cache AccessPath::getAnInstanceIn

Author: erik-krogh

javascript/ql/src/semmle/javascript/dataflow/internal/AccessPaths.qll

@@ -16,6 +16,7 @@
  */
 
 import javascript
+private import semmle.javascript.internal.CachedStages
 
 /**
  * A representation of a property name that is either statically known or is
@@ -88,7 +89,9 @@ class AccessPath extends TAccessPath {
   /**
    * Gets an expression in `bb` represented by this access path.
    */
+  cached
   Expr getAnInstanceIn(BasicBlock bb) {
+    Stages::DataFlowStage::ref() and
     exists(SsaVariable var |
       this = MkSsaRoot(var) and
       result = getARefinementOf*(var).getAUseIn(bb)

javascript/ql/src/semmle/javascript/internal/CachedStages.qll

@@ -24,6 +24,7 @@ import javascript
 private import StmtContainers
 private import semmle.javascript.dataflow.internal.PreCallGraphStep
 private import semmle.javascript.dataflow.internal.FlowSteps
+private import semmle.javascript.dataflow.internal.AccessPaths
 
 /**
  * Contains a `cached module` for each stage.
@@ -130,6 +131,8 @@ module Stages {
       any(DataFlow::Node node).hasLocationInfo(_, _, _, _, _)
       or
       exists(any(DataFlow::Node node).toString())
+      or
+      exists(any(AccessPath a).getAnInstanceIn(_))
     }
   }