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authorbors <bors@rust-lang.org>2024-01-19 08:42:17 +0000
committerbors <bors@rust-lang.org>2024-01-19 08:42:17 +0000
commit92d727796be7c882d2efbc06e08bbf4743cf29dc (patch)
treedfa01ef8715c67165d86640add0cdd9f89aa8a18
parent16fadb3f252bcfc5ee3f0be09472c9600a052202 (diff)
parent9c6795baab8bc343c8573ea4ea4c2b550f6bc0ac (diff)
downloadrust-92d727796be7c882d2efbc06e08bbf4743cf29dc.tar.gz
rust-92d727796be7c882d2efbc06e08bbf4743cf29dc.zip
Auto merge of #120112 - matthiaskrgr:rollup-48o3919, r=matthiaskrgr
Rollup of 9 pull requests

Successful merges:

 - #119582 (bootstrap: handle vendored sources when remapping crate paths)
 - #119730 (docs: fix typos)
 - #119828 (Improved collapse_debuginfo attribute, added command-line flag)
 - #119869 (replace `track_errors` usages with bubbling up `ErrorGuaranteed`)
 - #120037 (Remove `next_root_ty_var`)
 - #120094 (tests/ui/asm/inline-syntax: adapt for LLVM 18)
 - #120096 (Set RUSTC_BOOTSTRAP=1 consistently)
 - #120101 (change `.unwrap()` to `?` on write where `fmt::Result` is returned)
 - #120102 (Fix typo in munmap_partial.rs)

r? `@ghost`
`@rustbot` modify labels: rollup
-rw-r--r--compiler/rustc_expand/messages.ftl3
-rw-r--r--compiler/rustc_expand/src/base.rs56
-rw-r--r--compiler/rustc_expand/src/errors.rs7
-rw-r--r--compiler/rustc_expand/src/mbe/macro_rules.rs1
-rw-r--r--compiler/rustc_feature/src/builtin_attrs.rs2
-rw-r--r--compiler/rustc_hir_analysis/src/astconv/mod.rs2
-rw-r--r--compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs79
-rw-r--r--compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs48
-rw-r--r--compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs8
-rw-r--r--compiler/rustc_hir_analysis/src/impl_wf_check.rs46
-rw-r--r--compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs132
-rw-r--r--compiler/rustc_hir_analysis/src/lib.rs32
-rw-r--r--compiler/rustc_hir_analysis/src/outlives/test.rs8
-rw-r--r--compiler/rustc_hir_analysis/src/variance/test.rs13
-rw-r--r--compiler/rustc_hir_typeck/src/closure.rs4
-rw-r--r--compiler/rustc_hir_typeck/src/expr.rs3
-rw-r--r--compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs4
-rw-r--r--compiler/rustc_hir_typeck/src/method/probe.rs6
-rw-r--r--compiler/rustc_hir_typeck/src/method/suggest.rs19
-rw-r--r--compiler/rustc_interface/src/tests.rs9
-rw-r--r--compiler/rustc_metadata/src/rmeta/decoder.rs1
-rw-r--r--compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs4
-rw-r--r--compiler/rustc_metadata/src/rmeta/encoder.rs4
-rw-r--r--compiler/rustc_middle/src/arena.rs1
-rw-r--r--compiler/rustc_middle/src/mir/pretty.rs4
-rw-r--r--compiler/rustc_middle/src/query/erase.rs4
-rw-r--r--compiler/rustc_middle/src/query/mod.rs16
-rw-r--r--compiler/rustc_middle/src/query/plumbing.rs12
-rw-r--r--compiler/rustc_middle/src/ty/mod.rs3
-rw-r--r--compiler/rustc_middle/src/ty/trait_def.rs18
-rw-r--r--compiler/rustc_monomorphize/src/collector.rs2
-rw-r--r--compiler/rustc_resolve/src/late/diagnostics.rs6
-rw-r--r--compiler/rustc_session/src/config.rs32
-rw-r--r--compiler/rustc_session/src/options.rs17
-rw-r--r--compiler/rustc_span/src/hygiene.rs19
-rw-r--r--compiler/rustc_span/src/symbol.rs2
-rw-r--r--src/bootstrap/bootstrap.py19
-rw-r--r--src/bootstrap/src/core/builder.rs19
-rw-r--r--src/librustdoc/clean/inline.rs4
-rw-r--r--src/librustdoc/clean/types.rs4
-rw-r--r--src/librustdoc/passes/collect_intra_doc_links.rs3
-rw-r--r--src/tools/clippy/clippy_lints/src/derive.rs3
-rw-r--r--src/tools/clippy/clippy_lints/src/inherent_impl.rs3
-rw-r--r--src/tools/clippy/clippy_lints/src/iter_without_into_iter.rs2
-rw-r--r--src/tools/clippy/clippy_lints/src/len_zero.rs5
-rw-r--r--src/tools/clippy/clippy_lints/src/methods/or_fun_call.rs3
-rw-r--r--src/tools/clippy/clippy_utils/src/lib.rs8
-rw-r--r--src/tools/miri/tests/fail-dep/shims/munmap_partial.rs2
-rw-r--r--tests/debuginfo/collapse-debuginfo-external-attr.rs31
-rw-r--r--tests/debuginfo/collapse-debuginfo-external-flag-overriden-by-attr.rs34
-rw-r--r--tests/debuginfo/collapse-debuginfo-external-flag.rs26
-rw-r--r--tests/debuginfo/collapse-debuginfo-no-attr.rs2
-rw-r--r--tests/debuginfo/collapse-debuginfo-with-yes-flag.rs57
-rw-r--r--tests/rustdoc-ui/error-in-impl-trait/README.md2
-rw-r--r--tests/ui/asm/inline-syntax.arm.stderr12
-rw-r--r--tests/ui/asm/inline-syntax.arm_llvm_18.stderr90
-rw-r--r--tests/ui/asm/inline-syntax.rs14
-rw-r--r--tests/ui/asm/inline-syntax.x86_64.stderr14
-rw-r--r--tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs2
-rw-r--r--tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr26
-rw-r--r--tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr14
61 files changed, 771 insertions, 255 deletions
diff --git a/compiler/rustc_expand/messages.ftl b/compiler/rustc_expand/messages.ftl
index 475dd348e7b..3e3b4814300 100644
--- a/compiler/rustc_expand/messages.ftl
+++ b/compiler/rustc_expand/messages.ftl
@@ -16,6 +16,9 @@ expand_attributes_wrong_form =
 expand_cannot_be_name_of_macro =
     `{$trait_ident}` cannot be a name of {$macro_type} macro
 
+expand_collapse_debuginfo_illegal =
+    illegal value for attribute #[collapse_debuginfo(no|external|yes)]
+
 expand_count_repetition_misplaced =
     `count` can not be placed inside the inner-most repetition
 
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 0a1c4430397..edc9c5a9130 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -1,5 +1,6 @@
 #![deny(rustc::untranslatable_diagnostic)]
 
+use crate::base::ast::NestedMetaItem;
 use crate::errors;
 use crate::expand::{self, AstFragment, Invocation};
 use crate::module::DirOwnership;
@@ -19,6 +20,7 @@ use rustc_feature::Features;
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
 use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, RegisteredTools};
 use rustc_parse::{parser, MACRO_ARGUMENTS};
+use rustc_session::config::CollapseMacroDebuginfo;
 use rustc_session::errors::report_lit_error;
 use rustc_session::{parse::ParseSess, Limit, Session};
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId};
@@ -761,6 +763,55 @@ impl SyntaxExtension {
         }
     }
 
+    fn collapse_debuginfo_by_name(sess: &Session, attr: &Attribute) -> CollapseMacroDebuginfo {
+        use crate::errors::CollapseMacroDebuginfoIllegal;
+        // #[collapse_debuginfo] without enum value (#[collapse_debuginfo(no/external/yes)])
+        // considered as `yes`
+        attr.meta_item_list().map_or(CollapseMacroDebuginfo::Yes, |l| {
+            let [NestedMetaItem::MetaItem(item)] = &l[..] else {
+                sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: attr.span });
+                return CollapseMacroDebuginfo::Unspecified;
+            };
+            if !item.is_word() {
+                sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: item.span });
+                CollapseMacroDebuginfo::Unspecified
+            } else {
+                match item.name_or_empty() {
+                    sym::no => CollapseMacroDebuginfo::No,
+                    sym::external => CollapseMacroDebuginfo::External,
+                    sym::yes => CollapseMacroDebuginfo::Yes,
+                    _ => {
+                        sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: item.span });
+                        CollapseMacroDebuginfo::Unspecified
+                    }
+                }
+            }
+        })
+    }
+
+    /// if-ext - if macro from different crate (related to callsite code)
+    /// | cmd \ attr    | no  | (unspecified) | external | yes |
+    /// | no            | no  | no            | no       | no  |
+    /// | (unspecified) | no  | no            | if-ext   | yes |
+    /// | external      | no  | if-ext        | if-ext   | yes |
+    /// | yes           | yes | yes           | yes      | yes |
+    fn get_collapse_debuginfo(sess: &Session, attrs: &[ast::Attribute], is_local: bool) -> bool {
+        let collapse_debuginfo_attr = attr::find_by_name(attrs, sym::collapse_debuginfo)
+            .map(|v| Self::collapse_debuginfo_by_name(sess, v))
+            .unwrap_or(CollapseMacroDebuginfo::Unspecified);
+        let flag = sess.opts.unstable_opts.collapse_macro_debuginfo;
+        let attr = collapse_debuginfo_attr;
+        let ext = !is_local;
+        #[rustfmt::skip]
+        let collapse_table = [
+            [false, false, false, false],
+            [false, false, ext,   true],
+            [false, ext,   ext,   true],
+            [true,  true,  true,  true],
+        ];
+        collapse_table[flag as usize][attr as usize]
+    }
+
     /// Constructs a syntax extension with the given properties
     /// and other properties converted from attributes.
     pub fn new(
@@ -772,6 +823,7 @@ impl SyntaxExtension {
         edition: Edition,
         name: Symbol,
         attrs: &[ast::Attribute],
+        is_local: bool,
     ) -> SyntaxExtension {
         let allow_internal_unstable =
             attr::allow_internal_unstable(sess, attrs).collect::<Vec<Symbol>>();
@@ -780,8 +832,8 @@ impl SyntaxExtension {
         let local_inner_macros = attr::find_by_name(attrs, sym::macro_export)
             .and_then(|macro_export| macro_export.meta_item_list())
             .is_some_and(|l| attr::list_contains_name(&l, sym::local_inner_macros));
-        let collapse_debuginfo = attr::contains_name(attrs, sym::collapse_debuginfo);
-        tracing::debug!(?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
+        let collapse_debuginfo = Self::get_collapse_debuginfo(sess, attrs, is_local);
+        tracing::debug!(?name, ?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
 
         let (builtin_name, helper_attrs) = attr::find_by_name(attrs, sym::rustc_builtin_macro)
             .map(|attr| {
diff --git a/compiler/rustc_expand/src/errors.rs b/compiler/rustc_expand/src/errors.rs
index 2b43fae6852..4a1c00f0104 100644
--- a/compiler/rustc_expand/src/errors.rs
+++ b/compiler/rustc_expand/src/errors.rs
@@ -59,6 +59,13 @@ pub(crate) struct ResolveRelativePath {
 }
 
 #[derive(Diagnostic)]
+#[diag(expand_collapse_debuginfo_illegal)]
+pub(crate) struct CollapseMacroDebuginfoIllegal {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
 #[diag(expand_macro_const_stability)]
 pub(crate) struct MacroConstStability {
     #[primary_span]
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index 363b52aef8a..1a39708ed8e 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -367,6 +367,7 @@ pub fn compile_declarative_macro(
             edition,
             def.ident.name,
             &def.attrs,
+            def.id != DUMMY_NODE_ID,
         )
     };
     let dummy_syn_ext = || (mk_syn_ext(Box::new(macro_rules_dummy_expander)), Vec::new());
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 4442b67df6e..68b6f69854d 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -469,7 +469,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
 
     // `#[collapse_debuginfo]`
     gated!(
-        collapse_debuginfo, Normal, template!(Word), WarnFollowing,
+        collapse_debuginfo, Normal, template!(Word, List: "no|external|yes"), ErrorFollowing,
         experimental!(collapse_debuginfo)
     ),
 
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 9f4f1413650..b9e72a3b1ea 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -1446,7 +1446,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         }
 
         let candidates: Vec<_> = tcx
-            .inherent_impls(adt_did)
+            .inherent_impls(adt_did)?
             .iter()
             .filter_map(|&impl_| Some((impl_, self.lookup_assoc_ty_unchecked(name, block, impl_)?)))
             .collect();
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
index 3162004a634..abef365c3ca 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
@@ -13,32 +13,41 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::ty::fast_reject::{simplify_type, SimplifiedType, TreatParams};
 use rustc_middle::ty::{self, CrateInherentImpls, Ty, TyCtxt};
 use rustc_span::symbol::sym;
+use rustc_span::ErrorGuaranteed;
 
 use crate::errors;
 
