code: /*
   * 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler.util;
  
  import org.apache.bcel.generic.ALOAD;
  import org.apache.bcel.generic.ASTORE;
  import org.apache.bcel.generic.BranchHandle;
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.GOTO;
  import org.apache.bcel.generic.IFNULL;
  import org.apache.bcel.generic.INVOKEVIRTUAL;
  import org.apache.bcel.generic.Instruction;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.PUSH;
  import org.apache.xalan.xsltc.compiler.Constants;
  
  /**
   * @author Todd Miller
   * @author Santiago Pericas-Geertsen
   */
  public final class ObjectType extends Type {
      
      private String _javaClassName = "java.lang.Object";
      private Class  _clazz = java.lang.Object.class;
  
      /**
       * Used to represent a Java Class type such is required to support 
       * non-static java functions. 
       * @param javaClassName name of the class such as 'com.foo.Processor'
       */
      protected ObjectType(String javaClassName) {
  	_javaClassName = javaClassName;
  
  	try {
            _clazz = ObjectFactory.findProviderClass(
              javaClassName, ObjectFactory.findClassLoader(), true);
  	}
  	catch (ClassNotFoundException e) {
  	  _clazz = null;
  	}
      }
      
      protected ObjectType(Class clazz) {
          _clazz = clazz;
          _javaClassName = clazz.getName();	
      }
      
      /**
       * Must return the same value for all ObjectType instances. This is
       * needed in CastExpr to ensure the mapping table is used correctly.
       */
      public int hashCode() {
          return java.lang.Object.class.hashCode();
      }
      
      public boolean equals(Object obj) {
          return (obj instanceof ObjectType);
      }
  
      public String getJavaClassName() {
  	return _javaClassName;
      }
      
      public Class getJavaClass() {
          return _clazz;	
      }
  
      public String toString() {
  	return _javaClassName;
      }
  
      public boolean identicalTo(Type other) {
  	return this == other;
      }
  
      public String toSignature() {
  	final StringBuffer result = new StringBuffer("L");
  	result.append(_javaClassName.replace('.', '/')).append(';');
  	return result.toString();
      }
  
      public org.apache.bcel.generic.Type toJCType() {
  	return Util.getJCRefType(toSignature());
      }
  
      /**
       * Translates a void into an object of internal type <code>type</code>.
       * This translation is needed when calling external functions
       * that return void.
       *
       * @see	org.apache.xalan.xsltc.compiler.util.Type#translateTo
       */
      public void translateTo(ClassGenerator classGen, MethodGenerator methodGen, 
  			    Type type) {
  	if (type == Type.String) {
  	    translateTo(classGen, methodGen, (StringType) type);
  	}
  	else {
  	    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
  					toString(), type.toString());
  	    classGen.getParser().reportError(Constants.FATAL, err);
  	}
      }
  
      /**
       * Expects an integer on the stack and pushes its string value by calling
       * <code>Integer.toString(int i)</code>.
       *
       * @see	org.apache.xalan.xsltc.compiler.util.Type#translateTo
       */
      public void translateTo(ClassGenerator classGen, MethodGenerator methodGen, 
  			    StringType type) {
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  
  	il.append(DUP);
  	final BranchHandle ifNull = il.append(new IFNULL(null));
  	il.append(new INVOKEVIRTUAL(cpg.addMethodref(_javaClassName,
  						    "toString",
  						    "()" + STRING_SIG)));
  	final BranchHandle gotobh = il.append(new GOTO(null));
  	ifNull.setTarget(il.append(POP));
  	il.append(new PUSH(cpg, ""));
  	gotobh.setTarget(il.append(NOP));
      }
  
      /**
       * Translates an object of this type to the external (Java) type denoted
       * by <code>clazz</code>. This method is used to translate parameters 
       * when external functions are called.
       */ 
      public void translateTo(ClassGenerator classGen, MethodGenerator methodGen, 
  			    Class clazz) {
          if (clazz.isAssignableFrom(_clazz))
  	    methodGen.getInstructionList().append(NOP);
  	else {
  	    ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
  			       toString(), clazz.getClass().toString());
  	    classGen.getParser().reportError(Constants.FATAL, err);	  	
  	}
      }
  	
      /**
       * Translates an external Java type into an Object type 
       */
      public void translateFrom(ClassGenerator classGen, 
  			      MethodGenerator methodGen, Class clazz) {
  	methodGen.getInstructionList().append(NOP);
      }
  
      public Instruction LOAD(int slot) {
  	return new ALOAD(slot);
      }
  	
      public Instruction STORE(int slot) {
  	return new ASTORE(slot);
      }
  }
  