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/*******************************************************************************
* Copyright (c) 2009-2011 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.lib;
import org.luaj.vm2.Globals;
import org.luaj.vm2.Lua;
import org.luaj.vm2.LuaBoolean;
import org.luaj.vm2.LuaClosure;
import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaNil;
import org.luaj.vm2.LuaNumber;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaThread;
import org.luaj.vm2.LuaUserdata;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Print;
import org.luaj.vm2.Prototype;
import org.luaj.vm2.Varargs;
/**
* Subclass of {@link LibFunction} which implements the lua standard {@code 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 {@link LuaClosure} and {@link LibFunction}
* instances.
* Especially when lua-to-java bytecode compiling is being used
* via a {@link LuaCompiler} such as {@link LuaJC},
* this cannot be done in all cases.
*
* Typically, this library is included as part of a call to either
* {@link JsePlatform#debugGlobals()} or {@link JmePlatform#debugGlobals()}
*
{@code
* 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 {@link LuaValue#load(LuaValue)} using code such as:
*
{@code
* 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() );
* }
*
* @see LibFunction
* @see JsePlatform
* @see JmePlatform
* @see Lua 5.2 Debug Lib Reference
*/
public class DebugLib extends TwoArgFunction {
public static final boolean CALLS = (null != System.getProperty("CALLS"));
public static final boolean TRACE = (null != System.getProperty("TRACE"));
private static final LuaString LUA = valueOf("Lua");
private static final LuaString QMARK = valueOf("?");
private static final LuaString CALL = valueOf("call");
private static final LuaString LINE = valueOf("line");
private static final LuaString COUNT = valueOf("count");
private static final LuaString RETURN = valueOf("return");
private static final LuaString FUNC = valueOf("func");
private static final LuaString ISTAILCALL = valueOf("istailcall");
private static final LuaString ISVARARG = valueOf("isvararg");
private static final LuaString NUPS = valueOf("nups");
private static final LuaString NPARAMS = valueOf("nparams");
private static final LuaString NAME = valueOf("name");
private static final LuaString NAMEWHAT = valueOf("namewhat");
private static final LuaString WHAT = valueOf("what");
private static final LuaString SOURCE = valueOf("source");
private static final LuaString SHORT_SRC = valueOf("short_src");
private static final LuaString LINEDEFINED = valueOf("linedefined");
private static final LuaString LASTLINEDEFINED = valueOf("lastlinedefined");
private static final LuaString CURRENTLINE = valueOf("currentline");
private static final LuaString ACTIVELINES = valueOf("activelines");
Globals globals;
public LuaValue call(LuaValue modname, LuaValue env) {
globals = env.checkglobals();
globals.debuglib = this;
LuaTable debug = new LuaTable();
debug.set("debug", new debug());
debug.set("gethook", new gethook());
debug.set("getinfo", new getinfo());
debug.set("getlocal", new getlocal());
debug.set("getmetatable", new getmetatable());
debug.set("getregistry", new getregistry());
debug.set("getupvalue", new getupvalue());
debug.set("getuservalue", new getuservalue());
debug.set("sethook", new sethook());
debug.set("setlocal", new setlocal());
debug.set("setmetatable", new setmetatable());
debug.set("setupvalue", new setupvalue());
debug.set("setuservalue", new setuservalue());
debug.set("traceback", new traceback());
debug.set("upvalueid", new upvalueid());
debug.set("upvaluejoin", new upvaluejoin());
env.set("debug", debug);
env.get("package").get("loaded").set("debug", debug);
return debug;
}
// debug.debug()
static final class debug extends ZeroArgFunction {
public LuaValue call() {
