"""Public rules for using cc proto descriptor library with protos: - cc_proto_descriptor_library() """ load("@bazel_skylib//lib:paths.bzl", "paths") # begin:google_only # load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain", "use_cpp_toolchain") # end:google_only # begin:github_only # Compatibility code for Bazel 4.x. Remove this when we drop support for Bazel 4.x. load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain") def use_cpp_toolchain(): return ["@bazel_tools//tools/cpp:toolchain_type"] # end:github_only # Generic support code ######################################################### # begin:github_only _is_google3 = False # end:github_only # begin:google_only # _is_google3 = True # end:google_only def _get_real_short_path(file): # For some reason, files from other archives have short paths that look like: # ../com_google_protobuf/google/protobuf/descriptor.proto short_path = file.short_path if short_path.startswith("../"): second_slash = short_path.index("/", 3) short_path = short_path[second_slash + 1:] # Sometimes it has another few prefixes like: # _virtual_imports/any_proto/google/protobuf/any.proto # benchmarks/_virtual_imports/100_msgs_proto/benchmarks/100_msgs.proto # We want just google/protobuf/any.proto. virtual_imports = "_virtual_imports/" if virtual_imports in short_path: short_path = short_path.split(virtual_imports)[1].split("/", 1)[1] return short_path def _get_real_root(ctx, file): real_short_path = _get_real_short_path(file) root = file.path[:-len(real_short_path) - 1] if not _is_google3 and ctx.rule.attr.strip_import_prefix: root = paths.join(root, ctx.rule.attr.strip_import_prefix[1:]) return root def _generate_output_file(ctx, src, extension): package = ctx.label.package if not _is_google3: strip_import_prefix = ctx.rule.attr.strip_import_prefix if strip_import_prefix and strip_import_prefix != "/": if not package.startswith(strip_import_prefix[1:]): fail("%s does not begin with prefix %s" % (package, strip_import_prefix)) package = package[len(strip_import_prefix):] real_short_path = _get_real_short_path(src) real_short_path = paths.relativize(real_short_path, package) output_filename = paths.replace_extension(real_short_path, extension) ret = ctx.actions.declare_file(output_filename) return ret def _generate_include_path(src, out, extension): short_path = _get_real_short_path(src) short_path = paths.replace_extension(short_path, extension) if not out.path.endswith(short_path): fail("%s does not end with %s" % (out.path, short_path)) return out.path[:-len(short_path)] def _filter_none(elems): out = [] for elem in elems: if elem: out.append(elem) return out def _cc_library_func(ctx, name, hdrs, srcs, copts, includes, dep_ccinfos): """Like cc_library(), but callable from rules. Args: ctx: Rule context. name: Unique name used to generate output files. hdrs: Public headers that can be #included from other rules. srcs: C/C++ source files. copts: Additional options for cc compilation. includes: Additional include paths. dep_ccinfos: CcInfo providers of dependencies we should build/link against. Returns: CcInfo provider for this compilation. """ compilation_contexts = [info.compilation_context for info in dep_ccinfos] linking_contexts = [info.linking_context for info in dep_ccinfos] toolchain = find_cpp_toolchain(ctx) feature_configuration = cc_common.configure_features( ctx = ctx, cc_toolchain = toolchain, requested_features = ctx.features, unsupported_features = ctx.disabled_features, ) blaze_only_args = {} if _is_google3: blaze_only_args["grep_includes"] = ctx.file._grep_includes (compilation_context, compilation_outputs) = cc_common.compile( actions = ctx.actions, feature_configuration = feature_configuration, cc_toolchain = toolchain, name = name, srcs = srcs, includes = includes, public_hdrs = hdrs, user_compile_flags = copts, compilation_contexts = compilation_contexts, **blaze_only_args ) # buildifier: disable=unused-variable (linking_context, linking_outputs) = cc_common.create_linking_context_from_compilation_outputs( actions = ctx.actions, name = name, feature_configuration = feature_configuration, cc_toolchain = toolchain, compilation_outputs = compilation_outputs, linking_contexts = linking_contexts, disallow_dynamic_library = cc_common.is_enabled(feature_configuration = feature_configuration, feature_name = "targets_windows"), **blaze_only_args ) return CcInfo( compilation_context = compilation_context, linking_context = linking_context, ) # Dummy rule to expose select() copts to aspects ############################## CcProtoDescriptorLibraryCoptsInfo = provider( "Provides copts for cc proto descriptor library targets", fields = { "copts": "copts for cc_proto_descriptor_library()", }, ) def cc_proto_descriptor_library_copts_impl(ctx): return CcProtoDescriptorLibraryCoptsInfo(copts = ctx.attr.copts) cc_proto_descriptor_library_copts = rule( implementation = cc_proto_descriptor_library_copts_impl, attrs = {"copts": attr.string_list(default = [])}, ) # cc_proto_descriptor_library shared code ################# GeneratedSrcsInfo = provider( "Provides generated headers and sources", fields = { "srcs": "list of srcs", "hdrs": "list of hdrs", "includes": "list of extra includes", }, ) CcProtoDescriptorWrappedCcInfo = provider("Provider for cc_info for protos", fields = ["cc_info"]) _CcProtoDescriptorWrappedGeneratedSrcsInfo = provider("Provider for generated sources", fields = ["srcs"]) def _compile_protos(ctx, generator, proto_info, proto_sources): if len(proto_sources) == 0: return GeneratedSrcsInfo(srcs = [], hdrs = [], includes = []) ext = "_" + generator tool = getattr(ctx.executable, "_gen_" + generator) srcs = [_generate_output_file(ctx, name, ext + ".pb.cc") for name in proto_sources] hdrs = [_generate_output_file(ctx, name, ext + ".pb.h") for name in proto_sources] transitive_sets = proto_info.transitive_descriptor_sets.to_list() args = ctx.actions.args() args.use_param_file(param_file_arg = "@%s") args.set_param_file_format("multiline") args.add("--" + generator + "_out=" + _get_real_root(ctx, srcs[0])) args.add("--plugin=protoc-gen-" + generator + "=" + tool.path) args.add("--descriptor_set_in=" + ctx.configuration.host_path_separator.join([f.path for f in transitive_sets])) args.add_all(proto_sources, map_each = _get_real_short_path) ctx.actions.run( inputs = depset( direct = [proto_info.direct_descriptor_set], transitive = [proto_info.transitive_descriptor_sets], ), tools = [tool], outputs = srcs + hdrs, executable = ctx.executable._protoc, arguments = [args], progress_message = "Generating descriptor protos for :" + ctx.label.name, mnemonic = "GenDescriptorProtos", ) return GeneratedSrcsInfo( srcs = srcs, hdrs = hdrs, includes = [_generate_include_path(proto_sources[0], hdrs[0], "_descriptor.pb.h")], ) def _cc_proto_descriptor_rule_impl(ctx): if len(ctx.attr.deps) != 1: fail("only one deps dependency allowed.") dep = ctx.attr.deps[0] if _CcProtoDescriptorWrappedGeneratedSrcsInfo in dep: srcs = dep[_CcProtoDescriptorWrappedGeneratedSrcsInfo].srcs else: fail("proto_library rule must generate _CcProtoDescriptorWrappedGeneratedSrcsInfo " + "(aspect should have handled this).") if CcProtoDescriptorWrappedCcInfo in dep: cc_info = dep[CcProtoDescriptorWrappedCcInfo].cc_info else: