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      1 /* Error handler for noninteractive utilities
      2    Copyright (C) 1990-1998, 2000-2007 Free Software Foundation, Inc.
      3    This file is part of the GNU C Library.
      4 
      5    This program is free software: you can redistribute it and/or modify
      6    it under the terms of the GNU General Public License as published by
      7    the Free Software Foundation; either version 3 of the License, or
      8    (at your option) any later version.
      9 
     10    This program is distributed in the hope that it will be useful,
     11    but WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13    GNU General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License
     16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
     17 
     18 /* Written by David MacKenzie <djm (at) gnu.ai.mit.edu>.  */
     19 
     20 #if !_LIBC
     21 # include <config.h>
     22 #endif
     23 
     24 #include "error.h"
     25 
     26 #include <stdarg.h>
     27 #include <stdio.h>
     28 #include <stdlib.h>
     29 #include <string.h>
     30 
     31 #if !_LIBC && ENABLE_NLS
     32 # include "gettext.h"
     33 # define _(msgid) gettext (msgid)
     34 #endif
     35 
     36 #ifdef _LIBC
     37 # include <libintl.h>
     38 # include <stdbool.h>
     39 # include <stdint.h>
     40 # include <wchar.h>
     41 # define mbsrtowcs __mbsrtowcs
     42 #endif
     43 
     44 #if USE_UNLOCKED_IO
     45 # include "unlocked-io.h"
     46 #endif
     47 
     48 #ifndef _
     49 # define _(String) String
     50 #endif
     51 
     52 /* If NULL, error will flush stdout, then print on stderr the program
     53    name, a colon and a space.  Otherwise, error will call this
     54    function without parameters instead.  */
     55 void (*error_print_progname) (void);
     56 
     57 /* This variable is incremented each time `error' is called.  */
     58 unsigned int error_message_count;
     59 
     60 #ifdef _LIBC
     61 /* In the GNU C library, there is a predefined variable for this.  */
     62 
     63 # define program_name program_invocation_name
     64 # include <errno.h>
     65 # include <limits.h>
     66 # include <libio/libioP.h>
     67 
     68 /* In GNU libc we want do not want to use the common name `error' directly.
     69    Instead make it a weak alias.  */
     70 extern void __error (int status, int errnum, const char *message, ...)
     71      __attribute__ ((__format__ (__printf__, 3, 4)));
     72 extern void __error_at_line (int status, int errnum, const char *file_name,
     73 			     unsigned int line_number, const char *message,
     74 			     ...)
     75      __attribute__ ((__format__ (__printf__, 5, 6)));;
     76 # define error __error
     77 # define error_at_line __error_at_line
     78 
     79 # include <libio/iolibio.h>
     80 # define fflush(s) INTUSE(_IO_fflush) (s)
     81 # undef putc
     82 # define putc(c, fp) INTUSE(_IO_putc) (c, fp)
     83 
     84 # include <bits/libc-lock.h>
     85 
     86 #else /* not _LIBC */
     87 
     88 # if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
     89 #  ifndef HAVE_DECL_STRERROR_R
     90 "this configure-time declaration test was not run"
     91 #  endif
     92 char *strerror_r ();
     93 # endif
     94 
     95 /* The calling program should define program_name and set it to the
     96    name of the executing program.  */
     97 extern char *program_name;
     98 
     99 # if HAVE_STRERROR_R || defined strerror_r
    100 #  define __strerror_r strerror_r
    101 # endif	/* HAVE_STRERROR_R || defined strerror_r */
    102 #endif	/* not _LIBC */
    103 
    104 static void
    105 print_errno_message (int errnum)
    106 {
    107   char const *s;
    108 
    109 #if defined HAVE_STRERROR_R || _LIBC
    110   char errbuf[1024];
    111 # if STRERROR_R_CHAR_P || _LIBC
    112   s = __strerror_r (errnum, errbuf, sizeof errbuf);
    113 # else
    114   if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
    115     s = errbuf;
    116   else
    117     s = 0;
    118 # endif
    119 #else
    120   s = strerror (errnum);
    121 #endif
    122 
    123 #if !_LIBC
    124   if (! s)
    125     s = _("Unknown system error");
    126 #endif
    127 
    128 #if _LIBC
    129   __fxprintf (NULL, ": %s", s);
    130 #else
    131   fprintf (stderr, ": %s", s);
    132 #endif
    133 }
    134 
    135 static void
    136 error_tail (int status, int errnum, const char *message, va_list args)
    137 {
    138 #if _LIBC
    139   if (_IO_fwide (stderr, 0) > 0)
    140     {
    141 # define ALLOCA_LIMIT 2000
    142       size_t len = strlen (message) + 1;
    143       wchar_t *wmessage = NULL;
    144       mbstate_t st;
    145       size_t res;
    146       const char *tmp;
    147       bool use_malloc = false;
    148 
    149       while (1)
    150 	{
    151 	  if (__libc_use_alloca (len * sizeof (wchar_t)))
    152 	    wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
    153 	  else
    154 	    {
    155 	      if (!use_malloc)
    156 		wmessage = NULL;
    157 
    158 	      wchar_t *p = (wchar_t *) realloc (wmessage,
    159 						len * sizeof (wchar_t));
    160 	      if (p == NULL)
