Rollup of 10 pull requests

.github/ISSUE_TEMPLATE/library_tracking_issue.md

@@ -2,7 +2,7 @@
 name: Library Tracking Issue
 about: A tracking issue for an unstable library feature.
 title: Tracking Issue for XXX
-labels: C-tracking-issue, T-libs-api
+labels: C-tracking-issue, T-libs-api, S-tracking-unimplemented
 ---
 <!--
 Thank you for creating a tracking issue!
@@ -49,6 +49,8 @@ For larger features, more steps might be involved.
 If the feature is changed later, please add those PRs here as well.
 -->
 
+(Remember to update the `S-tracking-*` label when checking boxes.)
+
 - [ ] Implementation: #...
 - [ ] Final comment period (FCP)[^1]
 - [ ] Stabilization PR

Cargo.lock

@@ -718,7 +718,6 @@ name = "compiletest"
 version = "0.0.0"
 dependencies = [
  "anstyle-svg",
- "anyhow",
  "build_helper",
  "colored",
  "diff",

compiler/rustc_errors/src/diagnostic.rs

@@ -647,9 +647,9 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     #[rustc_lint_diagnostics]
     pub fn note_expected_found(
         &mut self,
-        expected_label: &dyn fmt::Display,
+        expected_label: &str,
         expected: DiagStyledString,
-        found_label: &dyn fmt::Display,
+        found_label: &str,
         found: DiagStyledString,
     ) -> &mut Self {
         self.note_expected_found_extra(
@@ -665,9 +665,9 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     #[rustc_lint_diagnostics]
     pub fn note_expected_found_extra(
         &mut self,
-        expected_label: &dyn fmt::Display,
+        expected_label: &str,
         expected: DiagStyledString,
-        found_label: &dyn fmt::Display,
+        found_label: &str,
         found: DiagStyledString,
         expected_extra: DiagStyledString,
         found_extra: DiagStyledString,

compiler/rustc_hir_analysis/src/collect.rs

@@ -14,6 +14,7 @@
 //! At present, however, we do run collection across all items in the
 //! crate as a kind of pass. This should eventually be factored away.
 
+use std::assert_matches::assert_matches;
 use std::cell::Cell;
 use std::iter;
 use std::ops::Bound;
@@ -1344,7 +1345,8 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_, ty::PolyFn
             compute_sig_of_foreign_fn_decl(tcx, def_id, sig.decl, abi, sig.header.safety())
         }
 
-        Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor().is_some() => {
+        Ctor(data) => {
+            assert_matches!(data.ctor(), Some(_));
             let adt_def_id = tcx.hir_get_parent_item(hir_id).def_id.to_def_id();
             let ty = tcx.type_of(adt_def_id).instantiate_identity();
             let inputs = data.fields().iter().map(|f| tcx.type_of(f.def_id).instantiate_identity());

compiler/rustc_hir_analysis/src/variance/mod.rs

@@ -44,13 +44,13 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
         return &[];
     }
 
-    match tcx.def_kind(item_def_id) {
+    let kind = tcx.def_kind(item_def_id);
+    match kind {
         DefKind::Fn
         | DefKind::AssocFn
         | DefKind::Enum
         | DefKind::Struct
         | DefKind::Union
-        | DefKind::Variant
         | DefKind::Ctor(..) => {
             // These are inferred.
             let crate_map = tcx.crate_variances(());
@@ -89,7 +89,11 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
     }
 
     // Variance not relevant.
-    span_bug!(tcx.def_span(item_def_id), "asked to compute variance for wrong kind of item");
+    span_bug!(
+        tcx.def_span(item_def_id),
+        "asked to compute variance for {}",
+        kind.descr(item_def_id.to_def_id())
+    );
 }
 
 #[derive(Debug, Copy, Clone)]

compiler/rustc_lint/src/lints.rs

@@ -513,7 +513,7 @@ impl Subdiagnostic for BuiltinClashingExternSub<'_> {
         expected_str.push(self.expected.fn_sig(self.tcx).to_string(), false);
         let mut found_str = DiagStyledString::new();
         found_str.push(self.found.fn_sig(self.tcx).to_string(), true);
-        diag.note_expected_found(&"", expected_str, &"", found_str);
+        diag.note_expected_found("", expected_str, "", found_str);
     }
 }
 

