1 /* Error handler for noninteractive utilities 2 Copyright (C) 1990-1998, 2000-2007, 2009-2010 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 Win32 API functions. */ 93 # define WIN32_LEAN_AND_MEAN 94 # include <windows.h> 95 # endif 96 97 /* The gnulib override of fcntl is not needed in this file. */ 98 # undef fcntl 99 100 # if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P 101 # ifndef HAVE_DECL_STRERROR_R 102 "this configure-time declaration test was not run" 103 # endif 104 char *strerror_r (); 105 # endif 106 107 /* The calling program should define program_name and set it to the 108 name of the executing program. */ 109 extern char *program_name; 110 111 # if HAVE_STRERROR_R || defined strerror_r 112 # define __strerror_r strerror_r 113 # endif /* HAVE_STRERROR_R || defined strerror_r */ 114 #endif /* not _LIBC */ 115 116 #if !_LIBC 117 /* Return non-zero if FD is open. */ 118 static inline int 119 is_open (int fd) 120 { 121 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ 122 /* On Win32: The initial state of unassigned standard file descriptors is 123 that they are open but point to an INVALID_HANDLE_VALUE. There is no 124 fcntl, and the gnulib replacement fcntl does not support F_GETFL. */ 125 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE; 126 # else 127 # ifndef F_GETFL 128 # error Please port fcntl to your platform 129 # endif 130 return 0 <= fcntl (fd, F_GETFL); 131 # endif 132 } 133 #endif 134 135 static inline void 136 flush_stdout (void) 137 { 138 #if !_LIBC 139 int stdout_fd; 140 141 # if GNULIB_FREOPEN_SAFER 142 /* Use of gnulib's freopen-safer module normally ensures that 143 fileno (stdout) == 1 144 whenever stdout is open. */ 145 stdout_fd = STDOUT_FILENO; 146 # else 147 /* POSIX states that fileno (stdout) after fclose is unspecified. But in 148 practice it is not a problem, because stdout is statically allocated and 149 the fd of a FILE stream is stored as a field in its allocated memory. */ 150 stdout_fd = fileno (stdout); 151 # endif 152 /* POSIX states that fflush (stdout) after fclose is unspecified; it 153 is safe in glibc, but not on all other platforms. fflush (NULL) 154 is always defined, but too draconian. */ 155 if (0 <= stdout_fd && is_open (stdout_fd)) 156 #endif 157 fflush (stdout); 158 } 159 160 static void 161 print_errno_message (int errnum) 162 { 163 char const *s; 164 165 #if defined HAVE_STRERROR_R || _LIBC 166 char errbuf[1024]; 167 # if STRERROR_R_CHAR_P || _LIBC 168 s = __strerror_r (errnum, errbuf, sizeof errbuf); 169 # else 170 if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0) 171 s = errbuf; 172 else 173 s = 0; 174 # endif 175 #else 176 s = strerror (errnum); 177 #endif 178 179 #if !_LIBC 180 if (! s) 181 s = _("Unknown system error"); 182 #endif 183 184 #if _LIBC 185 __fxprintf (NULL, ": %s", s); 186 #else 187 fprintf (stderr, ": %s", s); 188 #endif 189 } 190 191 static void 192 error_tail (int status, int errnum, const char *message, va_list args) 193 { 194 #if _LIBC 195 if (_IO_fwide (stderr, 0) > 0) 196 { 197 # define ALLOCA_LIMIT 2000 198 size_t len = strlen (message) + 1; 199 wchar_t *wmessage = NULL; 200 mbstate_t st; 201 size_t res; 202 const char *tmp; 203 bool use_malloc = false; 204 205 while (1) 206 { 207 if (__libc_use_alloca (len * sizeof (wchar_t))) 208 wmessage = (wchar_t *) alloca (len * sizeof (wchar_t)); 209 else 210 { 211 if (!use_malloc) 212 wmessage = NULL; 213 214 wchar_t *p = (wchar_t *) realloc (wmessage, 215 len * sizeof (wchar_t)); 216 if (p == NULL) 217 { 218 free (wmessage); 219 fputws_unlocked (L"out of memory\n", stderr); 220 return; 221 } 222 wmessage = p; 223 use_malloc = true; 224 } 225 226 memset (&st, '\0', sizeof (st)); 227 tmp = message; 228 229 res = mbsrtowcs (wmessage, &tmp, len, &st); 230 if (res != len) 231 break; 232 233 if (__builtin_expect (len >= SIZE_MAX / 2, 0)) 234 { 235 /* This really should not happen if everything is fine. */ 236 res = (size_t) -1; 237 break; 238 } 239 240 len *= 2; 241 } 242 243 if (res == (size_t) -1) 244 { 245 /* The string cannot be converted. */ 246 if (use_malloc) 247 { 248 free (wmessage); 249 use_malloc = false; 250 } 251 wmessage = (wchar_t *) L"???"; 252 } 253 254 __vfwprintf (stderr, wmessage, args); 255 256 if (use_malloc) 257 free (wmessage); 258 } 259 else 260 #endif 261 vfprintf (stderr, message, args); 262 va_end (args); 263 264 ++error_message_count; 265 if (errnum) 266 print_errno_message (errnum); 267 #if _LIBC 268 __fxprintf (NULL, "\n"); 269 #else 270 putc ('\n', stderr); 271 #endif 272 fflush (stderr); 273 if (status) 274 exit (status); 275 } 276 277 278 /* Print the program name and error message MESSAGE, which is a printf-style 279 format string with optional args. 280 If ERRNUM is nonzero, print its corresponding system error message. 281 Exit with status STATUS if it is nonzero. */ 282 void 283 error (int status, int errnum, const char *message, ...) 284 { 285 va_list args; 286 287 #if defined _LIBC && defined __libc_ptf_call 288 /* We do not want this call to be cut short by a thread 289 cancellation. Therefore disable cancellation for now. */ 290 int state = PTHREAD_CANCEL_ENABLE; 291 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 292 0); 293 #endif 294 295 flush_stdout (); 296 #ifdef _LIBC 297 _IO_flockfile (stderr); 298 #endif 299 if (error_print_progname) 300 (*error_print_progname) (); 301 else 302 { 303 #if _LIBC 304 __fxprintf (NULL, "%s: ", program_name); 305 #else 306 fprintf (stderr, "%s: ", program_name); 307 #endif 308 } 309 310 va_start (args, message); 311 error_tail (status, errnum, message, args); 312 313 #ifdef _LIBC 314 _IO_funlockfile (stderr); 315 # ifdef __libc_ptf_call 316 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 317 # endif 318 #endif 319 } 320 321 /* Sometimes we want to have at most one error per line. This 322 variable controls whether this mode is selected or not. */ 323 int error_one_per_line; 324 325 void 326 error_at_line (int status, int errnum, const char *file_name, 327 unsigned int line_number, const char *message, ...) 328 { 329 va_list args; 330 331 if (error_one_per_line) 332 { 333 static const char *old_file_name; 334 static unsigned int old_line_number; 335 336 if (old_line_number == line_number 337 && (file_name == old_file_name 338 || strcmp (old_file_name, file_name) == 0)) 339 /* Simply return and print nothing. */ 340 return; 341 342 old_file_name = file_name; 343 old_line_number = line_number; 344 } 345 346 #if defined _LIBC && defined __libc_ptf_call 347 /* We do not want this call to be cut short by a thread 348 cancellation. Therefore disable cancellation for now. */ 349 int state = PTHREAD_CANCEL_ENABLE; 350 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 351 0); 352 #endif 353 354 flush_stdout (); 355 #ifdef _LIBC 356 _IO_flockfile (stderr); 357 #endif 358 if (error_print_progname) 359 (*error_print_progname) (); 360 else 361 { 362 #if _LIBC 363 __fxprintf (NULL, "%s:", program_name); 364 #else 365 fprintf (stderr, "%s:", program_name); 366 #endif 367 } 368 369 #if _LIBC 370 __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ", 371 file_name, line_number); 372 #else 373 fprintf (stderr, file_name != NULL ? "%s:%d: " : " ", 374 file_name, line_number); 375 #endif 376 377 va_start (args, message); 378 error_tail (status, errnum, message, args); 379 380 #ifdef _LIBC 381 _IO_funlockfile (stderr); 382 # ifdef __libc_ptf_call 383 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 384 # endif 385 #endif 386 } 387 388 #ifdef _LIBC 389 /* Make the weak alias. */ 390 # undef error 391 # undef error_at_line 392 weak_alias (__error, error) 393 weak_alias (__error_at_line, error_at_line) 394 #endif 395