29 lines
819 B
Rust
29 lines
819 B
Rust
use syntax::symbol::kw;
|
|
use syntax::tokenstream::{TokenStream, TokenTree};
|
|
use syntax_expand::base::{self, ExtCtxt};
|
|
use syntax_pos::Span;
|
|
|
|
pub fn expand_trace_macros(
|
|
cx: &mut ExtCtxt<'_>,
|
|
sp: Span,
|
|
tt: TokenStream,
|
|
) -> Box<dyn base::MacResult + 'static> {
|
|
let mut cursor = tt.into_trees();
|
|
let mut err = false;
|
|
let value = match &cursor.next() {
|
|
Some(TokenTree::Token(token)) if token.is_keyword(kw::True) => true,
|
|
Some(TokenTree::Token(token)) if token.is_keyword(kw::False) => false,
|
|
_ => {
|
|
err = true;
|
|
false
|
|
}
|
|
};
|
|
err |= cursor.next().is_some();
|
|
if err {
|
|
cx.span_err(sp, "trace_macros! accepts only `true` or `false`")
|
|
} else {
|
|
cx.set_trace_macros(value);
|
|
}
|
|
|
|
base::DummyResult::any_valid(sp)
|
|
}
|