rustc_attr_parsing/attributes/
transparency.rs

1use rustc_attr_data_structures::AttributeKind;
2use rustc_feature::{AttributeTemplate, template};
3use rustc_span::hygiene::Transparency;
4use rustc_span::{Symbol, sym};
5
6use super::{AttributeOrder, OnDuplicate, SingleAttributeParser};
7use crate::context::{AcceptContext, Stage};
8use crate::parser::ArgParser;
9
10pub(crate) struct TransparencyParser;
11
12// FIXME(jdonszelmann): make these proper diagnostics
13#[allow(rustc::untranslatable_diagnostic)]
14#[allow(rustc::diagnostic_outside_of_impl)]
15impl<S: Stage> SingleAttributeParser<S> for TransparencyParser {
16    const PATH: &[Symbol] = &[sym::rustc_macro_transparency];
17    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst;
18    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Custom(|cx, used, unused| {
19        cx.dcx().span_err(vec![used, unused], "multiple macro transparency attributes");
20    });
21    const TEMPLATE: AttributeTemplate =
22        template!(NameValueStr: "transparent|semitransparent|opaque");
23
24    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
25        let Some(nv) = args.name_value() else {
26            cx.expected_name_value(cx.attr_span, None);
27            return None;
28        };
29        match nv.value_as_str() {
30            Some(sym::transparent) => Some(Transparency::Transparent),
31            Some(sym::semiopaque | sym::semitransparent) => Some(Transparency::SemiOpaque),
32            Some(sym::opaque) => Some(Transparency::Opaque),
33            Some(_) => {
34                cx.expected_specific_argument_strings(
35                    nv.value_span,
36                    vec!["transparent", "semitransparent", "opaque"],
37                );
38                None
39            }
40            None => None,
41        }
42        .map(AttributeKind::MacroTransparency)
43    }
44}
rustc_attr_parsing/attributes/transparency.rs

rustc_attr_parsing/attributes/
transparency.rs
