Merge #3836

3836: Macro patterns are not confused with expressions. r=matklad a=matklad

We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).

We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.



bors r+
🤖

Co-authored-by: Aleksey Kladov <[email protected]>

1 files changed, 29 insertions, 2 deletions

diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index eb97288f1..ff4599b71 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -1,8 +1,10 @@
-use super::{infer, type_at, type_at_pos};
-use crate::test_db::TestDB;
 use insta::assert_snapshot;
 use ra_db::fixture::WithFixture;
 
+use super::{infer, type_at, type_at_pos};
+
+use crate::test_db::TestDB;
+
 #[test]
 fn cfg_impl_def() {
     let (db, pos) = TestDB::with_position(
@@ -658,3 +660,28 @@ fn test() {
     );
     assert_eq!("S", type_at_pos(&db, pos));
 }
+
+#[test]
+fn macro_in_arm() {
+    assert_snapshot!(
+        infer(r#"
+macro_rules! unit {
+    () => { () };
+}
+
+fn main() {
+    let x = match () {
+        unit!() => 92u32,
+    };
+}
+"#),
+        @r###"
+    [52; 111) '{     ...  }; }': ()
+    [62; 63) 'x': u32
+    [66; 108) 'match ...     }': u32
+    [72; 74) '()': ()
+    [85; 92) 'unit!()': ()
+    [96; 101) '92u32': u32
+    "###
+    );
+}