com.google.devtools.build.lib.rules.AliasConfiguredTarget.java Source code

Introduction

Here is the source code for com.google.devtools.build.lib.rules.AliasConfiguredTarget.java

Source

// Copyright 2016 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;

import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.FileProvider;
import com.google.devtools.build.lib.analysis.SkylarkProviders;
import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
import com.google.devtools.build.lib.collect.nestedset.Order;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.events.Location;
import com.google.devtools.build.lib.packages.SkylarkClassObject;
import com.google.devtools.build.lib.packages.SkylarkClassObjectConstructor.Key;
import com.google.devtools.build.lib.packages.SkylarkProviderIdentifier;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.syntax.ClassObject;
import com.google.devtools.build.lib.syntax.EvalException;
import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
import com.google.devtools.build.lib.util.Preconditions;
import javax.annotation.Nullable;

/**
 * This configured target pretends to be whatever type of target "actual" is, returning its
 * transitive info providers and target, but returning its own label.
 *
 * <p>Transitive info providers can also be overridden.
 */
@Immutable
public final class AliasConfiguredTarget implements ConfiguredTarget, ClassObject {
    private final BuildConfiguration configuration;
    private final ConfiguredTarget actual;
    private final ImmutableMap<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider> overrides;

    public AliasConfiguredTarget(BuildConfiguration configuration, @Nullable ConfiguredTarget actual,
            ImmutableMap<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider> overrides) {
        this.configuration = Preconditions.checkNotNull(configuration);
        this.actual = actual;
        this.overrides = Preconditions.checkNotNull(overrides);
    }

    @Override
    public <P extends TransitiveInfoProvider> P getProvider(Class<P> provider) {
        if (overrides.containsKey(provider)) {
            return provider.cast(overrides.get(provider));
        }

        return actual == null ? null : actual.getProvider(provider);
    }

    @Override
    public Label getLabel() {
        return actual.getLabel();
    }

    @Override
    public Object get(String providerKey) {
        return actual == null ? null : actual.get(providerKey);
    }

    @Nullable
    @Override
    public SkylarkClassObject get(Key providerKey) {
        return actual == null ? null : actual.get(providerKey);
    }

    @Nullable
    @Override
    public Object get(SkylarkProviderIdentifier id) {
        return actual == null ? null : actual.get(id);
    }

    @Override
    public Object getIndex(Object key, Location loc) throws EvalException {
        return actual == null ? null : actual.getIndex(key, loc);
    }

    @Override
    public boolean containsKey(Object key, Location loc) throws EvalException {
        return actual != null && actual.containsKey(key, loc);
    }

    @Override
    public Target getTarget() {
        return actual == null ? null : actual.getTarget();
    }

    @Override
    public BuildConfiguration getConfiguration() {
        // This does not return actual.getConfiguration() because actual might be an input file, in
        // which case its configuration is null and we don't want to have rules that have a null
        // configuration.
        return configuration;
    }

    /* ClassObject methods */

    @Override
    public Object getValue(String name) {
        if (name.equals(LABEL_FIELD)) {
            return getLabel();
        } else if (name.equals(FILES_FIELD)) {
            // A shortcut for files to build in Skylark. FileConfiguredTarget and RuleConfiguredTarget
            // always has FileProvider and Error- and PackageGroupConfiguredTarget-s shouldn't be
            // accessible in Skylark.
            return SkylarkNestedSet.of(Artifact.class,
                    actual == null ? NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER)
                            : getProvider(FileProvider.class).getFilesToBuild());
        }
        if (actual instanceof ClassObject) {
            return ((ClassObject) actual).getValue(name);
        }
        return actual == null ? null : actual.get(name);
    }

    @Override
    public ImmutableCollection<String> getKeys() {
        ImmutableList.Builder<String> result = ImmutableList.<String>builder().add("label", "files");
        if (actual != null) {
            result.addAll(actual.getProvider(SkylarkProviders.class).getKeys());
        }
        return result.build();
    }

    @Override
    public String errorMessage(String name) {
        // Use the default error message.
        return null;
    }
}