org.luaj.vm2.Lua Java Examples

private void findUpvalues() {
	int[] code = prototype.code;
	int n = code.length;
	
	// propogate to inner prototypes
	String[] names = findInnerprotoNames();
	for ( int pc=0; pc<n; pc++ ) {
		if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_CLOSURE ) {
			int bx = Lua.GETARG_Bx(code[pc]);
			Prototype newp = prototype.p[bx];
			UpvalInfo[] newu = new UpvalInfo[newp.upvalues.length];
			String newname = name + "$" + names[bx];
			for ( int j=0; j<newp.upvalues.length; ++j ) {
				Upvaldesc u = newp.upvalues[j];
				newu[j] = u.instack? findOpenUp(pc,u.idx) : upvals[u.idx];
			}
			subprotos[bx] = new ProtoInfo(newp, newname, newu);
		}
	}
	
	// mark all upvalues that are written locally as read/write
	for ( int pc=0; pc<n; pc++ ) {
		if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_SETUPVAL )
			upvals[Lua.GETARG_B(code[pc])].rw = true;
	}
}
 

void recfield(ConsControl cc) {
	/* recfield -> (NAME | `['exp1`]') = exp1 */
	FuncState fs = this.fs;
	int reg = this.fs.freereg;
	expdesc key = new expdesc();
	expdesc val = new expdesc();
	int rkkey;
	if (this.t.token == TK_NAME) {
		fs.checklimit(cc.nh, MAX_INT, "items in a constructor");
		this.checkname(key);
	} else
		/* this.t.token == '[' */
		this.yindex(key);
	cc.nh++;
	this.checknext('=');
	rkkey = fs.exp2RK(key);
	this.expr(val);
	fs.codeABC(Lua.OP_SETTABLE, cc.t.u.info, rkkey, fs.exp2RK(val));
	fs.freereg = (short)reg; /* free registers */
}
 

void check_conflict (LHS_assign lh, expdesc v) {
	FuncState fs = this.fs;
	short extra = (short) fs.freereg;  /* eventual position to save local variable */
	boolean conflict = false;
	for (; lh!=null; lh = lh.prev) {
		if (lh.v.k == VINDEXED) {
			/* table is the upvalue/local being assigned now? */
			if (lh.v.u.ind_vt == v.k && lh.v.u.ind_t == v.u.info) {
				conflict = true;
				lh.v.u.ind_vt = VLOCAL;
				lh.v.u.ind_t = extra;  /* previous assignment will use safe copy */
			}
			/* index is the local being assigned? (index cannot be upvalue) */
			if (v.k == VLOCAL && lh.v.u.ind_idx == v.u.info) {
				conflict = true;
				lh.v.u.ind_idx = extra;  /* previous assignment will use safe copy */
			}
		}
	}
	if (conflict) {
	    /* copy upvalue/local value to a temporary (in position 'extra') */
	    int op = (v.k == VLOCAL) ? Lua.OP_MOVE : Lua.OP_GETUPVAL;
	    fs.codeABC(op, extra, v.u.info, 0);
	    fs.reserveregs(1);
	}
}
 

void forbody(int base, int line, int nvars, boolean isnum) {
	/* forbody -> DO block */
	BlockCnt bl = new BlockCnt();
	FuncState fs = this.fs;
	int prep, endfor;
	this.adjustlocalvars(3); /* control variables */
	this.checknext(TK_DO);
	prep = isnum ? fs.codeAsBx(Lua.OP_FORPREP, base, NO_JUMP) : fs.jump();
	fs.enterblock(bl, false); /* scope for declared variables */
	this.adjustlocalvars(nvars);
	fs.reserveregs(nvars);
	this.block();
	fs.leaveblock(); /* end of scope for declared variables */
	fs.patchtohere(prep);
	if (isnum)  /* numeric for? */
		endfor = fs.codeAsBx(Lua.OP_FORLOOP, base, NO_JUMP);
	else {  /* generic for */
		fs.codeABC(Lua.OP_TFORCALL, base, 0, nvars);
		fs.fixline(line);
		endfor = fs.codeAsBx(Lua.OP_TFORLOOP, base + 2, NO_JUMP);
	}
	fs.patchlist(endfor, prep + 1);
	fs.fixline(line);
}
 

