Auto merge of #110252 - matthiaskrgr:rollup-ovaixra, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #109810 (Replace rustdoc-ui/{c,z}-help tests with a stable run-make test )
 - #110035 (fix: ensure bad `#[test]` invocs retain correct AST)
 - #110089 (sync::mpsc: synchronize receiver disconnect with initialization)
 - #110103 (Report overflows gracefully with new solver)
 - #110122 (Fix x check --stage 1 when download-ci-llvm=false)
 - #110133 (Do not use ImplDerivedObligationCause for inherent impl method error reporting)
 - #110135 (Revert "Don't recover lifetimes/labels containing emojis as character literals")
 - #110235 (Fix `--extend-css` option)

Failed merges:

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

compiler/rustc_builtin_macros/src/test.rs

@@ -118,34 +118,22 @@ pub fn expand_test_or_bench(
             }
         }
         other => {
-            cx.struct_span_err(
+            not_testable_error(cx, attr_sp, None);
-                other.span(),
-                "`#[test]` attribute is only allowed on non associated functions",
-            )
-            .emit();
             return vec![other];
         }
     };
 
-    // Note: non-associated fn items are already handled by `expand_test_or_bench`
     let ast::ItemKind::Fn(fn_) = &item.kind else {
-        let diag = &cx.sess.parse_sess.span_diagnostic;
+        not_testable_error(cx, attr_sp, Some(&item));
-        let msg = "the `#[test]` attribute may only be used on a non-associated function";
+        return if is_stmt {
-        let mut err = match item.kind {
+            vec![Annotatable::Stmt(P(ast::Stmt {
-            // These were a warning before #92959 and need to continue being that to avoid breaking
+                id: ast::DUMMY_NODE_ID,
-            // stable user code (#94508).
+                span: item.span,
-            ast::ItemKind::MacCall(_) => diag.struct_span_warn(attr_sp, msg),
+                kind: ast::StmtKind::Item(item),
-            // `.forget_guarantee()` needed to get these two arms to match types. Because of how
+            }))]
-            // locally close the `.emit()` call is I'm comfortable with it, but if it can be
+        } else {
-            // reworked in the future to not need it, it'd be nice.
+            vec![Annotatable::Item(item)]
-            _ => diag.struct_span_err(attr_sp, msg).forget_guarantee(),
         };
-        err.span_label(attr_sp, "the `#[test]` macro causes a function to be run on a test and has no effect on non-functions")
-            .span_label(item.span, format!("expected a non-associated function, found {} {}", item.kind.article(), item.kind.descr()))
-            .span_suggestion(attr_sp, "replace with conditional compilation to make the item only exist when tests are being run", "#[cfg(test)]", Applicability::MaybeIncorrect)
-            .emit();
-
-        return vec![Annotatable::Item(item)];
     };
 
     // has_*_signature will report any errors in the type so compilation
@@ -398,6 +386,36 @@ pub fn expand_test_or_bench(
     }
 }
 
+fn not_testable_error(cx: &ExtCtxt<'_>, attr_sp: Span, item: Option<&ast::Item>) {
+    let diag = &cx.sess.parse_sess.span_diagnostic;
+    let msg = "the `#[test]` attribute may only be used on a non-associated function";
+    let mut err = match item.map(|i| &i.kind) {
+        // These were a warning before #92959 and need to continue being that to avoid breaking
+        // stable user code (#94508).
+        Some(ast::ItemKind::MacCall(_)) => diag.struct_span_warn(attr_sp, msg),
+        // `.forget_guarantee()` needed to get these two arms to match types. Because of how
+        // locally close the `.emit()` call is I'm comfortable with it, but if it can be
+        // reworked in the future to not need it, it'd be nice.
+        _ => diag.struct_span_err(attr_sp, msg).forget_guarantee(),
+    };
+    if let Some(item) = item {
+        err.span_label(
+            item.span,
+            format!(
+                "expected a non-associated function, found {} {}",
+                item.kind.article(),
+                item.kind.descr()
+            ),
+        );
+    }
+    err.span_label(attr_sp, "the `#[test]` macro causes a function to be run as a test and has no effect on non-functions")
+        .span_suggestion(attr_sp,
+            "replace with conditional compilation to make the item only exist when tests are being run",
+            "#[cfg(test)]",
+            Applicability::MaybeIncorrect)
+        .emit();
+}
+
 fn get_location_info(cx: &ExtCtxt<'_>, item: &ast::Item) -> (Symbol, usize, usize, usize, usize) {
     let span = item.ident.span;
     let (source_file, lo_line, lo_col, hi_line, hi_col) =

compiler/rustc_driver_impl/src/lib.rs

@@ -37,7 +37,7 @@ use rustc_metadata::locator;
 use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS};
 use rustc_session::config::{ErrorOutputType, Input, OutputType, PrintRequest, TrimmedDefPaths};
 use rustc_session::cstore::MetadataLoader;
-use rustc_session::getopts;
+use rustc_session::getopts::{self, Matches};
 use rustc_session::lint::{Lint, LintId};
 use rustc_session::{config, Session};
 use rustc_session::{early_error, early_error_no_abort, early_warn};
@@ -956,6 +956,46 @@ Available lint options:
     }
 }
 
+/// Show help for flag categories shared between rustdoc and rustc.
+///
+/// Returns whether a help option was printed.
+pub fn describe_flag_categories(matches: &Matches) -> bool {
+    // Handle the special case of -Wall.
+    let wall = matches.opt_strs("W");
+    if wall.iter().any(|x| *x == "all") {
+        print_wall_help();
+        rustc_errors::FatalError.raise();
+    }
+
+    // Don't handle -W help here, because we might first load plugins.
+    let debug_flags = matches.opt_strs("Z");
+    if debug_flags.iter().any(|x| *x == "help") {
+        describe_debug_flags();
+        return true;
+    }
+
+    let cg_flags = matches.opt_strs("C");
+    if cg_flags.iter().any(|x| *x == "help") {
+        describe_codegen_flags();
+        return true;
+    }
+
+    if cg_flags.iter().any(|x| *x == "no-stack-check") {
+        early_warn(
+            ErrorOutputType::default(),
+            "the --no-stack-check flag is deprecated and does nothing",
+        );
+    }
+
+    if cg_flags.iter().any(|x| *x == "passes=list") {
+        let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
+        get_codegen_backend(&None, backend_name).print_passes();
+        return true;
+    }
+
+    false
+}
+
 fn describe_debug_flags() {
     println!("\nAvailable options:\n");
     print_flag_list("-Z", config::Z_OPTIONS);
@@ -966,7 +1006,7 @@ fn describe_codegen_flags() {
     print_flag_list("-C", config::CG_OPTIONS);
 }
 
-pub fn print_flag_list<T>(
+fn print_flag_list<T>(
     cmdline_opt: &str,
     flag_list: &[(&'static str, T, &'static str, &'static str)],
 ) {
@@ -1059,37 +1099,7 @@ pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
         return None;
     }
 
-    // Handle the special case of -Wall.
+    if describe_flag_categories(&matches) {
-    let wall = matches.opt_strs("W");
-    if wall.iter().any(|x| *x == "all") {
-        print_wall_help();
-        rustc_errors::FatalError.raise();
-    }
-
-    // Don't handle -W help here, because we might first load plugins.
-    let debug_flags = matches.opt_strs("Z");
-    if debug_flags.iter().any(|x| *x == "help") {
-        describe_debug_flags();
-        return None;
-    }
-
-    let cg_flags = matches.opt_strs("C");
-
-    if cg_flags.iter().any(|x| *x == "help") {
-        describe_codegen_flags();
-        return None;
-    }
-
-    if cg_flags.iter().any(|x| *x == "no-stack-check") {
-        early_warn(
-            ErrorOutputType::default(),
-            "the --no-stack-check flag is deprecated and does nothing",
-        );
-    }
-
-    if cg_flags.iter().any(|x| *x == "passes=list") {
-        let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
-        get_codegen_backend(&None, backend_name).print_passes();
         return None;
     }
 

compiler/rustc_errors/src/lib.rs

@@ -475,8 +475,6 @@ pub enum StashKey {
     /// When an invalid lifetime e.g. `'2` should be reinterpreted
     /// as a char literal in the parser
     LifetimeIsChar,
-    /// When an invalid lifetime e.g. `'🐱` contains emoji.
-    LifetimeContainsEmoji,
     /// Maybe there was a typo where a comma was forgotten before
     /// FRU syntax
     MaybeFruTypo,

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -578,7 +578,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     #[instrument(skip(self), level = "debug")]
     pub(in super::super) fn report_ambiguity_errors(&self) {
-        let mut errors = self.fulfillment_cx.borrow_mut().collect_remaining_errors();
+        let mut errors = self.fulfillment_cx.borrow_mut().collect_remaining_errors(self);
 
         if !errors.is_empty() {
             self.adjust_fulfillment_errors_for_expr_obligation(&mut errors);

compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs

@@ -78,7 +78,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Finally, for ambiguity-related errors, we actually want to look
         // for a parameter that is the source of the inference type left
         // over in this predicate.
-        if let traits::FulfillmentErrorCode::CodeAmbiguity = error.code {
+        if let traits::FulfillmentErrorCode::CodeAmbiguity { .. } = error.code {
             fallback_param_to_point_at = None;
             self_param_to_point_at = None;
             param_to_point_at =

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -1531,23 +1531,18 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
                     // Convert the bounds into obligations.
                     let impl_obligations = traits::predicates_for_generics(
-                        |_idx, span| {
+                        |idx, span| {
-                            let misc = traits::ObligationCause::misc(span, self.body_id);
+                            let code = if span.is_dummy() {
-                            let parent_trait_pred = ty::Binder::dummy(ty::TraitPredicate {
+                                traits::ExprItemObligation(impl_def_id, self.scope_expr_id, idx)
-                                trait_ref: ty::TraitRef::from_method(self.tcx, impl_def_id, substs),
+                            } else {
-                                constness: ty::BoundConstness::NotConst,
+                                traits::ExprBindingObligation(
-                                polarity: ty::ImplPolarity::Positive,
+                                    impl_def_id,
-                            });
+                                    span,
-                            misc.derived_cause(parent_trait_pred, |derived| {
+                                    self.scope_expr_id,
-                                traits::ImplDerivedObligation(Box::new(
+                                    idx,
-                                    traits::ImplDerivedObligationCause {
+                                )
-                                        derived,
+                            };
-                                        impl_or_alias_def_id: impl_def_id,
+                            ObligationCause::new(self.span, self.body_id, code)
-                                        impl_def_predicate_index: None,
-                                        span,
-                                    },
-                                ))
-                            })
                         },
                         self.param_env,
                         impl_bounds,

