[embedded] Introduce a new swift_taskGroup_initializeWithOptions runtime entrypoint

Author: kubamracek

include/swift/ABI/MetadataValues.h

@@ -2792,10 +2792,6 @@ class TaskGroupFlags : public FlagSet<uint32_t> {
     /// Request the TaskGroup to immediately release completed tasks,
     /// and not store their results. This also effectively disables `next()`.
     TaskGroup_DiscardResults = 8,
-    /// The `Metadata *T` in swift_taskGroup_initialize and in
-    /// swift_taskGroup_initializeWithFlags pointer is actually a
-    /// TaskOptionRecord pointer. Used only in Embedded Swift.
-    TaskGroup_MetadataAsOptionRecord = 9,
   };
 
   explicit TaskGroupFlags(uint32_t bits) : FlagSet(bits) {}
@@ -2804,10 +2800,6 @@ class TaskGroupFlags : public FlagSet<uint32_t> {
   FLAGSET_DEFINE_FLAG_ACCESSORS(TaskGroup_DiscardResults,
                                 isDiscardResults,
                                 setIsDiscardResults)
-
-  FLAGSET_DEFINE_FLAG_ACCESSORS(TaskGroup_MetadataAsOptionRecord,
-                                isMetadataAsOptionRecord,
-                                setIsMetadataAsOptionRecord)
 };
 
 /// Flags for cancellation records.

include/swift/Runtime/Concurrency.h

@@ -215,6 +215,17 @@ void swift_taskGroup_initialize(TaskGroup *group, const Metadata *T);
 SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
 void swift_taskGroup_initializeWithFlags(size_t flags, TaskGroup *group, const Metadata *T);
 
+/// Initialize a `TaskGroup` in the passed `group` memory location.
+/// The caller is responsible for retaining and managing the group's lifecycle.
+///
+/// Its Swift signature is
+///
+/// \code
+/// func swift_taskGroup_initialize(flags: Int, group: Builtin.RawPointer)
+/// \endcode
+SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
+void swift_taskGroup_initializeWithOptions(size_t flags, TaskGroup *group, const Metadata *T, TaskOptionRecord *options);
+
 /// Attach a child task to the parent task's task group record.
 ///
 /// This function MUST be called from the AsyncTask running the task group.

include/swift/Runtime/RuntimeFunctions.def

@@ -2555,7 +2555,7 @@ FUNCTION(TaskRunInline,
          EFFECT(NoEffect),
          UNKNOWN_MEMEFFECTS)
 
-// void swift_taskGroup_initialize(TaskGroup *group);
+// void swift_taskGroup_initialize(TaskGroup *group, const Metadata *T);
 FUNCTION(TaskGroupInitialize,
          swift_taskGroup_initialize, SwiftCC,
          ConcurrencyAvailability,
@@ -2565,7 +2565,7 @@ FUNCTION(TaskGroupInitialize,
          EFFECT(Concurrency),
          UNKNOWN_MEMEFFECTS)
 
-// void swift_taskGroup_initializeWithFlags(size_t flags, TaskGroup *group);
+// void swift_taskGroup_initializeWithFlags(size_t flags, TaskGroup *group, const Metadata *T);
 FUNCTION(TaskGroupInitializeWithFlags,
          swift_taskGroup_initializeWithFlags, SwiftCC,
          ConcurrencyDiscardingTaskGroupAvailability,
@@ -2578,6 +2578,20 @@ FUNCTION(TaskGroupInitializeWithFlags,
          EFFECT(Concurrency),
          UNKNOWN_MEMEFFECTS)
 
