1 files changed, 205 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/MergedConfiguredTarget.java b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/MergedConfiguredTarget.java
new file mode 100644
index 0000000000..da8eb70f4f
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/MergedConfiguredTarget.java
@@ -0,0 +1,205 @@
+// 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() + ">");
+  }
+}