C Tutorial/Preprocessor/error
Error directive
specify an error message
//#define USA 1
//#define EUP 1
#include <stdio.h>
#if (!defined (USA) || !defined (EUP))
#error ERROR: NO_CURRENCY rate is specified.
#endif
main()
{
int rs;
rs = 10;
printf ("%d\n", rs);
}ERRORDIRECTIVE0.c:8:5: error: #error ERROR: NO_CURRENCY rate is specified.
