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: LastCall.java 468650 2006-10-28 07:03:30Z minchau $
020     */
021    
022    package org.apache.xalan.xsltc.compiler;
023    
024    import org.apache.bcel.generic.ConstantPoolGen;
025    import org.apache.bcel.generic.ILOAD;
026    import org.apache.bcel.generic.INVOKEINTERFACE;
027    import org.apache.bcel.generic.InstructionList;
028    import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
029    import org.apache.xalan.xsltc.compiler.util.CompareGenerator;
030    import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
031    import org.apache.xalan.xsltc.compiler.util.TestGenerator;
032    
033    /**
034     * @author Jacek Ambroziak
035     * @author Santiago Pericas-Geertsen
036     */
037    final class LastCall extends FunctionCall {
038    
039        public LastCall(QName fname) {
040            super(fname);
041        }
042    
043        public boolean hasPositionCall() {
044            return true;
045        }
046    
047        public boolean hasLastCall() {
048            return true;
049        }
050    
051        public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
052            final InstructionList il = methodGen.getInstructionList();
053    
054            if (methodGen instanceof CompareGenerator) {
055                il.append(((CompareGenerator)methodGen).loadLastNode());
056            }
057            else if (methodGen instanceof TestGenerator) {
058                il.append(new ILOAD(LAST_INDEX));
059            }
060            else {
061                final ConstantPoolGen cpg = classGen.getConstantPool();
062                final int getLast = cpg.addInterfaceMethodref(NODE_ITERATOR,
063                                                              "getLast", 
064                                                              "()I");
065                il.append(methodGen.loadIterator());
066                il.append(new INVOKEINTERFACE(getLast, 1));
067            }
068        }
069    }