Auto merge of #145166 - makai410:teach-pub-crate, r=<try>

suggest using `pub(crate)` for E0364

Author: rust-bors[bot]

compiler/rustc_resolve/messages.ftl

@@ -93,6 +93,9 @@ resolve_consider_adding_a_derive =
 resolve_consider_adding_macro_export =
     consider adding a `#[macro_export]` to the macro in the imported module
 
+resolve_consider_marking_as_pub_crate =
+    or if you want to use the macro within this crate only, reduce the visibility to `pub(crate)`
+
 resolve_consider_declaring_with_pub =
     consider declaring type or module `{$ident}` with `pub`
 

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -474,6 +474,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             root_span,
             root_id,
             vis,
+            vis_span: item.vis.span,
         });
 
         self.r.indeterminate_imports.push(import);
@@ -963,6 +964,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             span: item.span,
             module_path: Vec::new(),
             vis,
+            vis_span: item.vis.span,
         });
         if used {
             self.r.import_use_map.insert(import, Used::Other);
@@ -1102,6 +1104,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                 span,
                 module_path: Vec::new(),
                 vis: Visibility::Restricted(CRATE_DEF_ID),
+                vis_span: item.vis.span,
             })
         };
 
@@ -1271,6 +1274,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                     span,
                     module_path: Vec::new(),
                     vis,
+                    vis_span: item.vis.span,
                 });
                 self.r.import_use_map.insert(import, Used::Other);
                 let import_binding = self.r.import(binding, import);

compiler/rustc_resolve/src/errors.rs

@@ -769,6 +769,17 @@ pub(crate) struct ConsiderAddingMacroExport {
     pub(crate) span: Span,
 }
 
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_consider_marking_as_pub_crate,
+    code = "pub(crate)",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct ConsiderMarkingAsPubCrate {
+    #[primary_span]
+    pub(crate) vis_span: Span,
+}
+
 #[derive(Subdiagnostic)]
 #[note(resolve_consider_marking_as_pub)]
 pub(crate) struct ConsiderMarkingAsPub {

compiler/rustc_resolve/src/imports.rs

@@ -30,7 +30,7 @@ use crate::diagnostics::{DiagMode, Suggestion, import_candidates};
 use crate::errors::{
     CannotBeReexportedCratePublic, CannotBeReexportedCratePublicNS, CannotBeReexportedPrivate,
     CannotBeReexportedPrivateNS, CannotDetermineImportResolution, CannotGlobImportAllCrates,
-    ConsiderAddingMacroExport, ConsiderMarkingAsPub,
+    ConsiderAddingMacroExport, ConsiderMarkingAsPub, ConsiderMarkingAsPubCrate,
 };
 use crate::{
     AmbiguityError, AmbiguityKind, BindingKey, CmResolver, Determinacy, Finalize, ImportSuggestion,
@@ -188,6 +188,9 @@ pub(crate) struct ImportData<'ra> {
     /// |`use foo`        | `ModuleOrUniformRoot::CurrentScope`           | - |
     pub imported_module: Cell<Option<ModuleOrUniformRoot<'ra>>>,
     pub vis: Visibility,
+
+    /// Span of the visibility.
+    pub vis_span: Span,
 }
 
 /// All imports are unique and allocated on a same arena,
@@ -1373,6 +1376,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             err.subdiagnostic( ConsiderAddingMacroExport {
                                 span: binding.span,
                             });
+                            err.subdiagnostic( ConsiderMarkingAsPubCrate {
+                                vis_span: import.vis_span,
+                            });
                         }
                         _ => {
                             err.subdiagnostic( ConsiderMarkingAsPub {

tests/ui/privacy/macro-private-reexport.stderr

@@ -11,6 +11,10 @@ LL | /     macro_rules! bar {
 LL | |         () => {};
 LL | |     }
    | |_____^
+help: or if you want to use the macro within this crate only, reduce the visibility to `pub(crate)`
+   |
+LL |     pub(crate) use bar as _;
+   |        +++++++
 
 error[E0364]: `baz` is private, and cannot be re-exported
   --> $DIR/macro-private-reexport.rs:14:13

tests/ui/rust-2018/uniform-paths/macro-rules.stderr

@@ -9,6 +9,10 @@ help: consider adding a `#[macro_export]` to the macro in the imported module
    |
 LL |     macro_rules! legacy_macro { () => () }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: or if you want to use the macro within this crate only, reduce the visibility to `pub(crate)`
+   |
+LL |     pub(crate) use legacy_macro as _;
+   |        +++++++
 
 error: aborting due to 1 previous error