diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 491ad31..3a3096f 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -1258,7 +1258,9 @@
     return;
   }
 
-  // Parse optional class method name.
+  // Parse class method name.  It's non-optional in the sense that a trailing
+  // comma is required, but it can be the empty string, and then we record a
+  // nullptr.
   IdentifierLoc *ClassMethod = nullptr;
   if (Tok.is(tok::identifier)) {
     ClassMethod = ParseIdentifierLoc();
@@ -1277,7 +1279,8 @@
     return;
   }
   
-  // Parse optional instance method name.
+  // Parse instance method name.  Also non-optional but empty string is
+  // permitted.
   IdentifierLoc *InstanceMethod = nullptr;
   if (Tok.is(tok::identifier))
     InstanceMethod = ParseIdentifierLoc();