1 files changed, 38 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedFunction.java
new file mode 100644
index 0000000000..8254987344
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedFunction.java
@@ -0,0 +1,38 @@
+// 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.skyframe;
+
+import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunctionException;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+
+/**
+ * Builder for {@link PrecomputedValue}s.
+ *
+ * <p>Always throws an error, because the values aren't computed inside the skyframe framework.
+ */
+public class PrecomputedFunction implements SkyFunction {
+
+  @Override
+  public SkyValue compute(SkyKey skyKey, Environment env) throws SkyFunctionException,
+      InterruptedException {
+    throw new IllegalStateException(skyKey + " not set");
+  }
+
+  @Override
+  public String extractTag(SkyKey skyKey) {
+    return null;
+  }
+}