| """This file implements an experimental, do-not-use-kind of rust_proto_library. |
| |
| Disclaimer: This project is experimental, under heavy development, and should not |
| be used yet.""" |
| |
| load("@rules_rust//rust:defs.bzl", "rust_common") |
| load("//bazel/common:proto_common.bzl", "proto_common") |
| load("//bazel/common:proto_info.bzl", "ProtoInfo") |
| load( |
| "//rust:aspects.bzl", |
| "RustProtoInfo", |
| "label_to_crate_name", |
| "proto_rust_toolchain_label", |
| "rust_cc_proto_library_aspect", |
| "rust_upb_proto_library_aspect", |
| ) |
| |
| visibility([ |
| "//experimental/...", |
| "//src/google/protobuf/...", |
| "//rust/...", |
| ]) |
| |
| def rust_proto_library(name, deps, **args): |
| """Declares all the boilerplate needed to use Rust protobufs conveniently. |
| |
| Hopefully no user will ever need to read this code. |
| |
| |
| Args: |
| name: name of the Rust protobuf target. |
| deps: proto_library target for which to generate Rust gencode. |
| **args: other args passed to the rust_<kernel>_proto_library targets. |
| """ |
| if not name.endswith("_rust_proto"): |
| fail( |
| "{}: Name rust_proto_library target should end with `_rust_proto`, but was '{}'" |
| .format(name), |
| ) |
| name = name.removesuffix("_rust_proto") |
| alias_args = {} |
| if "visibility" in args: |
| alias_args["visibility"] = args.pop("visibility") |
| native.alias( |
| name = name + "_rust_proto", |
| actual = select({ |
| "//rust:use_upb_kernel": name + "_upb_rust_proto", |
| "//conditions:default": name + "_cpp_rust_proto", |
| }), |
| **alias_args |
| ) |
| |
| rust_upb_proto_library( |
| name = name + "_upb_rust_proto", |
| deps = deps, |
| visibility = ["//visibility:private"], |
| **args |
| ) |
| |
| rust_cc_proto_library( |
| name = name + "_cpp_rust_proto", |
| deps = deps, |
| visibility = ["//visibility:private"], |
| **args |
| ) |
| |
| def _user_visible_label(ctx): |
| label = str(ctx.label) |
| label = label.removesuffix("_cpp_rust_proto") |
| label = label.removesuffix("_upb_rust_proto") |
| return label + "_rust_proto" |
| |
| def _rust_proto_library_impl(ctx): |
| if not ctx.label.name.endswith("_rust_proto"): |
| fail( |
| "{}: Name of rust_proto_library target should end with `_rust_proto`." |
| .format(_user_visible_label(ctx)), |
| ) |
| deps = ctx.attr.deps |
| if not deps: |
| fail( |
| "{}: Exactly 1 dependency in `deps` attribute expected, none were provided." |
| .format(_user_visible_label(ctx)), |
| ) |
| if len(deps) > 1: |
| fail( |
| "{}: Exactly 1 dependency in `deps` attribute expected, too many were provided." |
| .format(_user_visible_label(ctx)), |
| ) |
| |
| dep = deps[0] |
| rust_proto_info = dep[RustProtoInfo] |
| |
| dep_variant_info = rust_proto_info.dep_variant_info |
| crate_info = dep_variant_info.crate_info |
| |
| # Change the crate name from the hame of the proto_library to the name of the rust_proto_library. |
| # |
| # When the aspect visits proto_libraries, it doesn't know and cannot deduce the name of the |
| # rust_proto_library (although the name of rust_proto_libraries is consistently ending with |
| # _rust_proto, we can't rely on all proto_libraires to have a name consistently ending with |
| # _proto), therefore we have to modify it after the fact here. |
| # |
| # Since Starlark providers are frozen once they leave the _impl function that defines them, |
| # we have to create a shallow copy. |
| toolchain = ctx.toolchains["@rules_rust//rust:toolchain_type"] |
| fields = {field: getattr(crate_info, field) for field in dir(crate_info)} |
| pkg, name = _user_visible_label(ctx).rsplit(":") |
| label = struct(**{"name": name, "pkg": pkg}) |
| fields["name"] = label_to_crate_name(ctx, label, toolchain) |
| crate_info_with_rust_proto_name = rust_common.crate_info(**fields) |
| |
| return [ |
| crate_info_with_rust_proto_name, |
| dep_variant_info.dep_info, |
| dep_variant_info.cc_info, |
| DefaultInfo(files = dep_variant_info.crate_info.srcs), |
| ] |
| |
| def _make_rust_proto_library(is_upb): |
| return rule( |
| implementation = _rust_proto_library_impl, |
| attrs = { |
| "deps": attr.label_list( |
| mandatory = True, |
| providers = [ProtoInfo], |
| aspects = [rust_upb_proto_library_aspect if is_upb else rust_cc_proto_library_aspect], |
| ), |
| "_proto_lang_toolchain": attr.label( |
| default = Label(proto_rust_toolchain_label(is_upb)), |
| ), |
| }, |
| toolchains = [ |
| "@rules_rust//rust:toolchain_type", |
| ], |
| ) |
| |
| rust_upb_proto_library = _make_rust_proto_library(is_upb = True) |
| rust_cc_proto_library = _make_rust_proto_library(is_upb = False) |