With this fix, Unity using IL2CPP should work with one of two
approaches:
- Call `FileDescriptor.ForceReflectionInitialization<T>` for every
enum present in generated code (including oneof case enums)
- Ensure that IL2CPP uses the same code for int and any int-based
enums
The former approach is likely to be simpler, unless IL2CPP changes
its default behavior. We *could* potentially generate the code
automatically, but that makes me slightly uncomfortable in terms of
generating code that's only relevant in one specific scenario. It
would be reasonably easy to write a tool (separate from protoc) to
generate the code required for any specific set of assemblies, so
that Unity users can include it in their application. We can always
decide to change to generate it automatically later.
The SampleEnumMethod method was previously only called via
reflection, so the Unity linker thought it could be removed. Ditto
the parameterless constructor in ReflectionHelper.
This PR should avoid that issue, reducing the work needed by
customers to use Google.Protobuf from Unity.
For oneofs, to get the case, we need to call the property that
returns the enum value. We really want it as an int, and modern
runtimes allow us to create a delegate which returns an int from the
method. (I suspect that the MS runtime has always allowed that.)
Old versions of Mono (e.g. used by Unity3d) don't allow that, so we
have to convert the enum value to an int via boxing. It's ugly, but
it should work.
This should work on Unity, Mono and .NET 3.5 as far as I'm aware.
It won't work on platforms where reflection itself is prohibited,
but that's a non-starter basically.
This will allow SourceLink as per #4179, and mean that we can use C#
7.0 language features in the library (but not in generated code).
This does not affect which platforms we're *targeting*, so end users
won't see any difference.
It would be nice to update to 2.1.4, but AppVeyor's "Visual Studio
2017" environment is only 2.0.3.
By default, unknown fields are preserved when parsing. To discard
them, use a parser configured to do so:
var parser = MyMessage.Parser.WithDiscardUnknownFields(true);
unittest_proto3 had been changed in a very backward-incompatible
way which was never going to work with C# as it imports proto2 messages.
This is now a copy of the old file, but with a package name change for
compatibility with the remaining files in src/google/protobuf.
The other moves are for files that are only used by C#.
If messages A and B have the same oneof case, which is a message
type, and we merge B into A, those sub-messages should be merged.
Fixes#3200.
Note that I haven't regenerated all the code, as some of the protos
have been changed, breaking generation.
