oden/third-party/vendor/objc2/src/message/mod.rs
2024-03-08 11:03:01 -08:00

543 lines
16 KiB
Rust

use core::mem;
use core::mem::ManuallyDrop;
use core::ptr::NonNull;
use crate::encode::{Encode, EncodeArguments, EncodeConvert, RefEncode};
use crate::rc::{Id, Owned, Ownership};
use crate::runtime::{Class, Imp, Object, Sel};
use crate::ClassType;
#[cfg(feature = "catch-all")]
#[track_caller]
unsafe fn conditional_try<R: EncodeConvert>(f: impl FnOnce() -> R) -> R {
let f = core::panic::AssertUnwindSafe(f);
match unsafe { crate::exception::catch(f) } {
Ok(r) => r,
Err(exception) => {
if let Some(exception) = exception {
panic!("uncaught {:?}", exception)
} else {
panic!("uncaught exception nil")
}
}
}
}
#[cfg(not(feature = "catch-all"))]
#[inline]
#[track_caller]
unsafe fn conditional_try<R: EncodeConvert>(f: impl FnOnce() -> R) -> R {
f()
}
#[cfg(feature = "verify_message")]
#[track_caller]
fn panic_verify(cls: &Class, sel: Sel, err: crate::VerificationError) -> ! {
panic!(
"invalid message send to {}[{:?} {:?}]: {}",
if cls.is_metaclass() { "+" } else { "-" },
cls,
sel,
err
)
}
#[cfg(feature = "apple")]
#[path = "apple/mod.rs"]
mod platform;
#[cfg(feature = "gnustep-1-7")]
#[path = "gnustep.rs"]
mod platform;
use self::platform::{send_super_unverified, send_unverified};
/// Types that can be sent Objective-C messages.
///
/// Implementing this provides [`MessageReceiver`] implementations for common
/// pointer types and references to the type, which allows using them as the
/// receiver (first argument) in the [`msg_send!`][`crate::msg_send`] macro.
///
/// This trait also allows the object to be used in [`rc::Id`][`Id`].
///
/// This is a subtrait of [`RefEncode`], meaning the type must also implement
/// that, almost always as [`Encoding::Object`].
///
/// [`Encoding::Object`]: crate::Encoding::Object
///
///
/// # Safety
///
/// The type must represent an Objective-C object, meaning it:
/// - Must be valid to reinterpret as [`runtime::Object`][`Object`].
/// - Must be able to be the receiver of an Objective-C message sent with
/// [`objc_msgSend`] or similar.
/// - Must respond to the standard memory management `retain`, `release` and
/// `autorelease` messages.
///
/// [`objc_msgSend`]: https://developer.apple.com/documentation/objectivec/1456712-objc_msgsend
///
///
/// # Example
///
/// ```
/// use objc2::runtime::Object;
/// use objc2::{Encoding, Message, RefEncode};
///
/// #[repr(C)]
/// struct MyObject {
/// // This has the exact same layout as `Object`
/// inner: Object
/// }
///
/// unsafe impl RefEncode for MyObject {
/// const ENCODING_REF: Encoding = Encoding::Object;
/// }
///
/// unsafe impl Message for MyObject {}
///
/// // `*mut MyObject` and other pointer/reference types to the object can
/// // now be used in `msg_send!`
/// //
/// // And `Id<MyObject, O>` can now be constructed.
/// ```
pub unsafe trait Message: RefEncode {}
unsafe impl Message for Object {}
// TODO: Make this fully private
pub(crate) mod private {
use super::*;
pub trait Sealed {}
impl<T: Message + ?Sized> Sealed for *const T {}
impl<T: Message + ?Sized> Sealed for *mut T {}
impl<T: Message + ?Sized> Sealed for NonNull<T> {}
impl<'a, T: Message + ?Sized> Sealed for &'a T {}
impl<'a, T: Message + ?Sized> Sealed for &'a mut T {}
impl<'a, T: Message + ?Sized, O: Ownership> Sealed for &'a Id<T, O> {}
impl<'a, T: Message + ?Sized> Sealed for &'a mut Id<T, Owned> {}
impl<T: Message + ?Sized, O: Ownership> Sealed for ManuallyDrop<Id<T, O>> {}
impl Sealed for *const Class {}
impl<'a> Sealed for &'a Class {}
}
/// Types that can directly be used as the receiver of Objective-C messages.
