Re: Elaboration order

[stt@henning.camb.inmet.com (Tucker Taft)]

Ken Garlington (GarlingtonKE@lfwc.lockheed.com) wrote:
: Chris McKnight wrote:
: > 
: >  LRM References?  Hmm..  how about (taken from ANSI/MIL-STD-1815A-1983):
: > 
: >    7.3  paragraph 4 :
: >       "The elaboration of the body of a subprogram declared in the visible
: >        part of a package is caused by the elaboration of the body of the
: >        package.  Hence a call of such a subprogram by an outside program
: >        unit raises the exception PROGRAM_ERROR if the call takes place
: >        before the elaboration of the package body"

: So what does this mean in the following case:

: package Another_Example is

:   function Initial_Value return Integer;

: end;

: package body Another_Example is

:   function Initial_Value return Integer is begin return 0; end;

: end;

: with Another_Example;
: package Use_Example is

:   X : Integer := Another_Example.Initial_Value;

: end;

: Can I get a Program_Error on the initialization of X? If so,
: it would seem like there would need to be a pragma
: Elaborate for nearly every reference to every package
: exporting a subprogram!

You only need a pragma Elaborate[_All](pkg) if you call a subprogram 
from "pkg" as part of the *elaboration* of some other package.

If the calls only appear in subprogram bodies, rather than at
the package level, you shouldn't have any problem.

-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
Intermetrics, Inc.  Cambridge, MA  USA