Java tutorial
// 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.configuredtargets; import com.google.common.collect.ImmutableCollection; import com.google.common.collect.ImmutableList; import com.google.devtools.build.lib.analysis.AnalysisUtils; import com.google.devtools.build.lib.analysis.ConfiguredTarget; import com.google.devtools.build.lib.analysis.DefaultInfo; import com.google.devtools.build.lib.analysis.FileProvider; import com.google.devtools.build.lib.analysis.FilesToRunProvider; import com.google.devtools.build.lib.analysis.OutputGroupProvider; import com.google.devtools.build.lib.analysis.RunfilesProvider; import com.google.devtools.build.lib.analysis.TargetContext; import com.google.devtools.build.lib.analysis.TransitiveInfoProvider; import com.google.devtools.build.lib.analysis.VisibilityProvider; 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.NestedSet; import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder; import com.google.devtools.build.lib.collect.nestedset.Order; import com.google.devtools.build.lib.events.Location; import com.google.devtools.build.lib.packages.Info; import com.google.devtools.build.lib.packages.PackageSpecification; import com.google.devtools.build.lib.packages.Provider; import com.google.devtools.build.lib.packages.Target; import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter; import com.google.devtools.build.lib.syntax.ClassObject; import com.google.devtools.build.lib.syntax.EvalException; import com.google.devtools.build.lib.syntax.EvalUtils; import com.google.devtools.build.lib.syntax.Printer; import java.util.concurrent.atomic.AtomicReference; import java.util.function.Consumer; import javax.annotation.Nullable; /** * An abstract implementation of ConfiguredTarget in which all properties are * assigned trivial default values. */ public abstract class AbstractConfiguredTarget implements ConfiguredTarget, VisibilityProvider, ClassObject { private final Target target; private final BuildConfiguration configuration; private final NestedSet<PackageSpecification> visibility; // Cached on-demand default provider private final AtomicReference<DefaultInfo> defaultProvider = new AtomicReference<>(); // Accessors for Skylark private static final String DATA_RUNFILES_FIELD = "data_runfiles"; private static final String DEFAULT_RUNFILES_FIELD = "default_runfiles"; public AbstractConfiguredTarget(Target target, BuildConfiguration configuration) { this.target = target; this.configuration = configuration; this.visibility = NestedSetBuilder.emptySet(Order.STABLE_ORDER); } public AbstractConfiguredTarget(TargetContext targetContext) { this.target = targetContext.getTarget(); this.configuration = targetContext.getConfiguration(); this.visibility = targetContext.getVisibility(); } @Override public final NestedSet<PackageSpecification> getVisibility() { return visibility; } @Override public Target getTarget() { return target; } @Override public BuildConfiguration getConfiguration() { return configuration; } @Override public Label getLabel() { return getTarget().getLabel(); } @Override public String toString() { return "ConfiguredTarget(" + getTarget().getLabel() + ", " + getConfiguration() + ")"; } @Override public <P extends TransitiveInfoProvider> P getProvider(Class<P> provider) { AnalysisUtils.checkProvider(provider); if (provider.isAssignableFrom(getClass())) { return provider.cast(this); } else { return null; } } @Override public Object getValue(String name) { switch (name) { case LABEL_FIELD: return getLabel(); default: return get(name); } } @Override public final Object getIndex(Object key, Location loc) throws EvalException { if (!(key instanceof Provider)) { throw new EvalException(loc, String.format("Type Target only supports indexing by object constructors, got %s instead", EvalUtils.getDataTypeName(key))); } Provider constructor = (Provider) key; Object declaredProvider = get(constructor.getKey()); if (declaredProvider != null) { return declaredProvider; } throw new EvalException(loc, Printer.format("%r%s doesn't contain declared provider '%s'", this, getTarget().getAssociatedRule() == null ? "" : " (rule '" + getTarget().getAssociatedRule().getRuleClass() + "')", constructor.getPrintableName())); } @Override public boolean containsKey(Object key, Location loc) throws EvalException { if (!(key instanceof Provider)) { throw new EvalException(loc, String.format("Type Target only supports querying by object constructors, got %s instead", EvalUtils.getDataTypeName(key))); } return get(((Provider) key).getKey()) != null; } @Override public String errorMessage(String name) { return null; } @Override public final ImmutableCollection<String> getKeys() { ImmutableList.Builder<String> result = ImmutableList.builder(); result.addAll(ImmutableList.of(DATA_RUNFILES_FIELD, DEFAULT_RUNFILES_FIELD, LABEL_FIELD, FILES_FIELD, FilesToRunProvider.SKYLARK_NAME)); if (get(OutputGroupProvider.SKYLARK_CONSTRUCTOR) != null) { result.add(OutputGroupProvider.SKYLARK_NAME); } addExtraSkylarkKeys(result::add); return result.build(); } protected void addExtraSkylarkKeys(Consumer<String> result) { } private DefaultInfo getDefaultProvider() { if (defaultProvider.get() == null) { defaultProvider.compareAndSet(null, DefaultInfo.build(getProvider(RunfilesProvider.class), getProvider(FileProvider.class), getProvider(FilesToRunProvider.class))); } return defaultProvider.get(); } /** Returns a declared provider provided by this target. Only meant to use from Skylark. */ @Nullable @Override public final Info get(Provider.Key providerKey) { if (providerKey.equals(DefaultInfo.PROVIDER.getKey())) { return getDefaultProvider(); } return rawGetSkylarkProvider(providerKey); } /** Implement in subclasses to get a skylark provider for a given {@code providerKey}. */ @Nullable protected abstract Info rawGetSkylarkProvider(Provider.Key providerKey); /** * Returns a value provided by this target. Only meant to use from Skylark. */ @Override public final Object get(String providerKey) { if (OutputGroupProvider.SKYLARK_NAME.equals(providerKey)) { return get(OutputGroupProvider.SKYLARK_CONSTRUCTOR); } switch (providerKey) { case FILES_FIELD: case DEFAULT_RUNFILES_FIELD: case DATA_RUNFILES_FIELD: case FilesToRunProvider.SKYLARK_NAME: // Standard fields should be proxied to their default provider object return getDefaultProvider().getValue(providerKey); case OutputGroupProvider.SKYLARK_NAME: return get(OutputGroupProvider.SKYLARK_CONSTRUCTOR); default: return rawGetSkylarkProvider(providerKey); } } /** Implement in subclasses to get a skylark provider for a given {@code providerKey}. */ protected abstract Object rawGetSkylarkProvider(String providerKey); // All main target classes must override this method to provide more descriptive strings. // Exceptions are currently EnvironmentGroupConfiguredTarget and PackageGroupConfiguredTarget. @Override public void repr(SkylarkPrinter printer) { printer.append("<unknown target " + getTarget().getLabel() + ">"); } }