Added flag to turn off clang completion if desired

autoload/youcompleteme.vim

@@ -60,7 +60,10 @@ function! youcompleteme#Enable()
   exe 'python sys.path = sys.path + ["' . s:script_folder_path . '/../python"]'
   py import ycm
   py identcomp = ycm.IdentifierCompleter()
-  py clangcomp = ycm.ClangCompleter()
+
+  if g:ycm_clang_completion_enabled
+    py clangcomp = ycm.ClangCompleter()
+  endif
 
   " Calling this once solves the problem of BufRead/BufEnter not triggering for
   " the first loaded file. This should be the last command executed in this

plugin/youcompleteme.vim

@@ -29,6 +29,9 @@ let g:loaded_youcompleteme = 1
 let s:save_cpo = &cpo
 set cpo&vim
 
+let g:ycm_clang_completion_enabled =
+      \ get(g:, 'ycm_clang_completion_enabled', 1)
+
 " On-demand loading. Let's use the autoload folder and not slow down vim's
 " startup procedure.
 augroup youcompletemeStart

python/ycm.py

@@ -22,6 +22,7 @@ import vim
 import indexer
 
 MIN_NUM_CHARS = int( vim.eval( "g:ycm_min_num_of_chars_for_completion" ) )
+CLANG_COMPLETION_ENABLED = int( vim.eval( "g:ycm_clang_completion_enabled" ) )
 CLANG_FILETYPES = set( [ 'c', 'cpp', 'objc', 'objcpp' ] )
 MAX_IDENTIFIER_COMPLETIONS_RETURNED = 10
 
@@ -211,6 +212,9 @@ def CurrentLineAndColumn():
 
 
 def ShouldUseClang( start_column ):
+  if not CLANG_COMPLETION_ENABLED:
+    return False
+
   filetype = vim.eval( "&filetype" )
   if filetype not in CLANG_FILETYPES:
     return False
@@ -332,4 +336,3 @@ def RemoveIdentFreeText( text ):
     re.DOTALL | re.MULTILINE )
 
   return re.sub( pattern, replacer, text )
-