stddef.h

一个PIC的demo程序包

#ifndef	_STDDEF
typedef	int		ptrdiff_t;	/* result type of pointer difference */
typedef	unsigned	size_t;		/* type yielded by sizeof */
typedef unsigned short	wchar_t;	/* wide char type */
#define	_STDDEF
#define	offsetof(ty, mem)	((int)&(((ty *)0)->mem))
#endif	_STDDEF

#ifndef	NULL
#define	NULL	((void *)0)
#endif	NULL

extern int	errno;			/* system error number */