Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

19 files changed, 1659 insertions, 1063 deletions

diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index b3f15ba7c..27a57adf9 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -4,16 +4,21 @@
 //! conflicts between multiple such attributes attached to the same
 //! item.
 
-use crate::errors;
+use crate::errors::{
+    self, AttrApplication, DebugVisualizerUnreadable, InvalidAttrAtCrateLevel, ObjectLifetimeErr,
+    OnlyHasEffectOn, TransparentIncompatible, UnrecognizedReprHint,
+};
 use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_errors::{fluent, struct_span_err, Applicability, MultiSpan};
+use rustc_errors::{fluent, Applicability, MultiSpan};
 use rustc_expand::base::resolve_path;
 use rustc_feature::{AttributeDuplicates, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_hir as hir;
-use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID};
+use rustc_hir::{
+    self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID, CRATE_OWNER_ID,
+};
 use rustc_hir::{MethodKind, Target};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
@@ -35,8 +40,8 @@ pub(crate) fn target_from_impl_item<'tcx>(
     match impl_item.kind {
         hir::ImplItemKind::Const(..) => Target::AssocConst,
         hir::ImplItemKind::Fn(..) => {
-            let parent_hir_id = tcx.hir().get_parent_item(impl_item.hir_id());
-            let containing_item = tcx.hir().expect_item(parent_hir_id);
+            let parent_def_id = tcx.hir().get_parent_item(impl_item.hir_id()).def_id;
+            let containing_item = tcx.hir().expect_item(parent_def_id);
             let containing_impl_is_for_trait = match &containing_item.kind {
                 hir::ItemKind::Impl(impl_) => impl_.of_trait.is_some(),
                 _ => bug!("parent of an ImplItem must be an Impl"),
@@ -47,7 +52,7 @@ pub(crate) fn target_from_impl_item<'tcx>(
                 Target::Method(MethodKind::Inherent)
             }
         }
-        hir::ImplItemKind::TyAlias(..) => Target::AssocTy,
+        hir::ImplItemKind::Type(..) => Target::AssocTy,
     }
 }
 
@@ -162,17 +167,17 @@ impl CheckAttrVisitor<'_> {
                 sym::no_mangle => self.check_no_mangle(hir_id, attr, span, target),
                 sym::deprecated => self.check_deprecated(hir_id, attr, span, target),
                 sym::macro_use | sym::macro_escape => self.check_macro_use(hir_id, attr, target),
-                sym::path => self.check_generic_attr(hir_id, attr, target, &[Target::Mod]),
+                sym::path => self.check_generic_attr(hir_id, attr, target, Target::Mod),
                 sym::plugin_registrar => self.check_plugin_registrar(hir_id, attr, target),
                 sym::macro_export => self.check_macro_export(hir_id, attr, target),
                 sym::ignore | sym::should_panic | sym::proc_macro_derive => {
-                    self.check_generic_attr(hir_id, attr, target, &[Target::Fn])
+                    self.check_generic_attr(hir_id, attr, target, Target::Fn)
                 }
                 sym::automatically_derived => {
-                    self.check_generic_attr(hir_id, attr, target, &[Target::Impl])
+                    self.check_generic_attr(hir_id, attr, target, Target::Impl)
                 }
                 sym::no_implicit_prelude => {
-                    self.check_generic_attr(hir_id, attr, target, &[Target::Mod])
+                    self.check_generic_attr(hir_id, attr, target, Target::Mod)
                 }
                 sym::rustc_object_lifetime_default => self.check_object_lifetime_default(hir_id),
                 _ => {}
@@ -263,7 +268,7 @@ impl CheckAttrVisitor<'_> {
             }
             // FIXME(#65833): We permit associated consts to have an `#[inline]` attribute with
             // just a lint, because we previously erroneously allowed it and some crates used it
-            // accidentally, to to be compatible with crates depending on them, we can't throw an
+            // accidentally, to be compatible with crates depending on them, we can't throw an
             // error here.
             Target::AssocConst => {
                 self.tcx.emit_spanned_lint(
@@ -349,29 +354,18 @@ impl CheckAttrVisitor<'_> {
         hir_id: HirId,
         attr: &Attribute,
         target: Target,
-        allowed_targets: &[Target],
+        allowed_target: Target,
     ) {
-        if !allowed_targets.iter().any(|t| t == &target) {
-            let name = attr.name_or_empty();
-            let mut i = allowed_targets.iter();
-            // Pluralize
-            let b = i.next().map_or_else(String::new, |t| t.to_string() + "s");
-            let supported_names = i.enumerate().fold(b, |mut b, (i, allowed_target)| {
-                if allowed_targets.len() > 2 && i == allowed_targets.len() - 2 {
-                    b.push_str(", and ");
-                } else if allowed_targets.len() == 2 && i == allowed_targets.len() - 2 {
-                    b.push_str(" and ");
-                } else {
-                    b.push_str(", ");
-                }
-                // Pluralize
-                b.push_str(&(allowed_target.to_string() + "s"));
-                b
-            });
-            self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
-                lint.build(&format!("`#[{name}]` only has an effect on {}", supported_names))
-                    .emit();
-            });
+        if target != allowed_target {
+            self.tcx.emit_spanned_lint(
+                UNUSED_ATTRIBUTES,
+                hir_id,
+                attr.span,
+                OnlyHasEffectOn {
+                    attr_name: attr.name_or_empty(),
+                    target_name: allowed_target.name().replace(" ", "_"),
+                },
+            );
         }
     }
 
@@ -382,7 +376,7 @@ impl CheckAttrVisitor<'_> {
             | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[allow_internal_unstable]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "naked");
@@ -427,7 +421,7 @@ impl CheckAttrVisitor<'_> {
                     ObjectLifetimeDefault::Param(def_id) => tcx.item_name(def_id).to_string(),
                     ObjectLifetimeDefault::Ambiguous => "Ambiguous".to_owned(),
                 };
-                tcx.sess.span_err(p.span, &repr);
+                tcx.sess.emit_err(ObjectLifetimeErr { span: p.span, repr });
             }
         }
     }
@@ -462,7 +456,7 @@ impl CheckAttrVisitor<'_> {
             Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[track_caller]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 for attr in attrs {
@@ -491,7 +485,7 @@ impl CheckAttrVisitor<'_> {
             Target::Struct | Target::Enum | Target::Variant => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[non_exhaustive]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "non_exhaustive");
@@ -513,7 +507,7 @@ impl CheckAttrVisitor<'_> {
             Target::Trait => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[marker]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "marker");
@@ -572,7 +566,7 @@ impl CheckAttrVisitor<'_> {
             }
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[target_feature]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "target_feature");
@@ -640,8 +634,8 @@ impl CheckAttrVisitor<'_> {
         let span = meta.span();
         if let Some(location) = match target {
             Target::AssocTy => {
-                let parent_hir_id = self.tcx.hir().get_parent_item(hir_id);
-                let containing_item = self.tcx.hir().expect_item(parent_hir_id);
+                let parent_def_id = self.tcx.hir().get_parent_item(hir_id).def_id;
+                let containing_item = self.tcx.hir().expect_item(parent_def_id);
                 if Target::from_item(containing_item) == Target::Impl {
                     Some("type alias in implementation block")
                 } else {
@@ -649,8 +643,8 @@ impl CheckAttrVisitor<'_> {
                 }
             }
             Target::AssocConst => {
-                let parent_hir_id = self.tcx.hir().get_parent_item(hir_id);
-                let containing_item = self.tcx.hir().expect_item(parent_hir_id);
+                let parent_def_id = self.tcx.hir().get_parent_item(hir_id).def_id;
+                let containing_item = self.tcx.hir().expect_item(parent_def_id);
                 // We can't link to trait impl's consts.
                 let err = "associated constant in trait implementation block";
                 match containing_item.kind {
@@ -828,8 +822,8 @@ impl CheckAttrVisitor<'_> {
             if let Some((prev_inline, prev_span)) = *specified_inline {
                 if do_inline != prev_inline {
                     let mut spans = MultiSpan::from_spans(vec![prev_span, meta.span()]);
-                    spans.push_span_label(prev_span, fluent::passes::doc_inline_conflict_first);
-                    spans.push_span_label(meta.span(), fluent::passes::doc_inline_conflict_second);
+                    spans.push_span_label(prev_span, fluent::passes_doc_inline_conflict_first);
+                    spans.push_span_label(meta.span(), fluent::passes_doc_inline_conflict_second);
                     self.tcx.sess.emit_err(errors::DocKeywordConflict { spans });
                     return false;
                 }
@@ -875,25 +869,31 @@ impl CheckAttrVisitor<'_> {
         hir_id: HirId,
     ) -> bool {
         if hir_id != CRATE_HIR_ID {
-            self.tcx.struct_span_lint_hir(INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), |lint| {
-                let mut err = lint.build(fluent::passes::attr_crate_level);
-                if attr.style == AttrStyle::Outer
-                    && self.tcx.hir().get_parent_item(hir_id) == CRATE_DEF_ID
-                {
-                    if let Ok(mut src) = self.tcx.sess.source_map().span_to_snippet(attr.span) {
-                        src.insert(1, '!');
-                        err.span_suggestion_verbose(
-                            attr.span,
-                            fluent::passes::suggestion,
-                            src,
-                            Applicability::MaybeIncorrect,
-                        );
-                    } else {
-                        err.span_help(attr.span, fluent::passes::help);
+            self.tcx.struct_span_lint_hir(
+                INVALID_DOC_ATTRIBUTES,
+                hir_id,
+                meta.span(),
+                fluent::passes_attr_crate_level,
+                |err| {
+                    if attr.style == AttrStyle::Outer
+                        && self.tcx.hir().get_parent_item(hir_id) == CRATE_OWNER_ID
+                    {
+                        if let Ok(mut src) = self.tcx.sess.source_map().span_to_snippet(attr.span) {
+                            src.insert(1, '!');
+                            err.span_suggestion_verbose(
+                                attr.span,
+                                fluent::suggestion,
+                                src,
+                                Applicability::MaybeIncorrect,
+                            );
+                        } else {
+                            err.span_help(attr.span, fluent::help);
+                        }
                     }
-                }
-                err.note(fluent::passes::note).emit();
-            });
+                    err.note(fluent::note);
+                    err
+                },
+            );
             return false;
         }
         true
@@ -934,6 +934,22 @@ impl CheckAttrVisitor<'_> {
         is_valid
     }
 
+    /// Check that the `#![doc(cfg_hide(...))]` attribute only contains a list of attributes.
+    /// Returns `true` if valid.
+    fn check_doc_cfg_hide(&self, meta: &NestedMetaItem, hir_id: HirId) -> bool {
+        if meta.meta_item_list().is_some() {
+            true
+        } else {
+            self.tcx.emit_spanned_lint(
+                INVALID_DOC_ATTRIBUTES,
+                hir_id,
+                meta.span(),
+                errors::DocCfgHideTakesList,
+            );
+            false
+        }
+    }
+
     /// Runs various checks on `#[doc]` attributes. Returns `true` if valid.
     ///
     /// `specified_inline` should be initialized to `None` and kept for the scope
@@ -987,6 +1003,13 @@ impl CheckAttrVisitor<'_> {
                             is_valid = false;
                         }
 
+                        sym::cfg_hide
+                            if !self.check_attr_crate_level(attr, meta, hir_id)
+                                || !self.check_doc_cfg_hide(meta, hir_id) =>
+                        {
+                            is_valid = false;
+                        }
+
                         sym::inline | sym::no_inline
                             if !self.check_doc_inline(
                                 attr,
@@ -1205,7 +1228,7 @@ impl CheckAttrVisitor<'_> {
             Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {}
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[cold]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "cold");
@@ -1247,7 +1270,7 @@ impl CheckAttrVisitor<'_> {
             Target::ForeignFn | Target::ForeignStatic => {}
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[link_name]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_name");
@@ -1281,7 +1304,7 @@ impl CheckAttrVisitor<'_> {
             Target::ExternCrate => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[no_link]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_link");
@@ -1311,7 +1334,7 @@ impl CheckAttrVisitor<'_> {
             Target::Method(..) if self.is_impl_item(hir_id) => true,
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[export_name]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "export_name");
@@ -1503,7 +1526,7 @@ impl CheckAttrVisitor<'_> {
             Target::Static | Target::Fn | Target::Method(..) => {}
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[link_section]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_section");
@@ -1528,7 +1551,7 @@ impl CheckAttrVisitor<'_> {
             Target::Method(..) if self.is_impl_item(hir_id) => {}
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[no_mangle]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_mangle");
@@ -1594,12 +1617,17 @@ impl CheckAttrVisitor<'_> {
                 continue;
             }
 
-            let (article, allowed_targets) = match hint.name_or_empty() {
+            match hint.name_or_empty() {
                 sym::C => {
                     is_c = true;
                     match target {
                         Target::Struct | Target::Union | Target::Enum => continue,
-                        _ => ("a", "struct, enum, or union"),
+                        _ => {
+                            self.tcx.sess.emit_err(AttrApplication::StructEnumUnion {
+                                hint_span: hint.span(),
+                                span,
+                            });
+                        }
                     }
                 }
                 sym::align => {
@@ -1615,12 +1643,20 @@ impl CheckAttrVisitor<'_> {
 
                     match target {
                         Target::Struct | Target::Union | Target::Enum | Target::Fn => continue,
-                        _ => ("a", "struct, enum, function, or union"),
+                        _ => {
+                            self.tcx.sess.emit_err(AttrApplication::StructEnumFunctionUnion {
+                                hint_span: hint.span(),
+                                span,
+                            });
+                        }
                     }
                 }
                 sym::packed => {
                     if target != Target::Struct && target != Target::Union {
-                        ("a", "struct or union")
+                        self.tcx.sess.emit_err(AttrApplication::StructUnion {
+                            hint_span: hint.span(),
+                            span,
+                        });
                     } else {
                         continue;
                     }
@@ -1628,7 +1664,9 @@ impl CheckAttrVisitor<'_> {
                 sym::simd => {
                     is_simd = true;
                     if target != Target::Struct {
-                        ("a", "struct")
+                        self.tcx
+                            .sess
+                            .emit_err(AttrApplication::Struct { hint_span: hint.span(), span });
                     } else {
                         continue;
                     }
@@ -1637,7 +1675,12 @@ impl CheckAttrVisitor<'_> {
                     is_transparent = true;
                     match target {
                         Target::Struct | Target::Union | Target::Enum => continue,
-                        _ => ("a", "struct, enum, or union"),
+                        _ => {
+                            self.tcx.sess.emit_err(AttrApplication::StructEnumUnion {
+                                hint_span: hint.span(),
+                                span,
+                            });
+                        }
                     }
                 }
                 sym::i8
@@ -1654,35 +1697,18 @@ impl CheckAttrVisitor<'_> {
                 | sym::usize => {
                     int_reprs += 1;
                     if target != Target::Enum {
-                        ("an", "enum")
+                        self.tcx
+                            .sess
+                            .emit_err(AttrApplication::Enum { hint_span: hint.span(), span });
                     } else {
                         continue;
                     }
                 }
                 _ => {
-                    struct_span_err!(
-                        self.tcx.sess,
-                        hint.span(),
-                        E0552,
-                        "unrecognized representation hint"
-                    )
-                    .help("valid reprs are `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, \
-                          `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`")
-                    .emit();
-
+                    self.tcx.sess.emit_err(UnrecognizedReprHint { span: hint.span() });
                     continue;
                 }
             };
-
-            struct_span_err!(
-                self.tcx.sess,
-                hint.span(),
-                E0517,
-                "{}",
-                &format!("attribute should be applied to {article} {allowed_targets}")
-            )
-            .span_label(span, &format!("not {article} {allowed_targets}"))
-            .emit();
         }
 
         // Just point at all repr hints if there are any incompatibilities.
@@ -1692,14 +1718,9 @@ impl CheckAttrVisitor<'_> {
         // Error on repr(transparent, <anything else>).
         if is_transparent && hints.len() > 1 {
             let hint_spans: Vec<_> = hint_spans.clone().collect();
-            struct_span_err!(
-                self.tcx.sess,
-                hint_spans,
-                E0692,
-                "transparent {} cannot have other repr hints",
-                target
-            )
-            .emit();
+            self.tcx
+                .sess
+                .emit_err(TransparentIncompatible { hint_spans, target: target.to_string() });
         }
         // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8)
         if (int_reprs > 1)
@@ -1742,7 +1763,7 @@ impl CheckAttrVisitor<'_> {
                     }
                 }
                 Some(_) => {
-                    // This error case is handled in rustc_typeck::collect.
+                    // This error case is handled in rustc_hir_analysis::collect.
                 }
                 None => {
                     // Default case (compiler) when arg isn't defined.
@@ -1784,7 +1805,7 @@ impl CheckAttrVisitor<'_> {
             Target::MacroDef => true,
             // FIXME(#80564): We permit struct fields and match arms to have an
             // `#[allow_internal_unstable]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm => {
                 self.inline_attr_str_error_without_macro_def(
@@ -1851,14 +1872,12 @@ impl CheckAttrVisitor<'_> {
 
         match std::fs::File::open(&file) {
             Ok(_) => true,
-            Err(err) => {
-                self.tcx
-                    .sess
-                    .struct_span_err(
-                        meta_item.span,
-                        &format!("couldn't read {}: {}", file.display(), err),
-                    )
-                    .emit();
+            Err(error) => {
+                self.tcx.sess.emit_err(DebugVisualizerUnreadable {
+                    span: meta_item.span,
+                    file: &file,
+                    error,
+                });
                 false
             }
         }
@@ -1881,7 +1900,7 @@ impl CheckAttrVisitor<'_> {
             }
             // FIXME(#80564): We permit struct fields and match arms to have an
             // `#[allow_internal_unstable]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to to be compatible
+            // erroneously allowed it and some crates used it accidentally, to be compatible
             // with crates depending on them, we can't throw an error here.
             Target::Field | Target::Arm | Target::MacroDef => {
                 self.inline_attr_str_error_with_macro_def(hir_id, attr, "allow_internal_unstable");
@@ -2043,7 +2062,7 @@ impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         // so this lets us continue to run them while maintaining backwards compatibility.
         // In the long run, the checks should be harmonized.
         if let ItemKind::Macro(ref macro_def, _) = item.kind {
-            let def_id = item.def_id.to_def_id();
+            let def_id = item.owner_id.to_def_id();
             if macro_def.macro_rules && !self.tcx.has_attr(def_id, sym::macro_export) {
                 check_non_exported_macro_for_invalid_attrs(self.tcx, item);
             }
@@ -2169,25 +2188,11 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
         if attr.style == AttrStyle::Inner {
             for attr_to_check in ATTRS_TO_CHECK {
                 if attr.has_name(*attr_to_check) {
-                    let mut err = tcx.sess.struct_span_err(
-                        attr.span,
-                        &format!(
-                            "`{}` attribute cannot be used at crate level",
-                            attr_to_check.to_ident_string()
-                        ),
-                    );
-                    // Only emit an error with a suggestion if we can create a
-                    // string out of the attribute span
-                    if let Ok(src) = tcx.sess.source_map().span_to_snippet(attr.span) {
-                        let replacement = src.replace("#!", "#");
-                        err.span_suggestion_verbose(
-                            attr.span,
-                            "perhaps you meant to use an outer attribute",
-                            replacement,
-                            rustc_errors::Applicability::MachineApplicable,
-                        );
-                    }
-                    err.emit();
+                    tcx.sess.emit_err(InvalidAttrAtCrateLevel {
+                        span: attr.span,
+                        snippet: tcx.sess.source_map().span_to_snippet(attr.span).ok(),
+                        name: *attr_to_check,
+                    });
                 }
             }
         }
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index 70518284c..aa726d6cd 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -8,7 +8,6 @@
 //! through, but errors for structured control flow in a `const` should be emitted here.
 
