On Thu, Apr 23, 2009 at 1:38 PM, Denis Onischenko
> <denis.onische...@gmail.com> wrote:
> > The minimal code example is following:
> >
> >
> > extern unsigned int __invalid_size_argument;
> > #define TYPECHECK(t) ( sizeof(t) == sizeof(t[1]) ? sizeof(t) :
> > __invalid_size_argument )
> >
> > static int arr[] = {
> > [TYPECHECK(int)] = 0,
> > };
> >
> > int main()
> > {
> > return 0;
> > }
> >
> >
> > command line is: gcc test.c
> >
> > GCC 4.5.0 revision 146607 compiles this code with following errors:
> > test.c:5: error: nonconstant array index in initializer
> > test.c:5: error: (near initialization for 'arr')
> >
> > released GCC 4.4.0 compiles without any errors
On Thu, Apr 23, 2009 at 04:58:17PM -0700, James Dennett wrote:
> A diagnostic is required in standards-conforming modes, as
> TYPECHECK(int) is not an "integral constant expression" (because it
> includes a non-constant in a potentially-evaluated operand).
But there are cases where we avoid issuing such a diagnostic by
default, without flags such as -pedantic or calling out a specific
language standard.
The compiler is not supposed to be pedantic by default. A standards
document saying that a diagnostic is required should not be the end
of the story, especially when we're talking about important, widely
used code bases.
