Re: Should Inline be private in the private part of a package spec?

["Randy Brukardt" <randy@rrsoftware.com>]

"Robert A Duff" <bobduff@shell01.TheWorld.com> wrote in message 
news:wccr4rkqed5.fsf@shell01.TheWorld.com...
> "Randy Brukardt" <randy@rrsoftware.com> writes:
...
> If you like, show us an example of one of these "fails to link"
> cases.  Or don't bother -- it's really not that important.

Well, I don't want to waste more time on this, but I'm annoyed enough that I 
will.

First, we're talking about a compilation dependence here, not an elaboration 
or semantic dependence. That's not defined formally by the Ada 95 language, 
but of course it's necessary to any implementation. (I believe it was 
formally defined in Ada 83.)

Anyway, consider:

   package P is
      function F return Boolean with Inline;
   end P;

   package body P is
      function F return Boolean...
   end P;

   with P;
   procedure Q is
   begin
      if P.F then ...
   end Q;

Here, Q has a compilation dependence on the body of P. If the body of P is 
recompiled, then Q also has to be recompiled. If it is not, then the program 
must not be allowed to link. (That would be a violation of 10.1.4(5)).

Also note that 10.1.4(7/3) talks about "removing" compilation units that 
contain calls on inlined units when a new copy of the body is added (and 
"preexisting versions" of the body are removed). This has the effect of a 
compilation dependence.

(For Janus/Ada, we don't "remove" units, but we do refuse to bind units that 
contain references to old versions. I've always presumed that that was a 
correct implementation of these two rules.)

IMHO, compilation dependences should be given in the visible part of the 
package (preferable in the context clause), so that the 1% of Ada 
programmers that compile files by hand can accurately find the dependences. 
Requiring the use of implementation-defined tools like GNAT's Gnatmake or 
Janus/Ada's COrder is obnoxious. Thus "Inline" needs to be given in the 
visible spec.

If 10.1.4(7/3) didn't exist, then Inline would not need to be given in 
visible spec. But as I noted elsewhere, I don't think Inline should be given 
anywhere -- compilers can figure out when to Inline better than any human 
can. Hints about the amount of space expansion allowed for the entire 
program and the relative importance of particular subprograms would be much 
more valuable.

                                                   Randy.