Re-register unsized_const_params as language feature to bring back the warning

tiif · tiif · commit 6004916b7e7a · 2025-09-12T07:53:35.000Z
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -661,6 +661,9 @@ declare_features! (
     (incomplete, unsafe_binders, "1.85.0", Some(130516)),
     /// Allows declaring fields `unsafe`.
     (incomplete, unsafe_fields, "1.85.0", Some(132922)),
+    /// Allows const generic parameters to be defined with types that
+    /// are not `Sized`, e.g. `fn foo<const N: [u8]>() {`.
+    (incomplete, unsized_const_params, "1.82.0", Some(95174)),
     /// Allows unsized fn parameters.
     (internal, unsized_fn_params, "1.49.0", Some(48055)),
     /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute.
diff --git a/tests/ui/coherence/negative-coherence/regions-in-canonical.rs b/tests/ui/coherence/negative-coherence/regions-in-canonical.rs
@@ -1,6 +1,7 @@
 //@ check-pass
 
 #![feature(adt_const_params, unsized_const_params)]
+//~^ WARN the feature `unsized_const_params` is incomplete
 #![feature(with_negative_coherence, negative_impls)]
 
 pub trait A<const K: &'static str> {}
diff --git a/tests/ui/coherence/negative-coherence/regions-in-canonical.stderr b/tests/ui/coherence/negative-coherence/regions-in-canonical.stderr
@@ -0,0 +1,11 @@
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/regions-in-canonical.rs:3:30
+   |
+LL | #![feature(adt_const_params, unsized_const_params)]
+   |                              ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/const-generics/defaults/concrete-const-param-type.rs b/tests/ui/const-generics/defaults/concrete-const-param-type.rs
@@ -1,5 +1,6 @@
 #![feature(generic_const_parameter_types, unsized_const_params, adt_const_params)]
 //~^ WARN the feature `generic_const_parameter_types` is incomplete
+//~^^ WARN the feature `unsized_const_params` is incomplete
 // Make sure that we test the const param type of default const parameters
 // if both the type of the default and the type of the parameter are concrete.
 
diff --git a/tests/ui/const-generics/defaults/concrete-const-param-type.stderr b/tests/ui/const-generics/defaults/concrete-const-param-type.stderr
@@ -7,11 +7,19 @@ LL | #![feature(generic_const_parameter_types, unsized_const_params, adt_const_p
    = note: see issue #137626 <https://github.com/rust-lang/rust/issues/137626> for more information
    = note: `#[warn(incomplete_features)]` on by default
 
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/concrete-const-param-type.rs:1:43
+   |
+LL | #![feature(generic_const_parameter_types, unsized_const_params, adt_const_params)]
+   |                                           ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+
 error: the constant `N` is not of type `u64`
-  --> $DIR/concrete-const-param-type.rs:8:26
+  --> $DIR/concrete-const-param-type.rs:9:26
    |
 LL | struct Foo<const N: u32, const M: u64 = N>;
    |                          ^^^^^^^^^^^^^^^^ expected `u64`, found `u32`
 
-error: aborting due to 1 previous error; 1 warning emitted
+error: aborting due to 1 previous error; 2 warnings emitted
 
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-1.rs b/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-1.rs
@@ -2,6 +2,7 @@
 
 #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
 //~^ WARN the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes [incomplete_features]
+//~^^ WARN the feature `unsized_const_params` is incomplete
 
 pub struct Changes<const CHANGES: &'static [&'static str]>
 where
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-1.stderr b/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-1.stderr
@@ -1,11 +1,19 @@
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/issue-97047-ice-1.rs:3:30
+   |
+LL | #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
+   |                              ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/issue-97047-ice-1.rs:3:52
    |
 LL | #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
    |                                                    ^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
-   = note: `#[warn(incomplete_features)]` on by default
 
-warning: 1 warning emitted
+warning: 2 warnings emitted
 
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-2.rs b/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-2.rs
@@ -2,6 +2,7 @@
 
 #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
 //~^ WARN the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes [incomplete_features]
+//~^^ WARN the feature `unsized_const_params` is incomplete
 
 pub struct Changes<const CHANGES: &'static [&'static str]>
 where
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-2.stderr b/tests/ui/const-generics/generic_const_exprs/issue-97047-ice-2.stderr
@@ -1,11 +1,19 @@
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/issue-97047-ice-2.rs:3:30
+   |
+LL | #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
+   |                              ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/issue-97047-ice-2.rs:3:52
    |
 LL | #![feature(adt_const_params, unsized_const_params, generic_const_exprs)]
    |                                                    ^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
-   = note: `#[warn(incomplete_features)]` on by default
 
