Perform field initialization to defaults only when the field is skipped.

Avoids unnecessary initialization & unnecessary scan of
the pb_field_t array.

Runtime on Cortex-M3 -5%, code size +2%.

Could need some more testing with random field orders.
Have to write a tool to randomize fields in a message.

docs/concepts.rst

@@ -181,7 +181,9 @@ Field callbacks
 ===============
 When a field has dynamic length, nanopb cannot statically allocate storage for it. Instead, it allows you to handle the field in whatever way you want, using a callback function.
 
-The `pb_callback_t`_ structure contains a function pointer and a *void* pointer you can use for passing data to the callback. If the function pointer is NULL, the field will be skipped. The actual behavior of the callback function is different in encoding and decoding modes.
+The `pb_callback_t`_ structure contains a function pointer and a *void* pointer called *arg* you can use for passing data to the callback. If the function pointer is NULL, the field will be skipped. A pointer to the *arg* is passed to the function, so that it can modify it and retrieve the value.
+
+The actual behavior of the callback function is different in encoding and decoding modes. In encoding mode, the callback is called once and should write out everything, including field tags. In decoding mode, the callback is called repeatedly for every data item.
 
 .. _`pb_callback_t`: reference.html#pb-callback-t
 
@@ -189,7 +191,7 @@ Encoding callbacks
 ------------------
 ::
 
-    bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
+    bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
 
 When encoding, the callback should write out complete fields, including the wire type and field number tag. It can write as many or as few fields as it likes. For example, if you want to write out an array as *repeated* field, you should do it all in a single call.
 
@@ -203,7 +205,7 @@ If the callback is used in a submessage, it will be called multiple times during
 
 This callback writes out a dynamically sized string::
 
-    bool write_string(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+    bool write_string(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
     {
         char *str = get_string_from_somewhere();
         if (!pb_encode_tag_for_field(stream, field))
@@ -216,7 +218,7 @@ Decoding callbacks
 ------------------
 ::
 
-    bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
+    bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
 
 When decoding, the callback receives a length-limited substring that reads the contents of a single field. The field tag has already been read. For *string* and *bytes*, the length value has already been parsed, and is available at *stream->bytes_left*.
 
@@ -226,7 +228,7 @@ The callback will be called multiple times for repeated fields. For packed field
 
 This callback reads multiple integers and prints them::
 
-    bool read_ints(pb_istream_t *stream, const pb_field_t *field, void *arg)
+    bool read_ints(pb_istream_t *stream, const pb_field_t *field, void **arg)
     {
         while (stream->bytes_left)
         {

docs/reference.rst

@@ -24,6 +24,8 @@ PB_NO_ERRMSG                   Disables the support for error messages; only err
                                Decreases the code size by a few hundred bytes.
 PB_BUFFER_ONLY                 Disables the support for custom streams. Only supports encoding to memory buffers.
                                Speeds up execution and decreases code size slightly.
+PB_OLD_CALLBACK_STYLE          Use the old function signature (void\* instead of void\*\*) for callback fields. This was the
+                               default until nanopb-0.2.1.
 ============================  ================================================================================================
 
 The PB_MAX_REQUIRED_FIELDS, PB_FIELD_16BIT and PB_FIELD_32BIT settings allow raising some datatype limits to suit larger messages.
@@ -122,14 +124,16 @@ Part of a message structure, for fields with type PB_HTYPE_CALLBACK::
     typedef struct _pb_callback_t pb_callback_t;
     struct _pb_callback_t {
         union {
-            bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
+            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);
+            bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
         } funcs;
         
         void *arg;
     };
 
-The *arg* is passed to the callback when calling. It can be used to store any information that the callback might need.
+A pointer to the *arg* is passed to the callback when calling. It can be used to store any information that the callback might need.
+
+Previously the function received just the value of *arg* instead of a pointer to it. This old behaviour can be enabled by defining *PB_OLD_CALLBACK_STYLE*.
 
 When calling `pb_encode`_, *funcs.encode* is used, and similarly when calling `pb_decode`_, *funcs.decode* is used. The function pointers are stored in the same memory location but are of incompatible types. You can set the function pointer to NULL to skip the field.
 

example/client.c

@@ -23,7 +23,7 @@
 #include "fileproto.pb.h"
 #include "common.h"
 
-bool printfile_callback(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool printfile_callback(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     FileInfo fileinfo;
     

example/server.c

@@ -23,9 +23,9 @@
 #include "fileproto.pb.h"
 #include "common.h"
 
-bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
-    DIR *dir = (DIR*) arg;
+    DIR *dir = (DIR*) *arg;
     struct dirent *file;
     FileInfo fileinfo;
     

generator/nanopb.proto

@@ -16,6 +16,9 @@ enum FieldType {
     FT_IGNORE = 3; // Ignore the field completely.
 }
 
+// This is the inner options message, which basically defines options for
+// a field. When it is used in message or file scope, it applies to all
+// fields.
 message NanoPBOptions {
   // Allocated size for 'bytes' and 'string' fields.
   optional int32 max_size = 1;
@@ -33,6 +36,9 @@ message NanoPBOptions {
   optional bool packed_struct = 5 [default = false];
 }
 
+// Extensions to protoc 'Descriptor' type in order to define options
+// inside a .proto file.
+//
 // Protocol Buffers extension number registry
 // --------------------------------
 // Project:  Nanopb

generator/nanopb_generator.py

@@ -1,8 +1,9 @@
 '''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
-nanopb_version = "nanopb-0.2.0"
+nanopb_version = "nanopb-0.2.1-dev"
 
 try:
     import google.protobuf.descriptor_pb2 as descriptor
+    import google.protobuf.text_format as text_format
 except:
     print
     print "*************************************************************"
@@ -54,9 +55,7 @@ datatypes = {
 }
 
 class Names:
-    '''Keeps a set of nested names and formats them to C identifier.
+    '''Keeps a set of nested names and formats them to C identifier.'''
-    You can subclass this with your own implementation.
-    '''
     def __init__(self, parts = ()):
         if isinstance(parts, Names):
             parts = parts.parts
@@ -187,7 +186,7 @@ class Field:
         return cmp(self.tag, other.tag)
     
     def __str__(self):
-        if self.rules == 'OPTIONAL':
+        if self.rules == 'OPTIONAL' and self.allocation == 'STATIC':
             result = '    bool has_' + self.name + ';\n'
         elif self.rules == 'REPEATED' and self.allocation == 'STATIC':
             result = '    size_t ' + self.name + '_count;\n'
@@ -286,7 +285,7 @@ class Message:
         self.fields = []
         
         for f in desc.field:
-            field_options = get_nanopb_suboptions(f, message_options)
+            field_options = get_nanopb_suboptions(f, message_options, self.name + f.name)
             if field_options.type != nanopb_pb2.FT_IGNORE:
                 self.fields.append(Field(self.name, f, field_options))
         
