assert/assert.c

   1 /* Copyright (C) 1991,1994-1996,1998,2001,2002,2005,2009,2011
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <assert.h>
  21 #include <atomic.h>
  22 #include <ldsodefs.h>
  23 #include <libintl.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <sysdep.h>
  27 #include <unistd.h>
  28 #include <sys/mman.h>
  29
  30
  31 extern const char *__progname;
  32
  33 #ifdef USE_IN_LIBIO
  34 # include <wchar.h>
  35 # include <libio/iolibio.h>
  36 # define fflush(s) INTUSE(_IO_fflush) (s)
  37 #endif
  38
  39 /* This function, when passed a string containing an asserted
  40    expression, a filename, and a line number, prints a message
  41    on the standard error stream of the form:
  42         a.c:10: foobar: Assertion `a == b' failed.
  43    It then aborts program execution via a call to `abort'.  */
  44
  45 #ifdef FATAL_PREPARE_INCLUDE
  46 # include FATAL_PREPARE_INCLUDE
  47 #endif
  48
  49
  50 void
  51 __assert_fail_base (const char *fmt, const char *assertion, const char *file,
  52                     unsigned int line, const char *function)
  53 {
  54   char *str;
  55
  56 #ifdef FATAL_PREPARE
  57   FATAL_PREPARE;
  58 #endif
  59
  60   int total;
  61   if (__asprintf (&str, fmt,
  62                   __progname, __progname[0] ? ": " : "",
  63                   file, line,
  64                   function ? function : "", function ? ": " : "",
  65                   assertion, &total) >= 0)
  66     {
  67       /* Print the message.  */
  68       (void) __fxprintf (NULL, "%s", str);
  69       (void) fflush (stderr);
  70
  71       total = (total + 1 + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1);
  72       struct abort_msg_s *buf = __mmap (NULL, total, PROT_READ | PROT_WRITE,
  73                                         MAP_ANON | MAP_PRIVATE, -1, 0);
  74       if (__builtin_expect (buf != MAP_FAILED, 1))
  75         {
  76           buf->size = total;
  77           strcpy (buf->msg, str);
  78
  79           /* We have to free the old buffer since the application might
  80              catch the SIGABRT signal.  */
  81           struct abort_msg_s *old = atomic_exchange_acq (&__abort_msg, buf);
  82
  83           if (old != NULL)
  84             __munmap (old, old->size);
  85         }
  86
  87       free (str);
  88     }
  89   else
  90     {
  91       /* At least print a minimal message.  */
  92       static const char errstr[] = "Unexpected error.\n";
  93       __libc_write (STDERR_FILENO, errstr, sizeof (errstr) - 1);
  94     }
  95
  96   abort ();
  97 }
  98
  99
 100 #undef __assert_fail
 101 void
 102 __assert_fail (const char *assertion, const char *file, unsigned int line,
 103                const char *function)
 104 {
 105   __assert_fail_base (_("%s%s%s:%u: %s%sAssertion `%s' failed.\n%n"),
 106                       assertion, file, line, function);
 107 }
 108 hidden_def(__assert_fail)