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 (at) 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 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 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 } 327 328 /* Sometimes we want to have at most one error per line. This 330 variable controls whether this mode is selected or not. */ 331 int error_one_per_line; 332 333 void 334 error_at_line (int status, int errnum, const char *file_name, 335 unsigned int line_number, const char *message, ...) 336 { 337 va_list args; 338 339 if (error_one_per_line) 340 { 341 static const char *old_file_name; 342 static unsigned int old_line_number; 343 344 if (old_line_number == line_number 345 && (file_name == old_file_name 346 || strcmp (old_file_name, file_name) == 0)) 347 /* Simply return and print nothing. */ 348 return; 349 350 old_file_name = file_name; 351 old_line_number = line_number; 352 } 353 354 #if defined _LIBC && defined __libc_ptf_call 355 /* We do not want this call to be cut short by a thread 356 cancellation. Therefore disable cancellation for now. */ 357 int state = PTHREAD_CANCEL_ENABLE; 358 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 359 0); 360 #endif 361 362 flush_stdout (); 363 #ifdef _LIBC 364 _IO_flockfile (stderr); 365 #endif 366 if (error_print_progname) 367 (*error_print_progname) (); 368 else 369 { 370 #if _LIBC 371 __fxprintf (NULL, "%s:", program_name); 372 #else 373 fprintf (stderr, "%s:", program_name); 374 #endif 375 } 376 377 #if _LIBC 378 __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ", 379 file_name, line_number); 380 #else 381 fprintf (stderr, file_name != NULL ? "%s:%d: " : " ", 382 file_name, line_number); 383 #endif 384 385 va_start (args, message); 386 error_tail (status, errnum, message, args); 387 388 #ifdef _LIBC 389 _IO_funlockfile (stderr); 390 # ifdef __libc_ptf_call 391 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 392 # endif 393 #endif 394 } 395 396 #ifdef _LIBC 397 /* Make the weak alias. */ 398 # undef error 399 # undef error_at_line 400 weak_alias (__error, error) 401 weak_alias (__error_at_line, error_at_line) 402 #endif 403
