[embedded] Add support for actors and async let into the embedded Concurrency runtime

lib/IRGen/GenCall.cpp

@@ -4470,44 +4470,9 @@ void irgen::emitTaskCancel(IRGenFunction &IGF, llvm::Value *task) {
   call->setCallingConv(IGF.IGM.SwiftCC);
 }
 
-llvm::Value *irgen::emitTaskCreate(IRGenFunction &IGF, llvm::Value *flags,
-                                   llvm::Value *taskGroup,
-                                   llvm::Value *futureResultType,
-                                   llvm::Value *taskFunction,
-                                   llvm::Value *localContextInfo,
-                                   SubstitutionMap subs) {
-  // Start with empty task options.
-  llvm::Value *taskOptions =
-      llvm::ConstantInt::get(IGF.IGM.SwiftTaskOptionRecordPtrTy, 0);
-
-  // If there is a task group, emit a task group option structure to contain it.
-  if (taskGroup) {
-    TaskOptionRecordFlags optionsFlags(TaskOptionRecordKind::TaskGroup);
-    llvm::Value *optionsFlagsVal = llvm::ConstantInt::get(
-        IGF.IGM.SizeTy, optionsFlags.getOpaqueValue());
-
-    auto optionsRecord = IGF.createAlloca(
-        IGF.IGM.SwiftTaskGroupTaskOptionRecordTy, Alignment(),
-        "task_group_options");
-    auto optionsBaseRecord = IGF.Builder.CreateStructGEP(
-        optionsRecord, 0, Size());
-
-    // Flags
-    IGF.Builder.CreateStore(
-        optionsFlagsVal,
-        IGF.Builder.CreateStructGEP(optionsBaseRecord, 0, Size()));
-    // Parent
-    IGF.Builder.CreateStore(
-        taskOptions, IGF.Builder.CreateStructGEP(optionsBaseRecord, 1, Size()));
-    // TaskGroup
-    IGF.Builder.CreateStore(
-        taskGroup, IGF.Builder.CreateStructGEP(optionsRecord, 1, Size()));
-
-    taskOptions = IGF.Builder.CreateBitOrPointerCast(
-        optionsRecord.getAddress(), IGF.IGM.SwiftTaskOptionRecordPtrTy);
-  }
-
-  // In embedded Swift, create and pass result type info.
+llvm::Value *irgen::addEmbeddedSwiftResultTypeInfo(IRGenFunction &IGF,
+                                                   llvm::Value *taskOptions,
+                                                   SubstitutionMap subs) {
   if (IGF.IGM.Context.LangOpts.hasFeature(Feature::Embedded)) {
     auto optionsRecord =
         IGF.createAlloca(IGF.IGM.SwiftResultTypeInfoTaskOptionRecordTy,
@@ -4561,6 +4526,48 @@ llvm::Value *irgen::emitTaskCreate(IRGenFunction &IGF, llvm::Value *flags,
     taskOptions = IGF.Builder.CreateBitOrPointerCast(
         optionsRecord.getAddress(), IGF.IGM.SwiftTaskOptionRecordPtrTy);
   }
+  return taskOptions;
+}
+
+llvm::Value *irgen::emitTaskCreate(IRGenFunction &IGF, llvm::Value *flags,
+                                   llvm::Value *taskGroup,
+                                   llvm::Value *futureResultType,
+                                   llvm::Value *taskFunction,
+                                   llvm::Value *localContextInfo,
+                                   SubstitutionMap subs) {
+  // Start with empty task options.
+  llvm::Value *taskOptions =
+      llvm::ConstantInt::get(IGF.IGM.SwiftTaskOptionRecordPtrTy, 0);
+
+  // If there is a task group, emit a task group option structure to contain it.
+  if (taskGroup) {
+    TaskOptionRecordFlags optionsFlags(TaskOptionRecordKind::TaskGroup);
+    llvm::Value *optionsFlagsVal = llvm::ConstantInt::get(
+        IGF.IGM.SizeTy, optionsFlags.getOpaqueValue());
+
+    auto optionsRecord = IGF.createAlloca(
+        IGF.IGM.SwiftTaskGroupTaskOptionRecordTy, Alignment(),
+        "task_group_options");
+    auto optionsBaseRecord = IGF.Builder.CreateStructGEP(
+        optionsRecord, 0, Size());
+
+    // Flags
+    IGF.Builder.CreateStore(
+        optionsFlagsVal,
+        IGF.Builder.CreateStructGEP(optionsBaseRecord, 0, Size()));
+    // Parent
+    IGF.Builder.CreateStore(
+        taskOptions, IGF.Builder.CreateStructGEP(optionsBaseRecord, 1, Size()));
+    // TaskGroup
+    IGF.Builder.CreateStore(
+        taskGroup, IGF.Builder.CreateStructGEP(optionsRecord, 1, Size()));
+
+    taskOptions = IGF.Builder.CreateBitOrPointerCast(
+        optionsRecord.getAddress(), IGF.IGM.SwiftTaskOptionRecordPtrTy);
+  }
+
+  // In embedded Swift, create and pass result type info.
+  taskOptions = addEmbeddedSwiftResultTypeInfo(IGF, taskOptions, subs);
 
