SystemError when method has both super() & closure #48610

kaizhu · 2008-11-20T10:29:19Z

BPO	4360
Nosy	@warsaw, @brettcannon, @amauryfa, @tiran
Files	super-withcell.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/warsaw'
closed_at = <Date 2008-11-20.20:02:17.826>
created_at = <Date 2008-11-20.10:29:19.374>
labels = ['interpreter-core', 'type-bug', 'release-blocker']
title = 'SystemError when method has both super() & closure'
updated_at = <Date 2008-11-20.20:02:17.825>
user = 'https://bugs.python.org/kaizhu'

bugs.python.org fields:

activity = <Date 2008-11-20.20:02:17.825>
actor = 'barry'
assignee = 'barry'
closed = True
closed_date = <Date 2008-11-20.20:02:17.826>
closer = 'barry'
components = ['Interpreter Core']
creation = <Date 2008-11-20.10:29:19.374>
creator = 'kaizhu'
dependencies = []
files = ['12070']
hgrepos = []
issue_num = 4360
keywords = ['patch']
message_count = 8.0
messages = ['76093', '76094', '76095', '76096', '76103', '76104', '76129', '76133']
nosy_count = 5.0
nosy_names = ['barry', 'brett.cannon', 'amaury.forgeotdarc', 'christian.heimes', 'kaizhu']
pr_nums = []
priority = 'release blocker'
resolution = 'accepted'
stage = 'commit review'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue4360'
versions = ['Python 3.0']

kaizhu · 2008-11-20T10:29:18Z

################################
# super_closure.py
class A(object):
  def foo(self):
    return super()
    # remove the closure below
    # & SystemError goes away ???
    lambda: self
A().foo()
################################

when run on 3.0rc1 & 3.0rc2:

hpc-login2 3 ~/work/py3to2: python3.0 super_closure.py
Traceback (most recent call last):
  File "super_closure.py", line 9, in <module>
    A().foo()
  File "super_closure.py", line 5, in foo
    return super()
SystemError: super(): __class__ is not a type (A)

SystemError seems to b raised from typeobject.c (line6155):

static int
super_init(PyObject *self, PyObject *args, PyObject *kwds)
{...
        if (!PyType_Check(type)) {
            PyErr_Format(PyExc_SystemError,
              "super(): __class__ is not a type (%s)",
              Py_TYPE(type)->tp_name);
            return -1;
        }
        break;

kaizhu · 2008-11-20T10:59:15Z

here's a printout of bytecode from script

>>>
>>> s = open("super_closure.py").read()
>>> c = compile(s, "super_closure.py", "exec")
>>> t = py3to2.codetree(c)
>>> print( t )
codetree(
co_argcount =     0,
co_cellvars =     (),
co_code =        
b'Gd\x00\x00\x84\x00\x00d\x01\x00e\x00\x00\x83\x03\x00Z\x01\x00e\x01\x00\x83\x00\x00j\x02\x00\x83\x00\x00\x01d\x02\x00S',
co_filename =     'super_closure.py',
co_firstlineno =  3,
co_flags =        64,
co_freevars =     (),
co_kwonlyargcount =0,
co_lnotab =       b'\x13\x06',
co_name =         '<module>',
co_names =        ('object', 'A', 'foo'),
co_nlocals =      0,
co_stacksize =    4,
co_varnames =     (),
depth =           0,
co_consts = (
 codetree(
 co_argcount =     1,
 co_cellvars =     ('__class__',),
 co_code =        
b'|\x00\x00Ee\x00\x00Z\x01\x00\x87\x00\x00f\x01\x00d\x00\x00\x86\x00\x00Z\x02\x00\x87\x00\x00S',
 co_filename =     'super_closure.py',
 co_firstlineno =  3,
 co_flags =        2,
 co_freevars =     (),
 co_kwonlyargcount =0,
 co_lnotab =       b'\n\x01',
 co_name =         'A',
 co_names =        ('__name__', '__module__', 'foo'),
 co_nlocals =      1,
 co_stacksize =    2,
 co_varnames =     ('__locals__',),
 depth =           1,
 co_consts = (
  codetree(
  co_argcount =     1,
  co_cellvars =     ('self',),
  co_code =        
b't\x00\x00\x83\x00\x00S\x87\x00\x00f\x01\x00d\x01\x00\x86\x00\x00\x01',
  co_filename =     'super_closure.py',
  co_firstlineno =  4,
  co_flags =        3,
  co_freevars =     ('__class__',),
  co_kwonlyargcount =0,
  co_lnotab =       b'\x00\x01\x07\x03',
  co_name =         'foo',
  co_names =        ('super',),
  co_nlocals =      1,
  co_stacksize =    2,
  co_varnames =     ('self',),
  depth =           2,
  co_consts = (
   None,
   codetree(
   co_argcount =     0,
   co_cellvars =     (),
   co_code =         b'\x88\x00\x00S',
   co_filename =     'super_closure.py',
   co_firstlineno =  8,
   co_flags =        19,
   co_freevars =     ('self',),
   co_kwonlyargcount =0,
   co_lnotab =       b'',
   co_name =         '<lambda>',
   co_names =        (),
   co_nlocals =      0,
   co_stacksize =    1,
   co_varnames =     (),
   depth =           3,
   co_consts = (
    )),
   )),
  )),
 A,
 None,
 ))
>>>

