Steve's comments moved from issue 106:
1. Is pointing to one element past the end of a shared array object valid (as
it is for local objects by ISO/IEC 9899 6.5.6 8-9)? If so, we should be sure
that we get the expected behavior for those as well. Note that this is a much
larger change, as a lot of the spec assumes that any valid non-null
pointer-to-shared points to an object.
This is trivial to express. The existing equations in 6.4.2 3 define the exact
behavior of upc_threadof() and upc_phaseof(). My proposal in comment 13
suffices to define the behavior of upc_addrfield(), and can be trivially
tweaked to define the local address as well. Since you can't do
pointer-to-shared arithmetic on generic pointers-to-shared, nor on
pointers-to-shared whose referenced type is incomplete, we don't need to worry
about what "one past" means in those cases, and it is well-defined for all
others.
Original issue reported on code.google.com by
danbonacheaon 1 Mar 2013 at 6:25