AST: Remove FuncDecl::getResultType()

include/swift/AST/Decl.h

@@ -4988,9 +4988,6 @@ class FuncDecl final : public AbstractFunctionDecl,
   TypeLoc &getBodyResultTypeLoc() { return FnRetType; }
   const TypeLoc &getBodyResultTypeLoc() const { return FnRetType; }
 
-  /// Retrieve the result type of this function.
-  Type getResultType() const;
-
   /// Retrieve the result interface type of this function.
   Type getResultInterfaceType() const;
 

lib/AST/ASTVerifier.cpp

@@ -700,7 +700,8 @@ struct ASTNodeBase {};
       auto func = Functions.back();
       Type resultType;
       if (FuncDecl *FD = dyn_cast<FuncDecl>(func)) {
-        resultType = FD->getResultType();
+        resultType = FD->getResultInterfaceType();
+        resultType = ArchetypeBuilder::mapTypeIntoContext(FD, resultType);
       } else if (auto closure = dyn_cast<AbstractClosureExpr>(func)) {
         resultType = closure->getResultType();
       } else {

lib/AST/Decl.cpp

@@ -4458,23 +4458,6 @@ void FuncDecl::setDeserializedSignature(ArrayRef<ParameterList *> BodyParams,
   this->FnRetType = FnRetType;
 }
 
-Type FuncDecl::getResultType() const {
-  if (!hasType())
-    return nullptr;
-
-  Type resultTy = getType();
-  if (resultTy->hasError())
-    return resultTy;
-
-  for (unsigned i = 0, e = getNumParameterLists(); i != e; ++i)
-    resultTy = resultTy->castTo<AnyFunctionType>()->getResult();
-
-  if (!resultTy)
-    resultTy = TupleType::getEmpty(getASTContext());
-
-  return resultTy;
-}
-
 Type FuncDecl::getResultInterfaceType() const {
   if (!hasType())
     return nullptr;

lib/ClangImporter/ImportDecl.cpp

@@ -6488,7 +6488,7 @@ void ClangImporter::Implementation::importAttributes(
   // Map __attribute__((warn_unused_result)).
   if (!ClangDecl->hasAttr<clang::WarnUnusedResultAttr>()) {
     if (auto MD = dyn_cast<FuncDecl>(MappedDecl)) {
-      if (!MD->getResultType()->isVoid()) {
+      if (!MD->getResultInterfaceType()->isVoid()) {
         MD->getAttrs().add(new (C) DiscardableResultAttr(/*implicit*/true));
       }
     }

lib/Index/Index.cpp

@@ -845,7 +845,7 @@ static bool isTestCandidate(ValueDecl *D) {
     return false;
 
   // 3. ...that returns void...
-  Type RetTy = FD->getResultType();
+  Type RetTy = FD->getResultInterfaceType();
   if (RetTy && !RetTy->isVoid())
     return false;
 

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -465,7 +465,8 @@ class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
       } else {
         auto func = cast<FuncDecl>(AFD);
         OptionalTypeKind optionalKind;
-        (void)func->getResultType()->getAnyOptionalObjectType(optionalKind);
+        (void)func->getResultInterfaceType()
+            ->getAnyOptionalObjectType(optionalKind);
         printNullability(optionalKind,
                          NullabilityPrintKind::ContextSensitive);
       }

lib/SILGen/SILGenExpr.cpp

@@ -2342,8 +2342,8 @@ static bool mayLieAboutNonOptionalReturn(SILModule &M,
   // Functions that return non-optional reference type and were imported from
   // Objective-C.
   if (auto func = dyn_cast<FuncDecl>(decl)) {
-    assert((isVerbatimNullableTypeInC(M, func->getResultType())
-            || func->getResultType()->hasArchetype())
+    assert((func->getResultInterfaceType()->hasTypeParameter()
+            || isVerbatimNullableTypeInC(M, func->getResultInterfaceType()))
            && "func's result type is not nullable?!");
     return func->hasClangNode();
   }

lib/SILGen/SILGenFunction.cpp

@@ -465,7 +465,8 @@ SILGenFunction::emitClosureValue(SILLocation loc, SILDeclRef constant,
 void SILGenFunction::emitFunction(FuncDecl *fd) {
   MagicFunctionName = SILGenModule::getMagicFunctionName(fd);
 
