jtulach@144: /*
jtulach@144:  * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
jtulach@144:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jtulach@144:  *
jtulach@144:  * This code is free software; you can redistribute it and/or modify it
jtulach@144:  * under the terms of the GNU General Public License version 2 only, as
jtulach@144:  * published by the Free Software Foundation.  Oracle designates this
jtulach@144:  * particular file as subject to the "Classpath" exception as provided
jtulach@144:  * by Oracle in the LICENSE file that accompanied this code.
jtulach@144:  *
jtulach@144:  * This code is distributed in the hope that it will be useful, but WITHOUT
jtulach@144:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jtulach@144:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jtulach@144:  * version 2 for more details (a copy is included in the LICENSE file that
jtulach@144:  * accompanied this code).
jtulach@144:  *
jtulach@144:  * You should have received a copy of the GNU General Public License version
jtulach@144:  * 2 along with this work; if not, write to the Free Software Foundation,
jtulach@144:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jtulach@144:  *
jtulach@144:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jtulach@144:  * or visit www.oracle.com if you need additional information or have any
jtulach@144:  * questions.
jtulach@144:  */
jtulach@144: 
jtulach@144: 
jtulach@167: package org.apidesign.javap;
jtulach@144: 
jtulach@144: import java.io.*;
jtulach@144: 
jtulach@167: import static org.apidesign.javap.RuntimeConstants.*;
jtulach@144: 
jtulach@144: /* represents one entry of StackMapTable attribute
jtulach@144:  */
jtulach@144: class StackMapTableData {
jtulach@144:     final int frameType;
jtulach@144:     int offsetDelta;
jtulach@144: 
jtulach@144:     StackMapTableData(int frameType) {
jtulach@144:         this.frameType = frameType;
jtulach@144:     }
jtulach@144: 
jtulach@144:     static class SameFrame extends StackMapTableData {
jtulach@144:         SameFrame(int frameType, int offsetDelta) {
jtulach@144:             super(frameType);
jtulach@144:             this.offsetDelta = offsetDelta;
jtulach@144:         }
jtulach@144:     }
jtulach@144: 
jtulach@144:     static class SameLocals1StackItem extends StackMapTableData {
jtulach@144:         final int[] stack;
jtulach@144:         SameLocals1StackItem(int frameType, int offsetDelta, int[] stack) {
jtulach@144:             super(frameType);
jtulach@144:             this.offsetDelta = offsetDelta;
jtulach@144:             this.stack = stack;
jtulach@144:         }
jtulach@144:     }
jtulach@144: 
jtulach@144:     static class ChopFrame extends StackMapTableData {
jtulach@144:         ChopFrame(int frameType, int offsetDelta) {
jtulach@144:             super(frameType);
jtulach@144:             this.offsetDelta = offsetDelta;
jtulach@144:         }
jtulach@144:     }
jtulach@144: 
jtulach@144:     static class AppendFrame extends StackMapTableData {
jtulach@144:         final int[] locals;
jtulach@144:         AppendFrame(int frameType, int offsetDelta, int[] locals) {
jtulach@144:             super(frameType);
jtulach@144:             this.offsetDelta = offsetDelta;
jtulach@144:             this.locals = locals;
jtulach@144:         }
jtulach@144:     }
jtulach@144: 
jtulach@144:     static class FullFrame extends StackMapTableData {
jtulach@144:         final int[] locals;
jtulach@144:         final int[] stack;
jtulach@144:         FullFrame(int offsetDelta, int[] locals, int[] stack) {
jtulach@144:             super(FULL_FRAME);
jtulach@144:             this.offsetDelta = offsetDelta;
jtulach@144:             this.locals = locals;
jtulach@144:             this.stack = stack;
jtulach@144:         }
jtulach@144:     }
jtulach@144: 
jtulach@144:     static StackMapTableData getInstance(DataInputStream in, MethodData method)
jtulach@144:                   throws IOException {
jtulach@144:         int frameType = in.readUnsignedByte();
jtulach@144: 
jtulach@144:         if (frameType < SAME_FRAME_BOUND) {
jtulach@144:             // same_frame
jtulach@144:             return new SameFrame(frameType, frameType);
jtulach@144:         } else if (SAME_FRAME_BOUND <= frameType && frameType < SAME_LOCALS_1_STACK_ITEM_BOUND) {
jtulach@144:             // same_locals_1_stack_item_frame
jtulach@144:             // read additional single stack element
jtulach@144:             return new SameLocals1StackItem(frameType,
jtulach@144:                                             (frameType - SAME_FRAME_BOUND),
jtulach@144:                                             StackMapData.readTypeArray(in, 1, method));
jtulach@144:         } else if (frameType == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
jtulach@144:             // same_locals_1_stack_item_extended
jtulach@144:             return new SameLocals1StackItem(frameType,
jtulach@144:                                             in.readUnsignedShort(),
jtulach@144:                                             StackMapData.readTypeArray(in, 1, method));
jtulach@144:         } else if (SAME_LOCALS_1_STACK_ITEM_EXTENDED < frameType  && frameType < SAME_FRAME_EXTENDED) {
jtulach@144:             // chop_frame or same_frame_extended
jtulach@144:             return new ChopFrame(frameType, in.readUnsignedShort());
jtulach@144:         } else if (frameType == SAME_FRAME_EXTENDED) {
jtulach@144:             // chop_frame or same_frame_extended
jtulach@144:             return new SameFrame(frameType, in.readUnsignedShort());
jtulach@144:         } else if (SAME_FRAME_EXTENDED < frameType  && frameType < FULL_FRAME) {
jtulach@144:             // append_frame
jtulach@144:             return new AppendFrame(frameType, in.readUnsignedShort(),
jtulach@144:                                    StackMapData.readTypeArray(in, frameType - SAME_FRAME_EXTENDED, method));
jtulach@144:         } else if (frameType == FULL_FRAME) {
jtulach@144:             // full_frame
jtulach@144:             int offsetDelta = in.readUnsignedShort();
jtulach@144:             int locals_size = in.readUnsignedShort();
jtulach@144:             int[] locals = StackMapData.readTypeArray(in, locals_size, method);
jtulach@144:             int stack_size = in.readUnsignedShort();
jtulach@144:             int[] stack = StackMapData.readTypeArray(in, stack_size, method);
jtulach@144:             return new FullFrame(offsetDelta, locals, stack);
jtulach@144:         } else {
jtulach@144:             throw new ClassFormatError("unrecognized frame_type in StackMapTable");
jtulach@144:         }
jtulach@144:     }
jtulach@144: }