mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
4f5c75a236
This PR makes it possible to instantiate C++ class templates from Swift. Given a C++ header:
```c++
// C++ module `ClassTemplates`
template<class T>
struct MagicWrapper {
T t;
};
struct MagicNumber {};
```
it is now possible to write in Swift:
```swift
import ClassTemplates
func x() -> MagicWrapper<MagicNumber> {
return MagicWrapper<MagicNumber>()
}
```
This is achieved by importing C++ class templates as generic structs, and then when Swift type checker calls `applyGenericArguments` we detect when the generic struct is backed by the C++ class template and call Clang to instantiate the template. In order to make it possible to put class instantiations such as `MagicWrapper<MagicNumber>` into Swift signatures, we have created a new field in `StructDecl` named `TemplateInstantiationType` where the typechecker stores the `BoundGenericType` which we serialize. Deserializer then notices that the `BoundGenericType` is actually a C++ class template and performs the instantiation logic.
Depends on https://github.com/apple/swift/pull/33420.
Progress towards https://bugs.swift.org/browse/SR-13261.
Fixes https://bugs.swift.org/browse/SR-13775.
Co-authored-by: Dmitri Gribenko <gribozavr@gmail.com>
Co-authored-by: Rosica Dejanovska <rosica@google.com>
12 lines
810 B
Swift
12 lines
810 B
Swift
// RUN: %empty-directory(%t)
|
|
// RUN: %target-swiftxx-frontend -emit-module -o %t/SwiftClassTemplateInNamespaceModule.swiftmodule %S/Inputs/SwiftClassTemplateInNamespaceModule.swift -I %S/Inputs -enable-library-evolution -swift-version 5
|
|
// RUN: %target-swift-ide-test -print-module -module-to-print=SwiftClassTemplateInNamespaceModule -I %t/ -source-filename=x -enable-cxx-interop | %FileCheck %s
|
|
|
|
// CHECK: import ClassTemplateInNamespaceForSwiftModule
|
|
// CHECK: func receiveShip(_ i: inout Space.__CxxTemplateInstN5Space4ShipIbEE)
|
|
// CHECK: func receiveShipWithEngine(_ i: inout Space.__CxxTemplateInstN5Space4ShipIN6Engine8TurbojetEEE)
|
|
|
|
// CHECK: func returnShip() -> Space.__CxxTemplateInstN5Space4ShipIbEE
|
|
// CHECK: func returnShipWithEngine() -> Space.__CxxTemplateInstN5Space4ShipIN6Engine8TurbojetEEE
|
|
|