rust-lang · rust-bors · Jun 14, 2026 · Jun 5, 2026 · Jun 14, 2026 · Jun 14, 2026
diff --git a/compiler/rustc_attr_parsing/src/attributes/diagnostic/mod.rs b/compiler/rustc_attr_parsing/src/attributes/diagnostic/mod.rs
@@ -27,7 +27,7 @@ pub(crate) mod on_move;
 pub(crate) mod on_type_error;
 pub(crate) mod on_unimplemented;
 pub(crate) mod on_unknown;
-pub(crate) mod on_unmatch_args;
+pub(crate) mod on_unmatched_args;
 
 #[derive(Copy, Clone)]
 pub(crate) enum Mode {
@@ -41,8 +41,8 @@ pub(crate) enum Mode {
     DiagnosticOnMove,
     /// `#[diagnostic::on_unknown]`
     DiagnosticOnUnknown,
-    /// `#[diagnostic::on_unmatch_args]`
-    DiagnosticOnUnmatchArgs,
+    /// `#[diagnostic::on_unmatched_args]`
+    DiagnosticOnUnmatchedArgs,
     /// `#[diagnostic::on_type_error]`
     DiagnosticOnTypeError,
 }
@@ -55,7 +55,7 @@ impl Mode {
             Self::DiagnosticOnConst => "diagnostic::on_const",
             Self::DiagnosticOnMove => "diagnostic::on_move",
             Self::DiagnosticOnUnknown => "diagnostic::on_unknown",
-            Self::DiagnosticOnUnmatchArgs => "diagnostic::on_unmatch_args",
+            Self::DiagnosticOnUnmatchedArgs => "diagnostic::on_unmatched_args",
             Self::DiagnosticOnTypeError => "diagnostic::on_type_error",
         }
     }
@@ -73,7 +73,7 @@ impl Mode {
             Self::DiagnosticOnConst => DEFAULT,
             Self::DiagnosticOnMove => DEFAULT,
             Self::DiagnosticOnUnknown => DEFAULT,
-            Self::DiagnosticOnUnmatchArgs => DEFAULT,
+            Self::DiagnosticOnUnmatchedArgs => DEFAULT,
             Self::DiagnosticOnTypeError => DIAGNOSTIC_ON_TYPE_ERROR_EXPECTED_OPTIONS,
         }
     }
@@ -90,7 +90,7 @@ impl Mode {
             Self::DiagnosticOnConst => DEFAULT,
             Self::DiagnosticOnMove => DEFAULT,
             Self::DiagnosticOnUnknown => DEFAULT,
-            Self::DiagnosticOnUnmatchArgs => DEFAULT,
+            Self::DiagnosticOnUnmatchedArgs => DEFAULT,
             Self::DiagnosticOnTypeError => DIAGNOSTIC_ON_TYPE_ERROR_ALLOWED_OPTIONS,
         }
     }
@@ -112,7 +112,7 @@ impl Mode {
             Self::DiagnosticOnUnknown => {
                 "only `This` is allowed as a format argument, referring to the failed import"
             }
-            Self::DiagnosticOnUnmatchArgs => {
+            Self::DiagnosticOnUnmatchedArgs => {
                 "only `This` is allowed as a format argument, referring to the macro's name"
             }
             Self::DiagnosticOnTypeError => {
@@ -313,7 +313,7 @@ fn parse_directive_items<'p>(
                 | Mode::DiagnosticOnConst
                 | Mode::DiagnosticOnMove
                 | Mode::DiagnosticOnUnknown
-                | Mode::DiagnosticOnUnmatchArgs,
+                | Mode::DiagnosticOnUnmatchedArgs,
                 sym::message,
             ) => {
                 let value = or_malformed!(value?);
@@ -329,7 +329,7 @@ fn parse_directive_items<'p>(
                 | Mode::DiagnosticOnConst
                 | Mode::DiagnosticOnMove
                 | Mode::DiagnosticOnUnknown
-                | Mode::DiagnosticOnUnmatchArgs,
+                | Mode::DiagnosticOnUnmatchedArgs,
                 sym::label,
             ) => {
                 let value = or_malformed!(value?);
@@ -469,7 +469,7 @@ fn parse_arg(
             (
                 Mode::DiagnosticOnUnknown
                 | Mode::DiagnosticOnMove
-                | Mode::DiagnosticOnUnmatchArgs
+                | Mode::DiagnosticOnUnmatchedArgs
                 | Mode::DiagnosticOnTypeError,
                 sym::This,
             ) => FormatArg::This,
@@ -502,7 +502,7 @@ fn parse_arg(
             ) => FormatArg::GenericParam { generic_param, span },
 
