cmState: Add a VariableScope snapshot type.

Match the scopes currently used in cmMakefile for definitions.

Source/cmMakefile.cxx

@@ -4464,6 +4464,17 @@ void cmMakefile::PushScope()
 {
   this->Internal->PushDefinitions(Internals::VariableScope);
 
+  std::string commandName;
+  long line = 0;
+  if (!this->ContextStack.empty())
+    {
+    commandName = this->ContextStack.back()->Name;
+    line = this->ContextStack.back()->Line;
+    }
+  this->StateSnapshot = this->GetState()->CreateVariableScopeSnapshot(
+        this->StateSnapshot,
+        commandName,
+        line);
   this->PushLoopBlockBarrier();
 
 #if defined(CMAKE_BUILD_WITH_CMAKE)
@@ -4482,6 +4493,9 @@ void cmMakefile::PopScope()
   this->CheckForUnusedVariables();
 
   this->Internal->PopDefinitions();
+  this->StateSnapshot =
+      this->GetState()->Pop(this->StateSnapshot);
+  assert(this->StateSnapshot.IsValid());
 }
 
 void cmMakefile::RaiseScope(const std::string& var, const char *varDef)

Source/cmState.cxx

@@ -20,6 +20,7 @@
 
 struct cmState::SnapshotDataType
 {
+  cmState::PositionType ScopeParent;
   cmState::PositionType DirectoryParent;
   cmLinkedTree<cmState::PolicyStackEntry>::iterator Policies;
   cmLinkedTree<cmState::PolicyStackEntry>::iterator PolicyRoot;
@@ -736,6 +737,7 @@ cmState::Snapshot cmState::CreateBaseSnapshot()
 {
   PositionType pos = this->SnapshotData.Extend(this->SnapshotData.Root());
   pos->DirectoryParent = this->SnapshotData.Root();
+  pos->ScopeParent = this->SnapshotData.Root();
   pos->SnapshotType = BaseType;
   pos->BuildSystemDirectory =
       this->BuildsystemDirectory.Extend(this->BuildsystemDirectory.Root());
@@ -763,6 +765,7 @@ cmState::CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot,
   pos->EntryPointLine = entryPointLine;
   pos->EntryPointCommand = entryPointCommand;
   pos->DirectoryParent = originSnapshot.Position;
+  pos->ScopeParent = originSnapshot.Position;
   pos->SnapshotType = BuildsystemDirectoryType;
   pos->BuildSystemDirectory =
       this->BuildsystemDirectory.Extend(
@@ -787,6 +790,7 @@ cmState::CreateFunctionCallSnapshot(cmState::Snapshot originSnapshot,
 {
   PositionType pos = this->SnapshotData.Extend(originSnapshot.Position,
                                                *originSnapshot.Position);
+  pos->ScopeParent = originSnapshot.Position;
   pos->EntryPointLine = entryPointLine;
   pos->EntryPointCommand = entryPointCommand;
   pos->SnapshotType = FunctionCallType;
@@ -834,6 +838,21 @@ cmState::CreateCallStackSnapshot(cmState::Snapshot originSnapshot,
   return cmState::Snapshot(this, pos);
 }
 
+cmState::Snapshot
+cmState::CreateVariableScopeSnapshot(cmState::Snapshot originSnapshot,
+                                     std::string const& entryPointCommand,
+                                     long entryPointLine)
+{
+  PositionType pos = this->SnapshotData.Extend(originSnapshot.Position,
+                                               *originSnapshot.Position);
+  pos->ScopeParent = originSnapshot.Position;
+  pos->EntryPointLine = entryPointLine;
+  pos->EntryPointCommand = entryPointCommand;
+  pos->SnapshotType = VariableScopeType;
+
+  return cmState::Snapshot(this, pos);
+}
+
 cmState::Snapshot
 cmState::CreateInlineListFileSnapshot(cmState::Snapshot originSnapshot,
                                       const std::string& entryPointCommand,

Source/cmState.h

@@ -41,7 +41,8 @@ public:
     MacroCallType,
     CallStackType,
     InlineListFileType,
-    PolicyScopeType
+    PolicyScopeType,
+    VariableScopeType
   };
 
   class Directory;
@@ -155,6 +156,9 @@ public:
                                    std::string const& entryPointCommand,
                                    long entryPointLine,
                                    std::string const& fileName);
+  Snapshot CreateVariableScopeSnapshot(Snapshot originSnapshot,
+                                       std::string const& entryPointCommand,
+                                       long entryPointLine);
   Snapshot CreateInlineListFileSnapshot(Snapshot originSnapshot,
                                         const std::string& entryPointCommand,
                                         long entryPointLine,