| // Copyright (c) 2020, 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.horizontalclassmerging; |
| |
| import com.android.tools.r8.cf.CfVersion; |
| import com.android.tools.r8.graph.AppView; |
| import com.android.tools.r8.graph.DexAnnotationSet; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexField; |
| import com.android.tools.r8.graph.DexItemFactory; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexProgramClass; |
| import com.android.tools.r8.graph.GenericSignature.MethodTypeSignature; |
| import com.android.tools.r8.graph.MethodAccessFlags; |
| import com.android.tools.r8.graph.ParameterAnnotationsList; |
| import com.android.tools.r8.graph.ProgramMethod; |
| import com.android.tools.r8.graph.ResolutionResult.SingleResolutionResult; |
| import com.android.tools.r8.ir.synthetic.AbstractSynthesizedCode; |
| import com.android.tools.r8.shaking.AppInfoWithLiveness; |
| import com.android.tools.r8.shaking.FieldAccessInfoCollectionModifier; |
| import com.google.common.collect.Iterables; |
| import it.unimi.dsi.fastutil.ints.Int2ReferenceAVLTreeMap; |
| import it.unimi.dsi.fastutil.ints.Int2ReferenceSortedMap; |
| import it.unimi.dsi.fastutil.objects.Reference2IntMap; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| |
| public class VirtualMethodMerger { |
| private final DexProgramClass target; |
| private final DexItemFactory dexItemFactory; |
| private final Collection<ProgramMethod> methods; |
| private final DexField classIdField; |
| private final AppView<AppInfoWithLiveness> appView; |
| private final DexMethod superMethod; |
| |
| public VirtualMethodMerger( |
| AppView<AppInfoWithLiveness> appView, |
| DexProgramClass target, |
| Collection<ProgramMethod> methods, |
| DexField classIdField, |
| DexMethod superMethod) { |
| this.dexItemFactory = appView.dexItemFactory(); |
| this.target = target; |
| this.classIdField = classIdField; |
| this.methods = methods; |
| this.appView = appView; |
| this.superMethod = superMethod; |
| } |
| |
| public static class Builder { |
| private final Collection<ProgramMethod> methods = new ArrayList<>(); |
| |
| public Builder add(ProgramMethod constructor) { |
| methods.add(constructor); |
| return this; |
| } |
| |
| /** Get the super method handle if this method overrides a parent method. */ |
| private DexMethod superMethod(AppView<AppInfoWithLiveness> appView, DexProgramClass target) { |
| DexMethod template = methods.iterator().next().getReference(); |
| SingleResolutionResult resolutionResult = |
| appView |
| .appInfo() |
| .resolveMethodOnClass(template, target.getSuperType()) |
| .asSingleResolution(); |
| |
| if (resolutionResult == null || resolutionResult.getResolvedMethod().isAbstract()) { |
| // If there is no super method or the method is abstract it should not be called. |
| return null; |
| } |
| if (resolutionResult.getResolvedHolder().isInterface()) { |
| // Ensure that invoke virtual isn't called on an interface method. |
| return resolutionResult |
| .getResolvedMethod() |
| .getReference() |
| .withHolder(target.getSuperType(), appView.dexItemFactory()); |
| } |
| return resolutionResult.getResolvedMethod().getReference(); |
| } |
| |
| public VirtualMethodMerger build( |
| AppView<AppInfoWithLiveness> appView, |
| DexProgramClass target, |
| DexField classIdField, |
| int mergeGroupSize) { |
| // If not all the classes are in the merge group, find the fallback super method to call. |
| DexMethod superMethod = methods.size() < mergeGroupSize ? superMethod(appView, target) : null; |
| |
| return new VirtualMethodMerger(appView, target, methods, classIdField, superMethod); |
| } |
| } |
| |
| public DexMethod getMethodReference() { |
| return methods.iterator().next().getReference(); |
| } |
| |
| public int getArity() { |
| return getMethodReference().getArity(); |
| } |
| |
| private DexMethod moveMethod(ClassMethodsBuilder classMethodsBuilder, ProgramMethod oldMethod) { |
| DexMethod oldMethodReference = oldMethod.getReference(); |
| DexMethod method = |
| dexItemFactory.createFreshMethodName( |
| oldMethodReference.name.toSourceString(), |
| oldMethod.getHolderType(), |
| oldMethodReference.proto, |
| target.type, |
| classMethodsBuilder::isFresh); |
| |
