Rename to USE_OLD_JIT and USE_MCJIT.
diff --git a/Config.h b/Config.h
index 410d011..17554a3 100644
--- a/Config.h
+++ b/Config.h
@@ -4,8 +4,12 @@
//---------------------------------------------------------------------------
// Configuration for JIT & MC Assembler
//---------------------------------------------------------------------------
-#define CLASSIC_JIT 1
-#define MC_ASSEMBLER 0
+#define USE_OLD_JIT 1
+#define USE_MCJIT 0
+
+#if !USE_OLD_JIT && !USE_MCJIT
+#error "You should choose at least one code generation method."
+#endif
//---------------------------------------------------------------------------
// Configuration for libbcc