Re: casting on 64/32-bit environment

[Andrew Haley <aph-gcc at littlepinkcloud dot COM>]

Mitja Ursic writes:
 > > 
 > > You're casting from a pointer to an integer.  This is the wrong thing
 > > to do.
 > > 
 > 
 > >  > Down I give a part of a code:
 > >  > 
 > >  > //FUNC.CC
 > >  > void func ()
 > >  > {
 > >  >    ?
 > >  >    int iel=0;
 > >  >    ?
 > >  >    PtrF <EL> el01 = (EL*) iel; 	//line 105
 > > 
 > > Don't do this.  The answer to your problem is to not cast a pointer to
 > > an integer.  If you can explain why you want to do such casting, we'll
 > > be able to tell you how to avoid it.
 > > 

 > I did not write the program. Structure, which I gave last time, is
 > such that enables communication between Fortran and C++ on a way
 > that has historical reasons. So the structure is a fact, which
 > can't be changed.

Ha, right.  FORTRAN: that explains the weirdness.

 > There are no problems if the program is compiled on 32-bit
 > environment, but on 64-bit environment I get casting warnings.

 > The purpose of casting is to initialise arrays used by C++ and
 > Fortran. For test I have made a small program with that
 > structure. I found out (based also on info from this forum) that if
 > I use long instead of int, I do not have warnings any more. This
 > seems to be a solution, which I have not implemented yet.

Well, if this data structure is shared with FORTRAN you'll have to do
something similar on the FORTRAN side.  It'll be a different type:
INTEGER*8 or somesuch.  I'm not a FORTRAN programmer.

But yes, long will work on all gcc targets I'm aware of.

Andrew.