 /// On-demand query: yields a map containing all types mapped to their inherent impls.
-pub fn crate_inherent_impls(tcx: TyCtxt<'_>, (): ()) -> CrateInherentImpls {
+pub fn crate_inherent_impls(
+    tcx: TyCtxt<'_>,
+    (): (),
+) -> Result<&'_ CrateInherentImpls, ErrorGuaranteed> {
     let mut collect = InherentCollect { tcx, impls_map: Default::default() };
+    let mut res = Ok(());
     for id in tcx.hir().items() {
-        collect.check_item(id);
+        res = res.and(collect.check_item(id));
     }
-    collect.impls_map
+    res?;
+    Ok(tcx.arena.alloc(collect.impls_map))
 }
 
-pub fn crate_incoherent_impls(tcx: TyCtxt<'_>, simp: SimplifiedType) -> &[DefId] {
-    let crate_map = tcx.crate_inherent_impls(());
-    tcx.arena.alloc_from_iter(
+pub fn crate_incoherent_impls(
+    tcx: TyCtxt<'_>,
+    simp: SimplifiedType,
+) -> Result<&[DefId], ErrorGuaranteed> {
+    let crate_map = tcx.crate_inherent_impls(())?;
+    Ok(tcx.arena.alloc_from_iter(
         crate_map.incoherent_impls.get(&simp).unwrap_or(&Vec::new()).iter().map(|d| d.to_def_id()),
-    )
+    ))
 }
 
 /// On-demand query: yields a vector of the inherent impls for a specific type.
-pub fn inherent_impls(tcx: TyCtxt<'_>, ty_def_id: LocalDefId) -> &[DefId] {
-    let crate_map = tcx.crate_inherent_impls(());
-    match crate_map.inherent_impls.get(&ty_def_id) {
+pub fn inherent_impls(tcx: TyCtxt<'_>, ty_def_id: LocalDefId) -> Result<&[DefId], ErrorGuaranteed> {
+    let crate_map = tcx.crate_inherent_impls(())?;
+    Ok(match crate_map.inherent_impls.get(&ty_def_id) {
         Some(v) => &v[..],
         None => &[],
-    }
+    })
 }
 
 struct InherentCollect<'tcx> {
@@ -47,14 +56,19 @@ struct InherentCollect<'tcx> {
 }
 
 impl<'tcx> InherentCollect<'tcx> {
-    fn check_def_id(&mut self, impl_def_id: LocalDefId, self_ty: Ty<'tcx>, ty_def_id: DefId) {
+    fn check_def_id(
+        &mut self,
+        impl_def_id: LocalDefId,
+        self_ty: Ty<'tcx>,
+        ty_def_id: DefId,
+    ) -> Result<(), ErrorGuaranteed> {
         if let Some(ty_def_id) = ty_def_id.as_local() {
             // Add the implementation to the mapping from implementation to base
             // type def ID, if there is a base type for this implementation and
             // the implementation does not have any associated traits.
             let vec = self.impls_map.inherent_impls.entry(ty_def_id).or_default();
             vec.push(impl_def_id.to_def_id());
-            return;
+            return Ok(());
         }
 
         if self.tcx.features().rustc_attrs {
@@ -62,18 +76,16 @@ impl<'tcx> InherentCollect<'tcx> {
 
             if !self.tcx.has_attr(ty_def_id, sym::rustc_has_incoherent_inherent_impls) {
                 let impl_span = self.tcx.def_span(impl_def_id);
-                self.tcx.dcx().emit_err(errors::InherentTyOutside { span: impl_span });
-                return;
+                return Err(self.tcx.dcx().emit_err(errors::InherentTyOutside { span: impl_span }));
             }
 
             for &impl_item in items {
                 if !self.tcx.has_attr(impl_item, sym::rustc_allow_incoherent_impl) {
                     let impl_span = self.tcx.def_span(impl_def_id);
-                    self.tcx.dcx().emit_err(errors::InherentTyOutsideRelevant {
+                    return Err(self.tcx.dcx().emit_err(errors::InherentTyOutsideRelevant {
                         span: impl_span,
                         help_span: self.tcx.def_span(impl_item),
-                    });
-                    return;
+                    }));
                 }
             }
 
@@ -82,24 +94,28 @@ impl<'tcx> InherentCollect<'tcx> {
             } else {
                 bug!("unexpected self type: {:?}", self_ty);
             }
+            Ok(())
         } else {
             let impl_span = self.tcx.def_span(impl_def_id);
-            self.tcx.dcx().emit_err(errors::InherentTyOutsideNew { span: impl_span });
+            Err(self.tcx.dcx().emit_err(errors::InherentTyOutsideNew { span: impl_span }))
         }
     }
 
-    fn check_primitive_impl(&mut self, impl_def_id: LocalDefId, ty: Ty<'tcx>) {
+    fn check_primitive_impl(
+        &mut self,
+        impl_def_id: LocalDefId,
+        ty: Ty<'tcx>,
+    ) -> Result<(), ErrorGuaranteed> {
         let items = self.tcx.associated_item_def_ids(impl_def_id);
         if !self.tcx.hir().rustc_coherence_is_core() {
             if self.tcx.features().rustc_attrs {
                 for &impl_item in items {
                     if !self.tcx.has_attr(impl_item, sym::rustc_allow_incoherent_impl) {
                         let span = self.tcx.def_span(impl_def_id);
-                        self.tcx.dcx().emit_err(errors::InherentTyOutsidePrimitive {
+                        return Err(self.tcx.dcx().emit_err(errors::InherentTyOutsidePrimitive {
                             span,
                             help_span: self.tcx.def_span(impl_item),
-                        });
-                        return;
+                        }));
                     }
                 }
             } else {
@@ -108,8 +124,7 @@ impl<'tcx> InherentCollect<'tcx> {
                 if let ty::Ref(_, subty, _) = ty.kind() {
                     note = Some(errors::InherentPrimitiveTyNote { subty: *subty });
                 }
-                self.tcx.dcx().emit_err(errors::InherentPrimitiveTy { span, note });
-                return;
+                return Err(self.tcx.dcx().emit_err(errors::InherentPrimitiveTy { span, note }));
             }
         }
 
@@ -118,11 +133,12 @@ impl<'tcx> InherentCollect<'tcx> {
         } else {
             bug!("unexpected primitive type: {:?}", ty);
         }
+        Ok(())
     }
 
-    fn check_item(&mut self, id: hir::ItemId) {
+    fn check_item(&mut self, id: hir::ItemId) -> Result<(), ErrorGuaranteed> {
         if !matches!(self.tcx.def_kind(id.owner_id), DefKind::Impl { of_trait: false }) {
-            return;
+            return Ok(());
         }
 
         let id = id.owner_id.def_id;
@@ -132,10 +148,10 @@ impl<'tcx> InherentCollect<'tcx> {
             ty::Adt(def, _) => self.check_def_id(id, self_ty, def.did()),
             ty::Foreign(did) => self.check_def_id(id, self_ty, did),
             ty::Dynamic(data, ..) if data.principal_def_id().is_some() => {
-                self.check_def_id(id, self_ty, data.principal_def_id().unwrap());
+                self.check_def_id(id, self_ty, data.principal_def_id().unwrap())
             }
             ty::Dynamic(..) => {
-                self.tcx.dcx().emit_err(errors::InherentDyn { span: item_span });
+                Err(self.tcx.dcx().emit_err(errors::InherentDyn { span: item_span }))
             }
             ty::Bool
             | ty::Char
@@ -151,7 +167,7 @@ impl<'tcx> InherentCollect<'tcx> {
             | ty::FnPtr(_)
             | ty::Tuple(..) => self.check_primitive_impl(id, self_ty),
             ty::Alias(..) | ty::Param(_) => {
-                self.tcx.dcx().emit_err(errors::InherentNominal { span: item_span });
+                Err(self.tcx.dcx().emit_err(errors::InherentNominal { span: item_span }))
             }
             ty::FnDef(..)
             | ty::Closure(..)
@@ -162,7 +178,8 @@ impl<'tcx> InherentCollect<'tcx> {
             | ty::Infer(_) => {
                 bug!("unexpected impl self type of impl: {:?} {:?}", id, self_ty);
             }
-            ty::Error(_) => {}
+            // We could bail out here, but that will silence other useful errors.
+            ty::Error(_) => Ok(()),
         }
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
index 4c3455c7240..63ea0272014 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
@@ -6,16 +6,18 @@ use rustc_hir::def_id::DefId;
 use rustc_index::IndexVec;
 use rustc_middle::traits::specialization_graph::OverlapMode;
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_span::Symbol;
+use rustc_span::{ErrorGuaranteed, Symbol};
 use rustc_trait_selection::traits::{self, SkipLeakCheck};
 use smallvec::SmallVec;
 use std::collections::hash_map::Entry;
 
-pub fn crate_inherent_impls_overlap_check(tcx: TyCtxt<'_>, (): ()) {
+pub fn crate_inherent_impls_overlap_check(tcx: TyCtxt<'_>, (): ()) -> Result<(), ErrorGuaranteed> {
     let mut inherent_overlap_checker = InherentOverlapChecker { tcx };
+    let mut res = Ok(());
     for id in tcx.hir().items() {
-        inherent_overlap_checker.check_item(id);
+        res = res.and(inherent_overlap_checker.check_item(id));
     }
+    res
 }
 
 struct InherentOverlapChecker<'tcx> {
@@ -58,10 +60,11 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
                 == item2.ident(self.tcx).normalize_to_macros_2_0()
     }
 
-    fn check_for_duplicate_items_in_impl(&self, impl_: DefId) {
+    fn check_for_duplicate_items_in_impl(&self, impl_: DefId) -> Result<(), ErrorGuaranteed> {
         let impl_items = self.tcx.associated_items(impl_);
 
         let mut seen_items = FxHashMap::default();
+        let mut res = Ok(());
         for impl_item in impl_items.in_definition_order() {
             let span = self.tcx.def_span(impl_item.def_id);
             let ident = impl_item.ident(self.tcx);
@@ -70,7 +73,7 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
             match seen_items.entry(norm_ident) {
                 Entry::Occupied(entry) => {
                     let former = entry.get();
-                    struct_span_code_err!(
+                    res = Err(struct_span_code_err!(
                         self.tcx.dcx(),
                         span,
                         E0592,
@@ -79,13 +82,14 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
                     )
                     .with_span_label(span, format!("duplicate definitions for `{ident}`"))
                     .with_span_label(*former, format!("other definition for `{ident}`"))
-                    .emit();
+                    .emit());
                 }
                 Entry::Vacant(entry) => {
                     entry.insert(span);
                 }
             }
         }
+        res
     }
 
     fn check_for_common_items_in_impls(
@@ -93,10 +97,11 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
         impl1: DefId,
         impl2: DefId,
         overlap: traits::OverlapResult<'_>,
-    ) {
+    ) -> Result<(), ErrorGuaranteed> {
         let impl_items1 = self.tcx.associated_items(impl1);
         let impl_items2 = self.tcx.associated_items(impl2);
 
+        let mut res = Ok(());
         for &item1 in impl_items1.in_definition_order() {
             let collision = impl_items2
                 .filter_by_name_unhygienic(item1.name)
@@ -128,9 +133,10 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
                     traits::add_placeholder_note(&mut err);
                 }
 
-                err.emit();
+                res = Err(err.emit());
             }
         }
+        res
     }
 
     fn check_for_overlapping_inherent_impls(
@@ -138,7 +144,7 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
         overlap_mode: OverlapMode,
         impl1_def_id: DefId,
         impl2_def_id: DefId,
-    ) {
+    ) -> Result<(), ErrorGuaranteed> {
         let maybe_overlap = traits::overlapping_impls(
             self.tcx,
             impl1_def_id,
@@ -150,17 +156,19 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
         );
 
         if let Some(overlap) = maybe_overlap {
-            self.check_for_common_items_in_impls(impl1_def_id, impl2_def_id, overlap);
+            self.check_for_common_items_in_impls(impl1_def_id, impl2_def_id, overlap)
+        } else {
+            Ok(())
         }
     }
 
-    fn check_item(&mut self, id: hir::ItemId) {
+    fn check_item(&mut self, id: hir::ItemId) -> Result<(), ErrorGuaranteed> {
         let def_kind = self.tcx.def_kind(id.owner_id);
         if !matches!(def_kind, DefKind::Enum | DefKind::Struct | DefKind::Trait | DefKind::Union) {
-            return;
+            return Ok(());
         }
 
-        let impls = self.tcx.inherent_impls(id.owner_id);
+        let impls = self.tcx.inherent_impls(id.owner_id)?;
 
         let overlap_mode = OverlapMode::get(self.tcx, id.owner_id.to_def_id());
 
