[PATCH bpf-next] selftests/bpf: test_progs option for getting number of tests

[Jesper Dangaard Brouer <brouer@xxxxxxxxxx>]

It can be practial to get the number of tests that test_progs
contain.  This could for example be used to create a shell
for-loop construct that runs the individual tests.

Like:
 for N in $(seq 1 $(./test_progs -c)); do
   ./test_progs -n $N 2>&1 > result_test_${N}.log &
 done ; wait

Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
 tools/testing/selftests/bpf/test_progs.c |   11 +++++++++++
 tools/testing/selftests/bpf/test_progs.h |    1 +
 2 files changed, 12 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 54fa5fa688ce..1aa5360c427f 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -366,6 +366,7 @@ enum ARG_KEYS {
 	ARG_TEST_NAME_BLACKLIST = 'b',
 	ARG_VERIFIER_STATS = 's',
 	ARG_VERBOSE = 'v',
+	ARG_GET_TEST_CNT = 'c',
 };
 
 static const struct argp_option opts[] = {
@@ -379,6 +380,8 @@ static const struct argp_option opts[] = {
 	  "Output verifier statistics", },
 	{ "verbose", ARG_VERBOSE, "LEVEL", OPTION_ARG_OPTIONAL,
 	  "Verbose output (use -vv or -vvv for progressively verbose output)" },
+	{ "count", ARG_GET_TEST_CNT, NULL, 0,
+	  "Get number of top-level tests " },
 	{},
 };
 
@@ -511,6 +514,9 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 			}
 		}
 		break;
+	case ARG_GET_TEST_CNT:
+		env->get_test_cnt = true;
+		break;
 	case ARGP_KEY_ARG:
 		argp_usage(state);
 		break;
@@ -643,6 +649,11 @@ int main(int argc, char **argv)
 		return -1;
 	}
 
+	if (env.get_test_cnt) {
+		printf("%d\n", prog_test_cnt);
+		return EXIT_SUCCESS;
+	}
+
 	stdio_hijack();
 	for (i = 0; i < prog_test_cnt; i++) {
 		struct prog_test_def *test = &prog_test_defs[i];
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index f4503c926aca..0030584619c3 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -66,6 +66,7 @@ struct test_env {
 	enum verbosity verbosity;
 
 	bool jit_enabled;
+	bool get_test_cnt;
 
 	struct prog_test_def *test;
 	FILE *stdout;