# Check for stdbool.h that conforms to C99.

dnl Copyright (C) 2002-2006, 2009-2015 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.

#serial 5

# Prepare for substituting <stdbool.h> if it is not supported.

AC_DEFUN([AM_STDBOOL_H],

[

  AC_REQUIRE([AC_CHECK_HEADER_STDBOOL])

  # Define two additional variables used in the Makefile substitution.

  if test "$ac_cv_header_stdbool_h" = yes; then

    STDBOOL_H=''

  else

    STDBOOL_H='stdbool.h'

  fi

  AC_SUBST([STDBOOL_H])

  AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$STDBOOL_H"])

  if test "$ac_cv_type__Bool" = yes; then

    HAVE__BOOL=1

  else

    HAVE__BOOL=0

  fi

  AC_SUBST([HAVE__BOOL])

])

# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.

AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])

# This version of the macro is needed in autoconf <= 2.68.

AC_DEFUN([AC_CHECK_HEADER_STDBOOL],

  [AC_CACHE_CHECK([for stdbool.h that conforms to C99],

     [ac_cv_header_stdbool_h],

     [AC_COMPILE_IFELSE(

        [AC_LANG_PROGRAM(

           [[

             #include <stdbool.h>

             #ifndef bool

              "error: bool is not defined"

             #endif

             #ifndef false

              "error: false is not defined"

             #endif

             #if false

              "error: false is not 0"

             #endif

             #ifndef true

              "error: true is not defined"

             #endif

             #if true != 1

              "error: true is not 1"

             #endif

             #ifndef __bool_true_false_are_defined

              "error: __bool_true_false_are_defined is not defined"

             #endif

             struct s { _Bool s: 1; _Bool t; } s;

             char a[true == 1 ? 1 : -1];

             char b[false == 0 ? 1 : -1];

             char c[__bool_true_false_are_defined == 1 ? 1 : -1];

             char d[(bool) 0.5 == true ? 1 : -1];

             /* See body of main program for 'e'.  */

             char f[(_Bool) 0.0 == false ? 1 : -1];

             char g[true];

             char h[sizeof (_Bool)];

             char i[sizeof s.t];

             enum { j = false, k = true, l = false * true, m = true * 256 };

             /* The following fails for

                HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */

             _Bool n[m];

             char o[sizeof n == m * sizeof n[0] ? 1 : -1];

             char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];

             /* Catch a bug in an HP-UX C compiler.  See

                http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html

                http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html

              */

             _Bool q = true;

             _Bool *pq = &q;

           ]],

           [[

             bool e = &s;

             *pq |= q;

             *pq |= ! q;

             /* Refer to every declared value, to avoid compiler optimizations.  */

             return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l

                     + !m + !n + !o + !p + !q + !pq);

           ]])],

        [ac_cv_header_stdbool_h=yes],

        [ac_cv_header_stdbool_h=no])])

   AC_CHECK_TYPES([_Bool])

])