void fornum(LuaString varname, int line) {
	/* fornum -> NAME = exp1,exp1[,exp1] forbody */
	FuncState fs = this.fs;
	int base = fs.freereg;
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_INDEX);
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_LIMIT);
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_STEP);
	this.new_localvar(varname);
	this.checknext('=');
	this.exp1(); /* initial value */
	this.checknext(',');
	this.exp1(); /* limit */
	if (this.testnext(','))
		this.exp1(); /* optional step */
	else { /* default step = 1 */
		fs.codeABx(Lua.OP_LOADK, fs.freereg, fs.numberK(LuaInteger.valueOf(1)));
		fs.reserveregs(1);
	}
	this.forbody(base, line, 1, true);
}
 

void fornum(LuaString varname, int line) {
	/* fornum -> NAME = exp1,exp1[,exp1] forbody */
	FuncState fs = this.fs;
	int base = fs.freereg;
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_INDEX);
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_LIMIT);
	this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_STEP);
	this.new_localvar(varname);
	this.checknext('=');
	this.exp1(); /* initial value */
	this.checknext(',');
	this.exp1(); /* limit */
	if (this.testnext(','))
		this.exp1(); /* optional step */
	else { /* default step = 1 */
		fs.codeABx(Lua.OP_LOADK, fs.freereg, fs.numberK(LuaInteger.valueOf(1)));
		fs.reserveregs(1);
	}
	this.forbody(base, line, 1, true);
}
 

private void findUpvalues() {
	int[] code = prototype.code;
	int n = code.length;
	
	// propogate to inner prototypes
	String[] names = findInnerprotoNames();
	for ( int pc=0; pc<n; pc++ ) {
		if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_CLOSURE ) {
			int bx = Lua.GETARG_Bx(code[pc]);
			Prototype newp = prototype.p[bx];
			UpvalInfo[] newu = new UpvalInfo[newp.upvalues.length];
			String newname = name + "$" + names[bx];
			for ( int j=0; j<newp.upvalues.length; ++j ) {
				Upvaldesc u = newp.upvalues[j];
				newu[j] = u.instack? findOpenUp(pc,u.idx) : upvals[u.idx];
			}
			subprotos[bx] = new ProtoInfo(newp, newname, newu);
		}
	}
	
	// mark all upvalues that are written locally as read/write
	for ( int pc=0; pc<n; pc++ ) {
		if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_SETUPVAL )
			upvals[Lua.GETARG_B(code[pc])].rw = true;
	}
}
 

void fornum(LuaString varname, int line) {
/* fornum -> NAME = exp1,exp1[,exp1] forbody */
      FuncState fs = this.fs;
      int base = fs.freereg;
      this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_INDEX);
      this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_LIMIT);
      this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_STEP);
      this.new_localvar(varname);
      this.checknext('=');
      this.exp1(); /* initial value */
      this.checknext(',');
      this.exp1(); /* limit */
      if (this.testnext(','))
          this.exp1(); /* optional step */
      else { /* default step = 1 */
          fs.codeABx(Lua.OP_LOADK, fs.freereg, fs.numberK(LuaInteger.valueOf(1)));
          fs.reserveregs(1);
      }
      this.forbody(base, line, 1, true);
  }
 

void forbody(int base, int line, int nvars, boolean isnum) {
/* forbody -> DO block */
      BlockCnt bl = new BlockCnt();
      FuncState fs = this.fs;
      int prep, endfor;
      this.adjustlocalvars(3); /* control variables */
      this.checknext(TK_DO);
      prep = isnum ? fs.codeAsBx(Lua.OP_FORPREP, base, NO_JUMP) : fs.jump();
      fs.enterblock(bl, false); /* scope for declared variables */
      this.adjustlocalvars(nvars);
      fs.reserveregs(nvars);
      this.block();
      fs.leaveblock(); /* end of scope for declared variables */
      fs.patchtohere(prep);
      if (isnum)  /* numeric for? */
          endfor = fs.codeAsBx(Lua.OP_FORLOOP, base, NO_JUMP);
      else {  /* generic for */
          fs.codeABC(Lua.OP_TFORCALL, base, 0, nvars);
          fs.fixline(line);
          endfor = fs.codeAsBx(Lua.OP_TFORLOOP, base + 2, NO_JUMP);
      }
      fs.patchlist(endfor, prep + 1);
      fs.fixline(line);
  }
 

