From 41b69aae912aa9a1a8d5ed9518e73d136b42e7ca Mon Sep 17 00:00:00 2001
From: Urgau <urgau@numericable.fr>
Date: Sat, 13 Jan 2024 12:18:51 +0100
Subject: Add way to express no-values with check-cfg

---
 compiler/rustc_interface/src/interface.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'compiler/rustc_interface/src/interface.rs')

diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 32fba6ade88..5ca88090996 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -218,7 +218,9 @@ pub(crate) fn parse_check_cfg(dcx: &DiagCtxt, specs: Vec<String>) -> CheckCfg {
             }
         }
 
-        if values.is_empty() && !values_any_specified && !any_specified {
+        if !values_specified && !any_specified {
+            // `cfg(name)` is equivalent to `cfg(name, values(none()))` so add
+            // an implicit `none()`
             values.insert(None);
         } else if !values.is_empty() && values_any_specified {
             error!(
-- 
cgit 1.4.1-3-g733a5