Re: [PATCH v2 3/7] string/test-str*cmp: remove stupid_[strcmp, strncmp, wcscmp, wcsncmp].

["H.J. Lu" <hjl.tools@gmail.com>]

On Sun, Jan 9, 2022 at 4:29 PM Noah Goldstein via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> These implementations are incorrect. There may be a mismatch in s1/s2
> before invalid memory but no null CHAR / length boundary.
>
> Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
> ---
>  string/test-strcmp.c  | 35 -----------------------------------
>  string/test-strncmp.c | 34 ----------------------------------
>  2 files changed, 69 deletions(-)
>
> diff --git a/string/test-strcmp.c b/string/test-strcmp.c
> index 3c75076fb8..97d7bf5043 100644
> --- a/string/test-strcmp.c
> +++ b/string/test-strcmp.c
> @@ -34,7 +34,6 @@
>  # define STRLEN wcslen
>  # define MEMCPY wmemcpy
>  # define SIMPLE_STRCMP simple_wcscmp
> -# define STUPID_STRCMP stupid_wcscmp
>  # define CHAR wchar_t
>  # define UCHAR wchar_t
>  # define CHARBYTES 4
> @@ -64,25 +63,6 @@ simple_wcscmp (const wchar_t *s1, const wchar_t *s2)
>    return c1 < c2 ? -1 : 1;
>  }
>
> -int
> -stupid_wcscmp (const wchar_t *s1, const wchar_t *s2)
> -{
> -  size_t ns1 = wcslen (s1) + 1;
> -  size_t ns2 = wcslen (s2) + 1;
> -  size_t n = ns1 < ns2 ? ns1 : ns2;
> -  int ret = 0;
> -
> -  wchar_t c1, c2;
> -
> -  while (n--) {
> -    c1 = *s1++;
> -    c2 = *s2++;
> -    if ((ret = c1 < c2 ? -1 : c1 == c2 ? 0 : 1) != 0)
> -      break;
> -  }
> -  return ret;
> -}
> -
>  #else
>  # include <limits.h>
>
> @@ -92,7 +72,6 @@ stupid_wcscmp (const wchar_t *s1, const wchar_t *s2)
>  # define STRLEN strlen
>  # define MEMCPY memcpy
>  # define SIMPLE_STRCMP simple_strcmp
> -# define STUPID_STRCMP stupid_strcmp
>  # define CHAR char
>  # define UCHAR unsigned char
>  # define CHARBYTES 1
> @@ -113,24 +92,10 @@ simple_strcmp (const char *s1, const char *s2)
>    return ret;
>  }
>
> -int
> -stupid_strcmp (const char *s1, const char *s2)
> -{
> -  size_t ns1 = strlen (s1) + 1;
> -  size_t ns2 = strlen (s2) + 1;
> -  size_t n = ns1 < ns2 ? ns1 : ns2;
> -  int ret = 0;
> -
> -  while (n--)
> -    if ((ret = *(unsigned char *) s1++ - *(unsigned char *) s2++) != 0)
> -      break;
> -  return ret;
> -}
>  #endif
>
>  typedef int (*proto_t) (const CHAR *, const CHAR *);
>
> -IMPL (STUPID_STRCMP, 1)
>  IMPL (SIMPLE_STRCMP, 1)
>  IMPL (STRCMP, 1)
>
> diff --git a/string/test-strncmp.c b/string/test-strncmp.c
> index e7d5edea39..61a283a0af 100644
> --- a/string/test-strncmp.c
> +++ b/string/test-strncmp.c
> @@ -33,7 +33,6 @@
>  # define STRDUP wcsdup
>  # define MEMCPY wmemcpy
>  # define SIMPLE_STRNCMP simple_wcsncmp
> -# define STUPID_STRNCMP stupid_wcsncmp
>  # define CHAR wchar_t
>  # define UCHAR wchar_t
>  # define CHARBYTES 4
> @@ -57,25 +56,6 @@ simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
>    return 0;
>  }
>
> -int
> -stupid_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
> -{
> -  wchar_t c1, c2;
> -  size_t ns1 = wcsnlen (s1, n) + 1, ns2 = wcsnlen (s2, n) + 1;
> -
> -  n = ns1 < n ? ns1 : n;
> -  n = ns2 < n ? ns2 : n;
> -
> -  while (n--)
> -    {
> -      c1 = *s1++;
> -      c2 = *s2++;
> -      if (c1 != c2)
> -       return c1 > c2 ? 1 : -1;
> -    }
> -  return 0;
> -}
> -
>  #else
>  # define L(str) str
>  # define STRNCMP strncmp
> @@ -83,7 +63,6 @@ stupid_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
>  # define STRDUP strdup
>  # define MEMCPY memcpy
>  # define SIMPLE_STRNCMP simple_strncmp
> -# define STUPID_STRNCMP stupid_strncmp
>  # define CHAR char
>  # define UCHAR unsigned char
>  # define CHARBYTES 1
> @@ -101,23 +80,10 @@ simple_strncmp (const char *s1, const char *s2, size_t n)
>    return ret;
>  }
>
> -int
> -stupid_strncmp (const char *s1, const char *s2, size_t n)
> -{
> -  size_t ns1 = strnlen (s1, n) + 1, ns2 = strnlen (s2, n) + 1;
> -  int ret = 0;
> -
> -  n = ns1 < n ? ns1 : n;
> -  n = ns2 < n ? ns2 : n;
> -  while (n-- && (ret = *(unsigned char *) s1++ - * (unsigned char *) s2++) == 0);
> -  return ret;
> -}
> -
>  #endif
>
>  typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
>
> -IMPL (STUPID_STRNCMP, 0)
>  IMPL (SIMPLE_STRNCMP, 0)
>  IMPL (STRNCMP, 1)
>
> --
> 2.25.1
>

LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Thanks.

-- 
H.J.