Hi Andrii, Some nits inline, nothing blocking though.
2019-05-23 13:42 UTC-0700 ~ Andrii Nakryiko <[email protected]> > Utilize new libbpf's btf_dump API to emit BTF as a C definitions. > > Signed-off-by: Andrii Nakryiko <[email protected]> > --- > tools/bpf/bpftool/btf.c | 74 +++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 72 insertions(+), 2 deletions(-) > > diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c > index a22ef6587ebe..1cdbfad42b38 100644 > --- a/tools/bpf/bpftool/btf.c > +++ b/tools/bpf/bpftool/btf.c > @@ -340,11 +340,48 @@ static int dump_btf_raw(const struct btf *btf, > return 0; > } > > +static void btf_dump_printf(void *ctx, const char *fmt, va_list args) Nit: This function could have a printf attribute ("__printf(2, 0)"). > +{ > + vfprintf(stdout, fmt, args); > +} > + > +static int dump_btf_c(const struct btf *btf, > + __u32 *root_type_ids, int root_type_cnt) > +{ > + struct btf_dump *d; > + int err = 0, i; > + > + d = btf_dump__new(btf, NULL, NULL, btf_dump_printf); > + if (IS_ERR(d)) > + return PTR_ERR(d); > + > + if (root_type_cnt) { > + for (i = 0; i < root_type_cnt; i++) { > + err = btf_dump__dump_type(d, root_type_ids[i]); > + if (err) > + goto done; > + } > + } else { > + int cnt = btf__get_nr_types(btf); > + > + for (i = 1; i <= cnt; i++) { > + err = btf_dump__dump_type(d, i); > + if (err) > + goto done; > + } > + } > + > +done: > + btf_dump__free(d); > + return err; > +} > + > static int do_dump(int argc, char **argv) > { > struct btf *btf = NULL; > __u32 root_type_ids[2]; > int root_type_cnt = 0; > + bool dump_c = false; > __u32 btf_id = -1; > const char *src; > int fd = -1; > @@ -431,6 +468,29 @@ static int do_dump(int argc, char **argv) > goto done; > } > > + while (argc) { > + if (is_prefix(*argv, "format")) { > + NEXT_ARG(); > + if (argc < 1) { > + p_err("expecting value for 'format' option\n"); > + goto done; > + } > + if (strcmp(*argv, "c") == 0) { > + dump_c = true; > + } else if (strcmp(*argv, "raw") == 0) { Do you think we could use is_prefix() instead of strcmp() here? > + dump_c = false; > + } else { > + p_err("unrecognized format specifier: '%s'", > + *argv); Would it be worth reminding the user about the valid specifiers in that message? (But then we already have it in do_help(), so maybe not.) > + goto done; > + } > + NEXT_ARG(); > + } else { > + p_err("unrecognized option: '%s'", *argv); > + goto done; > + } > + } > + > if (!btf) { > err = btf__get_from_id(btf_id, &btf); > if (err) { > @@ -444,7 +504,16 @@ static int do_dump(int argc, char **argv) > } > } > > - dump_btf_raw(btf, root_type_ids, root_type_cnt); > + if (dump_c) { > + if (json_output) { > + p_err("JSON output for C-syntax dump is not supported"); > + err = -ENOTSUP; > + goto done; > + } > + err = dump_btf_c(btf, root_type_ids, root_type_cnt); > + } else { > + err = dump_btf_raw(btf, root_type_ids, root_type_cnt); > + } > > done: > close(fd); > @@ -460,10 +529,11 @@ static int do_help(int argc, char **argv) > } > > fprintf(stderr, > - "Usage: %s btf dump BTF_SRC\n" > + "Usage: %s btf dump BTF_SRC [format FORMAT]\n" > " %s btf help\n" > "\n" > " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | > value | kv | all}] | file FILE }\n" > + " FORMAT := { raw | c }\n" > " " HELP_SPEC_MAP "\n" > " " HELP_SPEC_PROGRAM "\n" > " " HELP_SPEC_OPTIONS "\n" >
