Add support for log+defmt again, but better.

embassy/Cargo.toml

@@ -13,7 +13,8 @@ defmt-warn = []
 defmt-error = []
 
 [dependencies]
-defmt = { version = "0.1.0" }
+defmt = { version = "0.1.3", optional = true }
+log = { version = "0.4.11", optional = true }
 
 cortex-m = "0.6.4"
 futures     = { version = "0.3.5", default-features = false }

embassy/src/executor/executor.rs

@@ -63,7 +63,8 @@ pub struct Task<F: Future + 'static> {
     future: UninitCell<F>, // Valid if STATE_RUNNING
 }
 
-#[derive(Copy, Clone, Debug, defmt::Format)]
+#[derive(Copy, Clone, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum SpawnError {
     Busy,
 }

embassy/src/flash.rs

@@ -1,6 +1,7 @@
 use core::future::Future;
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq, defmt::Format)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
     Failed,
     AddressMisaligned,

embassy/src/fmt.rs

@@ -0,0 +1,110 @@
+#![macro_use]
+
+#[cfg(all(feature = "defmt", feature = "log"))]
+compile_error!("You may not enable both `defmt` and `log` features.");
+
+pub use fmt::*;
+
+#[cfg(feature = "defmt")]
+mod fmt {
+    pub use defmt::{
+        assert, assert_eq, assert_ne, debug, debug_assert, debug_assert_eq, debug_assert_ne, error,
+        info, panic, todo, trace, unreachable, unwrap, warn,
+    };
+}
+
+#[cfg(feature = "log")]
+mod fmt {
+    pub use core::{
+        assert, assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, panic, todo,
+        unreachable,
+    };
+    pub use log::{debug, error, info, trace, warn};
+}
+
+#[cfg(not(any(feature = "defmt", feature = "log")))]
+mod fmt {
+    #![macro_use]
+
+    pub use core::{
+        assert, assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, panic, todo,
+        unreachable,
+    };
+
+    #[macro_export]
+    macro_rules! trace {
+        ($($msg:expr),*) => {
+            ()
+        };
+    }
+
+    #[macro_export]
+    macro_rules! debug {
+        ($($msg:expr),*) => {
+            ()
+        };
+    }
+
+    #[macro_export]
+    macro_rules! info {
+        ($($msg:expr),*) => {
+            ()
+        };
+    }
+
+    #[macro_export]
+    macro_rules! warn {
+        ($($msg:expr),*) => {
+            ()
+        };
+    }
+
+    #[macro_export]
+    macro_rules! error {
+        ($($msg:expr),*) => {
+            ()
+        };
+    }
+}
+
+#[cfg(not(feature = "defmt"))]
+#[macro_export]
+macro_rules! unwrap {
+    ($arg:expr$(,$msg:expr)*) => {
+        match $crate::fmt::Try::into_result($arg) {
+            ::core::result::Result::Ok(t) => t,
+            ::core::result::Result::Err(e) => {
+                panic!($($msg,)*);
+            }
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct NoneError;
+
+pub trait Try {
+    type Ok;
+    type Error;
+    fn into_result(self) -> Result<Self::Ok, Self::Error>;
+}
+
+impl<T> Try for Option<T> {
+    type Ok = T;
+    type Error = NoneError;
+
+    #[inline]
+    fn into_result(self) -> Result<T, NoneError> {
+        self.ok_or(NoneError)
+    }
+}
+
+impl<T, E> Try for Result<T, E> {
+    type Ok = T;
+    type Error = E;
+
+    #[inline]
+    fn into_result(self) -> Self {
+        self
+    }
+}

embassy/src/io/error.rs

@@ -2,7 +2,8 @@
 ///
 /// This list is intended to grow over time and it is not recommended to
 /// exhaustively match against it.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, defmt::Format)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
     /// An entity was not found, often a file.
     NotFound,

embassy/src/lib.rs

@@ -4,6 +4,9 @@
 #![feature(const_fn)]
 #![feature(const_fn_fn_ptr_basics)]
 
+// This mod MUST go first, so that the others see its macros.
+pub(crate) mod fmt;
+
 pub mod executor;
 pub mod flash;
 pub mod io;

embassy/src/rand.rs

@@ -1,4 +1,4 @@
-use defmt::*;
+use crate::fmt::*;
 
 pub trait Rand {
     fn rand(&self, buf: &mut [u8]);

embassy/src/time/duration.rs

@@ -3,7 +3,8 @@ use core::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
 
 use super::TICKS_PER_SECOND;
 
-#[derive(Debug, Default, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, defmt::Format)]
+#[derive(Debug, Default, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Duration {
     pub(crate) ticks: u64,
 }

embassy/src/time/instant.rs

@@ -5,7 +5,8 @@ use core::ops::{Add, AddAssign, Sub, SubAssign};
 use super::TICKS_PER_SECOND;
 use super::{now, Duration};
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, defmt::Format)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Instant {
     ticks: u64,
 }

embassy/src/time/mod.rs

@@ -8,7 +8,7 @@ pub use instant::Instant;
 pub use timer::Timer;
 pub use traits::*;
 
-use defmt::*;
+use crate::fmt::*;
 
 // TODO allow customizing, probably via Cargo features `tick-hz-32768` or something.
 pub const TICKS_PER_SECOND: u64 = 32768;

embassy/src/util/drop_bomb.rs

@@ -1,5 +1,5 @@
+use crate::fmt::panic;
 use core::mem;
-use defmt::panic;
 
 pub struct DropBomb {
     _private: (),

embassy/src/util/portal.rs

@@ -1,8 +1,8 @@
+use crate::fmt::panic;
 use core::cell::UnsafeCell;
 use core::future::Future;
 use core::mem;
 use core::mem::MaybeUninit;
-use defmt::panic;
 
 use crate::util::*;
 

embassy/src/util/signal.rs

@@ -1,8 +1,8 @@
+use crate::fmt::panic;
 use core::cell::UnsafeCell;
 use core::future::Future;
 use core::mem;
 use core::task::{Context, Poll, Waker};
-use defmt::panic;
 
 pub struct Signal<T> {
     state: UnsafeCell<State<T>>,