[NFC] Create PackageUnit class, and Package entries to DeclContext / ASTHierarchy

include/swift/AST/ASTContext.h

@@ -103,6 +103,7 @@ namespace swift {
   class Identifier;
   class InheritedNameSet;
   class ModuleDecl;
+  class PackageUnit;
   class ModuleDependenciesCache;
   class ModuleLoader;
   class NominalTypeDecl;

include/swift/AST/ASTWalker.h

@@ -26,6 +26,7 @@ class Expr;
 class ClosureExpr;
 class CustomAttr;
 class ModuleDecl;
+class PackageUnit;
 class Stmt;
 class Pattern;
 class TypeRepr;
@@ -101,14 +102,15 @@ enum class MacroWalking {
 class ASTWalker {
 public:
   enum class ParentKind {
-    Module, Decl, Stmt, Expr, Pattern, TypeRepr
+    Package, Module, Decl, Stmt, Expr, Pattern, TypeRepr
   };
 
   class ParentTy {
     ParentKind Kind;
     void *Ptr = nullptr;
 
   public:
+    ParentTy(PackageUnit *Pkg) : Kind(ParentKind::Package), Ptr(Pkg) {}
     ParentTy(ModuleDecl *Mod) : Kind(ParentKind::Module), Ptr(Mod) {}
     ParentTy(Decl *D) : Kind(ParentKind::Decl), Ptr(D) {}
     ParentTy(Stmt *S) : Kind(ParentKind::Stmt), Ptr(S) {}
@@ -123,6 +125,10 @@ class ASTWalker {
       return Kind;
     }
 
+    PackageUnit *getAsPackage() const {
+      return Kind == ParentKind::Package ? static_cast<PackageUnit*>(Ptr)
+                                        : nullptr;
+    }
     ModuleDecl *getAsModule() const {
       return Kind == ParentKind::Module ? static_cast<ModuleDecl*>(Ptr)
                                         : nullptr;

include/swift/AST/Decl.h

@@ -4009,7 +4009,7 @@ class NominalTypeDecl : public GenericTypeDecl, public IterableDeclContext {
   bool isGlobalActor() const {
     return getGlobalActorInstance() != nullptr;
   }
-  
+
   /// Return the `DestructorDecl` for a struct or enum's `deinit` declaration.
   /// Returns null if the type is a class, or does not have a declared `deinit`.
   DestructorDecl *getValueTypeDestructor();

include/swift/AST/DeclContext.h

@@ -66,6 +66,7 @@ namespace swift {
   class SourceFile;
   class Type;
   class ModuleDecl;
+  class PackageUnit;
   class GenericTypeDecl;
   class NominalTypeDecl;
   class PrecedenceGroupLookupResult;
@@ -96,7 +97,7 @@ enum class DeclContextKind : unsigned {
   SerializedLocal,
   MacroDecl,
   Last_LocalDeclContextKind = MacroDecl,
-
+  Package,
   Module,
   FileUnit,
   GenericTypeDecl,
@@ -234,6 +235,7 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
     Decl,
     Expr,
     FileUnit,
+    Package,
     Initializer,
     SerializedLocal,
     // If you add a new AST hierarchies, then update the static_assert() below.
@@ -271,6 +273,8 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
       return ASTHierarchy::SerializedLocal;
     case DeclContextKind::FileUnit:
       return ASTHierarchy::FileUnit;
+    case DeclContextKind::Package:
+      return ASTHierarchy::Package;
     case DeclContextKind::Module:
     case DeclContextKind::TopLevelCodeDecl:
     case DeclContextKind::AbstractFunctionDecl:
@@ -296,7 +300,8 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
 
   DeclContext(DeclContextKind Kind, DeclContext *Parent)
       : ParentAndKind(Parent, getASTHierarchyFromKind(Kind)) {
-    if (Kind != DeclContextKind::Module)
+    // if Module kind, it may (or may not) have Package as its parent
+    if (Kind != DeclContextKind::Package && Kind != DeclContextKind::Module)
       assert(Parent != nullptr && "DeclContext must have a parent context");
   }
 
@@ -319,6 +324,14 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
     return getContextKind() <= DeclContextKind::Last_LocalDeclContextKind;
   }
 
