| /* BFD library -- caching of file descriptors. |
| |
| Copyright (C) 1990-2024 Free Software Foundation, Inc. |
| |
| Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com). |
| |
| This file is part of BFD, the Binary File Descriptor library. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| /* |
| SECTION |
| File caching |
| |
| The file caching mechanism is embedded within BFD and allows |
| the application to open as many BFDs as it wants without |
| regard to the underlying operating system's file descriptor |
| limit (often as low as 20 open files). The module in |
| <<cache.c>> maintains a least recently used list of |
| <<bfd_cache_max_open>> files, and exports the name |
| <<bfd_cache_lookup>>, which runs around and makes sure that |
| the required BFD is open. If not, then it chooses a file to |
| close, closes it and opens the one wanted, returning its file |
| handle. |
| |
| SUBSECTION |
| Caching functions |
| */ |
| |
| #include "sysdep.h" |
| #include "bfd.h" |
| #include "libbfd.h" |
| #include "libiberty.h" |
| |
| static FILE *_bfd_open_file_unlocked (bfd *abfd); |
| |
| /* In some cases we can optimize cache operation when reopening files. |
| For instance, a flush is entirely unnecessary if the file is already |
| closed, so a flush would use CACHE_NO_OPEN. Similarly, a seek using |
| SEEK_SET or SEEK_END need not first seek to the current position. |
| For stat we ignore seek errors, just in case the file has changed |
| while we weren't looking. If it has, then it's possible that the |
| file is shorter and we don't want a seek error to prevent us doing |
| the stat. */ |
| enum cache_flag { |
| CACHE_NORMAL = 0, |
| CACHE_NO_OPEN = 1, |
| CACHE_NO_SEEK = 2, |
| CACHE_NO_SEEK_ERROR = 4 |
| }; |
| |
| /* The maximum number of files which the cache will keep open at |
| one time. When needed call bfd_cache_max_open to initialize. */ |
| |
| static unsigned max_open_files = 0; |
| |
| /* Set max_open_files, if not already set, to 12.5% of the allowed open |
| file descriptors, but at least 10, and return the value. */ |
| static unsigned |
| bfd_cache_max_open (void) |
| { |
| if (max_open_files == 0) |
| { |
| int max; |
| #if defined(__sun) && !defined(__sparcv9) && !defined(__x86_64__) |
| /* PR ld/19260: 32-bit Solaris has very inelegant handling of the 255 |
| file descriptor limit. The problem is that setrlimit(2) can raise |
| RLIMIT_NOFILE to a value that is not supported by libc, resulting |
| in "Too many open files" errors. This can happen here even though |
| max_open_files is set to rlim.rlim_cur / 8. For example, if |
| a parent process has set rlim.rlim_cur to 65536, then max_open_files |
| will be computed as 8192. |
| |
| This check essentially reverts to the behavior from binutils 2.23.1 |
| for 32-bit Solaris only. (It is hoped that the 32-bit libc |
| limitation will be removed soon). 64-bit Solaris libc does not have |
| this limitation. */ |
| max = 16; |
| #else |
| #ifdef HAVE_GETRLIMIT |
| struct rlimit rlim; |
| |
| if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 |
| && rlim.rlim_cur != (rlim_t) RLIM_INFINITY) |
| max = rlim.rlim_cur / 8; |
| else |
| #endif |
| #ifdef _SC_OPEN_MAX |
| max = sysconf (_SC_OPEN_MAX) / 8; |
| #else |
| max = 10; |
| #endif |
| #endif /* not 32-bit Solaris */ |
| |
| max_open_files = max < 10 ? 10 : max; |
| } |
| |
| return max_open_files; |
| } |
| |
| /* The number of BFD files we have open. */ |
| |
| static unsigned open_files; |
| |
| /* Zero, or a pointer to the topmost BFD on the chain. This is |
| used by the <<bfd_cache_lookup>> macro in @file{libbfd.h} to |
