misc/error.c

   1 /* Error handler for noninteractive utilities
   2    Copyright (C) 1990-2013 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #ifdef _LIBC
  31 # include <libintl.h>
  32 # include <stdbool.h>
  33 # include <stdint.h>
  34 # include <wchar.h>
  35 # define mbsrtowcs __mbsrtowcs
  36 #endif
  37
  38 #include "error.h"
  39
  40 #ifndef _
  41 # define _(String) String
  42 #endif
  43
  44 /* If NULL, error will flush stdout, then print on stderr the program
  45    name, a colon and a space.  Otherwise, error will call this
  46    function without parameters instead.  */
  47 void (*error_print_progname) (void);
  48
  49 /* This variable is incremented each time `error' is called.  */
  50 unsigned int error_message_count;
  51
  52 #ifdef _LIBC
  53 /* In the GNU C library, there is a predefined variable for this.  */
  54
  55 # define program_name program_invocation_name
  56 # include <errno.h>
  57 # include <limits.h>
  58 # include <libio/libioP.h>
  59
  60 /* In GNU libc we want do not want to use the common name `error' directly.
  61    Instead make it a weak alias.  */
  62 extern void __error (int status, int errnum, const char *message, ...)
  63      __attribute__ ((__format__ (__printf__, 3, 4)));
  64 extern void __error_at_line (int status, int errnum, const char *file_name,
  65                              unsigned int line_number, const char *message,
  66                              ...)
  67      __attribute__ ((__format__ (__printf__, 5, 6)));;
  68 # define error __error
  69 # define error_at_line __error_at_line
  70
  71 # include <libio/iolibio.h>
  72 # define fflush(s) _IO_fflush (s)
  73 # undef putc
  74 # define putc(c, fp) _IO_putc (c, fp)
  75
  76 # include <bits/libc-lock.h>
  77
  78 #else /* not _LIBC */
  79
  80 # if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
  81 #  ifndef HAVE_DECL_STRERROR_R
  82 "this configure-time declaration test was not run"
  83 #  endif
  84 char *strerror_r ();
  85 # endif
  86
  87 /* The calling program should define program_name and set it to the
  88    name of the executing program.  */
  89 extern char *program_name;
  90
  91 # if HAVE_STRERROR_R || defined strerror_r
  92 #  define __strerror_r strerror_r
  93 # endif /* HAVE_STRERROR_R || defined strerror_r */
  94 #endif  /* not _LIBC */
  95
  96 static void
  97 print_errno_message (int errnum)
  98 {
  99   char const *s;
 100
 101 #if defined HAVE_STRERROR_R || _LIBC
 102   char errbuf[1024];
 103 # if STRERROR_R_CHAR_P || _LIBC
 104   s = __strerror_r (errnum, errbuf, sizeof errbuf);
 105 # else
 106   if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
 107     s = errbuf;
 108   else
 109     s = 0;
 110 # endif
 111 #else
 112   s = strerror (errnum);
 113 #endif
 114
 115 #if !_LIBC
 116   if (! s)
 117     s = _("Unknown system error");
 118 #endif
 119
 120 #if _LIBC
 121   __fxprintf (NULL, ": %s", s);
 122 #else
 123   fprintf (stderr, ": %s", s);
 124 #endif
 125 }
 126
 127 static void
 128 error_tail (int status, int errnum, const char *message, va_list args)
 129 {
 130 #if _LIBC
 131   if (_IO_fwide (stderr, 0) > 0)
 132     {
 133       size_t len = strlen (message) + 1;
 134       wchar_t *wmessage = NULL;
 135       mbstate_t st;
 136       size_t res;
 137       const char *tmp;
 138       bool use_malloc = false;
 139
 140       while (1)
 141         {
 142           if (__libc_use_alloca (len * sizeof (wchar_t)))
 143             wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
 144           else
 145             {
 146               if (!use_malloc)
 147                 wmessage = NULL;
 148
 149               wchar_t *p = (wchar_t *) realloc (wmessage,
 150                                                 len * sizeof (wchar_t));
 151               if (p == NULL)
 152                 {
 153                   free (wmessage);
 154                   fputws_unlocked (L"out of memory\n", stderr);
 155                   return;
 156                 }
 157               wmessage = p;
 158               use_malloc = true;
 159             }
 160
 161           memset (&st, '\0', sizeof (st));
 162           tmp = message;
 163
 164           res = mbsrtowcs (wmessage, &tmp, len, &st);
 165           if (res != len)
 166             break;
 167
 168           if (__builtin_expect (len >= SIZE_MAX / 2, 0))
 169             {
 170               /* This really should not happen if everything is fine.  */
 171               res = (size_t) -1;
 172               break;
 173             }
 174
 175           len *= 2;
 176         }
 177
 178       if (res == (size_t) -1)
 179         {
 180           /* The string cannot be converted.  */
 181           if (use_malloc)
 182             {
 183               free (wmessage);
 184               use_malloc = false;
 185             }
 186           wmessage = (wchar_t *) L"???";
 187         }
 188
 189       __vfwprintf (stderr, wmessage, args);
 190
 191       if (use_malloc)
 192         free (wmessage);
 193     }
 194   else
 195 #endif
 196     vfprintf (stderr, message, args);
 197   va_end (args);
 198
 199   ++error_message_count;
 200   if (errnum)
 201     print_errno_message (errnum);
 202 #if _LIBC
 203   __fxprintf (NULL, "\n");
 204 #else
 205   putc ('\n', stderr);
 206 #endif
 207   fflush (stderr);
 208   if (status)
 209     exit (status);
 210 }
 211
 212
 213 /* Print the program name and error message MESSAGE, which is a printf-style
 214    format string with optional args.
