diff --git a/compiler/rustc_attr_parsing/src/attributes/deprecation.rs b/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
index 8101c91460f26..d3a61f3a6535d 100644
--- a/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/deprecation.rs
@@ -54,6 +54,8 @@ impl<S: Stage> SingleAttributeParser<S> for DeprecationParser {
         Allow(Target::TyAlias),
         Allow(Target::Use),
         Allow(Target::ForeignFn),
+        Allow(Target::ForeignStatic),
+        Allow(Target::ForeignTy),
         Allow(Target::Field),
         Allow(Target::Trait),
         Allow(Target::AssocTy),
diff --git a/compiler/rustc_attr_parsing/src/attributes/inline.rs b/compiler/rustc_attr_parsing/src/attributes/inline.rs
index 6a659a95b856f..33c21bad2401b 100644
--- a/compiler/rustc_attr_parsing/src/attributes/inline.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/inline.rs
@@ -62,8 +62,8 @@ impl<S: Stage> SingleAttributeParser<S> for InlineParser {
                 }
             }
             ArgParser::NameValue(_) => {
-                let suggestions =
-                    <Self as SingleAttributeParser<S>>::TEMPLATE.suggestions(false, "inline");
+                let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
+                    .suggestions(cx.attr_style, "inline");
                 let span = cx.attr_span;
                 cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
                 return None;
diff --git a/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
index c9b5dd35fa1d9..8928129c2013d 100644
--- a/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
@@ -107,7 +107,7 @@ impl<S: Stage> AttributeParser<S> for MacroUseParser {
                     }
                 }
                 ArgParser::NameValue(_) => {
-                    let suggestions = MACRO_USE_TEMPLATE.suggestions(false, sym::macro_use);
+                    let suggestions = MACRO_USE_TEMPLATE.suggestions(cx.attr_style, sym::macro_use);
                     cx.emit_err(session_diagnostics::IllFormedAttributeInputLint {
                         num_suggestions: suggestions.len(),
                         suggestions: DiagArgValue::StrListSepByAnd(
diff --git a/compiler/rustc_attr_parsing/src/attributes/mod.rs b/compiler/rustc_attr_parsing/src/attributes/mod.rs
index ed5d1d92b8caf..3d6e26a24b8e4 100644
--- a/compiler/rustc_attr_parsing/src/attributes/mod.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/mod.rs
@@ -43,6 +43,7 @@ pub(crate) mod no_implicit_prelude;
 pub(crate) mod non_exhaustive;
 pub(crate) mod path;
 pub(crate) mod proc_macro_attrs;
+pub(crate) mod prototype;
 pub(crate) mod repr;
 pub(crate) mod rustc_internal;
 pub(crate) mod semantics;
diff --git a/compiler/rustc_attr_parsing/src/attributes/must_use.rs b/compiler/rustc_attr_parsing/src/attributes/must_use.rs
index b6cfc78059066..b0ee3d1ba6e5c 100644
--- a/compiler/rustc_attr_parsing/src/attributes/must_use.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/must_use.rs
@@ -35,8 +35,8 @@ impl<S: Stage> SingleAttributeParser<S> for MustUseParser {
                     Some(value_str)
                 }
                 ArgParser::List(_) => {
-                    let suggestions =
-                        <Self as SingleAttributeParser<S>>::TEMPLATE.suggestions(false, "must_use");
+                    let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
+                        .suggestions(cx.attr_style, "must_use");
                     cx.emit_err(session_diagnostics::IllFormedAttributeInputLint {
                         num_suggestions: suggestions.len(),
                         suggestions: DiagArgValue::StrListSepByAnd(
diff --git a/compiler/rustc_attr_parsing/src/attributes/prototype.rs b/compiler/rustc_attr_parsing/src/attributes/prototype.rs
new file mode 100644
index 0000000000000..fb1e47298b4cc
--- /dev/null
+++ b/compiler/rustc_attr_parsing/src/attributes/prototype.rs
@@ -0,0 +1,140 @@
+//! Attributes that are only used on function prototypes.
+
+use rustc_feature::{AttributeTemplate, template};
+use rustc_hir::Target;
+use rustc_hir::attrs::{AttributeKind, MirDialect, MirPhase};
+use rustc_span::{Span, Symbol, sym};
+
+use super::{AttributeOrder, OnDuplicate};
+use crate::attributes::SingleAttributeParser;
+use crate::context::{AcceptContext, AllowedTargets, MaybeWarn, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct CustomMirParser;
+
+impl<S: Stage> SingleAttributeParser<S> for CustomMirParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::custom_mir];
+
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+
+    const ALLOWED_TARGETS: AllowedTargets =
+        AllowedTargets::AllowList(&[MaybeWarn::Allow(Target::Fn)]);
+
+    const TEMPLATE: AttributeTemplate = template!(List: &[r#"dialect = "...", phase = "...""#]);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let Some(list) = args.list() else {
+            cx.expected_list(cx.attr_span);
+            return None;
+        };
+
+        let mut dialect = None;
+        let mut phase = None;
+        let mut failed = false;
+
+        for item in list.mixed() {
+            let Some(meta_item) = item.meta_item() else {
+                cx.expected_name_value(item.span(), None);
+                failed = true;
+                break;
+            };
+
+            if let Some(arg) = meta_item.word_is(sym::dialect) {
+                extract_value(cx, sym::dialect, arg, meta_item.span(), &mut dialect, &mut failed);
+            } else if let Some(arg) = meta_item.word_is(sym::phase) {
+                extract_value(cx, sym::phase, arg, meta_item.span(), &mut phase, &mut failed);
+            } else if let Some(word) = meta_item.path().word() {
+                let word = word.to_string();
+                cx.unknown_key(meta_item.span(), word, &["dialect", "phase"]);
+                failed = true;
+            } else {
+                cx.expected_name_value(meta_item.span(), None);
+                failed = true;
+            };
+        }
+
+        let dialect = parse_dialect(cx, dialect, &mut failed);
+        let phase = parse_phase(cx, phase, &mut failed);
+
+        if failed {
+            return None;
+        }
+
+        Some(AttributeKind::CustomMir(dialect, phase, cx.attr_span))
+    }
+}
+
+fn extract_value<S: Stage>(
+    cx: &mut AcceptContext<'_, '_, S>,
+    key: Symbol,
+    arg: &ArgParser<'_>,
+    span: Span,
+    out_val: &mut Option<(Symbol, Span)>,
+    failed: &mut bool,
+) {
+    if out_val.is_some() {
+        cx.duplicate_key(span, key);
+        *failed = true;
+        return;
+    }
+
+    let Some(val) = arg.name_value() else {
+        cx.expected_single_argument(arg.span().unwrap_or(span));
+        *failed = true;
+        return;
+    };
+
+    let Some(value_sym) = val.value_as_str() else {
+        cx.expected_string_literal(val.value_span, Some(val.value_as_lit()));
+        *failed = true;
+        return;
+    };
+
+    *out_val = Some((value_sym, val.value_span));
+}
+
+fn parse_dialect<S: Stage>(
+    cx: &mut AcceptContext<'_, '_, S>,
+    dialect: Option<(Symbol, Span)>,
+    failed: &mut bool,
+) -> Option<(MirDialect, Span)> {
+    let (dialect, span) = dialect?;
+
+    let dialect = match dialect {
+        sym::analysis => MirDialect::Analysis,
+        sym::built => MirDialect::Built,
+        sym::runtime => MirDialect::Runtime,
+
+        _ => {
+            cx.expected_specific_argument(span, vec!["analysis", "built", "runtime"]);
+            *failed = true;
+            return None;
+        }
+    };
+
+    Some((dialect, span))
+}
+
+fn parse_phase<S: Stage>(
+    cx: &mut AcceptContext<'_, '_, S>,
+    phase: Option<(Symbol, Span)>,
+    failed: &mut bool,
+) -> Option<(MirPhase, Span)> {
+    let (phase, span) = phase?;
+
+    let phase = match phase {
+        sym::initial => MirPhase::Initial,
+        sym::post_cleanup => MirPhase::PostCleanup,
+        sym::optimized => MirPhase::Optimized,
+
+        _ => {
+            cx.expected_specific_argument(span, vec!["initial", "post-cleanup", "optimized"]);
+            *failed = true;
+            return None;
+        }
+    };
+
+    Some((phase, span))
+}
diff --git a/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
index 8b666c3868baf..164c680b8a8de 100644
--- a/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
@@ -29,7 +29,7 @@ impl<S: Stage> SingleAttributeParser<S> for IgnoreParser {
                 ArgParser::NameValue(name_value) => {
                     let Some(str_value) = name_value.value_as_str() else {
                         let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
-                            .suggestions(false, "ignore");
+                            .suggestions(cx.attr_style, "ignore");
                         let span = cx.attr_span;
                         cx.emit_lint(
                             AttributeLintKind::IllFormedAttributeInput { suggestions },
@@ -40,8 +40,8 @@ impl<S: Stage> SingleAttributeParser<S> for IgnoreParser {
                     Some(str_value)
                 }
                 ArgParser::List(_) => {
-                    let suggestions =
-                        <Self as SingleAttributeParser<S>>::TEMPLATE.suggestions(false, "ignore");
+                    let suggestions = <Self as SingleAttributeParser<S>>::TEMPLATE
+                        .suggestions(cx.attr_style, "ignore");
                     let span = cx.attr_span;
                     cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
                     return None;
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index bebe3350c4e0d..c0d3bc99ba956 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -5,7 +5,7 @@ use std::sync::LazyLock;
 
 use itertools::Itertools;
 use private::Sealed;
-use rustc_ast::{self as ast, LitKind, MetaItemLit, NodeId};
+use rustc_ast::{self as ast, AttrStyle, LitKind, MetaItemLit, NodeId};
 use rustc_errors::{DiagCtxtHandle, Diagnostic};
 use rustc_feature::{AttributeTemplate, Features};
 use rustc_hir::attrs::AttributeKind;
@@ -46,6 +46,7 @@ use crate::attributes::path::PathParser as PathAttributeParser;
 use crate::attributes::proc_macro_attrs::{
     ProcMacroAttributeParser, ProcMacroDeriveParser, ProcMacroParser, RustcBuiltinMacroParser,
 };
+use crate::attributes::prototype::CustomMirParser;
 use crate::attributes::repr::{AlignParser, ReprParser};
 use crate::attributes::rustc_internal::{
     RustcLayoutScalarValidRangeEnd, RustcLayoutScalarValidRangeStart,
@@ -167,6 +168,7 @@ attribute_parsers!(
 
         // tidy-alphabetical-start
         Single<CoverageParser>,
+        Single<CustomMirParser>,
         Single<DeprecationParser>,
         Single<DummyParser>,
         Single<ExportNameParser>,
@@ -313,6 +315,7 @@ pub struct AcceptContext<'f, 'sess, S: Stage> {
     /// The span of the attribute currently being parsed
     pub(crate) attr_span: Span,
 
+    pub(crate) attr_style: AttrStyle,
     /// The expected structure of the attribute.
     ///
     /// Used in reporting errors to give a hint to users what the attribute *should* look like.
@@ -394,6 +397,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
                     i.kind.is_bytestr().then(|| self.sess().source_map().start_point(i.span))
                 }),
             },
+            attr_style: self.attr_style,
         })
     }
 
@@ -404,6 +408,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedIntegerLiteral,
+            attr_style: self.attr_style,
         })
     }
 
@@ -414,6 +419,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedList,
+            attr_style: self.attr_style,
         })
     }
 
@@ -424,6 +430,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedNoArgs,
+            attr_style: self.attr_style,
         })
     }
 
@@ -435,6 +442,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedIdentifier,
+            attr_style: self.attr_style,
         })
     }
 
@@ -447,6 +455,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedNameValue(name),
+            attr_style: self.attr_style,
         })
     }
 
@@ -458,6 +467,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::DuplicateKey(key),
+            attr_style: self.attr_style,
         })
     }
 
@@ -470,6 +480,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::UnexpectedLiteral,
+            attr_style: self.attr_style,
         })
     }
 
@@ -480,6 +491,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedSingleArgument,
+            attr_style: self.attr_style,
         })
     }
 
@@ -490,6 +502,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
             template: self.template.clone(),
             attribute: self.attr_path.clone(),
             reason: AttributeParseErrorReason::ExpectedAtLeastOneArgument,
+            attr_style: self.attr_style,
         })
     }
 
@@ -508,6 +521,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
                 strings: false,
                 list: false,
             },
+            attr_style: self.attr_style,
         })
     }
 
@@ -526,6 +540,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
                 strings: false,
                 list: true,
             },
+            attr_style: self.attr_style,
         })
     }
 
@@ -544,6 +559,7 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
                 strings: true,
                 list: false,
             },
+            attr_style: self.attr_style,
         })
     }
 
@@ -802,6 +818,7 @@ impl<'sess> AttributeParser<'sess, Early> {
                 },
             },
             attr_span: attr.span,
+            attr_style: attr.style,
             template,
             attr_path: path.get_attribute_path(),
         };
@@ -912,6 +929,7 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
                                     emit_lint: &mut emit_lint,
                                 },
                                 attr_span: lower_span(attr.span),
+                                attr_style: attr.style,
                                 template: &accept.template,
                                 attr_path: path.get_attribute_path(),
                             };
@@ -1060,6 +1078,9 @@ pub(crate) fn allowed_targets_applied(
         if !features.stmt_expr_attributes() {
             allowed_targets.retain(|t| !matches!(t, Target::Expression | Target::Statement));
         }
+        if !features.extern_types() {
+            allowed_targets.retain(|t| !matches!(t, Target::ForeignTy));
+        }
     }
 
