1 files changed, 9 insertions, 2 deletions

diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index 42b50b5b7..b50923747 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -81,7 +81,13 @@ pub struct ModuleId {
 impl ModuleId {
     pub fn def_map(&self, db: &dyn db::DefDatabase) -> Arc<DefMap> {
         match self.block {
-            Some(block) => db.block_def_map(block),
+            Some(block) => {
+                db.block_def_map(block).unwrap_or_else(|| {
+                    // NOTE: This should be unreachable - all `ModuleId`s come from their `DefMap`s,
+                    // so the `DefMap` here must exist.
+                    panic!("no `block_def_map` for `ModuleId` {:?}", self);
+                })
+            }
             None => db.crate_def_map(self.krate),
         }
     }
@@ -239,6 +245,7 @@ pub struct BlockId(salsa::InternId);
 #[derive(Debug, Hash, PartialEq, Eq, Clone)]
 pub struct BlockLoc {
     ast_id: AstId<ast::BlockExpr>,
+    /// The containing module.
     module: ModuleId,
 }
 impl_intern!(BlockId, BlockLoc, intern_block, lookup_intern_block);
@@ -655,7 +662,7 @@ impl AsMacroCall for AstIdWithPath<ast::Item> {
             def.as_lazy_macro(
                 db.upcast(),
                 krate,
-                MacroCallKind::Attr(self.ast_id, self.path.segments.last()?.to_string()),
+                MacroCallKind::Attr(self.ast_id, self.path.segments().last()?.to_string()),
             )
             .into(),
         )