How are variable arguments implemented in gcc?

Question

int max(int n, ...)

I am using cdecl calling convention where the caller cleans up the variable after the callee returns.

I a

Answer 1

int max(int n, const char *msg,...)
{
va_list args;
char buffer[1024];
va_start(args, msg);
nb_char_written = vsnprintf(buffer, 1024, msg, args);
va_end(args);
printf("(%d):%s\n",n,buffer);
}