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Running Cython fails with 3.14.0a1 - a list attribute gets changed to None #125868
Description
Bug report
Bug description:
To be clear - this issue is just about running the Cython itself (i.e. pure Python code). It is not about compiled extension modules.
To reproduce
- Checkout Cython from git:
https://github.com/cython/cython.git git checkout daed3bce0bf0c6fb9012170cb479f64e8b9532cd(probably not important, but let's make sure we're all definitely starting from the same point).python3.14 cython.py Cython/Compiler/Parsing.py- this runs Cython on one of its own files
You get an output that ends with
File 'ExprNodes.py', line 8643, in analyse_types: TupleNode(Parsing.py:750:34,
is_sequence_constructor = 1,
result_is_used = True,
use_managed_ref = True)
Compiler crash traceback from this point on:
File "/home/dave/Documents/programming/cython2/Cython/Compiler/ExprNodes.py", line 8643, in analyse_types
if len(self.args) == 0:
~~~^^^^^^^^^^^
TypeError: object of type 'NoneType' has no len()To try to debug it some more I add a constructor to TupleNode (in Cython/Compiler/ExprNodes.py at line 8627) with a breakpoint:
def __init__(self, pos, **kw):
if "args" in kw and kw['args'] is None:
breakpoint()
super().__init__(pos, **kw)> <fullpath>/Cython/Compiler/ExprNodes.py(8629)__init__()
-> breakpoint()
(Pdb) print(kw)
{'args': None}
(Pdb) up
> <fullpath>/Cython/Compiler/ExprNodes.py(6123)analyse_types()
-> self.arg_tuple = TupleNode(self.pos, args = self.args)
(Pdb) print(self.args)
[<Cython.Compiler.ExprNodes.NameNode object at 0x7fb636188c80>]
(Pdb) So the the constructor call to TupleNode args is None. But in the function it's being called from it's a list containing a NameNode (which is what I think it should be). That's as far as I've got with debugging.
This has apparently been bisected to #122620 (but not by me).
CPython versions tested on:
3.14
Operating systems tested on:
Linux
Activity
[-]Running Cython fails with 3.14.0a1[/-][+]Running Cython fails with 3.14.0a1 - a list attribute gets changed to `None`[/+]markshannon commentedon Oct 23, 2024
My guess is that #122620 is to blame.
Specifically removing this deopt https://github.com/python/cpython/pull/122620/files#diff-729a985b0cb8b431cb291f1edb561bbbfea22e3f8c262451cd83328a0936a342L2221
If a value is
NULL, then the usual invariants on keys might not apply to that key.Suppose we had a dict
{'a': 'b'}with a table looking like this:I'm not sure how such a table would come into being, but it might be possible through a convoluted sequence of additions and deletions
If a
STORE_ATTR_WITH_HINThadindex=1andkey="a"then it would change the table towhich definitely isn't legal.
leftys commentedon Oct 23, 2024
I tried to compile numpy from @markshannon fix branch and the Cython compilation suddenly worked. Thank you!
GH-125868: Fix STORE_ATTR_WITH_HINT specialization (GH-125876)
scoder commentedon Dec 5, 2024
Closing as the (reported) fix went into 3.14.0a2
pythonGH-125868: Fix STORE_ATTR_WITH_HINT specialization (pythonGH-12…