@@ -173,17 +181,18 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
         // otherwise switch to an allocating algorithm with
         // faster asymptotic runtime.
         const ALLOCATING_ALGO_THRESHOLD: usize = 500;
+        let mut res = Ok(());
         if impls.len() < ALLOCATING_ALGO_THRESHOLD {
             for (i, &(&impl1_def_id, impl_items1)) in impls_items.iter().enumerate() {
-                self.check_for_duplicate_items_in_impl(impl1_def_id);
+                res = res.and(self.check_for_duplicate_items_in_impl(impl1_def_id));
 
                 for &(&impl2_def_id, impl_items2) in &impls_items[(i + 1)..] {
                     if self.impls_have_common_items(impl_items1, impl_items2) {
-                        self.check_for_overlapping_inherent_impls(
+                        res = res.and(self.check_for_overlapping_inherent_impls(
                             overlap_mode,
                             impl1_def_id,
                             impl2_def_id,
-                        );
+                        ));
                     }
                 }
             }
@@ -315,20 +324,21 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
                 impl_blocks.sort_unstable();
                 for (i, &impl1_items_idx) in impl_blocks.iter().enumerate() {
                     let &(&impl1_def_id, impl_items1) = &impls_items[impl1_items_idx];
-                    self.check_for_duplicate_items_in_impl(impl1_def_id);
+                    res = res.and(self.check_for_duplicate_items_in_impl(impl1_def_id));
 
                     for &impl2_items_idx in impl_blocks[(i + 1)..].iter() {
                         let &(&impl2_def_id, impl_items2) = &impls_items[impl2_items_idx];
                         if self.impls_have_common_items(impl_items1, impl_items2) {
-                            self.check_for_overlapping_inherent_impls(
+                            res = res.and(self.check_for_overlapping_inherent_impls(
                                 overlap_mode,
                                 impl1_def_id,
                                 impl2_def_id,
-                            );
+                            ));
                         }
                     }
                 }
             }
         }
+        res
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
index ade24259ed4..85093bc12b3 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
@@ -5,20 +5,22 @@ use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{self as hir, def, Expr, ImplItem, Item, Node, TraitItem};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
-use rustc_span::{sym, DUMMY_SP};
+use rustc_span::{sym, ErrorGuaranteed, DUMMY_SP};
 
 use crate::errors::{TaitForwardCompat, TypeOf, UnconstrainedOpaqueType};
 
-pub fn test_opaque_hidden_types(tcx: TyCtxt<'_>) {
+pub fn test_opaque_hidden_types(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
+    let mut res = Ok(());
     if tcx.has_attr(CRATE_DEF_ID, sym::rustc_hidden_type_of_opaques) {
         for id in tcx.hir().items() {
             if matches!(tcx.def_kind(id.owner_id), DefKind::OpaqueTy) {
                 let type_of = tcx.type_of(id.owner_id).instantiate_identity();
 
-                tcx.dcx().emit_err(TypeOf { span: tcx.def_span(id.owner_id), type_of });
+                res = Err(tcx.dcx().emit_err(TypeOf { span: tcx.def_span(id.owner_id), type_of }));
             }
         }
     }
+    res
 }
 
 /// Checks "defining uses" of opaque `impl Trait` types to ensure that they meet the restrictions
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index 3f9b1f384d7..2fe08ead72b 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -17,7 +17,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
-use rustc_span::{Span, Symbol};
+use rustc_span::{ErrorGuaranteed, Span, Symbol};
 
 mod min_specialization;
 
@@ -51,24 +51,29 @@ 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: LocalModDefId) {
+fn check_mod_impl_wf(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) -> Result<(), ErrorGuaranteed> {
     let min_specialization = tcx.features().min_specialization;
     let module = tcx.hir_module_items(module_def_id);
+    let mut res = Ok(());
     for id in module.items() {
         if matches!(tcx.def_kind(id.owner_id), DefKind::Impl { .. }) {
-            enforce_impl_params_are_constrained(tcx, id.owner_id.def_id);
+            res = res.and(enforce_impl_params_are_constrained(tcx, id.owner_id.def_id));
             if min_specialization {
-                check_min_specialization(tcx, id.owner_id.def_id);
+                res = res.and(check_min_specialization(tcx, id.owner_id.def_id));
             }
         }
     }
+    res
 }
 
 pub fn provide(providers: &mut Providers) {
     *providers = Providers { check_mod_impl_wf, ..*providers };
 }
 
-fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) {
+fn enforce_impl_params_are_constrained(
+    tcx: TyCtxt<'_>,
+    impl_def_id: LocalDefId,
+) -> Result<(), ErrorGuaranteed> {
     // Every lifetime used in an associated type must be constrained.
     let impl_self_ty = tcx.type_of(impl_def_id).instantiate_identity();
     if impl_self_ty.references_error() {
@@ -80,7 +85,10 @@ fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
                 "potentially unconstrained type parameters weren't evaluated: {impl_self_ty:?}",
             ),
         );
-        return;
+        // This is super fishy, but our current `rustc_hir_analysis::check_crate` pipeline depends on
+        // `type_of` having been called much earlier, and thus this value being read from cache.
+        // Compilation must continue in order for other important diagnostics to keep showing up.
+        return Ok(());
     }
     let impl_generics = tcx.generics_of(impl_def_id);
     let impl_predicates = tcx.predicates_of(impl_def_id);
@@ -113,13 +121,19 @@ fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
         })
         .collect();
 
+    let mut res = Ok(());
     for param in &impl_generics.params {
         match param.kind {
             // Disallow ANY unconstrained type parameters.
             ty::GenericParamDefKind::Type { .. } => {
                 let param_ty = ty::ParamTy::for_def(param);
                 if !input_parameters.contains(&cgp::Parameter::from(param_ty)) {
-                    report_unused_parameter(tcx, tcx.def_span(param.def_id), "type", param_ty.name);
+                    res = Err(report_unused_parameter(
+                        tcx,
+                        tcx.def_span(param.def_id),
+                        "type",
+                        param_ty.name,
+                    ));
                 }
             }
             ty::GenericParamDefKind::Lifetime => {
@@ -127,27 +141,28 @@ fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
                 if lifetimes_in_associated_types.contains(&param_lt) && // (*)
                     !input_parameters.contains(&param_lt)
                 {
-                    report_unused_parameter(
+                    res = Err(report_unused_parameter(
                         tcx,
                         tcx.def_span(param.def_id),
                         "lifetime",
                         param.name,
-                    );
+                    ));
                 }
             }
             ty::GenericParamDefKind::Const { .. } => {
                 let param_ct = ty::ParamConst::for_def(param);
                 if !input_parameters.contains(&cgp::Parameter::from(param_ct)) {
-                    report_unused_parameter(
+                    res = Err(report_unused_parameter(
                         tcx,
                         tcx.def_span(param.def_id),
                         "const",
                         param_ct.name,
-                    );
+                    ));
                 }
             }
         }
     }
+    res
 
     // (*) This is a horrible concession to reality. I think it'd be
     // better to just ban unconstrained lifetimes outright, but in
@@ -169,7 +184,12 @@ fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
     // used elsewhere are not projected back out.
 }
 
-fn report_unused_parameter(tcx: TyCtxt<'_>, span: Span, kind: &str, name: Symbol) {
+fn report_unused_parameter(
+    tcx: TyCtxt<'_>,
+    span: Span,
+    kind: &str,
+    name: Symbol,
+) -> ErrorGuaranteed {
     let mut err = struct_span_code_err!(
         tcx.dcx(),
         span,
@@ -188,5 +208,5 @@ fn report_unused_parameter(tcx: TyCtxt<'_>, span: Span, kind: &str, name: Symbol
             "proving the result of expressions other than the parameter are unique is not supported",
         );
     }
-    err.emit();
+    err.emit()
 }
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index 6964446f9c7..1b6a39d8162 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -82,10 +82,14 @@ use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
 use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _;
 use rustc_trait_selection::traits::{self, translate_args_with_cause, wf, ObligationCtxt};
 
-pub(super) fn check_min_specialization(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) {
+pub(super) fn check_min_specialization(
+    tcx: TyCtxt<'_>,
+    impl_def_id: LocalDefId,
+) -> Result<(), ErrorGuaranteed> {
     if let Some(node) = parent_specialization_node(tcx, impl_def_id) {
-        check_always_applicable(tcx, impl_def_id, node);
+        check_always_applicable(tcx, impl_def_id, node)?;
     }
+    Ok(())
 }
 
 fn parent_specialization_node(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId) -> Option<Node> {
@@ -109,42 +113,58 @@ fn parent_specialization_node(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId) -> Opti
 
 /// Check that `impl1` is a sound specialization
 #[instrument(level = "debug", skip(tcx))]
-fn check_always_applicable(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node) {
+fn check_always_applicable(
+    tcx: TyCtxt<'_>,
+    impl1_def_id: LocalDefId,
+    impl2_node: Node,
+) -> Result<(), ErrorGuaranteed> {
     let span = tcx.def_span(impl1_def_id);
-    check_has_items(tcx, impl1_def_id, impl2_node, span);
-
-    if let Ok((impl1_args, impl2_args)) = get_impl_args(tcx, impl1_def_id, impl2_node) {
-        let impl2_def_id = impl2_node.def_id();
-        debug!(?impl2_def_id, ?impl2_args);
-
-        let parent_args = if impl2_node.is_from_trait() {
-            impl2_args.to_vec()
-        } else {
-            unconstrained_parent_impl_args(tcx, impl2_def_id, impl2_args)
-        };
-
-        check_constness(tcx, impl1_def_id, impl2_node, span);
-        check_static_lifetimes(tcx, &parent_args, span);
-        check_duplicate_params(tcx, impl1_args, &parent_args, span);
-        check_predicates(tcx, impl1_def_id, impl1_args, impl2_node, impl2_args, span);
-    }
+    let mut res = check_has_items(tcx, impl1_def_id, impl2_node, span);
+
+    let (impl1_args, impl2_args) = get_impl_args(tcx, impl1_def_id, impl2_node)?;
+    let impl2_def_id = impl2_node.def_id();
+    debug!(?impl2_def_id, ?impl2_args);
+
+    let parent_args = if impl2_node.is_from_trait() {
+        impl2_args.to_vec()
+    } else {
+        unconstrained_parent_impl_args(tcx, impl2_def_id, impl2_args)
+    };
+
+    res = res.and(check_constness(tcx, impl1_def_id, impl2_node, span));
+    res = res.and(check_static_lifetimes(tcx, &parent_args, span));
+    res = res.and(check_duplicate_params(tcx, impl1_args, &parent_args, span));
+    res = res.and(check_predicates(tcx, impl1_def_id, impl1_args, impl2_node, impl2_args, span));
+
+    res
 }
 
-fn check_has_items(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node, span: Span) {
+fn check_has_items(
+    tcx: TyCtxt<'_>,
+    impl1_def_id: LocalDefId,
+    impl2_node: Node,
+    span: Span,
+) -> Result<(), ErrorGuaranteed> {
     if let Node::Impl(impl2_id) = impl2_node
         && tcx.associated_item_def_ids(impl1_def_id).is_empty()
     {
         let base_impl_span = tcx.def_span(impl2_id);
-        tcx.dcx().emit_err(errors::EmptySpecialization { span, base_impl_span });
+        return Err(tcx.dcx().emit_err(errors::EmptySpecialization { span, base_impl_span }));
     }
+    Ok(())
 }
 
 /// Check that the specializing impl `impl1` is at least as const as the base
 /// impl `impl2`
-fn check_constness(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node, span: Span) {
+fn check_constness(
+    tcx: TyCtxt<'_>,
+    impl1_def_id: LocalDefId,
+    impl2_node: Node,
+    span: Span,
+) -> Result<(), ErrorGuaranteed> {
     if impl2_node.is_from_trait() {
         // This isn't a specialization
-        return;
+        return Ok(());
     }
 
     let impl1_constness = tcx.constness(impl1_def_id.to_def_id());
@@ -152,9 +172,10 @@ fn check_constness(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node,
 
     if let hir::Constness::Const = impl2_constness {
         if let hir::Constness::NotConst = impl1_constness {
-            tcx.dcx().emit_err(errors::ConstSpecialize { span });
+            return Err(tcx.dcx().emit_err(errors::ConstSpecialize { span }));
         }
     }
+    Ok(())
 }
 
 /// Given a specializing impl `impl1`, and the base impl `impl2`, returns two
@@ -290,15 +311,17 @@ fn check_duplicate_params<'tcx>(
     impl1_args: GenericArgsRef<'tcx>,
     parent_args: &Vec<GenericArg<'tcx>>,
     span: Span,
-) {
+) -> Result<(), ErrorGuaranteed> {
     let mut base_params = cgp::parameters_for(parent_args, true);
     base_params.sort_by_key(|param| param.0);
     if let (_, [duplicate, ..]) = base_params.partition_dedup() {
         let param = impl1_args[duplicate.0 as usize];
-        tcx.dcx()
+        return Err(tcx
+            .dcx()
             .struct_span_err(span, format!("specializing impl repeats parameter `{param}`"))
-            .emit();
+            .emit());
     }
+    Ok(())
 }
 
