[FFmpeg-devel] [PATCH 1/4] lavu: add simple array implementation

[Lukasz Marek]

>>   mem.c |   13 +++++++++++++
>>   mem.h |   19 +++++++++++++++++--
>>   2 files changed, 30 insertions(+), 2 deletions(-)
>> 7fad1be9083fcaef4435fa0273f79bceca98821b  0001-lavu-mem-add-av_dynarray_add_nofree-function.patch
>>  From 4cadb3328ba018b37c5dfe05a637b50a262151c6 Mon Sep 17 00:00:00 2001
>> From: Lukasz Marek <lukasz.m.luki at gmail.com>
>> Date: Tue, 25 Feb 2014 01:06:06 +0100
>> Subject: [PATCH] lavu/mem: add av_dynarray_add_nofree function
>>
>> av_dynarray_add_nofree function have similar functionality
>> as existing av_dynarray_add, but it doesn't deallocate memory
>> on fails.
>>
>> TODO: minor bump and update doc/APIChanges
>>
>> Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
>> ---
>>   libavutil/mem.c |   13 +++++++++++++
>>   libavutil/mem.h |   19 +++++++++++++++++--
>>   2 files changed, 30 insertions(+), 2 deletions(-)
>>
>> diff --git a/libavutil/mem.c b/libavutil/mem.c
>> index 7206ddc..b9b5742 100644
>> --- a/libavutil/mem.c
>> +++ b/libavutil/mem.c
>> @@ -278,6 +278,19 @@ void *av_memdup(const void *p, size_t size)
>>       return ptr;
>>   }
>>
>> +int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem)
>> +{
>
>> +    intptr_t *tab = *(intptr_t**)tab_ptr;
>
> undefined behavior (strict aliasing violation)


Can you tell how it is wrong?

>
>> +
>> +    AV_DYNARRAY_ADD(INT_MAX, sizeof(*tab), tab, *nb_ptr, {
>> +        tab[*nb_ptr] = (intptr_t)elem;
>> +        *(intptr_t **)tab_ptr = tab;
>> +    }, {
>> +        return AVERROR(ENOMEM);
>> +    });
>
> cant comment, i have no clue what this does
>
> [...]