Port rustc_regions to the new attribute parser

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -219,6 +219,22 @@ impl<S: Stage> NoArgsAttributeParser<S> for RustcLintQueryInstabilityParser {
     const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcLintQueryInstability;
 }
 
+pub(crate) struct RustcRegionsParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcRegionsParser {
+    const PATH: &[Symbol] = &[sym::rustc_regions];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Fn),
+        Allow(Target::Method(MethodKind::Inherent)),
+        Allow(Target::Method(MethodKind::Trait { body: false })),
+        Allow(Target::Method(MethodKind::Trait { body: true })),
+        Allow(Target::Method(MethodKind::TraitImpl)),
+    ]);
+
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcRegions;
+}
+
 pub(crate) struct RustcLintUntrackedQueryInformationParser;
 
 impl<S: Stage> NoArgsAttributeParser<S> for RustcLintUntrackedQueryInformationParser {

compiler/rustc_attr_parsing/src/context.rs

@@ -276,6 +276,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcPassIndirectlyInNonRusticAbisParser>>,
         Single<WithoutArgs<RustcPreserveUbChecksParser>>,
         Single<WithoutArgs<RustcReallocatorParser>>,
+        Single<WithoutArgs<RustcRegionsParser>>,
         Single<WithoutArgs<RustcShouldNotBeCalledOnConstItems>>,
         Single<WithoutArgs<RustcVarianceOfOpaquesParser>>,
         Single<WithoutArgs<RustcVarianceParser>>,

compiler/rustc_borrowck/src/nll.rs

@@ -7,6 +7,8 @@ use std::str::FromStr;
 
 use polonius_engine::{Algorithm, AllFacts, Output};
 use rustc_data_structures::frozen::Frozen;
+use rustc_hir::attrs::AttributeKind;
+use rustc_hir::find_attr;
 use rustc_index::IndexSlice;
 use rustc_middle::mir::pretty::PrettyPrintMirOptions;
 use rustc_middle::mir::{Body, MirDumper, PassWhere, Promoted};
@@ -15,7 +17,6 @@ use rustc_middle::ty::{self, TyCtxt};
 use rustc_mir_dataflow::move_paths::MoveData;
 use rustc_mir_dataflow::points::DenseLocationMap;
 use rustc_session::config::MirIncludeSpans;
-use rustc_span::sym;
 use tracing::{debug, instrument};
 
 use crate::borrow_set::BorrowSet;
@@ -295,7 +296,7 @@ pub(super) fn dump_annotation<'tcx, 'infcx>(
 ) {
     let tcx = infcx.tcx;
     let base_def_id = tcx.typeck_root_def_id(body.source.def_id());
-    if !tcx.has_attr(base_def_id, sym::rustc_regions) {
+    if !find_attr!(tcx.get_all_attrs(base_def_id), AttributeKind::RustcRegions) {
         return;
     }
 

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -1198,6 +1198,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_reallocator]`
     RustcReallocator,
 
+    /// Represents `#[rustc_regions]`
+    RustcRegions,
+
     /// Represents `#[rustc_scalable_vector(N)]`
     RustcScalableVector {
         /// The base multiple of lanes that are in a scalable vector, if provided. `element_count`

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -144,6 +144,7 @@ impl AttributeKind {
             RustcPreserveUbChecks => No,
             RustcPubTransparent(..) => Yes,
             RustcReallocator => No,
+            RustcRegions => No,
             RustcScalableVector { .. } => Yes,
             RustcShouldNotBeCalledOnConstItems(..) => Yes,
             RustcSimdMonomorphizeLaneLimit(..) => Yes, // Affects layout computation, which needs to work cross-crate

compiler/rustc_passes/src/check_attr.rs

@@ -335,6 +335,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcPassIndirectlyInNonRusticAbis(..)
                     | AttributeKind::RustcPreserveUbChecks
                     | AttributeKind::RustcReallocator
+                    | AttributeKind::RustcRegions
                     | AttributeKind::RustcScalableVector { .. }
                     | AttributeKind::RustcShouldNotBeCalledOnConstItems(..)
                     | AttributeKind::RustcSimdMonomorphizeLaneLimit(..)
@@ -401,7 +402,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::rustc_never_type_options
                             | sym::rustc_autodiff
                             | sym::rustc_capture_analysis
-                            | sym::rustc_regions
                             | sym::rustc_strict_coherence
                             | sym::rustc_mir
                             | sym::rustc_outlives