org/luaj/vm2/LuaClosure.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
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 * 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
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
 package org.luaj.vm2;

 /**
  * Extension of {@link LuaFunction} which executes lua bytecode.
  * <p>
  * A {@link LuaClosure} is a combination of a {@link Prototype}
  * and a {@link LuaValue} to use as an environment for execution.
  * Normally the {@link LuaValue} is a {@link Globals} in which case the environment
  * will contain standard lua libraries.
  *
  * <p>
  * There are three main ways {@link LuaClosure} instances are created:
  * <ul>
  * <li>Construct an instance using {@link #LuaClosure(Prototype, LuaValue)}</li>
  * <li>Construct it indirectly by loading a chunk via {@link Globals#load(java.io.Reader, String, LuaValue)}
  * <li>Execute the lua bytecode {@link Lua#OP_CLOSURE} as part of bytecode processing
  * </ul>
  * <p>
  * To construct it directly, the {@link Prototype} is typically created via a compiler such as {@link LuaC}:
  * <pre> {@code
  * String script = "print( 'hello, world' )";
  * InputStream is = new ByteArrayInputStream(script.getBytes());
  * Prototype p = LuaC.instance.compile(is, "script");
  * LuaValue globals = JsePlatform.standardGlobals();
  * LuaClosure f = new LuaClosure(p, globals);
  * f.call();
  * }</pre>
  * <p>
  * To construct it indirectly, the {@link Globals#load} method may be used:
  * <pre> {@code
  * Globals globals = JsePlatform.standardGlobals();
  * LuaFunction f = globals.load(new StringReader(script), "script");
  * LuaClosure c = f.checkclosure();  // This may fail if LuaJC is installed.
  * c.call();
  * }</pre>
  * <p>
  * In this example, the "checkclosure()" may fail if direct lua-to-java-bytecode
  * compiling using LuaJC is installed, because no LuaClosure is created in that case
  * and the value returned is a {@link LuaFunction} but not a {@link LuaClosure}.
  * <p>
  * Since a {@link LuaClosure} is a {@link LuaFunction} which is a {@link LuaValue},
  * all the value operations can be used directly such as:
  * <ul>
  * <li>{@link LuaValue#call()}</li>
  * <li>{@link LuaValue#call(LuaValue)}</li>
  * <li>{@link LuaValue#invoke()}</li>
  * <li>{@link LuaValue#invoke(Varargs)}</li>
  * <li>{@link LuaValue#method(String)}</li>
  * <li>{@link LuaValue#method(String,LuaValue)}</li>
  * <li>{@link LuaValue#invokemethod(String)}</li>
  * <li>{@link LuaValue#invokemethod(String,Varargs)}</li>
  * <li> ...</li>
  * </ul>
  * @see LuaValue
  * @see LuaFunction
  * @see LuaValue#isclosure()
  * @see LuaValue#checkclosure()
  * @see LuaValue#optclosure(LuaClosure)
  * @see LoadState
  * @see LoadState#compiler
  */
 public class LuaClosure extends LuaFunction {
 	private static final UpValue[] NOUPVALUES = new UpValue[0];

 	public final Prototype p;

 	public UpValue[] upValues;

 	final Globals globals;

 	/** Create a closure around a Prototype with a specific environment.
 	 * If the prototype has upvalues, the environment will be written into the first upvalue.
 	 * @param p the Prototype to construct this Closure for.
 	 * @param env the environment to associate with the closure.
 	 */
 	public LuaClosure(Prototype p, LuaValue env) {
 		this.p = p;
 		if (p.upvalues == null || p.upvalues.length == 0)
 			this.upValues = NOUPVALUES;
 		else {
 			this.upValues = new UpValue[p.upvalues.length];
 			this.upValues[0] = new UpValue(new LuaValue[] {env}, 0);
 		}
 		globals = env instanceof Globals? (Globals) env: null;
 	}

 	public boolean isclosure() {
 		return true;
 	}

 	public LuaClosure optclosure(LuaClosure defval) {
 		return this;
 	}

 	public LuaClosure checkclosure() {
 		return this;
 	}

 	public LuaValue getmetatable() {
 		return s_metatable;
 	}

 	public String tojstring() {
 		return "function: " + p.toString();
 	}

 	public final LuaValue call() {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		for (int i = 0; i < p.numparams; ++i )
 			stack[i] = NIL;
 		return execute(stack,NONE).arg1();
 	}

 	public final LuaValue call(LuaValue arg) {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		System.arraycopy(NILS, 0, stack, 0, p.maxstacksize);
 		for (int i = 1; i < p.numparams; ++i )
 			stack[i] = NIL;
 		switch ( p.numparams ) {
 		default: stack[0]=arg; return execute(stack,NONE).arg1();
 		case 0: return execute(stack,arg).arg1();
 		}
 	}

 	public final LuaValue call(LuaValue arg1, LuaValue arg2) {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		for (int i = 2; i < p.numparams; ++i )
 			stack[i] = NIL;
 		switch ( p.numparams ) {
 		default: stack[0]=arg1; stack[1]=arg2; return execute(stack,NONE).arg1();
 		case 1: stack[0]=arg1; return execute(stack,arg2).arg1();
 		case 0: return execute(stack,p.is_vararg!=0? varargsOf(arg1,arg2): NONE).arg1();
 		}
 	}

