Add field type FT_IGNORE to generator.

This allows ignoring fields that are unnecessary or too large for an
embedded system using nanopb, while allowing them to remain in the .proto
for other platforms.

Update issue 51
Status: FixedInGit

4 files changed, 24 insertions, 3 deletions

diff --git a/generator/nanopb.proto b/generator/nanopb.proto
index b9100abd..bc40f290 100644
--- a/generator/nanopb.proto
+++ b/generator/nanopb.proto
@@ -11,6 +11,7 @@ enum FieldType {
     FT_DEFAULT = 0; // Automatically decide field type, generate static field if possible.
     FT_CALLBACK = 1; // Always generate a callback field.
     FT_STATIC = 2; // Generate a static field or raise an exception if not possible.
+    FT_IGNORE = 3; // Ignore the field completely.
 }
 
 message NanoPBOptions {
diff --git a/generator/nanopb_generator.py b/generator/nanopb_generator.py
index a583b3f6..9e85a11d 100644
--- a/generator/nanopb_generator.py
+++ b/generator/nanopb_generator.py
@@ -306,7 +306,13 @@ class Field:
 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.fields = []
+        
+        for f in desc.field:
+            field_options = get_nanopb_suboptions(f, message_options)
+            if field_options.type != nanopb_pb2.FT_IGNORE:
+                self.fields.append(Field(self.name, f, field_options))
+        
         self.packed = message_options.packed_struct
         self.ordered_fields = self.fields[:]
         self.ordered_fields.sort()
diff --git a/generator/nanopb_pb2.py b/generator/nanopb_pb2.py
index d08b82ab..4ba18b26 100644
--- a/generator/nanopb_pb2.py
+++ b/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\"\x92\x01\n\rNanoPBOptions\x12\x10\n\x08max_size\x18\x01 \x01(\x05\x12\x11\n\tmax_count\x18\x02 \x01(\x05\x12$\n\x04type\x18\x03 \x01(\x0e\x32\n.FieldType:\nFT_DEFAULT\x12\x18\n\nlong_names\x18\x04 \x01(\x08:\x04true\x12\x1c\n\rpacked_struct\x18\x05 \x01(\x08:\x05\x66\x61lse*;\n\tFieldType\x12\x0e\n\nFT_DEFAULT\x10\x00\x12\x0f\n\x0b\x46T_CALLBACK\x10\x01\x12\r\n\tFT_STATIC\x10\x02:E\n\x0enanopb_fileopt\x12\x1c.google.protobuf.FileOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:G\n\rnanopb_msgopt\x12\x1f.google.protobuf.MessageOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:E\n\x0enanopb_enumopt\x12\x1c.google.protobuf.EnumOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions:>\n\x06nanopb\x12\x1d.google.protobuf.FieldOptions\x18\xf2\x07 \x01(\x0b\x32\x0e.NanoPBOptions')
+  serialized_pb='\n\x0cnanopb.proto\x1a google/protobuf/descriptor.proto\"\x92\x01\n\rNanoPBOptions\x12\x10\n\x08max_size\x18\x01 \x01(\x05\x12\x11\n\tmax_count\x18\x02 \x01(\x05\x12$\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*J\n\tFieldType\x12\x0e\n\nFT_DEFAULT\x10\x00\x12\x0f\n\x0b\x46T_CALLBACK\x10\x01\x12\r\n\tFT_STATIC\x10\x02\x12\r\n\tFT_IGNORE\x10\x03: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',
@@ -32,17 +32,22 @@ _FIELDTYPE = descriptor.EnumDescriptor(
       name='FT_STATIC', index=2, number=2,
       options=None,
       type=None),
+    descriptor.EnumValueDescriptor(
+      name='FT_IGNORE', index=3, number=3,
+      options=None,
+      type=None),
   ],
   containing_type=None,
   options=None,
   serialized_start=199,
-  serialized_end=258,
+  serialized_end=273,
 )
 
 
 FT_DEFAULT = 0
 FT_CALLBACK = 1
 FT_STATIC = 2
+FT_IGNORE = 3
 
 NANOPB_FILEOPT_FIELD_NUMBER = 1010
 nanopb_fileopt = descriptor.FieldDescriptor(
diff --git a/tests/options.proto b/tests/options.proto
index 3e9383cd..b5badcfd 100644
--- a/tests/options.proto
+++ b/tests/options.proto
@@ -62,3 +62,12 @@ message my_packed_struct
     optional int32 myfield = 1;
 }
 
+// Message with ignored field
+// Note: doesn't really test if the field is missing in the output,
+// but atleast tests that the output compiles.
+message Message6
+{
+    required int32 field1 = 1;
+    optional int32 field2 = 2 [(nanopb).type = FT_IGNORE];
+}
+