 /// Check that `'static` lifetimes are not introduced by the specializing impl.
@@ -313,10 +336,11 @@ fn check_static_lifetimes<'tcx>(
     tcx: TyCtxt<'tcx>,
     parent_args: &Vec<GenericArg<'tcx>>,
     span: Span,
-) {
+) -> Result<(), ErrorGuaranteed> {
     if tcx.any_free_region_meets(parent_args, |r| r.is_static()) {
-        tcx.dcx().emit_err(errors::StaticSpecialize { span });
+        return Err(tcx.dcx().emit_err(errors::StaticSpecialize { span }));
     }
+    Ok(())
 }
 
 /// Check whether predicates on the specializing impl (`impl1`) are allowed.
@@ -337,7 +361,7 @@ fn check_predicates<'tcx>(
     impl2_node: Node,
     impl2_args: GenericArgsRef<'tcx>,
     span: Span,
-) {
+) -> Result<(), ErrorGuaranteed> {
     let impl1_predicates: Vec<_> = traits::elaborate(
         tcx,
         tcx.predicates_of(impl1_def_id).instantiate(tcx, impl1_args).into_iter(),
@@ -399,14 +423,16 @@ fn check_predicates<'tcx>(
     }
     impl2_predicates.extend(traits::elaborate(tcx, always_applicable_traits));
 
+    let mut res = Ok(());
     for (clause, span) in impl1_predicates {
         if !impl2_predicates
             .iter()
             .any(|pred2| trait_predicates_eq(tcx, clause.as_predicate(), *pred2, span))
         {
-            check_specialization_on(tcx, clause, span)
+            res = res.and(check_specialization_on(tcx, clause, span))
         }
     }
+    res
 }
 
 /// Checks if some predicate on the specializing impl (`predicate1`) is the same
@@ -443,19 +469,26 @@ fn trait_predicates_eq<'tcx>(
 }
 
 #[instrument(level = "debug", skip(tcx))]
-fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, clause: ty::Clause<'tcx>, span: Span) {
+fn check_specialization_on<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    clause: ty::Clause<'tcx>,
+    span: Span,
+) -> Result<(), ErrorGuaranteed> {
     match clause.kind().skip_binder() {
         // Global predicates are either always true or always false, so we
         // are fine to specialize on.
-        _ if clause.is_global() => (),
+        _ if clause.is_global() => Ok(()),
         // We allow specializing on explicitly marked traits with no associated
         // items.
         ty::ClauseKind::Trait(ty::TraitPredicate { trait_ref, polarity: _ }) => {
-            if !matches!(
+            if matches!(
                 trait_specialization_kind(tcx, clause),
                 Some(TraitSpecializationKind::Marker)
             ) {
-                tcx.dcx()
+                Ok(())
+            } else {
+                Err(tcx
+                    .dcx()
                     .struct_span_err(
                         span,
                         format!(
@@ -463,17 +496,16 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, clause: ty::Clause<'tcx>, sp
                             tcx.def_path_str(trait_ref.def_id),
                         ),
                     )
-                    .emit();
+                    .emit())
             }
         }
-        ty::ClauseKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
-            tcx.dcx()
-                .struct_span_err(
-                    span,
-                    format!("cannot specialize on associated type `{projection_ty} == {term}`",),
-                )
-                .emit();
-        }
+        ty::ClauseKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => Err(tcx
+            .dcx()
+            .struct_span_err(
+                span,
+                format!("cannot specialize on associated type `{projection_ty} == {term}`",),
+            )
+            .emit()),
         ty::ClauseKind::ConstArgHasType(..) => {
             // FIXME(min_specialization), FIXME(const_generics):
             // It probably isn't right to allow _every_ `ConstArgHasType` but I am somewhat unsure
@@ -483,12 +515,12 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, clause: ty::Clause<'tcx>, sp
             // While we do not support constructs like `<T, const N: T>` there is probably no risk of
             // soundness bugs, but when we support generic const parameter types this will need to be
             // revisited.
+            Ok(())
         }
-        _ => {
-            tcx.dcx()
-                .struct_span_err(span, format!("cannot specialize on predicate `{clause}`"))
-                .emit();
-        }
+        _ => Err(tcx
+            .dcx()
+            .struct_span_err(span, format!("cannot specialize on predicate `{clause}`"))
+            .emit()),
     }
 }
 
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index f5abb7261c0..08956d222d2 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -166,33 +166,29 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
         tcx.hir().for_each_module(|module| tcx.ensure().collect_mod_item_types(module))
     });
 
-    // FIXME(matthewjasper) We shouldn't need to use `track_errors` anywhere in this function
-    // or the compiler in general.
     if tcx.features().rustc_attrs {
-        tcx.sess.track_errors(|| {
-            tcx.sess.time("outlives_testing", || outlives::test::test_inferred_outlives(tcx));
-        })?;
+        tcx.sess.time("outlives_testing", || outlives::test::test_inferred_outlives(tcx))?;
     }
 
-    tcx.sess.track_errors(|| {
-        tcx.sess.time("coherence_checking", || {
-            // Check impls constrain their parameters
-            tcx.hir().for_each_module(|module| tcx.ensure().check_mod_impl_wf(module));
+    tcx.sess.time("coherence_checking", || {
+        // Check impls constrain their parameters
+        let res =
+            tcx.hir().try_par_for_each_module(|module| tcx.ensure().check_mod_impl_wf(module));
 
+        // FIXME(matthewjasper) We shouldn't need to use `track_errors` anywhere in this function
+        // or the compiler in general.
+        res.and(tcx.sess.track_errors(|| {
             for &trait_def_id in tcx.all_local_trait_impls(()).keys() {
                 tcx.ensure().coherent_trait(trait_def_id);
             }
-
-            // these queries are executed for side-effects (error reporting):
-            tcx.ensure().crate_inherent_impls(());
-            tcx.ensure().crate_inherent_impls_overlap_check(());
-        });
+        }))
+        // these queries are executed for side-effects (error reporting):
+        .and(tcx.ensure().crate_inherent_impls(()))
+        .and(tcx.ensure().crate_inherent_impls_overlap_check(()))
     })?;
 
     if tcx.features().rustc_attrs {
-        tcx.sess.track_errors(|| {
-            tcx.sess.time("variance_testing", || variance::test::test_variance(tcx));
-        })?;
+        tcx.sess.time("variance_testing", || variance::test::test_variance(tcx))?;
     }
 
     tcx.sess.time("wf_checking", || {
@@ -200,7 +196,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
     })?;
 
     if tcx.features().rustc_attrs {
-        tcx.sess.track_errors(|| collect::test_opaque_hidden_types(tcx))?;
+        collect::test_opaque_hidden_types(tcx)?;
     }
 
     // Freeze definitions as we don't add new ones at this point. This improves performance by
diff --git a/compiler/rustc_hir_analysis/src/outlives/test.rs b/compiler/rustc_hir_analysis/src/outlives/test.rs
index dea3f1a9930..60cd8c39fa0 100644
--- a/compiler/rustc_hir_analysis/src/outlives/test.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/test.rs
@@ -1,7 +1,8 @@
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_span::symbol::sym;
+use rustc_span::{symbol::sym, ErrorGuaranteed};
 
-pub fn test_inferred_outlives(tcx: TyCtxt<'_>) {
+pub fn test_inferred_outlives(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
+    let mut res = Ok(());
     for id in tcx.hir().items() {
         // For unit testing: check for a special "rustc_outlives"
         // attribute and report an error with various results if found.
@@ -22,7 +23,8 @@ pub fn test_inferred_outlives(tcx: TyCtxt<'_>) {
             for p in pred {
                 err.note(p);
             }
-            err.emit();
+            res = Err(err.emit());
         }
     }
+    res
 }
diff --git a/compiler/rustc_hir_analysis/src/variance/test.rs b/compiler/rustc_hir_analysis/src/variance/test.rs
index 5264d5aa26f..c211e1af046 100644
--- a/compiler/rustc_hir_analysis/src/variance/test.rs
+++ b/compiler/rustc_hir_analysis/src/variance/test.rs
@@ -2,19 +2,21 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::sym;
+use rustc_span::ErrorGuaranteed;
 
 use crate::errors;
 
-pub fn test_variance(tcx: TyCtxt<'_>) {
+pub fn test_variance(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
+    let mut res = Ok(());
     if tcx.has_attr(CRATE_DEF_ID, sym::rustc_variance_of_opaques) {
         for id in tcx.hir().items() {
             if matches!(tcx.def_kind(id.owner_id), DefKind::OpaqueTy) {
                 let variances_of = tcx.variances_of(id.owner_id);
 
-                tcx.dcx().emit_err(errors::VariancesOf {
+                res = Err(tcx.dcx().emit_err(errors::VariancesOf {
                     span: tcx.def_span(id.owner_id),
                     variances_of: format!("{variances_of:?}"),
-                });
+                }));
             }
         }
     }
@@ -25,10 +27,11 @@ pub fn test_variance(tcx: TyCtxt<'_>) {
         if tcx.has_attr(id.owner_id, sym::rustc_variance) {
             let variances_of = tcx.variances_of(id.owner_id);
 
-            tcx.dcx().emit_err(errors::VariancesOf {
+            res = Err(tcx.dcx().emit_err(errors::VariancesOf {
                 span: tcx.def_span(id.owner_id),
                 variances_of: format!("{variances_of:?}"),
-            });
+            }));
         }
     }
+    res
 }
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index d5a39cd8405..8a035d0577f 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -71,7 +71,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let parent_args =
             GenericArgs::identity_for_item(tcx, tcx.typeck_root_def_id(expr_def_id.to_def_id()));
 
-        let tupled_upvars_ty = self.next_root_ty_var(TypeVariableOrigin {
+        let tupled_upvars_ty = self.next_ty_var(TypeVariableOrigin {
             kind: TypeVariableOriginKind::ClosureSynthetic,
             span: expr_span,
         });
@@ -101,7 +101,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // Create a type variable (for now) to represent the closure kind.
                     // It will be unified during the upvar inference phase (`upvar.rs`)
-                    None => self.next_root_ty_var(TypeVariableOrigin {
+                    None => self.next_ty_var(TypeVariableOrigin {
                         // FIXME(eddyb) distinguish closure kind inference variables from the rest.
                         kind: TypeVariableOriginKind::ClosureSynthetic,
                         span: expr_span,
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 0576ab3b80c..4b1ad28f094 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -2102,7 +2102,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let mut items = self
                 .tcx
                 .inherent_impls(def_id)
-                .iter()
+                .into_iter()
+                .flatten()
                 .flat_map(|i| self.tcx.associated_items(i).in_definition_order())
                 // Only assoc fn with no receivers.
                 .filter(|item| {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index fde3d41faec..f3d70867e37 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -190,10 +190,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub fn errors_reported_since_creation(&self) -> bool {
         self.dcx().err_count() > self.err_count_on_creation
     }
-
-    pub fn next_root_ty_var(&self, origin: TypeVariableOrigin) -> Ty<'tcx> {
-        Ty::new_var(self.tcx, self.next_ty_var_id_in_universe(origin, ty::UniverseIndex::ROOT))
-    }
 }
 
 impl<'a, 'tcx> Deref for FnCtxt<'a, 'tcx> {
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 10c31d8c641..4dc802008d0 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -711,14 +711,14 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let Some(simp) = simplify_type(self.tcx, self_ty, TreatParams::AsCandidateKey) else {
             bug!("unexpected incoherent type: {:?}", self_ty)
         };
-        for &impl_def_id in self.tcx.incoherent_impls(simp) {
+        for &impl_def_id in self.tcx.incoherent_impls(simp).into_iter().flatten() {
             self.assemble_inherent_impl_probe(impl_def_id);
         }
     }
 
