embassy/embassy-macros/src/macros/cortex_m_interrupt.rs
Dario Nieuwenhuis a8703b7598 Run rustfmt.
2022-06-12 22:22:31 +02:00

67 lines
1.7 KiB
Rust

use std::iter;
use darling::FromMeta;
use proc_macro2::TokenStream;
use quote::quote;
use syn::{ReturnType, Type, Visibility};
use crate::util::ctxt::Ctxt;
#[derive(Debug, FromMeta)]
struct Args {}
pub fn run(args: syn::AttributeArgs, mut f: syn::ItemFn) -> Result<TokenStream, TokenStream> {
let _args = Args::from_list(&args).map_err(|e| e.write_errors())?;
let ident = f.sig.ident.clone();
let ident_s = ident.to_string();
// XXX should we blacklist other attributes?
let valid_signature = f.sig.constness.is_none()
&& f.vis == Visibility::Inherited
&& f.sig.abi.is_none()
&& f.sig.inputs.is_empty()
&& f.sig.generics.params.is_empty()
&& f.sig.generics.where_clause.is_none()
&& f.sig.variadic.is_none()
&& match f.sig.output {
ReturnType::Default => true,
ReturnType::Type(_, ref ty) => match **ty {
Type::Tuple(ref tuple) => tuple.elems.is_empty(),
Type::Never(..) => true,
_ => false,
},
};
let ctxt = Ctxt::new();
if !valid_signature {
ctxt.error_spanned_by(
&f.sig,
"`#[interrupt]` handlers must have signature `[unsafe] fn() [-> !]`",
);
}
ctxt.check()?;
f.block.stmts = iter::once(
syn::parse2(quote! {{
// Check that this interrupt actually exists
let __irq_exists_check: interrupt::#ident;
}})
.unwrap(),
)
.chain(f.block.stmts)
.collect();
let result = quote!(
#[doc(hidden)]
#[export_name = #ident_s]
#[allow(non_snake_case)]
#f
);
Ok(result)
}