| // Copyright (c) 2019, 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.optimize; |
| |
| import com.android.tools.r8.androidapi.AndroidApiLevelCompute; |
| import com.android.tools.r8.contexts.CompilationContext.MethodProcessingContext; |
| import com.android.tools.r8.graph.AppServices; |
| import com.android.tools.r8.graph.AppView; |
| import com.android.tools.r8.graph.DexClass; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexItemFactory.ServiceLoaderMethods; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexProto; |
| import com.android.tools.r8.graph.DexType; |
| import com.android.tools.r8.graph.MethodAccessFlags; |
| import com.android.tools.r8.graph.ProgramMethod; |
| import com.android.tools.r8.ir.code.ConstClass; |
| 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.InvokeStatic; |
| import com.android.tools.r8.ir.code.InvokeVirtual; |
| import com.android.tools.r8.ir.code.Value; |
| import com.android.tools.r8.ir.conversion.MethodProcessor; |
| import com.android.tools.r8.ir.conversion.passes.CodeRewriterPass; |
| import com.android.tools.r8.ir.conversion.passes.result.CodeRewriterResult; |
| import com.android.tools.r8.ir.desugar.ServiceLoaderSourceCode; |
| import com.android.tools.r8.shaking.AppInfoWithLiveness; |
| import com.android.tools.r8.utils.BooleanBox; |
| import com.android.tools.r8.utils.ListUtils; |
| import com.google.common.collect.ImmutableList; |
| import java.util.ArrayList; |
| import java.util.IdentityHashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * ServiceLoaderRewriter will attempt to rewrite calls on the form of: ServiceLoader.load(X.class, |
| * X.class.getClassLoader()).iterator() ... to Arrays.asList(new X[] { new Y(), ..., new Z() |
| * }).iterator() for classes Y..Z specified in the META-INF/services/X. |
| * |
| * <p>The reason for this optimization is to not have the ServiceLoader.load on the distributed R8 |
| * in AGP, since this can potentially conflict with debug versions added to a build.gradle file as: |
| * classpath 'com.android.tools:r8:a.b.c' Additionally, it might also result in improved performance |
| * because ServiceLoader.load is really slow on Android because it has to do a reflective lookup. |
| * |
| * <p>A call to ServiceLoader.load(X.class) is implicitly the same as ServiceLoader.load(X.class, |
| * Thread.getContextClassLoader()) which can have different behavior in Android if a process host |
| * multiple applications: |
| * |
| * <pre> |
| * See <a href="https://stackoverflow.com/questions/13407006/android-class-loader-may-fail-for- |
| * processes-that-host-multiple-applications">https://stackoverflow.com/questions/13407006/ |
| * android-class-loader-may-fail-for-processes-that-host-multiple-applications</a> |
| * </pre> |
| * |
| * We therefore only conservatively rewrite if the invoke is on is on the form |
| * ServiceLoader.load(X.class, X.class.getClassLoader()) or ServiceLoader.load(X.class, null). |
| * |
| * <p>Android Nougat do not use ClassLoader.getSystemClassLoader() when passing null and will almost |
| * certainly fail when trying to find the service. It seems unlikely that programs rely on this |
| * behaviour. |
| */ |
| public class ServiceLoaderRewriter extends CodeRewriterPass<AppInfoWithLiveness> { |
| |
| private final AndroidApiLevelCompute apiLevelCompute; |
| private final ServiceLoaderMethods serviceLoaderMethods; |
| |
| public ServiceLoaderRewriter(AppView<?> appView) { |
| super(appView); |
| this.apiLevelCompute = appView.apiLevelCompute(); |
| this.serviceLoaderMethods = appView.dexItemFactory().serviceLoaderMethods; |
| } |
| |
| @Override |
| protected String getRewriterId() { |