 	public final LuaValue call(LuaValue arg1, LuaValue arg2, LuaValue arg3) {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		for (int i = 3; i < p.numparams; ++i )
 			stack[i] = NIL;
 		switch ( p.numparams ) {
 		default: stack[0]=arg1; stack[1]=arg2; stack[2]=arg3; return execute(stack,NONE).arg1();
 		case 2: stack[0]=arg1; stack[1]=arg2; return execute(stack,arg3).arg1();
 		case 1: stack[0]=arg1; return execute(stack,p.is_vararg!=0? varargsOf(arg2,arg3): NONE).arg1();
 		case 0: return execute(stack,p.is_vararg!=0? varargsOf(arg1,arg2,arg3): NONE).arg1();
 		}
 	}

 	public final Varargs invoke(Varargs varargs) {
 		return onInvoke(varargs).eval();
 	}

 	public final Varargs onInvoke(Varargs varargs) {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		for ( int i=0; i<p.numparams; i++ )
 			stack[i] = varargs.arg(i+1);
 		return execute(stack,p.is_vararg!=0? varargs.subargs(p.numparams+1): NONE);
 	}

 	protected Varargs execute( LuaValue[] stack, Varargs varargs ) {
 		// loop through instructions
 		int i,a,b,c,pc=0,top=0;
 		LuaValue o;
 		Varargs v = NONE;
 		int[] code = p.code;
 		LuaValue[] k = p.k;

 		// upvalues are only possible when closures create closures
 		// TODO: use linked list.
 		UpValue[] openups = p.p.length>0? new UpValue[stack.length]: null;

 		// allow for debug hooks
 		if (globals != null && globals.debuglib != null)
 			globals.debuglib.onCall( this, varargs, stack );

 		// process instructions
 		try {
 			while ( true ) {
 				if (globals != null && globals.debuglib != null)
 					globals.debuglib.onInstruction( pc, v, top );

 				// pull out instruction
 				i = code[pc++];
 				a = ((i>>6) & 0xff);

 				// process the op code
 				switch ( i & 0x3f ) {

 				case Lua.OP_MOVE:/*	A B	R(A):= R(B)					*/
 					stack[a] = stack[i>>>23];
 					continue;

 				case Lua.OP_LOADK:/*	A Bx	R(A):= Kst(Bx)					*/
 					stack[a] = k[i>>>14];
 					continue;

 				case Lua.OP_LOADBOOL:/*	A B C	R(A):= (Bool)B: if (C) pc++			*/
 	                stack[a] = (i>>>23!=0)? LuaValue.TRUE: LuaValue.FALSE;
 	                if ((i&(0x1ff<<14)) != 0)
 	                    pc++; /* skip next instruction (if C) */
 	                continue;

 				case Lua.OP_LOADNIL: /*	A B	R(A):= ...:= R(A+B):= nil			*/
 					for ( b=i>>>23; b-->=0; )
 						stack[a++] = LuaValue.NIL;
 					continue;

 				case Lua.OP_GETUPVAL: /*	A B	R(A):= UpValue[B]				*/
 	                stack[a] = upValues[i>>>23].getValue();
 	                continue;

 				case Lua.OP_GETTABUP: /*	A B C	R(A) := UpValue[B][RK(C)]			*/
 					stack[a] = upValues[i>>>23].getValue().get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_GETTABLE: /*	A B C	R(A):= R(B)[RK(C)]				*/
 	                stack[a] = stack[i>>>23].get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_SETTABUP: /*	A B C	UpValue[A][RK(B)] := RK(C)			*/
 	                upValues[a].getValue().set(((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]), (c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_SETUPVAL: /*	A B	UpValue[B]:= R(A)				*/
 					upValues[i>>>23].setValue(stack[a]);
 					continue;

 				case Lua.OP_SETTABLE: /*	A B C	R(A)[RK(B)]:= RK(C)				*/
 					stack[a].set(((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]), (c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_NEWTABLE: /*	A B C	R(A):= {} (size = B,C)				*/
 					stack[a] = new LuaTable(i>>>23,(i>>14)&0x1ff);
 					continue;

 				case Lua.OP_SELF: /*	A B C	R(A+1):= R(B): R(A):= R(B)[RK(C)]		*/
 					stack[a+1] = (o = stack[i>>>23]);
 					stack[a] = o.get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_ADD: /*	A B C	R(A):= RK(B) + RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).add((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_SUB: /*	A B C	R(A):= RK(B) - RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).sub((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_MUL: /*	A B C	R(A):= RK(B) * RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).mul((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_DIV: /*	A B C	R(A):= RK(B) / RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).div((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_MOD: /*	A B C	R(A):= RK(B) % RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).mod((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_POW: /*	A B C	R(A):= RK(B) ^ RK(C)				*/
 					stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).pow((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
 					continue;

 				case Lua.OP_UNM: /*	A B	R(A):= -R(B)					*/
 					stack[a] = stack[i>>>23].neg();
 					continue;

 				case Lua.OP_NOT: /*	A B	R(A):= not R(B)				*/
 					stack[a] = stack[i>>>23].not();
 					continue;

 				case Lua.OP_LEN: /*	A B	R(A):= length of R(B)				*/
 					stack[a] = stack[i>>>23].len();
 					continue;

 				case Lua.OP_CONCAT: /*	A B C	R(A):= R(B).. ... ..R(C)			*/
 					b = i>>>23;
 					c = (i>>14)&0x1ff;
 					{
 						if ( c > b+1 ) {
 							Buffer sb = stack[c].buffer();
 							while ( --c>=b )
 								sb = stack[c].concat(sb);
 							stack[a] = sb.value();
 						} else {
 							stack[a] = stack[c-1].concat(stack[c]);
 						}
 					}
 					continue;

