[vlc-devel] [vlc-commits] modules: Adjust integer limits

[Hugo Beauzée-Luyssen]

On 10/14/2016 06:26 PM, Rémi Denis-Courmont wrote:
> 	Hello,
>
> Le perjantaina 14. lokakuuta 2016, 18.22.00 EEST Hugo Beauzée-Luyssen a
> écrit :
>> vlc | branch: master | Hugo Beauzée-Luyssen <hugo at beauzee.fr> | Fri Oct 14
>> 18:21:08 2016 +0200| [e908026c45d91a18b5a3835953edd47a822b4a40] |
>> committer: Hugo Beauzée-Luyssen
>>
>> modules: Adjust integer limits
>>
>>> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=e908026c45d91a18b5a
>>> 3835953edd47a822b4a40
>> ---
>>
>>  src/modules/entry.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/modules/entry.c b/src/modules/entry.c
>> index ae8e041..7698499 100644
>> --- a/src/modules/entry.c
>> +++ b/src/modules/entry.c
>> @@ -129,8 +129,8 @@ static module_config_t *vlc_config_create (module_t
>> *module, int type) memset (tab + confsize, 0, sizeof (tab[confsize]));
>>      if (IsConfigIntegerType (type))
>>      {
>> -        tab[confsize].max.i = INT_MAX;
>> -        tab[confsize].min.i = INT_MIN;
>> +        tab[confsize].max.i = INT64_MAX;
>> +        tab[confsize].min.i = INT64_MIN;
>
> When 64-bits was added, we kept the INT boundaries by default.
> In many cases we have legacy code along the lines of:
>
> int a = var_InheritInteger(obj, "varname");
>
> That can result in arithmetic overflow with your patch.
>
> Maybe we should have helper macros to set the range (e.g. add_int64,
> add_uint32).
>
>
>>      }
>>      else if( IsConfigFloatType (type))
>>      {
>>
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>
>
Hi,

That's a fair point. Although int a = var_InheritInteger should and will 
trigger a compiler warning, I'm afraid fixing all call sites could be 
long and painfull, if not error prone...
I have no strong opinion here, beside the fact that without this commit 
(or with Filip recent commit, enforcing the check), any int64 passed 
through command line will be clamped in between the wrong values.

Regards,