return NONE;
}
}
// debug.gethook ([thread])
final class gethook extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaThread t = args.narg() > 0 ? args.checkthread(1): globals.running;
return varargsOf(
t.hookfunc != null? t.hookfunc: NIL,
valueOf((t.hookcall?"c":"")+(t.hookline?"l":"")+(t.hookrtrn?"r":"")),
valueOf(t.hookcount));
}
}
// debug.getinfo ([thread,] f [, what])
final class getinfo extends VarArgFunction {
public Varargs invoke(Varargs args) {
int a=1;
LuaThread thread = args.isthread(a)? args.checkthread(a++): globals.running;
LuaValue func = args.arg(a++);
String what = args.optjstring(a++, "flnStu");
DebugLib.CallStack callstack = callstack(thread);
// find the stack info
DebugLib.CallFrame frame;
if ( func.isnumber() ) {
frame = callstack.getCallFrame(func.toint());
if (frame == null)
return NONE;
func = frame.f;
} else if ( func.isfunction() ) {
frame = callstack.findCallFrame(func);
} else {
return argerror(a-2, "function or level");
}
// start a table
DebugInfo ar = callstack.auxgetinfo(what, (LuaFunction) func, frame);
LuaTable info = new LuaTable();
if (what.indexOf('S') >= 0) {
info.set(WHAT, LUA);
info.set(SOURCE, valueOf(ar.source));
info.set(SHORT_SRC, valueOf(ar.short_src));
info.set(LINEDEFINED, valueOf(ar.linedefined));
info.set(LASTLINEDEFINED, valueOf(ar.lastlinedefined));
}
if (what.indexOf('l') >= 0) {
info.set( CURRENTLINE, valueOf(ar.currentline) );
}
if (what.indexOf('u') >= 0) {
info.set(NUPS, valueOf(ar.nups));
info.set(NPARAMS, valueOf(ar.nparams));
info.set(ISVARARG, ar.isvararg? ONE: ZERO);
}
if (what.indexOf('n') >= 0) {
info.set(NAME, LuaValue.valueOf(ar.name!=null? ar.name: "?"));
info.set(NAMEWHAT, LuaValue.valueOf(ar.namewhat));
}
if (what.indexOf('t') >= 0) {
info.set(ISTAILCALL, ZERO);
}
if (what.indexOf('L') >= 0) {
LuaTable lines = new LuaTable();
info.set(ACTIVELINES, lines);
DebugLib.CallFrame cf;
for (int l = 1; (cf=callstack.getCallFrame(l)) != null; ++l)
if (cf.f == func)
lines.insert(-1, valueOf(cf.currentline()));
}
if (what.indexOf('f') >= 0) {
if (func != null)
info.set( FUNC, func );
}
return info;
}
}
// debug.getlocal ([thread,] f, local)
final class getlocal extends VarArgFunction {
public Varargs invoke(Varargs args) {
int a=1;
LuaThread thread = args.isthread(a)? args.checkthread(a++): globals.running;
int level = args.checkint(a++);
int local = args.checkint(a++);
CallFrame f = callstack(thread).getCallFrame(level);
return f != null? f.getLocal(local): NONE;
}
}
// debug.getmetatable (value)
final class getmetatable extends LibFunction {
public LuaValue call(LuaValue v) {
LuaValue mt = v.getmetatable();
return mt != null? mt: NIL;
}
}
// debug.getregistry ()
final class getregistry extends ZeroArgFunction {
public LuaValue call() {
return globals;
}
}
// debug.getupvalue (f, up)
static final class getupvalue extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaValue func = args.checkfunction(1);
int up = args.checkint(2);
if ( func instanceof LuaClosure ) {
LuaClosure c = (LuaClosure) func;
LuaString name = findupvalue(c, up);
if ( name != null ) {
return varargsOf(name, c.upValues[up-1].getValue() );
}
}
return NIL;
}
}
// debug.getuservalue (u)
static final class getuservalue extends LibFunction {
public LuaValue call(LuaValue u) {
return u.isuserdata()? u: NIL;
}
}
// debug.sethook ([thread,] hook, mask [, count])
final class sethook extends VarArgFunction {
public Varargs invoke(Varargs args) {
int a=1;
LuaThread t = args.isthread(a)? args.checkthread(a++): globals.running;
LuaValue func = args.optfunction(a++, null);
String str = args.optjstring(a++,"");
int count = args.optint(a++,0);
boolean call=false,line=false,rtrn=false;
for ( int i=0; i 0 && up <= c.upValues.length ) {
return valueOf(c.upValues[up-1].hashCode());
}
}
return NIL;
}
}
// debug.upvaluejoin (f1, n1, f2, n2)
