Add package access level to enum AccessLevel

Resolves rdar://104198440

Author: elsh

include/swift/AST/AccessScope.h

@@ -70,6 +70,7 @@ class AccessScope {
       return RHS.isPublic();
     if (isPackage())
       return RHS.isPackage();
+
     return getDeclContext() == RHS.getDeclContext();
   }
 
@@ -98,7 +99,6 @@ class AccessScope {
     }
     if (isPackage())
       return AS.isPublic();
-
     // If this is public, it can't be less than access level of AS
     // so return false
     return false;

include/swift/AST/AttrKind.h

@@ -60,6 +60,12 @@ enum class AccessLevel : uint8_t {
   FilePrivate,
   /// Internal access is limited to the current module.
   Internal,
+  /// Package access is not limited, but some capabilities may be
+  /// restricted outside of the current package containing modules.
+  /// It's similar to Public in that it's accessible from other modules
+  /// and subclassable only within the defining module as long as
+  /// the modules are in the same package.
+  Package,
   /// Public access is not limited, but some capabilities may be
   /// restricted outside of the current module.
   Public,

include/swift/AST/Decl.h

@@ -687,13 +687,14 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     NumPathElements : 8
   );
 
-  SWIFT_INLINE_BITFIELD(ExtensionDecl, Decl, 3+1,
+  SWIFT_INLINE_BITFIELD(ExtensionDecl, Decl, 4+1,
     /// An encoding of the default and maximum access level for this extension.
+    /// The value 4 corresponds to AccessLevel::Public
     ///
     /// This is encoded as (1 << (maxAccess-1)) | (1 << (defaultAccess-1)),
     /// which works because the maximum is always greater than or equal to the
     /// default, and 'private' is never used. 0 represents an uncomputed value.
-    DefaultAndMaxAccessLevel : 3,
+    DefaultAndMaxAccessLevel : 4,
 
     /// Whether there is are lazily-loaded conformances for this extension.
     HasLazyConformances : 1

lib/APIDigester/ModuleAnalyzerNodes.cpp

@@ -1733,6 +1733,7 @@ SDKContext::shouldIgnore(Decl *D, const Decl* Parent) const {
     case AccessLevel::Private:
     case AccessLevel::FilePrivate:
       return true;
+    case AccessLevel::Package:
     case AccessLevel::Public:
     case AccessLevel::Open:
       break;

lib/AST/ASTPrinter.cpp

@@ -728,6 +728,9 @@ class PrintAST : public ASTVisitor<PrintAST> {
     case AccessLevel::Public:
       Printer << tok::kw_public;
       break;
+    case AccessLevel::Package:
+      Printer.printKeyword("package", Options);
+      break;
     case AccessLevel::Open:
       Printer.printKeyword("open", Options);
       break;

lib/AST/ASTVerifier.cpp

@@ -944,7 +944,7 @@ class Verifier : public ASTWalker {
         PrettyStackTraceDecl debugStack("verifying access", D);
         if (!D->getASTContext().isAccessControlDisabled() &&
             D->getFormalAccessScope().isPublic() &&
-            D->getFormalAccess() < AccessLevel::Public) {
+            D->getFormalAccess() <= AccessLevel::Package) {
           Out << "non-public decl has no formal access scope\n";
           D->dump(Out);
           abort();

lib/AST/AccessRequests.cpp

@@ -251,6 +251,8 @@ DefaultAndMaxAccessLevelRequest::evaluate(Evaluator &evaluator,
       maxAccess = AccessLevel::Public;
     } else if (maxScope->isPublic()) {
       maxAccess = AccessLevel::Public;
+    } else if (maxScope->isPackage()) {
+      maxAccess = AccessLevel::Package;
     } else if (isa<ModuleDecl>(maxScope->getDeclContext())) {
       maxAccess = AccessLevel::Internal;
     } else {

lib/AST/Attr.cpp

@@ -74,6 +74,7 @@ StringRef swift::getAccessLevelSpelling(AccessLevel value) {
   case AccessLevel::Private: return "private";
   case AccessLevel::FilePrivate: return "fileprivate";
   case AccessLevel::Internal: return "internal";
+  case AccessLevel::Package: return "package";
   case AccessLevel::Public: return "public";
   case AccessLevel::Open: return "open";
   }

lib/AST/Decl.cpp

@@ -3598,6 +3598,7 @@ AccessLevel ValueDecl::getEffectiveAccess() const {
   switch (effectiveAccess) {
   case AccessLevel::Open:
     break;
+  case AccessLevel::Package:
   case AccessLevel::Public:
   case AccessLevel::Internal:
     if (getModuleContext()->isTestingEnabled() ||
@@ -3720,6 +3721,7 @@ getAccessScopeForFormalAccess(const ValueDecl *VD,
                                      : AccessLimitKind::None);
   case AccessLevel::Internal:
     return AccessScope(resultDC->getParentModule());
+  case AccessLevel::Package:
   case AccessLevel::Public:
   case AccessLevel::Open:
     return AccessScope::getPublic();
@@ -3869,6 +3871,7 @@ static bool checkAccess(const DeclContext *useDC, const ValueDecl *VD,
     auto *useSF = dyn_cast<SourceFile>(useFile);
     return useSF && useSF->hasTestableOrPrivateImport(access, sourceModule);
   }
+  case AccessLevel::Package:
   case AccessLevel::Public:
   case AccessLevel::Open:
     return true;

lib/AST/Module.cpp

@@ -2752,6 +2752,7 @@ bool SourceFile::hasTestableOrPrivateImport(
   auto *module = ofDecl->getModuleContext();
   switch (accessLevel) {
   case AccessLevel::Internal:
+  case AccessLevel::Package:
   case AccessLevel::Public:
     // internal/public access only needs an import marked as @_private. The
     // filename does not need to match (and we don't serialize it for such