1917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul/* 2917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * Copyright (C) 2007 The Android Open Source Project 3917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * 4917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * Licensed under the Apache License, Version 2.0 (the "License"); 5917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * you may not use this file except in compliance with the License. 6917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * You may obtain a copy of the License at 7917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * 8917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * http://www.apache.org/licenses/LICENSE-2.0 9917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * 10917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * Unless required by applicable law or agreed to in writing, software 11917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * distributed under the License is distributed on an "AS IS" BASIS, 12917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * See the License for the specific language governing permissions and 14917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * limitations under the License. 15917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul */ 16917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 17917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgulpackage com.android.dexgen.dex.code; 18917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 19917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgulimport com.android.dexgen.rop.code.RegisterSpecList; 20917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgulimport com.android.dexgen.rop.code.SourcePosition; 21917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgulimport com.android.dexgen.util.AnnotatedOutput; 22917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 23917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul/** 24917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * Pseudo-instruction which either turns into a {@code nop} or 25917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * nothingness, in order to make the subsequent instruction have an 26917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * even address. This is used to align (subsequent) instructions that 27917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * require it. 28917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul */ 29917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgulpublic final class OddSpacer extends VariableSizeInsn { 30917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** 31917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * Constructs an instance. The output address of this instance is initially 32917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * unknown ({@code -1}). 33917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * 34917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul * @param position {@code non-null;} source position 35917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul */ 36917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul public OddSpacer(SourcePosition position) { 37917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul super(position, RegisterSpecList.EMPTY); 38917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 39917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 40917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** {@inheritDoc} */ 41917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul @Override 42917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul public int codeSize() { 43917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul return (getAddress() & 1); 44917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 45917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 46917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** {@inheritDoc} */ 47917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul @Override 48917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul public void writeTo(AnnotatedOutput out) { 49917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul if (codeSize() != 0) { 50917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul out.writeShort(InsnFormat.codeUnit(DalvOps.NOP, 0)); 51917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 52917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 53917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 54917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** {@inheritDoc} */ 55917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul @Override 56917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul public DalvInsn withRegisters(RegisterSpecList registers) { 57917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul return new OddSpacer(getPosition()); 58917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 59917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 60917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** {@inheritDoc} */ 61917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul @Override 62917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul protected String argString() { 63917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul return null; 64917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 65917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 66917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul /** {@inheritDoc} */ 67917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul @Override 68917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul protected String listingString0(boolean noteIndices) { 69917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul if (codeSize() == 0) { 70917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul return null; 71917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 72917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul 73917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul return "nop // spacer"; 74917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul } 75917cb222329ee8c035c3ffaf947e4265761b9367Piotr Gurgul} 76