| //===--- DerivedConformanceActor.cpp - Derived Actor Conformance ----------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements implicit derivation of the Actor protocol. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "DerivedConformances.h" |
| #include "TypeChecker.h" |
| #include "TypeCheckConcurrency.h" |
| #include "swift/AST/NameLookupRequests.h" |
| #include "swift/AST/ParameterList.h" |
| |
| using namespace swift; |
| |
| bool DerivedConformance::canDeriveActor( |
| NominalTypeDecl *nominal, DeclContext *dc) { |
| auto classDecl = dyn_cast<ClassDecl>(nominal); |
| return classDecl && classDecl->isActor() && dc == nominal; |
| } |
| |
| static DeclName getEnqueuePartialTaskName(ASTContext &ctx) { |
| return DeclName(ctx, ctx.Id_enqueue, { ctx.Id_partialTask }); |
| } |
| |
| static Type getPartialAsyncTaskType(ASTContext &ctx) { |
| auto concurrencyModule = ctx.getLoadedModule(ctx.Id_Concurrency); |
| if (!concurrencyModule) |
| return Type(); |
| |
| SmallVector<ValueDecl *, 2> decls; |
| concurrencyModule->lookupQualified( |
| concurrencyModule, DeclNameRef(ctx.Id_PartialAsyncTask), |
| NL_QualifiedDefault, decls); |
| for (auto decl : decls) { |
| if (auto typeDecl = dyn_cast<TypeDecl>(decl)) |
| return typeDecl->getDeclaredInterfaceType(); |
| } |
| |
| return Type(); |
| } |
| |
| /// Look for the default enqueue operation. |
| static FuncDecl *getDefaultActorEnqueue(DeclContext *dc, SourceLoc loc) { |
| ASTContext &ctx = dc->getASTContext(); |
| auto desc = UnqualifiedLookupDescriptor( |
| DeclNameRef(ctx.Id__defaultActorEnqueue), |
| dc, loc, UnqualifiedLookupOptions()); |
| auto lookup = |
| evaluateOrDefault(ctx.evaluator, UnqualifiedLookupRequest{desc}, {}); |
| for (const auto &result : lookup) { |
| // FIXME: Validate this further, because we're assuming the exact type. |
| if (auto func = dyn_cast<FuncDecl>(result.getValueDecl())) |
| return func; |
| } |
| |
| return nullptr; |
| } |
| |
| static std::pair<BraceStmt *, bool> |
| deriveBodyActor_enqueuePartialTask( |
| AbstractFunctionDecl *enqueuePartialTask, void *) { |
| // func enqueue(partialTask: PartialAsyncTask) { |
| // _defaultActorEnqueue(partialTask: partialTask, actor: self) |
| // } |
| ASTContext &ctx = enqueuePartialTask->getASTContext(); |
| auto classDecl = enqueuePartialTask->getDeclContext()->getSelfClassDecl(); |
| |
| // Produce an empty brace statement on failure. |
| auto failure = [&]() -> std::pair<BraceStmt *, bool> { |
| auto body = BraceStmt::create( |
| ctx, SourceLoc(), { }, SourceLoc(), /*implicit=*/true); |
| return { body, /*isTypeChecked=*/true }; |
| }; |
| |
| // Call into the runtime to enqueue the task. |
| auto fn = getDefaultActorEnqueue(classDecl, classDecl->getLoc()); |
| if (!fn) { |
| classDecl->diagnose( |
| diag::concurrency_lib_missing, ctx.Id__defaultActorEnqueue.str()); |
| return failure(); |
| } |
| |
| // Reference to _defaultActorEnqueue. |
| auto fnRef = new (ctx) DeclRefExpr(fn, DeclNameLoc(), /*Implicit=*/true); |
| fnRef->setType(fn->getInterfaceType()); |
| |
| // self argument to the function. |