void check_conflict(LHS_assign lh, expdesc v) {
    FuncState fs = this.fs;
    short extra = (short) fs.freereg;  /* eventual position to save local variable */
    boolean conflict = false;
    for (; lh != null; lh = lh.prev) {
        if (lh.v.k == VINDEXED) {
/* table is the upvalue/local being assigned now? */
            if (lh.v.u.ind_vt == v.k && lh.v.u.ind_t == v.u.info) {
                conflict = true;
                lh.v.u.ind_vt = VLOCAL;
                lh.v.u.ind_t = extra;  /* previous assignment will use safe copy */
            }
/* index is the local being assigned? (index cannot be upvalue) */
            if (v.k == VLOCAL && lh.v.u.ind_idx == v.u.info) {
                conflict = true;
                lh.v.u.ind_idx = extra;  /* previous assignment will use safe copy */
            }
        }
    }
    if (conflict) {
  /* copy upvalue/local value to a temporary (in position 'extra') */
        int op = (v.k == VLOCAL) ? Lua.OP_MOVE : Lua.OP_GETUPVAL;
        fs.codeABC(op, extra, v.u.info, 0);
        fs.reserveregs(1);
    }
}
 

void forbody(int base, int line, int nvars, boolean isnum) {
	/* forbody -> DO block */
	BlockCnt bl = new BlockCnt();
	FuncState fs = this.fs;
	int prep, endfor;
	this.adjustlocalvars(3); /* control variables */
	this.checknext(TK_DO);
	prep = isnum ? fs.codeAsBx(Lua.OP_FORPREP, base, NO_JUMP) : fs.jump();
	fs.enterblock(bl, false); /* scope for declared variables */
	this.adjustlocalvars(nvars);
	fs.reserveregs(nvars);
	this.block();
	fs.leaveblock(); /* end of scope for declared variables */
	fs.patchtohere(prep);
	if (isnum)  /* numeric for? */
		endfor = fs.codeAsBx(Lua.OP_FORLOOP, base, NO_JUMP);
	else {  /* generic for */
		fs.codeABC(Lua.OP_TFORCALL, base, 0, nvars);
		fs.fixline(line);
		endfor = fs.codeAsBx(Lua.OP_TFORLOOP, base + 2, NO_JUMP);
	}
	fs.patchlist(endfor, prep + 1);
	fs.fixline(line);
}
 

void recfield(ConsControl cc) {
	/* recfield -> (NAME | `['exp1`]') = exp1 */
	FuncState fs = this.fs;
	int reg = this.fs.freereg;
	expdesc key = new expdesc();
	expdesc val = new expdesc();
	int rkkey;
	if (this.t.token == TK_NAME) {
		fs.checklimit(cc.nh, MAX_INT, "items in a constructor");
		this.checkname(key);
	} else
		/* this.t.token == '[' */
		this.yindex(key);
	cc.nh++;
	this.checknext('=');
	rkkey = fs.exp2RK(key);
	this.expr(val);
	fs.codeABC(Lua.OP_SETTABLE, cc.t.u.info, rkkey, fs.exp2RK(val));
	fs.freereg = (short)reg; /* free registers */
}
 

void recfield(ConsControl cc) {
/* recfield -> (NAME | `['exp1`]') = exp1 */
      FuncState fs = this.fs;
      int reg = this.fs.freereg;
      expdesc key = new expdesc();
      expdesc val = new expdesc();
      int rkkey;
      if (this.t.token == TK_NAME) {
          fs.checklimit(cc.nh, MAX_INT, "items in a constructor");
          this.checkname(key);
      } else
	/* this.t.token == '[' */
          this.yindex(key);
      cc.nh++;
      this.checknext('=');
      rkkey = fs.exp2RK(key);
      this.expr(val);
      fs.codeABC(Lua.OP_SETTABLE, cc.t.u.info, rkkey, fs.exp2RK(val));
      fs.freereg = (short) reg; /* free registers */
  }
 

