Add def-use code sample and query

cruft/snapshot-query-1

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+usage="Take a snapshot of the current session1.ql
+
+Usage:
+    $0 TheSnapShotName
+"
+if [ $# -ne 1 ]
+then
+    echo "$usage"
+    exit 1
+fi
+
+if [ "$1" = "-h" ]
+then
+    echo "$usage"
+    exit 1
+fi
+
+qname=$1
+# create the tests
+mkdir -p tests/$qname
+touch tests/$qname/$qname.expected
+echo $qname.ql > tests/$qname/$qname.qlref     
+git add tests/$qname/$qname.expected
+git add tests/$qname/$qname.qlref
+
+# snapshot the session
+cp sample-utility-0.js tests/$qname/
+git add tests/$qname/sample-utility-0.js
+
+cp sample-utility-1.js tests/$qname/
+git add tests/$qname/sample-utility-1.js
+
+cp session/session1.ql solutions/$qname.ql
+git add solutions/$qname.ql

cruft/snapshot-setup

@@ -11,5 +11,6 @@ then
 fi
 mkdir -p tests
 mkdir -p solutions
-echo 'import javascript' > session.ql
+echo 'import javascript' > session/session.ql
+echo 'import javascript' > session/session1.ql
 

solutions/DefUseSample.ql

@@ -0,0 +1,80 @@
+/**
+ * @kind path-problem
+ * @problem.severity warning
+ * @id javascript/example/multiflow
+ */
+
+import javascript
+// XX: debug flow query
+// import semmle.javascript.explore.ForwardDataFlow
+import DataFlow::PathGraph
+
+// Flow to consider:
+//
+// var value = this.getParameter('value'); //: source 1
+// var ua = new GR('status');              //: source 2
+// ua.setValue('status',value);            //: taint step
+// ua.update();                            //: sink (if from source 2)
+
+// var value = this.getParameter('value'); //: source 1
+class ParameterSource extends CallExpr {
+  ParameterSource() {
+    exists(Expr inst |
+      this.getCalleeName() = "getParameter" and
+      (this.getReceiver().(ThisExpr) = inst or this.getReceiver().(Identifier) = inst)
+    )
+  }
+}
+
+// ua.setValue('status',value);            //: taint step
+predicate setValueTaintStep(DataFlow::Node pred, DataFlow::Node succ) {
+  exists(DotExpr temp, MethodCallExpr mce, VarAccess gr, VarAccess postgr |
+    temp.getPropertyName() = "setValue" and
+    mce.getReceiver() = temp.getBase() and
+    gr = mce.getReceiver() and
+    pred.asExpr() = mce.getArgument(1) and
+    //
+    // Taint all accesses after setValue call.
+    // Trying data flow, this would be:
+    // succ = gr.flow().getASuccessor+() and
+    //
+    // Using control flow:
+    gr.getASuccessor+() = postgr and
+    succ.asExpr() = postgr
+  )
+}
+
+// ua.update();                            //: sink (if from source 2)
+DotExpr updateExpression() { result.getPropertyName() = "update" }
+
+VarRef recordUpdate() { result = updateExpression().getBase() }
+
+// var ua = new GR('status');     //: source 2
+class GR extends NewExpr {
+  GR() { this.getCalleeName() = "GR" }
+}
+
+class FromRequestToGrUpdate extends TaintTracking::Configuration {
+  FromRequestToGrUpdate() { this = "FromRequestToGrUpdate" }
+
+  override predicate isSource(DataFlow::Node source) {
+    exists(ParameterSource getParameter | source.asExpr() = getParameter)
+  }
+
+  override predicate isAdditionalTaintStep(DataFlow::Node pred, DataFlow::Node succ) {
+    setValueTaintStep(pred, succ)
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    exists(VarRef grUpdate |
+      sink.asExpr() = recordUpdate() and
+      grUpdate = sink.asExpr() and
+      grUpdate.getName() = "ua"
+    )
+  }
+}
+
+from FromRequestToGrUpdate dataflow, DataFlow::PathNode source, DataFlow::PathNode sink
+where dataflow.hasFlowPath(source, sink)
+select sink, source, sink, "Data flow from $@ to $@.", source, source.toString(), sink,
+  sink.toString()

