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Merge pull request #416 from madsmtm/mainthreadmarker-in-extern-methods
Allow using `MainThreadMarker` in `extern_methods!`
2 parents 282188d + 962e7a5 commit ce6100c

8 files changed

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-0
lines changed

‎crates/objc2/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
66

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## Unreleased - YYYY-MM-DD
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### Added
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* Allow using `MainThreadMarker` in `extern_methods!`.
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### Changed
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* Renamed `runtime` types:
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- `Object` to `AnyObject`.

‎crates/objc2/src/macros/__method_msg_send.rs

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@@ -22,6 +22,30 @@ macro_rules! __method_msg_send {
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}
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};
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// Skip using `MainThreadMarker` in the message send.
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//
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// This is a purely textual match, and using e.g.
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// `Foundation::MainThreadMarker` would fail - but that would just be
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// detected as giving a wrong number of arguments, so it's fine for now.
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(
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($receiver:expr)
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($($sel_rest:tt)*)
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($arg:ident: MainThreadMarker $(, $($args_rest:tt)*)?)
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($($sel_parsed:tt)*)
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($($arg_parsed:tt)*)
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) => ({
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let _ = $arg;
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$crate::__method_msg_send! {
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($receiver)
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($($sel_rest)*)
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($($($args_rest)*)?)
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($($sel_parsed)*)
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($($arg_parsed)*)
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}
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});
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// Parse each argument-selector pair
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(
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($receiver:expr)
@@ -173,6 +197,32 @@ macro_rules! __method_msg_send_id {
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}
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};
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// Skip using `MainThreadMarker` in the message send.
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//
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// This is a purely textual match, and using e.g.
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// `Foundation::MainThreadMarker` would fail - but that would just be
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// detected as giving a wrong number of arguments, so it's fine for now.
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(
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($receiver:expr)
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($($sel_rest:tt)*)
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($arg:ident: MainThreadMarker $(, $($args_rest:tt)*)?)
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($($sel_parsed:tt)*)
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($($arg_parsed:tt)*)
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($($retain_semantics:ident)?)
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) => ({
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let _ = $arg;
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$crate::__method_msg_send_id! {
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($receiver)
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($($sel_rest)*)
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($($($args_rest)*)?)
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($($sel_parsed)*)
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($($arg_parsed)*)
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($($retain_semantics)?)
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}
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});
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// Parse each argument-selector pair
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(
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($receiver:expr)

‎crates/objc2/src/macros/extern_methods.rs

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@@ -26,6 +26,12 @@
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/// [`Result`]. See the error section in [`msg_send!`] and [`msg_send_id!`]
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/// for details.
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///
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/// If you use `icrate::Foundation::MainThreadMarker` as a parameter type, the
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/// macro will ignore it, allowing you to neatly specify "this method must be
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/// run on the main thread". Note that due to type-system limitations, this is
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/// currently a textual match on `MainThreadMarker`; so you must use that
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/// exact identifier.
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///
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/// Putting other attributes on the method such as `cfg`, `allow`, `doc`,
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/// `deprecated` and so on is supported. However, note that `cfg_attr` may not
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/// work correctly, due to implementation difficulty - if you have a concrete

‎crates/objc2/tests/macros_mainthreadmarker.rs

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@@ -0,0 +1,79 @@
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use objc2::rc::Id;
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use objc2::runtime::{NSObject, NSObjectProtocol};
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use objc2::{declare_class, extern_methods, extern_protocol, mutability, ClassType, ProtocolType};
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extern_protocol!(
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#[allow(clippy::missing_safety_doc)]
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unsafe trait Proto: NSObjectProtocol {
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#[method(myMethod:)]
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fn protocol_method(mtm: MainThreadMarker, arg: i32) -> i32;
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#[method_id(myMethodId:)]
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fn protocol_method_id(mtm: MainThreadMarker, arg: &Self) -> Id<Self>;
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}
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unsafe impl ProtocolType for dyn Proto {
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const NAME: &'static str = "MainThreadMarkerTestProtocol";
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}
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);
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declare_class!(
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#[derive(PartialEq, Eq, Hash, Debug)]
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struct Cls;
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unsafe impl ClassType for Cls {
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type Super = NSObject;
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type Mutability = mutability::InteriorMutable;
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const NAME: &'static str = "MainThreadMarkerTest";
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}
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unsafe impl Proto for Cls {
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#[method(myMethod:)]
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fn _my_mainthreadonly_method(arg: i32) -> i32 {
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arg + 1
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}
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#[method_id(myMethodId:)]
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fn _my_mainthreadonly_method_id(arg: &Self) -> Id<Self> {
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unsafe { Id::retain(arg as *const Self as *mut Self).unwrap() }
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}
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}
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);
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unsafe impl NSObjectProtocol for Cls {}
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// The macro does a textual match; but when users actually use
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// `icrate::Foundation::MainThreadMarker` to ensure soundness, they will not
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// do this!
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#[derive(Clone, Copy)]
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struct MainThreadMarker(bool);
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extern_methods!(
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unsafe impl Cls {
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#[method_id(new)]
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fn new() -> Id<Self>;
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#[method(myMethod:)]
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fn method(mtm: MainThreadMarker, arg: i32, mtm2: MainThreadMarker) -> i32;
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#[method_id(myMethodId:)]
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fn method_id(mtm: MainThreadMarker, arg: &Self, mtm2: MainThreadMarker) -> Id<Self>;
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}
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);
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#[test]
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fn call() {
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let obj1 = Cls::new();
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let mtm = MainThreadMarker(true);
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let res = Cls::method(mtm, 2, mtm);
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assert_eq!(res, 3);
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let res = Cls::protocol_method(mtm, 3);
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assert_eq!(res, 4);
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let obj2 = Cls::method_id(mtm, &obj1, mtm);
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assert_eq!(obj1, obj2);
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let obj2 = Cls::protocol_method_id(mtm, &obj1);
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assert_eq!(obj1, obj2);
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}

