__RETURNS_TWICE
extern int setjmp(jmp_buf) __RETURNS_TWICE;
extern int _setjmp(jmp_buf) __RETURNS_TWICE;
extern int sigsetjmp(sigjmp_buf, int) __RETURNS_TWICE;
extern int getcontext(ucontext_t *) __RETURNS_TWICE;
extern int getcontext_extd(ucontext_t *, uint32_t) __RETURNS_TWICE;
extern pid_t vfork(void) __RETURNS_TWICE;
extern int _getcontext(ucontext_t *) __RETURNS_TWICE;
extern void _ex_clnup_handler(void *, void (*)(void *)) __RETURNS_TWICE;
extern void _ex_unwind_local(void) __RETURNS_TWICE;
extern int _sigsetjmp(sigjmp_buf, int) __RETURNS_TWICE;
extern int sigsetjmp(sigjmp_buf, int) __RETURNS_TWICE;
extern pid_t vforkx(int) __RETURNS_TWICE;
extern int on_trap(on_trap_data_t *, uint_t) __RETURNS_TWICE;
int setjmp(label_t *) __RETURNS_TWICE;
int on_fault(label_t *) __RETURNS_TWICE;