about summary refs log tree commit diff
diff options
context:
space:
mode:
-rw-r--r--compiler/rustc_ast_lowering/src/expr.rs2
-rw-r--r--compiler/rustc_codegen_gcc/src/asm.rs4
-rw-r--r--compiler/rustc_codegen_llvm/src/asm.rs7
-rw-r--r--compiler/rustc_codegen_ssa/src/back/link.rs19
-rw-r--r--compiler/rustc_hir/src/hir.rs4
-rw-r--r--compiler/rustc_hir_analysis/messages.ftl3
-rw-r--r--compiler/rustc_hir_analysis/src/astconv/bounds.rs29
-rw-r--r--compiler/rustc_hir_analysis/src/check/check.rs6
-rw-r--r--compiler/rustc_hir_analysis/src/check/wfcheck.rs4
-rw-r--r--compiler/rustc_hir_analysis/src/collect.rs4
-rw-r--r--compiler/rustc_hir_analysis/src/errors.rs9
-rw-r--r--compiler/rustc_hir_analysis/src/impl_wf_check.rs4
-rw-r--r--compiler/rustc_hir_typeck/src/_match.rs12
-rw-r--r--compiler/rustc_hir_typeck/src/callee.rs1
-rw-r--r--compiler/rustc_hir_typeck/src/coercion.rs9
-rw-r--r--compiler/rustc_hir_typeck/src/demand.rs24
-rw-r--r--compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs5
-rw-r--r--compiler/rustc_infer/src/infer/error_reporting/mod.rs91
-rw-r--r--compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs2
-rw-r--r--compiler/rustc_lint/src/late.rs6
-rw-r--r--compiler/rustc_lint/src/lib.rs4
-rw-r--r--compiler/rustc_lint_defs/src/builtin.rs39
-rw-r--r--compiler/rustc_middle/src/dep_graph/dep_node.rs52
-rw-r--r--compiler/rustc_middle/src/hir/map/mod.rs28
-rw-r--r--compiler/rustc_middle/src/hir/mod.rs10
-rw-r--r--compiler/rustc_middle/src/lib.rs1
-rw-r--r--compiler/rustc_middle/src/query/erase.rs1
-rw-r--r--compiler/rustc_middle/src/query/keys.rs37
-rw-r--r--compiler/rustc_middle/src/query/mod.rs31
-rw-r--r--compiler/rustc_middle/src/query/plumbing.rs22
-rw-r--r--compiler/rustc_middle/src/thir.rs1
-rw-r--r--compiler/rustc_middle/src/thir/visit.rs2
-rw-r--r--compiler/rustc_middle/src/traits/mod.rs3
-rw-r--r--compiler/rustc_middle/src/ty/mod.rs6
-rw-r--r--compiler/rustc_middle/src/ty/print/mod.rs3
-rw-r--r--compiler/rustc_middle/src/ty/print/pretty.rs8
-rw-r--r--compiler/rustc_mir_build/src/build/custom/parse/instruction.rs2
-rw-r--r--compiler/rustc_mir_build/src/build/expr/into.rs2
-rw-r--r--compiler/rustc_mir_build/src/thir/cx/expr.rs1
-rw-r--r--compiler/rustc_mir_build/src/thir/pattern/check_match.rs8
-rw-r--r--compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs7
-rw-r--r--compiler/rustc_mir_build/src/thir/print.rs2
-rw-r--r--compiler/rustc_passes/src/check_attr.rs6
-rw-r--r--compiler/rustc_passes/src/check_const.rs6
-rw-r--r--compiler/rustc_passes/src/dead.rs6
-rw-r--r--compiler/rustc_passes/src/loops.rs4
-rw-r--r--compiler/rustc_passes/src/naked_functions.rs4
-rw-r--r--compiler/rustc_passes/src/stability.rs4
-rw-r--r--compiler/rustc_privacy/src/lib.rs60
-rw-r--r--compiler/rustc_smir/src/lib.rs1
-rw-r--r--compiler/rustc_smir/src/stable_mir/mod.rs16
-rw-r--r--compiler/rustc_span/src/def_id.rs95
-rw-r--r--compiler/rustc_target/src/spec/loongarch64_unknown_none.rs3
-rw-r--r--compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs3
-rw-r--r--compiler/rustc_target/src/spec/mod.rs2
-rw-r--r--compiler/rustc_trait_selection/src/solve/assembly/mod.rs48
-rw-r--r--compiler/rustc_trait_selection/src/solve/project_goals.rs31
-rw-r--r--compiler/rustc_trait_selection/src/solve/trait_goals.rs116
-rw-r--r--compiler/rustc_trait_selection/src/traits/coherence.rs141
-rw-r--r--compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs2
-rw-r--r--compiler/rustc_trait_selection/src/traits/select/mod.rs46
-rw-r--r--library/alloc/tests/str.rs7
-rw-r--r--library/core/src/cmp.rs16
-rw-r--r--library/core/src/error.rs10
-rw-r--r--library/core/src/ffi/c_str.rs8
-rw-r--r--library/core/src/panicking.rs14
-rw-r--r--library/core/src/str/mod.rs7
-rw-r--r--library/proc_macro/src/lib.rs1
-rw-r--r--library/std/src/ffi/os_str.rs8
-rw-r--r--library/std/src/path.rs16
-rw-r--r--library/std/src/process.rs11
-rw-r--r--library/std/src/sys/wasi/fd.rs10
-rw-r--r--library/std/src/sys/wasi/thread.rs6
-rw-r--r--library/std/src/sys_common/wtf8.rs2
-rw-r--r--library/std/src/thread/local.rs27
-rw-r--r--src/doc/rustc/src/codegen-options/index.md2
-rw-r--r--src/doc/rustc/src/platform-support/aarch64-unknown-teeos.md2
-rw-r--r--src/doc/rustc/src/platform-support/loongarch-linux.md2
-rw-r--r--src/doc/rustc/src/platform-support/netbsd.md2
-rw-r--r--src/doc/rustc/src/platform-support/x86_64h-apple-darwin.md4
-rw-r--r--src/doc/unstable-book/src/compiler-flags/path-options.md2
-rw-r--r--src/librustdoc/clean/inline.rs6
-rw-r--r--src/librustdoc/clean/mod.rs4
-rw-r--r--src/tools/clippy/clippy_lints/src/dereference.rs3
-rw-r--r--src/tools/clippy/clippy_lints/src/matches/mod.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/matches/try_err.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/methods/str_splitn.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/needless_question_mark.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/question_mark_used.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/redundant_closure_call.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/returns.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/unit_types/unit_arg.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/useless_conversion.rs2
-rw-r--r--src/tools/clippy/clippy_utils/src/check_proc_macro.rs2
-rw-r--r--src/tools/clippy/clippy_utils/src/lib.rs10
-rw-r--r--src/tools/clippy/clippy_utils/src/visitors.rs2
-rw-r--r--src/tools/clippy/tests/ui/if_same_then_else2.rs2
-rw-r--r--src/tools/clippy/tests/ui/if_same_then_else2.stderr21
-rw-r--r--src/tools/miri/src/lib.rs1
-rw-r--r--tests/rustdoc-gui/unsafe-fn.goml6
-rw-r--r--tests/ui/associated-type-bounds/consts.rs10
-rw-r--r--tests/ui/associated-type-bounds/consts.stderr10
-rw-r--r--tests/ui/coherence/warn-when-cycle-is-error-in-coherence.rs35
-rw-r--r--tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr23
-rw-r--r--tests/ui/did_you_mean/compatible-variants.stderr2
-rw-r--r--tests/ui/generic-associated-types/issue-102114.current.stderr (renamed from tests/ui/generic-associated-types/issue-102114.stderr)2
-rw-r--r--tests/ui/generic-associated-types/issue-102114.next.stderr12
-rw-r--r--tests/ui/generic-associated-types/issue-102114.rs3
-rw-r--r--tests/ui/generic-associated-types/issue-86218.rs1
-rw-r--r--tests/ui/generic-associated-types/issue-90014-tait.rs1
-rw-r--r--tests/ui/generic-associated-types/issue-90014-tait.stderr8
-rw-r--r--tests/ui/higher-ranked/subtype/placeholder-pattern-fail.stderr4
-rw-r--r--tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-fn.stderr4
-rw-r--r--tests/ui/inline-const/pat-match-fndef.rs13
-rw-r--r--tests/ui/inline-const/pat-match-fndef.stderr17
-rw-r--r--tests/ui/internal/internal-unstable.rs2
-rw-r--r--tests/ui/internal/internal-unstable.stderr10
-rw-r--r--tests/ui/issues/issue-51632-try-desugar-incompatible-types.stderr2
-rw-r--r--tests/ui/lint/unknown-lints/allow-in-other-module.rs26
-rw-r--r--tests/ui/lint/unknown-lints/other.rs10
-rw-r--r--tests/ui/macros/assert-eq-macro-msg.rs6
-rw-r--r--tests/ui/macros/assert-eq-macro-panic.rs6
-rw-r--r--tests/ui/macros/assert-matches-macro-msg.rs6
-rw-r--r--tests/ui/macros/assert-ne-macro-msg.rs6
-rw-r--r--tests/ui/macros/assert-ne-macro-panic.rs6
-rw-r--r--tests/ui/match/non-first-arm-doesnt-match-expected-return-type.rs21
-rw-r--r--tests/ui/match/non-first-arm-doesnt-match-expected-return-type.stderr12
-rw-r--r--tests/ui/parser/issues/issue-70583-block-is-empty-2.rs8
-rw-r--r--tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr3
-rw-r--r--tests/ui/regions/higher-ranked-implied.stderr8
-rw-r--r--tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr4
-rw-r--r--tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr4
-rw-r--r--tests/ui/regions/regions-lifetime-bounds-on-fns.stderr4
-rw-r--r--tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs2
-rw-r--r--tests/ui/std/slice-from-array-issue-113238.rs9
-rw-r--r--tests/ui/suggestions/issue-114701.rs15
-rw-r--r--tests/ui/suggestions/issue-114701.stderr15
-rw-r--r--tests/ui/suggestions/remove-question-symbol-with-paren.stderr3
-rw-r--r--tests/ui/test-attrs/test-panic-abort-nocapture.run.stderr12
-rw-r--r--tests/ui/test-attrs/test-panic-abort.run.stdout6
-rw-r--r--tests/ui/traits/issue-105231.rs2
-rw-r--r--tests/ui/traits/issue-105231.stderr8
-rw-r--r--tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.rs2
-rw-r--r--tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.stderr8
-rw-r--r--tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr (renamed from tests/ui/traits/trait-upcasting/type-checking-test-1.stderr)4
-rw-r--r--tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr9
-rw-r--r--tests/ui/traits/trait-upcasting/type-checking-test-1.rs5
-rw-r--r--tests/ui/unsized/issue-75899.rs2
-rw-r--r--tests/ui/where-clauses/where-clause-bounds-inconsistency.rs1
150 files changed, 1256 insertions, 479 deletions
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index b23cee14f75..7408b4fb0af 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1648,7 +1648,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         hir::ExprKind::Match(
             scrutinee,
             arena_vec![self; break_arm, continue_arm],
-            hir::MatchSource::TryDesugar,
+            hir::MatchSource::TryDesugar(scrutinee.hir_id),
         )
     }
 
diff --git a/compiler/rustc_codegen_gcc/src/asm.rs b/compiler/rustc_codegen_gcc/src/asm.rs
index 0482a85f5f3..905fdac92e9 100644
--- a/compiler/rustc_codegen_gcc/src/asm.rs
+++ b/compiler/rustc_codegen_gcc/src/asm.rs
@@ -107,7 +107,7 @@ enum ConstraintOrRegister {
 
 
 impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
-    fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], rust_operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, span: &[Span], _instance: Instance<'_>, _dest_catch_funclet: Option<(Self::BasicBlock, Self::BasicBlock, Option<&Self::Funclet>)>) {
+    fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], rust_operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, span: &[Span], instance: Instance<'_>, _dest_catch_funclet: Option<(Self::BasicBlock, Self::BasicBlock, Option<&Self::Funclet>)>) {
         if options.contains(InlineAsmOptions::MAY_UNWIND) {
             self.sess()
                 .create_err(UnwindingInlineAsm { span: span[0] })
@@ -173,7 +173,7 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                             let is_target_supported = reg.reg_class().supported_types(asm_arch).iter()
                                 .any(|&(_, feature)| {
                                     if let Some(feature) = feature {
-                                        self.tcx.sess.target_features.contains(&feature)
+                                        self.tcx.asm_target_features(instance.def_id()).contains(&feature)
                                     } else {
                                         true // Register class is unconditionally supported
                                     }
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index ca9fd76a997..1323261ae92 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -44,9 +44,10 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                     let is_target_supported = |reg_class: InlineAsmRegClass| {
                         for &(_, feature) in reg_class.supported_types(asm_arch) {
                             if let Some(feature) = feature {
-                                let codegen_fn_attrs = self.tcx.codegen_fn_attrs(instance.def_id());
-                                if self.tcx.sess.target_features.contains(&feature)
-                                    || codegen_fn_attrs.target_features.contains(&feature)
+                                if self
+                                    .tcx
+                                    .asm_target_features(instance.def_id())
+                                    .contains(&feature)
                                 {
                                     return true;
                                 }
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index bb65c3c81d9..a7ac728c59b 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -2991,25 +2991,10 @@ fn add_lld_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
         return;
     }
 
-    let self_contained_linker = sess.opts.cg.link_self_contained.linker();
-
-    // FIXME: some targets default to using `lld`, but users can only override the linker on the CLI
-    // and cannot yet select the precise linker flavor to opt out of that. See for example issue
-    // #113597 for the `thumbv6m-none-eabi` target: a driver is used, and its default linker
-    // conflicts with the target's flavor, causing unexpected arguments being passed.
-    //
-    // Until the new `LinkerFlavor`-like CLI options are stabilized, we only adopt MCP510's behavior
-    // if its dedicated unstable CLI flags are used, to keep the current sub-optimal stable
-    // behavior.
-    let using_mcp510 =
-        self_contained_linker || sess.opts.cg.linker_flavor.is_some_and(|f| f.is_unstable());
-    if !using_mcp510 && !unstable_use_lld {
-        return;
-    }
-
     // 1. Implement the "self-contained" part of this feature by adding rustc distribution
     //    directories to the tool's search path.
-    if self_contained_linker || unstable_use_lld {
+    let self_contained_linker = sess.opts.cg.link_self_contained.linker() || unstable_use_lld;
+    if self_contained_linker {
         for path in sess.get_tools_search_paths(false) {
             cmd.arg({
                 let mut arg = OsString::from("-B");
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 6340f1dcca1..0bfd62d68b2 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2148,7 +2148,7 @@ pub enum MatchSource {
     /// A desugared `for _ in _ { .. }` loop.
     ForLoopDesugar,
     /// A desugared `?` operator.
-    TryDesugar,
+    TryDesugar(HirId),
     /// A desugared `<expr>.await`.
     AwaitDesugar,
     /// A desugared `format_args!()`.
@@ -2162,7 +2162,7 @@ impl MatchSource {
         match self {
             Normal => "match",
             ForLoopDesugar => "for",
-            TryDesugar => "?",
+            TryDesugar(_) => "?",
             AwaitDesugar => ".await",
             FormatArgs => "format_args!()",
         }
diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
index 166760166c1..597cae6ff33 100644
--- a/compiler/rustc_hir_analysis/messages.ftl
+++ b/compiler/rustc_hir_analysis/messages.ftl
@@ -1,6 +1,9 @@
 hir_analysis_ambiguous_lifetime_bound =
     ambiguous lifetime bound, explicit lifetime bound required
 
+hir_analysis_assoc_bound_on_const = expected associated type, found {$descr}
+    .note = trait bounds not allowed on {$descr}
+
 hir_analysis_assoc_type_binding_not_allowed =
     associated type bindings are not allowed here
     .label = associated type not allowed here
diff --git a/compiler/rustc_hir_analysis/src/astconv/bounds.rs b/compiler/rustc_hir_analysis/src/astconv/bounds.rs
index 30145b1a185..ba152cd48de 100644
--- a/compiler/rustc_hir_analysis/src/astconv/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/bounds.rs
@@ -13,7 +13,7 @@ use crate::astconv::{
     AstConv, ConvertedBinding, ConvertedBindingKind, OnlySelfBounds, PredicateFilter,
 };
 use crate::bounds::Bounds;
-use crate::errors::{MultipleRelaxedDefaultBounds, ValueOfAssociatedStructAlreadySpecified};
+use crate::errors;
 
 impl<'tcx> dyn AstConv<'tcx> + '_ {
     /// Sets `implicitly_sized` to true on `Bounds` if necessary
@@ -35,7 +35,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                     if unbound.is_none() {
                         unbound = Some(&ptr.trait_ref);
                     } else {
-                        tcx.sess.emit_err(MultipleRelaxedDefaultBounds { span });
+                        tcx.sess.emit_err(errors::MultipleRelaxedDefaultBounds { span });
                     }
                 }
             }
@@ -326,7 +326,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             dup_bindings
                 .entry(assoc_item.def_id)
                 .and_modify(|prev_span| {
-                    tcx.sess.emit_err(ValueOfAssociatedStructAlreadySpecified {
+                    tcx.sess.emit_err(errors::ValueOfAssociatedStructAlreadySpecified {
                         span: binding.span,
                         prev_span: *prev_span,
                         item_name: binding.item_name,
@@ -488,6 +488,8 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             }
         }
 
+        let assoc_item_def_id = projection_ty.skip_binder().def_id;
+        let def_kind = tcx.def_kind(assoc_item_def_id);
         match binding.kind {
             ConvertedBindingKind::Equality(..) if return_type_notation => {
                 return Err(self.tcx().sess.emit_err(
@@ -499,11 +501,9 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                 // the "projection predicate" for:
                 //
                 // `<T as Iterator>::Item = u32`
-                let assoc_item_def_id = projection_ty.skip_binder().def_id;
-                let def_kind = tcx.def_kind(assoc_item_def_id);
                 match (def_kind, term.unpack()) {
-                    (hir::def::DefKind::AssocTy, ty::TermKind::Ty(_))
-                    | (hir::def::DefKind::AssocConst, ty::TermKind::Const(_)) => (),
+                    (DefKind::AssocTy, ty::TermKind::Ty(_))
+                    | (DefKind::AssocConst, ty::TermKind::Const(_)) => (),
                     (_, _) => {
                         let got = if let Some(_) = term.ty() { "type" } else { "constant" };
                         let expected = tcx.def_descr(assoc_item_def_id);
@@ -516,7 +516,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                             format!("{expected} defined here"),
                         );
 
-                        if let hir::def::DefKind::AssocConst = def_kind
+                        if let DefKind::AssocConst = def_kind
                           && let Some(t) = term.ty() && (t.is_enum() || t.references_error())
                           && tcx.features().associated_const_equality {
                             err.span_suggestion(
@@ -528,8 +528,8 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                         }
                         let reported = err.emit();
                         term = match def_kind {
-                            hir::def::DefKind::AssocTy => Ty::new_error(tcx, reported).into(),
-                            hir::def::DefKind::AssocConst => ty::Const::new_error(
+                            DefKind::AssocTy => Ty::new_error(tcx, reported).into(),
+                            DefKind::AssocConst => ty::Const::new_error(
                                 tcx,
                                 reported,
                                 tcx.type_of(assoc_item_def_id)
@@ -548,6 +548,15 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                 );
             }
             ConvertedBindingKind::Constraint(ast_bounds) => {
+                match def_kind {
+                    DefKind::AssocTy => {}
+                    _ => {
+                        return Err(tcx.sess.emit_err(errors::AssocBoundOnConst {
+                            span: assoc_ident.span,
+                            descr: tcx.def_descr(assoc_item_def_id),
+                        }));
+                    }
+                }
                 // "Desugar" a constraint like `T: Iterator<Item: Debug>` to
                 //
                 // `<T as Iterator>::Item: Debug`
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 8a5099804ed..46e8cf81bc1 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -8,7 +8,7 @@ use rustc_attr as attr;
 use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
-use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::{ItemKind, Node, PathSegment};
 use rustc_infer::infer::opaque_types::ConstrainOpaqueTypeRegionVisitor;
@@ -1443,12 +1443,12 @@ pub(super) fn check_type_params_are_used<'tcx>(
     }
 }
 
-pub(super) fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+pub(super) fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     let module = tcx.hir_module_items(module_def_id);
     for id in module.items() {
         check_item_type(tcx, id);
     }
-    if module_def_id == CRATE_DEF_ID {
+    if module_def_id == LocalModDefId::CRATE_DEF_ID {
         super::entry::check_for_entry_fn(tcx);
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 16d4d099c7e..f5beefc47f3 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -5,7 +5,7 @@ use rustc_ast as ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::ItemKind;
 use rustc_infer::infer::outlives::env::{OutlivesEnvironment, RegionBoundPairs};
@@ -1854,7 +1854,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
     }
 }
 
-fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalDefId) {
+fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalModDefId) {
     let items = tcx.hir_module_items(module);
     items.par_items(|item| tcx.ensure().check_well_formed(item.owner_id));
     items.par_impl_items(|item| tcx.ensure().check_well_formed(item.owner_id));
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 02a5d28b1e2..7b9f61d7ab2 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -22,7 +22,7 @@ use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{GenericParamKind, Node};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
@@ -48,7 +48,7 @@ mod type_of;
 ///////////////////////////////////////////////////////////////////////////
 // Main entry point
 
-fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn collect_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     tcx.hir().visit_item_likes_in_module(module_def_id, &mut CollectItemTypesVisitor { tcx });
 }
 
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 0babdf7e5b3..9471ad9ca90 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -918,3 +918,12 @@ pub struct UnusedAssociatedTypeBounds {
     #[suggestion(code = "")]
     pub span: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_analysis_assoc_bound_on_const)]
+#[note]
+pub struct AssocBoundOnConst {
+    #[primary_span]
+    pub span: Span,
+    pub descr: &'static str,
+}
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index 4f705eaf10a..788121f7a30 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -14,7 +14,7 @@ use min_specialization::check_min_specialization;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir::def::DefKind;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_span::{Span, Symbol};
@@ -51,7 +51,7 @@ mod min_specialization;
 /// impl<'a> Trait<Foo> for Bar { type X = &'a i32; }
 /// //   ^ 'a is unused and appears in assoc type, error
 /// ```
-fn check_mod_impl_wf(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_impl_wf(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     let min_specialization = tcx.features().min_specialization;
     let module = tcx.hir_module_items(module_def_id);
     for id in module.items() {
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index 6d926cd8aa1..7ad9f51ba70 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -107,7 +107,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let (span, code) = match prior_arm {
                 // The reason for the first arm to fail is not that the match arms diverge,
                 // but rather that there's a prior obligation that doesn't hold.
-                None => (arm_span, ObligationCauseCode::BlockTailExpression(arm.body.hir_id)),
+                None => {
+                    (arm_span, ObligationCauseCode::BlockTailExpression(arm.body.hir_id, match_src))
+                }
                 Some((prior_arm_block_id, prior_arm_ty, prior_arm_span)) => (
                     expr.span,
                     ObligationCauseCode::MatchExpressionArm(Box::new(MatchExpressionArmCause {
@@ -120,7 +122,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         scrut_span: scrut.span,
                         source: match_src,
                         prior_arms: other_arms.clone(),
-                        scrut_hir_id: scrut.hir_id,
                         opt_suggest_box_span,
                     })),
                 ),
@@ -145,7 +146,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 other_arms.remove(0);
             }
 
