---

yaml
---
r: 341119
b: refs/heads/rxwei-patch-1
c: 8684bae
h: refs/heads/master
i:
  341117: 07c6069
  341115: 27dbf4f
  341111: 4cf900a
  341103: d045017
  341087: c08bd81
  341055: a2705cb
  340991: 70f7c1d

Author: slavapestov

[refs]

@@ -1015,7 +1015,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-08-18-a: b10b1fce14385faa6d44f6b933e95
 refs/heads/rdar-43033749-fix-batch-mode-no-diags-swift-5.0-branch: a14e64eaad30de89f0f5f0b2a782eed7ecdcb255
 refs/heads/revert-19006-error-bridging-integer-type: 8a9065a3696535305ea53fe9b71f91cbe6702019
 refs/heads/revert-19050-revert-19006-error-bridging-integer-type: ecf752d54b05dd0a20f510f0bfa54a3fec3bcaca
-refs/heads/rxwei-patch-1: 8f22da205a579f6fac312d59a7ae52d997d3ec67
+refs/heads/rxwei-patch-1: 8684baedcc932c1dbb2a6e62f7a371191657942a
 refs/heads/shahmishal-patch-1: e58ec0f7488258d42bef51bc3e6d7b3dc74d7b2a
 refs/heads/typelist-existential: 4046359efd541fb5c72d69a92eefc0a784df8f5e
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-08-20-a: 4319ba09e4fb8650ee86061075c74a016b6baab9

branches/rxwei-patch-1/include/swift/AST/DiagnosticsSema.def

@@ -2588,7 +2588,7 @@ ERROR(self_in_mutable_subscript,none,
 ERROR(self_in_parameter,none,
       "'Self' cannot be the type of a function argument in a class", ())
 ERROR(self_in_nested_return,none,
-      "'Self' cannot be the type of a nested return value", ())
+      "'Self' can only appear at the top level of a method result type", ())
 
 //------------------------------------------------------------------------------
 // MARK: Type Check Attributes

branches/rxwei-patch-1/lib/Sema/TypeCheckDecl.cpp

@@ -3204,9 +3204,21 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
         else
           diagnoseSelfTypedParameters(Param->getInterfaceType(), Loc, 1);
       }
-      TypeLoc RTyLoc = FD->getBodyResultTypeLoc();
-      if (RTyLoc.getType())
-        diagnoseSelfTypedParameters(RTyLoc.getType(), RTyLoc.getLoc(), 1);
+
+      auto ResultTy = FD->getResultInterfaceType();
+
+      // For now, DynamicSelfType can only appear at the top level of a
+      // function result type, possibly wrapped in an optional type.
+      if (ResultTy->hasDynamicSelfType()) {
+        if (auto ObjectTy = ResultTy->getOptionalObjectType())
+          ResultTy = ObjectTy;
+        if (!ResultTy->is<DynamicSelfType>()) {
+          auto loc = FD->getBodyResultTypeLoc().getLoc();
+          if (loc.isInvalid())
+            loc = FD->getLoc();
+          TC.diagnose(loc, diag::self_in_nested_return);
+        }
+      }
     }
   }
 

branches/rxwei-patch-1/lib/Sema/TypeCheckGeneric.cpp

@@ -567,15 +567,12 @@ void TypeChecker::validateGenericFuncOrSubscriptSignature(
       decl->getDeclContext()->getGenericSignatureOfContext();
 
   auto params = func ? func->getParameters() : subscr->getIndices();
-  bool hasDynamicSelf = false;
   TypeLoc emptyLoc;
   TypeLoc &resultTyLoc = [&]() -> TypeLoc& {
     if (subscr)
       return subscr->getElementTypeLoc();
-    if (auto fn = dyn_cast<FuncDecl>(func)) {
-      hasDynamicSelf = fn->hasDynamicSelf();
+    if (auto fn = dyn_cast<FuncDecl>(func))
       return fn->getBodyResultTypeLoc();
-    }
     return emptyLoc;
   }();
 
@@ -605,9 +602,8 @@ void TypeChecker::validateGenericFuncOrSubscriptSignature(
     if (!resultTyLoc.isNull() &&
         !(resultTyLoc.getTypeRepr() &&
           isa<OpaqueReturnTypeRepr>(resultTyLoc.getTypeRepr())))
-      validateType(resultTyLoc, resolution, hasDynamicSelf
-                     ? TypeResolverContext::DynamicSelfResult
-                     : TypeResolverContext::FunctionResult);
+      validateType(resultTyLoc, resolution,
+                   TypeResolverContext::FunctionResult);
 
