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: StartsWithCall.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.INVOKEVIRTUAL;
028 import org.apache.bcel.generic.InstructionList;
029 import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
030 import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
031 import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
032 import org.apache.xalan.xsltc.compiler.util.Type;
033 import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
034
035 /**
036 * @author Jacek Ambroziak
037 * @author Santiago Pericas-Geertsen
038 * @author Morten Jorgensen
039 */
040 final class StartsWithCall extends FunctionCall {
041
042 private Expression _base = null;
043 private Expression _token = null;
044
045 /**
046 * Create a starts-with() call - two arguments, both strings
047 */
048 public StartsWithCall(QName fname, Vector arguments) {
049 super(fname, arguments);
050 }
051
052 /**
053 * Type check the two parameters for this function
054 */
055 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
056
057 // Check that the function was passed exactly two arguments
058 if (argumentCount() != 2) {
059 ErrorMsg err = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR,
060 getName(), this);
061 throw new TypeCheckError(err);
062 }
063
064 // The first argument must be a String, or cast to a String
065 _base = argument(0);
066 Type baseType = _base.typeCheck(stable);
067 if (baseType != Type.String)
068 _base = new CastExpr(_base, Type.String);
069
070 // The second argument must also be a String, or cast to a String
071 _token = argument(1);
072 Type tokenType = _token.typeCheck(stable);
073 if (tokenType != Type.String)
074 _token = new CastExpr(_token, Type.String);
075
076 return _type = Type.Boolean;
077 }
078
079 /**
080 * Compile the expression - leave boolean expression on stack
081 */
082 public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
083 final ConstantPoolGen cpg = classGen.getConstantPool();
084 final InstructionList il = methodGen.getInstructionList();
085 _base.translate(classGen, methodGen);
086 _token.translate(classGen, methodGen);
087 il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
088 "startsWith",
089 "("+STRING_SIG+")Z")));
090 }
091 }