| // 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.ir.desugar; |
| |
| import com.android.tools.r8.dex.Constants; |
| import com.android.tools.r8.graph.*; |
| import com.android.tools.r8.ir.code.IRCode; |
| import com.android.tools.r8.ir.code.Instruction; |
| import com.android.tools.r8.ir.code.InstructionListIterator; |
| import com.android.tools.r8.ir.code.InvokeMethod; |
| import com.android.tools.r8.ir.code.InvokeStatic; |
| import com.android.tools.r8.ir.conversion.IRConverter; |
| import com.android.tools.r8.utils.StringDiagnostic; |
| import com.google.common.collect.Maps; |
| import com.google.common.collect.Sets; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.IdentityHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.function.Consumer; |
| |
| public class DesugaredLibraryRetargeter { |
| |
| public static final String DESUGAR_LIB_RETARGET_CLASS_NAME_PREFIX = |
| "$r8$retargetLibraryMember$virtualDispatch"; |
| |
| private final AppView<AppInfoWithClassHierarchy> appView; |
| private final Map<DexMethod, DexMethod> retargetLibraryMember = new IdentityHashMap<>(); |
| // Map virtualRewrites hold a methodName->method mapping for virtual methods which are |
| // rewritten while the holder is non final but no superclass implement the method. In this case |
| // d8 needs to force resolution of given methods to see if the invoke needs to be rewritten. |
| private final Map<DexString, List<DexMethod>> virtualRewrites = new IdentityHashMap<>(); |
| // Non final virtual library methods requiring generation of emulated dispatch. |
| private final Set<DexMethod> emulatedDispatchMethods = Sets.newHashSet(); |
| |
| public DesugaredLibraryRetargeter(AppView<?> appView) { |
| assert appView.appInfo().hasClassHierarchy() |
| : "Class hierarchy required for desugared library."; |
| this.appView = appView.withClassHierarchy(); |
| if (appView.options().desugaredLibraryConfiguration.getRetargetCoreLibMember().isEmpty()) { |
| return; |
| } |
| new RetargetingSetup().setUpRetargeting(); |
| } |
| |
| public static void checkForAssumedLibraryTypes(AppView<?> appView) { |
| Map<DexString, Map<DexType, DexType>> retargetCoreLibMember = |
| appView.options().desugaredLibraryConfiguration.getRetargetCoreLibMember(); |
| for (DexString methodName : retargetCoreLibMember.keySet()) { |
| for (DexType inType : retargetCoreLibMember.get(methodName).keySet()) { |
| DexClass typeClass = appView.definitionFor(inType); |
| if (typeClass == null) { |
| warnMissingRetargetCoreLibraryMember(inType, appView); |
| } |
| } |
| } |
| } |
| |
| private static void warnMissingRetargetCoreLibraryMember(DexType type, AppView<?> appView) { |
| StringDiagnostic warning = |
| new StringDiagnostic( |
| "Cannot retarget core library member " |
| + type.getName() |
| + " because the class is missing."); |
| appView.options().reporter.warning(warning); |
| } |
| |
| // Used by the ListOfBackportedMethods utility. |
| void visit(Consumer<DexMethod> consumer) { |
| retargetLibraryMember.keySet().forEach(consumer); |
| } |
| |
| public void desugar(IRCode code) { |
| if (retargetLibraryMember.isEmpty()) { |
| return; |
| } |
| |
| InstructionListIterator iterator = code.instructionListIterator(); |
| while (iterator.hasNext()) { |
| Instruction instruction = iterator.next(); |
| if (!instruction.isInvokeMethod()) { |
| continue; |
| } |
| |
| InvokeMethod invoke = instruction.asInvokeMethod(); |
