Rollup of 9 pull requests

compiler/rustc_hir_analysis/src/check/compare_method.rs

@@ -664,10 +664,7 @@ impl<'tcx> TypeFolder<'tcx> for ImplTraitInTraitCollector<'_, 'tcx> {
             });
             self.types.insert(proj.item_def_id, (infer_ty, proj.substs));
             // Recurse into bounds
-            for pred in self.tcx().bound_explicit_item_bounds(proj.item_def_id).transpose_iter() {
-                let pred_span = pred.0.1;
-
-                let pred = pred.map_bound(|(pred, _)| *pred).subst(self.tcx(), proj.substs);
+            for (pred, pred_span) in self.tcx().bound_explicit_item_bounds(proj.item_def_id).subst_iter_copied(self.tcx(), proj.substs) {
                 let pred = pred.fold_with(self);
                 let pred = self.ocx.normalize(
                     ObligationCause::misc(self.span, self.body_id),
@@ -1752,15 +1749,10 @@ pub fn check_type_bounds<'tcx>(
 
     let obligations = tcx
         .bound_explicit_item_bounds(trait_ty.def_id)
-        .transpose_iter()
-        .map(|e| e.map_bound(|e| *e).transpose_tuple2())
-        .map(|(bound, span)| {
-            debug!(?bound);
-            // this is where opaque type is found
-            let concrete_ty_bound = bound.subst(tcx, rebased_substs);
+        .subst_iter_copied(tcx, rebased_substs)
+        .map(|(concrete_ty_bound, span)| {
             debug!("check_type_bounds: concrete_ty_bound = {:?}", concrete_ty_bound);
-
-            traits::Obligation::new(mk_cause(span.0), param_env, concrete_ty_bound)
+            traits::Obligation::new(mk_cause(span), param_env, concrete_ty_bound)
         })
         .collect();
     debug!("check_type_bounds: item_bounds={:?}", obligations);

compiler/rustc_hir_typeck/src/_match.rs

@@ -514,8 +514,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
 
                 for ty in [first_ty, second_ty] {
-                    for pred in self.tcx.bound_explicit_item_bounds(rpit_def_id).transpose_iter() {
-                        let pred = pred.map_bound(|(pred, _)| *pred).subst(self.tcx, substs);
+                    for (pred, _) in self
+                        .tcx
+                        .bound_explicit_item_bounds(rpit_def_id)
+                        .subst_iter_copied(self.tcx, substs)
+                    {
                         let pred = match pred.kind().skip_binder() {
                             ty::PredicateKind::Trait(mut trait_pred) => {
                                 assert_eq!(trait_pred.trait_ref.self_ty(), opaque_ty);

compiler/rustc_hir_typeck/src/closure.rs

@@ -176,24 +176,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         match *expected_ty.kind() {
             ty::Opaque(def_id, substs) => {
                 let bounds = self.tcx.bound_explicit_item_bounds(def_id);
-                let sig = bounds
-                    .transpose_iter()
-                    .map(|e| e.map_bound(|e| *e).transpose_tuple2())
-                    .find_map(|(pred, span)| match pred.0.kind().skip_binder() {
+                let sig =
+                    bounds.subst_iter_copied(self.tcx, substs).find_map(|(pred, span)| match pred
+                        .kind()
+                        .skip_binder()
+                    {
                         ty::PredicateKind::Projection(proj_predicate) => self
                             .deduce_sig_from_projection(
-                                Some(span.0),
-                                pred.0
-                                    .kind()
-                                    .rebind(pred.rebind(proj_predicate).subst(self.tcx, substs)),
+                                Some(span),
+                                pred.kind().rebind(proj_predicate),
                             ),
                         _ => None,
                     });
 
                 let kind = bounds
-                    .transpose_iter()
-                    .map(|e| e.map_bound(|e| *e).transpose_tuple2())
-                    .filter_map(|(pred, _)| match pred.0.kind().skip_binder() {
+                    .0
+                    .iter()
+                    .filter_map(|(pred, _)| match pred.kind().skip_binder() {
                         ty::PredicateKind::Trait(tp) => {
                             self.tcx.fn_trait_kind_from_lang_item(tp.def_id())
                         }
@@ -697,18 +696,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty::Opaque(def_id, substs) => self
                 .tcx
                 .bound_explicit_item_bounds(def_id)
-                .transpose_iter()
-                .map(|e| e.map_bound(|e| *e).transpose_tuple2())
-                .find_map(|(p, s)| get_future_output(p.subst(self.tcx, substs), s.0))?,
+                .subst_iter_copied(self.tcx, substs)
+                .find_map(|(p, s)| get_future_output(p, s))?,
             ty::Error(_) => return None,
             ty::Projection(proj)
                 if self.tcx.def_kind(proj.item_def_id) == DefKind::ImplTraitPlaceholder =>
             {
                 self.tcx
                     .bound_explicit_item_bounds(proj.item_def_id)
-                    .transpose_iter()
-                    .map(|e| e.map_bound(|e| *e).transpose_tuple2())
-                    .find_map(|(p, s)| get_future_output(p.subst(self.tcx, proj.substs), s.0))?
+                    .subst_iter_copied(self.tcx, proj.substs)
+                    .find_map(|(p, s)| get_future_output(p, s))?
             }
             _ => span_bug!(
                 self.tcx.def_span(expr_def_id),

