[FFmpeg-devel] [PATCH 3/4] avfilter/vf_ccrepack: Constify filter

[Andreas Rheinhardt]

Paul B Mahol:
> On Thu, Jun 29, 2023 at 9:35 PM Andreas Rheinhardt <
> andreas.rheinhardt at outlook.com> wrote:
> 
>> Paul B Mahol:
>>> On Thu, Jun 29, 2023 at 8:18 PM Andreas Rheinhardt <
>>> andreas.rheinhardt at outlook.com> wrote:
>>>
>>>> The discrepancy between the definition and the declaration
>>>> in allfilters.c is actually UB.
>>>>
>>>
>>> I get no such message with ubsan.
>>>
>>
>> UBSan is a runtime UB-detector, not a compile-time UB detector.
>> The earlier code is UB because of 6.2.7 (2) of C11: "All declarations
>> that refer to the same object or function shall have compatible type;
>> otherwise, the behavior is undefined." A type and its const-qualified
>> type are not compatible.
>>
> 
> This is so minor, that it is fully irrelevant.
> 

The actual advantage of these patches is that the objects can be put
into read-only memory (.data.rel.ro in elf).

- Andreas