Re: Arithmetic overflow checking

From:
Tom Anderson <twic@urchin.earth.li>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 6 Jul 2011 22:32:23 +0100
Message-ID:
<alpine.DEB.2.00.1107062203220.27388@urchin.earth.li>
On Wed, 6 Jul 2011, Wanja Gayk wrote:

In article <015aeb15-57db-48ab-9cd4-
77f8448b632f@w24g2000yqw.googlegroups.com>, rop049@gmail.com says...

If I want to have arithmetic-overflow checking in all parts of an
application, what is the most practical, simple, efficient way to
achieve this? Id like to clutter the code as little a possible... Is
there any way to instruct the JVM to include it?


Not automagically, at least if you want to avoid building a sourcecode-
preprocessor or tool that instruments your bytecode at class loading
time.


Actually, a load-time bytecode manipulator might be the most practical way
to do this. Modding the JVM is a non-starter for a few reasons, using an
alternative language is not even a solution, using a library or a set of
functions by convention is error-prone, but a bytecode weaver (using the
java.lang.instrument API, to be clear) could do the job, and would be a
fairly focused way of doing it - after the fairly small amount of
boilerplate, it would just be a matter of decoding all targeted bytecode
and rewriting it to check for overflow.

I didn't say it would be easy, just focused.

tom

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