tests/DefUseSample/DefUseSample.expected

@@ -0,0 +1,30 @@
+WARNING: Unused class GR (/Users/hohn/local/codeql-javascript-multiflow/solutions/DefUseSample.ql:53,7-9)
+nodes
+| sample-utility-0.js:5:6:5:39 | value |
+| sample-utility-0.js:5:14:5:39 | this.ge ... value') |
+| sample-utility-0.js:5:14:5:39 | this.ge ... value') |
+| sample-utility-0.js:17:27:17:31 | value |
+| sample-utility-0.js:18:6:18:7 | ua |
+| sample-utility-0.js:18:6:18:7 | ua |
+| sample-utility-1.js:2:9:2:42 | value |
+| sample-utility-1.js:2:17:2:42 | this.ge ... value') |
+| sample-utility-1.js:2:17:2:42 | this.ge ... value') |
+| sample-utility-1.js:14:23:14:27 | value |
+| sample-utility-1.js:15:2:15:3 | ua |
+| sample-utility-1.js:15:2:15:3 | ua |
+edges
+| sample-utility-0.js:5:6:5:39 | value | sample-utility-0.js:17:27:17:31 | value |
+| sample-utility-0.js:5:14:5:39 | this.ge ... value') | sample-utility-0.js:5:6:5:39 | value |
+| sample-utility-0.js:5:14:5:39 | this.ge ... value') | sample-utility-0.js:5:6:5:39 | value |
+| sample-utility-0.js:17:27:17:31 | value | sample-utility-0.js:17:27:17:31 | value |
+| sample-utility-0.js:17:27:17:31 | value | sample-utility-0.js:18:6:18:7 | ua |
+| sample-utility-0.js:17:27:17:31 | value | sample-utility-0.js:18:6:18:7 | ua |
+| sample-utility-1.js:2:9:2:42 | value | sample-utility-1.js:14:23:14:27 | value |
+| sample-utility-1.js:2:17:2:42 | this.ge ... value') | sample-utility-1.js:2:9:2:42 | value |
+| sample-utility-1.js:2:17:2:42 | this.ge ... value') | sample-utility-1.js:2:9:2:42 | value |
+| sample-utility-1.js:14:23:14:27 | value | sample-utility-1.js:14:23:14:27 | value |
+| sample-utility-1.js:14:23:14:27 | value | sample-utility-1.js:15:2:15:3 | ua |
+| sample-utility-1.js:14:23:14:27 | value | sample-utility-1.js:15:2:15:3 | ua |
+#select
+| sample-utility-0.js:18:6:18:7 | ua | sample-utility-0.js:5:14:5:39 | this.ge ... value') | sample-utility-0.js:18:6:18:7 | ua | Data flow from $@ to $@. | sample-utility-0.js:5:14:5:39 | this.ge ... value') | this.ge ... value') | sample-utility-0.js:18:6:18:7 | ua | ua |
+| sample-utility-1.js:15:2:15:3 | ua | sample-utility-1.js:2:17:2:42 | this.ge ... value') | sample-utility-1.js:15:2:15:3 | ua | Data flow from $@ to $@. | sample-utility-1.js:2:17:2:42 | this.ge ... value') | this.ge ... value') | sample-utility-1.js:15:2:15:3 | ua | ua |

tests/DefUseSample/DefUseSample.qlref

@@ -0,0 +1 @@
+DefUseSample.ql

tests/DefUseSample/sample-utility-0.js

@@ -0,0 +1,23 @@
+var SampleUtility = function(){};
+SampleUtility.prototype = Object.extendsObject(Processor, {
+    
+    setUserStatus: function() {
+	var value = this.getParameter('value');
+
+	var ua = new GR('users');
+	ua.query();
+	
+	if(!ua.hasNext()){
+	    ua.initialize();
+	    ua.setValue('status',value);
+	    ua.insert();
+	}
+	else {
+	    ua.next();
+	    ua.setValue('status',value);
+	    ua.update();
+	}
+    },
+    
+    type: 'SampleUtility'
+});

tests/DefUseSample/sample-utility-1.js

@@ -0,0 +1,17 @@
+var SampleUtility = function() {
+    var value = this.getParameter('value');
+
+    var ua = new GR('users');
+    ua.query();
+    
+    if(!ua.hasNext()){
+	ua.initialize();
+	ua.setValue('status',value);
+	ua.insert();
+    }
+    else {
+	ua.next();
+	ua.setValue('status',value);
+	ua.update();
+    }
+}