     fn assemble_inherent_impl_candidates_for_type(&mut self, def_id: DefId) {
-        let impl_def_ids = self.tcx.at(self.span).inherent_impls(def_id);
-        for &impl_def_id in impl_def_ids.iter() {
+        let impl_def_ids = self.tcx.at(self.span).inherent_impls(def_id).into_iter().flatten();
+        for &impl_def_id in impl_def_ids {
             self.assemble_inherent_impl_probe(impl_def_id);
         }
     }
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 3bf1e1312b3..0b8a25eedaf 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -359,7 +359,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     if let ty::Adt(adt_def, _) = ty.kind() {
                         self.tcx
                             .inherent_impls(adt_def.did())
-                            .iter()
+                            .into_iter()
+                            .flatten()
                             .any(|def_id| self.associated_value(*def_id, item_name).is_some())
                     } else {
                         false
@@ -1048,7 +1049,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let mut inherent_impls_candidate = self
                         .tcx
                         .inherent_impls(adt.did())
-                        .iter()
+                        .into_iter()
+                        .flatten()
                         .copied()
                         .filter(|def_id| {
                             if let Some(assoc) = self.associated_value(*def_id, item_name) {
@@ -1103,7 +1105,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             "the {item_kind} was found for\n{type_candidates}{additional_types}"
                         ));
                     } else {
-                        'outer: for inherent_impl_did in self.tcx.inherent_impls(adt.did()) {
+                        'outer: for inherent_impl_did in
+                            self.tcx.inherent_impls(adt.did()).into_iter().flatten()
+                        {
                             for inherent_method in
                                 self.tcx.associated_items(inherent_impl_did).in_definition_order()
                             {
@@ -1457,9 +1461,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let ty::Adt(adt_def, _) = rcvr_ty.kind() else {
             return;
         };
-        let mut items = self
-            .tcx
-            .inherent_impls(adt_def.did())
+        // FIXME(oli-obk): try out bubbling this error up one level and cancelling the other error in that case.
+        let Ok(impls) = self.tcx.inherent_impls(adt_def.did()) else { return };
+        let mut items = impls
             .iter()
             .flat_map(|i| self.tcx.associated_items(i).in_definition_order())
             // Only assoc fn with no receivers.
@@ -1823,7 +1827,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             simplify_type(tcx, ty, TreatParams::AsCandidateKey)
                 .and_then(|simp| {
                     tcx.incoherent_impls(simp)
-                        .iter()
+                        .into_iter()
+                        .flatten()
                         .find_map(|&id| self.associated_value(id, item_name))
                 })
                 .is_some()
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 588139a303c..555c822ad6d 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -4,10 +4,10 @@ use rustc_data_structures::profiling::TimePassesFormat;
 use rustc_errors::{emitter::HumanReadableErrorType, registry, ColorConfig};
 use rustc_session::config::{
     build_configuration, build_session_options, rustc_optgroups, BranchProtection, CFGuard, Cfg,
-    DebugInfo, DumpMonoStatsFormat, ErrorOutputType, ExternEntry, ExternLocation, Externs,
-    FunctionReturn, InliningThreshold, Input, InstrumentCoverage, InstrumentXRay,
-    LinkSelfContained, LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig, OomStrategy,
-    Options, OutFileName, OutputType, OutputTypes, PAuthKey, PacRet, Passes, Polonius,
+    CollapseMacroDebuginfo, DebugInfo, DumpMonoStatsFormat, ErrorOutputType, ExternEntry,
+    ExternLocation, Externs, FunctionReturn, InliningThreshold, Input, InstrumentCoverage,
+    InstrumentXRay, LinkSelfContained, LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig,
+    OomStrategy, Options, OutFileName, OutputType, OutputTypes, PAuthKey, PacRet, Passes, Polonius,
     ProcMacroExecutionStrategy, Strip, SwitchWithOptPath, SymbolManglingVersion, WasiExecModel,
 };
 use rustc_session::lint::Level;
@@ -742,6 +742,7 @@ fn test_unstable_options_tracking_hash() {
         })
     );
     tracked!(codegen_backend, Some("abc".to_string()));
+    tracked!(collapse_macro_debuginfo, CollapseMacroDebuginfo::Yes);
     tracked!(crate_attr, vec!["abc".to_string()]);
     tracked!(cross_crate_inline_threshold, InliningThreshold::Always);
     tracked!(debug_info_for_profiling, true);
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 49e849964be..20e3ae3ba94 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -1027,6 +1027,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             self.root.edition,
             Symbol::intern(name),
             &attrs,
+            false,
         )
     }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 912c2f36eb3..c3d6c21c402 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -283,7 +283,7 @@ provide! { tcx, def_id, other, cdata,
         tcx.arena.alloc_from_iter(cdata.get_associated_item_or_field_def_ids(def_id.index))
     }
     associated_item => { cdata.get_associated_item(def_id.index, tcx.sess) }
-    inherent_impls => { cdata.get_inherent_implementations_for_type(tcx, def_id.index) }
+    inherent_impls => { Ok(cdata.get_inherent_implementations_for_type(tcx, def_id.index)) }
     item_attrs => { tcx.arena.alloc_from_iter(cdata.get_item_attrs(def_id.index, tcx.sess)) }
     is_mir_available => { cdata.is_item_mir_available(def_id.index) }
     is_ctfe_mir_available => { cdata.is_ctfe_mir_available(def_id.index) }
@@ -328,7 +328,7 @@ provide! { tcx, def_id, other, cdata,
     traits => { tcx.arena.alloc_from_iter(cdata.get_traits()) }
     trait_impls_in_crate => { tcx.arena.alloc_from_iter(cdata.get_trait_impls()) }
     implementations_of_trait => { cdata.get_implementations_of_trait(tcx, other) }
-    crate_incoherent_impls => { cdata.get_incoherent_impls(tcx, other) }
+    crate_incoherent_impls => { Ok(cdata.get_incoherent_impls(tcx, other)) }
 
     dep_kind => { cdata.dep_kind }
     module_children => {
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index a458b528a97..2d4e49e27d9 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1485,7 +1485,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
 
         let inherent_impls = tcx.with_stable_hashing_context(|hcx| {
-            tcx.crate_inherent_impls(()).inherent_impls.to_sorted(&hcx, true)
+            tcx.crate_inherent_impls(()).unwrap().inherent_impls.to_sorted(&hcx, true)
         });
         for (def_id, impls) in inherent_impls {
             record_defaulted_array!(self.tables.inherent_impls[def_id.to_def_id()] <- impls.iter().map(|def_id| {
@@ -2028,7 +2028,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         empty_proc_macro!(self);
         let tcx = self.tcx;
         let all_impls = tcx.with_stable_hashing_context(|hcx| {
-            tcx.crate_inherent_impls(()).incoherent_impls.to_sorted(&hcx, true)
+            tcx.crate_inherent_impls(()).unwrap().incoherent_impls.to_sorted(&hcx, true)
         });
 
         let all_impls: Vec<_> = all_impls
diff --git a/compiler/rustc_middle/src/arena.rs b/compiler/rustc_middle/src/arena.rs
index 8a4fd01437f..e745913fabc 100644
--- a/compiler/rustc_middle/src/arena.rs
+++ b/compiler/rustc_middle/src/arena.rs
@@ -114,6 +114,7 @@ macro_rules! arena_types {
             [] mod_child: rustc_middle::metadata::ModChild,
             [] features: rustc_feature::Features,
             [decode] specialization_graph: rustc_middle::traits::specialization_graph::Graph,
+            [] crate_inherent_impls: rustc_middle::ty::CrateInherentImpls,
         ]);
     )
 }
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 2cf6410990e..3b60eba2dfe 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -1098,10 +1098,10 @@ fn pre_fmt_projection(projection: &[PlaceElem<'_>], fmt: &mut Formatter<'_>) ->
             | ProjectionElem::Subtype(_)
             | ProjectionElem::Downcast(_, _)
             | ProjectionElem::Field(_, _) => {
-                write!(fmt, "(").unwrap();
+                write!(fmt, "(")?;
             }
             ProjectionElem::Deref => {
-                write!(fmt, "(*").unwrap();
+                write!(fmt, "(*")?;
             }
             ProjectionElem::Index(_)
             | ProjectionElem::ConstantIndex { .. }
diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs
index 9742ff42419..778b4308d2e 100644
--- a/compiler/rustc_middle/src/query/erase.rs
+++ b/compiler/rustc_middle/src/query/erase.rs
@@ -82,6 +82,10 @@ impl<T> EraseType for Result<&'_ T, rustc_errors::ErrorGuaranteed> {
     type Result = [u8; size_of::<Result<&'static (), rustc_errors::ErrorGuaranteed>>()];
 }
 
+impl<T> EraseType for Result<&'_ [T], rustc_errors::ErrorGuaranteed> {
+    type Result = [u8; size_of::<Result<&'static [()], rustc_errors::ErrorGuaranteed>>()];
+}
+
 impl<T> EraseType for Result<&'_ T, traits::CodegenObligationError> {
     type Result = [u8; size_of::<Result<&'static (), traits::CodegenObligationError>>()];
 }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 3854b658669..a9dc7f5d11a 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -851,13 +851,13 @@ rustc_queries! {
     /// Maps a `DefId` of a type to a list of its inherent impls.
     /// Contains implementations of methods that are inherent to a type.
     /// Methods in these implementations don't need to be exported.
-    query inherent_impls(key: DefId) -> &'tcx [DefId] {
+    query inherent_impls(key: DefId) -> Result<&'tcx [DefId], ErrorGuaranteed> {
         desc { |tcx| "collecting inherent impls for `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }
         separate_provide_extern
     }
 
-    query incoherent_impls(key: SimplifiedType) -> &'tcx [DefId] {
+    query incoherent_impls(key: SimplifiedType) -> Result<&'tcx [DefId], ErrorGuaranteed> {
         desc { |tcx| "collecting all inherent impls for `{:?}`", key }
     }
 
@@ -953,8 +953,9 @@ rustc_queries! {
         desc { |tcx| "checking deathness of variables in {}", describe_as_module(key, tcx) }
     }
 
-    query check_mod_impl_wf(key: LocalModDefId) -> () {
+    query check_mod_impl_wf(key: LocalModDefId) -> Result<(), ErrorGuaranteed> {
         desc { |tcx| "checking that impls are well-formed in {}", describe_as_module(key, tcx) }
+        ensure_forwards_result_if_red
     }
 
     query check_mod_type_wf(key: LocalModDefId) -> Result<(), ErrorGuaranteed> {
@@ -1003,15 +1004,16 @@ rustc_queries! {
 
     /// Gets a complete map from all types to their inherent impls.
     /// Not meant to be used directly outside of coherence.
-    query crate_inherent_impls(k: ()) -> &'tcx CrateInherentImpls {
-        arena_cache
+    query crate_inherent_impls(k: ()) -> Result<&'tcx CrateInherentImpls, ErrorGuaranteed> {
         desc { "finding all inherent impls defined in crate" }
+        ensure_forwards_result_if_red
     }
 
     /// Checks all types in the crate for overlap in their inherent impls. Reports errors.
     /// Not meant to be used directly outside of coherence.
-    query crate_inherent_impls_overlap_check(_: ()) -> () {
+    query crate_inherent_impls_overlap_check(_: ()) -> Result<(), ErrorGuaranteed> {
         desc { "check for overlap between inherent impls defined in this crate" }
+        ensure_forwards_result_if_red
     }
 
     /// Checks whether all impls in the crate pass the overlap check, returning
@@ -1637,7 +1639,7 @@ rustc_queries! {
     ///
     /// Do not call this directly, but instead use the `incoherent_impls` query.
     /// This query is only used to get the data necessary for that query.
-    query crate_incoherent_impls(key: (CrateNum, SimplifiedType)) -> &'tcx [DefId] {
+    query crate_incoherent_impls(key: (CrateNum, SimplifiedType)) -> Result<&'tcx [DefId], ErrorGuaranteed> {
         desc { |tcx| "collecting all impls for a type in a crate" }
         separate_provide_extern
     }
diff --git a/compiler/rustc_middle/src/query/plumbing.rs b/compiler/rustc_middle/src/query/plumbing.rs
index a41d4f1ad58..8d88488e167 100644
--- a/compiler/rustc_middle/src/query/plumbing.rs
+++ b/compiler/rustc_middle/src/query/plumbing.rs
@@ -174,7 +174,7 @@ pub fn query_ensure<'tcx, Cache>(
 }
 
 #[inline]
-pub fn query_ensure_error_guaranteed<'tcx, Cache>(
+pub fn query_ensure_error_guaranteed<'tcx, Cache, T>(
     tcx: TyCtxt<'tcx>,
     execute_query: fn(TyCtxt<'tcx>, Span, Cache::Key, QueryMode) -> Option<Cache::Value>,
     query_cache: &Cache,
@@ -182,14 +182,16 @@ pub fn query_ensure_error_guaranteed<'tcx, Cache>(
     check_cache: bool,
 ) -> Result<(), ErrorGuaranteed>
 where
-    Cache: QueryCache<Value = super::erase::Erase<Result<(), ErrorGuaranteed>>>,
+    Cache: QueryCache<Value = super::erase::Erase<Result<T, ErrorGuaranteed>>>,
+    Result<T, ErrorGuaranteed>: EraseType,
 {
     let key = key.into_query_param();
     if let Some(res) = try_get_cached(tcx, query_cache, &key) {
-        super::erase::restore(res)
+        super::erase::restore(res).map(drop)
     } else {
         execute_query(tcx, DUMMY_SP, key, QueryMode::Ensure { check_cache })
             .map(super::erase::restore)
+            .map(|res| res.map(drop))
             // Either we actually executed the query, which means we got a full `Result`,
             // or we can just assume the query succeeded, because it was green in the
             // incremental cache. If it is green, that means that the previous compilation
@@ -205,7 +207,7 @@ macro_rules! query_ensure {
         query_ensure($($args)*)
     };
     ([(ensure_forwards_result_if_red) $($rest:tt)*]$($args:tt)*) => {
-        query_ensure_error_guaranteed($($args)*)
+        query_ensure_error_guaranteed($($args)*).map(|_| ())
     };
     ([$other:tt $($modifiers:tt)*]$($args:tt)*) => {
         query_ensure!([$($modifiers)*]$($args)*)
@@ -667,5 +669,7 @@ mod sealed {
 
 pub use sealed::IntoQueryParam;
 