| auto selfDecl = enqueuePartialTask->getImplicitSelfDecl(); |
| Type selfType = enqueuePartialTask->mapTypeIntoContext( |
| selfDecl->getValueInterfaceType()); |
| Expr *selfArg = new (ctx) DeclRefExpr( |
| selfDecl, DeclNameLoc(), /*Implicit=*/true, AccessSemantics::Ordinary, |
| selfType); |
| selfArg = ErasureExpr::create(ctx, selfArg, ctx.getAnyObjectType(), { }); |
| selfArg->setImplicit(); |
| |
| // The partial asynchronous task. |
| auto partialTaskParam = enqueuePartialTask->getParameters()->get(0); |
| Expr *partialTask = new (ctx) DeclRefExpr( |
| partialTaskParam, DeclNameLoc(), /*Implicit=*/true, |
| AccessSemantics::Ordinary, |
| enqueuePartialTask->mapTypeIntoContext( |
| partialTaskParam->getValueInterfaceType())); |
| |
| // Form the call itself. |
| auto call = CallExpr::createImplicit( |
| ctx, fnRef, { partialTask, selfArg }, |
| { ctx.Id_partialTask, ctx.getIdentifier("actor") }); |
| call->setType(fn->getResultInterfaceType()); |
| call->setThrows(false); |
| |
| auto body = BraceStmt::create( |
| ctx, SourceLoc(), { call }, SourceLoc(), /*implicit=*/true); |
| return { body, /*isTypeChecked=*/true }; |
| } |
| |
| /// Derive the declaration of Actor's enqueue(partialTask:). |
| static ValueDecl *deriveActor_enqueuePartialTask(DerivedConformance &derived) { |
| ASTContext &ctx = derived.Context; |
| |
| // Retrieve the types and declarations we'll need to form this operation. |
| Type partialTaskType = getPartialAsyncTaskType(ctx); |
| if (!partialTaskType) { |
| derived.Nominal->diagnose( |
| diag::concurrency_lib_missing, ctx.Id_PartialAsyncTask.str()); |
| return nullptr; |
| } |
| |
| auto parentDC = derived.getConformanceContext(); |
| |
| // Partial task parameter to enqueue(partialTask:). |
| auto partialTaskParamDecl = new (ctx) ParamDecl( |
| SourceLoc(), SourceLoc(), ctx.Id_partialTask, |
| SourceLoc(), ctx.Id_partialTask, parentDC); |
| partialTaskParamDecl->setInterfaceType(partialTaskType); |
| partialTaskParamDecl->setSpecifier(ParamSpecifier::Default); |
| |
| // enqueue(partialTask:) method. |
| ParameterList *params = ParameterList::createWithoutLoc(partialTaskParamDecl); |
| auto func = FuncDecl::createImplicit( |
| ctx, StaticSpellingKind::None, getEnqueuePartialTaskName(ctx), |
| SourceLoc(), /*Async=*/false, /*Throws=*/false, /*GenericParams=*/nullptr, |
| params, TupleType::getEmpty(ctx), parentDC); |
| func->copyFormalAccessFrom(derived.Nominal); |
| func->setBodySynthesizer(deriveBodyActor_enqueuePartialTask); |
| func->setSynthesized(); |
| // mark as @actorIndependent(unsafe) |
| func->getAttrs().add(new (ctx) ActorIndependentAttr( |
| ActorIndependentKind::Unsafe, /*IsImplicit=*/true)); |
| |
| derived.addMembersToConformanceContext( |
| { func }); |
| return func; |
| } |
| |
| ValueDecl *DerivedConformance::deriveActor(ValueDecl *requirement) { |
| auto func = dyn_cast<FuncDecl>(requirement); |
| if (!func) |
| return nullptr; |
| |
| if (FuncDecl::isEnqueuePartialTaskName(Context, func->getName())) |
| return deriveActor_enqueuePartialTask(*this); |
| |
| return nullptr; |
| } |