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-rw-r--r--compiler/rustc_codegen_ssa/src/codegen_attrs.rs2
-rw-r--r--compiler/rustc_errors/src/diagnostic.rs2
-rw-r--r--compiler/rustc_hir_analysis/src/check/check.rs18
-rw-r--r--compiler/rustc_hir_analysis/src/check/intrinsicck.rs2
-rw-r--r--compiler/rustc_hir_analysis/src/check_unused.rs13
-rw-r--r--compiler/rustc_hir_analysis/src/collect/generics_of.rs5
-rw-r--r--compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs5
-rw-r--r--compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs4
-rw-r--r--compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs45
-rw-r--r--compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs20
-rw-r--r--compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs130
-rw-r--r--compiler/rustc_hir_typeck/src/method/probe.rs85
-rw-r--r--compiler/rustc_hir_typeck/src/pat.rs19
-rw-r--r--compiler/rustc_hir_typeck/src/upvar.rs3
-rw-r--r--compiler/rustc_lint/src/context.rs31
-rw-r--r--compiler/rustc_lint/src/impl_trait_overcaptures.rs5
-rw-r--r--compiler/rustc_lint/src/levels.rs42
-rw-r--r--compiler/rustc_lint/src/lints.rs56
-rw-r--r--compiler/rustc_lint/src/non_fmt_panic.rs3
-rw-r--r--compiler/rustc_macros/src/diagnostics/diagnostic.rs32
-rw-r--r--compiler/rustc_middle/src/lint.rs10
-rw-r--r--compiler/rustc_middle/src/middle/stability.rs21
-rw-r--r--compiler/rustc_middle/src/mir/interpret/queries.rs3
-rw-r--r--compiler/rustc_middle/src/ty/context.rs19
-rw-r--r--compiler/rustc_mir_transform/src/errors.rs22
-rw-r--r--compiler/rustc_pattern_analysis/src/lints.rs1
-rw-r--r--compiler/rustc_trait_selection/src/traits/object_safety.rs63
-rw-r--r--compiler/rustc_trait_selection/src/traits/specialize/mod.rs21
28 files changed, 288 insertions, 394 deletions
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 9bf055b1739..304c604100a 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -564,8 +564,8 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                     lint::builtin::INLINE_NO_SANITIZE,
                     hir_id,
                     no_sanitize_span,
-                    "`no_sanitize` will have no effect after inlining",
                     |lint| {
+                        lint.primary_message("`no_sanitize` will have no effect after inlining");
                         lint.span_note(inline_span, "inlining requested here");
                     },
                 )
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 18bb71bd99f..34b569c4206 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -200,8 +200,6 @@ pub trait SubdiagMessageOp<G: EmissionGuarantee> =
 pub trait LintDiagnostic<'a, G: EmissionGuarantee> {
     /// Decorate and emit a lint.
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, G>);
-
-    fn msg(&self) -> DiagMessage;
 }
 
 #[derive(Clone, Debug, Encodable, Decodable)]
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index b5c06751405..b46b1d5a26b 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -46,13 +46,9 @@ pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
             .emit();
         }
         None => {
-            tcx.node_span_lint(
-                UNSUPPORTED_CALLING_CONVENTIONS,
-                hir_id,
-                span,
-                "use of calling convention not supported on this target",
-                |_| {},
-            );
+            tcx.node_span_lint(UNSUPPORTED_CALLING_CONVENTIONS, hir_id, span, |lint| {
+                lint.primary_message("use of calling convention not supported on this target");
+            });
         }
     }
 
@@ -243,8 +239,8 @@ fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             UNINHABITED_STATIC,
             tcx.local_def_id_to_hir_id(def_id),
             span,
-            "static of uninhabited type",
             |lint| {
+                lint.primary_message("static of uninhabited type");
                 lint
                 .note("uninhabited statics cannot be initialized, and any access would be an immediate error");
             },
@@ -1315,9 +1311,11 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>)
                     REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS,
                     tcx.local_def_id_to_hir_id(adt.did().expect_local()),
                     span,
-                    "zero-sized fields in `repr(transparent)` cannot \
-                    contain external non-exhaustive types",
                     |lint| {
+                        lint.primary_message(
+                            "zero-sized fields in `repr(transparent)` cannot \
+                             contain external non-exhaustive types",
+                        );
                         let note = if non_exhaustive {
                             "is marked with `#[non_exhaustive]`"
                         } else {
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
index b09de1a4a09..2672614a895 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
@@ -281,8 +281,8 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
                     lint::builtin::ASM_SUB_REGISTER,
                     expr.hir_id,
                     spans,
-                    "formatting may not be suitable for sub-register argument",
                     |lint| {
+                        lint.primary_message("formatting may not be suitable for sub-register argument");
                         lint.span_label(expr.span, "for this argument");
                         lint.help(format!(
                             "use `{{{idx}:{suggested_modifier}}}` to have the register formatted as `{suggested_result}` (for {suggested_size}-bit values)",
diff --git a/compiler/rustc_hir_analysis/src/check_unused.rs b/compiler/rustc_hir_analysis/src/check_unused.rs
index aa5db4f6aa7..ed23dc2a827 100644
--- a/compiler/rustc_hir_analysis/src/check_unused.rs
+++ b/compiler/rustc_hir_analysis/src/check_unused.rs
@@ -35,11 +35,12 @@ fn check_unused_traits(tcx: TyCtxt<'_>, (): ()) {
             continue;
         }
         let (path, _) = item.expect_use();
-        let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) {
-            format!("unused import: `{snippet}`")
-        } else {
-            "unused import".to_owned()
-        };
-        tcx.node_span_lint(lint::builtin::UNUSED_IMPORTS, item.hir_id(), path.span, msg, |_| {});
+        tcx.node_span_lint(lint::builtin::UNUSED_IMPORTS, item.hir_id(), path.span, |lint| {
+            if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) {
+                lint.primary_message(format!("unused import: `{snippet}`"));
+            } else {
+                lint.primary_message("unused import");
+            }
+        });
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 6b41f79cf1e..abdf85ad707 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -317,8 +317,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                             lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
                             param.hir_id,
                             param.span,
-                            TYPE_DEFAULT_NOT_ALLOWED,
-                            |_| {},
+                            |lint| {
+                                lint.primary_message(TYPE_DEFAULT_NOT_ALLOWED);
+                            },
                         );
                     }
                     Defaults::Deny => {
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs
index 749f78e7920..7b67030836d 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs
@@ -646,8 +646,9 @@ pub(crate) fn prohibit_explicit_late_bound_lifetimes(
                 LATE_BOUND_LIFETIME_ARGUMENTS,
                 args.args[0].hir_id(),
                 multispan,
-                msg,
-                |_| {},
+                |lint| {
+                    lint.primary_message(msg);
+                },
             );
         }
 
