Issue 4360: SystemError when method has both super() & closure (original) (raw)

Created on 2008-11-20 10:29 by kaizhu, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Messages (8)

msg76093 - (view)

Author: kai zhu (kaizhu)

Date: 2008-11-20 10:29

################################

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 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;

msg76094 - (view)

Author: kai zhu (kaizhu)

Date: 2008-11-20 10:59

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 = '', 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 = '', 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

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

          8           0 LOAD_DEREF               0 (self)
                      3 RETURN_VALUE

msg76095 - (view)

Author: kai zhu (kaizhu)

Date: 2008-11-20 11:10

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 = '', 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 = '', 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

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

          8           0 LOAD_DEREF               0 (self)
                      3 RETURN_VALUE

msg76096 - (view)

Author: kai zhu (kaizhu)

Date: 2008-11-20 11:18

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 = '', 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

msg76103 - (view)

Author: Amaury Forgeot d'Arc (amaury.forgeotdarc) * (Python committer)

Date: 2008-11-20 14:16

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.

msg76104 - (view)

Author: Christian Heimes (christian.heimes) * (Python committer)

Date: 2008-11-20 14:19

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

msg76129 - (view)

Author: Brett Cannon (brett.cannon) * (Python committer)

Date: 2008-11-20 18:57

The patch looks good to me.

msg76133 - (view)

Author: Barry A. Warsaw (barry) * (Python committer)

Date: 2008-11-20 20:02

patch applied; r67299

History

Date

User

Action

Args

2022-04-11 14:56:41

admin

set

github: 48610

2008-11-20 20:02:17

barry

set

status: open -> closed
messages: +

2008-11-20 18:58:05

brett.cannon

set

keywords: - needs review
stage: patch review -> commit review

2008-11-20 18:57:51

brett.cannon

set

nosy: + brett.cannon
messages: +

2008-11-20 14:19:34

christian.heimes

set

nosy: + christian.heimes, barry
messages: +
priority: release blocker
assignee: barry
components: - Build
resolution: accepted
stage: patch review

2008-11-20 14:16:22

amaury.forgeotdarc

set

keywords: + needs review, patch
files: + super-withcell.patch
messages: +
nosy: + amaury.forgeotdarc

2008-11-20 11🔞50

kaizhu

set

messages: +

2008-11-20 11:10:28

kaizhu

set

messages: +

2008-11-20 10:59:15

kaizhu

set

messages: +

2008-11-20 10:29:19

kaizhu

create