[webkit-help] How to rebuild webkit after modifying source code?

[wenmhappy]

hi  everybody,
 
      I don`t know how to rebuild webkit after modifying source code such as WebKit-r59711/WebKitTools/GtkLauncher/main.c .  It will take 2 hours to build the whole solution again if  I  run build-webkit directly.  I build webkit with cross-compile. 
 
Anybody help me?
Best regards.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-help/attachments/20110923/71dd7770/attachment.html>