| /* |
| * Copyright (C) 2011 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. |
| */ |
| |
| package dalvik.system; |
| |
| import dalvik.annotation.compat.UnsupportedAppUsage; |
| import java.io.File; |
| import java.io.IOException; |
| import java.net.URL; |
| import java.nio.ByteBuffer; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Enumeration; |
| import java.util.List; |
| import sun.misc.CompoundEnumeration; |
| |
| /** |
| * Base class for common functionality between various dex-based |
| * {@link ClassLoader} implementations. |
| */ |
| public class BaseDexClassLoader extends ClassLoader { |
| |
| /** |
| * Hook for customizing how dex files loads are reported. |
| * |
| * This enables the framework to monitor the use of dex files. The |
| * goal is to simplify the mechanism for optimizing foreign dex files and |
| * enable further optimizations of secondary dex files. |
| * |
| * The reporting happens only when new instances of BaseDexClassLoader |
| * are constructed and will be active only after this field is set with |
| * {@link BaseDexClassLoader#setReporter}. |
| */ |
| /* @NonNull */ private static volatile Reporter reporter = null; |
| |
| @UnsupportedAppUsage |
| private final DexPathList pathList; |
| |
| /** |
| * Array of ClassLoaders that can be used to load classes and resources that the code in |
| * {@code pathList} may depend on. This is used to implement Android's |
| * <a href=https://developer.android.com/guide/topics/manifest/uses-library-element> |
| * shared libraries</a> feature. |
| * <p>The shared library loaders are always checked before the {@code pathList} when looking |
| * up classes and resources. |
| * |
| * <p>{@code null} if the class loader has no shared library. |
| * |
| * @hide |
| */ |
| protected final ClassLoader[] sharedLibraryLoaders; |
| |
| /** |
| * Constructs an instance. |
| * Note that all the *.jar and *.apk files from {@code dexPath} might be |
| * first extracted in-memory before the code is loaded. This can be avoided |
| * by passing raw dex files (*.dex) in the {@code dexPath}. |
| * |
| * @param dexPath the list of jar/apk files containing classes and |
| * resources, delimited by {@code File.pathSeparator}, which |
| * defaults to {@code ":"} on Android. |
| * @param optimizedDirectory this parameter is deprecated and has no effect since API level 26. |
| * @param librarySearchPath the list of directories containing native |
| * libraries, delimited by {@code File.pathSeparator}; may be |
| * {@code null} |
| * @param parent the parent class loader |
| */ |
| public BaseDexClassLoader(String dexPath, File optimizedDirectory, |
| String librarySearchPath, ClassLoader parent) { |
| this(dexPath, librarySearchPath, parent, null, false); |
| } |
| |
| /** |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| public BaseDexClassLoader(String dexPath, File optimizedDirectory, |
| String librarySearchPath, ClassLoader parent, boolean isTrusted) { |
| this(dexPath, librarySearchPath, parent, null, isTrusted); |
| } |
| |
| /** |
| * @hide |
| */ |
| public BaseDexClassLoader(String dexPath, |
| String librarySearchPath, ClassLoader parent, ClassLoader[] libraries) { |
| this(dexPath, librarySearchPath, parent, libraries, false); |
| } |
| |
| /** |
| * BaseDexClassLoader implements the Android |
| * <a href=https://developer.android.com/guide/topics/manifest/uses-library-element> |
| * shared libraries</a> feature by changing the typical parent delegation mechanism |
| * of class loaders. |
| * <p> Each shared library is associated with its own class loader, which is added to a list of |
| * class loaders this BaseDexClassLoader tries to load from in order, immediately checking |
| * after the parent. |
| * The shared library loaders are always checked before the {@code pathList} when looking |
| * up classes and resources. |
| * |
| * @hide |
| */ |
| public BaseDexClassLoader(String dexPath, |
| String librarySearchPath, ClassLoader parent, ClassLoader[] sharedLibraryLoaders, |
| boolean isTrusted) { |
| super(parent); |
| // Setup shared libraries before creating the path list. ART relies on the class loader |
| // hierarchy being finalized before loading dex files. |