 				case Lua.OP_JMP: /*	sBx	pc+=sBx					*/
 					pc  += (i>>>14)-0x1ffff;
 					if (a > 0) {
 						for (--a, b = openups.length; --b>=0; )
 							if (openups[b] != null && openups[b].index >= a) {
 								openups[b].close();
 								openups[b] = null;
 							}
 					}
 					continue;

 				case Lua.OP_EQ: /*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
 					if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).eq_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
 						++pc;
 					continue;

 				case Lua.OP_LT: /*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++  		*/
 					if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).lt_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
 						++pc;
 					continue;

 				case Lua.OP_LE: /*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++  		*/
 					if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).lteq_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
 						++pc;
 					continue;

 				case Lua.OP_TEST: /*	A C	if not (R(A) <=> C) then pc++			*/
 					if ( stack[a].toboolean() != ((i&(0x1ff<<14))!=0) )
 						++pc;
 					continue;

 				case Lua.OP_TESTSET: /*	A B C	if (R(B) <=> C) then R(A):= R(B) else pc++	*/
 					/* note: doc appears to be reversed */
 					if ( (o=stack[i>>>23]).toboolean() != ((i&(0x1ff<<14))!=0) )
 						++pc;
 					else
 						stack[a] = o; // TODO: should be sBx?
 					continue;

 				case Lua.OP_CALL: /*	A B C	R(A), ... ,R(A+C-2):= R(A)(R(A+1), ... ,R(A+B-1)) */
 					switch ( i & (Lua.MASK_B | Lua.MASK_C) ) {
 					case (1<<Lua.POS_B) | (0<<Lua.POS_C): v=stack[a].invoke(NONE); top=a+v.narg(); continue;
 					case (2<<Lua.POS_B) | (0<<Lua.POS_C): v=stack[a].invoke(stack[a+1]); top=a+v.narg(); continue;
 					case (1<<Lua.POS_B) | (1<<Lua.POS_C): stack[a].call(); continue;
 					case (2<<Lua.POS_B) | (1<<Lua.POS_C): stack[a].call(stack[a+1]); continue;
 					case (3<<Lua.POS_B) | (1<<Lua.POS_C): stack[a].call(stack[a+1],stack[a+2]); continue;
 					case (4<<Lua.POS_B) | (1<<Lua.POS_C): stack[a].call(stack[a+1],stack[a+2],stack[a+3]); continue;
 					case (1<<Lua.POS_B) | (2<<Lua.POS_C): stack[a] = stack[a].call(); continue;
 					case (2<<Lua.POS_B) | (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1]); continue;
 					case (3<<Lua.POS_B) | (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1],stack[a+2]); continue;
 					case (4<<Lua.POS_B) | (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1],stack[a+2],stack[a+3]); continue;
 					default:
 						b = i>>>23;
 						c = (i>>14)&0x1ff;
 						v = b>0?
 							varargsOf(stack,a+1,b-1): // exact arg count
 							varargsOf(stack, a+1, top-v.narg()-(a+1), v); // from prev top
 						v = stack[a].invoke(v);
 						if ( c > 0 ) {
 							while ( --c > 0 )
 								stack[a+c-1] = v.arg(c);
 							v = NONE; // TODO: necessary?
 						} else {
 							top = a + v.narg();
 						}
 						continue;
 					}

 				case Lua.OP_TAILCALL: /*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
 					switch ( i & Lua.MASK_B ) {
 					case (1<<Lua.POS_B): return new TailcallVarargs(stack[a], NONE);
 					case (2<<Lua.POS_B): return new TailcallVarargs(stack[a], stack[a+1]);
 					case (3<<Lua.POS_B): return new TailcallVarargs(stack[a], varargsOf(stack[a+1],stack[a+2]));
 					case (4<<Lua.POS_B): return new TailcallVarargs(stack[a], varargsOf(stack[a+1],stack[a+2],stack[a+3]));
 					default:
 						b = i>>>23;
 						v = b>0?
 							varargsOf(stack,a+1,b-1): // exact arg count
 							varargsOf(stack, a+1, top-v.narg()-(a+1), v); // from prev top
 						return new TailcallVarargs( stack[a], v );
 					}

 				case Lua.OP_RETURN: /*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
 					b = i>>>23;
 					switch ( b ) {
 					case 0: return varargsOf(stack, a, top-v.narg()-a, v);
 					case 1: return NONE;
 					case 2: return stack[a];
 					default:
 						return varargsOf(stack, a, b-1);
 					}

 				case Lua.OP_FORLOOP: /*	A sBx	R(A)+=R(A+2): if R(A) <?= R(A+1) then { pc+=sBx: R(A+3)=R(A) }*/
 					{
 			            LuaValue limit = stack[a + 1];
 						LuaValue step  = stack[a + 2];
 						LuaValue idx   = step.add(stack[a]);
 			            if (step.gt_b(0)? idx.lteq_b(limit): idx.gteq_b(limit)) {
 		                    stack[a] = idx;
 		                    stack[a + 3] = idx;
 		                    pc += (i>>>14)-0x1ffff;
 			            }
 					}
 					continue;

