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GeezerVison is showing github.com — GH-131498: Allow 'peek' variables to be modified by markshannon · Pull Request #132506 · python/cpython

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@markshannon

@markshannon markshannon commented Apr 14, 2025 •
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This PR lifts the restriction on the modification of input and "peek" variables.

This restriction was supposed to help avoid reference leaks, but actually just makes it annoying and inefficient to change values on the stack.
Plus, we have a better way to detect leaks on the stack: Py_STACKREF_DEBUG.

Doing this allows us to clean up some code and, more importantly for TOS caching, turn some arrays back into scalars.

This PR modifies SWAP and _MAKE_CALLARGS_A_TUPLE to demonstrate the simplification.
We can make further simplifications, but I'll save those for an other PR for ease of review.

  • Issue: Top-of-stack caching in the interpreter #131498

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@markshannon
Allow 'peek' variables to be modified
733e308
@bedevere-app bedevere-app Bot added the awaiting core review label Apr 14, 2025
@bedevere-app bedevere-app Bot mentioned this pull request Apr 14, 2025
Top-of-stack caching in the interpreter #131498
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@markshannon markshannon added the skip news label Apr 14, 2025
iritkatriel
iritkatriel approved these changes Apr 14, 2025
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@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting core review labels Apr 14, 2025
@markshannon
markshannon merged commit 844596c into python:main Apr 14, 2025
@bedevere-app bedevere-app Bot removed the awaiting merge label Apr 14, 2025
@markshannon
markshannon deleted the allow-modification-peek-variables branch April 14, 2025 11:19
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@iritkatriel iritkatriel iritkatriel approved these changes

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@markshannon @iritkatriel
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