[R-SIG-Mac] Makeconf and GCC version: Leopard vs Snow Leopard

[Simon Urbanek]

On Mar 17, 2010, at 9:38 AM, Simon Anders wrote:

> Hi Simon etc.
> 
> We've recently got a number of question from users of our packages, who, for certain reasons, wanted to compile them from source on a Mac, and ran into problems, namely the error message that 'gcc-4.2' was not found. I don't know if the issue has already been discussed but as I've just investigated it,

It is worth checking the archives - it would give you the correct answer. It is simply about outdated Xcode. We require Xcode 3.1 or higher for Leopard builds -- see
http://r.research.att.com/tools/ 
mainly because of issues in older Xcodes. The latest Xcode for 10.5 is Xcode 3.1.4 and is at the top of the Xcode download list in ADC (=easy to find). Admittedly, the Tiger build requirement  (Xcode 2.4.0+)is in the FAQ, Leopard (Xcode 3.1+) is not -- I'll fix that.

Thanks,
Simon




> I would like to share my findings. (Note that I'm not a Mac user myself, so I am not too experienced with this.)
> 
> It seems that the current version of Xcode (3.2.1) has the GNU Compiler Collection (GCC) in the version 4.2. Most users of Leopard have, however, the old Xcode 3.0 installed, which ships with GCC 4.0. (The Xcode 3.2.1 package presented on the Apple web site only works for Snow Leopard. There is an XCode 3.2.x for Leopard as well somewhere on the web site, but it is quite difficult to find.)
> 
> I've just looked over the shoulder of a Mac user who had installed the pre-compiled binary from CRAN for R-2.11.0 (devel) on his Leopard machine with Xcode 3.0 installed. When he tried to run 'R CMD INSTALL' on a source package, he got the aformentioned error that 'gcc-4.2' was missing.
> 
> The reason that R was explicitly looking for 'gcc-4.2' was that this is what the 'CC' variable was se to in Makeconf (to be precise: in /Library/Framework/R.framework/Resources/i386/Makeconf )
> 
> We changed, in the Makeconf file, 'gcc-4.2' to 'gcc' in the definition of 'CC', and likewise for 'g++-4.2' and 'gfortran-4.2' in the respective lines. (Note that all Xcode versions seem to install a symlink from the installed binary 'gcc-4.x' to 'gcc' and likewise for g++ and gfortran.) Furthermore, it was necessary to remove the compiler flag '-mtune=core2' from CC_FLAGS, CXX_FLAGS and FC_FLAGS, as this tuning target was not yet available in GCC 4.0.
> 
> With this, building source packages worked fine.
> 
> Conclusion: The precompiled R binary for Mac would be "more compatible", namely working with the typical configuration of both Leopard and Snow Leopard if the Makeconf did not specify the exact GCC version and did not use the 'core2' tuning flag.
> 
> Could we change this, please?
> 
> Cheers
>  Simon
> 
> 
> 
> +---
> | Dr. Simon Anders, Dipl.-Phys.
> | European Molecular Biology Laboratory (EMBL), Heidelberg
> | office phone +49-6221-387-8632
> | preferred (permanent) e-mail: sanders at fs.tum.de
> 
>