/* Query the name of the current global locale.

   Copyright (C) 2019-2023 Free Software Foundation, Inc.

   This file 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.

   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2019.  */

#include <config.h>

/* Specification.  */

#include "setlocale_null.h"

#include <errno.h>

#include <locale.h>

#include <stdlib.h>

#include <string.h>

#if defined _WIN32 && !defined __CYGWIN__

# include <wchar.h>

#endif

#if !(SETLOCALE_NULL_ALL_MTSAFE && SETLOCALE_NULL_ONE_MTSAFE)

# if defined _WIN32 && !defined __CYGWIN__

#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */

#  include <windows.h>

# elif HAVE_PTHREAD_API

#  include <pthread.h>

#  if HAVE_THREADS_H && HAVE_WEAK_SYMBOLS

#   include <threads.h>

#   pragma weak thrd_exit

#   define c11_threads_in_use() (thrd_exit != NULL)

#  else

#   define c11_threads_in_use() 0

#  endif

# elif HAVE_THREADS_H

#  include <threads.h>

# endif

#endif

/* Use the system's setlocale() function, not the gnulib override, here.  */

#undef setlocale

static const char *

setlocale_null_androidfix (int category)

{

  const char *result = setlocale (category, NULL);

#ifdef __ANDROID__

  if (result == NULL)

    switch (category)

      {

      case LC_CTYPE:

      case LC_NUMERIC:

      case LC_TIME:

      case LC_COLLATE:

      case LC_MONETARY:

      case LC_MESSAGES:

      case LC_ALL:

      case LC_PAPER:

      case LC_NAME:

      case LC_ADDRESS:

      case LC_TELEPHONE:

      case LC_MEASUREMENT:

        result = "C";

        break;

      default:

        break;

      }

#endif

  return result;

}

static int

setlocale_null_unlocked (int category, char *buf, size_t bufsize)

{

#if defined _WIN32 && !defined __CYGWIN__ && defined _MSC_VER

  /* On native Windows, nowadays, the setlocale() implementation is based

     on _wsetlocale() and uses malloc() for the result.  We are better off

     using _wsetlocale() directly.  */

  const wchar_t *result = _wsetlocale (category, NULL);

  if (result == NULL)

    {

      /* CATEGORY is invalid.  */

      if (bufsize > 0)

        /* Return an empty string in BUF.

           This is a convenience for callers that don't want to write explicit

           code for handling EINVAL.  */

        buf[0] = '\0';

      return EINVAL;

    }

  else

    {

      size_t length = wcslen (result);

      if (length < bufsize)

        {

          size_t i;

          /* Convert wchar_t[] -> char[], assuming plain ASCII.  */

          for (i = 0; i <= length; i++)

            buf[i] = result[i];

          return 0;

        }

      else

        {

          if (bufsize > 0)

            {

              /* Return a truncated result in BUF.

                 This is a convenience for callers that don't want to write

                 explicit code for handling ERANGE.  */

              size_t i;

              /* Convert wchar_t[] -> char[], assuming plain ASCII.  */

              for (i = 0; i < bufsize; i++)

                buf[i] = result[i];

              buf[bufsize - 1] = '\0';

            }

          return ERANGE;

        }

    }

#else

  const char *result = setlocale_null_androidfix (category);

  if (result == NULL)

    {

      /* CATEGORY is invalid.  */

      if (bufsize > 0)

        /* Return an empty string in BUF.

           This is a convenience for callers that don't want to write explicit

           code for handling EINVAL.  */

        buf[0] = '\0';

      return EINVAL;

    }

  else

    {

      size_t length = strlen (result);

      if (length < bufsize)

        {

          memcpy (buf, result, length + 1);

          return 0;

        }

      else

        {

          if (bufsize > 0)

            {

              /* Return a truncated result in BUF.

