UPDATE - rename SessionSubdiagnostic macro to Subdiagnostic

Also renames:
- sym::AddSubdiagnostic to sym:: Subdiagnostic
- rustc_diagnostic_item = "AddSubdiagnostic" to rustc_diagnostic_item = "Subdiagnostic"

24 files changed, 130 insertions, 128 deletions

diff --git a/compiler/rustc_ast_lowering/src/errors.rs b/compiler/rustc_ast_lowering/src/errors.rs
index 6dbb2582a37..052979d6d45 100644
--- a/compiler/rustc_ast_lowering/src/errors.rs
+++ b/compiler/rustc_ast_lowering/src/errors.rs
@@ -1,5 +1,5 @@
 use rustc_errors::{fluent, AddToDiagnostic, Applicability, Diagnostic, DiagnosticArgFromDisplay};
-use rustc_macros::{Diagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::{symbol::Ident, Span, Symbol};
 
 #[derive(Diagnostic, Clone, Copy)]
@@ -221,7 +221,7 @@ pub struct InvalidAsmTemplateModifierRegClass {
     pub sub: InvalidAsmTemplateModifierRegClassSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum InvalidAsmTemplateModifierRegClassSub {
     #[note(ast_lowering::support_modifiers)]
     SupportModifier { class_name: Symbol, modifiers: String },
diff --git a/compiler/rustc_ast_passes/src/errors.rs b/compiler/rustc_ast_passes/src/errors.rs
index 20e2209acbe..035f0ce1cbc 100644
--- a/compiler/rustc_ast_passes/src/errors.rs
+++ b/compiler/rustc_ast_passes/src/errors.rs
@@ -71,7 +71,7 @@ pub struct InvalidVisibility {
     pub note: Option<InvalidVisibilityNote>,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum InvalidVisibilityNote {
     #[note(ast_passes::individual_impl_items)]
     IndividualImplItems,
diff --git a/compiler/rustc_attr/src/session_diagnostics.rs b/compiler/rustc_attr/src/session_diagnostics.rs
index 5e8f9b79850..940a48ed915 100644
--- a/compiler/rustc_attr/src/session_diagnostics.rs
+++ b/compiler/rustc_attr/src/session_diagnostics.rs
@@ -98,7 +98,7 @@ pub(crate) struct InvalidIssueString {
 
 // The error kinds of `IntErrorKind` are duplicated here in order to allow the messages to be
 // translatable.
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum InvalidIssueStringCause {
     #[label(attr::must_not_be_zero)]
     MustNotBeZero {
@@ -274,7 +274,7 @@ pub(crate) struct IncorrectReprFormatGeneric<'a> {
     pub cause: Option<IncorrectReprFormatGenericCause<'a>>,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum IncorrectReprFormatGenericCause<'a> {
     #[suggestion(attr::suggestion, code = "{name}({int})", applicability = "machine-applicable")]
     Int {
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index aa8f26eece5..9f19453a1a6 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,5 +1,5 @@
 use rustc_errors::{IntoDiagnosticArg, MultiSpan};
-use rustc_macros::{Diagnostic, LintDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
 
