1/* Error handler for noninteractive utilities
2   Copyright (C) 1990-1998, 2000-2003, 2004 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 2, or (at your option)
8   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 along
16   with this program; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
18
19/* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
20
21#ifdef HAVE_CONFIG_H
22# include <config.h>
23#endif
24
25#include "error.h"
26
27#include <stdarg.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31
32#if !_LIBC && ENABLE_NLS
33# include "gettext.h"
34#endif
35
36#ifdef _LIBC
37# include <wchar.h>
38# define mbsrtowcs __mbsrtowcs
39#endif
40
41#if USE_UNLOCKED_IO
42# include "unlocked-io.h"
43#endif
44
45#ifndef _
46# define _(String) String
47#endif
48
49/* If NULL, error will flush stdout, then print on stderr the program
50   name, a colon and a space.  Otherwise, error will call this
51   function without parameters instead.  */
52void (*error_print_progname) (void);
53
54/* This variable is incremented each time `error' is called.  */
55unsigned int error_message_count;
56
57#ifdef _LIBC
58/* In the GNU C library, there is a predefined variable for this.  */
59
60# define program_name program_invocation_name
61# include <errno.h>
62# include <libio/libioP.h>
63
64/* In GNU libc we want do not want to use the common name `error' directly.
65   Instead make it a weak alias.  */
66extern void __error (int status, int errnum, const char *message, ...)
67     __attribute__ ((__format__ (__printf__, 3, 4)));
68extern void __error_at_line (int status, int errnum, const char *file_name,
69			     unsigned int line_number, const char *message,
70			     ...)
71     __attribute__ ((__format__ (__printf__, 5, 6)));;
72# define error __error
73# define error_at_line __error_at_line
74
75# include <libio/iolibio.h>
76# define fflush(s) INTUSE(_IO_fflush) (s)
77# undef putc
78# define putc(c, fp) INTUSE(_IO_putc) (c, fp)
79
80# include <bits/libc-lock.h>
81
82#else /* not _LIBC */
83
84# if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
85#  ifndef HAVE_DECL_STRERROR_R
86"this configure-time declaration test was not run"
87#  endif
88char *strerror_r ();
89# endif
90
91# ifndef SIZE_MAX
92#  define SIZE_MAX ((size_t) -1)
93# endif
94
95/* The calling program should define program_name and set it to the
96   name of the executing program.  */
97extern char *program_name;
98
99# if HAVE_STRERROR_R || defined strerror_r
100#  define __strerror_r strerror_r
101# endif
102#endif	/* not _LIBC */
103
104static void
105print_errno_message (int errnum)
106{
107  char const *s = NULL;
108
109#if defined HAVE_STRERROR_R || _LIBC
110  char errbuf[1024];
111# if STRERROR_R_CHAR_P || _LIBC
112  s = __strerror_r (errnum, errbuf, sizeof errbuf);
113# else
114  if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
115    s = errbuf;
116# endif
117#endif
118
119#if !_LIBC
120  if (! s && ! (s = strerror (errnum)))
121    s = _("Unknown system error");
122#endif
123
124#if _LIBC
125  if (_IO_fwide (stderr, 0) > 0)
126    {
127      __fwprintf (stderr, L": %s", s);
128      return;
129    }
130#endif
131
132  fprintf (stderr, ": %s", s);
133}
134
135static void
136error_tail (int status, int errnum, const char *message, va_list args)
137{
138#if _LIBC
139  if (_IO_fwide (stderr, 0) > 0)
140    {
141# define ALLOCA_LIMIT 2000
142      size_t len = strlen (message) + 1;
143      const wchar_t *wmessage = L"out of memory";
144      wchar_t *wbuf = (len < ALLOCA_LIMIT
145		       ? alloca (len * sizeof *wbuf)
146		       : len <= SIZE_MAX / sizeof *wbuf
147		       ? malloc (len * sizeof *wbuf)
148		       : NULL);
149
150      if (wbuf)
151	{
152	  size_t res;
153	  mbstate_t st;
154	  const char *tmp = message;
155	  memset (&st, '\0', sizeof (st));
156	  res = mbsrtowcs (wbuf, &tmp, len, &st);
157	  wmessage = res == (size_t) -1 ? L"???" : wbuf;
158	}
159
160      __vfwprintf (stderr, wmessage, args);
161      if (! (len < ALLOCA_LIMIT))
162	free (wbuf);
163    }
164  else
165#endif
166    vfprintf (stderr, message, args);
167  va_end (args);
168
169  ++error_message_count;
170  if (errnum)
171    print_errno_message (errnum);
172#if _LIBC
173  if (_IO_fwide (stderr, 0) > 0)
174    putwc (L'\n', stderr);
175  else
176#endif
177    putc ('\n', stderr);
178  fflush (stderr);
179  if (status)
180    exit (status);
181}
182
183
184/* Print the program name and error message MESSAGE, which is a printf-style
185   format string with optional args.