                 This is a convenience for callers that don't want to write

                 explicit code for handling ERANGE.  */

              memcpy (buf, result, bufsize - 1);

              buf[bufsize - 1] = '\0';

            }

          return ERANGE;

        }

    }

#endif

}

#if !(SETLOCALE_NULL_ALL_MTSAFE && SETLOCALE_NULL_ONE_MTSAFE) /* musl libc, macOS, FreeBSD, NetBSD, OpenBSD, AIX, Haiku, Cygwin < 3.4.6 */

/* Use a lock, so that no two threads can invoke setlocale_null_unlocked

   at the same time.  */

/* Prohibit renaming this symbol.  */

# undef gl_get_setlocale_null_lock

# if defined _WIN32 && !defined __CYGWIN__

extern __declspec(dllimport) CRITICAL_SECTION *gl_get_setlocale_null_lock (void);

static int

setlocale_null_with_lock (int category, char *buf, size_t bufsize)

{

  CRITICAL_SECTION *lock = gl_get_setlocale_null_lock ();

  int ret;

  EnterCriticalSection (lock);

  ret = setlocale_null_unlocked (category, buf, bufsize);

  LeaveCriticalSection (lock);

  return ret;

}

# elif HAVE_PTHREAD_API /* musl libc, macOS, FreeBSD, NetBSD, OpenBSD, AIX, Haiku, Cygwin < 3.4.6 */

extern

#  if defined _WIN32 || defined __CYGWIN__

  __declspec(dllimport)

#  endif

  pthread_mutex_t *gl_get_setlocale_null_lock (void);

#  if HAVE_WEAK_SYMBOLS /* musl libc, FreeBSD, NetBSD, OpenBSD, Haiku */

    /* Avoid the need to link with '-lpthread'.  */

#   pragma weak pthread_mutex_lock

#   pragma weak pthread_mutex_unlock

    /* Determine whether libpthread is in use.  */

#   pragma weak pthread_mutexattr_gettype

    /* See the comments in lock.h.  */

#   define pthread_in_use() \

      (pthread_mutexattr_gettype != NULL || c11_threads_in_use ())

#  else

#   define pthread_in_use() 1

#  endif

static int

setlocale_null_with_lock (int category, char *buf, size_t bufsize)

{

  if (pthread_in_use())

    {

      pthread_mutex_t *lock = gl_get_setlocale_null_lock ();

      int ret;

      if (pthread_mutex_lock (lock))

        abort ();

      ret = setlocale_null_unlocked (category, buf, bufsize);

      if (pthread_mutex_unlock (lock))

        abort ();

      return ret;

    }

  else

    return setlocale_null_unlocked (category, buf, bufsize);

}

# elif HAVE_THREADS_H

extern mtx_t *gl_get_setlocale_null_lock (void);

static int

setlocale_null_with_lock (int category, char *buf, size_t bufsize)

{

  mtx_t *lock = gl_get_setlocale_null_lock ();

  int ret;

  if (mtx_lock (lock) != thrd_success)

    abort ();

  ret = setlocale_null_unlocked (category, buf, bufsize);

  if (mtx_unlock (lock) != thrd_success)

    abort ();

  return ret;

}

# endif

#endif

int

setlocale_null_r (int category, char *buf, size_t bufsize)

{

#if SETLOCALE_NULL_ALL_MTSAFE

# if SETLOCALE_NULL_ONE_MTSAFE

  return setlocale_null_unlocked (category, buf, bufsize);

# else

  if (category == LC_ALL)

    return setlocale_null_unlocked (category, buf, bufsize);

  else

    return setlocale_null_with_lock (category, buf, bufsize);

# endif

#else

# if SETLOCALE_NULL_ONE_MTSAFE

  if (category == LC_ALL)

    return setlocale_null_with_lock (category, buf, bufsize);

  else

    return setlocale_null_unlocked (category, buf, bufsize);

# else

  return setlocale_null_with_lock (category, buf, bufsize);

# endif

#endif

}

const char *

setlocale_null (int category)

{

#if SETLOCALE_NULL_ALL_MTSAFE && SETLOCALE_NULL_ONE_MTSAFE

  return setlocale_null_androidfix (category);

#else

  /* This call must be multithread-safe.  To achieve this without using

     thread-local storage:

       1. We use a specific static buffer for each possible CATEGORY

          argument.  So that different threads can call setlocale_mtsafe

          with different CATEGORY arguments, without interfering.

