[DO NOT MERGE] Make Swift 3 / 4 consistent with SE-0054.

include/swift/AST/DiagnosticsSema.def

@@ -3103,12 +3103,6 @@ ERROR(tuple_single_element,none,
 ERROR(tuple_ellipsis,none,
       "cannot create a variadic tuple", ())
 
-WARNING(implicitly_unwrapped_optional_spelling_deprecated,none,
-        "the spelling 'ImplicitlyUnwrappedOptional' is deprecated", ())
-
-WARNING(implicitly_unwrapped_optional_spelling_deprecated_with_fixit,none,
-        "the spelling 'ImplicitlyUnwrappedOptional' is deprecated; use '!' after the type name", ())
-
 ERROR(implicitly_unwrapped_optional_spelling_error,none,
         "the spelling 'ImplicitlyUnwrappedOptional' in unsupported; use an explicit type followed by '!'", ())
 

lib/Sema/TypeCheckType.cpp

@@ -1191,11 +1191,7 @@ resolveTopLevelIdentTypeComponent(TypeChecker &TC, DeclContext *DC,
         assert(genericTyR->getGenericArgs().size() == 1);
         auto *genericArgTyR = genericTyR->getGenericArgs()[0];
 
-        Diagnostic diag = diag::implicitly_unwrapped_optional_spelling_deprecated_with_fixit;
-
-        // For Swift 5 and later, spelling the full name is an error.
-        if (TC.Context.isSwiftVersionAtLeast(5))
-          diag = diag::implicitly_unwrapped_optional_spelling_error_with_fixit;
+        Diagnostic diag = diag::implicitly_unwrapped_optional_spelling_error_with_fixit;
 
         TC.diagnose(comp->getStartLoc(), diag)
           .fixItRemoveChars(
@@ -1206,15 +1202,11 @@ resolveTopLevelIdentTypeComponent(TypeChecker &TC, DeclContext *DC,
               genericTyR->getAngleBrackets().End,
               genericTyR->getAngleBrackets().End.getAdvancedLoc(1));
       } else {
-        Diagnostic diag = diag::implicitly_unwrapped_optional_spelling_deprecated;
-
-        // For Swift 5 and later, spelling the full name is an error.
-        if (TC.Context.isSwiftVersionAtLeast(5))
-          diag = diag::implicitly_unwrapped_optional_spelling_error;
+        Diagnostic diag = diag::implicitly_unwrapped_optional_spelling_error;
 
         TC.diagnose(comp->getStartLoc(), diag);
       }
-    } else if (TC.Context.isSwiftVersionAtLeast(5)) {
+    } else {
       if (isa<GenericIdentTypeRepr>(comp)) {
         auto *genericTyR = cast<GenericIdentTypeRepr>(comp);
         assert(genericTyR->getGenericArgs().size() == 1);
@@ -1231,10 +1223,6 @@ resolveTopLevelIdentTypeComponent(TypeChecker &TC, DeclContext *DC,
       } else {
         TC.diagnose(comp->getStartLoc(), diag::iuo_in_illegal_position);
       }
-    } else {
-      // Pre-Swift-5 warning for spelling ImplicitlyUnwrappedOptional
-      // in places we shouldn't even allow it.
-      TC.diagnose(comp->getStartLoc(), diag::implicitly_unwrapped_optional_spelling_deprecated);
     }
   }
 
@@ -1565,65 +1553,6 @@ Type TypeChecker::resolveIdentifierType(
   return result;
 }
 
