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27 package org.apidesign.javap;
31 import static org.apidesign.javap.RuntimeConstants.*;
33 /* represents one entry of StackMapTable attribute
35 class StackMapTableData {
39 StackMapTableData(int frameType) {
40 this.frameType = frameType;
43 static class SameFrame extends StackMapTableData {
44 SameFrame(int frameType, int offsetDelta) {
46 this.offsetDelta = offsetDelta;
50 static class SameLocals1StackItem extends StackMapTableData {
52 SameLocals1StackItem(int frameType, int offsetDelta, int[] stack) {
54 this.offsetDelta = offsetDelta;
59 static class ChopFrame extends StackMapTableData {
60 ChopFrame(int frameType, int offsetDelta) {
62 this.offsetDelta = offsetDelta;
66 static class AppendFrame extends StackMapTableData {
68 AppendFrame(int frameType, int offsetDelta, int[] locals) {
70 this.offsetDelta = offsetDelta;
75 static class FullFrame extends StackMapTableData {
78 FullFrame(int offsetDelta, int[] locals, int[] stack) {
80 this.offsetDelta = offsetDelta;
86 static StackMapTableData getInstance(DataInputStream in, MethodData method)
88 int frameType = in.readUnsignedByte();
90 if (frameType < SAME_FRAME_BOUND) {
92 return new SameFrame(frameType, frameType);
93 } else if (SAME_FRAME_BOUND <= frameType && frameType < SAME_LOCALS_1_STACK_ITEM_BOUND) {
94 // same_locals_1_stack_item_frame
95 // read additional single stack element
96 return new SameLocals1StackItem(frameType,
97 (frameType - SAME_FRAME_BOUND),
98 StackMapData.readTypeArray(in, 1, method));
99 } else if (frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
100 // same_locals_1_stack_item_extended
101 return new SameLocals1StackItem(frameType,
102 in.readUnsignedShort(),
103 StackMapData.readTypeArray(in, 1, method));
104 } else if (SAME_LOCALS_1_STACK_ITEM_EXTENDED < frameType && frameType < SAME_FRAME_EXTENDED) {
105 // chop_frame or same_frame_extended
106 return new ChopFrame(frameType, in.readUnsignedShort());
107 } else if (frameType == SAME_FRAME_EXTENDED) {
108 // chop_frame or same_frame_extended
109 return new SameFrame(frameType, in.readUnsignedShort());
110 } else if (SAME_FRAME_EXTENDED < frameType && frameType < FULL_FRAME) {
112 return new AppendFrame(frameType, in.readUnsignedShort(),
113 StackMapData.readTypeArray(in, frameType - SAME_FRAME_EXTENDED, method));
114 } else if (frameType == FULL_FRAME) {
116 int offsetDelta = in.readUnsignedShort();
117 int locals_size = in.readUnsignedShort();
118 int[] locals = StackMapData.readTypeArray(in, locals_size, method);
119 int stack_size = in.readUnsignedShort();
120 int[] stack = StackMapData.readTypeArray(in, stack_size, method);
121 return new FullFrame(offsetDelta, locals, stack);
123 throw new ClassFormatError("unrecognized frame_type in StackMapTable");