Move InMemoryDexClassLoader to be a subtype of BaseDexClassLoader

Also write a test that class transformation works with this type of
class loader.

Test: mma -j40 test-art-host

Change-Id: Ibc2214191e04876ff7bbea010be6ec03b6f41904
diff --git a/test/949-in-memory-transform/src/Main.java b/test/949-in-memory-transform/src/Main.java
new file mode 100644
index 0000000..2ffabf5
--- /dev/null
+++ b/test/949-in-memory-transform/src/Main.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.util.Base64;
+import java.lang.reflect.*;
+import java.nio.ByteBuffer;
+
+public class Main {
+  /**
+   * base64 encoded class/dex file for
+   * public class Transform {
+   *   public void sayHi() {
+   *    System.out.println("hello");
+   *   }
+   * }
+   */
+  private static final byte[] INITIAL_CLASS_BYTES = Base64.getDecoder().decode(
+    "yv66vgAAADQAHAoABgAOCQAPABAIABEKABIAEwcAFAcAFQEABjxpbml0PgEAAygpVgEABENvZGUB" +
+    "AA9MaW5lTnVtYmVyVGFibGUBAAVzYXlIaQEAClNvdXJjZUZpbGUBAA5UcmFuc2Zvcm0uamF2YQwA" +
+    "BwAIBwAWDAAXABgBAAVoZWxsbwcAGQwAGgAbAQAJVHJhbnNmb3JtAQAQamF2YS9sYW5nL09iamVj" +
+    "dAEAEGphdmEvbGFuZy9TeXN0ZW0BAANvdXQBABVMamF2YS9pby9QcmludFN0cmVhbTsBABNqYXZh" +
+    "L2lvL1ByaW50U3RyZWFtAQAHcHJpbnRsbgEAFShMamF2YS9sYW5nL1N0cmluZzspVgAhAAUABgAA" +
+    "AAAAAgABAAcACAABAAkAAAAdAAEAAQAAAAUqtwABsQAAAAEACgAAAAYAAQAAABEAAQALAAgAAQAJ" +
+    "AAAAJQACAAEAAAAJsgACEgO2AASxAAAAAQAKAAAACgACAAAAGgAIABsAAQAMAAAAAgAN");
+  private static final byte[] INITIAL_DEX_BYTES = Base64.getDecoder().decode(
+    "ZGV4CjAzNQAJX3mZphwHJCT1qdTz/GS+jXOR+O/9e3fMAgAAcAAAAHhWNBIAAAAAAAAAACwCAAAO" +
+    "AAAAcAAAAAYAAACoAAAAAgAAAMAAAAABAAAA2AAAAAQAAADgAAAAAQAAAAABAACsAQAAIAEAAGIB" +
+    "AABqAQAAdwEAAI4BAACiAQAAtgEAAMoBAADaAQAA3QEAAOEBAAD1AQAA/AEAAAECAAAKAgAAAQAA" +
+    "AAIAAAADAAAABAAAAAUAAAAHAAAABwAAAAUAAAAAAAAACAAAAAUAAABcAQAABAABAAsAAAAAAAAA" +
+    "AAAAAAAAAAANAAAAAQABAAwAAAACAAAAAAAAAAAAAAABAAAAAgAAAAAAAAAGAAAAAAAAABwCAAAA" +
+    "AAAAAQABAAEAAAARAgAABAAAAHAQAwAAAA4AAwABAAIAAAAWAgAACQAAAGIAAAAbAQoAAABuIAIA" +
+    "EAAOAAAAAQAAAAMABjxpbml0PgALTFRyYW5zZm9ybTsAFUxqYXZhL2lvL1ByaW50U3RyZWFtOwAS" +
+    "TGphdmEvbGFuZy9PYmplY3Q7ABJMamF2YS9sYW5nL1N0cmluZzsAEkxqYXZhL2xhbmcvU3lzdGVt" +
+    "OwAOVHJhbnNmb3JtLmphdmEAAVYAAlZMABJlbWl0dGVyOiBqYWNrLTQuMjUABWhlbGxvAANvdXQA" +
+    "B3ByaW50bG4ABXNheUhpABEABw4AGgAHDocAAAABAQCBgASgAgEBuAIAAA0AAAAAAAAAAQAAAAAA" +
+    "AAABAAAADgAAAHAAAAACAAAABgAAAKgAAAADAAAAAgAAAMAAAAAEAAAAAQAAANgAAAAFAAAABAAA" +
+    "AOAAAAAGAAAAAQAAAAABAAABIAAAAgAAACABAAABEAAAAQAAAFwBAAACIAAADgAAAGIBAAADIAAA" +
+    "AgAAABECAAAAIAAAAQAAABwCAAAAEAAAAQAAACwCAAA=");
+
+
+  /**
+   * base64 encoded class/dex file for
+   * public class Transform {
+   *   public void sayHi() {
+   *    System.out.println("Goodbye");
+   *   }
+   * }
+   */
+  private static final byte[] TRANSFORMED_CLASS_BYTES = Base64.getDecoder().decode(
+    "yv66vgAAADQAHAoABgAOCQAPABAIABEKABIAEwcAFAcAFQEABjxpbml0PgEAAygpVgEABENvZGUB" +
+    "AA9MaW5lTnVtYmVyVGFibGUBAAVzYXlIaQEAClNvdXJjZUZpbGUBAA5UcmFuc2Zvcm0uamF2YQwA" +
+    "BwAIBwAWDAAXABgBAAdHb29kYnllBwAZDAAaABsBAAlUcmFuc2Zvcm0BABBqYXZhL2xhbmcvT2Jq" +
+    "ZWN0AQAQamF2YS9sYW5nL1N5c3RlbQEAA291dAEAFUxqYXZhL2lvL1ByaW50U3RyZWFtOwEAE2ph" +