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
index d9d36f5299b..997db338a43 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
@@ -72,8 +72,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             self.maybe_suggest_assoc_ty_bound(self_ty, &mut diag);
             diag.stash(self_ty.span, StashKey::TraitMissingMethod);
         } else {
-            let msg = "trait objects without an explicit `dyn` are deprecated";
-            tcx.node_span_lint(BARE_TRAIT_OBJECTS, self_ty.hir_id, self_ty.span, msg, |lint| {
+            tcx.node_span_lint(BARE_TRAIT_OBJECTS, self_ty.hir_id, self_ty.span, |lint| {
+                lint.primary_message("trait objects without an explicit `dyn` are deprecated");
                 if self_ty.span.can_be_used_for_suggestions() {
                     lint.multipart_suggestion_verbose(
                         "if this is an object-safe trait, use `dyn`",
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index 8caeb85204b..c0da9941dc1 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -1164,33 +1164,28 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let ty = self.lower_assoc_ty(span, assoc_ty_did, assoc_segment, bound);
 
         if let Some(variant_def_id) = variant_resolution {
-            tcx.node_span_lint(
-                AMBIGUOUS_ASSOCIATED_ITEMS,
-                hir_ref_id,
-                span,
-                "ambiguous associated item",
-                |lint| {
-                    let mut could_refer_to = |kind: DefKind, def_id, also| {
-                        let note_msg = format!(
-                            "`{}` could{} refer to the {} defined here",
-                            assoc_ident,
-                            also,
-                            tcx.def_kind_descr(kind, def_id)
-                        );
-                        lint.span_note(tcx.def_span(def_id), note_msg);
-                    };
+            tcx.node_span_lint(AMBIGUOUS_ASSOCIATED_ITEMS, hir_ref_id, span, |lint| {
+                lint.primary_message("ambiguous associated item");
+                let mut could_refer_to = |kind: DefKind, def_id, also| {
+                    let note_msg = format!(
+                        "`{}` could{} refer to the {} defined here",
+                        assoc_ident,
+                        also,
+                        tcx.def_kind_descr(kind, def_id)
+                    );
+                    lint.span_note(tcx.def_span(def_id), note_msg);
+                };
 
-                    could_refer_to(DefKind::Variant, variant_def_id, "");
-                    could_refer_to(DefKind::AssocTy, assoc_ty_did, " also");
+                could_refer_to(DefKind::Variant, variant_def_id, "");
+                could_refer_to(DefKind::AssocTy, assoc_ty_did, " also");
 
-                    lint.span_suggestion(
-                        span,
-                        "use fully-qualified syntax",
-                        format!("<{} as {}>::{}", qself_ty, tcx.item_name(trait_did), assoc_ident),
-                        Applicability::MachineApplicable,
-                    );
-                },
-            );
+                lint.span_suggestion(
+                    span,
+                    "use fully-qualified syntax",
+                    format!("<{} as {}>::{}", qself_ty, tcx.item_name(trait_did), assoc_ident),
+                    Applicability::MachineApplicable,
+                );
+            });
         }
         Ok((ty, DefKind::AssocTy, assoc_ty_did))
     }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 77f90c0c131..301ebe685d9 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -63,19 +63,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 debug!("warn_if_unreachable: id={:?} span={:?} kind={}", id, span, kind);
 
                 let msg = format!("unreachable {kind}");
-                self.tcx().node_span_lint(
-                    lint::builtin::UNREACHABLE_CODE,
-                    id,
-                    span,
-                    msg.clone(),
-                    |lint| {
-                        lint.span_label(span, msg).span_label(
-                            orig_span,
-                            custom_note
-                                .unwrap_or("any code following this expression is unreachable"),
-                        );
-                    },
-                )
+                self.tcx().node_span_lint(lint::builtin::UNREACHABLE_CODE, id, span, |lint| {
+                    lint.primary_message(msg.clone());
+                    lint.span_label(span, msg).span_label(
+                        orig_span,
+                        custom_note.unwrap_or("any code following this expression is unreachable"),
+                    );
+                })
             }
         }
     }
diff --git a/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs b/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
index e9eab6969b3..3ee10f74d98 100644
--- a/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
+++ b/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
@@ -91,11 +91,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 prelude_or_array_lint,
                 self_expr.hir_id,
                 self_expr.span,
-                format!(
-                    "trait method `{}` will become ambiguous in Rust {edition}",
-                    segment.ident.name
-                ),
                 |lint| {
+                    lint.primary_message(format!(
+                        "trait method `{}` will become ambiguous in Rust {edition}",
+                        segment.ident.name
+                    ));
+
                     let sp = self_expr.span;
 
                     let derefs = "*".repeat(pick.autoderefs);
@@ -144,11 +145,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 prelude_or_array_lint,
                 call_expr.hir_id,
                 call_expr.span,
-                format!(
-                    "trait method `{}` will become ambiguous in Rust {edition}",
-                    segment.ident.name
-                ),
                 |lint| {
+                    lint.primary_message(format!(
+                        "trait method `{}` will become ambiguous in Rust {edition}",
+                        segment.ident.name
+                    ));
+
                     let sp = call_expr.span;
                     let trait_name = self.trait_path_or_bare_name(
                         span,
@@ -251,73 +253,67 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return;
         }
 
