Auto merge of #121780 - nnethercote:diag-renaming2, r=davidtwco

Diagnostic renaming 2

A sequel to #121489.

r? `@davidtwco`

7 files changed, 114 insertions, 117 deletions

diff --git a/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs
index e6668769b95..b71b93cc67c 100644
--- a/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs
+++ b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs
@@ -9,8 +9,8 @@ use crate::emitter::FileWithAnnotatedLines;
 use crate::snippet::Line;
 use crate::translation::{to_fluent_args, Translate};
 use crate::{
-    CodeSuggestion, DiagInner, DiagnosticMessage, Emitter, ErrCode, FluentBundle,
-    LazyFallbackBundle, Level, MultiSpan, Style, Subdiag,
+    CodeSuggestion, DiagInner, DiagMessage, Emitter, ErrCode, FluentBundle, LazyFallbackBundle,
+    Level, MultiSpan, Style, Subdiag,
 };
 use annotate_snippets::{Annotation, AnnotationType, Renderer, Slice, Snippet, SourceAnnotation};
 use rustc_data_structures::sync::Lrc;
@@ -125,7 +125,7 @@ impl AnnotateSnippetEmitter {
     fn emit_messages_default(
         &mut self,
         level: &Level,
-        messages: &[(DiagnosticMessage, Style)],
+        messages: &[(DiagMessage, Style)],
         args: &FluentArgs<'_>,
         code: &Option<ErrCode>,
         msp: &MultiSpan,
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 1c820bfd01f..5390dda9b21 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -1,7 +1,7 @@
 use crate::snippet::Style;
 use crate::{
-    CodeSuggestion, DiagCtxt, DiagnosticMessage, ErrCode, ErrorGuaranteed, ExplicitBug, Level,
-    MultiSpan, StashKey, SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
+    CodeSuggestion, DiagCtxt, DiagMessage, ErrCode, ErrorGuaranteed, ExplicitBug, Level, MultiSpan,
+    StashKey, SubdiagMessage, Substitution, SubstitutionPart, SuggestionStyle,
 };
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_error_messages::fluent_value_from_str_list_sep_by_and;
@@ -182,15 +182,14 @@ where
 
     /// Add a subdiagnostic to an existing diagnostic where `f` is invoked on every message used
     /// (to optionally perform eager translation).
-    fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagnosticMessageOp<G>>(
+    fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
         f: F,
     );
 }
 
-pub trait SubdiagnosticMessageOp<G> =
-    Fn(&mut Diag<'_, G>, SubdiagnosticMessage) -> SubdiagnosticMessage;
+pub trait SubdiagMessageOp<G> = Fn(&mut Diag<'_, G>, SubdiagMessage) -> SubdiagMessage;
 
 /// Trait implemented by lint types. This should not be implemented manually. Instead, use
 /// `#[derive(LintDiagnostic)]` -- see [rustc_macros::LintDiagnostic].
@@ -199,7 +198,7 @@ pub trait DecorateLint<'a, G: EmissionGuarantee> {
     /// Decorate and emit a lint.
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, G>);
 
-    fn msg(&self) -> DiagnosticMessage;
+    fn msg(&self) -> DiagMessage;
 }
 
 #[derive(Clone, Debug, Encodable, Decodable)]
@@ -291,7 +290,7 @@ pub struct DiagInner {
     // outside of what methods in this crate themselves allow.
     pub(crate) level: Level,
 
-    pub messages: Vec<(DiagnosticMessage, Style)>,
+    pub messages: Vec<(DiagMessage, Style)>,
     pub code: Option<ErrCode>,
     pub span: MultiSpan,
     pub children: Vec<Subdiag>,
@@ -312,12 +311,12 @@ pub struct DiagInner {
 
 impl DiagInner {
     #[track_caller]
-    pub fn new<M: Into<DiagnosticMessage>>(level: Level, message: M) -> Self {
+    pub fn new<M: Into<DiagMessage>>(level: Level, message: M) -> Self {
         DiagInner::new_with_messages(level, vec![(message.into(), Style::NoStyle)])
     }
 
