[U-Boot] [PATCH 01/19] lib: errno: introduce errno_str(): returns errno related message

[Przemyslaw Marczak]

Hello Joakim,

On 10/10/2014 07:03 AM, Joakim Tjernlund wrote:
> Przemyslaw Marczak <p.marczak at samsung.com> wrote on 2014/10/09 18:23:54:
>>
>> Hello Joakim,
>>
>> On 10/09/2014 08:46 AM, Joakim Tjernlund wrote:
>>>> From: Przemyslaw Marczak <p.marczak at samsung.com>
>>>>
>>>> The functions error's numbers are standarized - but the error
>>>> messages are not.
>>>>
>>>> The errors are often handled with unclear error messages,
>>>> so why not use an errno standarized messages.
>>>>
>>>> Advantages:
>>>> - This could decrease the binary size.
>>>
>>> Having an array of string ptrs adds some extra space needs.
>>> Each str needs a ptr and that ptr needs relocation, 8 bytes on 32 bits
>>>
>>> If you want to save space do this instead
>>> static const char const errno_message[] =
>>>     "Success\0Operation not permitted\0No such file or directory" etc.
>>> Then count "\0" to find the error msg.
>>>
>>>         Jocke
>>>
>>
>> Is this really a problem to add some array with the pointers?
>
> Probably not, I only mentioned this because you claimed it could reduces
> size
> as if that was important to you.
>
>   Jocke
>

I meant that it will reduce the size, if we could change the whole code 
"common message string parts" with a pointer to some standard message.

>>
>> You are right, this array requires some additional space, but this is
>> not the main reason of introducing this function. This can be enabled
>> optional, so maybe for the less memory and slower devices this shouldn't
>
>> be used - but in the other way, we see many text messages in the code
>> that could be replaced with the one from that array.
>> So, which is better?
>>
>> This helps me sometimes, so I added this as some extra feature.
>
>
>

Your notice about the size was right, but I hope that U-Boot is used for 
machines, in which this doesn't make a difference - and the code
is still simple and the "error messages" - means what they should mean.

Best Regards,
-- 
Przemyslaw Marczak
Samsung R&D Institute Poland
Samsung Electronics
p.marczak at samsung.com