///
/// Examples include objects, classes, and blocks.
///
/// This is a sealed trait (for now) that is automatically implemented for
/// pointers to types implementing [`Message`], so that code can be generic
/// over the message receiver.
///
/// This is mostly an implementation detail; you'll want to implement
/// [`Message`] for your type instead.
///
///
/// # Safety
///
/// This is a sealed trait, and should not need to be implemented. Open an
/// issue if you know a use-case where this restrition should be lifted!
pub unsafe trait MessageReceiver: private::Sealed + Sized {
#[doc(hidden)]
type __Inner: ?Sized;
#[doc(hidden)]
fn __as_raw_receiver(self) -> *mut Object;
/// Sends a message to self with the given selector and arguments.
///
/// The correct version of `objc_msgSend` will be chosen based on the
/// return type. For more information, see the section on "Sending
/// Messages" in Apple's [documentation][runtime].
///
/// If the selector is known at compile-time, it is recommended to use the
/// [`msg_send!`] macro rather than this method.
///
/// [runtime]: https://developer.apple.com/documentation/objectivec/objective-c_runtime?language=objc
///
///
/// # Safety
///
/// This shares the same safety requirements as [`msg_send!`].
///
/// The added invariant is that the selector must take the same number of
/// arguments as is given.
///
/// [`msg_send!`]: crate::msg_send
#[inline]
#[track_caller]
unsafe fn send_message<A, R>(self, sel: Sel, args: A) -> R
where
A: MessageArguments,
R: EncodeConvert,
{
let this = self.__as_raw_receiver();
// TODO: Always enable this when `debug_assertions` are on.
#[cfg(feature = "verify_message")]
{
// SAFETY: Caller ensures only valid or NULL pointers.
let this = unsafe { this.as_ref() };
let cls = if let Some(this) = this {
this.class()
} else {
panic!("messsaging {:?} to nil", sel);
};
if let Err(err) = cls.verify_sel::<A, R>(sel) {
panic_verify(cls, sel, err);
}
}
unsafe { EncodeConvert::__from_inner(send_unverified(this, sel, args)) }
}
/// Sends a message to a specific superclass with the given selector and
/// arguments.
///
/// The correct version of `objc_msgSend_super` will be chosen based on the
/// return type. For more information, see the section on "Sending
/// Messages" in Apple's [documentation][runtime].
///
/// If the selector is known at compile-time, it is recommended to use the
/// [`msg_send!(super(...), ...)`] macro rather than this method.
///
/// [runtime]: https://developer.apple.com/documentation/objectivec/objective-c_runtime?language=objc
///
///
/// # Safety
///
/// This shares the same safety requirements as
/// [`msg_send!(super(...), ...)`].
///
/// The added invariant is that the selector must take the same number of
/// arguments as is given.
///
/// [`msg_send!(super(...), ...)`]: crate::msg_send
#[inline]
#[track_caller]
unsafe fn send_super_message<A, R>(self, superclass: &Class, sel: Sel, args: A) -> R
where
A: MessageArguments,
R: EncodeConvert,
{
let this = self.__as_raw_receiver();
#[cfg(feature = "verify_message")]
{
if this.is_null() {
panic!("messsaging {:?} to nil", sel);
}
if let Err(err) = superclass.verify_sel::<A, R>(sel) {
panic_verify(superclass, sel, err);
}
}
unsafe { EncodeConvert::__from_inner(send_super_unverified(this, superclass, sel, args)) }
}
#[inline]
#[track_caller]
#[doc(hidden)]
unsafe fn __send_super_message_static<A, R>(self, sel: Sel, args: A) -> R
where
Self::__Inner: ClassType,
<Self::__Inner as ClassType>::Super: ClassType,
A: MessageArguments,
R: EncodeConvert,
{
unsafe { self.send_super_message(<Self::__Inner as ClassType>::Super::class(), sel, args) }
}
}
// Note that we implement MessageReceiver for unsized types as well, this is
// to support `extern type`s in the future, not because we want to allow DSTs.
