fix dataflow of return statement (#2244)

joernio · Feb 5, 2023 · 93ba087 · 93ba087
1 parent 7122dfd
commit 93ba087
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Showing 2 changed files with 27 additions and 1 deletion.
diff --git a/...engineoss/src/main/scala/io/joern/dataflowengineoss/passes/reachingdef/DdgGenerator.scala b/...engineoss/src/main/scala/io/joern/dataflowengineoss/passes/reachingdef/DdgGenerator.scala
@@ -114,7 +114,7 @@ class DdgGenerator(semantics: Semantics) {
           .filterNot(x => numberToNode.get(x).contains(use))
           .flatMap(numberToNode.get)
           .foreach { inElemNode =>
-            addEdge(inElemNode, ret, nodeToEdgeLabel(inElemNode))
+            addEdge(inElemNode, use, nodeToEdgeLabel(inElemNode))
           }
         if (inElements.isEmpty) {
           addEdge(method, ret)

diff --git a/...tends/javasrc2cpg/src/test/scala/io/joern/javasrc2cpg/querying/dataflow/ReturnTests.scala b/...tends/javasrc2cpg/src/test/scala/io/joern/javasrc2cpg/querying/dataflow/ReturnTests.scala
@@ -0,0 +1,26 @@
+package io.joern.javasrc2cpg.querying.dataflow
+
+import io.joern.javasrc2cpg.testfixtures.JavaDataflowFixture
+import io.joern.dataflowengineoss.language._
+import io.shiftleft.semanticcpg.language._
+
+class ReturnTests extends JavaDataflowFixture {
+
+  behavior of "Dataflow to return statements"
+
+  override val code: String =
+    """
+      |public class Foo {
+      | public void bar() {
+      |   int x = 42;
+      |   return x;
+      | }
+      |}
+      |""".stripMargin
+
+  it should "find a flow from x in return statement to 42" in {
+    val src = cpg.literal("42")
+    val snk = cpg.identifier("x").lineNumber(5)
+    snk.reachableBy(src).size shouldBe 1
+  }
+}