RFR (S): 8186787: clang-4.0 SIGSEGV in Unsafe_PutByte

[Kim Barrett]

> On Nov 29, 2017, at 8:48 AM, Erik Österlund <erik.osterlund at oracle.com> wrote:
> 
> Hi Kim,
> 
> I know how you feel about casts, and I also saw how Andrew Haley wanted a more explicit comment about why it needs to be volatile.
> To make both of you happy, I thought I'd try to make the address (addr()) in MemoryAccess volatile T*. That way I can write a more explicit comment about why it is volatile in one single place, and make you happier to not cast the address to something else than it was declared.
> 
> I hope this makes both of you happy. If not, I am okay with the old variant too, and write a comment that I copy around instead.
> 
> Full webrev:
> http://cr.openjdk.java.net/~eosterlund/8186787/webrev.01/
> 
> Incremental webrev:
> http://cr.openjdk.java.net/~eosterlund/8186787/webrev.00_01/

Sorry to be late; I hadn't noticed there was followup and a new
version yesterday until Coleen pointed it out to me.

This is okay, though I think better would be to make addr() a function
template (with a non-deducable type parameter), rather than making
MemoryAccess a class template. The point of that difference is the
principle of minimizing the dependencies between members and type
parameters of a generic class (in this case by not making the class
generic at all).