Support quitting in modules

The idea is that modules should call env->should_quit from time to
time and return as quickly as possible if it returns true.

* src/emacs-module.c (module_should_quit): New module function.
(initialize_environment): Use it.
(funcall_module): Process potential pending quit.

* src/eval.c (maybe_quit): Add reference to module_should_quit.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/eval.c b/src/eval.c
index 8aa33a11282..ef961046bcf 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1474,7 +1474,10 @@ process_quit_flag (void)
    If quit-flag is set to `kill-emacs' the SIGINT handler has received
    a request to exit Emacs when it is safe to do.
 
-   When not quitting, process any pending signals.  */
+   When not quitting, process any pending signals.
+
+   If you change this function, also adapt module_should_quit in
+   emacs-module.c.  */
 
 void
 maybe_quit (void)