final class upvaluejoin extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaClosure f1 = args.checkclosure(1);
int n1 = args.checkint(2);
LuaClosure f2 = args.checkclosure(3);
int n2 = args.checkint(4);
if (n1 < 1 || n1 > f1.upValues.length)
argerror("index out of range");
if (n2 < 1 || n2 > f2.upValues.length)
argerror("index out of range");
f1.upValues[n1-1] = f2.upValues[n2-1];
return NONE;
}
}
public void onCall(LuaFunction f) {
LuaThread t = globals.running;
if (t.inhook) return;
callstack().onCall(f);
if (t.hookcall && t.hookfunc != null)
callHook(CALL, NIL);
}
public void onCall(LuaClosure c, Varargs varargs, LuaValue[] stack) {
LuaThread t = globals.running;
if (t.inhook) return;
callstack().onCall(c, varargs, stack);
if (t.hookcall && t.hookfunc != null)
callHook(CALL, NIL);
}
public void onInstruction(int pc, Varargs v, int top) {
LuaThread t = globals.running;
if (t.inhook) return;
callstack().onInstruction(pc, v, top);
if (t.hookfunc == null) return;
if (t.hookcount > 0)
if (++t.bytecodes % t.hookcount == 0)
callHook(COUNT, NIL);
if (t.hookline) {
int newline = callstack().currentline();
if ( newline != t.lastline ) {
t.lastline = newline;
callHook(LINE, LuaValue.valueOf(newline));
}
}
}
public void onReturn() {
LuaThread t = globals.running;
if (t.inhook) return;
callstack().onReturn();
if (t.hookcall && t.hookfunc != null)
callHook(RETURN, NIL);
}
public String traceback(int level) {
return callstack().traceback(level);
}
void callHook(LuaValue type, LuaValue arg) {
LuaThread t = globals.running;
t.inhook = true;
try {
t.hookfunc.call(type, arg);
} catch (LuaError e) {
throw e;
} catch (RuntimeException e) {
throw new LuaError(e);
} finally {
t.inhook = false;
}
}
CallStack callstack() {
return callstack(globals.running);
}
CallStack callstack(LuaThread t) {
if (t.callstack == null)
t.callstack = new CallStack();
return (CallStack) t.callstack;
}
static class DebugInfo {
String name; /* (n) */
String namewhat; /* (n) 'global', 'local', 'field', 'method' */
String what; /* (S) 'Lua', 'C', 'main', 'tail' */
String source; /* (S) */
int currentline; /* (l) */
int linedefined; /* (S) */
int lastlinedefined; /* (S) */
short nups; /* (u) number of upvalues */
short nparams;/* (u) number of parameters */
boolean isvararg; /* (u) */
boolean istailcall; /* (t) */
String short_src; /* (S) */
CallFrame cf; /* active function */
public void funcinfo(LuaFunction f) {
if (f.isclosure()) {
Prototype p = f.checkclosure().p;
this.source = p.source != null ? p.source.tojstring() : "=?";
this.linedefined = p.linedefined;
this.lastlinedefined = p.lastlinedefined;
this.what = (this.linedefined == 0) ? "main" : "Lua";
this.short_src = p.shortsource();
} else {
this.source = "=[Java]";
this.linedefined = -1;
this.lastlinedefined = -1;
this.what = "Java";
this.short_src = f.name();
}
}
}
public static class CallStack {
final static CallFrame[] EMPTY = {};
CallFrame[] frame = EMPTY;
int calls = 0;
CallStack() {}
int currentline() {
return calls > 0? frame[calls-1].currentline(): -1;
}
private CallFrame pushcall() {
if (calls >= frame.length) {
int n = Math.max(4, frame.length * 3 / 2);
CallFrame[] f = new CallFrame[n];
System.arraycopy(frame, 0, f, 0, frame.length);
for (int i = frame.length; i < n; ++i)
f[i] = new CallFrame();
frame = f;
for (int i = 1; i < n; ++i)
f[i].previous = f[i-1];
}
return frame[calls++];
}
final void onCall(LuaFunction function) {
pushcall().set(function);
}
final void onCall(LuaClosure function, Varargs varargs, LuaValue[] stack) {
pushcall().set(function, varargs, stack);
}
final void onReturn() {
if (calls > 0)
frame[--calls].reset();
}
final void onInstruction(int pc, Varargs v, int top) {
frame[calls-1].instr(pc, v, top);
}
/**
* Get the traceback starting at a specific level.
* @param level
* @return String containing the traceback.
