1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.bcel.generic;
18
19 import org.apache.bcel.Const;
20 import org.apache.bcel.classfile.ConstantCP;
21 import org.apache.bcel.classfile.ConstantNameAndType;
22 import org.apache.bcel.classfile.ConstantPool;
23 import org.apache.bcel.classfile.ConstantUtf8;
24 import org.apache.bcel.classfile.Utility;
25
26 /**
27 * Super class for InvokeInstruction and FieldInstruction, since they have some methods in common!
28 */
29 public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
30
31 /**
32 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
33 */
34 FieldOrMethod() {
35 // no init
36 }
37
38 /**
39 * @param index to constant pool
40 */
41 protected FieldOrMethod(final short opcode, final int index) {
42 super(opcode, index);
43 }
44
45 /**
46 * @return name of the referenced class/interface
47 * @deprecated If the instruction references an array class, this method will return "java.lang.Object". For code
48 * generated by Java 1.5, this answer is sometimes wrong (e.g., if the "clone()" method is called on an
49 * array). A better idea is to use the {@link #getReferenceType(ConstantPoolGen)} method, which correctly
50 * distinguishes between class types and array types.
51 */
52 @Deprecated
53 public String getClassName(final ConstantPoolGen cpg) {
54 final ConstantPool cp = cpg.getConstantPool();
55 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
56 final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
57 if (className.startsWith("[")) {
58 // Turn array classes into java.lang.Object.
59 return "java.lang.Object";
60 }
61 return Utility.pathToPackage(className);
62 }
63
64 /**
65 * @return type of the referenced class/interface
66 * @deprecated If the instruction references an array class, the ObjectType returned will be invalid. Use
67 * getReferenceType() instead.
68 */
69 @Deprecated
70 public ObjectType getClassType(final ConstantPoolGen cpg) {
71 return ObjectType.getInstance(getClassName(cpg));
72 }
73
74 /**
75 * Gets the ObjectType of the method return or field.
76 *
77 * @return type of the referenced class/interface
78 * @throws ClassGenException when the field is (or method returns) an array,
79 */
80 @Override
81 public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
82 final ReferenceType rt = getReferenceType(cpg);
83 if (rt instanceof ObjectType) {
84 return (ObjectType) rt;
85 }
86 if (rt instanceof ArrayType) {
87 return Type.OBJECT;
88 }
89 throw new ClassGenException(rt.getClass().getCanonicalName() + " " + rt.getSignature() + " does not represent an ObjectType");
90 }
91
92 /**
93 * @return name of referenced method/field.
94 */
95 public String getName(final ConstantPoolGen cpg) {
96 final ConstantPool cp = cpg.getConstantPool();
97 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
98 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
99 return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
100 }
101
102 /**
103 * Gets the reference type representing the class, interface, or array class referenced by the instruction.
104 *
105 * @param cpg the ConstantPoolGen used to create the instruction
106 * @return an ObjectType (if the referenced class type is a class or interface), or an ArrayType (if the referenced
107 * class type is an array class)
108 */
109 public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
110 final ConstantPool cp = cpg.getConstantPool();
111 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
112 String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
113 if (className.startsWith("[")) {
114 return (ArrayType) Type.getType(className);
115 }
116 className = Utility.pathToPackage(className);
117 return ObjectType.getInstance(className);
118 }
119
120 /**
121 * @return signature of referenced method/field.
122 */
123 public String getSignature(final ConstantPoolGen cpg) {
124 final ConstantPool cp = cpg.getConstantPool();
125 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
126 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
127 return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
128 }
129 }