FA-43682 / Borrow checking / Member archive

Unwinding drops an uninitialized field and invents borrow obligations · case 02

Unwinding drops an uninitialized field and invents borrow obligations.

Member previewVariant 2 · 3 implementations · 21 checks per implementation

Case contract

Check destructor-specific lifetime obligations. Destructor-read referents live at drop point; field destruction follows declaration order; explicit manual drop removes only its own drop obligation; may_dangle relaxation excludes observed parameters; owning phantom markers restore transitive drop obligations; arrays repeat element obligations even at nonzero symbolic lengths; partial move prohibited for custom-drop values; recursive drop dependencies need a visited set but may not skip distinct substitutions; unwinding runs initialized-field drops; destructor receiver borrow stays live through the whole body. Input is a fully explicit descriptor of the stated toy IR. Return rule identifiers in declaration order; absent optional obligations use the provided neutral defaults. No rule is an assertion about a production language.

Why this case matters

A finite offline static-analysis model of ownership and borrowing; it does not execute the analyzed program.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
unwind-initialized-drops regression 0	`[]`	`["unwind-initialized-drops"]`	Failed

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