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 17package com.android.dx.dex.code; 18 19import com.android.dx.rop.code.RegisterSpec; 20import com.android.dx.rop.code.RegisterSpecList; 21import com.android.dx.rop.code.SourcePosition; 22import com.android.dx.ssa.RegisterMapper; 23 24/** 25 * Pseudo-instruction which is used to introduce a new local variable. That 26 * is, an instance of this class in an instruction stream indicates that 27 * starting with the subsequent instruction, the indicated variable 28 * is bound. 29 */ 30public final class LocalStart extends ZeroSizeInsn { 31 /** 32 * {@code non-null;} register spec representing the local variable introduced 33 * by this instance 34 */ 35 private final RegisterSpec local; 36 37 /** 38 * Returns the local variable listing string for a single register spec. 39 * 40 * @param spec {@code non-null;} the spec to convert 41 * @return {@code non-null;} the string form 42 */ 43 public static String localString(RegisterSpec spec) { 44 return spec.regString() + ' ' + spec.getLocalItem().toString() + ": " + 45 spec.getTypeBearer().toHuman(); 46 } 47 48 /** 49 * Constructs an instance. The output address of this instance is initially 50 * unknown ({@code -1}). 51 * 52 * @param position {@code non-null;} source position 53 * @param local {@code non-null;} register spec representing the local 54 * variable introduced by this instance 55 */ 56 public LocalStart(SourcePosition position, RegisterSpec local) { 57 super(position); 58 59 if (local == null) { 60 throw new NullPointerException("local == null"); 61 } 62 63 this.local = local; 64 } 65 66 /** {@inheritDoc} */ 67 @Override 68 public DalvInsn withRegisterOffset(int delta) { 69 return new LocalStart(getPosition(), local.withOffset(delta)); 70 } 71 72 /** {@inheritDoc} */ 73 @Override 74 public DalvInsn withRegisters(RegisterSpecList registers) { 75 return new LocalStart(getPosition(), local); 76 } 77 78 /** 79 * Gets the register spec representing the local variable introduced 80 * by this instance. 81 * 82 * @return {@code non-null;} the register spec 83 */ 84 public RegisterSpec getLocal() { 85 return local; 86 } 87 88 /** {@inheritDoc} */ 89 @Override 90 protected String argString() { 91 return local.toString(); 92 } 93 94 /** {@inheritDoc} */ 95 @Override 96 protected String listingString0(boolean noteIndices) { 97 return "local-start " + localString(local); 98 } 99 100 /** {@inheritDoc} */ 101 @Override 102 public DalvInsn withMapper(RegisterMapper mapper) { 103 return new LocalStart(getPosition(), mapper.map(local)); 104 } 105} 106