Add test for ObjFlow over binding patterns

java/ql/test/library-tests/object-tostring-flow-binding-patterns/Test.java

@@ -0,0 +1,29 @@
+public class Test {
+
+  interface Intf { }
+  static class Specific implements Intf { public String toString() { return "Specific"; } }
+  static class Alternative implements Intf { public String toString() { return "Alternative"; } }
+
+  public static String caller() {
+
+    Alternative a = new Alternative(); // Instantiate this somewhere so there are at least two candidate types in general
+    return test(new Specific());
+
+  }
+
+  public static String test(Object o) {
+
+    if (o instanceof Object o2) {
+      // So we should know o2.toString is really Specific.toString():
+      return o2.toString();
+    }
+
+    switch (o) {
+      case Object o2 when o2.hashCode() > 0 -> { return o2.toString(); } // Same goes for this `o2`
+      default -> { return "Not an Intf"; }
+    }
+
+  }
+
+}
+

java/ql/test/library-tests/object-tostring-flow-binding-patterns/options

@@ -0,0 +1 @@
+//semmle-extractor-options: --javac-args --release 21

java/ql/test/library-tests/object-tostring-flow-binding-patterns/test.expected

@@ -0,0 +1,9 @@
+| Test.java:1:14:1:17 | super(...) | java.lang.Object.Object |
+| Test.java:4:16:4:23 | super(...) | java.lang.Object.Object |
+| Test.java:5:16:5:26 | super(...) | java.lang.Object.Object |
+| Test.java:9:21:9:37 | new Alternative(...) | Test$Alternative.Alternative |
+| Test.java:10:12:10:31 | test(...) | Test.test |
+| Test.java:10:17:10:30 | new Specific(...) | Test$Specific.Specific |
+| Test.java:18:14:18:26 | toString(...) | Test$Specific.toString |
+| Test.java:22:27:22:39 | hashCode(...) | java.lang.Object.hashCode |
+| Test.java:22:57:22:69 | toString(...) | Test$Specific.toString |

java/ql/test/library-tests/object-tostring-flow-binding-patterns/test.ql

@@ -0,0 +1,7 @@
+import java
+
+import semmle.code.java.dispatch.VirtualDispatch
+
+from Call c, Callable c2
+where c2 = viableCallable(c)
+select c, c2.getQualifiedName()