tools/bpf: refactor test_btf pretty printing for multiple map value formats

The test_btf pretty print is refactored in order to easily
support multiple map value formats. The next patch will
add __int128 type tests which needs macro guard __SIZEOF_INT128__.
There is no functionality change with this patch.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/test_btf.c

@@ -18,6 +18,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <assert.h>
 #include <bpf/libbpf.h>
 #include <bpf/btf.h>
 
@@ -134,6 +135,11 @@ static struct btf_header hdr_tmpl = {
 	.hdr_len = sizeof(struct btf_header),
 };
 
+/* several different mapv kinds(types) supported by pprint */
+enum pprint_mapv_kind_t {
+	PPRINT_MAPV_KIND_BASIC = 0,
+};
+
 struct btf_raw_test {
 	const char *descr;
 	const char *str_sec;
@@ -156,6 +162,7 @@ struct btf_raw_test {
 	int type_off_delta;
 	int str_off_delta;
 	int str_len_delta;
+	enum pprint_mapv_kind_t mapv_kind;
 };
 
 #define BTF_STR_SEC(str) \
@@ -3880,12 +3887,23 @@ static struct btf_pprint_test_meta {
 
 };
 
+static size_t get_pprint_mapv_size(enum pprint_mapv_kind_t mapv_kind)
+{
+	if (mapv_kind == PPRINT_MAPV_KIND_BASIC)
+		return sizeof(struct pprint_mapv);
 
-static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i,
+	assert(0);
+}
+
+static void set_pprint_mapv(enum pprint_mapv_kind_t mapv_kind,
+			    void *mapv, uint32_t i,
 			    int num_cpus, int rounded_value_size)
 {
 	int cpu;
 
+	if (mapv_kind == PPRINT_MAPV_KIND_BASIC) {
+		struct pprint_mapv *v = mapv;
+
 		for (cpu = 0; cpu < num_cpus; cpu++) {
 			v->ui32 = i + cpu;
 			v->si32 = -i;
@@ -3898,6 +3916,40 @@ static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i,
 			v->bits2c = 1;
 			v = (void *)v + rounded_value_size;
 		}
+	}
+}
+
+ssize_t get_pprint_expected_line(enum pprint_mapv_kind_t mapv_kind,
+				 char *expected_line, ssize_t line_size,
+				 bool percpu_map, unsigned int next_key,
+				 int cpu, void *mapv)
+{
+	ssize_t nexpected_line = -1;
+
+	if (mapv_kind == PPRINT_MAPV_KIND_BASIC) {
+		struct pprint_mapv *v = mapv;
+
+		nexpected_line = snprintf(expected_line, line_size,
+					  "%s%u: {%u,0,%d,0x%x,0x%x,0x%x,"
+					  "{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s,"
+					  "%u,0x%x}\n",
+					  percpu_map ? "\tcpu" : "",
+					  percpu_map ? cpu : next_key,
+					  v->ui32, v->si32,
+					  v->unused_bits2a,
+					  v->bits28,
+					  v->unused_bits2b,
+					  v->ui64,
+					  v->ui8a[0], v->ui8a[1],
+					  v->ui8a[2], v->ui8a[3],
+					  v->ui8a[4], v->ui8a[5],
+					  v->ui8a[6], v->ui8a[7],
+					  pprint_enum_str[v->aenum],
+					  v->ui32b,
+					  v->bits2c);
+	}
+
+	return nexpected_line;
 }
 
 static int check_line(const char *expected_line, int nexpected_line,
@@ -3921,10 +3973,10 @@ static int check_line(const char *expected_line, int nexpected_line,
 static int do_test_pprint(int test_num)
 {
 	const struct btf_raw_test *test = &pprint_test_template[test_num];
+	enum pprint_mapv_kind_t mapv_kind = test->mapv_kind;
 	struct bpf_create_map_attr create_attr = {};
 	bool ordered_map, lossless_map, percpu_map;
 	int err, ret, num_cpus, rounded_value_size;
-	struct pprint_mapv *mapv = NULL;
 	unsigned int key, nr_read_elems;
 	int map_fd = -1, btf_fd = -1;
 	unsigned int raw_btf_size;
@@ -3933,6 +3985,7 @@ static int do_test_pprint(int test_num)
 	char pin_path[255];
 	size_t line_len = 0;
 	char *line = NULL;
+	void *mapv = NULL;
 	uint8_t *raw_btf;
 	ssize_t nread;
 
@@ -3985,7 +4038,7 @@ static int do_test_pprint(int test_num)
 
 	percpu_map = test->percpu_map;
 	num_cpus = percpu_map ? bpf_num_possible_cpus() : 1;
-	rounded_value_size = round_up(sizeof(struct pprint_mapv), 8);
+	rounded_value_size = round_up(get_pprint_mapv_size(mapv_kind), 8);
 	mapv = calloc(num_cpus, rounded_value_size);
 	if (CHECK(!mapv, "mapv allocation failure")) {
 		err = -1;
@@ -3993,7 +4046,7 @@ static int do_test_pprint(int test_num)
 	}
 
 	for (key = 0; key < test->max_entries; key++) {
-		set_pprint_mapv(mapv, key, num_cpus, rounded_value_size);
+		set_pprint_mapv(mapv_kind, mapv, key, num_cpus, rounded_value_size);
 		bpf_map_update_elem(map_fd, &key, mapv, 0);
 	}
 
@@ -4017,13 +4070,13 @@ static int do_test_pprint(int test_num)
 	ordered_map = test->ordered_map;
 	lossless_map = test->lossless_map;
 	do {
-		struct pprint_mapv *cmapv;
 		ssize_t nexpected_line;
 		unsigned int next_key;
+		void *cmapv;
 		int cpu;
 
 		next_key = ordered_map ? nr_read_elems : atoi(line);
-		set_pprint_mapv(mapv, next_key, num_cpus, rounded_value_size);
+		set_pprint_mapv(mapv_kind, mapv, next_key, num_cpus, rounded_value_size);
 		cmapv = mapv;
 
 		for (cpu = 0; cpu < num_cpus; cpu++) {
@@ -4056,31 +4109,16 @@ static int do_test_pprint(int test_num)
 					break;
 			}
 
-			nexpected_line = snprintf(expected_line, sizeof(expected_line),
-						  "%s%u: {%u,0,%d,0x%x,0x%x,0x%x,"
-						  "{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s,"
-						  "%u,0x%x}\n",
-						  percpu_map ? "\tcpu" : "",
-						  percpu_map ? cpu : next_key,
-						  cmapv->ui32, cmapv->si32,
-						  cmapv->unused_bits2a,
-						  cmapv->bits28,
-						  cmapv->unused_bits2b,
-						  cmapv->ui64,
-						  cmapv->ui8a[0], cmapv->ui8a[1],
-						  cmapv->ui8a[2], cmapv->ui8a[3],
-						  cmapv->ui8a[4], cmapv->ui8a[5],
-						  cmapv->ui8a[6], cmapv->ui8a[7],
-						  pprint_enum_str[cmapv->aenum],
-						  cmapv->ui32b,
-						  cmapv->bits2c);
-
+			nexpected_line = get_pprint_expected_line(mapv_kind, expected_line,
+								  sizeof(expected_line),
+								  percpu_map, next_key,
+								  cpu, cmapv);
 			err = check_line(expected_line, nexpected_line,
 					 sizeof(expected_line), line);
 			if (err == -1)
 				goto done;
 
-			cmapv = (void *)cmapv + rounded_value_size;
+			cmapv = cmapv + rounded_value_size;
 		}
 
 		if (percpu_map) {