misc/error.c

   1 /* Error handler for noninteractive utilities
   2    Copyright (C) 1990-1998, 2000-2006, 2011 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #ifdef _LIBC
  32 # include <libintl.h>
  33 # include <stdbool.h>
  34 # include <stdint.h>
  35 # include <wchar.h>
  36 # define mbsrtowcs __mbsrtowcs
  37 #endif
  38
  39 #include "error.h"
  40
  41 #ifndef _
  42 # define _(String) String
  43 #endif
  44
  45 /* If NULL, error will flush stdout, then print on stderr the program
  46    name, a colon and a space.  Otherwise, error will call this
  47    function without parameters instead.  */
  48 void (*error_print_progname) (void);
  49
  50 /* This variable is incremented each time `error' is called.  */
  51 unsigned int error_message_count;
  52
  53 #ifdef _LIBC
  54 /* In the GNU C library, there is a predefined variable for this.  */
  55
  56 # define program_name program_invocation_name
  57 # include <errno.h>
  58 # include <limits.h>
  59 # include <libio/libioP.h>
  60
  61 /* In GNU libc we want do not want to use the common name `error' directly.
  62    Instead make it a weak alias.  */
  63 extern void __error (int status, int errnum, const char *message, ...)
  64      __attribute__ ((__format__ (__printf__, 3, 4)));
  65 extern void __error_at_line (int status, int errnum, const char *file_name,
  66                              unsigned int line_number, const char *message,
  67                              ...)
  68      __attribute__ ((__format__ (__printf__, 5, 6)));;
  69 # define error __error
  70 # define error_at_line __error_at_line
  71
  72 # include <libio/iolibio.h>
  73 # define fflush(s) INTUSE(_IO_fflush) (s)
  74 # undef putc
  75 # define putc(c, fp) INTUSE(_IO_putc) (c, fp)
  76
  77 # include <bits/libc-lock.h>
  78
  79 #else /* not _LIBC */
  80
  81 # if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
  82 #  ifndef HAVE_DECL_STRERROR_R
  83 "this configure-time declaration test was not run"
  84 #  endif
  85 char *strerror_r ();
  86 # endif
  87
  88 /* The calling program should define program_name and set it to the
  89    name of the executing program.  */
  90 extern char *program_name;
  91
  92 # if HAVE_STRERROR_R || defined strerror_r
  93 #  define __strerror_r strerror_r
  94 # endif /* HAVE_STRERROR_R || defined strerror_r */
  95 #endif  /* not _LIBC */
  96
  97 static void
  98 print_errno_message (int errnum)
  99 {
 100   char const *s;
 101
 102 #if defined HAVE_STRERROR_R || _LIBC
 103   char errbuf[1024];
 104 # if STRERROR_R_CHAR_P || _LIBC
 105   s = __strerror_r (errnum, errbuf, sizeof errbuf);
 106 # else
 107   if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
 108     s = errbuf;
 109   else
 110     s = 0;
 111 # endif
 112 #else
 113   s = strerror (errnum);
 114 #endif
 115
 116 #if !_LIBC
 117   if (! s)
 118     s = _("Unknown system error");
 119 #endif
 120
 121 #if _LIBC
 122   __fxprintf (NULL, ": %s", s);
 123 #else
 124   fprintf (stderr, ": %s", s);
 125 #endif
 126 }
 127
 128 static void
 129 error_tail (int status, int errnum, const char *message, va_list args)
 130 {
 131 #if _LIBC
 132   if (_IO_fwide (stderr, 0) > 0)
 133     {
 134 # define ALLOCA_LIMIT 2000
 135       size_t len = strlen (message) + 1;
 136       wchar_t *wmessage = NULL;
 137       mbstate_t st;
 138       size_t res;
 139       const char *tmp;
 140       bool use_malloc = false;
 141
 142       while (1)
 143         {
 144           if (__libc_use_alloca (len * sizeof (wchar_t)))
 145             wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
 146           else
 147             {
 148               if (!use_malloc)
 149                 wmessage = NULL;
 150
 151               wchar_t *p = (wchar_t *) realloc (wmessage,
 152                                                 len * sizeof (wchar_t));
 153               if (p == NULL)
 154                 {
 155                   free (wmessage);
 156                   fputws_unlocked (L"out of memory\n", stderr);
 157                   return;
 158                 }
 159               wmessage = p;
 160               use_malloc = true;
 161             }
 162
 163           memset (&st, '\0', sizeof (st));
 164           tmp = message;
 165
 166           res = mbsrtowcs (wmessage, &tmp, len, &st);
 167           if (res != len)
 168             break;
 169
 170           if (__builtin_expect (len >= SIZE_MAX / 2, 0))
 171             {
 172               /* This really should not happen if everything is fine.  */
 173               res = (size_t) -1;
 174               break;
 175             }
 176
 177           len *= 2;
 178         }
 179
 180       if (res == (size_t) -1)
 181         {
 182           /* The string cannot be converted.  */
 183           if (use_malloc)
 184             {
 185               free (wmessage);
 186               use_malloc = false;
 187             }
 188           wmessage = (wchar_t *) L"???";
 189         }
 190
 191       __vfwprintf (stderr, wmessage, args);
 192
 193       if (use_malloc)
 194         free (wmessage);
 195     }
 196   else
 197 #endif
 198     vfprintf (stderr, message, args);
 199   va_end (args);
 200
 201   ++error_message_count;
 202   if (errnum)
 203     print_errno_message (errnum);
 204 #if _LIBC
 205   __fxprintf (NULL, "\n");
 206 #else
 207   putc ('\n', stderr);
 208 #endif
 209   fflush (stderr);
 210   if (status)
 211     exit (status);
 212 }
 213
 214
 215 /* Print the program name and error message MESSAGE, which is a printf-style
 216    format string with optional args.
