Auto merge of #124015 - GuillaumeGomez:rollup-s46ksxa, r=GuillaumeGomez

Rollup of 14 pull requests

Successful merges:

 - #120781 (Correct usage note on OpenOptions::append())
 - #121694 (sess: stabilize `-Zrelro-level` as `-Crelro-level`)
 - #122521 (doc(bootstrap): add top-level doc-comment to utils/tarball.rs)
 - #123491 (Fix ICE in `eval_body_using_ecx`)
 - #123574 (rustdoc: rename `issue-\d+.rs` tests to have meaningful names (part 6))
 - #123687 (Update ar_archive_writer to 0.2.0)
 - #123721 (Various visionOS fixes)
 - #123797 (Better graphviz output for SCCs and NLL constraints)
 - #123990 (Make `suggest_deref_closure_return` more idiomatic/easier to understand)
 - #123995 (Make `thir_tree` and `thir_flat` into hooks)
 - #123998 (Opaque types have no namespace)
 - #124001 (Fix docs for unstable_features lint.)
 - #124006 (Move size assertions for `mir::syntax` types into the same file)
 - #124011 (rustdoc: update the module-level docs of `rustdoc::clean`)

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.lock

@@ -210,9 +210,9 @@ dependencies = [
 
 [[package]]
 name = "ar_archive_writer"
-version = "0.1.5"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9792d37ca5173d7e7f4fe453739a0671d0557915a030a383d6b866476bbc3e71"
+checksum = "f0c269894b6fe5e9d7ada0cf69b5bf847ff35bc25fc271f08e1d080fce80339a"
 dependencies = [
  "object 0.32.2",
 ]

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -26,7 +26,6 @@ use rustc_middle::ty::{self, RegionVid, Ty};
 use rustc_middle::ty::{Region, TyCtxt};
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::Span;
-use rustc_trait_selection::infer::type_variable::TypeVariableOrigin;
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::{Obligation, ObligationCtxt};
 
@@ -813,7 +812,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         self.add_static_impl_trait_suggestion(&mut diag, *fr, fr_name, *outlived_fr);
         self.suggest_adding_lifetime_params(&mut diag, *fr, *outlived_fr);
         self.suggest_move_on_borrowing_closure(&mut diag);
-        self.suggest_deref_closure_value(&mut diag);
+        self.suggest_deref_closure_return(&mut diag);
 
         diag
     }
@@ -1048,115 +1047,107 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     /// When encountering a lifetime error caused by the return type of a closure, check the
     /// corresponding trait bound and see if dereferencing the closure return value would satisfy
     /// them. If so, we produce a structured suggestion.
-    fn suggest_deref_closure_value(&self, diag: &mut Diag<'_>) {
+    fn suggest_deref_closure_return(&self, diag: &mut Diag<'_>) {
         let tcx = self.infcx.tcx;
-        let map = tcx.hir();
 
         // Get the closure return value and type.
-        let body_id = map.body_owned_by(self.mir_def_id());
+        let closure_def_id = self.mir_def_id();
-        let body = &map.body(body_id);
+        let hir::Node::Expr(
-        let value = &body.value.peel_blocks();
+            closure_expr @ hir::Expr {
-        let hir::Node::Expr(closure_expr) = tcx.hir_node_by_def_id(self.mir_def_id()) else {
+                kind: hir::ExprKind::Closure(hir::Closure { body, .. }), ..
+            },
+        ) = tcx.hir_node_by_def_id(closure_def_id)
+        else {
             return;
         };
-        let fn_call_id = tcx.parent_hir_id(self.mir_hir_id());
+        let ty::Closure(_, args) = *tcx.type_of(closure_def_id).instantiate_identity().kind()
-        let hir::Node::Expr(expr) = tcx.hir_node(fn_call_id) else { return };
+        else {
-        let def_id = map.enclosing_body_owner(fn_call_id);
+            return;
-        let tables = tcx.typeck(def_id);
+        };
-        let Some(return_value_ty) = tables.node_type_opt(value.hir_id) else { return };
+        let args = args.as_closure();
-        let return_value_ty = self.infcx.resolve_vars_if_possible(return_value_ty);
+
+        // Make sure that the parent expression is a method call.
+        let parent_expr_id = tcx.parent_hir_id(self.mir_hir_id());
+        let hir::Node::Expr(
+            parent_expr @ hir::Expr {
+                kind: hir::ExprKind::MethodCall(_, rcvr, call_args, _), ..
+            },
+        ) = tcx.hir_node(parent_expr_id)
+        else {
+            return;
+        };
+        let typeck_results = tcx.typeck(self.mir_def_id());
 
         // We don't use `ty.peel_refs()` to get the number of `*`s needed to get the root type.
-        let mut ty = return_value_ty;
+        let liberated_sig = tcx.liberate_late_bound_regions(closure_def_id.to_def_id(), args.sig());
+        let mut peeled_ty = liberated_sig.output();
         let mut count = 0;
-        while let ty::Ref(_, t, _) = ty.kind() {
+        while let ty::Ref(_, ref_ty, _) = *peeled_ty.kind() {
-            ty = *t;
+            peeled_ty = ref_ty;
             count += 1;
         }
-        if !self.infcx.type_is_copy_modulo_regions(self.param_env, ty) {
+        if !self.infcx.type_is_copy_modulo_regions(self.param_env, peeled_ty) {
             return;
         }
 
