#include <inttypes.h>
#include <signal.h>
#include <stddef.h>
#include <sys/ucontext.h>

SIG_BLOCK
SIG_SETMASK

-- Offsets of the fields in the ucontext_t structure.
#define ucontext(member)	offsetof (ucontext_t, member)
#define mcontext(member)	ucontext (uc_mcontext.member)

UCONTEXT_SIGMASK		ucontext (uc_sigmask)
MCONTEXT_SC_A_0			mcontext (sc_a[0])
MCONTEXT_SC_PC			mcontext (sc_pc)
