Nanopb strip package option raises error at import

Question

I am struggling with nanopb to get the enum of another package which has * mangle_names:M_STRIP_PACKAGE in .options file. Here is a way to reproduce the problem easily :

I have a root_folder containing folder_A and folder_B. In folder_A, I have file_A.proto and file_A.options :

file_A.proto:

syntax = "proto2";

package folder_A;

enum my_enum {
    ENUM_0 = 0;
    ENUM_1 = 1;
    ENUM_2 = 2;
}

file_A.options:

* mangle_names:M_STRIP_PACKAGE

In folder_B, I have file_B.proto :

syntax = "proto2";

package folder_B;

import "folder_A/file_A.proto";

message dummy  {
    required folder_A.my_enum value  = 1;
}

I try to generate proto file with the following command:

nanopb_generator.py -D . -I . -I .\folder_B\ .\folder_A\file_A.proto .\folder_B\file_B.proto

The script fails with error Exception: Could not find enum type folder_A_my_enum while generating default values for folder_B_dummy.

But if I remove the file_A.options, it works correctly. Also if I replace the enum by a message, it works correctly even with file_A.options.

My question is : do you know if it is possible to use the option * mangle_names:M_STRIP_PACKAGE and import enum at the same time ?

I use nanopb-0.4.5.

Thank you !

Answer 1

Currently M_STRIP_PACKAGE does not work when there are imports from another package. I have added the problem to the issue tracker: https://github.com/nanopb/nanopb/issues/783

Imports with name mangling seem to work fine, as long as all imported files belong to the same package and have same name mangling settings.

It is also questionable whether stripping the package name from types is a good idea when you are using multiple package names. It sounds like a recipe for name collisions.