Merge V8 5.3.332.45. DO NOT MERGE
Test: Manual
FPIIM-449
Change-Id: Id3254828b068abdea3cb10442e0172a8c9a98e03
(cherry picked from commit 13e2dadd00298019ed862f2b2fc5068bba730bcf)
diff --git a/src/compiler/node-marker.h b/src/compiler/node-marker.h
index 5ef2063..84666d5 100644
--- a/src/compiler/node-marker.h
+++ b/src/compiler/node-marker.h
@@ -42,9 +42,22 @@
DISALLOW_COPY_AND_ASSIGN(NodeMarkerBase);
};
-
-// A NodeMarker uses monotonically increasing marks to assign local "states"
-// to nodes. Only one NodeMarker per graph is valid at a given time.
+// A NodeMarker assigns a local "state" to every node of a graph in constant
+// memory. Only one NodeMarker per graph is valid at a given time, that is,
+// after you create a NodeMarker you should no longer use NodeMarkers that
+// were created earlier. Internally, the local state is stored in the Node
+// structure.
+//
+// When you initialize a NodeMarker, all the local states are conceptually
+// set to State(0) in constant time.
+//
+// In its current implementation, in debug mode NodeMarker will try to
+// (efficiently) detect invalid use of an older NodeMarker. Namely, if you get
+// or set a node with a NodeMarker, and then get or set that node
+// with an older NodeMarker you will get a crash.
+//
+// GraphReducer uses a NodeMarker, so individual Reducers cannot use a
+// NodeMarker.
template <typename State>
class NodeMarker : public NodeMarkerBase {
public: