diff --git a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
index c1d95d07f4c65..b9b6ca261193f 100644
--- a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
@@ -10,7 +10,7 @@ use crate::session_diagnostics;
 
 pub(crate) struct AllowInternalUnstableParser;
 impl CombineAttributeParser for AllowInternalUnstableParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::allow_internal_unstable];
+    const PATH: &'static [Symbol] = &[sym::allow_internal_unstable];
     type Item = (Symbol, Span);
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::AllowInternalUnstable;
 
@@ -24,7 +24,7 @@ impl CombineAttributeParser for AllowInternalUnstableParser {
 
 pub(crate) struct AllowConstFnUnstableParser;
 impl CombineAttributeParser for AllowConstFnUnstableParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_allow_const_fn_unstable];
+    const PATH: &'static [Symbol] = &[sym::rustc_allow_const_fn_unstable];
     type Item = Symbol;
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::AllowConstFnUnstable;
 
diff --git a/compiler/rustc_attr_parsing/src/attributes/deprecation.rs b/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
index fb3d5f57d4fac..1775770ec680e 100644
--- a/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
@@ -42,9 +42,9 @@ fn get(
 }
 
 impl SingleAttributeParser for DeprecationParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::deprecated];
+    const PATH: &'static [Symbol] = &[sym::deprecated];
 
-    fn on_duplicate(cx: &AcceptContext<'_>, first_span: rustc_span::Span) {
+    fn on_duplicate(cx: &AcceptContext<'_>, first_span: Span) {
         // FIXME(jdonszelmann): merge with errors from check_attrs.rs
         cx.emit_err(session_diagnostics::UnusedMultiple {
             this: cx.attr_span,
diff --git a/compiler/rustc_attr_parsing/src/attributes/mod.rs b/compiler/rustc_attr_parsing/src/attributes/mod.rs
index 6ecd6b4d7dbb7..f45cf984f7191 100644
--- a/compiler/rustc_attr_parsing/src/attributes/mod.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/mod.rs
@@ -17,7 +17,7 @@
 use std::marker::PhantomData;
 
 use rustc_attr_data_structures::AttributeKind;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 use thin_vec::ThinVec;
 
 use crate::context::{AcceptContext, FinalizeContext};
@@ -33,7 +33,7 @@ pub(crate) mod transparency;
 pub(crate) mod util;
 
 type AcceptFn<T> = fn(&mut T, &AcceptContext<'_>, &ArgParser<'_>);
-type AcceptMapping<T> = &'static [(&'static [rustc_span::Symbol], AcceptFn<T>)];
+type AcceptMapping<T> = &'static [(&'static [Symbol], AcceptFn<T>)];
 
 /// An [`AttributeParser`] is a type which searches for syntactic attributes.
 ///
@@ -72,7 +72,7 @@ pub(crate) trait AttributeParser: Default + 'static {
 /// [`SingleAttributeParser`] can only convert attributes one-to-one, and cannot combine multiple
 /// attributes together like is necessary for `#[stable()]` and `#[unstable()]` for example.
 pub(crate) trait SingleAttributeParser: 'static {
-    const PATH: &'static [rustc_span::Symbol];
+    const PATH: &'static [Symbol];
 
     /// Caled when a duplicate attribute is found.
     ///
@@ -119,7 +119,7 @@ type ConvertFn<E> = fn(ThinVec<E>) -> AttributeKind;
 /// [`CombineAttributeParser`] can only convert a single kind of attribute, and cannot combine multiple
 /// attributes together like is necessary for `#[stable()]` and `#[unstable()]` for example.
 pub(crate) trait CombineAttributeParser: 'static {
-    const PATH: &'static [rustc_span::Symbol];
+    const PATH: &'static [Symbol];
 
     type Item;
     const CONVERT: ConvertFn<Self::Item>;
diff --git a/compiler/rustc_attr_parsing/src/attributes/repr.rs b/compiler/rustc_attr_parsing/src/attributes/repr.rs
index 43dfb85a7c411..ab523ce0038da 100644
--- a/compiler/rustc_attr_parsing/src/attributes/repr.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/repr.rs
@@ -1,7 +1,7 @@
 use rustc_abi::Align;
 use rustc_ast::{IntTy, LitIntType, LitKind, UintTy};
 use rustc_attr_data_structures::{AttributeKind, IntType, ReprAttr};
-use rustc_span::{Span, Symbol, sym};
+use rustc_span::{DUMMY_SP, Span, Symbol, sym};
 
 use super::{CombineAttributeParser, ConvertFn};
 use crate::context::AcceptContext;
@@ -21,7 +21,7 @@ pub(crate) struct ReprParser;
 
 impl CombineAttributeParser for ReprParser {
     type Item = (ReprAttr, Span);
-    const PATH: &'static [rustc_span::Symbol] = &[sym::repr];
+    const PATH: &'static [Symbol] = &[sym::repr];
     const CONVERT: ConvertFn<Self::Item> = AttributeKind::Repr;
 
     fn extend<'a>(
@@ -99,7 +99,7 @@ fn parse_repr(cx: &AcceptContext<'_>, param: &MetaItemParser<'_>) -> Option<Repr
     let (name, ident_span) = if let Some(ident) = param.path_without_args().word() {
         (Some(ident.name), ident.span)
     } else {
-        (None, rustc_span::DUMMY_SP)
+        (None, DUMMY_SP)
     };
 
     let args = param.args();
diff --git a/compiler/rustc_attr_parsing/src/attributes/stability.rs b/compiler/rustc_attr_parsing/src/attributes/stability.rs
index cd1f21d92e7e2..e30d7e7238eec 100644
--- a/compiler/rustc_attr_parsing/src/attributes/stability.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/stability.rs
@@ -117,7 +117,7 @@ impl AttributeParser for BodyStabilityParser {
 pub(crate) struct ConstStabilityIndirectParser;
 // FIXME(jdonszelmann): single word attribute group when we have these
 impl SingleAttributeParser for ConstStabilityIndirectParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_const_stable_indirect];
+    const PATH: &'static [Symbol] = &[sym::rustc_const_stable_indirect];
 
     // ignore
     fn on_duplicate(_cx: &AcceptContext<'_>, _first_span: Span) {}
diff --git a/compiler/rustc_attr_parsing/src/attributes/transparency.rs b/compiler/rustc_attr_parsing/src/attributes/transparency.rs
index ce42b0507ed57..d229fc0974010 100644
--- a/compiler/rustc_attr_parsing/src/attributes/transparency.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/transparency.rs
@@ -1,6 +1,6 @@
 use rustc_attr_data_structures::AttributeKind;
 use rustc_span::hygiene::Transparency;
-use rustc_span::sym;
+use rustc_span::{Span, Symbol, sym};
 
 use super::{AcceptContext, SingleAttributeParser};
 use crate::parser::ArgParser;
@@ -11,9 +11,9 @@ pub(crate) struct TransparencyParser;
 #[allow(rustc::untranslatable_diagnostic)]
 #[allow(rustc::diagnostic_outside_of_impl)]
 impl SingleAttributeParser for TransparencyParser {
-    const PATH: &'static [rustc_span::Symbol] = &[sym::rustc_macro_transparency];
+    const PATH: &'static [Symbol] = &[sym::rustc_macro_transparency];
 
-    fn on_duplicate(cx: &crate::context::AcceptContext<'_>, first_span: rustc_span::Span) {
+    fn on_duplicate(cx: &crate::context::AcceptContext<'_>, first_span: Span) {
         cx.dcx().span_err(vec![first_span, cx.attr_span], "multiple macro transparency attributes");
     }
 