   assert(futureResultType && "no future?!");
   llvm::CallInst *result = IGF.Builder.CreateCall(

lib/IRGen/GenCall.h

@@ -217,6 +217,10 @@ namespace irgen {
 
   void emitTaskCancel(IRGenFunction &IGF, llvm::Value *task);
 
+  llvm::Value *addEmbeddedSwiftResultTypeInfo(IRGenFunction &IGF,
+                                              llvm::Value *taskOptions,
+                                              SubstitutionMap subs);
+
   /// Emit a call to swift_task_create[_f] with the given flags, options, and
   /// task function.
   llvm::Value *emitTaskCreate(

lib/IRGen/GenConcurrency.cpp

@@ -19,6 +19,7 @@
 
 #include "BitPatternBuilder.h"
 #include "ExtraInhabitants.h"
+#include "GenCall.h"
 #include "GenProto.h"
 #include "GenType.h"
 #include "IRGenDebugInfo.h"
@@ -226,7 +227,13 @@ llvm::Value *irgen::emitBuiltinStartAsyncLet(IRGenFunction &IGF,
   assert(subs.getReplacementTypes().size() == 1 &&
          "startAsyncLet should have a type substitution");
   auto futureResultType = subs.getReplacementTypes()[0]->getCanonicalType();
-  auto futureResultTypeMetadata = IGF.emitAbstractTypeMetadataRef(futureResultType);
+
+  llvm::Value *futureResultTypeMetadata =
+      llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy);
+  if (!IGF.IGM.Context.LangOpts.hasFeature(Feature::Embedded)) {
+    futureResultTypeMetadata =
+        IGF.emitAbstractTypeMetadataRef(futureResultType);
+  }
 
   // The concurrency runtime for older Apple OSes has a bug in task formation
   // for `async let`s that may manifest when trying to use room in the
@@ -269,6 +276,9 @@ llvm::Value *irgen::emitBuiltinStartAsyncLet(IRGenFunction &IGF,
       IGF.IGM.markAsyncFunctionPointerForPadding(taskAsyncFunctionPointer);
     }
   }
+
+  // In embedded Swift, create and pass result type info.
+  taskOptions = addEmbeddedSwiftResultTypeInfo(IGF, taskOptions, subs);
 
   llvm::CallInst *call;
   if (localResultBuffer) {

stdlib/public/Concurrency/AsyncLet.cpp

@@ -393,7 +393,11 @@ static void _asyncLet_finish_continuation(
 
   // Destroy the error, or the result that was stored to the buffer.
   if (error) {
+    #if SWIFT_CONCURRENCY_EMBEDDED
+    swift_unreachable("untyped error used in embedded Swift");
+    #else
     swift_errorRelease((SwiftError*)error);
+    #endif
   } else {
     alet->getTask()->futureFragment()->getResultType().vw_destroy(resultBuffer);
   }

stdlib/public/Concurrency/CMakeLists.txt

@@ -188,6 +188,7 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB AND SWIFT_SHOULD_BUILD_EMBEDDED_CONCURRENC
   set(SWIFT_STDLIB_STABLE_ABI OFF)
   set(SWIFT_STDLIB_ENABLE_OBJC_INTEROP OFF)
   set(SWIFT_STDLIB_SINGLE_THREADED_CONCURRENCY TRUE)
+  set(SWIFT_STDLIB_CONCURRENCY_TRACING FALSE)
 
   foreach(entry ${EMBEDDED_STDLIB_TARGET_TRIPLES})
     string(REGEX REPLACE "[ \t]+" ";" list "${entry}")
@@ -210,12 +211,33 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB AND SWIFT_SHOULD_BUILD_EMBEDDED_CONCURRENC
       IS_STDLIB
 
