private void BuildMethod(
TypeBuilder builder, ILGenerator gen, MethodBodyReader reader, Type[] realParameters,
Dictionary <string, FieldBuilder> fields, Dictionary <string, InterimMethod> methods, string memberName)
{
var fakeParameters = reader.Method.GetParameters().Skip(1).Select(p => p.ParameterType).ToArray();
var fakeReturn = (reader.Method as MethodInfo)?.ReturnType;
var writer = new MethodBodyBuilder(gen);
var locals = reader.Locals.Select(lc => lc.LocalType);
writer.DeclareLocals(locals);
writer.DeclareExceptionHandlers(reader.ExceptionHandlers);
// transforms all ldarg.x to ldarg.x-1 and output the index of the new ldarg.0's (context calls)
int[] contexts;
var body = TransformLdArgOpcodes(reader.Instructions, realParameters, fakeParameters, out contexts);
// starts at the innermost context call and walks back to the beginning replacing them.
foreach (var startIndex in contexts.OrderByDescending(x => x))
{
var endIndex = startIndex;
while (endIndex < body.Length)
{
endIndex++;
var endOp = body[endIndex];
if (endOp.OpCode == OpCodes.Callvirt && DynamicClassContext.Methods.Contains(endOp.Operand as MethodInfo))
{
break;
}
}
endIndex++;
var ins = body.Skip(startIndex).Take(endIndex - startIndex).ToArray();
ins = ProcessLdContextInstruction(ins, fields, methods, memberName);
body = body.Take(startIndex).Concat(ins).Concat(body.Skip(endIndex)).ToArray();
}
var returnType = methods.ContainsKey(memberName) ? methods[memberName].Builder.ReturnType : null;
if (returnType?.IsValueType == true && returnType != typeof(void) && fakeReturn != returnType)
{
var lbody = body.ToList();
// unbox any return values
foreach (var ret in lbody.Select((s, i) => new { Index = i, Instruction = s }).Where(o => o.Instruction.OpCode == OpCodes.Ret).OrderByDescending(inf => inf.Index).ToArray())
{
lbody.Insert(ret.Index, new Instruction(-1, OpCodes.Unbox_Any)
{
Operand = returnType
});
}
writer.EmitBody(lbody);
}
else
{
writer.EmitBody(body);
}
}
public static void BuildFromExistingMethod(string newMethodName, MethodInfo originalMethod, TypeBuilder builder)
{
var tMethod = builder.DefineMethod(newMethodName, originalMethod.Attributes, originalMethod.CallingConvention,
originalMethod.ReturnType, originalMethod.GetParameters().Select(p => p.ParameterType).ToArray());
var reader = MethodBodyReader.Read(originalMethod);
MethodBodyBuilder bb = new MethodBodyBuilder(tMethod);
bb.DeclareLocals(reader.Locals.Select(l => l.LocalType));
bb.DeclareExceptionHandlers(reader.ExceptionHandlers);
bb.EmitBody(reader.Instructions);
}
public static void BuildFromExistingMethod(string newMethodName, MethodInfo originalMethod, TypeBuilder builder)
{
var tMethod = builder.DefineMethod(newMethodName, originalMethod.Attributes, originalMethod.CallingConvention,
originalMethod.ReturnType, originalMethod.GetParameters().Select(p => p.ParameterType).ToArray());
var reader = MethodBodyReader.Read(originalMethod);
MethodBodyBuilder bb = new MethodBodyBuilder(tMethod.GetILGenerator());
bb.DeclareLocals(reader.Locals.Select(l => l.LocalType));
bb.DeclareExceptionHandlers(reader.ExceptionHandlers);
bb.EmitBody(reader.Instructions);
}