Files
rust/compiler/rustc_attr_parsing/src/attributes/transparency.rs

38 lines
1.6 KiB
Rust

use rustc_attr_data_structures::AttributeKind;
use rustc_feature::{AttributeTemplate, template};
use rustc_span::hygiene::Transparency;
use rustc_span::{Symbol, sym};
use super::{AttributeOrder, OnDuplicate, SingleAttributeParser};
use crate::context::{AcceptContext, Stage};
use crate::parser::ArgParser;
pub(crate) struct TransparencyParser;
// FIXME(jdonszelmann): make these proper diagnostics
#[allow(rustc::untranslatable_diagnostic)]
#[allow(rustc::diagnostic_outside_of_impl)]
impl<S: Stage> SingleAttributeParser<S> for TransparencyParser {
const PATH: &[Symbol] = &[sym::rustc_macro_transparency];
const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst;
const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Custom(|cx, used, unused| {
cx.dcx().span_err(vec![used, unused], "multiple macro transparency attributes");
});
const TEMPLATE: AttributeTemplate =
template!(NameValueStr: "transparent|semitransparent|opaque");
fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
match args.name_value().and_then(|nv| nv.value_as_str()) {
Some(sym::transparent) => Some(Transparency::Transparent),
Some(sym::semiopaque | sym::semitransparent) => Some(Transparency::SemiOpaque),
Some(sym::opaque) => Some(Transparency::Opaque),
Some(other) => {
cx.dcx().span_err(cx.attr_span, format!("unknown macro transparency: `{other}`"));
None
}
None => None,
}
.map(AttributeKind::MacroTransparency)
}
}