+// void swift_taskGroup_initializeWithTaskOptions(size_t flags, TaskGroup *group, const Metadata *T, TaskOptionRecord *options);
+FUNCTION(TaskGroupInitializeWithOptions,
+         swift_taskGroup_initializeWithOptions, SwiftCC,
+         ConcurrencyDiscardingTaskGroupAvailability,
+         RETURNS(VoidTy),
+         ARGS(SizeTy,                     // flags
+              Int8PtrTy,                  // group
+              TypeMetadataPtrTy,          // T.Type
+              SwiftTaskOptionRecordPtrTy  // options
+         ),
+         ATTRS(NoUnwind),
+         EFFECT(Concurrency),
+         UNKNOWN_MEMEFFECTS)
+
 // void swift_taskGroup_destroy(TaskGroup *group);
 FUNCTION(TaskGroupDestroy,
          swift_taskGroup_destroy, SwiftCC,

lib/IRGen/GenConcurrency.cpp

@@ -336,38 +336,30 @@ llvm::Value *irgen::emitCreateTaskGroup(IRGenFunction &IGF,
          "createTaskGroup should have a type substitution");
   auto resultType = subs.getReplacementTypes()[0]->getCanonicalType();
 
-  // In desktop Swift, we pass a Metadata pointer as the last argument. In
-  // Embedded Swift, we pass a TaskOptionRecord list, and mark a bit in
-  // groupFlags.
-  llvm::Value *metadataOrTypeOptionRecord;
   if (IGF.IGM.Context.LangOpts.hasFeature(Feature::Embedded)) {
-    metadataOrTypeOptionRecord =
-        llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy);
-    metadataOrTypeOptionRecord = maybeAddEmbeddedSwiftResultTypeInfo(
-        IGF, metadataOrTypeOptionRecord, resultType);
-    llvm::IntegerType *IntPtrTy = IGF.IGM.IntPtrTy;
-    TaskGroupFlags taskgroupFlags(0);
-    taskgroupFlags.setIsMetadataAsOptionRecord(true);
-    auto flagValue = llvm::ConstantInt::get(IGF.IGM.IntPtrTy,
-                                            taskgroupFlags.getOpaqueValue());
-    if (!groupFlags) {
-      groupFlags = flagValue;
-    } else {
-      groupFlags = IGF.Builder.CreateOr(groupFlags, flagValue);
-    }
-  } else {
-    metadataOrTypeOptionRecord = IGF.emitAbstractTypeMetadataRef(resultType);
+    // In Embedded Swift, call swift_taskGroup_initializeWithOptions instead, to
+    // avoid needing a Metadata argument.
+    llvm::Value *options = llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy);
+    llvm::Value *resultTypeMetadata = llvm::ConstantPointerNull::get(IGF.IGM.Int8PtrTy);
+    options = maybeAddEmbeddedSwiftResultTypeInfo(IGF, options, resultType);
+    if (!groupFlags) groupFlags = llvm::ConstantInt::get(IGF.IGM.SizeTy, 0);
+    llvm::CallInst *call = IGF.Builder.CreateCall(IGF.IGM.getTaskGroupInitializeWithOptionsFunctionPointer(),
+                                  {groupFlags, group, resultTypeMetadata, options});
+    call->setDoesNotThrow();
+    call->setCallingConv(IGF.IGM.SwiftCC);
+    return group;
   }
 
+  auto resultTypeMetadata = IGF.emitAbstractTypeMetadataRef(resultType);
+
   llvm::CallInst *call;
   if (groupFlags) {
-    call = IGF.Builder.CreateCall(
-        IGF.IGM.getTaskGroupInitializeWithFlagsFunctionPointer(),
-        {groupFlags, group, metadataOrTypeOptionRecord});
+    call = IGF.Builder.CreateCall(IGF.IGM.getTaskGroupInitializeWithFlagsFunctionPointer(),
+                                  {groupFlags, group, resultTypeMetadata});
   } else {
     call =
         IGF.Builder.CreateCall(IGF.IGM.getTaskGroupInitializeFunctionPointer(),
-                               {group, metadataOrTypeOptionRecord});
+                               {group, resultTypeMetadata});
   }
   call->setDoesNotThrow();
   call->setCallingConv(IGF.IGM.SwiftCC);

stdlib/public/CompatibilityOverride/CompatibilityOverrideConcurrency.def

@@ -300,6 +300,10 @@ OVERRIDE_TASK_GROUP(taskGroup_initializeWithFlags, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::, (size_t flags, TaskGroup *group, const Metadata *T), (flags, group, T))
 
