linux/bits.h: fix compilation error with GENMASK

[linux-2.6-microblaze.git] / tools / include / linux / const.h

diff --git a/tools/include/linux/const.h b/tools/include/linux/const.h
index 81b8aae..435ddd7 100644 (file)
--- a/tools/include/linux/const.h
+++ b/tools/include/linux/const.h
@@ -3,4 +3,12 @@
 
 #include <vdso/const.h>
 
+/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
+ */
+#define __is_constexpr(x) \
+       (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
+
 #endif /* _LINUX_CONST_H */