# btowc.m4 serial 11

dnl Copyright (C) 2008-2018 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_BTOWC],

[

  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])

  dnl Check whether <wchar.h> is usable at all, first. Otherwise the test

  dnl program below may lead to an endless loop. See

  dnl <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>.

  AC_REQUIRE([gl_WCHAR_H_INLINE_OK])

  AC_CHECK_FUNCS_ONCE([btowc])

  if test $ac_cv_func_btowc = no; then

    HAVE_BTOWC=0

  else

    AC_REQUIRE([AC_PROG_CC])

    AC_REQUIRE([gt_LOCALE_FR])

    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.

    AC_CACHE_CHECK([whether btowc(0) is correct],

      [gl_cv_func_btowc_nul],

      [

        AC_RUN_IFELSE(

          [AC_LANG_SOURCE([[

#include <string.h>

/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before

   <wchar.h>.

   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be

   included before <wchar.h>.  */

#include <stddef.h>

#include <stdio.h>

#include <time.h>

#include <wchar.h>

int main ()

{

  if (btowc ('\0') != 0)

    return 1;

  return 0;

}]])],

          [gl_cv_func_btowc_nul=yes],

          [gl_cv_func_btowc_nul=no],

          [

changequote(,)dnl

           case "$host_os" in

                      # Guess no on Cygwin.

             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;

                      # Guess yes on native Windows.

             mingw*)  gl_cv_func_btowc_nul="guessing yes" ;;

                      # Guess yes otherwise.

             *)       gl_cv_func_btowc_nul="guessing yes" ;;

           esac

changequote([,])dnl

          ])

      ])

    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.

    AC_CACHE_CHECK([whether btowc(EOF) is correct],

      [gl_cv_func_btowc_eof],

      [

        dnl Initial guess, used when cross-compiling or when no suitable locale

        dnl is present.

changequote(,)dnl

        case "$host_os" in

                  # Guess no on IRIX.

          irix*)  gl_cv_func_btowc_eof="guessing no" ;;

                  # Guess yes on native Windows.

          mingw*) gl_cv_func_btowc_eof="guessing yes" ;;

                  # Guess yes otherwise.

          *)      gl_cv_func_btowc_eof="guessing yes" ;;

        esac

changequote([,])dnl

        if test $LOCALE_FR != none; then

          AC_RUN_IFELSE(

            [AC_LANG_SOURCE([[

#include <locale.h>

#include <string.h>

/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before

   <wchar.h>.

   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be

   included before <wchar.h>.  */

#include <stddef.h>

#include <stdio.h>

#include <time.h>

#include <wchar.h>

int main ()

{

  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)

    {

      if (btowc (EOF) != WEOF)

        return 1;

    }

  return 0;

}]])],

            [gl_cv_func_btowc_eof=yes],

            [gl_cv_func_btowc_eof=no],

            [:])

        fi

      ])

    case "$gl_cv_func_btowc_nul" in

      *yes) ;;

      *) REPLACE_BTOWC=1 ;;

    esac

    case "$gl_cv_func_btowc_eof" in

      *yes) ;;

      *) REPLACE_BTOWC=1 ;;

    esac

  fi

])

# Prerequisites of lib/btowc.c.

AC_DEFUN([gl_PREREQ_BTOWC], [

  :

])