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -338,8 +338,7 @@ impl<'tcx> InferCtxt<'tcx> {
 
             let bounds = self.tcx.bound_explicit_item_bounds(*def_id);
 
-            for predicate in bounds.transpose_iter().map(|e| e.map_bound(|(p, _)| *p)) {
-                let predicate = predicate.subst(self.tcx, substs);
+            for (predicate, _) in bounds.subst_iter_copied(self.tcx, substs) {
                 let output = predicate
                     .kind()
                     .map_bound(|kind| match kind {
@@ -2272,6 +2271,25 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 struct_span_err!(self.tcx.sess, span, E0580, "{}", failure_str)
             }
             FailureCode::Error0308(failure_str) => {
+                fn escape_literal(s: &str) -> String {
+                    let mut escaped = String::with_capacity(s.len());
+                    let mut chrs = s.chars().peekable();
+                    while let Some(first) = chrs.next() {
+                        match (first, chrs.peek()) {
+                            ('\\', Some(&delim @ '"') | Some(&delim @ '\'')) => {
+                                escaped.push('\\');
+                                escaped.push(delim);
+                                chrs.next();
+                            }
+                            ('"' | '\'', _) => {
+                                escaped.push('\\');
+                                escaped.push(first)
+                            }
+                            (c, _) => escaped.push(c),
+                        };
+                    }
+                    escaped
+                }
                 let mut err = struct_span_err!(self.tcx.sess, span, E0308, "{}", failure_str);
                 if let Some((expected, found)) = trace.values.ty() {
                     match (expected.kind(), found.kind()) {
@@ -2293,7 +2311,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                                 err.span_suggestion(
                                     span,
                                     "if you meant to write a `char` literal, use single quotes",
-                                    format!("'{}'", code),
+                                    format!("'{}'", escape_literal(code)),
                                     Applicability::MachineApplicable,
                                 );
                             }
@@ -2308,7 +2326,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                                     err.span_suggestion(
                                         span,
                                         "if you meant to write a `str` literal, use double quotes",
-                                        format!("\"{}\"", code),
+                                        format!("\"{}\"", escape_literal(code)),
                                         Applicability::MachineApplicable,
                                     );
                                 }

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -1,6 +1,7 @@
 use crate::errors::OpaqueHiddenTypeDiag;
 use crate::infer::{DefiningAnchor, InferCtxt, InferOk};
 use crate::traits;
+use hir::def::DefKind;
 use hir::def_id::{DefId, LocalDefId};
 use hir::{HirId, OpaqueTyOrigin};
 use rustc_data_structures::sync::Lrc;
@@ -543,16 +544,18 @@ impl<'tcx> InferCtxt<'tcx> {
 
         let item_bounds = tcx.bound_explicit_item_bounds(def_id.to_def_id());
 
-        for predicate in item_bounds.transpose_iter().map(|e| e.map_bound(|(p, _)| *p)) {
-            debug!(?predicate);
-            let predicate = predicate.subst(tcx, substs);
-
+        for (predicate, _) in item_bounds.subst_iter_copied(tcx, substs) {
             let predicate = predicate.fold_with(&mut BottomUpFolder {
                 tcx,
                 ty_op: |ty| match *ty.kind() {
                     // We can't normalize associated types from `rustc_infer`,
                     // but we can eagerly register inference variables for them.
-                    ty::Projection(projection_ty) if !projection_ty.has_escaping_bound_vars() => {
+                    // FIXME(RPITIT): Don't replace RPITITs with inference vars.
+                    ty::Projection(projection_ty)
+                        if !projection_ty.has_escaping_bound_vars()
+                            && tcx.def_kind(projection_ty.item_def_id)
+                                != DefKind::ImplTraitPlaceholder =>
+                    {
                         self.infer_projection(
                             param_env,
                             projection_ty,
@@ -568,6 +571,12 @@ impl<'tcx> InferCtxt<'tcx> {
                     {
                         hidden_ty
                     }
+                    // FIXME(RPITIT): This can go away when we move to associated types
+                    ty::Projection(proj)
+                        if def_id.to_def_id() == proj.item_def_id && substs == proj.substs =>
+                    {
+                        hidden_ty
+                    }
                     _ => ty,
                 },
                 lt_op: |lt| lt,

compiler/rustc_lint/src/levels.rs

@@ -960,7 +960,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                                         sp,
                                         "did you mean",
                                         suggestion,
-                                        Applicability::MachineApplicable,
+                                        Applicability::MaybeIncorrect,
                                     );
                                 }
                                 lint

compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs

@@ -91,14 +91,12 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound {
             // For example, in `impl Trait<Assoc = impl Send>`, for all of the bounds on `Assoc`,
             // e.g. `type Assoc: OtherTrait`, replace `<impl Trait as Trait>::Assoc: OtherTrait`
             // with `impl Send: OtherTrait`.
-            for assoc_pred_and_span in
-                cx.tcx.bound_explicit_item_bounds(proj.projection_ty.item_def_id).transpose_iter()
+            for (assoc_pred, assoc_pred_span) in cx
+                .tcx
+                .bound_explicit_item_bounds(proj.projection_ty.item_def_id)
+                .subst_iter_copied(cx.tcx, &proj.projection_ty.substs)
             {
-                let assoc_pred_span = assoc_pred_and_span.0.1;
-                let assoc_pred = assoc_pred_and_span
-                    .map_bound(|(pred, _)| *pred)
-                    .subst(cx.tcx, &proj.projection_ty.substs)
-                    .fold_with(proj_replacer);
+                let assoc_pred = assoc_pred.fold_with(proj_replacer);
                 let Ok(assoc_pred) = traits::fully_normalize(infcx, traits::ObligationCause::dummy(), cx.param_env, assoc_pred) else {
                     continue;
                 };

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -795,8 +795,7 @@ pub trait PrettyPrinter<'tcx>:
         let mut fn_traits = FxIndexMap::default();
         let mut is_sized = false;
 
-        for predicate in bounds.transpose_iter().map(|e| e.map_bound(|(p, _)| *p)) {
-            let predicate = predicate.subst(tcx, substs);
+        for (predicate, _) in bounds.subst_iter_copied(tcx, substs) {
             let bound_predicate = predicate.kind();
 
             match bound_predicate.skip_binder() {

compiler/rustc_middle/src/ty/subst.rs

@@ -6,6 +6,7 @@ use crate::ty::sty::{ClosureSubsts, GeneratorSubsts, InlineConstSubsts};
 use crate::ty::visit::{TypeVisitable, TypeVisitor};
 use crate::ty::{self, Lift, List, ParamConst, Ty, TyCtxt};
 
+use rustc_data_structures::captures::Captures;
 use rustc_data_structures::intern::{Interned, WithStableHash};
 use rustc_hir::def_id::DefId;
 use rustc_macros::HashStable;
@@ -558,6 +559,28 @@ impl<T, U> EarlyBinder<(T, U)> {
     }
 }
 
+impl<'tcx, 's, T: IntoIterator<Item = I>, I: TypeFoldable<'tcx>> EarlyBinder<T> {
+    pub fn subst_iter(
+        self,
+        tcx: TyCtxt<'tcx>,
+        substs: &'s [GenericArg<'tcx>],
+    ) -> impl Iterator<Item = I> + Captures<'s> + Captures<'tcx> {
+        self.0.into_iter().map(move |t| EarlyBinder(t).subst(tcx, substs))
+    }
+}
+
+impl<'tcx, 's, 'a, T: IntoIterator<Item = &'a I>, I: Copy + TypeFoldable<'tcx> + 'a>
+    EarlyBinder<T>
+{
+    pub fn subst_iter_copied(
+        self,
+        tcx: TyCtxt<'tcx>,
+        substs: &'s [GenericArg<'tcx>],
+    ) -> impl Iterator<Item = I> + Captures<'s> + Captures<'tcx> + Captures<'a> {
+        self.0.into_iter().map(move |t| EarlyBinder(*t).subst(tcx, substs))
+    }
+}
+
 pub struct EarlyBinderIter<T> {
     t: T,
 }

compiler/rustc_parse/src/lexer/unescape_error_reporting.rs

@@ -113,11 +113,26 @@ pub(crate) fn emit_unescape_error(
                 } else {
                     ("", "if you meant to write a `str` literal, use double quotes")
                 };
-
+                let mut escaped = String::with_capacity(lit.len());
+                let mut chrs = lit.chars().peekable();
+                while let Some(first) = chrs.next() {
+                    match (first, chrs.peek()) {
+                        ('\\', Some('"')) => {
+                            escaped.push('\\');
+                            escaped.push('"');
+                            chrs.next();
+                        }
+                        ('"', _) => {
+                            escaped.push('\\');
+                            escaped.push('"')
+                        }
+                        (c, _) => escaped.push(c),
+                    };
+                }
                 handler.span_suggestion(
                     span_with_quotes,
                     msg,
-                    format!("{}\"{}\"", prefix, lit),
+                    format!("{prefix}\"{escaped}\""),
                     Applicability::MachineApplicable,
                 );
             }

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -14,6 +14,7 @@ use rustc_infer::traits::Normalized;
 use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
 use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitor};
+use rustc_span::DUMMY_SP;
 
 use std::ops::ControlFlow;
 
