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
22 package com.sun.org.apache.xalan.internal.xsltc.compiler;
23
24 import com.sun.org.apache.bcel.internal.generic.BranchHandle;
25 import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
26 import com.sun.org.apache.bcel.internal.generic.GOTO;
27 import com.sun.org.apache.bcel.internal.generic.IFEQ;
28 import com.sun.org.apache.bcel.internal.generic.IF_ICMPEQ;
29 import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
30 import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
31 import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
32 import com.sun.org.apache.bcel.internal.generic.InstructionList;
33 import com.sun.org.apache.bcel.internal.generic.PUSH;
34 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
35 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
36 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
37 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
38 import com.sun.org.apache.xml.internal.dtm.Axis;
39 import com.sun.org.apache.xml.internal.dtm.DTM;
40
41 /**
42 * @author Morten Jorgensen
43 */
44 final class ProcessingInstructionPattern extends StepPattern {
45
46 private String _name = null;
47 private boolean _typeChecked = false;
48
49 /**
50 * Handles calls with no parameter (current node is implicit parameter).
51 */
52 public ProcessingInstructionPattern(String name) {
53 super(Axis.CHILD, DTM.PROCESSING_INSTRUCTION_NODE, null);
54 _name = name;
55 //if (_name.equals("*")) _typeChecked = true; no wildcard allowed!
56 }
57
58 /**
59 *
60 */
61 public double getDefaultPriority() {
62 return (_name != null) ? 0.0 : -0.5;
63 }
64 public String toString() {
65 if (_predicates == null)
66 return "processing-instruction("+_name+")";
67 else
68 return "processing-instruction("+_name+")"+_predicates;
69 }
70
71 public void reduceKernelPattern() {
72 _typeChecked = true;
73 }
74
75 public boolean isWildcard() {
76 return false;
77 }
78
79 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
80 if (hasPredicates()) {
81 // Type check all the predicates (e -> position() = e)
82 final int n = _predicates.size();
83 for (int i = 0; i < n; i++) {
84 final Predicate pred = (Predicate)_predicates.elementAt(i);
85 pred.typeCheck(stable);
86 }
87 }
88 return Type.NodeSet;
89 }
90
91 public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
92 final ConstantPoolGen cpg = classGen.getConstantPool();
93 final InstructionList il = methodGen.getInstructionList();
94
95 // context node is on the stack
96 int gname = cpg.addInterfaceMethodref(DOM_INTF,
97 "getNodeName",
98 "(I)Ljava/lang/String;");
99 int cmp = cpg.addMethodref(STRING_CLASS,
100 "equals", "(Ljava/lang/Object;)Z");
101
102 // Push current node on the stack
103 il.append(methodGen.loadCurrentNode());
104 il.append(SWAP);
105
106 // Overwrite current node with matching node
107 il.append(methodGen.storeCurrentNode());
108
109 // If pattern not reduced then check kernel
110 if (!_typeChecked) {
111 il.append(methodGen.loadCurrentNode());
112 final int getType = cpg.addInterfaceMethodref(DOM_INTF,
113 "getExpandedTypeID",
114 "(I)I");
115 il.append(methodGen.loadDOM());
116 il.append(methodGen.loadCurrentNode());
117 il.append(new INVOKEINTERFACE(getType, 2));
118 il.append(new PUSH(cpg, DTM.PROCESSING_INSTRUCTION_NODE));
119 _falseList.add(il.append(new IF_ICMPEQ(null)));
120 }
121
122 // Load the requested processing instruction name
123 il.append(new PUSH(cpg, _name));
124 // Load the current processing instruction's name
125 il.append(methodGen.loadDOM());
126 il.append(methodGen.loadCurrentNode());
127 il.append(new INVOKEINTERFACE(gname, 2));
128 // Compare the two strings
129 il.append(new INVOKEVIRTUAL(cmp));
130 _falseList.add(il.append(new IFEQ(null)));
131
132 // Compile the expressions within the predicates
133 if (hasPredicates()) {
134 final int n = _predicates.size();
135 for (int i = 0; i < n; i++) {
136 Predicate pred = (Predicate)_predicates.elementAt(i);
137 Expression exp = pred.getExpr();
138 exp.translateDesynthesized(classGen, methodGen);
139 _trueList.append(exp._trueList);
140 _falseList.append(exp._falseList);
141 }
142 }
143
144 // Backpatch true list and restore current iterator/node
145 InstructionHandle restore;
146 restore = il.append(methodGen.storeCurrentNode());
147 backPatchTrueList(restore);
148 BranchHandle skipFalse = il.append(new GOTO(null));
149
150 // Backpatch false list and restore current iterator/node
151 restore = il.append(methodGen.storeCurrentNode());
152 backPatchFalseList(restore);
153 _falseList.add(il.append(new GOTO(null)));
154
155 // True list falls through
156 skipFalse.setTarget(il.append(NOP));
157 }
158 }