a_false_status.c

#include <ruby.h>
#include <node.h>

int main(int argc, char **argv) {
  ruby_init();
  ruby_script("embedded");

  // The bizness
  rb_thread_t th = ALLOC(struct rb_thread);                 \
  th->last_status = 0;
  rb_p(th->last_status);

  return 0;
}

eval.c

// Eliding many variable sets in this
#define THREAD_ALLOC(th) do {\
    th = ALLOC(struct rb_thread);\
\
    th->last_status = 0;\
} while (0)

// Wait for it.
static rb_thread_t
rb_thread_alloc(klass)
    VALUE klass;
{
    rb_thread_t th;
    struct RVarmap *vars;

    THREAD_ALLOC(th);
    th->thread = Data_Wrap_Struct(klass, thread_mark, thread_free, th);

    for (vars = th->dyna_vars; vars; vars = vars->next) {
	if (FL_TEST(vars, DVAR_DONT_RECYCLE)) break;
	FL_SET(vars, DVAR_DONT_RECYCLE);
    }
    return th;
}

static void
rb_thread_restore_context_0(rb_thread_t th, int exit)
{
    static rb_thread_t tmp;
    static int ex;
    static VALUE tval;

    //  And here we are. Now, the question is: uh, what?
    rb_last_status = th->last_status;
    ruby_safe_level = th->safe;
    
}