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27 package org.apidesign.javap;
31 import static org.apidesign.javap.RuntimeConstants.*;
33 /* represents one entry of StackMapTable attribute
35 abstract class StackMapTableData {
39 StackMapTableData(int frameType) {
40 this.frameType = frameType;
43 abstract void applyTo(TypeArray localTypes, TypeArray stackTypes);
45 protected static String toString(
46 final String frameType,
48 final int[] localTypes,
49 final int[] stackTypes) {
50 final StringBuilder sb = new StringBuilder(frameType);
52 sb.append("(off: +").append(offset);
53 if (localTypes != null) {
54 sb.append(", locals: ");
55 appendTypes(sb, localTypes);
57 if (stackTypes != null) {
58 sb.append(", stack: ");
59 appendTypes(sb, stackTypes);
66 private static void appendTypes(final StringBuilder sb, final int[] types) {
68 if (types.length > 0) {
69 sb.append(TypeArray.typeString(types[0]));
70 for (int i = 1; i < types.length; ++i) {
72 sb.append(TypeArray.typeString(types[i]));
78 static class SameFrame extends StackMapTableData {
79 SameFrame(int frameType, int offsetDelta) {
81 this.offsetDelta = offsetDelta;
85 void applyTo(TypeArray localTypes, TypeArray stackTypes) {
90 public String toString() {
91 return toString("SAME" + ((frameType == SAME_FRAME_EXTENDED)
92 ? "_FRAME_EXTENDED" : ""),
98 static class SameLocals1StackItem extends StackMapTableData {
100 SameLocals1StackItem(int frameType, int offsetDelta, int[] stack) {
102 this.offsetDelta = offsetDelta;
107 void applyTo(TypeArray localTypes, TypeArray stackTypes) {
108 stackTypes.setAll(stack);
112 public String toString() {
114 "SAME_LOCALS_1_STACK_ITEM"
115 + ((frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED)
122 static class ChopFrame extends StackMapTableData {
123 ChopFrame(int frameType, int offsetDelta) {
125 this.offsetDelta = offsetDelta;
129 void applyTo(TypeArray localTypes, TypeArray stackTypes) {
130 localTypes.setSize(localTypes.getSize()
131 - (SAME_FRAME_EXTENDED - frameType));
136 public String toString() {
137 return toString("CHOP", offsetDelta, null, null);
141 static class AppendFrame extends StackMapTableData {
143 AppendFrame(int frameType, int offsetDelta, int[] locals) {
145 this.offsetDelta = offsetDelta;
146 this.locals = locals;
150 void applyTo(TypeArray localTypes, TypeArray stackTypes) {
151 localTypes.addAll(locals);
156 public String toString() {
157 return toString("APPEND", offsetDelta, locals, null);
161 static class FullFrame extends StackMapTableData {
164 FullFrame(int offsetDelta, int[] locals, int[] stack) {
166 this.offsetDelta = offsetDelta;
167 this.locals = locals;
172 void applyTo(TypeArray localTypes, TypeArray stackTypes) {
173 localTypes.setAll(locals);
174 stackTypes.setAll(stack);
178 public String toString() {
179 return toString("FULL", offsetDelta, locals, stack);
183 static StackMapTableData getInstance(DataInputStream in, MethodData method)
185 int frameType = in.readUnsignedByte();
187 if (frameType < SAME_FRAME_BOUND) {
189 return new SameFrame(frameType, frameType);
190 } else if (SAME_FRAME_BOUND <= frameType && frameType < SAME_LOCALS_1_STACK_ITEM_BOUND) {
191 // same_locals_1_stack_item_frame
192 // read additional single stack element
193 return new SameLocals1StackItem(frameType,
194 (frameType - SAME_FRAME_BOUND),
195 StackMapData.readTypeArray(in, 1, method));
196 } else if (frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
197 // same_locals_1_stack_item_extended
198 return new SameLocals1StackItem(frameType,
199 in.readUnsignedShort(),
200 StackMapData.readTypeArray(in, 1, method));
201 } else if (SAME_LOCALS_1_STACK_ITEM_EXTENDED < frameType && frameType < SAME_FRAME_EXTENDED) {
202 // chop_frame or same_frame_extended
203 return new ChopFrame(frameType, in.readUnsignedShort());
204 } else if (frameType == SAME_FRAME_EXTENDED) {
205 // chop_frame or same_frame_extended
206 return new SameFrame(frameType, in.readUnsignedShort());
207 } else if (SAME_FRAME_EXTENDED < frameType && frameType < FULL_FRAME) {
209 return new AppendFrame(frameType, in.readUnsignedShort(),
210 StackMapData.readTypeArray(in, frameType - SAME_FRAME_EXTENDED, method));
211 } else if (frameType == FULL_FRAME) {
213 int offsetDelta = in.readUnsignedShort();
214 int locals_size = in.readUnsignedShort();
215 int[] locals = StackMapData.readTypeArray(in, locals_size, method);
216 int stack_size = in.readUnsignedShort();
217 int[] stack = StackMapData.readTypeArray(in, stack_size, method);
218 return new FullFrame(offsetDelta, locals, stack);
220 throw new ClassFormatError("unrecognized frame_type in StackMapTable");