public void execute() throws BuildException {
verifyAttributes();
String out = fOut;
Preprocessor preprocessor = new Preprocessor();
try {
int processed = preprocessor.preprocess(
fInDirFile, fOutDirFile,
fVarMap, fExcludeSet, fTypeMap,
"replace".equals(out), "merge".equals(out));
int modified = preprocessor.getModCount();
log("modified "+modified+" of "+processed+" files");