From: Leo Yan <leo.yan@arm.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Quentin Monnet <qmo@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>,
Hao Luo <haoluo@google.com>,
James Clark <james.clark@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
llvm@lists.linux.dev, bpf@vger.kernel.org,
Leo Yan <leo.yan@arm.com>
Subject: [PATCH 3/8] bpftool: Conditionally add -Wformat-signedness flag
Date: Thu, 25 Sep 2025 11:26:27 +0100 [thread overview]
Message-ID: <20250925-perf_build_android_ndk-v1-3-8b35aadde3dc@arm.com> (raw)
In-Reply-To: <20250925-perf_build_android_ndk-v1-0-8b35aadde3dc@arm.com>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:
warning: unknown warning option '-Wformat-signedness' [-Wunknown-warning-option]
Conditionally add the option only when it is supported by compiler.
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
tools/bpf/bpftool/Makefile | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 9e9a5f006cd2aabe1e89bd83e394455c0d4473e0..948a0cc98b39d3f9afa0de73643eab04e8798ff5 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -64,11 +64,21 @@ $(LIBBPF_BOOTSTRAP)-clean: FORCE | $(LIBBPF_BOOTSTRAP_OUTPUT)
prefix ?= /usr/local
bash_compdir ?= /usr/share/bash-completion/completions
+try-run = $(shell set -e; \
+ if ($(1)) >/dev/null 2>&1; \
+ then echo "$(2)"; \
+ else echo "$(3)"; \
+ fi)
+
+__cc-option = $(call try-run,\
+ $(1) -Werror $(2) -c -x c /dev/null -o /dev/null,$(2),)
+cc-option = $(call __cc-option, $(CC),$(1))
+
CFLAGS += -O2
CFLAGS += -W
CFLAGS += -Wall
CFLAGS += -Wextra
-CFLAGS += -Wformat-signedness
+CFLAGS += $(call cc-option,-Wformat-signedness)
CFLAGS += -Wno-unused-parameter
CFLAGS += -Wno-missing-field-initializers
CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
--
2.34.1
next prev parent reply other threads:[~2025-09-25 10:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-25 10:26 [PATCH 0/8] perf build: Support building with Clang Leo Yan
2025-09-25 10:26 ` [PATCH 1/8] tools build: Align warning options with perf Leo Yan
2025-09-25 10:26 ` [PATCH 2/8] perf python: split Clang options when invoking Popen Leo Yan
2025-09-25 10:26 ` Leo Yan [this message]
2025-09-25 10:42 ` [PATCH 3/8] bpftool: Conditionally add -Wformat-signedness flag Quentin Monnet
2025-09-25 12:43 ` Leo Yan
2025-09-25 10:26 ` [PATCH 4/8] perf test coresight: Dismiss clang warning for memcpy thread Leo Yan
2025-09-25 19:38 ` Ian Rogers
2025-09-26 16:19 ` Leo Yan
2025-09-25 10:26 ` [PATCH 5/8] perf test coresight: Dismiss clang warning for thread loop Leo Yan
2025-09-25 10:26 ` [PATCH 6/8] perf test coresight: Dismiss clang warning for unroll loop thread Leo Yan
2025-09-25 10:26 ` [PATCH 7/8] perf build: Support build with clang Leo Yan
2025-09-25 10:26 ` [PATCH 8/8] perf docs: Document building with Clang Leo Yan
2025-09-25 19:43 ` Ian Rogers
2025-09-26 15:41 ` Leo Yan
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=20250925-perf_build_android_ndk-v1-3-8b35aadde3dc@arm.com \
--to=leo.yan@arm.com \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=eddyz87@gmail.com \
--cc=haoluo@google.com \
--cc=irogers@google.com \
--cc=james.clark@linaro.org \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=justinstitt@google.com \
--cc=kpsingh@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=martin.lau@linux.dev \
--cc=morbo@google.com \
--cc=namhyung@kernel.org \
--cc=nathan@kernel.org \
--cc=nick.desaulniers+lkml@gmail.com \
--cc=qmo@kernel.org \
--cc=sdf@fomichev.me \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/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;
as well as URLs for NNTP newsgroup(s).