text: 
  /* a.h */
  
  #ifndef __A_H__
  #define __A_H__
  
  #include "b.h"
  
  #ifndef PROJECT_DEVICE_MODE
  //QWQQQ (compile here ...)
  #define PROJECT_DEVICE_MODE PWM_MODE
  #endif
  
  #define LIGHT_DEVICE_MODE 	PROJECT_DEVICE_MODE
  
  extern int test_a;
  
  #endif /* __A_H__ */
  