# http://llvm.org/bugs/show_bug.cgi?id=19007

--- xpcom/base/nscore.h~
+++ xpcom/base/nscore.h
@@ -110,7 +110,7 @@
  *           NS_HIDDEN_(int) NS_FASTCALL func2(char *foo);
  */
 
-#if defined(__i386__) && defined(__GNUC__) && !defined(XP_OS2)
+#if defined(__i386__) && defined(__GNUC__) && !defined(XP_OS2) && !(defined(__clang__) && __clang_major__ == 3 && __clang_minor__ == 4 && __clang_patchlevel__ == 0)
 #define NS_FASTCALL __attribute__ ((regparm (3), stdcall))
 #define NS_CONSTRUCTOR_FASTCALL __attribute__ ((regparm (3), stdcall))
 #elif defined(XP_WIN) && !defined(_WIN64)