How to determine which methods are called in a method?

Question

I\'d like to list all the methods that are called from a specific method. E.g. if I have the following code:

public void test1() {

   test2();


   test3();         


        

Answer 1

I haven't really worked with Cecil but the HowTo page shows how to enumerate the types, your problem only seems to require looping over the instructions for the ones your after: Call and Load Field. This sample code seems to handle the cases you mentioned but there may be more to it, you should probably check the other Call instructions too. If you make it recursive make sure you keep track of the methods you've already checked.

static void Main(string[] args)
{
    var module = ModuleDefinition.ReadModule("CecilTest.exe");

    var type = module.Types.First(x => x.Name == "A");
    var method = type.Methods.First(x => x.Name == "test");

    PrintMethods(method);
    PrintFields(method);

    Console.ReadLine();
}

public static void PrintMethods(MethodDefinition method)
{
    Console.WriteLine(method.Name);
    foreach (var instruction in method.Body.Instructions)
    {
        if (instruction.OpCode == OpCodes.Call)
        {
            MethodReference methodCall = instruction.Operand as MethodReference;
            if(methodCall != null)
                Console.WriteLine("\t" + methodCall.Name);
        }
    }
}


public static void PrintFields(MethodDefinition method)
{
    Console.WriteLine(method.Name);
    foreach (var instruction in method.Body.Instructions)
    {
        if (instruction.OpCode == OpCodes.Ldfld)
        {
            FieldReference field = instruction.Operand as FieldReference;
            if (field != null)
                Console.WriteLine("\t" + field.Name);
        }
    }
}