Merge #3591

3591: Support local macro_rules r=matklad a=edwin0cheng

This PR implement local `macro_rules` in function body, by adding following things:

1. While lowering, add a `MacroDefId` in body's `ItemScope` as a textual legacy macro. 
2. Make `Expander::enter_expand` search with given `ItemScope`.
3. Make `Resolver::resolve_path_as_macro` search with `LocalItemScope`.

Fix #2181

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 20 insertions, 0 deletions

diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index 32457bbf7..3b7022ad5 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -363,6 +363,26 @@ fn main() {
 }
 
 #[test]
+fn infer_local_macro() {
+    assert_snapshot!(
+        infer(r#"
+fn main() {
+    macro_rules! foo {
+        () => { 1usize }
+    }
+    let _a  = foo!();
+}
+"#),
+        @r###"
+        ![0; 6) '1usize': usize
+        [11; 90) '{     ...!(); }': ()
+        [17; 66) 'macro_...     }': {unknown}
+        [75; 77) '_a': usize
+    "###
+    );
+}
+
+#[test]
 fn infer_builtin_macros_line() {
     assert_snapshot!(
         infer(r#"