glibc/libio/iofopen.c

110 lines
3.4 KiB
C

/* Copyright (C) 1993-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
that does not cause the resulting executable to be covered by
the GNU Lesser General Public License. This exception does not
however invalidate any other reasons why the executable file
might be covered by the GNU Lesser General Public License.
This exception applies to code released by its copyright holders
in files containing the exception. */
#include "libioP.h"
#include <fcntl.h>
#include <stdlib.h>
#include <stddef.h>
#ifdef _LIBC
# include <shlib-compat.h>
#else
# define _IO_new_fopen fopen
#endif
_IO_FILE *
__fopen_maybe_mmap (_IO_FILE *fp)
{
#ifdef _G_HAVE_MMAP
if ((fp->_flags2 & _IO_FLAGS2_MMAP) && (fp->_flags & _IO_NO_WRITES))
{
/* Since this is read-only, we might be able to mmap the contents
directly. We delay the decision until the first read attempt by
giving it a jump table containing functions that choose mmap or
vanilla file operations and reset the jump table accordingly. */
if (fp->_mode <= 0)
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_maybe_mmap;
else
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_maybe_mmap;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_maybe_mmap;
}
#endif
return fp;
}
_IO_FILE *
__fopen_internal (const char *filename, const char *mode, int is32)
{
struct locked_FILE
{
struct _IO_FILE_plus fp;
#ifdef _IO_MTSAFE_IO
_IO_lock_t lock;
#endif
struct _IO_wide_data wd;
} *new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
if (new_f == NULL)
return NULL;
#ifdef _IO_MTSAFE_IO
new_f->fp.file._lock = &new_f->lock;
#endif
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
_IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd, &_IO_wfile_jumps);
#else
_IO_no_init (&new_f->fp.file, 1, 0, NULL, NULL);
#endif
_IO_JUMPS (&new_f->fp) = &_IO_file_jumps;
_IO_file_init (&new_f->fp);
#if !_IO_UNIFIED_JUMPTABLES
new_f->fp.vtable = NULL;
#endif
if (_IO_file_fopen ((_IO_FILE *) new_f, filename, mode, is32) != NULL)
return __fopen_maybe_mmap (&new_f->fp.file);
_IO_un_link (&new_f->fp);
free (new_f);
return NULL;
}
_IO_FILE *
_IO_new_fopen (const char *filename, const char *mode)
{
return __fopen_internal (filename, mode, 1);
}
#ifdef _LIBC
strong_alias (_IO_new_fopen, __new_fopen)
versioned_symbol (libc, _IO_new_fopen, _IO_fopen, GLIBC_2_1);
versioned_symbol (libc, __new_fopen, fopen, GLIBC_2_1);
# if !defined O_LARGEFILE || O_LARGEFILE == 0
weak_alias (_IO_new_fopen, _IO_fopen64)
weak_alias (_IO_new_fopen, fopen64)
# endif
#endif