src/main/java/org/luaj/vm3/Print.java - minecraft/opencomputers - Rivoreo Source Code Repositories

 /*******************************************************************************
 * Copyright (c) 2009 Luaj.org. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
 package org.luaj.vm3;

 import java.io.ByteArrayOutputStream;
 import java.io.PrintStream;

 /**
  * Debug helper class to pretty-print lua bytecodes.
  * @see Prototype
  * @see LuaClosure
  */
 public class Print extends Lua {

 	/** opcode names */
 	private static final String STRING_FOR_NULL = "null";
 	public static PrintStream ps = System.out;

 	/** String names for each lua opcode value. */
 	public static final String[] OPNAMES = { "MOVE", "LOADK", "LOADKX", "LOADBOOL", "LOADNIL", "GETUPVAL", "GETTABUP", "GETTABLE", "SETTABUP", "SETUPVAL", "SETTABLE", "NEWTABLE", "SELF", "ADD", "SUB", "MUL", "DIV", "MOD", "POW", "UNM", "NOT", "LEN", "CONCAT", "JMP", "EQ", "LT", "LE", "TEST", "TESTSET", "CALL", "TAILCALL", "RETURN", "FORLOOP", "FORPREP", "TFORCALL", "TFORLOOP", "SETLIST", "CLOSURE", "VARARG", "EXTRAARG", null, };

 	static void printString(PrintStream ps, final LuaString s) {

 		ps.print('"');
 		for (int i = 0, n = s.m_length; i < n; i++) {
 			int c = s.m_bytes[s.m_offset + i];
 			if (c >= ' ' && c <= '~' && c != '\"' && c != '\\')
 				ps.print((char) c);
 			else {
 				switch (c) {
 				case '"':
 					ps.print("\\\"");
 					break;
 				case '\\':
 					ps.print("\\\\");
 					break;
 				case 0x0007: /* bell */
 					ps.print("\\a");
 					break;
 				case '\b': /* backspace */
 					ps.print("\\b");
 					break;
 				case '\f': /* form feed */
 					ps.print("\\f");
 					break;
 				case '\t': /* tab */
 					ps.print("\\t");
 					break;
 				case '\r': /* carriage return */
 					ps.print("\\r");
 					break;
 				case '\n': /* newline */
 					ps.print("\\n");
 					break;
 				case 0x000B: /* vertical tab */
 					ps.print("\\v");
 					break;
 				default:
 					ps.print('\\');
 					ps.print(Integer.toString(1000 + 0xff & c).substring(1));
 					break;
 				}
 			}
 		}
 		ps.print('"');
 	}

 	static void printValue(PrintStream ps, LuaValue v) {
 		switch (v.type()) {
 		case LuaValue.TSTRING:
 			printString(ps, (LuaString) v);
 			break;
 		default:
 			ps.print(v.tojstring());

 		}
 	}

 	static void printConstant(PrintStream ps, Prototype f, int i) {
 		printValue(ps, f.k[i]);
 	}

 	static void printUpvalue(PrintStream ps, Upvaldesc u) {
 		ps.print(u.idx + " ");
 		printValue(ps, u.name);
 	}

 	/**
 	 * Print the code in a prototype
 	 * @param f the {@link Prototype}
 	 */
 	public static void printCode(Prototype f) {
 		int[] code = f.code;
 		int pc, n = code.length;
 		for (pc = 0; pc < n; pc++) {
 			printOpCode(f, pc);
 			ps.println();
 		}
 	}

 	/**
 	 * Print an opcode in a prototype
 	 * @param f the {@link Prototype}
 	 * @param pc the program counter to look up and print
 	 */
 	public static void printOpCode(Prototype f, int pc) {
 		printOpCode(ps, f, pc);
 	}

