/*
 * 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.
 *
 */

#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();
}