Add a new mismatched-lifetime-syntaxes lint

compiler/rustc_ast_lowering/src/item.rs

@@ -5,7 +5,7 @@ use rustc_ast::*;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LocalDefId};
-use rustc_hir::{self as hir, HirId, IsAnonInPath, PredicateOrigin};
+use rustc_hir::{self as hir, HirId, LifetimeSource, PredicateOrigin};
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::ty::{ResolverAstLowering, TyCtxt};
 use rustc_span::edit_distance::find_best_match_for_name;
@@ -1861,7 +1861,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
             }
             GenericParamKind::Lifetime => {
                 let lt_id = self.next_node_id();
-                let lifetime = self.new_named_lifetime(id, lt_id, ident, IsAnonInPath::No);
+                let lifetime =
+                    self.new_named_lifetime(id, lt_id, ident, LifetimeSource::Other, ident.into());
                 hir::WherePredicateKind::RegionPredicate(hir::WhereRegionPredicate {
                     lifetime,
                     bounds,
@@ -1894,7 +1895,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
             }),
             WherePredicateKind::RegionPredicate(WhereRegionPredicate { lifetime, bounds }) => {
                 hir::WherePredicateKind::RegionPredicate(hir::WhereRegionPredicate {
-                    lifetime: self.lower_lifetime(lifetime),
+                    lifetime: self.lower_lifetime(
+                        lifetime,
+                        LifetimeSource::Other,
+                        lifetime.ident.into(),
+                    ),
                     bounds: self.lower_param_bounds(
                         bounds,
                         ImplTraitContext::Disallowed(ImplTraitPosition::Bound),

compiler/rustc_ast_lowering/src/lib.rs

@@ -55,8 +55,8 @@ use rustc_errors::{DiagArgFromDisplay, DiagCtxtHandle, StashKey};
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE, LocalDefId};
 use rustc_hir::{
-    self as hir, ConstArg, GenericArg, HirId, IsAnonInPath, ItemLocalMap, LangItem, ParamName,
-    TraitCandidate,
+    self as hir, ConstArg, GenericArg, HirId, ItemLocalMap, LangItem, LifetimeSource,
+    LifetimeSyntax, ParamName, TraitCandidate,
 };
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_macros::extension;
@@ -1080,7 +1080,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         itctx: ImplTraitContext,
     ) -> hir::GenericArg<'hir> {
         match arg {
-            ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(lt)),
+            ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(
+                lt,
+                LifetimeSource::Path { with_angle_brackets: true },
+                lt.ident.into(),
+            )),
             ast::GenericArg::Type(ty) => {
                 // We cannot just match on `TyKind::Infer` as `(_)` is represented as
                 // `TyKind::Paren(TyKind::Infer)` and should also be lowered to `GenericArg::Infer`
@@ -1199,35 +1203,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             TyKind::Slice(ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)),
             TyKind::Ptr(mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)),
             TyKind::Ref(region, mt) => {
-                let region = region.unwrap_or_else(|| {
-                    let id = if let Some(LifetimeRes::ElidedAnchor { start, end }) =
-                        self.resolver.get_lifetime_res(t.id)
-                    {
-                        debug_assert_eq!(start.plus(1), end);
-                        start
-                    } else {
-                        self.next_node_id()
-                    };
-                    let span = self.tcx.sess.source_map().start_point(t.span).shrink_to_hi();
-                    Lifetime { ident: Ident::new(kw::UnderscoreLifetime, span), id }
-                });
-                let lifetime = self.lower_lifetime(&region);
+                let lifetime = self.lower_ty_direct_lifetime(t, *region);
                 hir::TyKind::Ref(lifetime, self.lower_mt(mt, itctx))
             }
             TyKind::PinnedRef(region, mt) => {
-                let region = region.unwrap_or_else(|| {
-                    let id = if let Some(LifetimeRes::ElidedAnchor { start, end }) =
-                        self.resolver.get_lifetime_res(t.id)
-                    {
-                        debug_assert_eq!(start.plus(1), end);
-                        start
-                    } else {
-                        self.next_node_id()
-                    };
-                    let span = self.tcx.sess.source_map().start_point(t.span).shrink_to_hi();
-                    Lifetime { ident: Ident::new(kw::UnderscoreLifetime, span), id }
-                });
-                let lifetime = self.lower_lifetime(&region);
+                let lifetime = self.lower_ty_direct_lifetime(t, *region);
                 let kind = hir::TyKind::Ref(lifetime, self.lower_mt(mt, itctx));
                 let span = self.lower_span(t.span);
                 let arg = hir::Ty { kind, span, hir_id: self.next_id() };
@@ -1303,7 +1283,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             }
                             GenericBound::Outlives(lifetime) => {
                                 if lifetime_bound.is_none() {
-                                    lifetime_bound = Some(this.lower_lifetime(lifetime));
+                                    lifetime_bound = Some(this.lower_lifetime(
+                                        lifetime,
+                                        LifetimeSource::Other,
+                                        lifetime.ident.into(),
+                                    ));
                                 }
                                 None
                             }
@@ -1394,6 +1378,31 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         hir::Ty { kind, span: self.lower_span(t.span), hir_id: self.lower_node_id(t.id) }
     }
 
