4 /* pb.h: Common parts for nanopb library.
5 * Most of these are quite low-level stuff. For the high-level interface,
6 * see pb_encode.h or pb_decode.h
9 #define NANOPB_VERSION nanopb-0.2.1-dev
11 #ifdef PB_SYSTEM_HEADER
12 #include PB_SYSTEM_HEADER
20 /* Macro for defining packed structures (compiler dependent).
21 * This just reduces memory requirements, but is not required.
23 #if defined(__GNUC__) || defined(__clang__)
24 /* For GCC and clang */
25 # define PB_PACKED_STRUCT_START
26 # define PB_PACKED_STRUCT_END
27 # define pb_packed __attribute__((packed))
28 #elif defined(__ICCARM__)
29 /* For IAR ARM compiler */
30 # define PB_PACKED_STRUCT_START _Pragma("pack(push, 1)")
31 # define PB_PACKED_STRUCT_END _Pragma("pack(pop)")
33 #elif defined(_MSC_VER)
34 /* For Microsoft Visual C++ */
35 # define PB_PACKED_STRUCT_START __pragma(pack(push, 1))
36 # define PB_PACKED_STRUCT_END __pragma(pack(pop))
39 /* Unknown compiler */
40 # define PB_PACKED_STRUCT_START
41 # define PB_PACKED_STRUCT_END
45 /* Handly macro for suppressing unreferenced-parameter compiler warnings. */
47 #define UNUSED(x) (void)(x)
50 /* Compile-time assertion, used for checking compatible compilation options.
51 * If this fails on your compiler for some reason, use #define STATIC_ASSERT
54 #define STATIC_ASSERT(COND,MSG) typedef char STATIC_ASSERT_MSG(MSG, __LINE__, __COUNTER__)[(COND)?1:-1];
55 #define STATIC_ASSERT_MSG(MSG, LINE, COUNTER) STATIC_ASSERT_MSG_(MSG, LINE, COUNTER)
56 #define STATIC_ASSERT_MSG_(MSG, LINE, COUNTER) static_assertion_##MSG##LINE##COUNTER
59 /* Number of required fields to keep track of
60 * (change here or on compiler command line). */
61 #ifndef PB_MAX_REQUIRED_FIELDS
62 #define PB_MAX_REQUIRED_FIELDS 64
65 #if PB_MAX_REQUIRED_FIELDS < 64
66 #error You should not lower PB_MAX_REQUIRED_FIELDS from the default value (64).
69 /* List of possible field types. These are used in the autogenerated code.
70 * Least-significant 4 bits tell the scalar type
71 * Most-significant 4 bits specify repeated/required/packed etc.
73 * INT32 and UINT32 are treated the same, as are (U)INT64 and (S)FIXED*
74 * These types are simply casted to correct field type when they are
75 * assigned to the memory pointer.
76 * SINT* is different, though, because it is zig-zag coded.
79 typedef uint8_t pb_type_t;
81 /************************
82 * Field contents types *
83 ************************/
86 #define PB_LTYPE_VARINT 0x00 /* int32, uint32, int64, uint64, bool, enum */
87 #define PB_LTYPE_SVARINT 0x01 /* sint32, sint64 */
88 #define PB_LTYPE_FIXED32 0x02 /* fixed32, sfixed32, float */
89 #define PB_LTYPE_FIXED64 0x03 /* fixed64, sfixed64, double */
91 /* Marker for last packable field type. */
92 #define PB_LTYPE_LAST_PACKABLE 0x03
94 /* Byte array with pre-allocated buffer.
95 * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
96 #define PB_LTYPE_BYTES 0x04
98 /* String with pre-allocated buffer.
