in log4j-api-scala_2.10/src/main/scala/org/apache/logging/log4j/scala/LoggerMacro.scala [297:301]
def logMsg(c: LoggerContext)(level: c.Expr[Level], message: c.Expr[Message]) =
c.universe.reify(
if (c.prefix.splice.delegate.isEnabled(level.splice)) {
c.prefix.splice.logMessage(level.splice, null, message.splice, null)
}