/** @file
 *  Trap handling and management routines.
 */

/* $Id$ */

#include	<setjmp.h>

#include	<em_abs.h>
#include	"logging.h"
#include	"global.h"
#include	"log.h"
#include	"trap.h"
#include	"io.h"
#include	"warn.h"
#include	"mem.h"
#include	"shadow.h"
#include	"linfil.h"
#include	"rsb.h"
#include	"fra.h"
#include	"whatever.h"

extern jmp_buf trapbuf; /* from main.c */

int must_test; /* TEST-bit on in EM header word 2 */
int signalled;

PRIVATE int nonreturnable();

PRIVATE char *trap_msg[] =
{
#include	"trap_msg"		/* generated from $(EM)/etc/traps */
		"" };

char *trap2text(int nr)
{
	if ( /* trap number in predefined range */
	nr < sizeof(trap_msg) / sizeof(trap_msg[0]) && /* trap message not the empty string */
	trap_msg[nr][0])
	{
		return trap_msg[nr];
	}
	else
	{
		static char buf[50];

		sprintf(buf, "TRAP %d", nr);
		return buf;
	}
}

/*ARGSUSED*/
void do_trap(int nr, int L, char *F)
{
	/*
	 1.	The trap has not been masked.
	 2.	This routine does not return; it either ends in a call of
	 fatal() or in a longjmp().
	 */
	static int rec_nr; /* Recursive trap number */
	static int rec_trap = 0; /* To detect traps inside do_trap() */

	register long tpi; /* Trap Procedure Identifier */

	LOG(("@t1 trap(%d) [%s: %d]", nr, F, L));
	warning(WMSG + nr);

	switch (OnTrap)
	{
	case TR_ABORT:
		fatal("trap \"%s\" before program started", trap2text(nr));
		/*NOTREACHED*/

	case TR_HALT:
		fatal("trap \"%s\" not caught at %s", trap2text(nr), position());
		/*NOTREACHED*/

	case TR_TRAP:
		/* execute the trap */
		if (rec_trap)
		{
			fatal("recursive trap; first trap number was \"%s\"",
					trap2text(rec_nr));
		}
		rec_trap = 1;
		rec_nr = nr;

		/* save the Function Return Area */
		pushFRA(FRASize);
		wpush((long) FRASize);
		wpush((long) FRA_def);

		/* set up the trap number as the only parameter */
		wpush((long) nr);

		tpi = TrapPI; /* allowed since OnTrap == TR_TRAP */
		TrapPI = 0;
		OnTrap = TR_HALT;
		call(tpi, (nonreturnable(nr) ? RSB_NRT : RSB_RTT));
		rec_trap = 0;
		longjmp(trapbuf, 1);
		/*NOTREACHED*/
	}
}

PRIVATE int nonreturnable(int nr)
{
	switch (nr)
	{
	case ESTACK:
	case EILLINS:
	case EODDZ:
	case ECASE:
	case EMEMFLT:
	case EBADPTR:
	case EBADPC:
	case EBADLAE:
	case EBADGTO:
		return 1;
	default:
		return 0;
	}
	/*NOTREACHED*/
}