privacy: Feature gate new type privacy lints

compiler/rustc_feature/src/active.rs

@@ -539,6 +539,8 @@ pub fn set(&self, features: &mut Features, span: Span) {
     /// Allows creation of instances of a struct by moving fields that have
     /// not changed from prior instances of the same struct (RFC #2528)
     (active, type_changing_struct_update, "1.58.0", Some(86555), None),
+    /// Allows using type privacy lints (`private_interfaces`, `private_bounds`, `unnameable_types`).
+    (active, type_privacy_lints, "CURRENT_RUSTC_VERSION", Some(48054), None),
     /// Enables rustc to generate code that instructs libstd to NOT ignore SIGPIPE.
     (active, unix_sigpipe, "1.65.0", Some(97889), None),
     /// Allows unsized fn parameters.

compiler/rustc_lint_defs/src/builtin.rs

@@ -4263,6 +4263,7 @@
     /// ### Example
     ///
     /// ```rust,compile_fail
+    /// # #![feature(type_privacy_lints)]
     /// # #![allow(unused)]
     /// # #![allow(private_in_public)]
     /// #![deny(private_interfaces)]
@@ -4287,6 +4288,7 @@
     pub PRIVATE_INTERFACES,
     Allow,
     "private type in primary interface of an item",
+    @feature_gate = sym::type_privacy_lints;
 }
 
 declare_lint! {
@@ -4297,6 +4299,7 @@
     /// ### Example
     ///
     /// ```rust,compile_fail
+    /// # #![feature(type_privacy_lints)]
     /// # #![allow(private_in_public)]
     /// # #![allow(unused)]
     /// #![deny(private_bounds)]
@@ -4316,7 +4319,8 @@
     /// the item actually provides.
     pub PRIVATE_BOUNDS,
     Allow,
-    "private type in secondary interface of an item"
+    "private type in secondary interface of an item",
+    @feature_gate = sym::type_privacy_lints;
 }
 
 declare_lint! {
@@ -4326,6 +4330,7 @@
     /// ### Example
     ///
     /// ```rust,compile_fail
+    /// # #![feature(type_privacy_lints)]
     /// # #![allow(unused)]
     /// #![deny(unnameable_types)]
     /// mod m {
@@ -4344,5 +4349,6 @@
     /// you can name the type `T` as well, this lint attempts to enforce this rule.
     pub UNNAMEABLE_TYPES,
     Allow,
-    "effective visibility of a type is larger than the area in which it can be named"
+    "effective visibility of a type is larger than the area in which it can be named",
+    @feature_gate = sym::type_privacy_lints;
 }

compiler/rustc_span/src/symbol.rs

@@ -1555,6 +1555,7 @@
         type_length_limit,
         type_macros,
         type_name,
+        type_privacy_lints,
         u128,
         u16,
         u32,

tests/ui/associated-inherent-types/private-in-public.rs

@@ -1,7 +1,7 @@
 #![feature(inherent_associated_types)]
+#![feature(type_privacy_lints)]
 #![allow(incomplete_features)]
 #![crate_type = "lib"]
-
 #![deny(private_in_public)]
 #![warn(private_interfaces)]
 

tests/ui/const-generics/generic_const_exprs/eval-privacy.rs

@@ -1,7 +1,7 @@
 #![crate_type = "lib"]
 #![feature(generic_const_exprs)]
+#![feature(type_privacy_lints)]
 #![allow(incomplete_features)]
-
 #![warn(private_interfaces)]
 
 // In this test both old and new private-in-public diagnostic were emitted.

tests/ui/error-codes/E0445.rs

@@ -1,3 +1,4 @@
+#![feature(type_privacy_lints)]
 #[warn(private_bounds)]
 #[warn(private_interfaces)]
 

tests/ui/error-codes/E0445.stderr

@@ -1,5 +1,5 @@
 error[E0445]: private trait `Foo` in public interface
-  --> $DIR/E0445.rs:12:1
+  --> $DIR/E0445.rs:13:1
    |
 LL | trait Foo {
    | --------- `Foo` declared as private
@@ -10,23 +10,23 @@ LL | pub trait Bar : Foo {}
 warning: trait `Foo` is more private than the item `Bar`
    |
 note: trait `Bar` is reachable at visibility `pub`
-  --> $DIR/E0445.rs:12:1
+  --> $DIR/E0445.rs:13:1
    |
 LL | pub trait Bar : Foo {}
    | ^^^^^^^^^^^^^^^^^^^
 note: but trait `Foo` is only usable at visibility `pub(crate)`
-  --> $DIR/E0445.rs:8:1
+  --> $DIR/E0445.rs:9:1
    |
 LL | trait Foo {
    | ^^^^^^^^^
 note: the lint level is defined here
-  --> $DIR/E0445.rs:1:8
+  --> $DIR/E0445.rs:2:8
    |
 LL | #[warn(private_bounds)]
    |        ^^^^^^^^^^^^^^
 
