Re: obtaining callstack level

From:
"Alf P. Steinbach" <alfps@start.no>
Newsgroups:
comp.lang.c++
Date:
Tue, 25 Apr 2006 03:54:06 +0200
Message-ID:
<4b5dq1Fvjb5jU1@individual.net>
* seannakasone@yahoo.com:

Is there a way to get the callstack level in c++? for example, take
the following code:

void call3() {
   //callstack level would be 3
}

void call2() {
   //callstack level would be 2
   call3();
}

int main() {
   //callstack level would be 1
   call2();
   return 0;
}

And I don't mean obtaining it from using a debugger and looking at the
callstack. I'm mean obtaining it programmatically.


Instrument the functions, that is, add code that maintains a call stack
level count.

That can easily be done via the construction and destruction of a local
object in each function.

For example, off the cuff,

   class CallTracer
   {
   private:
       static std::size_t& theLevel()
       {
           static std::size_t theLevelVariable = 0;
           return theLevelVariable;
       }

   public:
       CallTracer(){ ++theLevel(); }
       ~CallTracer(){ --theLevel(); }
       static std::size_t level() { return theLevel(); }
   };

which you'd use like

   void foo3()
   {
       CallTracer tracer;
       std::cout
          << "foo3, at call level " << CallTracer::level()
          << std::endl;
   }

This counts the calls of functions instrumented this way; if that's not
enough, use a decent debugger.

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