+    fn lower_ty_direct_lifetime(
+        &mut self,
+        t: &Ty,
+        region: Option<Lifetime>,
+    ) -> &'hir hir::Lifetime {
+        let (region, syntax) = match region {
+            Some(region) => (region, region.ident.into()),
+
+            None => {
+                let id = if let Some(LifetimeRes::ElidedAnchor { start, end }) =
+                    self.resolver.get_lifetime_res(t.id)
+                {
+                    debug_assert_eq!(start.plus(1), end);
+                    start
+                } else {
+                    self.next_node_id()
+                };
+                let span = self.tcx.sess.source_map().start_point(t.span).shrink_to_hi();
+                let region = Lifetime { ident: Ident::new(kw::UnderscoreLifetime, span), id };
+                (region, LifetimeSyntax::Hidden)
+            }
+        };
+        self.lower_lifetime(&region, LifetimeSource::Reference, syntax)
+    }
+
     /// Lowers a `ReturnPositionOpaqueTy` (`-> impl Trait`) or a `TypeAliasesOpaqueTy` (`type F =
     /// impl Trait`): this creates the associated Opaque Type (TAIT) definition and then returns a
     /// HIR type that references the TAIT.
@@ -1475,9 +1484,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         precise_capturing_args: &[PreciseCapturingArg],
     ) -> &'hir [hir::PreciseCapturingArg<'hir>] {
         self.arena.alloc_from_iter(precise_capturing_args.iter().map(|arg| match arg {
-            PreciseCapturingArg::Lifetime(lt) => {
-                hir::PreciseCapturingArg::Lifetime(self.lower_lifetime(lt))
-            }
+            PreciseCapturingArg::Lifetime(lt) => hir::PreciseCapturingArg::Lifetime(
+                self.lower_lifetime(lt, LifetimeSource::PreciseCapturing, lt.ident.into()),
+            ),
             PreciseCapturingArg::Arg(path, id) => {
                 let [segment] = path.segments.as_slice() else {
                     panic!();
@@ -1740,22 +1749,40 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     ) -> hir::GenericBound<'hir> {
         match tpb {
             GenericBound::Trait(p) => hir::GenericBound::Trait(self.lower_poly_trait_ref(p, itctx)),
-            GenericBound::Outlives(lifetime) => {
-                hir::GenericBound::Outlives(self.lower_lifetime(lifetime))
-            }
+            GenericBound::Outlives(lifetime) => hir::GenericBound::Outlives(self.lower_lifetime(
+                lifetime,
+                LifetimeSource::OutlivesBound,
+                lifetime.ident.into(),
+            )),
             GenericBound::Use(args, span) => hir::GenericBound::Use(
                 self.lower_precise_capturing_args(args),
                 self.lower_span(*span),
             ),
         }
     }
 
-    fn lower_lifetime(&mut self, l: &Lifetime) -> &'hir hir::Lifetime {
-        self.new_named_lifetime(l.id, l.id, l.ident, IsAnonInPath::No)
+    fn lower_lifetime(
+        &mut self,
+        l: &Lifetime,
+        source: LifetimeSource,
+        syntax: LifetimeSyntax,
+    ) -> &'hir hir::Lifetime {
+        self.new_named_lifetime(l.id, l.id, l.ident, source, syntax)
     }
 
