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.JumpInsnNode;
  import org.objectweb.asm.tree.LdcInsnNode;
  import org.objectweb.asm.tree.MethodNode;
  
  /**
   * Filters branch in bytecode that Kotlin compiler generates for "unsafe" cast
   * operator.
   */
  public final class KotlinUnsafeCastOperatorFilter implements IFilter {
  
  	private static final String KOTLIN_TYPE_CAST_EXCEPTION = "kotlin/TypeCastException";
  
  	public void filter(final MethodNode methodNode,
  			final IFilterContext context, final IFilterOutput output) {
  		final Matcher matcher = new Matcher();
  		for (AbstractInsnNode i = methodNode.instructions
  				.getFirst(); i != null; i = i.getNext()) {
  			matcher.match(i, output);
  		}
  	}
  
  	private static class Matcher extends AbstractMatcher {
  		public void match(final AbstractInsnNode start,
  				final IFilterOutput output) {
  
  			if (Opcodes.IFNONNULL != start.getOpcode()) {
  				return;
  			}
  			cursor = start;
  
  			nextIsType(Opcodes.NEW, KOTLIN_TYPE_CAST_EXCEPTION);
  			nextIs(Opcodes.DUP);
  			nextIs(Opcodes.LDC);
  			if (cursor == null) {
  				return;
  			}
  			final LdcInsnNode ldc = (LdcInsnNode) cursor;
  			if (!(ldc.cst instanceof String && ((String) ldc.cst)
  					.startsWith("null cannot be cast to non-null type"))) {
  				return;
  			}
  			nextIsInvoke(Opcodes.INVOKESPECIAL, KOTLIN_TYPE_CAST_EXCEPTION,
  					"<init>", "(Ljava/lang/String;)V");
  			nextIs(Opcodes.ATHROW);
  			if (cursor == null) {
  				return;
  			}
  			if (cursor.getNext() != ((JumpInsnNode) start).label) {
  				return;
  			}
  
  			output.ignore(start, cursor);
  		}
  	}
  
  }
  