Agent can inject class into Java 9+ bootstrap class loader (#829)

5 files changed, 261 insertions, 1 deletions

diff --git a/jacoco/pom.xml b/jacoco/pom.xml
index 1128f3f2..581875b5 100644
--- a/jacoco/pom.xml
+++ b/jacoco/pom.xml
@@ -110,7 +110,7 @@
             <configuration>
               <rules>
                 <requireFilesSize>
-                  <maxsize>4300000</maxsize>
+                  <maxsize>4400000</maxsize>
                   <minsize>3400000</minsize>
                   <files>
                     <file>${project.build.directory}/jacoco-${qualified.bundle.version}.zip</file>
diff --git a/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/PreMain.java b/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/PreMain.java
index 118fa7e6..205fa5b6 100644
--- a/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/PreMain.java
+++ b/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/PreMain.java
@@ -12,9 +12,13 @@
 package org.jacoco.agent.rt.internal;
 
 import java.lang.instrument.Instrumentation;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
 
 import org.jacoco.core.runtime.AgentOptions;
 import org.jacoco.core.runtime.IRuntime;
+import org.jacoco.core.runtime.InjectedClassRuntime;
 import org.jacoco.core.runtime.ModifiedSystemClassRuntime;
 
 /**
@@ -52,7 +56,58 @@ public final class PreMain {
 
 	private static IRuntime createRuntime(final Instrumentation inst)
 			throws Exception {
+
+		if (redefineJavaBaseModule(inst)) {
+			return new InjectedClassRuntime(Object.class, "$JaCoCo");
+		}
+
 		return ModifiedSystemClassRuntime.createFor(inst, "java/lang/UnknownError");
 	}
 