             // Generics are explicitly not allowed, we print those back as is.
-            (Mode::DiagnosticOnUnknown | Mode::DiagnosticOnUnmatchArgs, as_is) => {
+            (Mode::DiagnosticOnUnknown | Mode::DiagnosticOnUnmatchedArgs, as_is) => {
                 warnings.push(FormatWarning::DisallowedPlaceholder {
                     span,
                     attr: mode.as_str(),

diff --git a/.../attributes/diagnostic/on_unmatch_args.rs → ...ttributes/diagnostic/on_unmatched_args.rs b/.../attributes/diagnostic/on_unmatch_args.rs → ...ttributes/diagnostic/on_unmatched_args.rs
@@ -4,21 +4,21 @@ use rustc_session::lint::builtin::MISPLACED_DIAGNOSTIC_ATTRIBUTES;
 
 use crate::attributes::diagnostic::*;
 use crate::attributes::prelude::*;
-use crate::diagnostics::DiagnosticOnUnmatchArgsOnlyForMacros;
+use crate::diagnostics::DiagnosticOnUnmatchedArgsOnlyForMacros;
 
 #[derive(Default)]
-pub(crate) struct OnUnmatchArgsParser {
+pub(crate) struct OnUnmatchedArgsParser {
     span: Option<Span>,
     directive: Option<(Span, Directive)>,
 }
 
-impl AttributeParser for OnUnmatchArgsParser {
+impl AttributeParser for OnUnmatchedArgsParser {
     const ATTRIBUTES: AcceptMapping<Self> = &[(
-        &[sym::diagnostic, sym::on_unmatch_args],
+        &[sym::diagnostic, sym::on_unmatched_args],
         template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
         AttributeStability::Stable, // Unstable, stability checked manually in the parser
         |this, cx, args| {
-            if !cx.features().diagnostic_on_unmatch_args() {
+            if !cx.features().diagnostic_on_unmatched_args() {
                 return;
             }
 
@@ -28,13 +28,13 @@ impl AttributeParser for OnUnmatchArgsParser {
             if !matches!(cx.target, Target::MacroDef) {
                 cx.emit_lint(
                     MISPLACED_DIAGNOSTIC_ATTRIBUTES,
-                    DiagnosticOnUnmatchArgsOnlyForMacros,
+                    DiagnosticOnUnmatchedArgsOnlyForMacros,
                     span,
                 );
                 return;
             }
 
-            let mode = Mode::DiagnosticOnUnmatchArgs;
+            let mode = Mode::DiagnosticOnUnmatchedArgs;
             let Some(items) = parse_list(cx, args, mode) else { return };
 
             let Some(directive) = parse_directive_items(cx, mode, items.mixed(), true) else {
@@ -48,7 +48,9 @@ impl AttributeParser for OnUnmatchArgsParser {
 
     fn finalize(self, _cx: &FinalizeContext<'_, '_>) -> Option<AttributeKind> {
         if let Some(_span) = self.span {
-            Some(AttributeKind::OnUnmatchArgs { directive: self.directive.map(|d| Box::new(d.1)) })
+            Some(AttributeKind::OnUnmatchedArgs {
+                directive: self.directive.map(|d| Box::new(d.1)),
+            })
         } else {
             None
         }

diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
@@ -35,7 +35,7 @@ use crate::attributes::diagnostic::on_move::*;
 use crate::attributes::diagnostic::on_type_error::*;
 use crate::attributes::diagnostic::on_unimplemented::*;
 use crate::attributes::diagnostic::on_unknown::*;
-use crate::attributes::diagnostic::on_unmatch_args::*;
+use crate::attributes::diagnostic::on_unmatched_args::*;
 use crate::attributes::doc::*;
 use crate::attributes::dummy::*;
 use crate::attributes::inline::*;
@@ -149,7 +149,7 @@ attribute_parsers!(
         OnTypeErrorParser,
         OnUnimplementedParser,
         OnUnknownParser,
-        OnUnmatchArgsParser,
+        OnUnmatchedArgsParser,
         RustcAlignParser,
         RustcAlignStaticParser,
         RustcCguTestAttributeParser,

diff --git a/compiler/rustc_attr_parsing/src/diagnostics.rs b/compiler/rustc_attr_parsing/src/diagnostics.rs
@@ -302,8 +302,8 @@ pub(crate) struct DiagnosticOnUnknownOnlyForImports {
 }
 
