1 files changed, 33 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/actions/ArtifactPrefixConflictException.java b/src/main/java/com/google/devtools/build/lib/actions/ArtifactPrefixConflictException.java
new file mode 100644
index 0000000000..42ad28568b
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+++ b/src/main/java/com/google/devtools/build/lib/actions/ArtifactPrefixConflictException.java
@@ -0,0 +1,33 @@
+// 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.actions;
+
+import com.google.devtools.build.lib.syntax.Label;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/**
+ * Exception to indicate that one {@link Action} has an output artifact whose path is a prefix of an
+ * output of another action. Since the first path cannot be both a directory and a file, this would
+ * lead to an error if both actions were executed in the same build.
+ */
+public class ArtifactPrefixConflictException extends Exception {
+  public ArtifactPrefixConflictException(PathFragment firstPath, PathFragment secondPath,
+      Label firstOwner, Label secondOwner) {
+    super(String.format(
+        "output path '%s' (belonging to %s) is a prefix of output path '%s' (belonging to %s). "
+        + "These actions cannot be simultaneously present; please rename one of the output files "
+        + "or, as a last resort, run 'blaze clean' and then build just one of them",
+        firstPath, firstOwner, secondPath, secondOwner));
+  }
+}