pb.h

00001 /* Common parts of the nanopb library. Most of these are quite low-level
00002  * stuff. For the high-level interface, see pb_encode.h and pb_decode.h.
00003  */
00004 
00005 #ifndef _PB_H_
00006 #define _PB_H_
00007 
00008 /*****************************************************************
00009  * Nanopb compilation time options. You can change these here by *
00010  * uncommenting the lines, or on the compiler command line.      *
00011  *****************************************************************/
00012 
00013 /* Define this if your CPU architecture is big endian, i.e. it
00014  * stores the most-significant byte first. */
00015 /* #define __BIG_ENDIAN__ 1 */
00016 
00017 /* Increase the number of required fields that are tracked.
00018  * A compiler warning will tell if you need this. */
00019 /* #define PB_MAX_REQUIRED_FIELDS 256 */
00020 
00021 /* Add support for tag numbers > 255 and fields larger than 255 bytes. */
00022 /* #define PB_FIELD_16BIT 1 */
00023 
00024 /* Add support for tag numbers > 65536 and fields larger than 65536 bytes. */
00025 /* #define PB_FIELD_32BIT 1 */
00026 
00027 /* Disable support for error messages in order to save some code space. */
00028 /* #define PB_NO_ERRMSG 1 */
00029 
00030 /* Disable support for custom streams (support only memory buffers). */
00031 /* #define PB_BUFFER_ONLY 1 */
00032 
00033 /* Switch back to the old-style callback function signature.
00034  * This was the default until nanopb-0.2.1. */
00035 /* #define PB_OLD_CALLBACK_STYLE */
00036 
00037 
00038 /******************************************************************
00039  * You usually don't need to change anything below this line.     *
00040  * Feel free to look around and use the defined macros, though.   *
00041  ******************************************************************/
00042 
00043 
00044 /* Version of the nanopb library. Just in case you want to check it in
00045  * your own program. */
00046 #define NANOPB_VERSION nanopb-0.2.5
00047 
00048 /* Include all the system headers needed by nanopb. You will need the
00049  * definitions of the following:
00050  * - strlen, memcpy, memset functions
00051  * - [u]int8_t, [u]int16_t, [u]int32_t, [u]int64_t
00052  * - size_t
00053  * - bool
00054  *
00055  * If you don't have the standard header files, you can instead provide
00056  * a custom header that defines or includes all this. In that case,
00057  * define PB_SYSTEM_HEADER to the path of this file.
00058  */
00059 #ifdef PB_SYSTEM_HEADER
00060 #include PB_SYSTEM_HEADER
00061 #else
00062 #include <stdint.h>
00063 #include <stddef.h>
00064 #include <stdbool.h>
00065 #include <string.h>
00066 #endif
00067 
00068 /* Macro for defining packed structures (compiler dependent).
00069  * This just reduces memory requirements, but is not required.
00070  */
00071 #if defined(__GNUC__) || defined(__clang__)
00072     /* For GCC and clang */
00073 #   define PB_PACKED_STRUCT_START
00074 #   define PB_PACKED_STRUCT_END
00075 #   define pb_packed __attribute__((packed))
00076 #elif defined(__ICCARM__)
00077     /* For IAR ARM compiler */
00078 #   define PB_PACKED_STRUCT_START _Pragma("pack(push, 1)")
00079 #   define PB_PACKED_STRUCT_END _Pragma("pack(pop)")
00080 #   define pb_packed
00081 #elif defined(_MSC_VER) && (_MSC_VER >= 1500)
00082     /* For Microsoft Visual C++ */
00083 #   define PB_PACKED_STRUCT_START __pragma(pack(push, 1))
00084 #   define PB_PACKED_STRUCT_END __pragma(pack(pop))
00085 #   define pb_packed
00086 #else
00087     /* Unknown compiler */
00088 #   define PB_PACKED_STRUCT_START
00089 #   define PB_PACKED_STRUCT_END
00090 #   define pb_packed
00091 #endif
00092 
00093 /* Handly macro for suppressing unreferenced-parameter compiler warnings. */
00094 #ifndef UNUSED
00095 #define UNUSED(x) (void)(x)
00096 #endif
00097 
00098 /* Compile-time assertion, used for checking compatible compilation options.
