Re: Reducing VMS Ada .exe sizes... How?

[stluka@software.org (Fred Stluka)]

In article <91134.084320PHALL@ESOC.BITNET> PHALL@ESOC.BITNET writes:
> you don't really say what the exact problem is, however if the problem
> is that the image size is very large ...

Yes, the problem is that the image size is huge (7500 blocks),
wasting space on disk and time at image activation.

I suspect that a major contributing factor is that lots of 
stuff which is in packages I reference but which I don't ever
use is being included in the image.  I suspect that the linker 
always links in an entire object module, regardless of how
much is needed to resolve all references.  Thus an Ada package
containing many routines, or a C file containing many functions,
is always completely included in the image, even when many of 
the routines are never called.  Once these rouitnes are included,
then other routines which they reference (but which I also never
call from my code) must also be included, and so on.

Therefore, my question to the net was how to prevent these routines
from being linked into the image.  I am still interested in an 
answer to that question, but other tips like the one below are 
also appreciated.

> ... then check the linker map to see
> how many modules are being linked. if this value is approx 96 it is likley
> that the linker has stopped performing demand zero compression.
> the linker option ISD_MAX specifies the maximum number of image sections
> allowed in an image. The default is approz 96. If the total number of
> image sections reaches or exceeds this value, demand zero compression stops.

What is demand zero compression?  Are you saying that pages which
are entirely zero-filled are stored that way on disk in the image 
instead of being generated dynamically during a page fault, if the
image has more than 96 or so sections?

--Fred
-- 

Fred Stluka                              Internet: stluka@software.org
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