Protobuf-C rules for Bazel

The C source code comes from protobuf-c

Getting Started

MODULE.bazel

bazel_dep(name = "rules_c_proto")
git_override(
    module_name="rules_c_proto",
    remote="https://github.com/JalonWong/rules_c_proto.git",
    branch="main",
)

BUILD

load("@rules_c_proto//:base.bzl", "c_proto_library")

proto_library(
    name = "msg_proto",
    srcs = ["msg.proto"],
)
c_proto_library(
    name = "msg_c_proto",
    deps = [":msg_proto"],
)
cc_binary(
    name = "app",
    deps = [":msg_c_proto"],
)

Build Options

If you don't want to use the heap in the std lib with your source code, for example embedded software, use the following.

build --define=protobuf_c_no_std=true

It will download protoc and protoc-gen-c by default. If you want to use your pre-installed binary, add the following to your .bazelrc. You can also use it in the command line. But this may cause version incompatibility issues.

build --define=c_proto_env_protoc=true

Proto Options

If you want to use the options in the protobuf-c.proto, add following to your MODULE.bazel

...

get_protobuf_c = use_extension("@rules_c_proto//:extensions.bzl", "get_protobuf_c")
use_repo(get_protobuf_c, "protobuf_c")
bazel_dep(name = "protobuf", version = "31.1")

Add following to your msg.proto

import "protobuf-c/protobuf-c.proto";

// depends on your need
option (pb_c_file).const_strings = true;
option (pb_c_file).use_oneof_field_name = true;

BUILD

proto_library(
    name = "msg_proto",
    srcs = ["msg.proto"],
    deps = ["@protobuf_c//:protobuf-c_proto"], # add this line
)