Allow unknown fields when parsing P4Info files

[jafingerhut]

No description provided.

[jafingerhut]

This PR is the same as #4129 except it is up to date with latest main version of p4c.

[jafingerhut]

I have checked the protobuf source repo here https://github.com/protocolbuffers/protobuf looking through several versions of it to see which versions support the allow_unknown_field optional parameter to the Python method google.protobuf.text_format.Merge, and which do not.

I believe that this optional parameter was added in v3.8.0 of Protobuf. I would guess that the reason this p4c CI test:

• test-p4c / test-ubuntu20 (Unity ON)

is failing, is because it is using a version of Protobuf older than that, but I am not sure where to verify that guess.

[fruffy]

I have checked the protobuf source repo here https://github.com/protocolbuffers/protobuf looking through several versions of it to see which versions support the allow_unknown_field optional parameter to the Python method google.protobuf.text_format.Merge, and which do not.

I believe that this optional parameter was added in v3.8.0 of Protobuf. I would guess that the reason this p4c CI test:

* test-p4c / test-ubuntu20 (Unity ON)

is failing, is because it is using a version of Protobuf older than that, but I am not sure where to verify that guess.

What happens if you remove this check here? It might be that the preinstalled Protobuf version is too old.

[fruffy]

Seems like it works. Would be great to add these dependencies to the requirements.txt file. But this might break Ubuntu 18.04, which we still run as a nightly build.

[jafingerhut]

Seems like it works. Would be great to add these dependencies to the requirements.txt file. But this might break Ubuntu 18.04, which we still run as a nightly build.

Commit 4 of this PR I added the versions of protobuf, grpcio and googleapis-common-protos packages to requirements.txt. We will see soon from CI tests what happens.

[jafingerhut]

@fruffy Where can one find the results of nightly Ubuntu 18.04 builds?

[fruffy]

@fruffy Where can one find the results of nightly Ubuntu 18.04 builds?

https://github.com/p4lang/p4c/actions/workflows/ci-ubuntu-18-nightly.yml

The problem is that they will not run on this PR. I think we can change that.

[jafingerhut]

Or if we want to take a chance, I can merge this PR and then we'll see tomorrow what the nightly results are, and backo out the requirements.txt changes if they mess those up? I think I will try that now.

[fruffy]

https://github.com/p4lang/p4c/actions/runs/7619068359/job/20753493581

It looks like Ubuntu 18 does not support anything over Protobuf 3.19.

[jafingerhut]

@fruffy Any preference on what to do next? e.g. back out the changes to the requirements.txt file?

[fruffy]

I created #4348 to run optional CI runs by adding tags. I can try to see whether downgrade to 3.19 can help. Otherwise, we can only remove it from the file since requirements.txt doesn't support optional installation.