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -661,19 +661,26 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Find all the requirements that come from a local `impl` block.
             let mut skip_list: FxHashSet<_> = Default::default();
             let mut spanned_predicates = FxHashMap::default();
-            for (p, parent_p, impl_def_id, cause) in unsatisfied_predicates
+            for (p, parent_p, cause) in unsatisfied_predicates {
-                .iter()
+                // Extract the predicate span and parent def id of the cause,
-                .filter_map(|(p, parent, c)| c.as_ref().map(|c| (p, parent, c)))
+                // if we have one.
-                .filter_map(|(p, parent, c)| match c.code() {
+                let (item_def_id, cause_span) = match cause.as_ref().map(|cause| cause.code()) {
-                    ObligationCauseCode::ImplDerivedObligation(data)
+                    Some(ObligationCauseCode::ImplDerivedObligation(data)) => {
-                        if matches!(p.kind().skip_binder(), ty::PredicateKind::Clause(_)) =>
+                        (data.impl_or_alias_def_id, data.span)
-                    {
-                        Some((p, parent, data.impl_or_alias_def_id, data))
                     }
-                    _ => None,
+                    Some(
-                })
+                        ObligationCauseCode::ExprBindingObligation(def_id, span, _, _)
-            {
+                        | ObligationCauseCode::BindingObligation(def_id, span),
-                match self.tcx.hir().get_if_local(impl_def_id) {
+                    ) => (*def_id, *span),
+                    _ => continue,
+                };
+
+                // Don't point out the span of `WellFormed` predicates.
+                if !matches!(p.kind().skip_binder(), ty::PredicateKind::Clause(_)) {
+                    continue;
+                };
+
+                match self.tcx.hir().get_if_local(item_def_id) {
                     // Unmet obligation comes from a `derive` macro, point at it once to
                     // avoid multiple span labels pointing at the same place.
                     Some(Node::Item(hir::Item {
@@ -718,7 +725,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 }
                             });
                         for param in generics.params {
-                            if param.span == cause.span && sized_pred {
+                            if param.span == cause_span && sized_pred {
                                 let (sp, sugg) = match param.colon_span {
                                     Some(sp) => (sp.shrink_to_hi(), " ?Sized +"),
                                     None => (param.span.shrink_to_hi(), ": ?Sized"),
@@ -741,9 +748,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             (FxHashSet::default(), FxHashSet::default(), Vec::new())
                         });
                         entry.2.push(p);
-                        if cause.span != *item_span {
+                        if cause_span != *item_span {
-                            entry.0.insert(cause.span);
+                            entry.0.insert(cause_span);
-                            entry.1.insert((cause.span, "unsatisfied trait bound introduced here"));
+                            entry.1.insert((cause_span, "unsatisfied trait bound introduced here"));
                         } else {
                             if let Some(trait_ref) = of_trait {
                                 entry.0.insert(trait_ref.path.span);
@@ -775,9 +782,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let entry = entry.or_insert_with(|| {
                             (FxHashSet::default(), FxHashSet::default(), Vec::new())
                         });
-                        entry.0.insert(cause.span);
+                        entry.0.insert(cause_span);
                         entry.1.insert((ident.span, ""));
-                        entry.1.insert((cause.span, "unsatisfied trait bound introduced here"));
+                        entry.1.insert((cause_span, "unsatisfied trait bound introduced here"));
                         entry.2.push(p);
                     }
                     Some(node) => unreachable!("encountered `{node:?}`"),

compiler/rustc_infer/src/traits/engine.rs

@@ -38,7 +38,7 @@ pub trait TraitEngine<'tcx>: 'tcx {
 
     fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 
-    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>>;
+    fn collect_remaining_errors(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>>;
 
@@ -78,6 +78,6 @@ impl<'tcx, T: ?Sized + TraitEngine<'tcx>> TraitEngineExt<'tcx> for T {
             return errors;
         }
 
-        self.collect_remaining_errors()
+        self.collect_remaining_errors(infcx)
     }
 }

compiler/rustc_infer/src/traits/mod.rs

@@ -128,7 +128,11 @@ pub enum FulfillmentErrorCode<'tcx> {
     CodeProjectionError(MismatchedProjectionTypes<'tcx>),
     CodeSubtypeError(ExpectedFound<Ty<'tcx>>, TypeError<'tcx>), // always comes from a SubtypePredicate
     CodeConstEquateError(ExpectedFound<Const<'tcx>>, TypeError<'tcx>),
-    CodeAmbiguity,
+    CodeAmbiguity {
+        /// Overflow reported from the new solver `-Ztrait-solver=next`, which will
+        /// be reported as an regular error as opposed to a fatal error.
+        overflow: bool,
+    },
 }
 
 impl<'tcx, O> Obligation<'tcx, O> {

compiler/rustc_infer/src/traits/structural_impls.rs

@@ -46,7 +46,8 @@ impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
             super::CodeConstEquateError(ref a, ref b) => {
                 write!(f, "CodeConstEquateError({:?}, {:?})", a, b)
             }
-            super::CodeAmbiguity => write!(f, "Ambiguity"),
+            super::CodeAmbiguity { overflow: false } => write!(f, "Ambiguity"),
+            super::CodeAmbiguity { overflow: true } => write!(f, "Overflow"),
             super::CodeCycle(ref cycle) => write!(f, "Cycle({:?})", cycle),
         }
     }

compiler/rustc_lexer/src/lib.rs

@@ -95,7 +95,7 @@ pub enum TokenKind {
     Literal { kind: LiteralKind, suffix_start: u32 },
 
     /// "'a"
-    Lifetime { starts_with_number: bool, contains_emoji: bool },
+    Lifetime { starts_with_number: bool },
 
     // One-char tokens:
     /// ";"
@@ -632,13 +632,7 @@ impl Cursor<'_> {
             // If the first symbol is valid for identifier, it can be a lifetime.
             // Also check if it's a number for a better error reporting (so '0 will
             // be reported as invalid lifetime and not as unterminated char literal).
-            // We also have to account for potential `'🐱` emojis to avoid reporting
+            is_id_start(self.first()) || self.first().is_digit(10)
-            // it as an unterminated char literal.
-            is_id_start(self.first())
-                || self.first().is_digit(10)
-                // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
-                // 5.0, but Unicode is already newer than this.
-                || unic_emoji_char::is_emoji(self.first())
         };
 
         if !can_be_a_lifetime {
@@ -651,33 +645,16 @@ impl Cursor<'_> {
             return Literal { kind, suffix_start };
         }
 
-        // Either a lifetime or a character literal.
+        // Either a lifetime or a character literal with
+        // length greater than 1.
 
         let starts_with_number = self.first().is_digit(10);
-        let mut contains_emoji = false;
 
-        // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
+        // Skip the literal contents.
-        // 5.0, but Unicode is already newer than this.
+        // First symbol can be a number (which isn't a valid identifier start),
-        if unic_emoji_char::is_emoji(self.first()) {
+        // so skip it without any checks.
-            contains_emoji = true;
+        self.bump();
-        } else {
+        self.eat_while(is_id_continue);
-            // Skip the literal contents.
-            // First symbol can be a number (which isn't a valid identifier start),
-            // so skip it without any checks.
-            self.bump();
-        }
-        self.eat_while(|c| {
-            if is_id_continue(c) {
-                true
-            // FIXME(#108019): `unic-emoji-char` seems to have data tables only up to Unicode
-            // 5.0, but Unicode is already newer than this.
-            } else if unic_emoji_char::is_emoji(c) {
-                contains_emoji = true;
-                true
-            } else {
-                false
-            }
-        });
 
         // Check if after skipping literal contents we've met a closing
         // single quote (which means that user attempted to create a
@@ -687,7 +664,7 @@ impl Cursor<'_> {
             let kind = Char { terminated: true };
             Literal { kind, suffix_start: self.pos_within_token() }
         } else {
-            Lifetime { starts_with_number, contains_emoji }
+            Lifetime { starts_with_number }
         }
     }
 

compiler/rustc_lexer/src/tests.rs

@@ -235,7 +235,7 @@ fn lifetime() {
     check_lexing(
         "'abc",
         expect![[r#"
-            Token { kind: Lifetime { starts_with_number: false, contains_emoji: false }, len: 4 }
+            Token { kind: Lifetime { starts_with_number: false }, len: 4 }
         "#]],
     );
 }

compiler/rustc_parse/src/lexer/mod.rs

@@ -223,21 +223,16 @@ impl<'a> StringReader<'a> {
                     };
                     token::Literal(token::Lit { kind, symbol, suffix })
                 }
-                rustc_lexer::TokenKind::Lifetime { starts_with_number, contains_emoji } => {
+                rustc_lexer::TokenKind::Lifetime { starts_with_number } => {
                     // Include the leading `'` in the real identifier, for macro
                     // expansion purposes. See #12512 for the gory details of why
                     // this is necessary.
                     let lifetime_name = self.str_from(start);
                     if starts_with_number {
                         let span = self.mk_sp(start, self.pos);
-                        let mut diag = self.sess.struct_err("lifetimes or labels cannot start with a number");
+                        let mut diag = self.sess.struct_err("lifetimes cannot start with a number");
                         diag.set_span(span);
                         diag.stash(span, StashKey::LifetimeIsChar);
-                    } else if contains_emoji {
-                        let span = self.mk_sp(start, self.pos);
-                        let mut diag = self.sess.struct_err("lifetimes or labels cannot contain emojis");
-                        diag.set_span(span);
-                        diag.stash(span, StashKey::LifetimeContainsEmoji);
                     }
                     let ident = Symbol::intern(lifetime_name);
                     token::Lifetime(ident)

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -1,6 +1,7 @@
 use std::mem;
 
 use rustc_infer::infer::InferCtxt;
+use rustc_infer::traits::solve::MaybeCause;
 use rustc_infer::traits::Obligation;
 use rustc_infer::traits::{
     query::NoSolution, FulfillmentError, FulfillmentErrorCode, MismatchedProjectionTypes,
@@ -41,13 +42,31 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
         self.obligations.push(obligation);
     }
 
