| // Copyright 2014 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. |
| |
| package com.google.devtools.build.lib.analysis.config; |
| |
| import com.google.auto.value.AutoValue; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableMultimap; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.devtools.build.lib.analysis.TransitiveInfoProvider; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import java.util.Map; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A "configuration target" that asserts whether or not it matches the configuration it's bound to. |
| * |
| * <p>This can be used, e.g., to declare a BUILD target that defines the conditions which trigger a |
| * configurable attribute branch. In general, this can be used to trigger for any user-configurable |
| * build behavior. |
| */ |
| @Immutable |
| @AutoValue |
| public abstract class ConfigMatchingProvider implements TransitiveInfoProvider { |
| /** |
| * Potential values for result field. |
| * |
| * <p>Note that while it is possible to be more aggressive in interpreting and merging |
| * MatchResult, currently taking a more cautious approach and focusing on propagating errors. |
| * |
| * <p>e.g. If merging where one is InError and the other is No, then currently will propagate the |
| * errors, versus a more aggressive future approach could just propagate No.) |
| */ |
| // TODO(twigg): This is more cleanly implemented when Java record is available. |
| public static interface MatchResult { |
| // Only InError should return non-null. |
| public abstract @Nullable String getError(); |
| |
| public static final MatchResult MATCH = HasResult.MATCH; |
| public static final MatchResult NOMATCH = HasResult.NOMATCH; |
| |
| /** Some specified error makes the match question irresolvable. */ |
| @AutoValue |
| public abstract class InError implements MatchResult { |
| public static InError create(String error) { |
| return new AutoValue_ConfigMatchingProvider_MatchResult_InError(error); |
| } |
| } |
| |
| public static MatchResult create(boolean matches) { |
| return matches ? MATCH : NOMATCH; |
| } |
| |
| /** If previously InError or No, keep previous else convert newData. */ |
| public static MatchResult merge(MatchResult previousMatch, boolean andWith) { |
| if (!previousMatch.equals(MATCH)) { |
| return previousMatch; |
| } |
| return andWith ? MATCH : NOMATCH; |
| } |
| } |
| |
| /** |
| * The result was resolved. |
| * |
| * <p>Using an enum to get convenient toString, equals, and hashCode implementations. Interfaces |
| * can't have private members so this is defined here privately and then exported into the |
| * MatchResult interface to allow for ergonomic MatchResult.MATCH checks. |
| */ |
| private static enum HasResult implements MatchResult { |
| MATCH, |
| NOMATCH; |
| |
| @Override |
| public @Nullable String getError() { |
| return null; |
| } |
| } |
| |
| /** |
| * Create a ConfigMatchingProvider. |
| * |
| * @param label the build label corresponding to this matcher |
| * @param settingsMap the condition settings that trigger this matcher |
| * @param flagSettingsMap the label-keyed settings that trigger this matcher |
| * @param result whether the current associated configuration matches, doesn't match, or is |
| * irresolvable due to specified issue |
| */ |
| public static ConfigMatchingProvider create( |
| Label label, |
| ImmutableMultimap<String, String> settingsMap, |
| ImmutableMap<Label, String> flagSettingsMap, |
| ImmutableSet<Label> constraintValueSettings, |
| MatchResult result) { |
| return new AutoValue_ConfigMatchingProvider( |
| label, settingsMap, flagSettingsMap, constraintValueSettings, result); |
| } |
| |
| /** The target's label. */ |
| public abstract Label label(); |
| |
| public abstract ImmutableMultimap<String, String> settingsMap(); |
| |
| public abstract ImmutableMap<Label, String> flagSettingsMap(); |
| |
| public abstract ImmutableSet<Label> constraintValuesSetting(); |
| |
| /** |
| * Whether or not the configuration criteria defined by this target match its actual |
| * configuration. |
| */ |
| public abstract MatchResult result(); |
| |
| /** |
| * Returns true if this matcher's conditions are a proper superset of another matcher's |
| * conditions, i.e. if this matcher is a specialization of the other one. |
| */ |
| public boolean refines(ConfigMatchingProvider other) { |
| ImmutableSet<Map.Entry<String, String>> settings = ImmutableSet.copyOf(settingsMap().entries()); |
| ImmutableSet<Map.Entry<String, String>> otherSettings = |
| ImmutableSet.copyOf(other.settingsMap().entries()); |
| ImmutableSet<Map.Entry<Label, String>> flagSettings = flagSettingsMap().entrySet(); |
| ImmutableSet<Map.Entry<Label, String>> otherFlagSettings = other.flagSettingsMap().entrySet(); |
| |
| ImmutableSet<Label> constraintValueSettings = constraintValuesSetting(); |
| ImmutableSet<Label> otherConstraintValueSettings = other.constraintValuesSetting(); |
| |
| if (!settings.containsAll(otherSettings) |
| || !flagSettings.containsAll(otherFlagSettings) |
| || !constraintValueSettings.containsAll(otherConstraintValueSettings)) { |
| return false; // Not a superset. |
| } |
| |
| return settings.size() > otherSettings.size() |
| || flagSettings.size() > otherFlagSettings.size() |
| || constraintValueSettings.size() > otherConstraintValueSettings.size(); |
| } |
| |
| /** Format this provider as its label. */ |
| @Override |
| public final String toString() { |
| return label().toString(); |
| } |
| } |