[cxx-interop] Support optional generic cases in enums

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -545,25 +545,29 @@ class DeclAndTypePrinter::Implementation
             std::tie(objectType, optKind) = getObjectTypeAndOptionality(
                 paramType->getNominalOrBoundGenericNominal(), paramType);
             auto objectTypeDecl = objectType->getNominalOrBoundGenericNominal();
+            assert(objectTypeDecl != nullptr || paramType->isOptional());
 
-            if (auto knownCxxType =
-                    owningPrinter.typeMapping.getKnownCxxTypeInfo(
-                        objectTypeDecl)) {
+            if (objectTypeDecl &&
+                owningPrinter.typeMapping.getKnownCxxTypeInfo(objectTypeDecl)) {
               outOfLineOS << "    " << types[paramType] << " result;\n";
               outOfLineOS << "    "
                              "memcpy(&result, payloadFromDestruction, "
                              "sizeof(result));\n";
               outOfLineOS << "    return result;\n  ";
             } else {
+              bool isOptional = false;
+              if (!objectTypeDecl) {
+                objectTypeDecl = paramType->getNominalOrBoundGenericNominal();
+                isOptional = true;
+              }
               outOfLineOS << "    return swift::";
               outOfLineOS << cxx_synthesis::getCxxImplNamespaceName();
               outOfLineOS << "::implClassFor<";
-              outOfLineSyntaxPrinter.printModuleNamespaceQualifiersIfNeeded(
-                  objectTypeDecl->getModuleContext(),
+              outOfLineSyntaxPrinter.printNominalTypeReference(
+                  objectTypeDecl,
                   elementDecl->getParentEnum()->getModuleContext());
-              outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
               outOfLineOS << ">::type";
-              if (isa<ClassDecl>(objectTypeDecl)) {
+              if (!isOptional && isa<ClassDecl>(objectTypeDecl)) {
                 outOfLineOS << "::makeRetained(*reinterpret_cast<void "
                                "**>(payloadFromDestruction));\n  ";
               } else {
@@ -572,10 +576,9 @@ class DeclAndTypePrinter::Implementation
                 outOfLineOS << "      swift::"
                             << cxx_synthesis::getCxxImplNamespaceName();
                 outOfLineOS << "::implClassFor<";
-                outOfLineSyntaxPrinter.printModuleNamespaceQualifiersIfNeeded(
-                    objectTypeDecl->getModuleContext(),
+                outOfLineSyntaxPrinter.printNominalTypeReference(
+                    objectTypeDecl,
                     elementDecl->getParentEnum()->getModuleContext());
-                outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
                 outOfLineOS << ">::type";
                 outOfLineOS << "::initializeWithTake(result, "
                                "payloadFromDestruction);\n";
@@ -709,14 +712,15 @@ class DeclAndTypePrinter::Implementation
                           ED, paramType);
                   auto objectTypeDecl =
                       objectType->getNominalOrBoundGenericNominal();
-                  assert(objectTypeDecl != nullptr);
+                  assert(objectTypeDecl != nullptr || paramType->isOptional());
 
