/*
* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package org.graalvm.compiler.core.common.util;
import static org.graalvm.compiler.core.common.util.Util.JAVA_SPECIFICATION_VERSION;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
/**
* Reflection based access to the Module API introduced by JDK 9. This allows the API to be used in
* code that must be compiled on a JDK prior to 9. Use of this class must be guarded by a test for
* JDK 9 or later. For example:
*
* <pre>
* if (Util.JAVA_SPECIFICATION_VERSION >= 9) {
* // Use of ModuleAPI
* }
* </pre>
*/
public final class ModuleAPI {
private ModuleAPI(Method method) {
this.method = method;
}
private final Method method;
/**
* {@code Class.getModule()}.
*/
public static final ModuleAPI getModule;
/**
* {@code jdk.internal.module.Modules.addExports(Module, String, Module)}.
*/
public static final ModuleAPI addExports;
/**
* {@code jdk.internal.module.Modules.addOpens(Module, String, Module)}.
*/
public static final ModuleAPI addOpens;
/**
* {@code java.lang.reflect.Module.getResourceAsStream(String)}.
*/
public static final ModuleAPI getResourceAsStream;
/**
* {@code java.lang.reflect.Module.getPackages()}.
*/
public static final ModuleAPI getPackages;
/**
* {@code java.lang.reflect.Module.canRead(Module)}.
*/
public static final ModuleAPI canRead;
/**
* {@code java.lang.reflect.Module.isExported(String)}.
*/
public static final ModuleAPI isExported;
/**
* {@code java.lang.reflect.Module.isExported(String, Module)}.
*/
public static final ModuleAPI isExportedTo;
/**
* Invokes the static Module API method represented by this object.
*/
@SuppressWarnings("unchecked")
public <T> T invokeStatic(Object... args) {
checkAvailability();
assert Modifier.isStatic(method.getModifiers());
try {
return (T) method.invoke(null, args);
} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
throw new InternalError(e);
}
}
/**
* Invokes the non-static Module API method represented by this object.
*/
@SuppressWarnings("unchecked")
public <T> T invoke(Object receiver, Object... args) {
checkAvailability();
assert !Modifier.isStatic(method.getModifiers());
try {
return (T) method.invoke(receiver, args);
} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
throw new InternalError(e);
}
}
/**
* Opens all packages in {@code moduleMember}'s module for deep reflection (i.e., allow
* {@link AccessibleObject#setAccessible(boolean)} to be called for any class/method/field) by
* {@code requestor}'s module.
*/
public static void openAllPackagesForReflectionTo(Class<?> moduleMember, Class<?> requestor) {
Object moduleToOpen = getModule.invoke(moduleMember);
Object requestorModule = getModule.invoke(requestor);
if (moduleToOpen != requestorModule) {
String[] packages = getPackages.invoke(moduleToOpen);
for (String pkg : packages) {
addOpens.invokeStatic(moduleToOpen, pkg, requestorModule);
}
}
}
/**
* Opens {@code declaringClass}'s package to allow a method declared in {@code accessor} to call
* {@link AccessibleObject#setAccessible(boolean)} on an {@link AccessibleObject} representing a
* field or method declared by {@code declaringClass}.
*/
public static void openForReflectionTo(Class<?> declaringClass, Class<?> accessor) {
Object moduleToOpen = getModule.invoke(declaringClass);
Object accessorModule = getModule.invoke(accessor);
if (moduleToOpen != accessorModule) {
addOpens.invokeStatic(moduleToOpen, declaringClass.getPackage().getName(), accessorModule);
}
}
/**
* Exports the package named {@code packageName} declared in {@code moduleMember}'s module to
* {@code requestor}'s module.
*/
public static void exportPackageTo(Class<?> moduleMember, String packageName, Class<?> requestor) {
Object moduleToExport = getModule.invoke(moduleMember);
Object requestorModule = getModule.invoke(requestor);
if (moduleToExport != requestorModule) {
addExports.invokeStatic(moduleToExport, packageName, requestorModule);
}
}
private void checkAvailability() throws InternalError {
if (method == null) {
throw new InternalError("Cannot use Module API on JDK " + JAVA_SPECIFICATION_VERSION);
}
}
static {
if (JAVA_SPECIFICATION_VERSION >= 9) {
try {
getModule = new ModuleAPI(Class.class.getMethod("getModule"));
Class<?> moduleClass = getModule.method.getReturnType();
Class<?> modulesClass = Class.forName("jdk.internal.module.Modules");
getResourceAsStream = new ModuleAPI(moduleClass.getMethod("getResourceAsStream", String.class));
getPackages = new ModuleAPI(moduleClass.getMethod("getPackages"));
canRead = new ModuleAPI(moduleClass.getMethod("canRead", moduleClass));
isExported = new ModuleAPI(moduleClass.getMethod("isExported", String.class));
isExportedTo = new ModuleAPI(moduleClass.getMethod("isExported", String.class, moduleClass));
addExports = new ModuleAPI(modulesClass.getDeclaredMethod("addExports", moduleClass, String.class, moduleClass));
addOpens = new ModuleAPI(modulesClass.getDeclaredMethod("addOpens", moduleClass, String.class, moduleClass));
} catch (NoSuchMethodException | SecurityException | ClassNotFoundException e) {
throw new InternalError(e);
}
} else {
ModuleAPI unavailable = new ModuleAPI(null);
getModule = unavailable;
getResourceAsStream = unavailable;
getPackages = unavailable;
canRead = unavailable;
isExported = unavailable;
isExportedTo = unavailable;
addExports = unavailable;
addOpens = unavailable;
}
}
}