Support tuples from Swift -> Rust (#211)

Author: NiwakaDev

SwiftRustIntegrationTestRunner/SwiftRustIntegrationTestRunner/Tuple.swift

@@ -10,3 +10,11 @@ import Foundation
 func swift_reflect_tuple_primitives(arg: (Int32, UInt32)) -> (Int32, UInt32) {
     arg
 }
+
+func swift_reflect_opaque_and_primitive_tuple(arg: (TupleTestOpaqueRustType, Int32)) -> (TupleTestOpaqueRustType, Int32) {
+    arg
+}
+
+func swift_reflect_struct_and_enum_and_string(arg: (TupleTestStruct, TupleTestEnum, RustString)) -> (TupleTestStruct, TupleTestEnum, RustString) {
+    arg
+}

crates/swift-bridge-ir/src/bridged_type.rs

@@ -1864,7 +1864,7 @@ impl BridgedType {
             },
             BridgedType::Foreign(ty) => match ty {
                 CustomBridgedType::Shared(ty) => match ty {
-                    SharedType::Struct(_ty) => todo!(),
+                    SharedType::Struct(ty) => ty.name.to_string(),
                     SharedType::Enum(ty) => ty.name.to_string(),
                 },
             },

crates/swift-bridge-ir/src/bridged_type/bridged_opaque_type.rs

@@ -315,7 +315,10 @@ impl BridgeableType for OpaqueForeignType {
                                 expression, expression
                             )
                         } else {
-                            todo!()
+                            format!(
+                                "{{{}.isOwned = false; return {}.ptr;}}()",
+                                expression, expression
+                            )
                         }
                     }
                     TypePosition::SharedStructField => {

crates/swift-bridge-ir/src/codegen/codegen_tests/built_in_tuple_codegen_tests.rs

@@ -341,3 +341,151 @@ func __swift_bridge__some_function (_ arg: __swift_bridge__$tuple$I32U8) -> __sw
         .test();
     }
 }
+
+/// Verify that we can use a (opaque type, String) as Swift function arg and return type.
+mod extern_swift_tuple_opaque_and_string {
+    use super::*;
+
+    fn bridge_module_tokens() -> TokenStream {
+        quote! {
+            #[swift_bridge::bridge]
+            mod ffi {
+                extern "Rust" {
+                    type SomeType;
+                }
+                extern "Swift" {
+                    fn some_function(arg: (SomeType, String)) -> (SomeType, String);
+                }
+            }
+        }
+    }
+
+    fn expected_rust_tokens() -> ExpectedRustTokens {
+        ExpectedRustTokens::ContainsMany(vec![
+            quote! {
+                pub fn some_function (arg: (super::SomeType, String)) -> (super::SomeType, String) {
+                    {
+                        let val = unsafe { __swift_bridge__some_function ({ let val = arg ; __swift_bridge__tuple_SomeTypeString (Box::into_raw(Box::new({
+                            let val: super::SomeType = val.0;
+                            val
+                        })) as *mut super::SomeType , swift_bridge::string::RustString(val.1).box_into_raw()) }) };
+                        (unsafe { * Box::from_raw(val.0) }, unsafe { Box::from_raw(val.1).0 })
+                    }
+                }
+            },
+            quote! {
+                #[link_name = "__swift_bridge__$some_function"]
+                fn __swift_bridge__some_function(arg: __swift_bridge__tuple_SomeTypeString) -> __swift_bridge__tuple_SomeTypeString;
+            },
+            quote! {
+                #[repr(C)]
+                #[doc(hidden)]
+                pub struct __swift_bridge__tuple_SomeTypeString(*mut super::SomeType, *mut swift_bridge::string::RustString);
+            },
+        ])
+    }
+
+    fn expected_swift_code() -> ExpectedSwiftCode {
+        ExpectedSwiftCode::ContainsManyAfterTrim(vec![
+            r#"
+@_cdecl("__swift_bridge__$some_function")
+func __swift_bridge__some_function (_ arg: __swift_bridge__$tuple$SomeTypeString) -> __swift_bridge__$tuple$SomeTypeString {
+    { let val = some_function(arg: { let val = arg; return (SomeType(ptr: val._0), RustString(ptr: val._1)); }()); return __swift_bridge__$tuple$SomeTypeString(_0: {val.0.isOwned = false; return val.0.ptr;}(), _1: { let rustString = val.1.intoRustString(); rustString.isOwned = false; return rustString.ptr }()); }()
+}
+"#,
+        ])
+    }
+
+    fn expected_c_header() -> ExpectedCHeader {
+        ExpectedCHeader::ContainsManyAfterTrim(vec![
+            r#"typedef struct __swift_bridge__$tuple$SomeTypeString { void* _0; void* _1; } __swift_bridge__$tuple$SomeTypeString;
+"#,
+        ])
+    }
+
+    #[test]
+    fn extern_swift_tuple_opaque_and_string() {
+        CodegenTest {
+            bridge_module: bridge_module_tokens().into(),
+            expected_rust_tokens: expected_rust_tokens(),
+            expected_swift_code: expected_swift_code(),
+            expected_c_header: expected_c_header(),
+        }
+        .test();
+    }
+}
+
+/// Verify that we can use a (transparent struct type, transparent enum type) as Swift function arg and return type.
+mod extern_swift_tuple_transparent_struct_and_transparent_enum {
+    use super::*;
+
+    fn bridge_module_tokens() -> TokenStream {
+        quote! {
+            #[swift_bridge::bridge]
+            mod ffi {
+                enum SomeEnum {
+                    Variant1,
+                    Variant2,
+                }
+                #[swift_bridge(swift_repr = "struct")]
+                struct SomeStruct {
+                    field: u8
+                }
+                extern "Swift" {
+                    fn some_function(arg: (SomeStruct, SomeEnum)) -> (SomeStruct, SomeEnum);
+                }
+            }
+        }
+    }
+
+    fn expected_rust_tokens() -> ExpectedRustTokens {
+        ExpectedRustTokens::ContainsMany(vec![
+            quote! {
+                pub fn some_function (arg: (SomeStruct, SomeEnum)) -> (SomeStruct, SomeEnum) {
+                    {
+                        let val = unsafe { __swift_bridge__some_function ({ let val = arg ; __swift_bridge__tuple_SomeStructSomeEnum (val.0.into_ffi_repr(), val.1.into_ffi_repr()) }) };
+                        (val.0.into_rust_repr(), val.1.into_rust_repr())
+                    }
+                }
+            },
+            quote! {
+                #[link_name = "__swift_bridge__$some_function"]
+                fn __swift_bridge__some_function(arg: __swift_bridge__tuple_SomeStructSomeEnum) -> __swift_bridge__tuple_SomeStructSomeEnum;
+            },
+            quote! {
+                #[repr(C)]
+                #[doc(hidden)]
+                pub struct __swift_bridge__tuple_SomeStructSomeEnum(__swift_bridge__SomeStruct, __swift_bridge__SomeEnum);
+            },
+        ])
+    }
+
+    fn expected_swift_code() -> ExpectedSwiftCode {
+        ExpectedSwiftCode::ContainsManyAfterTrim(vec![
+            r#"
+@_cdecl("__swift_bridge__$some_function")
+func __swift_bridge__some_function (_ arg: __swift_bridge__$tuple$SomeStructSomeEnum) -> __swift_bridge__$tuple$SomeStructSomeEnum {
+    { let val = some_function(arg: { let val = arg; return (val._0.intoSwiftRepr(), val._1.intoSwiftRepr()); }()); return __swift_bridge__$tuple$SomeStructSomeEnum(_0: val.0.intoFfiRepr(), _1: val.1.intoFfiRepr()); }()
+}
+"#,
+        ])
+    }
+
+    fn expected_c_header() -> ExpectedCHeader {
+        ExpectedCHeader::ContainsManyAfterTrim(vec![
+            r#"typedef struct __swift_bridge__$tuple$SomeStructSomeEnum { struct __swift_bridge__$SomeStruct _0; struct __swift_bridge__$SomeEnum _1; } __swift_bridge__$tuple$SomeStructSomeEnum;
+"#,
+        ])
+    }
+
+    #[test]
+    fn extern_swift_tuple_transparent_struct_and_transparent_enum() {
+        CodegenTest {
+            bridge_module: bridge_module_tokens().into(),
+            expected_rust_tokens: expected_rust_tokens(),
+            expected_swift_code: expected_swift_code(),
+            expected_c_header: expected_c_header(),
+        }
+        .test();
+    }
+}

