selftests/bpf: Extract parse_num_list into generic testing_helpers.c

Add testing_helpers.c, which will contain generic helpers for test runners and
tests needing some common generic functionality, like parsing a set of
numbers.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512192445.2351848-2-andriin@fb.com

tools/testing/selftests/bpf/Makefile

@@ -355,7 +355,8 @@ endef
 TRUNNER_TESTS_DIR := prog_tests
 TRUNNER_BPF_PROGS_DIR := progs
 TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c	\
-			 network_helpers.c flow_dissector_load.h
+			 network_helpers.c testing_helpers.c		\
+			 flow_dissector_load.h
 TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read				\
 		       $(wildcard progs/btf_dump_test_case_*.c)
 TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE

tools/testing/selftests/bpf/test_progs.c

@@ -438,67 +438,6 @@ err:
 	return -ENOMEM;
 }
 
-int parse_num_list(const char *s, struct test_selector *sel)
-{
-	int i, set_len = 0, new_len, num, start = 0, end = -1;
-	bool *set = NULL, *tmp, parsing_end = false;
-	char *next;
-
-	while (s[0]) {
-		errno = 0;
-		num = strtol(s, &next, 10);
-		if (errno)
-			return -errno;
-
-		if (parsing_end)
-			end = num;
-		else
-			start = num;
-
-		if (!parsing_end && *next == '-') {
-			s = next + 1;
-			parsing_end = true;
-			continue;
-		} else if (*next == ',') {
-			parsing_end = false;
-			s = next + 1;
-			end = num;
-		} else if (*next == '\0') {
-			parsing_end = false;
-			s = next;
-			end = num;
-		} else {
-			return -EINVAL;
-		}
-
-		if (start > end)
-			return -EINVAL;
-
-		if (end + 1 > set_len) {
-			new_len = end + 1;
-			tmp = realloc(set, new_len);
-			if (!tmp) {
-				free(set);
-				return -ENOMEM;
-			}
-			for (i = set_len; i < start; i++)
-				tmp[i] = false;
-			set = tmp;
-			set_len = new_len;
-		}
-		for (i = start; i <= end; i++)
-			set[i] = true;
-	}
-
-	if (!set)
-		return -EINVAL;
-
-	sel->num_set = set;
-	sel->num_set_len = set_len;
-
-	return 0;
-}
-
 extern int extra_prog_load_log_flags;
 
 static error_t parse_arg(int key, char *arg, struct argp_state *state)
@@ -512,13 +451,15 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 		if (subtest_str) {
 			*subtest_str = '\0';
 			if (parse_num_list(subtest_str + 1,
-					   &env->subtest_selector)) {
+					   &env->subtest_selector.num_set,
+					   &env->subtest_selector.num_set_len)) {
 				fprintf(stderr,
 					"Failed to parse subtest numbers.\n");
 				return -EINVAL;
 			}
 		}
-		if (parse_num_list(arg, &env->test_selector)) {
+		if (parse_num_list(arg, &env->test_selector.num_set,
+				   &env->test_selector.num_set_len)) {
 			fprintf(stderr, "Failed to parse test numbers.\n");
 			return -EINVAL;
 		}

tools/testing/selftests/bpf/test_progs.h

@@ -37,6 +37,7 @@ typedef __u16 __sum16;
 #include "bpf_util.h"
 #include <bpf/bpf_endian.h>
 #include "trace_helpers.h"
+#include "testing_helpers.h"
 #include "flow_dissector_load.h"
 
 enum verbosity {

tools/testing/selftests/bpf/testing_helpers.c

@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdlib.h>
+#include <errno.h>
+#include "testing_helpers.h"
+
+int parse_num_list(const char *s, bool **num_set, int *num_set_len)
+{
+	int i, set_len = 0, new_len, num, start = 0, end = -1;
+	bool *set = NULL, *tmp, parsing_end = false;
+	char *next;
+
+	while (s[0]) {
+		errno = 0;
+		num = strtol(s, &next, 10);
+		if (errno)
+			return -errno;
+
+		if (parsing_end)
+			end = num;
+		else
+			start = num;
+
+		if (!parsing_end && *next == '-') {
+			s = next + 1;
+			parsing_end = true;
+			continue;
+		} else if (*next == ',') {
+			parsing_end = false;
+			s = next + 1;
+			end = num;
+		} else if (*next == '\0') {
+			parsing_end = false;
+			s = next;
+			end = num;
+		} else {
+			return -EINVAL;
+		}
+
+		if (start > end)
+			return -EINVAL;
+
+		if (end + 1 > set_len) {
+			new_len = end + 1;
+			tmp = realloc(set, new_len);
+			if (!tmp) {
+				free(set);
+				return -ENOMEM;
+			}
+			for (i = set_len; i < start; i++)
+				tmp[i] = false;
+			set = tmp;
+			set_len = new_len;
+		}
+		for (i = start; i <= end; i++)
+			set[i] = true;
+	}
+
+	if (!set)
+		return -EINVAL;
+
+	*num_set = set;
+	*num_set_len = set_len;
+
+	return 0;
+}

tools/testing/selftests/bpf/testing_helpers.h

@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdbool.h>
+
+int parse_num_list(const char *s, bool **set, int *set_len);