[v5,08/13] string: Simplify strerror_r
Commit Message
Use snprintf instead of mempcpy plus itoa_word and remove unused
definitions. There is no potential for infinite recursion because
snprintf only use strerror_r for the %m specifier.
Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.
---
string/_strerror.c | 41 ++----------------------
sysdeps/mach/_strerror.c | 67 +++-------------------------------------
2 files changed, 7 insertions(+), 101 deletions(-)
Comments
On 6/19/20 9:43 AM, Adhemerval Zanella wrote:
> Use snprintf instead of mempcpy plus itoa_word and remove unused
> definitions. There is no potential for infinite recursion because
> snprintf only use strerror_r for the %m specifier.
>
> Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
> and s390x-linux-gnu.
OK for master. I like the simplification and it makes sense to me.
No regressions on x86_64 and i686.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> ---
> string/_strerror.c | 41 ++----------------------
> sysdeps/mach/_strerror.c | 67 +++-------------------------------------
> 2 files changed, 7 insertions(+), 101 deletions(-)
>
> diff --git a/string/_strerror.c b/string/_strerror.c
> index 01226e3d4b..da3b22f5b1 100644
> --- a/string/_strerror.c
> +++ b/string/_strerror.c
> @@ -15,22 +15,10 @@
> License along with the GNU C Library; if not, see
> <https://www.gnu.org/licenses/>. */
>
> +#include <string.h>
> #include <libintl.h>
> -#include <stdbool.h>
> #include <stdio.h>
> #include <stdlib.h>
> -#include <string.h>
> -#include <sys/param.h>
> -#include <_itoa.h>
> -
> -/* It is critical here that we always use the `dcgettext' function for
> - the message translation. Since <libintl.h> only defines the macro
> - `dgettext' to use `dcgettext' for optimizing programs this is not
> - always guaranteed. */
> -#ifndef dgettext
> -# include <locale.h> /* We need LC_MESSAGES. */
> -# define dgettext(domainname, msgid) dcgettext (domainname, msgid, LC_MESSAGES)
> -#endif
OK.
>
> /* Return a string describing the errno code in ERRNUM. */
> char *
> @@ -39,32 +27,7 @@ __strerror_r (int errnum, char *buf, size_t buflen)
> char *err = (char *) __get_errlist (errnum);
> if (__glibc_unlikely (err == NULL))
> {
> - /* Buffer we use to print the number in. For a maximum size for
> - `int' of 8 bytes we never need more than 20 digits. */
> - char numbuf[21];
> - const char *unk = _("Unknown error ");
> - size_t unklen = strlen (unk);
> - char *p, *q;
> - bool negative = errnum < 0;
> -
> - numbuf[20] = '\0';
> - p = _itoa_word (abs (errnum), &numbuf[20], 10, 0);
> -
> - /* Now construct the result while taking care for the destination
> - buffer size. */
> - q = __mempcpy (buf, unk, MIN (unklen, buflen));
> - if (negative && unklen < buflen)
> - {
> - *q++ = '-';
> - ++unklen;
> - }
> - if (unklen < buflen)
> - memcpy (q, p, MIN ((size_t) (&numbuf[21] - p), buflen - unklen));
> -
> - /* Terminate the string in any case. */
> - if (buflen > 0)
> - buf[buflen - 1] = '\0';
> -
> + __snprintf (buf, buflen, "%s%d", _("Unknown error "), errnum);
OK. No %m specifier.
> return buf;
> }
>
> diff --git a/sysdeps/mach/_strerror.c b/sysdeps/mach/_strerror.c
> index d932b1bd58..399de330d9 100644
> --- a/sysdeps/mach/_strerror.c
> +++ b/sysdeps/mach/_strerror.c
> @@ -15,22 +15,12 @@
> License along with the GNU C Library; if not, see
> <https://www.gnu.org/licenses/>. */
>
> +#include <string.h>
> #include <libintl.h>
> #include <stdio.h>
> #include <string.h>
> #include <mach/error.h>
> #include <errorlib.h>
> -#include <sys/param.h>
> -#include <_itoa.h>
> -
> -/* It is critical here that we always use the `dcgettext' function for
> - the message translation. Since <libintl.h> only defines the macro
> - `dgettext' to use `dcgettext' for optimizing programs this is not
> - always guaranteed. */
> -#ifndef dgettext
> -# include <locale.h> /* We need LC_MESSAGES. */
> -# define dgettext(domainname, msgid) dcgettext (domainname, msgid, LC_MESSAGES)
> -#endif
>
OK.
