bazel-skylib/skylark_library.bzl

111 lines
2.9 KiB
Python

# 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):
all_files = depset(ctx.files.srcs, order="postorder")
for dep in ctx.attr.deps:
all_files += dep.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",
],
)
```
"""