1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <test_progs.h>
4 #include <bpf/btf.h>
5 
6 static char *dump_buf;
7 static size_t dump_buf_sz;
8 static FILE *dump_buf_file;
9 
10 static void btf_dump_printf(void *ctx, const char *fmt, va_list args)
11 {
12 	vfprintf(ctx, fmt, args);
13 }
14 
15 void test_btf_split() {
16 	struct btf_dump *d = NULL;
17 	const struct btf_type *t;
18 	struct btf *btf1, *btf2;
19 	int str_off, i, err;
20 
21 	btf1 = btf__new_empty();
22 	if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
23 		return;
24 
25 	btf__set_pointer_size(btf1, 8); /* enforce 64-bit arch */
26 
27 	btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);	/* [1] int */
28 	btf__add_ptr(btf1, 1);				/* [2] ptr to int */
29 
30 	btf__add_struct(btf1, "s1", 4);			/* [3] struct s1 { */
31 	btf__add_field(btf1, "f1", 1, 0, 0);		/*      int f1; */
32 							/* } */
33 
34 	btf2 = btf__new_empty_split(btf1);
35 	if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
36 		goto cleanup;
37 
38 	/* pointer size should be "inherited" from main BTF */
39 	ASSERT_EQ(btf__pointer_size(btf2), 8, "inherit_ptr_sz");
40 
41 	str_off = btf__find_str(btf2, "int");
42 	ASSERT_NEQ(str_off, -ENOENT, "str_int_missing");
43 
44 	t = btf__type_by_id(btf2, 1);
45 	if (!ASSERT_OK_PTR(t, "int_type"))
46 		goto cleanup;
47 	ASSERT_EQ(btf_is_int(t), true, "int_kind");
48 	ASSERT_STREQ(btf__str_by_offset(btf2, t->name_off), "int", "int_name");
49 
50 	btf__add_struct(btf2, "s2", 16);		/* [4] struct s2 {	*/
51 	btf__add_field(btf2, "f1", 3, 0, 0);		/*      struct s1 f1;	*/
52 	btf__add_field(btf2, "f2", 1, 32, 0);		/*      int f2;		*/
53 	btf__add_field(btf2, "f3", 2, 64, 0);		/*      int *f3;	*/
54 							/* } */
55 
56 	t = btf__type_by_id(btf1, 4);
57 	ASSERT_NULL(t, "split_type_in_main");
58 
59 	t = btf__type_by_id(btf2, 4);
60 	if (!ASSERT_OK_PTR(t, "split_struct_type"))
61 		goto cleanup;
62 	ASSERT_EQ(btf_is_struct(t), true, "split_struct_kind");
63 	ASSERT_EQ(btf_vlen(t), 3, "split_struct_vlen");
64 	ASSERT_STREQ(btf__str_by_offset(btf2, t->name_off), "s2", "split_struct_name");
65 
66 	/* BTF-to-C dump of split BTF */
67 	dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
68 	if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
69 		return;
70 	d = btf_dump__new(btf2, btf_dump_printf, dump_buf_file, NULL);
71 	if (!ASSERT_OK_PTR(d, "btf_dump__new"))
72 		goto cleanup;
73 	for (i = 1; i < btf__type_cnt(btf2); i++) {
74 		err = btf_dump__dump_type(d, i);
75 		ASSERT_OK(err, "dump_type_ok");
76 	}
77 	fflush(dump_buf_file);
78 	dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
79 	ASSERT_STREQ(dump_buf,
80 "struct s1 {\n"
81 "	int f1;\n"
82 "};\n"
83 "\n"
84 "struct s2 {\n"
85 "	struct s1 f1;\n"
86 "	int f2;\n"
87 "	int *f3;\n"
88 "};\n\n", "c_dump");
89 
90 cleanup:
91 	if (dump_buf_file)
92 		fclose(dump_buf_file);
93 	free(dump_buf);
94 	btf_dump__free(d);
95 	btf__free(btf1);
96 	btf__free(btf2);
97 }
98