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, 51 insertions, 0 deletions

diff --git a/string/test-sig_np.c b/string/test-sig_np.c
new file mode 100644
index 0000000000..8b5117050c
--- /dev/null
+++ b/string/test-sig_np.c
@@ -0,0 +1,51 @@
+/* Test and sigabbrev_np and sigdescr_np.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+#include <signal.h>
+#include <array_length.h>
+
+#include <support/support.h>
+#include <support/check.h>
+
+static const struct test_t
+{
+  int errno;
+  const char *abbrev;
+  const char *descr;
+} tests[] =
+{
+#define N_(name)                      name
+#define init_sig(sig, abbrev, desc)   { sig, abbrev, desc },
+#include <siglist.h>
+#undef init_sig
+};
+
+static int
+do_test (void)
+{
+  for (size_t i = 0; i < array_length (tests); i++)
+    {
+      TEST_COMPARE_STRING (sigabbrev_np (tests[i].errno), tests[i].abbrev);
+      TEST_COMPARE_STRING (sigdescr_np (tests[i].errno), tests[i].descr);
+    }
+
+  return 0;
+}
+
+#include <support/test-driver.c>