         // Build a new closure where the return type is an owned value, instead of a ref.
-        let Some(ty::Closure(did, args)) =
-            tables.node_type_opt(closure_expr.hir_id).as_ref().map(|ty| ty.kind())
-        else {
-            return;
-        };
-        let sig = args.as_closure().sig();
         let closure_sig_as_fn_ptr_ty = Ty::new_fn_ptr(
             tcx,
-            sig.map_bound(|s| {
+            ty::Binder::dummy(tcx.mk_fn_sig(
-                let unsafety = hir::Unsafety::Normal;
+                liberated_sig.inputs().iter().copied(),
-                use rustc_target::spec::abi;
+                peeled_ty,
-                tcx.mk_fn_sig(
+                liberated_sig.c_variadic,
-                    [s.inputs()[0]],
+                hir::Unsafety::Normal,
-                    s.output().peel_refs(),
+                rustc_target::spec::abi::Abi::Rust,
-                    s.c_variadic,
+            )),
-                    unsafety,
-                    abi::Abi::Rust,
-                )
-            }),
         );
-        let parent_args = GenericArgs::identity_for_item(
+        let closure_ty = Ty::new_closure(
             tcx,
-            tcx.typeck_root_def_id(self.mir_def_id().to_def_id()),
+            closure_def_id.to_def_id(),
+            ty::ClosureArgs::new(
+                tcx,
+                ty::ClosureArgsParts {
+                    parent_args: args.parent_args(),
+                    closure_kind_ty: args.kind_ty(),
+                    tupled_upvars_ty: args.tupled_upvars_ty(),
+                    closure_sig_as_fn_ptr_ty,
+                },
+            )
+            .args,
         );
-        let closure_kind = args.as_closure().kind();
-        let closure_kind_ty = Ty::from_closure_kind(tcx, closure_kind);
-        let tupled_upvars_ty = self
-            .infcx
-            .next_ty_var(TypeVariableOrigin { param_def_id: None, span: closure_expr.span });
-        let closure_args = ty::ClosureArgs::new(
-            tcx,
-            ty::ClosureArgsParts {
-                parent_args,
-                closure_kind_ty,
-                closure_sig_as_fn_ptr_ty,
-                tupled_upvars_ty,
-            },
-        );
-        let closure_ty = Ty::new_closure(tcx, *did, closure_args.args);
-        let closure_ty = tcx.erase_regions(closure_ty);
 
-        let hir::ExprKind::MethodCall(_, rcvr, args, _) = expr.kind else { return };
+        let Some((closure_arg_pos, _)) =
-        let Some(pos) = args
+            call_args.iter().enumerate().find(|(_, arg)| arg.hir_id == closure_expr.hir_id)
-            .iter()
-            .enumerate()
-            .find(|(_, arg)| arg.hir_id == closure_expr.hir_id)
-            .map(|(i, _)| i)
         else {
             return;
         };
-        // The found `Self` type of the method call.
-        let Some(possible_rcvr_ty) = tables.node_type_opt(rcvr.hir_id) else { return };
-        let Some(method_def_id) = tables.type_dependent_def_id(expr.hir_id) else { return };
-
         // Get the type for the parameter corresponding to the argument the closure with the
         // lifetime error we had.
-        let Some(input) = tcx
+        let Some(method_def_id) = typeck_results.type_dependent_def_id(parent_expr.hir_id) else {
+            return;
+        };
+        let Some(input_arg) = tcx
             .fn_sig(method_def_id)
-            .instantiate_identity()
+            .skip_binder()
             .inputs()
             .skip_binder()
             // Methods have a `self` arg, so `pos` is actually `+ 1` to match the method call arg.
-            .get(pos + 1)
+            .get(closure_arg_pos + 1)
         else {
             return;
         };
-
+        // If this isn't a param, then we can't substitute a new closure.
-        trace!(?input);
+        let ty::Param(closure_param) = input_arg.kind() else { return };
-
-        let ty::Param(closure_param) = input.kind() else { return };
 
         // Get the arguments for the found method, only specifying that `Self` is the receiver type.
+        let Some(possible_rcvr_ty) = typeck_results.node_type_opt(rcvr.hir_id) else { return };
         let args = GenericArgs::for_item(tcx, method_def_id, |param, _| {
             if param.index == 0 {
                 possible_rcvr_ty.into()
             } else if param.index == closure_param.index {
                 closure_ty.into()
             } else {
-                self.infcx.var_for_def(expr.span, param)
+                self.infcx.var_for_def(parent_expr.span, param)
             }
         });
 
@@ -1170,7 +1161,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         if ocx.select_all_or_error().is_empty() {
             diag.span_suggestion_verbose(
-                value.span.shrink_to_lo(),
+                tcx.hir().body(*body).value.peel_blocks().span.shrink_to_lo(),
                 "dereference the return value",
                 "*".repeat(count),
                 Applicability::MachineApplicable,

compiler/rustc_borrowck/src/region_infer/graphviz.rs

@@ -6,7 +6,38 @@ use std::borrow::Cow;
 use std::io::{self, Write};
 
 use super::*;
+use itertools::Itertools;
 use rustc_graphviz as dot;
+use rustc_middle::ty::UniverseIndex;
+
+fn render_outlives_constraint(constraint: &OutlivesConstraint<'_>) -> String {
+    match constraint.locations {
+        Locations::All(_) => "All(...)".to_string(),
+        Locations::Single(loc) => format!("{loc:?}"),
+    }
+}
+
+fn render_universe(u: UniverseIndex) -> String {
+    if u.is_root() {
+        return "".to_string();
+    }
+
+    format!("/{:?}", u)
+}
+
+fn render_region_vid(rvid: RegionVid, regioncx: &RegionInferenceContext<'_>) -> String {
+    let universe_str = render_universe(regioncx.region_definition(rvid).universe);
+
+    let external_name_str = if let Some(external_name) =
+        regioncx.region_definition(rvid).external_name.and_then(|e| e.get_name())
+    {
+        format!(" ({external_name})")
+    } else {
+        "".to_string()
+    };
+
+    format!("{:?}{universe_str}{external_name_str}", rvid)
+}
 
 impl<'tcx> RegionInferenceContext<'tcx> {
     /// Write out the region constraint graph.
@@ -46,10 +77,10 @@ impl<'a, 'this, 'tcx> dot::Labeller<'this> for RawConstraints<'a, 'tcx> {
         Some(dot::LabelText::LabelStr(Cow::Borrowed("box")))
     }
     fn node_label(&'this self, n: &RegionVid) -> dot::LabelText<'this> {
-        dot::LabelText::LabelStr(format!("{n:?}").into())
+        dot::LabelText::LabelStr(render_region_vid(*n, self.regioncx).into())
     }
     fn edge_label(&'this self, e: &OutlivesConstraint<'tcx>) -> dot::LabelText<'this> {
-        dot::LabelText::LabelStr(format!("{:?}", e.locations).into())
+        dot::LabelText::LabelStr(render_outlives_constraint(e).into())
     }
 }
 
