strcmp behaviour

Question

When I run the following code:

#include 

int main(int argc, char *argv[])
{
    int p = 0;

    p = strcmp(NULL,\"foo\");

    return 0;
}
         


        

Answer 1

You are probably using optimization options when compiling. Since the result of strcmp() in the second snippet is ignored the compiler eliminates this function call and this is why your program does not crash. This call can be eliminated only because strcmp() is an intrinsic function, the compiler is aware that this function does not have any side effects.