コード例 #1
0
ファイル: p_misc.c プロジェクト: foxbird/fuzzball
void
prim_force(PRIM_PROTOTYPE)
{
    struct inst *oper1 = NULL;	/* prevents re-entrancy issues! */
    struct inst *oper2 = NULL;	/* prevents re-entrancy issues! */

    /* d s -- */
    CHECKOP(2);
    oper1 = POP();		/* string to @force */
    oper2 = POP();		/* player dbref */
    if (mlev < 4)
	abort_interp("Wizbit only primitive.");
    if (fr->level > 8)
	abort_interp("Interp call loops not allowed.");
    if (oper1->type != PROG_STRING)
	abort_interp("Non-string argument (2).");
    if (oper2->type != PROG_OBJECT)
	abort_interp("Non-object argument (1).");
    ref = oper2->data.objref;
    if (!ObjExists(ref))
	abort_interp("Invalid object to force. (1)");
    if (Typeof(ref) != TYPE_PLAYER && Typeof(ref) != TYPE_THING)
	abort_interp("Object to force not a thing or player. (1)");
    if (0 == strcmp(DoNullInd(oper1->data.string), ""))
	abort_interp("Empty command argument (2).");
    if (index(oper1->data.string->data, '\r'))
	abort_interp("Carriage returns not allowed in command string. (2).");
#ifdef GOD_PRIV
    if (God(oper2->data.objref) && !God(OWNER(program)))
	abort_interp("Cannot force god (1).");
#endif
    objnode_push(&forcelist, player);
    objnode_push(&forcelist, program);
    force_level++;
    process_command(dbref_first_descr(oper2->data.objref), oper2->data.objref,
		    oper1->data.string->data);
    force_level--;
    objnode_pop(&forcelist);
    objnode_pop(&forcelist);

    for (int i = 1; i <= fr->caller.top; i++) {
	if (Typeof(fr->caller.st[i]) != TYPE_PROGRAM) {
#ifdef DEBUG
	    notifyf_nolisten(player, "[debug] prim_force: fr->caller.st[%d] isn't a program.", i);
#endif				/* DEBUG */
	    do_abort_silent();
	}
    }

    CLEAR(oper1);
    CLEAR(oper2);
}
コード例 #2
0
ファイル: interp.c プロジェクト: revarbat/fuzzball
void
interp_err(dbref player, dbref program, struct inst *pc,
		   struct inst *arg, int atop, dbref origprog, const char *msg1, const char *msg2)
{
	char buf[BUFFER_LEN];
	char buf2[BUFFER_LEN];
	char tbuf[40];
	int errcount;
	time_t lt;

	err++;

	if (OWNER(origprog) == OWNER(player)) {
		strcpyn(buf, sizeof(buf), "\033[1;31;40mProgram Error.  Your program just got the following error.\033[0m");
	} else {
		snprintf(buf, sizeof(buf), "\033[1;31;40mProgrammer Error.  Please tell %s what you typed, and the following message.\033[0m",
				NAME(OWNER(origprog)));
	}
	notify_nolisten(player, buf, 1);

	notifyf_nolisten(player, "\033[1m%s(#%d), line %d; %s: %s\033[0m",
			 NAME(program), program, pc ? pc->line : -1, msg1, msg2);

	lt = time(NULL);
	format_time(tbuf, 32, "%c", MUCK_LOCALTIME(lt));

	strip_ansi(buf2, buf);
	errcount = get_property_value(origprog, ".debug/errcount");
	errcount++;
	add_property(origprog, ".debug/errcount", NULL, errcount);
	add_property(origprog, ".debug/lasterr", buf2, 0);
	add_property(origprog, ".debug/lastcrash", NULL, (int)lt);
	add_property(origprog, ".debug/lastcrashtime", tbuf, 0);

	if (origprog != program) {
		errcount = get_property_value(program, ".debug/errcount");
		errcount++;
		add_property(program, ".debug/errcount", NULL, errcount);
		add_property(program, ".debug/lasterr", buf2, 0);
		add_property(program, ".debug/lastcrash", NULL, (int)lt);
		add_property(program, ".debug/lastcrashtime", tbuf, 0);
	}
}
コード例 #3
0
ファイル: interp.c プロジェクト: revarbat/fuzzball
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;