186   If ERRNUM is nonzero, print its corresponding system error message.
187   Exit with status STATUS if it is nonzero.  */
188void
189error (int status, int errnum, const char *message, ...)
190{
191  va_list args;
192
193#if defined _LIBC && defined __libc_ptf_call
194  /* We do not want this call to be cut short by a thread
195     cancellation.  Therefore disable cancellation for now.  */
196  int state = PTHREAD_CANCEL_ENABLE;
197  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
198		   0);
199#endif
200
201  fflush (stdout);
202#ifdef _LIBC
203  _IO_flockfile (stderr);
204#endif
205  if (error_print_progname)
206    (*error_print_progname) ();
207  else
208    {
209#if _LIBC
210      if (_IO_fwide (stderr, 0) > 0)
211	__fwprintf (stderr, L"%s: ", program_name);
212      else
213#endif
214	fprintf (stderr, "%s: ", program_name);
215    }
216
217  va_start (args, message);
218  error_tail (status, errnum, message, args);
219
220#ifdef _LIBC
221  _IO_funlockfile (stderr);
222# ifdef __libc_ptf_call
223  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
224# endif
225#endif
226}
227
228/* Sometimes we want to have at most one error per line.  This
229   variable controls whether this mode is selected or not.  */
230int error_one_per_line;
231
232void
233error_at_line (int status, int errnum, const char *file_name,
234	       unsigned int line_number, const char *message, ...)
235{
236  va_list args;
237
238  if (error_one_per_line)
239    {
240      static const char *old_file_name;
241      static unsigned int old_line_number;
242
243      if (old_line_number == line_number
244	  && (file_name == old_file_name
245	      || strcmp (old_file_name, file_name) == 0))
246	/* Simply return and print nothing.  */
247	return;
248
249      old_file_name = file_name;
250      old_line_number = line_number;
251    }
252
253#if defined _LIBC && defined __libc_ptf_call
254  /* We do not want this call to be cut short by a thread
255     cancellation.  Therefore disable cancellation for now.  */
256  int state = PTHREAD_CANCEL_ENABLE;
257  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
258		   0);
259#endif
260
261  fflush (stdout);
262#ifdef _LIBC
263  _IO_flockfile (stderr);
264#endif
265  if (error_print_progname)
266    (*error_print_progname) ();
267  else
268    {
269#if _LIBC
270      if (_IO_fwide (stderr, 0) > 0)
271	__fwprintf (stderr, L"%s: ", program_name);
272      else
273#endif
274	fprintf (stderr, "%s:", program_name);
275    }
276
277  if (file_name != NULL)
278    {
279#if _LIBC
280      if (_IO_fwide (stderr, 0) > 0)
281	__fwprintf (stderr, L"%s:%d: ", file_name, line_number);
282      else
283#endif
284	fprintf (stderr, "%s:%d: ", file_name, line_number);
285    }
286
287  va_start (args, message);
288  error_tail (status, errnum, message, args);
289
290#ifdef _LIBC
291  _IO_funlockfile (stderr);
292# ifdef __libc_ptf_call
293  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
294# endif
295#endif
296}
297
298#ifdef _LIBC
299/* Make the weak alias.  */
300# undef error
301# undef error_at_line
302weak_alias (__error, error)
303weak_alias (__error_at_line, error_at_line)
304#endif
305