content: /*
   * 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 LoadedByMyClassLoader {
    public static void bar() {
      Level1.$inline$bar();
    }
  }
  
  class Main {
    public static void main(String[] args) throws Exception {
      System.loadLibrary(args[0]);
      // 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);
  }
  