git.cworth.org Git - gzip/blob - m4/fcntl_h.m4

   1 # Configure fcntl.h.
   2 dnl Copyright (C) 2006 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 dnl Written by Paul Eggert.
   8
   9 AC_DEFUN([gl_FCNTL_H],
  10 [
  11   AC_CACHE_CHECK([for working fcntl.h], gl_cv_header_working_fcntl_h,
  12     [AC_RUN_IFELSE(
  13        [AC_LANG_PROGRAM(
  14           [[#include <sys/types.h>
  15            #include <sys/stat.h>
  16            #include <unistd.h>
  17            #include <fcntl.h>
  18            #ifndef O_NOATIME
  19             #define O_NOATIME 0
  20            #endif
  21            #ifndef O_NOFOLLOW
  22             #define O_NOFOLLOW 0
  23            #endif
  24            static int const constants[] =
  25             {
  26               O_CREAT, O_EXCL, O_NOCTTY, O_TRUNC, O_APPEND,
  27               O_NONBLOCK, O_SYNC, O_ACCMODE, O_RDONLY, O_RDWR, O_WRONLY
  28             };
  29           ]],
  30           [[
  31             int status = !constants;
  32             {
  33               static char const sym[] = "conftest.sym";
  34               if (symlink (".", sym) != 0
  35                   || close (open (sym, O_RDONLY | O_NOFOLLOW)) == 0)
  36                 status |= 32;
  37             }
  38             {
  39               static char const file[] = "confdefs.h";
  40               int fd = open (file, O_RDONLY | O_NOATIME);
  41               char c;
  42               struct stat st0, st1;
  43               if (fd < 0
  44                   || fstat (fd, &st0) != 0
  45                   || sleep (1) != 0
  46                   || read (fd, &c, 1) != 1
  47                   || close (fd) != 0
  48                   || stat (file, &st1) != 0
  49                   || st0.st_atime != st1.st_atime)
  50                 status |= 64;
  51             }
  52             return status;]])],
  53        [gl_cv_header_working_fcntl_h=yes],
  54        [case $? in #(
  55         32) gl_cv_header_working_fcntl_h='no (bad O_NOFOLLOW)';; #(
  56         64) gl_cv_header_working_fcntl_h='no (bad O_NOATIME)';; #(
  57         96) gl_cv_header_working_fcntl_h='no (bad O_NOATIME, O_NOFOLLOW)';; #(
  58          *) gl_cv_header_working_fcntl_h='no';;
  59         esac],
  60        [gl_cv_header_working_fcntl_h=cross-compiling])])
  61
  62   case $gl_cv_header_working_fcntl_h in #(
  63   *O_NOATIME* | no | cross-compiling) ac_val=0;; #(
  64   *) ac_val=1;;
  65   esac
  66   AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$ac_val],
  67     [Define to 1 if O_NOATIME works.])
  68
  69   case $gl_cv_header_working_fcntl_h in #(
  70   *O_NOFOLLOW* | no | cross-compiling) ac_val=0;; #(
  71   *) ac_val=1;;
  72   esac
  73   AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$ac_val],
  74     [Define to 1 if O_NOFOLLOW works.])
  75
  76   gl_ABSOLUTE_HEADER([fcntl.h])
  77   ABSOLUTE_FCNTL_H=\"$gl_cv_absolute_fcntl_h\"
  78   AC_SUBST([ABSOLUTE_FCNTL_H])
  79   FCNTL_H='fcntl.h'
  80   AC_SUBST([FCNTL_H])
  81 ])