Rollup merge of rust-lang#120742 - Nadrieril:use-min_exh_pats, r=compiler-errors

mark `min_exhaustive_patterns` as complete

This is step 1 and 2 of my [proposal](rust-lang#119612 (comment)) to move `min_exhaustive_patterns` forward. The vast majority of in-tree use cases of `exhaustive_patterns` are covered by `min_exhaustive_patterns`. There are a few cases that still require `exhaustive_patterns` in tests and they're all behind references.

r? ``@ghost``

Author: matthiaskrgr

compiler/rustc_feature/src/unstable.rs

@@ -518,7 +518,7 @@ declare_features! (
     (unstable, marker_trait_attr, "1.30.0", Some(29864)),
     /// Allows exhaustive pattern matching on types that contain uninhabited types in cases that are
     /// unambiguously sound.
-    (incomplete, min_exhaustive_patterns, "1.77.0", Some(119612)),
+    (unstable, min_exhaustive_patterns, "1.77.0", Some(119612)),
     /// A minimal, sound subset of specialization intended to be used by the
     /// standard library until the soundness issues with specialization
     /// are fixed.

compiler/rustc_middle/src/lib.rs

@@ -24,6 +24,8 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![cfg_attr(bootstrap, feature(exhaustive_patterns))]
+#![cfg_attr(not(bootstrap), feature(min_exhaustive_patterns))]
 #![feature(rustdoc_internals)]
 #![feature(allocator_api)]
 #![feature(array_windows)]
@@ -32,7 +34,6 @@
 #![feature(core_intrinsics)]
 #![feature(const_type_name)]
 #![feature(discriminant_kind)]
-#![feature(exhaustive_patterns)]
 #![feature(coroutines)]
 #![feature(generic_nonzero)]
 #![feature(if_let_guard)]

compiler/rustc_target/src/lib.rs

@@ -9,9 +9,10 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![cfg_attr(bootstrap, feature(exhaustive_patterns))]
+#![cfg_attr(not(bootstrap), feature(min_exhaustive_patterns))]
 #![feature(rustdoc_internals)]
 #![feature(assert_matches)]
-#![feature(exhaustive_patterns)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![cfg_attr(bootstrap, feature(min_specialization))]

tests/ui/closures/2229_closure_analysis/run_pass/multivariant.min_exhaustive_patterns.stderr

@@ -5,7 +5,6 @@
 //@ run-pass
 #![cfg_attr(exhaustive_patterns, feature(exhaustive_patterns))]
 #![cfg_attr(min_exhaustive_patterns, feature(min_exhaustive_patterns))]
-//[min_exhaustive_patterns]~^ WARN the feature `min_exhaustive_patterns` is incomplete
 #![feature(never_type)]
 
 pub fn main() {

tests/ui/closures/2229_closure_analysis/run_pass/multivariant.rs

@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: type `&!` is non-empty
-  --> $DIR/always-inhabited-union-ref.rs:26:11
+  --> $DIR/always-inhabited-union-ref.rs:25:11
    |
 LL |     match uninhab_ref() {
    |           ^^^^^^^^^^^^^
@@ -14,13 +14,13 @@ LL +     }
    |
 
 error[E0004]: non-exhaustive patterns: type `Foo` is non-empty
-  --> $DIR/always-inhabited-union-ref.rs:30:11
+  --> $DIR/always-inhabited-union-ref.rs:29:11
    |
 LL |     match uninhab_union() {
    |           ^^^^^^^^^^^^^^^
    |
 note: `Foo` defined here
-  --> $DIR/always-inhabited-union-ref.rs:13:11
+  --> $DIR/always-inhabited-union-ref.rs:12:11
    |
 LL | pub union Foo {
    |           ^^^

tests/ui/pattern/usefulness/always-inhabited-union-ref.exhaustive_patterns.stderr

@@ -1,14 +1,5 @@
-warning: the feature `min_exhaustive_patterns` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/always-inhabited-union-ref.rs:7:46
-   |
-LL | #![cfg_attr(min_exhaustive_patterns, feature(min_exhaustive_patterns))]
-   |                                              ^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: see issue #119612 <https://github.com/rust-lang/rust/issues/119612> for more information
-   = note: `#[warn(incomplete_features)]` on by default
-
 error[E0004]: non-exhaustive patterns: type `&!` is non-empty
-  --> $DIR/always-inhabited-union-ref.rs:26:11
+  --> $DIR/always-inhabited-union-ref.rs:25:11
    |
 LL |     match uninhab_ref() {
    |           ^^^^^^^^^^^^^
@@ -23,13 +14,13 @@ LL +     }
    |
 
 error[E0004]: non-exhaustive patterns: type `Foo` is non-empty
-  --> $DIR/always-inhabited-union-ref.rs:30:11
+  --> $DIR/always-inhabited-union-ref.rs:29:11
    |
 LL |     match uninhab_union() {
    |           ^^^^^^^^^^^^^^^
    |
 note: `Foo` defined here
-  --> $DIR/always-inhabited-union-ref.rs:13:11
+  --> $DIR/always-inhabited-union-ref.rs:12:11
    |
 LL | pub union Foo {
    |           ^^^
@@ -41,6 +32,6 @@ LL +         _ => todo!(),
 LL +     }
    |
 
-error: aborting due to 2 previous errors; 1 warning emitted
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0004`.

tests/ui/pattern/usefulness/always-inhabited-union-ref.min_exhaustive_patterns.stderr

@@ -5,7 +5,6 @@
 
 #![cfg_attr(exhaustive_patterns, feature(exhaustive_patterns))]
 #![cfg_attr(min_exhaustive_patterns, feature(min_exhaustive_patterns))]
-//[min_exhaustive_patterns]~^ WARN the feature `min_exhaustive_patterns` is incomplete
 #![feature(never_type)]
 #![allow(dead_code)]
 #![allow(unreachable_code)]