What causes "[PreservedMethod] method has generic parameters" in egametang/ET?

Ensure GenericArgumentContext is populated with all needed class and method instantiations before calling this overload.

egametang/ET · error · Exception

[PreservedMethod] method has generic parameters

Error message

[PreservedMethod] method has generic parameters

What it means

Thrown by the second CreateMethodDesc overload (the one without a MethodDef, used for synthetic/anonymous bridge methods) when returnType.ContainsGenericParameter is true. Unlike errors 193/194 this overload is for generated signatures that have no backing MethodDef, so the message omits the method name.

Source

Thrown at Packages/cn.etetet.hybridclr/Scripts/Editor/Share/MethodBridge/Generator.cs:148

                    throw new Exception($"[PreservedMethod] method:{methodDef} has generic parameters");
                }
                paramInfos.Add(new ParamInfo() { Type = GetSharedTypeInfo(paramInfo) });
            }
            var mbs = new MethodDesc()
            {
                MethodDef = methodDef,
                ReturnInfo = new ReturnInfo() { Type = returnType != null ? GetSharedTypeInfo(returnType) : TypeInfo.s_void },
                ParamInfos = paramInfos,
            };
            return mbs;
        }

        private MethodDesc CreateMethodDesc(TypeSig returnType, List<TypeSig> parameters)
        {
            var paramInfos = new List<ParamInfo>();
            if (returnType.ContainsGenericParameter)
            {
                throw new Exception($"[PreservedMethod] method has generic parameters");
            }
            foreach (var paramInfo in parameters)
            {
                if (paramInfo.ContainsGenericParameter)
                {
                    throw new Exception($"[PreservedMethod] method has generic parameters");
                }
                paramInfos.Add(new ParamInfo() { Type = GetSharedTypeInfo(paramInfo) });
            }
            var mbs = new MethodDesc()
            {
                MethodDef = null,
                ReturnInfo = new ReturnInfo() { Type = returnType != null ? GetSharedTypeInfo(returnType) : TypeInfo.s_void },
                ParamInfos = paramInfos,
            };
            return mbs;
        }

View on GitHub (pinned to 5cab01f7a8)

Solutions

Ensure GenericArgumentContext is populated with all needed class and method instantiations before calling this overload.
Run HybridCLR/Generate/AOTGenericReference to collect all instantiations, then regenerate bridges.
If this appears after a code change, review new generic method usage that crosses the AOT boundary.

Defensive patterns

Strategy: validation

Validate before calling

if (returnType != null && returnType.ContainsGenericParameter)
    Debug.LogError("Synthetic method return type has open generic parameter -- inflation incomplete.");

Prevention

Populate GenericArgumentContext with all class and method instantiations before creating synthetic bridge signatures.
Run AOTGenericReference before MethodBridge generation.
Review generic API changes that introduce new managed/native boundary methods.

When it happens

Trigger: CreateMethodDesc(TypeSig returnType, List<TypeSig> parameters) is called during generation of synthetic bridge methods (e.g. adjust-thunk or wrapper stubs) where the computed return type still contains a generic parameter, indicating the upstream inflation failed.

Common situations: A generic instantiation was not fully resolved before the synthetic method was created; GenericArgumentContext.Inflate left an open generic due to missing type arguments; a code path constructs a bridge signature from an uninstantiated generic method.

Related errors

AI-assisted analysis of egametang/ET@5cab01f7a8 (2026-08-13). Data as JSON: /api/errors/c9de02e36bdd2cfa. Report an issue: GitHub.