[6.0] Add support for sending

include/swift/ABI/MetadataValues.h

@@ -1198,7 +1198,7 @@ class TargetExtendedFunctionTypeFlags {
     IsolatedAny            = 0x00000002U,
 
     // Values if we have a transferring result.
-    HasTransferringResult  = 0x00000010U,
+    HasSendingResult  = 0x00000010U,
 
     /// A InvertibleProtocolSet in the high bits.
     InvertedProtocolshift = 16,
@@ -1228,10 +1228,10 @@ class TargetExtendedFunctionTypeFlags {
   }
 
   const TargetExtendedFunctionTypeFlags<int_type>
-  withTransferringResult(bool newValue = true) const {
+  withSendingResult(bool newValue = true) const {
     return TargetExtendedFunctionTypeFlags<int_type>(
-        (Data & ~HasTransferringResult) |
-        (newValue ? HasTransferringResult : 0));
+        (Data & ~HasSendingResult) |
+        (newValue ? HasSendingResult : 0));
   }
 
   const TargetExtendedFunctionTypeFlags<int_type>
@@ -1247,8 +1247,8 @@ class TargetExtendedFunctionTypeFlags {
     return (Data & IsolationMask) == IsolatedAny;
   }
 
-  bool hasTransferringResult() const {
-    return bool(Data & HasTransferringResult);
+  bool hasSendingResult() const {
+    return bool(Data & HasSendingResult);
   }
 
   int_type getIntValue() const {
@@ -1295,7 +1295,7 @@ class TargetParameterTypeFlags {
     AutoClosureMask       = 0x100,
     NoDerivativeMask      = 0x200,
     IsolatedMask          = 0x400,
-    TransferringMask      = 0x800,
+    SendingMask           = 0x800,
   };
   int_type Data;
 
@@ -1335,17 +1335,17 @@ class TargetParameterTypeFlags {
   }
 
   constexpr TargetParameterTypeFlags<int_type>
-  withTransferring(bool isTransferring) const {
+  withSending(bool isSending) const {
     return TargetParameterTypeFlags<int_type>(
-        (Data & ~TransferringMask) | (isTransferring ? TransferringMask : 0));
+        (Data & ~SendingMask) | (isSending ? SendingMask : 0));
   }
 
   bool isNone() const { return Data == 0; }
   bool isVariadic() const { return Data & VariadicMask; }
   bool isAutoClosure() const { return Data & AutoClosureMask; }
   bool isNoDerivative() const { return Data & NoDerivativeMask; }
   bool isIsolated() const { return Data & IsolatedMask; }
-  bool isTransferring() const { return Data & TransferringMask; }
+  bool isSending() const { return Data & SendingMask; }
 
   ParameterOwnership getOwnership() const {
     return (ParameterOwnership)(Data & OwnershipMask);

include/swift/AST/ASTBridging.h

@@ -1552,6 +1552,7 @@ enum ENUM_EXTENSIBILITY_ATTR(open) BridgedAttributedTypeSpecifier : size_t {
   BridgedAttributedTypeSpecifierIsolated,
   BridgedAttributedTypeSpecifierResultDependsOn,
   BridgedAttributedTypeSpecifierTransferring,
+  BridgedAttributedTypeSpecifierSending,
 };
 
 SWIFT_NAME("BridgedUnqualifiedIdentTypeRepr.createParsed(_:loc:name:)")

include/swift/AST/Builtins.def

@@ -884,7 +884,7 @@ BUILTIN_MISC_OPERATION_WITH_SILGEN(GetCurrentAsyncTask, "getCurrentAsyncTask", "
 BUILTIN_MISC_OPERATION_WITH_SILGEN(CancelAsyncTask, "cancelAsyncTask", "", Special)
 