| determine when it can avoid a function call. */ |
| |
| static bfd *bfd_last_cache = NULL; |
| |
| /* Insert a BFD into the cache. */ |
| |
| static void |
| insert (bfd *abfd) |
| { |
| if (bfd_last_cache == NULL) |
| { |
| abfd->lru_next = abfd; |
| abfd->lru_prev = abfd; |
| } |
| else |
| { |
| abfd->lru_next = bfd_last_cache; |
| abfd->lru_prev = bfd_last_cache->lru_prev; |
| abfd->lru_prev->lru_next = abfd; |
| abfd->lru_next->lru_prev = abfd; |
| } |
| bfd_last_cache = abfd; |
| } |
| |
| /* Remove a BFD from the cache. */ |
| |
| static void |
| snip (bfd *abfd) |
| { |
| abfd->lru_prev->lru_next = abfd->lru_next; |
| abfd->lru_next->lru_prev = abfd->lru_prev; |
| if (abfd == bfd_last_cache) |
| { |
| bfd_last_cache = abfd->lru_next; |
| if (abfd == bfd_last_cache) |
| bfd_last_cache = NULL; |
| } |
| } |
| |
| /* Close a BFD and remove it from the cache. */ |
| |
| static bool |
| bfd_cache_delete (bfd *abfd) |
| { |
| bool ret; |
| |
| if (fclose ((FILE *) abfd->iostream) == 0) |
| ret = true; |
| else |
| { |
| ret = false; |
| bfd_set_error (bfd_error_system_call); |
| } |
| |
| snip (abfd); |
| |
| abfd->iostream = NULL; |
| BFD_ASSERT (open_files > 0); |
| --open_files; |
| abfd->flags |= BFD_CLOSED_BY_CACHE; |
| |
| return ret; |
| } |
| |
| /* We need to open a new file, and the cache is full. Find the least |
| recently used cacheable BFD and close it. */ |
| |
| static bool |
| close_one (void) |
| { |
| register bfd *to_kill; |
| |
| if (bfd_last_cache == NULL) |
| to_kill = NULL; |
| else |
| { |
| for (to_kill = bfd_last_cache->lru_prev; |
| ! to_kill->cacheable; |
| to_kill = to_kill->lru_prev) |
| { |
| if (to_kill == bfd_last_cache) |
| { |
| to_kill = NULL; |
| break; |
| } |
| } |
| } |
| |
| if (to_kill == NULL) |
| { |
| /* There are no open cacheable BFD's. */ |
| return true; |
| } |
| |
| to_kill->where = _bfd_real_ftell ((FILE *) to_kill->iostream); |
| |
| return bfd_cache_delete (to_kill); |
| } |
| |
| /* Check to see if the required BFD is the same as the last one |
| looked up. If so, then it can use the stream in the BFD with |
| impunity, since it can't have changed since the last lookup; |
| otherwise, it has to perform the complicated lookup function. */ |
| |
| #define bfd_cache_lookup(x, flag) \ |
| ((x) == bfd_last_cache \ |
| ? (FILE *) (bfd_last_cache->iostream) \ |
| : bfd_cache_lookup_worker (x, flag)) |
| |
| /* A helper function that returns true if ABFD can possibly be cached |
| -- that is, whether bfd_cache_lookup_worker will accept it. */ |
| |
| static bool |
| possibly_cached (bfd *abfd) |
| { |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| return false; |
| if (abfd->my_archive != NULL |
| && !bfd_is_thin_archive (abfd->my_archive)) |
| return false; |
| return true; |
| } |
| |
| /* Called when the macro <<bfd_cache_lookup>> fails to find a |
| quick answer. Find a file descriptor for @var{abfd}. If |
| necessary, it open it. If there are already more than |
| <<bfd_cache_max_open>> files open, it tries to close one first, to |
| avoid running out of file descriptors. It will return NULL |
| if it is unable to (re)open the @var{abfd}. */ |
| |
| static FILE * |
| bfd_cache_lookup_worker (bfd *abfd, enum cache_flag flag) |
| { |
| if (!possibly_cached (abfd)) |
| abort (); |
| |
| /* If the BFD is being processed by bfd_check_format_matches, it |
| must already be open and won't be on the list. */ |
| if (abfd->in_format_matches) |
| { |
| if (abfd->iostream == NULL) |
| abort (); |
| return (FILE *) abfd->iostream; |
| } |
| |
