xref: /aosp_15_r20/external/bazel-skylib/lib/subpackages.bzl (revision bcb5dc7965af6ee42bf2f21341a2ec00233a8c8a)
1# Copyright 2022 The Bazel Authors. All rights reserved.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#    http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Skylib module containing common functions for working with native.subpackages()
16"""
17_SUBPACKAGES_SUPPORTED = hasattr(native, "subpackages")
18
19def _supported():
20    return _SUBPACKAGES_SUPPORTED
21
22def _check_supported():
23    if not _SUBPACKAGES_SUPPORTED:
24        fail("native.subpackages not supported in this version of Bazel.")
25
26def _all(exclude = [], allow_empty = False, fully_qualified = True):
27    """List all direct subpackages of the current package regardless of directory depth.
28
29    The returned list contains all subpackages, but not subpackages of subpackages.
30
31    Example:
32    Assuming the following BUILD files exist:
33
34        BUILD
35        foo/BUILD
36        foo/sub/BUILD
37        bar/BUILD
38        baz/deep/dir/BUILD
39
40    If the current package is '//' all() will return ['//foo', '//bar',
41    '//baz/deep/dir'].  //foo/sub is not included because it is a direct
42    subpackage of '//foo' not '//'
43
44    NOTE: fail()s if native.subpackages() is not supported.
45
46    Args:
47      exclude:          see native.subpackages(exclude)
48      allow_empty:      see native.subpackages(allow_empty)
49      fully_qualified:  It true return fully qualified Labels for subpackages,
50          otherwise returns subpackage path relative to current package.
51
52    Returns:
53      A mutable sorted list containing all sub-packages of the current Bazel
54      package.
55    """
56    _check_supported()
57
58    subs = native.subpackages(include = ["**"], exclude = exclude, allow_empty = allow_empty)
59    if fully_qualified:
60        return [_fully_qualified(s) for s in subs]
61
62    return subs
63
64def _fully_qualified(relative_path):
65    return "//%s/%s" % (native.package_name(), relative_path)
66
67def _exists(relative_path):
68    """Checks to see if relative_path is a direct subpackage of the current package.
69
70    Example:
71
72        BUILD
73        foo/BUILD
74        foo/sub/BUILD
75
76    If the current package is '//' (the top-level BUILD file):
77        subpackages.exists("foo") == True
78        subpackages.exists("foo/sub") == False
79        subpackages.exists("bar") == False
80
81    NOTE: fail()s if native.subpackages() is not supported in the current Bazel version.
82
83    Args:
84      relative_path: a path to a subpackage to test, must not be an absolute Label.
85
86    Returns:
87      True if 'relative_path' is a subpackage of the current package.
88    """
89    _check_supported()
90    return relative_path in native.subpackages(include = [relative_path], allow_empty = True)
91
92subpackages = struct(
93    all = _all,
94    exists = _exists,
95    supported = _supported,
96)
97