Java tutorial
// 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.analysis.configuredtargets; import com.google.common.collect.ImmutableList; import com.google.common.collect.Iterables; import com.google.devtools.build.lib.analysis.AnalysisUtils; import com.google.devtools.build.lib.analysis.ConfiguredAspect; import com.google.devtools.build.lib.analysis.ConfiguredTarget; import com.google.devtools.build.lib.analysis.ExtraActionArtifactsProvider; import com.google.devtools.build.lib.analysis.OutputGroupProvider; import com.google.devtools.build.lib.analysis.TransitiveInfoProvider; import com.google.devtools.build.lib.analysis.TransitiveInfoProviderMap; import com.google.devtools.build.lib.analysis.TransitiveInfoProviderMapBuilder; import com.google.devtools.build.lib.packages.Info; import com.google.devtools.build.lib.packages.Provider; import com.google.devtools.build.lib.packages.Provider.Key; import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter; import java.util.ArrayList; import java.util.List; import java.util.function.Consumer; /** * A single dependency with its configured target and aspects merged together. * * <p>This is an ephemeral object created only for the analysis of a single configured target. After * that configured target is analyzed, this is thrown away. */ public final class MergedConfiguredTarget extends AbstractConfiguredTarget { private final ConfiguredTarget base; private final TransitiveInfoProviderMap providers; /** * This exception is thrown when configured targets and aspects * being merged provide duplicate things that they shouldn't * (output groups or providers). */ public static final class DuplicateException extends Exception { public DuplicateException(String message) { super(message); } } private MergedConfiguredTarget(ConfiguredTarget base, TransitiveInfoProviderMap providers) { super(base.getTarget(), base.getConfiguration()); this.base = base; this.providers = providers; } @Override public <P extends TransitiveInfoProvider> P getProvider(Class<P> providerClass) { AnalysisUtils.checkProvider(providerClass); P provider = providers.getProvider(providerClass); if (provider == null) { provider = base.getProvider(providerClass); } return provider; } @Override protected void addExtraSkylarkKeys(Consumer<String> result) { if (base instanceof AbstractConfiguredTarget) { ((AbstractConfiguredTarget) base).addExtraSkylarkKeys(result); } for (int i = 0; i < providers.getProviderCount(); i++) { Object classAt = providers.getProviderKeyAt(i); if (classAt instanceof String) { result.accept((String) classAt); } } } @Override protected Info rawGetSkylarkProvider(Provider.Key providerKey) { Info provider = providers.getProvider(providerKey); if (provider == null) { provider = base.get(providerKey); } return provider; } @Override protected Object rawGetSkylarkProvider(String providerKey) { Object provider = providers.getProvider(providerKey); if (provider == null) { provider = base.get(providerKey); } return provider; } /** Creates an instance based on a configured target and a set of aspects. */ public static ConfiguredTarget of(ConfiguredTarget base, Iterable<ConfiguredAspect> aspects) throws DuplicateException { if (Iterables.isEmpty(aspects)) { // If there are no aspects, don't bother with creating a proxy object return base; } // Merge output group providers. OutputGroupProvider mergedOutputGroupProvider = OutputGroupProvider .merge(getAllOutputGroupProviders(base, aspects)); // Merge extra-actions provider. ExtraActionArtifactsProvider mergedExtraActionProviders = ExtraActionArtifactsProvider .merge(getAllProviders(base, aspects, ExtraActionArtifactsProvider.class)); TransitiveInfoProviderMapBuilder aspectProviders = new TransitiveInfoProviderMapBuilder(); if (mergedOutputGroupProvider != null) { aspectProviders.put(mergedOutputGroupProvider); } if (mergedExtraActionProviders != null) { aspectProviders.add(mergedExtraActionProviders); } for (ConfiguredAspect aspect : aspects) { TransitiveInfoProviderMap providers = aspect.getProviders(); for (int i = 0; i < providers.getProviderCount(); ++i) { Object providerKey = providers.getProviderKeyAt(i); if (OutputGroupProvider.SKYLARK_CONSTRUCTOR.getKey().equals(providerKey) || ExtraActionArtifactsProvider.class.equals(providerKey)) { continue; } if (providerKey instanceof Class<?>) { @SuppressWarnings("unchecked") Class<? extends TransitiveInfoProvider> providerClass = (Class<? extends TransitiveInfoProvider>) providerKey; if (base.getProvider(providerClass) != null || aspectProviders.contains(providerClass)) { throw new DuplicateException("Provider " + providerKey + " provided twice"); } aspectProviders.put(providerClass, (TransitiveInfoProvider) providers.getProviderInstanceAt(i)); } else if (providerKey instanceof String) { String legacyId = (String) providerKey; if (base.get(legacyId) != null || aspectProviders.contains(legacyId)) { throw new DuplicateException("Provider " + legacyId + " provided twice"); } aspectProviders.put(legacyId, providers.getProviderInstanceAt(i)); } else if (providerKey instanceof Provider.Key) { Provider.Key key = (Key) providerKey; if (base.get(key) != null || aspectProviders.contains(key)) { throw new DuplicateException("Provider " + key + " provided twice"); } aspectProviders.put((Info) providers.getProviderInstanceAt(i)); } } } return new MergedConfiguredTarget(base, aspectProviders.build()); } private static ImmutableList<OutputGroupProvider> getAllOutputGroupProviders(ConfiguredTarget base, Iterable<ConfiguredAspect> aspects) { OutputGroupProvider baseProvider = OutputGroupProvider.get(base); ImmutableList.Builder<OutputGroupProvider> providers = ImmutableList.builder(); if (baseProvider != null) { providers.add(baseProvider); } for (ConfiguredAspect configuredAspect : aspects) { OutputGroupProvider aspectProvider = OutputGroupProvider.get(configuredAspect); if (aspectProvider == null) { continue; } providers.add(aspectProvider); } return providers.build(); } private static <T extends TransitiveInfoProvider> List<T> getAllProviders(ConfiguredTarget base, Iterable<ConfiguredAspect> aspects, Class<T> providerClass) { T baseProvider = base.getProvider(providerClass); List<T> providers = new ArrayList<>(); if (baseProvider != null) { providers.add(baseProvider); } for (ConfiguredAspect configuredAspect : aspects) { T aspectProvider = configuredAspect.getProvider(providerClass); if (aspectProvider == null) { continue; } providers.add(aspectProvider); } return providers; } @Override public void repr(SkylarkPrinter printer) { printer.append("<merged target " + getLabel() + ">"); } }