| this.sharedLibraryLoaders = sharedLibraryLoaders == null |
| ? null |
| : Arrays.copyOf(sharedLibraryLoaders, sharedLibraryLoaders.length); |
| this.pathList = new DexPathList(this, dexPath, librarySearchPath, null, isTrusted); |
| |
| if (reporter != null) { |
| reportClassLoaderChain(); |
| } |
| } |
| |
| /** |
| * Reports the current class loader chain to the registered {@code reporter}. |
| */ |
| private void reportClassLoaderChain() { |
| ArrayList<ClassLoader> classLoadersChain = new ArrayList<>(); |
| ArrayList<String> classPaths = new ArrayList<>(); |
| |
| classLoadersChain.add(this); |
| classPaths.add(String.join(File.pathSeparator, pathList.getDexPaths())); |
| |
| ClassLoader bootClassLoader = ClassLoader.getSystemClassLoader().getParent(); |
| ClassLoader current = getParent(); |
| |
| while (current != null && current != bootClassLoader) { |
| classLoadersChain.add(current); |
| if (current instanceof BaseDexClassLoader) { |
| BaseDexClassLoader bdcCurrent = (BaseDexClassLoader) current; |
| classPaths.add(String.join(File.pathSeparator, bdcCurrent.pathList.getDexPaths())); |
| } else { |
| // We can't determine the classpath for arbitrary class loaders. |
| classPaths.add(null); |
| } |
| current = current.getParent(); |
| } |
| |
| reporter.report(classLoadersChain, classPaths); |
| } |
| |
| /** |
| * Constructs an instance. |
| * |
| * dexFile must be an in-memory representation of a full dexFile. |
| * |
| * @param dexFiles the array of in-memory dex files containing classes. |
| * @param librarySearchPath the list of directories containing native |
| * libraries, delimited by {@code File.pathSeparator}; may be {@code null} |
| * @param parent the parent class loader |
| * |
| * @hide |
| */ |
| public BaseDexClassLoader(ByteBuffer[] dexFiles, String librarySearchPath, ClassLoader parent) { |
| super(parent); |
| this.sharedLibraryLoaders = null; |
| this.pathList = new DexPathList(this, librarySearchPath); |
| this.pathList.initByteBufferDexPath(dexFiles); |
| } |
| |
| @Override |
| protected Class<?> findClass(String name) throws ClassNotFoundException { |
| // First, check whether the class is present in our shared libraries. |
| if (sharedLibraryLoaders != null) { |
| for (ClassLoader loader : sharedLibraryLoaders) { |
| try { |
| return loader.loadClass(name); |
| } catch (ClassNotFoundException ignored) { |
| } |
| } |
| } |
| // Check whether the class in question is present in the dexPath that |
| // this classloader operates on. |
| List<Throwable> suppressedExceptions = new ArrayList<Throwable>(); |
| Class c = pathList.findClass(name, suppressedExceptions); |
| if (c == null) { |
| ClassNotFoundException cnfe = new ClassNotFoundException( |
| "Didn't find class \"" + name + "\" on path: " + pathList); |
| for (Throwable t : suppressedExceptions) { |
| cnfe.addSuppressed(t); |
| } |
| throw cnfe; |
| } |
| return c; |
| } |
| |
| /** |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| @libcore.api.CorePlatformApi |
| public void addDexPath(String dexPath) { |
| addDexPath(dexPath, false /*isTrusted*/); |
| } |
| |
| /** |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| public void addDexPath(String dexPath, boolean isTrusted) { |
| pathList.addDexPath(dexPath, null /*optimizedDirectory*/, isTrusted); |
| } |
| |
| /** |
| * Adds additional native paths for consideration in subsequent calls to |
| * {@link #findLibrary(String)} |
| * @hide |
| */ |
| @libcore.api.CorePlatformApi |
| public void addNativePath(Collection<String> libPaths) { |
| pathList.addNativePath(libPaths); |
| } |
| |
| @Override |
| protected URL findResource(String name) { |
| if (sharedLibraryLoaders != null) { |
| for (ClassLoader loader : sharedLibraryLoaders) { |
| URL url = loader.getResource(name); |
| if (url != null) { |
| return url; |
| } |
| } |
| } |
| return pathList.findResource(name); |
| } |
| |
| @Override |
| protected Enumeration<URL> findResources(String name) { |
| Enumeration<URL> myResources = pathList.findResources(name); |
| if (sharedLibraryLoaders == null) { |
| return myResources; |
| } |
| |
| Enumeration<URL>[] tmp = |
| (Enumeration<URL>[]) new Enumeration<?>[sharedLibraryLoaders.length + 1]; |
