rust-lang · cuviper · Apr 8, 2026 · Apr 8, 2026 · Apr 8, 2026 · Apr 8, 2026
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![cfg_attr(all(feature = "nightly", bootstrap, test), feature(assert_matches))]
+#![cfg_attr(all(feature = "nightly", test), feature(assert_matches))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
 #![cfg_attr(feature = "nightly", feature(step_trait))]

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -545,6 +545,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     }
 
     // for dbg!(x) which may take ownership, suggest dbg!(&x) instead
+    // but here we actually do not check whether the macro name is `dbg!`
+    // so that we may extend the scope a bit larger to cover more cases
     fn suggest_ref_for_dbg_args(
         &self,
         body: &hir::Expr<'_>,
@@ -558,41 +560,29 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         });
         let Some(var_info) = var_info else { return };
         let arg_name = var_info.name;
-        struct MatchArgFinder<'tcx> {
-            tcx: TyCtxt<'tcx>,
-            move_span: Span,
+        struct MatchArgFinder {
+            expr_span: Span,
+            match_arg_span: Option<Span>,
             arg_name: Symbol,
-            match_arg_span: Option<Span> = None,
         }
-        impl Visitor<'_> for MatchArgFinder<'_> {
+        impl Visitor<'_> for MatchArgFinder {
             fn visit_expr(&mut self, e: &hir::Expr<'_>) {
                 // dbg! is expanded into a match pattern, we need to find the right argument span
-                if let hir::ExprKind::Match(scrutinee, ..) = &e.kind
-                    && let hir::ExprKind::Tup(args) = scrutinee.kind
-                    && e.span.macro_backtrace().any(|expn| {
-                        expn.macro_def_id.is_some_and(|macro_def_id| {
-                            self.tcx.is_diagnostic_item(sym::dbg_macro, macro_def_id)
-                        })
-                    })
+                if let hir::ExprKind::Match(expr, ..) = &e.kind
+                    && let hir::ExprKind::Path(hir::QPath::Resolved(
+                        _,
+                        path @ Path { segments: [seg], .. },
+                    )) = &expr.kind
+                    && seg.ident.name == self.arg_name
+                    && self.expr_span.source_callsite().contains(expr.span)
                 {
-                    for arg in args {
-                        if let hir::ExprKind::Path(hir::QPath::Resolved(
-                            _,
-                            path @ Path { segments: [seg], .. },
-                        )) = &arg.kind
-                            && seg.ident.name == self.arg_name
-                            && self.move_span.source_equal(arg.span)
-                        {
-                            self.match_arg_span = Some(path.span);
-                            return;
-                        }
-                    }
+                    self.match_arg_span = Some(path.span);
                 }
                 hir::intravisit::walk_expr(self, e);
             }
         }
 
-        let mut finder = MatchArgFinder { tcx: self.infcx.tcx, move_span, arg_name, .. };
+        let mut finder = MatchArgFinder { expr_span: move_span, match_arg_span: None, arg_name };
         finder.visit_expr(body);
         if let Some(macro_arg_span) = finder.match_arg_span {
             err.span_suggestion_verbose(

diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
@@ -2,8 +2,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]
 #![feature(file_buffered)]

diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
@@ -3,8 +3,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(iter_order_by)]

diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -5,8 +5,8 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
 #![feature(impl_trait_in_assoc_type)]

diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(negative_impls)]

diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs
@@ -1,7 +1,7 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(array_try_map)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(never_type)]

diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
@@ -10,14 +10,14 @@
 #![allow(internal_features)]
 #![allow(rustc::default_hash_types)]
 #![allow(rustc::potential_query_instability)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(cfg_select))]
 #![cfg_attr(bootstrap, feature(cold_path))]
 #![cfg_attr(test, feature(test))]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![feature(allocator_api)]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
+#![feature(assert_matches)]
 #![feature(auto_traits)]
 #![feature(const_default)]
 #![feature(const_trait_impl)]

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
@@ -5,7 +5,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
@@ -56,8 +56,8 @@ This API is completely unstable and subject to change.
 */
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(default_field_values)]
 #![feature(gen_blocks)]
 #![feature(iter_intersperse)]

diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(iter_intersperse)]
 #![feature(iter_order_by)]

diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
@@ -14,7 +14,7 @@
 
 // tidy-alphabetical-start
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
+#![feature(assert_matches)]
 #![feature(extend_one)]
 #![recursion_limit = "512"] // For rustdoc
 // tidy-alphabetical-end

diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
@@ -21,8 +21,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(iter_order_by)]
 #![feature(rustc_attrs)]

