Diff: pb.h

Revision:

2:d2c61a9be078

Parent:

0:c7beea49fc91

--- a/pb.h	Fri Mar 01 12:41:26 2013 +0000
+++ b/pb.h	Fri Aug 16 16:41:33 2019 +0000
@@ -1,40 +1,132 @@
-#ifndef _PB_H_
-#define _PB_H_
-
-/* pb.h: Common parts for nanopb library.
- * Most of these are quite low-level stuff. For the high-level interface,
- * see pb_encode.h or pb_decode.h
+/* Common parts of the nanopb library. Most of these are quite low-level
+ * stuff. For the high-level interface, see pb_encode.h and pb_decode.h.
  */
 
-#define NANOPB_VERSION nanopb-0.1.9
+#ifndef PB_H_INCLUDED
+#define PB_H_INCLUDED
+
+/*****************************************************************
+ * Nanopb compilation time options. You can change these here by *
+ * uncommenting the lines, or on the compiler command line.      *
+ *****************************************************************/
+
+/* Enable support for dynamically allocated fields */
+/* #define PB_ENABLE_MALLOC 1 */
+
+/* Define this if your CPU / compiler combination does not support
+ * unaligned memory access to packed structures. */
+/* #define PB_NO_PACKED_STRUCTS 1 */
+
+/* Increase the number of required fields that are tracked.
+ * A compiler warning will tell if you need this. */
+/* #define PB_MAX_REQUIRED_FIELDS 256 */
+
+/* Add support for tag numbers > 255 and fields larger than 255 bytes. */
+/* #define PB_FIELD_16BIT 1 */
+
+/* Add support for tag numbers > 65536 and fields larger than 65536 bytes. */
+/* #define PB_FIELD_32BIT 1 */
+
+/* Disable support for error messages in order to save some code space. */
+/* #define PB_NO_ERRMSG 1 */
 
+/* Disable support for custom streams (support only memory buffers). */
+/* #define PB_BUFFER_ONLY 1 */
+
+/* Switch back to the old-style callback function signature.
+ * This was the default until nanopb-0.2.1. */
+/* #define PB_OLD_CALLBACK_STYLE */
+
+
+/******************************************************************
+ * You usually don't need to change anything below this line.     *
+ * Feel free to look around and use the defined macros, though.   *
+ ******************************************************************/
+
+
+/* Version of the nanopb library. Just in case you want to check it in
+ * your own program. */
+#define NANOPB_VERSION nanopb-0.3.9.3
+
+/* Include all the system headers needed by nanopb. You will need the
+ * definitions of the following:
+ * - strlen, memcpy, memset functions
+ * - [u]int_least8_t, uint_fast8_t, [u]int_least16_t, [u]int32_t, [u]int64_t
+ * - size_t
+ * - bool
+ *
+ * If you don't have the standard header files, you can instead provide
+ * a custom header that defines or includes all this. In that case,
+ * define PB_SYSTEM_HEADER to the path of this file.
+ */
+#ifdef PB_SYSTEM_HEADER
+#include PB_SYSTEM_HEADER
+#else
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <string.h>
 
-#ifdef __GNUC__
-/* This just reduces memory requirements, but is not required. */
-#define pb_packed __attribute__((packed))
-#else
-#define pb_packed
+#ifdef PB_ENABLE_MALLOC
+#include <stdlib.h>
+#endif
 #endif
 
-/* Handly macro for suppressing unreferenced-parameter compiler warnings.    */
-#ifndef UNUSED
-#define UNUSED(x) (void)(x)
+/* Macro for defining packed structures (compiler dependent).
+ * This just reduces memory requirements, but is not required.
+ */
+#if defined(PB_NO_PACKED_STRUCTS)
+    /* Disable struct packing */
+#   define PB_PACKED_STRUCT_START
+#   define PB_PACKED_STRUCT_END
+#   define pb_packed
+#elif defined(__GNUC__) || defined(__clang__)
+    /* For GCC and clang */
+#   define PB_PACKED_STRUCT_START
+#   define PB_PACKED_STRUCT_END
+#   define pb_packed __attribute__((packed))
+#elif defined(__ICCARM__) || defined(__CC_ARM)
+    /* For IAR ARM and Keil MDK-ARM compilers */
+#   define PB_PACKED_STRUCT_START _Pragma("pack(push, 1)")
+#   define PB_PACKED_STRUCT_END _Pragma("pack(pop)")
+#   define pb_packed
+#elif defined(_MSC_VER) && (_MSC_VER >= 1500)
+    /* For Microsoft Visual C++ */
+#   define PB_PACKED_STRUCT_START __pragma(pack(push, 1))
+#   define PB_PACKED_STRUCT_END __pragma(pack(pop))
+#   define pb_packed
+#else
+    /* Unknown compiler */
+#   define PB_PACKED_STRUCT_START
+#   define PB_PACKED_STRUCT_END
+#   define pb_packed
+#endif
+
+/* Handly macro for suppressing unreferenced-parameter compiler warnings. */
+#ifndef PB_UNUSED
+#define PB_UNUSED(x) (void)(x)
 #endif
 
 /* Compile-time assertion, used for checking compatible compilation options.
- * If this fails on your compiler for some reason, use #define STATIC_ASSERT
- * to disable it. */
-#ifndef STATIC_ASSERT
-#define STATIC_ASSERT(COND,MSG) typedef char STATIC_ASSERT_MSG(MSG, __LINE__, __COUNTER__)[(COND)?1:-1];
-#define STATIC_ASSERT_MSG(MSG, LINE, COUNTER) STATIC_ASSERT_MSG_(MSG, LINE, COUNTER)
-#define STATIC_ASSERT_MSG_(MSG, LINE, COUNTER) static_assertion_##MSG##LINE##COUNTER
+ * If this does not work properly on your compiler, use
+ * #define PB_NO_STATIC_ASSERT to disable it.
+ *
+ * But before doing that, check carefully the error message / place where it
+ * comes from to see if the error has a real cause. Unfortunately the error
+ * message is not always very clear to read, but you can see the reason better
+ * in the place where the PB_STATIC_ASSERT macro was called.
+ */
+#ifndef PB_NO_STATIC_ASSERT
+#ifndef PB_STATIC_ASSERT
+#define PB_STATIC_ASSERT(COND,MSG) typedef char PB_STATIC_ASSERT_MSG(MSG, __LINE__, __COUNTER__)[(COND)?1:-1];
+#define PB_STATIC_ASSERT_MSG(MSG, LINE, COUNTER) PB_STATIC_ASSERT_MSG_(MSG, LINE, COUNTER)
+#define PB_STATIC_ASSERT_MSG_(MSG, LINE, COUNTER) pb_static_assertion_##MSG##LINE##COUNTER
+#endif
+#else
+#define PB_STATIC_ASSERT(COND,MSG)
 #endif
 
-/* Number of required fields to keep track of
- * (change here or on compiler command line). */
+/* Number of required fields to keep track of. */
 #ifndef PB_MAX_REQUIRED_FIELDS
 #define PB_MAX_REQUIRED_FIELDS 64
 #endif
@@ -46,70 +138,88 @@
 /* List of possible field types. These are used in the autogenerated code.
  * Least-significant 4 bits tell the scalar type
  * Most-significant 4 bits specify repeated/required/packed etc.
- * 
- * INT32 and UINT32 are treated the same, as are (U)INT64 and (S)FIXED*
- * These types are simply casted to correct field type when they are
- * assigned to the memory pointer.
- * SINT* is different, though, because it is zig-zag coded.
  */
 