| DexMethod retarget = getRetargetLibraryMember(invoke.getInvokedMethod()); |
| if (retarget == null) { |
| if (!matchesVirtualRewrite(invoke.getInvokedMethod())) { |
| continue; |
| } |
| // We need to force resolution, even on d8, to know if the invoke has to be rewritten. |
| ResolutionResult resolutionResult = |
| appView |
| .appInfo() |
| .resolveMethod(invoke.getInvokedMethod().holder, invoke.getInvokedMethod()); |
| if (resolutionResult.isFailedResolution()) { |
| continue; |
| } |
| DexEncodedMethod singleTarget = resolutionResult.getSingleTarget(); |
| assert singleTarget != null; |
| retarget = getRetargetLibraryMember(singleTarget.method); |
| if (retarget == null) { |
| continue; |
| } |
| } |
| |
| // Due to emulated dispatch, we have to rewrite invoke-super differently or we end up in |
| // infinite loops. We do direct resolution. This is a very uncommon case. |
| if (invoke.isInvokeSuper() && matchesVirtualRewrite(invoke.getInvokedMethod())) { |
| DexEncodedMethod dexEncodedMethod = |
| appView |
| .appInfo() |
| .withClassHierarchy() |
| .lookupSuperTarget(invoke.getInvokedMethod(), code.method.holder()); |
| // Final methods can be rewritten as a normal invoke. |
| if (dexEncodedMethod != null && !dexEncodedMethod.isFinal()) { |
| DexMethod retargetMethod = |
| appView |
| .options() |
| .desugaredLibraryConfiguration |
| .retargetMethod(dexEncodedMethod.method, appView); |
| if (retargetMethod != null) { |
| iterator.replaceCurrentInstruction( |
| new InvokeStatic(retargetMethod, invoke.outValue(), invoke.arguments())); |
| } |
| continue; |
| } |
| } |
| |
| iterator.replaceCurrentInstruction( |
| new InvokeStatic(retarget, invoke.outValue(), invoke.inValues())); |
| } |
| } |
| |
| private DexMethod getRetargetLibraryMember(DexMethod method) { |
| Map<DexType, DexType> backportCoreLibraryMembers = |
| appView.options().desugaredLibraryConfiguration.getBackportCoreLibraryMember(); |
| if (backportCoreLibraryMembers.containsKey(method.holder)) { |
| DexType newHolder = backportCoreLibraryMembers.get(method.holder); |
| return appView.dexItemFactory().createMethod(newHolder, method.proto, method.name); |
| } |
| return retargetLibraryMember.get(method); |
| } |
| |
| private boolean matchesVirtualRewrite(DexMethod method) { |
| List<DexMethod> dexMethods = virtualRewrites.get(method.name); |
| if (dexMethods == null) { |
| return false; |
| } |
| for (DexMethod dexMethod : dexMethods) { |
| if (method.match(dexMethod)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private class RetargetingSetup { |
| |
| private void setUpRetargeting() { |
| Map<DexString, Map<DexType, DexType>> retargetCoreLibMember = |
| appView.options().desugaredLibraryConfiguration.getRetargetCoreLibMember(); |
| for (DexString methodName : retargetCoreLibMember.keySet()) { |
| for (DexType inType : retargetCoreLibMember.get(methodName).keySet()) { |
| DexClass typeClass = appView.definitionFor(inType); |
| if (typeClass != null) { |
| DexType newHolder = retargetCoreLibMember.get(methodName).get(inType); |
| List<DexEncodedMethod> found = findDexEncodedMethodsWithName(methodName, typeClass); |
| for (DexEncodedMethod encodedMethod : found) { |
| if (!encodedMethod.isStatic()) { |
| virtualRewrites.putIfAbsent(encodedMethod.method.name, new ArrayList<>()); |
| virtualRewrites.get(encodedMethod.method.name).add(encodedMethod.method); |
| if (InterfaceMethodRewriter.isEmulatedInterfaceDispatch(appView, encodedMethod)) { |
