lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/data/res/values/negative_margins.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="positive">16dp</dimen>
    <dimen name="negative">-16dp</dimen>

    <style name="MyStyle">
        <item name="android:layout_margin">5dp</item> <!-- OK -->
        <item name="android:layout_marginLeft">@dimen/positive</item> <!-- OK -->
        <item name="android:layout_marginTop">@dimen/negative</item> <!-- WARNING -->
        <item name="android:layout_marginBottom">-5dp</item> <!-- WARNING -->
    </style>
</resources>