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c#reflectionattributes
Afnan Bashir
Afnan Bashir

Reputation: 7419

Attributes within Method Body

I know that attributes are not supported inside the method body but i wanted to know maybe someone has work around this. What i am interested in is a technique that allows you to enter custom Attribute inside the method body and onto an two things.

  1. Class Intensiation (Creating Objects Foo foo = new Foo())
  2. When that object calls specific function (foo.bar())

later on I plan to use the metadata of the entered attributes using reflection. I came along a group of people that actually calims that they have extented c# to do so but because of no downloadable I am unable to verify it.

Here is the link to their research paper Freely Annotating c# Please advise me the solution

UPDATE

further with reflection I already know the name of class Foo and its method bar. what the purpose of this is to know that foo called bar() in some method.

for Example

   static void Main()
       {
           [p1inst]  
           ConcretePrototype1 p1 = new ConcretePrototype1("I");

           [p1call]  
           ConcretePrototype1 c1 = (ConcretePrototype1)p1.Clone();
           Console.WriteLine("Cloned: {0}", c1.Id);

           // Wait for user 
           Console.Read();
       }

above is example that illustrate the outcome. At present it can not be done because compiler gives error. but the authors of above mentioned research paper have claimed that they have done this to allow attributes inside the method body

The whole point is to identify that in some method an object of type FOO exists and that object has called bar() or not

Upvotes: 0

Views: 1353

Answers (2)

Tom
Tom

Reputation: 4180

you could add a dictionary with as keys the method names to the class...in a method by reflection you can find out the method name and that way lookup the matching value in the dictionary which would contain your attributes.

I think you don't even need to pre-add the method names in the dictionary as keys; you can put them there the first time the function runs.

Upvotes: 0

sloth
sloth

Reputation: 101052

I think you are on the wrong track. You can't have attributes inside a method. You either didn't read the paper entirely or missed some points.

It speaks of a source-to-source compiler that just translates

public void m() {
    Console.WriteLine("Parallelable code sample");
    [Parallel("Begin of a parallel block")] {
        Console.WriteLine("Code exec by the main thread");
        [Process("First process")] { /∗ Computation here ∗/ }
        [Process] { /∗ Computation here ∗/ }
    }
    Console.WriteLine("Here is sequential");
}

into this C# code:

[Parallel("Parallelable code sample", ACSIndex=1)]
[Process("First process", ACSIndex=2)]
[Process(ACSIndex=3)]
public void m() {
    Console.WriteLine("Parallelable code sample");
    Annotation.Begin(1); { // [Parallel]
        Console.WriteLine("Code exec by the main thread");
        Annotation.Begin(2); /∗ [Process("First process")] ∗/ { · · · }
        Annotation.End(2);
        Annotation.Begin(3); /∗ [Process] ∗/ { · · · }
        Annotation.End(3);
    } 
    Annotation.End(1);
}

So when the method Begin(1) is called on the Annotation class, it will just lookup the method attribute with ASCIndex=1.

To solve your actual problem, you should look into the StackTrace class.

Example:

void Main()
{
    var f = new FooClass();
    f.Foo();
}

class BarClass
{
    public static void Bar()
    {
        var st = new StackTrace();
        var frame = st.GetFrame(1);
        var m = frame.GetMethod();
        Console.WriteLine(String.Format("'{0}' called me from '{1}'", m.DeclaringType.Name, m));
    }
}

class FooClass
{
    public void Foo()
    {
        BarClass.Bar();
    }
}

Output:

'FooClass' called me from 'Void Foo()'

Upvotes: 1

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