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-rw-r--r--bfd/bfdio.c436
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diff --git a/bfd/bfdio.c b/bfd/bfdio.c
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+/* Low-level I/O routines for BFDs.
+ Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ 2000, 2001, 2002 Free Software Foundation, Inc.
+ Written by Cygnus Support.
+
+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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#include "sysdep.h"
+
+#include "bfd.h"
+#include "libbfd.h"
+
+#include <limits.h>
+
+#ifndef S_IXUSR
+#define S_IXUSR 0100 /* Execute by owner. */
+#endif
+#ifndef S_IXGRP
+#define S_IXGRP 0010 /* Execute by group. */
+#endif
+#ifndef S_IXOTH
+#define S_IXOTH 0001 /* Execute by others. */
+#endif
+
+/* 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 size_t real_read PARAMS ((PTR where, size_t a, size_t b, FILE *file));
+static size_t
+real_read (where, a, b, file)
+ PTR where;
+ size_t a;
+ size_t b;
+ FILE *file;
+{
+ /* 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 (a == 0 || b == 0)
+ return 0;
+
+
+#if defined (__VAX) && defined (VMS)
+ /* Apparently fread on Vax VMS does not keep the record length
+ information. */
+ return read (fileno (file), where, a * b);
+#else
+ return fread (where, a, b, file);
+#endif
+}
+
+/* Return value is amount read. */
+
+bfd_size_type
+bfd_bread (ptr, size, abfd)
+ PTR ptr;
+ bfd_size_type size;
+ bfd *abfd;
+{
+ size_t nread;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ {
+ struct bfd_in_memory *bim;
+ bfd_size_type get;
+
+ bim = (struct bfd_in_memory *) abfd->iostream;
+ get = size;
+ if (abfd->where + get > bim->size)
+ {
+ if (bim->size < (bfd_size_type) abfd->where)
+ get = 0;
+ else
+ get = bim->size - abfd->where;
+ bfd_set_error (bfd_error_file_truncated);
+ }
+ memcpy (ptr, bim->buffer + abfd->where, (size_t) get);
+ abfd->where += get;
+ return get;
+ }
+
+ nread = real_read (ptr, 1, (size_t) size, bfd_cache_lookup (abfd));
+ if (nread != (size_t) -1)
+ abfd->where += nread;
+
+ /* 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.
+
+ A BFD backend may wish to override bfd_error_file_truncated to
+ provide something more useful (eg. no_symbols or wrong_format). */
+ if (nread != size)
+ {
+ if (ferror (bfd_cache_lookup (abfd)))
+ bfd_set_error (bfd_error_system_call);
+ else
+ bfd_set_error (bfd_error_file_truncated);
+ }
+
+ return nread;
+}
+
+bfd_size_type
+bfd_bwrite (ptr, size, abfd)
+ const PTR ptr;
+ bfd_size_type size;
+ bfd *abfd;
+{
+ size_t nwrote;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ {
+ struct bfd_in_memory *bim = (struct bfd_in_memory *) (abfd->iostream);
+ size = (size_t) size;
+ if (abfd->where + size > bim->size)
+ {
+ bfd_size_type newsize, oldsize;
+
+ oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
+ bim->size = abfd->where + size;
+ /* Round up to cut down on memory fragmentation */
+ newsize = (bim->size + 127) & ~(bfd_size_type) 127;
+ if (newsize > oldsize)
+ {
+ bim->buffer = (bfd_byte *) bfd_realloc (bim->buffer, newsize);
+ if (bim->buffer == 0)
+ {
+ bim->size = 0;
+ return 0;
+ }
+ }
+ }
+ memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
+ abfd->where += size;
+ return size;
+ }
+
+ nwrote = fwrite (ptr, 1, (size_t) size, bfd_cache_lookup (abfd));
+ if (nwrote != (size_t) -1)
+ abfd->where += nwrote;
+ if (nwrote != size)
+ {
+#ifdef ENOSPC
+ errno = ENOSPC;
+#endif
+ bfd_set_error (bfd_error_system_call);
+ }
+ return nwrote;
+}
+
+bfd_vma
+bfd_tell (abfd)
+ bfd *abfd;
+{
+ file_ptr ptr;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ return abfd->where;
+
+ ptr = ftell (bfd_cache_lookup (abfd));
+
+ if (abfd->my_archive)
+ ptr -= abfd->origin;
+ abfd->where = ptr;
+ return ptr;
+}
+
+int
+bfd_flush (abfd)
+ bfd *abfd;
+{
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ return 0;
+ return fflush (bfd_cache_lookup(abfd));
+}
+
+/* Returns 0 for success, negative value for failure (in which case
+ bfd_get_error can retrieve the error code). */
+int
+bfd_stat (abfd, statbuf)
+ bfd *abfd;
+ struct stat *statbuf;
+{
+ FILE *f;
+ int result;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+
+ f = bfd_cache_lookup (abfd);
+ if (f == NULL)
+ {
+ bfd_set_error (bfd_error_system_call);
+ return -1;
+ }
+ result = fstat (fileno (f), statbuf);
+ if (result < 0)
+ bfd_set_error (bfd_error_system_call);
+ return result;
+}
+
+/* Returns 0 for success, nonzero for failure (in which case bfd_get_error
+ can retrieve the error code). */
+
+int
+bfd_seek (abfd, position, direction)
+ bfd *abfd;
+ file_ptr position;
+ int direction;
+{
+ int result;
+ FILE *f;
+ long file_position;
+ /* For the time being, a BFD may not seek to it's end. The problem
+ is that we don't easily have a way to recognize the end of an
+ element in an archive. */
+
+ BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
+
+ if (direction == SEEK_CUR && position == 0)
