If you're using the open-source p4c compiler, the default target is (still) bmv2. You need --target tofino to compile for tofino.

Thanks, Chris! There is still a confusion going on in this repo with regards to the compiler name.

For whatever reason someone decided to name it p4c (so that in $SDE_INSTALL/bin there is a file named p4c and not bf-p4c, even though in reality it is the Python wrapper developed at Barefoot/Intel with the actual compiler being p4c-barefoot, of course.

As a result doing what I said (p4c my_program.p4) does work.

I am not sure who decided to change the name and who should be persuaded to change it back, but your comment clearly indicates the need.

I filed a case for that (#50 ) quite a while ago. Maybe you can weigh in.

p4c is the generic driver program that figures out which backend to run, based on the --target option. You can configure the default target to use if there is no --target option to anything, but different builds do it differently.

IMO we should encourage people to ALWAYS use the --target option -- that way things "just work" regardless of how it was installed. Specifying it when it is not needed (because that target was set up as the default) is never harmful.

@ChrisDodd,

Thank you. I see that the main driver itself (bf-p4c in the SDE and p4c in the open-p4studio) is the same. Also, in both cases the directory $SDE_INSTALL/share/p4c/p4c_src` contains only Tofino-specific files and does not contain the plugins for the other backends.

That explains why the command line above works and confirms my assertion that p4c included in open-p4studio is not exactly the "stock" one. I think that it is po

As for your second point, I do not think that people should be supplying arguments for which there are reasonable defaults. Yes, the option os there, but for the simple things people should be typing very simple commands.

We do not routinely specify -m parameter(s) when compiling simple using GCC, do we? In embedded world people often use things like p4c-gcc, etc. so allowing people to do p4c myprog.p4 (when they are clearly working in the Tofino environment) or bf-p4c myprog.p4 isn't such a bad thing, is it?

Chris, not trying to ignore your comments, but FYI I am approving this PR as it is right now, now that we figured out why some of my typo-level comments were not visible to others before, and Vladimir has fixed them with a commit a few minutes ago as I write this.

My main concern is that the documentation is accurate for people installing the open-p4studio code, and it appears to me these instructions are accurate for that. I have not personally tried installing only open source p4c and compiling for Tofino, and you may be correct that using --target tofino is required and/or a good idea in that situation, but that is definitely not required if you install open-p4studio.