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.internal.analysis.filter;
  
  import org.objectweb.asm.Opcodes;
  import org.objectweb.asm.tree.AbstractInsnNode;
  import org.objectweb.asm.tree.MethodNode;
  import org.objectweb.asm.tree.TryCatchBlockNode;
  
  /**
   * Filters code that is generated for synchronized statement.
   */
  public final class SynchronizedFilter implements IFilter {
  
  	public void filter(final MethodNode methodNode,
  			final IFilterContext context, final IFilterOutput output) {
  		for (final TryCatchBlockNode tryCatch : methodNode.tryCatchBlocks) {
  			if (tryCatch.type != null) {
  				continue;
  			}
  			if (tryCatch.start == tryCatch.handler) {
  				continue;
  			}
  			final AbstractInsnNode to = new Matcher(tryCatch.handler).match();
  			if (to == null) {
  				continue;
  			}
  			output.ignore(tryCatch.handler, to);
  		}
  	}
  
  	private static class Matcher extends AbstractMatcher {
  		private final AbstractInsnNode start;
  
  		private Matcher(final AbstractInsnNode start) {
  			this.start = start;
  		}
  
  		private AbstractInsnNode match() {
  			if (nextIsEcj() || nextIsJavac()) {
  				return cursor;
  			}
  			return null;
  		}
  
  		private boolean nextIsJavac() {
  			cursor = start;
  			nextIsVar(Opcodes.ASTORE, "t");
  			nextIs(Opcodes.ALOAD);
  			nextIs(Opcodes.MONITOREXIT);
  			nextIsVar(Opcodes.ALOAD, "t");
  			nextIs(Opcodes.ATHROW);
  			return cursor != null;
  		}
  
  		private boolean nextIsEcj() {
  			cursor = start;
  			nextIs(Opcodes.ALOAD);
  			nextIs(Opcodes.MONITOREXIT);
  			nextIs(Opcodes.ATHROW);
  			return cursor != null;
  		}
  	}
  
  }
  