Avoid UndeclaredThrowableStrategy with 1.8 bytecode level (CGLIB 3.3)

ClassLoaderAwareUndeclaredThrowableStrategy fails with a VerifyError on recent JDKs after the CGLIB 3.3 upgrade. The alternative is to replace it with a plain ClassLoaderAwareGeneratorStrategy (extracted from CglibSubclassingInstantiationStrategy) and custom UndeclaredThrowableException handling in CglibMethodInvocation.

See gh-23453

spring-aop/src/main/java/org/springframework/aop/framework/CglibAopProxy.java

@@ -38,7 +38,7 @@ import org.springframework.aop.PointcutAdvisor;
 import org.springframework.aop.RawTargetAccess;
 import org.springframework.aop.TargetSource;
 import org.springframework.aop.support.AopUtils;
-import org.springframework.cglib.core.ClassGenerator;
+import org.springframework.cglib.core.ClassLoaderAwareGeneratorStrategy;
 import org.springframework.cglib.core.CodeGenerationException;
 import org.springframework.cglib.core.SpringNamingPolicy;
 import org.springframework.cglib.proxy.Callback;
@@ -49,12 +49,12 @@ import org.springframework.cglib.proxy.Factory;
 import org.springframework.cglib.proxy.MethodInterceptor;
 import org.springframework.cglib.proxy.MethodProxy;
 import org.springframework.cglib.proxy.NoOp;
-import org.springframework.cglib.transform.impl.UndeclaredThrowableStrategy;
 import org.springframework.core.SmartClassLoader;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * CGLIB-based {@link AopProxy} implementation for the Spring AOP framework.
@@ -189,7 +189,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 			enhancer.setSuperclass(proxySuperClass);
 			enhancer.setInterfaces(AopProxyUtils.completeProxiedInterfaces(this.advised));
 			enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
-			enhancer.setStrategy(new ClassLoaderAwareUndeclaredThrowableStrategy(classLoader));
+			enhancer.setStrategy(new ClassLoaderAwareGeneratorStrategy(classLoader));
 
 			Callback[] callbacks = getCallbacks(rootClass);
 			Class<?>[] types = new Class<?>[callbacks.length];
@@ -634,8 +634,8 @@ class CglibAopProxy implements AopProxy, Serializable {
 		@Override
 		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
-			MethodInvocation invocation = new CglibMethodInvocation(proxy, this.target, method, args,
-					this.targetClass, this.adviceChain, methodProxy);
+			MethodInvocation invocation = new CglibMethodInvocation(
+					proxy, this.target, method, args, this.targetClass, this.adviceChain, methodProxy);
 			// If we get here, we need to create a MethodInvocation.
 			Object retVal = invocation.proceed();
 			retVal = processReturnType(proxy, this.target, method, retVal);
@@ -740,6 +740,25 @@ class CglibAopProxy implements AopProxy, Serializable {
 					methodProxy : null);
 		}
 
+		@Override
+		@Nullable
+		public Object proceed() throws Throwable {
+			try {
+				return super.proceed();
+			}
+			catch (RuntimeException ex) {
+				throw ex;
+			}
+			catch (Exception ex) {
+				if (ReflectionUtils.declaresException(getMethod(), ex.getClass())) {
+					throw ex;
+				}
+				else {
+					throw new UndeclaredThrowableException(ex);
+				}
+			}
+		}
+
 		/**
 		 * Gives a marginal performance improvement versus using reflection to
 		 * invoke the target when invoking public methods.
@@ -968,52 +987,4 @@ class CglibAopProxy implements AopProxy, Serializable {
 		}
 	}
 
-
-	/**
-	 * CGLIB GeneratorStrategy variant which exposes the application ClassLoader
-	 * as thread context ClassLoader for the time of class generation
-	 * (in order for ASM to pick it up when doing common superclass resolution).
-	 */
-	private static class ClassLoaderAwareUndeclaredThrowableStrategy extends UndeclaredThrowableStrategy {
-
-		@Nullable
-		private final ClassLoader classLoader;
-
-		public ClassLoaderAwareUndeclaredThrowableStrategy(@Nullable ClassLoader classLoader) {
-			super(UndeclaredThrowableException.class);
-			this.classLoader = classLoader;
-		}
-
-		@Override
-		public byte[] generate(ClassGenerator cg) throws Exception {
-			if (this.classLoader == null) {
-				return super.generate(cg);
-			}
-
-			Thread currentThread = Thread.currentThread();
-			ClassLoader threadContextClassLoader;
-			try {
-				threadContextClassLoader = currentThread.getContextClassLoader();
-			}
-			catch (Throwable ex) {
-				// Cannot access thread context ClassLoader - falling back...
-				return super.generate(cg);
-			}
-
-			boolean overrideClassLoader = !this.classLoader.equals(threadContextClassLoader);
-			if (overrideClassLoader) {
-				currentThread.setContextClassLoader(this.classLoader);
-			}
-			try {
-				return super.generate(cg);
-			}
-			finally {
-				if (overrideClassLoader) {
-					// Reset original thread context ClassLoader.
-					currentThread.setContextClassLoader(threadContextClassLoader);
-				}
-			}
-		}
-	}
-
 }

spring-aop/src/main/java/org/springframework/aop/framework/ReflectiveMethodInvocation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -68,7 +68,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 
 	protected final Method method;
 