-typedef enum {
-    /************************
-     * Field contents types *
-     ************************/
-    
-    /* Numeric types */
-    PB_LTYPE_VARINT = 0x00, /* int32, uint32, int64, uint64, bool, enum */
-    PB_LTYPE_SVARINT = 0x01, /* sint32, sint64 */
-    PB_LTYPE_FIXED32 = 0x02, /* fixed32, sfixed32, float */
-    PB_LTYPE_FIXED64 = 0x03, /* fixed64, sfixed64, double */
-    
-    /* Marker for last packable field type. */
-    PB_LTYPE_LAST_PACKABLE = 0x03,
-    
-    /* Byte array with pre-allocated buffer.
-     * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
-    PB_LTYPE_BYTES = 0x04,
-    
-    /* String with pre-allocated buffer.
-     * data_size is the maximum length. */
-    PB_LTYPE_STRING = 0x05,
-    
-    /* Submessage
-     * submsg_fields is pointer to field descriptions */
-    PB_LTYPE_SUBMESSAGE = 0x06,
-    
-    /* Number of declared LTYPES */
-    PB_LTYPES_COUNT = 7,
-    PB_LTYPE_MASK = 0x0F,
-    
-    /******************
-     * Modifier flags *
-     ******************/
-    
-    /* Just the basic, write data at data_offset */
-    PB_HTYPE_REQUIRED = 0x00,
-    
-    /* Write true at size_offset */
-    PB_HTYPE_OPTIONAL = 0x10,
-    
-    /* Read to pre-allocated array
-     * Maximum number of entries is array_size,
-     * actual number is stored at size_offset */
-    PB_HTYPE_ARRAY = 0x20,
-    
-    /* Works for all required/optional/repeated fields.
-     * data_offset points to pb_callback_t structure.
-     * LTYPE should be valid or 0 (it is ignored, but
-     * sometimes used to speculatively index an array). */
-    PB_HTYPE_CALLBACK = 0x30,
-    
-    PB_HTYPE_MASK = 0xF0
-} pb_packed pb_type_t;
+typedef uint_least8_t pb_type_t;
+
+/**** Field data types ****/
+
+/* Numeric types */
+#define PB_LTYPE_VARINT  0x00 /* int32, int64, enum, bool */
+#define PB_LTYPE_UVARINT 0x01 /* uint32, uint64 */
+#define PB_LTYPE_SVARINT 0x02 /* sint32, sint64 */
+#define PB_LTYPE_FIXED32 0x03 /* fixed32, sfixed32, float */
+#define PB_LTYPE_FIXED64 0x04 /* fixed64, sfixed64, double */
+
+/* Marker for last packable field type. */
+#define PB_LTYPE_LAST_PACKABLE 0x04
+
+/* Byte array with pre-allocated buffer.
+ * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
+#define PB_LTYPE_BYTES 0x05
+
+/* String with pre-allocated buffer.
+ * data_size is the maximum length. */
+#define PB_LTYPE_STRING 0x06
+
+/* Submessage
+ * submsg_fields is pointer to field descriptions */
+#define PB_LTYPE_SUBMESSAGE 0x07
 
+/* Extension pseudo-field
+ * The field contains a pointer to pb_extension_t */
+#define PB_LTYPE_EXTENSION 0x08
+
+/* Byte array with inline, pre-allocated byffer.
+ * data_size is the length of the inline, allocated buffer.
+ * This differs from PB_LTYPE_BYTES by defining the element as
+ * pb_byte_t[data_size] rather than pb_bytes_array_t. */
+#define PB_LTYPE_FIXED_LENGTH_BYTES 0x09
+
+/* Number of declared LTYPES */
+#define PB_LTYPES_COUNT 0x0A
+#define PB_LTYPE_MASK 0x0F
+
+/**** Field repetition rules ****/
+
+#define PB_HTYPE_REQUIRED 0x00
+#define PB_HTYPE_OPTIONAL 0x10
+#define PB_HTYPE_REPEATED 0x20
+#define PB_HTYPE_ONEOF    0x30
+#define PB_HTYPE_MASK     0x30
+
+/**** Field allocation types ****/
+ 
+#define PB_ATYPE_STATIC   0x00
+#define PB_ATYPE_POINTER  0x80
+#define PB_ATYPE_CALLBACK 0x40
+#define PB_ATYPE_MASK     0xC0
+
+#define PB_ATYPE(x) ((x) & PB_ATYPE_MASK)
 #define PB_HTYPE(x) ((x) & PB_HTYPE_MASK)
 #define PB_LTYPE(x) ((x) & PB_LTYPE_MASK)
 
