-
/* BFD library -- caching of file descriptors.
- Copyright (C) 1990-1991 Free Software Foundation, Inc.
+
+ Copyright 1990, 1991, 1992, 1993, 1994, 1996, 2000, 2001, 2002,
+ 2003, 2004 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.
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. */
+Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
/*
SECTION
- File Caching
+ File caching
The file caching mechanism is embedded within BFD and allows
the application to open as many BFDs as it wants without
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
+ <<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.
+ handle.
*/
-/* $Id$ */
-
#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
+#include "libiberty.h"
+
+static bfd_boolean bfd_cache_delete (bfd *);
+
+
+static file_ptr
+cache_btell (struct bfd *abfd)
+{
+ return real_ftell (bfd_cache_lookup (abfd));
+}
+
+static int
+cache_bseek (struct bfd *abfd, file_ptr offset, int whence)
+{
+ return real_fseek (bfd_cache_lookup (abfd), 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 (struct bfd *abfd, void *buf, file_ptr nbytes)
+{
+ file_ptr nread;
+ /* FIXME - this looks like an optimization, but it's really to cover
+ up for a feature of some OSs (not solaris - sigh) that
+ ld/pe-dll.c takes advantage of (apparently) when it creates BFDs
+ internally and tries to link against them. BFD seems to be smart
+ enough to realize there are no symbol records in the "file" that
+ doesn't exist but attempts to read them anyway. On Solaris,
+ attempting to read zero bytes from a NULL file results in a core
+ dump, but on other platforms it just returns zero bytes read.
+ This makes it to something reasonable. - DJ */
+ if (nbytes == 0)
+ return 0;
+
+#if defined (__VAX) && defined (VMS)
+ /* Apparently fread on Vax VMS does not keep the record length
+ information. */
+ nread = read (fileno (bfd_cache_lookup (abfd)), 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 -1;
+ }
+#else
+ nread = fread (buf, 1, nbytes, bfd_cache_lookup (abfd));
+ /* 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 (bfd_cache_lookup (abfd)))
+ {
+ bfd_set_error (bfd_error_system_call);
+ return -1;
+ }
+#endif
+ return nread;
+}
+
+static file_ptr
+cache_bwrite (struct bfd *abfd, const void *where, file_ptr nbytes)
+{
+ file_ptr nwrite = fwrite (where, 1, nbytes, bfd_cache_lookup (abfd));
+ if (nwrite < nbytes && ferror (bfd_cache_lookup (abfd)))
+ {
+ bfd_set_error (bfd_error_system_call);
+ return -1;
+ }
+ return nwrite;
+}
+
+static int
+cache_bclose (struct bfd *abfd)
+{
+ return bfd_cache_close (abfd);
+}
+
+static int
+cache_bflush (struct bfd *abfd)
+{
+ int sts = fflush (bfd_cache_lookup (abfd));
+ if (sts < 0)
+ bfd_set_error (bfd_error_system_call);
+ return sts;
+}
+
+static int
+cache_bstat (struct bfd *abfd, struct stat *sb)
+{
+ int sts = fstat (fileno (bfd_cache_lookup (abfd)), sb);
+ if (sts < 0)
+ bfd_set_error (bfd_error_system_call);
+ return sts;
+}
+
+static const struct bfd_iovec cache_iovec = {
+ &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek,
+ &cache_bclose, &cache_bflush, &cache_bstat
+};
/*
INTERNAL_FUNCTION
BFD_CACHE_MAX_OPEN macro
DESCRIPTION
- The maxiumum number of files which the cache will keep open at
+ The maximum number of files which the cache will keep open at
one time.
.#define BFD_CACHE_MAX_OPEN 10
*/
+/* The number of BFD files we have open. */
static int open_files;
-static bfd *cache_sentinel; /* Chain of BFDs with active fds we've
- opened */
-
/*
INTERNAL_FUNCTION
bfd_last_cache
bfd *bfd_last_cache;
/*
- * INTERNAL_FUNCTION
- * bfd_cache_lookup
- *
- * DESCRIPTION
- * 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))
- *
- *
- */
+ INTERNAL_FUNCTION
+ bfd_cache_lookup
+
+ DESCRIPTION
+ 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) \
+ . ((x) == bfd_last_cache ? \
+ . (FILE *) (bfd_last_cache->iostream): \
+ . bfd_cache_lookup_worker (x))
-static void bfd_cache_delete();
+ */
+/* Insert a BFD into the cache. */
static void
-DEFUN_VOID(close_one)
+insert (bfd *abfd)
{
- 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 (bfd_last_cache == NULL)
+ {
+ abfd->lru_next = abfd;
+ abfd->lru_prev = abfd;
}
-
- kill->where = ftell((FILE *)(kill->iostream));
- bfd_cache_delete(kill);
+ 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;
}
-/* Cuts the BFD abfd out of the chain in the cache */
-static void
-DEFUN(snip,(abfd),
- bfd *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 (cache_sentinel == abfd) cache_sentinel = (bfd *)NULL;
+ 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;
+ }
}
-static void
-DEFUN(bfd_cache_delete,(abfd),
- bfd *abfd)
+/* 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)
{
- fclose ((FILE *)(abfd->iostream));
- snip (abfd);
- abfd->iostream = NULL;
- open_files--;
- bfd_last_cache = 0;
+ register bfd *kill;
+
+ if (bfd_last_cache == NULL)
+ kill = NULL;
+ else
+ {
+ for (kill = bfd_last_cache->lru_prev;
+ ! kill->cacheable;
+ kill = kill->lru_prev)
+ {
+ if (kill == bfd_last_cache)
+ {
+ kill = NULL;
+ break;
+ }
+ }
+ }
+
+ if (kill == NULL)
+ {
+ /* There are no open cacheable BFD's. */
+ return TRUE;
+ }
+
+ kill->where = real_ftell ((FILE *) kill->iostream);
+
+ return bfd_cache_delete (kill);
}
-
-static bfd *
-DEFUN(insert,(x,y),
- bfd *x AND
- bfd *y)
+
+/* Close a BFD and remove it from the cache. */
+
+static bfd_boolean
+bfd_cache_delete (bfd *abfd)
{
- 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;
+ bfd_boolean ret;
+
+ if (fclose ((FILE *) abfd->iostream) == 0)
+ ret = TRUE;
+ else
+ {
+ ret = FALSE;
+ bfd_set_error (bfd_error_system_call);
+ }
+
+ snip (abfd);
+
+ abfd->iostream = NULL;
+ --open_files;
+
+ return ret;
}
-\f
/*
INTERNAL_FUNCTION
bfd_cache_init
SYNOPSIS
- void bfd_cache_init (bfd *);
+ bfd_boolean bfd_cache_init (bfd *abfd);
DESCRIPTION
- Initialize a BFD by putting it on the cache LRU.