-        self.tcx.node_span_lint(
-            RUST_2021_PRELUDE_COLLISIONS,
-            expr_id,
-            span,
-            format!(
+        self.tcx.node_span_lint(RUST_2021_PRELUDE_COLLISIONS, expr_id, span, |lint| {
+            lint.primary_message(format!(
                 "trait-associated function `{}` will become ambiguous in Rust 2021",
                 method_name.name
-            ),
-            |lint| {
-                // "type" refers to either a type or, more likely, a trait from which
-                // the associated function or method is from.
-                let container_id = pick.item.container_id(self.tcx);
-                let trait_path = self.trait_path_or_bare_name(span, expr_id, container_id);
-                let trait_generics = self.tcx.generics_of(container_id);
-
-                let trait_name =
-                    if trait_generics.own_params.len() <= trait_generics.has_self as usize {
-                        trait_path
-                    } else {
-                        let counts = trait_generics.own_counts();
-                        format!(
-                            "{}<{}>",
-                            trait_path,
+            ));
+
+            // "type" refers to either a type or, more likely, a trait from which
+            // the associated function or method is from.
+            let container_id = pick.item.container_id(self.tcx);
+            let trait_path = self.trait_path_or_bare_name(span, expr_id, container_id);
+            let trait_generics = self.tcx.generics_of(container_id);
+
+            let trait_name =
+                if trait_generics.own_params.len() <= trait_generics.has_self as usize {
+                    trait_path
+                } else {
+                    let counts = trait_generics.own_counts();
+                    format!(
+                        "{}<{}>",
+                        trait_path,
+                        std::iter::repeat("'_")
+                            .take(counts.lifetimes)
+                            .chain(std::iter::repeat("_").take(
+                                counts.types + counts.consts - trait_generics.has_self as usize
+                            ))
+                            .collect::<Vec<_>>()
+                            .join(", ")
+                    )
+                };
+
+            let mut self_ty_name = self_ty_span
+                .find_ancestor_inside(span)
+                .and_then(|span| self.sess().source_map().span_to_snippet(span).ok())
+                .unwrap_or_else(|| self_ty.to_string());
+
+            // Get the number of generics the self type has (if an Adt) unless we can determine that
+            // the user has written the self type with generics already which we (naively) do by looking
+            // for a "<" in `self_ty_name`.
+            if !self_ty_name.contains('<') {
+                if let ty::Adt(def, _) = self_ty.kind() {
+                    let generics = self.tcx.generics_of(def.did());
+                    if !generics.is_own_empty() {
+                        let counts = generics.own_counts();
+                        self_ty_name += &format!(
+                            "<{}>",
                             std::iter::repeat("'_")
                                 .take(counts.lifetimes)
-                                .chain(std::iter::repeat("_").take(
-                                    counts.types + counts.consts - trait_generics.has_self as usize
-                                ))
+                                .chain(std::iter::repeat("_").take(counts.types + counts.consts))
                                 .collect::<Vec<_>>()
                                 .join(", ")
-                        )
-                    };
-
-                let mut self_ty_name = self_ty_span
-                    .find_ancestor_inside(span)
-                    .and_then(|span| self.sess().source_map().span_to_snippet(span).ok())
-                    .unwrap_or_else(|| self_ty.to_string());
-
-                // Get the number of generics the self type has (if an Adt) unless we can determine that
-                // the user has written the self type with generics already which we (naively) do by looking
-                // for a "<" in `self_ty_name`.
-                if !self_ty_name.contains('<') {
-                    if let ty::Adt(def, _) = self_ty.kind() {
-                        let generics = self.tcx.generics_of(def.did());
-                        if !generics.is_own_empty() {
-                            let counts = generics.own_counts();
-                            self_ty_name += &format!(
-                                "<{}>",
-                                std::iter::repeat("'_")
-                                    .take(counts.lifetimes)
-                                    .chain(
-                                        std::iter::repeat("_").take(counts.types + counts.consts)
-                                    )
-                                    .collect::<Vec<_>>()
-                                    .join(", ")
-                            );
-                        }
+                        );
                     }
                 }
-                lint.span_suggestion(
-                    span,
-                    "disambiguate the associated function",
-                    format!("<{} as {}>::{}", self_ty_name, trait_name, method_name.name,),
-                    Applicability::MachineApplicable,
-                );
-            },
-        );
+            }
+            lint.span_suggestion(
+                span,
+                "disambiguate the associated function",
+                format!("<{} as {}>::{}", self_ty_name, trait_name, method_name.name,),
+                Applicability::MachineApplicable,
+            );
+        });
     }
 
     fn trait_path_or_bare_name(
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index e0a60337c3b..4d33f7e237e 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -408,8 +408,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     lint::builtin::TYVAR_BEHIND_RAW_POINTER,
                     scope_expr_id,
                     span,
-                    "type annotations needed",
-                    |_| {},
+                    |lint| {
+                        lint.primary_message("type annotations needed");
+                    },
                 );
             } else {
                 // Ended up encountering a type variable when doing autoderef,
@@ -1279,53 +1280,49 @@ impl<'tcx> Pick<'tcx> {
             return;
         }
         let def_kind = self.item.kind.as_def_kind();
-        tcx.node_span_lint(
-            lint::builtin::UNSTABLE_NAME_COLLISIONS,
-            scope_expr_id,
-            span,
-            format!(
+        tcx.node_span_lint(lint::builtin::UNSTABLE_NAME_COLLISIONS, scope_expr_id, span, |lint| {
+            lint.primary_message(format!(
                 "{} {} with this name may be added to the standard library in the future",
                 tcx.def_kind_descr_article(def_kind, self.item.def_id),
                 tcx.def_kind_descr(def_kind, self.item.def_id),
-            ),
-            |lint| {
-                match (self.item.kind, self.item.container) {
-                    (ty::AssocKind::Fn, _) => {
-                        // FIXME: This should be a `span_suggestion` instead of `help`
-                        // However `self.span` only
-                        // highlights the method name, so we can't use it. Also consider reusing
-                        // the code from `report_method_error()`.
-                        lint.help(format!(
-                            "call with fully qualified syntax `{}(...)` to keep using the current \
+            ));
+
+            match (self.item.kind, self.item.container) {
+                (ty::AssocKind::Fn, _) => {
+                    // FIXME: This should be a `span_suggestion` instead of `help`
+                    // However `self.span` only
+                    // highlights the method name, so we can't use it. Also consider reusing
+                    // the code from `report_method_error()`.
+                    lint.help(format!(
+                        "call with fully qualified syntax `{}(...)` to keep using the current \
                              method",
-                            tcx.def_path_str(self.item.def_id),
-                        ));
-                    }
-                    (ty::AssocKind::Const, ty::AssocItemContainer::TraitContainer) => {
-                        let def_id = self.item.container_id(tcx);
-                        lint.span_suggestion(
-                            span,
-                            "use the fully qualified path to the associated const",
-                            format!(
-                                "<{} as {}>::{}",
-                                self.self_ty,
-                                tcx.def_path_str(def_id),
-                                self.item.name
-                            ),
-                            Applicability::MachineApplicable,
-                        );
-                    }
-                    _ => {}
+                        tcx.def_path_str(self.item.def_id),
+                    ));
                 }
-                tcx.disabled_nightly_features(
-                    lint,
-                    Some(scope_expr_id),
-                    self.unstable_candidates.iter().map(|(candidate, feature)| {
-                        (format!(" `{}`", tcx.def_path_str(candidate.item.def_id)), *feature)
-                    }),
-                );
-            },
-        );
+                (ty::AssocKind::Const, ty::AssocItemContainer::TraitContainer) => {
+                    let def_id = self.item.container_id(tcx);
+                    lint.span_suggestion(
+                        span,
+                        "use the fully qualified path to the associated const",
+                        format!(
+                            "<{} as {}>::{}",
+                            self.self_ty,
+                            tcx.def_path_str(def_id),
+                            self.item.name
+                        ),
+                        Applicability::MachineApplicable,
+                    );
+                }
+                _ => {}
+            }
+            tcx.disabled_nightly_features(
+                lint,
+                Some(scope_expr_id),
+                self.unstable_candidates.iter().map(|(candidate, feature)| {
+                    (format!(" `{}`", tcx.def_path_str(candidate.item.def_id)), *feature)
+                }),
+            );
+        });
     }
 }
 
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index b9b220d5af8..b37aba38619 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -1950,15 +1950,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             &unmentioned_fields.iter().map(|(_, i)| i).collect::<Vec<_>>(),
         );
 
