# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# This source code is licensed under both the MIT license found in the
# LICENSE-MIT file in the root directory of this source tree and the Apache
# License, Version 2.0 found in the LICENSE-APACHE file in the root directory
# of this source tree.
load("@prelude//cfg/modifier:types.bzl", "ConditionalModifierInfo")
load(":util.bzl", "util")
# config_setting() accepts a list of constraint_values and a list of values
# (buckconfig keys + expected values) and matches if all of those match.
#
# This is implemented as forming a single ConfigurationInfo from the union of the
# referenced values and the config keys.
#
# Attributes:
# "constraint_values": attrs.list(attrs.configuration_label(), default = []),
# "values": attrs.dict(key = attrs.string(), value = attrs.string(), sorted = False, default = {}),
def config_setting_impl(ctx):
subinfos = [util.constraint_values_to_configuration(ctx.attrs.constraint_values)]
subinfos.append(ConfigurationInfo(constraints = {}, values = ctx.attrs.values))
return [DefaultInfo(), util.configuration_info_union(subinfos)]
# constraint_setting() targets just declare the existence of a constraint.
def constraint_setting_impl(ctx):
return [DefaultInfo(), ConstraintSettingInfo(label = ctx.label.raw_target())]
# constraint_value() declares a specific value of a constraint_setting.
#
# Attributes:
# constraint_setting: the target constraint that this is a value of
def constraint_value_impl(ctx):
constraint_value = ConstraintValueInfo(
setting = ctx.attrs.constraint_setting[ConstraintSettingInfo],
label = ctx.label.raw_target(),
)
return [
DefaultInfo(),
constraint_value,
# Provide `ConfigurationInfo` from `constraint_value` so it could be used as select key.
ConfigurationInfo(
constraints = {
constraint_value.setting.label: constraint_value,
},
values = {},
),
ConditionalModifierInfo(
inner = constraint_value,
key = constraint_value.setting.label,
),
]
# platform() declares a platform, it is a list of constraint values.
#
# Attributes:
# constraint_values: list of constraint values that are set for this platform
# deps: a list of platform target dependencies, the constraints from these platforms will be part of this platform (unless overridden)
def platform_impl(ctx):
subinfos = (
[dep[PlatformInfo].configuration for dep in ctx.attrs.deps] +
[util.constraint_values_to_configuration(ctx.attrs.constraint_values)]
)
return [
DefaultInfo(),
PlatformInfo(
label = str(ctx.label.raw_target()),
# TODO(nga): current behavior is the last constraint value for constraint setting wins.
# This allows overriding constraint values from dependencies, and moreover,
# it allows overriding constraint values from constraint values listed
# in the same `constraint_values` attribute earlier.
# If this is intentional, state it explicitly.
# Otherwise, fix it.
configuration = util.configuration_info_union(subinfos),
),
]
def configuration_alias_impl(ctx: AnalysisContext) -> list[Provider]:
return ctx.attrs.actual.providers
# TODO(cjhopman): Update the attributes for these ruletypes to declare the types of providers that they expect in their references.
extra_attributes = {
"platform": {
"constraint_values": attrs.list(attrs.dep(providers = [ConstraintValueInfo]), default = []),
},
}
implemented_rules = {
"config_setting": config_setting_impl,
"configuration_alias": configuration_alias_impl,
"constraint_setting": constraint_setting_impl,
"constraint_value": constraint_value_impl,
"platform": platform_impl,
}