//获取函数的特性
private static AddCustomTrace getTraceAttribute(TypeDefinition type, MethodDefinition method)
{
Type inejectClassType = Type.GetType(type.FullName);
if (inejectClassType == null)
{
throw new NullReferenceException("Class Type is null, Attribute: " + type.FullName);
}
MethodInfo methodinfo = inejectClassType.GetMethod(method.Name);
if (methodinfo == null)
{
throw new NullReferenceException("methodinfo in class " + type.FullName + " is null, method name: " + method.Name);
}
AddCustomTrace attr = (AddCustomTrace)methodinfo.GetCustomAttributes(typeof(AddCustomTrace), true)[0];
if (attr == null)
{
throw new NullReferenceException("attr AddCustomTrace on method " + method.Name + " is null");
}
return(attr);
}
private static void Inject(ModuleDefinition module, MethodDefinition method, TypeDefinition type)
{
if (module == null)
{
throw new ArgumentNullException("input argument invalid, module is null");
}
if (method == null)
{
throw new ArgumentNullException("input argument invalid, method is null");
}
if (type == null)
{
throw new ArgumentNullException("input argument invalid, type is null");
}
//获取方法AddCustomTrace
AddCustomTrace attr = getTraceAttribute(type, method);
//判断功能是否开启
if (attr.enable != true)
{
//Debug.Log(method.Name + " close add custom trace attribute.");
return;
}
//获取特性名称
String name = attr.name;
//更改待注入函数局部变量表
method.Body.InitLocals = true;
var customTraceType = module.ImportReference(typeof(CustomTrace));
var customTraceTypeDef = new VariableDefinition(customTraceType);
method.Body.Variables.Add(customTraceTypeDef);
//准备注入的函数
MethodReference getInstance = module.ImportReference(typeof(APMS).GetMethod("getInstance"));
MethodReference createInstance = module.ImportReference(typeof(APMS).GetMethod("createCustomTrace", new Type[] { typeof(string) }));
MethodReference customTraceStart = module.ImportReference(typeof(CustomTrace).GetMethod("start"));
MethodReference customTraceEnd = module.ImportReference(typeof(CustomTrace).GetMethod("stop"));
//设置一些标签用于语句跳转
Instruction first = method.Body.Instructions[0];
// 开始注入IL代码
var ilProcessor = method.Body.GetILProcessor();
ilProcessor.InsertBefore(first, ilProcessor.Create(OpCodes.Nop));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Call, getInstance));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Ldstr, name));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Callvirt, createInstance));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Stloc, customTraceTypeDef));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Ldloc, customTraceTypeDef));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Callvirt, customTraceStart));
ilProcessor.InsertBefore(first, ilProcessor.Create(OpCodes.Nop));
//在每一个返回的地方插入stop函数，注意插入指令之后，method.Body.Instructions.Count会增加，需要调整i值
for (int i = 0; i < method.Body.Instructions.Count; i++)
{
Instruction ins = method.Body.Instructions[i];
OpCode code = ins.OpCode;
if (ins.OpCode.Equals(OpCodes.Ret) || ins.OpCode.Equals(OpCodes.Throw))
{
//Debug.Log("method: " + method.Name + "i: " + i + " code: " + code);
ilProcessor.InsertBefore(ins, ilProcessor.Create(OpCodes.Nop));
ilProcessor.InsertBefore(ins, Instruction.Create(OpCodes.Ldloc, customTraceTypeDef));
ilProcessor.InsertBefore(ins, Instruction.Create(OpCodes.Callvirt, customTraceEnd));
ilProcessor.InsertBefore(ins, ilProcessor.Create(OpCodes.Nop));
i += 4;
}
}
}
private static void Inject(ModuleDefinition module, MethodDefinition method, TypeDefinition type, AssemblyDefinition assembly)
{
if (module == null)
{
throw new ArgumentNullException("input argument invalid, module is null");
}
if (method == null)
{
throw new ArgumentNullException("input argument invalid, method is null");
}
if (type == null)
{
throw new ArgumentNullException("input argument invalid, type is null");
}
//get AddCustomTrace attribute in method
AddCustomTrace attr = getTraceAttribute(type, method, assembly);
//whether the function is turned on
if (attr.enable != true)
{
return;
}
//get name of attribute
String name = attr.name;
//Change the local variable table of the function to be injected
method.Body.InitLocals = true;
var customTraceType = module.ImportReference(typeof(CustomTrace));
var customTraceTypeDef = new VariableDefinition(customTraceType);
method.Body.Variables.Add(customTraceTypeDef);
//Prepare functions to be injected
MethodReference getInstance = module.ImportReference(typeof(APMS).GetMethod("getInstance"));
MethodReference createInstance = module.ImportReference(typeof(APMS).GetMethod("createCustomTrace", new Type[] { typeof(string) }));
MethodReference customTraceStart = module.ImportReference(typeof(CustomTrace).GetMethod("start"));
MethodReference customTraceEnd = module.ImportReference(typeof(CustomTrace).GetMethod("stop"));
//Set some labels for statement jump
Instruction first = method.Body.Instructions[0];
// start injecting IL code
var ilProcessor = method.Body.GetILProcessor();
ilProcessor.InsertBefore(first, ilProcessor.Create(OpCodes.Nop));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Call, getInstance));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Ldstr, name));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Callvirt, createInstance));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Stloc, customTraceTypeDef));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Ldloc, customTraceTypeDef));
ilProcessor.InsertBefore(first, Instruction.Create(OpCodes.Callvirt, customTraceStart));
ilProcessor.InsertBefore(first, ilProcessor.Create(OpCodes.Nop));
//Insert stop functions at every return. Note that after inserting the instruction,
//method.Body.Instructions.Count increment，and need to adjust the value of i
for (int i = 0; i < method.Body.Instructions.Count; i++)
{
Instruction ins = method.Body.Instructions[i];
OpCode code = ins.OpCode;
if (ins.OpCode.Equals(OpCodes.Ret) || ins.OpCode.Equals(OpCodes.Throw))
{
//Debug.Log("method: " + method.Name + "i: " + i + " code: " + code);
ilProcessor.InsertBefore(ins, ilProcessor.Create(OpCodes.Nop));
ilProcessor.InsertBefore(ins, Instruction.Create(OpCodes.Ldloc, customTraceTypeDef));
ilProcessor.InsertBefore(ins, Instruction.Create(OpCodes.Callvirt, customTraceEnd));
ilProcessor.InsertBefore(ins, ilProcessor.Create(OpCodes.Nop));
i += 4;
}
}
}