-    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
+    fn collect_remaining_errors(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {
         self.obligations
             .drain(..)
-            .map(|obligation| FulfillmentError {
+            .map(|obligation| {
-                obligation: obligation.clone(),
+                let code =
-                code: FulfillmentErrorCode::CodeAmbiguity,
+                    infcx.probe(|_| match infcx.evaluate_root_goal(obligation.clone().into()) {
-                root_obligation: obligation,
+                        Ok((_, Certainty::Maybe(MaybeCause::Ambiguity), _)) => {
+                            FulfillmentErrorCode::CodeAmbiguity { overflow: false }
+                        }
+                        Ok((_, Certainty::Maybe(MaybeCause::Overflow), _)) => {
+                            FulfillmentErrorCode::CodeAmbiguity { overflow: true }
+                        }
+                        Ok((_, Certainty::Yes, _)) => {
+                            bug!("did not expect successful goal when collecting ambiguity errors")
+                        }
+                        Err(_) => {
+                            bug!("did not expect selection error when collecting ambiguity errors")
+                        }
+                    });
+
+                FulfillmentError {
+                    obligation: obligation.clone(),
+                    code,
+                    root_obligation: obligation,
+                }
             })
             .collect()
     }

compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs

@@ -40,13 +40,16 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         self.obligations.insert(obligation);
     }
 
-    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
+    fn collect_remaining_errors(
+        &mut self,
+        _infcx: &InferCtxt<'tcx>,
+    ) -> Vec<FulfillmentError<'tcx>> {
         // any remaining obligations are errors
         self.obligations
             .iter()
             .map(|obligation| FulfillmentError {
                 obligation: obligation.clone(),
-                code: FulfillmentErrorCode::CodeAmbiguity,
+                code: FulfillmentErrorCode::CodeAmbiguity { overflow: false },
                 // FIXME - does Chalk have a notation of 'root obligation'?
                 // This is just for diagnostics, so it's okay if this is wrong
                 root_obligation: obligation.clone(),

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

@@ -125,6 +125,8 @@ pub trait TypeErrCtxtExt<'tcx> {
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
 
+    fn report_overflow_no_abort(&self, obligation: PredicateObligation<'tcx>) -> ErrorGuaranteed;
+
     fn report_fulfillment_errors(&self, errors: &[FulfillmentError<'tcx>]) -> ErrorGuaranteed;
 
     fn report_overflow_obligation<T>(
@@ -602,6 +604,14 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         );
     }
 
+    fn report_overflow_no_abort(&self, obligation: PredicateObligation<'tcx>) -> ErrorGuaranteed {
+        let obligation = self.resolve_vars_if_possible(obligation);
+        let mut err = self.build_overflow_error(&obligation.predicate, obligation.cause.span, true);
+        self.note_obligation_cause(&mut err, &obligation);
+        self.point_at_returns_when_relevant(&mut err, &obligation);
+        err.emit()
+    }
+
     fn report_selection_error(
         &self,
         mut obligation: PredicateObligation<'tcx>,
@@ -1658,9 +1668,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             FulfillmentErrorCode::CodeProjectionError(ref e) => {
                 self.report_projection_error(&error.obligation, e);
             }
-            FulfillmentErrorCode::CodeAmbiguity => {
+            FulfillmentErrorCode::CodeAmbiguity { overflow: false } => {
                 self.maybe_report_ambiguity(&error.obligation);
             }
+            FulfillmentErrorCode::CodeAmbiguity { overflow: true } => {
+                self.report_overflow_no_abort(error.obligation.clone());
+            }
             FulfillmentErrorCode::CodeSubtypeError(ref expected_found, ref err) => {
                 self.report_mismatched_types(
                     &error.obligation.cause,

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -133,8 +133,15 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
             .register_obligation(PendingPredicateObligation { obligation, stalled_on: vec![] });
     }
 
-    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>> {
+    fn collect_remaining_errors(
-        self.predicates.to_errors(CodeAmbiguity).into_iter().map(to_fulfillment_error).collect()
+        &mut self,
+        _infcx: &InferCtxt<'tcx>,
+    ) -> Vec<FulfillmentError<'tcx>> {
+        self.predicates
+            .to_errors(CodeAmbiguity { overflow: false })
+            .into_iter()
+            .map(to_fulfillment_error)
+            .collect()
     }
 
     fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> {

library/std/src/sync/mpmc/list.rs

@@ -549,6 +549,18 @@ impl<T> Channel<T> {
         let mut head = self.head.index.load(Ordering::Acquire);
         let mut block = self.head.block.load(Ordering::Acquire);
 
+        // If we're going to be dropping messages we need to synchronize with initialization
+        if head >> SHIFT != tail >> SHIFT {
+            // The block can be null here only if a sender is in the process of initializing the
+            // channel while another sender managed to send a message by inserting it into the
+            // semi-initialized channel and advanced the tail.
+            // In that case, just wait until it gets initialized.
+            while block.is_null() {
+                backoff.spin_heavy();
+                block = self.head.block.load(Ordering::Acquire);
+            }
+        }
+
         unsafe {
             // Drop all messages between head and tail and deallocate the heap-allocated blocks.
             while head >> SHIFT != tail >> SHIFT {

src/bootstrap/check.rs

@@ -237,7 +237,7 @@ impl Step for Rustc {
             target,
             cargo_subcommand(builder.kind),
         );
-        rustc_cargo(builder, &mut cargo, target);
+        rustc_cargo(builder, &mut cargo, target, compiler.stage);
 
         // For ./x.py clippy, don't run with --all-targets because
         // linting tests and benchmarks can produce very noisy results
@@ -323,7 +323,7 @@ impl Step for CodegenBackend {
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join(format!("compiler/rustc_codegen_{}/Cargo.toml", backend)));
-        rustc_cargo_env(builder, &mut cargo, target);
+        rustc_cargo_env(builder, &mut cargo, target, compiler.stage);
 
         let msg = if compiler.host == target {
             format!("Checking stage{} {} artifacts ({target})", builder.top_stage, backend)

src/bootstrap/compile.rs

@@ -696,7 +696,7 @@ impl Step for Rustc {
         ));
 
         let mut cargo = builder.cargo(compiler, Mode::Rustc, SourceType::InTree, target, "build");
-        rustc_cargo(builder, &mut cargo, target);
+        rustc_cargo(builder, &mut cargo, target, compiler.stage);
 
         if builder.config.rust_profile_use.is_some()
             && builder.config.rust_profile_generate.is_some()
@@ -813,16 +813,21 @@ impl Step for Rustc {
     }
 }
 
-pub fn rustc_cargo(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection) {
+pub fn rustc_cargo(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection, stage: u32) {
     cargo
         .arg("--features")
         .arg(builder.rustc_features(builder.kind))
         .arg("--manifest-path")
         .arg(builder.src.join("compiler/rustc/Cargo.toml"));
-    rustc_cargo_env(builder, cargo, target);
+    rustc_cargo_env(builder, cargo, target, stage);
 }
 
-pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection) {
+pub fn rustc_cargo_env(
+    builder: &Builder<'_>,
+    cargo: &mut Cargo,
+    target: TargetSelection,
+    stage: u32,
+) {
     // Set some configuration variables picked up by build scripts and
     // the compiler alike
     cargo
@@ -867,83 +872,86 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
         cargo.env("RUSTC_VERIFY_LLVM_IR", "1");
     }
 
-    // Pass down configuration from the LLVM build into the build of
-    // rustc_llvm and rustc_codegen_llvm.
-    //
     // Note that this is disabled if LLVM itself is disabled or we're in a check
     // build. If we are in a check build we still go ahead here presuming we've
     // detected that LLVM is already built and good to go which helps prevent
     // busting caches (e.g. like #71152).
-    if builder.config.llvm_enabled()
+    if builder.config.llvm_enabled() {
-        && (builder.kind != Kind::Check
+        let building_is_expensive = crate::llvm::prebuilt_llvm_config(builder, target).is_err();
-            || crate::llvm::prebuilt_llvm_config(builder, target).is_ok())
+        // `top_stage == stage` might be false for `check --stage 1`, if we are building the stage 1 compiler
-    {
+        let can_skip_build = builder.kind == Kind::Check && builder.top_stage == stage;
-        if builder.is_rust_llvm(target) {
+        let should_skip_build = building_is_expensive && can_skip_build;
-            cargo.env("LLVM_RUSTLLVM", "1");
+        if !should_skip_build {
-        }
+            rustc_llvm_env(builder, cargo, target)
-        let llvm::LlvmResult { llvm_config, .. } = builder.ensure(llvm::Llvm { target });
-        cargo.env("LLVM_CONFIG", &llvm_config);
-        if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
-            cargo.env("CFG_LLVM_ROOT", s);
         }
+    }
+}
 
-        // Some LLVM linker flags (-L and -l) may be needed to link `rustc_llvm`. Its build script
+/// Pass down configuration from the LLVM build into the build of
-        // expects these to be passed via the `LLVM_LINKER_FLAGS` env variable, separated by
+/// rustc_llvm and rustc_codegen_llvm.
-        // whitespace.
+fn rustc_llvm_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection) {
-        //
+    let target_config = builder.config.target_config.get(&target);
-        // For example:
-        // - on windows, when `clang-cl` is used with instrumentation, we need to manually add
-        // clang's runtime library resource directory so that the profiler runtime library can be
-        // found. This is to avoid the linker errors about undefined references to
-        // `__llvm_profile_instrument_memop` when linking `rustc_driver`.
-        let mut llvm_linker_flags = String::new();
-        if builder.config.llvm_profile_generate && target.contains("msvc") {
-            if let Some(ref clang_cl_path) = builder.config.llvm_clang_cl {
-                // Add clang's runtime library directory to the search path
-                let clang_rt_dir = get_clang_cl_resource_dir(clang_cl_path);
-                llvm_linker_flags.push_str(&format!("-L{}", clang_rt_dir.display()));
-            }
-        }
 
-        // The config can also specify its own llvm linker flags.
+    if builder.is_rust_llvm(target) {
-        if let Some(ref s) = builder.config.llvm_ldflags {
+        cargo.env("LLVM_RUSTLLVM", "1");
-            if !llvm_linker_flags.is_empty() {
+    }
-                llvm_linker_flags.push_str(" ");
+    let llvm::LlvmResult { llvm_config, .. } = builder.ensure(llvm::Llvm { target });
-            }
+    cargo.env("LLVM_CONFIG", &llvm_config);
-            llvm_linker_flags.push_str(s);
+    if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
-        }
+        cargo.env("CFG_LLVM_ROOT", s);
+    }
 
