Exemplo n.º 1
0
void
prim_debug_line(PRIM_PROTOTYPE)
{
    if (((FLAGS(program) & DARK) == 0) && controls(player, program)) {
	char *msg = debug_inst(fr, 0, pc, fr->pid, arg, buf, sizeof(buf), *top, program);
	notify_nolisten(player, msg, 1);
    }
}
Exemplo n.º 2
0
struct inst *
interp_loop(dbref player, dbref program, struct frame *fr, int rettyp)
{
	register struct inst *pc;
	register int atop;
	register struct inst *arg;
	register struct inst *temp1;
	register struct inst *temp2;
	register struct stack_addr *sys;
	register int instr_count;
	register int stop;
	int i = 0, tmp, writeonly, mlev;
	static struct inst retval;
	char dbuf[BUFFER_LEN];
	int instno_debug_line = get_primitive("debug_line");


	fr->level = ++interp_depth;	/* increment interp level */

	/* load everything into local stuff */
	pc = fr->pc;
	atop = fr->argument.top;
	stop = fr->system.top;
	arg = fr->argument.st;
	sys = fr->system.st;
	writeonly = fr->writeonly;
	already_created = 0;
	fr->brkpt.isread = 0;

	if (!pc) {
		struct line *tmpline;

		tmpline = PROGRAM_FIRST(program);
		PROGRAM_SET_FIRST(program, (struct line *) read_program(program));
		do_compile(-1, OWNER(program), program, 0);
		free_prog_text(PROGRAM_FIRST(program));
		PROGRAM_SET_FIRST(program, tmpline);
		pc = fr->pc = PROGRAM_START(program);
		if (!pc) {
			abort_loop_hard("Program not compilable. Cannot run.", NULL, NULL);
		}
		PROGRAM_INC_PROF_USES(program);
		PROGRAM_INC_INSTANCES(program);
	}
	ts_useobject(program);
	err = 0;

	instr_count = 0;
	mlev = ProgMLevel(program);
	gettimeofday(&fr->proftime, NULL);

	/* This is the 'natural' way to exit a function */
	while (stop) {

		/* Abort program if player/thing running it is recycled */
		if ((player < 0) || (player >= db_top) || ((Typeof(player) != TYPE_PLAYER) && (Typeof(player) != TYPE_THING)))
		{
			reload(fr, atop, stop);
			prog_clean(fr);
			interp_depth--;
			calc_profile_timing(program,fr);

			return NULL;
		}

		fr->instcnt++;
		instr_count++;

		if ((fr->multitask == PREEMPT) || (FLAGS(program) & BUILDER)) {
			if (mlev == 4) {
				if (tp_max_ml4_preempt_count)
				{
					if (instr_count >= tp_max_ml4_preempt_count)
						abort_loop_hard("Maximum preempt instruction count exceeded", NULL, NULL);
				}
				else
					instr_count = 0;
			} else {
				/* else make sure that the program doesn't run too long */
				if (instr_count >= tp_max_instr_count)
					abort_loop_hard("Maximum preempt instruction count exceeded", NULL, NULL);
			}
		} else {
			/* if in FOREGROUND or BACKGROUND mode, '0 sleep' every so often. */
			if ((fr->instcnt > tp_instr_slice * 4) && (instr_count >= tp_instr_slice)) {
				fr->pc = pc;
				reload(fr, atop, stop);
				PLAYER_SET_BLOCK(player, (!fr->been_background));
				add_muf_delay_event(0, fr->descr, player, NOTHING, NOTHING, program, fr,
									(fr->multitask ==
									 FOREGROUND) ? "FOREGROUND" : "BACKGROUND");
				interp_depth--;
				calc_profile_timing(program,fr);
				return NULL;
			}
		}
		if (((FLAGS(program) & ZOMBIE) || fr->brkpt.force_debugging) &&
				!fr->been_background &&
				controls(player, program)
		) {
			fr->brkpt.debugging = 1;
		} else {
			fr->brkpt.debugging = 0;
		}
		if (FLAGS(program) & DARK ||
			(fr->brkpt.debugging && fr->brkpt.showstack && !fr->brkpt.bypass)) {

