[R-SIG-Mac] building 32-bit version of R 3.x

[Alexy Khrabrov]

Simon -- thanks, the flags were the issue.  I think the r_arch was not
enough, and Fortran flags had to be supplied separately in addition to
C++ ones.

About HTML and other assumptions, I just think it's good to reexamine
them form time to time and see where the online tech stands...

Obviously I'm not going to link incompatible architectures, so I guess
the management consists of shell and linker paths, etc.  Was wondering
about any other caveats of having both.  I've installed into a
separate prefix for now; how did you manage R32 and R64 before under
R.framework?  E.g. can R32 be installed under R.framework/Versions as
a separate 32-bit version?  I guess not as it's 3.0 too, but am
generally curious about aspects of these two now coexisting.

A+

On Mon, Mar 3, 2014 at 11:01 AM, Simon Urbanek
<simon.urbanek at r-project.org> wrote:
>
> On Mar 3, 2014, at 12:25 AM, Alexy Khrabrov <deliverable at gmail.com> wrote:
>
>> On Tue, Feb 25, 2014 at 3:11 AM, Prof Brian Ripley
>> <ripley at stats.ox.ac.uk> wrote:
>>
>>>> Looking at the sources, there's no obvious way to switch to 32-bit.  The
>>>> gfortran.pkg (4.2.3) seems obsolete; I've configured the default setup
>>>
>>> So?  At least it includes a 32-bit compiler (by default if I understand the
>>> version you are using).
>>>
>>
>> Correct -- but with the current Apple gcc and -arch i386, that old gfortran and C++ disagree on integer and double sizes in configure.
>>
>
> I don't think so - those two the same even between 32-bit and 64-bit. I suspect you're misinterpreting the output (which you didn't provide) and if there is indeed some other error you have likely not set the correct flags. I can confirm that
>
> CC='gcc -arch i386' CXX='g++ -arch i386' F77='gfortran -arch i386' FC='gfortran -arch i386' OBJC='gcc -arch i386'
>
> works just fine (assuming your system has both 32-bit and 64-bit libraries).
>
>
>>> You need to specify a 32-bit compiler.  AFAIK -arch is specific to Apple
>>> front-ends, and the value is i386, not x686.
>>>
>>> If you build multilib GCC from the sources, the flag needed is -m32.
>>>
>>> This *is* all in the relevant manual.
>>
>> The manual seems rather general there.  I'd like to know whether
>> someone has done this recently and what the exact steps are to
>>
>> -- build the gcc and gfortran with both i386 and x86_64 standard libraries
>> -- compile latest R with it
>> -- how to install and manage the setup for invoking one or the other,
>> and linking to one's or the other's .dylib
>>
>
> You cannot link one another's dylibs since they are two entirely different, incompatible architectures.
>
> Building R with the default compilers (Apple + gfortran from CRAN) works out of the box for both in 32-bit and 64-bit. For any other setup, you're entirely on your own. If you want a multi-arch installation of R, you can set r_arch=i386 for the 32-bit build and r_arch=x86_64 for the 64-bin build to build separate architectures. The default install will then create a merged universal framework - see instructions for 2.x series of R that used multi-arch install on OS X.
>
>
>>>>        [[alternative HTML version deleted]]
>>
>> I'll dare to object to your signature objection here -- the times
>> moved on, and most web-based email services, such as gmail, use HTML
>> mail by default.  Even those who used to run mutt and the like are on
>> gmail, and not always do they bother to set plain text mode.  So I'd
>> be OK with the line above, but I will set plain text mode to honor the
>> tradition.
>>
>
> As David pointed out you can object all you want, but those are the rules you were asked to abide by. Whether you like them or not is relevant - HTML cause unnecessary problems in e-mails. Unfortunately, bad defaults are ubiquitous (just look at Outlook to see how you can end up with e-mails that have content that doesn't communicate anything - not even the intended message).
>
> Cheers,
> Simon
>
>