如何为当前项目配置.ycm_extra_conf.py包括PATH

我的目录树显示如下：

TOP
├── debug
│ ├── debug.c
│ ├── debug.h
│ ├── debug.mk
│ └── instrument.c
├── driver
│ ├── driver.c
│ ├── driver_ddi.c
│ ├── driver_ddi.h
│ ├── driver.h
│ └── driver.mk
├── include
│ └── common.h
├── libs
├── Makefile
├── mw
│ ├── manager.c
│ └── mw.mk
└── root
  ├── main.c
  └── root.mk

我将.ycm_extra_conf.py复制到TOP,同时我也会在TOP生成标签和cscope文件,因此每次在TOP上打开文件,如：

howchen@host:~/Work/c/sample/src
-> gvim ./driver/driver.c

以确保每次可以在VIM中添加标签和cscope文件.问题是,如果我打开driver.c,其中包含头文件：driver.h,driver_ddi.h,debug.h,common.h,代码如下：

#include <stdio.h>
#include <stdlib.h>
#include "math.h"
#include "common.h"
#include "debug.h"
#include "driver_ddi.h"
#include "driver.h"

合成或YCM总是显示它找不到common.h和debug.h,其他头文件都可以.

我的YCM和合成配置部分在vimrc文件中：

" YCM
"   let g:ycm_extra_conf_globlist = ['~/.vim/bundle/YouCompleteMe/cpp/ycm/*','!~/*']
    let g:ycm_global_ycm_extra_conf = '~/.vim/bundle/YouCompleteMe/cpp/ycm/.ycm_extra_conf.py'

" Syntastic
    let g:syntastic_c_checkers=['make']
    let g:syntastic_always_populate_loc_list = 1
    let g:syntastic_check_on_open=1
    let g:syntastic_enable_signs=1
    let g:syntastic_error_symbol = '?'
    let g:syntastic_warning_symbol = '?'
    set statusline+=%#warningmsg#
    set statusline+=%{SyntasticStatuslineFlag()}
    set statusline+=%*gbar

我的.ycm_extra_conf.py将flags变量写为：

flags = [
'-Wall','-Wextra','-Werror','-Wc++98-compat','-Wno-long-long','-Wno-variadic-macros','-fexceptions','-DNDEBUG','-std=c99',# ...and the same thing goes for the magic -x option which specifies the
# language that the files to be compiled are written in. This is mostly
# relevant for c++ headers.
# For a C project,you would set this to 'c' instead of 'c++'.
'-x',#I don't know if I need remove -x
'c','-isystem','../llvm/include','../llvm/tools/clang/include','-I','.','../driver'
'-I','../debug'
'-I','../include'
'-I','../include'
]

我设置的任何错误的标志？