001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 */
018 package org.apache.bcel.generic;
019
020 import java.util.StringTokenizer;
021 import org.apache.bcel.Constants;
022 import org.apache.bcel.classfile.Constant;
023 import org.apache.bcel.classfile.ConstantPool;
024
025 /**
026 * Super class for the INVOKExxx family of instructions.
027 *
028 * @version $Id: InvokeInstruction.java 1152072 2011-07-29 01:54:05Z dbrosius $
029 * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
030 */
031 public abstract class InvokeInstruction extends FieldOrMethod implements ExceptionThrower,
032 StackConsumer, StackProducer {
033
034 private static final long serialVersionUID = 6089031137856650442L;
035
036
037 /**
038 * Empty constructor needed for the Class.newInstance() statement in
039 * Instruction.readInstruction(). Not to be used otherwise.
040 */
041 InvokeInstruction() {
042 }
043
044
045 /**
046 * @param index to constant pool
047 */
048 protected InvokeInstruction(short opcode, int index) {
049 super(opcode, index);
050 }
051
052
053 /**
054 * @return mnemonic for instruction with symbolic references resolved
055 */
056 @Override
057 public String toString( ConstantPool cp ) {
058 Constant c = cp.getConstant(index);
059 StringTokenizer tok = new StringTokenizer(cp.constantToString(c));
060 return Constants.OPCODE_NAMES[opcode] + " " + tok.nextToken().replace('.', '/')
061 + tok.nextToken();
062 }
063
064
065 /**
066 * Also works for instructions whose stack effect depends on the
067 * constant pool entry they reference.
068 * @return Number of words consumed from stack by this instruction
069 */
070 @Override
071 public int consumeStack( ConstantPoolGen cpg ) {
072 int sum;
073 if (opcode == Constants.INVOKESTATIC) {
074 sum = 0;
075 } else {
076 sum = 1; // this reference
077 }
078
079 String signature = getSignature(cpg);
080 sum += Type.getArgumentTypesSize(signature);
081 return sum;
082 }
083
084
085 /**
086 * Also works for instructions whose stack effect depends on the
087 * constant pool entry they reference.
088 * @return Number of words produced onto stack by this instruction
089 */
090 @Override
091 public int produceStack( ConstantPoolGen cpg ) {
092 String signature = getSignature(cpg);
093 return Type.getReturnTypeSize(signature);
094 }
095
096
097 /** @return return type of referenced method.
098 */
099 @Override
100 public Type getType( ConstantPoolGen cpg ) {
101 return getReturnType(cpg);
102 }
103
104
105 /** @return name of referenced method.
106 */
107 public String getMethodName( ConstantPoolGen cpg ) {
108 return getName(cpg);
109 }
110
111
112 /** @return return type of referenced method.
113 */
114 public Type getReturnType( ConstantPoolGen cpg ) {
115 return Type.getReturnType(getSignature(cpg));
116 }
117
118
119 /** @return argument types of referenced method.
120 */
121 public Type[] getArgumentTypes( ConstantPoolGen cpg ) {
122 return Type.getArgumentTypes(getSignature(cpg));
123 }
124 }