From 8c85c9936f6bc28b6e8e31bed8f4b1bd95c7e836 Mon Sep 17 00:00:00 2001
From: Takayuki Maeda <takoyaki0316@gmail.com>
Date: Thu, 4 Aug 2022 20:43:35 +0900
Subject: [PATCH] add a comment about what we can parse now

---
 compiler/rustc_parse_format/src/lib.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_parse_format/src/lib.rs b/compiler/rustc_parse_format/src/lib.rs
index c98c8cae3782e..4890fade50faf 100644
--- a/compiler/rustc_parse_format/src/lib.rs
+++ b/compiler/rustc_parse_format/src/lib.rs
@@ -763,6 +763,8 @@ impl<'a> Parser<'a> {
             let byte_pos = self.to_span_index(end);
             let start = InnerOffset(byte_pos.0 + 1);
             let field = self.argument(start);
+            // We can only parse `foo.bar` field access, any deeper nesting,
+            // or another type of expression, like method calls, are not supported
             if !self.consume('}') {
                 return;
             }