Re: Classpath build process and VM-specific issues

[Etienne Gagnon]

Andrew Haley wrote:
> Okay, but ANS specifically does not allow you to do this subtraction.
> Also, there is no guarantee that every pointer is representable as a
> ptrdiff_t.  (6.5.6 Para 9, if you're interested)

The point is: if your platform is one that does *not* have 8-bit chars (!!!),
then you can simply rewrite the appropriate code to put some bit representation
of your pointer into a jbyte array (using whatever trick you need), and the only
 place where you would have to do it is the the wrap/unwarp functions.  No
modification on the Java side.

MORE IMPORTANTLY: As long as your platform has 8-bit chars/bytes (99,9%),
[and that no crasy person decided that on such platform jbyte would be
different from signed char!!!!], then my proposed code will just work
out-of-the-box, and be quite efficient (for JNI code).

Comment: Now that you raised 6.5.6 para 9: how do you intend to cast such
pointer to a jlong, in your proposal?  [ironic]

OK. Let's stop splitting hairs in half.  I have showed you a valuable and
practical proposal.  I'd like to see your full proposal, JNI part included.

Etienne

--
Etienne M. Gagnon, Ph.D.             http://www.info.uqam.ca/~egagnon/
SableVM:                                       http://www.sablevm.org/
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