| return "ServiceLoaderRewriter"; |
| } |
| |
| @Override |
| protected boolean shouldRewriteCode(IRCode code, MethodProcessor methodProcessor) { |
| return appView.hasLiveness() |
| && methodProcessor.isPrimaryMethodProcessor() |
| && options.enableServiceLoaderRewriting |
| && code.metadata().mayHaveConstClass() |
| && code.metadata().mayHaveInvokeStatic() |
| && code.metadata().mayHaveInvokeVirtual(); |
| } |
| |
| private boolean shouldReportWhyAreYouNotInliningServiceLoaderLoad() { |
| AppInfoWithLiveness appInfo = appView().appInfo(); |
| return appInfo.isWhyAreYouNotInliningMethod(serviceLoaderMethods.load) |
| || appInfo.isWhyAreYouNotInliningMethod(serviceLoaderMethods.loadWithClassLoader); |
| } |
| |
| @Override |
| protected CodeRewriterResult rewriteCode( |
| IRCode code, |
| MethodProcessor methodProcessor, |
| MethodProcessingContext methodProcessingContext) { |
| InstructionListIterator instructionIterator = code.instructionListIterator(); |
| // Create a map from service type to loader methods local to this context since two |
| // service loader calls to the same type in different methods and in the same wave can race. |
| Map<DexType, DexEncodedMethod> synthesizedServiceLoaders = new IdentityHashMap<>(); |
| while (instructionIterator.hasNext()) { |
| Instruction instruction = instructionIterator.next(); |
| |
| // Check if instruction is an invoke static on the desired form of ServiceLoader.load. |
| if (!instruction.isInvokeStatic()) { |
| continue; |
| } |
| |
| InvokeStatic serviceLoaderLoad = instruction.asInvokeStatic(); |
| DexMethod invokedMethod = serviceLoaderLoad.getInvokedMethod(); |
| if (!serviceLoaderMethods.isLoadMethod(invokedMethod)) { |
| continue; |
| } |
| |
| // Check that the first argument is a const class. |
| Value argument = serviceLoaderLoad.getFirstArgument().getAliasedValue(); |
| if (!argument.isDefinedByInstructionSatisfying(Instruction::isConstClass)) { |
| report(code.context(), null, "The service loader type could not be determined"); |
| continue; |
| } |
| |
| ConstClass constClass = argument.getDefinition().asConstClass(); |
| if (invokedMethod.isNotIdenticalTo(serviceLoaderMethods.loadWithClassLoader)) { |
| report( |
| code.context(), |
| constClass.getType(), |
| "Inlining is only supported for `java.util.ServiceLoader.load(java.lang.Class," |
| + " java.lang.ClassLoader)`"); |
| continue; |
| } |
| |
| String invalidUserMessage = |
| "The returned ServiceLoader instance must only be used in a call to `java.util.Iterator" |
| + " java.lang.ServiceLoader.iterator()`"; |
| Value serviceLoaderLoadOut = serviceLoaderLoad.outValue(); |
| if (!serviceLoaderLoadOut.hasSingleUniqueUser() || serviceLoaderLoadOut.hasPhiUsers()) { |
| report(code.context(), constClass.getType(), invalidUserMessage); |
| continue; |
| } |
| |
| // Check that the only user is a call to iterator(). |
| InvokeVirtual singleUniqueUser = serviceLoaderLoadOut.singleUniqueUser().asInvokeVirtual(); |
| if (singleUniqueUser == null |
| || singleUniqueUser.getInvokedMethod().isNotIdenticalTo(serviceLoaderMethods.iterator)) { |
| report( |
| code.context(), constClass.getType(), invalidUserMessage + ", but found other usages"); |
| continue; |
| } |
| |
| // Check that the service is not kept. |
| if (appView().appInfo().isPinnedWithDefinitionLookup(constClass.getValue())) { |
| report(code.context(), constClass.getType(), "The service loader type is kept"); |
| continue; |
| } |
| |
| // Check that the service is configured in the META-INF/services. |
| AppServices appServices = appView.appServices(); |
| if (!appServices.allServiceTypes().contains(constClass.getValue())) { |
