selftests/bpf: Add set test to resolve_btfids

Adding test to for sets resolve_btfids. We're checking that
testing set gets properly resolved and sorted.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-15-jolsa@kernel.org

tools/testing/selftests/bpf/prog_tests/resolve_btfids.c

@@ -47,6 +47,15 @@ BTF_ID(struct,  S)
 BTF_ID(union,   U)
 BTF_ID(func,    func)
 
+BTF_SET_START(test_set)
+BTF_ID(typedef, S)
+BTF_ID(typedef, T)
+BTF_ID(typedef, U)
+BTF_ID(struct,  S)
+BTF_ID(union,   U)
+BTF_ID(func,    func)
+BTF_SET_END(test_set)
+
 static int
 __resolve_symbol(struct btf *btf, int type_id)
 {
@@ -116,12 +125,40 @@ int test_resolve_btfids(void)
 	 */
 	for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
 		test_list = test_lists[j];
-		for (i = 0; i < ARRAY_SIZE(test_symbols) && !ret; i++) {
+		for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
 			ret = CHECK(test_list[i] != test_symbols[i].id,
 				    "id_check",
 				    "wrong ID for %s (%d != %d)\n",
 				    test_symbols[i].name,
 				    test_list[i], test_symbols[i].id);
+			if (ret)
+				return ret;
+		}
+	}
+
+	/* Check BTF_SET_START(test_set) IDs */
+	for (i = 0; i < test_set.cnt; i++) {
+		bool found = false;
+
+		for (j = 0; j < ARRAY_SIZE(test_symbols); j++) {
+			if (test_symbols[j].id != test_set.ids[i])
+				continue;
+			found = true;
+			break;
+		}
+
+		ret = CHECK(!found, "id_check",
+			    "ID %d not found in test_symbols\n",
+			    test_set.ids[i]);
+		if (ret)
+			break;
+
+		if (i > 0) {
+			ret = CHECK(test_set.ids[i - 1] > test_set.ids[i],
+				    "sort_check",
+				    "test_set is not sorted\n");
+			if (ret)
+				break;
 		}
 	}