+ Add a newly opened BFD to the cache.
*/
-void
-DEFUN(bfd_cache_init,(abfd),
- bfd *abfd)
+bfd_boolean
+bfd_cache_init (bfd *abfd)
{
- cache_sentinel = insert(abfd, cache_sentinel);
+ BFD_ASSERT (abfd->iostream != NULL);
+ if (open_files >= BFD_CACHE_MAX_OPEN)
+ {
+ if (! close_one ())
+ return FALSE;
+ }
+ abfd->iovec = &cache_iovec;
+ insert (abfd);
+ ++open_files;
+ return TRUE;
}
-
/*
INTERNAL_FUNCTION
bfd_cache_close
+SYNOPSIS
+ bfd_boolean bfd_cache_close (bfd *abfd);
+
DESCRIPTION
- Remove the BFD from the cache. If the attached file is open,
+ 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
- void bfd_cache_close (bfd *);
+ 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.
*/
-void
-DEFUN(bfd_cache_close,(abfd),
- bfd *abfd)
+
+bfd_boolean
+bfd_cache_close_all ()
{
- /* If this file is open then remove from the chain */
- if (abfd->iostream)
- {
- bfd_cache_delete(abfd);
- }
+ 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 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
+ 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.
-
-SYNOPSIS
- FILE* bfd_open_file(bfd *);
*/
FILE *
-DEFUN(bfd_open_file, (abfd),
- bfd *abfd)
+bfd_open_file (bfd *abfd)
{
- 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, FOPEN_RB);
- break;
- case both_direction:
- case write_direction:
- if (abfd->opened_once == true) {
- abfd->iostream = (char *) fopen(abfd->filename, FOPEN_RUB);
- if (!abfd->iostream) {
- abfd->iostream = (char *) fopen(abfd->filename, FOPEN_WUB);
- }
- } else {
- /*open for creat */
- abfd->iostream = (char *) fopen(abfd->filename, FOPEN_WB);
- abfd->opened_once = true;
+ abfd->cacheable = TRUE; /* Allow it to be closed later. */
+
+ if (open_files >= BFD_CACHE_MAX_OPEN)
+ {
+ if (! close_one ())
+ return NULL;
}
- break;
- }
- if (abfd->iostream) {
- open_files++;
- bfd_cache_init (abfd);
- }
+ switch (abfd->direction)
+ {
+ case read_direction:
+ case no_direction:
+ abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RB);
+ break;
+ case both_direction:
+ case write_direction:
+ if (abfd->opened_once)
+ {
+ abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RUB);
+ if (abfd->iostream == NULL)
+ abfd->iostream = (PTR) fopen (abfd->filename, 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 (abfd->filename, &s) == 0 && s.st_size != 0)
+ unlink_if_ordinary (abfd->filename);
+#endif
+ abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_WUB);
+ abfd->opened_once = TRUE;
+ }
+ break;
+ }
- return (FILE *)(abfd->iostream);
+ if (abfd->iostream != NULL)
+ {
+ if (! bfd_cache_init (abfd))
+ return NULL;
+ }
+
+ return (FILE *) abfd->iostream;
}
/*
INTERNAL_FUNCTION
bfd_cache_lookup_worker
-DESCRIPTION
- Called when the macro <<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.
-
SYNOPSIS
- FILE *bfd_cache_lookup_worker(bfd *);
+ FILE *bfd_cache_lookup_worker (bfd *abfd);
+DESCRIPTION
+ 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 abort rather than
+ returning NULL if it is unable to (re)open the @var{abfd}.
*/
FILE *
-DEFUN(bfd_cache_lookup_worker,(abfd),
- bfd *abfd)
+bfd_cache_lookup_worker (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 */
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+
+ if (abfd->my_archive)
+ abfd = abfd->my_archive;
+
+ if (abfd->iostream != NULL)
+ {
+ /* Move the file to the start of the cache. */
+ if (abfd != bfd_last_cache)
+ {
snip (abfd);
- cache_sentinel = insert(abfd, cache_sentinel);
+ insert (abfd);
}
- }
- /* 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
+ {
+ if (bfd_open_file (abfd) == NULL
+ || abfd->where != (unsigned long) abfd->where
+ || real_fseek ((FILE *) abfd->iostream, abfd->where, SEEK_SET) != 0)
+ abort ();
+ }
- BFD_ASSERT(bfd_open_file (abfd) != (FILE *)NULL) ;
- fseek((FILE *)(abfd->iostream), abfd->where, false);
- }
- bfd_last_cache = abfd;
- return (FILE *)(abfd->iostream);
+ return (FILE *) abfd->iostream;
}
projects / deliverable / binutils-gdb.git / blobdiff