[Mlir-commits] [mlir] [mlir][cmake] Enable -Wundef. (PR #84011)

[Ingo Müller]

ingomueller-net wrote:

After this and all related PRs have landed and the dust has settled, we may consider turning this into `-Werror=undef`.

Also note that this seems more challenging to do for the Bazel builds because some of the macros are not defined in [its version of `mlir-config.h`](https://github.com/llvm/llvm-project/blob/main/utils/bazel/llvm-project-overlay/llvm/include/llvm/Config/llvm-config.h) and quite some machinery seems to be missing to change that.

https://github.com/llvm/llvm-project/pull/84011