gnulib/import/error.c

   1 /* Error handler for noninteractive utilities
   2    Copyright (C) 1990-1998, 2000-2007, 2009-2016 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 # define USE_UNLOCKED_IO 0
  43 # define _GL_ATTRIBUTE_FORMAT_PRINTF(a, b)
  44 # define _GL_ARG_NONNULL(a)
  45 #else
  46 # include "getprogname.h"
  47 #endif
  48
  49 #if USE_UNLOCKED_IO
  50 # include "unlocked-io.h"
  51 #endif
  52
  53 #ifndef _
  54 # define _(String) String
  55 #endif
  56
  57 /* If NULL, error will flush stdout, then print on stderr the program
  58    name, a colon and a space.  Otherwise, error will call this
  59    function without parameters instead.  */
  60 void (*error_print_progname) (void);
  61
  62 /* This variable is incremented each time 'error' is called.  */
  63 unsigned int error_message_count;
  64
  65 #ifdef _LIBC
  66 /* In the GNU C library, there is a predefined variable for this.  */
  67
  68 # define program_name program_invocation_name
  69 # include <errno.h>
  70 # include <limits.h>
  71 # include <libio/libioP.h>
  72
  73 /* In GNU libc we want do not want to use the common name 'error' directly.
  74    Instead make it a weak alias.  */
  75 extern void __error (int status, int errnum, const char *message, ...)
  76      __attribute__ ((__format__ (__printf__, 3, 4)));
  77 extern void __error_at_line (int status, int errnum, const char *file_name,
  78                              unsigned int line_number, const char *message,
  79                              ...)
  80      __attribute__ ((__format__ (__printf__, 5, 6)));
  81 # define error __error
  82 # define error_at_line __error_at_line
  83
  84 # include <libio/iolibio.h>
  85 # define fflush(s) _IO_fflush (s)
  86 # undef putc
  87 # define putc(c, fp) _IO_putc (c, fp)
  88
  89 # include <bits/libc-lock.h>
  90
  91 #else /* not _LIBC */
  92
  93 # include <fcntl.h>
  94 # include <unistd.h>
  95
  96 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  97 /* Get declarations of the native Windows API functions.  */
  98 #  define WIN32_LEAN_AND_MEAN
  99 #  include <windows.h>
 100 /* Get _get_osfhandle.  */
 101 #  include "msvc-nothrow.h"
 102 # endif
 103
 104 /* The gnulib override of fcntl is not needed in this file.  */
 105 # undef fcntl
 106
 107 # if !HAVE_DECL_STRERROR_R
 108 #  ifndef HAVE_DECL_STRERROR_R
 109 "this configure-time declaration test was not run"
 110 #  endif
 111 #  if STRERROR_R_CHAR_P
 112 char *strerror_r ();
 113 #  else
 114 int strerror_r ();
 115 #  endif
 116 # endif
 117
 118 #define program_name getprogname ()
 119
 120 # if HAVE_STRERROR_R || defined strerror_r
 121 #  define __strerror_r strerror_r
 122 # endif /* HAVE_STRERROR_R || defined strerror_r */
 123 #endif  /* not _LIBC */
 124
 125 #if !_LIBC
 126 /* Return non-zero if FD is open.  */
 127 static int
 128 is_open (int fd)
 129 {
 130 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 131   /* On native Windows: The initial state of unassigned standard file
 132      descriptors is that they are open but point to an INVALID_HANDLE_VALUE.