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 55c3df003fe16..1360fc6871422 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -26,12 +26,16 @@ macro_rules! attribute_groups {
     (
         pub(crate) static $name: ident = [$($names: ty),* $(,)?];
     ) => {
-        pub(crate) static $name: LazyLock<(
-            BTreeMap<&'static [Symbol], Vec<Box<dyn Fn(&AcceptContext<'_>, &ArgParser<'_>) + Send + Sync>>>,
-            Vec<Box<dyn Send + Sync + Fn(&FinalizeContext<'_>) -> Option<AttributeKind>>>
-        )> = LazyLock::new(|| {
-            let mut accepts = BTreeMap::<_, Vec<Box<dyn Fn(&AcceptContext<'_>, &ArgParser<'_>) + Send + Sync>>>::new();
-            let mut finalizes = Vec::<Box<dyn Send + Sync + Fn(&FinalizeContext<'_>) -> Option<AttributeKind>>>::new();
+        type Accepts = BTreeMap<
+            &'static [Symbol],
+            Box<dyn Send + Sync + Fn(&AcceptContext<'_>, &ArgParser<'_>)>
+        >;
+        type Finalizes = Vec<
+            Box<dyn Send + Sync + Fn(&FinalizeContext<'_>) -> Option<AttributeKind>>
+        >;
+        pub(crate) static $name: LazyLock<(Accepts, Finalizes)> = LazyLock::new(|| {
+            let mut accepts = Accepts::new();
+            let mut finalizes = Finalizes::new();
             $(
                 {
                     thread_local! {
@@ -39,11 +43,12 @@ macro_rules! attribute_groups {
                     };
 
                     for (k, v) in <$names>::ATTRIBUTES {
-                        accepts.entry(*k).or_default().push(Box::new(|cx, args| {
+                        let old = accepts.insert(*k, Box::new(|cx, args| {
                             STATE_OBJECT.with_borrow_mut(|s| {
                                 v(s, cx, args)
                             })
                         }));
+                        assert!(old.is_none());
                     }
 
                     finalizes.push(Box::new(|cx| {
@@ -110,7 +115,8 @@ impl<'a> Deref for AcceptContext<'a> {
 
 /// Context given to every attribute parser during finalization.
 ///
-/// Gives [`AttributeParser`](crate::attributes::AttributeParser)s enough information to create errors, for example.
+/// Gives [`AttributeParser`](crate::attributes::AttributeParser)s enough information to create
+/// errors, for example.
 pub(crate) struct FinalizeContext<'a> {
     /// The parse context, gives access to the session and the
     /// diagnostics context.
@@ -141,10 +147,9 @@ pub struct AttributeParser<'sess> {
     sess: &'sess Session,
     features: Option<&'sess Features>,
 
-    /// *only* parse attributes with this symbol.
+    /// *Only* parse attributes with this symbol.
     ///
-    /// Used in cases where we want the lowering infrastructure for
-    /// parse just a single attribute.
+    /// Used in cases where we want the lowering infrastructure for parse just a single attribute.
     parse_only: Option<Symbol>,
 
     /// Can be used to instruct parsers to reduce the number of diagnostics it emits.
@@ -157,9 +162,9 @@ impl<'sess> AttributeParser<'sess> {
     /// One example where this is necessary, is to parse `feature` attributes themselves for
     /// example.
     ///
-    /// Try to use this as little as possible. Attributes *should* be lowered during `rustc_ast_lowering`.
-    /// Some attributes require access to features to parse, which would crash if you tried to do so
-    /// through [`parse_limited`](Self::parse_limited).
+    /// Try to use this as little as possible. Attributes *should* be lowered during
+    /// `rustc_ast_lowering`. Some attributes require access to features to parse, which would
+    /// crash if you tried to do so through [`parse_limited`](Self::parse_limited).
     ///
     /// To make sure use is limited, supply a `Symbol` you'd like to parse. Only attributes with
     /// that symbol are picked out of the list of instructions and parsed. Those are returned.
@@ -217,19 +222,18 @@ impl<'sess> AttributeParser<'sess> {
         let group_cx = FinalizeContext { cx: self, target_span };
 
         for attr in attrs {
-            // if we're only looking for a single attribute,
-            // skip all the ones we don't care about
+            // If we're only looking for a single attribute, skip all the ones we don't care about.
             if let Some(expected) = self.parse_only {
                 if !attr.has_name(expected) {
                     continue;
                 }
             }
 
-            // sometimes, for example for `#![doc = include_str!("readme.md")]`,
+            // Sometimes, for example for `#![doc = include_str!("readme.md")]`,
             // doc still contains a non-literal. You might say, when we're lowering attributes
             // that's expanded right? But no, sometimes, when parsing attributes on macros,
             // we already use the lowering logic and these are still there. So, when `omit_doc`
-            // is set we *also* want to ignore these
+            // is set we *also* want to ignore these.
             if omit_doc == OmitDoc::Skip && attr.has_name(sym::doc) {
                 continue;
             }
@@ -263,21 +267,17 @@ impl<'sess> AttributeParser<'sess> {
                     let (path, args) = parser.deconstruct();
                     let parts = path.segments().map(|i| i.name).collect::<Vec<_>>();
 
-                    if let Some(accepts) = ATTRIBUTE_MAPPING.0.get(parts.as_slice()) {
-                        for f in accepts {
-                            let cx = AcceptContext {
-                                group_cx: &group_cx,
-                                attr_span: lower_span(attr.span),
-                            };
+                    if let Some(accept) = ATTRIBUTE_MAPPING.0.get(parts.as_slice()) {
+                        let cx =
+                            AcceptContext { group_cx: &group_cx, attr_span: lower_span(attr.span) };
 
-                            f(&cx, &args)
-                        }
+                        accept(&cx, &args)
                     } else {
-                        // if we're here, we must be compiling a tool attribute... Or someone forgot to
-                        // parse their fancy new attribute. Let's warn them in any case. If you are that
-                        // person, and you really your attribute should remain unparsed, carefully read the
-                        // documentation in this module and if you still think so you can add an exception
-                        // to this assertion.
+                        // If we're here, we must be compiling a tool attribute... Or someone
+                        // forgot to parse their fancy new attribute. Let's warn them in any case.
+                        // If you are that person, and you really think your attribute should
+                        // remain unparsed, carefully read the documentation in this module and if
+                        // you still think so you can add an exception to this assertion.
 
                         // FIXME(jdonszelmann): convert other attributes, and check with this that
                         // we caught em all
diff --git a/compiler/rustc_attr_parsing/src/parser.rs b/compiler/rustc_attr_parsing/src/parser.rs
index 077d953cfa318..f433d3574e186 100644
--- a/compiler/rustc_attr_parsing/src/parser.rs
+++ b/compiler/rustc_attr_parsing/src/parser.rs
@@ -12,8 +12,7 @@ use rustc_ast::{AttrArgs, DelimArgs, Expr, ExprKind, LitKind, MetaItemLit, Norma
 use rustc_ast_pretty::pprust;
 use rustc_errors::DiagCtxtHandle;
 use rustc_hir::{self as hir, AttrPath};
-use rustc_span::symbol::{Ident, kw, sym};
-use rustc_span::{ErrorGuaranteed, Span, Symbol};
+use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 
 pub struct SegmentIterator<'a> {
     offset: usize,
diff --git a/compiler/rustc_const_eval/messages.ftl b/compiler/rustc_const_eval/messages.ftl
index f4defd2aa1343..7d4afc9d3d952 100644
--- a/compiler/rustc_const_eval/messages.ftl
+++ b/compiler/rustc_const_eval/messages.ftl
@@ -424,8 +424,7 @@ const_eval_unstable_in_stable_exposed =
     .unstable_sugg = if the {$is_function_call2 ->
             [true] caller
             *[false] function
-        } is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
-    .bypass_sugg = otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+        } is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
 
 const_eval_unstable_intrinsic = `{$name}` is not yet stable as a const intrinsic
 const_eval_unstable_intrinsic_suggestion = add `#![feature({$feature})]` to the crate attributes to enable
diff --git a/compiler/rustc_const_eval/src/errors.rs b/compiler/rustc_const_eval/src/errors.rs
index 826ea0e58ecca..7c35e47bbf805 100644
--- a/compiler/rustc_const_eval/src/errors.rs
+++ b/compiler/rustc_const_eval/src/errors.rs
@@ -58,11 +58,6 @@ pub(crate) struct UnstableInStableExposed {
         code = "#[rustc_const_unstable(feature = \"...\", issue = \"...\")]\n",
         applicability = "has-placeholders"
     )]
-    #[suggestion(
-        const_eval_bypass_sugg,
-        code = "#[rustc_allow_const_fn_unstable({gate})]\n",
-        applicability = "has-placeholders"
-    )]
     pub attr_span: Span,
 }
 
diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index e505e2280953e..06161cb6c7ce5 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -1173,6 +1173,7 @@ impl str {
     /// The iterator returned will return string slices that are sub-slices of
     /// the original string slice, separated by any amount of ASCII whitespace.
     ///
+    /// This uses the same definition as [`char::is_ascii_whitespace`].
     /// To split by Unicode `Whitespace` instead, use [`split_whitespace`].
     ///
     /// [`split_whitespace`]: str::split_whitespace
@@ -1191,7 +1192,8 @@ impl str {
     /// assert_eq!(None, iter.next());
     /// ```
     ///
-    /// All kinds of ASCII whitespace are considered:
+    /// Various kinds of ASCII whitespace are considered
+    /// (see [`char::is_ascii_whitespace`]):
     ///
     /// ```
     /// let mut iter = " Mary   had\ta little  \n\t lamb".split_ascii_whitespace();
diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index ead4877512727..b0580b467be68 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -594,9 +594,9 @@ impl OsString {
     /// The slice must be valid for the platform encoding (as described in
     /// [`OsStr::from_encoded_bytes_unchecked`]).
     ///
-    /// This bypasses the encoding-dependent surrogate joining, so `self` must
-    /// not end with a leading surrogate half and `other` must not start with
-    /// with a trailing surrogate half.
+    /// This bypasses the encoding-dependent surrogate joining, so either
+    /// `self` must not end with a leading surrogate half, or `other` must not
+    /// start with a trailing surrogate half.
     #[inline]
     pub(crate) unsafe fn extend_from_slice_unchecked(&mut self, other: &[u8]) {
         // SAFETY: Guaranteed by caller.
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index 509e673bdb8b9..8047c0c03ad4f 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -2803,8 +2803,8 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// Recursively create a directory and all of its parent components if they
 /// are missing.
 ///
-/// If this function returns an error, some of the parent components might have
-/// been created already.
+/// This function is not atomic. If it returns an error, any parent components it was able to create
+/// will remain.
 ///
 /// If the empty path is passed to this function, it always succeeds without
 /// creating any directories.
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 7959c63385816..2cdded1dfcf99 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -2154,6 +2154,13 @@ pub struct Path {
 #[stable(since = "1.7.0", feature = "strip_prefix")]
 pub struct StripPrefixError(());
 
+/// An error returned from [`Path::normalize_lexically`] if a `..` parent reference
+/// would escape the path.
+#[unstable(feature = "normalize_lexically", issue = "134694")]
+#[derive(Debug, PartialEq)]
+#[non_exhaustive]
+pub struct NormalizeError;
+
 impl Path {
     // The following (private!) function allows construction of a path from a u8
     // slice, which is only safe when it is known to follow the OsStr encoding.
@@ -2961,6 +2968,67 @@ impl Path {
         fs::canonicalize(self)
     }
 
+    /// Normalize a path, including `..` without traversing the filesystem.
+    ///
+    /// Returns an error if normalization would leave leading `..` components.
+    ///
+    /// <div class="warning">
+    ///
+    /// This function always resolves `..` to the "lexical" parent.
+    /// That is "a/b/../c" will always resolve to `a/c` which can change the meaning of the path.
+    /// In particular, `a/c` and `a/b/../c` are distinct on many systems because `b` may be a symbolic link, so its parent isn’t `a`.
+    ///
+    /// </div>
+    ///
+    /// [`path::absolute`](absolute) is an alternative that preserves `..`.
+    /// Or [`Path::canonicalize`] can be used to resolve any `..` by querying the filesystem.
+    #[unstable(feature = "normalize_lexically", issue = "134694")]
+    pub fn normalize_lexically(&self) -> Result<PathBuf, NormalizeError> {
+        let mut lexical = PathBuf::new();
+        let mut iter = self.components().peekable();
+
+        // Find the root, if any, and add it to the lexical path.
+        // Here we treat the Windows path "C:\" as a single "root" even though
+        // `components` splits it into two: (Prefix, RootDir).
+        let root = match iter.peek() {
+            Some(Component::ParentDir) => return Err(NormalizeError),
+            Some(p @ Component::RootDir) | Some(p @ Component::CurDir) => {
+                lexical.push(p);
+                iter.next();
+                lexical.as_os_str().len()
+            }
+            Some(Component::Prefix(prefix)) => {
+                lexical.push(prefix.as_os_str());
+                iter.next();
+                if let Some(p @ Component::RootDir) = iter.peek() {
+                    lexical.push(p);
+                    iter.next();
+                }
+                lexical.as_os_str().len()
+            }
+            None => return Ok(PathBuf::new()),
+            Some(Component::Normal(_)) => 0,
+        };
+
+        for component in iter {
+            match component {
+                Component::RootDir => unreachable!(),
+                Component::Prefix(_) => return Err(NormalizeError),
+                Component::CurDir => continue,
+                Component::ParentDir => {
+                    // It's an error if ParentDir causes us to go above the "root".
+                    if lexical.as_os_str().len() == root {
+                        return Err(NormalizeError);
+                    } else {
+                        lexical.pop();
+                    }
+                }
+                Component::Normal(path) => lexical.push(path),
+            }
+        }
+        Ok(lexical)
+    }
+
     /// Reads a symbolic link, returning the file that the link points to.
     ///
     /// This is an alias to [`fs::read_link`].
@@ -3502,6 +3570,15 @@ impl Error for StripPrefixError {
     }
 }
 
+#[unstable(feature = "normalize_lexically", issue = "134694")]
+impl fmt::Display for NormalizeError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("parent reference `..` points outside of base directory")
+    }
+}
+#[unstable(feature = "normalize_lexically", issue = "134694")]
+impl Error for NormalizeError {}
+
 /// Makes the path absolute without accessing the filesystem.
 ///
 /// If the path is relative, the current directory is used as the base directory.
diff --git a/library/std/src/sys/os_str/wtf8.rs b/library/std/src/sys/os_str/wtf8.rs
index 5174ea65d0cd9..892bd2e3de659 100644
--- a/library/std/src/sys/os_str/wtf8.rs
+++ b/library/std/src/sys/os_str/wtf8.rs
@@ -215,9 +215,9 @@ impl Buf {
     /// The slice must be valid for the platform encoding (as described in
     /// [`Slice::from_encoded_bytes_unchecked`]).
     ///
-    /// This bypasses the WTF-8 surrogate joining, so `self` must not end with a
-    /// leading surrogate half and `other` must not start with with a trailing
-    /// surrogate half.
+    /// This bypasses the WTF-8 surrogate joining, so either `self` must not
+    /// end with a leading surrogate half, or `other` must not start with a
+    /// trailing surrogate half.
     #[inline]
     pub unsafe fn extend_from_slice_unchecked(&mut self, other: &[u8]) {
         self.inner.extend_from_slice(other);
diff --git a/library/std/tests/path.rs b/library/std/tests/path.rs
index 87e0d226cbd31..781855a2d14aa 100644
--- a/library/std/tests/path.rs
+++ b/library/std/tests/path.rs
@@ -3,7 +3,8 @@
     path_add_extension,
     path_file_prefix,
     maybe_uninit_slice,
-    os_string_pathbuf_leak
+    os_string_pathbuf_leak,
+    normalize_lexically
 )]
 
 use std::clone::CloneToUninit;
@@ -2007,3 +2008,56 @@ fn test_embedded_newline() {
     assert_eq!(path.file_name(), Some(OsStr::new("foo\nbar")));
     assert_eq!(path.to_str(), Some("foo\nbar"));
 }
+
+#[test]
+fn normalize_lexically() {
+    #[track_caller]
+    fn check_ok(a: &str, b: &str) {
+        assert_eq!(Path::new(a).normalize_lexically().unwrap(), PathBuf::from(b));
+    }
+
+    #[track_caller]
+    fn check_err(a: &str) {
+        assert!(Path::new(a).normalize_lexically().is_err());
+    }
+
+    // Relative paths
+    check_ok("a", "a");
+    check_ok("./a", "./a");
+    check_ok("a/b/c", "a/b/c");
+    check_ok("a/././b/./c/.", "a/b/c");
+    check_ok("a/../c", "c");
+    check_ok("./a/b", "./a/b");
+    check_ok("a/../b/c/..", "b");
+
+    check_err("..");
+    check_err("../..");
+    check_err("a/../..");
+    check_err("a/../../b");
+    check_err("a/../../b/c");
+    check_err("a/../b/../..");
+
+    // Check we don't escape the root or prefix
+    #[cfg(unix)]
+    {
+        check_err("/..");
+        check_err("/a/../..");
+    }
+    #[cfg(windows)]
+    {
+        check_err(r"C:\..");
+        check_err(r"C:\a\..\..");
+
+        check_err(r"C:..");
+        check_err(r"C:a\..\..");
+
+        check_err(r"\\server\share\..");
+        check_err(r"\\server\share\a\..\..");
+
+        check_err(r"\..");
+        check_err(r"\a\..\..");
+
+        check_err(r"\\?\UNC\server\share\..");
+        check_err(r"\\?\UNC\server\share\a\..\..");
+    }
+}
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 2daa862460534..1d175bd97e6a1 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -123,7 +123,7 @@ pr:
       DOCKER_SCRIPT: x86_64-gnu-llvm.sh
     <<: *job-linux-16c
   - name: x86_64-gnu-tools
-    <<: *job-linux-16c
+    <<: *job-linux-36c-codebuild
 