*/
String traceback(int level) {
StringBuffer sb = new StringBuffer();
sb.append( "stack traceback:" );
for (DebugLib.CallFrame c; (c = getCallFrame(level++)) != null; ) {
sb.append("\n\t");
sb.append( c.shortsource() );
sb.append( ':' );
if (c.currentline() > 0)
sb.append( c.currentline()+":" );
sb.append( " in " );
DebugInfo ar = auxgetinfo("n", c.f, c);
if (c.linedefined() == 0)
sb.append("main chunk");
else if ( ar.name != null ) {
sb.append( "function '" );
sb.append( ar.name );
sb.append( '\'' );
} else {
sb.append( "function <"+c.shortsource()+":"+c.linedefined()+">" );
}
}
sb.append("\n\t[Java]: in ?");
return sb.toString();
}
DebugLib.CallFrame getCallFrame(int level) {
if (level < 1 || level > calls)
return null;
return frame[calls-level];
}
DebugLib.CallFrame findCallFrame(LuaValue func) {
for (int i = 1; i <= calls; ++i)
if (frame[calls-i].f == func)
return frame[i];
return null;
}
DebugInfo auxgetinfo(String what, LuaFunction f, CallFrame ci) {
DebugInfo ar = new DebugInfo();
for (int i = 0, n = what.length(); i < n; ++i) {
switch (what.charAt(i)) {
case 'S':
ar.funcinfo(f);
break;
case 'l':
ar.currentline = ci != null && ci.f.isclosure()? ci.currentline(): -1;
break;
case 'u':
if (f != null && f.isclosure()) {
Prototype p = f.checkclosure().p;
ar.nups = (short) p.upvalues.length;
ar.nparams = (short) p.numparams;
ar.isvararg = p.is_vararg != 0;
} else {
ar.nups = 0;
ar.isvararg = true;
ar.nparams = 0;
}
break;
case 't':
ar.istailcall = false;
break;
case 'n': {
/* calling function is a known Lua function? */
if (ci != null && ci.previous != null) {
if (ci.previous.f.isclosure()) {
NameWhat nw = getfuncname(ci.previous);
if (nw != null) {
ar.name = nw.name;
ar.namewhat = nw.namewhat;
}
}
}
if (ar.namewhat == null) {
ar.namewhat = ""; /* not found */
ar.name = null;
}
break;
}
case 'L':
case 'f':
break;
default:
// TODO: return bad status.
break;
}
}
return ar;
}
}
static class CallFrame {
LuaFunction f;
int pc;
int top;
Varargs v;
LuaValue[] stack;
CallFrame previous;
void set(LuaClosure function, Varargs varargs, LuaValue[] stack) {
this.f = function;
this.v = varargs;
this.stack = stack;
}
public String shortsource() {
return f.isclosure()? f.checkclosure().p.shortsource(): "[Java]";
}
void set(LuaFunction function) {
this.f = function;
}
void reset() {
this.f = null;
this.v = null;
this.stack = null;
}
void instr(int pc, Varargs v, int top) {
this.pc = pc;
this.v = v;
this.top = top;
if (TRACE)
Print.printState(f.checkclosure(), pc, stack, top, v);
}
Varargs getLocal(int i) {
LuaString name = getlocalname(i);
if ( name != null )
return varargsOf( name, stack[i-1] );
else
return NIL;
}
Varargs setLocal(int i, LuaValue value) {
LuaString name = getlocalname(i);
if ( name != null ) {
stack[i-1] = value;
return name;
} else {
return NIL;
}
}
int currentline() {
if ( !f.isclosure() ) return -1;
int[] li = f.checkclosure().p.lineinfo;
return li==null || pc<0 || pc>=li.length? -1: li[pc];
}
String sourceline() {
if ( !f.isclosure() ) return f.tojstring();
return f.checkclosure().p.shortsource() + ":" + currentline();
}
private int linedefined() {
return f.isclosure()? f.checkclosure().p.linedefined: -1;
}
LuaString getlocalname(int index) {
if ( !f.isclosure() ) return null;
return f.checkclosure().p.getlocalname(index, pc);
}
}
static LuaString findupvalue(LuaClosure c, int up) {
if ( c.upValues != null && up > 0 && up <= c.upValues.length ) {
if ( c.p.upvalues != null && up <= c.p.upvalues.length )
return c.p.upvalues[up-1].name;
else
return LuaString.valueOf( "."+up );
}
return null;
}
static void lua_assert(boolean x) {
if (!x) throw new RuntimeException("lua_assert failed");
}
static class NameWhat {
final String name;
final String namewhat;
NameWhat(String name, String namewhat) {
this.name = name;
this.namewhat = namewhat;
}
}
// Return the name info if found, or null if no useful information could be found.
