1 files changed, 120 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/DwoArtifactsCollector.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/DwoArtifactsCollector.java
new file mode 100644
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--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/DwoArtifactsCollector.java
@@ -0,0 +1,120 @@
+// Copyright 2014 Google Inc. 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.cpp;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
+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;
+
+/**
+ * Provides generic functionality for collecting the .dwo artifacts produced by any target
+ * that compiles C++ files. Supports both transitive and "only direct outputs" collection.
+ * Provides accessors for both PIC and non-PIC compilation modes.
+ */
+public class DwoArtifactsCollector {
+
+  /**
+   * The .dwo files collected by this target in non-PIC compilation mode (i.e. myobject.dwo).
+   */
+  private final NestedSet<Artifact> dwoArtifacts;
+
+  /**
+   * The .dwo files collected by this target in PIC compilation mode (i.e. myobject.pic.dwo).
+   */
+  private final NestedSet<Artifact> picDwoArtifacts;
+
+  /**
+   * Instantiates a "real" collector on meaningful data.
+   */
+  private DwoArtifactsCollector(CcCompilationOutputs compilationOutputs,
+        Iterable<TransitiveInfoCollection> deps) {
+
+    Preconditions.checkNotNull(compilationOutputs);
+    Preconditions.checkNotNull(deps);
+
+    // Note: .dwo collection works fine with any order, but tests may assume a
+    // specific order for readability / simplicity purposes. See
+    // DebugInfoPackagingTest for details.
+    NestedSetBuilder<Artifact> dwoBuilder = NestedSetBuilder.compileOrder();
+    NestedSetBuilder<Artifact> picDwoBuilder = NestedSetBuilder.compileOrder();
+
+    dwoBuilder.addAll(compilationOutputs.getDwoFiles());
+    picDwoBuilder.addAll(compilationOutputs.getPicDwoFiles());
+
+    for (TransitiveInfoCollection info : deps) {
+      CppDebugFileProvider provider = info.getProvider(CppDebugFileProvider.class);
+      if (provider != null) {
+        dwoBuilder.addTransitive(provider.getTransitiveDwoFiles());
+        picDwoBuilder.addTransitive(provider.getTransitivePicDwoFiles());
+      }
+    }
+
+    dwoArtifacts = dwoBuilder.build();
+    picDwoArtifacts = picDwoBuilder.build();
+  }
+
+  /**
+   * Instantiates an empty collector.
+   */
+  private DwoArtifactsCollector() {
+    dwoArtifacts = NestedSetBuilder.<Artifact>emptySet(Order.COMPILE_ORDER);
+    picDwoArtifacts = NestedSetBuilder.<Artifact>emptySet(Order.COMPILE_ORDER);
+  }
+
+  /**
+   * Returns a new instance that collects direct outputs and transitive dependencies.
+   *
+   * @param compilationOutputs the output compilation context for the owning target
+   * @param deps which of the target's transitive info collections should be visited
+   */
+  public static DwoArtifactsCollector transitiveCollector(CcCompilationOutputs compilationOutputs,
+      Iterable<TransitiveInfoCollection> deps) {
+    return new DwoArtifactsCollector(compilationOutputs, deps);
+  }
+
+  /**
+   * Returns a new instance that collects direct outputs only.
+   *
+   * @param compilationOutputs the output compilation context for the owning target
+   */
+  public static DwoArtifactsCollector directCollector(CcCompilationOutputs compilationOutputs) {
+      return new DwoArtifactsCollector(
+          compilationOutputs, ImmutableList.<TransitiveInfoCollection>of());
+  }
+
+  /**
+   * Returns a new instance that doesn't collect anything (its artifact sets are empty).
+   */
+  public static DwoArtifactsCollector emptyCollector() {
+    return new DwoArtifactsCollector();
+  }
+
+  /**
+   * Returns the .dwo files applicable to non-PIC compilation mode (i.e. myobject.dwo).
+   */
+  public NestedSet<Artifact> getDwoArtifacts() {
+    return dwoArtifacts;
+  }
+
+  /**
+   * Returns the .dwo files applicable to PIC compilation mode (i.e. myobject.pic.dwo).
+   */
+  public NestedSet<Artifact> getPicDwoArtifacts() {
+    return picDwoArtifacts;
+  }
+}