Lua decompiler (mostly) FIXED - .luac files ready for your viewing pleasure!

[taw]

This was a quick win, based again on previous work by other modders.

It you just want to look, get attached zip.

If you want to decode more .luac files, here's what you do:

• You need C compiler, clue about programming etc. This is not for everyone.

First we need lua:

• Get lua 5.1 sources
• In src/luaconf.h change lines
  
  • #define LUA_NUMBER_DOUBLE
    #define LUA_NUMBER double
    to
  
  
  
  • #define LUA_NUMBER_FLOAT
    #define LUA_NUMBER float
• compile lua with command appropriate for your platform like:
  
  • make macosx - I only tested this one, on 32 bit OS
  • make linux
  • make mingw
  • make generic - this should work too I think

Now luadec:

• Get luadec51_2.0 sources
• In print.c line 15 change line in getupval command (line 45 here) from:
  
  • if (F->f->upvalues) {
• to
  
  • if (F->f->upvalues && r < F->f->sizeupvalues) {
• Compile it pointing to directory where original lua is located (tweak for your platform):
  
  • gcc -g -I ../../lua-5.1.4/src/ *.c -c
  • gcc ../../lua-5.1.4/src/liblua.a *.o -o luadec

Now back up this luadec executable somewhere so you don't have to go through this nonsense again.

Use pack manager to extract .luac files, then decompile each one of them with ./luadec -d xxx.luac >xxx.lua

Before that print.c patch, of 438 .luac files I found in patch.pack, 171 crashed on decompilation - including nearly all interesting ones - successes were mostly trivial files. Now only 16 crash, so almost all can be viewed.

You can always decompile all files to lua assembly with ./luadec -dis xxx.luac but this is a lot more difficult to read.

Now I did not fix the underlying problem!!! The only thing I did was making luadec not crash on first confusing setupval opcode.

Decompiled lua code might very well still be wrong (it's really lua 5.0 decompiler only halfway upgraded to lua 5.1 that ETW uses). At least you will get a warning (thanks to -d option) in places where luadec is confused, and this seems to be per-function confusion, so other decompiled functions in the same file will be fine.

I'm attaching zip with .patch for luadec and decoded .lua files from patch.pack. 0 size means luadec still crashes, just so you don't have to guess.

[taw]

I contacted author of luadec with what I think are all relevant details.
Hopefully he'll have more clue on what needs to be done to move it from mostly-fixed to fully-fixed.

[taw]

A single command script to fetch, patch, and build luadec for ETW .luac files now available in etwng repository.
It would be neat if someone took a few minutes to make it work on systems other than OSX,
This is trivial matter, lua compiles on Windows out of the box, but I don't have Windows-based
development environment to even try that.

[taw]

As many people have problems with luadec, I prepared a 7z archive with decompilation results of all .luac files in ETW and NTW.

PM with your email address to get it.

[taw]

luadec now builds on both OSX and Linux.

People who had troubles finding an OSX machine to try it might want to give it another go -
Linux machines (and livecds) are a lot easier to find.

[wangrin]

I'm trying to compile luadec on windows 7, but I get errors :

The first step was to download LUA 5.1 sources from lua.org
The second step was to download luadec installer from luaforge.org
The third step was to download and install MinGW from sourceforge

To install MinGW, I use basic setups and add 3 packages :

• mingw32-base
• mingw32-gcc-g++
• msys-base

According to this tutorial : Installing Lua on a Windows system

Then, I've tried to compile luadec for windows system, but I get errors during the process :

D:\LUADEC\lua-5.1>make clean
cd src && make clean
make[1]: Entering directory `/d/LUADEC/lua-5.1/src'
rm -f liblua.a lua luac lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex
.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundu
mp.o lvm.o lzio.o lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o loslib.o lta
blib.o lstrlib.o loadlib.o linit.o lua.o luac.o print.o
make[1]: Leaving directory `/d/LUADEC/lua-5.1/src'