| // Error already reported in the Enqueuer. |
| continue; |
| } |
| |
| // Check that we are not service loading anything from a feature into base. |
| if (appServices.hasServiceImplementationsInFeature(appView(), constClass.getValue())) { |
| report( |
| code.context(), |
| constClass.getType(), |
| "The service loader type has implementations in a feature split"); |
| continue; |
| } |
| |
| // Check that ClassLoader used is the ClassLoader defined for the service configuration |
| // that we are instantiating or NULL. |
| Value classLoaderValue = serviceLoaderLoad.getLastArgument().getAliasedValue(); |
| if (classLoaderValue.isPhi()) { |
| report( |
| code.context(), |
| constClass.getType(), |
| "The java.lang.ClassLoader argument must be defined locally as null or " |
| + constClass.getType() |
| + ".class.getClassLoader()"); |
| continue; |
| } |
| InvokeVirtual classLoaderInvoke = classLoaderValue.getDefinition().asInvokeVirtual(); |
| boolean isGetClassLoaderOnConstClassOrNull = |
| classLoaderValue.getType().isNullType() |
| || (classLoaderInvoke != null |
| && classLoaderInvoke.arguments().size() == 1 |
| && classLoaderInvoke.getReceiver().getAliasedValue().isConstClass() |
| && classLoaderInvoke |
| .getReceiver() |
| .getAliasedValue() |
| .getDefinition() |
| .asConstClass() |
| .getValue() |
| .isIdenticalTo(constClass.getValue())); |
| if (!isGetClassLoaderOnConstClassOrNull) { |
| report( |
| code.context(), |
| constClass.getType(), |
| "The java.lang.ClassLoader argument must be defined locally as null or " |
| + constClass.getType() |
| + ".class.getClassLoader()"); |
| continue; |
| } |
| |
| List<DexType> dexTypes = appServices.serviceImplementationsFor(constClass.getValue()); |
| List<DexClass> classes = new ArrayList<>(dexTypes.size()); |
| boolean seenNull = false; |
| for (DexType serviceImpl : dexTypes) { |
| DexClass serviceImplementation = appView.definitionFor(serviceImpl); |
| if (serviceImplementation == null) { |
| report( |
| code.context(), |
| constClass.getType(), |
| "Unable to find definition for service implementation " + serviceImpl.getTypeName()); |
| seenNull = true; |
| } |
| classes.add(serviceImplementation); |
| } |
| if (seenNull) { |
| continue; |
| } |
| |
| // We can perform the rewrite of the ServiceLoader.load call. |
| DexEncodedMethod synthesizedMethod = |
| synthesizedServiceLoaders.computeIfAbsent( |
| constClass.getValue(), |
| service -> { |
| DexEncodedMethod addedMethod = |
| createSynthesizedMethod( |
| service, classes, methodProcessor, methodProcessingContext); |
| if (appView.options().isGeneratingClassFiles()) { |
| addedMethod.upgradeClassFileVersion( |
| code.context().getDefinition().getClassFileVersion()); |
| } |
| return addedMethod; |
| }); |
| |
| new Rewriter(code, instructionIterator, serviceLoaderLoad) |
| .perform(classLoaderInvoke, synthesizedMethod.getReference()); |
| } |
| assert code.isConsistentSSA(appView); |
| return synthesizedServiceLoaders.isEmpty() |
| ? CodeRewriterResult.NO_CHANGE |
| : CodeRewriterResult.HAS_CHANGED; |
| } |
| |
| private void report(ProgramMethod method, DexType serviceLoaderType, String message) { |
| if (shouldReportWhyAreYouNotInliningServiceLoaderLoad()) { |
| appView |
| .reporter() |
| .info( |
| new ServiceLoaderRewriterDiagnostic( |
| method.getOrigin(), |
| "Could not inline ServiceLoader.load" |
| + (serviceLoaderType == null |
| ? "" |
| : (" of type " + serviceLoaderType.getTypeName())) |
| + ": " |
| + message)); |
| } |
| } |
| |
| private DexEncodedMethod createSynthesizedMethod( |
| DexType serviceType, |
| List<DexClass> classes, |
| MethodProcessor methodProcessor, |
