1 files changed, 117 insertions, 29 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/actions/FilesetOutputSymlink.java b/src/main/java/com/google/devtools/build/lib/actions/FilesetOutputSymlink.java
index 92cf7a975f..f3440398a8 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/FilesetOutputSymlink.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/FilesetOutputSymlink.java
@@ -14,42 +14,51 @@
 package com.google.devtools.build.lib.actions;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.vfs.PathFragment;
+import java.util.Objects;
+import javax.annotation.Nullable;
 
 /** Definition of a symlink in the output tree of a Fileset rule. */
-public final class FilesetOutputSymlink {
+public abstract class FilesetOutputSymlink {
   private static final String STRIPPED_METADATA = "<stripped-for-testing>";
+  private final PathFragment name;
+  private final PathFragment target;
+  private final String metadata;
+
+  FilesetOutputSymlink(PathFragment name, PathFragment target, String metadata) {
+    this.name = Preconditions.checkNotNull(name);
+    this.target = Preconditions.checkNotNull(target);
+    this.metadata = Preconditions.checkNotNull(metadata);
+  }
 
   /** Final name of the symlink relative to the Fileset's output directory. */
-  public final PathFragment name;
+  public PathFragment getName() {
+    return name;
+  }
 
-  /** Target of the symlink. Depending on FilesetEntry.symlinks it may be relative or absolute. */
-  public final PathFragment target;
+  /**
+   * Target of the symlink. This may be relative to the target's location if the target itself is a
+   * relative symlink. We can override it by using FilesetEntry.symlinks = 'dereference'.
+   */
+  public PathFragment getTargetPath() {
+    return target;
+  }
 
   /** Opaque metadata about the link and its target; should change if either of them changes. */
-  public final String metadata;
-
-  @VisibleForTesting
-  public FilesetOutputSymlink(PathFragment name, PathFragment target) {
-    this.name = name;
-    this.target = target;
-    this.metadata = STRIPPED_METADATA;
+  public String getMetadata() {
+    return metadata;
   }
 
+  /** true if the target is a generated artifact */
+  public abstract boolean isGeneratedTarget();
+
   /**
-   * @param name relative path under the Fileset's output directory, including FilesetEntry.destdir
-   *        with and FilesetEntry.strip_prefix applied (if applicable)
-   * @param target relative or absolute value of the link
-   * @param metadata opaque metadata about the link and its target; should change if either the link
-   *        or its target changes
+   * returns the target artifact if it's generated {@link #isGeneratedTarget() == true}, or null
+   * otherwise.
    */
-  public FilesetOutputSymlink(PathFragment name, PathFragment target, String metadata) {
-    this.name = Preconditions.checkNotNull(name);
-    this.target = Preconditions.checkNotNull(target);
-    this.metadata = Preconditions.checkNotNull(metadata);
-  }
+  @Nullable
+  public abstract FileArtifactValue getTargetArtifactValue();
 
   @Override
   public boolean equals(Object obj) {
@@ -60,22 +69,101 @@ public final class FilesetOutputSymlink {
       return false;
     }
     FilesetOutputSymlink o = (FilesetOutputSymlink) obj;
-    return name.equals(o.name) && target.equals(o.target) && metadata.equals(o.metadata);
+    return getName().equals(o.getName())
+        && getTargetPath().equals(o.getTargetPath())
+        && getMetadata().equals(o.getMetadata())
+        && isGeneratedTarget() == o.isGeneratedTarget()
+        && Objects.equals(getTargetArtifactValue(), o.getTargetArtifactValue());
   }
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(name, target, metadata);
+    return Objects.hash(
+        getName(), getTargetPath(), getMetadata(), isGeneratedTarget(), getTargetArtifactValue());
   }
 
   @Override
   public String toString() {
-    if (metadata.equals(STRIPPED_METADATA)) {
-      return String.format("FilesetOutputSymlink(%s -> %s)",
-          name.getPathString(), target.getPathString());
+    if (getMetadata().equals(STRIPPED_METADATA)) {
+      return String.format(
+          "FilesetOutputSymlink(%s -> %s)",
+          getName().getPathString(), getTargetPath().getPathString());
     } else {
-      return String.format("FilesetOutputSymlink(%s -> %s | metadata=%s)",
-          name.getPathString(), target.getPathString(), metadata);
+      return String.format(
+          "FilesetOutputSymlink(%s -> %s | metadata=%s)",
+          getName().getPathString(), getTargetPath().getPathString(), getMetadata());
+    }
+  }
+
+  @VisibleForTesting
+  public static FilesetOutputSymlink createForTesting(PathFragment name, PathFragment target) {
+    return new SourceOutputSymlink(name, target, STRIPPED_METADATA);
+  }
+
+  /**
+   * @param name relative path under the Fileset's output directory, including FilesetEntry.destdir
+   *     with and FilesetEntry.strip_prefix applied (if applicable)
+   * @param target relative or absolute value of the link
+   * @param metadata opaque metadata about the link and its target; should change if either the link
+   *     or its target changes
+   */
+  public static FilesetOutputSymlink createForSourceTarget(
+      PathFragment name, PathFragment target, String metadata) {
+    return new SourceOutputSymlink(name, target, metadata);
+  }
+
+  /**
+   * @param name relative path under the Fileset's output directory, including FilesetEntry.destdir
+   *     with and FilesetEntry.strip_prefix applied (if applicable)
+   * @param target relative or absolute value of the link
+   * @param metadata opaque metadata about the link and its target; should change if either the link
+   *     or its target changes
+   * @param fileArtifactValue the {@link FileArtifactValue} corresponding to the target.
+   */
+  public static FilesetOutputSymlink createForDerivedTarget(
+      PathFragment name,
+      PathFragment target,
+      String metadata,
+      @Nullable FileArtifactValue fileArtifactValue) {
+    return new DerivedOutputSymlink(name, target, metadata, fileArtifactValue);
+  }
+
+  private static class DerivedOutputSymlink extends FilesetOutputSymlink {
+    private final FileArtifactValue fileArtifactValue;
+
+    DerivedOutputSymlink(
+        PathFragment name,
+        PathFragment target,
+        String metadata,
+        FileArtifactValue fileArtifactValue) {
+      super(name, target, metadata);
+      this.fileArtifactValue = fileArtifactValue;
+    }
+
+    @Override
+    public boolean isGeneratedTarget() {
+      return true;
+    }
+
+    @Override
+    public FileArtifactValue getTargetArtifactValue() {
+      return fileArtifactValue;
+    }
+  }
+
+  private static class SourceOutputSymlink extends FilesetOutputSymlink {
+    SourceOutputSymlink(PathFragment name, PathFragment target, String metadata) {
+      super(name, target, metadata);
+    }
+
+    @Override
+    public boolean isGeneratedTarget() {
+      return false;
+    }
+
+    @Override
+    public FileArtifactValue getTargetArtifactValue() {
+      return null;
     }
   }
 }