Support resolution of #[macro_use] extern crate

crates/ra_hir/src/nameres/collector.rs

@@ -295,6 +295,23 @@ where
                         }
                     }
 
+                    // `#[macro_use] extern crate` glob import macros
+                    if import.is_extern_crate && import.is_macro_use {
+                        if let Some(ModuleDef::Module(m)) =
+                            def.a().and_then(|item| item.take_types())
+                        {
+                            let item_map = self.db.crate_def_map(m.krate);
+                            let scope = &item_map[m.module_id].scope;
+                            let macros = scope
+                                .macros
+                                .iter()
+                                .map(|(name, res)| (name.clone(), Either::B(*res)))
+                                .collect::<Vec<_>>();
+
+                            self.update(module_id, Some(import_id), &macros);
+                        }
+                    }
+
                     let resolution = match def {
                         Either::A(item) => {
                             Either::A(Resolution { def: item, import: Some(import_id) })

crates/ra_hir/src/nameres/raw.rs

@@ -154,6 +154,7 @@ pub struct ImportData {
     pub(super) is_glob: bool,
     pub(super) is_prelude: bool,
     pub(super) is_extern_crate: bool,
+    pub(super) is_macro_use: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -293,8 +294,14 @@ impl RawItemsCollector {
         let is_prelude = use_item.has_atom_attr("prelude_import");
 
         Path::expand_use_item(&use_item, |path, use_tree, is_glob, alias| {
-            let import_data =
-                ImportData { path, alias, is_glob, is_prelude, is_extern_crate: false };
+            let import_data = ImportData {
+                path,
+                alias,
+                is_glob,
+                is_prelude,
+                is_extern_crate: false,
+                is_macro_use: false,
+            };
             self.push_import(current_module, import_data, Either::A(AstPtr::new(use_tree)));
         })
     }
@@ -307,12 +314,14 @@ impl RawItemsCollector {
         if let Some(name_ref) = extern_crate.name_ref() {
             let path = Path::from_name_ref(&name_ref);
             let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
+            let is_macro_use = extern_crate.has_atom_attr("macro_use");
             let import_data = ImportData {
                 path,
                 alias,
                 is_glob: false,
                 is_prelude: false,
                 is_extern_crate: true,
+                is_macro_use,
             };
             self.push_import(current_module, import_data, Either::B(AstPtr::new(&extern_crate)));
         }

crates/ra_syntax/src/ast/generated.rs

@@ -934,6 +934,7 @@ impl AstNode for ExternCrateItem {
         &self.syntax
     }
 }
+impl ast::AttrsOwner for ExternCrateItem {}
 impl ExternCrateItem {
     pub fn name_ref(&self) -> Option<NameRef> {
         AstChildren::new(&self.syntax).next()

crates/ra_syntax/src/grammar.ron

@@ -669,6 +669,7 @@ Grammar(
             collections: [("use_trees", "UseTree")]
         ),
         "ExternCrateItem": (
+            traits: ["AttrsOwner"],
             options: ["NameRef", "Alias"],
         ),
         "ArgList": (