@@ -23,7 +23,7 @@ pub(crate) struct HigherRankedLifetimeError {
     pub span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum HigherRankedErrorCause {
     #[note(borrowck::could_not_prove)]
     CouldNotProve { predicate: String },
@@ -72,7 +72,7 @@ pub(crate) struct FnMutError {
     pub ty_err: FnMutReturnTypeErr,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum VarHereDenote {
     #[label(borrowck::var_here_captured)]
     Captured {
@@ -91,7 +91,7 @@ pub(crate) enum VarHereDenote {
     },
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum FnMutReturnTypeErr {
     #[label(borrowck::returned_closure_escaped)]
     ReturnClosure {
@@ -117,7 +117,7 @@ pub(crate) struct LifetimeOutliveErr {
     pub span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum LifetimeReturnCategoryErr<'a> {
     #[label(borrowck::returned_lifetime_wrong)]
     WrongReturn {
@@ -149,7 +149,7 @@ impl IntoDiagnosticArg for RegionName {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum RequireStaticErr {
     #[note(borrowck::used_impl_require_static)]
     UsedImpl {
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index b6e0f3faa73..ff33ae7e8f2 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -268,14 +268,14 @@ type FluentId = Cow<'static, str>;
 /// Translatable messages for subdiagnostics are typically attributes attached to a larger Fluent
 /// message so messages of this type must be combined with a `DiagnosticMessage` (using
 /// `DiagnosticMessage::with_subdiagnostic_message`) before rendering. However, subdiagnostics from
-/// the `SessionSubdiagnostic` derive refer to Fluent identifiers directly.
+/// the `Subdiagnostic` derive refer to Fluent identifiers directly.
 #[rustc_diagnostic_item = "SubdiagnosticMessage"]
 pub enum SubdiagnosticMessage {
     /// Non-translatable diagnostic message.
     // FIXME(davidtwco): can a `Cow<'static, str>` be used here?
     Str(String),
     /// Identifier of a Fluent message. Instances of this variant are generated by the
-    /// `SessionSubdiagnostic` derive.
+    /// `Subdiagnostic` derive.
     FluentIdentifier(FluentId),
     /// Attribute of a Fluent message. Needs to be combined with a Fluent identifier to produce an
     /// actual translated message. Instances of this variant are generated by the `fluent_messages`
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index d3a263ac56d..c66889189ad 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -176,8 +176,9 @@ impl IntoDiagnosticArg for hir::ConstContext {
 }
 
 /// Trait implemented by error types. This should not be implemented manually. Instead, use
-/// `#[derive(SessionSubdiagnostic)]` -- see [rustc_macros::SessionSubdiagnostic].
-#[rustc_diagnostic_item = "AddSubdiagnostic"]
+/// `#[derive(Subdiagnostic)]` -- see [rustc_macros::Subdiagnostic].
+#[cfg_attr(bootstrap, rustc_diagnostic_item = "AddSubdiagnostic")]
+#[cfg_attr(not(bootstrap), rustc_diagnostic_item = "Subdiagnostic")]
 pub trait AddToDiagnostic {
     /// Add a subdiagnostic to an existing diagnostic.
     fn add_to_diagnostic(self, diag: &mut Diagnostic);
@@ -891,8 +892,8 @@ impl Diagnostic {
         self
     }
 
-    /// Add a subdiagnostic from a type that implements `SessionSubdiagnostic` - see
-    /// [rustc_macros::SessionSubdiagnostic].
+    /// Add a subdiagnostic from a type that implements `Subdiagnostic` - see
+    /// [rustc_macros::Subdiagnostic].
     pub fn subdiagnostic(&mut self, subdiagnostic: impl AddToDiagnostic) -> &mut Self {
         subdiagnostic.add_to_diagnostic(self);
         self
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index 7764ffd246e..6d2c7aac6af 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -593,7 +593,7 @@ pub fn compile_declarative_macro(
     (mk_syn_ext(expander), rule_spans)
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum ExplainDocComment {
     #[label(expand::explain_doc_comment_inner)]
     Inner {
diff --git a/compiler/rustc_lint/src/errors.rs b/compiler/rustc_lint/src/errors.rs
index 0c66ce475c4..3a89d90c88a 100644
--- a/compiler/rustc_lint/src/errors.rs
+++ b/compiler/rustc_lint/src/errors.rs
@@ -1,5 +1,5 @@
 use rustc_errors::{fluent, AddToDiagnostic, IntoDiagnostic, ErrorGuaranteed, Handler};
-use rustc_macros::{Diagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_session::lint::Level;
 use rustc_span::{Span, Symbol};
 