 133      There is no fcntl, and the gnulib replacement fcntl does not support
 134      F_GETFL.  */
 135   return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
 136 # else
 137 #  ifndef F_GETFL
 138 #   error Please port fcntl to your platform
 139 #  endif
 140   return 0 <= fcntl (fd, F_GETFL);
 141 # endif
 142 }
 143 #endif
 144
 145 static void
 146 flush_stdout (void)
 147 {
 148 #if !_LIBC
 149   int stdout_fd;
 150
 151 # if GNULIB_FREOPEN_SAFER
 152   /* Use of gnulib's freopen-safer module normally ensures that
 153        fileno (stdout) == 1
 154      whenever stdout is open.  */
 155   stdout_fd = STDOUT_FILENO;
 156 # else
 157   /* POSIX states that fileno (stdout) after fclose is unspecified.  But in
 158      practice it is not a problem, because stdout is statically allocated and
 159      the fd of a FILE stream is stored as a field in its allocated memory.  */
 160   stdout_fd = fileno (stdout);
 161 # endif
 162   /* POSIX states that fflush (stdout) after fclose is unspecified; it
 163      is safe in glibc, but not on all other platforms.  fflush (NULL)
 164      is always defined, but too draconian.  */
 165   if (0 <= stdout_fd && is_open (stdout_fd))
 166 #endif
 167     fflush (stdout);
 168 }
 169
 170 static void
 171 print_errno_message (int errnum)
 172 {
 173   char const *s;
 174
 175 #if defined HAVE_STRERROR_R || _LIBC
 176   char errbuf[1024];
 177 # if _LIBC || STRERROR_R_CHAR_P
 178   s = __strerror_r (errnum, errbuf, sizeof errbuf);
 179 # else
 180   if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
 181     s = errbuf;
 182   else
 183     s = 0;
 184 # endif
 185 #else
 186   s = strerror (errnum);
 187 #endif
 188
 189 #if !_LIBC
 190   if (! s)
 191     s = _("Unknown system error");
 192 #endif
 193
 194 #if _LIBC
 195   __fxprintf (NULL, ": %s", s);
 196 #else
 197   fprintf (stderr, ": %s", s);
 198 #endif
 199 }
 200
 201 static void _GL_ATTRIBUTE_FORMAT_PRINTF (3, 0) _GL_ARG_NONNULL ((3))
 202 error_tail (int status, int errnum, const char *message, va_list args)
 203 {
 204 #if _LIBC
 205   if (_IO_fwide (stderr, 0) > 0)
 206     {
 207       size_t len = strlen (message) + 1;
 208       wchar_t *wmessage = NULL;
 209       mbstate_t st;
 210       size_t res;
 211       const char *tmp;
 212       bool use_malloc = false;
 213
 214       while (1)
 215         {
 216           if (__libc_use_alloca (len * sizeof (wchar_t)))
 217             wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
 218           else
 219             {
 220               if (!use_malloc)
 221                 wmessage = NULL;
 222
 223               wchar_t *p = (wchar_t *) realloc (wmessage,
 224                                                 len * sizeof (wchar_t));
 225               if (p == NULL)
 226                 {
 227                   free (wmessage);
 228                   fputws_unlocked (L"out of memory\n", stderr);
 229                   return;
 230                 }
 231               wmessage = p;
 232               use_malloc = true;
 233             }
 234
 235           memset (&st, '\0', sizeof (st));
 236           tmp = message;
 237
 238           res = mbsrtowcs (wmessage, &tmp, len, &st);
 239           if (res != len)
 240             break;
 241
 242           if (__builtin_expect (len >= SIZE_MAX / sizeof (wchar_t) / 2, 0))
 243             {
 244               /* This really should not happen if everything is fine.  */
 245               res = (size_t) -1;
 246               break;
 247             }
 248
 249           len *= 2;
 250         }
 251
 252       if (res == (size_t) -1)
 253         {
 254           /* The string cannot be converted.  */
 255           if (use_malloc)
 256             {
 257               free (wmessage);
 258               use_malloc = false;
 259             }
 260           wmessage = (wchar_t *) L"???";
 261         }
 262
 263       __vfwprintf (stderr, wmessage, args);
 264
 265       if (use_malloc)
 266         free (wmessage);
 267     }
 268   else
 269 #endif
 270     vfprintf (stderr, message, args);
 271   va_end (args);
 272
 273   ++error_message_count;
 274   if (errnum)
 275     print_errno_message (errnum);
 276 #if _LIBC
 277   __fxprintf (NULL, "\n");
 278 #else
 279   putc ('\n', stderr);
 280 #endif
 281   fflush (stderr);
 282   if (status)
 283     exit (status);
 284 }
 285
 286
 287 /* Print the program name and error message MESSAGE, which is a printf-style
 288    format string with optional args.