 use rustc_attr as attr;
-use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
@@ -18,6 +17,8 @@ use rustc_middle::ty::TyCtxt;
 use rustc_session::parse::feature_err;
 use rustc_span::{sym, Span, Symbol};
 
+use crate::errors::ExprNotAllowedInContext;
+
 /// An expression that is not *always* legal in a const context.
 #[derive(Clone, Copy)]
 enum NonConstExpr {
@@ -133,18 +134,22 @@ impl<'tcx> CheckConstVisitor<'tcx> {
         let const_kind =
             const_kind.expect("`const_check_violated` may only be called inside a const context");
 
-        let msg = format!("{} is not allowed in a `{}`", expr.name(), const_kind.keyword_name());
-
         let required_gates = required_gates.unwrap_or(&[]);
         let missing_gates: Vec<_> =
             required_gates.iter().copied().filter(|&g| !features.enabled(g)).collect();
 
         match missing_gates.as_slice() {
             [] => {
-                struct_span_err!(tcx.sess, span, E0744, "{}", msg).emit();
+                tcx.sess.emit_err(ExprNotAllowedInContext {
+                    span,
+                    expr: expr.name(),
+                    context: const_kind.keyword_name(),
+                });
             }
 
             [missing_primary, ref missing_secondary @ ..] => {
+                let msg =
+                    format!("{} is not allowed in a `{}`", expr.name(), const_kind.keyword_name());
                 let mut err = feature_err(&tcx.sess.parse_sess, *missing_primary, span, &msg);
 
                 // If multiple feature gates would be required to enable this expression, include
@@ -191,10 +196,6 @@ impl<'tcx> Visitor<'tcx> for CheckConstVisitor<'tcx> {
         self.tcx.hir()
     }
 
-    fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
-        intravisit::walk_item(self, item);
-    }
-
     fn visit_anon_const(&mut self, anon: &'tcx hir::AnonConst) {
         let kind = Some(hir::ConstContext::Const);
         self.recurse_into(kind, None, |this| intravisit::walk_anon_const(this, anon));
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index f141d7bee..753d01f46 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -11,13 +11,15 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Node, PatKind, TyKind};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use rustc_middle::middle::privacy;
+use rustc_middle::middle::privacy::Level;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
 use rustc_session::lint;
 use rustc_span::symbol::{sym, Symbol};
 use std::mem;
 
+use crate::errors::UselessAssignment;
+
 // Any local node that may call something in its body block should be
 // explored. For example, if it's a live Node::Item that is a
 // function, then we should explore its block to check for codes that
@@ -102,14 +104,8 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 }
             }
             Res::Def(_, def_id) => self.check_def_id(def_id),
-            Res::SelfTy { trait_: t, alias_to: i } => {
-                if let Some(t) = t {
-                    self.check_def_id(t);
-                }
-                if let Some((i, _)) = i {
-                    self.check_def_id(i);
-                }
-            }
+            Res::SelfTyParam { trait_: t } => self.check_def_id(t),
+            Res::SelfTyAlias { alias_to: i, .. } => self.check_def_id(i),
             Res::ToolMod | Res::NonMacroAttr(..) | Res::Err => {}
         }
     }
@@ -186,18 +182,11 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 && !assign.span.from_expansion()
         {
                 let is_field_assign = matches!(lhs.kind, hir::ExprKind::Field(..));
-                self.tcx.struct_span_lint_hir(
+                self.tcx.emit_spanned_lint(
                     lint::builtin::DEAD_CODE,
                     assign.hir_id,
                     assign.span,
-                    |lint| {
-                        lint.build(&format!(
-                            "useless assignment of {} of type `{}` to itself",
-                            if is_field_assign { "field" } else { "variable" },
-                            self.typeck_results().expr_ty(lhs),
-                        ))
-                        .emit();
-                    },
+                    UselessAssignment { is_field_assign, ty: self.typeck_results().expr_ty(lhs) }
                 )
         }
     }
@@ -291,8 +280,8 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
     }
 
     fn visit_node(&mut self, node: Node<'tcx>) {
-        if let Node::ImplItem(hir::ImplItem { def_id, .. }) = node
-            && self.should_ignore_item(def_id.to_def_id())
+        if let Node::ImplItem(hir::ImplItem { owner_id, .. }) = node
+            && self.should_ignore_item(owner_id.to_def_id())
         {
             return;
         }
@@ -304,7 +293,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         match node {
             Node::Item(item) => match item.kind {
                 hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
-                    let def = self.tcx.adt_def(item.def_id);
+                    let def = self.tcx.adt_def(item.owner_id);
                     self.repr_has_repr_c = def.repr().c();
                     self.repr_has_repr_simd = def.repr().simd();
 
@@ -317,7 +306,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 intravisit::walk_trait_item(self, trait_item);
             }
             Node::ImplItem(impl_item) => {
-                let item = self.tcx.local_parent(impl_item.def_id);
+                let item = self.tcx.local_parent(impl_item.owner_id.def_id);
                 if self.tcx.impl_trait_ref(item).is_none() {
                     //// If it's a type whose items are live, then it's live, too.
                     //// This is done to handle the case where, for example, the static
@@ -374,7 +363,7 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
             if has_repr_c || (f.is_positional() && has_repr_simd) {
                 return Some(def_id);
             }
-            if !tcx.visibility(f.hir_id.owner).is_public() {
+            if !tcx.visibility(f.hir_id.owner.def_id).is_public() {
                 return None;
             }
             if tcx.visibility(def_id).is_public() { Some(def_id) } else { None }
@@ -528,10 +517,10 @@ fn check_item<'tcx>(
 ) {
     let allow_dead_code = has_allow_dead_code_or_lang_attr(tcx, id.hir_id());
     if allow_dead_code {
-        worklist.push(id.def_id);
+        worklist.push(id.owner_id.def_id);
     }
 
-    match tcx.def_kind(id.def_id) {
+    match tcx.def_kind(id.owner_id) {
         DefKind::Enum => {
             let item = tcx.hir().item(id);
             if let hir::ItemKind::Enum(ref enum_def, _) = item.kind {
@@ -551,15 +540,15 @@ fn check_item<'tcx>(
             }
         }
         DefKind::Impl => {
-            let of_trait = tcx.impl_trait_ref(id.def_id);
+            let of_trait = tcx.impl_trait_ref(id.owner_id);
 
             if of_trait.is_some() {
-                worklist.push(id.def_id);
+                worklist.push(id.owner_id.def_id);
             }
 
             // get DefIds from another query
             let local_def_ids = tcx
-                .associated_item_def_ids(id.def_id)
+                .associated_item_def_ids(id.owner_id)
                 .iter()
                 .filter_map(|def_id| def_id.as_local());
 
@@ -577,12 +566,12 @@ fn check_item<'tcx>(
             if let hir::ItemKind::Struct(ref variant_data, _) = item.kind
                 && let Some(ctor_hir_id) = variant_data.ctor_hir_id()
             {
-                struct_constructors.insert(tcx.hir().local_def_id(ctor_hir_id), item.def_id);
+                struct_constructors.insert(tcx.hir().local_def_id(ctor_hir_id), item.owner_id.def_id);
             }
         }
         DefKind::GlobalAsm => {
             // global_asm! is always live.
-            worklist.push(id.def_id);
+            worklist.push(id.owner_id.def_id);
         }
         _ => {}
     }
@@ -590,12 +579,12 @@ fn check_item<'tcx>(
 
 fn check_trait_item<'tcx>(tcx: TyCtxt<'tcx>, worklist: &mut Vec<LocalDefId>, id: hir::TraitItemId) {
     use hir::TraitItemKind::{Const, Fn};
-    if matches!(tcx.def_kind(id.def_id), DefKind::AssocConst | DefKind::AssocFn) {
+    if matches!(tcx.def_kind(id.owner_id), DefKind::AssocConst | DefKind::AssocFn) {
         let trait_item = tcx.hir().trait_item(id);
         if matches!(trait_item.kind, Const(_, Some(_)) | Fn(_, hir::TraitFn::Provided(_)))
             && has_allow_dead_code_or_lang_attr(tcx, trait_item.hir_id())
         {
-            worklist.push(trait_item.def_id);
+            worklist.push(trait_item.owner_id.def_id);
         }
     }
 }
@@ -605,27 +594,24 @@ fn check_foreign_item<'tcx>(
     worklist: &mut Vec<LocalDefId>,
     id: hir::ForeignItemId,
 ) {
-    if matches!(tcx.def_kind(id.def_id), DefKind::Static(_) | DefKind::Fn)
+    if matches!(tcx.def_kind(id.owner_id), DefKind::Static(_) | DefKind::Fn)
         && has_allow_dead_code_or_lang_attr(tcx, id.hir_id())
     {
-        worklist.push(id.def_id);
+        worklist.push(id.owner_id.def_id);
     }
 }
 
 fn create_and_seed_worklist<'tcx>(
     tcx: TyCtxt<'tcx>,
 ) -> (Vec<LocalDefId>, FxHashMap<LocalDefId, LocalDefId>) {
-    let access_levels = &tcx.privacy_access_levels(());
+    let effective_visibilities = &tcx.effective_visibilities(());
     // see `MarkSymbolVisitor::struct_constructors`
     let mut struct_constructors = Default::default();
-    let mut worklist = access_levels
-        .map
+    let mut worklist = effective_visibilities
         .iter()
-        .filter_map(
-            |(&id, &level)| {
-                if level >= privacy::AccessLevel::Reachable { Some(id) } else { None }
-            },
-        )
+        .filter_map(|(&id, effective_vis)| {
+            effective_vis.is_public_at_level(Level::Reachable).then_some(id)
+        })
         // Seed entry point
         .chain(tcx.entry_fn(()).and_then(|(def_id, _)| def_id.as_local()))
         .collect::<Vec<_>>();
@@ -726,6 +712,26 @@ impl<'tcx> DeadVisitor<'tcx> {
                 })
                 .collect();
 
+            let descr = tcx.def_kind(first_id).descr(first_id.to_def_id());
+            let span_len = dead_codes.len();
+            let names = match &names[..] {
+                _ if span_len > 6 => String::new(),
+                [name] => format!("`{name}` "),
+                [names @ .., last] => {
+                    format!(
+                        "{} and `{last}` ",
+                        names.iter().map(|name| format!("`{name}`")).join(", ")
+                    )
+                }
+                [] => unreachable!(),
+            };
+            let msg = format!(
+                "{these}{descr}{s} {names}{are} never {participle}",
+                these = if span_len > 6 { "multiple " } else { "" },
+                s = pluralize!(span_len),
+                are = pluralize!("is", span_len),
+            );
+
             tcx.struct_span_lint_hir(
                 if is_positional {
                     lint::builtin::UNUSED_TUPLE_STRUCT_FIELDS
@@ -734,27 +740,8 @@ impl<'tcx> DeadVisitor<'tcx> {
                 },
                 tcx.hir().local_def_id_to_hir_id(first_id),
                 MultiSpan::from_spans(spans.clone()),
-                |lint| {
-                    let descr = tcx.def_kind(first_id).descr(first_id.to_def_id());
-                    let span_len = dead_codes.len();
-                    let names = match &names[..] {
-                        _ if span_len > 6 => String::new(),
-                        [name] => format!("`{name}` "),
-                        [names @ .., last] => {
-                            format!(
-                                "{} and `{last}` ",
-                                names.iter().map(|name| format!("`{name}`")).join(", ")
-                            )
-                        }
-                        [] => unreachable!(),
-                    };
-                    let mut err = lint.build(&format!(
-                        "{these}{descr}{s} {names}{are} never {participle}",
-                        these = if span_len > 6 { "multiple " } else { "" },
-                        s = pluralize!(span_len),
-                        are = pluralize!("is", span_len),
-                    ));
-
+                msg,
+                |err| {
                     if is_positional {
                         err.multipart_suggestion(
                             &format!(
@@ -800,7 +787,7 @@ impl<'tcx> DeadVisitor<'tcx> {
                         );
                         err.note(&msg);
                     }
-                    err.emit();
+                    err
                 },
             );
         }
@@ -874,19 +861,19 @@ fn check_mod_deathness(tcx: TyCtxt<'_>, module: LocalDefId) {
     let module_items = tcx.hir_module_items(module);
 
     for item in module_items.items() {
-        if !live_symbols.contains(&item.def_id) {
-            let parent = tcx.local_parent(item.def_id);
+        if !live_symbols.contains(&item.owner_id.def_id) {
+            let parent = tcx.local_parent(item.owner_id.def_id);
             if parent != module && !live_symbols.contains(&parent) {
                 // We already have diagnosed something.
                 continue;
             }
-            visitor.check_definition(item.def_id);
+            visitor.check_definition(item.owner_id.def_id);
             continue;
         }
 
-        let def_kind = tcx.def_kind(item.def_id);
+        let def_kind = tcx.def_kind(item.owner_id);
         if let DefKind::Struct | DefKind::Union | DefKind::Enum = def_kind {
-            let adt = tcx.adt_def(item.def_id);
+            let adt = tcx.adt_def(item.owner_id);
             let mut dead_variants = Vec::new();
 
             for variant in adt.variants() {
@@ -929,16 +916,21 @@ fn check_mod_deathness(tcx: TyCtxt<'_>, module: LocalDefId) {
                 visitor.warn_dead_fields_and_variants(def_id, "read", dead_fields, is_positional)
             }
 
-            visitor.warn_dead_fields_and_variants(item.def_id, "constructed", dead_variants, false);
+            visitor.warn_dead_fields_and_variants(
+                item.owner_id.def_id,
+                "constructed",
+                dead_variants,
+                false,
+            );
         }
     }
 
     for impl_item in module_items.impl_items() {
-        visitor.check_definition(impl_item.def_id);
+        visitor.check_definition(impl_item.owner_id.def_id);
     }
 
     for foreign_item in module_items.foreign_items() {
-        visitor.check_definition(foreign_item.def_id);
+        visitor.check_definition(foreign_item.owner_id.def_id);
     }
 
     // We do not warn trait items.
diff --git a/compiler/rustc_passes/src/debugger_visualizer.rs b/compiler/rustc_passes/src/debugger_visualizer.rs
index e08683fe2..253b0a88e 100644
--- a/compiler/rustc_passes/src/debugger_visualizer.rs
+++ b/compiler/rustc_passes/src/debugger_visualizer.rs
@@ -13,6 +13,8 @@ use rustc_span::{sym, DebuggerVisualizerFile, DebuggerVisualizerType};
 
 use std::sync::Arc;
 
+use crate::errors::DebugVisualizerUnreadable;
+
 fn check_for_debugger_visualizer<'tcx>(
     tcx: TyCtxt<'tcx>,
     hir_id: HirId,
@@ -54,13 +56,12 @@ fn check_for_debugger_visualizer<'tcx>(
                     debugger_visualizers
                         .insert(DebuggerVisualizerFile::new(Arc::from(contents), visualizer_type));
                 }
-                Err(err) => {
-                    tcx.sess
-                        .struct_span_err(
-                            meta_item.span,
-                            &format!("couldn't read {}: {}", file.display(), err),
-                        )
-                        .emit();
+                Err(error) => {
+                    tcx.sess.emit_err(DebugVisualizerUnreadable {
+                        span: meta_item.span,
+                        file: &file,
+                        error,
+                    });
                 }
             }
         }
diff --git a/compiler/rustc_passes/src/diagnostic_items.rs b/compiler/rustc_passes/src/diagnostic_items.rs
index e6b69d898..a72056e00 100644
--- a/compiler/rustc_passes/src/diagnostic_items.rs
+++ b/compiler/rustc_passes/src/diagnostic_items.rs
@@ -14,7 +14,9 @@ use rustc_hir::diagnostic_items::DiagnosticItems;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::{kw::Empty, sym, Symbol};
+
+use crate::errors::{DuplicateDiagnosticItem, DuplicateDiagnosticItemInCrate};
 
 fn observe_item<'tcx>(
     tcx: TyCtxt<'tcx>,
@@ -33,25 +35,22 @@ fn collect_item(tcx: TyCtxt<'_>, items: &mut DiagnosticItems, name: Symbol, item
     items.id_to_name.insert(item_def_id, name);
     if let Some(original_def_id) = items.name_to_id.insert(name, item_def_id) {
         if original_def_id != item_def_id {
-            let mut err = match tcx.hir().span_if_local(item_def_id) {
-                Some(span) => tcx
-                    .sess
-                    .struct_span_err(span, &format!("duplicate diagnostic item found: `{name}`.")),
-                None => tcx.sess.struct_err(&format!(
-                    "duplicate diagnostic item in crate `{}`: `{}`.",
-                    tcx.crate_name(item_def_id.krate),
-                    name
-                )),
-            };
-            if let Some(span) = tcx.hir().span_if_local(original_def_id) {
-                err.span_note(span, "the diagnostic item is first defined here");
+            let orig_span = tcx.hir().span_if_local(original_def_id);
+            let orig_crate_name = if orig_span.is_some() {
+                None
             } else {
-                err.note(&format!(
-                    "the diagnostic item is first defined in crate `{}`.",
-                    tcx.crate_name(original_def_id.krate)
-                ));
-            }
-            err.emit();
+                Some(tcx.crate_name(original_def_id.krate))
+            };
+            match tcx.hir().span_if_local(item_def_id) {
+                Some(span) => tcx.sess.emit_err(DuplicateDiagnosticItem { span, name }),
+                None => tcx.sess.emit_err(DuplicateDiagnosticItemInCrate {
+                    span: orig_span,
+                    orig_crate_name: orig_crate_name.unwrap_or(Empty),
+                    have_orig_crate_name: orig_crate_name.map(|_| ()),
+                    crate_name: tcx.crate_name(item_def_id.krate),
+                    name,
+                }),
+            };
         }
     }
 }
@@ -74,19 +73,19 @@ fn diagnostic_items<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> DiagnosticItems
     let crate_items = tcx.hir_crate_items(());
 
     for id in crate_items.items() {
-        observe_item(tcx, &mut diagnostic_items, id.def_id);
+        observe_item(tcx, &mut diagnostic_items, id.owner_id.def_id);
     }
 
     for id in crate_items.trait_items() {
-        observe_item(tcx, &mut diagnostic_items, id.def_id);
+        observe_item(tcx, &mut diagnostic_items, id.owner_id.def_id);
     }
 
     for id in crate_items.impl_items() {
-        observe_item(tcx, &mut diagnostic_items, id.def_id);
+        observe_item(tcx, &mut diagnostic_items, id.owner_id.def_id);
     }
 
     for id in crate_items.foreign_items() {
-        observe_item(tcx, &mut diagnostic_items, id.def_id);
+        observe_item(tcx, &mut diagnostic_items, id.owner_id.def_id);
     }
 
     diagnostic_items
diff --git a/compiler/rustc_passes/src/entry.rs b/compiler/rustc_passes/src/entry.rs
index cd10170d3..5885f45ae 100644
--- a/compiler/rustc_passes/src/entry.rs
+++ b/compiler/rustc_passes/src/entry.rs
@@ -1,5 +1,5 @@
 use rustc_ast::entry::EntryPointType;
-use rustc_errors::struct_span_err;
+use rustc_errors::error_code;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::{ItemId, Node, CRATE_HIR_ID};
@@ -8,7 +8,12 @@ use rustc_middle::ty::{DefIdTree, TyCtxt};
 use rustc_session::config::{sigpipe, CrateType, EntryFnType};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
-use rustc_span::{Span, Symbol, DUMMY_SP};
+use rustc_span::{Span, Symbol};
+
+use crate::errors::{
+    AttrOnlyInFunctions, AttrOnlyOnMain, AttrOnlyOnRootMain, ExternMain, MultipleRustcMain,
+    MultipleStartFunctions, NoMainErr, UnixSigpipeValues,
+};
 
 struct EntryContext<'tcx> {
     tcx: TyCtxt<'tcx>,
@@ -57,7 +62,7 @@ fn entry_point_type(ctxt: &EntryContext<'_>, id: ItemId, at_root: bool) -> Entry
     } else if ctxt.tcx.sess.contains_name(attrs, sym::rustc_main) {
         EntryPointType::RustcMainAttr
     } else {
-        if let Some(name) = ctxt.tcx.opt_item_name(id.def_id.to_def_id())
+        if let Some(name) = ctxt.tcx.opt_item_name(id.owner_id.to_def_id())
             && name == sym::main {
             if at_root {
                 // This is a top-level function so can be `main`.
@@ -71,64 +76,57 @@ fn entry_point_type(ctxt: &EntryContext<'_>, id: ItemId, at_root: bool) -> Entry
     }
 }
 