-        self.tcx.node_span_lint(NON_EXHAUSTIVE_OMITTED_PATTERNS, pat.hir_id, pat.span, "some fields are not explicitly listed", |lint| {
-        lint.span_label(pat.span, format!("field{} {} not listed", rustc_errors::pluralize!(unmentioned_fields.len()), joined_patterns));
-        lint.help(
-            "ensure that all fields are mentioned explicitly by adding the suggested fields",
-        );
-        lint.note(format!(
-            "the pattern is of type `{ty}` and the `non_exhaustive_omitted_patterns` attribute was found",
-        ));
-    });
+        self.tcx.node_span_lint(NON_EXHAUSTIVE_OMITTED_PATTERNS, pat.hir_id, pat.span, |lint| {
+            lint.primary_message("some fields are not explicitly listed");
+            lint.span_label(pat.span, format!("field{} {} not listed", rustc_errors::pluralize!(unmentioned_fields.len()), joined_patterns));
+            lint.help(
+                "ensure that all fields are mentioned explicitly by adding the suggested fields",
+            );
+            lint.note(format!(
+                "the pattern is of type `{ty}` and the `non_exhaustive_omitted_patterns` attribute was found",
+            ));
+        });
     }
 
     /// Returns a diagnostic reporting a struct pattern which does not mention some fields.
diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs
index 9d16f0d4815..89ac33dcfc0 100644
--- a/compiler/rustc_hir_typeck/src/upvar.rs
+++ b/compiler/rustc_hir_typeck/src/upvar.rs
@@ -928,8 +928,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 lint::builtin::RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES,
                 closure_hir_id,
                 closure_head_span,
-                reasons.migration_message(),
                 |lint| {
+                    lint.primary_message(reasons.migration_message());
+
                     for NeededMigration { var_hir_id, diagnostics_info } in &need_migrations {
                         // Labels all the usage of the captured variable and why they are responsible
                         // for migration being needed
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index deeb3ae090c..34b84658dc0 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -21,7 +21,7 @@ use crate::passes::{EarlyLintPassObject, LateLintPassObject};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync;
 use rustc_data_structures::unord::UnordMap;
-use rustc_errors::{Diag, DiagMessage, LintDiagnostic, MultiSpan};
+use rustc_errors::{Diag, LintDiagnostic, MultiSpan};
 use rustc_feature::Features;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
@@ -556,7 +556,6 @@ pub trait LintContext {
         &self,
         lint: &'static Lint,
         span: Option<S>,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     );
 
@@ -568,8 +567,8 @@ pub trait LintContext {
         span: S,
         decorator: impl for<'a> LintDiagnostic<'a, ()>,
     ) {
-        self.opt_span_lint(lint, Some(span), decorator.msg(), |diag| {
-            decorator.decorate_lint(diag);
+        self.opt_span_lint(lint, Some(span), |lint| {
+            decorator.decorate_lint(lint);
         });
     }
 
@@ -581,17 +580,16 @@ pub trait LintContext {
         &self,
         lint: &'static Lint,
         span: S,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
-        self.opt_span_lint(lint, Some(span), msg, decorate);
+        self.opt_span_lint(lint, Some(span), decorate);
     }
 
     /// Emit a lint from a lint struct (some type that implements `LintDiagnostic`, typically
     /// generated by `#[derive(LintDiagnostic)]`).
     fn emit_lint(&self, lint: &'static Lint, decorator: impl for<'a> LintDiagnostic<'a, ()>) {
-        self.opt_span_lint(lint, None as Option<Span>, decorator.msg(), |diag| {
-            decorator.decorate_lint(diag);
+        self.opt_span_lint(lint, None as Option<Span>, |lint| {
+            decorator.decorate_lint(lint);
         });
     }
 
@@ -599,13 +597,8 @@ pub trait LintContext {
     ///
     /// [`lint_level`]: rustc_middle::lint::lint_level#decorate-signature
     #[rustc_lint_diagnostics]
-    fn lint(
-        &self,
-        lint: &'static Lint,
-        msg: impl Into<DiagMessage>,
-        decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
-    ) {
-        self.opt_span_lint(lint, None as Option<Span>, msg, decorate);
+    fn lint(&self, lint: &'static Lint, decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>)) {
+        self.opt_span_lint(lint, None as Option<Span>, decorate);
     }
 
     /// This returns the lint level for the given lint at the current location.
@@ -668,14 +661,13 @@ impl<'tcx> LintContext for LateContext<'tcx> {
         &self,
         lint: &'static Lint,
         span: Option<S>,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
         let hir_id = self.last_node_with_lint_attrs;
 
         match span {
-            Some(s) => self.tcx.node_span_lint(lint, hir_id, s, msg, decorate),
-            None => self.tcx.node_lint(lint, hir_id, msg, decorate),
+            Some(s) => self.tcx.node_span_lint(lint, hir_id, s, decorate),
+            None => self.tcx.node_lint(lint, hir_id, decorate),
         }
     }
 
@@ -695,10 +687,9 @@ impl LintContext for EarlyContext<'_> {
         &self,
         lint: &'static Lint,
         span: Option<S>,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
-        self.builder.opt_span_lint(lint, span.map(|s| s.into()), msg, decorate)
+        self.builder.opt_span_lint(lint, span.map(|s| s.into()), decorate)
     }
 
     fn get_lint_level(&self, lint: &'static Lint) -> Level {
diff --git a/compiler/rustc_lint/src/impl_trait_overcaptures.rs b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
index 30bf80b915b..ca3e1ee06d9 100644
--- a/compiler/rustc_lint/src/impl_trait_overcaptures.rs
+++ b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
@@ -369,6 +369,7 @@ struct ImplTraitOvercapturesLint<'tcx> {
 
 impl<'a> LintDiagnostic<'a, ()> for ImplTraitOvercapturesLint<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut rustc_errors::Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_impl_trait_overcaptures);
         diag.arg("self_ty", self.self_ty.to_string())
             .arg("num_captured", self.num_captured)
             .span_note(self.uncaptured_spans, fluent::lint_note)
@@ -382,10 +383,6 @@ impl<'a> LintDiagnostic<'a, ()> for ImplTraitOvercapturesLint<'_> {
             );
         }
     }
-
-    fn msg(&self) -> rustc_errors::DiagMessage {
-        fluent::lint_impl_trait_overcaptures
-    }
 }
 
