rustc_attr_parsing/attributes/
transparency.rs

1use rustc_feature::AttributeStability;
2use rustc_span::hygiene::Transparency;
3
4use super::prelude::*;
5
6pub(crate) struct RustcMacroTransparencyParser;
7
8impl SingleAttributeParser for RustcMacroTransparencyParser {
9    const PATH: &[Symbol] = &[sym::rustc_macro_transparency];
10    const ON_DUPLICATE: OnDuplicate = OnDuplicate::Custom(|cx, used, unused| {
11        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");
12    });
13    const STABILITY: AttributeStability = AttributeStability::Unstable {
    gate_name: rustc_span::sym::rustc_attrs,
    gate_check: rustc_feature::Features::rustc_attrs,
    notes: &[],
}unstable!(rustc_attrs);
14    const ALLOWED_TARGETS: AllowedTargets<'_> =
15        AllowedTargets::AllowList(&[Allow(Target::MacroDef)]);
16    const TEMPLATE: AttributeTemplate =
17        crate::AttributeTemplate {
    word: false,
    list: None,
    one_of: &[],
    name_value_str: Some(&["transparent", "semiopaque", "opaque"]),
    docs: None,
}template!(NameValueStr: ["transparent", "semiopaque", "opaque"]);
18
19    fn convert(cx: &mut AcceptContext<'_, '_>, args: &ArgParser) -> Option<AttributeKind> {
20        let nv = cx.expect_name_value(args, cx.attr_span, None)?;
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.adcx().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
