From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
Ian Rogers <irogers@google.com>,
James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-perf-users@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH 2/2] perf build: Add -Wno-missing-declarations for GEN_VMLINUX_H=1
Date: Tue, 7 Apr 2026 22:52:59 -0700 [thread overview]
Message-ID: <20260408055259.374744-2-namhyung@kernel.org> (raw)
In-Reply-To: <20260408055259.374744-1-namhyung@kernel.org>
On my system, `make GEN_VMLINUX_H=1` fails with a lot of error messages
like below:
./util/bpf_skel/vmlinux.h:134488:4: error: declaration does not declare anything [-Werror,-Wmissing-declarations]
134488 | struct freelist_counters;
| ^~~~~~~~~~~~~~~~~~~~~~~~
make[2]: *** [Makefile.perf:1249: linux/tools/perf/util/bpf_skel/.tmp/lock_contention.bpf.o] Error 1
It seems clang doesn't like forward declarations in the current setting.
Let's suppress the warning by adding the no warning flags.
Cc: bpf@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/Makefile.perf | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index cee19c923c0607d2..a41e0dd34d8df660 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -1249,7 +1249,7 @@ $(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) $(SKEL_OUT)/vmlinux.h
$(QUIET_CLANG)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \
$(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \
-include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \
- -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@
+ -Wno-missing-declarations -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@
$(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o | $(BPFTOOL)
$(QUIET_GENSKEL)$(BPFTOOL) gen skeleton $< > $@
--
2.53.0
next prev parent reply other threads:[~2026-04-08 5:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-08 5:52 [PATCH 1/2] perf build: Update error message for BUILD_NONDISTRO=1 Namhyung Kim
2026-04-08 5:52 ` Namhyung Kim [this message]
2026-04-08 6:00 ` [PATCH 2/2] perf build: Add -Wno-missing-declarations for GEN_VMLINUX_H=1 sashiko-bot
2026-04-08 6:11 ` [PATCH 1/2] perf build: Update error message for BUILD_NONDISTRO=1 Ian Rogers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260408055259.374744-2-namhyung@kernel.org \
--to=namhyung@kernel.org \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=bpf@vger.kernel.org \
--cc=irogers@google.com \
--cc=james.clark@linaro.org \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox