Suggestions on building simple_switch_grpc with bazel 8.5.0

[Vineet1101]

Hi everyone,

I am currently working on adding support for Bazel 8.5.0 to BMv2's simple_switch_grpc. I have already created some basic Bazel build files and dependencies, and the initial setup is working.

Before moving further, I would like to confirm the correct approach for handling PI library dependencies.

The PI submodule (PI/) expects the PI headers to be installed system-wide (e.g., PI/pi.h, PI/target/pi_imp.h, PI/p4info.h). In the current CMake build, these come from a pre-installed PI system library.

For Bazel, I see two possible approaches:

1. Build BMv2’s PI implementation directly from the local PI submodule sources
This would involve compiling the .cpp files under PI/src/.
However, this would only cover the BMv2 PI implementation, and would not include the upstream PI framework libraries such as:

• pifeproto
• pigrpcserver
• pi
• pip4info

which are used by some tests.

2. Import the full p4lang/PI repository as a Bazel dependency
This could be done using bazel_dep or git_override in MODULE.bazel, which would allow building the PI framework libraries as well.

However, the upstream PI repository currently uses WORKSPACE-based Bazel, not bzlmod, so this might require some compatibility adjustments.

Both approach have their own pros and cons, so can someone please advise which approach would be preferred for integrating Bazel support into BMv2?

[Vineet1101]

@jafingerhut @fruffy can you guide me on this

[fruffy]

@smolkaj @qobilidop

[qobilidop]

@matthewtlam

[matthewtlam]

@Vineet1101, we would recommend that you go with option 2. The goal is to build BMv2 with Bazel v8. There are ways to get a repository that uses Bazel 6/7 to build in Bazel v8 IIRC. You should try to look into different ways to do that. A pointer is to use http_archive to wrap the legacy dependency

cc: @qobilidop

[smolkaj]

Are you willing to use an AI coding agent?

Claude Code should be able to add Bzlmod and Bazel 8 support for p4lang/PI autonomously, in my experience. The build rules look simple. Tell the agent to bump the dependencies to their latest versions, that should help.

[Vineet1101]

Are you willing to use an AI coding agent?

Claude Code should be able to add Bzlmod and Bazel 8 support for p4lang/PI autonomously, in my experience. The build rules look simple. Tell the agent to bump the dependencies to their latest versions, that should help.

already doing that :)