vim-lsp-cxx-highlight issue demonstration

init.vim

" Bootstrap vim-plug automatically, if not already present
let s:vim_plug_autoload_file = '~/.config/nvim/autoload/plug.vim'
if empty(glob(s:vim_plug_autoload_file))
  execute "!curl -fLo " . s:vim_plug_autoload_file . " --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim"
endif

set encoding=utf8
set ffs=unix,dos,mac
syntax enable
set background=dark
set termguicolors
set backspace=eol,start,indent
set hidden
set number

call plug#begin()

" SCENARIO 1: No semantic highlighing when only LanguageClient_neovim installed
Plug 'autozimu/LanguageClient-neovim', { 'branch': 'next', 'do': 'bash install.sh' }
Plug 'jackguo380/vim-lsp-cxx-highlight', { 'tag': '20f0f7c' }  " Version with nvim-lsp support

" SCENARIO 2: Semantic highlighting works; only nvim-lsp installed
"Plug 'neovim/nvim-lsp'
"let s:have_nvim_lsp = 1
"Plug 'jackguo380/vim-lsp-cxx-highlight', { 'tag': '20f0f7c' }  " Version with nvim-lsp support

" SCENARIO 3: Semantic highlighting works; both nvim-lsp and LanguageClient-neovim installed
"Plug 'neovim/nvim-lsp'
"let s:have_nvim_lsp = 1
"Plug 'autozimu/LanguageClient-neovim', { 'branch': 'next', 'do': 'bash install.sh' }
"Plug 'jackguo380/vim-lsp-cxx-highlight', { 'tag': '20f0f7c' }  " Version with nvim-lsp support

" SCENARIO 4: Semantic highlighting WORKS; only LanguageClient-neovim installed
"Plug 'autozimu/LanguageClient-neovim', { 'branch': 'next', 'do': 'bash install.sh' }
"Plug 'jackguo380/vim-lsp-cxx-highlight', { 'tag': '71490fd' }  " Version BEFORE nvim-lsp support

call plug#end()

" --- nvim-lsp options
if exists('s:have_nvim_lsp')
lua <<EOF
  require'nvim_lsp'.ccls.setup{ init_options = { highlight = { lsRanges = true; } } }
EOF
  autocmd Filetype cpp setlocal omnifunc=v:lua.vim.lsp.omnifunc
endif

" --- LanguageClient-neovim options
let s:ccls_settings = { 'highlight': { 'lsRanges' : v:true }, }
let g:LanguageClient_serverCommands = {}
let g:LanguageClient_serverCommands.cpp = ['ccls', '-init=' . json_encode(s:ccls_settings)]
let g:LanguageClient_serverCommands.c = ['ccls', '-init=' . json_encode(s:ccls_settings)]
setlocal completefunc=LanguageClient#complete

let g:lsp_cxx_hl_log_file = '/tmp/vim-lsp-cxx-hl.log'
let g:lsp_cxx_hl_verbose_log = 1