99 * data_size is the maximum length. */
100 #define PB_LTYPE_STRING 0x05
103 * submsg_fields is pointer to field descriptions */
104 #define PB_LTYPE_SUBMESSAGE 0x06
106 /* Number of declared LTYPES */
107 #define PB_LTYPES_COUNT 7
108 #define PB_LTYPE_MASK 0x0F
110 /**************************
111 * Field repetition rules *
112 **************************/
114 #define PB_HTYPE_REQUIRED 0x00
115 #define PB_HTYPE_OPTIONAL 0x10
116 #define PB_HTYPE_REPEATED 0x20
117 #define PB_HTYPE_MASK 0x30
119 /********************
121 ********************/
123 #define PB_ATYPE_STATIC 0x00
124 #define PB_ATYPE_CALLBACK 0x40
125 #define PB_ATYPE_MASK 0xC0
127 #define PB_ATYPE(x) ((x) & PB_ATYPE_MASK)
128 #define PB_HTYPE(x) ((x) & PB_HTYPE_MASK)
129 #define PB_LTYPE(x) ((x) & PB_LTYPE_MASK)
131 /* This structure is used in auto-generated constants
132 * to specify struct fields.
133 * You can change field sizes if you need structures
134 * larger than 256 bytes or field tags larger than 256.
135 * The compiler should complain if your .proto has such
136 * structures. Fix that by defining PB_FIELD_16BIT or
139 PB_PACKED_STRUCT_START
140 typedef struct _pb_field_t pb_field_t;
143 #if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
146 uint8_t data_offset; /* Offset of field data, relative to previous field. */
147 int8_t size_offset; /* Offset of array size or has-boolean, relative to data */
148 uint8_t data_size; /* Data size in bytes for a single item */
149 uint8_t array_size; /* Maximum number of entries in array */
150 #elif defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
166 /* Field definitions for submessage
167 * OR default value for all other non-array, non-callback types
168 * If null, then field will zeroed. */
173 /* This structure is used for 'bytes' arrays.
174 * It has the number of bytes in the beginning, and after that an array.
175 * Note that actual structs used will have a different length of bytes array.
177 struct _pb_bytes_array_t {
182 typedef struct _pb_bytes_array_t pb_bytes_array_t;
184 /* This structure is used for giving the callback function.
185 * It is stored in the message structure and filled in by the method that
188 * The decoding callback will be given a limited-length stream
189 * If the wire type was string, the length is the length of the string.
190 * If the wire type was a varint/fixed32/fixed64, the length is the length
191 * of the actual value.
192 * The function may be called multiple times (especially for repeated types,
193 * but also otherwise if the message happens to contain the field multiple
196 * The encoding callback will receive the actual output stream.
197 * It should write all the data in one call, including the field tag and
198 * wire type. It can write multiple fields.
200 * The callback can be null if you want to skip a field.
202 typedef struct _pb_istream_t pb_istream_t;
203 typedef struct _pb_ostream_t pb_ostream_t;
204 typedef struct _pb_callback_t pb_callback_t;
205 struct _pb_callback_t {
206 #ifdef PB_OLD_CALLBACK_STYLE
207 /* Deprecated since nanopb-0.2.1 */
209 bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
210 bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
213 /* New function signature, which allows modifying arg contents in callback. */
215 bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
216 bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
220 /* Free arg for use by callback */
224 /* Wire types. Library user needs these only in encoder callbacks. */
232 /* These macros are used to declare pb_field_t's in the constant array. */
233 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
234 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
235 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
236 #define pb_delta_end(st, m1, m2) (int)(offsetof(st, m1) == offsetof(st, m2) \
238 : offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
239 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}
241 /* Required fields are the simplest. They just have delta (padding) from
242 * previous field end, and the size of the field. Pointer is used for
243 * submessages and default values.
