compiler selection

[Ryan Schmidt]

On Sep 28, 2007, at 09:55, Michael Wild wrote:

> I wonder what the policy/methodology is concerning compiler  
> selection. I perused the MacPorts guide but couldn't find anything.  
> Am I right in the assumption that MacPorts automatically comes with  
> its own gcc compiler suite and requires it to be present (I think I  
> read something like that somewhere in the FAQ)? If so, on which one  
> can I rely to be there? gcc32, gcc40/1/2 or apple-gcc40? just  
> because the executable have all different names...

No. MacPorts does not require any MacPorts-built gcc to be there.  
Most ports don't need that. MacPorts itself, and most ports, use the  
Apple's system gcc, which is 3.3 on Mac OS X 10.3.9 and 4.0 on 10.4.10.

> My problem actually is that a port which I'm preparing requires  
> gfortran which doesn't come with Apple's system gcc but is in  
> port:gcc42. I could simply do "configure.fc ${prefix}/bin/gfortran- 
> mp-4.2, but what if someone has another gcc installed? I could  
> depends_build on gcc42 but if a gcc suite is required by MacPorts  
> anyways I wouldn't like to impose something which might install  
> another compiler suite unnecessarily.

If you require gfortran, you should depends_build on gcc42. Nevermind  
anyone who has gcc43 installed; that's beta and shouldn't be relied  
on until gcc44 is released, at which point the port can be updated.  
Nevermind anyone who has gcc41 or gc40 or earlier installed; any  
ports that still depend on those should be updated to gcc42.

> So, currently I do a hacky
>
> set gfortran [lindex [lsort -decreasing [glob \
>     -type f "${prefix}/bin/gfortran*"]] 0]
> configure.fc ${gfortran}
>
> and hope to get the compiler with the highest version number. For  
> my installation this works, but I'm quite unhappy with it.
>
> Does anyone know a better solution to that problem?

Yeah, that's hacky. Just depend on gcc42.

Some ports have variants for selecting a compiler. See pdftk. But  
it's only because gcc takes so long to build, especially on PowerPCs.  
Everyone who has ports that depend on non-Apple gcc, though, should  
strive to update them to gcc42 so that nobody needs the old versions  
installed anymore.