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1099,7 +1099,6 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
         DefKind::Struct
         | DefKind::Union
         | DefKind::Enum
-        | DefKind::Variant
         | DefKind::OpaqueTy
         | DefKind::Fn
         | DefKind::Ctor(..)
@@ -1109,6 +1108,7 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
             matches!(tcx.opt_rpitit_info(def_id), Some(ty::ImplTraitInTraitData::Trait { .. }))
         }
         DefKind::Mod
+        | DefKind::Variant
         | DefKind::Field
         | DefKind::AssocConst
         | DefKind::TyParam

compiler/rustc_trait_selection/src/error_reporting/infer/region.rs

@@ -967,7 +967,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 format!("...so that the {}", sup_trace.cause.as_requirement_str()),
             );
 
-            err.note_expected_found(&"", sup_expected, &"", sup_found);
+            err.note_expected_found("", sup_expected, "", sup_found);
             return if sub_region.is_error() | sup_region.is_error() {
                 err.delay_as_bug()
             } else {

compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

@@ -2,6 +2,7 @@ use core::ops::ControlFlow;
 use std::borrow::Cow;
 use std::path::PathBuf;
 
+use rustc_abi::ExternAbi;
 use rustc_ast::TraitObjectSyntax;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::unord::UnordSet;
@@ -2799,32 +2800,57 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         }
 
         // Note any argument mismatches
-        let given_ty = params.skip_binder();
+        let ty::Tuple(given) = *params.skip_binder().kind() else {
+            return;
+        };
+
         let expected_ty = trait_pred.skip_binder().trait_ref.args.type_at(1);
-        if let ty::Tuple(given) = given_ty.kind()
-            && let ty::Tuple(expected) = expected_ty.kind()
-        {
-            if expected.len() != given.len() {
-                // Note number of types that were expected and given
-                err.note(
-                    format!(
-                        "expected a closure taking {} argument{}, but one taking {} argument{} was given",
-                        given.len(),
-                        pluralize!(given.len()),
-                        expected.len(),
-                        pluralize!(expected.len()),
-                    )
-                );
-            } else if !self.same_type_modulo_infer(given_ty, expected_ty) {
-                // Print type mismatch
-                let (expected_args, given_args) = self.cmp(given_ty, expected_ty);
-                err.note_expected_found(
-                    &"a closure with arguments",
-                    expected_args,
-                    &"a closure with arguments",
-                    given_args,
-                );
-            }
+        let ty::Tuple(expected) = *expected_ty.kind() else {
+            return;
+        };
+
+        if expected.len() != given.len() {
+            // Note number of types that were expected and given
+            err.note(format!(
+                "expected a closure taking {} argument{}, but one taking {} argument{} was given",
+                given.len(),
+                pluralize!(given.len()),
+                expected.len(),
+                pluralize!(expected.len()),
+            ));
+            return;
+        }
+
+        let given_ty = Ty::new_fn_ptr(
+            self.tcx,
+            params.rebind(self.tcx.mk_fn_sig(
+                given,
+                self.tcx.types.unit,
+                false,
+                hir::Safety::Safe,
+                ExternAbi::Rust,
+            )),
+        );
+        let expected_ty = Ty::new_fn_ptr(
+            self.tcx,
+            trait_pred.rebind(self.tcx.mk_fn_sig(
+                expected,
+                self.tcx.types.unit,
+                false,
+                hir::Safety::Safe,
+                ExternAbi::Rust,
+            )),
+        );
+
+        if !self.same_type_modulo_infer(given_ty, expected_ty) {
+            // Print type mismatch
+            let (expected_args, given_args) = self.cmp(expected_ty, given_ty);
+            err.note_expected_found(
+                "a closure with signature",
+                expected_args,
+                "a closure with signature",
+                given_args,
+            );
         }
     }
 

compiler/rustc_trait_selection/src/errors.rs

@@ -415,7 +415,7 @@ impl Subdiagnostic for RegionOriginNote<'_> {
                 label_or_note(span, fluent::trait_selection_subtype);
                 diag.arg("requirement", requirement);
 
-                diag.note_expected_found(&"", expected, &"", found);
+                diag.note_expected_found("", expected, "", found);
             }
             RegionOriginNote::WithRequirement { span, requirement, expected_found: None } => {
                 // FIXME: this really should be handled at some earlier stage. Our

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -317,7 +317,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     obligation.cause.clone(),
                     obligation.recursion_depth + 1,
                     obligation.param_env,
-                    obligation.predicate.rebind(trait_ref),
+                    trait_ref,
                 )
             };
 
@@ -343,7 +343,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     obligation.cause.clone(),
                     obligation.recursion_depth + 1,
                     obligation.param_env,
-                    obligation.predicate.rebind(outlives),
+                    outlives,
                 )
             };
 
@@ -404,7 +404,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             }
         }
 
