Merge pull request github#3442 from erik-krogh/SmallPerfs

Approved by esbena

Author: semmle-qlci

javascript/ql/src/semmle/javascript/CFG.qll

@@ -379,8 +379,9 @@ class GuardControlFlowNode extends SyntheticControlFlowNode, @guard_node {
    * is known to hold at `bb`.
    */
   predicate dominates(ReachableBasicBlock bb) {
-    this = bb.getANode() or
-    dominates(bb.getImmediateDominator())
+    this = bb.getANode()
+    or
+    exists(ReachableBasicBlock prev | prev.strictlyDominates(bb) | this = prev.getANode())
   }
 }
 

javascript/ql/src/semmle/javascript/InclusionTests.qll

@@ -71,20 +71,22 @@ module InclusionTest {
       count(this.getACallee()) = 1 and
       count(callee.getAReturnedExpr()) = 1 and
       not this.isImprecise() and
-      inner.getContainerNode().getALocalSource().getEnclosingExpr() = callee.getAParameter() and
-      inner.getContainedNode().getALocalSource().getEnclosingExpr() = callee.getAParameter()
+      inner.getContainedNode().getALocalSource() = DataFlow::parameterNode(callee.getAParameter()) and
+      inner.getContainerNode().getALocalSource() = DataFlow::parameterNode(callee.getAParameter())
     }
 
     override DataFlow::Node getContainerNode() {
       exists(int arg |
-        inner.getContainerNode().getALocalSource().getEnclosingExpr() = callee.getParameter(arg) and
+        inner.getContainerNode().getALocalSource() =
+          DataFlow::parameterNode(callee.getParameter(arg)) and
         result = this.getArgument(arg)
       )
     }
 
     override DataFlow::Node getContainedNode() {
       exists(int arg |
-        inner.getContainedNode().getALocalSource().getEnclosingExpr() = callee.getParameter(arg) and
+        inner.getContainedNode().getALocalSource() =
+          DataFlow::parameterNode(callee.getParameter(arg)) and
         result = this.getArgument(arg)
       )
     }

javascript/ql/src/semmle/javascript/dataflow/Configuration.qll

@@ -726,21 +726,6 @@ private predicate basicFlowStepNoBarrier(
   summary = PathSummary::return()
 }
 
-/**
- * Holds if there is a flow step from `pred` to `succ` described by `summary`
- * under configuration `cfg`.
- *
- * Summary steps through function calls are not taken into account.
- */
-private predicate basicFlowStep(
-  DataFlow::Node pred, DataFlow::Node succ, PathSummary summary, DataFlow::Configuration cfg
-) {
-  basicFlowStepNoBarrier(pred, succ, summary, cfg) and
-  isRelevant(pred, cfg) and
-  not isLabeledBarrierEdge(cfg, pred, succ, summary.getStartLabel()) and
-  not isBarrierEdge(cfg, pred, succ)
-}
-
 /**
  * Holds if there is a flow step from `pred` to `succ` under configuration `cfg`,
  * including both basic flow steps and steps into/out of properties.
@@ -1339,7 +1324,8 @@ private predicate flowStep(
   DataFlow::Node pred, DataFlow::Configuration cfg, DataFlow::Node succ, PathSummary summary
 ) {
   (
-    basicFlowStep(pred, succ, summary, cfg)
+    basicFlowStepNoBarrier(pred, succ, summary, cfg) and
+    isRelevant(pred, cfg)
     or
     // Flow through a function that returns a value that depends on one of its arguments
     // or a captured variable