From: James Hilliard <james.hilliard1@gmail.com>
To: bpf@vger.kernel.org
Cc: James Hilliard <james.hilliard1@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4] libbpf: disable SEC pragma macro on GCC
Date: Wed, 6 Jul 2022 05:18:38 -0600 [thread overview]
Message-ID: <20220706111839.1247911-1-james.hilliard1@gmail.com> (raw)
It seems the gcc preprocessor breaks with pragmas when surrounding
__attribute__.
Disable these pragmas on GCC due to upstream bugs see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55578
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90400
Fixes errors like:
error: expected identifier or '(' before '#pragma'
106 | SEC("cgroup/bind6")
| ^~~
error: expected '=', ',', ';', 'asm' or '__attribute__' before '#pragma'
114 | char _license[] SEC("license") = "GPL";
| ^~~
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
Changes v3 -> v4:
- disable SEC pragmas entirely on GCC
Changes v2 -> v3:
- just fix SEC pragma
Changes v1 -> v2:
- replace typeof with __typeof__ instead of changing pragma macros
---
tools/lib/bpf/bpf_helpers.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index fb04eaf367f1..7349b16b8e2f 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -22,12 +22,25 @@
* To allow use of SEC() with externs (e.g., for extern .maps declarations),
* make sure __attribute__((unused)) doesn't trigger compilation warning.
*/
+#if __GNUC__ && !__clang__
+
+/*
+ * Pragma macros are broken on GCC
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55578
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90400
+ */
+#define SEC(name) __attribute__((section(name), used))
+
+#else
+
#define SEC(name) \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wignored-attributes\"") \
__attribute__((section(name), used)) \
_Pragma("GCC diagnostic pop") \
+#endif
+
/* Avoid 'linux/stddef.h' definition of '__always_inline'. */
#undef __always_inline
#define __always_inline inline __attribute__((always_inline))
--
2.34.1
next reply other threads:[~2022-07-06 11:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-06 11:18 James Hilliard [this message]
2022-07-08 22:20 ` [PATCH v4] libbpf: disable SEC pragma macro on GCC patchwork-bot+netdevbpf
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