gl/error.c

   1 /* Error handler for noninteractive utilities
   2    Copyright (C) 1990-1998, 2000-2007, 2009-2012 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@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 # include <fcntl.h>
  89 # include <unistd.h>
  90
  91 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  92 /* Get declarations of the native Windows API functions.  */
  93 #  define WIN32_LEAN_AND_MEAN
  94 #  include <windows.h>
  95 /* Get _get_osfhandle.  */
  96 #  include "msvc-nothrow.h"
  97 # endif
  98
  99 /* The gnulib override of fcntl is not needed in this file.  */
 100 # undef fcntl
 101
 102 # if !HAVE_DECL_STRERROR_R
 103 #  ifndef HAVE_DECL_STRERROR_R
 104 "this configure-time declaration test was not run"
 105 #  endif
 106 #  if STRERROR_R_CHAR_P
 107 char *strerror_r ();
 108 #  else
 109 int strerror_r ();
 110 #  endif
 111 # endif
 112
 113 /* The calling program should define program_name and set it to the
 114    name of the executing program.  */
 115 extern char *program_name;
 116
 117 # if HAVE_STRERROR_R || defined strerror_r
 118 #  define __strerror_r strerror_r
 119 # endif /* HAVE_STRERROR_R || defined strerror_r */
 120 #endif  /* not _LIBC */
 121
 122 #if !_LIBC
 123 /* Return non-zero if FD is open.  */
 124 static inline int
 125 is_open (int fd)
 126 {
 127 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 128   /* On native Windows: The initial state of unassigned standard file
 129      descriptors is that they are open but point to an INVALID_HANDLE_VALUE.
 130      There is no fcntl, and the gnulib replacement fcntl does not support
 131      F_GETFL.  */
 132   return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
 133 # else
 134 #  ifndef F_GETFL
 135 #   error Please port fcntl to your platform
 136 #  endif
 137   return 0 <= fcntl (fd, F_GETFL);
 138 # endif
 139 }
 140 #endif
 141
 142 static inline void
 143 flush_stdout (void)
 144 {
 145 #if !_LIBC
 146   int stdout_fd;
 147
 148 # if GNULIB_FREOPEN_SAFER
 149   /* Use of gnulib's freopen-safer module normally ensures that
 150        fileno (stdout) == 1
 151      whenever stdout is open.  */
 152   stdout_fd = STDOUT_FILENO;
 153 # else
 154   /* POSIX states that fileno (stdout) after fclose is unspecified.  But in
 155      practice it is not a problem, because stdout is statically allocated and
 156      the fd of a FILE stream is stored as a field in its allocated memory.  */
 157   stdout_fd = fileno (stdout);
 158 # endif
 159   /* POSIX states that fflush (stdout) after fclose is unspecified; it
 160      is safe in glibc, but not on all other platforms.  fflush (NULL)
 161      is always defined, but too draconian.  */
 162   if (0 <= stdout_fd && is_open (stdout_fd))
 163 #endif
 164     fflush (stdout);
 165 }
 166
 167 static void
 168 print_errno_message (int errnum)
 169 {
 170   char const *s;
 171
 172 #if defined HAVE_STRERROR_R || _LIBC
 173   char errbuf[1024];
 174 # if STRERROR_R_CHAR_P || _LIBC
 175   s = __strerror_r (errnum, errbuf, sizeof errbuf);
 176 # else
 177   if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
 178     s = errbuf;
 179   else
 180     s = 0;
 181 # endif
 182 #else
 183   s = strerror (errnum);
 184 #endif
 185
 186 #if !_LIBC
 187   if (! s)
 188     s = _("Unknown system error");
 189 #endif
 190
 191 #if _LIBC
 192   __fxprintf (NULL, ": %s", s);
 193 #else
 194   fprintf (stderr, ": %s", s);
 195 #endif
 196 }
 197
 198 static void
 199 error_tail (int status, int errnum, const char *message, va_list args)
 200 {
 201 #if _LIBC
 202   if (_IO_fwide (stderr, 0) > 0)
 203     {
 204 # define ALLOCA_LIMIT 2000
 205       size_t len = strlen (message) + 1;
 206       wchar_t *wmessage = NULL;
 207       mbstate_t st;
 208       size_t res;
 209       const char *tmp;
 210       bool use_malloc = false;
 211
 212       while (1)
 213         {
 214           if (__libc_use_alloca (len * sizeof (wchar_t)))
 215             wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
 216           else
 217             {
 218               if (!use_malloc)
 219                 wmessage = NULL;
 220
 221               wchar_t *p = (wchar_t *) realloc (wmessage,
 222                                                 len * sizeof (wchar_t));
 223               if (p == NULL)
 224                 {
 225                   free (wmessage);
 226                   fputws_unlocked (L"out of memory\n", stderr);
 227                   return;
 228                 }
 229               wmessage = p;
 230               use_malloc = true;
 231             }
 232
 233           memset (&st, '\0', sizeof (st));
 234           tmp = message;
 235
 236           res = mbsrtowcs (wmessage, &tmp, len, &st);
 237           if (res != len)
 238             break;
 239
 240           if (__builtin_expect (len >= SIZE_MAX / 2, 0))
 241             {
 242               /* This really should not happen if everything is fine.  */
 243               res = (size_t) -1;
 244               break;
 245             }
 246
 247           len *= 2;
 248         }
 249
 250       if (res == (size_t) -1)
 251         {
 252           /* The string cannot be converted.  */
 253           if (use_malloc)
 254             {
 255               free (wmessage);
 256               use_malloc = false;
 257             }
 258           wmessage = (wchar_t *) L"???";
 259         }
 260
 261       __vfwprintf (stderr, wmessage, args);
 262
 263       if (use_malloc)
 264         free (wmessage);
 265     }
 266   else
 267 #endif
 268     vfprintf (stderr, message, args);
 269   va_end (args);
 270
 271   ++error_message_count;
 272   if (errnum)
 273     print_errno_message (errnum);
 274 #if _LIBC
 275   __fxprintf (NULL, "\n");
 276 #else
 277   putc ('\n', stderr);
 278 #endif
 279   fflush (stderr);
 280   if (status)
 281     exit (status);
 282 }
 283
 284
 285 /* Print the program name and error message MESSAGE, which is a printf-style
 286    format string with optional args.
