[Mesa-dev] [PATCH] mesa: memset get_unpack_rgba_function's format table to 0.

[Ian Romanick]

On 04/23/2013 09:20 AM, Kenneth Graunke wrote:
> On 04/22/2013 09:17 PM, Ian Romanick wrote:
>> On 04/23/2013 02:39 AM, Kenneth Graunke wrote:
>>> Otherwise, the table could be full of uninitialized garbage.  That means
>>> the NULL check at the bottom might not happen, so we wouldn't get the
>>> _mesa_problem, and we'd then return garbage.
>>>
>>> format_pack.c also has tables like this and memsets them.
>>
>> This *CANNOT* be the right fix.  This just papers over things.  There
>> are a lot of entries in the table that are not initialized when several
>> similar entries are initialized.  For example, *ONE* of the ETC2 entries
>> is missing.  Many of the integer formats are present, but some are
>> missing.  Etc.
>
> Fine.  I sent out patches to add/fix the rest of the unpack functions.

I didn't mean to be so grumpy in my reply.  The jet lag is killing me... 
I only got about 3 hours of sleep last night. :(

> It still seems like we ought to memset() it so that if someone misses a
> new format in the future, they'll hit the _mesa_problem().  And then add
> an assertion...
>
> Or perhaps just add a static assert in this code that MESA_FORMAT_COUNT
> is a particular value, so if people add a new format, they have to add
> unpack code.

Adding a memset and a unit test that verifies that only entry 0 is NULL 
ought to make things future proof...