| // This will add duplicate resources if a shared library is loaded twice, but that's ok |
| // as we don't guarantee uniqueness. |
| for (int i = 0; i < sharedLibraryLoaders.length; i++) { |
| try { |
| tmp[i] = sharedLibraryLoaders[i].getResources(name); |
| } catch (IOException e) { |
| // Ignore. |
| } |
| } |
| tmp[sharedLibraryLoaders.length] = myResources; |
| return new CompoundEnumeration<>(tmp); |
| } |
| |
| @Override |
| public String findLibrary(String name) { |
| return pathList.findLibrary(name); |
| } |
| |
| /** |
| * Returns package information for the given package. |
| * Unfortunately, instances of this class don't really have this |
| * information, and as a non-secure {@code ClassLoader}, it isn't |
| * even required to, according to the spec. Yet, we want to |
| * provide it, in order to make all those hopeful callers of |
| * {@code myClass.getPackage().getName()} happy. Thus we construct |
| * a {@code Package} object the first time it is being requested |
| * and fill most of the fields with dummy values. The {@code |
| * Package} object is then put into the {@code ClassLoader}'s |
| * package cache, so we see the same one next time. We don't |
| * create {@code Package} objects for {@code null} arguments or |
| * for the default package. |
| * |
| * <p>There is a limited chance that we end up with multiple |
| * {@code Package} objects representing the same package: It can |
| * happen when when a package is scattered across different JAR |
| * files which were loaded by different {@code ClassLoader} |
| * instances. This is rather unlikely, and given that this whole |
| * thing is more or less a workaround, probably not worth the |
| * effort to address. |
| * |
| * @param name the name of the class |
| * @return the package information for the class, or {@code null} |
| * if there is no package information available for it |
| */ |
| @Override |
| protected synchronized Package getPackage(String name) { |
| if (name != null && !name.isEmpty()) { |
| Package pack = super.getPackage(name); |
| |
| if (pack == null) { |
| pack = definePackage(name, "Unknown", "0.0", "Unknown", |
| "Unknown", "0.0", "Unknown", null); |
| } |
| |
| return pack; |
| } |
| |
| return null; |
| } |
| |
| /** |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| @libcore.api.CorePlatformApi |
| public String getLdLibraryPath() { |
| StringBuilder result = new StringBuilder(); |
| for (File directory : pathList.getNativeLibraryDirectories()) { |
| if (result.length() > 0) { |
| result.append(':'); |
| } |
| result.append(directory); |
| } |
| |
| return result.toString(); |
| } |
| |
| @Override public String toString() { |
| return getClass().getName() + "[" + pathList + "]"; |
| } |
| |
| /** |
| * Sets the reporter for dex load notifications. |
| * Once set, all new instances of BaseDexClassLoader will report upon |
| * constructions the loaded dex files. |
| * |
| * @param newReporter the new Reporter. Setting null will cancel reporting. |
| * @hide |
| */ |
| @libcore.api.CorePlatformApi |
| public static void setReporter(Reporter newReporter) { |
| reporter = newReporter; |
| } |
| |
| /** |
| * @hide |
| */ |
| public static Reporter getReporter() { |
| return reporter; |
| } |
| |
| /** |
| * @hide |
| */ |
| @libcore.api.CorePlatformApi |
| public interface Reporter { |
| /** |
| * Reports the construction of a BaseDexClassLoader and provides information about the |
| * class loader chain. |
| * |
| * @param classLoadersChain the chain of class loaders used during the construction of the |
| * class loader. The first element is the BaseDexClassLoader being constructed, |
| * the second element is its parent, and so on. |
| * @param classPaths the class paths of the class loaders present in |
| * {@param classLoadersChain}. The first element corresponds to the first class |
| * loader and so on. A classpath is represented as a list of dex files separated by |
| * {@code File.pathSeparator}. If the class loader is not a BaseDexClassLoader the |
| * classpath will be null. |
| */ |
| @libcore.api.CorePlatformApi |
| void report(List<ClassLoader> classLoadersChain, List<String> classPaths); |
| } |
| } |