On 12/12, Jakub Kicinski wrote: > On Thu, 12 Dec 2019 08:53:22 -0800, Andrii Nakryiko wrote: > > > > > Btw, how hard it would be to do this generation with a new python > > > > > script instead of bpftool? Something along the lines of > > > > > scripts/bpf_helpers_doc.py that parses BTF and spits out this C header > > > > > (shouldn't be that hard to write custom BTF parser in python, right)? > > > > > > > > > > > > > Not impossible, but harder than I'd care to deal with. I certainly > > > > don't want to re-implement a good chunk of ELF and BTF parsing (maps, > > > > progs, in addition to datasec stuff). But "it's hard to use bpftool in > > > > our build system" doesn't seem like good enough reason to do all that. > > > You can replace "our build system" with some other project you care about, > > > like systemd. They'd have the same problem with vendoring in recent enough > > > bpftool or waiting for every distro to do it. And all this work is > > > because you think that doing: > > > > > > my_obj->rodata->my_var = 123; > > > > > > Is easier / more type safe than doing: > > > int *my_var = bpf_object__rodata_lookup(obj, "my_var"); > > > *my_var = 123; > > > > Your arguments are confusing me. Did I say that we shouldn't add this > > type of "dynamic" interface to variables? Or did I say that every > > single BPF application has to adopt skeleton and bpftool? I made no > > such claims and it seems like discussion is just based around where I > > have to apply my time and efforts... You think it's not useful - don't > > integrate bpftool into your build system, simple as that. Skeleton is > > used for selftests, but it's up to maintainers to decide whether to > > keep this, similar to all the BTF decisions. > > Since we have two people suggesting this functionality to be a separate > tool could you please reconsider my arguments from two days ago? > > There absolutely nothing this tool needs from [bpftool], no > JSON needed, no bpffs etc. It can be a separate tool like > libbpf-skel-gen or libbpf-c-skel or something, distributed with libbpf. > That way you can actually soften the backward compat. In case people > become dependent on it they can carry that little tool on their own. [..] > I'd honestly leave the distro packaging problem for people who actually > work on that to complain about. I'm representing a 'Google distro' :-D
