| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.dexgen.dex.code; |
| |
| import com.android.dexgen.rop.code.RegisterSpecList; |
| import com.android.dexgen.rop.code.SourcePosition; |
| import com.android.dexgen.util.AnnotatedOutput; |
| |
| /** |
| * Pseudo-instruction which either turns into a {@code nop} or |
| * nothingness, in order to make the subsequent instruction have an |
| * even address. This is used to align (subsequent) instructions that |
| * require it. |
| */ |
| public final class OddSpacer extends VariableSizeInsn { |
| /** |
| * Constructs an instance. The output address of this instance is initially |
| * unknown ({@code -1}). |
| * |
| * @param position {@code non-null;} source position |
| */ |
| public OddSpacer(SourcePosition position) { |
| super(position, RegisterSpecList.EMPTY); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int codeSize() { |
| return (getAddress() & 1); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void writeTo(AnnotatedOutput out) { |
| if (codeSize() != 0) { |
| out.writeShort(InsnFormat.codeUnit(DalvOps.NOP, 0)); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public DalvInsn withRegisters(RegisterSpecList registers) { |
| return new OddSpacer(getPosition()); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected String argString() { |
| return null; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected String listingString0(boolean noteIndices) { |
| if (codeSize() == 0) { |
| return null; |
| } |
| |
| return "nop // spacer"; |
| } |
| } |