1 /* Error handler for noninteractive utilities 2 Copyright (C) 1990-1998, 2000-2007, 2009-2015 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 #endif 46 47 #if USE_UNLOCKED_IO 48 # include "unlocked-io.h" 49 #endif 50 51 #ifndef _ 52 # define _(String) String 53 #endif 54 55 /* If NULL, error will flush stdout, then print on stderr the program 56 name, a colon and a space. Otherwise, error will call this 57 function without parameters instead. */ 58 void (*error_print_progname) (void); 59 60 /* This variable is incremented each time 'error' is called. */ 61 unsigned int error_message_count; 62 63 #ifdef _LIBC 64 /* In the GNU C library, there is a predefined variable for this. */ 65 66 # define program_name program_invocation_name 67 # include <errno.h> 68 # include <limits.h> 69 # include <libio/libioP.h> 70 71 /* In GNU libc we want do not want to use the common name 'error' directly. 72 Instead make it a weak alias. */ 73 extern void __error (int status, int errnum, const char *message, ...) 74 __attribute__ ((__format__ (__printf__, 3, 4))); 75 extern void __error_at_line (int status, int errnum, const char *file_name, 76 unsigned int line_number, const char *message, 77 ...) 78 __attribute__ ((__format__ (__printf__, 5, 6))); 79 # define error __error 80 # define error_at_line __error_at_line 81 82 # include <libio/iolibio.h> 83 # define fflush(s) _IO_fflush (s) 84 # undef putc 85 # define putc(c, fp) _IO_putc (c, fp) 86 87 # include <bits/libc-lock.h> 88 89 #else /* not _LIBC */ 90 91 # include <fcntl.h> 92 # include <unistd.h> 93 94 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ 95 /* Get declarations of the native Windows API functions. */ 96 # define WIN32_LEAN_AND_MEAN 97 # include <windows.h> 98 /* Get _get_osfhandle. */ 99 # include "msvc-nothrow.h" 100 # endif 101 102 /* The gnulib override of fcntl is not needed in this file. */ 103 # undef fcntl 104 105 # if !HAVE_DECL_STRERROR_R 106 # ifndef HAVE_DECL_STRERROR_R 107 "this configure-time declaration test was not run" 108 # endif 109 # if STRERROR_R_CHAR_P 110 char *strerror_r (); 111 # else 112 int strerror_r (); 113 # endif 114 # endif 115 116 /* The calling program should define program_name and set it to the 117 name of the executing program. */ 118 extern char *program_name; 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 } 329 330 /* 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 407