Encapsulate function using C11 preprocessor

Question

I am currently working on a project in C in which there are various function that all need become encapsulated in between two other functions. Schematically, it looks like this:

int func1(int arg) {
  prepare();
  doStuff();
  undo();
  return stuff;
}
char func2(int arg1, char* arg2) {
  prepare();
  doOtherStuff();
  undo();
  return results;
}

I've heard the preprocessor is quite powerful, so is it possible to insert the prepare() and undo() functions before and after the actual function body using some preprocessor mumbo-jumbo? I know that it is highly advised not to use the preprocessor if it can be avoided, yet I still am curious whether it is possible.

Cheers.

Answer 1

There you go:

#define MY_MACRO(doStuff) \
{                         \
    prepare();            \
    doStuff               \
    undo();               \
}

Answer 2

Just for the record, an alternative would be to set up some form of function pointer template system:

typedef void stuff_t (void*);

void execute (stuff_t* stuff, void* result)
{
  prepare();  
  stuff(result);
  undo();
}

int func1(int arg) {
  int result;
  execute(do_stuff, &result);
  return result;
}

char func2(int arg1, char* arg2) {
  char result;
  execute(doOtherStuff, &result);
  return result;
}

Whether this is a good idea or not depends on what the code is actually supposed to do and what requirements there are on code re-usability.