			if ((pc->type != PROG_PRIMITIVE) || (pc->data.number != instno_debug_line))
			{
				char *m = debug_inst(fr, 0, pc, fr->pid, arg, dbuf, sizeof(dbuf), atop, program);

				notify_nolisten(player, m, 1);
			}
		}
		if (fr->brkpt.debugging) {
			short breakflag = 0;
			if (stop == 1 &&
					!fr->brkpt.bypass &&
					pc->type == PROG_PRIMITIVE &&
					pc->data.number == IN_RET
			) {
				/* Program is about to EXIT */
				notify_nolisten(player, "Program is about to EXIT.", 1);
				breakflag = 1;
			} else if (fr->brkpt.count) {
				for (i = 0; i < fr->brkpt.count; i++) {
					if ((!fr->brkpt.pc[i] || pc == fr->brkpt.pc[i]) &&
						/* pc matches */
						(fr->brkpt.line[i] == -1 ||
						 (fr->brkpt.lastline != pc->line &&
						  fr->brkpt.line[i] == pc->line)) &&
						/* line matches */
						(fr->brkpt.level[i] == -1 ||
						 stop <= fr->brkpt.level[i]) &&
						/* level matches */
						(fr->brkpt.prog[i] == NOTHING ||
						 fr->brkpt.prog[i] == program) &&
						/* program matches */
						(fr->brkpt.linecount[i] == -2 ||
						 (fr->brkpt.lastline != pc->line &&
						  fr->brkpt.linecount[i]-- <= 0)) &&
						/* line count matches */
						(fr->brkpt.pccount[i] == -2 ||
						 (fr->brkpt.lastpc != pc &&
						  fr->brkpt.pccount[i]-- <= 0))
						/* pc count matches */
					) {
						if (fr->brkpt.bypass) {
							if (fr->brkpt.pccount[i] == -1)
								fr->brkpt.pccount[i] = 0;
							if (fr->brkpt.linecount[i] == -1)
								fr->brkpt.linecount[i] = 0;
						} else {
							breakflag = 1;
							break;
						}
					}
				}
			}
			if (breakflag) {
				char *m;
				char buf[BUFFER_LEN];

				if (fr->brkpt.dosyspop) {
					program = sys[--stop].progref;
					pc = sys[stop].offset;
				}
				add_muf_read_event(fr->descr, player, program, fr);
				reload(fr, atop, stop);
				fr->pc = pc;
				fr->brkpt.isread = 0;
				fr->brkpt.breaknum = i;
				fr->brkpt.lastlisted = 0;
				fr->brkpt.bypass = 0;
				fr->brkpt.dosyspop = 0;
				PLAYER_SET_CURR_PROG(player, program);
				PLAYER_SET_BLOCK(player, 0);
				interp_depth--;
				if (!fr->brkpt.showstack) {
					m = debug_inst(fr, 0, pc, fr->pid, arg, dbuf, sizeof(dbuf), atop, program);
					notify_nolisten(player, m, 1);
				}
				if (pc <= PROGRAM_CODE(program) || (pc - 1)->line != pc->line) {
					list_proglines(player, program, fr, pc->line, 0);
				} else {
					m = show_line_prims(fr, program, pc, 15, 1);
					snprintf(buf, sizeof(buf), "     %s", m);
					notify_nolisten(player, buf, 1);
				}
				calc_profile_timing(program,fr);
				return NULL;
			}
			fr->brkpt.lastline = pc->line;
			fr->brkpt.lastpc = pc;
			fr->brkpt.bypass = 0;
		}
		if (mlev < 3) {
			if (fr->instcnt > (tp_max_instr_count * ((mlev == 2) ? 4 : 1)))
				abort_loop_hard("Maximum total instruction count exceeded.", NULL, NULL);
		}
		switch (pc->type) {
		case PROG_INTEGER:
		case PROG_FLOAT:
		case PROG_ADD:
		case PROG_OBJECT:
		case PROG_VAR:
		case PROG_LVAR:
		case PROG_SVAR:
		case PROG_STRING:
		case PROG_LOCK:
		case PROG_MARK:
		case PROG_ARRAY:
			if (atop >= STACK_SIZE)
				abort_loop("Stack overflow.", NULL, NULL);
			copyinst(pc, arg + atop);
			pc++;
			atop++;
			break;