@@ -253,7 +254,15 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
                 let result = tcx.normalize_projection_ty(c_data)?;
                 // We don't expect ambiguity.
                 if result.is_ambiguous() {
-                    bug!("unexpected ambiguity: {:?} {:?}", c_data, result);
+                    // Rustdoc normalizes possibly not well-formed types, so only
+                    // treat this as a bug if we're not in rustdoc.
+                    if !tcx.sess.opts.actually_rustdoc {
+                        tcx.sess.delay_span_bug(
+                            DUMMY_SP,
+                            format!("unexpected ambiguity: {:?} {:?}", c_data, result),
+                        );
+                    }
+                    return Err(NoSolution);
                 }
                 let InferOk { value: result, obligations } =
                     self.infcx.instantiate_query_response_and_region_obligations(
@@ -296,7 +305,15 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
                 let result = tcx.normalize_projection_ty(c_data)?;
                 // We don't expect ambiguity.
                 if result.is_ambiguous() {
-                    bug!("unexpected ambiguity: {:?} {:?}", c_data, result);
+                    // Rustdoc normalizes possibly not well-formed types, so only
+                    // treat this as a bug if we're not in rustdoc.
+                    if !tcx.sess.opts.actually_rustdoc {
+                        tcx.sess.delay_span_bug(
+                            DUMMY_SP,
+                            format!("unexpected ambiguity: {:?} {:?}", c_data, result),
+                        );
+                    }
+                    return Err(NoSolution);
                 }
                 let InferOk { value: result, obligations } =
                     self.infcx.instantiate_query_response_and_region_obligations(

library/alloc/src/string.rs

@@ -1851,7 +1851,7 @@ impl String {
     }
 
     /// Consumes and leaks the `String`, returning a mutable reference to the contents,
-    /// `&'a mut str`.
+    /// `&'static mut str`.
     ///
     /// This is mainly useful for data that lives for the remainder of
     /// the program's life. Dropping the returned reference will cause a memory

library/std/src/sys/unix/thread.rs

@@ -132,8 +132,11 @@ impl Thread {
 
     #[cfg(target_os = "linux")]
     pub fn set_name(name: &CStr) {
+        const TASK_COMM_LEN: usize = 16;
+
         unsafe {
             // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20.
+            let name = truncate_cstr(name, TASK_COMM_LEN);
             libc::pthread_setname_np(libc::pthread_self(), name.as_ptr());
         }
     }
@@ -148,6 +151,7 @@ impl Thread {
     #[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))]
     pub fn set_name(name: &CStr) {
         unsafe {
+            let name = truncate_cstr(name, libc::MAXTHREADNAMESIZE);
             libc::pthread_setname_np(name.as_ptr());
         }
     }
@@ -276,6 +280,20 @@ impl Drop for Thread {
     }
 }
 
+#[cfg(any(target_os = "linux", target_os = "macos", target_os = "ios", target_os = "watchos"))]
+fn truncate_cstr(cstr: &CStr, max_with_nul: usize) -> crate::borrow::Cow<'_, CStr> {
+    use crate::{borrow::Cow, ffi::CString};
+
+    if cstr.to_bytes_with_nul().len() > max_with_nul {
+        let bytes = cstr.to_bytes()[..max_with_nul - 1].to_vec();
+        // SAFETY: the non-nul bytes came straight from a CStr.
+        // (CString will add the terminating nul.)
+        Cow::Owned(unsafe { CString::from_vec_unchecked(bytes) })
+    } else {
+        Cow::Borrowed(cstr)
+    }
+}
+
 pub fn available_parallelism() -> io::Result<NonZeroUsize> {
     cfg_if::cfg_if! {
         if #[cfg(any(

library/std/src/thread/tests.rs

@@ -37,6 +37,31 @@ fn test_named_thread() {
         .unwrap();
 }
 
+#[cfg(any(target_os = "linux", target_os = "macos", target_os = "ios", target_os = "watchos"))]
+#[test]
+fn test_named_thread_truncation() {
+    use crate::ffi::CStr;
+
+    let long_name = crate::iter::once("test_named_thread_truncation")
+        .chain(crate::iter::repeat(" yada").take(100))
+        .collect::<String>();
+
+    let result = Builder::new().name(long_name.clone()).spawn(move || {
+        // Rust remembers the full thread name itself.
+        assert_eq!(thread::current().name(), Some(long_name.as_str()));
+
+        // But the system is limited -- make sure we successfully set a truncation.
+        let mut buf = vec![0u8; long_name.len() + 1];
+        unsafe {
+            libc::pthread_getname_np(libc::pthread_self(), buf.as_mut_ptr().cast(), buf.len());
+        }
+        let cstr = CStr::from_bytes_until_nul(&buf).unwrap();
+        assert!(cstr.to_bytes().len() > 0);
+        assert!(long_name.as_bytes().starts_with(cstr.to_bytes()));
+    });
+    result.unwrap().join().unwrap();
+}
+
 #[test]
 #[should_panic]
 fn test_invalid_named_thread() {

src/librustdoc/html/static/css/rustdoc.css

@@ -920,7 +920,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	flex-flow: row wrap;
 }
 
