embassy, embassy-nrf: add nightly Cargo feature to gate nightly-only features.

embassy/Cargo.toml

@@ -10,8 +10,12 @@ default = []
 std = ["futures/std", "time", "time-tick-1mhz", "embassy-macros/std"]
 wasm = ["wasm-bindgen", "js-sys", "embassy-macros/wasm", "wasm-timer", "time", "time-tick-1mhz"]
 
+# Enable nightly-only features
+nightly = ["embedded-hal-async"]
+
 # Implement embedded-hal 1.0 alpha and embedded-hal-async traits.
-unstable-traits = ["embedded-hal-1", "embedded-hal-async"]
+# Implement embedded-hal-async traits if `nightly` is set as well.
+unstable-traits = ["embedded-hal-1"]
 
 # Enable `embassy::time` module. 
 # NOTE: This feature is only intended to be enabled by crates providing the time driver implementation.

embassy/src/channel/signal.rs

@@ -32,13 +32,15 @@ enum State<T> {
 unsafe impl<T: Send> Send for Signal<T> {}
 unsafe impl<T: Send> Sync for Signal<T> {}
 
-impl<T: Send> Signal<T> {
+impl<T> Signal<T> {
     pub const fn new() -> Self {
         Self {
             state: UnsafeCell::new(State::None),
         }
     }
+}
 
+impl<T: Send> Signal<T> {
     /// Mark this Signal as completed.
     pub fn signal(&self, val: T) {
         critical_section::with(|_| unsafe {

embassy/src/executor/raw/mod.rs

@@ -57,6 +57,7 @@ pub struct TaskHeader {
 }
 
 impl TaskHeader {
+    #[cfg(feature = "nightly")]
     pub(crate) const fn new() -> Self {
         Self {
             state: AtomicU32::new(0),
@@ -71,6 +72,21 @@ impl TaskHeader {
         }
     }
 
+    #[cfg(not(feature = "nightly"))]
+    pub(crate) fn new() -> Self {
+        Self {
+            state: AtomicU32::new(0),
+            run_queue_item: RunQueueItem::new(),
+            executor: Cell::new(ptr::null()),
+            poll_fn: UninitCell::uninit(),
+
+            #[cfg(feature = "time")]
+            expires_at: Cell::new(Instant::from_ticks(0)),
+            #[cfg(feature = "time")]
+            timer_queue_item: timer_queue::TimerQueueItem::new(),
+        }
+    }
+
     pub(crate) unsafe fn enqueue(&self) {
         critical_section::with(|cs| {
             let state = self.state.load(Ordering::Relaxed);
@@ -113,7 +129,8 @@ pub struct TaskStorage<F: Future + 'static> {
 }
 
 impl<F: Future + 'static> TaskStorage<F> {
-    /// Create a new Task, in not-spawned state.
+    /// Create a new TaskStorage, in not-spawned state.
+    #[cfg(feature = "nightly")]
     pub const fn new() -> Self {
         Self {
             raw: TaskHeader::new(),
@@ -121,6 +138,15 @@ impl<F: Future + 'static> TaskStorage<F> {
         }
     }
 
+    /// Create a new TaskStorage, in not-spawned state.
+    #[cfg(not(feature = "nightly"))]
+    pub fn new() -> Self {
+        Self {
+            raw: TaskHeader::new(),
+            future: UninitCell::uninit(),
+        }
+    }
+
     /// Try to spawn a task in a pool.
     ///
     /// See [`Self::spawn()`] for details.

embassy/src/lib.rs

@@ -1,8 +1,13 @@
 #![cfg_attr(not(any(feature = "std", feature = "wasm")), no_std)]
-#![feature(generic_associated_types)]
-#![feature(const_fn_trait_bound)]
-#![feature(const_fn_fn_ptr_basics)]
-#![feature(type_alias_impl_trait)]
+#![cfg_attr(
+    feature = "nightly",
+    feature(
+        const_fn_trait_bound,
+        const_fn_fn_ptr_basics,
+        generic_associated_types,
+        type_alias_impl_trait
+    )
+)]
 #![allow(clippy::new_without_default)]
 
 // This mod MUST go first, so that the others see its macros.
@@ -20,7 +25,8 @@ pub mod io;
 pub mod time;
 pub mod util;
 
-pub use embassy_macros::*;
+#[cfg(feature = "nightly")]
+pub use embassy_macros::{main, task};
 
 #[doc(hidden)]
 /// Implementation details for embassy macros. DO NOT USE.

embassy/src/time/delay.rs

@@ -16,11 +16,7 @@ pub struct Delay;
 
 #[cfg(feature = "unstable-traits")]
 mod eh1 {
-    use core::future::Future;
-    use futures::FutureExt;
-
     use super::*;
-    use crate::time::Timer;
 
     impl embedded_hal_1::delay::blocking::DelayUs for Delay {
         type Error = core::convert::Infallible;
@@ -33,6 +29,14 @@ mod eh1 {
             Ok(block_for(Duration::from_millis(ms as u64)))
         }
     }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eh1a {
+    use super::*;
+    use crate::time::Timer;
+    use core::future::Future;
+    use futures::FutureExt;
 
     impl embedded_hal_async::delay::DelayUs for Delay {
         type Error = core::convert::Infallible;