best way to tune ports to add a CLFAGS entry

[Julian Elischer]

On 29/06/2016 12:01 PM, Chris H wrote:
> On Wed, 29 Jun 2016 00:52:51 +0800 Julian Elischer <julian at freebsd.org> wrote
>
>> At work I am doing various cross compiles in order to make a product
>> under freebsd that actually will run under a modified FreeBSD that
>> runs on an appliance. We want to get away from hand rolling everything
>> to leverage all teh work in getting ports working well on FreeBSD.
>>
>> We have some extra syscalls and some structures have different sizes,
>> so we need to compile/link agains an alternate set of
>> includes/libraries and not those in /usr/include or /usr/lib.
>>
>> Ideally I want to use the "--sysroot" and "-isystem" options to the
>> compiler/linker or failing that, add a -I or -L entries to make it
>> look at the correct includes and libraries, not those in the base system.
>>
>>
>> In many ports CFLAGS etc. are sent in via the arguments to ./configure
>> or environment vars, but there are many other ports that have other
>> ways to specify these.
>>
>> Does the ports framework have any standard way to do this?
>> LDEXTRA_ARGS or EXTRA_CFLAGS or similar?
>>
>> I've looked around and can't really see anything.  Best would be a
>> single file to which I could add these things but adding them to the
>> environment would also work.
>>
>> yours in ports ignorance..
>>
> Hi Julian.
> While I can't answer your question directly.
> Maybe a USES=FAKE_INCLUDE, USES=FAKE_LIB?
> No. I haven't implemented it. Just throwing it out there, while
> it occurs to me. If someone doesn't beat me to it. I'd like
> to look into the feasibility of something like this, to
> accommodate something along the lines of what you're asking about.
> I often shy away from tasks I'd like to undertake, because it seems
> like too much work to cobble up just the right environment to
> accomplish it. But if I could make a universal convenience knob
> like I mention above. It'd be perfect. Tho I haven't thought it
> completely through. I like the sound of it. :-)
>
> Apologies, for stepping on your thread. Hope you don't mind.

USES_SYSROOT=/foo/bar
would be the way to describe it

feedable from the environment, and interpretted by each package as it 
suits it.
(or taken from /etc/ports.conf) .
Is there a file like that? seems that /etc/make.conf is still 
controlling it.

>> Julian
>>
>>
> --Chris
>
>
>