# open.m4 serial 15

dnl Copyright (C) 2007-2018 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_OPEN],

[

  AC_REQUIRE([AC_CANONICAL_HOST])

  AC_REQUIRE([gl_PREPROC_O_CLOEXEC])

  case "$host_os" in

    mingw* | pw*)

      REPLACE_OPEN=1

      ;;

    *)

      dnl open("foo/") should not create a file when the file name has a

      dnl trailing slash.  FreeBSD only has the problem on symlinks.

      AC_CHECK_FUNCS_ONCE([lstat])

      if test "$gl_cv_macro_O_CLOEXEC" != yes; then

        REPLACE_OPEN=1

      fi

      AC_CACHE_CHECK([whether open recognizes a trailing slash],

        [gl_cv_func_open_slash],

        [# Assume that if we have lstat, we can also check symlinks.

          if test $ac_cv_func_lstat = yes; then

            touch conftest.tmp

            ln -s conftest.tmp conftest.lnk

          fi

          AC_RUN_IFELSE(

            [AC_LANG_SOURCE([[

#include <fcntl.h>

#if HAVE_UNISTD_H

# include <unistd.h>

#endif

int main ()

{

  int result = 0;

#if HAVE_LSTAT

  if (open ("conftest.lnk/", O_RDONLY) != -1)

    result |= 1;

#endif

  if (open ("conftest.sl/", O_CREAT, 0600) >= 0)

    result |= 2;

  return result;

}]])],

            [gl_cv_func_open_slash=yes],

            [gl_cv_func_open_slash=no],

            [

changequote(,)dnl

             case "$host_os" in

               freebsd* | aix* | hpux* | solaris2.[0-9] | solaris2.[0-9].*)

                 gl_cv_func_open_slash="guessing no" ;;

               *)

                 gl_cv_func_open_slash="guessing yes" ;;

             esac

changequote([,])dnl

            ])

          rm -f conftest.sl conftest.tmp conftest.lnk

        ])

      case "$gl_cv_func_open_slash" in

        *no)

          AC_DEFINE([OPEN_TRAILING_SLASH_BUG], [1],

            [Define to 1 if open() fails to recognize a trailing slash.])

          REPLACE_OPEN=1

          ;;

      esac

      ;;

  esac

  dnl Replace open() for supporting the gnulib-defined fchdir() function,

  dnl to keep fchdir's bookkeeping up-to-date.

  m4_ifdef([gl_FUNC_FCHDIR], [

    if test $REPLACE_OPEN = 0; then

      gl_TEST_FCHDIR

      if test $HAVE_FCHDIR = 0; then

        REPLACE_OPEN=1

      fi

    fi

  ])

  dnl Replace open() for supporting the gnulib-defined O_NONBLOCK flag.

  m4_ifdef([gl_NONBLOCKING_IO], [

    if test $REPLACE_OPEN = 0; then

      gl_NONBLOCKING_IO

      if test $gl_cv_have_open_O_NONBLOCK != yes; then

        REPLACE_OPEN=1

      fi

    fi

  ])

])

# Prerequisites of lib/open.c.

AC_DEFUN([gl_PREREQ_OPEN],

[

  AC_REQUIRE([gl_PROMOTED_TYPE_MODE_T])

  :

])