-/// Returns true if any illegal IUOs were found. If inference of IUO type is
-/// disabled, IUOs may only be specified in the following positions:
-///  * outermost type
-///  * function param
-///  * function return type
-static bool checkForIllegalIUOs(TypeChecker &TC, TypeRepr *Repr,
-                                TypeResolutionOptions Options) {
-  class IllegalIUOWalker : public ASTWalker {
-    TypeChecker &TC;
-    SmallVector<bool, 4> IUOsAllowed;
-    bool FoundIllegalIUO = false;
-
-  public:
-    IllegalIUOWalker(TypeChecker &TC, bool IsGenericParameter)
-      : TC(TC)
-      , IUOsAllowed{!IsGenericParameter} {}
-
-    bool walkToTypeReprPre(TypeRepr *T) override {
-      bool iuoAllowedHere = IUOsAllowed.back();
-
-      // Raise a diagnostic if we run into a prohibited IUO.
-      if (!iuoAllowedHere) {
-        if (auto *iuoTypeRepr =
-            dyn_cast<ImplicitlyUnwrappedOptionalTypeRepr>(T)) {
-          TC.diagnose(iuoTypeRepr->getStartLoc(), diag::iuo_in_illegal_position)
-            .fixItReplace(iuoTypeRepr->getExclamationLoc(), "?");
-          FoundIllegalIUO = true;
-        }
-      }
-
-      bool childIUOsAllowed = false;
-      if (iuoAllowedHere) {
-        if (auto *tupleTypeRepr = dyn_cast<TupleTypeRepr>(T)) {
-          if (tupleTypeRepr->isParenType()) {
-            childIUOsAllowed = true;
-          }
-        } else if (isa<FunctionTypeRepr>(T)) {
-          childIUOsAllowed = true;
-        } else if (isa<AttributedTypeRepr>(T) || isa<InOutTypeRepr>(T)) {
-          childIUOsAllowed = true;
-        }
-      }
-      IUOsAllowed.push_back(childIUOsAllowed);
-      return true;
-    }
-
-    bool walkToTypeReprPost(TypeRepr *T) override {
-      IUOsAllowed.pop_back();
-      return true;
-    }
-
-    bool getFoundIllegalIUO() const { return FoundIllegalIUO; }
-  };
-
-  IllegalIUOWalker Walker(TC, Options.contains(TR_GenericSignature));
-  Repr->walk(Walker);
-  return Walker.getFoundIllegalIUO();
-}
-
 bool TypeChecker::validateType(TypeLoc &Loc, DeclContext *DC,
                                TypeResolutionOptions options,
                                GenericTypeResolver *resolver,
@@ -1640,13 +1569,6 @@ bool TypeChecker::validateType(TypeLoc &Loc, DeclContext *DC,
     Context.Stats->getFrontendCounters().NumTypesValidated++;
 
   if (Loc.getType().isNull()) {
-    // Swift version < 5? Use the old "illegal IUO" check for
-    // backwards compatibiliy.
-    if (!Context.isSwiftVersionAtLeast(5)) {
-      // Raise error if we parse an IUO type in an illegal position.
-      checkForIllegalIUOs(*this, Loc.getTypeRepr(), options);
-    }
-
     auto type = resolveType(Loc.getTypeRepr(), DC, options, resolver,
                             unsatisfiedDependency);
     if (!type) {
@@ -2815,10 +2737,7 @@ Type TypeResolver::resolveOptionalType(OptionalTypeRepr *repr,
 Type TypeResolver::resolveImplicitlyUnwrappedOptionalType(
        ImplicitlyUnwrappedOptionalTypeRepr *repr,
        TypeResolutionOptions options) {
-
-  // Swift version >= 5? Use the newer check for IUOs appearing in
-  // illegal positions.
-  if (TC.Context.isSwiftVersionAtLeast(5) && !options.contains(TR_AllowIUO)) {
+  if (!options.contains(TR_AllowIUO)) {
     TC.diagnose(repr->getStartLoc(), diag::iuo_in_illegal_position)
       .fixItReplace(repr->getExclamationLoc(), "?");
     return ErrorType::get(Context);
@@ -2851,7 +2770,11 @@ Type TypeResolver::resolveTupleType(TupleTypeRepr *repr,
   auto elementOptions = options;
   if (repr->isParenType()) {
     // We also want to disallow IUO within even a paren.
-    elementOptions -= TR_AllowIUO;
+    // FIXME: Until we remove the IUO type from the type system, we
+    // need to continue to parse IUOs in SIL tests so that we can
+    // match the types we generate from the importer.
+    if (!options.contains(TR_SILMode))
+      elementOptions -= TR_AllowIUO;
 
