1# Copyright 2019 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"""Common build setting rules
16These rules return a BuildSettingInfo with the value of the build setting.
17For label-typed settings, use the native label_flag and label_setting rules.
18More documentation on how to use build settings at
19https://docs.bazel.build/versions/master/skylark/config.html#user-defined-build-settings
20"""
21
22BuildSettingInfo = provider(
23    doc = "A singleton provider that contains the raw value of a build setting",
24    fields = {
25        "value": "The value of the build setting in the current configuration. " +
26                 "This value may come from the command line or an upstream transition, " +
27                 "or else it will be the build setting's default.",
28    },
29)
30
31def _impl(ctx):
32    return BuildSettingInfo(value = ctx.build_setting_value)
33
34int_flag = rule(
35    implementation = _impl,
36    build_setting = config.int(flag = True),
37    doc = "An int-typed build setting that can be set on the command line",
38)
39
40int_setting = rule(
41    implementation = _impl,
42    build_setting = config.int(),
43    doc = "An int-typed build setting that cannot be set on the command line",
44)
45
46bool_flag = rule(
47    implementation = _impl,
48    build_setting = config.bool(flag = True),
49    doc = "A bool-typed build setting that can be set on the command line",
50)
51
52bool_setting = rule(
53    implementation = _impl,
54    build_setting = config.bool(),
55    doc = "A bool-typed build setting that cannot be set on the command line",
56)
57
58string_list_flag = rule(
59    implementation = _impl,
60    build_setting = config.string_list(flag = True),
61    doc = "A string list-typed build setting that can be set on the command line",
62)
63
64string_list_setting = rule(
65    implementation = _impl,
66    build_setting = config.string_list(),
67    doc = "A string list-typed build setting that cannot be set on the command line",
68)
69
70def _string_impl(ctx):
71    allowed_values = ctx.attr.values
72    value = ctx.build_setting_value
73    if len(allowed_values) == 0 or value in ctx.attr.values:
74        return BuildSettingInfo(value = value)
75    else:
76        fail("Error setting " + str(ctx.label) + ": invalid value '" + value + "'. Allowed values are " + str(allowed_values))
77
78string_flag = rule(
79    implementation = _string_impl,
80    build_setting = config.string(flag = True),
81    attrs = {
82        "values": attr.string_list(
83            doc = "The list of allowed values for this setting. An error is raised if any other value is given.",
84        ),
85    },
86    doc = "A string-typed build setting that can be set on the command line",
87)
88
89string_setting = rule(
90    implementation = _string_impl,
91    build_setting = config.string(),
92    attrs = {
93        "values": attr.string_list(
94            doc = "The list of allowed values for this setting. An error is raised if any other value is given.",
95        ),
96    },
97    doc = "A string-typed build setting that cannot be set on the command line",
98)
99