Port #[ignore] to the new attribute parsing infrastructure

Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -41,6 +41,7 @@ pub(crate) mod repr;
 pub(crate) mod rustc_internal;
 pub(crate) mod semantics;
 pub(crate) mod stability;
+pub(crate) mod test_attrs;
 pub(crate) mod traits;
 pub(crate) mod transparency;
 pub(crate) mod util;

compiler/rustc_attr_parsing/src/attributes/test_attrs.rs

@@ -0,0 +1,46 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_attr_data_structures::lints::AttributeLintKind;
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::{Symbol, sym};
+
+use crate::attributes::{AttributeOrder, OnDuplicate, SingleAttributeParser};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct IgnoreParser;
+
+impl<S: Stage> SingleAttributeParser<S> for IgnoreParser {
+    const PATH: &[Symbol] = &[sym::ignore];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const TEMPLATE: AttributeTemplate = template!(Word, NameValueStr: "reason");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        Some(AttributeKind::Ignore {
+            span: cx.attr_span,
+            reason: match args {
+                ArgParser::NoArgs => None,
+                ArgParser::NameValue(name_value) => {
+                    let Some(str_value) = name_value.value_as_str() else {
+                        let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
+                            .suggestions(false, "ignore");
+                        let span = cx.attr_span;
+                        cx.emit_lint(
+                            AttributeLintKind::IllFormedAttributeInput { suggestions },
+                            span,
+                        );
+                        return None;
+                    };
+                    Some(str_value)
+                }
+                ArgParser::List(_) => {
+                    let suggestions =
+                        <Self as SingleAttributeParser<S>>::TEMPLATE.suggestions(false, "ignore");
+                    let span = cx.attr_span;
+                    cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
+                    return None;
+                }
+            },
+        })
+    }
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -37,6 +37,7 @@ use crate::attributes::semantics::MayDangleParser;
 use crate::attributes::stability::{
     BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
 };
+use crate::attributes::test_attrs::IgnoreParser;
 use crate::attributes::traits::SkipDuringMethodDispatchParser;
 use crate::attributes::transparency::TransparencyParser;
 use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs};
@@ -126,6 +127,7 @@ attribute_parsers!(
         // tidy-alphabetical-start
         Single<DeprecationParser>,
         Single<ExportNameParser>,
+        Single<IgnoreParser>,
         Single<InlineParser>,
         Single<LinkNameParser>,
         Single<LinkSectionParser>,