+    "dmEvaW8vUHJpbnRTdHJlYW0BAAdwcmludGxuAQAVKExqYXZhL2xhbmcvU3RyaW5nOylWACEABQAG" +
+    "AAAAAAACAAEABwAIAAEACQAAAB0AAQABAAAABSq3AAGxAAAAAQAKAAAABgABAAAAEQABAAsACAAB" +
+    "AAkAAAAlAAIAAQAAAAmyAAISA7YABLEAAAABAAoAAAAKAAIAAAAaAAgAGwABAAwAAAACAA0=");
+  private static final byte[] TRANSFORMED_DEX_BYTES = Base64.getDecoder().decode(
+    "ZGV4CjAzNQAPXh6T3l1FObhHsKf1U2vi+0GmAvElxBLMAgAAcAAAAHhWNBIAAAAAAAAAACwCAAAO" +
+    "AAAAcAAAAAYAAACoAAAAAgAAAMAAAAABAAAA2AAAAAQAAADgAAAAAQAAAAABAACsAQAAIAEAAGIB" +
+    "AABqAQAAcwEAAIABAACXAQAAqwEAAL8BAADTAQAA4wEAAOYBAADqAQAA/gEAAAMCAAAMAgAAAgAA" +
+    "AAMAAAAEAAAABQAAAAYAAAAIAAAACAAAAAUAAAAAAAAACQAAAAUAAABcAQAABAABAAsAAAAAAAAA" +
+    "AAAAAAAAAAANAAAAAQABAAwAAAACAAAAAAAAAAAAAAABAAAAAgAAAAAAAAAHAAAAAAAAAB4CAAAA" +
+    "AAAAAQABAAEAAAATAgAABAAAAHAQAwAAAA4AAwABAAIAAAAYAgAACQAAAGIAAAAbAQEAAABuIAIA" +
+    "EAAOAAAAAQAAAAMABjxpbml0PgAHR29vZGJ5ZQALTFRyYW5zZm9ybTsAFUxqYXZhL2lvL1ByaW50" +
+    "U3RyZWFtOwASTGphdmEvbGFuZy9PYmplY3Q7ABJMamF2YS9sYW5nL1N0cmluZzsAEkxqYXZhL2xh" +
+    "bmcvU3lzdGVtOwAOVHJhbnNmb3JtLmphdmEAAVYAAlZMABJlbWl0dGVyOiBqYWNrLTQuMjUAA291" +
+    "dAAHcHJpbnRsbgAFc2F5SGkAEQAHDgAaAAcOhwAAAAEBAIGABKACAQG4Ag0AAAAAAAAAAQAAAAAA" +
+    "AAABAAAADgAAAHAAAAACAAAABgAAAKgAAAADAAAAAgAAAMAAAAAEAAAAAQAAANgAAAAFAAAABAAA" +
+    "AOAAAAAGAAAAAQAAAAABAAABIAAAAgAAACABAAABEAAAAQAAAFwBAAACIAAADgAAAGIBAAADIAAA" +
+    "AgAAABMCAAAAIAAAAQAAAB4CAAAAEAAAAQAAACwCAAA=");
+
+  public static void main(String[] args) throws Exception {
+    ClassLoader loader;
+    try {
+      // Art uses this classloader to do in-memory dex files. There is no support for defineClass
+      loader = (ClassLoader)Class.forName("dalvik.system.InMemoryDexClassLoader")
+                                 .getConstructor(ByteBuffer.class, ClassLoader.class)
+                                 .newInstance(ByteBuffer.wrap(INITIAL_DEX_BYTES),
+                                              ClassLoader.getSystemClassLoader());
+    } catch (ClassNotFoundException e) {
+      // Seem to be on RI. Just make a new ClassLoader that calls defineClass.
+      loader = new ClassLoader() {
+        public Class<?> findClass(String name) throws ClassNotFoundException {
+          if (name.equals("Transform")) {
+            return defineClass(name, INITIAL_CLASS_BYTES, 0, INITIAL_CLASS_BYTES.length);
+          } else {
+            throw new ClassNotFoundException("Couldn't find class: " + name);
+          }
+        }
+      };
+    }
+    doTest(loader);
+  }
+
+  public static void doTest(ClassLoader loader) throws Exception {
+    // Get the class
+    Class<?> transform_class = loader.loadClass("Transform");
+    Method say_hi_method = transform_class.getMethod("sayHi");
+    Object t = transform_class.newInstance();
+
+    // Run the actual test.
+    say_hi_method.invoke(t);
+    doCommonClassRedefinition(transform_class, TRANSFORMED_CLASS_BYTES, TRANSFORMED_DEX_BYTES);
+    say_hi_method.invoke(t);
+  }
+
+  // Transforms the class
+  private static native void doCommonClassRedefinition(Class<?> target,
+                                                       byte[] class_file,
+                                                       byte[] dex_file);
+}