Re: Are there any tools that can compare two source files

Sarath Kumar <sarath_kumar@mentorg.com> wrote:
>
> Generalizing the problem refers to the problem of finding the
> semantic equivalence of two programs. Is this possible??


No. It's not decidable.
If this were possible, one could wrap any program in a function call
that throws any results away and ask whether it's equivalent to a
program that does nothing; this would solve the halting problem.


Of course, if the two programs are sufficiently similar, it might still
be possible to get useful results (as John noted). The problem here is
that this type of semantic analysis and code transformation requires an
*exact* understanding of the language semantics. I wouldn't want to do
this for languages that do not have a formal semantics (needless to say
that many of the more popular languages don't have such a thing).


Regards,
Joachim

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