user/src/com/google/gwt/logging/LogImpl.gwt.xml

<module>
  <inherits name="com.google.gwt.core.Core"/>
  <source path="impl" />

  <define-property name="gwt.logging.enabled" values="TRUE, FALSE, SEVERE, WARNING" />
  <set-property name="gwt.logging.enabled" value="FALSE"/>
  <set-property name="gwt.logging.enabled" value="TRUE">
    <when-property-is name="jre.debugMode" value="ENABLED"/>
  </set-property>

  <!-- Forward gwt.logging.enabled to jre.logging.logLevel -->
  <set-property name="jre.logging.logLevel" value="ALL">
    <when-property-is name="gwt.logging.enabled" value="TRUE"/>
  </set-property>
  <set-property name="jre.logging.logLevel" value="SEVERE">
    <when-property-is name="gwt.logging.enabled" value="SEVERE"/>
  </set-property>
  <set-property name="jre.logging.logLevel" value="WARNING">
    <when-property-is name="gwt.logging.enabled" value="WARNING"/>
  </set-property>
  <set-property name="jre.logging.logLevel" value="OFF">
    <when-property-is name="gwt.logging.enabled" value="FALSE"/>
  </set-property>


  <define-property name="gwt.logging.simpleConsoleHandler" values="ENABLED, DISABLED" />
  <set-property name="gwt.logging.simpleConsoleHandler" value="ENABLED"/>

  <!-- Forward gwt.logging.simpleConsoleHandler to jre.logging.simpleConsoleHandler -->
  <set-property name="jre.logging.simpleConsoleHandler" value="DISABLED">
    <when-property-is name="gwt.logging.simpleConsoleHandler" value="DISABLED"/>
  </set-property>

</module>