@@ -51,7 +51,7 @@ pub struct MalformedAttribute {
     pub sub: MalformedAttributeSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum MalformedAttributeSub {
     #[label(lint::bad_attribute_argument)]
     BadAttributeArgument(#[primary_span] Span),
diff --git a/compiler/rustc_lint/src/internal.rs b/compiler/rustc_lint/src/internal.rs
index 36d8ade22ae..942475d31fe 100644
--- a/compiler/rustc_lint/src/internal.rs
+++ b/compiler/rustc_lint/src/internal.rs
@@ -404,7 +404,7 @@ impl LateLintPass<'_> for Diagnostics {
                 let Impl { of_trait: Some(of_trait), .. } = impl_ &&
                 let Some(def_id) = of_trait.trait_def_id() &&
                 let Some(name) = cx.tcx.get_diagnostic_name(def_id) &&
-                matches!(name, sym::Diagnostic | sym::AddSubdiagnostic | sym::DecorateLint)
+                matches!(name, sym::Diagnostic | sym::Subdiagnostic | sym::DecorateLint)
             {
                 found_impl = true;
                 break;
diff --git a/compiler/rustc_macros/src/diagnostics/mod.rs b/compiler/rustc_macros/src/diagnostics/mod.rs
index 1d5b32c2556..8eaa8b87c0f 100644
--- a/compiler/rustc_macros/src/diagnostics/mod.rs
+++ b/compiler/rustc_macros/src/diagnostics/mod.rs
@@ -9,7 +9,7 @@ use diagnostic::{LintDiagnosticDerive, SessionDiagnosticDerive};
 pub(crate) use fluent::fluent_messages;
 use proc_macro2::TokenStream;
 use quote::format_ident;
-use subdiagnostic::SessionSubdiagnosticDerive;
+use subdiagnostic::SubdiagnosticDerive;
 use synstructure::Structure;
 
 /// Implements `#[derive(Diagnostic)]`, which allows for errors to be specified as a struct,
@@ -108,12 +108,12 @@ pub fn lint_diagnostic_derive(s: Structure<'_>) -> TokenStream {
     LintDiagnosticDerive::new(format_ident!("diag"), s).into_tokens()
 }
 
-/// Implements `#[derive(SessionSubdiagnostic)]`, which allows for labels, notes, helps and
+/// Implements `#[derive(Subdiagnostic)]`, which allows for labels, notes, helps and
 /// suggestions to be specified as a structs or enums, independent from the actual diagnostics
 /// emitting code or diagnostic derives.
 ///
 /// ```ignore (rust)
-/// #[derive(SessionSubdiagnostic)]
+/// #[derive(Subdiagnostic)]
 /// pub enum ExpectedIdentifierLabel<'tcx> {
 ///     #[label(parser::expected_identifier)]
 ///     WithoutFound {
@@ -128,7 +128,7 @@ pub fn lint_diagnostic_derive(s: Structure<'_>) -> TokenStream {
 ///     }
 /// }
 ///
-/// #[derive(SessionSubdiagnostic)]
+/// #[derive(Subdiagnostic)]
 /// #[suggestion_verbose(parser::raw_identifier)]
 /// pub struct RawIdentifierSuggestion<'tcx> {
 ///     #[primary_span]
@@ -155,5 +155,5 @@ pub fn lint_diagnostic_derive(s: Structure<'_>) -> TokenStream {
 /// diag.subdiagnostic(RawIdentifierSuggestion { span, applicability, ident });
 /// ```
 pub fn session_subdiagnostic_derive(s: Structure<'_>) -> TokenStream {
-    SessionSubdiagnosticDerive::new(s).into_tokens()
+    SubdiagnosticDerive::new(s).into_tokens()
 }
diff --git a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
index f1bb7feb062..bdeca3420bc 100644
--- a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
@@ -98,19 +98,19 @@ impl quote::IdentFragment for SubdiagnosticKind {
 }
 
 /// The central struct for constructing the `add_to_diagnostic` method from an annotated struct.
-pub(crate) struct SessionSubdiagnosticDerive<'a> {
+pub(crate) struct SubdiagnosticDerive<'a> {
     structure: Structure<'a>,
     diag: syn::Ident,
 }
 
-impl<'a> SessionSubdiagnosticDerive<'a> {
+impl<'a> SubdiagnosticDerive<'a> {
     pub(crate) fn new(structure: Structure<'a>) -> Self {
         let diag = format_ident!("diag");
         Self { structure, diag }
     }
 
     pub(crate) fn into_tokens(self) -> TokenStream {
-        let SessionSubdiagnosticDerive { mut structure, diag } = self;
+        let SubdiagnosticDerive { mut structure, diag } = self;
         let implementation = {
             let ast = structure.ast();
             let span = ast.span().unwrap();
@@ -119,7 +119,7 @@ impl<'a> SessionSubdiagnosticDerive<'a> {
                 syn::Data::Union(..) => {
                     span_err(
                         span,
-                        "`#[derive(SessionSubdiagnostic)]` can only be used on structs and enums",
+                        "`#[derive(Subdiagnostic)]` can only be used on structs and enums",
                     );
                 }
             }
@@ -146,7 +146,7 @@ impl<'a> SessionSubdiagnosticDerive<'a> {
                     }
                 }
 
