content: /*******************************************************************************
   * 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.instr;
  
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertSame;
  import static org.junit.Assert.assertTrue;
  
  import org.jacoco.core.internal.instr.InstrSupport;
  import org.jacoco.core.runtime.IRuntime;
  import org.jacoco.core.runtime.RuntimeData;
  import org.jacoco.core.runtime.SystemPropertiesRuntime;
  import org.jacoco.core.test.TargetLoader;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Test;
  import org.objectweb.asm.ClassReader;
  import org.objectweb.asm.ClassVisitor;
  import org.objectweb.asm.ClassWriter;
  import org.objectweb.asm.Label;
  import org.objectweb.asm.MethodVisitor;
  import org.objectweb.asm.Opcodes;
  
  public class ResizeInstructionsTest {
  
  	private IRuntime runtime;
  	private Instrumenter instrumenter;
  
  	private boolean computedCommonSuperClass;
  
  	@Before
  	public void setup() throws Exception {
  		runtime = new SystemPropertiesRuntime();
  		instrumenter = new Instrumenter(runtime);
  		runtime.startup(new RuntimeData());
  		computedCommonSuperClass = false;
  	}
  
  	@After
  	public void teardown() {
  		runtime.shutdown();
  	}
  
  	private class Inner {
  	}
  
  	/**
  	 * Test of ASM bug
  	 * <a href="https://gitlab.ow2.org/asm/asm/issues/317792">#317792</a>.
  	 */
  	@Test
  	public void should_not_loose_InnerClasses_attribute() throws Exception {
  		byte[] source = TargetLoader.getClassDataAsBytes(Inner.class);
  
  		final ClassReader cr = InstrSupport.classReaderFor(source);
  		final ClassWriter cw = new ClassWriter(0);
  		cr.accept(new ClassVisitor(InstrSupport.ASM_API_VERSION, cw) {
  			@Override
  			public void visitEnd() {
  				final MethodVisitor mv = cv.visitMethod(0, "m", "()V", null,
  						null);
  				mv.visitCode();
  				addCauseOfResizeInstructions(mv);
  				mv.visitInsn(Opcodes.NOP);
  				mv.visitMaxs(2, 1);
  				mv.visitEnd();
  				super.visitEnd();
  			}
  		}, 0);
  		source = cw.toByteArray();
  
  		final byte[] bytes = instrumenter.instrument(source, "");
  
  		final TargetLoader targetLoader = new TargetLoader();
  		final Class<?> outer = targetLoader.add(ResizeInstructionsTest.class,
  				TargetLoader.getClassDataAsBytes(ResizeInstructionsTest.class));
  		final Class<?> inner = targetLoader.add(Inner.class, bytes);
  		assertSame(outer, inner.getEnclosingClass());
  		assertNotNull(inner.getEnclosingClass());
  		assertSame(outer, inner.getDeclaringClass());
  		assertNotNull(inner.getDeclaringClass());
  	}
  
  	/**
  	 * Test of ASM bug
  	 * <a href= "https://gitlab.ow2.org/asm/asm/issues/317630">#317630</a> that
  	 * caused {@code java.lang.ClassNotFoundException}.
  	 */
  	@Test
  	public void should_not_require_computation_of_common_superclass()
  			throws Exception {
  		final String className = "Example";
  
  		final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES) {
  			@Override
  			protected String getCommonSuperClass(final String type1,
  					final String type2) {
  				computedCommonSuperClass |= className.equals(type1)
  						|| className.equals(type2);
  				return "java/lang/Object";
  			}
  		};
  		cw.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC, className, null,
  				"java/lang/Object", null);
  		final MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "m", "()V",
  				null, null);
  		mv.visitCode();
  		addCauseOfResizeInstructions(mv);
  		addCauseOfGetCommonSuperClass(mv);
  		mv.visitMaxs(1, 1);
  		mv.visitEnd();
  		cw.visitEnd();
  		final byte[] original = cw.toByteArray();
  		assertTrue(computedCommonSuperClass);
  		new TargetLoader().add(className, original);
  
  		final byte[] instrumented = instrumenter.instrument(original,
  				className);
  		new TargetLoader().add(className, instrumented);
  	}
  
  	/**
  	 * Adds code that requires
  	 * {@link ClassWriter#getCommonSuperClass(String, String)}.
  	 * 
  	 * <pre>
  	 * Object o = this;
  	 * while (true) {
  	 * 	o = (Integer) null;
  	 * }
  	 * </pre>
  	 */
  	private static void addCauseOfGetCommonSuperClass(final MethodVisitor mv) {
  		mv.visitVarInsn(Opcodes.ALOAD, 0);
  		mv.visitVarInsn(Opcodes.ASTORE, 1);
  		Label label = new Label();
  		mv.visitLabel(label);
  		mv.visitInsn(Opcodes.ACONST_NULL);
  		mv.visitTypeInsn(Opcodes.CHECKCAST, "java/lang/Integer");
  		mv.visitVarInsn(Opcodes.ASTORE, 1);
  		mv.visitJumpInsn(Opcodes.GOTO, label);
  	}
  
  	/**
  	 * Adds code that triggers usage of
  	 * {@link org.objectweb.asm.MethodWriter#COMPUTE_INSERTED_FRAMES} during
  	 * instrumentation.
  	 */
  	private static void addCauseOfResizeInstructions(final MethodVisitor mv) {
  		mv.visitInsn(Opcodes.ICONST_0);
  		mv.visitInsn(Opcodes.ICONST_1);
  		final Label target = new Label();
  		mv.visitJumpInsn(Opcodes.IFLE, target);
  		for (int i = 0; i < Short.MAX_VALUE; i++) {
  			mv.visitInsn(Opcodes.NOP);
  		}
  		mv.visitLabel(target);
  	}
  
  }
  