1 /* Error handler for noninteractive utilities 2 Copyright (C) 1990-1998, 2000-2007, 2009-2018 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 <https://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 __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 # if GNULIB_MSVC_NOTHROW 102 # include "msvc-nothrow.h" 103 # else 104 # include <io.h> 105 # endif 106 # endif 107 108 /* The gnulib override of fcntl is not needed in this file. */ 109 # undef fcntl 110 111 # if !(GNULIB_STRERROR_R_POSIX || HAVE_DECL_STRERROR_R) 112 # ifndef HAVE_DECL_STRERROR_R 113 "this configure-time declaration test was not run" 114 # endif 115 # if STRERROR_R_CHAR_P 116 char *strerror_r (int errnum, char *buf, size_t buflen); 117 # else 118 int strerror_r (int errnum, char *buf, size_t buflen); 119 # endif 120 # endif 121 122 #define program_name getprogname () 123 124 # if GNULIB_STRERROR_R_POSIX || HAVE_STRERROR_R || defined strerror_r 125 # define __strerror_r strerror_r 126 # endif /* GNULIB_STRERROR_R_POSIX || HAVE_STRERROR_R || defined strerror_r */ 127 #endif /* not _LIBC */ 128 129 #if !_LIBC 130 /* Return non-zero if FD is open. */ 131 static int 132 is_open (int fd) 133 { 134 # if defined _WIN32 && ! defined __CYGWIN__ 135 /* On native Windows: The initial state of unassigned standard file 136 descriptors is that they are open but point to an INVALID_HANDLE_VALUE. 137 There is no fcntl, and the gnulib replacement fcntl does not support 138 F_GETFL. */ 139 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE; 140 # else 141 # ifndef F_GETFL 142 # error Please port fcntl to your platform 143 # endif 144 return 0 <= fcntl (fd, F_GETFL); 145 # endif 146 } 147 #endif 148 149 static void 150 flush_stdout (void) 151 { 152 #if !_LIBC 153 int stdout_fd; 154 155 # if GNULIB_FREOPEN_SAFER 156 /* Use of gnulib's freopen-safer module normally ensures that 157 fileno (stdout) == 1 158 whenever stdout is open. */ 159 stdout_fd = STDOUT_FILENO; 160 # else 161 /* POSIX states that fileno (stdout) after fclose is unspecified. But in 162 practice it is not a problem, because stdout is statically allocated and 163 the fd of a FILE stream is stored as a field in its allocated memory. */ 164 stdout_fd = fileno (stdout); 165 # endif 166 /* POSIX states that fflush (stdout) after fclose is unspecified; it 167 is safe in glibc, but not on all other platforms. fflush (NULL) 168 is always defined, but too draconian. */ 169 if (0 <= stdout_fd && is_open (stdout_fd)) 170 #endif 171 fflush (stdout); 172 } 173 174 static void 175 print_errno_message (int errnum) 176 { 177 char const *s; 178 179 #if _LIBC || GNULIB_STRERROR_R_POSIX || defined HAVE_STRERROR_R 180 char errbuf[1024]; 181 # if _LIBC || (!GNULIB_STRERROR_R_POSIX && STRERROR_R_CHAR_P) 182 s = __strerror_r (errnum, errbuf, sizeof errbuf); 183 # else 184 if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0) 185 s = errbuf; 186 else 187 s = 0; 188 # endif 189 #else 190 s = strerror (errnum); 191 #endif 192 193 #if !_LIBC 194 if (! s) 195 s = _("Unknown system error"); 196 #endif 197 198 #if _LIBC 199 __fxprintf (NULL, ": %s", s); 200 #else 201 fprintf (stderr, ": %s", s); 202 #endif 203 } 204 205 static void 206 error_tail (int status, int errnum, const char *message, va_list args) 207 { 208 #if _LIBC 209 if (_IO_fwide (stderr, 0) > 0) 210 { 211 size_t len = strlen (message) + 1; 212 wchar_t *wmessage = NULL; 213 mbstate_t st; 214 size_t res; 215 const char *tmp; 216 bool use_malloc = false; 217 218 while (1) 219 { 220 if (__libc_use_alloca (len * sizeof (wchar_t))) 221 wmessage = (wchar_t *) alloca (len * sizeof (wchar_t)); 222 else 223 { 224 if (!use_malloc) 225 wmessage = NULL; 226 227 wchar_t *p = (wchar_t *) realloc (wmessage, 228 len * sizeof (wchar_t)); 229 if (p == NULL) 230 { 231 free (wmessage); 232 fputws_unlocked (L"out of memory\n", stderr); 233 return; 234 } 235 wmessage = p; 236 use_malloc = true; 237 } 238 239 memset (&st, '\0', sizeof (st)); 240 tmp = message; 241 242 res = mbsrtowcs (wmessage, &tmp, len, &st); 