Java: Add test for exception flow.

Author: aschackmull

java/ql/test/library-tests/dataflow/capture/B.java

@@ -279,4 +279,15 @@ String get() {
     sink(new MyLocal4().get()); // $ hasValueFlow=init
     sink(new MyLocal4(1).get()); // $ hasValueFlow=init
   }
+
+  void testCapturedCatch() {
+    try {
+      throw new RuntimeException(source("rte"));
+    } catch (RuntimeException e) {
+      Runnable r = () -> {
+        sink(e.getMessage()); // $ hasValueFlow=rte
+      };
+      r.run();
+    }
+  }
 }

java/ql/test/library-tests/dataflow/exceptions/A.java

@@ -0,0 +1,92 @@
+import java.util.*;
+
+public class A {
+  static String source(String tag) { return tag; }
+
+  static void sink(Object o) { }
+
+  static class MyException extends RuntimeException {
+    String msg;
+    MyException(String msg) {
+      this.msg = msg;
+    }
+  }
+
+  static class MySubException extends MyException {
+    MySubException(String msg) {
+      super(msg);
+    }
+  }
+
+  static class MyOtherException extends RuntimeException {
+    String msg;
+    MyOtherException(String msg) {
+      this.msg = msg;
+    }
+  }
+
+  void throwSome(int i) {
+    if (i == 1) throw new MyException(source("my"));
+    if (i == 2) throw new MySubException(source("sub"));
+    try {
+      if (i == 3) throw new MyOtherException(source("other"));
+    } catch (ClassCastException e) {
+    }
+  }
+
+  void foo(int i) {
+    try {
+      try {
+        throwSome(i);
+      } finally {
+      }
+    } catch (MySubException e) {
+      sink(e.msg); // $ hasValueFlow=sub SPURIOUS: hasValueFlow=my
+    } catch (MyException e) {
+      sink(e.msg); // $ hasValueFlow=my SPURIOUS: hasValueFlow=sub
+    } catch (MyOtherException e) {
+      sink(e.msg); // $ hasValueFlow=other
+    } catch (Exception e) {
+      sink(((MyOtherException)e).msg); // $ SPURIOUS: hasValueFlow=other
+    }
+  }
+
+  void throwArg(String msg) {
+    throw new MyException(msg);
+  }
+
+  void catchSummary() {
+    try {
+      throwArg(source("arg"));
+    } catch (MyException e) {
+      sink(e.msg); // $ hasValueFlow=arg
+    }
+  }
+
+  void runCallback(Runnable r) {
+    r.run();
+  }
+
+  void catchCallback() {
+    try {
+      runCallback(() -> { throw new MyException(source("cb")); });
+    } catch (MyException e) {
+      sink(e.msg); // $ hasValueFlow=cb
+    }
+
+    try {
+      List<String> l = Arrays.asList(new String[] { "s" });
+      l.forEach(s -> { throw new MyException(source("cb2")); });
+    } catch (MyException e) {
+      sink(e.msg); // $ hasValueFlow=cb2
+    }
+  }
+
+  void catchRuntimeException() {
+    try {
+      throw new RuntimeException(source("rte"));
+    } catch (RuntimeException e) {
+      sink(e.getMessage()); // $ hasValueFlow=rte
+    }
+  }
+}

java/ql/test/library-tests/dataflow/exceptions/flow.ql

@@ -0,0 +1,3 @@
+import utils.test.InlineFlowTest
+import DefaultFlowTest
+import ValueFlow::PathGraph