| // Copyright 2017 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 static com.google.devtools.build.lib.collect.nestedset.Order.STABLE_ORDER; |
| import static com.google.devtools.build.lib.syntax.Type.STRING; |
| import static com.google.devtools.build.lib.syntax.Type.STRING_LIST; |
| |
| import com.google.common.base.Predicate; |
| import com.google.common.base.Predicates; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMultiset; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Multiset; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.actions.MutableActionGraph.ActionConflictException; |
| import com.google.devtools.build.lib.analysis.ConfiguredTarget; |
| import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder; |
| import com.google.devtools.build.lib.analysis.RuleConfiguredTargetFactory; |
| import com.google.devtools.build.lib.analysis.RuleContext; |
| import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment; |
| import com.google.devtools.build.lib.analysis.RunfilesProvider; |
| import com.google.devtools.build.lib.analysis.Whitelist; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder; |
| import com.google.devtools.build.lib.packages.Attribute; |
| import com.google.devtools.build.lib.packages.Attribute.ComputedDefault; |
| import com.google.devtools.build.lib.packages.AttributeMap; |
| import com.google.devtools.build.lib.syntax.Printer; |
| import java.util.List; |
| import java.util.Optional; |
| |
| /** |
| * The implementation of the config_feature_flag rule for defining custom flags for Android rules. |
| */ |
| public class ConfigFeatureFlag implements RuleConfiguredTargetFactory { |
| /** The name of the policy that is used to restrict access to the config_feature_flag rule. */ |
| private static final String WHITELIST_NAME = "config_feature_flag"; |
| |
| /** The label of the policy that is used to restrict access to the config_feature_flag rule. */ |
| private static final String WHITELIST_LABEL = |
| "//tools/whitelists/config_feature_flag:config_feature_flag"; |
| |
| /** Constructs a definition for the attribute used to restrict access to config_feature_flag. */ |
| public static Attribute.Builder<Label> getWhitelistAttribute(RuleDefinitionEnvironment env) { |
| return Whitelist.getAttributeFromWhitelistName(WHITELIST_NAME) |
| .value(env.getToolsLabel(WHITELIST_LABEL)); |
| } |
| |
| /** |
| * Constructs a definition for the attribute used to restrict access to config_feature_flag. The |
| * whitelist will only be reached if the given {@code attributeToInspect} has a value explicitly |
| * specified. It must be non-configurable. |
| */ |
| public static Attribute.Builder<Label> getWhitelistAttribute( |
| RuleDefinitionEnvironment env, String attributeToInspect) { |
| final Label label = env.getToolsLabel(WHITELIST_LABEL); |
| return Whitelist.getAttributeFromWhitelistName(WHITELIST_NAME) |
| .value( |
| new ComputedDefault() { |
| @Override |
| public Label getDefault(AttributeMap rule) { |
| return rule.isAttributeValueExplicitlySpecified(attributeToInspect) ? label : null; |
| } |
| }); |
| } |
| |
| /** |
| * Returns whether config_feature_flag and related features are available to the current rule. |
| * |
| * <p>The current rule must have an attribute defined on it created with {@link |
| * #getWhitelistAttribute}. |
| */ |
| public static boolean isAvailable(RuleContext ruleContext) { |
| return Whitelist.isAvailable(ruleContext, WHITELIST_NAME); |
| } |
| |
| @Override |
| public ConfiguredTarget create(RuleContext ruleContext) |
| throws InterruptedException, RuleErrorException, ActionConflictException { |
| if (!ConfigFeatureFlag.isAvailable(ruleContext)) { |
| ruleContext.ruleError( |
| String.format( |
| "the %s rule is not available in package '%s'", |
| ruleContext.getRuleClassNameForLogging(), |
| ruleContext.getLabel().getPackageIdentifier())); |
| throw new RuleErrorException(); |
| } |
| |
| List<String> specifiedValues = ruleContext.attributes().get("allowed_values", STRING_LIST); |
| ImmutableSet<String> values = ImmutableSet.copyOf(specifiedValues); |
| Predicate<String> isValidValue = Predicates.in(values); |
| if (values.size() != specifiedValues.size()) { |
| ImmutableMultiset<String> groupedValues = ImmutableMultiset.copyOf(specifiedValues); |
| ImmutableList.Builder<String> duplicates = new ImmutableList.Builder<String>(); |
| for (Multiset.Entry<String> value : groupedValues.entrySet()) { |
| if (value.getCount() > 1) { |
| duplicates.add(value.getElement()); |
| } |
| } |
| ruleContext.attributeError( |
| "allowed_values", |
| "cannot contain duplicates, but contained multiple of " |
| + Printer.repr(duplicates.build())); |
| } |
| |
| Optional<String> defaultValue = |
| ruleContext.attributes().isAttributeValueExplicitlySpecified("default_value") |
| ? Optional.of(ruleContext.attributes().get("default_value", STRING)) |
| : Optional.empty(); |
| if (defaultValue.isPresent() && !isValidValue.apply(defaultValue.get())) { |
| ruleContext.attributeError( |
| "default_value", |
| "must be one of " |
| + Printer.repr(values.asList()) |
| + ", but was " |
| + Printer.repr(defaultValue.get())); |
| } |
| |
| if (ruleContext.hasErrors()) { |
| // Don't bother validating the value if the flag was already incorrectly specified without |
| // looking at the value. |
| return null; |
| } |
| |
| Optional<String> configuredValue = |
| ruleContext |
| .getFragment(ConfigFeatureFlagConfiguration.class) |
| .getFeatureFlagValue(ruleContext.getOwner()); |
| |
| if (configuredValue.isPresent() && !isValidValue.apply(configuredValue.get())) { |
| // TODO(mstaib): When configurationError is available, use that instead. |
| ruleContext.ruleError( |
| "value must be one of " |
| + Printer.repr(values.asList()) |
| + ", but was " |
| + Printer.repr(configuredValue.get())); |
| return null; |
| } |
| |
| if (!configuredValue.isPresent() && !defaultValue.isPresent()) { |
| // TODO(mstaib): When configurationError is available, use that instead. |
| ruleContext.ruleError("flag has no default and must be set, but was not set"); |
| return null; |
| } |
| |
| String value = configuredValue.orElseGet(defaultValue::get); |
| |
| ConfigFeatureFlagProvider provider = ConfigFeatureFlagProvider.create(value, isValidValue); |
| |
| return new RuleConfiguredTargetBuilder(ruleContext) |
| .setFilesToBuild(NestedSetBuilder.<Artifact>emptySet(STABLE_ORDER)) |
| .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY) |
| .addNativeDeclaredProvider(provider) |
| .build(); |
| } |
| } |