| # Copyright 2017 The Bazel Authors. All rights reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """Skylib module containing a library rule for aggregating rules files.""" |
| |
| SkylarkLibraryInfo = provider( |
| "Information on contained Skylark rules.", |
| fields = { |
| "srcs": "Top level rules files.", |
| "transitive_srcs": "Transitive closure of rules files required for " + |
| "interpretation of the srcs", |
| }, |
| ) |
| |
| def _skylark_library_impl(ctx): |
| deps_files = [depset(x.files, order = "postorder") for x in ctx.attr.deps] |
| all_files = depset(ctx.files.srcs, order = "postorder", transitive = deps_files) |
| return [ |
| # All dependent files should be listed in both `files` and in `runfiles`; |
| # this ensures that a `skylark_library` can be referenced as `data` from |
| # a separate program, or from `tools` of a genrule(). |
| DefaultInfo( |
| files = all_files, |
| runfiles = ctx.runfiles(files = list(all_files)), |
| ), |
| |
| # We also define our own provider struct, for aggregation and testing. |
| SkylarkLibraryInfo( |
| srcs = ctx.files.srcs, |
| transitive_srcs = all_files, |
| ), |
| ] |
| |
| skylark_library = rule( |
| implementation = _skylark_library_impl, |
| attrs = { |
| "srcs": attr.label_list( |
| allow_files = [".bzl"], |
| ), |
| "deps": attr.label_list( |
| allow_files = [".bzl"], |
| providers = [ |
| [SkylarkLibraryInfo], |
| ], |
| ), |
| }, |
| ) |
| """Creates a logical collection of Skylark .bzl files. |
| |
| Args: |
| srcs: List of `.bzl` files that are processed to create this target. |
| deps: List of other `skylark_library` targets that are required by the |
| Skylark files listed in `srcs`. |
| |
| Example: |
| Suppose your project has the following structure: |
| |
| ``` |
| [workspace]/ |
| WORKSPACE |
| BUILD |
| checkstyle/ |
| BUILD |
| checkstyle.bzl |
| lua/ |
| BUILD |
| lua.bzl |
| luarocks.bzl |
| ``` |
| |
| In this case, you can have `skylark_library` targets in `checkstyle/BUILD` and |
| `lua/BUILD`: |
| |
| `checkstyle/BUILD`: |
| |
| ```python |
| load("@bazel_skylib//:skylark_library.bzl", "skylark_library") |
| |
| skylark_library( |
| name = "checkstyle-rules", |
| srcs = ["checkstyle.bzl"], |
| ) |
| ``` |
| |
| `lua/BUILD`: |
| |
| ```python |
| load("@bazel_skylib//:skylark_library.bzl", "skylark_library") |
| |
| skylark_library( |
| name = "lua-rules", |
| srcs = [ |
| "lua.bzl", |
| "luarocks.bzl", |
| ], |
| ) |
| ``` |
| """ |