Comparing class files for equivalence

Thread view:

Mahmoud Abdel-Fattah - 14 Sep 2005 12:16 GMT

I have a group of class files that were apparently compiled with two
different compilers, and I want to know if these files were compiled
out of the same source files. I tried decompiling them with jad, but I
found a lot of differences in the decompiled source code that do not
eventually change the logic behind the code. Is there a way somebody
may suggest to test two groups of classes for having equivalent logic?
Are there any tools that do equivalence checking of two classes?

Thank you.

Reply to this Message

Roedy Green - 14 Sep 2005 21:24 GMT

>I have a group of class files that were apparently compiled with two
>different compilers, and I want to know if these files were compiled
[quoted text clipped - 3 lines]
>may suggest to test two groups of classes for having equivalent logic?
>Are there any tools that do equivalence checking of two classes?

What happens if you decompile them both and recompile them with the
same compiler, say JET which might optimise out the minor differences.

Signature

Canadian Mind Products, Roedy Green.
http://mindprod.com Again taking new Java programming contracts.

Reply to this Message

Mahmoud Abdel-Fattah - 19 Sep 2005 10:48 GMT

Thanks for the response. I have a problem that makes your solution too
hard, which is that there are too many inner classes. The decompiler
outputs the inner classes in separate source code files, and merging
them into the original code is a very time consuming process. I wonder
if there is another solution to the problem.

I heard about equivalence checking tools used in hardware design. I
wonder if similar tools exist for software development.

Reply to this Message

Comparing class files for equivalence

Free Magazines