Re: [gpsd-dev] C99 Aftermath

[Gary E. Miller]

Yo Fred!

On Mon, 5 Sep 2016 18:04:13 -0700 (PDT)
Fred Wright <address@hidden> wrote:

> On Mon, 5 Sep 2016, Gary E. Miller wrote:
> > On Mon, 5 Sep 2016 16:47:45 -0700 (PDT)
> > Fred Wright <address@hidden> wrote:
> >  
> [...]
> > What I would like is the C99 stuff be guarded by #ifdef __linux__.
> > Then at least the Linux code can be clean.  
> 
> In this context, "clean" means "compatible with some hypothetical
> future compiler that demands C99 compliance with no alternative".

Not to mean, clean maens that hypothetical future patches break C99
and POSIX 2001 compliance by accident.

> While such compliance is a useful goal, it's not a terribly pressing
> one so far, and certainly not one that should take precedence over
> keeping the code working or fixing real bugs.

I see not conflict.  The fix is easy.  Just ifdef the C99 and POSIX
instructions, and/or tweak SConstuct.

> The problem with overuse of "#ifdef __linux__" is that it makes
> Linux-based testing less applicable to non-Linux behavior, and thus
> makes it easier for bugs to creep in for non-Linux platforms when most
> developers are testing on Linux.  Keeping the code as "naturally
> portable" as possible maximizes the effectiveness of testing.

Can't say I agree.  Since Linux seems to be the sanest C99 and
POSIX 2001 platform it is the best starting place.

If is only because FreeBSD is so standards non-compliant that we must not
enforce commpliance for that turkey.  

I tried ifdef'ing out all the broken OS, but in the end just including Linux
does exactly the same thing and is a lot easier.

> To the extent that stuff *does* have to be platform specific, there's
> also the question of how much of that logic should be in the code
> itself, vs. how much should be handled in the "configure" setup.

Yes, always debateable.  And I really don't care where it goes.  If you
ahve a preference, have at it, otherwise I'll do it to my taste.

> > As noted above, I'd like the C99 enforced for Linux.  That will
> > keep a lot of junk from creeping back in.  Can you do the #ifdef
> > wrap and resubmit?  
> 
> Even if one were to take that approach, there's a nontrivial amount of
> work in determining the *right* thing to do in the Linux case,

Yes, there was, but since it is now done, let us not throw away that work.

> Note also that one can test for C99 compliance at any time purely by
> the command-line scons invocation, without making any code changes at
> all.

We are trying to save the programmer work, not leave work for him to do.


> In theory, one could simply say "CC=c99 scons ..." in many
> cases,

Sadly, only one, Linux.  So just hard code it.

> Even fixing the warnings that appear *without* C99 should probably be
> higher priority than C99 compliance.

I have none in Linux.  If you have some in your OS then please feel free
to make that your priority.

> OK, I'll send the patches.  Beware of incoming mailbomb. :-)

I took a quick look,  Not a long enough look to apply them yet, and
since we are still debating the first one I'll not do it yet.

I think the patches might be in the wrong order.  You seem to be reverting
fixes before fixing the issue.  Which will might break git-bisect.  Are
you sure you order is correct?

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

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