 	/**
 	 * Print an opcode in a prototype
 	 * @param ps the {@link PrintStream} to print to
 	 * @param f the {@link Prototype}
 	 * @param pc the program counter to look up and print
 	 */
 	public static void printOpCode(PrintStream ps, Prototype f, int pc) {
 		int[] code = f.code;
 		int i = code[pc];
 		int o = GET_OPCODE(i);
 		int a = GETARG_A(i);
 		int b = GETARG_B(i);
 		int c = GETARG_C(i);
 		int bx = GETARG_Bx(i);
 		int sbx = GETARG_sBx(i);
 		int line = getline(f, pc);
 		ps.print("  " + (pc + 1) + "  ");
 		if (line > 0)
 			ps.print("[" + line + "]  ");
 		else
 			ps.print("[-]  ");
 		ps.print(OPNAMES[o] + "  ");
 		switch (getOpMode(o)) {
 		case iABC:
 			ps.print(a);
 			if (getBMode(o) != OpArgN)
 				ps.print(" " + (ISK(b) ? (-1 - INDEXK(b)) : b));
 			if (getCMode(o) != OpArgN)
 				ps.print(" " + (ISK(c) ? (-1 - INDEXK(c)) : c));
 			break;
 		case iABx:
 			if (getBMode(o) == OpArgK) {
 				ps.print(a + " " + (-1 - bx));
 			} else {
 				ps.print(a + " " + (bx));
 			}
 			break;
 		case iAsBx:
 			if (o == OP_JMP)
 				ps.print(sbx);
 			else
 				ps.print(a + " " + sbx);
 			break;
 		}
 		switch (o) {
 		case OP_LOADK:
 			ps.print("  ; ");
 			printConstant(ps, f, bx);
 			break;
 		case OP_GETUPVAL:
 		case OP_SETUPVAL:
 			ps.print("  ; ");
 			printUpvalue(ps, f.upvalues[b]);
 			break;
 		case OP_GETTABUP:
 			ps.print("  ; ");
 			printUpvalue(ps, f.upvalues[b]);
 			ps.print(" ");
 			if (ISK(c))
 				printConstant(ps, f, INDEXK(c));
 			else
 				ps.print("-");
 			break;
 		case OP_SETTABUP:
 			ps.print("  ; ");
 			printUpvalue(ps, f.upvalues[a]);
 			ps.print(" ");
 			if (ISK(b))
 				printConstant(ps, f, INDEXK(b));
 			else
 				ps.print("-");
 			ps.print(" ");
 			if (ISK(c))
 				printConstant(ps, f, INDEXK(c));
 			else
 				ps.print("-");
 			break;
 		case OP_GETTABLE:
 		case OP_SELF:
 			if (ISK(c)) {
 				ps.print("  ; ");
 				printConstant(ps, f, INDEXK(c));
 			}
 			break;
 		case OP_SETTABLE:
 		case OP_ADD:
 		case OP_SUB:
 		case OP_MUL:
 		case OP_DIV:
 		case OP_POW:
 		case OP_EQ:
 		case OP_LT:
 		case OP_LE:
 			if (ISK(b) || ISK(c)) {
 				ps.print("  ; ");
 				if (ISK(b))
 					printConstant(ps, f, INDEXK(b));
 				else
 					ps.print("-");
 				ps.print(" ");
 				if (ISK(c))
 					printConstant(ps, f, INDEXK(c));
 				else
 					ps.print("-");
 			}
 			break;
 		case OP_JMP:
 		case OP_FORLOOP:
 		case OP_FORPREP:
 			ps.print("  ; to " + (sbx + pc + 2));
 			break;
 		case OP_CLOSURE:
 			ps.print("  ; " + f.p[bx].getClass().getName());
 			break;
 		case OP_SETLIST:
 			if (c == 0)
 				ps.print("  ; " + ((int) code[++pc]));
 			else
 				ps.print("  ; " + ((int) c));
 			break;
 		case OP_VARARG:
 			ps.print("  ; is_vararg=" + f.is_vararg);
 			break;
 		default:
 			break;
 		}
 	}

 	private static int getline(Prototype f, int pc) {
 		return pc > 0 && f.lineinfo != null && pc < f.lineinfo.length ? f.lineinfo[pc] : -1;
 	}

