xref: /linux/tools/lib/bpf/btf.h (revision a35707c3d850dda0ceefb75b1b3bd191921d5765)
1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2 /* Copyright (c) 2018 Facebook */
3 /*! \file */
4 
5 #ifndef __LIBBPF_BTF_H
6 #define __LIBBPF_BTF_H
7 
8 #include <stdarg.h>
9 #include <stdbool.h>
10 #include <linux/btf.h>
11 #include <linux/types.h>
12 
13 #include "libbpf_common.h"
14 
15 #ifdef __cplusplus
16 extern "C" {
17 #endif
18 
19 #define BTF_ELF_SEC ".BTF"
20 #define BTF_EXT_ELF_SEC ".BTF.ext"
21 #define MAPS_ELF_SEC ".maps"
22 
23 struct btf;
24 struct btf_ext;
25 struct btf_type;
26 
27 struct bpf_object;
28 
29 enum btf_endianness {
30 	BTF_LITTLE_ENDIAN = 0,
31 	BTF_BIG_ENDIAN = 1,
32 };
33 
34 /**
35  * @brief **btf__free()** frees all data of a BTF object
36  * @param btf BTF object to free
37  */
38 LIBBPF_API void btf__free(struct btf *btf);
39 
40 /**
41  * @brief **btf__new()** creates a new instance of a BTF object from the raw
42  * bytes of an ELF's BTF section
43  * @param data raw bytes
44  * @param size number of bytes passed in `data`
45  * @return new BTF object instance which has to be eventually freed with
46  * **btf__free()**
47  *
48  * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
49  * error code from such a pointer `libbpf_get_error()` should be used. If
50  * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
51  * returned on error instead. In both cases thread-local `errno` variable is
52  * always set to error code as well.
53  */
54 LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
55 
56 /**
57  * @brief **btf__new_split()** create a new instance of a BTF object from the
58  * provided raw data bytes. It takes another BTF instance, **base_btf**, which
59  * serves as a base BTF, which is extended by types in a newly created BTF
60  * instance
61  * @param data raw bytes
62  * @param size length of raw bytes
63  * @param base_btf the base BTF object
64  * @return new BTF object instance which has to be eventually freed with
65  * **btf__free()**
66  *
67  * If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and
68  * creates non-split BTF.
69  *
70  * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
71  * error code from such a pointer `libbpf_get_error()` should be used. If
72  * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
73  * returned on error instead. In both cases thread-local `errno` variable is
74  * always set to error code as well.
75  */
76 LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
77 
78 /**
79  * @brief **btf__new_empty()** creates an empty BTF object.  Use
80  * `btf__add_*()` to populate such BTF object.
81  * @return new BTF object instance which has to be eventually freed with
82  * **btf__free()**
83  *
84  * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
85  * error code from such a pointer `libbpf_get_error()` should be used. If
86  * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
87  * returned on error instead. In both cases thread-local `errno` variable is
88  * always set to error code as well.
89  */
90 LIBBPF_API struct btf *btf__new_empty(void);
91 
92 /**
93  * @brief **btf__new_empty_split()** creates an unpopulated BTF object from an
94  * ELF BTF section except with a base BTF on top of which split BTF should be
95  * based
96  * @return new BTF object instance which has to be eventually freed with
97  * **btf__free()**
98  *
99  * If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to
100  * `btf__new_empty()` and creates non-split BTF.
101  *
102  * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
103  * error code from such a pointer `libbpf_get_error()` should be used. If
104  * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
105  * returned on error instead. In both cases thread-local `errno` variable is
106  * always set to error code as well.
