Qbs Manual

Qbs 1.14.0

# protobuf.cpp

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

Since: | Qbs 1.13

- List of all members, including inherited members

## Properties

- grpcIncludePath : string
- grpcLibraryPath : string
- importPaths : pathList
- includePath : string
- libraryPath : string
- protocBinary : string
- useGrpc : bool

## 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

Tag | Auto-tagged File Names | Since | Description
--- | --- | --- | ---
`"protobuf.input"` | `*.proto` | 1.13.0 | Source files with this tag are considered inputs to the `protoc` compiler.
`"protobuf.grpc"` |  | 1.14.0 | Source files with this tag are considered as gRPC files.

## Property Documentation

grpcIncludePath : string

The path where grpc++ headers are located. Set this property to override the default location.

Default: `auto-detected`

grpcLibraryPath : string

The path where the grpc++ library is located. Set this property to override the default location.

Default: `auto-detected`

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: `[]`

includePath : string

The path where protobuf C++ headers are located. Set this property to override the default location.

Default: `auto-detected`

libraryPath : string

The path where the protobuf C++ library is located. Set this property to override the default location.

Default: `auto-detected`

protocBinary : string

The command to invoke when compiling proto definition files.

Default: `auto-detected`

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`