ZIm/crates/gpui2_macros/src/register_action.rs

87 lines
2.5 KiB
Rust

// Input:
//
// struct FooBar {}
// Output:
//
// struct FooBar {}
//
// #[allow(non_snake_case)]
// #[gpui2::ctor]
// fn register_foobar_builder() {
// gpui2::register_action_builder::<Foo>()
// }
use proc_macro::TokenStream;
use proc_macro2::Ident;
use quote::{format_ident, quote};
use syn::{parse_macro_input, DeriveInput, Error};
pub fn register_action_macro(_attr: TokenStream, item: TokenStream) -> TokenStream {
let input = parse_macro_input!(item as DeriveInput);
let registration = register_action(&input.ident);
let has_action_derive = input
.attrs
.iter()
.find(|attr| {
(|| {
let meta = attr.parse_meta().ok()?;
meta.path().is_ident("derive").then(|| match meta {
syn::Meta::Path(_) => None,
syn::Meta::NameValue(_) => None,
syn::Meta::List(list) => list
.nested
.iter()
.find(|list| match list {
syn::NestedMeta::Meta(meta) => meta.path().is_ident("Action"),
syn::NestedMeta::Lit(_) => false,
})
.map(|_| true),
})?
})()
.unwrap_or(false)
})
.is_some();
if has_action_derive {
return Error::new(
input.ident.span(),
"The Action derive macro has already registered this action",
)
.into_compile_error()
.into();
}
TokenStream::from(quote! {
#input
#registration
})
}
pub(crate) fn register_action(type_name: &Ident) -> proc_macro2::TokenStream {
let static_slice_name =
format_ident!("__GPUI_ACTIONS_{}", type_name.to_string().to_uppercase());
let action_builder_fn_name = format_ident!(
"__gpui_actions_builder_{}",
type_name.to_string().to_lowercase()
);
quote! {
#[doc(hidden)]
#[gpui::linkme::distributed_slice(gpui::__GPUI_ACTIONS)]
#[linkme(crate = gpui::linkme)]
static #static_slice_name: gpui::MacroActionBuilder = #action_builder_fn_name;
/// This is an auto generated function, do not use.
#[doc(hidden)]
fn #action_builder_fn_name() -> gpui::ActionData {
gpui::ActionData {
name: ::std::any::type_name::<#type_name>(),
type_id: ::std::any::TypeId::of::<#type_name>(),
build: <#type_name as gpui::Action>::build,
}
}
}
}