00099  * If this fails on your compiler for some reason, use #define STATIC_ASSERT
00100  * to disable it. */
00101 #ifndef STATIC_ASSERT
00102 #define STATIC_ASSERT(COND,MSG) typedef char STATIC_ASSERT_MSG(MSG, __LINE__, __COUNTER__)[(COND)?1:-1];
00103 #define STATIC_ASSERT_MSG(MSG, LINE, COUNTER) STATIC_ASSERT_MSG_(MSG, LINE, COUNTER)
00104 #define STATIC_ASSERT_MSG_(MSG, LINE, COUNTER) static_assertion_##MSG##LINE##COUNTER
00105 #endif
00106 
00107 /* Number of required fields to keep track of. */
00108 #ifndef PB_MAX_REQUIRED_FIELDS
00109 #define PB_MAX_REQUIRED_FIELDS 64
00110 #endif
00111 
00112 #if PB_MAX_REQUIRED_FIELDS < 64
00113 #error You should not lower PB_MAX_REQUIRED_FIELDS from the default value (64).
00114 #endif
00115 
00116 /* List of possible field types. These are used in the autogenerated code.
00117  * Least-significant 4 bits tell the scalar type
00118  * Most-significant 4 bits specify repeated/required/packed etc.
00119  */
00120 
00121 typedef uint8_t pb_type_t;
00122 
00123 /**** Field data types ****/
00124 
00125 /* Numeric types */
00126 #define PB_LTYPE_VARINT  0x00 /* int32, int64, enum, bool */
00127 #define PB_LTYPE_UVARINT 0x01 /* uint32, uint64 */
00128 #define PB_LTYPE_SVARINT 0x02 /* sint32, sint64 */
00129 #define PB_LTYPE_FIXED32 0x03 /* fixed32, sfixed32, float */
00130 #define PB_LTYPE_FIXED64 0x04 /* fixed64, sfixed64, double */
00131 
00132 /* Marker for last packable field type. */
00133 #define PB_LTYPE_LAST_PACKABLE 0x04
00134 
00135 /* Byte array with pre-allocated buffer.
00136  * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
00137 #define PB_LTYPE_BYTES 0x05
00138 
00139 /* String with pre-allocated buffer.
00140  * data_size is the maximum length. */
00141 #define PB_LTYPE_STRING 0x06
00142 
00143 /* Submessage
00144  * submsg_fields is pointer to field descriptions */
00145 #define PB_LTYPE_SUBMESSAGE 0x07
00146 
00147 /* Extension pseudo-field
00148  * The field contains a pointer to pb_extension_t */
00149 #define PB_LTYPE_EXTENSION 0x08
00150 
00151 /* Number of declared LTYPES */
00152 #define PB_LTYPES_COUNT 9
00153 #define PB_LTYPE_MASK 0x0F
00154 
00155 /**** Field repetition rules ****/
00156 
00157 #define PB_HTYPE_REQUIRED 0x00
00158 #define PB_HTYPE_OPTIONAL 0x10
00159 #define PB_HTYPE_REPEATED 0x20
00160 #define PB_HTYPE_MASK     0x30
00161 
00162 /**** Field allocation types ****/
00163  
00164 #define PB_ATYPE_STATIC   0x00
00165 #define PB_ATYPE_POINTER  0x80
00166 #define PB_ATYPE_CALLBACK 0x40
00167 #define PB_ATYPE_MASK     0xC0
00168 
00169 #define PB_ATYPE(x) ((x) & PB_ATYPE_MASK)
00170 #define PB_HTYPE(x) ((x) & PB_HTYPE_MASK)
00171 #define PB_LTYPE(x) ((x) & PB_LTYPE_MASK)
00172 
00173 /* Data type used for storing sizes of struct fields
00174  * and array counts.
