public static void InstrumentType(Cecil.TypeDefinition type)
{
foreach (var method in type.Methods)
{
if (!method.HasBody)
{
continue;
}
if (method.IsConstructor)
{
continue;
}
if (method.IsStatic)
{
continue;
}
var fieldName = method.GetHotpatchFieldName();
if (type.Fields.Any(f => f.Name == fieldName))
{
Debug.LogWarningFormat("{0} already instrumented", method.FullName);
continue;
}
if (method.HasGenericParameters)
{
Debug.LogWarningFormat("{0} cannot be instrumented - generic parameters", method.FullName);
continue;
}
if (method.Parameters.Any(p => p.IsOut || p.ParameterType.IsByReference))
{
Debug.LogWarningFormat("{0} cannot be instrumented - out/ref arguments", method.FullName);
continue;
}
//Create delegate type and static field in class
var del = type.Module.Import(typeof(RefEmit.DynamicMethod));
var field = new Cecil.FieldDefinition(fieldName, Cecil.FieldAttributes.Private, del);
field.IsStatic = true;
type.Fields.Add(field);
//Instrument method code to check for delegate field and call it instead
var objType = type.Module.TypeSystem.Object;
var voidType = type.Module.TypeSystem.Void;
var objArrayType = type.Module.Import(typeof(object[]));
var dynamicInvoke = type.Module.Import(typeof(RefEmit.DynamicMethod).GetMethod("Invoke", new Type[] { typeof(object), typeof(object[]) }));
var argArrayVar = new Cecil.Cil.VariableDefinition(objArrayType);
method.Body.Variables.Add(argArrayVar);
var ilproc = method.Body.GetILProcessor();
var firstins = ilproc.Body.Instructions[0];
Action <Cecil.Cil.Instruction> emit = (ins) => ilproc.InsertBefore(firstins, ins);
//var writeLineMethod = typeof(UnityEngine.Debug).GetMethod("Log", new Type[]{typeof(string)});
//var writeLine = type.Module.Import(writeLineMethod);
//emit(ilproc.Create(OpCodes.Ldstr, "Hello " + method.FullName));
//emit(ilproc.Create(OpCodes.Call, writeLine));
//Check if delegate field is not null
emit(ilproc.Create(OpCodes.Ldsfld, field));
emit(ilproc.Create(OpCodes.Ldnull));
emit(ilproc.Create(OpCodes.Ceq));
//If null, branch to original function
emit(ilproc.Create(OpCodes.Brtrue, firstins));
//Create object[] args array
emit(ilproc.Create(OpCodes.Ldc_I4, method.Parameters.Count + 1));
emit(ilproc.Create(OpCodes.Newarr, objType));
emit(ilproc.Create(OpCodes.Stloc, argArrayVar));
//Store this at args[0]
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Ldc_I4_0)); //index[0]
emit(ilproc.Create(OpCodes.Ldarg_0)); //arg[0] (this)
emit(ilproc.Create(OpCodes.Stelem_Ref)); //store ref
for (int i = 0; i < method.Parameters.Count; i++)
{
var p = method.Parameters[i];
//Store parameters in args array
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Ldc_I4, i + 1)); //index[i + 1]
emit(ilproc.Create(OpCodes.Ldarg, i + 1)); //arg[i + 1]
if (p.ParameterType.IsValueType)
{
emit(ilproc.Create(OpCodes.Box, p.ParameterType));
}
emit(ilproc.Create(OpCodes.Stelem_Ref)); //store ref
}
//Call delegate
emit(ilproc.Create(OpCodes.Ldsfld, field));
emit(ilproc.Create(OpCodes.Ldarg_0)); //arg[0] (this)
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Callvirt, dynamicInvoke));
//Handle return value
if (method.ReturnType != voidType)
{
if (method.ReturnType.IsValueType)
{
emit(ilproc.Create(OpCodes.Unbox_Any, method.ReturnType));
}
}
else
{
//Discard dynamicInvoke result
emit(ilproc.Create(OpCodes.Pop));
}
//Return
emit(ilproc.Create(OpCodes.Ret));
}
}
