fix: Failed to lookup MACRO_CALL@... in this Semantics due to include!

crates/hir/src/semantics/source_to_def.rs

@@ -165,9 +165,21 @@ impl<'db> SourceToDefCache<'db> {
         self.expansion_info_cache.entry(macro_file).or_insert_with(|| {
             let exp_info = macro_file.expansion_info(db);
 
+            // Ensure that the cache contains syntax nodes from expanded macros,
+            // whose root may be in another file.
             let InMacroFile { file_id, value } = exp_info.expanded();
             Self::cache(&mut self.root_to_file_cache, value, file_id.into());
 
+            // include!("foo.rs") invocations are awkward: in addition to the
+            // expansion site there's the included file (foo.rs), so we need to
+            // ensure that it exists in the cache too.
+            if macro_file.is_include_macro(db) {
+                let arg = exp_info.arg();
+                if let Some(arg_node) = arg.value {
+                    Self::cache(&mut self.root_to_file_cache, arg_node.tree_top(), arg.file_id);
+                }
+            }
+
             exp_info
         })
     }

crates/ide-assists/src/handlers/inline_macro.rs

@@ -175,6 +175,23 @@ macro_rules! num {
         );
     }
 
+    #[test]
+    fn inline_macro_in_included_file() {
+        // Regression test for climbing from the included file into an uncached includer root.
+        check_assist_not_applicable(
+            inline_macro,
+            r#"
+//- minicore:include
+//- /main.rs
+include!("a.rs");
+//- /a.rs
+fn foo() {
+    let x = 1$0;
+}
+"#,
+        );
+    }
+
     #[test]
     fn inline_macro_simple_not_applicable_broken_macro() {
         // FIXME: This is a bug. The macro should not expand, but it's