Read clang checker flags from clang_complete file

Neomake didn't provide a way to pass clang flags, so I had to implement
it myself. (It is not perfect though)

neostrophic.vim

@@ -51,6 +51,10 @@ function! s:set_indent()
 endfunction
 
 
+function! s:read_clangflags()
+    return split(join(readfile(getcwd() . "/.clang_complete"), "\n"))
+endfunction
+
 " --- Start
 if(!has("python3"))
     echo "You should install python neovim module. `pip install neovim`"
@@ -325,6 +329,24 @@ let g:SuperTabDefaultCompletionType = "<c-n>"
 " LessSpace
 let g:lessspace_blacklist = ['markdown']
 
+" Neomake
+let s:default_clang_args = ['-std=c++14', '-fsyntax-only', '-Wall', '-Wextra']
+let g:neomake_cpp_clang_maker = {
+    \'args': s:default_clang_args
+    \ }
+let g:neomake_cpp_enabled_makers = ['clang']
+
+function! s:build_clang_args()
+    if filereadable(getcwd() . "/.clang_complete")
+        " Read flags
+        let newflags = s:default_clang_args + s:read_clangflags()
+        " Build list with no duplicates for sure
+        let g:neomake_cpp_clang_maker.args = filter(copy(newflags), 'index(newflags, v:val, v:key+1)==-1')
+    endif
+endfunction
+autocmd! FileType cpp nested call s:build_clang_args()
+
+
 " --- Keymaps
 " Commonly used commands
 nnoremap <silent> <C-z> :u<CR>