public static void InstrumentType(Cecil.TypeDefinition type)
{
foreach (var method in type.Methods) {
if (!method.HasBody) {
continue;
}
if (method.IsConstructor) {
continue;
}
if (method.IsStatic) {
continue;
}
var fieldName = method.GetHotpatchFieldName();
if (type.Fields.Any(f => f.Name == fieldName)) {
Debug.LogWarningFormat("{0} already instrumented", method.FullName);
continue;
}
if (method.HasGenericParameters) {
Debug.LogWarningFormat("{0} cannot be instrumented - generic parameters", method.FullName);
continue;
}
if (method.Parameters.Any(p => p.IsOut || p.ParameterType.IsByReference)) {
Debug.LogWarningFormat("{0} cannot be instrumented - out/ref arguments", method.FullName);
continue;
}
//Create delegate type and static field in class
var del = type.Module.Import(typeof(RefEmit.DynamicMethod));
var field = new Cecil.FieldDefinition(fieldName, Cecil.FieldAttributes.Private, del);
field.IsStatic = true;
type.Fields.Add(field);
//Instrument method code to check for delegate field and call it instead
var objType = type.Module.TypeSystem.Object;
var voidType = type.Module.TypeSystem.Void;
var objArrayType = type.Module.Import(typeof(object[]));
var dynamicInvoke = type.Module.Import(typeof(RefEmit.DynamicMethod).GetMethod("Invoke", new Type[] { typeof(object), typeof(object[]) }));
var argArrayVar = new Cecil.Cil.VariableDefinition(objArrayType);
method.Body.Variables.Add(argArrayVar);
var ilproc = method.Body.GetILProcessor();
var firstins = ilproc.Body.Instructions[0];
Action<Cecil.Cil.Instruction> emit = (ins) => ilproc.InsertBefore(firstins, ins);
//var writeLineMethod = typeof(UnityEngine.Debug).GetMethod("Log", new Type[]{typeof(string)});
//var writeLine = type.Module.Import(writeLineMethod);
//emit(ilproc.Create(OpCodes.Ldstr, "Hello " + method.FullName));
//emit(ilproc.Create(OpCodes.Call, writeLine));
//Check if delegate field is not null
emit(ilproc.Create(OpCodes.Ldsfld, field));
emit(ilproc.Create(OpCodes.Ldnull));
emit(ilproc.Create(OpCodes.Ceq));
//If null, branch to original function
emit(ilproc.Create(OpCodes.Brtrue, firstins));
//Create object[] args array
emit(ilproc.Create(OpCodes.Ldc_I4, method.Parameters.Count + 1));
emit(ilproc.Create(OpCodes.Newarr, objType));
emit(ilproc.Create(OpCodes.Stloc, argArrayVar));
//Store this at args[0]
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Ldc_I4_0)); //index[0]
emit(ilproc.Create(OpCodes.Ldarg_0)); //arg[0] (this)
emit(ilproc.Create(OpCodes.Stelem_Ref)); //store ref
for (int i = 0; i < method.Parameters.Count; i++) {
var p = method.Parameters[i];
//Store parameters in args array
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Ldc_I4, i + 1)); //index[i + 1]
emit(ilproc.Create(OpCodes.Ldarg, i + 1)); //arg[i + 1]
if (p.ParameterType.IsValueType) {
emit(ilproc.Create(OpCodes.Box, p.ParameterType));
}
emit(ilproc.Create(OpCodes.Stelem_Ref)); //store ref
}
//Call delegate
emit(ilproc.Create(OpCodes.Ldsfld, field));
emit(ilproc.Create(OpCodes.Ldarg_0)); //arg[0] (this)
emit(ilproc.Create(OpCodes.Ldloc, argArrayVar));
emit(ilproc.Create(OpCodes.Callvirt, dynamicInvoke));
//Handle return value
if (method.ReturnType != voidType) {
if (method.ReturnType.IsValueType) {
emit(ilproc.Create(OpCodes.Unbox_Any, method.ReturnType));
}
}
else {
//Discard dynamicInvoke result
emit(ilproc.Create(OpCodes.Pop));
}
//Return
emit(ilproc.Create(OpCodes.Ret));
}
}