 215    If ERRNUM is nonzero, print its corresponding system error message.
 216    Exit with status STATUS if it is nonzero.  */
 217 void
 218 error (int status, int errnum, const char *message, ...)
 219 {
 220   va_list args;
 221
 222 #if defined _LIBC && defined __libc_ptf_call
 223   /* We do not want this call to be cut short by a thread
 224      cancellation.  Therefore disable cancellation for now.  */
 225   int state = PTHREAD_CANCEL_ENABLE;
 226   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 227                    0);
 228 #endif
 229
 230   fflush (stdout);
 231 #ifdef _LIBC
 232   _IO_flockfile (stderr);
 233 #endif
 234   if (error_print_progname)
 235     (*error_print_progname) ();
 236   else
 237     {
 238 #if _LIBC
 239       __fxprintf (NULL, "%s: ", program_name);
 240 #else
 241       fprintf (stderr, "%s: ", program_name);
 242 #endif
 243     }
 244
 245   va_start (args, message);
 246   error_tail (status, errnum, message, args);
 247
 248 #ifdef _LIBC
 249   _IO_funlockfile (stderr);
 250 # ifdef __libc_ptf_call
 251   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 252 # endif
 253 #endif
 254 }
 255 \f
 256 /* Sometimes we want to have at most one error per line.  This
 257    variable controls whether this mode is selected or not.  */
 258 int error_one_per_line;
 259
 260 void
 261 error_at_line (int status, int errnum, const char *file_name,
 262                unsigned int line_number, const char *message, ...)
 263 {
 264   va_list args;
 265
 266   if (error_one_per_line)
 267     {
 268       static const char *old_file_name;
 269       static unsigned int old_line_number;
 270
 271       if (old_line_number == line_number
 272           && (file_name == old_file_name
 273               || (old_file_name != NULL
 274                   && file_name != NULL
 275                   && strcmp (old_file_name, file_name) == 0)))
 276         /* Simply return and print nothing.  */
 277         return;
 278
 279       old_file_name = file_name;
 280       old_line_number = line_number;
 281     }
 282
 283 #if defined _LIBC && defined __libc_ptf_call
 284   /* We do not want this call to be cut short by a thread
 285      cancellation.  Therefore disable cancellation for now.  */
 286   int state = PTHREAD_CANCEL_ENABLE;
 287   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 288                    0);
 289 #endif
 290
 291   fflush (stdout);
 292 #ifdef _LIBC
 293   _IO_flockfile (stderr);
 294 #endif
 295   if (error_print_progname)
 296     (*error_print_progname) ();
 297   else
 298     {
 299 #if _LIBC
 300       __fxprintf (NULL, "%s:", program_name);
 301 #else
 302       fprintf (stderr, "%s:", program_name);
 303 #endif
 304     }
 305
 306 #if _LIBC
 307   __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
 308               file_name, line_number);
 309 #else
 310   fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
 311            file_name, line_number);
 312 #endif
 313
 314   va_start (args, message);
 315   error_tail (status, errnum, message, args);
 316
 317 #ifdef _LIBC
 318   _IO_funlockfile (stderr);
 319 # ifdef __libc_ptf_call
 320   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 321 # endif
 322 #endif
 323 }
 324
 325 #ifdef _LIBC
 326 /* Make the weak alias.  */
 327 # undef error
 328 # undef error_at_line
 329 weak_alias (__error, error)
 330 weak_alias (__error_at_line, error_at_line)
 331 #endif