and disassembly:

>>>
>>> print( t.dis() )
  3           0 LOAD_BUILD_CLASS
              1 LOAD_CONST               0 (<code object A at
0x2a987af9b0, file "super_closure.py", line 3>)
              4 MAKE_FUNCTION            0
              7 LOAD_CONST               1 ('A')
             10 LOAD_NAME                0 (object)
             13 CALL_FUNCTION            3
             16 STORE_NAME               1 (A)

9 19 LOAD_NAME 1 (A)
22 CALL_FUNCTION 0
25 LOAD_ATTR 2 (foo)
28 CALL_FUNCTION 0
31 POP_TOP
32 LOAD_CONST 2 (None)
35 RETURN_VALUE

  3           0 LOAD_FAST                0 (__locals__)
              3 STORE_LOCALS
              4 LOAD_NAME                0 (__name__)
              7 STORE_NAME               1 (__module__)

  4          10 LOAD_CLOSURE             0 (__class__)
             13 BUILD_TUPLE              1
             16 LOAD_CONST               0 (\<code object foo at

0x2a987afd30, file "super_closure.py", line 4>)
19 MAKE_CLOSURE 0
22 STORE_NAME 2 (foo)
25 LOAD_CLOSURE 0 (class)
28 RETURN_VALUE

      5           0 LOAD_GLOBAL              0 (super)
                  3 CALL_FUNCTION            0
                  6 RETURN_VALUE

      8           7 LOAD_CLOSURE             0 (self)
                 10 BUILD_TUPLE              1
                 13 LOAD_CONST               1 (\<code object

<lambda> at 0x2a984c0530, file "super_closure.py", line 8>)
16 MAKE_CLOSURE 0
19 POP_TOP

          8           0 LOAD_DEREF               0 (self)
                      3 RETURN_VALUE

>>

kaizhu · 2008-11-20T11:10:28Z

same thing, except w/ closure commented out (& everything is happy)

################################
# super_ok.py
class A(object):
  def foo(self):
    return super()
    # comment the closure below
    # & SystemError goes away
    # lambda: self
A().foo()
################################

