aspect c++ tracing function control flow and input

问题:

I am using aspectc++ to generate control flow of the program.

trace.ah:

    #ifndef __trace_ah__
    #define __trace_ah__

    #include <cstdio>
    // Control flow tracing example

    aspect trace {
            // print the function name before execution starts

            pointcut virtual methods() = "% ...::%(...)";

            advice execution (methods()) : before () {
                cout << "entering: " << JoinPoint::signature() << endl;
                // print input parameters**
            }

            advice execution(methods()) : after() {
                // print output parameters**            
                cout << "leaving: " << JoinPoint::signature() << endl;
            }
//prints return values of non void functions 
advice execution("% ...::%(...)" && !"void ...::%(...)") : after() 
{


    JoinPoint::Result res = *tjp->result();
    cout << "leaving " << tjp->signature()<< " << returning value--" << res<<endl;
}
};
    };

    #endif  

Question:

1.How to print the variables itself that are passed as arguments to the functions ?

2.How do I print the input parameters values of each function ?

回答1:

#ifndef __trace_ah__
 #define __trace_ah__

#include <cstdio>
#include <iostream>
using namespace std;

template <int I> struct ArgPrinter 
{
  template <class JP> static inline void work (JP &tjp) {
    ArgPrinter<I - 1>::work (tjp);
    cout << "Arg " << I << ": " << *tjp.template arg<I - 1> () << endl;
  }
};    

template <> struct ArgPrinter<0> 
{
  template <class JP> static inline void work (JP &tjp) {}
};

// Control flow tracing example

    aspect trace {


            pointcut virtual methods() = "% ...::%(...)";

    template <class JP> void print_args (JP &tjp) 
        {
             ArgPrinter<JP::ARGS>::work (tjp);
        }

        advice execution (methods()) : before () 
    {
                cout << "entering: " << JoinPoint::signature() << endl;
            tjp->arg(0);
        print_args (*tjp);


        }

    advice execution("% ...::%(...)" && !"void ...::%(...)") : after() 
    {   
            JoinPoint::Result res = *tjp->result();
            cout << "leaving " << tjp->signature()<< " << returning value--" << res<<endl;
    }


};
  #endif