       2. We use a simple strcpy or memcpy to fill this static buffer.

          Filling it through, for example, strcpy + strcat would not be

          guaranteed to leave the buffer's contents intact if another thread

          is currently accessing it.  If necessary, the contents is first

          assembled in a stack-allocated buffer.  */

  if (category == LC_ALL)

    {

# if SETLOCALE_NULL_ALL_MTSAFE

      return setlocale_null_androidfix (LC_ALL);

# else

      char buf[SETLOCALE_NULL_ALL_MAX];

      static char resultbuf[SETLOCALE_NULL_ALL_MAX];

      if (setlocale_null_r (LC_ALL, buf, sizeof (buf)))

        return "C";

      strcpy (resultbuf, buf);

      return resultbuf;

# endif

    }

  else

    {

# if SETLOCALE_NULL_ONE_MTSAFE

      return setlocale_null_androidfix (category);

# else

      enum

        {

          LC_CTYPE_INDEX,

          LC_NUMERIC_INDEX,

          LC_TIME_INDEX,

          LC_COLLATE_INDEX,

          LC_MONETARY_INDEX,

          LC_MESSAGES_INDEX,

#  ifdef LC_PAPER

          LC_PAPER_INDEX,

#  endif

#  ifdef LC_NAME

          LC_NAME_INDEX,

#  endif

#  ifdef LC_ADDRESS

          LC_ADDRESS_INDEX,

#  endif

#  ifdef LC_TELEPHONE

          LC_TELEPHONE_INDEX,

#  endif

#  ifdef LC_MEASUREMENT

          LC_MEASUREMENT_INDEX,

#  endif

#  ifdef LC_IDENTIFICATION

          LC_IDENTIFICATION_INDEX,

#  endif

          LC_INDICES_COUNT

        }

        i;

      char buf[SETLOCALE_NULL_MAX];

      static char resultbuf[LC_INDICES_COUNT][SETLOCALE_NULL_MAX];

      int err;

      err = setlocale_null_r (category, buf, sizeof (buf));

      if (err == EINVAL)

        return NULL;

      if (err)

        return "C";

      switch (category)

        {

        case LC_CTYPE:          i = LC_CTYPE_INDEX;          break;

        case LC_NUMERIC:        i = LC_NUMERIC_INDEX;        break;

        case LC_TIME:           i = LC_TIME_INDEX;           break;

        case LC_COLLATE:        i = LC_COLLATE_INDEX;        break;

        case LC_MONETARY:       i = LC_MONETARY_INDEX;       break;

        case LC_MESSAGES:       i = LC_MESSAGES_INDEX;       break;

#  ifdef LC_PAPER

        case LC_PAPER:          i = LC_PAPER_INDEX;          break;

#  endif

#  ifdef LC_NAME

        case LC_NAME:           i = LC_NAME_INDEX;           break;

#  endif

#  ifdef LC_ADDRESS

        case LC_ADDRESS:        i = LC_ADDRESS_INDEX;        break;

#  endif

#  ifdef LC_TELEPHONE

        case LC_TELEPHONE:      i = LC_TELEPHONE_INDEX;      break;

#  endif

#  ifdef LC_MEASUREMENT

        case LC_MEASUREMENT:    i = LC_MEASUREMENT_INDEX;    break;

#  endif

#  ifdef LC_IDENTIFICATION

        case LC_IDENTIFICATION: i = LC_IDENTIFICATION_INDEX; break;

#  endif

        default:

          /* If you get here, a #ifdef LC_xxx is missing.  */

          abort ();

        }

      strcpy (resultbuf[i], buf);

      return resultbuf[i];

# endif

    }

#endif

}