+  /// \returns true if this is a context with package-wide scope, e.g. a package,
+  /// a module, or a source file.
+  LLVM_READONLY
+  bool isPackageScopeContext() const; // see swift/AST/Module.h
+
+  LLVM_READONLY
+  bool isPackageContext() const; // see swift/AST/Module.h
+
   /// isModuleContext - Return true if this is a subclass of Module.
   LLVM_READONLY
   bool isModuleContext() const; // see swift/AST/Module.h
@@ -499,6 +512,10 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
     return false;
   }
 
+  /// Returns the package context of the parent module.
+  LLVM_READONLY
+  PackageUnit *getParentModulePackage() const;
+
   /// Returns the module context that contains this context.
   LLVM_READONLY
   ModuleDecl *getParentModule() const;

include/swift/AST/Module.h

@@ -159,6 +159,35 @@ class OverlayFile;
 /// location.
 class ModuleSourceFileLocationMap;
 
+/// Package unit used to allow grouping of modules by a package name.
+/// ModuleDecl can set PackageUnit as a parent in its DeclContext
+/// See \c ModuleDecl
+class PackageUnit: public DeclContext {
+
+  Identifier PackageName;
+
+  PackageUnit(Identifier name);
+
+public:
+  static PackageUnit *
+  create(Identifier name, ASTContext &ctx) {
+    return new (ctx) PackageUnit(name);
+  }
+
+  static bool classof(const DeclContext *DC) {
+    return DC->getContextKind() == DeclContextKind::Package;
+  }
+
+  static bool classof(const PackageUnit *PU) {
+    // FIXME: add a correct check
+    return true;
+  }
+
+  Identifier getName() const {
+    return PackageName;
+  }
+};
+
 /// The minimum unit of compilation.
 ///
 /// A module is made up of several file-units, which are all part of the same
@@ -284,7 +313,7 @@ class ModuleDecl
   /// Used by the debugger to bypass resilient access to fields.
   bool BypassResilience = false;
 
-  ModuleDecl(Identifier name, ASTContext &ctx, ImplicitImportInfo importInfo);
+  ModuleDecl(Identifier name, ASTContext &ctx, ImplicitImportInfo importInfo, PackageUnit *pkg);
 
 public:
   /// Creates a new module with a given \p name.
@@ -293,13 +322,14 @@ class ModuleDecl
   /// imported by each file of this module.
   static ModuleDecl *
   create(Identifier name, ASTContext &ctx,
-         ImplicitImportInfo importInfo = ImplicitImportInfo()) {
-    return new (ctx) ModuleDecl(name, ctx, importInfo);
+         ImplicitImportInfo importInfo = ImplicitImportInfo(),
+         PackageUnit *pkg = nullptr) {
+    return new (ctx) ModuleDecl(name, ctx, importInfo, pkg);
   }
 
   static ModuleDecl *
-  createMainModule(ASTContext &ctx, Identifier name, ImplicitImportInfo iinfo) {
-    auto *Mod = ModuleDecl::create(name, ctx, iinfo);
+  createMainModule(ASTContext &ctx, Identifier name, ImplicitImportInfo iinfo, PackageUnit *pkg = nullptr) {
+    auto *Mod = ModuleDecl::create(name, ctx, iinfo, pkg);
     Mod->Bits.ModuleDecl.IsMainModule = true;
     return Mod;
   }
@@ -416,6 +446,10 @@ class ModuleDecl
   /// Set the name of the package this module belongs to
   void setPackageName(Identifier name) {
     PackageName = name;
+    // TODO: uncomment when PackageUnit gets passed to constructor
+//    PackageUnit *pkgUnit = PackageUnit::create(name, getASTContext());
+//    DeclContext newContext = DeclContext(DeclContextKind::Module, pkgUnit);
+//    setDeclContext(&newContext);
   }
 
   Identifier getExportAsName() const { return ExportAsName; }
@@ -1036,6 +1070,10 @@ inline bool DeclContext::isModuleScopeContext() const {
   return isModuleContext();
 }
 