     #[track_caller]
-    pub fn new_with_messages(level: Level, messages: Vec<(DiagnosticMessage, Style)>) -> Self {
+    pub fn new_with_messages(level: Level, messages: Vec<(DiagMessage, Style)>) -> Self {
         DiagInner {
             level,
             messages,
@@ -396,8 +395,8 @@ impl DiagInner {
     // See comment on `Diag::subdiagnostic_message_to_diagnostic_message`.
     pub(crate) fn subdiagnostic_message_to_diagnostic_message(
         &self,
-        attr: impl Into<SubdiagnosticMessage>,
-    ) -> DiagnosticMessage {
+        attr: impl Into<SubdiagMessage>,
+    ) -> DiagMessage {
         let msg =
             self.messages.iter().map(|(msg, _)| msg).next().expect("diagnostic with no messages");
         msg.with_subdiagnostic_message(attr.into())
@@ -406,7 +405,7 @@ impl DiagInner {
     pub(crate) fn sub(
         &mut self,
         level: Level,
-        message: impl Into<SubdiagnosticMessage>,
+        message: impl Into<SubdiagMessage>,
         span: MultiSpan,
     ) {
         let sub = Subdiag {
@@ -429,7 +428,7 @@ impl DiagInner {
         &self,
     ) -> (
         &Level,
-        &[(DiagnosticMessage, Style)],
+        &[(DiagMessage, Style)],
         &Option<ErrCode>,
         &MultiSpan,
         &[Subdiag],
@@ -472,7 +471,7 @@ impl PartialEq for DiagInner {
 #[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
 pub struct Subdiag {
     pub level: Level,
-    pub messages: Vec<(DiagnosticMessage, Style)>,
+    pub messages: Vec<(DiagMessage, Style)>,
     pub span: MultiSpan,
 }
 
@@ -578,7 +577,7 @@ macro_rules! with_fn {
 impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn new<M: Into<DiagnosticMessage>>(dcx: &'a DiagCtxt, level: Level, message: M) -> Self {
+    pub fn new(dcx: &'a DiagCtxt, level: Level, message: impl Into<DiagMessage>) -> Self {
         Self::new_diagnostic(dcx, DiagInner::new(level, message))
     }
 
@@ -623,7 +622,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// ["primary span"][`MultiSpan`]; only the `Span` supplied when creating the diagnostic is
     /// primary.
     #[rustc_lint_diagnostics]
-    pub fn span_label(&mut self, span: Span, label: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn span_label(&mut self, span: Span, label: impl Into<SubdiagMessage>) -> &mut Self {
         let msg = self.subdiagnostic_message_to_diagnostic_message(label);
         self.span.push_span_label(span, msg);
         self
@@ -718,7 +717,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_note,
     /// Add a note attached to this diagnostic.
     #[rustc_lint_diagnostics]
-    pub fn note(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn note(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::Note, msg, MultiSpan::new());
         self
     } }
@@ -729,7 +728,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     }
 
     /// This is like [`Diag::note()`], but it's only printed once.
-    pub fn note_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn note_once(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::OnceNote, msg, MultiSpan::new());
         self
     }
@@ -741,7 +740,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_note(
         &mut self,
         sp: impl Into<MultiSpan>,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
     ) -> &mut Self {
         self.sub(Level::Note, msg, sp.into());
         self
@@ -752,7 +751,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_note_once<S: Into<MultiSpan>>(
         &mut self,
         sp: S,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
     ) -> &mut Self {
         self.sub(Level::OnceNote, msg, sp.into());
         self
@@ -761,7 +760,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_warn,
     /// Add a warning attached to this diagnostic.
     #[rustc_lint_diagnostics]
-    pub fn warn(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn warn(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::Warning, msg, MultiSpan::new());
         self
     } }
@@ -772,7 +771,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_warn<S: Into<MultiSpan>>(
         &mut self,
         sp: S,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
     ) -> &mut Self {
         self.sub(Level::Warning, msg, sp.into());
         self
@@ -781,13 +780,13 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_help,
     /// Add a help message attached to this diagnostic.
     #[rustc_lint_diagnostics]
-    pub fn help(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn help(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::Help, msg, MultiSpan::new());
         self
     } }
 