 # Jobs that run when you perform a try build (@bors try)
 # These jobs automatically inherit envs.try, to avoid repeating
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 07ecd98f77596..bb3469867d51e 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -610,6 +610,9 @@ impl Item {
             UnionItem(ref union_) => Some(union_.has_stripped_entries()),
             EnumItem(ref enum_) => Some(enum_.has_stripped_entries()),
             VariantItem(ref v) => v.has_stripped_entries(),
+            TypeAliasItem(ref type_alias) => {
+                type_alias.inner_type.as_ref().and_then(|t| t.has_stripped_entries())
+            }
             _ => None,
         }
     }
@@ -761,14 +764,11 @@ impl Item {
         Some(tcx.visibility(def_id))
     }
 
-    pub(crate) fn attributes(&self, tcx: TyCtxt<'_>, cache: &Cache, is_json: bool) -> Vec<String> {
+    pub(crate) fn attributes_without_repr(&self, tcx: TyCtxt<'_>, is_json: bool) -> Vec<String> {
         const ALLOWED_ATTRIBUTES: &[Symbol] =
             &[sym::export_name, sym::link_section, sym::no_mangle, sym::non_exhaustive];
 
-        use rustc_abi::IntegerType;
-
-        let mut attrs: Vec<String> = self
-            .attrs
+        self.attrs
             .other_attrs
             .iter()
             .filter_map(|attr| {
@@ -796,74 +796,28 @@ impl Item {
                     None
                 }
             })
-            .collect();
+            .collect()
+    }
 
-        // Add #[repr(...)]
-        if let Some(def_id) = self.def_id()
-            && let ItemType::Struct | ItemType::Enum | ItemType::Union = self.type_()
-        {
-            let adt = tcx.adt_def(def_id);
-            let repr = adt.repr();
-            let mut out = Vec::new();
-            if repr.c() {
-                out.push("C");
-            }
-            if repr.transparent() {
-                // Render `repr(transparent)` iff the non-1-ZST field is public or at least one
-                // field is public in case all fields are 1-ZST fields.
-                let render_transparent = is_json
-                    || cache.document_private
-                    || adt
-                        .all_fields()
-                        .find(|field| {
-                            let ty =
-                                field.ty(tcx, ty::GenericArgs::identity_for_item(tcx, field.did));
-                            tcx.layout_of(
-                                ty::TypingEnv::post_analysis(tcx, field.did).as_query_input(ty),
-                            )
-                            .is_ok_and(|layout| !layout.is_1zst())
-                        })
-                        .map_or_else(
-                            || adt.all_fields().any(|field| field.vis.is_public()),
-                            |field| field.vis.is_public(),
-                        );
+    pub(crate) fn attributes_and_repr(
+        &self,
+        tcx: TyCtxt<'_>,
+        cache: &Cache,
+        is_json: bool,
+    ) -> Vec<String> {
+        let mut attrs = self.attributes_without_repr(tcx, is_json);
 
-                if render_transparent {
-                    out.push("transparent");
-                }
-            }
-            if repr.simd() {
-                out.push("simd");
-            }
-            let pack_s;
-            if let Some(pack) = repr.pack {
-                pack_s = format!("packed({})", pack.bytes());
-                out.push(&pack_s);
-            }
-            let align_s;
-            if let Some(align) = repr.align {
-                align_s = format!("align({})", align.bytes());
-                out.push(&align_s);
-            }
-            let int_s;
-            if let Some(int) = repr.int {
-                int_s = match int {
-                    IntegerType::Pointer(is_signed) => {
-                        format!("{}size", if is_signed { 'i' } else { 'u' })
-                    }
-                    IntegerType::Fixed(size, is_signed) => {
-                        format!("{}{}", if is_signed { 'i' } else { 'u' }, size.size().bytes() * 8)
-                    }
-                };
-                out.push(&int_s);
-            }
-            if !out.is_empty() {
-                attrs.push(format!("#[repr({})]", out.join(", ")));
-            }
+        if let Some(repr_attr) = self.repr(tcx, cache, is_json) {
+            attrs.push(repr_attr);
         }
         attrs
     }
 
+    /// Returns a stringified `#[repr(...)]` attribute.
+    pub(crate) fn repr(&self, tcx: TyCtxt<'_>, cache: &Cache, is_json: bool) -> Option<String> {
+        repr_attributes(tcx, cache, self.def_id()?, self.type_(), is_json)
+    }
+
     pub fn is_doc_hidden(&self) -> bool {
         self.attrs.is_doc_hidden()
     }
@@ -873,6 +827,73 @@ impl Item {
     }
 }
 
+pub(crate) fn repr_attributes(
+    tcx: TyCtxt<'_>,
+    cache: &Cache,
+    def_id: DefId,
+    item_type: ItemType,
+    is_json: bool,
+) -> Option<String> {
+    use rustc_abi::IntegerType;
+
+    if !matches!(item_type, ItemType::Struct | ItemType::Enum | ItemType::Union) {
+        return None;
+    }
+    let adt = tcx.adt_def(def_id);
+    let repr = adt.repr();
+    let mut out = Vec::new();
+    if repr.c() {
+        out.push("C");
+    }
+    if repr.transparent() {
+        // Render `repr(transparent)` iff the non-1-ZST field is public or at least one
+        // field is public in case all fields are 1-ZST fields.
+        let render_transparent = cache.document_private
+            || is_json
+            || adt
+                .all_fields()
+                .find(|field| {
+                    let ty = field.ty(tcx, ty::GenericArgs::identity_for_item(tcx, field.did));
+                    tcx.layout_of(ty::TypingEnv::post_analysis(tcx, field.did).as_query_input(ty))
+                        .is_ok_and(|layout| !layout.is_1zst())
+                })
+                .map_or_else(
+                    || adt.all_fields().any(|field| field.vis.is_public()),
+                    |field| field.vis.is_public(),
+                );
+
+        if render_transparent {
+            out.push("transparent");
+        }
+    }
+    if repr.simd() {
+        out.push("simd");
+    }
+    let pack_s;
+    if let Some(pack) = repr.pack {
+        pack_s = format!("packed({})", pack.bytes());
+        out.push(&pack_s);
+    }
+    let align_s;
+    if let Some(align) = repr.align {
+        align_s = format!("align({})", align.bytes());
+        out.push(&align_s);
+    }
+    let int_s;
+    if let Some(int) = repr.int {
+        int_s = match int {
+            IntegerType::Pointer(is_signed) => {
+                format!("{}size", if is_signed { 'i' } else { 'u' })
+            }
+            IntegerType::Fixed(size, is_signed) => {
+                format!("{}{}", if is_signed { 'i' } else { 'u' }, size.size().bytes() * 8)
+            }
+        };
+        out.push(&int_s);
+    }
+    if !out.is_empty() { Some(format!("#[repr({})]", out.join(", "))) } else { None }
+}
+
 #[derive(Clone, Debug)]
 pub(crate) enum ItemKind {
     ExternCrateItem {
@@ -2107,7 +2128,7 @@ impl Enum {
         self.variants.iter().any(|f| f.is_stripped())
     }
 
-    pub(crate) fn variants(&self) -> impl Iterator<Item = &Item> {
+    pub(crate) fn non_stripped_variants(&self) -> impl Iterator<Item = &Item> {
         self.variants.iter().filter(|v| !v.is_stripped())
     }
 }
@@ -2345,6 +2366,17 @@ pub(crate) enum TypeAliasInnerType {
     Struct { ctor_kind: Option<CtorKind>, fields: Vec<Item> },
 }
 
