1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.dx.dex.code; 18 19 import com.android.dx.rop.code.RegisterSpecList; 20 import com.android.dx.rop.code.SourcePosition; 21 import com.android.dx.util.AnnotatedOutput; 22 23 /** 24 * Pseudo-instruction base class for zero-size (no code emitted) 25 * instructions, which are generally used for tracking metainformation 26 * about the code they are adjacent to. 27 */ 28 public abstract class ZeroSizeInsn extends DalvInsn { 29 /** 30 * Constructs an instance. The output address of this instance is initially 31 * unknown ({@code -1}). 32 * 33 * @param position {@code non-null;} source position 34 */ 35 public ZeroSizeInsn(SourcePosition position) { 36 super(Dops.SPECIAL_FORMAT, position, RegisterSpecList.EMPTY); 37 } 38 39 /** {@inheritDoc} */ 40 @Override 41 public final int codeSize() { 42 return 0; 43 } 44 45 /** {@inheritDoc} */ 46 @Override 47 public final void writeTo(AnnotatedOutput out) { 48 // Nothing to do here, for this class. 49 } 50 51 /** {@inheritDoc} */ 52 @Override 53 public final DalvInsn withOpcode(Dop opcode) { 54 throw new RuntimeException("unsupported"); 55 } 56 57 /** {@inheritDoc} */ 58 @Override 59 public DalvInsn withRegisterOffset(int delta) { 60 return withRegisters(getRegisters().withOffset(delta)); 61 } 62 } 63
