/*
* 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: VoidType.java 468649 2006-10-28 07:00:55Z minchau $
*/
package org.apache.xalan.xsltc.compiler.util;
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 Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*/
public final class VoidType extends Type {
protected VoidType() {}
public String toString() {
return "void";
}
public boolean identicalTo(Type other) {
return this == other;
}
public String toSignature() {
return "V";
}
public org.apache.bcel.generic.Type toJCType() {
return null; // should never be called
}
public Instruction POP() {
return NOP;
}
/**
* 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);
}
}
/**
* Translates a void into a string by pushing the empty string ''.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
StringType type) {
final InstructionList il = methodGen.getInstructionList();
il.append(new PUSH(classGen.getConstantPool(), ""));
}
/**
* Translates an external (primitive) Java type into a void.
* Only an external "void" can be converted to this class.
*/
public void translateFrom(ClassGenerator classGen, MethodGenerator methodGen,
Class clazz) {
if (!clazz.getName().equals("void")) {
ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
toString(), clazz.getName());
classGen.getParser().reportError(Constants.FATAL, err);
}
}
}