"Hamilton, Ian" <Ian.Hamilton@xxxxxxxxxxxxx> writes:
> Hi there
>
> Here is a test program to illustrate a problem in some code
> I have inherited:
>
> #include <stdio.h>
>
> const int array1[5]=
> {
> 1,
> 2,
> 3,
> 4,
> 5
> };
>
> const int array2[5]=
> {
> 1,
> array2[0] + 1,
> array2[1] + 1,
> array2[2] + 1,
> array2[3] + 1,
> };
>
> int main()
> {
> printf ("Array values:\n\n");
> printf("array1 array2\n");
>
> printf(" %i %i\n", array1[0], array2[0]);
> printf(" %i %i\n", array1[1], array2[1]);
> printf(" %i %i\n", array1[2], array2[2]);
> printf(" %i %i\n", array1[3], array2[3]);
> printf(" %i %i\n", array1[4], array2[4]);
> }
>
>
> If I build and run this on a Sun/Sparc/Solaris system using
> gcc version 2.95.2, I get the following output:
>
> Array values:
>
> array1 array2
> 1 1
> 2 2
> 3 3
> 4 4
> 5 5
>
>
> However, if I use gcc version 3.3.2, I get this output:
>
> Array values:
>
> array1 array2
> 1 1
> 2 1
> 3 1
> 4 1
> 5 1
FWIW, on i386-freebsd5.2, gcc 3.4 release cannidate gives the same
output as gcc 2.95.2 . So I think this bug is fixed in 3.4 (but it is
still present in 3.3.3). I can't find the bug report, however.
[snip]
> My question is whether this sort of self-reference is allowed by
> the C and/or C++ standards. In other words, is this a compiler bug,
> or a bug in the above code?
I am nearly certain C++ allows this. I can't find anything in 8.5.1
that disallows it.