     // We define groups of "similar" targets.
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
index 95e85667cd662..c65937b35b3ec 100644
--- a/compiler/rustc_attr_parsing/src/session_diagnostics.rs
+++ b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -1,6 +1,6 @@
 use std::num::IntErrorKind;
 
-use rustc_ast as ast;
+use rustc_ast::{self as ast, AttrStyle};
 use rustc_errors::codes::*;
 use rustc_errors::{
     Applicability, Diag, DiagArgValue, DiagCtxtHandle, Diagnostic, EmissionGuarantee, Level,
@@ -579,6 +579,7 @@ pub(crate) enum AttributeParseErrorReason {
 pub(crate) struct AttributeParseError {
     pub(crate) span: Span,
     pub(crate) attr_span: Span,
+    pub(crate) attr_style: AttrStyle,
     pub(crate) template: AttributeTemplate,
     pub(crate) attribute: AttrPath,
     pub(crate) reason: AttributeParseErrorReason,
@@ -717,7 +718,8 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
         if let Some(link) = self.template.docs {
             diag.note(format!("for more information, visit <{link}>"));
         }
-        let suggestions = self.template.suggestions(false, &name);
+        let suggestions = self.template.suggestions(self.attr_style, &name);
+
         diag.span_suggestions(
             self.attr_span,
             if suggestions.len() == 1 {
diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
index 86a4927f3903f..1bcea95fbb7b0 100644
--- a/compiler/rustc_builtin_macros/src/lib.rs
+++ b/compiler/rustc_builtin_macros/src/lib.rs
@@ -8,7 +8,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
-#![feature(autodiff)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index a6daacd95ef80..8f1218bb505fb 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -497,7 +497,7 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
             to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-module", module));
 
             let name =
-                codegen_fn_attrs.link_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));
+                codegen_fn_attrs.symbol_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));
             let name = name.as_str();
             to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-name", name));
         }
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index cb98df59c1b1c..427c75d40e9c6 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -1453,7 +1453,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         instance: Option<Instance<'tcx>>,
     ) {
         let call = self.call(llty, fn_attrs, Some(fn_abi), llfn, args, funclet, instance);
-        llvm::LLVMRustSetTailCallKind(call, llvm::TailCallKind::MustTail);
+        llvm::LLVMSetTailCallKind(call, llvm::TailCallKind::MustTail);
 
         match &fn_abi.ret.mode {
             PassMode::Ignore | PassMode::Indirect { .. } => self.ret_void(),
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index ad3c3d5932eef..8265b0114ce95 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -97,6 +97,7 @@ pub(crate) enum ModuleFlagMergeBehavior {
 
 // Consts for the LLVM CallConv type, pre-cast to usize.
 
+/// Must match the layout of `LLVMTailCallKind`.
 #[derive(Copy, Clone, PartialEq, Debug)]
 #[repr(C)]
 #[allow(dead_code)]
@@ -332,10 +333,15 @@ impl RealPredicate {
     }
 }
 
-/// LLVMTypeKind
-#[derive(Copy, Clone, PartialEq, Debug)]
+/// Must match the layout of `LLVMTypeKind`.
+///
+/// Use [`RawEnum<TypeKind>`] for values of `LLVMTypeKind` returned from LLVM,
+/// to avoid risk of UB if LLVM adds new enum values.
+///
+/// All of LLVM's variants should be declared here, even if no Rust-side code refers
+/// to them, because unknown variants will cause [`RawEnum::to_rust`] to panic.
+#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)]
 #[repr(C)]
-#[expect(dead_code, reason = "Some variants are unused, but are kept to match LLVM-C")]
 pub(crate) enum TypeKind {
     Void = 0,
     Half = 1,
@@ -1046,6 +1052,8 @@ unsafe extern "C" {
         CanThrow: llvm::Bool,
     ) -> &'ll Value;
 
+    pub(crate) safe fn LLVMGetTypeKind(Ty: &Type) -> RawEnum<TypeKind>;
+
     // Operations on integer types
     pub(crate) fn LLVMInt1TypeInContext(C: &Context) -> &Type;
     pub(crate) fn LLVMInt8TypeInContext(C: &Context) -> &Type;
@@ -1197,7 +1205,7 @@ unsafe extern "C" {
     pub(crate) safe fn LLVMIsGlobalConstant(GlobalVar: &Value) -> Bool;
     pub(crate) safe fn LLVMSetGlobalConstant(GlobalVar: &Value, IsConstant: Bool);
     pub(crate) safe fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool);
-    pub(crate) safe fn LLVMRustSetTailCallKind(CallInst: &Value, Kind: TailCallKind);
+    pub(crate) safe fn LLVMSetTailCallKind(CallInst: &Value, kind: TailCallKind);
 
     // Operations on attributes
     pub(crate) fn LLVMCreateStringAttribute(
@@ -1841,9 +1849,6 @@ unsafe extern "C" {
     // Create and destroy contexts.
     pub(crate) fn LLVMRustContextCreate(shouldDiscardNames: bool) -> &'static mut Context;
 
-    /// See llvm::LLVMTypeKind::getTypeID.
-    pub(crate) fn LLVMRustGetTypeKind(Ty: &Type) -> TypeKind;
-
     // Operations on all values
     pub(crate) fn LLVMRustGlobalAddMetadata<'a>(
         Val: &'a Value,
diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs
index 893655031388c..f02d16baf94e7 100644
--- a/compiler/rustc_codegen_llvm/src/type_.rs
+++ b/compiler/rustc_codegen_llvm/src/type_.rs
@@ -204,7 +204,7 @@ impl<'ll, CX: Borrow<SCx<'ll>>> BaseTypeCodegenMethods for GenericCx<'ll, CX> {
     }
 
     fn type_kind(&self, ty: &'ll Type) -> TypeKind {
-        unsafe { llvm::LLVMRustGetTypeKind(ty).to_generic() }
+        llvm::LLVMGetTypeKind(ty).to_rust().to_generic()
     }
 
     fn type_ptr(&self) -> &'ll Type {
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 67cd1f4cd41a0..8abaf201abae2 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -858,7 +858,7 @@ pub fn is_call_from_compiler_builtins_to_upstream_monomorphization<'tcx>(
     instance: Instance<'tcx>,
 ) -> bool {
     fn is_llvm_intrinsic(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-        if let Some(name) = tcx.codegen_fn_attrs(def_id).link_name {
+        if let Some(name) = tcx.codegen_fn_attrs(def_id).symbol_name {
             name.as_str().starts_with("llvm.")
         } else {
             false
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index af70f0deb0706..20385ba8e4cb5 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -6,7 +6,6 @@ use rustc_ast::{LitKind, MetaItem, MetaItemInner, attr};
 use rustc_hir::attrs::{AttributeKind, InlineAttr, InstructionSetAttr, UsedBy};
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE, LocalDefId};
-use rustc_hir::weak_lang_items::WEAK_LANG_ITEMS;
 use rustc_hir::{self as hir, Attribute, LangItem, find_attr, lang_items};
 use rustc_middle::middle::codegen_fn_attrs::{
     CodegenFnAttrFlags, CodegenFnAttrs, PatchableFunctionEntry,
@@ -182,7 +181,7 @@ fn process_builtin_attrs(
             match p {
                 AttributeKind::Cold(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD,
                 AttributeKind::ExportName { name, .. } => {
-                    codegen_fn_attrs.export_name = Some(*name)
+                    codegen_fn_attrs.symbol_name = Some(*name)
                 }
                 AttributeKind::Inline(inline, span) => {
                     codegen_fn_attrs.inline = *inline;
@@ -190,7 +189,13 @@ fn process_builtin_attrs(
                 }
                 AttributeKind::Naked(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED,
                 AttributeKind::Align { align, .. } => codegen_fn_attrs.alignment = Some(*align),
-                AttributeKind::LinkName { name, .. } => codegen_fn_attrs.link_name = Some(*name),
+                AttributeKind::LinkName { name, .. } => {
+                    // FIXME Remove check for foreign functions once #[link_name] on non-foreign
+                    // functions is a hard error
+                    if tcx.is_foreign_item(did) {
+                        codegen_fn_attrs.symbol_name = Some(*name);
+                    }
+                }
                 AttributeKind::LinkOrdinal { ordinal, span } => {
                     codegen_fn_attrs.link_ordinal = Some(*ordinal);
                     interesting_spans.link_ordinal = Some(*span);
@@ -410,7 +415,7 @@ fn apply_overrides(tcx: TyCtxt<'_>, did: LocalDefId, codegen_fn_attrs: &mut Code
             // * `#[rustc_std_internal_symbol]` mangles the symbol name in a special way
             //   both for exports and imports through foreign items. This is handled further,
             //   during symbol mangling logic.
-        } else if codegen_fn_attrs.link_name.is_some() {
+        } else if codegen_fn_attrs.symbol_name.is_some() {
             // * This can be overridden with the `#[link_name]` attribute
         } else {
             // NOTE: there's one more exception that we cannot apply here. On wasm,
@@ -465,7 +470,7 @@ fn check_result(
     }
 
     // error when specifying link_name together with link_ordinal
-    if let Some(_) = codegen_fn_attrs.link_name
+    if let Some(_) = codegen_fn_attrs.symbol_name
         && let Some(_) = codegen_fn_attrs.link_ordinal
     {
         let msg = "cannot use `#[link_name]` with `#[link_ordinal]`";
@@ -512,14 +517,11 @@ fn handle_lang_items(
     // strippable by the linker.
     //
     // Additionally weak lang items have predetermined symbol names.
-    if let Some(lang_item) = lang_item {
-        if WEAK_LANG_ITEMS.contains(&lang_item) {
-            codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
-        }
-        if let Some(link_name) = lang_item.link_name() {
-            codegen_fn_attrs.export_name = Some(link_name);
-            codegen_fn_attrs.link_name = Some(link_name);
-        }
+    if let Some(lang_item) = lang_item
+        && let Some(link_name) = lang_item.link_name()
+    {
+        codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
+        codegen_fn_attrs.symbol_name = Some(link_name);
     }
 
     // error when using no_mangle on a lang item item
diff --git a/compiler/rustc_errors/src/diagnostic_impls.rs b/compiler/rustc_errors/src/diagnostic_impls.rs
index eca5806fac520..698b6b8d50404 100644
--- a/compiler/rustc_errors/src/diagnostic_impls.rs
+++ b/compiler/rustc_errors/src/diagnostic_impls.rs
@@ -9,6 +9,7 @@ use rustc_abi::TargetDataLayoutErrors;
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_ast_pretty::pprust;
 use rustc_hir::RustcVersion;
+use rustc_hir::attrs::{MirDialect, MirPhase};
 use rustc_macros::Subdiagnostic;
 use rustc_span::edition::Edition;
 use rustc_span::{Ident, MacroRulesNormalizedIdent, Span, Symbol};
@@ -312,6 +313,28 @@ impl IntoDiagArg for ExprPrecedence {
     }
 }
 
+impl IntoDiagArg for MirDialect {
+    fn into_diag_arg(self, _path: &mut Option<PathBuf>) -> DiagArgValue {
+        let arg = match self {
+            MirDialect::Analysis => "analysis",
+            MirDialect::Built => "built",
+            MirDialect::Runtime => "runtime",
+        };
+        DiagArgValue::Str(Cow::Borrowed(arg))
+    }
+}
+
+impl IntoDiagArg for MirPhase {
+    fn into_diag_arg(self, _path: &mut Option<PathBuf>) -> DiagArgValue {
+        let arg = match self {
+            MirPhase::Initial => "initial",
+            MirPhase::PostCleanup => "post-cleanup",
+            MirPhase::Optimized => "optimized",
+        };
+        DiagArgValue::Str(Cow::Borrowed(arg))
+    }
+}
+
 #[derive(Clone)]
 pub struct DiagSymbolList<S = Symbol>(Vec<S>);
 
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 6fbedaf5b1033..7c889641fe0ab 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -6,6 +6,7 @@ use AttributeDuplicates::*;
 use AttributeGate::*;
 use AttributeType::*;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::AttrStyle;
 use rustc_hir::attrs::EncodeCrossCrate;
 use rustc_span::edition::Edition;
 use rustc_span::{Symbol, sym};
@@ -132,9 +133,12 @@ pub struct AttributeTemplate {
 }
 
 impl AttributeTemplate {
-    pub fn suggestions(&self, inner: bool, name: impl std::fmt::Display) -> Vec<String> {
+    pub fn suggestions(&self, style: AttrStyle, name: impl std::fmt::Display) -> Vec<String> {
         let mut suggestions = vec![];
-        let inner = if inner { "!" } else { "" };
+        let inner = match style {
+            AttrStyle::Outer => "",
+            AttrStyle::Inner => "!",
+        };
         if self.word {
             suggestions.push(format!("#{inner}[{name}]"));
         }
diff --git a/compiler/rustc_hir/src/attrs/data_structures.rs b/compiler/rustc_hir/src/attrs/data_structures.rs
index 510fc83297829..31715955ed341 100644
--- a/compiler/rustc_hir/src/attrs/data_structures.rs
+++ b/compiler/rustc_hir/src/attrs/data_structures.rs
@@ -205,6 +205,22 @@ pub enum Linkage {
     WeakODR,
 }
 
+#[derive(Clone, Copy, Decodable, Debug, Encodable, PartialEq)]
+#[derive(HashStable_Generic, PrintAttribute)]
+pub enum MirDialect {
+    Analysis,
+    Built,
+    Runtime,
+}
+
+#[derive(Clone, Copy, Decodable, Debug, Encodable, PartialEq)]
+#[derive(HashStable_Generic, PrintAttribute)]
+pub enum MirPhase {
+    Initial,
+    PostCleanup,
+    Optimized,
+}
+
 /// Represents parsed *built-in* inert attributes.
 ///
 /// ## Overview
@@ -324,6 +340,9 @@ pub enum AttributeKind {
     /// Represents `#[coverage(..)]`.
     Coverage(Span, CoverageAttrKind),
 
