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.util;
23
24 import com.sun.org.apache.bcel.internal.generic.ALOAD;
25 import com.sun.org.apache.bcel.internal.generic.ASTORE;
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;
29 import com.sun.org.apache.bcel.internal.generic.IFEQ;
30 import com.sun.org.apache.bcel.internal.generic.IFNONNULL;
31 import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
32 import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
33 import com.sun.org.apache.bcel.internal.generic.Instruction;
34 import com.sun.org.apache.bcel.internal.generic.InstructionList;
35 import com.sun.org.apache.bcel.internal.generic.PUSH;
36 import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
37 import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;
38
39 /**
40 * @author Jacek Ambroziak
41 * @author Santiago Pericas-Geertsen
42 */
43 public class StringType extends Type {
44 protected StringType() {}
45
46 public String toString() {
47 return "string";
48 }
49
50 public boolean identicalTo(Type other) {
51 return this == other;
52 }
53
54 public String toSignature() {
55 return "Ljava/lang/String;";
56 }
57
58 public boolean isSimple() {
59 return true;
60 }
61
62 public com.sun.org.apache.bcel.internal.generic.Type toJCType() {
63 return com.sun.org.apache.bcel.internal.generic.Type.STRING;
64 }
65
66 /**
67 * Translates a string into an object of internal type <code>type</code>.
68 * The translation to int is undefined since strings are always converted
69 * to reals in arithmetic expressions.
70 *
71 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
72 */
73 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
74 Type type) {
75 if (type == Type.Boolean) {
76 translateTo(classGen, methodGen, (BooleanType) type);
77 }
78 else if (type == Type.Real) {
79 translateTo(classGen, methodGen, (RealType) type);
80 }
81 else if (type == Type.Reference) {
82 translateTo(classGen, methodGen, (ReferenceType) type);
83 }
84 else if (type == Type.ObjectString) {
85 // NOP -> same representation
86 }
87 else {
88 ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
89 toString(), type.toString());
90 classGen.getParser().reportError(Constants.FATAL, err);
91 }
92 }
93
94 /**
95 * Translates a string into a synthesized boolean.
96 *
97 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
98 */
99 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
100 BooleanType type) {
101 final InstructionList il = methodGen.getInstructionList();
102 FlowList falsel = translateToDesynthesized(classGen, methodGen, type);
103 il.append(ICONST_1);
104 final BranchHandle truec = il.append(new GOTO(null));
105 falsel.backPatch(il.append(ICONST_0));
106 truec.setTarget(il.append(NOP));
107 }
108
109 /**
110 * Translates a string into a real by calling stringToReal() from the
111 * basis library.
112 *
113 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
114 */
115 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
116 RealType type) {
117 final ConstantPoolGen cpg = classGen.getConstantPool();
118 final InstructionList il = methodGen.getInstructionList();
119 il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,
120 STRING_TO_REAL,
121 STRING_TO_REAL_SIG)));
122 }
123
124 /**
125 * Translates a string into a non-synthesized boolean. It does not push a
126 * 0 or a 1 but instead returns branchhandle list to be appended to the
127 * false list.
128 *
129 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized
130 */
131 public FlowList translateToDesynthesized(ClassGenerator classGen,
132 MethodGenerator methodGen,
133 BooleanType type) {
134 final ConstantPoolGen cpg = classGen.getConstantPool();
135 final InstructionList il = methodGen.getInstructionList();
136
137 il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
138 "length", "()I")));
139 return new FlowList(il.append(new IFEQ(null)));
140 }
141
142 /**
143 * Expects a string on the stack and pushes a boxed string.
144 * Strings are already boxed so the translation is just a NOP.
145 *
146 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
147 */
148 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
149 ReferenceType type) {
150 methodGen.getInstructionList().append(NOP);
151 }
152
153 /**
154 * Translates a internal string into an external (Java) string.
155 *
156 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateFrom
157 */
158 public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
159 Class clazz)
160 {
161 // Is String <: clazz? I.e. clazz in { String, Object }
162 if (clazz.isAssignableFrom(java.lang.String.class)) {
163 methodGen.getInstructionList().append(NOP);
164 }
165 else {
166 ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
167 toString(), clazz.getName());
168 classGen.getParser().reportError(Constants.FATAL, err);
169 }
170 }
171
172 /**
173 * Translates an external (primitive) Java type into a string.
174 *
175 * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateFrom
176 */
177 public void translateFrom(ClassGenerator classGen,
178 MethodGenerator methodGen, Class clazz)
179 {
180 final ConstantPoolGen cpg = classGen.getConstantPool();
181 final InstructionList il = methodGen.getInstructionList();
182
183 if (clazz.getName().equals("java.lang.String")) {
184 // same internal representation, convert null to ""
185 il.append(DUP);
186 final BranchHandle ifNonNull = il.append(new IFNONNULL(null));
187 il.append(POP);
188 il.append(new PUSH(cpg, ""));
189 ifNonNull.setTarget(il.append(NOP));
190 }
191 else {
192 ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
193 toString(), clazz.getName());
194 classGen.getParser().reportError(Constants.FATAL, err);
195 }
196 }
197
198 /**
199 * Translates an object of this type to its boxed representation.
200 */
201 public void translateBox(ClassGenerator classGen,
202 MethodGenerator methodGen) {
203 translateTo(classGen, methodGen, Type.Reference);
204 }
205
206 /**
207 * Translates an object of this type to its unboxed representation.
208 */
209 public void translateUnBox(ClassGenerator classGen,
210 MethodGenerator methodGen) {
211 methodGen.getInstructionList().append(NOP);
212 }
213
214 /**
215 * Returns the class name of an internal type's external representation.
216 */
217 public String getClassName() {
218 return(STRING_CLASS);
219 }
220
221
222 public Instruction LOAD(int slot) {
223 return new ALOAD(slot);
224 }
225
226 public Instruction STORE(int slot) {
227 return new ASTORE(slot);
228 }
229 }