[rtems commit] Use uint32_t instead of long. Use unsigned defines ( Prevent overflows on 16bit targets)

[Sebastian Huber]

On 17/04/13 17:15, Ralf Corsepius wrote:
> On 04/17/2013 02:53 PM, Sebastian Huber wrote:
>> On 04/17/2013 12:19 PM, Ralf Corsepius wrote:
>> [...]
>>> @@ -147,8 +147,8 @@ static uint32_t simple_random(uint32_t v)
>>>
>>>   static unsigned get_bucket_with_random(unsigned count, long random)
>>>   {
>>> -  long unsigned unit = (1U << 31) / count;
>>> -  long unsigned bucket = (long unsigned) random / unit;
>>> +  uint32_t unit = ((uint32_t) 1U << 31) / count;
>>> +  uint32_t bucket = (uint32_t) random / unit;
>>>
>>>     if (bucket != count) {
>>>       return bucket;
>>
>> A long must be able to store a 32-bit integer so there is no need to use
>> uint32_t here.
>
> Such is theory - Realty is different.

This theory is defined in the C standard.

>
> The assumptions of long >= 32 bit only applies to POSIX conformant 
> targets.
>
> RTEMS however supports targets, which are not strictly POSIX 
> compliant, where longs are 16bit => The code above fails to compile 
> the code above when using longs.

I doubt that is a good idea to use RTEMS in such a non-standard 
environment.  It is all right to fix the (32 * 1024) expression, but 
this unsigned long to uint32_t change is nonsense.

-- 
Sebastian Huber, embedded brains GmbH

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