We are looking for quick basic decompiler. The program is very old, written in DOS now we wish to enhance that code in Windows with additional functionalities. Unfortunately the developer is not traceable and only hope is decompilation.
Please suggest the best way to achieve this challenge.
Thank you
[ By Dan in the QB forum on http://qbasicnews.com , May 04, 2003 ]
Here's Microsoft's response to that question:
Microsoft does not currently offer any product capable of "decompiling" an object (.OBJ) or executable (.EXE) file back to the original source code (.BAS). The following are several reasons for this:
No decompiler could exactly reproduce the original source code.
When a program is compiled to an object and linked to produce an executable, most of the "names" used in the original program are converted to addresses. This loss of names means that a decompiler would have to create unique names for all the variables, procedures, and labels, and these names would not be meaningful in the context of the program.
Obviously, source language syntax no longer exists in the compiled object file or executable. It would be very difficult for a decompiler to interpret the series of machine language instructions that exist in an object or executable file and decide what the original source language instruction was.
If such a decompiler did exist and was available, anyone could use it to decompile any executable program produced in the language the decompiler was designed for.
For instance, if a Microsoft BASIC decompiler existed, anyone with that decompiler could use it on an executable that you had produced and from that executable obtain a copy of your source code. The source code to any program you wrote in Microsoft BASIC would be available to anyone with the decompiler. Few developers of commercial software would want to use a language product that could be deciphered, thus allowing others to obtain their source code.
There's some talk from ex-microsoft programmers who swear there was one made for thier private use. I've also seen a Basic decompiler service on a web site which does provide some working BAS code from your exe, but it's a mess and not worth the money asked for the service (http://02c1289.netsolhost.com).
I can tell you as a BASIC software developer for nearly all of my career that this is not what you want. When it came time to "port" my accounting software from DOS BASIC to Visual BASIC having the source code and a complete understanding of the code, since it was my own code, did not help in the least. It may be an over-used expression, but DOS and Windows are apples and oranges. You cannot simply convert the code, you must redesign and code the system.
All you need to do that is what you already have - a working version of the compiled code. Use it's screens to design your databases and screens in Windows, then write the underlying code. The design of those two things is often half to 90% of the work anyway. Now it did help me to have my own source for things like "how did I calculate those taxes again?" I could copy the pure logic code from DOS to Windows with little or no change, but anything involving the database or user interface had to be completely redone.
If you're not up to it, look for someone who is.
Again, you do NOT need the source code unless there's some kind of secret algorithm that you need to duplicate and don't understand yourself.
Related
I have discovered that our SQL statements are appearing in our compiled DLL files in our WinForms projects. What are some good methods of hiding these statements in the DLL files?
The term you are looking for is obfuscation and there are several commercial products that will do that, as well as some open source ones.
Bear in mind, that someone determined enough will be able to see the strings. That can be done through de-obfuscation techniques or by examining the strings at run time with a debugger like WinDbg.
Obfuscators should be used to protect intellectual property, at best. They should not be counted on for the security of your application. If you are hard coding credentials in your application, I would instead re-consider where they are getting stored or retrieved from. There is no "one-size" answer for that.
I wish to get a quick feeling for how much “copy and paste” coding we have, there are many tools for C# / Java to check for this type of thing. Are there any such tools that work well with VB.NET?
(I have seen what looks like lots of repeated code, but wish to get some number to help me make a case for sorting it out)
Update on progress.
I have just tried Simian.
It does not seem to be able to produce a nicely formatted report I can sent by email
It does not cope when the names of local variables, or parameters etc may have been changed, e.g it just matches on lines of text being the same.
Clone Doctor does not support VB.NET (only C# and VB 6 and lot of other)
October 2010: VB.net added to langauges supported by CloneDR
Clone Detective for Visual Studio only supports C#
SolidSDD - Source Code Duplication Detector only supports C, C++, C# and Java
DuplicateFinder is open source, but otherwise looks very match like Simian, e.g it just works on lines of text
ConQAT - Continuous Quality Assessment Toolkit seems to have a clone detector that works for VB.NET (not tried it yet)
Gendarme is a bit like FXCop and has a AvoidCodeDuplicatedInSameClassRule rule, this looks very promising, as it avoids the problem of working at the text level. Just tried it, it is the best solution so far, pity it does not search with a greater scope.
