Re: [Qemu-devel] [PATCH v5 05/46] qapi: Test use of 'number' within alternates

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> On 09/24/2015 10:29 AM, Markus Armbruster wrote:
>
>>>>> +
>>>>> +    /* FIXME: Order of alternate should not affect semantics */
>>>>
>>>> Inhowfar does it affect semantics?  Or asked differently: what exactly
>>>> is wrong with this test now?
>>>>
>>>>> +    v = visitor_input_test_init(data, "42");
>>>>> +    visit_type_AltThree(v, &three, NULL, &error_abort);
>>>>> +    g_assert_cmpint(three->kind, ==, ALT_THREE_KIND_N);
>>>>> +    g_assert_cmpfloat(three->n, ==, 42);
>>>>> +    qapi_free_AltThree(three);
>>>>> +    one = NULL;
>>>
>>>
>>> AltTwo and AltThree are ostensibly the same struct (two branches, one
>>> for 'str' and one for 'number', just in a different order), but they
>>> parsed differently (AltTwo failed, AltThree succeeded).  The bug is
>>> fixed later when the order of the branch declaration no longer impacts
>>> the result of the parse.
>> 
>> Then nothing is wrong with this test case, and the FIXME doesn't belong
>> here.
>
> Actually, the test for AltThree succeeds only by accident. There are two
> bugs at play; when I fix the first bug (order shouldn't matter: AltTwo
> and AltThree should parse identically), then the second bug is finally
> exposed (integers aren't being parsed as numbers, in either AltTwo or
> AltThree). But I can certainly rework the FIXMEs both here and on the
> first fix (19/46) to make it more obvious what the second fix (20/46) is
> good for.

Yes, please.  I find the FIXME quoted above confusing, because it makes
me look for problems exposed by this test when there are none.