Sema: Remove -experimental-one-way-closure-params

Author: slavapestov

include/swift/Basic/Features.def

@@ -254,7 +254,6 @@ EXPERIMENTAL_FEATURE(MoveOnlyTuples, true)
 EXPERIMENTAL_FEATURE(MoveOnlyPartialReinitialization, true)
 EXPERIMENTAL_FEATURE(ConsumeSelfInDeinit, true)
 
-EXPERIMENTAL_FEATURE(OneWayClosureParameters, false)
 EXPERIMENTAL_FEATURE(LayoutPrespecialization, true)
 
 EXPERIMENTAL_FEATURE(AccessLevelOnImport, true)

include/swift/Option/FrontendOptions.td

@@ -1075,10 +1075,6 @@ def experimental_print_full_convention :
           " arguments, regardless of whether they were written in the source."
           " Also requires -use-clang-function-types to be enabled.">;
 
-def experimental_one_way_closure_params :
-  Flag<["-"], "experimental-one-way-closure-params">,
-  HelpText<"Enable experimental support for one-way closure parameters">;
-
 def force_public_linkage : Flag<["-"], "force-public-linkage">,
    HelpText<"Force public linkage for private symbols. Used by LLDB.">;
 

include/swift/Sema/Constraint.h

@@ -155,12 +155,6 @@ enum class ConstraintKind : char {
   /// type). At that point, this constraint will be treated like an `Equal`
   /// constraint.
   OneWayEqual,
-  /// The second type is the type of a function parameter, and the first type
-  /// is the type of a reference to that function parameter within the body.
-  /// Once the second type has been fully determined (and mapped down to a
-  /// concrete type), this constraint will be treated like a 'BindParam'
-  /// constraint.
-  OneWayBindParam,
   /// If there is no contextual info e.g. `_ = { 42 }` default first type
   /// to a second type. This is effectively a `Defaultable` constraint
   /// which one significant difference:
@@ -687,7 +681,6 @@ class Constraint final : public llvm::ilist_node<Constraint>,
     case ConstraintKind::BindOverload:
     case ConstraintKind::OptionalObject:
     case ConstraintKind::OneWayEqual:
-    case ConstraintKind::OneWayBindParam:
     case ConstraintKind::FallbackType:
     case ConstraintKind::UnresolvedMemberChainBase:
     case ConstraintKind::PackElementOf:
@@ -835,8 +828,7 @@ class Constraint final : public llvm::ilist_node<Constraint>,
 
   /// Whether this is a one-way constraint.
   bool isOneWayConstraint() const {
-    return Kind == ConstraintKind::OneWayEqual ||
-        Kind == ConstraintKind::OneWayBindParam;
+    return Kind == ConstraintKind::OneWayEqual;
   }
 
   /// Retrieve the overload choice for an overload-binding constraint.

lib/AST/FeatureSet.cpp

@@ -88,7 +88,6 @@ UNINTERESTING_FEATURE(OldOwnershipOperatorSpellings)
 UNINTERESTING_FEATURE(MoveOnlyEnumDeinits)
 UNINTERESTING_FEATURE(MoveOnlyTuples)
 UNINTERESTING_FEATURE(MoveOnlyPartialReinitialization)
-UNINTERESTING_FEATURE(OneWayClosureParameters)
 UNINTERESTING_FEATURE(LayoutPrespecialization)
 UNINTERESTING_FEATURE(AccessLevelOnImport)
 UNINTERESTING_FEATURE(AllowNonResilientAccessInPackage)

lib/Frontend/CompilerInvocation.cpp

@@ -863,8 +863,6 @@ static bool ParseEnabledFeatureArgs(LangOptions &Opts, ArgList &Args,
     Opts.enableFeature(Feature::NoImplicitCopy);
     Opts.enableFeature(Feature::OldOwnershipOperatorSpellings);
   }
-  if (Args.hasArg(OPT_experimental_one_way_closure_params))
-    Opts.enableFeature(Feature::OneWayClosureParameters);
   if (Args.hasArg(OPT_enable_experimental_forward_mode_differentiation))
     Opts.enableFeature(Feature::ForwardModeDifferentiation);
   if (Args.hasArg(OPT_enable_experimental_additive_arithmetic_derivation))

lib/Sema/CSBindings.cpp

@@ -1950,8 +1950,7 @@ void PotentialBindings::infer(ConstraintSystem &CS,
     break;
   }
 
-  case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam: {
+  case ConstraintKind::OneWayEqual:{
     // Don't produce any bindings if this type variable is on the left-hand
     // side of a one-way binding.
     auto firstType = constraint->getFirstType();

lib/Sema/CSSimplify.cpp

@@ -2181,7 +2181,6 @@ ConstraintSystem::matchTupleTypes(TupleType *tuple1, TupleType *tuple2,
   case ConstraintKind::ValueWitness:
   case ConstraintKind::BridgingConversion:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::FallbackType:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper:
@@ -2553,7 +2552,6 @@ static bool matchFunctionRepresentations(FunctionType::ExtInfo einfo1,
   case ConstraintKind::ValueMember:
   case ConstraintKind::ValueWitness:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::FallbackType:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper:
@@ -3198,7 +3196,6 @@ ConstraintSystem::matchFunctionTypes(FunctionType *func1, FunctionType *func2,
   case ConstraintKind::ValueWitness:
   case ConstraintKind::BridgingConversion:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::FallbackType:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper:
@@ -7134,7 +7131,6 @@ ConstraintSystem::matchTypes(Type type1, Type type2, ConstraintKind kind,
     case ConstraintKind::ValueMember:
     case ConstraintKind::ValueWitness:
     case ConstraintKind::OneWayEqual:
-    case ConstraintKind::OneWayBindParam:
     case ConstraintKind::FallbackType:
     case ConstraintKind::UnresolvedMemberChainBase:
     case ConstraintKind::PropertyWrapper:
@@ -11594,14 +11590,9 @@ ConstraintSystem::simplifyOneWayConstraint(
 
