efriedma added inline comments.
================ Comment at: include/clang/Basic/DiagnosticSemaKinds.td:6031 InGroup<PointerArith>; +def ext_gnu_null_ptr_arith : Extension< + "arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension">, ---------------- andrew.w.kaylor wrote: > efriedma wrote: > > andrew.w.kaylor wrote: > > > efriedma wrote: > > > > "extension" isn't really right here; this shouldn't be an error in > > > > -pedantic-errors mode. Probably best to just stick this into the > > > > NullPointerArithmetic, like the other new warning. > > > So how should a word the warning? Just this: > > > > > > "arithmetic on a null pointer treated as a cast from integer to pointer"? > > That wasn't what I meant; the current wording is fine. I meant this should > > be something like `def warn_gnu_null_ptr_arith : Warning<`. > OK. I think I understand the behavior you wanted. I just thought maybe the > current wording might be technically incorrect. I wasn't sure how precisely > defined we consider "extension" to be in this context. The part that makes this a little weird is that unlike most extensions, this code is already well-formed. It's an extension because we're guaranteeing runtime behavior for a construct which has undefined behavior at runtime according to the standard. (This is in contrast to "implementation-defined" behaviors, which are the gaps in the standard we're allowed to fill in as we see fit.) Given that, I think calling it a "GNU extension" in the text is fine. https://reviews.llvm.org/D37042 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
