Commit 0fec7a3c authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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libbpf: Suppress compiler warning when using SEC() macro with externs 



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.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-4-andrii@kernel.org
parent 5b438f01

tools/lib/bpf/bpf_helpers.h

+9 −2
Original line number Diff line number Diff line
@@ -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