     // If we have a single ParenType, don't clear the context bits; we
     // still want to parse the type contained therein as if it were in

test/ClangImporter/blocks_parse.swift

@@ -16,7 +16,7 @@ someNSString.enumerateLines({ useString($0) })
 accepts_block(/*not a block=*/()) // expected-error{{cannot convert value of type '()' to expected argument type 'my_block_t' (aka '() -> ()'}}
 
 func testNoEscape(f: @convention(block) () -> Void, nsStr: NSString,
-                  fStr: (String!) -> Void) {
+                  fStr: (String?) -> Void) {
   accepts_noescape_block(f)
   accepts_noescape_block(f)
 

test/ClangImporter/objc_bridging.swift

@@ -26,20 +26,20 @@ extension Set {
 }
 
 func foo() {
-  _  = NSStringToNSString as (String!) -> String?
+  _  = NSStringToNSString as (String?) -> String?
   _ = DummyClass().nsstringProperty.onlyOnString() as String
 
   _  = BOOLtoBOOL as (Bool) -> Bool
   _  = DummyClass().boolProperty.onlyOnBool() as Bool
 
-  _  = arrayToArray as (Array<Any>!) -> (Array<Any>!)
+  _  = arrayToArray as (Array<Any>?) -> (Array<Any>?)
   DummyClass().arrayProperty.onlyOnArray()
 
-  _ = dictToDict as (Dictionary<AnyHashable, Any>!) -> Dictionary<AnyHashable, Any>!
+  _ = dictToDict as (Dictionary<AnyHashable, Any>?) -> Dictionary<AnyHashable, Any>?
 
   DummyClass().dictProperty.onlyOnDictionary()
 
-  _ = setToSet as (Set<AnyHashable>!) -> Set<AnyHashable>!
+  _ = setToSet as (Set<AnyHashable>?) -> Set<AnyHashable>?
   DummyClass().setProperty.onlyOnSet()
 }
 

test/ClangImporter/objc_parse.swift

@@ -378,7 +378,7 @@ func testPreferClassMethodToCurriedInstanceMethod(_ obj: NSObject) {
   // FIXME: We shouldn't need the ": Bool" type annotation here.
   // <rdar://problem/18006008>
   let _: Bool = NSObject.isEqual(obj)
-  _ = NSObject.isEqual(obj) as (NSObject!) -> Bool // no-warning
+  _ = NSObject.isEqual(obj) as (NSObject?) -> Bool // no-warning
 }
 
 

test/Constraints/keyword_arguments.swift

@@ -325,7 +325,7 @@ trailingclosure1(1) { return 5 } // expected-error{{missing argument label 'x:'
 
 trailingclosure1(x: 1, { return 5 }) // expected-error{{missing argument label 'f:' in call}} {{24-24=f: }}
 
-func trailingclosure2(x: Int, f: (() -> Int)!...) {}
+func trailingclosure2(x: Int, f: (() -> Int)...) {}
 trailingclosure2(x: 5) { return 5 }
 
 func trailingclosure3(x: Int, f: (() -> Int)!) {

test/Constraints/protocols.swift

@@ -318,11 +318,11 @@ func testClonableArchetype<T : Clonable>(_ t: T) {
   let _: (Bool) -> T? = id(t.extMaybeClone)
   let _: T? = id(t.extMaybeClone(true))
 
-  let _: (T) -> (Bool) -> T! = id(T.extProbablyClone)
-  let _: (Bool) -> T! = id(T.extProbablyClone(t))
+  let _: (T) -> (Bool) -> T! = id(T.extProbablyClone) // expected-error {{implicitly unwrapped optionals are only allowed at top level and as function results}}
+  let _: (Bool) -> T! = id(T.extProbablyClone(t)) // expected-error {{implicitly unwrapped optionals are only allowed at top level and as function results}}
   let _: T! = id(T.extProbablyClone(t)(true))
 
-  let _: (Bool) -> T! = id(t.extProbablyClone)
+  let _: (Bool) -> T! = id(t.extProbablyClone) // expected-error {{implicitly unwrapped optionals are only allowed at top level and as function results}}
   let _: T! = id(t.extProbablyClone(true))
 
   // Static member of extension returning Self)
@@ -332,7 +332,7 @@ func testClonableArchetype<T : Clonable>(_ t: T) {
   let _: (Bool) -> T? = id(T.returnSelfOptionalStatic)
   let _: T? = id(T.returnSelfOptionalStatic(false))
 
-  let _: (Bool) -> T! = id(T.returnSelfIUOStatic)
+  let _: (Bool) -> T! = id(T.returnSelfIUOStatic) // expected-error {{implicitly unwrapped optionals are only allowed at top level and as function results}}
   let _: T! = id(T.returnSelfIUOStatic(true))
 }
 
@@ -358,7 +358,7 @@ func testClonableExistential(_ v: Clonable, _ vv: Clonable.Type) {
   let _: (Bool) -> Clonable? = id(vv.returnSelfOptionalStatic)
   let _: Clonable? = id(vv.returnSelfOptionalStatic(false))
 
-  let _: (Bool) -> Clonable! = id(vv.returnSelfIUOStatic)
+  let _: (Bool) -> Clonable! = id(vv.returnSelfIUOStatic) // expected-error {{implicitly unwrapped optionals are only allowed at top level and as function results}}
   let _: Clonable! = id(vv.returnSelfIUOStatic(true))
 
   let _ = v.badClonerFn() // expected-error {{member 'badClonerFn' cannot be used on value of protocol type 'Clonable'; use a generic constraint instead}}

test/Interpreter/FunctionConversion.swift

@@ -84,22 +84,20 @@ func a1(s: AddrOnly?) -> AddrOnly {
 
 FunctionConversionTestSuite.test("Optional") {
   let g11: (Trivial) -> Trivial? = t1
-  let g12: (Trivial!) -> Trivial? = t1
+  let g12: (Trivial?) -> Trivial? = t1
 
   expectEqual(22, g11(Trivial(n: 11))?.n)
   expectEqual(24, g12(Trivial(n: 12))?.n)
 
   let g21: (Loadable?) -> Loadable? = l1
-  let g22: (Loadable!) -> Loadable? = l1
+  let g22: (Loadable?) -> Loadable? = l1
 
   expectEqual(42, g21(Loadable(n: 21))?.n)
-  expectEqual(44, g22(Loadable(n: 22))?.n)
 
   let g31: (AddrOnly?) -> AddrOnly? = a1
-  let g32: (AddrOnly!) -> AddrOnly? = a1
+  let g32: (AddrOnly?) -> AddrOnly? = a1
 
   expectEqual(62, g31(AddrOnly(n: 31))?.n)
-  expectEqual(64, g32(AddrOnly(n: 32))?.n)
 }
 
 func t2(s: Quilt) -> Trivial {

test/Migrator/Inputs/Cities.swift

@@ -16,7 +16,7 @@ open class Cities {
 
 public protocol ExtraCities {
   func coolum(x: [String : [Int : [(((String))?)]]])
-  func blibli(x: (String?, String) -> String!)
+  func blibli(x: (String?, String) -> String?)
   func currimundi(x: (Int, (Int, Int))!)
 }
 

test/Migrator/wrap_optional.swift

@@ -31,24 +31,20 @@ extension ExtraCities {
 }
 
 class MyExtraCities : ExtraCities {
-  func blibli(x: (String?, String) -> String!) {}
+  func blibli(x: (String?, String) -> String?) {}
   func currimundi(x: (Int, (Int, Int))!) {}
 }
 
 typealias IntAnd<T> = (Int, T)
-class Outer {
-  typealias Inner = (String?, String) -> String!
-}
 
 class MyExtraCitiesWithAliases : ExtraCities {
-  func blibli(x: Outer.Inner) {}
+  func blibli(x: (String?, String) -> String?) {}
   func currimundi(x: (Int, IntAnd<Int>)!) {}
 }
 
 typealias OptString = String?
-typealias ImplicitlyUnwrapped<T> = T!
 
 class MyExtraCitiesWithMoreAliases : ExtraCities {
-  func blibli(x: (OptString, String) -> String!) {}
-  func currimundi(x: ImplicitlyUnwrapped<(Int, (Int, Int))>) {}
+  func blibli(x: (OptString, String) -> String?) {}
+  func currimundi(x: (Int, (Int, Int))!) {}
 }

test/Migrator/wrap_optional.swift.expected

@@ -31,24 +31,20 @@ extension ExtraCities {
 }
 
 class MyExtraCities : ExtraCities {
-  func blibli(x: ((String, String) -> String?)?) {}
+  func blibli(x: (String?, String) -> String?) {}
   func currimundi(x: (Int, (Int?, Int))?) {}
 }
 
 typealias IntAnd<T> = (Int, T)
-class Outer {
-  typealias Inner = (String?, String) -> String!
-}
 
 class MyExtraCitiesWithAliases : ExtraCities {
-  func blibli(x: Outer.Inner?) {}
+  func blibli(x: (String?, String) -> String?) {}
   func currimundi(x: (Int, IntAnd<Int>)?) {}
 }
 
 typealias OptString = String?
-typealias ImplicitlyUnwrapped<T> = T!
 
 class MyExtraCitiesWithMoreAliases : ExtraCities {
-  func blibli(x: ((OptString, String) -> String?)?) {}
-  func currimundi(x: ImplicitlyUnwrapped<(Int, (Int, Int))>) {}
+  func blibli(x: (OptString, String) -> String?) {}
+  func currimundi(x: (Int, (Int?, Int))?) {}
 }

test/Parse/optional.swift

@@ -14,4 +14,4 @@ var e : (() -> A)?
 var f = e?()
 
 struct B<T> {}
-var g = B<A!>()
+var g = B<A?>()

test/SILGen/function_conversion.swift

@@ -129,7 +129,7 @@ func convOptionalTrivial(_ t1: @escaping (Trivial?) -> Trivial) {
 
 // CHECK:         function_ref @_T019function_conversion7TrivialVSgACIexyd_A2DIexyd_TR
 // CHECK:         partial_apply
-  let _: (Trivial!) -> Trivial? = t1
+  let _: (Trivial?) -> Trivial? = t1
 }
 
 // CHECK-LABEL: sil shared [transparent] [serializable] [reabstraction_thunk] @_T019function_conversion7TrivialVSgACIexyd_AcDIexyd_TR : $@convention(thin) (Trivial, @owned @callee_owned (Optional<Trivial>) -> Trivial) -> Optional<Trivial>
@@ -151,7 +151,7 @@ func convOptionalLoadable(_ l1: @escaping (Loadable?) -> Loadable) {
 
 // CHECK:         function_ref @_T019function_conversion8LoadableVSgACIexxo_A2DIexxo_TR
 // CHECK:         partial_apply
-  let _: (Loadable!) -> Loadable? = l1
+  let _: (Loadable?) -> Loadable? = l1
 }
 
 // CHECK-LABEL: sil shared [transparent] [serializable] [reabstraction_thunk] @_T019function_conversion8LoadableVSgACIexxo_A2DIexxo_TR : $@convention(thin) (@owned Optional<Loadable>, @owned @callee_owned (@owned Optional<Loadable>) -> @owned Loadable) -> @owned Optional<Loadable>
@@ -164,10 +164,6 @@ func convOptionalAddrOnly(_ a1: @escaping (AddrOnly?) -> AddrOnly) {
 // CHECK:         function_ref @_T019function_conversion8AddrOnlyVSgACIexir_A2DIexir_TR
 // CHECK:         partial_apply
   let _: (AddrOnly?) -> AddrOnly? = a1
-
-// CHECK:         function_ref @_T019function_conversion8AddrOnlyVSgACIexir_A2DIexir_TR
-// CHECK:         partial_apply
-  let _: (AddrOnly!) -> AddrOnly? = a1
 }
 
 // CHECK-LABEL: sil shared [transparent] [serializable] [reabstraction_thunk] @_T019function_conversion8AddrOnlyVSgACIexir_A2DIexir_TR : $@convention(thin) (@in Optional<AddrOnly>, @owned @callee_owned (@in Optional<AddrOnly>) -> @out AddrOnly) -> @out Optional<AddrOnly>

test/SILGen/objc_bridging.swift

@@ -514,7 +514,7 @@ func applyStringBlock(_ f: @convention(block) (String) -> String, x: String) ->
 // CHECK: } // end sil function '_T013objc_bridging16applyStringBlockS3SXB_SS1xtF'
 
 // CHECK-LABEL: sil hidden @_T013objc_bridging15bridgeCFunction{{.*}}F
-func bridgeCFunction() -> (String!) -> (String!) {
+func bridgeCFunction() -> (String?) -> (String?) {
   // CHECK: [[THUNK:%.*]] = function_ref @_T0SC18NSStringFromStringSQySSGABFTO : $@convention(thin) (@owned Optional<String>) -> @owned Optional<String>
   // CHECK: [[THICK:%.*]] = thin_to_thick_function [[THUNK]]
   // CHECK: return [[THICK]]