On Wed, Dec 8, 2021 at 9:04 PM Yonghong Song <yhs@xxxxxx> wrote:
>
> The following warning is triggered when I used clang compiler
> to build the selftest.
>
> /.../prog_tests/btf_dedup_split.c:368:6: warning: variable 'btf2' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
> if (!ASSERT_OK(err, "btf_dedup"))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /.../prog_tests/btf_dedup_split.c:424:12: note: uninitialized use occurs here
> btf__free(btf2);
> ^~~~
> /.../prog_tests/btf_dedup_split.c:368:2: note: remove the 'if' if its condition is always false
> if (!ASSERT_OK(err, "btf_dedup"))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /.../prog_tests/btf_dedup_split.c:343:25: note: initialize the variable 'btf2' to silence this warning
> struct btf *btf1, *btf2;
> ^
> = NULL
>
> Initialize local variable btf2 = NULL and the warning is gone.
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
Added:
Fixes: 9a49afe6f5a5 ("selftests/bpf: Add btf_dedup case with
duplicated structs within CU")
and pushed to bpf-next. Thanks.
> tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> index 878a864dae3b..90aac437576d 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> @@ -340,7 +340,7 @@ static void btf_add_dup_struct_in_cu(struct btf *btf, int start_id)
>
> static void test_split_dup_struct_in_cu()
> {
> - struct btf *btf1, *btf2;
> + struct btf *btf1, *btf2 = NULL;
> int err;
>
> /* generate the base data.. */
> --
> 2.30.2
>
