String path = file.getAbsolutePath();
String name = path.substring(prefixLength);
DirectiveBasedJavascriptGroup group = new DirectiveBasedJavascriptGroup(name,
impl_f, path, DIRECTIVES, EnumSet.of(JavascriptGeneratorMode.DOC));
group.parse();
group.generate(dest_f, false);
} catch(Throwable t) {
System.err.println("Failed to parse "+file.getPath());
t.printStackTrace();
System.exit(1);
}