usr/src/cmd/sendmail/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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  12
  13 #include <sm/gen.h>
  14 SM_RCSID("@(#)$Id: assert.c,v 1.25.2.1 2003/12/05 22:44:17 ca Exp $")
  15
  16 /*
  17 **  Abnormal program termination and assertion checking.
  18 **  For documentation, see assert.html.
  19 */
  20
  21 #include <signal.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24
  25 #include <sm/assert.h>
  26 #include <sm/exc.h>
  27 #include <sm/io.h>
  28 #include <sm/varargs.h>
  29
  30 /*
  31 **  Debug categories that are used to guard expensive assertion checks.
  32 */
  33
  34 SM_DEBUG_T SmExpensiveAssert = SM_DEBUG_INITIALIZER("sm_check_assert",
  35         "@(#)$Debug: sm_check_assert - check assertions $");
  36
  37 SM_DEBUG_T SmExpensiveRequire = SM_DEBUG_INITIALIZER("sm_check_require",
  38         "@(#)$Debug: sm_check_require - check function preconditions $");
  39
  40 SM_DEBUG_T SmExpensiveEnsure = SM_DEBUG_INITIALIZER("sm_check_ensure",
  41         "@(#)$Debug: sm_check_ensure - check function postconditions $");
  42
  43 /*
  44 **  Debug category: send self SIGSTOP on fatal error,
  45 **  so that you can run a debugger on the stopped process.
  46 */
  47
  48 SM_DEBUG_T SmAbortStop = SM_DEBUG_INITIALIZER("sm_abort_stop",
  49         "@(#)$Debug: sm_abort_stop - stop process on fatal error $");
  50
  51 /*
  52 **  SM_ABORT_DEFAULTHANDLER -- Default procedure for abnormal program
  53 **                              termination.
  54 **
  55 **      The goal is to display an error message without disturbing the
  56 **      process state too much, then dump core.
  57 **
  58 **      Parameters:
  59 **              filename -- filename (can be NULL).
  60 **              lineno -- line number.
  61 **              msg -- message.
  62 **
  63 **      Returns:
  64 **              doesn't return.
  65 */
  66
  67 static void
  68 sm_abort_defaulthandler __P((
  69         const char *filename,
  70         int lineno,
  71         const char *msg));
  72
  73 static void
  74 sm_abort_defaulthandler(filename, lineno, msg)
  75         const char *filename;
  76         int lineno;
  77         const char *msg;
  78 {
  79         if (filename != NULL)
  80                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s:%d: %s\n", filename,
  81                               lineno, msg);
  82         else
  83                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s\n", msg);
  84         sm_io_flush(smioerr, SM_TIME_DEFAULT);
  85 #ifdef SIGSTOP
  86         if (sm_debug_active(&SmAbortStop, 1))
  87                 kill(getpid(), SIGSTOP);
  88 #endif /* SIGSTOP */
  89         abort();
  90 }
  91
  92 /*
  93 **  This is the action to be taken to cause abnormal program termination.
  94 */
  95
  96 static SM_ABORT_HANDLER_T SmAbortHandler = sm_abort_defaulthandler;
  97
  98 /*
  99 **  SM_ABORT_SETHANDLER -- Set handler for SM_ABORT()
 100 **
 101 **      This allows you to set a handler function for causing abnormal
 102 **      program termination; it is called when a logic bug is detected.
 103 **
 104 **      Parameters:
 105 **              f -- handler.
 106 **
 107 **      Returns:
 108 **              none.
 109 */
 110
 111 void
 112 sm_abort_sethandler(f)
 113         SM_ABORT_HANDLER_T f;
 114 {
 115         if (f == NULL)
 116                 SmAbortHandler = sm_abort_defaulthandler;
 117         else
 118                 SmAbortHandler = f;
 119 }
 120
 121 /*
 122 **  SM_ABORT -- Call it when you have detected a logic bug.
 123 **
 124 **      Parameters:
 125 **              fmt -- format string.
 126 **              ... -- arguments.
 127 **
 128 **      Returns:
 129 **              doesn't.
 130 */
 131
 132 void SM_DEAD_D
 133 #if SM_VA_STD
 134 sm_abort(char *fmt, ...)
 135 #else /* SM_VA_STD */
 136 sm_abort(fmt, va_alist)
 137         char *fmt;
 138         va_dcl
 139 #endif /* SM_VA_STD */
 140 {
 141         char msg[128];
 142         SM_VA_LOCAL_DECL
 143
 144         SM_VA_START(ap, fmt);
 145         sm_vsnprintf(msg, sizeof msg, fmt, ap);
 146         SM_VA_END(ap);
 147         sm_abort_at(NULL, 0, msg);
 148 }
 149
 150 /*
 151 **  SM_ABORT_AT -- Initiate abnormal program termination.
 152 **
 153 **      This is the low level function that is called to initiate abnormal
 154 **      program termination.  It prints an error message and terminates the
 155 **      program.  It is called by sm_abort and by the assertion macros.
 156 **      If filename != NULL then filename and lineno specify the line of source
 157 **      code at which the bug was detected.
 158 **
 159 **      Parameters:
 160 **              filename -- filename (can be NULL).
 161 **              lineno -- line number.
 162 **              msg -- message.
 163 **
 164 **      Returns:
 165 **              doesn't.
 166 */
 167
 168 void SM_DEAD_D
 169 sm_abort_at(filename, lineno, msg)
 170         const char *filename;
 171         int lineno;
 172         const char *msg;
 173 {
 174         SM_TRY
 175                 (*SmAbortHandler)(filename, lineno, msg);
 176         SM_EXCEPT(exc, "*")
 177                 sm_io_fprintf(smioerr, SM_TIME_DEFAULT,
 178                               "exception raised by abort handler:\n");
 179                 sm_exc_print(exc, smioerr);
 180                 sm_io_flush(smioerr, SM_TIME_DEFAULT);
 181         SM_END_TRY
 182
 183         /*
 184         **  SmAbortHandler isn't supposed to return.
 185         **  Since it has, let's make sure that the program is terminated.
 186         */
 187
 188         abort();
 189 }