@@ -96,8 +127,9 @@ impl<'a, 'this, 'tcx> dot::Labeller<'this> for SccConstraints<'a, 'tcx> {
         Some(dot::LabelText::LabelStr(Cow::Borrowed("box")))
     }
     fn node_label(&'this self, n: &ConstraintSccIndex) -> dot::LabelText<'this> {
-        let nodes = &self.nodes_per_scc[*n];
+        let nodes_str =
-        dot::LabelText::LabelStr(format!("{n:?} = {nodes:?}").into())
+            self.nodes_per_scc[*n].iter().map(|n| render_region_vid(*n, self.regioncx)).join(", ");
+        dot::LabelText::LabelStr(format!("SCC({n}) = {{{nodes_str}}}", n = n.as_usize()).into())
     }
 }
 

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1562,7 +1562,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
 
         // Because this free region must be in the ROOT universe, we
         // know it cannot contain any bound universes.
-        assert!(self.scc_universes[longer_fr_scc] == ty::UniverseIndex::ROOT);
+        assert!(self.scc_universes[longer_fr_scc].is_root());
         debug_assert!(self.scc_values.placeholders_contained_in(longer_fr_scc).next().is_none());
 
         // Only check all of the relations for the main representative of each

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -213,7 +213,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 let scc = self.constraint_sccs.scc(vid);
 
                 // Special handling of higher-ranked regions.
-                if self.scc_universes[scc] != ty::UniverseIndex::ROOT {
+                if !self.scc_universes[scc].is_root() {
                     match self.scc_values.placeholders_contained_in(scc).enumerate().last() {
                         // If the region contains a single placeholder then they're equal.
                         Some((0, placeholder)) => {

compiler/rustc_codegen_ssa/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-ar_archive_writer = "0.1.5"
+ar_archive_writer = "0.2.0"
 bitflags = "2.4.1"
 cc = "1.0.90"
 itertools = "0.12"

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -285,14 +285,7 @@ impl<'a> ArArchiveBuilder<'a> {
             .tempfile_in(output.parent().unwrap_or_else(|| Path::new("")))
             .map_err(|err| io_error_context("couldn't create a temp file", err))?;
 
-        write_archive_to_stream(
+        write_archive_to_stream(archive_tmpfile.as_file_mut(), &entries, archive_kind, false)?;
-            archive_tmpfile.as_file_mut(),
-            &entries,
-            true,
-            archive_kind,
-            true,
-            false,
-        )?;
 
         let any_entries = !entries.is_empty();
         drop(entries);

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -2059,7 +2059,7 @@ fn add_library_search_dirs(cmd: &mut dyn Linker, sess: &Session, self_contained:
 /// Add options making relocation sections in the produced ELF files read-only
 /// and suppressing lazy binding.
 fn add_relro_args(cmd: &mut dyn Linker, sess: &Session) {
-    match sess.opts.unstable_opts.relro_level.unwrap_or(sess.target.relro_level) {
+    match sess.opts.cg.relro_level.unwrap_or(sess.target.relro_level) {
         RelroLevel::Full => cmd.full_relro(),
         RelroLevel::Partial => cmd.partial_relro(),
         RelroLevel::Off => cmd.no_relro(),
@@ -3038,9 +3038,10 @@ fn get_apple_sdk_root(sdk_name: &str) -> Result<String, errors::AppleSdkRootErro
                     || sdkroot.contains("MacOSX.platform") => {}
             "watchsimulator"
                 if sdkroot.contains("WatchOS.platform") || sdkroot.contains("MacOSX.platform") => {}
-            "visionos"
+            "xros"
-                if sdkroot.contains("XROS.platform") || sdkroot.contains("MacOSX.platform") => {}
+                if sdkroot.contains("XRSimulator.platform")
-            "visionossimulator"
+                    || sdkroot.contains("MacOSX.platform") => {}
+            "xrsimulator"
                 if sdkroot.contains("XROS.platform") || sdkroot.contains("MacOSX.platform") => {}
             // Ignore `SDKROOT` if it's not a valid path.
             _ if !p.is_absolute() || p == Path::new("/") || !p.exists() => {}

compiler/rustc_hir/src/def.rs

@@ -207,7 +207,6 @@ impl DefKind {
             | DefKind::Enum
             | DefKind::Variant
             | DefKind::Trait
-            | DefKind::OpaqueTy
             | DefKind::TyAlias
             | DefKind::ForeignTy
             | DefKind::TraitAlias
@@ -234,7 +233,8 @@ impl DefKind {
             | DefKind::Use
             | DefKind::ForeignMod
             | DefKind::GlobalAsm
-            | DefKind::Impl { .. } => None,
+            | DefKind::Impl { .. }
+            | DefKind::OpaqueTy => None,
         }
     }
 

compiler/rustc_interface/src/tests.rs

@@ -624,6 +624,7 @@ fn test_codegen_options_tracking_hash() {
     tracked!(profile_generate, SwitchWithOptPath::Enabled(None));
     tracked!(profile_use, Some(PathBuf::from("abc")));
     tracked!(relocation_model, Some(RelocModel::Pic));
+    tracked!(relro_level, Some(RelroLevel::Full));
     tracked!(soft_float, true);
     tracked!(split_debuginfo, Some(SplitDebuginfo::Packed));
     tracked!(symbol_mangling_version, Some(SymbolManglingVersion::V0));
@@ -822,7 +823,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(profile_sample_use, Some(PathBuf::from("abc")));
     tracked!(profiler_runtime, "abc".to_string());
     tracked!(relax_elf_relocations, Some(true));
-    tracked!(relro_level, Some(RelroLevel::Full));
     tracked!(remap_cwd_prefix, Some(PathBuf::from("abc")));
     tracked!(sanitizer, SanitizerSet::ADDRESS);
     tracked!(sanitizer_cfi_canonical_jump_tables, None);

compiler/rustc_middle/src/hooks/mod.rs

@@ -102,4 +102,10 @@ declare_hooks! {
     /// turn a deserialized `DefPathHash` into its current `DefId`.
     /// Will fetch a DefId from a DefPathHash for a foreign crate.
     hook def_path_hash_to_def_id_extern(hash: DefPathHash, stable_crate_id: StableCrateId) -> DefId;
+
+    /// Create a THIR tree for debugging.
+    hook thir_tree(key: LocalDefId) -> String;
+
+    /// Create a list-like THIR representation for debugging.
+    hook thir_flat(key: LocalDefId) -> String;
 }