243 if (res != len) 244 break; 245 246 if (__builtin_expect (len >= SIZE_MAX / sizeof (wchar_t) / 2, 0)) 247 { 248 /* This really should not happen if everything is fine. */ 249 res = (size_t) -1; 250 break; 251 } 252 253 len *= 2; 254 } 255 256 if (res == (size_t) -1) 257 { 258 /* The string cannot be converted. */ 259 if (use_malloc) 260 { 261 free (wmessage); 262 use_malloc = false; 263 } 264 wmessage = (wchar_t *) L"???"; 265 } 266 267 __vfwprintf (stderr, wmessage, args); 268 269 if (use_malloc) 270 free (wmessage); 271 } 272 else 273 #endif 274 vfprintf (stderr, message, args); 275 276 ++error_message_count; 277 if (errnum) 278 print_errno_message (errnum); 279 #if _LIBC 280 __fxprintf (NULL, "\n"); 281 #else 282 putc ('\n', stderr); 283 #endif 284 fflush (stderr); 285 if (status) 286 exit (status); 287 } 288 289 290 /* Print the program name and error message MESSAGE, which is a printf-style 291 format string with optional args. 292 If ERRNUM is nonzero, print its corresponding system error message. 293 Exit with status STATUS if it is nonzero. */ 294 void 295 error (int status, int errnum, const char *message, ...) 296 { 297 va_list args; 298 299 #if defined _LIBC && defined __libc_ptf_call 300 /* We do not want this call to be cut short by a thread 301 cancellation. Therefore disable cancellation for now. */ 302 int state = PTHREAD_CANCEL_ENABLE; 303 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 304 0); 305 #endif 306 307 flush_stdout (); 308 #ifdef _LIBC 309 _IO_flockfile (stderr); 310 #endif 311 if (error_print_progname) 312 (*error_print_progname) (); 313 else 314 { 315 #if _LIBC 316 __fxprintf (NULL, "%s: ", program_name); 317 #else 318 fprintf (stderr, "%s: ", program_name); 319 #endif 320 } 321 322 va_start (args, message); 323 error_tail (status, errnum, message, args); 324 va_end (args); 325 326 #ifdef _LIBC 327 _IO_funlockfile (stderr); 328 # ifdef __libc_ptf_call 329 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 330 # endif 331 #endif 332 } 333 334 /* Sometimes we want to have at most one error per line. This 335 variable controls whether this mode is selected or not. */ 336 int error_one_per_line; 337 338 void 339 error_at_line (int status, int errnum, const char *file_name, 340 unsigned int line_number, const char *message, ...) 341 { 342 va_list args; 343 344 if (error_one_per_line) 345 { 346 static const char *old_file_name; 347 static unsigned int old_line_number; 348 349 if (old_line_number == line_number 350 && (file_name == old_file_name 351 || (old_file_name != NULL 352 && file_name != NULL 353 && strcmp (old_file_name, file_name) == 0))) 354 355 /* Simply return and print nothing. */ 356 return; 357 358 old_file_name = file_name; 359 old_line_number = line_number; 360 } 361 362 #if defined _LIBC && defined __libc_ptf_call 363 /* We do not want this call to be cut short by a thread 364 cancellation. Therefore disable cancellation for now. */ 365 int state = PTHREAD_CANCEL_ENABLE; 366 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 367 0); 368 #endif 369 370 flush_stdout (); 371 #ifdef _LIBC 372 _IO_flockfile (stderr); 373 #endif 374 if (error_print_progname) 375 (*error_print_progname) (); 376 else 377 { 378 #if _LIBC 379 __fxprintf (NULL, "%s:", program_name); 380 #else 381 fprintf (stderr, "%s:", program_name); 382 #endif 383 } 384 385 #if _LIBC 386 __fxprintf (NULL, file_name != NULL ? "%s:%u: " : " ", 387 file_name, line_number); 388 #else 389 fprintf (stderr, file_name != NULL ? "%s:%u: " : " ", 390 file_name, line_number); 391 #endif 392 393 va_start (args, message); 394 error_tail (status, errnum, message, args); 395 va_end (args); 396 397 #ifdef _LIBC 398 _IO_funlockfile (stderr); 399 # ifdef __libc_ptf_call 400 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 401 # endif 402 #endif 403 } 404 405 #ifdef _LIBC 406 /* Make the weak alias. */ 407 # undef error 408 # undef error_at_line 409 weak_alias (__error, error) 410 weak_alias (__error_at_line, error_at_line) 411 #endif 412