Merge branch 'main' into rp2040-rtc-alarm

1 files changed, 54 insertions, 2 deletions

diff --git a/embassy-executor/src/lib.rs b/embassy-executor/src/lib.rs
index d6fd3d651..e47b8eb9f 100644
--- a/embassy-executor/src/lib.rs
+++ b/embassy-executor/src/lib.rs
@@ -26,6 +26,7 @@ macro_rules! check_at_most_one {
 check_at_most_one!(
     "arch-avr",
     "arch-cortex-m",
+    "arch-cortex-ar",
     "arch-riscv32",
     "arch-std",
     "arch-wasm",
@@ -35,6 +36,7 @@ check_at_most_one!(
 #[cfg(feature = "_arch")]
 #[cfg_attr(feature = "arch-avr", path = "arch/avr.rs")]
 #[cfg_attr(feature = "arch-cortex-m", path = "arch/cortex_m.rs")]
+#[cfg_attr(feature = "arch-cortex-ar", path = "arch/cortex_ar.rs")]
 #[cfg_attr(feature = "arch-riscv32", path = "arch/riscv32.rs")]
 #[cfg_attr(feature = "arch-std", path = "arch/std.rs")]
 #[cfg_attr(feature = "arch-wasm", path = "arch/wasm.rs")]
@@ -52,6 +54,9 @@ pub mod raw;
 mod spawner;
 pub use spawner::*;
 
+mod metadata;
+pub use metadata::*;
+
 /// Implementation details for embassy macros.
 /// Do not use. Used for macros and HALs only. Not covered by semver guarantees.
 #[doc(hidden)]
@@ -63,8 +68,17 @@ pub mod _export {
 
     use crate::raw::TaskPool;
 
+    trait TaskReturnValue {}
+    impl TaskReturnValue for () {}
+    impl TaskReturnValue for Never {}
+
+    #[diagnostic::on_unimplemented(
+        message = "task futures must resolve to `()` or `!`",
+        note = "use `async fn` or change the return type to `impl Future<Output = ()>`"
+    )]
+    #[allow(private_bounds)]
     pub trait TaskFn<Args>: Copy {
-        type Fut: Future + 'static;
+        type Fut: Future<Output: TaskReturnValue> + 'static;
     }
 
     macro_rules! task_fn_impl {
@@ -72,7 +86,7 @@ pub mod _export {
             impl<F, Fut, $($Tn,)*> TaskFn<($($Tn,)*)> for F
             where
                 F: Copy + FnOnce($($Tn,)*) -> Fut,
-                Fut: Future + 'static,
+                Fut: Future<Output: TaskReturnValue> + 'static,
             {
                 type Fut = Fut;
             }
@@ -203,4 +217,42 @@ pub mod _export {
         Align268435456: 268435456,
         Align536870912: 536870912,
     );
+
+    #[allow(dead_code)]
+    pub trait HasOutput {
+        type Output;
+    }
+
+    impl<O> HasOutput for fn() -> O {
+        type Output = O;
+    }
+
+    #[allow(dead_code)]
+    pub type Never = <fn() -> ! as HasOutput>::Output;
+}
+
+/// Implementation details for embassy macros.
+/// Do not use. Used for macros and HALs only. Not covered by semver guarantees.
+#[doc(hidden)]
+#[cfg(feature = "nightly")]
+pub mod _export {
+    #[diagnostic::on_unimplemented(
+        message = "task futures must resolve to `()` or `!`",
+        note = "use `async fn` or change the return type to `impl Future<Output = ()>`"
+    )]
+    pub trait TaskReturnValue {}
+    impl TaskReturnValue for () {}
+    impl TaskReturnValue for Never {}
+
+    #[allow(dead_code)]
+    pub trait HasOutput {
+        type Output;
+    }
+
+    impl<O> HasOutput for fn() -> O {
+        type Output = O;
+    }
+
+    #[allow(dead_code)]
+    pub type Never = <fn() -> ! as HasOutput>::Output;
 }