+    /// Represents `#[custom_mir]`.
+    CustomMir(Option<(MirDialect, Span)>, Option<(MirPhase, Span)>, Span),
+
     ///Represents `#[rustc_deny_explicit_impl]`.
     DenyExplicitImpl(Span),
 
diff --git a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
index 84a975523f2c8..defabdccc023a 100644
--- a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
+++ b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
@@ -31,6 +31,7 @@ impl AttributeKind {
             ConstTrait(..) => No,
             Coroutine(..) => No,
             Coverage(..) => No,
+            CustomMir(_, _, _) => Yes,
             DenyExplicitImpl(..) => No,
             Deprecation { .. } => Yes,
             DoNotImplementViaObject(..) => No,
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 0498a9383663a..940f0e3708d0a 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -290,6 +290,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             | ExprKind::Let(..)
             | ExprKind::Loop(..)
             | ExprKind::Match(..) => {}
+            // Do not warn on `as` casts from never to any,
+            // they are sometimes required to appeal typeck.
+            ExprKind::Cast(_, _) => {}
             // If `expr` is a result of desugaring the try block and is an ok-wrapped
             // diverging expression (e.g. it arose from desugaring of `try { return }`),
             // we skip issuing a warning because it is autogenerated code.
diff --git a/compiler/rustc_lint/src/foreign_modules.rs b/compiler/rustc_lint/src/foreign_modules.rs
index 759e6c927b828..3267e70f1de26 100644
--- a/compiler/rustc_lint/src/foreign_modules.rs
+++ b/compiler/rustc_lint/src/foreign_modules.rs
@@ -179,7 +179,7 @@ impl ClashingExternDeclarations {
 /// symbol's name.
 fn name_of_extern_decl(tcx: TyCtxt<'_>, fi: hir::OwnerId) -> SymbolName {
     if let Some((overridden_link_name, overridden_link_name_span)) =
-        tcx.codegen_fn_attrs(fi).link_name.map(|overridden_link_name| {
+        tcx.codegen_fn_attrs(fi).symbol_name.map(|overridden_link_name| {
             // FIXME: Instead of searching through the attributes again to get span
             // information, we could have codegen_fn_attrs also give span information back for
             // where the attribute was defined. However, until this is found to be a
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index cd4f80f808c65..e4fe1fc2e429f 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -1460,60 +1460,6 @@ LLVMRustGetDiagInfoKind(LLVMDiagnosticInfoRef DI) {
   return toRust((DiagnosticKind)unwrap(DI)->getKind());
 }
 
-// This is kept distinct from LLVMGetTypeKind, because when
-// a new type kind is added, the Rust-side enum must be
-// updated or UB will result.
-extern "C" LLVMTypeKind LLVMRustGetTypeKind(LLVMTypeRef Ty) {
-  switch (unwrap(Ty)->getTypeID()) {
-  case Type::VoidTyID:
-    return LLVMVoidTypeKind;
-  case Type::HalfTyID:
-    return LLVMHalfTypeKind;
-  case Type::FloatTyID:
-    return LLVMFloatTypeKind;
-  case Type::DoubleTyID:
-    return LLVMDoubleTypeKind;
-  case Type::X86_FP80TyID:
-    return LLVMX86_FP80TypeKind;
-  case Type::FP128TyID:
-    return LLVMFP128TypeKind;
-  case Type::PPC_FP128TyID:
-    return LLVMPPC_FP128TypeKind;
-  case Type::LabelTyID:
-    return LLVMLabelTypeKind;
-  case Type::MetadataTyID:
-    return LLVMMetadataTypeKind;
-  case Type::IntegerTyID:
-    return LLVMIntegerTypeKind;
-  case Type::FunctionTyID:
-    return LLVMFunctionTypeKind;
-  case Type::StructTyID:
-    return LLVMStructTypeKind;
-  case Type::ArrayTyID:
-    return LLVMArrayTypeKind;
-  case Type::PointerTyID:
-    return LLVMPointerTypeKind;
-  case Type::FixedVectorTyID:
-    return LLVMVectorTypeKind;
-  case Type::TokenTyID:
-    return LLVMTokenTypeKind;
-  case Type::ScalableVectorTyID:
-    return LLVMScalableVectorTypeKind;
-  case Type::BFloatTyID:
-    return LLVMBFloatTypeKind;
-  case Type::X86_AMXTyID:
-    return LLVMX86_AMXTypeKind;
-  default: {
-    std::string error;
-    auto stream = llvm::raw_string_ostream(error);
-    stream << "Rust does not support the TypeID: " << unwrap(Ty)->getTypeID()
-           << " for the type: " << *unwrap(Ty);
-    stream.flush();
-    report_fatal_error(error.c_str());
-  }
-  }
-}
-
 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(SMDiagnostic, LLVMSMDiagnosticRef)
 
 extern "C" LLVMSMDiagnosticRef LLVMRustGetSMDiagnostic(LLVMDiagnosticInfoRef DI,
@@ -1993,29 +1939,3 @@ extern "C" void LLVMRustSetNoSanitizeHWAddress(LLVMValueRef Global) {
   MD.NoHWAddress = true;
   GV.setSanitizerMetadata(MD);
 }
-
-enum class LLVMRustTailCallKind {
-  None = 0,
-  Tail = 1,
-  MustTail = 2,
-  NoTail = 3
-};
-
-extern "C" void LLVMRustSetTailCallKind(LLVMValueRef Call,
-                                        LLVMRustTailCallKind Kind) {
-  CallInst *CI = unwrap<CallInst>(Call);
-  switch (Kind) {
-  case LLVMRustTailCallKind::None:
-    CI->setTailCallKind(CallInst::TCK_None);
-    break;
-  case LLVMRustTailCallKind::Tail:
-    CI->setTailCallKind(CallInst::TCK_Tail);
-    break;
-  case LLVMRustTailCallKind::MustTail:
-    CI->setTailCallKind(CallInst::TCK_MustTail);
-    break;
-  case LLVMRustTailCallKind::NoTail:
-    CI->setTailCallKind(CallInst::TCK_NoTail);
-    break;
-  }
-}
diff --git a/compiler/rustc_macros/src/print_attribute.rs b/compiler/rustc_macros/src/print_attribute.rs
index 9023520c75043..0114e0dfde0db 100644
--- a/compiler/rustc_macros/src/print_attribute.rs
+++ b/compiler/rustc_macros/src/print_attribute.rs
@@ -4,7 +4,7 @@ use syn::spanned::Spanned;
 use syn::{Data, Fields, Ident};
 use synstructure::Structure;
 
-fn print_fields(name: &Ident, fields: &Fields) -> (TokenStream, TokenStream, TokenStream) {
+fn print_fields(name: &Ident, fields: &Fields) -> (TokenStream, TokenStream) {
     let string_name = name.to_string();
     let mut disps = vec![quote! {let mut __printed_anything = false;}];
 
@@ -43,7 +43,6 @@ fn print_fields(name: &Ident, fields: &Fields) -> (TokenStream, TokenStream, Tok
                     #(#disps)*
                     __p.word("}");
                 },
-                quote! { true },
             )
         }
         Fields::Unnamed(fields_unnamed) => {
@@ -76,10 +75,9 @@ fn print_fields(name: &Ident, fields: &Fields) -> (TokenStream, TokenStream, Tok
                     #(#disps)*
                     __p.pclose();
                 },
-                quote! { true },
             )
         }
-        Fields::Unit => (quote! {}, quote! { __p.word(#string_name) }, quote! { true }),
+        Fields::Unit => (quote! {}, quote! { __p.word(#string_name) }),
     }
 }
 
@@ -89,51 +87,33 @@ pub(crate) fn print_attribute(input: Structure<'_>) -> TokenStream {
     };
 
     // Must be applied to an enum type.
-    let (code, printed) = match &input.ast().data {
+    let code = match &input.ast().data {
         Data::Enum(e) => {
-            let (arms, printed) = e
+            let arms = e
                 .variants
                 .iter()
                 .map(|x| {
                     let ident = &x.ident;
-                    let (pat, code, printed) = print_fields(ident, &x.fields);
+                    let (pat, code) = print_fields(ident, &x.fields);
 
-                    (
-                        quote! {
-                            Self::#ident #pat => {#code}
-                        },
-                        quote! {
-                            Self::#ident #pat => {#printed}
-                        },
-                    )
+                    quote! {
+                        Self::#ident #pat => {#code}
+                    }
                 })
-                .unzip::<_, _, Vec<_>, Vec<_>>();
+                .collect::<Vec<_>>();
 
-            (
-                quote! {
-                    match self {
-                        #(#arms)*
-                    }
-                },
-                quote! {
-                    match self {
-                        #(#printed)*
-                    }
-                },
-            )
+            quote! {
+                match self {
+                    #(#arms)*
+                }
+            }
         }
         Data::Struct(s) => {
-            let (pat, code, printed) = print_fields(&input.ast().ident, &s.fields);
-            (
-                quote! {
-                    let Self #pat = self;
-                    #code
-                },
-                quote! {
-                    let Self #pat = self;
-                    #printed
-                },
-            )
+            let (pat, code) = print_fields(&input.ast().ident, &s.fields);
+            quote! {
+                let Self #pat = self;
+                #code
+            }
         }
         Data::Union(u) => {
             return span_error(u.union_token.span(), "can't derive PrintAttribute on unions");
@@ -144,7 +124,7 @@ pub(crate) fn print_attribute(input: Structure<'_>) -> TokenStream {
     input.gen_impl(quote! {
         #[allow(unused)]
         gen impl PrintAttribute for @Self {
-            fn should_render(&self) -> bool { #printed }
+            fn should_render(&self) -> bool { true }
             fn print_attribute(&self, __p: &mut rustc_ast_pretty::pp::Printer) { #code }
         }
     })
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 958e314efabb4..63f1b51df1c6b 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -701,7 +701,7 @@ impl<'tcx> Collector<'tcx> {
             .link_ordinal
             .map_or(import_name_type, |ord| Some(PeImportNameType::Ordinal(ord)));
 
-        let name = codegen_fn_attrs.link_name.unwrap_or_else(|| self.tcx.item_name(item));
+        let name = codegen_fn_attrs.symbol_name.unwrap_or_else(|| self.tcx.item_name(item));
 
         if self.tcx.sess.target.binary_format == BinaryFormat::Elf {
             let name = name.as_str();
diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
index 7d2fc0995aa0b..4de7814c8c757 100644
--- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
+++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
@@ -35,14 +35,10 @@ pub struct CodegenFnAttrs {
     pub inline: InlineAttr,
     /// Parsed representation of the `#[optimize]` attribute
     pub optimize: OptimizeAttr,
-    /// The `#[export_name = "..."]` attribute, indicating a custom symbol a
-    /// function should be exported under
-    pub export_name: Option<Symbol>,
-    /// The `#[link_name = "..."]` attribute, indicating a custom symbol an
-    /// imported function should be imported as. Note that `export_name`
-    /// probably isn't set when this is set, this is for foreign items while
-    /// `#[export_name]` is for Rust-defined functions.
-    pub link_name: Option<Symbol>,
+    /// The name this function will be imported/exported under. This can be set
+    /// using the `#[export_name = "..."]` or `#[link_name = "..."]` attribute
+    /// depending on if this is a function definition or foreign function.
+    pub symbol_name: Option<Symbol>,
     /// The `#[link_ordinal = "..."]` attribute, indicating an ordinal an
     /// imported function has in the dynamic library. Note that this must not
     /// be set when `link_name` is set. This is for foreign items with the
@@ -167,8 +163,7 @@ impl CodegenFnAttrs {
             flags: CodegenFnAttrFlags::empty(),
             inline: InlineAttr::None,
             optimize: OptimizeAttr::Default,
-            export_name: None,
-            link_name: None,
+            symbol_name: None,
             link_ordinal: None,
             target_features: vec![],
             safe_target_features: false,
@@ -196,7 +191,7 @@ impl CodegenFnAttrs {
 
         self.flags.contains(CodegenFnAttrFlags::NO_MANGLE)
             || self.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL)
-            || self.export_name.is_some()
+            || self.symbol_name.is_some()
             || match self.linkage {
                 // These are private, so make sure we don't try to consider
                 // them external.
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index c55c7fc6002c7..c977e5329c292 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -115,48 +115,6 @@ impl MirPhase {
             MirPhase::Runtime(runtime_phase) => (3, 1 + runtime_phase as usize),
         }
     }
-
-    /// Parses a `MirPhase` from a pair of strings. Panics if this isn't possible for any reason.
-    pub fn parse(dialect: String, phase: Option<String>) -> Self {
-        match &*dialect.to_ascii_lowercase() {
-            "built" => {
-                assert!(phase.is_none(), "Cannot specify a phase for `Built` MIR");
-                MirPhase::Built
-            }
-            "analysis" => Self::Analysis(AnalysisPhase::parse(phase)),
-            "runtime" => Self::Runtime(RuntimePhase::parse(phase)),
-            _ => bug!("Unknown MIR dialect: '{}'", dialect),
-        }
-    }
-}
-
-impl AnalysisPhase {
-    pub fn parse(phase: Option<String>) -> Self {
-        let Some(phase) = phase else {
-            return Self::Initial;
-        };
-
-        match &*phase.to_ascii_lowercase() {
-            "initial" => Self::Initial,
-            "post_cleanup" | "post-cleanup" | "postcleanup" => Self::PostCleanup,
-            _ => bug!("Unknown analysis phase: '{}'", phase),
-        }
-    }
-}
-
-impl RuntimePhase {
-    pub fn parse(phase: Option<String>) -> Self {
-        let Some(phase) = phase else {
-            return Self::Initial;
-        };
-
-        match &*phase.to_ascii_lowercase() {
-            "initial" => Self::Initial,
-            "post_cleanup" | "post-cleanup" | "postcleanup" => Self::PostCleanup,
-            "optimized" => Self::Optimized,
-            _ => bug!("Unknown runtime phase: '{}'", phase),
-        }
-    }
 }
 