-        // Set the linker flags via the env var that `rustc_llvm`'s build script will read.
+    // Some LLVM linker flags (-L and -l) may be needed to link `rustc_llvm`. Its build script
+    // expects these to be passed via the `LLVM_LINKER_FLAGS` env variable, separated by
+    // whitespace.
+    //
+    // For example:
+    // - on windows, when `clang-cl` is used with instrumentation, we need to manually add
+    // clang's runtime library resource directory so that the profiler runtime library can be
+    // found. This is to avoid the linker errors about undefined references to
+    // `__llvm_profile_instrument_memop` when linking `rustc_driver`.
+    let mut llvm_linker_flags = String::new();
+    if builder.config.llvm_profile_generate && target.contains("msvc") {
+        if let Some(ref clang_cl_path) = builder.config.llvm_clang_cl {
+            // Add clang's runtime library directory to the search path
+            let clang_rt_dir = get_clang_cl_resource_dir(clang_cl_path);
+            llvm_linker_flags.push_str(&format!("-L{}", clang_rt_dir.display()));
+        }
+    }
+
+    // The config can also specify its own llvm linker flags.
+    if let Some(ref s) = builder.config.llvm_ldflags {
         if !llvm_linker_flags.is_empty() {
-            cargo.env("LLVM_LINKER_FLAGS", llvm_linker_flags);
+            llvm_linker_flags.push_str(" ");
         }
+        llvm_linker_flags.push_str(s);
+    }
 
-        // Building with a static libstdc++ is only supported on linux right now,
+    // Set the linker flags via the env var that `rustc_llvm`'s build script will read.
-        // not for MSVC or macOS
+    if !llvm_linker_flags.is_empty() {
-        if builder.config.llvm_static_stdcpp
+        cargo.env("LLVM_LINKER_FLAGS", llvm_linker_flags);
-            && !target.contains("freebsd")
+    }
-            && !target.contains("msvc")
+
-            && !target.contains("apple")
+    // Building with a static libstdc++ is only supported on linux right now,
-            && !target.contains("solaris")
+    // not for MSVC or macOS
-        {
+    if builder.config.llvm_static_stdcpp
-            let file = compiler_file(
+        && !target.contains("freebsd")
-                builder,
+        && !target.contains("msvc")
-                builder.cxx(target).unwrap(),
+        && !target.contains("apple")
-                target,
+        && !target.contains("solaris")
-                CLang::Cxx,
+    {
-                "libstdc++.a",
+        let file =
-            );
+            compiler_file(builder, builder.cxx(target).unwrap(), target, CLang::Cxx, "libstdc++.a");
-            cargo.env("LLVM_STATIC_STDCPP", file);
+        cargo.env("LLVM_STATIC_STDCPP", file);
-        }
+    }
-        if builder.llvm_link_shared() {
+    if builder.llvm_link_shared() {
-            cargo.env("LLVM_LINK_SHARED", "1");
+        cargo.env("LLVM_LINK_SHARED", "1");
-        }
+    }
-        if builder.config.llvm_use_libcxx {
+    if builder.config.llvm_use_libcxx {
-            cargo.env("LLVM_USE_LIBCXX", "1");
+        cargo.env("LLVM_USE_LIBCXX", "1");
-        }
+    }
-        if builder.config.llvm_optimize && !builder.config.llvm_release_debuginfo {
+    if builder.config.llvm_optimize && !builder.config.llvm_release_debuginfo {
-            cargo.env("LLVM_NDEBUG", "1");
+        cargo.env("LLVM_NDEBUG", "1");
-        }
     }
 }
 
@@ -1090,7 +1098,7 @@ impl Step for CodegenBackend {
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join(format!("compiler/rustc_codegen_{}/Cargo.toml", backend)));
-        rustc_cargo_env(builder, &mut cargo, target);
+        rustc_cargo_env(builder, &mut cargo, target, compiler.stage);
 
         let tmp_stamp = out_dir.join(".tmp.stamp");
 

src/bootstrap/doc.rs

@@ -696,7 +696,7 @@ impl Step for Rustc {
         cargo.rustdocflag("-Znormalize-docs");
         cargo.rustdocflag("--show-type-layout");
         cargo.rustdocflag("--generate-link-to-definition");
-        compile::rustc_cargo(builder, &mut cargo, target);
+        compile::rustc_cargo(builder, &mut cargo, target, compiler.stage);
         cargo.arg("-Zunstable-options");
         cargo.arg("-Zskip-rustdoc-fingerprint");
 

src/bootstrap/test.rs

@@ -1064,6 +1064,8 @@ impl Step for RustdocGUI {
                     cargo.env("RUSTDOCFLAGS", "-Zunstable-options --generate-link-to-definition");
                 } else if entry.file_name() == "scrape_examples" {
                     cargo.arg("-Zrustdoc-scrape-examples");
+                } else if entry.file_name() == "extend_css" {
+                    cargo.env("RUSTDOCFLAGS", &format!("--extend-css extra.css"));
                 }
                 builder.run(&mut cargo);
             }
@@ -2146,7 +2148,7 @@ impl Step for Crate {
                 compile::std_cargo(builder, target, compiler.stage, &mut cargo);
             }
             Mode::Rustc => {
-                compile::rustc_cargo(builder, &mut cargo, target);
+                compile::rustc_cargo(builder, &mut cargo, target, compiler.stage);
             }
             _ => panic!("can only test libraries"),
         };

