Clean up JNI loading code to support more JNI methods (ded39b61) · Commits · e / os / android_frameworks_base

tools/hoststubgen/hoststubgen/helper-framework-runtime-src/framework/com/android/hoststubgen/runtimehelper/ClassLoadHook.java

+30 −22

Original line number	Diff line number	Diff line
		@@ -21,15 +21,15 @@ import java.io.File;
		import java.io.PrintStream;
		import java.lang.reflect.Modifier;
		import java.util.ArrayList;
		import java.util.Arrays;

		/**
		* Standard class to handle class load hook.
		* Standard class loader hook.
		*
		* We use this to initialize the environment necessary for some classes. (e.g. load native libs.)
		* Currently, we use this class to load libandroid_runtime (if needed). In the future, we may
		* load other JNI or do other set up here.
		*/
		public class ClassLoadHook {
		private static PrintStream out = System.out;
		private static PrintStream sOut = System.out;

		/**
		* If true, we won't load `libandroid_runtime`
		@@ -59,19 +59,18 @@ public class ClassLoadHook {

		/**
		* Called when classes with
		* {@code @HostSideTestClassLoadHook("com.android.hoststubgen.runtimehelper.ClassLoadHook.onClassLoaded") }
		* {@code @HostSideTestClassLoadHook(
		* "com.android.hoststubgen.runtimehelper.LibandroidLoadingHook.onClassLoaded") }
		* are loaded.
		*/
		public static void onClassLoaded(Class<?> clazz) {
		System.out.println("Framework class loaded: " + clazz.getCanonicalName());

		if (android.util.Log.class == clazz) {
		loadFrameworkNativeCode();
		}
		}

		private static void log(String message) {
		out.println("ClassLoadHook: " + message);
		sOut.println("ClassLoadHook: " + message);
		}

		private static void log(String fmt, Object... args) {
		@@ -147,20 +146,27 @@ public class ClassLoadHook {
		loadJniLibrary(LIBANDROID_RUNTIME_NAME);
		}

		/**
		* Classes with native methods that are backed by `libandroid_runtime`.
		*
		* At runtime, we check if these classes have any methods, and if so, we'll have
		* `libandroid_runtime` register the native functions.
		*/
		private static final Class<?>[] sClassesWithLibandroidNativeMethods = {
		android.util.Log.class,
		android.os.Parcel.class,
		};

		/**
		* @return if a given method is a native method or not.
		*/
		private static boolean isNativeMethod(Class<?> clazz, String methodName, Class<?>... argTypes) {
		try {
		final var method = clazz.getMethod(methodName, argTypes);
		return Modifier.isNative(method.getModifiers());
		} catch (NoSuchMethodException e) {
		throw new HostTestException(String.format(
		"Class %s doesn't have method %s with args %s",
		clazz.getCanonicalName(),
		methodName,
		Arrays.toString(argTypes)), e);
		private static boolean hasNativeMethod(Class<?> clazz) {
		for (var method : clazz.getDeclaredMethods()) {
		if (Modifier.isNative(method.getModifiers())) {
		return true;
		}
		}
		return false;
		}

		/**
		@@ -172,9 +178,11 @@ public class ClassLoadHook {
		private static String getCoreNativeClassesToUse() {
		final var coreNativeClassesToLoad = new ArrayList<String>();

		if (isNativeMethod(android.util.Log.class, "isLoggable",
		String.class, int.class)) {
		coreNativeClassesToLoad.add("android.util.Log");
		for (var clazz : sClassesWithLibandroidNativeMethods) {
		if (hasNativeMethod(clazz)) {
		log("Class %s has native methods", clazz);
		coreNativeClassesToLoad.add(clazz.getName());
		}
		}

		return String.join(",", coreNativeClassesToLoad);