unsafe impl<T: Message + ?Sized> MessageReceiver for *const T {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
(self as *mut T).cast()
}
}
unsafe impl<T: Message + ?Sized> MessageReceiver for *mut T {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
self.cast()
}
}
unsafe impl<T: Message + ?Sized> MessageReceiver for NonNull<T> {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
self.as_ptr().cast()
}
}
unsafe impl<'a, T: Message + ?Sized> MessageReceiver for &'a T {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
let ptr: *const T = self;
(ptr as *mut T).cast()
}
}
unsafe impl<'a, T: Message + ?Sized> MessageReceiver for &'a mut T {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
let ptr: *mut T = self;
ptr.cast()
}
}
unsafe impl<'a, T: Message + ?Sized, O: Ownership> MessageReceiver for &'a Id<T, O> {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
(Id::as_ptr(self) as *mut T).cast()
}
}
unsafe impl<'a, T: Message + ?Sized> MessageReceiver for &'a mut Id<T, Owned> {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
Id::as_mut_ptr(self).cast()
}
}
unsafe impl<T: Message + ?Sized, O: Ownership> MessageReceiver for ManuallyDrop<Id<T, O>> {
type __Inner = T;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
Id::consume_as_ptr(self).cast()
}
}
unsafe impl MessageReceiver for *const Class {
type __Inner = Class;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
(self as *mut Class).cast()
}
}
unsafe impl<'a> MessageReceiver for &'a Class {
type __Inner = Class;
#[inline]
fn __as_raw_receiver(self) -> *mut Object {
let ptr: *const Class = self;
(ptr as *mut Class).cast()
}
}
/// Types that may be used as the arguments of an Objective-C message.
///
/// This is implemented for tuples of up to 12 arguments, where each argument
/// implements [`Encode`][crate::Encode] (or can be converted from one).
///
///
/// # Safety
///
/// This is a sealed trait, and should not need to be implemented. Open an
/// issue if you know a use-case where this restrition should be lifted!
pub unsafe trait MessageArguments: EncodeArguments {
/// Invoke an [`Imp`] with the given object, selector, and arguments.
///
/// This method is the primitive used when sending messages and should not
/// be called directly; instead, use the `msg_send!` macro or, in cases
/// with a dynamic selector, the [`MessageReceiver::send_message`] method.
#[doc(hidden)]
unsafe fn __invoke<R: Encode>(imp: Imp, obj: *mut Object, sel: Sel, args: Self) -> R;
}
macro_rules! message_args_impl {
($($a:ident: $t:ident),*) => (
unsafe impl<$($t: EncodeConvert),*> MessageArguments for ($($t,)*) {
#[inline]
unsafe fn __invoke<R: Encode>(imp: Imp, obj: *mut Object, sel: Sel, ($($a,)*): Self) -> R {
// The imp must be cast to the appropriate function pointer
// type before being called; the msgSend functions are not
// parametric, but instead "trampolines" to the actual
// method implementations.
#[cfg(not(feature = "unstable-c-unwind"))]
let imp: unsafe extern "C" fn(*mut Object, Sel $(, $t::__Inner)*) -> R = unsafe {
mem::transmute(imp)
};
#[cfg(feature = "unstable-c-unwind")]
let imp: unsafe extern "C-unwind" fn(*mut Object, Sel $(, $t::__Inner)*) -> R = unsafe {
mem::transmute(imp)
};
// TODO: On x86_64 it would be more efficient to use a GOT
// entry here (e.g. adding `nonlazybind` in LLVM).