107  */
108 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
109 
110 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
111 LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
112 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
113 LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
114 LIBBPF_API struct btf *btf__parse_raw(const char *path);
115 LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
116 
117 LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
118 LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
119 LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
120 
121 LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
122 LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
123 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
124 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
125 
126 LIBBPF_DEPRECATED_SINCE(0, 6, "intended for internal libbpf use only")
127 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
128 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
129 LIBBPF_API int btf__load(struct btf *btf);
130 LIBBPF_API int btf__load_into_kernel(struct btf *btf);
131 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
132 				   const char *type_name);
133 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
134 					const char *type_name, __u32 kind);
135 LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__type_cnt() instead; note that btf__get_nr_types() == btf__type_cnt() - 1")
136 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
137 LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);
138 LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
139 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
140 						  __u32 id);
141 LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
142 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
143 LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
144 LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
145 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
146 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
147 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
148 LIBBPF_API int btf__fd(const struct btf *btf);
149 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
150 LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);
151 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
152 LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
153 LIBBPF_DEPRECATED_SINCE(0, 7, "this API is not necessary when BTF-defined maps are used")
154 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
155 				    __u32 expected_key_size,
156 				    __u32 expected_value_size,
157 				    __u32 *key_type_id, __u32 *value_type_id);
158 
159 LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size);
160 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
161 LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size);
162 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_func_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
163 int btf_ext__reloc_func_info(const struct btf *btf,
164 			     const struct btf_ext *btf_ext,
165 			     const char *sec_name, __u32 insns_cnt,
166 			     void **func_info, __u32 *cnt);
167 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_line_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
168 int btf_ext__reloc_line_info(const struct btf *btf,
169 			     const struct btf_ext *btf_ext,
170 			     const char *sec_name, __u32 insns_cnt,
171 			     void **line_info, __u32 *cnt);
172 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_func_info is deprecated; write custom func_info parsing to fetch rec_size")
173 __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
174 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_line_info is deprecated; write custom line_info parsing to fetch rec_size")
175 __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
176 
177 LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
178 LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
179 LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf,
180 			     const struct btf_type *src_type);
181 /**
182  * @brief **btf__add_btf()** appends all the BTF types from *src_btf* into *btf*
183  * @param btf BTF object which all the BTF types and strings are added to
184  * @param src_btf BTF object which all BTF types and referenced strings are copied from
185  * @return BTF type ID of the first appended BTF type, or negative error code
186  *
187  * **btf__add_btf()** can be used to simply and efficiently append the entire
188  * contents of one BTF object to another one. All the BTF type data is copied
189  * over, all referenced type IDs are adjusted by adding a necessary ID offset.
190  * Only strings referenced from BTF types are copied over and deduplicated, so
191  * if there were some unused strings in *src_btf*, those won't be copied over,
192  * which is consistent with the general string deduplication semantics of BTF
193  * writing APIs.
194  *
195  * If any error is encountered during this process, the contents of *btf* is
196  * left intact, which means that **btf__add_btf()** follows the transactional
197  * semantics and the operation as a whole is all-or-nothing.
198  *
199  * *src_btf* has to be non-split BTF, as of now copying types from split BTF
200  * is not supported and will result in -ENOTSUP error code returned.
201  */
202 LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf);
203 
204 LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
205 LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz);
206 LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
207 LIBBPF_API int btf__add_array(struct btf *btf,
208 			      int index_type_id, int elem_type_id, __u32 nr_elems);
209 /* struct/union construction APIs */
210 LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
211 LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
212 LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
213 			      __u32 bit_offset, __u32 bit_size);
214 
215 /* enum construction APIs */
216 LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
217 LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
218 
219 enum btf_fwd_kind {
220 	BTF_FWD_STRUCT = 0,
221 	BTF_FWD_UNION = 1,
222 	BTF_FWD_ENUM = 2,
223 };
224 
225 LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
226 LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
