| // Copyright 2018 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.rules.config; |
| |
| import com.google.auto.value.AutoValue; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.Sets; |
| import com.google.devtools.build.lib.analysis.config.BuildOptions; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import java.util.LinkedHashMap; |
| import java.util.LinkedHashSet; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** Marker interface for detecting feature flags in the Starlark setting map. */ |
| public interface FeatureFlagValue { |
| /** A feature flag value for a flag known to be set to a particular value. */ |
| @AutoValue |
| abstract class SetValue implements FeatureFlagValue { |
| static SetValue of(String value) { |
| return new AutoValue_FeatureFlagValue_SetValue(value); |
| } |
| |
| public abstract String value(); |
| |
| @Override |
| public final String toString() { |
| return String.format("FeatureFlagValue.SetValue{%s}", value()); |
| } |
| } |
| |
| /** A feature flag value for a flag known to be set to its default value. */ |
| enum DefaultValue implements FeatureFlagValue { |
| INSTANCE; |
| |
| @Override |
| public String toString() { |
| return "FeatureFlagValue.DefaultValue{}"; |
| } |
| } |
| |
| /** A feature flag value for a flag which was requested but which value was already trimmed. */ |
| enum UnknownValue implements FeatureFlagValue { |
| INSTANCE; |
| |
| @Override |
| public String toString() { |
| return "FeatureFlagValue.UnknownValue{}"; |
| } |
| } |
| |
| /** Returns a new BuildOptions with a new map of feature flag values. */ |
| static BuildOptions replaceFlagValues(BuildOptions original, Map<Label, String> newValues) { |
| BuildOptions.Builder result = original.toBuilder(); |
| for (Map.Entry<Label, Object> entry : original.getStarlarkOptions().entrySet()) { |
| if (entry.getValue() instanceof FeatureFlagValue) { |
| result.removeStarlarkOption(entry.getKey()); |
| } |
| } |
| ImmutableMap.Builder<Label, Object> newValueObjects = new ImmutableMap.Builder<>(); |
| for (Map.Entry<Label, String> entry : newValues.entrySet()) { |
| newValueObjects.put(entry.getKey(), SetValue.of(entry.getValue())); |
| } |
| result.addStarlarkOptions(newValueObjects.buildOrThrow()); |
| BuildOptions builtResult = result.build(); |
| if (builtResult.contains(ConfigFeatureFlagOptions.class)) { |
| builtResult.get(ConfigFeatureFlagOptions.class).allFeatureFlagValuesArePresent = true; |
| } |
| return builtResult; |
| } |
| |
| /** Returns a new BuildOptions with the feature flag values trimmed down to the given flags. */ |
| static BuildOptions trimFlagValues(BuildOptions original, Set<Label> availableFlags) { |
| // An important performance property of this method is that we don't create a new BuildOptions |
| // instance unless we really need one. This particularly saves the expensive cost of |
| // BuildOptions.hashCode(). Since this method is called unconditionally over every configured |
| // target, this has real observable effect on build analysis time. |
| Set<Label> seenFlags = new LinkedHashSet<>(); |
| Set<Label> flagsToTrim = new LinkedHashSet<>(); |
| Map<Label, Object> unknownFlagsToAdd = new LinkedHashMap<>(); |
| boolean changeAllValuesPresentOption = false; |
| if (original.contains(ConfigFeatureFlagOptions.class)) { |
| changeAllValuesPresentOption = |
| original.get(ConfigFeatureFlagOptions.class).allFeatureFlagValuesArePresent; |
| } |
| |
| // What do we need to change? |
| original.getStarlarkOptions().entrySet().stream() |
| .filter(entry -> entry.getValue() instanceof FeatureFlagValue) |
| .forEach(featureFlagEntry -> seenFlags.add(featureFlagEntry.getKey())); |
| flagsToTrim.addAll(Sets.difference(seenFlags, availableFlags)); |
| FeatureFlagValue unknownFlagValue = |
| changeAllValuesPresentOption ? DefaultValue.INSTANCE : UnknownValue.INSTANCE; |
| for (Label unknownFlag : Sets.difference(availableFlags, seenFlags)) { |
| unknownFlagsToAdd.put(unknownFlag, unknownFlagValue); |
| } |
| |
| // Nothing changed? Return the original BuildOptions. |
| if (flagsToTrim.isEmpty() && unknownFlagsToAdd.isEmpty() && !changeAllValuesPresentOption) { |
| return original; |
| } |
| |
| // Else construct a new one. This should not be the common case. |
| BuildOptions.Builder result = original.toBuilder(); |
| flagsToTrim.forEach(trimmedFlag -> result.removeStarlarkOption(trimmedFlag)); |
| unknownFlagsToAdd.forEach((flag, value) -> result.addStarlarkOption(flag, value)); |
| BuildOptions builtResult = result.build(); |
| if (builtResult.contains(ConfigFeatureFlagOptions.class)) { |
| builtResult.get(ConfigFeatureFlagOptions.class).allFeatureFlagValuesArePresent = false; |
| } |
| return builtResult; |
| } |
| } |