001 /*
002 * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026
027 package sun.tools.javap;
028
029 import java.util.*;
030 import java.io.*;
031
032 import static sun.tools.javap.RuntimeConstants.*;
033
034 /* represents one entry of StackMapTable attribute
035 */
036 class StackMapTableData {
037 final int frameType;
038 int offsetDelta;
039
040 StackMapTableData(int frameType) {
041 this.frameType = frameType;
042 }
043
044 void print(JavapPrinter p) {
045 p.out.print(" frame_type = " + frameType);
046 }
047
048 static class SameFrame extends StackMapTableData {
049 SameFrame(int frameType, int offsetDelta) {
050 super(frameType);
051 this.offsetDelta = offsetDelta;
052 }
053 void print(JavapPrinter p) {
054 super.print(p);
055 if (frameType < SAME_FRAME_BOUND) {
056 p.out.println(" /* same */");
057 } else {
058 p.out.println(" /* same_frame_extended */");
059 p.out.println(" offset_delta = " + offsetDelta);
060 }
061 }
062 }
063
064 static class SameLocals1StackItem extends StackMapTableData {
065 final int[] stack;
066 SameLocals1StackItem(int frameType, int offsetDelta, int[] stack) {
067 super(frameType);
068 this.offsetDelta = offsetDelta;
069 this.stack = stack;
070 }
071 void print(JavapPrinter p) {
072 super.print(p);
073 if (frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
074 p.out.println(" /* same_locals_1_stack_item_frame_extended */");
075 p.out.println(" offset_delta = " + offsetDelta);
076 } else {
077 p.out.println(" /* same_locals_1_stack_item */");
078 }
079 p.printMap(" stack = [", stack);
080 }
081 }
082
083 static class ChopFrame extends StackMapTableData {
084 ChopFrame(int frameType, int offsetDelta) {
085 super(frameType);
086 this.offsetDelta = offsetDelta;
087 }
088 void print(JavapPrinter p) {
089 super.print(p);
090 p.out.println(" /* chop */");
091 p.out.println(" offset_delta = " + offsetDelta);
092 }
093 }
094
095 static class AppendFrame extends StackMapTableData {
096 final int[] locals;
097 AppendFrame(int frameType, int offsetDelta, int[] locals) {
098 super(frameType);
099 this.offsetDelta = offsetDelta;
100 this.locals = locals;
101 }
102 void print(JavapPrinter p) {
103 super.print(p);
104 p.out.println(" /* append */");
105 p.out.println(" offset_delta = " + offsetDelta);
106 p.printMap(" locals = [", locals);
107 }
108 }
109
110 static class FullFrame extends StackMapTableData {
111 final int[] locals;
112 final int[] stack;
113 FullFrame(int offsetDelta, int[] locals, int[] stack) {
114 super(FULL_FRAME);
115 this.offsetDelta = offsetDelta;
116 this.locals = locals;
117 this.stack = stack;
118 }
119 void print(JavapPrinter p) {
120 super.print(p);
121 p.out.println(" /* full_frame */");
122 p.out.println(" offset_delta = " + offsetDelta);
123 p.printMap(" locals = [", locals);
124 p.printMap(" stack = [", stack);
125 }
126 }
127
128 static StackMapTableData getInstance(DataInputStream in, MethodData method)
129 throws IOException {
130 int frameType = in.readUnsignedByte();
131
132 if (frameType < SAME_FRAME_BOUND) {
133 // same_frame
134 return new SameFrame(frameType, frameType);
135 } else if (SAME_FRAME_BOUND <= frameType && frameType < SAME_LOCALS_1_STACK_ITEM_BOUND) {
136 // same_locals_1_stack_item_frame
137 // read additional single stack element
138 return new SameLocals1StackItem(frameType,
139 (frameType - SAME_FRAME_BOUND),
140 StackMapData.readTypeArray(in, 1, method));
141 } else if (frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
142 // same_locals_1_stack_item_extended
143 return new SameLocals1StackItem(frameType,
144 in.readUnsignedShort(),
145 StackMapData.readTypeArray(in, 1, method));
146 } else if (SAME_LOCALS_1_STACK_ITEM_EXTENDED < frameType && frameType < SAME_FRAME_EXTENDED) {
147 // chop_frame or same_frame_extended
148 return new ChopFrame(frameType, in.readUnsignedShort());
149 } else if (frameType == SAME_FRAME_EXTENDED) {
150 // chop_frame or same_frame_extended
151 return new SameFrame(frameType, in.readUnsignedShort());
152 } else if (SAME_FRAME_EXTENDED < frameType && frameType < FULL_FRAME) {
153 // append_frame
154 return new AppendFrame(frameType, in.readUnsignedShort(),
155 StackMapData.readTypeArray(in, frameType - SAME_FRAME_EXTENDED, method));
156 } else if (frameType == FULL_FRAME) {
157 // full_frame
158 int offsetDelta = in.readUnsignedShort();
159 int locals_size = in.readUnsignedShort();
160 int[] locals = StackMapData.readTypeArray(in, locals_size, method);
161 int stack_size = in.readUnsignedShort();
162 int[] stack = StackMapData.readTypeArray(in, stack_size, method);
163 return new FullFrame(offsetDelta, locals, stack);
164 } else {
165 throw new ClassFormatError("unrecognized frame_type in StackMapTable");
166 }
167 }
168 }