undeclared identifier 'sigset' in new port

[Dimitri Karamazov]

I guess this is another deprecated api that is removed in OpenBSD,
can anyone suggest a replacement for this? I've attached the code
which utilizes it below.

normalize.cpp:557:3: error: use of undeclared identifier 'sigset'
  sigset(SIGUSR1, increase_verbosity);
  ^
normalize.cpp:558:3: error: use of undeclared identifier 'sigset'
  sigset(SIGUSR2, decrease_verbosity);
  ^
2 errors generated.
Error while executing c++ -DHAVE_CONFIG_H -I. -I../../../code -I../../../code 
-I./.. -DINSTALLDIR="/usr/local/bin"
-I/usr/local/include -D__STDC_LIMIT_MACROS -D_4ti2_GMP_ -O2 -pipe -MT 
normalize.lo -MD -MP -MF .deps/normalize.Tpo -c
normalize.cpp -fPIC -DPIC -o .libs/normalize.o
*** Error 1 in code/latte/normalize (Makefile:1050 'normalize.lo')
*** Error 1 in code/latte (Makefile:2538 'all-recursive': @fail=;  if 
(target_option=k; case ${target_option-} in  ?)
;;  *) echo "am__make_...)
*** Error 1 in code (Makefile:870 'all-recursive': @fail=;  if 
(target_option=k; case ${target_option-} in  ?) ;;  *)
echo "am__make_running...)
*** Error 2 in code (Makefile:782 'all')
*** Error 1 in /usr/ports/pobj/latte-integrale/latte-version_1_7_5 
(Makefile:939 'all-recursive': @fail=;  if
(target_option=k; case ${targe...)
*** Error 2 in . (/usr/ports/infrastructure/mk/bsd.port.mk:2925 
'/usr/ports/pobj/latte-integrale/.build_done': @cd
/usr/ports/pobj/latte-int...)
*** Error 2 in /usr/ports/mystuff/math/latte-integrale 
(/usr/ports/infrastructure/mk/bsd.port.mk:2584 'build':
@lock=latte-integrale;  expor...)

----> only part which references sigset

#include <signal.h>

static void increase_verbosity(int sig)
{
  verbosity++;
  cerr << "Increased verbosity to " << verbosity << endl;
}

static void decrease_verbosity(int sig)
{
  verbosity--;
  cerr << "Decreased verbosity to " << verbosity << endl;
}

void install_verbosity_control_signal_handlers()
{
  sigset(SIGUSR1, increase_verbosity);
  sigset(SIGUSR2, decrease_verbosity);
}