{"record":{"id":"fb529266f3a33ab6","repo":"wasmerio/wasmer","slug":"unimplemented-operator-operator","errorCode":null,"errorMessage":"unimplemented operator {operator:?}","messagePattern":"unimplemented operator (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"lib/c-api/src/wasm_c_api/unstable/parser/operator.rs","lineNumber":1076,"sourceCode":"            O::I32x4TruncSatF64x2SZero => Self::I32x4TruncSatF64x2SZero,\n            O::I32x4TruncSatF64x2UZero => Self::I32x4TruncSatF64x2UZero,\n            O::I8x16RelaxedSwizzle => Self::I8x16RelaxedSwizzle,\n            O::I32x4RelaxedTruncF32x4S => Self::I32x4RelaxedTruncSatF32x4S,\n            O::I32x4RelaxedTruncF32x4U => Self::I32x4RelaxedTruncSatF32x4U,\n            O::I32x4RelaxedTruncF64x2SZero => Self::I32x4RelaxedTruncSatF64x2SZero,\n            O::I32x4RelaxedTruncF64x2UZero => Self::I32x4RelaxedTruncSatF64x2UZero,\n            O::F32x4RelaxedMadd => Self::F32x4Fma,\n            O::I8x16RelaxedLaneselect => Self::I8x16LaneSelect,\n            O::I16x8RelaxedLaneselect => Self::I16x8LaneSelect,\n            O::I32x4RelaxedLaneselect => Self::I32x4LaneSelect,\n            O::I64x2RelaxedLaneselect => Self::I64x2LaneSelect,\n            O::F32x4RelaxedMin => Self::F32x4RelaxedMin,\n            O::F32x4RelaxedMax => Self::F32x4RelaxedMax,\n            O::F64x2RelaxedMin => Self::F64x2RelaxedMin,\n            O::F64x2RelaxedMax => Self::F64x2RelaxedMax,\n            O::I16x8RelaxedQ15mulrS => Self::I16x8RelaxedQ15mulrS,\n            _ => {\n                panic!(\"unimplemented operator {operator:?}\");\n            }\n        }\n    }\n}\n","sourceCodeStart":1058,"sourceCodeEnd":1081,"githubUrl":"https://github.com/wasmerio/wasmer/blob/8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5/lib/c-api/src/wasm_c_api/unstable/parser/operator.rs#L1058-L1081","documentation":"The C API parser converts internal operator enums (O::...) into public wasm operators. When the conversion encounters an operator it has no mapping for, it panics with \"unimplemented operator\". This indicates the parser produced/reached an operator the C API layer has not implemented yet, typically a newer SIMD or relaxed-simd instruction.","triggerScenarios":"Parsing a Wasm module (via the unstable C API parser) that contains an operator whose From arm is missing — usually an uncommon SIMD or relaxed-simd op beyond those explicitly mapped — hitting the `_ => panic!` catch-all in the From impl.","commonSituations":"Loading modules compiled with newer wasm extensions (relaxed SIMD, new proposals) than the C API layer supports; using the unstable parser API on modules with exotic instructions; Wasmer version where an operator was added internally but not yet exposed via the C API.","solutions":["Upgrade Wasmer to a version where the operator is implemented in the C API parser.","Recompile the Wasm module targeting an older/standard feature set (e.g. avoid relaxed-simd: compile with -mno-relaxed-simd or disable the proposal).","Use the Rust API or engine-based compilation instead of the unstable C API parser, which has wider operator coverage.","Report/file an issue with the specific operator printed in the panic so coverage can be added."],"exampleFix":"// before\nclang --target=wasm32 -msimd128 -mrelaxed-simd -o app.wasm app.c\nwasmer_module_parse(..., app.wasm) // panics on relaxed op\n// after\nclang --target=wasm32 -msimd128 -o app.wasm app.c // standard SIMD only","handlingStrategy":"fallback","validationCode":"// Pre-scan module features before parsing (Wasm features section):\n// reject modules declaring relaxed-simd when using the unstable C API parser\nfn parser_supports(features: &WasmFeatures) -> bool {\n    !features.contains(WasmFeatures::RELAXED_SIMD)\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Compile Wasm modules with only SIMD extensions your Wasmer version supports.","Prefer the Rust API or engine-based compilation over the unstable parser.","Keep Wasmer updated for new proposal coverage."],"tags":["rust","panic","c-api","parser","simd","wasm"],"backgroundTag":"unimplemented-operator","analyzedSha":"8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5","analyzedAt":"2026-09-01T23:06:31.009Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-09T06:17:21.866Z"}