1 #ifdef CHECK_FUNCTION_EXISTS
2 
3 #  ifdef __cplusplus
4 extern "C"
5 #  endif
6   char
7   CHECK_FUNCTION_EXISTS(void);
8 #  ifdef __CLASSIC_C__
main()9 int main()
10 {
11   int ac;
12   char* av[];
13 #  else
14 int main(int ac, char* av[])
15 {
16 #  endif
17   CHECK_FUNCTION_EXISTS();
18   if (ac > 1000) {
19     return *av[0];
20   }
21   return 0;
22 }
23 
24 #else /* CHECK_FUNCTION_EXISTS */
25 
26 #  error "CHECK_FUNCTION_EXISTS has to specify the function"
27 
28 #endif /* CHECK_FUNCTION_EXISTS */
29