selftests/bpf: Fix "expression result unused" warnings with icecc #5853
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Upstream branch: 98857d1 |
icecc is a compiler wrapper that distributes compile jobs over a build farm [1]. It works by sending toolchain binaries and preprocessed source code to remote machines. Unfortunately using it with BPF selftests causes build failures due to a clang bug [2]. The problem is that clang suppresses the -Wunused-value warning if the unused expression comes from a macro expansion. Since icecc compiles preprocessed source code, this information is not available. This leads to -Wunused-value false positives. obj_new_no_struct() and obj_new_acq() use the bpf_obj_new() macro and discard the result. arena_spin_lock_slowpath() uses two macros that produce values and ignores the results. Add (void) casts to explicitly indicate that this is intentional and suppress the warning. An alternative solution is to change the macros to not produce values. This would work today for the arena_spin_lock_slowpath() issue, but in the future there may appear users who need them. Another potential solution is to replace these macros with functions. Unfortunately this would not work, because these macros work with unknown types and control flow. [1] https://github.com/icecc/icecream [2] llvm/llvm-project#142614 Signed-off-by: Ilya Leoshkevich <[email protected]> Acked-by: Yonghong Song <[email protected]>
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Upstream branch: 98857d1 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=996738 irrelevant now. Closing PR. |
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Pull request for series with
subject: selftests/bpf: Fix "expression result unused" warnings with icecc
version: 4
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=996738