| // Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| package com.android.tools.r8.shaking; |
| |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexField; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexType; |
| import com.android.tools.r8.graph.GraphLense; |
| import com.android.tools.r8.ir.code.Invoke.Type; |
| import com.google.common.collect.ImmutableSet; |
| import java.util.Set; |
| |
| // This graph lense is instantiated during vertical class merging. The graph lense is context |
| // sensitive in the enclosing class of a given invoke *and* the type of the invoke (e.g., invoke- |
| // super vs invoke-virtual). This is illustrated by the following example. |
| // |
| // public class A { |
| // public void m() { ... } |
| // } |
| // public class B extends A { |
| // @Override |
| // public void m() { invoke-super A.m(); ... } |
| // |
| // public void m2() { invoke-virtual A.m(); ... } |
| // } |
| // |
| // Vertical class merging will merge class A into class B. Since class B already has a method with |
| // the signature "void B.m()", the method A.m will be given a fresh name and moved to class B. |
| // During this process, the method corresponding to A.m will be made private such that it can be |
| // called via an invoke-direct instruction. |
| // |
| // For the invocation "invoke-super A.m()" in B.m, this graph lense will return the newly created, |
| // private method corresponding to A.m (that is now in B.m with a fresh name), such that the |
| // invocation will hit the same implementation as the original super.m() call. |
| // |
| // For the invocation "invoke-virtual A.m()" in B.m2, this graph lense will return the method B.m. |
| public class VerticalClassMergerGraphLense extends GraphLense { |
| private final GraphLense previousLense; |
| |
| public VerticalClassMergerGraphLense(GraphLense previousLense) { |
| this.previousLense = previousLense; |
| } |
| |
| @Override |
| public DexType lookupType(DexType type) { |
| return previousLense.lookupType(type); |
| } |
| |
| @Override |
| public DexMethod lookupMethod(DexMethod method, DexEncodedMethod context, Type type) { |
| // TODO(christofferqa): If [type] is Type.SUPER and [method] has been merged into the class of |
| // [context], then return the DIRECT method that has been created for [method] by SimpleClass- |
| // Merger. Otherwise, return the VIRTUAL method corresponding to [method]. |
| return previousLense.lookupMethod(method, context, type); |
| } |
| |
| @Override |
| public Set<DexMethod> lookupMethodInAllContexts(DexMethod method) { |
| DexMethod result = lookupMethod(method); |
| if (result != null) { |
| return ImmutableSet.of(result); |
| } |
| return ImmutableSet.of(); |
| } |
| |
| @Override |
| public DexField lookupField(DexField field) { |
| return previousLense.lookupField(field); |
| } |
| |
| @Override |
| public boolean isContextFreeForMethods() { |
| return false; |
| } |
| |
| @Override |
| public boolean isContextFreeForMethod(DexMethod method) { |
| // TODO(christofferqa): Should return false for methods where this graph lense is context |
| // sensitive. |
| return true; |
| } |
| } |