		case PROG_LVAR_AT:
		case PROG_LVAR_AT_CLEAR:
			{
				struct inst *tmp;
				struct localvars *lv;

				if (atop >= STACK_SIZE)
					abort_loop("Stack overflow.", NULL, NULL);

				if (pc->data.number >= MAX_VAR || pc->data.number < 0)
					abort_loop("Scoped variable number out of range.", NULL, NULL);

				lv = localvars_get(fr, program);
				tmp = &(lv->lvars[pc->data.number]);

				copyinst(tmp, arg + atop);

				if (pc->type == PROG_LVAR_AT_CLEAR) {
					CLEAR(tmp);
					tmp->type			= PROG_INTEGER;
					tmp->data.number	= 0;
				}

				pc++;
				atop++;
			}
			break;

		case PROG_LVAR_BANG:
			{
				struct inst *the_var;
				struct localvars *lv;
				if (atop < 1)
					abort_loop("Stack Underflow.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);

				if (pc->data.number >= MAX_VAR || pc->data.number < 0)
					abort_loop("Scoped variable number out of range.", NULL, NULL);

				lv = localvars_get(fr, program);
				the_var = &(lv->lvars[pc->data.number]);

				CLEAR(the_var);
				temp1 = arg + --atop;
				*the_var = *temp1;
				pc++;
			}
			break;

		case PROG_SVAR_AT:
		case PROG_SVAR_AT_CLEAR:
			{
				struct inst *tmp;

				if (atop >= STACK_SIZE)
					abort_loop("Stack overflow.", NULL, NULL);

				tmp = scopedvar_get(fr, 0, pc->data.number);
				if (!tmp)
					abort_loop("Scoped variable number out of range.", NULL, NULL);

				copyinst(tmp, arg + atop);

				if (pc->type == PROG_SVAR_AT_CLEAR) {
					CLEAR(tmp);

					tmp->type			= PROG_INTEGER;
					tmp->data.number	= 0;
				}

				pc++;
				atop++;
			}
			break;

		case PROG_SVAR_BANG:
			{
				struct inst *the_var;
				if (atop < 1)
					abort_loop("Stack Underflow.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);

				the_var = scopedvar_get(fr, 0, pc->data.number);
				if (!the_var)
					abort_loop("Scoped variable number out of range.", NULL, NULL);

				CLEAR(the_var);
				temp1 = arg + --atop;
				*the_var = *temp1;
				pc++;
			}
			break;

		case PROG_FUNCTION:
			{
				int i = pc->data.mufproc->args;
				if (atop < i)
					abort_loop("Stack Underflow.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < i)
					abort_loop("Stack protection fault.", NULL, NULL);
				if (fr->skip_declare)
					fr->skip_declare = 0;
				else
					scopedvar_addlevel(fr, pc, pc->data.mufproc->vars);
				while (i-->0)
				{
					struct inst *tmp;
					temp1 = arg + --atop;
					tmp = scopedvar_get(fr, 0, i);
					if (!tmp)
						abort_loop_hard("Internal error: Scoped variable number out of range in FUNCTION init.", temp1, NULL);
					CLEAR(tmp);
					copyinst(temp1, tmp);
					CLEAR(temp1);
				}
				pc++;
			}
			break;

