rustc_attr_parsing/attributes/diagnostic/
on_const.rs

1use rustc_hir::attrs::diagnostic::Directive;
2
3use crate::attributes::diagnostic::*;
4use crate::attributes::prelude::*;
5
6#[derive(#[automatically_derived]
impl ::core::default::Default for OnConstParser {
    #[inline]
    fn default() -> OnConstParser {
        OnConstParser {
            span: ::core::default::Default::default(),
            directive: ::core::default::Default::default(),
        }
    }
}Default)]
7pub(crate) struct OnConstParser {
8    span: Option<Span>,
9    directive: Option<(Span, Directive)>,
10}
11
12impl<S: Stage> AttributeParser<S> for OnConstParser {
13    const ATTRIBUTES: AcceptMapping<Self, S> = &[(
14        &[sym::diagnostic, sym::on_const],
15        ::rustc_feature::AttributeTemplate {
    word: false,
    list: Some(&[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
    one_of: &[],
    name_value_str: None,
    docs: None,
}template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
16        |this, cx, args| {
17            if !cx.features().diagnostic_on_const() {
18                // `UnknownDiagnosticAttribute` is emitted in rustc_resolve/macros.rs
19                return;
20            }
21
22            let span = cx.attr_span;
23            this.span = Some(span);
24            let mode = Mode::DiagnosticOnConst;
25
26            let Some(items) = parse_list(cx, args, mode) else { return };
27
28            let Some(directive) = parse_directive_items(cx, mode, items.mixed(), true) else {
29                return;
30            };
31            merge_directives(cx, &mut this.directive, (span, directive));
32        },
33    )];
34
35    //FIXME Still checked in `check_attr.rs`
36    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(ALL_TARGETS);
37
38    fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
39        if let Some(span) = self.span {
40            Some(AttributeKind::OnConst { span, directive: self.directive.map(|d| Box::new(d.1)) })
41        } else {
42            None
43        }
44    }
45}
rustc_attr_parsing/attributes/diagnostic/on_const.rs

rustc_attr_parsing/attributes/diagnostic/
on_const.rs
