1 /* Error handler for noninteractive utilities
2 Copyright (C) 1990-1998, 2000-2007, 2009-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file 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 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser 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_STANDARD(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 _GL_ATTRIBUTE_FORMAT_PRINTF_STANDARD (3, 0) _GL_ARG_NONNULL ((3))
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