compiler/rustc_middle/src/mir/mod.rs

@@ -1823,9 +1823,7 @@ mod size_asserts {
     static_assert_size!(LocalDecl<'_>, 40);
     static_assert_size!(SourceScopeData<'_>, 64);
     static_assert_size!(Statement<'_>, 32);
-    static_assert_size!(StatementKind<'_>, 16);
     static_assert_size!(Terminator<'_>, 112);
-    static_assert_size!(TerminatorKind<'_>, 96);
     static_assert_size!(VarDebugInfo<'_>, 88);
     // tidy-alphabetical-end
 }

compiler/rustc_middle/src/mir/syntax.rs

@@ -1463,5 +1463,6 @@ mod size_asserts {
     static_assert_size!(PlaceElem<'_>, 24);
     static_assert_size!(Rvalue<'_>, 40);
     static_assert_size!(StatementKind<'_>, 16);
+    static_assert_size!(TerminatorKind<'_>, 96);
     // tidy-alphabetical-end
 }

compiler/rustc_middle/src/query/mod.rs

@@ -474,20 +474,6 @@ rustc_queries! {
         desc { |tcx| "building THIR for `{}`", tcx.def_path_str(key) }
     }
 
-    /// Create a THIR tree for debugging.
-    query thir_tree(key: LocalDefId) -> &'tcx String {
-        no_hash
-        arena_cache
-        desc { |tcx| "constructing THIR tree for `{}`", tcx.def_path_str(key) }
-    }
-
-    /// Create a list-like THIR representation for debugging.
-    query thir_flat(key: LocalDefId) -> &'tcx String {
-        no_hash
-        arena_cache
-        desc { |tcx| "constructing flat THIR representation for `{}`", tcx.def_path_str(key) }
-    }
-
     /// Set of all the `DefId`s in this crate that have MIR associated with
     /// them. This includes all the body owners, but also things like struct
     /// constructors.

compiler/rustc_mir_build/src/lib.rs

@@ -34,6 +34,6 @@ pub fn provide(providers: &mut Providers) {
         build::closure_saved_names_of_captured_variables;
     providers.check_unsafety = check_unsafety::check_unsafety;
     providers.thir_body = thir::cx::thir_body;
-    providers.thir_tree = thir::print::thir_tree;
+    providers.hooks.thir_tree = thir::print::thir_tree;
-    providers.thir_flat = thir::print::thir_flat;
+    providers.hooks.thir_flat = thir::print::thir_flat;
 }

compiler/rustc_mir_build/src/thir/print.rs

@@ -1,10 +1,11 @@
+use rustc_middle::query::TyCtxtAt;
 use rustc_middle::thir::*;
-use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty;
 use rustc_span::def_id::LocalDefId;
 use std::fmt::{self, Write};
 
-pub(crate) fn thir_tree(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
+pub(crate) fn thir_tree(tcx: TyCtxtAt<'_>, owner_def: LocalDefId) -> String {
-    match super::cx::thir_body(tcx, owner_def) {
+    match super::cx::thir_body(*tcx, owner_def) {
         Ok((thir, _)) => {
             let thir = thir.steal();
             let mut printer = ThirPrinter::new(&thir);
@@ -15,8 +16,8 @@ pub(crate) fn thir_tree(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
     }
 }
 
-pub(crate) fn thir_flat(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
+pub(crate) fn thir_flat(tcx: TyCtxtAt<'_>, owner_def: LocalDefId) -> String {
-    match super::cx::thir_body(tcx, owner_def) {
+    match super::cx::thir_body(*tcx, owner_def) {
         Ok((thir, _)) => format!("{:#?}", thir.steal()),
         Err(_) => "error".into(),
     }

compiler/rustc_session/src/options.rs

@@ -1534,6 +1534,8 @@ options! {
     relocation_model: Option<RelocModel> = (None, parse_relocation_model, [TRACKED],
         "control generation of position-independent code (PIC) \
         (`rustc --print relocation-models` for details)"),
+    relro_level: Option<RelroLevel> = (None, parse_relro_level, [TRACKED],
+        "choose which RELRO level to use"),
     remark: Passes = (Passes::Some(Vec::new()), parse_passes, [UNTRACKED],
         "output remarks for these optimization passes (space separated, or \"all\")"),
     rpath: bool = (false, parse_bool, [UNTRACKED],
@@ -1881,8 +1883,6 @@ options! {
         "randomize the layout of types (default: no)"),
     relax_elf_relocations: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "whether ELF relocations can be relaxed"),
-    relro_level: Option<RelroLevel> = (None, parse_relro_level, [TRACKED],
-        "choose which RELRO level to use"),
     remap_cwd_prefix: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "remap paths under the current working directory to this path prefix"),
     remap_path_scope: RemapPathScopeComponents = (RemapPathScopeComponents::all(), parse_remap_path_scope, [TRACKED],

compiler/rustc_session/src/session.rs

@@ -573,7 +573,7 @@ impl Session {
 
         let dbg_opts = &self.opts.unstable_opts;
 
-        let relro_level = dbg_opts.relro_level.unwrap_or(self.target.relro_level);
+        let relro_level = self.opts.cg.relro_level.unwrap_or(self.target.relro_level);
 
         // Only enable this optimization by default if full relro is also enabled.
         // In this case, lazy binding was already unavailable, so nothing is lost.

compiler/rustc_target/src/spec/base/apple/mod.rs

@@ -298,6 +298,7 @@ fn link_env_remove(os: &'static str) -> StaticCow<[StaticCow<str>]> {
                 || sdkroot.contains("WatchOS.platform")
                 || sdkroot.contains("WatchSimulator.platform")
                 || sdkroot.contains("XROS.platform")
+                || sdkroot.contains("XRSimulator.platform")
             {
                 env_remove.push("SDKROOT".into())
             }

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

@@ -984,7 +984,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             // Already reported in the query.
             SelectionError::NotConstEvaluatable(NotConstEvaluatable::Error(guar)) |
             // Already reported.
-            Overflow(OverflowError::Error(guar)) => return guar,
+            Overflow(OverflowError::Error(guar)) => {
+                self.set_tainted_by_errors(guar);
+                return guar
+            },
 
