[clang] [clang-tools-extra] [clang][analyzer] Add ReportInC99AndEarlier option to DeprecatedOrUnsafeBuf… (PR #168704)

[Endre Fülöp via cfe-commits]

gamesh411 wrote:

I have implemented part of the RFC discussion relevant to this checker according to the RFC discussion (https://discourse.llvm.org/t/rfc-report-modes-for-unsafe-function-reporting/88971)
What do you think @steakhal?

https://github.com/llvm/llvm-project/pull/168704