Understanding CMake integration for out-of-tree projects
Implementing your features in an in-tree project is good for prototyping, since most of the infrastructure is already there. However, there are many scenarios where pulling the entire LLVM source tree into your code base is not the best idea, compared to creating an out-of-tree project and linking it against the LLVM libraries. For example, you only want to create a small code refactoring tool using LLVM's features and open source it on GitHub, so telling developers on GitHub to download a multi-gigabyte LLVM source tree along with your little tool might not be a pleasant experience.
There are at least two ways to configure out-of-tree projects to link against LLVM:
- Using the
llvm-configtool - Using LLVM's CMake modules
Both approaches help you sort out all the details, including header files and library paths. However, the latter creates more concise and readable CMake scripts, which is preferable...
