AST: Remove Swift 3 access control checking

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);
 };
 
 }

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/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,