ref: 332f07d78e1a575af02fffab762fdd9429b5ffd2
dir: /sys/src/cmd/python/Python/sigcheck.c/
/* Sigcheck is similar to intrcheck() but sets an exception when an
   interrupt occurs.  It can't be in the intrcheck.c file since that
   file (and the whole directory it is in) doesn't know about objects
   or exceptions.  It can't be in errors.c because it can be
   overridden (at link time) by a more powerful version implemented in
   signalmodule.c. */
#include "Python.h"
/* ARGSUSED */
int
PyErr_CheckSignals(void)
{
	if (!PyOS_InterruptOccurred())
		return 0;
	PyErr_SetNone(PyExc_KeyboardInterrupt);
	return -1;
}