 /// Where a specific `mir::Body` comes from.
diff --git a/compiler/rustc_middle/src/query/on_disk_cache.rs b/compiler/rustc_middle/src/query/on_disk_cache.rs
index a7ac34428986e..546791135ba61 100644
--- a/compiler/rustc_middle/src/query/on_disk_cache.rs
+++ b/compiler/rustc_middle/src/query/on_disk_cache.rs
@@ -645,34 +645,29 @@ impl<'a, 'tcx> SpanDecoder for CacheDecoder<'a, 'tcx> {
         let parent = Option::<LocalDefId>::decode(self);
         let tag: u8 = Decodable::decode(self);
 
-        if tag == TAG_PARTIAL_SPAN {
-            return Span::new(BytePos(0), BytePos(0), ctxt, parent);
-        } else if tag == TAG_RELATIVE_SPAN {
-            let dlo = u32::decode(self);
-            let dto = u32::decode(self);
-
-            let enclosing = self.tcx.source_span_untracked(parent.unwrap()).data_untracked();
-            let span = Span::new(
-                enclosing.lo + BytePos::from_u32(dlo),
-                enclosing.lo + BytePos::from_u32(dto),
-                ctxt,
-                parent,
-            );
-
-            return span;
-        } else {
-            debug_assert_eq!(tag, TAG_FULL_SPAN);
-        }
-
-        let file_lo_index = SourceFileIndex::decode(self);
-        let line_lo = usize::decode(self);
-        let col_lo = RelativeBytePos::decode(self);
-        let len = BytePos::decode(self);
-
-        let file_lo = self.file_index_to_file(file_lo_index);
-        let lo = file_lo.lines()[line_lo - 1] + col_lo;
-        let lo = file_lo.absolute_position(lo);
-        let hi = lo + len;
+        let (lo, hi) = match tag {
+            TAG_PARTIAL_SPAN => (BytePos(0), BytePos(0)),
+            TAG_RELATIVE_SPAN => {
+                let dlo = u32::decode(self);
+                let dto = u32::decode(self);
+
+                let enclosing = self.tcx.source_span_untracked(parent.unwrap()).data_untracked();
+                (enclosing.lo + BytePos::from_u32(dlo), enclosing.lo + BytePos::from_u32(dto))
+            }
+            TAG_FULL_SPAN => {
+                let file_lo_index = SourceFileIndex::decode(self);
+                let line_lo = usize::decode(self);
+                let col_lo = RelativeBytePos::decode(self);
+                let len = BytePos::decode(self);
+
+                let file_lo = self.file_index_to_file(file_lo_index);
+                let lo = file_lo.lines()[line_lo - 1] + col_lo;
+                let lo = file_lo.absolute_position(lo);
+                let hi = lo + len;
+                (lo, hi)
+            }
+            _ => unreachable!(),
+        };
 
         Span::new(lo, hi, ctxt, parent)
     }
diff --git a/compiler/rustc_mir_build/src/builder/custom/mod.rs b/compiler/rustc_mir_build/src/builder/custom/mod.rs
index 902a6e7f115be..792ad6d782cf3 100644
--- a/compiler/rustc_mir_build/src/builder/custom/mod.rs
+++ b/compiler/rustc_mir_build/src/builder/custom/mod.rs
@@ -19,10 +19,10 @@
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{Attribute, HirId};
+use rustc_hir::{HirId, attrs};
 use rustc_index::{IndexSlice, IndexVec};
+use rustc_middle::bug;
 use rustc_middle::mir::*;
-use rustc_middle::span_bug;
 use rustc_middle::thir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::Span;
@@ -39,7 +39,8 @@ pub(super) fn build_custom_mir<'tcx>(
     return_ty: Ty<'tcx>,
     return_ty_span: Span,
     span: Span,
-    attr: &Attribute,
+    dialect: Option<attrs::MirDialect>,
+    phase: Option<attrs::MirPhase>,
 ) -> Body<'tcx> {
     let mut body = Body {
         basic_blocks: BasicBlocks::new(IndexVec::new()),
@@ -72,7 +73,7 @@ pub(super) fn build_custom_mir<'tcx>(
         inlined_parent_scope: None,
         local_data: ClearCrossCrate::Set(SourceScopeLocalData { lint_root: hir_id }),
     });
-    body.injection_phase = Some(parse_attribute(attr));
+    body.injection_phase = Some(parse_attribute(dialect, phase));
 
     let mut pctxt = ParseCtxt {
         tcx,
@@ -98,40 +99,38 @@ pub(super) fn build_custom_mir<'tcx>(
     body
 }
 
-fn parse_attribute(attr: &Attribute) -> MirPhase {
-    let meta_items = attr.meta_item_list().unwrap();
-    let mut dialect: Option<String> = None;
-    let mut phase: Option<String> = None;
-
-    // Not handling errors properly for this internal attribute; will just abort on errors.
-    for nested in meta_items {
-        let name = nested.name().unwrap();
-        let value = nested.value_str().unwrap().as_str().to_string();
-        match name.as_str() {
-            "dialect" => {
-                assert!(dialect.is_none());
-                dialect = Some(value);
-            }
-            "phase" => {
-                assert!(phase.is_none());
-                phase = Some(value);
-            }
-            other => {
-                span_bug!(
-                    nested.span(),
-                    "Unexpected key while parsing custom_mir attribute: '{}'",
-                    other
-                );
-            }
-        }
-    }
-
+/// Turns the arguments passed to `#[custom_mir(..)]` into a proper
+/// [`MirPhase`]. Panics if this isn't possible for any reason.
+fn parse_attribute(dialect: Option<attrs::MirDialect>, phase: Option<attrs::MirPhase>) -> MirPhase {
     let Some(dialect) = dialect else {
+        // Caught during attribute checking.
         assert!(phase.is_none());
         return MirPhase::Built;
     };
 
-    MirPhase::parse(dialect, phase)
+    match dialect {
+        attrs::MirDialect::Built => {
+            // Caught during attribute checking.
+            assert!(phase.is_none(), "Cannot specify a phase for `Built` MIR");
+            MirPhase::Built
+        }
+        attrs::MirDialect::Analysis => match phase {
+            None | Some(attrs::MirPhase::Initial) => MirPhase::Analysis(AnalysisPhase::Initial),
+
+            Some(attrs::MirPhase::PostCleanup) => MirPhase::Analysis(AnalysisPhase::PostCleanup),
+
+            Some(attrs::MirPhase::Optimized) => {
+                // Caught during attribute checking.
+                bug!("`optimized` dialect is not compatible with the `analysis` dialect")
+            }
+        },
+
+        attrs::MirDialect::Runtime => match phase {
+            None | Some(attrs::MirPhase::Initial) => MirPhase::Runtime(RuntimePhase::Initial),
+            Some(attrs::MirPhase::PostCleanup) => MirPhase::Runtime(RuntimePhase::PostCleanup),
+            Some(attrs::MirPhase::Optimized) => MirPhase::Runtime(RuntimePhase::Optimized),
+        },
+    }
 }
 
 struct ParseCtxt<'a, 'tcx> {
diff --git a/compiler/rustc_mir_build/src/builder/mod.rs b/compiler/rustc_mir_build/src/builder/mod.rs
index 855cd2f3bc0a6..9570760f94319 100644
--- a/compiler/rustc_mir_build/src/builder/mod.rs
+++ b/compiler/rustc_mir_build/src/builder/mod.rs
@@ -11,9 +11,10 @@ use rustc_ast::attr;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sorted_map::SortedIndexMultiMap;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::{self as hir, BindingMode, ByRef, HirId, ItemLocalId, Node};
+use rustc_hir::{self as hir, BindingMode, ByRef, HirId, ItemLocalId, Node, find_attr};
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
@@ -479,8 +480,7 @@ fn construct_fn<'tcx>(
         ty => span_bug!(span_with_body, "unexpected type of body: {ty:?}"),
     };
 
-    if let Some(custom_mir_attr) =
-        tcx.hir_attrs(fn_id).iter().find(|attr| attr.has_name(sym::custom_mir))
+    if let Some((dialect, phase)) = find_attr!(tcx.hir_attrs(fn_id), AttributeKind::CustomMir(dialect, phase, _) => (dialect, phase))
     {
         return custom::build_custom_mir(
             tcx,
@@ -492,7 +492,8 @@ fn construct_fn<'tcx>(
             return_ty,
             return_ty_span,
             span_with_body,
-            custom_mir_attr,
+            dialect.as_ref().map(|(d, _)| *d),
+            phase.as_ref().map(|(p, _)| *p),
         );
     }
 
diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 0b6b36640e92b..cdab785e84263 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -5,8 +5,9 @@ use std::ops::Bound;
 use rustc_ast::AsmMacro;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::DiagArgValue;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::DefKind;
-use rustc_hir::{self as hir, BindingMode, ByRef, HirId, Mutability};
+use rustc_hir::{self as hir, BindingMode, ByRef, HirId, Mutability, find_attr};
 use rustc_middle::middle::codegen_fn_attrs::TargetFeature;
 use rustc_middle::mir::BorrowKind;
 use rustc_middle::span_bug;
@@ -1157,7 +1158,7 @@ pub(crate) fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
     // Closures and inline consts are handled by their owner, if it has a body
     assert!(!tcx.is_typeck_child(def.to_def_id()));
     // Also, don't safety check custom MIR
-    if tcx.has_attr(def, sym::custom_mir) {
+    if find_attr!(tcx.get_all_attrs(def), AttributeKind::CustomMir(..) => ()).is_some() {
         return;
     }
 
diff --git a/compiler/rustc_mir_build/src/thir/cx/mod.rs b/compiler/rustc_mir_build/src/thir/cx/mod.rs
index 24d4136c64237..9657c4dc839d6 100644
--- a/compiler/rustc_mir_build/src/thir/cx/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/mod.rs
@@ -4,11 +4,11 @@
 
 use rustc_data_structures::steal::Steal;
 use rustc_errors::ErrorGuaranteed;
-use rustc_hir as hir;
-use rustc_hir::HirId;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
+use rustc_hir::{self as hir, HirId, find_attr};
 use rustc_middle::bug;
 use rustc_middle::middle::region;
 use rustc_middle::thir::*;
@@ -111,10 +111,8 @@ impl<'tcx> ThirBuildCx<'tcx> {
             typeck_results,
             rvalue_scopes: &typeck_results.rvalue_scopes,
             body_owner: def.to_def_id(),
-            apply_adjustments: tcx
-                .hir_attrs(hir_id)
-                .iter()
-                .all(|attr| !attr.has_name(rustc_span::sym::custom_mir)),
+            apply_adjustments:
+                !find_attr!(tcx.hir_attrs(hir_id), AttributeKind::CustomMir(..) => ()).is_some(),
         }
     }
 
diff --git a/compiler/rustc_next_trait_solver/src/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
index 1bc35e599c706..3e1f48610ffc0 100644
--- a/compiler/rustc_next_trait_solver/src/canonicalizer.rs
+++ b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
@@ -27,7 +27,7 @@ enum CanonicalizeInputKind {
     ParamEnv,
     /// When canonicalizing predicates, we don't keep `'static`. If we're
     /// currently outside of the trait solver and canonicalize the root goal
-    /// during HIR typeck, we replace each occurance of a region with a
+    /// during HIR typeck, we replace each occurrence of a region with a
     /// unique region variable. See the comment on `InferCtxt::in_hir_typeck`
     /// for more details.
     Predicate { is_hir_typeck_root_goal: bool },
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
index 7481b0ea96018..f7a5ba8194b11 100644
--- a/compiler/rustc_passes/messages.ftl
+++ b/compiler/rustc_passes/messages.ftl
@@ -74,6 +74,16 @@ passes_const_stable_not_stable =
     attribute `#[rustc_const_stable]` can only be applied to functions that are declared `#[stable]`
     .label = attribute specified here
 
