New module 'strsignal'.

[gnulib.git] / lib / strsignal.c

diff --git a/lib/strsignal.c b/lib/strsignal.c
new file mode 100644 (file)
index 0000000..2496e2c
--- /dev/null
+++ b/lib/strsignal.c
@@ -0,0 +1,196 @@
+/* Copyright (C) 1991, 1994-2002, 2005, 2008 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _LIBC
+# include <config.h>
+#endif
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _LIBC
+# include <libintl.h>
+#else /* !_LIBC */
+# include "gettext.h"
+# define _(msgid) gettext (msgid)
+# define N_(msgid) gettext_noop (msgid)
+#endif /* _LIBC */
+
+#ifdef _LIBC
+# include <bits/libc-lock.h>
+#else /* !_LIBC */
+# include "lock.h"
+# include "tls.h"
+# define __libc_once_define(CLASS, NAME) gl_once_define (CLASS, NAME)
+# define __libc_once(NAME, INIT) gl_once ((NAME), (INIT))
+# define __libc_key_t gl_tls_key_t
+# define __libc_getspecific(NAME) gl_tls_get ((NAME))
+# define __libc_setspecific(NAME, POINTER) gl_tls_set ((NAME), (POINTER))
+# define __snprintf snprintf
+#endif /* _LIBC */
+
+#ifdef _LIBC
+
+/* Defined in siglist.c.  */
+extern const char *const _sys_siglist[];
+extern const char *const _sys_siglist_internal[] attribute_hidden;
+
+#else /* !_LIBC */
+
+/* NetBSD declares sys_siglist in unistd.h. */
+# include <unistd.h>
+
+# define INTUSE(x) (x)
+
+# if HAVE_DECL_SYS_SIGLIST
+#  undef _sys_siglist
+#  define _sys_siglist sys_siglist
+# else /* !HAVE_DECL_SYS_SIGLIST */
+#  ifndef NSIG
+#   define NSIG 32
+#  endif /* NSIG */
+static const char *_sys_siglist[NSIG];
+# endif /* !HAVE_DECL_SYS_SIGLIST */
+
+#endif /* _LIBC */
+
+static __libc_key_t key;
+
+/* If nonzero the key allocation failed and we should better use a
+   static buffer than fail.  */
+#define BUFFERSIZ      100
+static char local_buf[BUFFERSIZ];
+static char *static_buf;
+
+/* Destructor for the thread-specific data.  */
+static void init (void);
+static void free_key_mem (void *mem);
+static char *getbuffer (void);
+
+
+/* Return a string describing the meaning of the signal number SIGNUM.  */
+char *
+strsignal (int signum)
+{
+  const char *desc;
+  __libc_once_define (static, once);
+
+  /* If we have not yet initialized the buffer do it now.  */
+  __libc_once (once, init);
+
+  if (
+#ifdef SIGRTMIN
+      (signum >= SIGRTMIN && signum <= SIGRTMAX) ||
+#endif
+      signum < 0 || signum >= NSIG
+      || (desc = INTUSE(_sys_siglist)[signum]) == NULL)
+    {
+      char *buffer = getbuffer ();
+      int len;
+#ifdef SIGRTMIN
+      if (signum >= SIGRTMIN && signum <= SIGRTMAX)
+       len = __snprintf (buffer, BUFFERSIZ - 1, _("Real-time signal %d"),
+                         signum - SIGRTMIN);
+      else
+#endif
+       len = __snprintf (buffer, BUFFERSIZ - 1, _("Unknown signal %d"),
+                         signum);
+      if (len >= BUFFERSIZ)
+       buffer = NULL;
+      else
+       buffer[len] = '\0';
+
+      return buffer;
+    }
+
+  return (char *) _(desc);
+}
+
+
+/* Initialize buffer.  */
+static void
+init (void)
+{
+#ifdef _LIBC
+  if (__libc_key_create (&key, free_key_mem))
+    /* Creating the key failed.  This means something really went
+       wrong.  In any case use a static buffer which is better than
+       nothing.  */
+    static_buf = local_buf;
+#else /* !_LIBC */
+  gl_tls_key_init (key, free_key_mem);
+
+# if !HAVE_DECL_SYS_SIGLIST
+  memset (_sys_siglist, 0, NSIG * sizeof *_sys_siglist);
+
+  /* No need to use a do {} while (0) here since init_sig(...) must expand
+     to a complete statement.  (We cannot use the ISO C99 designated array
+     initializer syntax since it is not supported by ANSI C compilers and
+     since some signal numbers might exceed NSIG.)  */
+#  define init_sig(sig, abbrev, desc) \
+  if (sig >= 0 && sig < NSIG) \
+    _sys_siglist[sig] = desc;
+} while (0);
+
+#  include "siglist.h"
+
+#  undef init_sig
+
+# endif /* !HAVE_DECL_SYS_SIGLIST */
+#endif /* !_LIBC */
+}
+
+
+/* Free the thread specific data, this is done if a thread terminates.  */
+static void
+free_key_mem (void *mem)
+{
+  free (mem);
+  __libc_setspecific (key, NULL);
+}
+
+
+/* Return the buffer to be used.  */
+static char *
+getbuffer (void)
+{
+  char *result;
+
+  if (static_buf != NULL)
+    result = static_buf;
+  else
+    {
+      /* We don't use the static buffer and so we have a key.  Use it
+        to get the thread-specific buffer.  */
+      result = __libc_getspecific (key);
+      if (result == NULL)
+       {
+         /* No buffer allocated so far.  */
+         result = malloc (BUFFERSIZ);
+         if (result == NULL)
+           /* No more memory available.  We use the static buffer.  */
+           result = local_buf;
+         else
+           __libc_setspecific (key, result);
+       }
+    }
+
+  return result;
+}