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Diffstat (limited to 'binutils-2.24/bfd/cache.c')
| -rw-r--r-- | binutils-2.24/bfd/cache.c | 645 |
1 files changed, 0 insertions, 645 deletions
diff --git a/binutils-2.24/bfd/cache.c b/binutils-2.24/bfd/cache.c deleted file mode 100644 index 4d46936b..00000000 --- a/binutils-2.24/bfd/cache.c +++ /dev/null @@ -1,645 +0,0 @@ -/* BFD library -- caching of file descriptors. - - Copyright 1990, 1991, 1992, 1993, 1994, 1996, 2000, 2001, 2002, - 2003, 2004, 2005, 2007, 2008, 2009 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" -#include "bfd_stdint.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; -#ifdef HAVE_GETRLIMIT - struct rlimit rlim; - if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 - && rlim.rlim_cur != RLIM_INFINITY) - max = rlim.rlim_cur / 8; - else -#endif /* HAVE_GETRLIMIT */ -#ifdef _SC_OPEN_MAX - max = sysconf (_SC_OPEN_MAX) / 8; -#else - max = 10; -#endif /* _SC_OPEN_MAX */ - max_open_files = max < 10 ? 10 : max; - } - - return max_open_files; -} - -/* 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; - -/* 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 bfd_boolean -bfd_cache_delete (bfd *abfd) -{ - 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; -} - -/* 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; - } - } - } - - if (to_kill == NULL) - { - /* There are no open cacheable BFD's. */ - return TRUE; - } - - to_kill->where = 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)) - -/* 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 *orig_bfd = abfd; - if ((abfd->flags & BFD_IN_MEMORY) != 0) - abort (); - - while (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); - insert (abfd); - } - return (FILE *) abfd->iostream; - } - - if (flag & CACHE_NO_OPEN) - return NULL; - - if (bfd_open_file (abfd) == NULL) - ; - else if (!(flag & CACHE_NO_SEEK) - && 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; - - (*_bfd_error_handler) (_("reopening %B: %s\n"), - orig_bfd, bfd_errmsg (bfd_get_error ())); - return NULL; -} - -static file_ptr -cache_btell (struct bfd *abfd) -{ - FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN); - if (f == NULL) - return abfd->where; - return real_ftell (f); -} - -static int -cache_bseek (struct bfd *abfd, file_ptr offset, int whence) -{ - FILE *f = bfd_cache_lookup (abfd, whence != SEEK_CUR ? CACHE_NO_SEEK : CACHE_NORMAL); - if (f == NULL) - return -1; - return 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 (struct bfd *abfd, void *buf, file_ptr nbytes) -{ - FILE *f; - 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; - - f = bfd_cache_lookup (abfd, CACHE_NORMAL); - if (f == NULL) - return 0; - -#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 -1; - } -#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 -1; - } -#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; - - /* 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 (abfd, (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 file_ptr -cache_bwrite (struct bfd *abfd, const void *where, file_ptr nbytes) -{ - file_ptr nwrite; - FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL); - - if (f == NULL) - return 0; - nwrite = fwrite (where, 1, nbytes, f); - if (nwrite < nbytes && ferror (f)) - { - bfd_set_error (bfd_error_system_call); - return -1; - } - return nwrite; -} - -static int -cache_bclose (struct bfd *abfd) -{ - return bfd_cache_close (abfd) - 1; -} - -static int -cache_bflush (struct bfd *abfd) -{ - 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; -} - -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) -{ - void *ret = (void *) -1; - - if ((abfd->flags & BFD_IN_MEMORY) != 0) - abort (); -#ifdef HAVE_MMAP - else - { - 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; - - /* Handle archive members. */ - if (abfd->my_archive != NULL) - offset += abfd->origin; - - /* 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; -} - -static const struct bfd_iovec cache_iovec = -{ - &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; - } - 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 @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 () -{ - 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 * -bfd_open_file (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 = real_fopen (abfd->filename, FOPEN_RB); - break; - case both_direction: - case write_direction: - if (abfd->opened_once) - { - abfd->iostream = real_fopen (abfd->filename, FOPEN_RUB); - if (abfd->iostream == NULL) - abfd->iostream = real_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 = real_fopen (abfd->filename, FOPEN_WUB); - abfd->opened_once = TRUE; - } - break; - } - - if (abfd->iostream == NULL) - bfd_set_error (bfd_error_system_call); - else - { - if (! bfd_cache_init (abfd)) - return NULL; - } - - return (FILE *) abfd->iostream; -} |