-	protected Object[] arguments = new Object[0];
+	protected Object[] arguments;
 
 	@Nullable
 	private final Class<?> targetClass;
@@ -158,7 +158,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	@Override
 	@Nullable
 	public Object proceed() throws Throwable {
-		//	We start with an index of -1 and increment early.
+		// We start with an index of -1 and increment early.
 		if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {
 			return invokeJoinpoint();
 		}

spring-beans/src/main/java/org/springframework/beans/factory/support/CglibSubclassingInstantiationStrategy.java

@@ -26,8 +26,7 @@ import org.springframework.beans.BeanInstantiationException;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
-import org.springframework.cglib.core.ClassGenerator;
-import org.springframework.cglib.core.DefaultGeneratorStrategy;
+import org.springframework.cglib.core.ClassLoaderAwareGeneratorStrategy;
 import org.springframework.cglib.core.SpringNamingPolicy;
 import org.springframework.cglib.proxy.Callback;
 import org.springframework.cglib.proxy.CallbackFilter;
@@ -187,53 +186,6 @@ public class CglibSubclassingInstantiationStrategy extends SimpleInstantiationSt
 	}
 
 
-	/**
-	 * CGLIB GeneratorStrategy variant which exposes the application ClassLoader
-	 * as thread context ClassLoader for the time of class generation
-	 * (in order for ASM to pick it up when doing common superclass resolution).
-	 */
-	private static class ClassLoaderAwareGeneratorStrategy extends DefaultGeneratorStrategy {
-
-		@Nullable
-		private final ClassLoader classLoader;
-
-		public ClassLoaderAwareGeneratorStrategy(@Nullable ClassLoader classLoader) {
-			this.classLoader = classLoader;
-		}
-
-		@Override
-		public byte[] generate(ClassGenerator cg) throws Exception {
-			if (this.classLoader == null) {
-				return super.generate(cg);
-			}
-
-			Thread currentThread = Thread.currentThread();
-			ClassLoader threadContextClassLoader;
-			try {
-				threadContextClassLoader = currentThread.getContextClassLoader();
-			}
-			catch (Throwable ex) {
-				// Cannot access thread context ClassLoader - falling back...
-				return super.generate(cg);
-			}
-
-			boolean overrideClassLoader = !this.classLoader.equals(threadContextClassLoader);
-			if (overrideClassLoader) {
-				currentThread.setContextClassLoader(this.classLoader);
-			}
-			try {
-				return super.generate(cg);
-			}
-			finally {
-				if (overrideClassLoader) {
-					// Reset original thread context ClassLoader.
-					currentThread.setContextClassLoader(threadContextClassLoader);
-				}
-			}
-		}
-	}
-
-
 	/**
 	 * CGLIB callback for filtering method interception behavior.
 	 */

spring-core/src/main/java/org/springframework/cglib/core/ClassLoaderAwareGeneratorStrategy.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.cglib.core;
+
+/**
+ * CGLIB GeneratorStrategy variant which exposes the application ClassLoader
+ * as current thread context ClassLoader for the time of class generation.
+ * The ASM ClassWriter in Spring's ASM variant will pick it up when doing
+ * common superclass resolution.
+ *
+ * @author Juergen Hoeller
+ * @since 5.2
+ */
+public class ClassLoaderAwareGeneratorStrategy extends DefaultGeneratorStrategy {
+
+	private final ClassLoader classLoader;
+
+	public ClassLoaderAwareGeneratorStrategy(ClassLoader classLoader) {
+		this.classLoader = classLoader;
+	}
+
+	@Override
+	public byte[] generate(ClassGenerator cg) throws Exception {
+		if (this.classLoader == null) {
+			return super.generate(cg);
+		}
+
+		Thread currentThread = Thread.currentThread();
+		ClassLoader threadContextClassLoader;
+		try {
+			threadContextClassLoader = currentThread.getContextClassLoader();
+		}
+		catch (Throwable ex) {
+			// Cannot access thread context ClassLoader - falling back...
+			return super.generate(cg);
+		}
+
+		boolean overrideClassLoader = !this.classLoader.equals(threadContextClassLoader);
+		if (overrideClassLoader) {
+			currentThread.setContextClassLoader(this.classLoader);
+		}
+		try {
+			return super.generate(cg);
+		}
+		finally {
+			if (overrideClassLoader) {
+				// Reset original thread context ClassLoader.
+				currentThread.setContextClassLoader(threadContextClassLoader);
+			}
+		}
+	}
+
+}

spring-core/src/main/java/org/springframework/cglib/package-info.java

@@ -1,6 +1,6 @@
 /**
  * Spring's repackaging of
- * <a href="https://github.com/cglib/cglib">CGLIB 3.2</a>
+ * <a href="https://github.com/cglib/cglib">CGLIB 3.3</a>
  * (with Spring-specific patches; for internal use only).
  *
  * <p>This repackaging technique avoids any potential conflicts with