 				case Lua.OP_FORPREP: /*	A sBx	R(A)-=R(A+2): pc+=sBx				*/
 					{
 						LuaValue init  = stack[a].checknumber("'for' initial value must be a number");
 						LuaValue limit = stack[a + 1].checknumber("'for' limit must be a number");
 						LuaValue step  = stack[a + 2].checknumber("'for' step must be a number");
 						stack[a] = init.sub(step);
 						stack[a + 1] = limit;
 						stack[a + 2] = step;
 						pc += (i>>>14)-0x1ffff;
 					}
 					continue;

 				case Lua.OP_TFORCALL: /* A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
 					v = stack[a].invoke(varargsOf(stack[a+1],stack[a+2]));
 					c = (i>>14) & 0x1ff;
 					while (--c >= 0)
 						stack[a+3+c] = v.arg(c+1);
 					v = NONE;
 					continue;

 				case Lua.OP_TFORLOOP: /* A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx */
 					if (!stack[a+1].isnil()) { /* continue loop? */
 						stack[a] = stack[a+1];  /* save control varible. */
 						pc += (i>>>14)-0x1ffff;
 					}
 					continue;

 				case Lua.OP_SETLIST: /*	A B C	R(A)[(C-1)*FPF+i]:= R(A+i), 1 <= i <= B	*/
 					{
 		                if ( (c=(i>>14)&0x1ff) == 0 )
 		                    c = code[pc++];
 		                int offset = (c-1) * Lua.LFIELDS_PER_FLUSH;
 		                o = stack[a];
 		                if ( (b=i>>>23) == 0 ) {
 		                    b = top - a - 1;
 		                    int m = b - v.narg();
 		                	int j=1;
 		                	for ( ;j<=m; j++ )
 		                    	o.set(offset+j, stack[a + j]);
 		                	for ( ;j<=b; j++ )
 		                    	o.set(offset+j, v.arg(j-m));
 		                } else {
 		                    o.presize( offset + b );
 		                    for (int j=1; j<=b; j++)
 		                    	o.set(offset+j, stack[a + j]);
 		                }
 					}
 					continue;

 				case Lua.OP_CLOSURE: /*	A Bx	R(A):= closure(KPROTO[Bx])	*/
 					{
 						Prototype newp = p.p[i>>>14];
 						LuaClosure ncl = new LuaClosure(newp, globals);
 						Upvaldesc[] uv = newp.upvalues;
 						for ( int j=0, nup=uv.length; j<nup; ++j ) {
 							if (uv[j].instack)  /* upvalue refes to local variable? */
 								ncl.upValues[j] = findupval(stack, uv[j].idx, openups);
 							else  /* get upvalue from enclosing function */
 								ncl.upValues[j] = upValues[uv[j].idx];
 						}
 						stack[a] = ncl;
 					}
 					continue;

 				case Lua.OP_VARARG: /*	A B	R(A), R(A+1), ..., R(A+B-1) = vararg		*/
 					b = i>>>23;
 					if ( b == 0 ) {
 						top = a + (b = varargs.narg());
 						v = varargs;
 					} else {
 						for ( int j=1; j<b; ++j )
 							stack[a+j-1] = varargs.arg(j);
 					}
 					continue;

 				case Lua.OP_EXTRAARG:
 					throw new java.lang.IllegalArgumentException("Uexecutable opcode: OP_EXTRAARG");

 				default:
 					throw new java.lang.IllegalArgumentException("Illegal opcode: " + (i & 0x3f));
 				}
 			}
 		} catch ( LuaError le ) {
 			if (le.traceback == null)
 				processErrorHooks(le, p, pc);
 			throw le;
 		} catch ( Exception e ) {
 			LuaError le = new LuaError(e);
 			processErrorHooks(le, p, pc);
 			throw le;
 		} finally {
 			if ( openups != null )
 				for ( int u=openups.length; --u>=0; )
 					if ( openups[u] != null )
 						openups[u].close();
 			if (globals != null && globals.debuglib != null)
 				globals.debuglib.onReturn();
 		}
 	}

 	/**
 	 *  Run the error hook if there is one
 	 *  @param msg the message to use in error hook processing.
 	 * */
 	String errorHook(String msg, int level) {
 		if (globals == null ) return msg;
 		final LuaThread r = globals.running;
 		if (r.errorfunc == null)
 			return globals.debuglib != null?
 				msg + "\n" + globals.debuglib.traceback(level):
 				msg;
 		final LuaValue e = r.errorfunc;
 		r.errorfunc = null;
 		try {
 			return e.call( LuaValue.valueOf(msg) ).tojstring();
 		} catch ( Throwable t ) {
 			return "error in error handling";
 		} finally {
 			r.errorfunc = e;
 		}
 	}

 	private void processErrorHooks(LuaError le, Prototype p, int pc) {
 		le.fileline = (p.source != null? p.source.tojstring(): "?") + ":"
 			+ (p.lineinfo != null && pc >= 0 && pc < p.lineinfo.length? String.valueOf(p.lineinfo[pc]): "?");
 		le.traceback = errorHook(le.getMessage(), le.level);
 	}

 	private UpValue findupval(LuaValue[] stack, short idx, UpValue[] openups) {
 		final int n = openups.length;
 		for (int i = 0; i < n; ++i)
 			if (openups[i] != null && openups[i].index == idx)
 				return openups[i];
 		for (int i = 0; i < n; ++i)
 			if (openups[i] == null)
 				return openups[i] = new UpValue(stack, idx);
 		error("No space for upvalue");
 		return null;
 	}

 	protected LuaValue getUpvalue(int i) {
 		return upValues[i].getValue();
 	}

 	protected void setUpvalue(int i, LuaValue v) {
 		upValues[i].setValue(v);
 	}

 	public String name() {
 		return "<"+p.shortsource()+":"+p.linedefined+">";
 	}


 }
	/*******************************************************************************
	* 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.vm2;

