Fix broken JNI IsAssignableFrom.
The expected argument order was the opposite of what the spec
dictated.
Reported-By: Mikhail Naganov <mnaganov@google.com>
bug: 16531674
(cherry picked from commit 1268b742c8cff7318dc0b5b283cbaeabfe0725ba)
Change-Id: I2b6636998c4e15c1eb10dc96a57940aca56c4d0d
diff --git a/runtime/jni_internal.cc b/runtime/jni_internal.cc
index 845691d..d7200af 100644
--- a/runtime/jni_internal.cc
+++ b/runtime/jni_internal.cc
@@ -645,13 +645,15 @@
return soa.AddLocalReference<jclass>(c->GetSuperClass());
}
+ // Note: java_class1 should be safely castable to java_class2, and
+ // not the other way around.
static jboolean IsAssignableFrom(JNIEnv* env, jclass java_class1, jclass java_class2) {
CHECK_NON_NULL_ARGUMENT_RETURN(java_class1, JNI_FALSE);
CHECK_NON_NULL_ARGUMENT_RETURN(java_class2, JNI_FALSE);
ScopedObjectAccess soa(env);
mirror::Class* c1 = soa.Decode<mirror::Class*>(java_class1);
mirror::Class* c2 = soa.Decode<mirror::Class*>(java_class2);
- return c1->IsAssignableFrom(c2) ? JNI_TRUE : JNI_FALSE;
+ return c2->IsAssignableFrom(c1) ? JNI_TRUE : JNI_FALSE;
}
static jboolean IsInstanceOf(JNIEnv* env, jobject jobj, jclass java_class) {
diff --git a/runtime/jni_internal_test.cc b/runtime/jni_internal_test.cc
index 8ef1cb6..83ffae1 100644
--- a/runtime/jni_internal_test.cc
+++ b/runtime/jni_internal_test.cc
@@ -949,8 +949,28 @@
jclass string_class = env_->FindClass("java/lang/String");
ASSERT_NE(string_class, nullptr);
- ASSERT_TRUE(env_->IsAssignableFrom(object_class, string_class));
- ASSERT_FALSE(env_->IsAssignableFrom(string_class, object_class));
+ // A superclass is assignable from an instance of its
+ // subclass but not vice versa.
+ ASSERT_TRUE(env_->IsAssignableFrom(string_class, object_class));
+ ASSERT_FALSE(env_->IsAssignableFrom(object_class, string_class));
+
+ jclass charsequence_interface = env_->FindClass("java/lang/CharSequence");
+ ASSERT_NE(charsequence_interface, nullptr);
+
+ // An interface is assignable from an instance of an implementing
+ // class but not vice versa.
+ ASSERT_TRUE(env_->IsAssignableFrom(string_class, charsequence_interface));
+ ASSERT_FALSE(env_->IsAssignableFrom(charsequence_interface, string_class));
+
+ // Check that arrays are covariant.
+ jclass string_array_class = env_->FindClass("[Ljava/lang/String;");
+ ASSERT_NE(string_array_class, nullptr);
+ jclass object_array_class = env_->FindClass("[Ljava/lang/Object;");
+ ASSERT_NE(object_array_class, nullptr);
+ ASSERT_TRUE(env_->IsAssignableFrom(string_array_class, object_array_class));
+ ASSERT_FALSE(env_->IsAssignableFrom(object_array_class, string_array_class));
+
+ // Primitive types are tested in 004-JniTest.
// Null as either class should fail.
CheckJniAbortCatcher jni_abort_catcher;
diff --git a/test/JniTest/JniTest.java b/test/JniTest/JniTest.java
index 33418a9..daf0767 100644
--- a/test/JniTest/JniTest.java
+++ b/test/JniTest/JniTest.java
@@ -29,6 +29,7 @@
testShortMethod();
testBooleanMethod();
testCharMethod();
+ testIsAssignableFromOnPrimitiveTypes();
}
private static native void testFindClassOnAttachedNativeThread();
@@ -151,4 +152,19 @@
}
}
}
+
+ // http://b/16531674
+ private static void testIsAssignableFromOnPrimitiveTypes() {
+ if (!nativeIsAssignableFrom(int.class, Integer.TYPE)) {
+ System.out.println("IsAssignableFrom(int.class, Integer.TYPE) returned false, expected true");
+ throw new AssertionError();
+ }
+
+ if (!nativeIsAssignableFrom(Integer.TYPE, int.class)) {
+ System.out.println("IsAssignableFrom(Integer.TYPE, int.class) returned false, expected true");
+ throw new AssertionError();
+ }
+ }
+
+ native static boolean nativeIsAssignableFrom(Class<?> from, Class<?> to);
}
diff --git a/test/JniTest/jni_test.cc b/test/JniTest/jni_test.cc
index 36cad72..511d893 100644
--- a/test/JniTest/jni_test.cc
+++ b/test/JniTest/jni_test.cc
@@ -286,3 +286,8 @@
return char_returns[c1];
}
+
+extern "C" JNIEXPORT jboolean JNICALL Java_Main_nativeIsAssignableFrom(JNIEnv* env, jclass,
+ jclass from, jclass to) {
+ return env->IsAssignableFrom(from, to);
+}
