Re: [PULL v2 00/22] Build system + misc changes for 2020-10-16

[Paolo Bonzini <pbonzini@redhat.com>]

On 17/10/20 21:48, Peter Maydell wrote:
>> 1) are you going to pull v3 and I can fix up everything later?  Or would
>> you prefer me to send v4 once the new curses test is reviewed?
> 
> If the only issue with v3 is that stray warning message I'm
> OK with applying it and improving the test later.

Yes.

>> 2) would you prefer the "library was found but headers weren't" to warn,
>> issue an informative message, or be completely silent?
> 
> I think the build system should just say whether it found a
> working curses setup or not, and do our usual "this is fatal
> if --enable-whatever, otherwise just disable feature". If we
> happen to have convenient information to put in whatever
> the new build system's equivalent of config.log is [ie the
> saved-for-debug-purposes log], we might as well put it in,
> but we don't need to put that in the stdout. (We shouldn't
> say "ncurses found: YES" unless we actually found a working
> version, ideally.)

Ok, I think we can at least use cc.find_library(has_headers: '...') to
avoid warning for the most basic failure mode, and then use cc.links()
to further refine the check.  If the curses header is present but the
test program fails to link, then we are in the same situation as the
multipath check and warning makes sense.

Paolo