Re: SAMBA for VMS (The saga continues!)

From: John Malmberg (malmberg_at_dskwld.zko.dec.compaq.hp)
Date: 08/17/05 

Date: Wed, 17 Aug 2005 16:08:10 GMT

Steven M. Schweda wrote:
> From: John Malmberg <malmberg@dskwld.zko.dec.compaq.hp>
>
> This compile-'em-if-you-need-'em scheme seems to me to do the job
> just fine without the need for any funny names.
>
> Why does the use of the funny names constitute "The correct fix"?

Because it is the only way to prevent conflicts with the compiler
optimizer and with shared images that may be loaded on any platform.

This is the case on some modern UNIX platforms and especially on OpenVMS
where compiling with optimization on is the norm, and so is using shared
images instead of object libraries.

I have not bothered to keep track of which UNIX systems require this
behavior.

It is only if you are using only object libraries and specific linking
instructions and also disabling the compiler optimizer that you can rely
on the original UNIX behavior of overlaying operating system supplied
routines with ones in your program that are in separate modules.

The routine names in X/OPEN Single Unix Specification at
http://www.unix.org/single_unix_specification/ need to be treated as if
they were reserved names as far as global routine names are concerned.

Or you may not get the result you thought you were getting even on UNIX,
even if you are not getting compile or link errors, if you were
intending on having a routine do something different than the standard
routine with the same name.

Accessing the information about the routine names from X/Open web site
requires a free registrations and apparently the acceptance of cookies.
  They do sell copies of the specifications for those that want the
information but not the cookies.

As OpenVMS improves their compliance with the X/Open UNIX specification,
it will cause more problems with routines that are using these names as
global symbols.

These improvements may come in ECO kits in addition to OpenVMS upgrades.

So unless you want your source code or object modules to quit working
with each improvement with the VMS CRTL in UNIX compliance, you will
want to avoid using routines with the same names as in X/OPEN, even if
they are not currently available on OpenVMS.

Executable images will continue to work as the symbol conflicts are a
compile/link time issue.

And if you want your code to work properly on a wide variety of UNIX
like systems you will also want to follow the same practice.

-John
malmberg@dskwld.zko.dec.compaq.hp
Personal Opinion Only

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