From 04a14677e423f9a93ae8f795e2c34b4abf9c8eee Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev@sunfishcode.online>
Date: Sun, 3 Oct 2021 10:24:20 -0700
Subject: [PATCH] Issue a friendlier error message if fde-registry is enabled
 with no lock impl.

---
 src/unwinder/find_fde/registry.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/unwinder/find_fde/registry.rs b/src/unwinder/find_fde/registry.rs
index 0f2502c..5341a35 100644
--- a/src/unwinder/find_fde/registry.rs
+++ b/src/unwinder/find_fde/registry.rs
@@ -67,6 +67,8 @@ unsafe fn lock_global_state() -> impl ops::DerefMut<Target = GlobalState> {
         });
         MUTEX.lock()
     }
+    #[cfg(not(any(feature = "libc", feature = "spin")))]
+    compile_error!("Either feature \"libc\" or \"spin\" must be enabled to use \"fde-registry\".");
 }
 
 pub fn get_finder() -> &'static Registry {