+impl TypeAliasInnerType {
+    fn has_stripped_entries(&self) -> Option<bool> {
+        Some(match self {
+            Self::Enum { variants, .. } => variants.iter().any(|v| v.is_stripped()),
+            Self::Union { fields } | Self::Struct { fields, .. } => {
+                fields.iter().any(|f| f.is_stripped())
+            }
+        })
+    }
+}
+
 #[derive(Clone, Debug)]
 pub(crate) struct TypeAlias {
     pub(crate) type_: Type,
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 06cb9269cc87f..5677b13033db5 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -1194,18 +1194,36 @@ fn render_assoc_item(
 // a whitespace prefix and newline.
 fn render_attributes_in_pre(it: &clean::Item, prefix: &str, cx: &Context<'_>) -> impl fmt::Display {
     fmt::from_fn(move |f| {
-        for a in it.attributes(cx.tcx(), cx.cache(), false) {
+        for a in it.attributes_and_repr(cx.tcx(), cx.cache(), false) {
             writeln!(f, "{prefix}{a}")?;
         }
         Ok(())
     })
 }
 
+struct CodeAttribute(String);
+
+fn render_code_attribute(code_attr: CodeAttribute, w: &mut impl fmt::Write) {
+    write!(w, "<div class=\"code-attribute\">{}</div>", code_attr.0).unwrap();
+}
+
 // When an attribute is rendered inside a <code> tag, it is formatted using
 // a div to produce a newline after it.
 fn render_attributes_in_code(w: &mut impl fmt::Write, it: &clean::Item, cx: &Context<'_>) {
-    for attr in it.attributes(cx.tcx(), cx.cache(), false) {
-        write!(w, "<div class=\"code-attribute\">{attr}</div>").unwrap();
+    for attr in it.attributes_and_repr(cx.tcx(), cx.cache(), false) {
+        render_code_attribute(CodeAttribute(attr), w);
+    }
+}
+
+/// used for type aliases to only render their `repr` attribute.
+fn render_repr_attributes_in_code(
+    w: &mut impl fmt::Write,
+    cx: &Context<'_>,
+    def_id: DefId,
+    item_type: ItemType,
+) {
+    if let Some(repr) = clean::repr_attributes(cx.tcx(), cx.cache(), def_id, item_type, false) {
+        render_code_attribute(CodeAttribute(repr), w);
     }
 }
 
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index 39a631b637bd4..b4663961c1b71 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -20,7 +20,7 @@ use super::{
     collect_paths_for_type, document, ensure_trailing_slash, get_filtered_impls_for_reference,
     item_ty_to_section, notable_traits_button, notable_traits_json, render_all_impls,
     render_assoc_item, render_assoc_items, render_attributes_in_code, render_attributes_in_pre,
-    render_impl, render_rightside, render_stability_since_raw,
+    render_impl, render_repr_attributes_in_code, render_rightside, render_stability_since_raw,
     render_stability_since_raw_with_extra, write_section_heading,
 };
 use crate::clean;
@@ -1278,94 +1278,58 @@ fn item_type_alias(cx: &Context<'_>, it: &clean::Item, t: &clean::TypeAlias) ->
 
             match inner_type {
                 clean::TypeAliasInnerType::Enum { variants, is_non_exhaustive } => {
-                    let variants_iter = || variants.iter().filter(|i| !i.is_stripped());
                     let ty = cx.tcx().type_of(it.def_id().unwrap()).instantiate_identity();
                     let enum_def_id = ty.ty_adt_def().unwrap().did();
 
-                    wrap_item(w, |w| {
-                        let variants_len = variants.len();
-                        let variants_count = variants_iter().count();
-                        let has_stripped_entries = variants_len != variants_count;
-
-                        write!(
-                            w,
-                            "enum {}{}{}",
-                            it.name.unwrap(),
-                            t.generics.print(cx),
-                            render_enum_fields(
-                                cx,
-                                Some(&t.generics),
-                                variants,
-                                variants_count,
-                                has_stripped_entries,
-                                *is_non_exhaustive,
-                                enum_def_id,
-                            )
-                        )
-                    })?;
-                    write!(w, "{}", item_variants(cx, it, variants, enum_def_id))?;
+                    DisplayEnum {
+                        variants,
+                        generics: &t.generics,
+                        is_non_exhaustive: *is_non_exhaustive,
+                        def_id: enum_def_id,
+                    }
+                    .render_into(cx, it, true, w)?;
                 }
                 clean::TypeAliasInnerType::Union { fields } => {
-                    wrap_item(w, |w| {
-                        let fields_count = fields.iter().filter(|i| !i.is_stripped()).count();
-                        let has_stripped_fields = fields.len() != fields_count;
+                    let ty = cx.tcx().type_of(it.def_id().unwrap()).instantiate_identity();
+                    let union_def_id = ty.ty_adt_def().unwrap().did();
 
-                        write!(
-                            w,
-                            "union {}{}{}",
-                            it.name.unwrap(),
-                            t.generics.print(cx),
-                            render_struct_fields(
-                                Some(&t.generics),
-                                None,
-                                fields,
-                                "",
-                                true,
-                                has_stripped_fields,
-                                cx,
-                            ),
-                        )
-                    })?;
-                    write!(w, "{}", item_fields(cx, it, fields, None))?;
+                    ItemUnion {
+                        cx,
+                        it,
+                        fields,
+                        generics: &t.generics,
+                        is_type_alias: true,
+                        def_id: union_def_id,
+                    }
+                    .render_into(w)?;
                 }
                 clean::TypeAliasInnerType::Struct { ctor_kind, fields } => {
-                    wrap_item(w, |w| {
-                        let fields_count = fields.iter().filter(|i| !i.is_stripped()).count();
-                        let has_stripped_fields = fields.len() != fields_count;
+                    let ty = cx.tcx().type_of(it.def_id().unwrap()).instantiate_identity();
+                    let struct_def_id = ty.ty_adt_def().unwrap().did();
 
-                        write!(
-                            w,
-                            "struct {}{}{}",
-                            it.name.unwrap(),
-                            t.generics.print(cx),
-                            render_struct_fields(
-                                Some(&t.generics),
-                                *ctor_kind,
-                                fields,
-                                "",
-                                true,
-                                has_stripped_fields,
-                                cx,
-                            ),
-                        )
-                    })?;
-                    write!(w, "{}", item_fields(cx, it, fields, None))?;
+                    DisplayStruct {
+                        ctor_kind: *ctor_kind,
+                        generics: &t.generics,
+                        fields,
+                        def_id: struct_def_id,
+                    }
+                    .render_into(cx, it, true, w)?;
                 }
             }
+        } else {
+            let def_id = it.item_id.expect_def_id();
+            // Render any items associated directly to this alias, as otherwise they
+            // won't be visible anywhere in the docs. It would be nice to also show
+            // associated items from the aliased type (see discussion in #32077), but
+            // we need #14072 to make sense of the generics.
+            write!(
+                w,
+                "{}{}",
+                render_assoc_items(cx, it, def_id, AssocItemRender::All),
+                document_type_layout(cx, def_id)
+            )?;
         }
 
-        let def_id = it.item_id.expect_def_id();
-        // Render any items associated directly to this alias, as otherwise they
-        // won't be visible anywhere in the docs. It would be nice to also show
-        // associated items from the aliased type (see discussion in #32077), but
-        // we need #14072 to make sense of the generics.
-        write!(
-            w,
-            "{}{}",
-            render_assoc_items(cx, it, def_id, AssocItemRender::All),
-            document_type_layout(cx, def_id)
-        )?;
-
         // [RUSTDOCIMPL] type.impl
         //
         // Include type definitions from the alias target type.
@@ -1463,50 +1427,83 @@ fn item_type_alias(cx: &Context<'_>, it: &clean::Item, t: &clean::TypeAlias) ->
     })
 }
 
-fn item_union(cx: &Context<'_>, it: &clean::Item, s: &clean::Union) -> impl fmt::Display {
-    item_template!(
-        #[template(path = "item_union.html")]
-        struct ItemUnion<'a, 'cx> {
-            cx: &'a Context<'cx>,
-            it: &'a clean::Item,
-            s: &'a clean::Union,
-        },
-        methods = [document, document_type_layout, render_attributes_in_pre, render_assoc_items]
-    );
+item_template!(
+    #[template(path = "item_union.html")]
+    struct ItemUnion<'a, 'cx> {
+        cx: &'a Context<'cx>,
+        it: &'a clean::Item,
+        fields: &'a [clean::Item],
+        generics: &'a clean::Generics,
+        is_type_alias: bool,
+        def_id: DefId,
+    },
+    methods = [document, document_type_layout, render_assoc_items]
+);
+
+impl<'a, 'cx: 'a> ItemUnion<'a, 'cx> {
+    fn render_union(&self) -> impl Display {
+        render_union(self.it, Some(&self.generics), &self.fields, self.cx)
+    }
 
-    impl<'a, 'cx: 'a> ItemUnion<'a, 'cx> {
-        fn render_union(&self) -> impl Display {
-            render_union(self.it, Some(&self.s.generics), &self.s.fields, self.cx)
-        }
+    fn document_field(&self, field: &'a clean::Item) -> impl Display {
+        document(self.cx, field, Some(self.it), HeadingOffset::H3)
+    }
 
-        fn document_field(&self, field: &'a clean::Item) -> impl Display {
-            document(self.cx, field, Some(self.it), HeadingOffset::H3)
-        }
+    fn stability_field(&self, field: &clean::Item) -> Option<String> {
+        field.stability_class(self.cx.tcx())
+    }
 
-        fn stability_field(&self, field: &clean::Item) -> Option<String> {
-            field.stability_class(self.cx.tcx())
-        }
+    fn print_ty(&self, ty: &'a clean::Type) -> impl Display {
+        ty.print(self.cx)
+    }
 
-        fn print_ty(&self, ty: &'a clean::Type) -> impl Display {
-            ty.print(self.cx)
-        }
+    // FIXME (GuillaumeGomez): When <https://github.com/askama-rs/askama/issues/452> is implemented,
+    // we can replace the returned value with:
+    //
+    // `iter::Peekable<impl Iterator<Item = (&'a clean::Item, &'a clean::Type)>>`
+    //
+    // And update `item_union.html`.
+    fn fields_iter(&self) -> impl Iterator<Item = (&'a clean::Item, &'a clean::Type)> {
+        self.fields.iter().filter_map(|f| match f.kind {
+            clean::StructFieldItem(ref ty) => Some((f, ty)),
+            _ => None,
+        })
+    }
 
-        fn fields_iter(
-            &self,
-        ) -> iter::Peekable<impl Iterator<Item = (&'a clean::Item, &'a clean::Type)>> {
-            self.s
-                .fields
-                .iter()
-                .filter_map(|f| match f.kind {
-                    clean::StructFieldItem(ref ty) => Some((f, ty)),
-                    _ => None,
-                })
-                .peekable()
-        }
+    fn render_attributes_in_pre(&self) -> impl fmt::Display {
+        fmt::from_fn(move |f| {
+            if self.is_type_alias {
+                // For now the only attributes we render for type aliases are `repr` attributes.
+                if let Some(repr) = clean::repr_attributes(
+                    self.cx.tcx(),
+                    self.cx.cache(),
+                    self.def_id,
+                    ItemType::Union,
+                    false,
+                ) {
+                    writeln!(f, "{repr}")?;
+                };
+            } else {
+                for a in self.it.attributes_and_repr(self.cx.tcx(), self.cx.cache(), false) {
+                    writeln!(f, "{a}")?;
+                }
+            }
+            Ok(())
+        })
     }
+}
 
+fn item_union(cx: &Context<'_>, it: &clean::Item, s: &clean::Union) -> impl fmt::Display {
     fmt::from_fn(|w| {
-        ItemUnion { cx, it, s }.render_into(w).unwrap();
+        ItemUnion {
+            cx,
+            it,
+            fields: &s.fields,
+            generics: &s.generics,
+            is_type_alias: false,
+            def_id: it.def_id().unwrap(),
+        }
+        .render_into(w)?;
         Ok(())
     })
 }
@@ -1533,41 +1530,81 @@ fn print_tuple_struct_fields(cx: &Context<'_>, s: &[clean::Item]) -> impl Displa
     })
 }
 
-fn item_enum(cx: &Context<'_>, it: &clean::Item, e: &clean::Enum) -> impl fmt::Display {
-    fmt::from_fn(|w| {
-        let count_variants = e.variants().count();
+struct DisplayEnum<'clean> {
+    variants: &'clean IndexVec<VariantIdx, clean::Item>,
+    generics: &'clean clean::Generics,
+    is_non_exhaustive: bool,
+    def_id: DefId,
+}
+
+impl<'clean> DisplayEnum<'clean> {
+    fn render_into<W: fmt::Write>(
+        self,
+        cx: &Context<'_>,
+        it: &clean::Item,
+        is_type_alias: bool,
+        w: &mut W,
+    ) -> fmt::Result {
+        let non_stripped_variant_count = self.variants.iter().filter(|i| !i.is_stripped()).count();
+        let variants_len = self.variants.len();
+        let has_stripped_entries = variants_len != non_stripped_variant_count;
+
         wrap_item(w, |w| {
-            render_attributes_in_code(w, it, cx);
+            if is_type_alias {
+                // For now the only attributes we render for type aliases are `repr` attributes.
+                render_repr_attributes_in_code(w, cx, self.def_id, ItemType::Enum);
+            } else {
+                render_attributes_in_code(w, it, cx);
+            }
             write!(
                 w,
                 "{}enum {}{}{}",
                 visibility_print_with_space(it, cx),
                 it.name.unwrap(),
-                e.generics.print(cx),
+                self.generics.print(cx),
                 render_enum_fields(
                     cx,
-                    Some(&e.generics),
-                    &e.variants,
-                    count_variants,
-                    e.has_stripped_entries(),
-                    it.is_non_exhaustive(),
-                    it.def_id().unwrap(),
+                    Some(self.generics),
+                    self.variants,
+                    non_stripped_variant_count,
+                    has_stripped_entries,
+                    self.is_non_exhaustive,
+                    self.def_id,
                 ),
             )
         })?;
 
-        write!(w, "{}", document(cx, it, None, HeadingOffset::H2))?;
+        let def_id = it.item_id.expect_def_id();
+        let layout_def_id = if is_type_alias {
+            self.def_id
+        } else {
+            write!(w, "{}", document(cx, it, None, HeadingOffset::H2))?;
+            // We don't return the same `DefId` since the layout size of the type alias might be
+            // different since we might have more information on the generics.
+            def_id
+        };
 
-        if count_variants != 0 {
-            write!(w, "{}", item_variants(cx, it, &e.variants, it.def_id().unwrap()))?;
+        if non_stripped_variant_count != 0 {
+            write!(w, "{}", item_variants(cx, it, self.variants, self.def_id))?;
         }
-        let def_id = it.item_id.expect_def_id();
         write!(
             w,
             "{}{}",
             render_assoc_items(cx, it, def_id, AssocItemRender::All),
-            document_type_layout(cx, def_id)
+            document_type_layout(cx, layout_def_id)
         )
+    }
+}
+
+fn item_enum(cx: &Context<'_>, it: &clean::Item, e: &clean::Enum) -> impl fmt::Display {
+    fmt::from_fn(|w| {
+        DisplayEnum {
+            variants: &e.variants,
+            generics: &e.generics,
+            is_non_exhaustive: it.is_non_exhaustive(),
+            def_id: it.def_id().unwrap(),
+        }
+        .render_into(cx, it, false, w)
     })
 }
 
@@ -1955,27 +1992,59 @@ fn item_constant(
     })
 }
 
-fn item_struct(cx: &Context<'_>, it: &clean::Item, s: &clean::Struct) -> impl fmt::Display {
-    fmt::from_fn(|w| {
+struct DisplayStruct<'a> {
+    ctor_kind: Option<CtorKind>,
+    generics: &'a clean::Generics,
+    fields: &'a [clean::Item],
+    def_id: DefId,
+}
+
+impl<'a> DisplayStruct<'a> {
+    fn render_into<W: fmt::Write>(
+        self,
+        cx: &Context<'_>,
+        it: &clean::Item,
+        is_type_alias: bool,
+        w: &mut W,
+    ) -> fmt::Result {
         wrap_item(w, |w| {
-            render_attributes_in_code(w, it, cx);
+            if is_type_alias {
+                // For now the only attributes we render for type aliases are `repr` attributes.
+                render_repr_attributes_in_code(w, cx, self.def_id, ItemType::Struct);
+            } else {
+                render_attributes_in_code(w, it, cx);
+            }
             write!(
                 w,
                 "{}",
-                render_struct(it, Some(&s.generics), s.ctor_kind, &s.fields, "", true, cx)
+                render_struct(it, Some(self.generics), self.ctor_kind, self.fields, "", true, cx)
             )
         })?;
 
