blob: 6eac2e54e2957142aa0c46cc9a58c6b6e0a5a622 [file] [log] [blame]
# Copyright (c) 2023, 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
"""lua_proto_library(): a rule for building Lua protos."""
load("@bazel_skylib//lib:paths.bzl", "paths")
# 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 and ctx.rule.attr.strip_import_prefix and ctx.rule.attr.strip_import_prefix != "/":
package = package[len(ctx.rule.attr.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
# upb_proto_library / upb_proto_reflection_library shared code #################
_LuaFilesInfo = provider(
"A set of lua files generated from .proto files",
fields = ["files"],
)
def _compile_upb_protos(ctx, proto_info, proto_sources):
files = [_generate_output_file(ctx, name, "_pb.lua") 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],
),
tools = [ctx.executable._upbc],
outputs = files,
executable = ctx.executable._protoc,
arguments = [
"--lua_out=" + _get_real_root(ctx, files[0]),
"--plugin=protoc-gen-lua=" + ctx.executable._upbc.path,
"--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 Lua protos for :" + ctx.label.name,
)
return files
def _lua_proto_rule_impl(ctx):
if len(ctx.attr.deps) != 1:
fail("only one deps dependency allowed.")
dep = ctx.attr.deps[0]
if _LuaFilesInfo not in dep:
fail("proto_library rule must generate _LuaFilesInfo (aspect should have handled this).")
files = dep[_LuaFilesInfo].files
return [
DefaultInfo(
files = files,
data_runfiles = ctx.runfiles(files = files.to_list()),
),
]
def _lua_proto_library_aspect_impl(target, ctx):
proto_info = target[ProtoInfo]
files = _compile_upb_protos(ctx, proto_info, proto_info.direct_sources)
deps = ctx.rule.attr.deps
transitive = [dep[_LuaFilesInfo].files for dep in deps if _LuaFilesInfo in dep]
return [_LuaFilesInfo(files = depset(direct = files, transitive = transitive))]
# lua_proto_library() ##########################################################
_lua_proto_library_aspect = aspect(
attrs = {
"_upbc": attr.label(
executable = True,
cfg = "exec",
default = "//lua:protoc-gen-lua",
),
"_protoc": attr.label(
executable = True,
cfg = "exec",
default = "//:protoc",
),
},
implementation = _lua_proto_library_aspect_impl,
provides = [_LuaFilesInfo],
attr_aspects = ["deps"],
fragments = ["cpp"],
)
lua_proto_library = rule(
implementation = _lua_proto_rule_impl,
attrs = {
"deps": attr.label_list(
aspects = [_lua_proto_library_aspect],
allow_rules = ["proto_library"],
providers = [ProtoInfo],
),
},
)