 #[derive(Diagnostic)]
-#[diag("`#[diagnostic::on_unmatch_args]` can only be applied to macro definitions")]
-pub(crate) struct DiagnosticOnUnmatchArgsOnlyForMacros;
+#[diag("`#[diagnostic::on_unmatched_args]` can only be applied to macro definitions")]
+pub(crate) struct DiagnosticOnUnmatchedArgsOnlyForMacros;
 
 #[derive(Diagnostic)]
 #[diag("`#[diagnostic::on_type_error]` can only be applied to enums, structs or unions")]

diff --git a/compiler/rustc_borrowck/src/diagnostics/opaque_types.rs b/compiler/rustc_borrowck/src/diagnostics/opaque_types.rs
@@ -12,8 +12,8 @@ use rustc_middle::ty::{
     Unnormalized,
 };
 use rustc_span::Span;
+use rustc_trait_selection::diagnostics::impl_trait_overcapture_suggestion;
 use rustc_trait_selection::error_reporting::infer::region::unexpected_hidden_region_diagnostic;
-use rustc_trait_selection::errors::impl_trait_overcapture_suggestion;
 
 use crate::MirBorrowckCtxt;
 use crate::borrow_set::BorrowData;

diff --git a/compiler/rustc_expand/src/mbe/diagnostics.rs b/compiler/rustc_expand/src/mbe/diagnostics.rs
@@ -33,7 +33,7 @@ pub(super) fn failed_to_match_macro(
     args: FailedMacro<'_>,
     body: &TokenStream,
     rules: &[MacroRule],
-    on_unmatch_args: Option<&Directive>,
+    on_unmatched_args: Option<&Directive>,
 ) -> (Span, ErrorGuaranteed) {
     debug!("failed to match macro");
     let def_head_span = if !def_span.is_dummy() && !psess.source_map().is_imported(def_span) {
@@ -77,7 +77,7 @@ pub(super) fn failed_to_match_macro(
     let CustomDiagnostic {
         message: custom_message, label: custom_label, notes: custom_notes, ..
     } = {
-        on_unmatch_args
+        on_unmatched_args
             .map(|directive| directive.eval(None, &FormatArgs { this: name.to_string(), .. }))
             .unwrap_or_default()
     };

diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -166,7 +166,7 @@ pub struct MacroRulesMacroExpander {
     node_id: NodeId,
     name: Ident,
     span: Span,
-    on_unmatch_args: Option<Directive>,
+    on_unmatched_args: Option<Directive>,
     transparency: Transparency,
     kinds: MacroKinds,
     rules: Vec<MacroRule>,
@@ -249,7 +249,7 @@ impl MacroRulesMacroExpander {
                     FailedMacro::Derive,
                     body,
                     rules,
-                    self.on_unmatch_args.as_ref(),
+                    self.on_unmatched_args.as_ref(),
                 );
                 cx.macro_error_and_trace_macros_diag();
                 Err(guar)
@@ -274,7 +274,7 @@ impl TTMacroExpander for MacroRulesMacroExpander {
             self.transparency,
             input,
             &self.rules,
-            self.on_unmatch_args.as_ref(),
+            self.on_unmatched_args.as_ref(),
         ))
     }
 }
@@ -309,7 +309,7 @@ impl AttrProcMacro for MacroRulesMacroExpander {
             args,
             body,
             &self.rules,
-            self.on_unmatch_args.as_ref(),
+            self.on_unmatched_args.as_ref(),
         )
     }
 }
@@ -371,7 +371,7 @@ impl<'matcher> Tracker<'matcher> for NoopTracker {
 }
 
 /// Expands the rules based macro defined by `rules` for a given input `arg`.
-#[instrument(skip(cx, transparency, arg, rules, on_unmatch_args))]
+#[instrument(skip(cx, transparency, arg, rules, on_unmatched_args))]
 fn expand_macro<'cx, 'a: 'cx>(
     cx: &'cx mut ExtCtxt<'_>,
     sp: Span,
@@ -381,7 +381,7 @@ fn expand_macro<'cx, 'a: 'cx>(
     transparency: Transparency,
     arg: TokenStream,
     rules: &'a [MacroRule],
-    on_unmatch_args: Option<&Directive>,
+    on_unmatched_args: Option<&Directive>,
 ) -> Box<dyn MacResult + 'cx> {
     let psess = &cx.sess.psess;
 
