Re: Decompile...

["Mike Lerwill" <mike at homemjl dot demon dot co dot uk>]

Of course you are correct it can be done the real question is how well.

See http://www.teknema.com/~cg/work.htm
 
for an idea of the work being done in this area.


-----Original Message-----
From: Fred Reimer <Fred.Reimer@bellsouth.net>
To: tolj@uni-duesseldorf.de <tolj@uni-duesseldorf.de>; Marcel R. <marshall@cwb.matrix.com.br>
Cc: gnu-win32@cygnus.com <gnu-win32@cygnus.com>
Date: Saturday, July 11, 1998 11:37 PM
Subject: Re: Decompile...


>I don't know about this.  I've thought of it many times in the past, and I
>don't see a reason why it can't be done.  Obviously, it's possible to
>disassemble an exe.  The asm that compilers create usually have to adhere to
>specific standards so that the resulting code can be linked with other
>vendor's libraries, etc.  Windows code has additional "restrictions" over
>and above what the standard C standard has (and I mean the linking standard
>that everyone uses, not necessarily in the C "standard").
>
>I would think that it would be possible to create cryptic C code for an exe
>that at least shows the types of variables passed between functions and the
>auto variables used within the function in addition to the general flow of
>the function.  If you backtrace from calls to the Windows API, you can
>extrapolate what types of structures are passed from the user code.  Of
>course, all the variable names would be pretty meaningless, unless whoever
>made the exe left the symbols in it.  But Windows may make it simpler, with
>it's "standardized" variable naming system (i.e., lpszString1).
>
>I don't mean to make it sound easy, but I don't agree that it's impossible,
>just impractical
>
>
>-----Original Message-----
>From: Stipe Tolj <tolj@uni-duesseldorf.de>
>To: Marcel R. <marshall@cwb.matrix.com.br>
>Cc: <gnu-win32@cygnus.com>
>Date: Friday, July 10, 1998 6:21 AM
>Subject: Re: Decompile...
>
>
>>Marcel R. wrote:
>>>
>>> Hi 4 all...
>>> I want to know if there is some way to "Decompile" a file... I mean, get
>a
>>> exe file and make it be a cpp file, and view the code to do some things
>>> that the program do...
>>> Thanks...
>>
>>no way. A binary (exe) file consists of assembler instructions for the
>>cpu. Their is no way to "decompile" the compiled and linked file to an
>>source code file, since the function f: source -> binary is not
>>injective so say it in mathematical terms.
>>
>>The only way to find out "what" a binary file does is to disassembler
>>it, and perform aseemlber instructions step by step, controlling the cpu
>>registers and assembler registers that change within execution of the
>>analyzed program.
>>
>>PS: If it would be possible to "decompile" exes to source code files, I
>>would be the first to "decompile" windows 98 and modify a bit to sell it
>>under an other name.
>>
>>Regards, Stipe.
>>
>>--
>>stud.rer.pol. Stipe Tolj <tolj@uni-duesseldorf.de>
>>HTTP Server Development Management
>>Department of Economical Computer Science
>>University of Cologne, Germany
>>http://www-public.rz.uni-duesseldorf.de/~tolj
>>
>>
>>-
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>
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