Changing compiler from p4app.json

[danisrcnl]

I'm not sure this is a true issue, but as long as there's no documentation online I'd rather try to ask it to you. I need to compile using p4c-bm2-ss compiler to use my custom externs. I was capable of doing it with a previous version of p4utils (the one in the p4lang pre-built vm) by setting the "compiler" field in p4app.json file. But now that the "compiler_module" field should be filled, I'm not so sure I can force the usage of that compiler as no python class has been implemented for it in p4utils/utils/compiler subfolder.

Thank you in advance.

[edgar-costa]

We do have the P4C class at https://github.com/nsg-ethz/p4-utils/blob/master/p4utils/utils/compiler.py

You should check where the P4C class is being used in the code and how you can change the p4_bin and opts to use your custom compiler.

If you are using the python interface, see examples that use network.py you can set the compiler options with : https://github.com/nsg-ethz/p4-utils/blob/master/p4utils/mininetlib/network_API.py#L950

Otherwise, you can use the compiler_module option to add your compiler. You can see the parsing code here:
https://github.com/nsg-ethz/p4-utils/blob/master/p4utils/p4run.py#L277

[edgar-costa]

For the time being, if you do not manage to navigate the code you can simply modify this line (in your local code):

https://github.com/nsg-ethz/p4-utils/blob/master/p4utils/utils/compiler.py#L35

And replace p4c for p4c-bm2-ss, in the case you have different default compiler options than '--target bmv2 --arch v1model --std p4-16' you should also try to modify that.

I realized that with the p4app.json changing the compiler it has become a bit harder than before. When we find time we will try to make it simpler.