jyknight added a comment. In https://reviews.llvm.org/D42933#1090384, @jfb wrote:
> In https://reviews.llvm.org/D42933#1090286, @smeenai wrote: > > > I'd be fine with adding an option to relax the printf checking if the size > > and alignment of the specifier and the actual type match, even if the types > > themselves differ (`-Wformat-relaxed` or something similar), so that you'd > > still get warnings on cases where the specifier mismatch could cause > > runtime issues. > > > What are the cases that you're worried about? The only ones I'm trying to > capture here are `NSInteger` with `%zd` and `NSUInteger` with `%zu`, are > there others? > > > I think that would be preferable to special-casing the Apple types. > > If there are more that should be captured and a similar point solution > doesn't apply, agreed. However I'd like to understand if we agree on the > guarantees that the platform offers for the two specific cases I'm targeting. I also think that special casing these two specifiers doesn't make sense. The problem is a general issue -- and one I've often found irritating. This exact same situation comes up all the time in non-Darwin contexts too. E.g. one I find particularly annoying is "%lld" vs "%ld" in printf. Some 64-bit platforms define e.g. `int64_t` as `long long`, and others as `long`. Although both types are size 8, align 8, and mean exactly the same thing, they are still distinct. And so, users write code like `int64_t x = 0; printf("%ld", x);`...which then emits warnings on the platform that defines int64_t as a `long long`. Obviously, the code _could_ be using `PRId64` instead...but it often doesn't. So it'd sure be nice if you could restrict the warning to only warn about actual problems, and suppress these superficially-incompatible-but-not-really warnings. So, +1 from me for the general-purpose `-Wformat-relaxed` flag (or whatever other flag name is appropriate). Repository: rC Clang https://reviews.llvm.org/D42933 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