245 #define PB_REQUIRED_STATIC(tag, st, m, pm, ltype, ptr) \
246 {tag, PB_ATYPE_STATIC | PB_HTYPE_REQUIRED | ltype, \
247 pb_delta_end(st, m, pm), 0, pb_membersize(st, m), 0, ptr}
249 /* Optional fields add the delta to the has_ variable. */
250 #define PB_OPTIONAL_STATIC(tag, st, m, pm, ltype, ptr) \
251 {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
252 pb_delta_end(st, m, pm), \
253 pb_delta(st, has_ ## m, m), \
254 pb_membersize(st, m), 0, ptr}
256 /* Repeated fields have a _count field and also the maximum number of entries. */
257 #define PB_REPEATED_STATIC(tag, st, m, pm, ltype, ptr) \
258 {tag, PB_ATYPE_STATIC | PB_HTYPE_REPEATED | ltype, \
259 pb_delta_end(st, m, pm), \
260 pb_delta(st, m ## _count, m), \
261 pb_membersize(st, m[0]), \
262 pb_arraysize(st, m), ptr}
264 /* Callbacks are much like required fields except with special datatype. */
265 #define PB_REQUIRED_CALLBACK(tag, st, m, pm, ltype, ptr) \
266 {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REQUIRED | ltype, \
267 pb_delta_end(st, m, pm), 0, pb_membersize(st, m), 0, ptr}
269 #define PB_OPTIONAL_CALLBACK(tag, st, m, pm, ltype, ptr) \
270 {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
271 pb_delta_end(st, m, pm), 0, pb_membersize(st, m), 0, ptr}
273 #define PB_REPEATED_CALLBACK(tag, st, m, pm, ltype, ptr) \
274 {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REPEATED | ltype, \
275 pb_delta_end(st, m, pm), 0, pb_membersize(st, m), 0, ptr}
277 /* The mapping from protobuf types to LTYPEs is done using these macros. */
278 #define PB_LTYPE_MAP_BOOL PB_LTYPE_VARINT
279 #define PB_LTYPE_MAP_BYTES PB_LTYPE_BYTES
280 #define PB_LTYPE_MAP_DOUBLE PB_LTYPE_FIXED64
281 #define PB_LTYPE_MAP_ENUM PB_LTYPE_VARINT
282 #define PB_LTYPE_MAP_FIXED32 PB_LTYPE_FIXED32
283 #define PB_LTYPE_MAP_FIXED64 PB_LTYPE_FIXED64
284 #define PB_LTYPE_MAP_FLOAT PB_LTYPE_FIXED32
285 #define PB_LTYPE_MAP_INT32 PB_LTYPE_VARINT
286 #define PB_LTYPE_MAP_INT64 PB_LTYPE_VARINT
287 #define PB_LTYPE_MAP_MESSAGE PB_LTYPE_SUBMESSAGE
288 #define PB_LTYPE_MAP_SFIXED32 PB_LTYPE_FIXED32
289 #define PB_LTYPE_MAP_SFIXED64 PB_LTYPE_FIXED64
290 #define PB_LTYPE_MAP_SINT32 PB_LTYPE_SVARINT
291 #define PB_LTYPE_MAP_SINT64 PB_LTYPE_SVARINT
292 #define PB_LTYPE_MAP_STRING PB_LTYPE_STRING
293 #define PB_LTYPE_MAP_UINT32 PB_LTYPE_VARINT
294 #define PB_LTYPE_MAP_UINT64 PB_LTYPE_VARINT
296 /* This is the actual macro used in field descriptions.
297 * It takes these arguments:
299 * - Field type: BOOL, BYTES, DOUBLE, ENUM, FIXED32, FIXED64,
300 * FLOAT, INT32, INT64, MESSAGE, SFIXED32, SFIXED64
301 * SINT32, SINT64, STRING, UINT32 or UINT64
302 * - Field rules: REQUIRED, OPTIONAL or REPEATED
303 * - Allocation: STATIC or CALLBACK
306 * - Previous field name (or field name again for first field)
307 * - Pointer to default value or submsg fields.
310 #define PB_FIELD(tag, type, rules, allocation, message, field, prevfield, ptr) \
311 PB_ ## rules ## _ ## allocation(tag, message, field, prevfield, \
312 PB_LTYPE_MAP_ ## type, ptr)
314 /* These macros are used for giving out error messages.
315 * They are mostly a debugging aid; the main error information
316 * is the true/false return value from functions.
317 * Some code space can be saved by disabling the error
318 * messages if not used.
321 #define PB_RETURN_ERROR(stream,msg) return false
322 #define PB_GET_ERROR(stream) "(errmsg disabled)"
324 #define PB_RETURN_ERROR(stream,msg) \
326 if ((stream)->errmsg == NULL) \
327 (stream)->errmsg = (msg); \
330 #define PB_GET_ERROR(stream) ((stream)->errmsg ? (stream)->errmsg : "(none)")