rust/tests/incremental/issue-85197-invalid-span/auxiliary/respan.rs

20 lines
540 B
Rust

//@ force-host
//@ no-prefer-dynamic
#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::TokenStream;
/// Copies the resolution information (the `SyntaxContext`) of the first
/// token to all other tokens in the stream. Does not recurse into groups.
#[proc_macro]
pub fn respan(input: TokenStream) -> TokenStream {
let first_span = input.clone().into_iter().next().unwrap().span();
input.into_iter().map(|mut tree| {
tree.set_span(tree.span().resolved_at(first_span));
tree
}).collect()
}