 error[E0445]: private trait `Foo` in public interface
-  --> $DIR/E0445.rs:14:1
+  --> $DIR/E0445.rs:15:1
    |
 LL | trait Foo {
    | --------- `Foo` declared as private
@@ -37,18 +37,18 @@ LL | pub struct Bar2<T: Foo>(pub T);
 warning: trait `Foo` is more private than the item `Bar2`
    |
 note: struct `Bar2` is reachable at visibility `pub`
-  --> $DIR/E0445.rs:14:1
+  --> $DIR/E0445.rs:15:1
    |
 LL | pub struct Bar2<T: Foo>(pub T);
    | ^^^^^^^^^^^^^^^^^^^^^^^
 note: but trait `Foo` is only usable at visibility `pub(crate)`
-  --> $DIR/E0445.rs:8:1
+  --> $DIR/E0445.rs:9:1
    |
 LL | trait Foo {
    | ^^^^^^^^^
 
 error[E0445]: private trait `Foo` in public interface
-  --> $DIR/E0445.rs:16:1
+  --> $DIR/E0445.rs:17:1
    |
 LL | trait Foo {
    | --------- `Foo` declared as private
@@ -59,12 +59,12 @@ LL | pub fn foo<T: Foo> (t: T) {}
 warning: trait `Foo` is more private than the item `foo`
    |
 note: function `foo` is reachable at visibility `pub`
-  --> $DIR/E0445.rs:16:1
+  --> $DIR/E0445.rs:17:1
    |
 LL | pub fn foo<T: Foo> (t: T) {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: but trait `Foo` is only usable at visibility `pub(crate)`
-  --> $DIR/E0445.rs:8:1
+  --> $DIR/E0445.rs:9:1
    |
 LL | trait Foo {
    | ^^^^^^^^^

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

@@ -0,0 +1,12 @@
+// check-pass
+
+#![warn(private_interfaces)] //~ WARN unknown lint
+                             //~| WARN unknown lint
+                             //~| WARN unknown lint
+#![warn(private_bounds)] //~ WARN unknown lint
+                         //~| WARN unknown lint
+                         //~| WARN unknown lint
+#![warn(unnameable_types)] //~ WARN unknown lint
+                           //~| WARN unknown lint
+                           //~| WARN unknown lint
+fn main() {}

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

@@ -0,0 +1,93 @@
+warning: unknown lint: `private_interfaces`
+  --> $DIR/feature-gate-type_privacy_lints.rs:3:1
+   |
+LL | #![warn(private_interfaces)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_interfaces` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+   = note: `#[warn(unknown_lints)]` on by default
+
+warning: unknown lint: `private_bounds`
+  --> $DIR/feature-gate-type_privacy_lints.rs:6:1
+   |
+LL | #![warn(private_bounds)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_bounds` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `unnameable_types`
+  --> $DIR/feature-gate-type_privacy_lints.rs:9:1
+   |
+LL | #![warn(unnameable_types)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `unnameable_types` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `private_interfaces`
+  --> $DIR/feature-gate-type_privacy_lints.rs:3:1
+   |
+LL | #![warn(private_interfaces)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_interfaces` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `private_bounds`
+  --> $DIR/feature-gate-type_privacy_lints.rs:6:1
+   |
+LL | #![warn(private_bounds)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_bounds` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `unnameable_types`
+  --> $DIR/feature-gate-type_privacy_lints.rs:9:1
+   |
+LL | #![warn(unnameable_types)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `unnameable_types` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `private_interfaces`
+  --> $DIR/feature-gate-type_privacy_lints.rs:3:1
+   |
+LL | #![warn(private_interfaces)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_interfaces` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `private_bounds`
+  --> $DIR/feature-gate-type_privacy_lints.rs:6:1
+   |
+LL | #![warn(private_bounds)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `private_bounds` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: unknown lint: `unnameable_types`
+  --> $DIR/feature-gate-type_privacy_lints.rs:9:1
+   |
+LL | #![warn(unnameable_types)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `unnameable_types` lint is unstable
+   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
+   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
+
+warning: 9 warnings emitted
+

tests/ui/issues/issue-18389.rs

@@ -1,3 +1,4 @@
+#![feature(type_privacy_lints)]
 #![warn(private_bounds)]
 
 // In this test both old and new private-in-public diagnostic were emitted.

tests/ui/issues/issue-18389.stderr

@@ -1,5 +1,5 @@
 error[E0445]: private trait `Private<<Self as Public>::P, <Self as Public>::R>` in public interface
-  --> $DIR/issue-18389.rs:13:1
+  --> $DIR/issue-18389.rs:14:1
    |
 LL |   trait Private<P, R> {
    |   ------------------- `Private<<Self as Public>::P, <Self as Public>::R>` declared as private
@@ -14,7 +14,7 @@ LL | | > {
 warning: trait `Private<<Self as Public>::P, <Self as Public>::R>` is more private than the item `Public`
    |
 note: trait `Public` is reachable at visibility `pub`
-  --> $DIR/issue-18389.rs:13:1
+  --> $DIR/issue-18389.rs:14:1
    |
 LL | / pub trait Public: Private<
 LL | |
@@ -23,12 +23,12 @@ LL | |     <Self as Public>::R
 LL | | > {
    | |_^
 note: but trait `Private<<Self as Public>::P, <Self as Public>::R>` is only usable at visibility `pub(crate)`
-  --> $DIR/issue-18389.rs:10:1
+  --> $DIR/issue-18389.rs:11:1
    |
 LL | trait Private<P, R> {
    | ^^^^^^^^^^^^^^^^^^^
 note: the lint level is defined here
-  --> $DIR/issue-18389.rs:1:9
+  --> $DIR/issue-18389.rs:2:9
    |
 LL | #![warn(private_bounds)]
    |         ^^^^^^^^^^^^^^

