[interop][SwiftToCxx] pass class parameter types by 'inout'

Author: hyp

lib/PrintAsClang/PrintClangClassType.cpp

@@ -76,6 +76,9 @@ void ClangClassTypePrinter::printClassTypeDecl(
         os << "static inline void * _Nonnull getOpaquePointer(const ";
         printer.printBaseName(typeDecl);
         os << " &object) noexcept { return object._opaquePointer; }\n";
+        os << "static inline void * _Nonnull &getOpaquePointerRef(";
+        printer.printBaseName(typeDecl);
+        os << " &object) noexcept { return object._opaquePointer; }\n";
         os << "};\n";
       });
 }
@@ -96,12 +99,16 @@ void ClangClassTypePrinter::printClassTypeReturnScaffold(
 void ClangClassTypePrinter::printParameterCxxtoCUseScaffold(
     raw_ostream &os, const ClassDecl *type, const ModuleDecl *moduleContext,
     llvm::function_ref<void(void)> bodyPrinter, bool isInOut) {
-  // FIXME: Handle isInOut
+  if (isInOut)
+    os << '&';
   ClangSyntaxPrinter(os).printModuleNamespaceQualifiersIfNeeded(
       type->getModuleContext(), moduleContext);
   os << cxx_synthesis::getCxxImplNamespaceName() << "::";
   ClangValueTypePrinter::printCxxImplClassName(os, type);
-  os << "::getOpaquePointer(";
+  os << "::getOpaquePointer";
+  if (isInOut)
+    os << "Ref";
+  os << '(';
   bodyPrinter();
   os << ')';
 }

lib/PrintAsClang/PrintClangFunction.cpp

@@ -151,12 +151,13 @@ class CFunctionSignatureTypePrinter
   void visitClassType(ClassType *CT, Optional<OptionalTypeKind> optionalKind,
                       bool isInOutParam) {
     // FIXME: handle optionalKind.
-    // FIXME: handle isInOutParam.
     if (languageMode != OutputLanguageMode::Cxx) {
       os << "void * _Nonnull";
+      if (isInOutParam)
+        os << " * _Nonnull";
       return;
     }
-    if (typeUseKind == FunctionSignatureTypeUse::ParamType)
+    if (typeUseKind == FunctionSignatureTypeUse::ParamType && !isInOutParam)
       os << "const ";
     ClangSyntaxPrinter(os).printBaseName(CT->getDecl());
     if (typeUseKind == FunctionSignatureTypeUse::ParamType)

test/Interop/SwiftToCxx/class/swift-class-execution.cpp

@@ -50,6 +50,19 @@ int main() {
 // CHECK-NEXT: ClassWithIntField: 0;
 // CHECK-NEXT: ClassWithIntField: 42;
 // CHECK-NEXT: ClassWithIntField: 42;
+// CHECK-NEXT: destroy ClassWithIntField
+
+  {
+    auto x = returnClassWithIntField();
+    assert(getRetainCount(x) == 1);
+    takeClassWithIntFieldInout(x);
+    assert(getRetainCount(x) == 1);
+    takeClassWithIntField(x);
+  }
+// CHECK-NEXT: init ClassWithIntField
+// CHECK-NEXT: init ClassWithIntField
+// CHECK-NEXT: destroy ClassWithIntField
+// CHECK-NEXT: ClassWithIntField: -11;
 // CHECK-NEXT: destroy ClassWithIntField
   return 0;
 }

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

@@ -21,6 +21,7 @@ public final class ClassWithIntField {
 // CHECK: SWIFT_EXTERN void * _Nonnull $s5Class011passThroughA12WithIntFieldyAA0adeF0CADF(void * _Nonnull x) SWIFT_NOEXCEPT SWIFT_CALL; // passThroughClassWithIntField(_:)
 // CHECK-NEXT: SWIFT_EXTERN void * _Nonnull $s5Class06returnA12WithIntFieldAA0acdE0CyF(void) SWIFT_NOEXCEPT SWIFT_CALL; // returnClassWithIntField()
 // CHECK-NEXT: SWIFT_EXTERN void $s5Class04takeA12WithIntFieldyyAA0acdE0CF(void * _Nonnull x) SWIFT_NOEXCEPT SWIFT_CALL; // takeClassWithIntField(_:)
+// CHECK-NEXT: SWIFT_EXTERN void $s5Class04takeA17WithIntFieldInoutyyAA0acdE0CzF(void * _Nonnull * _Nonnull x) SWIFT_NOEXCEPT SWIFT_CALL; // takeClassWithIntFieldInout(_:)
 
 // CHECK: namespace Class {
 
@@ -47,6 +48,7 @@ public final class ClassWithIntField {
 // CHECK-NEXT:public:
 // CHECK-NEXT:static inline ClassWithIntField makeRetained(void * _Nonnull ptr) noexcept { return ClassWithIntField(ptr); }
 // CHECK-NEXT:static inline void * _Nonnull getOpaquePointer(const ClassWithIntField &object) noexcept { return object._opaquePointer; }
+// CHECK-NEXT:static inline void * _Nonnull &getOpaquePointerRef(ClassWithIntField &object) noexcept { return object._opaquePointer; }
 // CHECK-NEXT:};
 // CHECK-EMPTY:
 // CHECK-NEXT:} // namespace _impl
@@ -73,6 +75,11 @@ public func takeClassWithIntField(_ x: ClassWithIntField) {
   print("ClassWithIntField: \(x.field);")
 }
 
+public func takeClassWithIntFieldInout(_ x: inout ClassWithIntField) {
+  x = ClassWithIntField()
+  x.field = -11
+}
+
 // CHECK: inline ClassWithIntField returnClassWithIntField() noexcept SWIFT_WARN_UNUSED_RESULT {
 // CHECK-NEXT:   return _impl::_impl_ClassWithIntField::makeRetained(_impl::$s5Class06returnA12WithIntFieldAA0acdE0CyF());
 // CHECK-NEXT: }