Re: HPUX C++ ABI

[Mark Mitchell <mark at codesourcery dot com>]

--On Thursday, September 12, 2002 02:15:10 PM -0400 David Edelsohn 
<dje@watson.ibm.com> wrote:

> > > > > > Mark Mitchell writes:
> Mark> There is a slippery slope argument that "everyone else will want us
> to Mark> support there variant of the ABI too".  But, there is no
> everyone else; Mark> HP is the only vendor with an installed base that
> does not feel they Mark> can make changes to their ABI.
>
> 	I think this is a bad precedent unless we really want to open the
> doors for compatibility patches from every other compiler vendor.  Are we
> going to allow patches of this type from compiler vendors who ABIs happen
> to be similar to G++'s ABI, but not from others?
That is the point of my statement above; this hypothetical is uninteresting
because there are no such vendors -- and there aren't likely to be any in
the near future.

But, if there were (or come to be) other OS vendor compilers that almost
support the ABI, I would probably support being compatible with them too,
subject to the same caveats I gave for HP.

> 	Why can't HP's aCC compiler have a -compat-g++ switch?
I definitely think that to be a good idea, but it's not the real point.

The point is that the  aCC ABI is the vendor ABI on the platform; if
we want G++ to be able to work with C++ libraries on HPUX, we need to
do be compatible with aCC.

This situation is roughly analagous to an OS that almost -- but not
quite -- implements the C psABI for x86.  Suppose, for example, that it
passed arguments in the wrong registers, but otherwise did things
according to the spec.  We'd probably accept patches for compatibility
with that OS.

--
Mark Mitchell                mark@codesourcery.com
CodeSourcery, LLC            http://www.codesourcery.com