void check_conflict (LHS_assign lh, expdesc v) {
	FuncState fs = this.fs;
	short extra = (short) fs.freereg;  /* eventual position to save local variable */
	boolean conflict = false;
	for (; lh!=null; lh = lh.prev) {
		if (lh.v.k == VINDEXED) {
			/* table is the upvalue/local being assigned now? */
			if (lh.v.u.ind_vt == v.k && lh.v.u.ind_t == v.u.info) {
				conflict = true;
				lh.v.u.ind_vt = VLOCAL;
				lh.v.u.ind_t = extra;  /* previous assignment will use safe copy */
			}
			/* index is the local being assigned? (index cannot be upvalue) */
			if (v.k == VLOCAL && lh.v.u.ind_idx == v.u.info) {
				conflict = true;
				lh.v.u.ind_idx = extra;  /* previous assignment will use safe copy */
			}
		}
	}
	if (conflict) {
	    /* copy upvalue/local value to a temporary (in position 'extra') */
	    int op = (v.k == VLOCAL) ? Lua.OP_MOVE : Lua.OP_GETUPVAL;
	    fs.codeABC(op, extra, v.u.info, 0);
	    fs.reserveregs(1);
	}
}
 

void recfield(ConsControl cc) {
	/* recfield -> (NAME | `['exp1`]') = exp1 */
	FuncState fs = this.fs;
	int reg = this.fs.freereg;
	expdesc key = new expdesc();
	expdesc val = new expdesc();
	int rkkey;
	if (this.t.token == TK_NAME) {
		fs.checklimit(cc.nh, MAX_INT, "items in a constructor");
		this.checkname(key);
	} else
		/* this.t.token == '[' */
		this.yindex(key);
	cc.nh++;
	this.checknext('=');
	rkkey = fs.exp2RK(key);
	this.expr(val);
	fs.codeABC(Lua.OP_SETTABLE, cc.t.u.info, rkkey, fs.exp2RK(val));
	fs.freereg = (short)reg; /* free registers */
}
 

void check_conflict (LHS_assign lh, expdesc v) {
	FuncState fs = this.fs;
	short extra = (short) fs.freereg;  /* eventual position to save local variable */
	boolean conflict = false;
	for (; lh!=null; lh = lh.prev) {
		if (lh.v.k == VINDEXED) {
			/* table is the upvalue/local being assigned now? */
			if (lh.v.u.ind_vt == v.k && lh.v.u.ind_t == v.u.info) {
				conflict = true;
				lh.v.u.ind_vt = VLOCAL;
				lh.v.u.ind_t = extra;  /* previous assignment will use safe copy */
			}
			/* index is the local being assigned? (index cannot be upvalue) */
			if (v.k == VLOCAL && lh.v.u.ind_idx == v.u.info) {
				conflict = true;
				lh.v.u.ind_idx = extra;  /* previous assignment will use safe copy */
			}
		}
	}
	if (conflict) {
	    /* copy upvalue/local value to a temporary (in position 'extra') */
	    int op = (v.k == VLOCAL) ? Lua.OP_MOVE : Lua.OP_GETUPVAL;
	    fs.codeABC(op, extra, v.u.info, 0);
	    fs.reserveregs(1);
	}
}
 

void forbody(int base, int line, int nvars, boolean isnum) {
	/* forbody -> DO block */
	BlockCnt bl = new BlockCnt();
	FuncState fs = this.fs;
	int prep, endfor;
	this.adjustlocalvars(3); /* control variables */
	this.checknext(TK_DO);
	prep = isnum ? fs.codeAsBx(Lua.OP_FORPREP, base, NO_JUMP) : fs.jump();
	fs.enterblock(bl, false); /* scope for declared variables */
	this.adjustlocalvars(nvars);
	fs.reserveregs(nvars);
	this.block();
	fs.leaveblock(); /* end of scope for declared variables */
	fs.patchtohere(prep);
	if (isnum)  /* numeric for? */
		endfor = fs.codeAsBx(Lua.OP_FORLOOP, base, NO_JUMP);
	else {  /* generic for */
		fs.codeABC(Lua.OP_TFORCALL, base, 0, nvars);
		fs.fixline(line);
		endfor = fs.codeAsBx(Lua.OP_TFORLOOP, base + 2, NO_JUMP);
	}
	fs.patchlist(endfor, prep + 1);
	fs.fixline(line);
}
 