 /// startAsyncLet()<T>: (
-///     __owned @escaping () async throws -> transferring T
+///     __owned @escaping () async throws -> sending T
 /// ) -> Builtin.RawPointer
 ///
 /// DEPRECATED. startAsyncLetWithLocalBuffer is used instead.
@@ -894,7 +894,7 @@ BUILTIN_MISC_OPERATION_WITH_SILGEN(CancelAsyncTask, "cancelAsyncTask", "", Speci
 BUILTIN_MISC_OPERATION(StartAsyncLet, "startAsyncLet", "", Special)
 
 /// startAsyncLetWithLocalBuffer()<T>: (
-///     __owned @escaping () async throws -> transferring T,
+///     __owned @escaping () async throws -> sending T,
 ///     _ resultBuf: Builtin.RawPointer
 /// ) -> Builtin.RawPointer
 ///

include/swift/AST/Decl.h

@@ -532,8 +532,8 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     /// analysis.
     HasTopLevelLocalContextCaptures : 1,
 
-    /// Set to true if this FuncDecl has a transferring result.
-    HasTransferringResult : 1
+    /// Set to true if this FuncDecl has a 'sending' result.
+    HasSendingResult : 1
   );
 
   SWIFT_INLINE_BITFIELD(AccessorDecl, FuncDecl, 4 + 1 + 1,
@@ -6647,8 +6647,8 @@ class ParamDecl : public VarDecl {
     /// Whether or not this paramater is '_resultDependsOn'
     IsResultDependsOn = 1 << 3,
 
-    /// Whether or not this parameter is 'transferring'.
-    IsTransferring = 1 << 4,
+    /// Whether or not this parameter is 'sending'.
+    IsSending = 1 << 4,
   };
 
   /// The type repr and 3 bits used for flags.
@@ -6902,16 +6902,14 @@ class ParamDecl : public VarDecl {
       removeFlag(Flag::IsIsolated);
   }
 
-  /// Whether or not this parameter is marked with 'transferring'.
-  bool isTransferring() const {
-    return getOptions().contains(Flag::IsTransferring);
-  }
+  /// Whether or not this parameter is marked with 'sending'.
+  bool isSending() const { return getOptions().contains(Flag::IsSending); }
 
-  void setTransferring(bool value = true) {
+  void setSending(bool value = true) {
     if (value)
-      addFlag(Flag::IsTransferring);
+      addFlag(Flag::IsSending);
     else
-      removeFlag(Flag::IsTransferring);
+      removeFlag(Flag::IsSending);
   }
 
   /// Whether or not this parameter is marked with '_const'.
@@ -7940,7 +7938,7 @@ class FuncDecl : public AbstractFunctionDecl {
     Bits.FuncDecl.IsStaticComputed = false;
     Bits.FuncDecl.IsStatic = false;
     Bits.FuncDecl.HasTopLevelLocalContextCaptures = false;
-    Bits.FuncDecl.HasTransferringResult = false;
+    Bits.FuncDecl.HasSendingResult = false;
   }
 
   void setResultInterfaceType(Type type);
@@ -8097,14 +8095,12 @@ class FuncDecl : public AbstractFunctionDecl {
     Bits.FuncDecl.ForcedStaticDispatch = flag;
   }
 
-  /// Returns true if this FuncDecl has a transferring result... returns false
+  /// Returns true if this FuncDecl has a sending result... returns false
   /// otherwise.
-  bool hasTransferringResult() const {
-    return Bits.FuncDecl.HasTransferringResult;
-  }
+  bool hasSendingResult() const { return Bits.FuncDecl.HasSendingResult; }
 
-  void setTransferringResult(bool newValue = true) {
-    Bits.FuncDecl.HasTransferringResult = newValue;
+  void setSendingResult(bool newValue = true) {
+    Bits.FuncDecl.HasSendingResult = newValue;
   }
 
   static bool classof(const Decl *D) {

include/swift/AST/DiagnosticsParse.def

@@ -2207,6 +2207,16 @@ ERROR(transferring_after_parameter_specifier,none,
       "'transferring' must be placed before specifier '%0'", (StringRef))
 ERROR(transferring_repeated,none,
       "parameter may have at most one 'transferring' specifier", ())
+ERROR(sending_before_parameter_specifier,none,
+      "'sending' must be placed after specifier '%0'", (StringRef))
+ERROR(sending_repeated,none,
+      "parameter may have at most one 'sending' specifier", ())
+ERROR(sending_and_transferring_used_together,none,
+      "'transferring' and 'sending' may not be used together", ())
+WARNING(transferring_is_now_sendable,none,
+        "'transferring' has been renamed to 'sending' and the 'transferring' spelling will be removed shortly",
+        ())
+
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/DiagnosticsSIL.def

