CCS compile problem - identifier "_Bool" is undefined

HI,

I'm using CCS ( Version: 5.2.1.00018 ) to develop code for controlSTICK Piccolo F28069. When rebuilding the project, I got the error message, identifier "_Bool" is undefined. I've already re-defined _Bool as bool_t as the following.

typedef _Bool bool_t;

I've read the comment for this type re-define in other header file as the following.

// C99 defines boolean type to be _Bool, but this doesn't match the format of
// the other standard integer types.  bool_t has been defined to fill this gap.
typedef _Bool bool_t;

I have no idea why this error happened. Could you help me to resolve this issue?

Thanks!