-.search-results .result-name, .search-results div.desc, .search-results .result-description {
+.search-results .result-name, .search-results div.desc {
 	width: 50%;
 }
 .search-results .result-name {
@@ -1899,10 +1899,10 @@ in storage.js
 		border-bottom: 1px solid #aaa9;
 		padding: 5px 0px;
 	}
-	.search-results .result-name, .search-results div.desc, .search-results .result-description {
+	.search-results .result-name, .search-results div.desc {
 		width: 100%;
 	}
-	.search-results div.desc, .search-results .result-description, .item-right {
+	.search-results div.desc, .item-right {
 		padding-left: 2em;
 	}
 

src/test/rustdoc-gui/headings.goml

@@ -150,109 +150,85 @@ assert-css: ("h2#top-doc-prose-title", {"border-bottom-width": "1px"})
 assert-css: ("h3#top-doc-prose-sub-heading", {"font-size": "20px"})
 assert-css: ("h3#top-doc-prose-sub-heading", {"border-bottom-width": "1px"})
 
-// Checking colors now.
+// Needed to check colors
 show-text: true
-local-storage: {"rustdoc-theme": "light", "rustdoc-use-system-theme": "false"}
 goto: "file://" + |DOC_PATH| + "/test_docs/struct.HeavilyDocumentedStruct.html"
-assert-css: (
-    ".top-doc .docblock h2",
-    {"color": "rgb(0, 0, 0)", "border-bottom": "1px solid rgb(221, 221, 221)"},
-)
-assert-css: (
-    ".top-doc .docblock h3",
-    {"color": "rgb(0, 0, 0)", "border-bottom": "1px solid rgb(221, 221, 221)"},
-)
-assert-css: (
-    ".top-doc .docblock h4",
-    {"color": "rgb(0, 0, 0)", "border-bottom": "1px solid rgb(221, 221, 221)"},
-)
-assert-css: (
-    ".top-doc .docblock h5",
-    {"color": "rgb(0, 0, 0)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h4",
-    {"color": "rgb(0, 0, 0)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h5",
-    {"color": "rgb(0, 0, 0)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h6",
-    {"color": "rgb(0, 0, 0)", "border-bottom-width": "0px"},
-)
 
-local-storage: {"rustdoc-theme": "dark"}
-reload:
-assert-css: (
-    ".top-doc .docblock h2",
-    {"color": "rgb(221, 221, 221)", "border-bottom": "1px solid rgb(210, 210, 210)"},
-)
-assert-css: (
-    ".top-doc .docblock h3",
-    {"color": "rgb(221, 221, 221)", "border-bottom": "1px solid rgb(210, 210, 210)"},
-)
-assert-css: (
-    ".top-doc .docblock h4",
-    {"color": "rgb(221, 221, 221)", "border-bottom": "1px solid rgb(210, 210, 210)"},
-)
-assert-css: (
-    ".top-doc .docblock h5",
-    {"color": "rgb(221, 221, 221)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h4",
-    {"color": "rgb(221, 221, 221)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h5",
-    {"color": "rgb(221, 221, 221)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h6",
-    {"color": "rgb(221, 221, 221)", "border-bottom-width": "0px"},
+define-function: (
+    "check-colors",
+    (theme, heading_color, small_heading_color, heading_border_color),
+    [
+        ("local-storage", {"rustdoc-theme": |theme|, "rustdoc-use-system-theme": "false"}),
+        ("reload"),
+        ("assert-css", (
+            ".top-doc .docblock h2",
+            {"color": |heading_color|, "border-bottom": "1px solid " + |heading_border_color|},
+        )),
+        ("assert-css", (
+            ".top-doc .docblock h3",
+            {"color": |heading_color|, "border-bottom": "1px solid " + |heading_border_color|},
+        )),
+        ("assert-css", (
+            ".top-doc .docblock h4",
+            {"color": |heading_color|, "border-bottom": "1px solid " + |heading_border_color|},
+        )),
+        ("assert-css", (
+            ".top-doc .docblock h5",
+            {"color": |small_heading_color|, "border-bottom-width": "0px"},
+        )),
+        ("assert-css", (
+            "#implementations-list .docblock h4",
+            {"color": |heading_color|, "border-bottom-width": "0px"},
+        )),
+        ("assert-css", (
+            "#implementations-list .docblock h5",
+            {"color": |small_heading_color|, "border-bottom-width": "0px"},
+        )),
+        ("assert-css", (
+            "#implementations-list .docblock h6",
+            {"color": |small_heading_color|, "border-bottom-width": "0px"},
+        )),
+    ],
+)
+call-function: (
+    "check-colors",
+    {
+        "theme": "ayu",
+        "heading_color": "rgb(255, 255, 255)",
+        "small_heading_color": "rgb(197, 197, 197)",
+        "heading_border_color": "rgb(92, 103, 115)",
+    },
+)
+call-function: (
+    "check-colors",
+    {
+        "theme": "dark",
+        "heading_color": "rgb(221, 221, 221)",
+        "small_heading_color": "rgb(221, 221, 221)",
+        "heading_border_color": "rgb(210, 210, 210)",
+    },
+)
+call-function: (
+    "check-colors",
+    {
+        "theme": "light",
+        "heading_color": "rgb(0, 0, 0)",
+        "small_heading_color": "rgb(0, 0, 0)",
+        "heading_border_color": "rgb(221, 221, 221)",
+    },
+)
+
+define-function: (
+    "check-since-color",
+    (theme),
+    [
+        ("local-storage", {"rustdoc-theme": |theme|}),
+        ("reload"),
+        ("assert-css", (".since", {"color": "rgb(128, 128, 128)"}, ALL)),
+    ],
 )
 