+passes_custom_mir_incompatible_dialect_and_phase =
+    The {$dialect} dialect is not compatible with the {$phase} phase
+    .dialect_span = this dialect...
+    .phase_span = ... is not compatible with this phase
+
+passes_custom_mir_phase_requires_dialect =
+    `dialect` key required
+    .phase_span = `phase` argument requires a `dialect` argument
+
+
 passes_dead_codes =
     { $multiple ->
       *[true] multiple {$descr}s are
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 0e28c51e981f8..3c329d2070089 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -18,7 +18,7 @@ use rustc_feature::{
     ACCEPTED_LANG_FEATURES, AttributeDuplicates, AttributeType, BUILTIN_ATTRIBUTE_MAP,
     BuiltinAttribute,
 };
-use rustc_hir::attrs::{AttributeKind, InlineAttr, ReprAttr};
+use rustc_hir::attrs::{AttributeKind, InlineAttr, MirDialect, MirPhase, ReprAttr};
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalModDefId;
 use rustc_hir::intravisit::{self, Visitor};
@@ -197,6 +197,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 Attribute::Parsed(AttributeKind::MustUse { span, .. }) => {
                     self.check_must_use(hir_id, *span, target)
                 }
+                &Attribute::Parsed(AttributeKind::CustomMir(dialect, phase, attr_span)) => {
+                    self.check_custom_mir(dialect, phase, attr_span)
+                }
                 Attribute::Parsed(
                     AttributeKind::BodyStability { .. }
                     | AttributeKind::ConstStabilityIndirect
@@ -248,7 +251,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::Coroutine(..)
                     | AttributeKind::Linkage(..),
                 ) => { /* do nothing  */ }
-
                 Attribute::Unparsed(attr_item) => {
                     style = Some(attr_item.style);
                     match attr.path().as_slice() {
@@ -331,8 +333,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::panic_handler
                             | sym::lang
                             | sym::needs_allocator
-                            | sym::default_lib_allocator
-                            | sym::custom_mir,
+                            | sym::default_lib_allocator,
                             ..
                         ] => {}
                         [name, rest@..] => {
@@ -2113,6 +2114,48 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
             self.dcx().emit_err(errors::ConstContinueAttr { attr_span, node_span });
         };
     }
+
+    fn check_custom_mir(
+        &self,
+        dialect: Option<(MirDialect, Span)>,
+        phase: Option<(MirPhase, Span)>,
+        attr_span: Span,
+    ) {
+        let Some((dialect, dialect_span)) = dialect else {
+            if let Some((_, phase_span)) = phase {
+                self.dcx()
+                    .emit_err(errors::CustomMirPhaseRequiresDialect { attr_span, phase_span });
+            }
+            return;
+        };
+
+        match dialect {
+            MirDialect::Analysis => {
+                if let Some((MirPhase::Optimized, phase_span)) = phase {
+                    self.dcx().emit_err(errors::CustomMirIncompatibleDialectAndPhase {
+                        dialect,
+                        phase: MirPhase::Optimized,
+                        attr_span,
+                        dialect_span,
+                        phase_span,
+                    });
+                }
+            }
+
+            MirDialect::Built => {
+                if let Some((phase, phase_span)) = phase {
+                    self.dcx().emit_err(errors::CustomMirIncompatibleDialectAndPhase {
+                        dialect,
+                        phase,
+                        attr_span,
+                        dialect_span,
+                        phase_span,
+                    });
+                }
+            }
+            MirDialect::Runtime => {}
+        }
+    }
 }
 
 impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index c5d5155d0e5a5..f8ecf10714a47 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -7,6 +7,7 @@ use rustc_errors::{
     MultiSpan, Subdiagnostic,
 };
 use rustc_hir::Target;
+use rustc_hir::attrs::{MirDialect, MirPhase};
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::{MainDefinition, Ty};
 use rustc_span::{DUMMY_SP, Span, Symbol};
@@ -1570,3 +1571,25 @@ pub(crate) struct ReprAlignShouldBeAlign {
     pub span: Span,
     pub item: &'static str,
 }
+
+#[derive(Diagnostic)]
+#[diag(passes_custom_mir_phase_requires_dialect)]
+pub(crate) struct CustomMirPhaseRequiresDialect {
+    #[primary_span]
+    pub attr_span: Span,
+    #[label]
+    pub phase_span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_custom_mir_incompatible_dialect_and_phase)]
+pub(crate) struct CustomMirIncompatibleDialectAndPhase {
+    pub dialect: MirDialect,
+    pub phase: MirPhase,
+    #[primary_span]
+    pub attr_span: Span,
+    #[label]
+    pub dialect_span: Span,
+    #[label]
+    pub phase_span: Span,
+}
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 7c93fdb88ee44..2ecabb33763cc 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -866,7 +866,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             }
             ImportKind::Glob { .. } => {
                 // FIXME: Use mutable resolver directly as a hack, this should be an output of
-                // specualtive resolution.
+                // speculative resolution.
                 self.get_mut_unchecked().resolve_glob_import(import);
                 return 0;
             }
@@ -903,7 +903,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         // We need the `target`, `source` can be extracted.
                         let imported_binding = this.import(binding, import);
                         // FIXME: Use mutable resolver directly as a hack, this should be an output of
-                        // specualtive resolution.
+                        // speculative resolution.
                         this.get_mut_unchecked().define_binding_local(
                             parent,
                             target,
@@ -917,7 +917,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         if target.name != kw::Underscore {
                             let key = BindingKey::new(target, ns);
                             // FIXME: Use mutable resolver directly as a hack, this should be an output of
-                            // specualtive resolution.
+                            // speculative resolution.
                             this.get_mut_unchecked().update_local_resolution(
                                 parent,
                                 key,
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 5200f9340e115..679e663f88614 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -4270,7 +4270,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                         if path.len() == 2
                             && let [segment] = prefix_path
                         {
-                            // Delay to check whether methond name is an associated function or not
+                            // Delay to check whether method name is an associated function or not
                             // ```
                             // let foo = Foo {};
                             // foo::bar(); // possibly suggest to foo.bar();
diff --git a/compiler/rustc_span/src/caching_source_map_view.rs b/compiler/rustc_span/src/caching_source_map_view.rs
index a887b50ec1ebe..41cfaa3ee34e5 100644
--- a/compiler/rustc_span/src/caching_source_map_view.rs
+++ b/compiler/rustc_span/src/caching_source_map_view.rs
@@ -123,27 +123,25 @@ impl<'sm> CachingSourceMapView<'sm> {
 
         if lo_cache_idx != -1 && hi_cache_idx != -1 {
             // Cache hit for span lo and hi. Check if they belong to the same file.
-            let result = {
-                let lo = &self.line_cache[lo_cache_idx as usize];
-                let hi = &self.line_cache[hi_cache_idx as usize];
+            let lo_file_index = self.line_cache[lo_cache_idx as usize].file_index;
+            let hi_file_index = self.line_cache[hi_cache_idx as usize].file_index;
 
-                if lo.file_index != hi.file_index {
-                    return None;
-                }
-
-                (
-                    lo.file.stable_id,
-                    lo.line_number,
-                    span_data.lo - lo.line.start,
-                    hi.line_number,
-                    span_data.hi - hi.line.start,
-                )
-            };
+            if lo_file_index != hi_file_index {
+                return None;
+            }
 
             self.line_cache[lo_cache_idx as usize].touch(self.time_stamp);
             self.line_cache[hi_cache_idx as usize].touch(self.time_stamp);
 
-            return Some(result);
+            let lo = &self.line_cache[lo_cache_idx as usize];
+            let hi = &self.line_cache[hi_cache_idx as usize];
+            return Some((
+                lo.file.stable_id,
+                lo.line_number,
+                span_data.lo - lo.line.start,
+                hi.line_number,
+                span_data.hi - hi.line.start,
+            ));
         }
 
         // No cache hit or cache hit for only one of span lo and hi.
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index f4a6d0f5891cf..42ca2cb417542 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -447,6 +447,7 @@ symbols! {
         altivec,
         alu32,
         always,
+        analysis,
         and,
         and_then,
         anon,
@@ -589,6 +590,7 @@ symbols! {
         btreemap_contains_key,
         btreemap_insert,
         btreeset_iter,
+        built,
         builtin_syntax,
         c,
         c_dash_variadic,
@@ -855,6 +857,7 @@ symbols! {
         destructuring_assignment,
         diagnostic,
         diagnostic_namespace,
+        dialect,
         direct,
         discriminant_kind,
         discriminant_type,
@@ -1211,6 +1214,7 @@ symbols! {
         infer_static_outlives_requirements,
         inherent_associated_types,
         inherit,
+        initial,
         inlateout,
         inline,
         inline_const,
@@ -1546,6 +1550,7 @@ symbols! {
         opt_out_copy,
         optimize,
         optimize_attribute,
+        optimized,
         optin_builtin_traits,
         option,
         option_env,
@@ -1628,6 +1633,7 @@ symbols! {
         pattern_types,
         permissions_from_mode,
         phantom_data,
+        phase,
         pic,
         pie,
         pin,
@@ -1644,6 +1650,7 @@ symbols! {
         poll,
         poll_next,
         position,
+        post_cleanup: "post-cleanup",
         post_dash_lto: "post-lto",
         postfix_match,
         powerpc_target_feature,
@@ -1807,6 +1814,7 @@ symbols! {
         roundf128,
         rt,
         rtm_target_feature,
+        runtime,
         rust,
         rust_2015,
         rust_2018,
diff --git a/compiler/rustc_symbol_mangling/src/lib.rs b/compiler/rustc_symbol_mangling/src/lib.rs
index f3c96f641902e..d97ee95652530 100644
--- a/compiler/rustc_symbol_mangling/src/lib.rs
+++ b/compiler/rustc_symbol_mangling/src/lib.rs
@@ -193,29 +193,20 @@ fn compute_symbol_name<'tcx>(
         // defining crate.
         // Weak lang items automatically get #[rustc_std_internal_symbol]
         // applied by the code computing the CodegenFnAttrs.
-        // We are mangling all #[rustc_std_internal_symbol] items that don't
-        // also have #[no_mangle] as a combination of the rustc version and the
-        // unmangled linkage name. This is to ensure that if we link against a
-        // staticlib compiled by a different rustc version, we don't get symbol
-        // conflicts or even UB due to a different implementation/ABI. Rust
-        // staticlibs currently export all symbols, including those that are
-        // hidden in cdylibs.
+        // We are mangling all #[rustc_std_internal_symbol] items as a
+        // combination of the rustc version and the unmangled linkage name.
+        // This is to ensure that if we link against a staticlib compiled by a
+        // different rustc version, we don't get symbol conflicts or even UB
+        // due to a different implementation/ABI. Rust staticlibs currently
+        // export all symbols, including those that are hidden in cdylibs.
         // We are using the v0 symbol mangling scheme here as we need to be
         // consistent across all crates and in some contexts the legacy symbol
         // mangling scheme can't be used. For example both the GCC backend and
         // Rust-for-Linux don't support some of the characters used by the
         // legacy symbol mangling scheme.
-        let name = if tcx.is_foreign_item(def_id) {
-            if let Some(name) = attrs.link_name { name } else { tcx.item_name(def_id) }
-        } else {
-            if let Some(name) = attrs.export_name { name } else { tcx.item_name(def_id) }
-        };
+        let name = if let Some(name) = attrs.symbol_name { name } else { tcx.item_name(def_id) };
 
-        if attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE) {
-            return name.to_string();
-        } else {
-            return v0::mangle_internal_symbol(tcx, name.as_str());
-        }
+        return v0::mangle_internal_symbol(tcx, name.as_str());
     }
 
     let wasm_import_module_exception_force_mangling = {
@@ -240,23 +231,16 @@ fn compute_symbol_name<'tcx>(
             && tcx.wasm_import_module_map(LOCAL_CRATE).contains_key(&def_id.into())
     };
 
-    if let Some(name) = attrs.link_name
-        && !wasm_import_module_exception_force_mangling
-    {
-        // Use provided name
-        return name.to_string();
-    }
-
-    if let Some(name) = attrs.export_name {
-        // Use provided name
-        return name.to_string();
-    }
+    if !wasm_import_module_exception_force_mangling {
+        if let Some(name) = attrs.symbol_name {
+            // Use provided name
+            return name.to_string();
+        }
 
-    if attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE)
-        && !wasm_import_module_exception_force_mangling
-    {
-        // Don't mangle
-        return tcx.item_name(def_id).to_string();
+        if attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE) {
+            // Don't mangle
+            return tcx.item_name(def_id).to_string();
+        }
     }
 
     // If we're dealing with an instance of a function that's inlined from
diff --git a/library/core/src/net/ip_addr.rs b/library/core/src/net/ip_addr.rs
index 87f2110034c5a..3bf113d017ca9 100644
--- a/library/core/src/net/ip_addr.rs
+++ b/library/core/src/net/ip_addr.rs
@@ -626,13 +626,13 @@ impl Ipv4Addr {
     /// # Examples
     ///
     /// ```
-    /// #![feature(ip_from)]
     /// use std::net::Ipv4Addr;
     ///
     /// let addr = Ipv4Addr::from_octets([13u8, 12u8, 11u8, 10u8]);
     /// assert_eq!(Ipv4Addr::new(13, 12, 11, 10), addr);
     /// ```
-    #[unstable(feature = "ip_from", issue = "131360")]
+    #[stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_octets(octets: [u8; 4]) -> Ipv4Addr {
@@ -1464,7 +1464,6 @@ impl Ipv6Addr {
     /// # Examples
     ///
     /// ```
-    /// #![feature(ip_from)]
     /// use std::net::Ipv6Addr;
     ///
     /// let addr = Ipv6Addr::from_segments([
@@ -1479,7 +1478,8 @@ impl Ipv6Addr {
     ///     addr
     /// );
     /// ```
-    #[unstable(feature = "ip_from", issue = "131360")]
+    #[stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_segments(segments: [u16; 8]) -> Ipv6Addr {
@@ -2029,7 +2029,6 @@ impl Ipv6Addr {
     /// # Examples
     ///
     /// ```
-    /// #![feature(ip_from)]
     /// use std::net::Ipv6Addr;
     ///
     /// let addr = Ipv6Addr::from_octets([
@@ -2044,7 +2043,8 @@ impl Ipv6Addr {
     ///     addr
     /// );
     /// ```
-    #[unstable(feature = "ip_from", issue = "131360")]
+    #[stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "ip_from", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_octets(octets: [u8; 16]) -> Ipv6Addr {
diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs
index ecda8a7fec68f..b128acfc00083 100644
--- a/library/coretests/tests/lib.rs
+++ b/library/coretests/tests/lib.rs
@@ -56,7 +56,6 @@
 #![feature(hashmap_internals)]
 #![feature(int_roundings)]
 #![feature(ip)]
-#![feature(ip_from)]
 #![feature(is_ascii_octdigit)]
 #![feature(isolate_most_least_significant_one)]
 #![feature(iter_advance_by)]
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index a220a3f56e9a8..d4a584f4d14ff 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -3119,7 +3119,7 @@ pub fn read_dir<P: AsRef<Path>>(path: P) -> io::Result<ReadDir> {
 /// On UNIX-like systems, this function will update the permission bits
 /// of the file pointed to by the symlink.
 ///
-/// Note that this behavior can lead to privalage escalation vulnerabilities,
+/// Note that this behavior can lead to privilege escalation vulnerabilities,
 /// where the ability to create a symlink in one directory allows you to
 /// cause the permissions of another file or directory to be modified.
 ///
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 3b52804d6be40..23e957484a5ad 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -2105,6 +2105,38 @@ impl PartialEq for PathBuf {
     }
 }
 