>>>
>>> s = open("super_ok.py").read()
>>> c = compile(s, "super_ok.py", "exec")
>>> t = py3to2.codetree(t)
>>> print( t )
codetree(
co_argcount =     0,
co_cellvars =     (),
co_code =        
b'Gd\x00\x00\x84\x00\x00d\x01\x00e\x00\x00\x83\x03\x00Z\x01\x00e\x01\x00\x83\x00\x00j\x02\x00\x83\x00\x00\x01d\x02\x00S',
co_filename =     'super_closure.py',
co_firstlineno =  3,
co_flags =        64,
co_freevars =     (),
co_kwonlyargcount =0,
co_lnotab =       b'\x13\x06',
co_name =         '<module>',
co_names =        ('object', 'A', 'foo'),
co_nlocals =      0,
co_stacksize =    4,
co_varnames =     (),
depth =           0,
co_consts = (
 codetree(
 co_argcount =     1,
 co_cellvars =     ('__class__',),
 co_code =        
b'|\x00\x00Ee\x00\x00Z\x01\x00\x87\x00\x00f\x01\x00d\x00\x00\x86\x00\x00Z\x02\x00\x87\x00\x00S',
 co_filename =     'super_closure.py',
 co_firstlineno =  3,
 co_flags =        2,
 co_freevars =     (),
 co_kwonlyargcount =0,
 co_lnotab =       b'\n\x01',
 co_name =         'A',
 co_names =        ('__name__', '__module__', 'foo'),
 co_nlocals =      1,
 co_stacksize =    2,
 co_varnames =     ('__locals__',),
 depth =           1,
 co_consts = (
  codetree(
  co_argcount =     1,
  co_cellvars =     ('self',),
  co_code =        
b't\x00\x00\x83\x00\x00S\x87\x00\x00f\x01\x00d\x01\x00\x86\x00\x00\x01',
  co_filename =     'super_closure.py',
  co_firstlineno =  4,
  co_flags =        3,
  co_freevars =     ('__class__',),
  co_kwonlyargcount =0,
  co_lnotab =       b'\x00\x01\x07\x03',
  co_name =         'foo',
  co_names =        ('super',),
  co_nlocals =      1,
  co_stacksize =    2,
  co_varnames =     ('self',),
  depth =           2,
  co_consts = (
   None,
   codetree(
   co_argcount =     0,
   co_cellvars =     (),
   co_code =         b'\x88\x00\x00S',
   co_filename =     'super_closure.py',
   co_firstlineno =  8,
   co_flags =        19,
   co_freevars =     ('self',),
   co_kwonlyargcount =0,
   co_lnotab =       b'',
   co_name =         '<lambda>',
   co_names =        (),
   co_nlocals =      0,
   co_stacksize =    1,
   co_varnames =     (),
   depth =           3,
   co_consts = (
    )),
   )),
  )),
 A,
 None,
 ))
>>>
>>> print( t.dis() )
  3           0 LOAD_BUILD_CLASS
              1 LOAD_CONST               0 (<code object A at
0x2a987af2b0, file "super_closure.py", line 3>)
              4 MAKE_FUNCTION            0
              7 LOAD_CONST               1 ('A')
             10 LOAD_NAME                0 (object)
             13 CALL_FUNCTION            3
             16 STORE_NAME               1 (A)

9 19 LOAD_NAME 1 (A)
22 CALL_FUNCTION 0
25 LOAD_ATTR 2 (foo)
28 CALL_FUNCTION 0
31 POP_TOP
32 LOAD_CONST 2 (None)
35 RETURN_VALUE

  3           0 LOAD_FAST                0 (__locals__)
              3 STORE_LOCALS
              4 LOAD_NAME                0 (__name__)
              7 STORE_NAME               1 (__module__)

  4          10 LOAD_CLOSURE             0 (__class__)
             13 BUILD_TUPLE              1
             16 LOAD_CONST               0 (\<code object foo at

0x2a987af4b0, file "super_closure.py", line 4>)
19 MAKE_CLOSURE 0
22 STORE_NAME 2 (foo)
25 LOAD_CLOSURE 0 (class)
28 RETURN_VALUE

      5           0 LOAD_GLOBAL              0 (super)
                  3 CALL_FUNCTION            0
                  6 RETURN_VALUE

      8           7 LOAD_CLOSURE             0 (self)
                 10 BUILD_TUPLE              1
                 13 LOAD_CONST               1 (\<code object

<lambda> at 0x2a987af5b0, file "super_closure.py", line 8>)
16 MAKE_CLOSURE 0
19 POP_TOP

          8           0 LOAD_DEREF               0 (self)
                      3 RETURN_VALUE

>>

kaizhu · 2008-11-20T11:18:50Z

oops, sorry reprinted the same code ^^;;; ignore previous post, & use
this: (sorry again for mucking up this page)

################################
# super_ok.py
class A(object):
  def foo(self):
    return super()
    # comment the closure below
    # & SystemError goes away
    # lambda: self
A().foo()
################################