-local-storage: {"rustdoc-theme": "ayu"}
-reload:
-assert-css: (
-    ".top-doc .docblock h2",
-    {"color": "rgb(255, 255, 255)", "border-bottom": "1px solid rgb(92, 103, 115)"},
-)
-assert-css: (
-    ".top-doc .docblock h2",
-    {"color": "rgb(255, 255, 255)", "border-bottom": "1px solid rgb(92, 103, 115)"},
-)
-assert-css: (
-    ".top-doc .docblock h4",
-    {"color": "rgb(255, 255, 255)", "border-bottom": "1px solid rgb(92, 103, 115)"},
-)
-assert-css: (
-    ".top-doc .docblock h5",
-    {"color": "rgb(197, 197, 197)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h4",
-    {"color": "rgb(255, 255, 255)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h5",
-    {"color": "rgb(197, 197, 197)", "border-bottom-width": "0px"},
-)
-assert-css: (
-    "#implementations-list .docblock h6",
-    {"color": "rgb(197, 197, 197)", "border-bottom-width": "0px"},
-)
-
-local-storage: {"rustdoc-theme": "light"}
 goto: "file://" + |DOC_PATH| + "/staged_api/struct.Foo.html"
-assert-css: (".since", {"color": "rgb(128, 128, 128)"}, ALL)
-
-local-storage: {"rustdoc-theme": "dark"}
-reload:
-assert-css: (".since", {"color": "rgb(128, 128, 128)"}, ALL)
-
-local-storage: {"rustdoc-theme": "ayu"}
-reload:
-assert-css: (".since", {"color": "rgb(128, 128, 128)"}, ALL)
+call-function: ("check-since-color", ("ayu"))
+call-function: ("check-since-color", ("dark"))
+call-function: ("check-since-color", ("light"))

src/test/rustdoc/not-wf-ambiguous-normalization.rs

@@ -0,0 +1,24 @@
+// compile-flags: -Znormalize-docs
+
+#![feature(type_alias_impl_trait)]
+
+trait Allocator {
+    type Buffer;
+}
+
+struct DefaultAllocator;
+
+// This unconstrained impl parameter causes the normalization of
+// `<DefaultAllocator as Allocator>::Buffer` to be ambiguous,
+// which caused an ICE with `-Znormalize-docs`.
+impl<T> Allocator for DefaultAllocator {
+    type Buffer = ();
+}
+
+type A = impl Fn(<DefaultAllocator as Allocator>::Buffer);
+
+fn foo() -> A {
+    |_| ()
+}
+
+fn main() {}

src/test/ui/impl-trait/in-trait/default-body-type-err-2.rs

@@ -0,0 +1,13 @@
+// edition:2021
+
+#![allow(incomplete_features)]
+#![feature(async_fn_in_trait)]
+
+pub trait Foo {
+    async fn woopsie_async(&self) -> String {
+        42
+        //~^ ERROR mismatched types
+    }
+}
+
+fn main() {}

src/test/ui/impl-trait/in-trait/default-body-type-err-2.stderr

@@ -0,0 +1,11 @@
+error[E0308]: mismatched types
+  --> $DIR/default-body-type-err-2.rs:8:9
+   |
+LL |         42
+   |         ^^- help: try using a conversion method: `.to_string()`
+   |         |
+   |         expected struct `String`, found integer
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/impl-trait/in-trait/default-body-type-err.rs

@@ -0,0 +1,13 @@
+#![allow(incomplete_features)]
+#![feature(return_position_impl_trait_in_trait)]
+
+use std::ops::Deref;
+
+pub trait Foo {
+    fn lol(&self) -> impl Deref<Target = String> {
+        //~^ type mismatch resolving `<&i32 as Deref>::Target == String`
+        &1i32
+    }
+}
+
+fn main() {}

src/test/ui/impl-trait/in-trait/default-body-type-err.stderr

@@ -0,0 +1,12 @@
+error[E0271]: type mismatch resolving `<&i32 as Deref>::Target == String`
+  --> $DIR/default-body-type-err.rs:7:22
+   |
+LL |     fn lol(&self) -> impl Deref<Target = String> {
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `i32`, found struct `String`
+LL |
+LL |         &1i32
+   |         ----- return type was inferred to be `&i32` here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0271`.

