[lsb-discuss] LSB and the GNU build system

[Dallman, John]

Theodore Tso [mailto:tytso at mit.edu] wrote: 

> The first is that is GNU build system is too low-level to deal 
> with LSB compliance issues. ... making LSB-compliant libraries 
> is a lot more than just using a different compiler toolchain.

OK, that answers the question. 

> With LSB 4.0, we will be shipping a new LSB SDK that should make it
> easier to use and integrate into existing build systems, and so what I
> would suggest doing is to make plans to start next year to use the LSB
> SDK (which is basically a set of wrappers around gcc and ld, plus a
> set of header files and other configuration files) instead of using
> the GNU toolchain directly.

OK. The stuff I work on, because it is basically math libraries, is
already built with the LSB 3.1 SDK. But that's only a small part of 
the company's products.  

How thoroughly will LSB 4.0 support linking in shared libraries that 
are built with LSB 3.1? 

Will it be possible to install the 4.0 and 3.1 SDKs on the same 
machine and use the appropriate one in a script by setting up 
environment variables, or will it remain one SDK per machine?  

> It may be that for your company the transition to using the LSB 
> is something that will have to be done gradually, 

Definitely. There is a lot of code in the products that is not 
LGPL, but proprietary, and while that's built with GCC on Linux, it
is not built with GNU configure, et al. There's also code that 
will likely never be LSB-compliant, because it uses Motif, and 
the people who work on it aren't interested in changing to another
implementation of Motif just for LSB compliance. Yes, I know the 
reasons for LSB not including Motif. I'm having to work this idea 
in gently and in stages.  

> One thing to point out to your managers is that very often there are
> incompatibilities between Windows 98, ME, XP, 2000, and Vista, even
> for applications that only try to restrict themselves to the Win32
> API.  And of course, it's very easy to accidentally use some new
> interface in Windows which only works on newer Windows systems.

Ah. We make big, heavy pieces of CAD and PLM software. We never 
supported Windows 9x; we do our builds and tests on the oldest 
version of Windows (currently XP) that is supported. That strategy 
provides considerable protection from the vagaries of Microsoft. We 
work in a similar way on AIX, Solaris, HP-UX, et al. People are very 
used to that kind of way of working, and I still have to explain from 
time to time that asking what version number of Linux something
is isn't a meaningful question. 

> Microsoft; observe what happened to Adobe when without warning
> announced that they were dropping the 64-bit Carbon APIs from Leopard

Err, you mean Apple? 

> The one thing I would add in conclusion is that it's great that you
> are asking these questions, and if you are interested in a few months
> when we have some initial versions of these tools that would be ready
> for a beta-test, it would be great if we could include you on the beta
> program, and get back your feedback about how easy it is to replace
> the use of the raw GNU toolchain with the LSB toolset.  We also have a
> pre-release version of the next version of the Linux Application
> Checker which may be useful as you are trying to determine how
> cross-platform portable your applications and libraries are, and what
> you might need to do to improve their portability.

I'd like to say yes, but I doubt I can. I haven't been able to motivate 
the other groups strongly about LSB, because of the Motif issue: they 
largely regard the incompatibilities between versions as Linux bugs that
Linux needs to fix. I still have to explain, for example, that the 
incompatible change from libstdc++.so.5 to libstdc++.so.6 is not a bug, 
but a deliberate change, and is not going to be fixed. 

The company is not doing Linux because it wants to do Linux. It's doing
it because customers want to run its products on Linux. And while the 
customers don't ask for LSB, and LSB has limitations like Motif, LSB 
doesn't get much traction. 

-- 
John Dallman
Parasolid Porting Engineer

Siemens PLM Software
46 Regent Street, Cambridge, CB2 1DP
United Kingdom
Tel: +44-1223-371554
john.dallman at siemens.com
www.siemens.com/plm