import gdb

import stx.support

class __instance ( object ):

    """

    Generic object representation. Instance of this class

    also implements gdb pretty-printing API and could therefore

    used as a pretty printer

    """

    def __init__(self, val):

        #stx.support.Decorator.__init__(self, val)

        #object.__setattr__(self, "_klass", None)

        self._obj = val

        self._klass = None

    def display_hint(self):

        '''

        Pretty printer API

        '''

        return None

    def to_string(self):

        '''

        Pretty printer API: Returns a human-readable represenation of the object.

        '''

        return self.display_string()

    def __repr__(self):

        return self.display_string()

    def display_string(self):

        try:

            value = self.display_value()

            klassName = '???'

            klass = self.klass

            if klass == None:

                klassName = '?None?'

            else:

                klassName = klass.name

            if (value == None):

            else:

                return "0x%08x (%s %s)" % ( self.address , klassName , value )

        except:

            return "0x%08x (** err **)" % self.address

    def display_value(self):

        '''

        Return a human-readable represenation of object's value, if sensible.

        FOr instance, for integer or string it may be its respective value

        '''

        return None

    @property

    def address(self):

        '''Return the address of the object in memory'''

        return long(self._obj);

    @property

    def klass(self):

        '''Return this object's class as an __instance value'''

        if (self._klass == None):

            self._klass = create(self._obj['o_class'])

        return self._klass

    @property

    def size(self):

        '''Return size of the objects in slots (excluding header)'''

        # Not really 64bit safe...

        return (self.size_b() - 12) / 4

    def size_b(self):

        '''Return size of the object in bytes, including header'''

    @property

    def flags(self):

        return self._obj['o_flags']

# !!! MAKE SURE they are in sync !!!

BYTEARRAY       = 1

WORDARRAY       = 2

LONGARRAY       = 3

POINTERARRAY    = 4

WKPOINTERARRAY  = 5

FLOATARRAY      = 6

DOUBLEARRAY     = 7

SWORDARRAY      = 8

SLONGARRAY      = 9

LONGLONGARRAY   = 10

SLONGLONGARRAY  = 11

#

# reserved:       13-15

ARRAYMASK       = 0x0F

BEHAVIOR_INSTS  = 0x0010

EXTFUNC_INSTS   = 0x010000

def create(val):

    import stx.gdb.objects.stx_libbasic

    addr = long(val)

    # Here we should care for free/non objects

    # by comparing address agains newspace

    # Well, later :-)

    if (addr == 0):

        return stx.gdb.objects.stx_libbasic.nil

    if ((addr & 1) == 1):

    flags = long(val['o_class']['i_instvars'][1])

    if ((flags & 1) == 1):

        flags = flags >> 1

    else:

        raise Exception("Memory corruption? Class flags are not SmallInteger.")

    if ((flags & BEHAVIOR_INSTS) != 0):

        if (size == 5):

            return stx.gdb.objects.stx_libbasic.Behavior(val)

        if (size == 6):

            return stx.gdb.objects.stx_libbasic.ClassDescription(val)

        if (size >= 17):

        if (size >= 7):

        raise Exception("Funny behaviour-like size (%s)" % size)

    if ((flags & SYMBOL_INSTS) != 0):

        return stx.gdb.objects.stx_libbasic.Symbol(val)

    return __instance(val)