       ${SWIFT_RUNTIME_CONCURRENCY_C_SOURCES}
-      # TODO: Only a handful of Swift Concurrency .swift sources, for now.
-      Task.swift
+      # TODO: Only a subset of Swift Concurrency .swift sources, for now.
+      Actor.swift
       AsyncLet.swift
-      Executor.swift
+      CheckedContinuation.swift
       Errors.swift
+      Executor.swift
+      ExecutorAssertions.swift
+      AsyncCompactMapSequence.swift
+      AsyncDropFirstSequence.swift
+      AsyncDropWhileSequence.swift
+      AsyncFilterSequence.swift
+      AsyncFlatMapSequence.swift
+      AsyncIteratorProtocol.swift
+      AsyncMapSequence.swift
+      AsyncPrefixSequence.swift
+      AsyncPrefixWhileSequence.swift
+      AsyncSequence.swift
+      AsyncThrowingCompactMapSequence.swift
+      AsyncThrowingDropWhileSequence.swift
+      AsyncThrowingFilterSequence.swift
+      AsyncThrowingFlatMapSequence.swift
+      AsyncThrowingMapSequence.swift
+      AsyncThrowingPrefixWhileSequence.swift
+      GlobalActor.swift
       PartialAsyncTask.swift
+      Task.swift
+      TaskCancellation.swift
 
       SWIFT_COMPILE_FLAGS
         -Xcc -D__MACH__ -Xcc -D__APPLE__ -Xcc -ffreestanding -enable-experimental-feature Embedded

stdlib/public/Concurrency/CheckedContinuation.swift

@@ -19,6 +19,7 @@ internal func logFailedCheck(_ message: UnsafeRawPointer)
 /// Implementation class that holds the `UnsafeContinuation` instance for
 /// a `CheckedContinuation`.
 @available(SwiftStdlib 5.1, *)
+@_unavailableInEmbedded
 internal final class CheckedContinuationCanary: @unchecked Sendable {
   // The instance state is stored in tail-allocated raw memory, so that
   // we can atomically check the continuation state.
@@ -119,6 +120,7 @@ internal final class CheckedContinuationCanary: @unchecked Sendable {
 /// you can replace one with the other in most circumstances,
 /// without making other changes.
 @available(SwiftStdlib 5.1, *)
+@_unavailableInEmbedded
 public struct CheckedContinuation<T, E: Error>: Sendable {
   private let canary: CheckedContinuationCanary
 
@@ -187,6 +189,7 @@ public struct CheckedContinuation<T, E: Error>: Sendable {
 }
 
 @available(SwiftStdlib 5.1, *)
+@_unavailableInEmbedded
 extension CheckedContinuation {
   /// Resume the task awaiting the continuation by having it either
   /// return normally or throw an error based on the state of the given
@@ -281,6 +284,7 @@ extension CheckedContinuation {
 @available(SwiftStdlib 5.1, *)
 @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
 @inlinable
+@_unavailableInEmbedded
 public func withCheckedContinuation<T>(
     function: String = #function,
     _ body: (CheckedContinuation<T, Never>) -> Void
@@ -321,6 +325,7 @@ public func withCheckedContinuation<T>(
 @available(SwiftStdlib 5.1, *)
 @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
 @inlinable
+@_unavailableInEmbedded
 public func withCheckedThrowingContinuation<T>(
     function: String = #function,
     _ body: (CheckedContinuation<T, Error>) -> Void

