sendmail/libsm/assert.c

/*
 * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
 *  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sm/gen.h>
SM_RCSID("@(#)$Id: assert.c,v 1.25.2.1 2003/12/05 22:44:17 ca Exp $")

/*
**  Abnormal program termination and assertion checking.
**  For documentation, see assert.html.
*/

#include <signal.h>
#include <stdlib.h>
#include <unistd.h>

#include <sm/assert.h>
#include <sm/exc.h>
#include <sm/io.h>
#include <sm/varargs.h>

/*
**  Debug categories that are used to guard expensive assertion checks.
*/

SM_DEBUG_T SmExpensiveAssert = SM_DEBUG_INITIALIZER("sm_check_assert",
    "@(#)$Debug: sm_check_assert - check assertions $");

SM_DEBUG_T SmExpensiveRequire = SM_DEBUG_INITIALIZER("sm_check_require",
    "@(#)$Debug: sm_check_require - check function preconditions $");

SM_DEBUG_T SmExpensiveEnsure = SM_DEBUG_INITIALIZER("sm_check_ensure",
    "@(#)$Debug: sm_check_ensure - check function postconditions $");

/*
**  Debug category: send self SIGSTOP on fatal error,
**  so that you can run a debugger on the stopped process.
*/

SM_DEBUG_T SmAbortStop = SM_DEBUG_INITIALIZER("sm_abort_stop",
    "@(#)$Debug: sm_abort_stop - stop process on fatal error $");

/*
**  SM_ABORT_DEFAULTHANDLER -- Default procedure for abnormal program
**              termination.
**
**  The goal is to display an error message without disturbing the
**  process state too much, then dump core.
**
**  Parameters:
**      filename -- filename (can be NULL).
**      lineno -- line number.
**      msg -- message.
**
**  Returns:
**      doesn't return.
*/

static void
sm_abort_defaulthandler __P((
    const char *filename,
    int lineno,
    const char *msg));

static void
sm_abort_defaulthandler(filename, lineno, msg)
    const char *filename;
    int lineno;
    const char *msg;
{
    if (filename != NULL)
        sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s:%d: %s\n", filename,
                  lineno, msg);
    else
        sm_io_fprintf(smioerr, SM_TIME_DEFAULT, "%s\n", msg);
    sm_io_flush(smioerr, SM_TIME_DEFAULT);
#ifdef SIGSTOP
    if (sm_debug_active(&SmAbortStop, 1))
        kill(getpid(), SIGSTOP);
#endif /* SIGSTOP */
    abort();
}

/*
**  This is the action to be taken to cause abnormal program termination.
*/

static SM_ABORT_HANDLER_T SmAbortHandler = sm_abort_defaulthandler;

/*
**  SM_ABORT_SETHANDLER -- Set handler for SM_ABORT()
**
**  This allows you to set a handler function for causing abnormal
**  program termination; it is called when a logic bug is detected.
**
**  Parameters:
**      f -- handler.
**
**  Returns:
**      none.
*/

void
sm_abort_sethandler(f)
    SM_ABORT_HANDLER_T f;
{
    if (f == NULL)
        SmAbortHandler = sm_abort_defaulthandler;
    else
        SmAbortHandler = f;
}

/*
**  SM_ABORT -- Call it when you have detected a logic bug.
**
**  Parameters:
**      fmt -- format string.
**      ... -- arguments.
**
**  Returns:
**      doesn't.
*/

void SM_DEAD_D
#if SM_VA_STD
sm_abort(char *fmt, ...)
#else /* SM_VA_STD */
sm_abort(fmt, va_alist)
    char *fmt;
    va_dcl
#endif /* SM_VA_STD */
{
    char msg[128];
    SM_VA_LOCAL_DECL

    SM_VA_START(ap, fmt);
    sm_vsnprintf(msg, sizeof msg, fmt, ap);
    SM_VA_END(ap);
    sm_abort_at(NULL, 0, msg);
}

/*
**  SM_ABORT_AT -- Initiate abnormal program termination.
**
**  This is the low level function that is called to initiate abnormal
**  program termination.  It prints an error message and terminates the
**  program.  It is called by sm_abort and by the assertion macros.
**  If filename != NULL then filename and lineno specify the line of source
**  code at which the bug was detected.
**
**  Parameters:
**      filename -- filename (can be NULL).
**      lineno -- line number.
**      msg -- message.
**
**  Returns:
**      doesn't.
*/

void SM_DEAD_D
sm_abort_at(filename, lineno, msg)
    const char *filename;
    int lineno;
    const char *msg;
{
    SM_TRY
        (*SmAbortHandler)(filename, lineno, msg);
    SM_EXCEPT(exc, "*")
        sm_io_fprintf(smioerr, SM_TIME_DEFAULT,
                  "exception raised by abort handler:\n");
        sm_exc_print(exc, smioerr);
        sm_io_flush(smioerr, SM_TIME_DEFAULT);
    SM_END_TRY

    /*
    **  SmAbortHandler isn't supposed to return.
    **  Since it has, let's make sure that the program is terminated.
    */

    abort();
}