Potential division by zero in SystemC Library

[sumit_tuwien]

Hi All,

 

There are many points where there are division by 0 observed and can show up any time. We have found no protection mechanism for that.

 

One such example  (sysc/datatypes/fx/scfx_rep.cpp) : 

 

     switch( numrep )

    {

case SC_BIN:

case SC_BIN_US:

case SC_CSD:

   step = 1;

  break;

case SC_OCT:

case SC_OCT_US:

   step = 3;

   break;

case SC_HEX:

case SC_HEX_US:

   step = 4;

   break;

default:

   step = 0;

    }

 

    msb = (int) ceil( double( msb + 1 ) / step ) * step - 1;

 

    lsb = (int) floor( double( lsb ) / step ) * step;

 

    if( msb < 0 )

    {

s += '.';

if( fmt == SC_F )

{

   int sign = ( b.is_neg() ) ? ( 1 << step ) - 1 : 0;

   for( int i = ( msb + 1 ) / step; i < 0; i ++ )

   {

 

if numrep defaults, there will be division by zero. Functionally it never showed up, still there is a chance this will be triggered. 

 

We can share the complete lint report if you are interested.

 

Regards, Sumit

[Philipp A Hartmann]

As in the other post about dereferencing NULL pointers, I suspect that (all of?) these reports are false positives as well.

 

If you want to silence the linter about these, just add calls to explicitily non-returning functions like std::terminate. On the other hand, a division by zero will usually abort your simulation as well. ;-)

 

/Philipp