@@ -990,14 +990,14 @@ NOTE(regionbasedisolation_named_transfer_non_transferrable, none,
 NOTE(regionbasedisolation_named_transfer_non_transferrable_callee, none,
       "sending %1%0 to %2 %3 %4 risks causing data races between %2 and %5 uses",
       (Identifier, StringRef, ActorIsolation, DescriptiveDeclKind, DeclName, StringRef))
-NOTE(regionbasedisolation_named_transfer_into_transferring_param, none,
-     "%0%1 is passed as a transferring parameter; Uses in callee may race with later %0uses",
+NOTE(regionbasedisolation_named_transfer_into_sending_param, none,
+     "%0%1 is passed as a 'sending' parameter; Uses in callee may race with later %0uses",
      (StringRef, Identifier))
 NOTE(regionbasedisolation_named_notransfer_transfer_into_result, none,
-     "%0%1 cannot be a transferring result. %2 uses may race with caller uses",
+     "%0%1 cannot be a 'sending' result. %2 uses may race with caller uses",
      (StringRef, Identifier, StringRef))
-NOTE(regionbasedisolation_named_stronglytransferred_binding, none,
-      "%0 used after being passed as a transferring parameter; Later uses could race",
+NOTE(regionbasedisolation_named_value_used_after_explicit_sending, none,
+      "%0 used after being passed as a 'sending' parameter; Later uses could race",
       (Identifier))
 NOTE(regionbasedisolation_named_isolated_closure_yields_race, none,
       "%0%1 is captured by a %2 closure. %2 uses in closure may race against later %3 uses",

include/swift/AST/DiagnosticsSema.def

@@ -7933,17 +7933,23 @@ ERROR(lifetime_dependence_cannot_infer_ambiguous_candidate, none,
        "Escapable",
        ())
 
- //===----------------------------------------------------------------------===//
- //                             MARK: Transferring
- //===----------------------------------------------------------------------===//
-
- ERROR(transferring_unsupported_param_specifier, none,
-       "'%0' cannot be applied to a 'transferring' parameter", (StringRef))
+//===----------------------------------------------------------------------===//
+//                             MARK: Transferring
+//===----------------------------------------------------------------------===//
 
- ERROR(transferring_only_on_parameters_and_results, none,
-       "'transferring' may only be used on parameters and results", ())
- ERROR(transferring_cannot_be_applied_to_tuple_elt, none,
-       "'transferring' cannot be applied to tuple elements", ())
+ERROR(transferring_unsupported_param_specifier, none,
+      "'%0' cannot be applied to a 'transferring' parameter", (StringRef))
+
+ERROR(transferring_only_on_parameters_and_results, none,
+      "'transferring' may only be used on parameters and results", ())
+ERROR(transferring_cannot_be_applied_to_tuple_elt, none,
+      "'transferring' cannot be applied to tuple elements", ())
+ERROR(sending_unsupported_param_specifier, none,
+      "'%0' cannot be applied to a 'sending' parameter", (StringRef))
+ERROR(sending_only_on_parameters_and_results, none,
+      "'sending' may only be used on parameters and results", ())
+ERROR(sending_cannot_be_applied_to_tuple_elt, none,
+      "'sending' cannot be applied to tuple elements", ())
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/ExtInfo.h