| if (abfd->iostream != NULL) |
| { |
| /* Move the file to the start of the cache. */ |
| if (abfd != bfd_last_cache) |
| { |
| snip (abfd); |
| insert (abfd); |
| } |
| return (FILE *) abfd->iostream; |
| } |
| |
| if (flag & CACHE_NO_OPEN) |
| return NULL; |
| |
| if (_bfd_open_file_unlocked (abfd) == NULL) |
| ; |
| else if (!(flag & CACHE_NO_SEEK) |
| && _bfd_real_fseek ((FILE *) abfd->iostream, |
| abfd->where, SEEK_SET) != 0 |
| && !(flag & CACHE_NO_SEEK_ERROR)) |
| bfd_set_error (bfd_error_system_call); |
| else |
| return (FILE *) abfd->iostream; |
| |
| /* xgettext:c-format */ |
| _bfd_error_handler (_("reopening %pB: %s"), |
| abfd, bfd_errmsg (bfd_get_error ())); |
| return NULL; |
| } |
| |
| static file_ptr |
| cache_btell (struct bfd *abfd) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN); |
| if (f == NULL) |
| { |
| if (!bfd_unlock ()) |
| return -1; |
| return abfd->where; |
| } |
| file_ptr result = _bfd_real_ftell (f); |
| if (!bfd_unlock ()) |
| return -1; |
| return result; |
| } |
| |
| static int |
| cache_bseek (struct bfd *abfd, file_ptr offset, int whence) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| FILE *f = bfd_cache_lookup (abfd, whence != SEEK_CUR ? CACHE_NO_SEEK : CACHE_NORMAL); |
| if (f == NULL) |
| { |
| bfd_unlock (); |
| return -1; |
| } |
| int result = _bfd_real_fseek (f, offset, whence); |
| if (!bfd_unlock ()) |
| return -1; |
| return result; |
| } |
| |
| /* Note that archive entries don't have streams; they share their parent's. |
| This allows someone to play with the iostream behind BFD's back. |
| |
| Also, note that the origin pointer points to the beginning of a file's |
| contents (0 for non-archive elements). For archive entries this is the |
| first octet in the file, NOT the beginning of the archive header. */ |
| |
| static file_ptr |
| cache_bread_1 (FILE *f, void *buf, file_ptr nbytes) |
| { |
| file_ptr nread; |
| |
| #if defined (__VAX) && defined (VMS) |
| /* Apparently fread on Vax VMS does not keep the record length |
| information. */ |
| nread = read (fileno (f), buf, nbytes); |
| /* Set bfd_error if we did not read as much data as we expected. If |
| the read failed due to an error set the bfd_error_system_call, |
| else set bfd_error_file_truncated. */ |
| if (nread == (file_ptr)-1) |
| { |
| bfd_set_error (bfd_error_system_call); |
| return nread; |
| } |
| #else |
| nread = fread (buf, 1, nbytes, f); |
| /* Set bfd_error if we did not read as much data as we expected. If |
| the read failed due to an error set the bfd_error_system_call, |
| else set bfd_error_file_truncated. */ |
| if (nread < nbytes && ferror (f)) |
| { |
| bfd_set_error (bfd_error_system_call); |
| return nread; |
| } |
| #endif |
| if (nread < nbytes) |
| /* This may or may not be an error, but in case the calling code |
| bails out because of it, set the right error code. */ |
| bfd_set_error (bfd_error_file_truncated); |
| return nread; |
| } |
| |
| static file_ptr |
| cache_bread (struct bfd *abfd, void *buf, file_ptr nbytes) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| file_ptr nread = 0; |
| FILE *f; |
| |
| f = bfd_cache_lookup (abfd, CACHE_NORMAL); |
| if (f == NULL) |
| { |
| bfd_unlock (); |
| return -1; |
| } |
| |
| /* Some filesystems are unable to handle reads that are too large |
| (for instance, NetApp shares with oplocks turned off). To avoid |
| hitting this limitation, we read the buffer in chunks of 8MB max. */ |
| while (nread < nbytes) |
| { |
| const file_ptr max_chunk_size = 0x800000; |
| file_ptr chunk_size = nbytes - nread; |
| file_ptr chunk_nread; |
| |
