Figure out stackdepth too small in compiler and fix root cause #15
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carljm
referenced
this issue
Apr 8, 2022
Inada Naoki noticed that Python crashed
when using the following command-line:
./python -m py_compile checker.py
Valgrind diagnosed the error. stackdepth()
in compile.c measures how many basic blocks
there are, then creates a "stack" with enough
space for... something? Then walks the graph
of blocks and measures the total stack depth,
using "stack" as some sort of context stack.
The problem: in certain circumstances,
"stack" was *way* smaller than it should have
been. The worst observed one: we thought we
needed 66 slots, but we needed over 150 (!!!).
I "fixed" it by making it realloc() "stack"
in case it's too small. I don't know why
this should be necessary. Hopefully someone
more expert with compile.c can take a look.
|
With 63b415c reverted, |
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63b415c papers over the issue, but we should figure out why it's too small in the first place and fix the root cause.
So far I haven't been able to find a repro case, not sure where the
checker.pymentioned in the commit message comes from; there's nochecker.pyin the CPython repo.The text was updated successfully, but these errors were encountered: