cmMakefile: Raise variable in scope explicitly when needed.

The Get method implicitly pulls a copy of all variables into a local scope. This
is not necessary.

Source/cmDefinitions.cxx

@@ -18,7 +18,7 @@ cmDefinitions::Def cmDefinitions::NoDef;
 
 //----------------------------------------------------------------------------
 cmDefinitions::Def const& cmDefinitions::GetInternal(
-  const std::string& key, StackIter begin, StackIter end)
+  const std::string& key, StackIter begin, StackIter end, bool raise)
 {
   assert(begin != end);
   MapType::const_iterator i = begin->Map.find(key);
@@ -32,7 +32,11 @@ cmDefinitions::Def const& cmDefinitions::GetInternal(
     {
     return cmDefinitions::NoDef;
     }
-  Def const& def = cmDefinitions::GetInternal(key, it, end);
+  Def const& def = cmDefinitions::GetInternal(key, it, end, raise);
+  if (!raise)
+    {
+    return def;
+    }
   return begin->Map.insert(MapType::value_type(key, def)).first->second;
 }
 
@@ -40,10 +44,16 @@ cmDefinitions::Def const& cmDefinitions::GetInternal(
 const char* cmDefinitions::Get(const std::string& key,
     StackIter begin, StackIter end)
 {
-  Def const& def = cmDefinitions::GetInternal(key, begin, end);
+  Def const& def = cmDefinitions::GetInternal(key, begin, end, false);
   return def.Exists? def.c_str() : 0;
 }
 
+void cmDefinitions::Raise(const std::string& key,
+                          StackIter begin, StackIter end)
+{
+  cmDefinitions::GetInternal(key, begin, end, true);
+}
+
 //----------------------------------------------------------------------------
 void cmDefinitions::Set(const std::string& key, const char* value)
 {

Source/cmDefinitions.h

@@ -35,11 +35,11 @@ class cmDefinitions
   typedef std::list<cmDefinitions>::reverse_iterator StackIter;
   typedef std::list<cmDefinitions>::const_reverse_iterator StackConstIter;
 public:
-  /** Get the value associated with a key; null if none.
-      Store the result locally if it came from a parent.  */
   static const char* Get(const std::string& key,
                          StackIter begin, StackIter end);
 
+  static void Raise(const std::string& key, StackIter begin, StackIter end);
+
   /** Set (or unset if null) a value associated with a key.  */
   void Set(const std::string& key, const char* value);
 
@@ -80,7 +80,7 @@ private:
   MapType Map;
 
   static Def const& GetInternal(const std::string& key,
-    StackIter begin, StackIter end);
+    StackIter begin, StackIter end, bool raise);
 };
 
 #endif

Source/cmMakefile.cxx

@@ -130,7 +130,7 @@ public:
       return true;
       }
     // First localize the definition in the current scope.
-    this->GetDefinition(var);
+    cmDefinitions::Raise(var, this->VarStack.rbegin(), this->VarStack.rend());
 
     // Now update the definition in the parent scope.
     it->Set(var, varDef);