 #[derive(LintDiagnostic)]
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 12b3d1d2f9e..5d065686546 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -16,7 +16,7 @@ use crate::{
 use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxIndexMap;
-use rustc_errors::{Diag, DiagMessage, LintDiagnostic, MultiSpan};
+use rustc_errors::{Diag, LintDiagnostic, MultiSpan};
 use rustc_feature::{Features, GateIssue};
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
@@ -1063,26 +1063,19 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
             // FIXME: make this translatable
             #[allow(rustc::diagnostic_outside_of_impl)]
             #[allow(rustc::untranslatable_diagnostic)]
-            lint_level(
-                self.sess,
-                lint,
-                level,
-                src,
-                Some(span.into()),
-                fluent::lint_unknown_gated_lint,
-                |lint| {
-                    lint.arg("name", lint_id.lint.name_lower());
-                    lint.note(fluent::lint_note);
-                    rustc_session::parse::add_feature_diagnostics_for_issue(
-                        lint,
-                        &self.sess,
-                        feature,
-                        GateIssue::Language,
-                        lint_from_cli,
-                        None,
-                    );
-                },
-            );
+            lint_level(self.sess, lint, level, src, Some(span.into()), |lint| {
+                lint.primary_message(fluent::lint_unknown_gated_lint);
+                lint.arg("name", lint_id.lint.name_lower());
+                lint.note(fluent::lint_note);
+                rustc_session::parse::add_feature_diagnostics_for_issue(
+                    lint,
+                    &self.sess,
+                    feature,
+                    GateIssue::Language,
+                    lint_from_cli,
+                    None,
+                );
+            });
         }
 
         false
@@ -1103,11 +1096,10 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         &self,
         lint: &'static Lint,
         span: Option<MultiSpan>,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
         let (level, src) = self.lint_level(lint);
-        lint_level(self.sess, lint, level, src, span, msg, decorate)
+        lint_level(self.sess, lint, level, src, span, decorate)
     }
 
     #[track_caller]
@@ -1118,7 +1110,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         decorate: impl for<'a> LintDiagnostic<'a, ()>,
     ) {
         let (level, src) = self.lint_level(lint);
-        lint_level(self.sess, lint, level, src, Some(span), decorate.msg(), |lint| {
+        lint_level(self.sess, lint, level, src, Some(span), |lint| {
             decorate.decorate_lint(lint);
         });
     }
@@ -1126,7 +1118,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     #[track_caller]
     pub fn emit_lint(&self, lint: &'static Lint, decorate: impl for<'a> LintDiagnostic<'a, ()>) {
         let (level, src) = self.lint_level(lint);
-        lint_level(self.sess, lint, level, src, None, decorate.msg(), |lint| {
+        lint_level(self.sess, lint, level, src, None, |lint| {
             decorate.decorate_lint(lint);
         });
     }
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index 3bd6faca379..4b1626ca556 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -145,12 +145,9 @@ pub struct BuiltinMissingDebugImpl<'a> {
 // Needed for def_path_str
 impl<'a> LintDiagnostic<'a, ()> for BuiltinMissingDebugImpl<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut rustc_errors::Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_builtin_missing_debug_impl);
         diag.arg("debug", self.tcx.def_path_str(self.def_id));
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_builtin_missing_debug_impl
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -250,6 +247,7 @@ pub struct BuiltinUngatedAsyncFnTrackCaller<'a> {
 
 impl<'a> LintDiagnostic<'a, ()> for BuiltinUngatedAsyncFnTrackCaller<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_ungated_async_fn_track_caller);
         diag.span_label(self.label, fluent::lint_label);
         rustc_session::parse::add_feature_diagnostics(
             diag,
@@ -257,10 +255,6 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinUngatedAsyncFnTrackCaller<'_> {
             sym::async_fn_track_caller,
         );
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_ungated_async_fn_track_caller
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -432,6 +426,7 @@ pub struct BuiltinUnpermittedTypeInit<'a> {
 
 impl<'a> LintDiagnostic<'a, ()> for BuiltinUnpermittedTypeInit<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(self.msg);
         diag.arg("ty", self.ty);
         diag.span_label(self.label, fluent::lint_builtin_unpermitted_type_init_label);
         if let InhabitedPredicate::True = self.ty.inhabited_predicate(self.tcx) {
@@ -443,10 +438,6 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinUnpermittedTypeInit<'_> {
         }
         self.sub.add_to_diag(diag);
     }
-
-    fn msg(&self) -> DiagMessage {
-        self.msg.clone()
-    }
 }
 
 // FIXME(davidtwco): make translatable
@@ -1168,6 +1159,7 @@ pub struct NonFmtPanicUnused {
 // Used because of two suggestions based on one Option<Span>
 impl<'a> LintDiagnostic<'a, ()> for NonFmtPanicUnused {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_non_fmt_panic_unused);
         diag.arg("count", self.count);
         diag.note(fluent::lint_note);
         if let Some(span) = self.suggestion {
@@ -1185,10 +1177,6 @@ impl<'a> LintDiagnostic<'a, ()> for NonFmtPanicUnused {
             );
         }
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_non_fmt_panic_unused
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -1410,13 +1398,10 @@ pub struct DropTraitConstraintsDiag<'a> {
 // Needed for def_path_str
 impl<'a> LintDiagnostic<'a, ()> for DropTraitConstraintsDiag<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_drop_trait_constraints);
         diag.arg("predicate", self.predicate);
         diag.arg("needs_drop", self.tcx.def_path_str(self.def_id));
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_drop_trait_constraints
-    }
 }
 
 pub struct DropGlue<'a> {
@@ -1427,12 +1412,9 @@ pub struct DropGlue<'a> {
 // Needed for def_path_str
 impl<'a> LintDiagnostic<'a, ()> for DropGlue<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_drop_glue);
         diag.arg("needs_drop", self.tcx.def_path_str(self.def_id));
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_drop_glue
-    }
 }
 
 // types.rs
@@ -1710,6 +1692,7 @@ pub struct ImproperCTypes<'a> {
 // Used because of the complexity of Option<DiagMessage>, DiagMessage, and Option<Span>
 impl<'a> LintDiagnostic<'a, ()> for ImproperCTypes<'_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_improper_ctypes);
         diag.arg("ty", self.ty);
         diag.arg("desc", self.desc);
         diag.span_label(self.label, fluent::lint_label);
@@ -1721,10 +1704,6 @@ impl<'a> LintDiagnostic<'a, ()> for ImproperCTypes<'_> {
             diag.span_note(note, fluent::lint_note);
         }
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_improper_ctypes
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -1853,6 +1832,7 @@ pub enum UnusedDefSuggestion {
 // Needed because of def_path_str
 impl<'a> LintDiagnostic<'a, ()> for UnusedDef<'_, '_> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_unused_def);
         diag.arg("pre", self.pre);
         diag.arg("post", self.post);
         diag.arg("def", self.cx.tcx.def_path_str(self.def_id));
@@ -1864,10 +1844,6 @@ impl<'a> LintDiagnostic<'a, ()> for UnusedDef<'_, '_> {
             diag.subdiagnostic(diag.dcx, sugg);
         }
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_unused_def
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -1936,15 +1912,12 @@ pub struct AsyncFnInTraitDiag {
 
 impl<'a> LintDiagnostic<'a, ()> for AsyncFnInTraitDiag {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(fluent::lint_async_fn_in_trait);
         diag.note(fluent::lint_note);
         if let Some(sugg) = self.sugg {
             diag.multipart_suggestion(fluent::lint_suggestion, sugg, Applicability::MaybeIncorrect);
         }
     }
-
-    fn msg(&self) -> DiagMessage {
-        fluent::lint_async_fn_in_trait
-    }
 }
 