@@ -300,6 +299,12 @@ class Message:
     
     def __str__(self):
         result = 'typedef struct _%s {\n' % self.name
+
+        if not self.ordered_fields:
+            # Empty structs are not allowed in C standard.
+            # Therefore add a dummy field if an empty message occurs.
+            result += '    uint8_t dummy_field;'
+
         result += '\n'.join([str(f) for f in self.ordered_fields])
         result += '\n}'
         
@@ -307,6 +312,11 @@ class Message:
             result += ' pb_packed'
         
         result += ' %s;' % self.name
+        
+        if self.packed:
+            result = 'PB_PACKED_STRUCT_START\n' + result
+            result += '\nPB_PACKED_STRUCT_END'
+        
         return result
     
     def types(self):
@@ -377,14 +387,14 @@ def parse_file(fdesc, file_options):
         base_name = Names()
     
     for enum in fdesc.enum_type:
-        enum_options = get_nanopb_suboptions(enum, file_options)
+        enum_options = get_nanopb_suboptions(enum, file_options, base_name + enum.name)
         enums.append(Enum(base_name, enum, enum_options))
     
     for names, message in iterate_messages(fdesc, base_name):
-        message_options = get_nanopb_suboptions(message, file_options)
+        message_options = get_nanopb_suboptions(message, file_options, names)
         messages.append(Message(names, message, message_options))
         for enum in message.enum_type:
-            enum_options = get_nanopb_suboptions(enum, message_options)
+            enum_options = get_nanopb_suboptions(enum, message_options, names + enum.name)
             enums.append(Enum(names, enum, enum_options))
     
     # Fix field default values where enum short names are used.
@@ -450,11 +460,17 @@ def generate_header(dependencies, headername, enums, messages, options):
     symbol = make_identifier(headername)
     yield '#ifndef _PB_%s_\n' % symbol
     yield '#define _PB_%s_\n' % symbol
-    yield '#include <pb.h>\n\n'
+    try:
+        yield options.libformat % ('pb.h')
+    except TypeError:
+        # no %s specified - use whatever was passed in as options.libformat
+        yield options.libformat
+    yield '\n'
     
     for dependency in dependencies:
         noext = os.path.splitext(dependency)[0]
-        yield '#include "%s.%s.h"\n' % (noext,options.extension)
+        yield options.genformat % (noext + '.' + options.extension + '.h')
+        yield '\n'
 
     yield '#ifdef __cplusplus\n'
     yield 'extern "C" {\n'
@@ -490,7 +506,8 @@ def generate_source(headername, enums, messages):
     
     yield '/* Automatically generated nanopb constant definitions */\n'
     yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime())
-    yield '#include "%s"\n\n' % headername
+    yield options.genformat % (headername)
+    yield '\n'
     
     for msg in messages:
         yield msg.default_decl(False)
@@ -566,36 +583,46 @@ def generate_source(headername, enums, messages):
     
     yield '\n'
 
-
 # ---------------------------------------------------------------------------
-#                         Command line interface
+#                    Options parsing for the .proto files
 # ---------------------------------------------------------------------------
 
-import sys
+from fnmatch import fnmatch
-import os.path    
-from optparse import OptionParser
-import google.protobuf.text_format as text_format
 
-optparser = OptionParser(
+def read_options_file(infile):
-    usage = "Usage: nanopb_generator.py [options] file.pb ...",
+    '''Parse a separate options file to list:
-    epilog = "Compile file.pb from file.proto by: 'protoc -ofile.pb file.proto'. " +
+        [(namemask, options), ...]
-             "Output will be written to file.pb.h and file.pb.c.")
+    '''
-optparser.add_option("-x", dest="exclude", metavar="FILE", action="append", default=[],
+    results = []
-    help="Exclude file from generated #include list.")
+    for line in infile:
-optparser.add_option("-e", "--extension", dest="extension", metavar="EXTENSION", default="pb",
+        line = line.strip()
-    help="use extension instead of 'pb' for generated files.")
+        if not line or line.startswith('//') or line.startswith('#'):
-optparser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False,
+            continue
-    help="Don't print anything except errors.")
-optparser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
-    help="Print more information.")
-optparser.add_option("-s", dest="settings", metavar="OPTION:VALUE", action="append", default=[],
-    help="Set generator option (max_size, max_count etc.).")
         
-def get_nanopb_suboptions(subdesc, options):
+        parts = line.split(None, 1)
+        opts = nanopb_pb2.NanoPBOptions()
+        text_format.Merge(parts[1], opts)
+        results.append((parts[0], opts))
+
+    return results
+
+class Globals:
+    '''Ugly global variables, should find a good way to pass these.'''
+    verbose_options = False
+    separate_options = []
+
+def get_nanopb_suboptions(subdesc, options, name):
     '''Get copy of options, and merge information from subdesc.'''
     new_options = nanopb_pb2.NanoPBOptions()
     new_options.CopyFrom(options)
     
+    # Handle options defined in a separate file
+    dotname = '.'.join(name.parts)
+    for namemask, options in Globals.separate_options:
+        if fnmatch(dotname, namemask):
+            new_options.MergeFrom(options)
+    
+    # Handle options defined in .proto
     if isinstance(subdesc.options, descriptor.FieldOptions):
         ext_type = nanopb_pb2.nanopb
     elif isinstance(subdesc.options, descriptor.FileOptions):
@@ -611,8 +638,44 @@ def get_nanopb_suboptions(subdesc, options):
         ext = subdesc.options.Extensions[ext_type]
         new_options.MergeFrom(ext)
     
+    if Globals.verbose_options:
+        print "Options for " + dotname + ":"
+        print text_format.MessageToString(new_options)
+    
     return new_options
 