-                let mut builder = SessionSubdiagnosticDeriveBuilder {
+                let mut builder = SubdiagnosticDeriveBuilder {
                     diag: &diag,
                     variant,
                     span,
@@ -178,10 +178,10 @@ impl<'a> SessionSubdiagnosticDerive<'a> {
 }
 
 /// Tracks persistent information required for building up the call to add to the diagnostic
-/// for the final generated method. This is a separate struct to `SessionSubdiagnosticDerive`
+/// for the final generated method. This is a separate struct to `SubdiagnosticDerive`
 /// only to be able to destructure and split `self.builder` and the `self.structure` up to avoid a
 /// double mut borrow later on.
-struct SessionSubdiagnosticDeriveBuilder<'a> {
+struct SubdiagnosticDeriveBuilder<'a> {
     /// The identifier to use for the generated `DiagnosticBuilder` instance.
     diag: &'a syn::Ident,
 
@@ -205,7 +205,7 @@ struct SessionSubdiagnosticDeriveBuilder<'a> {
     has_suggestion_parts: bool,
 }
 
-impl<'a> HasFieldMap for SessionSubdiagnosticDeriveBuilder<'a> {
+impl<'a> HasFieldMap for SubdiagnosticDeriveBuilder<'a> {
     fn get_field_binding(&self, field: &String) -> Option<&TokenStream> {
         self.fields.get(field)
     }
@@ -241,7 +241,7 @@ impl<'a> FromIterator<&'a SubdiagnosticKind> for KindsStatistics {
     }
 }
 
-impl<'a> SessionSubdiagnosticDeriveBuilder<'a> {
+impl<'a> SubdiagnosticDeriveBuilder<'a> {
     fn identify_kind(&mut self) -> Result<Vec<(SubdiagnosticKind, Path)>, DiagnosticDeriveError> {
         let mut kind_slugs = vec![];
 
diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index 9dd7ccad8bb..8fd23ee5ced 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -161,7 +161,7 @@ decl_derive!(
         suggestion_verbose)] => diagnostics::lint_diagnostic_derive
 );
 decl_derive!(
-    [SessionSubdiagnostic, attributes(
+    [Subdiagnostic, attributes(
         // struct/variant attributes
         label,
         help,
diff --git a/compiler/rustc_middle/src/error.rs b/compiler/rustc_middle/src/error.rs
index 6d15feb888a..a4ceb494569 100644
--- a/compiler/rustc_middle/src/error.rs
+++ b/compiler/rustc_middle/src/error.rs
@@ -25,7 +25,7 @@ pub struct OpaqueHiddenTypeMismatch<'tcx> {
     pub sub: TypeMismatchReason,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum TypeMismatchReason {
     #[label(middle::conflict_types)]
     ConflictType {
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 9989ebb7cdf..78bc29fc375 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -20,7 +20,7 @@ use rustc_errors::{
     fluent, Applicability, DiagnosticBuilder, DiagnosticMessage, Handler, MultiSpan, PResult,
 };
 use rustc_errors::{pluralize, struct_span_err, Diagnostic, ErrorGuaranteed};
-use rustc_macros::{Diagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{Span, SpanSnippetError, DUMMY_SP};
@@ -261,7 +261,7 @@ struct BadTypePlus {
     pub sub: BadTypePlusSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum BadTypePlusSub {
     #[suggestion(
         parser::add_paren,
@@ -342,7 +342,7 @@ pub struct InvalidVariableDeclaration {
     pub sub: InvalidVariableDeclarationSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum InvalidVariableDeclarationSub {
     #[suggestion(
         parser::switch_mut_let_order,
@@ -372,7 +372,7 @@ pub(crate) struct InvalidComparisonOperator {
     pub sub: InvalidComparisonOperatorSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum InvalidComparisonOperatorSub {
     #[suggestion_short(
         parser::use_instead,
@@ -400,7 +400,7 @@ pub(crate) struct InvalidLogicalOperator {
     pub sub: InvalidLogicalOperatorSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum InvalidLogicalOperatorSub {
     #[suggestion_short(
         parser::use_amp_amp_for_conjunction,
@@ -605,7 +605,7 @@ pub(crate) struct IfExpressionMissingThenBlock {
     pub sub: IfExpressionMissingThenBlockSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum IfExpressionMissingThenBlockSub {
     #[help(parser::condition_possibly_unfinished)]
     UnfinishedCondition(#[primary_span] Span),
@@ -668,7 +668,7 @@ pub(crate) struct MissingInInForLoop {
     pub sub: MissingInInForLoopSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum MissingInInForLoopSub {
     // Has been misleading, at least in the past (closed Issue #48492), thus maybe-incorrect
     #[suggestion_short(parser::use_in_not_of, applicability = "maybe-incorrect", code = "in")]
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index bff2978bd13..52aea9bba43 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -1,5 +1,5 @@
 use rustc_errors::{Applicability, MultiSpan};
-use rustc_macros::{Diagnostic, LintDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_span::{Span, Symbol};
 