> /* Return a string describing the errno code in ERRNUM. */
> char *
> @@ -50,26 +40,8 @@ __strerror_r (int errnum, char *buf, size_t buflen)
>
> if (system > err_max_system || ! __mach_error_systems[system].bad_sub)
> {
> - /* Buffer we use to print the number in. For a maximum size for
> - `int' of 8 bytes we never need more than 20 digits. */
> - char numbuf[21];
> - const char *unk = _("Error in unknown error system: ");
> - const size_t unklen = strlen (unk);
> - char *p, *q;
> -
> - numbuf[20] = '\0';
> - p = _itoa_word (errnum, &numbuf[20], 16, 1);
> -
> - /* Now construct the result while taking care for the destination
> - buffer size. */
> - q = __mempcpy (buf, unk, MIN (unklen, buflen));
> - if (unklen < buflen)
> - memcpy (q, p, MIN (&numbuf[21] - p, buflen - unklen));
> -
> - /* Terminate the string in any case. */
> - if (buflen > 0)
> - buf[buflen - 1] = '\0';
> -
> + __snprintf (buf, buflen, "%s: %d", _("Error in unknown error system: "),
> + errnum);
OK. No %m.
> return buf;
> }
>
> @@ -80,37 +52,8 @@ __strerror_r (int errnum, char *buf, size_t buflen)
>
> if (code >= es->subsystem[sub].max_code)
> {
> - /* Buffer we use to print the number in. For a maximum size for
> - `int' of 8 bytes we never need more than 20 digits. */
> - char numbuf[21];
> - const char *unk = _("Unknown error ");
> - const size_t unklen = strlen (unk);
> - char *p, *q;
> - size_t len = strlen (es->subsystem[sub].subsys_name);
> -
> - numbuf[20] = '\0';
> - p = _itoa_word (errnum, &numbuf[20], 10, 0);
> -
> - /* Now construct the result while taking care for the destination
> - buffer size. */
> - q = __mempcpy (buf, unk, MIN (unklen, buflen));
> - if (unklen < buflen)
> - {
> - q = __mempcpy (q, es->subsystem[sub].subsys_name,
> - MIN (len, buflen - unklen));
> - if (unklen + len < buflen)
> - {
> - *q++ = ' ';
> - if (unklen + len + 1 < buflen)
> - memcpy (q, p,
> - MIN (&numbuf[21] - p, buflen - unklen - len - 1));
> - }
> - }
> -
> - /* Terminate the string in any case. */
> - if (buflen > 0)
> - buf[buflen - 1] = '\0';
> -
> + __snprintf (buf, buflen, "%s%s %d", _("Unknown error "),
> + es->subsystem[sub].subsys_name, errnum);
OK. Perfect.
