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#include <sys/cdefs.h>
19__RCSID("$NetBSD: error.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
20
21
22/* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
23
24#ifdef HAVE_CONFIG_H
25# include <config.h>
26#endif
27
28#include "error.h"
29
30#include <stdarg.h>
31#include <stdio.h>
32#include <stdlib.h>
33#include <string.h>
34
35#if !_LIBC && ENABLE_NLS
36# include "gettext.h"
37#endif
38
39#ifdef _LIBC
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 <libio/libioP.h>
66
67/* In GNU libc we want do not want to use the common name `error' directly.
68   Instead make it a weak alias.  */
69extern void __error (int status, int errnum, const char *message, ...)
70     __attribute__ ((__format__ (__printf__, 3, 4)));
71extern void __error_at_line (int status, int errnum, const char *file_name,
72			     unsigned int line_number, const char *message,
73			     ...)
74     __attribute__ ((__format__ (__printf__, 5, 6)));;
75# define error __error
76# define error_at_line __error_at_line
77
78# include <libio/iolibio.h>
79# define fflush(s) INTUSE(_IO_fflush) (s)
80# undef putc
81# define putc(c, fp) INTUSE(_IO_putc) (c, fp)
82
83# include <bits/libc-lock.h>
84
85#else /* not _LIBC */
86
87# if !HAVE_DECL_STRERROR_R && STRERROR_R_CHAR_P
88#  ifndef HAVE_DECL_STRERROR_R
89"this configure-time declaration test was not run"
90#  endif
91char *strerror_r ();
92# endif
93
94# ifndef SIZE_MAX
95#  define SIZE_MAX ((size_t) -1)
96# endif
97
98/* The calling program should define program_name and set it to the
99   name of the executing program.  */
100extern char *program_name;
101
102# if HAVE_STRERROR_R || defined strerror_r
103#  define __strerror_r strerror_r
104# endif
105#endif	/* not _LIBC */
106
107static void
108print_errno_message (int errnum)
109{
110  char const *s = NULL;
111
112#if defined HAVE_STRERROR_R || _LIBC
113  char errbuf[1024];
114# if STRERROR_R_CHAR_P || _LIBC
115  s = __strerror_r (errnum, errbuf, sizeof errbuf);
116# else
117  if (__strerror_r (errnum, errbuf, sizeof errbuf) == 0)
118    s = errbuf;
119# endif
120#endif
121
122#if !_LIBC
123  if (! s && ! (s = strerror (errnum)))
124    s = _("Unknown system error");
125#endif
126
127#if _LIBC
128  if (_IO_fwide (stderr, 0) > 0)
129    {
130      __fwprintf (stderr, L": %s", s);
131      return;
132    }
133#endif
134
135  fprintf (stderr, ": %s", s);
136}
137
138static void
139error_tail (int status, int errnum, const char *message, va_list args)
140{
141#if _LIBC
142  if (_IO_fwide (stderr, 0) > 0)
143    {
144# define ALLOCA_LIMIT 2000
145      size_t len = strlen (message) + 1;
146      const wchar_t *wmessage = L"out of memory";
147      wchar_t *wbuf = (len < ALLOCA_LIMIT
148		       ? alloca (len * sizeof *wbuf)
149		       : len <= SIZE_MAX / sizeof *wbuf
150		       ? malloc (len * sizeof *wbuf)
151		       : NULL);
152
153      if (wbuf)
154	{
155	  size_t res;
156	  mbstate_t st;
157	  const char *tmp = message;
158	  memset (&st, '\0', sizeof (st));
159	  res = mbsrtowcs (wbuf, &tmp, len, &st);
160	  wmessage = res == (size_t) -1 ? L"???" : wbuf;
161	}
162
163      __vfwprintf (stderr, wmessage, args);
164      if (! (len < ALLOCA_LIMIT))
165	free (wbuf);
166    }
167  else
168#endif
169    vfprintf (stderr, message, args);
170  va_end (args);
171
172  ++error_message_count;
173  if (errnum)
174    print_errno_message (errnum);
175#if _LIBC
176  if (_IO_fwide (stderr, 0) > 0)
177    putwc (L'\n', stderr);
178  else
179#endif
180    putc ('\n', stderr);
181  fflush (stderr);
182  if (status)
183    exit (status);
184}
185
186
187/* Print the program name and error message MESSAGE, which is a printf-style
188   format string with optional args.