-        let def_id = it.item_id.expect_def_id();
+        if !is_type_alias {
+            write!(w, "{}", document(cx, it, None, HeadingOffset::H2))?;
+        }
 
+        let def_id = it.item_id.expect_def_id();
         write!(
             w,
-            "{}{}{}{}",
-            document(cx, it, None, HeadingOffset::H2),
-            item_fields(cx, it, &s.fields, s.ctor_kind),
+            "{}{}{}",
+            item_fields(cx, it, self.fields, self.ctor_kind),
             render_assoc_items(cx, it, def_id, AssocItemRender::All),
             document_type_layout(cx, def_id),
         )
+    }
+}
+
+fn item_struct(cx: &Context<'_>, it: &clean::Item, s: &clean::Struct) -> impl fmt::Display {
+    fmt::from_fn(|w| {
+        DisplayStruct {
+            ctor_kind: s.ctor_kind,
+            generics: &s.generics,
+            fields: s.fields.as_slice(),
+            def_id: it.def_id().unwrap(),
+        }
+        .render_into(cx, it, false, w)
     })
 }
 
diff --git a/src/librustdoc/html/render/sidebar.rs b/src/librustdoc/html/render/sidebar.rs
index 361966325fb3c..91540e06e3398 100644
--- a/src/librustdoc/html/render/sidebar.rs
+++ b/src/librustdoc/html/render/sidebar.rs
@@ -599,7 +599,7 @@ fn sidebar_enum<'a>(
     deref_id_map: &'a DefIdMap<String>,
 ) {
     let mut variants = e
-        .variants()
+        .non_stripped_variants()
         .filter_map(|v| v.name)
         .map(|name| Link::new(format!("variant.{name}"), name.to_string()))
         .collect::<Vec<_>>();
diff --git a/src/librustdoc/html/templates/item_union.html b/src/librustdoc/html/templates/item_union.html
index b1c1d5a63a03c..b5d3367a6a10b 100644
--- a/src/librustdoc/html/templates/item_union.html
+++ b/src/librustdoc/html/templates/item_union.html
@@ -2,15 +2,16 @@
     {{ self.render_attributes_in_pre()|safe }}
     {{ self.render_union()|safe }}
 </code></pre>
-{{ self.document()|safe }}
-{% if self.fields_iter().peek().is_some() %}
+{% if !self.is_type_alias %}
+    {{ self.document()|safe }}
+{% endif %}
+{% if self.fields_iter().next().is_some() %}
     <h2 id="fields" class="fields section-header"> {# #}
         Fields<a href="#fields" class="anchor">§</a> {# #}
     </h2>
     {% for (field, ty) in self.fields_iter() %}
         {% let name = field.name.expect("union field name") %}
-        <span id="structfield.{{ name }}" {#+ #}
-            class="{{ ItemType::StructField +}} section-header"> {# #}
+        <span id="structfield.{{ name }}" class="{{ ItemType::StructField +}} section-header"> {# #}
             <a href="#structfield.{{ name }}" class="anchor field">§</a> {# #}
             <code>{{ name }}: {{+ self.print_ty(ty)|safe }}</code> {# #}
         </span>
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 705f9b2202c60..bfcb794b89a27 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -40,7 +40,7 @@ impl JsonRenderer<'_> {
             })
             .collect();
         let docs = item.opt_doc_value();
-        let attrs = item.attributes(self.tcx, self.cache(), true);
+        let attrs = item.attributes_and_repr(self.tcx, self.cache(), true);
         let span = item.span(self.tcx);
         let visibility = item.visibility(self.tcx);
         let clean::ItemInner { name, item_id, .. } = *item.inner;
diff --git a/tests/rustdoc/type-alias/repr.rs b/tests/rustdoc/type-alias/repr.rs
new file mode 100644
index 0000000000000..cf90798036099
--- /dev/null
+++ b/tests/rustdoc/type-alias/repr.rs
@@ -0,0 +1,42 @@
+// This test ensures that the `repr` attribute is displayed in type aliases.
+//
+// Regression test for <https://github.com/rust-lang/rust/issues/140739>.
+
+#![crate_name = "foo"]
+
+/// bla
+#[repr(C)]
+pub struct Foo1;
+
+//@ has 'foo/type.Bar1.html'
+//@ has - '//*[@class="rust item-decl"]/code' '#[repr(C)]pub struct Bar1;'
+// Ensures that we see the doc comment of the type alias and not of the aliased type.
+//@ has - '//*[@class="toggle top-doc"]/*[@class="docblock"]' 'bar'
+/// bar
+pub type Bar1 = Foo1;
+
+/// bla
+#[repr(C)]
+pub union Foo2 {
+    pub a: u8,
+}
+
+//@ has 'foo/type.Bar2.html'
+//@ matches - '//*[@class="rust item-decl"]' '#\[repr\(C\)\]\npub union Bar2 \{*'
+// Ensures that we see the doc comment of the type alias and not of the aliased type.
+//@ has - '//*[@class="toggle top-doc"]/*[@class="docblock"]' 'bar'
+/// bar
+pub type Bar2 = Foo2;
+
+/// bla
+#[repr(C)]
+pub enum Foo3 {
+    A,
+}
+
+//@ has 'foo/type.Bar3.html'
+//@ matches - '//*[@class="rust item-decl"]' '#\[repr\(C\)\]pub enum Bar3 \{*'
+// Ensures that we see the doc comment of the type alias and not of the aliased type.
+//@ has - '//*[@class="toggle top-doc"]/*[@class="docblock"]' 'bar'
+/// bar
+pub type Bar3 = Foo3;
diff --git a/tests/rustdoc/type-layout.rs b/tests/rustdoc/type-layout.rs
index 6de435dbcc143..482b8b597dd30 100644
--- a/tests/rustdoc/type-layout.rs
+++ b/tests/rustdoc/type-layout.rs
@@ -61,7 +61,7 @@ pub type TypeAlias = X;
 pub type GenericTypeAlias = (Generic<(u32, ())>, Generic<u32>);
 
 // Regression test for the rustdoc equivalent of #85103.
-//@ hasraw type_layout/type.Edges.html 'Encountered an error during type layout; the type failed to be normalized.'
+//@ hasraw type_layout/type.Edges.html 'Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.'
 pub type Edges<'a, E> = std::borrow::Cow<'a, [E]>;
 
 //@ !hasraw type_layout/trait.MyTrait.html 'Size: '
diff --git a/tests/ui/consts/const-eval/dont_promote_unstable_const_fn.stderr b/tests/ui/consts/const-eval/dont_promote_unstable_const_fn.stderr
index a506f2a282bbb..b505b76a6abfa 100644
--- a/tests/ui/consts/const-eval/dont_promote_unstable_const_fn.stderr
+++ b/tests/ui/consts/const-eval/dont_promote_unstable_const_fn.stderr
@@ -5,14 +5,9 @@ LL | const fn bar() -> u32 { foo() }
    |                         ^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar() -> u32 { foo() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo)]
 LL | const fn bar() -> u32 { foo() }
    |
 
diff --git a/tests/ui/consts/const-unstable-intrinsic.stderr b/tests/ui/consts/const-unstable-intrinsic.stderr
index 308b02386f5c9..7e7ba966cee17 100644
--- a/tests/ui/consts/const-unstable-intrinsic.stderr
+++ b/tests/ui/consts/const-unstable-intrinsic.stderr
@@ -46,14 +46,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |         size_of_val(&x);
    |         ^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_main() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(local)]
 LL | const fn const_main() {
    |
 
@@ -63,14 +58,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |         min_align_of_val(&x);
    |         ^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_main() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(local)]
 LL | const fn const_main() {
    |
 
@@ -88,14 +78,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |         super::size_of_val(src);
    |         ^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL +     #[rustc_const_unstable(feature = "...", issue = "...")]
-LL |     const unsafe fn copy<T>(src: *const T, _dst: *mut T, _count: usize) {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL +     #[rustc_allow_const_fn_unstable(local)]
 LL |     const unsafe fn copy<T>(src: *const T, _dst: *mut T, _count: usize) {
    |
 
diff --git a/tests/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr b/tests/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
index 26dedc49a3928..9efc252ce6b09 100644
--- a/tests/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
+++ b/tests/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
@@ -5,14 +5,9 @@ LL | const fn bar() -> u32 { foo() }
    |                         ^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar() -> u32 { foo() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo)]
 LL | const fn bar() -> u32 { foo() }
    |
 