	/**
	* Extension of {@link LuaFunction} which executes lua bytecode.
	* <p>
	* A {@link LuaClosure} is a combination of a {@link Prototype}
	* and a {@link LuaValue} to use as an environment for execution.
	* Normally the {@link LuaValue} is a {@link Globals} in which case the environment
	* will contain standard lua libraries.
	*
	* <p>
	* There are three main ways {@link LuaClosure} instances are created:
	* <ul>
	* <li>Construct an instance using {@link #LuaClosure(Prototype, LuaValue)}</li>
	* <li>Construct it indirectly by loading a chunk via {@link Globals#load(java.io.Reader, String, LuaValue)}
	* <li>Execute the lua bytecode {@link Lua#OP_CLOSURE} as part of bytecode processing
	* </ul>
	* <p>
	* To construct it directly, the {@link Prototype} is typically created via a compiler such as {@link LuaC}:
	* <pre> {@code
	* String script = "print( 'hello, world' )";
	* InputStream is = new ByteArrayInputStream(script.getBytes());
	* Prototype p = LuaC.instance.compile(is, "script");
	* LuaValue globals = JsePlatform.standardGlobals();
	* LuaClosure f = new LuaClosure(p, globals);
	* f.call();
	* }</pre>
	* <p>
	* To construct it indirectly, the {@link Globals#load} method may be used:
	* <pre> {@code
	* Globals globals = JsePlatform.standardGlobals();
	* LuaFunction f = globals.load(new StringReader(script), "script");
	* LuaClosure c = f.checkclosure(); // This may fail if LuaJC is installed.
	* c.call();
	* }</pre>
	* <p>
	* In this example, the "checkclosure()" may fail if direct lua-to-java-bytecode
	* compiling using LuaJC is installed, because no LuaClosure is created in that case
	* and the value returned is a {@link LuaFunction} but not a {@link LuaClosure}.
	* <p>
	* Since a {@link LuaClosure} is a {@link LuaFunction} which is a {@link LuaValue},
	* all the value operations can be used directly such as:
	* <ul>
	* <li>{@link LuaValue#call()}</li>
	* <li>{@link LuaValue#call(LuaValue)}</li>
	* <li>{@link LuaValue#invoke()}</li>
	* <li>{@link LuaValue#invoke(Varargs)}</li>
	* <li>{@link LuaValue#method(String)}</li>
	* <li>{@link LuaValue#method(String,LuaValue)}</li>
	* <li>{@link LuaValue#invokemethod(String)}</li>
	* <li>{@link LuaValue#invokemethod(String,Varargs)}</li>
	* <li> ...</li>
	* </ul>
	* @see LuaValue
	* @see LuaFunction
	* @see LuaValue#isclosure()
	* @see LuaValue#checkclosure()
	* @see LuaValue#optclosure(LuaClosure)
	* @see LoadState
	* @see LoadState#compiler
	*/
	public class LuaClosure extends LuaFunction {
	private static final UpValue[] NOUPVALUES = new UpValue[0];

	public final Prototype p;

	public UpValue[] upValues;

	final Globals globals;

	/** Create a closure around a Prototype with a specific environment.
	* If the prototype has upvalues, the environment will be written into the first upvalue.
	* @param p the Prototype to construct this Closure for.
	* @param env the environment to associate with the closure.
	*/
	public LuaClosure(Prototype p, LuaValue env) {
	this.p = p;
	if (p.upvalues == null \|\| p.upvalues.length == 0)
	this.upValues = NOUPVALUES;
	else {
	this.upValues = new UpValue[p.upvalues.length];
	this.upValues[0] = new UpValue(new LuaValue[] {env}, 0);
	}
	globals = env instanceof Globals? (Globals) env: null;
	}

	public boolean isclosure() {
	return true;
	}

	public LuaClosure optclosure(LuaClosure defval) {
	return this;
	}

	public LuaClosure checkclosure() {
	return this;
	}

	public LuaValue getmetatable() {
	return s_metatable;
	}

	public String tojstring() {
	return "function: " + p.toString();
	}

	public final LuaValue call() {
	LuaValue[] stack = new LuaValue[p.maxstacksize];
	for (int i = 0; i < p.numparams; ++i )
	stack[i] = NIL;
	return execute(stack,NONE).arg1();
	}

	public final LuaValue call(LuaValue arg) {
	LuaValue[] stack = new LuaValue[p.maxstacksize];
	System.arraycopy(NILS, 0, stack, 0, p.maxstacksize);
	for (int i = 1; i < p.numparams; ++i )
	stack[i] = NIL;
	switch ( p.numparams ) {
	default: stack[0]=arg; return execute(stack,NONE).arg1();
	case 0: return execute(stack,arg).arg1();
	}
	}

	public final LuaValue call(LuaValue arg1, LuaValue arg2) {
	LuaValue[] stack = new LuaValue[p.maxstacksize];
	for (int i = 2; i < p.numparams; ++i )
	stack[i] = NIL;
	switch ( p.numparams ) {
	default: stack[0]=arg1; stack[1]=arg2; return execute(stack,NONE).arg1();
	case 1: stack[0]=arg1; return execute(stack,arg2).arg1();
	case 0: return execute(stack,p.is_vararg!=0? varargsOf(arg1,arg2): NONE).arg1();
	}
	}

