On 5/6/24 12:09 PM, David Faust wrote:
On 5/6/24 11:32 AM, Yonghong Song wrote:
On 5/3/24 5:32 AM, Jose E. Marchesi wrote:
This patch modifies selftests/bpf/Makefile to pass -Wno-attributes to
GCC. This is because of the following attributes which are ignored:
- btf_decl_tag
- btf_type_tag
There are many of these. At the moment none of these are
recognized/handled by gcc-bpf.
We are aware that btf_decl_tag is necessary for some of the
selftest harness to communicate test failure/success. Support for
it is in progress in GCC upstream:
https://gcc.gnu.org/pipermail/gcc-patches/2024-May/650482.html
However, the GCC master branch is not yet open, so the series
above (currently under review upstream) wont be able to make it
there until 14.1 gets released, probably mid next week.
Thanks. It would be great if the patch can be merged soon.
A small note here - the above series does not itself contain the patch
to support decl_tag, it is just some prerequisite structural changes and
the option to prune BTF before emission similar to clang to slim the
selftest (and other) program sizes down.
The patch to enable decl_tag for functions in BTF, enough for the
selftest harness, can go up after that. But, it will require some
approvals from the C front-end maintainers, since it is a new attribute,
so it may take longer, and may be contentious.
Thanks for the update! Let me know if I can help from llvm/kernel/bpf
perspective.
As for btf_type_tag, more extensive work will be needed in GCC
upstream to support it in both BTF and DWARF. We have a WIP big
patch for that, but that is not needed to compile/build the
selftests.
Thanks. Eduard has implemented in llvm with agreed new format. Since
the old phabricator becomes readonly, he will upstream the original
patch to llvm-project soon.
[...]