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<str> for PathBuf {
+    #[inline]
+    fn eq(&self, other: &str) -> bool {
+        &*self == other
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<PathBuf> for str {
+    #[inline]
+    fn eq(&self, other: &PathBuf) -> bool {
+        other == self
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<String> for PathBuf {
+    #[inline]
+    fn eq(&self, other: &String) -> bool {
+        **self == **other
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<PathBuf> for String {
+    #[inline]
+    fn eq(&self, other: &PathBuf) -> bool {
+        other == self
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Hash for PathBuf {
     fn hash<H: Hasher>(&self, h: &mut H) {
@@ -3366,6 +3398,39 @@ impl PartialEq for Path {
     }
 }
 
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<str> for Path {
+    #[inline]
+    fn eq(&self, other: &str) -> bool {
+        let other: &OsStr = other.as_ref();
+        self == other
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<Path> for str {
+    #[inline]
+    fn eq(&self, other: &Path) -> bool {
+        other == self
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<String> for Path {
+    #[inline]
+    fn eq(&self, other: &String) -> bool {
+        self == &*other
+    }
+}
+
+#[stable(feature = "eq_str_for_path", since = "CURRENT_RUSTC_VERSION")]
+impl cmp::PartialEq<Path> for String {
+    #[inline]
+    fn eq(&self, other: &Path) -> bool {
+        other == self
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Hash for Path {
     fn hash<H: Hasher>(&self, h: &mut H) {
diff --git a/library/std/src/sync/nonpoison/mutex.rs b/library/std/src/sync/nonpoison/mutex.rs
index b6861c78f001d..fd1e671d7a3d3 100644
--- a/library/std/src/sync/nonpoison/mutex.rs
+++ b/library/std/src/sync/nonpoison/mutex.rs
@@ -100,7 +100,7 @@ pub struct MutexGuard<'a, T: ?Sized + 'a> {
     lock: &'a Mutex<T>,
 }
 
-/// A [`MutexGuard`] is not `Send` to maximize platform portablity.
+/// A [`MutexGuard`] is not `Send` to maximize platform portability.
 ///
 /// On platforms that use POSIX threads (commonly referred to as pthreads) there is a requirement to
 /// release mutex locks on the same thread they were acquired.
diff --git a/library/std/src/sync/poison/mutex.rs b/library/std/src/sync/poison/mutex.rs
index 6205c4fa4ca4b..720c212c65cf7 100644
--- a/library/std/src/sync/poison/mutex.rs
+++ b/library/std/src/sync/poison/mutex.rs
@@ -279,7 +279,7 @@ pub struct MutexGuard<'a, T: ?Sized + 'a> {
     poison: poison::Guard,
 }
 
-/// A [`MutexGuard`] is not `Send` to maximize platform portablity.
+/// A [`MutexGuard`] is not `Send` to maximize platform portability.
 ///
 /// On platforms that use POSIX threads (commonly referred to as pthreads) there is a requirement to
 /// release mutex locks on the same thread they were acquired.
diff --git a/library/std/src/sys/fs/unix.rs b/library/std/src/sys/fs/unix.rs
index b310db2dac485..4643ced9ad818 100644
--- a/library/std/src/sys/fs/unix.rs
+++ b/library/std/src/sys/fs/unix.rs
@@ -1263,6 +1263,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn lock(&self) -> io::Result<()> {
@@ -1275,6 +1276,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn lock(&self) -> io::Result<()> {
@@ -1286,6 +1288,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn lock_shared(&self) -> io::Result<()> {
@@ -1298,6 +1301,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn lock_shared(&self) -> io::Result<()> {
@@ -1309,6 +1313,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn try_lock(&self) -> Result<(), TryLockError> {
@@ -1329,6 +1334,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn try_lock(&self) -> Result<(), TryLockError> {
@@ -1343,6 +1349,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn try_lock_shared(&self) -> Result<(), TryLockError> {
@@ -1363,6 +1370,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn try_lock_shared(&self) -> Result<(), TryLockError> {
@@ -1377,6 +1385,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn unlock(&self) -> io::Result<()> {
@@ -1389,6 +1398,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn unlock(&self) -> io::Result<()> {
diff --git a/library/std/src/sys/mod.rs b/library/std/src/sys/mod.rs
index 8ec0a0e33023f..6324c1a232af4 100644
--- a/library/std/src/sys/mod.rs
+++ b/library/std/src/sys/mod.rs
@@ -1,7 +1,7 @@
 #![allow(unsafe_op_in_unsafe_fn)]
 
 /// The configure builtins provides runtime support compiler-builtin features
-/// which require dynamic intialization to work as expected, e.g. aarch64
+/// which require dynamic initialization to work as expected, e.g. aarch64
 /// outline-atomics.
 mod configure_builtins;
 
diff --git a/library/std/src/sys/pal/uefi/time.rs b/library/std/src/sys/pal/uefi/time.rs
index df5611b2dddc1..748178659412f 100644
--- a/library/std/src/sys/pal/uefi/time.rs
+++ b/library/std/src/sys/pal/uefi/time.rs
@@ -188,7 +188,7 @@ pub(crate) mod system_time_internal {
         Duration::new(epoch, t.nanosecond)
     }
 
-    /// This algorithm is a modifed version of the one described in the post:
+    /// This algorithm is a modified version of the one described in the post:
     /// https://howardhinnant.github.io/date_algorithms.html#clive_from_days
     ///
     /// The changes are to use 1900-01-01-00:00:00 with timezone -1440 as anchor instead of UNIX
@@ -197,7 +197,7 @@ pub(crate) mod system_time_internal {
         // Check timzone validity
         assert!(timezone <= 1440 && timezone >= -1440);
 
-        // FIXME(#126043): use checked_sub_signed once stablized
+        // FIXME(#126043): use checked_sub_signed once stabilized
         let secs =
             dur.as_secs().checked_add_signed((-timezone as i64) * SECS_IN_MINUTE as i64).unwrap();
 
diff --git a/src/bootstrap/src/core/build_steps/dist.rs b/src/bootstrap/src/core/build_steps/dist.rs
index 414f4464d1edf..133e6f894afd8 100644
--- a/src/bootstrap/src/core/build_steps/dist.rs
+++ b/src/bootstrap/src/core/build_steps/dist.rs
@@ -916,6 +916,12 @@ fn copy_src_dirs(
     exclude_dirs: &[&str],
     dst_dir: &Path,
 ) {
+    // The src directories should be relative to `base`, we depend on them not being absolute
+    // paths below.
+    for src_dir in src_dirs {
+        assert!(Path::new(src_dir).is_relative());
+    }
+
     // Iterating, filtering and copying a large number of directories can be quite slow.
     // Avoid doing it in dry run (and thus also tests).
     if builder.config.dry_run() {
@@ -923,6 +929,7 @@ fn copy_src_dirs(
     }
 
     fn filter_fn(exclude_dirs: &[&str], dir: &str, path: &Path) -> bool {
+        // The paths are relative, e.g. `llvm-project/...`.
         let spath = match path.to_str() {
             Some(path) => path,
             None => return false,
@@ -930,65 +937,53 @@ fn copy_src_dirs(
         if spath.ends_with('~') || spath.ends_with(".pyc") {
             return false;
         }
+        // Normalize slashes
+        let spath = spath.replace("\\", "/");
 
-        const LLVM_PROJECTS: &[&str] = &[
+        static LLVM_PROJECTS: &[&str] = &[
             "llvm-project/clang",
-            "llvm-project\\clang",
             "llvm-project/libunwind",
-            "llvm-project\\libunwind",
             "llvm-project/lld",
-            "llvm-project\\lld",
             "llvm-project/lldb",
-            "llvm-project\\lldb",
             "llvm-project/llvm",
-            "llvm-project\\llvm",
             "llvm-project/compiler-rt",
-            "llvm-project\\compiler-rt",
             "llvm-project/cmake",
-            "llvm-project\\cmake",
             "llvm-project/runtimes",
-            "llvm-project\\runtimes",
             "llvm-project/third-party",
-            "llvm-project\\third-party",
         ];
-        if spath.contains("llvm-project")
-            && !spath.ends_with("llvm-project")
-            && !LLVM_PROJECTS.iter().any(|path| spath.contains(path))
-        {
-            return false;
-        }
+        if spath.starts_with("llvm-project") && spath != "llvm-project" {
+            if !LLVM_PROJECTS.iter().any(|path| spath.starts_with(path)) {
+                return false;
+            }
 
-        // Keep only these third party libraries
-        const LLVM_THIRD_PARTY: &[&str] =
-            &["llvm-project/third-party/siphash", "llvm-project\\third-party\\siphash"];
-        if (spath.starts_with("llvm-project/third-party")
-            || spath.starts_with("llvm-project\\third-party"))
-            && !(spath.ends_with("llvm-project/third-party")
-                || spath.ends_with("llvm-project\\third-party"))
-            && !LLVM_THIRD_PARTY.iter().any(|path| spath.contains(path))
-        {
-            return false;
-        }
+            // Keep siphash third-party dependency
+            if spath.starts_with("llvm-project/third-party")
+                && spath != "llvm-project/third-party"
+                && !spath.starts_with("llvm-project/third-party/siphash")
+            {
+                return false;
+            }
 
-        const LLVM_TEST: &[&str] = &["llvm-project/llvm/test", "llvm-project\\llvm\\test"];
-        if LLVM_TEST.iter().any(|path| spath.contains(path))
-            && (spath.ends_with(".ll") || spath.ends_with(".td") || spath.ends_with(".s"))
-        {
-            return false;
+            if spath.starts_with("llvm-project/llvm/test")
+                && (spath.ends_with(".ll") || spath.ends_with(".td") || spath.ends_with(".s"))
+            {
+                return false;
+            }
         }
 
         // Cargo tests use some files like `.gitignore` that we would otherwise exclude.
-        const CARGO_TESTS: &[&str] = &["tools/cargo/tests", "tools\\cargo\\tests"];
-        if CARGO_TESTS.iter().any(|path| spath.contains(path)) {
+        if spath.starts_with("tools/cargo/tests") {
             return true;
         }
 
-        let full_path = Path::new(dir).join(path);
-        if exclude_dirs.iter().any(|excl| full_path == Path::new(excl)) {
-            return false;
+        if !exclude_dirs.is_empty() {
+            let full_path = Path::new(dir).join(path);
+            if exclude_dirs.iter().any(|excl| full_path == Path::new(excl)) {
+                return false;
+            }
         }
 
-        let excludes = [
+        static EXCLUDES: &[&str] = &[
             "CVS",
             "RCS",
             "SCCS",
@@ -1011,7 +1006,15 @@ fn copy_src_dirs(
             ".hgrags",
             "_darcs",
         ];
-        !path.iter().map(|s| s.to_str().unwrap()).any(|s| excludes.contains(&s))
+
+        // We want to check if any component of `path` doesn't contain the strings in `EXCLUDES`.
+        // However, since we traverse directories top-down in `Builder::cp_link_filtered`,
+        // it is enough to always check only the last component:
+        // - If the path is a file, we will iterate to it and then check it's filename
+        // - If the path is a dir, if it's dir name contains an excluded string, we will not even
+        //   recurse into it.
+        let last_component = path.iter().next_back().map(|s| s.to_str().unwrap()).unwrap();
+        !EXCLUDES.contains(&last_component)
     }
 
     // Copy the directories using our filter
diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
index 706a3cbb2109b..55e74f9e4d996 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -1862,7 +1862,6 @@ impl Build {
                     self.create_dir(&dst);
                     self.cp_link_filtered_recurse(&path, &dst, &relative, filter);
                 } else {
-                    let _ = fs::remove_file(&dst);
                     self.copy_link(&path, &dst, FileType::Regular);
                 }
             }
diff --git a/src/ci/docker/host-x86_64/tidy/Dockerfile b/src/ci/docker/host-x86_64/tidy/Dockerfile
index ee1ae5410ee81..c8558689d3ba9 100644
--- a/src/ci/docker/host-x86_64/tidy/Dockerfile
+++ b/src/ci/docker/host-x86_64/tidy/Dockerfile
@@ -45,4 +45,4 @@ RUN bash -c 'npm install -g eslint@$(cat /tmp/eslint.version)'
 # NOTE: intentionally uses python2 for x.py so we can test it still works.
 # validate-toolstate only runs in our CI, so it's ok for it to only support python3.
 ENV SCRIPT TIDY_PRINT_DIFF=1 python2.7 ../x.py test --stage 0 \
-  src/tools/tidy tidyselftest --extra-checks=py,cpp,js
+  src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck
diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md
index 07eafdf4c4c62..445b10188e3f8 100644
--- a/src/doc/rustc/src/codegen-options/index.md
+++ b/src/doc/rustc/src/codegen-options/index.md
@@ -375,12 +375,12 @@ linking time. It takes one of the following values:
 
 * `y`, `yes`, `on`, `true`, `fat`, or no value: perform "fat" LTO which attempts to
   perform optimizations across all crates within the dependency graph.
-* `n`, `no`, `off`, `false`: disables LTO.
 * `thin`: perform ["thin"
   LTO](http://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html).
   This is similar to "fat", but takes substantially less time to run while
   still achieving performance gains similar to "fat".
   For larger projects like the Rust compiler, ThinLTO can even result in better performance than fat LTO.
+* `n`, `no`, `off`, `false`: disables LTO.
 