227 LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
228 LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
229 LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
230 LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id);
231 
232 /* func and func_proto construction APIs */
233 LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
234 			     enum btf_func_linkage linkage, int proto_type_id);
235 LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
236 LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
237 
238 /* var & datasec construction APIs */
239 LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
240 LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
241 LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
242 					 __u32 offset, __u32 byte_sz);
243 
244 /* tag construction API */
245 LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
246 			    int component_idx);
247 
248 struct btf_dedup_opts {
249 	size_t sz;
250 	/* optional .BTF.ext info to dedup along the main BTF info */
251 	struct btf_ext *btf_ext;
252 	/* force hash collisions (used for testing) */
253 	bool force_collisions;
254 	size_t :0;
255 };
256 #define btf_dedup_opts__last_field force_collisions
257 
258 LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts);
259 
260 LIBBPF_API int btf__dedup_v0_6_0(struct btf *btf, const struct btf_dedup_opts *opts);
261 
262 LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__dedup() instead")
263 LIBBPF_API int btf__dedup_deprecated(struct btf *btf, struct btf_ext *btf_ext, const void *opts);
264 #define btf__dedup(...) ___libbpf_overload(___btf_dedup, __VA_ARGS__)
265 #define ___btf_dedup3(btf, btf_ext, opts) btf__dedup_deprecated(btf, btf_ext, opts)
266 #define ___btf_dedup2(btf, opts) btf__dedup(btf, opts)
267 
268 struct btf_dump;
269 
270 struct btf_dump_opts {
271 	union {
272 		size_t sz;
273 		void *ctx; /* DEPRECATED: will be gone in v1.0 */
274 	};
275 };
276 
277 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
278 
279 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
280 					  btf_dump_printf_fn_t printf_fn,
281 					  void *ctx,
282 					  const struct btf_dump_opts *opts);
283 
284 LIBBPF_API struct btf_dump *btf_dump__new_v0_6_0(const struct btf *btf,
285 						 btf_dump_printf_fn_t printf_fn,
286 						 void *ctx,
287 						 const struct btf_dump_opts *opts);
288 
289 LIBBPF_API struct btf_dump *btf_dump__new_deprecated(const struct btf *btf,
290 						     const struct btf_ext *btf_ext,
291 						     const struct btf_dump_opts *opts,
292 						     btf_dump_printf_fn_t printf_fn);
293 
294 /* Choose either btf_dump__new() or btf_dump__new_deprecated() based on the
295  * type of 4th argument. If it's btf_dump's print callback, use deprecated
296  * API; otherwise, choose the new btf_dump__new(). ___libbpf_override()
297  * doesn't work here because both variants have 4 input arguments.
298  *
299  * (void *) casts are necessary to avoid compilation warnings about type
300  * mismatches, because even though __builtin_choose_expr() only ever evaluates
301  * one side the other side still has to satisfy type constraints (this is
302  * compiler implementation limitation which might be lifted eventually,
303  * according to the documentation). So passing struct btf_ext in place of
304  * btf_dump_printf_fn_t would be generating compilation warning.  Casting to
305  * void * avoids this issue.
306  *
307  * Also, two type compatibility checks for a function and function pointer are
308  * required because passing function reference into btf_dump__new() as
309  * btf_dump__new(..., my_callback, ...) and as btf_dump__new(...,
310  * &my_callback, ...) (not explicit ampersand in the latter case) actually
311  * differs as far as __builtin_types_compatible_p() is concerned. Thus two
312  * checks are combined to detect callback argument.
313  *
314  * The rest works just like in case of ___libbpf_override() usage with symbol
315  * versioning.
316  *
317  * C++ compilers don't support __builtin_types_compatible_p(), so at least
318  * don't screw up compilation for them and let C++ users pick btf_dump__new
319  * vs btf_dump__new_deprecated explicitly.
320  */
321 #ifndef __cplusplus
322 #define btf_dump__new(a1, a2, a3, a4) __builtin_choose_expr(				\
323 	__builtin_types_compatible_p(typeof(a4), btf_dump_printf_fn_t) ||		\
324 	__builtin_types_compatible_p(typeof(a4), void(void *, const char *, va_list)),	\
325 	btf_dump__new_deprecated((void *)a1, (void *)a2, (void *)a3, (void *)a4),	\
326 	btf_dump__new((void *)a1, (void *)a2, (void *)a3, (void *)a4))
327 #endif
328 
329 LIBBPF_API void btf_dump__free(struct btf_dump *d);
330 
331 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
332 
333 struct btf_dump_emit_type_decl_opts {
334 	/* size of this struct, for forward/backward compatiblity */
335 	size_t sz;
336 	/* optional field name for type declaration, e.g.:
337 	 * - struct my_struct <FNAME>
338 	 * - void (*<FNAME>)(int)
339 	 * - char (*<FNAME>)[123]
340 	 */
341 	const char *field_name;
342 	/* extra indentation level (in number of tabs) to emit for multi-line
343 	 * type declarations (e.g., anonymous struct); applies for lines
344 	 * starting from the second one (first line is assumed to have
345 	 * necessary indentation already
346 	 */
347 	int indent_level;
348 	/* strip all the const/volatile/restrict mods */
349 	bool strip_mods;
350 	size_t :0;
351 };
352 #define btf_dump_emit_type_decl_opts__last_field strip_mods
353 
354 LIBBPF_API int
355 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
356 			 const struct btf_dump_emit_type_decl_opts *opts);
357 
358 
359 struct btf_dump_type_data_opts {
360 	/* size of this struct, for forward/backward compatibility */
361 	size_t sz;
362 	const char *indent_str;
363 	int indent_level;
364 	/* below match "show" flags for bpf_show_snprintf() */
365 	bool compact;		/* no newlines/indentation */
366 	bool skip_names;	/* skip member/type names */
367 	bool emit_zeroes;	/* show 0-valued fields */
368 	size_t :0;
369 };
370 #define btf_dump_type_data_opts__last_field emit_zeroes
371 
372 LIBBPF_API int
373 btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
374 			 const void *data, size_t data_sz,
375 			 const struct btf_dump_type_data_opts *opts);
376 
377 /*
378  * A set of helpers for easier BTF types handling.
