Chosing the C and C++ compilers

[Anders F Björklund]

Akim Demaille wrote:

>>> Really, I just wish I had a simple means (= not by having to  
>>> specify it on each port command line) to specify CC and CXX.
>>
>> Why would you want to do that? We have few enough volunteers with  
>> few enough resources as it is; I don't think we can afford to  
>> require port maintainers to allow any compiler to be used with  
>> their ports. It's good that we lock it down to a specific  
>> compiler. Port maintainers can override that if necessary for  
>> their specific ports, but it should not be for users to change.
>
> Well, if I change the compiler, I'm well aware that I'm off tracks,  
> and if something goes wrong, it's on my side.

Most of the configure stuff mentioned falls in the "unsupported"  
category...

a.k.a. MacPorts isn't Gentoo ;-)

>>> Or else, I would prefer that the hard coded values be fully  
>>> qualified (/usr/bin/i686-apple-darwin9-gcc-4.0.1) instead of  
>>> short (/usr/bin/gcc-4.0).
>>
>> But then we would have to find out what that value is, for the  
>> current processor architecture and OS version. And what happens  
>> when we want to build a universal binary?
>
> This is something Anders helped me understand, and as I wrote  
> elsewhere, I think that sticking to /usr/bin/gcc-4.0 is a fine  
> option *provided* that the proper cflags are given to the compiler  
> to clarify the target architecture.  In that case I can use my  
> compile farm efficiently, whatever the combination of architectures.

I think you are right to expect to be able to override cc/cxx (at  
your own risk)

>>> In that case I have nothing special to do to use distcc with  
>>> macports.
>>
>> Since we already have some distcc options in MacPorts we obviously  
>> want it to be easy to use with MacPorts. But I personally have  
>> never used it so I have no input on how best to do so.
>
> Using distcc provides a huge speed-up.  At work I "make -kj20".  It  
> makes a large difference.  And I wish I could use the same amount  
> of cpu to upgrade my laptop.

Using ccache is also good, and the combination of the two can be  
really awesome.

> Really, all it requires is to pass the proper flags to the compiler.
>
> Of course I can change my /usr/bin/gcc-4.0 to make it a wrapper  
> around the original one passing additional flags, but I feel that  
> it is more appropriate to have ports pass more precise flags to the  
> compilers.

Use the commandline workaround for now and something better can be  
done for 1.8...

--anders