-                  if (owningPrinter.typeMapping.getKnownCxxTypeInfo(
+                  if (objectTypeDecl &&
+                      owningPrinter.typeMapping.getKnownCxxTypeInfo(
                           objectTypeDecl)) {
                     outOfLineOS
                         << "    memcpy(result._getOpaquePointer(), &val, "
                            "sizeof(val));\n";
-                  } else if (isa<ClassDecl>(objectTypeDecl)) {
+                  } else if (isa_and_nonnull<ClassDecl>(objectTypeDecl)) {
                     outOfLineOS
                         << "    auto op = swift::"
                         << cxx_synthesis::getCxxImplNamespaceName()
@@ -727,46 +731,31 @@ class DeclAndTypePrinter::Implementation
                     objectTypeDecl =
                         paramType->getNominalOrBoundGenericNominal();
                     outOfLineOS << "    alignas(";
-                    outOfLineSyntaxPrinter
-                        .printModuleNamespaceQualifiersIfNeeded(
-                            objectTypeDecl->getModuleContext(),
-                            ED->getModuleContext());
-                    outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
+                    outOfLineSyntaxPrinter.printNominalTypeReference(
+                        objectTypeDecl, ED->getModuleContext());
                     outOfLineOS << ") unsigned char buffer[sizeof(";
-                    outOfLineSyntaxPrinter
-                        .printModuleNamespaceQualifiersIfNeeded(
-                            objectTypeDecl->getModuleContext(),
-                            ED->getModuleContext());
-                    outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
+                    outOfLineSyntaxPrinter.printNominalTypeReference(
+                        objectTypeDecl, ED->getModuleContext());
                     outOfLineOS << ")];\n";
                     outOfLineOS << "    auto *valCopy = new(buffer) ";
-                    outOfLineSyntaxPrinter
-                        .printModuleNamespaceQualifiersIfNeeded(
-                            objectTypeDecl->getModuleContext(),
-                            ED->getModuleContext());
-                    outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
+                    outOfLineSyntaxPrinter.printNominalTypeReference(
+                        objectTypeDecl, ED->getModuleContext());
                     outOfLineOS << "(val);\n";
                     outOfLineOS << "    ";
                     outOfLineOS << cxx_synthesis::getCxxSwiftNamespaceName()
                                 << "::";
                     outOfLineOS << cxx_synthesis::getCxxImplNamespaceName();
                     outOfLineOS << "::implClassFor<";
-                    outOfLineSyntaxPrinter
-                        .printModuleNamespaceQualifiersIfNeeded(
-                            objectTypeDecl->getModuleContext(),
-                            ED->getModuleContext());
-                    outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
+                    outOfLineSyntaxPrinter.printNominalTypeReference(
+                        objectTypeDecl, ED->getModuleContext());
                     outOfLineOS << ">::type::initializeWithTake(result._"
                                    "getOpaquePointer(), ";
                     outOfLineOS << cxx_synthesis::getCxxSwiftNamespaceName()
                                 << "::";
                     outOfLineOS << cxx_synthesis::getCxxImplNamespaceName();
                     outOfLineOS << "::implClassFor<";
-                    outOfLineSyntaxPrinter
-                        .printModuleNamespaceQualifiersIfNeeded(
-                            objectTypeDecl->getModuleContext(),
-                            ED->getModuleContext());
-                    outOfLineSyntaxPrinter.printBaseName(objectTypeDecl);
+                    outOfLineSyntaxPrinter.printNominalTypeReference(
+                        objectTypeDecl, ED->getModuleContext());
                     outOfLineOS << ">::type::getOpaquePointer(*valCopy)";
                     outOfLineOS << ");\n";
                   }
@@ -2914,9 +2903,6 @@ static bool isEnumExposableToCxx(const ValueDecl *VD,
       if (auto *params = elementDecl->getParameterList()) {
         for (const auto *param : *params) {
           auto paramType = param->getInterfaceType();
-          // TODO: properly support exporting these optionals. rdar://131112273 
-          if (paramType->isOptional() && paramType->getOptionalObjectType()->isTypeParameter())
-            return false;
           if (DeclAndTypeClangFunctionPrinter::getTypeRepresentation(
                   printer.getTypeMapping(), printer.getInteropContext(),
                   printer, enumDecl->getModuleContext(), paramType)

lib/PrintAsClang/PrintClangValueType.cpp

@@ -622,7 +622,7 @@ void ClangValueTypePrinter::printTypeGenericTraits(
   os << "namespace swift SWIFT_PRIVATE_ATTR {\n";
 
   if (typeDecl->hasClangNode()) {
-    /// Print a reference to the type metadata fucntion for a C++ type.
+    /// Print a reference to the type metadata function for a C++ type.
     ClangSyntaxPrinter(os).printNamespace(
         cxx_synthesis::getCxxImplNamespaceName(), [&](raw_ostream &os) {
           ClangSyntaxPrinter(os).printCTypeMetadataTypeFunction(
@@ -696,20 +696,23 @@ void ClangValueTypePrinter::printTypeGenericTraits(
     os << "> = true;\n";
   }
 
-  // FIXME: generic support.
-  if (!typeDecl->hasClangNode() && typeMetadataFuncRequirements.empty()) {
+  if (!typeDecl->hasClangNode()) {
     assert(NTD);
-    os << "template<>\n";
+    if (printer.printNominalTypeOutsideMemberDeclTemplateSpecifiers(NTD))
+      os << "template<>\n";
     os << "struct";
     declAndTypePrinter.printAvailability(os, typeDecl);
     os << " implClassFor<";
     printer.printBaseName(typeDecl->getModuleContext());
     os << "::";
-    printer.printBaseName(typeDecl);
+    printer.printNominalTypeReference(NTD, moduleContext);
     os << "> { using type = ";
     printer.printBaseName(typeDecl->getModuleContext());
     os << "::" << cxx_synthesis::getCxxImplNamespaceName() << "::";
     printCxxImplClassName(os, NTD);
+    if (NTD->isGeneric())
+      printer.printGenericSignatureParams(
+          NTD->getGenericSignature().getCanonicalSignature());
     os << "; };\n";
   }
   os << "} // namespace\n";

