001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: ConcatCall.java 468650 2006-10-28 07:03:30Z minchau $
020 */
021
022 package org.apache.xalan.xsltc.compiler;
023
024 import java.util.Vector;
025
026 import org.apache.bcel.generic.ConstantPoolGen;
027 import org.apache.bcel.generic.INVOKESPECIAL;
028 import org.apache.bcel.generic.INVOKEVIRTUAL;
029 import org.apache.bcel.generic.Instruction;
030 import org.apache.bcel.generic.InstructionList;
031 import org.apache.bcel.generic.NEW;
032 import org.apache.bcel.generic.PUSH;
033 import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
034 import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
035 import org.apache.xalan.xsltc.compiler.util.Type;
036 import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
037
038 /**
039 * @author Jacek Ambroziak
040 * @author Santiago Pericas-Geertsen
041 */
042 final class ConcatCall extends FunctionCall {
043 public ConcatCall(QName fname, Vector arguments) {
044 super(fname, arguments);
045 }
046
047 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
048 for (int i = 0; i < argumentCount(); i++) {
049 final Expression exp = argument(i);
050 if (!exp.typeCheck(stable).identicalTo(Type.String)) {
051 setArgument(i, new CastExpr(exp, Type.String));
052 }
053 }
054 return _type = Type.String;
055 }
056
057 /** translate leaves a String on the stack */
058 public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
059 final ConstantPoolGen cpg = classGen.getConstantPool();
060 final InstructionList il = methodGen.getInstructionList();
061 final int nArgs = argumentCount();
062
063 switch (nArgs) {
064 case 0:
065 il.append(new PUSH(cpg, EMPTYSTRING));
066 break;
067
068 case 1:
069 argument().translate(classGen, methodGen);
070 break;
071
072 default:
073 final int initBuffer = cpg.addMethodref(STRING_BUFFER_CLASS,
074 "<init>", "()V");
075 final Instruction append =
076 new INVOKEVIRTUAL(cpg.addMethodref(STRING_BUFFER_CLASS,
077 "append",
078 "("+STRING_SIG+")"
079 +STRING_BUFFER_SIG));
080
081 final int toString = cpg.addMethodref(STRING_BUFFER_CLASS,
082 "toString",
083 "()"+STRING_SIG);
084
085 il.append(new NEW(cpg.addClass(STRING_BUFFER_CLASS)));
086 il.append(DUP);
087 il.append(new INVOKESPECIAL(initBuffer));
088 for (int i = 0; i < nArgs; i++) {
089 argument(i).translate(classGen, methodGen);
090 il.append(append);
091 }
092 il.append(new INVOKEVIRTUAL(toString));
093 }
094 }
095 }