To due the fact that some log-files consists of warnings but neither information about source code file nor information about line number, it would be helpful to link to the log-file and the line number of the warning in the log-file instead.

e.g. @ groovy-script

...
String fileName =

{selected log-file currently parsed}

String lineNumber =

{lineNumber in log-file currently analyzed}

...
return new Warning(fileName, Integer.parseInt(lineNumber), "Dynamic Parser", "xyz Warning", message);

To work around the problem if the parser is analyzing stdout instead of a log-file, either stdout could be linked (if possible) or the problem should be handled in the groovy-script.