     /// This is like [`Diag::help()`], but it's only printed once.
-    pub fn help_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+    pub fn help_once(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::OnceHelp, msg, MultiSpan::new());
         self
     }
@@ -804,7 +803,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_help<S: Into<MultiSpan>>(
         &mut self,
         sp: S,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
     ) -> &mut Self {
         self.sub(Level::Help, msg, sp.into());
         self
@@ -841,7 +840,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// In other words, multiple changes need to be applied as part of this suggestion.
     pub fn multipart_suggestion(
         &mut self,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: Vec<(Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
@@ -857,7 +856,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// In other words, multiple changes need to be applied as part of this suggestion.
     pub fn multipart_suggestion_verbose(
         &mut self,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: Vec<(Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
@@ -872,7 +871,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// [`Diag::multipart_suggestion()`] but you can set the [`SuggestionStyle`].
     pub fn multipart_suggestion_with_style(
         &mut self,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         mut suggestion: Vec<(Span, String)>,
         applicability: Applicability,
         style: SuggestionStyle,
@@ -914,7 +913,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// improve understandability.
     pub fn tool_only_multipart_suggestion(
         &mut self,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: Vec<(Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
@@ -947,7 +946,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestion(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
     ) -> &mut Self {
@@ -965,7 +964,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestion_with_style(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
         style: SuggestionStyle,
@@ -990,7 +989,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestion_verbose(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1010,7 +1009,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestions(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestions: impl IntoIterator<Item = String>,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1026,7 +1025,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestions_with_style(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestions: impl IntoIterator<Item = String>,
         applicability: Applicability,
         style: SuggestionStyle,
@@ -1055,7 +1054,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// See also [`Diag::multipart_suggestion()`].
     pub fn multipart_suggestions(
         &mut self,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1102,7 +1101,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestion_short(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1125,7 +1124,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn span_suggestion_hidden(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1148,7 +1147,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     pub fn tool_only_span_suggestion(
         &mut self,
         sp: Span,
-        msg: impl Into<SubdiagnosticMessage>,
+        msg: impl Into<SubdiagMessage>,
         suggestion: impl ToString,
         applicability: Applicability,
     ) -> &mut Self {
@@ -1203,7 +1202,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_primary_message,
     /// Add a primary message.
-    pub fn primary_message(&mut self, msg: impl Into<DiagnosticMessage>) -> &mut Self {
+    pub fn primary_message(&mut self, msg: impl Into<DiagMessage>) -> &mut Self {
         self.messages[0] = (msg.into(), Style::NoStyle);
         self
     } }
@@ -1219,13 +1218,13 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     } }
 
-    /// Helper function that takes a `SubdiagnosticMessage` and returns a `DiagnosticMessage` by
+    /// Helper function that takes a `SubdiagMessage` and returns a `DiagMessage` by
     /// combining it with the primary message of the diagnostic (if translatable, otherwise it just
     /// passes the user's string along).
     pub(crate) fn subdiagnostic_message_to_diagnostic_message(
         &self,
-        attr: impl Into<SubdiagnosticMessage>,
-    ) -> DiagnosticMessage {
+        attr: impl Into<SubdiagMessage>,
+    ) -> DiagMessage {
         self.deref().subdiagnostic_message_to_diagnostic_message(attr)
     }
 
@@ -1233,7 +1232,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// public methods above.
     ///
     /// Used by `proc_macro_server` for implementing `server::Diagnostic`.
-    pub fn sub(&mut self, level: Level, message: impl Into<SubdiagnosticMessage>, span: MultiSpan) {
+    pub fn sub(&mut self, level: Level, message: impl Into<SubdiagMessage>, span: MultiSpan) {
         self.deref_mut().sub(level, message, span);
     }
 
