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> Date: Sun, 21 Feb 2010 22:41:46 -0800 > From: andrew@farwestbilliards.com > To: debian-user@lists.debian.org > Subject: Re: Decompiler? > > On Mon, Feb 22, 2010 at 05:11:07AM +0000, Hadi Motamedi wrote: > [... snip nice explanation of why this won't work...] > > > So I dis-assembled the code and I was lucky to find the related > > subroutine . It is short in length but I cannot decode it to find the > > logic in behind . So I need to find a de-compiler to de-compile it to > > some sort of higher level languages to see if I can understand the > > login behind . Please give me a hint on how to accomplish this . > > basically it can't be done. It's a one-way operation. Picture this -- > within C there are several ways to print a value to the screen. These > all likely produce similar machine code where a register is loaded > with the address of the value t o print and then a print routine is > called. The question when decompiling is: how do you know *which* > method of printing a string to decompile to? You can't know. Throw in > the fact that code and data are indistinguishable at the machine > level, and it's basically impossible. Now remember that there are many > many many languages that compile to machine code. How do you even know > which language it was originally written in? What language do you > target for the decompilation? > > The transformation of high-level code into machine code is not an > isomorphism. It cannot be reversed. > > That said, there my be ways to make some reasonable guess as to what > the code is doing and de-compile to some psuedo-language, but this > will still largely be guesswork. If you can make it work even remotely > reliably, you could probably get a PhD for the work... > > A Thank you for your reply . The dis-assembled code is in x86 assembly language and the original code in written with c++ running on my Debian server . Can you please let me know if it can helps finding a dis-compiler to have some sort of higher level language code to see if I am still lucky to find the logic behind ? Hotmail: Powerful Free email with security by Microsoft. Get it now. |