-            prior_arm = Some((arm_block_id, arm_ty, arm_span));
+            if !arm_ty.is_never() {
+                // When a match arm has type `!`, then it doesn't influence the expected type for
+                // the following arm. If all of the prior arms are `!`, then the influence comes
+                // from elsewhere and we shouldn't point to any previous arm.
+                prior_arm = Some((arm_block_id, arm_ty, arm_span));
+            }
         }
 
         // If all of the arms in the `match` diverge,
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index dd79d1afc62..02371f85ac3 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -599,6 +599,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 = self.typeck_results.borrow().qpath_res(qpath, callee_expr.hir_id)
             // Only suggest removing parens if there are no arguments
             && arg_exprs.is_empty()
+            && call_expr.span.contains(callee_expr.span)
         {
             let descr = match kind {
                 def::CtorOf::Struct => "struct",
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 1cfdc5b9e7f..726914a995b 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1603,7 +1603,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                         );
                         err.span_label(cause.span, "return type is not `()`");
                     }
-                    ObligationCauseCode::BlockTailExpression(blk_id) => {
+                    ObligationCauseCode::BlockTailExpression(blk_id, ..) => {
                         let parent_id = fcx.tcx.hir().parent_id(blk_id);
                         err = self.report_return_mismatched_types(
                             cause,
@@ -1650,10 +1650,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
 
                 augment_error(&mut err);
 
-                let is_insufficiently_polymorphic =
-                    matches!(coercion_error, TypeError::RegionsInsufficientlyPolymorphic(..));
-
-                if !is_insufficiently_polymorphic && let Some(expr) = expression {
+                if let Some(expr) = expression {
                     fcx.emit_coerce_suggestions(
                         &mut err,
                         expr,
@@ -1751,7 +1748,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 ) && !in_external_macro(fcx.tcx.sess, cond_expr.span)
                     && !matches!(
                         cond_expr.kind,
-                        hir::ExprKind::Match(.., hir::MatchSource::TryDesugar)
+                        hir::ExprKind::Match(.., hir::MatchSource::TryDesugar(_))
                     )
             {
                 err.span_label(cond_expr.span, "expected this to be `()`");
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index b05cef56ad2..5b06088c348 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -84,6 +84,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         self.annotate_expected_due_to_let_ty(err, expr, error);
 
+        // FIXME(#73154): For now, we do leak check when coercing function
+        // pointers in typeck, instead of only during borrowck. This can lead
+        // to these `RegionsInsufficientlyPolymorphic` errors that aren't helpful.
+        if matches!(error, Some(TypeError::RegionsInsufficientlyPolymorphic(..))) {
+            return;
+        }
+
         if self.is_destruct_assignment_desugaring(expr) {
             return;
         }
@@ -263,22 +270,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let expr_ty = self.resolve_vars_if_possible(checked_ty);
         let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e);
 
-        let is_insufficiently_polymorphic =
-            matches!(e, TypeError::RegionsInsufficientlyPolymorphic(..));
-
-        // FIXME(#73154): For now, we do leak check when coercing function
-        // pointers in typeck, instead of only during borrowck. This can lead
-        // to these `RegionsInsufficientlyPolymorphic` errors that aren't helpful.
-        if !is_insufficiently_polymorphic {
-            self.emit_coerce_suggestions(
-                &mut err,
-                expr,
-                expr_ty,
-                expected,
-                expected_ty_expr,
-                Some(e),
-            );
-        }
+        self.emit_coerce_suggestions(&mut err, expr, expr_ty, expected, expected_ty_expr, Some(e));
 
         (expected, Some(err))
     }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 40f9a954034..817115012a4 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -1580,7 +1580,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let coerce = ctxt.coerce.as_mut().unwrap();
             if let Some((tail_expr, tail_expr_ty)) = tail_expr_ty {
                 let span = self.get_expr_coercion_span(tail_expr);
-                let cause = self.cause(span, ObligationCauseCode::BlockTailExpression(blk.hir_id));
+                let cause = self.cause(
+                    span,
+                    ObligationCauseCode::BlockTailExpression(blk.hir_id, hir::MatchSource::Normal),
+                );
                 let ty_for_diagnostic = coerce.merged_ty();
                 // We use coerce_inner here because we want to augment the error
                 // suggesting to wrap the block in square brackets if it might've
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 75cca973306..ac5468f3dfd 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -743,6 +743,35 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             ObligationCauseCode::Pattern { origin_expr: false, span: Some(span), .. } => {
                 err.span_label(span, "expected due to this");
             }
+            ObligationCauseCode::BlockTailExpression(
+                _,
+                hir::MatchSource::TryDesugar(scrut_hir_id),
+            ) => {
+                if let Some(ty::error::ExpectedFound { expected, .. }) = exp_found {
+                    let scrut_expr = self.tcx.hir().expect_expr(scrut_hir_id);
+                    let scrut_ty = if let hir::ExprKind::Call(_, args) = &scrut_expr.kind {
+                        let arg_expr = args.first().expect("try desugaring call w/out arg");
+                        self.typeck_results.as_ref().and_then(|typeck_results| {
+                            typeck_results.expr_ty_opt(arg_expr)
+                        })
+                    } else {
+                        bug!("try desugaring w/out call expr as scrutinee");
+                    };
+
+                    match scrut_ty {
+                        Some(ty) if expected == ty => {
+                            let source_map = self.tcx.sess.source_map();
+                            err.span_suggestion(
+                                source_map.end_point(cause.span()),
+                                "try removing this `?`",
+                                "",
+                                Applicability::MachineApplicable,
+                            );
+                        }
+                        _ => {}
+                    }
+                }
+            },
             ObligationCauseCode::MatchExpressionArm(box MatchExpressionArmCause {
                 arm_block_id,
                 arm_span,
@@ -752,12 +781,11 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 prior_arm_ty,
                 source,
                 ref prior_arms,
-                scrut_hir_id,
                 opt_suggest_box_span,
                 scrut_span,
                 ..
             }) => match source {
-                hir::MatchSource::TryDesugar => {
+                hir::MatchSource::TryDesugar(scrut_hir_id) => {
                     if let Some(ty::error::ExpectedFound { expected, .. }) = exp_found {
                         let scrut_expr = self.tcx.hir().expect_expr(scrut_hir_id);
                         let scrut_ty = if let hir::ExprKind::Call(_, args) = &scrut_expr.kind {
@@ -1927,7 +1955,12 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     true
                 };
 
-            if should_suggest_fixes {
+            // FIXME(#73154): For now, we do leak check when coercing function
+            // pointers in typeck, instead of only during borrowck. This can lead
+            // to these `RegionsInsufficientlyPolymorphic` errors that aren't helpful.
+            if should_suggest_fixes
+                && !matches!(terr, TypeError::RegionsInsufficientlyPolymorphic(..))
+            {
                 self.suggest_tuple_pattern(cause, &exp_found, diag);
                 self.suggest_accessing_field_where_appropriate(cause, &exp_found, diag);
                 self.suggest_await_on_expect_found(cause, span, &exp_found, diag);
@@ -1973,7 +2006,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         trace: &TypeTrace<'tcx>,
         terr: TypeError<'tcx>,
     ) -> Vec<TypeErrorAdditionalDiags> {
-        use crate::traits::ObligationCauseCode::MatchExpressionArm;
+        use crate::traits::ObligationCauseCode::{BlockTailExpression, MatchExpressionArm};
         let mut suggestions = Vec::new();
         let span = trace.cause.span();
         let values = self.resolve_vars_if_possible(trace.values);
@@ -1991,11 +2024,17 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 // specify a byte literal
                 (ty::Uint(ty::UintTy::U8), ty::Char) => {
                     if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span)
-                        && let Some(code) = code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
-                        && !code.starts_with("\\u") // forbid all Unicode escapes
-                        && code.chars().next().is_some_and(|c| c.is_ascii()) // forbids literal Unicode characters beyond ASCII
+                        && let Some(code) =
+                            code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
+                        // forbid all Unicode escapes
+                        && !code.starts_with("\\u")
+                        // forbids literal Unicode characters beyond ASCII
+                        && code.chars().next().is_some_and(|c| c.is_ascii())
                     {
-                        suggestions.push(TypeErrorAdditionalDiags::MeantByteLiteral { span, code: escape_literal(code) })
+                        suggestions.push(TypeErrorAdditionalDiags::MeantByteLiteral {
+                            span,
+                            code: escape_literal(code),
+                        })
                     }
                 }
                 // If a character was expected and the found expression is a string literal
@@ -2006,7 +2045,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                         && let Some(code) = code.strip_prefix('"').and_then(|s| s.strip_suffix('"'))
                         && code.chars().count() == 1
                     {
-                        suggestions.push(TypeErrorAdditionalDiags::MeantCharLiteral { span, code: escape_literal(code) })
+                        suggestions.push(TypeErrorAdditionalDiags::MeantCharLiteral {
+                            span,
+                            code: escape_literal(code),
+                        })
                     }
                 }
                 // If a string was expected and the found expression is a character literal,
@@ -2016,7 +2058,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                         if let Some(code) =
                             code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
                         {
-                            suggestions.push(TypeErrorAdditionalDiags::MeantStrLiteral { span, code: escape_literal(code) })
+                            suggestions.push(TypeErrorAdditionalDiags::MeantStrLiteral {
+                                span,
+                                code: escape_literal(code),
+                            })
                         }
                     }
                 }
@@ -2025,17 +2070,24 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 (ty::Bool, ty::Tuple(list)) => if list.len() == 0 {
                     suggestions.extend(self.suggest_let_for_letchains(&trace.cause, span));
                 }
-                (ty::Array(_, _), ty::Array(_, _)) => suggestions.extend(self.suggest_specify_actual_length(terr, trace, span)),
+                (ty::Array(_, _), ty::Array(_, _)) => {
+                    suggestions.extend(self.suggest_specify_actual_length(terr, trace, span))
+                }
                 _ => {}
             }
         }
         let code = trace.cause.code();
-        if let &MatchExpressionArm(box MatchExpressionArmCause { source, .. }) = code
-                    && let hir::MatchSource::TryDesugar = source
-                    && let Some((expected_ty, found_ty, _, _)) = self.values_str(trace.values)
-                {
-                    suggestions.push(TypeErrorAdditionalDiags::TryCannotConvert { found: found_ty.content(), expected: expected_ty.content() });
-                }
+        if let &(MatchExpressionArm(box MatchExpressionArmCause { source, .. })
+            | BlockTailExpression(.., source)
+        ) = code
+            && let hir::MatchSource::TryDesugar(_) = source
+            && let Some((expected_ty, found_ty, _, _)) = self.values_str(trace.values)
+        {
+            suggestions.push(TypeErrorAdditionalDiags::TryCannotConvert {
+                found: found_ty.content(),
+                expected: expected_ty.content(),
+            });
+        }
         suggestions
     }
 
@@ -2905,8 +2957,11 @@ impl<'tcx> ObligationCauseExt<'tcx> for ObligationCause<'tcx> {
             CompareImplItemObligation { kind: ty::AssocKind::Const, .. } => {
                 ObligationCauseFailureCode::ConstCompat { span, subdiags }
             }
+            BlockTailExpression(.., hir::MatchSource::TryDesugar(_)) => {
+                ObligationCauseFailureCode::TryCompat { span, subdiags }
+            }
             MatchExpressionArm(box MatchExpressionArmCause { source, .. }) => match source {
-                hir::MatchSource::TryDesugar => {
+                hir::MatchSource::TryDesugar(_) => {
                     ObligationCauseFailureCode::TryCompat { span, subdiags }
                 }
                 _ => ObligationCauseFailureCode::MatchCompat { span, subdiags },
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
index d08b6ba5e47..3cfda0cc5c0 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -146,7 +146,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
         if let SubregionOrigin::Subtype(box TypeTrace { cause, .. }) = sub_origin {
             if let ObligationCauseCode::ReturnValue(hir_id)
-            | ObligationCauseCode::BlockTailExpression(hir_id) = cause.code()
+            | ObligationCauseCode::BlockTailExpression(hir_id, ..) = cause.code()
             {
                 let parent_id = tcx.hir().get_parent_item(*hir_id);
                 if let Some(fn_decl) = tcx.hir().fn_decl_by_hir_id(parent_id.into()) {
diff --git a/compiler/rustc_lint/src/late.rs b/compiler/rustc_lint/src/late.rs
index 3331dbad4a9..73af51d9e90 100644
--- a/compiler/rustc_lint/src/late.rs
+++ b/compiler/rustc_lint/src/late.rs
@@ -19,7 +19,7 @@ use rustc_ast as ast;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::sync::join;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_hir::intravisit as hir_visit;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
@@ -338,7 +338,7 @@ crate::late_lint_methods!(impl_late_lint_pass, []);
 
 pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
     tcx: TyCtxt<'tcx>,
-    module_def_id: LocalDefId,
+    module_def_id: LocalModDefId,
     builtin_lints: T,
 ) {
     let context = LateContext {
@@ -369,7 +369,7 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
 
 fn late_lint_mod_inner<'tcx, T: LateLintPass<'tcx>>(
     tcx: TyCtxt<'tcx>,
-    module_def_id: LocalDefId,
+    module_def_id: LocalModDefId,
     context: LateContext<'tcx>,
     pass: T,
 ) {
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 42378951af3..585b10e79e4 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -90,7 +90,7 @@ use rustc_ast as ast;
 use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::{
@@ -145,7 +145,7 @@ pub fn provide(providers: &mut Providers) {
     *providers = Providers { lint_mod, ..*providers };
 }
 
-fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     late_lint_mod(tcx, module_def_id, BuiltinCombinedModuleLateLintPass::new());
 }
 
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 3747e562cec..96c31a90da8 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -3366,6 +3366,7 @@ declare_lint_pass! {
         BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
         CENUM_IMPL_DROP_CAST,
         COHERENCE_LEAK_CHECK,
+        COINDUCTIVE_OVERLAP_IN_COHERENCE,
         CONFLICTING_REPR_HINTS,
         CONST_EVALUATABLE_UNCHECKED,
         CONST_ITEM_MUTATION,
@@ -4423,6 +4424,44 @@ declare_lint! {
 }
 
 declare_lint! {
+    /// The `coinductive_overlap_in_coherence` lint detects impls which are currently
+    /// considered not overlapping, but may be considered to overlap if support for
+    /// coinduction is added to the trait solver.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// #![deny(coinductive_overlap_in_coherence)]
+    ///
+    /// trait CyclicTrait {}
+    /// impl<T: CyclicTrait> CyclicTrait for T {}
+    ///
+    /// trait Trait {}
+    /// impl<T: CyclicTrait> Trait for T {}
+    /// // conflicting impl with the above
+    /// impl Trait for u8 {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// We have two choices for impl which satisfy `u8: Trait`: the blanket impl
+    /// for generic `T`, and the direct impl for `u8`. These two impls nominally
+    /// overlap, since we can infer `T = u8` in the former impl, but since the where
+    /// clause `u8: CyclicTrait` would end up resulting in a cycle (since it depends
+    /// on itself), the blanket impl is not considered to hold for `u8`. This will
+    /// change in a future release.
+    pub COINDUCTIVE_OVERLAP_IN_COHERENCE,
+    Warn,
+    "impls that are not considered to overlap may be considered to \
+    overlap in the future",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #114040 <https://github.com/rust-lang/rust/issues/114040>",
+    };
+}
+
+declare_lint! {
     /// The `unknown_diagnostic_attributes` lint detects unrecognized diagnostic attributes.
     ///
     /// ### Example
diff --git a/compiler/rustc_middle/src/dep_graph/dep_node.rs b/compiler/rustc_middle/src/dep_graph/dep_node.rs
index 06251bccc98..04c09d33400 100644
--- a/compiler/rustc_middle/src/dep_graph/dep_node.rs
+++ b/compiler/rustc_middle/src/dep_graph/dep_node.rs
@@ -60,7 +60,7 @@ use crate::mir::mono::MonoItem;
 use crate::ty::TyCtxt;
 
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
+use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalModDefId, ModDefId, LOCAL_CRATE};
 use rustc_hir::definitions::DefPathHash;
 use rustc_hir::{HirId, ItemLocalId, OwnerId};
 use rustc_query_system::dep_graph::FingerprintStyle;
@@ -387,3 +387,53 @@ impl<'tcx> DepNodeParams<TyCtxt<'tcx>> for HirId {
         }
     }
 }
+
+macro_rules! impl_for_typed_def_id {
+    ($Name:ident, $LocalName:ident) => {
+        impl<'tcx> DepNodeParams<TyCtxt<'tcx>> for $Name {
+            #[inline(always)]
+            fn fingerprint_style() -> FingerprintStyle {
+                FingerprintStyle::DefPathHash
+            }
+
+            #[inline(always)]
+            fn to_fingerprint(&self, tcx: TyCtxt<'tcx>) -> Fingerprint {
+                self.to_def_id().to_fingerprint(tcx)
+            }
+
+            #[inline(always)]
+            fn to_debug_str(&self, tcx: TyCtxt<'tcx>) -> String {
+                self.to_def_id().to_debug_str(tcx)
+            }
+
+            #[inline(always)]
+            fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+                DefId::recover(tcx, dep_node).map($Name::new_unchecked)
+            }
+        }
+
+        impl<'tcx> DepNodeParams<TyCtxt<'tcx>> for $LocalName {
+            #[inline(always)]
+            fn fingerprint_style() -> FingerprintStyle {
+                FingerprintStyle::DefPathHash
+            }
+
+            #[inline(always)]
+            fn to_fingerprint(&self, tcx: TyCtxt<'tcx>) -> Fingerprint {
+                self.to_def_id().to_fingerprint(tcx)
+            }
+
+            #[inline(always)]
+            fn to_debug_str(&self, tcx: TyCtxt<'tcx>) -> String {
+                self.to_def_id().to_debug_str(tcx)
+            }
+
+            #[inline(always)]
+            fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+                LocalDefId::recover(tcx, dep_node).map($LocalName::new_unchecked)
+            }
+        }
+    };
+}
+
+impl_for_typed_def_id! { ModDefId, LocalModDefId }
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 224f897492b..467962b39bb 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -8,7 +8,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::{par_for_each_in, DynSend, DynSync};
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::*;
@@ -148,7 +148,7 @@ impl<'hir> Map<'hir> {
     }
 
     #[inline]
-    pub fn module_items(self, module: LocalDefId) -> impl Iterator<Item = ItemId> + 'hir {
+    pub fn module_items(self, module: LocalModDefId) -> impl Iterator<Item = ItemId> + 'hir {
         self.tcx.hir_module_items(module).items()
     }
 
@@ -169,8 +169,8 @@ impl<'hir> Map<'hir> {
     }
 
     #[inline]
-    pub fn local_def_id_to_hir_id(self, def_id: LocalDefId) -> HirId {
-        self.tcx.local_def_id_to_hir_id(def_id)
+    pub fn local_def_id_to_hir_id(self, def_id: impl Into<LocalDefId>) -> HirId {
+        self.tcx.local_def_id_to_hir_id(def_id.into())
     }
 
     /// Do not call this function directly. The query should be called.
@@ -529,8 +529,8 @@ impl<'hir> Map<'hir> {
         self.krate_attrs().iter().any(|attr| attr.has_name(sym::rustc_coherence_is_core))
     }
 
-    pub fn get_module(self, module: LocalDefId) -> (&'hir Mod<'hir>, Span, HirId) {
-        let hir_id = HirId::make_owner(module);
+    pub fn get_module(self, module: LocalModDefId) -> (&'hir Mod<'hir>, Span, HirId) {
+        let hir_id = HirId::make_owner(module.to_local_def_id());
         match self.tcx.hir_owner(hir_id.owner).map(|o| o.node) {
             Some(OwnerNode::Item(&Item { span, kind: ItemKind::Mod(ref m), .. })) => {
                 (m, span, hir_id)
@@ -542,7 +542,7 @@ impl<'hir> Map<'hir> {
 
     /// Walks the contents of the local crate. See also `visit_all_item_likes_in_crate`.
     pub fn walk_toplevel_module(self, visitor: &mut impl Visitor<'hir>) {
-        let (top_mod, span, hir_id) = self.get_module(CRATE_DEF_ID);
+        let (top_mod, span, hir_id) = self.get_module(LocalModDefId::CRATE_DEF_ID);
         visitor.visit_mod(top_mod, span, hir_id);
     }
 
@@ -595,7 +595,7 @@ impl<'hir> Map<'hir> {
 
     /// This method is the equivalent of `visit_all_item_likes_in_crate` but restricted to
     /// item-likes in a single module.
-    pub fn visit_item_likes_in_module<V>(self, module: LocalDefId, visitor: &mut V)
+    pub fn visit_item_likes_in_module<V>(self, module: LocalModDefId, visitor: &mut V)
     where
         V: Visitor<'hir>,
     {
@@ -618,17 +618,19 @@ impl<'hir> Map<'hir> {
         }
     }
 
-    pub fn for_each_module(self, mut f: impl FnMut(LocalDefId)) {
+    pub fn for_each_module(self, mut f: impl FnMut(LocalModDefId)) {
         let crate_items = self.tcx.hir_crate_items(());
         for module in crate_items.submodules.iter() {
-            f(module.def_id)
+            f(LocalModDefId::new_unchecked(module.def_id))
         }
     }
 
     #[inline]
-    pub fn par_for_each_module(self, f: impl Fn(LocalDefId) + DynSend + DynSync) {
+    pub fn par_for_each_module(self, f: impl Fn(LocalModDefId) + DynSend + DynSync) {
         let crate_items = self.tcx.hir_crate_items(());
-        par_for_each_in(&crate_items.submodules[..], |module| f(module.def_id))
+        par_for_each_in(&crate_items.submodules[..], |module| {
+            f(LocalModDefId::new_unchecked(module.def_id))
+        })
     }
 
     /// Returns an iterator for the nodes in the ancestor tree of the `current_id`
@@ -1324,7 +1326,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
     }
 }
 
-pub(super) fn hir_module_items(tcx: TyCtxt<'_>, module_id: LocalDefId) -> ModuleItems {
+pub(super) fn hir_module_items(tcx: TyCtxt<'_>, module_id: LocalModDefId) -> ModuleItems {
     let mut collector = ItemCollector::new(tcx, false);
 
     let (hir_mod, span, hir_id) = tcx.hir().get_module(module_id);
diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index 06b25556c82..e8fd469e1fb 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -11,7 +11,7 @@ use crate::ty::{EarlyBinder, ImplSubject, TyCtxt};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{par_for_each_in, DynSend, DynSync};
 use rustc_hir::def::DefKind;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::*;
 use rustc_query_system::ich::StableHashingContext;
 use rustc_span::{ExpnId, DUMMY_SP};
@@ -101,22 +101,22 @@ impl<'tcx> TyCtxt<'tcx> {
         map::Map { tcx: self }
     }
 
