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, 75 deletions

diff --git a/macros/src/codegen/spawn_body.rs b/macros/src/codegen/spawn_body.rs
deleted file mode 100644
index f29393a6..00000000
--- a/macros/src/codegen/spawn_body.rs
+++ /dev/null
@@ -1,75 +0,0 @@
-use proc_macro2::TokenStream as TokenStream2;
-use quote::quote;
-use rtic_syntax::{ast::App, Context};
-use syn::Ident;
-
-use crate::{analyze::Analysis, check::Extra, codegen::util};
-
-pub fn codegen(
-    spawner: Context,
-    name: &Ident,
-    app: &App,
-    analysis: &Analysis,
-    _extra: &Extra,
-) -> TokenStream2 {
-    let spawnee = &app.software_tasks[name];
-    let priority = spawnee.args.priority;
-
-    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 t = util::spawn_t_ident(priority);
-    let fq = util::fq_ident(name);
-    let rq = util::rq_ident(priority);
-    let (dequeue, enqueue) = if spawner.is_init() {
-        (
-            quote!(#fq.dequeue()),
-            quote!(#rq.enqueue_unchecked((#t::#name, index));),
-        )
-    } else {
-        (
-            quote!((#fq { priority }.lock(|fq| fq.split().1.dequeue()))),
-            quote!((#rq { priority }.lock(|rq| {
-                rq.split().0.enqueue_unchecked((#t::#name, index))
-            }));),
-        )
-    };
-
-    let enum_ = util::interrupt_ident();
-    let interrupt = &analysis.interrupts.get(&priority);
-    let pend = {
-        quote!(
-            rtic::pend(you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#enum_::#interrupt);
-        )
-    };
-
-    let (_, tupled, _, _) = util::regroup_inputs(&spawnee.inputs);
-    let inputs = util::inputs_ident(name);
-    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
-
-                #enqueue
-
-                #pend
-
-                Ok(())
-            } else {
-                Err(input)
-            }
-        }
-    )
-}