Rollup merge of rust-lang#65794 - Centril:unimpl-internal, r=varkor

gate rustc_on_unimplemented under rustc_attrs

Move `rustc_on_implemented` from the `on_implemented` gate to `rustc_attrs` as it is internal.

Closes rust-lang#29628

r? @varkor

src/liballoc/lib.rs

@@ -116,7 +116,7 @@
 #![feature(unsize)]
 #![feature(unsized_locals)]
 #![feature(allocator_internals)]
-#![feature(on_unimplemented)]
+#![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(rustc_const_unstable)]
 #![feature(slice_partition_dedup)]
 #![feature(maybe_uninit_extra, maybe_uninit_slice)]

src/libcore/lib.rs

@@ -89,7 +89,7 @@
 #![feature(nll)]
 #![feature(exhaustive_patterns)]
 #![feature(no_core)]
-#![feature(on_unimplemented)]
+#![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(optin_builtin_traits)]
 #![feature(prelude_import)]
 #![feature(repr_simd, platform_intrinsics)]

src/librustc/error_codes.rs

@@ -607,7 +607,7 @@ position that needs that trait. For example, when the following code is
 compiled:
 
 ```compile_fail
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 fn foo<T: Index<u8>>(x: T){}
 
@@ -639,7 +639,7 @@ position that needs that trait. For example, when the following code is
 compiled:
 
 ```compile_fail
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 fn foo<T: Index<u8>>(x: T){}
 
