freebsd4_ucontext
struct freebsd4_ucontext uc;
struct freebsd4_ucontext *ucp;
ASSYM(UC4_EFLAGS, offsetof(struct freebsd4_ucontext, uc_mcontext.mc_eflags));
ASSYM(UC4_GS, offsetof(struct freebsd4_ucontext, uc_mcontext.mc_gs));
struct freebsd4_ucontext sf_uc; /* = *sf_ucontext */
struct freebsd4_ucontext *uc_link;
char sigcntxp_l_[PADL_(const struct freebsd4_ucontext *)]; const struct freebsd4_ucontext * sigcntxp; char sigcntxp_r_[PADR_(const struct freebsd4_ucontext *)];