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Sam Gross
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After gh-130704, the interpreter replaces some uses of `LOAD_FAST` with `LOAD_FAST_BORROW` which avoid incref/decrefs by "borrowing" references on the interpreter stack when the bytecode compiler can determine that it's safe. This change broke some checks in C API extensions that relied on `Py_REFCNT()` of `1` to determine if it's safe to modify an object in-place. Objects may have a reference count of one, but still be referenced further up the interpreter stack due to borrowing of references. This provides a replacement function for those checks. `PyUnstable_Object_IsUniqueReferencedTemporary` is more conservative: it checks that the object has a reference count of one and that it exists as a unique strong reference in the interpreter's stack of temporary variables in the top most frame. See also: * https://github.com/numpy/numpy/issues/28681 Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com> Co-authored-by: T. Wouters <thomas@python.org> Co-authored-by: mpage <mpage@cs.stanford.edu> Co-authored-by: Mark Shannon <mark@hotpy.org> Co-authored-by: Victor Stinner <vstinner@python.org>
Tests in this directory are compiled into the _testcapi extension. The main file for the extension is Modules/_testcapimodule.c, which calls `_PyTestCapi_Init_*` from these functions. General guideline when writing test code for C API. * Use Argument Clinic to minimise the amount of boilerplate code. * Add a newline between the argument spec and the docstring. * If a test description is needed, make sure the added docstring clearly and succinctly describes purpose of the function. * DRY, use the clone feature of Argument Clinic. * Try to avoid adding new interned strings; reuse existing parameter names if possible. Use the `as` feature of Argument Clinic to override the C variable name, if needed.