Re: Ada as a first language

["Peter C. Chapin" <pcc482719@gmail.com>]

Brian Drummond <brian_drummond@btconnect.com> wrote in
news:hhics4h0pagtf9gcc6n9bsdfh0i64atb65@4ax.com: 

> However it is something of a minority language; you will be limited in
> the support and tools you can find for it.

The AdaMagic compiler by SofCheck: 

     http://www.sofcheck.com/products/adamagic.html

has a version that takes Ada95 source and generates C. I'm working with 
a student who is using this product to write Ada for a small embedded 
system for which we only have a C compiler. The bulk of the program is 
written in Ada, translated to C using AdaMagic, and then compiled with 
the "native" C compiler. The student has had to write a few low level 
interfacing functions in C but calling them from Ada is simple 
(especially given that the Ada compiler uses C as its output language 
anyway).

In our project we are doing without the Ada runtime. We've even disabled 
languaged mandated exceptions by providing trivial stub functions (in C) 
to replace the ones usually used by AdaMagic. We are also using SPARK 
which helps us to justify this radical step. For example a program that 
obeys SPARK rules can never raise PROGRAM_ERROR due to a problem in 
elaboration order. Thus we can safely "stub out" the C function that 
does this in AdaMagic's runtime.

Anyway, this approach is actually working fairly well for us. It lets us 
use Ada in a significant way on a very small system without an Ada 
compiler. However, I'm not sure how generally applicable it is. For one 
thing without SPARK one would want to make more use of the AdaMagic 
runtime. SofCheck provides the source code for it, so porting the 
runtime to your environment (basically compiling it with AdaMagic and 
then compiling the generated C with the native C compiler) should be 
possible. I don't know how difficult it is to do because we haven't 
tried it.

I should also note that fluency in both Ada and C is desirable if one 
tries this approach. So while interesting, it probably isn't of 
immediate use to the OP.

Peter