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:
   *    Nikolay Krasko - initial API and implementation
   *
   *******************************************************************************/
  package org.jacoco.core.internal.analysis.filter;
  
  import org.objectweb.asm.tree.AbstractInsnNode;
  import org.objectweb.asm.tree.MethodNode;
  
  /**
   * Filters methods generated by the Kotlin compiler. Kotlin classes are
   * identified by the <code>@kotlin.Metadata</code> annotations. In such classes
   * generated methods do not have line numbers.
   */
  public class KotlinGeneratedFilter implements IFilter {
  
  	static final String KOTLIN_METADATA_DESC = "Lkotlin/Metadata;";
  
  	static boolean isKotlinClass(final IFilterContext context) {
  		return context.getClassAnnotations().contains(KOTLIN_METADATA_DESC);
  	}
  
  	public void filter(final MethodNode methodNode,
  			final IFilterContext context, final IFilterOutput output) {
  
  		if (context.getSourceFileName() == null) {
  			// probably full debug information is missing
  			// disabled filtering as all methods might be erroneously skipped
  			return;
  		}
  
  		if (!isKotlinClass(context)) {
  			return;
  		}
  
  		if (hasLineNumber(methodNode)) {
  			return;
  		}
  
  		output.ignore(methodNode.instructions.getFirst(),
  				methodNode.instructions.getLast());
  	}
  
  	private boolean hasLineNumber(final MethodNode methodNode) {
  		for (AbstractInsnNode i = methodNode.instructions
  				.getFirst(); i != null; i = i.getNext()) {
  			if (AbstractInsnNode.LINE == i.getType()) {
  				return true;
  			}
  		}
  		return false;
  	}
  
  }
  