/* "Larn is copyrighted 1986 by Noah Morgan.\n" */

#include <signal.h>
#include "header.h"

static void s2choose(void);
static void cntlc(int);
static void sgam(int);
#ifdef SIGTSTP
static void tstop(int);
#endif
static void sigill(int);
static void sigtrap(int);
static void sigiot(int);
static void sigemt(int);
static void sigfpe(int);
static void sigbus(int);
static void sigsegv(int);
static void sigsys(int);
static void sigpipe(int);
static void sigterm(int);
static void sigpanic(int);

#define BIT(a) (1<<((a)-1))

static void
s2choose(void)  /* text to be displayed if ^C during intro screen */
{
        cursor(1, 24);
        lprcat("Press ");
        setbold();
        lprcat("return");
        resetbold();
        lprcat(" to continue: ");
        lflush();
}

static void
cntlc(__unused int sig) /* what to do for a ^C */
{
        if (nosignal)   /* don't do anything if inhibited */
                return;
        signal(SIGQUIT, SIG_IGN);
        signal(SIGINT, SIG_IGN);
        quit();
        if (predostuff == 1)
                s2choose();
        else
                showplayer();
        lflush();
        signal(SIGQUIT, cntlc);
        signal(SIGINT, cntlc);
}

/*
 *      subroutine to save the game if a hangup signal
 */
static void
sgam(__unused int sig)
{
        savegame(savefilename);
        wizard = 1;
        died(-257);             /* hangup signal */
}

#ifdef SIGTSTP
static void
tstop(__unused int sig) /* control Y */
{
        if (nosignal)           /* nothing if inhibited */
                return;
        lcreat(NULL);
        clearvt100();
        lflush();
        signal(SIGTSTP, SIG_DFL);
#ifdef SIGVTALRM
        /* looks like BSD4.2 or higher - must clr mask for signal to take effect*/
        sigsetmask(sigblock(0) & ~BIT(SIGTSTP));
#endif
        kill(getpid(), SIGTSTP);

        setupvt100();
        signal(SIGTSTP, tstop);
        if (predostuff == 1)
                s2choose();
        else
                drawscreen();
        showplayer();
        lflush();
}
#endif /* SIGTSTP */

/*
 *      subroutine to issue the needed signal traps  called from main()
 */
static void
sigill(__unused int sig)
{
        sigpanic(SIGILL);
}

static void
sigtrap(__unused int sig)
{
        sigpanic(SIGTRAP);
}

static void
sigiot(__unused int sig)
{
        sigpanic(SIGIOT);
}

static void
sigemt(__unused int sig)
{
        sigpanic(SIGEMT);
}

static void
sigfpe(__unused int sig)
{
        sigpanic(SIGFPE);
}

static void
sigbus(__unused int sig)
{
        sigpanic(SIGBUS);
}

static void
sigsegv(__unused int sig)
{
        sigpanic(SIGSEGV);
}

static void
sigsys(__unused int sig)
{
        sigpanic(SIGSYS);
}

static void
sigpipe(__unused int sig)
{
        sigpanic(SIGPIPE);
}

static void
sigterm(__unused int sig)
{
        sigpanic(SIGTERM);
}

void
sigsetup(void)
{
        signal(SIGQUIT, cntlc);
        signal(SIGINT, cntlc);
        signal(SIGKILL, SIG_IGN);
        signal(SIGHUP, sgam);
        signal(SIGILL, sigill);
        signal(SIGTRAP, sigtrap);
        signal(SIGIOT, sigiot);
        signal(SIGEMT, sigemt);
        signal(SIGFPE, sigfpe);
        signal(SIGBUS, sigbus);
        signal(SIGSEGV, sigsegv);
        signal(SIGSYS, sigsys);
        signal(SIGPIPE, sigpipe);
        signal(SIGTERM, sigterm);
#ifdef SIGTSTP
        signal(SIGTSTP, tstop);
        signal(SIGSTOP, tstop);
#endif /* SIGTSTP */
}

static const char *signame[NSIG] = { "",
"SIGHUP",  /*   1       hangup */
"SIGINT",  /*   2       interrupt */
"SIGQUIT", /*   3       quit */
"SIGILL",  /*   4       illegal instruction (not reset when caught) */
"SIGTRAP", /*   5       trace trap (not reset when caught) */
"SIGIOT",  /*   6       IOT instruction */
"SIGEMT",  /*   7       EMT instruction */
"SIGFPE",  /*   8       floating point exception */
"SIGKILL", /*   9       kill (cannot be caught or ignored) */
"SIGBUS",  /*  10       bus error */
"SIGSEGV", /*  11       segmentation violation */
"SIGSYS",  /*  12       bad argument to system call */
"SIGPIPE", /*  13       write on a pipe with no one to read it */
"SIGALRM", /*  14       alarm clock */
"SIGTERM", /*  15       software termination signal from kill */
"SIGURG",  /*  16       urgent condition on IO channel */
"SIGSTOP", /*  17       sendable stop signal not from tty */
"SIGTSTP", /*  18       stop signal from tty */
"SIGCONT", /*  19       continue a stopped process */
"SIGCHLD", /*  20       to parent on child stop or exit */
"SIGTTIN", /*  21       to readers pgrp upon background tty read */
"SIGTTOU", /*  22       like TTIN for output if (tp->t_local&LTOSTOP) */
"SIGIO",   /*  23       input/output possible signal */
"SIGXCPU", /*  24       exceeded CPU time limit */
"SIGXFSZ", /*  25       exceeded file size limit */
"SIGVTALRM",/* 26       virtual time alarm */
"SIGPROF", /*  27       profiling time alarm */
"SIGWINCH",/*  28       window size changes */
"SIGINFO", /*  29       information request */
"SIGUSR1", /*  30       user defined signal 1 */
"SIGUSR2", /*  31       user defined signal 2 */
};

/*
 *      routine to process a fatal error signal
 */
static void
sigpanic(int sig)
{
        char buf[128];
        signal(sig, SIG_DFL);
        sprintf(buf, "\nLarn - Panic! Signal %d received [%s]", sig, signame[sig]);
        write(2, buf, strlen(buf));
        sleep(2);
        sncbr();
        savegame(savefilename);
        kill(getpid(), sig);    /* this will terminate us */
}