diff --git a/lib/Support/GraphWriter.cpp b/lib/Support/GraphWriter.cpp
index aca46d8..32126ec 100644
--- a/lib/Support/GraphWriter.cpp
+++ b/lib/Support/GraphWriter.cpp
@@ -54,11 +54,9 @@
 }
 
 // Execute the graph viewer. Return true if successful.
-static bool ExecGraphViewer(const sys::Path &ExecPath,
-                            std::vector<const char*> &args,
-                            const sys::Path &Filename,
-                            bool wait,
-                            std::string &ErrMsg) {
+static bool LLVM_ATTRIBUTE_UNUSED
+ExecGraphViewer(const sys::Path &ExecPath, std::vector<const char*> &args,
+                const sys::Path &Filename, bool wait, std::string &ErrMsg) {
   if (wait) {
     if (sys::Program::ExecuteAndWait(ExecPath, &args[0],0,0,0,0,&ErrMsg)) {
       errs() << "Error: " << ErrMsg << "\n";