LIBBPF_OPTS is implemented as a mix of field declaration and memset
+ assignment. This makes it neither variable declaration nor purely
statements, which is a problem, because you can't mix it with either
other variable declarations nor other function statements, because C90
compiler mode emits warning on mixing all that together.
This patch changes LIBBPF_OPTS into a strictly declaration of variable
and solves this problem, as can be seen in case of bpftool, which
previously would emit compiler warning, if done this way (LIBBPF_OPTS as
part of function variables declaration block).
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
tools/bpf/bpftool/prog.c | 6 +++---
tools/lib/bpf/libbpf.h | 13 +++++++------
2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 27da96a797ab..1a7e8ddf8232 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1093,6 +1093,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
{
struct bpf_object_load_attr load_attr = { 0 };
enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
+ LIBBPF_OPTS(bpf_object_open_opts, open_opts,
+ .relaxed_maps = relaxed_maps,
+ );
enum bpf_attach_type expected_attach_type;
struct map_replace *map_replace = NULL;
struct bpf_program *prog = NULL, *pos;
@@ -1106,9 +1109,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
const char *file;
int idx, err;
- LIBBPF_OPTS(bpf_object_open_opts, open_opts,
- .relaxed_maps = relaxed_maps,
- );
if (!REQ_ARGS(2))
return -1;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 0fdf086beba7..bf105e9e866f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -77,12 +77,13 @@ struct bpf_object_open_attr {
* bytes, but that's the best way I've found and it seems to work in practice.
*/
#define LIBBPF_OPTS(TYPE, NAME, ...) \
- struct TYPE NAME; \
- memset(&NAME, 0, sizeof(struct TYPE)); \
- NAME = (struct TYPE) { \
- .sz = sizeof(struct TYPE), \
- __VA_ARGS__ \
- }
+ struct TYPE NAME = ({ \
+ memset(&NAME, 0, sizeof(struct TYPE)); \
+ (struct TYPE) { \
+ .sz = sizeof(struct TYPE), \
+ __VA_ARGS__ \
+ }; \
+ })
struct bpf_object_open_opts {
/* size of this struct, for forward/backward compatiblity */
--
2.17.1