-fn err_if_attr_found(ctxt: &EntryContext<'_>, id: ItemId, sym: Symbol, details: &str) {
+fn attr_span_by_symbol(ctxt: &EntryContext<'_>, id: ItemId, sym: Symbol) -> Option<Span> {
     let attrs = ctxt.tcx.hir().attrs(id.hir_id());
-    if let Some(attr) = ctxt.tcx.sess.find_by_name(attrs, sym) {
-        ctxt.tcx
-            .sess
-            .struct_span_err(attr.span, &format!("`{}` attribute {}", sym, details))
-            .emit();
-    }
+    ctxt.tcx.sess.find_by_name(attrs, sym).map(|attr| attr.span)
 }
 
 fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
-    let at_root = ctxt.tcx.opt_local_parent(id.def_id) == Some(CRATE_DEF_ID);
+    let at_root = ctxt.tcx.opt_local_parent(id.owner_id.def_id) == Some(CRATE_DEF_ID);
 
     match entry_point_type(ctxt, id, at_root) {
         EntryPointType::None => {
-            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on `fn main()`");
+            if let Some(span) = attr_span_by_symbol(ctxt, id, sym::unix_sigpipe) {
+                ctxt.tcx.sess.emit_err(AttrOnlyOnMain { span, attr: sym::unix_sigpipe });
+            }
         }
-        _ if !matches!(ctxt.tcx.def_kind(id.def_id), DefKind::Fn) => {
-            err_if_attr_found(ctxt, id, sym::start, "can only be used on functions");
-            err_if_attr_found(ctxt, id, sym::rustc_main, "can only be used on functions");
+        _ if !matches!(ctxt.tcx.def_kind(id.owner_id), DefKind::Fn) => {
+            for attr in [sym::start, sym::rustc_main] {
+                if let Some(span) = attr_span_by_symbol(ctxt, id, attr) {
+                    ctxt.tcx.sess.emit_err(AttrOnlyInFunctions { span, attr });
+                }
+            }
         }
         EntryPointType::MainNamed => (),
         EntryPointType::OtherMain => {
-            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on root `fn main()`");
-            ctxt.non_main_fns.push(ctxt.tcx.def_span(id.def_id));
+            if let Some(span) = attr_span_by_symbol(ctxt, id, sym::unix_sigpipe) {
+                ctxt.tcx.sess.emit_err(AttrOnlyOnRootMain { span, attr: sym::unix_sigpipe });
+            }
+            ctxt.non_main_fns.push(ctxt.tcx.def_span(id.owner_id));
         }
         EntryPointType::RustcMainAttr => {
             if ctxt.attr_main_fn.is_none() {
-                ctxt.attr_main_fn = Some((id.def_id, ctxt.tcx.def_span(id.def_id.to_def_id())));
+                ctxt.attr_main_fn = Some((id.owner_id.def_id, ctxt.tcx.def_span(id.owner_id)));
             } else {
-                struct_span_err!(
-                    ctxt.tcx.sess,
-                    ctxt.tcx.def_span(id.def_id.to_def_id()),
-                    E0137,
-                    "multiple functions with a `#[rustc_main]` attribute"
-                )
-                .span_label(
-                    ctxt.tcx.def_span(id.def_id.to_def_id()),
-                    "additional `#[rustc_main]` function",
-                )
-                .span_label(ctxt.attr_main_fn.unwrap().1, "first `#[rustc_main]` function")
-                .emit();
+                ctxt.tcx.sess.emit_err(MultipleRustcMain {
+                    span: ctxt.tcx.def_span(id.owner_id.to_def_id()),
+                    first: ctxt.attr_main_fn.unwrap().1,
+                    additional: ctxt.tcx.def_span(id.owner_id.to_def_id()),
+                });
             }
         }
         EntryPointType::Start => {
-            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on `fn main()`");
+            if let Some(span) = attr_span_by_symbol(ctxt, id, sym::unix_sigpipe) {
+                ctxt.tcx.sess.emit_err(AttrOnlyOnMain { span, attr: sym::unix_sigpipe });
+            }
             if ctxt.start_fn.is_none() {
-                ctxt.start_fn = Some((id.def_id, ctxt.tcx.def_span(id.def_id.to_def_id())));
+                ctxt.start_fn = Some((id.owner_id.def_id, ctxt.tcx.def_span(id.owner_id)));
             } else {
-                struct_span_err!(
-                    ctxt.tcx.sess,
-                    ctxt.tcx.def_span(id.def_id.to_def_id()),
-                    E0138,
-                    "multiple `start` functions"
-                )
-                .span_label(ctxt.start_fn.unwrap().1, "previous `#[start]` function here")
-                .span_label(ctxt.tcx.def_span(id.def_id.to_def_id()), "multiple `start` functions")
-                .emit();
+                ctxt.tcx.sess.emit_err(MultipleStartFunctions {
+                    span: ctxt.tcx.def_span(id.owner_id),
+                    labeled: ctxt.tcx.def_span(id.owner_id.to_def_id()),
+                    previous: ctxt.start_fn.unwrap().1,
+                });
             }
         }
     }
@@ -144,12 +142,7 @@ fn configure_main(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) -> Option<(DefId,
         if let Some(main_def) = tcx.resolutions(()).main_def && let Some(def_id) = main_def.opt_fn_def_id() {
             // non-local main imports are handled below
             if let Some(def_id) = def_id.as_local() && matches!(tcx.hir().find_by_def_id(def_id), Some(Node::ForeignItem(_))) {
-                tcx.sess
-                    .struct_span_err(
-                        tcx.def_span(def_id),
-                        "the `main` function cannot be declared in an `extern` block",
-                    )
-                    .emit();
+                tcx.sess.emit_err(ExternMain { span: tcx.def_span(def_id) });
                 return None;
             }
 
@@ -182,12 +175,7 @@ fn sigpipe(tcx: TyCtxt<'_>, def_id: DefId) -> u8 {
                 sigpipe::DEFAULT
             }
             _ => {
-                tcx.sess
-                    .struct_span_err(
-                        attr.span,
-                        "valid values for `#[unix_sigpipe = \"...\"]` are `inherit`, `sig_ign`, or `sig_dfl`",
-                    )
-                    .emit();
+                tcx.sess.emit_err(UnixSigpipeValues { span: attr.span });
                 sigpipe::DEFAULT
             }
         }
@@ -206,52 +194,29 @@ fn no_main_err(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) {
     }
 
     // There is no main function.
-    let mut err = struct_span_err!(
-        tcx.sess,
-        DUMMY_SP,
-        E0601,
-        "`main` function not found in crate `{}`",
-        tcx.crate_name(LOCAL_CRATE)
-    );
-    let filename = &tcx.sess.local_crate_source_file;
-    let note = if !visitor.non_main_fns.is_empty() {
-        for &span in &visitor.non_main_fns {
-            err.span_note(span, "here is a function named `main`");
-        }
-        err.note("you have one or more functions named `main` not defined at the crate level");
-        err.help("consider moving the `main` function definitions");
-        // There were some functions named `main` though. Try to give the user a hint.
-        format!(
-            "the main function must be defined at the crate level{}",
-            filename.as_ref().map(|f| format!(" (in `{}`)", f.display())).unwrap_or_default()
-        )
-    } else if let Some(filename) = filename {
-        format!("consider adding a `main` function to `{}`", filename.display())
-    } else {
-        String::from("consider adding a `main` function at the crate level")
-    };
+    let mut has_filename = true;
+    let filename = tcx.sess.local_crate_source_file.clone().unwrap_or_else(|| {
+        has_filename = false;
+        Default::default()
+    });
+    let main_def_opt = tcx.resolutions(()).main_def;
+    let diagnostic_id = error_code!(E0601);
+    let add_teach_note = tcx.sess.teach(&diagnostic_id);
     // The file may be empty, which leads to the diagnostic machinery not emitting this
     // note. This is a relatively simple way to detect that case and emit a span-less
     // note instead.
-    if tcx.sess.source_map().lookup_line(sp.hi()).is_ok() {
-        err.set_span(sp.shrink_to_hi());
-        err.span_label(sp.shrink_to_hi(), &note);
-    } else {
-        err.note(&note);
-    }
-
-    if let Some(main_def) = tcx.resolutions(()).main_def && main_def.opt_fn_def_id().is_none(){
-        // There is something at `crate::main`, but it is not a function definition.
-        err.span_label(main_def.span, "non-function item at `crate::main` is found");
-    }
-
-    if tcx.sess.teach(&err.get_code().unwrap()) {
-        err.note(
-            "If you don't know the basics of Rust, you can go look to the Rust Book \
-                  to get started: https://doc.rust-lang.org/book/",
-        );
-    }
-    err.emit();
+    let file_empty = !tcx.sess.source_map().lookup_line(sp.hi()).is_ok();
+
+    tcx.sess.emit_err(NoMainErr {
+        sp,
+        crate_name: tcx.crate_name(LOCAL_CRATE),
+        has_filename,
+        filename,
+        file_empty,
+        non_main_fns: visitor.non_main_fns.clone(),
+        main_def_opt,
+        add_teach_note,
+    });
 }
 
 pub fn provide(providers: &mut Providers) {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 96cc8ae98..adaaf5392 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -1,39 +1,49 @@
-use rustc_errors::{Applicability, MultiSpan};
-use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
-use rustc_span::{Span, Symbol};
+use std::{
+    io::Error,
+    path::{Path, PathBuf},
+};
+
+use rustc_ast::Label;
+use rustc_errors::{error_code, Applicability, ErrorGuaranteed, IntoDiagnostic, MultiSpan};
+use rustc_hir::{self as hir, ExprKind, Target};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
+use rustc_middle::ty::{MainDefinition, Ty};
+use rustc_span::{Span, Symbol, DUMMY_SP};
+
+use crate::lang_items::Duplicate;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::outer_crate_level_attr)]
+#[diag(passes_outer_crate_level_attr)]
 pub struct OuterCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::inner_crate_level_attr)]
+#[diag(passes_inner_crate_level_attr)]
 pub struct InnerCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::ignored_attr_with_macro)]
+#[diag(passes_ignored_attr_with_macro)]
 pub struct IgnoredAttrWithMacro<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::ignored_attr)]
+#[diag(passes_ignored_attr)]
 pub struct IgnoredAttr<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::inline_ignored_function_prototype)]
+#[diag(passes_inline_ignored_function_prototype)]
 pub struct IgnoredInlineAttrFnProto;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::inline_ignored_constants)]
+#[diag(passes_inline_ignored_constants)]
 #[warning]
 #[note]
 pub struct IgnoredInlineAttrConstants;
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::inline_not_fn_or_closure, code = "E0518")]
+#[derive(Diagnostic)]
+#[diag(passes_inline_not_fn_or_closure, code = "E0518")]
 pub struct InlineNotFnOrClosure {
     #[primary_span]
     pub attr_span: Span,
@@ -42,19 +52,19 @@ pub struct InlineNotFnOrClosure {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::no_coverage_ignored_function_prototype)]
+#[diag(passes_no_coverage_ignored_function_prototype)]
 pub struct IgnoredNoCoverageFnProto;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::no_coverage_propagate)]
+#[diag(passes_no_coverage_propagate)]
 pub struct IgnoredNoCoveragePropagate;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::no_coverage_fn_defn)]
+#[diag(passes_no_coverage_fn_defn)]
 pub struct IgnoredNoCoverageFnDefn;
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::no_coverage_not_coverable, code = "E0788")]
+#[derive(Diagnostic)]
+#[diag(passes_no_coverage_not_coverable, code = "E0788")]
 pub struct IgnoredNoCoverageNotCoverable {
     #[primary_span]
     pub attr_span: Span,
@@ -62,8 +72,8 @@ pub struct IgnoredNoCoverageNotCoverable {
     pub defn_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::should_be_applied_to_fn)]
+#[derive(Diagnostic)]
+#[diag(passes_should_be_applied_to_fn)]
 pub struct AttrShouldBeAppliedToFn {
     #[primary_span]
     pub attr_span: Span,
@@ -71,15 +81,15 @@ pub struct AttrShouldBeAppliedToFn {
     pub defn_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::naked_tracked_caller, code = "E0736")]
+#[derive(Diagnostic)]
+#[diag(passes_naked_tracked_caller, code = "E0736")]
 pub struct NakedTrackedCaller {
     #[primary_span]
     pub attr_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::should_be_applied_to_fn, code = "E0739")]
+#[derive(Diagnostic)]
+#[diag(passes_should_be_applied_to_fn, code = "E0739")]
 pub struct TrackedCallerWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -87,8 +97,8 @@ pub struct TrackedCallerWrongLocation {
     pub defn_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::should_be_applied_to_struct_enum, code = "E0701")]
+#[derive(Diagnostic)]
+#[diag(passes_should_be_applied_to_struct_enum, code = "E0701")]
 pub struct NonExhaustiveWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -96,8 +106,8 @@ pub struct NonExhaustiveWrongLocation {
     pub defn_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::should_be_applied_to_trait)]
+#[derive(Diagnostic)]
+#[diag(passes_should_be_applied_to_trait)]
 pub struct AttrShouldBeAppliedToTrait {
     #[primary_span]
     pub attr_span: Span,
@@ -106,11 +116,11 @@ pub struct AttrShouldBeAppliedToTrait {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::target_feature_on_statement)]
+#[diag(passes_target_feature_on_statement)]
 pub struct TargetFeatureOnStatement;
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::should_be_applied_to_static)]
+#[derive(Diagnostic)]
+#[diag(passes_should_be_applied_to_static)]
 pub struct AttrShouldBeAppliedToStatic {
     #[primary_span]
     pub attr_span: Span,
@@ -118,24 +128,24 @@ pub struct AttrShouldBeAppliedToStatic {
     pub defn_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_expect_str)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_expect_str)]
 pub struct DocExpectStr<'a> {
     #[primary_span]
     pub attr_span: Span,
     pub attr_name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_empty)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_empty)]
 pub struct DocAliasEmpty<'a> {
     #[primary_span]
     pub span: Span,
     pub attr_str: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_bad_char)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_bad_char)]
 pub struct DocAliasBadChar<'a> {
     #[primary_span]
     pub span: Span,
@@ -143,16 +153,16 @@ pub struct DocAliasBadChar<'a> {
     pub char_: char,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_start_end)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_start_end)]
 pub struct DocAliasStartEnd<'a> {
     #[primary_span]
     pub span: Span,
     pub attr_str: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_bad_location)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_bad_location)]
 pub struct DocAliasBadLocation<'a> {
     #[primary_span]
     pub span: Span,
@@ -160,8 +170,8 @@ pub struct DocAliasBadLocation<'a> {
     pub location: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_not_an_alias)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_not_an_alias)]
 pub struct DocAliasNotAnAlias<'a> {
     #[primary_span]
     pub span: Span,
@@ -169,64 +179,64 @@ pub struct DocAliasNotAnAlias<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_alias_duplicated)]
+#[diag(passes_doc_alias_duplicated)]
 pub struct DocAliasDuplicated {
     #[label]
     pub first_defn: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_not_string_literal)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_not_string_literal)]
 pub struct DocAliasNotStringLiteral {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_alias_malformed)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_alias_malformed)]
 pub struct DocAliasMalformed {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_keyword_empty_mod)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_keyword_empty_mod)]
 pub struct DocKeywordEmptyMod {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_keyword_not_mod)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_keyword_not_mod)]
 pub struct DocKeywordNotMod {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_keyword_invalid_ident)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_keyword_invalid_ident)]
 pub struct DocKeywordInvalidIdent {
     #[primary_span]
     pub span: Span,
     pub doc_keyword: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_fake_variadic_not_valid)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_fake_variadic_not_valid)]
 pub struct DocFakeVariadicNotValid {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_keyword_only_impl)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_keyword_only_impl)]
 pub struct DocKeywordOnlyImpl {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_inline_conflict)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_inline_conflict)]
 #[help]
 pub struct DocKeywordConflict {
     #[primary_span]
@@ -234,17 +244,17 @@ pub struct DocKeywordConflict {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_inline_only_use)]
+#[diag(passes_doc_inline_only_use)]
 #[note]
 pub struct DocInlineOnlyUse {
     #[label]
     pub attr_span: Span,
-    #[label(passes::not_a_use_item_label)]
+    #[label(not_a_use_item_label)]
     pub item_span: Option<Span>,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::doc_attr_not_crate_level)]
+#[derive(Diagnostic)]
+#[diag(passes_doc_attr_not_crate_level)]
 pub struct DocAttrNotCrateLevel<'a> {
     #[primary_span]
     pub span: Span,
@@ -252,29 +262,33 @@ pub struct DocAttrNotCrateLevel<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_test_unknown)]
+#[diag(passes_doc_test_unknown)]
 pub struct DocTestUnknown {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_test_takes_list)]
+#[diag(passes_doc_test_takes_list)]
 pub struct DocTestTakesList;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_primitive)]
+#[diag(passes_doc_cfg_hide_takes_list)]
+pub struct DocCfgHideTakesList;
+
+#[derive(LintDiagnostic)]
+#[diag(passes_doc_primitive)]
 pub struct DocPrimitive;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_test_unknown_any)]
+#[diag(passes_doc_test_unknown_any)]
 pub struct DocTestUnknownAny {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_test_unknown_spotlight)]
+#[diag(passes_doc_test_unknown_spotlight)]
 #[note]
-#[note(passes::no_op_note)]
+#[note(no_op_note)]
 pub struct DocTestUnknownSpotlight {
     pub path: String,
     #[suggestion_short(applicability = "machine-applicable", code = "notable_trait")]
@@ -282,7 +296,7 @@ pub struct DocTestUnknownSpotlight {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_test_unknown_include)]
+#[diag(passes_doc_test_unknown_include)]
 pub struct DocTestUnknownInclude {
     pub path: String,
     pub value: String,
@@ -292,11 +306,11 @@ pub struct DocTestUnknownInclude {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::doc_invalid)]
+#[diag(passes_doc_invalid)]
 pub struct DocInvalid;
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::pass_by_value)]
+#[derive(Diagnostic)]
+#[diag(passes_pass_by_value)]
 pub struct PassByValue {
     #[primary_span]
     pub attr_span: Span,
@@ -304,8 +318,8 @@ pub struct PassByValue {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::allow_incoherent_impl)]
+#[derive(Diagnostic)]
+#[diag(passes_allow_incoherent_impl)]
 pub struct AllowIncoherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -313,8 +327,8 @@ pub struct AllowIncoherentImpl {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::has_incoherent_inherent_impl)]
+#[derive(Diagnostic)]
+#[diag(passes_has_incoherent_inherent_impl)]
 pub struct HasIncoherentInherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -323,21 +337,21 @@ pub struct HasIncoherentInherentImpl {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::must_use_async)]
+#[diag(passes_must_use_async)]
 pub struct MustUseAsync {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::must_use_no_effect)]
+#[diag(passes_must_use_no_effect)]
 pub struct MustUseNoEffect {
     pub article: &'static str,
     pub target: rustc_hir::Target,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::must_not_suspend)]
+#[derive(Diagnostic)]
+#[diag(passes_must_not_suspend)]
 pub struct MustNotSuspend {
     #[primary_span]
     pub attr_span: Span,
@@ -346,7 +360,7 @@ pub struct MustNotSuspend {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::cold)]
+#[diag(passes_cold)]
 #[warning]
 pub struct Cold {
     #[label]
@@ -354,7 +368,7 @@ pub struct Cold {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::link)]
+#[diag(passes_link)]
 #[warning]
 pub struct Link {
     #[label]
@@ -362,7 +376,7 @@ pub struct Link {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::link_name)]
+#[diag(passes_link_name)]
 #[warning]
 pub struct LinkName<'a> {
     #[help]
@@ -372,8 +386,8 @@ pub struct LinkName<'a> {
     pub value: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::no_link)]
+#[derive(Diagnostic)]
+#[diag(passes_no_link)]
 pub struct NoLink {
     #[primary_span]
     pub attr_span: Span,
@@ -381,8 +395,8 @@ pub struct NoLink {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::export_name)]
+#[derive(Diagnostic)]
+#[diag(passes_export_name)]
 pub struct ExportName {
     #[primary_span]
     pub attr_span: Span,
@@ -390,8 +404,8 @@ pub struct ExportName {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_layout_scalar_valid_range_not_struct)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_layout_scalar_valid_range_not_struct)]
 pub struct RustcLayoutScalarValidRangeNotStruct {
     #[primary_span]
     pub attr_span: Span,
@@ -399,15 +413,15 @@ pub struct RustcLayoutScalarValidRangeNotStruct {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_layout_scalar_valid_range_arg)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_layout_scalar_valid_range_arg)]
 pub struct RustcLayoutScalarValidRangeArg {
     #[primary_span]
     pub attr_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_legacy_const_generics_only)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_legacy_const_generics_only)]
 pub struct RustcLegacyConstGenericsOnly {
     #[primary_span]
     pub attr_span: Span,
@@ -415,8 +429,8 @@ pub struct RustcLegacyConstGenericsOnly {
     pub param_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_legacy_const_generics_index)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_legacy_const_generics_index)]
 pub struct RustcLegacyConstGenericsIndex {
     #[primary_span]
     pub attr_span: Span,
@@ -424,8 +438,8 @@ pub struct RustcLegacyConstGenericsIndex {
     pub generics_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_legacy_const_generics_index_exceed)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_legacy_const_generics_index_exceed)]
 pub struct RustcLegacyConstGenericsIndexExceed {
     #[primary_span]
     #[label]
@@ -433,22 +447,22 @@ pub struct RustcLegacyConstGenericsIndexExceed {
     pub arg_count: usize,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_legacy_const_generics_index_negative)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_legacy_const_generics_index_negative)]
 pub struct RustcLegacyConstGenericsIndexNegative {
     #[primary_span]
     pub invalid_args: Vec<Span>,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_dirty_clean)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_dirty_clean)]
 pub struct RustcDirtyClean {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::link_section)]
+#[diag(passes_link_section)]
 #[warning]
 pub struct LinkSection {
     #[label]
@@ -456,52 +470,52 @@ pub struct LinkSection {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::no_mangle_foreign)]
+#[diag(passes_no_mangle_foreign)]
 #[warning]
 #[note]
 pub struct NoMangleForeign {
     #[label]
     pub span: Span,
-    #[suggestion(applicability = "machine-applicable")]
+    #[suggestion(code = "", applicability = "machine-applicable")]
     pub attr_span: Span,
     pub foreign_item_kind: &'static str,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::no_mangle)]
+#[diag(passes_no_mangle)]
 #[warning]
 pub struct NoMangle {
     #[label]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::repr_ident, code = "E0565")]
+#[derive(Diagnostic)]
+#[diag(passes_repr_ident, code = "E0565")]
 pub struct ReprIdent {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::repr_conflicting, code = "E0566")]
+#[diag(passes_repr_conflicting, code = "E0566")]
 pub struct ReprConflicting;
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::used_static)]
+#[derive(Diagnostic)]
+#[diag(passes_used_static)]
 pub struct UsedStatic {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::used_compiler_linker)]
+#[derive(Diagnostic)]
+#[diag(passes_used_compiler_linker)]
 pub struct UsedCompilerLinker {
     #[primary_span]
     pub spans: Vec<Span>,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::allow_internal_unstable)]
+#[derive(Diagnostic)]
+#[diag(passes_allow_internal_unstable)]
 pub struct AllowInternalUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -509,25 +523,34 @@ pub struct AllowInternalUnstable {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::debug_visualizer_placement)]
+#[derive(Diagnostic)]
+#[diag(passes_debug_visualizer_placement)]
 pub struct DebugVisualizerPlacement {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::debug_visualizer_invalid)]
-#[note(passes::note_1)]
-#[note(passes::note_2)]
-#[note(passes::note_3)]
+#[derive(Diagnostic)]
+#[diag(passes_debug_visualizer_invalid)]
+#[note(note_1)]
+#[note(note_2)]
+#[note(note_3)]
 pub struct DebugVisualizerInvalid {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_allow_const_fn_unstable)]
+#[derive(Diagnostic)]
+#[diag(passes_debug_visualizer_unreadable)]
+pub struct DebugVisualizerUnreadable<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub file: &'a Path,
+    pub error: Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_rustc_allow_const_fn_unstable)]
 pub struct RustcAllowConstFnUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -535,8 +558,8 @@ pub struct RustcAllowConstFnUnstable {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_std_internal_symbol)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_std_internal_symbol)]
 pub struct RustcStdInternalSymbol {
     #[primary_span]
     pub attr_span: Span,
@@ -544,66 +567,66 @@ pub struct RustcStdInternalSymbol {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::const_trait)]
+#[derive(Diagnostic)]
+#[diag(passes_const_trait)]
 pub struct ConstTrait {
     #[primary_span]
     pub attr_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::link_ordinal)]
+#[derive(Diagnostic)]
+#[diag(passes_link_ordinal)]
 pub struct LinkOrdinal {
     #[primary_span]
     pub attr_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::stability_promotable)]
+#[derive(Diagnostic)]
+#[diag(passes_stability_promotable)]
 pub struct StabilityPromotable {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::deprecated)]
+#[diag(passes_deprecated)]
 pub struct Deprecated;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::macro_use)]
+#[diag(passes_macro_use)]
 pub struct MacroUse {
     pub name: Symbol,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::macro_export)]
+#[diag(passes_macro_export)]
 pub struct MacroExport;
 
