From e17a69bc744ce0ed36e41be36694ca0053330d78 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <mathstuf@gmail.com>
Date: Wed, 12 Mar 2014 01:48:06 -0400
Subject: [PATCH] cmDefinitions: Use a hashmap for faster checks

The hash map is much faster at checking that the map won't have what
we're looking for so that we can just go to the parent scope instead.
---
 Source/cmDefinitions.cxx | 5 +++--
 Source/cmDefinitions.h   | 7 +++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Source/cmDefinitions.cxx b/Source/cmDefinitions.cxx
index 650216379..5515f3551 100644
--- a/Source/cmDefinitions.cxx
+++ b/Source/cmDefinitions.cxx
@@ -15,7 +15,8 @@
 cmDefinitions::Def cmDefinitions::NoDef;
 
 //----------------------------------------------------------------------------
-cmDefinitions::cmDefinitions(cmDefinitions* parent): Up(parent)
+cmDefinitions::cmDefinitions(cmDefinitions* parent)
+  : Up(parent)
 {
 }
 
@@ -35,7 +36,7 @@ cmDefinitions::GetInternal(const std::string& key) const
     {
     return i->second;
     }
-  else if(cmDefinitions* up = this->Up)
+  if(cmDefinitions* up = this->Up)
     {
     // Query the parent scope.
     return up->GetInternal(key);
diff --git a/Source/cmDefinitions.h b/Source/cmDefinitions.h
index ebe6fa5f3..5209a8b20 100644
--- a/Source/cmDefinitions.h
+++ b/Source/cmDefinitions.h
@@ -13,6 +13,9 @@
 #define cmDefinitions_h
 
 #include "cmStandardIncludes.h"
+#if defined(CMAKE_BUILD_WITH_CMAKE)
+#include "cmsys/hash_map.hxx"
+#endif
 
 /** \class cmDefinitions
  * \brief Store a scope of variable definitions for CMake language.
@@ -71,7 +74,11 @@ private:
   cmDefinitions* Up;
 
   // Local definitions, set or unset.
+#if defined(CMAKE_BUILD_WITH_CMAKE)
+  typedef cmsys::hash_map<std::string, Def> MapType;
+#else
   typedef std::map<std::string, Def> MapType;
+#endif
   MapType Map;
 
   // Internal query and update methods.