| use crate::ToTokens; |
| use proc_macro2::{Span, TokenStream}; |
| |
| pub trait Spanned { |
| fn __span(&self) -> Span; |
| } |
| |
| impl Spanned for Span { |
| fn __span(&self) -> Span { |
| *self |
| } |
| } |
| |
| impl<T: ?Sized + ToTokens> Spanned for T { |
| fn __span(&self) -> Span { |
| join_spans(self.into_token_stream()) |
| } |
| } |
| |
| fn join_spans(tokens: TokenStream) -> Span { |
| let mut iter = tokens.into_iter().filter_map(|tt| { |
| // FIXME: This shouldn't be required, since optimally spans should |
| // never be invalid. This filter_map can probably be removed when |
| // https://github.com/rust-lang/rust/issues/43081 is resolved. |
| let span = tt.span(); |
| let debug = format!("{:?}", span); |
| if debug.ends_with("bytes(0..0)") { |
| None |
| } else { |
| Some(span) |
| } |
| }); |
| |
| let first = match iter.next() { |
| Some(span) => span, |
| None => return Span::call_site(), |
| }; |
| |
| iter.fold(None, |_prev, next| Some(next)) |
| .and_then(|last| first.join(last)) |
| .unwrap_or(first) |
| } |