src/doc/rustdoc/src/command-line-arguments.md

@@ -320,10 +320,7 @@ $ rustdoc src/lib.rs --extend-css extra.css
 ```
 
 With this flag, the contents of the files you pass are included at the bottom
-of Rustdoc's `theme.css` file.
+of the `theme.css` file.
-
-While this flag is stable, the contents of `theme.css` are not, so be careful!
-Updates may break your theme extensions.
 
 ## `--sysroot`: override the system root
 

src/librustdoc/config.rs

@@ -6,7 +6,6 @@ use std::path::PathBuf;
 use std::str::FromStr;
 
 use rustc_data_structures::fx::FxHashMap;
-use rustc_driver::print_flag_list;
 use rustc_session::config::{
     self, parse_crate_types_from_list, parse_externs, parse_target_triple, CrateType,
 };
@@ -328,14 +327,7 @@ impl Options {
             return Err(0);
         }
 
-        let z_flags = matches.opt_strs("Z");
+        if rustc_driver::describe_flag_categories(&matches) {
-        if z_flags.iter().any(|x| *x == "help") {
-            print_flag_list("-Z", config::Z_OPTIONS);
-            return Err(0);
-        }
-        let c_flags = matches.opt_strs("C");
-        if c_flags.iter().any(|x| *x == "help") {
-            print_flag_list("-C", config::CG_OPTIONS);
             return Err(0);
         }
 

src/librustdoc/doctest.rs

@@ -398,6 +398,8 @@ fn run_test(
     compiler.stdin(Stdio::piped());
     compiler.stderr(Stdio::piped());
 
+    debug!("compiler invocation for doctest: {:?}", compiler);
+
     let mut child = compiler.spawn().expect("Failed to spawn rustc process");
     {
         let stdin = child.stdin.as_mut().expect("Failed to open stdin");

src/librustdoc/html/templates/page.html

@@ -64,7 +64,7 @@
     </noscript> {# #}
     {% if layout.css_file_extension.is_some() %}
         <link rel="stylesheet" {#+ #}
-            href="{{static_root_path|safe}}theme{{page.resource_suffix}}.css"> {# #}
+            href="{{page.root_path|safe}}theme{{page.resource_suffix}}.css"> {# #}
     {% endif %}
     {% if !layout.favicon.is_empty() %}
         <link rel="icon" href="{{layout.favicon}}"> {# #}

tests/run-make/rustdoc-shared-flags/Makefile

@@ -0,0 +1,18 @@
+include ../tools.mk
+
+all: z_help c_help list_passes
+
+c_help:
+	$(RUSTC) -C help > $(TMPDIR)/rustc.c_help.txt
+	$(RUSTDOC) -C help > $(TMPDIR)/rustdoc.c_help.txt
+	$(DIFF) $(TMPDIR)/rustc.c_help.txt $(TMPDIR)/rustdoc.c_help.txt
+
+z_help:
+	$(RUSTC) -Z help > $(TMPDIR)/rustc.z_help.txt
+	$(RUSTDOC) -Z help > $(TMPDIR)/rustdoc.z_help.txt
+	$(DIFF) $(TMPDIR)/rustc.z_help.txt $(TMPDIR)/rustdoc.z_help.txt
+
+list_passes:
+	$(RUSTC) -C passes=list > $(TMPDIR)/rustc.passes.txt
+	$(RUSTDOC) -C passes=list > $(TMPDIR)/rustdoc.passes.txt
+	$(DIFF) $(TMPDIR)/rustc.passes.txt $(TMPDIR)/rustdoc.passes.txt

tests/rustdoc-gui/extend-css.goml

@@ -0,0 +1,5 @@
+// Test to ensure that the `--extend-css` option is working as expected.
+go-to: "file://" + |DOC_PATH| + "/extend_css/index.html"
+show-text: true
+// The text from the `.extend` element should be red.
+assert-css: (".extend", {"color": "rgb(255, 0, 0)"})

tests/rustdoc-gui/search-filter.goml

@@ -16,6 +16,7 @@ press-key: "ArrowDown"
 press-key: "ArrowDown"
 press-key: "ArrowDown"
 press-key: "ArrowDown"
+press-key: "ArrowDown"
 press-key: "Enter"
 // Waiting for the search results to appear...
 wait-for: "#search-tabs"
@@ -41,6 +42,7 @@ press-key: "ArrowUp"
 press-key: "ArrowUp"
 press-key: "ArrowUp"
 press-key: "ArrowUp"
+press-key: "ArrowUp"
 press-key: "Enter"
 // Waiting for the search results to appear...
 wait-for: "#search-tabs"

tests/rustdoc-gui/sidebar-source-code.goml

@@ -73,7 +73,7 @@ assert: "//*[@class='dir-entry' and @open]/*[text()='sub_mod']"
 // Only "another_folder" should be "open" in "lib2".
 assert: "//*[@class='dir-entry' and not(@open)]/*[text()='another_mod']"
 // All other trees should be collapsed.
-assert-count: ("//*[@id='source-sidebar']/details[not(text()='lib2') and not(@open)]", 8)
+assert-count: ("//*[@id='source-sidebar']/details[not(text()='lib2') and not(@open)]", 9)
 
 // We now switch to mobile mode.
 set-window-size: (600, 600)

tests/rustdoc-gui/source-code-page.goml

@@ -102,7 +102,7 @@ assert: ".source-sidebar-expanded"
 
 // We check that the first entry of the sidebar is collapsed
 assert-property: ("#source-sidebar details:first-of-type", {"open": "false"})
-assert-text: ("#source-sidebar details:first-of-type > summary", "http")
+assert-text: ("#source-sidebar details:first-of-type > summary", "extend_css")
 // We now click on it.
 click: "#source-sidebar details:first-of-type > summary"
 assert-property: ("#source-sidebar details:first-of-type", {"open": "true"})

tests/rustdoc-gui/src/extend_css/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "extend_css"
+version = "0.1.0"

tests/rustdoc-gui/src/extend_css/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "extend_css"
+version = "0.1.0"
+edition = "2018"
+
+[lib]
+path = "lib.rs"

tests/rustdoc-gui/src/extend_css/extra.css

@@ -0,0 +1,3 @@
+.extend {
+    color: red !important;
+}

tests/rustdoc-gui/src/extend_css/lib.rs

@@ -0,0 +1 @@
+//! <div class="extend">text in red</div>

tests/rustdoc-ui/c-help.rs

@@ -1,6 +0,0 @@
-// check-pass
-// compile-flags: -Chelp
-// check-stdout
-// regex-error-pattern: -C\s+incremental
-
-pub struct Foo;

tests/rustdoc-ui/c-help.stdout

@@ -1,51 +0,0 @@
-    -C                       ar=val -- this option is deprecated and does nothing
-    -C               code-model=val -- choose the code model to use (`rustc --print code-models` for details)
-    -C            codegen-units=val -- divide crate into N units to optimize in parallel
-    -C       control-flow-guard=val -- use Windows Control Flow Guard (default: no)
-    -C         debug-assertions=val -- explicitly enable the `cfg(debug_assertions)` directive
-    -C                debuginfo=val -- debug info emission level (0-2, none, line-directives-only, line-tables-only, limited, or full; default: 0)
-    -C default-linker-libraries=val -- allow the linker to link its default libraries (default: no)
-    -C            embed-bitcode=val -- emit bitcode in rlibs (default: yes)
-    -C           extra-filename=val -- extra data to put in each output filename
-    -C     force-frame-pointers=val -- force use of the frame pointers
-    -C      force-unwind-tables=val -- force use of unwind tables
-    -C              incremental=val -- enable incremental compilation
-    -C         inline-threshold=val -- set the threshold for inlining a function
-    -C      instrument-coverage=val -- instrument the generated code to support LLVM source-based code coverage reports (note, the compiler build config must include `profiler = true`); implies `-C symbol-mangling-version=v0`. Optional values are:
-        `=all` (implicit value)
-        `=except-unused-generics`
-        `=except-unused-functions`
-        `=off` (default)
-    -C                 link-arg=val -- a single extra argument to append to the linker invocation (can be used several times)
-    -C                link-args=val -- extra arguments to append to the linker invocation (space separated)
-    -C           link-dead-code=val -- keep dead code at link time (useful for code coverage) (default: no)
-    -C      link-self-contained=val -- control whether to link Rust provided C objects/libraries or rely
-        on C toolchain installed in the system
-    -C                   linker=val -- system linker to link outputs with
-    -C            linker-flavor=val -- linker flavor
-    -C        linker-plugin-lto=val -- generate build artifacts that are compatible with linker-based LTO
-    -C                llvm-args=val -- a list of arguments to pass to LLVM (space separated)
-    -C                      lto=val -- perform LLVM link-time optimizations
-    -C                 metadata=val -- metadata to mangle symbol names with
-    -C    no-prepopulate-passes=val -- give an empty list of passes to the pass manager
-    -C               no-redzone=val -- disable the use of the redzone
-    -C           no-stack-check=val -- this option is deprecated and does nothing
-    -C       no-vectorize-loops=val -- disable loop vectorization optimization passes
-    -C         no-vectorize-slp=val -- disable LLVM's SLP vectorization pass
-    -C                opt-level=val -- optimization level (0-3, s, or z; default: 0)
-    -C          overflow-checks=val -- use overflow checks for integer arithmetic
-    -C                    panic=val -- panic strategy to compile crate with
-    -C                   passes=val -- a list of extra LLVM passes to run (space separated)
-    -C           prefer-dynamic=val -- prefer dynamic linking to static linking (default: no)
-    -C         profile-generate=val -- compile the program with profiling instrumentation
-    -C              profile-use=val -- use the given `.profdata` file for profile-guided optimization
-    -C         relocation-model=val -- control generation of position-independent code (PIC) (`rustc --print relocation-models` for details)
-    -C                   remark=val -- print remarks for these optimization passes (space separated, or "all")
-    -C                    rpath=val -- set rpath values in libs/exes (default: no)
-    -C               save-temps=val -- save all temporary output files during compilation (default: no)
-    -C               soft-float=val -- use soft float ABI (*eabihf targets only) (default: no)
-    -C          split-debuginfo=val -- how to handle split-debuginfo, a platform-specific option
-    -C                    strip=val -- tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)
-    -C  symbol-mangling-version=val -- which mangling version to use for symbol names ('legacy' (default) or 'v0')
-    -C               target-cpu=val -- select target processor (`rustc --print target-cpus` for details)
-    -C           target-feature=val -- target specific attributes. (`rustc --print target-features` for details). This feature is unsafe.

tests/rustdoc-ui/z-help.rs

@@ -1,6 +0,0 @@
-// check-pass
-// compile-flags: -Zhelp
-// check-stdout
-// regex-error-pattern: -Z\s+self-profile
-
-pub struct Foo;

tests/rustdoc-ui/z-help.stdout

@@ -1,220 +0,0 @@
-    -Z                        allow-features=val -- only allow the listed language features to be enabled in code (comma separated)
-    -Z                     always-encode-mir=val -- encode MIR of all functions into the crate metadata (default: no)
-    -Z                          asm-comments=val -- generate comments into the assembly (may change behavior) (default: no)
-    -Z                     assert-incr-state=val -- assert that the incremental cache is in given state: either `loaded` or `not-loaded`.
-    -Z             assume-incomplete-release=val -- make cfg(version) treat the current version as incomplete (default: no)
-    -Z                    binary-dep-depinfo=val -- include artifacts (sysroot, crate dependencies) used during compilation in dep-info (default: no)
-    -Z                           box-noalias=val -- emit noalias metadata for box (default: yes)
-    -Z                     branch-protection=val -- set options for branch target identification and pointer authentication on AArch64
-    -Z                         cf-protection=val -- instrument control-flow architecture protection
-    -Z             cgu-partitioning-strategy=val -- the codegen unit partitioning strategy to use
-    -Z                       codegen-backend=val -- the backend to use
-    -Z                           combine-cgu=val -- combine CGUs into a single one
-    -Z                            crate-attr=val -- inject the given attribute in the crate
-    -Z              debug-info-for-profiling=val -- emit discriminators and other data necessary for AutoFDO
-    -Z                          debug-macros=val -- emit line numbers debug info inside macros (default: no)
-    -Z               deduplicate-diagnostics=val -- deduplicate identical diagnostics (default: yes)
-    -Z                dep-info-omit-d-target=val -- in dep-info output, omit targets for tracking dependencies of the dep-info files themselves (default: no)
-    -Z                             dep-tasks=val -- print tasks that execute and the color their dep node gets (requires debug build) (default: no)
-    -Z                      diagnostic-width=val -- set the current output width for diagnostic truncation