 	static void printHeader(Prototype f) {
 		String s = String.valueOf(f.source);
 		if (s.startsWith("@") || s.startsWith("="))
 			s = s.substring(1);
 		else if ("\033Lua".equals(s))
 			s = "(bstring)";
 		else
 			s = "(string)";
 		String a = (f.linedefined == 0) ? "main" : "function";
 		ps.print("\n%" + a + " <" + s + ":" + f.linedefined + "," + f.lastlinedefined + "> (" + f.code.length + " instructions, " + f.code.length * 4 + " bytes at " + id(f) + ")\n");
 		ps.print(f.numparams + " param, " + f.maxstacksize + " slot, " + f.upvalues.length + " upvalue, ");
 		ps.print(f.locvars.length + " local, " + f.k.length + " constant, " + f.p.length + " function\n");
 	}

 	static void printConstants(Prototype f) {
 		int i, n = f.k.length;
 		ps.print("constants (" + n + ") for " + id(f) + ":\n");
 		for (i = 0; i < n; i++) {
 			ps.print("  " + (i + 1) + "  ");
 			printValue(ps, f.k[i]);
 			ps.print("\n");
 		}
 	}

 	static void printLocals(Prototype f) {
 		int i, n = f.locvars.length;
 		ps.print("locals (" + n + ") for " + id(f) + ":\n");
 		for (i = 0; i < n; i++) {
 			ps.println("  " + i + "  " + f.locvars[i].varname + " " + (f.locvars[i].startpc + 1) + " " + (f.locvars[i].endpc + 1));
 		}
 	}

 	static void printUpValues(Prototype f) {
 		int i, n = f.upvalues.length;
 		ps.print("upvalues (" + n + ") for " + id(f) + ":\n");
 		for (i = 0; i < n; i++) {
 			ps.print("  " + i + "  " + f.upvalues[i] + "\n");
 		}
 	}

 	/** Pretty-prints contents of a Prototype.
 	 *
 	 * @param prototype Prototype to print.
 	 */
 	public static void print(Prototype prototype) {
 		printFunction(prototype, true);
 	}

 	/** Pretty-prints contents of a Prototype in short or long form.
 	 *
 	 * @param prototype Prototype to print.
 	 * @param full true to print all fields, false to print short form.
 	 */
 	public static void printFunction(Prototype prototype, boolean full) {
 		int i, n = prototype.p.length;
 		printHeader(prototype);
 		printCode(prototype);
 		if (full) {
 			printConstants(prototype);
 			printLocals(prototype);
 			printUpValues(prototype);
 		}
 		for (i = 0; i < n; i++)
 			printFunction(prototype.p[i], full);
 	}

 	private static void format(String s, int maxcols) {
 		int n = s.length();
 		if (n > maxcols)
 			ps.print(s.substring(0, maxcols));
 		else {
 			ps.print(s);
 			for (int i = maxcols - n; --i >= 0;)
 				ps.print(' ');
 		}
 	}

 	private static String id(Prototype f) {
 		return "Proto";
 	}

 	private void _assert(boolean b) {
 		if (!b)
 			throw new NullPointerException("_assert failed");
 	}

 	/**
 	 * Print the state of a {@link LuaClosure} that is being executed
 	 * @param cl the {@link LuaClosure}
 	 * @param pc the program counter
 	 * @param stack the stack of {@link LuaValue}
 	 * @param top the top of the stack
 	 * @param varargs any {@link Varargs} value that may apply
 	 */
 	public static void printState(LuaClosure cl, int pc, LuaValue[] stack, int top, Varargs varargs) {
 		// print opcode into buffer
 		PrintStream previous = ps;
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
 		ps = new PrintStream(baos);
 		printOpCode(cl.p, pc);
 		ps.flush();
 		ps.close();
 		ps = previous;
 		format(baos.toString(), 50);

 		// print stack
 		ps.print('[');
 		for (int i = 0; i < stack.length; i++) {
 			LuaValue v = stack[i];
 			if (v == null)
 				ps.print(STRING_FOR_NULL);
 			else
 				switch (v.type()) {
 				case LuaValue.TSTRING:
 					LuaString s = v.checkstring();
 					ps.print(s.length() < 48 ? s.tojstring() : s.substring(0, 32).tojstring() + "...+" + (s.length() - 32) + "b");
 					break;
 				case LuaValue.TFUNCTION:
 					ps.print(v.tojstring());
 					break;
 				case LuaValue.TUSERDATA:
 					Object o = v.touserdata();
 					if (o != null) {
 						String n = o.getClass().getName();
 						n = n.substring(n.lastIndexOf('.') + 1);
 						ps.print(n + ": " + Integer.toHexString(o.hashCode()));
 					} else {
 						ps.print(v.toString());
 					}
 					break;
 				default:
 					ps.print(v.tojstring());
 				}
 			if (i + 1 == top)
 				ps.print(']');
 			ps.print(" | ");
 		}
 		ps.print(varargs);
 		ps.println();
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2009 Luaj.org. All rights reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	******************************************************************************/
	package org.luaj.vm3;

