Use the caller's class loader when walking inlined frames.

We should not use the outer most class loader. JLS specification
is to use the caller's class loader.

Change-Id: I736f36c9b6a44fab213ad0c01cf1efc975b9b3a6
diff --git a/test/497-inlining-and-class-loader/src/Main.java b/test/497-inlining-and-class-loader/src/Main.java
new file mode 100644
index 0000000..bb8da6d
--- /dev/null
+++ b/test/497-inlining-and-class-loader/src/Main.java
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2015 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.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.List;
+
+class MyClassLoader extends ClassLoader {
+  MyClassLoader() throws Exception {
+    super(MyClassLoader.class.getClassLoader());
+
+    // Some magic to get access to the pathList field of BaseDexClassLoader.
+    ClassLoader loader = getClass().getClassLoader();
+    Class<?> baseDexClassLoader = loader.getClass().getSuperclass();
+    Field f = baseDexClassLoader.getDeclaredField("pathList");
+    f.setAccessible(true);
+    Object pathList = f.get(loader);
+
+    // Some magic to get access to the dexField field of pathList.
+    f = pathList.getClass().getDeclaredField("dexElements");
+    f.setAccessible(true);
+    dexElements = (Object[]) f.get(pathList);
+    dexFileField = dexElements[0].getClass().getDeclaredField("dexFile");
+    dexFileField.setAccessible(true);
+  }
+
+  Object[] dexElements;
+  Field dexFileField;
+
+  static ClassLoader level1ClassLoader;
+
+  protected Class<?> loadClass(String className, boolean resolve) throws ClassNotFoundException {
+    if (this != level1ClassLoader) {
+      if (className.equals("Level1")) {
+        return level1ClassLoader.loadClass(className);
+      } else if (className.equals("Level2")) {
+        throw new ClassNotFoundException("None of my methods require Level2!");
+      } else if (!className.equals("LoadedByMyClassLoader")) {
+        // We're only going to handle LoadedByMyClassLoader.
+        return getParent().loadClass(className);
+      }
+    } else {
+      if (className != "Level1" && className != "Level2") {
+        return getParent().loadClass(className);
+      }
+    }
+
+    // Mimic what DexPathList.findClass is doing.
+    try {
+      for (Object element : dexElements) {
+        Object dex = dexFileField.get(element);
+        Method method = dex.getClass().getDeclaredMethod(
+            "loadClassBinaryName", String.class, ClassLoader.class, List.class);
+
+        if (dex != null) {
+          Class clazz = (Class)method.invoke(dex, className, this, null);
+          if (clazz != null) {
+            return clazz;
+          }
+        }
+      }
+    } catch (Exception e) { /* Ignore */ }
+    return null;
+  }
+}
+
+class Level1 {
+  public static void $inline$bar() {
+    Level2.$inline$bar();
+  }
+}
+
+class Level2 {
+  public static void $inline$bar() {
+    Main.$noinline$bar();
+  }
+}
+
+class LoadedByMyClassLoader {
+  public static void bar() {
+    Level1.$inline$bar();
+  }
+}
+
+class Main {
+  static {
+    System.loadLibrary("arttest");
+  }
+
+  public static void main(String[] args) throws Exception {
+    // Clone resolved methods, to restore the original version just
+    // before we walk the stack in $noinline$bar.
+    savedResolvedMethods = cloneResolvedMethods(Main.class);
+
+    MyClassLoader o = new MyClassLoader();
+    MyClassLoader.level1ClassLoader = new MyClassLoader();
+    Class foo = o.loadClass("LoadedByMyClassLoader");
+    Method m = foo.getDeclaredMethod("bar");
+    try {
+      m.invoke(null);
+    } catch (Error e) { /* Ignore */ }
+  }
+
+  public static void $inline$bar() {
+  }
+
+  public static void $noinline$bar() {
+    try {
+      // Be evil and clear all dex cache entries.
+      Field f = Class.class.getDeclaredField("dexCache");
+      f.setAccessible(true);
+      Object dexCache = f.get(Main.class);
+      f = dexCache.getClass().getDeclaredField("resolvedTypes");
+      f.setAccessible(true);
+      Object[] array = (Object[]) f.get(dexCache);
+      for (int i = 0; i < array.length; i++) {
+        array[i] = null;
+      }
+      restoreResolvedMethods(Main.class, savedResolvedMethods);
+    } catch (Throwable t) { /* Ignore */ }
+
+    // This will walk the stack, trying to resolve methods in it.
+    // Because we cleared dex cache entries, we will have to find
+    // classes again, which require to use the correct class loader
+    // in the presence of inlining.
+    new Exception().printStackTrace();
+  }
+  static Object savedResolvedMethods;
+
+  static native Object cloneResolvedMethods(Class<?> cls);
+  static native void restoreResolvedMethods(Class<?> cls, Object saved);
+}