1 

     2           <xsd:attribute name="Compiler" type="xsd:string" use="optional" default="gcc"/>

     3           <xsd:attribute name="CFLAGS" type="xsd:string" use="required"/>

     4           <xsd:attribute name="Linker" type="xsd:string" use="optional" default="ld"/>

     5           <xsd:attribute name="LDFLAGS" type="xsd:string" use="required"/>