| // In this case interface method rewriter takes care of it. |
| continue; |
| } else if (!encodedMethod.isFinal()) { |
| // Virtual rewrites require emulated dispatch for inheritance. |
| // The call is rewritten to the dispatch holder class instead. |
| handleEmulateDispatch(appView, encodedMethod.method); |
| newHolder = dispatchHolderTypeFor(encodedMethod.method); |
| } |
| } |
| DexProto proto = encodedMethod.method.proto; |
| DexMethod method = appView.dexItemFactory().createMethod(inType, proto, methodName); |
| retargetLibraryMember.put( |
| method, computeRetargetMethod(method, encodedMethod.isStatic(), newHolder)); |
| } |
| } |
| } |
| } |
| } |
| |
| private DexMethod computeRetargetMethod(DexMethod method, boolean isStatic, DexType newHolder) { |
| DexItemFactory factory = appView.dexItemFactory(); |
| DexProto newProto = |
| isStatic ? method.proto : factory.prependTypeToProto(method.holder, method.proto); |
| return factory.createMethod(newHolder, newProto, method.name); |
| } |
| |
| private List<DexEncodedMethod> findDexEncodedMethodsWithName( |
| DexString methodName, DexClass clazz) { |
| List<DexEncodedMethod> found = new ArrayList<>(); |
| for (DexEncodedMethod encodedMethod : clazz.methods()) { |
| if (encodedMethod.method.name == methodName) { |
| found.add(encodedMethod); |
| } |
| } |
| assert found.size() > 0 : "Should have found a method (library specifications)."; |
| return found; |
| } |
| |
| private void handleEmulateDispatch(AppView<?> appView, DexMethod method) { |
| emulatedDispatchMethods.add(method); |
| if (!appView.options().isDesugaredLibraryCompilation()) { |
| // Add rewrite rules so keeps rules are correctly generated in the program. |
| DexType dispatchInterfaceType = dispatchInterfaceTypeFor(method); |
| appView.rewritePrefix.rewriteType(dispatchInterfaceType, dispatchInterfaceType); |
| DexType dispatchHolderType = dispatchHolderTypeFor(method); |
| appView.rewritePrefix.rewriteType(dispatchHolderType, dispatchHolderType); |
| } |
| } |
| } |
| |
| public void synthesizeRetargetClasses( |
| DexApplication.Builder<?> builder, ExecutorService executorService, IRConverter converter) |
| throws ExecutionException { |
| new EmulatedDispatchTreeFixer().fixApp(builder, executorService, converter); |
| } |
| |
| // The rewrite of virtual calls requires to go through emulate dispatch. This class is responsible |
| // for inserting interfaces on library boundaries and forwarding methods in the program, and to |
| // synthesize the interfaces and emulated dispatch classes in the desugared library. |
| class EmulatedDispatchTreeFixer { |
| |
| void fixApp( |
| DexApplication.Builder<?> builder, ExecutorService executorService, IRConverter converter) |
| throws ExecutionException { |
| if (appView.options().isDesugaredLibraryCompilation()) { |
| synthesizeEmulatedDispatchMethods(builder); |
| } else { |
| addInterfacesAndForwardingMethods(executorService, converter); |
| } |
| } |
| |
| private void addInterfacesAndForwardingMethods( |
| ExecutorService executorService, IRConverter converter) throws ExecutionException { |
| assert !appView.options().isDesugaredLibraryCompilation(); |
| Map<DexType, List<DexMethod>> map = Maps.newIdentityHashMap(); |
| for (DexMethod emulatedDispatchMethod : emulatedDispatchMethods) { |
| map.putIfAbsent(emulatedDispatchMethod.holder, new ArrayList<>(1)); |
| map.get(emulatedDispatchMethod.holder).add(emulatedDispatchMethod); |
| } |
