throw from signal handler

sigexcept.cc

#include <err.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <machine/sigframe.h>

static void
handler(int sig __unused, siginfo_t *, void *x)
{
	ucontext_t *xx;

	xx = static_cast<ucontext_t *>(x);
	xx->uc_mcontext.mc_onstack += 1;
//	abort();
	throw 12;
}

int
main(int ac __unused, char **av __unused)
{
	struct sigaction sa;
	struct sigframe xxx;

	memset(&xxx, 0, sizeof(xxx));
	memset(&sa, 0, sizeof(sa));
	sa.sa_sigaction = handler;
	sa.sa_flags = SA_SIGINFO;
	if (sigaction(SIGUSR1, &sa, NULL) == -1)
		err(1, "signal");
	try {
		if (kill(getpid(), SIGUSR1) == -1)
			err(1, "kill");
	} catch (int yy) {
		printf("yy %d\n", yy);
	}
	printf("survived\n");
	return (0);
}