+/* Data type used for storing sizes of struct fields
+ * and array counts.
+ */
+#if defined(PB_FIELD_32BIT)
+    typedef uint32_t pb_size_t;
+    typedef int32_t pb_ssize_t;
+#elif defined(PB_FIELD_16BIT)
+    typedef uint_least16_t pb_size_t;
+    typedef int_least16_t pb_ssize_t;
+#else
+    typedef uint_least8_t pb_size_t;
+    typedef int_least8_t pb_ssize_t;
+#endif
+#define PB_SIZE_MAX ((pb_size_t)-1)
+
+/* Data type for storing encoded data and other byte streams.
+ * This typedef exists to support platforms where uint8_t does not exist.
+ * You can regard it as equivalent on uint8_t on other platforms.
+ */
+typedef uint_least8_t pb_byte_t;
+
 /* This structure is used in auto-generated constants
  * to specify struct fields.
  * You can change field sizes if you need structures
@@ -118,48 +228,46 @@
  * structures. Fix that by defining PB_FIELD_16BIT or
  * PB_FIELD_32BIT.
  */
-typedef struct _pb_field_t pb_field_t;
-struct _pb_field_t {
-
-#if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
-    uint8_t tag;
-    pb_type_t type;
-    uint8_t data_offset; /* Offset of field data, relative to previous field. */
-    int8_t size_offset; /* Offset of array size or has-boolean, relative to data */
-    uint8_t data_size; /* Data size in bytes for a single item */
-    uint8_t array_size; /* Maximum number of entries in array */
-#elif defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
-    uint16_t tag;
+PB_PACKED_STRUCT_START
+typedef struct pb_field_s pb_field_t;
+struct pb_field_s {
+    pb_size_t tag;
     pb_type_t type;
-    uint8_t data_offset;
-    int8_t size_offset;
-    uint16_t data_size;
-    uint16_t array_size;
-#else
-    uint32_t tag;
-    pb_type_t type;
-    uint8_t data_offset;
-    int8_t size_offset;
-    uint32_t data_size;
-    uint32_t array_size;
-#endif
+    pb_size_t data_offset; /* Offset of field data, relative to previous field. */
+    pb_ssize_t size_offset; /* Offset of array size or has-boolean, relative to data */
+    pb_size_t data_size; /* Data size in bytes for a single item */
+    pb_size_t array_size; /* Maximum number of entries in array */
     
     /* Field definitions for submessage
      * OR default value for all other non-array, non-callback types
      * If null, then field will zeroed. */
     const void *ptr;
 } pb_packed;
+PB_PACKED_STRUCT_END
+
+/* Make sure that the standard integer types are of the expected sizes.
+ * Otherwise fixed32/fixed64 fields can break.
+ *
+ * If you get errors here, it probably means that your stdint.h is not
+ * correct for your platform.
+ */
+#ifndef PB_WITHOUT_64BIT
+PB_STATIC_ASSERT(sizeof(int64_t) == 2 * sizeof(int32_t), INT64_T_WRONG_SIZE)
+PB_STATIC_ASSERT(sizeof(uint64_t) == 2 * sizeof(uint32_t), UINT64_T_WRONG_SIZE)
+#endif
 
 /* This structure is used for 'bytes' arrays.
  * It has the number of bytes in the beginning, and after that an array.
  * Note that actual structs used will have a different length of bytes array.
  */
-struct _pb_bytes_array_t {
-    size_t size;
-    uint8_t bytes[1];
+#define PB_BYTES_ARRAY_T(n) struct { pb_size_t size; pb_byte_t bytes[n]; }
+#define PB_BYTES_ARRAY_T_ALLOCSIZE(n) ((size_t)n + offsetof(pb_bytes_array_t, bytes))
+
+struct pb_bytes_array_s {
+    pb_size_t size;
+    pb_byte_t bytes[1];
 };
-
-typedef struct _pb_bytes_array_t pb_bytes_array_t;
+typedef struct pb_bytes_array_s pb_bytes_array_t;
 
 /* This structure is used for giving the callback function.
  * It is stored in the message structure and filled in by the method that
@@ -179,14 +287,23 @@
  *
  * The callback can be null if you want to skip a field.
  */
-typedef struct _pb_istream_t pb_istream_t;
-typedef struct _pb_ostream_t pb_ostream_t;
-typedef struct _pb_callback_t pb_callback_t;
-struct _pb_callback_t {
+typedef struct pb_istream_s pb_istream_t;
+typedef struct pb_ostream_s pb_ostream_t;
+typedef struct pb_callback_s pb_callback_t;
+struct pb_callback_s {
+#ifdef PB_OLD_CALLBACK_STYLE
+    /* Deprecated since nanopb-0.2.1 */
     union {
         bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
         bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
     } funcs;
+#else
+    /* New function signature, which allows modifying arg contents in callback. */
+    union {
+        bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
+        bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
+    } funcs;
+#endif    
     
     /* Free arg for use by callback */
     void *arg;
@@ -200,30 +317,277 @@
     PB_WT_32BIT  = 5
 } pb_wire_type_t;
 
