Merge pull request #69746 from apple/egorzhdan/avoid-rvalue-this-inheritance

[cxx-interop] Do not import inherited methods with rvalue this

Author: egorzhdan

lib/ClangImporter/ClangImporter.cpp

@@ -5481,6 +5481,13 @@ cloneBaseMemberDecl(ValueDecl *decl, DeclContext *newContext) {
         (fn->getClangDecl() &&
          isa<clang::FunctionTemplateDecl>(fn->getClangDecl())))
       return nullptr;
+    if (auto cxxMethod =
+            dyn_cast_or_null<clang::CXXMethodDecl>(fn->getClangDecl())) {
+      // FIXME: if this function has rvalue this, we won't be able to synthesize
+      // the accessor correctly (https://github.com/apple/swift/issues/69745).
+      if (cxxMethod->getRefQualifier() == clang::RefQualifierKind::RQ_RValue)
+        return nullptr;
+    }
 
     ASTContext &context = decl->getASTContext();
     auto out = FuncDecl::createImplicit(

test/Interop/Cxx/class/inheritance/Inputs/functions.h

@@ -22,6 +22,10 @@ struct Base {
       __attribute__((swift_attr("import_unsafe"))) {
     return "Base::constInBase";
   }
+  inline const char *rvalueThisInBase() const&&
+      __attribute__((swift_attr("import_unsafe"))) {
+    return "Base::rvalueThisInBase";
+  }
   // TODO: if these are unnamed we hit an (unrelated) SILGen bug. Same for
   // subscripts.
   inline const char *takesArgsInBase(int a, int b, int c) const

test/Interop/Cxx/class/inheritance/functions-module-interface.swift

@@ -15,6 +15,8 @@
 // CHECK-NEXT:   @discardableResult
 // CHECK-NEXT:   func constInBase() -> UnsafePointer<CChar>!
 // CHECK-NEXT:   @discardableResult
+// CHECK-NEXT:   func rvalueThisInBase() -> UnsafePointer<CChar>!
+// CHECK-NEXT:   @discardableResult
 // CHECK-NEXT:   func takesArgsInBase(_ a: Int32, _ b: Int32, _ c: Int32) -> UnsafePointer<CChar>!
 // CHECK-NEXT:   @discardableResult
 // CHECK-NEXT:   func takesNonTrivialInBase(_ a: NonTrivial) -> UnsafePointer<CChar>!

test/Interop/Cxx/class/inheritance/functions-typechecker.swift

@@ -17,3 +17,6 @@ Derived().sameMethodNameSameSignature()
 Derived().sameMethodDifferentSignature(1)
 // ok, this is the base class method.
 Derived().sameMethodDifferentSignature()
+
+// FIXME: we should import this (https://github.com/apple/swift/issues/69745):
+Derived().rvalueThisInBase() // expected-error {{value of type 'Derived' has no member 'rvalueThisInBase'}}