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// 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;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.packages.SkylarkClassObject;
import com.google.devtools.build.lib.packages.SkylarkClassObjectConstructor.Key;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
/**
* 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 ImmutableList<AspectDescriptor> aspects;
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,
ImmutableList<AspectDescriptor> aspects,
TransitiveInfoProviderMap providers) {
super(base.getTarget(), base.getConfiguration());
this.base = base;
this.aspects = aspects;
this.providers = providers;
}
/** Returns a value provided by this target. Only meant to use from Skylark. */
@Override
public Object get(String providerKey) {
return getProvider(SkylarkProviders.class).getValue(providerKey);
}
@Nullable
@Override
public SkylarkClassObject get(Key providerKey) {
return getProvider(SkylarkProviders.class).getDeclaredProvider(providerKey);
}
@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;
}
/**
* List of aspects applied to the target.
*/
public ImmutableList<AspectDescriptor> getAspects() {
return aspects;
}
@Override
public Object getValue(String name) {
if (ASPECTS_FIELD.equals(name)) {
ImmutableList.Builder<String> builder = ImmutableList.builder();
for (AspectDescriptor aspect : aspects) {
builder.add(aspect.getDescription());
}
return builder.build();
}
return super.getValue(name);
}
/** 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(getAllProviders(base, aspects, OutputGroupProvider.class));
// Merge Skylark providers.
ImmutableMap<String, Object> premergedProviders =
mergedOutputGroupProvider == null
? ImmutableMap.<String, Object>of()
: ImmutableMap.<String, Object>of(
OutputGroupProvider.SKYLARK_NAME, mergedOutputGroupProvider);
SkylarkProviders mergedSkylarkProviders =
SkylarkProviders.merge(
premergedProviders,
getAllProviders(base, aspects, SkylarkProviders.class));
// Merge extra-actions provider.
ExtraActionArtifactsProvider mergedExtraActionProviders = ExtraActionArtifactsProvider.merge(
getAllProviders(base, aspects, ExtraActionArtifactsProvider.class));
TransitiveInfoProviderMap.Builder aspectProviders = TransitiveInfoProviderMap.builder();
if (mergedOutputGroupProvider != null) {
aspectProviders.add(mergedOutputGroupProvider);
}
if (mergedSkylarkProviders != null) {
aspectProviders.add(mergedSkylarkProviders);
}
if (mergedExtraActionProviders != null) {
aspectProviders.add(mergedExtraActionProviders);
}
ImmutableList.Builder<AspectDescriptor> aspectDescriptors = ImmutableList.builder();
for (ConfiguredAspect aspect : aspects) {
for (Map.Entry<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider> entry :
aspect.getProviders().entrySet()) {
Class<? extends TransitiveInfoProvider> providerClass = entry.getKey();
if (OutputGroupProvider.class.equals(providerClass)
|| SkylarkProviders.class.equals(providerClass)
|| ExtraActionArtifactsProvider.class.equals(providerClass)) {
continue;
}
if (base.getProvider(providerClass) != null || aspectProviders.contains(providerClass)) {
throw new IllegalStateException("Provider " + providerClass + " provided twice");
}
aspectProviders.add(entry.getValue());
}
aspectDescriptors.add(aspect.getDescriptor());
}
return new MergedConfiguredTarget(base, aspectDescriptors.build(), aspectProviders.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;
}
}