rustc_attr_parsing/attributes/diagnostic/
on_type_error.rs

1use rustc_hir::attrs::AttributeKind;
2use rustc_span::sym;
3
4use crate::attributes::AttributeStability;
5use crate::attributes::diagnostic::*;
6use crate::attributes::prelude::*;
7use crate::context::AcceptContext;
8use crate::parser::ArgParser;
9use crate::target_checking::AllowedTargets;
10use crate::template;
11
12#[derive(#[automatically_derived]
impl ::core::default::Default for OnTypeErrorParser {
    #[inline]
    fn default() -> OnTypeErrorParser {
        OnTypeErrorParser {
            span: ::core::default::Default::default(),
            directive: ::core::default::Default::default(),
        }
    }
}Default)]
13pub(crate) struct OnTypeErrorParser {
14    span: Option<Span>,
15    directive: Option<(Span, Directive)>,
16}
17
18impl OnTypeErrorParser {
19    fn parse<'sess>(&mut self, cx: &mut AcceptContext<'_, 'sess>, args: &ArgParser, mode: Mode) {
20        if !cx.features().diagnostic_on_type_error() {
21            // `UnknownDiagnosticAttribute` is emitted in rustc_resolve/macros.rs
22            args.ignore_args();
23            return;
24        }
25
26        let span = cx.attr_span;
27        self.span = Some(span);
28
29        let Some(items) = parse_list(cx, args, mode) else { return };
30
31        if let Some(directive) = parse_directive_items(cx, mode, items.mixed(), true) {
32            merge_directives(cx, &mut self.directive, (span, directive));
33        }
34    }
35}
36
37impl AttributeParser for OnTypeErrorParser {
38    const ATTRIBUTES: AcceptMapping<Self> = &[(
39        &[sym::diagnostic, sym::on_type_error],
40        crate::AttributeTemplate {
    word: false,
    list: Some(&[r#"note = "...""#]),
    one_of: &[],
    name_value_str: None,
    docs: None,
}template!(List: &[r#"note = "...""#]),
41        AttributeStability::Stable,
42        |this, cx, args| {
43            this.parse(cx, args, Mode::DiagnosticOnTypeError);
44        },
45    )];
46
47    const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowListWarnRest(&[
48        Allow(Target::Enum),
49        Allow(Target::Struct),
50        Allow(Target::Union),
51    ]);
52
53    fn finalize(self, _cx: &FinalizeContext<'_, '_>) -> Option<AttributeKind> {
54        if let Some(span) = self.span {
55            Some(AttributeKind::OnTypeError {
56                span,
57                directive: self.directive.map(|d| Box::new(d.1)),
58            })
59        } else {
60            None
61        }
62    }
63}
rustc_attr_parsing/attributes/diagnostic/on_type_error.rs

rustc_attr_parsing/attributes/diagnostic/
on_type_error.rs