	public final LuaValue call(LuaValue arg1, LuaValue arg2, LuaValue arg3) {
	LuaValue[] stack = new LuaValue[p.maxstacksize];
	for (int i = 3; i < p.numparams; ++i )
	stack[i] = NIL;
	switch ( p.numparams ) {
	default: stack[0]=arg1; stack[1]=arg2; stack[2]=arg3; return execute(stack,NONE).arg1();
	case 2: stack[0]=arg1; stack[1]=arg2; return execute(stack,arg3).arg1();
	case 1: stack[0]=arg1; return execute(stack,p.is_vararg!=0? varargsOf(arg2,arg3): NONE).arg1();
	case 0: return execute(stack,p.is_vararg!=0? varargsOf(arg1,arg2,arg3): NONE).arg1();
	}
	}

	public final Varargs invoke(Varargs varargs) {
	return onInvoke(varargs).eval();
	}

	public final Varargs onInvoke(Varargs varargs) {
	LuaValue[] stack = new LuaValue[p.maxstacksize];
	for ( int i=0; i<p.numparams; i++ )
	stack[i] = varargs.arg(i+1);
	return execute(stack,p.is_vararg!=0? varargs.subargs(p.numparams+1): NONE);
	}

	protected Varargs execute( LuaValue[] stack, Varargs varargs ) {
	// loop through instructions
	int i,a,b,c,pc=0,top=0;
	LuaValue o;
	Varargs v = NONE;
	int[] code = p.code;
	LuaValue[] k = p.k;

	// upvalues are only possible when closures create closures
	// TODO: use linked list.
	UpValue[] openups = p.p.length>0? new UpValue[stack.length]: null;

	// allow for debug hooks
	if (globals != null && globals.debuglib != null)
	globals.debuglib.onCall( this, varargs, stack );

	// process instructions
	try {
	while ( true ) {
	if (globals != null && globals.debuglib != null)
	globals.debuglib.onInstruction( pc, v, top );

	// pull out instruction
	i = code[pc++];
	a = ((i>>6) & 0xff);

	// process the op code
	switch ( i & 0x3f ) {

	case Lua.OP_MOVE:/* A B R(A):= R(B) */
	stack[a] = stack[i>>>23];
	continue;

	case Lua.OP_LOADK:/* A Bx R(A):= Kst(Bx) */
	stack[a] = k[i>>>14];
	continue;

	case Lua.OP_LOADBOOL:/* A B C R(A):= (Bool)B: if (C) pc++ */
	stack[a] = (i>>>23!=0)? LuaValue.TRUE: LuaValue.FALSE;
	if ((i&(0x1ff<<14)) != 0)
	pc++; /* skip next instruction (if C) */
	continue;

	case Lua.OP_LOADNIL: /* A B R(A):= ...:= R(A+B):= nil */
	for ( b=i>>>23; b-->=0; )
	stack[a++] = LuaValue.NIL;
	continue;

	case Lua.OP_GETUPVAL: /* A B R(A):= UpValue[B] */
	stack[a] = upValues[i>>>23].getValue();
	continue;

	case Lua.OP_GETTABUP: /* A B C R(A) := UpValue[B][RK(C)] */
	stack[a] = upValues[i>>>23].getValue().get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_GETTABLE: /* A B C R(A):= R(B)[RK(C)] */
	stack[a] = stack[i>>>23].get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_SETTABUP: /* A B C UpValue[A][RK(B)] := RK(C) */
	upValues[a].getValue().set(((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]), (c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_SETUPVAL: /* A B UpValue[B]:= R(A) */
	upValues[i>>>23].setValue(stack[a]);
	continue;

	case Lua.OP_SETTABLE: /* A B C R(A)[RK(B)]:= RK(C) */
	stack[a].set(((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]), (c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_NEWTABLE: /* A B C R(A):= {} (size = B,C) */
	stack[a] = new LuaTable(i>>>23,(i>>14)&0x1ff);
	continue;

	case Lua.OP_SELF: /* A B C R(A+1):= R(B): R(A):= R(B)[RK(C)] */
	stack[a+1] = (o = stack[i>>>23]);
	stack[a] = o.get((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_ADD: /* A B C R(A):= RK(B) + RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).add((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_SUB: /* A B C R(A):= RK(B) - RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).sub((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_MUL: /* A B C R(A):= RK(B) * RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).mul((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_DIV: /* A B C R(A):= RK(B) / RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).div((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_MOD: /* A B C R(A):= RK(B) % RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).mod((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_POW: /* A B C R(A):= RK(B) ^ RK(C) */
	stack[a] = ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).pow((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]);
	continue;

	case Lua.OP_UNM: /* A B R(A):= -R(B) */
	stack[a] = stack[i>>>23].neg();
	continue;

	case Lua.OP_NOT: /* A B R(A):= not R(B) */
	stack[a] = stack[i>>>23].not();
	continue;

	case Lua.OP_LEN: /* A B R(A):= length of R(B) */
	stack[a] = stack[i>>>23].len();
	continue;

