diff --git a/Source/cmCustomCommandGenerator.cxx b/Source/cmCustomCommandGenerator.cxx
index 07df7d5e0..f2f77eea0 100644
--- a/Source/cmCustomCommandGenerator.cxx
+++ b/Source/cmCustomCommandGenerator.cxx
@@ -47,7 +47,7 @@ std::string cmCustomCommandGenerator::GetCommand(unsigned int c) const
     {
     return target->GetLocation(this->Config);
     }
-  return this->GE->Parse(argv0).Evaluate(this->Makefile, this->Config);
+  return this->GE->Parse(argv0)->Evaluate(this->Makefile, this->Config);
 }
 
 //----------------------------------------------------------------------------
@@ -58,7 +58,7 @@ cmCustomCommandGenerator
   cmCustomCommandLine const& commandLine = this->CC.GetCommandLines()[c];
   for(unsigned int j=1;j < commandLine.size(); ++j)
     {
-    std::string arg = this->GE->Parse(commandLine[j]).Evaluate(this->Makefile,
+    std::string arg = this->GE->Parse(commandLine[j])->Evaluate(this->Makefile,
                                                                this->Config);
     cmd += " ";
     if(this->OldStyle)
diff --git a/Source/cmGeneratorExpression.cxx b/Source/cmGeneratorExpression.cxx
index 32bf941eb..3fd4a5f8e 100644
--- a/Source/cmGeneratorExpression.cxx
+++ b/Source/cmGeneratorExpression.cxx
@@ -25,44 +25,29 @@
 //----------------------------------------------------------------------------
 cmGeneratorExpression::cmGeneratorExpression(
   cmListFileBacktrace const& backtrace):
-  Backtrace(backtrace), CompiledExpression(0)
+  Backtrace(backtrace)
 {
 }
 
 //----------------------------------------------------------------------------
-const cmCompiledGeneratorExpression &
+cmsys::auto_ptr<cmCompiledGeneratorExpression>
 cmGeneratorExpression::Parse(std::string const& input)
 {
   return this->Parse(input.c_str());
 }
 
 //----------------------------------------------------------------------------
-const cmCompiledGeneratorExpression &
+cmsys::auto_ptr<cmCompiledGeneratorExpression>
 cmGeneratorExpression::Parse(const char* input)
 {
-  cmGeneratorExpressionLexer l;
-  std::vector<cmGeneratorExpressionToken> tokens = l.Tokenize(input);
-  bool needsParsing = l.GetSawGeneratorExpression();
-  std::vector<cmGeneratorExpressionEvaluator*> evaluators;
-
-  if (needsParsing)
-    {
-    cmGeneratorExpressionParser p(tokens);
-    p.Parse(evaluators);
-    }
-
-  delete this->CompiledExpression;
-  this->CompiledExpression = new cmCompiledGeneratorExpression(
-                                      this->Backtrace,
-                                      evaluators,
-                                      input,
-                                      needsParsing);
-  return *this->CompiledExpression;
+  return cmsys::auto_ptr<cmCompiledGeneratorExpression>(
+                                      new cmCompiledGeneratorExpression(
+                                        this->Backtrace,
+                                        input));
 }
 
 cmGeneratorExpression::~cmGeneratorExpression()
 {
-  delete this->CompiledExpression;
 }
 
 //----------------------------------------------------------------------------
@@ -73,7 +58,7 @@ const char *cmCompiledGeneratorExpression::Evaluate(
 {
   if (!this->NeedsParsing)
     {
-    return this->Input;
+    return this->Input.c_str();
     }
 
   this->Output = "";
@@ -108,12 +93,19 @@ const char *cmCompiledGeneratorExpression::Evaluate(
 
 cmCompiledGeneratorExpression::cmCompiledGeneratorExpression(
               cmListFileBacktrace const& backtrace,
-              const std::vector<cmGeneratorExpressionEvaluator*> &evaluators,
-              const char *input, bool needsParsing)
-  : Backtrace(backtrace), Evaluators(evaluators), Input(input),
-    NeedsParsing(needsParsing)
+              const char *input)
+  : Backtrace(backtrace), Input(input ? input : "")
 {
+  cmGeneratorExpressionLexer l;
+  std::vector<cmGeneratorExpressionToken> tokens =
+                                              l.Tokenize(this->Input.c_str());
+  this->NeedsParsing = l.GetSawGeneratorExpression();
 
+  if (this->NeedsParsing)
+    {
+    cmGeneratorExpressionParser p(tokens);
+    p.Parse(this->Evaluators);
+    }
 }
 
 
diff --git a/Source/cmGeneratorExpression.h b/Source/cmGeneratorExpression.h
index ea3e7d03b..961e53d75 100644
--- a/Source/cmGeneratorExpression.h
+++ b/Source/cmGeneratorExpression.h
@@ -14,10 +14,12 @@
 #define cmGeneratorExpression_h
 
 #include "cmStandardIncludes.h"
+#include "cmListFileCache.h"
 
