/* BFD library -- caching of file descriptors.
- Copyright (C) 1990-1991 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.
+ Copyright (C) 1990-2020 Free Software Foundation, Inc.
-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 2 of the License, or
-(at your option) any later version.
+ Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com).
-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.
+ 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
+*/
-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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+#include "sysdep.h"
+#include "bfd.h"
+#include "libbfd.h"
+#include "libiberty.h"
+
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#endif
+
+/* 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 int 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 int
+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;
+ }
-/*doc*
-@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).
+ return max_open_files;
+}
-The module in @code{cache.c} maintains a least recently used list of
-@code{BFD_CACHE_MAX_OPEN} files, and exports the name
-@code{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.
+/* The number of BFD files we have open. */
-*/
+static int 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;
-/* $Id$ */
-#include <sysdep.h>
-#include "bfd.h"
-#include "libbfd.h"
+/* 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;
+}
-/*proto-internal* BFD_CACHE_MAX_OPEN
-The maxiumum number of files which the cache will keep open at one
-time.
-*+
-#define BFD_CACHE_MAX_OPEN 10
-*-
+/* 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 int open_files;
+static bfd_boolean
+bfd_cache_delete (bfd *abfd)
+{
+ bfd_boolean ret;
-static bfd *cache_sentinel; /* Chain of BFDs with active fds we've
- opened */
+ if (fclose ((FILE *) abfd->iostream) == 0)
+ ret = TRUE;
+ else
+ {
+ ret = FALSE;
+ bfd_set_error (bfd_error_system_call);
+ }
-/*proto-internal* bfd_last_cache
-Zero, or a pointer to the topmost BFD on the chain. This is used by
-the @code{bfd_cache_lookup} macro in @file{libbfd.h} to determine when
-it can avoid a function call.
-*+
-extern bfd *bfd_last_cache;
-*-
+ snip (abfd);
-*/
+ abfd->iostream = NULL;
+ --open_files;
-bfd *bfd_last_cache;
+ return ret;
+}
-/*proto-internal* bfd_cache_lookup
-Checks to see if the required BFD is the same as the last one looked
-up. If so then it can use the iostream 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) \
- ((x)==bfd_last_cache? \
- (FILE*)(bfd_last_cache->iostream): \
- bfd_cache_lookup_worker(x))
+/* We need to open a new file, and the cache is full. Find the least
+ recently used cacheable BFD and close it. */
-*-
+static bfd_boolean
+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;
+ }
+ }
+ }
-static void bfd_cache_delete();
+ if (to_kill == NULL)
+ {
+ /* There are no open cacheable BFD's. */
+ return TRUE;
+ }
+ to_kill->where = _bfd_real_ftell ((FILE *) to_kill->iostream);
-static void
-DEFUN_VOID(close_one)
+ 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))
+
+/* 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)
{
- bfd *kill = cache_sentinel;
- if (kill == 0) /* Nothing in the cache */
- return ;
-
- /* We can only close files that want to play this game. */
- while (!kill->cacheable) {
- kill = kill->lru_prev;
- if (kill == cache_sentinel) /* Nobody wants to play */
- return ;
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+
+ if (abfd->my_archive != NULL
+ && !bfd_is_thin_archive (abfd->my_archive))
+ abort ();
+
+ 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;
}
- kill->where = ftell((FILE *)(kill->iostream));
- bfd_cache_delete(kill);
+ if (flag & CACHE_NO_OPEN)
+ return NULL;
+
+ if (bfd_open_file (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\n"),
+ abfd, bfd_errmsg (bfd_get_error ()));
