diff --git a/tools/llvmc/plugins/Clang/Clang.td b/tools/llvmc/plugins/Clang/Clang.td
index 0f5d8cd9180..f6195bead5d 100644
--- a/tools/llvmc/plugins/Clang/Clang.td
+++ b/tools/llvmc/plugins/Clang/Clang.td
@@ -5,53 +5,33 @@
 
 include "llvm/CompilerDriver/Common.td"
 
-
 def Options : OptionList<[
 (switch_option "E",
     (help "Stop after the preprocessing stage, do not run the compiler"))
 ]>;
 
-class clang_base<string language, dag cmdline> : Tool<
+class clang_based<string language, string cmd> : Tool<
 [(in_language language),
  (out_language "llvm-bitcode"),
  (output_suffix "bc"),
- (cmd_line cmdline),
+ (cmd_line (case
+           (switch_on "E"),
+           (case
+                (not_empty "o"),
+                !strconcat(cmd, " -E $INFILE -o $OUTFILE"),
+                (default),
+                !strconcat(cmd, " -E $INFILE")),
+          (default),
+          !strconcat(cmd, " -emit-llvm-bc $INFILE -o $OUTFILE"))),
  (switch_option "E", (stop_compilation), (output_suffix "i")),
  (sink)
 ]>;
 
-def clang_c : clang_base<"c",
-(case
-(switch_on "E"),
-    (case
-    (not_empty "o"),
-        "clang -E -x c $INFILE -o $OUTFILE",
-    (default),
-        "clang -E -x c $INFILE"),
-(default),
-    "clang -emit-llvm-bc -x c $INFILE -o $OUTFILE")>;
-
-def clang_cpp : clang_base<"c++",
-(case
-(switch_on "E"),
-    (case
-    (not_empty "o"),
-        "clang -E -x c++ $INFILE -o $OUTFILE",
-    (default),
-        "clang -E -x c++ $INFILE"),
-(default),
-    "clang -emit-llvm-bc -x c++ $INFILE -o $OUTFILE")>;
-
-def clang_objective_c : clang_base<"objective-c",
-(case
-(switch_on "E"),
-    (case
-    (not_empty "o"),
-        "clang -E -x objective-c $INFILE -o $OUTFILE",
-    (default),
-        "clang -E -x objective-c $INFILE"),
-(default),
-    "clang -emit-llvm-bc -x objective-c $INFILE -o $OUTFILE")>;
+def clang_c : clang_based<"c", "clang -x c">;
+def clang_cpp : clang_based<"c++", "clang -x c++">;
+def clang_objective_c : clang_based<"objective-c", "clang -x objective-c">;
+def clang_objective_cpp : clang_based<"objective-c++",
+    "clang -x objective-c++">;
 
 // Default linker
 def llvm_ld : Tool<