lib/fstat.c

   1 /* fstat() replacement.
   2    Copyright (C) 2011-2017 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* If the user's config.h happens to include <sys/stat.h>, let it include only
  18    the system's <sys/stat.h> here, so that orig_fstat doesn't recurse to
  19    rpl_fstat.  */
  20 #define __need_system_sys_stat_h
  21 #include <config.h>
  22
  23 /* Get the original definition of fstat.  It might be defined as a macro.  */
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #undef __need_system_sys_stat_h
  27
  28 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  29 # define WINDOWS_NATIVE
  30 #endif
  31
  32 #if !defined WINDOWS_NATIVE
  33
  34 static int
  35 orig_fstat (int fd, struct stat *buf)
  36 {
  37   return fstat (fd, buf);
  38 }
  39
  40 #endif
  41
  42 /* Specification.  */
  43 /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
  44    eliminates this include because of the preliminary #include <sys/stat.h>
  45    above.  */
  46 #include "sys/stat.h"
  47
  48 #include <errno.h>
  49 #include <unistd.h>
  50 #ifdef WINDOWS_NATIVE
  51 # define WIN32_LEAN_AND_MEAN
  52 # include <windows.h>
  53 # if GNULIB_MSVC_NOTHROW
  54 #  include "msvc-nothrow.h"
  55 # else
  56 #  include <io.h>
  57 # endif
  58 # include "stat-w32.h"
  59 #endif
  60
  61 int
  62 rpl_fstat (int fd, struct stat *buf)
  63 {
  64 #if REPLACE_FCHDIR && REPLACE_OPEN_DIRECTORY
  65   /* Handle the case when rpl_open() used a dummy file descriptor to work
  66      around an open() that can't normally visit directories.  */
  67   const char *name = _gl_directory_name (fd);
  68   if (name != NULL)
  69     return stat (name, buf);
  70 #endif
  71
  72 #ifdef WINDOWS_NATIVE
  73   /* Fill the fields ourselves, because the original fstat function returns
  74      values for st_atime, st_mtime, st_ctime that depend on the current time
  75      zone.  See
  76      <https://lists.gnu.org/archive/html/bug-gnulib/2017-04/msg00134.html>  */
  77   HANDLE h = (HANDLE) _get_osfhandle (fd);
  78
  79   if (h == INVALID_HANDLE_VALUE)
  80     {
  81       errno = EBADF;
  82       return -1;
  83     }
  84   return _gl_fstat_by_handle (h, NULL, buf);
  85 #else
  86   return orig_fstat (fd, buf);
  87 #endif
  88 }