Merge from coreutils.

[gnulib.git] / m4 / stdbool.m4

diff --git a/m4/stdbool.m4 b/m4/stdbool.m4
index def6e14..b25b7d2 100644 (file)
--- a/m4/stdbool.m4
+++ b/m4/stdbool.m4
@@ -1,6 +1,6 @@
 # Check for stdbool.h that conforms to C99.
 
-# Copyright (C) 2002 Free Software Foundation, Inc.
+# Copyright (C) 2002-2004 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -17,7 +17,30 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 # 02111-1307, USA.
 
-# This file is only needed in autoconf <= 2.54.  Newer versions of autoconf
+# Prepare for substituting <stdbool.h> if it is not supported.
+
+AC_DEFUN([AM_STDBOOL_H],
+[
+  AC_REQUIRE([AC_HEADER_STDBOOL])
+
+  # Define two additional variables used in the Makefile substitution.
+
+  if test "$ac_cv_header_stdbool_h" = yes; then
+    STDBOOL_H=''
+  else
+    STDBOOL_H='stdbool.h'
+  fi
+  AC_SUBST([STDBOOL_H])
+
+  if test "$ac_cv_type__Bool" = yes; then
+    HAVE__BOOL=1
+  else
+    HAVE__BOOL=0
+  fi
+  AC_SUBST([HAVE__BOOL])
+])
+
+# This macro is only needed in autoconf <= 2.59.  Newer versions of autoconf
 # have this macro built-in.
 
 AC_DEFUN([AC_HEADER_STDBOOL],
@@ -36,7 +59,7 @@ AC_DEFUN([AC_HEADER_STDBOOL],
           "error: false is not 0"
          #endif
          #ifndef true
-          "error: false is not defined"
+          "error: true is not defined"
          #endif
          #if true != 1
           "error: true is not 1"
@@ -56,8 +79,14 @@ AC_DEFUN([AC_HEADER_STDBOOL],
          char g[true];
          char h[sizeof (_Bool)];
          char i[sizeof s.t];
+         enum { j = false, k = true, l = false * true, m = true * 256 };
+         _Bool n[m];
+         char o[sizeof n == m * sizeof n[0] ? 1 : -1];
+       ],
+       [
+         return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !j + !k + !l
+                 + !m + !n + !o);
        ],
-       [ return !a + !b + !c + !d + !e + !f + !g + !h + !i; ],
        [ac_cv_header_stdbool_h=yes],
        [ac_cv_header_stdbool_h=no])])
    AC_CHECK_TYPES([_Bool])