autoconf: detect the broken bool in OpenWatcom 1.8

OpenWatcom 1.8 has a C99 mode, which implements _Bool and
<stdbool.h>.  Unfortunately the implementation is broken, and doesn't
let _Bool be implicitly converted to integer (as required by the C99
spec).  Detect this case in autoconf.

1 files changed, 24 insertions, 0 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index e25d13d..5159c11 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -13,3 +13,27 @@ AC_DEFUN(PA_ADD_CFLAGS,
  AC_MSG_RESULT([no])
  CFLAGS="$pa_add_cflags__old_cflags")])
 
+dnl --------------------------------------------------------------------------
+dnl PA_WORKING_STDBOOL
+dnl
+dnl See if we have a working <stdbool.h> and bool support; in particular,
+dnl OpenWatcom 1.8 has a broken _Bool type that we don't want to use.
+dnl --------------------------------------------------------------------------
+AC_DEFUN(PA_WORKING_BOOL,
+[AC_MSG_CHECKING([if $CC has a working bool type])
+ AC_COMPILE_IFELSE(
+ [
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
+int foo(bool x, int y)
+{
+	return x+y;
+}
+ ],
+ [AC_MSG_RESULT([yes])
+  AC_DEFINE(HAVE_WORKING_BOOL, 1,
+    [Define to 1 if your compiler has a correct implementation of bool])],
+ [AC_MSG_RESULT([no])])
+])
+