| MethodProcessingContext methodProcessingContext) { |
| DexProto proto = appView.dexItemFactory().createProto(appView.dexItemFactory().iteratorType); |
| ProgramMethod method = |
| appView |
| .getSyntheticItems() |
| .createMethod( |
| kinds -> kinds.SERVICE_LOADER, |
| methodProcessingContext.createUniqueContext(), |
| appView, |
| builder -> |
| builder |
| .setAccessFlags(MethodAccessFlags.createPublicStaticSynthetic()) |
| .setProto(proto) |
| .setApiLevelForDefinition(appView.computedMinApiLevel()) |
| .setApiLevelForCode( |
| apiLevelCompute.computeApiLevelForDefinition( |
| ListUtils.map(classes, clazz -> clazz.type))) |
| .setCode( |
| m -> |
| ServiceLoaderSourceCode.generate( |
| serviceType, classes, appView.dexItemFactory()))); |
| methodProcessor.scheduleDesugaredMethodForProcessing(method); |
| methodProcessor |
| .getEventConsumer() |
| .acceptServiceLoaderLoadUtilityMethod(method, methodProcessingContext.getMethodContext()); |
| return method.getDefinition(); |
| } |
| |
| /** |
| * Rewriter assumes that the code is of the form: |
| * |
| * <pre> |
| * ConstClass v1 <- X |
| * ConstClass v2 <- X or NULL |
| * Invoke-Virtual v3 <- v2; method: java.lang.ClassLoader java.lang.Class.getClassLoader() |
| * Invoke-Static v4 <- v1, v3; method: java.util.ServiceLoader java.util.ServiceLoader |
| * .load(java.lang.Class, java.lang.ClassLoader) |
| * Invoke-Virtual v5 <- v4; method: java.util.Iterator java.util.ServiceLoader.iterator() |
| * </pre> |
| * |
| * and rewrites it to: |
| * |
| * <pre> |
| * Invoke-Static v5 <- ; method: java.util.Iterator syn(X)() |
| * </pre> |
| * |
| * where syn(X) is the synthesized method generated for the service class. |
| * |
| * <p>We rely on the DeadCodeRemover to remove the ConstClasses and any aliased values no longer |
| * used. |
| */ |
| private static class Rewriter { |
| |
| private final IRCode code; |
| private final InvokeStatic serviceLoaderLoad; |
| |
| private final InstructionListIterator iterator; |
| |
| Rewriter(IRCode code, InstructionListIterator iterator, InvokeStatic serviceLoaderLoad) { |
| this.iterator = iterator; |
| this.code = code; |
| this.serviceLoaderLoad = serviceLoaderLoad; |
| } |
| |
| public void perform(InvokeVirtual classLoaderInvoke, DexMethod method) { |
| // Remove the ClassLoader call since this can throw and will not be removed otherwise. |
| if (classLoaderInvoke != null) { |
| BooleanBox allClassLoaderUsersAreServiceLoaders = |
| new BooleanBox(!classLoaderInvoke.outValue().hasPhiUsers()); |
| classLoaderInvoke |
| .outValue() |
| .aliasedUsers() |
| .forEach(user -> allClassLoaderUsersAreServiceLoaders.and(user == serviceLoaderLoad)); |
| if (allClassLoaderUsersAreServiceLoaders.get()) { |
| clearGetClassLoader(classLoaderInvoke); |
| iterator.nextUntil(i -> i == serviceLoaderLoad); |
| } |
| } |
| |
| // Remove the ServiceLoader.load call. |
| InvokeVirtual serviceLoaderIterator = |
| serviceLoaderLoad.outValue().singleUniqueUser().asInvokeVirtual(); |
| iterator.replaceCurrentInstruction(code.createConstNull()); |
| |
| // Find the iterator instruction and replace it. |
| iterator.nextUntil(x -> x == serviceLoaderIterator); |
| InvokeStatic synthesizedInvoke = |
| new InvokeStatic(method, serviceLoaderIterator.outValue(), ImmutableList.of()); |
| iterator.replaceCurrentInstruction(synthesizedInvoke); |
| } |
| |
| private void clearGetClassLoader(InvokeVirtual classLoaderInvoke) { |
| while (iterator.hasPrevious()) { |
| Instruction instruction = iterator.previous(); |
| if (instruction == classLoaderInvoke) { |
| iterator.replaceCurrentInstruction(code.createConstNull()); |
| break; |
| } |
| } |
| } |
| } |
| } |
