macro_rules: NtLifetime cannot start with an identifier

rust-lang · bors · Apr 5, 2020 · Apr 4, 2020 · Apr 4, 2020 · 106b30e86989cb4f201ef7a1b7fac7150b662b92
commit 106b30e86989cb4f201ef7a1b7fac7150b662b92
diff --git a/src/librustc_expand/mbe/macro_parser.rs b/src/librustc_expand/mbe/macro_parser.rs
@@ -768,7 +768,7 @@ fn may_begin_with(token: &Token, name: Name) -> bool {
     /// Checks whether the non-terminal may contain a single (non-keyword) identifier.
     fn may_be_ident(nt: &token::Nonterminal) -> bool {
         match *nt {
-            token::NtItem(_) | token::NtBlock(_) | token::NtVis(_) => false,
+            token::NtItem(_) | token::NtBlock(_) | token::NtVis(_) | token::NtLifetime(_) => false,
             _ => true,
         }
     }

diff --git a/src/test/ui/macros/issue-70446.rs b/src/test/ui/macros/issue-70446.rs
@@ -0,0 +1,13 @@
+// check-pass
+
+macro_rules! foo {
+    ($(: $p:path)? $(: $l:lifetime)? ) => { bar! {$(: $p)? $(: $l)? } };
+}
+
+macro_rules! bar {
+    ($(: $p:path)? $(: $l:lifetime)? ) => {};
+}
+
+foo! {: 'a }
+
+fn main() {}