Optimization level and event handlers in SunView 1

[Martin Boyer]

The SunOS 4.0.3 man page for cc(1) says:

"Neither -O3 nor -O4 should be used when compiling either device drivers,
or programs that modify external variables from within signal handlers."

Do event handlers, such as those set by the WIN_EVENT_PROC window
attribute, qualify as signal handlers?  I suppose that deep down in
window_main_loop() (in notify_dispatch(), probably), there is a call to
select() checking for activity on the window descriptors.  It is quite
possible that no signal handler is required to do that.

SIGWINCH-related events, however, are another matter; the handlers for
CANVAS_REPAINT_PROC and CANVAS_RESIZE_PROC *might* be called from within a
signal handler *or* might set an external variable that the notifier loop
detects to issue the relevant events (WIN_REPAINT and WIN_RESIZE).

Accordingly, can the O3 and O4 optimization levels be used on programs
linked with the SunView library?

Thanks,

Martin Boyer                            mboyer at ireq-robot.hydro.qc.ca
Institut de recherche d'Hydro-Quebec    mboyer at ireq-robot.uucp
Varennes, QC, Canada   J3X 1S1
+1 514 652-8136