Clarify error messages caused by re-exporting pub(crate) visibility…

… to outside

compiler/rustc_resolve/src/imports.rs

@@ -1180,11 +1180,17 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
         let mut reexport_error = None;
         let mut any_successful_reexport = false;
+        let mut crate_private_reexport = false;
         self.r.per_ns(|this, ns| {
             if let Ok(binding) = source_bindings[ns].get() {
                 let vis = import.vis.get();
                 if !binding.vis.is_at_least(vis, &*this) {
                     reexport_error = Some((ns, binding));
+                    if let ty::Visibility::Restricted(binding_def_id) = binding.vis {
+                        if binding_def_id.is_top_level_module() {
+                            crate_private_reexport = true;
+                        }
+                    }
                 } else {
                     any_successful_reexport = true;
                 }
@@ -1207,24 +1213,34 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                     import.span,
                     &msg,
                 );
-            } else if ns == TypeNS {
-                struct_span_err!(
-                    self.r.session,
-                    import.span,
-                    E0365,
-                    "`{}` is private, and cannot be re-exported",
-                    ident
-                )
-                .span_label(import.span, format!("re-export of private `{}`", ident))
-                .note(&format!("consider declaring type or module `{}` with `pub`", ident))
-                .emit();
             } else {
-                let msg = format!("`{}` is private, and cannot be re-exported", ident);
-                let note_msg =
-                    format!("consider marking `{}` as `pub` in the imported module", ident,);
-                struct_span_err!(self.r.session, import.span, E0364, "{}", &msg)
-                    .span_note(import.span, &note_msg)
-                    .emit();
+                let error_msg = if crate_private_reexport {
+                    format!(
+                        "`{}` is only public within the crate, and cannot be re-exported outside",
+                        ident
+                    )
+                } else {
+                    format!("`{}` is private, and cannot be re-exported", ident)
+                };
+
+                if ns == TypeNS {
+                    let label_msg = if crate_private_reexport {
+                        format!("re-export of crate public `{}`", ident)
+                    } else {
+                        format!("re-export of private `{}`", ident)
+                    };
+
+                    struct_span_err!(self.r.session, import.span, E0365, "{}", error_msg)
+                        .span_label(import.span, label_msg)
+                        .note(&format!("consider declaring type or module `{}` with `pub`", ident))
+                        .emit();
+                } else {
+                    let note_msg =
+                        format!("consider marking `{}` as `pub` in the imported module", ident);
+                    struct_span_err!(self.r.session, import.span, E0364, "{}", error_msg)
+                        .span_note(import.span, &note_msg)
+                        .emit();
+                }
             }
         }
 

src/test/ui/error-codes/E0365.rs

@@ -3,6 +3,6 @@ mod foo {
 }
 
 pub use foo as foo2;
-//~^ ERROR `foo` is private, and cannot be re-exported [E0365]
+//~^ ERROR `foo` is only public within the crate, and cannot be re-exported outside [E0365]
 
 fn main() {}

src/test/ui/error-codes/E0365.stderr

@@ -1,8 +1,8 @@
-error[E0365]: `foo` is private, and cannot be re-exported
+error[E0365]: `foo` is only public within the crate, and cannot be re-exported outside
   --> $DIR/E0365.rs:5:9
    |
 LL | pub use foo as foo2;
-   |         ^^^^^^^^^^^ re-export of private `foo`
+   |         ^^^^^^^^^^^ re-export of crate public `foo`
    |
    = note: consider declaring type or module `foo` with `pub`
 

src/test/ui/modules/issue-56411.rs

@@ -5,7 +5,7 @@ macro_rules! import {
             mod $name;
             pub use self::$name;
             //~^ ERROR the name `issue_56411_aux` is defined multiple times
-            //~| ERROR `issue_56411_aux` is private, and cannot be re-exported
+            //~| ERROR `issue_56411_aux` is only public within the crate, and cannot be re-exported outside
 
         )*
     }

src/test/ui/modules/issue-56411.stderr

@@ -15,11 +15,11 @@ LL | import!(("issue-56411-aux.rs", issue_56411_aux));
    = note: `issue_56411_aux` must be defined only once in the type namespace of this module
    = note: this error originates in the macro `import` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0365]: `issue_56411_aux` is private, and cannot be re-exported
+error[E0365]: `issue_56411_aux` is only public within the crate, and cannot be re-exported outside
   --> $DIR/issue-56411.rs:6:21
    |
 LL |             pub use self::$name;
-   |                     ^^^^^^^^^^^ re-export of private `issue_56411_aux`
+   |                     ^^^^^^^^^^^ re-export of crate public `issue_56411_aux`
 ...
 LL | import!(("issue-56411-aux.rs", issue_56411_aux));
    | ------------------------------------------------ in this macro invocation