	case Lua.OP_CONCAT: /* A B C R(A):= R(B).. ... ..R(C) */
	b = i>>>23;
	c = (i>>14)&0x1ff;
	{
	if ( c > b+1 ) {
	Buffer sb = stack[c].buffer();
	while ( --c>=b )
	sb = stack[c].concat(sb);
	stack[a] = sb.value();
	} else {
	stack[a] = stack[c-1].concat(stack[c]);
	}
	}
	continue;

	case Lua.OP_JMP: /* sBx pc+=sBx */
	pc += (i>>>14)-0x1ffff;
	if (a > 0) {
	for (--a, b = openups.length; --b>=0; )
	if (openups[b] != null && openups[b].index >= a) {
	openups[b].close();
	openups[b] = null;
	}
	}
	continue;

	case Lua.OP_EQ: /* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */
	if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).eq_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
	++pc;
	continue;

	case Lua.OP_LT: /* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */
	if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).lt_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
	++pc;
	continue;

	case Lua.OP_LE: /* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */
	if ( ((b=i>>>23)>0xff? k[b&0x0ff]: stack[b]).lteq_b((c=(i>>14)&0x1ff)>0xff? k[c&0x0ff]: stack[c]) != (a!=0) )
	++pc;
	continue;

	case Lua.OP_TEST: /* A C if not (R(A) <=> C) then pc++ */
	if ( stack[a].toboolean() != ((i&(0x1ff<<14))!=0) )
	++pc;
	continue;

	case Lua.OP_TESTSET: /* A B C if (R(B) <=> C) then R(A):= R(B) else pc++ */
	/* note: doc appears to be reversed */
	if ( (o=stack[i>>>23]).toboolean() != ((i&(0x1ff<<14))!=0) )
	++pc;
	else
	stack[a] = o; // TODO: should be sBx?
	continue;

	case Lua.OP_CALL: /* A B C R(A), ... ,R(A+C-2):= R(A)(R(A+1), ... ,R(A+B-1)) */
	switch ( i & (Lua.MASK_B \| Lua.MASK_C) ) {
	case (1<<Lua.POS_B) \| (0<<Lua.POS_C): v=stack[a].invoke(NONE); top=a+v.narg(); continue;
	case (2<<Lua.POS_B) \| (0<<Lua.POS_C): v=stack[a].invoke(stack[a+1]); top=a+v.narg(); continue;
	case (1<<Lua.POS_B) \| (1<<Lua.POS_C): stack[a].call(); continue;
	case (2<<Lua.POS_B) \| (1<<Lua.POS_C): stack[a].call(stack[a+1]); continue;
	case (3<<Lua.POS_B) \| (1<<Lua.POS_C): stack[a].call(stack[a+1],stack[a+2]); continue;
	case (4<<Lua.POS_B) \| (1<<Lua.POS_C): stack[a].call(stack[a+1],stack[a+2],stack[a+3]); continue;
	case (1<<Lua.POS_B) \| (2<<Lua.POS_C): stack[a] = stack[a].call(); continue;
	case (2<<Lua.POS_B) \| (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1]); continue;
	case (3<<Lua.POS_B) \| (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1],stack[a+2]); continue;
	case (4<<Lua.POS_B) \| (2<<Lua.POS_C): stack[a] = stack[a].call(stack[a+1],stack[a+2],stack[a+3]); continue;
	default:
	b = i>>>23;
	c = (i>>14)&0x1ff;
	v = b>0?
	varargsOf(stack,a+1,b-1): // exact arg count
	varargsOf(stack, a+1, top-v.narg()-(a+1), v); // from prev top
	v = stack[a].invoke(v);
	if ( c > 0 ) {
	while ( --c > 0 )
	stack[a+c-1] = v.arg(c);
	v = NONE; // TODO: necessary?
	} else {
	top = a + v.narg();
	}
	continue;
	}

	case Lua.OP_TAILCALL: /* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */
	switch ( i & Lua.MASK_B ) {
	case (1<<Lua.POS_B): return new TailcallVarargs(stack[a], NONE);
	case (2<<Lua.POS_B): return new TailcallVarargs(stack[a], stack[a+1]);
	case (3<<Lua.POS_B): return new TailcallVarargs(stack[a], varargsOf(stack[a+1],stack[a+2]));
	case (4<<Lua.POS_B): return new TailcallVarargs(stack[a], varargsOf(stack[a+1],stack[a+2],stack[a+3]));
	default:
	b = i>>>23;
	v = b>0?
	varargsOf(stack,a+1,b-1): // exact arg count
	varargsOf(stack, a+1, top-v.narg()-(a+1), v); // from prev top
	return new TailcallVarargs( stack[a], v );
	}

	case Lua.OP_RETURN: /* A B return R(A), ... ,R(A+B-2) (see note) */
	b = i>>>23;
	switch ( b ) {
	case 0: return varargsOf(stack, a, top-v.narg()-a, v);
	case 1: return NONE;
	case 2: return stack[a];
	default:
	return varargsOf(stack, a, b-1);
	}

	case Lua.OP_FORLOOP: /* A sBx R(A)+=R(A+2): if R(A) <?= R(A+1) then { pc+=sBx: R(A+3)=R(A) }*/
	{
	LuaValue limit = stack[a + 1];
	LuaValue step = stack[a + 2];
	LuaValue idx = step.add(stack[a]);
	if (step.gt_b(0)? idx.lteq_b(limit): idx.gteq_b(limit)) {
	stack[a] = idx;
	stack[a + 3] = idx;
	pc += (i>>>14)-0x1ffff;
	}
	}
	continue;

