[Mlir-commits] [llvm] [mlir] [CMake] Add dependent project mode for Flang's MLIR (PR #221724)

[Mehdi Amini]

joker-eph wrote:

> However, that would mean if someone was just doing `LLVM_ENABLE_PROJECTS=flang`, they would only build `flang` binaries with `ninja all`, which is a change, but honestly one that I think is probably closer to what the user intended.

To be clear: this is exactly the effect that this patch is achieving!

> My first thought was that we could just make it policy that if a project is in `${LLVM_ENABLE_PROJECTS}` and not in `$CACHE{LLVM_ENABLE_PROJECTS}` then we can just do this implicitly without the new variable. 

It's an interesting to use ` $CACHE{LLVM_ENABLE_PROJECTS} `, I didn't think of that. I updated the current patch to do just this instead of introducing a new `LLVM_DEPENDENCY_ONLY` variable. PTAL!

https://github.com/llvm/llvm-project/pull/221724