fix: Implement missing logics in exported_private_dependencies lint

compiler/rustc_privacy/src/lib.rs

@@ -1351,6 +1351,7 @@ struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
     required_effective_vis: Option<EffectiveVisibility>,
     in_assoc_ty: bool,
     in_primary_interface: bool,
+    check_private_dep_leaks_only: bool,
 }
 
 impl SearchInterfaceForPrivateItemsVisitor<'_> {
@@ -1411,6 +1412,10 @@ impl SearchInterfaceForPrivateItemsVisitor<'_> {
             );
         }
 
+        if self.check_private_dep_leaks_only {
+            return false;
+        }
+
         let Some(local_def_id) = def_id.as_local() else {
             return false;
         };
@@ -1530,6 +1535,23 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
             required_effective_vis,
             in_assoc_ty: false,
             in_primary_interface: true,
+            check_private_dep_leaks_only: false,
+        }
+    }
+
+    fn check_private_dep_leaks_only(
+        &self,
+        def_id: LocalDefId,
+        required_visibility: ty::Visibility,
+    ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
+        SearchInterfaceForPrivateItemsVisitor {
+            tcx: self.tcx,
+            item_def_id: def_id,
+            required_visibility,
+            required_effective_vis: None,
+            in_assoc_ty: false,
+            in_primary_interface: true,
+            check_private_dep_leaks_only: true,
         }
     }
 
@@ -1732,6 +1754,14 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
                             .generics()
                             .predicates();
                     }
+
+                    // normally, a public item can implement a private trait, but this should be linted for leakages of
+                    // private dependencies.
+                    if let Some(trait_ref) = tcx.impl_trait_ref(item.owner_id.def_id) {
+                        self.check_private_dep_leaks_only(item.owner_id.def_id, impl_vis)
+                            .visit_trait(trait_ref.instantiate_identity());
+                    }
+
                     for impl_item_ref in impl_.items {
                         let impl_item_vis = if impl_.of_trait.is_none() {
                             min(
@@ -1759,6 +1789,33 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
                     }
                 }
             }
+            DefKind::Use => {
+                let item = tcx.hir_item(id);
+                if let hir::ItemKind::Use(path, use_kind) = item.kind
+                    // List imports are desugared as single ones so skip `ListStem`s
+                    && use_kind != rustc_hir::UseKind::ListStem
+                {
+                    if let Some(def_id) = path.res.iter().filter_map(Res::opt_def_id).last() {
+                        // normally, public items in a private modules can be re-exported but this should be linted for
+                        // leakages of a private dependencies
+                        self.check_private_dep_leaks_only(item.owner_id.def_id, item_visibility)
+                            .check_def_id(
+                                def_id,
+                                item.kind.descr(),
+                                &LazyDefPathStr { def_id, tcx },
+                            );
+                    }
+                }
+            }
+            DefKind::ExternCrate => {
+                let item = tcx.hir_item(id);
+                if let Some(cnum) = tcx.extern_mod_stmt_cnum(item.owner_id.def_id) {
+                    let def_id = cnum.as_def_id();
+                    // `pub extern some_dep` should be linted if and only if `some_dep` is a private dependency
+                    self.check_private_dep_leaks_only(item.owner_id.def_id, item_visibility)
+                        .visit_def_id(def_id, item.kind.descr(), &LazyDefPathStr { def_id, tcx });
+                }
+            }
             _ => {}
         }
     }

library/std/Cargo.toml

@@ -25,7 +25,7 @@ hashbrown = { version = "0.15", default-features = false, features = [
 ] }
 std_detect = { path = "../stdarch/crates/std_detect", default-features = false, features = [
     'rustc-dep-of-std',
-] }
+], public = true }
 
 # Dependencies of the `backtrace` crate
 rustc-demangle = { version = "0.1.24", features = ['rustc-dep-of-std'] }

tests/ui/privacy/pub-priv-dep/pub-priv1.rs

@@ -7,10 +7,11 @@
 // dependency or a private one.
 
 #![deny(exported_private_dependencies)]
+#![allow(hidden_glob_reexports)]
 
 // This crate is a private dependency
-// FIXME: This should trigger.
 pub extern crate priv_dep;
+//~^ ERROR extern crate `priv_dep` from private dependency 'priv_dep' in public interface
 // This crate is a public dependency
 extern crate pub_dep;
 // This crate is a private dependency
@@ -77,31 +78,30 @@ pub type Alias = OtherType;
 
 pub struct PublicWithPrivateImpl;
 
-// FIXME: This should trigger.
-// See https://github.com/rust-lang/rust/issues/71043
 impl OtherTrait for PublicWithPrivateImpl {}
+//~^ ERROR trait `OtherTrait` from private dependency 'priv_dep' in public interface
 
 pub trait PubTraitOnPrivate {}
 
-// FIXME: This should trigger.
-// See https://github.com/rust-lang/rust/issues/71043
 impl PubTraitOnPrivate for OtherType {}
+//~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
 
 pub struct AllowedPrivType {
     #[allow(exported_private_dependencies)]
     pub allowed: OtherType,
 }
 
