3.1 Before You Start
Building R packages requires a toolchain that must be in place before you begin developing. If you are developing packages that contain only R code, then the tools you need come with R and RStudio. However, if you want to build packages with compiled C, C++, or Fortran code (or which to build other people’s packages with such code), then you will need to install additional tools. Which tools you install depends on what platform you are running.
3.1.1 Mac OS
For developing in Mac OS, you will first need to download the Xcode development environment. While you do not need the IDE that comes with Xcode to develop R packages you need many of the tools that come with it, including the C compiler (
clang). Xcode can be obtained from either the Mac App Store or from Apple’s Xcode developer’s page. Once this is installed you will have the C compiler as well as a number of additional Unix shell tools. You will also have necessary header files for compiling C code.
While it’s unlikely that you will be building your own packages with Fortran code, many older packages (including R itself) contain Fortran code. Therefore, in order to build these packages, you need a Fortran compiler. Mac OS does not come with one by default and so you can download the GNU Fortran Compiler from the R for Mac tools page.
There are more details provided on the R for Mac tools package maintained by Simon Urbanek, particularly for older versions of Mac OS.
On Windows, the R Core has put together a package of tools that you can download all at once and install via a simple installer tool. The Rtools package comes in different versions, depending on the version of R that you are using. Make sure to get the version of Rtools that matches your version of R. Once you have installed this, you will have most of the tools needed to build R packages. You can optionally install a few other tools, documented here.
If you are using R on a Unix-like system then you may have already have the tools for building R packages. In particular, if you built R from the sources, then you already have a C compiler and Fortran compiler. If, however, you installed R from a package management system, then you may need to install the compilers, as well as the header files. These usually coming in packages with the suffix
-devel. For example, the header files for the
readline package may come in the package
readline-devel. The catch is that these
-devel packages are not needed to run R, only to build R packages from the sources.