	case Lua.OP_FORPREP: /* A sBx R(A)-=R(A+2): pc+=sBx */
	{
	LuaValue init = stack[a].checknumber("'for' initial value must be a number");
	LuaValue limit = stack[a + 1].checknumber("'for' limit must be a number");
	LuaValue step = stack[a + 2].checknumber("'for' step must be a number");
	stack[a] = init.sub(step);
	stack[a + 1] = limit;
	stack[a + 2] = step;
	pc += (i>>>14)-0x1ffff;
	}
	continue;

	case Lua.OP_TFORCALL: /* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); */
	v = stack[a].invoke(varargsOf(stack[a+1],stack[a+2]));
	c = (i>>14) & 0x1ff;
	while (--c >= 0)
	stack[a+3+c] = v.arg(c+1);
	v = NONE;
	continue;

	case Lua.OP_TFORLOOP: /* A sBx if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx */
	if (!stack[a+1].isnil()) { /* continue loop? */
	stack[a] = stack[a+1]; /* save control varible. */
	pc += (i>>>14)-0x1ffff;
	}
	continue;

	case Lua.OP_SETLIST: /* A B C R(A)[(C-1)FPF+i]:= R(A+i), 1 <= i <= B /
	{
	if ( (c=(i>>14)&0x1ff) == 0 )
	c = code[pc++];
	int offset = (c-1) * Lua.LFIELDS_PER_FLUSH;
	o = stack[a];
	if ( (b=i>>>23) == 0 ) {
	b = top - a - 1;
	int m = b - v.narg();
	int j=1;
	for ( ;j<=m; j++ )
	o.set(offset+j, stack[a + j]);
	for ( ;j<=b; j++ )
	o.set(offset+j, v.arg(j-m));
	} else {
	o.presize( offset + b );
	for (int j=1; j<=b; j++)
	o.set(offset+j, stack[a + j]);
	}
	}
	continue;

	case Lua.OP_CLOSURE: /* A Bx R(A):= closure(KPROTO[Bx]) */
	{
	Prototype newp = p.p[i>>>14];
	LuaClosure ncl = new LuaClosure(newp, globals);
	Upvaldesc[] uv = newp.upvalues;
	for ( int j=0, nup=uv.length; j<nup; ++j ) {
	if (uv[j].instack) /* upvalue refes to local variable? */
	ncl.upValues[j] = findupval(stack, uv[j].idx, openups);
	else /* get upvalue from enclosing function */
	ncl.upValues[j] = upValues[uv[j].idx];
	}
	stack[a] = ncl;
	}
	continue;

	case Lua.OP_VARARG: /* A B R(A), R(A+1), ..., R(A+B-1) = vararg */
	b = i>>>23;
	if ( b == 0 ) {
	top = a + (b = varargs.narg());
	v = varargs;
	} else {
	for ( int j=1; j<b; ++j )
	stack[a+j-1] = varargs.arg(j);
	}
	continue;

	case Lua.OP_EXTRAARG:
	throw new java.lang.IllegalArgumentException("Uexecutable opcode: OP_EXTRAARG");

	default:
	throw new java.lang.IllegalArgumentException("Illegal opcode: " + (i & 0x3f));
	}
	}
	} catch ( LuaError le ) {
	if (le.traceback == null)
	processErrorHooks(le, p, pc);
	throw le;
	} catch ( Exception e ) {
	LuaError le = new LuaError(e);
	processErrorHooks(le, p, pc);
	throw le;
	} finally {
	if ( openups != null )
	for ( int u=openups.length; --u>=0; )
	if ( openups[u] != null )
	openups[u].close();
	if (globals != null && globals.debuglib != null)
	globals.debuglib.onReturn();
	}
	}

	/**
	* Run the error hook if there is one
	* @param msg the message to use in error hook processing.
	* */
	String errorHook(String msg, int level) {
	if (globals == null ) return msg;
	final LuaThread r = globals.running;
	if (r.errorfunc == null)
	return globals.debuglib != null?
	msg + "\n" + globals.debuglib.traceback(level):
	msg;
	final LuaValue e = r.errorfunc;
	r.errorfunc = null;
	try {
	return e.call( LuaValue.valueOf(msg) ).tojstring();
	} catch ( Throwable t ) {
	return "error in error handling";
	} finally {
	r.errorfunc = e;
	}
	}

	private void processErrorHooks(LuaError le, Prototype p, int pc) {
	le.fileline = (p.source != null? p.source.tojstring(): "?") + ":"
	+ (p.lineinfo != null && pc >= 0 && pc < p.lineinfo.length? String.valueOf(p.lineinfo[pc]): "?");
	le.traceback = errorHook(le.getMessage(), le.level);
	}

	private UpValue findupval(LuaValue[] stack, short idx, UpValue[] openups) {
	final int n = openups.length;
	for (int i = 0; i < n; ++i)
	if (openups[i] != null && openups[i].index == idx)
	return openups[i];
	for (int i = 0; i < n; ++i)
	if (openups[i] == null)
	return openups[i] = new UpValue(stack, idx);
	error("No space for upvalue");
	return null;
	}

	protected LuaValue getUpvalue(int i) {
	return upValues[i].getValue();
	}

	protected void setUpvalue(int i, LuaValue v) {
	upValues[i].setValue(v);
	}

	public String name() {
	return "<"+p.shortsource()+":"+p.linedefined+">";
	}


	}