-    -Z                               dlltool=val -- import library generation tool (windows-gnu only)
-    -Z               dont-buffer-diagnostics=val -- emit diagnostics rather than buffering (breaks NLL error downgrading, sorting) (default: no)
-    -Z                         drop-tracking=val -- enables drop tracking in generators (default: no)
-    -Z                     drop-tracking-mir=val -- enables drop tracking on MIR in generators (default: no)
-    -Z                      dual-proc-macros=val -- load proc macros for both target and host, but only link to the target (default: no)
-    -Z                        dump-dep-graph=val -- dump the dependency graph to $RUST_DEP_GRAPH (default: /tmp/dep_graph.gv) (default: no)
-    -Z                dump-drop-tracking-cfg=val -- dump drop-tracking control-flow graph as a `.dot` file (default: no)
-    -Z                              dump-mir=val -- dump MIR state to file.
-        `val` is used to select which passes and functions to dump. For example:
-        `all` matches all passes and functions,
-        `foo` matches all passes for functions whose name contains 'foo',
-        `foo & ConstProp` only the 'ConstProp' pass for function names containing 'foo',
-        `foo | bar` all passes for function names containing 'foo' or 'bar'.
-    -Z                     dump-mir-dataflow=val -- in addition to `.mir` files, create graphviz `.dot` files with dataflow results (default: no)
-    -Z                          dump-mir-dir=val -- the directory the MIR is dumped into (default: `mir_dump`)
-    -Z          dump-mir-exclude-pass-number=val -- exclude the pass number when dumping MIR (used in tests) (default: no)
-    -Z                     dump-mir-graphviz=val -- in addition to `.mir` files, create graphviz `.dot` files (and with `-Z instrument-coverage`, also create a `.dot` file for the MIR-derived coverage graph) (default: no)
-    -Z                     dump-mir-spanview=val -- in addition to `.mir` files, create `.html` files to view spans for all `statement`s (including terminators), only `terminator` spans, or computed `block` spans (one span encompassing a block's terminator and all statements). If `-Z instrument-coverage` is also enabled, create an additional `.html` file showing the computed coverage spans.
-    -Z                       dump-mono-stats=val -- output statistics about monomorphization collection
-    -Z                dump-mono-stats-format=val -- the format to use for -Z dump-mono-stats (`markdown` (default) or `json`)
-    -Z                         dwarf-version=val -- version of DWARF debug information to emit (default: 2 or 4, depending on platform)
-    -Z                             dylib-lto=val -- enables LTO for dylib crate type
-    -Z                      emit-stack-sizes=val -- emit a section containing stack size metadata (default: no)
-    -Z                         emit-thin-lto=val -- emit the bc module with thin LTO info (default: yes)
-    -Z             export-executable-symbols=val -- export symbols from executables, as if they were dynamic libraries
-    -Z                 extra-const-ub-checks=val -- turns on more checks to detect const UB, which can be slow (default: no)
-    -Z                           fewer-names=val -- reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) (default: no)
-    -Z                   flatten-format-args=val -- flatten nested format_args!() and literals into a simplified format_args!() call (default: no)
-    -Z            force-unstable-if-unmarked=val -- force all crates to be `rustc_private` unstable (default: no)
-    -Z                                  fuel=val -- set the optimization fuel quota for a crate
-    -Z                     function-sections=val -- whether each function should go in its own section
-    -Z                  future-incompat-test=val -- forces all lints to be future incompatible, used for internal testing (default: no)
-    -Z                                gcc-ld=val -- implementation of ld used by cc
-    -Z                    graphviz-dark-mode=val -- use dark-themed colors in graphviz output (default: no)
-    -Z                         graphviz-font=val -- use the given `fontname` in graphviz output; can be overridden by setting environment variable `RUSTC_GRAPHVIZ_FONT` (default: `Courier, monospace`)
-    -Z                             hir-stats=val -- print some statistics about AST and HIR (default: no)
-    -Z              human-readable-cgu-names=val -- generate human-readable, predictable names for codegen units (default: no)
-    -Z                      identify-regions=val -- display unnamed regions as `'<id>`, using a non-ident unique id (default: no)
-    -Z              incremental-ignore-spans=val -- ignore spans during ICH computation -- used for testing (default: no)
-    -Z                      incremental-info=val -- print high-level information about incremental reuse (or the lack thereof) (default: no)
-    -Z            incremental-relative-spans=val -- hash spans relative to their parent item for incr. comp. (default: no)
-    -Z                incremental-verify-ich=val -- verify incr. comp. hashes of green query instances (default: no)
-    -Z                    inline-in-all-cgus=val -- control whether `#[inline]` functions are in all CGUs
-    -Z                           inline-llvm=val -- enable LLVM inlining (default: yes)
-    -Z                            inline-mir=val -- enable MIR inlining (default: no)
-    -Z             inline-mir-hint-threshold=val -- inlining threshold for functions with inline hint (default: 100)
-    -Z                  inline-mir-threshold=val -- a default MIR inlining threshold (default: 50)
-    -Z                           input-stats=val -- gather statistics about the input (default: no)
-    -Z                   instrument-coverage=val -- instrument the generated code to support LLVM source-based code coverage reports (note, the compiler build config must include `profiler = true`); implies `-C symbol-mangling-version=v0`. Optional values are:
-        `=all` (implicit value)
-        `=except-unused-generics`
-        `=except-unused-functions`
-        `=off` (default)
-    -Z                     instrument-mcount=val -- insert function instrument code for mcount-based tracing (default: no)
-    -Z                       instrument-xray=val -- insert function instrument code for XRay-based tracing (default: no)
-         Optional extra settings:
-         `=always`
-         `=never`
-         `=ignore-loops`
-         `=instruction-threshold=N`
-         `=skip-entry`
-         `=skip-exit`
-         Multiple options can be combined with commas.
-    -Z                     keep-hygiene-data=val -- keep hygiene data after analysis (default: no)
-    -Z                           layout-seed=val -- seed layout randomization
-    -Z                       link-directives=val -- honor #[link] directives in the compiled crate (default: yes)
-    -Z                 link-native-libraries=val -- link native libraries in the linker invocation (default: yes)
-    -Z                             link-only=val -- link the `.rlink` file generated by `-Z no-link` (default: no)
-    -Z                          llvm-plugins=val -- a list LLVM plugins to enable (space separated)
-    -Z                       llvm-time-trace=val -- generate JSON tracing data file from LLVM data (default: no)
-    -Z                       location-detail=val -- what location details should be tracked when using caller_location, either `none`, or a comma separated list of location details, for which valid options are `file`, `line`, and `column` (default: `file,line,column`)
-    -Z lower-impl-trait-in-trait-to-assoc-ty=val -- modify the lowering strategy for `impl Trait` in traits so that they are lowered to generic associated types
-    -Z                                    ls=val -- list the symbols defined by a library crate (default: no)
-    -Z                       macro-backtrace=val -- show macro backtraces (default: no)
-    -Z           maximal-hir-to-mir-coverage=val -- save as much information as possible about the correspondence between MIR and HIR as source scopes (default: no)
-    -Z                       merge-functions=val -- control the operation of the MergeFunctions LLVM pass, taking the same values as the target option of the same name
-    -Z                            meta-stats=val -- gather metadata statistics (default: no)
-    -Z                        mir-emit-retag=val -- emit Retagging MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 (default: no)
-    -Z                     mir-enable-passes=val -- use like `-Zmir-enable-passes=+DestProp,-InstCombine`. Forces the specified passes to be enabled, overriding all other checks. Passes that are not specified are enabled or disabled by other flags as usual.
-    -Z                         mir-opt-level=val -- MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)
-    -Z      mir-pretty-relative-line-numbers=val -- use line numbers relative to the function in mir pretty printing
-    -Z                       move-size-limit=val -- the size at which the `large_assignments` lint starts to be emitted
-    -Z                       mutable-noalias=val -- emit noalias metadata for mutable references (default: yes)
-    -Z                             nll-facts=val -- dump facts from NLL analysis into side files (default: no)
-    -Z                         nll-facts-dir=val -- the directory the NLL facts are dumped into (default: `nll-facts`)
-    -Z                           no-analysis=val -- parse and expand the source, but run no analysis
-    -Z                            no-codegen=val -- run all passes except codegen; no output
-    -Z            no-generate-arange-section=val -- omit DWARF address ranges that give faster lookups
-    -Z                        no-jump-tables=val -- disable the jump tables and lookup tables that can be generated from a switch case lowering
-    -Z                         no-leak-check=val -- disable the 'leak check' for subtyping; unsound, but useful for tests
-    -Z                               no-link=val -- compile without linking
-    -Z                      no-parallel-llvm=val -- run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)
-    -Z                   no-profiler-runtime=val -- prevent automatic injection of the profiler_builtins crate
-    -Z               no-unique-section-names=val -- do not use unique names for text and data sections when -Z function-sections is used
-    -Z                        normalize-docs=val -- normalize associated items in rustdoc when generating documentation
-    -Z                                   oom=val -- panic strategy for out-of-memory handling
-    -Z                osx-rpath-install-name=val -- pass `-install_name @rpath/...` to the macOS linker (default: no)
-    -Z                   packed-bundled-libs=val -- change rlib format to store native libraries as archives
-    -Z                     panic-abort-tests=val -- support compiling tests with panic=abort (default: no)
-    -Z                         panic-in-drop=val -- panic strategy for panics in drops
-    -Z                            parse-only=val -- parse only; do not compile, assemble, or link (default: no)
-    -Z                            perf-stats=val -- print some performance-related statistics (default: no)
-    -Z                                   plt=val -- whether to use the PLT when calling into shared libraries;
-        only has effect for PIC code on systems with ELF binaries
-        (default: PLT is disabled if full relro is enabled)
-    -Z                              polonius=val -- enable polonius-based borrow-checker (default: no)
-    -Z                          polymorphize=val -- perform polymorphization analysis
-    -Z                          pre-link-arg=val -- a single extra argument to prepend the linker invocation (can be used several times)
-    -Z                         pre-link-args=val -- extra arguments to prepend to the linker invocation (space separated)
-    -Z         precise-enum-drop-elaboration=val -- use a more precise version of drop elaboration for matches on enums (default: yes). This results in better codegen, but has caused miscompilations on some tier 2 platforms. See #77382 and #74551.
