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@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
is_open(int fd)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
flush_stdout(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
print_errno_message(int errnum)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
error_tail(int status,int errnum,const char * message,va_list args)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
error(int status,int errnum,const char * message,...)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
329 variable controls whether this mode is selected or not. */
330 int error_one_per_line;
331
332 void
error_at_line(int status,int errnum,const char * file_name,unsigned int line_number,const char * message,...)333 error_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
399 weak_alias (__error, error)
400 weak_alias (__error_at_line, error_at_line)
401 #endif
402