00175  */
00176 #if defined(PB_FIELD_32BIT)
00177     typedef uint32_t pb_size_t;
00178     typedef int32_t pb_ssize_t;
00179 #elif defined(PB_FIELD_16BIT)
00180     typedef uint16_t pb_size_t;
00181     typedef int16_t pb_ssize_t;
00182 #else
00183     typedef uint8_t pb_size_t;
00184     typedef int8_t pb_ssize_t;
00185 #endif
00186 
00187 /* This structure is used in auto-generated constants
00188  * to specify struct fields.
00189  * You can change field sizes if you need structures
00190  * larger than 256 bytes or field tags larger than 256.
00191  * The compiler should complain if your .proto has such
00192  * structures. Fix that by defining PB_FIELD_16BIT or
00193  * PB_FIELD_32BIT.
00194  */
00195 PB_PACKED_STRUCT_START
00196 typedef struct _pb_field_t pb_field_t;
00197 struct _pb_field_t {
00198     pb_size_t tag;
00199     pb_type_t type;
00200     pb_size_t data_offset; /* Offset of field data, relative to previous field. */
00201     pb_ssize_t size_offset; /* Offset of array size or has-boolean, relative to data */
00202     pb_size_t data_size; /* Data size in bytes for a single item */
00203     pb_size_t array_size; /* Maximum number of entries in array */
00204     
00205     /* Field definitions for submessage
00206      * OR default value for all other non-array, non-callback types
00207      * If null, then field will zeroed. */
00208     const void *ptr;
00209 } pb_packed;
00210 PB_PACKED_STRUCT_END
00211 
00212 /* Make sure that the standard integer types are of the expected sizes.
00213  * All kinds of things may break otherwise.. atleast all fixed* types. */
00214 STATIC_ASSERT(sizeof(int8_t) == 1, INT8_T_WRONG_SIZE)
00215 STATIC_ASSERT(sizeof(uint8_t) == 1, UINT8_T_WRONG_SIZE)
00216 STATIC_ASSERT(sizeof(int16_t) == 2, INT16_T_WRONG_SIZE)
00217 STATIC_ASSERT(sizeof(uint16_t) == 2, UINT16_T_WRONG_SIZE)
00218 STATIC_ASSERT(sizeof(int32_t) == 4, INT32_T_WRONG_SIZE)
00219 STATIC_ASSERT(sizeof(uint32_t) == 4, UINT32_T_WRONG_SIZE)
00220 STATIC_ASSERT(sizeof(int64_t) == 8, INT64_T_WRONG_SIZE)
00221 STATIC_ASSERT(sizeof(uint64_t) == 8, UINT64_T_WRONG_SIZE)
00222 
00223 /* This structure is used for 'bytes' arrays.
00224  * It has the number of bytes in the beginning, and after that an array.
00225  * Note that actual structs used will have a different length of bytes array.
00226  */
00227 struct _pb_bytes_array_t {
00228     size_t size;
00229     uint8_t bytes[1];
00230 };
00231 typedef struct _pb_bytes_array_t pb_bytes_array_t;
00232 
00233 /* Same, except for pointer-type fields. There is no need to variable struct
00234  * length in this case.
00235  */
00236 struct _pb_bytes_ptr_t {
00237     size_t size;
00238     uint8_t *bytes;
00239 };
00240 typedef struct _pb_bytes_ptr_t pb_bytes_ptr_t;
00241 
00242 /* This structure is used for giving the callback function.
00243  * It is stored in the message structure and filled in by the method that
00244  * calls pb_decode.
00245  *
00246  * The decoding callback will be given a limited-length stream
00247  * If the wire type was string, the length is the length of the string.
00248  * If the wire type was a varint/fixed32/fixed64, the length is the length
00249  * of the actual value.
00250  * The function may be called multiple times (especially for repeated types,
00251  * but also otherwise if the message happens to contain the field multiple
00252  * times.)
00253  *
00254  * The encoding callback will receive the actual output stream.
00255  * It should write all the data in one call, including the field tag and
00256  * wire type. It can write multiple fields.