				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);
					notifyf_nolisten(player, "     %s", m);
				}
				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;
}
コード例 #4
0
ファイル: debugger.c プロジェクト: fuzzball-muck/fuzzball
/**
 * Implementation of the MUF debugger
 *
 * This implements the command parsing for the MUF debugger.  It also clears
 * temporary bookmarks if this was triggered from a temporary one.
 *
 * This relies on some static globals, so it is not threadsafe.  If the
 * 'prim' debugger command is ever used to trigger the MUF debugger somehow
 * in a recursive fashion, and then you call 'prim' again, it will probably
 * cause havock.
 *
 * @param descr the descriptor of the debugging player
 * @param player the debugging player
 * @param program the program we are debugging
 * @param text the input text from the user
 * @param fr the current frame pointer
 * @return boolean true if the program should exit, false if not
 */
int
muf_debugger(int descr, dbref player, dbref program, const char *text, struct frame *fr)
{
    char cmd[BUFFER_LEN];
    char buf[BUFFER_LEN];
    char buf2[BUFFER_LEN];
    char *ptr, *ptr2, *arg;
    struct inst *pinst;
    int i, j, cnt;
    static struct inst primset[5];
    static struct muf_proc_data temp_muf_proc_data = {
        "__Temp_Debugger_Proc",
        0,
        0,
        NULL
    };

    /*
     * Basic massaging of the input - clearing spaces, finding the
     * argument.
     */
    skip_whitespace(&text);
    strcpyn(cmd, sizeof(cmd), text);

    ptr = cmd;
    remove_ending_whitespace(&ptr);

    for (arg = cmd; *arg && !isspace(*arg); arg++) ;

    if (*arg)
        *arg++ = '\0';

    /* Empty command means repeat last command, if available */
    if (!*cmd && fr->brkpt.lastcmd) {
        strcpyn(cmd, sizeof(cmd), fr->brkpt.lastcmd);
    } else {
        free(fr->brkpt.lastcmd);

        if (*cmd)
            fr->brkpt.lastcmd = strdup(cmd);
    }

    /* delete triggering breakpoint, if it's only temp. */
    j = fr->brkpt.breaknum;

    if (j >= 0 && fr->brkpt.temp[j]) {
        for (j++; j < fr->brkpt.count; j++) {
            fr->brkpt.temp[j - 1] = fr->brkpt.temp[j];
            fr->brkpt.level[j - 1] = fr->brkpt.level[j];
            fr->brkpt.line[j - 1] = fr->brkpt.line[j];
            fr->brkpt.linecount[j - 1] = fr->brkpt.linecount[j];
            fr->brkpt.pc[j - 1] = fr->brkpt.pc[j];
            fr->brkpt.pccount[j - 1] = fr->brkpt.pccount[j];
            fr->brkpt.prog[j - 1] = fr->brkpt.prog[j];
        }

        fr->brkpt.count--;
    }

    fr->brkpt.breaknum = -1;

    /**
     * @TODO This giant if statement is pretty gnarly; we'd be better
     *       of looping over an array of callbacks to break this up
     *       nicer and make it more extensible.
     */

    if (!strcasecmp(cmd, "cont")) {
        /* Nothing to do -- this will continue to next breakpoint */
    } else if (!strcasecmp(cmd, "finish")) {
        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player,
                            "Cannot finish because there are too many breakpoints set.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = fr->system.top - 1;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = program;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "stepi")) {
        i = atoi(arg);

        if (!i)
            i = 1;

        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player, "Cannot stepi because there are too many breakpoints set.",
                            1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = -1;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = i;
        fr->brkpt.prog[j] = NOTHING;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "step")) {
        i = atoi(arg);

        if (!i)
            i = 1;

        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player, "Cannot step because there are too many breakpoints set.",
                            1);

            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = -1;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = i;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = NOTHING;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "nexti")) {
        i = atoi(arg);

        if (!i)
            i = 1;

        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player, "Cannot nexti because there are too many breakpoints set.",
                            1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = fr->system.top;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = i;
        fr->brkpt.prog[j] = program;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "next")) {
        i = atoi(arg);

        if (!i)
            i = 1;

        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player, "Cannot next because there are too many breakpoints set.",
                            1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = fr->system.top;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = i;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = program;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "exec")) {
        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player,
                            "Cannot finish because there are too many breakpoints set.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        if (!(pinst = funcname_to_pc(program, arg))) {
            notify_nolisten(player, "I don't know a function by that name.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        if (fr->system.top >= STACK_SIZE) {
            notify_nolisten(player,
                            "That would exceed the system stack size for this program.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        fr->system.st[fr->system.top].progref = program;
        fr->system.st[fr->system.top++].offset = fr->pc;
        fr->pc = pinst;
        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = fr->system.top - 1;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = program;
        fr->brkpt.bypass = 1;