boolean patchtestreg(int node, int reg) {
	InstructionPtr i = this.getjumpcontrol(node);
	if (GET_OPCODE(i.get()) != OP_TESTSET)
		/* cannot patch other instructions */
		return false;
	if (reg != NO_REG && reg != GETARG_B(i.get()))
		SETARG_A(i, reg);
	else
		/* no register to put value or register already has the value */
		i.set(CREATE_ABC(OP_TEST, GETARG_B(i.get()), 0, Lua.GETARG_C(i.get())));

	return true;
}
 

static NameWhat getfuncname(DebugLib.CallFrame frame) {
	if (!frame.f.isclosure())
		return new NameWhat(frame.f.classnamestub(), "Java");
	Prototype p = frame.f.checkclosure().p;
	int pc = frame.pc;
	int i = p.code[pc]; /* calling instruction */
	LuaString tm;
	switch (Lua.GET_OPCODE(i)) {
		case Lua.OP_CALL:
		case Lua.OP_TAILCALL: /* get function name */
			return getobjname(p, pc, Lua.GETARG_A(i));
		case Lua.OP_TFORCALL: /* for iterator */
	    	return new NameWhat("(for iterator)", "(for iterator");
	    /* all other instructions can call only through metamethods */
	    case Lua.OP_SELF:
	    case Lua.OP_GETTABUP:
	    case Lua.OP_GETTABLE: tm = LuaValue.INDEX; break;
	    case Lua.OP_SETTABUP:
	    case Lua.OP_SETTABLE: tm = LuaValue.NEWINDEX; break;
	    case Lua.OP_EQ: tm = LuaValue.EQ; break;
	    case Lua.OP_ADD: tm = LuaValue.ADD; break;
	    case Lua.OP_SUB: tm = LuaValue.SUB; break;
	    case Lua.OP_MUL: tm = LuaValue.MUL; break;
	    case Lua.OP_DIV: tm = LuaValue.DIV; break;
	    case Lua.OP_MOD: tm = LuaValue.MOD; break;
	    case Lua.OP_POW: tm = LuaValue.POW; break;
	    case Lua.OP_UNM: tm = LuaValue.UNM; break;
	    case Lua.OP_LEN: tm = LuaValue.LEN; break;
	    case Lua.OP_LT: tm = LuaValue.LT; break;
	    case Lua.OP_LE: tm = LuaValue.LE; break;
	    case Lua.OP_CONCAT: tm = LuaValue.CONCAT; break;
	    default:
	      return null;  /* else no useful name can be found */
	}
	return new NameWhat( tm.tojstring(), "metamethod" );
}
 

void lexerror( String msg, int token ) {
	String cid = Lua.chunkid( source.tojstring() );
	L.pushfstring( cid+":"+linenumber+": "+msg );
	if ( token != 0 )
		L.pushfstring( "syntax error: "+msg+" near "+txtToken(token) );
	throw new LuaError(cid+":"+linenumber+": "+msg);
}
 

/** Perform one-time initialization on the library by adding base functions
 * to the supplied environment, and returning it as the return value.
 * @param modname the module name supplied if this is loaded via 'require'.
 * @param env the environment to load into, which must be a Globals instance.
 */
public LuaValue call(LuaValue modname, LuaValue env) {
	globals = env.checkglobals();
	globals.finder = this;
	globals.baselib = this;
	env.set( "_G", env );
	env.set( "_VERSION", Lua._VERSION );
	env.set("assert", new _assert());
	env.set("collectgarbage", new collectgarbage());
	env.set("dofile", new dofile());
	env.set("error", new error());
	env.set("getmetatable", new getmetatable());
	env.set("load", new load());
	env.set("loadfile", new loadfile());
	env.set("pcall", new pcall());
	env.set("print", new print(this));
	env.set("rawequal", new rawequal());
	env.set("rawget", new rawget());
	env.set("rawlen", new rawlen());
	env.set("rawset", new rawset());
	env.set("select", new select());
	env.set("setmetatable", new setmetatable());
	env.set("tonumber", new tonumber());
	env.set("tostring", new tostring());
	env.set("type", new type());
	env.set("xpcall", new xpcall());

	next next;
	env.set("next", next = new next());
	env.set("pairs", new pairs(next));
	env.set("ipairs", new ipairs());
	
