Re: Getting GNAT to issue ARM error messages

[davidp!nospam!@!nospam!syd.csa.com.au (David Peterson)]

Robert,

Thankyou for your detailed response to my earlier question regarding GNAT.

In article <79oj1f$e8p$1@nnrp1.dejanews.com>, robert_dewar@my-dejanews.com writes:
> In article <F6tqMF.Lz7@syd.csa.com.au>,
>   davidp!nospam!@!nospam!syd.csa.com.au wrote:
> > Dear All,
> >
> > Can anybody tell me if/how it is possible to make the
> > GNAT Ada compiler issue references to the Ada Reference
> > Manual rather than, or in addition to, the regular error
> > messages issued by the compiler ?
> 
> > I know that other Ada compilers such as Vertix and VADS
> > can do this
> 
> Actually the latter are the wrong comparison points, since
> these are Ada 83 compilers, and in our view the situation
> with Ada 95 is quite different from Ada 83.
> 

That is an interesting perspective. I have always considered Ada 95 as a
superset and extension of Ada 83 (with improvements and fixes), rather than
as a *new* language per se. With so much of the language common between the
two variants, I didn't consider the comparison of two Ada compilers (one 83,
the other 95) on features not related to Ada 95 language issues to be "wrong" or
unfair.

I was making the comparison on the basis of limited experience with Ada compilers
with which I am familiar.

> We only give Ada 95 RM references in rare cases where they
> are actually helpful. In our experience, most of the time
> if a well thought out error message is not clear to a user,
> then they probably do not have the level of knowledge
> necessary to benefit from going to the reference manual.
> 

Hmmm ... I thought that the rationale should be that if an error message is not
clear, you should be able to reference some document to clarify the situation.

The solution above assumes that all error messages are clear and well thought out
(which may be true!), and that all the required information can be communicated in
1-2 lines of console output (which I find hard to believe).

Also, I think that the majority of people developing software in Ada *do* have the
intellectual capability and educational background to read the reference manual,
which might not be the case in other languages such as C / C++ (a more diverse
user base).


> We prefer to work on making the error messages as clear as
> possible to someone who is NOT a language expert and NOT
> comfortable reading the reference manual. That is the goal.
> 
[cut]

I certainly accept that, and find GNAT a great compiler to work with. The error
messages are clear and concise. However, I do believe that the majority of people
developing software in Ada are serious enough programmers to be comfortable
reading (or at least attempting to read !) the ARM. 


> 
> We do NOT think that adding RM references would help in
> the goal of continued improvement of GNAT messages.
> 
> 

My only comment would be that the addition of a switch or option to toggle the
issuing of ARM references in addition to the current set of comments would
add flexibility. Those that wished to obtain additional information regarding
an error could toggle the option, with the compiler responding with the additional
information as required.

I agree that in general ARM references can clutter up the error output, and that
well thought out "plain english" messages are often preferable to ARM text - but
surely access to both would be the best solution ?

Again, thanks for your time and comments, and for answering my original question
regarding the availability of such a feature in GNAT.

Just thought I'd add a few comments (above), but I am certainly not inclined to
tread old ground over and over, nor to start a "holy war" on the issue of comments
in GNAT ! :-) It's a good compiler, and I'll take it as it comes ...

Regards,



David Peterson