Data flow: Cache nodeIsHidden

Author: hvitved

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll

@@ -2986,7 +2986,7 @@ class PathNode extends TPathNode {
   Configuration getConfiguration() { none() }
 
   private predicate isHidden() {
-    nodeIsHidden(this.getNode()) and
+    hiddenNode(this.getNode()) and
     not this.isSource() and
     not this instanceof PathNodeSink
   }

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll

@@ -244,6 +244,14 @@ private DataFlowCallable viableCallableExt(DataFlowCall call) {
 
 cached
 private module Cached {
+  /**
+   * If needed, call this predicate from `DataFlowImplSpecific.qll` in order to
+   * force a stage-dependency on the `DataFlowImplCommon.qll` stage and therby
+   * collapsing the two stages.
+   */
+  cached
+  predicate forceCachingInSameStage() { any() }
+
   cached
   predicate nodeEnclosingCallable(Node n, DataFlowCallable c) { c = n.getEnclosingCallable() }
 
@@ -271,6 +279,9 @@ private module Cached {
     n.(PostUpdateNode).getPreUpdateNode() instanceof ArgumentNodeExt
   }
 
+  cached
+  predicate hiddenNode(Node n) { nodeIsHidden(n) }
+
   cached
   OutNodeExt getAnOutNodeExt(DataFlowCall call, ReturnKindExt k) {
     result = getAnOutNode(call, k.(ValueReturnKind).getKind())