contrib/sendmail-8.13.4/libsm/assert.c

   1 /*
   2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  *
   9  */
  10
  11 #include <sm/gen.h>
  12 SM_RCSID("@(#)$Id: assert.c,v 1.26 2003/12/05 22:45:24 ca Exp $")
  13
  14 /*
  15 **  Abnormal program termination and assertion checking.
  16 **  For documentation, see assert.html.
  17 */
  18
  19 #include <signal.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22
  23 #include <sm/assert.h>
  24 #include <sm/exc.h>
  25 #include <sm/io.h>
  26 #include <sm/varargs.h>
  27
  28 /*
  29 **  Debug categories that are used to guard expensive assertion checks.
  30 */
  31
  32 SM_DEBUG_T SmExpensiveAssert = SM_DEBUG_INITIALIZER("sm_check_assert",
  33         "@(#)$Debug: sm_check_assert - check assertions $");
  34
  35 SM_DEBUG_T SmExpensiveRequire = SM_DEBUG_INITIALIZER("sm_check_require",
  36         "@(#)$Debug: sm_check_require - check function preconditions $");
  37
  38 SM_DEBUG_T SmExpensiveEnsure = SM_DEBUG_INITIALIZER("sm_check_ensure",
  39         "@(#)$Debug: sm_check_ensure - check function postconditions $");
  40
  41 /*
  42 **  Debug category: send self SIGSTOP on fatal error,
  43 **  so that you can run a debugger on the stopped process.
  44 */
  45
  46 SM_DEBUG_T SmAbortStop = SM_DEBUG_INITIALIZER("sm_abort_stop",
  47         "@(#)$Debug: sm_abort_stop - stop process on fatal error $");
  48
  49 /*
  50 **  SM_ABORT_DEFAULTHANDLER -- Default procedure for abnormal program
  51 **                              termination.
  52 **
  53 **      The goal is to display an error message without disturbing the
  54 **      process state too much, then dump core.
  55 **
  56 **      Parameters:
  57 **              filename -- filename (can be NULL).
  58 **              lineno -- line number.
  59 **              msg -- message.
  60 **
  61 **      Returns:
  62 **              doesn't return.
  63 */
  64
  65 static void
  66 sm_abort_defaulthandler __P((
  67         const char *filename,
  68         int lineno,
  69         const char *msg));
  70
  71 static void
  72 sm_abort_defaulthandler(filename, lineno, msg)
  73         const char *filename;
  74         int lineno;
  75         const char *msg;
  76 {
  77         if (filename != NULL)
  78                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s:%d: %s\n", filename,
  79                               lineno, msg);
  80         else
  81                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s\n", msg);
  82         sm_io_flush(smioerr, SM_TIME_DEFAULT);
  83 #ifdef SIGSTOP
  84         if (sm_debug_active(&SmAbortStop, 1))
  85                 kill(getpid(), SIGSTOP);
  86 #endif /* SIGSTOP */
  87         abort();
  88 }
  89
  90 /*
  91 **  This is the action to be taken to cause abnormal program termination.
  92 */
  93
  94 static SM_ABORT_HANDLER_T SmAbortHandler = sm_abort_defaulthandler;
  95
  96 /*
  97 **  SM_ABORT_SETHANDLER -- Set handler for SM_ABORT()
  98 **
  99 **      This allows you to set a handler function for causing abnormal
 100 **      program termination; it is called when a logic bug is detected.
 101 **
 102 **      Parameters:
 103 **              f -- handler.
 104 **
 105 **      Returns:
 106 **              none.
 107 */
 108
 109 void
 110 sm_abort_sethandler(f)
 111         SM_ABORT_HANDLER_T f;
 112 {
 113         if (f == NULL)
 114                 SmAbortHandler = sm_abort_defaulthandler;
 115         else
 116                 SmAbortHandler = f;
 117 }
 118
 119 /*
 120 **  SM_ABORT -- Call it when you have detected a logic bug.
 121 **
 122 **      Parameters:
 123 **              fmt -- format string.
 124 **              ... -- arguments.
 125 **
 126 **      Returns:
 127 **              doesn't.
 128 */
 129
 130 void SM_DEAD_D
 131 #if SM_VA_STD
 132 sm_abort(char *fmt, ...)
 133 #else /* SM_VA_STD */
 134 sm_abort(fmt, va_alist)
 135         char *fmt;
 136         va_dcl
 137 #endif /* SM_VA_STD */
 138 {
 139         char msg[128];
 140         SM_VA_LOCAL_DECL
 141
 142         SM_VA_START(ap, fmt);
 143         sm_vsnprintf(msg, sizeof msg, fmt, ap);
 144         SM_VA_END(ap);
 145         sm_abort_at(NULL, 0, msg);
 146 }
 147
 148 /*
 149 **  SM_ABORT_AT -- Initiate abnormal program termination.
 150 **
 151 **      This is the low level function that is called to initiate abnormal
 152 **      program termination.  It prints an error message and terminates the
 153 **      program.  It is called by sm_abort and by the assertion macros.
 154 **      If filename != NULL then filename and lineno specify the line of source
 155 **      code at which the bug was detected.
 156 **
 157 **      Parameters:
 158 **              filename -- filename (can be NULL).
 159 **              lineno -- line number.
 160 **              msg -- message.
 161 **
 162 **      Returns:
 163 **              doesn't.
 164 */
 165
 166 void SM_DEAD_D
 167 sm_abort_at(filename, lineno, msg)
 168         const char *filename;
 169         int lineno;
 170         const char *msg;
 171 {
 172         SM_TRY
 173                 (*SmAbortHandler)(filename, lineno, msg);
 174         SM_EXCEPT(exc, "*")
 175                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT,
 176                               "exception raised by abort handler:\n");
 177                 sm_exc_print(exc, smioerr);
 178                 sm_io_flush(smioerr, SM_TIME_DEFAULT);
 179         SM_END_TRY
 180
 181         /*
 182         **  SmAbortHandler isn't supposed to return.
 183         **  Since it has, let's make sure that the program is terminated.
 184         */
 185
 186         abort();
 187 }