379  *
380  * The inline functions below rely on constants from the kernel headers which
381  * may not be available for applications including this header file. To avoid
382  * compilation errors, we define all the constants here that were added after
383  * the initial introduction of the BTF_KIND* constants.
384  */
385 #ifndef BTF_KIND_FUNC
386 #define BTF_KIND_FUNC		12	/* Function	*/
387 #define BTF_KIND_FUNC_PROTO	13	/* Function Proto	*/
388 #endif
389 #ifndef BTF_KIND_VAR
390 #define BTF_KIND_VAR		14	/* Variable	*/
391 #define BTF_KIND_DATASEC	15	/* Section	*/
392 #endif
393 #ifndef BTF_KIND_FLOAT
394 #define BTF_KIND_FLOAT		16	/* Floating point	*/
395 #endif
396 /* The kernel header switched to enums, so these two were never #defined */
397 #define BTF_KIND_DECL_TAG	17	/* Decl Tag */
398 #define BTF_KIND_TYPE_TAG	18	/* Type Tag */
399 
400 static inline __u16 btf_kind(const struct btf_type *t)
401 {
402 	return BTF_INFO_KIND(t->info);
403 }
404 
405 static inline __u16 btf_vlen(const struct btf_type *t)
406 {
407 	return BTF_INFO_VLEN(t->info);
408 }
409 
410 static inline bool btf_kflag(const struct btf_type *t)
411 {
412 	return BTF_INFO_KFLAG(t->info);
413 }
414 
415 static inline bool btf_is_void(const struct btf_type *t)
416 {
417 	return btf_kind(t) == BTF_KIND_UNKN;
418 }
419 
420 static inline bool btf_is_int(const struct btf_type *t)
421 {
422 	return btf_kind(t) == BTF_KIND_INT;
423 }
424 
425 static inline bool btf_is_ptr(const struct btf_type *t)
426 {
427 	return btf_kind(t) == BTF_KIND_PTR;
428 }
429 
430 static inline bool btf_is_array(const struct btf_type *t)
431 {
432 	return btf_kind(t) == BTF_KIND_ARRAY;
433 }
434 
435 static inline bool btf_is_struct(const struct btf_type *t)
436 {
437 	return btf_kind(t) == BTF_KIND_STRUCT;
438 }
439 
440 static inline bool btf_is_union(const struct btf_type *t)
441 {
442 	return btf_kind(t) == BTF_KIND_UNION;
443 }
444 
445 static inline bool btf_is_composite(const struct btf_type *t)
446 {
447 	__u16 kind = btf_kind(t);
448 
449 	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
450 }
451 
452 static inline bool btf_is_enum(const struct btf_type *t)
453 {
454 	return btf_kind(t) == BTF_KIND_ENUM;
455 }
456 
457 static inline bool btf_is_fwd(const struct btf_type *t)
458 {
459 	return btf_kind(t) == BTF_KIND_FWD;
460 }
461 
462 static inline bool btf_is_typedef(const struct btf_type *t)
463 {
464 	return btf_kind(t) == BTF_KIND_TYPEDEF;
465 }
466 
467 static inline bool btf_is_volatile(const struct btf_type *t)
468 {
469 	return btf_kind(t) == BTF_KIND_VOLATILE;
470 }
471 
472 static inline bool btf_is_const(const struct btf_type *t)
473 {
474 	return btf_kind(t) == BTF_KIND_CONST;
475 }
476 
477 static inline bool btf_is_restrict(const struct btf_type *t)
478 {
479 	return btf_kind(t) == BTF_KIND_RESTRICT;
480 }
481 
482 static inline bool btf_is_mod(const struct btf_type *t)
483 {
484 	__u16 kind = btf_kind(t);
485 
486 	return kind == BTF_KIND_VOLATILE ||
487 	       kind == BTF_KIND_CONST ||
488 	       kind == BTF_KIND_RESTRICT ||
489 	       kind == BTF_KIND_TYPE_TAG;
