[clang] [llvm] [Sema] Implement support for -Wformat-signedness (PR #74440)

[Karl-Johan Karlsson via cfe-commits]

karka228 wrote:

> Sorry for the delayed response, this fell off my radar (thanks @Endilll for mentioning this after meeting with @hazohelet!).

No problem. As I wrote above I work in an out of tree backend and I have already implemented this in our downstream repo. Our customer that requested this already have this feature. To me this is not at all urgent.

> This would be novel but might not be a terrible approach. I'm not convinced that #3 is a particularly good design (and #6 doesn't seem critical to me either), but I think modifying tablegen to improve support here would be a heavy lift for little benefit. I'd say let's try that approach and see how we like it, and go from there. WDYT?

Sounds good. I think what is currently implemented in this pull request use @hazohelet  idea with the dummy warning. As this was started in December I think I have to rebase this onto a more recent main branch.

I will look through the code in the pull request (as it was a while ago since I looked at this) and do the rebase ...


https://github.com/llvm/llvm-project/pull/74440