+/* Structure for defining the handling of unknown/extension fields.
+ * Usually the pb_extension_type_t structure is automatically generated,
+ * while the pb_extension_t structure is created by the user. However,
+ * if you want to catch all unknown fields, you can also create a custom
+ * pb_extension_type_t with your own callback.
+ */
+typedef struct pb_extension_type_s pb_extension_type_t;
+typedef struct pb_extension_s pb_extension_t;
+struct pb_extension_type_s {
+    /* Called for each unknown field in the message.
+     * If you handle the field, read off all of its data and return true.
+     * If you do not handle the field, do not read anything and return true.
+     * If you run into an error, return false.
+     * Set to NULL for default handler.
+     */
+    bool (*decode)(pb_istream_t *stream, pb_extension_t *extension,
+                   uint32_t tag, pb_wire_type_t wire_type);
+    
+    /* Called once after all regular fields have been encoded.
+     * If you have something to write, do so and return true.
+     * If you do not have anything to write, just return true.
+     * If you run into an error, return false.
+     * Set to NULL for default handler.
+     */
+    bool (*encode)(pb_ostream_t *stream, const pb_extension_t *extension);
+    
+    /* Free field for use by the callback. */
+    const void *arg;
+};
+
+struct pb_extension_s {
+    /* Type describing the extension field. Usually you'll initialize
+     * this to a pointer to the automatically generated structure. */
+    const pb_extension_type_t *type;
+    
+    /* Destination for the decoded data. This must match the datatype
+     * of the extension field. */
+    void *dest;
+    
+    /* Pointer to the next extension handler, or NULL.
+     * If this extension does not match a field, the next handler is
+     * automatically called. */
+    pb_extension_t *next;
+
+    /* The decoder sets this to true if the extension was found.
+     * Ignored for encoding. */
+    bool found;
+};
+
+/* Memory allocation functions to use. You can define pb_realloc and
+ * pb_free to custom functions if you want. */
+#ifdef PB_ENABLE_MALLOC
+#   ifndef pb_realloc
+#       define pb_realloc(ptr, size) realloc(ptr, size)
+#   endif
+#   ifndef pb_free
+#       define pb_free(ptr) free(ptr)
+#   endif
+#endif
+
+/* This is used to inform about need to regenerate .pb.h/.pb.c files. */
+#define PB_PROTO_HEADER_VERSION 30
+
 /* These macros are used to declare pb_field_t's in the constant array. */
+/* Size of a structure member, in bytes. */
 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
+/* Number of entries in an array. */
 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
+/* Delta from start of one member to the start of another member. */
 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
-#define pb_delta_end(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
+/* Marks the end of the field list */
 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}
 