	import java.io.ByteArrayOutputStream;
	import java.io.PrintStream;

	/**
	* Debug helper class to pretty-print lua bytecodes.
	* @see Prototype
	* @see LuaClosure
	*/
	public class Print extends Lua {

	/** opcode names */
	private static final String STRING_FOR_NULL = "null";
	public static PrintStream ps = System.out;

	/** String names for each lua opcode value. */
	public static final String[] OPNAMES = { "MOVE", "LOADK", "LOADKX", "LOADBOOL", "LOADNIL", "GETUPVAL", "GETTABUP", "GETTABLE", "SETTABUP", "SETUPVAL", "SETTABLE", "NEWTABLE", "SELF", "ADD", "SUB", "MUL", "DIV", "MOD", "POW", "UNM", "NOT", "LEN", "CONCAT", "JMP", "EQ", "LT", "LE", "TEST", "TESTSET", "CALL", "TAILCALL", "RETURN", "FORLOOP", "FORPREP", "TFORCALL", "TFORLOOP", "SETLIST", "CLOSURE", "VARARG", "EXTRAARG", null, };

	static void printString(PrintStream ps, final LuaString s) {

	ps.print('"');
	for (int i = 0, n = s.m_length; i < n; i++) {
	int c = s.m_bytes[s.m_offset + i];
	if (c >= ' ' && c <= '~' && c != '\"' && c != '\\')
	ps.print((char) c);
	else {
	switch (c) {
	case '"':
	ps.print("\\\"");
	break;
	case '\\':
	ps.print("\\\\");
	break;
	case 0x0007: /* bell */
	ps.print("\\a");
	break;
	case '\b': /* backspace */
	ps.print("\\b");
	break;
	case '\f': /* form feed */
	ps.print("\\f");
	break;
	case '\t': /* tab */
	ps.print("\\t");
	break;
	case '\r': /* carriage return */
	ps.print("\\r");
	break;
	case '\n': /* newline */
	ps.print("\\n");
	break;
	case 0x000B: /* vertical tab */
	ps.print("\\v");
	break;
	default:
	ps.print('\\');
	ps.print(Integer.toString(1000 + 0xff & c).substring(1));
	break;
	}
	}
	}
	ps.print('"');
	}

	static void printValue(PrintStream ps, LuaValue v) {
	switch (v.type()) {
	case LuaValue.TSTRING:
	printString(ps, (LuaString) v);
	break;
	default:
	ps.print(v.tojstring());

	}
	}

	static void printConstant(PrintStream ps, Prototype f, int i) {
	printValue(ps, f.k[i]);
	}

	static void printUpvalue(PrintStream ps, Upvaldesc u) {
	ps.print(u.idx + " ");
	printValue(ps, u.name);
	}

	/**
	* Print the code in a prototype
	* @param f the {@link Prototype}
	*/
	public static void printCode(Prototype f) {
	int[] code = f.code;
	int pc, n = code.length;
	for (pc = 0; pc < n; pc++) {
	printOpCode(f, pc);
	ps.println();
	}
	}

	/**
	* Print an opcode in a prototype
	* @param f the {@link Prototype}
	* @param pc the program counter to look up and print
	*/
	public static void printOpCode(Prototype f, int pc) {
	printOpCode(ps, f, pc);
	}