fail("proto_library rule must generate CcProtoDescriptorWrappedCcInfo " + "(aspect should have handled this).") lib = cc_info.linking_context.linker_inputs.to_list()[0].libraries[0] files = _filter_none([ lib.static_library, lib.pic_static_library, lib.dynamic_library, ]) return [ DefaultInfo(files = depset(files + srcs.hdrs + srcs.srcs)), srcs, cc_info, ] def _cc_proto_descriptor_aspect_impl(target, ctx, generator, cc_provider, file_provider, provide_cc_shared_library_hints = True): proto_info = target[ProtoInfo] files = _compile_protos(ctx, generator, proto_info, proto_info.direct_sources) deps = ctx.rule.attr.deps + getattr(ctx.attr, "_" + generator) dep_ccinfos = [dep[CcInfo] for dep in deps if CcInfo in dep] dep_ccinfos += [dep[CcProtoDescriptorWrappedCcInfo].cc_info for dep in deps if CcProtoDescriptorWrappedCcInfo in dep] name = ctx.rule.attr.name + "." + generator owners = [ctx.label.relative(name)] cc_info = _cc_library_func( ctx = ctx, name = name, hdrs = files.hdrs, srcs = files.srcs, includes = files.includes, #copts = ctx.attr._copts[CcProtoDescriptorLibraryCoptsInfo].copts, copts = [], dep_ccinfos = dep_ccinfos, ) wrapped_cc_info = cc_provider( cc_info = cc_info, ) providers = [ wrapped_cc_info, file_provider(srcs = files), ] if provide_cc_shared_library_hints: if hasattr(cc_common, "CcSharedLibraryHintInfo"): providers.append(cc_common.CcSharedLibraryHintInfo(owners = owners)) elif hasattr(cc_common, "CcSharedLibraryHintInfo_6_X_constructor_do_not_use"): # This branch can be deleted once 6.X is not supported by rules providers.append(cc_common.CcSharedLibraryHintInfo_6_X_constructor_do_not_use(owners = owners)) return providers def cc_proto_descriptor_library_aspect_impl(target, ctx): return _cc_proto_descriptor_aspect_impl(target, ctx, "descriptor", CcProtoDescriptorWrappedCcInfo, _CcProtoDescriptorWrappedGeneratedSrcsInfo) def _maybe_add(d): if _is_google3: d["_grep_includes"] = attr.label( allow_single_file = True, cfg = "exec", default = "@bazel_tools//tools/cpp:grep-includes", ) return d # cc_proto_descriptor_library() ########################################################## def _get_cc_proto_descriptor_library_aspect_provides(): provides = [ CcProtoDescriptorWrappedCcInfo, _CcProtoDescriptorWrappedGeneratedSrcsInfo, ] if hasattr(cc_common, "CcSharedLibraryHintInfo"): provides.append(cc_common.CcSharedLibraryHintInfo) elif hasattr(cc_common, "CcSharedLibraryHintInfo_6_X_getter_do_not_use"): # This branch can be deleted once 6.X is not supported by upb rules provides.append(cc_common.CcSharedLibraryHintInfo_6_X_getter_do_not_use) return provides cc_proto_descriptor_library_aspect = aspect( attrs = _maybe_add({ "_gen_descriptor": attr.label( executable = True, cfg = "exec", default = "//bazel/cc_proto_descriptor_library:file_descriptor_generator", ), "_protoc": attr.label( executable = True, cfg = "exec", default = "@com_google_protobuf//:protoc", ), "_cc_toolchain": attr.label( default = "@bazel_tools//tools/cpp:current_cc_toolchain", ), "_descriptor": attr.label_list( default = [ Label("//bazel/cc_proto_descriptor_library:file_descriptor_info"), Label("@com_google_absl//absl/base:core_headers"), ], ), }), implementation = cc_proto_descriptor_library_aspect_impl, provides = _get_cc_proto_descriptor_library_aspect_provides(), attr_aspects = ["deps"], fragments = ["cpp"], toolchains = use_cpp_toolchain(), ) cc_proto_descriptor_library = rule( implementation = _cc_proto_descriptor_rule_impl, attrs = { "deps": attr.label_list( aspects = [cc_proto_descriptor_library_aspect], allow_rules = ["proto_library"], providers = [ProtoInfo], ), }, provides = [CcInfo], )