libio/iofopen.c

   1 /* Copyright (C) 1993,1997,1998,1999,2000,2002,2003
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 #include "libioP.h"
  30 #ifdef __STDC__
  31 #include <stdlib.h>
  32 #include <stddef.h>
  33 #endif
  34 #ifdef _LIBC
  35 # include <shlib-compat.h>
  36 #else
  37 # define _IO_new_fopen fopen
  38 #endif
  39
  40 _IO_FILE *
  41 __fopen_maybe_mmap (fp)
  42      _IO_FILE *fp;
  43 {
  44 #ifdef _G_HAVE_MMAP
  45   if ((fp->_flags2 & _IO_FLAGS2_MMAP) && (fp->_flags & _IO_NO_WRITES))
  46     {
  47       /* Since this is read-only, we might be able to mmap the contents
  48          directly.  We delay the decision until the first read attempt by
  49          giving it a jump table containing functions that choose mmap or
  50          vanilla file operations and reset the jump table accordingly.  */
  51
  52       if (fp->_mode <= 0)
  53         _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_maybe_mmap;
  54       else
  55         _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_maybe_mmap;
  56       fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_maybe_mmap;
  57     }
  58 #endif
  59   return fp;
  60 }
  61
  62
  63 _IO_FILE *
  64 __fopen_internal (filename, mode, is32)
  65      const char *filename;
  66      const char *mode;
  67      int is32;
  68 {
  69   struct locked_FILE
  70   {
  71     struct _IO_FILE_plus fp;
  72 #ifdef _IO_MTSAFE_IO
  73     _IO_lock_t lock;
  74 #endif
  75     struct _IO_wide_data wd;
  76   } *new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
  77
  78   if (new_f == NULL)
  79     return NULL;
  80 #ifdef _IO_MTSAFE_IO
  81   new_f->fp.file._lock = &new_f->lock;
  82 #endif
  83 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
  84   _IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd, &_IO_wfile_jumps);
  85 #else
  86   _IO_no_init (&new_f->fp.file, 1, 0, NULL, NULL);
  87 #endif
  88   _IO_JUMPS (&new_f->fp) = &_IO_file_jumps;
  89   INTUSE(_IO_file_init) (&new_f->fp);
  90 #if  !_IO_UNIFIED_JUMPTABLES
  91   new_f->fp.vtable = NULL;
  92 #endif
  93   if (INTUSE(_IO_file_fopen) ((_IO_FILE *) new_f, filename, mode, is32)
  94       != NULL)
  95     return __fopen_maybe_mmap (&new_f->fp.file);
  96
  97   INTUSE(_IO_un_link) (&new_f->fp);
  98   free (new_f);
  99   return NULL;
 100 }
 101
 102 _IO_FILE *
 103 _IO_new_fopen (filename, mode)
 104      const char *filename;
 105      const char *mode;
 106 {
 107   return __fopen_internal (filename, mode, 1);
 108 }
 109
 110 #ifdef _LIBC
 111 strong_alias (_IO_new_fopen, __new_fopen)
 112 versioned_symbol (libc, _IO_new_fopen, _IO_fopen, GLIBC_2_1);
 113 versioned_symbol (libc, __new_fopen, fopen, GLIBC_2_1);
 114 #endif