-// FIXME: This should trigger.
 pub use priv_dep::m;
-// FIXME: This should trigger.
+//~^ ERROR `use` import `m` from private dependency 'priv_dep' in public interface
 pub use pm::fn_like;
-// FIXME: This should trigger.
+//~^ ERROR `use` import `fn_like` from private dependency 'pm' in public interface
 pub use pm::PmDerive;
-// FIXME: This should trigger.
+//~^ ERROR `use` import `PmDerive` from private dependency 'pm' in public interface
 pub use pm::pm_attr;
-
-// FIXME: This should trigger.
+//~^ ERROR `use` import `pm_attr` from private dependency 'pm' in public interface
 pub use priv_dep::E::V1;
+//~^ ERROR `use` import `V1` from private dependency 'priv_dep' in public interface
+pub use priv_dep::*;
+//~^ ERROR `use` import `priv_dep` from private dependency 'priv_dep' in public interface
 
 fn main() {}

tests/ui/privacy/pub-priv-dep/pub-priv1.stderr

@@ -1,8 +1,8 @@
-error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:29:5
+error: extern crate `priv_dep` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:13:1
    |
-LL |     pub field: OtherType,
-   |     ^^^^^^^^^^^^^^^^^^^^
+LL | pub extern crate priv_dep;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/pub-priv1.rs:9:9
@@ -11,64 +11,118 @@ LL | #![deny(exported_private_dependencies)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:36:5
+  --> $DIR/pub-priv1.rs:30:5
+   |
+LL |     pub field: OtherType,
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:37:5
    |
 LL |     pub fn pub_fn_param(param: OtherType) {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:39:5
+  --> $DIR/pub-priv1.rs:40:5
    |
 LL |     pub fn pub_fn_return() -> OtherType { OtherType }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:46:5
+  --> $DIR/pub-priv1.rs:47:5
    |
 LL |     type Foo: OtherTrait;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:50:1
+  --> $DIR/pub-priv1.rs:51:1
    |
 LL | pub trait WithSuperTrait: OtherTrait {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:59:5
+  --> $DIR/pub-priv1.rs:60:5
    |
 LL |     type X = OtherType;
    |     ^^^^^^
 
 error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:63:1
+  --> $DIR/pub-priv1.rs:64:1
    |
 LL | pub fn in_bounds<T: OtherTrait>(x: T) { unimplemented!() }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:66:1
+  --> $DIR/pub-priv1.rs:67:1
    |
 LL | pub fn private_in_generic() -> std::num::Saturating<OtherType> { unimplemented!() }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:69:1
+  --> $DIR/pub-priv1.rs:70:1
    |
 LL | pub static STATIC: OtherType = OtherType;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:72:1
+  --> $DIR/pub-priv1.rs:73:1
    |
 LL | pub const CONST: OtherType = OtherType;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: type `OtherType` from private dependency 'priv_dep' in public interface
-  --> $DIR/pub-priv1.rs:75:1
+  --> $DIR/pub-priv1.rs:76:1
    |
 LL | pub type Alias = OtherType;
    | ^^^^^^^^^^^^^^
 
-error: aborting due to 11 previous errors
+error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:81:1
+   |
+LL | impl OtherTrait for PublicWithPrivateImpl {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type `OtherType` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:86:1
+   |
+LL | impl PubTraitOnPrivate for OtherType {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `use` import `m` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:94:9
+   |
+LL | pub use priv_dep::m;
+   |         ^^^^^^^^^^^
+
+error: `use` import `fn_like` from private dependency 'pm' in public interface
+  --> $DIR/pub-priv1.rs:96:9
+   |
+LL | pub use pm::fn_like;
+   |         ^^^^^^^^^^^
+
+error: `use` import `PmDerive` from private dependency 'pm' in public interface
+  --> $DIR/pub-priv1.rs:98:9
+   |
+LL | pub use pm::PmDerive;
+   |         ^^^^^^^^^^^^
+
+error: `use` import `pm_attr` from private dependency 'pm' in public interface
+  --> $DIR/pub-priv1.rs:100:9
+   |
+LL | pub use pm::pm_attr;
+   |         ^^^^^^^^^^^
+
+error: `use` import `V1` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:102:9
+   |
+LL | pub use priv_dep::E::V1;
+   |         ^^^^^^^^^^^^^^^
+
+error: `use` import `priv_dep` from private dependency 'priv_dep' in public interface
+  --> $DIR/pub-priv1.rs:104:9
+   |
+LL | pub use priv_dep::*;
+   |         ^^^^^^^^
+
+error: aborting due to 20 previous errors