Rename Handler as DiagCtxt.

compiler/rustc_builtin_macros/src/errors.rs

@@ -1,5 +1,5 @@
 use rustc_errors::{
-    AddToDiagnostic, DiagnosticBuilder, ErrorGuaranteed, Handler, IntoDiagnostic, MultiSpan,
+    AddToDiagnostic, DiagCtxt, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, MultiSpan,
     SingleLabelManySpans,
 };
 use rustc_macros::{Diagnostic, Subdiagnostic};
@@ -448,7 +448,7 @@ pub(crate) struct EnvNotDefinedWithUserMessage {
 // Hand-written implementation to support custom user messages.
 impl<'a> IntoDiagnostic<'a> for EnvNotDefinedWithUserMessage {
     #[track_caller]
-    fn into_diagnostic(self, handler: &'a Handler) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
+    fn into_diagnostic(self, handler: &'a DiagCtxt) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
         #[expect(
             rustc::untranslatable_diagnostic,
             reason = "cannot translate user-provided messages"
@@ -802,7 +802,7 @@ pub(crate) struct AsmClobberNoReg {
 }
 
 impl<'a> IntoDiagnostic<'a> for AsmClobberNoReg {
-    fn into_diagnostic(self, handler: &'a Handler) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
+    fn into_diagnostic(self, handler: &'a DiagCtxt) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
         let mut diag =
             handler.struct_err(crate::fluent_generated::builtin_macros_asm_clobber_no_reg);
         diag.set_span(self.spans.clone());

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -38,7 +38,7 @@ enum ProcMacro {
 struct CollectProcMacros<'a> {
     macros: Vec<ProcMacro>,
     in_root: bool,
-    handler: &'a rustc_errors::Handler,
+    handler: &'a rustc_errors::DiagCtxt,
     source_map: &'a SourceMap,
     is_proc_macro_crate: bool,
     is_test_crate: bool,
@@ -52,7 +52,7 @@ pub fn inject(
     is_proc_macro_crate: bool,
     has_proc_macro_decls: bool,
     is_test_crate: bool,
-    handler: &rustc_errors::Handler,
+    handler: &rustc_errors::DiagCtxt,
 ) {
     let ecfg = ExpansionConfig::default("proc_macro".to_string(), features);
     let mut cx = ExtCtxt::new(sess, ecfg, resolver, None);

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -389,7 +389,7 @@ fn get_test_name(i: &ast::Item) -> Option<Symbol> {
     attr::first_attr_value_str_by_name(&i.attrs, sym::rustc_test_marker)
 }
 
-fn get_test_runner(sd: &rustc_errors::Handler, krate: &ast::Crate) -> Option<ast::Path> {
+fn get_test_runner(sd: &rustc_errors::DiagCtxt, krate: &ast::Crate) -> Option<ast::Path> {
     let test_attr = attr::find_by_name(&krate.attrs, sym::test_runner)?;
     let meta_list = test_attr.meta_item_list()?;
     let span = test_attr.span;