 #[derive(LintDiagnostic)]
-#[diag(passes::plugin_registrar)]
+#[diag(passes_plugin_registrar)]
 pub struct PluginRegistrar;
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum UnusedNote {
-    #[note(passes::unused_empty_lints_note)]
+    #[note(passes_unused_empty_lints_note)]
     EmptyList { name: Symbol },
-    #[note(passes::unused_no_lints_note)]
+    #[note(passes_unused_no_lints_note)]
     NoLints { name: Symbol },
-    #[note(passes::unused_default_method_body_const_note)]
+    #[note(passes_unused_default_method_body_const_note)]
     DefaultMethodBodyConst,
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::unused)]
+#[diag(passes_unused)]
 pub struct Unused {
-    #[suggestion(applicability = "machine-applicable")]
+    #[suggestion(code = "", applicability = "machine-applicable")]
     pub attr_span: Span,
     #[subdiagnostic]
     pub note: UnusedNote,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::non_exported_macro_invalid_attrs, code = "E0518")]
+#[derive(Diagnostic)]
+#[diag(passes_non_exported_macro_invalid_attrs, code = "E0518")]
 pub struct NonExportedMacroInvalidAttrs {
     #[primary_span]
     #[label]
@@ -611,7 +634,7 @@ pub struct NonExportedMacroInvalidAttrs {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(passes::unused_duplicate)]
+#[diag(passes_unused_duplicate)]
 pub struct UnusedDuplicate {
     #[suggestion(code = "", applicability = "machine-applicable")]
     pub this: Span,
@@ -621,8 +644,8 @@ pub struct UnusedDuplicate {
     pub warning: Option<()>,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::unused_multiple)]
+#[derive(Diagnostic)]
+#[diag(passes_unused_multiple)]
 pub struct UnusedMultiple {
     #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
@@ -632,8 +655,8 @@ pub struct UnusedMultiple {
     pub name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_lint_opt_ty)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_lint_opt_ty)]
 pub struct RustcLintOptTy {
     #[primary_span]
     pub attr_span: Span,
@@ -641,8 +664,8 @@ pub struct RustcLintOptTy {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::rustc_lint_opt_deny_field_access)]
+#[derive(Diagnostic)]
+#[diag(passes_rustc_lint_opt_deny_field_access)]
 pub struct RustcLintOptDenyFieldAccess {
     #[primary_span]
     pub attr_span: Span,
@@ -650,11 +673,779 @@ pub struct RustcLintOptDenyFieldAccess {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(passes::collapse_debuginfo)]
+#[derive(Diagnostic)]
+#[diag(passes_collapse_debuginfo)]
 pub struct CollapseDebuginfo {
     #[primary_span]
     pub attr_span: Span,
     #[label]
     pub defn_span: Span,
 }
+
+#[derive(LintDiagnostic)]
+#[diag(passes_deprecated_annotation_has_no_effect)]
+pub struct DeprecatedAnnotationHasNoEffect {
+    #[suggestion(applicability = "machine-applicable", code = "")]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unknown_external_lang_item, code = "E0264")]
+pub struct UnknownExternLangItem {
+    #[primary_span]
+    pub span: Span,
+    pub lang_item: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_missing_panic_handler)]
+pub struct MissingPanicHandler;
+
+#[derive(Diagnostic)]
+#[diag(passes_alloc_func_required)]
+pub struct AllocFuncRequired;
+
+#[derive(Diagnostic)]
+#[diag(passes_missing_alloc_error_handler)]
+pub struct MissingAllocErrorHandler;
+
+#[derive(Diagnostic)]
+#[diag(passes_missing_lang_item)]
+#[note]
+#[help]
+pub struct MissingLangItem {
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_lang_item_on_incorrect_target, code = "E0718")]
+pub struct LangItemOnIncorrectTarget {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub name: Symbol,
+    pub expected_target: Target,
+    pub actual_target: Target,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unknown_lang_item, code = "E0522")]
+pub struct UnknownLangItem {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+pub struct InvalidAttrAtCrateLevel {
+    pub span: Span,
+    pub snippet: Option<String>,
+    pub name: Symbol,
+}
+
+impl IntoDiagnostic<'_> for InvalidAttrAtCrateLevel {
+    fn into_diagnostic(
+        self,
+        handler: &'_ rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag = handler.struct_err(rustc_errors::fluent::passes_invalid_attr_at_crate_level);
+        diag.set_span(self.span);
+        diag.set_arg("name", self.name);
+        // Only emit an error with a suggestion if we can create a string out
+        // of the attribute span
+        if let Some(src) = self.snippet {
+            let replacement = src.replace("#!", "#");
+            diag.span_suggestion_verbose(
+                self.span,
+                rustc_errors::fluent::suggestion,
+                replacement,
+                rustc_errors::Applicability::MachineApplicable,
+            );
+        }
+        diag
+    }
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_duplicate_diagnostic_item)]
+pub struct DuplicateDiagnosticItem {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_duplicate_diagnostic_item_in_crate)]
+pub struct DuplicateDiagnosticItemInCrate {
+    #[note(passes_diagnostic_item_first_defined)]
+    pub span: Option<Span>,
+    pub orig_crate_name: Symbol,
+    #[note]
+    pub have_orig_crate_name: Option<()>,
+    pub crate_name: Symbol,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_abi)]
+pub struct Abi {
+    #[primary_span]
+    pub span: Span,
+    pub abi: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_align)]
+pub struct Align {
+    #[primary_span]
+    pub span: Span,
+    pub align: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_size)]
+pub struct Size {
+    #[primary_span]
+    pub span: Span,
+    pub size: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_homogeneous_aggregate)]
+pub struct HomogeneousAggregate {
+    #[primary_span]
+    pub span: Span,
+    pub homogeneous_aggregate: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_layout_of)]
+pub struct LayoutOf {
+    #[primary_span]
+    pub span: Span,
+    pub normalized_ty: String,
+    pub ty_layout: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unrecognized_field)]
+pub struct UnrecognizedField {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_feature_stable_twice, code = "E0711")]
+pub struct FeatureStableTwice {
+    #[primary_span]
+    pub span: Span,
+    pub feature: Symbol,
+    pub since: Symbol,
+    pub prev_since: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_feature_previously_declared, code = "E0711")]
+pub struct FeaturePreviouslyDeclared<'a, 'b> {
+    #[primary_span]
+    pub span: Span,
+    pub feature: Symbol,
+    pub declared: &'a str,
+    pub prev_declared: &'b str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_expr_not_allowed_in_context, code = "E0744")]
+pub struct ExprNotAllowedInContext<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub expr: String,
+    pub context: &'a str,
+}
+
+pub struct BreakNonLoop<'a> {
+    pub span: Span,
+    pub head: Option<Span>,
+    pub kind: &'a str,
+    pub suggestion: String,
+    pub loop_label: Option<Label>,
+    pub break_label: Option<Label>,
+    pub break_expr_kind: &'a ExprKind<'a>,
+    pub break_expr_span: Span,
+}
+
+impl<'a> IntoDiagnostic<'_> for BreakNonLoop<'a> {
+    fn into_diagnostic(
+        self,
+        handler: &rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag = handler.struct_span_err_with_code(
+            self.span,
+            rustc_errors::fluent::passes_break_non_loop,
+            error_code!(E0571),
+        );
+        diag.set_arg("kind", self.kind);
+        diag.span_label(self.span, rustc_errors::fluent::label);
+        if let Some(head) = self.head {
+            diag.span_label(head, rustc_errors::fluent::label2);
+        }
+        diag.span_suggestion(
+            self.span,
+            rustc_errors::fluent::suggestion,
+            self.suggestion,
+            Applicability::MaybeIncorrect,
+        );
+        if let (Some(label), None) = (self.loop_label, self.break_label) {
+            match self.break_expr_kind {
+                ExprKind::Path(hir::QPath::Resolved(
+                    None,
+                    hir::Path { segments: [segment], res: hir::def::Res::Err, .. },
+                )) if label.ident.to_string() == format!("'{}", segment.ident) => {
+                    // This error is redundant, we will have already emitted a
+                    // suggestion to use the label when `segment` wasn't found
+                    // (hence the `Res::Err` check).
+                    diag.delay_as_bug();
+                }
+                _ => {
+                    diag.span_suggestion(
+                        self.break_expr_span,
+                        rustc_errors::fluent::break_expr_suggestion,
+                        label.ident,
+                        Applicability::MaybeIncorrect,
+                    );
+                }
+            }
+        }
+        diag
+    }
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_continue_labeled_block, code = "E0696")]
+pub struct ContinueLabeledBlock {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(block_label)]
+    pub block_span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_break_inside_closure, code = "E0267")]
+pub struct BreakInsideClosure<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(closure_label)]
+    pub closure_span: Span,
+    pub name: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_break_inside_async_block, code = "E0267")]
+pub struct BreakInsideAsyncBlock<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(async_block_label)]
+    pub closure_span: Span,
+    pub name: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_outside_loop, code = "E0268")]
+pub struct OutsideLoop<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub name: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unlabeled_in_labeled_block, code = "E0695")]
+pub struct UnlabeledInLabeledBlock<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub cf_type: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unlabeled_cf_in_while_condition, code = "E0590")]
+pub struct UnlabeledCfInWhileCondition<'a> {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub cf_type: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_cannot_inline_naked_function)]
+pub struct CannotInlineNakedFunction {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(LintDiagnostic)]
+#[diag(passes_undefined_naked_function_abi)]
+pub struct UndefinedNakedFunctionAbi;
+
+#[derive(Diagnostic)]
+#[diag(passes_no_patterns)]
+pub struct NoPatterns {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_params_not_allowed)]
+#[help]
+pub struct ParamsNotAllowed {
+    #[primary_span]
+    pub span: Span,
+}
+
+pub struct NakedFunctionsAsmBlock {
+    pub span: Span,
+    pub multiple_asms: Vec<Span>,
+    pub non_asms: Vec<Span>,
+}
+
+impl IntoDiagnostic<'_> for NakedFunctionsAsmBlock {
+    fn into_diagnostic(
+        self,
+        handler: &rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag = handler.struct_span_err_with_code(
+            self.span,
+            rustc_errors::fluent::passes_naked_functions_asm_block,
+            error_code!(E0787),
+        );
+        for span in self.multiple_asms.iter() {
+            diag.span_label(*span, rustc_errors::fluent::label_multiple_asm);
+        }
+        for span in self.non_asms.iter() {
+            diag.span_label(*span, rustc_errors::fluent::label_non_asm);
+        }
+        diag
+    }
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_naked_functions_operands, code = "E0787")]
+pub struct NakedFunctionsOperands {
+    #[primary_span]
+    pub unsupported_operands: Vec<Span>,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_naked_functions_asm_options, code = "E0787")]
+pub struct NakedFunctionsAsmOptions {
+    #[primary_span]
+    pub span: Span,
+    pub unsupported_options: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_naked_functions_must_use_noreturn, code = "E0787")]
+pub struct NakedFunctionsMustUseNoreturn {
+    #[primary_span]
+    pub span: Span,
+    #[suggestion(code = ", options(noreturn)", applicability = "machine-applicable")]
+    pub last_span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_attr_only_on_main)]
+pub struct AttrOnlyOnMain {
+    #[primary_span]
+    pub span: Span,
+    pub attr: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_attr_only_on_root_main)]
+pub struct AttrOnlyOnRootMain {
+    #[primary_span]
+    pub span: Span,
+    pub attr: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_attr_only_in_functions)]
+pub struct AttrOnlyInFunctions {
+    #[primary_span]
+    pub span: Span,
+    pub attr: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_multiple_rustc_main, code = "E0137")]
+pub struct MultipleRustcMain {
+    #[primary_span]
+    pub span: Span,
+    #[label(first)]
+    pub first: Span,
+    #[label(additional)]
+    pub additional: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_multiple_start_functions, code = "E0138")]
+pub struct MultipleStartFunctions {
+    #[primary_span]
+    pub span: Span,
+    #[label]
+    pub labeled: Span,
+    #[label(previous)]
+    pub previous: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_extern_main)]
+pub struct ExternMain {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unix_sigpipe_values)]
+pub struct UnixSigpipeValues {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_no_main_function, code = "E0601")]
+pub struct NoMainFunction {
+    #[primary_span]
+    pub span: Span,
+    pub crate_name: String,
+}
+
+pub struct NoMainErr {
+    pub sp: Span,
+    pub crate_name: Symbol,
+    pub has_filename: bool,
+    pub filename: PathBuf,
+    pub file_empty: bool,
+    pub non_main_fns: Vec<Span>,
+    pub main_def_opt: Option<MainDefinition>,
+    pub add_teach_note: bool,
+}
+
+impl<'a> IntoDiagnostic<'a> for NoMainErr {
+    fn into_diagnostic(
+        self,
+        handler: &'a rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'a, ErrorGuaranteed> {
+        let mut diag = handler.struct_span_err_with_code(
+            DUMMY_SP,
+            rustc_errors::fluent::passes_no_main_function,
+            error_code!(E0601),
+        );
+        diag.set_arg("crate_name", self.crate_name);
+        diag.set_arg("filename", self.filename);
+        diag.set_arg("has_filename", self.has_filename);
+        let note = if !self.non_main_fns.is_empty() {
+            for &span in &self.non_main_fns {
+                diag.span_note(span, rustc_errors::fluent::here_is_main);
+            }
+            diag.note(rustc_errors::fluent::one_or_more_possible_main);
+            diag.help(rustc_errors::fluent::consider_moving_main);
+            // There were some functions named `main` though. Try to give the user a hint.
+            rustc_errors::fluent::main_must_be_defined_at_crate
+        } else if self.has_filename {
+            rustc_errors::fluent::consider_adding_main_to_file
+        } else {
+            rustc_errors::fluent::consider_adding_main_at_crate
+        };
+        if self.file_empty {
+            diag.note(note);
+        } else {
+            diag.set_span(self.sp.shrink_to_hi());
+            diag.span_label(self.sp.shrink_to_hi(), note);
+        }
+
+        if let Some(main_def) = self.main_def_opt && main_def.opt_fn_def_id().is_none(){
+            // There is something at `crate::main`, but it is not a function definition.
+            diag.span_label(main_def.span, rustc_errors::fluent::non_function_main);
+        }
+
+        if self.add_teach_note {
+            diag.note(rustc_errors::fluent::teach_note);
+        }
+        diag
+    }
+}
+
+pub struct DuplicateLangItem {
+    pub local_span: Option<Span>,
+    pub lang_item_name: Symbol,
+    pub crate_name: Symbol,
+    pub dependency_of: Symbol,
+    pub is_local: bool,
+    pub path: String,
+    pub first_defined_span: Option<Span>,
+    pub orig_crate_name: Symbol,
+    pub orig_dependency_of: Symbol,
+    pub orig_is_local: bool,
+    pub orig_path: String,
+    pub(crate) duplicate: Duplicate,
+}
+
+impl IntoDiagnostic<'_> for DuplicateLangItem {
+    fn into_diagnostic(
+        self,
+        handler: &rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag = handler.struct_err_with_code(
+            match self.duplicate {
+                Duplicate::Plain => rustc_errors::fluent::passes_duplicate_lang_item,
+
+                Duplicate::Crate => rustc_errors::fluent::passes_duplicate_lang_item_crate,
+                Duplicate::CrateDepends => {
+                    rustc_errors::fluent::passes_duplicate_lang_item_crate_depends
+                }
+            },
+            error_code!(E0152),
+        );
+        diag.set_arg("lang_item_name", self.lang_item_name);
+        diag.set_arg("crate_name", self.crate_name);
+        diag.set_arg("dependency_of", self.dependency_of);
+        diag.set_arg("path", self.path);
+        diag.set_arg("orig_crate_name", self.orig_crate_name);
+        diag.set_arg("orig_dependency_of", self.orig_dependency_of);
+        diag.set_arg("orig_path", self.orig_path);
+        if let Some(span) = self.local_span {
+            diag.set_span(span);
+        }
+        if let Some(span) = self.first_defined_span {
+            diag.span_note(span, rustc_errors::fluent::first_defined_span);
+        } else {
+            if self.orig_dependency_of.is_empty() {
+                diag.note(rustc_errors::fluent::first_defined_crate);
+            } else {
+                diag.note(rustc_errors::fluent::first_defined_crate_depends);
+            }
+
+            if self.orig_is_local {
+                diag.note(rustc_errors::fluent::first_definition_local);
+            } else {
+                diag.note(rustc_errors::fluent::first_definition_path);
+            }
+
+            if self.is_local {
+                diag.note(rustc_errors::fluent::second_definition_local);
+            } else {
+                diag.note(rustc_errors::fluent::second_definition_path);
+            }
+        }
+        diag
+    }
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_incorrect_target, code = "E0718")]
+pub struct IncorrectTarget<'a> {
+    #[primary_span]
+    pub span: Span,
+    #[label]
+    pub generics_span: Span,
+    pub name: &'a str, // cannot be symbol because it renders e.g. `r#fn` instead of `fn`
+    pub kind: &'static str,
+    pub num: usize,
+    pub actual_num: usize,
+    pub at_least: bool,
+}
+
+#[derive(LintDiagnostic)]
+#[diag(passes_useless_assignment)]
+pub struct UselessAssignment<'a> {
+    pub is_field_assign: bool,
+    pub ty: Ty<'a>,
+}
+
+#[derive(LintDiagnostic)]
+#[diag(passes_only_has_effect_on)]
+pub struct OnlyHasEffectOn {
+    pub attr_name: Symbol,
+    pub target_name: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_object_lifetime_err)]
+pub struct ObjectLifetimeErr {
+    #[primary_span]
+    pub span: Span,
+    pub repr: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unrecognized_repr_hint, code = "E0552")]
+#[help]
+pub struct UnrecognizedReprHint {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+pub enum AttrApplication {
+    #[diag(passes_attr_application_enum, code = "E0517")]
+    Enum {
+        #[primary_span]
+        hint_span: Span,
+        #[label]
+        span: Span,
+    },
+    #[diag(passes_attr_application_struct, code = "E0517")]
+    Struct {
+        #[primary_span]
+        hint_span: Span,
+        #[label]
+        span: Span,
+    },
+    #[diag(passes_attr_application_struct_union, code = "E0517")]
+    StructUnion {
+        #[primary_span]
+        hint_span: Span,
+        #[label]
+        span: Span,
+    },
+    #[diag(passes_attr_application_struct_enum_union, code = "E0517")]
+    StructEnumUnion {
+        #[primary_span]
+        hint_span: Span,
+        #[label]
+        span: Span,
+    },
+    #[diag(passes_attr_application_struct_enum_function_union, code = "E0517")]
+    StructEnumFunctionUnion {
+        #[primary_span]
+        hint_span: Span,
+        #[label]
+        span: Span,
+    },
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_transparent_incompatible, code = "E0692")]
+pub struct TransparentIncompatible {
+    #[primary_span]
+    pub hint_spans: Vec<Span>,
+    pub target: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_deprecated_attribute, code = "E0549")]
+pub struct DeprecatedAttribute {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_useless_stability)]
+pub struct UselessStability {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(item)]
+    pub item_sp: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_invalid_stability)]
+pub struct InvalidStability {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(item)]
+    pub item_sp: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_cannot_stabilize_deprecated)]
+pub struct CannotStabilizeDeprecated {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(item)]
+    pub item_sp: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_invalid_deprecation_version)]
+pub struct InvalidDeprecationVersion {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(item)]
+    pub item_sp: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_missing_stability_attr)]
+pub struct MissingStabilityAttr<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub descr: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_missing_const_stab_attr)]
+pub struct MissingConstStabAttr<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub descr: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_trait_impl_const_stable)]
+#[note]
+pub struct TraitImplConstStable {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_feature_only_on_nightly, code = "E0554")]
+pub struct FeatureOnlyOnNightly {
+    #[primary_span]
+    pub span: Span,
+    pub release_channel: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_unknown_feature, code = "E0635")]
+pub struct UnknownFeature {
+    #[primary_span]
+    pub span: Span,
+    pub feature: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_implied_feature_not_exist)]
+pub struct ImpliedFeatureNotExist {
+    #[primary_span]
+    pub span: Span,
+    pub feature: Symbol,
+    pub implied_by: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(passes_duplicate_feature_err, code = "E0636")]
+pub struct DuplicateFeatureErr {
+    #[primary_span]
+    pub span: Span,
+    pub feature: Symbol,
+}
+#[derive(Diagnostic)]
+#[diag(passes_missing_const_err)]
+pub struct MissingConstErr {
+    #[primary_span]
+    #[help]
+    pub fn_sig_span: Span,
+    #[label]
+    pub const_span: Span,
+}
diff --git a/compiler/rustc_passes/src/hir_id_validator.rs b/compiler/rustc_passes/src/hir_id_validator.rs
index 3bb8c0bb4..88bb39deb 100644
--- a/compiler/rustc_passes/src/hir_id_validator.rs
+++ b/compiler/rustc_passes/src/hir_id_validator.rs
@@ -1,6 +1,5 @@
 use rustc_data_structures::sync::Lock;
 use rustc_hir as hir;
-use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
 use rustc_hir::intravisit;
 use rustc_hir::{HirId, ItemLocalId};
 use rustc_index::bit_set::GrowableBitSet;
@@ -42,7 +41,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
 
