Merge #390

390: Spawn and schedule from anywhere r=AfoHT a=korken89

This PR moves RTIC to the spawn and schedule from anywhere syntax.

Notable changes:
 * We do no longer support non-`Send` types.
 * Some extra code is generated as any task may spawn/schedule any task. However Rust/LLVM does a great job optimizing away non used instantiations (no real code-size difference observed).
 * Worst case priority inversion has increased, but it is now predictable.

Upsides:
 * With this we should be able to support async/await.
 * RTIC tasks can now be callbacks (spawned and scheduled).
 * RTIC tasks can be stored.

Needs the following PR to land first: https://github.com/rtic-rs/rtic-syntax/pull/34

The following now works:

```rust
#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
mod app {
    #[init]
    fn init(mut cx: init::Context) -> init::LateResources {
        // Init stuff...

        // New spawn syntax
        foo::spawn().unwrap();

        // New schedule syntax
        bar::schedule(now + 4_000_000.cycles()).unwrap();

        init::LateResources {}
    }

    #[task]
    fn foo(_: foo::Context) {}

    #[task]
    fn bar(_: bar::Context) {}

    extern "C" {
        fn SSI0();
    }
}

```

Co-authored-by: Per Lindgren <per.lindgren@ltu.se>
Co-authored-by: Emil Fresk <emil.fresk@gmail.com>

1 files changed, 0 insertions, 59 deletions

diff --git a/macros/src/codegen/schedule_body.rs b/macros/src/codegen/schedule_body.rs
deleted file mode 100644
index 644930d7..00000000
--- a/macros/src/codegen/schedule_body.rs
+++ /dev/null
@@ -1,59 +0,0 @@
-use proc_macro2::TokenStream as TokenStream2;
-use quote::quote;
-use rtic_syntax::{ast::App, Context};
-use syn::Ident;
-
-use crate::codegen::util;
-
-pub fn codegen(scheduler: Context, name: &Ident, app: &App) -> TokenStream2 {
-    let schedulee = &app.software_tasks[name];
-
-    let fq = util::fq_ident(name);
-    let tq = util::tq_ident();
-    let (dequeue, enqueue) = if scheduler.is_init() {
-        (quote!(#fq.dequeue()), quote!(#tq.enqueue_unchecked(nr);))
-    } else {
-        (
-            quote!((#fq { priority }).lock(|fq| fq.split().1.dequeue())),
-            quote!((#tq { priority }).lock(|tq| tq.enqueue_unchecked(nr));),
-        )
-    };
-
-    let write_instant = if app.uses_schedule() {
-        let instants = util::instants_ident(name);
-
-        Some(quote!(
-            #instants.get_unchecked_mut(usize::from(index)).as_mut_ptr().write(instant);
-        ))
-    } else {
-        None
-    };
-
-    let (_, tupled, _, _) = util::regroup_inputs(&schedulee.inputs);
-    let inputs = util::inputs_ident(name);
-    let t = util::schedule_t_ident();
-    quote!(
-        unsafe {
-            use rtic::Mutex as _;
-
-            let input = #tupled;
-            if let Some(index) = #dequeue {
-                #inputs.get_unchecked_mut(usize::from(index)).as_mut_ptr().write(input);
-
-                #write_instant
-
-                let nr = rtic::export::NotReady {
-                    instant,
-                    index,
-                    task: #t::#name,
-                };
-
-                #enqueue
-
-                Ok(())
-            } else {
-                Err(input)
-            }
-        }
-    )
-}