stdlib/public/Concurrency/ExecutorAssertions.swift

@@ -36,6 +36,7 @@ extension SerialExecutor {
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -72,6 +73,7 @@ extension Actor {
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public nonisolated func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -108,6 +110,7 @@ extension GlobalActor {
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public static func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -134,6 +137,7 @@ extension SerialExecutor {
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public func assertIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -167,6 +171,7 @@ extension Actor {
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public nonisolated func assertIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -201,6 +206,7 @@ extension GlobalActor {
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
   @available(SwiftStdlib 5.9, *)
+  @_unavailableInEmbedded
   public static func assertIsolated(
       _ message: @autoclosure () -> String = String(),
       file: StaticString = #fileID, line: UInt = #line
@@ -229,6 +235,7 @@ extension Actor {
   /// perspective, the serial executor guarantees mutual exclusion of those two actors.
   @available(SwiftStdlib 5.9, *)
   @_unavailableFromAsync(message: "express the closure as an explicit function declared on the specified 'actor' instead")
+  @_unavailableInEmbedded
   public nonisolated func assumeIsolated<T>(
       _ operation: (isolated Self) throws -> T,
       file: StaticString = #fileID, line: UInt = #line

stdlib/public/Concurrency/Task.cpp

@@ -1236,11 +1236,15 @@ void swift_task_future_wait_throwingImpl(
   }
 
   case FutureFragment::Status::Error: {
+    #if SWIFT_CONCURRENCY_EMBEDDED
+    swift_unreachable("untyped error used in embedded Swift");
+    #else
     // Run the task with an error result.
     auto future = task->futureFragment();
     auto error = future->getError();
     swift_errorRetain(error);
     return resumeFunction(callerContext, error);
+    #endif
   }
   }
 }

stdlib/public/Concurrency/Task.swift

@@ -840,7 +840,6 @@ extension Task where Failure == Error {
 // ==== Voluntary Suspension -----------------------------------------------------
 
 @available(SwiftStdlib 5.1, *)
-@_unavailableInEmbedded
 extension Task where Success == Never, Failure == Never {
 
   /// Suspends the current task and allows other tasks to execute.

stdlib/public/Concurrency/TaskCancellation.swift

@@ -93,6 +93,7 @@ extension Task where Success == Never, Failure == Never {
   /// The error is always an instance of `CancellationError`.
   ///
   /// - SeeAlso: `isCancelled()`
+  @_unavailableInEmbedded
   public static func checkCancellation() throws {
     if Task<Never, Never>.isCancelled {
       throw _Concurrency.CancellationError()

test/embedded/concurrency-actors.swift

@@ -0,0 +1,73 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -target %target-cpu-apple-macos14 -enable-experimental-feature Embedded -parse-as-library %s %S/Inputs/print.swift -c -o %t/a.o
+// RUN: %target-clang -x c -c %S/Inputs/print.c -o %t/print.o
+// RUN: %target-clang %t/a.o %t/print.o -o %t/a.out %swift_obj_root/lib/swift/embedded/%target-cpu-apple-macos/libswift_Concurrency.a -dead_strip
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: optimized_stdlib
+// REQUIRES: VENDOR=apple
+// REQUIRES: OS=macosx
+
+import _Concurrency
+
+actor Number {
+    var val: Int
+    var task: Task<Void, Never>?
+
+    func increment() {
+        print("did increment")
+        val += 1
+    }
+
+    func fib(n: Int) -> Int {
+        if n < 2 {
+            return n
+        }
+        return fib(n: n-1) + fib(n: n-2)
+    }
+
+    init() async {
+        val = 0
+
+        task = Task.detached(priority: .high) { await self.increment() }
+
+        // do some synchronous work
+        let ans = fib(n: 37)
+        guard ans == 24157817 else {
+            fatalError("miscomputation?")
+        }
+
+        // make sure task didn't modify me!
+        guard val == 0 else {
+            fatalError("race!")
+        }
+
+        print("finished init()")
+    }
+
+    init(iterations: Int) async {
+        var iter = iterations
+        repeat {
+            val = iter
+            iter -= 1
+        } while iter > 0
+    }
+}
+
+@main struct Main {
+    static func main() async {
+
+        // CHECK:       finished init()
+        // CHECK-NEXT:  did increment
+
+        let n1 = await Number()
+        await n1.task!.value
+
+        let n2 = await Number(iterations: 1000)
+        let val = await n2.val
+        guard val == 1 else {
+            fatalError("wrong val setting")
+        }
+    }
+}