1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Copyright 2001-2004 The Apache Software Foundation.
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20 /*
21 * $Id: AbsolutePathPattern.java,v 1.2.4.1 2005/09/01 09:17:09 pvedula Exp $
22 */
23
24 package com.sun.org.apache.xalan.internal.xsltc.compiler;
25
26 import com.sun.org.apache.bcel.internal.generic.BranchHandle;
27 import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
28 import com.sun.org.apache.bcel.internal.generic.GOTO_W;
29 import com.sun.org.apache.bcel.internal.generic.IF_ICMPEQ;
30 import com.sun.org.apache.bcel.internal.generic.ILOAD;
31 import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
32 import com.sun.org.apache.bcel.internal.generic.ISTORE;
33 import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
34 import com.sun.org.apache.bcel.internal.generic.InstructionList;
35 import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
36 import com.sun.org.apache.bcel.internal.generic.PUSH;
37 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
38 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
39 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
40 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
41 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
42 import com.sun.org.apache.xml.internal.dtm.DTM;
43
44 /**
45 * @author Jacek Ambroziak
46 * @author Santiago Pericas-Geertsen
47 */
48 final class AbsolutePathPattern extends LocationPathPattern {
49 private final RelativePathPattern _left; // may be null
50
51 public AbsolutePathPattern(RelativePathPattern left) {
52 _left = left;
53 if (left != null) {
54 left.setParent(this);
55 }
56 }
57
58 public void setParser(Parser parser) {
59 super.setParser(parser);
60 if (_left != null)
61 _left.setParser(parser);
62 }
63
64 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
65 return _left == null ? Type.Root : _left.typeCheck(stable);
66 }
67
68 public boolean isWildcard() {
69 return false;
70 }
71
72 public StepPattern getKernelPattern() {
73 return _left != null ? _left.getKernelPattern() : null;
74 }
75
76 public void reduceKernelPattern() {
77 _left.reduceKernelPattern();
78 }
79
80 public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
81 final ConstantPoolGen cpg = classGen.getConstantPool();
82 final InstructionList il = methodGen.getInstructionList();
83
84 if (_left != null) {
85 if (_left instanceof StepPattern) {
86 final LocalVariableGen local =
87 // absolute path pattern temporary
88 methodGen.addLocalVariable2("apptmp",
89 Util.getJCRefType(NODE_SIG),
90 null);
91 il.append(DUP);
92 local.setStart(il.append(new ISTORE(local.getIndex())));
93 _left.translate(classGen, methodGen);
94 il.append(methodGen.loadDOM());
95 local.setEnd(il.append(new ILOAD(local.getIndex())));
96 methodGen.removeLocalVariable(local);
97 }
98 else {
99 _left.translate(classGen, methodGen);
100 }
101 }
102
103 final int getParent = cpg.addInterfaceMethodref(DOM_INTF,
104 GET_PARENT,
105 GET_PARENT_SIG);
106 final int getType = cpg.addInterfaceMethodref(DOM_INTF,
107 "getExpandedTypeID",
108 "(I)I");
109
110 InstructionHandle begin = il.append(methodGen.loadDOM());
111 il.append(SWAP);
112 il.append(new INVOKEINTERFACE(getParent, 2));
113 if (_left instanceof AncestorPattern) {
114 il.append(methodGen.loadDOM());
115 il.append(SWAP);
116 }
117 il.append(new INVOKEINTERFACE(getType, 2));
118 il.append(new PUSH(cpg, DTM.DOCUMENT_NODE));
119
120 final BranchHandle skip = il.append(new IF_ICMPEQ(null));
121 _falseList.add(il.append(new GOTO_W(null)));
122 skip.setTarget(il.append(NOP));
123
124 if (_left != null) {
125 _left.backPatchTrueList(begin);
126
127 /*
128 * If _left is an ancestor pattern, backpatch this pattern's false
129 * list to the loop that searches for more ancestors.
130 */
131 if (_left instanceof AncestorPattern) {
132 final AncestorPattern ancestor = (AncestorPattern) _left;
133 _falseList.backPatch(ancestor.getLoopHandle()); // clears list
134 }
135 _falseList.append(_left._falseList);
136 }
137 }
138
139 public String toString() {
140 return "absolutePathPattern(" + (_left != null ? _left.toString() : ")");
141 }
142 }