rustc_attr_parsing/attributes/
confusables.rs1use rustc_feature::template;
2use rustc_hir::attrs::AttributeKind;
3use rustc_hir::{MethodKind, Target};
4use rustc_span::{Span, Symbol, sym};
5use thin_vec::ThinVec;
6
7use super::{AcceptMapping, AttributeParser};
8use crate::context::MaybeWarn::Allow;
9use crate::context::{AllowedTargets, FinalizeContext, Stage};
10use crate::session_diagnostics;
11#[derive(Default)]
12pub(crate) struct ConfusablesParser {
13 confusables: ThinVec<Symbol>,
14 first_span: Option<Span>,
15}
16
17impl<S: Stage> AttributeParser<S> for ConfusablesParser {
18 const ATTRIBUTES: AcceptMapping<Self, S> = &[(
19 &[sym::rustc_confusables],
20 template!(List: &[r#""name1", "name2", ..."#]),
21 |this, cx, args| {
22 let Some(list) = args.list() else {
23 cx.expected_list(cx.attr_span);
24 return;
25 };
26
27 if list.is_empty() {
28 cx.emit_err(session_diagnostics::EmptyConfusables { span: cx.attr_span });
29 }
30
31 for param in list.mixed() {
32 let span = param.span();
33
34 let Some(lit) = param.lit().and_then(|i| i.value_str()) else {
35 cx.expected_string_literal(span, param.lit());
36 continue;
37 };
38
39 this.confusables.push(lit);
40 }
41
42 this.first_span.get_or_insert(cx.attr_span);
43 },
44 )];
45 const ALLOWED_TARGETS: AllowedTargets =
46 AllowedTargets::AllowList(&[Allow(Target::Method(MethodKind::Inherent))]);
47
48 fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
49 if self.confusables.is_empty() {
50 return None;
51 }
52
53 Some(AttributeKind::Confusables {
54 symbols: self.confusables,
55 first_span: self.first_span.unwrap(),
56 })
57 }
58}