		case PROG_IF:
			if (atop < 1)
				abort_loop("Stack Underflow.", NULL, NULL);
			if (fr->trys.top && atop - fr->trys.st->depth < 1)
				abort_loop("Stack protection fault.", NULL, NULL);
			temp1 = arg + --atop;
			if (false_inst(temp1))
				pc = pc->data.call;
			else
				pc++;
			CLEAR(temp1);
			break;

		case PROG_EXEC:
			if (stop >= STACK_SIZE)
				abort_loop("System Stack Overflow", NULL, NULL);
			sys[stop].progref = program;
			sys[stop++].offset = pc + 1;
			pc = pc->data.call;
			fr->skip_declare = 0;  /* Make sure we DON'T skip var decls */
			break;

		case PROG_JMP:
			/* Don't need to worry about skipping scoped var decls here. */
			/* JMP to a function header can only happen in IN_JMP */
			pc = pc->data.call;
			break;

		case PROG_TRY:
			if (atop < 1)
				abort_loop("Stack Underflow.", NULL, NULL);
			if (fr->trys.top && atop - fr->trys.st->depth < 1)
				abort_loop("Stack protection fault.", NULL, NULL);
			temp1 = arg + --atop;
			if (temp1->type != PROG_INTEGER || temp1->data.number < 0)
				abort_loop("Argument is not a positive integer.", temp1, NULL);
			if (fr->trys.top && atop - fr->trys.st->depth < temp1->data.number)
				abort_loop("Stack protection fault.", NULL, NULL);
			if (temp1->data.number > atop)
				abort_loop("Stack Underflow.", temp1, NULL);

			fr->trys.top++;
			fr->trys.st = push_try(fr->trys.st);
			fr->trys.st->depth = atop - temp1->data.number;
			fr->trys.st->call_level = stop;
			fr->trys.st->for_count = 0;
			fr->trys.st->addr = pc->data.call;

			pc++;
			CLEAR(temp1);
			break;

		case PROG_PRIMITIVE:
			/*
			 * All pc modifiers and stuff like that should stay here,
			 * everything else call with an independent dispatcher.
			 */
			switch (pc->data.number) {
			case IN_JMP:
				if (atop < 1)
					abort_loop("Stack underflow.  Missing address.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);
				temp1 = arg + --atop;
				if (temp1->type != PROG_ADD)
					abort_loop("Argument is not an address.", temp1, NULL);
				if (temp1->data.addr->progref >= db_top ||
					temp1->data.addr->progref < 0 ||
					(Typeof(temp1->data.addr->progref) != TYPE_PROGRAM))
							abort_loop_hard("Internal error.  Invalid address.", temp1, NULL);
				if (program != temp1->data.addr->progref) {
					abort_loop("Destination outside current program.", temp1, NULL);
				}
				if (temp1->data.addr->data->type == PROG_FUNCTION) {
					fr->skip_declare = 1;
				}
				pc = temp1->data.addr->data;
				CLEAR(temp1);
				break;

			case IN_EXECUTE:
				if (atop < 1)
					abort_loop("Stack Underflow. Missing address.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);
				temp1 = arg + --atop;
				if (temp1->type != PROG_ADD)
					abort_loop("Argument is not an address.", temp1, NULL);
				if (temp1->data.addr->progref >= db_top ||
					temp1->data.addr->progref < 0 ||
					(Typeof(temp1->data.addr->progref) != TYPE_PROGRAM))
							abort_loop_hard("Internal error.  Invalid address.", temp1, NULL);
				if (stop >= STACK_SIZE)
					abort_loop("System Stack Overflow", temp1, NULL);
				sys[stop].progref = program;
				sys[stop++].offset = pc + 1;
				if (program != temp1->data.addr->progref) {
					program = temp1->data.addr->progref;
					fr->caller.st[++fr->caller.top] = program;
					mlev = ProgMLevel(program);
					PROGRAM_INC_INSTANCES(program);
				}
				pc = temp1->data.addr->data;
				CLEAR(temp1);
				break;

