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: BooleanType.java 468649 2006-10-28 07:00:55Z minchau $
020 */
021
022 package org.apache.xalan.xsltc.compiler.util;
023
024 import org.apache.bcel.generic.BranchHandle;
025 import org.apache.bcel.generic.BranchInstruction;
026 import org.apache.bcel.generic.CHECKCAST;
027 import org.apache.bcel.generic.ConstantPoolGen;
028 import org.apache.bcel.generic.GOTO;
029 import org.apache.bcel.generic.IFEQ;
030 import org.apache.bcel.generic.IFGE;
031 import org.apache.bcel.generic.IFGT;
032 import org.apache.bcel.generic.IFLE;
033 import org.apache.bcel.generic.IFLT;
034 import org.apache.bcel.generic.IF_ICMPGE;
035 import org.apache.bcel.generic.IF_ICMPGT;
036 import org.apache.bcel.generic.IF_ICMPLE;
037 import org.apache.bcel.generic.IF_ICMPLT;
038 import org.apache.bcel.generic.ILOAD;
039 import org.apache.bcel.generic.INVOKESPECIAL;
040 import org.apache.bcel.generic.INVOKEVIRTUAL;
041 import org.apache.bcel.generic.ISTORE;
042 import org.apache.bcel.generic.Instruction;
043 import org.apache.bcel.generic.InstructionList;
044 import org.apache.bcel.generic.NEW;
045 import org.apache.bcel.generic.PUSH;
046 import org.apache.xalan.xsltc.compiler.Constants;
047
048 /**
049 * @author Jacek Ambroziak
050 * @author Santiago Pericas-Geertsen
051 */
052 public final class BooleanType extends Type {
053 protected BooleanType() {}
054
055 public String toString() {
056 return "boolean";
057 }
058
059 public boolean identicalTo(Type other) {
060 return this == other;
061 }
062
063 public String toSignature() {
064 return "Z";
065 }
066
067 public boolean isSimple() {
068 return true;
069 }
070
071 public org.apache.bcel.generic.Type toJCType() {
072 return org.apache.bcel.generic.Type.BOOLEAN;
073 }
074
075 /**
076 * Translates a real into an object of internal type <code>type</code>. The
077 * translation to int is undefined since booleans are always converted to
078 * reals in arithmetic expressions.
079 *
080 * @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
081 */
082 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
083 Type type) {
084 if (type == Type.String) {
085 translateTo(classGen, methodGen, (StringType) type);
086 }
087 else if (type == Type.Real) {
088 translateTo(classGen, methodGen, (RealType) type);
089 }
090 else if (type == Type.Reference) {
091 translateTo(classGen, methodGen, (ReferenceType) type);
092 }
093 else {
094 ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
095 toString(), type.toString());
096 classGen.getParser().reportError(Constants.FATAL, err);
097 }
098 }
099
100 /**
101 * Expects a boolean on the stack and pushes a string. If the value on the
102 * stack is zero, then the string 'false' is pushed. Otherwise, the string
103 * 'true' is pushed.
104 *
105 * @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
106 */
107 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
108 StringType type) {
109 final ConstantPoolGen cpg = classGen.getConstantPool();
110 final InstructionList il = methodGen.getInstructionList();
111 final BranchHandle falsec = il.append(new IFEQ(null));
112 il.append(new PUSH(cpg, "true"));
113 final BranchHandle truec = il.append(new GOTO(null));
114 falsec.setTarget(il.append(new PUSH(cpg, "false")));
115 truec.setTarget(il.append(NOP));
116 }
117
118 /**
119 * Expects a boolean on the stack and pushes a real. The value "true" is
120 * converted to 1.0 and the value "false" to 0.0.
121 *
122 * @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
123 */
124 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
125 RealType type) {
126 methodGen.getInstructionList().append(I2D);
127 }
128
129 /**
130 * Expects a boolean on the stack and pushes a boxed boolean.
131 * Boxed booleans are represented by an instance of
132 * <code>java.lang.Boolean</code>.
133 *
134 * @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
135 */
136 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
137 ReferenceType type) {
138 final ConstantPoolGen cpg = classGen.getConstantPool();
139 final InstructionList il = methodGen.getInstructionList();
140 il.append(new NEW(cpg.addClass(BOOLEAN_CLASS)));
141 il.append(DUP_X1);
142 il.append(SWAP);
143 il.append(new INVOKESPECIAL(cpg.addMethodref(BOOLEAN_CLASS,
144 "<init>",
145 "(Z)V")));
146 }
147
148 /**
149 * Translates an internal boolean into an external (Java) boolean.
150 */
151 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
152 Class clazz) {
153 if (clazz == java.lang.Boolean.TYPE) {
154 methodGen.getInstructionList().append(NOP);
155 }
156 // Is Boolean <: clazz? I.e. clazz in { Boolean, Object }
157 else if (clazz.isAssignableFrom(java.lang.Boolean.class)) {
158 translateTo(classGen, methodGen, Type.Reference);
159 }
160 else {
161 ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
162 toString(), clazz.getName());
163 classGen.getParser().reportError(Constants.FATAL, err);
164 }
165 }
166
167 /**
168 * Translates an external (Java) boolean into internal boolean.
169 */
170 public void translateFrom(ClassGenerator classGen, MethodGenerator methodGen,
171 Class clazz) {
172 translateTo(classGen, methodGen, clazz);
173 }
174
175 /**
176 * Translates an object of this type to its boxed representation.
177 */
178 public void translateBox(ClassGenerator classGen,
179 MethodGenerator methodGen) {
180 translateTo(classGen, methodGen, Type.Reference);
181 }
182
183 /**
184 * Translates an object of this type to its unboxed representation.
185 */
186 public void translateUnBox(ClassGenerator classGen,
187 MethodGenerator methodGen) {
188 final ConstantPoolGen cpg = classGen.getConstantPool();
189 final InstructionList il = methodGen.getInstructionList();
190 il.append(new CHECKCAST(cpg.addClass(BOOLEAN_CLASS)));
191 il.append(new INVOKEVIRTUAL(cpg.addMethodref(BOOLEAN_CLASS,
192 BOOLEAN_VALUE,
193 BOOLEAN_VALUE_SIG)));
194 }
195
196 public Instruction LOAD(int slot) {
197 return new ILOAD(slot);
198 }
199
200 public Instruction STORE(int slot) {
201 return new ISTORE(slot);
202 }
203
204 public BranchInstruction GT(boolean tozero) {
205 return tozero ? (BranchInstruction) new IFGT(null) :
206 (BranchInstruction) new IF_ICMPGT(null);
207 }
208
209 public BranchInstruction GE(boolean tozero) {
210 return tozero ? (BranchInstruction) new IFGE(null) :
211 (BranchInstruction) new IF_ICMPGE(null);
212 }
213
214 public BranchInstruction LT(boolean tozero) {
215 return tozero ? (BranchInstruction) new IFLT(null) :
216 (BranchInstruction) new IF_ICMPLT(null);
217 }
218
219 public BranchInstruction LE(boolean tozero) {
220 return tozero ? (BranchInstruction) new IFLE(null) :
221 (BranchInstruction) new IF_ICMPLE(null);
222 }
223 }