3 files changed, 14 insertions, 18 deletions
diff --git a/compiler/rustc_builtin_macros/src/errors.rs b/compiler/rustc_builtin_macros/src/errors.rs
index f304a37be85..23d2da128e5 100644
--- a/compiler/rustc_builtin_macros/src/errors.rs
+++ b/compiler/rustc_builtin_macros/src/errors.rs
@@ -1,6 +1,6 @@
 use rustc_errors::{
-    codes::*, AddToDiagnostic, DiagCtxt, DiagnosticBuilder, EmissionGuarantee, IntoDiagnostic,
-    Level, MultiSpan, SingleLabelManySpans, SubdiagnosticMessageOp,
+    codes::*, AddToDiagnostic, Diag, DiagCtxt, EmissionGuarantee, IntoDiagnostic, Level, MultiSpan,
+    SingleLabelManySpans, SubdiagnosticMessageOp,
 };
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::{symbol::Ident, Span, Symbol};
@@ -448,12 +448,12 @@ pub(crate) struct EnvNotDefinedWithUserMessage {
 // Hand-written implementation to support custom user messages.
 impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for EnvNotDefinedWithUserMessage {
     #[track_caller]
-    fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G> {
+    fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> Diag<'a, G> {
         #[expect(
             rustc::untranslatable_diagnostic,
             reason = "cannot translate user-provided messages"
         )]
-        let mut diag = DiagnosticBuilder::new(dcx, level, self.msg_from_user.to_string());
+        let mut diag = Diag::new(dcx, level, self.msg_from_user.to_string());
         diag.span(self.span);
         diag
     }
@@ -613,7 +613,7 @@ pub(crate) struct FormatUnusedArg {
 impl AddToDiagnostic for FormatUnusedArg {
     fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagnosticMessageOp<G>>(
         self,
-        diag: &mut DiagnosticBuilder<'_, G>,
+        diag: &mut Diag<'_, G>,
         f: F,
     ) {
         diag.arg("named", self.named);
@@ -800,7 +800,7 @@ pub(crate) struct AsmClobberNoReg {
 }
 
 impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for AsmClobberNoReg {
-    fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> DiagnosticBuilder<'a, G> {
+    fn into_diagnostic(self, dcx: &'a DiagCtxt, level: Level) -> Diag<'a, G> {
         // eager translation as `span_labels` takes `AsRef<str>`
         let lbl1 = dcx.eagerly_translate_to_string(
             crate::fluent_generated::builtin_macros_asm_clobber_abi,
@@ -810,14 +810,10 @@ impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for AsmClobberNoReg {
             crate::fluent_generated::builtin_macros_asm_clobber_outputs,
             [].into_iter(),
         );
-        DiagnosticBuilder::new(
-            dcx,
-            level,
-            crate::fluent_generated::builtin_macros_asm_clobber_no_reg,
-        )
-        .with_span(self.spans.clone())
-        .with_span_labels(self.clobbers, &lbl1)
-        .with_span_labels(self.spans, &lbl2)
+        Diag::new(dcx, level, crate::fluent_generated::builtin_macros_asm_clobber_no_reg)
+            .with_span(self.spans.clone())
+            .with_span_labels(self.clobbers, &lbl1)
+            .with_span_labels(self.spans, &lbl2)
     }
 }
 
diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs
index 06c2b617706..0ce9d7ead82 100644
--- a/compiler/rustc_builtin_macros/src/format.rs
+++ b/compiler/rustc_builtin_macros/src/format.rs
@@ -8,7 +8,7 @@ use rustc_ast::{
     FormatDebugHex, FormatOptions, FormatPlaceholder, FormatSign, FormatTrait,
 };
 use rustc_data_structures::fx::FxHashSet;
-use rustc_errors::{Applicability, DiagnosticBuilder, MultiSpan, PResult, SingleLabelManySpans};
+use rustc_errors::{Applicability, Diag, MultiSpan, PResult, SingleLabelManySpans};
 use rustc_expand::base::{self, *};
 use rustc_parse::parser::Recovered;
 use rustc_parse_format as parse;
@@ -730,7 +730,7 @@ fn report_redundant_format_arguments<'a>(
     args: &FormatArguments,
     used: &[bool],
     placeholders: Vec<(Span, &str)>,
-) -> Option<DiagnosticBuilder<'a>> {
+) -> Option<Diag<'a>> {
     let mut fmt_arg_indices = vec![];
     let mut args_spans = vec![];
     let mut fmt_spans = vec![];
diff --git a/compiler/rustc_builtin_macros/src/test.rs b/compiler/rustc_builtin_macros/src/test.rs
index 0631f796894..81ac78dd58f 100644
--- a/compiler/rustc_builtin_macros/src/test.rs
+++ b/compiler/rustc_builtin_macros/src/test.rs
@@ -5,7 +5,7 @@ use crate::util::{check_builtin_macro_attribute, warn_on_duplicate_attribute};
 use rustc_ast::ptr::P;
 use rustc_ast::{self as ast, attr, GenericParamKind};
 use rustc_ast_pretty::pprust;
-use rustc_errors::{Applicability, DiagnosticBuilder, Level};
+use rustc_errors::{Applicability, Diag, Level};
 use rustc_expand::base::*;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{ErrorGuaranteed, FileNameDisplayPreference, Span};
@@ -410,7 +410,7 @@ fn not_testable_error(cx: &ExtCtxt<'_>, attr_sp: Span, item: Option<&ast::Item>)
         Some(ast::ItemKind::MacCall(_)) => Level::Warning,
         _ => Level::Error,
     };
-    let mut err = DiagnosticBuilder::<()>::new(dcx, level, msg);
+    let mut err = Diag::<()>::new(dcx, level, msg);
     err.span(attr_sp);
     if let Some(item) = item {
         err.span_label(