Summary: This is useful when using clangd with CMake based projects in Visual Studio Code since when using CMake the `compile_commands.json` file is usually located in a `build` subdirectory which isn't a parent directory of the source files. Allowing passing relative paths to -compile-commands-dir allows specifying `clangd.arguments = ["-compile-commands-dir=build"]` in VSCode's settings file and having it work for each CMake based project that uses the `build` subdirectory as the build directory (instead of having to specify the absolute path to the compile commands directory for each separate project in VSCode's settings).
Patch by Daan De Meyer!
Reviewers: sammccall
Reviewed By: sammccall
Subscribers: ilya-biryukov, ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D53481
llvm-svn: 345022