mikecrowe added inline comments.
================
Comment at:
clang-tools-extra/docs/clang-tidy/checks/modernize/use-std-print.rst:79
+
+.. option:: StrictMode
+
----------------
mikecrowe wrote:
> It turns out that absl::PrintF and absl::FPrintF work like std::format,
> fmt::printf, etc. and use the signedness of the argument rather than the
> signedness indicated in the format string to determine how to format the
> number. In other words:
> `unsigned int ui = 0xffffffff; absl::PrintF("%d\n", ui);` yields `4294967295`
> (see https://godbolt.org/z/dYcbehxP9 ), so the casts that StrictMode adds
> would change the behaviour of the converted code.
>
> I can think of several ways around this:
>
> 1. Update the documentation to explain this, recommending not to use
> StrictMode when converting Abseil functions.
>
> 2. Remove built-in support for Abseil functions from this check. Anyone
> wishing to convert them can do so via the customisation features, and can
> choose not to use StrictMode. (This could be documented here.)
>
> 3. Teach the code to recognise whether the arguments is being passed as a
> C-style variable argument list or as fully-typed arguments to a templated
> function and make StrictMode only add the casts for the former. (I've not
> investigated how feasible this is.)
>
> 4. Treat the known Abseil functions in this check differently by name and
> disable the casting behaviour. This means that conversion from fmt::printf
> via the customisation mechanism wouldn't automatically get that behaviour.
>
> As someone who doesn't use Abseil I'm inclined towards option 2, with the
> possibility of implementing option 3 in a separate commit later. I'm not
> particularly keen on the other two options.
It turns out that option 3 was easier to implement than I expected, so I've
implemented it in the latest version.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D149280/new/
https://reviews.llvm.org/D149280
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
