FA-11511 / Static analysis soundness / Open access
An ambiguous pointer store kills possible old values · case 01
An ambiguous pointer store kills possible old values.
ROOT CAUSE
A store through a may-alias pointer is treated as a definite overwrite of every target.
THE FAILURE
A store through a may-alias pointer is treated as a definite overwrite of every target.
Unsuccessful approach: Always weakly updating is conservative but fails the required singleton precision.
Case contract
Heap maps allocated object names to possible integer values. Every target must name an allocated object already present in the heap; dangling targets are outside this model. Store a known value through a list of possible targets: unique target replaces, multiple targets union, empty target list changes nothing. Return sorted value lists.
Why this case matters
A deterministic offline analysis model exposing a specific soundness or precision boundary; it does not implement a complete language analyzer.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(heap, targets, value):
out={k:set(v) for k,v in heap.items()}
for k in set(targets): out[k]={value}
return {k:sorted(v) for k,v in out.items()}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('ambiguous store',solve({'a':[0],'b':[1]},['a','b'],N+2),{'a':[0,N+2],'b':[1,N+2]})
check('definite store',solve({'a':[0]},['a'],N),{'a':[N]})
check('duplicate target is unique',solve({'a':[0]},['a','a'],N),{'a':[N]})
check('no target',solve({'a':[N]},[],0),{'a':[N]})
check('unrelated object',solve({'a':[0],'b':[N]},['a'],1),{'a':[1],'b':[N]})
check('empty heap',solve({},[],N),{})
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| ambiguous store | {'a': [3], 'b': [3]} | {'a': [0, 3], 'b': [1, 3]} | Failed |
| definite store | {'a': [1]} | {'a': [1]} | Passed |
| duplicate target is unique | {'a': [1]} | {'a': [1]} | Passed |
| no target | {'a': [1]} | {'a': [1]} | Passed |
| unrelated object | {'a': [1], 'b': [1]} | {'a': [1], 'b': [1]} | Passed |
| empty heap | {} | {} | Passed |
SHA-256 / 818e3bbe6ca159e8cc91d2c9f4da0b0d210a6a1b314716d40bad5e5ec02c33cd
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(heap, targets, value):
out={k:set(v) for k,v in heap.items()}
for k in set(targets): out[k].add(value)
return {k:sorted(v) for k,v in out.items()}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('ambiguous store',solve({'a':[0],'b':[1]},['a','b'],N+2),{'a':[0,N+2],'b':[1,N+2]})
check('definite store',solve({'a':[0]},['a'],N),{'a':[N]})
check('duplicate target is unique',solve({'a':[0]},['a','a'],N),{'a':[N]})
check('no target',solve({'a':[N]},[],0),{'a':[N]})
check('unrelated object',solve({'a':[0],'b':[N]},['a'],1),{'a':[1],'b':[N]})
check('empty heap',solve({},[],N),{})
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| ambiguous store | {'a': [0, 3], 'b': [1, 3]} | {'a': [0, 3], 'b': [1, 3]} | Passed |
| definite store | {'a': [0, 1]} | {'a': [1]} | Failed |
| duplicate target is unique | {'a': [0, 1]} | {'a': [1]} | Failed |
| no target | {'a': [1]} | {'a': [1]} | Passed |
| unrelated object | {'a': [0, 1], 'b': [1]} | {'a': [1], 'b': [1]} | Failed |
| empty heap | {} | {} | Passed |
SHA-256 / 0e0dfc93c4ba51cc9770d7608db1217d78f67a0cf2bddb601bb8bc448666ae58
HELD IN THE MEMBER ARCHIVE
The verified repair and its recorded checks are member-only.
This mechanism has 6 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.
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Sign in to the archive ↗Verification & scope
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 2026-09-29T14:38:48.607947+00:00.
Case digest / 3dbf9209ed11f1061a32aef30d396ed2e329417328e7810764ad8a948b4b3ca4