        return 0;
    } else if (!strcasecmp(cmd, "prim")) {
        /*
         * @TODO The way this works is a little funky.  It looks like
         *       it would be possible to cause some weird havoc if we
         *       manage to run a primitive that in turn triggers muf_debugger
         *
         *       I am uncertain if this is possible; looks like the only
         *       way it could happen is by typing 'prim debugger_break'
         *       but I don't know much about about how muf_debugger is
         *       triggered.  Some digging should be done to make this
         *       safe.
         *
         *       Even better would be to not use statics for this somehow
         *       without introducing a memory leak. (tanabi)
         */
        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player,
                            "Cannot finish because there are too many breakpoints set.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        if (!primitive(arg)) {
            notify_nolisten(player, "I don't recognize that primitive.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        if (fr->system.top >= STACK_SIZE) {
            notify_nolisten(player,
                            "That would exceed the system stack size for this program.", 1);
            add_muf_read_event(descr, player, program, fr);
            return 0;
        }

        primset[0].type = PROG_FUNCTION;
        primset[0].line = 0;
        primset[0].data.mufproc = &temp_muf_proc_data;
        primset[0].data.mufproc->vars = 0;
        primset[0].data.mufproc->args = 0;
        primset[0].data.mufproc->varnames = NULL;

        primset[1].type = PROG_PRIMITIVE;
        primset[1].line = 0;
        primset[1].data.number = get_primitive(arg);

        primset[2].type = PROG_PRIMITIVE;
        primset[2].line = 0;
        primset[2].data.number = IN_RET;

        /* primset[3].data.number = primitive("EXIT"); */

        fr->system.st[fr->system.top].progref = program;
        fr->system.st[fr->system.top++].offset = fr->pc;
        fr->pc = &primset[1];
        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 1;
        fr->brkpt.level[j] = -1;
        fr->brkpt.line[j] = -1;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = &primset[2];
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = program;
        fr->brkpt.bypass = 1;
        fr->brkpt.dosyspop = 1;

        return 0;
    } else if (!strcasecmp(cmd, "break")) {
        add_muf_read_event(descr, player, program, fr);

        if (fr->brkpt.count >= MAX_BREAKS) {
            notify_nolisten(player, "Too many breakpoints set.", 1);
            return 0;
        }

        if (number(arg)) {
            i = atoi(arg);
        } else {
            if (!(pinst = funcname_to_pc(program, arg))) {
                notify_nolisten(player, "I don't know a function by that name.", 1);
                return 0;
            } else {
                i = pinst->line;
            }
        }

        if (!i)
            i = fr->pc->line;

        j = fr->brkpt.count++;
        fr->brkpt.temp[j] = 0;
        fr->brkpt.level[j] = -1;
        fr->brkpt.line[j] = i;
        fr->brkpt.linecount[j] = -2;
        fr->brkpt.pc[j] = NULL;
        fr->brkpt.pccount[j] = -2;
        fr->brkpt.prog[j] = program;
        notify_nolisten(player, "Breakpoint set.", 1);

        return 0;
    } else if (!strcasecmp(cmd, "delete")) {
        add_muf_read_event(descr, player, program, fr);
        i = atoi(arg);

        if (!i) {
            notify_nolisten(player, "Which breakpoint did you want to delete?", 1);
            return 0;
        }

        if (i < 1 || i > fr->brkpt.count) {
            notify_nolisten(player, "No such breakpoint.", 1);
            return 0;
        }

        j = i - 1;

        for (j++; j < fr->brkpt.count; j++) {
            fr->brkpt.temp[j - 1] = fr->brkpt.temp[j];
            fr->brkpt.level[j - 1] = fr->brkpt.level[j];
            fr->brkpt.line[j - 1] = fr->brkpt.line[j];
            fr->brkpt.linecount[j - 1] = fr->brkpt.linecount[j];
            fr->brkpt.pc[j - 1] = fr->brkpt.pc[j];
            fr->brkpt.pccount[j - 1] = fr->brkpt.pccount[j];
            fr->brkpt.prog[j - 1] = fr->brkpt.prog[j];
        }

        fr->brkpt.count--;
        notify_nolisten(player, "Breakpoint deleted.", 1);

        return 0;
    } else if (!strcasecmp(cmd, "breaks")) {
        notify_nolisten(player, "Breakpoints:", 1);

        for (i = 0; i < fr->brkpt.count; i++) {
            ptr = unparse_breakpoint(fr, i);
            notify_nolisten(player, ptr, 1);
        }

        notify_nolisten(player, "*done*", 1);
        add_muf_read_event(descr, player, program, fr);

