selftests/bpf: prevent unused variable warning in bpf_for()

Add __attribute__((unused)) to inner __p variable inside bpf_for(),
bpf_for_each(), and bpf_repeat() macros to avoid compiler warnings about
unused variable.

Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 43b154a..c95eb60 100644 (file)
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -115,7 +115,8 @@ extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __ksym;
        struct bpf_iter_##type ___it __attribute__((aligned(8), /* enforce, just in case */,    \
                                                    cleanup(bpf_iter_##type##_destroy))),       \
        /* ___p pointer is just to call bpf_iter_##type##_new() *once* to init ___it */         \
-                              *___p = (bpf_iter_##type##_new(&___it, ##args),                  \
+                              *___p __attribute__((unused)) = (                                \
+                                       bpf_iter_##type##_new(&___it, ##args),                  \
        /* this is a workaround for Clang bug: it currently doesn't emit BTF */                 \
        /* for bpf_iter_##type##_destroy() when used from cleanup() attribute */                \
                                        (void)bpf_iter_##type##_destroy, (void *)0);            \
@@ -143,7 +144,8 @@ extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __ksym;
        struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */        \
                                                 cleanup(bpf_iter_num_destroy))),               \
        /* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */         \
-                           *___p = (bpf_iter_num_new(&___it, (start), (end)),                  \
+                           *___p __attribute__((unused)) = (                                   \
+                               bpf_iter_num_new(&___it, (start), (end)),                       \
        /* this is a workaround for Clang bug: it currently doesn't emit BTF */                 \
        /* for bpf_iter_num_destroy() when used from cleanup() attribute */                     \
                                (void)bpf_iter_num_destroy, (void *)0);                         \
@@ -167,7 +169,8 @@ extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __ksym;
        struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */        \
                                                 cleanup(bpf_iter_num_destroy))),               \
        /* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */         \
-                           *___p = (bpf_iter_num_new(&___it, 0, (N)),                          \
+                           *___p __attribute__((unused)) = (                                   \
+                               bpf_iter_num_new(&___it, 0, (N)),                               \
        /* this is a workaround for Clang bug: it currently doesn't emit BTF */                 \
        /* for bpf_iter_num_destroy() when used from cleanup() attribute */                     \
                                (void)bpf_iter_num_destroy, (void *)0);                         \