== Quote from Daniel Gibson (metalcae...@gmail.com)'s article
> Leandro Lucarella schrieb:
> > Iain Buclaw, el 21 de octubre a las 11:54 me escribiste:
> >> A few standard library functions, such as 'abort' and 'exit', cannot
> >> return.
> >> However there is no way in DMD to let the compiler know about this.
> >> Currently in D2, you must either have a 'return' or 'assert(0)' statement
> >> at
> >> the end of a function body. It would be nice however if you can give hints
> >> to
> >> the compiler to let it know that a function is never going to return.
> >>
> >> Example:
> >>
> >> @noreturn void fatal()
> >> {
> >> print("Error");
> >> exit(1);
> >> }
> >>
> >> The 'noreturn' keyword would tell the compiler that 'fatal' cannot return,
> >> and
> >> can then optimise without regard to what would happen if 'fatal' ever did
> >> return. This should also allow fatal to be used instead of a return or
> >> assert
> >> statement.
> >>
> >> Example:
> >>
> >> int mycheck(int x)
> >> {
> >> if (x > 1)
> >> return OK;
> >> fatal();
> >> }
> >>
> >>
> >> Thoughts?
> >
> > You want to include in the language what you can do (or at least could)
> > do in GDC using:
> >
> > pragma(GNU_attribute, noreturn)) void fatal()
> > {
> > print("Error");
> > exit(1);
> > }
> >
> > ?
> >
> Obviously he wants a portable way to do this that will work on any up-to-date
> D2
compiler.. doesn't
> make much sense to have a gdc-only solution that makes code incompatible with
dmd (and possibly
> other compilers). Of course one may use version(GDC) or something like that to
ensure compatibility,
> but that's just ugly.
> Cheers,
> - Daniel
The GNU_attribute pragmas are just hints to the GCC backend; very limited in
what
they do; don't really thrive very well in D's environment.
Take for example:
pragma (GNU_attribute, vector_size(16)) typedef int MyInt;
And you have a MyInt data type that is 16bytes wide, but D will still report
that
it is 4, and you can't use or assign anything to it either (else we'll ICE). I
guess it is a WIP feature that got left behind, I could have a look at it
improving it sometime, but I haven't really seen any benefits in reviving it
though...
