org.luaj.vm2.lib
Class DebugLib

java.lang.Object
  org.luaj.vm2.Varargs
      org.luaj.vm2.LuaValue
          org.luaj.vm2.LuaFunction
              org.luaj.vm2.lib.LibFunction
                  org.luaj.vm2.lib.TwoArgFunction
                      org.luaj.vm2.lib.DebugLib

public class DebugLib
extends TwoArgFunction

Subclass of LibFunction which implements the lua standard debug library.

The debug library in luaj tries to emulate the behavior of the corresponding C-based lua library. To do this, it must maintain a separate stack of calls to LuaClosure and LibFunction instances. Especially when lua-to-java bytecode compiling is being used via a Globals.Compiler such as LuaJC, this cannot be done in all cases.

Typically, this library is included as part of a call to either JsePlatform.debugGlobals() or JmePlatform.debugGlobals()

 Globals globals = JsePlatform.debugGlobals();
 System.out.println( globals.get("debug").get("traceback").call() );
  

To instantiate and use it directly, link it into your globals table via LuaValue.load(LuaValue) using code such as:

 Globals globals = new Globals();
 globals.load(new JseBaseLib());
 globals.load(new PackageLib());
 globals.load(new DebugLib());
 System.out.println( globals.get("debug").get("traceback").call() );
  

This library exposes the entire state of lua code, and provides method to see and modify all underlying lua values within a Java VM so should not be exposed to client code in a shared server environment.

See Also:

LibFunction, JsePlatform, JmePlatform, Lua 5.2 Debug Lib Reference

Nested Class Summary

static class

DebugLib.CallStack

Field Summary

static boolean	CALLS
static boolean	TRACE

Fields inherited from class org.luaj.vm2.lib.LibFunction

name, opcode

Fields inherited from class org.luaj.vm2.LuaFunction

s_metatable

Fields inherited from class org.luaj.vm2.LuaValue

ADD, CONCAT, DIV, EMPTYSTRING, ENV, EQ, FALSE, INDEX, LE, LEN, LT, METATABLE, MINUSONE, MOD, MODE, MUL, NEWINDEX, NIL, NILS, NONE, NOVALS, ONE, POW, SUB, TBOOLEAN, TFUNCTION, TINT, TLIGHTUSERDATA, TNIL, TNONE, TNUMBER, TOSTRING, TRUE, TSTRING, TTABLE, TTHREAD, TUSERDATA, TVALUE, TYPE_NAMES, UNM, ZERO

Constructor Summary

DebugLib()

Method Summary

LuaValue	call(LuaValue modname, LuaValue env) Perform one-time initialization on the library by creating a table containing the library functions, adding that table to the supplied environment, adding the table to package.loaded, and returning table as the return value.
static org.luaj.vm2.lib.DebugLib.NameWhat	getobjname(Prototype p, int lastpc, int reg)
void	onCall(LuaClosure c, Varargs varargs, LuaValue[] stack)
void	onCall(LuaFunction f)
void	onInstruction(int pc, Varargs v, int top)
void	onReturn()
java.lang.String	traceback(int level)

Methods inherited from class org.luaj.vm2.lib.TwoArgFunction

call, call, call, invoke

Methods inherited from class org.luaj.vm2.lib.LibFunction

bind, bind, call, newupe, newupl, newupn, tojstring

Methods inherited from class org.luaj.vm2.LuaFunction

checkfunction, classnamestub, getmetatable, isfunction, name, optfunction, strvalue, type, typename

Methods inherited from class org.luaj.vm2.LuaValue

add, add, add, and, arg, arg1, argerror, argerror, aritherror, aritherror, arithmt, arithmtwith, assert_, buffer, call, callmt, checkboolean, checkclosure, checkdouble, checkglobals, checkint, checkinteger, checkjstring, checklong, checkmetatag, checknotnil, checknumber, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, compareerror, compareerror, comparemt, concat, concat, concatmt, concatTo, concatTo, concatTo, div, div, div, divInto, eq_b, eq, eqmtcall, equals, error, get, get, get, gettable, gt_b, gt_b, gt_b, gt, gt, gt, gteq_b, gteq_b, gteq_b, gteq, gteq, gteq, illegal, inext, initupvalue1, invoke, invoke, invoke, invoke, invoke, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, isboolean, isclosure, isint, isinttype, islong, isnil, isnumber, isstring, istable, isthread, isuserdata, isuserdata, isvalidkey, len, lenerror, length, listOf, listOf, load, lt_b, lt_b, lt_b, lt, lt, lt, lteq_b, lteq_b, lteq_b, lteq, lteq, lteq, metatableOf, metatag, method, method, method, method, method, method, mod, mod, mod, modFrom, mul, mul, mul, narg, neg, neq_b, neq, next, not, onInvoke, optboolean, optclosure, optdouble, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, or, pow, pow, pow, powWith, powWith, presize, raweq, raweq, raweq, raweq, raweq, rawget, rawget, rawget, rawlen, rawset, rawset, rawset, rawset, rawset, rawset, rawset, rawsetlist, set, set, set, set, set, set, set, setmetatable, settable, strcmp, strcmp, strongvalue, sub, sub, sub, subargs, subFrom, subFrom, tableOf, tableOf, tableOf, tableOf, tableOf, tableOf, tailcallOf, testfor_b, toboolean, tobyte, tochar, todouble, tofloat, toint, tolong, tonumber, toshort, tostring, toString, touserdata, touserdata, typerror, unimplemented, userdataOf, userdataOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf

Methods inherited from class org.luaj.vm2.Varargs

argcheck, checkboolean, checkclosure, checkdouble, checkfunction, checkint, checkinteger, checkjstring, checklong, checknotnil, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, checkvalue, eval, isfunction, isnil, isnoneornil, isnumber, isstring, istable, isTailcall, isthread, isuserdata, isvalue, optboolean, optclosure, optdouble, optfunction, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, toboolean, tobyte, tochar, todouble, tofloat, toint, tojstring, tolong, toshort, touserdata, touserdata, type

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

CALLS

public static boolean CALLS

TRACE

public static boolean TRACE

Constructor Detail

DebugLib

public DebugLib()

Method Detail

call

public LuaValue call(LuaValue modname,
                     LuaValue env)

Perform one-time initialization on the library by creating a table containing the library functions, adding that table to the supplied environment, adding the table to package.loaded, and returning table as the return value.

Specified by:

call in class TwoArgFunction

Parameters:

modname - the module name supplied if this is loaded via 'require'.

env - the environment to load into, which must be a Globals instance.

Returns:

First return value (this(arg1,arg2)), or LuaValue.NIL if there were none.

See Also:

LuaValue.call(), LuaValue.call(LuaValue), LuaValue.call(LuaValue, LuaValue, LuaValue), LuaValue.invoke(LuaValue, Varargs), LuaValue.method(String,LuaValue,LuaValue), LuaValue.method(LuaValue,LuaValue,LuaValue)

onCall

public void onCall(LuaFunction f)

onCall

public void onCall(LuaClosure c,
                   Varargs varargs,
                   LuaValue[] stack)

onInstruction

public void onInstruction(int pc,
                          Varargs v,
                          int top)

onReturn

public void onReturn()

traceback

public java.lang.String traceback(int level)

getobjname

public static org.luaj.vm2.lib.DebugLib.NameWhat getobjname(Prototype p,
                                                            int lastpc,
                                                            int reg)