00257  *
00258  * The callback can be null if you want to skip a field.
00259  */
00260 typedef struct _pb_istream_t pb_istream_t;
00261 typedef struct _pb_ostream_t pb_ostream_t;
00262 typedef struct _pb_callback_t pb_callback_t;
00263 struct _pb_callback_t {
00264 #ifdef PB_OLD_CALLBACK_STYLE
00265     /* Deprecated since nanopb-0.2.1 */
00266     union {
00267         bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
00268         bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
00269     } funcs;
00270 #else
00271     /* New function signature, which allows modifying arg contents in callback. */
00272     union {
00273         bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
00274         bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
00275     } funcs;
00276 #endif    
00277     
00278     /* Free arg for use by callback */
00279     void *arg;
00280 };
00281 
00282 /* Wire types. Library user needs these only in encoder callbacks. */
00283 typedef enum {
00284     PB_WT_VARINT = 0,
00285     PB_WT_64BIT  = 1,
00286     PB_WT_STRING = 2,
00287     PB_WT_32BIT  = 5
00288 } pb_wire_type_t;
00289 
00290 /* Structure for defining the handling of unknown/extension fields.
00291  * Usually the pb_extension_type_t structure is automatically generated,
00292  * while the pb_extension_t structure is created by the user. However,
00293  * if you want to catch all unknown fields, you can also create a custom
00294  * pb_extension_type_t with your own callback.
00295  */
00296 typedef struct _pb_extension_type_t pb_extension_type_t;
00297 typedef struct _pb_extension_t pb_extension_t;
00298 struct _pb_extension_type_t {
00299     /* Called for each unknown field in the message.
00300      * If you handle the field, read off all of its data and return true.
00301      * If you do not handle the field, do not read anything and return true.
00302      * If you run into an error, return false.
00303      * Set to NULL for default handler.
00304      */
00305     bool (*decode)(pb_istream_t *stream, pb_extension_t *extension,
00306                    uint32_t tag, pb_wire_type_t wire_type);
00307     
00308     /* Called once after all regular fields have been encoded.
00309      * If you have something to write, do so and return true.
00310      * If you do not have anything to write, just return true.
00311      * If you run into an error, return false.
00312      * Set to NULL for default handler.
00313      */
00314     bool (*encode)(pb_ostream_t *stream, const pb_extension_t *extension);
00315     
00316     /* Free field for use by the callback. */
00317     const void *arg;
00318 };
00319 
00320 struct _pb_extension_t {
00321     /* Type describing the extension field. Usually you'll initialize
00322      * this to a pointer to the automatically generated structure. */
00323     const pb_extension_type_t *type;
00324     
00325     /* Destination for the decoded data. This must match the datatype
00326      * of the extension field. */
00327     void *dest;
00328     
00329     /* Pointer to the next extension handler, or NULL.
00330      * If this extension does not match a field, the next handler is
00331      * automatically called. */
00332     pb_extension_t *next;
00333 };
00334 
00335 /* These macros are used to declare pb_field_t's in the constant array. */
00336 /* Size of a structure member, in bytes. */
00337 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
00338 /* Number of entries in an array. */
00339 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
00340 /* Delta from start of one member to the start of another member. */
00341 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
00342 /* Marks the end of the field list */
00343 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}
00344 
00345 /* Macros for filling in the data_offset field */
00346 /* data_offset for first field in a message */
00347 #define PB_DATAOFFSET_FIRST(st, m1, m2) (offsetof(st, m1))
00348 /* data_offset for subsequent fields */
00349 #define PB_DATAOFFSET_OTHER(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
00350 /* Choose first/other based on m1 == m2 (deprecated, remains for backwards compatibility) */
00351 #define PB_DATAOFFSET_CHOOSE(st, m1, m2) (int)(offsetof(st, m1) == offsetof(st, m2) \
00352                                   ? PB_DATAOFFSET_FIRST(st, m1, m2) \
00353                                   : PB_DATAOFFSET_OTHER(st, m1, m2))
00354 
00355 /* Required fields are the simplest. They just have delta (padding) from
00356  * previous field end, and the size of the field. Pointer is used for
00357  * submessages and default values.