+
+# ---------------------------------------------------------------------------
+#                         Command line interface
+# ---------------------------------------------------------------------------
+
+import sys
+import os.path    
+from optparse import OptionParser
+
+optparser = OptionParser(
+    usage = "Usage: nanopb_generator.py [options] file.pb ...",
+    epilog = "Compile file.pb from file.proto by: 'protoc -ofile.pb file.proto'. " +
+             "Output will be written to file.pb.h and file.pb.c.")
+optparser.add_option("-x", dest="exclude", metavar="FILE", action="append", default=[],
+    help="Exclude file from generated #include list.")
+optparser.add_option("-e", "--extension", dest="extension", metavar="EXTENSION", default="pb",
+    help="Set extension to use instead of 'pb' for generated files. [default: %default]")
+optparser.add_option("-f", "--options-file", dest="options_file", metavar="FILE", default="%s.options",
+    help="Set name of a separate generator options file.")
+optparser.add_option("-Q", "--generated-include-format", dest="genformat",
+    metavar="FORMAT", default='#include "%s"\n',
+    help="Set format string to use for including other .pb.h files. [default: %default]")
+optparser.add_option("-L", "--library-include-format", dest="libformat",
+    metavar="FORMAT", default='#include <%s>\n',
+    help="Set format string to use for including the nanopb pb.h header. [default: %default]")
+optparser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False,
+    help="Don't print anything except errors.")
+optparser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
+    help="Print more information.")
+optparser.add_option("-s", dest="settings", metavar="OPTION:VALUE", action="append", default=[],
+    help="Set generator option (max_size, max_count etc.).")
+
 def process(filenames, options):
     '''Process the files given on the command line.'''
     
@@ -623,6 +686,8 @@ def process(filenames, options):
     if options.quiet:
         options.verbose = False
 
+    Globals.verbose_options = options.verbose
+    
     toplevel_options = nanopb_pb2.NanoPBOptions()
     for s in options.settings:
         text_format.Merge(s, toplevel_options)
@@ -631,12 +696,23 @@ def process(filenames, options):
         data = open(filename, 'rb').read()
         fdesc = descriptor.FileDescriptorSet.FromString(data)
         
-        file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options)
+        # Check if any separate options are specified
+        try:
+            optfilename = options.options_file % os.path.splitext(filename)[0]
+        except TypeError:
+            # No %s specified, use the filename as-is
+            optfilename = options.options_file
         
         if options.verbose:
-            print "Options for " + filename + ":"
+            print 'Reading options from ' + optfilename
-            print text_format.MessageToString(file_options)
         
+        if os.path.isfile(optfilename):
+            Globals.separate_options = read_options_file(open(optfilename, "rU"))
+        else:
+            Globals.separate_options = []
+        
+        # Parse the file
+        file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options, Names([filename]))
         enums, messages = parse_file(fdesc.file[0], file_options)
         
         noext = os.path.splitext(filename)[0]

pb.h

@@ -6,17 +6,40 @@
  * see pb_encode.h or pb_decode.h
  */
 
-#define NANOPB_VERSION nanopb-0.2.0
+#define NANOPB_VERSION nanopb-0.2.1-dev
 
+#ifdef PB_SYSTEM_HEADER
+#include PB_SYSTEM_HEADER
+#else
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <string.h>
+#endif
 
-#ifdef __GNUC__
+/* Macro for defining packed structures (compiler dependent).
-/* This just reduces memory requirements, but is not required. */
+ * This just reduces memory requirements, but is not required.
-#define pb_packed __attribute__((packed))
+ */
+#if 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__)
+    /* For IAR ARM compiler */
+#   define PB_PACKED_STRUCT_START _Pragma("pack(push, 1)")
+#   define PB_PACKED_STRUCT_END _Pragma("pack(pop)")
+#   define pb_packed
+#elif defined(_MSC_VER)
+    /* 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
-#define pb_packed
+    /* Unknown compiler */
+#   define PB_PACKED_STRUCT_START
+#   define PB_PACKED_STRUCT_END
+#   define pb_packed
 #endif
 
 /* Handly macro for suppressing unreferenced-parameter compiler warnings.    */
@@ -113,6 +136,7 @@ typedef uint8_t pb_type_t;
  * structures. Fix that by defining PB_FIELD_16BIT or
  * PB_FIELD_32BIT.
  */
+PB_PACKED_STRUCT_START
 typedef struct _pb_field_t pb_field_t;
 struct _pb_field_t {
 
@@ -144,6 +168,7 @@ struct _pb_field_t {
      * If null, then field will zeroed. */
     const void *ptr;
 } pb_packed;
+PB_PACKED_STRUCT_END
 
 /* This structure is used for 'bytes' arrays.
  * It has the number of bytes in the beginning, and after that an array.
@@ -178,10 +203,19 @@ 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 {
+#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;
@@ -199,7 +233,7 @@ typedef enum {
 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
 #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) \
+#define pb_delta_end(st, m1, m2) (int)(offsetof(st, m1) == offsetof(st, m2) \
                                   ? offsetof(st, m1) \
                                   : offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}

pb_decode.c

@@ -14,7 +14,6 @@
 #define NANOPB_INTERNALS
 #include "pb.h"
 #include "pb_decode.h"
-#include <string.h>
 
 typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest) checkreturn;
 
@@ -280,7 +279,7 @@ void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
 /* Iterator for pb_field_t list */
 typedef struct {
     const pb_field_t *start; /* Start of the pb_field_t array */
-    const pb_field_t *current; /* Current position of the iterator */
+    const pb_field_t *pos; /* Current position of the iterator */
     unsigned field_index; /* Zero-based index of the field. */
     unsigned required_field_index; /* Zero-based index that counts only the required fields */
     void *dest_struct; /* Pointer to the destination structure to decode to */
@@ -290,33 +289,36 @@ typedef struct {
 
 static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct)
 {
-    iter->start = iter->current = fields;
+    iter->start = iter->pos = fields;
     iter->field_index = 0;
     iter->required_field_index = 0;
-    iter->pData = (char*)dest_struct + iter->current->data_offset;
+    iter->pData = (char*)dest_struct + iter->pos->data_offset;
-    iter->pSize = (char*)iter->pData + iter->current->size_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
     iter->dest_struct = dest_struct;
 }
 
 static bool pb_field_next(pb_field_iterator_t *iter)
 {
     bool notwrapped = true;
-    size_t prev_size = iter->current->data_size;
+    size_t prev_size = iter->pos->data_size;
     
