Closed
Description
openedon Jun 25, 2019
Attempting to run test with proc macro that uses main as identifier fails with following error:
error[E0659]: `main` is ambiguous (built-in attribute vs any other name)
|
= note: `main` could refer to a built-in attribute
note: `main` could also refer to the crate-local procedural macro defined here
--> tokio-macros\src\lib.rs:26:1
|
26| / pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
27| | let input = syn::parse_macro_input!(item as syn::ItemFn);
28| |
29| | let ret = &input.decl.output;
... |
41| | result.into()
42| | }
| |_^
= help: use `crate::main` to refer to this crate-local procedural macro unambiguously
Rustc version:rustc 1.37.0-nightly (8aa42ed7c 2019-06-24)
But it seems it wasn't present in rustc 1.35.0 (3c235d560 2019-05-20)
UPD: It is present since (400b409ef 2019-06-09) too
UPD 2: Might be always present as cargo test seems to inject own main
So something changed in the way such identifier is treated.
Code example:
/// ```
/// #[tokio_macros::main]
/// fn main() {
/// println!("Hello world");
/// }
/// ```
#[proc_macro_attribute]
pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
let input = syn::parse_macro_input!(item as syn::ItemFn);
let ret = &input.decl.output;
let name = &input.ident;
let body = &input.block;
let attrs = &input.attrs;
let result = quote! {
#(#attrs)*
fn #name() #ret {
#body
}
};
result.into()
}Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
