /* Don't do this for MSDOS: it doesn't care about overwriting
727 a running binary, but if this file is already open by
728 another BFD, we will be in deep trouble if we delete an
729 open file. In fact, objdump does just that if invoked with
730 the --info option. */
731 struct stat s;
732
733 if (stat (bfd_get_filename (abfd), &s) == 0 && s.st_size != 0)
734 unlink_if_ordinary (bfd_get_filename (abfd));
735 #endif
736 abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd),
737 FOPEN_WUB);
738 abfd->opened_once = true;
739 }
740 break;
741 }
742
743 if (abfd->iostream == NULL)
744 bfd_set_error (bfd_error_system_call);
745 else
746 {
747 if (! _bfd_cache_init_unlocked (abfd))
748 return NULL;
749 }
750
751 return (FILE *) abfd->iostream;
752 }
753
754 /*
755 INTERNAL_FUNCTION
756 bfd_open_file
757
758 SYNOPSIS
759 FILE* bfd_open_file (bfd *abfd);
760
761 DESCRIPTION
762 Call the OS to open a file for @var{abfd}. Return the <<FILE *>>
763 (possibly <<NULL>>) that results from this operation. Set up the
764 BFD so that future accesses know the file is open. If the <<FILE *>>
765 returned is <<NULL>>, then it won't have been put in the
766 cache, so it won't have to be removed from it.
767 */
768
769 FILE *
bfd_open_file(bfd * abfd)770 bfd_open_file (bfd *abfd)
771 {
772 if (!bfd_lock ())
773 return NULL;
774 FILE *result = _bfd_open_file_unlocked (abfd);
775 if (!bfd_unlock ())
776 return NULL;
777 return result;
778 }
779