ENH: Improve dynamic variable scope implementation

Previously each new variable scope (subdirectory or function call) in
the CMake language created a complete copy of the key->value definition
map.  This avoids the copy using transitive lookups up the scope stack.
Results of queries answered by parents are stored locally to maintain
locality of reference.

The class cmDefinitions replaces cmMakefile::DefinitionsMap, and is
aware of its enclosing scope.  Each scope stores only the definitions
set (or unset!) inside it relative to the enclosing scope.

1 files changed, 2 insertions, 4 deletions

diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index 7a235f9..5cd3587 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -56,6 +56,8 @@ class cmCMakePolicyCommand;
  */
 class cmMakefile
 {
+  class Internals;
+  cmsys::auto_ptr<Internals> Internal;
 public:
   /**
    * Return the major and minor version of the cmake that
@@ -792,7 +794,6 @@ public:
   // Get the properties
   cmPropertyMap &GetProperties() { return this->Properties; };
 
-  typedef std::map<cmStdString, cmStdString> DefinitionMap;
   ///! Initialize a makefile from its parent
   void InitializeFromParent();
   
@@ -889,7 +890,6 @@ protected:
   std::vector<cmSourceGroup> SourceGroups;
 #endif
 
-  std::vector<DefinitionMap> DefinitionStack;
   std::vector<cmCommand*> UsedCommands;
   cmLocalGenerator* LocalGenerator;
   bool IsFunctionBlocked(const cmListFileFunction& lff, 
@@ -924,8 +924,6 @@ private:
   StringStringMap MacrosMap;
 
   std::map<cmStdString, bool> SubDirectoryOrder;
-  // used in AddDefinition for performance improvement
-  DefinitionMap::key_type  TemporaryDefinitionKey;
 
   cmsys::RegularExpression cmDefineRegex;
   cmsys::RegularExpression cmDefine01Regex;