src/test/ui/impl-trait/in-trait/default-body-with-rpit.rs

@@ -1,4 +1,4 @@
-// known-bug: #102688
+// check-pass
 // edition:2021
 
 #![feature(async_fn_in_trait, return_position_impl_trait_in_trait)]

src/test/ui/impl-trait/issue-103181-1.rs

@@ -0,0 +1,85 @@
+// edition:2021
+
+mod hyper {
+    use std::{fmt::Debug, future::Future, marker::PhantomData, pin::Pin, task::Poll};
+
+    pub trait HttpBody {
+        type Error;
+    }
+    impl HttpBody for () {
+        //~^ ERROR not all trait items implemented, missing: `Error`
+        // don't implement `Error` here for the ICE
+    }
+
+    pub struct Server<I, S>(I, S);
+
+    pub fn serve<I, S>(_: S) -> Server<I, S> {
+        todo!()
+    }
+
+    impl<S, B> Future for Server<(), S>
+    where
+        S: MakeServiceRef<(), (), ResBody = B>,
+        B: HttpBody,
+        B::Error: Debug,
+    {
+        type Output = ();
+
+        fn poll(self: Pin<&mut Self>, _: &mut std::task::Context<'_>) -> Poll<Self::Output> {
+            todo!()
+        }
+    }
+
+    pub trait MakeServiceRef<Target, ReqBody> {
+        type ResBody;
+    }
+
+    impl<T, S> MakeServiceRef<(), ()> for T
+    where
+        T: for<'a> Service<&'a (), Response = S>,
+        S: Service<()>,
+    {
+        type ResBody = ();
+    }
+
+    pub struct MakeServiceFn<F>(pub F);
+    pub struct ServiceFn<F, R>(pub PhantomData<(F, R)>);
+
+    pub trait Service<Request> {
+        type Response;
+    }
+
+    impl<'t, F, Ret, Target, Svc> Service<&'t Target> for MakeServiceFn<F>
+    where
+        F: Fn() -> Ret,
+        Ret: Future<Output = Result<Svc, ()>>,
+    {
+        type Response = Svc;
+    }
+
+    impl<F, ReqBody, Ret, ResBody, E> Service<ReqBody> for ServiceFn<F, ReqBody>
+    where
+        F: Fn() -> Ret,
+        Ret: Future<Output = Result<ResBody, E>>,
+    {
+        type Response = ResBody;
+    }
+}
+
+async fn smarvice() -> Result<(), ()> {
+    Ok(())
+}
+
+fn service_fn<F, R, S>(f: F) -> hyper::ServiceFn<F, R>
+where
+    F: Fn() -> S,
+{
+    hyper::ServiceFn(std::marker::PhantomData)
+}
+
+async fn iceice() {
+    let service = hyper::MakeServiceFn(|| async { Ok::<_, ()>(service_fn(|| smarvice())) });
+    hyper::serve::<(), _>(service).await;
+}
+
+fn main() {}

src/test/ui/impl-trait/issue-103181-1.stderr

@@ -0,0 +1,12 @@
+error[E0046]: not all trait items implemented, missing: `Error`
+  --> $DIR/issue-103181-1.rs:9:5
+   |
+LL |         type Error;
+   |         ---------- `Error` from trait
+LL |     }
+LL |     impl HttpBody for () {
+   |     ^^^^^^^^^^^^^^^^^^^^ missing `Error` in implementation
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0046`.

src/test/ui/impl-trait/issue-103181-2.rs

@@ -0,0 +1,29 @@
+// edition:2021
+
+trait SendFuture: Send {
+    type Output;
+}
+
+impl<Fut: Send> SendFuture for Fut {
+    type Output = ();
+}
+
+async fn broken_fut() {
+    ident_error;
+    //~^ ERROR cannot find value `ident_error` in this scope
+}
+
+// triggers normalization of `<Fut as SendFuture>::Output`,
+// which requires `Fut: Send`.
+fn normalize<Fut: SendFuture>(_: Fut, _: Fut::Output) {}
+
+async fn iceice<A, B>()
+// <- async fn is necessary
+where
+    A: Send,
+    B: Send, // <- a second bound
+{
+    normalize(broken_fut(), ());
+}
+
+fn main() {}

src/test/ui/impl-trait/issue-103181-2.stderr

@@ -0,0 +1,9 @@
+error[E0425]: cannot find value `ident_error` in this scope
+  --> $DIR/issue-103181-2.rs:12:5
+   |
+LL |     ident_error;
+   |     ^^^^^^^^^^^ not found in this scope
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0425`.