D:\LUADEC\lua-5.1>make mingw
cd src && make mingw
make[1]: Entering directory `/d/LUADEC/lua-5.1/src'
make "LUA_A=lua51.dll" "LUA_T=lua.exe" \
        "AR=gcc -shared -o" "RANLIB=strip --strip-unneeded" \
        "MYCFLAGS=-DLUA_BUILD_AS_DLL" "MYLIBS=" "MYLDFLAGS=-s" lua.exe
make[2]: Entering directory `/d/LUADEC/lua-5.1/src'
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lua.o lua.c
make[2]: gcc: Command not found
make[2]: *** [lua.o] Error 127
make[2]: Leaving directory `/d/LUADEC/lua-5.1/src'
make[1]: *** [mingw] Error 2
make[1]: Leaving directory `/d/LUADEC/lua-5.1/src'
make: *** [mingw] Error 2

As gcc command is not found, do I need some other package or is it a filepath issue ?

All file needed are in the LUADEC folder, itself divided in subfolders :

• lua-5.1
• MinGW

luadec.exe is in LUADEC folder.
MinGW files are in LUADEC\MinGW subfolder.

[taw]

Well, gcc not found sounds like filepath issue. I never tried it on mingw, just OSX and Linux, but in principle it should work on Windows as well.

[wangrin]

In "Environment variables", I had two entries for PATH, one for JRuby and the other for MinGW, both entry are separate by ";" :

C:\Program Files\jruby-1.5.6\bin;D:\LUADEC\MinGW\bin

I temporarily add MSYS to my system path using command :

SET PATH=%PATH%;D:\LUADEC\MinGW\msys\1.0\bin

Then, I have a strange behaviour in the cmd prompt.
When I add the command :

CD D:\LUADEC\lua-5.1

to change folder, it doesn't work first.

I have to add the command :
[code]d:[code]
to get the right folder.

But it doesn't matter as the two first steps work now that I launch cmd as administrator :

• make clean
• make mingw

Now, it's with the last step I have a problem :

D:\LUADEC\lua-5.1>make install INSTALL_TOP=D:/LUADEC/LUA/5.1 TO_BIN="lua.exe luac.exe lua51.dll"
cd src && mkdir -p D:/LUADEC/LUA/5.1/bin D:/LUADEC/LUA/5.1/include D:/LUADEC/LUA/5.1/lib D:/LUADEC/LUA/5.1/man/man1 D:/LUADEC/LUA/5.1/share/lua/5.1 D:/LUADEC/LUA/5.1/lib/lua/5.1
cd src && cp lua.exe luac.exe lua51.dll D:/LUADEC/LUA/5.1/bin
cp: cannot stat `luac.exe': No such file or directory
make: *** [install] Error 1

When I should obtain something like this

c:\temp\lua-5.1.5>make install INSTALL_TOP=c:/temp/lua/5.1 TO_BIN="lua.exe luac.exe lua51.dll"
cd src && mkdir -p c:/temp/lua/5.1/bin c:/temp/lua/5.1/include c:/temp/lua/5.1/lib c:/temp/lua/5.1/man/man1 c:/temp/lua/5.1/share/lua/5.1 c:/temp/lua/5.1/lib/lua/5.1
cd src && install -p -m 0755 lua.exe luac.exe lua51.dll c:/temp/lua/5.1/bin
cd src && install -p -m 0644 lua.h luaconf.h lualib.h lauxlib.h ../etc/lua.hpp c:/temp/lua/5.1/include
cd src && install -p -m 0644 liblua.a c:/temp/lua/5.1/lib
cd doc && install -p -m 0644 lua.1 luac.1 c:/temp/lua/5.1/man/man1

What I want is to store the new file in a LUA folder (D:\LUADEC\LUA).
Folder is created as well as several other sub-folders and files.

[taw]

Well, it sounds like it built

lua.exe

but not

luac.exe

. Was there anything about it during

make mingw

?