-    -Z                            print-fuel=val -- make rustc print the total optimization fuel used by a crate
-    -Z                     print-llvm-passes=val -- print the LLVM optimization passes being run (default: no)
-    -Z                      print-mono-items=val -- print the result of the monomorphization collection pass
-    -Z                      print-type-sizes=val -- print layout information for each type encountered (default: no)
-    -Z                  proc-macro-backtrace=val -- show backtraces for panics during proc-macro execution (default: no)
-    -Z         proc-macro-execution-strategy=val -- how to run proc-macro code (default: same-thread)
-    -Z                               profile=val -- insert profiling code (default: no)
-    -Z                      profile-closures=val -- profile size of closures
-    -Z                          profile-emit=val -- file path to emit profiling data at runtime when using 'profile' (default based on relative source path)
-    -Z                    profile-sample-use=val -- use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)
-    -Z                      profiler-runtime=val -- name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)
-    -Z                       query-dep-graph=val -- enable queries of the dependency graph for regression testing (default: no)
-    -Z                      randomize-layout=val -- randomize the layout of types (default: no)
-    -Z                 relax-elf-relocations=val -- whether ELF relocations can be relaxed
-    -Z                           relro-level=val -- choose which RELRO level to use
-    -Z                      remap-cwd-prefix=val -- remap paths under the current working directory to this path prefix
-    -Z                   report-delayed-bugs=val -- immediately print bugs registered with `delay_span_bug` (default: no)
-    -Z                             sanitizer=val -- use a sanitizer
-    -Z        sanitizer-memory-track-origins=val -- enable origins tracking in MemorySanitizer
-    -Z                     sanitizer-recover=val -- enable recovery for selected sanitizers
-    -Z                saturating-float-casts=val -- make float->int casts UB-free: numbers outside the integer type's range are clipped to the max/min integer respectively, and NaN is mapped to 0 (default: yes)
-    -Z                          self-profile=val -- run the self profiler and output the raw event data
-    -Z                  self-profile-counter=val -- counter used by the self profiler (default: `wall-time`), one of:
-        `wall-time` (monotonic clock, i.e. `std::time::Instant`)
-        `instructions:u` (retired instructions, userspace-only)
-        `instructions-minus-irqs:u` (subtracting hardware interrupt counts for extra accuracy)
-    -Z                   self-profile-events=val -- specify the events recorded by the self profiler;
-        for example: `-Z self-profile-events=default,query-keys`
-        all options: none, all, default, generic-activity, query-provider, query-cache-hit
-                     query-blocked, incr-cache-load, incr-result-hashing, query-keys, function-args, args, llvm, artifact-sizes
-    -Z                        share-generics=val -- make the current crate share its generic instantiations
-    -Z                             show-span=val -- show spans for compiler debugging (expr|pat|ty)
-    -Z       simulate-remapped-rust-src-base=val -- simulate the effect of remap-debuginfo = true at bootstrapping by remapping path to rust's source base directory. only meant for testing purposes
-    -Z                            span-debug=val -- forward proc_macro::Span's `Debug` impl to `Span`
-    -Z                     span-free-formats=val -- exclude spans when debug-printing compiler state (default: no)
-    -Z                  split-dwarf-inlining=val -- provide minimal debug info in the object/executable to facilitate online symbolication/stack traces in the absence of .dwo/.dwp files when using Split DWARF
-    -Z                      split-dwarf-kind=val -- split dwarf variant (only if -Csplit-debuginfo is enabled and on relevant platform)
-        (default: `split`)
-
-        `split`: sections which do not require relocation are written into a DWARF object (`.dwo`)
-                 file which is ignored by the linker
-        `single`: sections which do not require relocation are written into object file but ignored
-                  by the linker
-    -Z                    src-hash-algorithm=val -- hash algorithm of source files in debug info (`md5`, `sha1`, or `sha256`)
-    -Z                       stack-protector=val -- control stack smash protection strategy (`rustc --print stack-protector-strategies` for details)
-    -Z                    strict-init-checks=val -- control if mem::uninitialized and mem::zeroed panic on more UB
-    -Z                                 strip=val -- tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)
-    -Z               symbol-mangling-version=val -- which mangling version to use for symbol names ('legacy' (default) or 'v0')
-    -Z                                 teach=val -- show extended diagnostic help (default: no)
-    -Z                             temps-dir=val -- the directory the intermediate files are written to
-    -Z                         terminal-urls=val -- use the OSC 8 hyperlink terminal specification to print hyperlinks in the compiler output
-    -Z                               thinlto=val -- enable ThinLTO when possible
-    -Z                         thir-unsafeck=val -- use the THIR unsafety checker (default: no)
-    -Z                               threads=val -- use a thread pool with N threads
-    -Z                      time-llvm-passes=val -- measure time of each LLVM pass (default: no)
-    -Z                           time-passes=val -- measure time of each rustc pass (default: no)
-    -Z                    time-passes-format=val -- the format to use for -Z time-passes (`text` (default) or `json`)
-    -Z                 tiny-const-eval-limit=val -- sets a tiny, non-configurable limit for const eval; useful for compiler tests
-    -Z                             tls-model=val -- choose the TLS model to use (`rustc --print tls-models` for details)
-    -Z                          trace-macros=val -- for every macro invocation, print its name and arguments (default: no)
-    -Z                     track-diagnostics=val -- tracks where in rustc a diagnostic was emitted
-    -Z                          trait-solver=val -- specify the trait solver mode used by rustc (default: classic)
-    -Z              translate-additional-ftl=val -- additional fluent translation to preferentially use (for testing translation)
-    -Z      translate-directionality-markers=val -- emit directionality isolation markers in translated diagnostics
-    -Z                        translate-lang=val -- language identifier for diagnostic output
-    -Z translate-remapped-path-to-local-path=val -- translate remapped paths into local paths when possible (default: yes)
-    -Z                      trap-unreachable=val -- generate trap instructions for unreachable intrinsics (default: use target setting, usually yes)
-    -Z                      treat-err-as-bug=val -- treat error number `val` that occurs as bug
-    -Z                 trim-diagnostic-paths=val -- in diagnostics, use heuristics to shorten paths referring to items
-    -Z                              tune-cpu=val -- select processor to schedule for (`rustc --print target-cpus` for details)
-    -Z                            ui-testing=val -- emit compiler diagnostics in a form suitable for UI testing (default: no)
-    -Z          uninit-const-chunk-threshold=val -- allow generating const initializers with mixed init/uninit chunks, and set the maximum number of chunks for which this is allowed (default: 16)
-    -Z        unleash-the-miri-inside-of-you=val -- take the brakes off const evaluation. NOTE: this is unsound (default: no)
-    -Z                              unpretty=val -- present the input source, unstable (and less-pretty) variants;
-        `normal`, `identified`,
-        `expanded`, `expanded,identified`,
-        `expanded,hygiene` (with internal representations),
-        `ast-tree` (raw AST before expansion),
-        `ast-tree,expanded` (raw AST after expansion),
-        `hir` (the HIR), `hir,identified`,
-        `hir,typed` (HIR with types for each node),
-        `hir-tree` (dump the raw HIR),
-        `mir` (the MIR), or `mir-cfg` (graphviz formatted MIR)
-    -Z                      unsound-mir-opts=val -- enable unsound and buggy MIR optimizations (default: no)
-    -Z                      unstable-options=val -- adds unstable command line options to rustc interface (default: no)
-    -Z                     use-ctors-section=val -- use legacy .ctors section for initializers rather than .init_array
-    -Z                          validate-mir=val -- validate MIR after each transformation
-    -Z                               verbose=val -- in general, enable more debug printouts (default: no)
-    -Z                        verify-llvm-ir=val -- verify LLVM IR (default: no)
-    -Z          virtual-function-elimination=val -- enables dead virtual function elimination optimization. Requires `-Clto[=[fat,yes]]`
-    -Z                       wasi-exec-model=val -- whether to build a wasi command or reactor

tests/ui/higher-rank-trait-bounds/issue-95230.new.stderr

@@ -1,9 +1,10 @@
-error[E0282]: type annotations needed
+error[E0275]: overflow evaluating the requirement `for<'a> &'a mut Bar well-formed`
   --> $DIR/issue-95230.rs:9:13
    |
 LL |     for<'a> &'a mut Self:;
-   |             ^^^^^^^^^^^^ cannot infer type for mutable reference `&'a mut Bar`
+   |             ^^^^^^^^^^^^
    |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_95230`)
 note: required by a bound in `Bar`
   --> $DIR/issue-95230.rs:9:13
    |
@@ -15,4 +16,4 @@ LL |     for<'a> &'a mut Self:;
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0275`.

tests/ui/lexer/issue-108019-bad-emoji-recovery.rs

@@ -1,45 +0,0 @@
-#![allow(unused_labels)]
-
-// FIXME(#108019): outdated Unicode table
-// fn foo() {
-//     '🥺 loop {
-//         break
-//     }
-// }
-
-fn bar() {
-    '🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot contain emojis
-        break
-    }
-}
-
-fn qux() {
-    'a🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot contain emojis
-        break
-    }
-}
-
-fn quux() {
-    '1🐱 loop {
-    //~^ ERROR labeled expression must be followed by `:`
-    //~| ERROR lifetimes or labels cannot start with a number
-        break
-    }
-}
-
-fn x<'🐱>() -> &'🐱 () {
-    //~^ ERROR lifetimes or labels cannot contain emojis
-    //~| ERROR lifetimes or labels cannot contain emojis
-    &()
-}
-
-fn y() {
-    'a🐱: loop {}
-    //~^ ERROR lifetimes or labels cannot contain emojis
-}
-
-fn main() {}

tests/ui/lexer/issue-108019-bad-emoji-recovery.stderr

@@ -1,86 +0,0 @@
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:11:5
-   |
-LL |       '🐱 loop {
-   |       ^--- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:19:5
-   |
-LL |       'a🐱 loop {
-   |       ^---- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: labeled expression must be followed by `:`
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:27:5
-   |
-LL |       '1🐱 loop {
-   |       ^---- help: add `:` after the label
-   |       |
-   |  _____the label
-   | |
-LL | |
-LL | |
-LL | |         break
-LL | |     }
-   | |_____^
-   |
-   = note: labels are used before loops and blocks, allowing e.g., `break 'label` to them
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:11:5
-   |
-LL |     '🐱 loop {
-   |     ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:19:5
-   |
-LL |     'a🐱 loop {
-   |     ^^^^
-
-error: lifetimes or labels cannot start with a number
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:27:5
-   |
-LL |     '1🐱 loop {
-   |     ^^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:34:6
-   |
-LL | fn x<'🐱>() -> &'🐱 () {
-   |      ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:34:16
-   |
-LL | fn x<'🐱>() -> &'🐱 () {
-   |                 ^^^
-
-error: lifetimes or labels cannot contain emojis
