aaron.ballman added a comment. In D123627#3707789 <https://reviews.llvm.org/D123627#3707789>, @aaron.ballman wrote:
> In D123627#3707635 <https://reviews.llvm.org/D123627#3707635>, @efriedma > wrote: > >> If the declaration we're redeclaring is a builtin, should the diagnostic be >> in the "-Wincompatible-library-redeclaration" warning group? With this >> patch, we treat redefinitions of builtins without a prototype differently >> from redefinitions with a prototype, for example: >> >> void acos() {} // error >> void acos(void) {} // warning >> >> Just ran into some code in Android which is using the first form. > > Er, I keep going back and forth on it. My initial inclination is that this is > closing a hole where we would incorrectly decide that these function > signatures are compatible enough to merge together when that's not the case, > so an error is appropriate. But the same can be said for redeclaring a > builtin with an incorrect prototype rather than declaring it without any > prototype. Given that these builtins are declared for the user automagically, > I think I come down on this being a case we'd rather warn instead of err. > It'd be weird to allow the user to define `void printf(void) {}` but not > `void printf();` (except in C2x mode). > > If we make a change here, I think it'd be good to get it done for Clang 15. > I'm not certain I've got the bandwidth to make this change in that timeframe > though (I can hopefully start on this sometime this week, but I have prior > commitments with deadlines that take priority). I filed https://reviews.llvm.org/D131499 for this. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D123627/new/ https://reviews.llvm.org/D123627 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
