struct __ucontext;
int getcontext(struct __ucontext *);
-void makecontext(struct __ucontext *, void (*)(void), int, ...);
+void makecontext(struct __ucontext *, void (*)(), int, ...);
int setcontext(const struct __ucontext *);
int swapcontext(struct __ucontext *, const struct __ucontext *);