/* Error handler for noninteractive utilities

   Copyright (C) 1990-2018 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

   <http://www.gnu.org/licenses/>.  */

/* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */

#if !_LIBC

# include <config.h>

#endif

#include "error.h"

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#if !_LIBC && ENABLE_NLS

# include "gettext.h"

# define _(msgid) gettext (msgid)

#endif

#ifdef _LIBC

# include <libintl.h>

# include <stdbool.h>

# include <stdint.h>

# include <wchar.h>

# define mbsrtowcs __mbsrtowcs

# define USE_UNLOCKED_IO 0

# define _GL_ATTRIBUTE_FORMAT_PRINTF(a, b)

# define _GL_ARG_NONNULL(a)

#endif

#if USE_UNLOCKED_IO

# include "unlocked-io.h"

#endif

#ifndef _

# define _(String) String

#endif

/* If NULL, error will flush stdout, then print on stderr the program

   name, a colon and a space.  Otherwise, error will call this

   function without parameters instead.  */

void (*error_print_progname) (void);

/* This variable is incremented each time 'error' is called.  */

unsigned int error_message_count;

#ifdef _LIBC

/* In the GNU C library, there is a predefined variable for this.  */

# define program_name program_invocation_name

# include <errno.h>

# include <limits.h>

# include <libio/libioP.h>

/* In GNU libc we want do not want to use the common name 'error' directly.

   Instead make it a weak alias.  */

extern void __error (int status, int errnum, const char *message, ...)

     __attribute__ ((__format__ (__printf__, 3, 4)));

extern void __error_at_line (int status, int errnum, const char *file_name,

			     unsigned int line_number, const char *message,

			     ...)

     __attribute__ ((__format__ (__printf__, 5, 6)));;

# define error __error

# define error_at_line __error_at_line

# include <libio/iolibio.h>

# define fflush(s) _IO_fflush (s)

# undef putc

# define putc(c, fp) _IO_putc (c, fp)

# include <libc-lock.h>

#else /* not _LIBC */

# include <fcntl.h>

# include <unistd.h>

# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__

/* Get declarations of the native Windows API functions.  */

#  define WIN32_LEAN_AND_MEAN

#  include <windows.h>

/* Get _get_osfhandle.  */

#  include "msvc-nothrow.h"

# endif

/* The gnulib override of fcntl is not needed in this file.  */

# undef fcntl

# if !HAVE_DECL_STRERROR_R

#  ifndef HAVE_DECL_STRERROR_R

"this configure-time declaration test was not run"

#  endif

#  if STRERROR_R_CHAR_P

char *strerror_r ();

#  else

int strerror_r ();

#  endif

# endif

/* The calling program should define program_name and set it to the

   name of the executing program.  */

extern char *program_name;

# if HAVE_STRERROR_R || defined strerror_r

#  define __strerror_r strerror_r

# endif	/* HAVE_STRERROR_R || defined strerror_r */

#endif	/* not _LIBC */

#if !_LIBC

/* Return non-zero if FD is open.  */

static int

is_open (int fd)

{

# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__

  /* On native Windows: The initial state of unassigned standard file

     descriptors is that they are open but point to an INVALID_HANDLE_VALUE.

     There is no fcntl, and the gnulib replacement fcntl does not support

     F_GETFL.  */

  return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;

# else

#  ifndef F_GETFL

#   error Please port fcntl to your platform

#  endif

  return 0 <= fcntl (fd, F_GETFL);

# endif

}

#endif

static void

flush_stdout (void)

{

#if !_LIBC

  int stdout_fd;

# if GNULIB_FREOPEN_SAFER

  /* Use of gnulib's freopen-safer module normally ensures that

       fileno (stdout) == 1

     whenever stdout is open.  */

  stdout_fd = STDOUT_FILENO;

# else

  /* POSIX states that fileno (stdout) after fclose is unspecified.  But in

     practice it is not a problem, because stdout is statically allocated and

     the fd of a FILE stream is stored as a field in its allocated memory.  */

  stdout_fd = fileno (stdout);

# endif

  /* POSIX states that fflush (stdout) after fclose is unspecified; it

     is safe in glibc, but not on all other platforms.  fflush (NULL)

     is always defined, but too draconian.  */

  if (0 <= stdout_fd && is_open (stdout_fd))

#endif

    fflush (stdout);

}

static void

print_errno_message (int errnum)

{

  char const *s;

#if defined HAVE_STRERROR_R || _LIBC

  char errbuf[1024];

# if _LIBC || STRERROR_R_CHAR_P

  s = __strerror_r (errnum, errbuf, sizeof errbuf);

# else

  if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)

    s = errbuf;

  else

    s = 0;

# endif

#else

  s = strerror (errnum);

#endif

#if !_LIBC

  if (! s)

    s = _("Unknown system error");

#endif

#if _LIBC

  __fxprintf (NULL, ": %s", s);

#else

  fprintf (stderr, ": %s", s);

#endif

}

static void _GL_ATTRIBUTE_FORMAT_PRINTF (3, 0) _GL_ARG_NONNULL ((3))

error_tail (int status, int errnum, const char *message, va_list args)

