Replace old private-in-public diagnostic with type privacy lints

Author: Bryanskiy

compiler/rustc_error_codes/src/error_codes.rs

@@ -607,6 +607,7 @@ E0794: include_str!("./error_codes/E0794.md"),
 //  E0420, // merged into 532
 //  E0421, // merged into 531
 //  E0427, // merged into 530
+//  E0445, // merged into 446 and type privacy lints
 //  E0456, // plugin `..` is not available for triple `..`
 //  E0465, // removed: merged with E0464
 //  E0467, // removed

compiler/rustc_error_codes/src/error_codes/E0445.md

@@ -1,10 +1,10 @@
-A private trait was used on a public type parameter bound.
+#### Note: this error code is no longer emitted by the compiler.
 
-Erroneous code examples:
+A private trait was used on a public type parameter bound.
 
-```compile_fail,E0445
-#![deny(private_in_public)]
+Previously erroneous code examples:
 
+```
 trait Foo {
     fn dummy(&self) { }
 }

compiler/rustc_error_codes/src/error_codes/E0446.md

@@ -1,16 +1,16 @@
-A private type was used in a public type signature.
+A private type or trait was used in a public associated type signature.
 
 Erroneous code example:
 
 ```compile_fail,E0446
-#![deny(private_in_public)]
-struct Bar(u32);
-
-mod foo {
-    use crate::Bar;
-    pub fn bar() -> Bar { // error: private type in public interface
-        Bar(0)
-    }
+struct Bar;
+
+pub trait PubTr {
+    type Alias;
+}
+
+impl PubTr for u8 {
+    type Alias = Bar; // error private type in public interface
 }
 
 fn main() {}
@@ -22,13 +22,14 @@ This is done by using pub(crate) or pub(in crate::my_mod::etc)
 Example:
 
 ```
-struct Bar(u32);
+struct Bar;
+
+pub(crate) trait PubTr { // only public to crate root
+    type Alias;
+}
 
-mod foo {
-    use crate::Bar;
-    pub(crate) fn bar() -> Bar { // only public to crate root
-        Bar(0)
-    }
+impl PubTr for u8 {
+    type Alias = Bar;
 }
 