 #[derive(LintDiagnostic)]
@@ -583,7 +583,7 @@ pub struct MacroExport;
 #[diag(passes::plugin_registrar)]
 pub struct PluginRegistrar;
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum UnusedNote {
     #[note(passes::unused_empty_lints_note)]
     EmptyList { name: Symbol },
diff --git a/compiler/rustc_privacy/src/errors.rs b/compiler/rustc_privacy/src/errors.rs
index 71552119482..f3a617c2f0f 100644
--- a/compiler/rustc_privacy/src/errors.rs
+++ b/compiler/rustc_privacy/src/errors.rs
@@ -1,5 +1,5 @@
 use rustc_errors::DiagnosticArgFromDisplay;
-use rustc_macros::{Diagnostic, LintDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_span::{Span, Symbol};
 
 #[derive(Diagnostic)]
@@ -14,7 +14,7 @@ pub struct FieldIsPrivate {
     pub label: FieldIsPrivateLabel,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum FieldIsPrivateLabel {
     #[label(privacy::field_is_private_is_update_syntax_label)]
     IsUpdateSyntax {
diff --git a/compiler/rustc_query_system/src/error.rs b/compiler/rustc_query_system/src/error.rs
index 4c770152f12..ceec75fce28 100644
--- a/compiler/rustc_query_system/src/error.rs
+++ b/compiler/rustc_query_system/src/error.rs
@@ -1,6 +1,7 @@
 use rustc_errors::AddToDiagnostic;
 use rustc_session::Limit;
 use rustc_span::{Span, Symbol};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 
 pub struct CycleStack {
     pub span: Span,
@@ -20,7 +21,7 @@ pub enum HandleCycleError {
     DelayBug,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum StackCount {
     #[note(query_system::cycle_stack_single)]
     Single,
@@ -28,7 +29,7 @@ pub enum StackCount {
     Multiple,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum Alias {
     #[note(query_system::cycle_recursive_ty_alias)]
     #[help(query_system::cycle_recursive_ty_alias_help1)]
@@ -38,7 +39,7 @@ pub enum Alias {
     Trait,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[note(query_system::cycle_usage)]
 pub struct CycleUsage {
     #[primary_span]
diff --git a/compiler/rustc_session/src/errors.rs b/compiler/rustc_session/src/errors.rs
index 7ffe757463f..997a45272bc 100644
--- a/compiler/rustc_session/src/errors.rs
+++ b/compiler/rustc_session/src/errors.rs
@@ -34,13 +34,13 @@ pub struct FeatureGateError<'a> {
     pub explain: &'a str,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[note(session::feature_diagnostic_for_issue)]
 pub struct FeatureDiagnosticForIssue {
     pub n: NonZeroU32,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[help(session::feature_diagnostic_help)]
 pub struct FeatureDiagnosticHelp {
     pub feature: Symbol,
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index ea69334616b..1baad6a9fd7 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -125,7 +125,6 @@ symbols! {
     Symbols {
         AcqRel,
         Acquire,
-        AddSubdiagnostic,
         Alignment,
         Any,
         Arc,
@@ -283,6 +282,7 @@ symbols! {
         String,
         StructuralEq,
         StructuralPartialEq,
+        Subdiagnostic,
         SubdiagnosticMessage,
         Sync,
         T,
diff --git a/compiler/rustc_ty_utils/src/errors.rs b/compiler/rustc_ty_utils/src/errors.rs
index 85165187310..753c474a34b 100644
--- a/compiler/rustc_ty_utils/src/errors.rs
+++ b/compiler/rustc_ty_utils/src/errors.rs
@@ -1,6 +1,6 @@
 //! Errors emitted by ty_utils
 