{

#if _LIBC

  if (_IO_fwide (stderr, 0) > 0)

    {

      size_t len = strlen (message) + 1;

      wchar_t *wmessage = NULL;

      mbstate_t st;

      size_t res;

      const char *tmp;

      bool use_malloc = false;

      while (1)

	{

	  if (__libc_use_alloca (len * sizeof (wchar_t)))

	    wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));

	  else

	    {

	      if (!use_malloc)

		wmessage = NULL;

	      wchar_t *p = (wchar_t *) realloc (wmessage,

						len * sizeof (wchar_t));

	      if (p == NULL)

		{

		  free (wmessage);

		  fputws_unlocked (L"out of memory\n", stderr);

		  return;

		}

	      wmessage = p;

	      use_malloc = true;

	    }

	  memset (&st, '\0', sizeof (st));

	  tmp = message;

	  res = mbsrtowcs (wmessage, &tmp, len, &st);

	  if (res != len)

	    break;

	  if (__builtin_expect (len >= SIZE_MAX / sizeof (wchar_t) / 2, 0))

	    {

	      /* This really should not happen if everything is fine.  */

	      res = (size_t) -1;

	      break;

	    }

	  len *= 2;

	}

      if (res == (size_t) -1)

	{

	  /* The string cannot be converted.  */

	  if (use_malloc)

	    {

	      free (wmessage);

	      use_malloc = false;

	    }

	  wmessage = (wchar_t *) L"???";

	}

      __vfwprintf (stderr, wmessage, args);

      if (use_malloc)

	free (wmessage);

    }

  else

#endif

    vfprintf (stderr, message, args);

  va_end (args);

  ++error_message_count;

  if (errnum)

    print_errno_message (errnum);

#if _LIBC

  __fxprintf (NULL, "\n");

#else

  putc ('\n', stderr);

#endif

  fflush (stderr);

  if (status)

    exit (status);

}

/* Print the program name and error message MESSAGE, which is a printf-style

   format string with optional args.

   If ERRNUM is nonzero, print its corresponding system error message.

   Exit with status STATUS if it is nonzero.  */

void

error (int status, int errnum, const char *message, ...)

{

  va_list args;

#if defined _LIBC && defined __libc_ptf_call

  /* We do not want this call to be cut short by a thread

     cancellation.  Therefore disable cancellation for now.  */

  int state = PTHREAD_CANCEL_ENABLE;

  __libc_ptf_call (__pthread_setcancelstate,

		   (PTHREAD_CANCEL_DISABLE, &state), 0);

#endif

  flush_stdout ();

#ifdef _LIBC

  _IO_flockfile (stderr);

#endif

  if (error_print_progname)

    (*error_print_progname) ();

  else

    {

#if _LIBC

      __fxprintf (NULL, "%s: ", program_name);

#else

      fprintf (stderr, "%s: ", program_name);

#endif

    }

  va_start (args, message);

  error_tail (status, errnum, message, args);

  va_end (args);

#ifdef _LIBC

  _IO_funlockfile (stderr);

# ifdef __libc_ptf_call

  __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);

# endif

#endif

}

/* Sometimes we want to have at most one error per line.  This

   variable controls whether this mode is selected or not.  */

int error_one_per_line;

void

error_at_line (int status, int errnum, const char *file_name,

	       unsigned int line_number, const char *message, ...)

{

  va_list args;

  if (error_one_per_line)

    {

      static const char *old_file_name;

      static unsigned int old_line_number;

      if (old_line_number == line_number

	  && (file_name == old_file_name

	      || (old_file_name != NULL

		  && file_name != NULL

		  && strcmp (old_file_name, file_name) == 0)))

	/* Simply return and print nothing.  */

	return;

      old_file_name = file_name;

      old_line_number = line_number;

    }

#if defined _LIBC && defined __libc_ptf_call

  /* We do not want this call to be cut short by a thread

     cancellation.  Therefore disable cancellation for now.  */

  int state = PTHREAD_CANCEL_ENABLE;

  __libc_ptf_call (__pthread_setcancelstate,

		   (PTHREAD_CANCEL_DISABLE, &state),

		   0);

#endif

  flush_stdout ();

#ifdef _LIBC

  _IO_flockfile (stderr);

#endif

  if (error_print_progname)

    (*error_print_progname) ();

  else

    {

#if _LIBC

      __fxprintf (NULL, "%s:", program_name);

#else

      fprintf (stderr, "%s:", program_name);

#endif

    }

#if _LIBC

  __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",

	      file_name, line_number);

#else

  fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",

	   file_name, line_number);

#endif

  va_start (args, message);

  error_tail (status, errnum, message, args);

  va_end (args);

#ifdef _LIBC

  _IO_funlockfile (stderr);

# ifdef __libc_ptf_call

  __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);

# endif

#endif

}

#ifdef _LIBC

/* Make the weak alias.  */

# undef error

# undef error_at_line

weak_alias (__error, error)

weak_alias (__error_at_line, error_at_line)

#endif