+inline bool DeclContext::isPackageScopeContext() const {
+  return ParentAndKind.getInt() == ASTHierarchy::Package;
+}
+
 /// Extract the source location from the given module declaration.
 inline SourceLoc extractNearestSourceLoc(const ModuleDecl *mod) {
   return extractNearestSourceLoc(static_cast<const Decl *>(mod));

lib/AST/ASTDumper.cpp

@@ -1359,6 +1359,10 @@ void swift::printContext(raw_ostream &os, DeclContext *dc) {
   }
 
   switch (dc->getContextKind()) {
+  case DeclContextKind::Package:
+    printName(os, cast<PackageUnit>(dc)->getName());
+    break;
+
   case DeclContextKind::Module:
     printName(os, cast<ModuleDecl>(dc)->getRealName());
     break;

lib/AST/ASTMangler.cpp

@@ -2275,6 +2275,8 @@ static Optional<VarDecl*> findFirstVariable(PatternBindingDecl *binding) {
 
 void ASTMangler::appendContext(const DeclContext *ctx, StringRef useModuleName) {
   switch (ctx->getContextKind()) {
+  case DeclContextKind::Package:
+    return;
   case DeclContextKind::Module:
     return appendModule(cast<ModuleDecl>(ctx), useModuleName);
 

lib/AST/AccessRequests.cpp

@@ -115,6 +115,8 @@ AccessLevelRequest::evaluate(Evaluator &evaluator, ValueDecl *D) const {
   case DeclContextKind::SubscriptDecl:
   case DeclContextKind::EnumElementDecl:
     return AccessLevel::Private;
+  case DeclContextKind::Package:
+    return AccessLevel::Package;
   case DeclContextKind::Module:
   case DeclContextKind::FileUnit:
     return AccessLevel::Internal;

lib/AST/DeclContext.cpp

@@ -274,6 +274,14 @@ DeclContext *DeclContext::getParentForLookup() const {
   return getParent();
 }
 
+PackageUnit *DeclContext::getParentModulePackage() const {
+  auto parentModule = getParentModule();
+  auto pkg = parentModule->getParent();
+  if (pkg)
+    return const_cast<PackageUnit *>(cast<PackageUnit>(pkg));
+  return nullptr;
+}
+
 ModuleDecl *DeclContext::getParentModule() const {
   const DeclContext *DC = this;
   while (!DC->isModuleContext())
@@ -306,6 +314,7 @@ SourceFile *DeclContext::getParentSourceFile() const {
       case DeclContextKind::Initializer:
       case DeclContextKind::FileUnit:
       case DeclContextKind::Module:
+      case DeclContextKind::Package:
       case DeclContextKind::SerializedLocal:
         break;
       }
@@ -559,6 +568,8 @@ bool DeclContext::canBeParentOfExtension() const {
 
 bool DeclContext::walkContext(ASTWalker &Walker) {
   switch (getContextKind()) {
+  case DeclContextKind::Package:
+    return false;
   case DeclContextKind::Module:
     return cast<ModuleDecl>(this)->walk(Walker);
   case DeclContextKind::FileUnit:
@@ -652,6 +663,7 @@ unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
 
   const char *Kind;
   switch (getContextKind()) {
+  case DeclContextKind::Package:          Kind = "Package"; break;
   case DeclContextKind::Module:           Kind = "Module"; break;
   case DeclContextKind::FileUnit:         Kind = "FileUnit"; break;
   case DeclContextKind::SerializedLocal:  Kind = "Serialized Local"; break;
@@ -678,6 +690,9 @@ unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
   OS.indent(Depth*2 + indent) << (void*)this << " " << Kind;
 
   switch (getContextKind()) {
+  case DeclContextKind::Package:
+    OS << " name=" << cast<PackageUnit>(this)->getName();
+    break;
   case DeclContextKind::Module:
     OS << " name=" << cast<ModuleDecl>(this)->getName();
     break;
@@ -1206,7 +1221,7 @@ AccessScope::AccessScope(const DeclContext *DC, AccessLimitKind limitKind)
     Value.setPointer(DC);
     isPrivate = true;
   }
-  if (!DC || isa<ModuleDecl>(DC))
+  if (!DC || isa<ModuleDecl>(DC) || isa<PackageUnit>(DC))
     assert(!isPrivate && "public, package, or internal scope can't be private");
 }
 
@@ -1285,6 +1300,8 @@ DeclContextKind DeclContext::getContextKind() const {
     return DeclContextKind::SerializedLocal;
   case ASTHierarchy::FileUnit:
     return DeclContextKind::FileUnit;
+  case ASTHierarchy::Package:
+    return DeclContextKind::Package;
   case ASTHierarchy::Decl: {
     auto decl = reinterpret_cast<const Decl*>(this + 1);
     if (isa<AbstractFunctionDecl>(decl))
@@ -1334,6 +1351,7 @@ bool DeclContext::isAsyncContext() const {
   case DeclContextKind::EnumElementDecl:
   case DeclContextKind::ExtensionDecl:
   case DeclContextKind::SerializedLocal:
+  case DeclContextKind::Package:
   case DeclContextKind::Module:
   case DeclContextKind::GenericTypeDecl:
   case DeclContextKind::MacroDecl:
@@ -1361,6 +1379,7 @@ bool DeclContext::isAsyncContext() const {
 