-use rustc_macros::{Diagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
 
@@ -22,7 +22,7 @@ pub struct GenericConstantTooComplex {
     pub sub: GenericConstantTooComplexSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum GenericConstantTooComplexSub {
     #[label(ty_utils::borrow_not_supported)]
     BorrowNotSupported(#[primary_span] Span),
diff --git a/compiler/rustc_typeck/src/errors.rs b/compiler/rustc_typeck/src/errors.rs
index 6f00591d54e..44df47e2fa0 100644
--- a/compiler/rustc_typeck/src/errors.rs
+++ b/compiler/rustc_typeck/src/errors.rs
@@ -1,7 +1,7 @@
 //! Errors emitted by typeck.
 use rustc_errors::IntoDiagnostic;
 use rustc_errors::{error_code, Applicability, DiagnosticBuilder, ErrorGuaranteed, Handler};
-use rustc_macros::{Diagnostic, LintDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::{symbol::Ident, Span, Symbol};
 
@@ -194,7 +194,7 @@ pub struct AddressOfTemporaryTaken {
     pub span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum AddReturnTypeSuggestion {
     #[suggestion(
         typeck::add_return_type_add,
@@ -217,7 +217,7 @@ pub enum AddReturnTypeSuggestion {
     },
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum ExpectedReturnTypeLabel<'tcx> {
     #[label(typeck::expected_default_return_type)]
     Unit {
diff --git a/src/test/ui-fulldeps/internal-lints/diagnostics.rs b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
index 93766de9a91..4c2c28dc336 100644
--- a/src/test/ui-fulldeps/internal-lints/diagnostics.rs
+++ b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
@@ -15,7 +15,7 @@ use rustc_errors::{
     AddToDiagnostic, IntoDiagnostic, Diagnostic, DiagnosticBuilder,
     ErrorGuaranteed, Handler, fluent
 };
-use rustc_macros::{Diagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::Span;
 
 #[derive(Diagnostic)]
@@ -25,7 +25,7 @@ struct DeriveSessionDiagnostic {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[note(parser::add_paren)]
 struct Note {
     #[primary_span]
diff --git a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
index fd8128c31f8..80ea9082881 100644
--- a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
+++ b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
@@ -17,7 +17,7 @@ use rustc_span::symbol::Ident;
 use rustc_span::Span;
 
 extern crate rustc_macros;
-use rustc_macros::{Diagnostic, LintDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 
 extern crate rustc_middle;
 use rustc_middle::ty::Ty;
@@ -462,7 +462,7 @@ struct NoApplicability {
     suggestion: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[note(parser::add_paren)]
 struct Note;
 
diff --git a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
index 812ca0c72bd..9fbe7b1f4c8 100644
--- a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
+++ b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
@@ -1,8 +1,8 @@
 // check-fail
-// Tests error conditions for specifying subdiagnostics using #[derive(SessionSubdiagnostic)]
+// Tests error conditions for specifying subdiagnostics using #[derive(Subdiagnostic)]
 
