| """Utility functions for generating protobuf code.""" |
| |
| _PROTO_EXTENSION = ".proto" |
| _VIRTUAL_IMPORTS = "/_virtual_imports/" |
| |
| def get_proto_root(workspace_root): |
| """Gets the root protobuf directory. |
| |
| Args: |
| workspace_root: context.label.workspace_root |
| |
| Returns: |
| The directory relative to which generated include paths should be. |
| """ |
| if workspace_root: |
| return "/{}".format(workspace_root) |
| else: |
| return "" |
| |
| def _strip_proto_extension(proto_filename): |
| if not proto_filename.endswith(_PROTO_EXTENSION): |
| fail('"{}" does not end with "{}"'.format( |
| proto_filename, |
| _PROTO_EXTENSION, |
| )) |
| return proto_filename[:-len(_PROTO_EXTENSION)] |
| |
| def proto_path_to_generated_filename(proto_path, fmt_str): |
| """Calculates the name of a generated file for a protobuf path. |
| |
| For example, "examples/protos/helloworld.proto" might map to |
| "helloworld.pb.h". |
| |
| Args: |
| proto_path: The path to the .proto file. |
| fmt_str: A format string used to calculate the generated filename. For |
| example, "{}.pb.h" might be used to calculate a C++ header filename. |
| |
| Returns: |
| The generated filename. |
| """ |
| return fmt_str.format(_strip_proto_extension(proto_path)) |
| |
| def get_include_directory(source_file): |
| """Returns the include directory path for the source_file. I.e. all of the |
| include statements within the given source_file are calculated relative to |
| the directory returned by this method. |
| |
| The returned directory path can be used as the "--proto_path=" argument |
| value. |
| |
| Args: |
| source_file: A proto file. |
| |
| Returns: |
| The include directory path for the source_file. |
| """ |
| directory = source_file.path |
| prefix_len = 0 |
| |
| if is_in_virtual_imports(source_file): |
| root, relative = source_file.path.split(_VIRTUAL_IMPORTS, 2) |
| result = root + _VIRTUAL_IMPORTS + relative.split("/", 1)[0] |
| return result |
| |
| if not source_file.is_source and directory.startswith(source_file.root.path): |
| prefix_len = len(source_file.root.path) + 1 |
| |
| if directory.startswith("external", prefix_len): |
| external_separator = directory.find("/", prefix_len) |
| repository_separator = directory.find("/", external_separator + 1) |
| return directory[:repository_separator] |
| else: |
| return source_file.root.path if source_file.root.path else "." |
| |
| def get_plugin_args( |
| plugin, |
| flags, |
| dir_out, |
| generate_mocks, |
| plugin_name = "PLUGIN"): |
| """Returns arguments configuring protoc to use a plugin for a language. |
| |
| Args: |
| plugin: An executable file to run as the protoc plugin. |
| flags: The plugin flags to be passed to protoc. |
| dir_out: The output directory for the plugin. |
| generate_mocks: A bool indicating whether to generate mocks. |
| plugin_name: A name of the plugin, it is required to be unique when there |
| are more than one plugin used in a single protoc command. |
| Returns: |
| A list of protoc arguments configuring the plugin. |
| """ |
| augmented_flags = list(flags) |
| if generate_mocks: |
| augmented_flags.append("generate_mock_code=true") |
| |
| augmented_dir_out = dir_out |
| if augmented_flags: |
| augmented_dir_out = ",".join(augmented_flags) + ":" + dir_out |
| |
| return [ |
| "--plugin=protoc-gen-{plugin_name}={plugin_path}".format( |
| plugin_name = plugin_name, |
| plugin_path = plugin.path, |
| ), |
| "--{plugin_name}_out={dir_out}".format( |
| plugin_name = plugin_name, |
| dir_out = augmented_dir_out, |
| ), |
| ] |
| |
| def _get_staged_proto_file(context, source_file): |
| if source_file.dirname == context.label.package or \ |
| is_in_virtual_imports(source_file): |
| # Current target and source_file are in same package |