src/test/ui/privacy/crate-private-reexport.rs

@@ -0,0 +1,66 @@
+fn f1() {}
+enum E1 { V }
+struct S1 {
+    #[rustfmt::skip]
+    bar: i32,
+}
+mod m1 {
+    pub use ::f1; //~ ERROR `f1` is only public within the crate, and cannot be re-exported outside
+    pub use ::S1; //~ ERROR `S1` is only public within the crate, and cannot be re-exported outside
+    pub use ::E1; //~ ERROR `E1` is only public within the crate, and cannot be re-exported outside
+    pub use ::E1::V; //~ ERROR `V` is only public within the crate, and cannot be re-exported outside
+}
+
+pub(crate) fn f2() {}
+pub(crate) enum E2 {
+    V
+}
+pub(crate) struct S2 {
+    #[rustfmt::skip]
+    bar: i32,
+}
+mod m2 {
+    pub use ::f2; //~ ERROR `f2` is only public within the crate, and cannot be re-exported outside
+    pub use ::S2; //~ ERROR `S2` is only public within the crate, and cannot be re-exported outside
+    pub use ::E2; //~ ERROR `E2` is only public within the crate, and cannot be re-exported outside
+    pub use ::E2::V; //~ ERROR `V` is only public within the crate, and cannot be re-exported outside
+}
+
+mod m3 {
+    pub(crate) fn f3() {}
+    pub(crate) enum E3 {
+        V
+    }
+    pub(crate) struct S3 {
+        #[rustfmt::skip]
+        bar: i32,
+    }
+}
+pub use m3::f3; //~ ERROR `f3` is only public within the crate, and cannot be re-exported outside
+pub use m3::S3; //~ ERROR `S3` is only public within the crate, and cannot be re-exported outside
+pub use m3::E3; //~ ERROR `E3` is only public within the crate, and cannot be re-exported outside
+pub use m3::E3::V; //~ ERROR `V` is only public within the crate, and cannot be re-exported outside
+
+pub(self) fn f4() {}
+pub use ::f4 as f5; //~ ERROR `f4` is only public within the crate, and cannot be re-exported outside
+
+pub mod m10 {
+    pub mod m {
+        pub(super) fn f6() {}
+        pub(crate) fn f7() {}
+        pub(in crate::m10) fn f8() {}
+    }
+    pub use self::m::f6; //~ ERROR `f6` is private, and cannot be re-exported
+    pub use self::m::f7; //~ ERROR `f7` is only public within the crate, and cannot be re-exported outside
+    pub use self::m::f8; //~ ERROR `f8` is private, and cannot be re-exported
+}
+pub use m10::m::f6; //~ ERROR function `f6` is private
+pub use m10::m::f7; //~ ERROR `f7` is only public within the crate, and cannot be re-exported outside
+pub use m10::m::f8; //~ ERROR function `f8` is private
+
+pub mod m11 {
+    pub(self) fn f9() {}
+}
+pub use m11::f9; //~ ERROR function `f9` is private
+
+fn main() {}

