// Copyright 2015 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,
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package com.google.devtools.build.lib.analysis.constraints;
import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.packages.Target;
/**
* A provider that advertises which environments the associated target is compatible with
* (from the point of view of the constraint enforcement system).
*/
public interface SupportedEnvironmentsProvider extends TransitiveInfoProvider {
/**
* Returns the static environments this target is compatible with. Static environments
* are those that are independent of build configuration (e.g. declared in {@code restricted_to} /
* {@code compatible_with}). See {@link ConstraintSemantics} for details.
*/
EnvironmentCollection getStaticEnvironments();
/**
* Returns the refined environments this rule is compatible with. Refined environments are
* static environments with unsupported environments from {@code select}able deps removed (on the
* principle that others paths in the select would have provided those environments, so this rule
* is "refined" to match whichever deps got chosen).
*
* <p>>Refined environments require knowledge of the build configuration. See
* {@link ConstraintSemantics} for details.
*/
EnvironmentCollection getRefinedEnvironments();
/**
* If the given environment was refined away from this target's set of supported environments,
* returns the dependency that originally removed the environment.
*
* <p>For example, if the current rule is restricted_to [E] and depends on D1, D1 is
* restricted_to [E] and depends on D2, and D2 is restricted_to [E, F] and has a select()
* with one path following an E-restricted dep and the other path following an F-restricted dep,
* then when the build chooses the F path the current rule has [E] refined to [] and D2 is the
* culprit.
*
* <p>If the given environment was not refined away for this rule, returns null.
*
* <p>See {@link ConstraintSemantics} class documentation for more details on refinement.
*/
Target getRemovedEnvironmentCulprit(Label environment);
}