	/**
	* Print an opcode in a prototype
	* @param ps the {@link PrintStream} to print to
	* @param f the {@link Prototype}
	* @param pc the program counter to look up and print
	*/
	public static void printOpCode(PrintStream ps, Prototype f, int pc) {
	int[] code = f.code;
	int i = code[pc];
	int o = GET_OPCODE(i);
	int a = GETARG_A(i);
	int b = GETARG_B(i);
	int c = GETARG_C(i);
	int bx = GETARG_Bx(i);
	int sbx = GETARG_sBx(i);
	int line = getline(f, pc);
	ps.print(" " + (pc + 1) + " ");
	if (line > 0)
	ps.print("[" + line + "] ");
	else
	ps.print("[-] ");
	ps.print(OPNAMES[o] + " ");
	switch (getOpMode(o)) {
	case iABC:
	ps.print(a);
	if (getBMode(o) != OpArgN)
	ps.print(" " + (ISK(b) ? (-1 - INDEXK(b)) : b));
	if (getCMode(o) != OpArgN)
	ps.print(" " + (ISK(c) ? (-1 - INDEXK(c)) : c));
	break;
	case iABx:
	if (getBMode(o) == OpArgK) {
	ps.print(a + " " + (-1 - bx));
	} else {
	ps.print(a + " " + (bx));
	}
	break;
	case iAsBx:
	if (o == OP_JMP)
	ps.print(sbx);
	else
	ps.print(a + " " + sbx);
	break;
	}
	switch (o) {
	case OP_LOADK:
	ps.print(" ; ");
	printConstant(ps, f, bx);
	break;
	case OP_GETUPVAL:
	case OP_SETUPVAL:
	ps.print(" ; ");
	printUpvalue(ps, f.upvalues[b]);
	break;
	case OP_GETTABUP:
	ps.print(" ; ");
	printUpvalue(ps, f.upvalues[b]);
	ps.print(" ");
	if (ISK(c))
	printConstant(ps, f, INDEXK(c));
	else
	ps.print("-");
	break;
	case OP_SETTABUP:
	ps.print(" ; ");
	printUpvalue(ps, f.upvalues[a]);
	ps.print(" ");
	if (ISK(b))
	printConstant(ps, f, INDEXK(b));
	else
	ps.print("-");
	ps.print(" ");
	if (ISK(c))
	printConstant(ps, f, INDEXK(c));
	else
	ps.print("-");
	break;
	case OP_GETTABLE:
	case OP_SELF:
	if (ISK(c)) {
	ps.print(" ; ");
	printConstant(ps, f, INDEXK(c));
	}
	break;
	case OP_SETTABLE:
	case OP_ADD:
	case OP_SUB:
	case OP_MUL:
	case OP_DIV:
	case OP_POW:
	case OP_EQ:
	case OP_LT:
	case OP_LE:
	if (ISK(b) \|\| ISK(c)) {
	ps.print(" ; ");
	if (ISK(b))
	printConstant(ps, f, INDEXK(b));
	else
	ps.print("-");
	ps.print(" ");
	if (ISK(c))
	printConstant(ps, f, INDEXK(c));
	else
	ps.print("-");
	}
	break;
	case OP_JMP:
	case OP_FORLOOP:
	case OP_FORPREP:
	ps.print(" ; to " + (sbx + pc + 2));
	break;
	case OP_CLOSURE:
	ps.print(" ; " + f.p[bx].getClass().getName());
	break;
	case OP_SETLIST:
	if (c == 0)
	ps.print(" ; " + ((int) code[++pc]));
	else
	ps.print(" ; " + ((int) c));
	break;
	case OP_VARARG:
	ps.print(" ; is_vararg=" + f.is_vararg);
	break;
	default:
	break;
	}
	}

	private static int getline(Prototype f, int pc) {
	return pc > 0 && f.lineinfo != null && pc < f.lineinfo.length ? f.lineinfo[pc] : -1;
	}

	static void printHeader(Prototype f) {
	String s = String.valueOf(f.source);
	if (s.startsWith("@") \|\| s.startsWith("="))
	s = s.substring(1);
	else if ("\033Lua".equals(s))
	s = "(bstring)";
	else
	s = "(string)";
	String a = (f.linedefined == 0) ? "main" : "function";
	ps.print("\n%" + a + " <" + s + ":" + f.linedefined + "," + f.lastlinedefined + "> (" + f.code.length + " instructions, " + f.code.length * 4 + " bytes at " + id(f) + ")\n");
	ps.print(f.numparams + " param, " + f.maxstacksize + " slot, " + f.upvalues.length + " upvalue, ");
	ps.print(f.locvars.length + " local, " + f.k.length + " constant, " + f.p.length + " function\n");
	}

