How can we know the caller function's name?

Question

In the C language, __FUNCTION__ can be used to get the current function\'s name. But if I define a function named a() and it is called

Answer 1

Try this:

void a();

#ifdef DEBUG
#  define a() a_debug(, __FUNCTION__)
void a_debug(, const char * calledby);
#endif

void b(void)
{
  a();
}

#ifdef DEBUG
#  undef a
#endif

void a()
{
  printf("'%s' called\n", __FUNCTION__);
}

#ifdef DEBUG
void a_debug(, const char * calledby)
{
  printf("'%s' calledby '%s'", __FUNCTION__, calledby);
  a();
}
#endif

If for example is int i, double d, void * p then is i, d, p.

---

Or (less evil ;->> - but more code modding, as each call to a() needs to be touched):

void a((    
#ifdef DEBUG
  , const char * calledby
#endif
  );

void a((    
#ifdef DEBUG
  , const char * calledby
#endif
  )
{
#ifdef DEBUG
  printf("'%s' calledby '%s', __FUNCTION__, calledby);
#endif
  ...
}

...

void b(void)
{
    a(
#ifdef DEBUG
      , __FUNC__
#endif
    );
}

---

__FUNCTION__ is available on GCC (at least?), if using a different C99 compiler replace it with __func__.