test/Interop/SwiftToCxx/generics/generic-enum-execution.cpp

@@ -123,6 +123,13 @@ int main() {
     // CHECK-NEXT: after some
     // CHECK-NEXT: destroy-TracksDeinit
   }
+  {
+    auto opt = swift::Optional<int>::some(14);
+    auto x = GenericCustomType<int>::success(opt);
+    auto y = x;
+    assert(y.isSuccess());
+    assert(y.getSuccess().getSome() == 14);
+  }
   puts("EOF");
   // CHECK-NEXT: EOF
   return 0;

test/Interop/SwiftToCxx/generics/generic-enum-in-cxx.swift

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend %s -typecheck -module-name Generics -clang-header-expose-decls=all-public -emit-clang-header-path %t/generics.h
+// RUN: %target-swift-frontend %s -typecheck -module-name Generics -enable-experimental-cxx-interop -emit-clang-header-path %t/generics.h
 // RUN: %FileCheck %s < %t/generics.h
 // RUN: %check-interop-cxx-header-in-clang(%t/generics.h -Wno-reserved-identifier -DSWIFT_CXX_INTEROP_HIDE_STL_OVERLAY)
 
@@ -96,6 +96,16 @@ public func inoutConcreteOpt(_ x: inout GenericOpt<UInt16>) {
 
 // CHECK: namespace Generics SWIFT_PRIVATE_ATTR SWIFT_SYMBOL_MODULE("Generics") {
 
+// CHECK: template<class T_0_0>
+// CHECK-NEXT: #ifdef __cpp_concepts
+// CHECK-NEXT: requires swift::isUsableInGenericContext<T_0_0>
+// CHECK-NEXT: #endif
+// CHECK-NEXT: class SWIFT_SYMBOL("s:8Generics17GenericCustomTypeO") GenericCustomType;
+
+// CHECK: static inline const constexpr bool isOpaqueLayout<Generics::GenericCustomType<T_0_0>> = true;
+
+// CHECK: template<class T_0_0>
+
 // CHECK: template<class T_0_0>
 // CHECK-NEXT: #ifdef __cpp_concepts
 // CHECK-NEXT: requires swift::isUsableInGenericContext<T_0_0>
@@ -218,6 +228,8 @@ public func inoutConcreteOpt(_ x: inout GenericOpt<UInt16>) {
 // CHECK-NEXT:   _impl::$s8Generics14takeGenericOptyyAA0cD0OyxGlF(_impl::_impl_GenericOpt<T_0_0>::getOpaquePointer(x), swift::TypeMetadataTrait<T_0_0>::getTypeMetadata());
 // CHECK-NEXT: }
 
+// CHECK: SWIFT_INLINE_THUNK  bool GenericCustomType<T_0_0>::isFailure() const {
+
 // CHECK: template<class T_0_0>
 // CHECK-NEXT: #ifdef __cpp_concepts
 // CHECK-NEXT: requires swift::isUsableInGenericContext<T_0_0>

test/Interop/SwiftToCxx/generics/generic-struct-in-cxx.swift

@@ -285,6 +285,11 @@ public func inoutConcretePair(_ x: UInt16, _ y: inout GenericPair<UInt16, UInt16
 // CHECK-NEXT: requires swift::isUsableInGenericContext<T_0_0> && swift::isUsableInGenericContext<T_0_1>
 // CHECK-NEXT: #endif // __cpp_concepts
 // CHECK-NEXT: static inline const constexpr bool isOpaqueLayout<Generics::GenericPair<T_0_0, T_0_1>> = true;
+// CHECK-NEXT: template<class T_0_0, class T_0_1>
+// CHECK-NEXT: #ifdef __cpp_concepts
+// CHECK-NEXT:  requires swift::isUsableInGenericContext<T_0_0> && swift::isUsableInGenericContext<T_0_1>
+// CHECK-NEXT: #endif // __cpp_concepts
+// CHECK-NEXT: struct implClassFor<Generics::GenericPair<T_0_0, T_0_1>> { using type = Generics::_impl::_impl_GenericPair<T_0_0, T_0_1>; }
 // CHECK-NEXT: } // namespace
 // CHECK-NEXT: #pragma clang diagnostic pop
 // CHECK-NEXT: } // namespace swift

test/Interop/SwiftToCxx/stdlib/swift-stdlib-in-cxx.swift

@@ -46,6 +46,7 @@
 // CHECK: template<class T_0_0>
 // CHECK: template<class T_0_0>
 
+// CHECK: template<class T_0_0>
 // CHECK: template<class T_0_0>
 // CHECK: template<class T_0_0>
 // CHECK-NEXT: #ifdef __cpp_concepts