vim lsc

Install vim-lsc according to the instructions in its README.

Configure ccls as the language server (example for cpp, do similarly for other filetypes, as needed):

let g:lsc_server_commands = {
\ 'cpp': {
\    'command': 'ccls',
\    'message_hooks': {
\        'initialize': {
\            'initializationOptions': {'cache': {'directory': '/tmp/ccls/cache'}},
\            'rootUri': {m, p -> lsc#uri#documentUri(fnamemodify(findfile('compile_commands.json', expand('%:p') . ';'), ':p:h'))}
\        },
\    },
\  },
\}

If the compilation database is correctly set, then things should work (e.g. reference highlight of the symbol under the cursor should be visible). See |lsc-commands| for the list of all available commands.

Default mappings are provided out-of-the-box (see |lsc-default-map|). To set custom mappings, change the values in |g:lsc_auto_map|, e.g.:

let g:lsc_auto_map = {
\  'GoToDefinition': '<M-d>',
\  'FindReferences': '<M-r>',
\}

(optionally add 'defaults': v:true to keep default values for other mappings that are not redefined).