-    if (PB_ATYPE(iter->current->type) == PB_ATYPE_STATIC &&
+    if (PB_ATYPE(iter->pos->type) == PB_ATYPE_STATIC &&
-        PB_HTYPE(iter->current->type) == PB_HTYPE_REPEATED)
+        PB_HTYPE(iter->pos->type) == PB_HTYPE_REPEATED)
     {
-        prev_size *= iter->current->array_size;
+        prev_size *= iter->pos->array_size;
     }
     
-    if (PB_HTYPE(iter->current->type) == PB_HTYPE_REQUIRED)
+    if (PB_HTYPE(iter->pos->type) == PB_HTYPE_REQUIRED)
         iter->required_field_index++;
     
-    iter->current++;
+    if (iter->pos->tag == 0)
+        return false; /* Only happens with empty message types */
+    
+    iter->pos++;
     iter->field_index++;
-    if (iter->current->tag == 0)
+    if (iter->pos->tag == 0)
     {
-        iter->current = iter->start;
+        iter->pos = iter->start;
         iter->field_index = 0;
         iter->required_field_index = 0;
         iter->pData = iter->dest_struct;
@@ -324,24 +326,11 @@ static bool pb_field_next(pb_field_iterator_t *iter)
         notwrapped = false;
     }
     
-    iter->pData = (char*)iter->pData + prev_size + iter->current->data_offset;
+    iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
-    iter->pSize = (char*)iter->pData + iter->current->size_offset;
+    iter->pSize = (char*)iter->pData + iter->pos->size_offset;
     return notwrapped;
 }
 
-static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag)
-{
-    unsigned start = iter->field_index;
-    
-    do {
-        if (iter->current->tag == tag)
-            return true;
-        pb_field_next(iter);
-    } while (iter->field_index != start);
-    
-    return false;
-}
-
 /*************************
  * Decode a single field *
  *************************/
@@ -351,17 +340,17 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
     pb_type_t type;
     pb_decoder_t func;
     
-    type = iter->current->type;
+    type = iter->pos->type;
     func = PB_DECODERS[PB_LTYPE(type)];
 
     switch (PB_HTYPE(type))
     {
         case PB_HTYPE_REQUIRED:
-            return func(stream, iter->current, iter->pData);
+            return func(stream, iter->pos, iter->pData);
             
         case PB_HTYPE_OPTIONAL:
             *(bool*)iter->pSize = true;
-            return func(stream, iter->current, iter->pData);
+            return func(stream, iter->pos, iter->pData);
     
         case PB_HTYPE_REPEATED:
             if (wire_type == PB_WT_STRING
@@ -374,10 +363,10 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
                 if (!pb_make_string_substream(stream, &substream))
                     return false;
                 
-                while (substream.bytes_left && *size < iter->current->array_size)
+                while (substream.bytes_left && *size < iter->pos->array_size)
                 {
-                    void *pItem = (uint8_t*)iter->pData + iter->current->data_size * (*size);
+                    void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
-                    if (!func(&substream, iter->current, pItem))
+                    if (!func(&substream, iter->pos, pItem))
                     {
                         status = false;
                         break;
@@ -395,12 +384,12 @@ static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t
             {
                 /* Repeated field */
                 size_t *size = (size_t*)iter->pSize;
-                void *pItem = (uint8_t*)iter->pData + iter->current->data_size * (*size);
+                void *pItem = (uint8_t*)iter->pData + iter->pos->data_size * (*size);
-                if (*size >= iter->current->array_size)
+                if (*size >= iter->pos->array_size)
                     PB_RETURN_ERROR(stream, "array overflow");
                 
                 (*size)++;
-                return func(stream, iter->current, pItem);
+                return func(stream, iter->pos, pItem);
             }
 
         default:
@@ -412,6 +401,12 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
 {
     pb_callback_t *pCallback = (pb_callback_t*)iter->pData;
     
+#ifdef PB_OLD_CALLBACK_STYLE
+    void *arg = pCallback->arg;
+#else
+    void **arg = &(pCallback->arg);
+#endif
+    
     if (pCallback->funcs.decode == NULL)
         return pb_skip_field(stream, wire_type);
     
@@ -424,7 +419,7 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
         
         while (substream.bytes_left)
         {
-            if (!pCallback->funcs.decode(&substream, iter->current, pCallback->arg))
+            if (!pCallback->funcs.decode(&substream, iter->pos, arg))
                 PB_RETURN_ERROR(stream, "callback failed");
         }
         
@@ -445,13 +440,13 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
             return false;
         substream = pb_istream_from_buffer(buffer, size);
         
-        return pCallback->funcs.decode(&substream, iter->current, pCallback->arg);
+        return pCallback->funcs.decode(&substream, iter->pos, arg);
     }
 }
 
 static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter)
 {
-    switch (PB_ATYPE(iter->current->type))
+    switch (PB_ATYPE(iter->pos->type))
     {
         case PB_ATYPE_STATIC:
             return decode_static_field(stream, wire_type, iter);
@@ -464,71 +459,105 @@ static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_t
     }
 }
 
-/* Initialize message fields to default values, recursively */
+/* Set field count to zero (or clear has_ field). */
-static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct)
+static void pb_clear_field_count(const pb_field_iterator_t *iter)
 {
-    pb_field_iterator_t iter;
+    pb_type_t type;
-    pb_field_init(&iter, fields, dest_struct);
+    type = iter->pos->type;
     
