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FA-43721 / Borrow checking / Open access

Pin wrapper conversion manufactures exclusive access from a shared pointer · case 01

Pin wrapper conversion manufactures exclusive access from a shared pointer.

Verified by executionVariant 1 · 21 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The static analyzer mishandles shared pin uniqueness: pin wrapper conversion manufactures exclusive access from a shared pointer.

THE FAILURE

The static analyzer mishandles shared pin uniqueness: pin wrapper conversion manufactures exclusive access from a shared pointer.

Unsuccessful approach: The partial repair uses if d['source_shared'] and d['unique_projection'] and d['pinned']: errors.append('shared-pin-uniqueness'), which still violates the stipulated analysis contract.

Case contract

Check a toy pin-aware ownership IR. Pinned non-Unpin values may not move; field projection requires structural pin declaration; unpinned fields remain movable; replace through pinned reference requires Unpin; pinned destructor cannot move receiver; packing disallows safe pinned field references; projecting through shared pointer cannot produce unique pinned reference; converting pin to raw keeps provenance; unchecked pin construction requires an explicit immovability proof; frame relocation invalidates an earlier pin proof. 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.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    errors=[]
    if d['pinned'] and not d['unpin'] and bool(d['moves']): errors.append('pinned-move')
    if not set(d['projected'])<=set(d['structural']): errors.append('structural-projection')
    if bool(set(d['unpin_fields'])&set(d['blocked_fields'])): errors.append('unpinned-field-move')
    if d['pinned'] and not d['unpin'] and d['replace']: errors.append('pin-replace')
    if d['pinned'] and d['destructor_move']: errors.append('pinned-destructor')
    if bool(set(d['projected'])&set(d['packed_fields'])): errors.append('packed-pin')
    if False: errors.append('shared-pin-uniqueness')
    if d['raw_origin']!=d['pin_origin']: errors.append('raw-pin-provenance')
    if d['unchecked_construct'] and not d['proof']: errors.append('unchecked-pin-proof')
    if d['pin_generation']!=d['frame_generation']: errors.append('pin-relocation')
    return errors
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
base={'pinned': False, 'unpin': True, 'moves': [], 'projected': [], 'structural': [], 'unpin_fields': [], 'blocked_fields': [], 'replace': False, 'destructor_move': False, 'packed_fields': [], 'source_shared': False, 'unique_projection': False, 'raw_origin': None, 'pin_origin': None, 'unchecked_construct': False, 'proof': False, 'pin_generation': 0, 'frame_generation': 0}
check('well formed empty obligations',solve(base),[])
check('pinned-move regression 0', solve(dict(base, **({'pinned':True,'unpin':False,'moves':['x']}))), ['pinned-move'])
check('pinned-move regression 1', solve(dict(base, **({'pinned':True,'unpin':False,'moves':[N]}))), ['pinned-move'])
check('structural-projection regression 0', solve(dict(base, **({'projected':['a','b'],'structural':['a']}))), ['structural-projection'])
check('structural-projection regression 1', solve(dict(base, **({'projected':[N,N+1],'structural':[N]}))), ['structural-projection'])
check('unpinned-field-move regression 0', solve(dict(base, **({'unpin_fields':['a'],'blocked_fields':['a']}))), ['unpinned-field-move'])
check('unpinned-field-move regression 1', solve(dict(base, **({'unpin_fields':[N],'blocked_fields':[N]}))), ['unpinned-field-move'])