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" );
}
// return NameWhat if found, null if not
public static NameWhat getobjname(Prototype p, int lastpc, int reg) {
int pc = lastpc; // currentpc(L, ci);
LuaString name = p.getlocalname(reg + 1, pc);
if (name != null) /* is a local? */
return new NameWhat( name.tojstring(), "local" );
/* else try symbolic execution */
pc = findsetreg(p, lastpc, reg);
if (pc != -1) { /* could find instruction? */
int i = p.code[pc];
switch (Lua.GET_OPCODE(i)) {
case Lua.OP_MOVE: {
int a = Lua.GETARG_A(i);
int b = Lua.GETARG_B(i); /* move from `b' to `a' */
if (b < a)
return getobjname(p, pc, b); /* get name for `b' */
break;
}
case Lua.OP_GETTABUP:
case Lua.OP_GETTABLE: {
int k = Lua.GETARG_C(i); /* key index */
int t = Lua.GETARG_B(i); /* table index */
LuaString vn = (Lua.GET_OPCODE(i) == Lua.OP_GETTABLE) /* name of indexed variable */
? p.getlocalname(t + 1, pc)
: (t < p.upvalues.length ? p.upvalues[t].name : QMARK);
name = kname(p, k);
return new NameWhat( name.tojstring(), vn != null && vn.eq_b(ENV)? "global": "field" );
}
case Lua.OP_GETUPVAL: {
int u = Lua.GETARG_B(i); /* upvalue index */
name = u < p.upvalues.length ? p.upvalues[u].name : QMARK;
return new NameWhat( name.tojstring(), "upvalue" );
}
case Lua.OP_LOADK:
case Lua.OP_LOADKX: {
int b = (Lua.GET_OPCODE(i) == Lua.OP_LOADK) ? Lua.GETARG_Bx(i)
: Lua.GETARG_Ax(p.code[pc + 1]);
if (p.k[b].isstring()) {
name = p.k[b].strvalue();
return new NameWhat( name.tojstring(), "constant" );
}
break;
}
case Lua.OP_SELF: {
int k = Lua.GETARG_C(i); /* key index */
name = kname(p, k);
return new NameWhat( name.tojstring(), "method" );
}
default:
break;
}
}
return null; /* no useful name found */
}
static LuaString kname(Prototype p, int c) {
if (Lua.ISK(c) && p.k[Lua.INDEXK(c)].isstring())
return p.k[Lua.INDEXK(c)].strvalue();
else
return QMARK;
}
/*
** try to find last instruction before 'lastpc' that modified register 'reg'
*/
static int findsetreg (Prototype p, int lastpc, int reg) {
int pc;
int setreg = -1; /* keep last instruction that changed 'reg' */
for (pc = 0; pc < lastpc; pc++) {
int i = p.code[pc];
int op = Lua.GET_OPCODE(i);
int a = Lua.GETARG_A(i);
switch (op) {
case Lua.OP_LOADNIL: {
int b = Lua.GETARG_B(i);
if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */
setreg = pc;
break;
}
case Lua.OP_TFORCALL: {
if (reg >= a + 2) setreg = pc; /* affect all regs above its base */
break;
}
case Lua.OP_CALL:
case Lua.OP_TAILCALL: {
if (reg >= a) setreg = pc; /* affect all registers above base */
break;
}
case Lua.OP_JMP: {
int b = Lua.GETARG_sBx(i);
int dest = pc + 1 + b;
/* jump is forward and do not skip `lastpc'? */
if (pc < dest && dest <= lastpc)
pc += b; /* do the jump */
break;
}
case Lua.OP_TEST: {
if (reg == a) setreg = pc; /* jumped code can change 'a' */
break;
}
default:
if (Lua.testAMode(op) && reg == a) /* any instruction that set A */
setreg = pc;
break;
}
}
return setreg;
}
}