string: Add sigabbrev_np and sigdescr_np

The sigabbrev_np returns the abbreviated signal name (e.g. "HUP" for
SIGHUP) while sigdescr_np returns the string describing the error
number (e.g "Hangup" for SIGHUP).  Different than strsignal,
sigdescr_np does not attempt to translate the return description and
both functions return NULL for an invalid signal number.

They should be used instead of sys_siglist or sys_sigabbrev and they
are both thread and async-signal safe.  They are added as GNU
extensions on string.h header (same as strsignal).

Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 2 insertions, 7 deletions

diff --git a/string/strsignal.c b/string/strsignal.c
index 701ce20e6e..a9b911ce6e 100644
--- a/string/strsignal.c
+++ b/string/strsignal.c
@@ -21,19 +21,14 @@
 #include <string.h>
 #include <libintl.h>
 #include <tls-internal.h>
-#include <array_length.h>
 
 /* Return a string describing the meaning of the signal number SIGNUM.  */
 char *
 strsignal (int signum)
 {
-  const char *desc = NULL;
-
-  if (signum >= 0 && signum <= NSIG && signum < array_length (__sys_siglist))
-    desc = __sys_siglist[signum];
-
+  const char *desc = __sigdescr_np (signum);
   if (desc != NULL)
-    return (char *) _(desc);
+    return _(desc);
 
   struct tls_internal_t *tls_internal = __glibc_tls_internal ();
   free (tls_internal->strsignal_buf);