	static void printConstants(Prototype f) {
	int i, n = f.k.length;
	ps.print("constants (" + n + ") for " + id(f) + ":\n");
	for (i = 0; i < n; i++) {
	ps.print(" " + (i + 1) + " ");
	printValue(ps, f.k[i]);
	ps.print("\n");
	}
	}

	static void printLocals(Prototype f) {
	int i, n = f.locvars.length;
	ps.print("locals (" + n + ") for " + id(f) + ":\n");
	for (i = 0; i < n; i++) {
	ps.println(" " + i + " " + f.locvars[i].varname + " " + (f.locvars[i].startpc + 1) + " " + (f.locvars[i].endpc + 1));
	}
	}

	static void printUpValues(Prototype f) {
	int i, n = f.upvalues.length;
	ps.print("upvalues (" + n + ") for " + id(f) + ":\n");
	for (i = 0; i < n; i++) {
	ps.print(" " + i + " " + f.upvalues[i] + "\n");
	}
	}

	/** Pretty-prints contents of a Prototype.
	*
	* @param prototype Prototype to print.
	*/
	public static void print(Prototype prototype) {
	printFunction(prototype, true);
	}

	/** Pretty-prints contents of a Prototype in short or long form.
	*
	* @param prototype Prototype to print.
	* @param full true to print all fields, false to print short form.
	*/
	public static void printFunction(Prototype prototype, boolean full) {
	int i, n = prototype.p.length;
	printHeader(prototype);
	printCode(prototype);
	if (full) {
	printConstants(prototype);
	printLocals(prototype);
	printUpValues(prototype);
	}
	for (i = 0; i < n; i++)
	printFunction(prototype.p[i], full);
	}

	private static void format(String s, int maxcols) {
	int n = s.length();
	if (n > maxcols)
	ps.print(s.substring(0, maxcols));
	else {
	ps.print(s);
	for (int i = maxcols - n; --i >= 0;)
	ps.print(' ');
	}
	}

	private static String id(Prototype f) {
	return "Proto";
	}

	private void _assert(boolean b) {
	if (!b)
	throw new NullPointerException("_assert failed");
	}

	/**
	* Print the state of a {@link LuaClosure} that is being executed
	* @param cl the {@link LuaClosure}
	* @param pc the program counter
	* @param stack the stack of {@link LuaValue}
	* @param top the top of the stack
	* @param varargs any {@link Varargs} value that may apply
	*/
	public static void printState(LuaClosure cl, int pc, LuaValue[] stack, int top, Varargs varargs) {
	// print opcode into buffer
	PrintStream previous = ps;
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	ps = new PrintStream(baos);
	printOpCode(cl.p, pc);
	ps.flush();
	ps.close();
	ps = previous;
	format(baos.toString(), 50);

	// print stack
	ps.print('[');
	for (int i = 0; i < stack.length; i++) {
	LuaValue v = stack[i];
	if (v == null)
	ps.print(STRING_FOR_NULL);
	else
	switch (v.type()) {
	case LuaValue.TSTRING:
	LuaString s = v.checkstring();
	ps.print(s.length() < 48 ? s.tojstring() : s.substring(0, 32).tojstring() + "...+" + (s.length() - 32) + "b");
	break;
	case LuaValue.TFUNCTION:
	ps.print(v.tojstring());
	break;
	case LuaValue.TUSERDATA:
	Object o = v.touserdata();
	if (o != null) {
	String n = o.getClass().getName();
	n = n.substring(n.lastIndexOf('.') + 1);
	ps.print(n + ": " + Integer.toHexString(o.hashCode()));
	} else {
	ps.print(v.toString());
	}
	break;
	default:
	ps.print(v.tojstring());
	}
	if (i + 1 == top)
	ps.print(']');
	ps.print(" \| ");
	}
	ps.print(varargs);
	ps.println();
	}

	}