Auto merge of #111801 - Bryanskiy:lints1, r=petrochenkov

Private-in-public lints implementation

Next part of RFC https://github.com/rust-lang/rust/issues/48054.

r? `@petrochenkov`

1 files changed, 95 insertions, 0 deletions

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index eb246c3f93e..53ece08ac3d 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -3372,7 +3372,9 @@ declare_lint_pass! {
         OVERLAPPING_RANGE_ENDPOINTS,
         PATTERNS_IN_FNS_WITHOUT_BODY,
         POINTER_STRUCTURAL_MATCH,
+        PRIVATE_BOUNDS,
         PRIVATE_IN_PUBLIC,
+        PRIVATE_INTERFACES,
         PROC_MACRO_BACK_COMPAT,
         PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
         PUB_USE_OF_PRIVATE_EXTERN_CRATE,
@@ -3399,6 +3401,7 @@ declare_lint_pass! {
         UNINHABITED_STATIC,
         UNKNOWN_CRATE_TYPES,
         UNKNOWN_LINTS,
+        UNNAMEABLE_TYPES,
         UNREACHABLE_CODE,
         UNREACHABLE_PATTERNS,
         UNSAFE_OP_IN_UNSAFE_FN,
@@ -4251,3 +4254,95 @@ declare_lint! {
     Warn,
     "\"invalid_parameter\" isn't a valid argument for `#[macro_export]`",
 }
+
+declare_lint! {
+    /// The `private_interfaces` lint detects types in a primary interface of an item,
+    /// that are more private than the item itself. Primary interface of an item is all
+    /// its interface except for bounds on generic parameters and where clauses.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #![allow(unused)]
+    /// # #![allow(private_in_public)]
+    /// #![deny(private_interfaces)]
+    /// struct SemiPriv;
+    ///
+    /// mod m1 {
+    ///     struct Priv;
+    ///     impl crate::SemiPriv {
+    ///         pub fn f(_: Priv) {}
+    ///     }
+    /// }
+    ///
+    /// # fn main() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Having something private in primary interface guarantees that
+    /// the item will be unusable from outer modules due to type privacy.
+    pub PRIVATE_INTERFACES,
+    Allow,
+    "private type in primary interface of an item",
+}
+
+declare_lint! {
+    /// The `private_bounds` lint detects types in a secondary interface of an item,
+    /// that are more private than the item itself. Secondary interface of an item consists of
+    /// bounds on generic parameters and where clauses, including supertraits for trait items.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #![allow(private_in_public)]
+    /// # #![allow(unused)]
+    /// #![deny(private_bounds)]
+    ///
+    /// struct PrivTy;
+    /// pub struct S
+    ///     where PrivTy:
+    /// {}
+    /// # fn main() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Having private types or traits in item bounds makes it less clear what interface
+    /// the item actually provides.
+    pub PRIVATE_BOUNDS,
+    Allow,
+    "private type in secondary interface of an item"
+}
+
+declare_lint! {
+    /// The `unnameable_types` lint detects types for which you can get objects of that type,
+    /// but cannot name the type itself.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #![allow(unused)]
+    /// #![deny(unnameable_types)]
+    /// mod m {
+    ///     pub struct S;
+    /// }
+    ///
+    /// pub fn get_voldemort() -> m::S { m::S }
+    /// # fn main() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// It is often expected that if you can obtain an object of type `T`, then
+    /// 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"
+}