check('pin-replace regression 0', solve(dict(base, **({'pinned':True,'unpin':False,'replace':True}))), ['pin-replace'])
check('pin-replace regression 1', solve(dict(base, **({'pinned':True,'unpin':False,'replace':True,'frame_generation':N,'pin_generation':N}))), ['pin-replace'])
check('pinned-destructor regression 0', solve(dict(base, **({'pinned':True,'destructor_move':True}))), ['pinned-destructor'])
check('pinned-destructor regression 1', solve(dict(base, **({'pinned':True,'destructor_move':True,'frame_generation':N,'pin_generation':N}))), ['pinned-destructor'])
check('packed-pin regression 0', solve(dict(base, **({'projected':['a'],'structural':['a'],'packed_fields':['a']}))), ['packed-pin'])
check('packed-pin regression 1', solve(dict(base, **({'projected':[N],'structural':[N],'packed_fields':[N]}))), ['packed-pin'])
check('shared-pin-uniqueness regression 0', solve(dict(base, **({'source_shared':True,'unique_projection':True}))), ['shared-pin-uniqueness'])
check('shared-pin-uniqueness regression 1', solve(dict(base, **({'source_shared':True,'unique_projection':True,'frame_generation':N,'pin_generation':N}))), ['shared-pin-uniqueness'])
check('raw-pin-provenance regression 0', solve(dict(base, **({'raw_origin':'b','pin_origin':'a'}))), ['raw-pin-provenance'])
check('raw-pin-provenance regression 1', solve(dict(base, **({'raw_origin':N+1,'pin_origin':N}))), ['raw-pin-provenance'])
check('unchecked-pin-proof regression 0', solve(dict(base, **({'unchecked_construct':True}))), ['unchecked-pin-proof'])
check('unchecked-pin-proof regression 1', solve(dict(base, **({'unchecked_construct':True,'frame_generation':N,'pin_generation':N}))), ['unchecked-pin-proof'])
check('pin-relocation regression 0', solve(dict(base, **({'pin_generation':N,'frame_generation':N+1}))), ['pin-relocation'])
check('pin-relocation regression 1', solve(dict(base, **({'pin_generation':N+1,'frame_generation':N+2}))), ['pin-relocation'])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
well formed empty obligations[][]Passed
pinned-move regression 0['pinned-move']['pinned-move']Passed
pinned-move regression 1['pinned-move']['pinned-move']Passed
structural-projection regression 0['structural-projection']['structural-projection']Passed
structural-projection regression 1['structural-projection']['structural-projection']Passed
unpinned-field-move regression 0['unpinned-field-move']['unpinned-field-move']Passed
unpinned-field-move regression 1['unpinned-field-move']['unpinned-field-move']Passed
pin-replace regression 0['pin-replace']['pin-replace']Passed
pin-replace regression 1['pin-replace']['pin-replace']Passed
pinned-destructor regression 0['pinned-destructor']['pinned-destructor']Passed
pinned-destructor regression 1['pinned-destructor']['pinned-destructor']Passed
packed-pin regression 0['packed-pin']['packed-pin']Passed
packed-pin regression 1['packed-pin']['packed-pin']Passed
shared-pin-uniqueness regression 0[]['shared-pin-uniqueness']Failed
shared-pin-uniqueness regression 1[]['shared-pin-uniqueness']Failed
raw-pin-provenance regression 0['raw-pin-provenance']['raw-pin-provenance']Passed
raw-pin-provenance regression 1['raw-pin-provenance']['raw-pin-provenance']Passed
unchecked-pin-proof regression 0['unchecked-pin-proof']['unchecked-pin-proof']Passed
unchecked-pin-proof regression 1['unchecked-pin-proof']['unchecked-pin-proof']Passed
pin-relocation regression 0['pin-relocation']['pin-relocation']Passed
pin-relocation regression 1['pin-relocation']['pin-relocation']Passed