@@ -23,14 +18,9 @@ LL | const fn bar2() -> u32 { foo2() }
    |                          ^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar2() -> u32 { foo2() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const fn bar2() -> u32 { foo2() }
    |
 
@@ -40,14 +30,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     let x = async { 13 };
    |             ^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar3() -> u32 {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_async_blocks)]
 LL | const fn bar3() -> u32 {
    |
 
@@ -58,14 +43,9 @@ LL |     foo()
    |     ^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar3() -> u32 {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo)]
 LL | const fn bar3() -> u32 {
    |
 
@@ -76,14 +56,9 @@ LL | const fn bar2_gated() -> u32 { foo2_gated() }
    |                                ^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn bar2_gated() -> u32 { foo2_gated() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const fn bar2_gated() -> u32 { foo2_gated() }
    |
 
@@ -94,14 +69,9 @@ LL |     pub(crate) const fn bar2_gated_stable_indirect() -> u32 { super::foo2_g
    |                                                               ^^^^^^^^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL +     #[rustc_const_unstable(feature = "...", issue = "...")]
-LL |     pub(crate) const fn bar2_gated_stable_indirect() -> u32 { super::foo2_gated() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL +     #[rustc_allow_const_fn_unstable(foo2)]
 LL |     pub(crate) const fn bar2_gated_stable_indirect() -> u32 { super::foo2_gated() }
    |
 
@@ -112,14 +82,9 @@ LL | const fn stable_indirect() -> u32 { foo2_gated() }
    |                                     ^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_indirect() -> u32 { foo2_gated() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const fn stable_indirect() -> u32 { foo2_gated() }
    |
 
diff --git a/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr b/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
index b61f7db6f43b7..0712a790955a8 100644
--- a/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
+++ b/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
@@ -5,14 +5,9 @@ LL | const unsafe fn bar() -> u32 { unsafe { foo() } }
    |                                         ^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar() -> u32 { unsafe { foo() } }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo)]
 LL | const unsafe fn bar() -> u32 { unsafe { foo() } }
    |
 
@@ -23,14 +18,9 @@ LL | const unsafe fn bar2() -> u32 { unsafe { foo2() } }
    |                                          ^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar2() -> u32 { unsafe { foo2() } }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const unsafe fn bar2() -> u32 { unsafe { foo2() } }
    |
 
@@ -41,14 +31,9 @@ LL | const unsafe fn bar2_gated() -> u32 { unsafe { foo2_gated() } }
    |                                                ^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar2_gated() -> u32 { unsafe { foo2_gated() } }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const unsafe fn bar2_gated() -> u32 { unsafe { foo2_gated() } }
    |
 
diff --git a/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr b/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
index fad8e396e9ab5..618b9a16dd468 100644
--- a/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
+++ b/tests/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
@@ -5,14 +5,9 @@ LL | const unsafe fn bar() -> u32 { foo() }
    |                                ^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar() -> u32 { foo() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo)]
 LL | const unsafe fn bar() -> u32 { foo() }
    |
 
@@ -23,14 +18,9 @@ LL | const unsafe fn bar2() -> u32 { foo2() }
    |                                 ^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar2() -> u32 { foo2() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const unsafe fn bar2() -> u32 { foo2() }
    |
 
@@ -41,14 +31,9 @@ LL | const unsafe fn bar2_gated() -> u32 { foo2_gated() }
    |                                       ^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const unsafe fn bar2_gated() -> u32 { foo2_gated() }
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(foo2)]
 LL | const unsafe fn bar2_gated() -> u32 { foo2_gated() }
    |
 
diff --git a/tests/ui/consts/min_const_fn/recursive_const_stab_unmarked_crate_imports.stderr b/tests/ui/consts/min_const_fn/recursive_const_stab_unmarked_crate_imports.stderr
index bbe749f595893..04804cb6d339b 100644
--- a/tests/ui/consts/min_const_fn/recursive_const_stab_unmarked_crate_imports.stderr
+++ b/tests/ui/consts/min_const_fn/recursive_const_stab_unmarked_crate_imports.stderr
@@ -5,14 +5,9 @@ LL |     unstable_if_unmarked_const_fn_crate::not_stably_const();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_fn() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(rustc_private)]
 LL | const fn stable_fn() {
    |
 
diff --git a/tests/ui/consts/min_const_fn/recursive_const_stab_unstable_if_unmarked.stderr b/tests/ui/consts/min_const_fn/recursive_const_stab_unstable_if_unmarked.stderr
index 9d7b81c822bd1..14940ae93f894 100644
--- a/tests/ui/consts/min_const_fn/recursive_const_stab_unstable_if_unmarked.stderr
+++ b/tests/ui/consts/min_const_fn/recursive_const_stab_unstable_if_unmarked.stderr
@@ -5,14 +5,9 @@ LL |     not_stably_const();
    |     ^^^^^^^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | pub const fn expose_on_stable() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(rustc_private)]
 LL | pub const fn expose_on_stable() {
    |
 
@@ -22,14 +17,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     let _x = async { 15 };
    |              ^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | pub const fn expose_on_stable() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_async_blocks)]
 LL | pub const fn expose_on_stable() {
    |
 
diff --git a/tests/ui/intrinsics/const-eval-select-stability.stderr b/tests/ui/intrinsics/const-eval-select-stability.stderr
index 5f443b1d4ff7b..513c19cbb5b71 100644
--- a/tests/ui/intrinsics/const-eval-select-stability.stderr
+++ b/tests/ui/intrinsics/const-eval-select-stability.stderr
@@ -4,14 +4,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     const_eval_select((), nothing, log);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | pub const fn hey() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_eval_select)]
 LL | pub const fn hey() {
    |
 
diff --git a/tests/ui/traits/const-traits/staged-api.stderr b/tests/ui/traits/const-traits/staged-api.stderr
index cdf577287eec5..4756c490cb10a 100644
--- a/tests/ui/traits/const-traits/staged-api.stderr
+++ b/tests/ui/traits/const-traits/staged-api.stderr
@@ -71,14 +71,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn const_context() {
    |
 
@@ -88,14 +83,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn const_context() {
    |
 
@@ -105,14 +95,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn const_context() {
    |
 
@@ -122,14 +107,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn const_context() {
    |
 
@@ -139,14 +119,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable2::func();
    |     ^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn const_context() {
    |
 
@@ -156,14 +131,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable2::func();
    |     ^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn const_context() {
    |
 
@@ -173,14 +143,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     conditionally_const::<Foo>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn const_context() {
    |
 
@@ -190,14 +155,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn stable_const_context() {
    |
 
@@ -207,14 +167,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn stable_const_context() {
    |
 
@@ -224,14 +179,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn stable_const_context() {
    |
 
@@ -241,14 +191,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn stable_const_context() {
    |
 
@@ -259,14 +204,9 @@ LL |     const_context_not_const_stable();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(local_feature)]
 LL | const fn stable_const_context() {
    |
 
@@ -276,14 +216,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     conditionally_const::<Foo>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn stable_const_context() {
    |
 
@@ -293,14 +228,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn implicitly_stable_const_context() {
    |
 
@@ -310,14 +240,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Unstable::func();
    |     ^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn implicitly_stable_const_context() {
    |
 
@@ -327,14 +252,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn implicitly_stable_const_context() {
    |
 
@@ -344,14 +264,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     Foo::func();
    |     ^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(unstable)]
 LL | const fn implicitly_stable_const_context() {
    |
 
@@ -362,14 +277,9 @@ LL |     const_context_not_const_stable();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: mark the callee as `#[rustc_const_stable_indirect]` if it does not itself require any unstable features
-help: if the caller is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the caller is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(local_feature)]
 LL | const fn implicitly_stable_const_context() {
    |
 
@@ -379,14 +289,9 @@ error: const function that might be (indirectly) exposed to stable cannot use `#
 LL |     conditionally_const::<Foo>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this is what you probably want to do)
+help: if the function is not (yet) meant to be exposed to stable const contexts, add `#[rustc_const_unstable]`
    |
 LL + #[rustc_const_unstable(feature = "...", issue = "...")]
-LL | const fn implicitly_stable_const_context() {
-   |
-help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
-   |
-LL + #[rustc_allow_const_fn_unstable(const_trait_impl)]
 LL | const fn implicitly_stable_const_context() {
    |