Port #[non_exhaustive] to the new attribute parsing infrastructure

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -36,6 +36,7 @@ pub(crate) mod lint_helpers;
 pub(crate) mod loop_match;
 pub(crate) mod must_use;
 pub(crate) mod no_implicit_prelude;
+pub(crate) mod non_exhaustive;
 pub(crate) mod repr;
 pub(crate) mod rustc_internal;
 pub(crate) mod semantics;

compiler/rustc_attr_parsing/src/attributes/non_exhaustive.rs

@@ -0,0 +1,13 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_span::{Span, Symbol, sym};
+
+use crate::attributes::{NoArgsAttributeParser, OnDuplicate};
+use crate::context::Stage;
+
+pub(crate) struct NonExhaustiveParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for NonExhaustiveParser {
+    const PATH: &[Symbol] = &[sym::non_exhaustive];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::NonExhaustive;
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -27,6 +27,7 @@ use crate::attributes::lint_helpers::{AsPtrParser, PassByValueParser, PubTranspa
 use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
+use crate::attributes::non_exhaustive::NonExhaustiveParser;
 use crate::attributes::repr::{AlignParser, ReprParser};
 use crate::attributes::rustc_internal::{
     RustcLayoutScalarValidRangeEnd, RustcLayoutScalarValidRangeStart,
@@ -144,6 +145,7 @@ attribute_parsers!(
         Single<WithoutArgs<MayDangleParser>>,
         Single<WithoutArgs<NoImplicitPreludeParser>>,
         Single<WithoutArgs<NoMangleParser>>,
+        Single<WithoutArgs<NonExhaustiveParser>>,
         Single<WithoutArgs<PassByValueParser>>,
         Single<WithoutArgs<PubTransparentParser>>,
         Single<WithoutArgs<TrackCallerParser>>,