Warning using -Wconversion and -Ox in gcc 4.5 and 4.6 but not in previous releases

[Cedric Roux]

> But why in previous gcc versions the warning didn't appears. And
> strspn() is a common function in string.h. I don't understand why the
> call to strspn() with correct arguments emits a warning.

Because it's most certainly a bug.

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

int main() {
   size_t x;
   x = strspn("hello","h");
   printf("%zd\n", x);
   return 0;
}

warns too at -O, -O1, -O2, -O3 with -Wconversion. And the value is correctly used and so on.