No error when no clang support and cpp file opened

Previously, when the user opened a cpp/c/objc/objcpp file and clang support was
not compiled in, there would be an error message printed in vim.

autoload/youcompleteme.vim

@@ -295,7 +295,7 @@ function! s:InvokeCompletion()
 
   " This is tricky. First, having 'refresh' set to 'always' in the dictionary
   " that our completion function returns makes sure that our completion function
-  " is called on every keystroke. Secondly, when the sequence of characters the
+  " is called on every keystroke. Second, when the sequence of characters the
   " user typed produces no results in our search an infinite loop can occur. The
   " problem is that our feedkeys call triggers the OnCursorMovedI event which we
   " are tied to. We prevent this infinite loop from starting by making sure that

cpp/ycm/CMakeLists.txt

@@ -46,6 +46,13 @@ if ( USE_CLANG_COMPLETER AND
     "You HAVE to pick one option. See the docs for more information.")
 endif()
 
+if ( USE_CLANG_COMPLETER )
+  message( "Using libclang to provide semantic completion for C/C++/ObjC" )
+else()
+  message( "NOT using libclang, no semantic completion for C/C++/ObjC will be "
+           "available" )
+endif()
+
 if ( PATH_TO_LLVM_ROOT )
   set( CLANG_INCLUDES_DIR "${PATH_TO_LLVM_ROOT}/include" )
 else()

cpp/ycm/ycm_core.cpp

@@ -29,11 +29,23 @@
 #include <boost/utility.hpp>
 #include <boost/python/suite/indexing/vector_indexing_suite.hpp>
 
+bool HasClangSupport()
+{
+#ifdef USE_CLANG_COMPLETER
+  return true;
+#else
+  return false;
+#endif // USE_CLANG_COMPLETER
+}
+
+
 BOOST_PYTHON_MODULE(ycm_core)
 {
   using namespace boost::python;
   using namespace YouCompleteMe;
 
+  def( "HasClangSupport", HasClangSupport );
+
   class_< IdentifierCompleter, boost::noncopyable >( "IdentifierCompleter" )
     .def( "EnableThreading", &IdentifierCompleter::EnableThreading )
     .def( "AddCandidatesToDatabase",

python/completers/all/hook.py

@@ -17,8 +17,6 @@
 # You should have received a copy of the GNU General Public License
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
-from identifier_completer import IdentifierCompleter
-
 def GetCompleter():
-  return IdentifierCompleter()
+  return None
 

python/completers/c/hook.py

@@ -17,8 +17,12 @@
 # You should have received a copy of the GNU General Public License
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
+import ycm_core
 from completers.cpp.clang_completer import ClangCompleter
 
 def GetCompleter():
+  if ycm_core.HasClangSupport():
     return ClangCompleter()
+  else:
+    return None
 

python/completers/cpp/hook.py

@@ -17,8 +17,12 @@
 # You should have received a copy of the GNU General Public License
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
+import ycm_core
 from clang_completer import ClangCompleter
 
 def GetCompleter():
+  if ycm_core.HasClangSupport():
     return ClangCompleter()
+  else:
+    return None
 

python/completers/objc/hook.py

@@ -17,8 +17,11 @@
 # You should have received a copy of the GNU General Public License
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
+import ycm_core
 from completers.cpp.clang_completer import ClangCompleter
 
 def GetCompleter():
+  if ycm_core.HasClangSupport():
     return ClangCompleter()
-
+  else:
+    return None

python/completers/objcpp/hook.py

@@ -17,8 +17,12 @@
 # You should have received a copy of the GNU General Public License
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
+import ycm_core
 from completers.cpp.clang_completer import ClangCompleter
 
 def GetCompleter():
+  if ycm_core.HasClangSupport():
     return ClangCompleter()
+  else:
+    return None
 

python/ycm.py

@@ -49,6 +49,7 @@ class YouCompleteMe( object ):
     module_path = _PathToFiletypeCompleterPluginLoader( filetype )
 
     completer = None
+    supported_filetypes = [ filetype ]
     if os.path.exists( module_path ):
 
       sys.path.append( os.path.dirname( module_path ) )
@@ -56,10 +57,11 @@ class YouCompleteMe( object ):
       del sys.path[ -1 ]
 
       completer = module.GetCompleter()
-      for supported_filetype in completer.SupportedFiletypes():
+      if completer:
+        supported_filetypes.extend( completer.SupportedFiletypes() )
+
+    for supported_filetype in supported_filetypes:
       self.filetype_completers[ supported_filetype ] = completer
-    else:
-      self.filetype_completers[ filetype ] = None
     return completer