 struct HirIdValidator<'a, 'hir> {
     hir_map: Map<'hir>,
-    owner: Option<LocalDefId>,
+    owner: Option<hir::OwnerId>,
     hir_ids_seen: GrowableBitSet<ItemLocalId>,
     errors: &'a Lock<Vec<String>>,
 }
@@ -63,12 +62,12 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
         self.errors.lock().push(f());
     }
 
-    fn check<F: FnOnce(&mut HirIdValidator<'a, 'hir>)>(&mut self, owner: LocalDefId, walk: F) {
+    fn check<F: FnOnce(&mut HirIdValidator<'a, 'hir>)>(&mut self, owner: hir::OwnerId, walk: F) {
         assert!(self.owner.is_none());
         self.owner = Some(owner);
         walk(self);
 
-        if owner == CRATE_DEF_ID {
+        if owner == hir::CRATE_OWNER_ID {
             return;
         }
 
@@ -97,14 +96,14 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
                 missing_items.push(format!(
                     "[local_id: {}, owner: {}]",
                     local_id,
-                    self.hir_map.def_path(owner).to_string_no_crate_verbose()
+                    self.hir_map.def_path(owner.def_id).to_string_no_crate_verbose()
                 ));
             }
             self.error(|| {
                 format!(
                     "ItemLocalIds not assigned densely in {}. \
                 Max ItemLocalId = {}, missing IDs = {:#?}; seens IDs = {:#?}",
-                    self.hir_map.def_path(owner).to_string_no_crate_verbose(),
+                    self.hir_map.def_path(owner.def_id).to_string_no_crate_verbose(),
                     max,
                     missing_items,
                     self.hir_ids_seen
@@ -127,7 +126,7 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
 
     fn visit_item(&mut self, i: &'hir hir::Item<'hir>) {
         let mut inner_visitor = self.new_visitor(self.hir_map);
-        inner_visitor.check(i.def_id, |this| intravisit::walk_item(this, i));
+        inner_visitor.check(i.owner_id, |this| intravisit::walk_item(this, i));
     }
 
     fn visit_id(&mut self, hir_id: HirId) {
@@ -138,8 +137,8 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
                 format!(
                     "HirIdValidator: The recorded owner of {} is {} instead of {}",
                     self.hir_map.node_to_string(hir_id),
-                    self.hir_map.def_path(hir_id.owner).to_string_no_crate_verbose(),
-                    self.hir_map.def_path(owner).to_string_no_crate_verbose()
+                    self.hir_map.def_path(hir_id.owner.def_id).to_string_no_crate_verbose(),
+                    self.hir_map.def_path(owner.def_id).to_string_no_crate_verbose()
                 )
             });
         }
@@ -149,16 +148,16 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
 
     fn visit_foreign_item(&mut self, i: &'hir hir::ForeignItem<'hir>) {
         let mut inner_visitor = self.new_visitor(self.hir_map);
-        inner_visitor.check(i.def_id, |this| intravisit::walk_foreign_item(this, i));
+        inner_visitor.check(i.owner_id, |this| intravisit::walk_foreign_item(this, i));
     }
 
     fn visit_trait_item(&mut self, i: &'hir hir::TraitItem<'hir>) {
         let mut inner_visitor = self.new_visitor(self.hir_map);
-        inner_visitor.check(i.def_id, |this| intravisit::walk_trait_item(this, i));
+        inner_visitor.check(i.owner_id, |this| intravisit::walk_trait_item(this, i));
     }
 
     fn visit_impl_item(&mut self, i: &'hir hir::ImplItem<'hir>) {
         let mut inner_visitor = self.new_visitor(self.hir_map);
-        inner_visitor.check(i.def_id, |this| intravisit::walk_impl_item(this, i));
+        inner_visitor.check(i.owner_id, |this| intravisit::walk_impl_item(this, i));
     }
 }
diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index 0be2fc053..33220fd2b 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -391,7 +391,7 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_impl_item(&mut self, ii: &'v hir::ImplItem<'v>) {
         record_variants!(
             (self, ii, ii.kind, Id::Node(ii.hir_id()), hir, ImplItem, ImplItemKind),
-            [Const, Fn, TyAlias]
+            [Const, Fn, Type]
         );
         hir_visit::walk_impl_item(self, ii)
     }
@@ -620,7 +620,7 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_assoc_item(&mut self, i: &'v ast::AssocItem, ctxt: ast_visit::AssocCtxt) {
         record_variants!(
             (self, i, i.kind, Id::None, ast, AssocItem, AssocItemKind),
-            [Const, Fn, TyAlias, MacCall]
+            [Const, Fn, Type, MacCall]
         );
         ast_visit::walk_assoc_item(self, i, ctxt);
     }
diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs
index 79900a90a..df811be2a 100644
--- a/compiler/rustc_passes/src/lang_items.rs
+++ b/compiler/rustc_passes/src/lang_items.rs
@@ -8,9 +8,11 @@
 //! * Functions called by the compiler itself.
 
 use crate::check_attr::target_from_impl_item;
+use crate::errors::{
+    DuplicateLangItem, IncorrectTarget, LangItemOnIncorrectTarget, UnknownLangItem,
+};
 use crate::weak_lang_items;
 
-use rustc_errors::{pluralize, struct_span_err};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
@@ -18,10 +20,16 @@ use rustc_hir::lang_items::{extract, GenericRequirement, ITEM_REFS};
 use rustc_hir::{HirId, LangItem, LanguageItems, Target};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::cstore::ExternCrate;
-use rustc_span::Span;
+use rustc_span::{symbol::kw::Empty, Span};
 
 use rustc_middle::ty::query::Providers;
 
+pub(crate) enum Duplicate {
+    Plain,
+    Crate,
+    CrateDepends,
+}
+
 struct LanguageItemCollector<'tcx> {
     items: LanguageItems,
     tcx: TyCtxt<'tcx>,
@@ -34,42 +42,24 @@ impl<'tcx> LanguageItemCollector<'tcx> {
 
     fn check_for_lang(&mut self, actual_target: Target, hir_id: HirId) {
         let attrs = self.tcx.hir().attrs(hir_id);
-        if let Some((value, span)) = extract(&attrs) {
-            match ITEM_REFS.get(&value).cloned() {
+        if let Some((name, span)) = extract(&attrs) {
+            match ITEM_REFS.get(&name).cloned() {
                 // Known lang item with attribute on correct target.
                 Some((item_index, expected_target)) if actual_target == expected_target => {
                     self.collect_item_extended(item_index, hir_id, span);
                 }
                 // Known lang item with attribute on incorrect target.
                 Some((_, expected_target)) => {
-                    struct_span_err!(
-                        self.tcx.sess,
+                    self.tcx.sess.emit_err(LangItemOnIncorrectTarget {
                         span,
-                        E0718,
-                        "`{}` language item must be applied to a {}",
-                        value,
+                        name,
                         expected_target,
-                    )
-                    .span_label(
-                        span,
-                        format!(
-                            "attribute should be applied to a {}, not a {}",
-                            expected_target, actual_target,
-                        ),
-                    )
-                    .emit();
+                        actual_target,
+                    });
                 }
                 // Unknown lang item.
                 _ => {
-                    struct_span_err!(
-                        self.tcx.sess,
-                        span,
-                        E0522,
-                        "definition of an unknown language item: `{}`",
-                        value
-                    )
-                    .span_label(span, format!("definition of unknown language item `{}`", value))
-                    .emit();
+                    self.tcx.sess.emit_err(UnknownLangItem { span, name });
                 }
             }
         }
@@ -79,74 +69,72 @@ impl<'tcx> LanguageItemCollector<'tcx> {
         // Check for duplicates.
         if let Some(original_def_id) = self.items.items[item_index] {
             if original_def_id != item_def_id {
-                let lang_item = LangItem::from_u32(item_index as u32).unwrap();
-                let name = lang_item.name();
-                let mut err = match self.tcx.hir().span_if_local(item_def_id) {
-                    Some(span) => struct_span_err!(
-                        self.tcx.sess,
-                        span,
-                        E0152,
-                        "found duplicate lang item `{}`",
-                        name
-                    ),
-                    None => match self.tcx.extern_crate(item_def_id) {
-                        Some(ExternCrate { dependency_of, .. }) => {
-                            self.tcx.sess.struct_err(&format!(
-                                "duplicate lang item in crate `{}` (which `{}` depends on): `{}`.",
-                                self.tcx.crate_name(item_def_id.krate),
-                                self.tcx.crate_name(*dependency_of),
-                                name
-                            ))
-                        }
-                        _ => self.tcx.sess.struct_err(&format!(
-                            "duplicate lang item in crate `{}`: `{}`.",
-                            self.tcx.crate_name(item_def_id.krate),
-                            name
-                        )),
-                    },
+                let local_span = self.tcx.hir().span_if_local(item_def_id);
+                let lang_item_name = LangItem::from_u32(item_index as u32).unwrap().name();
+                let crate_name = self.tcx.crate_name(item_def_id.krate);
+                let mut dependency_of = Empty;
+                let is_local = item_def_id.is_local();
+                let path = if is_local {
+                    String::new()
+                } else {
+                    self.tcx
+                        .crate_extern_paths(item_def_id.krate)
+                        .iter()
+                        .map(|p| p.display().to_string())
+                        .collect::<Vec<_>>()
+                        .join(", ")
+                        .into()
                 };
-                if let Some(span) = self.tcx.hir().span_if_local(original_def_id) {
-                    err.span_note(span, "the lang item is first defined here");
+                let first_defined_span = self.tcx.hir().span_if_local(original_def_id);
+                let mut orig_crate_name = Empty;
+                let mut orig_dependency_of = Empty;
+                let orig_is_local = original_def_id.is_local();
+                let orig_path = if orig_is_local {
+                    String::new()
                 } else {
-                    match self.tcx.extern_crate(original_def_id) {
-                        Some(ExternCrate { dependency_of, .. }) => {
-                            err.note(&format!(
-                                "the lang item is first defined in crate `{}` (which `{}` depends on)",
-                                self.tcx.crate_name(original_def_id.krate),
-                                self.tcx.crate_name(*dependency_of)
-                            ));
-                        }
-                        _ => {
-                            err.note(&format!(
-                                "the lang item is first defined in crate `{}`.",
-                                self.tcx.crate_name(original_def_id.krate)
-                            ));
-                        }
+                    self.tcx
+                        .crate_extern_paths(original_def_id.krate)
+                        .iter()
+                        .map(|p| p.display().to_string())
+                        .collect::<Vec<_>>()
+                        .join(", ")
+                        .into()
+                };
+                if first_defined_span.is_none() {
+                    orig_crate_name = self.tcx.crate_name(original_def_id.krate);
+                    if let Some(ExternCrate { dependency_of: inner_dependency_of, .. }) =
+                        self.tcx.extern_crate(original_def_id)
+                    {
+                        orig_dependency_of = self.tcx.crate_name(*inner_dependency_of);
                     }
-                    let mut note_def = |which, def_id: DefId| {
-                        let crate_name = self.tcx.crate_name(def_id.krate);
-                        let note = if def_id.is_local() {
-                            format!("{} definition in the local crate (`{}`)", which, crate_name)
-                        } else {
-                            let paths: Vec<_> = self
-                                .tcx
-                                .crate_extern_paths(def_id.krate)
-                                .iter()
-                                .map(|p| p.display().to_string())
-                                .collect();
-                            format!(
-                                "{} definition in `{}` loaded from {}",
-                                which,
-                                crate_name,
-                                paths.join(", ")
-                            )
-                        };
-                        err.note(&note);
-                    };
-                    note_def("first", original_def_id);
-                    note_def("second", item_def_id);
                 }
-                err.emit();
+
+                let duplicate = if local_span.is_some() {
+                    Duplicate::Plain
+                } else {
+                    match self.tcx.extern_crate(item_def_id) {
+                        Some(ExternCrate { dependency_of: inner_dependency_of, .. }) => {
+                            dependency_of = self.tcx.crate_name(*inner_dependency_of);
+                            Duplicate::CrateDepends
+                        }
+                        _ => Duplicate::Crate,
+                    }
+                };
+
+                self.tcx.sess.emit_err(DuplicateLangItem {
+                    local_span,
+                    lang_item_name,
+                    crate_name,
+                    dependency_of,
+                    is_local,
+                    path,
+                    first_defined_span,
+                    orig_crate_name,
+                    orig_dependency_of,
+                    orig_is_local,
+                    orig_path,
+                    duplicate,
+                });
             }
         }
 
