Modified nanopb_generator.py to generate includes for other .proto files.

Implementation was suggested by extremeblue99.
Fixes issue 4.

docs/reference.rst

@@ -376,7 +376,12 @@ Because of memory concerns, the detection of missing required fields is not perf
 
     Each field decoder reads and decodes a single value. For arrays, the decoder is called repeatedly.
 
-    You can use the decoders from your callbacks. Just be aware that the pb_field_t passed to the callback is not directly compatible with most of the field decoders. Instead, you must create a new pb_field_t structure and set the data_size according to the data type you pass to *dest*.
+    You can use the decoders from your callbacks. Just be aware that the pb_field_t passed to the callback is not directly compatible 
+    with the *varint* field decoders. Instead, you must create a new pb_field_t structure and set the data_size according to the data type 
+    you pass to *dest*, e.g. *field.data_size = sizeof(int);*. Other fields in the *pb_field_t* don't matter.
+
+    The field decoder interface is a bit messy as a result of the interface required inside the nanopb library.
+    Eventually they may be replaced by separate wrapper functions with a more friendly interface.
 
 pb_dec_varint
 -------------
@@ -403,12 +408,12 @@ pb_dec_fixed32
 --------------
 Field decoder for PB_LTYPE_FIXED32. ::
 
-    bool pb_dec_fixed(pb_istream_t *stream, const pb_field_t *field, void *dest);
+    bool pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest);
 
-:stream:        Input stream to read from. 1-10 bytes will be read.
+:stream:        Input stream to read from. 4 bytes will be read.
 :field:         Not used.
-:dest:          Pointer to destination integer. Must have size of *field->data_size* bytes.
-:returns:       True on success, false on IO errors or if `pb_decode_varint`_ fails.
+:dest:          Pointer to destination *int32_t*, *uint32_t* or *float*.
+:returns:       True on success, false on IO errors.
 
 This function reads 4 bytes from the input stream.
 On big endian architectures, it then reverses the order of the bytes.
@@ -420,6 +425,11 @@ Field decoder for PB_LTYPE_FIXED64. ::
 
     bool pb_dec_fixed(pb_istream_t *stream, const pb_field_t *field, void *dest);
 
+:stream:        Input stream to read from. 8 bytes will be read.
+:field:         Not used.
+:dest:          Pointer to destination *int64_t*, *uint64_t* or *double*.
+:returns:       True on success, false on IO errors.
+
 Same as `pb_dec_fixed32`_, except this reads 8 bytes.
 
 pb_dec_bytes
@@ -428,6 +438,9 @@ Field decoder for PB_LTYPE_BYTES. Reads a length-prefixed block of bytes. ::
 
     bool pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
 
+**Note:** This is an internal function that is not useful in decoder callbacks. To read bytes fields in callbacks, use 
+*stream->bytes_left* and `pb_read`_.
+
 :stream:        Input stream to read from.
 :field:         Field description structure. Only *field->data_size* matters.
 :dest:          Pointer to a structure similar to pb_bytes_array_t.
@@ -441,6 +454,9 @@ Field decoder for PB_LTYPE_STRING. Reads a length-prefixed string. ::
 
     bool pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest);
 
+**Note:** This is an internal function that is not useful in decoder callbacks. To read string fields in callbacks, use 
+*stream->bytes_left* and `pb_read`_.
+
 :stream:        Input stream to read from.
 :field:         Field description structure. Only *field->data_size* matters.
 :dest:          Pointer to a character array of size *field->data_size*.
@@ -454,6 +470,9 @@ Field decoder for PB_LTYPE_SUBMESSAGE. Calls `pb_decode`_ to perform the actual
 
     bool pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest)
 
+**Note:** This is an internal function that is not useful in decoder callbacks. To read submessage fields in callbacks, use 
+`pb_decode`_ directly.
+
 :stream:        Input stream to read from.
 :field:         Field description structure. Only *field->ptr* matters.
 :dest:          Pointer to the destination structure.

generator/nanopb_generator.py

@@ -347,7 +347,7 @@ def sort_dependencies(messages):
         if msgname in message_by_name:
             yield message_by_name[msgname]
 
-def generate_header(headername, enums, messages):
+def generate_header(dependencies, headername, enums, messages):
     '''Generate content for a header file.
     Generates strings, which should be concatenated and stored to file.
     '''
@@ -359,6 +359,11 @@ def generate_header(headername, enums, messages):
     yield '#define _PB_%s_\n' % symbol
     yield '#include <pb.h>\n\n'
     
+    for dependency in dependencies:
+        noext = os.path.splitext(dependency)[0]
+        yield '#include "%s.pb.h"\n' % noext
+    yield '\n'
+    
     yield '/* Enum definitions */\n'
     for enum in enums:
         yield str(enum) + '\n\n'
@@ -404,7 +409,7 @@ if __name__ == '__main__':
         print "Output fill be written to file.pb.h and file.pb.c"
         sys.exit(1)
     
-    data = open(sys.argv[1]).read()
+    data = open(sys.argv[1], 'rb').read()
     fdesc = descriptor.FileDescriptorSet.FromString(data)
     enums, messages = parse_file(fdesc.file[0])
     
@@ -415,8 +420,13 @@ if __name__ == '__main__':
     
     print "Writing to " + headername + " and " + sourcename
     
+    # List of .proto files that should not be included in the C header file
+    # even if they are mentioned in the source .proto.
+    excludes = ['nanopb.proto']
+    dependencies = [d for d in fdesc.file[0].dependency if d not in excludes]
+    
     header = open(headername, 'w')
-    for part in generate_header(headerbasename, enums, messages):
+    for part in generate_header(dependencies, headerbasename, enums, messages):
         header.write(part)
 
     source = open(sourcename, 'w')