SHA-256 / 6036f5a1acf2c5a5d01fe691aa9e5863165f1941204e584b5b97d6d7784acf1c

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    errors=[]
    if d['pinned'] and not d['unpin'] and bool(d['moves']): errors.append('pinned-move')
    if not set(d['projected'])<=set(d['structural']): errors.append('structural-projection')
    if bool(set(d['unpin_fields'])&set(d['blocked_fields'])): errors.append('unpinned-field-move')
    if d['pinned'] and not d['unpin'] and d['replace']: errors.append('pin-replace')
    if d['pinned'] and d['destructor_move']: errors.append('pinned-destructor')
    if bool(set(d['projected'])&set(d['packed_fields'])): errors.append('packed-pin')
    if d['source_shared'] and d['unique_projection'] and d['pinned']: errors.append('shared-pin-uniqueness')
    if d['raw_origin']!=d['pin_origin']: errors.append('raw-pin-provenance')
    if d['unchecked_construct'] and not d['proof']: errors.append('unchecked-pin-proof')
    if d['pin_generation']!=d['frame_generation']: errors.append('pin-relocation')
    return errors
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
base={'pinned': False, 'unpin': True, 'moves': [], 'projected': [], 'structural': [], 'unpin_fields': [], 'blocked_fields': [], 'replace': False, 'destructor_move': False, 'packed_fields': [], 'source_shared': False, 'unique_projection': False, 'raw_origin': None, 'pin_origin': None, 'unchecked_construct': False, 'proof': False, 'pin_generation': 0, 'frame_generation': 0}
check('well formed empty obligations',solve(base),[])
check('pinned-move regression 0', solve(dict(base, **({'pinned':True,'unpin':False,'moves':['x']}))), ['pinned-move'])
check('pinned-move regression 1', solve(dict(base, **({'pinned':True,'unpin':False,'moves':[N]}))), ['pinned-move'])
check('structural-projection regression 0', solve(dict(base, **({'projected':['a','b'],'structural':['a']}))), ['structural-projection'])
check('structural-projection regression 1', solve(dict(base, **({'projected':[N,N+1],'structural':[N]}))), ['structural-projection'])
check('unpinned-field-move regression 0', solve(dict(base, **({'unpin_fields':['a'],'blocked_fields':['a']}))), ['unpinned-field-move'])
check('unpinned-field-move regression 1', solve(dict(base, **({'unpin_fields':[N],'blocked_fields':[N]}))), ['unpinned-field-move'])
check('pin-replace regression 0', solve(dict(base, **({'pinned':True,'unpin':False,'replace':True}))), ['pin-replace'])
check('pin-replace regression 1', solve(dict(base, **({'pinned':True,'unpin':False,'replace':True,'frame_generation':N,'pin_generation':N}))), ['pin-replace'])
check('pinned-destructor regression 0', solve(dict(base, **({'pinned':True,'destructor_move':True}))), ['pinned-destructor'])
check('pinned-destructor regression 1', solve(dict(base, **({'pinned':True,'destructor_move':True,'frame_generation':N,'pin_generation':N}))), ['pinned-destructor'])
check('packed-pin regression 0', solve(dict(base, **({'projected':['a'],'structural':['a'],'packed_fields':['a']}))), ['packed-pin'])
check('packed-pin regression 1', solve(dict(base, **({'projected':[N],'structural':[N],'packed_fields':[N]}))), ['packed-pin'])
check('shared-pin-uniqueness regression 0', solve(dict(base, **({'source_shared':True,'unique_projection':True}))), ['shared-pin-uniqueness'])
check('shared-pin-uniqueness regression 1', solve(dict(base, **({'source_shared':True,'unique_projection':True,'frame_generation':N,'pin_generation':N}))), ['shared-pin-uniqueness'])
check('raw-pin-provenance regression 0', solve(dict(base, **({'raw_origin':'b','pin_origin':'a'}))), ['raw-pin-provenance'])
check('raw-pin-provenance regression 1', solve(dict(base, **({'raw_origin':N+1,'pin_origin':N}))), ['raw-pin-provenance'])
check('unchecked-pin-proof regression 0', solve(dict(base, **({'unchecked_construct':True}))), ['unchecked-pin-proof'])
check('unchecked-pin-proof regression 1', solve(dict(base, **({'unchecked_construct':True,'frame_generation':N,'pin_generation':N}))), ['unchecked-pin-proof'])
check('pin-relocation regression 0', solve(dict(base, **({'pin_generation':N,'frame_generation':N+1}))), ['pin-relocation'])
check('pin-relocation regression 1', solve(dict(base, **({'pin_generation':N+1,'frame_generation':N+2}))), ['pin-relocation'])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
well formed empty obligations[][]Passed
pinned-move regression 0['pinned-move']['pinned-move']Passed
pinned-move regression 1['pinned-move']['pinned-move']Passed
structural-projection regression 0['structural-projection']['structural-projection']Passed
structural-projection regression 1['structural-projection']['structural-projection']Passed
unpinned-field-move regression 0['unpinned-field-move']['unpinned-field-move']Passed
unpinned-field-move regression 1['unpinned-field-move']['unpinned-field-move']Passed
pin-replace regression 0['pin-replace']['pin-replace']Passed
pin-replace regression 1['pin-replace']['pin-replace']Passed
pinned-destructor regression 0['pinned-destructor']['pinned-destructor']Passed
pinned-destructor regression 1['pinned-destructor']['pinned-destructor']Passed
packed-pin regression 0['packed-pin']['packed-pin']Passed
packed-pin regression 1['packed-pin']['packed-pin']Passed
shared-pin-uniqueness regression 0[]['shared-pin-uniqueness']Failed
shared-pin-uniqueness regression 1[]['shared-pin-uniqueness']Failed
raw-pin-provenance regression 0['raw-pin-provenance']['raw-pin-provenance']Passed
raw-pin-provenance regression 1['raw-pin-provenance']['raw-pin-provenance']Passed
unchecked-pin-proof regression 0['unchecked-pin-proof']['unchecked-pin-proof']Passed
unchecked-pin-proof regression 1['unchecked-pin-proof']['unchecked-pin-proof']Passed
pin-relocation regression 0['pin-relocation']['pin-relocation']Passed
pin-relocation regression 1['pin-relocation']['pin-relocation']Passed

SHA-256 / cd9a3a58760023f9d25b8042b0b95ad2b2318398816b15162409975540887f0e

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 21 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

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Verification & scope

The explicitly stated toy language is the complete scope; this is not a production compiler or a claim about Rust semantics. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:44:05.100423+00:00.

Case digest / 09002c73849bfd14f028dd342d1a77a237365deaf401ef2fc15e276951a561e4