Rule 17.4 and Rule 14.7

[Kdasari]

Hi Folks,

We appreciate the MISRA-C compliance.

We are making our application code into the MISRA-C compliance and can you please clarify below questions.

1./Rule 14.7: This rule says that array indexing is only allowed for pointer arithmetic. We understand that if we manipulate the pointer we may end up some cases accessing the non existing memory but suppose even if we access through the index and index is beyond the size of array declaration here also we end accessing the non existing memory , We have the below code and I think it is safe away of using? Can you please let us know the motivation of this rule and how indexing can avoid the error? Also let us know that the below code is acceptable or not?

void awe_vecAbs(
const float * src,
int srcInc,
float * dst,
int dstInc,
int blockSize)
{
int i;

for (i = 0; i < blockSize; i++)
{
*dst = fabsf (*src);
src = src + srcInc;
dst = dst + dstInc;
}

)
2./ Rule 14.7 says that the function should have the only one single exit but in some cases it is very difficult to compliance with this especially when we check for the error concealment. Please have a look at below code we still can use if ,else conditions but we end up having more checks like this which will degrade the system performance, Can you please let us know what way we can do this in better and motivation of this Rule?
if (currentObject == NULL)
{
return (E_NOT_OBJECT_POINTER);
}
id = awe_fwGetClassType(currentObject);
if (!IsClassValid(id))
{
return (E_NOT_OBJECT_POINTER);
}
*pObject = currentObject->pNextInstance;
if (*pObject == NULL)
{
return (E_NO_MORE_IOPINS);
}
*pClassID = awe_fwGetClassType(*pObject);
return (0);


Best regards,
Kishore.