[llvm-dev] GCC 5 and -Wstrict-aliasing in JSON.h

[Kim Gräsman via llvm-dev]

Thanks all for pitching in to help!

On Thu, Aug 9, 2018 at 1:25 PM, Sam McCall <sam.mccall at gmail.com> wrote:
>
> Obviously if there really is something illegal here we should fix it in
> LLVM, but it looks like this warning is a false positive (anyone disagree?)

The little I've read about strict aliasing rules leaves me firmly
incompetent to judge what's valid and not :)

But since both Clang and GCC 6+ are happy with this, it seems
plausible that this would be a false positive.

> Still if there's a simple source-level workaround, or we can suppress the
> warning with a #pragma, I'd be happy to do that. GCC 4.9.3 is a supported
> compiler for LLVM and the more configurations we build cleanly in, the
> better.

I *think* Leslie's warning-disable patch should work even with MSVC
(it should ignore unknown #pragmas, right?). I can't think of a
straight-up code change that would fix this.

Cheers,
- Kim