[Python-bugs-list] [ python-Bugs-443866 ] Evaluating func_code causing core dump

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Bugs item #443866, was opened at 2001-07-23 17:48
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Category: Python Interpreter Core
Group: Python 2.2
>Status: Closed
Resolution: Later
Priority: 3
Submitted By: Jonathan Hogg (jhogg)
Assigned to: Jeremy Hylton (jhylton)
Summary: Evaluating func_code causing core dump

Initial Comment:
Python 2.2a1 (#1, Jul 19 2001, 18:18:51)
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-81)] on 
linux2

The intepreter dies hard if you directly evaluate the 
func_code of a function that has a closure. E.g.:

-----
def func1():
    return lambda: 4 + y

f = func1()
print "Ugly test 1:", eval( f.func_code, {'y': 38} )


def func2(x):
    return lambda: x + y

f = func2(4)
print "Ugly test 2:", eval( f.func_code, {'y': 38} )
-----

The second eval will cause a core dump on UNIX. The 
offending code is in PyEval_EvalCodeEx() of ceval.c 
line 2466. This loop attempts to match free vars 
against the closure, but the closure is NULL if the 
function is called with eval.

I know this is very broken usage of the interpreter, 
but it should die more cleanly than a core dump ;-)

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>Comment By: Jeremy Hylton (jhylton)
Date: 2002-07-11 18:11

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Added feature request to pep 42.


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Comment By: Skip Montanaro (montanaro)
Date: 2002-03-10 01:44

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just a reminder that this appears to be fixed -skip


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Comment By: Guido van Rossum (gvanrossum)
Date: 2001-12-12 05:29

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Jeremy, since you claimed this to be fixed, is there a
reason to keep this bug report open? If you want a feature,
please open a (new, please!) feature request.

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Comment By: Jeremy Hylton (jhylton)
Date: 2001-07-30 21:53

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It might be useful to extend eval() with a means to specify
bindings from free variables.  It's not at all clear how to
do this under the current implementation, which refers to
free variables using integer indexes assigned at compile
time.


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Comment By: Jeremy Hylton (jhylton)
Date: 2001-07-30 21:51

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Fixed in rev 2.219 of bltinmodule.c


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Comment By: Tim Peters (tim_one)
Date: 2001-07-24 22:35

Message:
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Assigned to Jeremy in the hopes this will speed his return 
to us <wink>.

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