{"abstract":"A definition kills its own incoming operand use.","category":"Static analysis soundness","checks":6,"contract":"Return sorted live-in variables for one instruction: uses union (live-out minus definitions). Uses occur before this instruction writes definitions.","evaluation_group":"model-e94019b994f6a6e5","failed_approach":"Removing the kill entirely preserves overwritten values that have no incoming use.","family":"z-static_analysis-liveness-self-use","id":"FA-11516","implementations":{"attempt":{"sha256":"ca5ad90226049afeb533a51a4d1ad46717abab1ad3559f3278146c4a60d73a64","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(out, defs, uses):\n    return sorted(set(out)|set(uses))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nx='v'+str(N)\ncheck('read modify write',solve([],[x],[x]),[x])\ncheck('overwrite dead incoming',solve([x],[x],[]),[])\ncheck('independent use',solve([],[x],['a']),['a'])\ncheck('passthrough',solve([x],[],[]),[x])\ncheck('empty instruction',solve([],[],[]),[])\ncheck('other live value',solve(['a',x],[x],[x]),['a',x])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"6bd5e176f8264ed2210dcc8a9ca011aed93c23bbedec68c0c84387962a2e60f7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(out, defs, uses):\n    return sorted((set(out)|set(uses))-set(defs))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nx='v'+str(N)\ncheck('read modify write',solve([],[x],[x]),[x])\ncheck('overwrite dead incoming',solve([x],[x],[]),[])\ncheck('independent use',solve([],[x],['a']),['a'])\ncheck('passthrough',solve([x],[],[]),[x])\ncheck('empty instruction',solve([],[],[]),[])\ncheck('other live value',solve(['a',x],[x],[x]),['a',x])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"706addde3a8ff682e6478b8fbdc49a825979709bd488df103d023e4b54dd7859","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(out, defs, uses):\n    return sorted(set(uses)|(set(out)-set(defs)))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nx='v'+str(N)\ncheck('read modify write',solve([],[x],[x]),[x])\ncheck('overwrite dead incoming',solve([x],[x],[]),[])\ncheck('independent use',solve([],[x],['a']),['a'])\ncheck('passthrough',solve([x],[],[]),[x])\ncheck('empty instruction',solve([],[],[]),[])\ncheck('other live value',solve(['a',x],[x],[x]),['a',x])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"z-static_analysis-liveness-self-use","generated_at":"2026-09-29T14:38:48.643333+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic offline analysis model exposing a specific soundness or precision boundary; it does not implement a complete language analyzer.","repair":"Kill outgoing definitions first, then generate all incoming uses.","root_cause":"The backward transfer removes definitions after inserting uses.","sha256":"800cdcf6815b6030d3d7e0ab3b3ce4266d6878f407cc1259d408b7f8a4643883","title":"A definition kills its own incoming operand use · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.735,"exit_code":1,"observations":[{"actual":["v1"],"check":"read modify write","expected":["v1"],"passed":true},{"actual":["v1"],"check":"overwrite dead incoming","expected":[],"passed":false},{"actual":["a"],"check":"independent use","expected":["a"],"passed":true},{"actual":["v1"],"check":"passthrough","expected":["v1"],"passed":true},{"actual":[],"check":"empty instruction","expected":[],"passed":true},{"actual":["a","v1"],"check":"other live value","expected":["a","v1"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"read modify write\", \"actual\": [\"v1\"], \"expected\": [\"v1\"], \"passed\": true}, {\"check\": \"overwrite dead incoming\", \"actual\": [\"v1\"], \"expected\": [], \"passed\": false}, {\"check\": \"independent use\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"passthrough\", \"actual\": [\"v1\"], \"expected\": [\"v1\"], \"passed\": true}, {\"check\": \"empty instruction\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"other live value\", \"actual\": [\"a\", \"v1\"], \"expected\": [\"a\", \"v1\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.743,"exit_code":1,"observations":[{"actual":[],"check":"read modify write","expected":["v1"],"passed":false},{"actual":[],"check":"overwrite dead incoming","expected":[],"passed":true},{"actual":["a"],"check":"independent use","expected":["a"],"passed":true},{"actual":["v1"],"check":"passthrough","expected":["v1"],"passed":true},{"actual":[],"check":"empty instruction","expected":[],"passed":true},{"actual":["a"],"check":"other live value","expected":["a","v1"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"read modify write\", \"actual\": [], \"expected\": [\"v1\"], \"passed\": false}, {\"check\": \"overwrite dead incoming\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"independent use\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"passthrough\", \"actual\": [\"v1\"], \"expected\": [\"v1\"], \"passed\": true}, {\"check\": \"empty instruction\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"other live value\", \"actual\": [\"a\"], \"expected\": [\"a\", \"v1\"], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.844,"exit_code":0,"observations":[{"actual":["v1"],"check":"read modify write","expected":["v1"],"passed":true},{"actual":[],"check":"overwrite dead incoming","expected":[],"passed":true},{"actual":["a"],"check":"independent use","expected":["a"],"passed":true},{"actual":["v1"],"check":"passthrough","expected":["v1"],"passed":true},{"actual":[],"check":"empty instruction","expected":[],"passed":true},{"actual":["a","v1"],"check":"other live value","expected":["a","v1"],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"read modify write\", \"actual\": [\"v1\"], \"expected\": [\"v1\"], \"passed\": true}, {\"check\": \"overwrite dead incoming\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"independent use\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"passthrough\", \"actual\": [\"v1\"], \"expected\": [\"v1\"], \"passed\": true}, {\"check\": \"empty instruction\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"other live value\", \"actual\": [\"a\", \"v1\"], \"expected\": [\"a\", \"v1\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}