[Rd] Updated Windows toolchain

[Prof Brian Ripley]

CRAN Windows binary packages built for R-devel are now online, and Uwe's 
winbuilder has gained the ability to check source packages under R-devel.

Windows check results are available from
http://cran.r-project.org/bin/windows/contrib/checkSummaryWin.html
and in due course from the main CRAN check page.

There have been a few updates to the toolchain:

(i) It is now based on a beta of gcc 4.6.3, and so reports almost the 
same compilation warnings/errors as the CRAN check machines.

(ii) There are various bug-fixes to the toolchain: notably x^n and 
exp(x) use gradual underflow to denormal numbers rather than abrubtly 
underflowing to zero.

(iii) This is a 'multilib' toolchain: the compiler is named 'gcc.exe' 
for both architectures, selected by flag -m32 (the default) and -m64.

On 29/11/2011 07:56, Prof Brian Ripley wrote:
> An updated toolchain is now being used for Windows' builds of R-devel:
> details are in the R-admin manual and at
> http://www.murdoch-sutherland.com/Rtools/ and
> http://www.stats.ox.ac.uk/pub/Rtools/
>
> Both 32- and 64-bit parts of the toolchain use v2.0.1 of the Mingw-w64
> project's runtime and a beta of gcc 4.5.4: the Mingw.org project's
> builds are no longer used. This should mean that code which compiles for
> 64-bit Windows also compiles for 32-bit Windows, and v.v. unless code
> makes (incorrect but common) assumptions that pointers fit into longs.
>
> A very few packages will need modifications because they contain
> declarations which clash with the headers in this toolchain: where we
> are aware of problems the maintainers have been informed.
>
> At DLL level different Windows' toolchains should be compatible: at C
> level they mostly are but at C++ level they are pretty much incompatible
> (so that for example GDAL has to be re-compiled for every toolchain: and
> Rcpp users need to be careful to use only one toolchain for Rcpp and
> their packages). All the external software previously made available
> (and more) is made available at http://www.stats.ox.ac.uk/pub/Rtools .
>
> The toolchain has support for OpenMP and pthreads: however OpenMP
> support is not enabled by default in R (it is too slow to be much use).
> If you do make use of it in your packages, be aware that you will need
> to ship the appropriate pthreads DLL(s).
>
> It is expected that there will be several further minor updates prior to
> the release of 2.15.0 in ca 4 months, but this step is the major one.
>


-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595