Auto merge of #29291 - petrochenkov:privacy, r=alexcrichton

The public set is expanded with trait items, impls and their items, foreign items, exported macros, variant fields, i.e. all the missing parts. Now it's a subset of the exported set.
This is needed for #29083 because stability annotation pass uses the public set and all things listed above need to be annotated.
Rustdoc can now be migrated to the public set as well, I guess.

Exported set is now slightly more correct with regard to exported items in blocks - 1) blocks in foreign items are considered and 2) publicity is not inherited from the block's parent - if a function is public it doesn't mean structures defined in its body are public.

r? @alexcrichton or maybe someone else

src/librustc/middle/reachable.rs

@@ -125,16 +125,11 @@ impl<'a, 'tcx, 'v> Visitor<'v> for ReachableContext<'a, 'tcx> {
             hir::ExprMethodCall(..) => {
                 let method_call = ty::MethodCall::expr(expr.id);
                 let def_id = self.tcx.tables.borrow().method_map[&method_call].def_id;
-                match self.tcx.impl_or_trait_item(def_id).container() {
-                    ty::ImplContainer(_) => {
-                        if let Some(node_id) = self.tcx.map.as_local_node_id(def_id) {
-                            if self.def_id_represents_local_inlined_item(def_id) {
-                                self.worklist.push(node_id)
-                            }
-                            self.reachable_symbols.insert(node_id);
-                        }
+                if let Some(node_id) = self.tcx.map.as_local_node_id(def_id) {
+                    if self.def_id_represents_local_inlined_item(def_id) {
+                        self.worklist.push(node_id)
                     }
-                    ty::TraitContainer(_) => {}
+                    self.reachable_symbols.insert(node_id);
                 }
             }
             _ => {}
@@ -228,14 +223,8 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
                 continue
             }
 
-            match self.tcx.map.find(search_item) {
-                Some(ref item) => self.propagate_node(item, search_item),
-                None if search_item == ast::CRATE_NODE_ID => {}
-                None => {
-                    self.tcx.sess.bug(&format!("found unmapped ID in worklist: \
-                                               {}",
-                                              search_item))
-                }
+            if let Some(ref item) = self.tcx.map.find(search_item) {
+                self.propagate_node(item, search_item);
             }
         }
     }

src/librustc/middle/stability.rs

@@ -217,7 +217,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for Annotator<'a, 'tcx> {
 
     fn visit_impl_item(&mut self, ii: &hir::ImplItem) {
         self.annotate(ii.id, true, &ii.attrs, ii.span,
-                      |v| visit::walk_impl_item(v, ii), true);
+                      |v| visit::walk_impl_item(v, ii), false);
     }
 
     fn visit_variant(&mut self, var: &Variant, g: &'v Generics, item_id: NodeId) {
@@ -227,7 +227,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for Annotator<'a, 'tcx> {
 
     fn visit_struct_field(&mut self, s: &StructField) {
         self.annotate(s.node.id, true, &s.node.attrs, s.span,
-                      |v| visit::walk_struct_field(v, s), true);
+                      |v| visit::walk_struct_field(v, s), !s.node.kind.is_unnamed());
     }
 
     fn visit_foreign_item(&mut self, i: &hir::ForeignItem) {

src/librustc_front/hir.rs

@@ -1148,6 +1148,12 @@ impl StructFieldKind {
             NamedField(..) => false,
         }
     }
+
+    pub fn visibility(&self) -> Visibility {
+        match *self {
+            NamedField(_, vis) | UnnamedField(vis) => vis
+        }
+    }
 }
 
 /// Fields and Ids of enum variants and structs