Note ccache

ccache is a tool which provides a cache for C/C++/Objective-C compiler operations. We've found that it makes LLVM recompilation a bit easier to handle, and not everyone knows about it yet!

On Ubuntu, for example, you can use it without modifying any build scripts by simply installing the ccache package and putting links to it in your path like so:

apt-get install ccache
ln -s /usr/bin/ccache /usr/local/bin/gcc
ln -s /usr/bin/ccache /usr/local/bin/g++
ln -s /usr/bin/ccache /usr/local/bin/cc

Then you can verify that ccache is being used during builds:

ccache --show-stats