Re: Executable File Size Differences

[ok@goanna.cs.rmit.edu.au (Richard A. O'Keefe)]

Stanley Allen <sallen@ghgcorp.com> writes:
>I am not convinced that current Ada compilers could be used to
>produce code for "major" PC software that would have acceptable
>memory performance.  I'm thinking of full-featured products,
>products that compete in the cut-throat PC software market at
>the top echelons, where "feature-itis" issues are critical to
>commercial success.  Products like WordPerfect, Netscape
>Navigator, and Microsoft Access.  Could Ada be used to develop
>commercially successful products in this arena?  I don't think
>so.

I took Netscape off my Macintosh Centris 660AV because
- it swiped half of the machine's 16Mb memory for its own use
- and could be relied on to trash the other half.
Maybe if Netscape had been written in Ada I could have afforded
to keep on running it, but I have better things to do with my
time than reboot a Mac every couple of hours.
Now when I run Netscape (which is when Mosaic has trouble) I run
it through a terminal emulator window and just delete the occasional
"core" file.

When you are up around the 8Mb memory size (and I assure you, that
really truly is the amount of memory Netscape wanted), the run-time
library size is irrelevant.

>I think the executable speed of the code produced by current
>Ada compilers is up to snuff.

More than!  When anyone tells me "I'm not going to use Ada for this,
I'm going to use C for efficiency" I laugh at them.

>But I *don't* believe
>that the size of the executables produced by the linkers, and the
>amount of RAM necessary to run these executables, is currently
>acceptable for producing products in the above-described arena.

The trouble with this is that while you may very well have grounds
for your statement, we don't know that unless you tell us.
- How many Ada compilers have you checked the current versions of?
- Which platforms?  Just the PC, or the Mac as well, or UNIX (which)?
- Which kinds of applications have you measured?

For what it's worth, I note that the Encore Multimax "Pascal-2" compiler
generated executables containing only the subprograms reachable from the
main program, _without_ a "smart linker" provided by the operating system.

>The problem is an old one: the lack of "smart linkers" which
>would include only the necessary code from an Ada package, and
>avoid linking in the unused bulk that never gets invoked.

C doesn't have this either, nor do any of the C++ compilers I have used.

In fairness to UNIX (and other) linkers, there is nothing in COFF or ELF
that says a compiler cannot generate a "lib.a" file instead of a "lib.o".
The DOS loaders can handle library files of some sort too.

>But in a large office complex with 100+ PC, careful thinking
>must be given to purchasing a new WWW browser that would
>require bumping everyone's RAM up by 8Mb or more.

Ah.  So you _don't_ use Netscape.  /opt/local/sun4/bin/netscape.bin
is protected so I can't use "size", but "ls" says it's 4.2Mb,   Dear
knows how much data space it needs.

>Smart linking is an simple idea which is hard to implement.

If Encore Pascal-2 could do it, it _can't_ be hard.

-- 
Australian citizen since 14 August 1996.  *Now* I can vote the xxxs out!
Richard A. O'Keefe; http://www.cs.rmit.edu.au/%7Eok; RMIT Comp.Sci.