xen/compat: use BUILD_BUG_ON in CHECK_SIZE macros

BUILD_BUG_ON is the preferred way to induce a build error
upon statically determined incorrect conditions.

This also fixes a MISRA C:2012 Rule 10.1 violation in the
previous formulation.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/include/xen/compat.h b/xen/include/xen/compat.h
index f2ce5bb3580ae08dacc949a8d8c6288997bb8363..41a5d61eef98b29a44580b2888e9de365f5f8c34 100644 (file)
--- a/xen/include/xen/compat.h
+++ b/xen/include/xen/compat.h
@@ -151,12 +151,18 @@ CHECK_NAME_(k, n, T)(k xen_ ## n *x, \
     return x == c; \
 }
 
-#define CHECK_SIZE(name) \
-    typedef int CHECK_NAME(name, S)[1 - (sizeof(xen_ ## name ## _t) != \
-                                         sizeof(compat_ ## name ## _t)) * 2]
+#define CHECK_SIZE(name)                                  \
+static inline void __maybe_unused CHECK_SIZE_##name(void) \
+{                                                         \
+    BUILD_BUG_ON(sizeof(xen_ ## name ## _t) !=            \
+                 sizeof(compat_ ## name ## _t));          \
+}
 #define CHECK_SIZE_(k, n) \
-    typedef int CHECK_NAME_(k, n, S)[1 - (sizeof(k xen_ ## n) != \
-                                          sizeof(k compat_ ## n)) * 2]
+static inline void __maybe_unused CHECK_SIZE_##k_##n(void) \
+{                                                          \
+    BUILD_BUG_ON(sizeof(k xen_ ## n) !=                    \
+                 sizeof(k compat_ ## n));                  \
+}
 
 #define CHECK_FIELD_COMMON(name, t, f) \
 static inline int __maybe_unused name(xen_ ## t ## _t *x, compat_ ## t ## _t *c) \