WIP

vladima · vladima · commit 21a9338e527f · 2016-11-23T17:09:04.000-08:00
diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
@@ -125,6 +125,8 @@ namespace ts {
         // state used for emit helpers
         let emitFlags: NodeFlags;
 
+        let clonedNodeMarker = 0;
+
         // If this file is an external module, then it is automatically in strict-mode according to
         // ES6.  If it is not an external module, then we'll determine if it is in strict mode or
         // not depending on if we see "use strict" in certain places or if we hit a class/namespace
@@ -150,6 +152,7 @@ namespace ts {
             classifiableNames = createMap<string>();
             symbolCount = 0;
             skipTransformFlagAggregation = isDeclarationFile(file);
+            clonedNodeMarker = 0;
 
             Symbol = objectAllocator.getSymbolConstructor();
 
@@ -775,6 +778,21 @@ namespace ts {
             }
         }
 
+        function markClonableFlowNodes<T extends FlowNode>(flowNode: T): T {
+            if (clonedNodeMarker !== 0) {
+                flowNode.flags |= clonedNodeMarker << 22;
+            }
+            return flowNode;
+        }
+
+        function getFlowNodeMarker(flowNode: FlowNode): number {
+            return flowNode.flags >> 22;
+        }
+
+        function resetFlowNodeMarker(flowNode: FlowNode): void {
+            flowNode.flags &= 
+        }
+
         function createFlowCondition(flags: FlowFlags, antecedent: FlowNode, expression: Expression): FlowNode {
             if (antecedent.flags & FlowFlags.Unreachable) {
                 return antecedent;
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -2055,7 +2055,9 @@ namespace ts {
         Referenced     = 1 << 9,  // Referenced as antecedent once
         Shared         = 1 << 10, // Referenced as antecedent more than once
         Label = BranchLabel | LoopLabel,
-        Condition = TrueCondition | FalseCondition
+        Condition = TrueCondition | FalseCondition,
+
+        // range from 22-29 bits is reserved for marking flow nodes that should be cloned during binding
     }
 
     export interface FlowNode {