 If `-C lto` is not specified, then the compiler will attempt to perform "thin
 local LTO" which performs "thin" LTO on the local crate only across its
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 26b087feb1684..46aaa0068dee6 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1552,10 +1552,10 @@ impl Type {
         matches!(self, Type::Path { path: Path { res: Res::Def(DefKind::TyAlias, _), .. } })
     }
 
-    /// Check if two types are "the same" for documentation purposes.
+    /// Check if this type is a subtype of another type for documentation purposes.
     ///
     /// This is different from `Eq`, because it knows that things like
-    /// `Placeholder` are possible matches for everything.
+    /// `Infer` and generics have special subtyping rules.
     ///
     /// This relation is not commutative when generics are involved:
     ///
@@ -1566,8 +1566,8 @@ impl Type {
     /// let cache = Cache::new(false);
     /// let generic = Type::Generic(rustc_span::symbol::sym::Any);
     /// let unit = Type::Primitive(PrimitiveType::Unit);
-    /// assert!(!generic.is_same(&unit, &cache));
-    /// assert!(unit.is_same(&generic, &cache));
+    /// assert!(!generic.is_doc_subtype_of(&unit, &cache));
+    /// assert!(unit.is_doc_subtype_of(&generic, &cache));
     /// ```
     ///
     /// An owned type is also the same as its borrowed variants (this is commutative),
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 8e3d07b3a1c28..21d154edf5d2a 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -1529,7 +1529,7 @@ function preLoadCss(cssUrl) {
             ["&#9166;", "Go to active search result"],
             ["+", "Expand all sections"],
             ["-", "Collapse all sections"],
-            // for the sake of brevity, we don't say "inherint impl blocks",
+            // for the sake of brevity, we don't say "inherit impl blocks",
             // although that would be more correct,
             // since trait impl blocks are collapsed by -
             ["_", "Collapse all sections, including impl blocks"],
diff --git a/src/tools/miri/src/shims/foreign_items.rs b/src/tools/miri/src/shims/foreign_items.rs
index 21545b680299c..23b1d0c4f6ecf 100644
--- a/src/tools/miri/src/shims/foreign_items.rs
+++ b/src/tools/miri/src/shims/foreign_items.rs
@@ -146,7 +146,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                         return interp_ok(());
                     }
                     // Skip over items without an explicitly defined symbol name.
-                    if !(attrs.export_name.is_some()
+                    if !(attrs.symbol_name.is_some()
                         || attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE)
                         || attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL))
                     {
diff --git a/src/tools/nix-dev-shell/shell.nix b/src/tools/nix-dev-shell/shell.nix
index 0adbacf7e8d56..ad33b121f979a 100644
--- a/src/tools/nix-dev-shell/shell.nix
+++ b/src/tools/nix-dev-shell/shell.nix
@@ -14,6 +14,7 @@ pkgs.mkShell {
   packages = [
     pkgs.git
     pkgs.nix
+    pkgs.glibc.static
     x
     # Get the runtime deps of the x wrapper
   ] ++ lists.flatten (attrsets.attrValues env);
diff --git a/src/tools/rustdoc-js/tester.js b/src/tools/rustdoc-js/tester.js
index 0baa179e16b2d..b88c95d81bca1 100644
--- a/src/tools/rustdoc-js/tester.js
+++ b/src/tools/rustdoc-js/tester.js
@@ -409,6 +409,24 @@ async function runChecks(testFile, doSearch, parseQuery, getCorrections) {
     return res;
 }
 
+function mostRecentMatch(staticFiles, regex) {
+    const matchingEntries = fs.readdirSync(staticFiles)
+        .filter(f => f.match(regex))
+        .map(f => {
+            const stats = fs.statSync(path.join(staticFiles, f));
+            return {
+                path: f,
+                time: stats.mtimeMs,
+            };
+        });
+    if (matchingEntries.length === 0) {
+        throw "No static file matching regex";
+    }
+    // We sort entries in descending order.
+    matchingEntries.sort((a, b) => b.time - a.time);
+    return matchingEntries[0].path;
+}
+
 /**
  * Load searchNNN.js and search-indexNNN.js.
  *
@@ -452,7 +470,7 @@ function loadSearchJS(doc_folder, resource_suffix) {
     };
 
     const staticFiles = path.join(doc_folder, "static.files");
-    const searchJs = fs.readdirSync(staticFiles).find(f => f.match(/search.*\.js$/));
+    const searchJs = mostRecentMatch(staticFiles, /search-[0-9a-f]{8}.*\.js$/);
     const searchModule = require(path.join(staticFiles, searchJs));
     searchModule.initSearch(searchIndex.searchIndex);
     const docSearch = searchModule.docSearch;
diff --git a/src/tools/tidy/src/extra_checks/mod.rs b/src/tools/tidy/src/extra_checks/mod.rs
index f90f716cd9501..31169ec596775 100644
--- a/src/tools/tidy/src/extra_checks/mod.rs
+++ b/src/tools/tidy/src/extra_checks/mod.rs
@@ -41,7 +41,6 @@ const RUFF_CONFIG_PATH: &[&str] = &["src", "tools", "tidy", "config", "ruff.toml
 const RUFF_CACHE_PATH: &[&str] = &["cache", "ruff_cache"];
 const PIP_REQ_PATH: &[&str] = &["src", "tools", "tidy", "config", "requirements.txt"];
 
-// this must be kept in sync with with .github/workflows/spellcheck.yml
 const SPELLCHECK_DIRS: &[&str] = &["compiler", "library", "src/bootstrap", "src/librustdoc"];
 
 pub fn check(
@@ -51,6 +50,7 @@ pub fn check(
     librustdoc_path: &Path,
     tools_path: &Path,
     npm: &Path,
+    cargo: &Path,
     bless: bool,
     extra_checks: Option<&str>,
     pos_args: &[String],
@@ -63,6 +63,7 @@ pub fn check(
         librustdoc_path,
         tools_path,
         npm,
+        cargo,
         bless,
         extra_checks,
         pos_args,
@@ -78,6 +79,7 @@ fn check_impl(
     librustdoc_path: &Path,
     tools_path: &Path,
     npm: &Path,
+    cargo: &Path,
     bless: bool,
     extra_checks: Option<&str>,
     pos_args: &[String],
@@ -293,7 +295,7 @@ fn check_impl(
         } else {
             eprintln!("spellcheck files");
         }
-        spellcheck_runner(&args)?;
+        spellcheck_runner(root_path, &outdir, &cargo, &args)?;
     }
 
     if js_lint || js_typecheck {
@@ -576,34 +578,25 @@ fn shellcheck_runner(args: &[&OsStr]) -> Result<(), Error> {
     if status.success() { Ok(()) } else { Err(Error::FailedCheck("shellcheck")) }
 }
 
-/// Check that spellchecker is installed then run it at the given path
-fn spellcheck_runner(args: &[&str]) -> Result<(), Error> {
-    // sync version with .github/workflows/spellcheck.yml
-    let expected_version = "typos-cli 1.34.0";
-    match Command::new("typos").arg("--version").output() {
-        Ok(o) => {
-            let stdout = String::from_utf8_lossy(&o.stdout);
-            if stdout.trim() != expected_version {
-                return Err(Error::Version {
-                    program: "typos",
-                    required: expected_version,
-                    installed: stdout.trim().to_string(),
-                });
+/// Ensure that spellchecker is installed then run it at the given path
+fn spellcheck_runner(
+    src_root: &Path,
+    outdir: &Path,
+    cargo: &Path,
+    args: &[&str],
+) -> Result<(), Error> {
+    let bin_path =
+        crate::ensure_version_or_cargo_install(outdir, cargo, "typos-cli", "typos", "1.34.0")?;
+    match Command::new(bin_path).current_dir(src_root).args(args).status() {
+        Ok(status) => {
+            if status.success() {
+                Ok(())
+            } else {
+                Err(Error::FailedCheck("typos"))
             }
         }
-        Err(e) if e.kind() == io::ErrorKind::NotFound => {
-            return Err(Error::MissingReq(
-                "typos",
-                "spellcheck file checks",
-                // sync version with .github/workflows/spellcheck.yml
-                Some("install tool via `cargo install typos-cli@1.34.0`".to_owned()),
-            ));
-        }
-        Err(e) => return Err(e.into()),
+        Err(err) => Err(Error::Generic(format!("failed to run typos tool: {err:?}"))),
     }
-
-    let status = Command::new("typos").args(args).status()?;
-    if status.success() { Ok(()) } else { Err(Error::FailedCheck("typos")) }
 }
 
 /// Check git for tracked files matching an extension
diff --git a/src/tools/tidy/src/lib.rs b/src/tools/tidy/src/lib.rs
index 4ea9d051ddb5e..37713cbf75e9b 100644
--- a/src/tools/tidy/src/lib.rs
+++ b/src/tools/tidy/src/lib.rs
@@ -4,7 +4,9 @@
 //! to be used by tools.
 
 use std::ffi::OsStr;
+use std::path::{Path, PathBuf};
 use std::process::Command;
+use std::{env, io};
 
 use build_helper::ci::CiEnv;
 use build_helper::git::{GitConfig, get_closest_upstream_commit};
@@ -180,6 +182,70 @@ pub fn files_modified(ci_info: &CiInfo, pred: impl Fn(&str) -> bool) -> bool {
     !v.is_empty()
 }
 
+/// If the given executable is installed with the given version, use that,
+/// otherwise install via cargo.
+pub fn ensure_version_or_cargo_install(
+    build_dir: &Path,
+    cargo: &Path,
+    pkg_name: &str,
+    bin_name: &str,
+    version: &str,
+) -> io::Result<PathBuf> {
+    // ignore the process exit code here and instead just let the version number check fail.
+    // we also importantly don't return if the program wasn't installed,
+    // instead we want to continue to the fallback.
+    'ck: {
+        // FIXME: rewrite as if-let chain once this crate is 2024 edition.
+        let Ok(output) = Command::new(bin_name).arg("--version").output() else {
+            break 'ck;
+        };
+        let Ok(s) = str::from_utf8(&output.stdout) else {
+            break 'ck;
+        };
+        let Some(v) = s.trim().split_whitespace().last() else {
+            break 'ck;
+        };
+        if v == version {
+            return Ok(PathBuf::from(bin_name));
+        }
+    }
+
+    let tool_root_dir = build_dir.join("misc-tools");
+    let tool_bin_dir = tool_root_dir.join("bin");
+    eprintln!("building external tool {bin_name} from package {pkg_name}@{version}");
+    // use --force to ensure that if the required version is bumped, we update it.
+    // use --target-dir to ensure we have a build cache so repeated invocations aren't slow.
+    // modify PATH so that cargo doesn't print a warning telling the user to modify the path.
+    let cargo_exit_code = Command::new(cargo)
+        .args(["install", "--locked", "--force", "--quiet"])
+        .arg("--root")
+        .arg(&tool_root_dir)
+        .arg("--target-dir")
+        .arg(tool_root_dir.join("target"))
+        .arg(format!("{pkg_name}@{version}"))
+        .env(
+            "PATH",
+            env::join_paths(
+                env::split_paths(&env::var("PATH").unwrap())
+                    .chain(std::iter::once(tool_bin_dir.clone())),
+            )
+            .expect("build dir contains invalid char"),
+        )
+        .env("RUSTFLAGS", "-Copt-level=0")
+        .spawn()?
+        .wait()?;
+    if !cargo_exit_code.success() {
+        return Err(io::Error::other("cargo install failed"));
+    }
+    let bin_path = tool_bin_dir.join(bin_name);
+    assert!(
+        matches!(bin_path.try_exists(), Ok(true)),
+        "cargo install did not produce the expected binary"
+    );
+    eprintln!("finished building tool {bin_name}");
+    Ok(bin_path)
+}
+
 pub mod alphabetical;
 pub mod bins;
 pub mod debug_artifacts;
diff --git a/src/tools/tidy/src/main.rs b/src/tools/tidy/src/main.rs
index cd2567ddb64bf..bfe30258915ea 100644
--- a/src/tools/tidy/src/main.rs
+++ b/src/tools/tidy/src/main.rs
@@ -184,6 +184,7 @@ fn main() {
             &librustdoc_path,
             &tools_path,
             &npm,
+            &cargo,
             bless,
             extra_checks,
             pos_args
diff --git a/tests/ui/attributes/lint_on_root.rs b/tests/ui/attributes/lint_on_root.rs
index bafdb46883ff5..6cec7508560a5 100644
--- a/tests/ui/attributes/lint_on_root.rs
+++ b/tests/ui/attributes/lint_on_root.rs
@@ -1,7 +1,7 @@
 // NOTE: this used to panic in debug builds (by a sanity assertion)
 // and not emit any lint on release builds. See https://github.com/rust-lang/rust/issues/142891.
 #![inline = ""]
-//~^ ERROR: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]` [ill_formed_attribute_input]
+//~^ ERROR: valid forms for the attribute are `#![inline(always)]`, `#![inline(never)]`, and `#![inline]` [ill_formed_attribute_input]
 //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 //~| ERROR attribute cannot be used on
 
diff --git a/tests/ui/attributes/lint_on_root.stderr b/tests/ui/attributes/lint_on_root.stderr
index 9d8d1495c1bfe..f6eafc33d6986 100644
--- a/tests/ui/attributes/lint_on_root.stderr
+++ b/tests/ui/attributes/lint_on_root.stderr
@@ -6,7 +6,7 @@ LL | #![inline = ""]
    |
    = help: `#[inline]` can only be applied to functions
 
