[Bioc-devel] compiling C code in distributed packages

Hi,

I'm new in using C code into R packages, so I apologize if my question
looks silly.
I'm testing a library containing C code. It works fine on the Linux
system where I created it, and I can easily install and use it into a
Windows system that has been set up to build packages. Rather, when I
try to install it into a Mac, I get an error message presumably  since
the system is lacking C/C++ compilers:

* Installing *source* package 'foo' ...
** libs
** arch - i386
/Library/Frameworks/R.framework/Resources/bin/SHLIB: line 1: make:
command not found
chmod: /Library/Frameworks/R.framework/Versions/2.7/Resources/library/foo/libs/i386/*:
No such file or directory
** arch - ppc
/Library/Frameworks/R.framework/Resources/bin/SHLIB: line 1: make:
command not found
chmod: /Library/Frameworks/R.framework/Versions/2.7/Resources/library/foo/libs/ppc/*:
No such file or directory
ERROR: compilation failed for package 'foo'
** Removing '/Library/Frameworks/R.framework/Versions/2.7/Resources/library/foo'
** Restoring previous
'/Library/Frameworks/R.framework/Versions/2.7/Resources/library/foo'
.

Does this mean that additional software is always required to use R
libraries with embedded C code ? (the Xcode that would be necessary in
Mac is 1Gb..)
This sounds weird to me since I know that many libraries use C code
and I already installed them on many computers without having the
requirement of installing developmental software.

Are the packages with C code released from R or Bioconductor different
from the one that I'm building by my self?

Thanks for you help,

mattia