public virtual MethodBuilder CreateMethod(ProxyScope proxyScope, MethodDefinition methodDefinition, MemberInfo member, FieldBuilder memberField, FieldBuilder callerMethodField)
{
MethodInfo method = methodDefinition.Method;
// callback method
MethodBuilder callbackMethodBuilder = CreateCallbackMethod(proxyScope, methodDefinition.CallbackMethodDefinition);
// invocation type
Type invocationType = GetOrCreateInvocationType(proxyScope, methodDefinition, callbackMethodBuilder);
// method
MethodBuilder methodBuilder = proxyScope.DefineMethod(methodDefinition.Name, methodDefinition.MethodAttributes);
methodBuilder.SetReturnType(methodDefinition.ReturnType);
// parameters
methodBuilder.DefineGenericParameters(methodDefinition.GenericArguments);
if (methodDefinition.ParameterDefinitions.Length > 0)
{
DefineParameters(methodBuilder, methodDefinition);
}
// attributes
DefineAttributes(methodBuilder, methodDefinition);
// method body
var il = methodBuilder.GetILGenerator();
// locals
IInterceptorSelector interceptorSelector = proxyScope.TypeDefinition.Options?.InterceptorSelector;
FieldBuilder interceptorSelectorField = null;
FieldBuilder interceptorMethodField = null;
if (interceptorSelector != null)
{
interceptorSelectorField = FindConstructorField(proxyScope, ProxyScope.InterceptorSelectorFieldName);
interceptorMethodField = proxyScope.DefineField(methodDefinition.InterceptorSelectorFieldName, typeof(IInterceptor[]), FieldAttributes.Private);
}
var returnType = methodDefinition.ReturnType;
Type targetType = methodDefinition.TypeDefinition.TargetType;
Type localBuilderType = targetType != null ? targetType : typeof(object);
LocalBuilder targetLocalBuilder = il.DeclareLocal(localBuilderType); // target
LocalBuilder interceptorsLocalBuilder = il.DeclareLocal(typeof(IInterceptor[])); // interceptors
LocalBuilder memberLocalBuilder = il.DeclareLocal(typeof(MemberInfo)); // MemberInfo
LocalBuilder callerMethodLocalBuilder = il.DeclareLocal(typeof(MethodInfo)); // proxy method
LocalBuilder proxyLocalBuilder = il.DeclareLocal(typeof(object)); // proxy
LocalBuilder parametersLocalBuilder = il.DeclareLocal(typeof(object[])); // parameters
LocalBuilder invocationLocalBuilder = il.DeclareLocal(invocationType); // invocation
LocalBuilder returnValueLocalBuilder = null;
if (returnType != typeof(void))
{
returnValueLocalBuilder = il.DeclareLocal(returnType);
}
FieldBuilder interceptorsField = proxyScope.ConstructorFields[0];
if (targetType != null)
{
FieldBuilder targetField = FindConstructorField(proxyScope, methodDefinition.TypeDefinition.TargetFieldName);
EmitHelper.StoreFieldToLocal(il, targetField, targetLocalBuilder);
}
EmitHelper.StoreFieldToLocal(il, memberField, memberLocalBuilder);
EmitHelper.StoreFieldToLocal(il, callerMethodField, callerMethodLocalBuilder);
EmitHelper.StoreThisToLocal(il, proxyLocalBuilder);
if (interceptorSelector != null)
{
LocalBuilder isNullLocal = il.DeclareLocal(typeof(bool));
Label isNullLabel = il.DefineLabel();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, interceptorMethodField);
il.Emit(OpCodes.Ldnull);
il.Emit(OpCodes.Ceq);
il.Emit(OpCodes.Stloc, isNullLocal);
il.Emit(OpCodes.Ldloc, isNullLocal);
il.Emit(OpCodes.Brfalse_S, isNullLabel);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, interceptorSelectorField);
il.Emit(OpCodes.Ldtoken, member.DeclaringType);
il.Emit(OpCodes.Call, Methods.GetTypeFromHandle);
il.Emit(OpCodes.Ldloc, callerMethodLocalBuilder);
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, interceptorsField);
il.Emit(OpCodes.Callvirt, Methods.SelectInterceptorsMethod);
il.Emit(OpCodes.Stfld, interceptorMethodField);
il.MarkLabel(isNullLabel);
EmitHelper.StoreFieldToLocal(il, interceptorMethodField, interceptorsLocalBuilder);
}
else
{
EmitHelper.StoreFieldToLocal(il, interceptorsField, interceptorsLocalBuilder);
}
StoreArgsToArray(il, methodDefinition.ParameterDefinitions, parametersLocalBuilder);
EmitHelper.CreateInvocation(il, invocationType, targetLocalBuilder, interceptorsLocalBuilder, memberLocalBuilder, callerMethodLocalBuilder, proxyLocalBuilder, parametersLocalBuilder, invocationLocalBuilder);
EmitHelper.CallProceed(il, invocationLocalBuilder);
// set ref parameters values after Proceed called
SetByRefArgs(il, methodDefinition.ParameterDefinitions, invocationLocalBuilder);
EmitReturnValue(il, method, invocationLocalBuilder, returnValueLocalBuilder);
if (method.DeclaringType.IsInterface)
{
proxyScope.DefineMethodOverride(methodBuilder, method);
}
return(methodBuilder);
}