[wangrin]

It worked fine :

D:\LUADEC\lua-5.1>make mingw
cd src && make mingw
make[1]: Entering directory `/d/LUADEC/lua-5.1/src'
make "LUA_A=lua51.dll" "LUA_T=lua.exe" \
        "AR=gcc -shared -o" "RANLIB=strip --strip-unneeded" \
        "MYCFLAGS=-DLUA_BUILD_AS_DLL" "MYLIBS=" "MYLDFLAGS=-s" lua.exe
make[2]: Entering directory `/d/LUADEC/lua-5.1/src'
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lua.o lua.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lapi.o lapi.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lcode.o lcode.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ldebug.o ldebug.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ldo.o ldo.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ldump.o ldump.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lfunc.o lfunc.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lgc.o lgc.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o llex.o llex.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lmem.o lmem.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lobject.o lobject.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lopcodes.o lopcodes.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lparser.o lparser.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lstate.o lstate.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lstring.o lstring.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ltable.o ltable.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ltm.o ltm.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lundump.o lundump.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lvm.o lvm.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lzio.o lzio.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lauxlib.o lauxlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lbaselib.o lbaselib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ldblib.o ldblib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o liolib.o liolib.c
liolib.c: In function 'read_number':
liolib.c:259:3: warning: format '%lf' expects argument of type 'double *', but argument 3 has type 'lua_Number *' [-Wformat=]
   if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
   ^
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lmathlib.o lmathlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o loslib.o loslib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o ltablib.o ltablib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o lstrlib.o lstrlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o loadlib.o loadlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL   -c -o linit.o linit.c
gcc -shared -o lua51.dll lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o loslib.o ltablib.o lstrlib.o loadlib.o linit.o
strip --strip-unneeded lua51.dll
gcc -o lua.exe -s lua.o lua51.dll -lm
make[2]: Leaving directory `/d/LUADEC/lua-5.1/src'
make[1]: Leaving directory `/d/LUADEC/lua-5.1/src'

When I should get something like this

c:\temp\lua-5.1.5>make mingw
cd src && make mingw
make[1]: Entering directory `/c/temp/lua-5.1.5/src'
make "LUA_A=lua51.dll" "LUA_T=lua.exe" \
 "AR=gcc -shared -o" "RANLIB=strip --strip-unneeded" \
 "MYCFLAGS=-DLUA_BUILD_AS_DLL" "MYLIBS=" "MYLDFLAGS=-s" lua.exe
make[2]: Entering directory `/c/temp/lua-5.1.5/src'
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lua.o lua.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lapi.o lapi.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lcode.o lcode.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ldebug.o ldebug.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ldo.o ldo.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ldump.o ldump.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lfunc.o lfunc.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lgc.o lgc.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o llex.o llex.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lmem.o lmem.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lobject.o lobject.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lopcodes.o lopcodes.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lparser.o lparser.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lstate.o lstate.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lstring.o lstring.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ltable.o ltable.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ltm.o ltm.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lundump.o lundump.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lvm.o lvm.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lzio.o lzio.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lauxlib.o lauxlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lbaselib.o lbaselib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ldblib.o ldblib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o liolib.o liolib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lmathlib.o lmathlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o loslib.o loslib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o ltablib.o ltablib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o lstrlib.o lstrlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o loadlib.o loadlib.c
gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o linit.o linit.c
gcc -shared -o lua51.dll lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o loslib.o ltablib.o lstrlib.o loadlib.o linit.o # DLL needs all object files
strip --strip-unneeded lua51.dll
gcc -o lua.exe -s lua.o lua51.dll -lm
make[2]: Leaving directory `/c/temp/lua-5.1.5/src'
make "LUAC_T=luac.exe" luac.exe
make[2]: Entering directory `/c/temp/lua-5.1.5/src'
gcc -O2 -Wall -c -o luac.o luac.c
gcc -O2 -Wall -c -o print.o print.c
ar rcu liblua.a lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o loslib.o ltablib.o lstrlib.o loadlib.o linit.o # DLL needs all object files
ranlib liblua.a
gcc -o luac.exe luac.o print.o liblua.a -lm
make[2]: Leaving directory `/c/temp/lua-5.1.5/src'
make[1]: Leaving directory `/c/temp/lua-5.1.5/src'

So, it gets trouble with "gcc -O2 -Wall -DLUA_BUILD_AS_DLL -c -o liolib.o liolib.c"
And it doesn't run "make "LUAC_T=luac.exe" luac.exe"... so, it's possible it doesn't create luac.exe

[taw]

Output looks reasonable, so no idea why it can't find luac.exe later.