@@ -440,7 +440,7 @@ fn expand_macro<'cx, 'a: 'cx>(
                 FailedMacro::Func,
                 &arg,
                 rules,
-                on_unmatch_args,
+                on_unmatched_args,
             );
             cx.macro_error_and_trace_macros_diag();
             DummyResult::any(span, guar)
@@ -449,7 +449,7 @@ fn expand_macro<'cx, 'a: 'cx>(
 }
 
 /// Expands the rules based macro defined by `rules` for a given attribute `args` and `body`.
-#[instrument(skip(cx, transparency, args, body, rules, on_unmatch_args))]
+#[instrument(skip(cx, transparency, args, body, rules, on_unmatched_args))]
 fn expand_macro_attr(
     cx: &mut ExtCtxt<'_>,
     sp: Span,
@@ -461,7 +461,7 @@ fn expand_macro_attr(
     args: TokenStream,
     body: TokenStream,
     rules: &[MacroRule],
-    on_unmatch_args: Option<&Directive>,
+    on_unmatched_args: Option<&Directive>,
 ) -> Result<TokenStream, ErrorGuaranteed> {
     let psess = &cx.sess.psess;
     // Macros defined in the current crate have a real node id,
@@ -526,7 +526,7 @@ fn expand_macro_attr(
                 FailedMacro::Attr(&args),
                 &body,
                 rules,
-                on_unmatch_args,
+                on_unmatched_args,
             );
             cx.trace_macros_diag();
             Err(guar)
@@ -865,9 +865,9 @@ pub fn compile_declarative_macro(
         return dummy_syn_ext(guar);
     }
 
-    let on_unmatch_args = find_attr!(
+    let on_unmatched_args = find_attr!(
         attrs,
-        OnUnmatchArgs { directive, .. } => directive.clone()
+        OnUnmatchedArgs { directive, .. } => directive.clone()
     )
     .flatten()
     .map(|directive| *directive);
@@ -877,7 +877,7 @@ pub fn compile_declarative_macro(
         kinds,
         span,
         node_id,
-        on_unmatch_args,
+        on_unmatched_args,
         transparency,
         rules,
         macro_rules,

diff --git a/compiler/rustc_feature/src/removed.rs b/compiler/rustc_feature/src/removed.rs
@@ -106,6 +106,8 @@ declare_features! (
     (removed, deprecated_safe, "1.95.0", Some(94978), Some("never properly implemented, in the way of attribute refactor"), 152554),
     /// Allows deriving traits as per `SmartPointer` specification
     (removed, derive_smart_pointer, "1.84.0", Some(123430), Some("replaced by `CoercePointee`"), 131284),
+    /// Allows macros to customize macro argument matcher diagnostics.
+    (removed, diagnostic_on_unmatch_args, "CURRENT_RUSTC_VERSION", Some(155642), Some("renamed to `diagnostic_on_unmatched_args`"), 157887),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
     (removed, doc_auto_cfg, "1.92.0", Some(43781), Some("merged into `doc_cfg`"), 138907),
     /// Allows `#[doc(cfg_hide(...))]`.

diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -515,7 +515,7 @@ declare_features! (
     /// Allows giving unresolved imports a custom diagnostic message
     (unstable, diagnostic_on_unknown, "1.96.0", Some(152900)),
     /// Allows macros to customize macro argument matcher diagnostics.
-    (unstable, diagnostic_on_unmatch_args, "1.97.0", Some(155642)),
+    (unstable, diagnostic_on_unmatched_args, "1.97.0", Some(155642)),
     /// Allows `#[doc(cfg(...))]`.
     (unstable, doc_cfg, "1.21.0", Some(43781)),
     /// Allows `#[doc(masked)]`.

diff --git a/compiler/rustc_hir/src/attrs/data_structures.rs b/compiler/rustc_hir/src/attrs/data_structures.rs
@@ -1191,8 +1191,8 @@ pub enum AttributeKind {
         directive: Option<Box<Directive>>,
     },
 
-    /// Represents `#[diagnostic::on_unmatch_args]`.
-    OnUnmatchArgs {
+    /// Represents `#[diagnostic::on_unmatched_args]`.
+    OnUnmatchedArgs {
         /// None if the directive was malformed in some way.
         directive: Option<Box<Directive>>,
     },

diff --git a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
@@ -81,7 +81,7 @@ impl AttributeKind {
             OnTypeError { .. } => Yes,
             OnUnimplemented { .. } => Yes,
             OnUnknown { .. } => Yes,
-            OnUnmatchArgs { .. } => Yes,
+            OnUnmatchedArgs { .. } => Yes,
             Optimize(..) => No,
             PanicRuntime => No,
             PatchableFunctionEntry { .. } => Yes,