public static Instruction FindObjectInstance(this CilBody body, Instruction methodInvokeInstruction)
{
if (body == null)
{
throw new ArgumentNullException(nameof(body));
}
if (methodInvokeInstruction == null)
{
throw new ArgumentNullException(nameof(methodInvokeInstruction));
}
if (!(methodInvokeInstruction.Operand is IMethodDefOrRef target) ||
!target.MethodSig.HasThis)
{
throw new ArgumentOutOfRangeException(nameof(methodInvokeInstruction));
}
// instance type is the declaring type when `HasThis` bit is set to true
var type = target.DeclaringType;
var instructions = body.Instructions;
for (var index = instructions.IndexOf(methodInvokeInstruction); index > 0; index--)
{
var instruction = instructions[index];
if (instruction.OpCode == OpCodes.Call && instruction.Operand is IMethodDefOrRef method)
{
if (method.MethodSig.RetType.ToTypeDefOrRef() == type)
{
return(instruction);
}
}
else if (instruction.IsLdloc())
{
var local = instruction.GetLocal(body.Variables);
if (local.Type.ToTypeDefOrRef() == type)
{
var src = body.FindSource(local, instruction);
if (src != null)
{
return(src);
}
}
}
}
return(null);
}
