Re: [Boost-build] acc and address-model

Subject: Re: [Boost-build] acc and address-model
From: Vladimir Prus (ghost_at_[hidden])
Date: 2009-03-31 15:31:21

On Tuesday 31 March 2009 23:26:29 Jim Gallagher wrote:
> >
> >Hi Jim,
> >
> >it's not very surprising -- I don't think any Boost.Build developer
> >uses acc daily, or even have access to it, so the only fixes that get
> >added are those where a user told what to do.
> >
> 
> Volodya,
> 
> I guess I was surprised because HP touts that they test aCC by building
> boost, and contribute back as appropriate. Either they are not testing 64
> bit builds, or they are not contributing back to boost-build as they should
> :-)

They might be testing in 32-bit mode, but I don't know any details.

> >While I was adding this I've noticed commented-out line to add -Z option
> >when building shared libraries. Do you happen to know if that option
> >is needed or desirable?
> >
> >- Volodya
> >
> 
> I think the option is really +Z. This is required when compiling code for
> shared libraries on PA-RISC. I believe I was the one asking about this last
> year. PA-RISC is dying; HP no longer sells PA-RISC Unix boxes, only Itanium.
> Recent PA-RISC boxes leave HP's normal support window in 2013.
> 
> Here is the excerpt from 'man aCC' on a PA-RISC box regarding +Z:
>       +z,+Z          Cause the compiler to generate position independent
>                      code (PIC) for use in building shared libraries.  The
>                      option -G is ignored if used when generating PIC.
>                      Normally, +z should be used to generate PIC; however,
>                      when certain limits are exceeded, +Z is required to
>                      generate PIC.  The linker ld(1) issues the error
>                      indicating when +Z is required.  The default is +Z when
>                      +DA2.0W is specified.  If both +z and +Z are specified,
>                      only the last one encountered applies.  For a more
>                      complete discussion regarding PIC and these options,
>                      see HP-UX Linker and Libraries Online User's Guide and
>                      the manual Programming on HP-UX.
> 
> I've never hit a snag using +Z instead of +z.
> 
> The -Z option allows dereferencing of null pointers.
> 
> aCC on Itanium does not support +Z. All objects appear to be PIC.
> 
> One other thing that was a problem on PA-RISC with respect to boost-build is
> that shared libraries have a .sl extension, as opposed to .so. If I remember
> correctly, I hacked in support for the .sl extension, but we never exercised
> it.
> 
> We have since moved to Itanium servers, so the +Z and .sl issues are
> probably moot.

Ok, less work for me. Just to clarify -- is PIC the default on Itanium? If
not, I guess we still have to add +Z

- Volodya