backend_tests.py 文件源码

def test_functionptr_simple(self):
        ffi = FFI(backend=self.Backend())
        py.test.raises(TypeError, ffi.callback, "int(*)(int)", 0)
        def cb(n):
            return n + 1
        cb.__qualname__ = 'cb'
        p = ffi.callback("int(*)(int)", cb)
        res = p(41)     # calling an 'int(*)(int)', i.e. a function pointer
        assert res == 42 and type(res) is int
        res = p(ffi.cast("int", -41))
        assert res == -40 and type(res) is int
        assert repr(p).startswith(
            "<cdata 'int(*)(int)' calling <function cb at 0x")
        assert ffi.typeof(p) is ffi.typeof("int(*)(int)")
        q = ffi.new("int(**)(int)", p)
        assert repr(q) == "<cdata 'int(* *)(int)' owning %d bytes>" % (
            SIZE_OF_PTR)
        py.test.raises(TypeError, "q(43)")
        res = q[0](43)
        assert res == 44
        q = ffi.cast("int(*)(int)", p)
        assert repr(q).startswith("<cdata 'int(*)(int)' 0x")
        res = q(45)
        assert res == 46