+	/**
+	 * Opens {@code java.base} module for {@link InjectedClassRuntime} when
+	 * executed on Java 9 JREs or higher.
+	 *
+	 * @return <code>true</code> when running on Java 9 or higher,
+	 *         <code>false</code> otherwise
+	 * @throws Exception
+	 *             if unable to open
+	 */
+	private static boolean redefineJavaBaseModule(
+			final Instrumentation instrumentation) throws Exception {
+		try {
+			Class.forName("java.lang.Module");
+		} catch (final ClassNotFoundException e) {
+			return false;
+		}
+
+		Instrumentation.class.getMethod("redefineModule", //
+				Class.forName("java.lang.Module"), //
+				Set.class, //
+				Map.class, //
+				Map.class, //
+				Set.class, //
+				Map.class //
+		).invoke(instrumentation, // instance
+				getModule(Object.class), // module
+				Collections.emptySet(), // extraReads
+				Collections.emptyMap(), // extraExports
+				Collections.singletonMap("java.lang",
+						Collections.singleton(
+								getModule(InjectedClassRuntime.class))), // extraOpens
+				Collections.emptySet(), // extraUses
+				Collections.emptyMap() // extraProvides
+		);
+		return true;
+	}
+
+	/**
+	 * @return {@code cls.getModule()}
+	 */
+	private static Object getModule(final Class<?> cls) throws Exception {
+		return Class.class //
+				.getMethod("getModule") //
+				.invoke(cls);
+	}
+
 }
diff --git a/org.jacoco.core.test/src/org/jacoco/core/runtime/InjectedClassRuntimeTest.java b/org.jacoco.core.test/src/org/jacoco/core/runtime/InjectedClassRuntimeTest.java
new file mode 100644
index 00000000..c3fc8008
--- /dev/null
+++ b/org.jacoco.core.test/src/org/jacoco/core/runtime/InjectedClassRuntimeTest.java
@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2019 Mountainminds GmbH & Co. KG and Contributors
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Evgeny Mandrikov - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.runtime;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.internal.AssumptionViolatedException;
+import org.junit.rules.TestName;
+
+/**
+ * Unit test for {@link InjectedClassRuntime}.
+ */
+public class InjectedClassRuntimeTest extends RuntimeTestBase {
+
+	@Rule
+	public TestName testName = new TestName();
+
+	@BeforeClass
+	public static void requires_at_least_Java_9() {
+		try {
+			Class.forName("java.lang.Module");
+		} catch (final ClassNotFoundException e) {
+			throw new AssumptionViolatedException(
+					"this test requires at least Java 9");
+		}
+	}
+
+	@Override
+	public IRuntime createRuntime() {
+		return new InjectedClassRuntime(InjectedClassRuntimeTest.class,
+				testName.getMethodName());
+	}
+
+	@Test
+	public void startup_should_not_create_duplicate_class_definition()
+			throws Exception {
+		try {
+			createRuntime().startup(null);
+			fail("exception expected");
+		} catch (final InvocationTargetException e) {
+			assertTrue(e.getCause() instanceof LinkageError);
+			assertTrue(e.getCause().getMessage()
+					.contains("duplicate class definition"));
+		}
+	}
+
+}
diff --git a/org.jacoco.core/src/org/jacoco/core/runtime/InjectedClassRuntime.java b/org.jacoco.core/src/org/jacoco/core/runtime/InjectedClassRuntime.java
new file mode 100644
index 00000000..ee7aa1ac
--- /dev/null
+++ b/org.jacoco.core/src/org/jacoco/core/runtime/InjectedClassRuntime.java
@@ -0,0 +1,141 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2019 Mountainminds GmbH & Co. KG and Contributors
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Evgeny Mandrikov - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.runtime;
+
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+/**
+ * {@link IRuntime} which defines a new class using
+ * {@code java.lang.invoke.MethodHandles.Lookup.defineClass} introduced in Java
+ * 9. Module where class will be defined must be opened to at least module of
+ * this class.
+ */
+public class InjectedClassRuntime extends AbstractRuntime {
+
+	private static final String FIELD_NAME = "data";
+
+	private static final String FIELD_TYPE = "Ljava/lang/Object;";
+
+	private final Class<?> locator;
+
+	private final String injectedClassName;
+
+	/**
+	 * Creates a new runtime which will define a class to the same class loader
+	 * and in the same package and protection domain as given class.
+	 *
+	 * @param locator
+	 *            class to identify the target class loader and package
+	 * @param simpleClassName
+	 *            simple name of the class to be defined
+	 */
+	public InjectedClassRuntime(final Class<?> locator,
+			final String simpleClassName) {
+		this.locator = locator;
+		this.injectedClassName = locator.getPackage().getName().replace('.',
+				'/') + '/' + simpleClassName;
+	}
+
+	@Override
+	public void startup(final RuntimeData data) throws Exception {
+		super.startup(data);
+		Lookup //
+				.privateLookupIn(locator, Lookup.lookup()) //
+				.defineClass(createClass(injectedClassName)) //
+				.getField(FIELD_NAME) //
+				.set(null, data);
+	}
+
+	public void shutdown() {
+		// nothing to do
+	}
+
+	public int generateDataAccessor(final long classid, final String classname,
+			final int probecount, final MethodVisitor mv) {
+		mv.visitFieldInsn(Opcodes.GETSTATIC, injectedClassName, FIELD_NAME,
+				FIELD_TYPE);
+
+		RuntimeData.generateAccessCall(classid, classname, probecount, mv);
+
+		return 6;
+	}
+
+	private static byte[] createClass(final String name) {
+		final ClassWriter cw = new ClassWriter(0);
+		cw.visit(Opcodes.V9, Opcodes.ACC_SYNTHETIC | Opcodes.ACC_PUBLIC,
+				name.replace('.', '/'), null, "java/lang/Object", null);
+		cw.visitField(Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, FIELD_NAME,
+				FIELD_TYPE, null, null);
+		cw.visitEnd();
+		return cw.toByteArray();
+	}
+
+	/**
+	 * Provides access to classes {@code java.lang.invoke.MethodHandles} and
+	 * {@code java.lang.invoke.MethodHandles.Lookup} introduced in Java 8.
+	 */
+	private static class Lookup {
+
+		private final Object instance;
+
+		private Lookup(final Object instance) {
+			this.instance = instance;
+		}
+
+		/**
+		 * @return a lookup object for the caller of this method
+		 */
+		static Lookup lookup() throws Exception {
+			return new Lookup(Class //
+					.forName("java.lang.invoke.MethodHandles") //
+					.getMethod("lookup") //
+					.invoke(null));
+		}
+
+		/**
+		 * See corresponding method introduced in Java 9.
+		 *
+		 * @param targetClass
+		 *            the target class
+		 * @param lookup
+		 *            the caller lookup object
+		 * @return a lookup object for the target class, with private access
+		 */
+		static Lookup privateLookupIn(final Class<?> targetClass,
+				final Lookup lookup) throws Exception {
+			return new Lookup(Class //
+					.forName("java.lang.invoke.MethodHandles") //
+					.getMethod("privateLookupIn", Class.class,
+							Class.forName(
+									"java.lang.invoke.MethodHandles$Lookup")) //
+					.invoke(null, targetClass, lookup.instance));
+		}
+
+		/**
+		 * See corresponding method introduced in Java 9.
+		 *
+		 * @param bytes
+		 *            the class bytes
+		 * @return class
+		 */
+		Class<?> defineClass(final byte[] bytes) throws Exception {
+			return (Class<?>) Class //
+					.forName("java.lang.invoke.MethodHandles$Lookup")
+					.getMethod("defineClass", byte[].class)
+					.invoke(this.instance, new Object[] { bytes });
+		}
+
+	}
+
+}
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index e15e653f..c8334399 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -53,6 +53,8 @@
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/819">#819</a>).</li>
   <li>Empty class and sourcefile nodes are preserved and available in XML report
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/817">#817</a>).</li>
+  <li>Agent avoids conflicts with other agents when running on Java 9+
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/829">#829</a>).</li>
 </ul>
 
 <h3>Fixed Bugs</h3>