crates/swift-integration-tests/src/tuple.rs

@@ -1,5 +1,14 @@
 #[swift_bridge::bridge]
 mod ffi {
+    enum TupleTestEnum {
+        NamedField { data: i32 },
+        UnnamedFields(u8, String),
+        NoFields,
+    }
+    #[swift_bridge(swift_repr = "struct")]
+    struct TupleTestStruct {
+        field: u8,
+    }
     extern "Rust" {
         type TupleTestOpaqueRustType;
         #[swift_bridge(init)]
@@ -15,6 +24,12 @@ mod ffi {
     }
     extern "Swift" {
         fn swift_reflect_tuple_primitives(arg: (i32, u32)) -> (i32, u32);
+        fn swift_reflect_opaque_and_primitive_tuple(
+            arg: (TupleTestOpaqueRustType, i32),
+        ) -> (TupleTestOpaqueRustType, i32);
+        fn swift_reflect_struct_and_enum_and_string(
+            arg: (TupleTestStruct, TupleTestEnum, String),
+        ) -> (TupleTestStruct, TupleTestEnum, String);
     }
     extern "Rust" {
         fn test_rust_calls_swift_tuples();
@@ -50,4 +65,20 @@ fn test_rust_calls_swift_tuples() {
     let val = ffi::swift_reflect_tuple_primitives((-123, 123));
     assert_eq!(val.0, -123);
     assert_eq!(val.1, 123);
+
+    let val = ffi::swift_reflect_opaque_and_primitive_tuple((TupleTestOpaqueRustType(123), -123));
+    assert_eq!(val.0 .0, 123);
+    assert_eq!(val.1, -123);
+
+    let val = ffi::swift_reflect_struct_and_enum_and_string((
+        ffi::TupleTestStruct { field: 123 },
+        ffi::TupleTestEnum::NamedField { data: -123 },
+        "hello, world".to_string(),
+    ));
+    assert_eq!(val.0.field, 123);
+    assert!(matches!(
+        val.1,
+        ffi::TupleTestEnum::NamedField { data: -123 }
+    ));
+    assert_eq!(val.2, "hello, world".to_string());
 }