[interop][SwiftToCxx] expose generic type traits for C++ types in gen…

lib/PrintAsClang/ModuleContentsWriter.cpp

@@ -126,6 +126,7 @@ class ModuleWriter {
   ModuleDecl &M;
 
   llvm::DenseMap<const TypeDecl *, std::pair<EmissionState, bool>> seenTypes;
+  llvm::DenseSet<const NominalTypeDecl *> seenClangTypes;
   std::vector<const Decl *> declsToWrite;
   DelayedMemberSet delayedMembers;
   PrimitiveTypeMapping typeMapping;
@@ -267,13 +268,22 @@ class ModuleWriter {
     });
   }
 
+  void emitReferencedClangTypeMetadata(const NominalTypeDecl *typeDecl) {
+    auto it = seenClangTypes.insert(typeDecl);
+    if (it.second)
+      ClangValueTypePrinter::printClangTypeSwiftGenericTraits(os, typeDecl, &M);
+  }
+
   void forwardDeclareType(const TypeDecl *TD) {
     if (outputLangMode == OutputLanguageMode::Cxx) {
       if (isa<StructDecl>(TD) || isa<EnumDecl>(TD)) {
         auto *NTD = cast<NominalTypeDecl>(TD);
         if (!addImport(NTD)) {
           forwardDeclare(
               NTD, [&]() { ClangValueTypePrinter::forwardDeclType(os, NTD); });
+        } else {
+          if (isa<StructDecl>(TD) && NTD->hasClangNode())
+            emitReferencedClangTypeMetadata(NTD);
         }
       }
       return;
@@ -703,11 +713,6 @@ class ModuleWriter {
 
     // Print any out of line definitions.
     os << outOfLineDefinitionsOS.str();
-
-    // Print any additional metadata for referenced C++ types.
-    for (const auto *typeDecl :
-         printer.getInteropContext().getEmittedClangTypeDecls())
-      ClangValueTypePrinter::printClangTypeSwiftGenericTraits(os, typeDecl, &M);
   }
 };
 } // end anonymous namespace

lib/PrintAsClang/PrintClangFunction.cpp

@@ -312,7 +312,6 @@ class CFunctionSignatureTypePrinter
       handler.printTypeName(os);
       if (typeUseKind == FunctionSignatureTypeUse::ParamType)
         os << '&';
-      interopContext.recordEmittedClangTypeDecl(decl);
       return ClangRepresentation::representable;
     }
 

lib/PrintAsClang/SwiftToClangInteropContext.cpp

@@ -35,12 +35,6 @@ void SwiftToClangInteropContext::runIfStubForDeclNotEmitted(
     function();
 }
 
-void SwiftToClangInteropContext::recordEmittedClangTypeDecl(
-    const NominalTypeDecl *typeDecl) {
-  assert(typeDecl->hasClangNode());
-  referencedClangTypeDecls.insert(typeDecl);
-}
-
 void SwiftToClangInteropContext::recordExtensions(
     const NominalTypeDecl *typeDecl, const ExtensionDecl *ext) {
   auto it = extensions.insert(

lib/PrintAsClang/SwiftToClangInteropContext.h

@@ -17,7 +17,6 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/StringSet.h"
 #include <memory>
 
@@ -46,15 +45,6 @@ class SwiftToClangInteropContext {
   void runIfStubForDeclNotEmitted(llvm::StringRef stubName,
                                   llvm::function_ref<void(void)> function);
 
-  /// Records that the given nominal type decl that has a clang declaration was
-  /// emitted in the generated header.
-  void recordEmittedClangTypeDecl(const NominalTypeDecl *typeDecl);
-
-  inline const llvm::SetVector<const NominalTypeDecl *> &
-  getEmittedClangTypeDecls() const {
-    return referencedClangTypeDecls;
-  }
-
   void recordExtensions(const NominalTypeDecl *typeDecl,
                         const ExtensionDecl *ext);
 