490 }
491 
492 static inline bool btf_is_func(const struct btf_type *t)
493 {
494 	return btf_kind(t) == BTF_KIND_FUNC;
495 }
496 
497 static inline bool btf_is_func_proto(const struct btf_type *t)
498 {
499 	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
500 }
501 
502 static inline bool btf_is_var(const struct btf_type *t)
503 {
504 	return btf_kind(t) == BTF_KIND_VAR;
505 }
506 
507 static inline bool btf_is_datasec(const struct btf_type *t)
508 {
509 	return btf_kind(t) == BTF_KIND_DATASEC;
510 }
511 
512 static inline bool btf_is_float(const struct btf_type *t)
513 {
514 	return btf_kind(t) == BTF_KIND_FLOAT;
515 }
516 
517 static inline bool btf_is_decl_tag(const struct btf_type *t)
518 {
519 	return btf_kind(t) == BTF_KIND_DECL_TAG;
520 }
521 
522 static inline bool btf_is_type_tag(const struct btf_type *t)
523 {
524 	return btf_kind(t) == BTF_KIND_TYPE_TAG;
525 }
526 
527 static inline __u8 btf_int_encoding(const struct btf_type *t)
528 {
529 	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
530 }
531 
532 static inline __u8 btf_int_offset(const struct btf_type *t)
533 {
534 	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
535 }
536 
537 static inline __u8 btf_int_bits(const struct btf_type *t)
538 {
539 	return BTF_INT_BITS(*(__u32 *)(t + 1));
540 }
541 
542 static inline struct btf_array *btf_array(const struct btf_type *t)
543 {
544 	return (struct btf_array *)(t + 1);
545 }
546 
547 static inline struct btf_enum *btf_enum(const struct btf_type *t)
548 {
549 	return (struct btf_enum *)(t + 1);
550 }
551 
552 static inline struct btf_member *btf_members(const struct btf_type *t)
553 {
554 	return (struct btf_member *)(t + 1);
555 }
556 
557 /* Get bit offset of a member with specified index. */
558 static inline __u32 btf_member_bit_offset(const struct btf_type *t,
559 					  __u32 member_idx)
560 {
561 	const struct btf_member *m = btf_members(t) + member_idx;
562 	bool kflag = btf_kflag(t);
563 
564 	return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
565 }
566 /*
567  * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
568  * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
569  */
570 static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
571 					     __u32 member_idx)
572 {
573 	const struct btf_member *m = btf_members(t) + member_idx;
574 	bool kflag = btf_kflag(t);
575 
576 	return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
577 }
578 
579 static inline struct btf_param *btf_params(const struct btf_type *t)
580 {
581 	return (struct btf_param *)(t + 1);
582 }
583 
584 static inline struct btf_var *btf_var(const struct btf_type *t)
585 {
586 	return (struct btf_var *)(t + 1);
587 }
588 
589 static inline struct btf_var_secinfo *
590 btf_var_secinfos(const struct btf_type *t)
591 {
592 	return (struct btf_var_secinfo *)(t + 1);
593 }
594 
595 struct btf_decl_tag;
596 static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t)
597 {
598 	return (struct btf_decl_tag *)(t + 1);
599 }
600 
601 #ifdef __cplusplus
602 } /* extern "C" */
603 #endif
604 
605 #endif /* __LIBBPF_BTF_H */
606