Merge pull request #37158 from ktoso/pick-tasklocals

[cherry-pick 5.5] Task locals revisions

Author: DougGregor

include/swift/ABI/Task.h

@@ -47,7 +47,7 @@ class alignas(2 * alignof(void*)) Job : public HeapObject {
     NextWaitingTaskIndex = 0,
 
     // The Dispatch object header is one pointer and two ints, which is
-    // equvialent to three pointers on 32-bit and two pointers 64-bit. Set the
+    // equivalent to three pointers on 32-bit and two pointers 64-bit. Set the
     // indexes accordingly so that DispatchLinkageIndex points to where Dispatch
     // expects.
     DispatchHasLongObjectHeader = sizeof(void *) == sizeof(int),
@@ -217,14 +217,13 @@ class AsyncTask : public Job {
 
   // ==== Task Local Values ----------------------------------------------------
 
-  void localValuePush(const Metadata *keyType,
+  void localValuePush(const HeapObject *key,
                       /* +1 */ OpaqueValue *value, const Metadata *valueType) {
-    Local.pushValue(this, keyType, value, valueType);
+    Local.pushValue(this, key, value, valueType);
   }
 
-  OpaqueValue* localValueGet(const Metadata *keyType,
-                             TaskLocal::TaskLocalInheritance inherit) {
-    return Local.getValue(this, keyType, inherit);
+  OpaqueValue* localValueGet(const HeapObject *key) {
+    return Local.getValue(this, key);
   }
 
   void localValuePop() {

include/swift/ABI/TaskLocal.h

@@ -34,73 +34,50 @@ class TaskLocal {
 public:
   /// Type of the pointed at `next` task local item.
   enum class NextLinkType : uintptr_t {
-    /// This task is known to be a "terminal" node in the lookup of task locals.
-    /// In other words, even if it had a parent, the parent (and its parents)
-    /// are known to not contain any any more task locals, and thus any further
-    /// search beyond this task.
-    IsTerminal = 0b00,
     /// The storage pointer points at the next TaskLocal::Item in this task.
-    IsNext = 0b01,
+    IsNext = 0b00,
     /// The storage pointer points at a item stored by another AsyncTask.
     ///
     /// Note that this may not necessarily be the same as the task's parent
     /// task -- we may point to a super-parent if we know / that the parent
     /// does not "contribute" any task local values. This is to speed up
     /// lookups by skipping empty parent tasks during get(), and explained
     /// in depth in `createParentLink`.
-    IsParent = 0b11
-  };
-
-  /// Values must match `TaskLocalInheritance` declared in `TaskLocal.swift`.
-  enum class TaskLocalInheritance : uint8_t {
-    /// Default task local value behavior
-    ///
-    /// Values declared with a default-inherited key are accessible from:
-    /// - the current task that has bound the value,
-    /// - any child task of the current task (e.g. created by async let or groups)
-    ///
-    /// Such values are *not* carried through detached tasks.
-    Default = 0,
-
-    /// Special semantics which confine a task's local value to *only* the current
-    /// task. In other words, they ave never inherited by any child task created
-    /// by the current task.
-    ///
-    /// Values declared with a never-inherited key only accessible:
-    /// - specifically from the current task itself
-    ///
-    /// Such values are *not* accessible from child tasks or detached tasks.
-    Never   = 1
+    IsParent = 0b01,
   };
 
   class Item {
   private:
     /// Mask used for the low status bits in a task local chain item.
     static const uintptr_t statusMask = 0x03;
 
-    /// Pointer to the next task local item; be it in this task or in a parent.
-    /// Low bits encode `NextLinkType`.
-    /// Item *next = nullptr;
+    /// Pointer to one of the following:
+    /// - next task local item as OpaqueValue* if it is task-local allocated
+    /// - next task local item as HeapObject* if it is heap allocated "heavy"
+    /// - the parent task's TaskLocal::Storage
+    ///
+    /// Low bits encode `NextLinkType`, based on which the type of the pointer
+    /// is determined.
     uintptr_t next;
 
   public:
     /// The type of the key with which this value is associated.
-    const Metadata *keyType;
+    const HeapObject *key;
     /// The type of the value stored by this item.
     const Metadata *valueType;
 
     // Trailing storage for the value itself. The storage will be
     // uninitialized or contain an instance of \c valueType.
 
