1 files changed, 12 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
index b4ded0ef29..851aaf25a9 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
@@ -408,6 +408,18 @@ public final class CcCommon {
         ruleContext.attributeError("includes",
             "Path references a path above the execution root.");
       }
+      if (!includesPath.startsWith(packageFragment)) {
+        ruleContext.attributeWarning(
+            "includes",
+            "'"
+                + includesAttr
+                + "' resolves to '"
+                + includesPath
+                + "' not below the relative path of its package '"
+                + packageFragment
+                + "'. This will be an error in the future");
+        // TODO(janakr): Add a link to a page explaining the problem and fixes?
+      }
       result.add(includesPath);
       result.add(ruleContext.getConfiguration().getGenfilesFragment().getRelative(includesPath));
     }