aaron.ballman added a comment. In D122983#3454632 <https://reviews.llvm.org/D122983#3454632>, @rsmith wrote:
> In D122983#3454508 <https://reviews.llvm.org/D122983#3454508>, @aaron.ballman > wrote: > >> In D122983#3454494 <https://reviews.llvm.org/D122983#3454494>, @jyknight >> wrote: >> >>> In D122983#3454406 <https://reviews.llvm.org/D122983#3454406>, >>> @aaron.ballman wrote: >>> >>>> Out of curiosity -- do you think we should remove the `DefaultIgnore` in >>>> C89 mode so that we warn by default there (perhaps as a follow up)? Also, >>>> I presume you expect `diag::ext_implicit_lib_function_decl` to behave the >>>> same way (warn in C89, warn-as-err in C99 and up) as part of this patch? > > I think it would make sense to include the C89 warning in `-Wc99-compat`, but > I agree with James that it doesn't seem worthwhile to enable it by default. Ah, that's a good idea for a follow-up, thanks! >> I feel a bit more strongly that implicit builtins should be handled the same >> as other implicit functions (in terms of `DefaultError` behavior), unless >> there's some scenarios I'm not thinking of. > > I'm not sure which case you mean by "implicit builtins". Two cases seem > relevant: > > - `ext_implicit_lib_function_decl`, for things like using `strlen` without > including its header; I think that should behave the same as using any other > undeclared function name (error by default in C99 onwards, error with no > warning flag in C2x onwards even though we would synthesize the correct > prototype). Great, this was the one I was talking about, and that's the approach I'd like to take with it. I'll have that in the next revision. > - `warn_builtin_unknown`, for things like using > `__builtin_no_such_builtin_exists()` (a function name starting `__builtin_` > that is not a known builtin and hasn't been declared), which is currently a > warning-as-error in all language modes; I think that should stay an error by > default in all modes, and I'd be happy to see it turn into a harder error > (with no warning flag), whether that happens only in C2x onwards, in C99 > onwards, or in all modes. Okay, I hadn't touched that one because it was already default error. I'm happy to try to turn it into a hard error in a followup patch. Thanks for the feedback! CHANGES SINCE LAST ACTION https://reviews.llvm.org/D122983/new/ https://reviews.llvm.org/D122983 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
