How to fix C warning 'implicit declaration of function va_arg'
Problem:
You have C code like
va_list ap;
int mode = va_arg(ap, int);
but when you try to compile it you see a warning message like
main.c:5:12: warning: implicit declaration of function ‘va_arg’ [-Wimplicit-function-declaration]
int mode= va_arg(ap, int);
Solution
Add
#include <stdarg.h>
at the top of the source file where the error occured. This will include the definitions for both va_list
and va_arg
.