UPDATE - rename DiagnosticHandler macro to Diagnostic

compiler/rustc_macros/src/diagnostics/diagnostic.rs

@@ -21,7 +21,7 @@ impl<'a> SessionDiagnosticDerive<'a> {
             builder: DiagnosticDeriveBuilder {
                 diag,
                 fields: build_field_mapping(&structure),
-                kind: DiagnosticDeriveKind::DiagnosticHandler,
+                kind: DiagnosticDeriveKind::Diagnostic,
                 code: None,
                 slug: None,
             },
@@ -72,7 +72,7 @@ impl<'a> SessionDiagnosticDerive<'a> {
             } else {
                 span_err(
                     ast.span().unwrap(),
-                    "`#[derive(DiagnosticHandler)]` can only be used on structs",
+                    "`#[derive(Diagnostic)]` can only be used on structs",
                 )
                 .emit();
 

compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs

@@ -21,12 +21,12 @@ use synstructure::{BindingInfo, Structure};
 /// What kind of diagnostic is being derived - a fatal/error/warning or a lint?
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub(crate) enum DiagnosticDeriveKind {
-    DiagnosticHandler,
+    Diagnostic,
     LintDiagnostic,
 }
 
 /// Tracks persistent information required for building up individual calls to diagnostic methods
-/// for generated diagnostic derives - both `DiagnosticHandler` for fatal/errors/warnings and
+/// for generated diagnostic derives - both `Diagnostic` for fatal/errors/warnings and
 /// `LintDiagnostic` for lints.
 pub(crate) struct DiagnosticDeriveBuilder {
     /// The identifier to use for the generated `DiagnosticBuilder` instance.
@@ -333,7 +333,7 @@ impl DiagnosticDeriveBuilder {
             }
             "primary_span" => {
                 match self.kind {
-                    DiagnosticDeriveKind::DiagnosticHandler => {
+                    DiagnosticDeriveKind::Diagnostic => {
                         report_error_if_not_applied_to_span(attr, &info)?;
 
                         Ok(quote! {

compiler/rustc_macros/src/diagnostics/mod.rs

@@ -12,7 +12,7 @@ use quote::format_ident;
 use subdiagnostic::SessionSubdiagnosticDerive;
 use synstructure::Structure;
 
-/// Implements `#[derive(DiagnosticHandler)]`, which allows for errors to be specified as a struct,
+/// Implements `#[derive(Diagnostic)]`, which allows for errors to be specified as a struct,
 /// independent from the actual diagnostics emitting code.
 ///
 /// ```ignore (rust)
@@ -22,7 +22,7 @@ use synstructure::Structure;
 /// # use rustc_span::{symbol::Ident, Span};
 /// # extern crate rust_middle;
 /// # use rustc_middle::ty::Ty;
-/// #[derive(DiagnosticHandler)]
+/// #[derive(Diagnostic)]
 /// #[diag(borrowck::move_out_of_borrow, code = "E0505")]
 /// pub struct MoveOutOfBorrowError<'tcx> {
 ///     pub name: Ident,
@@ -56,7 +56,7 @@ use synstructure::Structure;
 /// });
 /// ```
 ///
-/// See rustc dev guide for more examples on using the `#[derive(DiagnosticHandler)]`:
+/// See rustc dev guide for more examples on using the `#[derive(Diagnostic)]`:
 /// <https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html>
 pub fn session_diagnostic_derive(s: Structure<'_>) -> TokenStream {
     SessionDiagnosticDerive::new(format_ident!("diag"), format_ident!("handler"), s).into_tokens()

compiler/rustc_macros/src/lib.rs

@@ -127,7 +127,7 @@ decl_derive!([TypeFoldable, attributes(type_foldable)] => type_foldable::type_fo
 decl_derive!([TypeVisitable, attributes(type_visitable)] => type_visitable::type_visitable_derive);
 decl_derive!([Lift, attributes(lift)] => lift::lift_derive);
 decl_derive!(
-    [DiagnosticHandler, attributes(
+    [Diagnostic, attributes(
         // struct attributes
         diag,
         help,