-        let predicate = obligation.predicate.skip_binder();
+        let predicate = self.infcx.enter_forall_and_leak_universe(obligation.predicate);
 
         let mut assume = predicate.trait_ref.args.const_at(2);
         // FIXME(mgca): We should shallowly normalize this.

compiler/rustc_ty_utils/src/implied_bounds.rs

@@ -4,9 +4,9 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
-use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt, fold_regions};
+use rustc_middle::{bug, span_bug};
 use rustc_span::Span;
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -21,7 +21,8 @@ pub(crate) fn provide(providers: &mut Providers) {
 }
 
 fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'tcx>, Span)] {
-    match tcx.def_kind(def_id) {
+    let kind = tcx.def_kind(def_id);
+    match kind {
         DefKind::Fn => {
             let sig = tcx.fn_sig(def_id).instantiate_identity();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), sig);
@@ -121,32 +122,38 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
             }
         }
         DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.local_parent(def_id)),
-        DefKind::OpaqueTy => bug!("implied bounds are not defined for opaques"),
-        DefKind::Mod
+        DefKind::Static { .. }
+        | DefKind::Const
+        | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::Struct
         | DefKind::Union
         | DefKind::Enum
-        | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
-        | DefKind::ForeignTy
         | DefKind::TraitAlias
+        | DefKind::TyAlias => ty::List::empty(),
+        DefKind::OpaqueTy
+        | DefKind::Mod
+        | DefKind::Variant
+        | DefKind::ForeignTy
         | DefKind::TyParam
-        | DefKind::Const
         | DefKind::ConstParam
-        | DefKind::Static { .. }
         | DefKind::Ctor(_, _)
         | DefKind::Macro(_)
         | DefKind::ExternCrate
         | DefKind::Use
         | DefKind::ForeignMod
-        | DefKind::AnonConst
-        | DefKind::InlineConst
         | DefKind::Field
         | DefKind::LifetimeParam
         | DefKind::GlobalAsm
         | DefKind::Closure
-        | DefKind::SyntheticCoroutineBody => ty::List::empty(),
+        | DefKind::SyntheticCoroutineBody => {
+            span_bug!(
+                tcx.def_span(def_id),
+                "`assumed_wf_types` not defined for {} `{def_id:?}`",
+                kind.descr(def_id.to_def_id())
+            );
+        }
     }
 }
 

compiler/rustc_ty_utils/src/opaque_types.rs

@@ -3,10 +3,10 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit;
 use rustc_hir::intravisit::Visitor;
-use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::util::{CheckRegions, NotUniqueParam};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::{bug, span_bug};
 use rustc_span::Span;
 use tracing::{instrument, trace};
 
@@ -320,9 +320,12 @@ fn opaque_types_defined_by<'tcx>(
         | DefKind::AnonConst => {
             collector.collect_taits_declared_in_body();
         }
+        // Closures and coroutines are type checked with their parent
+        DefKind::Closure | DefKind::InlineConst => {
+            collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
+        }
+        DefKind::AssocTy | DefKind::TyAlias | DefKind::GlobalAsm => {}
         DefKind::OpaqueTy
-        | DefKind::TyAlias
-        | DefKind::AssocTy
         | DefKind::Mod
         | DefKind::Struct
         | DefKind::Union
@@ -340,12 +343,13 @@ fn opaque_types_defined_by<'tcx>(
         | DefKind::ForeignMod
         | DefKind::Field
         | DefKind::LifetimeParam
-        | DefKind::GlobalAsm
         | DefKind::Impl { .. }
-        | DefKind::SyntheticCoroutineBody => {}
-        // Closures and coroutines are type checked with their parent
-        DefKind::Closure | DefKind::InlineConst => {
-            collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
+        | DefKind::SyntheticCoroutineBody => {
+            span_bug!(
+                tcx.def_span(item),
+                "`opaque_types_defined_by` not defined for {} `{item:?}`",
+                kind.descr(item.to_def_id())
+            );
         }
     }
     tcx.mk_local_def_ids(&collector.opaques)

compiler/rustc_ty_utils/src/sig_types.rs

@@ -116,7 +116,7 @@ pub fn walk_types<'tcx, V: SpannedTypeVisitor<'tcx>>(
                 "{kind:?} has not seen any uses of `walk_types` yet, ping oli-obk if you'd like any help"
             )
         }
-        // These don't have any types.
+        // These don't have any types, but are visited during privacy checking.
         | DefKind::ExternCrate
         | DefKind::ForeignMod
         | DefKind::ForeignTy