@@ -66,7 +56,6 @@ class SwiftToClangInteropContext {
   const IRGenOptions &irGenOpts;
   std::unique_ptr<IRABIDetailsProvider> irABIDetails;
   llvm::StringSet<> emittedStubs;
-  llvm::SetVector<const NominalTypeDecl *> referencedClangTypeDecls;
   llvm::DenseMap<const NominalTypeDecl *, std::vector<const ExtensionDecl *>>
       extensions;
 };

test/Interop/CxxToSwiftToCxx/bridge-cxx-struct-back-to-cxx-execution.cpp

@@ -1,6 +1,8 @@
 // RUN: %empty-directory(%t)
 // RUN: split-file %s %t
 
+// RUN: %target-swift-frontend -parse-as-library %platform-module-dir/Swift.swiftmodule/%module-target-triple.swiftinterface -enable-library-evolution -disable-objc-attr-requires-foundation-module -typecheck -module-name Swift -parse-stdlib -enable-experimental-cxx-interop -emit-clang-header-path %t/Swift.h  -experimental-skip-all-function-bodies
+
 // RUN: %target-swift-frontend -typecheck %t/use-cxx-types.swift -typecheck -module-name UseCxx -emit-clang-header-path %t/UseCxx.h -I %t -enable-experimental-cxx-interop -clang-header-expose-public-decls
 
 // RUN: %target-interop-build-clangxx -std=c++20 -c %t/use-swift-cxx-types.cpp -I %t -o %t/swift-cxx-execution.o -g
@@ -88,9 +90,14 @@ public func retPassThroughGeneric<T>(_ x: T) -> T {
     return x
 }
 
+public func retArrayNonTrivial(_ x: CInt) -> [NonTrivialTemplate<Trivial>] {
+    return [NonTrivialTemplate<Trivial>(Trivial(x, -x))]
+}
+
 //--- use-swift-cxx-types.cpp
 
 #include "header.h"
+#include "Swift.h"
 #include "UseCxx.h"
 #include <assert.h>
 
@@ -134,7 +141,6 @@ int main() {
     }
     puts("secondon non trivial");
   }
-  puts("EndOfTest");
 // CHECK-NEXT: create NonTrivialTemplate
 // CHECK-NEXT: move NonTrivialTemplate
 // CHECK-NEXT: ~NonTrivialTemplate
@@ -158,6 +164,19 @@ int main() {
 // CHECK-NEXT: ~NonTrivialTemplate
 // CHECK-NEXT: secondon non trivial
 // CHECK-NEXT: ~NonTrivialTemplate
+  {
+    auto arr = UseCxx::retArrayNonTrivial(1234);
+    auto val = arr[0];
+    assert(val.x.x == 1234);
+    assert(val.x.y == -1234);
+  }
+// CHECK-NEXT: create NonTrivialTemplate
+// CHECK-NEXT: copy NonTrivialTemplate
+// CHECK-NEXT: move NonTrivialTemplate
+// CHECK-NEXT: ~NonTrivialTemplate
+// CHECK-NEXT: ~NonTrivialTemplate
+// CHECK-NEXT: ~NonTrivialTemplate
+  puts("EndOfTest");
 // CHECK-NEXT: EndOfTest
   return 0;
 }

test/Interop/CxxToSwiftToCxx/bridge-cxx-struct-back-to-cxx.swift

@@ -92,6 +92,36 @@ public func takeTrivialInout(_ x: inout Trivial) {
 // CHECK: SWIFT_EXTERN void $s8UseCxxTy13retNonTrivialSo2nsO02__b18TemplateInstN2ns18efH4IiEEVyF(SWIFT_INDIRECT_RESULT void * _Nonnull) SWIFT_NOEXCEPT SWIFT_CALL; // retNonTrivial()
 // CHECK: SWIFT_EXTERN struct swift_interop_returnStub_UseCxxTy_uint32_t_0_4 $s8UseCxxTy10retTrivialSo0E0VyF(void) SWIFT_NOEXCEPT SWIFT_CALL; // retTrivial()
 