src/test/ui/inference/char-as-str-single.fixed

@@ -8,4 +8,5 @@
 fn main() {
     let _: char = 'a'; //~ ERROR mismatched types
     let _: char = '人'; //~ ERROR mismatched types
+    let _: char = '\''; //~ ERROR mismatched types
 }

src/test/ui/inference/char-as-str-single.rs

@@ -8,4 +8,5 @@
 fn main() {
     let _: char = "a"; //~ ERROR mismatched types
     let _: char = "人"; //~ ERROR mismatched types
+    let _: char = "'"; //~ ERROR mismatched types
 }

src/test/ui/inference/char-as-str-single.stderr

@@ -24,6 +24,19 @@ help: if you meant to write a `char` literal, use single quotes
 LL |     let _: char = '人';
    |                   ~~~~
 
-error: aborting due to 2 previous errors
+error[E0308]: mismatched types
+  --> $DIR/char-as-str-single.rs:11:19
+   |
+LL |     let _: char = "'";
+   |            ----   ^^^ expected `char`, found `&str`
+   |            |
+   |            expected due to this
+   |
+help: if you meant to write a `char` literal, use single quotes
+   |
+LL |     let _: char = '\'';
+   |                   ~~~~
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0308`.

src/test/ui/inference/str-as-char.fixed

@@ -4,5 +4,7 @@
 // run-rustfix
 
 fn main() {
-    let _: &str = "a"; //~ ERROR mismatched types
+    let _: &str = "a";   //~ ERROR mismatched types
+    let _: &str = "\"\"\""; //~ ERROR character literal may only contain one codepoint
+    let _: &str = "\"\"\""; //~ ERROR character literal may only contain one codepoint
 }

src/test/ui/inference/str-as-char.rs

@@ -4,5 +4,7 @@
 // run-rustfix
 
 fn main() {
-    let _: &str = 'a'; //~ ERROR mismatched types
+    let _: &str = 'a';   //~ ERROR mismatched types
+    let _: &str = '"""'; //~ ERROR character literal may only contain one codepoint
+    let _: &str = '\"\"\"'; //~ ERROR character literal may only contain one codepoint
 }

src/test/ui/inference/str-as-char.stderr

@@ -1,3 +1,25 @@
+error: character literal may only contain one codepoint
+  --> $DIR/str-as-char.rs:8:19
+   |
+LL |     let _: &str = '"""';
+   |                   ^^^^^
+   |
+help: if you meant to write a `str` literal, use double quotes
+   |
+LL |     let _: &str = "\"\"\"";
+   |                   ~~~~~~~~
+
+error: character literal may only contain one codepoint
+  --> $DIR/str-as-char.rs:9:19
+   |
+LL |     let _: &str = '\"\"\"';
+   |                   ^^^^^^^^
+   |
+help: if you meant to write a `str` literal, use double quotes
+   |
+LL |     let _: &str = "\"\"\"";
+   |                   ~~~~~~~~
+
 error[E0308]: mismatched types
   --> $DIR/str-as-char.rs:7:19
    |
@@ -11,6 +33,6 @@ help: if you meant to write a `str` literal, use double quotes
 LL |     let _: &str = "a";
    |                   ~~~
 
-error: aborting due to previous error
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0308`.

src/tools/clippy/clippy_utils/src/ty.rs

@@ -657,21 +657,18 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: ProjectionTy<'tcx>) -> O
     let mut output = None;
     let lang_items = cx.tcx.lang_items();
 
-    for pred in cx
+    for (pred, _) in cx
         .tcx
         .bound_explicit_item_bounds(ty.item_def_id)
-        .transpose_iter()
-        .map(|x| x.map_bound(|(p, _)| p))
+        .subst_iter_copied(cx.tcx, ty.substs)
     {
-        match pred.0.kind().skip_binder() {
+        match pred.kind().skip_binder() {
             PredicateKind::Trait(p)
                 if (lang_items.fn_trait() == Some(p.def_id())
                     || lang_items.fn_mut_trait() == Some(p.def_id())
                     || lang_items.fn_once_trait() == Some(p.def_id())) =>
             {
-                let i = pred
-                    .map_bound(|pred| pred.kind().rebind(p.trait_ref.substs.type_at(1)))
-                    .subst(cx.tcx, ty.substs);
+                let i = pred.kind().rebind(p.trait_ref.substs.type_at(1));
 
                 if inputs.map_or(false, |inputs| inputs != i) {
                     // Multiple different fn trait impls. Is this even allowed?
@@ -684,10 +681,7 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: ProjectionTy<'tcx>) -> O
                     // Multiple different fn trait impls. Is this even allowed?
                     return None;
                 }
-                output = Some(
-                    pred.map_bound(|pred| pred.kind().rebind(p.term.ty().unwrap()))
-                        .subst(cx.tcx, ty.substs),
-                );
+                output = pred.kind().rebind(p.term.ty()).transpose();
             },
             _ => (),
         }