src/test/ui/privacy/crate-private-reexport.stderr

@@ -0,0 +1,220 @@
+error[E0364]: `f1` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:8:13
+   |
+LL |     pub use ::f1;
+   |             ^^^^
+   |
+note: consider marking `f1` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:8:13
+   |
+LL |     pub use ::f1;
+   |             ^^^^
+
+error[E0365]: `S1` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:9:13
+   |
+LL |     pub use ::S1;
+   |             ^^^^ re-export of crate public `S1`
+   |
+   = note: consider declaring type or module `S1` with `pub`
+
+error[E0365]: `E1` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:10:13
+   |
+LL |     pub use ::E1;
+   |             ^^^^ re-export of crate public `E1`
+   |
+   = note: consider declaring type or module `E1` with `pub`
+
+error[E0364]: `V` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:11:13
+   |
+LL |     pub use ::E1::V;
+   |             ^^^^^^^
+   |
+note: consider marking `V` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:11:13
+   |
+LL |     pub use ::E1::V;
+   |             ^^^^^^^
+
+error[E0364]: `f2` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:23:13
+   |
+LL |     pub use ::f2;
+   |             ^^^^
+   |
+note: consider marking `f2` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:23:13
+   |
+LL |     pub use ::f2;
+   |             ^^^^
+
+error[E0365]: `S2` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:24:13
+   |
+LL |     pub use ::S2;
+   |             ^^^^ re-export of crate public `S2`
+   |
+   = note: consider declaring type or module `S2` with `pub`
+
+error[E0365]: `E2` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:25:13
+   |
+LL |     pub use ::E2;
+   |             ^^^^ re-export of crate public `E2`
+   |
+   = note: consider declaring type or module `E2` with `pub`
+
+error[E0364]: `V` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:26:13
+   |
+LL |     pub use ::E2::V;
+   |             ^^^^^^^
+   |
+note: consider marking `V` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:26:13
+   |
+LL |     pub use ::E2::V;
+   |             ^^^^^^^
+
+error[E0364]: `f3` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:39:9
+   |
+LL | pub use m3::f3;
+   |         ^^^^^^
+   |
+note: consider marking `f3` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:39:9
+   |
+LL | pub use m3::f3;
+   |         ^^^^^^
+
+error[E0365]: `S3` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:40:9
+   |
+LL | pub use m3::S3;
+   |         ^^^^^^ re-export of crate public `S3`
+   |
+   = note: consider declaring type or module `S3` with `pub`
+
+error[E0365]: `E3` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:41:9
+   |
+LL | pub use m3::E3;
+   |         ^^^^^^ re-export of crate public `E3`
+   |
+   = note: consider declaring type or module `E3` with `pub`
+
+error[E0364]: `V` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:42:9
+   |
+LL | pub use m3::E3::V;
+   |         ^^^^^^^^^
+   |
+note: consider marking `V` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:42:9
+   |
+LL | pub use m3::E3::V;
+   |         ^^^^^^^^^
+
+error[E0364]: `f4` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:45:9
+   |
+LL | pub use ::f4 as f5;
+   |         ^^^^^^^^^^
+   |
+note: consider marking `f4` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:45:9
+   |
+LL | pub use ::f4 as f5;
+   |         ^^^^^^^^^^
+
+error[E0364]: `f6` is private, and cannot be re-exported
+  --> $DIR/crate-private-reexport.rs:53:13
+   |
+LL |     pub use self::m::f6;
+   |             ^^^^^^^^^^^
+   |
+note: consider marking `f6` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:53:13
+   |
+LL |     pub use self::m::f6;
+   |             ^^^^^^^^^^^
+
+error[E0364]: `f7` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:54:13
+   |
+LL |     pub use self::m::f7;
+   |             ^^^^^^^^^^^
+   |
+note: consider marking `f7` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:54:13
+   |
+LL |     pub use self::m::f7;
+   |             ^^^^^^^^^^^
+
+error[E0364]: `f8` is private, and cannot be re-exported
+  --> $DIR/crate-private-reexport.rs:55:13
+   |
+LL |     pub use self::m::f8;
+   |             ^^^^^^^^^^^
+   |
+note: consider marking `f8` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:55:13
+   |
+LL |     pub use self::m::f8;
+   |             ^^^^^^^^^^^
+
+error[E0364]: `f7` is only public within the crate, and cannot be re-exported outside
+  --> $DIR/crate-private-reexport.rs:58:9
+   |
+LL | pub use m10::m::f7;
+   |         ^^^^^^^^^^
+   |
+note: consider marking `f7` as `pub` in the imported module
+  --> $DIR/crate-private-reexport.rs:58:9
+   |
+LL | pub use m10::m::f7;
+   |         ^^^^^^^^^^
+
+error[E0603]: function `f6` is private
+  --> $DIR/crate-private-reexport.rs:57:17
+   |
+LL | pub use m10::m::f6;
+   |                 ^^ private function
+   |
+note: the function `f6` is defined here
+  --> $DIR/crate-private-reexport.rs:49:9
+   |
+LL |         pub(super) fn f6() {}
+   |         ^^^^^^^^^^^^^^^^^^
+
+error[E0603]: function `f8` is private
+  --> $DIR/crate-private-reexport.rs:59:17
+   |
+LL | pub use m10::m::f8;
+   |                 ^^ private function
+   |
+note: the function `f8` is defined here
+  --> $DIR/crate-private-reexport.rs:51:9
+   |
+LL |         pub(in crate::m10) fn f8() {}
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0603]: function `f9` is private
+  --> $DIR/crate-private-reexport.rs:64:14
+   |
+LL | pub use m11::f9;
+   |              ^^ private function
+   |
+note: the function `f9` is defined here
+  --> $DIR/crate-private-reexport.rs:62:5
+   |
+LL |     pub(self) fn f9() {}
+   |     ^^^^^^^^^^^^^^^^^
+
+error: aborting due to 20 previous errors
+
+Some errors have detailed explanations: E0364, E0365, E0603.
+For more information about an error, try `rustc --explain E0364`.