From 69b023f93bf77c6b25099a45392f7b293a4d3dde Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Thu, 13 Apr 2023 11:38:40 +0200
Subject: [PATCH] compiletest: complain about unknown flags

---
 src/tools/miri/tests/compiletest.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tools/miri/tests/compiletest.rs b/src/tools/miri/tests/compiletest.rs
index 21eaeabe6ad..355f6f95310 100644
--- a/src/tools/miri/tests/compiletest.rs
+++ b/src/tools/miri/tests/compiletest.rs
@@ -100,12 +100,24 @@ fn run_tests(mode: Mode, path: &str, target: &str, with_dependencies: bool) -> R
     };
 
     // Handle command-line arguments.
+    let mut after_dashdash = false;
     config.path_filter.extend(std::env::args().skip(1).filter(|arg| {
+        if after_dashdash {
+            // Just propagate everything.
+            return true;
+        }
         match &**arg {
             "--quiet" => {
                 config.quiet = true;
                 false
             }
+            "--" => {
+                after_dashdash = true;
+                false
+            }
+            s if s.starts_with('-') => {
+                panic!("unknown compiletest flag `{s}`");
+            }
             _ => true,
         }
     }));