lib/error.c

   1 /* Error handler for noninteractive utilities
   2    Copyright (C) 1990-1998, 2000-2005, 2006 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 2, or (at your option)
   8    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 along
  16    with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  20
  21 #if !_LIBC
  22 # include <config.h>
  23 #endif
  24
  25 #include "error.h"
  26
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #if !_LIBC && ENABLE_NLS
  33 # include "gettext.h"
  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 \f
 265 /* Sometimes we want to have at most one error per line.  This
 266    variable controls whether this mode is selected or not.  */
 267 int error_one_per_line;
 268
 269 void
 270 error_at_line (int status, int errnum, const char *file_name,
 271                unsigned int line_number, const char *message, ...)
 272 {
 273   va_list args;
 274
 275   if (error_one_per_line)
 276     {
 277       static const char *old_file_name;
 278       static unsigned int old_line_number;
 279
 280       if (old_line_number == line_number
 281           && (file_name == old_file_name
 282               || strcmp (old_file_name, file_name) == 0))
 283         /* Simply return and print nothing.  */
 284         return;
 285
 286       old_file_name = file_name;
 287       old_line_number = line_number;
 288     }
 289
 290 #if defined _LIBC && defined __libc_ptf_call
 291   /* We do not want this call to be cut short by a thread
 292      cancellation.  Therefore disable cancellation for now.  */
 293   int state = PTHREAD_CANCEL_ENABLE;
 294   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 295                    0);
 296 #endif
 297
 298   fflush (stdout);
 299 #ifdef _LIBC
 300   _IO_flockfile (stderr);
 301 #endif
 302   if (error_print_progname)
 303     (*error_print_progname) ();
 304   else
 305     {
 306 #if _LIBC
 307       __fxprintf (NULL, "%s:", program_name);
 308 #else
 309       fprintf (stderr, "%s:", program_name);
 310 #endif
 311     }
 312
 313 #if _LIBC
 314   __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
 315               file_name, line_number);
 316 #else
 317   fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
 318            file_name, line_number);
 319 #endif
 320
 321   va_start (args, message);
 322   error_tail (status, errnum, message, args);
 323
 324 #ifdef _LIBC
 325   _IO_funlockfile (stderr);
 326 # ifdef __libc_ptf_call
 327   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 328 # endif
 329 #endif
 330 }
 331
 332 #ifdef _LIBC
 333 /* Make the weak alias.  */
 334 # undef error
 335 # undef error_at_line
 336 weak_alias (__error, error)
 337 weak_alias (__error_at_line, error_at_line)
 338 #endif