#define DEFER_MERGE(a,b) a##b
#define DEFER_VARNAME(a) DEFER_MERGE(defer_scopevar_, a)
#define DEFER_FUNCNAME(a) DEFER_MERGE(defer_scopefunc_, a)
#define DEFER(BLOCK) void DEFER_FUNCNAME(__LINE__)(int *a) BLOCK; __attribute__((cleanup(DEFER_FUNCNAME(__LINE__)))) int DEFER_VARNAME(__LINE__)

// Usage:
/*
  void dosomething()
  {
    char* data = malloc(100);
    DEFER({ free(data); });
    
    dosomethingwith(data);
  }
*/