rustc_attr_parsing/attributes/
confusables.rs

1use rustc_attr_data_structures::AttributeKind;
2use rustc_feature::template;
3use rustc_span::{Span, Symbol, sym};
4use thin_vec::ThinVec;
5
6use super::{AcceptMapping, AttributeParser};
7use crate::context::{FinalizeContext, Stage};
8use crate::session_diagnostics;
9
10#[derive(Default)]
11pub(crate) struct ConfusablesParser {
12    confusables: ThinVec<Symbol>,
13    first_span: Option<Span>,
14}
15
16impl<S: Stage> AttributeParser<S> for ConfusablesParser {
17    const ATTRIBUTES: AcceptMapping<Self, S> = &[(
18        &[sym::rustc_confusables],
19        template!(List: r#""name1", "name2", ..."#),
20        |this, cx, args| {
21            let Some(list) = args.list() else {
22                cx.expected_list(cx.attr_span);
23                return;
24            };
25
26            if list.is_empty() {
27                cx.emit_err(session_diagnostics::EmptyConfusables { span: cx.attr_span });
28            }
29
30            for param in list.mixed() {
31                let span = param.span();
32
33                let Some(lit) = param.lit().and_then(|i| i.value_str()) else {
34                    cx.expected_string_literal(span, param.lit());
35                    continue;
36                };
37
38                this.confusables.push(lit);
39            }
40
41            this.first_span.get_or_insert(cx.attr_span);
42        },
43    )];
44
45    fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
46        if self.confusables.is_empty() {
47            return None;
48        }
49
50        Some(AttributeKind::Confusables {
51            symbols: self.confusables,
52            first_span: self.first_span.unwrap(),
53        })
54    }
55}