@@ -438,8 +438,8 @@ class ASTExtInfoBuilder {
   // If bits are added or removed, then TypeBase::NumAFTExtInfoBits
   // and NumMaskBits must be updated, and they must match.
   //
-  //   |representation|noEscape|concurrent|async|throws|isolation|differentiability| TransferringResult |
-  //   |    0 .. 3    |    4   |    5     |  6  |   7  | 8 .. 10 |     11 .. 13    |         14         |
+  //   |representation|noEscape|concurrent|async|throws|isolation|differentiability| SendingResult |
+  //   |    0 .. 3    |    4   |    5     |  6  |   7  | 8 .. 10 |     11 .. 13    |         14    |
   //
   enum : unsigned {
     RepresentationMask = 0xF << 0,
@@ -451,7 +451,7 @@ class ASTExtInfoBuilder {
     IsolationMask = 0x7 << IsolationMaskOffset,
     DifferentiabilityMaskOffset = 11,
     DifferentiabilityMask = 0x7 << DifferentiabilityMaskOffset,
-    TransferringResultMask = 1 << 14,
+    SendingResultMask = 1 << 14,
     NumMaskBits = 15
   };
 
@@ -501,14 +501,14 @@ class ASTExtInfoBuilder {
                     Type thrownError, DifferentiabilityKind diffKind,
                     const clang::Type *type, FunctionTypeIsolation isolation,
                     LifetimeDependenceInfo lifetimeDependenceInfo,
-                    bool transferringResult)
+                    bool sendingResult)
       : ASTExtInfoBuilder(
             ((unsigned)rep) | (isNoEscape ? NoEscapeMask : 0) |
                 (throws ? ThrowsMask : 0) |
                 (((unsigned)diffKind << DifferentiabilityMaskOffset) &
                  DifferentiabilityMask) |
                 (unsigned(isolation.getKind()) << IsolationMaskOffset) |
-                (transferringResult ? TransferringResultMask : 0),
+                (sendingResult ? SendingResultMask : 0),
             ClangTypeInfo(type), isolation.getOpaqueType(), thrownError,
             lifetimeDependenceInfo) {}
 
@@ -530,9 +530,7 @@ class ASTExtInfoBuilder {
 
   constexpr bool isThrowing() const { return bits & ThrowsMask; }
 
-  constexpr bool hasTransferringResult() const {
-    return bits & TransferringResultMask;
-  }
+  constexpr bool hasSendingResult() const { return bits & SendingResultMask; }
 
   constexpr DifferentiabilityKind getDifferentiabilityKind() const {
     return DifferentiabilityKind((bits & DifferentiabilityMask) >>
@@ -644,12 +642,10 @@ class ASTExtInfoBuilder {
     return withThrows(true, Type());
   }
 
-  [[nodiscard]] ASTExtInfoBuilder
-  withTransferringResult(bool transferring = true) const {
-    return ASTExtInfoBuilder(transferring ? (bits | TransferringResultMask)
-                                          : (bits & ~TransferringResultMask),
-                             clangTypeInfo, globalActor, thrownError,
-                             lifetimeDependenceInfo);
+  [[nodiscard]] ASTExtInfoBuilder withSendingResult(bool sending = true) const {
+    return ASTExtInfoBuilder(
+        sending ? (bits | SendingResultMask) : (bits & ~SendingResultMask),
+        clangTypeInfo, globalActor, thrownError, lifetimeDependenceInfo);
   }
 
   [[nodiscard]]
@@ -765,9 +761,7 @@ class ASTExtInfo {
 
   constexpr bool isThrowing() const { return builder.isThrowing(); }
 
-  constexpr bool hasTransferringResult() const {
-    return builder.hasTransferringResult();
-  }
+  constexpr bool hasSendingResult() const { return builder.hasSendingResult(); }
 
   constexpr DifferentiabilityKind getDifferentiabilityKind() const {
     return builder.getDifferentiabilityKind();
@@ -838,9 +832,8 @@ class ASTExtInfo {
     return builder.withAsync(async).build();
   }
 
-  [[nodiscard]] ASTExtInfo
-  withTransferringResult(bool transferring = true) const {
-    return builder.withTransferringResult(transferring).build();
+  [[nodiscard]] ASTExtInfo withSendingResult(bool sending = true) const {
+    return builder.withSendingResult(sending).build();
   }
 