| if (chunk_size > max_chunk_size) |
| chunk_size = max_chunk_size; |
| |
| chunk_nread = cache_bread_1 (f, (char *) buf + nread, chunk_size); |
| |
| /* Update the nread count. |
| |
| We just have to be careful of the case when cache_bread_1 returns |
| a negative count: If this is our first read, then set nread to |
| that negative count in order to return that negative value to the |
| caller. Otherwise, don't add it to our total count, or we would |
| end up returning a smaller number of bytes read than we actually |
| did. */ |
| if (nread == 0 || chunk_nread > 0) |
| nread += chunk_nread; |
| |
| if (chunk_nread < chunk_size) |
| break; |
| } |
| |
| if (!bfd_unlock ()) |
| return -1; |
| return nread; |
| } |
| |
| static file_ptr |
| cache_bwrite (struct bfd *abfd, const void *from, file_ptr nbytes) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| file_ptr nwrite; |
| FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL); |
| |
| if (f == NULL) |
| { |
| if (!bfd_unlock ()) |
| return -1; |
| return 0; |
| } |
| nwrite = fwrite (from, 1, nbytes, f); |
| if (nwrite < nbytes && ferror (f)) |
| { |
| bfd_set_error (bfd_error_system_call); |
| bfd_unlock (); |
| return -1; |
| } |
| if (!bfd_unlock ()) |
| return -1; |
| return nwrite; |
| } |
| |
| static int |
| cache_bclose (struct bfd *abfd) |
| { |
| /* No locking needed here, it's handled by the callee. */ |
| return bfd_cache_close (abfd) - 1; |
| } |
| |
| static int |
| cache_bflush (struct bfd *abfd) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| int sts; |
| FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN); |
| |
| if (f == NULL) |
| { |
| if (!bfd_unlock ()) |
| return -1; |
| return 0; |
| } |
| sts = fflush (f); |
| if (sts < 0) |
| bfd_set_error (bfd_error_system_call); |
| if (!bfd_unlock ()) |
| return -1; |
| return sts; |
| } |
| |
| static int |
| cache_bstat (struct bfd *abfd, struct stat *sb) |
| { |
| if (!bfd_lock ()) |
| return -1; |
| int sts; |
| FILE *f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR); |
| |
| if (f == NULL) |
| { |
| bfd_unlock (); |
| return -1; |
| } |
| sts = fstat (fileno (f), sb); |
| if (sts < 0) |
| bfd_set_error (bfd_error_system_call); |
| if (!bfd_unlock ()) |
| return -1; |
| return sts; |
| } |
| |
| static void * |
| cache_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED, |
| void *addr ATTRIBUTE_UNUSED, |
| size_t len ATTRIBUTE_UNUSED, |
| int prot ATTRIBUTE_UNUSED, |
| int flags ATTRIBUTE_UNUSED, |
| file_ptr offset ATTRIBUTE_UNUSED, |
| void **map_addr ATTRIBUTE_UNUSED, |
| size_t *map_len ATTRIBUTE_UNUSED) |
| { |
| void *ret = MAP_FAILED; |
| |
| if (!bfd_lock ()) |
| return ret; |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| abort (); |
| #ifdef HAVE_MMAP |
| else |
| { |
| uintptr_t pagesize_m1 = _bfd_pagesize_m1; |
| FILE *f; |
| file_ptr pg_offset; |
| size_t pg_len; |
| |
| f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR); |
| if (f == NULL) |
| { |
| bfd_unlock (); |
| return ret; |
| } |
| |
| /* Align. */ |
| pg_offset = offset & ~pagesize_m1; |
| pg_len = (len + (offset - pg_offset) + pagesize_m1) & ~pagesize_m1; |
| |
| ret = mmap (addr, pg_len, prot, flags, fileno (f), pg_offset); |
| if (ret == MAP_FAILED) |
| bfd_set_error (bfd_error_system_call); |
| else |
| { |
| *map_addr = ret; |
| *map_len = pg_len; |
| ret = (char *) ret + (offset & pagesize_m1); |
| } |
| } |
| #endif |
| |
| if (!bfd_unlock ()) |
| return MAP_FAILED; |
| return ret; |
| } |
| |
| static const struct bfd_iovec cache_iovec = |
| { |
| &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek, |