	return env;
}
 

static String kname(Prototype p, int pc, int c) {
	if (Lua.ISK(c)) {  /* is 'c' a constant? */
		LuaValue k = p.k[Lua.INDEXK(c)];
		if (k.isstring()) {  /* literal constant? */
			return k.tojstring();  /* it is its own name */
		} /* else no reasonable name found */
	} else {  /* 'c' is a register */
		NameWhat what = getobjname(p, pc, c); /* search for 'c' */
	    if (what != null && "constant".equals(what.namewhat)) {  /* found a constant name? */
	      return what.name;  /* 'name' already filled */
	    }
	    /* else no reasonable name found */
	}
	return "?";  /* no reasonable name found */
}
 

void retstat() {
	/* stat -> RETURN explist */
	FuncState fs = this.fs;
	expdesc e = new expdesc();
	int first, nret; /* registers with returned values */
	if (block_follow(true) || this.t.token == ';')
		first = nret = 0; /* return no values */
	else {
		nret = this.explist(e); /* optional return values */
		if (hasmultret(e.k)) {
			fs.setmultret(e);
			if (e.k == VCALL && nret == 1) { /* tail call? */
				SET_OPCODE(fs.getcodePtr(e), Lua.OP_TAILCALL);
				_assert (Lua.GETARG_A(fs.getcode(e)) == fs.nactvar);
			}
			first = fs.nactvar;
			nret = Lua.LUA_MULTRET; /* return all values */
		} else {
			if (nret == 1) /* only one single value? */
				first = fs.exp2anyreg(e);
			else {
				fs.exp2nextreg(e); /* values must go to the `stack' */
				first = fs.nactvar; /* return all `active' values */
				_assert (nret == fs.freereg - first);
			}
		}
	}
	fs.ret(first, nret);
	testnext(';');  /* skip optional semicolon */
}
 

public void binaryop(int o) {
	String op;
	switch (o) {
		default: 
		case Lua.OP_ADD: op = "add"; break;
		case Lua.OP_SUB: op = "sub"; break;
		case Lua.OP_MUL: op = "mul"; break;
		case Lua.OP_DIV: op = "div"; break;
		case Lua.OP_MOD: op = "mod"; break;
		case Lua.OP_POW: op = "pow"; break;
	}
       append(factory.createInvoke(STR_LUAVALUE, op, TYPE_LUAVALUE, ARG_TYPES_LUAVALUE, Constants.INVOKEVIRTUAL));
}
 

void invertjump(expdesc e) {
	InstructionPtr pc = this.getjumpcontrol(e.u.info);
	_assert (testTMode(GET_OPCODE(pc.get()))
			&& GET_OPCODE(pc.get()) != OP_TESTSET && Lua
			.GET_OPCODE(pc.get()) != OP_TEST);
	// SETARG_A(pc, !(GETARG_A(pc.get())));
	int a = GETARG_A(pc.get());
	int nota = (a!=0? 0: 1);
	SETARG_A(pc, nota);
}
 

boolean patchtestreg(int node, int reg) {
	InstructionPtr i = this.getjumpcontrol(node);
	if (GET_OPCODE(i.get()) != OP_TESTSET)
		/* cannot patch other instructions */
		return false;
	if (reg != NO_REG && reg != GETARG_B(i.get()))
		SETARG_A(i, reg);
	else
		/* no register to put value or register already has the value */
		i.set(CREATE_ABC(OP_TEST, GETARG_B(i.get()), 0, Lua.GETARG_C(i.get())));

	return true;
}
 

void retstat() {
	/* stat -> RETURN explist */
	FuncState fs = this.fs;
	expdesc e = new expdesc();
	int first, nret; /* registers with returned values */
	if (block_follow(true) || this.t.token == ';')
		first = nret = 0; /* return no values */
	else {
		nret = this.explist(e); /* optional return values */
		if (hasmultret(e.k)) {
			fs.setmultret(e);
			if (e.k == VCALL && nret == 1) { /* tail call? */
				SET_OPCODE(fs.getcodePtr(e), Lua.OP_TAILCALL);
				_assert (Lua.GETARG_A(fs.getcode(e)) == fs.nactvar);
			}
			first = fs.nactvar;
			nret = Lua.LUA_MULTRET; /* return all values */
		} else {
			if (nret == 1) /* only one single value? */
				first = fs.exp2anyreg(e);
			else {
				fs.exp2nextreg(e); /* values must go to the `stack' */
				first = fs.nactvar; /* return all `active' values */
				_assert (nret == fs.freereg - first);
			}
		}
	}
	fs.ret(first, nret);
	testnext(';');  /* skip optional semicolon */
}
 