-    pub fn parent_module(self, id: HirId) -> LocalDefId {
+    pub fn parent_module(self, id: HirId) -> LocalModDefId {
         if !id.is_owner() && self.def_kind(id.owner) == DefKind::Mod {
-            id.owner.def_id
+            LocalModDefId::new_unchecked(id.owner.def_id)
         } else {
             self.parent_module_from_def_id(id.owner.def_id)
         }
     }
 
-    pub fn parent_module_from_def_id(self, mut id: LocalDefId) -> LocalDefId {
+    pub fn parent_module_from_def_id(self, mut id: LocalDefId) -> LocalModDefId {
         while let Some(parent) = self.opt_local_parent(id) {
             id = parent;
             if self.def_kind(id) == DefKind::Mod {
                 break;
             }
         }
-        id
+        LocalModDefId::new_unchecked(id)
     }
 
     pub fn impl_subject(self, def_id: DefId) -> EarlyBinder<ImplSubject<'tcx>> {
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index f5576b59571..d3fc1b2850e 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -35,7 +35,6 @@
 #![feature(if_let_guard)]
 #![feature(inline_const)]
 #![feature(iter_from_generator)]
-#![feature(local_key_cell_methods)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(extern_types)]
diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs
index 2c481745d98..348f79ed6a8 100644
--- a/compiler/rustc_middle/src/query/erase.rs
+++ b/compiler/rustc_middle/src/query/erase.rs
@@ -235,6 +235,7 @@ trivial! {
     rustc_hir::def_id::DefId,
     rustc_hir::def_id::DefIndex,
     rustc_hir::def_id::LocalDefId,
+    rustc_hir::def_id::LocalModDefId,
     rustc_hir::def::DefKind,
     rustc_hir::Defaultness,
     rustc_hir::definitions::DefKey,
diff --git a/compiler/rustc_middle/src/query/keys.rs b/compiler/rustc_middle/src/query/keys.rs
index a8aec3096d5..01bdc4c9904 100644
--- a/compiler/rustc_middle/src/query/keys.rs
+++ b/compiler/rustc_middle/src/query/keys.rs
@@ -8,7 +8,7 @@ use crate::ty::fast_reject::SimplifiedType;
 use crate::ty::layout::{TyAndLayout, ValidityRequirement};
 use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::{GenericArg, GenericArgsRef};
-use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
+use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalModDefId, ModDefId, LOCAL_CRATE};
 use rustc_hir::hir_id::{HirId, OwnerId};
 use rustc_query_system::query::{DefaultCacheSelector, SingleCacheSelector, VecCacheSelector};
 use rustc_span::symbol::{Ident, Symbol};
@@ -175,6 +175,41 @@ impl AsLocalKey for DefId {
     }
 }
 
+impl Key for LocalModDefId {
+    type CacheSelector = DefaultCacheSelector<Self>;
+
+    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
+        tcx.def_span(*self)
+    }
+
+    #[inline(always)]
+    fn key_as_def_id(&self) -> Option<DefId> {
+        Some(self.to_def_id())
+    }
+}
+
+impl Key for ModDefId {
+    type CacheSelector = DefaultCacheSelector<Self>;
+
+    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
+        tcx.def_span(*self)
+    }
+
+    #[inline(always)]
+    fn key_as_def_id(&self) -> Option<DefId> {
+        Some(self.to_def_id())
+    }
+}
+
+impl AsLocalKey for ModDefId {
+    type LocalKey = LocalModDefId;
+
+    #[inline(always)]
+    fn as_local_key(&self) -> Option<Self::LocalKey> {
+        self.as_local()
+    }
+}
+
 impl Key for SimplifiedType {
     type CacheSelector = DefaultCacheSelector<Self>;
 
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 5af77c6c4cb..94ae0dcb517 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -67,7 +67,7 @@ use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, DocLinkResMap};
 use rustc_hir::def_id::{
-    CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LocalDefIdMap, LocalDefIdSet,
+    CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LocalDefIdMap, LocalDefIdSet, LocalModDefId,
 };
 use rustc_hir::lang_items::{LangItem, LanguageItems};
 use rustc_hir::{Crate, ItemLocalId, TraitCandidate};
@@ -167,7 +167,7 @@ rustc_queries! {
     ///
     /// This can be conveniently accessed by `tcx.hir().visit_item_likes_in_module`.
     /// Avoid calling this query directly.
-    query hir_module_items(key: LocalDefId) -> &'tcx rustc_middle::hir::ModuleItems {
+    query hir_module_items(key: LocalModDefId) -> &'tcx rustc_middle::hir::ModuleItems {
         arena_cache
         desc { |tcx| "getting HIR module items in `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { true }
@@ -388,7 +388,6 @@ rustc_queries! {
     }
 
     query shallow_lint_levels_on(key: hir::OwnerId) -> &'tcx rustc_middle::lint::ShallowLintLevelMap {
-        eval_always // fetches `resolutions`
         arena_cache
         desc { |tcx| "looking up lint levels for `{}`", tcx.def_path_str(key) }
     }
@@ -896,7 +895,7 @@ rustc_queries! {
     }
 
     /// Performs lint checking for the module.
-    query lint_mod(key: LocalDefId) -> () {
+    query lint_mod(key: LocalModDefId) -> () {
         desc { |tcx| "linting {}", describe_as_module(key, tcx) }
     }
 
@@ -905,35 +904,35 @@ rustc_queries! {
     }
 
     /// Checks the attributes in the module.
-    query check_mod_attrs(key: LocalDefId) -> () {
+    query check_mod_attrs(key: LocalModDefId) -> () {
         desc { |tcx| "checking attributes in {}", describe_as_module(key, tcx) }
     }
 
     /// Checks for uses of unstable APIs in the module.
-    query check_mod_unstable_api_usage(key: LocalDefId) -> () {
+    query check_mod_unstable_api_usage(key: LocalModDefId) -> () {
         desc { |tcx| "checking for unstable API usage in {}", describe_as_module(key, tcx) }
     }
 
     /// Checks the const bodies in the module for illegal operations (e.g. `if` or `loop`).
-    query check_mod_const_bodies(key: LocalDefId) -> () {
+    query check_mod_const_bodies(key: LocalModDefId) -> () {
         desc { |tcx| "checking consts in {}", describe_as_module(key, tcx) }
     }
 
     /// Checks the loops in the module.
-    query check_mod_loops(key: LocalDefId) -> () {
+    query check_mod_loops(key: LocalModDefId) -> () {
         desc { |tcx| "checking loops in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_naked_functions(key: LocalDefId) -> () {
+    query check_mod_naked_functions(key: LocalModDefId) -> () {
         desc { |tcx| "checking naked functions in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_item_types(key: LocalDefId) -> () {
+    query check_mod_item_types(key: LocalModDefId) -> () {
         desc { |tcx| "checking item types in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_privacy(key: LocalDefId) -> () {
-        desc { |tcx| "checking privacy in {}", describe_as_module(key, tcx) }
+    query check_mod_privacy(key: LocalModDefId) -> () {
+        desc { |tcx| "checking privacy in {}", describe_as_module(key.to_local_def_id(), tcx) }
     }
 
     query check_liveness(key: LocalDefId) {
@@ -952,19 +951,19 @@ rustc_queries! {
         desc { "finding live symbols in crate" }
     }
 
-    query check_mod_deathness(key: LocalDefId) -> () {
+    query check_mod_deathness(key: LocalModDefId) -> () {
         desc { |tcx| "checking deathness of variables in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_impl_wf(key: LocalDefId) -> () {
+    query check_mod_impl_wf(key: LocalModDefId) -> () {
         desc { |tcx| "checking that impls are well-formed in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_type_wf(key: LocalDefId) -> () {
+    query check_mod_type_wf(key: LocalModDefId) -> () {
         desc { |tcx| "checking that types are well-formed in {}", describe_as_module(key, tcx) }
     }
 
-    query collect_mod_item_types(key: LocalDefId) -> () {
+    query collect_mod_item_types(key: LocalModDefId) -> () {
         desc { |tcx| "collecting item types in {}", describe_as_module(key, tcx) }
     }
 
diff --git a/compiler/rustc_middle/src/query/plumbing.rs b/compiler/rustc_middle/src/query/plumbing.rs
index 97edfc2fca2..a1aac284621 100644
--- a/compiler/rustc_middle/src/query/plumbing.rs
+++ b/compiler/rustc_middle/src/query/plumbing.rs
@@ -545,6 +545,7 @@ macro_rules! define_feedable {
 
 mod sealed {
     use super::{DefId, LocalDefId, OwnerId};
+    use rustc_hir::def_id::{LocalModDefId, ModDefId};
 
     /// An analogue of the `Into` trait that's intended only for query parameters.
     ///
@@ -588,6 +589,27 @@ mod sealed {
             self.to_def_id()
         }
     }
+
+    impl IntoQueryParam<DefId> for ModDefId {
+        #[inline(always)]
+        fn into_query_param(self) -> DefId {
+            self.to_def_id()
+        }
+    }
+
+    impl IntoQueryParam<DefId> for LocalModDefId {
+        #[inline(always)]
+        fn into_query_param(self) -> DefId {
+            self.to_def_id()
+        }
+    }
+
+    impl IntoQueryParam<LocalDefId> for LocalModDefId {
+        #[inline(always)]
+        fn into_query_param(self) -> LocalDefId {
+            self.into()
+        }
+    }
 }
 
 pub use sealed::IntoQueryParam;
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index 8e2e71fd879..ebc1c11902b 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -346,6 +346,7 @@ pub enum ExprKind<'tcx> {
     /// A `match` expression.
     Match {
         scrutinee: ExprId,
+        scrutinee_hir_id: hir::HirId,
         arms: Box<[ArmId]>,
     },
     /// A block.
diff --git a/compiler/rustc_middle/src/thir/visit.rs b/compiler/rustc_middle/src/thir/visit.rs
index 55ec17423ec..681400dbb94 100644
--- a/compiler/rustc_middle/src/thir/visit.rs
+++ b/compiler/rustc_middle/src/thir/visit.rs
@@ -70,7 +70,7 @@ pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Exp
             visitor.visit_expr(&visitor.thir()[expr]);
         }
         Loop { body } => visitor.visit_expr(&visitor.thir()[body]),
-        Match { scrutinee, ref arms } => {
+        Match { scrutinee, ref arms, .. } => {
             visitor.visit_expr(&visitor.thir()[scrutinee]);
             for &arm in &**arms {
                 visitor.visit_arm(&visitor.thir()[arm]);
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 2d655041c32..3465759b913 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -402,7 +402,7 @@ pub enum ObligationCauseCode<'tcx> {
     OpaqueReturnType(Option<(Ty<'tcx>, Span)>),
 
     /// Block implicit return
-    BlockTailExpression(hir::HirId),
+    BlockTailExpression(hir::HirId, hir::MatchSource),
 
     /// #[feature(trivial_bounds)] is not enabled
     TrivialBound,
@@ -543,7 +543,6 @@ pub struct MatchExpressionArmCause<'tcx> {
     pub scrut_span: Span,
     pub source: hir::MatchSource,
     pub prior_arms: Vec<Span>,
-    pub scrut_hir_id: hir::HirId,
     pub opt_suggest_box_span: Option<Span>,
 }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 48aa25dba6d..1274f427e4f 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -238,7 +238,7 @@ pub struct ImplHeader<'tcx> {
     pub impl_def_id: DefId,
     pub self_ty: Ty<'tcx>,
     pub trait_ref: Option<TraitRef<'tcx>>,
-    pub predicates: Vec<Predicate<'tcx>>,
+    pub predicates: Vec<(Predicate<'tcx>, Span)>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug, TypeFoldable, TypeVisitable)]
@@ -355,8 +355,8 @@ impl TyCtxt<'_> {
 
     #[inline]
     #[track_caller]
-    pub fn local_parent(self, id: LocalDefId) -> LocalDefId {
-        self.parent(id.to_def_id()).expect_local()
+    pub fn local_parent(self, id: impl Into<LocalDefId>) -> LocalDefId {
+        self.parent(id.into().to_def_id()).expect_local()
     }
 
     pub fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool {
diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
index 83a75d0c6b9..05871d0bc39 100644
--- a/compiler/rustc_middle/src/ty/print/mod.rs
+++ b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -329,7 +329,8 @@ impl<'tcx, P: Printer<'tcx>> Print<'tcx, P> for ty::Const<'tcx> {
 }
 
 // This is only used by query descriptions
-pub fn describe_as_module(def_id: LocalDefId, tcx: TyCtxt<'_>) -> String {
+pub fn describe_as_module(def_id: impl Into<LocalDefId>, tcx: TyCtxt<'_>) -> String {
+    let def_id = def_id.into();
     if def_id.is_top_level_module() {
         "top-level module".to_string()
     } else {
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index bb6513363c9..ac0c88468fa 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -11,7 +11,7 @@ use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_data_structures::sso::SsoHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
-use rustc_hir::def_id::{DefId, DefIdSet, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, DefIdSet, ModDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPathData, DefPathDataName, DisambiguatedDefPathData};
 use rustc_hir::LangItem;
 use rustc_session::config::TrimmedDefPaths;
@@ -326,7 +326,8 @@ pub trait PrettyPrinter<'tcx>:
             {
                 this
                     .tcx()
-                    .module_children(visible_parent)
+                    // FIXME(typed_def_id): Further propagate ModDefId
+                    .module_children(ModDefId::new_unchecked(*visible_parent))
                     .iter()
                     .filter(|child| child.res.opt_def_id() == Some(def_id))
                     .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
@@ -551,7 +552,8 @@ pub trait PrettyPrinter<'tcx>:
                 // that's public and whose identifier isn't `_`.
                 let reexport = self
                     .tcx()
-                    .module_children(visible_parent)
+                    // FIXME(typed_def_id): Further propagate ModDefId
+                    .module_children(ModDefId::new_unchecked(visible_parent))
                     .iter()
                     .filter(|child| child.res.opt_def_id() == Some(def_id))
                     .find(|child| child.vis.is_public() && child.ident.name != kw::Underscore)
diff --git a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
index 295cddb1e15..fe5190900e9 100644
--- a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
+++ b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
@@ -65,7 +65,7 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> {
                 let target = self.parse_block(args[1])?;
                 self.parse_call(args[2], destination, target)
             },
-            ExprKind::Match { scrutinee, arms } => {
+            ExprKind::Match { scrutinee, arms, .. } => {
                 let discr = self.parse_operand(*scrutinee)?;
                 self.parse_match(arms, expr.span).map(|t| TerminatorKind::SwitchInt { discr, targets: t })
             },
diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs
index c750727903f..a5c86e31a29 100644
--- a/compiler/rustc_mir_build/src/build/expr/into.rs
+++ b/compiler/rustc_mir_build/src/build/expr/into.rs
@@ -47,7 +47,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             ExprKind::Block { block: ast_block } => {
                 this.ast_block(destination, block, ast_block, source_info)
             }
-            ExprKind::Match { scrutinee, ref arms } => {
+            ExprKind::Match { scrutinee, ref arms, .. } => {
                 this.match_expr(destination, expr_span, block, &this.thir[scrutinee], arms)
             }
             ExprKind::If { cond, then, else_opt, if_then_scope } => {
diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index a96d837b3ad..6c1f7d7a606 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -732,6 +732,7 @@ impl<'tcx> Cx<'tcx> {
             },
             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
                 scrutinee: self.mirror_expr(discr),
+                scrutinee_hir_id: discr.hir_id,
                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
             },
             hir::ExprKind::Loop(ref body, ..) => {
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index a786e659664..383e80851f0 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -135,10 +135,12 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for MatchVisitor<'a, '_, 'tcx> {
                 });
                 return;
             }
-            ExprKind::Match { scrutinee, box ref arms } => {
+            ExprKind::Match { scrutinee, scrutinee_hir_id, box ref arms } => {
                 let source = match ex.span.desugaring_kind() {
                     Some(DesugaringKind::ForLoop) => hir::MatchSource::ForLoopDesugar,
-                    Some(DesugaringKind::QuestionMark) => hir::MatchSource::TryDesugar,
+                    Some(DesugaringKind::QuestionMark) => {
+                        hir::MatchSource::TryDesugar(scrutinee_hir_id)
+                    }
                     Some(DesugaringKind::Await) => hir::MatchSource::AwaitDesugar,
                     _ => hir::MatchSource::Normal,
                 };
@@ -277,7 +279,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
             | hir::MatchSource::FormatArgs => report_arm_reachability(&cx, &report),
             // Unreachable patterns in try and await expressions occur when one of
             // the arms are an uninhabited type. Which is OK.
-            hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar => {}
+            hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar(_) => {}
         }
 
         // Check if the match is exhaustive.
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
index 251c6b4b6da..1376344cfda 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
@@ -325,6 +325,11 @@ impl<'tcx> ConstToPat<'tcx> {
                 // `PartialEq::eq` on it.
                 return Err(FallbackToConstRef);
             }
+            ty::FnDef(..) => {
+                self.saw_const_match_error.set(true);
+                tcx.sess.emit_err(InvalidPattern { span, non_sm_ty: ty });
+                PatKind::Wild
+            }
             ty::Adt(adt_def, _) if !self.type_marked_structural(ty) => {
                 debug!("adt_def {:?} has !type_marked_structural for cv.ty: {:?}", adt_def, ty,);
                 self.saw_const_match_error.set(true);
@@ -440,7 +445,7 @@ impl<'tcx> ConstToPat<'tcx> {
                     }
                 }
             },
-            ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::FnDef(..) => PatKind::Constant {
+            ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) => PatKind::Constant {
                 value: mir::ConstantKind::Ty(ty::Const::new_value(tcx, cv, ty)),
             },
             ty::FnPtr(..) | ty::RawPtr(..) => unreachable!(),
diff --git a/compiler/rustc_mir_build/src/thir/print.rs b/compiler/rustc_mir_build/src/thir/print.rs
index 903dbeeadfa..3b6276cfeb0 100644
--- a/compiler/rustc_mir_build/src/thir/print.rs
+++ b/compiler/rustc_mir_build/src/thir/print.rs
@@ -321,7 +321,7 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
                 print_indented!(self, format!("pat: {:?}", pat), depth_lvl + 1);
                 print_indented!(self, "}", depth_lvl);
             }
-            Match { scrutinee, arms } => {
+            Match { scrutinee, arms, .. } => {
                 print_indented!(self, "Match {", depth_lvl);
                 print_indented!(self, "scrutinee:", depth_lvl + 1);
                 self.print_expr(*scrutinee, depth_lvl + 2);
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 4f9b362e237..197b335bdec 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -10,7 +10,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, IntoDiagnosticArg, MultiSpan};
 use rustc_feature::{AttributeDuplicates, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::LocalModDefId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{
     self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID, CRATE_OWNER_ID,
@@ -2465,10 +2465,10 @@ fn check_non_exported_macro_for_invalid_attrs(tcx: TyCtxt<'_>, item: &Item<'_>)
     }
 }
 
-fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     let check_attr_visitor = &mut CheckAttrVisitor { tcx, abort: Cell::new(false) };
     tcx.hir().visit_item_likes_in_module(module_def_id, check_attr_visitor);
-    if module_def_id.is_top_level_module() {
+    if module_def_id.to_local_def_id().is_top_level_module() {
         check_attr_visitor.check_attributes(CRATE_HIR_ID, DUMMY_SP, Target::Mod, None);
         check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs());
     }
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index e70817d7b7c..8437e9a40e2 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -9,7 +9,7 @@
 
 use rustc_attr as attr;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::query::Providers;
@@ -45,7 +45,7 @@ impl NonConstExpr {
 
             Self::Loop(ForLoop) | Self::Match(ForLoopDesugar) => &[sym::const_for],
 
-            Self::Match(TryDesugar) => &[sym::const_try],
+            Self::Match(TryDesugar(_)) => &[sym::const_try],
 
             // All other expressions are allowed.
             Self::Loop(Loop | While) | Self::Match(Normal | FormatArgs) => &[],
@@ -55,7 +55,7 @@ impl NonConstExpr {
     }
 }
 
-fn check_mod_const_bodies(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_const_bodies(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     let mut vis = CheckConstVisitor::new(tcx);
     tcx.hir().visit_item_likes_in_module(module_def_id, &mut vis);
 }
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 2936c8fac7d..d1c3bcf3839 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -8,7 +8,7 @@ use rustc_data_structures::unord::UnordSet;
 use rustc_errors::MultiSpan;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Node, PatKind, TyKind};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
@@ -944,7 +944,7 @@ impl<'tcx> DeadVisitor<'tcx> {
     }
 }
 
-fn check_mod_deathness(tcx: TyCtxt<'_>, module: LocalDefId) {
+fn check_mod_deathness(tcx: TyCtxt<'_>, module: LocalModDefId) {
     let (live_symbols, ignored_derived_traits) = tcx.live_symbols_and_ignored_derived_traits(());
     let mut visitor = DeadVisitor { tcx, live_symbols, ignored_derived_traits };
 
@@ -969,7 +969,7 @@ fn check_mod_deathness(tcx: TyCtxt<'_>, module: LocalDefId) {
 
         if !live_symbols.contains(&item.owner_id.def_id) {
             let parent = tcx.local_parent(item.owner_id.def_id);
-            if parent != module && !live_symbols.contains(&parent) {
+            if parent != module.to_local_def_id() && !live_symbols.contains(&parent) {
                 // We already have diagnosed something.
                 continue;
             }
diff --git a/compiler/rustc_passes/src/loops.rs b/compiler/rustc_passes/src/loops.rs
index 7c64df6a50e..0aaf85086e4 100644
--- a/compiler/rustc_passes/src/loops.rs
+++ b/compiler/rustc_passes/src/loops.rs
@@ -1,7 +1,7 @@
 use Context::*;
 
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::LocalModDefId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Destination, Movability, Node};
 use rustc_middle::hir::map::Map;
@@ -34,7 +34,7 @@ struct CheckLoopVisitor<'a, 'hir> {
     cx: Context,
 }
 
-fn check_mod_loops(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_loops(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
         &mut CheckLoopVisitor { sess: &tcx.sess, hir_map: tcx.hir(), cx: Normal },
diff --git a/compiler/rustc_passes/src/naked_functions.rs b/compiler/rustc_passes/src/naked_functions.rs
index 769b389009b..7f36c59ad98 100644
--- a/compiler/rustc_passes/src/naked_functions.rs
+++ b/compiler/rustc_passes/src/naked_functions.rs
@@ -3,7 +3,7 @@
 use rustc_ast::InlineAsmOptions;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::{ExprKind, InlineAsmOperand, StmtKind};
 use rustc_middle::query::Providers;
@@ -23,7 +23,7 @@ pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { check_mod_naked_functions, ..*providers };
 }
 
-fn check_mod_naked_functions(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_naked_functions(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     let items = tcx.hir_module_items(module_def_id);
     for def_id in items.definitions() {
         if !matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn) {
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index bd2336410b9..9c265e8ec11 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -9,7 +9,7 @@ use rustc_attr::{
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
+use rustc_hir::def_id::{LocalDefId, LocalModDefId, CRATE_DEF_ID};
 use rustc_hir::hir_id::CRATE_HIR_ID;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{FieldDef, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
@@ -682,7 +682,7 @@ fn stability_index(tcx: TyCtxt<'_>, (): ()) -> Index {
 