+/* Macros for filling in the data_offset field */
+/* data_offset for first field in a message */
+#define PB_DATAOFFSET_FIRST(st, m1, m2) (offsetof(st, m1))
+/* data_offset for subsequent fields */
+#define PB_DATAOFFSET_OTHER(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
+/* data offset for subsequent fields inside an union (oneof) */
+#define PB_DATAOFFSET_UNION(st, m1, m2) (PB_SIZE_MAX)
+/* Choose first/other based on m1 == m2 (deprecated, remains for backwards compatibility) */
+#define PB_DATAOFFSET_CHOOSE(st, m1, m2) (int)(offsetof(st, m1) == offsetof(st, m2) \
+                                  ? PB_DATAOFFSET_FIRST(st, m1, m2) \
+                                  : PB_DATAOFFSET_OTHER(st, m1, m2))
+
+/* Required fields are the simplest. They just have delta (padding) from
+ * previous field end, and the size of the field. Pointer is used for
+ * submessages and default values.
+ */
+#define PB_REQUIRED_STATIC(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_REQUIRED | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+
+/* Optional fields add the delta to the has_ variable. */
+#define PB_OPTIONAL_STATIC(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
+    fd, \
+    pb_delta(st, has_ ## m, m), \
+    pb_membersize(st, m), 0, ptr}
+
+#define PB_SINGULAR_STATIC(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+
+/* Repeated fields have a _count field and also the maximum number of entries. */
+#define PB_REPEATED_STATIC(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_REPEATED | ltype, \
+    fd, \
+    pb_delta(st, m ## _count, m), \
+    pb_membersize(st, m[0]), \
+    pb_arraysize(st, m), ptr}
+
+/* Allocated fields carry the size of the actual data, not the pointer */
+#define PB_REQUIRED_POINTER(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_REQUIRED | ltype, \
+    fd, 0, pb_membersize(st, m[0]), 0, ptr}
+
+/* Optional fields don't need a has_ variable, as information would be redundant */
+#define PB_OPTIONAL_POINTER(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_OPTIONAL | ltype, \
+    fd, 0, pb_membersize(st, m[0]), 0, ptr}
+
+/* Same as optional fields*/
+#define PB_SINGULAR_POINTER(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_OPTIONAL | ltype, \
+    fd, 0, pb_membersize(st, m[0]), 0, ptr}
+
+/* Repeated fields have a _count field and a pointer to array of pointers */
+#define PB_REPEATED_POINTER(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_REPEATED | ltype, \
+    fd, pb_delta(st, m ## _count, m), \
+    pb_membersize(st, m[0]), 0, ptr}
+
+/* Callbacks are much like required fields except with special datatype. */
+#define PB_REQUIRED_CALLBACK(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REQUIRED | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+
+#define PB_OPTIONAL_CALLBACK(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+
+#define PB_SINGULAR_CALLBACK(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+    
+#define PB_REPEATED_CALLBACK(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REPEATED | ltype, \
+    fd, 0, pb_membersize(st, m), 0, ptr}
+
+/* Optional extensions don't have the has_ field, as that would be redundant.
+ * Furthermore, the combination of OPTIONAL without has_ field is used
+ * for indicating proto3 style fields. Extensions exist in proto2 mode only,
+ * so they should be encoded according to proto2 rules. To avoid the conflict,
+ * extensions are marked as REQUIRED instead.
+ */
+#define PB_OPTEXT_STATIC(tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_REQUIRED | ltype, \
+    0, \
+    0, \
+    pb_membersize(st, m), 0, ptr}
+
+#define PB_OPTEXT_POINTER(tag, st, m, fd, ltype, ptr) \
+    PB_OPTIONAL_POINTER(tag, st, m, fd, ltype, ptr)
+
+#define PB_OPTEXT_CALLBACK(tag, st, m, fd, ltype, ptr) \
+    PB_OPTIONAL_CALLBACK(tag, st, m, fd, ltype, ptr)
+
+/* The mapping from protobuf types to LTYPEs is done using these macros. */
+#define PB_LTYPE_MAP_BOOL               PB_LTYPE_VARINT
+#define PB_LTYPE_MAP_BYTES              PB_LTYPE_BYTES
+#define PB_LTYPE_MAP_DOUBLE             PB_LTYPE_FIXED64
+#define PB_LTYPE_MAP_ENUM               PB_LTYPE_VARINT
+#define PB_LTYPE_MAP_UENUM              PB_LTYPE_UVARINT
+#define PB_LTYPE_MAP_FIXED32            PB_LTYPE_FIXED32
+#define PB_LTYPE_MAP_FIXED64            PB_LTYPE_FIXED64
+#define PB_LTYPE_MAP_FLOAT              PB_LTYPE_FIXED32
+#define PB_LTYPE_MAP_INT32              PB_LTYPE_VARINT
+#define PB_LTYPE_MAP_INT64              PB_LTYPE_VARINT
+#define PB_LTYPE_MAP_MESSAGE            PB_LTYPE_SUBMESSAGE
