Protobuf: Same name for rpc and message cause name conflict

[orian]

I think it's not mentioned in ProtoBuf guide (https://developers.google.com/protocol-buffers/docs/proto3#packages-and-name-resolution)

Proto definition:

message Version {
  string version = 1;
}

service Config {
  rpc Version(google.protobuf.Empty) returns (Version) {}
}

Error:

services.proto:97:49: "Version" is not a message type.

[jtattermusch]

Perhaps we could update the docs?

[liujisi]

The package and name resolution talks mostly about how to implicitly look up types in namespaces.

The case you raised are actually quite common, and I don't think we have a full list of cases where symbol names may conflict. Given the error message is already self-explanatory, I don't think adding a partial conflicting list would add too much value, as users would probably try define the same name and will immediately get the compile error.

[orian]

The self-explanatory message would be:
rpc "Version" name collides with message Message in line N.

The current message, for me caused a bit of mind fuck, checking if i'm compiling the correct .proto and so on.