Re: [PATCH 1/1] tools: Disable __packed attribute compiler warning due to -Werror=attributes

[Namhyung Kim]

On Wed, Nov 22, 2023 at 8:41 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Namhyung, I had to cherry pick this from perf-tools-next as I noticed it
> was also failing when trying to build perf-tools/tmp.perf-tools + your
> header sync series + Ian's ARM files missing in MANIFEST for the
> detached tarball build.
>
> With these patches I managed to complete 'make -C tools/perf build-test'
> + 'perf test' + my suite of perf build containers.

Hmm.. ok.  I will cherry-pick it to perf-tools.

Thanks,
Namhyung

> ----
>
> Noticed on several perf tools cross build test containers:
>
>   [perfbuilder@five ~]$ grep FAIL ~/dm.log/summary
>     19    10.18 debian:experimental-x-mips    : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
>     20    11.21 debian:experimental-x-mips64  : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
>     21    11.30 debian:experimental-x-mipsel  : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
>     37    12.07 ubuntu:18.04-x-arm            : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
>     42    11.91 ubuntu:18.04-x-riscv64        : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
>     44    13.17 ubuntu:18.04-x-sh4            : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
>     45    12.09 ubuntu:18.04-x-sparc64        : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
>   [perfbuilder@five ~]$
>
>   In file included from util/intel-pt-decoder/intel-pt-pkt-decoder.c:10:
>   /tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le16':
>   /tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:29: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
>      13 |         const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);      \
>         |                             ^
>   /tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:27:28: note: in expansion of macro '__get_unaligned_t'
>      27 |         return le16_to_cpu(__get_unaligned_t(__le16, p));
>         |                            ^~~~~~~~~~~~~~~~~
>
> This comes from the kernel, where the -Wattributes and -Wpacked isn't
> used, -Wpacked is already disabled, do it for the attributes as well.
>
> Fixes: a91c987254651443 ("perf tools: Add get_unaligned_leNN()")
> Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/7c5b626c-1de9-4c12-a781-e44985b4a797@xxxxxxxxx
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
>  tools/include/asm-generic/unaligned.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/tools/include/asm-generic/unaligned.h b/tools/include/asm-generic/unaligned.h
> index 156743d399aed223..2fd551915c2025ee 100644
> --- a/tools/include/asm-generic/unaligned.h
> +++ b/tools/include/asm-generic/unaligned.h
> @@ -8,6 +8,7 @@
>   */
>  #pragma GCC diagnostic push
>  #pragma GCC diagnostic ignored "-Wpacked"
> +#pragma GCC diagnostic ignored "-Wattributes"
>
>  #define __get_unaligned_t(type, ptr) ({                                                \
>         const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);      \
> --
> 2.41.0
>