[Insight-developers] Dashboard Cleanup: mini0.nlm MacOSX-cross-rosetta : 50 tests failing

[Luis Ibanez]

Wow...


This code is really fragile:


>  for (d=(dim)-1, (I)=(coord)[d--];           \
>       d >= 0;                                \
>       d--) {                                 \
>    (I) = (coord)[d] + (size)[d]*(I);


It looks like it meant to do:

d = dim - 1;
l = coord[d];
d--;

while( d >= 0 )
{
I = coord[d] + size[d] * I;
d--;
}


It probably should be:

l = coord[ d - 1 ];
d = dim - 2;

while( d >= 0 )
{
I = coord[d] + size[d] * I;
d--;
}


I agree with Kevin, in that the compiler
is most likely flagging a real error here.


     Luis


--------------------------------------------------------------------
On Thu, Jan 28, 2010 at 10:34 AM, Kevin H. Hobbs <hobbsk at ohiou.edu> wrote:
> On 01/28/2010 10:12 AM, Michel Audette wrote:
>> Hi Kevin,
>>
>> I've just committed a new version of reorder, which now includes a
>> pragma for this warning that was present prior to this week's commits.
>>
>> Can you give it a try and report back? Thanks for your kind support.
>>
>> Best wishes,
>>
>
> The build is under way on lance.
>
> I noticed that the same warning is happening in subset.c near the same
> macro NRRD_INDEX_GEN.
>
> I took a look at this macro and it scares me a little because of the use
> of the post decrement on d as part of the access to an index as part of
> a for loop... I think the compiler is really trying to tell us
> something. I at least am having a hard time telling what dim has to be
> to to avoid ever trying to access coord[-1]...
>
> ******** NRRD_INDEX_GEN
> **
> ** Given a coordinate array "coord", as well as the array sizes "size"
> ** and dimension "dim", calculates the linear index, and stores it in
> ** "I".
> */
> #define NRRD_INDEX_GEN(I, coord, size, dim)   \
> do {                                          \
>  int d;                                      \
>  for (d=(dim)-1, (I)=(coord)[d--];           \
>       d >= 0;                                \
>       d--) {                                 \
>    (I) = (coord)[d] + (size)[d]*(I);         \
>  }                                           \
> } while (0)
>
>