			case IN_CALL:
				if (atop < 1)
					abort_loop("Stack Underflow. Missing dbref argument.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);
				temp1 = arg + --atop;
				temp2 = 0;
				if (temp1->type != PROG_OBJECT) {
					temp2 = temp1;
					if (atop < 1)
						abort_loop("Stack Underflow. Missing dbref of func.", temp1, NULL);
					if (fr->trys.top && atop - fr->trys.st->depth < 1)
						abort_loop("Stack protection fault.", NULL, NULL);
					temp1 = arg + --atop;
					if (temp2->type != PROG_STRING)
						abort_loop("Public Func. name string required. (2)", temp1, temp2);
					if (!temp2->data.string)
						abort_loop("Null string not allowed. (2)", temp1, temp2);
				}
				if (temp1->type != PROG_OBJECT)
					abort_loop("Dbref required. (1)", temp1, temp2);
				if (!valid_object(temp1)
					|| Typeof(temp1->data.objref) != TYPE_PROGRAM)
					abort_loop("Invalid object.", temp1, temp2);
				if (!(PROGRAM_CODE(temp1->data.objref))) {
					struct line *tmpline;

					tmpline = PROGRAM_FIRST(temp1->data.objref);
					PROGRAM_SET_FIRST(temp1->data.objref,
									  (struct line *) read_program(temp1->data.objref));
					do_compile(-1, OWNER(temp1->data.objref), temp1->data.objref, 0);
					free_prog_text(PROGRAM_FIRST(temp1->data.objref));
					PROGRAM_SET_FIRST(temp1->data.objref, tmpline);
					if (!(PROGRAM_CODE(temp1->data.objref)))
						abort_loop("Program not compilable.", temp1, temp2);
				}
				if (ProgMLevel(temp1->data.objref) == 0)
					abort_loop("Permission denied", temp1, temp2);
				if (mlev < 4 && OWNER(temp1->data.objref) != ProgUID
					&& !Linkable(temp1->data.objref))
							abort_loop("Permission denied", temp1, temp2);
				if (stop >= STACK_SIZE)
					abort_loop("System Stack Overflow", temp1, temp2);
				sys[stop].progref = program;
				sys[stop].offset = pc + 1;
				if (!temp2) {
					pc = PROGRAM_START(temp1->data.objref);
				} else {
					struct publics *pbs;
					int tmpint;

					pbs = PROGRAM_PUBS(temp1->data.objref);
					while (pbs) {
						tmpint = string_compare(temp2->data.string->data, pbs->subname);
						if (!tmpint)
							break;
						pbs = pbs->next;
					}
					if (!pbs)
						abort_loop("PUBLIC or WIZCALL function not found. (2)", temp2, temp2);
					if (mlev < pbs->mlev)
						abort_loop("Insufficient permissions to call WIZCALL function. (2)",
								   temp2, temp2);
					pc = pbs->addr.ptr;
				}
				stop++;
				if (temp1->data.objref != program) {
					calc_profile_timing(program,fr);
					gettimeofday(&fr->proftime, NULL);
					program = temp1->data.objref;
					fr->caller.st[++fr->caller.top] = program;
					PROGRAM_INC_INSTANCES(program);
					mlev = ProgMLevel(program);
				}
				PROGRAM_INC_PROF_USES(program);
				ts_useobject(program);
				CLEAR(temp1);
				if (temp2)
					CLEAR(temp2);
				break;

			case IN_RET:
				if (stop > 1 && program != sys[stop - 1].progref) {
					if (sys[stop - 1].progref >= db_top ||
						sys[stop - 1].progref < 0 ||
						(Typeof(sys[stop - 1].progref) != TYPE_PROGRAM))
								abort_loop_hard("Internal error.  Invalid address.", NULL, NULL);
					calc_profile_timing(program,fr);
					gettimeofday(&fr->proftime, NULL);
					PROGRAM_DEC_INSTANCES(program);
					program = sys[stop - 1].progref;
					mlev = ProgMLevel(program);
					fr->caller.top--;
				}
				scopedvar_poplevel(fr);
				pc = sys[--stop].offset;
				break;

