Hi, I'm trying to use Gentoo's bpf-toolchain - basically just gcc built for the BPF target - to build the CO-RE support in bpftool, in order to provide an alternative to clang. This currently fails because the feature detection relies on a comment in the generated BPF assembly, which gcc does not seem to generate. While I'm using the Github mirror for bpftool, the same check is being done in the kernel build, so it affects both. Our tracker bug with full output etc. is: https://bugs.gentoo.org/943113 Basically the problem boils down to: .long 16777248 # 0x1000020 .long 9 # BTF_KIND_VAR(id = 3) .long 234881024 # 0xe000000 generated by clang (19.1.3) vs. .4byte 0x1000020 .4byte 0x9 .4byte 0xe000000 generated by gcc (14.2.0). As the values themselves are correct, the problem is really just the missing debug information in gcc's output. So far I've tried every option I could find, but to no avail. I have no idea whether this is because I'm holding it wrong, gcc cannot do it for the bpf target (yet?) or anything else. Does anybody know how I can convince gcc to generate symbol comments? Alternatively can we find a better way to verify the generated output instead of grepping for a comment? This is not really a bug, but IMHO having an alternative toolchain to build BPF seems like a good idea in general. Gentoo's bpf-toolchain package was initially made to build dtrace, and seems to be working fine so far. Thanks for any suggestions! cheers Holger