+ return NULL;
}
-/* Cuts the BFD abfd out of the chain in the cache */
-static void
-DEFUN(snip,(abfd),
- bfd *abfd)
+static file_ptr
+cache_btell (struct bfd *abfd)
{
- abfd->lru_prev->lru_next = abfd->lru_next;
- abfd->lru_next->lru_prev = abfd->lru_prev;
- if (cache_sentinel == abfd) cache_sentinel = (bfd *)NULL;
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
+ if (f == NULL)
+ return abfd->where;
+ return _bfd_real_ftell (f);
}
-static void
-DEFUN(bfd_cache_delete,(abfd),
- bfd *abfd)
+static int
+cache_bseek (struct bfd *abfd, file_ptr offset, int whence)
{
- fclose ((FILE *)(abfd->iostream));
- snip (abfd);
- abfd->iostream = NULL;
- open_files--;
- bfd_last_cache = 0;
+ FILE *f = bfd_cache_lookup (abfd, whence != SEEK_CUR ? CACHE_NO_SEEK : CACHE_NORMAL);
+ if (f == NULL)
+ return -1;
+ return _bfd_real_fseek (f, offset, whence);
+}
+
+/* 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)
+{
+ file_ptr nread = 0;
+ FILE *f;
+
+ f = bfd_cache_lookup (abfd, CACHE_NORMAL);
+ if (f == NULL)
+ 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;
+ }
+
+ return nread;
}
-
-static bfd *
-DEFUN(insert,(x,y),
- bfd *x AND
- bfd *y)
+
+static file_ptr
+cache_bwrite (struct bfd *abfd, const void *from, file_ptr nbytes)
{
- if (y) {
- x->lru_next = y;
- x->lru_prev = y->lru_prev;
- y->lru_prev->lru_next = x;
- y->lru_prev = x;
-
- }
- else {
- x->lru_prev = x;
- x->lru_next = x;
- }
- return x;
+ file_ptr nwrite;
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL);
+
+ if (f == NULL)
+ return 0;
+ nwrite = fwrite (from, 1, nbytes, f);
+ if (nwrite < nbytes && ferror (f))
+ {
+ bfd_set_error (bfd_error_system_call);
+ return -1;
+ }
+ return nwrite;
}
-\f
-/*proto-internal*
-*i bfd_cache_init
-Initialize a BFD by putting it on the cache LRU.
-*; PROTO(void, bfd_cache_init, (bfd *));
-*-*/
+static int
+cache_bclose (struct bfd *abfd)
+{
+ return bfd_cache_close (abfd) - 1;
+}
-void
-DEFUN(bfd_cache_init,(abfd),
- bfd *abfd)
+static int
+cache_bflush (struct bfd *abfd)
{
- cache_sentinel = insert(abfd, cache_sentinel);
+ int sts;
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
+
+ if (f == NULL)
+ return 0;
+ sts = fflush (f);
+ if (sts < 0)
+ bfd_set_error (bfd_error_system_call);
+ return sts;
}
+static int
+cache_bstat (struct bfd *abfd, struct stat *sb)
+{
+ int sts;
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
+
+ if (f == NULL)
+ return -1;
+ sts = fstat (fileno (f), sb);
+ if (sts < 0)
+ bfd_set_error (bfd_error_system_call);
+ return sts;
+}
-/*proto-internal*
-*i bfd_cache_close
-Remove the BFD from the cache. If the attatched file is open, then close it too.
-*; PROTO(void, bfd_cache_close, (bfd *));
-*-*/
-void
-DEFUN(bfd_cache_close,(abfd),
- bfd *abfd)
+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)
{
- /* If this file is open then remove from the chain */
- if (abfd->iostream)
+ void *ret = (void *) -1;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+#ifdef HAVE_MMAP
+ else
{
- bfd_cache_delete(abfd);
+ static uintptr_t pagesize_m1;
+ FILE *f;
+ file_ptr pg_offset;
+ bfd_size_type pg_len;
+
+ f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
+ if (f == NULL)
+ return ret;
+
+ if (pagesize_m1 == 0)
+ pagesize_m1 = getpagesize () - 1;
+
+ /* 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 == (void *) -1)
+ bfd_set_error (bfd_error_system_call);
+ else
+ {
+ *map_addr = ret;
+ *map_len = pg_len;
+ ret = (char *) ret + (offset & pagesize_m1);
+ }
}
+#endif
+
+ return ret;
}
-/*proto-internal*
-*i bfd_open_file
-Call the OS to open a file for this BFD. Returns the FILE *
-(possibly null) that results from this operation. Sets up the
-BFD so that future accesses know the file is open. If the FILE *
-returned is null, then there is won't have been put in the cache, so
-it won't have to be removed from it.
