resolve: Migrate a special ambiguity for glob vs non-glob bindings

in the same module to the usual ambiguity infra in `resolve_ident_in_scope_set`

compiler/rustc_resolve/src/ident.rs

@@ -783,9 +783,18 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             Some(AmbiguityKind::GlobVsOuter)
         } else if innermost_binding.may_appear_after(parent_scope.expansion, binding) {
             Some(AmbiguityKind::MoreExpandedVsOuter)
+        } else if innermost_binding.expansion != LocalExpnId::ROOT
+            && let Scope::ModuleGlobs(m1, _) = scope
+            && let Scope::ModuleNonGlobs(m2, _) = innermost_scope
+            && m1 == m2
+        {
+            // FIXME: this error is too conservative and technically unnecessary now when module
+            // scope is split into two scopes, remove it with lang team approval.
+            Some(AmbiguityKind::GlobVsExpanded)
         } else {
             None
         };
+
         if let Some(kind) = ambiguity_error_kind {
             // Skip ambiguity errors for extern flag bindings "overridden"
             // by extern item bindings.
@@ -1008,7 +1017,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             return self.get_mut().finalize_module_binding(
                 ident,
                 binding,
-                if resolution.non_glob_binding.is_some() { resolution.glob_binding } else { None },
                 parent_scope,
                 module,
                 finalize,
@@ -1070,7 +1078,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             return self.get_mut().finalize_module_binding(
                 ident,
                 binding,
-                if resolution.non_glob_binding.is_some() { resolution.glob_binding } else { None },
                 parent_scope,
                 module,
                 finalize,
@@ -1182,7 +1189,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         &mut self,
         ident: Ident,
         binding: Option<NameBinding<'ra>>,
-        shadowed_glob: Option<NameBinding<'ra>>,
         parent_scope: &ParentScope<'ra>,
         module: Module<'ra>,
         finalize: Finalize,
@@ -1210,24 +1216,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             }
         }
 
-        // Forbid expanded shadowing to avoid time travel.
-        if let Some(shadowed_glob) = shadowed_glob
-            && shadowing == Shadowing::Restricted
-            && finalize.stage == Stage::Early
-            && binding.expansion != LocalExpnId::ROOT
-            && binding.res() != shadowed_glob.res()
-        {
-            self.ambiguity_errors.push(AmbiguityError {
-                kind: AmbiguityKind::GlobVsExpanded,
-                ident,
-                b1: binding,
-                b2: shadowed_glob,
-                scope1: Scope::ModuleGlobs(self.empty_module, None),
-                scope2: Scope::ModuleGlobs(self.empty_module, None),
-                warning: false,
-            });
-        }
-
         if shadowing == Shadowing::Unrestricted
             && binding.expansion != LocalExpnId::ROOT
             && let NameBindingKind::Import { import, .. } = binding.kind

tests/ui/imports/macro-paths.rs

@@ -11,7 +11,6 @@ mod foo {
 fn f() {
     use foo::*;
     bar::m! { //~ ERROR ambiguous
-              //~| ERROR `bar` is ambiguous
         mod bar { pub use two_macros::m; }
     }
 }

tests/ui/imports/macro-paths.stderr

@@ -1,22 +1,3 @@
-error[E0659]: `bar` is ambiguous
-  --> $DIR/macro-paths.rs:13:5
-   |
-LL |     bar::m! {
-   |     ^^^ ambiguous name
-   |
-   = note: ambiguous because of a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution
-note: `bar` could refer to the module defined here
-  --> $DIR/macro-paths.rs:15:9
-   |
-LL |         mod bar { pub use two_macros::m; }
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `bar` could also refer to the module imported here
-  --> $DIR/macro-paths.rs:12:9
-   |
-LL |     use foo::*;
-   |         ^^^^^^
-   = help: consider adding an explicit import of `bar` to disambiguate
-
 error[E0659]: `bar` is ambiguous
   --> $DIR/macro-paths.rs:13:5
    |
@@ -25,7 +6,7 @@ LL |     bar::m! {
    |
    = note: ambiguous because of a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution
 note: `bar` could refer to the module defined here
-  --> $DIR/macro-paths.rs:15:9
+  --> $DIR/macro-paths.rs:14:9
    |
 LL |         mod bar { pub use two_macros::m; }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -36,19 +17,19 @@ LL |     use foo::*;
    |         ^^^^^^
 
 error[E0659]: `baz` is ambiguous
-  --> $DIR/macro-paths.rs:24:5
+  --> $DIR/macro-paths.rs:23:5
    |
 LL |     baz::m! {
    |     ^^^ ambiguous name
    |
    = note: ambiguous because of a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution
 note: `baz` could refer to the module defined here
-  --> $DIR/macro-paths.rs:25:9
+  --> $DIR/macro-paths.rs:24:9
    |
 LL |         mod baz { pub use two_macros::m; }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: `baz` could also refer to the module defined here
-  --> $DIR/macro-paths.rs:19:1
+  --> $DIR/macro-paths.rs:18:1
    |
 LL | / pub mod baz {
 LL | |     pub use two_macros::m;
@@ -56,6 +37,6 @@ LL | | }
    | |_^
    = help: use `crate::baz` to refer to this module unambiguously
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0659`.