static NameWhat getfuncname(DebugLib.CallFrame frame) {
	if (!frame.f.isclosure())
		return new NameWhat(frame.f.classnamestub(), "Java");
	Prototype p = frame.f.checkclosure().p;
	int pc = frame.pc;
	int i = p.code[pc]; /* calling instruction */
	LuaString tm;
	switch (Lua.GET_OPCODE(i)) {
		case Lua.OP_CALL:
		case Lua.OP_TAILCALL: /* get function name */
			return getobjname(p, pc, Lua.GETARG_A(i));
		case Lua.OP_TFORCALL: /* for iterator */
	    	return new NameWhat("(for iterator)", "(for iterator");
	    /* all other instructions can call only through metamethods */
	    case Lua.OP_SELF:
	    case Lua.OP_GETTABUP:
	    case Lua.OP_GETTABLE: tm = LuaValue.INDEX; break;
	    case Lua.OP_SETTABUP:
	    case Lua.OP_SETTABLE: tm = LuaValue.NEWINDEX; break;
	    case Lua.OP_EQ: tm = LuaValue.EQ; break;
	    case Lua.OP_ADD: tm = LuaValue.ADD; break;
	    case Lua.OP_SUB: tm = LuaValue.SUB; break;
	    case Lua.OP_MUL: tm = LuaValue.MUL; break;
	    case Lua.OP_DIV: tm = LuaValue.DIV; break;
	    case Lua.OP_MOD: tm = LuaValue.MOD; break;
	    case Lua.OP_POW: tm = LuaValue.POW; break;
	    case Lua.OP_UNM: tm = LuaValue.UNM; break;
	    case Lua.OP_LEN: tm = LuaValue.LEN; break;
	    case Lua.OP_LT: tm = LuaValue.LT; break;
	    case Lua.OP_LE: tm = LuaValue.LE; break;
	    case Lua.OP_CONCAT: tm = LuaValue.CONCAT; break;
	    default:
	      return null;  /* else no useful name can be found */
	}
	return new NameWhat( tm.tojstring(), "metamethod" );
}
 

/**
 * Perform one-time initialization on the library by adding base functions
 * to the supplied environment, and returning it as the return value.
 *
 * @param modname the module name supplied if this is loaded via 'require'.
 * @param env     the environment to load into, which must be a Globals instance.
 */
public LuaValue call(LuaValue modname, LuaValue env) {
    globals = env.checkglobals();
    globals.finder = this;
    globals.baselib = this;
    env.set("_G", env);
    env.set("_VERSION", Lua._VERSION);
    env.set("assert", new _assert());
    env.set("collectgarbage", new collectgarbage());
    env.set("dofile", new dofile());
    env.set("error", new error());
    env.set("getmetatable", new getmetatable());
    env.set("load", new load());
    env.set("loadfile", new loadfile());
    env.set("pcall", new pcall());
    env.set("print", new print(this));
    env.set("rawequal", new rawequal());
    env.set("rawget", new rawget());
    env.set("rawlen", new rawlen());
    env.set("rawset", new rawset());
    env.set("select", new select());
    env.set("setmetatable", new setmetatable());
    env.set("tonumber", new tonumber());
    env.set("tostring", new tostring());
    env.set("type", new type());
    env.set("xpcall", new xpcall());

    next next;
    env.set("next", next = new next());
    env.set("pairs", new pairs(next));
    env.set("ipairs", new ipairs());

    return env;
}
 

void lexerror( String msg, int token ) {
	String cid = Lua.chunkid( source.tojstring() );
	L.pushfstring( cid+":"+linenumber+": "+msg );
	if ( token != 0 )
		L.pushfstring( "syntax error: "+msg+" near "+txtToken(token) );
	throw new LuaError(cid+":"+linenumber+": "+msg);
}