1/* Error handler for noninteractive utilities 2 Copyright (C) 1990-1998, 2000-2007, 2009-2014 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. */ 55void (*error_print_progname) (void); 56 57/* This variable is incremented each time 'error' is called. */ 58unsigned 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. */ 70extern void __error (int status, int errnum, const char *message, ...) 71 __attribute__ ((__format__ (__printf__, 3, 4))); 72extern 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 107char *strerror_r (); 108# else 109int 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. */ 115extern 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. */ 124static int 125is_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 142static void 143flush_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 167static void 168print_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 198static void _GL_ATTRIBUTE_FORMAT_PRINTF (3, 0) _GL_ARG_NONNULL ((3)) 199error_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. */ 289void 290error (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 329 variable controls whether this mode is selected or not. */ 330int error_one_per_line; 331 332void 333error_at_line (int status, int errnum, const char *file_name, 334 unsigned int line_number, const char *message, ...) 335{ 336 va_list args; 337 338 if (error_one_per_line) 339 { 340 static const char *old_file_name; 341 static unsigned int old_line_number; 342 343 if (old_line_number == line_number 344 && (file_name == old_file_name 345 || strcmp (old_file_name, file_name) == 0)) 346 /* Simply return and print nothing. */ 347 return; 348 349 old_file_name = file_name; 350 old_line_number = line_number; 351 } 352 353#if defined _LIBC && defined __libc_ptf_call 354 /* We do not want this call to be cut short by a thread 355 cancellation. Therefore disable cancellation for now. */ 356 int state = PTHREAD_CANCEL_ENABLE; 357 __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state), 358 0); 359#endif 360 361 flush_stdout (); 362#ifdef _LIBC 363 _IO_flockfile (stderr); 364#endif 365 if (error_print_progname) 366 (*error_print_progname) (); 367 else 368 { 369#if _LIBC 370 __fxprintf (NULL, "%s:", program_name); 371#else 372 fprintf (stderr, "%s:", program_name); 373#endif 374 } 375 376#if _LIBC 377 __fxprintf (NULL, file_name != NULL ? "%s:%d: " : " ", 378 file_name, line_number); 379#else 380 fprintf (stderr, file_name != NULL ? "%s:%d: " : " ", 381 file_name, line_number); 382#endif 383 384 va_start (args, message); 385 error_tail (status, errnum, message, args); 386 387#ifdef _LIBC 388 _IO_funlockfile (stderr); 389# ifdef __libc_ptf_call 390 __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0); 391# endif 392#endif 393} 394 395#ifdef _LIBC 396/* Make the weak alias. */ 397# undef error 398# undef error_at_line 399weak_alias (__error, error) 400weak_alias (__error_at_line, error_at_line) 401#endif 402