 /// Cross-references the feature names of unstable APIs with enabled
 /// features and possibly prints errors.
-fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     tcx.hir().visit_item_likes_in_module(module_def_id, &mut Checker { tcx });
 }
 
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 30a4235d371..0eb344ba690 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -20,7 +20,7 @@ use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
+use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId, CRATE_DEF_ID};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{AssocItemKind, ForeignItemKind, HirIdSet, ItemId, Node, PatKind};
 use rustc_middle::bug;
@@ -382,8 +382,9 @@ impl VisibilityLike for EffectiveVisibility {
     ) -> Self {
         let effective_vis =
             find.effective_visibilities.effective_vis(def_id).copied().unwrap_or_else(|| {
-                let private_vis =
-                    ty::Visibility::Restricted(find.tcx.parent_module_from_def_id(def_id));
+                let private_vis = ty::Visibility::Restricted(
+                    find.tcx.parent_module_from_def_id(def_id).to_local_def_id(),
+                );
                 EffectiveVisibility::from_vis(private_vis)
             });
 
@@ -412,7 +413,7 @@ struct EmbargoVisitor<'tcx> {
     /// pub macro m() {
     ///     n::p::f()
     /// }
-    macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
+    macro_reachable: FxHashSet<(LocalModDefId, LocalModDefId)>,
     /// Preliminary pass for marking all underlying types of `impl Trait`s as reachable.
     impl_trait_pass: bool,
     /// Has something changed in the level map?
@@ -449,7 +450,9 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         max_vis: Option<ty::Visibility>,
         level: Level,
     ) {
-        let private_vis = ty::Visibility::Restricted(self.tcx.parent_module_from_def_id(def_id));
+        // FIXME(typed_def_id): Make `Visibility::Restricted` use a `LocalModDefId` by default.
+        let private_vis =
+            ty::Visibility::Restricted(self.tcx.parent_module_from_def_id(def_id).into());
         if max_vis != Some(private_vis) {
             self.changed |= self.effective_visibilities.update(
                 def_id,
@@ -508,6 +511,8 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
             return;
         }
+        // FIXME(typed_def_id): Introduce checked constructors that check def_kind.
+        let macro_module_def_id = LocalModDefId::new_unchecked(macro_module_def_id);
 
         if self.effective_visibilities.public_at_level(local_def_id).is_none() {
             return;
@@ -519,10 +524,10 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         loop {
             let changed_reachability =
                 self.update_macro_reachable(module_def_id, macro_module_def_id, macro_ev);
-            if changed_reachability || module_def_id == CRATE_DEF_ID {
+            if changed_reachability || module_def_id == LocalModDefId::CRATE_DEF_ID {
                 break;
             }
-            module_def_id = self.tcx.local_parent(module_def_id);
+            module_def_id = LocalModDefId::new_unchecked(self.tcx.local_parent(module_def_id));
         }
     }
 
@@ -530,8 +535,8 @@ impl<'tcx> EmbargoVisitor<'tcx> {
     /// module. Returns `true` if the level has changed.
     fn update_macro_reachable(
         &mut self,
-        module_def_id: LocalDefId,
-        defining_mod: LocalDefId,
+        module_def_id: LocalModDefId,
+        defining_mod: LocalModDefId,
         macro_ev: EffectiveVisibility,
     ) -> bool {
         if self.macro_reachable.insert((module_def_id, defining_mod)) {
@@ -544,8 +549,8 @@ impl<'tcx> EmbargoVisitor<'tcx> {
 
     fn update_macro_reachable_mod(
         &mut self,
-        module_def_id: LocalDefId,
-        defining_mod: LocalDefId,
+        module_def_id: LocalModDefId,
+        defining_mod: LocalModDefId,
         macro_ev: EffectiveVisibility,
     ) {
         let module = self.tcx.hir().get_module(module_def_id).0;
@@ -560,7 +565,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
                 macro_ev,
             );
         }
-        for child in self.tcx.module_children_local(module_def_id) {
+        for child in self.tcx.module_children_local(module_def_id.to_local_def_id()) {
             // FIXME: Use module children for the logic above too.
             if !child.reexport_chain.is_empty()
                 && child.vis.is_accessible_from(defining_mod, self.tcx)
@@ -577,7 +582,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         def_id: LocalDefId,
         def_kind: DefKind,
         vis: ty::Visibility,
-        module: LocalDefId,
+        module: LocalModDefId,
         macro_ev: EffectiveVisibility,
     ) {
         self.update(def_id, macro_ev, Level::Reachable);
@@ -608,7 +613,11 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             // the module, however may be reachable.
             DefKind::Mod => {
                 if vis.is_accessible_from(module, self.tcx) {
-                    self.update_macro_reachable(def_id, module, macro_ev);
+                    self.update_macro_reachable(
+                        LocalModDefId::new_unchecked(def_id),
+                        module,
+                        macro_ev,
+                    );
                 }
             }
 
@@ -892,7 +901,7 @@ fn vis_to_string<'tcx>(def_id: LocalDefId, vis: ty::Visibility, tcx: TyCtxt<'tcx
         ty::Visibility::Restricted(restricted_id) => {
             if restricted_id.is_top_level_module() {
                 "pub(crate)".to_string()
-            } else if restricted_id == tcx.parent_module_from_def_id(def_id) {
+            } else if restricted_id == tcx.parent_module_from_def_id(def_id).to_local_def_id() {
                 "pub(self)".to_string()
             } else {
                 format!("pub({})", tcx.item_name(restricted_id.to_def_id()))
@@ -1800,7 +1809,7 @@ impl SearchInterfaceForPrivateItemsVisitor<'_> {
             let vis_descr = match vis {
                 ty::Visibility::Public => "public",
                 ty::Visibility::Restricted(vis_def_id) => {
-                    if vis_def_id == self.tcx.parent_module(hir_id) {
+                    if vis_def_id == self.tcx.parent_module(hir_id).to_local_def_id() {
                         "private"
                     } else if vis_def_id.is_top_level_module() {
                         "crate-private"
@@ -2196,7 +2205,7 @@ fn local_visibility(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Visibility {
                     kind: hir::ItemKind::Use(_, hir::UseKind::ListStem)
                         | hir::ItemKind::OpaqueTy(..),
                     ..
-                }) => ty::Visibility::Restricted(tcx.parent_module(hir_id)),
+                }) => ty::Visibility::Restricted(tcx.parent_module(hir_id).to_local_def_id()),
                 // Visibilities of trait impl items are inherited from their traits
                 // and are not filled in resolve.
                 Node::ImplItem(impl_item) => {
@@ -2224,18 +2233,25 @@ fn local_visibility(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Visibility {
     }
 }
 
-fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     // Check privacy of names not checked in previous compilation stages.
-    let mut visitor =
-        NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
+    let mut visitor = NamePrivacyVisitor {
+        tcx,
+        maybe_typeck_results: None,
+        current_item: module_def_id.to_local_def_id(),
+    };
     let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
 
     intravisit::walk_mod(&mut visitor, module, hir_id);
 
     // Check privacy of explicitly written types and traits as well as
     // inferred types of expressions and patterns.
-    let mut visitor =
-        TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
+    let mut visitor = TypePrivacyVisitor {
+        tcx,
+        maybe_typeck_results: None,
+        current_item: module_def_id.to_local_def_id(),
+        span,
+    };
     intravisit::walk_mod(&mut visitor, module, hir_id);
 }
 
diff --git a/compiler/rustc_smir/src/lib.rs b/compiler/rustc_smir/src/lib.rs
index 6ebba56c76d..8cb533c8d67 100644
--- a/compiler/rustc_smir/src/lib.rs
+++ b/compiler/rustc_smir/src/lib.rs
@@ -11,7 +11,6 @@
     test(attr(allow(unused_variables), deny(warnings)))
 )]
 #![cfg_attr(not(feature = "default"), feature(rustc_private))]
-#![feature(local_key_cell_methods)]
 #![feature(ptr_metadata)]
 #![feature(type_alias_impl_trait)] // Used to define opaque types.
 #![feature(intra_doc_pointers)]
diff --git a/compiler/rustc_smir/src/stable_mir/mod.rs b/compiler/rustc_smir/src/stable_mir/mod.rs
index a74975cefc2..19061742b64 100644
--- a/compiler/rustc_smir/src/stable_mir/mod.rs
+++ b/compiler/rustc_smir/src/stable_mir/mod.rs
@@ -85,6 +85,22 @@ pub fn all_local_items() -> CrateItems {
     with(|cx| cx.all_local_items())
 }
 
+pub fn all_trait_decls() -> TraitDecls {
+    with(|cx| cx.all_trait_decls())
+}
+
+pub fn trait_decl(trait_def: &TraitDef) -> TraitDecl {
+    with(|cx| cx.trait_decl(trait_def))
+}
+
+pub fn all_trait_impls() -> ImplTraitDecls {
+    with(|cx| cx.all_trait_impls())
+}
+
+pub fn trait_impl(trait_impl: &ImplDef) -> ImplTrait {
+    with(|cx| cx.trait_impl(trait_impl))
+}
+
 pub trait Context {
     fn entry_fn(&mut self) -> Option<CrateItem>;
     /// Retrieve all items of the local crate that have a MIR associated with them.
diff --git a/compiler/rustc_span/src/def_id.rs b/compiler/rustc_span/src/def_id.rs
index f65a6aa4fb2..595babc26ae 100644
--- a/compiler/rustc_span/src/def_id.rs
+++ b/compiler/rustc_span/src/def_id.rs
@@ -28,10 +28,16 @@ impl CrateNum {
         CrateNum::from_usize(x)
     }
 
+    // FIXME(typed_def_id): Replace this with `as_mod_def_id`.
     #[inline]
     pub fn as_def_id(self) -> DefId {
         DefId { krate: self, index: CRATE_DEF_INDEX }
     }
+
+    #[inline]
+    pub fn as_mod_def_id(self) -> ModDefId {
+        ModDefId::new_unchecked(DefId { krate: self, index: CRATE_DEF_INDEX })
+    }
 }
 
 impl fmt::Display for CrateNum {
@@ -485,3 +491,92 @@ impl<CTX: HashStableContext> ToStableHashKey<CTX> for CrateNum {
         self.as_def_id().to_stable_hash_key(hcx)
     }
 }
+
+macro_rules! typed_def_id {
+    ($Name:ident, $LocalName:ident) => {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Encodable, Decodable, HashStable_Generic)]
+        pub struct $Name(DefId);
+
+        impl $Name {
+            pub const fn new_unchecked(def_id: DefId) -> Self {
+                Self(def_id)
+            }
+
+            pub fn to_def_id(self) -> DefId {
+                self.into()
+            }
+
+            pub fn is_local(self) -> bool {
+                self.0.is_local()
+            }
+
+            pub fn as_local(self) -> Option<$LocalName> {
+                self.0.as_local().map($LocalName::new_unchecked)
+            }
+        }
+
+        impl From<$LocalName> for $Name {
+            fn from(local: $LocalName) -> Self {
+                Self(local.0.to_def_id())
+            }
+        }
+
+        impl From<$Name> for DefId {
+            fn from(typed: $Name) -> Self {
+                typed.0
+            }
+        }
+
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Encodable, Decodable, HashStable_Generic)]
+        pub struct $LocalName(LocalDefId);
+
+        impl !Ord for $LocalName {}
+        impl !PartialOrd for $LocalName {}
+
+        impl $LocalName {
+            pub const fn new_unchecked(def_id: LocalDefId) -> Self {
+                Self(def_id)
+            }
+
+            pub fn to_def_id(self) -> DefId {
+                self.0.into()
+            }
+
+            pub fn to_local_def_id(self) -> LocalDefId {
+                self.0
+            }
+        }
+
+        impl From<$LocalName> for LocalDefId {
+            fn from(typed: $LocalName) -> Self {
+                typed.0
+            }
+        }
+
+        impl From<$LocalName> for DefId {
+            fn from(typed: $LocalName) -> Self {
+                typed.0.into()
+            }
+        }
+    };
+}
+
+// N.B.: when adding new typed `DefId`s update the corresponding trait impls in
+// `rustc_middle::dep_graph::def_node` for `DepNodeParams`.
+typed_def_id! { ModDefId, LocalModDefId }
+
+impl LocalModDefId {
+    pub const CRATE_DEF_ID: Self = Self::new_unchecked(CRATE_DEF_ID);
+}
+
+impl ModDefId {
+    pub fn is_top_level_module(self) -> bool {
+        self.0.is_top_level_module()
+    }
+}
+
+impl LocalModDefId {
+    pub fn is_top_level_module(self) -> bool {
+        self.0.is_top_level_module()
+    }
+}
diff --git a/compiler/rustc_target/src/spec/loongarch64_unknown_none.rs b/compiler/rustc_target/src/spec/loongarch64_unknown_none.rs
index 209d481d6f8..dbc96d68eae 100644
--- a/compiler/rustc_target/src/spec/loongarch64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/loongarch64_unknown_none.rs
@@ -10,7 +10,8 @@ pub fn target() -> Target {
         options: TargetOptions {
             cpu: "generic".into(),
             features: "+f,+d".into(),
-            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::No),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
             llvm_abiname: "lp64d".into(),
             max_atomic_width: Some(64),
             relocation_model: RelocModel::Static,
diff --git a/compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs b/compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs
index f444a7f24bb..c4d5c7bc44c 100644
--- a/compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs
+++ b/compiler/rustc_target/src/spec/loongarch64_unknown_none_softfloat.rs
@@ -11,7 +11,8 @@ pub fn target() -> Target {
             cpu: "generic".into(),
             features: "-f,-d".into(),
             abi: "softfloat".into(),
-            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::No),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
             llvm_abiname: "lp64s".into(),
             max_atomic_width: Some(64),
             relocation_model: RelocModel::Static,
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 6ada4e49083..af2b96ccb51 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -338,7 +338,7 @@ impl LinkerFlavor {
             || stem == "clang++"
             || stem.ends_with("-clang++")
         {
-            (Some(Cc::Yes), None)
+            (Some(Cc::Yes), Some(Lld::No))
         } else if stem == "wasm-ld"
             || stem.ends_with("-wasm-ld")
             || stem == "ld.lld"
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index 3750b3750bf..36194f973b5 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -281,23 +281,27 @@ pub(super) trait GoalKind<'tcx>:
     ) -> QueryResult<'tcx>;
 
     /// Consider (possibly several) candidates to upcast or unsize a type to another
-    /// type.
-    ///
-    /// The most common forms of unsizing are array to slice, and concrete (Sized)
-    /// type into a `dyn Trait`. ADTs and Tuples can also have their final field
-    /// unsized if it's generic.
-    ///
-    /// `dyn Trait1` can be unsized to `dyn Trait2` if they are the same trait, or
-    /// if `Trait2` is a (transitive) supertrait of `Trait2`.
+    /// type, excluding the coercion of a sized type into a `dyn Trait`.
     ///
     /// We return the `BuiltinImplSource` for each candidate as it is needed
     /// for unsize coercion in hir typeck and because it is difficult to
     /// otherwise recompute this for codegen. This is a bit of a mess but the
     /// easiest way to maintain the existing behavior for now.
-    fn consider_builtin_unsize_candidates(
+    fn consider_structural_builtin_unsize_candidates(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<(CanonicalResponse<'tcx>, BuiltinImplSource)>;
+
+    /// Consider the `Unsize` candidate corresponding to coercing a sized type
+    /// into a `dyn Trait`.
+    ///
+    /// This is computed separately from the rest of the `Unsize` candidates
+    /// since it is only done once per self type, and not once per
+    /// *normalization step* (in `assemble_candidates_via_self_ty`).
+    fn consider_unsize_to_dyn_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
@@ -312,6 +316,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
 
         let mut candidates = self.assemble_candidates_via_self_ty(goal, 0);
 
+        self.assemble_unsize_to_dyn_candidate(goal, &mut candidates);
+
         self.assemble_blanket_impl_candidates(goal, &mut candidates);
 
         self.assemble_param_env_candidates(goal, &mut candidates);
@@ -530,6 +536,23 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         }
     }
 
+    fn assemble_unsize_to_dyn_candidate<G: GoalKind<'tcx>>(
+        &mut self,
+        goal: Goal<'tcx, G>,
+        candidates: &mut Vec<Candidate<'tcx>>,
+    ) {
+        let tcx = self.tcx();
+        if tcx.lang_items().unsize_trait() == Some(goal.predicate.trait_def_id(tcx)) {
+            match G::consider_unsize_to_dyn_candidate(self, goal) {
+                Ok(result) => candidates.push(Candidate {
+                    source: CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
+                    result,
+                }),
+                Err(NoSolution) => (),
+            }
+        }
+    }
+
     fn assemble_blanket_impl_candidates<G: GoalKind<'tcx>>(
         &mut self,
         goal: Goal<'tcx, G>,
@@ -610,7 +633,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         // There may be multiple unsize candidates for a trait with several supertraits:
         // `trait Foo: Bar<A> + Bar<B>` and `dyn Foo: Unsize<dyn Bar<_>>`
         if lang_items.unsize_trait() == Some(trait_def_id) {
-            for (result, source) in G::consider_builtin_unsize_candidates(self, goal) {
+            for (result, source) in G::consider_structural_builtin_unsize_candidates(self, goal) {
                 candidates.push(Candidate { source: CandidateSource::BuiltinImpl(source), result });
             }
         }
@@ -826,6 +849,11 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             ty::Dynamic(bounds, ..) => bounds,
         };
 
+        // Do not consider built-in object impls for non-object-safe types.
+        if bounds.principal_def_id().is_some_and(|def_id| !tcx.check_is_object_safe(def_id)) {
+            return;
+        }
+
         // Consider all of the auto-trait and projection bounds, which don't
         // need to be recorded as a `BuiltinImplSource::Object` since they don't
         // really have a vtable base...
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index e1980f4d7bb..e47e228774e 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -1,4 +1,4 @@
-use crate::traits::specialization_graph;
+use crate::traits::{check_args_compatible, specialization_graph};
 
 use super::assembly::{self, structural_traits};
 use super::EvalCtxt;
@@ -190,11 +190,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
                 return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
             };
 
-            if !assoc_def.item.defaultness(tcx).has_value() {
-                let guar = tcx.sess.delay_span_bug(
-                    tcx.def_span(assoc_def.item.def_id),
-                    "missing value for assoc item in impl",
-                );
+            let error_response = |ecx: &mut EvalCtxt<'_, 'tcx>, reason| {
+                let guar = tcx.sess.delay_span_bug(tcx.def_span(assoc_def.item.def_id), reason);
                 let error_term = match assoc_def.item.kind {
                     ty::AssocKind::Const => ty::Const::new_error(
                         tcx,
@@ -208,7 +205,11 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
                 };
                 ecx.eq(goal.param_env, goal.predicate.term, error_term)
                     .expect("expected goal term to be fully unconstrained");
-                return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes);
+                ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+            };
+
+            if !assoc_def.item.defaultness(tcx).has_value() {
+                return error_response(ecx, "missing value for assoc item in impl");
             }
 
             // Getting the right args here is complex, e.g. given:
@@ -233,6 +234,13 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
                 assoc_def.defining_node,
             );
 
+            if !check_args_compatible(tcx, assoc_def.item, args) {
+                return error_response(
+                    ecx,
+                    "associated item has mismatched generic item arguments",
+                );
+            }
+
             // Finally we construct the actual value of the associated type.
             let term = match assoc_def.item.kind {
                 ty::AssocKind::Type => tcx.type_of(assoc_def.item.def_id).map_bound(|ty| ty.into()),
@@ -497,7 +505,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
         )
     }
 
-    fn consider_builtin_unsize_candidates(
+    fn consider_unsize_to_dyn_candidate(
+        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        bug!("`Unsize` does not have an associated type: {:?}", goal)
+    }
+
+    fn consider_structural_builtin_unsize_candidates(
         _ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<(CanonicalResponse<'tcx>, BuiltinImplSource)> {
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index ee6f1686b82..8685f3100a8 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -423,7 +423,55 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         ecx.evaluate_added_goals_and_make_canonical_response(certainty)
     }
 
-    fn consider_builtin_unsize_candidates(
+    fn consider_unsize_to_dyn_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        ecx.probe(|_| CandidateKind::UnsizeAssembly).enter(|ecx| {
+            let a_ty = goal.predicate.self_ty();
+            // We need to normalize the b_ty since it's destructured as a `dyn Trait`.
+            let Some(b_ty) =
+                ecx.try_normalize_ty(goal.param_env, goal.predicate.trait_ref.args.type_at(1))?
+            else {
+                return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::OVERFLOW);
+            };
+
+            let ty::Dynamic(b_data, b_region, ty::Dyn) = *b_ty.kind() else {
+                return Err(NoSolution);
+            };
+
+            let tcx = ecx.tcx();
+
+            // Can only unsize to an object-safe trait.
+            if b_data.principal_def_id().is_some_and(|def_id| !tcx.check_is_object_safe(def_id)) {
+                return Err(NoSolution);
+            }
+
+            // Check that the type implements all of the predicates of the trait object.
+            // (i.e. the principal, all of the associated types match, and any auto traits)
+            ecx.add_goals(b_data.iter().map(|pred| goal.with(tcx, pred.with_self_ty(tcx, a_ty))));
+
+            // The type must be `Sized` to be unsized.
+            if let Some(sized_def_id) = tcx.lang_items().sized_trait() {
+                ecx.add_goal(goal.with(tcx, ty::TraitRef::new(tcx, sized_def_id, [a_ty])));
+            } else {
+                return Err(NoSolution);
+            }
+
+            // The type must outlive the lifetime of the `dyn` we're unsizing into.
+            ecx.add_goal(goal.with(tcx, ty::OutlivesPredicate(a_ty, b_region)));
+            ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+        })
+    }
+
+    /// ```ignore (builtin impl example)
+    /// trait Trait {
+    ///     fn foo(&self);
+    /// }
+    /// // results in the following builtin impl
+    /// impl<'a, T: Trait + 'a> Unsize<dyn Trait + 'a> for T {}
+    /// ```
+    fn consider_structural_builtin_unsize_candidates(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<(CanonicalResponse<'tcx>, BuiltinImplSource)> {
@@ -468,11 +516,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
                     goal, a_data, a_region, b_data, b_region,
                 ),
 
-                // `T` -> `dyn Trait` unsizing
-                (_, &ty::Dynamic(b_data, b_region, ty::Dyn)) => result_to_single(
-                    ecx.consider_builtin_unsize_to_dyn(goal, b_data, b_region),
-                    BuiltinImplSource::Misc,
-                ),
+                // `T` -> `dyn Trait` unsizing is handled separately in `consider_unsize_to_dyn_candidate`
+                (_, &ty::Dynamic(..)) => vec![],
 
