Re: Ada's ranking of popularity at IEEE Spectrum

[Brian Drummond <brian@shapes.demon.co.uk>]

On Sun, 06 Jul 2014 20:17:47 -0500, Nasser M. Abbasi wrote:

> On 7/6/2014 7:17 PM, Simon Clubley wrote:
> 
>> You can't do that until you have Ada compilers which are as widespread
>> as C.
>>
>> Simon.
>>
>>
> Sorry for basic question, but I thought Ada is now part of gnu gcc (gnat
> compiler)
> 
> https://gcc.gnu.org/wiki/GNAT
> 
> And I thought that this mean that everywhere there is gnu gcc, there
> will be Ada as well? And since everywhere there is gnu gcc as given in
> this list:
> 
> https://gcc.gnu.org/install/specific.html
> 
> There will also be a c compiler, then why would Ada be less available
> than C compilers?

Because most people building gcc use the configure option
--enable-language-=c,c++
instead of
--enable-languages=c,c++,ada

And most of the binaries for most of the distros are built that way. Ada 
is offered as an optional extra if you already know about it and 
specifically ask for it - AND it isn't simply missing

The situation is worse where cross-compilers are concerned : very few 
targets (AVR, occasionally Arm, and (new official target with gcc4.9, and 
not yet satisfactorily MSP430) are checked with --enable-languages=c,c+
+,ada. I may have missed some; if so, they don't get enough publicity!

So you have to build your own. Then gcc's build process is messy, 
frustrating and buggy as hell, and only the most trodden paths are 
relatively clear of bugs. (To the extent that people off the path who ask 
questions are usually simply told : get back on the path and start 
again). Turning on Ada support takes you off those paths into the weeds, 
and you will find build failures and bugs you have to wade through to 
even get the thing to compile. 

At this point I must say I am impressed with Peter Bigot's old 
unofficial"mspgcc" front end; it was remarkably trouble free.

If you bought or downloaded a set of commercially available tools for 
your FPGA (cough Actel/Microsemi) they won't even supply source (though 
it's a well known gcc distribution) and you have to dig it up from the 
Mentor Graphics website and build it yourself. (This specific target I 
haven't tried yet)

Then having a working compiler you find that you have only just started.

In contrast to C builds of gcc where the process tidily accommodates libc 
and libgcc because other people have set it all up for you - either the 
Ada RTS won't build for your target or there is no Ada RTS at all, and 
you have to create one from scratch. (for the MSP430 I adapted the 
minimal one from the AVR-Ada project. It works well if you don't need any 
tasking features)

> Isn't gnu gcc available everywhere? or may be the gnat part of gcc is
> not available everywhere like the c compiler part of gcc is?

So ... yes, gnat is available for a suitable definition of available. In 
practice, no...

At this point Ludovic's  "put up or shut up" (paraphrasing Dan'l) 
applies ... if each reader picked one small area and moved it forward, at 
least people would see SOME Ada happening. We have to start the snowball 
somewhere.

- Brian