content: /**
   * Copyright (c) 2013, Andre Steingress
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
   * following conditions are met:
   *
   * 1.) Redistributions of source code must retain the above copyright notice, this list of conditions and the following
   * disclaimer.
   * 2.) Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
   * disclaimer in the documentation and/or other materials provided with the distribution.
   * 3.) Neither the name of Andre Steingress nor the names of its contributors may be used to endorse or
   * promote products derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
   * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.gcontracts.ast;
  
  import org.codehaus.groovy.control.SourceUnit;
  import org.codehaus.groovy.control.io.ReaderSource;
  import org.codehaus.groovy.transform.ASTTransformation;
  
  import java.lang.reflect.Field;
  
  /**
   * Base AST transformation encapsulating all common helper methods and implementing {@link org.codehaus.groovy.transform.ASTTransformation}.
   *
   * @see org.codehaus.groovy.transform.ASTTransformation
   *
   * @author ast
   */
  public abstract class BaseASTTransformation implements ASTTransformation {
  
      /**
       * Reads the protected <tt>source1</tt> instance variable of {@link org.codehaus.groovy.control.SourceUnit}.
       *
       * @param unit the {@link org.codehaus.groovy.control.SourceUnit} to retrieve the {@link org.codehaus.groovy.control.io.ReaderSource} from
       * @return the {@link org.codehaus.groovy.control.io.ReaderSource} of the given <tt>unit</tt>.
       */
      protected ReaderSource getReaderSource(SourceUnit unit)  {
  
          try {
              Class sourceUnitClass = unit.getClass();
  
              while (sourceUnitClass != SourceUnit.class)  {
                  sourceUnitClass = sourceUnitClass.getSuperclass();
              }
  
              Field field = sourceUnitClass.getDeclaredField("source1");
              field.setAccessible(true);
  
              return (ReaderSource) field.get(unit);
          } catch (Exception e) {
              return null;
          }
      }
  
  }
  