                 // `[T; N]` -> `[T]` unsizing
                 (&ty::Array(a_elem_ty, ..), &ty::Slice(b_elem_ty)) => result_to_single(
@@ -552,16 +597,18 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             self.walk_vtable(
                 a_principal.with_self_ty(tcx, a_ty),
                 |ecx, new_a_principal, _, vtable_vptr_slot| {
-                    if let Ok(resp) = ecx.consider_builtin_upcast_to_principal(
-                        goal,
-                        a_data,
-                        a_region,
-                        b_data,
-                        b_region,
-                        Some(new_a_principal.map_bound(|trait_ref| {
-                            ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref)
-                        })),
-                    ) {
+                    if let Ok(resp) = ecx.probe_candidate("dyn upcast").enter(|ecx| {
+                        ecx.consider_builtin_upcast_to_principal(
+                            goal,
+                            a_data,
+                            a_region,
+                            b_data,
+                            b_region,
+                            Some(new_a_principal.map_bound(|trait_ref| {
+                                ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref)
+                            })),
+                        )
+                    }) {
                         responses
                             .push((resp, BuiltinImplSource::TraitUpcasting { vtable_vptr_slot }));
                     }
@@ -572,43 +619,6 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         responses
     }
 
-    /// ```ignore (builtin impl example)
-    /// trait Trait {
-    ///     fn foo(&self);
-    /// }
-    /// // results in the following builtin impl
-    /// impl<'a, T: Trait + 'a> Unsize<dyn Trait + 'a> for T {}
-    /// ```
-    fn consider_builtin_unsize_to_dyn(
-        &mut self,
-        goal: Goal<'tcx, (Ty<'tcx>, Ty<'tcx>)>,
-        b_data: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
-        b_region: ty::Region<'tcx>,
-    ) -> QueryResult<'tcx> {
-        let tcx = self.tcx();
-        let Goal { predicate: (a_ty, _b_ty), .. } = goal;
-
-        // Can only unsize to an object-safe trait
-        if b_data.principal_def_id().is_some_and(|def_id| !tcx.check_is_object_safe(def_id)) {
-            return Err(NoSolution);
-        }
-
-        // Check that the type implements all of the predicates of the trait object.
-        // (i.e. the principal, all of the associated types match, and any auto traits)
-        self.add_goals(b_data.iter().map(|pred| goal.with(tcx, pred.with_self_ty(tcx, a_ty))));
-
-        // The type must be `Sized` to be unsized.
-        if let Some(sized_def_id) = tcx.lang_items().sized_trait() {
-            self.add_goal(goal.with(tcx, ty::TraitRef::new(tcx, sized_def_id, [a_ty])));
-        } else {
-            return Err(NoSolution);
-        }
-
-        // The type must outlive the lifetime of the `dyn` we're unsizing into.
-        self.add_goal(goal.with(tcx, ty::OutlivesPredicate(a_ty, b_region)));
-        self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
-    }
-
     fn consider_builtin_upcast_to_principal(
         &mut self,
         goal: Goal<'tcx, (Ty<'tcx>, Ty<'tcx>)>,
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index e56af586ed8..5746781ae35 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -7,7 +7,7 @@
 use crate::infer::outlives::env::OutlivesEnvironment;
 use crate::infer::InferOk;
 use crate::traits::outlives_bounds::InferCtxtExt as _;
-use crate::traits::select::IntercrateAmbiguityCause;
+use crate::traits::select::{IntercrateAmbiguityCause, TreatInductiveCycleAs};
 use crate::traits::util::impl_subject_and_oblig;
 use crate::traits::SkipLeakCheck;
 use crate::traits::{
@@ -24,6 +24,7 @@ use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitor};
+use rustc_session::lint::builtin::COINDUCTIVE_OVERLAP_IN_COHERENCE;
 use rustc_span::symbol::sym;
 use rustc_span::DUMMY_SP;
 use std::fmt::Debug;
@@ -151,14 +152,16 @@ fn with_fresh_ty_vars<'cx, 'tcx>(
             .predicates_of(impl_def_id)
             .instantiate(tcx, impl_args)
             .iter()
-            .map(|(c, _)| c.as_predicate())
+            .map(|(c, s)| (c.as_predicate(), s))
             .collect(),
     };
 
-    let InferOk { value: mut header, obligations } =
-        selcx.infcx.at(&ObligationCause::dummy(), param_env).normalize(header);
+    let InferOk { value: mut header, obligations } = selcx
+        .infcx
+        .at(&ObligationCause::dummy_with_span(tcx.def_span(impl_def_id)), param_env)
+        .normalize(header);
 
-    header.predicates.extend(obligations.into_iter().map(|o| o.predicate));
+    header.predicates.extend(obligations.into_iter().map(|o| (o.predicate, o.cause.span)));
     header
 }
 
@@ -207,16 +210,76 @@ fn overlap<'tcx>(
     let equate_obligations = equate_impl_headers(selcx.infcx, &impl1_header, &impl2_header)?;
     debug!("overlap: unification check succeeded");
 
-    if overlap_mode.use_implicit_negative()
-        && impl_intersection_has_impossible_obligation(
-            selcx,
-            param_env,
-            &impl1_header,
-            impl2_header,
-            equate_obligations,
-        )
-    {
-        return None;
+    if overlap_mode.use_implicit_negative() {
+        for mode in [TreatInductiveCycleAs::Ambig, TreatInductiveCycleAs::Recur] {
+            if let Some(failing_obligation) = selcx.with_treat_inductive_cycle_as(mode, |selcx| {
+                impl_intersection_has_impossible_obligation(
+                    selcx,
+                    param_env,
+                    &impl1_header,
+                    &impl2_header,
+                    &equate_obligations,
+                )
+            }) {
+                if matches!(mode, TreatInductiveCycleAs::Recur) {
+                    let first_local_impl = impl1_header
+                        .impl_def_id
+                        .as_local()
+                        .or(impl2_header.impl_def_id.as_local())
+                        .expect("expected one of the impls to be local");
+                    infcx.tcx.struct_span_lint_hir(
+                        COINDUCTIVE_OVERLAP_IN_COHERENCE,
+                        infcx.tcx.local_def_id_to_hir_id(first_local_impl),
+                        infcx.tcx.def_span(first_local_impl),
+                        format!(
+                            "implementations {} will conflict in the future",
+                            match impl1_header.trait_ref {
+                                Some(trait_ref) => {
+                                    let trait_ref = infcx.resolve_vars_if_possible(trait_ref);
+                                    format!(
+                                        "of `{}` for `{}`",
+                                        trait_ref.print_only_trait_path(),
+                                        trait_ref.self_ty()
+                                    )
+                                }
+                                None => format!(
+                                    "for `{}`",
+                                    infcx.resolve_vars_if_possible(impl1_header.self_ty)
+                                ),
+                            },
+                        ),
+                        |lint| {
+                            lint.note(
+                                "impls that are not considered to overlap may be considered to \
+                                overlap in the future",
+                            )
+                            .span_label(
+                                infcx.tcx.def_span(impl1_header.impl_def_id),
+                                "the first impl is here",
+                            )
+                            .span_label(
+                                infcx.tcx.def_span(impl2_header.impl_def_id),
+                                "the second impl is here",
+                            );
+                            if !failing_obligation.cause.span.is_dummy() {
+                                lint.span_label(
+                                    failing_obligation.cause.span,
+                                    format!(
+                                        "`{}` may be considered to hold in future releases, \
+                                        causing the impls to overlap",
+                                        infcx
+                                            .resolve_vars_if_possible(failing_obligation.predicate)
+                                    ),
+                                );
+                            }
+                            lint
+                        },
+                    );
+                }
+
+                return None;
+            }
+        }
     }
 
     // We toggle the `leak_check` by using `skip_leak_check` when constructing the
@@ -284,40 +347,30 @@ fn impl_intersection_has_impossible_obligation<'cx, 'tcx>(
     selcx: &mut SelectionContext<'cx, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     impl1_header: &ty::ImplHeader<'tcx>,
-    impl2_header: ty::ImplHeader<'tcx>,
-    obligations: PredicateObligations<'tcx>,
-) -> bool {
+    impl2_header: &ty::ImplHeader<'tcx>,
+    obligations: &PredicateObligations<'tcx>,
+) -> Option<PredicateObligation<'tcx>> {
     let infcx = selcx.infcx;
 
-    let obligation_guaranteed_to_fail = move |obligation: &PredicateObligation<'tcx>| {
-        if infcx.next_trait_solver() {
-            infcx.evaluate_obligation(obligation).map_or(false, |result| !result.may_apply())
-        } else {
-            // We use `evaluate_root_obligation` to correctly track
-            // intercrate ambiguity clauses. We do not need this in the
-            // new solver.
-            selcx.evaluate_root_obligation(obligation).map_or(
-                false, // Overflow has occurred, and treat the obligation as possibly holding.
-                |result| !result.may_apply(),
-            )
-        }
-    };
-
-    let opt_failing_obligation = [&impl1_header.predicates, &impl2_header.predicates]
+    [&impl1_header.predicates, &impl2_header.predicates]
         .into_iter()
         .flatten()
-        .map(|&predicate| {
-            Obligation::new(infcx.tcx, ObligationCause::dummy(), param_env, predicate)
+        .map(|&(predicate, span)| {
+            Obligation::new(infcx.tcx, ObligationCause::dummy_with_span(span), param_env, predicate)
+        })
+        .chain(obligations.into_iter().cloned())
+        .find(|obligation: &PredicateObligation<'tcx>| {
+            if infcx.next_trait_solver() {
+                infcx.evaluate_obligation(obligation).map_or(false, |result| !result.may_apply())
+            } else {
+                // We use `evaluate_root_obligation` to correctly track intercrate
+                // ambiguity clauses. We cannot use this in the new solver.
+                selcx.evaluate_root_obligation(obligation).map_or(
+                    false, // Overflow has occurred, and treat the obligation as possibly holding.
+                    |result| !result.may_apply(),
+                )
+            }
         })
-        .chain(obligations)
-        .find(obligation_guaranteed_to_fail);
-
-    if let Some(failing_obligation) = opt_failing_obligation {
-        debug!("overlap: obligation unsatisfiable {:?}", failing_obligation);
-        true
-    } else {
-        false
-    }
 }
 
 /// Check if both impls can be satisfied by a common type by considering whether
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index d071cf76fd3..5e075984238 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -2700,7 +2700,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             | ObligationCauseCode::MatchImpl(..)
             | ObligationCauseCode::ReturnType
             | ObligationCauseCode::ReturnValue(_)
-            | ObligationCauseCode::BlockTailExpression(_)
+            | ObligationCauseCode::BlockTailExpression(..)
             | ObligationCauseCode::AwaitableExpr(_)
             | ObligationCauseCode::ForLoopIterator
             | ObligationCauseCode::QuestionMark
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 2bd2b081157..19385e2d7f2 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -118,6 +118,8 @@ pub struct SelectionContext<'cx, 'tcx> {
     /// policy. In essence, canonicalized queries need their errors propagated
     /// rather than immediately reported because we do not have accurate spans.
     query_mode: TraitQueryMode,
+
+    treat_inductive_cycle: TreatInductiveCycleAs,
 }
 
 // A stack that walks back up the stack frame.
@@ -198,6 +200,27 @@ enum BuiltinImplConditions<'tcx> {
     Ambiguous,
 }
 
+#[derive(Copy, Clone)]
+pub enum TreatInductiveCycleAs {
+    /// This is the previous behavior, where `Recur` represents an inductive
+    /// cycle that is known not to hold. This is not forwards-compatible with
+    /// coinduction, and will be deprecated. This is the default behavior
+    /// of the old trait solver due to back-compat reasons.
+    Recur,
+    /// This is the behavior of the new trait solver, where inductive cycles
+    /// are treated as ambiguous and possibly holding.
+    Ambig,
+}
+
+impl From<TreatInductiveCycleAs> for EvaluationResult {
+    fn from(treat: TreatInductiveCycleAs) -> EvaluationResult {
+        match treat {
+            TreatInductiveCycleAs::Ambig => EvaluatedToUnknown,
+            TreatInductiveCycleAs::Recur => EvaluatedToRecur,
+        }
+    }
+}
+
 impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     pub fn new(infcx: &'cx InferCtxt<'tcx>) -> SelectionContext<'cx, 'tcx> {
         SelectionContext {
@@ -205,9 +228,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             freshener: infcx.freshener(),
             intercrate_ambiguity_causes: None,
             query_mode: TraitQueryMode::Standard,
+            treat_inductive_cycle: TreatInductiveCycleAs::Recur,
         }
     }
 
+    // Sets the `TreatInductiveCycleAs` mode temporarily in the selection context
+    pub fn with_treat_inductive_cycle_as<T>(
+        &mut self,
+        treat_inductive_cycle: TreatInductiveCycleAs,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T {
+        // Should be executed in a context where caching is disabled,
+        // otherwise the cache is poisoned with the temporary result.
+        assert!(self.is_intercrate());
+        let treat_inductive_cycle =
+            std::mem::replace(&mut self.treat_inductive_cycle, treat_inductive_cycle);
+        let value = f(self);
+        self.treat_inductive_cycle = treat_inductive_cycle;
+        value
+    }
+
     pub fn with_query_mode(
         infcx: &'cx InferCtxt<'tcx>,
         query_mode: TraitQueryMode,
@@ -719,7 +759,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                 stack.update_reached_depth(stack_arg.1);
                                 return Ok(EvaluatedToOk);
                             } else {
-                                return Ok(EvaluatedToRecur);
+                                return Ok(self.treat_inductive_cycle.into());
                             }
                         }
                         return Ok(EvaluatedToOk);
@@ -837,7 +877,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             }
                         }
                         ProjectAndUnifyResult::FailedNormalization => Ok(EvaluatedToAmbig),
-                        ProjectAndUnifyResult::Recursive => Ok(EvaluatedToRecur),
+                        ProjectAndUnifyResult::Recursive => Ok(self.treat_inductive_cycle.into()),
                         ProjectAndUnifyResult::MismatchedProjectionTypes(_) => Ok(EvaluatedToErr),
                     }
                 }
@@ -1151,7 +1191,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Some(EvaluatedToOk)
             } else {
                 debug!("evaluate_stack --> recursive, inductive");
-                Some(EvaluatedToRecur)
+                Some(self.treat_inductive_cycle.into())
             }
         } else {
             None
diff --git a/library/alloc/tests/str.rs b/library/alloc/tests/str.rs
index 8a4b4ac4e8d..cb59a9d4ab2 100644
--- a/library/alloc/tests/str.rs
+++ b/library/alloc/tests/str.rs
@@ -2438,10 +2438,7 @@ fn ceil_char_boundary() {
     check_many("🇯🇵", 0..=0, 0);
     check_many("🇯🇵", 1..=4, 4);
     check_many("🇯🇵", 5..=8, 8);
-}
 
-#[test]
-#[should_panic]
-fn ceil_char_boundary_above_len_panic() {
-    let _ = "x".ceil_char_boundary(2);
+    // above len
+    check_many("hello", 5..=10, 5);
 }
diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs
index faf48ae570f..3c127efb390 100644
--- a/library/core/src/cmp.rs
+++ b/library/core/src/cmp.rs
@@ -1406,6 +1406,22 @@ mod impls {
                 _ => unsafe { unreachable_unchecked() },
             }
         }
+
+        #[inline]
+        fn min(self, other: bool) -> bool {
+            self & other
+        }
+
+        #[inline]
+        fn max(self, other: bool) -> bool {
+            self | other
+        }
+
+        #[inline]
+        fn clamp(self, min: bool, max: bool) -> bool {
+            assert!(min <= max);
+            self.max(min).min(max)
+        }
     }
 
     ord_impl! { char usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
diff --git a/library/core/src/error.rs b/library/core/src/error.rs
index c32a54b77ef..1170221c10c 100644
--- a/library/core/src/error.rs
+++ b/library/core/src/error.rs
@@ -130,6 +130,7 @@ pub trait Error: Debug + Display {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     /// use core::fmt;
     /// use core::error::{request_ref, Request};
     ///
@@ -360,6 +361,7 @@ impl dyn Error {
 ///
 /// ```rust
 /// # #![feature(error_generic_member_access)]
+/// # #![feature(error_in_core)]
 /// use std::error::Error;
 /// use core::error::request_value;
 ///
@@ -383,6 +385,7 @@ where
 ///
 /// ```rust
 /// # #![feature(error_generic_member_access)]
+/// # #![feature(error_in_core)]
 /// use core::error::Error;
 /// use core::error::request_ref;
 ///
@@ -454,6 +457,7 @@ where
 ///
 /// ```
 /// #![feature(error_generic_member_access)]
+/// #![feature(error_in_core)]
 /// use core::fmt;
 /// use core::error::Request;
 /// use core::error::request_ref;
@@ -524,6 +528,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     ///
@@ -558,6 +563,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     ///
@@ -593,6 +599,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     ///
@@ -625,6 +632,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     ///
@@ -691,6 +699,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     /// use core::error::request_value;
@@ -778,6 +787,7 @@ impl<'a> Request<'a> {
     ///
     /// ```rust
     /// #![feature(error_generic_member_access)]
+    /// #![feature(error_in_core)]
     ///
     /// use core::error::Request;
     /// use core::error::request_ref;
diff --git a/library/core/src/ffi/c_str.rs b/library/core/src/ffi/c_str.rs
index b59ec12790d..4082b208c12 100644
--- a/library/core/src/ffi/c_str.rs
+++ b/library/core/src/ffi/c_str.rs
@@ -82,12 +82,12 @@ use crate::str;
 #[stable(feature = "core_c_str", since = "1.64.0")]
 #[rustc_has_incoherent_inherent_impls]
 #[lang = "CStr"]
-// FIXME:
 // `fn from` in `impl From<&CStr> for Box<CStr>` current implementation relies
 // on `CStr` being layout-compatible with `[u8]`.
-// When attribute privacy is implemented, `CStr` should be annotated as `#[repr(transparent)]`.
-// Anyway, `CStr` representation and layout are considered implementation detail, are
-// not documented and must not be relied upon.
+// However, `CStr` layout is considered an implementation detail and must not be relied upon. We
+// want `repr(transparent)` but we don't want it to show up in rustdoc, so we hide it under
+// `cfg(doc)`. This is an ad-hoc implementation of attribute privacy.
+#[cfg_attr(not(doc), repr(transparent))]
 pub struct CStr {
     // FIXME: this should not be represented with a DST slice but rather with
     //        just a raw `c_char` along with some form of marker to make
diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs
index f0fcdab00ad..7b6249207fe 100644
--- a/library/core/src/panicking.rs
+++ b/library/core/src/panicking.rs
@@ -267,16 +267,14 @@ fn assert_failed_inner(
 
     match args {
         Some(args) => panic!(
-            r#"assertion failed: `(left {} right)`
-  left: `{:?}`,
- right: `{:?}`: {}"#,
-            op, left, right, args
+            r#"assertion `left {op} right` failed: {args}
+  left: {left:?}
+ right: {right:?}"#
         ),
         None => panic!(
-            r#"assertion failed: `(left {} right)`
-  left: `{:?}`,
- right: `{:?}`"#,
-            op, left, right,
+            r#"assertion `left {op} right` failed
+  left: {left:?}
+ right: {right:?}"#
         ),
     }
 }
diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index 71c03f7bfc5..e5f34952c7d 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -267,14 +267,13 @@ impl str {
 
     /// Finds the closest `x` not below `index` where `is_char_boundary(x)` is `true`.
     ///
+    /// If `index` is greater than the length of the string, this returns the length of the string.
+    ///
     /// This method is the natural complement to [`floor_char_boundary`]. See that method
     /// for more details.
     ///
     /// [`floor_char_boundary`]: str::floor_char_boundary
     ///
-    /// # Panics
-    ///
-    /// Panics if `index > self.len()`.
     ///
     /// # Examples
     ///
@@ -292,7 +291,7 @@ impl str {
     #[inline]
     pub fn ceil_char_boundary(&self, index: usize) -> usize {
         if index > self.len() {
-            slice_error_fail(self, index, index)
+            self.len()
         } else {
             let upper_bound = Ord::min(index + 4, self.len());
             self.as_bytes()[index..upper_bound]
diff --git a/library/proc_macro/src/lib.rs b/library/proc_macro/src/lib.rs
index be89afa32b3..b641e73f4f8 100644
--- a/library/proc_macro/src/lib.rs
+++ b/library/proc_macro/src/lib.rs
@@ -24,7 +24,6 @@
 #![feature(staged_api)]
 #![feature(allow_internal_unstable)]
 #![feature(decl_macro)]
-#![feature(local_key_cell_methods)]
 #![feature(maybe_uninit_write_slice)]
 #![feature(negative_impls)]
 #![feature(new_uninit)]
diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index 67e58fd1b86..43cecb19b14 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -110,12 +110,12 @@ impl crate::sealed::Sealed for OsString {}
 /// [conversions]: super#conversions
 #[cfg_attr(not(test), rustc_diagnostic_item = "OsStr")]
 #[stable(feature = "rust1", since = "1.0.0")]
-// FIXME:
 // `OsStr::from_inner` current implementation relies
 // on `OsStr` being layout-compatible with `Slice`.
-// When attribute privacy is implemented, `OsStr` should be annotated as `#[repr(transparent)]`.
-// Anyway, `OsStr` representation and layout are considered implementation details, are
-// not documented and must not be relied upon.
+// However, `OsStr` layout is considered an implementation detail and must not be relied upon. We
+// want `repr(transparent)` but we don't want it to show up in rustdoc, so we hide it under
+// `cfg(doc)`. This is an ad-hoc implementation of attribute privacy.
+#[cfg_attr(not(doc), repr(transparent))]
 pub struct OsStr {
     inner: Slice,
 }
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 99f7a60f8ab..5842c096f1a 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -1158,12 +1158,12 @@ impl FusedIterator for Ancestors<'_> {}
 /// Which method works best depends on what kind of situation you're in.
 #[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")]
 #[stable(feature = "rust1", since = "1.0.0")]
-// FIXME:
 // `PathBuf::as_mut_vec` current implementation relies
 // on `PathBuf` being layout-compatible with `Vec<u8>`.
-// When attribute privacy is implemented, `PathBuf` should be annotated as `#[repr(transparent)]`.
-// Anyway, `PathBuf` representation and layout are considered implementation detail, are
-// not documented and must not be relied upon.
+// However, `PathBuf` layout is considered an implementation detail and must not be relied upon. We
+// want `repr(transparent)` but we don't want it to show up in rustdoc, so we hide it under
+// `cfg(doc)`. This is an ad-hoc implementation of attribute privacy.
+#[cfg_attr(not(doc), repr(transparent))]
 pub struct PathBuf {
     inner: OsString,
 }
@@ -1983,12 +1983,12 @@ impl AsRef<OsStr> for PathBuf {
 /// ```
 #[cfg_attr(not(test), rustc_diagnostic_item = "Path")]
 #[stable(feature = "rust1", since = "1.0.0")]
-// FIXME:
 // `Path::new` current implementation relies
 // on `Path` being layout-compatible with `OsStr`.
-// When attribute privacy is implemented, `Path` should be annotated as `#[repr(transparent)]`.
-// Anyway, `Path` representation and layout are considered implementation detail, are
-// not documented and must not be relied upon.
+// However, `Path` layout is considered an implementation detail and must not be relied upon. We
+// want `repr(transparent)` but we don't want it to show up in rustdoc, so we hide it under
+// `cfg(doc)`. This is an ad-hoc implementation of attribute privacy.
+#[cfg_attr(not(doc), repr(transparent))]
 pub struct Path {
     inner: OsStr,
 }
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index f25ad2ece71..f54d5934175 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -1530,10 +1530,19 @@ impl From<fs::File> for Stdio {
 // vs `_exit`.  Naming of Unix system calls is not standardised across Unices, so terminology is a
 // matter of convention and tradition.  For clarity we usually speak of `exit`, even when we might
 // mean an underlying system call such as `_exit`.
-#[derive(PartialEq, Eq, Clone, Copy, Debug, Default)]
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
 #[stable(feature = "process", since = "1.0.0")]
 pub struct ExitStatus(imp::ExitStatus);
 
