libio/iofopen.c

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