 #[derive(LintDiagnostic)]
@@ -2260,10 +2233,8 @@ pub struct UnstableFeature {
 }
 
 impl<'a> LintDiagnostic<'a, ()> for UnstableFeature {
-    fn decorate_lint<'b>(self, _diag: &'b mut Diag<'a, ()>) {}
-
-    fn msg(&self) -> DiagMessage {
-        self.msg.clone()
+    fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.primary_message(self.msg);
     }
 }
 
@@ -2725,12 +2696,9 @@ pub struct AmbiguousGlobImports {
 
 impl<'a, G: EmissionGuarantee> LintDiagnostic<'a, G> for AmbiguousGlobImports {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, G>) {
+        diag.primary_message(self.ambiguity.msg.clone());
         rustc_errors::report_ambiguity_error(diag, self.ambiguity);
     }
-
-    fn msg(&self) -> DiagMessage {
-        DiagMessage::Str(self.ambiguity.msg.clone().into())
-    }
 }
 
 #[derive(LintDiagnostic)]
diff --git a/compiler/rustc_lint/src/non_fmt_panic.rs b/compiler/rustc_lint/src/non_fmt_panic.rs
index a6057afcbd6..c9d67854112 100644
--- a/compiler/rustc_lint/src/non_fmt_panic.rs
+++ b/compiler/rustc_lint/src/non_fmt_panic.rs
@@ -123,7 +123,8 @@ fn check_panic<'tcx>(cx: &LateContext<'tcx>, f: &'tcx hir::Expr<'tcx>, arg: &'tc
     }
 
     #[allow(rustc::diagnostic_outside_of_impl)]
-    cx.span_lint(NON_FMT_PANICS, arg_span, fluent::lint_non_fmt_panic, |lint| {
+    cx.span_lint(NON_FMT_PANICS, arg_span, |lint| {
+        lint.primary_message(fluent::lint_non_fmt_panic);
         lint.arg("name", symbol);
         lint.note(fluent::lint_note);
         lint.note(fluent::lint_more_info_note);
diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic.rs b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
index 9d21d88165e..ef6005283d6 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
@@ -105,25 +105,12 @@ impl<'a> LintDiagnosticDerive<'a> {
     pub(crate) fn into_tokens(self) -> TokenStream {
         let LintDiagnosticDerive { mut structure } = self;
         let kind = DiagnosticDeriveKind::LintDiagnostic;
+        let slugs = RefCell::new(Vec::new());
         let implementation = kind.each_variant(&mut structure, |mut builder, variant| {
             let preamble = builder.preamble(variant);
             let body = builder.body(variant);
 
-            let formatting_init = &builder.formatting_init;
-            quote! {
-                #preamble
-                #formatting_init
-                #body
-                diag
-            }
-        });
-
-        let slugs = RefCell::new(Vec::new());
-        let msg = kind.each_variant(&mut structure, |mut builder, variant| {
-            // Collect the slug by generating the preamble.
-            let _ = builder.preamble(variant);
-
-            match builder.slug.value_ref() {
+            let primary_message = match builder.slug.value_ref() {
                 None => {
                     span_err(builder.span, "diagnostic slug not specified")
                         .help(
@@ -146,9 +133,18 @@ impl<'a> LintDiagnosticDerive<'a> {
                 Some(slug) => {
                     slugs.borrow_mut().push(slug.clone());
                     quote! {
-                        crate::fluent_generated::#slug.into()
+                        diag.primary_message(crate::fluent_generated::#slug);
                     }
                 }
+            };
+
+            let formatting_init = &builder.formatting_init;
+            quote! {
+                #primary_message
+                #preamble
+                #formatting_init
+                #body
+                diag
             }
         });
 
@@ -161,10 +157,6 @@ impl<'a> LintDiagnosticDerive<'a> {
                 ) {
                     #implementation;
                 }
-
-                fn msg(&self) -> rustc_errors::DiagMessage {
-                    #msg
-                }
             }
         });
         for test in slugs.borrow().iter().map(|s| generate_test(s, &structure)) {
diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs
index 086582e60a3..1e374715fd0 100644
--- a/compiler/rustc_middle/src/lint.rs
+++ b/compiler/rustc_middle/src/lint.rs
@@ -2,7 +2,7 @@ use std::cmp;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sorted_map::SortedMap;
-use rustc_errors::{Diag, DiagMessage, MultiSpan};
+use rustc_errors::{Diag, MultiSpan};
 use rustc_hir::{HirId, ItemLocalId};
 use rustc_macros::HashStable;
 use rustc_session::lint::{
@@ -269,7 +269,6 @@ pub fn lint_level(
     level: Level,
     src: LintLevelSource,
     span: Option<MultiSpan>,
-    msg: impl Into<DiagMessage>,
     decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
 ) {
     // Avoid codegen bloat from monomorphization by immediately doing dyn dispatch of `decorate` to
@@ -281,7 +280,6 @@ pub fn lint_level(
         level: Level,
         src: LintLevelSource,
         span: Option<MultiSpan>,
-        msg: impl Into<DiagMessage>,
         decorate: Box<dyn '_ + for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>)>,
     ) {
         // Check for future incompatibility lints and issue a stronger warning.
@@ -350,10 +348,6 @@ pub fn lint_level(
             }
         }
 
-        // Delay evaluating and setting the primary message until after we've
-        // suppressed the lint due to macros.
-        err.primary_message(msg);
-
         err.is_lint(lint.name_lower(), has_future_breakage);
 
         // Lint diagnostics that are covered by the expect level will not be emitted outside
@@ -418,7 +412,7 @@ pub fn lint_level(
         explain_lint_level_source(lint, level, src, &mut err);
         err.emit()
     }
-    lint_level_impl(sess, lint, level, src, span, msg, Box::new(decorate))
+    lint_level_impl(sess, lint, level, src, span, Box::new(decorate))
 }
 