-  private:
+  protected:
     explicit Item()
       : next(0),
-        keyType(nullptr),
+        key(nullptr),
         valueType(nullptr) {}
 
-    explicit Item(const Metadata *keyType, const Metadata *valueType)
+    explicit Item(const HeapObject *key, const Metadata *valueType)
       : next(0),
-        keyType(keyType),
+        key(key),
         valueType(valueType) {}
 
   public:
@@ -116,7 +93,7 @@ class TaskLocal {
     static Item *createParentLink(AsyncTask *task, AsyncTask *parent);
 
     static Item *createLink(AsyncTask *task,
-                            const Metadata *keyType,
+                            const HeapObject *key,
                             const Metadata *valueType);
 
     void destroy(AsyncTask *task);
@@ -125,13 +102,13 @@ class TaskLocal {
       return reinterpret_cast<Item *>(next & ~statusMask);
     }
 
-    NextLinkType getNextLinkType() {
+    NextLinkType getNextLinkType() const {
       return static_cast<NextLinkType>(next & statusMask);
     }
 
     /// Item does not contain any actual value, and is only used to point at
     /// a specific parent item.
-    bool isEmpty() {
+    bool isEmpty() const {
       return !valueType;
     }
 
@@ -144,6 +121,7 @@ class TaskLocal {
     /// Compute the offset of the storage from the base of the item.
     static size_t storageOffset(const Metadata *valueType) {
       size_t offset = sizeof(Item);
+
       if (valueType) {
         size_t alignment = valueType->vw_alignment();
         return (offset + alignment - 1) & ~(alignment - 1);
@@ -162,7 +140,6 @@ class TaskLocal {
     }
   };
 
-
   class Storage {
     friend class TaskLocal::Item;
   private:
@@ -202,12 +179,10 @@ class TaskLocal {
     void initializeLinkParent(AsyncTask *task, AsyncTask *parent);
 
     void pushValue(AsyncTask *task,
-                   const Metadata *keyType,
+                   const HeapObject *key,
                    /* +1 */ OpaqueValue *value, const Metadata *valueType);
 
-    OpaqueValue* getValue(AsyncTask *task,
-                          const Metadata *keyType,
-                          TaskLocalInheritance inheritance);
+    OpaqueValue* getValue(AsyncTask *task, const HeapObject *key);
 
     void popValue(AsyncTask *task);
 

include/swift/AST/DiagnosticsSema.def

@@ -5609,6 +5609,11 @@ ERROR(property_wrapper_dynamic_self_type, none,
       "property wrapper %select{wrapped value|projected value}0 cannot have "
       "dynamic Self type", (bool))
 
+ERROR(property_wrapper_var_must_be_static, none,
+      "property %0, must be static because property wrapper %1 can only "
+      "be applied to static properties",
+      (Identifier, Type))
+
 ERROR(property_wrapper_attribute_not_on_property, none,
       "property wrapper attribute %0 can only be applied to a property",
       (Identifier))

include/swift/AST/KnownSDKTypes.def

@@ -40,4 +40,6 @@ KNOWN_SDK_TYPE_DECL(ObjectiveC, ObjCBool, StructDecl, 0)
 KNOWN_SDK_TYPE_DECL(Concurrency, UnsafeContinuation, NominalTypeDecl, 2)
 KNOWN_SDK_TYPE_DECL(Concurrency, MainActor, NominalTypeDecl, 0)
 
+KNOWN_SDK_TYPE_DECL(Concurrency, TaskLocal, ClassDecl, 1)
+
 #undef KNOWN_SDK_TYPE_DECL

include/swift/AST/PropertyWrappers.h

@@ -88,6 +88,10 @@ struct PropertyWrapperTypeInfo {
   /// ability to reason about the enclosing "self".
   SubscriptDecl *enclosingInstanceProjectedSubscript = nullptr;
 