+// CHECK: } // end namespace
+// CHECK-EMPTY:
+// CHECK-NEXT: namespace swift {
+// CHECK-NEXT: namespace _impl {
+// CHECK-EMPTY:
+// CHECK-NEXT: // Type metadata accessor for __CxxTemplateInstN2ns18NonTrivialTemplateIiEE
+// CHECK-NEXT: SWIFT_EXTERN swift::_impl::MetadataResponseTy $sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC4IiEEVMa(swift::_impl::MetadataRequestTy) SWIFT_NOEXCEPT SWIFT_CALL;
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-NEXT: } // namespace _impl
+// CHECK-EMPTY:
+// CHECK-NEXT: #pragma clang diagnostic push
+// CHECK-NEXT: #pragma clang diagnostic ignored "-Wc++17-extensions"
+// CHECK-NEXT: template<>
+// CHECK-NEXT: static inline const constexpr bool isUsableInGenericContext<ns::NonTrivialTemplate<int>> = true;
+// CHECK-NEXT: template<>
+// CHECK-NEXT: struct TypeMetadataTrait<ns::NonTrivialTemplate<int>> {
+// CHECK-NEXT:   static inline void * _Nonnull getTypeMetadata() {
+// CHECK-NEXT:     return _impl::$sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC4IiEEVMa(0)._0;
+// CHECK-NEXT:   }
+// CHECK-NEXT: };
+// CHECK-NEXT: namespace _impl{
+// CHECK-NEXT: template<>
+// CHECK-NEXT: static inline const constexpr bool isSwiftBridgedCxxRecord<ns::NonTrivialTemplate<int>> = true;
+// CHECK-NEXT: } // namespace
+// CHECK-NEXT: #pragma clang diagnostic pop
+// CHECK-NEXT: } // namespace swift
+// CHECK-EMPTY:
+// CHECK-NEXT: namespace UseCxxTy {
+
 // CHECK: inline ns::NonTrivialTemplate<int> retNonTrivial() noexcept SWIFT_WARN_UNUSED_RESULT {
 // CHECK-NEXT: alignas(alignof(ns::NonTrivialTemplate<int>)) char storage[sizeof(ns::NonTrivialTemplate<int>)];
 // CHECK-NEXT: auto * _Nonnull storageObjectPtr = reinterpret_cast<ns::NonTrivialTemplate<int> *>(storage);
@@ -101,8 +131,37 @@ public func takeTrivialInout(_ x: inout Trivial) {
 // CHECK-NEXT: return result;
 // CHECK-NEXT: }
 // CHECK-EMPTY:
+// CHECK-NEXT: } // end namespace
+// CHECK-EMPTY:
+// CHECK-NEXT: namespace swift {
+// CHECK-NEXT: namespace _impl {
+// CHECK-EMPTY:
+// CHECK-NEXT: // Type metadata accessor for __CxxTemplateInstN2ns18NonTrivialTemplateINS_11TrivialinNSEEE
+// CHECK-NEXT: SWIFT_EXTERN swift::_impl::MetadataResponseTy $sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC20INS_11TrivialinNSEEEVMa(swift::_impl::MetadataRequestTy) SWIFT_NOEXCEPT SWIFT_CALL;
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-NEXT: } // namespace _impl
+// CHECK-EMPTY:
+// CHECK-NEXT: #pragma clang diagnostic push
+// CHECK-NEXT: #pragma clang diagnostic ignored "-Wc++17-extensions"
+// CHECK-NEXT: template<>
+// CHECK-NEXT: static inline const constexpr bool isUsableInGenericContext<ns::NonTrivialTemplate<ns::TrivialinNS>> = true;
+// CHECK-NEXT: template<>
+// CHECK-NEXT: struct TypeMetadataTrait<ns::NonTrivialTemplate<ns::TrivialinNS>> {