>>> s = open("super_ok.py").read(); c = compile(s, "super_ok.py",
"exec"); t = py3to2.codetree(c)
>>> print( t )
codetree(
co_argcount =     0,
co_cellvars =     (),
co_code =        
b'Gd\x00\x00\x84\x00\x00d\x01\x00e\x00\x00\x83\x03\x00Z\x01\x00e\x01\x00\x83\x00\x00j\x02\x00\x83\x00\x00\x01d\x02\x00S',
co_filename =     'super_ok.py',
co_firstlineno =  3,
co_flags =        64,
co_freevars =     (),
co_kwonlyargcount =0,
co_lnotab =       b'\x13\x06',
co_name =         '<module>',
co_names =        ('object', 'A', 'foo'),
co_nlocals =      0,
co_stacksize =    4,
co_varnames =     (),
depth =           0,
co_consts = (
 codetree(
 co_argcount =     1,
 co_cellvars =     ('__class__',),
 co_code =        
b'|\x00\x00Ee\x00\x00Z\x01\x00\x87\x00\x00f\x01\x00d\x00\x00\x86\x00\x00Z\x02\x00\x87\x00\x00S',
 co_filename =     'super_ok.py',
 co_firstlineno =  3,
 co_flags =        2,
 co_freevars =     (),
 co_kwonlyargcount =0,
 co_lnotab =       b'\n\x01',
 co_name =         'A',
 co_names =        ('__name__', '__module__', 'foo'),
 co_nlocals =      1,
 co_stacksize =    2,
 co_varnames =     ('__locals__',),
 depth =           1,
 co_consts = (
  codetree(
  co_argcount =     1,
  co_cellvars =     (),
  co_code =         b't\x00\x00\x83\x00\x00S',
  co_filename =     'super_ok.py',
  co_firstlineno =  4,
  co_flags =        3,
  co_freevars =     ('__class__',),
  co_kwonlyargcount =0,
  co_lnotab =       b'\x00\x01',
  co_name =         'foo',
  co_names =        ('super',),
  co_nlocals =      1,
  co_stacksize =    1,
  co_varnames =     ('self',),
  depth =           2,
  co_consts = (
   None,
   )),
  )),
 A,
 None,
 ))
>>> print( t.dis() )
  3           0 LOAD_BUILD_CLASS
              1 LOAD_CONST               0 (<code object A at
0x2a987afd30, file "super_ok.py", line 3>)
              4 MAKE_FUNCTION            0
              7 LOAD_CONST               1 ('A')
             10 LOAD_NAME                0 (object)
             13 CALL_FUNCTION            3
             16 STORE_NAME               1 (A)

9 19 LOAD_NAME 1 (A)
22 CALL_FUNCTION 0
25 LOAD_ATTR 2 (foo)
28 CALL_FUNCTION 0
31 POP_TOP
32 LOAD_CONST 2 (None)
35 RETURN_VALUE

  3           0 LOAD_FAST                0 (__locals__)
              3 STORE_LOCALS
              4 LOAD_NAME                0 (__name__)
              7 STORE_NAME               1 (__module__)

  4          10 LOAD_CLOSURE             0 (__class__)
             13 BUILD_TUPLE              1
             16 LOAD_CONST               0 (\<code object foo at

0x2a984c0530, file "super_ok.py", line 4>)
19 MAKE_CLOSURE 0
22 STORE_NAME 2 (foo)
25 LOAD_CLOSURE 0 (class)
28 RETURN_VALUE

      5           0 LOAD_GLOBAL              0 (super)
                  3 CALL_FUNCTION            0
                  6 RETURN_VALUE

>>

amauryfa · 2008-11-20T14:16:21Z

In a running frame, f->f_localplus is a vector composed of:

the values of the local variables
the cells containing variables used in a nested closure.
the values of free variables defined in a outer scope.

super() needs to access the free var containing the enclosing class
object, but forgets to account for the number of cells...

The attached patch corrects the problem.

tiran · 2008-11-20T14:19:35Z

Yet another release blocker for Barry. Good work, Amaury.

brettcannon · 2008-11-20T18:57:51Z

The patch looks good to me.

warsaw · 2008-11-20T20:02:18Z

patch applied; r67299

kaizhu mannequin added build The build process and cross-build interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error labels Nov 20, 2008

tiran added release-blocker and removed build The build process and cross-build labels Nov 20, 2008

tiran assigned warsaw Nov 20, 2008

warsaw closed this as completed Nov 20, 2008

ezio-melotti transferred this issue from another repository Apr 10, 2022

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SystemError when method has both super() & closure #48610

SystemError when method has both super() & closure #48610

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

amauryfa commented Nov 20, 2008

tiran commented Nov 20, 2008

brettcannon commented Nov 20, 2008

warsaw commented Nov 20, 2008

SystemError when method has both super() & closure #48610

SystemError when method has both super() & closure #48610

Comments

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

kaizhu mannequin commented Nov 20, 2008

amauryfa commented Nov 20, 2008

tiran commented Nov 20, 2008

brettcannon commented Nov 20, 2008

warsaw commented Nov 20, 2008