[llvm-dev] [RFC] Deprecating the legacy pass manager for the optimization pipeline

[Fangrui Song via llvm-dev]

On 2021-08-24, Arthur Eubanks via llvm-dev wrote:
>The new pass manager has been on by default since the 13 branch. Now that
>we've branched for 14, I'd like to start the process of deprecating and
>removing legacy pass manager support for the optimization pipeline. This
>includes clang, opt, and lld LTO support.
>
>Note that this doesn't apply to the codegen pipeline since there's no new
>pass manager support for that yet.
>
>Are there any objections?

"deprecating" and 'removing" are different.

For 14.0.0, do you plan that -DLLVM_ENABLE_NEW_PASS_MANAGER=off will
give a warning or will be completely unsupported?