Re: [PATCH] bpftool: use btf_vlen()/btf_kind()/btf_kflag() helpers consistently

[Andrii Nakryiko]

On Wed, Jul 1, 2026 at 8:05 AM KaFai Wan <kafai.wan@xxxxxxxxx> wrote:
>
> On Wed, 2026-07-01 at 14:25 +0800, luoliang@xxxxxxxxxx wrote:
> > From: luoliang <luoliang@xxxxxxxxxx>
> >
> > The btf_vlen(), btf_kind() and btf_kflag() inline helpers defined in
> > tools/lib/bpf/btf.h are thin wrappers around the BTF_INFO_VLEN(),
> > BTF_INFO_KIND() and BTF_INFO_KFLAG() UAPI macros - each one simply
> > returns the corresponding macro applied to t->info.
> >
> > bpftool already uses these helpers in most places, but 13 call sites
> > in btf.c and btf_dumper.c still open-code the raw macros. Use the
> > helpers consistently, matching the rest of bpftool as well as libbpf.
> >
> > No functional change.
> >
> > Signed-off-by: Liang Luo <luoliang@xxxxxxxxxx>
> > ---
> >  tools/bpf/bpftool/btf.c        | 12 ++++++------
> >  tools/bpf/bpftool/btf_dumper.c | 14 +++++++-------
> >  2 files changed, 13 insertions(+), 13 deletions(-)
> >
> > diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
> > index 6ef908adf3a4..24e4cb600b3f 100644
> > --- a/tools/bpf/bpftool/btf.c
> > +++ b/tools/bpf/bpftool/btf.c
> > @@ -179,7 +179,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >       case BTF_KIND_STRUCT:
> >       case BTF_KIND_UNION: {
> >               const struct btf_member *m = (const void *)(t + 1);
> > -             __u32 i, vlen = BTF_INFO_VLEN(t->info);
> > +             __u32 i, vlen = btf_vlen(t);
> >
> >               if (json_output) {
> >                       jsonw_uint_field(w, "size", t->size);
> > @@ -193,7 +193,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >                       const char *name = btf_str(btf, m->name_off);
> >                       __u32 bit_off, bit_sz;
> >
> > -                     if (BTF_INFO_KFLAG(t->info)) {
> > +                     if (btf_kflag(t)) {
> >                               bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
> >                               bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
> >                       } else {
> > @@ -224,7 +224,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >       }
> >       case BTF_KIND_ENUM: {
> >               const struct btf_enum *v = (const void *)(t + 1);
> > -             __u32 i, vlen = BTF_INFO_VLEN(t->info);
> > +             __u32 i, vlen = btf_vlen(t);
> >               const char *encoding;
> >
> >               encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
> > @@ -300,7 +300,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >               break;
> >       }
> >       case BTF_KIND_FWD: {
> > -             const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
> > +             const char *fwd_kind = btf_kflag(t) ? "union"
> >                                                              : "struct";
> nit: coding style, and can be one line.

this is the only line that would benefit from a tiny amount of human
touch and judgement call, and yet...

pw-bot: cr


> >
> >               if (json_output)
> > @@ -322,7 +322,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >       }
> >       case BTF_KIND_FUNC_PROTO: {
> >               const struct btf_param *p = (const void *)(t + 1);
> > -             __u32 i, vlen = BTF_INFO_VLEN(t->info);
> > +             __u32 i, vlen = btf_vlen(t);
> >
> >               if (json_output) {
> >                       jsonw_uint_field(w, "ret_type_id", t->type);
> > @@ -365,7 +365,7 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
> >       case BTF_KIND_DATASEC: {
> >               const struct btf_var_secinfo *v = (const void *)(t + 1);
> >               const struct btf_type *vt;
> > -             __u32 i, vlen = BTF_INFO_VLEN(t->info);
> > +             __u32 i, vlen = btf_vlen(t);
> >
> >               if (json_output) {
> >                       jsonw_uint_field(w, "size", t->size);
> > diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
> > index 9dc8425b1789..e4075824343f 100644
> > --- a/tools/bpf/bpftool/btf_dumper.c
> > +++ b/tools/bpf/bpftool/btf_dumper.c
> > @@ -476,8 +476,8 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
> >       if (!t)
> >               return -EINVAL;
> >
> > -     kind_flag = BTF_INFO_KFLAG(t->info);
> > -     vlen = BTF_INFO_VLEN(t->info);
> > +     kind_flag = btf_kflag(t);
> > +     vlen = btf_vlen(t);
> >       jsonw_start_object(d->jw);
> >       m = (struct btf_member *)(t + 1);
> >
> > @@ -535,7 +535,7 @@ static int btf_dumper_datasec(const struct btf_dumper *d, __u32 type_id,
> >       if (!t)
> >               return -EINVAL;
> >
> > -     vlen = BTF_INFO_VLEN(t->info);
> > +     vlen = btf_vlen(t);
> >       vsi = (struct btf_var_secinfo *)(t + 1);
> >
> >       jsonw_start_object(d->jw);
> > @@ -557,7 +557,7 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
> >  {
> >       const struct btf_type *t = btf__type_by_id(d->btf, type_id);
> >
> > -     switch (BTF_INFO_KIND(t->info)) {
> > +     switch (btf_kind(t)) {
> >       case BTF_KIND_INT:
> >               return btf_dumper_int(t, bit_offset, data, d->jw,
> >                                    d->is_plain_text);
> > @@ -631,7 +631,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
> >
> >       t = btf__type_by_id(btf, type_id);
> >
> > -     switch (BTF_INFO_KIND(t->info)) {
> > +     switch (btf_kind(t)) {
> >       case BTF_KIND_INT:
> >       case BTF_KIND_TYPEDEF:
> >       case BTF_KIND_FLOAT:
> > @@ -661,7 +661,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
> >               break;
> >       case BTF_KIND_FWD:
> >               BTF_PRINT_ARG("%s %s ",
> > -                           BTF_INFO_KFLAG(t->info) ? "union" : "struct",
> > +                           btf_kflag(t) ? "union" : "struct",
> >                             btf__name_by_offset(btf, t->name_off));
> >               break;
> >       case BTF_KIND_VOLATILE:
> > @@ -718,7 +718,7 @@ static int btf_dump_func(const struct btf *btf, char *func_sig,
> >               BTF_PRINT_ARG("%s(", btf__name_by_offset(btf, func->name_off));
> >       else
> >               BTF_PRINT_ARG("(");
> > -     vlen = BTF_INFO_VLEN(func_proto->info);
> > +     vlen = btf_vlen(func_proto);
> >       for (i = 0; i < vlen; i++) {
> >               struct btf_param *arg = &((struct btf_param *)(func_proto + 1))[i];
> >
>