 /// Returns whether `span` originates in a foreign crate's external macro.
diff --git a/compiler/rustc_middle/src/middle/stability.rs b/compiler/rustc_middle/src/middle/stability.rs
index e5df05763b0..30f93577b7f 100644
--- a/compiler/rustc_middle/src/middle/stability.rs
+++ b/compiler/rustc_middle/src/middle/stability.rs
@@ -156,6 +156,13 @@ pub struct Deprecated {
 
 impl<'a, G: EmissionGuarantee> rustc_errors::LintDiagnostic<'a, G> for Deprecated {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, G>) {
+        diag.primary_message(match &self.since_kind {
+            DeprecatedSinceKind::InEffect => crate::fluent_generated::middle_deprecated,
+            DeprecatedSinceKind::InFuture => crate::fluent_generated::middle_deprecated_in_future,
+            DeprecatedSinceKind::InVersion(_) => {
+                crate::fluent_generated::middle_deprecated_in_version
+            }
+        });
         diag.arg("kind", self.kind);
         diag.arg("path", self.path);
         if let DeprecatedSinceKind::InVersion(version) = self.since_kind {
@@ -171,16 +178,6 @@ impl<'a, G: EmissionGuarantee> rustc_errors::LintDiagnostic<'a, G> for Deprecate
             diag.subdiagnostic(diag.dcx, sub);
         }
     }
-
-    fn msg(&self) -> rustc_errors::DiagMessage {
-        match &self.since_kind {
-            DeprecatedSinceKind::InEffect => crate::fluent_generated::middle_deprecated,
-            DeprecatedSinceKind::InFuture => crate::fluent_generated::middle_deprecated_in_future,
-            DeprecatedSinceKind::InVersion(_) => {
-                crate::fluent_generated::middle_deprecated_in_version
-            }
-        }
-    }
 }
 
 fn deprecated_since_kind(is_in_effect: bool, since: DeprecatedSince) -> DeprecatedSinceKind {
@@ -597,7 +594,9 @@ impl<'tcx> TyCtxt<'tcx> {
         unmarked: impl FnOnce(Span, DefId),
     ) -> bool {
         let soft_handler = |lint, span, msg: String| {
-            self.node_span_lint(lint, id.unwrap_or(hir::CRATE_HIR_ID), span, msg, |_| {})
+            self.node_span_lint(lint, id.unwrap_or(hir::CRATE_HIR_ID), span, |lint| {
+                lint.primary_message(msg);
+            })
         };
         let eval_result =
             self.eval_stability_allow_unstable(def_id, id, span, method_span, allow_unstable);
diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs
index 04d6301116e..9addf937f94 100644
--- a/compiler/rustc_middle/src/mir/interpret/queries.rs
+++ b/compiler/rustc_middle/src/mir/interpret/queries.rs
@@ -112,8 +112,7 @@ impl<'tcx> TyCtxt<'tcx> {
                                 lint::builtin::CONST_EVALUATABLE_UNCHECKED,
                                 self.local_def_id_to_hir_id(local_def_id),
                                 self.def_span(ct.def),
-                                "cannot use constants which depend on generic parameters in types",
-                                |_| {},
+                                |lint| { lint.primary_message("cannot use constants which depend on generic parameters in types"); },
                             )
                         }
                     }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 8185c99c2fd..eaa969a90f8 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -48,9 +48,7 @@ use rustc_data_structures::sync::{self, FreezeReadGuard, Lock, Lrc, RwLock, Work
 #[cfg(parallel_compiler)]
 use rustc_data_structures::sync::{DynSend, DynSync};
 use rustc_data_structures::unord::UnordSet;
-use rustc_errors::{
-    Applicability, Diag, DiagCtxt, DiagMessage, ErrorGuaranteed, LintDiagnostic, MultiSpan,
-};
+use rustc_errors::{Applicability, Diag, DiagCtxt, ErrorGuaranteed, LintDiagnostic, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
@@ -2475,10 +2473,9 @@ impl<'tcx> TyCtxt<'tcx> {
         span: impl Into<MultiSpan>,
         decorator: impl for<'a> LintDiagnostic<'a, ()>,
     ) {
-        let msg = decorator.msg();
         let (level, src) = self.lint_level_at_node(lint, hir_id);
-        lint_level(self.sess, lint, level, src, Some(span.into()), msg, |diag| {
-            decorator.decorate_lint(diag);
+        lint_level(self.sess, lint, level, src, Some(span.into()), |lint| {
+            decorator.decorate_lint(lint);
         })
     }
 
@@ -2492,11 +2489,10 @@ impl<'tcx> TyCtxt<'tcx> {
         lint: &'static Lint,
         hir_id: HirId,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
         let (level, src) = self.lint_level_at_node(lint, hir_id);
-        lint_level(self.sess, lint, level, src, Some(span.into()), msg, decorate);
+        lint_level(self.sess, lint, level, src, Some(span.into()), decorate);
     }
 
     /// Find the crate root and the appropriate span where `use` and outer attributes can be
@@ -2547,8 +2543,8 @@ impl<'tcx> TyCtxt<'tcx> {
         id: HirId,
         decorator: impl for<'a> LintDiagnostic<'a, ()>,
     ) {
-        self.node_lint(lint, id, decorator.msg(), |diag| {
-            decorator.decorate_lint(diag);
+        self.node_lint(lint, id, |lint| {
+            decorator.decorate_lint(lint);
         })
     }
 
@@ -2561,11 +2557,10 @@ impl<'tcx> TyCtxt<'tcx> {
         self,
         lint: &'static Lint,
         id: HirId,
-        msg: impl Into<DiagMessage>,
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     ) {
         let (level, src) = self.lint_level_at_node(lint, id);
-        lint_level(self.sess, lint, level, src, None, msg, decorate);
+        lint_level(self.sess, lint, level, src, None, decorate);
     }
 
     pub fn in_scope_traits(self, id: HirId) -> Option<&'tcx [TraitCandidate]> {
diff --git a/compiler/rustc_mir_transform/src/errors.rs b/compiler/rustc_mir_transform/src/errors.rs
index 0634e321ea3..b28dcb38cb6 100644
--- a/compiler/rustc_mir_transform/src/errors.rs
+++ b/compiler/rustc_mir_transform/src/errors.rs
@@ -1,4 +1,4 @@
-use rustc_errors::{codes::*, Diag, DiagMessage, LintDiagnostic};
+use rustc_errors::{codes::*, Diag, LintDiagnostic};
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::mir::AssertKind;
 use rustc_middle::ty::TyCtxt;
@@ -50,18 +50,15 @@ pub(crate) enum AssertLintKind {
 
 impl<'a, P: std::fmt::Debug> LintDiagnostic<'a, ()> for AssertLint<P> {
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
-        let message = self.assert_kind.diagnostic_message();
+        diag.primary_message(match self.lint_kind {
+            AssertLintKind::ArithmeticOverflow => fluent::mir_transform_arithmetic_overflow,
+            AssertLintKind::UnconditionalPanic => fluent::mir_transform_operation_will_panic,
+        });
+        let label = self.assert_kind.diagnostic_message();
         self.assert_kind.add_args(&mut |name, value| {
             diag.arg(name, value);
         });
-        diag.span_label(self.span, message);
-    }
-
-    fn msg(&self) -> DiagMessage {
-        match self.lint_kind {
-            AssertLintKind::ArithmeticOverflow => fluent::mir_transform_arithmetic_overflow,
-            AssertLintKind::UnconditionalPanic => fluent::mir_transform_operation_will_panic,
-        }
+        diag.span_label(self.span, label);
     }
 }
 
