/* Copyright (C) 1991, 1994-2002, 2005, 2008-2014 Free Software Foundation,

   Inc.

   This file is part of the GNU C Library.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef _LIBC

# include <config.h>

#endif

/* Specification.  */

#include <string.h>

#include <signal.h>

#include <stdio.h>

#include <stdlib.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 "glthread/lock.h"

# include "glthread/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. */

# if HAVE_UNISTD_H

#  include <unistd.h>

# endif

# 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 */

#  if !HAVE_DECL__SYS_SIGLIST

static const char *_sys_siglist[NSIG];

#  endif

# 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 - (int) 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;

#  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;

}