One or more processors examine source code of one or more software packages that produce output messages and identify, in the source code, one or more call expressions that each represent a logging call. The one or more processors generate a number of search patterns for parsing output messages produced by the one or more software packages, wherein each of the search patterns is based on one or more arguments of a corresponding call expression of the one or more call expressions. The one or more processors further reduce the number of search patterns to be applied to the output messages produced by the one or more software packages to identify log entries among the output messages.