package org.apache.maven.shared.dependency.analyzer.asm;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import org.objectweb.asm.AnnotationVisitor;
  import org.objectweb.asm.Label;
  import org.objectweb.asm.MethodVisitor;
  import org.objectweb.asm.Opcodes;
  import org.objectweb.asm.Type;
  import org.objectweb.asm.TypePath;
  import org.objectweb.asm.signature.SignatureReader;
  import org.objectweb.asm.signature.SignatureVisitor;
  
  
  /**
   * Computes the set of classes referenced by visited code.
   * Inspired by <code>org.objectweb.asm.depend.DependencyVisitor</code> in the ASM dependencies example.
   *
   * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
   * @version $Id$
   */
  public class DefaultMethodVisitor
      extends MethodVisitor
  {
      private final AnnotationVisitor annotationVisitor;
  
      private final SignatureVisitor signatureVisitor;
  
      private final ResultCollector resultCollector;
  
      public DefaultMethodVisitor( AnnotationVisitor annotationVisitor, SignatureVisitor signatureVisitor,
                                   ResultCollector resultCollector )
      {
          super( Opcodes.ASM6 );
          this.annotationVisitor = annotationVisitor;
          this.signatureVisitor = signatureVisitor;
          this.resultCollector = resultCollector;
      }
  
      public AnnotationVisitor visitAnnotation( final String desc, final boolean visible )
      {
          resultCollector.addDesc( desc );
  
          return annotationVisitor;
      }
  
      @Override
      public AnnotationVisitor visitTypeAnnotation( int typeRef, TypePath typePath, String desc, boolean visible )
      {
          resultCollector.addDesc( desc );
  
          return annotationVisitor;
      }
  
      public AnnotationVisitor visitParameterAnnotation( final int parameter, final String desc, final boolean visible )
      {
          resultCollector.addDesc( desc );
  
          return annotationVisitor;
      }
  
      public void visitTypeInsn( final int opcode, final String desc )
      {
          if ( desc.charAt( 0 ) == '[' )
          {
              resultCollector.addDesc( desc );
          }
          else
          {
              resultCollector.addName( desc );
          }
      }
  
      public void visitFieldInsn( final int opcode, final String owner, final String name, final String desc )
      {
          resultCollector.addName( owner );
          /*
           * NOTE: Merely accessing a field does not impose a direct dependency on its type. For example, the code line
           * <code>java.lang.Object var = bean.field;</code> does not directly depend on the type of the field. A direct
           * dependency is only introduced when the code explicitly references the field's type by means of a variable
           * declaration or a type check/cast. Those cases are handled by other visitor callbacks.
           */
     }
 
     @Override
     public void visitMethodInsn( int opcode, String owner, String name, String desc, boolean itf )
     {
         resultCollector.addName( owner );
     }
 
     public void visitLdcInsn( final Object cst )
     {
         if ( cst instanceof Type )
         {
             resultCollector.addType( (Type) cst );
         }
     }
 
     public void visitMultiANewArrayInsn( final String desc, final int dims )
     {
         resultCollector.addDesc( desc );
     }
 
     public void visitTryCatchBlock( final Label start, final Label end, final Label handler, final String type )
     {
         resultCollector.addName( type );
     }
 
     public void visitLocalVariable( final String name, final String desc, final String signature, final Label start,
                                     final Label end, final int index )
     {
         if ( signature == null )
         {
             resultCollector.addDesc( desc );
         }
         else
         {
             addTypeSignature( signature );
         }
     }
 
 
 
     private void addTypeSignature( final String signature )
     {
         if ( signature != null )
         {
             new SignatureReader( signature ).acceptType( signatureVisitor );
         }
     }
 }