rustc_attr_parsing/attributes/
transparency.rs1use 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::Error;
11 const STABILITY: AttributeStability = AttributeStability::Unstable {
gate_name: rustc_span::sym::rustc_attrs,
gate_check: rustc_feature::Features::rustc_attrs,
notes: &[],
}unstable!(rustc_attrs);
12 const ALLOWED_TARGETS: AllowedTargets<'_> =
13 AllowedTargets::AllowList(&[Allow(Target::MacroDef)]);
14 const TEMPLATE: AttributeTemplate =
15 crate::AttributeTemplate {
word: false,
list: None,
one_of: &[],
name_value_str: Some(&["transparent", "semiopaque", "opaque"]),
docs: None,
}template!(NameValueStr: ["transparent", "semiopaque", "opaque"]);
16
17 fn convert(cx: &mut AcceptContext<'_, '_>, args: &ArgParser) -> Option<AttributeKind> {
18 let nv = cx.expect_name_value(args, cx.attr_span, None)?;
19 match nv.value_as_str() {
20 Some(sym::transparent) => Some(Transparency::Transparent),
21 Some(sym::semiopaque) => Some(Transparency::SemiOpaque),
22 Some(sym::opaque) => Some(Transparency::Opaque),
23 Some(_) => {
24 cx.adcx().expected_specific_argument_strings(
25 nv.value_span,
26 &[sym::transparent, sym::semiopaque, sym::opaque],
27 );
28 None
29 }
30 None => None,
31 }
32 .map(AttributeKind::RustcMacroTransparency)
33 }
34}