4 files changed, 42 insertions, 7 deletions

diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index f467ed3fe..8c1aefbf5 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -430,6 +430,7 @@ impl ExprCollector<'_> {
                         krate: Some(self.expander.module.krate),
                         ast_id: Some(self.expander.ast_id(&e)),
                         kind: MacroDefKind::Declarative,
+                        local_inner: false,
                     };
                     self.body.item_scope.define_legacy_macro(name, mac);
 
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 98c74fe25..bf3968bd6 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -204,6 +204,7 @@ impl DefCollector<'_> {
                 ast_id: None,
                 krate: Some(krate),
                 kind: MacroDefKind::CustomDerive(expander),
+                local_inner: false,
             };
 
             self.define_proc_macro(name.clone(), macro_id);
@@ -941,6 +942,7 @@ impl ModCollector<'_, '_> {
                     ast_id: Some(ast_id.ast_id),
                     krate: Some(self.def_collector.def_map.krate),
                     kind: MacroDefKind::Declarative,
+                    local_inner: mac.local_inner,
                 };
                 self.def_collector.define_macro(self.module_id, name.clone(), macro_id, mac.export);
             }
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 39b011ad7..aed9dcc72 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -188,6 +188,7 @@ pub(super) struct MacroData {
     pub(super) path: ModPath,
     pub(super) name: Option<Name>,
     pub(super) export: bool,
+    pub(super) local_inner: bool,
     pub(super) builtin: bool,
 }
 
@@ -401,14 +402,28 @@ impl RawItemsCollector {
 
         let name = m.name().map(|it| it.as_name());
         let ast_id = self.source_ast_id_map.ast_id(&m);
-        // FIXME: cfg_attr
-        let export = m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "macro_export");
 
         // FIXME: cfg_attr
-        let builtin =
-            m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "rustc_builtin_macro");
-
-        let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export, builtin });
+        let export = attrs.by_key("macro_export").exists();
+        let local_inner =
+            attrs.by_key("macro_export").tt_values().map(|it| &it.token_trees).flatten().any(
+                |it| match it {
+                    tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
+                        ident.text.contains("local_inner_macros")
+                    }
+                    _ => false,
+                },
+            );
+        let builtin = attrs.by_key("rustc_builtin_macro").exists();
+
+        let m = self.raw_items.macros.alloc(MacroData {
+            ast_id,
+            path,
+            name,
+            export,
+            local_inner,
+            builtin,
+        });
         self.push_item(current_module, attrs, RawItemKind::Macro(m));
     }
 
diff --git a/crates/ra_hir_def/src/path/lower.rs b/crates/ra_hir_def/src/path/lower.rs
index 9ec2e0dcd..e632f1afb 100644
--- a/crates/ra_hir_def/src/path/lower.rs
+++ b/crates/ra_hir_def/src/path/lower.rs
@@ -9,7 +9,10 @@ use hir_expand::{
     hygiene::Hygiene,
     name::{name, AsName},
 };
-use ra_syntax::ast::{self, AstNode, TypeAscriptionOwner, TypeBoundsOwner};
+use ra_syntax::{
+    ast::{self, AstNode, TypeAscriptionOwner, TypeBoundsOwner},
+    T,
+};
 
 use super::AssociatedTypeBinding;
 use crate::{
@@ -113,6 +116,20 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
     }
     segments.reverse();
     generic_args.reverse();
+
+    // handle local_inner_macros :
+    // Basically, even in rustc it is quite hacky:
+    // https://github.com/rust-lang/rust/blob/614f273e9388ddd7804d5cbc80b8865068a3744e/src/librustc_resolve/macros.rs#L456
+    // We follow what it did anyway :)
+    if segments.len() == 1 && kind == PathKind::Plain {
+        let next = path.syntax().last_token().and_then(|it| it.next_token());
+        if next.map_or(false, |it| it.kind() == T![!]) {
+            if let Some(crate_id) = hygiene.local_inner_macros() {
+                kind = PathKind::DollarCrate(crate_id);
+            }
+        }
+    }
+
     let mod_path = ModPath { kind, segments };
     return Some(Path { type_anchor, mod_path, generic_args });