// Same can be said of e.g. `objc_retain` and `objc_release`.
unsafe { imp(obj, sel $(, EncodeConvert::__into_inner($a))*) }
}
}
);
}
message_args_impl!();
message_args_impl!(a: A);
message_args_impl!(a: A, b: B);
message_args_impl!(a: A, b: B, c: C);
message_args_impl!(a: A, b: B, c: C, d: D);
message_args_impl!(a: A, b: B, c: C, d: D, e: E);
message_args_impl!(a: A, b: B, c: C, d: D, e: E, f: F);
message_args_impl!(a: A, b: B, c: C, d: D, e: E, f: F, g: G);
message_args_impl!(a: A, b: B, c: C, d: D, e: E, f: F, g: G, h: H);
message_args_impl!(a: A, b: B, c: C, d: D, e: E, f: F, g: G, h: H, i: I);
message_args_impl!(a: A, b: B, c: C, d: D, e: E, f: F, g: G, h: H, i: I, j: J);
message_args_impl!(
a: A,
b: B,
c: C,
d: D,
e: E,
f: F,
g: G,
h: H,
i: I,
j: J,
k: K
);
message_args_impl!(
a: A,
b: B,
c: C,
d: D,
e: E,
f: F,
g: G,
h: H,
i: I,
j: J,
k: K,
l: L
);
#[cfg(test)]
mod tests {
use super::*;
use crate::rc::{Id, Owned};
use crate::test_utils;
use crate::{msg_send, msg_send_id};
#[allow(unused)]
fn test_different_receivers(mut obj: Id<Object, Owned>) {
unsafe {
let x = &mut obj;
let _: () = msg_send![x, mutable1];
// let _: () = msg_send![x, mutable2];
let _: () = msg_send![&mut *obj, mutable1];
let _: () = msg_send![&mut *obj, mutable2];
#[allow(clippy::needless_borrow)]
let obj: NonNull<Object> = (&mut *obj).into();
let _: () = msg_send![obj, mutable1];
let _: () = msg_send![obj, mutable2];
let obj: *mut Object = obj.as_ptr();
let _: () = msg_send![obj, mutable1];
let _: () = msg_send![obj, mutable2];
}
}
#[test]
fn test_send_message() {
let mut obj = test_utils::custom_object();
let result: u32 = unsafe {
let _: () = msg_send![&mut obj, setFoo: 4u32];
msg_send![&obj, foo]
};
assert_eq!(result, 4);
}
#[test]
fn test_send_message_stret() {
let obj = test_utils::custom_object();
let result: test_utils::CustomStruct = unsafe { msg_send![&obj, customStruct] };
let expected = test_utils::CustomStruct {
a: 1,
b: 2,
c: 3,
d: 4,
};
assert_eq!(result, expected);
}
#[test]
#[cfg_attr(
feature = "verify_message",
should_panic = "messsaging description to nil"
)]
fn test_send_message_nil() {
use crate::rc::Shared;
let nil: *mut Object = ::core::ptr::null_mut();
// This result should not be relied on
let result: Option<Id<Object, Shared>> = unsafe { msg_send_id![nil, description] };
assert!(result.is_none());
// This result should not be relied on
let result: usize = unsafe { msg_send![nil, hash] };
assert_eq!(result, 0);
// This result should not be relied on
#[cfg(target_pointer_width = "16")]
let result: f32 = 0.0;
#[cfg(target_pointer_width = "32")]
let result: f32 = unsafe { msg_send![nil, floatValue] };
#[cfg(target_pointer_width = "64")]
let result: f64 = unsafe { msg_send![nil, doubleValue] };
assert_eq!(result, 0.0);
// This result should not be relied on
let result: Option<Id<Object, Shared>> =
unsafe { msg_send_id![nil, multiple: 1u32, arguments: 2i8] };
assert!(result.is_none());
// This result should not be relied on
let result: Option<Id<Object, Shared>> = unsafe { msg_send_id![None, init] };
assert!(result.is_none());
}
#[test]
fn test_send_message_super() {
let mut obj = test_utils::custom_subclass_object();
let superclass = test_utils::custom_class();
unsafe {
let _: () = msg_send![&mut obj, setFoo: 4u32];
let foo: u32 = msg_send![super(&obj, superclass), foo];
assert_eq!(foo, 4);
// The subclass is overriden to return foo + 2
let foo: u32 = msg_send![&obj, foo];
assert_eq!(foo, 6);
}
}
#[test]
fn test_send_message_manuallydrop() {
let obj = ManuallyDrop::new(test_utils::custom_object());
unsafe {
let _: () = msg_send![obj, release];
};
// `obj` is consumed, can't use here
}
}