[wangrin]

As the program doesn't execute "make "LUAC_T=luac.exe" luac.exe" command, maybe it doesn't create luac.exe

I've tried to manually run the command :

D:\LUADEC\lua-5.1>cd src

D:\LUADEC\lua-5.1\src>make "LUAC_T=luac.exe" luac.exe
gcc -O2 -Wall    -c -o luac.o luac.c
gcc -O2 -Wall    -c -o print.o print.c
ar rcu liblua.a lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o loslib.o ltablib.o lstrlib.o loadlib.o linit.o
ranlib liblua.a
gcc -o luac.exe  luac.o print.o liblua.a -lm.

And then re-run the command

D:\LUADEC\lua-5.1>make install INSTALL_TOP=D:/LUADEC/LUA/5.1 TO_BIN="lua.exe lua
c.exe lua51.dll"
cd src && mkdir -p D:/LUADEC/LUA/5.1/bin D:/LUADEC/LUA/5.1/include D:/LUADEC/LUA/5.1/lib D:/LUADEC/LUA/5.1/man/man1 D:/LUADEC/LUA/5.1/share/lua/5.1 D:/LUADEC/LUA/5.1/lib/lua/5.1
cd src && cp lua.exe luac.exe lua51.dll D:/LUADEC/LUA/5.1/bin
cd src && cp lua.h luaconf.h lualib.h lauxlib.h ../etc/lua.hpp D:/LUADEC/LUA/5.1/include
cd src && cp liblua.a D:/LUADEC/LUA/5.1/lib
cd doc && cp lua.1 luac.1 D:/LUADEC/LUA/5.1/man/man1

Now, I have all three files : lua.exe, luac.exe and lua51.dll

[Liberalis Bellatricus]

Any new advancements ?

[taw]

Any new advancements ?

It does what it can, unless someone wrote actual lua 5.1 decompiler that's more or less as good as it's going to get.

[LordChatalot]

Do you have the zip file still or a complete version of the decompiler? Cause the attachment is gone, I think...

[taw]

Order of Shadows: Could you try one in https://github.com/taw/etwng/tree/master/luac ? I haven't used it in ages, hopefully it will still work out of the box.

(if not, I can take a look at it later)

[LordChatalot]

So, I downloaded LuaDec, copied the text of build_luadec and created with it a .bat file, then I created another bat file with this code: ./luadec -d xxx.luac >xxx.lua == luadec == (I overwrite the file paths)
I ran build_luadec and then the second .bat file, but I get only an empty lua file.
So I'm not sure about what to download, and I found not a way to download some of the files in the etwng repository, so I made them by myself, but I am actually not sure about what file format to choose.
So it would be really nice if you could explain me some steps to use this

[taw]

So, I downloaded LuaDec, copied the text of build_luadec and created with it a .bat file, then I created another bat file with this code: ./luadec -d xxx.luac >xxx.lua == luadec == (I overwrite the file paths)
I ran build_luadec and then the second .bat file, but I get only an empty lua file.
So I'm not sure about what to download, and I found not a way to download some of the files in the etwng repository, so I made them by myself, but I am actually not sure about what file format to choose.
So it would be really nice if you could explain me some steps to use this

I only ever made it work on OSX and Linux. It seems to still be working on OSX file at least.

Do you have access to any kind of OSX/Linux box or VM to test it first? It could presumably be made to work on Windows+cygwin without too much hassle otherwise.

[LordChatalot]

I only ever made it work on OSX and Linux. It seems to still be working on OSX file at least.

Do you have access to any kind of OSX/Linux box or VM to test it first? It could presumably be made to work on Windows+cygwin without too much hassle otherwise.

Sorry, I'm only Windows User and I have no experience with VM so I would prefer cygwin.

[taw]

OK, jruby build_luadec will compile some kind of luadec on cygwin now, but I didn't have any time to check if it's the right flags (it needs to be 32 bit to match Total War engine).

You need to have all the prerequisites (gcc, patch, wget etc.) preinstalled of course.