[cxx-interop] Rudimentary support for importing base classes.

This commit adds very basic support for importing and calling base class methods, getting and setting base class fields, and using types inside of base classes.

Author: zoecarver

include/swift/AST/ClangModuleLoader.h

@@ -268,7 +268,7 @@ class ClangModuleLoader : public ModuleLoader {
              clang::DeclarationName givenName = clang::DeclarationName()) = 0;
 
   /// Determine the effective Clang context for the given Swift nominal type.
-  EffectiveClangContext virtual getEffectiveClangContext(
+  virtual EffectiveClangContext getEffectiveClangContext(
       const NominalTypeDecl *nominal) = 0;
 };
 

lib/ClangImporter/ClangImporter.cpp

@@ -692,7 +692,7 @@ static AccessorDecl *makeStructRawValueGetter(
   assert(storedVar->hasStorage());
 
   ASTContext &C = Impl.SwiftContext;
-  
+
   auto *params = ParameterList::createEmpty(C);
 
   auto computedType = computedVar->getInterfaceType();
@@ -726,7 +726,7 @@ static AccessorDecl *makeFieldGetterDecl(ClangImporter::Implementation &Impl,
   auto &C = Impl.SwiftContext;
 
   auto *params = ParameterList::createEmpty(C);
-  
+
   auto getterType = importedFieldDecl->getInterfaceType();
   auto getterDecl = AccessorDecl::create(C,
                      /*FuncLoc=*/importedFieldDecl->getLoc(),
@@ -1152,7 +1152,7 @@ makeBitFieldAccessors(ClangImporter::Implementation &Impl,
                                          cSetterParamTypes,
                                          clang::FunctionProtoType::ExtProtoInfo());
   auto cSetterTypeInfo = Ctx.getTrivialTypeSourceInfo(cSetterType);
-  
+
   auto cSetterDecl = clang::FunctionDecl::Create(Ctx,
                                                  structDecl->getDeclContext(),
                                                  clang::SourceLocation(),
@@ -1184,7 +1184,7 @@ makeBitFieldAccessors(ClangImporter::Implementation &Impl,
                                                   clang::SC_None,
                                                   nullptr);
     cGetterDecl->setParams(cGetterSelf);
-    
+
     auto cGetterSelfExpr = new (Ctx) clang::DeclRefExpr(Ctx, cGetterSelf, false,
                                                         recordType,
                                                         clang::VK_PRValue,
@@ -1197,7 +1197,7 @@ makeBitFieldAccessors(ClangImporter::Implementation &Impl,
                                                          clang::VK_PRValue,
                                                          clang::OK_BitField);
 
-    
+
     auto cGetterBody = clang::ReturnStmt::Create(Ctx, clang::SourceLocation(),
                                                    cGetterExpr,
                                                    nullptr);
@@ -1228,20 +1228,20 @@ makeBitFieldAccessors(ClangImporter::Implementation &Impl,
                                                   nullptr);
     cSetterParams.push_back(cSetterSelf);
     cSetterDecl->setParams(cSetterParams);
-    
+
     auto cSetterSelfExpr = new (Ctx) clang::DeclRefExpr(Ctx, cSetterSelf, false,
                                                         recordPointerType,
                                                         clang::VK_PRValue,
                                                         clang::SourceLocation());
-    
+
     auto cSetterMemberExpr = clang::MemberExpr::CreateImplicit(Ctx,
                                                                cSetterSelfExpr,
                                                                /*isarrow=*/true,
                                                                fieldDecl,
                                                                fieldType,
                                                                clang::VK_LValue,
                                                                clang::OK_BitField);
-    
+
     auto cSetterValueExpr = new (Ctx) clang::DeclRefExpr(Ctx, cSetterValue, false,
                                                          fieldType,
                                                          clang::VK_PRValue,
@@ -1256,7 +1256,7 @@ makeBitFieldAccessors(ClangImporter::Implementation &Impl,
                                                      clang::OK_Ordinary,
                                                      clang::SourceLocation(),
                                                      clang::FPOptionsOverride());
-    
+
     cSetterDecl->setBody(cSetterExpr);
   }
 
@@ -2419,7 +2419,7 @@ namespace {
         if (auto *typedefForAnon = decl->getTypedefNameForAnonDecl())
           return importFullName(typedefForAnon);
       }
-      
+
       return {ImportedName(), None};
     }
 
@@ -2806,7 +2806,7 @@ namespace {
         });
 
       Result->setUnderlyingType(SwiftType);
-      
+
       // Make Objective-C's 'id' unavailable.
       if (Impl.SwiftContext.LangOpts.EnableObjCInterop && isObjCId(Decl)) {
         auto attr = AvailableAttr::createPlatformAgnostic(
@@ -2882,7 +2882,7 @@ namespace {
           Impl.importDeclContextOf(decl, importedName.getEffectiveContext());
       if (!dc)
         return nullptr;
-      
+
       auto name = importedName.getDeclName().getBaseIdentifier();
 