        return 0;
    } else if (!strcasecmp(cmd, "where")) {
        i = atoi(arg);
        muf_backtrace(player, program, i, fr);
        add_muf_read_event(descr, player, program, fr);
        return 0;
    } else if (!strcasecmp(cmd, "stack")) {
        notify_nolisten(player, "*Argument stack top*", 1);
        i = atoi(arg);

        if (!i)
            i = STACK_SIZE;

        ptr = "";

        for (j = fr->argument.top; j > 0 && i-- > 0;) {
            cnt = 0;

            do {
                strcpyn(buf, sizeof(buf), ptr);
                ptr = insttotext(NULL, 0, &fr->argument.st[--j], buf2, sizeof(buf2), 4000,
                                 program, 1);
                cnt++;
            } while (!strcasecmp(ptr, buf) && j > 0);

            if (cnt > 1)
                notifyf(player, "     [repeats %d times]", cnt);

            if (strcasecmp(ptr, buf))
                notifyf(player, "%3d) %s", j + 1, ptr);
        }

        notify_nolisten(player, "*done*", 1);
        add_muf_read_event(descr, player, program, fr);

        return 0;
    } else if (!strcasecmp(cmd, "list") || !strcasecmp(cmd, "listi")) {
        int startline, endline;

        add_muf_read_event(descr, player, program, fr);

        if ((ptr2 = (char *) strchr(arg, ','))) {
            *ptr2++ = '\0';
        } else {
            ptr2 = "";
        }

        if (!*arg) {
            if (fr->brkpt.lastlisted) {
                startline = fr->brkpt.lastlisted + 1;
            } else {
                startline = fr->pc->line;
            }

            endline = startline + 15;
        } else {
            if (!number(arg)) {
                if (!(pinst = funcname_to_pc(program, arg))) {
                    notify_nolisten(player,
                                    "I don't know a function by that name. (starting arg, 1)",
                                    1);
                    return 0;
                } else {
                    startline = pinst->line;
                    endline = startline + 15;
                }
            } else {
                if (*ptr2) {
                    endline = startline = atoi(arg);
                } else {
                    startline = atoi(arg) - 7;
                    endline = startline + 15;
                }
            }
        }

        if (*ptr2) {
            if (!number(ptr2)) {
                if (!(pinst = funcname_to_pc(program, ptr2))) {
                    notify_nolisten(player,
                                    "I don't know a function by that name. (ending arg, 1)",
                                    1);
                    return 0;
                } else {
                    endline = pinst->line;
                }
            } else {
                endline = atoi(ptr2);
            }
        }

        i = (PROGRAM_CODE(program) + PROGRAM_SIZ(program) - 1)->line;

        if (startline > i) {
            notify_nolisten(player, "Starting line is beyond end of program.", 1);
            return 0;
        }

        if (startline < 1)
            startline = 1;

        if (endline > i)
            endline = i;

        if (endline < startline)
            endline = startline;

        notify_nolisten(player, "Listing:", 1);

        if (!strcasecmp(cmd, "listi")) {
            for (i = startline; i <= endline; i++) {
                pinst = linenum_to_pc(program, i);

                if (pinst) {
                    notifyf_nolisten(player, "line %d: %s", i, (i == fr->pc->line) ?
                                     show_line_prims(program, fr->pc, STACK_SIZE, 1) :
                                     show_line_prims(program, pinst, STACK_SIZE, 0));
                }
            }
        } else {
            list_proglines(player, program, fr, startline, endline);
        }

        fr->brkpt.lastlisted = endline;
        notify_nolisten(player, "*done*", 1);

        return 0;
    } else if (!strcasecmp(cmd, "quit")) {
        notify_nolisten(player, "Halting execution.", 1);
        return 1;
    } else if (!strcasecmp(cmd, "trace")) {
        add_muf_read_event(descr, player, program, fr);

        if (!strcasecmp(arg, "on")) {
            fr->brkpt.showstack = 1;
            notify_nolisten(player, "Trace turned on.", 1);
        } else if (!strcasecmp(arg, "off")) {
            fr->brkpt.showstack = 0;
            notify_nolisten(player, "Trace turned off.", 1);
        } else {
            notifyf_nolisten(player, "Trace is currently %s.",
                             fr->brkpt.showstack ? "on" : "off");
        }

        return 0;
    } else if (!strcasecmp(cmd, "words")) {
        list_program_functions(player, program, arg);
        add_muf_read_event(descr, player, program, fr);
        return 0;
    } else if (!strcasecmp(cmd, "print")) {
        debug_printvar(player, program, fr, arg);
        add_muf_read_event(descr, player, program, fr);
        return 0;
    } else if (!strcasecmp(cmd, "push")) {
        push_arg(player, fr, arg);
        add_muf_read_event(descr, player, program, fr);
        return 0;
    } else if (!strcasecmp(cmd, "pop")) {
        add_muf_read_event(descr, player, program, fr);

