On 29/05/2021 16:24, Felipe Contreras wrote:
Phillip Wood wrote:
On 27/05/2021 17:36, Felipe Contreras wrote:
ZheNing Hu via GitGitGadget wrote:
[...]
+static int memcasecmp(const void *vs1, const void *vs2, size_t n)
Why void *? We can delcare as char *.
If you look at how this function is used you'll see
int (*cmp_fn)(const void *, const void *, size_t);
cmp_fn = s->sort_flags & REF_SORTING_ICASE
? memcasecmp : memcmp;
Yeah, but why?
We know we are comparing two char *. Presumably the reason is that
memcmp and memcasecmp use void *, but that could be remedied with:
cmp_fn = (int (*)(const char *, const char *, size_t))memcmp;
That way the same cmp_fn could be used for the two cases.
But that is still undefined behavior - the ugly cast just silences any
compiler warning without making the code safe. It calls memcmp using a
pointer of a different type. The type of cmp_fn and the two functions
assigned to it must match.
Best Wishes
Phillip
Either way I don't care particularly much. It also could be possible to
use void * and do the casting in tolower().
(and I personally prefer lower to upper)
We should be using tolower() as that is what POSIX specifies for
strcasecmp() [1] which we are trying to emulate and there are cases[2] where
(tolower(c1) == tolower(c2)) != (toupper(c1) == toupper(c2))
That's true.