   // Translate this constraint into an equality or bind-parameter constraint,
   // as appropriate.
-  if (kind == ConstraintKind::OneWayEqual) {
-    return matchTypes(first, secondSimplified, ConstraintKind::Equal, flags,
-                      locator);
-  }
-
-  assert(kind == ConstraintKind::OneWayBindParam);
-  return matchTypes(
-      secondSimplified, first, ConstraintKind::BindParam, flags, locator);
+  ASSERT(kind == ConstraintKind::OneWayEqual);
+  return matchTypes(first, secondSimplified, ConstraintKind::Equal, flags,
+                    locator);
 }
 
 ConstraintSystem::SolutionKind
@@ -11844,12 +11835,6 @@ bool ConstraintSystem::resolveClosure(TypeVariableType *typeVar,
   // Determine whether a result builder will be applied.
   auto resultBuilderType = getOpenedResultBuilderTypeFor(*this, locator);
 
-  // Determine whether to introduce one-way constraints between the parameter's
-  // type as seen in the body of the closure and the external parameter
-  // type.
-  bool oneWayConstraints =
-      getASTContext().LangOpts.hasFeature(Feature::OneWayClosureParameters);
-
   auto *paramList = closure->getParameters();
   SmallVector<AnyFunctionType::Param, 4> parameters;
   bool hasIsolatedParam = false;
@@ -11942,19 +11927,6 @@ bool ConstraintSystem::resolveClosure(TypeVariableType *typeVar,
       //  - `Int...` -> `[Int]`,
       //  - `inout Int` -> `@lvalue Int`.
       internalType = param.getParameterType();
-
-      // When there are type variables in the type and we have enabled
-      // one-way constraints, create a fresh type variable to handle the
-      // binding.
-      if (oneWayConstraints && internalType->hasTypeVariable()) {
-        auto *paramLoc =
-            getConstraintLocator(closure, LocatorPathElt::TupleElement(i));
-        auto *typeVar = createTypeVariable(paramLoc, TVO_CanBindToLValue |
-                                                         TVO_CanBindToNoEscape);
-        addConstraint(
-            ConstraintKind::OneWayBindParam, typeVar, internalType, paramLoc);
-        internalType = typeVar;
-      }
     } else {
       auto *paramLoc =
           getConstraintLocator(closure, LocatorPathElt::TupleElement(i));
@@ -11986,13 +11958,8 @@ bool ConstraintSystem::resolveClosure(TypeVariableType *typeVar,
           addConstraint(ConstraintKind::Bind, externalType, paramTy, paramLoc);
       }
 
-      if (oneWayConstraints) {
-        addConstraint(
-            ConstraintKind::OneWayBindParam, typeVar, externalType, paramLoc);
-      } else {
-        addConstraint(
-            ConstraintKind::BindParam, externalType, typeVar, paramLoc);
-      }
+      addConstraint(
+          ConstraintKind::BindParam, externalType, typeVar, paramLoc);
     }
 
     hasIsolatedParam |= param.isIsolated();
@@ -15760,7 +15727,6 @@ ConstraintSystem::addConstraintImpl(ConstraintKind kind, Type first,
     return simplifyPropertyWrapperConstraint(first, second, subflags, locator);
 
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
     return simplifyOneWayConstraint(kind, first, second, subflags, locator);
 
   case ConstraintKind::UnresolvedMemberChainBase:
@@ -16341,7 +16307,6 @@ ConstraintSystem::simplifyConstraint(const Constraint &constraint) {
     return SolutionKind::Unsolved;
 
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
     return simplifyOneWayConstraint(
         constraint.getKind(), constraint.getFirstType(),
         constraint.getSecondType(),

lib/Sema/Constraint.cpp

@@ -75,7 +75,6 @@ Constraint::Constraint(ConstraintKind Kind, Type First, Type Second,
   case ConstraintKind::OpenedExistentialOf:
   case ConstraintKind::OptionalObject:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper:
   case ConstraintKind::BindTupleOfFunctionParams:
@@ -164,7 +163,6 @@ Constraint::Constraint(ConstraintKind Kind, Type First, Type Second, Type Third,
   case ConstraintKind::Disjunction:
   case ConstraintKind::Conjunction:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::FallbackType:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper:
@@ -398,7 +396,6 @@ void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm,
   case ConstraintKind::EscapableFunctionOf: Out << " @escaping type of "; break;
   case ConstraintKind::OpenedExistentialOf: Out << " opened archetype of "; break;
   case ConstraintKind::OneWayEqual: Out << " one-way bind to "; break;
-  case ConstraintKind::OneWayBindParam: Out << " one-way bind param to "; break;
   case ConstraintKind::FallbackType:
     Out << " can fallback to ";
     break;
@@ -679,7 +676,6 @@ gatherReferencedTypeVars(Constraint *constraint,
   case ConstraintKind::LiteralConformsTo:
   case ConstraintKind::TransitivelyConformsTo:
   case ConstraintKind::OneWayEqual:
-  case ConstraintKind::OneWayBindParam:
   case ConstraintKind::FallbackType:
   case ConstraintKind::UnresolvedMemberChainBase:
   case ConstraintKind::PropertyWrapper: