Merge pull request #19750 from slavapestov/remove-swift-3

Remove some more Swift 3 compatibility hacks

Author: slavapestov

include/swift/AST/AccessScopeChecker.h

@@ -55,19 +55,15 @@ class TypeReprAccessScopeChecker : private ASTWalker, AccessScopeChecker {
 };
 
 class TypeAccessScopeChecker : private TypeWalker, AccessScopeChecker {
-  bool CanonicalizeParentTypes;
-
   TypeAccessScopeChecker(const DeclContext *useDC,
-                         bool treatUsableFromInlineAsPublic,
-                         bool canonicalizeParentTypes);
+                         bool treatUsableFromInlineAsPublic);
 
   Action walkToTypePre(Type T);
 
 public:
   static Optional<AccessScope>
   getAccessScope(Type T, const DeclContext *useDC,
-                 bool treatUsableFromInlineAsPublic = false,
-                 bool canonicalizeParentTypes = false);
+                 bool treatUsableFromInlineAsPublic = false);
 };
 
 }

include/swift/AST/DiagnosticsParse.def

@@ -1480,9 +1480,6 @@ ERROR(where_without_generic_params,none,
       "'where' clause cannot be attached to "
       "%select{a non-generic|a protocol|an associated type}0 "
       "declaration", (unsigned))
-WARNING(swift3_where_inside_brackets,none,
-        "'where' clause next to generic parameters is deprecated "
-        "and will be removed in the future version of Swift", ())
 ERROR(where_inside_brackets,none,
         "'where' clause next to generic parameters is obsolete, "
         "must be written following the declaration's type", ())

include/swift/AST/DiagnosticsSema.def

@@ -1370,10 +1370,6 @@ ERROR(nscoding_unstable_mangled_name,none,
       "%select{private|fileprivate|nested|local}0 class %1 has an "
       "unstable name when archiving via 'NSCoding'",
       (unsigned, Type))
-WARNING(nscoding_unstable_mangled_name_warn,none,
-        "%select{private|fileprivate|nested|local}0 class %1 has an "
-        "unstable name when archiving via 'NSCoding'",
-        (unsigned, Type))
 NOTE(unstable_mangled_name_add_objc_new,none,
      "for new classes, use '@objc' to specify a unique, prefixed Objective-C "
      "runtime name", ())
@@ -1626,10 +1622,6 @@ ERROR(requirement_restricts_self,none,
       "%0 requirement %1 cannot add constraint '%2%select{:|:| ==|:}3 %4' on "
       "'Self'",
       (DescriptiveDeclKind, DeclName, StringRef, unsigned, StringRef))
-WARNING(requirement_restricts_self_swift3,none,
-        "adding constraint '%2%select{:|:| ==|:}3 %4' on 'Self' via %0 "
-        "requirement %1 is deprecated in Swift 3",
-        (DescriptiveDeclKind, DeclName, StringRef, unsigned, StringRef))
 ERROR(witness_argument_name_mismatch,none,
       "%select{method|initializer}0 %1 has different argument labels from those "
       "required by protocol %2 (%3)", (bool, DeclName, Type, DeclName))
@@ -2150,9 +2142,6 @@ ERROR(override_dynamic_self_mismatch,none,
 ERROR(override_class_declaration_in_extension,none,
       "cannot override a non-dynamic class declaration from an extension",
       ())
-WARNING(override_class_declaration_in_extension_warning,none,
-      "cannot override a non-dynamic class declaration from an extension",
-      ())
 ERROR(override_throws,none,
       "cannot override non-throwing %select{method|initializer}0 with "
       "throwing %select{method|initializer}0", (bool))
@@ -2250,8 +2239,6 @@ ERROR(inheritance_from_cf_class,none,
 ERROR(inheritance_from_objc_runtime_visible_class,none,
       "cannot inherit from class %0 because it is only visible via the "
       "Objective-C runtime", (Identifier))
-WARNING(class_inherits_anyobject,none,
-        "conformance of class %0 to 'AnyObject' is redundant", (Type))
 
 // Enums
 ERROR(enum_case_access,none,
@@ -2343,9 +2330,6 @@ NOTE(construct_raw_representable_from_unwrapped_value,none,
      "construct %0 from unwrapped %1 value", (Type, Type))
 
 // Derived conformances
-ERROR(swift3_cannot_synthesize_in_extension,none,
-      "implementation of %0 cannot be automatically synthesized in an extension "
-      "in Swift 3", (Type))
 ERROR(cannot_synthesize_init_in_extension_of_nonfinal,none,
       "implementation of %0 for non-final class cannot be automatically "
       "synthesized in extension because initializer requirement %1 can only be "
@@ -2490,9 +2474,6 @@ ERROR(override_static,none,
 ERROR(member_cannot_be_final,none,
       "only classes and class members may be marked with 'final'",
       ())
-WARNING(protocol_extension_cannot_be_final,none,
-      "functions in a protocol extension do not need to be marked with 'final'",
-      ())
 
 ERROR(final_not_allowed_here,none,
       "'final' may only be applied to classes, properties, methods, and "
@@ -3303,10 +3284,6 @@ ERROR(isa_collection_downcast_pattern_value_unimplemented,none,
       "collection downcast in cast pattern is not implemented; use an explicit "
       "downcast to %0 instead", (Type))
 
-WARNING(swift3_ignore_specialized_enum_element_call,none,
-        "cannot specialize enum case; ignoring generic argument, "
-        "which will be rejected in future version of Swift", ())
-
 //------------------------------------------------------------------------------
 // MARK: Error-handling diagnostics
 //------------------------------------------------------------------------------
@@ -3809,11 +3786,6 @@ ERROR(objc_class_method_not_permitted,none,
       OBJC_DIAG_SELECT " defines Objective-C class method %2, which is "
       "not permitted by Swift", (unsigned, DeclName, ObjCSelector))
 
-WARNING(objc_class_method_not_permitted_swift3_compat_warning,none,
-      OBJC_DIAG_SELECT " defines Objective-C class method %2, which is "
-      "not guaranteed to be invoked by Swift and will be disallowed in future "
-      "versions", (unsigned, DeclName, ObjCSelector))
-
 ERROR(objc_witness_selector_mismatch,none,
       "Objective-C method %2 provided by " OBJC_DIAG_SELECT
       " does not match the requirement's selector (%3)",

lib/AST/AccessScopeChecker.cpp

@@ -63,21 +63,14 @@ TypeReprAccessScopeChecker::getAccessScope(TypeRepr *TR, const DeclContext *useD
 }
 
 TypeAccessScopeChecker::TypeAccessScopeChecker(const DeclContext *useDC,
-                                               bool treatUsableFromInlineAsPublic,
-                                               bool canonicalizeParentTypes)
-  : AccessScopeChecker(useDC, treatUsableFromInlineAsPublic),
-    CanonicalizeParentTypes(canonicalizeParentTypes) {}
+                                               bool treatUsableFromInlineAsPublic)
+  : AccessScopeChecker(useDC, treatUsableFromInlineAsPublic) {}
 
 TypeWalker::Action
 TypeAccessScopeChecker::walkToTypePre(Type T) {
   ValueDecl *VD;
-  if (auto *BNAD = dyn_cast<NameAliasType>(T.getPointer())) {
-    if (CanonicalizeParentTypes &&
-        BNAD->getDecl()->getUnderlyingTypeLoc().getType()->hasTypeParameter())
-      VD = nullptr;
-    else
-      VD = BNAD->getDecl();
-  }
+  if (auto *BNAD = dyn_cast<NameAliasType>(T.getPointer()))
+    VD = BNAD->getDecl();
   else if (auto *NTD = T->getAnyNominal())
     VD = NTD;
   else
@@ -86,39 +79,13 @@ TypeAccessScopeChecker::walkToTypePre(Type T) {
   if (!visitDecl(VD))
     return Action::Stop;
 
-  if (!CanonicalizeParentTypes) {
-    return Action::Continue;
-  }
-
-  Type nominalParentTy;
-  if (auto nominalTy = dyn_cast<NominalType>(T.getPointer())) {
-    nominalParentTy = nominalTy->getParent();
-  } else if (auto genericTy = dyn_cast<BoundGenericType>(T.getPointer())) {
-    nominalParentTy = genericTy->getParent();
-    for (auto genericArg : genericTy->getGenericArgs())
-      genericArg.walk(*this);
-  } else if (auto NameAliasTy =
-             dyn_cast<NameAliasType>(T.getPointer())) {
-    // The parent type would have been lost previously, so look right through
-    // this type.
-    if (NameAliasTy->getDecl()->getUnderlyingTypeLoc().getType()
-        ->hasTypeParameter())
-      Type(NameAliasTy->getSinglyDesugaredType()).walk(*this);
-  } else {
-    return Action::Continue;
-  }
-
-  if (nominalParentTy)
-    nominalParentTy->getCanonicalType().walk(*this);
-  return Action::SkipChildren;
+  return Action::Continue;
 }
 
 Optional<AccessScope>
 TypeAccessScopeChecker::getAccessScope(Type T, const DeclContext *useDC,
-                                       bool treatUsableFromInlineAsPublic,
-                                       bool canonicalizeParentTypes) {
-  TypeAccessScopeChecker checker(useDC, treatUsableFromInlineAsPublic,
-                                 canonicalizeParentTypes);
+                                       bool treatUsableFromInlineAsPublic) {
+  TypeAccessScopeChecker checker(useDC, treatUsableFromInlineAsPublic);
   T.walk(checker);
   return checker.Scope;
 }

lib/AST/DeclContext.cpp

@@ -780,9 +780,6 @@ IterableDeclContext::castDeclToIterableDeclContext(const Decl *D) {
 /// declaration or extension, the supplied context is returned.
 static const DeclContext *
 getPrivateDeclContext(const DeclContext *DC, const SourceFile *useSF) {
-  if (DC->getASTContext().isSwiftVersion3())
-    return DC;
-
   auto NTD = DC->getSelfNominalTypeDecl();
   if (!NTD)
     return DC;
@@ -834,10 +831,6 @@ bool AccessScope::allowsPrivateAccess(const DeclContext *useDC, const DeclContex
   if (useDC->isChildContextOf(sourceDC))
     return true;
 
-  // Only check lexical scope in Swift 3 mode
-  if (useDC->getASTContext().isSwiftVersion3())
-    return false;
-
   // Do not allow access if the sourceDC is in a different file
   auto useSF = useDC->getParentSourceFile();
   if (useSF != sourceDC->getParentSourceFile())

lib/Parse/ParseGeneric.cpp

@@ -225,12 +225,8 @@ Parser::diagnoseWhereClauseInGenericParamList(const GenericParamList *
   if (Tok.is(tok::kw_where))
     WhereClauseText << ',';
 
-  // For Swift 3, keep this warning. 
-  const auto Message = Context.isSwiftVersion3() 
-                             ? diag::swift3_where_inside_brackets 
-                             : diag::where_inside_brackets;
-
-  auto Diag = diagnose(WhereRangeInsideBrackets.Start, Message);
+  auto Diag = diagnose(WhereRangeInsideBrackets.Start,
+                       diag::where_inside_brackets);
 
   Diag.fixItRemoveChars(RemoveWhereRange.getStart(),
                         RemoveWhereRange.getEnd());

lib/Sema/DerivedConformances.cpp

@@ -360,19 +360,6 @@ bool DerivedConformance::checkAndDiagnoseDisallowedContext(
     allowCrossfileExtensions = ED && ED->hasOnlyCasesWithoutAssociatedValues();
   }
 
-  if (TC.Context.isSwiftVersion3()) {
-    // In Swift 3, a 'private' property can't be accessed in any extensions, so
-    // we can't synthesize anything that uses them. Thus, we stick to the old
-    // rule for synthesis, which is never in an extension except for the
-    // Equatable/Hashable cases mentioned above.
-    if (!allowCrossfileExtensions && Nominal != ConformanceDecl) {
-      TC.diagnose(ConformanceDecl->getLoc(),
-                  diag::swift3_cannot_synthesize_in_extension,
-                  getProtocolType());
-      return true;
-    }
-  }
-
   if (!allowCrossfileExtensions &&
       Nominal->getModuleScopeContext() !=
           getConformanceContext()->getModuleScopeContext()) {

lib/Sema/TypeCheckAccess.cpp

@@ -182,53 +182,14 @@ void AccessControlCheckerBase::checkTypeAccessImpl(
   if (!typeAccessScope.hasValue())
     return;
 
-  auto shouldComplainAboutAccessScope =
-      [contextAccessScope](AccessScope scope) -> bool {
-    if (scope.isPublic())
-      return false;
-    if (scope.hasEqualDeclContextWith(contextAccessScope))
-      return false;
-    if (contextAccessScope.isChildOf(scope))
-      return false;
-    return true;
-  };
-
-  if (!shouldComplainAboutAccessScope(typeAccessScope.getValue()))
+  if (typeAccessScope->isPublic())
+    return;
+  if (typeAccessScope->hasEqualDeclContextWith(contextAccessScope))
+    return;
+  if (contextAccessScope.isChildOf(*typeAccessScope))
     return;
 
   auto downgradeToWarning = DowngradeToWarning::No;
-  if (!checkUsableFromInline) {
-    // Swift 3.0 wasn't nearly as strict as checking types because it didn't
-    // look at the TypeRepr at all except to highlight a particular part of the
-    // type in diagnostics, and looked through typealiases in other cases.
-    // Approximate this behavior by running our non-TypeRepr-based check again
-    // and downgrading to a warning when the checks disagree.
-    if (TC.getLangOpts().isSwiftVersion3()) {
-      auto typeOnlyAccessScope =
-        TypeAccessScopeChecker::getAccessScope(
-            type, useDC,
-            /*treatUsableFromInlineAsPublic*/false,
-            /*canonicalizeParents*/true);
-      if (typeOnlyAccessScope.hasValue()) {
-        // If Swift 4 would have complained about a private type, but Swift 4
-        // would only diagnose an internal type, complain about the Swift 3
-        // offense first to avoid confusing users.
-        if (shouldComplainAboutAccessScope(typeOnlyAccessScope.getValue()))
-          typeAccessScope = typeOnlyAccessScope;
-        else
-          downgradeToWarning = DowngradeToWarning::Yes;
-      }
-    }
-
-    // Swift 3.0.0 mistakenly didn't diagnose any issues when the context
-    // access scope represented a private or fileprivate level.
-    if (!contextAccessScope.isPublic() &&
-        !isa<ModuleDecl>(contextAccessScope.getDeclContext()) &&
-        TC.getLangOpts().isSwiftVersion3()) {
-      downgradeToWarning = DowngradeToWarning::Yes;
-    }
-  }
-
   const TypeRepr *complainRepr =
         TypeAccessScopeDiagnoser::findTypeWithScope(
             typeRepr,

lib/Sema/TypeCheckAttr.cpp

@@ -213,14 +213,8 @@ class AttributeEarlyChecker : public AttributeVisitor<AttributeEarlyChecker> {
     // 'final' only makes sense in the context of a class declaration.
     // Reject it on global functions, protocols, structs, enums, etc.
     if (!D->getDeclContext()->getSelfClassDecl()) {
-      if (TC.Context.isSwiftVersion3() && 
-          D->getDeclContext()->getExtendedProtocolDecl())
-        TC.diagnose(attr->getLocation(), 
-          diag::protocol_extension_cannot_be_final)
-          .fixItRemove(attr->getRange());
-      else
-        TC.diagnose(attr->getLocation(), diag::member_cannot_be_final)
-          .fixItRemove(attr->getRange());
+      TC.diagnose(attr->getLocation(), diag::member_cannot_be_final)
+        .fixItRemove(attr->getRange());
 
       // Remove the attribute so child declarations are not flagged as final
       // and duplicate the error message.

lib/Sema/TypeCheckDecl.cpp

@@ -383,18 +383,6 @@ static void checkInheritanceClause(
         if (!inheritedTy)
           continue;
       }
-
-      // Swift 3 compatibility -- a class inheriting from AnyObject is a no-op.
-      if (ctx.LangOpts.isSwiftVersion3() && isa<ClassDecl>(decl) &&
-          inheritedTy->isAnyObject()) {
-        auto classDecl = cast<ClassDecl>(decl);
-        auto removeRange = getRemovalRange(i);
-        diags.diagnose(inherited.getSourceRange().Start,
-                       diag::class_inherits_anyobject,
-                       classDecl->getDeclaredInterfaceType())
-          .fixItRemoveChars(removeRange.Start, removeRange.End);
-        continue;
-      }
     }
 
     // If this is an enum inheritance clause, check for a raw type.

lib/Sema/TypeCheckDeclObjC.cpp

@@ -1584,13 +1584,8 @@ void markAsObjC(ValueDecl *D, ObjCReason reason,
           // Swift 3 and earlier allowed you to override `initialize`, but
           // Swift's semantics do not guarantee that it will be called at
           // the point you expect. It is disallowed in Swift 4 and later.
-          if (sel.getSelectorPieces().front() == ctx.Id_initialize) {
-            if (ctx.LangOpts.isSwiftVersion3())
-              return
-                diag::objc_class_method_not_permitted_swift3_compat_warning;
-            else
-              return diag::objc_class_method_not_permitted;
-          }
+          if (sel.getSelectorPieces().front() == ctx.Id_initialize)
+            return diag::objc_class_method_not_permitted;
           return None;
         case 1:
           if (sel.getSelectorPieces().front() == ctx.Id_allocWithZone)

lib/Sema/TypeCheckDeclOverride.cpp

@@ -1560,9 +1560,7 @@ static bool checkSingleOverride(ValueDecl *override, ValueDecl *base) {
         !base->isDynamic() &&
         override->getDeclContext()->isExtensionContext()) {
       // For compatibility, only generate a warning in Swift 3
-      diags.diagnose(override, (ctx.isSwiftVersion3()
-        ? diag::override_class_declaration_in_extension_warning
-        : diag::override_class_declaration_in_extension));
+      diags.diagnose(override, diag::override_class_declaration_in_extension);
       diags.diagnose(base, diag::overridden_here);
     }
   }

lib/Sema/TypeCheckGeneric.cpp

@@ -263,9 +263,7 @@ void TypeChecker::checkProtocolSelfRequirements(ValueDecl *decl) {
         continue;
 
       diagnose(decl,
-               Context.isSwiftVersion3()
-                 ? diag::requirement_restricts_self_swift3
-                 : diag::requirement_restricts_self,
+               diag::requirement_restricts_self,
                decl->getDescriptiveKind(), decl->getFullName(),
                req.getFirstType().getString(),
                static_cast<unsigned>(req.getKind()),