| List<DexEncodedMethod> addedMethods = new ArrayList<>(); |
| for (DexProgramClass clazz : appView.appInfo().classes()) { |
| if (clazz.superType == null) { |
| assert clazz.type == appView.dexItemFactory().objectType : clazz.type.toSourceString(); |
| continue; |
| } |
| DexClass dexClass = appView.definitionFor(clazz.superType); |
| // Only performs computation if superclass is a library class, but not object to filter out |
| // the most common case. |
| if (dexClass != null |
| && dexClass.isLibraryClass() |
| && dexClass.type != appView.dexItemFactory().objectType) { |
| for (DexType dexType : map.keySet()) { |
| if (inherit(dexClass.asLibraryClass(), dexType)) { |
| addedMethods.addAll(addInterfacesAndForwardingMethods(clazz, map.get(dexType))); |
| } |
| } |
| } |
| } |
| if (addedMethods.isEmpty()) { |
| return; |
| } |
| converter.processMethodsConcurrently(addedMethods, executorService); |
| } |
| |
| private boolean inherit(DexLibraryClass clazz, DexType typeToInherit) { |
| DexLibraryClass current = clazz; |
| while (current.type != appView.dexItemFactory().objectType) { |
| if (current.type == typeToInherit) { |
| return true; |
| } |
| current = appView.definitionFor(current.superType).asLibraryClass(); |
| } |
| return false; |
| } |
| |
| private List<DexEncodedMethod> addInterfacesAndForwardingMethods( |
| DexProgramClass clazz, List<DexMethod> dexMethods) { |
| // DesugaredLibraryRetargeter emulate dispatch: insertion of a marker interface & forwarding |
| // methods. |
| // We cannot use the ClassProcessor since this applies up to 26, while the ClassProcessor |
| // applies up to 24. |
| List<DexEncodedMethod> newForwardingMethods = new ArrayList<>(); |
| for (DexMethod dexMethod : dexMethods) { |
| DexType[] newInterfaces = |
| Arrays.copyOf(clazz.interfaces.values, clazz.interfaces.size() + 1); |
| newInterfaces[newInterfaces.length - 1] = dispatchInterfaceTypeFor(dexMethod); |
| clazz.interfaces = new DexTypeList(newInterfaces); |
| DexEncodedMethod dexEncodedMethod = clazz.lookupVirtualMethod(dexMethod); |
| if (dexEncodedMethod == null) { |
| DexEncodedMethod newMethod = createForwardingMethod(dexMethod, clazz); |
| clazz.addVirtualMethod(newMethod); |
| newForwardingMethods.add(newMethod); |
| } |
| } |
| return newForwardingMethods; |
| } |
| |
| private DexEncodedMethod createForwardingMethod(DexMethod target, DexClass clazz) { |
| // NOTE: Never add a forwarding method to methods of classes unknown or coming from |
| // android.jar |
| // even if this results in invalid code, these classes are never desugared. |
| // In desugared library, emulated interface methods can be overridden by retarget lib members. |
| DexMethod forwardMethod = |
| appView.options().desugaredLibraryConfiguration.retargetMethod(target, appView); |
| assert forwardMethod != null && forwardMethod != target; |
| return DexEncodedMethod.createDesugaringForwardingMethod( |
| appView.definitionFor(target), clazz, forwardMethod, appView.dexItemFactory()); |
| } |
| |
| private void synthesizeEmulatedDispatchMethods(DexApplication.Builder<?> builder) { |
| assert appView.options().isDesugaredLibraryCompilation(); |
| if (emulatedDispatchMethods.isEmpty()) { |
| return; |
| } |
| ClassAccessFlags itfAccessFlags = |
| ClassAccessFlags.fromSharedAccessFlags( |
| Constants.ACC_PUBLIC |
| | Constants.ACC_SYNTHETIC |
| | Constants.ACC_ABSTRACT |
| | Constants.ACC_INTERFACE); |
| ClassAccessFlags holderAccessFlags = |