-    /* Initialize size/has fields and apply default values */
+    if (iter->pos->tag == 0)
-    do
+        return; /* Empty message type */
+
+    if (PB_ATYPE(type) == PB_ATYPE_STATIC)
     {
-        pb_type_t type;
+        if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL)
-        type = iter.current->type;
-    
-        if (iter.current->tag == 0)
-            continue;
-        
-        if (PB_ATYPE(type) == PB_ATYPE_STATIC)
         {
-            /* Initialize the size field for optional/repeated fields to 0. */
+            *(bool*)iter->pSize = false;
-            if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL)
-            {
-                *(bool*)iter.pSize = false;
-            }
-            else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
-            {
-                *(size_t*)iter.pSize = 0;
-                continue; /* Array is empty, no need to initialize contents */
-            }
-            
-            /* Initialize field contents to default value */
-            if (PB_LTYPE(iter.current->type) == PB_LTYPE_SUBMESSAGE)
-            {
-                pb_message_set_to_defaults((const pb_field_t *) iter.current->ptr, iter.pData);
-            }
-            else if (iter.current->ptr != NULL)
-            {
-                memcpy(iter.pData, iter.current->ptr, iter.current->data_size);
-            }
-            else
-            {
-                memset(iter.pData, 0, iter.current->data_size);
-            }
         }
-        else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
+        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED)
         {
-            continue; /* Don't overwrite callback */
+            *(size_t*)iter->pSize = 0;
         }
-    } while (pb_field_next(&iter));
+    }
+}
+
+/* Initialize message field to default value. Recurses on submessages. */
+static void pb_set_field_to_default(const pb_field_iterator_t *iter)
+{
+    pb_type_t type;
+    type = iter->pos->type;
+
+    if (iter->pos->tag == 0)
+        return; /* Empty message type */
+
+    /* We only need to initialize static fields.
+     * Furthermore, arrays do not need to be initialized as their length
+     * will be zero by default.
+     */
+    if (PB_ATYPE(type) == PB_ATYPE_STATIC &&
+        PB_HTYPE(type) != PB_HTYPE_REPEATED)
+    {
+        if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
+        {
+            /* Submessage: initialize the fields recursively */
+            pb_field_iterator_t subiter;
+            pb_field_init(&subiter, (const pb_field_t *)iter->pos->ptr, iter->pData);
+            do {
+                pb_clear_field_count(&subiter);
+                pb_set_field_to_default(&subiter);
+            } while (pb_field_next(&subiter));
+        }
+        else if (iter->pos->ptr != NULL)
+        {
+            /* Normal field: copy the default value */
+            memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
+        }
+        else
+        {
+            /* Normal field without default value: initialize to zero */
+            memset(iter->pData, 0, iter->pos->data_size);
+        }
+    }
 }
 
 /*********************
  * Decode all fields *
  *********************/
 
-bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+/* Helper function to initialize fields while advancing iterator */
+static void advance_iterator(pb_field_iterator_t *iter, bool *initialize, bool *current_seen)
+{
+    /* Initialize the fields we didn't decode. */
+    if (*initialize && !*current_seen)
+        pb_set_field_to_default(iter);
+    
+    /* Stop initializing after the first pass through the array */
+    if (!pb_field_next(iter))
+        *initialize = false;
+    
+    /* Clear the field count before decoding */
+    if (*initialize)
+        pb_clear_field_count(iter);
+    
+    /* Reset the flag to indicate that the new field has not been written to yet. */
+    *current_seen = false;
+}
+
+static bool checkreturn pb_decode_inner(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct, bool initialize)
 {
     uint8_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 7) / 8] = {0}; /* Used to check for required fields */
+    bool current_seen = false;
     pb_field_iterator_t iter;
-    
     pb_field_init(&iter, fields, dest_struct);
+    pb_clear_field_count(&iter);
     
     while (stream->bytes_left)
     {
         uint32_t tag;
         pb_wire_type_t wire_type;
         bool eof;
+        unsigned start;
+        bool skip = false;
         
         if (!pb_decode_tag(stream, &wire_type, &tag, &eof))
         {
@@ -538,20 +567,45 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
                 return false;
         }
         
-        if (!pb_field_find(&iter, tag))
+        /* Go through the fields until we either find a match or
+         * wrap around to start. On the first pass, also initialize
+         * any missing fields.
+         * 
+         * The logic here is to avoid unnecessary initialization
+         * in the common case, where all fields occur in the proper
+         * order.
+         */
+        start = iter.field_index;
+        while (iter.pos->tag != tag)
+        {
+            advance_iterator(&iter, &initialize, &current_seen);
+            
+            if (iter.field_index == start)
+            {
+                skip = true;
+                break;
+            }
+        }
+        
+        /* Skip data if field was not found */
+        if (skip)
         {
-            /* No match found, skip data */
             if (!pb_skip_field(stream, wire_type))
                 return false;
+
             continue;
         }
         
-        if (PB_HTYPE(iter.current->type) == PB_HTYPE_REQUIRED
+        current_seen = true;
+        
+        /* Keep track if all required fields are present */
+        if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REQUIRED
             && iter.required_field_index < PB_MAX_REQUIRED_FIELDS)
         {
             fields_seen[iter.required_field_index >> 3] |= (uint8_t)(1 << (iter.required_field_index & 7));
         }
             
+        /* Finally, decode the field data */
         if (!decode_field(stream, wire_type, &iter))
             return false;
     }
@@ -561,17 +615,21 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
         /* First figure out the number of required fields by
          * seeking to the end of the field array. Usually we
          * are already close to end after decoding.
+         *
+         * Note: this simultaneously initializes any fields
+         * that haven't been already initialized.
          */
         unsigned req_field_count;
         pb_type_t last_type;
         unsigned i;
         do {
             req_field_count = iter.required_field_index;
-            last_type = iter.current->type;
+            last_type = iter.pos->type;
-        } while (pb_field_next(&iter));
+            advance_iterator(&iter, &initialize, &current_seen);
+        } while (iter.field_index != 0);
         
         /* Fixup if last field was also required. */
-        if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED)
+        if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag)
             req_field_count++;
         
         /* Check the whole bytes */
@@ -589,10 +647,14 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[
     return true;
 }
 
+bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
+{
+    return pb_decode_inner(stream, fields, dest_struct, false);
+}
+
 bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
 {
-    pb_message_set_to_defaults(fields, dest_struct);
+    return pb_decode_inner(stream, fields, dest_struct, true);
-    return pb_decode_noinit(stream, fields, dest_struct);
 }
 
 /* Field decoders */
@@ -741,12 +803,7 @@ bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field
     if (field->ptr == NULL)
         PB_RETURN_ERROR(stream, "invalid field descriptor");
     
