Re: Ada95 Strengths/Weaknesses.

[Robert Dewar <robert_dewar@my-deja.com>]

In article <7spauv$a2g2@news.cis.okstate.edu>,
  dstarner98@aasaa.ofe.org wrote:
> Check. I just recently hand converted a small game from C++ to
Ada using
> G++ and GNAT respectively. The only changes besides that were
going from
> 0 based indexing to 1 based, and dropping some debug code in
the process.
> g++ *.cpp -o Alexis produces a binary with a size of 15,796
bytes. gnatmake
> alexis-char produces a binary with a size of 735,962 bytes.

Obviously an apples-vs-oranges comparison

>Some tweaks later
> (dynamic linking, no runtime checks, striping the files)

These are not tweaks, they are major changes!

produces a C++ binary
> of 12,568 bytes and an Ada binary of 51,124 bytes.

Comparing the minimum sizes of trivial programs is not a
terribly interesting operation, since it has almost nothing
to do with real programs, but in practice if you really want
to do it carefully, you can get the identical Ada and C++
object files. Of course you have to use identical libraries,
not just corresponding ones, because the libraries in C++
and Ada definitely do not correspond.

If you really want to waste more time tweaking, you might
want to try pragma No_Run_Time and eliminate the GNAT runtime.

But almost certainly you are still comparing apples and oranges,
and the comparison is not particularly interesting.


 Stripping
out the random
> number library I had used from Mat Weber's Components (which
cripples the
> program,

wait a moment, I thought you said the two programs were the
same. Surely the C++ program did not use Mat Weber's component?
You really have to compare identical things here. For example,
the requirements on the random number generator in Ada are
quite ferocious, much more so than in the case of C++. You need
to use identical library routines to do a size comparison like
this.

> but to be fair Mat Weber says it's redundant with
> Ada95, so I could
> probably remove it if I knew how) brings us down to 32,196,
over twice the
> size of the original.

But almost certainly it is not comparable to the original. If
you like post the two pieces of code you compared. Quite often
such postings reveal huge misconceptions in what is and is not
comparable between the two languages.

> So, since GNAT is junk, do you have another Ada compiler to
> recommend?

I don't think you need a new Ada compiler, I think you need more
understanding about how to do a comparison like this in a
meaningful manner.



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