 // The proc_macro2 crate handles spans differently when on beta/stable release rather than nightly,
-// changing the output of this test. Since SessionSubdiagnostic is strictly internal to the compiler
+// changing the output of this test. Since Subdiagnostic is strictly internal to the compiler
 // the test is just ignored on stable and beta:
 // ignore-beta
 // ignore-stable
@@ -17,9 +17,9 @@ extern crate rustc_macros;
 
 use rustc_errors::Applicability;
 use rustc_span::Span;
-use rustc_macros::SessionSubdiagnostic;
+use rustc_macros::Subdiagnostic;
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct A {
     #[primary_span]
@@ -27,7 +27,7 @@ struct A {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum B {
     #[label(parser::add_paren)]
     A {
@@ -43,14 +43,14 @@ enum B {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 //~^ ERROR label without `#[primary_span]` field
 struct C {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label]
 //~^ ERROR `#[label]` is not a valid attribute
 struct D {
@@ -59,7 +59,7 @@ struct D {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[foo]
 //~^ ERROR `#[foo]` is not a valid attribute
 //~^^ ERROR cannot find attribute `foo` in this scope
@@ -69,7 +69,7 @@ struct E {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label = "..."]
 //~^ ERROR `#[label = ...]` is not a valid attribute
 struct F {
@@ -78,7 +78,7 @@ struct F {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(bug = "...")]
 //~^ ERROR `#[label(bug = ...)]` is not a valid attribute
 struct G {
@@ -87,7 +87,7 @@ struct G {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label("...")]
 //~^ ERROR `#[label("...")]` is not a valid attribute
 struct H {
@@ -96,7 +96,7 @@ struct H {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(slug = 4)]
 //~^ ERROR `#[label(slug = ...)]` is not a valid attribute
 struct J {
@@ -105,7 +105,7 @@ struct J {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(slug("..."))]
 //~^ ERROR `#[label(slug(...))]` is not a valid attribute
 struct K {
@@ -114,7 +114,7 @@ struct K {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(slug)]
 //~^ ERROR cannot find value `slug` in module `rustc_errors::fluent`
 //~^^ NOTE not found in `rustc_errors::fluent`
@@ -124,7 +124,7 @@ struct L {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label()]
 //~^ ERROR diagnostic slug must be first argument of a `#[label(...)]` attribute
 struct M {
@@ -133,7 +133,7 @@ struct M {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren, code = "...")]
 //~^ ERROR `code` is not a valid nested attribute of a `label` attribute
 struct N {
@@ -142,7 +142,7 @@ struct N {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren, applicability = "machine-applicable")]
 //~^ ERROR `applicability` is not a valid nested attribute of a `label` attribute
 struct O {
@@ -151,7 +151,7 @@ struct O {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[foo]
 //~^ ERROR cannot find attribute `foo` in this scope
 //~^^ ERROR unsupported type attribute for subdiagnostic enum
@@ -164,7 +164,7 @@ enum P {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum Q {
     #[bar]
     //~^ ERROR `#[bar]` is not a valid attribute
@@ -176,7 +176,7 @@ enum Q {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum R {
     #[bar = "..."]
     //~^ ERROR `#[bar = ...]` is not a valid attribute
@@ -188,7 +188,7 @@ enum R {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum S {
     #[bar = 4]
     //~^ ERROR `#[bar = ...]` is not a valid attribute
@@ -200,7 +200,7 @@ enum S {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum T {
     #[bar("...")]
     //~^ ERROR `#[bar(...)]` is not a valid attribute
@@ -212,7 +212,7 @@ enum T {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum U {
     #[label(code = "...")]
     //~^ ERROR diagnostic slug must be first argument of a `#[label(...)]` attribute
@@ -223,7 +223,7 @@ enum U {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum V {
     #[label(parser::add_paren)]
     A {
@@ -239,7 +239,7 @@ enum V {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 //~^ ERROR label without `#[primary_span]` field
 struct W {
@@ -248,7 +248,7 @@ struct W {
     span: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct X {
     #[primary_span]
@@ -258,7 +258,7 @@ struct X {
     applicability: Applicability,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct Y {
     #[primary_span]
@@ -269,7 +269,7 @@ struct Y {
     bar: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct Z {
     #[primary_span]
@@ -280,7 +280,7 @@ struct Z {
     bar: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct AA {
     #[primary_span]
@@ -291,7 +291,7 @@ struct AA {
     bar: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct AB {
     #[primary_span]
@@ -300,14 +300,14 @@ struct AB {
     z: Z
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 union AC {
 //~^ ERROR unexpected unsupported untagged union
     span: u32,
     b: u64
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 #[label(parser::add_paren)]
