gdb: add assert in remote_target::wait relating to async being off
While working on another patch I ended up in a situation where I had
async mode disabled (with 'maint set target-async off'), but the async
event token got marked anyway.
In this situation GDB was continually calling into
remote_target::wait, however, the async token would never become
unmarked as the unmarking is guarded by target_is_async_p.
We could just unconditionally unmark the token, but that would feel
like just ignoring a bug, so, instead, lets assert that if
!target_is_async_p, then the async token should not be marked.
This assertion would have caught my earlier mistake.
There should be no user visible changes with this commit.
diff --git a/gdb/remote.c b/gdb/remote.c
index f0f3dcb..1bb6138 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8348,9 +8348,13 @@ remote_target::wait (ptid_t ptid, struct target_waitstatus *status,
remote_state *rs = get_remote_state ();
/* Start by clearing the flag that asks for our wait method to be called,
- we'll mark it again at the end if needed. */
+ we'll mark it again at the end if needed. If the target is not in
+ async mode then the async token should not be marked. */
if (target_is_async_p ())
clear_async_event_handler (rs->remote_async_inferior_event_token);
+ else
+ gdb_assert (!async_event_handler_marked
+ (rs->remote_async_inferior_event_token));
ptid_t event_ptid;
