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

[Rainer Hurling]

Today I tried two build R-devel_2011-02-06.tar.gz from sources on 
FreeBSD 9.0-CURRENT (amd64) with gcc-4.5.2 and I got the following 
messages when configuring:


./configure
[..SNIP..]
checking whether C99 double complex is supported...
checking complex.h usability... yes
checking complex.h presence... yes
checking for complex.h... yes
checking for double complex... yes
checking whether cexp exists and is declared... no
checking whether clog exists and is declared... no
checking whether csqrt exists and is declared... yes
checking whether cpow exists and is declared... no
checking whether ccos exists and is declared... no
checking whether csin exists and is declared... no
checking whether ctan exists and is declared... no
checking whether cacos exists and is declared... no
checking whether casin exists and is declared... no
checking whether catan exists and is declared... no
checking whether ccosh exists and is declared... no
checking whether csinh exists and is declared... no
checking whether ctanh exists and is declared... no
checking whether cacosh exists and is declared... no
checking whether casinh exists and is declared... no
checking whether catanh exists and is declared... no
configure: error: Support for C99 complex type is required.
[..script stops here..]

Until 2.12.1 this works for me. In the NEWS file of 2.13.0 I found in 
the INSTALLATION section:

'A C99 compiler is now required, and more C99 language features will be 
used in the R sources.'

What exactly characterizes a C99 compiler? Does gcc-4.5.2 belongs to 
this? Are the special arguments or knobs to consider? Any other ideas?

Please let me know if more infos are needed.

Thanks in advance for any help,
Rainer Hurling