rjmccall added a comment. In https://reviews.llvm.org/D44883#1048081, @lebedev.ri wrote:
> In https://reviews.llvm.org/D44883#1048010, @rjmccall wrote: > > > I'm not sure you really need to put these in their own warning sub-group > > just because they're user-defined operators. That's especially true > > because it appears we already have divisions in the warning group based on > > the form of the l-value; we don't want this to go combinatorial. > > > Several reasons: > > - The initial `-Wself-assign` was intentionally implemented not to warn on > overloaded operators. > https://github.com/llvm-mirror/clang/commit/9f7a6eeee441bcbb1b17208cb3abd65a0017525a#diff-e0deb7b32f28507a3044a6bf9a63b515R31 > (https://reviews.llvm.org/rL122804) That's interesting. Maybe Chandler remembers the rationale for that? > - While it is an obvious bug when self-operation happens with builtin > operators, i'm less certain of that with overloaded operators. It's certainly more plausible that the programmer has a good reason to self-assign with a user-defined operator, yeah. > If you happen to be routinely using self-assignment via oh-so-very-special > overloaded operator=, and you don't like to have this > diagnostic, you could just disable it, and not loose the coverage of the > `-Wself-assign-builtin`. > If it is all in one group, you can't do that... True. > - Based on previous expirience, separate diag groups are good, see e.g > https://reviews.llvm.org/D37620, https://reviews.llvm.org/D37629 > - I'm failing to find the original quote, but i **think** @rsmith said > something along the "diag groups are cheap, use them". But i may as well be > mis-remembering/having false memories here, sorry. Yeah, like I said, I'm just worried about the usability of having multiple dimensions of warning group here. Like, do we need both -Wself-assign-field-builtin and -Wself-assign-field-overloaded? Because I do think we should warn on field self-assignments for user-defined operators. I think the term ought to be "user-defined" rather than "overloaded", by the way. In a sense, these operators aren't really any more overloaded than the builtin operators (at least, not necessarily so) — C++ even formalizes the builtin operators as being a large family of overloads. And the reason we want to treat them specially is that they have user-provided definitions that might be doing special things, not because of anything to do with name resolution. > TLDR: if you insist, sure, i can just cram it into the already-existing > `-Wself-assign`, > but i believe that is the opposite of what should be done, and is against > the way it was done previously. I'm not going to insist. But I would like to hear if Chandler remembers why his patch didn't warn about user-defined operators. Repository: rC Clang https://reviews.llvm.org/D44883 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