			case IN_CATCH:
			case IN_CATCH_DETAILED:
				{
					int depth;

					if (!(fr->trys.top))
						abort_loop_hard("Internal error.  TRY stack underflow.", NULL, NULL);

					depth = fr->trys.st->depth;
					while (atop > depth) {
						temp1 = arg + --atop;
						CLEAR(temp1);
					}

					while (fr->trys.st->for_count-->0) {
						CLEAR(&fr->fors.st->cur);
						CLEAR(&fr->fors.st->end);
						fr->fors.top--;
						fr->fors.st = pop_for(fr->fors.st);
					}

					fr->trys.top--;
					fr->trys.st = pop_try(fr->trys.st);

					if (pc->data.number == IN_CATCH) {
						/* IN_CATCH */
						if (fr->errorstr) {
							arg[atop].type = PROG_STRING;
							arg[atop++].data.string = alloc_prog_string(fr->errorstr);
							free(fr->errorstr);
							fr->errorstr = NULL;
						} else {
							arg[atop].type = PROG_STRING;
							arg[atop++].data.string = NULL;
						}
						if (fr->errorinst) {
							free(fr->errorinst);
							fr->errorinst = NULL;
						}
					} else {
						/* IN_CATCH_DETAILED */
						stk_array *nu = new_array_dictionary();
						if (fr->errorstr) {
							array_set_strkey_strval(&nu, "error", fr->errorstr);
							free(fr->errorstr);
							fr->errorstr = NULL;
						}
						if (fr->errorinst) {
							array_set_strkey_strval(&nu, "instr", fr->errorinst);
							free(fr->errorinst);
							fr->errorinst = NULL;
						}
						array_set_strkey_intval(&nu, "line", fr->errorline);
						array_set_strkey_refval(&nu, "program", fr->errorprog);
						arg[atop].type = PROG_ARRAY;
						arg[atop++].data.array = nu;
					}
					reload(fr, atop, stop);
				}
				pc++;
				break;

			case IN_EVENT_WAITFOR:
				if (atop < 1)
					abort_loop("Stack Underflow. Missing eventID list array argument.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);
				temp1 = arg + --atop;
				if (temp1->type != PROG_ARRAY)
					abort_loop("EventID string list array expected.", temp1, NULL);
				if (temp1->data.array && temp1->data.array->type != ARRAY_PACKED)
					abort_loop("Argument must be a list array of eventid strings.", temp1, NULL);
				if (!array_is_homogenous(temp1->data.array, PROG_STRING))
					abort_loop("Argument must be a list array of eventid strings.", temp1, NULL);
				fr->pc = pc + 1;
				reload(fr, atop, stop);

				{
					int i, outcount;
					int count = array_count(temp1->data.array);
					char** events = (char**)malloc(count * sizeof(char**));
					for (outcount = i = 0; i < count; i++) {
						char *val = array_get_intkey_strval(temp1->data.array, i);
						if (val != NULL) {
							int found = 0;
							int j;
							for (j = 0; j < outcount; j++) {
								if (!strcmp(events[j], val)) {
									found = 1;
									break;
								}
							}
							if (!found) {
								events[outcount++] = val;
							}
						}
					}
					muf_event_register_specific(player, program, fr, outcount, events);
					free(events);
				}