        if (fr->argument.top < 1) {
            notify_nolisten(player, "Nothing to pop.", 1);
            return 0;
        }

        fr->argument.top--;
        CLEAR(fr->argument.st + fr->argument.top);
        notify_nolisten(player, "Stack item popped.", 1);

        return 0;
    } else if (!strcasecmp(cmd, "help")) {
        do_helpfile(player, tp_file_man_dir, tp_file_man, "debugger_commands", "");

        return 0;
    } else {
        notify_nolisten(player,
                        "I don't understand that debugger command. Type 'help' for help.", 1);
        add_muf_read_event(descr, player, program, fr);
        return 0;
    }

    return 0;
}
コード例 #5
0
ファイル: debugger.c プロジェクト: fuzzball-muck/fuzzball
/**
 * Displays a MUF Backtrace message.
 *
 * This is used when a MUF program is aborted, if someone who has 'controls'
 * permissions was running it, or if you type 'where' in the debugger.
 * Shows a fairly straight forward backtrace, going 'count' deep.  If
 * 'count' is 0, it will display up to STACK_SIZE depth.
 *
 * @param player the player getting the backtrace
 * @param program the program being backtraced
 * @param count the depth of the trace, or 0 for STACK_SIZE
 * @param fr the frame pointer
 */
void
muf_backtrace(dbref player, dbref program, int count, struct frame *fr)
{
    char buf2[BUFFER_LEN];
    char buf3[BUFFER_LEN];
    char *ptr;
    dbref ref;
    int i, j, cnt, flag;
    struct inst *pinst, *lastinst;
    int lev;

    notify_nolisten(player, "\033[1;33;40mSystem stack backtrace:\033[0m", 1);
    i = count;

    if (!i)
        i = STACK_SIZE;

    ref = program;
    pinst = NULL;
    j = fr->system.top + 1;

    /*
     * i is our depth; iterate until we've run out of depth or we have
     * broken out of the loop
     */
    while (j > 1 && i-- > 0) {
        cnt = 0;

        do {
            lastinst = pinst;

            if (--j == fr->system.top) {
                pinst = fr->pc;
            } else {
                ref = fr->system.st[j].progref;
                pinst = fr->system.st[j].offset;
            }

            ptr = unparse_sysreturn(&ref, pinst);
            cnt++;
        } while (pinst == lastinst && j > 1);

        if (cnt > 1) {
            notifyf_nolisten(player, "     [repeats %d times]", cnt);
        }

        lev = fr->system.top - j;

        if (ptr) {
            int snplen;
            char *bufend = buf2;
            struct inst *fntop = fr->pc;
            struct inst *varinst;

            while (fntop->type != PROG_FUNCTION)
                fntop--;

            snplen = snprintf(buf2, sizeof(buf2), "%.512s\033[1m(\033[0m", ptr);

            if (snplen == -1) {
                buf2[sizeof(buf2) - 1] = '\0';
                snplen = sizeof(buf2) - 1;
            }

            bufend += snplen;

            for (int k = 0; k < fntop->data.mufproc->args; k++) {
                const char *nam = scopedvar_getname(fr, lev, k);
                char *val;

                if (!nam) {
                    break;
                }

                varinst = scopedvar_get(fr, lev, k);
                val = insttotext(fr, lev, varinst, buf3, sizeof(buf3), 30, program, 1);

                if (k) {
                    bufend += snprintf(bufend, buf2 - bufend - 18, "\033[1m, %s=\033[0m%s", nam, val);
                } else {
                    bufend += snprintf(bufend, buf2 - bufend - 18, "\033[1m%s=\033[0m%s", nam, val);
                }
            }

            ptr = buf2;
        }

        if (pinst != lastinst) {
            notifyf_nolisten(player, "\033[1;33;40m%3d)\033[0m \033[1m%s(#%d)\033[0m %s:", lev,
                             NAME(ref), ref, ptr);
            flag = ((FLAGS(player) & INTERNAL) ? 1 : 0);
            FLAGS(player) &= ~INTERNAL;
            list_proglines(player, ref, fr, pinst->line, 0);

            if (flag) {
                FLAGS(player) |= INTERNAL;
            }
        }
    }

    notify_nolisten(player, "\033[1;33;40m*done*\033[0m", 1);
}