-    /* New array entries need to be initialized, while required and optional
+    status = pb_decode(&substream, submsg_fields, dest);
-     * submessages have already been initialized in the top-level pb_decode. */
-    if (PB_HTYPE(field->type) == PB_HTYPE_REPEATED)
-        status = pb_decode(&substream, submsg_fields, dest);
-    else
-        status = pb_decode_noinit(&substream, submsg_fields, dest);
     
     pb_close_string_substream(stream, &substream);
     return status;

pb_decode.h

@@ -62,6 +62,9 @@ bool pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struc
 /* Same as pb_decode, except does not initialize the destination structure
  * to default values. This is slightly faster if you need no default values
  * and just do memset(struct, 0, sizeof(struct)) yourself.
+ *
+ * It can also be used to merge fields from a new message into a previously
+ * initialized structure.
  */
 bool pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
 

pb_encode.c

@@ -6,7 +6,6 @@
 #define NANOPB_INTERNALS
 #include "pb.h"
 #include "pb_encode.h"
-#include <string.h>
 
 /* The warn_unused_result attribute appeared first in gcc-3.4.0 */
 #if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
@@ -56,6 +55,9 @@ pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize)
     stream.state = buf;
     stream.max_size = bufsize;
     stream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    stream.errmsg = NULL;
+#endif
     return stream;
 }
 
@@ -64,14 +66,14 @@ bool checkreturn pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count
     if (stream->callback != NULL)
     {
         if (stream->bytes_written + count > stream->max_size)
-            return false;
+            PB_RETURN_ERROR(stream, "stream full");
 
 #ifdef PB_BUFFER_ONLY
         if (!buf_write(stream, buf, count))
-            return false;
+            PB_RETURN_ERROR(stream, "io error");
 #else        
         if (!stream->callback(stream, buf, count))
-            return false;
+            PB_RETURN_ERROR(stream, "io error");
 #endif
     }
     
@@ -111,7 +113,7 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie
         }
         else
         {
-            pb_ostream_t sizestream = {0,0,0,0};
+            pb_ostream_t sizestream = PB_OSTREAM_SIZING;
             p = pData;
             for (i = 0; i < count; i++)
             {
@@ -187,7 +189,7 @@ bool checkreturn encode_static_field(pb_ostream_t *stream, const pb_field_t *fie
             break;
         
         default:
-            return false;
+            PB_RETURN_ERROR(stream, "invalid field type");
     }
     
     return true;
@@ -196,10 +198,17 @@ bool checkreturn encode_static_field(pb_ostream_t *stream, const pb_field_t *fie
 bool checkreturn encode_callback_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData)
 {
     const pb_callback_t *callback = (const pb_callback_t*)pData;
+    
+#ifdef PB_OLD_CALLBACK_STYLE
+    const void *arg = callback->arg;
+#else
+    void * const *arg = &(callback->arg);
+#endif    
+    
     if (callback->funcs.encode != NULL)
     {
-        if (!callback->funcs.encode(stream, field, callback->arg))
+        if (!callback->funcs.encode(stream, field, arg))
-            return false;
+            PB_RETURN_ERROR(stream, "callback error");
     }
     return true;
 }
@@ -235,7 +244,7 @@ bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], cons
                 break;
             
             default:
-                return false;
+                PB_RETURN_ERROR(stream, "invalid field type");
         }
     
         field++;
@@ -340,7 +349,7 @@ bool checkreturn pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t
             break;
         
         default:
-            return false;
+            PB_RETURN_ERROR(stream, "invalid field type");
     }
     
     return pb_encode_tag(stream, wiretype, field->tag);
@@ -357,7 +366,7 @@ bool checkreturn pb_encode_string(pb_ostream_t *stream, const uint8_t *buffer, s
 bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
 {
     /* First calculate the message size using a non-writing substream. */
-    pb_ostream_t substream = {0,0,0,0};
+    pb_ostream_t substream = PB_OSTREAM_SIZING;
     size_t size;
     bool status;
     
@@ -373,7 +382,7 @@ bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fie
         return pb_write(stream, NULL, size); /* Just sizing */
     
     if (stream->bytes_written + size > stream->max_size)
-        return false;
+        PB_RETURN_ERROR(stream, "stream full");
         
     /* Use a substream to verify that a callback doesn't write more than
      * what it did the first time. */
@@ -381,14 +390,20 @@ bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fie
     substream.state = stream->state;
     substream.max_size = size;
     substream.bytes_written = 0;
+#ifndef PB_NO_ERRMSG
+    substream.errmsg = NULL;
+#endif
     
     status = pb_encode(&substream, fields, src_struct);
     
     stream->bytes_written += substream.bytes_written;
     stream->state = substream.state;
+#ifndef PB_NO_ERRMSG
+    stream->errmsg = substream.errmsg;
+#endif
     
     if (substream.bytes_written != size)
-        return false;
+        PB_RETURN_ERROR(stream, "submsg size changed");
     
     return status;
 }
@@ -405,7 +420,7 @@ bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, co
         case 2: value = *(const uint16_t*)src; break;
         case 4: value = *(const uint32_t*)src; break;
         case 8: value = *(const uint64_t*)src; break;
-        default: return false;
+        default: PB_RETURN_ERROR(stream, "invalid data_size");
     }
     
     return pb_encode_varint(stream, value);
@@ -419,7 +434,7 @@ bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, c
     {
         case 4: value = *(const int32_t*)src; break;
         case 8: value = *(const int64_t*)src; break;
-        default: return false;
+        default: PB_RETURN_ERROR(stream, "invalid data_size");
     }
     
     return pb_encode_svarint(stream, value);
@@ -453,7 +468,7 @@ bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, co
 bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src)
 {
     if (field->ptr == NULL)
-        return false;
+        PB_RETURN_ERROR(stream, "invalid field descriptor");
     
     return pb_encode_submessage(stream, (const pb_field_t*)field->ptr, src);
 }

pb_encode.h

@@ -46,11 +46,22 @@ struct _pb_ostream_t
     void *state; /* Free field for use by callback implementation */
     size_t max_size; /* Limit number of output bytes written (or use SIZE_MAX). */
     size_t bytes_written;
+    
+#ifndef PB_NO_ERRMSG
+    const char *errmsg;
+#endif
 };
 
 pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize);
 bool pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count);
 
+/* Stream type for use in computing message sizes */
+#ifndef PB_NO_ERRMSG
+#define PB_OSTREAM_SIZING {0,0,0,0,0}
+#else
+#define PB_OSTREAM_SIZING {0,0,0,0}
+#endif
+
 /* Encode struct to given output stream.
  * Returns true on success, false on any failure.
  * The actual struct pointed to by src_struct must match the description in fields.