-    fn lower_lifetime_anon_in_path(&mut self, id: NodeId, span: Span) -> &'hir hir::Lifetime {
-        self.new_named_lifetime(id, id, Ident::new(kw::UnderscoreLifetime, span), IsAnonInPath::Yes)
+    fn lower_lifetime_hidden_in_path(
+        &mut self,
+        id: NodeId,
+        span: Span,
+        with_angle_brackets: bool,
+    ) -> &'hir hir::Lifetime {
+        self.new_named_lifetime(
+            id,
+            id,
+            Ident::new(kw::UnderscoreLifetime, span),
+            LifetimeSource::Path { with_angle_brackets },
+            LifetimeSyntax::Hidden,
+        )
     }
 
     #[instrument(level = "debug", skip(self))]
@@ -1764,7 +1791,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         id: NodeId,
         new_id: NodeId,
         ident: Ident,
-        is_anon_in_path: IsAnonInPath,
+        source: LifetimeSource,
+        syntax: LifetimeSyntax,
     ) -> &'hir hir::Lifetime {
         debug_assert_ne!(ident.name, kw::Empty);
         let res = self.resolver.get_lifetime_res(id).unwrap_or(LifetimeRes::Error);
@@ -1789,17 +1817,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             }
         };
 
-        #[cfg(debug_assertions)]
-        if is_anon_in_path == IsAnonInPath::Yes {
-            debug_assert_eq!(ident.name, kw::UnderscoreLifetime);
-        }
-
         debug!(?res);
         self.arena.alloc(hir::Lifetime::new(
             self.lower_node_id(new_id),
             self.lower_ident(ident),
             res,
-            is_anon_in_path,
+            source,
+            syntax,
         ))
     }
 
@@ -2389,7 +2413,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             self.next_id(),
             Ident::new(kw::UnderscoreLifetime, self.lower_span(span)),
             hir::LifetimeName::ImplicitObjectLifetimeDefault,
-            IsAnonInPath::No,
+            LifetimeSource::Other,
+            LifetimeSyntax::Hidden,
         );
         debug!("elided_dyn_bound: r={:?}", r);
         self.arena.alloc(r)

compiler/rustc_ast_lowering/src/path.rs

@@ -1,10 +1,9 @@
 use std::sync::Arc;
 
 use rustc_ast::{self as ast, *};
-use rustc_hir as hir;
-use rustc_hir::GenericArg;
 use rustc_hir::def::{DefKind, PartialRes, Res};
 use rustc_hir::def_id::DefId;
+use rustc_hir::{self as hir, GenericArg};
 use rustc_middle::span_bug;
 use rustc_session::parse::add_feature_diagnostics;
 use rustc_span::{BytePos, DUMMY_SP, DesugaringKind, Ident, Span, Symbol, sym};
@@ -433,24 +432,29 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         // Note: these spans are used for diagnostics when they can't be inferred.
         // See rustc_resolve::late::lifetimes::LifetimeContext::add_missing_lifetime_specifiers_label
-        let elided_lifetime_span = if generic_args.span.is_empty() {
+        let (elided_lifetime_span, with_angle_brackets) = if generic_args.span.is_empty() {
             // If there are no brackets, use the identifier span.
             // HACK: we use find_ancestor_inside to properly suggest elided spans in paths
             // originating from macros, since the segment's span might be from a macro arg.
-            segment_ident_span.find_ancestor_inside(path_span).unwrap_or(path_span)
+            (segment_ident_span.find_ancestor_inside(path_span).unwrap_or(path_span), false)
         } else if generic_args.is_empty() {
             // If there are brackets, but not generic arguments, then use the opening bracket
-            generic_args.span.with_hi(generic_args.span.lo() + BytePos(1))
+            (generic_args.span.with_hi(generic_args.span.lo() + BytePos(1)), true)
         } else {
             // Else use an empty span right after the opening bracket.
-            generic_args.span.with_lo(generic_args.span.lo() + BytePos(1)).shrink_to_lo()
+            (generic_args.span.with_lo(generic_args.span.lo() + BytePos(1)).shrink_to_lo(), true)
         };
 