             Overflow(_) => {
                 bug!("overflow should be handled before the `report_selection_error` path");

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

@@ -87,6 +87,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             } else if lang_items.sized_trait() == Some(def_id) {
                 // Sized is never implementable by end-users, it is
                 // always automatically computed.
+
+                // FIXME: Consider moving this check to the top level as it
+                // may also be useful for predicates other than `Sized`
+                // Error type cannot possibly implement `Sized` (fixes #123154)
+                if let Err(e) = obligation.predicate.skip_binder().self_ty().error_reported() {
+                    return Err(SelectionError::Overflow(e.into()));
+                }
+
                 let sized_conditions = self.sized_conditions(obligation);
                 self.assemble_builtin_bound_candidates(sized_conditions, &mut candidates);
             } else if lang_items.unsize_trait() == Some(def_id) {

compiler/rustc_ty_utils/src/ty.rs

@@ -91,8 +91,8 @@ fn adt_sized_constraint<'tcx>(
     let tail_ty = tcx.type_of(tail_def.did).instantiate_identity();
 
     let constraint_ty = sized_constraint_for_ty(tcx, tail_ty)?;
-    if constraint_ty.references_error() {
+    if let Err(guar) = constraint_ty.error_reported() {
-        return None;
+        return Some(ty::EarlyBinder::bind(Ty::new_error(tcx, guar)));
     }
 
     // perf hack: if there is a `constraint_ty: Sized` bound, then we know

compiler/rustc_type_ir/src/lib.rs

@@ -346,6 +346,11 @@ impl UniverseIndex {
     pub fn cannot_name(self, other: UniverseIndex) -> bool {
         self < other
     }
+
+    /// Returns `true` if `self` is the root universe, otherwise false.
+    pub fn is_root(self) -> bool {
+        self == Self::ROOT
+    }
 }
 
 impl Default for UniverseIndex {

library/std/src/fs.rs

@@ -980,15 +980,21 @@ impl OpenOptions {
     /// Note that setting `.write(true).append(true)` has the same effect as
     /// setting only `.append(true)`.
     ///
-    /// For most filesystems, the operating system guarantees that all writes are
+    /// Append mode guarantees that writes will be positioned at the current end of file,
-    /// atomic: no writes get mangled because another process writes at the same
+    /// even when there are other processes or threads appending to the same file. This is
-    /// time.
+    /// unlike <code>[seek]\([SeekFrom]::[End]\(0))</code> followed by `write()`, which
+    /// has a race between seeking and writing during which another writer can write, with
+    /// our `write()` overwriting their data.
     ///
-    /// One maybe obvious note when using append-mode: make sure that all data
+    /// Keep in mind that this does not necessarily guarantee that data appended by
-    /// that belongs together is written to the file in one operation. This
+    /// different processes or threads does not interleave. The amount of data accepted a
-    /// can be done by concatenating strings before passing them to [`write()`],
+    /// single `write()` call depends on the operating system and file system. A
-    /// or using a buffered writer (with a buffer of adequate size),
+    /// successful `write()` is allowed to write only part of the given data, so even if
-    /// and calling [`flush()`] when the message is complete.
+    /// you're careful to provide the whole message in a single call to `write()`, there
+    /// is no guarantee that it will be written out in full. If you rely on the filesystem
+    /// accepting the message in a single write, make sure that all data that belongs
+    /// together is written in one operation. This can be done by concatenating strings
+    /// before passing them to [`write()`].
     ///
     /// If a file is opened with both read and append access, beware that after
     /// opening, and after every write, the position for reading may be set at the
@@ -1003,6 +1009,9 @@ impl OpenOptions {
     /// [`write()`]: Write::write "io::Write::write"
     /// [`flush()`]: Write::flush "io::Write::flush"
     /// [stream_position]: Seek::stream_position "io::Seek::stream_position"
+    /// [seek]: Seek::seek "io::Seek::seek"
+    /// [Current]: SeekFrom::Current "io::SeekFrom::Current"
+    /// [End]: SeekFrom::End "io::SeekFrom::End"
     ///
     /// # Examples
     ///

library/std/src/sys/pal/unix/process/process_unix.rs

@@ -11,18 +11,6 @@ use crate::os::linux::process::PidFd;
 #[cfg(target_os = "linux")]
 use crate::os::unix::io::AsRawFd;
 
-#[cfg(any(
-    target_os = "macos",
-    target_os = "watchos",
-    target_os = "visionos",
-    target_os = "tvos",
-    target_os = "freebsd",
-    all(target_os = "linux", target_env = "gnu"),
-    all(target_os = "linux", target_env = "musl"),
-    target_os = "nto",
-))]
-use crate::sys::weak::weak;
-
 #[cfg(target_os = "vxworks")]
 use libc::RTP_ID as pid_t;
 
@@ -466,6 +454,7 @@ impl Command {
         envp: Option<&CStringArray>,
     ) -> io::Result<Option<Process>> {
         use crate::mem::MaybeUninit;
+        use crate::sys::weak::weak;
         use crate::sys::{self, cvt_nz, unix_sigpipe_attr_specified};
 
         if self.get_gid().is_some()

src/bootstrap/src/utils/tarball.rs

@@ -1,3 +1,10 @@
+//! Facilitates the management and generation of tarballs.
+//!
+//! Tarballs efficiently hold Rust compiler build artifacts and
+//! capture a snapshot of each boostrap stage.
+//! In uplifting, a tarball from Stage N captures essential components
+//! to assemble Stage N + 1 compiler.
+
 use std::{
     path::{Path, PathBuf},
     process::Command,

src/doc/rustc/src/codegen-options/index.md

@@ -479,6 +479,26 @@ then `-C target-feature=+crt-static` "wins" over `-C relocation-model=pic`,
 and the linker is instructed (`-static`) to produce a statically linked
 but not position-independent executable.
 
