Add generator option for packed structs.

Usage is:
message Foo
{
   option (nanopb_msgopt).packed_struct = true;
   ...
}

Valid also in file scope.

Update issue 49
Status: FixedInGit

generator/nanopb.proto

@@ -25,6 +25,9 @@ message NanoPBOptions {
   
   // Use long names for enums, i.e. EnumName_EnumValue.
   optional bool long_names = 4 [default = true];
+  
+  // Add 'packed' attribute to generated structs.
+  optional bool packed_struct = 5 [default = false];
 }
 
 // Protocol Buffers extension number registry

generator/nanopb_generator.py

@@ -307,6 +307,7 @@ class Message:
     def __init__(self, names, desc, message_options):
         self.name = names
         self.fields = [Field(self.name, f, get_nanopb_suboptions(f, message_options)) for f in desc.field]
+        self.packed = message_options.packed_struct
         self.ordered_fields = self.fields[:]
         self.ordered_fields.sort()
 
@@ -317,7 +318,12 @@ class Message:
     def __str__(self):
         result = 'typedef struct _%s {\n' % self.name
         result += '\n'.join([str(f) for f in self.ordered_fields])
-        result += '\n} %s;' % self.name
+        result += '\n}'
+        
+        if self.packed:
+            result += ' pb_packed'
+        
+        result += ' %s;' % self.name
         return result
     
     def types(self):

generator/nanopb_pb2.py

@@ -12,7 +12,7 @@ import google.protobuf.descriptor_pb2
 DESCRIPTOR = descriptor.FileDescriptor(
   name='nanopb.proto',
   package='',
-  serialized_pb='\n\x0cnanopb.proto\x1a google/protobuf/descriptor.proto\"t\n\rNanoPBOptions\x12\x10\n\x08max_size\x18\x01 \x01(\x05\x12\x11\n\tmax_count\x18\x02 \x01(\x05\x12$\n\x04type\x18\x03 \x01(\x0e\x32\n.FieldType:\nFT_DEFAULT\x12\x18\n\nlong_names\x18\x04 \x01(\x08:\x04true*;\n\tFieldType\x12\x0e\n\nFT_DEFAULT\x10\x00\x12\x0f\n\x0b\x46T_CALLBACK\x10\x01\x12\r\n\tFT_STATIC\x10\x02:E\n\x0enanopb_fileopt\x12\x1c.google.protobuf.FileOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:G\n\rnanopb_msgopt\x12\x1f.google.protobuf.MessageOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:E\n\x0enanopb_enumopt\x12\x1c.google.protobuf.EnumOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:>\n\x06nanopb\x12\x1d.google.protobuf.FieldOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions')
+  serialized_pb='\n\x0cnanopb.proto\x1a google/protobuf/descriptor.proto\"\x92\x01\n\rNanoPBOptions\x12\x10\n\x08max_size\x18\x01 \x01(\x05\x12\x11\n\tmax_count\x18\x02 \x01(\x05\x12$\n\x04type\x18\x03 \x01(\x0e\x32\n.FieldType:\nFT_DEFAULT\x12\x18\n\nlong_names\x18\x04 \x01(\x08:\x04true\x12\x1c\n\rpacked_struct\x18\x05 \x01(\x08:\x05\x66\x61lse*;\n\tFieldType\x12\x0e\n\nFT_DEFAULT\x10\x00\x12\x0f\n\x0b\x46T_CALLBACK\x10\x01\x12\r\n\tFT_STATIC\x10\x02:E\n\x0enanopb_fileopt\x12\x1c.google.protobuf.FileOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:G\n\rnanopb_msgopt\x12\x1f.google.protobuf.MessageOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:E\n\x0enanopb_enumopt\x12\x1c.google.protobuf.EnumOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:>\n\x06nanopb\x12\x1d.google.protobuf.FieldOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions')
 
 _FIELDTYPE = descriptor.EnumDescriptor(
   name='FieldType',
@@ -35,8 +35,8 @@ _FIELDTYPE = descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=168,
-  serialized_end=227,
+  serialized_start=199,
+  serialized_end=258,
 )
 
 
@@ -113,6 +113,13 @@ _NANOPBOPTIONS = descriptor.Descriptor(
       message_type=None, enum_type=None, containing_type=None,
       is_extension=False, extension_scope=None,
       options=None),
+    descriptor.FieldDescriptor(
+      name='packed_struct', full_name='NanoPBOptions.packed_struct', index=4,
+      number=5, type=8, cpp_type=7, label=1,
+      has_default_value=True, default_value=False,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
   ],
   extensions=[
   ],
@@ -122,8 +129,8 @@ _NANOPBOPTIONS = descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=50,
-  serialized_end=166,
+  serialized_start=51,
+  serialized_end=197,
 )
 
 _NANOPBOPTIONS.fields_by_name['type'].enum_type = _FIELDTYPE

tests/options.expected

@@ -4,3 +4,4 @@ char fieldsize\[40\];
 pb_callback_t int32_callback;
 \sEnumValue1 = 1
 Message5_EnumValue1
+} pb_packed my_packed_struct;

tests/options.proto

@@ -54,3 +54,11 @@ message Message5
     }
     required Enum2 field = 1 [default = EnumValue1];
 }
+
+// Packed structure
+message my_packed_struct
+{
+    option (nanopb_msgopt).packed_struct = true;
+    optional int32 myfield = 1;
+}
+