Re: [PATCH v2 8/9] fix py-finish-breakpoint.exp with always-async

[Doug Evans <dje@google.com>]

Tom Tromey writes:
 > With target async enabled, py-finish-breakpoint.exp will trigger an
 > assertion failure.
 > 
 > The failure occurs because execute_command re-enters the event loop in
 > some circumstances, and in this case resets the sync_execution flag.
 > Then later gdb reaches this assertion in normal_stop:
 > 
 >       gdb_assert (sync_execution || !target_can_async_p ());
 > 
 > execute_command has a comment explaining why it dispatches events:
 > 
 >       /* If the interpreter is in sync mode (we're running a user
 > 	 command's list, running command hooks or similars), and we
 > 	 just ran a synchronous command that started the target, wait
 > 	 for that command to end.  */
 > 
 > However, the code did not follow this comment -- it didn't check to
 > see if the command started the target, just whether the target was
 > executing a sync command at this point.
 > 
 > This patch fixes the problem by noting whether the target was
 > executing in sync_execution mode before running the command, and then
 > augmenting the condition to test this as well.
 > 
 > Built and regtested on x86-64 Fedora 18.
 > 
 > 	PR gdb/14135:
 > 	* top.c (execute_command): Only dispatch events if command
 > 	started target.
 > ---
 >  gdb/top.c | 4 +++-
 >  1 file changed, 3 insertions(+), 1 deletion(-)
 > 
 > diff --git a/gdb/top.c b/gdb/top.c
 > index 33a78da..03038b6 100644
 > --- a/gdb/top.c
 > +++ b/gdb/top.c
 > @@ -427,6 +427,8 @@ execute_command (char *p, int from_tty)
 >      {
 >        const char *cmd = p;
 >        char *arg;
 > +      int was_sync = sync_execution;
 > +
 >        line = p;
 >  
 >        /* If trace-commands is set then this will print this command.  */
 > @@ -482,7 +484,7 @@ execute_command (char *p, int from_tty)
 >  	 command's list, running command hooks or similars), and we
 >  	 just ran a synchronous command that started the target, wait
 >  	 for that command to end.  */
 > -      if (!interpreter_async && sync_execution)
 > +      if (!interpreter_async && !was_sync && sync_execution)
 >  	{
 >  	  while (gdb_do_one_event () >= 0)
 >  	    if (!sync_execution)
 > -- 

Looks ok to me.