+use super::erase::EraseType;
+
 #[derive(Copy, Clone, Debug, HashStable)]
 pub struct CyclePlaceholder(pub ErrorGuaranteed);
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index ad9296a4cc8..a5d9e0fcf44 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -2535,8 +2535,7 @@ impl<'tcx> TyCtxt<'tcx> {
         if self.sess.opts.unstable_opts.debug_macros || !span.from_expansion() {
             return span;
         }
-        let collapse_debuginfo_enabled = self.features().collapse_debuginfo;
-        hygiene::walk_chain_collapsed(span, upto, collapse_debuginfo_enabled)
+        hygiene::walk_chain_collapsed(span, upto, self.features().collapse_debuginfo)
     }
 
     #[inline]
diff --git a/compiler/rustc_middle/src/ty/trait_def.rs b/compiler/rustc_middle/src/ty/trait_def.rs
index 227a0753d04..d85b541d363 100644
--- a/compiler/rustc_middle/src/ty/trait_def.rs
+++ b/compiler/rustc_middle/src/ty/trait_def.rs
@@ -254,16 +254,28 @@ pub(super) fn trait_impls_of_provider(tcx: TyCtxt<'_>, trait_id: DefId) -> Trait
 }
 
 /// Query provider for `incoherent_impls`.
-pub(super) fn incoherent_impls_provider(tcx: TyCtxt<'_>, simp: SimplifiedType) -> &[DefId] {
+pub(super) fn incoherent_impls_provider(
+    tcx: TyCtxt<'_>,
+    simp: SimplifiedType,
+) -> Result<&[DefId], ErrorGuaranteed> {
     let mut impls = Vec::new();
 
+    let mut res = Ok(());
     for cnum in iter::once(LOCAL_CRATE).chain(tcx.crates(()).iter().copied()) {
-        for &impl_def_id in tcx.crate_incoherent_impls((cnum, simp)) {
+        let incoherent_impls = match tcx.crate_incoherent_impls((cnum, simp)) {
+            Ok(impls) => impls,
+            Err(e) => {
+                res = Err(e);
+                continue;
+            }
+        };
+        for &impl_def_id in incoherent_impls {
             impls.push(impl_def_id)
         }
     }
 
     debug!(?impls);
+    res?;
 
-    tcx.arena.alloc_slice(&impls)
+    Ok(tcx.arena.alloc_slice(&impls))
 }
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 070580860c1..20e70f87b75 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1433,7 +1433,7 @@ fn collect_alloc<'tcx>(tcx: TyCtxt<'tcx>, alloc_id: AllocId, output: &mut MonoIt
 }
 
 fn assoc_fn_of_type<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, fn_ident: Ident) -> Option<DefId> {
-    for impl_def_id in tcx.inherent_impls(def_id) {
+    for impl_def_id in tcx.inherent_impls(def_id).ok()? {
         if let Some(new) = tcx.associated_items(impl_def_id).find_by_name_and_kind(
             tcx,
             fn_ident,
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 58ff4d8c793..5a95f2083f6 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1745,12 +1745,10 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             // Doing analysis on local `DefId`s would cause infinite recursion.
             return;
         }
+        let Ok(impls) = self.r.tcx.inherent_impls(def_id) else { return };
         // Look at all the associated functions without receivers in the type's
         // inherent impls to look for builders that return `Self`
-        let mut items = self
-            .r
-            .tcx
-            .inherent_impls(def_id)
+        let mut items = impls
             .iter()
             .flat_map(|i| self.r.tcx.associated_items(i).in_definition_order())
             // Only assoc fn with no receivers.
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index ac15c3b407b..e751ff13a34 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -3190,12 +3190,12 @@ pub enum WasiExecModel {
 /// how the hash should be calculated when adding a new command-line argument.
 pub(crate) mod dep_tracking {
     use super::{
-        BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, DebugInfoCompression,
-        ErrorOutputType, FunctionReturn, InliningThreshold, InstrumentCoverage, InstrumentXRay,
-        LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig, OomStrategy, OptLevel,
-        OutFileName, OutputType, OutputTypes, Polonius, RemapPathScopeComponents, ResolveDocLinks,
-        SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath, SymbolManglingVersion,
-        WasiExecModel,
+        BranchProtection, CFGuard, CFProtection, CollapseMacroDebuginfo, CrateType, DebugInfo,
+        DebugInfoCompression, ErrorOutputType, FunctionReturn, InliningThreshold,
+        InstrumentCoverage, InstrumentXRay, LinkerPluginLto, LocationDetail, LtoCli,
+        NextSolverConfig, OomStrategy, OptLevel, OutFileName, OutputType, OutputTypes, Polonius,
+        RemapPathScopeComponents, ResolveDocLinks, SourceFileHashAlgorithm, SplitDwarfKind,
+        SwitchWithOptPath, SymbolManglingVersion, WasiExecModel,
     };
     use crate::lint;
     use crate::utils::NativeLib;
@@ -3274,6 +3274,7 @@ pub(crate) mod dep_tracking {
         LtoCli,
         DebugInfo,
         DebugInfoCompression,
+        CollapseMacroDebuginfo,
         UnstableFeatures,
         NativeLib,
         SanitizerSet,
@@ -3437,6 +3438,25 @@ pub enum ProcMacroExecutionStrategy {
     CrossThread,
 }
 
+/// How to perform collapse macros debug info
+/// if-ext - if macro from different crate (related to callsite code)
+/// | cmd \ attr    | no  | (unspecified) | external | yes |
+/// | no            | no  | no            | no       | no  |
+/// | (unspecified) | no  | no            | if-ext   | yes |
+/// | external      | no  | if-ext        | if-ext   | yes |
+/// | yes           | yes | yes           | yes      | yes |
+#[derive(Clone, Copy, PartialEq, Hash, Debug)]
+pub enum CollapseMacroDebuginfo {
+    /// Don't collapse debuginfo for the macro
+    No = 0,
+    /// Unspecified value
+    Unspecified = 1,
+    /// Collapse debuginfo if the macro comes from a different crate
+    External = 2,
+    /// Collapse debuginfo for the macro
+    Yes = 3,
+}
+
 /// Which format to use for `-Z dump-mono-stats`
 #[derive(Clone, Copy, PartialEq, Hash, Debug)]
 pub enum DumpMonoStatsFormat {
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 5bc88ae6ed1..1337ade62c0 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -388,6 +388,7 @@ mod desc {
     pub const parse_cfprotection: &str = "`none`|`no`|`n` (default), `branch`, `return`, or `full`|`yes`|`y` (equivalent to `branch` and `return`)";
     pub const parse_debuginfo: &str = "either an integer (0, 1, 2), `none`, `line-directives-only`, `line-tables-only`, `limited`, or `full`";
     pub const parse_debuginfo_compression: &str = "one of `none`, `zlib`, or `zstd`";
+    pub const parse_collapse_macro_debuginfo: &str = "one of `no`, `external`, or `yes`";
     pub const parse_strip: &str = "either `none`, `debuginfo`, or `symbols`";
     pub const parse_linker_flavor: &str = ::rustc_target::spec::LinkerFlavorCli::one_of();
     pub const parse_optimization_fuel: &str = "crate=integer";
@@ -1302,6 +1303,19 @@ mod parse {
         true
     }
 
+    pub(crate) fn parse_collapse_macro_debuginfo(
+        slot: &mut CollapseMacroDebuginfo,
+        v: Option<&str>,
+    ) -> bool {
+        *slot = match v {
+            Some("no") => CollapseMacroDebuginfo::No,
+            Some("external") => CollapseMacroDebuginfo::External,
+            Some("yes") => CollapseMacroDebuginfo::Yes,
+            _ => return false,
+        };
+        true
+    }
+
     pub(crate) fn parse_proc_macro_execution_strategy(
         slot: &mut ProcMacroExecutionStrategy,
         v: Option<&str>,
@@ -1534,6 +1548,9 @@ options! {
         "instrument control-flow architecture protection"),
     codegen_backend: Option<String> = (None, parse_opt_string, [TRACKED],
         "the backend to use"),
+    collapse_macro_debuginfo: CollapseMacroDebuginfo = (CollapseMacroDebuginfo::Unspecified,
+        parse_collapse_macro_debuginfo, [TRACKED],
+        "set option to collapse debuginfo for macros"),
     combine_cgu: bool = (false, parse_bool, [TRACKED],
         "combine CGUs into a single one"),
     crate_attr: Vec<String> = (Vec::new(), parse_string_push, [TRACKED],
diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
index 5be794f3e17..3d26efec5a6 100644
--- a/compiler/rustc_span/src/hygiene.rs
+++ b/compiler/rustc_span/src/hygiene.rs
@@ -464,12 +464,15 @@ impl HygieneData {
         &self,
         mut span: Span,
         to: Span,
-        collapse_debuginfo_enabled: bool,
+        collapse_debuginfo_feature_enabled: bool,
     ) -> Span {
         let orig_span = span;
         let mut ret_span = span;
 
-        debug!("walk_chain_collapsed({:?}, {:?})", span, to);
+        debug!(
+            "walk_chain_collapsed({:?}, {:?}), feature_enable={}",
+            span, to, collapse_debuginfo_feature_enabled,
+        );
         debug!("walk_chain_collapsed: span ctxt = {:?}", span.ctxt());
         while !span.eq_ctxt(to) && span.from_expansion() {
             let outer_expn = self.outer_expn(span.ctxt());
@@ -477,7 +480,7 @@ impl HygieneData {
             let expn_data = self.expn_data(outer_expn);
             debug!("walk_chain_collapsed({:?}): expn_data={:?}", span, expn_data);
             span = expn_data.call_site;
-            if !collapse_debuginfo_enabled || expn_data.collapse_debuginfo {
+            if !collapse_debuginfo_feature_enabled || expn_data.collapse_debuginfo {
                 ret_span = span;
             }
         }
@@ -601,8 +604,14 @@ pub fn walk_chain(span: Span, to: SyntaxContext) -> Span {
     HygieneData::with(|data| data.walk_chain(span, to))
 }
 
-pub fn walk_chain_collapsed(span: Span, to: Span, collapse_debuginfo_enabled: bool) -> Span {
-    HygieneData::with(|hdata| hdata.walk_chain_collapsed(span, to, collapse_debuginfo_enabled))
+pub fn walk_chain_collapsed(
+    span: Span,
+    to: Span,
+    collapse_debuginfo_feature_enabled: bool,
+) -> Span {
+    HygieneData::with(|hdata| {
+        hdata.walk_chain_collapsed(span, to, collapse_debuginfo_feature_enabled)
+    })
 }
 
 pub fn update_dollar_crate_names(mut get_name: impl FnMut(SyntaxContext) -> Symbol) {
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 72b62a795fc..44795022cba 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -749,6 +749,7 @@ symbols! {
         extern_in_paths,
         extern_prelude,
         extern_types,
+        external,
         external_doc,
         f,
         f16c_target_feature,
@@ -1811,6 +1812,7 @@ symbols! {
         xmm_reg,
         yeet_desugar_details,
         yeet_expr,
+        yes,
         yield_expr,
         ymm_reg,
         zmm_reg,
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 6f3be1f6e93..28d96cb1cfe 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -924,14 +924,17 @@ class RustBuild(object):
         # default toolchain is not nightly.
         #
         # But that setting has the collateral effect of rust-analyzer also
-        # passing RUSTC_BOOTSTRAP=1 to all x.py invocations too (the various
-        # overrideCommand). For compiling bootstrap, that is unwanted and can
-        # cause spurious rebuilding of bootstrap when rust-analyzer x.py
-        # invocations are interleaved with handwritten ones on the command line.
-        env.pop("RUSTC_BOOTSTRAP", None)
-
-        # preserve existing RUSTFLAGS
-        env.setdefault("RUSTFLAGS", "")
+        # passing RUSTC_BOOTSTRAP=1 to all x.py invocations too (the various overrideCommand).
+        # For compiling bootstrap that can cause spurious rebuilding of bootstrap when
+        # rust-analyzer x.py invocations are interleaved with handwritten ones on the
+        # command line.
+        #
+        # Set RUSTC_BOOTSTRAP=1 consistently.
+        env["RUSTC_BOOTSTRAP"] = "1"
+
+        default_rustflags = "" if env.get("RUSTFLAGS_BOOTSTRAP", "") else "-Zallow-features="
+
+        env.setdefault("RUSTFLAGS", default_rustflags)
 
         target_features = []
         if self.get_toml("crt-static", build_section) == "true":
diff --git a/src/bootstrap/src/core/builder.rs b/src/bootstrap/src/core/builder.rs
index 4e20babc55a..3770d0687b2 100644
--- a/src/bootstrap/src/core/builder.rs
+++ b/src/bootstrap/src/core/builder.rs
@@ -1799,15 +1799,20 @@ impl<'a> Builder<'a> {
         }
 
         if self.config.rust_remap_debuginfo {
-            // FIXME: handle vendored sources
-            let registry_src = t!(home::cargo_home()).join("registry").join("src");
             let mut env_var = OsString::new();
-            for entry in t!(std::fs::read_dir(registry_src)) {
-                if !env_var.is_empty() {
-                    env_var.push("\t");
-                }
-                env_var.push(t!(entry).path());
+            if self.config.vendor {
+                let vendor = self.build.src.join("vendor");
+                env_var.push(vendor);
                 env_var.push("=/rust/deps");
+            } else {
+                let registry_src = t!(home::cargo_home()).join("registry").join("src");
+                for entry in t!(std::fs::read_dir(registry_src)) {
+                    if !env_var.is_empty() {
+                        env_var.push("\t");
+                    }
+                    env_var.push(t!(entry).path());
+                    env_var.push("=/rust/deps");
+                }
             }
             cargo.env("RUSTC_CARGO_REGISTRY_SRC_TO_REMAP", env_var);
         }
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 014bcb1a881..aab974ad79e 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -312,7 +312,7 @@ pub(crate) fn build_impls(
     let tcx = cx.tcx;
 