+ return 0;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ {
+ struct bfd_in_memory *bim;
+
+ bim = (struct bfd_in_memory *) abfd->iostream;
+
+ if (direction == SEEK_SET)
+ abfd->where = position;
+ else
+ abfd->where += position;
+
+ if (abfd->where > bim->size)
+ {
+ if ((abfd->direction == write_direction) ||
+ (abfd->direction == both_direction))
+ {
+ bfd_size_type newsize, oldsize;
+ oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
+ bim->size = abfd->where;
+ /* Round up to cut down on memory fragmentation */
+ newsize = (bim->size + 127) & ~(bfd_size_type) 127;
+ if (newsize > oldsize)
+ {
+ bim->buffer = (bfd_byte *) bfd_realloc (bim->buffer, newsize);
+ if (bim->buffer == 0)
+ {
+ bim->size = 0;
+ return -1;
+ }
+ }
+ }
+ else
+ {
+ abfd->where = bim->size;
+ bfd_set_error (bfd_error_file_truncated);
+ return -1;
+ }
+ }
+ return 0;
+ }
+
+ if (abfd->format != bfd_archive && abfd->my_archive == 0)
+ {
+#if 0
+ /* Explanation for this code: I'm only about 95+% sure that the above
+ conditions are sufficient and that all i/o calls are properly
+ adjusting the `where' field. So this is sort of an `assert'
+ that the `where' field is correct. If we can go a while without
+ tripping the abort, we can probably safely disable this code,
+ so that the real optimizations happen. */
+ file_ptr where_am_i_now;
+ where_am_i_now = ftell (bfd_cache_lookup (abfd));
+ if (abfd->my_archive)
+ where_am_i_now -= abfd->origin;
+ if (where_am_i_now != abfd->where)
+ abort ();
+#endif
+ if (direction == SEEK_SET && (bfd_vma) position == abfd->where)
+ return 0;
+ }
+ else
+ {
+ /* We need something smarter to optimize access to archives.
+ Currently, anything inside an archive is read via the file
+ handle for the archive. Which means that a bfd_seek on one
+ component affects the `current position' in the archive, as
+ well as in any other component.
+
+ It might be sufficient to put a spike through the cache
+ abstraction, and look to the archive for the file position,
+ but I think we should try for something cleaner.
+
+ In the meantime, no optimization for archives. */
+ }
+
+ f = bfd_cache_lookup (abfd);
+ file_position = position;
+ if (direction == SEEK_SET && abfd->my_archive != NULL)
+ file_position += abfd->origin;
+
+ result = fseek (f, file_position, direction);
+ if (result != 0)
+ {
+ int hold_errno = errno;
+
+ /* Force redetermination of `where' field. */
+ bfd_tell (abfd);
+
+ /* An EINVAL error probably means that the file offset was
+ absurd. */
+ if (hold_errno == EINVAL)
+ bfd_set_error (bfd_error_file_truncated);
+ else
+ {
+ bfd_set_error (bfd_error_system_call);
+ errno = hold_errno;
+ }
+ }
+ else
+ {
+ /* Adjust `where' field. */
+ if (direction == SEEK_SET)
+ abfd->where = position;
+ else
+ abfd->where += position;
+ }
+ return result;
+}
+
+/*
+FUNCTION
+ bfd_get_mtime
+
+SYNOPSIS
+ long bfd_get_mtime(bfd *abfd);
+
+DESCRIPTION
+ Return the file modification time (as read from the file system, or
+ from the archive header for archive members).
+
+*/
+
+long
+bfd_get_mtime (abfd)
+ bfd *abfd;
+{
+ FILE *fp;
+ struct stat buf;
+
+ if (abfd->mtime_set)
+ return abfd->mtime;
+
+ fp = bfd_cache_lookup (abfd);
+ if (0 != fstat (fileno (fp), &buf))
+ return 0;
+
+ abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */
+ return buf.st_mtime;
+}
+
+/*
+FUNCTION
+ bfd_get_size
+
+SYNOPSIS
+ long bfd_get_size(bfd *abfd);
+
+DESCRIPTION
+ Return the file size (as read from file system) for the file
+ associated with BFD @var{abfd}.
+
+ The initial motivation for, and use of, this routine is not
+ so we can get the exact size of the object the BFD applies to, since
+ that might not be generally possible (archive members for example).
+ It would be ideal if someone could eventually modify
+ it so that such results were guaranteed.
+
+ Instead, we want to ask questions like "is this NNN byte sized
+ object I'm about to try read from file offset YYY reasonable?"
+ As as example of where we might do this, some object formats
+ use string tables for which the first <<sizeof (long)>> bytes of the
+ table contain the size of the table itself, including the size bytes.
+ If an application tries to read what it thinks is one of these
+ string tables, without some way to validate the size, and for
+ some reason the size is wrong (byte swapping error, wrong location
+ for the string table, etc.), the only clue is likely to be a read
+ error when it tries to read the table, or a "virtual memory
+ exhausted" error when it tries to allocate 15 bazillon bytes
+ of space for the 15 bazillon byte table it is about to read.
+ This function at least allows us to answer the quesion, "is the
+ size reasonable?".
+*/
+
+long
+bfd_get_size (abfd)
+ bfd *abfd;
+{
+ FILE *fp;
+ struct stat buf;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ return ((struct bfd_in_memory *) abfd->iostream)->size;
+
+ fp = bfd_cache_lookup (abfd);
+ if (0 != fstat (fileno (fp), & buf))
+ return 0;
+
+ return buf.st_size;
+}