@@ -669,7 +669,7 @@ position that needs that trait. For example, when the following code is
 compiled:
 
 ```compile_fail
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 fn foo<T: Index<u8>>(x: T){}
 

src/libstd/lib.rs

@@ -284,7 +284,7 @@
 #![feature(never_type)]
 #![feature(nll)]
 #![cfg_attr(bootstrap, feature(non_exhaustive))]
-#![feature(on_unimplemented)]
+#![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(optin_builtin_traits)]
 #![feature(panic_info_message)]
 #![feature(panic_internals)]

src/libsyntax/feature_gate/active.rs

@@ -134,9 +134,6 @@ declare_features! (
     /// Allows using `rustc_*` attributes (RFC 572).
     (active, rustc_attrs, "1.0.0", Some(29642), None),
 
-    /// Allows using `#[on_unimplemented(..)]` on traits.
-    (active, on_unimplemented, "1.0.0", Some(29628), None),
-
     /// Allows using the `box $expr` syntax.
     (active, box_syntax, "1.0.0", Some(49733), None),
 

src/libsyntax/feature_gate/builtin_attrs.rs

@@ -166,7 +166,7 @@ macro_rules! experimental {
 }
 
 const IMPL_DETAIL: &str = "internal implementation detail";
-const INTERAL_UNSTABLE: &str = "this is an internal attribute that will never be stable";
+const INTERNAL_UNSTABLE: &str = "this is an internal attribute that will never be stable";
 
 pub type BuiltinAttribute = (Symbol, AttributeType, AttributeTemplate, AttributeGate);
 
@@ -418,14 +418,14 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         linkage, Whitelisted, template!(NameValueStr: "external|internal|..."),
         "the `linkage` attribute is experimental and not portable across platforms",
     ),
-    rustc_attr!(rustc_std_internal_symbol, Whitelisted, template!(Word), INTERAL_UNSTABLE),
+    rustc_attr!(rustc_std_internal_symbol, Whitelisted, template!(Word), INTERNAL_UNSTABLE),
 
     // ==========================================================================
     // Internal attributes, Macro related:
     // ==========================================================================
 
     rustc_attr!(rustc_builtin_macro, Whitelisted, template!(Word), IMPL_DETAIL),
-    rustc_attr!(rustc_proc_macro_decls, Normal, template!(Word), INTERAL_UNSTABLE),
+    rustc_attr!(rustc_proc_macro_decls, Normal, template!(Word), INTERNAL_UNSTABLE),
     rustc_attr!(
         rustc_macro_transparency, Whitelisted,
         template!(NameValueStr: "transparent|semitransparent|opaque"),
@@ -436,25 +436,24 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // Internal attributes, Diagnostics related:
     // ==========================================================================
 
-    gated!(
+    rustc_attr!(
         rustc_on_unimplemented, Whitelisted,
         template!(
             List: r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#,
             NameValueStr: "message"
         ),
-        on_unimplemented,
-        experimental!(rustc_on_unimplemented),
+        INTERNAL_UNSTABLE
     ),
     // Whitelists "identity-like" conversion methods to suggest on type mismatch.
-    rustc_attr!(rustc_conversion_suggestion, Whitelisted, template!(Word), INTERAL_UNSTABLE),
+    rustc_attr!(rustc_conversion_suggestion, Whitelisted, template!(Word), INTERNAL_UNSTABLE),
 
     // ==========================================================================
     // Internal attributes, Const related:
     // ==========================================================================
 
     rustc_attr!(rustc_promotable, Whitelisted, template!(Word), IMPL_DETAIL),
     rustc_attr!(rustc_allow_const_fn_ptr, Whitelisted, template!(Word), IMPL_DETAIL),
-    rustc_attr!(rustc_args_required_const, Whitelisted, template!(List: "N"), INTERAL_UNSTABLE),
+    rustc_attr!(rustc_args_required_const, Whitelisted, template!(List: "N"), INTERNAL_UNSTABLE),
 
     // ==========================================================================
     // Internal attributes, Layout related:

src/libsyntax/feature_gate/removed.rs

@@ -99,6 +99,9 @@ declare_features! (
     /// + `__register_diagnostic`
     /// +`__build_diagnostic_array`
     (removed, rustc_diagnostic_macros, "1.38.0", None, None, None),
+    /// Allows using `#[on_unimplemented(..)]` on traits.
+    /// (Moved to `rustc_attrs`.)
+    (removed, on_unimplemented, "1.40.0", None, None, None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: removed features

src/test/incremental/issue-59523-on-implemented-is-not-unused.rs

@@ -5,7 +5,7 @@
 // revisions: cfail1 cfail2
 // build-pass (FIXME(62277): could be check-pass?)
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 #![deny(unused_attributes)]
 
 #[rustc_on_unimplemented = "invalid"]

src/test/ui/on-unimplemented/bad-annotation.rs

@@ -1,6 +1,6 @@
 // ignore-tidy-linelength
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 #![allow(unused)]
 

src/test/ui/on-unimplemented/expected-comma-found-token.rs

@@ -2,7 +2,7 @@
 // access to the variable, whether that mutable access be used
 // for direct assignment or for taking mutable ref. Issue #6801.
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 #[rustc_on_unimplemented(
     message="the message"

src/test/ui/on-unimplemented/feature-gate-on-unimplemented.rs

@@ -0,0 +1,8 @@
+// Test that `#[rustc_on_unimplemented]` is gated by `rustc_attrs` feature gate.
+
+#[rustc_on_unimplemented = "test error `{Self}` with `{Bar}`"]
+//~^ ERROR this is an internal attribute that will never be stable
+trait Foo<Bar>
+{}
+
+fn main() {}

src/test/ui/feature-gates/feature-gate-on-unimplemented.stderr → src/test/ui/on-unimplemented/feature-gate-on-unimplemented.stderr

@@ -1,11 +1,11 @@
-error[E0658]: the `#[rustc_on_unimplemented]` attribute is an experimental feature
-  --> $DIR/feature-gate-on-unimplemented.rs:4:1
+error[E0658]: this is an internal attribute that will never be stable
+  --> $DIR/feature-gate-on-unimplemented.rs:3:1
    |
 LL | #[rustc_on_unimplemented = "test error `{Self}` with `{Bar}`"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29628
-   = help: add `#![feature(on_unimplemented)]` to the crate attributes to enable
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
 
 error: aborting due to previous error
 

src/test/ui/on-unimplemented/multiple-impls.rs

@@ -1,6 +1,6 @@
 // Test if the on_unimplemented message override works
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 
 struct Foo<T>(T);

src/test/ui/on-unimplemented/on-impl.rs

@@ -1,6 +1,6 @@
 // Test if the on_unimplemented message override works
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 
 #[rustc_on_unimplemented = "invalid"]

src/test/ui/on-unimplemented/on-trait.rs

@@ -1,6 +1,6 @@
 // ignore-tidy-linelength
 
-#![feature(on_unimplemented)]
+#![feature(rustc_attrs)]
 
 pub mod Bar {
   #[rustc_on_unimplemented = "test error `{Self}` with `{Bar}` `{Baz}` `{Quux}` in `{Foo}`"]