    161 		{
    162 		  free (wmessage);
    163 		  fputws_unlocked (L"out of memory\n", stderr);
    164 		  return;
    165 		}
    166 	      wmessage = p;
    167 	      use_malloc = true;
    168 	    }
    169 
    170 	  memset (&st, '\0', sizeof (st));
    171 	  tmp = message;
    172 
    173 	  res = mbsrtowcs (wmessage, &tmp, len, &st);
    174 	  if (res != len)
    175 	    break;
    176 
    177 	  if (__builtin_expect (len >= SIZE_MAX / 2, 0))
    178 	    {
    179 	      /* This really should not happen if everything is fine.  */
    180 	      res = (size_t) -1;
    181 	      break;
    182 	    }
    183 
    184 	  len *= 2;
    185 	}
    186 
    187       if (res == (size_t) -1)
    188 	{
    189 	  /* The string cannot be converted.  */
    190 	  if (use_malloc)
    191 	    {
    192 	      free (wmessage);
    193 	      use_malloc = false;
    194 	    }
    195 	  wmessage = (wchar_t *) L"???";
    196 	}
    197 
    198       __vfwprintf (stderr, wmessage, args);
    199 
    200       if (use_malloc)
    201 	free (wmessage);
    202     }
    203   else
    204 #endif
    205     vfprintf (stderr, message, args);
    206   va_end (args);
    207 
    208   ++error_message_count;
    209   if (errnum)
    210     print_errno_message (errnum);
    211 #if _LIBC
    212   __fxprintf (NULL, "\n");
    213 #else
    214   putc ('\n', stderr);
    215 #endif
    216   fflush (stderr);
    217   if (status)
    218     exit (status);
    219 }
    220 
    221 
    222 /* Print the program name and error message MESSAGE, which is a printf-style
    223    format string with optional args.
    224    If ERRNUM is nonzero, print its corresponding system error message.
    225    Exit with status STATUS if it is nonzero.  */
    226 void
    227 error (int status, int errnum, const char *message, ...)
    228 {
    229   va_list args;
    230 
    231 #if defined _LIBC && defined __libc_ptf_call
    232   /* We do not want this call to be cut short by a thread
    233      cancellation.  Therefore disable cancellation for now.  */
    234   int state = PTHREAD_CANCEL_ENABLE;
    235   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
    236 		   0);
    237 #endif
    238 
    239   fflush (stdout);
    240 #ifdef _LIBC
    241   _IO_flockfile (stderr);
    242 #endif
    243   if (error_print_progname)
    244     (*error_print_progname) ();
    245   else
    246     {
    247 #if _LIBC
    248       __fxprintf (NULL, "%s: ", program_name);
    249 #else
    250       fprintf (stderr, "%s: ", program_name);
    251 #endif
    252     }
    253 
    254   va_start (args, message);
    255   error_tail (status, errnum, message, args);
    256 
    257 #ifdef _LIBC
    258   _IO_funlockfile (stderr);
    259 # ifdef __libc_ptf_call
    260   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
    261 # endif
    262 #endif
    263 }
    264 
    265 /* Sometimes we want to have at most one error per line.  This
    267    variable controls whether this mode is selected or not.  */
    268 int error_one_per_line;
    269 
    270 void
    271 error_at_line (int status, int errnum, const char *file_name,
    272 	       unsigned int line_number, const char *message, ...)
    273 {
    274   va_list args;
    275 
    276   if (error_one_per_line)
    277     {
    278       static const char *old_file_name;
    279       static unsigned int old_line_number;
    280 
    281       if (old_line_number == line_number
    282 	  && (file_name == old_file_name
    283 	      || strcmp (old_file_name, file_name) == 0))
    284 	/* Simply return and print nothing.  */
    285 	return;
    286 
    287       old_file_name = file_name;
    288       old_line_number = line_number;
    289     }
    290 
    291 #if defined _LIBC && defined __libc_ptf_call
    292   /* We do not want this call to be cut short by a thread
    293      cancellation.  Therefore disable cancellation for now.  */
    294   int state = PTHREAD_CANCEL_ENABLE;
    295   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
    296 		   0);
    297 #endif
    298 
    299   fflush (stdout);
    300 #ifdef _LIBC
    301   _IO_flockfile (stderr);
    302 #endif
    303   if (error_print_progname)
    304     (*error_print_progname) ();
    305   else
    306     {
    307 #if _LIBC
    308       __fxprintf (NULL, "%s:", program_name);
    309 #else
    310       fprintf (stderr, "%s:", program_name);
    311 #endif
    312     }
    313 
    314 #if _LIBC
    315   __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
    316 	      file_name, line_number);
    317 #else
    318   fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
    319 	   file_name, line_number);
    320 #endif
    321 
    322   va_start (args, message);
    323   error_tail (status, errnum, message, args);
    324 
    325 #ifdef _LIBC
    326   _IO_funlockfile (stderr);
    327 # ifdef __libc_ptf_call
    328   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
    329 # endif
    330 #endif
    331 }
    332 
    333 #ifdef _LIBC
    334 /* Make the weak alias.  */
    335 # undef error
    336 # undef error_at_line
    337 weak_alias (__error, error)
    338 weak_alias (__error_at_line, error_at_line)
    339 #endif
    340