When used on externs SEC() macro will trigger compilation warning about
inapplicable `__attribute__((used))`. That's expected for extern declarations,
so suppress it with the corresponding _Pragma.
Acked-by: Yonghong Song <yhs@xxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/bpf_helpers.h | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index b904128626c2..75c7581b304c 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -25,9 +25,16 @@
/*
* Helper macro to place programs, maps, license in
* different sections in elf_bpf file. Section names
- * are interpreted by elf_bpf loader
+ * are interpreted by libbpf depending on the context (BPF programs, BPF maps,
+ * extern variables, etc).
+ * To allow use of SEC() with externs (e.g., for extern .maps declarations),
+ * make sure __attribute__((unused)) doesn't trigger compilation warning.
*/
-#define SEC(NAME) __attribute__((section(NAME), used))
+#define SEC(name) \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wignored-attributes\"") \
+ __attribute__((section(name), used)) \
+ _Pragma("GCC diagnostic pop") \
/* Avoid 'linux/stddef.h' definition of '__always_inline'. */
#undef __always_inline
--
2.30.2