-warning: 1 warning emitted
+warning: 2 warnings emitted
 
diff --git a/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.rs b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.rs
@@ -2,6 +2,7 @@
 
 #![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)]
 //~^ WARN the feature `generic_const_parameter_types` is incomplete
+//~^^ WARN the feature `unsized_const_params` is incomplete
 
 fn foo<'a, const N: &'a u32>() {
     let b: &'static u32 = N;
diff --git a/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.stderr b/tests/ui/const-generics/generic_const_parameter_types/check-type-in-mir.stderr
@@ -1,19 +1,27 @@
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/check-type-in-mir.rs:3:12
+   |
+LL | #![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)]
+   |            ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 warning: the feature `generic_const_parameter_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/check-type-in-mir.rs:3:52
    |
 LL | #![feature(unsized_const_params, adt_const_params, generic_const_parameter_types)]
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #137626 <https://github.com/rust-lang/rust/issues/137626> for more information
-   = note: `#[warn(incomplete_features)]` on by default
 
 error: lifetime may not live long enough
-  --> $DIR/check-type-in-mir.rs:7:12
+  --> $DIR/check-type-in-mir.rs:8:12
    |
 LL | fn foo<'a, const N: &'a u32>() {
    |        -- lifetime `'a` defined here
 LL |     let b: &'static u32 = N;
    |            ^^^^^^^^^^^^ type annotation requires that `'a` must outlive `'static`
 
-error: aborting due to 1 previous error; 1 warning emitted
+error: aborting due to 1 previous error; 2 warnings emitted
 
diff --git a/tests/ui/consts/refs_check_const_eq-issue-88384.rs b/tests/ui/consts/refs_check_const_eq-issue-88384.rs
@@ -1,5 +1,6 @@
 #![feature(fn_traits)]
 #![feature(adt_const_params, unsized_const_params)]
+//~^ WARN the feature `unsized_const_params` is incomplete
 
 #[derive(PartialEq, Eq)]
 struct CompileTimeSettings {
diff --git a/tests/ui/consts/refs_check_const_eq-issue-88384.stderr b/tests/ui/consts/refs_check_const_eq-issue-88384.stderr
@@ -1,5 +1,14 @@
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/refs_check_const_eq-issue-88384.rs:2:30
+   |
+LL | #![feature(adt_const_params, unsized_const_params)]
+   |                              ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0741]: `CompileTimeSettings` must implement `ConstParamTy` to be used as the type of a const generic parameter
-  --> $DIR/refs_check_const_eq-issue-88384.rs:9:21
+  --> $DIR/refs_check_const_eq-issue-88384.rs:10:21
    |
 LL | struct Foo<const T: CompileTimeSettings>;
    |                     ^^^^^^^^^^^^^^^^^^^
@@ -11,7 +20,7 @@ LL + #[derive(ConstParamTy)]
    |
 
 error[E0741]: `CompileTimeSettings` must implement `ConstParamTy` to be used as the type of a const generic parameter
-  --> $DIR/refs_check_const_eq-issue-88384.rs:12:15
+  --> $DIR/refs_check_const_eq-issue-88384.rs:13:15
    |
 LL | impl<const T: CompileTimeSettings> Foo<T> {
    |               ^^^^^^^^^^^^^^^^^^^
@@ -22,6 +31,6 @@ LL - struct CompileTimeSettings {
 LL + #[derive(ConstParamTy)]
    |
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0741`.
diff --git a/tests/ui/error-codes/E0771.rs b/tests/ui/error-codes/E0771.rs
@@ -1,4 +1,5 @@
 #![feature(adt_const_params, unsized_const_params)]
+//~^ WARN the feature `unsized_const_params` is incomplete
 
 fn function_with_str<'a, const STRING: &'a str>() {} //~ ERROR E0770
 
diff --git a/tests/ui/error-codes/E0771.stderr b/tests/ui/error-codes/E0771.stderr
@@ -1,9 +1,18 @@
 error[E0770]: the type of const parameters must not depend on other generic parameters
-  --> $DIR/E0771.rs:3:41
+  --> $DIR/E0771.rs:4:41
    |
 LL | fn function_with_str<'a, const STRING: &'a str>() {}
    |                                         ^^ the type must not depend on the parameter `'a`
 
-error: aborting due to 1 previous error
+warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/E0771.rs:1:30
+   |
+LL | #![feature(adt_const_params, unsized_const_params)]
+   |                              ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #95174 <https://github.com/rust-lang/rust/issues/95174> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0770`.
