1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2020 Facebook */
 3#include <test_progs.h>
 4#include <bpf/btf.h>
 5
 6static char *dump_buf;
 7static size_t dump_buf_sz;
 8static FILE *dump_buf_file;
 9
10static void btf_dump_printf(void *ctx, const char *fmt, va_list args)
11{
12	vfprintf(ctx, fmt, args);
13}
14
15void 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
90cleanup:
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}