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
@@ -27,10 +27,10 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![cfg_attr(doc, feature(intra_doc_pointers))]
 #![feature(allocator_api)]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_as_ptr)]
 #![feature(box_patterns)]

diff --git a/compiler/rustc_mir_build/src/lib.rs b/compiler/rustc_mir_build/src/lib.rs
@@ -1,8 +1,8 @@
 //! Construction of MIR from HIR.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end

diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]

diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(const_type_name)]
 #![feature(cow_is_borrowed)]

diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
@@ -1,9 +1,9 @@
 //! The main parser interface.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![cfg_attr(test, feature(iter_order_by))]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
@@ -8,10 +8,10 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![cfg_attr(bootstrap, feature(ptr_as_ref_unchecked))]
 #![feature(arbitrary_self_types)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(const_default)]
 #![feature(const_trait_impl)]

diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
@@ -763,7 +763,6 @@ symbols! {
         custom_test_frameworks,
         d,
         d32,
-        dbg_macro,
         dead_code,
         dealloc,
         debug,

diff --git a/compiler/rustc_symbol_mangling/src/lib.rs b/compiler/rustc_symbol_mangling/src/lib.rs
@@ -88,7 +88,7 @@
 //! DefPaths which are much more robust in the face of changes to the code base.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
+#![feature(assert_matches)]
 // tidy-alphabetical-end
 
 use rustc_hir::def::DefKind;

diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
@@ -11,8 +11,8 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_ty_utils/src/lib.rs b/compiler/rustc_ty_utils/src/lib.rs
@@ -5,8 +5,8 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![cfg_attr(bootstrap, feature(assert_matches))]
 #![cfg_attr(bootstrap, feature(if_let_guard))]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(iterator_try_collect)]

diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
@@ -89,6 +89,7 @@
 #![feature(allocator_api)]
 #![feature(array_into_iter_constructors)]
 #![feature(ascii_char)]
+#![feature(assert_matches)]
 #![feature(async_fn_traits)]
 #![feature(async_iterator)]
 #![feature(bstr)]

diff --git a/library/alloctests/lib.rs b/library/alloctests/lib.rs
@@ -16,6 +16,7 @@
 // tidy-alphabetical-start
 #![feature(allocator_api)]
 #![feature(array_into_iter_constructors)]
+#![feature(assert_matches)]
 #![feature(char_internals)]
 #![feature(const_alloc_error)]
 #![feature(const_cmp)]

diff --git a/library/alloctests/tests/lib.rs b/library/alloctests/tests/lib.rs
@@ -4,6 +4,7 @@
 #![feature(const_heap)]
 #![feature(deque_extend_front)]
 #![feature(iter_array_chunks)]
+#![feature(assert_matches)]
 #![feature(cow_is_borrowed)]
 #![feature(core_intrinsics)]
 #![feature(downcast_unchecked)]

diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
@@ -205,7 +205,7 @@ use prelude::rust_2024::*;
 #[macro_use]
 mod macros;
 
-#[stable(feature = "assert_matches", since = "1.95.0")]
+#[unstable(feature = "assert_matches", issue = "82775")]
 pub use crate::macros::{assert_matches, debug_assert_matches};
 
 #[unstable(feature = "derive_from", issue = "144889")]

diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
@@ -147,6 +147,8 @@ macro_rules! assert_ne {
 /// # Examples
 ///
 /// ```
+/// #![feature(assert_matches)]
+///
 /// use std::assert_matches;
 ///
 /// let a = Some(345);
@@ -164,7 +166,7 @@ macro_rules! assert_ne {
 /// assert_matches!(a, Some(x) if x > 100);
 /// // assert_matches!(a, Some(x) if x < 100); // panics
 /// ```
-#[stable(feature = "assert_matches", since = "1.95.0")]
+#[unstable(feature = "assert_matches", issue = "82775")]
 #[allow_internal_unstable(panic_internals)]
 #[rustc_macro_transparency = "semiopaque"]
 pub macro assert_matches {
@@ -374,6 +376,8 @@ macro_rules! debug_assert_ne {
 /// # Examples
 ///
 /// ```
+/// #![feature(assert_matches)]
+///
 /// use std::debug_assert_matches;
 ///
 /// let a = Some(345);
@@ -391,7 +395,7 @@ macro_rules! debug_assert_ne {
 /// debug_assert_matches!(a, Some(x) if x > 100);
 /// // debug_assert_matches!(a, Some(x) if x < 100); // panics
 /// ```
-#[stable(feature = "assert_matches", since = "1.95.0")]
+#[unstable(feature = "assert_matches", issue = "82775")]
 #[allow_internal_unstable(assert_matches)]
 #[rustc_macro_transparency = "semiopaque"]
 pub macro debug_assert_matches($($arg:tt)*) {

diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
@@ -393,6 +393,7 @@
 //
 // Only for re-exporting:
 // tidy-alphabetical-start
+#![feature(assert_matches)]
 #![feature(async_iterator)]
 #![feature(c_variadic)]
 #![feature(cfg_accessible)]
@@ -468,9 +469,7 @@ extern crate std as realstd;
 
 // The standard macros that are not built-in to the compiler.
 #[macro_use]
-#[doc(hidden)]
-#[unstable(feature = "std_internals", issue = "none")]
-pub mod macros;
+mod macros;
 
 // The runtime entry point and a few unstable public functions used by the
 // compiler
@@ -724,7 +723,7 @@ pub use core::{
     assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, r#try, unimplemented,
     unreachable, write, writeln,
 };
-#[stable(feature = "assert_matches", since = "1.95.0")]
+#[unstable(feature = "assert_matches", issue = "82775")]
 pub use core::{assert_matches, debug_assert_matches};
 
 // Re-export unstable derive macro defined through core.