+OVERRIDE_TASK_GROUP(taskGroup_initializeWithOptions, void,
+                    SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
+                    swift::, (size_t flags, TaskGroup *group, const Metadata *T, TaskOptionRecord *options), (flags, group, T, options))
+
 OVERRIDE_TASK_STATUS(taskGroup_attachChild, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::, (TaskGroup *group, AsyncTask *child),

stdlib/public/Concurrency/TaskGroup.cpp

@@ -955,6 +955,8 @@ TaskGroup* TaskGroupTaskStatusRecord::getGroup() {
 // =============================================================================
 // ==== initialize -------------------------------------------------------------
 
+static void _swift_taskGroup_initialize(ResultTypeInfo resultType, size_t rawGroupFlags, TaskGroup *group);
+
 // Initializes into the preallocated _group an actual TaskGroupBase.
 SWIFT_CC(swift)
 static void swift_taskGroup_initializeImpl(TaskGroup *group, const Metadata *T) {
@@ -965,21 +967,27 @@ static void swift_taskGroup_initializeImpl(TaskGroup *group, const Metadata *T)
 SWIFT_CC(swift)
 static void swift_taskGroup_initializeWithFlagsImpl(size_t rawGroupFlags,
                                                     TaskGroup *group, const Metadata *T) {
-  TaskGroupFlags groupFlags(rawGroupFlags);
-  SWIFT_TASK_GROUP_DEBUG_LOG_0(group, "create group, from task:%p; flags: isDiscardingResults=%d",
-                               swift_task_getCurrent(),
-                               groupFlags.isDiscardResults());
-
   ResultTypeInfo resultType;
 #if !SWIFT_CONCURRENCY_EMBEDDED
   resultType.metadata = T;
-  assert(!groupFlags.isMetadataAsOptionRecord());
 #else
-  assert(groupFlags.isMetadataAsOptionRecord());
-  TaskOptionRecord *options = (TaskOptionRecord *)T;
+  swift_unreachable("swift_taskGroup_initializeWithFlags in embedded");
+#endif
+  _swift_taskGroup_initialize(resultType, rawGroupFlags, group);
+}
+
+// Initializes into the preallocated _group an actual instance.
+SWIFT_CC(swift)
+static void swift_taskGroup_initializeWithOptionsImpl(size_t rawGroupFlags, TaskGroup *group, const Metadata *T, TaskOptionRecord *options) {
+  ResultTypeInfo resultType;
+#if !SWIFT_CONCURRENCY_EMBEDDED
+  resultType.metadata = T;
+#endif
+
   for (auto option = options; option; option = option->getParent()) {
     switch (option->getKind()) {
     case TaskOptionRecordKind::ResultTypeInfo: {
+#if SWIFT_CONCURRENCY_EMBEDDED
       auto *typeInfo = cast<ResultTypeInfoTaskOptionRecord>(option);
       resultType = {
           .size = typeInfo->size,
@@ -988,13 +996,26 @@ static void swift_taskGroup_initializeWithFlagsImpl(size_t rawGroupFlags,
           .storeEnumTagSinglePayload = typeInfo->storeEnumTagSinglePayload,
           .destroy = typeInfo->destroy,
       };
+#else
+      swift_unreachable("ResultTypeInfo in non embedded");
+#endif
       break;
     }
     default:
-      swift_unreachable("only ResultTypeInfo expected");
+      break; // ignore unknown records
     }
   }
-#endif
+
+  assert(!resultType.isNull());
+
+  _swift_taskGroup_initialize(resultType, rawGroupFlags, group);
+}
+
+static void _swift_taskGroup_initialize(ResultTypeInfo resultType, size_t rawGroupFlags, TaskGroup *group) {
+  TaskGroupFlags groupFlags(rawGroupFlags);
+  SWIFT_TASK_GROUP_DEBUG_LOG_0(group, "create group, from task:%p; flags: isDiscardingResults=%d",
+                               swift_task_getCurrent(),
+                               groupFlags.isDiscardResults());
 
   TaskGroupBase *impl;
   if (groupFlags.isDiscardResults()) {