rustc_attr_parsing/attributes/diagnostic/
on_unimplemented.rs

1use rustc_hir::attrs::diagnostic::Directive;
2use rustc_hir::lints::AttributeLintKind;
3use rustc_session::lint::builtin::MALFORMED_DIAGNOSTIC_ATTRIBUTES;
4
5use crate::attributes::diagnostic::*;
6use crate::attributes::prelude::*;
7
8#[derive(#[automatically_derived]
impl ::core::default::Default for OnUnimplementedParser {
    #[inline]
    fn default() -> OnUnimplementedParser {
        OnUnimplementedParser {
            span: ::core::default::Default::default(),
            directive: ::core::default::Default::default(),
        }
    }
}Default)]
9pub(crate) struct OnUnimplementedParser {
10    span: Option<Span>,
11    directive: Option<(Span, Directive)>,
12}
13
14impl OnUnimplementedParser {
15    fn parse<'sess, S: Stage>(
16        &mut self,
17        cx: &mut AcceptContext<'_, 'sess, S>,
18        args: &ArgParser,
19        mode: Mode,
20    ) {
21        let span = cx.attr_span;
22        self.span = Some(span);
23
24        // If target is not a trait, returning early will make `finalize` emit a
25        // `AttributeKind::OnUnimplemented {span, directive: None }`, to prevent it being
26        // accidentally used on non-trait items like trait aliases.
27        if !#[allow(non_exhaustive_omitted_patterns)] match cx.target {
    Target::Trait => true,
    _ => false,
}matches!(cx.target, Target::Trait) {
28            // Lint later emitted in check_attr
29            return;
30        }
31
32        let items = match args {
33            ArgParser::List(items) if items.len() != 0 => items,
34            ArgParser::NoArgs | ArgParser::List(_) => {
35                cx.emit_lint(
36                    MALFORMED_DIAGNOSTIC_ATTRIBUTES,
37                    AttributeLintKind::MissingOptionsForOnUnimplemented,
38                    span,
39                );
40                return;
41            }
42            ArgParser::NameValue(_) => {
43                cx.emit_lint(
44                    MALFORMED_DIAGNOSTIC_ATTRIBUTES,
45                    AttributeLintKind::MalformedOnUnimplementedAttr { span },
46                    span,
47                );
48                return;
49            }
50        };
51
52        if let Some(directive) = parse_directive_items(cx, mode, items.mixed(), true) {
53            merge_directives(cx, &mut self.directive, (span, directive));
54        };
55    }
56}
57
58impl<S: Stage> AttributeParser<S> for OnUnimplementedParser {
59    const ATTRIBUTES: AcceptMapping<Self, S> = &[
60        (
61            &[sym::diagnostic, sym::on_unimplemented],
62            ::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 = "...""#]),
63            |this, cx, args| {
64                this.parse(cx, args, Mode::DiagnosticOnUnimplemented);
65            },
66        ),
67        (
68            &[sym::rustc_on_unimplemented],
69            ::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 = "...""#]),
70            |this, cx, args| {
71                this.parse(cx, args, Mode::RustcOnUnimplemented);
72            },
73        ),
74    ];
75    //FIXME attribute is not parsed for non-traits but diagnostics are issued in `check_attr.rs`
76    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(ALL_TARGETS);
77
78    fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
79        if let Some(span) = self.span {
80            Some(AttributeKind::OnUnimplemented {
81                span,
82                directive: self.directive.map(|d| Box::new(d.1)),
83            })
84        } else {
85            None
86        }
87    }
88}
rustc_attr_parsing/attributes/diagnostic/on_unimplemented.rs

rustc_attr_parsing/attributes/diagnostic/
on_unimplemented.rs
