C＃VS2012 stacktrace行错误

Question

In my dll everything was OK for a long of time till today and I have no idea what's going wrong. There is wrong number of exception line appears from today.

So in my method inside dll library I insert a line to throw not supported exception but either I use a debugger or just see exception line in log line is wrong!

Here is an image of part of code :

In fact exception is at 391 line and this was so long time till today. Now in log I see 776 line and the same at debugger. Does anybody has any ideas?

UPDATE 1 05/11/2013

After read all answers ( thanks everybody for them =) ) here is some update:

Is pdb file up to date? I think yes because I removed everything from output folder, rebuild solution and see the same issue. Also I checked creation date of it.

Am I in release mode? I think that not. Here is an image with build configuration

Is code optimized? I created one other test and removed everything below that NotSupportedException but issue is still at the end of the method and line is 397 but not 391 like we have in fact

What is an inner exception? Null

Answer 1

I am almost positive you are running your program in release mode.

When you compile in release mode, the C# compiler will enable optimizations via the assembly's DebuggableAttribute .

The JIT compiler is smart and sees that all of the code between lines 394 and 776 are dead code, impossible to be reached because you're throwing a NotSupportedException .

Additionally, when we're in release mode, the pdb has limited information and JIT optimizations are enabled, so the compiler can't always map exception stacks to the exact location they've happened. It's usually not far off, though, to see where it was thrown.