tests/ui/privacy/private-in-public-non-principal.rs

@@ -1,6 +1,6 @@
 #![feature(auto_traits)]
 #![feature(negative_impls)]
-
+#![feature(type_privacy_lints)]
 #![deny(private_interfaces)]
 
 // In this test both old and new private-in-public diagnostic were emitted.

tests/ui/privacy/unnameable_types.rs

@@ -1,4 +1,4 @@
-#![allow(unused)]
+#![feature(type_privacy_lints)]
 #![allow(private_in_public)]
 #![deny(unnameable_types)]
 

tests/ui/privacy/where-priv-type.rs

@@ -3,8 +3,8 @@
 
 #![crate_type = "lib"]
 #![feature(generic_const_exprs)]
+#![feature(type_privacy_lints)]
 #![allow(incomplete_features)]
-
 #![warn(private_bounds)]
 #![warn(private_interfaces)]
 

tests/ui/privacy/where-pub-type-impls-priv-trait.rs

@@ -2,8 +2,8 @@
 
 #![crate_type = "lib"]
 #![feature(generic_const_exprs)]
+#![feature(type_privacy_lints)]
 #![allow(incomplete_features)]
-
 #![warn(private_bounds)]
 
 // In this test both old and new private-in-public diagnostic were emitted.

tests/ui/pub/issue-33174-restricted-type-in-public-interface.rs

@@ -1,3 +1,4 @@
+#![feature(type_privacy_lints)]
 #![allow(non_camel_case_types)] // genus is always capitalized
 #![warn(private_interfaces)]
 //~^ NOTE the lint level is defined here

tests/ui/pub/issue-33174-restricted-type-in-public-interface.stderr

@@ -1,5 +1,5 @@
 error[E0446]: private type `Snail` in public interface
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:27:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:28:1
    |
 LL | pub(crate) struct Snail;
    | ----------------------- `Snail` declared as private
@@ -10,23 +10,23 @@ LL | pub type Helix_pomatia = Shell<Snail>;
 warning: type `Snail` is more private than the item `Helix_pomatia`
    |
 note: type alias `Helix_pomatia` is reachable at visibility `pub`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:27:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:28:1
    |
 LL | pub type Helix_pomatia = Shell<Snail>;
    | ^^^^^^^^^^^^^^^^^^^^^^
 note: but type `Snail` is only usable at visibility `pub(crate)`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:9:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:10:1
    |
 LL | pub(crate) struct Snail;
    | ^^^^^^^^^^^^^^^^^^^^^^^
 note: the lint level is defined here
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:2:9
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:3:9
    |
 LL | #![warn(private_interfaces)]
    |         ^^^^^^^^^^^^^^^^^^
 
 error[E0446]: crate-private type `Turtle` in public interface
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:31:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:32:1
    |
 LL |     pub(super) struct Turtle;
    |     ------------------------ `Turtle` declared as crate-private
@@ -37,18 +37,18 @@ LL | pub type Dermochelys_coriacea = Shell<sea::Turtle>;
 warning: type `Turtle` is more private than the item `Dermochelys_coriacea`
    |
 note: type alias `Dermochelys_coriacea` is reachable at visibility `pub`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:31:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:32:1
    |
 LL | pub type Dermochelys_coriacea = Shell<sea::Turtle>;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: but type `Turtle` is only usable at visibility `pub(crate)`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:14:5
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:15:5
    |
 LL |     pub(super) struct Turtle;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0446]: private type `Tortoise` in public interface
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:35:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:36:1
    |
 LL | struct Tortoise;
    | --------------- `Tortoise` declared as private
@@ -59,12 +59,12 @@ LL | pub type Testudo_graeca = Shell<Tortoise>;
 warning: type `Tortoise` is more private than the item `Testudo_graeca`
    |
 note: type alias `Testudo_graeca` is reachable at visibility `pub`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:35:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:36:1
    |
 LL | pub type Testudo_graeca = Shell<Tortoise>;
    | ^^^^^^^^^^^^^^^^^^^^^^^
 note: but type `Tortoise` is only usable at visibility `pub(crate)`
-  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:19:1
+  --> $DIR/issue-33174-restricted-type-in-public-interface.rs:20:1
    |
 LL | struct Tortoise;
    | ^^^^^^^^^^^^^^^