     // for each implementation of an item represented by `did`, build the clean::Item for that impl
-    for &did in tcx.inherent_impls(did).iter() {
+    for &did in tcx.inherent_impls(did).into_iter().flatten() {
         build_impl(cx, did, attrs, ret);
     }
 
@@ -325,7 +325,7 @@ pub(crate) fn build_impls(
     if tcx.has_attr(did, sym::rustc_has_incoherent_inherent_impls) {
         let type_ =
             if tcx.is_trait(did) { SimplifiedType::Trait(did) } else { SimplifiedType::Adt(did) };
-        for &did in tcx.incoherent_impls(type_) {
+        for &did in tcx.incoherent_impls(type_).into_iter().flatten() {
             build_impl(cx, did, attrs, ret);
         }
     }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 90eb783c7ca..6710193f961 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1862,7 +1862,7 @@ impl PrimitiveType {
             .get(self)
             .into_iter()
             .flatten()
-            .flat_map(move |&simp| tcx.incoherent_impls(simp))
+            .flat_map(move |&simp| tcx.incoherent_impls(simp).into_iter().flatten())
             .copied()
     }
 
@@ -1870,7 +1870,7 @@ impl PrimitiveType {
         Self::simplified_types()
             .values()
             .flatten()
-            .flat_map(move |&simp| tcx.incoherent_impls(simp))
+            .flat_map(move |&simp| tcx.incoherent_impls(simp).into_iter().flatten())
             .copied()
     }
 
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index dbff33dc1ec..30b3e5c784d 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -624,7 +624,8 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                 // Checks if item_name belongs to `impl SomeItem`
                 let mut assoc_items: Vec<_> = tcx
                     .inherent_impls(did)
-                    .iter()
+                    .into_iter()
+                    .flatten()
                     .flat_map(|&imp| {
                         filter_assoc_items_by_name_and_namespace(
                             tcx,
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
index d8abe411030..d1fe9f5cbec 100644
--- a/src/tools/clippy/clippy_lints/src/derive.rs
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -386,7 +386,8 @@ fn check_unsafe_derive_deserialize<'tcx>(
         && cx
             .tcx
             .inherent_impls(def.did())
-            .iter()
+            .into_iter()
+            .flatten()
             .map(|imp_did| cx.tcx.hir().expect_item(imp_did.expect_local()))
             .any(|imp| has_unsafe(cx, imp))
     {
diff --git a/src/tools/clippy/clippy_lints/src/inherent_impl.rs b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
index e4781752e75..fb7b82ec304 100644
--- a/src/tools/clippy/clippy_lints/src/inherent_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
@@ -53,9 +53,10 @@ impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
         // List of spans to lint. (lint_span, first_span)
         let mut lint_spans = Vec::new();
 
+        let Ok(impls) = cx.tcx.crate_inherent_impls(()) else { return };
         let inherent_impls = cx
             .tcx
-            .with_stable_hashing_context(|hcx| cx.tcx.crate_inherent_impls(()).inherent_impls.to_sorted(&hcx, true));
+            .with_stable_hashing_context(|hcx| impls.inherent_impls.to_sorted(&hcx, true));
 
         for (_, impl_ids) in inherent_impls.into_iter().filter(|(&id, impls)| {
             impls.len() > 1
diff --git a/src/tools/clippy/clippy_lints/src/iter_without_into_iter.rs b/src/tools/clippy/clippy_lints/src/iter_without_into_iter.rs
index 903d3a2ab89..82a37bb4f27 100644
--- a/src/tools/clippy/clippy_lints/src/iter_without_into_iter.rs
+++ b/src/tools/clippy/clippy_lints/src/iter_without_into_iter.rs
@@ -139,7 +139,7 @@ fn deref_chain<'cx, 'tcx>(cx: &'cx LateContext<'tcx>, ty: Ty<'tcx>) -> impl Iter
 
 fn adt_has_inherent_method(cx: &LateContext<'_>, ty: Ty<'_>, method_name: Symbol) -> bool {
     if let Some(ty_did) = ty.ty_adt_def().map(ty::AdtDef::did) {
-        cx.tcx.inherent_impls(ty_did).iter().any(|&did| {
+        cx.tcx.inherent_impls(ty_did).into_iter().flatten().any(|&did| {
             cx.tcx
                 .associated_items(did)
                 .filter_by_name_unhygienic(method_name)
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index c09d3d1862b..c1ab020117c 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -441,7 +441,8 @@ fn check_for_is_empty(
     let is_empty = cx
         .tcx
         .inherent_impls(impl_ty)
-        .iter()
+        .into_iter()
+        .flatten()
         .flat_map(|&id| cx.tcx.associated_items(id).filter_by_name_unhygienic(is_empty))
         .find(|item| item.kind == AssocKind::Fn);
 
@@ -605,7 +606,7 @@ fn has_is_empty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     /// Checks the inherent impl's items for an `is_empty(self)` method.
     fn has_is_empty_impl(cx: &LateContext<'_>, id: DefId) -> bool {
         let is_empty = sym!(is_empty);
-        cx.tcx.inherent_impls(id).iter().any(|imp| {
+        cx.tcx.inherent_impls(id).into_iter().flatten().any(|imp| {
             cx.tcx
                 .associated_items(*imp)
                 .filter_by_name_unhygienic(is_empty)
diff --git a/src/tools/clippy/clippy_lints/src/methods/or_fun_call.rs b/src/tools/clippy/clippy_lints/src/methods/or_fun_call.rs
index e38c66f6741..0602eeaa704 100644
--- a/src/tools/clippy/clippy_lints/src/methods/or_fun_call.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/or_fun_call.rs
@@ -73,7 +73,8 @@ pub(super) fn check<'tcx>(
         let has_suggested_method = receiver_ty.ty_adt_def().is_some_and(|adt_def| {
             cx.tcx
                 .inherent_impls(adt_def.did())
-                .iter()
+                .into_iter()
+                .flatten()
                 .flat_map(|impl_id| cx.tcx.associated_items(impl_id).filter_by_name_unhygienic(sugg))
                 .any(|assoc| {
                     assoc.fn_has_self_parameter
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 2e54690d123..d264e46f133 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -534,10 +534,11 @@ fn find_primitive_impls<'tcx>(tcx: TyCtxt<'tcx>, name: &str) -> impl Iterator<It
         "u128" => SimplifiedType::Uint(UintTy::U128),
         "f32" => SimplifiedType::Float(FloatTy::F32),
         "f64" => SimplifiedType::Float(FloatTy::F64),
-        _ => return [].iter().copied(),
+        #[allow(trivial_casts)]
+        _ => return Result::<_, rustc_errors::ErrorGuaranteed>::Ok(&[] as &[_]).into_iter().flatten().copied(),
     };
 
-    tcx.incoherent_impls(ty).iter().copied()
+    tcx.incoherent_impls(ty).into_iter().flatten().copied()
 }
 
 fn non_local_item_children_by_name(tcx: TyCtxt<'_>, def_id: DefId, name: Symbol) -> Vec<Res> {
@@ -663,7 +664,8 @@ pub fn def_path_res(cx: &LateContext<'_>, path: &[&str]) -> Vec<Res> {
                 // `impl S { ... }`
                 let inherent_impl_children = tcx
                     .inherent_impls(def_id)
-                    .iter()
+                    .into_iter()
+                    .flatten()
                     .flat_map(|&impl_def_id| item_children_by_name(tcx, impl_def_id, segment));
 
                 let direct_children = item_children_by_name(tcx, def_id, segment);
diff --git a/src/tools/miri/tests/fail-dep/shims/munmap_partial.rs b/src/tools/miri/tests/fail-dep/shims/munmap_partial.rs
index 1d6e4796d0a..d7aef47235f 100644
--- a/src/tools/miri/tests/fail-dep/shims/munmap_partial.rs
+++ b/src/tools/miri/tests/fail-dep/shims/munmap_partial.rs
@@ -1,5 +1,5 @@
 //! The man pages for mmap/munmap suggest that it is possible to partly unmap a previously-mapped
-//! region of addres space, but to LLVM that would be partial deallocation, which LLVM does not
+//! region of address space, but to LLVM that would be partial deallocation, which LLVM does not
 //! support. So even though the man pages say this sort of use is possible, we must report UB.
 //@ignore-target-windows: No libc on Windows
 //@normalize-stderr-test: "size [0-9]+ and alignment" -> "size SIZE and alignment"
diff --git a/tests/debuginfo/collapse-debuginfo-external-attr.rs b/tests/debuginfo/collapse-debuginfo-external-attr.rs
new file mode 100644
index 00000000000..f36b0833ad5
--- /dev/null
+++ b/tests/debuginfo/collapse-debuginfo-external-attr.rs
@@ -0,0 +1,31 @@
+// ignore-lldb
+#![feature(collapse_debuginfo)]
+
+// Test that local macro debug info is not collapsed with #[collapse_debuginfo(external)]
+
+// compile-flags:-g
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:run
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#one_callsite[...]
+// gdb-command:continue
+
+fn one() {
+    println!("one");
+}
+
+#[collapse_debuginfo(external)]
+macro_rules! outer {
+    () => {
+        one(); // #one_callsite
+    };
+}
+
+fn main() {
+    let ret = 0; // #break
+    outer!();
+    std::process::exit(ret);
+}
diff --git a/tests/debuginfo/collapse-debuginfo-external-flag-overriden-by-attr.rs b/tests/debuginfo/collapse-debuginfo-external-flag-overriden-by-attr.rs
new file mode 100644
index 00000000000..e5cbc1a685d
--- /dev/null
+++ b/tests/debuginfo/collapse-debuginfo-external-flag-overriden-by-attr.rs
@@ -0,0 +1,34 @@
+// ignore-lldb
+#![feature(collapse_debuginfo)]
+
+// Test that macro attribute #[collapse_debuginfo(no)]
+// overrides "collapse_macro_debuginfo=external" flag
+
+// compile-flags:-g -Z collapse_macro_debuginfo=external
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:run
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#one_callsite[...]
+// gdb-command:next
+// gdb-command:frame
+// gdb-command:continue
+
+fn one() {
+    println!("one");
+}
+
+#[collapse_debuginfo(no)]
+macro_rules! outer {
+    () => {
+        one(); // #one_callsite
+    };
+}
+
+fn main() {
+    let ret = 0; // #break
+    outer!();
+    std::process::exit(ret);
+}
diff --git a/tests/debuginfo/collapse-debuginfo-external-flag.rs b/tests/debuginfo/collapse-debuginfo-external-flag.rs
new file mode 100644
index 00000000000..9a0aef38ea6
--- /dev/null
+++ b/tests/debuginfo/collapse-debuginfo-external-flag.rs
@@ -0,0 +1,26 @@
+// ignore-lldb
+#![feature(collapse_debuginfo)]
+
+// Test that println macro debug info is collapsed with "collapse_macro_debuginfo=external" flag
+
+// compile-flags:-g -Z collapse_macro_debuginfo=external
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:run
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#println_callsite[...]
+// gdb-command:continue
+
+macro_rules! outer {
+    () => {
+        println!("one"); // #println_callsite
+    };
+}
+
+fn main() {
+    let ret = 0; // #break
+    outer!();
+    std::process::exit(ret);
+}
diff --git a/tests/debuginfo/collapse-debuginfo-no-attr.rs b/tests/debuginfo/collapse-debuginfo-no-attr.rs
index 230c8795be3..d156c381a15 100644
--- a/tests/debuginfo/collapse-debuginfo-no-attr.rs
+++ b/tests/debuginfo/collapse-debuginfo-no-attr.rs
@@ -4,7 +4,7 @@
 // Test that line numbers are not replaced with those of the outermost expansion site when the
 // `collapse_debuginfo` feature is active and the attribute is not provided.
 