         generic_args.args.insert_many(
             0,
             (start.as_u32()..end.as_u32()).map(|i| {
                 let id = NodeId::from_u32(i);
-                let l = self.lower_lifetime_anon_in_path(id, elided_lifetime_span);
+
+                let l = self.lower_lifetime_hidden_in_path(
+                    id,
+                    elided_lifetime_span,
+                    with_angle_brackets,
+                );
                 GenericArg::Lifetime(l)
             }),
         );

compiler/rustc_ast_passes/src/errors.rs

@@ -2,7 +2,7 @@
 
 use rustc_ast::ParamKindOrd;
 use rustc_errors::codes::*;
-use rustc_errors::{Applicability, Diag, EmissionGuarantee, SubdiagMessageOp, Subdiagnostic};
+use rustc_errors::{Applicability, Diag, EmissionGuarantee, Subdiagnostic};
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::{Ident, Span, Symbol};
 
@@ -394,11 +394,7 @@ pub(crate) struct EmptyLabelManySpans(pub Vec<Span>);
 
 // The derive for `Vec<Span>` does multiple calls to `span_label`, adding commas between each
 impl Subdiagnostic for EmptyLabelManySpans {
-    fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
-        self,
-        diag: &mut Diag<'_, G>,
-        _: &F,
-    ) {
+    fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
         diag.span_labels(self.0, "");
     }
 }
@@ -749,11 +745,7 @@ pub(crate) struct StableFeature {
 }
 
 impl Subdiagnostic for StableFeature {
-    fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
-        self,
-        diag: &mut Diag<'_, G>,
-        _: &F,
-    ) {
+    fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
         diag.arg("name", self.name);
         diag.arg("since", self.since);
         diag.help(fluent::ast_passes_stable_since);

compiler/rustc_builtin_macros/src/errors.rs

@@ -1,7 +1,7 @@
 use rustc_errors::codes::*;
 use rustc_errors::{
     Diag, DiagCtxtHandle, Diagnostic, EmissionGuarantee, Level, MultiSpan, SingleLabelManySpans,
-    SubdiagMessageOp, Subdiagnostic,
+    Subdiagnostic,
 };
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::{Ident, Span, Symbol};
@@ -691,13 +691,9 @@ pub(crate) struct FormatUnusedArg {
 // Allow the singular form to be a subdiagnostic of the multiple-unused
 // form of diagnostic.
 impl Subdiagnostic for FormatUnusedArg {
-    fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
-        self,
-        diag: &mut Diag<'_, G>,
-        f: &F,
-    ) {
+    fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
         diag.arg("named", self.named);
-        let msg = f(diag, crate::fluent_generated::builtin_macros_format_unused_arg.into());
+        let msg = diag.eagerly_translate(crate::fluent_generated::builtin_macros_format_unused_arg);
         diag.span_label(self.span, msg);
     }
 }

compiler/rustc_const_eval/src/errors.rs

@@ -6,7 +6,7 @@ use rustc_abi::WrappingRange;
 use rustc_errors::codes::*;
 use rustc_errors::{
     Diag, DiagArgValue, DiagCtxtHandle, DiagMessage, Diagnostic, EmissionGuarantee, Level,
-    MultiSpan, SubdiagMessageOp, Subdiagnostic,
+    MultiSpan, Subdiagnostic,
 };
 use rustc_hir::ConstContext;
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
@@ -290,19 +290,15 @@ pub struct FrameNote {
 }
 
 impl Subdiagnostic for FrameNote {
-    fn add_to_diag_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
-        self,
-        diag: &mut Diag<'_, G>,
-        f: &F,
-    ) {
+    fn add_to_diag<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
         diag.arg("times", self.times);
         diag.arg("where_", self.where_);
         diag.arg("instance", self.instance);
         let mut span: MultiSpan = self.span.into();
         if self.has_label && !self.span.is_dummy() {
             span.push_span_label(self.span, fluent::const_eval_frame_note_last);
         }
-        let msg = f(diag, fluent::const_eval_frame_note.into());
+        let msg = diag.eagerly_translate(fluent::const_eval_frame_note);
         diag.span_note(span, msg);
     }
 }