| &cache_bclose, &cache_bflush, &cache_bstat, &cache_bmmap |
| }; |
| |
| static bool |
| _bfd_cache_init_unlocked (bfd *abfd) |
| { |
| BFD_ASSERT (abfd->iostream != NULL); |
| if (open_files >= bfd_cache_max_open ()) |
| { |
| if (! close_one ()) |
| return false; |
| } |
| abfd->iovec = &cache_iovec; |
| insert (abfd); |
| abfd->flags &= ~BFD_CLOSED_BY_CACHE; |
| ++open_files; |
| return true; |
| } |
| |
| /* |
| INTERNAL_FUNCTION |
| bfd_cache_init |
| |
| SYNOPSIS |
| bool bfd_cache_init (bfd *abfd); |
| |
| DESCRIPTION |
| Add a newly opened BFD to the cache. |
| */ |
| |
| bool |
| bfd_cache_init (bfd *abfd) |
| { |
| if (!bfd_lock ()) |
| return false; |
| bool result = _bfd_cache_init_unlocked (abfd); |
| if (!bfd_unlock ()) |
| return false; |
| return result; |
| } |
| |
| static bool |
| _bfd_cache_close_unlocked (bfd *abfd) |
| { |
| /* Don't remove this test. bfd_reinit depends on it. */ |
| if (abfd->iovec != &cache_iovec) |
| return true; |
| |
| if (abfd->iostream == NULL) |
| /* Previously closed. */ |
| return true; |
| |
| /* Note: no locking needed in this function, as it is handled by |
| bfd_cache_delete. */ |
| return bfd_cache_delete (abfd); |
| } |
| |
| /* |
| FUNCTION |
| bfd_cache_close |
| |
| SYNOPSIS |
| bool bfd_cache_close (bfd *abfd); |
| |
| DESCRIPTION |
| Remove the BFD @var{abfd} from the cache. If the attached file is open, |
| then close it too. |
| |
| <<FALSE>> is returned if closing the file fails, <<TRUE>> is |
| returned if all is well. |
| */ |
| |
| bool |
| bfd_cache_close (bfd *abfd) |
| { |
| if (!bfd_lock ()) |
| return false; |
| bool result = _bfd_cache_close_unlocked (abfd); |
| if (!bfd_unlock ()) |
| return false; |
| return result; |
| } |
| |
| /* |
| FUNCTION |
| bfd_cache_close_all |
| |
| SYNOPSIS |
| bool bfd_cache_close_all (void); |
| |
| DESCRIPTION |
| Remove all BFDs from the cache. If the attached file is open, |
| then close it too. Note - despite its name this function will |
| close a BFD even if it is not marked as being cacheable, ie |
| even if bfd_get_cacheable() returns false. |
| |
| <<FALSE>> is returned if closing one of the file fails, <<TRUE>> is |
| returned if all is well. |
| */ |
| |
| bool |
| bfd_cache_close_all (void) |
| { |
| bool ret = true; |
| |
| if (!bfd_lock ()) |
| return false; |
| while (bfd_last_cache != NULL) |
| { |
| bfd *prev_bfd_last_cache = bfd_last_cache; |
| |
| ret &= _bfd_cache_close_unlocked (bfd_last_cache); |
| |
| /* Stop a potential infinite loop should bfd_cache_close() |
| not update bfd_last_cache. */ |
| if (bfd_last_cache == prev_bfd_last_cache) |
| break; |
| } |
| |
| if (!bfd_unlock ()) |
| return false; |
| return ret; |
| } |
| |
| /* |
| INTERNAL_FUNCTION |
| bfd_cache_set_uncloseable |
| |
| SYNOPSIS |
| bool bfd_cache_set_uncloseable (bfd *abfd, bool value, bool *old); |
| |
| DESCRIPTION |
| Internal function to mark ABFD as either closeable or not. |
| This is used by bfd_check_format_matches to avoid races |
| where bfd_cache_close_all is called in another thread. |
| VALUE is true to mark the BFD as temporarily uncloseable |
| by the cache; false to mark it as closeable once again. |
| OLD, if non-NULL, is set to the previous value of the flag. |
| Returns false on error, true on success. |
| */ |
| |
| bool |
| bfd_cache_set_uncloseable (bfd *abfd, bool value, bool *old) |
| { |
| bool result = true; |
| |
| if (!bfd_lock ()) |
| return false; |
| if (old != NULL) |
| *old = abfd->in_format_matches; |
| |
| /* Only perform any action when the state changes,and only when this |