Before claiming that this question is a duplicate, please check that the other question addresses VB.NET, as a lot of tools that work well for C# don't work so well for VB.NET. (However it would not surprise me if this question is a real duplicate)
CodeRush 11.2 introduced a new feature called Duplicate Detection and Consolidation (DDC)
http://community.devexpress.com/blogs/markmiller/archive/2011/11/29/duplicate-detection-and-consolidation-in-coderush-for-visual-studio.aspx
Make sure to check out the options for it as well, as you can have it run when so many lines are changed, certainly time has passed, etc.
They've posted some decent videos on the DevExpress site too.
Simian: http://www.redhillconsulting.com.au/products/simian/
[I'm the author of CloneDR ("Clone Doctor").]
CloneDR is parameterized by a full grammar for the programming language in question. So it doesn't just match lines. Rather, it can find clones which are syntactically well-formed, with variations that are more than just identifier changes, regardless of where they stop or start in a line.
The engine on which CloneDR rests, The DMS Software Reengineering Toolkit" is a tool for analyzing large scale systems in any programming language, and uses language descriptions to drive the analysis. DMS has a wide variety of language front ends already available.
Presently it has VBScript and VB6 (as dialects of "Visual Basic"). It doesn't have VB.net, but that would be pretty straightforward to do given the DMS infrastructure and our experience with lots of other languages.
So, CloneDR could do this just fine, with a small bit of effort on our part.
EDIT October 2010: VB.net added as a language CloneDR can process.
Atomiq supports vb.net amongst other languages, and the results are nicely presented.
JetBrains published console tool set Resharper Console Tools to run duplication analysis. Once installed it allows you to do the same analysis as TeamCity does and generate duplicates report locally and even include duplicates search into custom build process with MSBuild. This tool does exactly what you need. More details you can find here at JetBrains blog post
Try Simian:
Simian (Similarity Analyser) identifies duplication in Java, C#, C, C++, COBOL, Ruby, JSP, ASP, HTML, XML, Visual Basic, Groovy source code and even plain text files.
I once saw an impressive demo of Pattern Insight; its CP Miner may be what you’re looking for: http://patterninsight.com/products/cp-miner.php. It seems to be language-independent, though I couldn’t find anything explicit about languages other than C/C++.
Roll up your sleeves and write your own parser to use it with CPD?
See the question for the tools I found.
see also VB.NET Static Code Anaylsis
For better or for worst we now have a VB.NET coding standards document that is based on a C# coding standard as enforced by StyleCop.
For example
the number of spaces you should put in each side of a “+” sign etc
all instance Members (fields and methods!) must be access as “me.fieldName”
all shared members must be accessed as “className.fieldName”
As I tend to think:
If it’s in a requirements document it
should be check for by an automatic
system
I am looking for (ideally free) tools that will check for that short of rules on VB.NET code, as these are style issues that don’t make it into the compiled output, FxCop is not useful.
(I would personally match rather that we just check for important things like duplicated code and single reasonability for each class (so no more multi thousand line classes!), but as I need to keep to the coding standard document I wish to have a tool to help me do so.)
see also Enforcing using the class name whenever a shared member is accessed.
About the bounty.
I am looking for a list of VB.NET code checking tools, with a short summery of what each tool can do and its limitations. If the tools are not free, please include some ideal of cost.
Does anyone have experience using CodeRush/Refactor! or ReSharper with VB.NET to check for this type of coding style issues?
I know of no free source code analysis tools with good VB support. There are, however, at least two commercial tools that may be suitable:
submain CodeIt.Right
SSW Code Auditor
Personally, I prefer the CodeIt.Right rule authoring mechanism, so I would favour it if considerable custom rule development were planned. However, if you just want to use out-of-the box rules, Code Auditor ships with quite a few more code style rules than CodeIt.Right, most of whose built-in rules target the compiled IL (like FxCop).
