R-devel on FreeBSD: Support for C99 complex type is required

I think this is really a FreeBSD support question. In 2011, an OS really
should have support for a 1999 standard. Darwin, a FreeBSD derivative,
does and its help page says

Hmm, on FreeBSD I really have no other piece of software which complains
about lack of C99.

FreeBSD is planning on switching to a different compiler, llvm/clang,
and so the version of gcc is stale, but still it should be more than
sufficient to support C99.  FreeBSD started a C99 effort a decade ago
and I haven't heard from this initiative in a long time as I thought
it was completed.

    http://www.freebsd.org/projects/c99/index.html

There is I believe experimental support for llvm/clang built into
FreeBSD 9, so you could try compiling with that instead of gcc.

Ok, I understand. This seems consistent. I will try to contact FreeBSD
support about it. Please do not change back the behaviour for FreeBSD
(towards emulation code) until this is clarified.

Yes, please mail freebsd-standards at google.com

I haven't looked at what autoconf is testing exactly but I suspect
simply another argument must be provided in the autoconf script to get
it to pull up the C99 math functions its looking for.

          - Murray