@@ -144,11 +144,12 @@
 
 	return alignment;
 }
 
 static size_t
-#if defined(__clang__) && __clang_major__ == 3 && __clang_minor__ <= 7
+#if defined(__clang__) && __has_attribute(__optnone__) && \
+    __clang_major__ == 3 && __clang_minor__ <= 7
 /* Work around an ICE in Clang 3.7.0 on Windows/x86 */
 __attribute__((__optnone__))
 #endif
 alignmentOfEncoding(const char **type, size_t *length, bool inStruct)
 {
@@ -438,11 +439,12 @@
 
 	return size;
 }
 
 static size_t
-#if defined(__clang__) && __clang_major__ == 3 && __clang_minor__ <= 7
+#if defined(__clang__) && __has_attribute(__optnone__) && \
+    __clang_major__ == 3 && __clang_minor__ <= 7
 /* Work around an ICE in Clang 3.7.0 on Windows/x86 */
 __attribute__((__optnone__))
 #endif
 sizeOfEncoding(const char **type, size_t *length)
 {