CLJ-2414 Fix reflective lookup to include interfaces which may contain default methods

puredanger · stuarthalloway · commit dddc4124da88 · 2018-10-09T16:39:36.000-04:00
Signed-off-by: Stuart Halloway &lt;stu@cognitect.com&gt;
diff --git a/src/jvm/clojure/lang/Reflector.java b/src/jvm/clojure/lang/Reflector.java
@@ -19,9 +19,7 @@
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
+import java.util.*;
 import java.util.stream.Collectors;
 
 public class Reflector{
@@ -58,17 +56,41 @@ private static boolean canAccess(Method m, Object target) {
 	}
 }
 
+private static Collection<Class> interfaces(Class c) {
+	Set<Class> interfaces = new HashSet<Class>();
+	Deque<Class> toWalk = new ArrayDeque<Class>();
+	toWalk.addAll(Arrays.asList(c.getInterfaces()));
+	Class iface = toWalk.poll();
+	while (iface != null) {
+		interfaces.add(iface);
+		toWalk.addAll(Arrays.asList(iface.getInterfaces()));
+		iface = toWalk.poll();
+	}
+	return interfaces;
+}
+
+private static Method tryFindMethod(Class c, Method m) {
+	if(c == null) return null;
+	try {
+		return c.getMethod(m.getName(), m.getParameterTypes());
+	} catch(NoSuchMethodException e) {
+		return null;
+	}
+}
+
 private static Method toAccessibleSuperMethod(Method m, Object target) {
 	Method selected = m;
-	while(selected != null && !canAccess(selected, target)) {
-		Class<?> s = selected.getDeclaringClass().getSuperclass();
-		try {
-			selected = s.getMethod(m.getName(), m.getParameterTypes());
-		} catch(NoSuchMethodException e) {
-			// ignore
-		}
+	while(selected != null) {
+		if(canAccess(selected, target)) return selected;
+		selected = tryFindMethod(selected.getDeclaringClass().getSuperclass(), m);
 	}
-	return selected;
+
+	Collection<Class> interfaces = interfaces(m.getDeclaringClass());
+	for(Class c : interfaces) {
+		selected = tryFindMethod(c, m);
+		if(selected != null) return selected;
+	}
+	return null;
 }
 
 public static Object invokeInstanceMethod(Object target, String methodName, Object[] args) {
diff --git a/test/clojure/test_clojure/reflect.clj b/test/clojure/test_clojure/reflect.clj
@@ -36,4 +36,19 @@
 
 (def inst (IBar$Factory/get))
 (deftest invoking-nonpublic-super
-  (is (= "stuff" (.stuff inst))))
+  (is (= "stuff" (.stuff inst))))
+
+(defn- checkCLJ2066 [f]
+  ;; intentionally reflective call
+  (is (not (nil? (.createXMLStreamReader f (java.io.StringReader. ""))))))
+
+(defn- checkCLJ2414 [p]
+  ;; intentionally reflective call
+  (is (false? (.startsWith p "s"))))
+
+(deftest invoke-checks-accessibility
+  ;; CLJ-2066 - reflector finds method in private class. this is invokable, but an illegal access per modules
+  (checkCLJ2066 (javax.xml.stream.XMLInputFactory/newInstance))
+
+  ;; CLJ-2414 - find default method on interface of inaccessible class
+  (checkCLJ2414 (java.nio.file.Paths/get "src" (into-array String []))))