@@ -1338,7 +1337,7 @@ impl<G: EmissionGuarantee> Drop for Diag<'_, G> {
             Some(diag) if !panicking() => {
                 self.dcx.emit_diagnostic(DiagInner::new(
                     Level::Bug,
-                    DiagnosticMessage::from("the following error was constructed but not emitted"),
+                    DiagMessage::from("the following error was constructed but not emitted"),
                 ));
                 self.dcx.emit_diagnostic(*diag);
                 panic!("error was constructed but not emitted");
diff --git a/compiler/rustc_errors/src/diagnostic_impls.rs b/compiler/rustc_errors/src/diagnostic_impls.rs
index 70c8d971868..839bd65e4a6 100644
--- a/compiler/rustc_errors/src/diagnostic_impls.rs
+++ b/compiler/rustc_errors/src/diagnostic_impls.rs
@@ -2,7 +2,7 @@ use crate::diagnostic::DiagLocation;
 use crate::{fluent_generated as fluent, AddToDiagnostic};
 use crate::{
     Diag, DiagArgValue, DiagCtxt, EmissionGuarantee, ErrCode, IntoDiagnostic, IntoDiagnosticArg,
-    Level, SubdiagnosticMessageOp,
+    Level, SubdiagMessageOp,
 };
 use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
@@ -298,7 +298,7 @@ pub struct SingleLabelManySpans {
     pub label: &'static str,
 }
 impl AddToDiagnostic for SingleLabelManySpans {
-    fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagnosticMessageOp<G>>(
+    fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagMessageOp<G>>(
         self,
         diag: &mut Diag<'_, G>,
         _: F,
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 5637c05d04c..293d8f01e67 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -17,7 +17,7 @@ use crate::snippet::{
 use crate::styled_buffer::StyledBuffer;
 use crate::translation::{to_fluent_args, Translate};
 use crate::{
-    diagnostic::DiagLocation, CodeSuggestion, DiagCtxt, DiagInner, DiagnosticMessage, ErrCode,
+    diagnostic::DiagLocation, CodeSuggestion, DiagCtxt, DiagInner, DiagMessage, ErrCode,
     FluentBundle, LazyFallbackBundle, Level, MultiSpan, Subdiag, SubstitutionHighlight,
     SuggestionStyle, TerminalUrl,
 };
@@ -339,7 +339,7 @@ pub trait Emitter: Translate {
 
                 children.push(Subdiag {
                     level: Level::Note,
-                    messages: vec![(DiagnosticMessage::from(msg), Style::NoStyle)],
+                    messages: vec![(DiagMessage::from(msg), Style::NoStyle)],
                     span: MultiSpan::new(),
                 });
             }
@@ -543,12 +543,10 @@ pub struct SilentEmitter {
     pub fatal_note: String,
 }
 
