Re: [PATCH] libperf test: Silence printf flag warning

From: Rob Herring
Date: Tue May 04 2021 - 21:53:57 EST


On Tue, May 4, 2021 at 2:43 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> __u64 maybe an unsigned long, it may also differ from the format
> expected by PRIu64. Add a cast to silence the warning:
>
> tools/lib/perf/tests/test-evsel.c:176:33: error: format specifies type 'unsigned long long' but the argument has type 'unsigned long' [-Werror,-Wformat]
> __T_VERBOSE("count = %llu\n", end - start);
> ~~~~ ^~~~~~~~~~~
> %lu

Which arch/compiler did you hit this? LLVM? Would have been 64-bit
presumably. I'm wondering how I didn't...

> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/lib/perf/tests/test-evsel.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/perf/tests/test-evsel.c b/tools/lib/perf/tests/test-evsel.c
> index 288b5feaefe2..558097bbbfd0 100644
> --- a/tools/lib/perf/tests/test-evsel.c
> +++ b/tools/lib/perf/tests/test-evsel.c
> @@ -173,7 +173,7 @@ static int test_stat_user_read(int event)
>
> __T("invalid counter data", (end - start) > last);
> last = end - start;
> - __T_VERBOSE("count = %llu\n", end - start);
> + __T_VERBOSE("count = %llu\n", (unsigned long long)(end - start));

I think I'd either change end/start to uint64_t which matches the
count struct and use PRIu64, or change them to unsigned long long.

> }
>
> perf_evsel__munmap(evsel);
> --
> 2.31.1.607.g51e8a6a459-goog
>