The discussion about MAYBE_UNUSED over in[1] made me wonder how it was used in practice. This series cleans up a few spots where I think it is being misused. [1] https://lore.kernel.org/git/xmqqseunxtks.fsf_-_@gitster.g/ The remaining grep hits are: - fsmonitor has a few functions with sometimes-unused parameters based on conditional compilation (try_to_run_foreground_daemon() and check_for_incompatible()). This is a good use of MAYBE_UNUSED. - builtin/gc.c's check_crontab_process(). The whole function is marked as MAYBE_UNUSED here, which is a little funny. It's because is_crontab_available() may or may not call us based on __APPLE__. Should we conditionally define the function, too, in that case? It would mean repeating the #ifdef. Alternatively, we could define it like this: #ifdef __APPLE__ static int check_crontab_process(const char *cmd UNUSED) { return 0; } #else static int check_crontab_process(const char *cmd UNUSED) { [...the real function...] } #endif But I think we're getting into "well, this is how I would have written it" territory, and it doesn't matter much either way in practice. It's probably better to just leave it alone. - commit-slab marks auto-generated static functions with MAYBE_UNUSED, since it doesn't know which ones actually need to be instantiated. This was the original thing we added MAYBE_UNUSED for. - khash does something similar when auto-generating functions. - test_bitmap_commits() marks a local variable as MAYBE_UNUSED! In fact it's completely unused by the function itself, but the macro expansion of kh_foreach() assigns to it. So we need the variable to exist to pass into the macro, but the compiler warning is triggered on the expanded code. We have kh_foreach_value(), but not kh_foreach_key(), which is what we'd want here. It wouldn't be hard to add it, but the MAYBE_UNUSED here is doing a fine job of suppressing the warning (and presumably an optimizing compiler removes the useless assignment). I prepared this on top of what's queued in jk/unused-parameters (which helps with making sure the annotations are all correct), but it could be applied separately. [1/2]: gc: drop MAYBE_UNUSED annotation from used parameter [2/2]: grep: prefer UNUSED to MAYBE_UNUSED for pcre allocators builtin/gc.c | 2 +- grep.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) -Peff