189   If ERRNUM is nonzero, print its corresponding system error message.
190   Exit with status STATUS if it is nonzero.  */
191void
192error (int status, int errnum, const char *message, ...)
193{
194  va_list args;
195
196#if defined _LIBC && defined __libc_ptf_call
197  /* We do not want this call to be cut short by a thread
198     cancellation.  Therefore disable cancellation for now.  */
199  int state = PTHREAD_CANCEL_ENABLE;
200  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
201		   0);
202#endif
203
204  fflush (stdout);
205#ifdef _LIBC
206  _IO_flockfile (stderr);
207#endif
208  if (error_print_progname)
209    (*error_print_progname) ();
210  else
211    {
212#if _LIBC
213      if (_IO_fwide (stderr, 0) > 0)
214	__fwprintf (stderr, L"%s: ", program_name);
215      else
216#endif
217	fprintf (stderr, "%s: ", program_name);
218    }
219
220  va_start (args, message);
221  error_tail (status, errnum, message, args);
222
223#ifdef _LIBC
224  _IO_funlockfile (stderr);
225# ifdef __libc_ptf_call
226  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
227# endif
228#endif
229}
230
231/* Sometimes we want to have at most one error per line.  This
232   variable controls whether this mode is selected or not.  */
233int error_one_per_line;
234
235void
236error_at_line (int status, int errnum, const char *file_name,
237	       unsigned int line_number, const char *message, ...)
238{
239  va_list args;
240
241  if (error_one_per_line)
242    {
243      static const char *old_file_name;
244      static unsigned int old_line_number;
245
246      if (old_line_number == line_number
247	  && (file_name == old_file_name
248	      || strcmp (old_file_name, file_name) == 0))
249	/* Simply return and print nothing.  */
250	return;
251
252      old_file_name = file_name;
253      old_line_number = line_number;
254    }
255
256#if defined _LIBC && defined __libc_ptf_call
257  /* We do not want this call to be cut short by a thread
258     cancellation.  Therefore disable cancellation for now.  */
259  int state = PTHREAD_CANCEL_ENABLE;
260  __libc_ptf_call (pthread_setcancelstate, (PTHREAD_CANCEL_DISABLE, &state),
261		   0);
262#endif
263
264  fflush (stdout);
265#ifdef _LIBC
266  _IO_flockfile (stderr);
267#endif
268  if (error_print_progname)
269    (*error_print_progname) ();
270  else
271    {
272#if _LIBC
273      if (_IO_fwide (stderr, 0) > 0)
274	__fwprintf (stderr, L"%s: ", program_name);
275      else
276#endif
277	fprintf (stderr, "%s:", program_name);
278    }
279
280  if (file_name != NULL)
281    {
282#if _LIBC
283      if (_IO_fwide (stderr, 0) > 0)
284	__fwprintf (stderr, L"%s:%d: ", file_name, line_number);
285      else
286#endif
287	fprintf (stderr, "%s:%d: ", file_name, line_number);
288    }
289
290  va_start (args, message);
291  error_tail (status, errnum, message, args);
292
293#ifdef _LIBC
294  _IO_funlockfile (stderr);
295# ifdef __libc_ptf_call
296  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
297# endif
298#endif
299}
300
301#ifdef _LIBC
302/* Make the weak alias.  */
303# undef error
304# undef error_at_line
305weak_alias (__error, error)
306weak_alias (__error_at_line, error_at_line)
307#endif
308