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 * @param index to constant pool
42 */
43 protected FieldOrMethod(final short opcode, final int index) {
44 super(opcode, index);
45 }
46
47 /**
48 * @return name of the referenced class/interface
49 * @deprecated If the instruction references an array class, this method will return "java.lang.Object". For code
50 * generated by Java 1.5, this answer is sometimes wrong (for example, if the "clone()" method is called on an
51 * array). A better idea is to use the {@link #getReferenceType(ConstantPoolGen)} method, which correctly
52 * distinguishes between class types and array types.
53 */
54 @Deprecated
55 public String getClassName(final ConstantPoolGen cpg) {
56 final ConstantPool cp = cpg.getConstantPool();
57 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
58 final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
59 if (className.startsWith("[")) {
60 // Turn array classes into java.lang.Object.
61 return "java.lang.Object";
62 }
63 return Utility.pathToPackage(className);
64 }
65
66 /**
67 * @return type of the referenced class/interface
68 * @deprecated If the instruction references an array class, the ObjectType returned will be invalid. Use
69 * getReferenceType() instead.
70 */
71 @Deprecated
72 public ObjectType getClassType(final ConstantPoolGen cpg) {
73 return ObjectType.getInstance(getClassName(cpg));
74 }
75
76 /**
77 * Gets the ObjectType of the method return or field.
78 *
79 * @return type of the referenced class/interface
80 * @throws ClassGenException when the field is (or method returns) an array,
81 */
82 @Override
83 public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
84 final ReferenceType rt = getReferenceType(cpg);
85 if (rt instanceof ObjectType) {
86 return (ObjectType) rt;
87 }
88 if (rt instanceof ArrayType) {
89 return Type.OBJECT;
90 }
91 throw new ClassGenException(rt.getClass().getCanonicalName() + " " + rt.getSignature() + " does not represent an ObjectType");
92 }
93
94 /**
95 * @return name of referenced method/field.
96 */
97 public String getName(final ConstantPoolGen cpg) {
98 final ConstantPool cp = cpg.getConstantPool();
99 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
100 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
101 return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
102 }
103
104 /**
105 * Gets the reference type representing the class, interface, or array class referenced by the instruction.
106 *
107 * @param cpg the ConstantPoolGen used to create the instruction
108 * @return an ObjectType (if the referenced class type is a class or interface), or an ArrayType (if the referenced
109 * class type is an array class)
110 */
111 public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
112 final ConstantPool cp = cpg.getConstantPool();
113 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
114 String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
115 if (className.startsWith("[")) {
116 return (ArrayType) Type.getType(className);
117 }
118 className = Utility.pathToPackage(className);
119 return ObjectType.getInstance(className);
120 }
121
122 /**
123 * @return signature of referenced method/field.
124 */
125 public String getSignature(final ConstantPoolGen cpg) {
126 final ConstantPool cp = cpg.getConstantPool();
127 final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
128 final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
129 return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
130 }
131 }