Remove the native Class.isInstance, and add tests.

Change-Id: I5e669b71e11a6b794e3434e0406d891edd3fe59d

2 files changed, 75 insertions, 10 deletions

diff --git a/src/java_lang_Class.cc b/src/java_lang_Class.cc
index d16524b09e..20af47a594 100644
--- a/src/java_lang_Class.cc
+++ b/src/java_lang_Class.cc
@@ -365,15 +365,6 @@ static jboolean Class_isAssignableFrom(JNIEnv* env, jobject javaLhs, jclass java
   return lhs->IsAssignableFrom(rhs) ? JNI_TRUE : JNI_FALSE;
 }
 
-static jboolean Class_isInstance(JNIEnv* env, jobject javaClass, jobject javaObject) {
-  Class* c = DecodeClass(env, javaClass);
-  Object* o = Decode<Object*>(env, javaObject);
-  if (o == NULL) {
-    return JNI_FALSE;
-  }
-  return o->InstanceOf(c) ? JNI_TRUE : JNI_FALSE;
-}
-
 // Validate method/field access.
 static bool CheckMemberAccess(const Class* access_from, Class* access_to, uint32_t member_flags) {
   // quick accept for public access */
@@ -478,7 +469,6 @@ static JNINativeMethod gMethods[] = {
   NATIVE_METHOD(Class, getNameNative, "()Ljava/lang/String;"),
   NATIVE_METHOD(Class, getProxyInterfaces, "()[Ljava/lang/Class;"),
   NATIVE_METHOD(Class, isAssignableFrom, "(Ljava/lang/Class;)Z"),
-  NATIVE_METHOD(Class, isInstance, "(Ljava/lang/Object;)Z"),
   NATIVE_METHOD(Class, newInstanceImpl, "()Ljava/lang/Object;"),
 };
 
diff --git a/test/031-class-attributes/src/ClassAttrs.java b/test/031-class-attributes/src/ClassAttrs.java
index c3c61bfaed..8719e3bd06 100644
--- a/test/031-class-attributes/src/ClassAttrs.java
+++ b/test/031-class-attributes/src/ClassAttrs.java
@@ -70,6 +70,81 @@ public class ClassAttrs {
             System.err.println("FAILED: " + re);
             re.printStackTrace();
         }
+
+        test_isAssignableFrom();
+        test_isInstance();
+    }
+
+    private static void test_isAssignableFrom() {
+        // Can always assign to things of the same type.
+        assertTrue(String.class.isAssignableFrom(String.class));
+
+        // Can assign any reference to java.lang.Object.
+        assertTrue(Object.class.isAssignableFrom(Object.class));
+        assertTrue(Object.class.isAssignableFrom(Class.class));
+        assertTrue(Object.class.isAssignableFrom(String.class));
+        assertFalse(Object.class.isAssignableFrom(int.class));
+        assertFalse(Object.class.isAssignableFrom(long.class));
+
+        // Interfaces.
+        assertTrue(CharSequence.class.isAssignableFrom(String.class));
+        assertFalse(CharSequence.class.isAssignableFrom(Object.class));
+
+        // Superclasses.
+        assertTrue(AccessibleObject.class.isAssignableFrom(Method.class));
+        assertFalse(Method.class.isAssignableFrom(AccessibleObject.class));
+
+        // Arrays.
+        assertTrue(int[].class.isAssignableFrom(int[].class));
+        assertFalse(int[].class.isAssignableFrom(char[].class));
+        assertFalse(char[].class.isAssignableFrom(int[].class));
+        assertTrue(Object.class.isAssignableFrom(int[].class));
+        assertFalse(int[].class.isAssignableFrom(Object.class));
+
+        try {
+            assertFalse(Object.class.isAssignableFrom(null));
+            fail();
+        } catch (NullPointerException expected) {
+        }
+    }
+
+    private static void test_isInstance() {
+        // Can always assign to things of the same type.
+        assertTrue(String.class.isInstance("hello"));
+
+        // Can assign any reference to java.lang.Object.
+        assertTrue(Object.class.isInstance(new Object()));
+        assertTrue(Object.class.isInstance(Class.class));
+        assertTrue(Object.class.isInstance("hello"));
+
+        // Interfaces.
+        assertTrue(CharSequence.class.isInstance("hello"));
+        assertFalse(CharSequence.class.isInstance(new Object()));
+
+        // Superclasses.
+        assertTrue(AccessibleObject.class.isInstance(Method.class.getDeclaredMethods()[0]));
+        assertFalse(Method.class.isInstance(Method.class.getDeclaredFields()[0]));
+
+        // Arrays.
+        assertTrue(int[].class.isInstance(new int[0]));
+        assertFalse(int[].class.isInstance(new char[0]));
+        assertFalse(char[].class.isInstance(new int[0]));
+        assertTrue(Object.class.isInstance(new int[0]));
+        assertFalse(int[].class.isInstance(new Object()));
+
+        assertFalse(Object.class.isInstance(null));
+    }
+
+    private static void assertTrue(boolean b) {
+        if (!b) throw new RuntimeException();
+    }
+
+    private static void assertFalse(boolean b) {
+        if (b) throw new RuntimeException();
+    }
+
+    private static void fail() {
+        throw new RuntimeException();
     }
 
     /* to call the (out-of-scope) <code>getSignatureAttribute</code> methods */