Merge pull request swiftlang#65665 from hyp/eng/function-template-rvalue-ref

[interop] do not import function template with templated rvalue ref

Author: hyp

lib/ClangImporter/ImportType.cpp

@@ -2346,6 +2346,12 @@ ClangImporter::Implementation::importParameterType(
       return None;
   } else if (isa<clang::ReferenceType>(paramTy) &&
              isa<clang::TemplateTypeParmType>(paramTy->getPointeeType())) {
+    // We don't support rvalue reference / universal perfect ref, bail.
+    if (paramTy->isRValueReferenceType()) {
+      addImportDiagnosticFn(Diagnostic(diag::rvalue_ref_params_not_imported));
+      return None;
+    }
+
     auto templateParamType =
         cast<clang::TemplateTypeParmType>(paramTy->getPointeeType());
     swiftParamTy = findGenericTypeInGenericDecls(

test/Interop/Cxx/reference/reference-cannot-import-diagnostic.swift

@@ -1,5 +1,6 @@
 // RUN: rm -rf %t
 // RUN: split-file %s %t
+// RUN: %target-swift-frontend -typecheck -verify -I %t/Inputs  %t/test.swift  -enable-experimental-cxx-interop
 // RUN: not %target-swift-frontend -typecheck -I %t/Inputs  %t/test.swift  -enable-experimental-cxx-interop 2>&1 | %FileCheck %s
 
 //--- Inputs/module.modulemap
@@ -12,13 +13,20 @@ module Test {
 
 void acceptRValueRef(int &&);
 
+template<class T>
+void notStdMove(T &&);
+
 //--- test.swift
 
 import Test
 
 public func test() {
   var x: CInt = 2
-  acceptRValueRef(x)
+  acceptRValueRef(x) // expected-error {{cannot find 'acceptRValueRef' in scope}}
   // CHECK: note: function 'acceptRValueRef' unavailable (cannot import)
   // CHECK: note: C++ functions with rvalue reference parameters are unavailable in Swift
+
+  notStdMove(x) // expected-error {{cannot find 'notStdMove' in scope}}
+  // CHECK: note: function 'notStdMove' unavailable (cannot import)
+  // CHECK: note: C++ functions with rvalue reference parameters are unavailable in Swift
 }

test/Interop/Cxx/templates/function-template-module-interface.swift

@@ -20,7 +20,6 @@
 
 // CHECK: func lvalueReference<T>(_ ref: inout T)
 // CHECK: func constLvalueReference<T>(_: T)
-// CHECK: func forwardingReference<T>(_: inout T)
 // CHECK: func PointerTemplateParameter<T>(_: UnsafeMutablePointer<T>)
 
 // CHECK: enum Orbiters {