[Rd] Using Rtools with gcc 4.8.3

[Jeroen Ooms]

I started working on some R bindings for mongo-c-driver [1]. The C
library compiles fine on Ubuntu Trusty (gcc 4.8.2) and osx (clang),
however on my windows machine (gcc 4.6.3 from Rtools 3.1) it fails
with:  'INIT_ONCE_STATIC_INIT' undeclared. Google suggests that this
might be a problem in older versions of mingw-w64. So I grabbed a copy
of mingw-w64 version 4.8.3 and indeed, here the library compiles
without errors.

Now I am unsure how to make mingw 4.8.3 work with Rtools. I extracted
the contents of [2] into "C:\RBuildTools\3.1\gcc-4.8.3\" and my
package Makevars contains

  CC = "c:/RBuildTools/3.1/gcc-4.8.3/bin/gcc"

However it seems like R still uses the old gcc 4.6.3 for R CMD
INSTALL. What am I doing wrong? Is there a recommended setup for
building packages on Windows using a Rtools but with another compiler?

In addition: will I be able to publish this package to CRAN, or do I
have to wait for Rtools to get updated with a more recent gcc?


[1] https://github.com/mongodb/mongo-c-driver
[2] http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/mingw-builds/4.8.3/threads-posix/dwarf/