From 3e4ba898c17c5366e42c317dc73bf94954ec8d68 Mon Sep 17 00:00:00 2001
From: Bill Hoffman <bill.hoffman@kitware.com>
Date: Tue, 21 Jun 2011 15:59:10 -0400
Subject: [PATCH] Only pay for unused variable checking if it is on.

---
 Source/cmMakefile.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 63bf03bdd..014ef6793 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -1759,6 +1759,10 @@ void cmMakefile::AddDefinition(const char* name, bool value)
 
 void cmMakefile::CheckForUnusedVariables() const
 {
+  if (!this->WarnUnused)
+    {
+    return;
+    }
   const cmDefinitions& defs = this->Internal->VarStack.top();
   const std::set<cmStdString>& locals = defs.LocalKeys();
   std::set<cmStdString>::const_iterator it = locals.begin();