How to let YouCompleteMe handle c99 project?
Create a .ycm_extra_conf.py file vim ~/.vim/.ycm_extra_conf.py def Settings( **kwargs ): return { 'flags': [ '-std=gnu99', #'-std=c99', '-x', 'c', #'-std=cpp11', #'-x', 'c++', '-static', '-no-pie', #'-D_POSIX_SOURCE', ], } Add one line in ~/.vimrc vim ~/.vimrc let g:ycm_global_ycm_extra_conf = '~/.vim/.ycm_extra_conf.py'