ListIterator<Instr> instrs;
BasicBlock geb = cfg.getGlobalEnsureBB();
if (geb == null) {
Variable exc = cfgScope.createTemporaryVariable();
geb = new BasicBlock(cfg, Label.getGlobalEnsureBlockLabel());
geb.addInstr(new ReceiveJRubyExceptionInstr(exc)); // JRuby implementation exception handling
geb.addInstr(new ThrowExceptionInstr(exc));
cfg.addGlobalEnsureBB(geb);
}
instrs = geb.getInstrs().listIterator(geb.getInstrs().size());