[Bug ada/65524] gnatbind generates decrementing the unexisting elab-counter into finalize_library

[charlet at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65524

Arnaud Charlet charlet at gcc dot gnu.org changed:

   What|Removed |Added

 Status|WAITING |RESOLVED
 Resolution|--- |INVALID

--- Comment #3 from Arnaud Charlet charlet at gcc dot gnu.org ---
Using a custom runtime change isn't supported by GCC FSF.
I suspect the fix if any would be to geenrate the _elabs routine rather than
trying to patch the binder, but as you are using a customized runtime, there
might
be other issues at play and the simplest is for you to remove the use of a 'is
null' subprogram.

[Bug ada/65524] gnatbind generates decrementing the unexisting elab-counter into finalize_library

[charlet at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65524

Arnaud Charlet charlet at gcc dot gnu.org changed:

   What|Removed |Added

 Status|UNCONFIRMED |WAITING
   Last reconfirmed||2015-03-23
 CC||charlet at gcc dot gnu.org
 Ever confirmed|0   |1

--- Comment #1 from Arnaud Charlet charlet at gcc dot gnu.org ---
Sounds interesting/puzzling. But we really need a reproducer/test case to work
from.

[Bug ada/65524] gnatbind generates decrementing the unexisting elab-counter into finalize_library

[demoonlit at panathenaia dot halfmoon.jp]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65524

--- Comment #2 from yuta tomino demoonlit at panathenaia dot halfmoon.jp ---
Created attachment 35115
  -- https://gcc.gnu.org/bugzilla/attachment.cgi?id=35115action=edit
example

I found the way of reproducing.

A tiny change of a-tags.ads is necessary.
Insert is null into Ada.Tags.Register_Tag to suppress the elaboration.
(Is there a pragma or restriction for this purpose?)

Note, Unregister_Tag is unrelated.

And, make a package as Pure or Preelaborate. Add a tagged type.
So the package would have _finalize_spec without _elabs.

(The direct cause of this case is the asymmetry that _elabs is not generated if
Register_Tag is null, against that,
_fialize_spec is always generated even if Unregister_Tag is null.
Register/Unregister_XXX are sometimes suppressed in parts of customized
runtimes.
My customized runtime satisfies the conditions about this time.
However, the way is only example for reproducing.
I think another approach is possibility because Build_Finalizer in exp_ch7.adb
is very complex...)

And then, prepare a main subprogram using the package. Compile and gnatbind.
See b~main.adb.

The log of compiling the attached example:

 % gnatmake -a -gnatp -g main
 gnatbind -x main.ali
 gnatlink main.ali -g
 b~main.adb:31:10: E81 is undefined (more references follow)
 b~main.adb:34:07: E05 is undefined (more references follow)
 gnatmake: *** link failed.

By the way, sorry, I realized that my first patch is not proper fix.
For multiple-elaboration, an elaboration-counter should be generated and
incremented in adainit when a _finalize_spec/body is existing, even if _elabs
is not existing.

Thanks.