org.classdump.luna.lib

Class DebugLib

java.lang.Object

org.classdump.luna.lib.DebugLib

public final class DebugLib
extends Object

This library provides the functionality of the debug interface (see §4.9 of the Lua Reference Manual) to Lua programs. You should exert care when using this library. Several of its functions violate basic assumptions about Lua code (e.g., that variables local to a function cannot be accessed from outside; that userdata metatables cannot be changed by Lua code; that Lua programs do not crash) and therefore can compromise otherwise secure code. Moreover, some functions in this library may be slow.

All functions in this library are provided inside the debug table. All functions that operate over a thread have an optional first argument which is the thread to operate over. The default is always the current thread.

Method Summary

Modifier and Type	Method and Description
static org.classdump.luna.runtime.LuaFunction	getmetatable() Returns the function debug.getmetatable.
static org.classdump.luna.runtime.LuaFunction	getupvalue() Returns the function debug.getupvalue.
static org.classdump.luna.runtime.LuaFunction	getuservalue() Returns the function debug.getuservalue.
static void	installInto(org.classdump.luna.StateContext context, org.classdump.luna.Table env) Installs the debug library to the global environment env in the state context context.
static org.classdump.luna.runtime.LuaFunction	setmetatable() Returns the function debug.setmetatable.
static org.classdump.luna.runtime.LuaFunction	setupvalue() Returns the function debug.setupvalue.
static org.classdump.luna.runtime.LuaFunction	setuservalue() Returns the function debug.setuservalue.
static org.classdump.luna.runtime.LuaFunction	upvalueid() Returns the function debug.upvalueid.
static org.classdump.luna.runtime.LuaFunction	upvaluejoin() Returns the function debug.upvaluejoin.

Methods inherited from class java.lang.Object

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

Method Detail

getmetatable

public static org.classdump.luna.runtime.LuaFunction getmetatable()

Returns the function debug.getmetatable.

The following is the corresponding entry from the Lua Reference Manual:

debug.getmetatable (value)

Returns the metatable of the given value or nil if it does not have a metatable.

Returns:

the debug.getmetatable function

See Also:

the Lua 5.3 Reference Manual entry for debug.getmetatable

getupvalue

public static org.classdump.luna.runtime.LuaFunction getupvalue()

Returns the function debug.getupvalue.

The following is the corresponding entry from the Lua Reference Manual:

debug.getupvalue (f, up)

This function returns the name and the value of the upvalue with index up of the function f. The function returns nil if there is no upvalue with the given index.

Variable names starting with '(' (open parenthesis) represent variables with no known names (variables from chunks saved without debug information).

Returns:

the debug.getupvalue function

See Also:

the Lua 5.3 Reference Manual entry for debug.getupvalue

getuservalue

public static org.classdump.luna.runtime.LuaFunction getuservalue()

Returns the function debug.getuservalue.

The following is the corresponding entry from the Lua Reference Manual:

debug.getuservalue (u)

Returns the Lua value associated to u. If u is not a userdata, returns nil.

Returns:

the debug.getuservalue function

See Also:

the Lua 5.3 Reference Manual entry for debug.getuservalue

setmetatable

public static org.classdump.luna.runtime.LuaFunction setmetatable()

Returns the function debug.setmetatable.

The following is the corresponding entry from the Lua Reference Manual:

debug.setmetatable (value, table)

Sets the metatable for the given value to the given table (which can be nil). Returns value.

Returns:

the debug.setmetatable function

See Also:

the Lua 5.3 Reference Manual entry for debug.setmetatable

setupvalue

public static org.classdump.luna.runtime.LuaFunction setupvalue()

Returns the function debug.setupvalue.

The following is the corresponding entry from the Lua Reference Manual:

debug.setupvalue (f, up, value)

This function assigns the value value to the upvalue with index up of the function f. The function returns nil if there is no upvalue with the given index. Otherwise, it returns the name of the upvalue.

Returns:

the debug.setupvalue function

See Also:

the Lua 5.3 Reference Manual entry for debug.setupvalue

setuservalue

public static org.classdump.luna.runtime.LuaFunction setuservalue()

Returns the function debug.setuservalue.

The following is the corresponding entry from the Lua Reference Manual:

debug.setuservalue (udata, value)

Sets the given value as the Lua value associated to the given udata. udata must be a full userdata.

Returns udata.

Returns:

the debug.setuservalue function

See Also:

the Lua 5.3 Reference Manual entry for debug.setuservalue

upvalueid

public static org.classdump.luna.runtime.LuaFunction upvalueid()

Returns the function debug.upvalueid.

The following is the corresponding entry from the Lua Reference Manual:

debug.upvalueid (f, n)

Returns a unique identifier (as a light userdata) for the upvalue numbered n from the given function.

These unique identifiers allow a program to check whether different closures share upvalues. Lua closures that share an upvalue (that is, that access a same external local variable) will return identical ids for those upvalue indices.

Returns:

the debug.upvalueid function

See Also:

the Lua 5.3 Reference Manual entry for debug.upvalueid

upvaluejoin

public static org.classdump.luna.runtime.LuaFunction upvaluejoin()

Returns the function debug.upvaluejoin.

The following is the corresponding entry from the Lua Reference Manual:

debug.upvaluejoin (f1, n1, f2, n2)

Make the n1-th upvalue of the Lua closure f1 refer to the n2-th upvalue of the Lua closure f2.

Returns:

the debug.upvaluejoin function

See Also:

the Lua 5.3 Reference Manual entry for debug.upvaluejoin

installInto

public static void installInto(org.classdump.luna.StateContext context,
                               org.classdump.luna.Table env)

Installs the debug library to the global environment env in the state context context.

If env.package.loaded is a table, adds the library table to it with the key "debug", using raw access.

Parameters:

context - the state context, must not be null

env - the global environment, must not be null

Throws:

NullPointerException - if context or env is null