+## relro-level
+
+This flag controls what level of RELRO (Relocation Read-Only) is enabled. RELRO is an exploit
+mitigation which makes the Global Offset Table (GOT) read-only.
+
+Supported values for this option are:
+
+- `off`: Dynamically linked functions are resolved lazily and the GOT is writable.
+- `partial`: Dynamically linked functions are resolved lazily and written into the Procedure
+  Linking Table (PLT) part of the GOT (`.got.plt`). The non-PLT part of the GOT (`.got`) is made
+  read-only and both are moved to prevent writing from buffer overflows.
+- `full`: Dynamically linked functions are resolved at the start of program execution and the
+  Global Offset Table (`.got`/`.got.plt`) is populated eagerly and then made read-only. The GOT is
+  also moved to prevent writing from buffer overflows. Full RELRO uses more memory and increases
+  process startup time.
+
+This flag is ignored on platforms where RELRO is not supported (targets which do not use the ELF
+binary format), such as Windows or macOS. Each rustc target has its own default for RELRO. rustc
+enables Full RELRO by default on platforms where it is supported.
+
 ## remark
 
 This flag lets you print remarks for optimization passes.

src/librustdoc/clean/mod.rs

@@ -1,5 +1,25 @@
-//! This module contains the "cleaned" pieces of the AST, and the functions
+//! This module defines the primary IR[^1] used in rustdoc together with the procedures that
-//! that clean them.
+//! transform rustc data types into it.
+//!
+//! This IR — commonly referred to as the *cleaned AST* — is modeled after the [AST][ast].
+//!
+//! There are two kinds of transformation — *cleaning* — procedures:
+//!
+//! 1. Cleans [HIR][hir] types. Used for user-written code and inlined local re-exports
+//!    both found in the local crate.
+//! 2. Cleans [`rustc_middle::ty`] types. Used for inlined cross-crate re-exports and anything
+//!    output by the trait solver (e.g., when synthesizing blanket and auto-trait impls).
+//!    They usually have `ty` or `middle` in their name.
+//!
+//! Their name is prefixed by `clean_`.
+//!
+//! Both the HIR and the `rustc_middle::ty` IR are quite removed from the source code.
+//! The cleaned AST on the other hand is closer to it which simplifies the rendering process.
+//! Furthermore, operating on a single IR instead of two avoids duplicating efforts down the line.
+//!
+//! This IR is consumed by both the HTML and the JSON backend.
+//!
+//! [^1]: Intermediate representation.
 
 mod auto_trait;
 mod blanket_impl;

src/tools/lint-docs/src/lib.rs

@@ -270,7 +270,6 @@ impl<'a> LintExtractor<'a> {
         if matches!(
             lint.name.as_str(),
             "unused_features" // broken lint
-            | "unstable_features" // deprecated
         ) {
             return Ok(());
         }

tests/crashes/123154.rs

@@ -1,12 +0,0 @@
-//@ known-bug: #123154
-struct AA {
-    pub data: [&usize]
-}
-
-impl AA {
-    const fn new() -> Self { }
-}
-
-static AA = AA::new();
-
-fn main() { }

tests/run-make/relro-levels/Makefile

@@ -3,20 +3,20 @@ include ../tools.mk
 
 # only-linux
 #
-# This tests the different -Zrelro-level values, and makes sure that they work properly.
+# This tests the different -Crelro-level values, and makes sure that they work properly.
 
 all:
 	# Ensure that binaries built with the full relro level links them with both
 	# RELRO and BIND_NOW for doing eager symbol resolving.
-	$(RUSTC) -Zrelro-level=full hello.rs
+	$(RUSTC) -Crelro-level=full hello.rs
 	readelf -l $(TMPDIR)/hello | grep -q GNU_RELRO
 	readelf -d $(TMPDIR)/hello | grep -q BIND_NOW
 
-	$(RUSTC) -Zrelro-level=partial hello.rs
+	$(RUSTC) -Crelro-level=partial hello.rs
 	readelf -l $(TMPDIR)/hello | grep -q GNU_RELRO
 
 	# Ensure that we're *not* built with RELRO when setting it to off.  We do
 	# not want to check for BIND_NOW however, as the linker might have that
 	# enabled by default.
-	$(RUSTC) -Zrelro-level=off hello.rs
+	$(RUSTC) -Crelro-level=off hello.rs
 	! readelf -l $(TMPDIR)/hello | grep -q GNU_RELRO

tests/rustdoc-ui/ice-blanket-impl-56701.rs

@@ -1,4 +1,6 @@
+//@ check-pass
 // This shouldn't cause a stack overflow when rustdoc is run
+// https://github.com/rust-lang/rust/issues/56701
 
 use std::ops::Deref;
 use std::ops::DerefMut;

tests/rustdoc-ui/ice-cross-crate-opaque-assoc-type-73061.rs

@@ -1,5 +1,6 @@
-// Regression test for ICE #73061
+// Regression test for ICE https://github.com/rust-lang/rust/issues/73061
 
+//@ check-pass
 //@ aux-build:issue-73061.rs
 
 extern crate issue_73061;

tests/rustdoc/blanket-impl-78673.rs

@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/78673
 #![crate_name = "issue_78673"]
 
 pub trait Something {}

tests/rustdoc/const-fn-76501.rs

@@ -1,4 +1,7 @@
-// @has 'issue_76501/fn.bloop.html' '//pre' 'pub const fn bloop() -> i32'
+// https://github.com/rust-lang/rust/issues/76501
+#![crate_name="foo"]
+
+// @has 'foo/fn.bloop.html' '//pre' 'pub const fn bloop() -> i32'
 /// A useless function that always returns 1.
 pub const fn bloop() -> i32 {
     1
@@ -8,7 +11,7 @@ pub const fn bloop() -> i32 {
 pub struct Struct {}
 
 impl Struct {
-    // @has 'issue_76501/struct.Struct.html' '//*[@class="method"]' \
+    // @has 'foo/struct.Struct.html' '//*[@class="method"]' \
     // 'pub const fn blurp() -> i32'
     /// A useless function that always returns 1.
     pub const fn blurp() -> i32 {

tests/rustdoc/doc-cfg-inherit-from-module-79201.rs

@@ -1,6 +1,9 @@
+// https://github.com/rust-lang/rust/issues/79201
+#![crate_name="foo"]
+
 #![feature(doc_cfg)]
 
