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libiconv v1.14

    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: ])