| BFD is actually using the cache. */ |
| if (value != abfd->in_format_matches |
| && abfd->iovec == &cache_iovec |
| && possibly_cached (abfd)) |
| { |
| if (value) |
| { |
| /* Marking as uncloseable for the first time. Ensure the |
| file is open, and remove from the cache list. */ |
| FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL); |
| if (f == NULL) |
| result = false; |
| else |
| snip (abfd); |
| } |
| else |
| { |
| /* Mark as closeable again. */ |
| insert (abfd); |
| } |
| |
| abfd->in_format_matches = value; |
| } |
| |
| if (!bfd_unlock ()) |
| return false; |
| return result; |
| } |
| |
| /* |
| FUNCTION |
| bfd_cache_size |
| |
| SYNOPSIS |
| unsigned bfd_cache_size (void); |
| |
| DESCRIPTION |
| Return the number of open files in the cache. |
| */ |
| |
| unsigned |
| bfd_cache_size (void) |
| { |
| return open_files; |
| } |
| |
| static FILE * |
| _bfd_open_file_unlocked (bfd *abfd) |
| { |
| abfd->cacheable = true; /* Allow it to be closed later. */ |
| |
| if (open_files >= bfd_cache_max_open ()) |
| { |
| if (! close_one ()) |
| return NULL; |
| } |
| |
| switch (abfd->direction) |
| { |
| case read_direction: |
| case no_direction: |
| abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd), FOPEN_RB); |
| break; |
| case both_direction: |
| case write_direction: |
| if (abfd->opened_once) |
| { |
| abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd), |
| FOPEN_RUB); |
| if (abfd->iostream == NULL) |
| abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd), |
| FOPEN_WUB); |
| } |
| else |
| { |
| /* Create the file. |
| |
| Some operating systems won't let us overwrite a running |
| binary. For them, we want to unlink the file first. |
| |
| However, gcc 2.95 will create temporary files using |
| O_EXCL and tight permissions to prevent other users from |
| substituting other .o files during the compilation. gcc |
| will then tell the assembler to use the newly created |
| file as an output file. If we unlink the file here, we |
| open a brief window when another user could still |
| substitute a file. |
| |
| So we unlink the output file if and only if it has |
| non-zero size. */ |
| #ifndef __MSDOS__ |
| /* Don't do this for MSDOS: it doesn't care about overwriting |
| a running binary, but if this file is already open by |
| another BFD, we will be in deep trouble if we delete an |
| open file. In fact, objdump does just that if invoked with |
| the --info option. */ |
| struct stat s; |
| |
| if (stat (bfd_get_filename (abfd), &s) == 0 && s.st_size != 0) |
| unlink_if_ordinary (bfd_get_filename (abfd)); |
| #endif |
| abfd->iostream = _bfd_real_fopen (bfd_get_filename (abfd), |
| FOPEN_WUB); |
| abfd->opened_once = true; |
| } |
| break; |
| } |
| |
| if (abfd->iostream == NULL) |
| bfd_set_error (bfd_error_system_call); |
| else |
| { |
| if (! _bfd_cache_init_unlocked (abfd)) |
| return NULL; |
| } |
| |
| return (FILE *) abfd->iostream; |
| } |
| |
| /* |
| INTERNAL_FUNCTION |
| bfd_open_file |
| |
| SYNOPSIS |
| FILE* bfd_open_file (bfd *abfd); |
| |
| DESCRIPTION |
| Call the OS to open a file for @var{abfd}. Return the <<FILE *>> |
| (possibly <<NULL>>) that results from this operation. Set up the |
| BFD so that future accesses know the file is open. If the <<FILE *>> |
| returned is <<NULL>>, then it won't have been put in the |
| cache, so it won't have to be removed from it. |
| */ |
| |
| FILE * |
| bfd_open_file (bfd *abfd) |
| { |
| if (!bfd_lock ()) |
| return NULL; |
| FILE *result = _bfd_open_file_unlocked (abfd); |
| if (!bfd_unlock ()) |
| return NULL; |
| return result; |
| } |