     // Infer requirements from it.
     if (resultTyLoc.getTypeRepr()) {
@@ -658,9 +654,8 @@ void TypeChecker::validateGenericFuncOrSubscriptSignature(
       resultTyLoc.setType(
           getOrCreateOpaqueResultType(resolution, decl, opaqueTy));
     } else {
-      validateType(resultTyLoc, resolution, hasDynamicSelf
-                   ? TypeResolverContext::DynamicSelfResult
-                   : TypeResolverContext::FunctionResult);
+      validateType(resultTyLoc, resolution,
+                   TypeResolverContext::FunctionResult);
     }
   }
 

branches/rxwei-patch-1/lib/Sema/TypeCheckType.cpp

@@ -1284,18 +1284,25 @@ resolveTopLevelIdentTypeComponent(TypeResolution resolution,
   auto DC = resolution.getDeclContext();
 
   // Dynamic 'Self' in the result type of a function body.
-  if (options.getBaseContext() == TypeResolverContext::DynamicSelfResult &&
-      comp->getIdentifier() == ctx.Id_Self) {
-    auto func = cast<FuncDecl>(DC);
-    assert(func->hasDynamicSelf() && "Not marked as having dynamic Self?");
-
-    // FIXME: The passed-in TypeRepr should get 'typechecked' as well.
-    // The issue is though that ComponentIdentTypeRepr only accepts a ValueDecl
-    // while the 'Self' type is more than just a reference to a TypeDecl.
+  if (comp->getIdentifier() == ctx.Id_Self) {
+    switch (options.getBaseContext()) {
+    case TypeResolverContext::FunctionResult: {
+      if (auto *typeDC = DC->getInnermostTypeContext()) {
+        // FIXME: The passed-in TypeRepr should get 'typechecked' as well.
+        // The issue is though that ComponentIdentTypeRepr only accepts a ValueDecl
+        // while the 'Self' type is more than just a reference to a TypeDecl.
+        auto selfType = resolution.mapTypeIntoContext(
+          typeDC->getSelfInterfaceType());
+        if (!typeDC->getSelfClassDecl())
+          return selfType;
+        return DynamicSelfType::get(selfType, ctx);
+      }
 
-    auto selfType = resolution.mapTypeIntoContext(
-      func->getDeclContext()->getSelfInterfaceType());
-    return DynamicSelfType::get(selfType, ctx);
+      break;
+    }
+    default:
+      break;
+    }
   }
 
   auto id = comp->getIdentifier();
@@ -3081,7 +3088,6 @@ Type TypeResolver::resolveImplicitlyUnwrappedOptionalType(
     break;
   case TypeResolverContext::FunctionInput:
   case TypeResolverContext::FunctionResult:
-  case TypeResolverContext::DynamicSelfResult:
   case TypeResolverContext::PatternBindingDecl:
     doDiag = !isDirect;
     break;

branches/rxwei-patch-1/lib/Sema/TypeCheckType.h

@@ -94,10 +94,6 @@ enum class TypeResolverContext : uint8_t {
   /// tuple return values. See also: TypeResolutionFlags::Direct
   FunctionResult,
 
-  /// Whether we are in the result type of a function body that is
-  /// known to produce dynamic Self.
-  DynamicSelfResult,
-
   /// Whether we are in a protocol's where clause
   ProtocolWhereClause,
 
@@ -211,7 +207,6 @@ class TypeResolutionOptions {
     case Context::FunctionInput:
     case Context::VariadicFunctionInput:
     case Context::FunctionResult:
-    case Context::DynamicSelfResult:
     case Context::ProtocolWhereClause:
     case Context::ExtensionBinding:
     case Context::SubscriptDecl:

branches/rxwei-patch-1/test/type/self.swift

@@ -129,10 +129,15 @@ class C {
   }
   func h(j: () -> Self) -> () -> Self {
     // expected-error@-1 {{'Self' cannot be the type of a function argument in a class}}
-    // expected-error@-2 {{'Self' cannot be the type of a nested return value}}
+    // expected-error@-2 {{'Self' can only appear at the top level of a method result type}}
     return { return self }
     // expected-error@-1 {{cannot convert value of type 'C' to closure result type 'Self'}}
   }
+  func i() -> (Self, Self) {}
+  // expected-error@-1 {{'Self' can only appear at the top level of a method result type}}
+
+  func j() -> Self.Type {}
+  // expected-error@-1 {{'Self' can only appear at the top level of a method result type}}
 
   let p0: Self?
   var p1: Self? // expected-error {{'Self' is not available as the type of a mutable property}}