+#define PB_LTYPE_MAP_SFIXED32           PB_LTYPE_FIXED32
+#define PB_LTYPE_MAP_SFIXED64           PB_LTYPE_FIXED64
+#define PB_LTYPE_MAP_SINT32             PB_LTYPE_SVARINT
+#define PB_LTYPE_MAP_SINT64             PB_LTYPE_SVARINT
+#define PB_LTYPE_MAP_STRING             PB_LTYPE_STRING
+#define PB_LTYPE_MAP_UINT32             PB_LTYPE_UVARINT
+#define PB_LTYPE_MAP_UINT64             PB_LTYPE_UVARINT
+#define PB_LTYPE_MAP_EXTENSION          PB_LTYPE_EXTENSION
+#define PB_LTYPE_MAP_FIXED_LENGTH_BYTES PB_LTYPE_FIXED_LENGTH_BYTES
+
+/* This is the actual macro used in field descriptions.
+ * It takes these arguments:
+ * - Field tag number
+ * - Field type:   BOOL, BYTES, DOUBLE, ENUM, UENUM, FIXED32, FIXED64,
+ *                 FLOAT, INT32, INT64, MESSAGE, SFIXED32, SFIXED64
+ *                 SINT32, SINT64, STRING, UINT32, UINT64 or EXTENSION
+ * - Field rules:  REQUIRED, OPTIONAL or REPEATED
+ * - Allocation:   STATIC, CALLBACK or POINTER
+ * - Placement: FIRST or OTHER, depending on if this is the first field in structure.
+ * - Message name
+ * - Field name
+ * - Previous field name (or field name again for first field)
+ * - Pointer to default value or submsg fields.
+ */
+
+#define PB_FIELD(tag, type, rules, allocation, placement, message, field, prevfield, ptr) \
+        PB_ ## rules ## _ ## allocation(tag, message, field, \
+        PB_DATAOFFSET_ ## placement(message, field, prevfield), \
+        PB_LTYPE_MAP_ ## type, ptr)
+
+/* Field description for repeated static fixed count fields.*/
+#define PB_REPEATED_FIXED_COUNT(tag, type, placement, message, field, prevfield, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_REPEATED | PB_LTYPE_MAP_ ## type, \
+    PB_DATAOFFSET_ ## placement(message, field, prevfield), \
+    0, \
+    pb_membersize(message, field[0]), \
+    pb_arraysize(message, field), ptr}
+
+/* Field description for oneof fields. This requires taking into account the
+ * union name also, that's why a separate set of macros is needed.
+ */
+#define PB_ONEOF_STATIC(u, tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_ONEOF | ltype, \
+    fd, pb_delta(st, which_ ## u, u.m), \
+    pb_membersize(st, u.m), 0, ptr}
+
+#define PB_ONEOF_POINTER(u, tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_ONEOF | ltype, \
+    fd, pb_delta(st, which_ ## u, u.m), \
+    pb_membersize(st, u.m[0]), 0, ptr}
+
+#define PB_ONEOF_FIELD(union_name, tag, type, rules, allocation, placement, message, field, prevfield, ptr) \
+        PB_ONEOF_ ## allocation(union_name, tag, message, field, \
+        PB_DATAOFFSET_ ## placement(message, union_name.field, prevfield), \
+        PB_LTYPE_MAP_ ## type, ptr)
+
+#define PB_ANONYMOUS_ONEOF_STATIC(u, tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_STATIC | PB_HTYPE_ONEOF | ltype, \
+    fd, pb_delta(st, which_ ## u, m), \
+    pb_membersize(st, m), 0, ptr}
+
+#define PB_ANONYMOUS_ONEOF_POINTER(u, tag, st, m, fd, ltype, ptr) \
+    {tag, PB_ATYPE_POINTER | PB_HTYPE_ONEOF | ltype, \
+    fd, pb_delta(st, which_ ## u, m), \
+    pb_membersize(st, m[0]), 0, ptr}
+
+#define PB_ANONYMOUS_ONEOF_FIELD(union_name, tag, type, rules, allocation, placement, message, field, prevfield, ptr) \
+        PB_ANONYMOUS_ONEOF_ ## allocation(union_name, tag, message, field, \
+        PB_DATAOFFSET_ ## placement(message, field, prevfield), \
+        PB_LTYPE_MAP_ ## type, ptr)
+
 /* These macros are used for giving out error messages.
  * They are mostly a debugging aid; the main error information
  * is the true/false return value from functions.
  * Some code space can be saved by disabling the error
  * messages if not used.
+ *
+ * PB_SET_ERROR() sets the error message if none has been set yet.
+ *                msg must be a constant string literal.
+ * PB_GET_ERROR() always returns a pointer to a string.
+ * PB_RETURN_ERROR() sets the error and returns false from current
+ *                   function.
  */
 #ifdef PB_NO_ERRMSG
-#define PB_RETURN_ERROR(stream,msg) return false
+#define PB_SET_ERROR(stream, msg) PB_UNUSED(stream)
 #define PB_GET_ERROR(stream) "(errmsg disabled)"
 #else
-#define PB_RETURN_ERROR(stream,msg) \
-    do {\
-        if ((stream)->errmsg == NULL) \
-            (stream)->errmsg = (msg); \
-        return false; \
-    } while(0)
+#define PB_SET_ERROR(stream, msg) (stream->errmsg = (stream)->errmsg ? (stream)->errmsg : (msg))
 #define PB_GET_ERROR(stream) ((stream)->errmsg ? (stream)->errmsg : "(none)")
 #endif
 
-#endif
+#define PB_RETURN_ERROR(stream, msg) return PB_SET_ERROR(stream, msg), false
+
+#endif
\ No newline at end of file