 SourceLoc swift::extractNearestSourceLoc(const DeclContext *dc) {
   switch (dc->getContextKind()) {
+  case DeclContextKind::Package:
   case DeclContextKind::Module:
     return SourceLoc();
   case DeclContextKind::AbstractFunctionDecl:

lib/AST/DiagnosticEngine.cpp

@@ -1163,6 +1163,9 @@ DiagnosticEngine::diagnosticInfoForDiagnostic(const Diagnostic &diagnostic) {
 
           while (!dc->isModuleContext()) {
             switch (dc->getContextKind()) {
+            case DeclContextKind::Package:
+              llvm_unreachable("Not in a package context!");
+              break;
             case DeclContextKind::Module:
               llvm_unreachable("Not in a module context!");
               break;

lib/AST/Module.cpp

@@ -463,13 +463,19 @@ void SourceLookupCache::invalidate() {
   (void)SameSizeSmallVector{std::move(AllVisibleValues)};
 }
 
+PackageUnit::PackageUnit(Identifier name)
+  : DeclContext(DeclContextKind::Package, nullptr) {
+    PackageName = name;
+}
+
 //===----------------------------------------------------------------------===//
 // Module Implementation
 //===----------------------------------------------------------------------===//
 
 ModuleDecl::ModuleDecl(Identifier name, ASTContext &ctx,
-                       ImplicitImportInfo importInfo)
-    : DeclContext(DeclContextKind::Module, nullptr),
+                       ImplicitImportInfo importInfo,
+                       PackageUnit *pkg = nullptr)
+    : DeclContext(DeclContextKind::Module, pkg),
       TypeDecl(DeclKind::Module, &ctx, name, SourceLoc(), {}),
       ImportInfo(importInfo) {
 

lib/IRGen/GenDecl.cpp

@@ -893,6 +893,8 @@ IRGenModule::getAddrOfContextDescriptorForParent(DeclContext *parent,
             ConstantReference::Direct};
   }
 
+  case DeclContextKind::Package:
+    assert(false && "package decl context kind should not have been reached");
   case DeclContextKind::FileUnit:
   case DeclContextKind::MacroDecl:
     parent = parent->getParentModule();

lib/IRGen/IRGenDebugInfo.cpp

@@ -612,6 +612,10 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
     case DeclContextKind::TopLevelCodeDecl:
       return getOrCreateContext(DC->getParent());
 
+    case DeclContextKind::Package: {
+      auto *pkg = cast<PackageUnit>(DC);
+      return getOrCreateContext(pkg);
+    }
     case DeclContextKind::Module:
       return getOrCreateModule(
           {ImportPath::Access(), cast<ModuleDecl>(DC)});

lib/Refactoring/Refactoring.cpp

@@ -888,6 +888,7 @@ static void analyzeRenameScope(ValueDecl *VD, Optional<RenameRefInfo> RefInfo,
   case DeclContextKind::AbstractClosureExpr:
   case DeclContextKind::Initializer:
   case DeclContextKind::SerializedLocal:
+  case DeclContextKind::Package:
   case DeclContextKind::Module:
   case DeclContextKind::FileUnit:
   case DeclContextKind::MacroDecl:
@@ -1085,6 +1086,7 @@ ExtractCheckResult checkExtractConditions(const ResolvedRangeInfo &RangeInfo,
     break;
 
   case swift::DeclContextKind::SerializedLocal:
+  case swift::DeclContextKind::Package:
   case swift::DeclContextKind::Module:
   case swift::DeclContextKind::FileUnit:
   case swift::DeclContextKind::GenericTypeDecl:

lib/SIL/IR/SILPrinter.cpp

@@ -186,6 +186,8 @@ static void printFullContext(const DeclContext *Context, raw_ostream &Buffer) {
   if (!Context)
     return;
   switch (Context->getContextKind()) {
+  case swift::DeclContextKind::Package:
+    return;
   case DeclContextKind::Module:
     if (Context == cast<ModuleDecl>(Context)->getASTContext().TheBuiltinModule)
       Buffer << cast<ModuleDecl>(Context)->getName() << ".";