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1.1 ! misho 1: # fcntl-o.m4 serial 1 ! 2: dnl Copyright (C) 2006, 2009-2010 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: # Test whether the flags O_NOATIME and O_NOFOLLOW actually work. ! 10: # Define HAVE_WORKING_O_NOATIME to 1 if O_NOATIME works, or to 0 otherwise. ! 11: # Define HAVE_WORKING_O_NOFOLLOW to 1 if O_NOFOLLOW works, or to 0 otherwise. ! 12: AC_DEFUN([gl_FCNTL_O_FLAGS], ! 13: [ ! 14: dnl Persuade glibc <fcntl.h> to define O_NOATIME and O_NOFOLLOW. ! 15: AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) ! 16: AC_CACHE_CHECK([for working fcntl.h], [gl_cv_header_working_fcntl_h], ! 17: [AC_RUN_IFELSE( ! 18: [AC_LANG_PROGRAM( ! 19: [[#include <sys/types.h> ! 20: #include <sys/stat.h> ! 21: #include <unistd.h> ! 22: #include <fcntl.h> ! 23: #ifndef O_NOATIME ! 24: #define O_NOATIME 0 ! 25: #endif ! 26: #ifndef O_NOFOLLOW ! 27: #define O_NOFOLLOW 0 ! 28: #endif ! 29: static int const constants[] = ! 30: { ! 31: O_CREAT, O_EXCL, O_NOCTTY, O_TRUNC, O_APPEND, ! 32: O_NONBLOCK, O_SYNC, O_ACCMODE, O_RDONLY, O_RDWR, O_WRONLY ! 33: }; ! 34: ]], ! 35: [[ ! 36: int status = !constants; ! 37: { ! 38: static char const sym[] = "conftest.sym"; ! 39: if (symlink (".", sym) != 0 ! 40: || close (open (sym, O_RDONLY | O_NOFOLLOW)) == 0) ! 41: status |= 32; ! 42: unlink (sym); ! 43: } ! 44: { ! 45: static char const file[] = "confdefs.h"; ! 46: int fd = open (file, O_RDONLY | O_NOATIME); ! 47: char c; ! 48: struct stat st0, st1; ! 49: if (fd < 0 ! 50: || fstat (fd, &st0) != 0 ! 51: || sleep (1) != 0 ! 52: || read (fd, &c, 1) != 1 ! 53: || close (fd) != 0 ! 54: || stat (file, &st1) != 0 ! 55: || st0.st_atime != st1.st_atime) ! 56: status |= 64; ! 57: } ! 58: return status;]])], ! 59: [gl_cv_header_working_fcntl_h=yes], ! 60: [case $? in #( ! 61: 32) gl_cv_header_working_fcntl_h='no (bad O_NOFOLLOW)';; #( ! 62: 64) gl_cv_header_working_fcntl_h='no (bad O_NOATIME)';; #( ! 63: 96) gl_cv_header_working_fcntl_h='no (bad O_NOATIME, O_NOFOLLOW)';; #( ! 64: *) gl_cv_header_working_fcntl_h='no';; ! 65: esac], ! 66: [gl_cv_header_working_fcntl_h=cross-compiling])]) ! 67: ! 68: case $gl_cv_header_working_fcntl_h in #( ! 69: *O_NOATIME* | no | cross-compiling) ac_val=0;; #( ! 70: *) ac_val=1;; ! 71: esac ! 72: AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$ac_val], ! 73: [Define to 1 if O_NOATIME works.]) ! 74: ! 75: case $gl_cv_header_working_fcntl_h in #( ! 76: *O_NOFOLLOW* | no | cross-compiling) ac_val=0;; #( ! 77: *) ac_val=1;; ! 78: esac ! 79: AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$ac_val], ! 80: [Define to 1 if O_NOFOLLOW works.]) ! 81: ])