use syn::{parse, ForeignItemFn, ItemFn, Stmt};
use crate::parse::util::FilterAttrs;
use crate::{
ast::{HardwareTask, HardwareTaskArgs},
parse::util,
};
impl HardwareTask {
pub(crate) fn parse(args: HardwareTaskArgs, item: ItemFn) -> parse::Result<Self> {
let span = item.sig.ident.span();
let valid_signature = util::check_fn_signature(&item)
&& item.sig.inputs.len() == 1
&& util::type_is_unit(&item.sig.output);
let name = item.sig.ident.to_string();
if name == "init" || name == "idle" {
return Err(parse::Error::new(
span,
"tasks cannot be named `init` or `idle`",
));
}
if valid_signature {
if let Some((context, Ok(rest))) = util::parse_inputs(item.sig.inputs, &name) {
if rest.is_empty() {
let FilterAttrs { cfgs, attrs, .. } = util::filter_attributes(item.attrs);
return Ok(HardwareTask {
args,
cfgs,
attrs,
context,
stmts: item.block.stmts,
is_extern: false,
});
}
}
}
Err(parse::Error::new(
span,
format!(
"this task handler must have type signature `fn({}::Context)`",
name
),
))
}
}
impl HardwareTask {
pub(crate) fn parse_foreign(
args: HardwareTaskArgs,
item: ForeignItemFn,
) -> parse::Result<Self> {
let span = item.sig.ident.span();
let valid_signature = util::check_foreign_fn_signature(&item)
&& item.sig.inputs.len() == 1
&& util::type_is_unit(&item.sig.output);
let name = item.sig.ident.to_string();
if name == "init" || name == "idle" {
return Err(parse::Error::new(
span,
"tasks cannot be named `init` or `idle`",
));
}
if valid_signature {
if let Some((context, Ok(rest))) = util::parse_inputs(item.sig.inputs, &name) {
if rest.is_empty() {
let FilterAttrs { cfgs, attrs, .. } = util::filter_attributes(item.attrs);
return Ok(HardwareTask {
args,
cfgs,
attrs,
context,
stmts: Vec::<Stmt>::new(),
is_extern: true,
});
}
}
}
Err(parse::Error::new(
span,
format!(
"this task handler must have type signature `fn({}::Context)`",
name
),
))
}
}