@@ -179,41 +167,30 @@ impl<'tcx> LanguageItemCollector<'tcx> {
                 None => (0, *item_span),
             };
 
+            let mut at_least = false;
             let required = match lang_item.required_generics() {
-                GenericRequirement::Exact(num) if num != actual_num => {
-                    Some((format!("{}", num), pluralize!(num)))
-                }
+                GenericRequirement::Exact(num) if num != actual_num => Some(num),
                 GenericRequirement::Minimum(num) if actual_num < num => {
-                    Some((format!("at least {}", num), pluralize!(num)))
-                }
+                    at_least = true;
+                    Some(num)}
+                ,
                 // If the number matches, or there is no requirement, handle it normally
                 _ => None,
             };
 
-            if let Some((range_str, pluralized)) = required {
+            if let Some(num) = required {
                 // We are issuing E0718 "incorrect target" here, because while the
                 // item kind of the target is correct, the target is still wrong
                 // because of the wrong number of generic arguments.
-                struct_span_err!(
-                    self.tcx.sess,
+                self.tcx.sess.emit_err(IncorrectTarget {
                     span,
-                    E0718,
-                    "`{}` language item must be applied to a {} with {} generic argument{}",
-                    name,
-                    kind.descr(),
-                    range_str,
-                    pluralized,
-                )
-                .span_label(
                     generics_span,
-                    format!(
-                        "this {} has {} generic argument{}",
-                        kind.descr(),
-                        actual_num,
-                        pluralize!(actual_num),
-                    ),
-                )
-                .emit();
+                    name: name.as_str(),
+                    kind: kind.descr(),
+                    num,
+                    actual_num,
+                    at_least,
+                });
 
                 // return early to not collect the lang item
                 return;
@@ -240,9 +217,9 @@ fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
     let crate_items = tcx.hir_crate_items(());
 
     for id in crate_items.items() {
-        collector.check_for_lang(Target::from_def_kind(tcx.def_kind(id.def_id)), id.hir_id());
+        collector.check_for_lang(Target::from_def_kind(tcx.def_kind(id.owner_id)), id.hir_id());
 
-        if matches!(tcx.def_kind(id.def_id), DefKind::Enum) {
+        if matches!(tcx.def_kind(id.owner_id), DefKind::Enum) {
             let item = tcx.hir().item(id);
             if let hir::ItemKind::Enum(def, ..) = &item.kind {
                 for variant in def.variants {
diff --git a/compiler/rustc_passes/src/layout_test.rs b/compiler/rustc_passes/src/layout_test.rs
index fd03f6571..5322baee7 100644
--- a/compiler/rustc_passes/src/layout_test.rs
+++ b/compiler/rustc_passes/src/layout_test.rs
@@ -3,20 +3,23 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::ty::layout::{HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
+use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_target::abi::{HasDataLayout, TargetDataLayout};
 
+use crate::errors::{Abi, Align, HomogeneousAggregate, LayoutOf, Size, UnrecognizedField};
+
 pub fn test_layout(tcx: TyCtxt<'_>) {
     if tcx.features().rustc_attrs {
         // if the `rustc_attrs` feature is not enabled, don't bother testing layout
         for id in tcx.hir().items() {
             if matches!(
-                tcx.def_kind(id.def_id),
+                tcx.def_kind(id.owner_id),
                 DefKind::TyAlias | DefKind::Enum | DefKind::Struct | DefKind::Union
             ) {
-                for attr in tcx.get_attrs(id.def_id.to_def_id(), sym::rustc_layout) {
-                    dump_layout_of(tcx, id.def_id, attr);
+                for attr in tcx.get_attrs(id.owner_id.to_def_id(), sym::rustc_layout) {
+                    dump_layout_of(tcx, id.owner_id.def_id, attr);
                 }
             }
         }
@@ -35,62 +38,64 @@ fn dump_layout_of<'tcx>(tcx: TyCtxt<'tcx>, item_def_id: LocalDefId, attr: &Attri
             for meta_item in meta_items {
                 match meta_item.name_or_empty() {
                     sym::abi => {
-                        tcx.sess.span_err(
-                            tcx.def_span(item_def_id.to_def_id()),
-                            &format!("abi: {:?}", ty_layout.abi),
-                        );
+                        tcx.sess.emit_err(Abi {
+                            span: tcx.def_span(item_def_id.to_def_id()),
+                            abi: format!("{:?}", ty_layout.abi),
+                        });
                     }
 
                     sym::align => {
-                        tcx.sess.span_err(
-                            tcx.def_span(item_def_id.to_def_id()),
-                            &format!("align: {:?}", ty_layout.align),
-                        );
+                        tcx.sess.emit_err(Align {
+                            span: tcx.def_span(item_def_id.to_def_id()),
+                            align: format!("{:?}", ty_layout.align),
+                        });
                     }
 
                     sym::size => {
-                        tcx.sess.span_err(
-                            tcx.def_span(item_def_id.to_def_id()),
-                            &format!("size: {:?}", ty_layout.size),
-                        );
+                        tcx.sess.emit_err(Size {
+                            span: tcx.def_span(item_def_id.to_def_id()),
+                            size: format!("{:?}", ty_layout.size),
+                        });
                     }
 
                     sym::homogeneous_aggregate => {
-                        tcx.sess.span_err(
-                            tcx.def_span(item_def_id.to_def_id()),
-                            &format!(
-                                "homogeneous_aggregate: {:?}",
-                                ty_layout.homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env }),
+                        tcx.sess.emit_err(HomogeneousAggregate {
+                            span: tcx.def_span(item_def_id.to_def_id()),
+                            homogeneous_aggregate: format!(
+                                "{:?}",
+                                ty_layout.homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env })
                             ),
-                        );
+                        });
                     }
 
                     sym::debug => {
-                        let normalized_ty = tcx.normalize_erasing_regions(
-                            param_env.with_reveal_all_normalized(tcx),
-                            ty,
-                        );
-                        tcx.sess.span_err(
-                            tcx.def_span(item_def_id.to_def_id()),
-                            &format!("layout_of({:?}) = {:#?}", normalized_ty, *ty_layout),
+                        let normalized_ty = format!(
+                            "{:?}",
+                            tcx.normalize_erasing_regions(
+                                param_env.with_reveal_all_normalized(tcx),
+                                ty,
+                            )
                         );
+                        let ty_layout = format!("{:#?}", *ty_layout);
+                        tcx.sess.emit_err(LayoutOf {
+                            span: tcx.def_span(item_def_id.to_def_id()),
+                            normalized_ty,
+                            ty_layout,
+                        });
                     }
 
                     name => {
-                        tcx.sess.span_err(
-                            meta_item.span(),
-                            &format!("unrecognized field name `{}`", name),
-                        );
+                        tcx.sess.emit_err(UnrecognizedField { span: meta_item.span(), name });
                     }
                 }
             }
         }
 
         Err(layout_error) => {
-            tcx.sess.span_err(
-                tcx.def_span(item_def_id.to_def_id()),
-                &format!("layout error: {:?}", layout_error),
-            );
+            tcx.sess.emit_fatal(Spanned {
+                node: layout_error,
+                span: tcx.def_span(item_def_id.to_def_id()),
+            });
         }
     }
 }
diff --git a/compiler/rustc_passes/src/lib.rs b/compiler/rustc_passes/src/lib.rs
index 39ebb8db2..15f60f626 100644
--- a/compiler/rustc_passes/src/lib.rs
+++ b/compiler/rustc_passes/src/lib.rs
@@ -5,10 +5,11 @@
 //! This API is completely unstable and subject to change.
 
 #![allow(rustc::potential_query_instability)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(try_blocks)]
diff --git a/compiler/rustc_passes/src/lib_features.rs b/compiler/rustc_passes/src/lib_features.rs
index 04173c792..b5843c0ae 100644
--- a/compiler/rustc_passes/src/lib_features.rs
+++ b/compiler/rustc_passes/src/lib_features.rs
@@ -6,7 +6,6 @@
 
 use rustc_ast::{Attribute, MetaItemKind};
 use rustc_attr::{rust_version_symbol, VERSION_PLACEHOLDER};
-use rustc_errors::struct_span_err;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::lib_features::LibFeatures;
@@ -15,6 +14,8 @@ use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::Symbol;
 use rustc_span::{sym, Span};
 
+use crate::errors::{FeaturePreviouslyDeclared, FeatureStableTwice};
+
 fn new_lib_features() -> LibFeatures {
     LibFeatures { stable: Default::default(), unstable: Default::default() }
 }
@@ -92,14 +93,12 @@ impl<'tcx> LibFeatureCollector<'tcx> {
             (Some(since), _, false) => {
                 if let Some((prev_since, _)) = self.lib_features.stable.get(&feature) {
                     if *prev_since != since {
-                        self.span_feature_error(
+                        self.tcx.sess.emit_err(FeatureStableTwice {
                             span,
-                            &format!(
-                                "feature `{}` is declared stable since {}, \
-                                 but was previously declared stable since {}",
-                                feature, since, prev_since,
-                            ),
-                        );
+                            feature,
+                            since,
+                            prev_since: *prev_since,
+                        });
                         return;
                     }
                 }
@@ -110,22 +109,17 @@ impl<'tcx> LibFeatureCollector<'tcx> {
                 self.lib_features.unstable.insert(feature, span);
             }
             (Some(_), _, true) | (None, true, _) => {
-                self.span_feature_error(
+                let declared = if since.is_some() { "stable" } else { "unstable" };
+                let prev_declared = if since.is_none() { "stable" } else { "unstable" };
+                self.tcx.sess.emit_err(FeaturePreviouslyDeclared {
                     span,
-                    &format!(
-                        "feature `{}` is declared {}, but was previously declared {}",
-                        feature,
-                        if since.is_some() { "stable" } else { "unstable" },
-                        if since.is_none() { "stable" } else { "unstable" },
-                    ),
-                );
+                    feature,
+                    declared,
+                    prev_declared,
+                });
             }
         }
     }
-
-    fn span_feature_error(&self, span: Span, msg: &str) {
-        struct_span_err!(self.tcx.sess, span, E0711, "{}", &msg).emit();
-    }
 }
 
 impl<'tcx> Visitor<'tcx> for LibFeatureCollector<'tcx> {
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 6a4cd79cd..c6fe40f72 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -1319,14 +1319,14 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             // that we do not emit the same warning twice if the uninhabited type
             // is indeed `!`.
 
+            let msg = format!("unreachable {}", descr);
             self.ir.tcx.struct_span_lint_hir(
                 lint::builtin::UNREACHABLE_CODE,
                 expr_id,
                 expr_span,
-                |lint| {
-                    let msg = format!("unreachable {}", descr);
-                    lint.build(&msg)
-                        .span_label(expr_span, &msg)
+                &msg,
+                |diag| {
+                    diag.span_label(expr_span, &msg)
                         .span_label(orig_span, "any code following this expression is unreachable")
                         .span_note(
                             orig_span,
@@ -1335,7 +1335,6 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                                 orig_ty
                             ),
                         )
-                        .emit();
                 },
             );
         }
@@ -1491,14 +1490,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
                                 lint::builtin::UNUSED_ASSIGNMENTS,
                                 var_hir_id,
                                 vec![span],
-                                |lint| {
-                                    lint.build(&format!(
-                                        "value captured by `{}` is never read",
-                                        name
-                                    ))
-                                    .help("did you mean to capture by reference instead?")
-                                    .emit();
-                                },
+                                format!("value captured by `{}` is never read", name),
+                                |lint| lint.help("did you mean to capture by reference instead?"),
                             );
                         }
                     }
@@ -1508,11 +1501,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             lint::builtin::UNUSED_VARIABLES,
                             var_hir_id,
                             vec![span],
-                            |lint| {
-                                lint.build(&format!("unused variable: `{}`", name))
-                                    .help("did you mean to capture by reference instead?")
-                                    .emit();
-                            },
+                            format!("unused variable: `{}`", name),
+                            |lint| lint.help("did you mean to capture by reference instead?"),
                         );
                     }
                 }
@@ -1601,20 +1591,17 @@ impl<'tcx> Liveness<'_, 'tcx> {
                         .into_iter()
                         .map(|(_, _, ident_span)| ident_span)
                         .collect::<Vec<_>>(),
-                    |lint| {
-                        lint.build(&format!("variable `{}` is assigned to, but never used", name))
-                            .note(&format!("consider using `_{}` instead", name))
-                            .emit();
-                    },
+                    format!("variable `{}` is assigned to, but never used", name),
+                    |lint| lint.note(&format!("consider using `_{}` instead", name)),
                 )
             } else if can_remove {
                 self.ir.tcx.struct_span_lint_hir(
                     lint::builtin::UNUSED_VARIABLES,
                     first_hir_id,
                     hir_ids_and_spans.iter().map(|(_, pat_span, _)| *pat_span).collect::<Vec<_>>(),
+                    format!("unused variable: `{}`", name),
                     |lint| {
-                        let mut err = lint.build(&format!("unused variable: `{}`", name));
-                        err.multipart_suggestion(
+                        lint.multipart_suggestion(
                             "try removing the field",
                             hir_ids_and_spans
                                 .iter()
@@ -1629,8 +1616,7 @@ impl<'tcx> Liveness<'_, 'tcx> {
                                 })
                                 .collect(),
                             Applicability::MachineApplicable,
-                        );
-                        err.emit();
+                        )
                     },
                 );
             } else {
@@ -1661,14 +1647,13 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             .iter()
                             .map(|(_, pat_span, _)| *pat_span)
                             .collect::<Vec<_>>(),
+                        format!("unused variable: `{}`", name),
                         |lint| {
-                            let mut err = lint.build(&format!("unused variable: `{}`", name));
-                            err.multipart_suggestion(
+                            lint.multipart_suggestion(
                                 "try ignoring the field",
                                 shorthands,
                                 Applicability::MachineApplicable,
-                            );
-                            err.emit();
+                            )
                         },
                     );
                 } else {
@@ -1684,17 +1669,16 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             .iter()
                             .map(|(_, _, ident_span)| *ident_span)
                             .collect::<Vec<_>>(),
+                        format!("unused variable: `{}`", name),
                         |lint| {
-                            let mut err = lint.build(&format!("unused variable: `{}`", name));
-                            if self.has_added_lit_match_name_span(&name, opt_body, &mut err) {
-                                err.span_label(pat.span, "unused variable");
+                            if self.has_added_lit_match_name_span(&name, opt_body, lint) {
+                                lint.span_label(pat.span, "unused variable");
                             }
-                            err.multipart_suggestion(
+                            lint.multipart_suggestion(
                                 "if this is intentional, prefix it with an underscore",
                                 non_shorthands,
                                 Applicability::MachineApplicable,
-                            );
-                            err.emit();
+                            )
                         },
                     );
                 }
@@ -1758,11 +1742,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
                 lint::builtin::UNUSED_ASSIGNMENTS,
                 hir_id,
                 spans,
-                |lint| {
-                    lint.build(&message(&name))
-                        .help("maybe it is overwritten before being read?")
-                        .emit();
-                },
+                message(&name),
+                |lint| lint.help("maybe it is overwritten before being read?"),
             )
         }
     }
diff --git a/compiler/rustc_passes/src/loops.rs b/compiler/rustc_passes/src/loops.rs
index cdda0e388..077194ec6 100644
--- a/compiler/rustc_passes/src/loops.rs
+++ b/compiler/rustc_passes/src/loops.rs
@@ -1,6 +1,5 @@
 use Context::*;
 
-use rustc_errors::{struct_span_err, Applicability};
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
@@ -13,6 +12,11 @@ use rustc_session::Session;
 use rustc_span::hygiene::DesugaringKind;
 use rustc_span::Span;
 