The only ones I know of are:
Microsoft's FxCop
Of course, this only operates on compiled assemblies, so doesn't give the same functionality as StyleCop, and certainly won't help with things like naming schemes.
However, the closest thing is:
Aivosto's Project Analyzer v9.0 for Visual Basic, VB.NET and VBA
The full version is not free, but this is the closest thing to StyleCop for VB.NET that I can find.
There have been a number of calls for a VB.NET version of Microsoft's StyleCop, such as those in this thread on the code.msdn.microsoft.com site. That same thread also gives some good insight into why a VB.NET version doesn't exist.
I use ReSharper on a daily basis and I find it fine for both code formatting and for solving naming issues. It allows to configure how naming must be enforced, how issues are displayed (hint, suggestion, warning, etc) and provides a precise code formatter (space, paranthesis, line breaks, this qualifier, etc).
Note that I don't know if it can be run in batch mode.
Turning Option Explicit on by default is always a great idea and should be standard practice. I would argue it should be turned on by default in VS out of the box. But it doesn't come close to enforcing the out of the box rules that StyleCop does for C#, nor does it allow for you to create your own rules.
The whole reason for StyleCop's existence is because FxCop only works on compiled assemblies, leaving web projects out in the cold for a similar tool. With StyleCop, web developers get the same great rule enforcement and tight VS integration. It is a great tool for any C# developer.
It is unfortunate that it is only C# capable, a VB version would satisfy a large community that is left wanting something similar.
There already is a very good style tool built into the VB compiler. It is called Option Explicit On, put it at the top of the source code file or use Tools + Options + Project and Solutions + VB Defaults, Option Explicit = On. If that wasn't turned on previously there could be a mountain of errors when you compile your code after changing that.
If it is clean or already turned on, consider that you are 95% close to writing clean C# code and that the language doesn't really matter anymore.
Before answering this question, understand that I am not asking how to create my own programming language, I am asking how, using vb.net code, I can create a compiler for a language like vb.net itself. Essentially, the user inputs code, they get a .exe. By NO MEANS do I want to write my own language, as it seems other compiler related questions on here have asked. I also do not want to use the vb.net compiler itself, nor do I wish to duplicate the IDE.
The exact purpose of what I wish to do is rather hard to explain, but all I need is a nudge in the right direction for writing a compiler (from scratch if possible) which can simply take input and create a .exe. I have opened .exe files as plain text before (my own programs) to see if I could derive some meaning from what I assumed would be human readable text, yet I was obviously sorely disappointed to see the random ascii, though it is understandable why this is all I found.
I know that a .exe file is simply lines of code, being parsed by the computer it is on, but my question here really boils down to this: What code makes up a .exe? How could I go about making one in a plain text editor if I wanted to? (No, I do not want to do that, but if I understand the process my goals will be much easier to achieve.) What makes an executable file an executable file? Where does the logic of the code fit in?
This is intended to be a programming question as opposed to a computer question, which is why I did not post it on SuperUser. I know plenty of information about the System.IO namespace, so I know how to create a file and write to it, I simply do not know what exactly I would be placing inside this file to get it to work as an executable file.
I am sorry if this question is "confusing", "dumb", or "obvious", but I have not been able to find any information regarding the actual contents of an executable file anywhere.
One of my google searches
Something that looked promising
EDIT: The second link here, while it looked good, was an utter fail. I am not going to waste hours of my time hitting keys and recording the results. "Use the "Alt" and the 3-digit combinations to create symbols that do not appear on the keyboard but that you need in the program." (step 4) How the heck do I know what symbols I need???
Thank you very much for your help, and my apologies if this question is a nooby or "bad" one.
To sum this up simply: I want to create a program in vb.net that can compile code in a particular language to a single executable file. What methods exist that can allow me to do this, and if there are none, how can I go about writing my own from scratch?
What you're asking is a pretty complex question. Sure, at its core it seems pretty basic:
Interpret the code itself
Write out the interpreted code
but each of those steps can be pretty intense. Step 1 should be somewhat achievable with some time and a LOT of elbow grease - you need to parse the code into a number of control statements based upon the specification of the language. Check out http://en.wikipedia.org/wiki/Parsing for more information on this step. In essence you're converting the typed code into a common format that represents the functionality you want.
