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 !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P 92 # ifndef HAVE_DECL_STRERROR_R 93 "this configure-time declaration test was not run" 94 # endif 95 char *strerror_r (); 96 # endif 97 98 /* The calling program should define program_name and set it to the 99 name of the executing program. */ 100 extern char *program_name; 101 102 # if HAVE_STRERROR_R || defined strerror_r 103 # define __strerror_r strerror_r 104 # endif /* HAVE_STRERROR_R || defined strerror_r */ 105 #endif /* not _LIBC */ 106 107 static inline void 108 flush_stdout (void) 109 { 110 #if !_LIBC && defined F_GETFL 111 int stdout_fd; 112 113 # if GNULIB_FREOPEN_SAFER 114 /* Use of gnulib's freopen-safer module normally ensures that 115 fileno (stdout) == 1 116 whenever stdout is open. */ 117 stdout_fd = STDOUT_FILENO; 118 # else 119 /* POSIX states that fileno (stdout) after fclose is unspecified. But in 120 practice it is not a problem, because stdout is statically allocated and 121 the fd of a FILE stream is stored as a field in its allocated memory. */ 122 stdout_fd = fileno (stdout); 123 # endif 124 /* POSIX states that fflush (stdout) after fclose is unspecified; it 125 is safe in glibc, but not on all other platforms. fflush (NULL) 126 is always defined, but too draconian. */ 127 if (0 <= stdout_fd && 0 <= fcntl (stdout_fd, F_GETFL)) 128 #endif 129 fflush (stdout); 130 } 131 132 static void 133 print_errno_message (int errnum) 134 { 135 char const *s; 136 137 #if defined HAVE_STRERROR_R || _LIBC 138 char errbuf[1024]; 139 # if STRERROR_R_CHAR_P || _LIBC 140 s = __strerror_r (errnum, errbuf, sizeof errbuf); 141 # else 142 if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0) 143 s = errbuf; 144 else 145 s = 0; 146 # endif 147 #else 148 s = strerror (errnum); 149 #endif 150 151 #if !_LIBC 152 if (! s) 153 s = _("Unknown system error"); 154 #endif 155 156 #if _LIBC 157 __fxprintf (NULL, ": %s", s); 158 #else 159 fprintf (stderr, ": %s", s); 160 #endif 161 } 162 163 static void 164 error_tail (int status, int errnum, const char *message, va_list args) 165 { 166 #if _LIBC 167 if (_IO_fwide (stderr, 0) > 0) 168 { 169 # define ALLOCA_LIMIT 2000 170 size_t len = strlen (message) + 1; 171 wchar_t *wmessage = NULL; 172 mbstate_t st; 173 size_t res; 174 const char *tmp; 175 bool use_malloc = false; 176 177 while (1) 178 { 179 if (__libc_use_alloca (len * sizeof (wchar_t))) 180 wmessage = (wchar_t *) alloca (len * sizeof (wchar_t)); 181 else 182 { 183 if (!use_malloc) 184 wmessage = NULL; 185 186 wchar_t *p = (wchar_t *) realloc (wmessage, 187 len * sizeof (wchar_t)); 188 if (p == NULL) 189 { 190 free (wmessage); 191 fputws_unlocked (L"out of memory\n", stderr); 192 return; 193 } 194 wmessage = p; 195 use_malloc = true; 196 } 197 198 memset (&st, '\0', sizeof (st)); 199 tmp = message; 200 201 res = mbsrtowcs (wmessage, &tmp, len, &st); 202 if (res != len) 203 break; 204 205 if (__builtin_expect (len >= SIZE_MAX / 2, 0)) 206 { 207 /* This really should not happen if everything is fine. */ 208 res = (size_t) -1; 209 break; 210 } 211 212 len *= 2; 213 } 214 215 if (res == (size_t) -1) 216 { 217 /* The string cannot be converted. */ 218 if (use_malloc) 219 { 220 free (wmessage); 221 use_malloc = false; 222 } 223 wmessage = (wchar_t *) L"???"; 224 } 225 226 __vfwprintf (stderr, wmessage, args); 227 228 if (use_malloc) 229 free (wmessage); 