 287    If ERRNUM is nonzero, print its corresponding system error message.
 288    Exit with status STATUS if it is nonzero.  */
 289 void
 290 error (int status, int errnum, const char *message, ...)
 291 {
 292   va_list args;
 293
 294 #if defined _LIBC && defined __libc_ptf_call
 295   /* We do not want this call to be cut short by a thread
 296      cancellation.  Therefore disable cancellation for now.  */
 297   int state = PTHREAD_CANCEL_ENABLE;
 298   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 299                    0);
 300 #endif
 301
 302   flush_stdout ();
 303 #ifdef _LIBC
 304   _IO_flockfile (stderr);
 305 #endif
 306   if (error_print_progname)
 307     (*error_print_progname) ();
 308   else
 309     {
 310 #if _LIBC
 311       __fxprintf (NULL, "%s: ", program_name);
 312 #else
 313       fprintf (stderr, "%s: ", program_name);
 314 #endif
 315     }
 316
 317   va_start (args, message);
 318   error_tail (status, errnum, message, args);
 319
 320 #ifdef _LIBC
 321   _IO_funlockfile (stderr);
 322 # ifdef __libc_ptf_call
 323   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 324 # endif
 325 #endif
 326 }
 327 \f
 328 /* Sometimes we want to have at most one error per line.  This
 329    variable controls whether this mode is selected or not.  */
 330 int error_one_per_line;
 331
 332 void
 333 error_at_line (int status, int errnum, const char *file_name,
 334                unsigned int line_number, const char *message, ...)
 335 {
 336   va_list args;
 337
 338   if (error_one_per_line)
 339     {
 340       static const char *old_file_name;
 341       static unsigned int old_line_number;
 342
 343       if (old_line_number == line_number
 344           && (file_name == old_file_name
 345               || strcmp (old_file_name, file_name) == 0))
 346         /* Simply return and print nothing.  */
 347         return;
 348
 349       old_file_name = file_name;
 350       old_line_number = line_number;
 351     }
 352
 353 #if defined _LIBC && defined __libc_ptf_call
 354   /* We do not want this call to be cut short by a thread
 355      cancellation.  Therefore disable cancellation for now.  */
 356   int state = PTHREAD_CANCEL_ENABLE;
 357   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 358                    0);
 359 #endif
 360
 361   flush_stdout ();
 362 #ifdef _LIBC
 363   _IO_flockfile (stderr);
 364 #endif
 365   if (error_print_progname)
 366     (*error_print_progname) ();
 367   else
 368     {
 369 #if _LIBC
 370       __fxprintf (NULL, "%s:", program_name);
 371 #else
 372       fprintf (stderr, "%s:", program_name);
 373 #endif
 374     }
 375
 376 #if _LIBC
 377   __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ",
 378               file_name, line_number);
 379 #else
 380   fprintf (stderr, file_name != NULL ? "%s:%d: " : " ",
 381            file_name, line_number);
 382 #endif
 383
 384   va_start (args, message);
 385   error_tail (status, errnum, message, args);
 386
 387 #ifdef _LIBC
 388   _IO_funlockfile (stderr);
 389 # ifdef __libc_ptf_call
 390   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 391 # endif
 392 #endif
 393 }
 394
 395 #ifdef _LIBC
 396 /* Make the weak alias.  */
 397 # undef error
 398 # undef error_at_line
 399 weak_alias (__error, error)
 400 weak_alias (__error_at_line, error_at_line)
 401 #endif