1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5/* 6 * Licensed to the Apache Software Foundation (ASF) under one or more 7 * contributor license agreements. See the NOTICE file distributed with 8 * this work for additional information regarding copyright ownership. 9 * The ASF licenses this file to You under the Apache License, Version 2.0 10 * (the "License"); you may not use this file except in compliance with 11 * the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 */ 21 22package com.sun.org.apache.xalan.internal.xsltc.compiler; 23 24import com.sun.org.apache.bcel.internal.generic.ALOAD; 25import com.sun.org.apache.bcel.internal.generic.ASTORE; 26import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen; 27import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE; 28import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL; 29import com.sun.org.apache.bcel.internal.generic.InstructionList; 30import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; 31import com.sun.org.apache.bcel.internal.generic.NEW; 32import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator; 33import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator; 34import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType; 35import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type; 36import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError; 37import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util; 38 39/** 40 * @author Jacek Ambroziak 41 * @author Santiago Pericas-Geertsen 42 */ 43final class AbsoluteLocationPath extends Expression { 44 private Expression _path; // may be null 45 46 public AbsoluteLocationPath() { 47 _path = null; 48 } 49 50 public AbsoluteLocationPath(Expression path) { 51 _path = path; 52 if (path != null) { 53 _path.setParent(this); 54 } 55 } 56 57 public void setParser(Parser parser) { 58 super.setParser(parser); 59 if (_path != null) { 60 _path.setParser(parser); 61 } 62 } 63 64 public Expression getPath() { 65 return(_path); 66 } 67 68 public String toString() { 69 return "AbsoluteLocationPath(" + 70 (_path != null ? _path.toString() : "null") + ')'; 71 } 72 73 public Type typeCheck(SymbolTable stable) throws TypeCheckError { 74 if (_path != null) { 75 final Type ptype = _path.typeCheck(stable); 76 if (ptype instanceof NodeType) { // promote to node-set 77 _path = new CastExpr(_path, Type.NodeSet); 78 } 79 } 80 return _type = Type.NodeSet; 81 } 82 83 public void translate(ClassGenerator classGen, MethodGenerator methodGen) { 84 final ConstantPoolGen cpg = classGen.getConstantPool(); 85 final InstructionList il = methodGen.getInstructionList(); 86 if (_path != null) { 87 final int initAI = cpg.addMethodref(ABSOLUTE_ITERATOR, 88 "<init>", 89 "(" 90 + NODE_ITERATOR_SIG 91 + ")V"); 92 93 // Compile relative path iterator(s) 94 // 95 // Backwards branches are prohibited if an uninitialized object is 96 // on the stack by section 4.9.4 of the JVM Specification, 2nd Ed. 97 // We don't know whether this code might contain backwards branches, 98 // so we mustn't create the new object until after we've created 99 // this argument to its constructor. Instead we calculate the 100 // value of the argument to the constructor first, store it in 101 // a temporary variable, create the object and reload the argument 102 // from the temporary to avoid the problem. 103 _path.translate(classGen, methodGen); 104 LocalVariableGen relPathIterator 105 = methodGen.addLocalVariable("abs_location_path_tmp", 106 Util.getJCRefType(NODE_ITERATOR_SIG), 107 null, null); 108 relPathIterator.setStart( 109 il.append(new ASTORE(relPathIterator.getIndex()))); 110 111 // Create new AbsoluteIterator 112 il.append(new NEW(cpg.addClass(ABSOLUTE_ITERATOR))); 113 il.append(DUP); 114 relPathIterator.setEnd( 115 il.append(new ALOAD(relPathIterator.getIndex()))); 116 117 // Initialize AbsoluteIterator with iterator from the stack 118 il.append(new INVOKESPECIAL(initAI)); 119 } 120 else { 121 final int gitr = cpg.addInterfaceMethodref(DOM_INTF, 122 "getIterator", 123 "()"+NODE_ITERATOR_SIG); 124 il.append(methodGen.loadDOM()); 125 il.append(new INVOKEINTERFACE(gitr, 1)); 126 } 127 } 128} 129