   [[nodiscard]]

include/swift/AST/PrintOptions.h

@@ -382,8 +382,8 @@ struct PrintOptions {
   /// Suppress 'isolated' and '#isolation' on isolated parameters with optional type.
   bool SuppressOptionalIsolatedParams = false;
 
-  /// Suppress 'transferring' on arguments and results.
-  bool SuppressTransferringArgsAndResults = false;
+  /// Suppress 'sending' on arguments and results.
+  bool SuppressSendingArgsAndResults = false;
 
   /// Suppress Noncopyable generics.
   bool SuppressNoncopyableGenerics = false;

include/swift/AST/TypeAttr.def

@@ -105,7 +105,7 @@ SIMPLE_SIL_TYPE_ATTR(captures_generics, CapturesGenerics)
 // Used at the SIL level to mark a type as moveOnly.
 SIMPLE_SIL_TYPE_ATTR(moveOnly, MoveOnly)
 SIMPLE_SIL_TYPE_ATTR(sil_isolated, SILIsolated)
-SIMPLE_SIL_TYPE_ATTR(sil_transferring, SILTransferring)
+SIMPLE_SIL_TYPE_ATTR(sil_sending, SILSending)
 
 // SIL metatype attributes.
 SIMPLE_SIL_TYPE_ATTR(thin, Thin)

include/swift/AST/TypeRepr.h

@@ -1116,7 +1116,8 @@ class SpecifierTypeRepr : public TypeRepr {
            T->getKind() == TypeReprKind::CompileTimeConst ||
            T->getKind() == TypeReprKind::ResultDependsOn ||
            T->getKind() == TypeReprKind::LifetimeDependentReturn ||
-           T->getKind() == TypeReprKind::Transferring;
+           T->getKind() == TypeReprKind::Transferring ||
+           T->getKind() == TypeReprKind::Sending;
   }
   static bool classof(const SpecifierTypeRepr *T) { return true; }
 
@@ -1217,6 +1218,21 @@ class TransferringTypeRepr : public SpecifierTypeRepr {
   static bool classof(const TransferringTypeRepr *T) { return true; }
 };
 
+/// A sending type.
+/// \code
+///   x : sending Int
+/// \endcode
+class SendingTypeRepr : public SpecifierTypeRepr {
+public:
+  SendingTypeRepr(TypeRepr *Base, SourceLoc Loc)
+      : SpecifierTypeRepr(TypeReprKind::Sending, Base, Loc) {}
+
+  static bool classof(const TypeRepr *T) {
+    return T->getKind() == TypeReprKind::Sending;
+  }
+  static bool classof(const SendingTypeRepr *T) { return true; }
+};
+
 /// A TypeRepr for a known, fixed type.
 ///
 /// Fixed type representations should be used sparingly, in places
@@ -1618,6 +1634,7 @@ inline bool TypeRepr::isSimple() const {
   case TypeReprKind::SILBox:
   case TypeReprKind::Isolated:
   case TypeReprKind::Transferring:
+  case TypeReprKind::Sending:
   case TypeReprKind::Placeholder:
   case TypeReprKind::CompileTimeConst:
   case TypeReprKind::ResultDependsOn:

include/swift/AST/TypeReprNodes.def

@@ -72,6 +72,7 @@ ABSTRACT_TYPEREPR(Specifier, TypeRepr)
   SPECIFIER_TYPEREPR(CompileTimeConst, SpecifierTypeRepr)
   SPECIFIER_TYPEREPR(ResultDependsOn, SpecifierTypeRepr)
   SPECIFIER_TYPEREPR(Transferring, SpecifierTypeRepr)
+  SPECIFIER_TYPEREPR(Sending, SpecifierTypeRepr)
 TYPEREPR(Fixed, TypeRepr)
 TYPEREPR(SILBox, TypeRepr)
 TYPEREPR(Self, TypeRepr)