[FFmpeg-devel] [PATCH v2] Replace arrays of pointers to strings by arrays of strings

[Mark Thompson]

On 06/01/2021 09:34, Marton Balint wrote:
> On Wed, 6 Jan 2021, Andreas Rheinhardt wrote:
>> When the difference of the longest size and the average size of
>> collection of strings is smaller than the size of a pointer, it makes
>> sense to store the strings directly in an array instead of using an
>> array of pointers to strings (unless doing so precludes deduplicating
>> strings); doing so also avoids relocations. This requirement is
>> fulfilled for several arrays of pointers to strings that are changed in
>> this commit.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>> ---
>> Now used sizeof("longest string") for the array element size.
> 
> Duplicating the "longest string" is very ugly, I don't find it better than a constant number, because a sizeof still does not say it tries to find the longest string.
> 
> TBH I am not a fan of these kind of patches for a few byte of savings, and when changing the list of strings it can actually become worse which won't be checked by anybody...

I'm inclined to agree.

This case is particularly evil because the compiler is unable to detect off-by-one errors, so missing the longest element may silently result in messed-up strings and crashes.

- Mark