aaron.ballman added a comment. In D126324#3537282 <https://reviews.llvm.org/D126324#3537282>, @jyknight wrote:
> In D126324#3536785 <https://reviews.llvm.org/D126324#3536785>, @aaron.ballman > wrote: > >> The changes so far look sensible, but I think we should add some more tests >> for a few situations. 1) Using a const weak symbol as a valid initializer >> should be diagnosed (with a warning? with an error?) so users are alerted to >> the behavioral quirks. > > I don't feel this is really necessary. Why? My thinking is: it's invalid to initialize a file scope variable in C from something other than a constant expression. These are not constant expressions. Why should the initialization work silently and maybe do something wrong? >> 2. Using a const weak symbol in a constant expression context should >> probably be an error, right? e.g., > > That's already the case (except, using a VLA is not an error in either > language mode). Clang previously _only_ treated weak symbols as > compile-time-known in the backend; the frontend has treated it as an > non-constant-evaluable variable for ages, and that behavior is unchanged by > this patch. Ah, okay, then it sounds like we already have the behavior I was hoping for, great. >> Also, this definitely could use a release note so users know about the >> behavioral change. >> >> Do you have any ideas on how much code this change is expected to break? (Is >> it sufficient enough that we want to have an explicit deprecation period of >> the existing behavior before we switch to the new behavior?) > > Because it's only changing the optimizer behavior not the frontend constant > evaluator, I think it's pretty safe (which is also why I'm OK with it). +1 Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D126324/new/ https://reviews.llvm.org/D126324 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
