Can gcc accurately catch useless conditionals?

Question

Please examine the following code:

if (foo->bar == NULL);
   foo->bar = strdup(\"Unknown\");

I spent the last part of three hours hun

Answer 1

/* foo.c */
int main() {
   if (1) ; 
   return 0;
}

gcc -Wextra -c foo.c
foo.c: In function ‘main’:
foo.c:2: warning: empty body in an if-statement