-error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
+error: valid forms for the attribute are `#![inline(always)]`, `#![inline(never)]`, and `#![inline]`
   --> $DIR/lint_on_root.rs:3:1
    |
 LL | #![inline = ""]
@@ -19,7 +19,7 @@ LL | #![inline = ""]
 error: aborting due to 2 previous errors
 
 Future incompatibility report: Future breakage diagnostic:
-error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
+error: valid forms for the attribute are `#![inline(always)]`, `#![inline(never)]`, and `#![inline]`
   --> $DIR/lint_on_root.rs:3:1
    |
 LL | #![inline = ""]
diff --git a/tests/ui/attributes/malformed-reprs.stderr b/tests/ui/attributes/malformed-reprs.stderr
index 43085b9c3415c..3a788999542b4 100644
--- a/tests/ui/attributes/malformed-reprs.stderr
+++ b/tests/ui/attributes/malformed-reprs.stderr
@@ -7,18 +7,14 @@ LL | #![repr]
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
-LL - #![repr]
-LL + #[repr(<integer type>)]
-   |
-LL - #![repr]
-LL + #[repr(C)]
-   |
-LL - #![repr]
-LL + #[repr(Rust)]
-   |
-LL - #![repr]
-LL + #[repr(align(...))]
-   |
+LL | #![repr(<integer type>)]
+   |        ++++++++++++++++
+LL | #![repr(C)]
+   |        +++
+LL | #![repr(Rust)]
+   |        ++++++
+LL | #![repr(align(...))]
+   |        ++++++++++++
    = and 2 other candidates
 
 error[E0589]: invalid `repr(align)` attribute: not a power of two
diff --git a/tests/ui/coverage-attr/name-value.stderr b/tests/ui/coverage-attr/name-value.stderr
index 2dac2401e3cd9..d1527ec810c50 100644
--- a/tests/ui/coverage-attr/name-value.stderr
+++ b/tests/ui/coverage-attr/name-value.stderr
@@ -22,10 +22,10 @@ LL |     #![coverage = "off"]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL -     #![coverage = "off"]
-LL +     #[coverage(off)]
+LL +     #![coverage(off)]
    |
 LL -     #![coverage = "off"]
-LL +     #[coverage(on)]
+LL +     #![coverage(on)]
    |
 
 error[E0539]: malformed `coverage` attribute input
diff --git a/tests/ui/coverage-attr/word-only.stderr b/tests/ui/coverage-attr/word-only.stderr
index e916a817e3678..880ad0809536e 100644
--- a/tests/ui/coverage-attr/word-only.stderr
+++ b/tests/ui/coverage-attr/word-only.stderr
@@ -19,12 +19,10 @@ LL |     #![coverage]
    |
 help: try changing it to one of the following valid forms of the attribute
    |
-LL -     #![coverage]
-LL +     #[coverage(off)]
-   |
-LL -     #![coverage]
-LL +     #[coverage(on)]
-   |
+LL |     #![coverage(off)]
+   |                +++++
+LL |     #![coverage(on)]
+   |                ++++
 
 error[E0539]: malformed `coverage` attribute input
   --> $DIR/word-only.rs:21:1
diff --git a/tests/ui/deprecation/deprecation-sanity.rs b/tests/ui/deprecation/deprecation-sanity.rs
index 9698a37602503..45ee91741e5a1 100644
--- a/tests/ui/deprecation/deprecation-sanity.rs
+++ b/tests/ui/deprecation/deprecation-sanity.rs
@@ -42,4 +42,9 @@ impl Default for X {
     }
 }
 
+unsafe extern "C" {
+    #[deprecated]
+    static FOO: std::ffi::c_int;
+}
+
 fn main() { }
diff --git a/tests/ui/deprecation/deprecation-sanity.stderr b/tests/ui/deprecation/deprecation-sanity.stderr
index 1d44215731df4..57af76d8f2492 100644
--- a/tests/ui/deprecation/deprecation-sanity.stderr
+++ b/tests/ui/deprecation/deprecation-sanity.stderr
@@ -177,7 +177,7 @@ LL | #[deprecated = "hello"]
    | ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
+   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, foreign statics, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
    = note: `#[deny(useless_deprecated)]` on by default
 
 error: aborting due to 10 previous errors
diff --git a/tests/ui/inference/issue-72616.stderr b/tests/ui/inference/issue-72616.stderr
index 31a0586301df2..a271639996fd2 100644
--- a/tests/ui/inference/issue-72616.stderr
+++ b/tests/ui/inference/issue-72616.stderr
@@ -6,14 +6,10 @@ LL |         if String::from("a") == "a".try_into().unwrap() {}
    |                              |
    |                              type must be known at this point
    |
-   = note: cannot satisfy `String: PartialEq<_>`
-   = help: the following types implement trait `PartialEq<Rhs>`:
-             `String` implements `PartialEq<&str>`
-             `String` implements `PartialEq<ByteStr>`
-             `String` implements `PartialEq<ByteString>`
-             `String` implements `PartialEq<Cow<'_, str>>`
-             `String` implements `PartialEq<str>`
-             `String` implements `PartialEq`
+   = note: multiple `impl`s satisfying `String: PartialEq<_>` found in the following crates: `alloc`, `std`:
+           - impl PartialEq for String;
+           - impl PartialEq<Path> for String;
+           - impl PartialEq<PathBuf> for String;
 help: try using a fully qualified path to specify the expected types
    |
 LL -         if String::from("a") == "a".try_into().unwrap() {}
diff --git a/tests/ui/reachable/expr_cast.rs b/tests/ui/reachable/expr_cast.rs
index e8e477ea4f684..aa412c99b2e9b 100644
--- a/tests/ui/reachable/expr_cast.rs
+++ b/tests/ui/reachable/expr_cast.rs
@@ -1,13 +1,21 @@
-#![allow(unused_variables)]
-#![allow(unused_assignments)]
-#![allow(dead_code)]
+//@ check-pass
+//@ edition: 2024
+//
+// Check that we don't warn on `as` casts of never to any as unreachable.
+// While they *are* unreachable, sometimes they are required to appeal typeck.
 #![deny(unreachable_code)]
-#![feature(never_type, type_ascription)]
 
 fn a() {
-    // the cast is unreachable:
-    let x = {return} as !; //~ ERROR unreachable
-    //~| ERROR non-primitive cast
+    _ = {return} as u32;
 }
 
-fn main() { }
+fn b() {
+    (return) as u32;
+}
+
+// example that needs an explicit never-to-any `as` cast
+fn example() -> impl Iterator<Item = u8> {
+    todo!() as std::iter::Empty<_>
+}
+
+fn main() {}
diff --git a/tests/ui/reachable/expr_cast.stderr b/tests/ui/reachable/expr_cast.stderr
deleted file mode 100644
index 6643f1784a174..0000000000000
--- a/tests/ui/reachable/expr_cast.stderr
+++ /dev/null
@@ -1,24 +0,0 @@
-error: unreachable expression
-  --> $DIR/expr_cast.rs:9:13
-   |
-LL |     let x = {return} as !;
-   |             ^------^^^^^^
-   |             ||
-   |             |any code following this expression is unreachable
-   |             unreachable expression
-   |
-note: the lint level is defined here
-  --> $DIR/expr_cast.rs:4:9
-   |
-LL | #![deny(unreachable_code)]
-   |         ^^^^^^^^^^^^^^^^
-
-error[E0605]: non-primitive cast: `()` as `!`
-  --> $DIR/expr_cast.rs:9:13
-   |
-LL |     let x = {return} as !;
-   |             ^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0605`.
diff --git a/tests/ui/reachable/unreachable-try-pattern.rs b/tests/ui/reachable/unreachable-try-pattern.rs
index 22cbfb95af084..1358722e229ce 100644
--- a/tests/ui/reachable/unreachable-try-pattern.rs
+++ b/tests/ui/reachable/unreachable-try-pattern.rs
@@ -18,7 +18,7 @@ fn bar(x: Result<!, i32>) -> Result<u32, i32> {
 fn foo(x: Result<!, i32>) -> Result<u32, i32> {
     let y = (match x { Ok(n) => Ok(n as u32), Err(e) => Err(e) })?;
     //~^ WARN unreachable pattern
-    //~| WARN unreachable expression
+    //~| WARN unreachable call
     Ok(y)
 }
 
diff --git a/tests/ui/reachable/unreachable-try-pattern.stderr b/tests/ui/reachable/unreachable-try-pattern.stderr
index 40b116131057c..468af427249c1 100644
--- a/tests/ui/reachable/unreachable-try-pattern.stderr
+++ b/tests/ui/reachable/unreachable-try-pattern.stderr
@@ -1,11 +1,10 @@
-warning: unreachable expression
-  --> $DIR/unreachable-try-pattern.rs:19:36
+warning: unreachable call
+  --> $DIR/unreachable-try-pattern.rs:19:33
    |
 LL |     let y = (match x { Ok(n) => Ok(n as u32), Err(e) => Err(e) })?;
-   |                                    -^^^^^^^
-   |                                    |
-   |                                    unreachable expression
-   |                                    any code following this expression is unreachable
+   |                                 ^^ - any code following this expression is unreachable
+   |                                 |
+   |                                 unreachable call
    |
 note: the lint level is defined here
   --> $DIR/unreachable-try-pattern.rs:3:9
diff --git a/tests/ui/resolve/path-attr-in-const-block.stderr b/tests/ui/resolve/path-attr-in-const-block.stderr
index f3ae5b60c4fe8..23f4e319c6d4d 100644
--- a/tests/ui/resolve/path-attr-in-const-block.stderr
+++ b/tests/ui/resolve/path-attr-in-const-block.stderr
@@ -11,7 +11,7 @@ LL |         #![path = foo!()]
    |         ^^^^^^^^^^------^
    |         |         |
    |         |         expected a string literal here
-   |         help: must be of the form: `#[path = "file"]`
+   |         help: must be of the form: `#![path = "file"]`
    |
    = note: for more information, visit <https://doc.rust-lang.org/reference/items/modules.html#the-path-attribute>
 
diff --git a/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr
index ebe103ef19a1c..c5984f53f68b5 100644
--- a/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr
+++ b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr
@@ -10,6 +10,8 @@ LL |     String::from("Girls Band Cry") == T(String::from("Girls Band Cry"));
              `String` implements `PartialEq<ByteStr>`
              `String` implements `PartialEq<ByteString>`
              `String` implements `PartialEq<Cow<'_, str>>`
+             `String` implements `PartialEq<Path>`
+             `String` implements `PartialEq<PathBuf>`
              `String` implements `PartialEq<str>`
              `String` implements `PartialEq`
    = note: `T` implements `PartialEq<String>`
diff --git a/tests/ui/where-clauses/unsupported_attribute.stderr b/tests/ui/where-clauses/unsupported_attribute.stderr
index 411c895ed8736..cdd6e82b98d4d 100644
--- a/tests/ui/where-clauses/unsupported_attribute.stderr
+++ b/tests/ui/where-clauses/unsupported_attribute.stderr
@@ -64,7 +64,7 @@ error: `#[deprecated]` attribute cannot be used on where predicates
 LL |     #[deprecated] T: Trait,
    |     ^^^^^^^^^^^^^
    |
-   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
+   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, foreign statics, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
 
 error: `#[deprecated]` attribute cannot be used on where predicates
   --> $DIR/unsupported_attribute.rs:25:5
@@ -72,7 +72,7 @@ error: `#[deprecated]` attribute cannot be used on where predicates
 LL |     #[deprecated] 'a: 'static,
    |     ^^^^^^^^^^^^^
    |
-   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
+   = help: `#[deprecated]` can be applied to functions, data types, modules, unions, constants, statics, macro defs, type aliases, use statements, foreign statics, struct fields, traits, associated types, associated consts, enum variants, inherent impl blocks, crates
 
 error: `#[automatically_derived]` attribute cannot be used on where predicates
   --> $DIR/unsupported_attribute.rs:26:5
diff --git a/triagebot.toml b/triagebot.toml
index 2f31a30019bce..e55f2abce7f10 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -1003,11 +1003,12 @@ cc = ["@calebzulawski", "@programmerjake"]
 
 [mentions."library/core/src/unicode/unicode_data.rs"]
 message = """
-`library/core/src/unicode/unicode_data.rs` is generated by
-`src/tools/unicode-table-generator` via `./x run
-src/tools/unicode-table-generator`. If you want to modify `unicode_data.rs`,
-please modify the tool then regenerate the library source file with the tool
-instead of editing the library source file manually.
+`library/core/src/unicode/unicode_data.rs` is generated by the \
+`src/tools/unicode-table-generator` tool.
+
+If you want to modify `unicode_data.rs`, please modify the tool then regenerate the library \
+source file via `./x run src/tools/unicode-table-generator` instead of editing \
+`unicode_data.rs` manually.
 """
 
 [mentions."src/librustdoc/html/static"]
diff --git a/typos.toml b/typos.toml
index 317aafc861565..b0ff48f8fa28b 100644
--- a/typos.toml
+++ b/typos.toml
@@ -33,6 +33,7 @@ misformed = "misformed"
 targetting = "targetting"
 publically = "publically"
 clonable = "clonable"
+moreso = "moreso"
 
 # this can be valid word, depends on dictionary edition
 #matcheable = "matcheable"