Andrii Nakryiko wrote: > When generated BPF skeleton header is included in C++ code base, some > compiler setups will emit warning about using language extensions due to > typeof() usage, resulting in something like: > > error: extension used [-Werror,-Wlanguage-extension-token] > obj->struct_ops.empty_tcp_ca = (typeof(obj->struct_ops.empty_tcp_ca)) > ^ > > It looks like __typeof__() is a preferred way to do typeof() with better > C++ compatibility behavior, so switch to that. With __typeof__() we get > no such warning. > > Fixes: c2a0257c1edf ("bpftool: Cast pointers for shadow types explicitly.") > Fixes: 00389c58ffe9 ("bpftool: Add support for subskeletons") > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > --- > tools/bpf/bpftool/gen.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > index 786268f1a483..b3979ddc0189 100644 > --- a/tools/bpf/bpftool/gen.c > +++ b/tools/bpf/bpftool/gen.c > @@ -386,7 +386,7 @@ static int codegen_subskel_datasecs(struct bpf_object *obj, const char *obj_name > */ > needs_typeof = btf_is_array(var) || btf_is_ptr_to_func_proto(btf, var); > if (needs_typeof) > - printf("typeof("); > + printf("__typeof__("); > > err = btf_dump__emit_type_decl(d, var_type_id, &opts); > if (err) > @@ -1131,7 +1131,7 @@ static void gen_st_ops_shadow_init(struct btf *btf, struct bpf_object *obj) > continue; > codegen("\ > \n\ > - obj->struct_ops.%1$s = (typeof(obj->struct_ops.%1$s))\n\ > + obj->struct_ops.%1$s = (__typeof__(obj->struct_ops.%1$s))\n\ > bpf_map__initial_value(obj->maps.%1$s, NULL);\n\ > \n\ > ", ident); > -- > 2.43.0 > > sure. Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>