Once you've parsed the code, the next step would be to take that parsed code and convert it into machine-runnable code (typically assembly, though with VB.NET you can write Microsoft Intermediate Language code as the output and then run it in the CLR). This is what will actually create the executable file in a manner that lets the computer run the program.
Unfortunately, the best advice for solving this problem is to either:
Go purchase several books on a programming language, machine code, assembly language, compilers, and so on, then spend several months or years reading and experimenting until the knowledge you gain from the books results in your writing a successful compiler.
Enroll in a computer science program at a local university. Writing compilers and programming languages are usually covered at a rudimentary level during the second or third year of a BS in computer science, and then in much more depth at a graduate level.
Good luck!
EDIT: If all you're looking for is a way to write code and then write a way to execute it, you might try looking at writing an interpreter for one of the scripting languages that already exist - Ruby, Python, Lua, etc.
Process.Start(String.Format("vbc.exe {0}", sourceFilePath))
Here is one book that explains it all at a very basic level. Including sample code that you can get working in a matter of hours.
As with many programming endevors, it will take you many months of study to accomplish what you want. Good luck!!
Let me start by saying this is totally doable. Ignore the naysayers.
OK, so it seems you bit off more than you could chew here. I would suggest slightly re-evaluating your goal. It seems that you want to learn how compilers work, and writing a VB.net compiler is your project to get started.
Try instead to write an interpreter, which is a much smaller and simpler task. Here's how you do it:
Write a parser for a very very small language, maybe only supporting assignment statements. Use a parser toolkit, like Antlr. This will build an AST ("abstract syntax tree" - ie a few classes or objects representing the program's syntax, without the crap like semi-colons, as a tree), which will look something like this:
then you go through the AST, and just execute it. Google for "AST walker". So for the assignment x = 5, create a hashtable entry for 'x', assign 5 to it, then move on to the next statement.
keep adding features as you go.
Once you've got the full language, you'll probably have learned enough on the way to understand the compiler books. Don't use the dragon book, try Appel's book instead, or Cooper/Torczon. There are online books if you prefer, I've never tried them.
When you go to write the compiler, you'll just be changing the bit that executes the AST into one which generates assembly (or C if you prefer) which will do the same action when it's run.
I'll grant that it seems daunting, but if you stick to a something simple to start, you'll get something working in a few days at most. In a few months, you'll have built it up to something like what you're looking for. Good luck.
To the final part of your question:
It seems that you don't know how executables are made from code. People haven't messed with hex in their compilers since the 80s, and hopefully not much even then.
Basically, after parsing the code, you go through a series of steps which make the code progressively simpler. At the end of that, you have something that is quite close to assembly. You then generate assembly, and the assembler and linker conspire to make it into an executable.
The Visual Basic .NET compiler is shipped for free as part of the .NET Framework - you don't even need the SDK or Express Editions. The compiler for VB (and C#) is located at c:\windows\microsoft.net\framework[version]\vbc.exe (or csc.exe for C#). Therefore, any computer which can run a VB.NET program can compile one. The .NET Framework also includes the System.CodeDom namespace which provides a way from within a program to compile a program, either from a document model or from a string (or file) into a .NET assembly (.exe or .dll) and generate code in both VB and C#.
Regards,
Anthony D. Green | Program Manager | Visual Basic Compiler
You create a compiler for vb.net the same way you create any other compiler. You need a lexer/parser. Entire books have been written on this topic, the most famous probably being The Dragon Book.
To provide a definitive answer: No, you cannot create a decent compiler that will generate an executable file using Notepad. You need a compiler to convert from human-readable text into the machine language (assembly or IL) that a linker or interpreter can then execute.
You can try checking out my tutorial at http://www.icemanind.com
It is a tutorial on creating your own virtual machine and assembler, written in 100% C#.
Cyclone, I'm wondering exactly what are you trying to achieve? You say "the exact purpose of what I wish to do is rather hard to explain" and "essentially, the user inputs code, they get a .exe".
