From:   Alexander Lobakin <alexandr.lobakin@intel.com>
To:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>
Cc:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>,
        Kumar Kartikeya Dwivedi <memxor@gmail.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH bpf 2/2] samples: bpf: fix 'unknown warning group' build warning on Clang
Date:   Fri,  3 Dec 2021 20:50:04 +0100
Message-Id: <20211203195004.5803-3-alexandr.lobakin@intel.com>
In-Reply-To: <20211203195004.5803-1-alexandr.lobakin@intel.com>
References: <20211203195004.5803-1-alexandr.lobakin@intel.com>
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Clang doesn't have 'stringop-truncation' group like GCC does, and
complains about it when building samples which use xdp_sample_user
infra:

 samples/bpf/xdp_sample_user.h:48:32: warning: unknown warning group '-Wstringop-truncation', ignored [-Wunknown-warning-option]
 #pragma GCC diagnostic ignored "-Wstringop-truncation"
                                ^
[ repeat ]

Those are harmless, but avoidable when guarding it with ifdef.
I could guard push/pop as well, but this would require one more
ifdef cruft around a single line which I don't think is reasonable.

Fixes: 156f886cf697 ("samples: bpf: Add basic infrastructure for XDP samples")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
 samples/bpf/xdp_sample_user.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/samples/bpf/xdp_sample_user.h b/samples/bpf/xdp_sample_user.h
index d97465ff8c62..5f44b877ecf5 100644
--- a/samples/bpf/xdp_sample_user.h
+++ b/samples/bpf/xdp_sample_user.h
@@ -45,7 +45,9 @@ const char *get_driver_name(int ifindex);
 int get_mac_addr(int ifindex, void *mac_addr);
 
 #pragma GCC diagnostic push
+#ifndef __clang__
 #pragma GCC diagnostic ignored "-Wstringop-truncation"
+#endif
 __attribute__((unused))
 static inline char *safe_strncpy(char *dst, const char *src, size_t size)
 {
-- 
2.33.1