| DexEncodedMethod encodedMethod = oldMethod.getDefinition().toTypeSubstitutedMethod(method); |
| MethodAccessFlags flags = encodedMethod.accessFlags; |
| flags.unsetProtected(); |
| flags.unsetPublic(); |
| flags.setPrivate(); |
| classMethodsBuilder.addDirectMethod(encodedMethod); |
| |
| return encodedMethod.method; |
| } |
| |
| private MethodAccessFlags getAccessFlags() { |
| // TODO(b/164998929): ensure this behaviour is correct, should probably calculate upper bound |
| MethodAccessFlags flags = methods.iterator().next().getDefinition().getAccessFlags().copy(); |
| if (flags.isFinal() && Iterables.any(methods, method -> !method.getAccessFlags().isFinal())) { |
| flags.unsetFinal(); |
| } |
| return flags; |
| } |
| |
| /** |
| * If there is only a single method that does not override anything then it is safe to just move |
| * it to the target type if it is not already in it. |
| */ |
| public void mergeTrivial( |
| ClassMethodsBuilder classMethodsBuilder, HorizontalClassMergerGraphLens.Builder lensBuilder) { |
| DexEncodedMethod method = methods.iterator().next().getDefinition(); |
| |
| if (method.getHolderType() != target.type) { |
| // If the method is not in the target type, move it and record it in the lens. |
| DexMethod originalReference = method.getReference(); |
| method = method.toRenamedHolderMethod(target.type, dexItemFactory); |
| lensBuilder.moveMethod(originalReference, method.getReference()); |
| } |
| |
| classMethodsBuilder.addVirtualMethod(method); |
| } |
| |
| public void merge( |
| ClassMethodsBuilder classMethodsBuilder, |
| HorizontalClassMergerGraphLens.Builder lensBuilder, |
| FieldAccessInfoCollectionModifier.Builder fieldAccessChangesBuilder, |
| Reference2IntMap classIdentifiers) { |
| |
| assert !methods.isEmpty(); |
| |
| // Handle trivial merges. |
| if (superMethod == null && methods.size() == 1) { |
| mergeTrivial(classMethodsBuilder, lensBuilder); |
| return; |
| } |
| |
| Int2ReferenceSortedMap<DexMethod> classIdToMethodMap = new Int2ReferenceAVLTreeMap<>(); |
| |
| CfVersion classFileVersion = null; |
| for (ProgramMethod method : methods) { |
| if (method.getDefinition().hasClassFileVersion()) { |
| CfVersion methodVersion = method.getDefinition().getClassFileVersion(); |
| classFileVersion = CfVersion.maxAllowNull(classFileVersion, methodVersion); |
| } |
| DexMethod newMethod = moveMethod(classMethodsBuilder, method); |
| lensBuilder.mapMethod(newMethod, newMethod); |
| lensBuilder.mapMethodInverse(method.getReference(), newMethod); |
| classIdToMethodMap.put(classIdentifiers.getInt(method.getHolderType()), newMethod); |
| } |
| |
| // Use the first of the original methods as the original method for the merged constructor. |
| DexMethod templateReference = methods.iterator().next().getReference(); |
| DexMethod originalMethodReference = |
| appView.graphLens().getOriginalMethodSignature(templateReference); |
| DexMethod bridgeMethodReference = |
| dexItemFactory.createFreshMethodName( |
| originalMethodReference.getName().toSourceString() + "$bridge", |
| null, |
| originalMethodReference.proto, |
| originalMethodReference.getHolderType(), |
| classMethodsBuilder::isFresh); |
| |
| DexMethod newMethodReference = |
| dexItemFactory.createMethod(target.type, templateReference.proto, templateReference.name); |
| AbstractSynthesizedCode synthesizedCode = |
| new VirtualMethodEntryPointSynthesizedCode( |
| classIdToMethodMap, |
| classIdField, |
| superMethod, |
| newMethodReference, |
| bridgeMethodReference); |
| DexEncodedMethod newMethod = |
| new DexEncodedMethod( |
| newMethodReference, |
| getAccessFlags(), |
| MethodTypeSignature.noSignature(), |
| DexAnnotationSet.empty(), |
| ParameterAnnotationsList.empty(), |
| synthesizedCode, |
| true, |
| classFileVersion); |
| |
| // Map each old method to the newly synthesized method in the graph lens. |
| for (ProgramMethod oldMethod : methods) { |
| lensBuilder.moveMethod(oldMethod.getReference(), newMethodReference); |
| } |
| lensBuilder.recordExtraOriginalSignature(bridgeMethodReference, newMethodReference); |
| |
| classMethodsBuilder.addVirtualMethod(newMethod); |
| |
| fieldAccessChangesBuilder.fieldReadByMethod(classIdField, newMethod.method); |
| } |
| } |