-pub fn silent_translate<'a>(
-    message: &'a DiagnosticMessage,
-) -> Result<Cow<'_, str>, TranslateError<'_>> {
+pub fn silent_translate<'a>(message: &'a DiagMessage) -> Result<Cow<'_, str>, TranslateError<'_>> {
     match message {
-        DiagnosticMessage::Str(msg) | DiagnosticMessage::Translated(msg) => Ok(Cow::Borrowed(msg)),
-        DiagnosticMessage::FluentIdentifier(identifier, _) => {
+        DiagMessage::Str(msg) | DiagMessage::Translated(msg) => Ok(Cow::Borrowed(msg)),
+        DiagMessage::FluentIdentifier(identifier, _) => {
             // Any value works here.
             Ok(identifier.clone())
         }
@@ -568,7 +566,7 @@ impl Translate for SilentEmitter {
     // subdiagnostics result in a call to this.
     fn translate_message<'a>(
         &'a self,
-        message: &'a DiagnosticMessage,
+        message: &'a DiagMessage,
         _: &'a FluentArgs<'_>,
     ) -> Result<Cow<'_, str>, TranslateError<'_>> {
         silent_translate(message)
@@ -1216,7 +1214,7 @@ impl HumanEmitter {
     fn msgs_to_buffer(
         &self,
         buffer: &mut StyledBuffer,
-        msgs: &[(DiagnosticMessage, Style)],
+        msgs: &[(DiagMessage, Style)],
         args: &FluentArgs<'_>,
         padding: usize,
         label: &str,
@@ -1291,7 +1289,7 @@ impl HumanEmitter {
     fn emit_messages_default_inner(
         &mut self,
         msp: &MultiSpan,
-        msgs: &[(DiagnosticMessage, Style)],
+        msgs: &[(DiagMessage, Style)],
         args: &FluentArgs<'_>,
         code: &Option<ErrCode>,
         level: &Level,
@@ -2060,7 +2058,7 @@ impl HumanEmitter {
     fn emit_messages_default(
         &mut self,
         level: &Level,
-        messages: &[(DiagnosticMessage, Style)],
+        messages: &[(DiagMessage, Style)],
         args: &FluentArgs<'_>,
         code: &Option<ErrCode>,
         span: &MultiSpan,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 6b1ccbc5f7c..0a6d66f52da 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -39,7 +39,7 @@ pub use codes::*;
 pub use diagnostic::{
     AddToDiagnostic, BugAbort, DecorateLint, Diag, DiagArg, DiagArgMap, DiagArgName, DiagArgValue,
     DiagInner, DiagStyledString, EmissionGuarantee, FatalAbort, IntoDiagnostic, IntoDiagnosticArg,
-    StringPart, Subdiag, SubdiagnosticMessageOp,
+    StringPart, Subdiag, SubdiagMessageOp,
 };
 pub use diagnostic_impls::{
     DiagArgFromDisplay, DiagSymbolList, ExpectedLifetimeParameter, IndicateAnonymousLifetime,
@@ -47,8 +47,8 @@ pub use diagnostic_impls::{
 };
 pub use emitter::ColorConfig;
 pub use rustc_error_messages::{
-    fallback_fluent_bundle, fluent_bundle, DelayDm, DiagnosticMessage, FluentBundle,
-    LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagnosticMessage,
+    fallback_fluent_bundle, fluent_bundle, DelayDm, DiagMessage, FluentBundle, LanguageIdentifier,
+    LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagMessage,
 };
 pub use rustc_lint_defs::{pluralize, Applicability};
 pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
@@ -154,7 +154,7 @@ pub struct CodeSuggestion {
     /// ]
     /// ```
     pub substitutions: Vec<Substitution>,
-    pub msg: DiagnosticMessage,
+    pub msg: DiagMessage,
     /// Visual representation of this suggestion.
     pub style: SuggestionStyle,
     /// Whether or not the suggestion is approximate
@@ -631,12 +631,12 @@ impl DiagCtxt {
         }
     }
 
-    /// Translate `message` eagerly with `args` to `SubdiagnosticMessage::Eager`.
+    /// Translate `message` eagerly with `args` to `SubdiagMessage::Eager`.
     pub fn eagerly_translate<'a>(
         &self,
-        message: DiagnosticMessage,
+        message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
-    ) -> SubdiagnosticMessage {
+    ) -> SubdiagMessage {
         let inner = self.inner.borrow();
         inner.eagerly_translate(message, args)
     }
@@ -644,7 +644,7 @@ impl DiagCtxt {
     /// Translate `message` eagerly with `args` to `String`.
     pub fn eagerly_translate_to_string<'a>(
         &self,
-        message: DiagnosticMessage,
+        message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
     ) -> String {
         let inner = self.inner.borrow();
@@ -904,7 +904,7 @@ impl DiagCtxt {
                 // configuration like `--cap-lints allow --force-warn bare_trait_objects`.
                 inner.emit_diagnostic(DiagInner::new(
                     ForceWarning(None),
-                    DiagnosticMessage::Str(warnings),
+                    DiagMessage::Str(warnings),
                 ));
             }
             (_, 0) => {
@@ -1078,13 +1078,13 @@ impl DiagCtxt {
 impl DiagCtxt {
     // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
     #[track_caller]
-    pub fn struct_bug(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, BugAbort> {
+    pub fn struct_bug(&self, msg: impl Into<DiagMessage>) -> Diag<'_, BugAbort> {
         Diag::new(self, Bug, msg)
     }
 
     // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
     #[track_caller]
-    pub fn bug(&self, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn bug(&self, msg: impl Into<DiagMessage>) -> ! {
         self.struct_bug(msg).emit()
     }
 
@@ -1093,14 +1093,14 @@ impl DiagCtxt {
     pub fn struct_span_bug(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> Diag<'_, BugAbort> {
         self.struct_bug(msg).with_span(span)
     }
 
     // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
     #[track_caller]
-    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) -> ! {
         self.struct_span_bug(span, msg).emit()
     }
 
@@ -1116,13 +1116,13 @@ impl DiagCtxt {
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_fatal(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, FatalAbort> {
+    pub fn struct_fatal(&self, msg: impl Into<DiagMessage>) -> Diag<'_, FatalAbort> {
         Diag::new(self, Fatal, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn fatal(&self, msg: impl Into<DiagMessage>) -> ! {
         self.struct_fatal(msg).emit()
     }
 
@@ -1131,14 +1131,14 @@ impl DiagCtxt {
     pub fn struct_span_fatal(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> Diag<'_, FatalAbort> {
         self.struct_fatal(msg).with_span(span)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) -> ! {
         self.struct_span_fatal(span, msg).emit()
     }
 
@@ -1174,13 +1174,13 @@ impl DiagCtxt {
     // FIXME: This method should be removed (every error should have an associated error code).
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_err(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_> {
+    pub fn struct_err(&self, msg: impl Into<DiagMessage>) -> Diag<'_> {
         Diag::new(self, Error, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+    pub fn err(&self, msg: impl Into<DiagMessage>) -> ErrorGuaranteed {
         self.struct_err(msg).emit()
     }
 
@@ -1189,7 +1189,7 @@ impl DiagCtxt {
     pub fn struct_span_err(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> Diag<'_> {
         self.struct_err(msg).with_span(span)
     }
@@ -1199,7 +1199,7 @@ impl DiagCtxt {
     pub fn span_err(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> ErrorGuaranteed {
         self.struct_span_err(span, msg).emit()
     }
@@ -1217,7 +1217,7 @@ impl DiagCtxt {
     /// Ensures that an error is printed. See `Level::DelayedBug`.
     // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
     #[track_caller]
-    pub fn delayed_bug(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+    pub fn delayed_bug(&self, msg: impl Into<DiagMessage>) -> ErrorGuaranteed {
         Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg).emit()
     }
 
@@ -1230,20 +1230,20 @@ impl DiagCtxt {
     pub fn span_delayed_bug(
         &self,
         sp: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> ErrorGuaranteed {
         Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg).with_span(sp).emit()
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, ()> {
+    pub fn struct_warn(&self, msg: impl Into<DiagMessage>) -> Diag<'_, ()> {
         Diag::new(self, Warning, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
+    pub fn warn(&self, msg: impl Into<DiagMessage>) {
         self.struct_warn(msg).emit()
     }
 
@@ -1252,14 +1252,14 @@ impl DiagCtxt {
     pub fn struct_span_warn(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> Diag<'_, ()> {
         self.struct_warn(msg).with_span(span)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+    pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) {
         self.struct_span_warn(span, msg).emit()
     }
 