       // Create the enum declaration and record it.
@@ -2948,7 +2948,7 @@ namespace {
         ProtocolDecl *bridgedNSError = nullptr;
         ClassDecl *nsErrorDecl = nullptr;
         ProtocolDecl *errorCodeProto = nullptr;
-        if (enumInfo.isErrorEnum() && 
+        if (enumInfo.isErrorEnum() &&
             (bridgedNSError =
                C.getProtocol(KnownProtocolKind::BridgedStoredNSError)) &&
             (nsErrorDecl = C.getNSErrorDecl()) &&
@@ -3124,7 +3124,7 @@ namespace {
       Impl.ImportedDecls[{canonicalClangDecl, getVersion()}] = result;
 
       // Import each of the enumerators.
-      
+
       bool addEnumeratorsAsMembers;
       switch (enumKind) {
       case EnumKind::Constants:
@@ -3282,7 +3282,7 @@ namespace {
           addDecl(result, enumeratorDecl);
           for (auto *variant : variantDecls)
             addDecl(result, variant);
-          
+
           // If there is an error wrapper, add an alias within the
           // wrapper to the corresponding value within the enumerator
           // context.
@@ -3334,7 +3334,7 @@ namespace {
       // Track whether this record contains fields we can't reference in Swift
       // as stored properties.
       bool hasUnreferenceableStorage = false;
-      
+
       // Track whether this record contains fields that can't be zero-
       // initialized.
       bool hasZeroInitializableStorage = true;
@@ -3576,6 +3576,12 @@ namespace {
 
       const clang::CXXRecordDecl *cxxRecordDecl =
           dyn_cast<clang::CXXRecordDecl>(decl);
+      bool hasBaseClasses = cxxRecordDecl && !cxxRecordDecl->bases().empty();
+      if (hasBaseClasses) {
+        hasUnreferenceableStorage = true;
+        hasMemberwiseInitializer = false;
+      }
+
       if (hasZeroInitializableStorage && !cxxRecordDecl) {
         // Add default constructor for the struct if compiling in C mode.
         // If we're compiling for C++, we'll import the C++ default constructor
@@ -4212,10 +4218,10 @@ namespace {
         DeclName ctorName(Impl.SwiftContext, DeclBaseName::createConstructor(),
                           bodyParams);
         result = Impl.createDeclWithClangNode<ConstructorDecl>(
-            clangNode, AccessLevel::Public, ctorName, loc, 
+            clangNode, AccessLevel::Public, ctorName, loc,
             /*failable=*/false, /*FailabilityLoc=*/SourceLoc(),
             /*Async=*/false, /*AsyncLoc=*/SourceLoc(),
-            /*Throws=*/false, /*ThrowsLoc=*/SourceLoc(), 
+            /*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
             bodyParams, genericParams, dc);
       } else {
         auto resultTy = importedType.getType();
@@ -4592,33 +4598,33 @@ namespace {
       // Only import types for now.
       if (!isa<clang::TypeDecl>(decl->getUnderlyingDecl()))
         return nullptr;
-        
+
       ImportedName importedName;
       Optional<ImportedName> correctSwiftName;
       std::tie(importedName, correctSwiftName) = importFullName(decl);
       auto Name = importedName.getDeclName().getBaseIdentifier();
       if (Name.empty())
         return nullptr;
-      
+
       // If we've been asked to produce a compatibility stub, handle it via a
       // typealias.
       if (correctSwiftName)
         return importCompatibilityTypeAlias(decl, importedName,
                                             *correctSwiftName);
-      
+
       auto DC =
           Impl.importDeclContextOf(decl, importedName.getEffectiveContext());
       if (!DC)
         return nullptr;
-      
+
       Decl *SwiftDecl = Impl.importDecl(decl->getUnderlyingDecl(), getActiveSwiftVersion());
       if (!SwiftDecl)
         return nullptr;
 
       const TypeDecl *SwiftTypeDecl = dyn_cast<TypeDecl>(SwiftDecl);
       if (!SwiftTypeDecl)
         return nullptr;
-      
+
       auto Loc = Impl.importSourceLoc(decl->getLocation());
       auto Result = Impl.createDeclWithClangNode<TypeAliasDecl>(
           decl,
@@ -5286,7 +5292,7 @@ namespace {
                                               objcClass->getDeclaredType());
       Impl.SwiftContext.evaluator.cacheOutput(ExtendedNominalRequest{result},
                                               std::move(objcClass));
-      
+
       // Determine the type and generic args of the extension.
       if (objcClass->getGenericParams()) {
         result->setGenericSignature(objcClass->getGenericSignature());
@@ -5305,7 +5311,7 @@ namespace {
     }
 
