Comments based on source document

      <xsl:stylesheet
                  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                  version="2.0">
            <xsl:output  method="xml"
                        indent="yes"
                        omit-xml-declaration="yes"/>

            <xsl:template  match="/aaa">
                  <xxx>
                        <xsl:apply-templates  select="*"/>
                  </xxx>
            </xsl:template>

            <xsl:template  match="*">
                  <yyy>
                        <xsl:comment>
                              <xsl:value-of  select="name()"/>
                              <xsl:text> : </xsl:text>
                              <xsl:value-of  select="position()"/>
                        </xsl:comment>
                  </yyy>
            </xsl:template>

      </xsl:stylesheet>

      <aaa>
            <bbb/>
            <ccc/>
      </aaa>

      <xxx>
            <yyy><!--bbb : 1--></yyy>
            <yyy><!--ccc : 2--></yyy>
      </xxx>