title: YouCompleteMe(vim plugin) GoToDefinition doesn't work
body: <pre><code>let g:ycm_global_ycm_extra_conf='~/.vim/bundle/youcompleteme/.ycm_extra_conf.py'
  let g:ycm_min_num_of_chars_for_completion=1
  let g:ycm_confirm_extra_conf=0
  let g:ycm_autoclose_preview_window_after_completion = 1 
  nnoremap &lt;F5&gt;           :YcmForceCompileAndDiagnostics&lt;CR&gt;
  nnoremap &lt;leader&gt;gic    :YcmCompleter GoToInclude&lt;CR&gt;
  nnoremap &lt;leader&gt;gdc    :YcmCompleter GoToDeclaration&lt;CR&gt;
  nnoremap &lt;leader&gt;gdf    :YcmCompleter GoToDefinition&lt;CR&gt;
  nnoremap &lt;leader&gt;gip    :YcmCompleter GoToImprecise&lt;CR&gt;
  nnoremap &lt;leader&gt;f      :YcmCompleter FixIt&lt;CR&gt;
  </code></pre>
  
  <p>This is the part of <code>~/.vimrc</code> related to <code>ycm</code>.<br>
  Also, <code>flags</code> in <code>.ycm_extra_conf.py</code> contains the result of <code>echo | gcc -std=c++11 -v -E -x c++ -</code> which refers to include paths for <code>C-family</code>.  </p>
  
  <ul>
  <li><p>The problem<br>
  While <code>auto-complete</code> works fine, <code>GoToDefinition</code> doesn't work at all.<br>
  (Here what <code>works</code> means, <code>ycm</code> can recognize local header file in projects.)<br>
  According to the <a href="https://github.com/Valloric/YouCompleteMe#user-content-the-gotodefinition-subcommand" rel="nofollow noreferrer">NOTE</a>, <code>GoToDefinition</code> only works in the current <code>translation unit</code>.<br>
  However, <code>GoToDefinition</code> only works in the file being edited in my case.  </p></li>
  <li><p>What I tried: Give up to make <code>.ycm_extra_conf.py</code> global  </p>
  
  <ol>
  <li>Copy <code>.ycm_extra_conf.py</code> into the top of project and modify <code>g:ycm_global_ycm_extra_conf</code> in <code>~/.vimrc</code>.</li>
  <li>Do <code>YcmForceCompileAndDiagnostics</code></li>
  <li>Check <code>final_flags</code> in <code>FlagsForFile</code> function in <code>.ycm_extra_conf.py</code> <a href="https://github.com/Valloric/ycmd/blob/master/cpp/ycm/.ycm_extra_conf.py" rel="nofollow noreferrer">file</a>.</li>
  <li><code>final_flags</code> was like this.<br>
  <code>['-Wall', '-Wextra', '-Werror', '-Wc++98-compat', '-Wno-long-long', '-Wno-variadic-macros', '-fexceptions', '-DN    DEBUG', '-DUSE_CLANG_COMPLETER', '-std=c++11', '-x', 'c++', '-isystem', '/home/illuxic/Redbase/../BoostParts', '    -isystem', '/System/Library/Frameworks/Python.framework/Headers', '-isystem', '/home/illuxic/Redbase/../llvm/inc    lude', '-isystem', '/home/illuxic/Redbase/../llvm/tools/clang/include', '-I', '/home/illuxic/Redbase/.', '-I', '    /home/illuxic/Redbase/./ClangCompleter', '-isystem', '/home/illuxic/Redbase/./tests/gmock/gtest', '-isystem', '/    home/illuxic/Redbase/./tests/gmock/gtest/include', '-isystem', '/home/illuxic/Redbase/./tests/gmock', '-isystem'    , '/home/illuxic/Redbase/./tests/gmock/include', '-isystem', '/usr/include/c++/5', '-isystem', '/usr/include/x86    _64-linux-gnu/c++/5', '-isystem', '/usr/include/c++/5/backward', '-isystem', '/usr/lib/gcc/x86_64-linux-gnu/5/in    clude', '-isystem', '/usr/local/include', '-isystem', '/usr/lib/gcc/x86_64-linux-gnu/5/include-fixed', '-isystem    ', '/usr/include/x86_64-linux-gnu', '-isystem', '/usr/include']</code></li>
  <li><code>GoToDefinition</code> still gives me '<code>RuntimeError: Can't jump to definition.</code>'</li>
  </ol></li>
  </ul>
  
  <p>How can I make <code>GoToDefinition</code> work?<br>
  It can't recognize not only indirectly included header files but also directly included header files.</p>