If you just want the user to be able to enter code and then execute it, you might consider an existing scripting language. VBScript is built into Windows and the language is fairly similar to VB.Net, or there are various excellent free languages you can download like Python.
If the user really needs to be able to create a .exe - I think it's likely scripting might do - then why not use an existing free compiler like FreeBasic, or even Visual Basic.Net Express Edition.
I am making a tutorial for that in my website, http://dgblogs.weebly.com. It is written with C# and you can create your own computer programming language!
You will never see this syntax in my tutorials:
Console.Readline();
My website is currently offline by now so, GOOD LUCK!
Thanks,
DgBlogs
Im quite shocked that this question was never fully answered ; Recently i came across some tutorials on the subject of developing a programming language from scratch https://www.youtube.com/c/DmitrySoshnikov-education/playlists
Although the person uses Java Script the technique used for creating the tokenizer and the parser to consume the output from the tokenizer producing the AST for the transcribed language which i would consider to be GOLD! ...
Another tutorial or person https://youtube.com/playlist?list=PLSq9OFrD2Q3DasoOa54Vm9Mr8CATyTbLF
Toby Ho! Has also produce various methods using the Nearly parser (plugin) to build a language much easier but not a Pure code coder like myself(does not like extensions to do the work which i can do myself)....
https://github.com/spydaz/SpydazWeb-AI-_Emulators
I was able to do some different experiments designing a stack machine (runs mini assembly language). for my "Toy" Programming language(basic) could be executed on. (the VM) - Using Visual Basic(My personal Lang - I think in VB)
Since revisiting the tutorials ;
https://youtube.com/playlist?list=PLRAdsfhKI4OWNOSfS7EUu5GRAVmze1t2y
Immo Landwerth! Had a few more experiments This time with C#
A bit more Spaghetti to mull over; but actually revealing (after knowing a lot more);
Yes IT is possible to design a Compiler / VM with VB.net Quite easily ... without external tools .
For myself as an AI developer (CONVERSATIONAL AI / NLP) i was interested in building a compiler for the English language if it would be possible to use the technique for parsing syntax trees and building syntax trees from text using the Tokenizer/Parser to AST Method , as well as designing the transpiler to allow for the syntax tree to be used for translation to other languages. as with today's programming languages merely being a Higher lever language interfacing with a low level(VM) language. in-fact we should be developing more natural language - programming languages and dispelling the more cryptic languages such as C# (Lol) and Java and Go and the like (so many brackets and semi colons / tabs etc - truly not needed!) and that is to say that we programmers still think in code! the journey as a AI developer crosses many domains. forces many off topic research pathways .. So Again a big YES! and we Still could say that ANy programming language can be used to create another programming language it just depends on which language you "THINK IN" .... hence not having too many languages using (i understand most programming languages - but i will always think in VB)...
Does anyone know of an alternative IDE for Sybase Powerbuilder? It feels pretty clunky, after working with VS2008 and Eclipse.
If not, has anyone successfully worked with this language outside the IDE? I'm not against using a simple text editor, but I find edit-import-regenerate-test-export-edit is clunkier than simply using the Powerbuilder editor.
To date, the only tools I have had any success with are:
PowerGen, for builds (with NUnit and CruiseControl.NET)
ConTEXT, which has syntax highlighting for Powerbuilder
PBL Peeper, which has some interesting features not present in the IDE
EDIT: I added a bounty to draw some wider attention to the question. It would be a very nice thing to have, if it exists.
EDIT: Well that was disappointing. The bounty apparently did not cause even 1 new person to look at the question.
None that I'm aware of, although you could probably use a source control tool, edit in your source control repository, and Get Latest Version from the PB IDE to shorten your text editor cycle. Be warned that there are hacks required to edit anything over 128 ASCII. (My guess is that this is to allow everything Unicode to be source controlled in the most restrictive source control tools.)
As Paul said, PB12 is coming with based on the Visual Studio shell, and will include things like collapsible code blocks, Intellisense, etc.... However, for PB12, this will only be used for WPF targets and a few .NET-type targets (like assemblies), last I heard. Win32 targets will continue to use the "classic" IDE.