00358  */
00359 #define PB_REQUIRED_STATIC(tag, st, m, fd, ltype, ptr) \
00360     {tag, PB_ATYPE_STATIC | PB_HTYPE_REQUIRED | ltype, \
00361     fd, 0, pb_membersize(st, m), 0, ptr}
00362 
00363 /* Optional fields add the delta to the has_ variable. */
00364 #define PB_OPTIONAL_STATIC(tag, st, m, fd, ltype, ptr) \
00365     {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
00366     fd, \
00367     pb_delta(st, has_ ## m, m), \
00368     pb_membersize(st, m), 0, ptr}
00369 
00370 /* Repeated fields have a _count field and also the maximum number of entries. */
00371 #define PB_REPEATED_STATIC(tag, st, m, fd, ltype, ptr) \
00372     {tag, PB_ATYPE_STATIC | PB_HTYPE_REPEATED | ltype, \
00373     fd, \
00374     pb_delta(st, m ## _count, m), \
00375     pb_membersize(st, m[0]), \
00376     pb_arraysize(st, m), ptr}
00377 
00378 /* Allocated fields carry the size of the actual data, not the pointer */
00379 #define PB_REQUIRED_POINTER(tag, st, m, fd, ltype, ptr) \
00380     {tag, PB_ATYPE_POINTER | PB_HTYPE_REQUIRED | ltype, \
00381     fd, 0, pb_membersize(st, m[0]), 0, ptr}
00382 
00383 /* Optional fields don't need a has_ variable, as information would be redundant */
00384 #define PB_OPTIONAL_POINTER(tag, st, m, fd, ltype, ptr) \
00385     {tag, PB_ATYPE_POINTER | PB_HTYPE_OPTIONAL | ltype, \
00386     fd, 0, pb_membersize(st, m[0]), 0, ptr}
00387 
00388 /* Repeated fields have a _count field and a pointer to array of pointers */
00389 #define PB_REPEATED_POINTER(tag, st, m, fd, ltype, ptr) \
00390     {tag, PB_ATYPE_POINTER | PB_HTYPE_REPEATED | ltype, \
00391     fd, pb_delta(st, m ## _count, m), \
00392     pb_membersize(st, m[0]), 0, ptr}
00393 
00394 /* Callbacks are much like required fields except with special datatype. */
00395 #define PB_REQUIRED_CALLBACK(tag, st, m, fd, ltype, ptr) \
00396     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REQUIRED | ltype, \
00397     fd, 0, pb_membersize(st, m), 0, ptr}
00398 
00399 #define PB_OPTIONAL_CALLBACK(tag, st, m, fd, ltype, ptr) \
00400     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
00401     fd, 0, pb_membersize(st, m), 0, ptr}
00402     
00403 #define PB_REPEATED_CALLBACK(tag, st, m, fd, ltype, ptr) \
00404     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REPEATED | ltype, \
00405     fd, 0, pb_membersize(st, m), 0, ptr}
00406 
00407 /* Optional extensions don't have the has_ field, as that would be redundant. */
00408 #define PB_OPTEXT_STATIC(tag, st, m, fd, ltype, ptr) \
00409     {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
00410     0, \
00411     0, \
00412     pb_membersize(st, m), 0, ptr}
00413 
00414 #define PB_OPTEXT_CALLBACK(tag, st, m, fd, ltype, ptr) \
00415     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
00416     0, 0, pb_membersize(st, m), 0, ptr}
00417 
00418 /* The mapping from protobuf types to LTYPEs is done using these macros. */
00419 #define PB_LTYPE_MAP_BOOL       PB_LTYPE_VARINT
00420 #define PB_LTYPE_MAP_BYTES      PB_LTYPE_BYTES
00421 #define PB_LTYPE_MAP_DOUBLE     PB_LTYPE_FIXED64