tests/Makefile

@@ -15,13 +15,21 @@ CC_VERSION=$(shell $(CC) -v 2>&1)
 CFLAGS_CORE=
 ifneq (,$(findstring gcc,$(CC_VERSION)))
 	CFLAGS_CORE=-pedantic -Wextra -Wcast-qual -Wlogical-op -Wconversion
-        CFLAGS+=--coverage
+	CFLAGS+=--coverage -fstack-protector-all
-        LDFLAGS+=--coverage
+	LDFLAGS+=--coverage
 endif
 ifneq (,$(findstring clang,$(CC_VERSION)))
 	CFLAGS_CORE=-pedantic -Wextra -Wcast-qual -Wconversion
 endif
 
+# Also use mudflap if it is available
+# To enable, run with    make -B USE_MUDFLAP=y
+USE_MUDFLAP ?= n
+ifeq ($(USE_MUDFLAP),y)
+	CFLAGS += -fmudflap
+	LDFLAGS += -lmudflap -fmudflap
+endif
+
 all: breakpoints $(TESTS) run_unittests
 
 clean:
@@ -127,5 +135,5 @@ test_options: options.pb.h options.expected options.pb.o
 	    fi \
 	done
 
-run_fuzztest: test_decode2
+run_fuzztest: test_decode3
-	bash -c 'I=1; while true; do cat /dev/urandom | ./test_decode2 > /dev/null; I=$$(($$I+1)); echo -en "\r$$I"; done'
+	bash -c 'ulimit -c unlimited; I=1; while true; do cat /dev/urandom | ./test_decode3 > /dev/null; I=$$(($$I+1)); echo -en "\r$$I"; done'

tests/alltypes.options

@@ -0,0 +1,3 @@
+* max_size:16
+* max_count:5
+

tests/alltypes.proto

@@ -1,11 +1,13 @@
-import "nanopb.proto";
-
 message SubMessage {
-    required string substuff1 = 1 [(nanopb).max_size = 16, default = "1"];
+    required string substuff1 = 1 [default = "1"];
     required int32 substuff2 = 2 [default = 2];
     optional fixed32 substuff3 = 3 [default = 3];
 }
 
+message EmptyMessage {
+
+}
+
 enum MyEnum {
     Zero = 0;
     First = 1;
@@ -30,32 +32,34 @@ message AllTypes {
     required sfixed64   req_sfixed64= 12;
     required double     req_double  = 13;
     
-    required string     req_string  = 14 [(nanopb).max_size = 16];
+    required string     req_string  = 14;
-    required bytes      req_bytes   = 15 [(nanopb).max_size = 16];
+    required bytes      req_bytes   = 15;
     required SubMessage req_submsg  = 16;
     required MyEnum     req_enum    = 17;
+    required EmptyMessage req_emptymsg = 18;
     
     
-    repeated int32      rep_int32   = 21 [(nanopb).max_count = 5];
+    repeated int32      rep_int32   = 21;
-    repeated int64      rep_int64   = 22 [(nanopb).max_count = 5];
+    repeated int64      rep_int64   = 22;
-    repeated uint32     rep_uint32  = 23 [(nanopb).max_count = 5];
+    repeated uint32     rep_uint32  = 23;
-    repeated uint64     rep_uint64  = 24 [(nanopb).max_count = 5];
+    repeated uint64     rep_uint64  = 24;
-    repeated sint32     rep_sint32  = 25 [(nanopb).max_count = 5];
+    repeated sint32     rep_sint32  = 25;
-    repeated sint64     rep_sint64  = 26 [(nanopb).max_count = 5];
+    repeated sint64     rep_sint64  = 26;
-    repeated bool       rep_bool    = 27 [(nanopb).max_count = 5];
+    repeated bool       rep_bool    = 27;
     
-    repeated fixed32    rep_fixed32 = 28 [(nanopb).max_count = 5];
+    repeated fixed32    rep_fixed32 = 28;
-    repeated sfixed32   rep_sfixed32= 29 [(nanopb).max_count = 5];
+    repeated sfixed32   rep_sfixed32= 29;
-    repeated float      rep_float   = 30 [(nanopb).max_count = 5];
+    repeated float      rep_float   = 30;
     
-    repeated fixed64    rep_fixed64 = 31 [(nanopb).max_count = 5];
+    repeated fixed64    rep_fixed64 = 31;
-    repeated sfixed64   rep_sfixed64= 32 [(nanopb).max_count = 5];
+    repeated sfixed64   rep_sfixed64= 32;
-    repeated double     rep_double  = 33 [(nanopb).max_count = 5];
+    repeated double     rep_double  = 33;
     
-    repeated string     rep_string  = 34 [(nanopb).max_size = 16, (nanopb).max_count = 5];
+    repeated string     rep_string  = 34;
-    repeated bytes      rep_bytes   = 35 [(nanopb).max_size = 16, (nanopb).max_count = 5];
+    repeated bytes      rep_bytes   = 35;
-    repeated SubMessage rep_submsg  = 36 [(nanopb).max_count = 5];
+    repeated SubMessage rep_submsg  = 36;
-    repeated MyEnum     rep_enum    = 37 [(nanopb).max_count = 5];
+    repeated MyEnum     rep_enum    = 37;
+    repeated EmptyMessage rep_emptymsg = 38;
     
     optional int32      opt_int32   = 41 [default = 4041];
     optional int64      opt_int64   = 42 [default = 4042];
@@ -73,10 +77,11 @@ message AllTypes {
     optional sfixed64   opt_sfixed64= 52 [default = 4052];
     optional double     opt_double  = 53 [default = 4053];
     
-    optional string     opt_string  = 54 [(nanopb).max_size = 16, default = "4054"];
+    optional string     opt_string  = 54 [default = "4054"];
-    optional bytes      opt_bytes   = 55 [(nanopb).max_size = 16, default = "4055"];
+    optional bytes      opt_bytes   = 55 [default = "4055"];
     optional SubMessage opt_submsg  = 56;
     optional MyEnum     opt_enum    = 57 [default = Second];
+    optional EmptyMessage opt_emptymsg = 58;
 
     // Just to make sure that the size of the fields has been calculated
     // properly, i.e. otherwise a bug in last field might not be detected.

tests/bc_alltypes.pb.c

@@ -5,7 +5,7 @@
  * incompatible changes made to the generator in future versions.
  */
 