 289    If ERRNUM is nonzero, print its corresponding system error message.
 290    Exit with status STATUS if it is nonzero.  */
 291 void
 292 error (int status, int errnum, const char *message, ...)
 293 {
 294   va_list args;
 295
 296 #if defined _LIBC && defined __libc_ptf_call
 297   /* We do not want this call to be cut short by a thread
 298      cancellation.  Therefore disable cancellation for now.  */
 299   int state = PTHREAD_CANCEL_ENABLE;
 300   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 301                    0);
 302 #endif
 303
 304   flush_stdout ();
 305 #ifdef _LIBC
 306   _IO_flockfile (stderr);
 307 #endif
 308   if (error_print_progname)
 309     (*error_print_progname) ();
 310   else
 311     {
 312 #if _LIBC
 313       __fxprintf (NULL, "%s: ", program_name);
 314 #else
 315       fprintf (stderr, "%s: ", program_name);
 316 #endif
 317     }
 318
 319   va_start (args, message);
 320   error_tail (status, errnum, message, args);
 321
 322 #ifdef _LIBC
 323   _IO_funlockfile (stderr);
 324 # ifdef __libc_ptf_call
 325   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 326 # endif
 327 #endif
 328 }
 329 \f
 330 /* Sometimes we want to have at most one error per line.  This
 331    variable controls whether this mode is selected or not.  */
 332 int error_one_per_line;
 333
 334 void
 335 error_at_line (int status, int errnum, const char *file_name,
 336                unsigned int line_number, const char *message, ...)
 337 {
 338   va_list args;
 339
 340   if (error_one_per_line)
 341     {
 342       static const char *old_file_name;
 343       static unsigned int old_line_number;
 344
 345       if (old_line_number == line_number
 346           && (file_name == old_file_name
 347               || (old_file_name != NULL
 348                   && file_name != NULL
 349                   && strcmp (old_file_name, file_name) == 0)))
 350
 351         /* Simply return and print nothing.  */
 352         return;
 353
 354       old_file_name = file_name;
 355       old_line_number = line_number;
 356     }
 357
 358 #if defined _LIBC && defined __libc_ptf_call
 359   /* We do not want this call to be cut short by a thread
 360      cancellation.  Therefore disable cancellation for now.  */
 361   int state = PTHREAD_CANCEL_ENABLE;
 362   __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
 363                    0);
 364 #endif
 365
 366   flush_stdout ();
 367 #ifdef _LIBC
 368   _IO_flockfile (stderr);
 369 #endif
 370   if (error_print_progname)
 371     (*error_print_progname) ();
 372   else
 373     {
 374 #if _LIBC
 375       __fxprintf (NULL, "%s:", program_name);
 376 #else
 377       fprintf (stderr, "%s:", program_name);
 378 #endif
 379     }
 380
 381 #if _LIBC
 382   __fxprintf (NULL, file_name != NULL ? "%s:%u: " : " ",
 383               file_name, line_number);
 384 #else
 385   fprintf (stderr, file_name != NULL ? "%s:%u: " : " ",
 386            file_name, line_number);
 387 #endif
 388
 389   va_start (args, message);
 390   error_tail (status, errnum, message, args);
 391
 392 #ifdef _LIBC
 393   _IO_funlockfile (stderr);
 394 # ifdef __libc_ptf_call
 395   __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
 396 # endif
 397 #endif
 398 }
 399
 400 #ifdef _LIBC
 401 /* Make the weak alias.  */
 402 # undef error
 403 # undef error_at_line
 404 weak_alias (__error, error)
 405 weak_alias (__error_at_line, error_at_line)
 406 #endif