[Python-Dev] Disabling string interning for null and single-char causes segfaults (original) (raw)

Stefan Bucur stefan.bucur at gmail.com
Fri Mar 1 16:24:42 CET 2013

Hi,

I'm working on an automated bug finding tool that I'm trying to apply on the Python interpreter code (version 2.7.3). Because of early prototype limitations, I needed to disable string interning in stringobject.c. More precisely, I modified the PyString_FromStringAndSize and PyString_FromString to no longer check for the null and single-char cases, and create instead a new string every time (I can send the patch if needed).

However, after applying this modification, when running "make test" I get a segfault in the test___all__ test case.

Before digging deeper into the issue, I wanted to ask here if there are any implicit assumptions about string identity and interning throughout the interpreter implementation. For instance, are two single-char strings having the same content supposed to be identical objects?

I'm assuming that it's either this, or some refcount bug in the interpreter that manifests only when certain strings are no longer interned and thus have a higher chance to get low refcount values.

Thanks a lot, Stefan Bucur -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20130301/c86e3b52/attachment.html>

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