‎crates/test-ui/ui/extern_methods_invalid_type.rs

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@@ -1,3 +1,4 @@
1+
use icrate::Foundation::MainThreadMarker;
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use objc2::rc::Id;
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use objc2::runtime::NSObject;
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use objc2::{extern_class, extern_methods, mutability, ClassType};
@@ -46,4 +47,11 @@ extern_methods!(
4647
}
4748
);
4849

50+
extern_methods!(
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unsafe impl MyObject {
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#[method(mainThreadMarkerAsReturn)]
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fn main_thread_marker_as_return() -> MainThreadMarker;
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}
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);
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4957
fn main() {}

‎crates/test-ui/ui/extern_methods_invalid_type.stderr

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@@ -132,3 +132,36 @@ note: required by a bound in `send_message_id`
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| unsafe fn send_message_id<A: MessageArguments, R: MaybeUnwrap<Input = U>>(
133133
| ^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `MsgSendId::send_message_id`
134134
= note: this error originates in the macro `$crate::__msg_send_id_helper` which comes from the expansion of the macro `extern_methods` (in Nightly builds, run with -Z macro-backtrace for more info)
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error[E0277]: the trait bound `MainThreadMarker: Encode` is not satisfied
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--> ui/extern_methods_invalid_type.rs
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|
139+
| / extern_methods!(
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| | unsafe impl MyObject {
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| | #[method(mainThreadMarkerAsReturn)]
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| | fn main_thread_marker_as_return() -> MainThreadMarker;
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| | }
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| | );
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| |_^ the trait `Encode` is not implemented for `MainThreadMarker`
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|
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= help: the following other types implement trait `Encode`:
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&'a T
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&'a mut T
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*const T
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*const c_void
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*mut T
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*mut c_void
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AtomicI16
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AtomicI32
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and $N others
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= note: required for `MainThreadMarker` to implement `EncodeReturn`
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= note: required for `MainThreadMarker` to implement `EncodeConvertReturn`
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note: required by a bound in `send_message`
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--> $WORKSPACE/crates/objc2/src/message/mod.rs
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|
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| unsafe fn send_message<A, R>(self, sel: Sel, args: A) -> R
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| ------------ required by a bound in this associated function
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...
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| R: EncodeConvertReturn,
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| ^^^^^^^^^^^^^^^^^^^ required by this bound in `MessageReceiver::send_message`
167+
= note: this error originates in the macro `$crate::__msg_send_helper` which comes from the expansion of the macro `extern_methods` (in Nightly builds, run with -Z macro-backtrace for more info)

‎crates/test-ui/ui/extern_methods_wrong_arguments_error.rs

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@@ -1,3 +1,4 @@
1+
use icrate::Foundation::MainThreadMarker;
12
use objc2::rc::Id;
23
use objc2::runtime::NSObject;
34
use objc2::{extern_class, extern_methods, mutability, ClassType};
@@ -39,4 +40,11 @@ extern_methods!(
3940
}
4041
);
4142

43+
extern_methods!(
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unsafe impl MyObject {
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#[method(tooFew:withMtm:_)]
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fn too_few_with_mtm(&self, mtm: MainThreadMarker) -> Result<(), Id<NSObject>>;
47+
}
48+
);
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4250
fn main() {}

‎crates/test-ui/ui/extern_methods_wrong_arguments_error.stderr

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Original file line numberDiff line numberDiff line change
@@ -49,3 +49,16 @@ error: number of arguments in function and selector did not match
4949
| |_^
5050
|
5151
= note: this error originates in the macro `$crate::__method_msg_send` which comes from the expansion of the macro `extern_methods` (in Nightly builds, run with -Z macro-backtrace for more info)
52+
53+
error: number of arguments in function and selector did not match
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--> ui/extern_methods_wrong_arguments_error.rs
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|
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| / extern_methods!(
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| | unsafe impl MyObject {
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| | #[method(tooFew:withMtm:_)]
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| | fn too_few_with_mtm(&self, mtm: MainThreadMarker) -> Result<(), Id<NSObject>>;
60+
| | }
61+
| | );
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| |_^
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|
64+
= note: this error originates in the macro `$crate::__method_msg_send` which comes from the expansion of the macro `extern_methods` (in Nightly builds, run with -Z macro-backtrace for more info)

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