Re: The Dreaded "Missing Subunits"

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Emmanuel Briot <briot@act-europe.fr> writes:

> Peter Amey <peter.amey@praxis-cs.co.uk> writes:
> 
> > Are you really using the GNAT compiler with Rational naming
> > conventions?  I don't know if that is the cause of your problem but it
> > certainly won't help.  Rational (rather bizarrely in my view) use
> > xxx.1.ada for specs and xxx.2.ada for bodies.

I'm not sure why Peter thinks this convention is bizarre.  In fact, it
has some nice properties.  I think the Rational convention is quite
rational indeed.  For example a simple wildcard can be use to select
interesting files, like "all the Ada source code in this directory",
"all the specs", "all the bodies", "the spec of package X and all its
children", "the specs and bodies of X and all its children".  And when
you list them in alphabetical order they come out in a sensible order
(specs before bodies, parents before children).  So for example if I
print out "*.ada" I get a stack of paper in a sensible order for
reading.  With the GNAT convention, things come out in the wrong order.

>...  The GNAT convention
> > (which automates builds) is to use:
> > 
> > unit_name.ads for specs, unit_name.adb for bodies and
> > grandparent-parent-unit_name.adb for subunits.
> 
> This is of course wrong. 

True.  GNAT can be told to use the Rational convention, and works just
fine.

However,...

>...Have a look in the documentation at pragma
> Source_File_Name, which provides handling for any possible naming scheme you
> can conceive.

This is also of course wrong.  The patterns supported by the pragma are
fairly limited, but I can "conceive" of many things.  For example, if
you want to put all main procedures in files with a certain pattern, it
doesn't really work.

The sad thing is that although Ada is very portable in many respects,
the community of compiler vendors can't agree on file-naming
conventions.  Contrast with C, where everybody knows what .h and .c
mean.

- Bob