@@ -1275,13 +1275,13 @@ impl DiagCtxt {
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_note(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, ()> {
+    pub fn struct_note(&self, msg: impl Into<DiagMessage>) -> Diag<'_, ()> {
         Diag::new(self, Note, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn note(&self, msg: impl Into<DiagnosticMessage>) {
+    pub fn note(&self, msg: impl Into<DiagMessage>) {
         self.struct_note(msg).emit()
     }
 
@@ -1290,14 +1290,14 @@ impl DiagCtxt {
     pub fn struct_span_note(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
     ) -> Diag<'_, ()> {
         self.struct_note(msg).with_span(span)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn span_note(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+    pub fn span_note(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) {
         self.struct_span_note(span, msg).emit()
     }
 
@@ -1313,19 +1313,19 @@ impl DiagCtxt {
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_help(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, ()> {
+    pub fn struct_help(&self, msg: impl Into<DiagMessage>) -> Diag<'_, ()> {
         Diag::new(self, Help, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_failure_note(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, ()> {
+    pub fn struct_failure_note(&self, msg: impl Into<DiagMessage>) -> Diag<'_, ()> {
         Diag::new(self, FailureNote, msg)
     }
 
     #[rustc_lint_diagnostics]
     #[track_caller]
-    pub fn struct_allow(&self, msg: impl Into<DiagnosticMessage>) -> Diag<'_, ()> {
+    pub fn struct_allow(&self, msg: impl Into<DiagMessage>) -> Diag<'_, ()> {
         Diag::new(self, Allow, msg)
     }
 
@@ -1333,7 +1333,7 @@ impl DiagCtxt {
     #[track_caller]
     pub fn struct_expect(
         &self,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<DiagMessage>,
         id: LintExpectationId,
     ) -> Diag<'_, ()> {
         Diag::new(self, Expect(id), msg)
@@ -1553,19 +1553,19 @@ impl DiagCtxtInner {
         self.has_errors().or_else(|| self.delayed_bugs.get(0).map(|(_, guar)| guar).copied())
     }
 
-    /// Translate `message` eagerly with `args` to `SubdiagnosticMessage::Eager`.
+    /// Translate `message` eagerly with `args` to `SubdiagMessage::Eager`.
     pub fn eagerly_translate<'a>(
         &self,
-        message: DiagnosticMessage,
+        message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
-    ) -> SubdiagnosticMessage {
-        SubdiagnosticMessage::Translated(Cow::from(self.eagerly_translate_to_string(message, args)))
+    ) -> SubdiagMessage {
+        SubdiagMessage::Translated(Cow::from(self.eagerly_translate_to_string(message, args)))
     }
 
     /// Translate `message` eagerly with `args` to `String`.
     pub fn eagerly_translate_to_string<'a>(
         &self,
-        message: DiagnosticMessage,
+        message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
     ) -> String {
         let args = crate::translation::to_fluent_args(args);
@@ -1575,8 +1575,8 @@ impl DiagCtxtInner {
     fn eagerly_translate_for_subdiag(
         &self,
         diag: &DiagInner,
-        msg: impl Into<SubdiagnosticMessage>,
-    ) -> SubdiagnosticMessage {
+        msg: impl Into<SubdiagMessage>,
+    ) -> SubdiagMessage {
         let msg = diag.subdiagnostic_message_to_diagnostic_message(msg);
         self.eagerly_translate(msg, diag.args.iter())
     }
diff --git a/compiler/rustc_errors/src/tests.rs b/compiler/rustc_errors/src/tests.rs
index 79a2af7f38f..50d58aec36a 100644
--- a/compiler/rustc_errors/src/tests.rs
+++ b/compiler/rustc_errors/src/tests.rs
@@ -5,7 +5,7 @@ use crate::FluentBundle;
 use rustc_data_structures::sync::{IntoDynSyncSend, Lrc};
 use rustc_error_messages::fluent_bundle::resolver::errors::{ReferenceKind, ResolverError};
 use rustc_error_messages::langid;
-use rustc_error_messages::DiagnosticMessage;
+use rustc_error_messages::DiagMessage;
 
 struct Dummy {
     bundle: FluentBundle,
@@ -53,7 +53,7 @@ fn wellformed_fluent() {
     args.set("name", "Foo");
     args.set("ty", "std::string::String");
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("suggestion".into()),
         );
@@ -65,7 +65,7 @@ fn wellformed_fluent() {
     }
 
