Hello Karen,
Tuesday, June 17, 2008, 10:38:20 PM, you wrote:
> Hi Ian, I can live with that. My problem was that the addresses
> cannot be correct. In my opinion, the undefined behavior should be
> limited to the value in the address or in some form of error. But to
> let the buggy code execute with addresses that are not accurate is a
> liberty I would hope could have been avoided. It just looks bad. I
> do realize, no one should have a gripe, because the code is buggy to
> begin with. But addresses should always be reported accurately IMHO.
> Of course, I obviously know nothing about compilers. (smiles ;)
I don't see why the addresses are not correct. You should explore
compiler's assembler output to see what's really going there. But
let us check the case here for now.
int main(int argc, char * argv[]) {
const int ic = 0;
const int * cip;
int * ip;
cip = ⁣
ip = (int *)cip;
*ip = 5;
printf("const int ic = %d *cip = %d *ip = %d\n", ic, *cip, *ip);
printf("&ic = %p cip = %p ip = %p\n", &ic, cip, ip);
}
As I see this case, gcc just puts `const int ic` value in register
(its ok since it is declared const and cannot be changed in runtime)
(you can even assume that it's reading it from its place in memory)
and that value from the register gets pushed on the stack for
printf() argument. Of course, it is not modified by your later
assignment because of compiler assumption that consts cannot change.
If you consider that this way, there's no problem in what gcc does
and what addresses/values are returned.
--
Best regards,
Dmitry mailto:[EMAIL PROTECTED]