Good luck,
Terry.
P.S. Thanks for the PBL Peeper compliment.
The PowerBuilder IDE is clunky, but I don't think developing completely outside the PowerBuilder IDE is a good idea. I think there are just too many dependencies right now.
However, the IDE for PowerBuilder 12 will be built using Microsoft's Visual Studio Isolated Shell so it ought to be much better when that is released. Also, I believe they'll be doing away with the PBL format which ought to make source control much easier to work with.
Certainly something to watch.
What I do is right-click the object and edit source. Then I copy the text and paste it into Notepad++ to edit. I copy and paste back to PowerBuilder, then I can save and see any errors. I've got a fairly decent User Defined Language for PowerScript if anyone's interested.
Added:
Please be aware that I've seen the PB Source editor corrupt DataWindows. They were all large DataWindows. To be safe always export DataWindows to edit.
One tool that will most probably make your PB experience way better is Visual Expert, which provides a good source browser. Such a tool should have been integrated into the PB IDE a long time ago, IMHO. Only problem is that it's not free, as opposed to the other tools you mention.
Regarding using external source editors, you can probably take advantage of OrcaScript, which is a scripting language that lets you perform actions such as export and import of PB objects from outside of the IDE. It will require some effort, but you can setup a basic dev env using batch files with ORCA scripts and some additional external tools. However, this setup will lack any visual editing capabilities, which means no (feasible) GUI or DW work. If you're mostly into NVOs, it could work. But then if that's the case, why use PB in the first place?...
I too have heard PB12's use of VS will be limited to some .NET stuff, which will probably benefit only a very small portion of the PB programmers community. I'm afraid the rest of us are stuck with the awful IDE for years to come.
Other than exporting the source and editing it I don't know of another IDE for PB. One problem you may have is that the exported source contains a lot of syntax that is not documented in the manuals. The PB IDE generates this code but there is no support for creating it by hand. I think you are stuck with the PB IDE
In my modest five Years of experiences starting with Powerbuilder 5/6, now using PB 10, I tempt to :
build my own browser from the classdefinition object based on Powerbuilder
tried to use autohotkey in order to open datawindows comfortable (we have several thousands in the project and i am two-finger-driven)
truly investigated in the idea using an external editor/IDE suppoted by an autohotkey script which is undermined by sybase allowing only mouse-click-usage of PB
using Visual Expert which is neither a truly integration in the IDE, nor is really worth in analyzing datwindow/powerscript interaction
ending by build hopes on PB12 Visual Studio, which lacks - depending on compatibility issues - ...
... i came to the conclusion that there will be no chance in improving Powerbuilder to an state-of-the-art language
In my philosophy - I obtained during those years - I distinguish between two types of OOP-oriented languages:
the one that award using object-orientation like C#, Python, Ruby (C++) etc. and very much the Java-Eclipse/Netbeans-Universe does
the other one that punish using object-orientation like Powerbuilder and the old Visual Basic, for example (which is causative the OOP-Idea comes afterwards and is "plugged in").
Especially the demand that all object should always be compiled (regenerated) and that you could't work with ancestors and descandants concurrently makes it painful to use real OOP.
...In memory of the good old Unix(Solaris)/C++ days...
I was researching a replacement solution that would be similar to PowerBuilder and I came across two that caught my eye.
The first was 'React Studio' https://reactstudio.com/ which I found via Alternativeto.net .
And the second was from an ad at the top of some Google searches but it was similar enough and looked good enough at first glance for me to want to take a closer look at it, and it's called 'Servoy' https://servoy.com/ .
Still researching but I currently have React Studio at the top of our list.
The TextPad editor has a syntax definition file for PowerBuilder 6.x contributed by anr#aon.at that I downloaded for free and customized several years ago. It works fine for later versions (including 8), doing keyword color highlighting on PowerScript srx files. Editing large source files in PB could get it to crash so it's usually safer, faster and more convenient to export to srx file, edit outside the IDE then re-import.