support embedding message

[unlikezy]

My request might be similar to #192
Given the proto definition:

synatx = "proto3";
package test;
message Req1 {
    string user_id = 1;
    uint64 timestamp = 2;
    uint64 region_id = 3;
     string req1_fff1 = 10;
     string req1_fff2 = 11;
}
message Req2 {
    string user_id = 1;
    uint64 timestamp = 2;
    uint64 region_id = 3;
     string req2_fff1 = 10;
     string req2_fff2 = 11;
}
// more reqs definition....

As you can see, every Req definition needs some common fileds(1~3).
I have to repeate them(might be a lot) in every message.
You might suggest to seperate these fields into a new message, like this:

message CommonFields {
    string user_id = 1;
    uint64 timestamp = 2;
    uint64 region_id = 3;
}
message Req1 {
     CommonFields common_fields = 1;
     string req1_fff1 = 10;
     string req1_fff2 = 11;
}
message Req2 {
     CommonFields common_fields = 1;
     string req2_fff1 = 10;
     string req2_fff2 = 11;
}

But we are using grpcgateway, and the json proto is required by our company MUST be the former way:
(there might be a lot other reasons for people need proto be in this way)

message Req1 {
    string user_id = 1;
    uint64 timestamp = 2;
    uint64 region_id = 3;
     string req1_fff1 = 10;
     string req1_fff2 = 11;
}

The problem will be well solved if protobuf provide a syntax suger like this:

message Req1 {
      CommonFields;
     string req1_fff1 = 10;
     string req1_fff2 = 11;
}

what protoc should do is to treat this definition as below:

message Req1 {
    string user_id = 1;
    uint64 timestamp = 2;
    uint64 region_id = 3;
     string req1_fff1 = 10;
     string req1_fff2 = 11;
}

This solution seems quite straightforward.

[unlikezy]

it might be better to put this request on https://github.com/protocolbuffers/protobuf
and I did do it : protocolbuffers/protobuf#5372
but I still keep this issue here.

[neild]

Yes, this request is best filed against https://github.com/protocolbuffers/protobuf. Closing this one as a duplicate.