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("value_borrowed_label".into()),
         );
@@ -77,7 +77,7 @@ fn wellformed_fluent() {
     }
 
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("occurs_because_label".into()),
         );
@@ -88,7 +88,7 @@ fn wellformed_fluent() {
         );
 
         {
-            let message = DiagnosticMessage::FluentIdentifier(
+            let message = DiagMessage::FluentIdentifier(
                 "mir_build_borrow_of_moved_value".into(),
                 Some("label".into()),
             );
@@ -112,7 +112,7 @@ fn misformed_fluent() {
     args.set("name", "Foo");
     args.set("ty", "std::string::String");
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("value_borrowed_label".into()),
         );
@@ -141,7 +141,7 @@ fn misformed_fluent() {
     }
 
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("label".into()),
         );
@@ -168,7 +168,7 @@ fn misformed_fluent() {
     }
 
     {
-        let message = DiagnosticMessage::FluentIdentifier(
+        let message = DiagMessage::FluentIdentifier(
             "mir_build_borrow_of_moved_value".into(),
             Some("occurs_because_label".into()),
         );
diff --git a/compiler/rustc_errors/src/translation.rs b/compiler/rustc_errors/src/translation.rs
index 1f98ba4c3b9..bf0026568ce 100644
--- a/compiler/rustc_errors/src/translation.rs
+++ b/compiler/rustc_errors/src/translation.rs
@@ -1,6 +1,6 @@
 use crate::error::{TranslateError, TranslateErrorKind};
 use crate::snippet::Style;
-use crate::{DiagArg, DiagnosticMessage, FluentBundle};
+use crate::{DiagArg, DiagMessage, FluentBundle};
 use rustc_data_structures::sync::Lrc;
 pub use rustc_error_messages::FluentArgs;
 use std::borrow::Cow;
@@ -37,10 +37,10 @@ pub trait Translate {
     /// unavailable for the requested locale.
     fn fallback_fluent_bundle(&self) -> &FluentBundle;
 
-    /// Convert `DiagnosticMessage`s to a string, performing translation if necessary.
+    /// Convert `DiagMessage`s to a string, performing translation if necessary.
     fn translate_messages(
         &self,
-        messages: &[(DiagnosticMessage, Style)],
+        messages: &[(DiagMessage, Style)],
         args: &FluentArgs<'_>,
     ) -> Cow<'_, str> {
         Cow::Owned(
@@ -51,18 +51,18 @@ pub trait Translate {
         )
     }
 
-    /// Convert a `DiagnosticMessage` to a string, performing translation if necessary.
+    /// Convert a `DiagMessage` to a string, performing translation if necessary.
     fn translate_message<'a>(
         &'a self,
-        message: &'a DiagnosticMessage,
+        message: &'a DiagMessage,
         args: &'a FluentArgs<'_>,
     ) -> Result<Cow<'_, str>, TranslateError<'_>> {
         trace!(?message, ?args);
         let (identifier, attr) = match message {
-            DiagnosticMessage::Str(msg) | DiagnosticMessage::Translated(msg) => {
+            DiagMessage::Str(msg) | DiagMessage::Translated(msg) => {
                 return Ok(Cow::Borrowed(msg));
             }
-            DiagnosticMessage::FluentIdentifier(identifier, attr) => (identifier, attr),
+            DiagMessage::FluentIdentifier(identifier, attr) => (identifier, attr),
         };
         let translate_with_bundle =
             |bundle: &'a FluentBundle| -> Result<Cow<'_, str>, TranslateError<'_>> {