1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.generic;
20
21 import org.apache.bcel.Const;
22 import org.apache.bcel.classfile.ConstantCP;
23 import org.apache.bcel.classfile.ConstantNameAndType;
24 import org.apache.bcel.classfile.ConstantPool;
25 import org.apache.bcel.classfile.ConstantUtf8;
26 import org.apache.bcel.classfile.Utility;
27
28 /**
29 * Super class for InvokeInstruction and FieldInstruction, since they have some methods in common!
30 */
31 public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
32
33 /**
34 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
35 */
36 FieldOrMethod() {
37 // no init
38 }
39
40 /**
41 * Constructs a FieldOrMethod.
42 *
43 * @param opcode the opcode.
44 * @param index to constant pool.
45 */
46 protected FieldOrMethod(final short opcode, final int index) {
47 super(opcode, index);
48 }
49
50 /**
51 * Gets the name of the referenced class/interface.
52 *
53 * @param cpg the constant pool generator.
54 * @return name of the referenced class/interface.
55 * @deprecated If the instruction references an array class, this method will return "java.lang.Object". For code
56 * generated by Java 1.5, this answer is sometimes wrong (for example, if the "clone()" method is called on an
57 * array). A better idea is to use the {@link #getReferenceType(ConstantPoolGen)} method, which correctly
58 * distinguishes between class types and array types.
59 */
60 @Deprecated
61 public String getClassName(final ConstantPoolGen cpg) {
62 final ConstantPool cp = cpg.getConstantPool();
63 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
64 final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
65 if (className.startsWith("[")) {
66 // Turn array classes into java.lang.Object.
67 return "java.lang.Object";
68 }
69 return Utility.pathToPackage(className);
70 }
71
72 /**
73 * Gets the type of the referenced class/interface.
74 *
75 * @param cpg the constant pool generator.
76 * @return type of the referenced class/interface.
77 * @deprecated If the instruction references an array class, the ObjectType returned will be invalid. Use
78 * getReferenceType() instead.
79 */
80 @Deprecated
81 public ObjectType getClassType(final ConstantPoolGen cpg) {
82 return ObjectType.getInstance(getClassName(cpg));
83 }
84
85 /**
86 * Gets the ObjectType of the method return or field.
87 *
88 * @param cpg the constant pool generator.
89 * @return type of the referenced class/interface.
90 * @throws ClassGenException when the field is (or method returns) an array.
91 */
92 @Override
93 public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
94 final ReferenceType rt = getReferenceType(cpg);
95 if (rt instanceof ObjectType) {
96 return (ObjectType) rt;
97 }
98 if (rt instanceof ArrayType) {
99 return Type.OBJECT;
100 }
101 throw new ClassGenException(rt.getClass().getCanonicalName() + " " + rt.getSignature() + " does not represent an ObjectType");
102 }
103
104 /**
105 * Gets the name of referenced method or field.
106 *
107 * @param cpg the constant pool generator.
108 * @return name of referenced method/field.
109 */
110 public String getName(final ConstantPoolGen cpg) {
111 final ConstantPool cp = cpg.getConstantPool();
112 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
113 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
114 return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
115 }
116
117 /**
118 * Gets the reference type representing the class, interface, or array class referenced by the instruction.
119 *
120 * @param cpg the ConstantPoolGen used to create the instruction.
121 * @return an ObjectType (if the referenced class type is a class or interface), or an ArrayType (if the referenced
122 * class type is an array class)
123 */
124 public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
125 final ConstantPool cp = cpg.getConstantPool();
126 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
127 String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
128 if (className.startsWith("[")) {
129 return (ArrayType) Type.getType(className);
130 }
131 className = Utility.pathToPackage(className);
132 return ObjectType.getInstance(className);
133 }
134
135 /**
136 * Gets the signature of referenced method or field.
137 *
138 * @param cpg the constant pool generator.
139 * @return signature of referenced method/field.
140 */
141 public String getSignature(final ConstantPoolGen cpg) {
142 final ConstantPool cp = cpg.getConstantPool();
143 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
144 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
145 return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
146 }
147 }