cmDefinitions: Don't store parent lookups

When looking up scopes, it is faster to not store the lookup locally to
keep the maps smaller and avoid extra allocations and rebalancing.

1 files changed, 17 insertions, 5 deletions

diff --git a/Source/cmDefinitions.cxx b/Source/cmDefinitions.cxx
index babf1c4..98becf8 100644
--- a/Source/cmDefinitions.cxx
+++ b/Source/cmDefinitions.cxx
@@ -28,7 +28,7 @@ void cmDefinitions::Reset(cmDefinitions* parent)
 
 //----------------------------------------------------------------------------
 cmDefinitions::Def const&
-cmDefinitions::GetInternal(const std::string& key)
+cmDefinitions::GetInternal(const std::string& key) const
 {
   MapType::const_iterator i = this->Map.find(key);
   if(i != this->Map.end())
@@ -37,9 +37,8 @@ cmDefinitions::GetInternal(const std::string& key)
     }
   else if(cmDefinitions* up = this->Up)
     {
-    // Query the parent scope and store the result locally.
-    Def def = up->GetInternal(key);
-    return this->Map.insert(MapType::value_type(key, def)).first->second;
+    // Query the parent scope.
+    return up->GetInternal(key);
     }
   return this->NoDef;
 }
@@ -71,13 +70,26 @@ cmDefinitions::SetInternal(const std::string& key, Def const& def)
 }
 
 //----------------------------------------------------------------------------
-const char* cmDefinitions::Get(const std::string& key)
+const char* cmDefinitions::Get(const std::string& key) const
 {
   Def const& def = this->GetInternal(key);
   return def.Exists? def.c_str() : 0;
 }
 
 //----------------------------------------------------------------------------
+void cmDefinitions::Pull(const std::string& key)
+{
+  if (this->Up)
+    {
+    Def const& def = this->Up->GetInternal(key);
+    if (def.Exists)
+      {
+      this->SetInternal(key, def);
+      }
+    }
+}
+
+//----------------------------------------------------------------------------
 const char* cmDefinitions::Set(const std::string& key, const char* value)
 {
   Def const& def = this->SetInternal(key, Def(value));