;
    &lt;xs:attribute name="src"      type="xs:string"        use="optional" /&gt;
    &lt;!-- reference to layer --&gt;
    &lt;xs:attribute name="layer"    type="RestrictedString"        use="optional" /&gt;
  &lt;/xs:complexType&gt;

  &lt;!-- Files section within the project section --&gt;
  &lt;xs:complexType name="FilesType"&gt;
    &lt;xs:choice maxOccurs="unbounded"&gt;
      &lt;!-- C-Compiler command-line --&gt;
      &lt;xs:element name="cflags"    type="ToolOptionType" /&gt;
      &lt;!-- C++ C