| /* |
| * 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.dx.dex.code; |
| |
| import com.android.dx.rop.code.RegisterSpecList; |
| import com.android.dx.rop.code.SourcePosition; |
| |
| /** |
| * Instruction which has a single branch target. |
| */ |
| public final class TargetInsn extends FixedSizeInsn { |
| /** {@code non-null;} the branch target */ |
| private CodeAddress target; |
| |
| /** |
| * Constructs an instance. The output address of this instance is initially |
| * unknown ({@code -1}), and the target is initially |
| * {@code null}. |
| * |
| * @param opcode the opcode; one of the constants from {@link Dops} |
| * @param position {@code non-null;} source position |
| * @param registers {@code non-null;} register list, including a |
| * result register if appropriate (that is, registers may be either |
| * ins or outs) |
| * @param target {@code non-null;} the branch target |
| */ |
| public TargetInsn(Dop opcode, SourcePosition position, |
| RegisterSpecList registers, CodeAddress target) { |
| super(opcode, position, registers); |
| |
| if (target == null) { |
| throw new NullPointerException("target == null"); |
| } |
| |
| this.target = target; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public DalvInsn withOpcode(Dop opcode) { |
| return new TargetInsn(opcode, getPosition(), getRegisters(), target); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public DalvInsn withRegisters(RegisterSpecList registers) { |
| return new TargetInsn(getOpcode(), getPosition(), registers, target); |
| } |
| |
| /** |
| * Returns an instance that is just like this one, except that its |
| * opcode has the opposite sense (as a test; e.g. a |
| * {@code lt} test becomes a {@code ge}), and its branch |
| * target is replaced by the one given, and all set-once values |
| * associated with the class (such as its address) are reset. |
| * |
| * @param target {@code non-null;} the new branch target |
| * @return {@code non-null;} an appropriately-constructed instance |
| */ |
| public TargetInsn withNewTargetAndReversed(CodeAddress target) { |
| Dop opcode = getOpcode().getOppositeTest(); |
| |
| return new TargetInsn(opcode, getPosition(), getRegisters(), target); |
| } |
| |
| /** |
| * Gets the unique branch target of this instruction. |
| * |
| * @return {@code non-null;} the branch target |
| */ |
| public CodeAddress getTarget() { |
| return target; |
| } |
| |
| /** |
| * Gets the target address of this instruction. This is only valid |
| * to call if the target instruction has been assigned an address, |
| * and it is merely a convenient shorthand for |
| * {@code getTarget().getAddress()}. |
| * |
| * @return {@code >= 0;} the target address |
| */ |
| public int getTargetAddress() { |
| return target.getAddress(); |
| } |
| |
| /** |
| * Gets the branch offset of this instruction. This is only valid to |
| * call if both this and the target instruction each has been assigned |
| * an address, and it is merely a convenient shorthand for |
| * {@code getTargetAddress() - getAddress()}. |
| * |
| * @return the branch offset |
| */ |
| public int getTargetOffset() { |
| return target.getAddress() - getAddress(); |
| } |
| |
| /** |
| * Returns whether the target offset is known. |
| * |
| * @return {@code true} if the target offset is known or |
| * {@code false} if not |
| */ |
| public boolean hasTargetOffset() { |
| return hasAddress() && target.hasAddress(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected String argString() { |
| if (target == null) { |
| return "????"; |
| } |
| |
| return target.identifierString(); |
| } |
| } |