				PLAYER_SET_BLOCK(player, (!fr->been_background));
				CLEAR(temp1);
				interp_depth--;
				calc_profile_timing(program,fr);
				return NULL;
				/* NOTREACHED */
				break;

			case IN_READ:
				if (writeonly)
					abort_loop("Program is write-only.", NULL, NULL);
				if (fr->multitask == BACKGROUND)
					abort_loop("BACKGROUND programs are write only.", NULL, NULL);
				reload(fr, atop, stop);
				fr->brkpt.isread = 1;
				fr->pc = pc + 1;
				PLAYER_SET_CURR_PROG(player, program);
				PLAYER_SET_BLOCK(player, 0);
				add_muf_read_event(fr->descr, player, program, fr);
				interp_depth--;
				calc_profile_timing(program,fr);
				return NULL;
				/* NOTREACHED */
				break;

			case IN_SLEEP:
				if (atop < 1)
					abort_loop("Stack Underflow.", NULL, NULL);
				if (fr->trys.top && atop - fr->trys.st->depth < 1)
					abort_loop("Stack protection fault.", NULL, NULL);
				temp1 = arg + --atop;
				if (temp1->type != PROG_INTEGER)
					abort_loop("Invalid argument type.", temp1, NULL);
				fr->pc = pc + 1;
				reload(fr, atop, stop);
				if (temp1->data.number < 0)
					abort_loop("Timetravel beyond scope of muf.", temp1, NULL);
				add_muf_delay_event(temp1->data.number, fr->descr, player,
									NOTHING, NOTHING, program, fr, "SLEEPING");
				PLAYER_SET_BLOCK(player, (!fr->been_background));
				interp_depth--;
				calc_profile_timing(program,fr);
				return NULL;
				/* NOTREACHED */
				break;

			default:
				nargs = 0;
				reload(fr, atop, stop);
				tmp = atop;
				prim_func[pc->data.number - 1] (player, program, mlev, pc, arg, &tmp, fr);
				atop = tmp;
				pc++;
				break;
			}					/* switch */
			break;
		case PROG_CLEARED:
			log_status("WARNING: attempt to execute instruction cleared by %s:%hd in program %d",
					   (char*)pc->data.addr, pc->line, program);
			pc = NULL;
			abort_loop_hard("Program internal error. Program erroneously freed from memory.",
							NULL, NULL);
		default:
			pc = NULL;
			abort_loop_hard("Program internal error. Unknown instruction type.",
							NULL, NULL);
		}						/* switch */
		if (err) {
			if (err != ERROR_DIE_NOW && fr->trys.top) {
				while (fr->trys.st->call_level < stop) {
					if (stop > 1 && program != sys[stop - 1].progref) {
						if (sys[stop - 1].progref >= db_top ||
							sys[stop - 1].progref < 0 ||
							(Typeof(sys[stop - 1].progref) != TYPE_PROGRAM))
									abort_loop_hard("Internal error.  Invalid address.", NULL, NULL);
						calc_profile_timing(program,fr);
						gettimeofday(&fr->proftime, NULL);
						PROGRAM_DEC_INSTANCES(program);
						program = sys[stop - 1].progref;
						mlev = ProgMLevel(program);
						fr->caller.top--;
					}
					scopedvar_poplevel(fr);
					stop--;
				}

				pc = fr->trys.st->addr;
				err = 0;
			} else {
				reload(fr, atop, stop);
				prog_clean(fr);
				PLAYER_SET_BLOCK(player, 0);
				interp_depth--;
				calc_profile_timing(program,fr);
				return NULL;
			}
		}
	}							/* while */

	PLAYER_SET_BLOCK(player, 0);
	if (atop) {
		struct inst *rv;

		if (rettyp) {
			copyinst(arg + atop - 1, &retval);
			rv = &retval;
		} else {
			if (!false_inst(arg + atop - 1)) {
				rv = (struct inst *) 1;
			} else {
				rv = NULL;
			}
		}
		reload(fr, atop, stop);
		prog_clean(fr);
		interp_depth--;
		calc_profile_timing(program,fr);
		return rv;
	}
	reload(fr, atop, stop);
	prog_clean(fr);
	interp_depth--;
	calc_profile_timing(program,fr);
	return NULL;
}