-// @has 'issue_79201/trait.Foo.html'
+// @has 'foo/trait.Foo.html'
 // @count   - '//*[@class="stab portability"]' 6
 // @matches - '//*[@class="stab portability"]' 'crate feature foo-root'
 // @matches - '//*[@class="stab portability"]' 'crate feature foo-public-mod'

tests/rustdoc/doc-hidden-private-67851-both.rs

@@ -1,8 +1,10 @@
 //@ compile-flags: -Zunstable-options --document-private-items --document-hidden-items
+// https://github.com/rust-lang/rust/issues/67851
+#![crate_name="foo"]
 
-// @has issue_67851_both/struct.Hidden.html
+// @has foo/struct.Hidden.html
 #[doc(hidden)]
 pub struct Hidden;
 
-// @has issue_67851_both/struct.Private.html
+// @has foo/struct.Private.html
 struct Private;

tests/rustdoc/doc-hidden-private-67851-hidden.rs

@@ -0,0 +1,10 @@
+//@ compile-flags: -Zunstable-options --document-hidden-items
+// https://github.com/rust-lang/rust/issues/67851
+#![crate_name="foo"]
+
+// @has foo/struct.Hidden.html
+#[doc(hidden)]
+pub struct Hidden;
+
+// @!has foo/struct.Private.html
+struct Private;

tests/rustdoc/doc-hidden-private-67851-neither.rs

@@ -0,0 +1,9 @@
+// https://github.com/rust-lang/rust/issues/67851
+#![crate_name="foo"]
+
+// @!has foo/struct.Hidden.html
+#[doc(hidden)]
+pub struct Hidden;
+
+// @!has foo/struct.Private.html
+struct Private;

tests/rustdoc/doc-hidden-private-67851-private.rs

@@ -0,0 +1,10 @@
+//@ compile-flags: --document-private-items
+// https://github.com/rust-lang/rust/issues/67851
+#![crate_name="foo"]
+
+// @!has foo/struct.Hidden.html
+#[doc(hidden)]
+pub struct Hidden;
+
+// @has foo/struct.Private.html
+struct Private;

tests/rustdoc/hide-mut-methods-if-no-derefmut-impl-74083.rs

@@ -1,3 +1,6 @@
+// https://github.com/rust-lang/rust/issues/74083
+#![crate_name="foo"]
+
 use std::ops::Deref;
 
 pub struct Foo;
@@ -6,7 +9,7 @@ impl Foo {
     pub fn foo(&mut self) {}
 }
 
-// @has issue_74083/struct.Bar.html
+// @has foo/struct.Bar.html
 // @!has - '//div[@class="sidebar-links"]/a[@href="#method.foo"]' 'foo'
 pub struct Bar {
     foo: Foo,

tests/rustdoc/implementors-unstable-75588.rs

@@ -2,6 +2,7 @@
 //@ aux-build:real_gimli.rs
 
 // Ensure unstably exported traits have their Implementors sections.
+// https://github.com/rust-lang/rust/issues/75588
 
 #![crate_name = "foo"]
 #![feature(extremely_unstable_foo)]

tests/rustdoc/inline_cross/ice-import-crate-57180.rs

@@ -1,4 +1,5 @@
 //@ aux-build:issue-57180.rs
+// https://github.com/rust-lang/rust/issues/57180
 
 extern crate issue_57180;
 use issue_57180::Trait;

tests/rustdoc/intra-doc-link-method-trait-impl-72340.rs

@@ -1,3 +1,5 @@
+// https://github.com/rust-lang/rust/issues/72340
+
 #![crate_name = "foo"]
 
 pub struct Body;

tests/rustdoc/issue-67851-hidden.rs

@@ -1,8 +0,0 @@
-//@ compile-flags: -Zunstable-options --document-hidden-items
-
-// @has issue_67851_hidden/struct.Hidden.html
-#[doc(hidden)]
-pub struct Hidden;
-
-// @!has issue_67851_hidden/struct.Private.html
-struct Private;

tests/rustdoc/issue-67851-neither.rs

@@ -1,6 +0,0 @@
-// @!has issue_67851_neither/struct.Hidden.html
-#[doc(hidden)]
-pub struct Hidden;
-
-// @!has issue_67851_neither/struct.Private.html
-struct Private;

tests/rustdoc/issue-67851-private.rs

@@ -1,8 +0,0 @@
-//@ compile-flags: --document-private-items
-
-// @!has issue_67851_private/struct.Hidden.html
-#[doc(hidden)]
-pub struct Hidden;
-
-// @has issue_67851_private/struct.Private.html
-struct Private;

tests/rustdoc/markdown-60482.rs

@@ -1,4 +1,5 @@
 // This code caused a panic in `pulldown-cmark` 0.4.1.
+// https://github.com/rust-lang/rust/issues/60482
 
 pub const BASIC_UNICODE: bool = true;
 

tests/rustdoc/sidebar-trait-impl-disambiguate-78701.rs

@@ -1,3 +1,4 @@
+// https://github.com/rust-lang/rust/issues/78701
 #![crate_name = "foo"]
 
 // This test ensures that if a blanket impl has the same ID as another impl, it'll

tests/rustdoc/synthetic_auto/auto-trait-lifetimes-56822.rs

@@ -1,3 +1,6 @@
+// https://github.com/rust-lang/rust/issues/56822
+#![crate_name="foo"]
+
 struct Wrapper<T>(T);
 
 trait MyTrait {
@@ -16,7 +19,7 @@ impl<'a, T> MyTrait for Inner<'a, T> {
     type Output = &'a T;
 }
 
-// @has issue_56822/struct.Parser.html
+// @has foo/struct.Parser.html
 // @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<'a> Send for Parser<'a>"
 pub struct Parser<'a> {

tests/rustdoc/synthetic_auto/send-impl-conditional-60726.rs

@@ -1,3 +1,6 @@
+// https://github.com/rust-lang/rust/issues/60726
+#![crate_name="foo"]
+
 use std::marker::PhantomData;
 
 pub struct True;
@@ -25,7 +28,7 @@ where
     I:InterfaceType<Send=True>
 {}
 
-// @has issue_60726/struct.IntoIter.html
+// @has foo/struct.IntoIter.html
 // @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \
 // "impl<T> !Send for IntoIter<T>"
 // @has - '//*[@id="synthetic-implementations-list"]//*[@class="impl"]//h3[@class="code-header"]' \

tests/rustdoc/underscore-import-61592.rs

@@ -1,14 +1,16 @@
 //@ aux-build:issue-61592.rs
+// https://github.com/rust-lang/rust/issues/61592
+#![crate_name="bar"]
 
 extern crate foo;
 
