Merge #2628

2628: Add macro 2.0 support in parser r=matklad a=edwin0cheng

This PR added a new syntax kind : `MACRO_DEF` and a keyword `MACRO_KW`

there are two syntax for declarative macro 2.0 :
1. Normal : `macro m { ($i:ident) => {} }` , which handle similar to legacy one. 
2. Call like: `macro m($i:ident) {}`, it produces a single token tree which have two child token trees : `($i:ident)` and `{}`

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

1 files changed, 15 insertions, 0 deletions

diff --git a/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.rs b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.rs
new file mode 100644
index 000000000..781047ba1
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.rs
@@ -0,0 +1,15 @@
+macro parse_use_trees($($s:expr),* $(,)*) {
+    vec![
+        $(parse_use_tree($s),)*
+    ]
+}
+
+#[test]
+fn test_use_tree_merge() {
+    macro test_merge([$($input:expr),* $(,)*], [$($output:expr),* $(,)*]) {
+        assert_eq!(
+            merge_use_trees(parse_use_trees!($($input,)*)),
+            parse_use_trees!($($output,)*),
+        );
+    }
+}