+use crate::errors::{
+    BreakInsideAsyncBlock, BreakInsideClosure, BreakNonLoop, ContinueLabeledBlock, OutsideLoop,
+    UnlabeledCfInWhileCondition, UnlabeledInLabeledBlock,
+};
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 enum Context {
     Normal,
@@ -90,7 +94,10 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     Ok(loop_id) => Some(loop_id),
                     Err(hir::LoopIdError::OutsideLoopScope) => None,
                     Err(hir::LoopIdError::UnlabeledCfInWhileCondition) => {
-                        self.emit_unlabled_cf_in_while_condition(e.span, "break");
+                        self.sess.emit_err(UnlabeledCfInWhileCondition {
+                            span: e.span,
+                            cf_type: "break",
+                        });
                         None
                     }
                     Err(hir::LoopIdError::UnresolvedLabel) => None,
@@ -116,69 +123,22 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     match loop_kind {
                         None | Some(hir::LoopSource::Loop) => (),
                         Some(kind) => {
-                            let mut err = struct_span_err!(
-                                self.sess,
-                                e.span,
-                                E0571,
-                                "`break` with value from a `{}` loop",
-                                kind.name()
-                            );
-                            err.span_label(
-                                e.span,
-                                "can only break with a value inside `loop` or breakable block",
+                            let suggestion = format!(
+                                "break{}",
+                                break_label
+                                    .label
+                                    .map_or_else(String::new, |l| format!(" {}", l.ident))
                             );
-                            if let Some(head) = head {
-                                err.span_label(
-                                    head,
-                                    &format!(
-                                        "you can't `break` with a value in a `{}` loop",
-                                        kind.name()
-                                    ),
-                                );
-                            }
-                            err.span_suggestion(
-                                e.span,
-                                &format!(
-                                    "use `break` on its own without a value inside this `{}` loop",
-                                    kind.name(),
-                                ),
-                                format!(
-                                    "break{}",
-                                    break_label
-                                        .label
-                                        .map_or_else(String::new, |l| format!(" {}", l.ident))
-                                ),
-                                Applicability::MaybeIncorrect,
-                            );
-                            if let (Some(label), None) = (loop_label, break_label.label) {
-                                match break_expr.kind {
-                                    hir::ExprKind::Path(hir::QPath::Resolved(
-                                        None,
-                                        hir::Path {
-                                            segments: [segment],
-                                            res: hir::def::Res::Err,
-                                            ..
-                                        },
-                                    )) if label.ident.to_string()
-                                        == format!("'{}", segment.ident) =>
-                                    {
-                                        // This error is redundant, we will have already emitted a
-                                        // suggestion to use the label when `segment` wasn't found
-                                        // (hence the `Res::Err` check).
-                                        err.delay_as_bug();
-                                    }
-                                    _ => {
-                                        err.span_suggestion(
-                                            break_expr.span,
-                                            "alternatively, you might have meant to use the \
-                                             available loop label",
-                                            label.ident,
-                                            Applicability::MaybeIncorrect,
-                                        );
-                                    }
-                                }
-                            }
-                            err.emit();
+                            self.sess.emit_err(BreakNonLoop {
+                                span: e.span,
+                                head,
+                                kind: kind.name(),
+                                suggestion,
+                                loop_label,
+                                break_label: break_label.label,
+                                break_expr_kind: &break_expr.kind,
+                                break_expr_span: break_expr.span,
+                            });
                         }
                     }
                 }
@@ -191,19 +151,17 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                 match destination.target_id {
                     Ok(loop_id) => {
                         if let Node::Block(block) = self.hir_map.find(loop_id).unwrap() {
-                            struct_span_err!(
-                                self.sess,
-                                e.span,
-                                E0696,
-                                "`continue` pointing to a labeled block"
-                            )
-                            .span_label(e.span, "labeled blocks cannot be `continue`'d")
-                            .span_label(block.span, "labeled block the `continue` points to")
-                            .emit();
+                            self.sess.emit_err(ContinueLabeledBlock {
+                                span: e.span,
+                                block_span: block.span,
+                            });
                         }
                     }
                     Err(hir::LoopIdError::UnlabeledCfInWhileCondition) => {
-                        self.emit_unlabled_cf_in_while_condition(e.span, "continue");
+                        self.sess.emit_err(UnlabeledCfInWhileCondition {
+                            span: e.span,
+                            cf_type: "continue",
+                        });
                     }
                     Err(_) => {}
                 }
@@ -226,21 +184,16 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
     }
 
     fn require_break_cx(&self, name: &str, span: Span) {
-        let err_inside_of = |article, ty, closure_span| {
-            struct_span_err!(self.sess, span, E0267, "`{}` inside of {} {}", name, article, ty)
-                .span_label(span, format!("cannot `{}` inside of {} {}", name, article, ty))
-                .span_label(closure_span, &format!("enclosing {}", ty))
-                .emit();
-        };
-
         match self.cx {
             LabeledBlock | Loop(_) => {}
-            Closure(closure_span) => err_inside_of("a", "closure", closure_span),
-            AsyncClosure(closure_span) => err_inside_of("an", "`async` block", closure_span),
+            Closure(closure_span) => {
+                self.sess.emit_err(BreakInsideClosure { span, closure_span, name });
+            }
+            AsyncClosure(closure_span) => {
+                self.sess.emit_err(BreakInsideAsyncBlock { span, closure_span, name });
+            }
             Normal | AnonConst => {
-                struct_span_err!(self.sess, span, E0268, "`{}` outside of a loop", name)
-                    .span_label(span, format!("cannot `{}` outside of a loop", name))
-                    .emit();
+                self.sess.emit_err(OutsideLoop { span, name });
             }
         }
     }
@@ -251,37 +204,13 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
         label: &Destination,
         cf_type: &str,
     ) -> bool {
-        if !span.is_desugaring(DesugaringKind::QuestionMark) && self.cx == LabeledBlock {
-            if label.label.is_none() {
-                struct_span_err!(
-                    self.sess,
-                    span,
-                    E0695,
-                    "unlabeled `{}` inside of a labeled block",
-                    cf_type
-                )
-                .span_label(
-                    span,
-                    format!(
-                        "`{}` statements that would diverge to or through \
-                                a labeled block need to bear a label",
-                        cf_type
-                    ),
-                )
-                .emit();
-                return true;
-            }
+        if !span.is_desugaring(DesugaringKind::QuestionMark)
+            && self.cx == LabeledBlock
+            && label.label.is_none()
+        {
+            self.sess.emit_err(UnlabeledInLabeledBlock { span, cf_type });
+            return true;
         }
         false
     }
-    fn emit_unlabled_cf_in_while_condition(&mut self, span: Span, cf_type: &str) {
-        struct_span_err!(
-            self.sess,
-            span,
-            E0590,
-            "`break` or `continue` with no label in the condition of a `while` loop"
-        )
-        .span_label(span, format!("unlabeled `{}` in the condition of a `while` loop", cf_type))
-        .emit();
-    }
 }
diff --git a/compiler/rustc_passes/src/naked_functions.rs b/compiler/rustc_passes/src/naked_functions.rs
index 607973446..acc54e7e1 100644
--- a/compiler/rustc_passes/src/naked_functions.rs
+++ b/compiler/rustc_passes/src/naked_functions.rs
@@ -1,7 +1,6 @@
 //! Checks validity of naked functions.
 
 use rustc_ast::InlineAsmOptions;
-use rustc_errors::{struct_span_err, Applicability};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
@@ -14,6 +13,12 @@ use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 
+use crate::errors::{
+    CannotInlineNakedFunction, NakedFunctionsAsmBlock, NakedFunctionsAsmOptions,
+    NakedFunctionsMustUseNoreturn, NakedFunctionsOperands, NoPatterns, ParamsNotAllowed,
+    UndefinedNakedFunctionAbi,
+};
+
 pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { check_mod_naked_functions, ..*providers };
 }
@@ -56,7 +61,7 @@ fn check_mod_naked_functions(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
 fn check_inline(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let attrs = tcx.get_attrs(def_id.to_def_id(), sym::inline);
     for attr in attrs {
-        tcx.sess.struct_span_err(attr.span, "naked functions cannot be inlined").emit();
+        tcx.sess.emit_err(CannotInlineNakedFunction { span: attr.span });
     }
 }
 
@@ -65,9 +70,12 @@ fn check_abi(tcx: TyCtxt<'_>, def_id: LocalDefId, abi: Abi) {
     if abi == Abi::Rust {
         let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
         let span = tcx.def_span(def_id);
-        tcx.struct_span_lint_hir(UNDEFINED_NAKED_FUNCTION_ABI, hir_id, span, |lint| {
-            lint.build("Rust ABI is unsupported in naked functions").emit();
-        });
+        tcx.emit_spanned_lint(
+            UNDEFINED_NAKED_FUNCTION_ABI,
+            hir_id,
+            span,
+            UndefinedNakedFunctionAbi,
+        );
     }
 }
 
@@ -78,12 +86,7 @@ fn check_no_patterns(tcx: TyCtxt<'_>, params: &[hir::Param<'_>]) {
             hir::PatKind::Wild
             | hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, _, None) => {}
             _ => {
-                tcx.sess
-                    .struct_span_err(
-                        param.pat.span,
-                        "patterns not allowed in naked function parameters",
-                    )
-                    .emit();
+                tcx.sess.emit_err(NoPatterns { span: param.pat.span });
             }
         }
     }
@@ -113,14 +116,7 @@ impl<'tcx> Visitor<'tcx> for CheckParameters<'tcx> {
         )) = expr.kind
         {
             if self.params.contains(var_hir_id) {
-                self.tcx
-                    .sess
-                    .struct_span_err(
-                        expr.span,
-                        "referencing function parameters is not allowed in naked functions",
-                    )
-                    .help("follow the calling convention in asm block to use parameters")
-                    .emit();
+                self.tcx.sess.emit_err(ParamsNotAllowed { span: expr.span });
                 return;
             }
         }
@@ -135,26 +131,21 @@ fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &'tcx hir::Body<
     if let [(ItemKind::Asm | ItemKind::Err, _)] = this.items[..] {
         // Ok.
     } else {
-        let mut diag = struct_span_err!(
-            tcx.sess,
-            tcx.def_span(def_id),
-            E0787,
-            "naked functions must contain a single asm block"
-        );
-
         let mut must_show_error = false;
         let mut has_asm = false;
         let mut has_err = false;
+        let mut multiple_asms = vec![];
+        let mut non_asms = vec![];
         for &(kind, span) in &this.items {
             match kind {
                 ItemKind::Asm if has_asm => {
                     must_show_error = true;
-                    diag.span_label(span, "multiple asm blocks are unsupported in naked functions");
+                    multiple_asms.push(span);
                 }
                 ItemKind::Asm => has_asm = true,
                 ItemKind::NonAsm => {
                     must_show_error = true;
-                    diag.span_label(span, "non-asm is unsupported in naked functions");
+                    non_asms.push(span);
                 }
                 ItemKind::Err => has_err = true,
             }
@@ -164,9 +155,11 @@ fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &'tcx hir::Body<
         // errors, then don't show an additional error. This allows for appending/prepending
         // `compile_error!("...")` statements and reduces error noise.
         if must_show_error || !has_err {
-            diag.emit();
-        } else {
-            diag.cancel();
+            tcx.sess.emit_err(NakedFunctionsAsmBlock {
+                span: tcx.def_span(def_id),
+                multiple_asms,
+                non_asms,
+            });
         }
     }
 }
@@ -247,13 +240,7 @@ impl<'tcx> CheckInlineAssembly<'tcx> {
             })
             .collect();
         if !unsupported_operands.is_empty() {
-            struct_span_err!(
-                self.tcx.sess,
-                unsupported_operands,
-                E0787,
-                "only `const` and `sym` operands are supported in naked functions",
-            )
-            .emit();
+            self.tcx.sess.emit_err(NakedFunctionsOperands { unsupported_operands });
         }
 
         let unsupported_options: Vec<&'static str> = [
@@ -269,14 +256,10 @@ impl<'tcx> CheckInlineAssembly<'tcx> {
         .collect();
 
         if !unsupported_options.is_empty() {
-            struct_span_err!(
-                self.tcx.sess,
+            self.tcx.sess.emit_err(NakedFunctionsAsmOptions {
                 span,
-                E0787,
-                "asm options unsupported in naked functions: {}",
-                unsupported_options.join(", ")
-            )
-            .emit();
+                unsupported_options: unsupported_options.join(", "),
+            });
         }
 
         if !asm.options.contains(InlineAsmOptions::NORETURN) {
@@ -286,20 +269,7 @@ impl<'tcx> CheckInlineAssembly<'tcx> {
                 .map_or_else(|| asm.template_strs.last().unwrap().2, |op| op.1)
                 .shrink_to_hi();
 
-            struct_span_err!(
-                self.tcx.sess,
-                span,
-                E0787,
-                "asm in naked functions must use `noreturn` option"
-            )
-            .span_suggestion(
-                last_span,
-                "consider specifying that the asm block is responsible \
-                for returning from the function",
-                ", options(noreturn)",
-                Applicability::MachineApplicable,
-            )
-            .emit();
+            self.tcx.sess.emit_err(NakedFunctionsMustUseNoreturn { span, last_span });
         }
     }
 }
diff --git a/compiler/rustc_passes/src/reachable.rs b/compiler/rustc_passes/src/reachable.rs
index f7e3fac6b..50070869a 100644
--- a/compiler/rustc_passes/src/reachable.rs
+++ b/compiler/rustc_passes/src/reachable.rs
@@ -12,7 +12,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::Node;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
-use rustc_middle::middle::privacy;
+use rustc_middle::middle::privacy::{self, Level};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
 use rustc_session::config::CrateType;
@@ -29,7 +29,7 @@ fn item_might_be_inlined(tcx: TyCtxt<'_>, item: &hir::Item<'_>, attrs: &CodegenF
     match item.kind {
         hir::ItemKind::Fn(ref sig, ..) if sig.header.is_const() => true,
         hir::ItemKind::Impl { .. } | hir::ItemKind::Fn(..) => {
-            let generics = tcx.generics_of(item.def_id);
+            let generics = tcx.generics_of(item.owner_id);
             generics.requires_monomorphization(tcx)
         }
         _ => false,
@@ -42,7 +42,7 @@ fn method_might_be_inlined(
     impl_src: LocalDefId,
 ) -> bool {
     let codegen_fn_attrs = tcx.codegen_fn_attrs(impl_item.hir_id().owner.to_def_id());
-    let generics = tcx.generics_of(impl_item.def_id);
+    let generics = tcx.generics_of(impl_item.owner_id);
     if codegen_fn_attrs.requests_inline() || generics.requires_monomorphization(tcx) {
         return true;
     }
@@ -116,6 +116,17 @@ impl<'tcx> Visitor<'tcx> for ReachableContext<'tcx> {
 
         intravisit::walk_expr(self, expr)
     }
+
+    fn visit_inline_asm(&mut self, asm: &'tcx hir::InlineAsm<'tcx>, id: hir::HirId) {
+        for (op, _) in asm.operands {
+            if let hir::InlineAsmOperand::SymStatic { def_id, .. } = op {
+                if let Some(def_id) = def_id.as_local() {
+                    self.reachable_symbols.insert(def_id);
+                }
+            }
+        }
+        intravisit::walk_inline_asm(self, asm, id);
+    }
 }
 
 impl<'tcx> ReachableContext<'tcx> {
@@ -153,9 +164,9 @@ impl<'tcx> ReachableContext<'tcx> {
                 hir::ImplItemKind::Fn(..) => {
                     let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
                     let impl_did = self.tcx.hir().get_parent_item(hir_id);
-                    method_might_be_inlined(self.tcx, impl_item, impl_did)
+                    method_might_be_inlined(self.tcx, impl_item, impl_did.def_id)
                 }
-                hir::ImplItemKind::TyAlias(_) => false,
+                hir::ImplItemKind::Type(_) => false,
             },
             Some(_) => false,
             None => false, // This will happen for default methods.
@@ -216,7 +227,7 @@ impl<'tcx> ReachableContext<'tcx> {
                         if item_might_be_inlined(
                             self.tcx,
                             &item,
-                            self.tcx.codegen_fn_attrs(item.def_id),
+                            self.tcx.codegen_fn_attrs(item.owner_id),
                         ) {
                             self.visit_nested_body(body);
                         }
@@ -271,7 +282,7 @@ impl<'tcx> ReachableContext<'tcx> {
                         self.visit_nested_body(body)
                     }
                 }
-                hir::ImplItemKind::TyAlias(_) => {}
+                hir::ImplItemKind::Type(_) => {}
             },
             Node::Expr(&hir::Expr {
                 kind: hir::ExprKind::Closure(&hir::Closure { body, .. }),
@@ -303,13 +314,13 @@ fn check_item<'tcx>(
     tcx: TyCtxt<'tcx>,
     id: hir::ItemId,
     worklist: &mut Vec<LocalDefId>,
-    access_levels: &privacy::AccessLevels,
+    effective_visibilities: &privacy::EffectiveVisibilities,
 ) {
-    if has_custom_linkage(tcx, id.def_id) {
-        worklist.push(id.def_id);
+    if has_custom_linkage(tcx, id.owner_id.def_id) {
+        worklist.push(id.owner_id.def_id);
     }
 
-    if !matches!(tcx.def_kind(id.def_id), DefKind::Impl) {
+    if !matches!(tcx.def_kind(id.owner_id), DefKind::Impl) {
         return;
     }
 
@@ -318,8 +329,8 @@ fn check_item<'tcx>(
     if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(ref trait_ref), ref items, .. }) =
         item.kind
     {
-        if !access_levels.is_reachable(item.def_id) {
-            worklist.extend(items.iter().map(|ii_ref| ii_ref.id.def_id));
+        if !effective_visibilities.is_reachable(item.owner_id.def_id) {
+            worklist.extend(items.iter().map(|ii_ref| ii_ref.id.owner_id.def_id));
 
             let Res::Def(DefKind::Trait, trait_def_id) = trait_ref.path.res else {
                 unreachable!();
@@ -354,7 +365,7 @@ fn has_custom_linkage<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool {
 }
 
 fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> FxHashSet<LocalDefId> {
-    let access_levels = &tcx.privacy_access_levels(());
+    let effective_visibilities = &tcx.effective_visibilities(());
 
     let any_library =
         tcx.sess.crate_types().iter().any(|ty| {
@@ -373,7 +384,13 @@ fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> FxHashSet<LocalDefId> {
     //         If other crates link to us, they're going to expect to be able to
     //         use the lang items, so we need to be sure to mark them as
     //         exported.
-    reachable_context.worklist.extend(access_levels.map.keys());
+    reachable_context.worklist = effective_visibilities
+        .iter()
+        .filter_map(|(&id, effective_vis)| {
+            effective_vis.is_public_at_level(Level::ReachableThroughImplTrait).then_some(id)
+        })
+        .collect::<Vec<_>>();
+
     for item in tcx.lang_items().items().iter() {
         if let Some(def_id) = *item {
             if let Some(def_id) = def_id.as_local() {
@@ -393,12 +410,12 @@ fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> FxHashSet<LocalDefId> {
         let crate_items = tcx.hir_crate_items(());
 
         for id in crate_items.items() {
-            check_item(tcx, id, &mut reachable_context.worklist, access_levels);
+            check_item(tcx, id, &mut reachable_context.worklist, effective_visibilities);
         }
 
         for id in crate_items.impl_items() {
-            if has_custom_linkage(tcx, id.def_id) {
-                reachable_context.worklist.push(id.def_id);
+            if has_custom_linkage(tcx, id.owner_id.def_id) {
+                reachable_context.worklist.push(id.owner_id.def_id);
             }
         }
     }
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index 9ba127609..78afa2f25 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -1,12 +1,18 @@
 //! A pass that annotates every item and method with its stability level,
 //! propagating default levels lexically from parent to children ast nodes.
 