-#include "alltypes.pb.h"
+#include "bc_alltypes.pb.h"
 
 const char SubMessage_substuff1_default[16] = "1";
 const int32_t SubMessage_substuff2_default = 2;

tests/decode_unittests.c

@@ -19,11 +19,11 @@ bool stream_callback(pb_istream_t *stream, uint8_t *buf, size_t count)
 }
 
 /* Verifies that the stream passed to callback matches the byte array pointed to by arg. */
-bool callback_check(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool callback_check(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     int i;
     uint8_t byte;
-    pb_bytes_array_t *ref = (pb_bytes_array_t*) arg;
+    pb_bytes_array_t *ref = (pb_bytes_array_t*) *arg;
     
     for (i = 0; i < ref->size; i++)
     {

tests/encode_unittests.c

@@ -17,7 +17,7 @@ bool streamcallback(pb_ostream_t *stream, const uint8_t *buf, size_t count)
     return true;
 }
 
-bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     int value = 0x55;
     if (!pb_encode_tag_for_field(stream, field))
@@ -25,7 +25,7 @@ bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *ar
     return pb_encode_varint(stream, value);
 }
 
-bool crazyfieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool crazyfieldcallback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     /* This callback writes different amount of data the second time. */
     uint32_t *state = (uint32_t*)arg;

tests/test_decode3.c

@@ -76,6 +76,7 @@ bool check_alltypes(pb_istream_t *stream, int mode)
     TEST(alltypes.rep_submsg[4].substuff3 == 2016 && alltypes.rep_submsg[0].substuff3 == 3);
     
     TEST(alltypes.rep_enum_count == 5 && alltypes.rep_enum[4] == MyEnum_Truth && alltypes.rep_enum[0] == MyEnum_Zero);
+    TEST(alltypes.rep_emptymsg_count == 5);
     
     if (mode == 0)
     {
@@ -120,6 +121,7 @@ bool check_alltypes(pb_istream_t *stream, int mode)
         TEST(alltypes.opt_submsg.substuff3 == 3);
         TEST(alltypes.has_opt_enum     == false);
         TEST(alltypes.opt_enum == MyEnum_Second);
+        TEST(alltypes.has_opt_emptymsg == false);
     }
     else
     {
@@ -164,6 +166,7 @@ bool check_alltypes(pb_istream_t *stream, int mode)
         TEST(alltypes.opt_submsg.substuff3 == 3);
         TEST(alltypes.has_opt_enum      == true);
         TEST(alltypes.opt_enum == MyEnum_Truth);
+        TEST(alltypes.has_opt_emptymsg  == true);
     }
     
     TEST(alltypes.end == 1099);

tests/test_decode_callbacks.c

@@ -6,7 +6,7 @@
 #include <pb_decode.h>
 #include "callbacks.pb.h"
 
-bool print_string(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_string(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint8_t buffer[1024] = {0};
     
@@ -20,37 +20,37 @@ bool print_string(pb_istream_t *stream, const pb_field_t *field, void *arg)
     /* Print the string, in format comparable with protoc --decode.
      * Format comes from the arg defined in main().
      */
-    printf((char*)arg, buffer);
+    printf((char*)*arg, buffer);
     return true;
 }
 
-bool print_int32(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_int32(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint64_t value;
     if (!pb_decode_varint(stream, &value))
         return false;
     
-    printf((char*)arg, (long)value);
+    printf((char*)*arg, (long)value);
     return true;
 }
 
-bool print_fixed32(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_fixed32(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint32_t value;
     if (!pb_decode_fixed32(stream, &value))
         return false;
     
-    printf((char*)arg, (long)value);
+    printf((char*)*arg, (long)value);
     return true;
 }
 
-bool print_fixed64(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_fixed64(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint64_t value;
     if (!pb_decode_fixed64(stream, &value))
         return false;
     
-    printf((char*)arg, (long long)value);
+    printf((char*)*arg, (long long)value);
     return true;
 }
 

tests/test_encode1.c

@@ -27,6 +27,7 @@ int main()
     }
     else
     {
+        fprintf(stderr, "Encoding failed: %s\n", PB_GET_ERROR(&stream));
         return 1; /* Failure */
     }
 }

tests/test_encode2.c

@@ -26,7 +26,12 @@ int main()
     
     /* Now encode it and check if we succeeded. */
     if (pb_encode(&stream, Person_fields, &person))
+    {
         return 0; /* Success */
+    }
     else
+    {
+        fprintf(stderr, "Encoding failed: %s\n", PB_GET_ERROR(&stream));
         return 1; /* Failure */
+    }
 }

tests/test_encode3.c

@@ -64,6 +64,7 @@ int main(int argc, char **argv)
     alltypes.rep_submsg[4].substuff3 = 2016;
     
     alltypes.rep_enum_count = 5; alltypes.rep_enum[4] = MyEnum_Truth;
+    alltypes.rep_emptymsg_count = 5;
     
     if (mode != 0)
     {
@@ -107,6 +108,7 @@ int main(int argc, char **argv)
         alltypes.opt_submsg.substuff2 = 3056;
         alltypes.has_opt_enum = true;
         alltypes.opt_enum = MyEnum_Truth;
+        alltypes.has_opt_emptymsg = true;
     }
     
     alltypes.end = 1099;
@@ -122,7 +124,7 @@ int main(int argc, char **argv)
     }
     else
     {
-        fprintf(stderr, "Encoding failed!\n");
+        fprintf(stderr, "Encoding failed: %s\n", PB_GET_ERROR(&stream));
         return 1; /* Failure */
     }
 }

tests/test_encode_callbacks.c

@@ -5,7 +5,7 @@
 #include <pb_encode.h>
 #include "callbacks.pb.h"
 
-bool encode_string(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_string(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     char *str = "Hello world!";
     
@@ -15,7 +15,7 @@ bool encode_string(pb_ostream_t *stream, const pb_field_t *field, const void *ar
     return pb_encode_string(stream, (uint8_t*)str, strlen(str));
 }
 
-bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;
@@ -23,7 +23,7 @@ bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, const void *arg
     return pb_encode_varint(stream, 42);
 }
 
-bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;
@@ -32,7 +32,7 @@ bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *a
     return pb_encode_fixed32(stream, &value);
 }
 
-bool encode_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_fixed64(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;