fix: release overwritten runtime values

2026-09-22 12:29:00 +00:00
parent d60672f575
commit 3bfe881fba
4 changed files with 23 additions and 6 deletions
@@ -20,3 +20,9 @@ python3 tools/validate_memory_cleanup.py
 ```

 The validator builds an AddressSanitizer/UndefinedBehaviorSanitizer binary, runs a repeated variable-overwrite probe, and confirms LeakSanitizer no longer reports allocations from `tokenize`/`toks_add`. The interpreter remains a trusted-script runtime, not a sandbox.
+
+## Overwritten-value cleanup
+
+Runtime variables and map entries own deep copies of their values. Replacing an existing variable or map entry now releases the previous string, list, or map value before storing its replacement. This is intentionally limited to overwrite boundaries; final runtime teardown and discarded expression temporaries remain follow-up cleanup slices.
+
+Focused verification also checks the cleanup helper in the ASan/UBSan build and exercises string, list, and map overwrites without sanitizer errors.