+  /// Forces that the property wrapper must be declared on a static, or
+  /// global–once supported–property.
+  bool requireNoEnclosingInstance = false;
+
   ///
   /// Whether this is a valid property wrapper.
   bool isValid() const {

include/swift/Runtime/Concurrency.h

@@ -303,11 +303,20 @@ bool swift_task_tryAddStatusRecord(TaskStatusRecord *record);
 ///
 /// The given record need not be the last record added to
 /// the task, but the operation may be less efficient if not.
-///s
+///
 /// Returns false if the task has been cancelled.
 SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
 bool swift_task_removeStatusRecord(TaskStatusRecord *record);
 
+/// Signifies whether the current task is in the middle of executing the
+/// operation block of a `with(Throwing)TaskGroup(...) { <operation> }`.
+///
+/// Task local values must use un-structured allocation for values bound in this
+/// scope, as they may be referred to by `group.spawn`-ed tasks and therefore
+/// out-life the scope of a task-local value binding.
+SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
+bool swift_task_hasTaskGroupStatusRecord();
+
 /// Attach a child task to its parent task and return the newly created
 /// `ChildTaskStatusRecord`.
 ///
@@ -339,20 +348,23 @@ SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
 void swift_task_removeCancellationHandler(
     CancellationNotificationStatusRecord *record);
 
+/// Report error about attempting to bind a task-local value from an illegal context.
+SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
+void swift_task_reportIllegalTaskLocalBindingWithinWithTaskGroup(
+    const unsigned char *file, uintptr_t fileLength,
+    bool fileIsASCII, uintptr_t line);
+
 /// Get a task local value from the passed in task. Its Swift signature is
 ///
 /// \code
 /// func _taskLocalValueGet<Key>(
 ///   _ task: Builtin.NativeObject,
-///   keyType: Any.Type /*Key.Type*/,
-///   inheritance: UInt8/*TaskLocalInheritance*/
+///   keyType: Any.Type /*Key.Type*/
 /// ) -> UnsafeMutableRawPointer? where Key: TaskLocalKey
 /// \endcode
 SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
 OpaqueValue*
-swift_task_localValueGet(AsyncTask* task,
-                         const Metadata *keyType,
-                         TaskLocal::TaskLocalInheritance inheritance);
+swift_task_localValueGet(AsyncTask* task, const HeapObject *key);
 
 /// Add a task local value to the passed in task.
 ///
@@ -369,7 +381,7 @@ swift_task_localValueGet(AsyncTask* task,
 /// \endcode
 SWIFT_EXPORT_FROM(swift_Concurrency) SWIFT_CC(swift)
 void swift_task_localValuePush(AsyncTask* task,
-                         const Metadata *keyType,
+                         const HeapObject *key,
                          /* +1 */ OpaqueValue *value,
                          const Metadata *valueType);
 

lib/Sema/TypeCheckPropertyWrapper.cpp

@@ -244,6 +244,24 @@ findSuitableWrapperInit(ASTContext &ctx, NominalTypeDecl *nominal,
   return viableInitializers.empty() ? nullptr : viableInitializers.front();
 }
 
+/// Returns true if the enclosingInstance parameter is `Never`,
+/// implying that there should be NO enclosing instance.
+static bool enclosingInstanceTypeIsNever(ASTContext &ctx, SubscriptDecl *subscript) {
+  if (!subscript)
+    return false;
+
+  ParameterList *indices = subscript->getIndices();
+  assert(indices && indices->size() > 0);
+
+  ParamDecl *param = indices->get(0);
+  if (param->getArgumentName() != ctx.Id_enclosingInstance)
+    return false;
+
+  auto paramTy = param->getType();
+  auto neverTy = ctx.getNeverType();
+  return neverTy->isEqual(paramTy);
+}
+
 /// Determine whether we have a suitable static subscript to which we
 /// can pass along the enclosing self + key-paths.
 static SubscriptDecl *findEnclosingSelfSubscript(ASTContext &ctx,
@@ -385,6 +403,16 @@ PropertyWrapperTypeInfoRequest::evaluate(
     }
   }
 
