[cxx-interop] Implicitly defined move constructors

Author: susmonteiro

lib/ClangImporter/ImportDecl.cpp

@@ -3105,14 +3105,13 @@ namespace {
         // instantiate its copy constructor.
         bool isExplicitlyNonCopyable = hasNonCopyableAttr(decl);
 
-        clang::CXXConstructorDecl *moveCtor = nullptr;
         clang::CXXConstructorDecl *defaultCtor = nullptr;
         if (decl->needsImplicitCopyConstructor() && !isExplicitlyNonCopyable) {
           clangSema.DeclareImplicitCopyConstructor(
               const_cast<clang::CXXRecordDecl *>(decl));
         }
         if (decl->needsImplicitMoveConstructor()) {
-          moveCtor = clangSema.DeclareImplicitMoveConstructor(
+          clangSema.DeclareImplicitMoveConstructor(
               const_cast<clang::CXXRecordDecl *>(decl));
         }
         if (decl->needsImplicitDefaultConstructor()) {
@@ -3129,20 +3128,13 @@ namespace {
                 // Note: we use "doesThisDeclarationHaveABody" here because
                 // that's what "DefineImplicitCopyConstructor" checks.
                 !declCtor->doesThisDeclarationHaveABody()) {
-              if (declCtor->isMoveConstructor()) {
-                if (!moveCtor)
-                  moveCtor = declCtor;
-              } else if (declCtor->isDefaultConstructor()) {
+              if (declCtor->isDefaultConstructor()) {
                 if (!defaultCtor)
                   defaultCtor = declCtor;
               }
             }
           }
         }
-        if (moveCtor && !decl->isAnonymousStructOrUnion()) {
-          clangSema.DefineImplicitMoveConstructor(clang::SourceLocation(),
-                                                  moveCtor);
-        }
         if (defaultCtor) {
           clangSema.DefineImplicitDefaultConstructor(clang::SourceLocation(),
                                                      defaultCtor);
@@ -3151,7 +3143,8 @@ namespace {
         if (decl->needsImplicitDestructor()) {
           auto dtor = clangSema.DeclareImplicitDestructor(
               const_cast<clang::CXXRecordDecl *>(decl));
-          clangSema.DefineImplicitDestructor(clang::SourceLocation(), dtor);
+          if (!dtor->isDeleted() && !dtor->isIneligibleOrNotSelected())
+            clangSema.DefineImplicitDestructor(clang::SourceLocation(), dtor);
         }
       }
 

lib/IRGen/GenStruct.cpp

@@ -625,12 +625,19 @@ namespace {
       if (copyConstructor->isDefaulted() &&
           copyConstructor->getAccess() == clang::AS_public &&
           !copyConstructor->isDeleted() &&
+          !copyConstructor->isIneligibleOrNotSelected() &&
+          !copyConstructor->getParent()->isAnonymousStructOrUnion() &&
           // Note: we use "doesThisDeclarationHaveABody" here because
           // that's what "DefineImplicitCopyConstructor" checks.
           !copyConstructor->doesThisDeclarationHaveABody()) {
-        importer->getClangSema().DefineImplicitCopyConstructor(
-            clang::SourceLocation(),
-            const_cast<clang::CXXConstructorDecl *>(copyConstructor));
+        if (copyConstructor->isCopyConstructor())
+          importer->getClangSema().DefineImplicitCopyConstructor(
+              clang::SourceLocation(),
+              const_cast<clang::CXXConstructorDecl *>(copyConstructor));
+        else
+          importer->getClangSema().DefineImplicitMoveConstructor(
+              clang::SourceLocation(),
+              const_cast<clang::CXXConstructorDecl *>(copyConstructor));
       }
 
       auto &diagEngine = importer->getClangSema().getDiagnostics();

test/Interop/Cxx/stdlib/Inputs/module.modulemap

@@ -99,3 +99,9 @@ module CustomSmartPtr {
   requires cplusplus
   export *
 }
+
+module StdExpected {
+  header "std-expected.h"
+  requires cplusplus
+  export *
+}

test/Interop/Cxx/stdlib/Inputs/std-expected.h

@@ -0,0 +1,23 @@
+#ifndef TEST_INTEROP_CXX_STDLIB_INPUTS_STD_UNIQUE_PTR_H
+#define TEST_INTEROP_CXX_STDLIB_INPUTS_STD_UNIQUE_PTR_H
+
+#include <memory>
+#include <expected>
+
+using NonCopyableExpected = std::expected<std::unique_ptr<bool>, int>;
+
+template<typename T>
+class UniqueRef {
+public:
+  std::unique_ptr<T> _field;
+};
+
+struct Decoder {};
+enum Error {
+  DoomA,
+  DoomB
+};
+
+using DecoderOrError = std::expected<UniqueRef<Decoder>, Error>;
+
+#endif // TEST_INTEROP_CXX_STDLIB_INPUTS_STD_UNIQUE_PTR_H

test/Interop/Cxx/stdlib/use-std-expected-typechecker.swift

@@ -0,0 +1,19 @@
+// RUN: not %target-swift-frontend %s -typecheck -I %S/Inputs -cxx-interoperability-mode=default -Xcc -std=c++23 -diagnostic-style llvm 2>&1 | %FileCheck %s
+
+// TODO Linux CI stdlib doesn't support std::expected yet
+// XFAIL: OS=linux-gnu
+
+import StdExpected
+import CxxStdlib
+
+func takeCopyable<T: Copyable>(_ x: T) {} 
+
+let nonCopExpected = NonCopyableExpected()
+takeCopyable(nonCopExpected)
+// CHECK: error: global function 'takeCopyable' requires that 'NonCopyableExpected' (aka {{.*}}) conform to 'Copyable'
+
+let doe = DecoderOrError()
+takeCopyable(doe)
+// CHECK: error: global function 'takeCopyable' requires that 'DecoderOrError' (aka {{.*}}) conform to 'Copyable'
+
+// CHECK-NOT: error