 217    If ERRNUM is nonzero, print its corresponding system error message.
 218    Exit with status STATUS if it is nonzero.  */
 219 void
 220 error (int status, int errnum, const char *message, ...)
 221 {
 222   va_list args;
 223
 224 #if defined _LIBC && defined __libc_ptf_call
 225   /* We do not want this call to be cut short by a thread
 226      cancellation.  Therefore disable cancellation for now.  */
 227   int state = PTHREAD_CANCEL_ENABLE;
 228   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 229                    0);
 230 #endif
 231
 232   fflush (stdout);
 233 #ifdef _LIBC
 234   _IO_flockfile (stderr);
 235 #endif
 236   if (error_print_progname)
 237     (*error_print_progname) ();
 238   else
 239     {
 240 #if _LIBC
 241       __fxprintf (NULL, "%s: ", program_name);
 242 #else
 243       fprintf (stderr, "%s: ", program_name);
 244 #endif
 245     }
 246
 247   va_start (args, message);
 248   error_tail (status, errnum, message, args);
 249
 250 #ifdef _LIBC
 251   _IO_funlockfile (stderr);
 252 # ifdef __libc_ptf_call
 253   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 254 # endif
 255 #endif
 256 }
 257 \f
 258 /* Sometimes we want to have at most one error per line.  This
 259    variable controls whether this mode is selected or not.  */
 260 int error_one_per_line;
 261
 262 void
 263 error_at_line (int status, int errnum, const char *file_name,
 264                unsigned int line_number, const char *message, ...)
 265 {
 266   va_list args;
 267
 268   if (error_one_per_line)
 269     {
 270       static const char *old_file_name;
 271       static unsigned int old_line_number;
 272
 273       if (old_line_number == line_number
 274           && (file_name == old_file_name
 275               || (old_file_name != NULL
 276                   && file_name != NULL
 277                   && strcmp (old_file_name, file_name) == 0)))
 278         /* Simply return and print nothing.  */
 279         return;
 280
 281       old_file_name = file_name;
 282       old_line_number = line_number;
 283     }
 284
 285 #if defined _LIBC && defined __libc_ptf_call
 286   /* We do not want this call to be cut short by a thread
 287      cancellation.  Therefore disable cancellation for now.  */
 288   int state = PTHREAD_CANCEL_ENABLE;
 289   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 290                    0);
 291 #endif
 292
 293   fflush (stdout);
 294 #ifdef _LIBC
 295   _IO_flockfile (stderr);
 296 #endif
 297   if (error_print_progname)
 298     (*error_print_progname) ();
 299   else
 300     {
 301 #if _LIBC
 302       __fxprintf (NULL, "%s:", program_name);
 303 #else
 304       fprintf (stderr, "%s:", program_name);
 305 #endif
 306     }
 307
 308 #if _LIBC
 309   __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
 310               file_name, line_number);
 311 #else
 312   fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
 313            file_name, line_number);
 314 #endif
 315
 316   va_start (args, message);
 317   error_tail (status, errnum, message, args);
 318
 319 #ifdef _LIBC
 320   _IO_funlockfile (stderr);
 321 # ifdef __libc_ptf_call
 322   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 323 # endif
 324 #endif
 325 }
 326
 327 #ifdef _LIBC
 328 /* Make the weak alias.  */
 329 # undef error
 330 # undef error_at_line
 331 weak_alias (__error, error)
 332 weak_alias (__error_at_line, error_at_line)
 333 #endif