From 041212f8fbb9f52d41167448e4fbc2ce8cc7ee9a Mon Sep 17 00:00:00 2001
From: Fabian Wolff <fabian.wolff@alumni.ethz.ch>
Date: Sat, 2 Oct 2021 19:15:45 +0200
Subject: Report fatal lexer errors in `--cfg` command line arguments

---
 compiler/rustc_interface/src/interface.rs | 5 ++++-
 1 file changed, 4 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 8393826aa12..3233887169c 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -81,7 +81,10 @@ pub fn parse_cfgspecs(cfgspecs: Vec<String>) -> FxHashSet<(String, Option<String
         let cfg = cfgspecs
             .into_iter()
             .map(|s| {
-                let sess = ParseSess::with_silent_emitter();
+                let sess = ParseSess::with_silent_emitter(Some(format!(
+                    "this error occurred on the command line: `--cfg={}`",
+                    s
+                )));
                 let filename = FileName::cfg_spec_source_code(&s);
                 let mut parser = new_parser_from_source_str(&sess, filename, s.to_string());
 
-- 
cgit 1.4.1-3-g733a5