+use crate::errors::{
+    self, CannotStabilizeDeprecated, DeprecatedAttribute, DuplicateFeatureErr,
+    FeatureOnlyOnNightly, ImpliedFeatureNotExist, InvalidDeprecationVersion, InvalidStability,
+    MissingConstErr, MissingConstStabAttr, MissingStabilityAttr, TraitImplConstStable,
+    UnknownFeature, UselessStability,
+};
 use rustc_attr::{
     self as attr, rust_version_symbol, ConstStability, Stability, StabilityLevel, Unstable,
     UnstableReason, VERSION_PLACEHOLDER,
 };
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
-use rustc_errors::{struct_span_err, Applicability};
+use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
@@ -14,12 +20,11 @@ use rustc_hir::hir_id::CRATE_HIR_ID;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{FieldDef, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
 use rustc_middle::hir::nested_filter;
-use rustc_middle::middle::privacy::AccessLevels;
+use rustc_middle::middle::privacy::EffectiveVisibilities;
 use rustc_middle::middle::stability::{AllowUnstable, DeprecationEntry, Index};
 use rustc_middle::ty::{query::Providers, TyCtxt};
 use rustc_session::lint;
 use rustc_session::lint::builtin::{INEFFECTIVE_UNSTABLE_TRAIT_IMPL, USELESS_DEPRECATED};
-use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
@@ -122,16 +127,12 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
 
             if kind == AnnotationKind::Prohibited || kind == AnnotationKind::DeprecationProhibited {
                 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
-                self.tcx.struct_span_lint_hir(USELESS_DEPRECATED, hir_id, *span, |lint| {
-                    lint.build("this `#[deprecated]` annotation has no effect")
-                        .span_suggestion_short(
-                            *span,
-                            "remove the unnecessary deprecation attribute",
-                            "",
-                            rustc_errors::Applicability::MachineApplicable,
-                        )
-                        .emit();
-                });
+                self.tcx.emit_spanned_lint(
+                    USELESS_DEPRECATED,
+                    hir_id,
+                    *span,
+                    errors::DeprecatedAnnotationHasNoEffect { span: *span },
+                );
             }
 
             // `Deprecation` is just two pointers, no need to intern it
@@ -182,7 +183,9 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
                 if !self.in_trait_impl
                     || (self.in_trait_impl && !self.tcx.is_const_fn_raw(def_id.to_def_id()))
                 {
-                    missing_const_err(&self.tcx.sess, fn_sig.span, const_span);
+                    self.tcx
+                        .sess
+                        .emit_err(MissingConstErr { fn_sig_span: fn_sig.span, const_span });
                 }
             }
         }
@@ -200,14 +203,7 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
 
         if let Some((rustc_attr::Deprecation { is_since_rustc_version: true, .. }, span)) = &depr {
             if stab.is_none() {
-                struct_span_err!(
-                    self.tcx.sess,
-                    *span,
-                    E0549,
-                    "deprecated attribute must be paired with \
-                    either stable or unstable attribute"
-                )
-                .emit();
+                self.tcx.sess.emit_err(DeprecatedAttribute { span: *span });
             }
         }
 
@@ -223,10 +219,7 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
             if kind == AnnotationKind::Prohibited
                 || (kind == AnnotationKind::Container && stab.level.is_stable() && is_deprecated)
             {
-                self.tcx.sess.struct_span_err(span,"this stability annotation is useless")
-                    .span_label(span, "useless stability annotation")
-                    .span_label(item_sp, "the stability attribute annotates this item")
-                    .emit();
+                self.tcx.sess.emit_err(UselessStability { span, item_sp });
             }
 
             debug!("annotate: found {:?}", stab);
@@ -242,19 +235,15 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
                 {
                     match stab_v.parse::<u64>() {
                         Err(_) => {
-                            self.tcx.sess.struct_span_err(span, "invalid stability version found")
-                                .span_label(span, "invalid stability version")
-                                .span_label(item_sp, "the stability attribute annotates this item")
-                                .emit();
+                            self.tcx.sess.emit_err(InvalidStability { span, item_sp });
                             break;
                         }
                         Ok(stab_vp) => match dep_v.parse::<u64>() {
                             Ok(dep_vp) => match dep_vp.cmp(&stab_vp) {
                                 Ordering::Less => {
-                                    self.tcx.sess.struct_span_err(span, "an API can't be stabilized after it is deprecated")
-                                        .span_label(span, "invalid version")
-                                        .span_label(item_sp, "the stability attribute annotates this item")
-                                        .emit();
+                                    self.tcx
+                                        .sess
+                                        .emit_err(CannotStabilizeDeprecated { span, item_sp });
                                     break;
                                 }
                                 Ordering::Equal => continue,
@@ -262,10 +251,9 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
                             },
                             Err(_) => {
                                 if dep_v != "TBD" {
-                                    self.tcx.sess.struct_span_err(span, "invalid deprecation version found")
-                                        .span_label(span, "invalid deprecation version")
-                                        .span_label(item_sp, "the stability attribute annotates this item")
-                                        .emit();
+                                    self.tcx
+                                        .sess
+                                        .emit_err(InvalidDeprecationVersion { span, item_sp });
                                 }
                                 break;
                             }
@@ -274,7 +262,9 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
                 }
             }
 
-            if let Stability { level: Unstable { implied_by: Some(implied_by), .. }, feature } = stab {
+            if let Stability { level: Unstable { implied_by: Some(implied_by), .. }, feature } =
+                stab
+            {
                 self.index.implications.insert(implied_by, feature);
             }
 
@@ -388,7 +378,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
         }
 
         self.annotate(
-            i.def_id,
+            i.owner_id.def_id,
             i.span,
             fn_sig,
             kind,
@@ -407,7 +397,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
         };
 
         self.annotate(
-            ti.def_id,
+            ti.owner_id.def_id,
             ti.span,
             fn_sig,
             AnnotationKind::Required,
@@ -430,7 +420,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
         };
 
         self.annotate(
-            ii.def_id,
+            ii.owner_id.def_id,
             ii.span,
             fn_sig,
             kind,
@@ -488,7 +478,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
 
     fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem<'tcx>) {
         self.annotate(
-            i.def_id,
+            i.owner_id.def_id,
             i.span,
             None,
             AnnotationKind::Required,
@@ -526,15 +516,18 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
 
 struct MissingStabilityAnnotations<'tcx> {
     tcx: TyCtxt<'tcx>,
-    access_levels: &'tcx AccessLevels,
+    effective_visibilities: &'tcx EffectiveVisibilities,
 }
 
 impl<'tcx> MissingStabilityAnnotations<'tcx> {
     fn check_missing_stability(&self, def_id: LocalDefId, span: Span) {
         let stab = self.tcx.stability().local_stability(def_id);
-        if !self.tcx.sess.opts.test && stab.is_none() && self.access_levels.is_reachable(def_id) {
+        if !self.tcx.sess.opts.test
+            && stab.is_none()
+            && self.effective_visibilities.is_reachable(def_id)
+        {
             let descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
-            self.tcx.sess.span_err(span, &format!("{} has missing stability attribute", descr));
+            self.tcx.sess.emit_err(MissingStabilityAttr { span, descr });
         }
     }
 
@@ -550,11 +543,11 @@ impl<'tcx> MissingStabilityAnnotations<'tcx> {
             .lookup_stability(def_id)
             .map_or(false, |stability| stability.level.is_stable());
         let missing_const_stability_attribute = self.tcx.lookup_const_stability(def_id).is_none();
-        let is_reachable = self.access_levels.is_reachable(def_id);
+        let is_reachable = self.effective_visibilities.is_reachable(def_id);
 
         if is_const && is_stable && missing_const_stability_attribute && is_reachable {
             let descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
-            self.tcx.sess.span_err(span, &format!("{descr} has missing const stability attribute"));
+            self.tcx.sess.emit_err(MissingConstStabAttr { span, descr });
         }
     }
 }
@@ -576,25 +569,25 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
             hir::ItemKind::Impl(hir::Impl { of_trait: None, .. })
                 | hir::ItemKind::ForeignMod { .. }
         ) {
-            self.check_missing_stability(i.def_id, i.span);
+            self.check_missing_stability(i.owner_id.def_id, i.span);
         }
 
         // Ensure stable `const fn` have a const stability attribute.
-        self.check_missing_const_stability(i.def_id, i.span);
+        self.check_missing_const_stability(i.owner_id.def_id, i.span);
 
         intravisit::walk_item(self, i)
     }
 
     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) {
-        self.check_missing_stability(ti.def_id, ti.span);
+        self.check_missing_stability(ti.owner_id.def_id, ti.span);
         intravisit::walk_trait_item(self, ti);
     }
 
     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) {
         let impl_def_id = self.tcx.hir().get_parent_item(ii.hir_id());
         if self.tcx.impl_trait_ref(impl_def_id).is_none() {
-            self.check_missing_stability(ii.def_id, ii.span);
-            self.check_missing_const_stability(ii.def_id, ii.span);
+            self.check_missing_stability(ii.owner_id.def_id, ii.span);
+            self.check_missing_const_stability(ii.owner_id.def_id, ii.span);
         }
         intravisit::walk_impl_item(self, ii);
     }
@@ -613,7 +606,7 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
     }
 
     fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem<'tcx>) {
-        self.check_missing_stability(i.def_id, i.span);
+        self.check_missing_stability(i.owner_id.def_id, i.span);
         intravisit::walk_foreign_item(self, i);
     }
     // Note that we don't need to `check_missing_stability` for default generic parameters,
@@ -719,7 +712,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                     return;
                 }
 
-                let Some(cnum) = self.tcx.extern_mod_stmt_cnum(item.def_id) else {
+                let Some(cnum) = self.tcx.extern_mod_stmt_cnum(item.owner_id.def_id) else {
                     return;
                 };
                 let def_id = cnum.as_def_id();
@@ -755,10 +748,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                                 INEFFECTIVE_UNSTABLE_TRAIT_IMPL,
                                 item.hir_id(),
                                 span,
-                                |lint| {lint
-                                    .build("an `#[unstable]` annotation here has no effect")
-                                    .note("see issue #55436 <https://github.com/rust-lang/rust/issues/55436> for more information")
-                                    .emit();}
+                                "an `#[unstable]` annotation here has no effect",
+                                |lint| lint.note("see issue #55436 <https://github.com/rust-lang/rust/issues/55436> for more information")
                             );
                         }
                     }
@@ -769,16 +760,12 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                         && *constness == hir::Constness::Const
                         && const_stab.map_or(false, |(stab, _)| stab.is_const_stable())
                     {
-                        self.tcx
-                            .sess
-                            .struct_span_err(item.span, "trait implementations cannot be const stable yet")
-                            .note("see issue #67792 <https://github.com/rust-lang/rust/issues/67792> for more information")
-                            .emit();
+                        self.tcx.sess.emit_err(TraitImplConstStable { span: item.span });
                     }
                 }
 
                 for impl_item_ref in *items {
-                    let impl_item = self.tcx.associated_item(impl_item_ref.id.def_id);
+                    let impl_item = self.tcx.associated_item(impl_item_ref.id.owner_id);
 
                     if let Some(def_id) = impl_item.trait_item_def_id {
                         // Pass `None` to skip deprecation warnings.
@@ -872,7 +859,7 @@ fn is_unstable_reexport<'tcx>(tcx: TyCtxt<'tcx>, id: hir::HirId) -> bool {
     }
 
     // If this is a path that isn't a use, we don't need to do anything special
-    if !matches!(tcx.hir().item(hir::ItemId { def_id }).kind, ItemKind::Use(..)) {
+    if !matches!(tcx.hir().expect_item(def_id).kind, ItemKind::Use(..)) {
         return false;
     }
 
@@ -907,8 +894,25 @@ impl<'tcx> Visitor<'tcx> for CheckTraitImplStable<'tcx> {
         if let TyKind::Never = t.kind {
             self.fully_stable = false;
         }
+        if let TyKind::BareFn(f) = t.kind {
+            if rustc_target::spec::abi::is_stable(f.abi.name()).is_err() {
+                self.fully_stable = false;
+            }
+        }
         intravisit::walk_ty(self, t)
     }
+
+    fn visit_fn_decl(&mut self, fd: &'tcx hir::FnDecl<'tcx>) {
+        for ty in fd.inputs {
+            self.visit_ty(ty)
+        }
+        if let hir::FnRetTy::Return(output_ty) = fd.output {
+            match output_ty.kind {
+                TyKind::Never => {} // `-> !` is stable
+                _ => self.visit_ty(output_ty),
+            }
+        }
+    }
 }
 
 /// Given the list of enabled features that were not language features (i.e., that
@@ -918,8 +922,8 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
     let is_staged_api =
         tcx.sess.opts.unstable_opts.force_unstable_if_unmarked || tcx.features().staged_api;
     if is_staged_api {
-        let access_levels = &tcx.privacy_access_levels(());
-        let mut missing = MissingStabilityAnnotations { tcx, access_levels };
+        let effective_visibilities = &tcx.effective_visibilities(());
+        let mut missing = MissingStabilityAnnotations { tcx, effective_visibilities };
         missing.check_missing_stability(CRATE_DEF_ID, tcx.hir().span(CRATE_HIR_ID));
         tcx.hir().walk_toplevel_module(&mut missing);
         tcx.hir().visit_all_item_likes_in_crate(&mut missing);
@@ -934,7 +938,7 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
         }
         if !lang_features.insert(feature) {
             // Warn if the user enables a lang feature multiple times.
-            duplicate_feature_err(tcx.sess, span, feature);
+            tcx.sess.emit_err(DuplicateFeatureErr { span, feature });
         }
     }
 
@@ -942,18 +946,14 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
     let mut remaining_lib_features = FxIndexMap::default();
     for (feature, span) in declared_lib_features {
         if !tcx.sess.opts.unstable_features.is_nightly_build() {
-            struct_span_err!(
-                tcx.sess,
-                *span,
-                E0554,
-                "`#![feature]` may not be used on the {} release channel",
-                env!("CFG_RELEASE_CHANNEL")
-            )
-            .emit();
+            tcx.sess.emit_err(FeatureOnlyOnNightly {
+                span: *span,
+                release_channel: env!("CFG_RELEASE_CHANNEL"),
+            });
         }
         if remaining_lib_features.contains_key(&feature) {
             // Warn if the user enables a lib feature multiple times.
-            duplicate_feature_err(tcx.sess, *span, *feature);
+            tcx.sess.emit_err(DuplicateFeatureErr { span: *span, feature: *feature });
         }
         remaining_lib_features.insert(feature, *span);
     }
@@ -1054,23 +1054,18 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
     }
 
     for (feature, span) in remaining_lib_features {
-        struct_span_err!(tcx.sess, span, E0635, "unknown feature `{}`", feature).emit();
+        tcx.sess.emit_err(UnknownFeature { span, feature: *feature });
     }
 
     for (implied_by, feature) in remaining_implications {
         let local_defined_features = tcx.lib_features(());
-        let span = local_defined_features
+        let span = *local_defined_features
             .stable
             .get(&feature)
             .map(|(_, span)| span)
             .or_else(|| local_defined_features.unstable.get(&feature))
             .expect("feature that implied another does not exist");
-        tcx.sess
-            .struct_span_err(
-                *span,
-                format!("feature `{implied_by}` implying `{feature}` does not exist"),
-            )
-            .emit();
+        tcx.sess.emit_err(ImpliedFeatureNotExist { span, feature, implied_by });
     }
 
     // FIXME(#44232): the `used_features` table no longer exists, so we
@@ -1084,27 +1079,31 @@ fn unnecessary_partially_stable_feature_lint(
     implies: Symbol,
     since: Symbol,
 ) {
-    tcx.struct_span_lint_hir(lint::builtin::STABLE_FEATURES, hir::CRATE_HIR_ID, span, |lint| {
-        lint.build(&format!(
+    tcx.struct_span_lint_hir(
+        lint::builtin::STABLE_FEATURES,
+        hir::CRATE_HIR_ID,
+        span,
+        format!(
             "the feature `{feature}` has been partially stabilized since {since} and is succeeded \
              by the feature `{implies}`"
-        ))
-        .span_suggestion(
-            span,
-            &format!(
+        ),
+        |lint| {
+            lint.span_suggestion(
+                span,
+                &format!(
                 "if you are using features which are still unstable, change to using `{implies}`"
             ),
-            implies,
-            Applicability::MaybeIncorrect,
-        )
-        .span_suggestion(
-            tcx.sess.source_map().span_extend_to_line(span),
-            "if you are using features which are now stable, remove this line",
-            "",
-            Applicability::MaybeIncorrect,
-        )
-        .emit();
-    });
+                implies,
+                Applicability::MaybeIncorrect,
+            )
+            .span_suggestion(
+                tcx.sess.source_map().span_extend_to_line(span),
+                "if you are using features which are now stable, remove this line",
+                "",
+                Applicability::MaybeIncorrect,
+            )
+        },
+    );
 }
 
 fn unnecessary_stable_feature_lint(
@@ -1116,28 +1115,7 @@ fn unnecessary_stable_feature_lint(
     if since.as_str() == VERSION_PLACEHOLDER {
         since = rust_version_symbol();
     }
-    tcx.struct_span_lint_hir(lint::builtin::STABLE_FEATURES, hir::CRATE_HIR_ID, span, |lint| {
-        lint.build(&format!(
-            "the feature `{feature}` has been stable since {since} and no longer requires an \
-             attribute to enable",
-        ))
-        .emit();
+    tcx.struct_span_lint_hir(lint::builtin::STABLE_FEATURES, hir::CRATE_HIR_ID, span, format!("the feature `{feature}` has been stable since {since} and no longer requires an attribute to enable"), |lint| {
+        lint
     });
 }
-
-fn duplicate_feature_err(sess: &Session, span: Span, feature: Symbol) {
-    struct_span_err!(sess, span, E0636, "the feature `{}` has already been declared", feature)
-        .emit();
-}
-
-fn missing_const_err(session: &Session, fn_sig_span: Span, const_span: Span) {
-    const ERROR_MSG: &'static str = "attributes `#[rustc_const_unstable]` \
-         and `#[rustc_const_stable]` require \
-         the function or method to be `const`";
-
-    session
-        .struct_span_err(fn_sig_span, ERROR_MSG)
-        .span_help(fn_sig_span, "make the function or method const")
-        .span_label(const_span, "attribute specified here")
-        .emit();
-}
diff --git a/compiler/rustc_passes/src/weak_lang_items.rs b/compiler/rustc_passes/src/weak_lang_items.rs
index c48b4ecf8..959ee600c 100644
--- a/compiler/rustc_passes/src/weak_lang_items.rs
+++ b/compiler/rustc_passes/src/weak_lang_items.rs
@@ -1,13 +1,17 @@
 //! Validity checking for weak lang items
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_errors::struct_span_err;
 use rustc_hir::lang_items::{self, LangItem};
 use rustc_hir::weak_lang_items::WEAK_ITEMS_REFS;
 use rustc_middle::middle::lang_items::required;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::CrateType;
 
+use crate::errors::{
+    AllocFuncRequired, MissingAllocErrorHandler, MissingLangItem, MissingPanicHandler,
+    UnknownExternLangItem,
+};
+
 /// Checks the crate for usage of weak lang items, returning a vector of all the
 /// language items required by this crate, but not defined yet.
 pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>, items: &mut lang_items::LanguageItems) {
@@ -30,15 +34,8 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>, items: &mut lang_items::LanguageItem
                     items.missing.push(item);
                 }
             } else {
-                let span = tcx.def_span(id.def_id);
-                struct_span_err!(
-                    tcx.sess,
-                    span,
-                    E0264,
-                    "unknown external lang item: `{}`",
-                    lang_item
-                )
-                .emit();
+                let span = tcx.def_span(id.owner_id);
+                tcx.sess.emit_err(UnknownExternLangItem { span, lang_item });
             }
         }
     }
@@ -71,20 +68,14 @@ fn verify<'tcx>(tcx: TyCtxt<'tcx>, items: &lang_items::LanguageItems) {
     for (name, &item) in WEAK_ITEMS_REFS.iter() {
         if missing.contains(&item) && required(tcx, item) && items.require(item).is_err() {
             if item == LangItem::PanicImpl {
-                tcx.sess.err("`#[panic_handler]` function required, but not found");
+                tcx.sess.emit_err(MissingPanicHandler);
             } else if item == LangItem::Oom {
                 if !tcx.features().default_alloc_error_handler {
-                    tcx.sess.err("`#[alloc_error_handler]` function required, but not found");
-                    tcx.sess.note_without_error("use `#![feature(default_alloc_error_handler)]` for a default error handler");
+                    tcx.sess.emit_err(AllocFuncRequired);
+                    tcx.sess.emit_note(MissingAllocErrorHandler);
                 }
             } else {
-                tcx
-                    .sess
-                    .diagnostic()
-                    .struct_err(&format!("language item required, but not found: `{}`", name))
-                    .note(&format!("this can occur when a binary crate with `#![no_std]` is compiled for a target where `{}` is defined in the standard library", name))
-                    .help(&format!("you may be able to compile for a target that doesn't need `{}`, specify a target with `--target` or in `.cargo/config`", name))
-                    .emit();
+                tcx.sess.emit_err(MissingLangItem { name: *name });
             }
         }
     }