Re: [PATCH v2 5/5] libxl, hvmloader: Don't relocate memory for MMIO hole

[George Dunlap <george.dunlap@eu.citrix.com>]

On 20/06/13 11:56, Jan Beulich wrote:
>>>> On 20.06.13 at 12:29, Stefano Stabellini <stefano.stabellini@eu.citrix.com> wrote:
>> On Thu, 20 Jun 2013, George Dunlap wrote:
>>> On 20/06/13 11:12, Jan Beulich wrote:
>>>> However, if we want to be on the safe side and also make the
>>>> code work with a compiler that doesn't have a built-in _Bool, I'd
>>>> think
>>>>
>>>>       allow_memory_relocate = !s || strtoll(s, NULL, 0);
>>>>
>>>> would be the better statement (without any if() surrounding it,
>>>> and without the variable declaration having an initializer.
>>> Doing this would effectively hide the "default" value.  This is bad because 1)
>>> it's not clear what the default is to someone just scanning the code, 2) it's
>>> hard to change.  (Consider how you'd modify the above statement if you wanted
>>> to default to 0 instead.)
>> I would avoid the strtoll altogether:
>>
>> if (s != NULL && s[0] != '0')
>>      allow_memory_relocate = 1;
>> else
>>      allow_memory_relocate = 0;
> Let's not add hacks like this - a string of "0x1" ought to not be
> mis-interpreted as meaning 0.

I'm pretty sure the xs protocol specifies "0" or "1" for booleans, so 
"0x1" would be undefined anyway.

  -George