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Re: [C PATCH] field_decl_cmp
On Fri, 15 Sep 2017, Nathan Sidwell wrote:
> On 09/12/2017 12:48 PM, Joseph Myers wrote:
>
> > I'd be concerned about the possibility of a qsort implementation that
> > calls the comparison function with two pointers to the same object (as far
> > as I can tell, it's valid for qsort to do that). That is, I think you
> > need to check for the two DECLs being the same DECL, before asserting
> > their names are different.
>
> I suppose we can drop the assert. That does leave it returning +1 in the case
> you're concerned about, but I don't really see the need to tell such a stupid
> qsort that the things are unordered.
I don't know what such a qsort would do if such a case returned 1; my
presumption is that all our comparison functions ought to return 0 when
two objects are equal, even if that can only be if they are the same
object. It's OK with a return of 0 if x == y (or if DECL_NAME (x) ==
DECL_NAME (y), whichever you think appropriate).
--
Joseph S. Myers
joseph@codesourcery.com