diff --git a/Source/cmGeneratorExpression.h b/Source/cmGeneratorExpression.h
index 713b9ce4e1..b8467c27c2 100644
--- a/Source/cmGeneratorExpression.h
+++ b/Source/cmGeneratorExpression.h
@@ -19,7 +19,7 @@ class cmTarget;
 class cmMakefile;
 class cmListFileBacktrace;
 
-class cmGeneratorExpressionEvaluator;
+struct cmGeneratorExpressionEvaluator;
 
 class cmCompiledGeneratorExpression;
 
@@ -42,12 +42,11 @@ public:
   const cmCompiledGeneratorExpression& Parse(std::string const& input);
   const cmCompiledGeneratorExpression& Parse(const char* input);
 
-private:
-  cmListFileBacktrace const& Backtrace;
 private:
   cmGeneratorExpression(const cmGeneratorExpression &);
   void operator=(const cmGeneratorExpression &);
 
+  cmListFileBacktrace const& Backtrace;
   cmCompiledGeneratorExpression *CompiledExpression;
 };
 
@@ -65,21 +64,19 @@ public:
 
 private:
   cmCompiledGeneratorExpression(cmListFileBacktrace const& backtrace,
-                      std::vector<cmGeneratorExpressionEvaluator*> evaluators,
-                      const char *input, bool needsParsing);
+              const std::vector<cmGeneratorExpressionEvaluator*> &evaluators,
+              const char *input, bool needsParsing);
 
   friend class cmGeneratorExpression;
 
-private:
-  const std::vector<cmGeneratorExpressionEvaluator*> Evaluators;
-  cmListFileBacktrace const& Backtrace;
+  cmCompiledGeneratorExpression(const cmCompiledGeneratorExpression &);
+  void operator=(const cmCompiledGeneratorExpression &);
 
-  mutable std::set<cmTarget*> Targets;
+  cmListFileBacktrace const& Backtrace;
+  const std::vector<cmGeneratorExpressionEvaluator*> Evaluators;
   const char* const Input;
   const bool NeedsParsing;
 
+  mutable std::set<cmTarget*> Targets;
   mutable std::string Output;
-private:
-  cmCompiledGeneratorExpression(const cmCompiledGeneratorExpression &);
-  void operator=(const cmCompiledGeneratorExpression &);
 };
diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index 194749c23b..cf249486c2 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -56,9 +56,9 @@ static const struct ZeroNode : public cmGeneratorExpressionNode
 {
   virtual bool GeneratesContent() const { return false; }
 
-  std::string Evaluate(const std::vector<std::string> &parameters,
-                       cmGeneratorExpressionContext *context,
-                       const GeneratorExpressionContent *content) const
+  std::string Evaluate(const std::vector<std::string> &,
+                       cmGeneratorExpressionContext *,
+                       const GeneratorExpressionContent *) const
   {
     // Unreachable
     return std::string();
@@ -70,9 +70,9 @@ static const struct OneNode : public cmGeneratorExpressionNode
 {
   virtual bool AcceptsSingleArbitraryContentParameter() const { return true; }
 
-  std::string Evaluate(const std::vector<std::string> &parameters,
-                       cmGeneratorExpressionContext *context,
-                       const GeneratorExpressionContent *content) const
+  std::string Evaluate(const std::vector<std::string> &,
+                       cmGeneratorExpressionContext *,
+                       const GeneratorExpressionContent *) const
   {
     // Unreachable
     return std::string();
@@ -136,7 +136,7 @@ static const struct ConfigurationNode : public cmGeneratorExpressionNode
 {
   virtual int NumExpectedParameters() const { return 0; }
 
-  std::string Evaluate(const std::vector<std::string> &parameters,
+  std::string Evaluate(const std::vector<std::string> &,
                        cmGeneratorExpressionContext *context,
                        const GeneratorExpressionContent *) const
   {
@@ -428,7 +428,7 @@ std::string GeneratorExpressionContent::Evaluate(
   }
 
   int numExpected = node->NumExpectedParameters();
-  if ((numExpected != -1 && numExpected != parameters.size()))
+  if ((numExpected != -1 && unsigned int(numExpected) != parameters.size()))
     {
     if (numExpected == 0)
       {
diff --git a/Source/cmGeneratorExpressionParser.h b/Source/cmGeneratorExpressionParser.h
index 8bdb1a4950..28f14410fe 100644
--- a/Source/cmGeneratorExpressionParser.h
+++ b/Source/cmGeneratorExpressionParser.h
@@ -21,7 +21,7 @@
 
 class cmMakefile;
 class cmTarget;
-class cmGeneratorExpressionEvaluator;
+struct cmGeneratorExpressionEvaluator;
 
 //----------------------------------------------------------------------------
 struct cmGeneratorExpressionParser