-  --> $DIR/issue-108019-bad-emoji-recovery.rs:41:5
-   |
-LL |     'a🐱: loop {}
-   |     ^^^^
-
-error: aborting due to 9 previous errors
-

tests/ui/methods/inherent-bound-in-probe.rs

@@ -0,0 +1,49 @@
+// normalize-stderr-test: "long-type-\d+" -> "long-type-hash"
+
+// Fixes #110131
+//
+// The issue is that we were constructing an `ImplDerived` cause code for the
+// `&'a T: IntoIterator<Item = &'a u8>` obligation for `Helper::new`, which is
+// incorrect because derived obligations are only expected to come from *traits*.
+
+struct SeqBuffer<'a, T>
+where
+    &'a T: IntoIterator<Item = &'a u8>,
+{
+    iter: <&'a T as IntoIterator>::IntoIter,
+}
+
+struct Helper<'a, T>
+where
+    &'a T: IntoIterator<Item = &'a u8>,
+{
+    buf: SeqBuffer<'a, T>,
+}
+
+impl<'a, T> Helper<'a, T>
+where
+    &'a T: IntoIterator<Item = &'a u8>,
+{
+    fn new(sq: &'a T) -> Self {
+        loop {}
+    }
+}
+
+struct BitReaderWrapper<T>(T);
+
+impl<'a, T> IntoIterator for &'a BitReaderWrapper<T>
+where
+    &'a T: IntoIterator<Item = &'a u8>,
+{
+    type Item = u32;
+
+    type IntoIter = Helper<'a, T>;
+    //~^ ERROR `Helper<'a, T>` is not an iterator
+
+    fn into_iter(self) -> Self::IntoIter {
+        Helper::new(&self.0)
+        //~^ ERROR overflow evaluating the requirement `&_: IntoIterator`
+    }
+}
+
+fn main() {}

tests/ui/methods/inherent-bound-in-probe.stderr

@@ -0,0 +1,38 @@
+error[E0277]: `Helper<'a, T>` is not an iterator
+  --> $DIR/inherent-bound-in-probe.rs:40:21
+   |
+LL |     type IntoIter = Helper<'a, T>;
+   |                     ^^^^^^^^^^^^^ `Helper<'a, T>` is not an iterator
+   |
+   = help: the trait `Iterator` is not implemented for `Helper<'a, T>`
+note: required by a bound in `std::iter::IntoIterator::IntoIter`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+
+error[E0275]: overflow evaluating the requirement `&_: IntoIterator`
+  --> $DIR/inherent-bound-in-probe.rs:44:17
+   |
+LL |         Helper::new(&self.0)
+   |                 ^^^
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inherent_bound_in_probe`)
+note: required for `&BitReaderWrapper<_>` to implement `IntoIterator`
+  --> $DIR/inherent-bound-in-probe.rs:34:13
+   |
+LL | impl<'a, T> IntoIterator for &'a BitReaderWrapper<T>
+   |             ^^^^^^^^^^^^     ^^^^^^^^^^^^^^^^^^^^^^^
+LL | where
+LL |     &'a T: IntoIterator<Item = &'a u8>,
+   |                         ------------- unsatisfied trait bound introduced here
+   = note: 126 redundant requirements hidden
+   = note: required for `&BitReaderWrapper<BitReaderWrapper<BitReaderWrapper<BitReaderWrapper<BitReaderWrapper<...>>>>>` to implement `IntoIterator`
+   = note: the full type name has been written to '$TEST_BUILD_DIR/methods/inherent-bound-in-probe/inherent-bound-in-probe.long-type-hash.txt'
+note: required by a bound in `Helper<'a, T>`
+  --> $DIR/inherent-bound-in-probe.rs:25:25
+   |
+LL |     &'a T: IntoIterator<Item = &'a u8>,
+   |                         ^^^^^^^^^^^^^ required by this bound in `Helper<'a, T>`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0275, E0277.
+For more information about an error, try `rustc --explain E0275`.

tests/ui/parser/numeric-lifetime.rs

@@ -1,6 +1,6 @@
 struct S<'1> { s: &'1 usize }
-//~^ ERROR lifetimes or labels cannot start with a number
+//~^ ERROR lifetimes cannot start with a number
-//~| ERROR lifetimes or labels cannot start with a number
+//~| ERROR lifetimes cannot start with a number
 fn main() {
     // verify that the parse error doesn't stop type checking
     let x: usize = "";

tests/ui/parser/numeric-lifetime.stderr

@@ -6,13 +6,13 @@ LL |     let x: usize = "";
    |            |
    |            expected due to this
 
-error: lifetimes or labels cannot start with a number
+error: lifetimes cannot start with a number
   --> $DIR/numeric-lifetime.rs:1:10
    |
 LL | struct S<'1> { s: &'1 usize }
    |          ^^
 
-error: lifetimes or labels cannot start with a number
+error: lifetimes cannot start with a number
   --> $DIR/numeric-lifetime.rs:1:20
    |
 LL | struct S<'1> { s: &'1 usize }

tests/ui/test-attrs/issue-109816.rs

@@ -0,0 +1,7 @@
+// compile-flags: --test
+
+fn align_offset_weird_strides() {
+    #[test]
+    //~^ ERROR the `#[test]` attribute may only be used on a non-associated function
+    struct A5(u32, u8);
+}

tests/ui/test-attrs/issue-109816.stderr

@@ -0,0 +1,16 @@
+error: the `#[test]` attribute may only be used on a non-associated function
+  --> $DIR/issue-109816.rs:4:5
+   |
+LL |     #[test]
+   |     ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
+LL |
+LL |     struct A5(u32, u8);
+   |     ------------------- expected a non-associated function, found a struct
+   |
+help: replace with conditional compilation to make the item only exist when tests are being run
+   |
+LL |     #[cfg(test)]
+   |
+
+error: aborting due to previous error
+

tests/ui/test-attrs/test-attr-non-associated-functions.rs

@@ -1,18 +1,16 @@
-// #[test] attribute is not allowed on associated functions or methods
-// reworded error message
 // compile-flags:--test
 
 struct A {}
 
 impl A {
     #[test]
+    //~^ ERROR the `#[test]` attribute may only be used on a non-associated function
     fn new() -> A {
-        //~^ ERROR `#[test]` attribute is only allowed on non associated functions
         A {}
     }
     #[test]
+    //~^ ERROR the `#[test]` attribute may only be used on a non-associated function
     fn recovery_witness() -> A {
-        //~^ ERROR `#[test]` attribute is only allowed on non associated functions
         A {}
     }
 }

tests/ui/test-attrs/test-attr-non-associated-functions.stderr

@@ -1,20 +1,24 @@
-error: `#[test]` attribute is only allowed on non associated functions
+error: the `#[test]` attribute may only be used on a non-associated function
-  --> $DIR/test-attr-non-associated-functions.rs:9:5
+  --> $DIR/test-attr-non-associated-functions.rs:6:5
+   |
+LL |     #[test]
+   |     ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
+   |
+help: replace with conditional compilation to make the item only exist when tests are being run
+   |
+LL |     #[cfg(test)]
    |
-LL | /     fn new() -> A {
-LL | |
-LL | |         A {}
-LL | |     }
-   | |_____^
 
-error: `#[test]` attribute is only allowed on non associated functions
+error: the `#[test]` attribute may only be used on a non-associated function
-  --> $DIR/test-attr-non-associated-functions.rs:14:5
+  --> $DIR/test-attr-non-associated-functions.rs:11:5
+   |
+LL |     #[test]
+   |     ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
+   |
+help: replace with conditional compilation to make the item only exist when tests are being run
+   |
+LL |     #[cfg(test)]
    |
-LL | /     fn recovery_witness() -> A {
-LL | |
-LL | |         A {}
-LL | |     }
-   | |_____^
 
 error: aborting due to 2 previous errors
 

tests/ui/test-attrs/test-on-not-fn.stderr

@@ -2,7 +2,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:3:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | mod test {}
    | ----------- expected a non-associated function, found a module
    |
@@ -15,7 +15,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:6:1
    |
 LL |   #[test]
-   |   ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   |   ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | / mod loooooooooooooong_teeeeeeeeeest {
 LL | |     /*
 LL | |     this is a comment
@@ -34,7 +34,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:20:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | extern "C" {}
    | ------------- expected a non-associated function, found an extern block
    |
@@ -47,7 +47,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:23:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | trait Foo {}
    | ------------ expected a non-associated function, found a trait
    |
@@ -60,7 +60,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:26:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | impl Foo for i32 {}
    | ------------------- expected a non-associated function, found an implementation
    |
@@ -73,7 +73,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:29:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | const FOO: i32 = -1_i32;
    | ------------------------ expected a non-associated function, found a constant item
    |
@@ -86,7 +86,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:32:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | static BAR: u64 = 10_000_u64;
    | ----------------------------- expected a non-associated function, found a static item
    |
@@ -99,7 +99,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:35:1
    |
 LL |   #[test]
-   |   ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   |   ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | / enum MyUnit {
 LL | |     Unit,
 LL | | }
@@ -114,7 +114,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:40:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | struct NewI32(i32);
    | ------------------- expected a non-associated function, found a struct
    |
@@ -127,7 +127,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:43:1
    |
 LL |   #[test]
-   |   ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   |   ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | / union Spooky {
 LL | |     x: i32,
 LL | |     y: u32,
@@ -143,7 +143,7 @@ error: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:50:1
    |
 LL |   #[test]
-   |   ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   |   ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL |   #[derive(Copy, Clone, Debug)]
 LL | / struct MoreAttrs {
 LL | |     a: i32,
@@ -160,7 +160,7 @@ warning: the `#[test]` attribute may only be used on a non-associated function
   --> $DIR/test-on-not-fn.rs:61:1
    |
 LL | #[test]
-   | ^^^^^^^ the `#[test]` macro causes a function to be run on a test and has no effect on non-functions
+   | ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions
 LL | foo!();
    | ------- expected a non-associated function, found an item macro invocation
    |

tests/ui/traits/new-solver/recursive-self-normalization-2.rs

@@ -13,7 +13,7 @@ fn needs_bar<S: Bar>() {}
 
 fn test<T: Foo1<Assoc1 = <T as Foo2>::Assoc2> + Foo2<Assoc2 = <T as Foo1>::Assoc1>>() {
     needs_bar::<T::Assoc1>();
-    //~^ ERROR type annotations needed
+    //~^ ERROR overflow evaluating the requirement `<T as Foo1>::Assoc1: Bar`
 }
 
 fn main() {}

tests/ui/traits/new-solver/recursive-self-normalization-2.stderr

@@ -1,10 +1,10 @@
-error[E0283]: type annotations needed: cannot satisfy `<T as Foo1>::Assoc1: Bar`
+error[E0275]: overflow evaluating the requirement `<T as Foo1>::Assoc1: Bar`
   --> $DIR/recursive-self-normalization-2.rs:15:5
    |
 LL |     needs_bar::<T::Assoc1>();
    |     ^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: cannot satisfy `<T as Foo1>::Assoc1: Bar`
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`recursive_self_normalization_2`)
 note: required by a bound in `needs_bar`
   --> $DIR/recursive-self-normalization-2.rs:12:17
    |
@@ -13,4 +13,4 @@ LL | fn needs_bar<S: Bar>() {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0283`.
+For more information about this error, try `rustc --explain E0275`.

tests/ui/traits/new-solver/recursive-self-normalization.rs

@@ -9,7 +9,7 @@ fn needs_bar<S: Bar>() {}
 
 fn test<T: Foo<Assoc = <T as Foo>::Assoc>>() {
     needs_bar::<T::Assoc>();
-    //~^ ERROR type annotations needed
+    //~^ ERROR overflow evaluating the requirement `<T as Foo>::Assoc: Bar`
 }
 
 fn main() {}

tests/ui/traits/new-solver/recursive-self-normalization.stderr

@@ -1,10 +1,10 @@
-error[E0283]: type annotations needed: cannot satisfy `<T as Foo>::Assoc: Bar`
+error[E0275]: overflow evaluating the requirement `<T as Foo>::Assoc: Bar`
   --> $DIR/recursive-self-normalization.rs:11:5
    |
 LL |     needs_bar::<T::Assoc>();
    |     ^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: cannot satisfy `<T as Foo>::Assoc: Bar`
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`recursive_self_normalization`)
 note: required by a bound in `needs_bar`
   --> $DIR/recursive-self-normalization.rs:8:17
    |
@@ -13,4 +13,4 @@ LL | fn needs_bar<S: Bar>() {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0283`.
+For more information about this error, try `rustc --explain E0275`.