import gdb
import gdb.printing

class Lisp_Object_Printer:
    def __init__(self, val):
        self.val = val

    def to_string(self):
        return str (self.val["i"]) + "L"

def build_pretty_printer ():
    pp = gdb.printing.RegexpCollectionPrettyPrinter ("Emacs")
    pp.add_printer ('Lisp_Object', '^Lisp_Object$', Lisp_Object_Printer)
    return pp

gdb.printing.register_pretty_printer (gdb.current_objfile (),
                                      build_pretty_printer (),
                                      1)