Use empty typeck tables when nesting on items without those

Author: Xanewok

src/librustc_save_analysis/dump_visitor.rs

@@ -115,15 +115,17 @@ impl<'l, 'tcx> DumpVisitor<'l, 'tcx> {
         F: FnOnce(&mut Self),
     {
         let item_def_id = self.tcx.hir().local_def_id_from_node_id(item_id);
-        if self.tcx.has_typeck_tables(item_def_id) {
-            let tables = self.tcx.typeck_tables_of(item_def_id);
-            let old_tables = self.save_ctxt.tables;
-            self.save_ctxt.tables = tables;
-            f(self);
-            self.save_ctxt.tables = old_tables;
+
+        let tables = if self.tcx.has_typeck_tables(item_def_id) {
+            self.tcx.typeck_tables_of(item_def_id)
         } else {
-            f(self);
-        }
+            self.save_ctxt.empty_tables
+        };
+
+        let old_tables = self.save_ctxt.tables;
+        self.save_ctxt.tables = tables;
+        f(self);
+        self.save_ctxt.tables = old_tables;
     }
 
     fn span_from_span(&self, span: Span) -> SpanData {

src/librustc_save_analysis/lib.rs

@@ -49,6 +49,9 @@ use log::{debug, error, info};
 pub struct SaveContext<'l, 'tcx> {
     tcx: TyCtxt<'tcx>,
     tables: &'l ty::TypeckTables<'tcx>,
+    /// Used as a fallback when nesting the typeck tables during item processing
+    /// (if these are not available for that item, e.g. don't own a body)
+    empty_tables: &'l ty::TypeckTables<'tcx>,
     access_levels: &'l AccessLevels,
     span_utils: SpanUtils<'tcx>,
     config: Config,
@@ -1115,6 +1118,7 @@ pub fn process_crate<'l, 'tcx, H: SaveHandler>(
         let save_ctxt = SaveContext {
             tcx,
             tables: &ty::TypeckTables::empty(None),
+            empty_tables: &ty::TypeckTables::empty(None),
             access_levels: &access_levels,
             span_utils: SpanUtils::new(&tcx.sess),
             config: find_config(config),