 #include <stack>
 
 #include <cmsys/RegularExpression.hxx>
+#include <cmsys/auto_ptr.hxx>
 
 class cmTarget;
 class cmMakefile;
@@ -44,8 +46,9 @@ public:
   cmGeneratorExpression(cmListFileBacktrace const& backtrace);
   ~cmGeneratorExpression();
 
-  const cmCompiledGeneratorExpression& Parse(std::string const& input);
-  const cmCompiledGeneratorExpression& Parse(const char* input);
+  cmsys::auto_ptr<cmCompiledGeneratorExpression> Parse(
+                                                std::string const& input);
+  cmsys::auto_ptr<cmCompiledGeneratorExpression> Parse(const char* input);
 
   enum PreprocessContext {
     StripAllGeneratorExpressions
@@ -59,7 +62,6 @@ private:
   void operator=(const cmGeneratorExpression &);
 
   cmListFileBacktrace const& Backtrace;
-  cmCompiledGeneratorExpression *CompiledExpression;
 };
 
 class cmCompiledGeneratorExpression
@@ -76,20 +78,24 @@ public:
 
   ~cmCompiledGeneratorExpression();
 
+  std::string GetInput() const
+  {
+    return this->Input;
+  }
+
 private:
   cmCompiledGeneratorExpression(cmListFileBacktrace const& backtrace,
-              const std::vector<cmGeneratorExpressionEvaluator*> &evaluators,
-              const char *input, bool needsParsing);
+              const char *input);
 
   friend class cmGeneratorExpression;
 
   cmCompiledGeneratorExpression(const cmCompiledGeneratorExpression &);
   void operator=(const cmCompiledGeneratorExpression &);
 
-  cmListFileBacktrace const& Backtrace;
-  const std::vector<cmGeneratorExpressionEvaluator*> Evaluators;
-  const char* const Input;
-  const bool NeedsParsing;
+  cmListFileBacktrace Backtrace;
+  std::vector<cmGeneratorExpressionEvaluator*> Evaluators;
+  const std::string Input;
+  bool NeedsParsing;
 
   mutable std::set<cmTarget*> Targets;
   mutable std::string Output;
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index de8b5e369..55507ddf3 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -267,7 +267,7 @@ std::vector<std::string> cmGeneratorTarget::GetIncludeDirectories(
                                               "INCLUDE_DIRECTORIES", 0, 0);
 
   cmSystemTools::ExpandListArgument(ge.Parse(prop)
-                                    .Evaluate(this->Makefile,
+                                    ->Evaluate(this->Makefile,
                                               config,
                                               false,
                                               this->Target,
@@ -315,7 +315,7 @@ std::string cmGeneratorTarget::GetCompileDefinitions(const char *config)
   cmGeneratorExpressionDAGChecker dagChecker(lfbt,
                                              this->GetName(),
                                              defPropName, 0, 0);
-  return ge.Parse(prop).Evaluate(this->Makefile,
+  return ge.Parse(prop)->Evaluate(this->Makefile,
                                  config,
                                  false,
                                  this->Target,
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index de3b23c78..e7b34ee42 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -1728,9 +1728,10 @@ cmTargetTraceDependencies
     for(cmCustomCommandLine::const_iterator cli = cit->begin();
         cli != cit->end(); ++cli)
       {
-      const cmCompiledGeneratorExpression &cge = ge.Parse(*cli);
-      cge.Evaluate(this->Makefile, 0, true);
-      std::set<cmTarget*> geTargets = cge.GetTargets();
+      const cmsys::auto_ptr<cmCompiledGeneratorExpression> cge
+                                                              = ge.Parse(*cli);
+      cge->Evaluate(this->Makefile, 0, true);
+      std::set<cmTarget*> geTargets = cge->GetTargets();
       for(std::set<cmTarget*>::const_iterator it = geTargets.begin();
           it != geTargets.end(); ++it)
         {
diff --git a/Source/cmTestGenerator.cxx b/Source/cmTestGenerator.cxx
index 2f650e72e..42f511ea3 100644
--- a/Source/cmTestGenerator.cxx
+++ b/Source/cmTestGenerator.cxx
@@ -112,7 +112,7 @@ void cmTestGenerator::GenerateScriptForConfig(std::ostream& os,
   else
     {
     // Use the command name given.
-    exe = ge.Parse(exe.c_str()).Evaluate(mf, config);
+    exe = ge.Parse(exe.c_str())->Evaluate(mf, config);
     cmSystemTools::ConvertToUnixSlashes(exe);
     }
 
@@ -122,7 +122,7 @@ void cmTestGenerator::GenerateScriptForConfig(std::ostream& os,
   for(std::vector<std::string>::const_iterator ci = command.begin()+1;
       ci != command.end(); ++ci)
     {
-    os << " " << lg->EscapeForCMake(ge.Parse(*ci).Evaluate(mf, config));
+    os << " " << lg->EscapeForCMake(ge.Parse(*ci)->Evaluate(mf, config));
     }
 
   // Finish the test command.