On Thu, Oct 21, 2021 at 10:09 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> BTF_KIND_TAG is present in libbtf 6.0 but not libbtf in 5.15rc4. Make
> the code requiring it conditionally compiled in.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> btf_encoder.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/btf_encoder.c b/btf_encoder.c
> index c341f95..1694679 100644
> --- a/btf_encoder.c
> +++ b/btf_encoder.c
> @@ -31,6 +31,15 @@
> #include <errno.h>
> #include <stdint.h>
>
> +#ifndef LIBBPF_MINOR_VERSION
> +/*
> + * The libbpf version is not defined in older versions, workaround by assuming
> + * version 0.5.
> + */
> +#define LIBBPF_MAJOR_VERSION 0
> +#define LIBBPF_MINOR_VERSION 5
> +#endif
> +
> struct elf_function {
> const char *name;
> bool generated;
> @@ -141,7 +150,9 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
> [BTF_KIND_VAR] = "VAR",
> [BTF_KIND_DATASEC] = "DATASEC",
> [BTF_KIND_FLOAT] = "FLOAT",
> +#if LIBBPF_MINOR_VERSION > 5
this will break on 1.0
> [BTF_KIND_TAG] = "TAG",
> +#endif
> };
>
> static const char *btf__printable_name(const struct btf *btf, uint32_t offset)
> @@ -648,6 +659,7 @@ static int32_t btf_encoder__add_datasec(struct btf_encoder *encoder, const char
> static int32_t btf_encoder__add_tag(struct btf_encoder *encoder, const char *value, uint32_t type,
> int component_idx)
> {
> +#if LIBBPF_MINOR_VERSION > 5
> struct btf *btf = encoder->btf;
> const struct btf_type *t;
> int32_t id;
> @@ -663,6 +675,10 @@ static int32_t btf_encoder__add_tag(struct btf_encoder *encoder, const char *val
> }
>
> return id;
> +#else
> + fprintf(stderr, "error: unable to encode BTF_KIND_TAG due to old libbtf\n");
> + return -ENOTSUP;
> +#endif
> }
>
> /*
> --
> 2.33.0.1079.g6e70778dc9-goog
>
