PyPy SIGSEGV on small program

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In Heptapod by @BarrensZeppelin on Nov 19, 2023, 18:27

Originally reported here: https://codeforces.com/blog/entry/122455

PyPy crashes with a segmentation fault when it runs the following program:

def main():
    k = 15
    m = 3
    
    for a in range(k + 1):
        for b in range(k + 1):
            for c in range(min(m, k) + 1):
                for d in range(min(m, k) + 1):
                    continue
    return

t = 1
for _ in range(t):
    main() 

PyPy version:

Python 3.10.13 (f1607341da97ff5a1e93430b6e8c4af0ad1aa019, Oct 02 2023, 19:25:21)
[PyPy 7.3.13 with GCC 13.2.1 20230801]

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In Heptapod by @bjorn-martinsson on Nov 19, 2023, 20:49

Here is a small example with the same issue

def f():
    m = 3
    for a in range(100):
        for b in range(m + 1):
            for c in range(m + 1):
                pass
f() 

Can also confirm it crashes for me on Windows using

Python 3.10.12 (af44d0b8114cb82c40a07bb9ee9c1ca8a1b3688c, Jun 15 2023, 15:42:22)
[PyPy 7.3.12 with MSC v.1929 64 bit (AMD64)]

but it does not segfault with

Python 3.7.10 (51efa818fd9b, Apr 04 2021, 12:09:32)
[PyPy 7.3.4 with MSC v.1927 64 bit (AMD64)]

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In Heptapod by @arigo on Nov 19, 2023, 23:49

I had a quick look in gdb: it's a clean NULL pointer dereference in
ExtendedShortPreambleBuilder_add_preamble_op. In the operation doing len(something.label_args), this field label_args is None.

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In Heptapod by @Yawn_Sean on Nov 20, 2023, 04:03

Thanks for your help (I'm the one who posted that codeforces blog)! And I finally logged into this website. Actually, I discovered the issue through this submission: https://atcoder.jp/contests/arc168/submissions/47760691

And using this version of Pypy, the code also segfaults:

Python 3.9.16 (feeb267ead3e6771d3f2f49b83e1894839f64fb7, Dec 29 2022, 14:45:38)
[PyPy 7.3.11 with MSC v.1929 64 bit (AMD64)] on win32

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In Heptapod by @cfbolz on Nov 28, 2023, 17:32

mentioned in commit 5e21dfecc2d4320580bfe3a19f37c0e5a214d356

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In Heptapod by @cfbolz on Nov 28, 2023, 17:32

mentioned in commit cb4b136ee2310a63036994ad726cab6d077422d3

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In Heptapod by @cfbolz on Nov 28, 2023, 17:33

the crash is fixed now. tomorrow's 3.9 nightly should contain the fix.

[cfbolz]

this is fixed