| ClassAccessFlags.fromSharedAccessFlags(Constants.ACC_PUBLIC | Constants.ACC_SYNTHETIC); |
| for (DexMethod emulatedDispatchMethod : emulatedDispatchMethods) { |
| // Dispatch interface. |
| DexType interfaceType = dispatchInterfaceTypeFor(emulatedDispatchMethod); |
| DexEncodedMethod itfMethod = |
| generateInterfaceDispatchMethod(emulatedDispatchMethod, interfaceType); |
| BackportedMethodRewriter.synthesizeClassWithUniqueMethod( |
| builder, |
| itfAccessFlags, |
| interfaceType, |
| itfMethod, |
| "desugared library dispatch interface", |
| false, |
| appView); |
| // Dispatch holder. |
| DexType holderType = dispatchHolderTypeFor(emulatedDispatchMethod); |
| DexEncodedMethod dispatchMethod = |
| generateHolderDispatchMethod(emulatedDispatchMethod, holderType, itfMethod.method); |
| BackportedMethodRewriter.synthesizeClassWithUniqueMethod( |
| builder, |
| holderAccessFlags, |
| holderType, |
| dispatchMethod, |
| "desugared library dispatch class", |
| false, |
| appView); |
| } |
| } |
| |
| private DexEncodedMethod generateInterfaceDispatchMethod( |
| DexMethod emulatedDispatchMethod, DexType interfaceType) { |
| MethodAccessFlags flags = |
| MethodAccessFlags.fromSharedAccessFlags( |
| Constants.ACC_PUBLIC | Constants.ACC_ABSTRACT | Constants.ACC_SYNTHETIC, false); |
| DexMethod newMethod = |
| appView |
| .dexItemFactory() |
| .createMethod( |
| interfaceType, emulatedDispatchMethod.proto, emulatedDispatchMethod.name); |
| return new DexEncodedMethod( |
| newMethod, flags, DexAnnotationSet.empty(), ParameterAnnotationsList.empty(), null, true); |
| } |
| |
| private DexEncodedMethod generateHolderDispatchMethod( |
| DexMethod emulatedDispatchMethod, DexType dispatchHolder, DexMethod itfMethod) { |
| // The method should look like: |
| // static foo(rcvr, arg0, arg1) { |
| // if (rcvr instanceof interfaceType) { |
| // return invoke-interface receiver.foo(arg0, arg1); |
| // } else { |
| // return DesugarX.foo(rcvr, arg0, arg1) |
| // } |
| // We do not deal with complex cases (multiple retargeting of the same signature in the |
| // same inheritance tree, etc., since they do not happen in the most common desugared library. |
| DexMethod desugarMethod = |
| appView |
| .options() |
| .desugaredLibraryConfiguration |
| .retargetMethod(emulatedDispatchMethod, appView); |
| assert desugarMethod != null; // This method is reached only for retarget core lib members. |
| DexMethod newMethod = |
| appView |
| .dexItemFactory() |
| .createMethod(dispatchHolder, desugarMethod.proto, emulatedDispatchMethod.name); |
| return DexEncodedMethod.toEmulateDispatchLibraryMethod( |
| emulatedDispatchMethod.holder, |
| newMethod, |
| desugarMethod, |
| itfMethod, |
| Collections.emptyList(), |
| appView); |
| } |
| } |
| |
| private DexType dispatchInterfaceTypeFor(DexMethod method) { |
| return dispatchTypeFor(method, "dispatchInterface"); |
| } |
| |
| private DexType dispatchHolderTypeFor(DexMethod method) { |
| return dispatchTypeFor(method, "dispatchHolder"); |
| } |
| |
| private DexType dispatchTypeFor(DexMethod method, String suffix) { |
| String descriptor = |
| "L" |
| + appView |
| .options() |
| .desugaredLibraryConfiguration |
| .getSynthesizedLibraryClassesPackagePrefix() |
| + DESUGAR_LIB_RETARGET_CLASS_NAME_PREFIX |
| + '$' |
| + method.holder.getName() |
| + '$' |
| + method.name |
| + '$' |
| + suffix |
| + ';'; |
| return appView.dexItemFactory().createType(descriptor); |
| } |
| } |
