From 0d23286caf35a7cd8aed6e20fab3a2a3ed91ae8f Mon Sep 17 00:00:00 2001
From: uHOOCCOOHu <hooccooh1896@gmail.com>
Date: Thu, 5 Sep 2019 11:35:13 +0800
Subject: Let `macro_use` bypass module scope

---
 crates/ra_hir/src/nameres/collector.rs | 58 ++++++++++++++++++++++------------
 1 file changed, 38 insertions(+), 20 deletions(-)

(limited to 'crates/ra_hir/src/nameres/collector.rs')

diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index dbd687236..5d1c42926 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -166,6 +166,33 @@ where
         self.global_macro_scope.insert(name, macro_id);
     }
 
+    /// Import macros from `#[macro_use] extern crate`.
+    ///
+    /// They are non-scoped, and will only be inserted into mutable `global_macro_scope`.
+    fn import_macros_from_extern_crate(&mut self, import: &raw::ImportData) {
+        log::debug!(
+            "importing macros from extern crate: {:?} ({:?})",
+            import,
+            self.def_map.edition,
+        );
+
+        let res = self.def_map.resolve_name_in_extern_prelude(
+            &import
+                .path
+                .as_ident()
+                .expect("extern crate should have been desugared to one-element path"),
+        );
+
+        if let Some(ModuleDef::Module(m)) = res.take_types() {
+            tested_by!(macro_rules_from_other_crates_are_visible_with_macro_use);
+
+            let item_map = self.db.crate_def_map(m.krate);
+            for (name, &macro_id) in &item_map.exported_macros {
+                self.global_macro_scope.insert(name.clone(), macro_id);
+            }
+        }
+    }
+
     fn resolve_imports(&mut self) -> ReachedFixedPoint {
         let mut imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
         let mut resolved = Vec::new();
@@ -299,21 +326,6 @@ where
                         }
                     }
 
-                    // `#[macro_use] extern crate` glob imports all macros exported,
-                    // ignoring their scopes
-                    if import.is_extern_crate && import.is_macro_use {
-                        if let Some(ModuleDef::Module(m)) =
-                            def.a().and_then(|item| item.take_types())
-                        {
-                            tested_by!(macro_rules_from_other_crates_are_visible_with_macro_use);
-
-                            let item_map = self.db.crate_def_map(m.krate);
-                            for (name, &macro_id) in &item_map.exported_macros {
-                                self.define_macro(module_id, name.clone(), macro_id, false);
-                            }
-                        }
-                    }
-
                     let resolution = match def {
                         Either::A(item) => {
                             Either::A(Resolution { def: item, import: Some(import_id) })
@@ -513,11 +525,17 @@ where
         for item in items {
             match *item {
                 raw::RawItem::Module(m) => self.collect_module(&self.raw_items[m]),
-                raw::RawItem::Import(import) => self.def_collector.unresolved_imports.push((
-                    self.module_id,
-                    import,
-                    self.raw_items[import].clone(),
-                )),
+                raw::RawItem::Import(import_id) => {
+                    let import = self.raw_items[import_id].clone();
+                    // This should be processed eagerly instead of deferred to resolving.
+                    // Otherwise, since it will only mutate `global_macro_scope`
+                    // without `update` names in `mod`s, unresolved macros cannot be expanded.
+                    if import.is_extern_crate && import.is_macro_use {
+                        self.def_collector.import_macros_from_extern_crate(&import);
+                    }
+
+                    self.def_collector.unresolved_imports.push((self.module_id, import_id, import));
+                }
                 raw::RawItem::Def(def) => self.define_def(&self.raw_items[def]),
                 raw::RawItem::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
             }
-- 
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