1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
// force-host
// no-prefer-dynamic
#![crate_type = "proc-macro"]
#![feature(proc_macro_span, proc_macro_quote)]
extern crate proc_macro;
use proc_macro::{quote, Span, TokenStream, TokenTree};
fn assert_same_span(a: Span, b: Span) {
assert_eq!(a.start(), b.start());
assert_eq!(a.end(), b.end());
}
// This macro generates a macro with the same macro definition as `manual_foo` in
// `same-sequence-span.rs` but with the same span for all sequences.
#[proc_macro]
pub fn make_foo(_: TokenStream) -> TokenStream {
let result = quote! {
macro_rules! generated_foo {
(1 $$x:expr $$($$y:tt,)* $$(= $$z:tt)*) => {};
}
};
// Check that all spans are equal.
// FIXME: `quote!` gives def-site spans to idents and literals,
// but leaves (default) call-site spans on groups and punctuation.
let mut span_call = None;
let mut span_def = None;
for tt in result.clone() {
match tt {
TokenTree::Ident(..) | TokenTree::Literal(..) => match span_def {
None => span_def = Some(tt.span()),
Some(span) => assert_same_span(tt.span(), span),
}
TokenTree::Punct(..) | TokenTree::Group(..) => match span_call {
None => span_call = Some(tt.span()),
Some(span) => assert_same_span(tt.span(), span),
}
}
}
result
}
|
