rustc_attr_parsing/attributes/
transparency.rs

1use rustc_span::hygiene::Transparency;
2
3use super::prelude::*;
4
5pub(crate) struct RustcMacroTransparencyParser;
6
7impl<S: Stage> SingleAttributeParser<S> for RustcMacroTransparencyParser {
8    const PATH: &[Symbol] = &[sym::rustc_macro_transparency];
9    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Custom(|cx, used, unused| {
10        cx.dcx().span_err(::alloc::boxed::box_assume_init_into_vec_unsafe(::alloc::intrinsics::write_box_via_move(::alloc::boxed::Box::new_uninit(),
        [used, unused]))vec![used, unused], "multiple macro transparency attributes");
11    });
12    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::MacroDef)]);
13    const TEMPLATE: AttributeTemplate =
14        ::rustc_feature::AttributeTemplate {
    word: false,
    list: None,
    one_of: &[],
    name_value_str: Some(&["transparent", "semiopaque", "opaque"]),
    docs: None,
}template!(NameValueStr: ["transparent", "semiopaque", "opaque"]);
15
16    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser) -> Option<AttributeKind> {
17        let Some(nv) = args.name_value() else {
18            cx.expected_name_value(cx.attr_span, None);
19            return None;
20        };
21        match nv.value_as_str() {
22            Some(sym::transparent) => Some(Transparency::Transparent),
23            Some(sym::semiopaque) => Some(Transparency::SemiOpaque),
24            Some(sym::opaque) => Some(Transparency::Opaque),
25            Some(_) => {
26                cx.expected_specific_argument_strings(
27                    nv.value_span,
28                    &[sym::transparent, sym::semiopaque, sym::opaque],
29                );
30                None
31            }
32            None => None,
33        }
34        .map(AttributeKind::RustcMacroTransparency)
35    }
36}
rustc_attr_parsing/attributes/transparency.rs

rustc_attr_parsing/attributes/
transparency.rs