 fn main() {}
@@ -38,12 +39,15 @@ The other way to solve this error is to make the private type public.
 Example:
 
 ```
-pub struct Bar(u32); // we set the Bar type public
-mod foo {
-    use crate::Bar;
-    pub fn bar() -> Bar { // ok!
-        Bar(0)
-    }
+
+pub struct Bar; // we set the Bar trait public
+
+pub trait PubTr {
+    type Alias;
+}
+
+impl PubTr for u8 {
+    type Alias = Bar;
 }
 
 fn main() {}

compiler/rustc_lint/src/lib.rs

@@ -516,6 +516,11 @@ fn register_builtins(store: &mut LintStore) {
         "converted into hard error, see issue #82523 \
          <https://github.com/rust-lang/rust/issues/82523> for more information",
     );
+    store.register_removed(
+        "private_in_public",
+        "replaced with another group of lints, see RFC \
+         <https://rust-lang.github.io/rfcs/2145-type-privacy.html> for more information",
+    );
 }
 
 fn register_internals(store: &mut LintStore) {

compiler/rustc_lint_defs/src/builtin.rs

@@ -982,44 +982,6 @@ declare_lint! {
     "detects trivial casts of numeric types which could be removed"
 }
 
-declare_lint! {
-    /// The `private_in_public` lint detects private items in public
-    /// interfaces not caught by the old implementation.
-    ///
-    /// ### Example
-    ///
-    /// ```rust
-    /// # #![allow(unused)]
-    /// struct SemiPriv;
-    ///
-    /// mod m1 {
-    ///     struct Priv;
-    ///     impl super::SemiPriv {
-    ///         pub fn f(_: Priv) {}
-    ///     }
-    /// }
-    /// # fn main() {}
-    /// ```
-    ///
-    /// {{produces}}
-    ///
-    /// ### Explanation
-    ///
-    /// The visibility rules are intended to prevent exposing private items in
-    /// public interfaces. This is a [future-incompatible] lint to transition
-    /// this to a hard error in the future. See [issue #34537] for more
-    /// details.
-    ///
-    /// [issue #34537]: https://github.com/rust-lang/rust/issues/34537
-    /// [future-incompatible]: ../index.md#future-incompatible-lints
-    pub PRIVATE_IN_PUBLIC,
-    Warn,
-    "detect private items in public interfaces not caught by the old implementation",
-    @future_incompatible = FutureIncompatibleInfo {
-        reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
-    };
-}
-
 declare_lint! {
     /// The `invalid_alignment` lint detects dereferences of misaligned pointers during
     /// constant evaluation.
@@ -3374,7 +3336,6 @@ declare_lint_pass! {
         PATTERNS_IN_FNS_WITHOUT_BODY,
         POINTER_STRUCTURAL_MATCH,
         PRIVATE_BOUNDS,
-        PRIVATE_IN_PUBLIC,
         PRIVATE_INTERFACES,
         PROC_MACRO_BACK_COMPAT,
         PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
@@ -4293,9 +4254,7 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// # #![feature(type_privacy_lints)]
     /// # #![allow(unused)]
-    /// # #![allow(private_in_public)]
     /// #![deny(private_interfaces)]
     /// struct SemiPriv;
     ///
@@ -4316,9 +4275,8 @@ declare_lint! {
     /// Having something private in primary interface guarantees that
     /// the item will be unusable from outer modules due to type privacy.
     pub PRIVATE_INTERFACES,
-    Allow,
+    Warn,
     "private type in primary interface of an item",
-    @feature_gate = sym::type_privacy_lints;
 }
 
 declare_lint! {
@@ -4329,8 +4287,6 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// # #![feature(type_privacy_lints)]
-    /// # #![allow(private_in_public)]
     /// # #![allow(unused)]
     /// #![deny(private_bounds)]
     ///
@@ -4348,9 +4304,8 @@ declare_lint! {
     /// Having private types or traits in item bounds makes it less clear what interface
     /// the item actually provides.
     pub PRIVATE_BOUNDS,
-    Allow,
+    Warn,
     "private type in secondary interface of an item",
-    @feature_gate = sym::type_privacy_lints;
 }
 
 declare_lint! {

compiler/rustc_middle/src/hir/map/mod.rs

@@ -1222,7 +1222,6 @@ pub(super) fn crate_hash(tcx: TyCtxt<'_>, _: LocalCrate) -> Svh {
         tcx.sess.local_stable_crate_id().hash_stable(&mut hcx, &mut stable_hasher);
         // Hash visibility information since it does not appear in HIR.
         resolutions.visibilities.hash_stable(&mut hcx, &mut stable_hasher);
-        resolutions.has_pub_restricted.hash_stable(&mut hcx, &mut stable_hasher);
         stable_hasher.finish()
     });
 

compiler/rustc_middle/src/ty/mod.rs

@@ -162,8 +162,6 @@ pub struct ResolverOutputs {
 #[derive(Debug)]
 pub struct ResolverGlobalCtxt {
     pub visibilities: FxHashMap<LocalDefId, Visibility>,
-    /// This field is used to decide whether we should make `PRIVATE_IN_PUBLIC` a hard error.
-    pub has_pub_restricted: bool,
     /// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`.
     pub expn_that_defined: FxHashMap<LocalDefId, ExpnId>,
     pub effective_visibilities: EffectiveVisibilities,

compiler/rustc_privacy/messages.ftl

@@ -11,11 +11,6 @@ privacy_in_public_interface = {$vis_descr} {$kind} `{$descr}` in public interfac
 
 privacy_item_is_private = {$kind} `{$descr}` is private
     .label = private {$kind}
-privacy_private_in_public_lint =
-    {$vis_descr} {$kind} `{$descr}` in public interface (error {$kind ->
-        [trait] E0445
-        *[other] E0446
-    })
 
 privacy_private_interface_or_bounds_lint = {$ty_kind} `{$ty_descr}` is more private than the item `{$item_descr}`
     .item_label = {$item_kind} `{$item_descr}` is reachable at visibility `{$item_vis_descr}`

compiler/rustc_privacy/src/errors.rs

@@ -47,21 +47,6 @@ pub struct UnnamedItemIsPrivate {
     pub kind: &'static str,
 }
 
-// Duplicate of `InPublicInterface` but with a different error code, shares the same slug.
-#[derive(Diagnostic)]
-#[diag(privacy_in_public_interface, code = "E0445")]
-pub struct InPublicInterfaceTraits<'a> {
-    #[primary_span]
-    #[label]
-    pub span: Span,
-    pub vis_descr: &'static str,
-    pub kind: &'a str,
-    pub descr: DiagnosticArgFromDisplay<'a>,
-    #[label(privacy_visibility_label)]
-    pub vis_span: Span,
-}
-
-// Duplicate of `InPublicInterfaceTraits` but with a different error code, shares the same slug.
 #[derive(Diagnostic)]
 #[diag(privacy_in_public_interface, code = "E0446")]
 pub struct InPublicInterface<'a> {
@@ -91,14 +76,6 @@ pub struct FromPrivateDependencyInPublicInterface<'a> {
     pub krate: Symbol,
 }
 
-#[derive(LintDiagnostic)]
-#[diag(privacy_private_in_public_lint)]
-pub struct PrivateInPublicLint<'a> {
-    pub vis_descr: &'static str,
-    pub kind: &'a str,
-    pub descr: DiagnosticArgFromDisplay<'a>,
-}
-
 #[derive(LintDiagnostic)]
 #[diag(privacy_unnameable_types_lint)]
 pub struct UnnameableTypesLint<'a> {