-// @has issue_61592/index.html
+// @has bar/index.html
 // @has - '//a[@href="#reexports"]' 'Re-exports'
 // @has - '//code' 'pub use foo::FooTrait as _;'
 // @!has - '//a[@href="trait._.html"]' ''
 pub use foo::FooTrait as _;
 
-// @has issue_61592/index.html
+// @has bar/index.html
 // @has - '//a[@href="#reexports"]' 'Re-exports'
 // @has - '//code' 'pub use foo::FooStruct as _;'
 // @!has - '//a[@href="struct._.html"]' ''

tests/ui/closures/issue-78720.rs

@@ -1,6 +1,5 @@
 fn server() -> impl {
     //~^ ERROR at least one trait must be specified
-    //~| ERROR type annotations needed
     ().map2(|| "")
 }
 

tests/ui/closures/issue-78720.stderr

@@ -5,7 +5,7 @@ LL | fn server() -> impl {
    |                ^^^^
 
 error[E0412]: cannot find type `F` in this scope
-  --> $DIR/issue-78720.rs:14:12
+  --> $DIR/issue-78720.rs:13:12
    |
 LL |     _func: F,
    |            ^
@@ -22,14 +22,8 @@ help: you might be missing a type parameter
 LL | struct Map2<Segment2, F> {
    |                     +++
 
-error[E0282]: type annotations needed
-  --> $DIR/issue-78720.rs:1:16
-   |
-LL | fn server() -> impl {
-   |                ^^^^ cannot infer type
-
 error[E0308]: mismatched types
-  --> $DIR/issue-78720.rs:8:39
+  --> $DIR/issue-78720.rs:7:39
    |
 LL |     fn map2<F>(self, f: F) -> Map2<F> {}
    |                                       ^^ expected `Map2<F>`, found `()`
@@ -38,7 +32,7 @@ LL |     fn map2<F>(self, f: F) -> Map2<F> {}
            found unit type `()`
 
 error[E0277]: the size for values of type `Self` cannot be known at compilation time
-  --> $DIR/issue-78720.rs:8:16
+  --> $DIR/issue-78720.rs:7:16
    |
 LL |     fn map2<F>(self, f: F) -> Map2<F> {}
    |                ^^^^ doesn't have a size known at compile-time
@@ -53,7 +47,7 @@ help: function arguments must have a statically known size, borrowed types alway
 LL |     fn map2<F>(&self, f: F) -> Map2<F> {}
    |                +
 
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0277, E0282, E0308, E0412.
+Some errors have detailed explanations: E0277, E0308, E0412.
 For more information about an error, try `rustc --explain E0277`.

tests/ui/const_prop/ice-type-mismatch-when-copying-112824.rs

@@ -13,7 +13,6 @@ impl Opcode2 {
 pub fn example2(msg_type: Opcode2) -> impl FnMut(&[u8]) {
     move |i| match msg_type {
         Opcode2::OP2 => unimplemented!(),
-        //~^ ERROR could not evaluate constant pattern
     }
 }
 

tests/ui/const_prop/ice-type-mismatch-when-copying-112824.stderr

@@ -17,13 +17,7 @@ help: you might be missing a type parameter
 LL | pub struct Opcode2<S>(&'a S);
    |                   +++
 
-error: could not evaluate constant pattern
+error: aborting due to 2 previous errors
-  --> $DIR/ice-type-mismatch-when-copying-112824.rs:15:9
-   |
-LL |         Opcode2::OP2 => unimplemented!(),
-   |         ^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
 
 Some errors have detailed explanations: E0261, E0412.
 For more information about an error, try `rustc --explain E0261`.

tests/ui/consts/const-eval/ice-unsized-struct-const-eval-123154.rs

@@ -0,0 +1,15 @@
+// Regression test for #123154
+
+struct AA {
+    pub data: [&usize]
+    //~^ ERROR missing lifetime specifier
+}
+
+impl AA {
+    const fn new() -> Self { }
+    //~^ ERROR mismatched types
+}
+
+static ST: AA = AA::new();
+
+fn main() {}

tests/ui/consts/const-eval/ice-unsized-struct-const-eval-123154.stderr

@@ -0,0 +1,24 @@
+error[E0106]: missing lifetime specifier
+  --> $DIR/ice-unsized-struct-const-eval-123154.rs:4:16
+   |
+LL |     pub data: [&usize]
+   |                ^ expected named lifetime parameter
+   |
+help: consider introducing a named lifetime parameter
+   |
+LL ~ struct AA<'a> {
+LL ~     pub data: [&'a usize]
+   |
+
+error[E0308]: mismatched types
+  --> $DIR/ice-unsized-struct-const-eval-123154.rs:9:23
+   |
+LL |     const fn new() -> Self { }
+   |              ---      ^^^^ expected `AA`, found `()`
+   |              |
+   |              implicitly returns `()` as its body has no tail or `return` expression
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0106, E0308.
+For more information about an error, try `rustc --explain E0106`.

tests/ui/specialization/issue-68830-spurious-diagnostics.rs

@@ -17,6 +17,7 @@ impl<T, D> MyTrait<T> for D {
 }
 
 impl<T> MyTrait<T> for BadStruct {
+//~^ ERROR: conflicting implementations of trait `MyTrait<_>` for type `BadStruct`
     fn foo() {}
 }
 

tests/ui/specialization/issue-68830-spurious-diagnostics.stderr

@@ -4,6 +4,16 @@ error[E0412]: cannot find type `MissingType` in this scope
 LL |     err: MissingType
    |          ^^^^^^^^^^^ not found in this scope
 
-error: aborting due to 1 previous error
+error[E0119]: conflicting implementations of trait `MyTrait<_>` for type `BadStruct`
+  --> $DIR/issue-68830-spurious-diagnostics.rs:19:1
+   |
+LL | impl<T, D> MyTrait<T> for D {
+   | --------------------------- first implementation here
+...
+LL | impl<T> MyTrait<T> for BadStruct {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `BadStruct`
 
-For more information about this error, try `rustc --explain E0412`.
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0119, E0412.
+For more information about an error, try `rustc --explain E0119`.