| return source_file |
| else: |
| # Current target and source_file are in different packages (most |
| # probably even in different repositories) |
| copied_proto = context.actions.declare_file(source_file.basename) |
| context.actions.run_shell( |
| inputs = [source_file], |
| outputs = [copied_proto], |
| command = "cp {} {}".format(source_file.path, copied_proto.path), |
| mnemonic = "CopySourceProto", |
| ) |
| return copied_proto |
| |
| def protos_from_context(context): |
| """Copies proto files to the appropriate location. |
| |
| Args: |
| context: The ctx object for the rule. |
| |
| Returns: |
| A list of the protos. |
| """ |
| protos = [] |
| for src in context.attr.deps: |
| for file in src[ProtoInfo].direct_sources: |
| protos.append(_get_staged_proto_file(context, file)) |
| return protos |
| |
| def includes_from_deps(deps): |
| """Get includes from rule dependencies.""" |
| return [ |
| file |
| for src in deps |
| for file in src[ProtoInfo].transitive_imports.to_list() |
| ] |
| |
| def get_proto_arguments(protos, genfiles_dir_path): |
| """Get the protoc arguments specifying which protos to compile.""" |
| arguments = [] |
| for proto in protos: |
| strip_prefix_len = 0 |
| if is_in_virtual_imports(proto): |
| incl_directory = get_include_directory(proto) |
| if proto.path.startswith(incl_directory): |
| strip_prefix_len = len(incl_directory) + 1 |
| elif proto.path.startswith(genfiles_dir_path): |
| strip_prefix_len = len(genfiles_dir_path) + 1 |
| |
| arguments.append(proto.path[strip_prefix_len:]) |
| |
| return arguments |
| |
| def declare_out_files(protos, context, generated_file_format): |
| """Declares and returns the files to be generated.""" |
| |
| out_file_paths = [] |
| for proto in protos: |
| if not is_in_virtual_imports(proto): |
| out_file_paths.append(proto.basename) |
| else: |
| path = proto.path[proto.path.index(_VIRTUAL_IMPORTS) + 1:] |
| out_file_paths.append(path) |
| |
| return [ |
| context.actions.declare_file( |
| proto_path_to_generated_filename( |
| out_file_path, |
| generated_file_format, |
| ), |
| ) |
| for out_file_path in out_file_paths |
| ] |
| |
| def get_out_dir(protos, context): |
| """ Returns the calculated value for --<lang>_out= protoc argument based on |
| the input source proto files and current context. |
| |
| Args: |
| protos: A list of protos to be used as source files in protoc command |
| context: A ctx object for the rule. |
| Returns: |
| The value of --<lang>_out= argument. |
| """ |
| at_least_one_virtual = 0 |
| for proto in protos: |
| if is_in_virtual_imports(proto): |
| at_least_one_virtual = True |
| elif at_least_one_virtual: |
| fail("Proto sources must be either all virtual imports or all real") |
| if at_least_one_virtual: |
| out_dir = get_include_directory(protos[0]) |
| ws_root = protos[0].owner.workspace_root |
| if ws_root and out_dir.find(ws_root) >= 0: |
| out_dir = "".join(out_dir.rsplit(ws_root, 1)) |
| return struct( |
| path = out_dir, |
| import_path = out_dir[out_dir.find(_VIRTUAL_IMPORTS) + 1:], |
| ) |
| return struct(path = context.genfiles_dir.path, import_path = None) |
| |
| def is_in_virtual_imports(source_file, virtual_folder = _VIRTUAL_IMPORTS): |
| """Determines if source_file is virtual (is placed in _virtual_imports |
| subdirectory). The output of all proto_library targets which use |
| import_prefix and/or strip_import_prefix arguments is placed under |
| _virtual_imports directory. |
| |
| Args: |
| source_file: A proto file. |
| virtual_folder: The virtual folder name (is set to "_virtual_imports" |
| by default) |
| Returns: |
| True if source_file is located under _virtual_imports, False otherwise. |
| """ |
| return not source_file.is_source and virtual_folder in source_file.path |