+  result.requireNoEnclosingInstance =
+      enclosingInstanceTypeIsNever(ctx, result.enclosingInstanceWrappedSubscript);
+//  if (requireNoEnclosingInstance) { //  && !valueVar->isStatic()) {
+//    // this means that the property wrapper must be declared on a static property
+//    valueVar->diagnose(
+//        diag::property_wrapper_var_must_be_static, valueVar->getName());
+//    return PropertyWrapperTypeInfo();
+//    result
+//  }
+
   bool hasInvalidDynamicSelf = false;
   if (result.projectedValueVar &&
       result.projectedValueVar->getValueInterfaceType()->hasDynamicSelfType()) {
@@ -439,6 +467,18 @@ AttachedPropertyWrappersRequest::evaluate(Evaluator &evaluator,
       continue;
     }
 
+//    // If the property wrapper requested an `_enclosingInstance: Never`
+//    // it must be declared as static. TODO: or global once we allow wrappers on top-level code
+//    auto wrappedInfo = var->getPropertyWrapperTypeInfo();
+//    if (wrappedInfo.requireNoEnclosingInstance) {
+//      if (!var->isStatic()) {
+//        ctx.Diags.diagnose(var->getLocation(),
+//                           diag::property_wrapper_var_must_be_static,
+//                           var->getName());
+//        continue;
+//      }
+//    }
+
     // Check that the variable is part of a single-variable pattern.
     auto binding = var->getParentPatternBinding();
     if (binding && binding->getSingleVar() != var) {
@@ -508,7 +548,7 @@ AttachedPropertyWrappersRequest::evaluate(Evaluator &evaluator,
         continue;
       }
     }
-    
+
     result.push_back(mutableAttr);
   }
 
@@ -601,6 +641,20 @@ PropertyWrapperBackingPropertyTypeRequest::evaluate(
     wrappedValue->setInterfaceType(computeWrappedValueType(var, type));
   }
 
+  {
+    auto *nominal = type->getDesugaredType()->getAnyNominal();
+    if (auto wrappedInfo = nominal->getPropertyWrapperTypeInfo()) {
+      if (wrappedInfo.requireNoEnclosingInstance &&
+          !var->isStatic()) {
+        ctx.Diags.diagnose(var->getNameLoc(),
+                           diag::property_wrapper_var_must_be_static,
+                           var->getName(), type);
+        // TODO: fixit insert static?
+        return Type();
+      }
+    }
+  }
+
   return type;
 }
 

stdlib/public/CompatibilityOverride/CompatibilityOverrideConcurrency.def

@@ -183,19 +183,25 @@ OVERRIDE_TASK_GROUP(taskGroup_addPending, bool,
                     swift::, (TaskGroup *group, bool unconditionally),
                     (group, unconditionally))
 
+
+OVERRIDE_TASK_LOCAL(task_reportIllegalTaskLocalBindingWithinWithTaskGroup, void,
+                    SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift), swift::,
+                    (const unsigned char *file, uintptr_t fileLength,
+                        bool fileIsASCII, uintptr_t line),
+                    (file, fileLength, fileIsASCII, line))
+
 OVERRIDE_TASK_LOCAL(task_localValuePush, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::,
-                    (AsyncTask *task, const Metadata *keyType,
+                    (AsyncTask *task, const HeapObject *key,
                      OpaqueValue *value, const Metadata *valueType),
-                    (task, keyType, value, valueType))
+                    (task, key, value, valueType))
 
 OVERRIDE_TASK_LOCAL(task_localValueGet, OpaqueValue *,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::,
-                    (AsyncTask *task, const Metadata *keyType,
-                     TaskLocal::TaskLocalInheritance inheritance),
-                    (task, keyType, inheritance))
+                    (AsyncTask *task, const HeapObject *key),
+                    (task, key))
 
 OVERRIDE_TASK_LOCAL(task_localValuePop, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
@@ -213,6 +219,10 @@ OVERRIDE_TASK_STATUS(task_removeStatusRecord, bool,
                      SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                      swift::, (TaskStatusRecord *record), (record))
 
+OVERRIDE_TASK_STATUS(task_hasTaskGroupStatusRecord, bool,
+                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
+                     swift::, , )
+
 OVERRIDE_TASK_STATUS(task_attachChild, ChildTaskStatusRecord *,
                      SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                      swift::, (AsyncTask *child), (child))