+/// The default value is one which indicates successful completion.
+#[stable(feature = "process-exitcode-default", since = "CURRENT_RUSTC_VERSION")]
+impl Default for ExitStatus {
+    fn default() -> Self {
+        // Ideally this would be done by ExitCode::default().into() but that is complicated.
+        ExitStatus::from_inner(imp::ExitStatus::default())
+    }
+}
+
 /// Allows extension traits within `std`.
 #[unstable(feature = "sealed", issue = "none")]
 impl crate::sealed::Sealed for ExitStatus {}
diff --git a/library/std/src/sys/wasi/fd.rs b/library/std/src/sys/wasi/fd.rs
index 1b50c2ea6dd..d7295a799da 100644
--- a/library/std/src/sys/wasi/fd.rs
+++ b/library/std/src/sys/wasi/fd.rs
@@ -16,14 +16,20 @@ pub struct WasiFd {
 fn iovec<'a>(a: &'a mut [IoSliceMut<'_>]) -> &'a [wasi::Iovec] {
     assert_eq!(mem::size_of::<IoSliceMut<'_>>(), mem::size_of::<wasi::Iovec>());
     assert_eq!(mem::align_of::<IoSliceMut<'_>>(), mem::align_of::<wasi::Iovec>());
-    // SAFETY: `IoSliceMut` and `IoVec` have exactly the same memory layout
+    // SAFETY: `IoSliceMut` and `IoVec` have exactly the same memory layout.
+    // We decorate our `IoSliceMut` with `repr(transparent)` (see `io.rs`), and
+    // `crate::io::IoSliceMut` is a `repr(transparent)` wrapper around our type, so this is
+    // guaranteed.
     unsafe { mem::transmute(a) }
 }
 
 fn ciovec<'a>(a: &'a [IoSlice<'_>]) -> &'a [wasi::Ciovec] {
     assert_eq!(mem::size_of::<IoSlice<'_>>(), mem::size_of::<wasi::Ciovec>());
     assert_eq!(mem::align_of::<IoSlice<'_>>(), mem::align_of::<wasi::Ciovec>());
-    // SAFETY: `IoSlice` and `CIoVec` have exactly the same memory layout
+    // SAFETY: `IoSlice` and `CIoVec` have exactly the same memory layout.
+    // We decorate our `IoSlice` with `repr(transparent)` (see `io.rs`), and
+    // `crate::io::IoSlice` is a `repr(transparent)` wrapper around our type, so this is
+    // guaranteed.
     unsafe { mem::transmute(a) }
 }
 
diff --git a/library/std/src/sys/wasi/thread.rs b/library/std/src/sys/wasi/thread.rs
index d27b7a2e0f5..dbad425976a 100644
--- a/library/std/src/sys/wasi/thread.rs
+++ b/library/std/src/sys/wasi/thread.rs
@@ -20,9 +20,9 @@ cfg_if::cfg_if! {
             // https://github.com/WebAssembly/wasi-libc/blob/a6f871343313220b76009827ed0153586361c0d5/libc-top-half/musl/include/alltypes.h.in#L108
             #[repr(C)]
             union pthread_attr_union {
-                __i: [ffi::c_int; if mem::size_of::<ffi::c_int>() == 8 { 14 } else { 9 }],
-                __vi: [ffi::c_int; if mem::size_of::<ffi::c_int>() == 8 { 14 } else { 9 }],
-                __s: [ffi::c_ulong; if mem::size_of::<ffi::c_int>() == 8 { 7 } else { 9 }],
+                __i: [ffi::c_int; if mem::size_of::<ffi::c_long>() == 8 { 14 } else { 9 }],
+                __vi: [ffi::c_int; if mem::size_of::<ffi::c_long>() == 8 { 14 } else { 9 }],
+                __s: [ffi::c_ulong; if mem::size_of::<ffi::c_long>() == 8 { 7 } else { 9 }],
             }
 
             #[repr(C)]
diff --git a/library/std/src/sys_common/wtf8.rs b/library/std/src/sys_common/wtf8.rs
index 195d175cc9b..67db5ebd89c 100644
--- a/library/std/src/sys_common/wtf8.rs
+++ b/library/std/src/sys_common/wtf8.rs
@@ -459,6 +459,7 @@ impl Wtf8Buf {
     /// Converts this `Wtf8Buf` into a boxed `Wtf8`.
     #[inline]
     pub fn into_box(self) -> Box<Wtf8> {
+        // SAFETY: relies on `Wtf8` being `repr(transparent)`.
         unsafe { mem::transmute(self.bytes.into_boxed_slice()) }
     }
 
@@ -511,6 +512,7 @@ impl Extend<CodePoint> for Wtf8Buf {
 /// Similar to `&str`, but can additionally contain surrogate code points
 /// if they’re not in a surrogate pair.
 #[derive(Eq, Ord, PartialEq, PartialOrd)]
+#[repr(transparent)]
 pub struct Wtf8 {
     bytes: [u8],
 }
diff --git a/library/std/src/thread/local.rs b/library/std/src/thread/local.rs
index 1b86d898cc7..21515adc6c4 100644
--- a/library/std/src/thread/local.rs
+++ b/library/std/src/thread/local.rs
@@ -313,7 +313,6 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::Cell;
     ///
     /// thread_local! {
@@ -326,7 +325,7 @@ impl<T: 'static> LocalKey<Cell<T>> {
     ///
     /// assert_eq!(X.get(), 123);
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn set(&'static self, value: T) {
         self.initialize_with(Cell::new(value), |value, cell| {
             if let Some(value) = value {
@@ -351,7 +350,6 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::Cell;
     ///
     /// thread_local! {
@@ -360,7 +358,7 @@ impl<T: 'static> LocalKey<Cell<T>> {
     ///
     /// assert_eq!(X.get(), 1);
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn get(&'static self) -> T
     where
         T: Copy,
@@ -381,7 +379,6 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::Cell;
     ///
     /// thread_local! {
@@ -391,7 +388,7 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// assert_eq!(X.take(), Some(1));
     /// assert_eq!(X.take(), None);
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn take(&'static self) -> T
     where
         T: Default,
@@ -412,7 +409,6 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::Cell;
     ///
     /// thread_local! {
@@ -422,7 +418,7 @@ impl<T: 'static> LocalKey<Cell<T>> {
     /// assert_eq!(X.replace(2), 1);
     /// assert_eq!(X.replace(3), 2);
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn replace(&'static self, value: T) -> T {
         self.with(|cell| cell.replace(value))
     }
@@ -444,7 +440,6 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     /// # Example
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::RefCell;
     ///
     /// thread_local! {
@@ -453,7 +448,7 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     ///
     /// X.with_borrow(|v| assert!(v.is_empty()));
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn with_borrow<F, R>(&'static self, f: F) -> R
     where
         F: FnOnce(&T) -> R,
@@ -476,7 +471,6 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     /// # Example
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::RefCell;
     ///
     /// thread_local! {
@@ -487,7 +481,7 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     ///
     /// X.with_borrow(|v| assert_eq!(*v, vec![1]));
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn with_borrow_mut<F, R>(&'static self, f: F) -> R
     where
         F: FnOnce(&mut T) -> R,
@@ -511,7 +505,6 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::RefCell;
     ///
     /// thread_local! {
@@ -524,7 +517,7 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     ///
     /// X.with_borrow(|v| assert_eq!(*v, vec![1, 2, 3]));
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn set(&'static self, value: T) {
         self.initialize_with(RefCell::new(value), |value, cell| {
             if let Some(value) = value {
@@ -551,7 +544,6 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::RefCell;
     ///
     /// thread_local! {
@@ -566,7 +558,7 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     ///
     /// X.with_borrow(|v| assert!(v.is_empty()));
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn take(&'static self) -> T
     where
         T: Default,
@@ -586,7 +578,6 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(local_key_cell_methods)]
     /// use std::cell::RefCell;
     ///
     /// thread_local! {
@@ -598,7 +589,7 @@ impl<T: 'static> LocalKey<RefCell<T>> {
     ///
     /// X.with_borrow(|v| assert_eq!(*v, vec![1, 2, 3]));
     /// ```
-    #[unstable(feature = "local_key_cell_methods", issue = "92122")]
+    #[stable(feature = "local_key_cell_methods", since = "CURRENT_RUSTC_VERSION")]
     pub fn replace(&'static self, value: T) -> T {
         self.with(|cell| cell.replace(value))
     }
diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md
index 4622148e869..f882a31de5a 100644
--- a/src/doc/rustc/src/codegen-options/index.md
+++ b/src/doc/rustc/src/codegen-options/index.md
@@ -584,7 +584,7 @@ See the [Symbol Mangling] chapter for details on symbol mangling and the manglin
 This instructs `rustc` to generate code specifically for a particular processor.
 
 You can run `rustc --print target-cpus` to see the valid options to pass
-and the default target CPU for the current buid target.
+and the default target CPU for the current build target.
 Each target has a default base CPU. Special values include:
 