-  Type resultTy = fd->getResultType();
+  Type resultTy = ArchetypeBuilder::mapTypeIntoContext(
+      fd, fd->getResultInterfaceType());
   emitProlog(fd, fd->getParameterLists(), resultTy, fd->hasThrows());
   prepareEpilog(resultTy, fd->hasThrows(), CleanupLocation(fd));
 

lib/SILOptimizer/Mandatory/DataflowDiagnostics.cpp

@@ -39,7 +39,7 @@ static void diagnoseMissingReturn(const UnreachableInst *UI,
   Type ResTy;
 
   if (auto *FD = FLoc.getAsASTNode<FuncDecl>()) {
-    ResTy = FD->getResultType();
+    ResTy = FD->getResultInterfaceType();
   } else if (auto *CE = FLoc.getAsASTNode<ClosureExpr>()) {
     ResTy = CE->getResultType();
   } else {

lib/Sema/MiscDiagnostics.cpp

@@ -1297,8 +1297,9 @@ bool swift::fixItOverrideDeclarationTypes(TypeChecker &TC,
     }
     if (auto *method = dyn_cast<FuncDecl>(decl)) {
       auto *baseMethod = cast<FuncDecl>(base);
-      fixedAny |= checkType(method->getBodyResultType(),
-                            baseMethod->getResultType(),
+      auto resultType = ArchetypeBuilder::mapTypeIntoContext(
+          baseMethod, baseMethod->getResultInterfaceType());
+      fixedAny |= checkType(method->getBodyResultType(), resultType,
                             method->getBodyResultTypeLoc().getSourceRange());
     }
     return fixedAny;
@@ -4018,7 +4019,8 @@ Optional<DeclName> TypeChecker::omitNeedlessWords(AbstractFunctionDecl *afd) {
   bool returnsSelf = false;
 
   if (auto func = dyn_cast<FuncDecl>(afd)) {
-    resultType = func->getResultType();
+    resultType = func->getResultInterfaceType();
+    resultType = ArchetypeBuilder::mapTypeIntoContext(func, resultType);
     returnsSelf = func->hasDynamicSelf();
   } else if (isa<ConstructorDecl>(afd)) {
     resultType = contextType;

lib/Sema/TypeCheckType.cpp

@@ -3188,7 +3188,7 @@ bool TypeChecker::isRepresentableInObjC(
   }
 
   if (auto FD = dyn_cast<FuncDecl>(AFD)) {
-    Type ResultType = FD->getResultType();
+    Type ResultType = FD->getResultInterfaceType();
     if (!ResultType->isVoid() &&
         !ResultType->isRepresentableIn(ForeignLanguage::ObjectiveC,
                                        const_cast<FuncDecl *>(FD))) {
@@ -3212,7 +3212,7 @@ bool TypeChecker::isRepresentableInObjC(
 
     const ConstructorDecl *ctor = nullptr;
     if (auto func = dyn_cast<FuncDecl>(AFD)) {
-      resultType = func->getResultType();
+      resultType = func->getResultInterfaceType();
       throwsLoc = func->getThrowsLoc();
     } else {
       ctor = cast<ConstructorDecl>(AFD);

test/api-digester/source-stability.swift.expected

@@ -25,6 +25,14 @@ Var Set.startIndex has declared type change from SetIndex<Element> to Set<Elemen
 Func Dictionary.index(after:) has return type change from DictionaryIndex<Key, Value> to Dictionary<Key, Value>.Index
 Func Dictionary.index(forKey:) has return type change from DictionaryIndex<Key, Value>? to Dictionary<Key, Value>.Index?
 Func Dictionary.remove(at:) has 1st parameter type change from DictionaryIndex<Key, Value> to Dictionary<Key, Value>.Index
+
+/* False positives due to archetype -> interface type change */
+Func OptionSet.insert(_:) has return type change from (inserted: Bool, memberAfterInsert: Self) to (inserted: Bool, memberAfterInsert: Self.Element)
+Func OptionSet.remove(_:) has return type change from Self? to Self.Element?
+Func OptionSet.update(with:) has return type change from Self? to Self.Element?
+Func RandomAccessCollection.distance(from:to:) has return type change from Self.IndexDistance to Self.Index.Stride
+
+/* More DictionaryIndex / SetIndex */
 Func Set.index(after:) has return type change from SetIndex<Element> to Set<Element>.Index
 Func Set.index(of:) has return type change from SetIndex<Element>? to Set<Element>.Index?
 Func Set.remove(at:) has 1st parameter type change from SetIndex<Element> to Set<Element>.Index

tools/swift-api-digester/swift-api-digester.cpp

@@ -1147,7 +1147,7 @@ static SDKNode *constructTypeNode(SDKContext &Ctx, Type T) {
 static SDKNode *constructFunctionNode(SDKContext &Ctx, FuncDecl* FD,
                                       SDKNodeKind Kind, bool SkipFirst) {
   auto Func = SDKNodeInitInfo(Ctx, FD).createSDKNode(Kind);
-  Func->addChild(constructTypeNode(Ctx, FD->getResultType()));
+  Func->addChild(constructTypeNode(Ctx, FD->getResultInterfaceType()));
   for (auto *paramList : FD->getParameterLists()) {
     for (auto param : *paramList)
       Func->addChild(constructTypeNode(Ctx, param->getInterfaceType()));