Rollup merge of #51288 - Mark-Simulacrum:delete-is-import, r=eddyb

Remove rustdoc-specific is_import field from HIR

Fixes #47100.

I believe that there is no need to check for the name being the same, as this
part of rustdoc seems to be strictly interested in exploring "public modules."
Re-exports from the same module cannot visit another module; and, re-exports
cannot export items with a greater visibility than that item declares.
Therefore, I think this code is either sufficient, or in fact does more than
is necessary, depending on whether rustdoc cares about the re-export itself.

r? @eddyb

Author: Mark-Simulacrum

src/librustc/hir/def.rs

@@ -134,9 +134,6 @@ pub struct Export {
     /// The visibility of the export.
     /// We include non-`pub` exports for hygienic macros that get used from extern crates.
     pub vis: ty::Visibility,
-    /// True if from a `use` or and `extern crate`.
-    /// Used in rustdoc.
-    pub is_import: bool,
 }
 
 impl CtorKind {

src/librustc/ich/impls_hir.rs

@@ -1115,8 +1115,7 @@ impl_stable_hash_for!(struct hir::def::Export {
     ident,
     def,
     vis,
-    span,
-    is_import
+    span
 });
 
 impl<'a> HashStable<StableHashingContext<'a>>

src/librustc_metadata/decoder.rs

@@ -665,7 +665,6 @@ impl<'a, 'tcx> CrateMetadata {
                         def: def,
                         vis: ty::Visibility::Public,
                         span: DUMMY_SP,
-                        is_import: false,
                     });
                 }
             }
@@ -705,7 +704,6 @@ impl<'a, 'tcx> CrateMetadata {
                                     ident: Ident::from_interned_str(self.item_name(child_index)),
                                     vis: self.get_visibility(child_index),
                                     span: self.entry(child_index).span.decode((self, sess)),
-                                    is_import: false,
                                 });
                             }
                         }
@@ -722,8 +720,7 @@ impl<'a, 'tcx> CrateMetadata {
                     (self.get_def(child_index), def_key.disambiguated_data.data.get_opt_name()) {
                     let ident = Ident::from_interned_str(name);
                     let vis = self.get_visibility(child_index);
-                    let is_import = false;
-                    callback(def::Export { def, ident, vis, span, is_import });
+                    callback(def::Export { def, ident, vis, span });
                     // For non-re-export structs and variants add their constructors to children.
                     // Re-export lists automatically contain constructors when necessary.
                     match def {
@@ -734,7 +731,7 @@ impl<'a, 'tcx> CrateMetadata {
                                 callback(def::Export {
                                     def: ctor_def,
                                     vis: self.get_visibility(ctor_def_id.index),
-                                    ident, span, is_import,
+                                    ident, span,
                                 });
                             }
                         }
@@ -744,7 +741,7 @@ impl<'a, 'tcx> CrateMetadata {
                             let ctor_kind = self.get_ctor_kind(child_index);
                             let ctor_def = Def::VariantCtor(def_id, ctor_kind);
                             let vis = self.get_visibility(child_index);
-                            callback(def::Export { def: ctor_def, ident, vis, span, is_import });
+                            callback(def::Export { def: ctor_def, ident, vis, span });
                         }
                         _ => {}
                     }

src/librustc_resolve/macros.rs

@@ -803,7 +803,6 @@ impl<'a> Resolver<'a> {
                     def: def,
                     vis: ty::Visibility::Public,
                     span: item.span,
-                    is_import: false,
                 });
             } else {
                 self.unused_macros.insert(def_id);

src/librustc_resolve/resolve_imports.rs

@@ -1008,7 +1008,6 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
                         def: def,
                         span: binding.span,
                         vis: binding.vis,
-                        is_import: true,
                     });
                 }
             }

src/librustdoc/visit_lib.rs

@@ -68,7 +68,8 @@ impl<'a, 'tcx, 'rcx> LibEmbargoVisitor<'a, 'tcx, 'rcx> {
         }
 
         for item in self.cx.tcx.item_children(def_id).iter() {
-            if !item.is_import || item.vis == Visibility::Public {
+            if self.cx.tcx.def_key(item.def.def_id()).parent.map_or(false, |d| d == def_id.index) ||
+                item.vis == Visibility::Public {
                 self.visit_item(item.def);
             }
         }