Add break point to default constructor

Question

I have a class, which has a default constructor inherently.

public class OneRollingFileAppender : RollingFileAppender
{
    #region RollingFileAppender Overrides

    protected override void Append(LoggingEvent loggingEvent)
    {

        GlobalFactory<ILoggingEventParameterManager>.Instance.Apply(loggingEvent);
        base.Append(loggingEvent);
    }

    #endregion
}

Without editing the code, e.g adding a new constructor or property, how can I breakpoint default constructor?

NOTE: There should be a technique which will to find the code in IL or in memory, and then I'd like to set a breakpoint there.

I don't think you can if you don't want to explicitly define a constructor — samyap, Aug 01 '19 at 18:25
@Amy, that code exists in IL, additionally there should be a spot in memory I can break point — johnny 5, Aug 01 '19 at 18:41
@johnny5 I'm aware, but you can't set a breakpoint in **C# code** if that code does not exist. — , Aug 01 '19 at 18:43
Maybe this: https://stackoverflow.com/questions/2617659/how-can-i-set-a-breakpoint-in-referenced-code-in-visual-studio — MikeH, Aug 01 '19 at 18:44
@Amy, I want to set a breakpoint in visual studio, I don't care if its in the C# code, or in Memory or in IL. I only mentioned that I'm using c# for additional context because other languages (like c++) provide support — johnny 5, Aug 01 '19 at 18:46
@MikeH, I was trying that, I couldn't get the breakpoint to hit, maybe it's because its not a normal function — johnny 5, Aug 01 '19 at 18:49
@Postlagerkarte I want to see when a new class of this type is created — johnny 5, Aug 01 '19 at 19:00
@johnny5 In that case I suggest you use a named function breakpoint - if you have more debugging needs use my other answer. — Postlagerkarte, Aug 01 '19 at 19:02
@Amy, this class has to be at some point in the code. There are lines of code in assembly which represent the default constructor, Why do you think this is not possible? — johnny 5, Aug 01 '19 at 19:04
@johnny5 Because I've tried to do this before. You can't set a breakpoint in IL. You keep replying with the suggestion that I don't understand what you're trying to do, and I keep replying that yes, I do. — , Aug 01 '19 at 19:07
Turns out all you have to do is break on function name, and pass the name of the constructor as the function — johnny 5, Aug 02 '19 at 14:21

score 4 · Accepted Answer · edited Jun 20 '20 at 09:12

4

Use WinDbg + SOS Extension

Attach to the process with Windbg (File/Attach to process)
load sos (.loadby sos mscorwks)
Set the breakpoint ( !bpmd mylib.dll Namespace.ClassName..ctor )

If you just want to know when the class is created you can make use of a function breakpoint within Visual Studio. Debug -> New Breakpoint

As Function name you enter your class name.

edited Jun 20 '20 at 09:12

Community

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answered Aug 01 '19 at 18:59

Postlagerkarte

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Yup I've verified this works, if you pass the name of the constructor it will hit the breakpoint – johnny 5 Aug 02 '19 at 14:23

score 2 · Answer 2 · answered Aug 01 '19 at 18:35

2

If you create a variable and assign a value in your class you can place a break point there which will be hit when an instance of the class is created.

public class OneRollingFileAppender : RollingFileAppender
{
  int foo = 0; //Place break point here
}

answered Aug 01 '19 at 18:35

MikeH

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Thanks, but I cannot edit the existing code whatsoever. – johnny 5 Aug 01 '19 at 18:41
This might not have helped OP, but I've just found this and it's super-useful. I'll be adding it to my standard armoury. – Julian Birch Sep 09 '22 at 08:56

score 0 · Answer 3 · edited Aug 01 '19 at 18:45

0

I believe you are using log4net. As you don't have source code so you cannot put break point on your constructor.

edited Aug 01 '19 at 18:45

answered Aug 01 '19 at 18:32

Nitesh Singhal

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score 0 · Answer 4 · answered Aug 01 '19 at 18:56

0

You can't put a breakpoint in compiled code that you don't control. However, with something like ReSharper, you can step into third party code. See: https://www.jetbrains.com/help/resharper/Debugging_Without_Source_Code.html

answered Aug 01 '19 at 18:56

Jonathan

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Add break point to default constructor

4 Answers4