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Commit 2119f218 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

bpftool: add C output format option to btf dump subcommand 



Utilize new libbpf's btf_dump API to emit BTF as a C definitions.

Acked-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 2d2a3ad8

tools/bpf/bpftool/btf.c

+73 −2
Original line number Diff line number Diff line
@@ -340,11 +340,49 @@ static int dump_btf_raw(const struct btf *btf, 
	return 0;

}



static void __printf(2, 0) btf_dump_printf(void *ctx,

					   const char *fmt, va_list args)

{

	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 +469,29 @@ 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) {

				dump_c = false;

			} else {

				p_err("unrecognized format specifier: '%s', possible values: raw, c",

				      *argv);

				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 +505,16 @@ 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 +530,11 @@ 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"