> return buf;
> }
>
>
@@ -15,22 +15,10 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <string.h>
#include <libintl.h>
-#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
-#include <string.h>
-#include <sys/param.h>
-#include <_itoa.h>
-
-/* It is critical here that we always use the `dcgettext' function for
- the message translation. Since <libintl.h> only defines the macro
- `dgettext' to use `dcgettext' for optimizing programs this is not
- always guaranteed. */
-#ifndef dgettext
-# include <locale.h> /* We need LC_MESSAGES. */
-# define dgettext(domainname, msgid) dcgettext (domainname, msgid, LC_MESSAGES)
-#endif
/* Return a string describing the errno code in ERRNUM. */
char *
@@ -39,32 +27,7 @@ __strerror_r (int errnum, char *buf, size_t buflen)
char *err = (char *) __get_errlist (errnum);
if (__glibc_unlikely (err == NULL))
{
- /* Buffer we use to print the number in. For a maximum size for
- `int' of 8 bytes we never need more than 20 digits. */
- char numbuf[21];
- const char *unk = _("Unknown error ");
- size_t unklen = strlen (unk);
- char *p, *q;
- bool negative = errnum < 0;
-
- numbuf[20] = '\0';
- p = _itoa_word (abs (errnum), &numbuf[20], 10, 0);
-
- /* Now construct the result while taking care for the destination
- buffer size. */
- q = __mempcpy (buf, unk, MIN (unklen, buflen));
- if (negative && unklen < buflen)
- {
- *q++ = '-';
- ++unklen;
- }
- if (unklen < buflen)
- memcpy (q, p, MIN ((size_t) (&numbuf[21] - p), buflen - unklen));
-
- /* Terminate the string in any case. */
- if (buflen > 0)
- buf[buflen - 1] = '\0';
-
+ __snprintf (buf, buflen, "%s%d", _("Unknown error "), errnum);
return buf;
}
@@ -15,22 +15,12 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <string.h>
#include <libintl.h>
#include <stdio.h>
#include <string.h>
#include <mach/error.h>
#include <errorlib.h>
-#include <sys/param.h>
-#include <_itoa.h>
-
-/* It is critical here that we always use the `dcgettext' function for
- the message translation. Since <libintl.h> only defines the macro
- `dgettext' to use `dcgettext' for optimizing programs this is not
- always guaranteed. */
-#ifndef dgettext
-# include <locale.h> /* We need LC_MESSAGES. */
-# define dgettext(domainname, msgid) dcgettext (domainname, msgid, LC_MESSAGES)
-#endif
/* Return a string describing the errno code in ERRNUM. */
char *
@@ -50,26 +40,8 @@ __strerror_r (int errnum, char *buf, size_t buflen)
if (system > err_max_system || ! __mach_error_systems[system].bad_sub)
{
- /* Buffer we use to print the number in. For a maximum size for
- `int' of 8 bytes we never need more than 20 digits. */
- char numbuf[21];
- const char *unk = _("Error in unknown error system: ");
- const size_t unklen = strlen (unk);
- char *p, *q;
-
- numbuf[20] = '\0';
- p = _itoa_word (errnum, &numbuf[20], 16, 1);
-
- /* Now construct the result while taking care for the destination
- buffer size. */
- q = __mempcpy (buf, unk, MIN (unklen, buflen));
- if (unklen < buflen)
- memcpy (q, p, MIN (&numbuf[21] - p, buflen - unklen));
-
- /* Terminate the string in any case. */
- if (buflen > 0)
- buf[buflen - 1] = '\0';
-
+ __snprintf (buf, buflen, "%s: %d", _("Error in unknown error system: "),
+ errnum);
return buf;
}
@@ -80,37 +52,8 @@ __strerror_r (int errnum, char *buf, size_t buflen)
if (code >= es->subsystem[sub].max_code)
{
- /* Buffer we use to print the number in. For a maximum size for
- `int' of 8 bytes we never need more than 20 digits. */
- char numbuf[21];
- const char *unk = _("Unknown error ");
- const size_t unklen = strlen (unk);
- char *p, *q;
- size_t len = strlen (es->subsystem[sub].subsys_name);
-
- numbuf[20] = '\0';
- p = _itoa_word (errnum, &numbuf[20], 10, 0);
-
- /* Now construct the result while taking care for the destination
- buffer size. */
- q = __mempcpy (buf, unk, MIN (unklen, buflen));
- if (unklen < buflen)
- {
- q = __mempcpy (q, es->subsystem[sub].subsys_name,
- MIN (len, buflen - unklen));
- if (unklen + len < buflen)
- {
- *q++ = ' ';
- if (unklen + len + 1 < buflen)
- memcpy (q, p,
- MIN (&numbuf[21] - p, buflen - unklen - len - 1));
- }
- }
-
- /* Terminate the string in any case. */
- if (buflen > 0)
- buf[buflen - 1] = '\0';
-
+ __snprintf (buf, buflen, "%s%s %d", _("Unknown error "),
+ es->subsystem[sub].subsys_name, errnum);
return buf;
}