 * `native` can be passed to use the processor of the host machine.
diff --git a/src/doc/rustc/src/platform-support/aarch64-unknown-teeos.md b/src/doc/rustc/src/platform-support/aarch64-unknown-teeos.md
index 8fc5e6dd92b..8bc9381342d 100644
--- a/src/doc/rustc/src/platform-support/aarch64-unknown-teeos.md
+++ b/src/doc/rustc/src/platform-support/aarch64-unknown-teeos.md
@@ -10,7 +10,7 @@ It's very small that there is no RwLock, no network, no stdin, and no file syste
 Some abbreviation:
 | Abbreviation | The full text | Description |
 |  ----  | ----  | ---- |
-| TEE | Trusted Execution Environment | ARM TrustZone devide the system into two worlds/modes -- the secure world/mode and the normal world/mode. TEE is in the secure world/mode. |
+| TEE | Trusted Execution Environment | ARM TrustZone divides the system into two worlds/modes -- the secure world/mode and the normal world/mode. TEE is in the secure world/mode. |
 | REE | Rich Execution Environment | The normal world. for example, Linux for Android phone is in REE side. |
 | TA | Trusted Application | The app run in TEE side system. |
 | CA | Client Application | The progress run in REE side system. |
diff --git a/src/doc/rustc/src/platform-support/loongarch-linux.md b/src/doc/rustc/src/platform-support/loongarch-linux.md
index 17e85590f2c..e8f55b8bfce 100644
--- a/src/doc/rustc/src/platform-support/loongarch-linux.md
+++ b/src/doc/rustc/src/platform-support/loongarch-linux.md
@@ -71,7 +71,7 @@ CXX_loongarch64_unknown_linux_gnu=/TOOLCHAIN_PATH/bin/loongarch64-unknown-linux-
 AR_loongarch64_unknown_linux_gnu=/TOOLCHAIN_PATH/bin/loongarch64-unknown-linux-gnu-gcc-ar \
 CARGO_TARGET_LOONGARCH64_UNKNOWN_LINUX_GNUN_LINKER=/TOOLCHAIN_PATH/bin/loongarch64-unknown-linux-gnu-gcc \
 # SET TARGET SYSTEM LIBRARY PATH
-CARGO_TARGET_LOONGARCH64_UNKNOWN_LINUX_GNUN_RUNNER="qemu-loongarch64 -L /TOOLCHAIN_PATH/TARGET_LIBRAY_PATH" \
+CARGO_TARGET_LOONGARCH64_UNKNOWN_LINUX_GNUN_RUNNER="qemu-loongarch64 -L /TOOLCHAIN_PATH/TARGET_LIBRARY_PATH" \
 cargo run --target loongarch64-unknown-linux-gnu --release
 ```
 Tested on x86 architecture, other architectures not tested.
diff --git a/src/doc/rustc/src/platform-support/netbsd.md b/src/doc/rustc/src/platform-support/netbsd.md
index 23f4488de6e..3891d6d3148 100644
--- a/src/doc/rustc/src/platform-support/netbsd.md
+++ b/src/doc/rustc/src/platform-support/netbsd.md
@@ -86,7 +86,7 @@ The Rust testsuite could presumably be run natively.
 
 For the systems where the maintainer can build natively, the rust
 compiler itself is re-built natively.  This involves the rust compiler
-being re-built with the newly self-built rust compiler, so excercises
+being re-built with the newly self-built rust compiler, so exercises
 the result quite extensively.
 
 Additionally, for some systems we build `librsvg`, and for the more
diff --git a/src/doc/rustc/src/platform-support/x86_64h-apple-darwin.md b/src/doc/rustc/src/platform-support/x86_64h-apple-darwin.md
index 1a6f7bb834c..0fe9d4edaca 100644
--- a/src/doc/rustc/src/platform-support/x86_64h-apple-darwin.md
+++ b/src/doc/rustc/src/platform-support/x86_64h-apple-darwin.md
@@ -20,7 +20,7 @@ will fail to load on machines that do not support this.
 
 It should support the full standard library (`std` and `alloc` either with
 default or user-defined allocators). This target is probably most useful when
-targetted via cross-compilation (including from `x86_64-apple-darwin`), but if
+targeted via cross-compilation (including from `x86_64-apple-darwin`), but if
 built manually, the host tools work.
 
 It is similar to `x86_64-apple-darwin` in nearly all respects, although the
@@ -49,7 +49,7 @@ suite seems to work.
 
 Cross-compilation to this target from Apple hosts should generally work without
 much configuration, so long as XCode and the CommandLineTools are installed.
-Targetting it from non-Apple hosts is difficult, but no moreso than targetting
+Targeting it from non-Apple hosts is difficult, but no more so than targeting
 `x86_64-apple-darwin`.
 
 When compiling C code for this target, either the "`x86_64h-apple-macosx*`" LLVM
diff --git a/src/doc/unstable-book/src/compiler-flags/path-options.md b/src/doc/unstable-book/src/compiler-flags/path-options.md
index 0f2437020dd..0786ef1f166 100644
--- a/src/doc/unstable-book/src/compiler-flags/path-options.md
+++ b/src/doc/unstable-book/src/compiler-flags/path-options.md
@@ -1,6 +1,6 @@
 # `--print` Options
 
-The behavior of the `--print` flag can be modified by optionally be specifiying a filepath
+The behavior of the `--print` flag can be modified by optionally be specifying a filepath
 for each requested information kind, in the format `--print KIND=PATH`, just like for
 `--emit`. When a path is specified, information will be written there instead of to stdout.
 
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 389bac0f09d..2456e8818eb 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -9,7 +9,7 @@ use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, DefIdSet, LocalDefId};
+use rustc_hir::def_id::{DefId, DefIdSet, LocalModDefId};
 use rustc_hir::Mutability;
 use rustc_metadata::creader::{CStore, LoadedMacro};
 use rustc_middle::ty::fast_reject::SimplifiedType;
@@ -138,7 +138,7 @@ pub(crate) fn try_inline(
 pub(crate) fn try_inline_glob(
     cx: &mut DocContext<'_>,
     res: Res,
-    current_mod: LocalDefId,
+    current_mod: LocalModDefId,
     visited: &mut DefIdSet,
     inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
     import: &hir::Item<'_>,
@@ -154,7 +154,7 @@ pub(crate) fn try_inline_glob(
             // reexported by the glob, e.g. because they are shadowed by something else.
             let reexports = cx
                 .tcx
-                .module_children_local(current_mod)
+                .module_children_local(current_mod.to_local_def_id())
                 .iter()
                 .filter(|child| !child.reexport_chain.is_empty())
                 .filter_map(|child| child.res.opt_def_id())
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index b6ba4c853d4..624f1620f2c 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1551,7 +1551,7 @@ fn first_non_private<'tcx>(
         }
         [parent, leaf] if parent.ident.name == kw::Super => {
             let parent_mod = cx.tcx.parent_module(hir_id);
-            if let Some(super_parent) = cx.tcx.opt_local_parent(parent_mod) {
+            if let Some(super_parent) = cx.tcx.opt_local_parent(parent_mod.to_local_def_id()) {
                 (super_parent, leaf.ident)
             } else {
                 // If we can't find the parent of the parent, then the parent is already the crate.
@@ -2828,7 +2828,7 @@ fn clean_use_statement_inner<'tcx>(
     // The parent of the module in which this import resides. This
     // is the same as `current_mod` if that's already the top
     // level module.
-    let parent_mod = cx.tcx.parent_module_from_def_id(current_mod);
+    let parent_mod = cx.tcx.parent_module_from_def_id(current_mod.to_local_def_id());
 
     // This checks if the import can be seen from a higher level module.
     // In other words, it checks if the visibility is the equivalent of
diff --git a/src/tools/clippy/clippy_lints/src/dereference.rs b/src/tools/clippy/clippy_lints/src/dereference.rs
index bc011a6c354..58c27855000 100644
--- a/src/tools/clippy/clippy_lints/src/dereference.rs
+++ b/src/tools/clippy/clippy_lints/src/dereference.rs
@@ -802,7 +802,8 @@ fn in_postfix_position<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> boo
         match parent.kind {
             ExprKind::Call(child, _) | ExprKind::MethodCall(_, child, _, _) | ExprKind::Index(child, _, _)
                 if child.hir_id == e.hir_id => true,
-            ExprKind::Field(_, _) | ExprKind::Match(_, _, MatchSource::TryDesugar | MatchSource::AwaitDesugar) => true,
+            ExprKind::Match(.., MatchSource::TryDesugar(_) | MatchSource::AwaitDesugar)
+                | ExprKind::Field(_, _) => true,
             _ => false,
         }
     } else {
diff --git a/src/tools/clippy/clippy_lints/src/matches/mod.rs b/src/tools/clippy/clippy_lints/src/matches/mod.rs
index 6d16d188754..930386a60aa 100644
--- a/src/tools/clippy/clippy_lints/src/matches/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/matches/mod.rs
@@ -1038,7 +1038,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches {
                 wild_in_or_pats::check(cx, arms);
             }
 
-            if source == MatchSource::TryDesugar {
+            if let MatchSource::TryDesugar(_) = source {
                 try_err::check(cx, expr, ex);
             }
 
diff --git a/src/tools/clippy/clippy_lints/src/matches/try_err.rs b/src/tools/clippy/clippy_lints/src/matches/try_err.rs
index 99a748489b4..0fd6f533db0 100644
--- a/src/tools/clippy/clippy_lints/src/matches/try_err.rs
+++ b/src/tools/clippy/clippy_lints/src/matches/try_err.rs
@@ -80,7 +80,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutine
 
 /// Finds function return type by examining return expressions in match arms.
 fn find_return_type<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx ExprKind<'_>) -> Option<Ty<'tcx>> {
-    if let ExprKind::Match(_, arms, MatchSource::TryDesugar) = expr {
+    if let ExprKind::Match(_, arms, MatchSource::TryDesugar(_)) = expr {
         for arm in *arms {
             if let ExprKind::Ret(Some(ret)) = arm.body.kind {
                 return Some(cx.typeck_results().expr_ty(ret));
diff --git a/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs b/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs
index 7eb325ee7b5..eb4f003d38a 100644
--- a/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs
@@ -64,7 +64,7 @@ pub(super) fn check(
                     ExprKind::Path(QPath::LangItem(rustc_hir::LangItem::TryTraitBranch, _, _))
                 ),
                 ExprKind::MethodCall(_, self_arg, ..) if expr.hir_id == self_arg.hir_id => true,
-                ExprKind::Match(_, _, MatchSource::TryDesugar | MatchSource::AwaitDesugar)
+                ExprKind::Match(_, _, MatchSource::TryDesugar(_) | MatchSource::AwaitDesugar)
                 | ExprKind::Field(..)
                 | ExprKind::Index(..) => true,
                 _ => false,
diff --git a/src/tools/clippy/clippy_lints/src/methods/str_splitn.rs b/src/tools/clippy/clippy_lints/src/methods/str_splitn.rs
index 41986551da4..7016ad0a80f 100644
--- a/src/tools/clippy/clippy_lints/src/methods/str_splitn.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/str_splitn.rs
@@ -236,7 +236,7 @@ fn indirect_usage<'tcx>(
             !matches!(
                 node,
                 Node::Expr(Expr {
-                    kind: ExprKind::Match(.., MatchSource::TryDesugar),
+                    kind: ExprKind::Match(.., MatchSource::TryDesugar(_)),
                     ..
                 })
             )
diff --git a/src/tools/clippy/clippy_lints/src/needless_question_mark.rs b/src/tools/clippy/clippy_lints/src/needless_question_mark.rs
index e2a7ba02a04..7b0f7eaf1f0 100644
--- a/src/tools/clippy/clippy_lints/src/needless_question_mark.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_question_mark.rs
@@ -122,7 +122,7 @@ fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
         } else {
             return;
         };
-        if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar) = &arg.kind;
+        if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar(_)) = &arg.kind;
         if let ExprKind::Call(called, [inner_expr]) = &inner_expr_with_q.kind;
         if let ExprKind::Path(QPath::LangItem(LangItem::TryTraitBranch, ..)) = &called.kind;
         if expr.span.ctxt() == inner_expr.span.ctxt();
diff --git a/src/tools/clippy/clippy_lints/src/question_mark_used.rs b/src/tools/clippy/clippy_lints/src/question_mark_used.rs
index ff66b8a0095..d0de33e3c4f 100644
--- a/src/tools/clippy/clippy_lints/src/question_mark_used.rs
+++ b/src/tools/clippy/clippy_lints/src/question_mark_used.rs
@@ -34,7 +34,7 @@ declare_lint_pass!(QuestionMarkUsed => [QUESTION_MARK_USED]);
 
 impl<'tcx> LateLintPass<'tcx> for QuestionMarkUsed {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let ExprKind::Match(_, _, MatchSource::TryDesugar) = expr.kind {
+        if let ExprKind::Match(_, _, MatchSource::TryDesugar(_)) = expr.kind {
             if !span_is_local(expr.span) {
                 return;
             }
diff --git a/src/tools/clippy/clippy_lints/src/redundant_closure_call.rs b/src/tools/clippy/clippy_lints/src/redundant_closure_call.rs
index 4e3efe97b8c..fc49b58e0a7 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_closure_call.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_closure_call.rs
@@ -52,7 +52,7 @@ impl ReturnVisitor {
 
 impl<'tcx> Visitor<'tcx> for ReturnVisitor {
     fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
-        if let hir::ExprKind::Ret(_) | hir::ExprKind::Match(.., hir::MatchSource::TryDesugar) = ex.kind {
+        if let hir::ExprKind::Ret(_) | hir::ExprKind::Match(.., hir::MatchSource::TryDesugar(_)) = ex.kind {
             self.found_return = true;
         } else {
             hir_visit::walk_expr(self, ex);
diff --git a/src/tools/clippy/clippy_lints/src/returns.rs b/src/tools/clippy/clippy_lints/src/returns.rs
index 351bacf5691..d6b9a49d2fe 100644
--- a/src/tools/clippy/clippy_lints/src/returns.rs
+++ b/src/tools/clippy/clippy_lints/src/returns.rs
@@ -164,7 +164,7 @@ impl<'tcx> LateLintPass<'tcx> for Return {
         if !in_external_macro(cx.sess(), stmt.span)
             && let StmtKind::Semi(expr) = stmt.kind
             && let ExprKind::Ret(Some(ret)) = expr.kind
-            && let ExprKind::Match(.., MatchSource::TryDesugar) = ret.kind
+            && let ExprKind::Match(.., MatchSource::TryDesugar(_)) = ret.kind
             // Ensure this is not the final stmt, otherwise removing it would cause a compile error
             && let OwnerNode::Item(item) = cx.tcx.hir().owner(cx.tcx.hir().get_parent_item(expr.hir_id))
             && let ItemKind::Fn(_, _, body) = item.kind
diff --git a/src/tools/clippy/clippy_lints/src/unit_types/unit_arg.rs b/src/tools/clippy/clippy_lints/src/unit_types/unit_arg.rs
index dd120599c04..462b1aa8153 100644
--- a/src/tools/clippy/clippy_lints/src/unit_types/unit_arg.rs
+++ b/src/tools/clippy/clippy_lints/src/unit_types/unit_arg.rs
@@ -42,7 +42,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
             if cx.typeck_results().expr_ty(arg).is_unit() && !utils::is_unit_literal(arg) {
                 !matches!(
                     &arg.kind,
-                    ExprKind::Match(.., MatchSource::TryDesugar) | ExprKind::Path(..)
+                    ExprKind::Match(.., MatchSource::TryDesugar(_)) | ExprKind::Path(..)
                 )
             } else {
                 false
diff --git a/src/tools/clippy/clippy_lints/src/useless_conversion.rs b/src/tools/clippy/clippy_lints/src/useless_conversion.rs
index 92b694d3076..bd4dc07a42b 100644
--- a/src/tools/clippy/clippy_lints/src/useless_conversion.rs
+++ b/src/tools/clippy/clippy_lints/src/useless_conversion.rs
@@ -113,7 +113,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
         }
 
         match e.kind {
-            ExprKind::Match(_, arms, MatchSource::TryDesugar) => {
+            ExprKind::Match(_, arms, MatchSource::TryDesugar(_)) => {
                 let (ExprKind::Ret(Some(e)) | ExprKind::Break(_, Some(e))) = arms[0].body.kind else {
                     return;
                 };
diff --git a/src/tools/clippy/clippy_utils/src/check_proc_macro.rs b/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
index 60fab1ec41a..6be8b8bb916 100644
--- a/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
+++ b/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
@@ -149,7 +149,7 @@ fn expr_search_pat(tcx: TyCtxt<'_>, e: &Expr<'_>) -> (Pat, Pat) {
             (Pat::Str("for"), Pat::Str("}"))
         },
         ExprKind::Match(_, _, MatchSource::Normal) => (Pat::Str("match"), Pat::Str("}")),
-        ExprKind::Match(e, _, MatchSource::TryDesugar) => (expr_search_pat(tcx, e).0, Pat::Str("?")),
+        ExprKind::Match(e, _, MatchSource::TryDesugar(_)) => (expr_search_pat(tcx, e).0, Pat::Str("?")),
         ExprKind::Match(e, _, MatchSource::AwaitDesugar) | ExprKind::Yield(e, YieldSource::Await { .. }) => {
             (expr_search_pat(tcx, e).0, Pat::Str("await"))
         },
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 171b7faf219..6c4cec59524 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -83,7 +83,7 @@ use rustc_ast::Attribute;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::unhash::UnhashMap;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
+use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalModDefId, LOCAL_CRATE};
 use rustc_hir::hir_id::{HirIdMap, HirIdSet};
 use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
 use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr, ResultOk};
@@ -1765,7 +1765,7 @@ pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tc
 
     if let ExprKind::Match(_, arms, ref source) = expr.kind {
         // desugared from a `?` operator
-        if *source == MatchSource::TryDesugar {
+        if let MatchSource::TryDesugar(_) = *source {
             return Some(expr);
         }
 
@@ -2370,11 +2370,11 @@ pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool {
     false
 }
 
-static TEST_ITEM_NAMES_CACHE: OnceLock<Mutex<FxHashMap<LocalDefId, Vec<Symbol>>>> = OnceLock::new();
+static TEST_ITEM_NAMES_CACHE: OnceLock<Mutex<FxHashMap<LocalModDefId, Vec<Symbol>>>> = OnceLock::new();
 
-fn with_test_item_names(tcx: TyCtxt<'_>, module: LocalDefId, f: impl Fn(&[Symbol]) -> bool) -> bool {
+fn with_test_item_names(tcx: TyCtxt<'_>, module: LocalModDefId, f: impl Fn(&[Symbol]) -> bool) -> bool {
     let cache = TEST_ITEM_NAMES_CACHE.get_or_init(|| Mutex::new(FxHashMap::default()));
-    let mut map: MutexGuard<'_, FxHashMap<LocalDefId, Vec<Symbol>>> = cache.lock().unwrap();
+    let mut map: MutexGuard<'_, FxHashMap<LocalModDefId, Vec<Symbol>>> = cache.lock().unwrap();
     let value = map.entry(module);
     match value {
         Entry::Occupied(entry) => f(entry.get()),
diff --git a/src/tools/clippy/clippy_utils/src/visitors.rs b/src/tools/clippy/clippy_utils/src/visitors.rs
index f83988a6e32..3b47a451345 100644
--- a/src/tools/clippy/clippy_utils/src/visitors.rs
+++ b/src/tools/clippy/clippy_utils/src/visitors.rs
@@ -161,7 +161,7 @@ pub fn for_each_expr_with_closures<'tcx, B, C: Continue>(
 /// returns `true` if expr contains match expr desugared from try
 fn contains_try(expr: &hir::Expr<'_>) -> bool {
     for_each_expr(expr, |e| {
-        if matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar)) {
+        if matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar(_))) {
             ControlFlow::Break(())
         } else {
             ControlFlow::Continue(())
diff --git a/src/tools/clippy/tests/ui/if_same_then_else2.rs b/src/tools/clippy/tests/ui/if_same_then_else2.rs
index 0b171f21d0c..c545434efe5 100644
--- a/src/tools/clippy/tests/ui/if_same_then_else2.rs
+++ b/src/tools/clippy/tests/ui/if_same_then_else2.rs
@@ -98,7 +98,7 @@ fn if_same_then_else2() -> Result<&'static str, ()> {
     };
 
     if true {
-        //~^ ERROR: this `if` has identical blocks
+        // FIXME: should emit "this `if` has identical blocks"
         Ok("foo")?;
     } else {
         Ok("foo")?;
diff --git a/src/tools/clippy/tests/ui/if_same_then_else2.stderr b/src/tools/clippy/tests/ui/if_same_then_else2.stderr
index 56e5f3e45b2..37fe787d1de 100644
--- a/src/tools/clippy/tests/ui/if_same_then_else2.stderr
+++ b/src/tools/clippy/tests/ui/if_same_then_else2.stderr
@@ -83,25 +83,6 @@ LL | |     };
    | |_____^
 
 error: this `if` has identical blocks
-  --> $DIR/if_same_then_else2.rs:100:13
-   |
-LL |       if true {
-   |  _____________^
-LL | |
-LL | |         Ok("foo")?;
-LL | |     } else {
-   | |_____^
-   |
-note: same as this
-  --> $DIR/if_same_then_else2.rs:103:12
-   |
-LL |       } else {
-   |  ____________^
-LL | |         Ok("foo")?;
-LL | |     }
-   | |_____^
-
-error: this `if` has identical blocks
   --> $DIR/if_same_then_else2.rs:124:20
    |
 LL |       } else if true {
@@ -122,5 +103,5 @@ LL | |         return Ok(&foo[0..]);
 LL | |     }
    | |_____^
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 
diff --git a/src/tools/miri/src/lib.rs b/src/tools/miri/src/lib.rs
index 0e50618ad9e..d57da574315 100644
--- a/src/tools/miri/src/lib.rs
+++ b/src/tools/miri/src/lib.rs
@@ -7,7 +7,6 @@
 #![feature(variant_count)]
 #![feature(yeet_expr)]
 #![feature(nonzero_ops)]
-#![feature(local_key_cell_methods)]
 #![feature(round_ties_even)]
 #![feature(os_str_bytes)]
 #![feature(lint_reasons)]
diff --git a/tests/rustdoc-gui/unsafe-fn.goml b/tests/rustdoc-gui/unsafe-fn.goml
index 51007b653d9..8d26f15f37f 100644
--- a/tests/rustdoc-gui/unsafe-fn.goml
+++ b/tests/rustdoc-gui/unsafe-fn.goml
@@ -23,6 +23,6 @@ define-function: (
     },
 )
 
-call-function: ("sup-check", ("dark", "rgb(221, 221, 221)"))
-call-function: ("sup-check", ("ayu", "rgb(197, 197, 197)"))
-call-function: ("sup-check", ("light", "rgb(0, 0, 0)"))
+call-function: ("sup-check", ("ayu", "#c5c5c5"))
+call-function: ("sup-check", ("dark", "#ddd"))
+call-function: ("sup-check", ("light", "black"))
diff --git a/tests/ui/associated-type-bounds/consts.rs b/tests/ui/associated-type-bounds/consts.rs
new file mode 100644
index 00000000000..9b95b1b52c0
--- /dev/null
+++ b/tests/ui/associated-type-bounds/consts.rs
@@ -0,0 +1,10 @@
+#![feature(associated_type_bounds)]
+
+pub fn accept(_: impl Trait<K: Copy>) {}
+//~^ ERROR expected associated type, found associated constant
+
+pub trait Trait {
+    const K: i32;
+}
+
+fn main() {}
diff --git a/tests/ui/associated-type-bounds/consts.stderr b/tests/ui/associated-type-bounds/consts.stderr
new file mode 100644
index 00000000000..ddfb6612b08
--- /dev/null
+++ b/tests/ui/associated-type-bounds/consts.stderr
@@ -0,0 +1,10 @@
+error: expected associated type, found associated constant
+  --> $DIR/consts.rs:3:29
+   |
+LL | pub fn accept(_: impl Trait<K: Copy>) {}
+   |                             ^
+   |
+   = note: trait bounds not allowed on associated constant
+
+error: aborting due to previous error
+
diff --git a/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.rs b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.rs
new file mode 100644
index 00000000000..01f7d6ce901
--- /dev/null
+++ b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.rs
@@ -0,0 +1,35 @@
+#![deny(coinductive_overlap_in_coherence)]
+
+use std::borrow::Borrow;
+use std::cmp::Ordering;
+use std::marker::PhantomData;
+
+#[derive(PartialEq, Default)]
+pub(crate) struct Interval<T>(PhantomData<T>);
+
+// This impl overlaps with the `derive` unless we reject the nested
+// `Interval<?1>: PartialOrd<Interval<?1>>` candidate which results
+// in a - currently inductive - cycle.
+impl<T, Q> PartialEq<Q> for Interval<T>
+//~^ ERROR implementations of `PartialEq<Interval<_>>` for `Interval<_>` will conflict in the future
+//~| WARN this was previously accepted by the compiler but is being phased out
+where
+    T: Borrow<Q>,
+    Q: ?Sized + PartialOrd,
+{
+    fn eq(&self, _: &Q) -> bool {
+        true
+    }
+}
+
+impl<T, Q> PartialOrd<Q> for Interval<T>
+where
+    T: Borrow<Q>,
+    Q: ?Sized + PartialOrd,
+{
+    fn partial_cmp(&self, _: &Q) -> Option<Ordering> {
+        None
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr
new file mode 100644
index 00000000000..f315ba82130
--- /dev/null
+++ b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr
@@ -0,0 +1,23 @@
+error: implementations of `PartialEq<Interval<_>>` for `Interval<_>` will conflict in the future
+  --> $DIR/warn-when-cycle-is-error-in-coherence.rs:13:1
+   |
+LL | #[derive(PartialEq, Default)]
+   |          --------- the second impl is here
+...
+LL | impl<T, Q> PartialEq<Q> for Interval<T>
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the first impl is here
+...
+LL |     Q: ?Sized + PartialOrd,
+   |                 ---------- `Interval<_>: PartialOrd` may be considered to hold in future releases, causing the impls to overlap
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #114040 <https://github.com/rust-lang/rust/issues/114040>
+   = note: impls that are not considered to overlap may be considered to overlap in the future
+note: the lint level is defined here
+  --> $DIR/warn-when-cycle-is-error-in-coherence.rs:1:9
+   |
+LL | #![deny(coinductive_overlap_in_coherence)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/did_you_mean/compatible-variants.stderr b/tests/ui/did_you_mean/compatible-variants.stderr
index 7b88d93ead1..f2bbd8ced8f 100644
--- a/tests/ui/did_you_mean/compatible-variants.stderr
+++ b/tests/ui/did_you_mean/compatible-variants.stderr
@@ -61,6 +61,8 @@ LL +     Some(())
 error[E0308]: `?` operator has incompatible types
   --> $DIR/compatible-variants.rs:35:5
    |
+LL | fn d() -> Option<()> {
+   |           ---------- expected `Option<()>` because of return type
 LL |     c()?
    |     ^^^^ expected `Option<()>`, found `()`
    |
diff --git a/tests/ui/generic-associated-types/issue-102114.stderr b/tests/ui/generic-associated-types/issue-102114.current.stderr
index 8e41dee54d7..6e7a0b1f67f 100644
--- a/tests/ui/generic-associated-types/issue-102114.stderr
+++ b/tests/ui/generic-associated-types/issue-102114.current.stderr
@@ -1,5 +1,5 @@
 error[E0049]: type `B` has 1 type parameter but its trait declaration has 0 type parameters
-  --> $DIR/issue-102114.rs:11:12
+  --> $DIR/issue-102114.rs:14:12
    |
 LL |     type B<'b>;
    |            -- expected 0 type parameters
diff --git a/tests/ui/generic-associated-types/issue-102114.next.stderr b/tests/ui/generic-associated-types/issue-102114.next.stderr
new file mode 100644
index 00000000000..6e7a0b1f67f
--- /dev/null
+++ b/tests/ui/generic-associated-types/issue-102114.next.stderr
@@ -0,0 +1,12 @@
+error[E0049]: type `B` has 1 type parameter but its trait declaration has 0 type parameters
+  --> $DIR/issue-102114.rs:14:12
+   |
+LL |     type B<'b>;
+   |            -- expected 0 type parameters
+...
+LL |     type B<T> = Wrapper<T>;
+   |            ^ found 1 type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0049`.
diff --git a/tests/ui/generic-associated-types/issue-102114.rs b/tests/ui/generic-associated-types/issue-102114.rs
index de31737efef..bb6622c0a5f 100644
--- a/tests/ui/generic-associated-types/issue-102114.rs
+++ b/tests/ui/generic-associated-types/issue-102114.rs
@@ -1,3 +1,6 @@
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
+
 trait A {
     type B<'b>;
     fn a() -> Self::B<'static>;
diff --git a/tests/ui/generic-associated-types/issue-86218.rs b/tests/ui/generic-associated-types/issue-86218.rs
index 61cfdd35a89..397a0f2c649 100644
--- a/tests/ui/generic-associated-types/issue-86218.rs
+++ b/tests/ui/generic-associated-types/issue-86218.rs
@@ -17,7 +17,6 @@ trait Yay<AdditionalValue> {
 
 impl<'a> Yay<&'a ()> for () {
     type InnerStream<'s> = impl Stream<Item = i32> + 's;
-    //^ ERROR does not fulfill the required lifetime
     fn foo<'s>() -> Self::InnerStream<'s> {
         ()
     }
diff --git a/tests/ui/generic-associated-types/issue-90014-tait.rs b/tests/ui/generic-associated-types/issue-90014-tait.rs
index bc3a4e12965..1ce5cd31987 100644
--- a/tests/ui/generic-associated-types/issue-90014-tait.rs
+++ b/tests/ui/generic-associated-types/issue-90014-tait.rs
@@ -13,7 +13,6 @@ struct Foo<'a>(&'a mut ());
 
 impl Foo<'_> {
     type Fut<'a> = impl Future<Output = ()>;
-    //^ ERROR: the type `&mut ()` does not fulfill the required lifetime
 
     fn make_fut<'a>(&'a self) -> Self::Fut<'a> {
         async { () }
diff --git a/tests/ui/generic-associated-types/issue-90014-tait.stderr b/tests/ui/generic-associated-types/issue-90014-tait.stderr
index 8330a387ecd..1dec7edce50 100644
--- a/tests/ui/generic-associated-types/issue-90014-tait.stderr
+++ b/tests/ui/generic-associated-types/issue-90014-tait.stderr
@@ -1,18 +1,18 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-90014-tait.rs:19:9
+  --> $DIR/issue-90014-tait.rs:18:9
    |
 LL |     type Fut<'a> = impl Future<Output = ()>;
    |                    ------------------------ the expected future
-...
+LL |
 LL |     fn make_fut<'a>(&'a self) -> Self::Fut<'a> {
    |                                  ------------- expected `Foo<'_>::Fut<'a>` because of return type