 struct AD {
@@ -315,7 +315,7 @@ struct AD {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren, parser::add_paren)]
 //~^ ERROR `#[label(parser::add_paren)]` is not a valid attribute
 struct AE {
@@ -323,7 +323,7 @@ struct AE {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label(parser::add_paren)]
 struct AF {
     #[primary_span]
@@ -334,14 +334,14 @@ struct AF {
     span_b: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 struct AG {
     //~^ ERROR subdiagnostic kind not specified
     #[primary_span]
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 struct AH {
     #[primary_span]
@@ -351,7 +351,7 @@ struct AH {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum AI {
     #[suggestion(parser::add_paren, code = "...")]
     A {
@@ -371,7 +371,7 @@ enum AI {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...", code = "...")]
 //~^ ERROR specified multiple times
 //~^^ NOTE previously specified here
@@ -382,7 +382,7 @@ struct AJ {
     applicability: Applicability,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 struct AK {
     #[primary_span]
@@ -395,7 +395,7 @@ struct AK {
     applicability_b: Applicability,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 struct AL {
     #[primary_span]
@@ -405,14 +405,14 @@ struct AL {
     applicability: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 struct AM {
     #[primary_span]
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren)]
 //~^ ERROR suggestion without `code = "..."`
 struct AN {
@@ -422,7 +422,7 @@ struct AN {
     applicability: Applicability,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code ="...", applicability = "foo")]
 //~^ ERROR invalid applicability
 struct AO {
@@ -430,31 +430,31 @@ struct AO {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[help(parser::add_paren)]
 struct AP {
     var: String
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[note(parser::add_paren)]
 struct AQ;
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 //~^ ERROR suggestion without `#[primary_span]` field
 struct AR {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code ="...", applicability = "machine-applicable")]
 struct AS {
     #[primary_span]
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[label]
 //~^ ERROR unsupported type attribute for subdiagnostic enum
 enum AT {
@@ -466,7 +466,7 @@ enum AT {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
 struct AU {
     #[primary_span]
@@ -474,7 +474,7 @@ struct AU {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
 //~^ ERROR `var` doesn't refer to a field on this type
 struct AV {
@@ -482,7 +482,7 @@ struct AV {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum AW {
     #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
     A {
@@ -492,7 +492,7 @@ enum AW {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 enum AX {
     #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
 //~^ ERROR `var` doesn't refer to a field on this type
@@ -502,18 +502,18 @@ enum AX {
     }
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[warning(parser::add_paren)]
 struct AY {}
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[warning(parser::add_paren)]
 struct AZ {
     #[primary_span]
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[suggestion(parser::add_paren, code = "...")]
 //~^ ERROR suggestion without `#[primary_span]` field
 struct BA {
@@ -528,7 +528,7 @@ struct BA {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, code = "...", applicability = "machine-applicable")]
 //~^ ERROR multipart suggestion without any `#[suggestion_part(...)]` fields
 //~| ERROR `code` is not a valid nested attribute of a `multipart_suggestion` attribute
@@ -536,7 +536,7 @@ struct BBa {
     var: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 struct BBb {
     #[suggestion_part]
@@ -544,7 +544,7 @@ struct BBb {
     span1: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 struct BBc {
     #[suggestion_part()]
@@ -552,7 +552,7 @@ struct BBc {
     span1: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren)]
 //~^ ERROR multipart suggestion without any `#[suggestion_part(...)]` fields
 struct BC {
@@ -561,7 +561,7 @@ struct BC {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren)]
 struct BD {
     #[suggestion_part]
@@ -581,7 +581,7 @@ struct BD {
     s2: String,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 struct BE {
     #[suggestion_part(code = "...", code = ",,,")]
@@ -590,7 +590,7 @@ struct BE {
     span: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 struct BF {
     #[suggestion_part(code = "(")]
@@ -599,7 +599,7 @@ struct BF {
     second: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren)]
 struct BG {
     #[applicability]
@@ -610,7 +610,7 @@ struct BG {
     second: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 //~^ NOTE previously specified here
 struct BH {
@@ -623,7 +623,7 @@ struct BH {
     second: Span,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
 struct BI {
     #[suggestion_part(code = "")]