     template <typename T, typename U>
-    T *resolveSwiftDeclImpl(const U *decl, Identifier name, 
+    T *resolveSwiftDeclImpl(const U *decl, Identifier name,
                             bool hasKnownSwiftName, ModuleDecl *overlay) {
       const auto &languageVersion =
           Impl.SwiftContext.LangOpts.EffectiveLanguageVersion;
@@ -6178,7 +6184,7 @@ Decl *SwiftDeclConverter::importCompatibilityTypeAlias(
   }
 
   alias->setUnderlyingType(typeDecl->getDeclaredInterfaceType());
-  
+
   // Record that this is the official version of this declaration.
   Impl.ImportedDecls[{decl->getCanonicalDecl(), getVersion()}] = alias;
   markAsVariant(alias, correctSwiftName);
@@ -9335,7 +9341,7 @@ ClangImporter::Implementation::importMirroredDecl(const clang::NamedDecl *decl,
 
     auto updateMirroredDecl = [&](Decl *result) {
       result->setImplicit();
-    
+
       // Map the Clang attributes onto Swift attributes.
       importAttributes(decl, result);
 
@@ -9926,10 +9932,10 @@ static void loadAllMembersOfSuperclassIfNeeded(ClassDecl *CD) {
     E->loadAllMembers();
 }
 
-void ClangImporter::Implementation::loadAllMembersOfRecordDecl(
-    NominalTypeDecl *recordDecl) {
-  auto clangRecord = cast<clang::RecordDecl>(recordDecl->getClangDecl());
+ValueDecl *cloneBaseMemberDecl(ValueDecl *decl, DeclContext *newContext);
 
+void ClangImporter::Implementation::loadAllMembersOfRecordDecl(
+    NominalTypeDecl *swiftDecl, const clang::RecordDecl *clangRecord) {
   // Import all of the members.
   llvm::SmallVector<Decl *, 16> members;
   for (const clang::Decl *m : clangRecord->decls()) {
@@ -9955,12 +9961,36 @@ void ClangImporter::Implementation::loadAllMembersOfRecordDecl(
 
   // Add the members here.
   for (auto member: members) {
+    // This means we found a member in a C++ record's base class.
+    if (swiftDecl->getClangDecl() != clangRecord) {
+      // So we need to clone the member into the derived class.
+      if (auto newDecl = cloneBaseMemberDecl(cast<ValueDecl>(member), swiftDecl)) {
+        swiftDecl->addMember(newDecl);
+      }
+      continue;
+    }
+
     // FIXME: constructors are added eagerly, but shouldn't be
     // FIXME: subscripts are added eagerly, but shouldn't be
     if (!isa<AccessorDecl>(member) &&
         !isa<SubscriptDecl>(member) &&
-        !isa<ConstructorDecl>(member))
-      recordDecl->addMember(member);
+        !isa<ConstructorDecl>(member)) {
+      swiftDecl->addMember(member);
+    }
+  }
+
+  // If this is a C++ record, look through the base classes too.
+  if (auto cxxRecord = dyn_cast<clang::CXXRecordDecl>(clangRecord)) {
+    for (auto base : cxxRecord->bases()) {
+      clang::QualType baseType = base.getType();
+      if (auto spectType = dyn_cast<clang::TemplateSpecializationType>(baseType))
+        baseType = spectType->desugar();
+      if (!isa<clang::RecordType>(baseType))
+        continue;
+
+      auto *baseRecord = cast<clang::RecordType>(baseType)->getDecl();
+      loadAllMembersOfRecordDecl(swiftDecl, baseRecord);
+    }
   }
 }
 
@@ -9996,7 +10026,8 @@ ClangImporter::Implementation::loadAllMembers(Decl *D, uint64_t extra) {
   }
 
   if (isa_and_nonnull<clang::RecordDecl>(D->getClangDecl())) {
-    loadAllMembersOfRecordDecl(cast<NominalTypeDecl>(D));
+    loadAllMembersOfRecordDecl(cast<NominalTypeDecl>(D),
+                               cast<clang::RecordDecl>(D->getClangDecl()));
     return;
   }
 

lib/ClangImporter/ImportDecl.cpp

@@ -1460,7 +1460,8 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
   void
   loadAllMembersOfObjcContainer(Decl *D,
                                 const clang::ObjCContainerDecl *objcContainer);
-  void loadAllMembersOfRecordDecl(NominalTypeDecl *recordDecl);
+  void loadAllMembersOfRecordDecl(NominalTypeDecl *swiftDecl,
+                                  const clang::RecordDecl *clangRecord);
 
   void collectMembersToAdd(const clang::ObjCContainerDecl *objcContainer,
                            Decl *D, DeclContext *DC,