<p><code>List of <a href="../build-ref.html#labels">labels</a>;
  optional</code></p>

<p>
Files processed or included by this rule. Generally lists files directly, but
may list rule targets (like <code>filegroup</code> or <code>genrule</code>) to
include their default outputs.
</p>

<p>
Language-specific rules often require that the listed files have particular
file extensions.
</p>
