Merge pull request #70472 from tshortli/back-deploy-assertassume-isolation

[SE-0392] Back-deploy assertIsolation/assumeIsolation

Author: tshortli

lib/SILGen/SILGen.cpp

@@ -503,11 +503,6 @@ FuncDecl *SILGenModule::getAsyncMainDrainQueue() {
                                     "_asyncMainDrainQueue");
 }
 
-FuncDecl *SILGenModule::getGetMainExecutor() {
-  return lookupConcurrencyIntrinsic(getASTContext(), GetMainExecutor,
-                                    "_getMainExecutor");
-}
-
 FuncDecl *SILGenModule::getSwiftJobRun() {
   return lookupConcurrencyIntrinsic(getASTContext(), SwiftJobRun,
                                     "_swiftJobRun");

lib/SILGen/SILGen.h

@@ -583,8 +583,6 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
 
   /// Retrieve the _Concurrency._asyncMainDrainQueue intrinsic.
   FuncDecl *getAsyncMainDrainQueue();
-  /// Retrieve the _Concurrency._getMainExecutor intrinsic.
-  FuncDecl *getGetMainExecutor();
   /// Retrieve the _Concurrency._swiftJobRun intrinsic.
   FuncDecl *getSwiftJobRun();
   // Retrieve the _SwiftConcurrencyShims.exit intrinsic.

lib/SILGen/SILGenProlog.cpp

@@ -1449,36 +1449,12 @@ void SILGenFunction::emitProlog(
 }
 
 SILValue SILGenFunction::emitMainExecutor(SILLocation loc) {
-  // Get main executor
-  FuncDecl *getMainExecutorFuncDecl = SGM.getGetMainExecutor();
-  if (!getMainExecutorFuncDecl) {
-    // If it doesn't exist due to an SDK-compiler mismatch, we can conjure one
-    // up instead of crashing:
-    // @available(SwiftStdlib 5.1, *)
-    // @_silgen_name("swift_task_getMainExecutor")
-    // internal func _getMainExecutor() -> Builtin.Executor
-    auto &ctx = getASTContext();
-
-    ParameterList *emptyParams = ParameterList::createEmpty(ctx);
-    getMainExecutorFuncDecl = FuncDecl::createImplicit(
-        ctx, StaticSpellingKind::None,
-        DeclName(
-            ctx,
-            DeclBaseName(ctx.getIdentifier("_getMainExecutor")),
-            /*Arguments*/ emptyParams),
-        {}, /*async*/ false, /*throws*/ false, /*thrownType*/Type(), {},
-        emptyParams, ctx.TheExecutorType,
-        getModule().getSwiftModule());
-    getMainExecutorFuncDecl->getAttrs().add(
-        new (ctx) SILGenNameAttr("swift_task_getMainExecutor", /*raw*/ false,
-                                 /*implicit*/ true));
-  }
+  auto &ctx = getASTContext();
+  auto builtinName = ctx.getIdentifier(
+      getBuiltinName(BuiltinValueKind::BuildMainActorExecutorRef));
+  auto resultType = SILType::getPrimitiveObjectType(ctx.TheExecutorType);
 
-  auto fn = SGM.getFunction(
-      SILDeclRef(getMainExecutorFuncDecl, SILDeclRef::Kind::Func),
-      NotForDefinition);
-  SILValue fnRef = B.createFunctionRefFor(loc, fn);
-  return B.createApply(loc, fnRef, {}, {});
+  return B.createBuiltin(loc, builtinName, resultType, {}, {});
 }
 
 SILValue SILGenFunction::emitGenericExecutor(SILLocation loc) {

stdlib/public/Concurrency/ExecutorAssertions.swift

@@ -18,7 +18,7 @@ import SwiftShims
 // ==== -----------------------------------------------------------------------
 // MARK: Precondition executors
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension SerialExecutor {
   /// Unconditionally if the current task is executing on the expected serial executor,
   /// and if not crash the program offering information about the executor mismatch.
@@ -35,7 +35,10 @@ extension SerialExecutor {
   /// * In `-Ounchecked` builds, the optimizer may assume that this function is
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -55,7 +58,7 @@ extension SerialExecutor {
   }
 }
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension Actor {
   /// Unconditionally if the current task is executing on the serial executor of the passed in `actor`,
   /// and if not crash the program offering information about the executor mismatch.
@@ -72,7 +75,10 @@ extension Actor {
   /// * In `-Ounchecked` builds, the optimizer may assume that this function is
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public nonisolated func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -92,7 +98,7 @@ extension Actor {
   }
 }
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension GlobalActor {
   /// Unconditionally if the current task is executing on the serial executor of the passed in `actor`,
   /// and if not crash the program offering information about the executor mismatch.
@@ -109,7 +115,10 @@ extension GlobalActor {
   /// * In `-Ounchecked` builds, the optimizer may assume that this function is
   ///   never called. Failure to satisfy that assumption is a serious
   ///   programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public static func preconditionIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -122,7 +131,7 @@ extension GlobalActor {
 // ==== -----------------------------------------------------------------------
 // MARK: Assert executors
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension SerialExecutor {
   /// Performs an executor check in debug builds.
   ///
@@ -136,7 +145,10 @@ extension SerialExecutor {
   /// * In `-Ounchecked` builds, `condition` is not evaluated, but the optimizer
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public func assertIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -156,7 +168,7 @@ extension SerialExecutor {
   }
 }
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension Actor {
   /// Performs an executor check in debug builds.
   ///
@@ -170,7 +182,10 @@ extension Actor {
   /// * In `-Ounchecked` builds, `condition` is not evaluated, but the optimizer
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public nonisolated func assertIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -191,7 +206,7 @@ extension Actor {
   }
 }
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension GlobalActor {
   /// Performs an executor check in debug builds.
   ///
@@ -205,7 +220,10 @@ extension GlobalActor {
   /// * In `-Ounchecked` builds, `condition` is not evaluated, but the optimizer
   ///   may assume that it *always* evaluates to `true`. Failure to satisfy that
   ///   assumption is a serious programming error.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableInEmbedded
   public static func assertIsolated(
       _ message: @autoclosure () -> String = String(),
@@ -218,7 +236,7 @@ extension GlobalActor {
 // ==== -----------------------------------------------------------------------
 // MARK: Assume Executor
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension Actor {
   /// A safe way to synchronously assume that the current execution context belongs to the passed in actor.
   ///
@@ -233,7 +251,10 @@ extension Actor {
   /// if another actor uses the same serial executor--by using that actor's ``Actor/unownedExecutor``
   /// as its own ``Actor/unownedExecutor``--this check will succeed, as from a concurrency safety
   /// perspective, the serial executor guarantees mutual exclusion of those two actors.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  #if !$Embedded
+  @backDeployed(before: SwiftStdlib 5.9)
+  #endif
   @_unavailableFromAsync(message: "express the closure as an explicit function declared on the specified 'actor' instead")
   @_unavailableInEmbedded
   public nonisolated func assumeIsolated<T>(

