private MethodDefinition ExposeMethod(TypeDefinition typeToProcess, FieldReference fieldToProcess, MethodReference methodToExpose, ExposeMode exposeMode, MethodSemanticsAttributes semanticAttributes)
{
var typeToExpose = fieldToProcess.FieldType;
var genericTypeToExpose = typeToExpose as GenericInstanceType;
MethodReference methodToExposeWithResolvedGenerics = null;
if (genericTypeToExpose != null)
{
methodToExposeWithResolvedGenerics = methodToExpose.With(declaringType: methodToExpose.DeclaringType.MakeGenericInstanceType(genericTypeToExpose.GenericArguments.ToArray()), resolveGenericReturnTypeAndParameterTypes: true);
methodToExpose = methodToExpose.With(declaringType: methodToExpose.DeclaringType.MakeGenericInstanceType(genericTypeToExpose.GenericArguments.ToArray()), resolveGenericReturnTypeAndParameterTypes: false);
}
var name = exposeMode == ExposeMode.ImplementExplicit ? typeToExpose.FullName + "." + methodToExpose.Name : methodToExpose.Name;
MethodAttributes methodAttributes = (exposeMode == ExposeMode.ImplementExplicit ? MethodAttributes.Private : MethodAttributes.Public);
if (exposeMode == ExposeMode.ImplementImplicit || exposeMode == ExposeMode.ImplementExplicit)
methodAttributes |= MethodAttributes.Final;
methodAttributes |= MethodAttributes.HideBySig;
if (semanticAttributes != MethodSemanticsAttributes.None)
methodAttributes |= MethodAttributes.SpecialName;
if (exposeMode == ExposeMode.ImplementImplicit || exposeMode == ExposeMode.ImplementExplicit)
methodAttributes |= MethodAttributes.NewSlot | MethodAttributes.Virtual;
var method = new MethodDefinition(name, methodAttributes, (methodToExposeWithResolvedGenerics ?? methodToExpose).ReturnType);
foreach (var genericParameter in (methodToExposeWithResolvedGenerics ?? methodToExpose).GenericParameters)
{
method.GenericParameters.Add(new GenericParameter(genericParameter.Name, method));
}
foreach (var parameter in (methodToExposeWithResolvedGenerics ?? methodToExpose).Parameters)
{
method.Parameters.Add(new ParameterDefinition(parameter.Name, parameter.Attributes, parameter.ParameterType));
}
var existingMethod = typeToProcess.GetMethodLike(method);
if (existingMethod != null)
return existingMethod;
bool methodReturnsVoid = method.ReturnType.FullName == ModuleDefinition.TypeSystem.Void.FullName;
if (!methodReturnsVoid)
{
method.Body.Variables.Add(new VariableDefinition(method.ReturnType));
method.Body.InitLocals = true;
}
var instructions = method.Body.Instructions;
instructions.Add(Instruction.Create(OpCodes.Nop));
instructions.Add(Instruction.Create(OpCodes.Ldarg_0)); // Load this
instructions.Add(Instruction.Create(OpCodes.Ldfld,
fieldToProcess.DeclaringType.HasGenericParameters ?
fieldToProcess.With(declaringType: fieldToProcess.DeclaringType.MakeGenericInstanceTypeWithGenericParametersAsGenericArguments())
: fieldToProcess)
);
if (methodToExpose.Parameters.Count >= 1) instructions.Add(Instruction.Create(OpCodes.Ldarg_1));
if (methodToExpose.Parameters.Count >= 2) instructions.Add(Instruction.Create(OpCodes.Ldarg_2));
if (methodToExpose.Parameters.Count >= 3) instructions.Add(Instruction.Create(OpCodes.Ldarg_3));
if (methodToExpose.Parameters.Count >= 4)
{
for (var i = 3; i < methodToExpose.Parameters.Count; i++)
{
instructions.Add(Instruction.Create(OpCodes.Ldarg_S, i + 1));
}
}
instructions.Add(Instruction.Create(OpCodes.Callvirt, methodToExpose.HasGenericParameters ? methodToExpose.MakeGenericInstanceMethod(method.GenericParameters.ToArray()) : methodToExpose));
if (methodReturnsVoid)
instructions.Add(Instruction.Create(OpCodes.Nop));
else
{
instructions.Add(Instruction.Create(OpCodes.Stloc_0));
var inst = Instruction.Create(OpCodes.Ldloc_0);
instructions.Add(Instruction.Create(OpCodes.Br_S, inst));
instructions.Add(inst);
}
instructions.Add(Instruction.Create(OpCodes.Ret));
if (exposeMode == ExposeMode.ImplementExplicit)
method.Overrides.Add(methodToExpose);
AddFodyGeneratedAttributes(method);
typeToProcess.Methods.Add(method);
return method;
}
