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/*
* 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.ArrayList;
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.
// Need to make a copy of the dex elements since we don't want an app image with pre-resolved
// things.
f = pathList.getClass().getDeclaredField("dexElements");
f.setAccessible(true);
Object[] dexElements = (Object[]) f.get(pathList);
f = dexElements[0].getClass().getDeclaredField("dexFile");
f.setAccessible(true);
for (Object element : dexElements) {
Object dexFile = f.get(element);
// Make copy.
Field fileNameField = dexFile.getClass().getDeclaredField("mFileName");
fileNameField.setAccessible(true);
dexFiles.add(dexFile.getClass().getDeclaredConstructor(String.class).newInstance(
fileNameField.get(dexFile)));
}
}
ArrayList<Object> dexFiles = new ArrayList<Object>();
Field dexFileField;
protected Class<?> loadClass(String className, boolean resolve) throws ClassNotFoundException {
// Other classes may also get loaded, ignore those.
if (className.equals("LoadedByMyClassLoader") || className.equals("FirstSeenByMyClassLoader")) {
System.out.println("Request for " + className);
}
// We're only going to handle LoadedByMyClassLoader.
if (className != "LoadedByMyClassLoader") {
return getParent().loadClass(className);
}
// Mimic what DexPathList.findClass is doing.
try {
for (Object dexFile : dexFiles) {
Method method = dexFile.getClass().getDeclaredMethod(
"loadClassBinaryName", String.class, ClassLoader.class, List.class);
if (dexFile != null) {
Class<?> clazz = (Class<?>)method.invoke(dexFile, className, this, null);
if (clazz != null) {
return clazz;
}
}
}
} catch (Exception e) { /* Ignore */ }
return null;
}
}
class LoadedByMyClassLoader {
/// CHECK-START: void LoadedByMyClassLoader.bar() inliner (before)
/// CHECK: LoadClass class_name:FirstSeenByMyClassLoader
/// CHECK-NEXT: ClinitCheck
/// CHECK-NEXT: InvokeStaticOrDirect
/// CHECK-NEXT: LoadClass class_name:java.lang.System
/// CHECK-NEXT: ClinitCheck
/// CHECK-NEXT: StaticFieldGet
/// CHECK-NEXT: LoadString
/// CHECK-NEXT: NullCheck
/// CHECK-NEXT: InvokeVirtual
/// CHECK-START: void LoadedByMyClassLoader.bar() inliner (after)
/// CHECK: LoadClass class_name:FirstSeenByMyClassLoader
/// CHECK-NEXT: ClinitCheck
/* We inlined FirstSeenByMyClassLoader.$inline$bar */
/// CHECK-NEXT: LoadClass class_name:java.lang.System
/// CHECK-NEXT: ClinitCheck
/// CHECK-NEXT: StaticFieldGet
/// CHECK-NEXT: LoadString
/// CHECK-NEXT: NullCheck
/// CHECK-NEXT: InvokeVirtual
/// CHECK-START: void LoadedByMyClassLoader.bar() register (before)
/* Load and initialize FirstSeenByMyClassLoader */
/// CHECK: LoadClass class_name:FirstSeenByMyClassLoader gen_clinit_check:true
/* Load and initialize System */
// There may be HX86ComputeBaseMethodAddress here.
/// CHECK: LoadClass class_name:java.lang.System
// The ClinitCheck may (PIC) or may not (non-PIC) be merged into the LoadClass.
// (The merging checks for environment match but HLoadClass/kBootImageAddress
// used for non-PIC mode does not have an environment at all.)
/// CHECK: StaticFieldGet
// There may be HX86ComputeBaseMethodAddress here.
/// CHECK: LoadString
/// CHECK-NEXT: NullCheck
/// CHECK-NEXT: InvokeVirtual
public static void bar() {
FirstSeenByMyClassLoader.$inline$bar();
System.out.println("In between the two calls.");
FirstSeenByMyClassLoader.$noinline$bar();
}
}
public class Main {
public static void main(String[] args) throws Exception {
MyClassLoader o = new MyClassLoader();
Class<?> foo = o.loadClass("LoadedByMyClassLoader");
Method m = foo.getDeclaredMethod("bar");
m.invoke(null);
}
}
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