Rollup merge of rust-lang#144331 - jplatte:matches-allow-non_exhaustive_omitted_patterns, r=Nadrieril

Disable non_exhaustive_omitted_patterns within matches! macro

Closes rust-lang#117304.

I believe I can skip all of the bootstrap stuff mentioned in rust-lang#117304 (comment) due to https://blog.rust-lang.org/inside-rust/2025/05/29/redesigning-the-initial-bootstrap-sequence/, right?

cc `@Jules-Bertholet`

Author: matthiaskrgr

core/src/macros/mod.rs

@@ -426,8 +426,10 @@ pub macro debug_assert_matches($($arg:tt)*) {
 #[macro_export]
 #[stable(feature = "matches_macro", since = "1.42.0")]
 #[rustc_diagnostic_item = "matches_macro"]
+#[allow_internal_unstable(non_exhaustive_omitted_patterns_lint, stmt_expr_attributes)]
 macro_rules! matches {
     ($expression:expr, $pattern:pat $(if $guard:expr)? $(,)?) => {
+        #[allow(non_exhaustive_omitted_patterns)]
         match $expression {
             $pattern $(if $guard)? => true,
             _ => false

coretests/tests/lib.rs

@@ -76,6 +76,7 @@
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(next_index)]
+#![feature(non_exhaustive_omitted_patterns_lint)]
 #![feature(numfmt)]
 #![feature(pattern)]
 #![feature(pointer_is_aligned_to)]

coretests/tests/macros.rs

@@ -213,3 +213,9 @@ fn _expression() {
         }
     );
 }
+
+#[deny(non_exhaustive_omitted_patterns)]
+fn _matches_does_not_trigger_non_exhaustive_omitted_patterns_lint(o: core::sync::atomic::Ordering) {
+    // Ordering is a #[non_exhaustive] enum from a separate crate
+    let _m = matches!(o, core::sync::atomic::Ordering::Relaxed);
+}