@@ -104,6 +101,7 @@ pub(crate) struct MustNotSupend<'tcx, 'a> {
 // Needed for def_path_str
 impl<'a> LintDiagnostic<'a, ()> for MustNotSupend<'_, '_> {
     fn decorate_lint<'b>(self, diag: &'b mut rustc_errors::Diag<'a, ()>) {
+        diag.primary_message(fluent::mir_transform_must_not_suspend);
         diag.span_label(self.yield_sp, fluent::_subdiag::label);
         if let Some(reason) = self.reason {
             diag.subdiagnostic(diag.dcx, reason);
@@ -113,10 +111,6 @@ impl<'a> LintDiagnostic<'a, ()> for MustNotSupend<'_, '_> {
         diag.arg("def_path", self.tcx.def_path_str(self.def_id));
         diag.arg("post", self.post);
     }
-
-    fn msg(&self) -> rustc_errors::DiagMessage {
-        fluent::mir_transform_must_not_suspend
-    }
 }
 
 #[derive(Subdiagnostic)]
diff --git a/compiler/rustc_pattern_analysis/src/lints.rs b/compiler/rustc_pattern_analysis/src/lints.rs
index 1d10c9df4ab..892aacd7ac5 100644
--- a/compiler/rustc_pattern_analysis/src/lints.rs
+++ b/compiler/rustc_pattern_analysis/src/lints.rs
@@ -99,7 +99,6 @@ pub(crate) fn lint_nonexhaustive_missing_variants<'p, 'tcx>(
 
                 use rustc_errors::LintDiagnostic;
                 let mut err = rcx.tcx.dcx().struct_span_warn(arm.pat.data().span, "");
-                err.primary_message(decorator.msg());
                 decorator.decorate_lint(&mut err);
                 err.emit();
             }
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index 8ce1271fc17..f4051561dae 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -13,7 +13,7 @@ use super::elaborate;
 use crate::infer::TyCtxtInferExt;
 use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::{self, Obligation, ObligationCause};
-use rustc_errors::{DelayDm, FatalError, MultiSpan};
+use rustc_errors::{FatalError, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::query::Providers;
@@ -162,41 +162,36 @@ fn lint_object_unsafe_trait(
 ) {
     // Using `CRATE_NODE_ID` is wrong, but it's hard to get a more precise id.
     // It's also hard to get a use site span, so we use the method definition span.
-    tcx.node_span_lint(
-        WHERE_CLAUSES_OBJECT_SAFETY,
-        hir::CRATE_HIR_ID,
-        span,
-        DelayDm(|| format!("the trait `{}` cannot be made into an object", tcx.def_path_str(trait_def_id))),
-        |err| {
-            let node = tcx.hir().get_if_local(trait_def_id);
-            let mut spans = MultiSpan::from_span(span);
-            if let Some(hir::Node::Item(item)) = node {
-                spans.push_span_label(
-                    item.ident.span,
-                    "this trait cannot be made into an object...",
-                );
-                spans.push_span_label(span, format!("...because {}", violation.error_msg()));
-            } else {
-                spans.push_span_label(
-                    span,
-                    format!(
-                        "the trait cannot be made into an object because {}",
-                        violation.error_msg()
-                    ),
-                );
-            };
-            err.span_note(
-                spans,
-                "for a trait to be \"object safe\" it needs to allow building a vtable to allow the \
+    tcx.node_span_lint(WHERE_CLAUSES_OBJECT_SAFETY, hir::CRATE_HIR_ID, span, |err| {
+        err.primary_message(format!(
+            "the trait `{}` cannot be made into an object",
+            tcx.def_path_str(trait_def_id)
+        ));
+        let node = tcx.hir().get_if_local(trait_def_id);
+        let mut spans = MultiSpan::from_span(span);
+        if let Some(hir::Node::Item(item)) = node {
+            spans.push_span_label(item.ident.span, "this trait cannot be made into an object...");
+            spans.push_span_label(span, format!("...because {}", violation.error_msg()));
+        } else {
+            spans.push_span_label(
+                span,
+                format!(
+                    "the trait cannot be made into an object because {}",
+                    violation.error_msg()
+                ),
+            );
+        };
+        err.span_note(
+            spans,
+            "for a trait to be \"object safe\" it needs to allow building a vtable to allow the \
                 call to be resolvable dynamically; for more information visit \
                 <https://doc.rust-lang.org/reference/items/traits.html#object-safety>",
-            );
-            if node.is_some() {
-                // Only provide the help if its a local trait, otherwise it's not
-                violation.solution().add_to(err);
-            }
-        },
-    );
+        );
+        if node.is_some() {
+            // Only provide the help if its a local trait, otherwise it's not
+            violation.solution().add_to(err);
+        }
+    });
 }
 
 fn sized_trait_bound_spans<'tcx>(
diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
index 826bb706f48..c2727ae6bfd 100644
--- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs
@@ -21,7 +21,7 @@ use crate::traits::{
     self, coherence, FutureCompatOverlapErrorKind, ObligationCause, ObligationCtxt,
 };
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_errors::{codes::*, DelayDm, Diag, EmissionGuarantee};
+use rustc_errors::{codes::*, Diag, EmissionGuarantee};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::bug;
 use rustc_middle::ty::{self, ImplSubject, Ty, TyCtxt, TypeVisitableExt};
@@ -449,7 +449,7 @@ fn report_conflicting_impls<'tcx>(
         }
     }
 
-    let msg = DelayDm(|| {
+    let msg = || {
         format!(
             "conflicting implementations of trait `{}`{}{}",
             overlap.trait_ref.print_trait_sugared(),
@@ -459,7 +459,7 @@ fn report_conflicting_impls<'tcx>(
                 _ => "",
             }
         )
-    });
+    };
 
     // Don't report overlap errors if the header references error
     if let Err(err) = (overlap.trait_ref, overlap.self_ty).error_reported() {
@@ -471,7 +471,7 @@ fn report_conflicting_impls<'tcx>(
             let reported = if overlap.with_impl.is_local()
                 || tcx.ensure().orphan_check_impl(impl_def_id).is_ok()
             {
-                let mut err = tcx.dcx().struct_span_err(impl_span, msg);
+                let mut err = tcx.dcx().struct_span_err(impl_span, msg());
                 err.code(E0119);
                 decorate(tcx, &overlap, impl_span, &mut err);
                 err.emit()
@@ -485,15 +485,10 @@ fn report_conflicting_impls<'tcx>(
                 FutureCompatOverlapErrorKind::OrderDepTraitObjects => ORDER_DEPENDENT_TRAIT_OBJECTS,
                 FutureCompatOverlapErrorKind::LeakCheck => COHERENCE_LEAK_CHECK,
             };
-            tcx.node_span_lint(
-                lint,
-                tcx.local_def_id_to_hir_id(impl_def_id),
-                impl_span,
-                msg,
-                |err| {
-                    decorate(tcx, &overlap, impl_span, err);
-                },
-            );
+            tcx.node_span_lint(lint, tcx.local_def_id_to_hir_id(impl_def_id), impl_span, |err| {
+                err.primary_message(msg());
+                decorate(tcx, &overlap, impl_span, err);
+            });
             Ok(())
         }
     }