stdlib/public/Concurrency/MainActor.swift

@@ -99,7 +99,7 @@ extension MainActor {
   }
 }
 
-@available(SwiftStdlib 5.9, *)
+@available(SwiftStdlib 5.1, *)
 extension MainActor {
   /// A safe way to synchronously assume that the current execution context belongs to the MainActor.
   ///
@@ -114,7 +114,8 @@ extension MainActor {
   /// if another actor uses the same serial executor--by using ``MainActor/sharedUnownedExecutor``
   /// as its own ``Actor/unownedExecutor``--this check will succeed, as from a concurrency safety
   /// perspective, the serial executor guarantees mutual exclusion of those two actors.
-  @available(SwiftStdlib 5.9, *)
+  @available(SwiftStdlib 5.1, *)
+  @backDeployed(before: SwiftStdlib 5.9)
   @_unavailableFromAsync(message: "await the call to the @MainActor closure directly")
   public static func assumeIsolated<T>(
       _ operation: @MainActor () throws -> T,

test/Concurrency/Runtime/actor_assume_executor.swift

@@ -100,7 +100,7 @@ final class MainActorEcho {
 
     let echo = MainActorEcho()
 
-    if #available(SwiftStdlib 5.9, *) {
+    if #available(SwiftStdlib 5.1, *) {
       // === MainActor --------------------------------------------------------
 
       tests.test("MainActor.assumeIsolated: assume the main executor, from 'main() async'") {

test/Concurrency/async_main.swift

@@ -80,12 +80,10 @@ func asyncFunc() async {
 // CHECK-SIL-NEXT:  %12 = function_ref @swift_job_run : $@convention(thin) (UnownedJob, UnownedSerialExecutor) -> ()
 // CHECK-SIL-NEXT:  %13 = builtin "convertTaskToJob"(%11 : $Builtin.NativeObject) : $Builtin.Job
 // CHECK-SIL-NEXT:  %14 = struct $UnownedJob (%13 : $Builtin.Job)
-// CHECK-SIL-NEXT:  // function_ref swift_task_getMainExecutor
-// CHECK-SIL-NEXT:  %15 = function_ref @swift_task_getMainExecutor : $@convention(thin) () -> Builtin.Executor
-// CHECK-SIL-NEXT:  %16 = apply %15() : $@convention(thin) () -> Builtin.Executor
-// CHECK-SIL-NEXT:  %17 = struct $UnownedSerialExecutor (%16 : $Builtin.Executor)
-// CHECK-SIL-NEXT:  %18 = apply %12(%14, %17) : $@convention(thin) (UnownedJob, UnownedSerialExecutor) -> ()
+// CHECK-SIL-NEXT:  %15 = builtin "buildMainActorExecutorRef"() : $Builtin.Executor
+// CHECK-SIL-NEXT:  %16 = struct $UnownedSerialExecutor (%15 : $Builtin.Executor)
+// CHECK-SIL-NEXT:  %17 = apply %12(%14, %16) : $@convention(thin) (UnownedJob, UnownedSerialExecutor) -> ()
 // CHECK-SIL-NEXT:  // function_ref swift_task_asyncMainDrainQueue
-// CHECK-SIL-NEXT:  %19 = function_ref @swift_task_asyncMainDrainQueue : $@convention(thin) () -> Never
-// CHECK-SIL-NEXT:  %20 = apply %19() : $@convention(thin) () -> Never
+// CHECK-SIL-NEXT:  %18 = function_ref @swift_task_asyncMainDrainQueue : $@convention(thin) () -> Never
+// CHECK-SIL-NEXT:  %19 = apply %18() : $@convention(thin) () -> Never
 // CHECK-SIL-NEXT:  unreachable

test/SILGen/toplevel_globalactorvars.swift

@@ -5,9 +5,7 @@
 
 // CHECK-LABEL: sil private [ossa] @async_Main
 // CHECK: bb0:
-// CHECK-NEXT: // function_ref
-// CHECK-NEXT: [[GET_MAIN:%.*]] = function_ref @swift_task_getMainExecutor
-// CHECK-NEXT: [[MAIN:%.*]] = apply [[GET_MAIN]]()
+// CHECK-NEXT: [[MAIN:%.*]] = builtin "buildMainActorExecutorRef"() : $Builtin.Executor
 // CHECK-NEXT: [[MAIN_OPTIONAL:%[0-9]+]] = enum $Optional<Builtin.Executor>, #Optional.some!enumelt, [[MAIN]]
 
 actor MyActorImpl {}