On Thu, 02 Jun 2011 16:53:12 -0400, Nick Sabalausky <a@a.a> wrote:
I found a user comment on an MDSN Windows API reference page (Which I've
since lost, but I think it was somewhere in the Registry section.) that
claims that the Unicode-taking functions in the Windows API (or at least
some of them) require the unicode strings to be aligned on a two-byte
boundary, otherwise they might not work.
Do D's wstrings (in both D1 and D2) always follow this two-byte alignment
(provided that you're not doing any packed-alignment structs, or
cast-trickery), or is it something that we need to manually check?
Easy enough to test:
steves@steve-laptop:~/testd$ cat testalign.d
struct Foo
{
ubyte pad;
wchar wc;
}
pragma(msg, Foo.wc.offsetof.stringof);
struct Foo2
{
ubyte pad;
dchar dc;
}
pragma(msg, Foo2.dc.offsetof.stringof);
steves@steve-laptop:~/testd$ ~/dmd-2.053/linux/bin32/dmd -c testalign.d
2u
4u
So I'd say it does align to 2-byte boundaries (and dchar to 4-byte). I
can't think of a situation where the compiler would break this rule,
except for manually overridden (as you mentioned).
Note that all dynamic heap allocations are 16-byte aligned.
-Steve