00422 #define PB_LTYPE_MAP_ENUM       PB_LTYPE_VARINT
00423 #define PB_LTYPE_MAP_FIXED32    PB_LTYPE_FIXED32
00424 #define PB_LTYPE_MAP_FIXED64    PB_LTYPE_FIXED64
00425 #define PB_LTYPE_MAP_FLOAT      PB_LTYPE_FIXED32
00426 #define PB_LTYPE_MAP_INT32      PB_LTYPE_VARINT
00427 #define PB_LTYPE_MAP_INT64      PB_LTYPE_VARINT
00428 #define PB_LTYPE_MAP_MESSAGE    PB_LTYPE_SUBMESSAGE
00429 #define PB_LTYPE_MAP_SFIXED32   PB_LTYPE_FIXED32
00430 #define PB_LTYPE_MAP_SFIXED64   PB_LTYPE_FIXED64
00431 #define PB_LTYPE_MAP_SINT32     PB_LTYPE_SVARINT
00432 #define PB_LTYPE_MAP_SINT64     PB_LTYPE_SVARINT
00433 #define PB_LTYPE_MAP_STRING     PB_LTYPE_STRING
00434 #define PB_LTYPE_MAP_UINT32     PB_LTYPE_UVARINT
00435 #define PB_LTYPE_MAP_UINT64     PB_LTYPE_UVARINT
00436 #define PB_LTYPE_MAP_EXTENSION  PB_LTYPE_EXTENSION
00437 
00438 /* This is the actual macro used in field descriptions.
00439  * It takes these arguments:
00440  * - Field tag number
00441  * - Field type:   BOOL, BYTES, DOUBLE, ENUM, FIXED32, FIXED64,
00442  *                 FLOAT, INT32, INT64, MESSAGE, SFIXED32, SFIXED64
00443  *                 SINT32, SINT64, STRING, UINT32, UINT64 or EXTENSION
00444  * - Field rules:  REQUIRED, OPTIONAL or REPEATED
00445  * - Allocation:   STATIC or CALLBACK
00446  * - Message name
00447  * - Field name
00448  * - Previous field name (or field name again for first field)
00449  * - Pointer to default value or submsg fields.
00450  */
00451 
00452 #define PB_FIELD(tag, type, rules, allocation, message, field, prevfield, ptr) \
00453     PB_ ## rules ## _ ## allocation(tag, message, field, \
00454         PB_DATAOFFSET_CHOOSE(message, field, prevfield), \
00455         PB_LTYPE_MAP_ ## type, ptr)
00456 
00457 /* This is a new version of the macro used by nanopb generator from
00458  * version 0.2.3 onwards. It avoids the use of a ternary expression in
00459  * the initialization, which confused some compilers.
00460  *
00461  * - Placement: FIRST or OTHER, depending on if this is the first field in structure.
00462  *
00463  */
00464 #define PB_FIELD2(tag, type, rules, allocation, placement, message, field, prevfield, ptr) \
00465     PB_ ## rules ## _ ## allocation(tag, message, field, \
00466         PB_DATAOFFSET_ ## placement(message, field, prevfield), \
00467         PB_LTYPE_MAP_ ## type, ptr)
00468 
00469 
00470 /* These macros are used for giving out error messages.
00471  * They are mostly a debugging aid; the main error information
00472  * is the true/false return value from functions.
00473  * Some code space can be saved by disabling the error
00474  * messages if not used.
00475  */
00476 #ifdef PB_NO_ERRMSG
00477 #define PB_RETURN_ERROR(stream,msg) return false
00478 #define PB_GET_ERROR(stream) "(errmsg disabled)"
00479 #else
00480 #define PB_RETURN_ERROR(stream,msg) \
00481     do {\
00482         if ((stream)->errmsg == NULL) \
00483             (stream)->errmsg = (msg); \
00484         return false; \
00485     } while(0)
00486 #define PB_GET_ERROR(stream) ((stream)->errmsg ? (stream)->errmsg : "(none)")
00487 #endif
00488 
00489 #endif
00490