Back to Doc.qt.io
Contact Us Blog Download Qt

protobuf.cpp

Provides support for protocol buffers for the C++ language. More...

Since: Qbs 1.13

Properties

Detailed Description

The protobuf.cpp module provides support for generating C++ headers and sources from proto definition files using the protoc tool.

A simple qbs file that uses protobuf can be written as follows:

CppApplication {
    Depends { name: "protobuf.cpp" }
    files: ["foo.proto", "main.cpp"]
}

A generated header now can be included in the C++ sources:

#include <foo.pb.h>

int main(int argc, char* argv[]) {
    Foo bar;
    bar.set_answer(42);
    google::protobuf::ShutdownProtobufLibrary();
    return 0;
}

Relevant File Tags

TagAuto-tagged File NamesSinceDescription
"protobuf.input"*.proto1.13.0Source files with this tag are considered inputs to the protoc compiler.
"protobuf.grpc"1.14.0Source files with this tag are considered as gRPC files.
"protobuf.hpp"1.18.0This tag is attached to the header files generated by protoc compiler.

Dependencies

The protobuf.cpp module requires runtime libraries to be operational. It depends on the "protobuflib" module which can be created by the qbspkgconfig or fallback module providers (the corresponding packages are protobuf or protobuf-lite). If useGrpc is set to true, the protobuf.cpp module also depends on the "grpc++" module.

Property Documentation

[since Qbs 1.17] compilerName : string

The name of the protoc binary.

Default: "protoc"

This property was introduced in Qbs 1.17.


[since Qbs 1.17] compilerPath : string

The path to the protoc binary.

Use this property to override the auto-detected location.

Default: auto-detected

This property was introduced in Qbs 1.17.


importPaths : pathList

The list of imports that are passed to the protoc tool via the --proto_path option. These imports should contain the proto files. They are used to determine the relative structure of the generated files.

Note: The paths are passed to protoc in the same order as specified in this property and protoc output may differ depending on that order.

Default: []


[read-only] outputDir : string

The directory where the protoc compiler generated files are placed.

The value of this property is automatically set by Qbs and cannot be changed by the user.


useGrpc : bool

Whether to use gRPC framework.

Use this property to enable support for the modern open source high performance RPC framework by Google, gRPC (https://www.grpc.io).

A simple qbs file that uses grpc can be written as follows:

CppApplication {
    Depends { name: "protobuf.cpp" }
    protobuf.cpp.useGrpc: true
    files: ["main.cpp"]
    Group {
        files: "grpc.proto"
        fileTags: "protobuf.grpc"
    }
}

Note: that protobuf.grpc tag should be assigned manually because gRPC uses same *.proto files and Qbs can't detect whether to generate gRPC or protobuf.

The following grpc.proto file...

syntax = "proto3";

package Qbs;

message Request {
    string name = 1;
}

message Response {
    string name = 1;
}

service Grpc {
    rpc doWork(Request) returns (Response) {}
}

...can be used in the C++ sources as follows:

#include <grpc.grpc.pb.h>

class Service final : public Qbs::Grpc::Service
{
    grpc::Status doWork(
            grpc::ServerContext* context,
            const Qbs::Request* request,
            Qbs::Response* reply) override
    {
        (void)context;
        reply->set_name(request->name());
        return grpc::Status::OK;
    }
};

Default: false


© 2022 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.