-// compile-flags:-g
+// compile-flags:-g -Z collapse_macro_debuginfo=no
 
 // === GDB TESTS ===================================================================================
 
diff --git a/tests/debuginfo/collapse-debuginfo-with-yes-flag.rs b/tests/debuginfo/collapse-debuginfo-with-yes-flag.rs
new file mode 100644
index 00000000000..76a97a325d7
--- /dev/null
+++ b/tests/debuginfo/collapse-debuginfo-with-yes-flag.rs
@@ -0,0 +1,57 @@
+// ignore-lldb
+#![feature(collapse_debuginfo)]
+
+// Test that line numbers are replaced with those of the outermost expansion site when the
+// `collapse_debuginfo` feature is active and the command line flag is provided.
+
+// compile-flags:-g -Z collapse_macro_debuginfo=yes
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:run
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#loc1[...]
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#loc2[...]
+// gdb-command:next
+// gdb-command:frame
+// gdb-check:[...]#loc3[...]
+// gdb-command:continue
+
+fn one() {
+    println!("one");
+}
+fn two() {
+    println!("two");
+}
+fn three() {
+    println!("three");
+}
+fn four() {
+    println!("four");
+}
+
+macro_rules! outer {
+    ($b:block) => {
+        one();
+        inner!();
+        $b
+    };
+}
+
+macro_rules! inner {
+    () => {
+        two();
+    };
+}
+
+fn main() {
+    let ret = 0; // #break
+    outer!({ // #loc1
+        three(); // #loc2
+        four(); // #loc3
+    });
+    std::process::exit(ret);
+}
diff --git a/tests/rustdoc-ui/error-in-impl-trait/README.md b/tests/rustdoc-ui/error-in-impl-trait/README.md
index d969ab10ef5..0b42ff1771e 100644
--- a/tests/rustdoc-ui/error-in-impl-trait/README.md
+++ b/tests/rustdoc-ui/error-in-impl-trait/README.md
@@ -1,5 +1,5 @@
 Each of these needs to be in a separate file,
-because the `span_delayed_bug` ICE in rustdoc won't be triggerred
+because the `span_delayed_bug` ICE in rustdoc won't be triggered
 if even a single other error was emitted.
 
 However, conceptually they are all testing basically the same thing.
diff --git a/tests/ui/asm/inline-syntax.arm.stderr b/tests/ui/asm/inline-syntax.arm.stderr
index 1352fb3771b..6bc38811f1b 100644
--- a/tests/ui/asm/inline-syntax.arm.stderr
+++ b/tests/ui/asm/inline-syntax.arm.stderr
@@ -13,7 +13,7 @@ LL | .intel_syntax noprefix
    | ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:32:15
+  --> $DIR/inline-syntax.rs:38:15
    |
 LL |         asm!(".intel_syntax noprefix", "nop");
    |               ^
@@ -25,7 +25,7 @@ LL |     .intel_syntax noprefix
    |     ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:35:15
+  --> $DIR/inline-syntax.rs:42:15
    |
 LL |         asm!(".intel_syntax aaa noprefix", "nop");
    |               ^
@@ -37,7 +37,7 @@ LL |     .intel_syntax aaa noprefix
    |     ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:38:15
+  --> $DIR/inline-syntax.rs:46:15
    |
 LL |         asm!(".att_syntax noprefix", "nop");
    |               ^
@@ -49,7 +49,7 @@ LL |     .att_syntax noprefix
    |     ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:41:15
+  --> $DIR/inline-syntax.rs:50:15
    |
 LL |         asm!(".att_syntax bbb noprefix", "nop");
    |               ^
@@ -61,7 +61,7 @@ LL |     .att_syntax bbb noprefix
    |     ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:44:15
+  --> $DIR/inline-syntax.rs:54:15
    |
 LL |         asm!(".intel_syntax noprefix; nop");
    |               ^
@@ -73,7 +73,7 @@ LL |     .intel_syntax noprefix; nop
    |     ^
 
 error: unknown directive
-  --> $DIR/inline-syntax.rs:50:13
+  --> $DIR/inline-syntax.rs:61:13
    |
 LL |             .intel_syntax noprefix
    |             ^
diff --git a/tests/ui/asm/inline-syntax.arm_llvm_18.stderr b/tests/ui/asm/inline-syntax.arm_llvm_18.stderr
new file mode 100644
index 00000000000..4926293bb88
--- /dev/null
+++ b/tests/ui/asm/inline-syntax.arm_llvm_18.stderr
@@ -0,0 +1,90 @@
+error: unknown directive
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:1
+   |
+LL | .intel_syntax noprefix
+   | ^
+
+error: unknown directive
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:1
+   |
+LL | .intel_syntax noprefix
+   | ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:38:15
+   |
+LL |         asm!(".intel_syntax noprefix", "nop");
+   |               ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:2
+   |
+LL |     .intel_syntax noprefix
+   |     ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:42:15
+   |
+LL |         asm!(".intel_syntax aaa noprefix", "nop");
+   |               ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:2
+   |
+LL |     .intel_syntax aaa noprefix
+   |     ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:46:15
+   |
+LL |         asm!(".att_syntax noprefix", "nop");
+   |               ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:2
+   |
+LL |     .att_syntax noprefix
+   |     ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:50:15
+   |
+LL |         asm!(".att_syntax bbb noprefix", "nop");
+   |               ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:2
+   |
+LL |     .att_syntax bbb noprefix
+   |     ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:54:15
+   |
+LL |         asm!(".intel_syntax noprefix; nop");
+   |               ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:1:2
+   |
+LL |     .intel_syntax noprefix; nop
+   |     ^
+
+error: unknown directive
+  --> $DIR/inline-syntax.rs:61:13
+   |
+LL |             .intel_syntax noprefix
+   |             ^
+   |
+note: instantiated into assembly here
+  --> <inline asm>:2:13
+   |
+LL |             .intel_syntax noprefix
+   |             ^
+
+error: aborting due to 8 previous errors
+
diff --git a/tests/ui/asm/inline-syntax.rs b/tests/ui/asm/inline-syntax.rs
index d06796e33d5..9398a87df62 100644
--- a/tests/ui/asm/inline-syntax.rs
+++ b/tests/ui/asm/inline-syntax.rs
@@ -1,4 +1,4 @@
-// revisions: x86_64 arm
+// revisions: x86_64 arm arm_llvm_18
 //[x86_64] compile-flags: --target x86_64-unknown-linux-gnu
 //[x86_64] check-pass
 //[x86_64] needs-llvm-components: x86
@@ -8,6 +8,12 @@
 //[arm] compile-flags: --target armv7-unknown-linux-gnueabihf
 //[arm] build-fail
 //[arm] needs-llvm-components: arm
+//[arm] ignore-llvm-version: 18 - 99
+// Newer LLVM produces extra error notes.
+//[arm_llvm_18] compile-flags: --target armv7-unknown-linux-gnueabihf
+//[arm_llvm_18] build-fail
+//[arm_llvm_18] needs-llvm-components: arm
+//[arm_llvm_18] min-llvm-version: 18
 // needs-asm-support
 
 #![feature(no_core, lang_items, rustc_attrs)]
@@ -32,18 +38,23 @@ pub fn main() {
         asm!(".intel_syntax noprefix", "nop");
         //[x86_64]~^ WARN avoid using `.intel_syntax`
         //[arm]~^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^ ERROR unknown directive
         asm!(".intel_syntax aaa noprefix", "nop");
         //[x86_64]~^ WARN avoid using `.intel_syntax`
         //[arm]~^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^ ERROR unknown directive
         asm!(".att_syntax noprefix", "nop");
         //[x86_64]~^ WARN avoid using `.att_syntax`
         //[arm]~^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^ ERROR unknown directive
         asm!(".att_syntax bbb noprefix", "nop");
         //[x86_64]~^ WARN avoid using `.att_syntax`
         //[arm]~^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^ ERROR unknown directive
         asm!(".intel_syntax noprefix; nop");
         //[x86_64]~^ WARN avoid using `.intel_syntax`
         //[arm]~^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^ ERROR unknown directive
 
         asm!(
             r"
@@ -52,6 +63,7 @@ pub fn main() {
         );
         //[x86_64]~^^^ WARN avoid using `.intel_syntax`
         //[arm]~^^^^ ERROR unknown directive
+        //[arm_llvm_18]~^^^^^ ERROR unknown directive
     }
 }
 
diff --git a/tests/ui/asm/inline-syntax.x86_64.stderr b/tests/ui/asm/inline-syntax.x86_64.stderr
index 840b250f87d..b54b3560447 100644
--- a/tests/ui/asm/inline-syntax.x86_64.stderr
+++ b/tests/ui/asm/inline-syntax.x86_64.stderr
@@ -1,5 +1,5 @@
 warning: avoid using `.intel_syntax`, Intel syntax is the default
-  --> $DIR/inline-syntax.rs:58:14
+  --> $DIR/inline-syntax.rs:70:14
    |
 LL | global_asm!(".intel_syntax noprefix", "nop");
    |              ^^^^^^^^^^^^^^^^^^^^^^
@@ -7,37 +7,37 @@ LL | global_asm!(".intel_syntax noprefix", "nop");
    = note: `#[warn(bad_asm_style)]` on by default
 
 warning: avoid using `.intel_syntax`, Intel syntax is the default
-  --> $DIR/inline-syntax.rs:32:15
+  --> $DIR/inline-syntax.rs:38:15
    |
 LL |         asm!(".intel_syntax noprefix", "nop");
    |               ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: avoid using `.intel_syntax`, Intel syntax is the default
-  --> $DIR/inline-syntax.rs:35:15
+  --> $DIR/inline-syntax.rs:42:15
    |
 LL |         asm!(".intel_syntax aaa noprefix", "nop");
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: avoid using `.att_syntax`, prefer using `options(att_syntax)` instead
-  --> $DIR/inline-syntax.rs:38:15
+  --> $DIR/inline-syntax.rs:46:15
    |
 LL |         asm!(".att_syntax noprefix", "nop");
    |               ^^^^^^^^^^^^^^^^^^^^
 
 warning: avoid using `.att_syntax`, prefer using `options(att_syntax)` instead
-  --> $DIR/inline-syntax.rs:41:15
+  --> $DIR/inline-syntax.rs:50:15
    |
 LL |         asm!(".att_syntax bbb noprefix", "nop");
    |               ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: avoid using `.intel_syntax`, Intel syntax is the default
-  --> $DIR/inline-syntax.rs:44:15
+  --> $DIR/inline-syntax.rs:54:15
    |
 LL |         asm!(".intel_syntax noprefix; nop");
    |               ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: avoid using `.intel_syntax`, Intel syntax is the default
-  --> $DIR/inline-syntax.rs:50:13
+  --> $DIR/inline-syntax.rs:61:13
    |
 LL |             .intel_syntax noprefix
    |             ^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs b/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs
index ad73b12feb5..ff265e576b9 100644
--- a/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs
+++ b/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs
@@ -7,6 +7,8 @@ struct Bar;
 impl Foo<char> for Bar {
     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
         //~^ ERROR: the trait bound `impl Foo<u8>: Foo<char>` is not satisfied [E0277]
+        //~| ERROR: the trait bound `Bar: Foo<u8>` is not satisfied [E0277]
+        //~| ERROR: impl has stricter requirements than trait
         self
     }
 }
diff --git a/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr b/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr
index db587d069f8..638de01f913 100644
--- a/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr
+++ b/tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr
@@ -11,6 +11,28 @@ note: required by a bound in `Foo::{opaque#0}`
 LL |     fn foo<F2>(self) -> impl Foo<T>;
    |                              ^^^^^^ required by this bound in `Foo::{opaque#0}`
 
-error: aborting due to 1 previous error
+error[E0276]: impl has stricter requirements than trait
+  --> $DIR/return-dont-satisfy-bounds.rs:8:16
+   |
+LL |     fn foo<F2>(self) -> impl Foo<T>;
+   |     -------------------------------- definition of `foo` from trait
+...
+LL |     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
+   |                ^^^^^^^ impl has extra requirement `F2: Foo<u8>`
+
+error[E0277]: the trait bound `Bar: Foo<u8>` is not satisfied
+  --> $DIR/return-dont-satisfy-bounds.rs:8:34
+   |
+LL |     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
+   |                                  ^^^^^^^^^^^^ the trait `Foo<u8>` is not implemented for `Bar`
+...
+LL |         self
+   |         ---- return type was inferred to be `Bar` here
+   |
+   = help: the trait `Foo<char>` is implemented for `Bar`
+   = help: for that trait implementation, expected `char`, found `u8`
+
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0277`.
+Some errors have detailed explanations: E0276, E0277.
+For more information about an error, try `rustc --explain E0276`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
index 5210a694201..e5b9493b3ce 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
@@ -7,6 +7,16 @@ LL | impl<T: Default> A for T {
 LL | impl<T: Default + ~const Sup> const A for T {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation
 
-error: aborting due to 1 previous error
+error[E0308]: mismatched types
+  --> $DIR/specializing-constness-2.rs:27:5
+   |
+LL |     <T as A>::a();
+   |     ^^^^^^^^^^^^^ expected `host`, found `true`
+   |
+   = note: expected constant `host`
+              found constant `true`
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0119`.
+Some errors have detailed explanations: E0119, E0308.
+For more information about an error, try `rustc --explain E0119`.