-*; PROTO(FILE *, bfd_open_file, (bfd *));
-*-*/
-FILE *
-DEFUN(bfd_open_file, (abfd),
- bfd *abfd)
+static const struct bfd_iovec cache_iovec =
{
- abfd->cacheable = true; /* Allow it to be closed later. */
- if(open_files >= BFD_CACHE_MAX_OPEN) {
- close_one();
- }
- switch (abfd->direction) {
- case read_direction:
- case no_direction:
- abfd->iostream = (char *) fopen(abfd->filename, "r");
- break;
- case both_direction:
- case write_direction:
- if (abfd->opened_once == true) {
- abfd->iostream = (char *) fopen(abfd->filename, "r+");
- if (!abfd->iostream) {
- abfd->iostream = (char *) fopen(abfd->filename, "w+");
- }
- } else {
- /*open for creat */
- abfd->iostream = (char *) fopen(abfd->filename, "w");
- abfd->opened_once = true;
+ &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek,
+ &cache_bclose, &cache_bflush, &cache_bstat, &cache_bmmap
+};
+
+/*
+INTERNAL_FUNCTION
+ bfd_cache_init
+
+SYNOPSIS
+ bfd_boolean bfd_cache_init (bfd *abfd);
+
+DESCRIPTION
+ Add a newly opened BFD to the cache.
+*/
+
+bfd_boolean
+bfd_cache_init (bfd *abfd)
+{
+ BFD_ASSERT (abfd->iostream != NULL);
+ if (open_files >= bfd_cache_max_open ())
+ {
+ if (! close_one ())
+ return FALSE;
}
- break;
- }
- if (abfd->iostream) {
- open_files++;
- bfd_cache_init (abfd);
- }
-
- return (FILE *)(abfd->iostream);
+ abfd->iovec = &cache_iovec;
+ insert (abfd);
+ ++open_files;
+ return TRUE;
}
-/*proto-internal*
-*i bfd_cache_lookup_worker
-Called when the macro @code{bfd_cache_lookup} fails to find a quick
-answer. Finds a file descriptor for this BFD. If necessary, it open it.
-If there are already more than BFD_CACHE_MAX_OPEN files open, it trys to close
-one first, to avoid running out of file descriptors.
-*; PROTO(FILE *, bfd_cache_lookup_worker, (bfd *));
+/*
+INTERNAL_FUNCTION
+ bfd_cache_close
+
+SYNOPSIS
+ bfd_boolean bfd_cache_close (bfd *abfd);
-*-*/
+DESCRIPTION
+ Remove the BFD @var{abfd} from the cache. If the attached file is open,
+ then close it too.
+
+RETURNS
+ <<FALSE>> is returned if closing the file fails, <<TRUE>> is
+ returned if all is well.
+*/
+
+bfd_boolean
+bfd_cache_close (bfd *abfd)
+{
+ if (abfd->iovec != &cache_iovec)
+ return TRUE;
+
+ if (abfd->iostream == NULL)
+ /* Previously closed. */
+ return TRUE;
+
+ return bfd_cache_delete (abfd);
+}
+
+/*
+FUNCTION
+ bfd_cache_close_all
+
+SYNOPSIS
+ bfd_boolean bfd_cache_close_all (void);
+
+DESCRIPTION
+ Remove all BFDs from the cache. If the attached file is open,
+ then close it too.
+
+RETURNS
+ <<FALSE>> is returned if closing one of the file fails, <<TRUE>> is
+ returned if all is well.
+*/
+
+bfd_boolean
+bfd_cache_close_all (void)
+{
+ bfd_boolean ret = TRUE;
+
+ while (bfd_last_cache != NULL)
+ ret &= bfd_cache_close (bfd_last_cache);
+
+ return ret;
+}
+
+/*
+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 *
-DEFUN(bfd_cache_lookup_worker,(abfd),
- bfd *abfd)
+bfd_open_file (bfd *abfd)
{
- if (abfd->my_archive)
- {
- abfd = abfd->my_archive;
- }
- /* Is this file already open .. if so then quick exit */
- if (abfd->iostream)
- {
- if (abfd != cache_sentinel) {
- /* Place onto head of lru chain */
- snip (abfd);
- cache_sentinel = insert(abfd, cache_sentinel);
+ 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);
}
- }
- /* This is a BFD without a stream -
- so it must have been closed or never opened.
- find an empty cache entry and use it. */
- else
- {
-
- if (open_files >= BFD_CACHE_MAX_OPEN)
- {
- close_one();
- }
+ 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;
+ }
- BFD_ASSERT(bfd_open_file (abfd) != (FILE *)NULL) ;
- fseek((FILE *)(abfd->iostream), abfd->where, false);
- }
- bfd_last_cache = abfd;
- return (FILE *)(abfd->iostream);
+ if (abfd->iostream == NULL)
+ bfd_set_error (bfd_error_system_call);
+ else
+ {
+ if (! bfd_cache_init (abfd))
+ return NULL;
+ }
+
+ return (FILE *) abfd->iostream;
}
projects / deliverable / binutils-gdb.git / blobdiff