| # Copyright (c) 2009-2021, Google LLC |
| # All rights reserved. |
| # |
| # Use of this source code is governed by a BSD-style |
| # license that can be found in the LICENSE file or at |
| # https://developers.google.com/open-source/licenses/bsd |
| |
| """An implementation of py_proto_library(). |
| |
| We have to implement this ourselves because there is currently no reasonable |
| py_proto_library() rule available for Bazel. |
| |
| Our py_proto_library() is similar to how a real py_proto_library() should work. |
| But it hasn't been deeply tested or reviewed, and upb should not be in the |
| business of vending py_proto_library(), so we keep it private to upb. |
| """ |
| |
| load("@bazel_skylib//lib:paths.bzl", "paths") |
| load("@rules_python//python:py_info.bzl", "PyInfo") |
| load("//bazel/common:proto_info.bzl", "ProtoInfo") |
| |
| # 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 |
| |
| # py_proto_library() ########################################################### |
| |
| def _py_proto_library_rule_impl(ctx): |
| # A real py_proto_library() should enforce this constraint. |
| # We don't bother for now, since it saves us some effort not to. |
| # |
| # if len(ctx.attr.deps) != 1: |
| # fail("only one deps dependency allowed.") |
| |
| files = [] |
| for dep in ctx.attr.deps: |
| files += dep[PyInfo].transitive_sources.to_list() |
| return [ |
| DefaultInfo(files = depset(direct = files)), |
| ] |
| |
| def _py_proto_library_aspect_impl(target, ctx): |
| proto_info = target[ProtoInfo] |
| proto_sources = proto_info.direct_sources |
| srcs = [_generate_output_file(ctx, name, "_pb2.py") for name in proto_sources] |
| transitive_sets = proto_info.transitive_descriptor_sets.to_list() |
| ctx.actions.run( |
| inputs = depset( |
| direct = [proto_info.direct_descriptor_set], |
| transitive = [proto_info.transitive_descriptor_sets], |
| ), |
| outputs = srcs, |
| executable = ctx.executable._protoc, |
| arguments = [ |
| "--python_out=" + _get_real_root(ctx, srcs[0]), |
| "--descriptor_set_in=" + ctx.configuration.host_path_separator.join([f.path for f in transitive_sets]), |
| ] + |
| [_get_real_short_path(file) for file in proto_sources], |
| progress_message = "Generating Python protos for :" + ctx.label.name, |
| ) |
| outs_depset = depset(srcs) |
| return [ |
| PyInfo(transitive_sources = outs_depset), |
| ] |
| |
| _py_proto_library_aspect = aspect( |
| attrs = { |
| "_protoc": attr.label( |
| executable = True, |
| cfg = "exec", |
| default = "//:protoc", |
| ), |
| }, |
| implementation = _py_proto_library_aspect_impl, |
| provides = [ |
| PyInfo, |
| ], |
| attr_aspects = ["deps"], |
| ) |
| |
| py_proto_library = rule( |
| implementation = _py_proto_library_rule_impl, |
| attrs = { |
| "deps": attr.label_list( |
| aspects = [_py_proto_library_aspect], |
| allow_rules = ["proto_library"], |
| providers = [ProtoInfo], |
| ), |
| }, |
| ) |