From d89ed3e62b152174c3eb5c96713e9b983b11f7ed Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Thu, 23 Jan 2020 14:11:13 -0600
Subject: [PATCH] unix/unix_mphal: Add compile check for incompatible
 GIL+ASYNC_KBD_INTR.

It is not safe to enable MICROPY_ASYNC_KBD_INTR and MICROPY_PY_THREAD_GIL
at the same time.  This will trigger a compiler error to ensure that it
is not possible to make this mistake.
---
 ports/unix/unix_mphal.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ports/unix/unix_mphal.c b/ports/unix/unix_mphal.c
index 3e14409efb..25d1b022db 100644
--- a/ports/unix/unix_mphal.c
+++ b/ports/unix/unix_mphal.c
@@ -41,6 +41,11 @@
 STATIC void sighandler(int signum) {
     if (signum == SIGINT) {
         #if MICROPY_ASYNC_KBD_INTR
+        #if MICROPY_PY_THREAD_GIL
+        // Since signals can occur at any time, we may not be holding the GIL when
+        // this callback is called, so it is not safe to raise an exception here
+        #error "MICROPY_ASYNC_KBD_INTR and MICROPY_PY_THREAD_GIL are not compatible"
+        #endif
         mp_obj_exception_clear_traceback(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception)));
         sigset_t mask;
         sigemptyset(&mask);