+// CHECK-NEXT:   static inline void * _Nonnull getTypeMetadata() {
+// CHECK-NEXT:     return _impl::$sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC20INS_11TrivialinNSEEEVMa(0)._0;
+// CHECK-NEXT:   }
+// CHECK-NEXT: };
+// CHECK-NEXT: namespace _impl{
+// CHECK-NEXT: template<>
+// CHECK-NEXT: static inline const constexpr bool isSwiftBridgedCxxRecord<ns::NonTrivialTemplate<ns::TrivialinNS>> = true;
+// CHECK-NEXT: } // namespace
+// CHECK-NEXT: #pragma clang diagnostic pop
+// CHECK-NEXT: } // namespace swift
+// CHECK-EMPTY:
+// CHECK-NEXT: namespace UseCxxTy {
 // CHECK-EMPTY:
-// CHECK: inline ns::NonTrivialTemplate<ns::TrivialinNS> retNonTrivial2() noexcept SWIFT_WARN_UNUSED_RESULT {
+// CHECK-NEXT: inline ns::NonTrivialTemplate<ns::TrivialinNS> retNonTrivial2() noexcept SWIFT_WARN_UNUSED_RESULT {
 // CHECK-NEXT: alignas(alignof(ns::NonTrivialTemplate<ns::TrivialinNS>)) char storage[sizeof(ns::NonTrivialTemplate<ns::TrivialinNS>)];
 // CHECK-NEXT: auto * _Nonnull storageObjectPtr = reinterpret_cast<ns::NonTrivialTemplate<ns::TrivialinNS> *>(storage);
 // CHECK-NEXT: _impl::$s8UseCxxTy14retNonTrivial2So2nsO02__b18TemplateInstN2ns18e7TrivialH20INS_11TrivialinNSEEEVyF(storage);
@@ -140,33 +199,3 @@ public func takeTrivialInout(_ x: inout Trivial) {
 // CHECK: inline void takeTrivialInout(Trivial& x) noexcept {
 // CHECK-NEXT:   return _impl::$s8UseCxxTy16takeTrivialInoutyySo0E0VzF(swift::_impl::getOpaquePointer(x));
 // CHECK-NEXT: }
-
-// CHECK: } // end namespace
-// CHECK-EMPTY:
-// CHECK-NEXT: namespace swift {
-// CHECK-NEXT: namespace _impl {
-// CHECK-EMPTY:
-// CHECK-NEXT: // Type metadata accessor for __CxxTemplateInstN2ns18NonTrivialTemplateIiEE
-// CHECK-NEXT: SWIFT_EXTERN swift::_impl::MetadataResponseTy $sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC4IiEEVMa(swift::_impl::MetadataRequestTy) SWIFT_NOEXCEPT SWIFT_CALL;
-// CHECK-EMPTY:
-// CHECK-EMPTY:
-// CHECK-NEXT: } // namespace _impl
-// CHECK-EMPTY:
-// CHECK-NEXT: #pragma clang diagnostic push
-// CHECK-NEXT: #pragma clang diagnostic ignored "-Wc++17-extensions"
-// CHECK-NEXT: template<>
-// CHECK-NEXT: static inline const constexpr bool isUsableInGenericContext<ns::NonTrivialTemplate<int>> = true;
-// CHECK-NEXT: template<>
-// CHECK-NEXT: struct TypeMetadataTrait<ns::NonTrivialTemplate<int>> {
-// CHECK-NEXT:   static inline void * _Nonnull getTypeMetadata() {
-// CHECK-NEXT:     return _impl::$sSo2nsO033__CxxTemplateInstN2ns18NonTrivialC4IiEEVMa(0)._0;
-// CHECK-NEXT:   }
-// CHECK-NEXT: };
-// CHECK-NEXT: namespace _impl{
-// CHECK-NEXT: template<>
-// CHECK-NEXT: static inline const constexpr bool isSwiftBridgedCxxRecord<ns::NonTrivialTemplate<int>> = true;
-// CHECK-NEXT: } // namespace
-// CHECK-NEXT: #pragma clang diagnostic pop
-// CHECK-NEXT: } // namespace swift
-// CHECK-EMPTY:
-// CHECK-NEXT: namespace UseCxxTy {