 LL |         async { () }
    |         ^^^^^^^^^^^^ expected future, found `async` block
    |
    = note: expected opaque type `Foo<'_>::Fut<'a>`
-            found `async` block `[async block@$DIR/issue-90014-tait.rs:19:9: 19:21]`
+            found `async` block `[async block@$DIR/issue-90014-tait.rs:18:9: 18:21]`
 note: this item must have the opaque type in its signature in order to be able to register hidden types
-  --> $DIR/issue-90014-tait.rs:18:8
+  --> $DIR/issue-90014-tait.rs:17:8
    |
 LL |     fn make_fut<'a>(&'a self) -> Self::Fut<'a> {
    |        ^^^^^^^^
diff --git a/tests/ui/higher-ranked/subtype/placeholder-pattern-fail.stderr b/tests/ui/higher-ranked/subtype/placeholder-pattern-fail.stderr
index 73b0a317364..5241b475d5c 100644
--- a/tests/ui/higher-ranked/subtype/placeholder-pattern-fail.stderr
+++ b/tests/ui/higher-ranked/subtype/placeholder-pattern-fail.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/placeholder-pattern-fail.rs:9:47
    |
 LL |     let _: for<'a, 'b> fn(Inv<'a>, Inv<'b>) = sub;
-   |                                               ^^^ one type is more general than the other
+   |            --------------------------------   ^^^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b> fn(Inv<'a>, Inv<'b>)`
               found fn pointer `for<'a> fn(Inv<'a>, Inv<'a>)`
diff --git a/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-fn.stderr b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-fn.stderr
index 9914783d976..db5fc4bf1ba 100644
--- a/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-fn.stderr
+++ b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-fn.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/hrtb-exists-forall-fn.rs:17:34
    |
 LL |     let _: for<'b> fn(&'b u32) = foo();
-   |                                  ^^^^^ one type is more general than the other
+   |            -------------------   ^^^^^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'b> fn(&'b u32)`
               found fn pointer `fn(&u32)`
diff --git a/tests/ui/inline-const/pat-match-fndef.rs b/tests/ui/inline-const/pat-match-fndef.rs
new file mode 100644
index 00000000000..fbd4dc66c3a
--- /dev/null
+++ b/tests/ui/inline-const/pat-match-fndef.rs
@@ -0,0 +1,13 @@
+#![feature(inline_const_pat)]
+//~^ WARN the feature `inline_const_pat` is incomplete
+
+fn uwu() {}
+
+fn main() {
+    let x = [];
+    match x[123] {
+        const { uwu } => {}
+        //~^ ERROR `fn() {uwu}` cannot be used in patterns
+        _ => {}
+    }
+}
diff --git a/tests/ui/inline-const/pat-match-fndef.stderr b/tests/ui/inline-const/pat-match-fndef.stderr
new file mode 100644
index 00000000000..c94782b17ce
--- /dev/null
+++ b/tests/ui/inline-const/pat-match-fndef.stderr
@@ -0,0 +1,17 @@
+warning: the feature `inline_const_pat` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/pat-match-fndef.rs:1:12
+   |
+LL | #![feature(inline_const_pat)]
+   |            ^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #76001 <https://github.com/rust-lang/rust/issues/76001> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: `fn() {uwu}` cannot be used in patterns
+  --> $DIR/pat-match-fndef.rs:9:9
+   |
+LL |         const { uwu } => {}
+   |         ^^^^^^^^^^^^^
+
+error: aborting due to previous error; 1 warning emitted
+
diff --git a/tests/ui/internal/internal-unstable.rs b/tests/ui/internal/internal-unstable.rs
index b8987d3e13c..1eb27fbdc3a 100644
--- a/tests/ui/internal/internal-unstable.rs
+++ b/tests/ui/internal/internal-unstable.rs
@@ -8,7 +8,6 @@ extern crate internal_unstable;
 
 struct Baz {
     #[allow_internal_unstable]
-    //^ WARN `#[allow_internal_unstable]` is ignored on struct fields and match arms
     baz: u8,
 }
 
@@ -50,7 +49,6 @@ fn main() {
 
     match true {
         #[allow_internal_unstable]
-        //^ WARN `#[allow_internal_unstable]` is ignored on struct fields and match arms
         _ => {}
     }
 }
diff --git a/tests/ui/internal/internal-unstable.stderr b/tests/ui/internal/internal-unstable.stderr
index f0f9bfb8d23..b7c47365c2d 100644
--- a/tests/ui/internal/internal-unstable.stderr
+++ b/tests/ui/internal/internal-unstable.stderr
@@ -1,5 +1,5 @@
 error[E0658]: use of unstable library feature 'function'
-  --> $DIR/internal-unstable.rs:41:25
+  --> $DIR/internal-unstable.rs:40:25
    |
 LL |     pass_through_allow!(internal_unstable::unstable());
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL |     pass_through_allow!(internal_unstable::unstable());
    = help: add `#![feature(function)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'function'
-  --> $DIR/internal-unstable.rs:43:27
+  --> $DIR/internal-unstable.rs:42:27
    |
 LL |     pass_through_noallow!(internal_unstable::unstable());
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -15,7 +15,7 @@ LL |     pass_through_noallow!(internal_unstable::unstable());
    = help: add `#![feature(function)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'function'
-  --> $DIR/internal-unstable.rs:47:22
+  --> $DIR/internal-unstable.rs:46:22
    |
 LL |     println!("{:?}", internal_unstable::unstable());
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -23,7 +23,7 @@ LL |     println!("{:?}", internal_unstable::unstable());
    = help: add `#![feature(function)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'function'
-  --> $DIR/internal-unstable.rs:49:10
+  --> $DIR/internal-unstable.rs:48:10
    |
 LL |     bar!(internal_unstable::unstable());
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -31,7 +31,7 @@ LL |     bar!(internal_unstable::unstable());
    = help: add `#![feature(function)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'function'
-  --> $DIR/internal-unstable.rs:19:9
+  --> $DIR/internal-unstable.rs:18:9
    |
 LL |         internal_unstable::unstable();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/issues/issue-51632-try-desugar-incompatible-types.stderr b/tests/ui/issues/issue-51632-try-desugar-incompatible-types.stderr
index 7180a3d2426..c92da53dbc4 100644
--- a/tests/ui/issues/issue-51632-try-desugar-incompatible-types.stderr
+++ b/tests/ui/issues/issue-51632-try-desugar-incompatible-types.stderr
@@ -1,6 +1,8 @@
 error[E0308]: `?` operator has incompatible types
   --> $DIR/issue-51632-try-desugar-incompatible-types.rs:8:5
    |
+LL | fn forbidden_narratives() -> Result<isize, ()> {
+   |                              ----------------- expected `Result<isize, ()>` because of return type
 LL |     missing_discourses()?
    |     ^^^^^^^^^^^^^^^^^^^^^ expected `Result<isize, ()>`, found `isize`
    |
diff --git a/tests/ui/lint/unknown-lints/allow-in-other-module.rs b/tests/ui/lint/unknown-lints/allow-in-other-module.rs
new file mode 100644
index 00000000000..20bf0d7af03
--- /dev/null
+++ b/tests/ui/lint/unknown-lints/allow-in-other-module.rs
@@ -0,0 +1,26 @@
+// check-pass
+
+// Tests that the unknown_lints lint doesn't fire for an unknown lint loaded from a separate file.
+// The key part is that the stderr output should be empty.
+// Reported in https://github.com/rust-lang/rust/issues/84936
+// Fixed incidentally by https://github.com/rust-lang/rust/pull/97266
+
+// This `allow` should apply to submodules, whether they are inline or loaded from a file.
+#![allow(unknown_lints)]
+#![allow(dead_code)]
+// no warning
+#![allow(not_a_real_lint)]
+
+mod other;
+
+// no warning
+#[allow(not_a_real_lint)]
+fn m() {}
+
+mod mm {
+    // no warning
+    #[allow(not_a_real_lint)]
+    fn m() {}
+}
+
+fn main() {}
diff --git a/tests/ui/lint/unknown-lints/other.rs b/tests/ui/lint/unknown-lints/other.rs
new file mode 100644
index 00000000000..a5111c00a3e
--- /dev/null
+++ b/tests/ui/lint/unknown-lints/other.rs
@@ -0,0 +1,10 @@
+// ignore-test
+
+// Companion to allow-in-other-module.rs
+
+// This should not warn.
+#![allow(not_a_real_lint)]
+
+// This should not warn, either.
+#[allow(not_a_real_lint)]
+fn m() {}
diff --git a/tests/ui/macros/assert-eq-macro-msg.rs b/tests/ui/macros/assert-eq-macro-msg.rs
index cb21d5e7ed6..3d921f40072 100644
--- a/tests/ui/macros/assert-eq-macro-msg.rs
+++ b/tests/ui/macros/assert-eq-macro-msg.rs
@@ -1,7 +1,7 @@
 // run-fail
-// error-pattern:assertion failed: `(left == right)`
-// error-pattern: left: `2`
-// error-pattern:right: `3`: 1 + 1 definitely should be 3
+// error-pattern:assertion `left == right` failed: 1 + 1 definitely should be 3
+// error-pattern:  left: 2
+// error-pattern: right: 3
 // ignore-emscripten no processes
 
 fn main() {
diff --git a/tests/ui/macros/assert-eq-macro-panic.rs b/tests/ui/macros/assert-eq-macro-panic.rs
index 5e505c30b35..6745290cbfc 100644
--- a/tests/ui/macros/assert-eq-macro-panic.rs
+++ b/tests/ui/macros/assert-eq-macro-panic.rs
@@ -1,7 +1,7 @@
 // run-fail
-// error-pattern:assertion failed: `(left == right)`
-// error-pattern: left: `14`
-// error-pattern:right: `15`
+// error-pattern:assertion `left == right` failed
+// error-pattern:  left: 14
+// error-pattern: right: 15
 // ignore-emscripten no processes
 
 fn main() {
diff --git a/tests/ui/macros/assert-matches-macro-msg.rs b/tests/ui/macros/assert-matches-macro-msg.rs
index 0f63de6cfff..7af6a077843 100644
--- a/tests/ui/macros/assert-matches-macro-msg.rs
+++ b/tests/ui/macros/assert-matches-macro-msg.rs
@@ -1,7 +1,7 @@
 // run-fail
-// error-pattern:assertion failed: `(left matches right)`
-// error-pattern: left: `2`
-// error-pattern:right: `3`: 1 + 1 definitely should be 3
+// error-pattern:assertion `left matches right` failed: 1 + 1 definitely should be 3
+// error-pattern:  left: 2
+// error-pattern: right: 3
 // ignore-emscripten no processes
 
 #![feature(assert_matches)]
diff --git a/tests/ui/macros/assert-ne-macro-msg.rs b/tests/ui/macros/assert-ne-macro-msg.rs
index 7e390d24a23..adda0af88f2 100644
--- a/tests/ui/macros/assert-ne-macro-msg.rs
+++ b/tests/ui/macros/assert-ne-macro-msg.rs
@@ -1,7 +1,7 @@
 // run-fail
-// error-pattern:assertion failed: `(left != right)`
-// error-pattern: left: `2`
-// error-pattern:right: `2`: 1 + 1 definitely should not be 2
+// error-pattern:assertion `left != right` failed: 1 + 1 definitely should not be 2
+// error-pattern:  left: 2
+// error-pattern: right: 2
 // ignore-emscripten no processes
 
 fn main() {
diff --git a/tests/ui/macros/assert-ne-macro-panic.rs b/tests/ui/macros/assert-ne-macro-panic.rs
index 4f507d7b54d..d977473a2de 100644
--- a/tests/ui/macros/assert-ne-macro-panic.rs
+++ b/tests/ui/macros/assert-ne-macro-panic.rs
@@ -1,7 +1,7 @@
 // run-fail
-// error-pattern:assertion failed: `(left != right)`
-// error-pattern: left: `14`
-// error-pattern:right: `14`
+// error-pattern:assertion `left != right` failed
+// error-pattern:  left: 14
+// error-pattern: right: 14
 // ignore-emscripten no processes
 
 fn main() {
diff --git a/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.rs b/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.rs
new file mode 100644
index 00000000000..85b1ef7555e
--- /dev/null
+++ b/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.rs
@@ -0,0 +1,21 @@
+#![allow(unused)]
+
+fn test(shouldwe: Option<u32>, shouldwe2: Option<u32>) -> u32 {
+    //~^ NOTE expected `u32` because of return type
+    match shouldwe {
+        Some(val) => {
+            match shouldwe2 {
+                Some(val) => {
+                    return val;
+                }
+                None => (), //~ ERROR mismatched types
+                //~^ NOTE expected `u32`, found `()`
+            }
+        }
+        None => return 12,
+    }
+}
+
+fn main() {
+    println!("returned {}", test(None, Some(5)));
+}
diff --git a/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.stderr b/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.stderr
new file mode 100644
index 00000000000..e6d93b8b5f5
--- /dev/null
+++ b/tests/ui/match/non-first-arm-doesnt-match-expected-return-type.stderr
@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/non-first-arm-doesnt-match-expected-return-type.rs:11:25
+   |
+LL | fn test(shouldwe: Option<u32>, shouldwe2: Option<u32>) -> u32 {
+   |                                                           --- expected `u32` because of return type
+...
+LL |                 None => (),
+   |                         ^^ expected `u32`, found `()`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/parser/issues/issue-70583-block-is-empty-2.rs b/tests/ui/parser/issues/issue-70583-block-is-empty-2.rs
index 80f53338a68..92ff0ef643e 100644
--- a/tests/ui/parser/issues/issue-70583-block-is-empty-2.rs
+++ b/tests/ui/parser/issues/issue-70583-block-is-empty-2.rs
@@ -6,9 +6,13 @@ pub enum ErrorHandled {
 impl ErrorHandled {
     pub fn assert_reported(self) {
         match self {
+            //~^ NOTE this delimiter might not be properly closed...
             ErrorHandled::Reported => {}}
-                                     //^~ ERROR block is empty, you might have not meant to close it
+                                     //~^ NOTE block is empty, you might have not meant to close it
+                                     //~| NOTE as it matches this but it has different indentation
             ErrorHandled::TooGeneric => panic!(),
         }
     }
-} //~ ERROR unexpected closing delimiter: `}`
+}
+//~^ ERROR unexpected closing delimiter: `}`
+//~| NOTE unexpected closing delimiter
diff --git a/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr b/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
index 9ae94c70186..c590e04bb3d 100644
--- a/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
+++ b/tests/ui/parser/issues/issue-70583-block-is-empty-2.stderr
@@ -1,8 +1,9 @@
 error: unexpected closing delimiter: `}`
-  --> $DIR/issue-70583-block-is-empty-2.rs:14:1
+  --> $DIR/issue-70583-block-is-empty-2.rs:16:1
    |
 LL |         match self {
    |                    - this delimiter might not be properly closed...
+LL |
 LL |             ErrorHandled::Reported => {}}
    |                                       --- ...as it matches this but it has different indentation
    |                                       |
diff --git a/tests/ui/regions/higher-ranked-implied.stderr b/tests/ui/regions/higher-ranked-implied.stderr
index 9d80eacd7c3..8fa65f11667 100644
--- a/tests/ui/regions/higher-ranked-implied.stderr
+++ b/tests/ui/regions/higher-ranked-implied.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/higher-ranked-implied.rs:12:16
    |
 LL |     let y: B = x;
-   |                ^ one type is more general than the other
+   |            -   ^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>)`
               found fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>)`
@@ -11,7 +13,9 @@ error[E0308]: mismatched types
   --> $DIR/higher-ranked-implied.rs:13:16
    |
 LL |     let _: A = y;
-   |                ^ one type is more general than the other
+   |            -   ^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>)`
               found fn pointer `for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>)`
diff --git a/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr b/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
index bb5bc6f66a5..f2328cf3b24 100644
--- a/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
+++ b/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/region-lifetime-bounds-on-fns-where-clause.rs:20:43
    |
 LL |     let _: fn(&mut &isize, &mut &isize) = a;
-   |                                           ^ one type is more general than the other
+   |            ----------------------------   ^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b isize, &'c mut &'d isize)`
                  found fn item `for<'a, 'b> fn(&'a mut &isize, &'b mut &isize) {a::<'_, '_>}`
diff --git a/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr b/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
index dbe9e9b1a2e..9c5004981d5 100644
--- a/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
+++ b/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/region-multiple-lifetime-bounds-on-fns-where-clause.rs:22:56
    |
 LL |     let _: fn(&mut &isize, &mut &isize, &mut &isize) = a;
-   |                                                        ^ one type is more general than the other
+   |            -----------------------------------------   ^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b, 'c, 'd, 'e, 'f> fn(&'a mut &'b isize, &'c mut &'d isize, &'e mut &'f isize)`
                  found fn item `for<'a, 'b, 'c> fn(&'a mut &isize, &'b mut &isize, &'c mut &isize) {a::<'_, '_, '_>}`
diff --git a/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr b/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
index df0fd069edc..2fab2986567 100644
--- a/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
+++ b/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
@@ -2,7 +2,9 @@ error[E0308]: mismatched types
   --> $DIR/regions-lifetime-bounds-on-fns.rs:20:43
    |
 LL |     let _: fn(&mut &isize, &mut &isize) = a;
-   |                                           ^ one type is more general than the other
+   |            ----------------------------   ^ one type is more general than the other
+   |            |
+   |            expected due to this
    |
    = note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b isize, &'c mut &'d isize)`
                  found fn item `for<'a, 'b> fn(&'a mut &isize, &'b mut &isize) {a::<'_, '_>}`
diff --git a/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
index 721890db4fb..c27e8c4b019 100644
--- a/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
+++ b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
@@ -1,5 +1,7 @@
 // Check that we can manually implement an object-unsafe trait for its trait object.
 
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
 // run-pass
 
 #![feature(object_safe_for_dispatch)]
diff --git a/tests/ui/std/slice-from-array-issue-113238.rs b/tests/ui/std/slice-from-array-issue-113238.rs
new file mode 100644
index 00000000000..e9e1bfb8db3
--- /dev/null
+++ b/tests/ui/std/slice-from-array-issue-113238.rs
@@ -0,0 +1,9 @@
+// check-pass
+
+// This intends to use the unsizing coercion from array to slice, but it only
+// works if we resolve `<&[u8]>::from` as the reflexive `From<T> for T`. In
+// #113238, we found that gimli had added its own `From<EndianSlice> for &[u8]`
+// that affected all `std/backtrace` users.
+fn main() {
+    let _ = <&[u8]>::from(&[]);
+}
diff --git a/tests/ui/suggestions/issue-114701.rs b/tests/ui/suggestions/issue-114701.rs
new file mode 100644
index 00000000000..81d7803ec8c
--- /dev/null
+++ b/tests/ui/suggestions/issue-114701.rs
@@ -0,0 +1,15 @@
+enum Enum<T> { SVariant { v: T }, UVariant }
+
+macro_rules! is_variant {
+    (TSVariant, ) => (!);
+    (SVariant, ) => (!);
+    (UVariant, $expr:expr) => (is_variant!(@check UVariant, {}, $expr));
+    (@check $variant:ident, $matcher:tt, $expr:expr) => (
+        assert!(if let Enum::$variant::<()> $matcher = $expr () { true } else { false },
+                );
+    );
+}
+
+fn main() {
+    is_variant!(UVariant, Enum::<()>::UVariant); //~ ERROR expected function
+}
diff --git a/tests/ui/suggestions/issue-114701.stderr b/tests/ui/suggestions/issue-114701.stderr
new file mode 100644
index 00000000000..67462a09c78
--- /dev/null
+++ b/tests/ui/suggestions/issue-114701.stderr
@@ -0,0 +1,15 @@
+error[E0618]: expected function, found `Enum<()>`
+  --> $DIR/issue-114701.rs:14:27
+   |
+LL | enum Enum<T> { SVariant { v: T }, UVariant }
+   |                                   -------- `Enum::UVariant` defined here
+...
+LL |         assert!(if let Enum::$variant::<()> $matcher = $expr () { true } else { false },
+   |                                                        -------- call expression requires function
+...
+LL |     is_variant!(UVariant, Enum::<()>::UVariant);
+   |                           ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0618`.
diff --git a/tests/ui/suggestions/remove-question-symbol-with-paren.stderr b/tests/ui/suggestions/remove-question-symbol-with-paren.stderr
index 39e35f733a1..40b9cf2dcd4 100644
--- a/tests/ui/suggestions/remove-question-symbol-with-paren.stderr
+++ b/tests/ui/suggestions/remove-question-symbol-with-paren.stderr
@@ -1,6 +1,9 @@
 error[E0308]: `?` operator has incompatible types
   --> $DIR/remove-question-symbol-with-paren.rs:5:6
    |
+LL | fn foo() -> Option<()> {
+   |             ---------- expected `Option<()>` because of return type
+LL |     let x = Some(());
 LL |     (x?)
    |      ^^ expected `Option<()>`, found `()`
    |
diff --git a/tests/ui/test-attrs/test-panic-abort-nocapture.run.stderr b/tests/ui/test-attrs/test-panic-abort-nocapture.run.stderr
index 8c3f5a07f56..6997833834d 100644
--- a/tests/ui/test-attrs/test-panic-abort-nocapture.run.stderr
+++ b/tests/ui/test-attrs/test-panic-abort-nocapture.run.stderr
@@ -1,11 +1,11 @@
 thread 'main' panicked at $DIR/test-panic-abort-nocapture.rs:33:5:
-assertion failed: `(left == right)`
-  left: `2`,
- right: `4`
+assertion `left == right` failed
+  left: 2
+ right: 4
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 thread 'main' panicked at $DIR/test-panic-abort-nocapture.rs:27:5:
-assertion failed: `(left == right)`
-  left: `2`,
- right: `4`
+assertion `left == right` failed
+  left: 2
+ right: 4
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 testing321
diff --git a/tests/ui/test-attrs/test-panic-abort.run.stdout b/tests/ui/test-attrs/test-panic-abort.run.stdout
index 785407dfa0b..0e27f6fb655 100644
--- a/tests/ui/test-attrs/test-panic-abort.run.stdout
+++ b/tests/ui/test-attrs/test-panic-abort.run.stdout
@@ -18,9 +18,9 @@ testing123
 ---- it_fails stderr ----
 testing321
 thread 'main' panicked at $DIR/test-panic-abort.rs:38:5:
-assertion failed: `(left == right)`
-  left: `2`,
- right: `5`
+assertion `left == right` failed
+  left: 2
+ right: 5
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 
 
diff --git a/tests/ui/traits/issue-105231.rs b/tests/ui/traits/issue-105231.rs
index 74c7afd6b9e..bb2b13664ba 100644
--- a/tests/ui/traits/issue-105231.rs
+++ b/tests/ui/traits/issue-105231.rs
@@ -1,9 +1,9 @@
-//~ ERROR overflow evaluating the requirement `A<A<A<A<A<A<A<...>>>>>>>: Send`
 struct A<T>(B<T>);
 //~^ ERROR recursive types `A` and `B` have infinite size
 struct B<T>(A<A<T>>);
 trait Foo {}
 impl<T> Foo for T where T: Send {}
+//~^ ERROR overflow evaluating the requirement `A<A<A<A<A<A<A<...>>>>>>>: Send`
 impl Foo for B<u8> {}
 
 fn main() {}
diff --git a/tests/ui/traits/issue-105231.stderr b/tests/ui/traits/issue-105231.stderr
index fe20c47c57a..76a71067353 100644
--- a/tests/ui/traits/issue-105231.stderr
+++ b/tests/ui/traits/issue-105231.stderr
@@ -1,5 +1,5 @@
 error[E0072]: recursive types `A` and `B` have infinite size
-  --> $DIR/issue-105231.rs:2:1
+  --> $DIR/issue-105231.rs:1:1
    |
 LL | struct A<T>(B<T>);
    | ^^^^^^^^^^^ ---- recursive without indirection
@@ -15,10 +15,14 @@ LL ~ struct B<T>(Box<A<A<T>>>);
    |
 
 error[E0275]: overflow evaluating the requirement `A<A<A<A<A<A<A<...>>>>>>>: Send`
+  --> $DIR/issue-105231.rs:5:28
+   |
+LL | impl<T> Foo for T where T: Send {}
+   |                            ^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_105231`)
 note: required because it appears within the type `B<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<A<u8>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
-  --> $DIR/issue-105231.rs:4:8
+  --> $DIR/issue-105231.rs:3:8
    |
 LL | struct B<T>(A<A<T>>);
    |        ^
diff --git a/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.rs b/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.rs
index d37943b929a..206ab07898b 100644
--- a/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.rs
+++ b/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.rs
@@ -1,4 +1,3 @@
-//~ ERROR overflow
 // A regression test for #111729 checking that we correctly
 // track recursion depth for obligations returned by confirmation.
 use std::panic::RefUnwindSafe;
@@ -15,6 +14,7 @@ struct RootDatabase {
 }
 
 impl<T: RefUnwindSafe> Database for T {
+    //~^ ERROR overflow
     type Storage = SalsaStorage;
 }
 impl Database for RootDatabase {
diff --git a/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.stderr b/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.stderr
index 8f9ce3ef1e9..4123a8199a0 100644
--- a/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.stderr
+++ b/tests/ui/traits/solver-cycles/cycle-via-builtin-auto-trait-impl.stderr
@@ -1,13 +1,17 @@
 error[E0275]: overflow evaluating the requirement `Runtime<RootDatabase>: RefUnwindSafe`
+  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:16:9
+   |
+LL | impl<T: RefUnwindSafe> Database for T {
+   |         ^^^^^^^^^^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`cycle_via_builtin_auto_trait_impl`)
 note: required because it appears within the type `RootDatabase`
-  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:13:8
+  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:12:8
    |
 LL | struct RootDatabase {
    |        ^^^^^^^^^^^^
 note: required for `RootDatabase` to implement `Database`
-  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:17:24
+  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:16:24
    |
 LL | impl<T: RefUnwindSafe> Database for T {
    |         -------------  ^^^^^^^^     ^
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.stderr b/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr
index 82b4e9bd72a..d48d9b89d1d 100644
--- a/tests/ui/traits/trait-upcasting/type-checking-test-1.stderr
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr
@@ -1,5 +1,5 @@
 error[E0605]: non-primitive cast: `&dyn Foo` as `&dyn Bar<_>`
-  --> $DIR/type-checking-test-1.rs:16:13
+  --> $DIR/type-checking-test-1.rs:19:13
    |
 LL |     let _ = x as &dyn Bar<_>; // Ambiguous
    |             ^^^^^^^^^^^^^^^^ invalid cast
@@ -10,7 +10,7 @@ LL |     let _ = &x as &dyn Bar<_>; // Ambiguous
    |             +
 
 error[E0277]: the trait bound `&dyn Foo: Bar<_>` is not satisfied
-  --> $DIR/type-checking-test-1.rs:16:13
+  --> $DIR/type-checking-test-1.rs:19:13
    |
 LL |     let _ = x as &dyn Bar<_>; // Ambiguous
    |             ^ the trait `Bar<_>` is not implemented for `&dyn Foo`
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr b/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr
new file mode 100644
index 00000000000..b612005fcb0
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr
@@ -0,0 +1,9 @@
+error[E0605]: non-primitive cast: `&dyn Foo` as `&dyn Bar<_>`
+  --> $DIR/type-checking-test-1.rs:19:13
+   |
+LL |     let _ = x as &dyn Bar<_>; // Ambiguous
+   |             ^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0605`.
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.rs b/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
index 6bc9f4a75d3..7c7beec0809 100644
--- a/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
@@ -1,3 +1,6 @@
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
+
 #![feature(trait_upcasting)]
 
 trait Foo: Bar<i32> + Bar<u32> {}
@@ -15,7 +18,7 @@ fn test_specific(x: &dyn Foo) {
 fn test_unknown_version(x: &dyn Foo) {
     let _ = x as &dyn Bar<_>; // Ambiguous
                               //~^ ERROR non-primitive cast
-                              //~^^ ERROR the trait bound `&dyn Foo: Bar<_>` is not satisfied
+                              //[current]~^^ ERROR the trait bound `&dyn Foo: Bar<_>` is not satisfied
 }
 
 fn test_infer_version(x: &dyn Foo) {
diff --git a/tests/ui/unsized/issue-75899.rs b/tests/ui/unsized/issue-75899.rs
index abff17e11b5..71943103291 100644
--- a/tests/ui/unsized/issue-75899.rs
+++ b/tests/ui/unsized/issue-75899.rs
@@ -1,3 +1,5 @@
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
 // check-pass
 
 trait Trait {}
diff --git a/tests/ui/where-clauses/where-clause-bounds-inconsistency.rs b/tests/ui/where-clauses/where-clause-bounds-inconsistency.rs
index cf7d06b6179..ea60fa70876 100644
--- a/tests/ui/where-clauses/where-clause-bounds-inconsistency.rs
+++ b/tests/ui/where-clauses/where-clause-bounds-inconsistency.rs
@@ -14,7 +14,6 @@ trait Trait {
 
 impl Trait for bool {
     fn a<T: Bound>(&self, _: T) {}
-    //^~ This gets rejected but should be accepted
     fn b<T>(&self, _: T) where T: Bound {}
     fn c<T: Bound>(&self, _: T) {}
     fn d<T>(&self, _: T) where T: Bound {}