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

Answer 2

In addition to the above, if you find yourself getting frustrated hunting for a bug using valgrind or a similar execution profiler, you should perhaps consider using a static analysis tool, such as lint. Personally, I use PC-LINT, which catches all sorts of these types of bugs.

Answer 3

Try -Wextra

Answer 4

As an alternative to the compiler, I find that running an autoindenter over the code helps find these situations.

In vim for example:

gg=G

Answer 5

After digging deep into the gcc manual:

-Wempty-body
    Warn if an empty body occurs in an `if', `else' or `do while' statement. This warning is also enabled by
-Wextra.

As some other posters wrote, -Wextra should do it

Sample code:

int main(){

        if (0);
                printf("launch missiles");
        return 0;
}


$gcc -Wempty-body foo.c
warn.c: In function ‘main’:
warn.c:5: warning: suggest braces around empty body in an ‘if’ statement