230 } 231 else 232 #endif 233 vfprintf (stderr, message, args); 234 va_end (args); 235 236 ++error_message_count; 237 if (errnum) 238 print_errno_message (errnum); 239 #if _LIBC 240 __fxprintf (NULL, "\n"); 241 #else 242 putc ('\n', stderr); 243 #endif 244 fflush (stderr); 245 if (status) 246 exit (status); 247 } 248 249 250 /* Print the program name and error message MESSAGE, which is a printf-style 251 format string with optional args. 252 If ERRNUM is nonzero, print its corresponding system error message. 253 Exit with status STATUS if it is nonzero. */ 254 void 255 error (int status, int errnum, const char *message, ...) 256 { 257 va_list args; 258 259 #if defined _LIBC && defined __libc_ptf_call 260 /* We do not want this call to be cut short by a thread 261 cancellation. Therefore disable cancellation for now. */ 262 int state = PTHREAD_CANCEL_ENABLE; 263 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 264 0); 265 #endif 266 267 flush_stdout (); 268 #ifdef _LIBC 269 _IO_flockfile (stderr); 270 #endif 271 if (error_print_progname) 272 (*error_print_progname) (); 273 else 274 { 275 #if _LIBC 276 __fxprintf (NULL, "%s: ", program_name); 277 #else 278 fprintf (stderr, "%s: ", program_name); 279 #endif 280 } 281 282 va_start (args, message); 283 error_tail (status, errnum, message, args); 284 285 #ifdef _LIBC 286 _IO_funlockfile (stderr); 287 # ifdef __libc_ptf_call 288 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 289 # endif 290 #endif 291 } 292 293 /* Sometimes we want to have at most one error per line. This 294 variable controls whether this mode is selected or not. */ 295 int error_one_per_line; 296 297 void 298 error_at_line (int status, int errnum, const char *file_name, 299 unsigned int line_number, const char *message, ...) 300 { 301 va_list args; 302 303 if (error_one_per_line) 304 { 305 static const char *old_file_name; 306 static unsigned int old_line_number; 307 308 if (old_line_number == line_number 309 && (file_name == old_file_name 310 || strcmp (old_file_name, file_name) == 0)) 311 /* Simply return and print nothing. */ 312 return; 313 314 old_file_name = file_name; 315 old_line_number = line_number; 316 } 317 318 #if defined _LIBC && defined __libc_ptf_call 319 /* We do not want this call to be cut short by a thread 320 cancellation. Therefore disable cancellation for now. */ 321 int state = PTHREAD_CANCEL_ENABLE; 322 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 323 0); 324 #endif 325 326 flush_stdout (); 327 #ifdef _LIBC 328 _IO_flockfile (stderr); 329 #endif 330 if (error_print_progname) 331 (*error_print_progname) (); 332 else 333 { 334 #if _LIBC 335 __fxprintf (NULL, "%s:", program_name); 336 #else 337 fprintf (stderr, "%s:", program_name); 338 #endif 339 } 340 341 #if _LIBC 342 __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ", 343 file_name, line_number); 344 #else 345 fprintf (stderr, file_name != NULL ? "%s:%d: " : " ", 346 file_name, line_number); 347 #endif 348 349 va_start (args, message); 350 error_tail (status, errnum, message, args); 351 352 #ifdef _LIBC 353 _IO_funlockfile (stderr); 354 # ifdef __libc_ptf_call 355 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 356 # endif 357 #endif 358 } 359 360 #ifdef _LIBC 361 /* Make the weak alias. */ 362 # undef error 363 # undef error_at_line 364 weak_alias (__error, error) 365 weak_alias (__error_at_line, error_at_line) 366 #endif 367