D vs Java

[pragma]

In article <dvrrca$103i$1 at digitaldaemon.com>, Don Clugston says...
>
>In digitalmars.com digitalmars.D:35128, Walter said of the difference in 
>reals between Linux and Windows:
>
> > > pragma's DDL lets you (to some extent) mix Linux and Windows .objs.
> > > Eventually, we may need some way to deal with the different padding.
>
>I think it's a pipe dream to expect to be able to mix obj files between
>operating systems. The 96 bit thing is far from the only difference.
>

I read Walter's remark, and it came to me like a shot from the blue.

>Now, he's quite knowledgeable, but I'd love to prove him wrong on this 
>one. I find it hard to believe that it would be impossible. I guess the 
>question is, will the subset of functionality that works be sufficient 
>to be useful? I guess we won't know until the ELF side is working.
>
>"Compile once, run everywhere that matters"? (Win, Linux, Intel Mac).

Pipe dream or not, I think its worth looking into.  And you're right: the
portable subset of features may be just barely usable.  Until we get some people
really pounding away on this, we'll never quite know.

>Exception handling (especially Windows SEH) might be a big problem, 
>maybe a show stopper?

I must confess: I don't know enough.  The 96/80-bit real thing is one issue, and
if the D ABI doesn't specify what the exception mechanism is, then that becomes
vendor/platform specific too.  Is there anything else?

I suppose I made the mistake of assuming that the D ABI was to become more
encompassing than what it presently is.  My understanding was that D aimed to
fix things on a binary level as well as in the sourcecode.  After all, C/C++
doesn't have a strong ABI and suffers directly because of it.  It would be nice
if we knew exactly what was left up to the compiler writers and what was not -
at least then one could make some solid reccomendations for this mode of
development.  :(

- EricAnderton at yahoo