Rollup merge of #152210 - Ozzy1423:attrs7, r=JonathanBrouwer

Gate #![reexport_test_harness_main] properly

Address the FIXME

Removed from `issue-43106-gating-of-builtin-attrs.rs` since that is for stable attributes only.

This would be a breaking change, search of github shows it is mostly but not always used with `#![test_runner]` which is already gated correctly.

Details:
#50297

Feel free to close this issue if you think it is not worth addressing the FIXME...

Author: JonathanBrouwer

compiler/rustc_feature/src/builtin_attrs.rs

@@ -473,11 +473,6 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         ),
         FutureWarnFollowing, EncodeCrossCrate::No,
     ),
-    // FIXME(Centril): This can be used on stable but shouldn't.
-    ungated!(
-        reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"), ErrorFollowing,
-        EncodeCrossCrate::No,
-    ),
 
     // Macros:
     ungated!(
@@ -831,6 +826,13 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         EncodeCrossCrate::Yes, custom_test_frameworks,
         "custom test frameworks are an unstable feature",
     ),
+
+    gated!(
+        reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"), ErrorFollowing,
+        EncodeCrossCrate::No, custom_test_frameworks,
+        "custom test frameworks are an unstable feature",
+    ),
+
     // RFC #1268
     gated!(
         marker, Normal, template!(Word), WarnFollowing, EncodeCrossCrate::No,

src/tools/rust-analyzer/crates/hir-expand/src/inert_attr_macro.rs

@@ -124,8 +124,6 @@ pub const INERT_ATTRIBUTES: &[BuiltinAttribute] = &[
         should_panic, Normal,
         template!(Word, List: r#"expected = "reason""#, NameValueStr: "reason"), FutureWarnFollowing,
     ),
-    // FIXME(Centril): This can be used on stable but shouldn't.
-    ungated!(reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"), ErrorFollowing),
 
     // Macros:
     ungated!(automatically_derived, Normal, template!(Word), WarnFollowing),
@@ -264,6 +262,13 @@ pub const INERT_ATTRIBUTES: &[BuiltinAttribute] = &[
         test_runner, CrateLevel, template!(List: "path"), ErrorFollowing, custom_test_frameworks,
         "custom test frameworks are an unstable feature",
     ),
+
+    gated!(
+        reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"),
+        ErrorFollowing, custom_test_frameworks,
+        "custom test frameworks are an unstable feature",
+    ),
+
     // RFC #1268
     gated!(
         marker, Normal, template!(Word), WarnFollowing, @only_local: true,

tests/ui/attributes/reexport-test-harness-entry-point.rs

@@ -4,6 +4,7 @@
 //@ run-pass
 //@ compile-flags:--test
 
+#![feature(custom_test_frameworks)]
 #![reexport_test_harness_main = "test_main"]
 
 #[cfg(test)]

tests/ui/feature-gates/feature-gate-custom_test_frameworks.rs

@@ -1,5 +1,5 @@
 #![test_runner(main)] //~ ERROR custom test frameworks are an unstable feature
-
+#![reexport_test_harness_main = "foo"] //~ ERROR custom test frameworks are an unstable feature
 #[test_case] //~ ERROR custom test frameworks are an unstable feature
 fn f() {}
 

tests/ui/feature-gates/feature-gate-custom_test_frameworks.stderr

@@ -18,6 +18,16 @@ LL | #![test_runner(main)]
    = help: add `#![feature(custom_test_frameworks)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error: aborting due to 2 previous errors
+error[E0658]: custom test frameworks are an unstable feature
+  --> $DIR/feature-gate-custom_test_frameworks.rs:2:1
+   |
+LL | #![reexport_test_harness_main = "foo"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
+   = help: add `#![feature(custom_test_frameworks)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0658`.

tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs

@@ -55,7 +55,6 @@
 //~| HELP can only be applied to
 //~| HELP remove the attribute
 #![no_implicit_prelude]
-#![reexport_test_harness_main = "2900"]
 // see gated-link-args.rs
 // see issue-43106-gating-of-macro_escape.rs for crate-level; but non crate-level is below at "2700"
 // (cannot easily test gating of crate-level #[no_std]; but non crate-level is below at "2600")
@@ -465,30 +464,6 @@ mod no_implicit_prelude {
     //~| HELP remove the attribute
 }
 
-#[reexport_test_harness_main = "2900"]
-//~^ WARN crate-level attribute should be
-mod reexport_test_harness_main {
-//~^ NOTE this attribute does not have an `!`, which means it is applied to this module
-    mod inner { #![reexport_test_harness_main="2900"] }
-    //~^ WARN the `#![reexport_test_harness_main]` attribute can only be used at the crate root
-
-    #[reexport_test_harness_main = "2900"] fn f() { }
-    //~^ WARN crate-level attribute should be
-    //~| NOTE this attribute does not have an `!`, which means it is applied to this function
-
-    #[reexport_test_harness_main = "2900"] struct S;
-    //~^ WARN crate-level attribute should be
-    //~| NOTE this attribute does not have an `!`, which means it is applied to this struct
-
-    #[reexport_test_harness_main = "2900"] type T = S;
-    //~^ WARN crate-level attribute should be
-    //~| NOTE this attribute does not have an `!`, which means it is applied to this type alias
-
-    #[reexport_test_harness_main = "2900"] impl S { }
-    //~^ WARN crate-level attribute should be
-    //~| NOTE this attribute does not have an `!`, which means it is applied to this implementation block
-}
-
 // Cannot feed "2700" to `#[macro_escape]` without signaling an error.
 #[macro_escape]
 //~^ WARN `#[macro_escape]` is a deprecated synonym for `#[macro_use]`