A plea for a bugfix was Re: [Pyrex] Unlucky fellow needs help (pyrex crashes)

[Helmut Jarausch]

It would be very kind if someone could help me
in fixing Pyrex 0.9.3 (.1)

I could benefit quite a lot from subclassing.
But my base class __new__ takes only self as
argument whereas my derived classes take more
parameters.
So, I again stumbled on the bug below.
I've never looked at Pyrex source before
but I probably need to.
Can anybody help a bit where this bug
can be fixed?

The problem has nothing to do with a forward
declaration as in the original example
Just try

cdef class B:
  cdef int Seen
  def __new__(self):
    self.Seen=17

cdef class D(B):
  def __new__(self,int DS):
    self.Seen= DS

  def showme(self):
    print self.Seen

# ===================================================

# from CES import D
# X=D(13)
# X.showme()


Is there a debug mode for Pyrex itself?

Many thanks,
Helmut.


On 23 Feb, Lenard Lindstrom wrote:
> On 23 Feb 2006 at 17:25, Greg Ewing wrote:
> 
>> Helmut Jarausch wrote:
>> 
>> > cdef class ITNO    # forward declaration
>> > 
>> > cdef class ITNO_List(ITNO):
>> >   cdef int cnt
>> >   cdef int From
>> >   cdef int To
>> 
>> This is an error, since I never intended to support
>> using a class as a base class prior to its definition.
>> It's a bug that Pyrex crashes instead of reporting the
>> error, though.
>> 
>> > Variant II is accepted by pyrexc but
>> > gives a segment fault while running the loop
>> > 
>> > cdef class ITNO             # forward declaration
>> > cdef class ITNO_List(ITNO)  # forward declaration
>> 
>> I'm not sure whether this should be allowed or not.
>> I'll look into these.
>> 
>> Thanks,
>> 
> The problem is that the ITNO  __new__ takes no arguments while the 
> ITNO_List  __new__ takes two. When creating a new ITNO_List instance  
> the INTO __new__ function is called with the wrong number of 
> arguments and raises an exception.
> 
> The segment fault is because Pyrex is not checking if ITNO.__new__ 
> has raised an exception so calls INTO_List.__new__ with an invalid 
> object. Pyrex generated tp_new slot functions do not test if the 
> pointer to the newly allocated object is NULL.
> 
> Lenard Lindstrom
> <len-l at telus.net>
> 
> 
> _______________________________________________
> Pyrex mailing list
> Pyrex at lists.copyleft.no
> http://lists.copyleft.no/mailman/listinfo/pyrex
> 

-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany