Merge pull request #14214 from rudkx/iuo-attr-on-accessor-argument

IUO: Set the IUO attribute on ParamDecls for accessors arguments.

Author: rudkx

lib/Parse/ParseDecl.cpp

@@ -3547,9 +3547,10 @@ static AccessorDecl *createAccessorFunc(SourceLoc DeclLoc,
   return D;
 }
 
-static ParamDecl *
-createSetterAccessorArgument(SourceLoc nameLoc, Identifier name,
-                             AccessorKind accessorKind, Parser &P) {
+static ParamDecl *createSetterAccessorArgument(SourceLoc nameLoc,
+                                               Identifier name,
+                                               AccessorKind accessorKind,
+                                               Parser &P, TypeLoc elementType) {
   // Add the parameter. If no name was specified, the name defaults to
   // 'value'.
   bool isNameImplicit = name.empty();
@@ -3568,15 +3569,25 @@ createSetterAccessorArgument(SourceLoc nameLoc, Identifier name,
 
   // AST Walker shouldn't go into the type recursively.
   result->setIsTypeLocImplicit(true);
+
+  if (auto *repr = elementType.getTypeRepr()) {
+    if (repr->getKind() ==
+        TypeReprKind::ImplicitlyUnwrappedOptional) {
+      result->getAttrs().add(
+          new (P.Context) ImplicitlyUnwrappedOptionalAttr(/* implicit= */ true));
+    }
+  }
+
   return result;
 }
 
 /// Parse a "(value)" specifier for "set" or "willSet" if present.  Create a
 /// parameter list to represent the spelled argument or return null if none is
 /// present.
-static ParameterList *
-parseOptionalAccessorArgument(SourceLoc SpecifierLoc,
-                              Parser &P, AccessorKind Kind) {
+static ParameterList *parseOptionalAccessorArgument(SourceLoc SpecifierLoc,
+                                                    Parser &P,
+                                                    AccessorKind Kind,
+                                                    TypeLoc ElementTy) {
   // 'set' and 'willSet' have a (value) parameter, 'didSet' takes an (oldValue)
   // parameter and 'get' and always takes a () parameter.
   if (Kind != AccessorKind::IsSetter && Kind != AccessorKind::IsWillSet &&
@@ -3614,7 +3625,7 @@ parseOptionalAccessorArgument(SourceLoc SpecifierLoc,
   }
 
   if (Name.empty()) NameLoc = SpecifierLoc;
-  auto param = createSetterAccessorArgument(NameLoc, Name, Kind, P);
+  auto param = createSetterAccessorArgument(NameLoc, Name, Kind, P, ElementTy);
   return ParameterList::create(P.Context, StartLoc, param, EndLoc);
 }
 
@@ -3846,8 +3857,8 @@ bool Parser::parseGetSetImpl(ParseDeclOptions Flags,
       if (Tok.is(tok::l_paren))
         diagnose(Loc, diag::protocol_setter_name);
 
-      auto *ValueNameParams
-        = parseOptionalAccessorArgument(Loc, *this, Kind);
+      auto *ValueNameParams =
+          parseOptionalAccessorArgument(Loc, *this, Kind, ElementTy);
 
       // Set up a function declaration.
       TheDecl = createAccessorFunc(Loc, ValueNameParams,
@@ -3970,7 +3981,7 @@ bool Parser::parseGetSetImpl(ParseDeclOptions Flags,
     //
     //     set-name    ::= '(' identifier ')'
     auto *ValueNamePattern =
-      parseOptionalAccessorArgument(Loc, *this, Kind);
+        parseOptionalAccessorArgument(Loc, *this, Kind, ElementTy);
 
     SyntaxParsingContext BlockCtx(SyntaxContext, SyntaxKind::CodeBlock);
     if (AccessorKeywordLoc.isInvalid()) {
@@ -4426,8 +4437,8 @@ void Parser::ParsedAccessors::record(Parser &P, AbstractStorageDecl *storage,
     auto argFunc = (WillSet ? WillSet : DidSet);
     auto argLoc = argFunc->getParameterLists().back()->getStartLoc();
 
-    auto argument = createSetterAccessorArgument(argLoc, Identifier(),
-                                                 AccessorKind::IsSetter, P);
+    auto argument = createSetterAccessorArgument(
+        argLoc, Identifier(), AccessorKind::IsSetter, P, elementTy);
     auto argList = ParameterList::create(P.Context, argument);
     Set = createImplicitAccessor(AccessorKind::IsSetter,
                                  AddressorKind::NotAddressor, argList);
@@ -4448,8 +4459,8 @@ void Parser::ParsedAccessors::record(Parser &P, AbstractStorageDecl *storage,
   if (MutableAddressor) {
     assert(Get && !Set);
     auto argument =
-      createSetterAccessorArgument(MutableAddressor->getLoc(), Identifier(),
-                                   AccessorKind::IsSetter, P);
+        createSetterAccessorArgument(MutableAddressor->getLoc(), Identifier(),
+                                     AccessorKind::IsSetter, P, elementTy);
     auto argList = ParameterList::create(P.Context, argument);
     Set = createImplicitAccessor(AccessorKind::IsSetter,
                                  AddressorKind::NotAddressor, argList);

test/Constraints/iuo.swift

@@ -16,13 +16,34 @@ struct S {
   var j: Int!
   let k: Int
   var m: Int
+  var n: Int! {
+    get {
+      return m
+    }
+    set {
+      m = newValue
+    }
+  }
+  var o: Int! {
+    willSet {
+      m = newValue
+    }
+    didSet {
+      m = oldValue
+    }
+  }
 
   func fn() -> Int! { return i }
 
   static func static_fn() -> Int! { return 0 }
 
   subscript(i: Int) -> Int! {
-    return i
+    set {
+      m = newValue
+    }
+    get {
+      return i
+    }
   }
 
   init(i: Int!, j: Int!, k: Int, m: Int) {